Objective To investigate the effects of microRNA(miR)-30a-regulated MAPK pathway on the formation of intercalation,inflammatory factors and vasoconstriction in a rat model of aortic coarctation.Methods Fifty SD rats were selected to establish the rat model of aortic coarctation,and were randomly divided into control group,model group,miR-NC group,miR-30a group and miR-30a inhibitor group,10 rats in each group.Histopathological changes in the aortic tissue and changes in the elastic fibers and collagen fibers of the aortic mesothelium were observed;The expression of miR-30a,systolic blood pressure before and after the intervention and the expression of serum inflammatory factors in each group were measured by PCR,tail artery manometry and ELISA;Matrix metalloproteinase(MMP)-6,MMP-2 protein expression and MAPK pathway were measured by Western blotting in each group.The expression of MMP-6,MMP-2 and MAPK pathway related proteins were measured by Western blotting.Results The miR-30a inhibitor group improved the degree of vessel wall tearing and disorganized internal arterial wall arrangement;The miR-30a group improved vascular remodeling;miR-30a expression was higher in the model group compared with the control group,and lower in the miR-30a group and miR-30a inhibitor group compared with the miR-NC group,P<0.05;Before the intervention,the difference in systolic blood pressure between the groups compared was not statistically significant,P>0.05;Compared with the control group,systolic blood pressure was higher in the model group,higher expression in the miR-30a group and lower expression in the miR-30a inhibitor group compared with the miR-NC group,P<0.05;compared with the control group,tumor necrosis factor(TNF)-α,interleukin(IL)-6,IL-1β expression was higher in the model group,higher expression in the miR-30a group compared with the miR-NC group,lower expression in the miR-30a inhibitor group,P<0.05;higher expression of TNF-α,MMP-6,MMP-2,Ras,Raf,P38 MAPK,ERK1/2 proteins in the model group compared with the control group,higher expression in the miR-30a group compared with the miR-NC group,lower expression in the miR-30a inhibitor group,P<0.05.Conclusion MiR-30a is involved in the process of aortic coarctation formation,inflammatory response,and regulation of aortic coarctation vascular remodeling,possibly through regulation of the MAPK signaling pathway.