Fibulin-3 negatively regulates chondrocyte differentiation.
Fibulin-3 is a member of the fibulin family that has been newly recognized as extracellular matrix proteins. We assessed the effects of fibulin-3 overexpression on chondrocyte differentiation using the clonal murine cell line ATDC5. The ATDC5-FBLN3 stably expressing fibulin-3 protein was spindle-shaped cell compared to the ATDC5-mock with plump cell. The cell growth in the ATDC5-FBLN3 was accelerated in comparison to that in the ATDC5-mock. The ATDC5-FBLN3 was not stained by Alcian blue, nor was there any cartilage aggregate formed after the induction of chondrogenic differentiation. The expression of type II collagen, aggrecan, and type X collagen was completely suppressed in ATDC5-FBLN3 even after the induction of differentiation. The overexpression of fibulin-3 reduced the expression of Sox5 and Sox6, while it maintained the expression of Sox9. These findings suggest that fibulin-3 may play an important role as a negative regulator of chondrocyte differentiation.
Wakabayashi
Toru
T
Department of Orthopaedic Surgery, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu-city, Mie 514-8507, Japan.
Matsumine
Akihiko
A
Nakazora
Shigeto
S
Hasegawa
Masahiro
M
Iino
Takahiro
T
Ota
Hideki
H
Sonoda
Hikaru
H
Sudo
Akihiro
A
Uchida
Atsumasa
A
D000818:Animals; D002356:Cartilage / Q000166:cytology* / Q000378:metabolism; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism; D020219:Chondrogenesis; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051379:Mice; D011509:Proteoglycans / Q000096:biosynthesis; D055758:SOX9 Transcription Factor / Q000378:metabolism; D055755:SOXD Transcription Factors / Q000378:metabolism
C119630:EFEMP1 protein, human; D016326:Extracellular Matrix Proteins; D011509:Proteoglycans; D055758:SOX9 Transcription Factor; D055755:SOXD Transcription Factors; C089186:Sox5 protein, mouse; C095939:Sox6 protein, mouse