OBJECTIVE: We aimed to investigate the role of mShox2 in generating If pacemaker current in vitro by means of electric-pulse current stimulation (EPCS) of canine mesenchymal stem cells (cMSCs). METHODS: mShox2 genetically modified cMSCs were prepared with pLentis-mShox2 red fluorescent protein. After EPCS induction, we examined the kinetic characteristics of generated inward current by means of a patch clamp. We then evaluated the expression of pacemaker-related genes, such as Nkx2.5, Tbx3, HCN4, Cx43 and Cx45, by means of qRT-PCR and Western blotting. The morphological changes and the cardiomyogenic differentiation marker cTnT were investigated at the same time. RESULTS: The time- and voltage-dependent inward current recorded after mShox2 infection was confirmed to be If current. After EPCS induction, the detection rate of this If current was increased. The current amplitude and density were increased, and the channel activation curve shifted to the right. The pacemaker markers Tbx3, HCN4 and Cx45 were significantly upregulated, but the working myocardium markers Nkx2.5 and Cx43 were downregulated after mShox2 infection, and were more remarkable after EPCS induction. The cells became larger and assumed spindle and spider-like morphologies. cTnT was also detected in the experimental cells. CONCLUSIONS: Our results suggest that EPCS promotes the differentiation of mShox2 genetically modified cMSCs into pacemaker-like cells, which generates more If current.
OBJECTIVE: We aimed to investigate the role of mShox2 in generating If pacemaker current in vitro by means of electric-pulse current stimulation (EPCS) of canine mesenchymal stem cells (cMSCs). METHODS:mShox2 genetically modified cMSCs were prepared with pLentis-mShox2 red fluorescent protein. After EPCS induction, we examined the kinetic characteristics of generated inward current by means of a patch clamp. We then evaluated the expression of pacemaker-related genes, such as Nkx2.5, Tbx3, HCN4, Cx43 and Cx45, by means of qRT-PCR and Western blotting. The morphological changes and the cardiomyogenic differentiation marker cTnT were investigated at the same time. RESULTS: The time- and voltage-dependent inward current recorded after mShox2 infection was confirmed to be If current. After EPCS induction, the detection rate of this If current was increased. The current amplitude and density were increased, and the channel activation curve shifted to the right. The pacemaker markers Tbx3, HCN4 and Cx45 were significantly upregulated, but the working myocardium markers Nkx2.5 and Cx43 were downregulated after mShox2 infection, and were more remarkable after EPCS induction. The cells became larger and assumed spindle and spider-like morphologies. cTnT was also detected in the experimental cells. CONCLUSIONS: Our results suggest that EPCS promotes the differentiation of mShox2 genetically modified cMSCs into pacemaker-like cells, which generates more If current.