Objectives: To observe the role of PPARgamma during the activation process of hepatic stellate cells (HSC).
Methods: By morphology and RT-PCR, we study the changes of expression of PPARgamma in culture-activated HSC or in vivo activated HSC induced by dimethylnitrosamine (DMN).
Results: In vitro, the expression level of PPARgamma in freshly isolated HSC (0.72+/-0.01) significantly reduced to 0.48+/-0.03 on the third day of culture (t = 19.8372, P<0.01), and reduced 70% on the seventh culture-day and could not be detected after the second passage. In vivo, HSC freshly isolated from normal control rats expressed PPARgamma (0.76+/-0.01). During the development of rat liver fibrosis induced by DMN, the expression level significantly reduced to 0.46+/-0.02 after the third injection of DMN (t = 29.5318, P<0.01), and reduced 66% on the end of first week and could not be detected on the end of second and third week.
Conclusion: The expression of PPARgamma might play an important role on the maintenance of resting-form of HSC, and the reduction of expression of PPARgamma might be an early event during the activation process of HSC.