Analysis Of Molecular Mechanisms By Which NINJ2 Causes Atherosclerosis

Atherosclerosis is the primary cause of cardiovascular diseases such as coronary artery disease(CAD) and stroke, both of which are the leading causes of about 29% of all deaths per year worldwide. Many AS susceptibility loci and genes have been found by genome-wide association studies(GWAS) since 2007, however, their genetic and molecular mechanisms in the pathogenesis of AS are still unclear. In 2009, a GWAS revealed a new gene, NINJ2 located on chromosome 12p13, which was significantly associated with risk of stroke. But to date, there has been little research about NINJ2 function, especially about how it affects the AS pathogenesis. Thus, we initiated this study to explore the molecular mechanism of NINJ2 in atherogenesis.In this thesis project, the protein prediction and subcellular localization experiments showed that Ninjurin2 is a two-transmembrane domain protein. According to the cell adhesion study, under a condition of the knockdown of NINJ2, the adhesion between THP-1 and HUVEC was significantly attenuated, which indicates that Ninjurin2 may affect the adhesion between leukocyte and endothelial cell as a adhesion molecule. To explore the potential target genes of NINJ2, atherosclerosis antibody assays and chemokine antibody assays were performed when NINJ2 was knocked down. Many potential downstream genes were identified and found to be influenced by NINJ2. We then performed qPCR analysis to validate that the down-regulation of NINJ2 decreased the expression of genes which were involved in the recruitment, migration and adhesion of leukocytes in the inflammation process. This suggests that NINJ2 plays a potential role in the inflammatory reaction by regulating the related genes. Furthermore, we performed the pull-down assay to identify proteins that interact with Ninjurin2, but failed to find the interacting proteins. More extensive studies are needed.In summary, we have found that NINJ2 could significantly influence the adhesion progress of leukocytes as well as regulating the genes related to inflammation. The results indicate that NINJ2 plays an impotent role in the progress of antherogenesis by affecting the adhesion between leukocytes and vascular endothelial in inflammation.