Study On The Mechanism Of Foaming In THP-1 Derived Macrophages Evoked By Angiotensin Ⅱ

PartⅠInfluence of angiotensinⅡon cholesterol content in THP-1 derived macrophagesObjective To study the influence of angiotensinⅡ(AngⅡ) on THP-1 derived macrophages, the variance of the content of cholesterol were investigated.Methods The monocytes derived from THP-1 were induced into macrophages by PMA, then we incubated them with oxidized low-density lipoprotein (oX-LDL) (50mg/L) for 48 hours, simultaneously, different concentration of AngⅡand Irbesartan were added in. The regulated effect of AngⅡon the variance of cholesterol content was measured by zymochemistry via-fluorospectrophotometer.Results A positive facilitative effect of AngⅡon macrophages was observed in a dose-dependent manner. Total cholesterol content was increased significantly by AngⅡ(p<0.05), receptor antagonist of AngⅡ: Irbesartan can reduce the total cholesterol content significantly (p<0.05).Conclusion AngⅡhas the positive effect on increasing the cholerterol content in THP-1 derived macrophages, and promoting the formation of foam cells and accelerating the development of atherosclerosis. PartⅡInfluence of angiotensinⅡon ATP binding cassette transporter A1 in THP-1 derived macrophagesObjective To study the influence of angiotensinⅡ(AngⅡ) on the expression of ATP-binding cassette transporter A1 in THP-1 derived macrophages.Methods THP-1 derived forms cells were incubated with oxidized low-density lipoprotein (oX-LDL)(50mg/L) for 48 hours, simultaneously , different concentration of AngⅡand Irbesartan were added in. The regulated effect of ABCA1 mRNA and protein of AngⅡon THP-1 derived form cells was measured by RT-PCR and Western blot.Results A positive facilitative effect of AngⅡon form cells was observed in a dose-dependent manner. The mRNA and protein of ABCA1 was down-regulated remarkably by AngⅡ, the descendent amplitude are (10.5±1.9) %,(22.6±5.3) %,(44±3.7)% and(17.5±4.4)%,(28.7±7.0) %,(48.5±8.5)% ,compared with control group (p<0.05).Conclusion The promoting effects of AngⅡon the formation of foam cells and atherosclerosis are in a dose-dependent manner, which may be correlated to it's activity of down-regulating the expression of ABCA1.Irbesartan has some negative effects on it.