The role of damaged mitochondrial DNA in Parkinson Disease

ABSTRACT: Parkinson disease (PD) is a neurodegenerative disease believed to initiate in the brainstem and then spread throughout the brain. The mechanism by which this occurs is not yet fully understood, but here we show that damaged mitochondrial DNA (mtDNA) plays an important role in this process, which can be initiated by dysregulation of the IFNb/IFNAR signalling pathway. We report that lack of neuronal IFNb/IFNAR, which is associated to the development of PD, causes oxidization, mutation, and deletion in mtDNA. Damaged mtDNA is subsequently extruded extracellularly and can induce PD symptoms like motor and cognitive impairments in healthy mouse brains. It even leads to neurodegeneration in brain regions far from the injection site, suggesting that damaged mtDNA triggers the propagation of PD hallmarks through the brain. We further show that the mechanism by which damaged mtDNA causes pathology in healthy neurons is independent of cGAS and IFNb/IFNAR, but it is mediated by activation of dual Toll-like receptor (TLR)4/9 pathways. Through a proteomic analysis of extracellular vesicles containing the damaged mtDNA, we identified the TLR4 activator Ribosomal Protein S3 (Rps3) and established that Rps3 is a key effector protein involved in damaged mtDNA extrusion and recognition. Collectively, these results reveal a new molecular pathway by which damaged mtDNA can initiate and propagate Parkinson's Disease, paving the way for potential new therapies or disease monitoring.

INSTRUMENT(S): Orbitrap Fusion

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Brain

SUBMITTER: Erwin Schoof  

LAB HEAD: Shohreh Issazadeh-Navikas

PROVIDER: PXD038362 | Pride | 2023-09-18

REPOSITORIES: pride