Joubeh Sohaila, Mori Osamu, Owaribe Katsushi, Hashimoto Takashi
Department of Dermatology, Kurume University School of Medicine, Kurume, Japan.
Exp Dermatol. 2003 Aug;12(4):365-70. doi: 10.1034/j.1600-0625.2002.120402.x.
The ultrastructure and constituent components of the basement membrane zone (BMZ) of the interfollicular epidermis have been well characterized. However, little is known about the junctions between dermal papilla and the surrounding epithelial cells of the hair bulb, as well as those junctions between connective tissues and epithelial cells outside the hair follicle. In the present study, immunofluorescence was used to determine the expression of various BMZ components, particularly plectin, BP230, BP180, alpha6beta4 integrin, laminin 5 and type VII collagen, in anagen hair follicles from human scalp. All the BMZ components examined showed essentially the same immunofluorescence staining pattern. Specifically, staining of the upper portion of the hair follicle demonstrated expression of all BMZ components with a labeling intensity similar to that found in the interfollicular epidermis. Staining in the lower portion of the hair follicle, however, was markedly different: all the BMZ components showed a gradual decrease in staining intensity. Particularly, outside the hair bulb, the linear staining was diminished and even discontinuous in some areas. Finally, between dermal papilla and epithelial cells inside the hair bulb, there was a strong immunoreactivity for all the BMZ components except for BP230, which was completely negative. The present study also confirmed a previous reported ultrastructural finding that hemidesmosomes are not apparent in the hair bulb's exterior BMZ nor in the dermal papilla junctions. Instead, peculiar cloudy materials were seen in both the lamina densa and the adjacent epithelium outside the hair bulb. Taken together, the diminished expression of all the BMZ components outside the hair bulb, as well as the complete absence of BP230 at the dermal papilla junction, seem to be responsible for the incomplete ultrastructure of hemidesmosomes in these regions. Furthermore, the results in the present study led us to speculate that the expression of BMZ components inside and outside the hair bulb are markedly decreased in the transient regions of the hair follicle as compared with their expression in the permanent region, signified by the upper portion of the hair follicle. When the hair follicle moves upward in catagen or downward in anagen, the complete structure of the hemidesmosome may stabilize the upper portion to the surrounding connective tissues, while the incomplete hemidesmosome may facilitate the movement of the transient region.
毛囊间表皮基底膜带（BMZ）的超微结构和组成成分已得到充分表征。然而，关于毛乳头与毛囊球周围上皮细胞之间的连接，以及毛囊外结缔组织与上皮细胞之间的连接，我们却知之甚少。在本研究中，我们利用免疫荧光法来测定人头皮生长期毛囊中各种BMZ成分的表达，特别是网蛋白、BP230、BP180、α6β4整合素、层粘连蛋白5和VII型胶原蛋白。所有检测的BMZ成分均呈现出基本相同的免疫荧光染色模式。具体而言，毛囊上部的染色显示所有BMZ成分均有表达，其标记强度与毛囊间表皮中的相似。然而，毛囊下部的染色则明显不同：所有BMZ成分显示染色强度逐渐降低。特别是在毛囊球外区域，线性染色减弱，在某些区域甚至不连续。最后，在毛囊球内的毛乳头与上皮细胞之间，除BP230完全阴性外，所有BMZ成分均有强烈的免疫反应性。本研究还证实了先前报道的超微结构发现，即在毛囊球外部的BMZ以及毛乳头连接处，半桥粒并不明显。相反，在毛囊球外的致密板层和相邻上皮中均可见特殊的云雾状物质。综上所述，毛囊球外所有BMZ成分表达的减少，以及毛乳头连接处BP230的完全缺失，似乎是这些区域半桥粒超微结构不完整的原因。此外，本研究结果使我们推测，与以毛囊上部为代表的永久区域相比，毛囊球内外BMZ成分在毛囊的过渡区域的表达明显降低。当毛囊在退行期向上移动或在生长期向下移动时，完整结构的半桥粒可使上部与周围结缔组织稳定连接，而不完整的半桥粒则可能促进过渡区域的移动。
