Functional roles and regulatory mechanisms of voltage-gated proton channels

电压门控质子通道的功能作用和调节机制

• 批准号: 10670047
• 负责人: KUNO Miyuki
• 金额: $ 1.73万
• 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: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10670047/
• 关键词: proton channels; proton signals; pH regulation; temperature dependency; microglia; mast cells; osteoclasts; cell swelling; アシドーシス; 細胞膨化; 温度依存性

Voltage-gated proton (HィイD1+ィエD1) channels are unique mechanisms to exclude a massive amount of HィイD1+ィエD1 from the inside of cells, and are considered to contribute to a rapid regulation of intracellular pH. We studied expression and regulatory mechanisms of the HィイD1+ィエD1 currents in cells with different functions, such as, bone marrow-derived mast cells (BMMC), rat spinal microglia and murine osteoclasts. Recently high sensitivity to temperature has been found to be a common feature of HィイD1+ィエD1 currents in many types of cells. In both BMMC and microglia, the amplitude of steady-state currents, the activation delay, and the activation rate depended greatly on temperature between 22 and 36℃. The half activation voltage was shifted to more negative potentials by heating in both cells. The temperature set-point for the current activation was higher in BMMC possibly due to its intrinsic gating properties or modulatory mechanisms. More than 90% of round/amoeboid microglia expressed HィイD … More 1+ィエD1 currents. The HィイD1+ィエD1 currents were increased in association with cell swelling induced by intracellular dialysis with acidic pipette solutions (pH 5.5-6.8). The acidosis-induced cell swelling and the accompanying potentiation of the HィイD1+ィエD1 currents required non-hydrolytic actions of intracellular ATP and were inhibited by agents affecting actin filaments (phalloidin and cytochalasin D), as the hypotonically-activated ClィイD1-ィエD1 channel in osteoclasts. These findings suggest that cell swelling induced by either intracellular acidification or osmotic imbalance is a crucial signal to increase the HィイD1+ィエD1 currents of microglia. The swelling-mediated regulation of the HィイD1+ィエD1 channel might operate as a negative feedback mechanism to protect microglia from cytotoxic acidification and swelling in the pathological CNS. These results suggest that activities of the HィイD1+ィエD1 channels are regulated in relation to their functional states and phenotypes and are involved in the various pathophysiolocal effects. Less

电压门控质子（H β D1+ H β D1）通道是将大量的H β D1+ H β D1从细胞内排出的独特机制，并且被认为有助于细胞内pH的快速调节。我们研究了H β D1+ H β D1电流在具有不同功能的细胞中的表达和调节机制，例如，骨髓源性肥大细胞（BMMC），大鼠脊髓小胶质细胞和小鼠破骨细胞。最近发现，对温度的高度敏感性是许多类型细胞中H_（10）D_1 + H_（10）D_1电流的共同特征。在22 ~ 36℃温度范围内，BMMC和小胶质细胞的稳态电流幅度、激活延迟和激活速率均显著依赖于温度。通过在两个电池中加热，半活化电压被转移到更负的电位。BMMC中电流激活的温度设定点较高，可能是由于其内在的门控特性或调节机制。90%以上的圆形/变形虫样小胶质细胞表达H β D ...更多信息 1+直流D1电流。HイD1+ D1电流增加与酸性移液器溶液（pH 5.5-6.8）细胞内透析诱导的细胞肿胀相关。酸中毒诱导的细胞肿胀和伴随的增强H β D1+ H β D1电流需要细胞内ATP的非水解作用，并被影响肌动蛋白丝的药物（鬼笔环肽和细胞松弛素D）抑制，如破骨细胞中低渗激活的Cl β D1-Cl β D1通道。这些结果表明，细胞内酸化或渗透压失衡引起的细胞肿胀是增加小胶质细胞H β D1+ H β D1电流的关键信号。肿胀介导的调节H β D1+ H β D1通道可能作为一种负反馈机制，以保护小胶质细胞免受病理性CNS中的细胞毒性酸化和肿胀。这些结果表明，H β D1+ H β D1通道的活动与其功能状态和表型有关，并参与各种病理生理局部效应。少

项目成果

Sakai, H. et al.: "Synergetic activation of outwardly rectifying Cl^- currents by hypotonic stress and external Ca^<2+> in murine osteoclasts"J. physiol. 515. 157-168 (1999)

Sakai，H.等人：“在小鼠破骨细胞中通过低渗应激和外部Ca ^ 2 协同激活向外整流的Cl ^ -电流”J。

Sakai, H. et al.: "Co-operative action of hypotonic stress and a rise in external Ca^<2+> on Cl^- currnets of murine osteoclasts"Excerpta Medica Internation, Congress Series. (in press).

Sakai，H.等人：“低渗应激和外部Ca ^ 2 增加对小鼠破骨细胞Cl 2 -电流的协同作用”国际医学摘录，国会系列。

久野みゆき 他: "膜電位依存性プロトン(H^+)チャネルの温度依存性の解析" 第76回生理学会大会. 発表予定.

Miyuki Kuno 等人：“膜电位门控质子 (H^+) 通道的温度依赖性分析”第 76 届日本生理学会大会演讲。

Kuno, M. et al.: "Behaviors of voltage-gated proton channels at different temperature in mast cells and microglia"Biophysical j. (Abstract). 78. 2072 (2000)

Kuno, M. 等人：“肥大细胞和小胶质细胞中不同温度下电压门控质子通道的行为”Biophysical j。

Sakai, H. et al.: "Co-operative action of hypotonic stress and a rise in external CaィイD12+ィエD1 on ClィイD1-ィエD1 currents of murine osteoclasts"Excerpta Media Internation Congress Series. in press.

Sakai, H. 等人：“低渗应激和外部 CaD12+D1 升高对小鼠破骨细胞 ClaiD1-D1 电流的协同作用”摘录媒体国际大会系列。