Towards a pragmatic strategy for regenerating infarcted myocardium with glandular stem cells

Summary We have recently reported that the in vitro differentiation of human glandular stem cells into cardiac-like cells can be enhanced by co-culture with small myocardial biopsies. These results suggest that implantation of such cells directly into infarcted myocardium may facilitate the regeneration of the heart. As a preliminary to testing this approach in a goat model, pilot in vitro tests for these experiments have been performed and are presented here. Stem cells, isolated from the glandula submandibularis of Boer goats (SuSCs), have been co-cultured either directly or indirectly with heart biopsies from various species (Boer goat, rattus norwegicus, human) or heart conditioned medium for 48 h. We found a substantial increase in the number of cells expressing heart-specific marker proteins (Troponin I, Troponin T, sarcomeric myosin) regardless of the source organism of the heart biopsy. The proliferation of SuSCs also increased significantly under co-culture conditions. To benefit from these results in vivo , the stem cells must be delivered to the infarcted region in the heart and held securely in place over lengthy periods of time. Therefore, we repeated the co-culture experiments with SuSCs grown on biodegradable Vicryl ® -meshes. The cells demonstrated good proliferation on the meshes and likewise, the expression of heart-specific marker proteins could be enhanced through co-culture with heart biopsies.