MiR-106a-5p modulates apoptosis and metabonomics changes by TGF-β/Smad signaling pathway in cleft palate.

Background: The molecular mechanisms of abnormal palatogenesis were investigated in this study. A key regulator, miR-106a-5p, and its target pathway were analyzed.

Objectives: This research is trying to clarify the underlying mechanism of the modulation of miRNA transcription during the formation of cleft palate by 7T and 9.4T NMR metabolomic platforms.

Method: Differentially expressed miRNAs and mRNAs were analyzed by microarray analysis and verified by qRT-PCR. The protein expression in TGFβ signaling pathways were analyzed by Western Blotting. The relationship between miR-106a-5p and TGFβ were analyzed by luciferase reporter assay. Cell apoptosis were analyzed by flow cytometer. And finally, the metabonomics were analyzed by NMR and multivariate data analysis models (MVDA).

Results: The expression of miR-106a-5p increased in cleft palatal tissue and negatively correlated with the protein level of Tgfbr2. The luciferase assay further proved that the tgfbr2 was a direct target of miR-106a-5p. In another aspect, miR-106a-5p increased apoptosis level in palatal mesenchymal cells, possibly because its inhibition of TGFβ signaling pathway. Moreover, low cholesterol and choline levels with high citric acid and lipid levels were observed by 7T and 9.4T NMR metabonomic analysis, which inferred the disorder of cell membrane synthesis in cleft palate formation. Furthermore, transformation from choline to phosphatidylcholine regulated by miR-106a-5p was also disrupted, resulting in phosphatidic choline synthesis disorder and reduced cell membrane synthesis.

Conclusions: The regulatory mechanism of cleft palate was studied at transcriptional and metabolomics levels, which may provide important information in understanding the primary cause of this abnormality.