Factors for C-Kit Expression in Cardiac Outgrowth Cells and Human Heart Tissue

We determined the factors associated with the expression of c-kit in the heart and the proliferation of c-kit-positive (c-kit^pos) cardiac stem cells among the outgrowth cells cultured from human cardiac explants.Samples of the right atrium (RA), left atrium (LA), and left ventricle obtained from patients during open-heart surgery were processed for cell culture of outgrowth cells and tissue analysis. The total number of growing cells and the population of c-kit^pos cells were measured and compared with c-kit expression in native tissues and characteristics of the patients according to the region of the heart.We analyzed 452 samples from 334 patients. Atrial fibrillation (AF) in the patients reduced the number of outgrowth cells from the RA and LA, and aging was a co-factor for the LA. The c-kit^pos population from the RA was associated with serum brain natriuretic peptide (BNP). C-kit expression in native tissue was also associated with BNP expression. However, we observed no relationship in expression between outgrowth cells and native tissue. In addition, the RA tissue provided the highest number of c-kit^pos cells, and the left ventricle provided the lowest.C-kit was weakly expressed in response to damage. In addition, no correlation between outgrowth cells and native tissue was found for c-kit expression.