TY - THES A1 - Yuan, Xidi T1 - Aging and inflammation in the peripheral nervous system T1 - Altern und Entzündung im peripheren Nervensystem N2 - Aging is known to be a risk factor for structural abnormalities and functional decline in the nervous system. Characterizing age-related changes is important to identify putative pathways to overcome deleterious effects and improve life quality for the elderly. In this study, the peripheral nervous system of 24-month-old aged C57BL/6 mice has been investigated and compared to 12-month-old adult mice. Aged mice showed pathological alterations in their peripheral nerves similar to nerve biopsies from elderly human individuals, with nerve fibers showing demyelination and axonal damage. Such changes were lacking in nerves of adult 12-month-old mice and adult, non-aged humans. Moreover, neuromuscular junctions of 24-month-old mice showed increased denervation compared to adult mice. These alterations were accompanied by elevated numbers of macrophages in the peripheral nerves of aged mice. The neuroinflammatory conditions were associated with impaired myelin integrity and with a decline of nerve conduction properties and muscle strength in aged mice. To determine the pathological impact of macrophages in the aging mice, macrophage depletion was performed in mice by oral administration of CSF-1R specific kinase (c-FMS) inhibitor PLX5622 (300 mg/kg body weight), which reduced the number of macrophages in the peripheral nerves by 70%. The treated mice showed attenuated demyelination, less muscle denervation and preserved muscle strength. This indicates that macrophage-driven inflammation in the peripheral nerves is partially responsible for the age-related neuropathy in mice. Based on previous observations that systemic inflammation can accelerate disease progression in mouse models of neurodegenerative diseases, it was hypothesized that systemic inflammation can exacerbate the peripheral neuropathy found in aged mice. To investigate this hypothesis, aged C57BL/6 mice were intraperitoneally injected with a single dose of lipopolysaccharide (LPS; 500 μg/kg body weight) to induce systemic inflammation by mimicking bacterial infection, mostly via activation of Toll-like receptors (TLRs). Altered endoneurial macrophage activation, highlighted by Trem2 downregulation, was found in LPS injected aged mice one month after injection. This was accompanied by a so far rarely observed form of axonal perturbation, i.e., the occurrence of “dark axons” characterized by a damaged cytoskeleton and an increased overall electron density of the axoplasm. At the same time, however, LPS injection reduced demyelination and muscle denervation in aged mice. Interestingly, TREM2 deficiency in aged mice led to similar changes to LPS injection. This suggests that LPS injection likely mitigates aging-related demyelination and muscle denervation via Trem2 downregulation. Taken together, this study reveals the role of macrophage-driven inflammation as a pathogenic mediator in age-related peripheral neuropathy, and that targeting macrophages might be an option to mitigate peripheral neuropathies in aging individuals. Furthermore, this study shows that systemic inflammation may be an ambivalent modifier of age-related nerve damage, leading to a distinct type of axonal perturbation, but in addition to functionally counteracting, dampened demyelination and muscle denervation. Translationally, it is plausible to assume that tipping the balance of macrophage polarization to one direction or the other may determine the functional outcome in the aging peripheral nervous system of the elderly. N2 - Es ist bekannt, dass das Altern ein Risikofaktor für strukturelle Veränderungen und Funktionsstörungen des Nervensystems ist. Die Charakterisierung altersbedingter Veränderungen ist wichtig, um mögliche Wege zu identifizieren, um schädliche Auswirkungen zu überwinden und die Lebensqualität älterer Menschen zu verbessern. In dieser Studie wurde das periphere Nervensystem von 24 Monate alten gealterten C57BL/6-Mäusen untersucht und mit 12 Monate alten adulten Mäusen verglichen. Gealterte Mäuse zeigten ähnliche pathologische Veränderungen in ihren peripheren Nerven wie Nervenbiopsien älterer Menschen, wobei die