Effect of cholecystokinin octapeptide on tumor necrosis factor alpha transcription and nuclear factor-kappaB activity induced by lipopolysaccharide in rat pulmonary interstitial macrophages.
OBJECTIVE
To elucidate the anti-inflammatory mechanism of an intestinal neuropeptide, sulfated cholecystokinin octapeptide (sCCK-8), the effects of sCCK-8 on lipopolysaccharide (LPS)-induced tumor necrosis factor alpha (TNF-alpha) mRNA expression and NF-kappaB activity in pulmonary interstitial macrophages (PIMs) were studied.


METHODS
PIMs from rat were stimulated with LPS (1 mg.L(-1)) in the presence or absence of sCCK-8 (10(-8)-10(-6)mol.L(-1)) or/and CCK receptor antagonist proglumide (2 mg.L(-1)). The expression of TNF-alpha mRNA was assayed by reverse transcription polymerase chain reaction (RT-PCR) at 3h of the stimulation, and nuclear factor-kappaB (NF-kappaB) binding activity was analyzed by electrophoretic mobility shift assay (EMSA) at 1 h of stimulation. The IkappaBalpha protein level in the cytoplasma at 30 min of the stimulation was detected by Western blot.


RESULTS
sCCK-8, at concentrations from 10(-8) mol.L(-1) to 10(-6) mol.L(-1) obviously inhibited LPS-induced TNF-alpha mRNA expression and NF-kappaB binding activity in a dose-dependent manner, P<0.05, P<0.01. Stimulation PIMs with LPS resulted in a reduction of IkappaBalpha protein level, P<0.01, which was elevated by sCCK-8, P<0.05. The effects of sCCK-8 on NF-kappaB activity and IkappaB protein level were attenuated by CCK receptor antagonist proglumide, P<0.01.


CONCLUSIONS
sCCK-8 inhibits LPS-induced TNF-alpha mRNA expression by regulating NF-kappaB activity in rat PIMs, which is mediated through CCK receptors and inhibiting IkappaB-alpha degradation. This represents one of the anti-inflammatory mechanisms of sCCK-8.
Cong
Bin
B
Department of Pathophysiology, Hebei Medical University, Shijiazhuang 050017, Hebei Province, China. congbinbc@sina.com
Li
Shu-Jin
SJ
Yao
Yu-Xia
YX
Zhu
Gui-Jun
GJ
Ling
Yi-Ling
YL
D000818:Animals; D004268:DNA-Binding Proteins / Q000378:metabolism; D005260:Female; D020672:I-kappa B Proteins; D066298:In Vitro Techniques; D007249:Inflammation / Q000517:prevention & control; D008070:Lipopolysaccharides / Q000633:toxicity; D016676:Macrophages, Alveolar / Q000187:drug effects / Q000378:metabolism; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012844:Sincalide / Q000494:pharmacology*; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics*
D004268:DNA-Binding Proteins; D020672:I-kappa B Proteins; D008070:Lipopolysaccharides; D016328:NF-kappa B; C000606206:Nfkbia protein, rat; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D000072000:NF-KappaB Inhibitor alpha; D012844:Sincalide