Objective To investigate the effects of down-regulating of Rfng gene ( 1, 3-Nacetylglucosaminyltransferases) in lung CD4 + T cells of asthmatic rat model by small interfering RNA ( siRNA) and explore the role of Rfng in pathogenesis of asthma. Methods An asthmatic rat model was established by OVA sensitization and challenge. Total T cells were isolated from lung tissue of asthmatic rats, and CD4 + T lymphocytes were purified using magnetic beads. CD4 + T lymphocytes were transfected by siRNA targeting Rfng gene. The mRNA and protein expressions of Rfng were detected by quantitative PCR and Western blot. Quantitative PCR was performed to determine the mRNA levels of Th1 /Th2 cytokines and related genes including IL-12, IFN-γ, IL-4, IL-5, T-bet, and GATA3. ELISA was performed to determine the concentrations of IL-12, IFN-γ, IL-4, and IL-5 in supernatant. Results The mRNA and protein expression of Rfng in RNAi group decreased significantly. IL-12, IFN-γ, T-bet increased and while IL-4, IL-5, and GATA3 decreased significantly. The concentrations of IL-12 and IFN-γ in the supernatant increased significantly, while IL-4 and IL-5 decreased significantly. Conclusions Down regulation of Rfng affects T cell differentiation. It is presumed that Fringe contribute to the pathogenesis of asthma.
Objective To construct the mouse NF-κB P65 subunit expression plasmid, and identify its biological activity. Methods NF-κB P65 siRNA retrovirus expression vectors were reconstructed by molecular clone technology. Recombinant vectors were transfected into 293E package cells and virus suspension was collected. RT-PCR was used to detect the expression level of NF-κB P65 mRNA and TNF-α mRNA at different time-point of LPS stimulation. Western blot was performed to analyze the protein level of NF-κB P65. ELISA was applied to detect the expression level of TNF-α released by LPS-stimulated J774A.1. Results NF-κB P65 siRNA retrovirus expression vectors of mouse were successfully constructed. From2 hours after the stimulation of LPS, the expression level of NF-κB P65 mRNA of the siRNA group was obviously lower than the scramble control group ( 0.91 ±0.03 vs. 1.02 ±0.02, Plt;0.01) . At24,36, 48 and 72 hours after the LPS stimulation, the expression level of NF-κB P65 protein of the siRNA group was significantly decreased compared with the scramble control group ( 0.97 ±0.02 vs. 1.01 ±0.01, 0.94 ± 0.01 vs. 1.02 ±0. 01,0.94 ±0.02 vs. 1.02 ±0.01, 0.93 ±0.01 vs. 1.00 ±0.02, Plt;0. 05) . At 2, 6, 12, 24 hours after the LPS stimulation, both the expression level of TNF-α mRNA and the content of TNF-α in the culture medium supernatant of the siRNA group were lower than the scramble control group ( Plt;0. 01) . Conclusions The construction of NF-κB P65 siRNA retrovirus expression vectors is feasible. Inflammation factors in mouse monocyte-macrophages are significantly inhibited after NF-κB expression is depressed by RNA interference technology, which may be applied to prevent and treat excessive inflammatory reaction in acute lung injury.