Collagen rich extracellular matrix

Fibroblasts Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules, [nih]... 

The odontoblasts secrete an extracellular matrix that is rich in collagen I and which also contains all of the other major bone proteins as well as a dentin sialoprotein and poorly characterized phosphate carriers, the phosphophoryns. 

Decorin is a small, leucine-rich proteoglycan and one of the many extracellular matrix (ECM) compounds. It interacts closely with the D and E bands of type 1 collagen and increases collagen s tensile strength.39,40 In rats with subcutaneously implanted devices, we found that the decorin was highly expressed at the middle and later stages of the foreign body reaction.17... 

The skin is an excellent barrier to microbial and parasitic infections. The most superficial layer of the skin is composed of flattened squamous cells, which are highly keratinized. Beneath this is the epidermal layer composed of cells tightly interconnected by desmosomes and other intercellular structures. These, in turn, are attached to the basement membrane composed of covalently bound or interwoven macromolecules. Between the basement membrane and a target blood vessel is an extracellular matrix rich in type I collagen, elastin and proteoglycan. Elastin and type I collagen are both interwoven fibrillar molecules, whereas the carbohydrate-rich proteoglycan behaves like a hydrated gel. For details of these macromolecular interactions, the reader is referred to reviews on the structure of skin. 

The normal artery is composed of three distinct layers (Fig. 34.21). That which is closest to the lumen of the vessel, the intima, is lined by a monolayer of endothelial cells that are bathed by the circulating blood. Just beneath these specialized cells lies the subintimal extracellular matrix, in which some vascular smooth muscle cells are embedded (the subintimal space). The middle layer, known as the tunica media, is separated from the intima by the internal elastic lamina. The tunica media contains lamellae of smooth muscle cells surrounded by an elastin- and collagen-rich matrix. The external elastic lamina forms the border between the tunica media and the outermost layer, the adventitia. This layer contains nerve fibers and mast cells. It is the origin of the vasa vasorum, which supply blood to the outer two thirds of the tunica media. 

It is known that when hepatocytes are freshly isolated and cultured under conventional conditions on plastic or collagen coated dishes, gene transcription is drastically depressed and liver specific mRNA declines while the mRNA of structure related genes increases many fold. By contrast, hepatocyte culture on extracellular matrix (ECM), rich in laminin, type IV collagen, and heparin sulfate proteoglycan exhibits increased longevity and maintenance of several liver-specific functions. 

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