Tumor necrosis factor-alpha induces mucin hypersecretion and MUC-2 gene expression by human airway epithelial cells.
Tumor necrosis factor-alpha (TNF-alpha) is a multifunctional, proinflammatory cytokine that is capable of activating a diverse number of target genes within multiple cell types. Little information is known regarding the role of TNF-alpha in the regulation of human airway mucin hypersecretion and MUC-2 gene expression. To assess the effect of TNF-alpha exposure on mucin secretion, human airway organ cultures and primary cultures of human airway epithelial cells were stimulated with 20 ng/ml of recombinant human TNF-alpha and mucin secretion quantitated by an enzyme-linked immunosorbent assay using a specific monoclonal antibody directed against human airway mucin. Significant increases in mucin secretion from human airway organ cultures were initially detected at 1 h, peaked at 8 h, and persisted for 24 h. The TNF-alpha-mediated mucin hypersecretion at 8 h was concentration dependent. Significant increases in mucin secretion from primary cultures of human airway epithelial cells were initially detected at 4 h, peaked at 48 h, and persisted for 72 h after stimulation with 20 ng/ml of recombinant human TNF-alpha. The TNF-alpha-mediated mucin hypersecretion at 48 h from primary cultures of human airway epithelial cells was inhibited by coincubation with soluble 55 kD, type I TNF receptors. Using reverse transcription-polymerase chain reaction and a human pulmonary mucoepidermoid carcinoma cell line (NCI-H292), increases in MUC-2 steady-state mRNA levels were first detectable after 30 min of TNF-alpha stimulation and persisted for 24 h. Cycloheximide did not inhibit TNF-alpha-mediated MUC-2 mRNA expression at 1 h, suggesting that new protein translation was not required.(ABSTRACT TRUNCATED AT 250 WORDS)
Levine
S J
SJ
Critical Care Medicine Department, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland 20892-1662.
Larivée
P
P
Logun
C
C
Angus
C W
CW
Ognibene
F P
FP
Shelhamer
J H
JH
D000199:Actins / Q000235:genetics; D001483:Base Sequence; D002478:Cells, Cultured; D017931:DNA Primers / Q000235:genetics; D004848:Epithelium / Q000187:drug effects / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D008969:Molecular Sequence Data; D055262:Mucin-2; D009077:Mucins / Q000235:genetics* / Q000378:metabolism*; D009924:Organ Culture Techniques; D011994:Recombinant Proteins / Q000494:pharmacology; D012137:Respiratory System / Q000187:drug effects* / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D000199:Actins; D017931:DNA Primers; C524625:MUC2 protein, human; D055262:Mucin-2; D009077:Mucins; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha