Schaefer B M, Koch J, Wirzbach A, Kramer M D
Institute for Immunology, Im Neuenheimer Feld 305, Heidelberg, D-69120, Germany.
Exp Cell Res. 2001 Jun 10;266(2):250-9. doi: 10.1006/excr.2001.5215.
To analyze the inhibitor of DNA-binding type 1 (ID1) in the human epidermis and in cultured keratinocytes we generated and characterized ID1-specific monoclonal antibodies. Immunohistological studies on human skin biopsies revealed that ID1 is not detectable in normal human epidermis but in lesional epidermis of bullous pemphigoid. In the latter case we found ID1 in the cytoplasm of basal and proximal suprabasal keratinocytes. Cultured normal human epidermal keratinocytes displayed ID1 in the cytoplasm; upon differentiation into a multilayered keratinocyte sheet, ID1 was no longer detectable. It was reexpressed after dispase-mediated detachment of the keratinocyte cultures from the growth substratum. In this case ID1 was localized to the cytoplasm and the nucleus. Our data indicate that after epidermal injury-in our case loss of cell-matrix contact-ID1 is upregulated in affected keratinocytes. In view of the ID1 function in other cell types, we speculate that ID1 facilitates the transition from the resting to the migrating and proliferating keratinocyte required for efficient repair of epidermal lesions by reepithelialization. Taken together we suggest that ID1 is an important player in epidermal (patho-)physiology.
为了分析人类表皮和培养的角质形成细胞中DNA结合蛋白1型（ID1），我们制备并鉴定了ID1特异性单克隆抗体。对人皮肤活检组织进行的免疫组织学研究表明，在正常人类表皮中检测不到ID1，但在大疱性类天疱疮的皮损表皮中可以检测到。在后一种情况下，我们在基底角质形成细胞和基底上层近端角质形成细胞的细胞质中发现了ID1。培养的正常人类表皮角质形成细胞在细胞质中显示有ID1；在分化为多层角质形成细胞片后，ID1不再能被检测到。在通过dispase介导将角质形成细胞培养物从生长基质上分离后，ID1重新表达。在这种情况下，ID1定位于细胞质和细胞核。我们的数据表明，在表皮损伤后——在我们的研究中是细胞与基质接触丧失后——受影响的角质形成细胞中ID1上调。鉴于ID1在其他细胞类型中的功能，我们推测ID1通过再上皮化促进角质形成细胞从静止状态向迁移和增殖状态转变，这是表皮损伤有效修复所必需的。综上所述，我们认为ID1是表皮（病理）生理学中的一个重要因素。
