TY - JOUR A1 - Förster, Carola Y. A1 - Shityakov, Sergey A1 - Scheper, Verena A1 - Lenarz, Thomas T1 - Linking cerebrovascular dysfunction to age-related hearing loss and Alzheimer’s disease — are systemic approaches for diagnosis and therapy required? JF - Biomolecules N2 - Alzheimer’s disease (AD), the most common cause of dementia in the elderly, is a neurodegenerative disorder associated with neurovascular dysfunction, cognitive decline, and the accumulation of amyloid β peptide (Aβ) in the brain and tau-related lesions in neurons termed neurofibrillary tangles (NFTs). Aβ deposits and NFT formation are the central pathological hallmarks in AD brains, and the majority of AD cases have been shown to exhibit a complex combination of systemic comorbidities. While AD is the foremost common cause of dementia in the elderly, age-related hearing loss (ARHL) is the most predominant sensory deficit in the elderly. During aging, chronic inflammation and resulting endothelial dysfunction have been described and might be key contributors to AD; we discuss an intriguing possible link between inner ear strial microvascular pathology and blood–brain barrier pathology and present ARHL as a potentially modifiable and treatable risk factor for AD development. We present compelling evidence that ARHL might well be seen as an important risk factor in AD development: progressive hearing impairment, leading to social isolation, and its comorbidities, such as frailty, falls, and late-onset depression, link ARHL with cognitive decline and increased risk of dementia, rendering it tempting to speculate that ARHL might be a potential common molecular and pathological trigger for AD. Additionally, one could speculate that amyloid-beta might damage the blood–labyrinth barrier as it does to the blood–brain barrier, leading to ARHL pathology. Finally, there are options for the treatment of ARHL by targeted neurotrophic factor supplementation to the cochlea to improve cognitive outcomes; they can also prevent AD development and AD-related comorbidity in the future. KW - Alzheimer’s disease KW - age-related hearing loss KW - neurovasculature KW - blood–brain barrier KW - blood–labyrinth barrier KW - spiral ganglion neuron KW - pharmacotherapy KW - neurotrophic factor KW - inner ear Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-297552 SN - 2218-273X VL - 12 IS - 11 ER - TY - JOUR A1 - Reschke, Moritz A1 - Salvador, Ellaine A1 - Schlegel, Nicolas A1 - Burek, Malgorzata A1 - Karnati, Srikanth A1 - Wunder, Christian A1 - Förster, Carola Y. T1 - Isosteviol sodium (STVNA) reduces pro-inflammatory cytokine IL-6 and GM-CSF in an in vitro murine stroke model of the blood–brain barrier (BBB) JF - Pharmaceutics N2 - Early treatment with glucocorticoids could help reduce both cytotoxic and vasogenic edema, leading to improved clinical outcome after stroke. In our previous study, isosteviol sodium (STVNA) demonstrated neuroprotective effects in an in vitro stroke model, which utilizes oxygen-glucose deprivation (OGD). Herein, we tested the hypothesis that STVNA can activate glucocorticoid receptor (GR) transcriptional activity in brain microvascular endothelial cells (BMECs) as previously published for T cells. STVNA exhibited no effects on transcriptional activation of the glucocorticoid receptor, contrary to previous reports in Jurkat cells. However, similar to dexamethasone, STVNA inhibited inflammatory marker IL-6 as well as granulocyte-macrophage colony-stimulating factor (GM-CSF) secretion. Based on these results, STVNA proves to be beneficial as a possible prevention and treatment modality for brain ischemia-reperfusion injury-induced blood–brain barrier (BBB) dysfunction. KW - IL-6 KW - ischemia KW - isosteviol sodium (STVNA) KW - dexamethasone KW - glucocorticoid receptor KW - cerebEND Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-286275 SN - 1999-4923 VL - 14 IS - 9 ER - TY - JOUR A1 - Thal, Serge C. A1 - Smetak, Manuel A1 - Hayashi, Kentaro A1 - Förster, Carola Y. T1 - Hemorrhagic cerebral insults and secondary Takotsubo syndrome: findings in a novel in vitro model using human blood samples JF - International Journal of Molecular Sciences N2 - Intracranial hemorrhage results in devastating forms of cerebral damage. Frequently, these results also present with cardiac dysfunction ranging from ECG changes to Takotsubo syndrome (TTS). This suggests that intracranial bleeding due to subarachnoid hemorrhage (SAH) disrupts the neuro–cardiac axis leading to neurogenic stress cardiomyopathy (NSC) of different degrees. Following this notion, SAH and secondary TTS could be directly linked, thus contributing to poor outcomes. We set out to test if blood circulation is the driver of the brain–heart