Beaulieu J F, Vachon P H
Département d'Anatomie et de Biologie Cellulaire, Faculté de Médecine, Université de Sherbrooke, Québec, Canada.
Gastroenterology. 1994 Apr;106(4):829-39. doi: 10.1016/0016-5085(94)90740-4.
BACKGROUND/AIMS: Intestinal epithelial cell proliferation, migration, and differentiation are susceptible to various influences along the crypt-villus axis including compositional changes in the basement membrane and differential expression of receptors for these components. However, laminin has been consistently detected at the epithelial basement membrane without significant variation in relation to the crypt-villus functional unit. The aim of this study was to examine the distribution of individual laminin chains.
The patterns of distribution of laminin A, M (an A-chain variant), B1, and B2 chains as well as the integrins alpha 6 beta 1 and alpha 6 beta 4, two laminin receptors, were determined by indirect immunofluorescence in the adult human small intestine.
Markedly distinct patterns of laminin chain expression were observed along the crypt-villus axis. The A chain was found predominantly associated with the differentiated epithelial cells on the villus whereas the M chain was restricted to the basement membrane of crypts. However, both B1 and B2 chains were detected all along the intestinal basement membrane. Furthermore, alpha 6 beta 1 and alpha 6 beta 4 integrins were found to be expressed by all enterocytes.
These observations show a reciprocal expression of laminin isoforms along the crypt-villus axis and support the concept that the intestinal epithelial basement membrane is subjected to intricate compositional changes.
背景/目的：肠道上皮细胞的增殖、迁移和分化易受沿隐窝-绒毛轴的各种影响，包括基底膜成分变化以及这些成分受体的差异表达。然而，层粘连蛋白始终在上皮基底膜中被检测到，与隐窝-绒毛功能单位无关的显著变化。本研究的目的是检查各个层粘连蛋白链的分布。
通过间接免疫荧光法在成人小肠中确定层粘连蛋白A、M（A链变体）、B1和B2链以及两种层粘连蛋白受体整合素α6β1和α6β4的分布模式。
沿隐窝-绒毛轴观察到层粘连蛋白链表达的明显不同模式。发现A链主要与绒毛上分化的上皮细胞相关，而M链局限于隐窝的基底膜。然而，B1和B2链在整个肠道基底膜中均被检测到。此外，发现所有肠细胞均表达α6β1和α6β4整合素。
这些观察结果表明层粘连蛋白异构体沿隐窝-绒毛轴相互表达，并支持肠道上皮基底膜经历复杂成分变化的概念。
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