Biology subjects

Leo, M. D.

Publications and source records attributed to Leo, M. D..

4 recordsLinked to original sources

bioRxiv2026

Wnts are endothelial cell-derived PKD1/PKD2-dependent autocrine/paracrine vasodilators

BackgroundWingless/Int-1 (Wnts) proteins are canonical Frizzled receptor ligands. Recent evidence indicates that some Wnts, including Wnt9b and Wnt5a, bind to polycystin 1 (PKD1), a transmembrane protein which can couple to polycystin 2 (PKD2) to form a non-selective cation channel. The functional significance of Wnts binding to PKD1 is unclear. Here, we tested the hypothesis that Wnts act through PKD1/PKD2 channels on endothelial cells (ECs) to regulate arterial contractility and blood pressure and investigated the cellular source and secretory regulation of vasoactive Wnt proteins. MethodsA wide variety of approaches, including inducible EC-specific PKD1 and PKD2 knockout mice, reverse-transcription polymerase chain reaction, Western blotting, immunofluorescence, pressurized artery myography, blood pressure measurements, patch-clamp electrophysiology, in vivo and in vitro Wnt and nitric oxide assays, and Wnt secretion assays. ResultsIntravascular Wnt9b or Wnt5a administration stimulates an EC PKD1/PKD2-dependent dilation in pressurized resistance-size arteries. Wnt9b and Wnt5a are present in serum and plasma and intravenous infusion rapidly stimulates a blood pressure reduction which requires EC PKD1. Wnts stimulate a PKD1-dependent non-selective cation current in ECs which through Ca2+ signaling activates endothelial nitric oxide synthase (eNOS) and small conductance Ca2+-activated K+ channels to induce vasodilation. Wnt9b acts solely via PKD1/PKD2 channels, whereas Wnt5a stimulates signaling through PKD1/PKD2, Frizzled-7 (Fzd-7), Dishevelled and c-Jun N-terminal kinase (JNK). Intravascular flow stimulates angiotensin II type 1 (AT1) receptors, which through Gq/11 and Porcupine activate Wnt9b and Wnt5a secretion in ECs. Wnts secreted in response to flow activate PKD1/PKD2 signaling in ECs and contribute to flow-mediated vasodilation. ConclusionsIntravascular flow activates AT1 receptors, which through Gq/11 and Porcupine stimulate Wnt9b and Wnt5a secretion in ECs. Wnt9b activates PKD1/PKD2 channels whereas Wnt5a stimulates both PKD1/PKD2 and Fzd-7 in ECs to induce vasodilation. Wnts contribute to flow-mediated autocrine/paracrine dilation and reduce blood pressure. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=92 SRC="FIGDIR/small/712518v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@1fa876aorg.highwire.dtl.DTLVardef@d05bd5org.highwire.dtl.DTLVardef@13d276corg.highwire.dtl.DTLVardef@1e75b7b_HPS_FORMAT_FIGEXP M_FIG C_FIG

physiology↗

bioRxiv2023

Vasodilators activate TMEM16A channels in endothelial cells to reduce blood pressure

Endothelial cells (ECs) regulate vascular contractility to control regional organ blood flow and systemic blood pressure. Several cation channels are expressed in ECs which regulate arterial contractility. In contrast, the molecular identity and physiological functions of anion channels in ECs is unclear. Here, we generated tamoxifen-inducible, EC-specific TMEM16A knockout (TMEM16A ecKO) mice to investigate the functional significance of this chloride (Cl-) channel in the resistance vasculature. Our data demonstrate that TMEM16A channels generate calcium-activated Cl- currents in ECs of control (TMEM16Afl/fl) mice that are absent in ECs of TMEM16A ecKO mice. Acetylcholine (ACh), a muscarinic receptor agonist, and GSK101, a TRPV4 agonist, activate TMEM16A currents in ECs. Single molecule localization microscopy data indicate that surface TMEM16A and TRPV4 clusters locate in very close nanoscale proximity, with [~]18% exhibiting overlap in ECs. ACh stimulates TMEM16A currents by activating Ca2+ influx through surface TRPV4 channels without altering the size or density of TMEM16A or TRPV4 surface clusters, their spatial proximity or colocalization. ACh-induced activation of TMEM16A channels in ECs produces hyperpolarization in pressurized arteries. ACh, GSK101 and intraluminal ATP, another vasodilator, all dilate pressurized arteries through TMEM16A channel activation in ECs. Furthermore, EC-specific knockout of TMEM16A channels elevates systemic blood pressure in conscious mice. In summary, these data indicate that vasodilators stimulate TRPV4 channels, leading to Ca2+-dependent activation of nearby TMEM16A channels in ECs to produce arterial hyperpolarization, vasodilation and a reduction in blood pressure. We identify TMEM16A as an anion channel present in ECs that regulates arterial contractility and blood pressure. One sentence summaryVasodilators stimulate TRPV4 channels, leading to calcium-dependent activation of nearby TMEM16A channels in ECs to produce arterial hyperpolarization, vasodilation and a reduction in blood pressure.

