Akt/PKB对哮喘小鼠Fas表达的调节作用

目的探讨在哮喘发病中,Akt/PKB(protein kinase B)对哮喘小鼠C7-T5节段脊神经及相应节段脊髓后角内Fas表达的调节作用。方法BALB/c小鼠30只,按随机数字表法均分为正常对照组、哮喘组、Akt/PKB阻断组,利用肺功能仪测小鼠气道阻力、免疫荧光方法检测各组小鼠C7-T5节段脊神经及相应节段脊髓后角内Fas的表达、Western blot检测各组小鼠C7-T5节段脊神经内Fas的表达。结果哮喘组小鼠吸气阻力和呼气阻力明显高于正常组(P<0.01);免疫荧光结果显示哮喘组C7-T5节段脊神经及相应节段脊髓后角内Fas阳性产物的平均光密度值(mean optical density,MOD)高于正常对照组(P<0.01);而Akt/PKB阻断组与哮喘组相比,上述部位Fas阳性反应产物的MOD值明显升高(P<0.01)。Western blot结果显示:与正常对照组比较,哮喘组小鼠C7-T5节段脊神经内Fas的相对灰度值(integrated density value,IDV)与内参照IDV的比值明显降低(P<0.05),而Akt/PKB阻断组Fas目标带的IDV与内参照IDV的比值则明显高于哮喘组(P<0.05)。结论在NGF介导的哮喘发病机制中,Akt/PKB能下调哮喘小鼠C7-T5节段脊神经及相应节段脊髓后角内Fas的表达。

The upregulative effect of Akt/PKB on Fas in the spinal ganglia and spinal dorsal horn of the asthmatic mice

Aim To study the regulatory effect of Akt/PKB on the expression of Fas in the spinal ganglia and the corresponding spinal dorsal horn of the asthmatic mice.Methods 30 BALB/c mice were evenly divided into normal control group,asthmatic group,Akt/PKB blocked with LY-294002 group.The airway resistance of mice was measured with pulmonary function meter;The expression of Fas was observed by immunofluorescence in the C7-T5 spinal ganglia and the corresponding spinal dorsal horn of all the groups.The change of Fas was investigated by means of Western blot in the C7-T5 spinal cord.Results Inspiratory resistance and expiratory resistance in the asthmatic mice are higher than those in normal control mice,but obviously lower in the Akt/PKB blocked with LY-294002 group than in the asthmatic mice.Immunofluorescence showed that the mean optic density(MOD) of Fas positive product in the spinal ganglia and the corresponding spinal dorsal horn decreased more significantly in the asthmatic mice than in normal control(P < 0.01) ;but increased more markedly in the Akt/PKB blocked with LY-294002 group than in the asthmatic mice(P < 0.01).Western blot results showed that the ratios between integrated density value(IDV) for Fas protein band and IDV for β-actin protein band in the C7-T5 spinal cord decreased more significantly in the asthmatic mice than in normal control(P < 0.05) ;but increased more in the asthmatic mice blocked with LY-294002 than in the asthmatic mice(P < 0.05).Conclusion one of the mechanisms for Akt/PKB to involue in the pathogenesis of asthma induced by NGF might be by upregulating the expression of Fas in the spinal ganglia and spinal dorsal horn of the asthmatic mice.