Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
Cardiovascular and Metabolic Research Unit, Lakehead University, Thunder Bay, ON, Canada.
Biochem Biophys Res Commun. 2014 Mar 28;446(1):393-8. doi: 10.1016/j.bbrc.2014.02.129. Epub 2014 Mar 12.
Here we explored the impact of hydrogen sulfide (H2S) on biophysical properties of the primary human airway smooth muscle (ASM)-the end effector of acute airway narrowing in asthma. Using magnetic twisting cytometry (MTC), we measured dynamic changes in the stiffness of isolated ASM, at the single-cell level, in response to varying doses of GYY4137 (1-10mM). GYY4137 slowly released appreciable levels of H2S in the range of 10-275 μM, and H2S released was long lived. In isolated human ASM cells, GYY4137 acutely decreased stiffness (i.e. an indicator of the single-cell relaxation) in a dose-dependent fashion, and stiffness decreases were sustained in culture for 24h. Human ASM cells showed protein expressions of cystathionine-γ-lyase (CSE; a H2S synthesizing enzyme) and ATP-sensitive potassium (KATP) channels. The KATP channel opener pinacidil effectively relaxed isolated ASM cells. In addition, pinacidil-induced ASM relaxation was completely inhibited by the treatment of cells with the KATP channel blocker glibenclamide. Glibenclamide also markedly attenuated GYY4137-mediated relaxation of isolated human ASM cells. Taken together, our findings demonstrate that H2S causes the relaxation of human ASM and implicate as well the role for sarcolemmal KATP channels. Finally, given that ASM cells express intrinsic enzymatic machinery of generating H2S, we suggest thereby this class of gasotransmitter can be further exploited for potential therapy against obstructive lung disease.
在这里，我们探讨了硫化氢（H2S）对原代人呼吸道平滑肌（哮喘时急性气道狭窄的效应器）生物物理特性的影响。我们使用磁扭细胞术（MTC），在单细胞水平上测量了 GYY4137（1-10mM）不同剂量下分离的 ASM 的刚度的动态变化。GYY4137 缓慢释放出 10-275μM 范围内相当数量的 H2S，且 H2S 释放的半衰期较长。在分离的人 ASM 细胞中，GYY4137 以剂量依赖性方式急性降低刚度（即单细胞松弛的指标），并且刚度降低在培养 24 小时后持续存在。人 ASM 细胞显示胱硫醚-γ-裂解酶（CSE；一种 H2S 合成酶）和 ATP 敏感性钾（KATP）通道的蛋白表达。KATP 通道开放剂 pinacidil 有效地松弛了分离的 ASM 细胞。此外，用 KATP 通道阻滞剂格列本脲处理细胞可完全抑制 pinacidil 诱导的 ASM 松弛。格列本脲还显著减弱了 GYY4137 介导的分离人 ASM 细胞的松弛。总之，我们的研究结果表明 H2S 导致人 ASM 的松弛，并暗示了肌膜 KATP 通道的作用。最后，鉴于 ASM 细胞表达产生 H2S 的内在酶促机制，我们建议可以进一步利用这一类气体递质来治疗阻塞性肺疾病。
