Combined effects of growth factors and static mechanical compression on meniscus explant biosynthesis.
OBJECTIVE
To compare the actions of fibroblast growth factor-basic (bFGF), insulin-like growth factor-I (IGF-I), platelet derived growth factor-AB (PDGF-AB), and transforming growth factor-beta 1 (TGF-beta1) on bovine meniscus tissue explants with and without static mechanical compression.


METHODS
Meniscus tissue explants were cultured in a serum-free environment supplemented with an individual growth factor (1) over a range of concentrations for 4 days, (2) at a single concentration for 2-14 days, and (3) at a single concentration for 4 days coupled with graded levels of static compression. Explants were analyzed for accumulation of newly synthesized proteoglycan and total protein as measured by 35S-sulfate and 3H-proline incorporation, respectively.


RESULTS
Over the range of chosen concentrations, TGF-beta1 was the most potent stimulator of both protein and proteoglycan production, whereas bFGF was the least effective stimulator. Over a 2-week period for all four growth factors, the stimulation of proteoglycan production was sustained while there was no stimulation of protein production during this period. The superposition of static mechanical compression inhibited matrix production in the presence of each anabolic factor, with comparable inhibition relative to uncompressed controls for all factors.


CONCLUSIONS
The growth factors chosen exhibited an anabolic effect on the meniscus tissue explants, encouraging matrix production and deposition. The addition of static mechanical compression produced comparable relative inhibition of matrix production for each growth factor, suggesting that static compression and growth factors may modulate meniscal fibrochondrocyte biosynthesis via distinct pathways.
Imler
Stacy M
SM
George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0405, USA.
Doshi
Ashish N
AN
Levenston
Marc E
ME
D000818:Animals; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D006133:Growth Substances / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D008592:Menisci, Tibial / Q000378:metabolism*; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology; D011506:Proteins / Q000378:metabolism*; D011509:Proteoglycans / Q000096:biosynthesis; D013268:Stimulation, Chemical; D013314:Stress, Mechanical; D046509:Tissue Culture Techniques; D016212:Transforming Growth Factor beta / Q000494:pharmacology
D006133:Growth Substances; D010982:Platelet-Derived Growth Factor; D011506:Proteins; D011509:Proteoglycans; D016212:Transforming Growth Factor beta; C095477:platelet-derived growth factor AB; D016222:Fibroblast Growth Factor 2; D007334:Insulin-Like Growth Factor I