Shen Bing, Wong Ching-On, Lau On-Chai, Woo Theodosia, Bai Suwen, Huang Yu, Yao Xiaoqiang
School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Shatin, Hong Kong, China; Department of Physiology, Anhui Medical University, Hefei, China.
School of Biomedical Sciences, Faculty of Medicine, the Chinese University of Hong Kong, Shatin, Hong Kong, China.
PLoS One. 2015 Apr 7;10(4):e0122227. doi: 10.1371/journal.pone.0122227. eCollection 2015.
Mechanical forces exerted on cells impose stress on the plasma membrane. Cells sense this stress and elicit a mechanoelectric transduction cascade that initiates compensatory mechanisms. Mechanosensitive ion channels in the plasma membrane are responsible for transducing the mechanical signals to electrical signals. However, the mechanisms underlying channel activation in response to mechanical stress remain incompletely understood. Transient Receptor Potential (TRP) channels serve essential functions in several sensory modalities. These channels can also participate in mechanotransduction by either being autonomously sensitive to mechanical perturbation or by coupling to other mechanosensory components of the cell. Here, we investigated the response of a TRP family member, TRPC5, to mechanical stress. Hypoosmolarity triggers Ca2+ influx and cationic conductance through TRPC5. Importantly, for the first time we were able to record the stretch-activated TRPC5 current at single-channel level. The activation threshold for TRPC5 was found to be 240 mOsm for hypoosmotic stress and between -20 and -40 mmHg for pressure applied to membrane patch. In addition, we found that disruption of actin filaments suppresses TRPC5 response to hypoosmotic stress and patch pipette pressure, but does not prevent the activation of TRPC5 by stretch-independent mechanisms, indicating that actin cytoskeleton is an essential transduction component that confers mechanosensitivity to TRPC5. In summary, our findings establish that TRPC5 can be activated at the single-channel level when mechanical stress on the cell reaches a certain threshold.
施加于细胞的机械力会对质膜施加压力。细胞感知这种压力并引发机械电转导级联反应,从而启动补偿机制。质膜中的机械敏感离子通道负责将机械信号转换为电信号。然而,机械应力响应下通道激活的潜在机制仍未完全了解。瞬时受体电位(TRP)通道在多种感觉模式中发挥重要作用。这些通道还可以通过自主对机械扰动敏感或与细胞的其他机械感觉成分偶联来参与机械转导。在此,我们研究了TRP家族成员TRPC5对机械应力的反应。低渗会触发Ca2+内流以及通过TRPC5的阳离子电导。重要的是,我们首次能够在单通道水平记录拉伸激活的TRPC5电流。发现TRPC5对低渗应激的激活阈值为240 mOsm,对施加于膜片的压力的激活阈值在-20至-40 mmHg之间。此外,我们发现肌动蛋白丝的破坏会抑制TRPC5对低渗应激和膜片移液器压力的反应,但不会阻止通过非拉伸依赖机制激活TRPC5,这表明肌动蛋白细胞骨架是赋予TRPC5机械敏感性的重要转导成分。总之,我们的研究结果表明,当细胞上的机械应力达到一定阈值时,TRPC5可以在单通道水平被激活。
PLoS One. 2015-4-7
J Physiol. 2008-12-1
Methods Enzymol. 2007
J Neuroinflammation. 2024-12-18
Expert Rev Respir Med. 2023
Front Neurosci. 2023-6-7
Front Physiol. 2022-11-10
Front Cell Dev Biol. 2022-9-7
Elife. 2022-9-2
Physiol Rev. 2023-1-1
Am J Physiol Gastrointest Liver Physiol. 2012-11-29
Trends Cell Biol. 2012-11-2
J Cell Sci. 2012-7-13
Nature. 2012-2-19
Am J Physiol Heart Circ Physiol. 2012-1-6