Abstract: BACKGROUND: Multiple studies have confirmed that mitogen-activated protein kinase (MAPK) signaling pathway is involved in cell proliferation, and microRNA (miR) is involved in the occurrence and development of hypertrophic scars. Therefore, the role of miR-27a-3p and MAPK signaling pathways in pathological scar formation has been further explored.
OBJECTIVE: To explore the effect of miR-27a-3p on the proliferation of human hypertrophic scar fibroblasts through the MAPK signaling pathway.
METHODS: The primary fibroblasts were isolated and collected from the skin samples. The primary fibroblasts were observed by inverted microscope and verified by immunofluorescence. The relative expression level of miR-27a-3p in tissues was detected by qRT-PCR. The target genes of hsa-miR-27a-3p were predicted using the database, and then the predicted target genes were enriched by gene ontology function analysis and biological pathway enrichment analysis of the Kyoto Encyclopedia of Genes and Genomes. There were seven groups: blank control, negative control, miR-27a-3p mimic, miR-27a-3p inhibitor, miR-27a-3p mimic+p38 MAPK inhibitor, miR-27a-3p mimic+extracellular regulated protein kinase inhibitor, miR-27a-3p mimic+c-Jun N-terminal kinase inhibitor. Western blot was used to detect the levels of extracellular regulated protein kinase, c-Jun N-terminal kinase inhibitor. and p38 kinase and their phosphorylation levels. Cell counting kit-8 and EdU were used to detect cell proliferation.
RESULTS AND CONCLUSION: Compared with normal skin fibroblasts, hypertrophic scar fibroblasts had stronger proliferative activity (P < 0.05) and faster proliferation level (P < 0.001). Compared with normal skin, miR-27a-3p was highly expressed in hypertrophic scars (P < 0.001). Compared with the negative control group, overexpression of miR-27a-3p could promote cell proliferation activity (P < 0.001) and proliferation levels (P < 0.001). Compared with the negative control group, knockdown of miR-27a-3p could inhibit the proliferation activity (P < 0.05) and proliferation levels (P < 0.001). Compared with the negative control group, overexpression of miR-27a-3p promoted the phosphorylated levels of extracellular regulated protein kinase, c-Jun N-terminal kinase, and p38 mitogen-activated protein kinase (P < 0.05). Compared with the negative control group, knockdown of miR-27a-3p inhibited the phosphorylated levels of extracellular regulated protein kinase, c-Jun N-terminal kinase, and p38 MAPK (P < 0.05). Compared with the miR-27a-3p mimic group, specific inhibitors of extracellular regulated protein kinase, c-Jun N-terminal kinase, and p38 MAPK reversed the effects of miR-27a-3p on the proliferative activity (P < 0.01) and proliferation level (P < 0.001) of fibroblasts. To conclude, these results suggest that miR-27a-3p promotes the proliferation of human hypertrophic scar fibroblasts by activating the MAPK signaling pathway.

中国组织工程研究杂志出版内容重点：组织构建；骨细胞；软骨细胞；细胞培养；成纤维细胞；血管内皮细胞；骨质疏松；组织工程

Key words: miR-27a-3p, mitogen-activated protein kinase, hypertrophic scar, fibroblast, proliferation