Influence Of Angiotensin-(-7) And Angiotensin â…¡ On The Expression Of NPC1 And Cholesterol Effluent In THP-1 Macrophages

ObjectiveThe present study was undertaken to investigate the effect of angiotensin-(1-7) [Ang-(1-7) ]and angiotesinⅡ(AngⅡ) on the expression of NPC1 in THP-1 macrophages. The rate ofcholesterol effluent was also investigated.Methods1. Macrophages were converted from THP-1 monocytes induced by PMA for 48 h2. Experimental group:the experiment is divided into two partsPart 1 Effect of angiotesin II on expression of NPC1 in THP-1 macrophages.①Control group: the THP-1 cells were incubated in 1640 without any stimulators orinhibitors;②AngII10nmol/L；③AngII100nmol/L；④AngII1000nmol/L；⑤AngII10000nmol/L。Part 2 Effect of angiotesin II and angiotesin1-7 on expression of NPC1 in THP-1 macrophages①Control group: without any stimulators or inhibitors;；②AngII 1000 nmol/L③Ang-(1-7 )1000nmol/L；(4)AngⅡ1000nmol/L + Ang-(1-7) (100 nmol/L,1000 nmol/L,10000 nmol/L ) (5)AngⅡ1000 nmol/L + Ang-(1-7) 1000 nmol/L +A- 7791000 nmol/LNPC1 mRNA and protein levels were determined by reverse transcription-polymerase chainreaction (RT-PCR) and Western blot respectively.3. The Cells were radio labeled with 0.37×10~9 Bq /L of [~3H]cholesterol befor treated by AngⅡandAng-(1-7). Cholesterol effluent was measured by liquid scintillator .Results1. The normal cell growths fine,investigate throught light microscopy,mononuclear cell isfloating in 1640;The cell induced by phorbolester 160nmol/L for 48 hours,then, mononuclearcell becomes adherence,the appearance is anomal,stretch out pseudopod;2. Compared with the control group, the expression of NPC1 mRNA and protein weredownregulated significantly when incubated with Ang II dose-dependently. Meanwhile, theeffluent rate of cholesterol was also decreased.3.Compared with the control group, the expression of NPC1 mRNA and protein weredownregulated significantly when incubated with Ang II and the effluent rate of cholesterol wasalso decreased i(P<0.05).Ang-(1-7) dose-dependently inhibited the reduction of NPC1 inducedby AngⅡ,and promoted the cholesterol efflux(P<0.05), however, when incubated with (A-799),an inhibitor of Ang-(1-7), the effects of Ang-(1-7) on inhibiting the expression of NPC1 mRNA were significantly attenuated.Conclusion1.AngiotesinⅡmay inhibit the expression of NPC1 in THP-1 macrophages and decrease theeffluent rate of cholesterol, contributing to the development of atherosclerosis2.Angiotesin 1-7 may significantly upregulate NPC1 expression and increase the effluent rate ofcholesterol in THP-1 macrophages3.Angiotesin 1-7 can dose-dependently oppose the reduction of NPC1 and the effluent rate ofcholesterol by Ang II4.Angiotesin 1-7 concentration-dependently attenuate the reduction of NPC1 and the effluentrate of cholesterol induced by Ang II through its specfic receptor Mas...