Liraglutide Increases VEGF Expression via CNPY2-PERK Pathway Induced by Hypoxia/Reoxygenation Injury

Abstract

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. 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 extent, the current study further explored 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 and the effect of Lir on HUVECs was first evaluated by the Cell Counting Kit-8. Endothelial tube formation was used to analyze the ability of Lir to induce angiogenesis. Subsequently, the effect of Lir on the concentrations of hypoxia-inducible factor 1α (HIF1α), vascular endothelial growth factor (VEGF), and CNPY2 was detected by enzyme-linked immunosorbent assay. To assess whether Lir regulates angiogenesis through the CNPY2-initiated UPR pathway, the expression of UPR-related pathway proteins (CNPY2, GRP78, PERK, and ATF4) and angiogenic proteins (HIF1α and VEGF) was detected by reverse transcription-polymerase chain reaction 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 the 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 suggested that the CNPY2-PERK pathway was involved in the mechanism of VEGF expression after H/R injury in HUVECs. Lir increased the expression of VEGF through the CNPY2-PERK pathway, which may promote endothelial cell angiogenesis and protect HUVEC from H/R damage.

Liraglutide, a TFEB‐Mediated Autophagy Agonist, Promotes the Viability of Random‐Pattern Skin Flaps

“…GLP-1 is an intestinal insulin-stimulating peptide that has several functions, such as lowering blood sugar and improving insulin resistance [ 35 ]. In recent years, liraglutide has received increasing attention for its angiogenic activity in addition to its traditional function of lowering blood glucose levels [ 36 – 38 ]. Liraglutide promotes angiogenesis to improve heart function [ 37 ], significantly increases hypoxia-inducible factor 1 α (HIF1 α ) and VEGF expression during human umbilical vein endothelial cell (HUVEC) stimulation, and promotes angiogenesis [ 38 ].…”

“…In recent years, liraglutide has received increasing attention for its angiogenic activity in addition to its traditional function of lowering blood glucose levels [ 36 – 38 ]. Liraglutide promotes angiogenesis to improve heart function [ 37 ], significantly increases hypoxia-inducible factor 1 α (HIF1 α ) and VEGF expression during human umbilical vein endothelial cell (HUVEC) stimulation, and promotes angiogenesis [ 38 ]. Previous studies have shown that promoting angiogenesis is essential for the survival of flaps [ 5 , 8 , 39 ].…”

Dapagliflozin Promotes Neovascularization by Improving Paracrine Function of Skeletal Muscle Cells in Diabetic Hindlimb Ischemia Mice Through PHD2/HIF-1α Axis

“…Furthermore, we found that dapagliflozin increases the expression levels of angiogenic factors in skeletal muscle cells, such as VEGF-A, HGF, FGF2, PDGF-BB, and ANG-1. VEGF-A is the primary angiogenesis inducer, which is required to initiate neovessel formation by promoting endothelial cells' proliferation and migration (Semenza, 2003;Liu et al, 2019), while HGF is a potent mitogen of endothelial cells which works synergistically with VEGF-A to promote endothelial cells' function (Gerritsen, 2005). Furthermore, while VEGF-A is crucial for tube-formation, blood vessels induced merely by VEGF-A are immature and leaky, as they are not covered by the smooth muscle cells (Jain, 2003).…”

Calreticulin expression in human cardiac myocytes induces ER stress‐associated apoptosis

“…An increase in PERK phosphorylation was observed. Although PERK is often associated with increased apoptosis and CHOP induction in heart cells (Prola et al, ; Sun et al, ; Wang, Jia, Zhang, & Wang, ), noncanonical signaling may result in the secondary upregulation of protective factors, such as VEGF (Liu et al, ) In addition, ATF6 induction was abrogated after thapsigargin treatment, suggesting that calreticulin plays a role in the stimulation of this pathway during ER stress. ATF6 activation has been reported to mediate ER stress‐induced injury in several models, indicating that this may be a likely candidate for linking calreticulin to apoptosis (Correll et al, ; Sun et al, ; Zhou et al, ).…”