Differential expression of microRNAs in serum of severe burn patients and analysis of the signaling pathway at early stage

Objective To explore differential expression of microRNAs in serum of patients with severe burn and analysis of the signaling pathway at early stage. Methods In this study, we included three healthy adult volunteers and three patients with severe burn, conforming to the inclusion criteria and hospitalized in Tongren Hospital of Wuhan University & Wuhan Third Hospital in July 2015. Venous whole blood of 6 mL of each burn patient and healthy volunteer was collected at 24 to 48 h post injury of burn patients. The whole blood was divided into burn group and healthy control group. Whole blood of 2 mL of each one was used to determine white blood cell count and neutrophile granulocyte content. Serum was separated from the other whole blood of 4 mL of each one. Half of serum was used to determine content of blood glucose, total protein, and albumin; another half of serum was used to extract total RNA with Trizol method. The differentially expressed microRNA, with differential expression ratio larger than or equal to 1.500 between 2 groups, were screened by microRNA chip technique. Then cluster analysis and functional enrichment analysis of Kyoto encyclopedia of genes and genomes (KEGG) signaling pathway were performed on the differentially expressed microRNAs. Data were processed with t test. Results (1) Content of white blood cell count, neutrophile granulocyte of whole blood, and blood glucose of serum of patients in burn group was obviously higher than that in healthy control group (with t values from 4.27 to 7.83, P<0.05 or P<0.01). Content of total protein and albumin of serum of patients in burn group was significantly lower than that in healthy control group (with t values respectively -12.80 and -12.36, P values below 0.01). (2)Compared with those in serum of healthy control group, differential expression ratios of 48 microRNAs in serum of burn group were larger than 1.500, with 22 up-regulated microRNAs and 26 down-regulated microRNAs. MicroRNA expression profile in serum of burn group was different from that of healthy control group. (3)Functional enrichment analysis of KEGG signaling pathway showed that compared with those in serum of healthy control group, microRNAs of differential expression in serum of burn group took part in tumor transcription misregulation signaling pathway, tumor proteoglycan signaling pathway, long-term potentiation signaling pathway, tumor associated microRNAs signaling pathway, citrate cycle signaling pathway, tumor necrosis factor signaling pathway, focal adhesion signaling pathway, endocytosis signaling pathway, insulin secretion signaling pathway, and estrogen signaling pathway. Conclusions MicroRNA expression profile in serum of patients with severe burn is different from that in serum of healthy adults. MicroRNAs of differential expression may take part in important pathophysiological process of energy metabolism, inflammatory response, and regulation of blood glucose at early stage of severe burn.