Nervenfasern eine Demyelinisierung und axonale Schädigung zeigten. Bei den Nerven von adulten 12 Monate alten Mäusen und nicht gealterten Menschen fehlten solche Veränderungen. Darüber hinaus wiesen die neuromuskulären Endplatten von 24 Monate alten Mäusen im Vergleich zu adulten Mäusen eine erhöhte Denervation auf. Diese Veränderungen wurden von einer erhöhten Anzahl von Makrophagen in den peripheren Nerven gealterter Mäuse begleitet. Die neuroinflammatorischen Bedingungen waren mit einer Beeinträchtigung der Myelinintegrität, einer Abnahme der Nervenleitungseigenschaften und der Muskelkraft bei gealterten Mäusen verbunden. Um den pathologischen Einfluss von Makrophagen bei alternden Mäusen zu bestimmen, wurde die Makrophagen-Depletion bei Mäusen durch orale Verabreichung des CSF-1R-spezifischen Kinase-Inhibitors (c-FMS) PLX5622 (300 mg/kg Körpergewicht) durchgeführt, welche die Anzahl der Makrophagen in den peripheren Nerven um 70% reduzierte. Die behandelten Mäuse zeigten eine verminderte Demyelinisierung, eine reduzierte Muskeldenervation und einen Erhalt der Muskelkraft. Dies deutet darauf hin, dass die durch Makrophagen verursachte Entzündung in den peripheren Nerven teilweise für die altersbedingte Neuropathie bei Mäusen verantwortlich ist. Auf der Grundlage früherer Beobachtungen, dass systemische Entzündungen das Fortschreiten der Krankheit in Mausmodellen neurodegenerativer Erkrankungen beschleunigen können, wurde die Hypothese aufgestellt, dass systemische Entzündungen die periphere Neuropathie in gealterten Mäusen verschlimmern können. Um diese Hypothese zu untersuchen, wurde gealterten C57BL/6-Mäusen eine Einzeldosis Lipopolysaccharid (LPS; 500 μg/kg Körpergewicht) intraperitonal injiziert, um eine systemische Entzündung durch Nachahmung einer bakteriellen Infektion, meist über die Aktivierung von Toll-like-Rezeptoren (TLRs), zu induzieren. Eine veränderte endoneuriale Makrophagenaktivierung, die durch eine reduzierte Trem2-Expression hervorgehoben wird, konnte bei LPS-injizierten gealterten Mäusen einen Monat nach der Injektion gefunden werden. Dies ging einher mit einer bisher selten beobachteten Form der axonalen Perturbation, d.h. dem Auftreten von "dunklen Axonen", die sich durch ein geschädigtes Zytoskelett und eine erhöhte Gesamtelektronendichte des Axoplasmas auszeichnen. Gleichzeitig verringerte die LPS-Injektion jedoch die Demyelinisierung und Muskeldenervation bei gealterten Mäusen. Interessanterweise führte die TREM2 Defizienz bei gealterten Mäusen zu vergleichbaren Veränderungen wie die LPS-Injektion. Dies deutet darauf hin, dass die LPS-Injektion die alterungsbedingte Demyelinisierung und Muskeldenervierung über die Trem2 Herunterregulation abschwächt. Zusammenfassend zeigt diese Studie die Rolle der Makrophagen-getriebenen Entzündung als pathogener Mediator bei der altersbedingten peripheren Neuropathie. Zusätzlich deuten die Ergebnisse darauf hin, dass die gezielte Behandlung von Makrophagen eine Option zur Linderung peripherer Neuropathien bei alternden Menschen sein könnte. Darüber hinaus zeigt diese Studie, dass die systemische Entzündung ein ambivalenter Modifikator der altersbedingten Nervenschädigung sein kann, der zu einer bestimmten Art von axonaler Perturbation führt, aber zusätzlich zu einer funktionell entgegenwirkenden, weniger schweren Demyelinisierung und Muskeldenervation. Translatorisch ist es plausibel anzunehmen, dass eine Veränderung des Gleichgewichts der Makrophagenpolarisation in die eine oder andere Richtung das funktionelle Ergebnis im alternden peripheren Nervensystem der älteren Menschen bestimmen kann. KW - Maus KW - Peripheres Nervensystem KW - Altern KW - Immunsystem KW - macrophages KW - peripheral nervous system KW - aging KW - neuroinflammation KW - Trem2 KW - systemic inflammation Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-237378 ER - TY - JOUR A1 - Weise, Gesa A1 - Stoll, Guido T1 - Magnetic resonance imaging of blood brain/nerve barrier dysfunction and leukocyte infiltration: closely related or discordant? JF - Frontiers in Neurology N2 - Unlike other organs the nervous system is secluded from the rest of the organism by the blood brain barrier (BBB) or blood nerve barrier (BNB) preventing passive influx of fluids from the