Study On Apoptosis Of HBE Cells Induced By Uranium Dust

Objective: The aim of this study was to investigate apoptosis of human bronchialepithelial cells induced by uranium mine dust.Methods: MTT assay was performed to detect cell proliferation. After Haematoxylinand Under light microscopy observed eosin staining morphological chanes in HBEcell.The level of lactate dehydrogenase (LDH)、glutamic-oxaloacetic transaminase（GOT）and alkaline phosphatase (AKP) were erasured by spectrophotometer.AO/EB fluorescence staining detected cells apoptosis, the changes of cell cycle weredetected by FCM, immunocytochemistry detected the expression of apoptosis relatedproteins.Results:1. The cytotoxicity of HBE induced by uranium dustThe cytotoxicity after exposure to uranium dust for12h was detected by MTTassay. The results showed that the survival rate was decreased with the increase ofuranium dust dosage.HE staining showed that after being treated with uranium dust for12h, HBE cellsappeared morphological changes: cells were spindle shaped with uniform size incontrol group mostly. All of which were indicative of cell apoptosis.The level of LDH, AKP, GOT in the cell culture increased remarkably afterinduced by uranium mine dust. Uranium mine dust groups compared with controlgroup and differences were significant (P <0.01). There was significantly dose-effectrelationship between uranium mine dusts with LDH, AKP, GOT in a special range.2. Apoptosis of HBE cells induced by uranium dustThe AO/EB fluorescence stain assay showed after uranium dust treatment withdifferent concentrations, with the increase of exposure dose HBE cells demonstrateddecreased green fluorescence. Orange stain increased and even presented red necroticcells. Cell apoptosis rate was increased as exposure dose increased.HBE cells were stained with PI to analyze cell cycle by FCM. The result was that cells treated with exposure doses of uranium dust were observed cell arrest in G2/Mphase.The expression of apoptosis related proteins after exposure to uranium dust for12h was performed to detect by the immunocytochemical method. The results wasthat the expression of bax and bcl-2increased as exposure dose increased in exposuregroups where bcl-2/bax ratio decreased gradually. The expressions of cyt C, caspase-3and caspase-9were enhanced with the increase of uranium dust.Conclusions:1The cytotoxicity of HBE induced by uranium dust that proliferation of HBE cellscould be inhibited, HBE cells exhibited morphological changes and Cell membranewas damaged.2Uranium ore dust induced apoptosis in human bronchial epithelial cells that Cellcycle changes of HBE and the expression of apoptosis related proteins (bax、bcl-2、cyt C、caspase-3and caspase-9) after exposure to uranium dust was enhanced, thecaspase-9proteins increased significantly and apoptosis of HBE cells induced bymitochondrial pathway.