ABSTRACT
Objective:To investigate the effects and regulation mechanism of lipid-associated membrane proteins (LAMPs) derived from Mycoplasma pneumoniae( Mp) on the expression of quinine oxidoreductase 1 (NQO-1) in human monocyte cell line THP-1 cells, and to know the effect of NQO-1 to interleukin 8 secretion in LAMPs stimulated cells, so as to better understand the regulation mechanism upon Mp infection. Methods:Mp were cultivated and the precipitate was collected to extract LAMPs. The cytotoxicity of LAMPs to THP-1 cells was analyzed by using CCK8 test. THP-1 cells were cultured in vitro with different concentrations of LAMPs for different times, and the expression of NQO-1 protein was detected by Western blot. Nrf2 siRNA was used to investigate the role of Nrf2 in NQO-1 expression in LAMPs induced cells, and NQO-1 inhibitor Diminutol was performed to test whether they blocked interleukin 8 (IL-8) secretion when treated with LAMPs in THP-1 cells. Results:LAMPs extracted from Mp had no cytotoxicity to THP-1 cells. The expression of NQO-1 protein in LAMPs-stimulated THP-1 cells showed a dose-dependent and time-dependent manner. The production of NQO-1 protein reached peaks when treated with 5.0 μg/ml or 7.5 μg/ml of LAMPs for 12 h. Silencing of Nrf2 by siRNA significantly decreased NQO-1 production, and blocking NQO-1 by Dim increased the level of IL-8 in LAMPs-stimulated cells. Conclusions:LAMPs derived from Mp induced the expression of NQO-1 protein in THP-1 cells via Nrf2, and NQO-1 can inhibit IL-8 secretion in LAMPs stimulated monocytes.
ABSTRACT
Objective To observe the dynamic changes of heme oxygenase 1,NAD(P)H:quinine oxidoreductase 1 and Nuclear factor-E2-related factor 2 in the lung tissue of acute H2S-intoxicated rats and intervention effects of ulinastratin(UTI).Methods A total of 96 SD rats of clean grade were divided randomly(random number)into four groups:normal control group(NS group,n =8),UTI control group(UTI group,n =8),H2S-intoxicated model group(H2S group,n =40,rats were exposed to H2S(200 × 10-6)for 1 h to establish the H2S-intoxicated model)and UTI treatment group(H2S +UTI group,n =40,rats were intraperitoneal injected with the dose of UTI 105 U/kg).H2S group and H2S + UTI group were sacrificed 2,6,12,24 and 48 h after modeling.The activity and mRNA expression of HO-1 and NQO-1 in the lung tissue were measured by ELISA and RT-PCR methods,and the expression of Nrf2 mRNA and protein in the lung tissue was detected by RT-PCR and Western Blot methods.Pathological changes of lung tissue were observed by lightmicroscope and the lung injury score was used to evaluate inhalation injury.Results The pulmonary HO-1 activity and mRNA expression in rats of H2S group at 2,6,12 h(P ＜ 0.01)after intoxication were markedly increased than that in NS group:In comparison with H2S group,the pulmonary HO-1 activity and mRNA expression increased at 6,12,24,48 h(P ＜0.01).The pulmonary NQO-1 activity and mRNA expression in rats of H2S group at 2,6,12,24 h(P＜ 0.01)after intoxication were markedly increased than that in NS group; In comparison with H2S group,the pulmonary NQO-1 activity and mRNA expression increased at 6,12,24,48 h(P ＜ 0.01).The pulmonary Nrf2 mRNA and protein expression in rats of H2S group at 2,6,12 h(P ＜0.01 or P ＜0.05)after modeling were markedly increased than that in NS group and reached peak 2 hour after modeling; In comparison with H2S group,the pulmonary Nrf2 mRNA and protein expression increased at 6,12,24,48 h(P ＜0.01).At 24 h after modeling,the degree of lung damage were also decreased in H2S group compared with H2S + UTI group in the lightmicroscope.Histopathological examination showed that the degree of lung injury in H2S + UTI group was less severe than that in H2S group especially in the 12,24 and 48 h (P ＜0.01).Conclusions HO-1,NQO-1 and Nrf2 are involved in the pathogenesis of acute lung injury induced by H2S-intoxicated in rats.UTI may improve the imbalance in redox and activate HO-1,NQO-1 and Nrf2 can reduce lung injury and protect the lung injury induced by H2S in rats.