Abstract
Coordinate expression of BMPs and their receptors and inhibitors is likely necessary for physiologic BMP regulation and activity. To characterize the expression of such factors in fetal, normal adult, and endโstage osteoarthritic articular cartilage, samples from these sources were analyzed. PCRโamplified sequences (BMPs 1โ11), receptors (IA, IB, II), TGFโฮฒ~1~, TGFโฮฒ~2~, inhibitors noggin and follistatin, CDMPโ1, COMP, and GAPDH from cDNAs generated from extracted total RNA were resolved by gel electrophoresis. Protein levels of BMPs 3, 7, and 8 were also analyzed by SDSโPAGE and Western blotting. RTโPCR revealed that BMPs 1, 2, 4โ6, and 11, BMPRโIA and II, noggin, follistatin, CDMPโ1, COMP, and GAPDH mRNAs were expressed in similar fashion in both fetal and adult (normal or osteoarthritic) cartilage. BMPs 9 and 10 mRNAs were not expressed in either group. BMPs 7, 8, and BMPRโIB mRNAs were consistently expressed in fetal but not in adult cartilage. BMPโ3 mRNA was expressed in fetal and normal adult, but not in osteoarthritic samples. TGFโฮฒ~1~ was expressed in both adult normal and osteoarthritic, but not fetal, samples. Similarly, Western blotting demonstrated BMPs 7 and 8 to be present in fetal but not in adult samples. BMPโ3 protein was present in fetal and adult normal samples, to a lesser extent, but absent in osteoarthritic cartilage. ยฉ 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.