Department of Urology, Xiangya Hospital, Central South University, Changsha, China.
Department of Urology, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China.
Sci Rep. 2022 Aug 30;12(1):14746. doi: 10.1038/s41598-022-19141-4.
Urethral stricture is related to scar tissue fibrosis, but its pathogenesis is still unclear. This study aims to explore the regulatory mechanism of circular RNA (circRNA) in the occurrence and development of urethral stricture. CircRNA microarray was employed to analyze circRNA expression profiles between human urethral scar tissue and normal urethral tissue. The results of circRNA microarray showed that there were 296 differentially expressed genes between urethral scar tissue and normal urethral tissue. The enrichment analysis of 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. Urethral scar fibroblasts were isolated from human urethral scar tissue and cultured in vitro. After silencing circ_0047339, the proliferation of urethral scar cells decreased significantly, and the expressions of Collagen I (COL-1) and α-smooth muscle actin (α-SMA) also reduced. As a competing endogenous RNA, circ_0047339 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. Our results showed that circ_0047339 might promote the growth and fibrosis of urethral scar fibroblasts through miR-4691-5p/TSP-1 axis, thus promoting the development of urethral stricture.
尿道狭窄与瘢痕组织纤维化有关，但发病机制尚不清楚。本研究旨在探讨环状 RNA（circRNA）在尿道狭窄发生发展中的调控机制。采用环状 RNA 微阵列分析人尿道瘢痕组织与正常尿道组织中环状 RNA 表达谱。环状 RNA 微阵列的结果显示，尿道瘢痕组织与正常尿道组织之间有 296 个差异表达的基因。京都基因与基因组百科全书的富集分析表明，这些 circRNAs 与细胞外基质-受体相互作用显著相关。选择前 9 个差异表达的 circRNA 来预测 circRNA-miRNA 网络。实时定量 PCR 结果显示，circ_0047339 在尿道瘢痕组织中明显上调。从人尿道瘢痕组织中分离并体外培养尿道瘢痕成纤维细胞。沉默 circ_0047339 后，尿道瘢痕细胞的增殖明显减少，Collagen I（COL-1）和α-Smooth Muscle Actin（α-SMA）的表达也降低。作为竞争性内源性 RNA，circ_0047339 通过竞争性结合 miR-4691-5p 增加 TSP-1 的表达。此外，miR-4691-5p 模拟物转染可抑制尿道瘢痕成纤维细胞的增殖和血小板反应蛋白 1（TSP-1）、α-SMA 和 COL-1 的表达，而过表达 circ_0047339 则消除了这种抑制作用。我们的研究结果表明，circ_0047339 可能通过 miR-4691-5p/TSP-1 轴促进尿道瘢痕成纤维细胞的生长和纤维化，从而促进尿道狭窄的发展。
