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 andSERPINB1; hsa-miR-223-5p andSLC2A3; hsa-miR-1301 andMS4A7. In addition,SERPINB1mRNA had the most associations with differentially regulated miRNAs.IL33was the only cytokine significantly correlated with miRNAs (rho > 0.95). qPCR and immunohistochemistry verified the significant upregulation ofSERPINB1andIL33in 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.