Transient receptor potential melastatin 4 channel controls calcium signals and dental follicle stem cell differentiation.
Transient receptor potential melastatin 4 channel controls calcium signals and dental follicle stem cell differentiation.
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DOI：
10.1002/stem.1264
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发表时间：
2013-01
期刊：
影响因子：
--
通讯作者：
Cheng H
中科院分区：
文献类型：
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作者：
Nelson P;Ngoc Tran TD;Zhang H;Zolochevska O;Figueiredo M;Feng JM;Gutierrez DL;Xiao R;Yao S;Penn A;Yang LJ;Cheng H
细胞内 Ca2+ 浓度升高是干细胞分化过程中常见的现象，但在该过程完成后停止。瞬时受体电位褪黑素 4 (TRPM4) 是一种控制可兴奋和非兴奋细胞中 Ca2+ 信号的离子通道。然而，它在干细胞中的作用仍然未知。本研究的目的是表征大鼠牙囊干细胞 (DFSC) 中的 TRPM4，并确定其对 Ca2+ 信号传导和分化过程的影响。我们在 DFSC 中发现了 TRPM4 基因表达，但没有发现 TRPM5，这是一个具有相似功能的密切相关通道。用增加的缓冲 Ca2+ 灌注细胞会导致 TRPM4 典型电流的浓度依赖性激活，该电流也是电压依赖性的并具有 Na+ 电导率。 shRNA 的分子抑制会降低成骨过程中的通道活性和细胞增殖，但不会降低脂肪生成过程中的通道活性和细胞增殖。结果，尽管 DFSC 未能分化为脂肪细胞，但在成骨细胞形成过程中观察到矿化和碱性磷酸酶活性增强。此外，正常的激动剂诱导的第一阶段和第二阶段的 Ca2+ 信号转化为逐渐且持续的增加，这证实了通道控制 Ca2+ 信号传导的能力。利用全基因组微阵列分析，我们鉴定了 DFSC 分化过程中受 TRPM4 影响的几个基因。这些发现表明 TRPM4 对骨生成具有抑制作用，而它似乎是脂肪生成所必需的。这些数据还提供了干细胞分化过程中 Ca2+ 信号传导模式与基因表达之间的潜在联系。
Elevations in the intracellular Ca2+ concentration are a phenomena commonly observed during stem cell differentiation but cease after the process is complete. The Transient Receptor Potential Melastatin 4 (TRPM4) is an ion channel that controls Ca2+ signals in excitable and non-excitable cells. However, its role in stem cells remains unknown. The aim of this study was to characterize TRPM4 in rat dental follicle stem cells (DFSCs) and to determine its impact on Ca2+ signaling and the differentiation process. We identified TRPM4 gene expression in DFSCs, but not TRPM5, a closely related channel with similar function. Perfusion of cells with increasing buffered Ca2+ resulted in a concentration-dependent activation of currents typical for TRPM4, which were also voltage-dependent and had Na+ conductivity. Molecular suppression with shRNA decreased channel activity and cell proliferation during osteogenesis, but not adipogenesis. As a result, enhanced mineralization and alkaline phosphatase enzyme activity were observed during osteoblast formation, although DFSCs failed to differentiate into adipocytes. Furthermore, the normal agonist-induced first and secondary phases of Ca2+ signals were transformed into a gradual and sustained increase which confirmed the channels’ ability to control Ca2+ signaling. Using whole genome microarray analysis, we identified several genes impacted by TRPM4 during DFSC differentiation. These findings suggest an inhibitory role for TRPM4 on osteogenesis while it appears to be required for adipogenesis. The data also provide a potential link between the Ca2+ signaling pattern and gene expression during stem cell differentiation.