Tissue-specific calibration of extracellular matrix material properties by transforming growth factor-β and Runx2 in bone is required for hearing

Department of Otolaryngology, Head and Neck Surgery, University of California at San Francisco, San Francisco, California 94143, USA.
EMBO Reports (Impact Factor: 9.06). 10/2010; 11(10):765-71. DOI: 10.1038/embor.2010.135
Source: PubMed

ABSTRACT Physical cues, such as extracellular matrix stiffness, direct cell differentiation and support tissue-specific function. Perturbation of these cues underlies diverse pathologies, including osteoarthritis, cardiovascular disease and cancer. However, the molecular mechanisms that establish tissue-specific material properties and link them to healthy tissue function are unknown. We show that Runx2, a key lineage-specific transcription factor, regulates the material properties of bone matrix through the same transforming growth factor-β (TGFβ)-responsive pathway that controls osteoblast differentiation. Deregulated TGFβ or Runx2 function compromises the distinctly hard cochlear bone matrix and causes hearing loss, as seen in human cleidocranial dysplasia. In Runx2+/⁻ mice, inhibition of TGFβ signalling rescues both the material properties of the defective matrix, and hearing. This study elucidates the unknown cause of hearing loss in cleidocranial dysplasia, and demonstrates that a molecular pathway controlling cell differentiation also defines material properties of extracellular matrix. Furthermore, our results suggest that the careful regulation of these properties is essential for healthy tissue function.

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Available from: Grayson William Marshall, Sep 27, 2015
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    • "Therefore, patients with CCD should be evaluated routinely by an otolaryngologist and should undergo complete audiological testing.[14] Deregulated transforming growth factor-b (TGFb) or RUNX2 function compromises the distinctly hard cochlear bone matrix and causes hearing loss in CCD.[15] Management for the patient with CCD is quite challenging. The earlier the treatment is initiated, the better is the prognosis.[16] "
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