The role of mitochondria in the dysfunction of oligodendrocyte lineage cells: implications for the pathogenesis of multiple sclerosis. (360G-Wellcome-078415_Z_05_Z)

Objectives: To investigate the role of mitochondria in the dysfunction of oligodendrocyte lineage cells in multiple sclerosis (MS), I will determine the(1) presence of mitochondrial dysfunction at biochemical, protein and genetic levels in oligodendrocyte lineage cells in acute (pattern II and III), active and chronic MS lesions. (2) neuropathological features of inherited mitochondrial disorders with primary demyelination. (3) effects of mitochondrial DNA (mtDNA) abnormalities on the development, function and survival of oligodendrocyte lineage cells in vitro (MO3, HOG, Ntera2 and mouseES cells).Design: (1) Histochemistry and immunohistochemistry will be performed on post-mortem brain tissue from MS and mitochondrial disorders. (2)Molecular biology techniques (laser micro-dissection, real-time PCR and mtDNA sequencing) on dissected oligodendrocyte lineage cells from frozen MS tissue will be used to identify evidence of damaged mtDNA. (3) transmitochondrial hybrids containing inherited abnormal mtDNA and cell lines containing acquiredabnormal mtDNA (IFN-gamma and TNF induced) will be used in vitro to assess migration, proliferation, differentiation, myelination and survival using time-lapse microscopy, proliferation markers, electron microscopy for ultrastructure, immunocytochemistry for myelin proteins and apoptosis using flow cytometry.