Zinc-induced effects on osteoclastogenesis involve activation of hyperpolarization-activated cyclic nucleotide modulated channels via changes in membrane potential
Zinc-induced effects on osteoclastogenesis involve activation of hyperpolarization-activated cyclic nucleotide modulated channels via changes in membrane potential
复制标题
锌诱导的破骨细胞生成作用涉及通过膜电位变化激活超极化激活的环核苷酸调节通道
DOI：
10.1002/jbmr.2507
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发表时间：
2015
期刊：
影响因子：
6.2
通讯作者：
Noda M and Skerry TM
中科院分区：
文献类型：
--
作者：
Notomi T;Kuno M;Ohura K;Noda M and Skerry TM
锌是哺乳动物体内的一种微量元素，越来越多的证据表明其在骨发育和破骨细胞生成中的关键作用。锌和电压门控离子通道之间的关系已被报道;然而，锌对膜电位和相关离子通道的影响仍然未知。在这项研究中，我们发现锌诱导的超极化在RAW 264.7细胞（RAW）中通过抑制超极化激活的环核苷酸调节通道（HCN）来促进。在RAW衍生的破骨细胞的电生理学实验中，HCN具有功能并产生超极化激活的内向电流（Ih），其性质与可兴奋细胞（如神经元和心肌细胞）中记录的Ih相似。HCN亚基HCN 1和HCN 4在RAW细胞中的定量PCR显示可检测水平的HCN 1 mRNA和HCN 4的表达是所有四个亚基中最高的。HCN 4敲低降低了骨密度Ih，并促进破骨细胞在锌的存在下，但不是在没有锌。为了确定膜超极化对破骨细胞生成的影响，我们通过稳定表达光驱动的外向质子泵Archaerhodopsin 3（Arch），在RAW细胞中开发了一种光可控膜电位系统。黄绿色光激活的拱使细胞膜超极化。在存在核因子κ B配体受体激活剂（RANKL）的情况下，光诱导超极化加速破骨细胞分化。因此，HCN活化减少了锌存在下破骨细胞分化的超极化相关促进作用。这项研究揭示了HCN和膜电位在非兴奋性破骨细胞中的新作用。© 2015美国骨与矿物质研究学会。
Zinc is a trace element in the mammalian body, and increasing evidence shows its critical role in bone development and osteoclastogenesis. The relationships between zinc and voltage‐gated ion channels have been reported; however, the effects of zinc on membrane potential and the related ion channels remain unknown. In this study, we found that zinc‐induced hyperpolarization in RAW264.7 cells (RAW) was promoted by inhibition of hyperpolarization‐activated cyclic nucleotide modulated channels (HCNs). In electrophysiological experiments with RAW‐derived osteoclasts, HCNs were functional and generated hyperpolarization‐activated inward currents (Ih) with properties similar to the Ih recorded in excitable cells such as neurons and cardiomyocytes. Quantitative PCR of HCN subunits HCN1 and HCN4 in RAW cells showed detectable levels of HCN1 mRNA and HCN4 expression was the highest of all four subunits. HCN4 knockdown decreased osteoclastic Ih and promoted osteoclastogenesis in the presence of zinc, but not in the absence of zinc. To determine the effect of membrane hyperpolarization on osteoclastogenesis, we developed a light‐controllable membrane potential system in RAW cells by stably expressing the light‐driven outward proton pump, Archaerhodopsin3 (Arch). Arch activation by yellow‐green light hyperpolarizes the cell membrane. Light‐induced hyperpolarization accelerated osteoclast differentiation in the presence of receptor activator of nuclear factor kappa‐B ligand (RANKL). Thus, HCN activation reduced the hyperpolarization‐related promotion of osteoclast differentiation in the presence of zinc. This study revealed the novel role of HCN and membrane potential in non‐excitable osteoclasts. © 2015 American Society for Bone and Mineral Research.