Objective To detect the expression of single immunoglobin IL-1 receptor related protein ( SIGIRR) in normal human lung tissues, and study its changes in alveolar epithelial cell acutely injured by lipopolysaccharide ( LPS) . Methods Twenty samples of human normal lung tissue were collected during the lobectomies. The expression of SIGIRR was detected by immunohistochemistry, western blot and RT-PCR. The human type II alveolar epithelial cell acute injury model was established by stimulating A549 cells with LPS of a final concentration of 10 μg/mL. The cells were collected at 0, 3, 6, 12, and 24 hours after the stimulation. The changes of SIGIRR expression at the same time points were observed by western blot. The expression vector containing full-length SIGIRR cDNA was transfected transiently into A549 cells to induce SIGIRR overexpression. MTT assay was performed to measure the injury of A549 cells caused by LPS. Results The immunohistochemistry, western blot and RT-PCR showed that there was a high expression of SIGIRR in normal human lung tissues. The expression of SIGIRR was located in alveolar epithelial cells by immunohistochemistry. The expression of SIGIRR at 3, 6, and 12 hours was down-regulated after LPSstimulation and raised again at 24 hours to the baseline. MTT assay showed that SIGIRR overexpression substantially reduced the growth inhibition ratio of A549 cells after LPS stimulation. Conclusions Expression of SIGIRR in normal human lung tissues was confirmed by different detection methods. SIGIRR alleviates the injury of alveolar epithelial cells caused by LPS, implying SIGIRR might be involved in the regulationof acute lung injury mediated by LPS.
Objective To observe the effects of melatonin on lung injury and NDRG2 ( N-myc downstream-regulated gene 2) expression after intestinal ischemia-reperfusion ( I/R) .Methods 40 healthy SD rats were randomly assigned to a sham group, an I/R group, a high-dose melatonin group ( 10 mg/kg) , and a low-dose melatonin group ( l mg/kg) . The model of lung injury was established by superior mesenteric artery clamping/unclamping. 30 minutes before clamping, melatonin was administered intraperitoneally to the rats in two melatonin groups, and normal saline in same volume was administered to the rats in the I/R group and the shamgroup. Then superior mesenteric arteries of the rats in the I/R group and two melatonin groups were clamped for 60 minutes. 45 minutes after unclamping, right lung tissues were sampled for pathological examination and wet/dry ( W/D) ratio measurement. The rats in the sham group underwent sham operation without clamping. The expression of NDRG2 protein in the lung tissue was detected by immunohistochemistry and Western-blot. Results Compared with the sham group, hemorrhage and inflammation of lung tissues were observed. The W/D was obviously increased and the NDRG2 expression was significantly decreased in the I/R group. Compared with the I/R group, mild hemorrhage and inflammation changes of lung tissues were observed and the W/D was decreased while the NDRG2 protein expression was increased significantly in two melatonin groups. There was no significant difference between two melatonin groups. Conclusion Melatonin may relieve lung injury after intestinal ischemia-reperfusion through up-regulating NDRG2 expression.
Objective To explore the effectiveness of the transforming growth factor-β1(TGF-β1) and tumor necrosis factor-α(TNF-α) inducing human bronchial epithelial(HBE) cells to optimize epithelia-mesenchymal transformation(EMT) model. Methods Blank control, TGF-β1 10 ng/ml, TNF-α 10 ng/ml, TGF-β1 10 ng/ml+TNF-α 10 ng/ml induced human epithelial cells for 24 hours. Then the change of morphological alteration were observed by applying CCK8, cells migration assay and Western blot technique. Results When TGF-β1 plus TNF-α induced human epithelial cells for 24 hours, most of HBE cells traits changed including morphological alteration from cobblestone to fusiform, connection between cells vanishing, intercellular space broadening. In the experiments of checking cell migration capacity by the vitro scratch test, the group spacing was 420.06±10.38 μm in the blank control group, 499.86±34.00 μm in the TGF-β1 10 ng/ml group, 514.93±10.56 μm in the TNF-α 10 ng/ml group, 569.68±33.58 μm in the TGF-β1 10 ng/ml+TNF-α10 ng/ml group. TGF-β1 cooperated with TNF-α led to scratch spacing narrowing significantly. Western blot analysis showed that expression of E-cadherin and Vimentin varied significantly in the TGF-β1+TNF-α group. Conclusion Inducing human bronchial epithelial cell by TGF-β1 cooperated with TNF-α optimizes EMT model.