Age-related effects of TGF-beta on proteoglycan synthesis in equine articular cartilage.
The synthesis of proteoglycans was measured in normal equine articular cartilage of ages 9 months to 20 years and the effect of TGF-beta1 on this activity was investigated. The rate of incorporation of [(35)S]Na(2)SO(4) decreased with age as did the responsiveness of the tissue to the growth factor. The enhanced synthesis of proteoglycan induced at all ages by TGF-beta1 was down-regulated by IL-1 beta and retinoic acid. The expression of mRNA for TGF-beta1, 2, and 3 was also measured, and although the level of TGF-beta1 was highest at all ages, the expression of each growth factor decreased with age.
Department of Veterinary Basic Sciences and Farm Animal and Equine Medicine and Surgery, Royal Veterinary College, Royal College Street, London, NW1 0TU, United Kingdom. jiqbal@rvc.ac.uk
J
J
Iqbal
J
J
Dudhia
J L
JL
Bird
M T
MT
Bayliss
D000367:Age Factors; D000375:Aging / Q000378:metabolism*; D000818:Animals; D001667:Binding, Competitive; D002358:Cartilage, Articular / Q000187:drug effects / Q000378:metabolism*; D006133:Growth Substances / Q000494:pharmacology; D006736:Horses / Q000196:embryology / Q000378:metabolism*; D066298:In Vitro Techniques; D007375:Interleukin-1 / Q000494:pharmacology; D020033:Protein Isoforms / Q000378:metabolism / Q000494:pharmacology; D011509:Proteoglycans / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000096:biosynthesis; D012016:Reference Values; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013431:Sulfates / Q000378:metabolism / Q000493:pharmacokinetics; D013462:Sulfur Radioisotopes; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D014212:Tretinoin / Q000494:pharmacology
D006133:Growth Substances; D007375:Interleukin-1; D020033:Protein Isoforms; D011509:Proteoglycans; D012333:RNA, Messenger; D013431:Sulfates; D013462:Sulfur Radioisotopes; D016212:Transforming Growth Factor beta; D014212:Tretinoin