Hsa_circRNA_102610 upregulation in Crohn's disease promotes transforming growth factor-β1-induced epithelial-mesenchymal transition via sponging of hsa-miR-130a-3p.

Background The incidence of inflammatory bowel disease, a chronic intestinal inflammatory disorder that includes Crohn's disease (CD) and ulcerative colitis, is rising. Circular RNAs are considered valuable diagnostic biomarkers for CD. Current evidence supports the views that epithelial-mesenchymal transition (EMT) plays an important role in CD pathogenesis, and that hsa-miR-130a-3p can inhibit transforming growth factor-β1 (TGF-β1)-induced EMT. Our previous study revealed that hsa_circRNA_102610 was upregulated in CD patients. Moreover, we predicted an interaction between hsa_circRNA_102610 and hsa-miR-130a-3p. Thus, we hypothesized that hsa_circRNA_102610 may play roles in the proliferation and EMT of intestinal epithelial cells by sponging hsa-miR-130a-3p to participate in the pathogenesis of CD. Aim To explore the mechanism of hsa_circRNA_102610 in the pathogenesis of CD. Methods The relative expression levels of hsa_circRNA_102610 and hsa-miR-130a-3p in patients were detected by quantitative reverse transcription-polymerase chain reaction. The proliferation of human intestinal epithelial cells (HIECs) and normal-derived colon mucosa cell line 460 (NCM460) cells was detected by cell counting kit-8, 5-ethynyl-2'-deoxyuridine staining and cell cycle assays following overexpression or downregulation of hsa_circRNA_102610. Cell proliferation assays were performed as described above in a rescue experiment with hsa-miR-130a-3p mimics. The interaction of hsa_circRNA_102610 and hsa-miR-130a-3p was verified by fluorescence in situ hybridization and dual luciferase reporter assays. The relative expression levels of CyclinD1, mothers against decapentaplegic homolog 4 (SMAD4), E-cadherin, N-cadherin and Vimentin were detected by western blotting following hsa_circRNA_102610 overexpression, TGF-β1-induced EMT or hsa-miR-130a-3p mimic transfection (in rescue experiments). Results Upregulation of hsa_circRNA_102610 was determined to be positively correlated with elevated fecal calprotectin levels in CD (r = 0.359, P = 0.007) by Pearson correlation analysis. Hsa_circRNA_102610 promoted the proliferation of HIECs and NCM460 cells, while hsa-miR-130a-3p reversed the cell proliferation-promoting effects of hsa_circRNA_102610. Fluorescence in situ hybridization and dual luciferase reporter assays showed that hsa_circRNA_102610 directly bound hsa-miR-130a-3p in NCM460 and 293T cells. An inverse correlation between downregulation of hsa-miR-130a-3p and upregulation of hsa_circRNA_102610 in CD patients was observed (r = -0.290, P = 0.024) by Pearson correlation analysis. Moreover, overexpression of hsa_circRNA_102610 promoted SMAD4 and CyclinD1 protein expression validated by western-blotting. Furthermore, over-expression of hsa_circRNA_102610 promoted TGF-β1 induced EMT in HIECs and NCM460 cells via targeting of hsa-miR-130a-3p, with increased expression of Vimentin and N-cadherin and decreased expression of E-cadherin. Conclusion Hsa_circRNA_102610 upregulation in CD patients could promote the proliferation and EMT of intestinal epithelial cells via sponging of hsa-miR-130a-3p.