The Effects Of ShRNA Targeting Type 1 Angiotensin Ⅱ Receptor On Blood Pressure And AT1R MRNA Expression In Spontaneously Hypertensive Rats.

PartⅠthe Effects of shRNA targeting type 1 Angiotensin II Receptor on Blood Pressure and AT1R mRNA expression in Spontaneously Hypertensive Rats.Objective: To investigate the effects of retroviral vector containing shRNA targeted to the rat type 1 angiotensinⅡreceptor gene (Ad5-AT1R-shRNA)on blood pressure in spontaneously hypertensive rats (SHR), and the inhibitory effect of RNA interference(RNAi) on AT1R mRNA expression in SHR. Methods:Retroviral vector containing shRNA targeted to the rat type 1 angiotensinⅡreceptor gene was constructed and propagated further in 293 cells.Then the retroviral titer was checked by TCID50。22 spontaneously hypertensive rats were randomly divided into two groups (n=11): SHR control group(SHR group) and experimental group.11 male Wistar-Kyoto rats(WKY) were selected as normal control group (WKY group). Experimental group SHRs were injected intravenously with Ad5-AT1R-shRNA , 1.7×109 TCID50/ml.SHR group and WKY group both were injected intravenously with control retroviral vector (Ad5-EGFP), 7.9×109 TCID50/ml .Systolic blood pressure (SBP) and were measured before and after treatment with single intravenous injection of Ad5-AT1R-shRNA.When the blood pressure was decreased ,a part of animals were dead ,and their heart ,liver,kidney, aorta and adrenal gland were taken out. To identify the sites of Ad5-AT1R-shRNA expression, fluorescence microscope as used to observe different organs in the Ad5-AT1R-shRNA treated rats.The expression of AT1R mRNA in liver,kidney and aorta was detected by fluorescence quantitative PCR. Results:After single injection 24 hours , administration of Ad5-AT1R-shRNA effectively reduced blood pressure by 28.902mmHg compared with controls(P<0.05).This antihypertensive effects with Ad5-AT1R-shRNA could last up to 5 to 7 days.SHR group and WKY group could not significantly reduce hypertension,but SHR group animals partly produced a increase in blood pressure.However,the heart rate is not affected by the Ad5-AT1R-shRNA .Under the fluorescence microscope,we can see marked expression in heart,liver, kidney ,aorta and adrenal gland.So the uptake sites are in the heart,liver,kidney,aorta and adrenal gland.Furthermore,AT1R mRNA levels of kidney and aorta were significantly decreased in the Ad5-AT1R-shRNA treated rats compared with SHR control rats(P<0.01). Conclusion:The results indicate that Ad5-AT1R-shRNA can be absorbed by many main organs and inhibit the expression of AT1R mRNA to produce a prolonged duration of decrease in blood pressure.PartⅡthe Effects of shRNA targeting type 1 Angiotensin II Receptor on ventricular remodeling in spontaneously hypertensive rats.Objective: To investigate the effects of retroviral vector containing shRNA targeted to the rat type 1 angiotensinⅡreceptor gene on ventricular remodeling in spontaneously...