Study On The Lung Injury Induced By Quinones 1,2-naphthoquinone And 9,10-phenanthrenequinone

Diesel exhaust particulates (DEP) is a major component of atmospheric pollution in the urban areas. the chemicals 1,2-naphthoquinone(1,2-NQ) and 9,10-phenanthrenequinone(PQ) are the main quinones in DEP, which can exacerbate various respiratory diseases. But it is not well clear that how to induce the lung damage by 1,2-NQ and PQ. In this study, first, lung histopathological and related hematological examinations were detected when intratracheal administration of 1,2-NQ and PQ. Second, influence on cell apoptosis and death induced by 1,2-NQ and PQ were studied. Last, relative expressions of TNF-α, IL-1β and MIP-1α were also detected by qt-PCR.Part one:male ICR mices,4-6 weeks of age, approximately 20 g weight, were performed in vivo. dU937 cells and A549 cells were utilized in vitro. The animals were randomly devided into three groups and anesthetized isoflurance, then challenged with 1,2-NQ and PQ in experimental groups or PBS in control group. Three mices were selected for samples including blood and lung tissues at 24h、48h and 72h in each group, with hematologic and histopathological examination. Part two:A549 cells and U937 cells were cultured in 24-well plates respectively and exposed to 1,2-NQ or PQ. Apoptosis and death were simultaneously detected. Part three:A549 cells and U937 cells seeded in 6-well plates respectively and cultured with LPS for 3 h, then exposed to 1,2 NQ and PQ. Cells were collected for RNA extraction. Relative gene expression levels of TNF-α、IL-1β and MIP-1α were detected by qt-PCR. Results are as follows:1. Histopathological examination of the pulmonary tissue:The lung tissue of control group was intact, and no lung injury was found. Compared with the control group, tissue structure of 1,2-NQ group showed that the dilation and congestion of pulmonary interstitial capillaries.accompanied by inflammatory cells infiltration and alveolar wall swelling. Tissue structure of PQ group showed that the dilation and congestion of pulmonary interstitial capillaries, accompanied by inflammatory cells infiltration and alveolar wall swelling, alveolar rupture and partly fusion. The results of haematology showed that, compared with the control group, the count of WBC, lymphocyte, and neutrophils were significantly increased in 1,2-NQ group (P<0.05). Compared with the control group, there was no significant change in the hematology test in the PQ group(P>0.05).2. Death rate of A549 cells treated by 1,2-NQ increased significantly in a dose-time-dependent(P<0.01), and the apoptosis rate also significantly increased, compared with the control group(P<0.05 or P<0.01). Death rate of A549 cells treated by PQ, ncreased significantly in a dose-time-dependent manner(P<0.01), and the apoptosis rate significantly increased than the control group in 24h. dU937 cells treated by 1,2-NQ, apoptosis rate and cell death rate was increased significantly in a dose-time-dependent (P<0.05 or P<0.01). dU937 cells treated by PQ, apoptosis rate and cell death rate was increased significantly in a dose-time-dependent (P<0.05 or P<0.01).3. There were no significantly change in the mRNA relative expressions of TNF-α、IL-1β and MlP-la of A549 cells treated by 1,2-NQ, compared to the control group(P>0.05). Cells were cultured with LPS and the mRNA relative expression of TNF-a and IL-1β increased significantly in dose-time-dependent, compared to the control group. No significant changes were detected in the mRNA relative expression of TNF-a、IL-1β and MIP-1α of A549 cells treated by PQ, compared to the control group(P>0.05). When cells were cultured with LPS, the mRNA relative expression of TNF-α、IL-1β and MIP-1α was increased (P<0.01). The mRNA relative expression of IL-1β and MIP-1α of dU937 cells treated by 1,2-NQ, decreased significantly compared to the control group(P<0.01 or P<0.05). When cultured with LPS, the mRNA relative expression of IL-1β and MIP-1αdicreased significantly in dose-time-dependent (P<0.01 or P<0.05). No significant changes of the mRNA relative expression of TNF-α、 IL-lβ and MIP-1α of dU937 cells treated by PQ were detected, compared to the control group(P> 0.05). When cultured with LPS, the mRNA relative expression of TNF-α, IL-1β andMIP-1α increased significantly in the low dose group(P<0.01). With the increase of PQ concentration, the mRNA relative expression of TNF-α、IL-1β and MIP-1α decreased significantly in a dose-time-dependent.Conclusion:1,2-NQ and PQ can induce the injury to lungs, trigger apoptosis and cell death, regulate the synthesis and release of inflammatory cytokines, and aggravate lung injury.