@article{GrotemeyerMcFlederWuetal.2022, author = {Grotemeyer, Alexander and McFleder, Rhonda Leah and Wu, Jingjing and Wischhusen, J{\"o}rg and Ip, Chi Wang}, title = {Neuroinflammation in Parkinson's disease - putative pathomechanisms and targets for disease-modification}, series = {Frontiers in Immunology}, volume = {13}, journal = {Frontiers in Immunology}, issn = {1664-3224}, doi = {10.3389/fimmu.2022.878771}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-274665}, year = {2022}, abstract = {Parkinson's disease (PD) is a progressive and debilitating chronic disease that affects more than six million people worldwide, with rising prevalence. The hallmarks of PD are motor deficits, the spreading of pathological α-synuclein clusters in the central nervous system, and neuroinflammatory processes. PD is treated symptomatically, as no causally-acting drug or procedure has been successfully established for clinical use. Various pathways contributing to dopaminergic neuron loss in PD have been investigated and described to interact with the innate and adaptive immune system. We discuss the possible contribution of interconnected pathways related to the immune response, focusing on the pathophysiology and neurodegeneration of PD. In addition, we provide an overview of clinical trials targeting neuroinflammation in PD.}, language = {en} } @article{KarikariMcFlederRibechinietal.2022, author = {Karikari, Akua A. and McFleder, Rhonda L. and Ribechini, Eliana and Blum, Robert and Bruttel, Valentin and Knorr, Susanne and Gehmeyr, Mona and Volkmann, Jens and Brotchie, Jonathan M. and Ahsan, Fadhil and Haack, Beatrice and Monoranu, Camelia-Maria and Keber, Ursula and Yeghiazaryan, Rima and Pagenstecher, Axel and Heckel, Tobias and Bischler, Thorsten and Wischhusen, J{\"o}rg and Koprich, James B. and Lutz, Manfred B. and Ip, Chi Wang}, title = {Neurodegeneration by α-synuclein-specific T cells in AAV-A53T-α-synuclein Parkinson's disease mice}, series = {Brain, Behavior, and Immunity}, volume = {101}, journal = {Brain, Behavior, and Immunity}, doi = {10.1016/j.bbi.2022.01.007}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300600}, pages = {194 -- 210}, year = {2022}, abstract = {Background Antigen-specific neuroinflammation and neurodegeneration are characteristic for neuroimmunological diseases. In Parkinson's disease (PD) pathogenesis, α-synuclein is a known culprit. Evidence for α-synuclein-specific T cell responses was recently obtained in PD. Still, a causative link between these α-synuclein responses and dopaminergic neurodegeneration had been lacking. We thus addressed the functional relevance of α-synuclein-specific immune responses in PD in a mouse model. Methods We utilized a mouse model of PD in which an Adeno-associated Vector 1/2 serotype (AAV1/2) expressing human mutated A53T-α-Synuclein was stereotactically injected into the substantia nigra (SN) of either wildtype C57BL/6 or Recombination-activating gene 1 (RAG1)\(^{-/-}\) mice. Brain, spleen, and lymph node tissues from different time points following injection were then analyzed via FACS, cytokine bead assay, immunohistochemistry and RNA-sequencing to determine the role of T cells and inflammation in this model. Bone marrow transfer from either CD4\(^{+}\)/CD8\(^{-}\), CD4\(^{-}\)/CD8\(^{+}\), or CD4\(^{+}\)/CD8\(^{+}\) (JHD\(^{-/-}\)) mice into the RAG-1\(^{-/-}\) mice was also employed. In addition to the in vivo studies, a newly developed A53T-α-synuclein-expressing neuronal cell culture/immune cell assay was utilized. Results AAV-based overexpression of pathogenic human A53T-α-synuclein in dopaminergic neurons of the SN stimulated T cell infiltration. RNA-sequencing of immune cells from PD mouse brains confirmed a pro-inflammatory gene profile. T cell responses were directed against A53T-α-synuclein-peptides in the vicinity of position 53 (68-78) and surrounding the pathogenically relevant S129 (120-134). T cells were required for α-synuclein-induced neurodegeneration in vivo and in vitro, while B cell deficiency did not protect from dopaminergic neurodegeneration. Conclusions Using T cell and/or B cell deficient mice and a newly developed A53T-α-synuclein-expressing neuronal cell culture/immune cell assay, we confirmed in vivo and in vitro that pathogenic α-synuclein peptide-specific T cell responses can cause dopaminergic neurodegeneration and thereby contribute to PD-like pathology.}, language = {en} } @article{GrotemeyerFischerKoprichetal.2023, author = {Grotemeyer, Alexander and Fischer, Judith F. and Koprich, James B. and Brotchie, Jonathan M. and Blum, Robert and Volkmann, Jens and Ip, Chi Wang}, title = {Inflammasome inhibition protects dopaminergic neurons from α-synuclein pathology in a model of progressive Parkinson's disease}, series = {Journal of Neuroinflammation}, volume = {20}, journal = {Journal of Neuroinflammation}, doi = {10.1186/s12974-023-02759-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-357652}, year = {2023}, abstract = {Neuroinflammation has been suggested as a pathogenetic mechanism contributing to Parkinson's disease (PD). However, anti-inflammatory treatment strategies have not yet been established as a therapeutic option for PD patients. We have used a human α-synuclein mouse model of progressive PD to examine the anti-inflammatory and neuroprotective effects of inflammasome inhibition on dopaminergic (DA) neurons in the substantia nigra (SN). As the NLRP3 (NOD-, LRR- and pyrin domain-containing 3)-inflammasome is a core interface for both adaptive and innate inflammation and is also highly druggable, we investigated the implications of its inhibition. Repeat administration of MCC950, an inhibitor of NLRP3, in a PD model with ongoing pathology reduced CD4\(^+\) and CD8\(^+\) T cell infiltration into the SN. Furthermore, the anti-inflammasome treatment mitigated microglial activation and modified the aggregation of α-synuclein protein in DA neurons. MCC950-treated mice showed significantly less neurodegeneration of DA neurons and a reduction in PD-related motor behavior. In summary, early inflammasome inhibition can reduce neuroinflammation and prevent DA cell death in an α-synuclein mouse model for progressive PD.}, language = {en} } @article{RauschenbergerBehnkeGrotemeyeretal.2022, author = {Rauschenberger, Lisa and Behnke, Jennifer and Grotemeyer, Alexander and Knorr, Susanne and Volkmann, Jens and Ip, Chi Wang}, title = {Age-dependent neurodegeneration and neuroinflammation in a genetic A30P/A53T double-mutated α-synuclein mouse model of Parkinson's disease}, series = {Neurobiology of Disease}, volume = {171}, journal = {Neurobiology of Disease}, doi = {10.1016/j.nbd.2022.105798}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300629}, year = {2022}, abstract = {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.}, language = {en} }