title: TIP39/parathyroid hormone type 2 receptor signaling is a potent inhibitor of chondrocyte proliferation and differentiation.
abstract: Tuberoinfundibular peptide of 39 residues (TIP39) is a member of the parathyroid hormone (PTH) family of peptide hormones that exerts its function by interacting with the PTH type 2 receptor (PTH2R). Presently, no known function has been attributed to this signaling pathway in the developing skeleton. We observed that TIP39 and PTH2R were present in the newborn mouse growth plate, with the receptor localizing in the resting zone whereas ligand expression was restricted exclusively in prehypertrophic and hypertrophic chondrocytes. By 8 wk of life, PTH2R, and to a lesser degree TIP39, immunoreactivity was present in articular chondrocytes. We therefore sought to investigate the role of TIP39/PTH2R signaling in chondrocytes by generating stably transfected CFK2 chondrocytic cells overexpressing PTH2R (CFK2R). TIP39 treatment of CFK2R clones in culture inhibited their proliferation by restricting cells at the G(0)/G(1) phase of the cell cycle, coupled with decreased expression and activity of cyclin-dependent kinases Cdk2 and Cdk4, while p21, an inhibitor of Cdks, was upregulated. In addition, TIP39 treatment decreased expression of differentiation markers in these cells associated with marked alterations in extracellular matrix and metalloproteinase expression. Transcription of Sox9, the master regulator of cartilage differentiation, was reduced in TIP39-treated CFK2R clones. Moreover, Sox9 promoter activity, as measured by luciferase reporter assay, was markedly diminished after TIP39 treatment. In summary, our results show that TIP39/PTH2R signaling inhibits proliferation and alters differentiation of chondrocytes by modulating SOX9 expression, thereby substantiating the functional significance of this signaling pathway in chondrocyte biology.
authors.affiliation: Div. of Endocrinology, Dept. of Medicine, Sir Mortimer B. Davis-Jewish General Hosp., 3755 Cote Ste Catherine Road, Montreal, QC, Canada H3T 1E2.
authors.forename: Dibiyendu
authors.initials: D
authors.lastname: Panda
authors.forename: David
authors.initials: D
authors.lastname: Goltzman
authors.forename: Harald
authors.initials: H
authors.lastname: Jüppner
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Karaplis
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D015152:Blotting, Northern; D015153:Blotting, Western; D001846:Bone Development / Q000187:drug effects / Q000235:genetics; D001842:Bone and Bones / Q000378:metabolism; D002358:Cartilage, Articular / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects; D019902:Chondrocytes / Q000378:metabolism*; D051357:Cyclin-Dependent Kinase 2 / Q000378:metabolism; D003513:Cycloheximide; D047468:Immunoprecipitation; D051379:Mice; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000502:physiology*; D011500:Protein Synthesis Inhibitors; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D000072260:RNA Splicing Factors; D016601:RNA-Binding Proteins; D060888:Real-Time Polymerase Chain Reaction; D044183:Receptor, Parathyroid Hormone, Type 2 / Q000096:biosynthesis / Q000502:physiology*; D055758:SOX9 Transcription Factor / Q000096:biosynthesis / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects; D013936:Thymidine / Q000378:metabolism; D033921:Vesicular Transport Proteins / Q000096:biosynthesis / Q000502:physiology*
chemical_list: D015415:Biomarkers; D009687:Nuclear Proteins; D011500:Protein Synthesis Inhibitors; D000072260:RNA Splicing Factors; D016601:RNA-Binding Proteins; D044183:Receptor, Parathyroid Hormone, Type 2; D055758:SOX9 Transcription Factor; C527933:Sox9 protein, mouse; C412229:Tfip11 protein, mouse; D033921:Vesicular Transport Proteins; D012313:RNA; D003513:Cycloheximide; C495893:Cdk2 protein, mouse; D051357:Cyclin-Dependent Kinase 2; D013936:Thymidine
