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.
Iqbal
J
J
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
Dudhia
J
J
Bird
J L
JL
Bayliss
M T
MT
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