Investigation of the physiological functions of anion channels during the differentiation in stem cells.

我们研究了小鼠胚胎干细胞（mES）和人骨髓间充质干细胞（hMSCs）在向心肌细胞或脂肪细胞分化过程中阴离子通道的生理功能。RT-PCR检测未分化mES细胞和hMSCs中ClC-3、ClC-4和Bestrophin mRNA的表达。在膜片钳实验中，可以记录到Ca^<2+>激活的向外K^+电流（I_<KCa>），但Ca^<2+>激活的氯离子电流太小，无法分析。在低渗溶液中可以记录到体积敏感的Cl电流。我们得出结论，阴离子通道存在于mES细胞和hMSCs中，并且由ClC-3编码的Cl电流在未分化的hMSCs中起作用。我们之前已经证明了Cai在hMSCS中的振荡（2003、2004、2005,Cell Calcium），因此，我们假设Cai可能会影响分化过程。当在培养基中添加Ca通道阻滞剂时，脂肪化受到抑制，表明Cai参与了间充质干细胞向脂肪化的分化过程。

We investigated the physiological functions of anion channels in mouse embryonic stem cells (mES) and human bone marrow-derived mesenchymal stem cells (hMSCs) during the differentiation to cardiac myocytes or adiposities. Using RT-PCR, the expression of mRNA for ClC-3, ClC-4 and Bestrophin could be detected in both undifferentiated mES cells and hMSCs. In the patch clamp experiments, Ca^<2+> activated outward K^+ currents (I_<KCa>) could be recorded, however, Ca^<2+> activated chloride currents were too small to analyze. Volume sensitive Cl currents were could be recorded in the hypotonic solutions. We concluded that anion channels exist in mES cells and hMSCs and Cl currents coded by ClC-3 have a function in undifferentiated hMSCs. We have demonstrated Cai oscillations in hMSCS previously (2003, 2004, 2005, in Cell Calcium), therefore, we hypothesize that Cai might affect the differentiation processes. When Ca channel blockers were added in the culture medium, adiposeness were inhibited, indicating the contribution of Cai to the differentiating processes from mesenchymal stem cell to adiposities.