circulation. Similarly, leukocyte entry to the nervous system is tightly controlled. Breakdown of these barriers and cellular inflammation are hallmarks of inflammatory as well as ischemic neurological diseases and thus represent potential therapeutic targets. The spatiotemporal relationship between BBB/BNB disruption and leukocyte infiltration has been a matter of debate. We here review contrast-enhanced magnetic resonance imaging (MRI) as a non-invasive tool to depict barrier dysfunction and its relation to macrophage infiltration in the central and peripheral nervous system under pathological conditions. Novel experimental contrast agents like Gadofluorine M (Gf) allow more sensitive assessment of BBB dysfunction than conventional Gadolinium (Gd)-DTPA enhanced MRI. In addition, Gf facilitates visualization of functional and transient alterations of the BBB remote from lesions. Cellular contrast agents such as superparamagnetic iron oxide particles (SPIO) and perfluorocarbons enable assessment of leukocyte (mainly macrophage) infiltration by MR technology. Combined use of these MR contrast agents disclosed that leukocytes can enter the nervous system independent from a disturbance of the BBB, and vice versa, a dysfunctional BBB/BNB by itself is not sufficient to attract inflammatory cells from the circulation. We will illustrate these basic imaging findings in animal models of multiple sclerosis, cerebral ischemia, and traumatic nerve injury and review corresponding findings in patients. KW - contrast-enhanced MRI KW - neuroinflammation KW - gadolinium-DTPA KW - gadofluorine KW - iron oxide nanoparticles KW - blood brain barrier Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-123359 VL - 3 IS - 178 ER - TY - JOUR A1 - Traub, Jan A1 - Frey, Anna A1 - Störk, Stefan T1 - Chronic neuroinflammation and cognitive decline in patients with cardiac disease: evidence, relevance, and therapeutic implications JF - Life N2 - Acute and chronic cardiac disorders predispose to alterations in cognitive performance, ranging from mild cognitive impairment to overt dementia. Although this association is well-established, the factors inducing and accelerating cognitive decline beyond ageing and the intricate causal pathways and multilateral interdependencies involved remain poorly understood. Dysregulated and persistent inflammatory processes have been implicated as potentially causal mediators of the adverse consequences on brain function in patients with cardiac disease. Recent advances in positron emission tomography disclosed an enhanced level of neuroinflammation of cortical and subcortical brain regions as an important correlate of altered cognition in these patients. In preclinical and clinical investigations, the thereby involved domains and cell types of the brain are gradually better characterized. Microglia, resident myeloid cells of the central nervous system, appear to be of particular importance, as they are extremely sensitive to even subtle pathological alterations affecting their complex interplay with neighboring astrocytes, oligodendrocytes, infiltrating myeloid cells, and lymphocytes. Here, we review the current evidence linking cognitive impairment and chronic neuroinflammation in patients with various selected cardiac disorders including the aspect of chronic neuroinflammation as a potentially druggable target. KW - neuroinflammation KW - cognitive impairment KW - dementia KW - myocardial infarction KW - heart failure KW - hypertension KW - coronary artery disease KW - atrial fibrillation KW - cardiac arrest KW - aortic valve stenosis Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-304869 SN - 2075-1729 VL - 13 IS - 2 ER - TY - JOUR A1 - Silwedel, Christine A1 - Speer, Christian P. A1 - Haarmann, Axel A1 - Fehrholz, Markus A1 - Claus, Heike A1 - Schlegel, Nicolas A1 - Glaser, Kirsten T1 - Ureaplasma species modulate cytokine and chemokine responses in human brain microvascular endothelial cells JF - International Journal of Molecular Science N2 - Ureaplasma species are common colonizers of the adult genitourinary tract and often considered as low-virulence commensals. Intraamniotic Ureaplasma infections, however, facilitate chorioamnionitis and preterm birth, and cases of Ureaplasma-induced neonatal