MicroRNA-143-3p Overexpression Regulates SPRY3 To Activate Smads Pathway And Enhance Myocardial Fibrosis And Collagen Cross-linking

Background: Myocardial infarction(MI)remains the leading cause of heart failure and death in humans.The arrest of the flow of blood and hypoxia lead to cardiomyocyte necrosis,decreased function,and rational remodeling of heart disease.When MI occurs,cardiac fibroblasts(HCFs)proliferate,differentiate into myofibroblasts and produce excessive extracellular matrix(ECM)resulting in myocardial fibrosis and collagen cross-linking due to nonregenerative cardiomyocytes.Micro RNAs(miRNAs)are non-coding RNAs,approximately 18-22 nucleotide sequences,that inhibit gene expression by acting on the non-translated region(3’UTR)to degrade or inhibit the translation of target RNA.According to research,miR-143-3p was involved in increasing collagen III expression in fibroblasts,however,its mechanism of action in myocardial fibrosis and collagen cross-linking is still unclear.Sprouty(Spry)is widely expressed in mammals and can be divided into four types: Spry1,Spry2,Spry3 and Spry4,which regulate the cardiovascular system,nervous system and urinary upgrade system.With further research,SPRY3 is expressed not only in the brain and testis,but also in a variety of other tissues and cells,participating in their pathophysiological processes.Our previous studies have confirmed that SPRY3 is the target of miR-143-3p.However,the mechanism of SPRY3 in cardiac remodeling remains unclear.It has been reported that the Smads pathway plays an important role in collagen deposition and collagen cross-linking after myocardial infarction.The Smads family can be divided into three categories: receptor-regulated Smad,ordinary Smad and inhibitory Smads,SMAD2 and SMAD3 belong to receptor-regulated Smads,while SMAD7 belong to inhibitory Smads.The activation of Smad2 and Smad3 can promote collagen cross-linking and cardiac remodeling in the area of myocardial infarction.We have used bioinformatics predictive tools to show that SPRY3 may be involved in activation of the Smads signaling pathway through Homeobox(HOXA1)and growth differentiation factor-15(GDF-15).However,the regulation of the Smads pathway by SPRY3 is still unclear.Methods: MiR-143-3p and SPRY3 expression were detected in 7 autopsy specimens with a history of myocardial infarction and 7 blank control specimens without a history of heart disease.A mice myocardial infarction model was constructed.Antagomir-143-3p was injected into the tail vein one week after MI to reduce miR-143-3p level in the myocardial infarction mice,and the expression of myocardial fibrosis and collagen cross-linking in the mice were detected in groups(Sham,MI-NC,MI,antagomir-143-3p).In vitro experiments,miR-143-3p mimic and inhibitors were introduced into HCFs to observe the transformation,migration and changes of HCFs as well as its related mechanisms in myocardial fibrosis and collagen cross-linking.p EX4-SPRY3 and si-SPRY3 were transferred into HCFs to explore the relationship between silent SPRY3 and Smads pathway.Results:1.In human autopsy specimens,miR-143-3p m RNA level was significantly increased and SPRY3 m RNA level was decreased in MI group.Moreover,LOX and OPN protein levels were increased in MI specimens,and miR-143-3p and SPRY3 may be involved in cardiac remodeling after MI.2.In mice model,local collagen fibrosis and collagen cross-linking were significantly reduced in the antagomir-143-3p group compared with the myocardial infarction group.Downregulation of miR-143-3p may inhibit myocardial remodeling in mice.3.In vitro experiments confirmed that miR-143-3p mimics can enhance the transformation,migration and ECM crosslinking ability of HCFs,and promote the expression of LOX and OPN.4.Silencing SPRY3 can promote the expression of LOX and OPN,which in turn can promote collagen cross-linking and HCFS activation.5.Smads pathway is activated in myocardial infarction tissue and has been confirmed to be activated after regulation of miR-143-3p in vivo and in vitro,and the SMDAS pathway may be involved in the process of cardiac remodeling.6.Smads pathway was inhibited after SPRY3 silencing,and miR-143-3p may activate the Smads pathway by regulating SPRY3.Conclusion: MiR-143-3p activates Smads pathway through targeted regulation of SPRY3 to promote migration,transformation and ECM cross-linking ability of HCFs,and thus participate in the process of myocardial fibrosis and collagen cross-linking.