| In recent years, it has been proved that (pro)rennin receptor((P)RR)is a new active substance in renin angitensin system(RAS). Two types of (pro)renin receptor have been cloned until date, one is mainnose-6-phosphate/insulin-like growth factorâ…¡receptor(M6P/IGF2R) which thought to be involved in the clear mechanisms of (pro)renin, the other is the functional receptor (P)RR. Nowsdays, more and more attention has been paid to (P)RR in the heart and kidney disease. It was confirmed that (P)RR exists in the renal mesangial cells, vascular smooth muscle cells, kidney, heart, brain and other cells and tissues. (Pro)renin receptor-bound prorenin and renin activates the intracellular signaling pathways independent of the generated angiotensinâ…¡(Ang-â…¡), up-regulate of genes expression. Mitogen-activated protein kinases (MAPKs) are serien/ threonine-specific protein kinases that respond to extracellular stimuli and regulate various cellular activities, such as cell proliferation, differentiation, transformation and apoptosis. MAPKs family include extracellular signal regulated kinase (ERK), stress-activated c-Jun N-terminal kinase (JNK/ SAPK), and p38/RK/CSBP protein kinase. Extracellular signal-regulated kinase 1/2 (ERK1/2) and p38 MAPKs are two of MAPKs which play an important role in inflammation and oxidative stress. Our group has found that (P)RR existes in the human umbilical vein endothelian cells(HUVECs) by immunohistochemistry. but it was not yet reported the effect about (P)RR on inflammatory factors VCAM-1 expression and oxidative stress on HUVECs and whether interference (P)RR could inhibited these effects. It was not clear whether inflammation and oxidative stress induced by (P)RR were relatived to signaling pathway ERK 1/2 and p38 MAPKs.Objectives:To investigate whether (pro)renin can activate the (P)RR leading to the phosphorylation of ERK and p38 MAPK singaling pathway and increase the expression of VCAM-1 and reduce the activity of SOD. Thus to study the mechanism about (P)RR on endothelial damage, explain the relationship between (P)RR and cardiovascular disease such as atherosclerosis(AS).Methods:1.HUVECs were cultured in vitro, indentified by CD34 Flow Cytometry2.HUVECs were incubated with (P)RR siRNA respectively 24,48 and 72 hours, the mRNA of (P)RR expression was detected by RT-PCR.3.To determine the (pro)renin stimulation time on HUVECs, ERK1/2 and p38 pathway protein phosphorylation were checked by western blot when 5,10,20,35,60,90 minutes after treatment with (pro)renin on HUVECs. Ang-â…¡receptor AT1 and AT2 were blocked by Olmesartan and PD123319.4.Ang-â…¡receptor AT1 and AT2 were blocked by Olmesartan and PD123319. Western blot was used to detected whether signaling pathway ERK1/2 and p38 were phosphorylated, ELISA was used to checked whether vascular cell adhesion molecule VCAM-1 expression was increased and Colorimetry was used to detected whether antioxidant SOD activity was reduced, and whether all these reactions were inhibited after (P)RR was interferenced.Results:1.98.35% HUVECs were identificated by CD34 Flow Cytometry.2.The weakest expression of (P)RR mRNA was at the point of 72 hours after interfered with (P)RR-specific siRNA.3.In HUVECs, ERK 1/2 and p38 MAPKs protein were significantly phosphorylated after stimulated with (pro)renin, which were time dependent.4.ERK and p38 MAPKs singaling pathways were provoked and the expression of VCAM-1 was increased and the activity of SOD was decreased by (pro)renin, while interfered (P)RR could inhibite these reactions. Conclusion:(P)RR expresses on HUVECs. Prorenin and renin can activate the (P)RR, lead to oxidative stress and increase phosphorylation of ERK and p38 MAPKs protein and increase the expression of VCAM-1 by independent Ang-â…¡way. Thus lead to endothelial damage disease. But all these effects can be inhibited by interfering (P)RR. So interfere (P)RR play a role in endothelium protection. A new evidence was provided in clinical treament about endothelial damage disease.
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