期刊
FRONTIERS IN PHYSIOLOGY
卷 10, 期 -, 页码 -出版社
FRONTIERS MEDIA SA
DOI: 10.3389/fphys.2019.01471
关键词
transient receptor potential vanilloid 4; Na+; Ca2+ exchanger; IP3 receptor; airway smooth muscle; carbachol
类别
资金
- National Natural Science Foundation of China [8197102295, U1732157, 81570403, 81371284]
- Natural Science Foundation of Anhui province [1708085MH187, 1608085MH194]
- Natural Science Foundation of Anhui Province Department of Education [KJ2018A0974]
Intracellular Ca2+ is critical for regulating airway smooth muscle (ASM) tension. A rapid rise in the intracellular Ca2+ concentration ([Ca2+](i)) of ASM cells is crucial for modulating the intensity and length of the ASM contraction. Because this rapid increase in [Ca2+](i) largely depends on the balance between Ca2+ released from intracellular Ca2+ stores and extracellular Ca2+ entry, exploring the mechanisms mediating Ca2+ transport is critical for understanding ASM contractility and the pathogenesis of bronchial contraction disorders. Transient receptor potential vanilloid 4 (TRPV4) is a highly Ca2+-permeable non-selective cation channel that mediates Ca2+ influx to increase [Ca2+](i), which then directly or indirectly regulates the contraction and relaxation of ASM. The [Ca2+](i) returns to basal levels through several uptake and extrusion pumps, such as the sarco(endo)plasmic reticulum Ca2+ ATPase and inositol 1,4,5-trisphosphate receptors (IP(3)Rs), the plasmalemmal Ca2+ ATPase, and the plasma membrane Na+/Ca2+ exchanger (NCX). Thus, to further understand ASM tension regulation in normal and diseased tissue, the present study examined whether an interaction exists among TRPV4, IP(3)Rs, and NCX. The TRPV4-specific and potent agonist GSK1016790A increased [Ca2+](i) in mouse ASM cells, an effect that was completely blocked by the TRPV4-specific antagonist HC067047. However, GSK1016790A induced relaxation in mouse tracheal rings precontracted with carbachol in vitro. To determine the mechanism underlying this TRPV4-induced relaxation of ASM, we blocked specific downstream molecules. We found that the GSK1016790A-induced relaxation was abolished by the NCX inhibitors KB-R7943 and LiCl but not by specific inhibitors of the Ca2+-activated large-, intermediate-, or small-conductance K+ channels (BKCa, IK, and SK3, respectively). The results of co-immunoprecipitation (co-IP) assays showed an interaction of TRPV4 and IP3R1 with NCXs. Taken together, these findings support a physical and functional interaction of TRPV4 and IP3R1 with NCXs as a novel TRPV4-mediated Ca2+ signaling mechanism and suggest a potential target for regulation of ASM tension and treatment of respiratory diseases, especially tracheal spasm.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据