LncRNA-NONMMUT100923.1 as a ceRNA regulates mouse embryonic palatal shelf adhesion via medial epithelial cell desmosome junction during palatogenesis

Background: Long non-coding RNA (lncRNA) is involved in cleft palate (CP) formation, but its regulatory mechanism remains unknown. We explored the molecular mechanisms ofLncRNA-NONMMUT100923.1 as a competing endogenous RNA (ceRNA) during CP formation. Methods: RNA-sequencing was performed for lncRNA, microRNA (miRNA), and mRNA expression profiling of mouse embryonic palatal shelf (MEPS) tissue samples in the normal group vs. model group (all- trans- retinoic acid-induced group). Differentially expressed RNAs and potential ceRNAs were screened, and their functions were predicted through bioinformatics analysis. Reverse transcription-PCR was conducted to verify the expression levels of LncRNA-NONMMUT100923.1, Cdsn , and miR-200a-3p in both groups. Fluorescence in situ hybridization was used to determine the subcellular location of LncRNA-NONMMUT100923.1 and miR-200a-3p in MEPS epithelial cells. A luciferase reporter assay was performed to investigate the interaction relationships among miR-200a-3p, LncRNA-NONMMUT100923.1, and Cdsn in HEK293T cells. Gain-and loss-of-function experiments (cell transfection, western blotting, cell counting kit-8, cell colony formation, and EdU staining) were conducted to evaluate the biological effects of LncRNA-NONMMUT100923.1 on MEPS adhesion and MEPS epithelial cell desmosome junction. Results: ALncRNA-NONMMUT100923.1-miR-200a-3p-Cdsn ceRNA regulatory network was constructed through bioinformatics analysis based on RNA-sequencing results. The results of reverse transcription-PCR were consistent with those of RNA-sequencing. LncRNA-NONMMUT100923.1 and miR-200a-3p were localized mainly in the cytoplasm and LncRNA-NONMMUT100923.1 negatively regulated the expression of miR-200a-3p, followed by the regulation of its direct target, Cdsn . Gain- and loss-of-function experiments demonstrated that the overexpression of LncRNA-NONMMUT100923.1 inhibited medial edge epithelium (MEE) cell proliferation, migration, and epithelial-mesenchymal transition by preventing the disintegration of the desmosome junction in MEE cells in vitro . Conclusions: We revealed a potential ceRNA regulatory network in which LncRNA-NONMMUT100923.1 regulates Cdsn expression by competitively binding to endogenous miR-200a-3p during palatogenesis, which inhibits MEPS adhesion by preventing the disintegration of the desmosome junction in MEE cells.