银屑病皮损内酪氨酸蛋白激酶活性的初步研究

Preliminary Study on Tyrosine Protein Kinase in Keratinocytes of Psoriatic Lesions

目的 探讨酪氨酸蛋白激酶 (TPK)在银屑病表皮异常增生中的作用。方法 通过外源性底物磷酸化的方法，测定银屑病进行期皮损角质形成细胞的 TPK活性。 结果 ① 银屑病进行期皮损角质形成细胞基础 TPK活性显著增高，且对于转化生长因子－α的刺激，反应性明显增强；② 增高的基础 TPK活性与角质形成细胞膜表皮生长因子受体的表达量呈明显正相关；同时银屑病角质形成细胞表皮生长因子受体的自磷酸化水平亦显著增高。结论 TPK活性增高，以及对有丝分裂信号刺激的反应增强，可能在表皮的增生中起到重要作用， TPK活性的改变可能主要是由于表皮生长因子受体的表达异常所致，表皮生长因子受体可能在银屑病表皮的异常增生中发挥着重要作用。

Objective To study the mechanism of abnormal proliferation of keratinocytes in psoriasis． Methods The activity of tyrosine protein kinase (TPK) in the keratinocytes of lesional skin in progressive stage was assayed by phosphorylation of exogenous substrates． Results The basic activity of TPK and autophosphorylation of transforming growth factor(TGF) receptor were significantly increased in the psoriatic lesions in progressive stage.The TPK activity of epidermal growth factor(EGF)- receptor was also significantly increased in the psoriatic lesions after stimulation of TGF- alpha as compared with normal control.There was a positive correlation between the activity of TPK and expression of EGFR in the psoriatic keratinocytes． Conclusions The increased activity of TPK and the high reactivity to the stimulation of growth factors are important in the hyperproliferation of psoriatic keratinocytes.The change of the activity of TPK may result from increased expression of EGF receptors. EGF receptors probably play an important role in keratinocyte hyperproliferation of psoriasis. Key words Psoriasis Protein- Tyrosine kinase Receptors, epidermal growth factor- urogas- trone Transforming growth factor alpha