The Expression And Potential Role Of Corin In Atherosclerosis

BackgroundAtherosclerosis is the main pathological basis of cardiovascular diseases, such as coronary heart disease, myocardial infarction, stroke, and so on. It is a fundamental strategic measure to control the development of atherosclerosis in the prevention and treatment of cardiovascular diseases. To date, there are various hypotheses of pathogenesis in atherosclerosis and multiple genes are linked to its mechanism. Resulting from multiple risk factors, its pathogenesis is still not exactly clear. Further study the genes and their actions related to atherosclerosis will be helpful for us to take to prevent treat and control the disease in a more comprehensive and effective manner.Corin is a novel type II transmembrane serine protease, which is mainly expressed in the heart. It can activate atrial natriuretic peptide (ANP), which regulates blood pressure and cardiac function. Corin is involved in a variety of cardiovascular and pregnancy-related diseases. ANP exerts pronounced cardioprotective effects and vasoprotective actions. Corin gene mutation and dysfunction may lead to decreased activity, which may be related to a variety of cardiovascular diseases such as hypertension, cardiac hypertrophy and heart failure. However, whether corin is involved in atherosclerosis has not been reported. In light of our previous study, we found that the levels of corin in the plasma of patients with atherosclerosis were decreased, suggesting that corin may be involved in the procession of atherosclerosis.In this study, we established models of atherosclerosis in vitro and in vivo respectively, showed that corin expression in aortas, especially in endothelial cells.In this study, we hope to define the relationship between corin gene and atherosclerosis pathological process, to further expand our knowledge of corin biological activity and function characteristics. It is useful for us to understand the pathogenesis of atherosclerosis. And it may provide new target and idea for prevention and treatment of atherosclerosis-related diseases.Objectives1. Detect the expression of corin in the aorta and identify the expression and localization of corin in cells.2. Identify the association between corin and atherosclerosis.3. Preliminary discuss the potential role of corin in endothelial cells and cardiomyocytes in atherosclerosis respectively.Methods1. RT-PCR, immunohistochemistry and immunofluorescence staining analysis.Identify whether corin is expressed in aortas and endothelial cells its cell location.2. Animal models and groupsEstablish atherosclerotic animal models in vivo by feeding ApoE-/- mice on a high-fat diet(AS group). Give C57BL/6 mice on a normal diet as control group (WT group). Then we measured the expression changes of corin and its substrate-ANP by RT-qPCR, western blotting and immunohistochemistry in the aorta and heart in animal models of atherosclerosis, so as to identify the correlation of corin and atherosclerosis.3. Cell models and groupsCell model is established to and groups in vitro. We cultured human umbilical vein endothelial cells (HUVECs) line. First, to confirm corin is expressed in HUVECs by RT-PCR and immunohistochemistry, immunofluorescence. Then, HUVECs was incubated with ox-LDL at various concentrations for 24h, establishing the injury of endothelial cell models to imitate atherosclerosis. The expression levels of corin were measured by RT-qPCR and immunofluorescence technique. It is helpful to further confirm the association between corin and atherosclerosis..4. Were transfected with si-RNA and the wound healing scratch assayCorin-siRNA was transfected in endothelial cells and cardiomyocytes respectively in order to imitate the deficiency of corin in endothelial cells and cardiomyocytes. Then we measured the migration of endothelial cells to observed the effects on endothelial cell migration. The role and mechanism of corin in atherosclerosis in the two parts were preliminarily discussed in this study.Results1. Corin is expressed in aortas, especially in endothelial cells.2. The expression of corin-ANP pathway in aortas in atherosclerosis is increased in vivo, suggesting that corin may involve in atherosclerosis by activating ANP. Corin-ANP pathway in hearts has no changes compared with wild type group. It is unknown that whether the level of corin shedding into circulation exerts an action. So we design the further experiments to identify this point.3. The expression of corin in endothelial cells is upregulated after stimulated by ox-LDL in a dose-dependent manner in vitro.4. Corin was transfected by corin-siRNA in endothelial cells and cardiomyocytes inhibited migration of endothelial cells respectively in vitro. It is suggested that the expression of corin in endothelial cells and soluble corin synthetized by heart could involve in the pathological process of atherosclerosis by exerting an action on endothelial cells.ConclusionCorin was expressed in aorta, most likely in endothelial cells. Corin-ANP may be involved in atherosclerosis. Both endothelial and cardiac corin may exert protective effects in atherosclerosis through affecting endothelial function.