Injured cardiomyocytes promote dental pulp mesenchymal stem cell homing

Abstract

Background: The heart is unable to regenerate its tissues after severe injuries. Stem cell therapy appears to be one of the most promising approaches, though preclinical results are hitherto contradictory and clinical trials scanty and/or limited to phase-I. The limited knowledge about stem cell early homing in infarcted cardiac tissues can concur to this scenario.

Methods: The stem cell migration was assessed in in-vitro and ex-vivo models of heart ischemia, employing a rat dental pulp stem cell line (MUR-1) that shares the same ontogenic progenitors with portions of the heart, expresses markers typical of cardiac/vascular-like progenitors and is able to differentiate into cardiomyocytes in-vitro.

Results: Here, we demonstrated that the MUR-1 can reach the injured cells/tissue and make contacts with the damaged cardiomyocytes, likely through Connexin 43, N-cadherin and von Willebrand Factor mediated cell-cell interactions, both in in-vitro and ex-vivo models. Furthermore, we found that SDF-1, FGF-2 and HGF, but not VEGF are involved as chemotactic factors in MUR-1 migration, notifying a similarity with neural crest cell behavior during the organogenesis of both the splanchnocranium and the heart.

Conclusions: Herein we found a similarity between what happens during the heart organogenesis and the early migration and homing of MUR-1 cells in ischemic models.

General significance: The comprehension of molecular aspects underlying the early phases of stem cell migration and interaction with damaged organ contributes to the future achievement of the coveted stem cell-mediated organ regeneration and function preservation in-vivo.

Keywords: Cardiac ischemia; Cell migration; Dental pulp stem cell; Hypoxic cardiomyocyte.