axis by investigating serum samples of TTS patients. We present a novel in vitro model combining SAH and secondary TTS to mimic the effects of blood or serum, respectively, on blood–brain barrier (BBB) integrity using in vitro monolayers of an established murine model. We consistently demonstrated decreased monolayer integrity and confirmed reduced Claudin-5 and Occludin levels by RT-qPCR and Western blot and morphological reorganization of actin filaments in endothelial cells. Both tight junction proteins show a time-dependent reduction. Our findings highlight a faster and more prominent disintegration of BBB in the presence of TTS and support the importance of the bloodstream as a causal link between intracerebral bleeding and cardiac dysfunction. This may represent potential targets for future therapeutic inventions in SAH and TTS. KW - Takotsubo syndrome KW - subarachnoid hemorrhage KW - inflammation KW - in vitro KW - blood KW - blood–brain barrier KW - human KW - patient KW - endothelial cells Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-288305 SN - 1422-0067 VL - 23 IS - 19 ER - TY - JOUR A1 - Shityakov, Sergey A1 - Nagai, Michiaki A1 - Ergün, Süleyman A1 - Braunger, Barbara M. A1 - Förster, Carola Y. T1 - The protective effects of neurotrophins and microRNA in diabetic retinopathy, nephropathy and heart failure via regulating endothelial function JF - Biomolecules N2 - Diabetes mellitus is a common disease affecting more than 537 million adults worldwide. The microvascular complications that occur during the course of the disease are widespread and affect a variety of organ systems in the body. Diabetic retinopathy is one of the most common long-term complications, which include, amongst others, endothelial dysfunction, and thus, alterations in the blood-retinal barrier (BRB). This particularly restrictive physiological barrier is important for maintaining the neuroretina as a privileged site in the body by controlling the inflow and outflow of fluid, nutrients, metabolic end products, ions, and proteins. In addition, people with diabetic retinopathy (DR) have been shown to be at increased risk for systemic vascular complications, including subclinical and clinical stroke, coronary heart disease, heart failure, and nephropathy. DR is, therefore, considered an independent predictor of heart failure. In the present review, the effects of diabetes on the retina, heart, and kidneys are described. In addition, a putative common microRNA signature in diabetic retinopathy, nephropathy, and heart failure is discussed, which may be used in the future as a biomarker to better monitor disease progression. Finally, the use of miRNA, targeted neurotrophin delivery, and nanoparticles as novel therapeutic strategies is highlighted. KW - diabetic retinopathy KW - diabetes mellitus KW - microvascular complications KW - diabetic nephropathy KW - heart failure KW - microRNA KW - neurotrophins Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-285966 SN - 2218-273X VL - 12 IS - 8 ER - TY - JOUR A1 - Salvador, Ellaine A1 - Kessler, Almuth F. A1 - Domröse, Dominik A1 - Hörmann, Julia A1 - Schaeffer, Clara A1 - Giniunaite, Aiste A1 - Burek, Malgorzata A1 - Tempel-Brami, Catherine A1 - Voloshin, Tali A1 - Volodin, Alexandra A1 - Zeidan, Adel A1 - Giladi, Moshe A1 - Ernestus, Ralf-Ingo A1 - Löhr, Mario A1 - Förster, Carola Y. A1 - Hagemann, Carsten T1 - Tumor Treating Fields (TTFields) reversibly permeabilize the blood–brain barrier in vitro and in vivo JF - Biomolecules N2 - Despite the availability of numerous therapeutic substances that could potentially target CNS disorders, an inability of these agents to cross the restrictive blood–brain barrier (BBB) limits their clinical utility. Novel strategies to overcome the BBB are therefore needed to improve drug delivery. We report, for the first time, how Tumor Treating Fields (TTFields), approved for glioblastoma (GBM), affect the BBB’s integrity and permeability. Here, we treated murine microvascular cerebellar endothelial cells (cerebEND) with 100–300 kHz TTFields for up to 72 h and analyzed the expression of barrier proteins by immunofluorescence staining and Western blot. In vivo, compounds normally unable to cross the BBB were traced in healthy rat brain following TTFields administration at 100 kHz. The effects were analyzed via MRI and immunohistochemical staining of tight-junction proteins. Furthermore, GBM tumor-bearing rats were treated with paclitaxel (PTX), a chemotherapeutic normally restricted by the BBB combined with TTFields at 100 kHz. The tumor volume was reduced with TTFields plus PTX, relative to either treatment alone. In vitro, we demonstrate that TTFields transiently disrupted BBB function at 100 