TY - JOUR A1 - Notz, Quirin A1 - Heyland, Daren K. A1 - Lee, Zheng-Yii A1 - Menger, Johannes A1 - Herrmann, Johannes A1 - Chillon, Thilo S. A1 - Fremes, Stephen A1 - Mohammadi, Siamak A1 - Elke, Gunnar A1 - Mazer, C. David A1 - Hill, Aileen A1 - Velten, Markus A1 - Ott, Sascha A1 - Kleine-Brueggeney, Maren A1 - Meybohm, Patrick A1 - Schomburg, Lutz A1 - Stoppe, Christian T1 - Identifying a target group for selenium supplementation in high-risk cardiac surgery: a secondary analysis of the SUSTAIN CSX trial JF - Intensive Care Medicine Experimental N2 - Background Recent data from the randomized SUSTAIN CSX trial could not confirm clinical benefits from perioperative selenium treatment in high-risk cardiac surgery patients. Underlying reasons may involve inadequate biosynthesis of glutathione peroxidase (GPx3), which is a key mediator of selenium's antioxidant effects. This secondary analysis aimed to identify patients with an increase in GPx3 activity following selenium treatment. We hypothesize that these responders might benefit from perioperative selenium treatment. Methods Patients were selected based on the availability of selenium biomarker information. Four subgroups were defined according to the patient's baseline status, including those with normal kidney function, reduced kidney function, selenium deficiency, and submaximal GPx3 activity. Results Two hundred and forty-four patients were included in this analysis. Overall, higher serum concentrations of selenium, selenoprotein P (SELENOP) and GPx3 were correlated with less organ injury. GPx3 activity at baseline was predictive of 6-month survival (AUC 0.73; p = 0.03). While selenium treatment elevated serum selenium and SELENOP concentrations but not GPx3 activity in the full patient cohort, subgroup analyses revealed that GPx3 activity increased in patients with reduced kidney function, selenium deficiency and low to moderate GPx3 activity. Clinical outcomes did not vary between selenium treatment and placebo in any of these subgroups, though the study was not powered to conclusively detect differences in outcomes. Conclusions The identification of GPx3 responders encourages further refined investigations into the treatment effects of selenium in high-risk cardiac surgery patients. KW - selenium KW - glutathione peroxidase KW - cardiac surgery KW - critical care KW - oxidative stress KW - SUSTAIN CSX Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357196 VL - 11 ER - TY - JOUR A1 - Petruski-Ivleva, Natalia A1 - Kucharska-Newton, Anna A1 - Palta, Priya A1 - Couper, David A1 - Meyer, Katie A1 - Graff, Misa A1 - Haring, Bernhard A1 - Sharrett, Richey A1 - Heiss, Gerardo T1 - Milk intake at midlife and cognitive decline over 20 years. The Atherosclerosis risk in communities (ARIC) study JF - Nutrients N2 - Background: Faster rates of cognitive decline are likely to result in earlier onset of cognitive impairment and dementia. d-galactose, a derivative of lactose, is used in animal studies to induce neurodegeneration. Milk is the primary source of lactose in the human diet, and its effects on cognitive decline have not been fully evaluated. Objective: Assess the association of milk intake with change in cognitive function over 20 years. Methods: A total of 13,751 participants of the Atherosclerosis Risk in Communities (ARIC) cohort completed a food frequency questionnaire and three neurocognitive evaluations from 1990 through 2013. Two single nucleotide polymorphisms (SNPs) were used to determine lactase persistence (LCT-13910 C/T for Whites and LCT-14010 G/C for Blacks). Mixed-effects models were used to study the association of milk intake with cognitive change. Multiple imputations by chained equations were used to account for attrition. Results: Milk intake greater than 1 glass/day was associated with greater decline in the global z-score over a 20-year period. The difference in decline was 0.10 (95% CI: 0.16, 0.03) z-scores, or an additional 10% decline, relative to the group reporting “almost never” consuming milk. Conclusions: Replication of these results is warranted in diverse populations with greater milk intake and higher variability of lactase persistence genotype. KW - lactose KW - lactase persistence KW - oxidative stress KW - cognitive decline KW - dementia KW - aging Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-173909 VL - 9 IS - 10 ER - TY - JOUR A1 - Gorlova, Anna A1 - Svirin, Evgeniy A1 - Pavlov, Dmitrii A1 - Cespuglio, Raymond A1 - Proshin, Andrey A1 - Schroeter, Careen A. A1 - Lesch, Klaus-Peter A1 - Strekalova, Tatyana T1 - Understanding the role of oxidative stress, neuroinflammation and abnormal myelination in excessive aggression associated with depression: recent input from mechanistic studies JF - International Journal of Molecular Sciences N2 - Aggression and deficient cognitive control problems are widespread in psychiatric disorders, including major depressive disorder (MDD). These abnormalities are known to contribute significantly to the accompanying functional impairment and the global burden of disease. Progress in the development of targeted treatments of excessive aggression and accompanying symptoms has been limited, and there exists a major unmet need to develop more efficacious treatments for depressed patients. Due to the complex nature and the clinical heterogeneity of MDD and the lack of precise knowledge regarding its pathophysiology, effective management is challenging. Nonetheless, the aetiology and pathophysiology of MDD has been the subject of extensive research and there is a vast body of the latest literature that points to new mechanisms for this disorder. Here, we overview the key mechanisms, which include neuroinflammation, oxidative stress, insulin receptor signalling and abnormal myelination. We discuss the hypotheses that have been proposed to unify these processes, as many of these pathways are integrated for the neurobiology of MDD. We also describe the current translational approaches in modelling depression, including the recent advances in stress models of MDD, and emerging novel therapies, including novel approaches to management of excessive aggression, such as anti-diabetic drugs, antioxidant treatment and herbal compositions. KW - major depressive disorder (MDD) KW - aggression KW - neuroinflammation KW - oxidative stress KW - insulin receptor KW - myelination Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-304917 SN - 1422-0067 VL - 24 IS - 2 ER - TY - JOUR A1 - Djelić, Ninoslav A1 - Borozan, Sunčica A1 - Dimitrijević-Srećković, Vesna A1 - Pajović, Nevena A1 - Mirilović, Milorad A1 - Stopper, Helga A1 - Stanimirović, Zoran T1 - Oxidative stress and DNA damage in peripheral blood mononuclear cells from normal, obese, prediabetic and diabetic persons exposed to thyroid hormone in vitro JF - International Journal of Molecular Sciences N2 - Diabetes, a chronic group of medical disorders characterized byhyperglycemia, has become a global pandemic. Some hormones may influence the course and outcome of diabetes, especially if they potentiate the formation of reactive oxygen species (ROS). There is a close relationship between thyroid disorders and diabetes. The main objective of this investigation was to find out whether peripheral blood mononuclear cells (PBMCs) are more prone to DNA damage by triiodothyronine (T\(_3\)) (0.1, 1 and 10 μM) at various stages of progression through diabetes (obese, prediabetics, and type 2 diabetes mellitus—T2DM persons). In addition, some biochemical parameters of oxidative stress (catalase-CAT, thiobarbituric acid reactive substances—TBARS) and lactate dehydrogenase (LDH) were evaluated. PBMCs from prediabetic and diabetic patients exhibited increased sensitivity for T\(_3\) regarding elevated level of DNA damage, inhibition of catalase, and increase of TBARS and LDH. PBMCs from obese patients reacted in the same manner, except for DNA damage. The results of this study should contribute to a better understanding of the role of thyroid hormones in the progression of T2DM. KW - diabetes KW - oxidative stress KW - DNA damage KW - lymphocytes KW - thyroid hormone Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-285988 SN - 1422-0067 VL - 23 IS - 16 ER - TY - JOUR A1 - Magliocca, Giorgia A1 - Mone, Pasquale A1 - Di Iorio, Biagio Raffaele A1 - Heidland, August A1 - Marzocco, Stefania T1 - Short-chain fatty acids in Chronic Kidney Disease: focus on inflammation and oxidative stress regulation JF - International Journal of Molecular Sciences N2 - Chronic Kidney Disease (CKD) is a debilitating disease associated with several secondary complications that increase comorbidity and mortality. In patients with CKD, there is a significant qualitative and quantitative alteration in the gut microbiota, which, consequently, also leads to reduced production of beneficial bacterial metabolites, such as short-chain fatty acids. Evidence supports the beneficial effects of short-chain fatty acids in modulating inflammation and oxidative stress, which are implicated in CKD pathogenesis and progression. Therefore, this review will provide an overview of the current knowledge, based on pre-clinical and clinical evidence, on the effect of SCFAs on CKD-associated inflammation and oxidative stress. KW - chronic kidney disease KW - short-chain fatty acids KW - oxidative stress KW - inflammation KW - uremic toxins Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284587 SN - 1422-0067 VL - 23 IS - 10 ER - TY - JOUR A1 - Dresen, Ellen A1 - Pimiento, Jose M. A1 - Patel, Jayshil J. A1 - Heyland, Daren K. A1 - Rice, Todd W. A1 - Stoppe, Christian T1 - Overview of oxidative stress and the role of micronutrients in critical illness JF - Journal of Parenteral and Enteral Nutrition N2 - Inflammation and oxidative stress represent physiological response mechanisms to different types of stimuli and injury during critical illness. Its proper regulation is fundamental to cellular and organismal survival and are paramount to outcomes and recovery from critical illness. A proper maintenance of the delicate balance between inflammation, oxidative stress, and immune response is crucial for resolution from critical illness with important implications for patient outcome. The extent of inflammation and oxidative stress under normal conditions is limited by the antioxidant defense system of the human body, whereas the antioxidant capacity is commonly significantly compromised, and serum levels of micronutrients and vitamins significantly depleted in patients who are critically ill. Hence, the provision of antioxidants and anti-inflammatory nutrients may help to reduce the extent of oxidative stress and therefore improve clinical outcomes in patients who are critically ill. As existing evidence of the beneficial effects of antioxidant supplementation in patients who are critically ill is still unclear, actual findings about the most promising anti-inflammatory and antioxidative candidates selenium, vitamin C, zinc, and vitamin D will be discussed in this narrative review. The existing evidence provided so far demonstrates that several factors need to be considered to determine the efficacy of an antioxidant supplementation strategy in patients who are critically ill and indicates the need for adequately designed multicenter prospective randomized control trials to evaluate the clinical significance of different types and doses of micronutrients and vitamins in selected groups of patients with different types of critical illness. KW - critical illness KW - vitamins KW - vitamin C KW - inflammation KW - medical nutrition therapy KW - oxidative stress KW - selenium KW - trace elements KW - micronutrients KW - vitamin D KW - zinc Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-318186 VL - 47 SP - S38 EP - S49 ER - TY - JOUR A1 - Rapa, Shara Francesca A1 - Di Iorio, Biagio Raffaele A1 - Campiglia, Pietro A1 - Heidland, August A1 - Marzocco, Stefania T1 - Inflammation and oxidative stress in chronic kidney disease — Potential therapeutic role of minerals, vitamins and plant-derived metabolites JF - International Journal of Molecular Sciences N2 - Chronic kidney disease (CKD) is a debilitating pathology with various causal factors, culminating in end stage renal disease (ESRD) requiring dialysis or kidney transplantation. The progression of CKD is closely associated with systemic inflammation and oxidative stress, which are responsible for the manifestation of numerous complications such as malnutrition, atherosclerosis, coronary artery calcification, heart failure, anemia and mineral and bone disorders, as well as enhanced cardiovascular mortality. In addition to conventional therapy with anti-inflammatory and antioxidative agents, growing evidence has indicated that certain minerals, vitamins and plant-derived metabolites exhibit beneficial effects in these disturbances. In the current work, we review the anti-inflammatory and antioxidant properties of various agents which could be of potential benefit in CKD/ESRD. However, the related studies were limited due to small sample sizes and short-term follow-up in many trials. Therefore, studies of several anti-inflammatory and antioxidant agents with long-term follow-ups are necessary. KW - chronic kidney disease (CKD) KW - inflammation KW - oxidative stress KW - uremic toxins KW - minerals KW - vitamins KW - plant-derived metabolites Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284998 SN - 1422-0067 VL - 21 IS - 1 ER - TY - JOUR A1 - Fathy, Moustafa A1 - Darwish, Mostafa A. A1 - Abdelhamid, Al-Shaimaa M. A1 - Alrashedy, Gehad M. A1 - Othman, Othman Ali A1 - Naseem, Muhammad A1 - Dandekar, Thomas A1 - Othman, Eman M. T1 - Kinetin