Verrando P, Lissitzky J C, Sarret Y, Winberg J O, Gedde-Dahl T, Schmitt D, Bruckner-Tuderman L
Institut de Biologie et Chimie des Protéines CNRS U 412, Lyon, France.
Lab Invest. 1994 Oct;71(4):567-74.
Junctional epidermolysis bullosa (JEB) encompasses several genodermatoses characterized by skin blistering, and possibly disturbed wound healing. Although the molecular defects underlying JEB are not known, we have demonstrated previously that nicein, an adhesive laminin-related basement membrane component, is immunologically altered in the very severe JEB of Herlitz type (H-JEB), and was expressed to a lesser extent in skin from patients with inversa JEB (I-JEB). In this study, we assessed adhesion and migration of H-JEB and I-JEB keratinocytes on exogenous nicein and laminin to get insights on the biologic function defective in JEB skin.
Adhesion of cultured epidermal keratinocytes from H-JEB and I-JEB patients was assayed by quantitation of cell attachment 1 hour after seeding into microtiter wells coated with nicein or laminin. Cell migration and modulation by function-blocking antibodies to integrins was quantified by computer-assisted image analysis of the tracks left by the cells in a phagokinetic assay using gold particles coated with nicein or laminin.
In spite of the fact that H-JEB keratinocytes do not produce normal immunoreactive nicein, they were able to adhere on exogenous nicein similarly to normal and I-JEB keratinocytes which produce nicein. Adhesion of both JEB and normal keratinocytes to laminin was weak compared with nicein. At low and high concentrations of nicein, a reduced migration response occurred with H-JEB keratinocytes whereas I-JEB cells behaved like their normal counterparts. Integrin alpha 3 beta 1 was dominantly involved in adhesion and migration of all these cells. Laminin did not support the migration of either JEB or normal keratinocytes.
H-JEB and I-JEB keratinocytes which produce no or less nicein than normal keratinocytes are able to adhere and migrate on exogenous nicein. Integrin alpha 3 beta 1 which is specifically involved in migration and adhesion of keratinocytes on nicein does not appear altered in JEB. These data indicate that defective nicein rather than modifications of the nicein-recognizing receptor play a central role in the pathogenesis of H-JEB.
交界性大疱性表皮松解症（JEB）包含几种以皮肤水疱形成以及可能的伤口愈合紊乱为特征的遗传性皮肤病。尽管JEB潜在的分子缺陷尚不清楚，但我们先前已证明，一种黏附性层粘连蛋白相关的基底膜成分——尼斯因，在赫利茨型（H-JEB）的极重度JEB中发生免疫改变，且在反向性JEB（I-JEB）患者的皮肤中表达程度较低。在本研究中，我们评估了H-JEB和I-JEB角质形成细胞在外源性尼斯因和层粘连蛋白上的黏附及迁移情况，以深入了解JEB皮肤中存在缺陷的生物学功能。
通过对接种到包被有尼斯因或层粘连蛋白的微量滴定孔中1小时后的细胞附着情况进行定量，来检测H-JEB和I-JEB患者培养的表皮角质形成细胞的黏附。在使用包被有尼斯因或层粘连蛋白的金颗粒进行的吞噬动力学试验中，通过计算机辅助图像分析细胞留下的轨迹，来定量细胞迁移以及整合素功能阻断抗体的调节作用。
尽管H-JEB角质形成细胞不产生正常的免疫反应性尼斯因，但它们能够像产生尼斯因的正常角质形成细胞和I-JEB角质形成细胞一样，在外源性尼斯因上黏附。与尼斯因相比，JEB和正常角质形成细胞对层粘连蛋白的黏附都较弱。在低浓度和高浓度尼斯因条件下，H-JEB角质形成细胞的迁移反应降低，而I-JEB细胞的表现与正常细胞相似。整合素α3β1主要参与所有这些细胞的黏附和迁移。层粘连蛋白不支持JEB或正常角质形成细胞的迁移。
与正常角质形成细胞相比，不产生或产生较少尼斯因的H-JEB和I-JEB角质形成细胞能够在外源性尼斯因上黏附和迁移。在JEB中，特异性参与角质形成细胞在尼斯因上迁移和黏附的整合素α3β1似乎未发生改变。这些数据表明，有缺陷的尼斯因而非识别尼斯因的受体的改变，在H-JEB的发病机制中起核心作用。
