Effect of cholecystokinin octapeptide on tumor necrosis factor α transcription and nuclear factor-κB activity induced by lipopolysaccharide in rat pulmonary interstitial macrophages

AIM: To elucidate the anti-inflammatory mechanism ofan intestinal neuropeptide, sulfated cholecystokininoctapeptide (sCCK-8), the effects of sCCK-8 onlipopolysaccharide (LPS)-induced tumor necrosis factorpulmonary interstitial macrophages (PIMs) werestudied.METHODS: PIMs from rat were stimulated with LPS(:1mg @ L-1) in the presence or absence of sCCK-8 (10-8-:10-6mol@ L-1) or/and CCK receptor antagonistproglumide (2 mg @ L-1). The expression of TNF-α mRNAwas assayed by reverse transcription polymerase chainreaction (RT-PCR) at 3h of the stimulation, and nuclearelectrophoretic mobility shift assay (EMSA) at 1 h ofat 30 min of the stimulation was detected by Westernblot.RESULTS: sCCK-8, at concentrations from 10-8 mol @ L-1to 10-6 mol @ L-1 obviously inhibited LPS-induced TNF-αdependent manner, P＜0.05, P＜0.01. Stimulation PIMsP＜0.01, which was elevated by sCCK-8, P＜0.05. Thewere attenuated by CCK receptor antagonistproglumide, P＜0.01.CONCLUSION: sCCK-8 inhibits LPS-induced TNF-α mRNAwhich is mediated through CCK receptors and inhibitinginflammatory mechanisms of sCCK-8.

AIM:To elucidate the anti-inflammatory mechanism of an intestinal neuropeptide,sulfated cholecystokinin octapeptide(sCCK-8),the effects of sCCK-8 on Iipopolysaccharide(LPS)-induced tumor necrosis factor α(TNF-α)mRNA expression and NF-κB activity in pulmonary interstitial macrophages(PIMs)were studied. METHODS:PIMs from rat were stimulated with LPS (1mg·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-a mRNA was assayed by reverse transcription polymerase chain reaction(RT-PCR)at 3h of the stimulation,and nuclear factor-κB(NF-κB)binding activity was analyzed by electrophoretic mobility shift assay(EMSA)at 1 h of stimulation.The IκB-α 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-α mRNA expression and NF-κB binding activity in a dose- dependent manner,P<0.05,P<0.01.Stimulation PIMs with LPS resulted in a reduction of IκB-α protein level, P<0.01,which was elevated by sCCK-8,P<0.05.The effects of sCCK-8 on NF-κB activity and IκB protein level were attenuated by CCK receptor antagonist proglumide,P<0.01. CONCLUSION:sCCK-8 inhibits LPS-induced TNF-a mRNA expression by regulating NF-κB activity in rat PIMs, which is mediated through CCK receptors and inhibiting IκB-α degradation.This represents one of the anti- inflammatory mechanisms of sCCK-8.