Research Projects

Rationale: Parkinson’s Disease (PD) is the second most prevalent neurodegenerative disorder characterized by the progressive loss of dopaminergic neurons. Postmortem brain and CSF show chronic neuroinflammation however its regulation in brain is not well understood. Both familial and sporadic PD show mitochondrial dysfunction leading to neuronal degeneration. Recent evidence suggest that mitochondrial dysfunction is associated with release of mitochondrial DNA and double-stranded RNA which act as Damage Associated Molecular Patterns (mtDAMPs) and trigger inflammatory cascades in PD. Emerging evidence suggests that E3 ubiquitin ligases, especially the TRIM-NHL subfamily plays a crucial role in mitochondrial homeostasis and can act as sensors of mitochondrial DNA/dsRNA hence regulators of inflammation. However, their specific role in regulating mtDAMPs release and NF-κB/interferon pathway activation in PD remains poorly understood. Hypothesis: We hypothesize that PD stress induces mitochondrial dysfunction and release of mtDAMPs, which can activate NF-κB/IFN inflammatory pathways and chronic activation leads to neuronal cell death. TRIM-NHL proteins, localize on mitochondria and regulate mitochondrial integrity and act as sensor for released DAMPs during stress conditions which recruit mitochondrial adaptor proteins MAVS/STING to activate chronic inflammation leading to enhanced progression of PD. Objectives: The current project plans to investigate the role of TRIM-NHL proteins in regulating mitochondrial integrity, release of mitochondrial DAMPs, inflammation in PD stress conditions. The role of identified proteins will be analyzed in regulation recruitment of mitochondrial adaptor mediated (MAVS/STING) mediated inflammatory pathway and neuronal/glial cell death thereby understanding its implications in PD pathogenesis and develop TRIM-NHL RNA based targeted therapeutics. Main experiments in the proposed study: 1.Analysis of release of mitochondrial DAMPs and activation of NF-κB/IFN pathway during PD stress condition regulating neuronal cell death in dopaminergic neurons. Human iPSC derived dopaminergic neurons and glial cells PD and cell model SH-SY5Y(neuronal) and CHME3(microglial) and will be exposed to rotenone (mitochondrial complex I inhibitor) and TNF-α(induce inflammation). The release of mtDAMPs and activation of NF-kB/IFN will be monitored. 2.Exploring the role of TRIM-NHL proteins in regulation of NF-κB/IFN pathway and its role in neuronal death. The expression and turnover of TRIM-NHL proteins will be checked under PD stress using proteasome and autophagy pathway inhibitors to understand their degradation dynamics. TRIMs will be over expressed and knockdown in cellular model system as described above regulation of NF-kB and IFN pathway as described above. 3.Studying the potential of STING/MAVS in inhibiting inflammation and mitochondrial dysfunction as a therapeutic strategy Functional studies will involve overexpression and knockdown of TRIM-NHL proteins through shRNA or DNA based transfection, followed by analysis of their regulatory roles in inflammatory signaling and mitochondrial quality control. Pharmacological inhibitors of the STING/MAVS pathway and UPS modulators will be used in combination with and transfection of identified TRIM-NHL and monitoring inflammation and cell death to assess their therapeutic potential in mitigating inflammation induced neuronal damage and restoring mitochondrial functions. Significance of the project: 1.Provide a mechanistic understanding of mitochondria mediated inflammation in regulating neuronal cell death in PD. 2.Establish TRIM-NHL proteins as novel regulators of mitochondrial quality control and innate immune activation. 3.Possible development of combinatorial therapeutic regimen of MAVS/SITNG antagonist to modulate neuroinflammation. 4.Identify potential therapeutic strategies targeting TRIM stability and STING/MAVS signaling to mitigate PD pathogenesis.