ameliorates cisplatin-induced hepatotoxicity and lymphotoxicity via attenuating oxidative damage, cell apoptosis and inflammation in rats JF - Biomedicines N2 - Though several previous studies reported the in vitro and in vivo antioxidant effect of kinetin (Kn), details on its action in cisplatin-induced toxicity are still scarce. In this study we evaluated, for the first time, the effects of kinetin in cisplatin (cp)- induced liver and lymphocyte toxicity in rats. Wistar male albino rats were divided into nine groups: (i) the control (C), (ii) groups 2,3 and 4, which received 0.25, 0.5 and 1 mg/kg kinetin for 10 days; (iii) the cisplatin (cp) group, which received a single intraperitoneal injection of CP (7.0 mg/kg); and (iv) groups 6, 7, 8 and 9, which received, for 10 days, 0.25, 0.5 and 1 mg/kg kinetin or 200 mg/kg vitamin C, respectively, and Cp on the fourth day. CP-injected rats showed a significant impairment in biochemical, oxidative stress and inflammatory parameters in hepatic tissue and lymphocytes. PCR showed a profound increase in caspase-3, and a significant decline in AKT gene expression. Intriguingly, Kn treatment restored the biochemical, redox status and inflammatory parameters. Hepatic AKT and caspase-3 expression as well as CD95 levels in lymphocytes were also restored. In conclusion, Kn mitigated oxidative imbalance, inflammation and apoptosis in CP-induced liver and lymphocyte toxicity; therefore, it can be considered as a promising therapy. KW - cisplatin KW - hepatotoxicity KW - lymphotoxicity KW - oxidative stress KW - AKT KW - CD95 KW - caspase-3 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-281686 SN - 2227-9059 VL - 10 IS - 7 ER - TY - JOUR A1 - Behera, Ananyaashree A1 - Jain, Preeti A1 - Ganguli, Geetanjali A1 - Biswas, Mainak A1 - Padhi, Avinash A1 - Pattanaik, Kali Prasad A1 - Nayak, Barsa A1 - Ergün, Süleyman A1 - Hagens, Kristine A1 - Redinger, Natalja A1 - Saqib, Mohd A1 - Mishra, Bibhuti B. A1 - Schaible, Ulrich E. A1 - Karnati, Srikanth A1 - Sonawane, Avinash T1 - Mycobacterium tuberculosis acetyltransferase suppresses oxidative stress by inducing peroxisome formation in macrophages JF - International Journal of Molecular Sciences N2 - Mycobacterium tuberculosis (Mtb) inhibits host oxidative stress responses facilitating its survival in macrophages; however, the underlying molecular mechanisms are poorly understood. Here, we identified a Mtb acetyltransferase (Rv3034c) as a novel counter actor of macrophage oxidative stress responses by inducing peroxisome formation. An inducible Rv3034c deletion mutant of Mtb failed to induce peroxisome biogenesis, expression of the peroxisomal β-oxidation pathway intermediates (ACOX1, ACAA1, MFP2) in macrophages, resulting in reduced intracellular survival compared to the parental strain. This reduced virulence phenotype was rescued by repletion of Rv3034c. Peroxisome induction depended on the interaction between Rv3034c and the macrophage mannose receptor (MR). Interaction between Rv3034c and MR induced expression of the peroxisomal biogenesis proteins PEX5p, PEX13p, PEX14p, PEX11β, PEX19p, the peroxisomal membrane lipid transporter ABCD3, and catalase. Expression of PEX14p and ABCD3 was also enhanced in lungs from Mtb aerosol-infected mice. This is the first report that peroxisome-mediated control of ROS balance is essential for innate immune responses to Mtb but can be counteracted by the mycobacterial acetyltransferase Rv3034c. Thus, peroxisomes represent interesting targets for host-directed therapeutics to tuberculosis. KW - peroxisome KW - Rv3034c KW - acetyltransferase KW - macrophages KW - oxidative stress KW - Mycobacterium tuberculosis Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284080 SN - 1422-0067 VL - 23 IS - 5 ER - TY - JOUR A1 - Müller, Thomas A1 - Mueller, Bernhard Klaus A1 - Riederer, Peter T1 - Perspective: Treatment for disease modification in chronic neurodegeneration JF - Cells N2 - Symptomatic treatments are available for Parkinson's disease and Alzheimer's disease. An unmet need is cure or disease modification. This review discusses possible reasons for negative clinical study outcomes on disease modification following promising positive findings from experimental research. It scrutinizes current research paradigms for disease modification with antibodies against pathological protein enrichment, such as α-synuclein, amyloid or tau, based on post mortem findings. Instead a more uniform regenerative and reparative therapeutic approach for chronic neurodegenerative disease entities is proposed with stimulation of an endogenously existing repair system, which acts independent of specific disease mechanisms. The repulsive guidance molecule A pathway is involved in the regulation of peripheral and central neuronal restoration. Therapeutic antagonism of repulsive guidance molecule A reverses neurodegeneration according to experimental outcomes in numerous disease models in rodents and monkeys. Antibodies against repulsive guidance molecule A exist. First clinical studies in neurological conditions with an acute onset are under way. Future clinical trials with these antibodies should initially focus on well characterized uniform cohorts of patients. The efficiency of repulsive guidance molecule A antagonism and associated stimulation of neurogenesis should be demonstrated with objective assessment tools to counteract dilution of therapeutic effects by subjectivity and heterogeneity of chronic disease entities. Such a research concept will hopefully enhance clinical test strategies and improve the future therapeutic armamentarium for chronic neurodegeneration. KW - neurodegeneration KW - repulsive guidance molecule A KW - neuroprotection KW - repair KW - oxidative stress KW - apoptosis KW - neurogenesis Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-236644 SN - 2073-4409 VL - 10 IS - 4 ER - TY - JOUR A1 - Budde, Heidi A1 - Hassoun, Roua A1 - Tangos, Melina A1 - Zhazykbayeva, Saltanat A1 - Herwig, Melissa A1 - Varatnitskaya, Marharyta A1 - Sieme, Marcel A1 - Delalat, Simin A1 - Sultana, Innas A1 - Kolijn, Detmar A1 - Gömöri, Kamilla A1 - Jarkas, Muhammad A1 - Lódi, Mária A1 - Jaquet, Kornelia A1 - Kovács, Árpád A1 - Mannherz, Hans Georg A1 - Sequeira, Vasco A1 - Mügge, Andreas A1 - Leichert, Lars I. A1 - Sossalla, Samuel A1 - Hamdani, Nazha T1 - The interplay between S-glutathionylation and phosphorylation of cardiac troponin I and myosin binding protein C in end-stage human failing hearts JF - Antioxidants N2 - Oxidative stress is defined as an imbalance between the antioxidant defense system and the production of reactive oxygen species (ROS). At low levels, ROS are involved in the regulation of redox signaling for cell protection. However, upon chronical increase in oxidative stress, cell damage occurs, due to protein, DNA and lipid oxidation. Here, we investigated the oxidative modifications of myofilament proteins, and their role in modulating cardiomyocyte function in end-stage human failing hearts. We found altered maximum Ca\(^{2+}\)-activated tension and Ca\(^{2+}\) sensitivity of force production of skinned single cardiomyocytes in end-stage human failing hearts compared to non-failing hearts, which was corrected upon treatment with reduced glutathione enzyme. This was accompanied by the increased oxidation of troponin I and myosin binding protein C, and decreased levels of protein kinases A (PKA)- and C (PKC)-mediated phosphorylation of both proteins. The Ca\(^{2+}\) sensitivity and maximal tension correlated strongly with the myofilament oxidation levels, hypo-phosphorylation, and oxidative stress parameters that were measured in all the samples. Furthermore, we detected elevated titin-based myocardial stiffness in HF myocytes, which was reversed by PKA and reduced glutathione enzyme treatment. Finally, many oxidative stress and inflammation parameters were significantly elevated in failing hearts compared to non-failing hearts, and corrected upon treatment with the anti-oxidant GSH enzyme. Here, we provide evidence that the altered mechanical properties of failing human cardiomyocytes are partially due to phosphorylation, S-glutathionylation, and the interplay between the two post-translational modifications, which contribute to the development of heart failure. KW - myofilament proteins KW - oxidative stress KW - inflammation KW - phosphorylation KW - S-glutathionylation Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-242701 SN - 2076-3921 VL - 10 IS - 7 ER - TY - JOUR A1 - Ferianec, Vladimír A1 - Fülöp, Matej A1 - Ježovičová, Miriam A1 - Radošinská, Jana A1 - Husseinová, Marta A1 - Feriancová, Michaela A1 - Radošinská, Dominika A1 - Barančík, Miroslav A1 - Muchová, Jana A1 - Hȍgger, Petra A1 - Ďuračková, Zdeňka T1 - The oak−wood extract Robuvit\(^®\) improves recovery and oxidative stress after hysterectomy: a randomized, double-blind, placebo-controlled pilot study JF - Nutrients N2 - Hysterectomy has a variety of medical indications and improves pre-operative symptoms but might compromise the quality of life during recovery due to symptoms such as fatigue, headache, nausea, depression, or pain. The aim of the present study was to determine the effect of a standardized extract from French oak wood (Quercus robur) containing at least 40% polyphenols of the ellagitannins class, Robuvit\(^®\), on convalescence and oxidative stress of women after hysterectomy. Recovery status was monitored with the SF-36 questionnaire. The supplementation with Robuvit\(^®\) (300 mg/day) during 4 weeks significantly improved general and mental health, while under placebo some items significantly deteriorated. Oxidative stress and enhancement of MMP–9 activity was significantly reduced by Robuvit\(^®\) versus placebo. After 8 weeks of intervention, the patients’ condition improved independently of the intervention. Our results suggest that the use of Robuvit\(^®\) as a natural supplement relieves post-operative symptoms of patients after hysterectomy and reduces oxidative stress. The study was registered with ID ISRCTN 11457040 (13/09/2019). KW - hysterectomy KW - Robuvit\(^®\) KW - oak wood extract KW - post-operative recovery KW - oxidative stress KW - matrix metalloproteinases KW - complementary medicine Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-203265 SN - 2072-6643 VL - 12 IS - 4 ER - TY - JOUR A1 - de Munter, Johannes A1 - Pavlov, Dmitrii A1 - Gorlova, Anna A1 - Sicker, Michael A1 - Proshin, Andrey A1 - Kalueff, Allan V. A1 - Svistunov, Andrey A1 - Kiselev, Daniel A1 - Nedorubov, Andrey A1 - Morozov, Sergey A1 - Umriukhin, Aleksei A1 - Lesch, Klaus-Peter A1 - Strekalova, Tatyana A1 - Schroeter, Careen A. T1 - Increased Oxidative Stress in the Prefrontal Cortex as a Shared Feature of Depressive- and PTSD-Like Syndromes: Effects of a Standardized Herbal Antioxidant JF - Frontiers in Nutrition N2 - Major depression (MD) and posttraumatic stress disorder (PTSD) share common brain mechanisms and treatment strategies. Nowadays, the dramatically developing COVID-19 situation unavoidably results in stress, psychological trauma, and high incidence of MD and PTSD. Hence, the importance of the development of new treatments for these disorders cannot be overstated. Herbal medicine appears to be an effective and safe treatment with fewer side effects than classic pharmaca and that is affordable in low-income countries. Currently, oxidative stress and neuroinflammation attract increasing attention as important mechanisms of MD and PTSD. We investigated the effects of a standardized herbal cocktail (SHC), an extract of clove, bell pepper, basil, pomegranate, nettle, and other plants, that was designed as an antioxidant treatment in mouse models of MD and PTSD. In the MD model of “emotional” ultrasound stress (US), mice were subjected to ultrasound frequencies of 16–20 kHz, mimicking rodent sounds of anxiety/despair and “neutral” frequencies of 25–45 kHz, for three weeks and concomitantly treated with SHC. US-exposed mice showed elevated concentrations of oxidative stress markers malondialdehyde and protein carbonyl, increased gene and protein expression of pro-inflammatory cytokines interleukin (IL)-1β and IL-6 and other molecular changes in the prefrontal cortex as well as weight loss, helplessness, anxiety-like behavior, and neophobia that were ameliorated by the SHC treatment. In the PTSD model of the modified forced swim test (modFST), in which a 2-day swim is followed by an additional swim on day 5, mice were pretreated with SHC for 16 days. Increases in the floating behavior and oxidative stress markers malondialdehyde and protein carbonyl in the prefrontal cortex of modFST-mice were prevented by the administration of SHC. Chromatography mass spectrometry revealed bioactive constituents of SHC, including D-ribofuranose, beta-D-lactose, malic, glyceric, and citric acids that can modulate oxidative stress, immunity, and gut and microbiome functions and, thus, are likely to be active antistress elements underlying the beneficial effects of SHC. Significant correlations of malondialdehyde concentration in the prefrontal cortex with altered measures of behavioral despair and anxiety-like behavior suggest that the accumulation of oxidative stress markers are a common biological feature of MD and PTSD that can be equally effectively targeted therapeutically with antioxidant therapy, such as the SHC investigated here. KW - antioxidant nutrients KW - oxidative stress KW - depression KW - post-traumatic stress disorder KW - pro-inflammatory cytokines KW - prefrontal cortex KW - forced swimming KW - mice Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-236326 SN - 2296-861X VL - 8 ER - TY - JOUR A1 - Karnati, Srikanth A1 - Seimetz, Michael A1 - Kleefeldt, Florian A1 - Sonawane, Avinash A1 - Madhusudhan, Thati A1 - Bachhuka, Akash A1 - Kosanovic, Djuro A1 - Weissmann, Norbert A1 - Krüger, Karsten A1 - Ergün, Süleyman T1 - Chronic Obstructive Pulmonary Disease and the Cardiovascular System: Vascular Repair and Regeneration as a Therapeutic Target JF - Frontiers in Cardiovascular Medicine N2 - Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide and encompasses chronic bronchitis and emphysema. It has been shown that vascular wall remodeling and pulmonary hypertension (PH) can occur not only in patients with COPD but also in smokers with normal lung function, suggesting a causal role for vascular alterations in the development of emphysema. Mechanistically, abnormalities in the vasculature, such as inflammation, endothelial dysfunction, imbalances in cellular apoptosis/proliferation, and increased oxidative/nitrosative stress promote development of PH, cor pulmonale, and most probably pulmonary emphysema. Hypoxemia in the pulmonary chamber modulates the activation of key transcription factors and signaling cascades, which propagates inflammation and infiltration of neutrophils, resulting in vascular remodeling. Endothelial progenitor cells have angiogenesis capabilities, resulting in transdifferentiation of the smooth muscle cells via aberrant activation of several cytokines, growth factors, and chemokines. The vascular endothelium influences the balance between vaso-constriction and -dilation in the heart. Targeting key players affecting the vasculature might help in the development of new treatment strategies for both PH and COPD. The present review aims to summarize current knowledge about vascular alterations and production of reactive oxygen species in COPD. The present review emphasizes on the importance of the vasculature for the usually parenchyma-focused view of the pathobiology of COPD. KW - COPD KW - emphysema KW - pulmonary hypertension KW - hypoxia KW - oxidative stress Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-235631 SN - 2297-055X VL - 8 ER - TY - JOUR A1 - Friedmann Angeli, José Pedro A1 - Meierjohann, Svenja T1 - NRF2‐dependent stress defense in tumor antioxidant control and immune evasion JF - Pigment Cell & Melanoma Research N2 - The transcription factor NRF2 is known as the master regulator of the oxidative stress response. Tumor entities presenting oncogenic activation of NRF2, such as lung adenocarcinoma, are associated with drug resistance, and accumulating evidence demonstrates its involvement in immune evasion. In other cancer types, the KEAP1/NRF2 pathway is not commonly mutated, but NRF2 is activated by other means such as radiation, oncogenic activity, cytokines, or other pro‐oxidant triggers characteristic of the tumor niche. The obvious effect of stress‐activated NRF2 is the protection from oxidative or electrophilic damage and the adaptation of the tumor metabolism to changing conditions. However, data from melanoma also reveal a role of NRF2 in modulating differentiation and suppressing anti‐tumor immunity. This review summarizes the function of NRF2 in this tumor entity and discusses the implications for current tumor therapies. KW - immune evasion KW - KEAP1 KW - Nrf2 KW - oxidative stress Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-224536 VL - 34 IS - 2 SP - 268 EP - 279 ER - TY - JOUR A1 - Notz, Quirin A1 - Herrmann, Johannes A1 - Schlesinger, Tobias A1 - Helmer, Philipp A1 - Sudowe, Stephan A1 - Sun, Qian A1 - Hackler, Julian A1 - Roeder, Daniel A1 - Lotz, Christopher A1 - Meybohm, Patrick A1 - Kranke, Peter A1 - Schomburg, Lutz A1 - Stoppe, Christian T1 - Clinical Significance of Micronutrient Supplementation in Critically Ill COVID-19 Patients with Severe ARDS JF - Nutrients N2 - The interplay between inflammation and oxidative stress is a vicious circle, potentially resulting in organ damage. Essential micronutrients such as selenium (Se) and zinc (Zn) support anti-oxidative defense systems and are commonly depleted in severe disease. This single-center retrospective study investigated micronutrient levels under Se and Zn supplementation in critically ill patients with COVID-19 induced acute respiratory distress syndrome (ARDS) and explored potential relationships with immunological and clinical parameters. According to intensive care unit (ICU) standard operating procedures, patients received 1.0 mg of intravenous Se daily on top of artificial nutrition, which contained various amounts of Se and Zn. Micronutrients, inflammatory cytokines, lymphocyte subsets and clinical data were extracted from the patient data management system on admission and after 10 to 14 days of treatment. Forty-six patients were screened for eligibility and 22 patients were included in the study. Twenty-one patients (95%) suffered from severe ARDS and 14 patients (64%) survived to ICU discharge. On admission, the majority of patients had low Se status biomarkers and Zn levels, along with elevated inflammatory parameters. Se supplementation significantly elevated Se (p = 0.027) and selenoprotein P levels (SELENOP; p = 0.016) to normal range. Accordingly, glutathione peroxidase 3 (GPx3) activity increased over time (p = 0.021). Se biomarkers, most notably SELENOP, were inversely correlated with CRP (r\(_s\) = −0.495), PCT (r\(_s\) = −0.413), IL-6 (r\(_s\) = −0.429), IL-1β (r\(_s\) = −0.440) and IL-10 (r\(_s\) = −0.461). Positive associations were found for CD8\(^+\) T cells (r(_s\) = 0.636), NK cells (r\(_s\) = 0.772), total IgG (r\(_s\) = 0.493) and PaO\(_2\)/FiO\(_2\) ratios (r\(_s\) = 0.504). In addition, survivors tended to have higher Se levels after 10 to 14 days compared to non-survivors (p = 0.075). Sufficient Se and Zn levels may potentially be of clinical significance for an adequate immune response in critically ill patients with severe COVID-19 ARDS. KW - acute respiratory distress syndrome KW - selen KW - zinc KW - critical care KW - oxidative stress KW - nutrient supplementation Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-241112 SN - 2072-6643 VL - 13 IS - 6 ER - TY - JOUR A1 - Macdougall, Iain C. A1 - Bircher, Andreas J. A1 - Eckhardt, Kai-Uwe A1 - Obrador, Gregorio T. A1 - Pollock, Carol A. A1 - Stenvinkel, Peter A1 - Swinkels, Dorine W. A1 - Wanner, Christoph A1 - Weiss, Günter A1 - Chertow, Glenn M. T1 - Iron management in chronic kidney disease: conclusions from a "Kidney Disease: Improving Global Outcomes" (KDIGO) Controversies Conference JF - Kidney International N2 - Before the introduction of erythropoiesis-stimulating agents (ESAs) in 1989, repeated transfusions given to patients with end-stage renal disease caused iron overload, and the need for supplemental iron was rare. However, with the widespread introduction of ESAs, it was recognized that supplemental iron was necessary to optimize hemoglobin response and allow reduction of the ESA dose for economic reasons and recent concerns about ESA safety. Iron supplementation was also found to be more efficacious via intravenous compared to oral administration, and the use of intravenous iron has escalated in recent years. The safety of various iron compounds has been of theoretical concern due to their potential to induce iron overload, oxidative stress, hypersensitivity reactions, and a permissive environment for infectious processes. Therefore, an expert group was convened to assess the benefits and risks of parenteral iron, and to provide strategies for its optimal use while mitigating the risk for acute reactions and other adverse effects. KW - chronic kidney disease KW - hypersensitivity KW - infections KW - iron KW - overload KW - oxidative stress Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-191467 VL - 89 IS - 1 ER - TY - JOUR A1 - Tinajero-Trejo, Mariana A1 - Rana, Namrata A1 - Nagel, Christoph A1 - Jesse, Helen E. A1 - Smith, Thomas W. A1 - Wareham, Lauren K. A1 - Hippler, Michael A1 - Schatzschneider, Ulrich A1 - Poole, Robert K. T1 - Antimicrobial Activity of the Manganese Photoactivated Carbon Monoxide-Releasing Molecule [Mn(CO)\(_3\)(tpa-kappa\(^3\)N)]\(^+\) Against a Pathogenic Escherichia coli that Causes Urinary Infections JF - Antioxidants & Redox Signaling N2 - Aims: We set out to investigate the antibacterial activity of a new Mn-based photoactivated carbon monoxide-releasing molecule (PhotoCORM, [Mn(CO)\(_3\)(tpa-kappa\(^3\)N)]\(^+\)) against an antibiotic-resistant uropathogenic strain (EC958) of Escherichia coli. Results: Activated PhotoCORM inhibits growth and decreases viability of E. coli EC958, but non-illuminated carbon monoxide-releasing molecule (CORM) is without effect. NADH-supported respiration rates are significantly decreased by activated PhotoCORM, mimicking the effect of dissolved CO gas. CO from the PhotoCORM binds to intracellular targets, namely respiratory oxidases in strain EC958 and a bacterial globin heterologously expressed in strain K-12. However, unlike previously characterized CORMs, the PhotoCORM is not significantly accumulated in cells, as deduced from the cellular manganese content. Activated PhotoCORM reacts avidly with hydrogen peroxide producing hydroxyl radicals; the observed peroxide-enhanced toxicity of the PhotoCORM is ameliorated by thiourea. The PhotoCORM also potentiates the effect of the antibiotic, doxycycline. Innovation: The present work investigates for the first time the antimicrobial activity of a light-activated PhotoCORM against an antibiotic-resistant pathogen. A comprehensive study of the effects of the PhotoCORM and its derivative molecules upon illumination is performed and mechanisms of toxicity of the activated PhotoCORM are investigated. Conclusion: The PhotoCORM allows a site-specific and time-controlled release of CO in bacterial cultures and has the potential to provide much needed information on the generality of CORM activities in biology. Understanding the mechanism(s) of activated PhotoCORM toxicity will be key in exploring the potential of this and similar compounds as antimicrobial agents, perhaps in combinatorial therapies with other agents. KW - intracellular hydrogen-peroxide KW - campylobacter-jejuni KW - oxygen-metabolism KW - deficient mutant KW - oxidative stress KW - aqueous-solution KW - metal caponyls KW - RU(CO)(3)CL(GLYCINATE) KW - bacteria KW - enzyme Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-188910 VL - 24 IS - 14 ER - TY - JOUR A1 - Leonhardt, Ines A1 - Spielberg, Steffi A1 - Weber, Michael A1 - Albrecht-Eckardt, Daniela A1 - Bläss, Markus A1 - Claus, Ralf A1 - Barz, Dagmar A1 - Scherlach, Kirstin A1 - Hertweck, Christian A1 - Löffler, Jürgen A1 - Hünniger, Kerstin A1 - Kurzai, Oliver T1 - The fungal quorum-sensing molecule farnesol activates innate immune cells but suppresses cellular adaptive immunity JF - mBio N2 - Farnesol, produced by the polymorphic fungus Candida albicans, is the first quorum-sensing molecule discovered in eukaryotes. Its main function is control of C. albicans filamentation, a process closely linked to pathogenesis. In this study, we analyzed the effects of farnesol on innate immune cells known to be important for fungal clearance and protective immunity. Farnesol enhanced the expression of activation markers on monocytes (CD86 and HLA-DR) and neutrophils (CD66b and CD11b) and promoted oxidative burst and the release of proinflammatory cytokines (tumor necrosis factor alpha [TNF-\(\alpha\)] and macrophage inflammatory protein 1 alpha [MIP-1 \(\alpha\)]). However, this activation did not result in enhanced fungal uptake or killing. Furthermore, the differentiation of monocytes to immature dendritic cells (iDC) was significantly affected by farnesol. Several markers important for maturation and antigen presentation like CD1a, CD83, CD86, and CD80 were significantly reduced in the presence of farnesol. Furthermore, farnesol modulated migrational behavior and cytokine release and impaired the ability of DC to induce T cell proliferation. Of major importance was the absence of interleukin 12 (IL-12) induction in iDC generated in the presence of farnesol. Transcriptome analyses revealed a farnesol-induced shift in effector molecule expression and a down-regulation of the granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor during monocytes to iDC differentiation. Taken together, our data unveil the ability of farnesol to act as a virulence factor of C. albicans by influencing innate immune cells to promote inflammation and mitigating the Th1 response, which is essential for fungal clearance. KW - human dendritic cells KW - Pseudomonas aeruginosa KW - induced apoptosis KW - cytokine production KW - biofilm formation KW - Candida albicans KW - mouse model KW - systemic candidiasis KW - oxidative stress KW - carcinoma cells Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-143756 VL - 6 IS - 2 ER - TY - JOUR A1 - Blein, Sophie A1 - Bardel, Claire A1 - Danjean, Vincent A1 - McGuffog, Lesley A1 - Healay, Sue A1 - Barrowdale, Daniel A1 - Lee, Andrew A1 - Dennis, Joe A1 - Kuchenbaecker, Karoline B. A1 - Soucy, Penny A1 - Terry, Mary Beth A1 - Chung, Wendy K. A1 - Goldgar, David E. A1 - Buys, Saundra S. A1 - Janavicius, Ramunas A1 - Tihomirova, Laima A1 - Tung, Nadine A1 - Dorfling, Cecilia M. A1 - van Rensburg, Elizabeth J. A1 - Neuhausen, Susan L. A1 - Ding, Yuan Chun A1 - Gerdes, Anne-Marie A1 - Ejlertsen, Bent A1 - Nielsen, Finn C. A1 - Hansen, Thomas V. O. A1 - Osorio, Ana A1 - Benitez, Javier A1 - Andreas Conejero, Raquel A1 - Segota, Ena A1 - Weitzel, Jeffrey N. A1 - Thelander, Margo A1 - Peterlongo, Paolo A1 - Radice, Paolo A1 - Pensotti, Valeria A1 - Dolcetti, Riccardo A1 - Bonanni, Bernardo A1 - Peissel, Bernard A1 - Zaffaroni, Daniela