磷酸二酯酶抑制剂对慢性阻塞性肺疾病患者PBMC中IL-8mRNA表达的影响

目的:探讨磷酸二酯酶(PDE)抑制剂对慢性阻塞性肺疾病(COPD)患者外周血单个核细胞(PBMC)IL-8mRNA表达的影响及机制。方法:采集20例急性发作期COPD患者(A组)和15例正常人(B组)的PBMC。A组的每份PBMC分4组培养:A1组为空白对照,A2组和A3组分别加入100μmol/L及1mmol/L的非选择性PDE抑制剂茶碱,A4组加入选择性PDEⅣ抑制剂Rolipram。应用RT-PCR检测IL-8mRNA的表达,以免疫组化法检测NF-κB阳性细胞的百分率,用Westernblot检测I-κB蛋白的含量。结果:(1)A1组PB-MC中IL-8mRNA的表达及NF-κB阳性细胞的百分率,均显著高于B组;IκB的水平显著低于B组(P<0.01)。(2)与A1组比较,A2组和A3组的PB-MC中IL-8mRNA的表达无显著差异(P>0.05);A4组IL-8mRNA的表达明显下降(P<0.01)。(3)与A1组比较,A2组NFκB阳性细胞的百分率及IκB的水平无显著差异(P>0.05);而A3组的PBMC中NFκB阳性细胞的百分率下降(P<0.05),IκB蛋白的水平无显著变化(P>0.05)。A4组PB-MC中,NF-κB阳性细胞的百分率较A1组明显下降,I-κB蛋白的水平明显增加(P<0.01)。结论:COPD患者PBMC中IL-8mRNA的表达较正常增高,提示IL-8参与了COPD的发病过程;选择性PDEⅣ抑制剂Roli-pram可抑制IL-8基因的表达,其作用机制可能与NF-κB阳性细胞百分率的下降有关。非选择性PDE抑

Effect of phosphodiesterase inhibitor on expression of IL-8 mRNA in peripheral blood mononuclear cells from COPD patients

AIM: To explore the inhibitory mechanism of phosphodiesterase(PDE) inhibitor on expression of IL-8 mRNA in peripheral blood mononuclear cells (PBMCs) from chronic obstructive pulmonary disease(COPD) patients. METHODS: PBMCs isolated from 20 COPD patients and 15 healthy subjects were co-cultured with non-selective inhibitor theophylline or PDE type IV inhibitor Rolipram. The expression of IL-8 mRNA was assayed by RT-PCR. The expression of NF-kappaB was determined by immunocytochemical staining. The content of I-kappaB protein was detected by Western blot. RESULTS: The expression of IL-8 mRNA was elevated and the percentage of NF-kappaB nucleus positive cells was higher in COPD patients than in normal controls(P<0.01), while the expression of I-kappaB was lower in COPD patients (P<0.01). Theophylline of 1 mmol/L caused a decrease in the percentage of NF-kappaB nucleus positive cells (P<0.05). The expression of IL-8 mRNA and I-kappaB were not affected by theophylline at the dose of 100 micromol/L or 1 mmol/L. Rolipram inhibited the expression of IL-8 mRNA and the activation of NF-kappaB(P<0.05). CONCLUSION: The results indicated that IL-8 mRNA may play a pathogenic role in the development of COPD and that selective PDE type IV inhibitor Rolipram inhibit the expression of IL-8 mRNA via NF-kappaB.