[PDF][PDF] Hedgehog signaling enhances core-binding factor a1 and receptor activator of nuclear factor-kappaB ligand (RANKL) gene expression in chondrocytes

M Takamoto, K Tsuji, T Yamashita… - Journal of …, 2003 - joe.bioscientifica.com
M Takamoto, K Tsuji, T Yamashita, H Sasaki, T Yano, Y Taketani, T Komori, A Nifuji, M Noda
Journal of endocrinology, 2003joe.bioscientifica.com
Hedgehog signaling is considered to play a crucial role in chondrogenesis by regulation
through a network of cytokine actions, which is not fully understood. We examined the effect
of hedgehog signaling on the expression of core-binding factor a1 (Cbfa1), a critical
transcription factor for the development of bone and cartilage. Primary chondrocytes
prepared from the costal cartilage of newborn mice were treated with N-terminal fragment of
recombinant murine sonic hedgehog (rmShh-N). Northern blot analysis indicated that Cbfa1 …
Abstract
Hedgehog signaling is considered to play a crucial role in chondrogenesis by regulation through a network of cytokine actions, which is not fully understood. We examined the effect of hedgehog signaling on the expression of core-binding factor a1 (Cbfa1), a critical transcription factor for the development of bone and cartilage. Primary chondrocytes prepared from the costal cartilage of newborn mice were treated with N-terminal fragment of recombinant murine sonic hedgehog (rmShh-N). Northern blot analysis indicated that Cbfa1 mRNA expression levels in the chondrocyte cultures were elevated by the treatment with rmShh-N. rmShh-N treatment enhanced 1· 8 kb Cbfa1 promoter activity in chondrocytes, suggesting the presence of transcriptional control. As
Cbfa1-binding site (s) have been located in the promoter of the receptor activator of nuclear factor-κB (RANK) ligand (RANKL) gene, we also examined RANKL expression. rmShh-N treatment upregulated RANKL and RANK mRNA expression levels in chondrocytes. Interestingly, RANKL suppressed the hedgehog enhancement of alkaline phosphatase activity in chondrocytes, suggesting the presence of a link between these signaling molecules. We conclude that hedgehog signaling activates Cbfa1 gene expression through its promoter in chondrocytes, and also activates and interacts with RANKL to maintain cartilage development.
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