A1 - Scuvera, Giulietta A1 - Manoukian, Siranoush A1 - Varesco, Liliana A1 - Capone, Gabriele L. A1 - Papi, Laura A1 - Ottini, Laura A1 - Yannoukakos, Drakoulis A1 - Konstantopoulou, Irene A1 - Garber, Judy A1 - Hamann, Ute A1 - Donaldson, Alan A1 - Brady, Angela A1 - Brewer, Carole A1 - Foo, Claire A1 - Evans, D. Gareth A1 - Frost, Debra A1 - Eccles, Diana A1 - Douglas, Fiona A1 - Cook, Jackie A1 - Adlard, Julian A1 - Barwell, Julian A1 - Walker, Lisa A1 - Izatt, Louise A1 - Side, Lucy E. A1 - Kennedy, M. John A1 - Tischkowitz, Marc A1 - Rogers, Mark T. A1 - Porteous, Mary E. A1 - Morrison, Patrick J. A1 - Platte, Radka A1 - Eeles, Ros A1 - Davidson, Rosemarie A1 - Hodgson, Shirley A1 - Cole, Trevor A1 - Godwin, Andrew K A1 - Isaacs, Claudine A1 - Claes, Kathleen A1 - De Leeneer, Kim A1 - Meindl, Alfons A1 - Gehrig, Andrea A1 - Wappenschmidt, Barbara A1 - Sutter, Christian A1 - Engel, Christoph A1 - Niederacher, Dieter A1 - Steinemann, Doris A1 - Plendl, Hansjoerg A1 - Kast, Karin A1 - Rhiem, Kerstin A1 - Ditsch, Nina A1 - Arnold, Norbert A1 - Varon-Mateeva, Raymonda A1 - Schmutzler, Rita K. A1 - Preisler-Adams, Sabine A1 - Markov, Nadja Bogdanova A1 - Wang-Gohrke, Shan A1 - de Pauw, Antoine A1 - Lefol, Cedrick A1 - Lasset, Christine A1 - Leroux, Dominique A1 - Rouleau, Etienne A1 - Damiola, Francesca A1 - Dreyfus, Helene A1 - Barjhoux, Laure A1 - Golmard, Lisa A1 - Uhrhammer, Nancy A1 - Bonadona, Valerie A1 - Sornin, Valerie A1 - Bignon, Yves-Jean A1 - Carter, Jonathan A1 - Van Le, Linda A1 - Piedmonte, Marion A1 - DiSilvestro, Paul A. A1 - de la Hoya, Miguel A1 - Caldes, Trinidad A1 - Nevanlinna, Heli A1 - Aittomäki, Kristiina A1 - Jager, Agnes A1 - van den Ouweland, Ans M. W. A1 - Kets, Carolien M. A1 - Aalfs, Cora M. A1 - van Leeuwen, Flora E. A1 - Hogervorst, Frans B. L. A1 - Meijers-Heijboer, Hanne E. J. A1 - Oosterwijk, Jan C. A1 - van Roozendaal, Kees E. P. A1 - Rookus, Matti A. A1 - Devilee, Peter A1 - van der Luijt, Rob B. A1 - Olah, Edith A1 - Diez, Orland A1 - Teule, Alex A1 - Lazaro, Conxi A1 - Blanco, Ignacio A1 - Del Valle, Jesus A1 - Jakubowska, Anna A1 - Sukiennicki, Grzegorz A1 - Gronwald, Jacek A1 - Spurdle, Amanda B. A1 - Foulkes, William A1 - Olswold, Curtis A1 - Lindor, Noralene M. A1 - Pankratz, Vernon S. A1 - Szabo, Csilla I. A1 - Lincoln, Anne A1 - Jacobs, Lauren A1 - Corines, Marina A1 - Robson, Mark A1 - Vijai, Joseph A1 - Berger, Andreas A1 - Fink-Retter, Anneliese A1 - Singer, Christian F. A1 - Rappaport, Christine A1 - Geschwantler Kaulich, Daphne A1 - Pfeiler, Georg A1 - Tea, Muy-Kheng A1 - Greene, Mark H. A1 - Mai, Phuong L. A1 - Rennert, Gad A1 - Imyanitov, Evgeny N. A1 - Mulligan, Anna Marie A1 - Glendon, Gord A1 - Andrulis, Irene L. A1 - Tchatchou, Andrine A1 - Toland, Amanda Ewart A1 - Pedersen, Inge Sokilde A1 - Thomassen, Mads A1 - Kruse, Torben A. A1 - Jensen, Uffe Birk A1 - Caligo, Maria A. A1 - Friedman, Eitan A1 - Zidan, Jamal A1 - Laitman, Yael A1 - Lindblom, Annika A1 - Melin, Beatrice A1 - Arver, Brita A1 - Loman, Niklas A1 - Rosenquist, Richard A1 - Olopade, Olufunmilayo I. A1 - Nussbaum, Robert L. A1 - Ramus, Susan J. A1 - Nathanson, Katherine L. A1 - Domchek, Susan M. A1 - Rebbeck, Timothy R. A1 - Arun, Banu K. A1 - Mitchell, Gillian A1 - Karlan, Bethy Y. A1 - Lester, Jenny A1 - Orsulic, Sandra A1 - Stoppa-Lyonnet, Dominique A1 - Thomas, Gilles A1 - Simard, Jacques A1 - Couch, Fergus J. A1 - Offit, Kenenth A1 - Easton, Douglas F. A1 - Chenevix-Trench, Georgia A1 - Antoniou, Antonis C. A1 - Mazoyer, Sylvie A1 - Phelan, Catherine M. A1 - Sinilnikova, Olga M. A1 - Cox, David G. T1 - An original phylogenetic approach identified mitochondrial haplogroup T1a1 as inversely associated with breast cancer risk in BRCA2 mutation carriers JF - Breast Cancer Research N2 - Introduction: Individuals carrying pathogenic mutations in the BRCA1 and BRCA2 genes have a high lifetime risk of breast cancer. BRCA1 and BRCA2 are involved in DNA double-strand break repair, DNA alterations that can be caused by exposure to reactive oxygen species, a main source of which are mitochondria. Mitochondrial genome variations affect electron transport chain efficiency and reactive oxygen species production. Individuals with different mitochondrial haplogroups differ in their metabolism and sensitivity to oxidative stress. Variability in mitochondrial genetic background can alter reactive oxygen species production, leading to cancer risk. In the present study, we tested the hypothesis that mitochondrial haplogroups modify breast cancer risk in BRCA1/2 mutation carriers. Methods: We genotyped 22,214 (11,421 affected, 10,793 unaffected) mutation carriers belonging to the Consortium of Investigators of Modifiers of BRCA1/2 for 129 mitochondrial polymorphisms using the iCOGS array. Haplogroup inference and association detection were performed using a phylogenetic approach. ALTree was applied to explore the reference mitochondrial evolutionary tree and detect subclades enriched in affected or unaffected individuals. Results: We discovered that subclade T1a1 was depleted in affected BRCA2 mutation carriers compared with the rest of clade T (hazard ratio (HR) = 0.55; 95% confidence interval (CI), 0.34 to 0.88; P = 0.01). Compared with the most frequent haplogroup in the general population (that is, H and T clades), the T1a1 haplogroup has a HR of 0.62 (95% CI, 0.40 to 0.95; P = 0.03). We also identified three potential susceptibility loci, including G13708A/rs28359178, which has demonstrated an inverse association with familial breast cancer risk. Conclusions: This study illustrates how original approaches such as the phylogeny-based method we used can empower classical molecular epidemiological studies aimed at identifying association or risk modification effects. KW - single-nucleotide polymorphisms KW - genetic modifiers KW - oxidative stress KW - consortium KW - multiple diseases KW - DNA KW - haplogroups KW - susceptibility KW - Ovarian KW - variants Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-145458 VL - 17 IS - 61 ER - TY - JOUR A1 - Kim, Jae Ho A1 - Franck, Julien A1 - Kang, Taewook A1 - Heinsen, Helmut A1 - Ravid, Rivka A1 - Ferrer, Isidro A1 - Cheon, Mi Hee A1 - Lee, Joo-Yong A1 - Yoo, Jong Shin A1 - Steinbusch, Harry W. A1 - Salzet, Michel A1 - Fournier, Isabelle A1 - Park, Young Mok T1 - Proteome-wide characterization of signalling interactions in the hippocampal CA4/DG subfield of patients with Alzheimer's disease JF - Scientific Reports N2 - Alzheimer's disease (AD) is the most common form of dementia; however, mechanisms and biomarkers remain unclear. Here, we examined hippocampal CA4 and dentate gyrus subfields, which are less studied in the context of AD pathology, in post-mortem AD and control tissue to identify possible biomarkers. We performed mass spectrometry-based proteomic analysis combined with label-free quantification for identification of differentially expressed proteins. We identified 4,328 proteins, of which 113 showed more than 2-fold higher or lower expression in AD hippocampi than in control tissues. Five proteins were identified as putative AD biomarkers (MDH2, PCLO, TRRAP, YWHAZ, and MUC19 isoform 5) and were cross-validated by immunoblotting, selected reaction monitoring, and MALDI imaging. We also used a bioinformatics approach to examine upstream signalling interactions of the 113 regulated proteins. Five upstream signalling (IGF1, BDNF, ZAP70, MYC, and cyclosporin A) factors showed novel interactions in AD hippocampi. Taken together, these results demonstrate a novel platform that may provide new strategies for the early detection of AD and thus its diagnosis. KW - imaging mass spectrometry KW - neuron navigator 3 KW - dentate gyrus KW - growth factor KW - mouse model KW - neurotrophic factor KW - entorhinal cortex KW - factor expression KW - oxidative stress KW - memory deficits Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-151727 VL - 5 IS - 11138 ER - TY - JOUR A1 - Kleikers, Pamela W. M. A1 - Hooijmans, Carlijn A1 - Göb, Eva A1 - Langhauser, Friederike A1 - Rewell, Sarah S. J. A1 - Radermacher, Kim A1 - Ritskes-Hoitinga, Merel A1 - Howells, David W. A1 - Kleinschnitz, Christoph A1 - Schmidt, Harald H. H. W. T1 - A combined pre-clinical meta-analysis and randomized confirmatory trial approach to improve data validity for therapeutic target validation JF - Scientific Reports N2 - Biomedical research suffers from a dramatically poor translational success. For example, in ischemic stroke, a condition with a high medical need, over a thousand experimental drug targets were unsuccessful. Here, we adopt methods from clinical research for a late-stage pre-clinical meta-analysis (MA) and randomized confirmatory trial (pRCT) approach. A profound body of literature suggests NOX\(_{2}\) to be a major therapeutic target in stroke. Systematic review and MA of all available NOX\(_{2}\)\(^{-/y}\) studies revealed a positive publication bias and lack of statistical power to detect a relevant reduction in infarct size. A fully powered multi-center pRCT rejects NOX\(_{2}\) as a target to improve neurofunctional outcomes or achieve a translationally relevant infarct size reduction. Thus stringent statistical thresholds, reporting negative data and a MA-pRCT approach can ensure biomedical data validity and overcome risks of bias. KW - focal cerebral ischemia KW - darbepoetin alpha KW - mice KW - translational stroke research KW - colony-stimulating factor KW - NADPH oxidase inhibitors KW - chronic kidney disease KW - diabetes mellitus KW - oxidative stress KW - search filter Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-151401 VL - 5 IS - 13428 ER - TY - JOUR A1 - Othman, Eman M. A1 - Naseem, Muhammed A1 - Awad, Eman A1 - Dandekar, Thomas A1 - Stopper, Helga T1 - The Plant Hormone Cytokinin Confers Protection against Oxidative Stress in Mammalian Cells JF - PLoS One N2 - Modulating key dynamics of plant growth and development, the effects of the plant hormone cytokinin on animal cells gained much attention recently. Most previous studies on cytokinin effects on mammalian cells have been conducted with elevated cytokinin concentration (in the μM range). However, to examine physiologically relevant dose effects of cytokinins on animal cells, we systematically analyzed the impact of kinetin in cultured cells at low and high concentrations (1nM-10μM) and examined cytotoxic and genotoxic conditions. We furthermore measured the intrinsic antioxidant activity of kinetin in a cell-free system using the Ferric Reducing Antioxidant Power assay and in cells using the dihydroethidium staining method. Monitoring viability, we looked at kinetin effects in mammalian cells such as HL60 cells, HaCaT human keratinocyte cells, NRK rat epithelial kidney cells and human peripheral lymphocytes. Kinetin manifests no antioxidant activity in the cell free system and high doses of kinetin (500 nM and higher) reduce cell viability and mediate DNA damage in vitro. In contrast, low doses (concentrations up to 100 nM) of kinetin confer protection in cells against oxidative stress. Moreover, our results show that pretreatment of the cells with kinetin significantly reduces 4-nitroquinoline 1-oxide mediated reactive oxygen species production. Also, pretreatment with kinetin retains cellular GSH levels when they are also treated with the GSH-depleting agent patulin. Our results explicitly show that low kinetin doses reduce apoptosis and protect cells from oxidative stress mediated cell death. Future studies on the interaction between cytokinins and human cellular pathway targets will be intriguing. KW - DNA damage KW - apoptosis KW - oxidative stress KW - fluorescence recovery after photobleaching KW - lymphocytes KW - antioxidants KW - cell staining KW - cytokinins Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-147983 VL - 11 IS - 12 ER - TY - JOUR A1 - Bankoglu, Ezgi Eyluel A1 - Tschopp, Oliver A1 - Schmitt, Johannes A1 - Burkard, Philipp A1 - Jahn, Daniel A1 - Geier, Andreas A1 - Stopper, Helga T1 - Role of PTEN in Oxidative Stress and DNA Damage in the Liver of Whole-Body Pten Haplodeficient Mice JF - PLoS One N2 - Type 2 diabetes (T2DM) and obesity are frequently associated with non-alcoholic fatty liver disease (NAFLD) and with an elevated cancer incidence. The molecular mechanisms of carcinogenesis in this context are only partially understood. High blood insulin levels are typical in early T2DM and excessive insulin can cause elevated reactive oxygen species (ROS) production and genomic instability. ROS are important for various cellular functions in signaling and host defense. However, elevated ROS formation is thought to be involved in cancer induction. In the molecular events from insulin receptor binding to genomic damage, some signaling steps have been identified, pointing at the PI3K/AKT pathway. For further elucidation Phosphatase and Tensin homolog (Pten), a tumour suppressor phosphatase that plays a role in insulin signaling by negative regulation of PI3K/AKT and its downstream targets, was investigated here. Dihydroethidium (DHE) staining was used to detect ROS formation in immortalized human hepatocytes. Comet assay and micronucleus test were performed to investigate genomic damage in vitro. In liver samples, DHE staining and western blot detection of HSP70 and HO-1 were performed to evaluate oxidative stress response. DNA double strand breaks (DSBs) were detected by immunohistostaining. Inhibition of PTEN with the pharmacologic inhibitor VO-OHpic resulted in increased ROS production and genomic damage in a liver cell line. Knockdown of Pten in a mouse model yielded increased oxidative stress levels, detected by ROS levels and expression of the two stress-proteins HSP70 and HO-1 and elevated genomic damage in the liver, which was significant in mice fed with a high fat diet. We conclude that PTEN is involved in oxidative stress and genomic damage induction in vitro and that this may also explain the in vivo observations. This further supports the hypothesis that the PI3K/AKT pathway is responsible for damaging effects of high levels of insulin. KW - insulin KW - mouse models DNA damage KW - oxidative stress KW - mammalian genomics KW - fatty liver KW - micronuclei KW - insulin signaling Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-146970 VL - 11 IS - 11 ER - TY - JOUR A1 - Klotz, Barbara A1 - Mentrup, Birgit A1 - Regensburger, Martina A1 - Zeck, Sabine A1 - Schneidereit, Jutta A1 - Schupp, Nicole A1 - Linden, Christian A1 - Merz, Cornelia A1 - Ebert, Regina A1 - Jakob, Franz T1 - 1,25-Dihydroxyvitamin D3 Treatment Delays Cellular Aging in Human Mesenchymal Stem Cells while Maintaining Their Multipotent Capacity JF - PLoS ONE N2 - 1,25-dihydroxyvitamin D3 (1,25D3) was reported to induce premature organismal aging in fibroblast growth factor-23 (Fgf23) and klotho deficient mice, which is of main interest as 1,25D3 supplementation of its precursor cholecalciferol is used in basic osteoporosis treatment. We wanted to know if 1,25D3 is able to modulate aging processes on a cellular level in human mesenchymal stem cells (hMSC). Effects of 100 nM 1,25D3 on hMSC were analyzed by cell proliferation and apoptosis assay, beta-galactosidase staining, VDR and surface marker immunocytochemistry, RT-PCR of 1,25D3-responsive, quiescence-and replicative senescence-associated genes. 