kHz through a Rho kinase-mediated tight junction claudin-5 phosphorylation pathway. Altogether, if translated into clinical use, TTFields could represent a novel CNS drug delivery strategy. KW - blood–brain barrier KW - TTFields KW - CNS disorders Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-288057 SN - 2218-273X VL - 12 IS - 10 ER - TY - JOUR A1 - Karnati, Srikanth A1 - Guntas, Gulcan A1 - Rajendran, Ranjithkumar A1 - Shityakov, Sergey A1 - Höring, Marcus A1 - Liebisch, Gerhard A1 - Kosanovic, Djuro A1 - Ergün, Süleyman A1 - Nagai, Michiaki A1 - Förster, Carola Y. T1 - Quantitative lipidomic analysis of Takotsubo syndrome patients' serum JF - Frontiers in Cardiovascular Medicine N2 - Takotsubo syndrome (TTS), also known as the transient left ventricular apical ballooning syndrome, is in contemporary times known as novel acute cardiac syndrome. It is characterized by transient left ventricular apical akinesis and hyperkinesis of the basal left ventricular portions. Although the precise etiology of TTS is unknown, events like the sudden release of stress hormones, such as the catecholamines and the increased inflammatory status might be plausible causes leading to the cardiovascular pathologies. Recent studies have highlighted that an imbalance in lipid accumulation might promote a deviant immune response as observed in TTS. However, there is no information on comprehensive profiling of serum lipids of TTS patients. Therefore, we investigated a detailed quantitative lipid analysis of TTS patients using ES-MSI. Our results showed significant differences in the majority of lipid species composition in the TTS patients compared to the control group. Furthermore, the computational analyses presented was able to link the altered lipids to the pro-inflammatory cytokines and disseminate possible mechanistic pathways involving TNFα and IL-6. Taken together, our study provides an extensive quantitative lipidome of TTS patients, which may provide a valuable Pre-diagnostic tool. This would facilitate the elucidation of the underlying mechanisms of the disease and to prevent the development of TTS in the future. KW - TTS KW - inflammation KW - lipids KW - TNF-α KW - IL6 KW - PIK3R1 KW - NF-kappa-B KW - phosphatidylinositol Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-270832 SN - 2297-055X VL - 9 IS - 797154 ER - TY - JOUR A1 - Shityakov, Sergey A1 - Hayashi, Kentaro A1 - Störk, Stefan A1 - Scheper, Verena A1 - Lenarz, Thomas A1 - Förster, Carola Y. T1 - The conspicuous link between ear, brain and heart − Could neurotrophin-treatment of age-related hearing loss help prevent Alzheimer's disease and associated amyloid cardiomyopathy? JF - Biomolecules N2 - Alzheimer's disease (AD), the most common cause of dementia in the elderly, is a neurodegenerative disorder associated with neurovascular dysfunction and cognitive decline. While the deposition of amyloid β peptide (Aβ) and the formation of neurofibrillary tangles (NFTs) are the pathological hallmarks of AD-affected brains, the majority of cases exhibits a combination of comorbidities that ultimately lead to multi-organ failure. Of particular interest, it can be demonstrated that Aβ pathology is present in the hearts of patients with AD, while the formation of NFT in the auditory system can be detected much earlier than the onset of symptoms. Progressive hearing impairment may beget social isolation and accelerate cognitive decline and increase the risk of developing dementia. The current review discusses the concept of a brain–ear–heart axis by which Aβ and NFT inhibition could be achieved through targeted supplementation of neurotrophic factors to the cochlea and the brain. Such amyloid inhibition might also indirectly affect amyloid accumulation in the heart, thus reducing the risk of developing AD-associated amyloid cardiomyopathy and cardiovascular disease. KW - Alzheimer's disease KW - amyloid cardiomyopathy KW - heart failure KW - age-related hearing loss KW - neurotrophins KW - blood–brain barrier KW - blood–labyrinth barrier KW - spiral ganglion neuron KW - BDNF KW - GDNF Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-241084 SN - 2218-273X VL - 11 IS - 6 ER - TY - JOUR A1 - Salvador, Ellaine A1 - Burek, Malgorzata A1 - Löhr, Mario A1 - Nagai, Michiaki A1 - Hagemann, Carsten A1 - Förster, Carola Y. T1 - Senescence and associated blood-brain barrier alterations in vitro JF - Histochemistry and Cell Biology N2 - Progressive deterioration of the central nervous system (CNS) is commonly associated with aging. An important component of the neurovasculature is the blood-brain barrier (BBB), majorly made up of endothelial cells joined together by intercellular junctions. The relationship between senescence and