Inhibition of endoplasmic reticulum stress and activation of autophagy-protect intestinal and renal tissues from western diet-induced dysbiosis and abrogate inflammatory response to LPS: role of vitamin E.

Abstract

Diet pattern is an emerging risk factor for renal disease. The mechanism by which high-fat high fructose (western) diet mediates renal injury is not yet fully understood. The objective of the present study was to investigate the relationship between endoplasmic reticulum (ER) stress and autophagy in the development of renal impairment and aggravation of the inflammatory response. Eighty male rats were randomly divided into four groups as follows: a standard diet-fed (ConD), a high-fat high fructose diet fed (HFHF-V), ConD fed and orally supplemented with vitamin E (ConD-E), and HFHF fed and orally supplemented vitamin E (HFHF-E). After 12 weeks, either lipopolysaccharide (LPS) or saline was injected. We found that upregulation of endoplasmic reticulum stress-related proteins rendered the cells susceptible to injury induced by dysbiosis and microbiota-derived metabolites. A downregulation of autophagy and upregulation of caspase-12 resulted in the loss of intestinal integrity and renal tubular injury. Maintained ER stress also increased the inflammatory response to LPS. In contrast, vitamin E effectively ameliorated ER stress and promoted autophagy to protect intestinal and renal tissues. Our results provide insight into the influences of sustained ER stress activation and autophagy inhibition on the development of renal injury, which may contribute also to the enhanced inflammatory response.