ObjectiveTo observe the effects of Th9 cell relative factors, including PU.1, interferon regulatory factor 4 (IRF4) and interleukin 4 (IL-4), in rats with pulmonary fibrosis. MethodsNinety SD rats were randomly divided into 3 groups, ie. a normal group, a pulmonary fibrosis group, and a dexamethasone treatment group, with 30 rats in each group. Ten rats in each group were sacrificed respectively on 7th, 14th, 28th days. Model rats were induced by injecting bleomycin into trachea. Real-time PCR was applied to detect mRNA expression of PU.1 and IRF4 in bronchoalveolar lavage fluid. IL-4 in the peripheral blood was measured by ELISA. ResultsIn the normal group, the lung tissue was normal without inflammatory reaction and fibrosis at any time points. In the pulmonary fibrosis group, at the early stage the lung tissue showed alveolar inflammation with a large number of macrophages and other inflammatory cells infiltratation in the pulmonary interstitial and alveolar cavity; on 14th day, part of the alveolar structure disappeared, inflammatory cells infiltrated slightly, while the alveolar septum was mildly widened and fibroblasts proliferated; on 28th day, alveolar structure was destructed, partial alveolar walls were collapsed, alveolar septuml was significantly widened, extracellular matrix was hyperplastic, a wide range of fibrosis occured. In the dexamethasone treatment group, the alveolar structure exsisted completely, and the inflammatory cell infiltration, widened alveolar septum and fibrosis were significantly lighter than those in the pulmonary fibrosis group. PU.1 mRNA was significantly lower in the pulmonary fibrosis group compared with the normal group. Compared with the pulmonary fibrosis group, PU.1 mRNA were lower on 14th day and 28th day in the dexamethasone treatment group (P < 0.05). PU.1 mRNA increased from 7th day, reached peak on 14th day, and declined on 28th day. IRF4 mRNA was significantly lower in the pulmonary fibrosis group compared with the normal group. Compared with the pulmonary fibrosis group, IRF4 mRNA was lower on 28th day in the dexamethasone treatment group (P < 0.05). There was a positive correlation between the content of IRF4 mRNA and IL-4 on 14th day in the pulmonary fibrosis group (r=0.044, P < 0.05). ConclusionPU.1 and IRF4 play a role in inflammation leading to pulmonary interstitial fibrosis, and IL-4 may regulate Th9 cells through activating IRF4.
Objective To study the expression of interleukin (IL)-37 and related factors in lung tissue of rats with acute lung injury, and explore the role and significance of IL-37 in acute lung injury so as to understand the pathogenesis of acute lung injury. Methods Forty-five clean-grade Wistar rats were randomly divided into a healthy control group, a bleomycin group and a dexamethasone treatment group, with 15 rats in each group. The rats in the bleomycin group and the dexamethasone group were treated with bleomycin at a dose of 4 mg/kg by intratracheal administration. The healthy control group was given the same volume of saline as control. The dexamethasone treatment group was injected with dexamethasone 3 mg/kg intraperitoneally twice a day on the basis of acute lung injury. The healthy control group and the bleomycin group were injected intraperitoneally with normal saline as control. The rats in each group were sacrificed at 7, 14 and 28 days after modeling. The histopathological changes of lung tissue were evaluated by HE staining. The levels of IL-37 in lung homogenate and tumor necrosis factor (TNF)-α in serum were measured. The expression of IL-18 mRNA in lung tissue was detected by RT-PCR. Results Pathological morphology showed that the lung tissue of the healthy control group was complete, no inflammatory and fibrotic changes at all time points. The lung tissues of the bleomycin group and the dexamethasone group manifested with acute alveolitis firstly and thus developed fibrosis changes lately, and the changes in the dexamethasone group were more slightly than those in the bleomycin group. The contents of IL-37 and TNF-α and the expression of IL-18 mRNA in the bleomycin group and the dexamethasone group reached to the highest point on the 7th day, and then decreased, but were significantly higher than those of the healthy control group on the 28th day (all P<0.05). Conclusions IL-37 plays an important role in the pathogenesis of acute lung injury in rats. This effect may be related to the regulation of IL-18 and TNF-α transduction.
ObjectiveTo investigate the therapeutic effects of different doses of tanshinone ⅡA microemulsion on radioactive lung injury. MethodsSeventy-two Wistar rats were randomly divided into a healthy control group,a model group,a liposome microemulsion treatment group,a tanshinone ⅡA microemulsion high-dose group,a tanshinone ⅡA microemulsion middle-dose group,and a tanshinone ⅡA microemulsion low-dose group.Radiation-induced lung injury model was established by irradiation of radiotherapy instrument.In addition to the control group,other groups received 6MV X radiation with one dosage of 22Gy.Four rats in each group were sacrificed on 7th,14th,and 28th day,respectively.Lung tissues were sampled to analyze the pathological changes by HE staining and the Smad7 mRNA expression by RT-PCR.The level of glutathione(GSH)in peripheral blood was determined by ultraviolet spectrophotometric method. ResultsIn the model group and four treatment groups,lung tissue biopsy showed the pathological changes gradually from pulmonary alveolitis to fibrosis.The level of Smad7 mRNA in lung tissue and GSH in peripheral blood were higher in the high-dose group,the middle-dose group and the low-dose group than those in the model group at all time points(P<0.05),and were highest in the high-dose group.There was no significant differences in the level of Smad7 mRNA in lung tissue and GSH in peripheral blood between the liposome microemulsion treatment group and the middle-dose group. ConclusionTanshinone ⅡA microemulsion has treatment effect on lung injury in a dose dependent manner.