RESUMEN
Objective To analyze the differential expression of microRNA-146a (miR-146a) in monocyte-macrophage cell line (THP-1 cells) after induction by Cryptococcus neoformans (C.neoformans,reference strain WM148) or Cryptococcus gattii (C.gattii,reference strain R265),and investigate the mechanism of miR-146a in regulating the inflammatory response of cryptococcal meningitis.Methods The cultured THP-1 cells were divided into two groups to be induced by C.neoformans or C.gattii,respectively.THP-1 cells were induced with inactivated WN148 (or R265) strains at multiplicity of infection (MOI) of 5 in all experiments.The supematant and the cell pellet were collected separately after incubation.The expression of miR-146a was measured by real-time quantitative PCR (qRT-PCR) technique.The levels of TNF-u and IL-6 release were assayed by ELISA.Results The expression of miR-146a increased significantly in the C.neoformans induction group compared to 0 h.It reached peak at 3 h (P＜0.01),and then declined gradually.The level of TNF-α increased in supematant and reached peak at 12 h.The expression of IL-6 did not change significantly at each time point.The expression of miR-146a and TNF-α increased gradually and reached peak at 12 h in the C.gattii induction group (P ＜0.01),but the change did not reach statistical significance at 3 h,6 h time points.The expression of IL-6 gradually increased,and reached peak at 12 h time point.Conclusions Following stimulation with C.neoformans or C.gattii,the expression ofmiR-146a in THP-1 cells showed different patterns over time.The expression levels of TNF-α and IL-6 showed different patterns.These findings suggest that there may be different regulatory mechanisms in the THP-1 cells-associated inflammatory response after stimulation by inactivated C.neoformans and C.gattii strains.