Extracellular matrix gradients in the space of disse: Relevance to liver biology
✍ Scribed by Lola M. Reid; Anthony S. Fiorino; Samuel H. Sigal; Shlomo Brill; Patricia A. Holst
- Publisher
- John Wiley and Sons
- Year
- 1992
- Tongue
- English
- Weight
- 697 KB
- Volume
- 15
- Category
- Article
- ISSN
- 0270-9139
No coin nor oath required. For personal study only.
✦ Synopsis
The extracellular matrix, an insoluble complex of collagens (fibrillar and network), adhesion proteins (e.g., laminin, fibronectin) and proteoglycans (PGs) (e.g., heparan sulfate PGs, chondroitin sulfate PGs), is associated with all cells and is important in all aspects of adhesion, growth regulation and regulation of tissuespecific gene expression (1). The relevance of matrix to liver biology has been demonstrated in many articles in which investigators have analyzed purified matrix components or tissue extracts enriched in extracellular matrix (1-12). The study by McGuire et al. (13) has provided corroborating evidence to earlier studies (7) revealing that the extracellular matrix is functionally tissue specific. The authors have analyzed the impact of matrix on sinusoidal endothelial cells. A unique feature of the hepatic endothelial cells is their fenestrations which permit plasma components more direct access to the parenchyma. The authors have demonstrated that the fenestral size, number and morphology are regulated by extracellular matrix. They have come to these conclusions by analyzing rat sinusoidal endothelial cells freshly isolated by centrifugal elutriation and then cultured on substrata of purified matrix components, fibronectin or collagens or on tissue extracts enriched in extracellular matrix, Matrigel (available commercially from Collaborative Research, Bedford, MA) or a matrix extract from amnions.
Numerous reports, especially the pioneering studies of Dr. Joseph Madri and associates (14-16), indicate that extracellular matrix regulates many aspects of endothelial cell biology. However, sinusoidal endothelia have long been thought relatively independent of matrix because basement membranes cannot be readily demonstrated in the space of Disse. Indeed, the liver is referred to as an "epithelioid" tissue because its plates of parenchymal cells are not associated with a classic basement membrane, a defining feature of epithelia.