Upregulation of miR-92a-2-5p potentially contribute to anorectal malformations by inhibiting proliferation and enhancing apoptosis via PRKCA/β-catenin

Abstract

Anorectal malformations (ARMs) is one of the most common gastrointestinal anomalies. Previous research revealed that miR-92a-2-5p was upregulated in ARMs. However, the underlying roles remains unknown. The current study was to further investigate the spatiotemporal expression patterns of miR-92a-2-5p and its target gene protein kinase C alpha (PRKCA) predicted by bioinformatic method, and to explore their potential functions in anorectal malformations (ARMs). Rat models with ethylenethiourea-induced ARMs were made for subsequent experiments. Direct target relationship between miR-92a-2-5p and PRKCA was validated using a luciferase reporter assay. The spatiotemporal expression pattern of miR-92a-2-5p was evaluated using fluorescence in situ hybridization (FISH), while the expression of PRKCA was revealed by immunohistochemical staining and western blotting. IEC-6 cells were transfected with mimics/mimics NC (Negative control)/inhibitor/inhibitor NC of miR-92a-2-5p or si-PRKCA/si-PRKCA NC, respectively. Then the downstream molecules of miR-92a-2-5p, PRKCA and β-catenin, were subsequently detected. Meanwhile, apoptosis and viability assays were measured. Dual luciferase assay confirmed the direct regulatory relationship between miR-92a-2-5p and PRKCA. FISH revealed that miR-92a-2-5p was expressed with a higher level in ARMs fetuses. Further analyses of PRKCA showed lower protein expression level in ARMs group, which was opposite to miR-92a-2-5p. In vitro experiments revealed that overexpression of miR-92a-2-5p or knockdown of PRKCA can down-regulate PRKCA, up-regulate and facilitate nuclear localization of β-catenin, increase apoptosis and decrease proliferation of IEC-6. Taken together, these findings suggest that aberrantly high expression of miR-92a-2-5p potentially contribute to ARMs by inhibiting proliferation and enhancing apoptosis of intestinal cells via negatively regulating PRKCA/β-catenin.

Keywords

• Anorectal malformation
• Spatiotemporal expression
• Proliferation
• Apoptosis
• Development