references.citation: J Cell Biol. 1996 Apr;133(2):457-68
references.pmid: 8609176
references.citation: J Clin Invest. 1998 Jul 1;102(1):34-40
references.pmid: 9649554
references.citation: Nat Neurosci. 1999 Nov;2(11):941-3
references.pmid: 10526330
references.citation: Dev Biol. 2006 Apr 1;292(1):116-28
references.pmid: 16476422
references.citation: Endocrinology. 1996 Oct;137(10):4285-97
references.pmid: 8828488
references.citation: J Clin Invest. 2001 Jan;107(1):35-44
references.pmid: 11134178
references.citation: Bone. 1993 May-Jun;14(3):341-5
references.pmid: 8395866
references.citation: Arthritis Res Ther. 2007;9(5):R108
references.pmid: 17958892
references.citation: Biochem Biophys Res Commun. 2005 Mar 18;328(3):666-78
references.pmid: 15694400
references.citation: Am J Med Genet A. 2006 Dec 1;140(23):2646-706
references.pmid: 17103447
references.citation: Annu Rev Physiol. 1998;60:431-60
references.pmid: 9558472
references.citation: Ann Anat. 2008;190(4):305-15
references.pmid: 18602255
references.citation: Nature. 2003 May 15;423(6937):332-6
references.pmid: 12748651
references.citation: Br J Rheumatol. 1995 Apr;34(4):306-10
references.pmid: 7788143
references.citation: J Cell Physiol. 1996 Oct;169(1):33-41
references.pmid: 8841420
references.citation: Endocrinology. 1998 Dec;139(12):5255-8
references.pmid: 9832466
references.citation: J Cell Biol. 1994 Sep;126(6):1611-23
references.pmid: 8089190
references.citation: Ann N Y Acad Sci. 2006 Apr;1068:1-13
references.pmid: 16831900
references.citation: Nature. 2008 Jun 12;453(7197):930-4
references.pmid: 18454134
references.citation: Eur J Hum Genet. 2006 Dec;14(12):1280-7
references.pmid: 16912703
references.citation: Proc Natl Acad Sci U S A. 2001 Jan 2;98(1):160-5
references.pmid: 11120880
references.citation: J Cell Biol. 2000 Feb 7;148(3):543-56
references.pmid: 10662779
references.citation: Arthritis Res. 2002;4 Suppl 3:S39-49
references.pmid: 12110122
references.citation: Ann Rheum Dis. 1998 Sep;57(9):527-32
references.pmid: 9849311
references.citation: Mol Cell Biol. 1997 Apr;17(4):2336-46
references.pmid: 9121483
references.citation: Endocrinology. 2008 Sep;149(9):4292-300
references.pmid: 18483145
references.citation: Genes Dev. 1994 Feb 1;8(3):277-89
references.pmid: 8314082
references.citation: Spine (Phila Pa 1976). 2001 Dec 15;26(24):2666-72
references.pmid: 11740352
references.citation: Endocrinology. 1999 Jul;140(7):3363-71
references.pmid: 10385434
references.citation: Matrix Biol. 2001 Dec;20(8):543-53
references.pmid: 11731271
references.citation: J Biol Chem. 1998 Feb 13;273(7):3830-7
references.pmid: 9461563
references.citation: J Bone Miner Res. 1993 Apr;8(4):475-84
references.pmid: 8475797
references.citation: Matrix Biol. 1998 Mar;16(9):529-40
references.pmid: 9569122
references.citation: J Biol Chem. 1995 Jun 30;270(26):15455-8
references.pmid: 7797535
references.citation: Nat Genet. 1995 Jan;9(1):15-20
references.pmid: 7704017
references.citation: Proc Natl Acad Sci U S A. 2004 Dec 7;101(49):17192-7
references.pmid: 15563592
references.citation: Science. 1995 Apr 7;268(5207):98-100
references.pmid: 7701349
references.citation: Front Neuroendocrinol. 2000 Oct;21(4):349-83
references.pmid: 11013069
references.citation: J Biol Chem. 2001 Nov 2;276(44):41229-36
references.pmid: 11514554
references.citation: Endocrinology. 2001 Feb;142(2):704-9
references.pmid: 11159842
references.citation: Genes Brain Behav. 2008 Nov;7(8):933-42
references.pmid: 18700839
references.citation: J Biochem. 2009 Feb;145(2):207-16
references.pmid: 19038999
references.citation: Science. 1996 Aug 2;273(5275):663-6
references.pmid: 8662561