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Original Research ARTICLE Provisionally accepted The full-text will be published soon. Notify me

Front. Pharmacol. | doi: 10.3389/fphar.2019.00789

Liraglutide increases VEGF expression via CNPY2-PERK pathway induced by hypoxia/reoxygenation injury

 Chong Liu1, Yong Liu1, Rong Mu1, Yanbo Di1, Na Shen1, Xuan Liu1, Xiao Gao1, Jinhui Wang1, Tie Chen1, Tao Fang1, Huanming Li1* and  Fengshi Tian1*
  • 1Tianjin Fourth Central Hospital, China

Liraglutide (Lir) is a glucagon-like peptide-1 receptor agonist that lowers blood sugar and reduces myocardial infarct size by improving endothelial cell function. However, its mechanism has not yet been clarified. Unfolded protein response (UPR) plays an important role in the pathogenesis of myocardial ischemia-reperfusion injury (MIRI). It determines the survival of cells. Endoplasmic reticulum position protein homologue 2 (CNPY2) is a novel initiator of UPR that also participates in angiogenesis. To this extend, the current study further explores whether Lir regulates angiogenesis through CNPY2. In our article, a hypoxia/reoxygenation (H/R) injury model of human umbilical vein endothelial cells (HUVECs) was established, Lir effect on HUVECs was first evaluated by CCK-8. Endothelial tube formation was used to analyze the ability of Lir to induce angiogenesis. Subsequently, the effect of Lir on the concentrations of HIF1α, VEGF and CNPY2 were detected by ELISA. To assess whether Lir regulates angiogenesis through the CNPY2-initiated UPR pathway, expression of UPR-related pathway proteins (CNPY2, GRP78, PERK, ATF4) and angiogenic proteins (HIF1α, VEGF) were detected by RT-PCR and Western blot. The results confirmed that Lir significantly increased the expression of HIF1α and VEGF, as well as the expression of CNPY2-PERK pathway proteins in HUVECs after H/R injury. To further validate the experimental results, we introduced the PERK inhibitor, GSK2606414. GSK2606414 was able to significantly decrease both mRNA and protein expression of ATF4, HIF1α and VEGF in vascular endothelial cells after H/R injury. The effect of Lir was also inhibited using GSK2606414. Therefore, our study suggests that CNPY2-PERK pathway is involved in the mechanism of VEGF expression after H/R injury in HUVECs. Lir increases the expression of VEGF through the CNPY2-PERK pathway, which may promote endothelial cell angiogenesis and protect HUVEC from H/R damage.

Keywords: liraglutide, Angiogenesis, CNPY2, Unfolded Protein Response, Hypoxia/reoxygenation

Received: 18 Feb 2019; Accepted: 18 Jun 2019.

Edited by:

Bimal Malhotra, Pfizer (United States), United States

Reviewed by:

Marc Iglarz, Idorsia Pharmaceuticals Ltd, Switzerland
Juan Badimon, Icahn School of Medicine at Mount Sinai, United States  

Copyright: © 2019 Liu, Liu, Mu, Di, Shen, Liu, Gao, Wang, Chen, Fang, Li and Tian. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence:
Prof. Huanming Li, Tianjin Fourth Central Hospital, Tianjin, Hebei, China,
Prof. Fengshi Tian, Tianjin Fourth Central Hospital, Tianjin, Hebei, China,