Human dental pulp stem cells improve left ventricular function, induce angiogenesis, and reduce infarct size in rats with acute myocardial infarction.

Human dental pulp contains precursor cells termed dental pulp stem cells (DPSC) that show self-renewal and multilineage differentiation and also secrete multiple proangiogenic and antiapoptotic factors. To examine whether these cells could have therapeutic potential in the repair of myocardial infarction (MI), DPSC were infected with a retrovirus encoding the green fluorescent protein (GFP) and expanded ex vivo. Seven days after induction of myocardial infarction by coronary artery ligation, 1.5 x 10(6) GFP-DPSC were injected intramyocardially in nude rats. At 4 weeks, cell-treated animals showed an improvement in cardiac function, observed by percentage changes in anterior wall thickening left ventricular fractional area change, in parallel with a reduction in infarct size. No histologic evidence was seen of GFP+ endothelial cells, smooth muscle cells, or cardiac muscle cells within the infarct. However, angiogenesis was increased relative to control-treated animals. Taken together, these data suggest that DPSC could provide a novel alternative cell population for cardiac repair, at least in the setting of acute MI.

Human platelet lysate enhances the proliferative activity of cultured human fibroblast-like cells from different tissues.

Several studies have shown the presence of fibroblast-like cells in the stromal fraction of different tissues with a high proliferative and differentiation potential. Platelet alpha granules contain growth factors released into the environment during activation. The effects of different supplements for culture medium (human serum, bovine serum and platelet lysate) on cultured human fibroblast-like cells from bone marrow, adipose tissue, trabecular bone and dental pulp have been compared. Expression of typical stromal and hematopoietic markers was analyzed and proliferative rates were determined. Flow cytofluorometry showed a homogenous pattern in serial-passaged cells, with a high level of stromal cell-associated markers (CD13, CD90, CD105). The presence of platelet lysate in culture media increased the number of cell generations obtained regardless of cell source. This effect was serum-dependent. Cell-based therapies can benefit by the use of products from human origin for "ex vivo" expansion of multipotent cells.