Short-term intake of high fat diet aggravates renal fibrosis in aged Sprague-Dawley rats.

Abstract

Age- or high fat diet (HFD)-associated renal structural changes are commonly associated with a decline in renal function. Although HFD causes injurious effects in various organs during aging, its effects on age-associated renal fibrosis have not yet been investigated. In this study, we show that a short-term HFD significantly induces renal fibrosis by causing loss of mitochondrial integrity in aged Sprague-Dawley (SD) rats. To evaluate the effects of short-term HFD intake on age-associated renal fibrosis, we administered HFD in young and aged SD rats for 15days. Our results showed that a short-term HFD significantly increased the renal fibrosis and inflammation in aged rats. Moreover, mitochondrial integrity and the expression of fatty acid oxidation-related proteins decreased in the kidneys of the HFD-fed aged rats. Further, NRK52E renal tubular epithelial cells subjected to lipid stress by treatment with oleic acid showed a reduced amount of mitochondrial OXPHOS-related proteins. Our results suggest that short-term HFD affects mitochondrial integrity and exacerbates inflammation leading to renal fibrosis, especially in aged rats. We conclude that the mitochondrial integrity in kidney tissues is important in HFD-induced renal fibrosis development during aging.