Shivam , Chandel and Mahesh, Chandran and Abdul, Jaleel (2021) The protein tyrosine phosphatase PTP-PEST mediates hypoxia-induced endothelial autophagy and angiogenesis via AMPK activation. Journal of cell science, 134 (1). ISSN 1477-9137

Text Protein tyrosine phosphatase-P.pdf Restricted to Registered users only Download (3001Kb)

Abstract

Global and endothelial loss of PTP-PEST (also known as PTPN12) is associated with impaired cardiovascular development and embryonic lethality. Although hypoxia is implicated in vascular remodelling and angiogenesis, its effect on PTP-PEST remains unexplored. Here we report that hypoxia (1% oxygen) increases protein levels and catalytic activity of PTP-PEST in primary endothelial cells. Immunoprecipitation followed by mass spectrometry revealed that α subunits of AMPK (α1 and α2, encoded by PRKAA1 and PRKAA2, respectively) interact with PTP-PEST under normoxia but not in hypoxia. Co-immunoprecipitation experiments confirmed this observation and determined that AMPK α subunits interact with the catalytic domain of PTP-PEST. Knockdown of PTP-PEST abrogated hypoxia-mediated tyrosine dephosphorylation and activation of AMPK (Thr172 phosphorylation). Absence of PTP-PEST also blocked hypoxia-induced autophagy (LC3 degradation and puncta formation), which was rescued by the AMPK activator metformin (500 µM). Because endothelial autophagy is a prerequisite for angiogenesis, knockdown of PTP-PEST also attenuated endothelial cell migration and capillary tube formation, with autophagy inducer rapamycin (200 nM) rescuing angiogenesis. In conclusion, this work identifies for the first time that PTP-PEST is a regulator of hypoxia-induced AMPK activation and endothelial autophagy to promote angiogenesis.

Item Type:	Article
Uncontrolled Keywords:	AMPK; Angiogenesis; Autophagy; Hypoxia; PTP-PEST.
Subjects:	Cardiovascular Diseases And Diabetes Biology
Depositing User:	Central Library RGCB
Date Deposited:	06 Jan 2022 06:22
Last Modified:	06 Jan 2022 06:23
URI:	http://rgcb.sciencecentral.in/id/eprint/1069

Actions (login required)

View Item