Aim To investigate the role of peroxisome proliferator-activated receptor-γ(PPARγ)signal transduction pathway in the up-regulation of the expressions of acyl-CoA:cholesterol acyltransferase 1(ACAT1)and discuss the mechanism of macrophages-derived form cell formation induced by visfatin.Methods THP-1 monocytes were induced into macrophages by 160 nmol/L phorbol myristate acetate(PMA)for 48 h,then exposed to visfatin and PPARγ activator rosiglitazone.The lipid droplet contents were observed by Oil red staining.The expressions of PPARγ and ACAT1 mRNA and protein were determined by reverse transcriptase-polymerase chain reaction(RT-PCR)and Western blotting respectively.The contents of total cholesterol(TC)and free cholesterol(FC)were detected by enzyme fluorescence analysis.Results Compared with the control group,the lipid droplet contents were increased,the expressions of PPARγ mRNA and protein were down-regulated,the expressions of ACAT1 mRNA and protein were up-regulated,and the contents of cholesterol ester(CE)were increased in visfatin groups.Compared with the visfatin group,the expressions of ACAT1 mRNA and protein were down-regulated in rosiglitazone groups.Conclusion The up-regulation of ACAT1 expression was induced by visfatin via PPARγ signal transduction pathway,which induced foam cell formation.