physiology↗

bioRxiv2021

A plasma membrane-localized polycystin-1/polycystin-2 complex in endothelial cells elicits vasodilation

Polycystin-1 (PC-1, PKD1), a receptor-like protein expressed by the Pkd1 gene, is present in a wide variety of cell types, but its cellular location, signaling mechanisms and physiological functions are poorly understood. Here, by studying tamoxifen-inducible, endothelial cell (EC)-specific Pkd1 knockout (Pkd1 ecKO) mice, we show that flow activates PC-1-mediated, Ca2+-dependent cation currents in ECs. EC-specific PC-1 knockout attenuates flow-mediated arterial hyperpolarization and vasodilation. PC-1-dependent vasodilation occurs over the entire functional shear stress range and primarily via the activation of nitric oxide synthase (NOS), with a smaller contribution from small-conductance Ca2+-activated K+ (SK) channels. EC-specific PC-1 knockout increases systemic blood pressure without altering kidney anatomy. PC-1 coimmunoprecipitates with polycystin-2 (PC-2, PKD2), a TRP polycystin channel, and clusters of both proteins locate in nanoscale proximity in the EC plasma membrane. Knockout of either PC-1 or PC-2 (Pkd2 ecKO mice) abolishes surface clusters of both PC-1 and PC-2 in ECs. Single knockout of PC-1 or PC-2 or double knockout of PC-1 and PC-2 (Pkd1/Pkd2 ecKO mice) similarly attenuates flow-mediated vasodilation. Flow stimulates non-selective cation currents in ECs that are similarly inhibited by either PC-1 or PC-2 knockout or by interference peptides corresponding to the C-terminus coiled-coil domains present in PC-1 or PC-2. In summary, we show that PC-1 regulates arterial contractility and demonstrate that this occurs through the formation of an interdependent signaling complex with PC-2 in endothelial cells. Flow stimulates PC-1/PC-2 clusters in the EC plasma membrane, leading to Ca2+ influx, NOS and SK channel activation, vasodilation and a reduction in blood pressure.

physiology↗

bioRxiv2018

Arterial smooth muscle cell PKD2 (TRPP1) channels control systemic blood pressure

Systemic blood pressure is determined, in part, by arterial smooth muscle cells (myocytes). Several Transient Receptor Potential (TRP) channels are proposed to be expressed in arterial myocytes, but it is unclear if these proteins control physiological blood pressure and contribute to hypertension in vivo. We generated the first inducible, smooth muscle-specific knockout for a TRP channel, namely for PKD2 (TRPP1), to investigate arterial myocyte and blood pressure regulation by this protein. Using this model, we show that intravascular pressure and 1-receptors activate PKD2 channels in arterial myocytes of different systemic organs. PKD2 channel activation in arterial myocytes leads to an inward Na+ current, membrane depolarization and vasoconstriction. Inducible, smooth muscle cell-specific PKD2 knockout lowers both physiological blood pressure and hypertension and prevents pathological arterial remodeling during hypertension. In summary, we show for the first time that arterial myocyte PKD2 channels control systemic blood pressure and targeting reduces high blood pressure.

neuroscience↗