Murray K, de Lera J M, Astudillo A, McNicol A M
University Department of Pathology, Glasgow Royal Infirmary University NHS Trust, UK.
Virchows Arch. 1997 Nov;431(5):329-35. doi: 10.1007/s004280050107.
Cell-matrix interactions undoubtedly have a role in the development and maintenance of the complex nonrandom structure of the human pituitary gland. We have extended previous studies by documenting the patterns of immunoreactivity for type IV collagen, laminin and fibronectin in the fetal gland, comparing these with the adult patterns. In both we have examined the differences between the anterior lobe and intermediate zone in an attempt to elucidate the apparent differences in functional response between corticotrophs in the two areas. We have also examined expression of these proteins in a series of pituitary adenomas. Finally, we have immunolocalised beta 4 integrin, a component of the alpha 6 beta 4 laminin receptor, in the adult gland and in adenomas. In the anterior lobe of the adult gland, type IV collagen and laminin were present in both epithelial and vascular basement membrane. Fibronectin was related to the basement membrane but showed a less continuous distribution. beta 4 Integrin was expressed on the basal aspects of pituitary cells, in association with laminin, suggesting that this did identify the alpha 6 beta 4 laminin receptor. In addition, immunoreactivity was present on the lateral margins of some pituitary cells, which might indicate a role in cell-cell adhesion. None of the proteins showed specific association with any particular cell type, suggesting that these specific interactions do not regulate differentiation. This pattern of expression had developed in the fetal gland by the second trimester, with expression relating to vessels preceding that in epithelial basement membrane. Type IV collagen, laminin and fibronectin were also expressed in epithelial and vascular basement membrane in the intermediate zone of the adult gland, and around Rathke's cleft in the fetal gland. However, the organisation differed, with larger groups of cells enclosed within a single basement membrane. Possible vascular connections demonstrated between the posterior lobe and the intermediate zone would permit access of posterior lobe hormones to this zone. Our data confirmed disruption of expression in pituitary adenomas, type IV collagen, laminin and beta 4 integrin having a mainly perivascular distribution, with more variable immunoreactivity for fibronectin.
细胞与基质的相互作用无疑在人类垂体复杂的非随机结构的发育和维持中发挥作用。我们通过记录胎儿垂体中IV型胶原、层粘连蛋白和纤连蛋白的免疫反应模式，并将这些模式与成人模式进行比较，扩展了先前的研究。在这两项研究中，我们都检查了前叶和中间带之间的差异，试图阐明这两个区域促肾上腺皮质激素细胞在功能反应上的明显差异。我们还研究了这些蛋白质在一系列垂体腺瘤中的表达。最后，我们在成人垂体和腺瘤中对α6β4层粘连蛋白受体的一个组成部分β4整合素进行了免疫定位。在成人垂体前叶中，IV型胶原和层粘连蛋白存在于上皮和血管基底膜中。纤连蛋白与基底膜相关，但分布不太连续。β4整合素在垂体细胞的基底方面表达，与层粘连蛋白相关，表明这确实识别了α6β4层粘连蛋白受体。此外，一些垂体细胞的侧缘存在免疫反应性，这可能表明其在细胞间黏附中起作用。这些蛋白质均未显示与任何特定细胞类型有特异性关联，这表明这些特异性相互作用并不调节分化。这种表达模式在妊娠中期的胎儿垂体中就已形成，血管相关的表达先于上皮基底膜中的表达。IV型胶原、层粘连蛋白和纤连蛋白在成人垂体中间带的上皮和血管基底膜以及胎儿垂体的拉克氏裂周围也有表达。然而，组织结构有所不同，有更大的细胞群被包裹在单个基底膜内。后叶与中间带之间可能存在的血管连接将使后叶激素能够进入该区域。我们的数据证实了垂体腺瘤中表达的破坏，IV型胶原、层粘连蛋白和β4整合素主要呈血管周围分布，纤连蛋白的免疫反应性则更具变化。
