Purinergic activation of Ca 2+-permeable TRPV4 channels is essential for mechano-sensitivity in the aldosterone-sensitive distal nephron

38Citations
Citations of this article
35Readers
Mendeley users who have this article in their library.

Abstract

Mechanical forces are known to induce increases of [Ca 2+] 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 [Ca 2+] 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 Ca 2+ 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 [Ca 2+] i. Furthermore, ATP-induced Ca 2+-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 [Ca 2+] i similar to that observed with ATP suggesting a dominant role of P2Y2-like receptors in generation of [Ca 2+] i response. Indeed, genetic deletion of P2Y2 receptors decreases the magnitude of ATP-induced and UTP-induced Ca 2+ responses by more than 70% and 90%, respectively. Both intracellular and extracellular sources of Ca 2+ appeared to contribute to the generation of ATP-induced Ca 2+ response in ASDN cells. Importantly, flow- and hypotonic-induced Ca 2+ elevations are markedly blunted in P2Y2 -/- mice. We further demonstrated that activation of mechano-sensitive TRPV4 channel plays a major role in the sustained [Ca 2+] i elevation during purinergic stimulation. Consistent with this, ATP-induced Ca 2+ plateau are dramatically attenuated in TRV4 -/- mice. Inhibition of TRPC channels with 10 μM BTP2 also decreased ATP-induced Ca 2+ 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. © 2011 Mamenko et al.

Cite

CITATION STYLE

APA

Mamenko, M., Zaika, O., Jin, M., O’Neil, R. G., & Pochynyuk, O. (2011). Purinergic activation of Ca 2+-permeable TRPV4 channels is essential for mechano-sensitivity in the aldosterone-sensitive distal nephron. PLoS ONE, 6(8). https://doi.org/10.1371/journal.pone.0022824

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free