| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Submitted on October 20, 2004
Accepted on November 22, 2004
Department of Physiology, University of Santiago de Compostela, Spain.; Complexo Hospitalario Universitario de Santiago, Research Area, Laboratory 4, NEIRID Lab (NeuroEndocrine Interactions in Rheumatology and Inflammatory Diseases), Santiago de Compostela, Spain.; Complexo HospitalarioUniversitario de Santiago, Research Area, Laboratory 1, Molecular and Cellular Cardiology Unit, Santiago de Compostela, Spain; Department of Morphological Sciences, University of Santiago de Compostela; Beth Israel Deaconess Medical Center, Division of Rheumatology, New England Baptist Bone & Joint Institute, Harvard Institutes of Medicine, Boston, USA.; Department of Medicine, Molecular Endocrinology Section (FFC), University of Santiago de Compostela, Spain
* To whom correspondence should be addressed. E-mail: gualillo{at}usc.es.
Ghrelin, the endogenous ligand for the growth hormone secretagogue receptor (GHS-R), is a recently isolated hormone, prevalently expressed in stomach but also in other tissues such as hypothalamus and placenta. This novel acylated peptide acts at a central level to stimulate growth hormone secretion and, notably, to regulate food intake. However, the existence of further, as yet unknown, effects or presence of ghrelin in peripheral tissues cannot be ruled out. In this report, we provide clear evidence for the expression of ghrelin peptide and mRNA in human, mouse and rat chondrocytes. Immunoreactive ghrelin was identified by immunohistochemistry in rat cartilage, being localized prevalently in proliferative and maturative zone of the epiphyseal growth plate, and in mouse and human chondrocytic cell lines. Moreover, ghrelin mRNA was detected by RT-PCR and confirmed by Southern analysis in rat cartilage as well as in mouse and human chondrocytes cell lines. Ghrelin mRNA expression has been studied in rat along early life development showing a stable profile of expression throughout. Although ghrelin expression in chondrocytes suggests the presence of an unexpected autocrine/paracrine pathway, we failed to identify the functional growth hormone secretagogue receptor (GHS-R) type 1A by RT-PCR. On the other hand, binding analysis with 125I ghrelin suggests the presence of specific receptors different from the 1A isotype. Scatchard analysis revealed the presence of two receptors with respectively high and low affinity. Finally, ghrelin, in vitro, was able to significantly stimulate cAMP production and inhibits chondrocytes metabolic activity both in human and murine chondrocytes. In addition ghrelin is able to actively decrease both spontaneous or insulin-induced long chain fatty acid uptake in human and mouse chondrocytes. This study is the first to provide evidence for the presence of this novel peptide in chondrocytes and suggests novel potential roles for this new recognized component of the GH axis in cartilage metabolism.
This article has been cited by other articles:
 |
|
 |
|
  R. Lago, R. Gomez, C. Dieguez, J. J Gomez-Reino, F. Lago, and O. Gualillo Unlike ghrelin, obestatin does not exert any relevant activity in chondrocytes Ann Rheum Dis, October 1, 2007; 66(10): 1399 - 1400. [Full Text] [PDF]
|
|
|
|
 |
|
 D. R. Broom, D. J. Stensel, N. C. Bishop, S. F. Burns, and M. Miyashita Exercise-induced suppression of acylated ghrelin in humans J Appl Physiol, June 1, 2007; 102(6): 2165 - 2171. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. C. R. Prickett, G. K. Barrell, M. Wellby, T. G. Yandle, A. M. Richards, and E. A. Espiner Response of plasma CNP forms to acute anabolic and catabolic interventions in growing lambs Am J Physiol Endocrinol Metab, May 1, 2007; 292(5): E1395 - E1400. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. R. Kraemer and V. D. Castracane Exercise and Humoral Mediators of Peripheral Energy Balance: Ghrelin and Adiponectin Experimental Biology and Medicine, February 1, 2007; 232(2): 184 - 194. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Granata, F. Settanni, L. Biancone, L. Trovato, R. Nano, F. Bertuzzi, S. Destefanis, M. Annunziata, M. Martinetti, F. Catapano, et al. Acylated and Unacylated Ghrelin Promote Proliferation and Inhibit Apoptosis of Pancreatic {beta}-Cells and Human Islets: Involvement of 3',5'-Cyclic Adenosine Monophosphate/Protein Kinase A, Extracellular Signal-Regulated Kinase 1/2, and Phosphatidyl Inositol 3-Kinase/Akt Signaling Endocrinology, February 1, 2007; 148(2): 512 - 529. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Misra, K. K. Miller, V. Stewart, E. Hunter, K. Kuo, D. B. Herzog, and A. Klibanski Ghrelin and Bone Metabolism in Adolescent Girls with Anorexia Nervosa and Healthy Adolescents J. Clin. Endocrinol. Metab., September 1, 2005; 90(9): 5082 - 5087. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Endocrinology | Endocrine Reviews | J. Clin. End. & Metab. |
| Molecular Endocrinology | Recent Prog. Horm. Res. | All Endocrine Journals |
