地塞米松对哮喘小鼠气道平滑肌细胞中胸腺活化调节趋化因子表达的影响

目的探讨胸腺活化调节趋化因子(TARC)在哮喘小鼠气道平滑肌细胞中的表达及地塞米松对TARC的影响。方法 36只小鼠随机分为对照组(A组)、哮喘模型组(B组)、地塞米松治疗组(C组),每组12只。以卵白蛋白OVA和氢氧化铝混悬液致敏及OVA激发建立哮喘小鼠模型。行支气管肺泡灌洗液(BALF)沉渣白细胞及嗜酸性粒细胞(EOS)计数,HE染色观察肺组织病理改变,应用酶联免疫吸附实验测定血清及BALF中TARC、IL-4的浓度,并用免疫组织化学的方法测定气道平滑肌细胞中TARC蛋白的表达量。结果 B组白细胞及EOS计数明显高于A、C组(P<0.01),C组EOS计数高于A组(P<0.05)。B组血清及BALF中TARC及IL-4的浓度显著高于A、C组(P<0.01);C组血清、BALF中TARC的浓度低于B组(P<0.01)。B组气道平滑肌细胞中TARC蛋白表达量较A、C组显著增高(P<0.01)。小鼠血清、BALF中TARC浓度与IL-4浓度呈正相关(r=0.669、0.845,P均<0.01)。结论 TARC在哮喘组小鼠肺组织气道平滑肌细胞中的蛋白表达量较正常组明显增多,地塞米松可能通过减少IL-4的分泌从而抑制TARC的表达。

Influence of Dexamethasone on thymus activation regulated chemokine in asthma smooth muscle cells of asthmatic mice

Objective To observe the influence of expression of dexamethasone on thymus activation regulated chemokine(TARC) in asthma smooth muscle cells in asthmatic mice models.Methods Thirty-six mice were randomly divided into three groups: normal control group(group A),asthma model group(group B),and dexamethasone treated group(group C).The asthmatic mice models were established by OVA and AL(OH)3.White cells in BALF and eosinophils(EOS) were counted,HE-stained was used to observe the changes of pulmonary histopathology.The levels of TARC and IL-4 in both serum and BALF were measured by enzyme-linked immunosorbent assay(ELISA),then the expression of TARC protein in airway smooth muscle cells was assessed with immunohistochemistry.Results The total cell numbers and EOS count of group B were significantly higher than those in group A and group C(P<0.01),EOS counts of group C were higher than those of group A(P<0.05).The concentrations of TARC and IL-4 in serum of group B were obviously higher than that in group A and group C(P<0.01).The concentrations of TARC and IL-4 in BALF of group B were significantly higher than those in group A and group C(P<0.01);the concentrations of TARC in BALF of group C were higher than those in group A(P<0.01).The protein expressions of TARC in airway smooth muscle cells of group B were significantly higher than those in group A and group C(P<0.01).In mice serum,strong positive correlations were found between TARC and IL-4(r=0.669,P<0.01);there were significant positive correlations between TARC and IL-4 in BALF(r=0.845,P<0.01).Conclusions The expressions of TARC in asthma smooth musde cells of asthma mice were significantly higher than those in normal control group.Dexamethasone may inhibit TARC expression through reducing secretion of IL-4.