Hsa_circ_0031608: A Potential Modulator of VSMC Phenotype in the Rupture of Intracranial Aneurysms.

Chuanchuan Wang,Yin Luo,Xiaozan Chang,Qinghai Huang,Pengfei Yang,Yazhou Yan,Jianmin Liu,Haishuang Tang,Rui Zhao,Qiang Li,Yi Xu,Bo Hong

doi:10.3389/fnmol.2022.842865

Abstract

Background and PurposePhenotypic modulation of vascular smooth muscle cells (VSMCs) plays an important role in the development of intracranial aneurysms (IAs). Growing evidence has demonstrated that circular RNAs (circRNAs) may serve as a potential modulator of VSMC phenotype in various vascular diseases. This study aimed to assess the potential function of circRNAs in the rupture of IAs and VSMC phenotypic modulation.MethodsUsing surgically dissected human ruptured (n = 8) and unruptured (n = 8) IA lesions, differentially expressed circRNAs were screened by transcriptomic sequencing and verified using qRT-PCR. Based on the screened circRNA, we predicted and screened the combined miRNA and downstream mRNAs to construct circRNA-miRNA-mRNA networks. Further in vitro experiments were performed to investigate the relationship between the validated circRNA and the phenotypic switching of VSMCs.ResultsWe found 1,373 differentially expressed genes in ruptured versus unruptured aneurysms. The top five dysregulated circRNAs were selected for qRT-PCR validation. We found hsa_circ_0031608 was both highly expressed in ruptured IAs and pro-inflammatory transformation of VSMCs. Then, a regulatory circRNA-miRNA-mRNA with one circRNA node, six miRNA nodes, and 84 mRNA nodes was constructed. GO analysis and KEGG pathway enrichment analysis were performed on mRNAs in the network. Then, a PPI network was built based on these mRNAs and five hub genes were identified (FOXO3, DICER1, CCND2, IGF1R, and TNRC6B) by the cytoHubba plugin in Cytoscape software. In vitro, overexpression of hsa_circ_0031608 influenced the expression of VSMC phenotypic markers validated by qPCR and Western blotting. Furthermore, hsa_circ_0031608 promoted the migration and proliferation capacity of VSMCs.Conclusionhsa_circ_0031608 regulated the phenotypic modulation of VSMCs and played an important role in the rupture of IAs. The specific mechanism should be further studied and confirmed.

Highlights

Intracranial aneurysm (IA) is a common cerebrovascular disease with a prevalence of 3.2% (Vlak et al, 2011)
We found hsa_circ_0031608 was both highly expressed in ruptured IAs and proinflammatory transformation of vascular smooth muscle cells (VSMCs)
16,836 circRNAs (79.21%) consisted of protein-coding exons from 6,772 host genes (Figure 1B and Supplementary Table 4), whereas smaller fractions aligned with circRNAs derived from intron lariats, intergenic circRNAs that consist of unannotated regions of the genome, antisense circRNAs transcribed from antisense regions, and sense overlapping circRNAs that originated from both exon and other sequences

Summary

Introduction

Intracranial aneurysm (IA) is a common cerebrovascular disease with a prevalence of 3.2% (Vlak et al, 2011). The preventive treatment of unruptured aneurysms with invasive procedures carries potential risks of serious complications. Owing to such a challenging clinical dilemma, identifying appropriate non-invasive treatment strategies for IAs is of paramount importance. Previous studies have revealed that phenotypic modulation of vascular smooth muscle cells (VSMCs) induced by abnormal hemodynamics and vascular inflammation may be associated with the development of IA (Kilic et al, 2005; Penn et al, 2014). Phenotypic modulation of vascular smooth muscle cells (VSMCs) plays an important role in the development of intracranial aneurysms (IAs). This study aimed to assess the potential function of circRNAs in the rupture of IAs and VSMC phenotypic modulation

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