Bickenbach J R, Holbrook K A
Am J Anat. 1986 Sep;177(1):97-106. doi: 10.1002/aja.1001770111.
The morphology of human embryonic and fetal skin growth in organ culture at the air-medium interface was examined, and the labeling indices of the epidermal cells in such cultures were determined. The two-layered epidermis of embryonic specimens increased to five or six cell layers after 21 days in culture, and the periderm in such cultures changed from a flat cell type to one with many blebs. The organelles in the epidermal cells remained unchanged. Fetal epidermis, however, differentiated when grown in this organ culture system from three layers (basal, intermediate, and periderm) to an adult-type epidermis with basal, spinous, granular, and cornified cell layers. Keratohyalin granules, lamellar granules, and bundles of keratin filaments, organelles associated with epidermal cell differentiation, were observed in the suprabasal cells of such cultures. The periderm in these fetal cultures formed blebs early but was sloughed with the stratum corneum in older cultures. The rate of differentiation of the fetal epidermis in organ culture was related to the initial age of the specimen cultured, with the older specimens differentiating at a faster rate than the younger specimens. Labeling indices (LIs) of embryonic and fetal epidermis and periderm were determined. The LI for embryonic basal cells was 8.5% and for periderm was 8%. The fetal LIs were 7% for basal cells, 1% for intermediate cells, and 3% for periderm. The ability to maintain viable pieces of skin in organ culture affords a model for studying normal and abnormal human epidermal differentiation from fetal biopsies and for investigating proliferative diseases.
研究了人胚胎和胎儿皮肤在气-培养基界面器官培养中的生长形态，并测定了此类培养物中表皮细胞的标记指数。胚胎标本的两层表皮在培养21天后增加到五或六层，此类培养物中的周皮从扁平细胞类型变为有许多泡的细胞类型。表皮细胞中的细胞器保持不变。然而，胎儿表皮在这种器官培养系统中生长时，从三层（基底、中间和周皮）分化为具有基底、棘状、颗粒状和角质化细胞层的成人型表皮。在这些培养物的基底上层细胞中观察到了与表皮细胞分化相关的细胞器，如透明角质颗粒、板层颗粒和角蛋白丝束。这些胎儿培养物中的周皮早期形成泡，但在较老的培养物中与角质层一起脱落。胎儿表皮在器官培养中的分化速度与培养标本的初始年龄有关，年龄较大的标本比年龄较小的标本分化速度更快。测定了胚胎和胎儿表皮及周皮的标记指数（LIs）。胚胎基底细胞的LI为8.5%，周皮为8%。胎儿的LI，基底细胞为7%，中间细胞为1%，周皮为3%。在器官培养中维持皮肤活组织块的能力为研究胎儿活检的正常和异常人类表皮分化以及研究增殖性疾病提供了一个模型。
