Constitutive and inducible expression of endothelin-1 in primary rat articular chondrocyte culture.
Endothelin-1 (ET-1) mRNA expression and protein production were examined in primary rat articular chondrocyte (AC) cultures by RT-PCR and radioimmunoassay, respectively. We found that serum-starved rat AC express ET-1 mRNA and produce the peptide constitutively. Treatment of cells with 10% FCS resulted in a marked increase in ET-1 levels with a peak at 48 h (5.6-fold). A similar concentration-dependent effect was also obtained in the presence of interleukin 1beta (3.1-fold), tumour necrosis factor alpha (3. 5-fold), lipopolysaccharide (2.7-fold), transforming growth factor beta1 (3.5-fold), epidermal growth factor (5.0-fold) and insulin-like growth factor-I (4.4-fold). In addition, ET-1 was found to induce, over a period of 24 h, a potent concentration-dependent stimulation of DNA synthesis in rat AC. These findings demonstrate for the first time the constitutive expression and production of ET-1 by rat AC which could be modulated by several cytokines and growth factors, suggesting a possible role for ET-1 in autocrine regulation of chondrocyte function.
Khatib
A M
AM
INSERM-Unit 349, Cell and Molecular Biology of Bone and Cartilage, Lariboisiere Hospital, Paris Cedex 10, 75475, France.
Lomri
A
A
Moldovan
F
F
Fiet
J
J
Mitrovic
D R
DR
D000818:Animals; D002358:Cartilage, Articular / Q000166:cytology / Q000378:metabolism*; D002455:Cell Division; D002478:Cells, Cultured; D019332:Endothelin-1 / Q000096:biosynthesis* / Q000235:genetics; D019084:Fluorescent Antibody Technique, Indirect; D015870:Gene Expression; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger; D051381:Rats; D017208:Rats, Wistar; D013194:Staining and Labeling; D014158:Transcription, Genetic
D019332:Endothelin-1; D012333:RNA, Messenger