Circ_CLASP2 Regulates High Glucose-Induced Dysfunction of Human Endothelial Cells Through Targeting miR-140-5p/FBXW7 Axis.

Qin Zhang,Lisheng Zheng,Xuelian Ma,Jing Long,Nannan Li

doi:10.3389/fphar.2021.594793

Abstract

Hyperglycemia exposure results in the dysfunction of endothelial cells (ECs) and the development of diabetic complications. Circular RNAs (circRNAs) have been demonstrated to play critical roles in EC dysfunction. The current study aimed to explore the role and mechanism of circRNA CLIP–associating protein 2 (circ_CLASP2, hsa_circ_0064772) on HG-induced dysfunction in human umbilical vein endothelial cells (HUVECs). Quantitative real-time polymerase chain reaction (qRT-PCR) was used to assess the levels of circ_CLASP2, miR-140-5p and F-box, and WD repeat domain-containing 7 (FBXW7). The stability of circ_CLASP2 was identified by the actinomycin D and ribonuclease (RNase) R assays. Cell colony formation, proliferation, and apoptosis were measured by a standard colony formation assay, colorimetric 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay, and flow cytometry, respectively. Western blot analysis was performed to determine the expression of related proteins. Targeted correlations among circ_CLASP2, miR-140-5p, and FBXW7 were confirmed by dual-luciferase reporter assay. High glucose (HG) exposure downregulated the expression of circ_CLASP2 in HUVECs. Circ_CLASP2 overexpression or miR-140-5p knockdown promoted proliferation and inhibited apoptosis of HUVECs under HG conditions. Circ_CLASP2 directly interacted with miR-140-5p via pairing to miR-140-5p. The regulation of circ_CLASP2 overexpression on HG-induced HUVEC dysfunction was mediated by miR-140-5p. Moreover, FBXW7 was a direct target of miR-140-5p, and miR-140-5p regulated HG-induced HUVEC dysfunction via FBXW7. Furthermore, circ_CLASP2 mediated FBXW7 expression through sponging miR-140-5p. Our current study suggested that the overexpression of circ_CLASP2 protected HUVEC from HG-induced dysfunction at least partly through the regulation of the miR-140-5p/FBXW7 axis, highlighting a novel therapeutic approach for the treatment of diabetic-associated vascular injury.

Highlights

Endothelial cells (ECs) are a type of simple squamous cells that form the inner lining of blood vessels, which control the infiltration of blood cells and proteins into the vessel wall (Dejana, 2004; dela Paz and D’Amore, 2009)
The management of diabetes has mainly focused on the control of hyperglycemia, which is a contributing factor for its macrovascular complications (Marcovecchio et al, 2011)
We focused on the function of circ_CLASP2 on HGinduced human umbilical vein endothelial cells (HUVECs) dysfunction

Summary

Introduction

Endothelial cells (ECs) are a type of simple squamous cells that form the inner lining of blood vessels, which control the infiltration of blood cells and proteins into the vessel wall (Dejana, 2004; dela Paz and D’Amore, 2009). One promising biomarker is based on circular RNAs (circRNAs) (Shang et al, 2018; Jin et al, 2019). The abnormal expression and role of circRNAs in ECs dysfunction induced by high glucose (HG) have been widely investigated (Liu et al, 2017; Pei et al, 2018; Shang et al, 2018; Jin et al, 2019; Zhang and Sui, 2020). Cheng et al highlighted that has_circ_0068087 was highly expressed in HGtriggered human umbilical vein endothelial cells (HUVECs) and regulated HG-induced cell dysfunction by acting as an miR-197 sponge (Cheng et al, 2019). The function and mechanism of circ-CLASP2 on HG-induced HUVEC dysfunction remain to be elucidated

Methods

Results

Conclusion