| Theme | Cell biology cartilage | |
|---|---|---|
| Title | Hedgehog and chondrocytes | |
| Publish Date | 2003/06 | |
| Author | Shinsuke Ohba | Division of Tissue Engineering, University of Tokyo Hospital |
| Author | Ung-il Chung Yuichi Tei | Division of Tissue Engineering, University of Tokyo Hospital |
| [ Summary ] | Hedgehog (Hh) is one of the Drosophila segment-polarity genes. Its signal is transduced intracellularly via Patched (Ptc) and Smoothened (Smo), which then activate a transcriptional factor, Cubitus Interruptus (Ci). Among three mammalian homologs of Drosophila hedgehog, Indian hedgehog (Ihh) plays an important role in endochondral bone formation. Analyses of genetically manipulated mice have shown that Ihh directly regulates proliferation of growth plate chondrocytes, and that Ihh forms a negative feedback loop with PTHrP that regulates proliferation and differentiation of growth plate chondrocytes. Ihh has been shown to be essential for differentiation of osteoprogenitor cells around the growth plate into osteoblasts. Several human diseases are caused by inappropriate signal transduction of the Hh pathway. | |