An N-terminal peptide from link protein stimulates proteoglycan biosynthesis in human articular cartilage in vitro.
OBJECTIVE
To determine the effects of a synthetic N-terminal peptide from link protein on the synthesis of proteoglycans by human articular cartilage.


METHODS
Explants from adult knee cartilage were maintained for 4 days in serum-free Dulbecco's modified Eagle's medium. Peptides were added for the final 2 days of culture. Synthesis of proteoglycans and proteins was measured by the incorporation of 35S-sulfate and 3H-serine. The sizes, sulfation patterns, and serine: sulfate ratios of newly synthesized glycosaminoglycans were measured by gel chromatography, high performance liquid chromatography, and ion-exchange chromatography.


RESULTS
The N-terminal peptide stimulated proteoglycan synthesis in cartilage from a wide age range of patients of both sexes. The newly synthesized glycosaminoglycans were identical in size and composition to those of control tissues, and their serine:sulfate ratios remained unchanged.


CONCLUSIONS
This N-terminal peptide, which can be liberated from proteoglycan aggregates by proteolysis, potently stimulated the synthesis of proteoglycans with normal glycosaminoglycan chains. The results suggest that the N-terminal peptide may have a regulatory role in maintaining the integrity of human cartilage matrix.
McKenna
L A
LA
The Kennedy Institute of Rheumatology, London, UK.
Liu
H
H
Sansom
P A
PA
Dean
M F
MF
D000293:Adolescent; D000328:Adult; D002358:Cartilage, Articular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D002478:Cells, Cultured; D002648:Child; D016326:Extracellular Matrix Proteins; D005260:Female; D006801:Humans; D007719:Knee Joint; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000494:pharmacology*; D011506:Proteins / Q000494:pharmacology*; D011509:Proteoglycans / Q000096:biosynthesis* / Q000494:pharmacology; D000099249:Proteoglycan Link Protein
D016326:Extracellular Matrix Proteins; D010446:Peptide Fragments; D011506:Proteins; D011509:Proteoglycans; D000099249:Proteoglycan Link Protein