Identification of differentially expressed miRNAs associated with thermal injury in epidermal stem cells based on RNA-sequencing

Abstract

Current research indicates that epidermal stem cells (EpSCs) play an important role in promoting wound healing, but the mechanism of action of these cells during wound repair following thermal damage remains unclear. In the present study, the trypsin digestion method was used to isolate human EpSCs and the cells were incubated in a 51.5°C water tank for 35 sec to construct a thermal injury model. The differentially expressed miRNAs were identified using high-throughput sequencing technology, and bioinformatic methods were used to predict their target genes and signaling pathways that may be involved in wound repair. A total of 33 miRNAs including, hsa-miR-1973, hsa-miR-4485-3p, hsa-miR-548-5p, hsa-miR-212-3p and hsa-miR-4461 were upregulated, whereas 21 miRNAs including, hsa-miR-4520-5p, hsa-miR-4661-5p, hsa-miR-191-3p, hsa-miR-129-5p, hsa-miR-147b and hsa-miR-6868-3p were downregulated following thermal injury of the human EpSCs. The bioinformatic analysis indicated that the differentially expressed miRNAs are involved in biological processes such as cell proliferation and differentiation, cell growth apoptosis, cell adhesion and migration. The results showed that there is a differential expression pattern of miRNAs after thermal injury of human EpSCs and these differences are involved in the regulation of the wound healing process. These findings provide new clues for further study of the wound healing mechanism and targeted therapy.

Keywords: epidermal stem cells; high-throughput sequencing; microRNA profiling; thermal damage.

Figure 1.

Morphological observation and identification of EpSCs (magnification, ×100). EpSCs at (A) initial inoculation, (B) after culturing for 2 days, (C) after a 37°C water bath (control group) and (D) after a 51.5°C water bath (experimental group). EpSCs showing (E) positive expression of integrin β1 and (F) positive expression of CK19. EpSCs, epidermal stem cells.

Figure 2.

miRNA cluster plots for the experimental and control groups. 1 represents the control group and 2 represents the experimental group. Red represents the miRNAs that are highly expressed in the sample and blue represents the miRNAs that have low expression in the sample. miRNA, microRNA.

Figure 3.

miRNAs with differential expression in the experimental and control samples. 1 represents the control group and 2 represents the experimental group. Red circles represent miRNAs with upregulated expression, gray circles indicate miRNAs with no significant difference and green circles represent miRNAs with downregulated expression in the two groups. miRNA, microRNA.

Figure 4.

(A) Kyoto Encyclopedia of Genes and Genomes pathway classification of the differentially expressed miRNA target genes in the experimental and control groups. (B) Gene Ontology enrichment map of the differentially expressed miRNA target genes. miRNA, microRNA.

Figure 4.

(A) Kyoto Encyclopedia of Genes and Genomes pathway classification of the differentially expressed miRNA target genes in the experimental and control groups. (B) Gene Ontology enrichment map of the differentially expressed miRNA target genes. miRNA, microRNA.