1,25D3 treatment significantly inhibited hMSC proliferation and apoptosis after 72 h and delayed the development of replicative senescence in long-term cultures according to beta-galactosidase staining and P16 expression. Cell morphology changed from a fibroblast like appearance to broad and rounded shapes. Long term treatment did not induce lineage commitment in terms of osteogenic pathways but maintained their clonogenic capacity, their surface marker characteristics (expression of CD73, CD90, CD105) and their multipotency to develop towards the chondrogenic, adipogenic and osteogenic pathways. In conclusion, 1,25D3 delays replicative senescence in primary hMSC while the pro-aging effects seen in mouse models might mainly be due to elevated systemic phosphate levels, which propagate organismal aging. KW - perspectives KW - bone marrow KW - mutant mice KW - oxidative stress KW - transcription factors KW - vitamin-D-receptor KW - differentiation KW - tissue KW - 2',7'-dichlorofluorescin KW - homeostasis Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-133392 VL - 7 IS - 1 ER - TY - JOUR A1 - Radermacher, Kim A. A1 - Wingler, Kirstin A1 - Kleikers, Pamela A1 - Altenhöfer, Sebastian A1 - Hermans, Johannes J. R. A1 - Kleinschnitz, Christoph A1 - Schmidt, Harald H. H. W. T1 - The 1027th target candidate in stroke: Will NADPH oxidase hold up? JF - Experimental and Translational Stroke Medicine N2 - As recently reviewed, 1026 neuroprotective drug candidates in stroke research have all failed on their road towards validation and clinical translation, reasons being quality issues in preclinical research and publication bias. Quality control guidelines for preclinical stroke studies have now been established. However, sufficient understanding of the underlying mechanisms of neuronal death after stroke that could be possibly translated into new therapies is lacking. One exception is the hypothesis that cellular death is mediated by oxidative stress. Oxidative stress is defined as an excess of reactive oxygen species (ROS) derived from different possible enzymatic sources. Among these, NADPH oxidases (NOX1-5) stand out as they represent the only known enzyme family that has no other function than to produce ROS. Based on data from different NOX knockout mouse models in ischemic stroke, the most relevant isoform appears to be NOX4. Here we discuss the state-of-the-art of this target with respect to stroke and open questions that need to be addressed on the path towards clinical translation. KW - NADPH oxidases (NOX) KW - stroke therapy KW - oxidative stress Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-124197 VL - 4 IS - 11 ER - TY - JOUR A1 - Brand, Susanne A1 - Amann, Kerstin A1 - Mandel, Philipp A1 - Zimnol, Anna A1 - Schupp, Nicole T1 - Oxidative DNA Damage in Kidneys and Heart of Hypertensive Mice Is Prevented by Blocking Angiotensin II and Aldosterone Receptors JF - PLOS ONE N2 - INTRODUCTION: Recently, we could show that angiotensin II, the reactive peptide of the blood pressure-regulating renin-angiotensin-aldosterone-system, causes the formation of reactive oxygen species and DNA damage in kidneys and hearts of hypertensive mice. To further investigate on the one hand the mechanism of DNA damage caused by angiotensin II, and on the other hand possible intervention strategies against end-organ damage, the effects of substances interfering with the renin-angiotensin-aldosterone-system on angiotensin II-induced genomic damage were studied. METHODS: In C57BL/6-mice, hypertension was induced by infusion of 600 ng/kg • min angiotensin II. The animals were additionally treated with the angiotensin II type 1 receptor blocker candesartan, the mineralocorticoid receptor blocker eplerenone and the antioxidant tempol. DNA damage and the activation of transcription factors were studied by immunohistochemistry and protein expression analysis. RESULTS: Administration of angiotensin II led to a significant increase of blood pressure, decreased only by candesartan. In kidneys and hearts of angiotensin II-treated animals, significant oxidative stress could be detected (1.5-fold over control). The redox-sensitive transcription factors Nrf2 and NF-κB were activated in the kidney by angiotensin II-treatment (4- and 3-fold over control, respectively) and reduced by all interventions. In kidneys and hearts an increase of DNA damage (3- and 2-fold over control, respectively) and of DNA repair (3-fold over control) was found. These effects were ameliorated by all interventions in both organs. Consistently, candesartan and tempol were more effective than eplerenone. CONCLUSION: Angiotensin II-induced DNA damage is caused by angiotensin II type 1 receptor-mediated formation of oxidative stress in vivo. The angiotensin II-mediated physiological increase of aldosterone adds to the DNA-damaging effects. Blocking angiotensin II and mineralocorticoid receptors therefore has beneficial effects on end-organ damage independent of blood pressure normalization. KW - aldosterone KW - oxidative stress KW - transcription factors KW - kidneys KW - heart KW - hypertension KW - DNA damage KW - blood pressure Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-118011 SN - 1932-6203 VL - 9 IS - 12 ER - TY - JOUR A1 - Cox-Limpens, Kimberly E. M. A1 - Vles, Johan S. H. A1 - van den Hove, Daniel L. A. A1 - Zimmermann, Luc Ji A1 - Gavilanes, Antonio W. D. T1 - Fetal asphyctic preconditioning alters the transcriptional response to perinatal asphyxia JF - BMC Neuroscience N2 - Background: Genomic reprogramming is thought to be, at least in part, responsible for the protective effect of brain preconditioning. Unraveling mechanisms of this endogenous neuroprotection, activated by preconditioning, is an important step towards new clinical strategies for treating asphyctic neonates. Therefore, we investigated whole-genome transcriptional changes in the brain of rats which underwent perinatal asphyxia (PA), and rats where PA was preceded by fetal asphyctic preconditioning (FAPA). Offspring were sacrificed 6 h and 96 h after birth, and whole-genome transcription was investigated using the Affymetrix Gene1.0ST chip. Microarray data were analyzed with the Bioconductor Limma package. In addition to univariate analysis, we performed Gene Set Enrichment Analysis (GSEA) in order to derive results with maximum biological relevance. Results: We observed minimal, 25% or less, overlap of differentially regulated transcripts across different experimental groups which leads us to conclude that the transcriptional phenotype of these groups is largely unique. In both the PA and FAPA group we observe an upregulation of transcripts involved in cellular stress. Contrastingly, transcripts with a function in the cell nucleus were mostly downregulated in PA animals, while we see considerable upregulation in the FAPA group. Furthermore, we observed that histone deacetylases (HDACs) are exclusively regulated in FAPA animals. Conclusions: This study is the first to investigate whole-genome transcription in the neonatal brain after PA alone, and after perinatal asphyxia preceded by preconditioning (FAPA). We describe several genes/pathways, such as ubiquitination and proteolysis, which were not previously linked to preconditioning-induced neuroprotection. Furthermore, we observed that the majority of upregulated genes in preconditioned animals have a function in the cell nucleus, including several epigenetic players such as HDACs, which suggests that epigenetic mechanisms are likely to play a role in preconditioning-induced neuroprotection. KW - Perinatal Asphyxia KW - oxidative stress KW - microarray KW - cerebral artery occlusion KW - ischemic brain injury KW - genomic response KW - protein aggregation KW - immediate early genes KW - neuroprotection KW - tolerance KW - rat KW - expression KW - transient global ischemia KW - ubiquitination KW - epigenetics KW - fetal preconditioning KW - neonatal brain Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-116185 VL - 15 ER - TY - JOUR A1 - Remes, Bernhard A1 - Berghoff, Bork A. A1 - Förstner, Konrad U. A1 - Klug, Gabriele T1 - Role of oxygen and the OxyR protein in the response to iron limitation in Rhodobacter sphaeroides JF - BMC Genomics N2 - Background: High intracellular levels of unbound iron can contribute to the production of reactive oxygen species (ROS) via the Fenton reaction, while depletion of iron limits the availability of iron-containing proteins, some of which have important functions in defence against oxidative stress. Vice versa increased ROS levels lead to the damage of proteins with iron sulphur centres. Thus, organisms have to coordinate and balance their responses to oxidative stress and iron availability. Our knowledge of the molecular mechanisms underlying the co-regulation of these responses remains limited. To discriminate between a direct cellular response to iron limitation and indirect responses, which are the consequence of increased levels of ROS, we compared the response of the alpha-proteobacterium Rhodobacter sphaeroides to iron limitation in the presence or absence of oxygen. Results: One third of all genes with altered expression under iron limitation showed a response that was independent of oxygen availability. The other iron-regulated genes showed different responses in oxic or anoxic conditions and were grouped into six clusters based on the different expression profiles. For two of these clusters, induction in response to iron limitation under oxic conditions was dependent on the OxyR regulatory protein. An OxyR mutant showed increased ROS production and impaired growth under iron limitation. Conclusion: Some R. sphaeroides genes respond to iron limitation irrespective of oxygen availability. These genes therefore reflect a "core iron response" that is independent of potential ROS production under oxic, iron-limiting conditions. However, the regulation of most of the iron-responsive genes was biased by oxygen availability. Most strikingly, the OxyR-dependent activation of a subset of genes upon iron limitation under oxic conditions, including many genes with a role in iron metabolism, revealed that elevated ROS levels were an important trigger for this response. OxyR thus provides a regulatory link between the responses to oxidative stress and to iron limitation in R. sphaeroides. KW - oxidative stress KW - Rhodobacter sphaeroides KW - RNAseq KW - OxyR KW - iron limitation KW - transcriptomics KW - dependent gene-expression KW - hydrogen-peroxide KW - escherichia coli Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-115357 SN - 1471-2164 VL - 15 IS - 794 ER - TY - JOUR A1 - Schoen, Christoph A1 - Kischkies, Laura A1 - Elias, Johannes A1 - Ampattu, Biju Joseph T1 - Metabolism and virulence in Neisseria meningitidis N2 - A longstanding question in infection biology addresses the genetic basis for invasive behavior in commensal pathogens. A prime example for such a pathogen is Neisseria meningitidis. On the one hand it is a harmless commensal bacterium exquisitely adapted to humans, and on the other hand it sometimes behaves like a ferocious pathogen causing potentially lethal disease such as sepsis and acute bacterial meningitis. Despite the lack of a classical repertoire of virulence genes in N. meningitidis separating commensal from invasive strains, molecular epidemiology suggests that carriage and invasive strains belong to genetically distinct populations. In recent years, it has become increasingly clear that metabolic adaptation enables meningococci to exploit host resources, supporting the concept of nutritional virulence as a crucial determinant of invasive capability. Here, we discuss the contribution of core metabolic pathways in the context of colonization and invasion with special emphasis on results from genome-wide surveys. The metabolism of lactate, the oxidative stress response, and, in particular, glutathione metabolism as well as the denitrification pathway provide examples of how meningococcal metabolism is intimately linked to