Proton signaling mediated by voltagegated proton channels

由电压门控质子通道介导的质子信号传导

• 批准号: 14570045
• 负责人: KUNO Miyuki
• 金额: $ 2.18万
• 依托单位: Osaka City University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14570045/
• 关键词: proton channel; temperature dependence; osteoclast; cell swelling; pH regulation; proton sensor; phorbol ester; microglia; プロトンシグナル; 酸感受性

We have investigated how the voltage-gated proton (H^+) channels regulate H^+ signaling in osteoclasts, microglia and bone-marrow-derived mast cells (BMMC). The Q_<10> value was > 2.0 for conductance and 3 -6 for gating parameters. These high Q_<10> values were preserved well in both microglia and BMMC, which differed in the expression rate of the channel, implying that the high temperature dependence resides in the channel itself. The Q_<10> value for the conductance was, however, often decreased at high temperature or in swollen cells, thus, indicating that the activation status of the H^+ channel is heterogeneous. To clarify actions of the H^+ channel in intact cells, the channel activity in response to various types of cell acidosis was examined in the perforated-whole cell recordings under intrinsic pH buffers. In osteoclasts, an activator for protein kinase C, PMA, induced cell acidosis and activation of the H^+ channel. The reversal potential was served as a real-time monitor for changes in cellular pH in clamped cells. In microglia, the H^+ channel was activated accompanying either acute or prolonged cell acidosis. The channel activation terminated upon removal of the acidosis due to the H^+ extrusion. A part of the activation was, however, modified by ΔpH-independent processes. In addition, sometimes increases in intracellular Ca^<2+> or flux of CL^-, a counter ion for H^+, were associated with the acidosis. Thus H^+ signaling is intimately related to synergistic actions of other ion signals. This study has provided evidences that the H^+ can maintain cellular pH homeostasis by sensing minor changes in pH disturbances and, simultaneously, would trigger H^+ to the surrounding cells.

我们研究了电压门控质子（H^+）通道如何调节破骨细胞、小胶质细胞和骨髓源性肥大细胞（BMMC）中的H^+信号。电导的Q_<10>值&gt; 2.0，门控参数的Q_值为3 - 6。这些高Q<10>值在小胶质细胞和BMMC中均得到很好的保持，这表明通道的高温度依赖性存在于通道本身。然而<10>，电导的Q值在高温或肿胀的细胞中经常降低，因此，表明H^+通道的激活状态是不均匀的。为了阐明H^+通道在完整细胞中的作用，我们在内源性pH缓冲液中，通过穿孔全细胞记录，检测了响应于各种类型细胞酸中毒的通道活性。在破骨细胞中，蛋白激酶C激活剂PMA可诱导细胞酸中毒和H^+通道激活。逆转电位作为一个实时监测细胞pH值的变化，在夹紧的细胞。在小胶质细胞中，H^+通道被激活，伴随着急性或长期的细胞酸中毒。由于H^+排出，酸中毒消除后，通道激活终止。然而，一部分活化被Δ pH非依赖性过程修饰。此外，有时细胞内Ca^2+或CL^-（H^+的抗衡离子）流量的增加也与酸中毒有关。因此，H^+信号与其他离子信号的协同作用密切相关。本研究提供的证据表明，H^+可以通过感知pH扰动的微小变化来维持细胞内pH的稳态，同时也会将H^+触发到周围的细胞。

项目成果

森泰生, 稲垣千代子, 久野みゆき, 井上隆司, 岡田泰伸, 今泉祐治: "薬理学のQOLへの貢献2:細胞増殖・分化・死を制御するイオンメカニズムと創薬"Folia Pharmacol.Jpn.. 122. 201-214 (2003)

Yasuo Mori、Chiyoko Inagaki、Miyuki Kuno、Takashi Inoue、Yasunobu Okada、Yuji Imaizumi：“药理学对 QOL 2 的贡献：控制细胞增殖、分化和死亡的离子机制和药物发现” Folia Pharmacol.Jpn.. 122 .201 -214 (2003)

Morihata, H., Mori, H., Sakai, H., Kawawaki, J., sawada, M., Tsutada, T., Kuno, M.: "Activation of voltage-gated proton channels and calcium mobilization upon acute and prolonged cell acidosis in rat micorogilia"Biophys.J.. 86. 129a (2004)

Morihata, H.、Mori, H.、Sakai, H.、Kawawaki, J.、sawada, M.、Tsutada, T.、Kuno, M.：“电压门控质子通道的激活和急性和长时间的钙动员

Shimakawa, S., Suzuki, S., Miyamoto, R., Takitani, K., Tanaka, K., Tanabe, T., Wakamiya, E., Nakamura, F., Kuno, M., Matsuura, S., Watanabe, Y., Tamai, H.: "Neuropilin-2 is overexpresed in the rat brain after limbic seizures."Brain Res.. 956. 67-73 (2002)

岛川，S.，铃木，S.，宫本，R.，泷谷，K.，田中，K.，田边，T.，若宫，E.，中村，F.，久野，M.，松浦，S.，

Mori, H., Sakai, H., Morihata, H., Yamano, T., Kuno, M.: "A voltage-gated H^+ channel is a powerful mechanism for pH homeostasis in murine steoclasts"Kobe J Med Sci. 48. 87-96 (2002)

Mori, H.、Sakai, H.、Morihata, H.、Yamano, T.、Kuno, M.：“电压门控 H^ 通道是小鼠破骨细胞 pH 稳态的强大机制”Kobe J Med Sci。

Kuno, M., Morihata, H., Mori H., Kawawaki, J.: "Effects of temperature on the voltage-gated proton channels and proton signaling"Jpn.J.Physiol.. Vol.52,Suppl.. S117 (2002)

Kuno, M.、Morihata, H.、Mori H.、Kawawaki, J.：“温度对电压门控质子通道和质子信号传导的影响”Jpn.J.Physiol.. Vol.52，Suppl.. S117（