title: The dependences of osteocyte network on bone compartment, age, and disease.
abstract: Osteocytes, the most abundant bone cells, form an interconnected network in the lacunar-canalicular pore system (LCS) buried within the mineralized matrix, which allows osteocytes to obtain nutrients from the blood supply, sense external mechanical signals, and communicate among themselves and with other cells on bone surfaces. In this study, we examined key features of the LCS network including the topological parameter and the detailed structure of individual connections and their variations in cortical and cancellous compartments, at different ages, and in two disease conditions with altered mechanosensing (perlecan deficiency and diabetes). LCS network showed both topological stability, in terms of conservation of connectivity among osteocyte lacunae (similar to the "nodes" in a computer network), and considerable variability the pericellular annular fluid gap surrounding lacunae and canaliculi (similar to the "bandwidth" of individual links in a computer network). Age, in the range of our study (15-32 weeks), affected only the pericellular fluid annulus in cortical bone but not in cancellous bone. Diabetes impacted the spacing of the lacunae, while the perlecan deficiency had a profound influence on the pericellular fluid annulus. The LCS network features play important roles in osteocyte signaling and regulation of bone growth and adaptation.
authors.affiliation: Department of Mechanical Engineering, University of Delaware, Newark, DE, USA.
authors.forename: Xiaohan
authors.initials: X
authors.lastname: Lai
authors.affiliation: Biomedical Engineering Program, University of Delaware, Newark, DE, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Price
authors.affiliation: DBI Bioimaging Center, University of Delaware, Newark, DE, USA.
authors.forename: Shannon
authors.initials: S
authors.lastname: Modla
authors.affiliation: Department of Physical Therapy, Indiana University, Indianapolis, IN, USA.
authors.forename: William R
authors.initials: WR
authors.lastname: Thompson
authors.affiliation: DBI Bioimaging Center, University of Delaware, Newark, DE, USA.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Caplan
authors.affiliation: Department of Biological Sciences, University of Delaware, Newark, DE, USA.
authors.forename: Catherine B
authors.initials: CB
authors.lastname: Kirn-Safran
authors.affiliation: Department of Mechanical Engineering, University of Delaware, Newark, DE, USA.
authors.forename: Liyun
authors.initials: L
authors.lastname: Wang