Integrative mRNA/miRNA expression analysis in healing human gingiva

Background: MicroRNAs (miRNAs) are implicated in the epigenetic regulation of complex biological processes. Their possible role in human oral wound healing, a process that differs from cutaneous wound healing by being faster and typically scar-free, has been unexplored. This report presents the miRNA expression profile of experimental human oral wounds and an integrative analysis of mRNA/miRNA expression. Methods: Nine healthy volunteers provided standardized normal and 5-day healing palatal biopsies, used for next generation miRNA and mRNA sequencing analysis, correlation and network analysis, real-time PCR (qPCR) and immunohistochemistry. Results: On average, 169 significantly regulated precursor miRNAs were detected, including 21 novel miRNAs, selectively confirmed by PCR. Hsa-miR-223-3p and hsa-miR-124-3p were, respectively, the most up- and downregulated miRNAs in healing gingiva. Hsa-miR-124-3p had the most predicted mRNA target interactions, with angiogenesis-related genes the most enriched. Correlation analysis showed the highest correlation between hsa-miR-181a-3p and SERPINB1; hsa-miR-223-5p and SLC2A3; hsa-miR-1301 and MS4A7. In addition, SERPINB1 mRNA had the most associations with differentially regulated miRNAs. IL33 was the only cytokine significantly correlated with miRNAs (ρ > 0.95). qPCR and immunohistochemistry verified the significant upregulation of SERPINB1 and IL33 in healing gingiva. Conclusions: This study is the first to report on the miRNome of healing human gingiva and to provide an integrative analysis of miRNA/mRNA expression during human oral wound healing; the results offer novel insights into the participating molecular mechanisms and raise the possibility of SERPINB1 and IL-33 as potential wound healing therapeutic targets.