Purinergic activation of Ca2+-permeable TRPV4 channels is essential for mechano-sensitivity in the aldosterone-sensitive distal nephron.
Purinergic activation of Ca2+-permeable TRPV4 channels is essential for mechano-sensitivity in the aldosterone-sensitive distal nephron.
复制标题
DOI：
10.1371/journal.pone.0022824
复制
发表时间：
2011
期刊：
影响因子：
3.7
通讯作者：
Pochynyuk O
中科院分区：
文献类型：
--
作者：
Mamenko M;Zaika O;Jin M;O'Neil RG;Pochynyuk O
已知机械力会诱导醛固酮敏感远端肾单位 (ASDN) 细胞中 [Ca2+]i 的增加，从而调节上皮转运。同时，机械应力刺激 ASDN 细胞释放 ATP。在这项研究中，我们将新鲜分离的裂开 ASDN 中基于比例 Fura-2 的 [Ca2+]i 监测与小鼠 P2Y2 和 TRPV4 的靶向删除相结合，以探讨嘌呤能信号在介导 ASDN 细胞机械敏感反应中的作用。 ATP 的应用导致可重复的瞬时 Ca2+ 峰值，然后是持续的平台期。皮质集合管 (CCD) 和连接小管 (CNT) 的各个细胞对嘌呤能刺激做出反应，[Ca2+]i 相对升高。此外，ATP 诱导的 Ca2+ 反应在主细胞（AQP2 阳性）和嵌入细胞（AQP2 阴性）中几乎相同，正如在分裂开放的 ASDN 中使用免疫组织化学所证实的那样。 UTP 应用产生的 [Ca2+]i 升高与使用 ATP 观察到的相似，表明 P2Y2 样受体在 [Ca2+]i 反应的产生中起主导作用。事实上，P2Y2 受体的基因缺失使 ATP 诱导的和 UTP 诱导的 Ca2+ 反应的强度分别降低了 70% 和 90% 以上。细胞内和细胞外的 Ca2+ 来源似乎都有助于 ASDN 细胞中 ATP 诱导的 Ca2+ 反应的产生。重要的是，在 P2Y2 −/− 小鼠中，血流和低渗诱导的 Ca2+ 升高明显减弱。我们进一步证明，机械敏感性 TRPV4 通道的激活在嘌呤能刺激期间 [Ca2+]i 持续升高中发挥着重要作用。与此一致的是，TRV4−/− 小鼠中 ATP 诱导的 Ca2+ 平台显着减弱。用 10 µM BTP2 抑制 TRPC 通道也降低了 ATP 诱导的 Ca2+ 平台，但程度低于 TRPV4 抑制/基因删除观察到的水平。我们得出的结论是，机械刺激对嘌呤能信号的刺激会导致 TRPV4 的激活，并在较小程度上激活 TRPC 通道，这是 ASDN 机械敏感反应的重要组成部分。
Mechanical forces are known to induce increases of [Ca2+]i in the aldosterone-sensitive distal nephron (ASDN) cells to regulate epithelial transport. At the same time, mechanical stress stimulates ATP release from ASDN cells. In this study, we combined ratiometric Fura-2 based monitoring of [Ca2+]i in freshly isolated split-opened ASDN with targeted deletion of P2Y2 and TRPV4 in mice to probe a role for purinergic signaling in mediating mechano-sensitive responses in ASDN cells. ATP application causes a reproducible transient Ca2+ peak followed by a sustained plateau. Individual cells of the cortical collecting duct (CCD) and the connecting tubule (CNT) respond to purinergic stimulation with comparative elevations of [Ca2+]i. Furthermore, ATP-induced Ca2+-responses are nearly identical in both principal (AQP2-positive) and intercalated (AQP2-negative) cells as was confirmed using immunohistochemistry in split-opened ASDN. UTP application produces elevations of [Ca2+]i similar to that observed with ATP suggesting a dominant role of P2Y2-like receptors in generation of [Ca2+]i response. Indeed, genetic deletion of P2Y2 receptors decreases the magnitude of ATP-induced and UTP-induced Ca2+ responses by more than 70% and 90%, respectively. Both intracellular and extracellular sources of Ca2+ appeared to contribute to the generation of ATP-induced Ca2+ response in ASDN cells. Importantly, flow- and hypotonic-induced Ca2+ elevations are markedly blunted in P2Y2 −/− mice. We further demonstrated that activation of mechano-sensitive TRPV4 channel plays a major role in the sustained [Ca2+]i elevation during purinergic stimulation. Consistent with this, ATP-induced Ca2+ plateau are dramatically attenuated in TRV4 −/− mice. Inhibition of TRPC channels with 10 µM BTP2 also decreased ATP-induced Ca2+ plateau whilst to a lower degree than that observed with TRPV4 inhibition/genetic deletion. We conclude that stimulation of purinergic signaling by mechanical stimuli leads to activation of TRPV4 and, to a lesser extent, TRPCs channels, and this is an important component of mechano-sensitive response of the ASDN.
登录
查看更多内容
影响因子：
3.7
作者：
Jin M;Wu Z;Chen L;Jaimes J;Collins D;Walters ET;O'Neil RG
通讯作者：
O'Neil RG
DOI：
10.1073/pnas.1735416100
发表时间：
2003-11-11
影响因子：
11.1
作者：
Liedtke, W;Friedman, JM
通讯作者：
Friedman, JM
影响因子：
6.3
作者：
Praetorius, H. A.;Leipziger, J.
通讯作者：
Leipziger, J.
影响因子：
4.5
作者：
Geyti, C. S.;Odgaard, E.;Praetorius, H. A.
通讯作者：
Praetorius, H. A.
影响因子：
7.8
作者：
Koetttgen, Michael;Buchholz, Bjoern;Garcia-Gonzalez, Miguel A.;Kotsis, Fruzsina;Fu, Xiao;Doerken, Mara;Boehlke, Christopher;Steffl, Daniel;Tauber, Robert;Wegierski, Tomasz;Nitschke, Roland;Suzuki, Makoto;Kramer-Zucker, Albrecht;Germino, Gregory G.;Watnick, Terry;Prenen, Jean;Nilius, Bernd;Kuehn, E. Wolfgang;Walz, Gerd
通讯作者：
Walz, Gerd