Review Article

RGD-Dependent Epithelial Cell-Matrix Interactions in the Human Intestinal Crypt

Figure 2

Distribution of laminins and laminin receptors of the integrin family as well as the RGD components fibronectin and the α5β1 integrin receptor along the crypt-villus axis in the human small intestine. (a) Organization of the crypt-villus epithelial renewing unit. Villi are lined by functional epithelial cells responsible for digestion and absorption of nutrients. Stem cells located at the bottom of the gland generate transit amplifying cells that expand in the middle of the gland until they reach the upper gland region where they stop proliferating and undertake their terminal differentiation program before reaching the base of the villus. (b) Patterns of distribution of laminins at the epithelial BM as well as laminin receptors of the integrin family revealed differential expression of these molecules along the crypt-villus axis according to the cell state as shown by dark areas. (c) The RGD components fibronectin and its specific integrin receptor α5β1 were found mostly confined to the crypt region (dark areas).
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