title: The structure, location, and function of perlecan, a prominent pericellular proteoglycan of fetal, postnatal, and mature hyaline cartilages.
abstract: The aim of this study was to immunolocalize perlecan in human fetal, postnatal, and mature hyaline cartilages and to determine information on the structure and function of chondrocyte perlecan. Perlecan is a prominent component of human fetal (12-14 week) finger, toe, knee, and elbow cartilages; it was localized diffusely in the interterritorial extracellular matrix, densely in the pericellular matrix around chondrocytes, and to small blood vessels in the joint capsules and perichondrium. Aggrecan had a more intense distribution in the marginal regions of the joint rudiments and in para-articular structures. Perlecan also had a strong pericellular localization pattern in postnatal (2-7 month) and mature (55-64 year) femoral cartilages, whereas aggrecan had a prominent extracellular matrix distribution in these tissues. Western blotting identified multiple perlecan core protein species in extracts of the postnatal and mature cartilages, some of which were substituted with heparan sulfate and/or chondroitin sulfate and some were devoid of glycosaminoglycan substitution. Some perlecan core proteins were smaller than intact perlecan, suggesting that proteolytic processing or alternative splicing had occurred. Surface plasmon resonance and quartz crystal microbalance with dissipation experiments demonstrated that chondrocyte perlecan bound fibroblast growth factor (FGF)-1 and -9 less efficiently than endothelial cell perlecan. The latter perlecan supported the proliferation of Baf-32 cells transfected with FGFR3c equally well with FGF-1 and -9, whereas chondrocyte perlecan only supported Baf-32 cell proliferation with FGF-9. The function of perlecan therefore may not be universal but may vary with its cellular origin and presumably its structure.
authors.affiliation: The Raymond Purves Research Laboratories, Institute of Bone and Joint , University of Sydney at the Royal North Shore Hospital of Sydney, St. Leonards, New South Wales 2065, Australia. jmelrose@med.usyd.edu.au
authors.forename: James
authors.initials: J
authors.lastname: Melrose
authors.forename: Peter
authors.initials: P
authors.lastname: Roughley
authors.forename: Sarah
authors.initials: S
authors.lastname: Knox
authors.forename: Susan
authors.initials: S
authors.lastname: Smith
authors.forename: Megan
authors.initials: M
authors.lastname: Lord
authors.forename: John
authors.initials: J
authors.lastname: Whitelock
mesh_terms: D000367:Age Factors; D017398:Alternative Splicing; D002356:Cartilage / Q000378:metabolism / Q000473:pathology; D019902:Chondrocytes / Q000378:metabolism; D005269:Femur / Q000473:pathology; D016220:Fibroblast Growth Factor 1 / Q000378:metabolism; D051525:Fibroblast Growth Factor 9 / Q000378:metabolism; D005786:Gene Expression Regulation; D019812:Heparan Sulfate Proteoglycans / Q000502:physiology*; D006801:Humans; D051457:Hyaline Cartilage / Q000378:metabolism / Q000502:physiology*; D007223:Infant; D008875:Middle Aged; D020349:Surface Plasmon Resonance; D013997:Time Factors
chemical_list: C496459:FGF9 protein, human; D051525:Fibroblast Growth Factor 9; D019812:Heparan Sulfate Proteoglycans; D016220:Fibroblast Growth Factor 1; C071927:perlecan