Aim
To investigate the expression of microRNA155 (miRNA155) in trinitrobenzene sulphonic acid (TNBS)-induced colitis and the relationship between miRNA155 and tumor necrosis factor (TNF) expressions.
Conclusion
miRNA155 is induced in colons and activated CD4(+) T cells in TNBS colitis, and the levels of miRNA155 and TNF expressions have a significant positive correlation.
Methods
In TNBS colitis mice, miRNA155 and TNF mRNA expressions were measured in colons and CD4(+) T cells of draining lymph nodes (LNs). CD4(+) T cells were cultured in vitro with or without anti-CD3/CD28 antibody, and the expressions of miRNA155 and TNF mRNA in cells and TNF concentration in culture media were examined.
Results
miRNA155 and TNF mRNA expressions in colons and in cells of LNs were significantly increased in TNBS colitis compared with controls. In TNBS colitis, miRNA155 and TNF mRNA expressions in CD4(+) T cells of LNs and TNF concentration in CD4(+) T cells culture media increased compared with controls. When cultured with anti-CD3/CD28 antibody, miRNA155 and TNF mRNA expressions in CD4(+) T cells and TNF concentration in the CD4(+) T cells culture media were significantly higher than those cultured without anti-CD3/CD28 antibody. Following analysis using the Pearson's correlation coefficient, miRNA155 expression had a significant positive correlation with either TNF mRNA expression in CD4(+) T cells (r = 0.860, P < 0.05) or TNF concentration in CD4(+) T cells culture media (r = 0.892, P < 0.05).