Circ_0047339 promotes the activation of fibroblasts and affects the development of urethral stricture by targeting the miR-4691-5p/TSP-1 axis
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ABSTRACT: Background: Urethral stricture is related to scar tissue fibrosis, but its pathogenesis is still unclear. This study aims to explore the mechanism of circular RNA (circRNA) in the occurrence and development of urethral stricture. Methods: CircRNA microarray was employed to analyze circRNA expression profiles between human urethral scar tissue and normal urethral tissue. The first nine circRNA differentially expressed were selected for RT-qPCR detection. Urethral scar fibroblasts were isolated from human urethral scar tissue and cultured in vitro. The cells were transfected with si-circ_0047339, LV-circ_0047339, and miR-4691-5p mimic and their corresponding negative controls. Related gene and protein expression was measured by RT-qPCR, Western Blot and immunofluorescence staining, and the cell function was detected by CCK-8 and EDU assay. The targeting relationship between miR-4691-5p and circ_0047339 or TSP-1 was analyzed by dual-luciferase reporter assay. Results: The results of circRNA microarray showed that there were 268 differential genes between urethral scar tissue and normal urethral tissue (circRNA expression difference multiple ≥2 and p value≤0.05). The enrichment analysis of KEGG (Kyoto encyclopedia of genes and genomes) showed that these circRNAs were significantly correlated with ECM-receptor interaction. The first nine differentially expressed circRNA were selected to predict the circRNA-miRNA network. RT-qPCR results showed that circ_0047339 was upregulated considerably in urethral scar tissue. After silencing circ_0047339, the proliferation of urethral scar cells decreased significantly, and the expression of collagen 1 (COL-1) and α-smooth muscle actin (α-SMA) also reduced. Circ_0047339 as a competing endogenous RNA (ceRNA) could increase the expression of TSP-1 by competitively binding miR-4691-5p. In addition, miR-4691-5p mimic transfection could inhibit the proliferation of urethral scar fibroblasts and the presentation of thrombospondin-1 (TSP-1), α-SMA and COL-1, while circ_0047339 overexpression eliminated this inhibition. Conclusion: Our results showed that the dysfunctional circ_0047339 might promote the growth and fibrosis of urethral scar fibroblasts through the ceRNA mechanism, thus promoting the development of urethral stricture via miR-4691-5p/TSP-1 axis.
ORGANISM(S): Homo sapiens
PROVIDER: GSE209937 | GEO | 2022/07/30
REPOSITORIES: GEO
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