Sodium-calcium exchange in intracellular calcium handling of human airway smooth muscle.
Sodium-calcium exchange in intracellular calcium handling of human airway smooth muscle.
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DOI：
10.1371/journal.pone.0023662
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发表时间：
2011
期刊：
影响因子：
3.7
通讯作者：
Prakash YS
中科院分区：
文献类型：
--
作者：
Sathish V;Delmotte PF;Thompson MA;Pabelick CM;Sieck GC;Prakash YS
肿瘤坏死因子α或白介素13等细胞因子引起的炎症后气道收缩功能的增强涉及到气道平滑肌细胞内钙离子水平的升高。在ASM中，质膜Ca~(2+)通量是[Ca~(2+)]_i调节的重要组成部分。越来越多的证据表明，质膜Na~+/Ca~(2+)双向交换器(NCX)参与ASM[Ca~(2+)]_i的调节。在本研究中，我们检测了正常条件下和暴露于肿瘤坏死因子α或IL-13后，Ncx在人ASM细胞中的表达和功能。Western印迹分析显示NCX1亚型显著表达，两种细胞因子均可增加NCX1的水平，而核因子NF-κB或丝裂原活化蛋白激酶的抑制剂可减弱这种作用。细胞因子介导的NCX1的增加包括转录增强，随后是蛋白质合成。即使在细胞因子刺激的ASM中也未检测到NCX2和NCX3。在Fura-2负载的人ASM细胞中，通过改变细胞外Na+和Ca~(2+)水平，NCX介导的内向和外向钙交换(以[Ca~(2+)]i的变化率来衡量)被激发。用Na+荧光指示剂SBFI测定[Na+]i，验证了NCX的贡献。在NCX抑制剂KBR7943的存在下，NCX介导的内向交换被证实是阻止[Ca~(2+)]i升高或[Na+]i下降的。内向交换型NCX受肿瘤坏死因子α和IL-13的促进作用大于向外交换型NCX。NCX siRNA显著钝化了向外交换和向内交换模式。最后，抑制Ncx的表达或功能可钝化组胺刺激后的[Ca~(2+)]i峰值和[Ca~(2+)]i的下降速率。这些数据表明，NCX介导的钙离子流在人ASM中正常存在(可能有助于快速的钙离子流)，并有助于增强气道炎症中的[钙]i调节。
Enhanced airway contractility following inflammation by cytokines such as tumor necrosis factor alpha (TNFα) or interleukin-13 (IL-13) involves increased intracellular Ca2+ ([Ca2+]i) levels in airway smooth muscle (ASM). In ASM, plasma membrane Ca2+ fluxes form a key component of [Ca2+]i regulation. There is now growing evidence that the bidirectional plasma membrane Na+/Ca2+ exchanger (NCX) contributes to ASM [Ca2+]i regulation. In the present study, we examined NCX expression and function in human ASM cells under normal conditions, and following exposure to TNFα or IL-13. Western blot analysis showed significant expression of the NCX1 isoform, with increased NCX1 levels by both cytokines, effects blunted by inhibitors of nuclear factor NF-κB or mitogen-activated protein kinase. Cytokine-mediated increase in NCX1 involved enhanced transcription followed by protein synthesis. NCX2 and NCX3 remained undetectable even in cytokine-stimulated ASM. In fura-2 loaded human ASM cells, NCX-mediated inward Ca2+ exchange as well as outward exchange (measured as rates of change in [Ca2+]i) was elicited by altering extracellular Na+ and Ca2+ levels. Contribution of NCX was verified by measuring [Na+]i using the fluorescent Na+ indicator SBFI. NCX-mediated inward exchange was verified by demonstrating prevention of rising [Ca2+]i or falling [Na+]i in the presence of the NCX inhibitor KBR7943. Inward exchange-mode NCX was increased by both TNFα and IL-13 to a greater extent than outward exchange. NCX siRNA transfection substantially blunted outward exchange and inward exchange modes. Finally, inhibition of NCX expression or function blunted peak [Ca2+]i and rate of fall of [Ca2+]i following histamine stimulation. These data suggest that NCX-mediated Ca2+ fluxes normally exist in human ASM (potentially contributing to rapid Ca2+ fluxes), and contribute to enhanced [Ca2+]i regulation in airway inflammation.
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DOI：
10.1152/ajplung.00188.2005
发表时间：
2006-02-01
影响因子：
4.9
作者：
Ay, B;Iyanoye, A;Pabelick, CM
通讯作者：
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DOI：
10.1152/ajplung.1997.273.2.l322
发表时间：
1997-08-01
影响因子：
4.9
作者：
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DOI：
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发表时间：
2009-08-01
影响因子：
5.3
作者：
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影响因子：
3.3
作者：
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DOI：
10.1152/ajplung.1997.272.4.l659
发表时间：
1997-04-01
影响因子：
4.9
作者：
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