title: [Hypoxia combined with TNF-α induces apoptosis of cultured human pulmonary microvascular endothelial cells via activation of the STAT3 rather than ERK1/2 signaling pathway].
abstract: Objective To explore the effect of combined hypoxia and tumor necrosis factor α (TNF-α) on the apoptosis of human pulmonary microvascular endothelial cells (HPMVECs) and the involved signaling pathway mechanism. Methods Some HPMVECs were treated with hypoxia within 6, 12, or 24 hours, and the other cells were treated with TNF-α at the concentrations of 10, 20, 50, or 100 ng/mL. Cell activity was determined by MTT assay in each group to determine the best combined stimulatory conditions. Under the optimal costimulatory condition, the activity of caspase-3 was detected by flow cytometry, annexin V-FITC/PI double staining combined with flow cytometry was used to detect the apoptosis, Western blotting was performed to test the level of phosphorylated signal transducer and activator of transcription 3 (pSTAT3) and phosphorylated extracellular signal-regulated kinase 1/2 (pERK1/2). Results The cell activity was the lowest in 24-hour hypoxia group and 100 ng/mL TNF-α group. Therefore, we confirmed the combination of hypoxia for 24 hours and 100 ng/mL TNF-α as the costimulatory conditions. The caspase-3 activity and apoptosis rate in the combined treatment group were higher, compared with the other groups. The expression of pSTAT3, rather than pERK1/2, increased in the combined treatment group, compared with the control group. Moreover, the STAT3 inhibitor S3I-201 reduced the apoptosis rate in the combined treatment group. Conclusion Combined hypoxia and TNF-α could promote HPMVEC apoptosis by activating STAT3 rather than ERK1/2.
authors.affiliation: Department of Respiratory Diseases, Foshan First People's Hospital, Foshan 528000, China.
authors.forename: Shengjun
authors.initials: S
authors.lastname: Ji
authors.affiliation: Department of Respiratory Diseases, Foshan First People's Hospital, Foshan 528000, China.
authors.forename: Yeliang
authors.initials: Y
authors.lastname: Wen
authors.affiliation: Department of Respiratory Diseases, Foshan First People's Hospital, Foshan 528000, China.
authors.forename: Qiting
authors.initials: Q
authors.lastname: Lai
authors.affiliation: Department of Respiratory Diseases, Foshan First People's Hospital, Foshan 528000, China.
authors.forename: Minjing
authors.initials: M
authors.lastname: Li
authors.affiliation: Department of Respiratory Diseases, Foshan First People's Hospital, Foshan 528000, China. *Corresponding author, E-mail: zhangpf@163.com.
authors.forename: Peifang
authors.initials: P
authors.lastname: Zhang
mesh_terms: D000636:Aminosalicylic Acids / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D001557:Benzenesulfonates / Q000494:pharmacology; D015153:Blotting, Western; D053148:Caspase 3 / Q000378:metabolism; D015687:Cell Hypoxia; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D008168:Lung / Q000098:blood supply; D020935:MAP Kinase Signaling System / Q000187:drug effects; D055806:Microvessels / Q000166:cytology; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D050796:STAT3 Transcription Factor / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D000636:Aminosalicylic Acids; D001557:Benzenesulfonates; C520337:NSC 74859; D050796:STAT3 Transcription Factor; D014409:Tumor Necrosis Factor-alpha; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D053148:Caspase 3