OBJECTIVETo explore liver X receptor alpha (LXR alpha) gene changes and their significance in nonalcoholic fatty liver disease (NAFLD) in rats.

METHODSA rat model of nonalcoholic fatty liver disease was produced with a fatty diet regime (feeding group, FG). Rats fed with normal diet served as controls (CG). The mRNA and protein expressions of LXR alpha in liver tissues were detected by reverse transcription and polymerase chain reaction (RT-PCR) and Western blot.

RESULTSThe concentration of free fatty acid (FFA) in the sera of GF rats started to increase to 0.33 mmol/L after 4 weeks of fat diet feeding, while the FFA of the CG was just 0.24+/-0.03 mmol/L, and the difference was significant (P<0.05). The concentration of ALT and AST in sera of the FG rats started to increase to 75.8 U/L and 138.9 U/L at the 8th week, much higher than those of the CG (P<0.01), and at the 12th week they increased further (P<0.01). Meanwhile, the mRNA and protein expressions of LXR alpha at the 2nd week was significantly increased to 0.62 (P>0.01) and its peak was reached at the 12th week (P<0.01). There was a significant positive correlation between the expression of LXR alpha and the degree of NAFLD.

CONCLUSIONThe changes of LXR alpha gene are closely related to the development of nonalcoholic fatty liver disease.