[Analysis of microRNA expression profile in serum of patients with electrical burn or thermal burn]

Objective: To explore the differential expression of microRNAs in the serum among patients with electrical burn or thermal burn and healthy persons and to explore the significance. Methods: In this study we included three patients with electrical burn and three patients with thermal burn, conforming to the inclusion criteria and hospitalized in our burn ward from June to August 2015, and three healthy adult volunteers. Their serum samples were separated from whole blood and divided into electrical burn group, thermal burn group, and normal control group. Total RNA was extracted from their serum samples using Trizol method. The differentially expressed microRNAs (with differential ratio larger than or equal to 2.000, less than or equal to 0.500) among the three groups were screened by microRNA chip technique. Then cluster and Venn diagram analysis of the differentially expressed microRNAs were performed. Enrichment analysis of Kyoto encyclopedia of genes and genomes (KEGG) signaling pathway was performed on the distinctly changed microRNAs (with differential ratio larger than or equal to 5.000, less than or equal to 0.500). Results: There were 220 differentially expressed microRNAs among serum of the three groups. MicroRNA expression profiles in serum of electrical burn and thermal burn groups were different from that in serum of normal control group. Compared with those in serum of normal control group, the expressions of 59 microRNAs changed more than 2.000 times in serum of electrical burn group, with 50 up-regulated microRNAs and 9 down-regulated microRNAs; the expressions of 40 microRNAs changed more than 2.000 times in serum of thermal burn group, with 21 up-regulated microRNAs and 19 down-regulated microRNAs. Compared with those in serum of thermal burn group, the expressions of 167 microRNAs changed more than 2.000 times in serum of electrical burn group. There were 17 exclusively expressed microRNAs in serum of thermal burn group and 26 exclusively expressed microRNAs in serum of electrical burn group, compared with those in serum of normal control group. Enrichment analysis of KEGG signaling pathway showed that compared with those in serum of normal control group, microRNAs which changed distinctly in serum of electrical burn group took part in the insulin secretion signaling pathway, arrhythmogenic right ventricular cardiomyopathy signaling pathway, hypertrophic cardiomyopathy signaling pathway, glutamatergic synapse signaling pathway, calcium signaling pathway, cyclic adenosine monophosphate signaling pathway, glycerophospholipid metabolism, pyrimidine metabolism, serotonergic synapse signaling pathway, etc, while microRNAs which changed distinctly in serum of thermal burn group took part in the tumor transcription misregulation signaling pathway, proteoglycans in tumor signaling pathway, microRNAs in tumor signaling pathway, long-term potentiation signaling pathway, citrate cycle signaling pathway, tumor necrosis factor signaling pathway, focal adhesion signaling pathway, endocytosis signaling pathway, insulin secretion signaling pathway, p53 signaling pathway, and estrogen signaling pathway, etc. Conclusions: MicroRNA expression profiles in serum of electrical and thermal burn are different from that in serum of healthy adult. The signaling pathways enriched with target genes which are regulated by the differentially expressed microRNAs are related to the pathological changes and clinical manifestations after electrical or thermal burn.