Nonalcoholic fatty liver disease (
NAFLD) encompasses a spectrum ranging from simple steatosis to
cirrhosis. Hepatocellular
lipid accumulation is a hallmark of both nonalcoholic steatosis and
steatohepatitis (NASH). The latter develops upon pro-inflammatory cell infiltration and is widely considered as the first relevant pathophysiological step in
NAFLD-progression. The
chemokine CCL5/
RANTES plays an important role in the progression of hepatic
inflammation and
fibrosis. We here aimed to investigate its expression in
NAFLD. Incubation of primary human hepatocytes with
palmitic acid induced a dose-dependent
lipid accumulation, and corresponding dose-dependent
RANTES induction in vitro. Furthermore, we observed significantly elevated hepatic
RANTES expression in a dietary model of
NAFLD, in which mice were fed a high-fat diet for 12 weeks. This diet induced significant hepatic steatosis but only minimal
inflammation. In contrast to the liver,
RANTES expression was not induced in visceral adipose tissue of the group fed with high-fat diet. Finally,
RANTES serum levels were elevated in patients with ultrasound-diagnosed
NAFLD. In conclusion, our data indicate hepatocytes as cellular source of elevated hepatic as well as circulating
RANTES levels in response to hepatic steatosis. Noteworthy, upregulation of
RANTES in response to
lipid accumulation occurs in the absence of relevant
inflammation, which further indicates that hepatic steatosis per se has pathophysiological relevance and should not be considered as benign.