The Effect Of Angiotensin-(1-7) On Phosphorylation Of P38 MAP Kinases Induced By Angiotensin Ⅱ In Cultured Human Umbilical Vein Cells

Background&ObjectivesRecent studies suggest that atherosclerosis is a chronic inflammatory disease, p38 is one member of the mitogen-activated protein kinase family(MAPK). After p38MAPK activiated, it is involved in inflammation. AngiotensinⅡ(AngⅡ) is an important active factor in renin-angiotensin system (RAS). It plays a cruial role in atherosclerosis. It can induce the expression of the phosphorylation of p38MAPK via AT1 receptor, which can induce the expression of many inflammatory factors , promote monocyte adhering to endothelial cells. Angiotensin-(1-7) [Ang-(1-7)] is a new member of RAS. It can inhibit the effects induced by AngⅡ, for example, having antihypertensive, antiproliferative and diuresis effects. However, it remains unknown whether Ang-(1-7) can inhibit the expression of the phosphorylation of p38MAPK induced by AngⅡin human umbilical vein Cells (HUVECs). The present study was undertaken to investigate the effects of Ang-(1-7) on inhibiting the inflammation induced by AngⅡ. In this experiment, the cultured HUVECs were incubated with Ang-(1-7), AngⅡand the specific inhibitors of Ang-(1-7), A-779. The expression of the phosphorylation of p38MAPK was determined by Western blot, and the mRNA expression of the Mas receptor was determined by reverse transcriptional (RT) PCR. We want to discover the possible mechanism that Ang-(1-7) inhibit the effect of AngⅡon the inflammation.Further more, we want to discover the active function induced by Ang-(1-7) to the Cardiovascular diseases.Methods1. Culture and identification of HUVECs.2. Group: 1) Determining the expression of the phosphorylation of p38MAPK by Western blot:Ⅰ(1) Control group: the HUVECs were incubated in DMEM without any stimulators or inhibitors; (2) Ang-(1-7) group: the HUVECs were treated with the final concentration Ang-(1-7) 100nmol/L for 20min; (3) AngⅡgroup: the HUVECs were stimulated with the final concentration AngⅡ100nmol/L for 5min; (4) Ang-(1-7) + AngⅡgroup: the HUVECs were pretreated with the Ang-(1-7) 100nmol/L for 20min,then added the AngⅡ100nmol/L for 5min; (5) A-779 + Ang-(1-7) + AngⅡgroup: the HUVECs were pretreated with the certain A-779 of 10,000nmol/L for 10min, then added Ang-(1-7) 100nmol/L for 20min, finally stimulated with the final concentration AngⅡ100nmol/L for 5min;(6) A-779 group:the HUVECs were singly treated with the final concentration A-779 10,000 nmol/L for 10min.Ⅱ(1)Control group: the HUVECs were incubated in DMEM without any stimulators or inhibitors; (2) AngⅡgroup: the HUVECs were stimulated with the final concentration AngⅡ100nmol/L for 5min; (3)—(6) Ang-(1-7)+AngⅡgroup: the HUVECs were respectively pretreated with Ang-(1-7) 10nmol/L,100nmol/L, 1000nmol/L,10,000mol/L for 20min, then added the final concentration AngⅡ100nmol/L for 5min.2) Determining the mRNA expression of the Mas receptor by reverse transcriptional polymerase chain reaction (RT-PCR). (1)—(5)group: the HUVECs were respectively pretreated with Ang-(1-7) 0 nmol/L ,10nmol/L,100nmol/L, 1000nmol/L,10,000mol/L for 20min.Results1. The HUVECs arrayed like pitching stone under light microscopy; VⅢfactor in HUVECs showed positive reaction by immunohistochemistry. All these cells were identified as ECs.2. Compared with the control group,100nmol/L AngⅡinduced the expression of the phosphorylation of p38MAPK.3. Compared with the AngⅡgroup, the expression of the phosphorylation of p38MAPK reduced in the AngⅡ(100nmol/L) plus Ang-(1-7) (100nmol/L) group. With the increase in concentration of Ang-(1-7), the expression of the phosphorylation of p38MAPK reduced in the AngⅡ(100nmol/L)+ Ang-(1-7) (10,100,1000,10,000nmol/L) group.4. The expression of the phosphorylation of p38MAPK was unaffected in the A-779+Ang-(1-7)+ AngⅡgroup.The expression of the phosphorylation of p38MAPK were similar among Ang-(1-7), A-779 and control groups.Conclusions1. AngⅡsignificantly induces the expression of the phosphorylation of p38MAPK in cultured HUVECs.2. Ang-(1-7) dose-dependently inhibits the expression of the phosphorylation of p38MAPK induced by AngⅡin HUVECs .3. Ang-(1-7) rises the function by combining with the specific receptor Mas.