[Increased expression of PPargamma in fatty liver induced by high fat diet]

Mice were fed with control or high fat diet containing approximately 10% or 80% cholesterol, respectively. Macroscopic and microscopic findings demonstrated that lipid accumulation in the liver was observed as early as 2 weeks after high fat diet and that high fat diet for 12 weeks developed a fatty liver phenotype, establishing a novel model of diet-induced liver steatosis. PPARgamma and its targeted gene, CD36 mRNA expression were specifically up-regulated in the liver by high fat diet for 2 weeks. Immunohistochemical study revealed that PPARgamma protein expression is increased in the nuclei of hepatocytes by high fat diet. These results suggest that PPARgamma signaling pathway may be involved in the high fat diet-induced liver steatosis.