The Effect Of MicroRNA-24 On Vascular Endothelial Nitric Oxide Synthase And Plasma NO And Its Mechanism

Objective: In this study,a transfected rat model was constructed by in vivo mock transfection and the effects of microRNA-24 on vascular histomorphology,eNOS expression,activity,eNOS mRNA expression,and plasma NO in adult male rats were investigated.MicroRNA-24 is involved in the regulation of vascular endothelial cells in male rats and the mechanism involved in the development of hypertension.Methods: 1.Construction of microRNA-24 high expression plasmid and construction of in vivo transfected rat model: 6-8 week old SD(SPF)healthy male rats and spontaneously hypertensive rats(SHR)were selected.Methods In vivo transfection environment was simulated.Transient transfection technique was used to inject micro RNA-24high-expression plasmid and blank plasmid into the tail vein of rats respectively.Vascular tissue sections were taken and the expression of each plasmid in vivo was verified by fluorescence microscope.Successful construction of a transfected rat model.2.Experimental verification:(1)Detect the green fluorescence of rat vascular tissue;(2)HE staining wasused to observe the morphological changes of rat vascular tissue after transfection;(3)Using immunohistochemical method to observe the changes of eNOS protein in rat vascular tissue after transfection;(4)ELISA was used to detect the plasma eNOS activity in transfected rats;(5)Determination of NO in the plasma of rats by nitric acid reduction;(6)The expression of eNOS mRNA in rat vascular tissue was analyzed by real-time fluorescence quantitative PCR.Results: 1.After injection of microRNA-24 high-expression plasmid and blank plasmid into tail vein of healthy adult male rats,green fluorescence was detected in rat vascular tissues of both groups.The results showed that plasmids were introduced into rat arterial tissue and the transfected rat model was successfully constructed;2.blank plasmid SD group vascular tissue structure of each layer is smooth,smooth endometrium,normal media elastic fiber.Compared with the blank plasmid SD group,the vascular tissue of microRNA-24 SD group and SHR group had no obvious changes;3.The expression of eNOS protein in vascular tissue of normal rats after injection of microRNA-24 plasmid was significantly lower than that of the blank plasmid group.,The level was close to the SHR group;4.After the microRNA-24 plasmid injection treatment,the plasma eNOS activity in rats was significantly decreased compared with the blank plasmid group(P<0.05),the level was close to the SHR group;5.The expression of eNOS mRNA injected with the microRNA-24 plasmid was significantly lower than that of the empty plasmid group(P<0.05),and the decline was similar to that of the SHR group.The difference was statistically significant.Conclusion:1.This experiment successfully established an in vivotransfection rat model,which can provide sufficient theoretical and experimental basis for future research and other disease research;2.The expression and activity of eNOS in rat vascular tissue were inhibited by high expression of microRNA-24;3.The synthesis and release of plasma metabolites NO were inhibited by high expression of microRNA-24;4.High expression of microRNA-24 can inhibit the expression of eNOS mRNA in rat vascular tissue;5.micro RNA-24 may affect the vascular tissue state and blood pressure balance by inhibiting the expression of eNOS,the enzyme activity and the synthesis of NO,which is a metabolite of microRNA-24,which may lead to the occurrence and development of cardiovascular diseases such as hypertension;6.microRNA-24 is expected to provide the basis for the preparation of molecular drugs and the prevention and treatment of hypertension and other diseases.