Rat mesenchymal cell CD44 surface markers: Role in cardiomyogenic differentiation

We reported that hyaluronic acid (HA) containing silk fibroin (SF) patches markedly improved cardiomyogenic differentiation of 5-aza inducing rat mesenchymal stem cells (rMSCs). It is well known that MSCs contain an abundant of CD44 surface markers, and HA is the receptor of those markers. Examining the roles of CD44 markers on cardiomyogenic differentiation of rMSCs might help to design new cardiac patches for cell therapy in infarcted hearts. To study the issue, 5-aza inducing rMSCs with or without a CD44-blockage treatment was cultured in SF/HA cardiac patches; the expressions of cardiac genes and specific cardiac proteins as an index of cardiomyogenic differentiation were examined in the end of the cultivation. It was found that the expressions of cardiac genes such as Gata4 and Nkx2.5 and proteins such as cardiotin and connexion 43, and were significantly decreased for the rMSCs with a CD44-blockage treatment.We conclude that the surface markers of CD44 of rMSCs highly modulate the cardiomyogenic differentiation of the cells when they are cultivated on SF/HA cardiac patches.