pathogenesis. We further discuss evidence from genome-wide approaches regarding potential metabolic differences between strains from hyperinvasive and carriage lineages and present new data assessing in vitro growth differences of strains from these two populations. We hypothesize that strains from carriage and hyperinvasive lineages differ in the expression of regulatory genes involved particularly in stress responses and amino acid metabolism under infection conditions. KW - Neisseria meningitidis KW - virulence KW - pathometabolism KW - oxidative stress KW - glutathione KW - γ-glutamyl cycle KW - glutamate dehydrogenase KW - nitrite respiration Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-113118 ER - TY - THES A1 - Glaser, Nina T1 - Influence of natural food compounds on DNA stability T1 - Einfluss natürlicher Nahrungsbestandteile auf die DNA Stabilität N2 - Cancer is one of the leading causes of death all over the world. Malnutrition and toxic contaminations of food with substances such as mycotoxins have been thought to account for a high percentage of cancers. However, human diet can deliver both mutagens and components that decrease the cancer risk. Genomic damage could be reduced by food components through different mechanisms such as scavenging of reactive oxygen species. In the first part of this study we tried to investigate the effects of patulin and resveratrol on DNA stability in V79 cells. Patulin is a mycotoxin, which is frequently found in spoiled apples and other fruits. The WHO has established a safety level of 50 µg/L, which is indeed not observed by all manufacturers. The acute toxicity of patulin in high concentrations is well known, however its potential carcinogenicity is still a matter of debate. Therefore we wanted to investigate further steps in the mechanism of patulin-induced genotoxicity. Patulin caused the formation of micronuclei and nucleoplasmic bridges in a dose-dependent manner. Further analysis revealed that patulin induced both kinetochore-negative and positive micronuclei. Time course of incubation indicate a new mechanism for patulin-induced nucleoplasmic bridge formation. We hypothized a mechanism via cross-linking of DNA, which was confirmed by a modified version of comet assay. Incubations of cells with patulin led to an increased number of multinucleated cells and multipolar mitoses. Cell cytometry revealed a G2 arrest by patulin, which might explain the amplification of centrosomes and patulin-induced aneuploidy. Patulin cause a dose-dependent DNA damage in comet assay which was influenced by the cellular GSH content. However, an induction of oxidative stress was just seen with higher concentrations of patulin. Levels of cellular glutathione were increased after 24 h incubation indicating an adaptive response to patulin-induced stress. There is growing interest in polyphenols such as resveratrol which have shown many positive effects on human health. The beneficial properties are partially attributed to their ability to scavenge reactive oxygen species. Co-incubation of V79 cells with patulin and 10 µM of the antioxidant resveratrol led to a slight reduction of micronucleus frequency compared to cells which were just treated with patulin. However, in higher concentrations resveratrol themselves caused the formation of micronuclei in V79 cells. Kinetochore analysis indicated only clastogenic properties for resveratrol but no disturbance of mitosis. The antioxidant properties of resveratrol were shown in ferric reducing antioxidant power (FRAP) assay. However, in cellular system resveratrol in higher concentrations revealed also prooxidative properties, as shown in 2,7-dichlordihydrofluorescein (DCF) assay. The increased level of glutathione after resveratrol treatment might reflect an adaptive response to resveratrol-induced oxidative stress. For the second part of this thesis we investigated the effects of an anthocyanin-rich grape extract on hypertensive Ren-2 rats. Ren-2 rats are an accepted genetically modified rat model for the investigation of hypertension and increased oxidative stress. We divided 23 female Ren-2 rats into three groups. One group was fed with an anthocyanin-rich Dacapo grape extract, one group was treated with the angiotensin converting enzyme (ACE) inhibitor ramipril and the third group was kept without medication during the experiment. After one week untreated group showed a clear increase in systolic and diastolic blood pressure compared to the ramipril treated rats. This was in part attenuated in the animals fed with anthocyanin-rich Dacapo grape extract. Effects on blood pressure were also reflected in an increased thirst of untreated and extract fed animals. Comet assay with cells of kidney and liver revealed a slight protective impact of Dacapo extract on DNA damage compared to the other groups. Similar results were obtained after evaluation of ɣ-H2AX-staining of kidney and heart sections. However, in the small intestine oppositional effects were seen, indicating an increased number of double strand breaks probably due to the high local concentration of polyphenols after oral ingestion. Antioxidative properties of the extract were shown in FRAP assay. However, this effect was not reflected in an increased antioxidative capacity in serum or a protective impact in the dihydroethidium (DHE) assay. The extract showed protective effects on DNA damage in comet assay and ɣ-H2AX-staining, but was not able to reduce hypertension back to the control level of ramipril treated animals. High local concentrations could also result in an increased damage of the affected tissue. Therefore, the administration of such concentrated compounds should be handled with care. N2 - Krebs ist eine der häufigsten weltweiten Todesursachen. Fehlernährung und Kontaminationen der Nahrungsmittel mit Toxinen wie Schimmelpilzgift tragen zu einem hohen Prozentsatz zu Krebserkrankungen bei. Allerdings enthält die Nahrung neben Mutagenen auch Bestandteile, die dazu beitragen das Krebsrisiko zu senken. Schäden am Genom können durch Nahrungsbestandteile über verschiedene Mechanismen, wie zum Beispiel das Abfangen von freien Radikalen reduziert werden. Im ersten Teil dieser Studie haben wir versucht die Effekte von Patulin und Resveratrol auf die DNA Stabilität von V79 Zellen zu untersuchen. Patulin ist ein Schimmelpilztoxin, welches häufig in verfaulten Äpfeln und anderen Früchten gefunden wird. Die WHO hat einen Grenzwert von 50 µg/L festgelegt, der jedoch nicht von allen Herstellern eingehalten wird. Die akute Giftwirkung von Patulin in hohen Dosen ist gut bekannt, wohingegen seine potentielle Kanzerogenität immer noch umstritten ist. Daher wollten wir weitere Schritte der Patulin induzierten Genotoxizität aufdecken. Patulin führte zu einer dosisabhängigen Bildung von Mikrokernen und Nucleoplasmic Bridges. Weitere Untersuchungen zeigten, dass Patulin sowohl kinetochor-positive wie auch kinetochor-negative Mikrokerne verursacht. Bei der Analyse des Zeitverlaufs einer Patulininkubation deutete sich ein neuer Mechanismus für die Patulin induzierte Bildung von Nucleoplasmic Bridges an. Wir haben die Hypothese einer Quervernetzung von DNA-Strängen aufgestellt, die durch eine modifizierte Version des Comet Assays bestätigt wurde. Die Inkubation mit Patulin führte zudem zu einer erhöhten Anzahl von vielkernigen Zellen und multipolaren Mitosen. Mittels Durchflusszytometrie konnten wir einen durch Patulin verursachten G2 Arrest nachweisen, der die Amplifikation von Centrosomen und die Patulin induzierte Aneuploidie erklären könnte. Patulin verursachte einen dosisabhängigen Schaden im Comet Assay, der durch den zellulären Glutathiongehalt beeinflusst ist. Eine Auslösung von oxidativem Stress wurde dagegen erst bei höheren Konzentrationen an Patulin beobachtet. Der zelluläre Gluathiongehalt war nach 24 h Inkubationszeit erhöht, was auf eine adaptive Antwort auf den durch Patulin verursachten zellulären Stress hindeutet. Polyphenole wie Resveratrol gewinnen zunehmend an Bedeutung, da zahlreiche positive Effekte auf die menschliche Gesundheit bewiesen wurden. Diese vorteilhaften Eigenschaften werden zum Teil ihrer Eigenschaft als Radikalfänger zugeschrieben. Die Co-Inkubation von V79 Zellen mit Patulin und Resveratrol führte zu einer leichten Reduktion der Mikrokernfrequenz im Vergleich zu Zellen, die nur mit Patulin inkubiert wurden. Allerdings löste Resveratrol in höheren Konzentrationen selbst die Bildung von Mikrokernen aus. Die Kinetochor-Analyse zeigte für Resveratrol clastogene Eigenschaften aber keine störende Effekte auf den Ablauf der Mitose. Die antioxidativen Eigenschaften von Resveratrol wurden im FRAP (ferric reducing antioxidant power) -Assay nachgewiesen. Im Gegensatz dazu wurden im zellulären System mittels DCF (2,7-Dichlordihydro-fluorescein) -Assay in höheren Konzentrationen auch prooxidative Eigenschaften festgestellt. Der erhöhte zelluläre Glutathionspiegel nach Resveratrol-Behandlung könnte dabei auf eine adaptive Anwort auf den durch Resveratrol ausgelösten oxidativen Stress hindeuten Im zweiten Teil dieser Doktorabeit haben wir die Effekte eines anthocyanreichen Traubenextrakts auf hypertensive Ren-2 Ratten untersucht. Ren-2 Ratten sind ein anerkanntes genetisch modifiziertes Rattenmodell zur Untersuchung von Bluthochdruck und erhöhtem oxidativem Stress. Wir haben 23 weibliche Ren-2 Ratten in 3 Gruppen geteilt. Eine Gruppe wurde mit einem anthocyan-reichen Dacapo Traubenextrakt gefüttert, eine Gruppe wurde mit dem ACE (angiotensin converting enzyme) Inhibitor Ramipril behandelt und eine dritte Gruppe wurde während dem Experiment nicht medikamentös behandelt. Nach einer Woche zeigte die nicht therapierte Gruppe einen deutlichen Anstieg des systolischen und diastolischen Blutdrucks. Dieser Anstieg war bei der mit anthocyanreichem Dacapo Traubenextrakt gefütterten Gruppe abgeschwächt. Die Effekte auf den Blutdruck spiegelten sich auch in einer erhöhten Trinkmenge der unbehandelten und mit Extrakt behandelten Tiere wider. Ein Comet Assay mit Nieren- und Leberzellen zeigte einen schwachen schützenden Einfluß des Dacapoextrakts auf den DNA Schaden im Vergleich zu den anderen Behandlungsgruppen. Ähnliche Ergebnisse wurden auch bei der Auswertung der ɣ-H2AX Färbung in Nieren- und Herzschnitten erzielt. Im Dünndarm wurden dagegen gegensätzliche Effekte beobachtet, die auf eine erhöhte Doppelstrangfrequenz durch die hohe lokale Konzentration an Polyphenolen nach oraler Aufnahme hindeuten. Die antioxidative Eigenschaften des Extrakts wurden im FRAP_Assay nachgewiesen. Diese Effekte spiegelten sich jedoch nicht in einer erhöhten antioxidativen Kapazität des Serums oder einem schützenden Effekt im DHE-Assay wider. Der Extrakt zeigte schützende Eigenschaften im Comet Assay und in der ɣ-H2AX-Färbung, war aber nicht in der Lage den Bluthochdruck auf das Kontrollniveau der Ramipril-behandelten Tiere herabzusenken. Hohe lokale Konzentrationen können auch zu einem erhöhten Schaden des betroffenen Gewebes führen. Daher sollte die Anwendung solcher hochkonzentrierter Präparate mit Vorsicht bedacht werden. KW - Patulin KW - Anthocyane KW - Resveratrol KW - Oxidativer Stress KW - Mutagenität KW - Genotoxizität KW - Patulin KW - anthocyanins KW - resveratrol KW - genotoxicity KW - oxidative stress Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-72872 ER - TY - THES A1 - Queisser, Nina T1 - Oxidative and nitrosative stress induced by the mineralocorticoid aldosterone - Mechanism of induction and role of signal transduction pathways and transcription factors T1 - Oxidativer und nitrosativer Stress induziert durch das Mineralocorticoid Aldosteron - Mechanismen der Induktion und Rolle von Signalwegen und Transkriptionsfaktoren N2 - Several epidemiological studies found that hypertensive patients have an increased risk to develop kidney cancer. Hyperaldosteronism frequently results in arterial hypertension and contributes to the development and progression of kidney injury, with reactive oxygen species (ROS) playing an important role. ROS are thought to be associated with many pathological conditions such as cancer and other disorders, like cardiovascular complications , which often go along with hypertension. The aim of the present work was to investigate whether the effects of elevated aldosterone concentrations might be involved in the increased cancer incidence of hypertensive individuals. First, the potential capacity of aldosterone to induce oxidative stress and DNA damage was investigated in vitro and in vivo. In LLC-PK1 porcine kidney cells and MDCK canine kidney cells the significant formation of ROS, and especially of superoxide (O2˙ˉ) was assessed. With two genotoxicity tests, the comet assay and the micronucleus frequency test, the DNA damaging potential of aldosterone was quantified. In both genotoxicity tests a dose-dependent increase in aldosterone-induced structural DNA damage was observed. Oxidative stress and DNA damage were prevented by antioxidants, suggesting ROS as a major cause of DNA damage. Furthermore, the oxidatively modified DNA lesion 8-oxo-7,8-dihydro-2´-deoxyguanosine (8-oxodG), was found to be significantly elevated. In kidneys of rats with desoxycorticosterone acetate (DOCA)/salt-induced hypertension, which is a model of severe mineralocorticoid-dependent hypertension, elevated levels of ROS and superoxide were found, compared to kidneys of sham rats. Also DNA strand breaks, measured with the comet assay and double strand breaks, visualized with antibodies against the double strand break-marker gamma-H2AX were significantly elevated in kidneys of DOCA/salt-treated rats. In addition, significantly increased amounts of 8-oxodG were