title: Nuclear respiratory factor-1 is involved in mitochondrial dysfunction induced by benzo(a)pyrene in human bronchial epithelial cells.
abstract: In this study, we investigated the role of nuclear respiratory factor-1(NRF-1) in benzo(a)pyrene (BaP)-induced mitochondrial events in human bronchial epithelial cells (16HBE). Cytotoxicity was determined with MTT assay, and apoptosis was measured by flow cytometry. The results showed that BaP inhibited cell proliferation in a dose-dependent manner and induced apoptosis in 16HBE cells. Time-dependent reactive oxygen species (ROS) generation induced by BaP was observed in 16HBE cells. The loss of mitochondrial membrane permeability transition (MPT) was obtained by a laser scanning confocal microscope, and the decreasing ATP level was detected by a Cell-Titer-Glo(®) Luminescent Cell Viability Assay. Results of western blotting assay revealed that both NRF-1 and mitochondrial transcription factor A (mtTFA) decreased in 12-μM BaP-treated cells at both 12 and 24 hr. The results of RT-PCR indicate that NRF-1 and mtTFA mRNA in 16HBE cells were not changed after BaP treatment 12 or 24 hr. Down-regulation of NRF-1 by shRNA further reduced the loss of MPT and increased ROS generation in response to BaP treatment. Therefore, our results demonstrate that NRF-1 is responsible for BaP-induced mitochondrial dysfunction in 16HBE cells and associated with the level of mtTFA protein, loss of MPT and ROS overproduction.
authors.affiliation: Department of Prevention, Tongji University School of Medicine, Shanghai, China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Zhang
authors.forename: Yan
authors.initials: Y
authors.lastname: Bao
authors.forename: Jue
authors.initials: J
authors.lastname: Li
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis; D017209:Apoptosis / Q000187:drug effects; D001564:Benzo(a)pyrene / Q000633:toxicity*; D001980:Bronchi / Q000166:cytology / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000032:analysis; D004847:Epithelial Cells / Q000187:drug effects; D006801:Humans; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects* / Q000502:physiology; D024101:Mitochondrial Proteins / Q000032:analysis; D051266:Nuclear Respiratory Factor 1 / Q000032:analysis / Q000037:antagonists & inhibitors / Q000502:physiology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D014157:Transcription Factors / Q000032:analysis
chemical_list: D004268:DNA-Binding Proteins; D024101:Mitochondrial Proteins; C495633:NRF1 protein, human; D051266:Nuclear Respiratory Factor 1; D017382:Reactive Oxygen Species; C499631:TFAM protein, human; D014157:Transcription Factors; D001564:Benzo(a)pyrene; D000255:Adenosine Triphosphate