The Correlation Research Of α-enolase In Acute Rejection Of Cardiac Transplant In Rat Model

Objective Acute allograft rejection remains a major problem in solid organ transplantation. The enzyme α-enolase has been shown to induce an immune response in cardiac transplantation [1,2]. In this study, we investigated the role of α-enolase in acute allograft rejection in a rat model of heart transplantation.Methods Hearts from either Wistar-Furth(WF: RT1u) or Lewis(Lew: RT11) rats were transplanted into Lewis(Lew: RT11)rats. We performed Western Blot of heart tissues on day 1, 3, 5,and 7 after cardiac transplantation. To analyze α-enolase express between the isografts and allografts for Immunohistochemical staining. 3,5,7 days after heart transplantation for related cytokines CD4 and IL-17 for immunohistochemical.We used double immunofluorescent staining on transverse cryosections of graft tissues by co-labeling with different markers, including those forα-enolase, CD4+ T cells, and IL-17.Results No rejection occurred in the isograft group, for which the median survival time was >168 days, whereas the median survival time of the allograft group was significantly less at 10±2.1days(n=8 per group, P<0.001). Increased inflammation wasobserved in allografts, including increased α-enolase expression and increased numbers of infiltrating CD4+ T cells(P<0.05). By immunohistochemical staining, we confirmed that α-enolase was not only expressed in myocardial cells but also in the infiltrating lymphocytes. However, on the 5th day after transplantation,α-enolase expression was no longer observed in the lymphocytes(n=3, P<0.001). In contrast, no lymphocytes were found in isografts after transplantation(n=3, P<0.001). On the 5th day after transplantation, enhanced α-enolase immunocompetence was found in allografts. Simultaneously, we observed co-localization ofα-enolase and CD4. we performed CD4 and IL-17 labeling, which confirmed the existence of co-localized CD4 and IL-17 and performed α-enolase and IL-17 labeling, which confirmed the existence of co-localized α-enolase and IL-17. On the 5th day after transplantation, CD4 and IL-17 expression were not found in isografts.Conclusions α-enolase expression is increase in lymphocytes,which are implicated in the acute rejection of cardiac transplants.α-enolase might play an important role in acute transplant rejection via the differentiation of CD4+ T cells into Th17 cells, thereby allowing IL17 to promote acute rejection.