Tumor necrosis factor-alpha-induced secretion of RANTES and interleukin-6 from human airway smooth-muscle cells. Modulation by cyclic adenosine monophosphate.
Although 3':5' cyclic adenosine monophosphate (cAMP) is known to modulate cytokine production in a number of cell types, little information exists regarding cAMP-mediated effects on this synthetic function of human airway smooth-muscle (HASM) cells. We examined the effect of increasing intracellular cAMP concentration ([cAMP](i)) on tumor necrosis factor (TNF)-alpha-induced regulated on activation, normal T cells expressed and secreted (RANTES) and interleukin (IL)-6 secretion from cultured HASM cells. Pretreatment of HASM with prostaglandin (PG) E(2), forskolin, or dibutyryl cAMP inhibited TNF-alpha-induced RANTES secretion but increased TNF-alpha-induced IL-6 secretion. Moreover, stimulation with PGE(2), forskolin, or dibutyryl cAMP alone increased basal IL-6 secretion in a concentration-dependent manner. SB 207499, a specific phosphodiesterase type 4 inhibitor, augmented the inhibitory effects of PGE(2) and forskolin on TNF-alpha-induced RANTES. Collectively, these data demonstrate that increasing [cAMP](i) in HASM effectively increases IL-6 secretion but reduces RANTES secretion promoted by TNF-alpha. Reverse transcriptase/polymerase chain reaction and ribonuclease protection assays suggested that these opposite effects of increased [cAMP](i) on TNF-alpha- induced IL-6 and RANTES secretion may occur at the transcriptional level. Accordingly, we examined the effects of TNF- alpha and cAMP on the regulation of nuclear factor (NF)-kappaB, a transcription factor known to modulate cytokine synthesis in numerous cell types. Stimulation of HASM cells with TNF-alpha increased NF-kappaB DNA-binding activity. However, increased [cAMP](i) in HASM neither activated NF-kappaB nor altered TNF-alpha- induced NF-kappaB DNA-binding activity. These results were confirmed using a NF-kappaB-luciferase reporter assay. Together, our data suggest that TNF-alpha-induced IL-6 and RANTES secretion may be associated with NF-kappaB activation, and that inhibition of TNF-alpha-stimulated RANTES secretion and augmentation of IL-6 secretion by increased [cAMP](i) in HASM cells occurs via an NF-kappaB-independent mechanism.
Ammit
A J
AJ
Pulmonary Division, Department of Medicine, University of Pennsylvania, Philadelphia 19104, USA.
Hoffman
R K
RK
Amrani
Y
Y
Lazaar
A L
AL
Hay
D W
DW
Torphy
T J
TJ
Penn
R B
RB
Panettieri
R A
RA
D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000037:antagonists & inhibitors; D003994:Bucladesine / Q000494:pharmacology; D002478:Cells, Cultured; D018946:Chemokine CCL5 / Q000235:genetics / Q000378:metabolism*; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; D003509:Cyclohexanecarboxylic Acids / Q000494:pharmacology; D015232:Dinoprostone / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics / Q000378:metabolism*; D009130:Muscle, Smooth / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D016328:NF-kappa B / Q000187:drug effects / Q000378:metabolism; D009570:Nitriles; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D014132:Trachea / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D018946:Chemokine CCL5; D003509:Cyclohexanecarboxylic Acids; D015850:Interleukin-6; D016328:NF-kappa B; D009570:Nitriles; D010726:Phosphodiesterase Inhibitors; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D005576:Colforsin; D003994:Bucladesine; C433247:Cilomilast; D000242:Cyclic AMP; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; D015232:Dinoprostone