Pruniéras M, Régnier M, Fougère S, Woodley D
J Invest Dermatol. 1983 Jul;81(1 Suppl):74s-81s. doi: 10.1111/1523-1747.ep12540736.
On histologic vertical sections of skin, the epidermis is separated from the dermis by an amorphous thin membrane, the basal lamina. Ultrastructurally, the basal lamina is composed of four areas, including the basal-cell plasma membrane and hemidesmosomes, the lamina lucida, the lamina densa, and the sub-lamina densa fibrillar region. In culture, epidermal keratinocytes are able to produce hemidesmosomes, lamina lucida, and lamina densa. There is no evidence that cultured keratinocytes can produce sub-lamina densa fibrils. Biochemically, the lamina lucida contains two major glycoproteins. One, the bullous pemphigoid antigen, is synthesized by epidermal keratinocytes in vitro. These cells also synthesize laminin, the other glycoprotein of lamina lucida. At the interface between lamina lucida and lamina densa there is probably a heparan sulfate proteoglycan. Whether this proteoglycan is produced by keratinocytes in culture is not known, but the possibility can be considered. Lamina densa contains collagen IV, and this collagen is synthesized by keratinocytes in culture. However, cultured keratinocytes may also synthesize collagen types I, III, and V. Type V is associated with the basal lamina, but its exact location is unknown. Types I and III (if they are produced in vivo) would be situated in the sub-basal lamina region. The problem of fibronectin remains unsolved. There is "some" fibronectin in the lamina lucida, but its origin is not clear.
在皮肤的组织学垂直切片上，表皮通过一层无定形的薄膜——基底层与真皮分离。在超微结构上，基底层由四个区域组成，包括基底细胞的质膜和半桥粒、透明层、致密层以及致密层下纤维状区域。在培养过程中，表皮角质形成细胞能够产生半桥粒、透明层和致密层。没有证据表明培养的角质形成细胞能产生致密层下纤维。从生化角度来看，透明层含有两种主要糖蛋白。一种是大疱性类天疱疮抗原，可由表皮角质形成细胞在体外合成。这些细胞还能合成层粘连蛋白，即透明层的另一种糖蛋白。在透明层和致密层的界面处可能存在一种硫酸乙酰肝素蛋白聚糖。这种蛋白聚糖是否由培养的角质形成细胞产生尚不清楚，但可以考虑这种可能性。致密层含有IV型胶原蛋白，这种胶原蛋白可由培养的角质形成细胞合成。然而，培养的角质形成细胞也可能合成I型、III型和V型胶原蛋白。V型与基底层相关，但其确切位置尚不清楚。I型和III型（如果它们在体内产生）将位于基底层下区域。纤连蛋白的问题仍未解决。透明层中有“一些”纤连蛋白，但其来源尚不清楚。
