银屑病患者指甲、鳞屑SDS-电泳图谱和转谷氨酰胺酶活性的探讨

Discussion on the SDS-PAGE map and TGase 1 activity in trimmed nails and epidermal scales of the patients with psoriasis

目的探讨银屑病患者指甲、鳞屑SDS-电泳图谱和转谷氨酰胺酶活性(Transglutaminase 1,TGase 1)。方法取5例银屑病患者的指甲、鳞屑与5例健康者指甲、鳞屑,分别提取蛋白质进行SDS-PAGE(聚苯乙烯胺凝胶电泳)。应用HRP-单丹酰尸胺结合物对鳞屑铺片标本检测TGase 1酶活性。结果健康者指甲和鳞屑的SDS-电泳图谱皆呈现4条主带:63kDa,54kDa,48kDa及38kDa,银屑病患者指甲及鳞屑的SDS-电泳图谱也呈现以上4条主带,但多数主带扫描数值水平较高,P<0.05。健康者的鳞屑铺片标本TGase 1酶活性呈现棕黄色细颗粒,定位于角质深层角质形成细胞(keratinocyte,KC)的周缘,相比之下银屑病患者的TGase 1酶活性缺乏。结论指甲及鳞屑的SDS-PAGE电泳主带相似,前者图谱更清晰,可能与其蛋白较稳定有关;银屑病患者比健康者的SDS-电泳图谱主带表达水平高,提示其KC可能呈增生状态,表达产物较多;患者TGase 1酶活性的缺如提示其表皮屏障功能有缺陷,可能与其参与代偿性增生有关。

Objective To examine the SDS-PAGE map and TGase 1 activity in the trimmed nails and epidermal scales of the psoriasis patients. Methods The trimmed nails and epidermal scales were collected respectively from 5 cases of psoriasis patients and 5 healthy volunteers. The SDS-PAGE was performed by the extracted protein from both nails and scales. The TGase 1 activity was detected in the spread scale specimen by using HRP-dansylcadaverine conjugate. Results There were 4 major bands, including 63 kDa, 54 kDa, 48 kDa and 38 kDa found in the nail or scale SDS-PAGE map from both psoriasis and healthy cases. In comparison of the psoriasis SDS-PAGE map with the healthy cases, the scanning value in most of the 4 major bands was high, P〈0.05. In the healthy specimen the TGase 1 activity appeared brownish-yellow colored granules localized in the border of the deeper keratinocytes; while the TGase 1 activity was paucity in the psoriasis cases. Conclusion The results of the nail SDS PAGE and the scale SDS-PAGE were similar in spite of the former with more distinct map, which may be associated with more stability of the protein contained in the nail. The expression level of the major bands in the psoriasis SDS-PAGE was higher than that in the healthy, suggesting the proliferatiing keratinocytes rich in cell products in the psoriasis cases. The TGase 1 activity in paucity suggests that the psoriasis cases may have defective epidermal barrier function.