Expression and functional role of GTP binding proteins in bone marrow derived mesenchymal stem cells

Abstract

[한글]

[영문]Mesenchymal stem cells (MSCs) are shown to differentiate into cardiomyocyte under proper situation. However the molecular mechanisms underlying cardiomyogenic differentiation from MSCs remain poorly understood. Previous study reported that GTP binding proteins (G proteins) might play a critical role in general differentiation of MSCs and also an important role in cardiac differentiation of embryonic stem cells. Thus, our study aimed to investigate the expression and functional role of heterotrimeric and monomeric G proteins in MSCs. To evaluate the cardiac differentiation potential in cardiogenic cells (CGCs), three different cell groups, thus MSCs, cardiomyocytes (CMs), and CGCs from MSCs were analyzed. First of all, we investigated the expression level of heterotrimeric and monomeric G proteins in these three groups. As for the heterotrimeric G protein, expression level of Gq and Gs were similar in CMs and CGCs. In monomeric G proteins, RhoA and Rab1b were similarly expressed in CGCs compared with CMs. We also investigated intracellular signaling pathways related to G proteins, especially in α-, β-adrenergic receptor related signaling. α-adrenergic receptor and Gq related Rho signaling and subsequently ERK 1/2 signaling were confirmed in CGCs as well as in CMs. β-adrenergic receptor and Gs related Rab signaling and further downstream ERK 1/2 signaling were also confirmed in CGCs and CMs. In conclusion, CGCs and CMs showed similar G protein expression and function in α-, β-adrenergic receptor related signaling. Our results showed that G proteins may play important roles in cardiac differentiation of MSCs.