RRC ID 16025
著者 Kwon RY, Meays DR, Meilan AS, Jones J, Miramontes R, Kardos N, Yeh JC, Frangos JA.
タイトル Skeletal adaptation to intramedullary pressure-induced interstitial fluid flow is enhanced in mice subjected to targeted osteocyte ablation.
ジャーナル PLoS One
Abstract Interstitial fluid flow (IFF) is a potent regulatory signal in bone. During mechanical loading, IFF is generated through two distinct mechanisms that result in spatially distinct flow profiles: poroelastic interactions within the lacunar-canalicular system, and intramedullary pressurization. While the former generates IFF primarily within the lacunar-canalicular network, the latter generates significant flow at the endosteal surface as well as within the tissue. This gives rise to the intriguing possibility that loading-induced IFF may differentially activate osteocytes or surface-residing cells depending on the generating mechanism, and that sensation of IFF generated via intramedullary pressurization may be mediated by a non-osteocytic bone cell population. To begin to explore this possibility, we used the Dmp1-HBEGF inducible osteocyte ablation mouse model and a microfluidic system for modulating intramedullary pressure (ImP) to assess whether structural adaptation to ImP-driven IFF is altered by partial osteocyte depletion. Canalicular convective velocities during pressurization were estimated through the use of fluorescence recovery after photobleaching and computational modeling. Following osteocyte ablation, transgenic mice exhibited severe losses in bone structure and altered responses to hindlimb suspension in a compartment-specific manner. In pressure-loaded limbs, transgenic mice displayed similar or significantly enhanced structural adaptation to Imp-driven IFF, particularly in the trabecular compartment, despite up to ∼50% of trabecular lacunae being uninhabited following ablation. Interestingly, regression analysis revealed relative gains in bone structure in pressure-loaded limbs were correlated with reductions in bone structure in unpressurized control limbs, suggesting that adaptation to ImP-driven IFF was potentiated by increases in osteoclastic activity and/or reductions in osteoblastic activity incurred independently of pressure loading. Collectively, these studies indicate that structural adaptation to ImP-driven IFF can proceed unimpeded following a significant depletion in osteocytes, consistent with the potential existence of a non-osteocytic bone cell population that senses ImP-driven IFF independently and potentially parallel to osteocytic sensation of poroelasticity-derived IFF.
巻・号 7(3)
ページ e33336
公開日 2012-1-1
DOI 10.1371/journal.pone.0033336
PII PONE-D-11-21499
PMID 22413015
PMC PMC3296683
MeSH Ablation Techniques / instrumentation Ablation Techniques / methods* Adaptation, Physiological* Animals Bone Density Bone Resorption / etiology Bone and Bones / physiology* Bone and Bones / surgery* Extracellular Fluid / physiology* Female Hindlimb Suspension / adverse effects Mice Mice, Inbred C57BL Mice, Transgenic Osteocytes* Pressure
IF 2.74
引用数 23
WOS 分野 ENDOCRINOLOGY & METABOLISM
リソース情報
実験動物マウス RBRC02237