Changes in hepatic protein expression in spontaneously hypertensive rats suggest early stages of non-alcoholic fatty liver disease

Abstract

Hypertension is a systemic disorder affecting numerous physiological processes throughout the body. As non-alcoholic fatty liver disorder (NAFLD) is a common comorbidity of hypertension in humans, we hypothesized that molecular hepatic physiology would be altered in a model of genetic hypertension. Despite the broad use of the spontaneously hypertensive rat (SHR) model, little is known regarding how hypertension influences hepatic function under basal conditions. In order to determine whether hypertension induces changes in the hepatic protein expression suggestive of early stages of NAFLD, we compared the whole tissue proteome of livers from SHR and Wistar Kyoto (WKY) 16 week old rats using 2DGE and MALDI-TOF MS. Fifteen proteins were identified that display different levels of expression between the SHR and WKY livers: 50% of proteins have mitochondrial or anti-oxidant functions while 20% are involved in lipid metabolism. Quininoid dihydropterin reductase, sulfite oxidase, and glutathione-S-transferase mu 1 were all identified as either undergoing a difference in post-translation modification or a difference in protein abundance in SHR compared to WKY livers. As oxidative stress is a well described component of both NAFLD and hypertension in SHR, the identification of novel changes in protein expression provides possible mechanisms connecting these two pathologies in humans.