Send to

Choose Destination
See comment in PubMed Commons below
Calcif Tissue Int. 2011 Jul;89(1):1-9. doi: 10.1007/s00223-011-9486-0. Epub 2011 May 2.

Early growth response gene 1 regulates bone properties in mice.

Author information

Bone Cell Biology and Imaging Laboratory, Caspary Research Building, Rm. 623, Hospital for Special Surgery, New York, NY 10021, USA.


Transcriptional regulation of the postnatal skeleton is incompletely understood. Here, we determined the consequence of loss of early growth response gene 1 (EGR-1) on bone properties. Analyses were performed on both the microscopic and molecular levels utilizing micro-computed tomography (micro-CT) and Fourier transform infrared imaging (FTIRI), respectively. Mice deficient in EGR-1 (Egr-1 (-/-)) were studied and compared to sex- and age-matched wild-type (wt) control animals. Femoral trabecular bone in male Egr-1 (-/-) mice demonstrated osteopenic characteristics marked by reductions in both bone volume fraction (BV/TV) and bone mineral density (BMD). Morphological analysis revealed fewer trabeculae in these animals. In contrast, female Egr-1 (-/-) animals had thinner trabeculae, but BV/TV and BMD were not significantly reduced. Analysis of femoral cortical bone at the mid-diaphysis did not show significant osteopenic characteristics but detected changes in cross-sectional geometry in both male and female Egr-1 (-/-) animals. Functionally, this resulted in decreased resistance to three-point bending as indicated by a reduction in maximum load, failure load, and stiffness. Assessment of compositional bone properties, including mineral-to-matrix ratio, carbonate-to-phosphate ratio, crystallinity, and cross-linking, in femurs by FTIRI did not show any significant differences or an appreciable trend between Egr-1 (-/-) and wt mice of either sex. Unexpectedly, rib bone from Egr-1 (-/-) animals displayed distinct osteopenic traits that were particularly pronounced in female mice. This study provides genetic evidence that both sex and skeletal site are critical determinants of EGR-1 activity in vivo and that its site-specific action may contribute to the mechanical properties of bone.

[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Springer
    Loading ...
    Support Center