Lysophosphatidic acid–induced YAP/TAZ activation promotes developmental angiogenesis by repressing Notch ligand Dll4
Daisuke Yasuda, … , Satoru Takahashi, Satoshi Ishii
Daisuke Yasuda, … , Satoru Takahashi, Satoshi Ishii
Published July 23, 2019
Citation Information: J Clin Invest. 2019;129(10):4332-4349. https://doi.org/10.1172/JCI121955.
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Research Article Angiogenesis

Lysophosphatidic acid–induced YAP/TAZ activation promotes developmental angiogenesis by repressing Notch ligand Dll4

Abstract

Lysophosphatidic acid (LPA) is a potent lipid mediator with various biological functions mediated through six G protein–coupled receptors (GPCRs), LPA1–LPA6. Previous studies have demonstrated that LPA–Gα12/Gα13 signaling plays an important role in embryonic vascular development. However, the responsible LPA receptors and underlying mechanisms are poorly understood. Here, we show a critical role of LPA4 and LPA6 in developmental angiogenesis. In mice, Lpa4;Lpa6 double-knockout (DKO) embryos were lethal due to global vascular deficiencies, and endothelial cell–specific (EC-specific) Lpa4;Lpa6-DKO retinas had impaired sprouting angiogenesis. Mechanistically, LPA activated the transcriptional regulators YAP and TAZ through LPA4/LPA6–mediated Gα12/Gα13–Rho–ROCK signaling in ECs. YAP/TAZ knockdown increased endothelial expression of the Notch ligand delta-like ligand 4 (DLL4) that was mediated by β-catenin and Notch intracellular domain (NICD). Fibrin gel sprouting assay revealed that LPA4/LPA6, Gα12/Gα13, or YAP/TAZ knockdown consistently blocked EC sprouting, which was rescued by a Notch inhibitor. Notably, the inhibition of Notch signaling also ameliorated impaired retinal angiogenesis in EC-specific Lpa4;Lpa6-DKO mice. Overall, these results suggest that the Gα12/Gα13–coupled receptors LPA4 and LPA6 synergistically regulate endothelial Dll4 expression through YAP/TAZ activation. This could in part account for the mechanism of YAP/TAZ–mediated developmental angiogenesis. Our findings provide insight into the biology of GPCR-activated YAP/TAZ.

Authors

Daisuke Yasuda, Daiki Kobayashi, Noriyuki Akahoshi, Takayo Ohto-Nakanishi, Kazuaki Yoshioka, Yoh Takuwa, Seiya Mizuno, Satoru Takahashi, Satoshi Ishii

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Figure 8

Impairment of EC sprouting by LPA4/LPA6–Gα12/Gα13–YAP/TAZ signaling blockade is ameliorated by a Notch inhibitor.

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Impairment of EC sprouting by LPA4/LPA6–Gα12/Gα13–YAP/TAZ signaling bloc...
(A–C) LPA4/LPA6, Gα12/Gα13, or YAP/TAZ siRNAs consistently suppressed the length and number of sprouts from the HUVEC-coated beads. DAPT (1 μM) significantly ameliorated the sprouting defects. Representative fluorescence images of sprouting are shown in A. Scale bars: 100 μm. Quantitative analyses of total length (B) and number (C) of sprouts were performed. Data are mean ± SEM (n = 10 beads). (D–F) Y27632 (10 μM) suppressed the length and number of sprouts from the HUVEC-coated beads. DAPT (1 μM) significantly ameliorated the sprouting defects. Representative fluorescence images of sprouting are shown in D. Scale bars: 100 μm. Quantitative analyses of length (E) and number (F) of sprouts were performed. Data are mean ± SEM (n = 10 beads). (G–I) LPA4/LPA6 deficiency or Y27632 (10 μM) treatment suppressed the length and number of sprouts from mouse lung EC-coated beads. DAPT (10 μM) significantly ameliorated the sprouting defects. Representative fluorescence images of sprouting are shown in G. Scale bars: 100 μm. Quantitative analyses of total length (H) and number (I) of sprouts were performed. Data are mean ± SEM (n = 8–11 beads). ECs are stained green with calcein. *P < 0.05, **P < 0.01, ***P < 0.001, 1-way ANOVA followed by Tukey’s multiple-comparisons test.