Mechanobiology of 3D Trabecular Bone Explants

3D 小梁骨外植体的力学生物学

• 批准号: 7808303
• 负责人: X. Edward GUO
• 金额: $ 32.38万
• 依托单位: COLUMBIA UNIV NEW YORK MORNINGSIDE
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-30 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7808303
• 关键词: Affect; Applications Grants; Biochemical; Biochemical Pathway; Bone Matrix; Ca(2+)-Calmodulin Dependent Protein Kinase; Calcium; Cattle; Cells; Cilia; Clinical; Coculture Techniques; Connexin 43; Dinoprostone; Elements; Environment; Etiology; Extracellular Matrix; Gap Junctions; Hand; In Vitro; Knockout Mice; Knowledge; Lead; Life; Link; Liquid substance; Mature Bone; Mechanics; MicroRNAs; Modeling; Molecular; Molecular Biology Techniques; Morphology; Nitrites; Osteoblasts; Osteocytes; Osteogenesis; Osteoporosis; Oxides; PTGS2 gene; Pathway interactions; Pharmacologic Substance; Positioning Attribute; Process; Production; Relative (related person); Research; Resistance; Role; Signal Transduction; Skeleton; Specimen; Stimulus; Study Subject; Study models; System; Tail Suspension; Technology; Testing; Therapeutic; Therapeutic Intervention; Tissues; Transgenic Mice; Work; bone; bone cell; bone loss; extracellular; in vivo; inhibitor/antagonist; insight; intercellular connection; kinase inhibitor; novel; novel therapeutics; public health relevance; receptor; response; sensor; substantia spongiosa

DESCRIPTION (provided by applicant): Osteocytes (OCY) are intrinsically three-dimensional (3D), mature bone cells encased in 3D mineralized extracellular bone matrix. Recent studies indicate the critical roles of osteocytes in detecting mechanical signals and maintaining skeleton integrity. These roles have significant clinical implications, such as in the etiology of osteoporosis or new pharmaceutical targets for osteoporosis treatment. A novel 3D trabecular bone explant co-culture model for osteocyte-osteoblast mechanobiology in this proposal allows for live osteocytes to be surrounded by their native extracellular matrix environment and to interconnect with osteoblasts (OB) through intercellular processes in the canaliculi channels. We propose to use this novel 3D trabecular bone co-culture model to test a central scientific hypothesis that that dynamic deformational loading induces OCYs to send anabolic signals to OBs to promote bone formation through intraceluar calcium [Ca2+]i oscillations in osteocytic network, followed by prostaglandin E2 (PGE2) production/secretion via gap junctions/hemi-channels to OBs. We will test the following working hypotheses: Hypothesis H1: PGE2 production, changes in bone formation, and elastic modulus of 3D bovine trabecular bone explants with seeded primary bovine OBs depend on calmodulin kinase (CaMK) dependent Ca2+ oscillations in OCYs. Hypothesis H2: PGE2 production, changes in bone formation, and elastic modulus of 3D bovine trabecular bone explants with seeded primary bovine OBs depend on the gap junctions/hemi-channels connexin 43 (Cx43) in OCYs. Hypothesis H3: Bone formation response of OBs seeded in 3D trabecular bone explants under dynamic deformational loading and changes in elastic modulus of trabecular bone depend on PGE2 pathway. With this new co-culture system of trabecular bone explants, the interaction between osteocytes and osteoblasts under mechanical loading can be investigated in vitro under conditions that are more physiologically relevant than previously possible: (1) both osteocytes and osteoblasts are included and positioned in their native 3D trabecular bone environment when subjected to dynamic deformational loading; (2) functional bone formation and elastic modulus of trabecular bone will be assessed in vitro, linking important factors in osteocyte-osteoblast mechanotransduction to bone functions; (3) selectively manipulating biochemical pathways in OCYs and OBs independently with sophisticated molecular biology technique, which cannot be achieved in vivo, and (4) micromechanical environments surrounding osteocytes and/or osteoblasts will be quantified, respectively, using specimen specific finite element models. New insights will be gained regarding cellular and molecular mechanisms of bone cell mechanotransduction and will contribute to our general understanding of the etiology of osteoporosis, and may lead to therapeutic interventions aimed at the mitigation or treatment of osteoporosis. PUBLIC HEALTH RELEVANCE: The novel three-dimensional (3D) live trabecular bone explant co-culture model will be used to quantify important biochemical pathways between osteocytes and osteoblasts under dynamic deformational loading. The understanding of cellular and molecular mechanotransduction pathways between osteocytes and osteoblasts contributes to our general understanding of the etiology of osteoporosis and can lead to new therapeutic treatment of osteoporosis.

描述（由申请人提供）：骨细胞（OCY）本质上是三维（3D），成熟的骨细胞包裹在3D矿化的细胞外骨基质中。最近的研究表明，骨细胞在检测机械信号和保持骨骼完整性中的关键作用。这些作用具有显着的临床意义，例如在骨质疏松症的病因或骨质疏松治疗的新药物靶标。该提案中的新型3D小梁骨外植体共培养模型，用于骨细胞 - 骨细胞机械生物学模型，可以使活的骨细胞被其天然细胞外基质环境所包围，并通过canaliculi Channels中的细胞间过程与成骨细胞（OB）相互连接。我们建议使用这种新型的3D小梁骨共培养模型来检验一种中心的科学假设，即动态变形载荷引起OCYS诱导OCYS发送代谢信号以通过钙内钙[Ca2+] I振荡促进骨形成[Ca2+] I振荡，然后在骨网e2/pge 2（PGE 2）中进行Obs-pge/hemem gap/gap to Ibs gap capions/gap。我们将测试以下工作假设：假设H1：PGE2的产生，骨形成的变化以及3D牛的小梁骨外植体的弹性模量，带有种子的原代牛OBS依赖于OCYS中的钙调蛋白激酶（CAMK）依赖CAC2+振荡。假设H2：PGE2的产生，骨形成的变化以及带有种子原代牛的3D小梁骨外植体的弹性模量取决于OCYS中的间隙连接/半通道连接蛋白43（CX43）。假设H3：在动态变形载荷下，在3D小梁骨外植体中观察到的骨形成反应以及小梁骨弹性模量的变化取决于PGE2途径。通过这种新的小梁骨外植体的共同培养系统，可以在体外在体外研究在生理上相关的机械负荷下的成骨细胞和成骨细胞之间的相互作用，而在生理上比以前可能更相关的情况：（1）在其本地3D Trabecular Emport中包括了成骨细胞和成骨细胞和成骨细胞，并将其定位在其原始的3D Trabecular Emopitive中。 （2）将在体外评估小梁骨的功能性骨形成和弹性模量，将成骨细胞 - 骨细胞机械转导的重要因素与骨功能联系起来； （3）选择性操纵OCYS中的生化途径，并与无法在体内实现的复杂分子生物学技术独立观察，并且（4）使用标本特定的有限限元模型来量化成骨细胞和/或成骨细胞周围的微型机械环境。关于骨细胞机械转导的细胞和分子机制将获得新的见解，并将有助于我们对骨质疏松症的病因的一般理解，并可能导致旨在缓解或治疗骨质疏松症的治疗干预措施。 公共卫生相关性：新型的三维（3D）活小梁外植体共培养模型将用于量化在动态变形负载下成骨细胞和成骨细胞之间重要的生化途径。对骨细胞和成骨细胞之间的细胞和分子机械转导途径的理解有助于我们对骨质疏松病的病因的一般理解，并可能导致对骨质疏松症的新治疗治疗。