detected. Proliferation of kidney cells was found to be increased, which theoretically enables the DNA damage to manifest itself as mutations, since the cells divide. Second, the effects of aldosterone on the activation of transcription factors and signaling pathways were investigated. A significant activation of the potentially protective transcription factor Nrf2 was observed in LLC-PK1 cells. This activation was triggered by an increase of ROS or reactive nitrogen species (RNS). In response to oxidative stress, glutathione synthesis and detoxifying enzymes, such as the subunits of the glutathione-cysteine-ligase or heme oxygenase 1 were rapidly induced after 4 h. Nevertheless, after 24 h a decrease of glutathione levels was observed. Since ROS levels were still high after 24 h, but Nrf2 activation decreased, this adaptive survival response seems to be transient and quickly saturated and overwhelmed by ROS/RNS. Furthermore, Nrf2 activation was not sufficient to protect cells against oxidative DNA damage, because the amounts of double strand breaks and 8-oxodG lesions steadily rose up to 48 h of aldosterone treatment. The second transcription factor that was time- and dose-dependently activated by aldosterone in LLC-PK1 and MDCK cells was NF-kappaB. Furthermore, a significant cytosolic and nuclear activation of ERK was detected. Aldosterone induced the phosphorylation of the transcription factors CREB, STAT1 and STAT3 through ERK. Third, the underlying mechanisms of oxidant production, DNA damage and activation of transcription factors and signaling pathways were studied. Aldosterone exclusively acted via the MR, which was proven by the MR antagonists eplerenone, spironolactone and BR-4628, whereas the glucocorticoid receptor (GR) antagonist mifepristone did not show any effect. Furthermore, aldosterone needed cytosolic calcium to exert its negative effects. Calcium from intracellular stores and the influx of calcium across the plasma membrane was involved in aldosterone signaling. The calcium signal activated on the one hand, the prooxidant enzyme complex NAD(P)H oxidase through PKC, which subsequently caused the generation of O2˙ˉ. On the other hand, nitric oxide synthase (NOS) was activated, which in turn produced NO. NO and O2˙ˉ can react to the highly reactive species ONOO- that can damage the DNA more severely than the less reactive O2˙ˉ. In the short term, the activation of transcription factors and signaling pathways could be a protective response against aldosterone-induced oxidative stress and DNA damage. However, a long-term NF-B and ERK/CREB/STAT activation by persistently high aldosterone levels could unfold the prosurvival activity of NF-kappaB and ERK/CREB/STAT in aldosterone-exposed cells. DNA damage caused by increased ROS might become persistent and could be inherited to daughter cells, probably initiating carcinogenesis. If these events also occur in patients with hyperaldosteronism, these results suggest that aldosterone could be involved in the increased cancer incidence of hypertensive individuals. N2 - Mehrere epidemiologische Studien haben ein erhöhtes Nierenkrebsrisko bei Patienten mit Bluthochdruck aufgedeckt. Hyperaldosteronismus führt oft zu arteriellem Bluthochdruck und trägt zur Entwicklung und zum Fortschreiten von Nierenschäden bei, wobei reaktive Sauerstoffspezies (ROS) eine wichtige Rolle spielen. Immer häufiger werden ROS mit Krankheitsbildern wie Krebs und kardiovaskulären Erkrankungen, die mit Bluthochdruck einhergehen, in Verbindung gebracht. Das Ziel dieser Arbeit war es, zu untersuchen, ob erhöhte Aldosteronkonzentrationen an dem gesteigerten Krebsrisiko von hypertensiven Patienten beteiligt sein könnten. Zunächst wurde die potentielle Kapazität von Aldosteron, oxidativen Stress und DNA-Schaden in vitro und in vivo induzieren zu können, untersucht. In der Schweine-Nierenzelllinie LLC-PK1 und der Hunde-Nierenzelllinie MDCK wurde die Entstehung von ROS und speziell die Bildung von Superoxid (O2˙ˉ) nachgewiesen. Das gentoxische Potential von Aldosteron wurde mit zwei Genotoxizitätstests, dem Comet Assay und dem Mikrokernfrequenztest bestimmt. In beiden Genotoxizitätstests konnte ein dosis-abhängiger Anstieg des strukturellen DNA-Schadens beobachtet werden. Antioxidantien konnten den oxidativen Stress und die DNA-Schäden verringern, was annehmen lässt, dass ROS die Hauptursache für die Entstehung der DNA-Schäden sind. Darüberhinaus wurden signifikant erhöhte Mengen der oxidativ modifizierten DNA Läsion 8-Oxo-7,8-dihydro-2´-deoxyguanosin (8-oxodG) gefunden. In Nieren von Ratten mit Desoxycorticosteron-Acetat (DOCA) und Salz-induziertem Bluthochdruck, ein Modell für massiven Mineralocorticoid-induzierten Bluthochdruck, wurde ebenfalls eine erhöhte Bildung von ROS und O2˙ˉ in Nieren von DOCA/Salz-Ratten im Vergleich zu Sham-Ratten beobachtet. Auch im Comet Assay erfasste DNA-Strangbrüche und Doppelstrangbrüche, die mit Hilfe von Antikörpern gegen den Doppelstrangbruchmarker gamma-H2AX sichtbar gemacht wurden, waren in den Nieren der DOCA/Salz-behandelten Ratten signifikant erhöht. Weiterhin wurden erhöhte 8-oxodG-Spiegel in DOCA/Salz-Ratten beobachtet. Auch eine erhöhte Proliferationsrate in DOCA/Salz-behandelten Ratten konnte festgestellt werden, was theoretisch dazu führen könnte, dass sich die DNA-Schäden als Mutationen manifestieren, da sich die Zellen teilen. Im zweiten Teil der Arbeit wurde der Einfluss von Aldosteron auf die Aktivierung von Transkriptionsfaktoren und Signalwegen untersucht. Zunächst konnte die Aktivierung des potentiell schützenden Transkriptionsfaktors Nrf2 in LLC-PK1 Zellen mittels electrophoretic mobility shift assay (EMSA) beobachtet werden. Diese Aktivierung wurde durch den Anstieg an ROS und reaktiven Stickstoffspezies (RNS) ausgelöst. Als Antwort auf den oxidativen Stress, wurde die Glutathion-Synthese und detoxifizierende Enzyme, wie die Untereinheiten der Glutathion-Cystein-Ligase oder Hämoxygenase 1, nach 4 Stunden rasch hochreguliert. Nichtsdestotrotz konnte nach 24 Stunden eine Abnahme des Glutathionspiegels festgestellt werden. Da die Konzentration an ROS nach 24 Stunden immer noch signifikant erhöht war, die Aktivierung von Nrf2 allerdings stark zurückgegangen ist, scheint diese adaptive Überlebensstrategie nur kurzfristig, und somit schnell durch ROS/RNS gesättigt zu sein. Weiterhin war die Aktivierung von Nrf2 nicht ausreichend, um die Zellen vor dem durch Aldosteron-induzierten DNA-Schaden zu schützen, da Doppelstrangbrüche, sowie 8-oxodG-Läsionen bei bis zu 48-stündiger Inkubation mit Aldosteron stetig anstiegen. Der zweite Transkriptionsfaktor, der zeit- und dosisabhängig durch Aldosteron aktiviert wurde, war NF-kappaB. Ausserdem wurde die cytosolische und nukleäre Aktivierung von ERK nachgewiesen. Aldosteron induzierte weiterhin die Phosphorylierung der Transkriptionsfaktoren CREB, STAT1 und STAT3 durch ERK. Im dritten Teil dieser Arbeit wurden die zugrundeliegenden Mechanismen der Entstehung von ROS/RNS, des DNA-Schadens und der Aktivierung von Transkriptionsfaktoren untersucht. Aldosteron wirkte ausschließlich über den MR, bewiesen durch Einsatz der MR-Antagonisten Eplerenon, Spironolakton und BR-4628. Der Glucocorticoid-Rezeptor-Antagonist Mifepriston zeigte dagegen keinen Effekt. Weiterhin benötigte Aldosteron cytosolisches Calcium, um seine negativen Effekte auszuüben. Es waren intrazelluäres Calcium, sowie ein Calciuminflux über die Plasmamembran am Aldosteronsignal beteiligt. Einerseits wurde der prooxidative Enzymkomplex NAD(P)H-Oxidase von Calcium durch die Proteinkinase C (PKC) aktiviert, was wiederum zur Bildung von O2˙ˉ führte. Andererseits kam es durch erhöhtes cytosolisches Calcium zur Aktivierung der NO-Synthase (NOS), welche daraufhin Stickoxid (NO) produzierte. NO und O2˙ˉ können zu dem hochreaktiven Peroxynitrit (ONOO-) reagieren, welches die DNA mehr schädigen kann als das etwas weniger reaktive O2˙ˉ. Kurzfristig könnte die Aktivierung der Transkriptionsfaktoren und Signalwege eine schützende Wirkung gegen den durch Aldosteron-induzierten oxidativen Stress und DNA-Schaden in den Zellen haben. Allerdings kann eine länger anhaltende Aktivierung von NF-kappaB und ERK/CREB/STAT durch permanent hohe Aldosteronspiegel zur Induktion einer Überlebensstrategie durch NF-kappaB und ERK/CREB/STAT in Aldosteron-exponierten Zellen führen. Der DNA-Schaden, der durch erhöhte ROS-Spiegel entsteht, könnte persistent und somit an Tochterzellen weitervererbt werden, was eventuell zur Entstehung von Krebs beitragen könnte. Falls diese Effekte auch in Patienten mit Hyperaldosteronismus gefunden werden können, dann könnte Aldosteron an der erhöhten Krebsinzidenz bei Bluthochdruck beteiligt sein. KW - Aldosteron KW - Oxidativer Stress KW - DNS-Schädigung KW - NADPH-Oxidase KW - Stickstoffoxidsynthase KW - Aldosteron KW - Oxidativer Stress KW - Nitrosativer Stress KW - DNA-Schaden KW - Transkriptionsfaktoren KW - aldosterone KW - oxidative stress KW - nitrosative stress KW - DNA damage KW - transcription factors Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-53566 ER - TY - THES A1 - Padmapriya, Ponnuswamy T1 - Insight into oxidative stress mediated by nitric oxide synthase (NOS) isoforms in atherosclerosis N2 - The principle product of each NOS is nitric oxide. However, under conditions of substrate and cofactor deficiency the enzymes directly catalyze superoxide formation. Considering this alternative chemistry of each NOS, the effects of each single enzyme on key events of atherosclerosis are difficult to predict. Here, we evaluate nitric oxide and superoxide production by all three NOS isoforms in atherosclerosis. ESR measurements of circulating and vascular wall nitric oxide production showed significantly reduced nitric oxide levels in apoE/eNOS double knockout (dko) and apoE/iNOS dko animals but not in apoE/nNOS dko animals suggesting that eNOS and iNOS majorly contribute to vascular nitric oxide production in atherosclerosis. Pharmacological inhibition and genetic deletion of eNOS and iNOS reduced vascular superoxide production suggesting that eNOS and iNOS are uncoupled in atherosclerotic vessels. Though genetic deletion of nNOS did not alter superoxide production, acute inhibition of nNOS showed that nNOS contributes significantly to superoxide production. In conclusion, uncoupling of eNOS occurs in apoE ko atherosclerosis but eNOS mediated superoxide production does not outweigh the protective effects of eNOS mediated nitric oxide production. We show that although nNOS is not a major contributor of the vascular nitric oxide formation, it prevents atherosclerosis development. Acute inhibition of nNOS showed a significant reduction of superoxide formation suggesting that nNOS is uncoupled. The exact mechanism of action of nNOS in atheroprotection is yet to be elucidated. Genetic deletion of iNOS reduced NADPH oxidase activity. Thus, iNOS has both direct and indirect proatherosclerotic effects, as it directly generates both nitric oxide and superoxide simultaneously resulting in peroxynitrite formation and indirectly modulates NADPH oxidase activity. We hypothesize that eNOS is coupled in the disease free regions of the vessel and contributes to nitric oxide generation whereas in the diseased region of the vessel it is uncoupled to produce superoxide (Figure 16). nNOS expressed in the smooth muscle cells of the plaque contributes to the local superoxide generation. iNOS expressed in smooth muscle cells and leukocytes of the plaque generates superoxide and nitric oxide simultaneously to produce the strong oxidant peroxynitrite. N2 - Stickstoffmonoxid (NO) ist das prinzipielle Produkt aller Stickstoffmonoxid-Synthasen (NOS). Im Falle eines Mangels an Substrat (L-arginin) und Kofaktoren (Tetrahydrobiopterin, BH4) katalysieren die NOS-Enzyme direkt Superoxid (O2-). Diese Veränderung in der Radikalproduktion wird auch als Entkopplung der NOS bezeichnet. Die alternative Produktion von NO oder O2- durch die NOS bedingen, dass eine Voraussage über die Schlüsselfunktion der einzelnen Enzyme in der Entstehung der Atherosklerose schwierig ist. In unserer Studie evaluieren wir die Produktion von NO sowie O2- in atherosklerotischen Läsionen von apoE ko Mäusen und apoE/NOS doppel knockout (dko) Mäusen denen jeweils eine NOS-Isoform fehlt. Elektronen Spin Resonanz (ESR) Messungen konnten eine signifikante Reduktion sowohl des zirkulierenden, als auch der Gefäßwand eigenen Produktion von NO in apoE/eNOS dko und apoE/iNOS dko Mäusen zeigen, nicht jedoch in apoE/nNOS dko Mäusen. Dies lässt darauf schließen, dass eNOS und iNOS den hauptsächlichen Anteil der vaskulären NO-Produktion in atherosklerotischen Läsionen bewerkstelligen. Die pharmakologische Inhibierung wie auch die genetische Deletion von eNOS und iNOS führten ebenfalls zu einer reduzierten vaskulären O2- produktion, was die partielle Entkopplung beider Enzyme in atherosklerotisch veränderten Gefäßen nahe legt. Obwohl die chronische genetische Deletion von nNOS in apoE/nNOS dko die O2- Produktion nicht verändert, zeigte sich bei der akuten pharmakologischen Inhibierung von nNOS (durch L-NAANG) eine maßgebliche Beteiligung von nNOS an der O2- produktion in apoE ko Mäusen. Schlussfolgernd lässt sich sagen, dass in atherosklerotischen Gefäßen von apoE ko Tieren eine Entkopplung von eNOS statt findet, diese jedoch zu keinem Ausgleich der protektiven Effekte der eNOS vermittelten NO-Produktion führt. Unsere Ergebnisse in apoE/nNOS dko Mäusen zeigen eine atheroprotektive Rolle der nNOS, die sich nicht allein durch eine lokale, vaskuläre NO-Produktion durch das Enzym erklären lässt. Wir postulieren weitere systemisch atheroprotektive Eigenschaften der nNOS. Die signifikante Reduktion