MiR-551b-5p Contributes to Pathogenesis of Vein Graft Failure via Upregulating Early Growth Response-1 Expression

Abstract

Background:Vein graft failure (VGF) is a serious complication of coronary artery bypass graft, although the mechanism remains unclear. The study aimed to investigate the effects of microRNAs (miRNAs) on the endothelial dysfunction involved in VGF.Methods:Human umbilical vein endothelial cells (HUVECs) were subjected to mechanical stretch stimulation to induce endothelial dysfunction. Genome-wide transcriptome profiling was performed using the Human miRNA OneArray® V4 (PhalanxBio Inc., San Diego, USA). The miRNA-messenger RNA (mRNA) network was investigated using gene ontology and Kyoto Encyclopedia of Genes and Genomes. The miR-551b-5p mimic and inhibitor were applied to regulate miR-551b-5p expression in the HUVECs. The 5-ethynyl-2’-deoxyuridine assay, polymerase chain reaction (PCR), and Western blotting (WB) were used to assess HUVECs proliferation, mRNA expression, and protein expression, respectively. The vein graft model was established in early growth response (Egr)-1 knockout (KO) mice and wide-type (WT) C57BL/6J mice for pathological and immunohistochemical analysis. Endothelial cells isolated from the veins of WT and Egr-1 KO mice were subjected to mechanical stretch stimulation; PCR and WB were conducted to confirm the regulatory effect of Egr-1 on Intercellular adhesion molecule (Icam-1). One-way analysis of variance and independent t-test were performed for data analysis.Results:Thirty-eight miRNAs were differentially expressed in HUVECs after mechanical stretch stimulation. The bioinformatics analysis revealed that Egr-1 might be involved in VGF and was a potential target gene of miR-551b-5p. The mechanical stretch stimulation increased miR-551b-5p expression by 2.93 ± 0.08 fold (t = 3.07, P < 0.05), compared with the normal HUVECs. Transfection with the miR-551b-5p mimic or inhibitor increased expression of miR-551b-5p by 793.1 ± 171.6 fold (t = 13.84, P < 0.001) or decreased by 26.3% ± 2.4% (t = 26.39, P < 0.05) in the HUVECs, respectively. HUVECs proliferation and EGR-1 mRNA expression were significantly suppressed by inhibiting miR-551b-5p expression (P < 0.05). The lumens of the vein grafts in the Egr-1 KO mice were wider than that in the WT mice. Icam-1 expression was suppressed significantly in the Egr-1 KO vein grafts (P < 0.05).Conclusions:Increased miR-551b-5p expression leads to endothelial dysfunction by upregulating Egr-1 expression. EGR-1 KO can improve the function of a grafted vein through suppressing Icam-1.

Whole-Transcriptome Sequencing: A Powerful Tool for Vascular Tissue Engineering and Endothelial Mechanobiology

“…These miRNAs were involved in numerous signaling pathways, including those regulating apoptosis, cell cycle control, differentiation, and inflammation [ 129 ]. Similar results were obtained in the genome-wide analysis of miRNAs in HUVECs exposed to the cyclic strain for three hours (60 cycles/minute) [ 130 ].…”

Elevated Level of miR‐551b‐5p is Associated With Inflammation and Disease Progression in Patients With Severe Acute Pancreatitis

“…These findings have established a fundamental purpose for following functional studies. Increased miR‐551b‐5p expression was shown to lead to endothelial dysfunction by upregulating Egr‐1 expression . The diagnostic and prognostic value of miR‐551b‐5p has been studied in acute pancreatic patients .…”

The Role of Immunomodulation in Vein Graft Remodeling and Failure

“…MicroRNAs (miRNAs) target a multitude of genes including those that regulate gene expression in EC and VSMCs involving cell growth, differentiation, and metabolism. ECs that were mechanically stretched displayed an increase in miR-551b-5p expression [ 44 ]. The inhibition of miRNA-551b-5p reduced proliferation via inhibiting early growth response-1 (EGR-1) mRNA [ 45 ].…”