TY - JOUR A1 - Wulf, Maximilian A1 - Barkovits, Katalin A1 - Schork, Karin A1 - Eisenacher, Martin A1 - Riederer, Peter A1 - Gerlach, Manfred A1 - Eggers, Britta A1 - Marcus, Katrin T1 - The proteome of neuromelanin granules in dementia with Lewy bodies JF - Cells N2 - Neuromelanin granules (NMGs) are organelle-like structures present in the human substantia nigra pars compacta. In addition to neuromelanin, NMGs contain proteins, lipids and metals. As NMG-containing dopaminergic neurons are preferentially lost in Parkinson’s disease and dementia with Lewy bodies (DLB), it is assumed that NMGs may play a role in neurodegenerative processes. Until now, this role is not completely understood and needs further investigation. We therefore set up an exploratory proteomic study to identify differences in the proteomic profile of NMGs from DLB patients (n = 5) compared to healthy controls (CTRL, n = 5). We applied a laser microdissection and mass-spectrometry-based approach, in which we used targeted mass spectrometric experiments for validation. In NMG-surrounding (SN\(_{Surr.}\)) tissue of DLB patients, we found evidence for ongoing oxidative damage and an impairment of protein degradation. As a potentially disease-related mechanism, we found α-synuclein and protein S100A9 to be enriched in NMGs of DLB cases, while the abundance of several ribosomal proteins was significantly decreased. As S100A9 is known to be able to enhance the formation of toxic α-synuclein fibrils, this finding points towards an involvement of NMGs in pathogenesis, however the exact role of NMGs as either neuroprotective or neurotoxic needs to be further investigated. Nevertheless, our study provides evidence for an impairment of protein degradation, ongoing oxidative damage and accumulation of potentially neurotoxic protein aggregates to be central mechanisms of neurodegeneration in DLB. KW - neuromelanin granules KW - neurodegeneration KW - dementia with Lewy bodies KW - proteomics KW - stress granules KW - substantia nigra pars compacta Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-297465 SN - 2073-4409 VL - 11 IS - 22 ER - TY - JOUR A1 - Plum, Sarah A1 - Eggers, Britta A1 - Helling, Stefan A1 - Stepath, Markus A1 - Theiss, Carsten A1 - Leite, Renata E. P. A1 - Molina, Mariana A1 - Grinberg, Lea T. A1 - Riederer, Peter A1 - Gerlach, Manfred A1 - May, Caroline A1 - Marcus, Katrin T1 - Proteomic characterization of synaptosomes from human substantia nigra indicates altered mitochondrial translation in Parkinson's disease JF - Cells N2 - The pathological hallmark of Parkinson's disease (PD) is the loss of neuromelanin-containing dopaminergic neurons within the substantia nigra pars compacta (SNpc). Additionally, numerous studies indicate an altered synaptic function during disease progression. To gain new insights into the molecular processes underlying the alteration of synaptic function in PD, a proteomic study was performed. Therefore, synaptosomes were isolated by density gradient centrifugation from SNpc tissue of individuals at advanced PD stages (N = 5) as well as control subjects free of pathology (N = 5) followed by mass spectrometry-based analysis. In total, 362 proteins were identified and assigned to the synaptosomal core proteome. This core proteome comprised all proteins expressed within the synapses without regard to data analysis software, gender, age, or disease. The differential analysis between control subjects and PD cases revealed that CD9 antigen was overrepresented and fourteen proteins, among them Thymidine kinase 2 (TK2), mitochondrial, 39S ribosomal protein L37, neurolysin, and Methionine-tRNA ligase (MARS2) were underrepresented in PD suggesting an alteration in mitochondrial translation within synaptosomes. KW - synaptosomes KW - proteomics KW - Parkinson's disease KW - substantia nigra pars compacta KW - mitochondrial pathology KW - mitochondrial translation Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-219978 SN - 2073-4409 VL - 9 IS - 12 ER -