changes in the BBB has not yet been thoroughly explored. Moreover, the lack of in vitro models for the study of the mechanisms involved in those changes impede further and more in-depth investigations in the field. For this reason, we herein present an in vitro model of the senescent BBB and an initial attempt to identify senescence-associated alterations within. KW - senescence KW - in vitro model KW - aging KW - CNS diseases KW - blood–brain barrier Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-267435 SN - 1432-119X VL - 156 IS - 3 ER - TY - JOUR A1 - Shityakov, Sergey A1 - Skorb, Ekaterina V. A1 - Förster, Carola Y. A1 - Dandekar, Thomas T1 - Scaffold Searching of FDA and EMA-Approved Drugs Identifies Lead Candidates for Drug Repurposing in Alzheimer’s Disease JF - Frontiers in Chemistry N2 - Clinical trials of novel therapeutics for Alzheimer’s Disease (AD) have consumed a significant amount of time and resources with largely negative results. Repurposing drugs already approved by the Food and Drug Administration (FDA), European Medicines Agency (EMA), or Worldwide for another indication is a more rapid and less expensive option. Therefore, we apply the scaffold searching approach based on known amyloid-beta (Aβ) inhibitor tramiprosate to screen the DrugCentral database (n = 4,642) of clinically tested drugs. As a result, menadione bisulfite and camphotamide substances with protrombogenic and neurostimulation/cardioprotection effects were identified as promising Aβ inhibitors with an improved binding affinity (ΔGbind) and blood-brain barrier permeation (logBB). Finally, the data was also confirmed by molecular dynamics simulations using implicit solvation, in particular as Molecular Mechanics Generalized Born Surface Area (MM-GBSA) model. Overall, the proposed in silico pipeline can be implemented through the early stage rational drug design to nominate some lead candidates for AD, which will be further validated in vitro and in vivo, and, finally, in a clinical trial. KW - scaffold search KW - approved drugs KW - drug repurposing KW - alzheimer's disease KW - chemical similarity KW - molecular modeling Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-248703 SN - 2296-2646 VL - 9 ER - TY - JOUR A1 - Burek, Malgorzata A1 - Burmester, Sandra A1 - Salvador, Ellaine A1 - Möller-Ehrlich, Kerstin A1 - Schneider, Reinhard A1 - Roewer, Norbert A1 - Nagai, Michiaki A1 - Förster, Carola Y. T1 - Kidney Ischemia/Reperfusion Injury Induces Changes in the Drug Transporter Expression at the Blood–Brain Barrier in vivo and in vitro JF - Frontiers in Physiology N2 - Ischemia/reperfusion injury is a major cause of acute kidney injury (AKI). AKI is characterized by a sudden decrease in kidney function, systemic inflammation, oxidative stress, and dysregulation of the sodium, potassium, and water channels. While AKI leads to uremic encephalopathy, epidemiological studies have shown that AKI is associated with a subsequent risk for developing stroke and dementia. To get more insights into kidney–brain crosstalk, we have created an in vitro co-culture model based on human kidney cells of the proximal tubule (HK-2) and brain microvascular endothelial cells (BMEC). The HK-2 cell line was grown to confluence on 6-well plates and exposed to oxygen/glucose deprivation (OGD) for 4 h. Control HK-2 cells were grown under normal conditions. The BMEC cell line cerebED was grown to confluence on transwells with 0.4 μm pores. The transwell filters seeded and grown to confluence with cereEND were inserted into the plates with HK-2 cells with or without OGD treatment. In addition, cerebEND were left untreated or treated with uremic toxins, indole-3-acetic acid (IAA) and indoxyl sulfate (IS). The protein and mRNA expression of selected BBB-typical influx transporters, efflux transporters, cellular receptors, and tight junction proteins was measured in BMECs. To validate this in vitro model of kidney–brain interaction, we isolated brain capillaries from mice exposed to bilateral renal ischemia (30 min)/reperfusion injury (24 h) and measured mRNA and protein expression as described above. Both in vitro and in vivo systems showed similar changes in the expression of drug transporters, cellular receptors, and tight junction proteins. Efflux pumps, in particular Abcb1b, Abcc1, and Abcg2, have shown increased expression in our model. Thus, our in vitro co-culture system can be used to study the cellular mechanism of kidney and brain crosstalk in renal ischemia/reperfusion injury. KW - kidney ischemia/reperfusion injury KW - brain pathology KW - blood–brain barrier KW - drug transporter KW - tight junctions Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-216413 SN - 1664-042X VL - 11 ER -