Regulation of surfactant proteins A and B by TNF-alpha and phorbol ester independent of NF-kappa B.
Acute lung inflammation is complicated by altered pulmonary surfactant phospholipid and protein composition. The proinflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) and the phorbol ester 12-O-tetradecanoyl phorbol-13-acetate (TPA) inhibit expression of surfactant-associated proteins A and B (SP-A and SP-B), both important for normal surfactant function. The transcription factor nuclear factor-kappa B (NF-kappa B) frequently mediates regulation of gene expression by TPA and TNF-alpha. In the present study, electrophoretic mobility shift assays (EM-SAs) and pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF-kappa B activation, were utilized to determine the role of NF-kappa B activation in TPA and TNF-alpha inhibition of the surfactant proteins in NCI-H441 cells. Pentoxifylline (PTX), which inhibits TNF-alpha cellular effects without preventing NF-kappa B activation, was also tested. By EMSA, TPA and TNF-alpha increased nuclear NF-kappa B binding activity in temporally distinct patterns. PDTC decreased TPA- and TNF-alpha-induced NF-kappa B binding activity but did not limit their inhibition of SP-A and SP-B mRNAs. PDTC independently decreased both SP-A and SP-B mRNAs. PTX partially reversed TNF-alpha-but not TPA-mediated inhibition of SP-A and SP-B mRNAs without altering NF-kappa B binding. The effects of PDTC and PTX on NF-kappa B and the surfactant proteins suggest that NF-kappa B activation does not mediate TPA or TNF-alpha inhibition of SP-A and SP-B mRNA accumulation.
Pryhuber
G S
GS
Department of Pediatrics, Strong Children's Research Center, University of Rochester Medical Center, New York 14642, USA.
Khalak
R
R
Zhao
Q
Q
D000818:Animals; D018931:Antineoplastic Agents, Hormonal / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D001667:Binding, Competitive; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology; D006023:Glycoproteins / Q000096:biosynthesis*; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010431:Pentoxifylline / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D011510:Proteolipids / Q000096:biosynthesis*; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000096:biosynthesis*; D011759:Pyrrolidines / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D013859:Thiocarbamates / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D018931:Antineoplastic Agents, Hormonal; D000975:Antioxidants; D006023:Glycoproteins; D016328:NF-kappa B; D010726:Phosphodiesterase Inhibitors; D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants; D011759:Pyrrolidines; D013859:Thiocarbamates; D014409:Tumor Necrosis Factor-alpha; C020972:pyrrolidine dithiocarbamic acid; D003907:Dexamethasone; D013755:Tetradecanoylphorbol Acetate; D010431:Pentoxifylline