Hyperglycemia compromises Rat Cortical Bone by Increasing Osteocyte Lacunar Density and Decreasing Vascular Canal Volume

Birol Ay; Kushagra Parolia; Robert S Liddell; Yusheng Qiu; Giovanni Grasselli; David M L Cooper; John E Davies

doi:10.1038/s42003-019-0747-1

Hyperglycemia compromises Rat Cortical Bone by Increasing Osteocyte Lacunar Density and Decreasing Vascular Canal Volume

Commun Biol. 2020 Jan 9;3(1):20. doi: 10.1038/s42003-019-0747-1.

Authors

Birol Ay¹, Kushagra Parolia², Robert S Liddell³, Yusheng Qiu⁴, Giovanni Grasselli⁴, David M L Cooper², John E Davies^{5

6}

Affiliations

¹ Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada.
² Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK, Canada.
³ Faculty of Dentistry, University of Toronto, Toronto, ON, Canada.
⁴ Department of Civil Engineering, University of Toronto, Toronto, ON, Canada.
⁵ Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada. jed.davies@utoronto.ca.
⁶ Faculty of Dentistry, University of Toronto, Toronto, ON, Canada. jed.davies@utoronto.ca.

Abstract

Uncontrolled diabetes is associated with increased risk of bony fractures. However, the mechanisms have yet to be understood. Using high-resolution synchrotron micro-CT, we calculated the changes in the microstructure of femoral cortices of streptozotocin-induced hyperglycemic (STZ) Wistar Albino rats and tested the mechanical properties of the mineralized matrix by nanoindentation. Total lacunar volume of femoral cortices increased in STZ group due to a 9% increase in lacunar density. However, total vascular canal volume decreased in STZ group due to a remarkable decrease in vascular canal diameter (7 ± 0.3 vs. 8.5 ± 0.4 µm). Osteocytic territorial matrix volume was less in the STZ group (14,908 ± 689 µm³) compared with healthy controls (16,367 ± 391 µm³). In conclusion, hyperglycemia increased cellularity and lacunar density, decreased osteocyte territorial matrix, and reduced vascular girth, in addition to decreasing matrix mechanical properties in the STZ group when compared with euglycemic controls.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Bone Density*
Cortical Bone / blood supply*
Cortical Bone / diagnostic imaging
Cortical Bone / metabolism*
Cortical Bone / pathology*
Diabetes Mellitus, Experimental
Hyperglycemia / metabolism*
Hyperglycemia / pathology*
Imaging, Three-Dimensional
Immunohistochemistry
Male
Osteocytes / metabolism*
Rats
X-Ray Microtomography

Grants and funding

CIHR/Canada