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 观察机械通气对黏蛋白（mucin，MUC）-5AC表达的影响及复方川贝精片的干预作用。 方法 新西兰兔25只，6个月龄，雄性；随机分为对照组、机械通气12 h组及复方川贝精片低、中、高剂量组。收集支气管灌洗液，分别采用实时荧光定量聚合酶链式反应法和酶联免疫吸附试验检测支气管灌洗液中p38 MAPK mRNA，MUC-5AC蛋白和mRNA的表达。 结果 机械通气能增强MUC-5AC的分泌（Plt;0.05）；加用复方川贝精片能降低机械通气后MUC-5AC蛋白和mRNA的表达（Plt;0.05）；复方川贝精片中、高剂量组与低剂量组比较，能降低机械通气后MUC-5AC蛋白和mRNA的表达（Plt;0.05）。 结论 机械通气能促进支气管黏膜上皮细胞分泌MUC-5AC，复方川贝精片能抑制机械通气所致MUC-5AC表达升高，其机制可能与其抑制p38 MAPK表达有关。【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.
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.