Peridroplet mitochondria regulated by perilipin 5 are involved in the prevention of non-alcoholic steatohepatitis in mice by Diethyldithiocarbamate

Background and Purpose: Diethyldithiocarbamate(DDC) alleviates hepatic inflammation and fibrosis of methionine- and choline-deficient(MCD) diet-induced non-alcoholic steatohepatitis(NASH) in mice. Interestingly, increased macrovesicular steatosis replace the ballooning of hepatocytes by DDC. The therapeutic mechanism of DDC on NASH remains unclear. Experimental Approach: C57BL/6 mice received choline-deficient, L-amino acid-defined(CDAA) diet to induce NASH with or without DDC treatment. Lipidomic and microarray analyses were used to find the lipid metabolites and genes regulated by DDC. RNAscope and immunoblotting were used to detect perilipin 5(Plin5) in the liver. Peridroplet mitochondria(PDM) were isolated from liver tissues, stained and observed by confocal microscope. Mixture of Oleic and palmitic acid were used to treat C3A cells. The effect of DDC on Plin5, mitochondria-LD contact and mitochondrial function were analyzed. Key Results: DDC alleviated hepatic inflammation and fibrosis, whereas steatosis increased in CDAA-diet induced NASH. Triglyceride content and genes related to LDs and mitochondrial function increased by DDC. Plin5 which can promote the expansion of LD and formation of PDM was upregulated in the liver by DDC. PDM were observed in steatotic liver and have enhanced mitochondrial function relative to cytoplasm mitochondria. DDC increased the size of LDs and the number of PDM, and improved mitochondrial function both in vivo and in vitro. Conclusion and Implications: PDM promote triglyceride synthesis and reduce lipotoxicity-induced liver injury, inflammation and fibrosis. PDM regulated by Plin5 contribute to the therapeutic effect of DDC on NASH. The regulation of PDM may represent an attractive pharmacological target for NAFLD.