The dermatan sulfate proteoglycans of the adult human meniscus

Abstract

The dermatan sulfate proteoglycans decorin and biglycan were extracted from pooled adult human menisci with 4 M guanidinium chloride and purified by successive cesium chloride density gradient centrifugation, ion exchange chromatography, and gel filtration. A final yield of about 2 mg of dermatan sulfate proteoglycan per gram of wet tissue was obtained. The proteoglycan is predominantly decorin with some biglycan, and the dermatan sulfate chains contain about 70% of their uronic acid residues as iduronate and possess about three times as much 4-sulfation as 6-sulfation of their N-acetylgalactosamine residues. On gel filtration under associative conditions, about half of the proteoglycan exhibits self-association. This includes most of the biglycan but also a substantial proportion of decorin. The molecules that show self-association appear to have longer dermatan sulfate chains, though there is no apparent difference in their overall composition. The predominance of decorin in the adult meniscus and its ability to interact both with itself and collagen fibrils is compatible with a role in maintaining tissue integrity and strength.

Elevated synthesis of biglycan and decorin in an ovine annular lesion model of experimental disc degeneration

“…This is certainly consistent with the healing pattern so far observed for annular lesions [14,35], and in animal models of experimental disc degeneration [14, 17-20, 28, 29, 34, 48]. The cells within the fibrocartilaginous knee joint meniscus, which also synthesize DS-PGs [43] and have other characteristics closely similar to those of the AF fibrochondrocytes, also display a similar inability to effect repair of tears or incisions that extend into the dense, avascular mid-substance of this structure [8,9].…”

A Quantitative Study of the Microstructure and Biochemistry of the Medial Meniscal Horn Attachments

“…[1][2][3]37 The inner zone of the main body of the meniscus is thought to experience more compression and be composed of mostly chondrocytic-type cells whereas the outer zone is thought to be exposed to more tension and contain more fibroblastic type cells. 30,44 This corresponds well with data showing that aggrecan was more concentrated in the inner versus the outer zone of the meniscus.…”

Region-specific constitutive gene expression in the adult porcine meniscus

“…3,9 The radially outer region of the meniscus is composed predominantly of type I collagen fiber bundles that are aligned along the circumferential direction of the tissue, along with lesser amounts of minor collagens including types III and V and small proteoglycans. 4,[10][11][12] In contrast, the inner radial region is composed of both types I and II collagen fibers that are organized into a close network of aligned thick and fine mesh-like strands [10][11][12] and contains higher amounts of aggregating proteoglycans than the outer region. 13,14 The extracellular matrix of the meniscus is maintained by sparsely distributed cells that were originally classified into two populations: fusiform cells lining the superficial region and rounded fibrochondrocytes that synthesize type I collagen and are localized in the main body of the meniscus.…”

“…20 In contrast, cells of the inner regions are more rounded with few to no processes, are still referred to as fibrochondrocytes, 17 and are negative for CD34. 20 Biochemical and immunolocalization studies have suggested that the radial inner meniscus may exhibit similarities to articular cartilage including higher levels of type II collagen protein [10][11][12]21 simultaneous with higher amounts of aggrecan.…”