Identification and Functional Analysis of Serum Specific MiRNAs in Patients with Recurrent Aphthous Somatitis of Excess-heat or Yin-deficiency Syndrome

Background: MiRNAs has become an important regulator in many processes. The purpose of our study is to screen the key serum miRNAs of different syndrome of recurrent aphthous stomatitis (RAS), to find new biomarkers for the diagnosis of RAS and to further explore their role in the pathogenesis of RAS.Method. Serum samples were collected from patients meeting the RAS diagnostic criteria of excess-heat or yin-deficiency syndrome and healthy individuals. Core miRNAs were then identified under miRNA microarray analyses. Target prediction and bioinformatic analyses were carried out and gene-pathway-networks were visualized to better understand the relationship between different genes and pathways.Result. (1) 90 individuals meeting the inclusion criteria were collected in this study, of which 30 were normal control, 30 were patients of excess-heat syndrome and the rest were patients of yin-deficiency syndrome. Among them, 9 miRNAs were screened out in excess-heat syndrome group, with 1 upregulated and 8 downregulated. And four random miRNAs (hsa-miR-20b-5p, hsa-miR-122-5p, hsa-miR-483-5p and hsa-miR-3197) were validated by real-time PCR method. 14 miRNAs were screened out in yin-deficiency syndrome group (7 upregulated and 7 downregulated). And hsa-miR-17-5p, hsa-miR-106-5p and hsa-miR-20b-5p were validated. (2) A total of 4776 target genes were identified for the validated 9 miRNAs in excess-heat syndrome group. These targets were enriched in GO categories including nervous system development, homophilic cell adhesion via plasma membrane adhesion molecules, and calcium ion binding and KEGG pathway such as proteoglycans in cancer, P13K-AKT signaling pathway and Calcium signaling pathway. 10172 target genes were identified for the validated 14 miRNAs in yin-deficiency syndrome group. The enriched GO categories included protein binding, positive regulation of transcription from RNA polymerase II promoter and membrane and enriched KEGG pathway included pathways in cancer, MAPK signaling pathway and Ras signaling pathway .Conclusion. Hsa-miR-20b-5p in patients with RAS could act as the novel biomarker for clinical diagnosis of the disease. It is upregulated in RAS patients of excess-heat syndrome while downregulated in patients of yin-deficiency syndrome. The PI3K-Akt signaling pathway and MAPK signaling pathway and related target genes may provide new insights into the molecular mechanisms of excess-heat syndrome and yin-deficiency syndrome RAS, respectively.