Distribution of the transcription factors Sox9, AP-2, and [delta]EF1 in adult murine articular and meniscal cartilage and growth plate.
The control of extracellular matrix (ECM) production is important for the development, maintenance, and repair of cartilage tissues. Matrix molecule synthesis is generally regulated by the rate of gene transcription determined by DNA transcription factors. We have shown that transcription factors Sox9, AP-2, and [delta]EF1 are able to alter the rate of CD-RAP transcription in vitro: Sox9 upregulates, AP-2 exhibits biphasic effects, and [delta]EF1 represses expression of the CD-RAP gene. To correlate these in vitro activities in vivo, transcription factors were co-immunolocalized with ECM proteins in three different cartilage tissues in which the rates of biosynthesis are quite different: articular, meniscal, and growth plate. Immunoreactivities of type II collagen and CD-RAP were higher in growth plate than in either the articular or meniscal cartilages and correlated positively with Sox9 protein. Sox9 staining decreased with hypertrophy and was low in articular and meniscal cartilages. In contrast, AP-2 and [delta]EF1 were low in proliferating chondrocytes but high in lower growth plate, articular, and meniscal cartilages. This increase was also accompanied by intense nuclear staining. These immunohistochemical results are the first to localize both [delta]EF1 and AP-2 to adult articular, meniscal, and growth plate cartilages and provide in vivo correlation of previous molecular biological studies.
Washington University School of Medicine at Barnes-Jewish Hospital, Department of Orthopaedic Surgery, St Louis, Missouri 63110, USA.
Sherri R
SR
Davies
Shinji
S
Sakano
Yong
Y
Zhu
Linda J
LJ
Sandell
D000818:Animals; D002358:Cartilage, Articular / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D019902:Chondrocytes / Q000378:metabolism / Q000648:ultrastructure; D024043:Collagen Type II / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D016326:Extracellular Matrix Proteins; D006132:Growth Plate / Q000378:metabolism*; D006609:High Mobility Group Proteins / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D008592:Menisci, Tibial / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D011506:Proteins / Q000378:metabolism; D055758:SOX9 Transcription Factor; D050656:Transcription Factor AP-2; D014157:Transcription Factors / Q000378:metabolism*; D000071799:Zinc Finger E-box-Binding Homeobox 1
D024043:Collagen Type II; D004268:DNA-Binding Proteins; D016326:Extracellular Matrix Proteins; D006609:High Mobility Group Proteins; D018398:Homeodomain Proteins; D011506:Proteins; D055758:SOX9 Transcription Factor; D050656:Transcription Factor AP-2; D014157:Transcription Factors; D000071799:Zinc Finger E-box-Binding Homeobox 1; C513263:Mia protein, mouse; C527933:Sox9 protein, mouse; C000630720:ZEB1 protein, rat; C519422:ZEB1 protein, mouse