The Role Of MiRNA-221 In Arginine Influences Atherosclerosis In Rats

Part I:The expression of miRNA-221, eNOS in aortic of atherosclerosis rats treated with arginine.Objective:(1)To investigate the effects of arginine on prevention and treatment of atherosclerosis in Sprague-Dawley rats. (2)To explor the role of miRNA-221, endothelial nitric oxide synthase in atherosclerosis formation of Sprague-Dawley rats treated by arginine.Methods:(1) 60 Sprague-Dawley rats were assigned randomly into 6 groups as normal group(n=10), high fat group(n=10), arginine prevention group(n=10), arginine treatment group(n=10), simvastatin group(n=10), combination treatment group (n=10). The other 5 groups were given high fat diet except of the normal group (arginine prevention group added with arginine) for 12 weeks. After 12 weeks, normal group and high fat group was given saline, arginine prevention and arginine treatment group was given arginine intragastric administration and simvastatin group was given simvastatin, combined treatment group was given arginine and simvastatin intragastric administration for 12 weeks before sacrifice. (2) Serum levels of hs-CRP were detected, aortal pathology changes were observed of eanch group. (3) The expression level of miRNA-221 in rat aorta of each group was detected by real-time PCR, and the expression level of eNOS was detected by western blot.Results:(1) The aortic intima thickness of other 5 groups were increased in addition to the normal group in aorta routine pathological tip. The thickness of aortic intima thickness decreased significantly in arginine treatment group, arginine prevention group, simvastatin group and combined treatment group compared with high fat group(p<0.05). (2) The level of serum hs-CRP in other 5 groups were increased compared with nomrmal group. The level of serum hs-CRP decreased significantly in arginine treatment group, arginine prevention group, simvastatin group, combination treatment group compared with high fat group (p<0.05). (3) The level of miRNA-221 expression were higher in other 5 group than the normal group, the level of miRNA-221 expression decreased significantly in arginine prevention group, simvastatin group, combination treatment group compared with high fat group(p<0.05); The level of eNOS expression were lower in other 5 group than the normal group, the level of eNOS expression increased significantly in arginine prevention group, simvastatin group, combination treatment group compared with high fat group(p<0.05).Conclusion:(1)Rats with high-fat diet can creat models of atherosclerosis. Rats with atherosclerosis can been reduced vascular endothelial inflammation reaction, alleviated intimal thickening, delayed the occurrence and development of atherosclerosis by given arginine oral administration. In addition to the way of increased the substrate concentration of eNOS, arginine may also reduce the expression level of miRNA-221 in aortic, and improve the level of eNOS in aortic to play a role of resistance to atherosclerosis, which remains to be further validated at the cellular level.Part II:The experimental study of the expression level of eNOS affected by miRNA-221 in primary cultured rat aortic endothelial cells.Objective:To investigate whether the miRNA-221 of rat aortic endothelial cells can regulate the expression of eNOS.Methods:The primary cultured Sprague-Dawley rat aortic endothelial cells were assigned randomly into 3 groups as control group, the negative control group, antagonism group. Control group was given Lipfectamine 2000 transfection intervention, the negative control group was given Lipfectamine 2000 and miRNA-221 NC mixture transfection intervention, antagonism group was given Lipfectamine 2000 and antagormiR-221 mixture transfection intervention. The eNOS mRNA was detected by real-time PCR, and the expression of eNOS was detected by western blot of each group.Results:The expression level of eNOS mRNA and eNOS protein of rat aortic endothelial cells were significantly increased of antagonism group compared with the control group and the negative control group(p<0.05);The level of eNOS mRNA and eNOS protein expressed by rat aortic endothelial cells between the control group and the negative control group have no significant statistical difference(p<0.05).Conclusion:The miRNA-221 of endothelial cells of rats can adjust eNOS expression.