PROTEOMIC ANALYSIS OF ANANDAMIDE-INDUCED APOPTOSIS IN HUMAN NEURONAL CELLS

Introduction: Anandamide (AEA) is an endogenous agonist of type 1 cannabinoid receptors (CB1R) that, along with the enzymes responsible for the synthesis, transport and hydrolysis of AEA and congeners, compose the “endocannabinoid system (ECS)”. In this study, we report the biochemical, morphological and functional characterization of the ECS in human neuroblastoma SH-SY5Y cells, that are an experimental model for neuronal cell damage and death, as well as for major human neurodegenerative disorders.Methods: SH-SY5Y cells were cultured with AEA in the presence or absence of CB1 antagonist. Activity of FAAH and NAPE-PLD, MAGL, DAGL and cannabinoid receptors were assessed by standard methods. mRNA expression, siRNA evaluation, apoptosis analysis and proteomic assays were measured by traditional procedures.Results: We show that AEA induced apoptosis of SH-SY5Y cells via CB1R. Through proteomic analysis, we demonstrate that AEA-induced apoptosis was paralleled by a ~3 to ~5-fold up-regulation or down-regulation of five genes (i.e., BiP/GRP78). Interestingly, only the effect of AEA on BiP was reversed by SR141716, and silencing or over-expression of this gene increased or reduced, respectively, AEA-induced apoptosis of SH-SY5Y cells. In addition, the expression of the BiP-related apoptotic markers was increased by AEA.Conclusion: In conclusion, we show a complete and fully functional ECS in human SH-SY5Y cells, and report an unprecedented proteomic analysis that identifies BiP as a key-protein in the death programme induced by AEA in human neuronal cells[...]