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WNT5A regulates chondrocyte differentiation through differential use of the CaN/NFAT and IKK/NF-kappaB pathways.
Bradley, Elizabeth W; Drissi, M Hicham.
Afiliação
  • Bradley EW; Department of Orthopeadic Surgery, University of Connecticut Health Center, Farmington, Connecticut 06062, USA.
Mol Endocrinol ; 24(8): 1581-93, 2010 Aug.
Article em En | MEDLINE | ID: mdl-20573686
ABSTRACT
Although genetic evidence demonstrated a requirement for Wnt5a during cartilage development, little is known about the mechanisms underlying Wnt5a-regulated chondrocyte growth and differentiation. We therefore investigated the signaling pathways by which Wnt5a influences chondrogenesis and differentiation to hypertrophy. Wnt5a treatment of chondroprogenitor cells increased chondrocyte hypertrophy and was associated with an increase in nuclear factor of activated T cells (NFAT) and a decrease in nuclear factor-kappaB (NF-kappaB) activation. In contrast, Wnt5a inhibited chondrocyte hypertrophy. This inhibition of hypertrophy occurred with the reciprocal signaling activation, in that a decrease in NFAT and an increase in NF-kappaB activation was observed. Furthermore, the increase in chondroprogenitor cell differentiation with Wnt5a treatment was blocked by calmodulin kinase or NFAT loss of function. In addition, the repression of chondrocyte hypertrophy observed was abrogated by NF-kappaB loss of function. Activation of the NFAT pathway downstream of Wnt5a also negatively regulated NF-kappaB activity, providing evidence of antagonism between these two pathways. Mechanistically, Wnt5a acts to increase chondrocyte differentiation at an early stage through calmodulin kinase /NFAT-dependent induction of Sox9. Conversely, Wnt5a represses chondrocyte hypertrophy via NF-kappaB-dependent inhibition of Runx2 expression. These data indicate that Wnt5a regulates chondrogenesis and chondrocyte hypertrophy in a stage-dependent manner through differential utilization of NFAT- and NF-kappaB-dependent signal transduction.
Assuntos

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Diferenciação Celular / NF-kappa B / Condrócitos / Quinase I-kappa B / Proteínas Wnt / Fatores de Transcrição NFATC Limite: Animals Idioma: En Revista: Mol Endocrinol Ano de publicação: 2010 Tipo de documento: Article

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Diferenciação Celular / NF-kappa B / Condrócitos / Quinase I-kappa B / Proteínas Wnt / Fatores de Transcrição NFATC Limite: Animals Idioma: En Revista: Mol Endocrinol Ano de publicação: 2010 Tipo de documento: Article