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PI3K-C2β limits mTORC1 signaling and angiogenic growth

Item Type:Article
Title:PI3K-C2β limits mTORC1 signaling and angiogenic growth
Creators Name:Kobialka, P. and Llena, J. and Deleyto-Seldas, N. and Munar-Gelabert, M. and Dengra, J.A. and Villacampa, P. and Albinyà-Pedrós, A. and Muixi, L. and Andrade, J. and van Splunder, H. and Angulo-Urarte, A. and Potente, M. and Grego-Bessa, J. and Castillo, S.D. and Vanhaesebroeck, B. and Efeyan, A. and Graupera, M.
Abstract:Phosphoinositide 3-kinases (PI3Ks) phosphorylate intracellular inositol lipids to regulate signaling and intracellular vesicular trafficking. Mammals have eight PI3K isoforms, of which class I PI3Kα and class II PI3K-C2α are essential for vascular development. The class II PI3K-C2β is also abundant in endothelial cells. Using in vivo and in vitro approaches, we found that PI3K-C2β was a critical regulator of blood vessel growth by restricting endothelial mTORC1 signaling. Mice expressing a kinase-inactive form of PI3K-C2β displayed enlarged blood vessels without corresponding changes in endothelial cell proliferation or migration. Instead, inactivation of PI3K-C2β resulted in an increase in the size of endothelial cells, particularly in the sprouting zone of angiogenesis. Mechanistically, we showed that the aberrantly large size of PI3K-C2β mutant endothelial cells was caused by mTORC1 activation, which sustained growth in these cells. Consistently, pharmacological inhibition of mTORC1 with rapamycin normalized vascular morphogenesis in PI3K-C2β mutant mice. Together, these results identify PI3K-C2β as a crucial determinant of endothelial signaling and illustrate the importance of mTORC1 regulation during angiogenic growth.
Keywords:Cell Proliferation, Endothelial Cells, Phosphatidylinositol 3-Kinases, Phosphatidylinositol 3-Kinases, Protein Isoforms, Signal Transduction, Animals, Mice, Mammals
Source:Science Signaling
Publisher:American Association for the Advancement of Science
Page Range:eadg1913
Date:November 2023
Official Publication:https://doi.org/10.1126/scisignal.adg1913
PubMed:View item in PubMed

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