1. Lacunar-canalicular network in femoral cortical bone is reduced in aged women and is predominantly due to a loss of canalicular porosity
- Author
-
C.D.L. Thomas, Peter Pivonka, Amir M. Ashique, Darrell D. Mousseau, L. S. Hart, David M. L. Cooper, Yasmin Carter, and John G. Clement
- Subjects
0301 basic medicine ,Pathology ,medicine.medical_specialty ,lcsh:Diseases of the musculoskeletal system ,Bone disease ,Endocrinology, Diabetes and Metabolism ,medicine.medical_treatment ,Canaliculi ,030209 endocrinology & metabolism ,Bone canaliculus ,Article ,Bone modeling ,03 medical and health sciences ,0302 clinical medicine ,Cortex (anatomy) ,medicine ,Confocal laser scanning microscopy ,Orthopedics and Sports Medicine ,Lacunae ,10. No inequality ,Bone ,Reduction (orthopedic surgery) ,Human aging ,Chemistry ,medicine.disease ,030104 developmental biology ,medicine.anatomical_structure ,Osteocyte ,Cortical bone ,lcsh:RC925-935 - Abstract
The lacunar-canalicular network (LCN) of bone contains osteocytes and their dendritic extensions, which allow for intercellular communication, and are believed to serve as the mechanosensors that coordinate the processes of bone modeling and remodeling. Imbalances in remodeling, for example, are linked to bone disease, including fragility associated with aging. We have reported that there is a reduction in scale for one component of the LCN, osteocyte lacunar volume, across the human lifespan in females. In the present study, we explore the hypothesis that canalicular porosity also declines with age. To visualize the LCN and to determine how its components are altered with aging, we examined samples from young (age: 20–23 y; n = 5) and aged (age: 70–86 y; n = 6) healthy women donors utilizing a fluorescent labelling technique in combination with confocal laser scanning microscopy. A large cross-sectional area of cortical bone spanning the endosteal to periosteal surfaces from the anterior proximal femoral shaft was examined in order to account for potential trans-cortical variation in the LCN. Overall, we found that LCN areal fraction was reduced by 40.6% in the samples from aged women. This reduction was due, in part, to a reduction in lacunar density (21.4% decline in lacunae number per given area of bone), but much more so due to a 44.6% decline in canalicular areal fraction. While the areal fraction of larger vascular canals was higher in endosteal vs. periosteal regions for both age groups, no regional differences were observed in the areal fractions of the LCN and its components for either age group. Our data indicate that the LCN is diminished in aged women, and is largely due to a decline in the canalicular areal fraction, and that, unlike vascular canal porosity, this diminished LCN is uniform across the cortex., Highlights • The lacunar-canalicular network (LCN) is reduced by 40.6% in aged women • The lacunar density (lacunae number per given area of bone) is reduced by 21.4% in aged women • The reduction in LCN in aged women is primarily due to a 44.6% loss of canaliculi • No endosteal vs. periosteal regional differences were observed in the LCN and its components in either young or aged women • A reduction in canaliculi with age may contribute to bone fragility in aged women
- Published
- 2017