Areal Distribution of Preferential Alignment of Biological Apatite (BAp) Crystallite on Cross-Section of Center of Femoral Diaphysis in Osteopetrotic (op/op) Mouse

Abstract

Osteoclasts are nearly non-existent in mutant osteopetrotic (op/op) mice due to defects in the expression of the macrophage colonystimulating factor (M-CSF). Thus, areal distribution of the biological apatite (BAp) c-axis in a femoral cross-section of an op/op mouse was investigated using a microbeam X-ray diffraction system to understand the role of osteoclasts on formation of BAp preferential alignment.The incident X-ray beam is focused to 20 mm in diameter. The diffraction analysis is performed at 20 mm displacement intervals from the periosteal surface along the radial axis of the anterior portion at a cross-section of the femoral diaphysis. The osteopetrotic (op/op) mouse and its normal littermate used as a control were 12 weeks old.The lack of osteoclasts induces both abnormality of the skeletal system and calcification of the medullary cavity, which are typical features of osteopetrosis. Preferential alignment of the BAp c-axis in the osteopetrotic (op/op) mouse always shows a lower degree than that in the control mouse, regardless of the distance from the periosteum. Moreover, areal distributions of preferential alignment of the BAp c-axis on the femoral cross-section show quite different tendencies between the op/op and control mice. The preferential alignment of BAp gradually increases towards the periosteal surface in the op/op mouse due to the intramembranous ossification, while that in the control mouse is the lowest near the cortical envelope on the cross-section. This is because the decrease in the number of osteoclasts suppresses the normal modeling or remodeling, resulting in degradation of preferential alignment of the BAp c-axis as a bone quality parameter in the op/op mouse.

Disruption of Collagen Matrix Alignment in Osteolytic Bone Metastasis Induced by Breast Cancer

“…15) Indeed, in some skeletal disorders that are accompanied by abnormalities in osteoclasts, the bone microstructure is susceptible to alteration. 16,17) In particular, irregularity of the geometry of osteoclast resorption cavities has been demonstrated in Paget s disease 17) and glucocorticoid-induced osteoporosis. 19) Since these skeletal disorders display an increased resorption activity which is attributable to alterations in osteoclast biology, 20,21) insights into the association of osteoclast biology, geometry of osteoclastic resorption cavities, and microstructure of newly formed bone should be helpful to understand the mechanisms responsible for the maintenance of bone quality in biological systems.…”

Analysis of Biological Apatite Crystal Orientation in Anterior Cortical Bone of Human Mandible Using Microbeam X-ray Diffractometry

“…Measurement conditions were the same as those used by Nakano et al 6,18,19) The transmission diffractometer produced diffraction rings on the imaging plate (IP) with diffraction lines. The extent of BAp crystal orientation was then evaluated by reading the IP with detection software (3DS, Rigaku Co., Tokyo, Japan) and calculating the intensity ratio of the two diffraction peaks, namely (002) and (310).…”

Structural Crosstalk between Crystallographic Anisotropy in Bone Tissue and Vascular Network Analyzed with a Novel Visualization Method

“…Bone matrix comprising collagen brils and biological apatite (BAp) crystals highly align along the bone longitudinal axis both in Haversian and non-Haversian lamellar structures in long bones, depending on stress distributions. [4][5][6]19) More importantly, the alignment of collagen/BAp is an essential factor that contributes to bone mechanical function, as observed by the signi cant correlation between the degree of the BAp c-axis alignment and bone Young s modulus. 6) Meanwhile, the association between the vascular patterns and bone microstructure is largely unknown, partially because of the technical dif culties associated with the vessels existing inside a highly mineralized matrix.…”

“…The blood supply also helps bone cells to reach the appropriate site for bone modeling/remodeling; it transports osteoclast precursors to the bone surface where remodeling should occur and recruits circulating osteoblast precursor cells to the bone remodeling compartment. 2,3) Because the mechanical and biological functions of bone tissue are governed by its anisotropic microstructure, [4][5][6] it is essential to understand the structural relationship between bone tissue orientation and intraosseous vascularization.…”