Synthesis of mag and lyso ps lipids with varying lipid tails

Abstract

My doctoral research described in this thesis involves the synthesis and characterization of mono acyl glycerol MAG and lysophosphatidylserine lyso PS lipids with varying lipid tails PHARC syndrome is a neurodegenerative disease abbreviated based on its symptoms i e polyneuropathy hearing loss ataxia retinitis pigmentosa and cataract It has been attributed to a mutation in the abhd12 gene which encodes for lysophosphatidylserine lyso PS lipase ABHD12 ABHD12 is an integral membrane enzyme which a member of the serine hydrolase family Mice models for PHARC i e ABHD12 knock out KO mice exhibits locomotor defects microglial activation and accumulation of lyso PS in the cerebellum Biochemical characterization and pathways downstream of lyso PS is unclear in PHARC syndrome The diastereomeric complexity in the lyso PS structure has caused its commercial paucity to study its biological role in detail Hence in this study I have chemically synthesized a library of lyso PSs chain lengths such as medium long and very long chain fatty acyl chains to investigate their role in neuro immunological processes We used these lipids to understand the enzyme kinetics of ABHD12 We found that ABHD12 is highly stereospecific and strongly prefers the R configuration of Me lyso PSs over S analogs Next we used our synthetic Me lyso PS library to investigate the pathways that can be triggered through lyso PS signaling We measured release of calcium cytokines and histamine that were involved in the immune cell activation and phosphorylation pathways in immune cells as a function of lyso PS treatment VLC lyso PS have been found to elicit immune responses in the form of heightened cytokine release via the toll like receptor 2 TLR2 signalling pathway We have also observed that upon LC lyso PS stimulation there is an increase in the cytosolic Ca2 cAMP and phospho ERK levels which we hypothesize might be due to the activation of a yet unknown GPCR This study suggests the intricate balance between LC and VLC lysoPS which influence signi