Identification of Pathways and Key Genes in Venous Remodeling After Arteriovenous Fistula by Bioinformatics Analysis

Kong Jie,Chen Liang,Lou Wensheng,Zhao Boxiang,He Xu,Lu Zhaoxuan,Chen Guoping,Zhou Yangyi,Wen Jianyan,Gong Maofeng,Gu Jianping,Su Haobo,Zhang Jianbin,Wang Feng

doi:10.3389/fphys.2020.565240

Kong Jie, Chen Liang + Show 12 more

Open Access

https://doi.org/10.3389/fphys.2020.565240

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Abstract

The arteriovenous fistula (AVF) is the first choice for vascular access for hemodialysis of renal failure patients. Venous remodeling after exposure to high fistula flow is important for AVF to mature but the mechanism underlying remodeling is still unknown. The objective of this study is to identify the molecular mechanisms that contribute to venous remodeling after AVF. To screen and identify the differentially expressed genes (DEGs) that may involve venous remodeling after AVF, we used bioinformatics to download the public microarray data (GSE39488) from the Gene Expression Omnibus (GEO) and screen for DEGs. We then performed gene ontology (GO) function analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and gene set enrichment analysis (GSEA) for the functional annotation of DEGs. The protein-protein interaction (PPI) network was constructed and the hub genes were carried out. Finally, we harvested 12 normal vein samples and 12 AVF vein samples which were used to confirm the expressions of the hub genes by immunohistochemistry. A total of 45 DEGs were detected, including 32 upregulated and 13 downregulated DEGs. The biological process (BP) of the GO analysis were enriched in the extrinsic apoptotic signaling pathway, cGMP-mediated pathway signaling, and molting cycle. The KEGG pathway analysis showed that the upregulated DEGs were enriched in glycosaminoglycan biosynthesis and purine metabolism, while the downregulated DEGs were mainly enriched in pathways of glycosaminoglycan biosynthesis, antifolate resistance, and ABC transporters. The GSEA analysis result showed that the top three involved pathways were oxidative phosphorylation, TNFA signaling via NF-K B, and the inflammatory response. The PPI was constructed and the hub genes found through the method of DMNC showed that INHBA and NR4A2 might play an important role in venous remodeling after AVF. The integrated optical density (DOI) examined by immunohistochemistry staining showed that the expression of both INHBA and NR4A2 increased in AVF compared to the control group. Our research contributes to the understanding of the molecular mechanism of venous remodeling after exposure to high fistula flow, which may be useful in treating AVF failure.

Highlights

Incidences of chronic kidney disease (CKD) and end-stage renal disease (ESRD) are rising due to the aging population and the increasing prevalence of diabetes (Vachharajani et al, 2014)
The Principal component analysis (PCA) of the GSE39488 showed that the intra-group data repeatability was acceptable
The gene set enrichment analysis (GSEA) analysis represented the top three pathways/gene sets in which the arteriovenous fistula (AVF) samples were significantly involved in oxidative phosphorylation, TNFA signaling via NF-κB, and the inflammatory response

Summary

Introduction

Incidences of chronic kidney disease (CKD) and end-stage renal disease (ESRD) are rising due to the aging population and the increasing prevalence of diabetes (Vachharajani et al, 2014). Hemodialysis (HD) is the treatment of choice for ESDR patients, and over 1.5 million people worldwide receive regular HD (Grassmann et al, 2005). Well-functioning vascular access is crucial for hemodialysis (HD) patients and the ideal permanent vascular access for HD is through the native arteriovenous fistula (AVF) (Roy-Chaudhury et al, 2001; Grassmann et al, 2005; Vascular Access Work Group, 2006; Sadaghianloo et al, 2015). The outflow vein is dilated and its wall is thickened due to increased blood flow after the construction of autogenous AV access (Dixon, 2006). The outflow vein commonly matures for HD 3 to 4 months after creation, almost 60% of AVFs fail to mature sufficiently. Our poor understanding of the molecular mechanism of venous remodeling after the construction of AVF limits our ability to predict or prevent the non-maturation of AVF (Dixon, 2006; Dember et al, 2014)

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