OBJECTIVETo investigate the changes of osteopontin (OPN) in the liver tissues during nonalcoholic fatty liver fibrosis in rats and to explore the effect of OPN in the development of nonalcoholic fatty liver fibrosis.

METHODSFifty-six male Wistar rats were randomly divided into a control group (8 rats) and a high-fat diet group. The high-fat diet group was divided into 6 subgroups (8 rats in each subgroup) with high-fat feedings for 4, 8, 12, 16, 20 or 24 weeks. Conventional histochemical, HE, Masson-trichrome and immunohistochemical staining for alpha-smooth muscle actin (a-SMA) were performed with the liver histological preparations. The expression of OPN was detected with reverse transcription and polymerase chain reactions and Western blot.

RESULTSLevels of OPN in liver tissues in rat nonalcoholic fatty liver fibrosis induced by high-fat diet were significantly increased over those in the control group (F=7.15, P less than 0.01). OPN expressions were closely correlated with a-SMA and nonalcoholic fatty liver fibrosis, and correlation coefficients of the two groups were 0.94 and 0.82, and both P values were less than 0.01.

CONCLUSIONExpression of OPN increases dramatically in the livers during the development of nonalcoholic fatty liver fibrosis, and OPN may play an important role in this event.