Ryynänen J, Tan E M, Hoffren J, Woodley D T, Sollberg S
Department of Dermatology, Thomas Jefferson University, Philadelphia, Pennsylvania.
Lab Invest. 1993 Sep;69(3):300-4.
Type VII collagen is a minor collagen found in anchoring fibrils. It is expressed predominantly by keratinocytes. In this study, we report the localization and spatial distribution of type VII collagen gene expression in the human umbilical cord, a fetal-derived tissue.
Human umbilical cords were examined in indirect immunofluorescence studies, employing a mouse monoclonal anti-human type VII collagen antibody. Endothelial cells were cultured from the vein and grown on chamber slides for the detection of type VII collagen epitopes. In addition, cultured human umbilical vein cells were analyzed by Northern transfer analysis and by polymerase chain reaction for the expression of the corresponding gene. Fibroblast-like cells were isolated from the Wharton's jelly and were analyzed similarly for type VII collagen expression as well.
We demonstrate that type VII collagen is expressed by human umbilical tissue and cells. Indirect immunofluorescence studies demonstrate the presence of type VII collagen epitopes in the epithelium surrounding a connective tissue region known as Wharton's jelly. In addition, there was low but detectable immunofluorescence signal associated with endothelial cells of blood vessels within the umbilical cord. In vitro, the fibroblast-like cells cultured from the Wharton's jelly showed prominent type VII collagen signal. This result was supported by the finding of high level of type VII collagen mRNA in these cells. The human endothelial cells from the vein demonstrated weak but detectable staining for type VII collagen, and the corresponding gene expression was shown by polymerase chain reaction analysis of the mRNA of the endothelial cells.
The results show that umbilical tissue and cells, specifically those from the Wharton's jelly, are relatively enriched in type VII collagen. There is differential spatial localization of this collagen in the fetal tissue. The novel finding is that cells, other than epithelial cells such as keratinocytes, are able to express the type VII collagen gene.
VII型胶原蛋白是一种存在于锚定原纤维中的次要胶原蛋白。它主要由角质形成细胞表达。在本研究中，我们报告了VII型胶原蛋白基因在人脐带（一种胎儿来源的组织）中的定位和空间分布。
使用小鼠单克隆抗人VII型胶原蛋白抗体，通过间接免疫荧光研究检测人脐带。从静脉中培养内皮细胞，并在培养皿玻片上生长以检测VII型胶原蛋白表位。此外，通过Northern印迹分析和聚合酶链反应分析培养的人脐静脉细胞中相应基因的表达。从华通胶中分离出成纤维样细胞，并同样分析其VII型胶原蛋白的表达。
我们证明VII型胶原蛋白在人脐带组织和细胞中表达。间接免疫荧光研究表明，在称为华通胶的结缔组织区域周围的上皮中存在VII型胶原蛋白表位。此外，脐带内血管内皮细胞存在低但可检测到的免疫荧光信号。在体外，从华通胶中培养的成纤维样细胞显示出明显的VII型胶原蛋白信号。这些细胞中高水平的VII型胶原蛋白mRNA的发现支持了这一结果。静脉来源的人内皮细胞对VII型胶原蛋白显示出微弱但可检测到的染色，并且通过对内皮细胞mRNA的聚合酶链反应分析显示了相应的基因表达。
结果表明脐带组织和细胞，特别是来自华通胶的组织和细胞，VII型胶原蛋白相对富集。这种胶原蛋白在胎儿组织中有不同的空间定位。新发现是除了角质形成细胞等上皮细胞外，其他细胞也能够表达VII型胶原蛋白基因。