der Superoxidproduktion durch eine akute Inhibierung der nNOS weist auf eine Entkopplung der nNOS hin. Der exakte Wirkungsmechansimus von nNOS in der Atheroskleroseprävention ist weiterhin noch zu eruieren. Die genetische Deletion von iNOS führt zu einer reduzierten Aktivität der NADPH-Oxidase. Demnach sind für iNOS direkte sowie indirekte atherosklerosefördernde Effekte anzunehmen, da sie auf direktem Wege gleichzeitig NO und O2- produziert, was in einer Peroxynitritbildung resultiert. Wir stellen die Hypothese auf, dass eNOS in den läsionsfreien Gefäßregionen gekoppelt ist und dort seine atheroprotektiven Effekte durch die NO-Produktion vermittelt, während die eNOS in atherosklerotischen Läsionen entkoppelt vorliegt und hier O2- produziert (Fig. 16). iNOS, welches vor allem in den Plaques, in glatten Muskelzellen und Leukozyten zu finden ist, produziert gleichzeitig hohe Konzentrationen von O2- und NO, die als gemeinsames Endprodukt das stark oxidierende Peroxynitrit ergeben und die von uns dokumentierte proatherosklerotische Wirkung der iNOS vermittelt. KW - atherosclerosis KW - oxidative stress KW - Nitric oxide synthase KW - Atherosklerose KW - Stickstoffmonoxid Synthase KW - atherosclerosis KW - oxidative stress KW - Nitric oxide synthase Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-30659 ER - TY - THES A1 - Nhan, Pham Phuoc T1 - Accumulation and biological activity of oxidized lipids in Anabaena PCC 7120 T1 - Akkumulation und biologische Aktivität von oxidierten Fettsäuren in Anabaena PCC 7120 N2 - Oxylipine sind wichtige biologisch aktive Verbindungen, die entscheidende Rollen in der Abwehr, dem Wachstum, der Entwicklung und der Reproduktion von Pflanzen und Tieren spielen. Oxylipine können entweder über enzymatische Wege oder eine Radikal-katalysierte Reaktion gebildet werden. Enzymatische und nicht-enzymatische Oxidationsprodukte der Arachidonsäure (C20:4) in Tieren sind Prostaglandine und Isoprostane. In Pflanzen werden ausgehend von der -Linolensäure (C18:3) über einen enzymatischen Weg OPDA und Jasmonsäure und durch Radikal-katalysierte Reaktion Phytoprostane gebildet. Die Membranen von Cyanobakterien enthalten, ähnlich denen von Pflanzen, einen großen Anteil an mehrfach ungesättigten Fettsäuren, ca. 25% der gesamten Fettsäuren. Biosynthese und Funktionen der Oxylipine wurden an zwei Modell-Cyanobakterien, Anabaena PCC 7120 und Synechocystis PCC 6803 untersucht: 1. Das fadenförmige Cyanobakterium Anabaena PCC 7120 kann Phytoprostane Typ I und II sowie Hydroxyfettsäuren ähnlich wie Pflanzen produzieren aber die enzymatische Ausstattung zur Bildung von Jasmonaten (12-oxo-Phytodiensäure und Jasmonsäure) und Prostaglandinen ist nicht vorhanden. Die erhaltenen Daten stellen den ersten Nachweis für das Vorkommen von Phytoprostanen in Cyanobakterien bzw. bei Prokaryonten dar. 2. Durch GC-MS Analyse wurden E1- and F1-Phytoprostane in Anabaena PCC 7120 in freier und veresterter Form detektiert. Die Spiegel sind vergleichbar mit denen in Pflanzen und lagen im Bereich von ng/g TG. PPF1 ließen sich nicht in einwöchigen Kulturen nachweisen, die Spiegel in sechswöchigen Kulturen lagen bei 142 ng/l. Die Spiegel von PPE1 waren hingegen in ein- und sechswöchigen Kulturen ähnlich und lagen bei ca. 20 ng/g TG. Die Mengen an freien PPE1 in den Zellen waren mit 80.5  23.6 etwa viermal höher als die von PPF1 mit 24.1  10.9 ng/g TG. Allerdings gab es keine signifikanten Unterschiede in den Spiegeln an gesamten PPF1 und PPE1 in den Zellen, sie lagen im Bereich von 150 bis zu ca. 200 ng/g TG. 3. Die Akkumulation von Phytoprostanen in Anabaena ist induzierbar. Nach der Kombination von oxidativem Stress (200 µM H2O2 oder 10 µM CuSO4) und hoher Lichtintensität (330 µE.m-2.s-1) für 8 h stiegen die Spiegel an gesamten PPE1 und PPF1 um den Faktor 2 bis 4 an. Interessanterweise führte im Gegensatz zu höheren Pflanzen die Applikation von oxidativem Stress oder hoher Lichtintensität alleine nicht zur Induktion der Phytoprostanakkumulation in diesen Cyanobakterien. 4. Eine Vorbehandlung von Anabaena Zellen mit exogenen Phytoprostanen führte zu einer erhöhten Toleranz gegenüber oxidativem Stress. Alle Phytoprostane außer PPE1 zeigten einen Schutzeffekt. Eine Mischung von PPA1 Typ I und II ergab den höchsten Schutzeffekt. Eine Vorinkubation von Anabena Zellen mit 100 µM PPA1–type I/II für 16 h schützte 84.2% beziehungsweise 77.5% der Zellen vor einer anschießenden lethalen Applikation von 1 mM H2O2 beziehungsweise 50 µM CuSO4 für 5 h. Ohne eine Oxylipin-Vorinkubation starben etwa 98% der Zellen. Überraschenderweise ergab auch die Vorbehandlung mit anderen, enzymatisch gebildeten Oxylipinen aus Tieren und Pflanzen einen Schutzeffekt, der allerdings nur 10 bis 30% betrug. Dagegen schützte eine Phytoprostan-Vorbehandlung nicht Pseudomonas syringae und Escherichia coli gegen toxische Mengen von Wasserstoffperoxid. Allerdings fehlen in den Membranen dieser Bakterien mehrfach ungesättigte Fettsäuren und deshalb endogen oxydierte Lipide. 5. Eine exogene Applikation von 100 µM PPF1 oder 1,5 mM H2O2 führte in Anabaena nicht zu einer Induktion der Expression des isiA Gens. Oxylipin-Behandlungen zeigten auch keine Wirkung auf Shinorin- und Tocopherol-Spiegel in Anabaena. Die Applikation von 100 µM PPF1 für 6 h führte aber zu Änderungen im Proteinmuster in Anabaena. Der größte Teil der differentiellen Proteine wurde durch PPF1 herunterreguliert. Bei vielen dieser Proteine handelt es sich um photosynthetische Proteine. Da ein oxidativer Stress nur in der Kombination mit hoher Lichtintensität die Lipidperoxidation erhöht, könnte die negative Regulation der Photosynthese nach Erkennung von oxydierten Lipiden (Phytoprostanen) eine Überlebens-Strategie sein um Schäden durch peroxidierte Lipide zu vermeiden. 6. Tote Pflanzen könnten eine hauptsächliche Quelle der exogenen Phytoprostane in der natürlichen Umgebung von Anabaena sein. Trockenes Heu gibt PPE1 und PPF1 (11 µg/g TG) an die wässerige Umgebung ab. Anabaena ist ein typisches Cyanobakterium in Reisfeldern. Nach der Ernte bleiben meist die nicht genutzten Teile der Reispflanzen auf dem Feld. Diese könnten Phytoprostane abgeben, die wiederum einen Einfluß auf die Cyanobakterien im Reis-Ökosystem haben könnten. 7. Eine neue Kategorie von Oxylipinen, die Phytoprostane Typ III und IV, wurden in vitro identifiziert und quantifiziert. Die beiden Haupt-Phytoprostane, PPE1 und PPF1 (Typ III und IV), können durch die Autoxidation der -Linolensäure oder des Borretschsamenöls (enthält 25% der -Linolensäure) gewonnen werden. Nach 12 Tagen Autoxidation und anschließender Hydrolyse wurden aus 1 g Borretschsamenöl 112,71 ± 1,93 µg PPF1 und 3,80 ± 0,14 mg PPE1 isoliert. PPB1 und PPA1 (Typ III und IV) wurden durch Isomerisierung und Dehydratisierung von PPE1 hergestellt. Die Ausbeute von PPB1 lag bei 1,71 ± 0,04 mg/g Öl (Typ III) und 2,09 ± 0,12 mg/g Öl (Typ IV), die von PPA1 lag bei 8,38 ± 0,35 µg/g und 10,18 ± 0,30 µg/g Öl. 8. Es wurde eine schnelle HPLC-MS/MS Methode für die Analytik der Phytoprostane und Phytohormone entwickelt. Diese Methode wurde für die Quantifizierung von freien und veresterten E1- and F1-Phytoprostane Typ III und IV in Synechocystis PCC 6803 angewendet. Die Phytoprostane Typ III und IV sind in vivo in freier und veresterter Form vorhanden. Die Spiegel der gesamten PPE1 Typ III und IV in Synechocystis sind mindestens doppelt so hoch wie die von PPF1. Im Gegensatz zu Anabaena, waren PPE1 und PPF1 in ein- und sechswöchigen Kulturen von Synechocystis detektierbar. Die Spiegel an freien PPF1 im Medium (231,8 ± 36,2 ng/l) und in den Zellen (164,9 ± 15,2 ng/g TG) waren niedriger als die von PPE1 (1003,3 ± 365,2 ng/l und 2331,0 ± 87,7 ng/g TG). N2 - Oxylipins are important biological active compounds that play essential roles in defense, growth, development, and reproduction of plants and animals. Oxylipins are formed either by enzymatic pathways or radical catalyzed reaction from polyunsaturated fatty acids. Products of oxidation of arachidonic acid (C20:4) in animals by enzymatic and non-enzymatic pathways are prostaglandins and isoprostanes, respectively. In plants, radical catalyzed reaction of -linolenic acid (C18:3) forms phytoprostanes and enzymatic oxidation of this fatty acid produces OPDA and jasmonic acid. Like plants, cyanobacterial membranes contain a high ratio of polyunsaturated fatty acid, about 25% of total fatty acids. Oxylipin biosynthesis and function was studied in two model cyanobacteria, Anabaena PCC 7120 and Synechocystis PCC 6803, for the first time: 1. The filamentous cyanobaterium Anabaena PCC 7120 can naturally produce phytoprostanes type I and II as well as hydroxy fatty acids like in plants but lacks the enzymatic capacity to form jasmonates (12-oxo-phytodienoic acid and jasmonic acid) and prostaglandins. Data obtained provide the first evidence for the occurence of phytoprostanes in cyanobacteria as well as in the baterial kingdom. 2. By GC-MS analysis, the E1- and F1-phytoprostanes in Anabaena PCC 7120 were detected both in free and esterified form. Their levels are comparable with those in plants, in the range of ng/g DW. In one week old cultures, there was no evidence of PPF1 in the medium but its level accumulated up to 142 ng/l in six weeks old cultures. In contrast, PPE1 was stable over time, about 20 ng/g DW. Free cellular PPE1 was found about 4 times higher than that of PPF1, 80.5  23.6 and 24.1  10.9 ng/g DW, respectively. However, there was no significant difference in the total cellular levels of PPF1 and PPE1, ranging from 150 to about 200 ng/g DW. 3. Phytoprostanes are inducible in Anabaena. In the combination of oxidative stress (200 µM H2O2 or 10 µM CuSO4) with high light intensity (330 µE.m-2.s-1) for 8 h, levels of total cellular PPE1 and PPF1 were increased about 2 to 4 times. Interestingly, unlike in higher plants, application of oxidative stress or high light intensity alone showed no phytoprostaneous induction in this cyanobacterium. 4. When Anabaena cells were treated with phytoprostanes, Anabaena cells became remarkably resistant against subsequently applied – otherwise lethal – oxidative stress. All phytoprostanes displayed a high protective effect except for PPE1. The highest protection level was contributed by a mixture of PPA1 type I and II. After preincubation of Anabena cells with 100 µM PPA1–type I/II for 16 h followed by application of 1 mM H2O2 or 50 µM CuSO4 for 5 h, A1-phytoprostane pre-treatment protected 84.2% and 77.5% of the cells from cell death, respectively. Without oxylipins pre-treatment, about 98% of the cells were dead. Surprisingly, preincubation of Anabaena with other oxylipins derived from enzymatic pathway in plants and animals showed also an effect, however, the protection effect was low and ranged from 10 to 30%. In contrast, phytoprostanes did not protect Pseudomonas syringae and Escherichia coli from the toxicity of hydrogen peroxide. However, these bacteria do not synthesize polyunsaturated fatty acids and are therefore devoid of and not exposed to endogenously formed oxidized lipids. 5. Exogenous application of 100 µM PPF1 or 1.5 mM H2O2 for 90 min did not activate the expression of isiA in Anabaena. Oxylipins also displayed no effect on shinorine and tocopherol levels in Anabaena. However, application of 100 µM PPF1 for 6 h altered the protein expression in Anabaena. Most PPF1-modulated proteins are down-regulated and related to photosynthesis. Since oxidative stress only in combination with high light intensity increased lipid peroxidation, down-regulation of photosynthesis after recognition of oxidised lipids (phytoprostanes) may be a survival strategy of Anabaena to avoid damage by peroxidized lipids. 6. Dead plants may be the main source of (exogenous) phytoprostanes in the natural environment of Anabaena. Dry hay releases PPE1 and PPF1 (11 µg/g DW) into an aqueous environment. Anabaena is the typical cyanobacterium in paddy rice fields. After harvesting, most of uneconomical parts of rice plants are abundant on the field, which may release phytoprostanes that in turn might have an impact on cyanobacteria in the rice ecosystems. However, field research is needed to clarify this suspection. 7. A new class of oxylipins, phytoprostanes type III and IV, was identified and quantified in vitro. The two main phytoprostanes, PPE1 and PPF1 (type III and IV), can be obtained by autoxidation of -linolenic acid or Borage oil (containing 25% esterified -linolenic acid). After 12 days of autoxidation and subsequent hydrolysis, 1 g of Borage oil yielded 112.71 ± 1.93 µg of PPF1 and 3.80 ± 0.14 mg of PPE1. PPB1 and PPA1 (type III and IV) were prepared by isomerization and dehydration of PPE1 (type III and IV). The overall yield of PPB1 was 1.71 ± 0.04 mg/g oil (type III) and 2.09 ± 0.12 mg/g oil (type IV). Those of PPA1 were 8.38 ± 0.35 µg/g and 10.18 ± 0.30 µg/oil, respectively. 8. A rapid HPLC-MS/MS method for phytoprostane and phytohormone analysis has been developed. This method was applied to quantify free and esterified E1- and F1-phytoprostanes type III and IV in Synechocystis PCC 6803. The in vivo phytoprostanes type III and IV are present both in free and esterified form. The total cellular level of PPE1 type III and IV in Synechocystis is at least 2 times higher than that of PPF1. Unlike Anabaena, PPE1 and PPF1 were detectable in the medium of one week old Synechocystis cultures. Free levels of PPF1 in the medium (231.8 ± 36.2 ng/l) and in the cells (164.9 ± 15.2 ng/g DW) are lower than those of PPE1 (1003.3 ± 365.2 ng/l and 2331.0 ± 87.7 ng/g DW). KW - Oxidativer Stress KW - oxidative stress KW - phytoprostane KW - oxidized lipids Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-24347 ER -