sepsis, pneumonia, and meningitis raise a growing awareness of their clinical relevance. In vitro studies are scarce but demonstrate distinct Ureaplasma-driven impacts on immune mechanisms. The current study addressed cytokine and chemokine responses upon exposure of native or lipopolysaccharide (LPS) co-stimulated human brain microvascular endothelial cells (HBMEC) to Ureaplasma urealyticum or U. parvum, using qRT-PCR, RNA sequencing, multi-analyte immunoassay, and flow cytometry. Ureaplasma exposure in native HBMEC reduced monocyte chemoattractant protein (MCP)-3 mRNA expression (p < 0.01, vs. broth). In co-stimulated HBMEC, Ureaplasma spp. attenuated LPS-evoked mRNA responses for C-X-C chemokine ligand 5, MCP-1, and MCP-3 (p < 0.05, vs. LPS) and mitigated LPS-driven interleukin (IL)-1α protein secretion, as well as IL-8 mRNA and protein responses (p < 0.05). Furthermore, Ureaplasma isolates increased C-X-C chemokine receptor 4 mRNA levels in native and LPS co-stimulated HBMEC (p < 0.05). The presented results may imply immunomodulatory capacities of Ureaplasma spp. which may ultimately promote chronic colonization and long-term neuroinflammation. KW - Ureaplasma urealyticum KW - Ureaplasma parvum KW - neuroinflammation KW - meningitis KW - blood–brain barrier KW - HBMEC Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-201848 SN - 1422-0067 VL - 20 IS - 14 ER - TY - JOUR A1 - Silwedel, Christine A1 - Speer, Christian P. A1 - Haarmann, Axel A1 - Fehrholz, Markus A1 - Claus, Heike A1 - Buttmann, Mathias A1 - Glaser, Kirsten T1 - Novel insights into neuroinflammation: bacterial lipopolysaccharide, tumor necrosis factor α, and Ureaplasma species differentially modulate atypical chemokine receptor 3 responses in human brain microvascular endothelial cells JF - Journal of Neuroinflammation N2 - Background: Atypical chemokine receptor 3 (ACKR3, synonym CXCR7) is increasingly considered relevant in neuroinflammatory conditions, in which its upregulation contributes to compromised endothelial barrier function and may ultimately allow inflammatory brain injury. While an impact of ACKR3 has been recognized in several neurological autoimmune diseases, neuroinflammation may also result from infectious agents, including Ureaplasma species (spp.). Although commonly regarded as commensals of the adult urogenital tract, Ureaplasma spp. may cause invasive infections in immunocompromised adults as well as in neonates and appear to be relevant pathogens in neonatal meningitis. Nonetheless, clinical and in vitro data on Ureaplasma-induced inflammation are scarce. Methods: We established a cell culture model of Ureaplasma meningitis, aiming to analyze ACKR3 variances as a possible pathomechanism in Ureaplasma-associated neuroinflammation. Non-immortalized human brain microvascular endothelial cells (HBMEC) were exposed to bacterial lipopolysaccharide (LPS) or tumor necrosis factor-α (TNF-α), and native as well as LPS-primed HBMEC were cultured with Ureaplasma urealyticum serovar 8 (Uu8) and U. parvum serovar 3 (Up3). ACKR3 responses were assessed via qRT-PCR, RNA sequencing, flow cytometry, and immunocytochemistry. Results: LPS, TNF-α, and Ureaplasma spp. influenced ACKR3 expression in HBMEC. LPS and TNF-α significantly induced ACKR3 mRNA expression (p < 0.001, vs. control), whereas Ureaplasma spp. enhanced ACKR3 protein expression in HBMEC (p < 0.01, vs. broth control). Co-stimulation with LPS and either Ureaplasma isolate intensified ACKR3 responses (p < 0.05, vs. LPS). Furthermore, stimulation wielded a differential influence on the receptor’s ligands. Conclusions: We introduce an in vitro model of Ureaplasma meningitis. We are able to demonstrate a pro-inflammatory capacity of Ureaplasma spp. in native and, even more so, in LPS-primed HBMEC, underlining their clinical relevance particularly in a setting of co-infection. Furthermore, our data may indicate a novel role for ACKR3, with an impact not limited to auto-inflammatory diseases, but extending to infection-related neuroinflammation as well. AKCR3-induced blood-brain barrier breakdown might constitute a potential common pathomechanism. KW - atypical chemokine receptor 3 KW - human brain microvascular endothelial cells KW - meningitis KW - neuroinflammation KW - Ureaplasma species Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-175952 VL - 15 IS - 156 ER - TY - JOUR A1 - Sian-Hulsmann, Jeswinder A1 - Riederer, Peter T1 - The nigral coup in Parkinson's Disease by α-synuclein and its associated rebels JF - Cells N2 - The risk of Parkinson's disease increases with age. However, the etiology of the illness remains obscure. It appears highly likely that the neurodegenerative processes involve an array of elements that influence each other. In addition, genetic, endogenous, or exogenous toxins need to be considered as viable partners to the cellular degeneration. There is compelling evidence that indicate the key involvement of modified α-synuclein (Lewy bodies) at the very core of the pathogenesis of the disease. The accumulation of misfolded α-synuclein may be a consequence of some genetic defect or/and a failure of the protein clearance system. Importantly, α-synuclein pathology appears to be a common denominator for many cellular deleterious events such as oxidative stress, mitochondrial dysfunction, dopamine synaptic dysregulation, iron dyshomeostasis, and neuroinflammation. These factors probably employ a common apoptotic/or autophagic route in the final stages to execute cell death. The misfolded α-synuclein inclusions skillfully trigger or navigate these processes and thus amplify the dopamine neuron fatalities. Although the process of neuroinflammation may represent a secondary event, nevertheless, it executes a fundamental role in neurodegeneration. Some viral infections produce parkinsonism and exhibit similar characteristic neuropathological changes such as a modest brain dopamine deficit and α-synuclein pathology. Thus, viral infections may heighten the risk of developing PD. Alternatively, α-synuclein pathology may induce a dysfunctional immune system. Thus, sporadic Parkinson's disease is caused by multifactorial trigger factors and metabolic disturbances, which need to be considered for the development of potential drugs in the disorder. KW - Parkinson's disease KW - substantia nigra KW - alpha-synuclein KW - genetics KW - iron KW - neuroinflammation KW - viruses KW - immunology KW - aging and cell death Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-234073 SN - 2073-4409 VL - 10 IS - 3 ER - TY - JOUR A1 - Schuhmann, Michael K. A1 - Stoll, Guido A1 - Bohr, Arne A1 - Volkmann, Jens A1 - Fluri, Felix T1 - Electrical stimulation of the mesencephalic locomotor region attenuates neuronal loss and cytokine expression in the perifocal region of photothrombotic stroke in rats JF - International Journal of Molecular Science N2 - Deep brain stimulation of the mesencephalic locomotor region (MLR) improves the motor symptoms in Parkinson’s disease and experimental stroke by intervening in the motor cerebral network. Whether high-frequency stimulation (HFS) of the MLR is involved in non-motor processes, such as neuroprotection and inflammation in the area surrounding the photothrombotic lesion, has not been elucidated. This study evaluates whether MLR-HFS exerts an anti-apoptotic and anti-inflammatory effect on the border zone of cerebral photothrombotic stroke. Rats underwent photothrombotic stroke of the right sensorimotor cortex and the implantation of a microelectrode into the ipsilesional MLR. After intervention, either HFS or sham stimulation of the MLR was applied for 24 h. The infarct volumes were calculated from consecutive brain sections. Neuronal apoptosis was analyzed by TUNEL staining. Flow cytometry and immunohistochemistry determined the perilesional inflammatory response. Neuronal apoptosis was significantly reduced in the ischemic penumbra after MLR-HFS, whereas the infarct volumes did not differ between the groups. MLR-HFS significantly reduced the release of cytokines and chemokines within the ischemic penumbra. MLR-HFS is neuroprotective and it reduces pro-inflammatory mediators in the area that surrounds the photothrombotic stroke without changing the number of immune cells, which indicates that MLR-HFS enables the function of inflammatory cells to be altered on a molecular level. KW - photothrombotic stroke KW - deep brain stimulation KW - mesencephalic locomotor region KW - neuroprotection KW - neuronal apoptosis KW - neuroinflammation Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-201355 SN - 1422-0067 VL - 20 IS - 9 ER - TY - JOUR A1 - Schuhmann, Michael K. A1 - Papp, Lena A1 - Stoll, Guido A1 - Blum, Robert A1 - Volkmann, Jens A1 - Fluri, Felix T1 - Mesencephalic electrical stimulation reduces neuroinflammation after photothrombotic stroke in rats by targeting the cholinergic anti-inflammatory pathway JF - International Journal of Molecular Sciences N2 - Inflammation is crucial in the pathophysiology of stroke and thus a promising therapeutic target. High-frequency stimulation (HFS) of the mesencephalic locomotor region (MLR) reduces perilesional inflammation after photothrombotic stroke (PTS). However, the underlying mechanism is not completely understood. Since distinct neural and immune cells respond to electrical stimulation by releasing acetylcholine, we hypothesize that HFS might trigger the cholinergic anti-inflammatory pathway via activation of the α7 nicotinic acetylcholine receptor (α7nAchR). To test this hypothesis, rats underwent PTS and implantation of a microelectrode into the MLR. Three hours after intervention, either HFS or sham-stimulation of the MLR was applied for 24 h. IFN-γ, TNF-α, and IL-1α were quantified by cytometric bead array. Choline acetyltransferase (ChAT)\(^+\) CD4\(^+\)-cells and α7nAchR\(^+\)-cells were quantified visually using immunohistochemistry. Phosphorylation of NFĸB, ERK1/2, Akt, and Stat3 was determined by Western blot analyses. IFN-γ, TNF-α, and IL-1α were decreased in the perilesional area of stimulated rats compared to controls. The number of ChAT\(^+\) CD4\(^+\)-cells increased after MLR-HFS, whereas the amount of α7nAchR\(^+\)-cells was similar in both groups. Phospho-ERK1/2 was reduced significantly in stimulated rats. The present study suggests that MLR-HFS may trigger anti-inflammatory processes within the perilesional area by modulating the cholinergic system, probably via activation of the α7nAchR. KW - photothrombotic stroke KW - deep brain stimulation KW - mesencephalic locomotor region KW - neuroinflammation KW - choline acetyltransferase KW - alpha-7 nicotinic acetylcholine receptor Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-259099 SN - 1422-0067 VL - 22 IS - 3 ER - TY - JOUR A1 - Riederer, P. A1 - Monoranu, C. A1 - Strobel, S. A1 - Iordache, T. A1 - Sian-Hülsmann, J. T1 - Iron as the concert master in the pathogenic orchestra playing in sporadic Parkinson's disease JF - Journal of Neural Transmission N2 - About 60 years ago, the discovery of a deficiency of dopamine in the nigro-striatal system led to a variety of symptomatic therapeutic strategies to supplement dopamine and to substantially improve the quality of life of patients with Parkinson's disease (PD). Since these seminal developments, neuropathological, neurochemical, molecular biological and genetic discoveries contributed to elucidate the pathology of PD. Oxidative stress, the consequences of reactive oxidative species, reduced antioxidative capacity including loss of glutathione, excitotoxicity, mitochondrial dysfunction, proteasomal dysfunction, apoptosis, lysosomal dysfunction, autophagy, suggested to be causal for ɑ-synuclein fibril formation and aggregation and contributing to neuroinflammation and neural cell death underlying this devastating disorder. However, there are no final conclusions about the triggered pathological mechanism(s) and the follow-up of pathological dysfunctions. Nevertheless, it is a fact, that iron, a major component of oxidative reactions, as well as neuromelanin, the major intraneuronal chelator of iron, undergo an age-dependent increase. And ageing is a major risk factor for PD. Iron is significantly increased in the substantia nigra pars compacta (SNpc) of PD. Reasons for this finding include disturbances in iron-related import and export mechanisms across the blood-brain barrier (BBB), localized opening of the BBB at the nigro-striatal tract including brain vessel pathology. Whether this pathology is of primary or secondary importance is not known. We assume that there is a better fit to the top-down hypotheses and pathogens entering the brain via the olfactory system, then to the bottom-up (gut-brain) hypothesis of PD pathology. Triggers for the bottom-up, the dual-hit