Watt F M
Keratinocyte Laboratory, Imperial Cancer Research Fund, London, UK.
J Cell Sci Suppl. 1987;8:313-26. doi: 10.1242/jcs.1987.supplement_8.17.
Human epidermal keratinocytes can be grown in culture under conditions in which they assemble a tissue with the same basic organization as normal epidermis. The cells stratify, mitosis is restricted to the basal layer and terminal differentiation occurs as the cells move through the suprabasal layers. Keratinocytes do not have to leave the basal layer in order to undergo terminal differentiation, but the two processes are normally linked, because during terminal differentiation the adhesive affinity of keratinocytes for the culture substratum and for other keratinocytes is reduced. Down-regulation of synthesis of basement membrane components and their receptors may provide the molecular basis for the reduction in cell-substratum adhesiveness. However, the molecules that mediate changes in cohesiveness have not yet been identified. Restriction of substratum contact, so that cells are prevented from spreading, appears to be one signal that induces keratinocytes to stop dividing and undergo terminal differentiation.
人表皮角质形成细胞可在培养条件下生长，在此条件下它们会组装出一个具有与正常表皮相同基本组织结构的组织。细胞分层，有丝分裂局限于基底层，并且随着细胞穿过基底上层会发生终末分化。角质形成细胞不必离开基底层就能进行终末分化，但这两个过程通常是相关联的，因为在终末分化过程中，角质形成细胞对培养底物和其他角质形成细胞的黏附亲和力会降低。基底膜成分及其受体合成的下调可能为细胞与底物黏附性降低提供分子基础。然而，介导黏附性变化的分子尚未被鉴定出来。限制底物接触，从而防止细胞铺展似乎是诱导角质形成细胞停止分裂并进行终末分化的一个信号。
