ObjectiveTo investigate whether the miR-33s negatively regulates LPS-induced production of inflammatory cytokines by targeting p38 MAPK. MethodsHuman monocytes THP-1 cells were cultured in vitro and transfected with miR-33s mimic (25 nmol/L) or miR-33s inhibitor (25 nmol/L)by TransIT-X2? Dynamic Delivery System for 24 h. Then the transfected THP-1 cells were stimulated by LPS of 10.0 ng/mL for 24 h. The expression of miR-33s and p38 MAPK protein were measured by semi-quantitative RT-PCR. The concentrations of TNF-α,IL-6 and IL-1β in the cultured supernatant were assessed by ELISA. ResultsThe transfection of miR-33s mimic significantly increased the release of TNF-α,IL-6 and IL-1β(P<0.05). The expression of p38 MAPK protein was also significantly reduced(P<0.05). However,the pre-treatment of miR-33s inhibitor reversed the LPS-induced release of TNF-α,IL-6,and IL-1β,and the expression of p38 MAPK protein of THP-1 cells. ConclusionmiR-33s may play an important role in the regulation in inflammatory factors released from THP-1 cells by targeting p38 MAPK.
Objective To investigate whether Chlamydia pneumoniae alters the expression of TLR2 mRNA and p38 MAPK mRNA in mice with Chlamydia pneumoniae infection in TLR2-p38 MAPK-dependent pathway, subsequently leading to the release of cytokines. Methods Seventy-two male C3H/HeJmice were randomly divided into three groups as follow: a normal control group, a C. pneumoniae-inoculated group, and a C. pneumoniae-inoculated with SB203580 treatment group. The mice in the three groups were sacrificed on 1st, 4th, 7th, 14th day separately, and lung tissues were sampled for measurement. The expression changes of TLR2 mRNA and p38 MAPK mRNA in the mice lung tissue were measured by semi-quantitative RT-PCR. The concentrations of TNF-αin the lung tissue were measured by ELISA.Results Compared with those in the normal group, the expressions of TLR2 mRNA and p38MAPK mRNA in the lung tissue increased quickly after C. pneumoniae infection, which was especially obvious on day 4 and on day 7, the expression level of TLR2 mRNA on day 7 was markedly higher than that of the normal group [ ( 7. 24 ±1. 78) mg/L vs.( 0. 64 ±0. 14) mg/L, P lt;0. 05] ; The expression level of p38 MAPK mRNA on day 4 was markedly higher than that of the normal group [ ( 9. 267 ±1. 813) mg/L vs. ( 3. 734 ±0. 946) mg/L, P lt;0. 05] . After 14 days, C. pneumoniae infection of mice was attenuated, the concentration of TNF-α in the lung tissue increased, and was clearly higher than that of the normal control group, peaking on day 4 [ ( 77. 29 ±9. 66) pg/mg] . Treatment with SB203580 could effectively inhibit TLR2 mRNA and p38 MAPK mRNA expression in lung, which was especially obvious on day 4 and on day 7. The expression level of TLR2 mRNA on day 7 was ( 0. 269 ±0. 09) mg/L, and the expression level of p38 MAPK mRNA on day 7 [ ( 0. 002 ±0. 001) mg/L] was even more obviously attenuated, the concentration of TNF-α in the lung tissue markedly decreased when compared with that in the infected group, and its concentration on day 4 [ ( 25. 76 ±3. 49) pg/mg] lowered more clearly. Conclusions The alteration of TLR2-p38 MAPKdependent signal pathway in lungs is closely connected with Chlamydia pneumoniae infection. SB203580 treatment can effectively controll the elevation of TLR2 mRNA and p38 MAPK mRNA expressions in lung. It can effectively control the TLR2-MAPK signal transduction pathway.
【摘要】 目的 觀察機械通氣對黏蛋白（mucin，MUC）-5AC表達的影響及復方川貝精片的干預作用。 方法 新西蘭兔25只，6個月齡，雄性；隨機分為對照組、機械通氣12 h組及復方川貝精片低、中、高劑量組。收集支氣管灌洗液，分別采用實時熒光定量聚合酶鏈式反應法和酶聯免疫吸附試驗檢測支氣管灌洗液中p38 MAPK mRNA，MUC-5AC蛋白和mRNA的表達。 結果 機械通氣能增強MUC-5AC的分泌（Plt;0.05）；加用復方川貝精片能降低機械通氣后MUC-5AC蛋白和mRNA的表達（Plt;0.05）；復方川貝精片中、高劑量組與低劑量組比較，能降低機械通氣后MUC-5AC蛋白和mRNA的表達（Plt;0.05）。 結論 機械通氣能促進支氣管黏膜上皮細胞分泌MUC-5AC，復方川貝精片能抑制機械通氣所致MUC-5AC表達升高，其機制可能與其抑制p38 MAPK表達有關。【Abstract】 Objective To observe the effect of mechanical ventilation by breathing machine on the expression of mucin (MUC-5AC) and the interfering effect of compound tablet of fritillary bulb. Methods New Zealand Rabbits were randomly divided into control group, twelve-hour mechanical ventilation group, and low, medium and high-dose compound tablet of fritillary bulb group. Contents of p38 MAPK mRNA, MUC-5AC mRNA and protein in bronchial irrigating solution were detected by realtime RT-PCR and ELISA methods. Results Mechanical ventilation could increase the expression of MUC-5AC in bronchial irrigating solution (Plt;0.05). Compound tablet of fritillary bulb could decrease the expression of MUC-5AC mRNA and protein after mechanical ventilation (Plt;0.05). Compared with low-dose compound tablet of fritillary bulb group, the expression of MUC-5AC mRNA and protein was lower for the high and medium-dose groups (Plt;0.05). Conclusions Mechanical ventilation can promote the expression of MUC-5AC in bronchial endothelial cells, which can be suppressed by compound tablet of fritillary bulb. This may be due to the suppression effect of p38 MAPK expression.