and the top-down pathologies include chemicals, viruses and bacteria. If so, hepcidin, a regulator of iron absorption and its distribution into tissues, is suggested to play a major role in the pathogenesis of iron dyshomeostasis and risk for initiating and progressing ɑ-synuclein pathology. The role of glial components to the pathology of PD is still unknown. However, the dramatic loss of glutathione (GSH), which is mainly synthesized in glia, suggests dysfunction of this process, or GSH uptake into neurons. Loss of GSH and increase in SNpc iron concentration have been suggested to be early, may be even pre-symptomatic processes in the pathology of PD, despite the fact that they are progression factors. The role of glial ferritin isoforms has not been studied so far in detail in human post-mortem brain tissue and a close insight into their role in PD is called upon. In conclusion, "iron" is a major player in the pathology of PD. Selective chelation of excess iron at the site of the substantia nigra, where a dysfunction of the BBB is suggested, with peripherally acting iron chelators is suggested to contribute to the portfolio and therapeutic armamentarium of anti-Parkinson medications. KW - SARS-CoV-2 KW - iron in parkinsonism KW - parkinson’s disease KW - iiron transporter KW - neuromelanin KW - iron pathology KW - neuroinflammation KW - iron model KW - ferroptosis KW - ɑ-Synuclein and iron KW - virus–iron interaction KW - COVID-19 KW - hepcidin Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-268539 SN - 1435-1463 VL - 128 IS - 10 ER - TY - JOUR A1 - Rauschenberger, Lisa A1 - Behnke, Jennifer A1 - Grotemeyer, Alexander A1 - Knorr, Susanne A1 - Volkmann, Jens A1 - Ip, Chi Wang T1 - Age-dependent neurodegeneration and neuroinflammation in a genetic A30P/A53T double-mutated α-synuclein mouse model of Parkinson’s disease JF - Neurobiology of Disease N2 - The pathogenesis of Parkinson's disease (PD) is closely interwoven with the process of aging. Moreover, increasing evidence from human postmortem studies and from animal models for PD point towards inflammation as an additional factor in disease development. We here assessed the impact of aging and inflammation on dopaminergic neurodegeneration in the hm\(^{2}\)α-SYN-39 mouse model of PD that carries the human, A30P/A53T double-mutated α-synuclein gene. At 2–3 months of age, no significant differences were observed comparing dopaminergic neuron numbers of the substantia nigra (SN) pars compacta of hm\(^{2}\)α-SYN-39 mice with wildtype controls. At an age of 16–17 months, however, hm\(^{2}\)α-SYN-39 mice revealed a significant loss of dopaminergic SN neurons, of dopaminergic terminals in the striatum as well as a reduction of striatal dopamine levels compared to young, 2–3 months transgenic mice and compared to 16–17 months old wildtype littermates. A significant age-related correlation of infiltrating CD4+ and CD8\(^{+}\) T cell numbers with dopaminergic terminal loss of the striatum was found in hm\(^{2}\)α-SYN-39 mice, but not in wildtype controls. In the striatum of 16–17 months old wildtype mice a slightly elevated CD8\(^{+}\) T cell count and CD11b\(^{+}\) microglia cell count was observed compared to younger aged mice. Additional analyses of neuroinflammation in the nigrostriatal tract of wildtype mice did not yield any significant age-dependent changes of CD4\(^{+}\), CD8\(^{+}\) T cell and B220\(^{+}\) B cell numbers, respectively. In contrast, a significant age-dependent increase of CD8\(^{+}\) T cells, GFAP\(^{+}\) astrocytes as well as a pronounced increase of CD11b+ microglia numbers were observed in the SN of hm\(^{2}\)α-SYN-39 mice pointing towards a neuroinflammatory processes in this genetic mouse model for PD. The findings in the hm\(^{2}\)α-SYN-39 mouse model strengthen the evidence that T cell and glial cell responses are involved in the age-related neurodegeneration in PD. The slow and age-dependent progression of neurodegeneration and neuroinflammation in the hm\(^{2}\)α-SYN-39 PD rodent model underlines its translational value and makes it suitable for studying anti-inflammatory therapies. KW - Parkinson's disease KW - neuroinflammation KW - neurodegeneration Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-300629 VL - 171 ER -