INTERMEDIATE-SIZED FILAMENTS OF THE PREKERATIN TYPE IN MYOEPITHELIAL CELLS
INTERMEDIATE-SIZED FILAMENTS OF THE PREKERATIN TYPE IN MYOEPITHELIAL CELLS
复制标题
DOI：
10.1083/jcb.84.3.633
复制
发表时间：
1980-01-01
影响因子：
7.8
通讯作者：
KEENAN, TW
中科院分区：
文献类型：
--
作者：
FRANKE, WW;SCHMID, E;KEENAN, TW
从乳腺肌上皮细胞，改性的汗腺的牛口和唾液腺已研究了EM和免疫荧光显微镜在冷冻切片，以进一步表征这些细胞中存在的中等大小的细丝的类型。电镜显示所有肌上皮细胞都含有大量的中等大小（7-11 nm）的细丝，其中许多被锚定在典型的桥粒或半桥粒上。中等大小的细丝也与大量的收缩元件密切相关，这些收缩元件被鉴定为典型的5-6 nm微丝束和特征性间隔的致密体。这种组织类似于描述的各种平滑肌细胞。在免疫荧光显微镜下，使用对各种类型的中等大小的细丝特异性的抗体，肌上皮细胞被前角蛋白的抗体强烈地装饰。它们不被波形蛋白的抗体特异性染色，波形蛋白染色间充质细胞，也不被鸡砂囊结蛋白的抗体特异性染色，鸡砂囊结蛋白装饰哺乳动物骨骼肌和心肌中平滑肌Z带和闰盘中的原纤维。肌上皮细胞也被肌动蛋白抗体强烈染色。上皮特征，如存在的前角蛋白类型的中等大小的细丝所示，在分化的收缩性肌上皮细胞中得以维持。结蛋白和含结蛋白的细丝通常与肌样细胞收缩的特化无关，但对肌源性分化具有特异性。在肌上皮细胞中，前角蛋白丝的排列和功能可能与平滑肌细胞中的结蛋白丝相似。
Myoepithelial cells from mammary glands, the modified sweat glands of bovine muzzle and salivary glands have been studied by EM and by immunofluorescence microscopy in frozen sections to further characterize the type of intermediate-sized filaments present in these cells. EM has shown that all myoepithelial cells contain extensive meshworks of intermediate-sized (7-11 nm) filaments, many of which are anchored at typical desmosomes or hemidesmosomes. The intermediate-sized filaments are also intimately associated with masses of contractile elements, identified as bundles of typical 5-6 nm microfilaments and with characteristically spaced dense bodies. This organization resembles that described for various smooth muscle cells. In immunofluorescence microscopy, using antibodies specific for the various classes of intermediate-sized filaments, the myoepithelial cells are strongly decorated by antibodies to prekeratin. They are not specifically stained by antibodies to vimentin, which stain mesenchymal cells, nor by antibodies to chick gizzard desmin, which decorate fibrils in smooth muscle Z bands and intercalated disks in skeletal and cardiac muscle of mammals. Myoepithelial cells are also strongly stained by antibodies to actin. The epithelial character, as indicated by the presence of intermediate-sized filaments of the prekeratin type, is maintained in the differentiated contractile myoepithelial cell. Desmin and desmin-containing filaments are not generally associated with muscle-like cell specialization for contraction but are specific to myogenic differentiation. In myoepithelial cells prekeratin filaments are arranged and might function in a manner similar to the desmin filaments in smooth muscle cells.