Repression of anti-proliferative factor Tob1 in osteoarthritic cartilage.
Osteoarthritis is the most common degenerative disorder of the modern world. However, many basic cellular features and molecular processes of the disease are poorly understood. In the present study we used oligonucleotide-based microarray analysis of genes of known or assumed relevance to the cellular phenotype to screen for relevant differences in gene expression between normal and osteoarthritic chondrocytes. Custom made oligonucleotide DNA arrays were used to screen for differentially expressed genes in normal (n = 9) and osteoarthritic (n = 10) cartilage samples. Real-time polymerase chain reaction (PCR) with gene-specific primers was used for quantification. Primary human adult articular chondrocytes and chondrosarcoma cell line HCS-2/8 were used to study changes in gene expression levels after stimulation with interleukin-1beta and bone morphogenetic protein, as well as the dependence on cell differentiation. In situ hybridization with a gene-specific probe was applied to detect mRNA expression levels in fetal growth plate cartilage. Overall, more than 200 significantly regulated genes were detected between normal and osteoarthritic cartilage (P < 0.01). One of the significantly repressed genes, Tob1, encodes a protein belonging to a family involved in silencing cells in terms of proliferation and functional activity. The repression of Tob1 was confirmed by quantitative PCR and correlated to markers of chondrocyte activity and proliferation in vivo. Tob1 expression was also detected at a decreased level in isolated chondrocytes and in the chondrosarcoma cell line HCS-2/8. Again, in these cells it was negatively correlated with proliferative activity and positively with cellular differentiation. Altogether, the downregulation of the expression of Tob1 in osteoarthritic chondrocytes might be an important aspect of the cellular processes taking place during osteoarthritic cartilage degeneration. Activation, the reinitiation of proliferative activity and the loss of a stable phenotype are three major changes in osteoarthritic chondrocytes that are highly significantly correlated with the repression of Tob1 expression.
Gebauer
Mathias
M
Aventis Pharma Deutschland, Functional Genomics, Sanofi-Aventis, Frankfurt, Germany. mathias.gebauer@aventis.com
Saas
Joachim
J
Haag
Jochen
J
Dietz
Uwe
U
Takigawa
Masaharu
M
Bartnik
Eckart
E
Aigner
Thomas
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology; D002358:Cartilage, Articular / Q000378:metabolism*; D002454:Cell Differentiation; D002455:Cell Division; D045744:Cell Line, Tumor / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D019902:Chondrocytes / Q000187:drug effects / Q000378:metabolism; D002813:Chondrosarcoma / Q000473:pathology; D005260:Female; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D017403:In Situ Hybridization; D007375:Interleukin-1 / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000502:physiology*; D019394:Ki-67 Antigen / Q000032:analysis; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D010003:Osteoarthritis / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D025521:Tumor Suppressor Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*
C525819:BMP7 protein, human; D055419:Bone Morphogenetic Protein 7; D019485:Bone Morphogenetic Proteins; D007375:Interleukin-1; D047908:Intracellular Signaling Peptides and Proteins; D019394:Ki-67 Antigen; D012333:RNA, Messenger; C098669:TOB1 protein, human; D016212:Transforming Growth Factor beta; D025521:Tumor Suppressor Proteins
Dev Dyn. 1999 Nov;216(3):233-43
10590475
Ann Rheum Dis. 1962 Mar;21:45-50
14471899
Arthritis Rheum. 2000 Aug;43(8):1742-8
10943864
Anal Biochem. 2000 Nov 1;286(1):80-5
11038277
J Clin Invest. 2001 Jan;107(1):35-44
11134178
Cell. 2000 Dec 22;103(7):1085-97
11163184
Arthritis Res. 2001;3(2):107-13
11178118
J Cell Physiol. 2001 May;187(2):155-65
11267995
FEBS Lett. 2001 May 25;497(2-3):67-72
11377414
Arthritis Rheum. 2001 Jun;44(6):1304-12
11407689
Nat Immunol. 2001 Dec;2(12):1174-82
11694881
Nat Immunol. 2001 Dec;2(12):1097-8
11725297
Cell Mol Life Sci. 2002 Jan;59(1):5-18
11846033
Arthritis Rheum. 2002 Oct;46(10):2648-57
12384923
J Bone Miner Res. 2002 Dec;17(12):2141-50
12469908
J Biochem Mol Biol. 2002 Nov 30;35(6):609-14
12470596
Mech Dev. 2003 May;120(5):629-37
12782279
Bioinformatics. 2003 Aug 12;19(12):1469-76
12912826
J Bone Joint Surg Am. 2003;85-A Suppl 3:59-66
12925611
Matrix Biol. 2003 Jun;22(4):363-72
12935820
Clin Exp Rheumatol. 2004 Jan-Feb;22(1):103-6
15005012
J Bone Joint Surg Am. 1971 Apr;53(3):523-37
5580011
Clin Orthop Relat Res. 1972 May;84:197-9
5032842
J Bone Joint Surg Br. 1973 Aug;55(3):588-94
4729024
Biochem Biophys Res Commun. 1982 Dec 31;109(4):1094-101
7168757
J Immunol. 1984 Oct;133(4):1710-5
6206131
Arthritis Rheum. 1986 Aug;29(8):1039-49
3741515
Cancer Res. 1989 Jul 15;49(14):3996-4002
2736538
Scand J Rheumatol. 1991;20(3):172-82
2068539
Int J Cancer. 1991 Jul 9;48(5):717-25
2071232
Virchows Arch B Cell Pathol Incl Mol Pathol. 1992;62(6):337-45
1280884
J Clin Invest. 1993 Mar;91(3):829-37
7680669
Jpn J Cancer Res. 1994 Apr;85(4):364-71
8200849
Exp Cell Res. 1994 Nov;215(1):9-16
7525324
Oncogene. 1996 Feb 15;12(4):705-13
8632892
J Clin Invest. 1997 Apr 1;99(7):1534-45
9119997
Am J Pathol. 1997 Jun;150(6):2133-41
9176404
Arthritis Rheum. 1998 Jun;41(6):986-96
9627008
J Histochem Cytochem. 2000 Feb;48(2):239-50
10639490