Abstract
Overactive inflammatory responses contribute to progressive cardiac dysfunction after myocardial infarction (MI). Mesenchymal stem cell (MSC) has generated significant interest as potent immune modulators that can regulate excessive immune responses. We hypothesized that intravenous (iv) administration of human umbilical cord-derived MSC (HucMSC) exerts systemic and local anti-inflammation effects, leading to improved heart function after MI. In murine MI models, we confirmed that single iv administration of HucMSC (30 × 104) improved cardiac performance and prevented adverse remodeling after MI. A small proportion of HucMSC is trafficked to the heart, preferentially in the infarcted region. HucMSC administration increased CD3+ T cell proportion in the periphery while decreased T cell proportion in both infarcted heart and mediastinal lymph nodes (med-LN) at 7-day post-MI, indicating a systematic and local T cell interchange mediated by HucMSC. The inhibitory effects of HucMSC on T cell infiltration in the infarcted heart and med-LN sustained to 21-day post-MI. Our findings suggested that iv administration of HucMSC fostered systemic and local immunomodulatory effects that contributed to the improvement of cardiac performance after MI.