Expression of adrenomedullin and its receptor by chondrocyte phenotype cells.
For clarifying a process of de-differentiation in culturing chondrocytes, the present study was undertaken to investigate the secretion of adrenomedullin (AM) by chondrocyte phenotype cells and whether or not AM effects this proliferation in a cAMP-dependent fashion. Chondrocyte phenotype cells expressed AM and the AM receptor, and secreted high concentration of AM into the culture medium. When added to cultures, AM increased the intracellular cAMP level and decreased the number of these cells in a similar concentration-dependent fashion. Addition of forskolin and dibutyryl-cAMP caused a significant decrease in the number of these cells. Furthermore, the effect of AM was inhibited by a cAMP-dependent protein kinase A inhibitor (H89). The present findings indicate that AM has an autocrine/paracrine type of anti-proliferative effect on these cells mediated via a cAMP-dependent pathway and raise the possibility that AM plays a role in the local modulation of a process of de-differentiation by culturing chondrocyte phenotype cells.
Chosa
Etsuo
E
Department of Orthopaedic Surgery, Miyazaki Medical College, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan. chosa@post.miyazaki-med.ac.jp
Hamada
Hiroaki
H
Kitamura
Kazuo
K
Kuwasako
Kenji
K
Yanagita
Toshihiko
T
Eto
Tanenao
T
Tajima
Naoya
N
D053607:Adrenomedullin; D003994:Bucladesine / Q000378:metabolism; D002454:Cell Differentiation; D002455:Cell Division; D002478:Cells, Cultured; D019902:Chondrocytes / Q000378:metabolism*; D005576:Colforsin / Q000494:pharmacology; D017077:Culture Media, Conditioned / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D007546:Isoquinolines / Q000494:pharmacology; D008565:Membrane Proteins / Q000378:metabolism; D010455:Peptides / Q000378:metabolism*; D010641:Phenotype; D011863:Radioimmunoassay; D058261:Receptor Activity-Modifying Proteins; D058265:Receptors, Adrenomedullin; D018000:Receptors, Peptide / Q000096:biosynthesis*; D013449:Sulfonamides; D013997:Time Factors
D017077:Culture Media, Conditioned; D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D007546:Isoquinolines; D008565:Membrane Proteins; D010455:Peptides; D058261:Receptor Activity-Modifying Proteins; D058265:Receptors, Adrenomedullin; D018000:Receptors, Peptide; D013449:Sulfonamides; D053607:Adrenomedullin; D005576:Colforsin; D003994:Bucladesine; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; C063509:N-(2-(4-bromocinnamylamino)ethyl)-5-isoquinolinesulfonamide