Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana 70803, USA.
Stem Cells Dev. 2010 Sep;19(9):1393-403. doi: 10.1089/scd.2009.0262.
The transient receptor potential melastatin type 7 channel (TRPM7) is a member of the TRP family of ion channels that is essential for cell proliferation and viability. Mesenchymal stem cells (MSCs) from bone marrow are a potential source for tissue repair due to their ability to differentiate into specialized cells. However, the role of TRPM7 in stem cells is unknown. In this study, we characterized TRPM7 in mouse MSCs using molecular biology, immunocytochemistry, and patch clamp. We also investigated TRPM7 function using a lentiviral vector and specific shRNA to knockdown gene expression. By RT-PCR and immunocytochemistry, we identified TRPM7, but not TRPM6, a close family member with similar function. Electrophysiological recordings during depletion of intracellular Mg(2+) or Mg(2+)-ATP resulted in the development of currents typical for the channel. Furthermore, 2-aminoethoxydiphenyl borate (1 pM-100 microM) inhibited TRPM7 in a concentration-dependent manner. The molecular suppression of TRPM7 significantly decreased MSC proliferation and viability as determined by MTT assay. In addition, TRPM7 gene expression was up-regulated during osteogenesis. These findings demonstrate that TRPM7 is required for MSC survival and perhaps involved in the differentiation process.
瞬时受体电位 melastatin 型 7 通道（TRPM7）是 TRP 家族离子通道的成员，对于细胞增殖和存活至关重要。骨髓间充质干细胞（MSCs）由于能够分化为专门的细胞，因此是组织修复的潜在来源。然而，TRPM7 在干细胞中的作用尚不清楚。在这项研究中，我们使用分子生物学、免疫细胞化学和膜片钳技术对小鼠 MSCs 中的 TRPM7 进行了表征。我们还使用慢病毒载体和特定的 shRNA 来敲低基因表达，研究了 TRPM7 的功能。通过 RT-PCR 和免疫细胞化学，我们鉴定了 TRPM7，但不是具有相似功能的密切相关家族成员 TRPM6。在耗尽细胞内 Mg（2+）或 Mg（2+）-ATP 期间进行的电生理记录导致出现典型的通道电流。此外，2-氨基乙氧基二苯硼酸盐（1 pM-100 microM）以浓度依赖性方式抑制 TRPM7。TRPM7 的分子抑制显著降低了 MTT 测定法确定的 MSC 增殖和活力。此外，TRPM7 基因表达在成骨过程中上调。这些发现表明，TRPM7 是 MSC 存活所必需的，并且可能参与分化过程。
