Roles and Mechanisms of TGR5 in the Modulation of CD4(+) T Cell Functions in Myocardial Infarction

摘要

Bile acid receptor TGR5 has been proved to play protective roles in the process of myocardial infarction (MI). Recently, we found spleen weight of Tgr5(+/+) mice was increased at 7-day post-MI but not in Tgr5(-/-) mice. Since the spleen is one of the main resources of immune and inflammatory cells post-MI, we conducted flow cytometry analysis of multiple immune cells in the heart post-MI. It showed the recruitment of CD4(+) T cells and CD8(+) T cells was continuously more in the heart of Tgr5(-/-) mice post-MI until 7 days after MI. Furthermore, CD4-specific TGR5 depletion mice exhibited aggravated ischemic injury. The mRNA expressions of the markers of Th1 and Treg were upregulated in the heart of Tgr5(-/-) mice at 7-day post-MI. These results suggested TGR5 modulates CD4(+) T cell functions and subsets distribution in the heart, and plays protective roles in myocardial infarction.