Canagliflozin Attenuates Hepatic Steatosis and Atherosclerosis Progression in Western Diet-Fed ApoE-Knockout Mice

Purpose: To investigate the effect of canagliflozin (20 mg/kg) on hepatic steatosis and atherosclerosis, and further to explore its possible mechanism.Methods: Blood glucose, blood lipid, oxidative stress response and inflammatory cytokines were examined by intraperitoneal glucose tolerance test and ELISA assay. HE and Oil Red O staining were used to estimate the extent of hepatic steatosis and atherosclerosis. RNA-seq and qRT-PCR were used to further investigate the potential mechanism. The effects of canagliflozin on autophagy were detected using transmission electron microscopy and Western blotting. The endothelial function-related markers were determined by qRT-PCR. Results: Canagliflozin notably alleviated the elevation in blood glucose and insulin resistance in western diet-fed ApoE-/-mice. In ApoE-/-+Cana group, ApoE-/-mice had lower levels of TG, TC, LDL-C, TNF-alpha, IL-6, IL-1 beta, and MCP-1. HE and Oil Red O staining presented that canagliflozin restrained the atherosclerotic plaque development and lipid accumulation. RNA-seq showed that 87 DEGs were relevant to improvement of hepatic steatosis and atherosclerosis by canagliflozin. Among them, CPS1, ASS1, ASL, ARG1, MATLA, GLS2, GOT1, SREBP1, Plin5, Retreg1, and C/EBP beta were verified. KEGG enrichment analysis indicated that DEGs were mainly involved in amino acid metabolism. Besides, we observed that canagliflozin reduced the contents of aspartic acid and citrulline in liver. Western blotting showed that ASS1 and p-AMPK/AMPK was remarkably elevated after administration of canagliflozin. Correspondingly, canagliflozin down-regulated SREBP1, FAS, ACC1, HMGCR, p-mTOR/m-TOR, p-ULK1/ULK1 and p62, but up-regulated CPT1, Beclin 1 and LC3 II/LC3I. TEM showed that canagliflozin reduced the number of lipid droplets and increased the autophagosomes. Moreover, we found that canagliflozin elevated the aortic endothelial function-associated markers including ASS1, ASL and eNOS.Conclusion: Canagliflozin may attenuate hepatic steatosis by improving lipid metabolism, enhancing autophagy, and reducing inflammatory response through ASS1/AMPK pathway. Besides, canagliflozin further effectively improves the aortic endothelial function, thereby suppressing atherosclerosis development.Keywords: canagliflozin, hepatic steatosis, atherosclerosis, RNA-seq, dyslipidemia, inflammatory response, autophagy

Automated summary

The study found that canagliflozin can attenuate hepatic steatosis by improving lipid metabolism, enhancing autophagy, and reducing inflammatory response. In addition, canagliflozin can effectively improve the aortic endothelial function, thereby suppressing the development of atherosclerosis.