P2Y2 and Gq/G11 control blood pressure by mediating endothelial mechanotransduction
ShengPeng Wang, … , Nina Wettschureck, Stefan Offermanns
ShengPeng Wang, … , Nina Wettschureck, Stefan Offermanns
Published July 13, 2015
Citation Information: J Clin Invest. 2015;125(8):3077-3086. https://doi.org/10.1172/JCI81067.
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Research Article Vascular biology Article has an altmetric score of 64

P2Y2 and Gq/G11 control blood pressure by mediating endothelial mechanotransduction

Abstract

Elevated blood pressure is a key risk factor for developing cardiovascular diseases. Blood pressure is largely determined by vasodilatory mediators, such as nitric oxide (NO), that are released from the endothelium in response to fluid shear stress exerted by the flowing blood. Previous work has identified several mechanotransduction signaling processes that are involved in fluid shear stress–induced endothelial effects, but how fluid shear stress initiates the response is poorly understood. Here, we evaluated human and bovine endothelial cells and found that the purinergic receptor P2Y2 and the G proteins Gq/G11 mediate fluid shear stress–induced endothelial responses, including [Ca2+]i transients, activation of the endothelial NO synthase (eNOS), phosphorylation of PECAM-1 and VEGFR-2, as well as activation of SRC and AKT. In response to fluid shear stress, endothelial cells released ATP, which activates the purinergic P2Y2 receptor. Mice with induced endothelium-specific P2Y2 or Gq/G11 deficiency lacked flow-induced vasodilation and developed hypertension that was accompanied by reduced eNOS activation. Together, our data identify P2Y2 and Gq/G11 as a critical endothelial mechanosignaling pathway that is upstream of previously described mechanotransduction processes and demonstrate that P2Y2 and Gq/G11 are required for basal endothelial NO formation, vascular tone, and blood pressure.

Authors

ShengPeng Wang, András Iring, Boris Strilic, Julián Albarrán Juárez, Harmandeep Kaur, Kerstin Troidl, Sarah Tonack, Joachim C. Burbiel, Christa E. Müller, Ingrid Fleming, Jon O. Lundberg, Nina Wettschureck, Stefan Offermanns

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Figure 4

P2Y2 mediates endothelial fluid shear stress response in vitro.

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P2Y2 mediates endothelial fluid shear stress response in vitro. (A–D) BA...
(A–D) BAECs were transfected with scrambled siRNA (control) or siRNA directed against P2Y2 (A, B, and D) or were preincubated without or with 30 μM of the P2Y2 antagonist AR-C118925 (C). In the Fluo-4–loaded cells (A; n = 28 [control], n = 18 [P2Y2]; 3 independent experiments), the effect of the indicated shear forces on [Ca2+]i was determined as AUC and RFU fluorescence intensity. In B and C, cells were exposed to fluid shear (20 dynes/cm2) for the indicated durations, and AKT, eNOS, SRC, PECAM-1, and VEGFR-2 activation was determined as described. Graphs show the densitometric evaluation (n = 3). (D) Nitrate concentration in the cell medium (n = 3). (E) Amount of ATP in the supernatant of BAECs kept under static conditions or under flow (20 dynes/m2) for the indicated durations (n = 4). (F–H) BAECs (n = 4) were exposed to fluid shear (F and H; 20 dynes/cm2) or to 1 μM insulin for 10 minutes (G) in the absence or presence of 10 U/ml apyrase. AKT and eNOS activation was determined by Western blotting for phosphorylated and total AKT and eNOS (F and G). Bar diagrams show the densitometric evaluation. (H) Nitrate concentration in the cell medium. Data represent the mean ± SEM; *P ≤ 0.05, **P ≤ 0.01, and ***P ≤ 0.001, by 2-tailed Student’s t test (A) and 2-way ANOVA, with Bonferroni’s post-hoc test (B–H).