COPD患者early-EPCsβ_2-肾上腺素受体的表达及其对细胞迁移的影响~

Effect of β_2-adrenergic receptor expression on migration of early-EPCs in COPD patients

目的:探讨慢性阻塞性肺疾病(COPD)患者外周血中的早期内皮祖细胞(early-EPCs)是否表达β2-肾上腺素受体(β2AR)及其对细胞迁移的影响。方法:晨起从COPD患者与对照组抽取20 mL静脉血,用Ficoll密度梯度+磁珠分离法提取CD34^+细胞。通过Western blotting、RT-PCR及流式细胞术测定early-EPCs的β_2AR表达。体外培养early-EPCs,应用β_2AR的激动剂、抑制剂及下调β_2AR的表达量,通过Transwell法测定early-EPCs的迁移能力。结果:来自COPD患者的early-EPCs可见β_2AR mRNA及蛋白的表达强于对照组细胞(P<0.01)。两组细胞均表达β2AR,但COPD组明显高于对照组,流式细胞术分析两组的β2AR阳性细胞分别是82.9%和55.7%。外源性β2AR抑制剂、β2AR抗体及下调β_2AR的表达均可改善COPD患者early-EPCs的迁移能力。结论:β_2AR在COPD患者及对照组外周血中的early-EPCs均有表达。降低β_2AR的表达可影响COPD患者early-EPCs的迁移功能。

AIM：To investigate whether early endothelial progenitor cells （early-EPCs） expressβ2-adrenergic receptor （β2 AR） in the chronic obstructive pulmonary disease （ COPD） patients and the effect of β2 AR expression on the migration of early-EPCs.METHODS：Venous blood samples （20 mL） were obtained from antecubital vein of COPD pa-tients or healthy controls .Peripheral blood mononuclear cells were isolated by standard Ficoll gradient centrifugation , and purified by CD34 positive selection cocktail .The mRNA expression of β2 AR in the early-EPCs was detected by RT-PCR. The protein levels of β2 AR were assessed by Western blotting and flow cytometry .Chemotaxis was studied by Transwell as-say.Cultured early-EPCs were treated with ICI118551, norpinephrine （NE） or monoclonal antibody of β2AR （mAb-β2 AR） for 24 h.The number of migratory cells was counted under a light microscope .RESULTS：The level of β2 AR ex-pression in the COPD patients was higher than that in the controls .The number of migratory early-EPCs to stromal cell-de-rived factor 1αwas significantly improved by ICI 118551 compared with other COPD groups .When early-EPCs from the COPD patients or the controls were treated with different concentrations of mAb-β2 AR for 24 h, the number of migratory early-EPCs from the COPD patients and the controls treated with NE at concentration of 100 nmol/L was significantly re-duced.However, a marked decrease in the number of migratory early-EPCs from the COPD patients treated with NE was observed compared with control group .Before treated with ICI118551 or NE for 24 h, the early-EPCs were co-incubated with mAb-β2 AR for 40 min, and the number of migratory early-EPCs was not significantly different between COPD group and control group .Genetic down-regulation of β2 AR promoted the migration of early-EPCs in COPD group .CONCLU-SION：The level of β2 AR expression in the COPD patients is increased compared with the controls .The down-regulation ofβ2 AR improves the migration of early-EPCs.