CSF-1 Gene Expression in Osteoclast Biology

破骨细胞生物学中的 CSF-1 基因表达

• 批准号: 8631392
• 负责人: SHERRY L ABBOUD-WERNER
• 金额: $ 30.65万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-30 至 2018-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8631392
• 关键词: Age; Aging; Albers-Schonberg disease; Apoptosis; Biology; Bone Diseases; Bone remodeling; Breeding; Cell surface; Connexin 43; Connexins; Data; Defect; Dominant-Negative Mutation; Enzyme-Linked Immunosorbent Assay; Fracture; Gap Junctions; Gene Expression; Gene Expression Profile; Genes; Genetic; Goals; Health; Histology; Homeostasis; In Situ Hybridization; Knock-out; Lead; Longevity; Macrophage Colony-Stimulating Factor; Mechanics; Mitochondria; Modeling; Morbidity - disease rate; Mus; NADPH Oxidase; Osteoblasts; Osteoclasts; Osteocytes; Osteogenesis; Oxidases; Oxidation-Reduction; Oxidative Stress; Pathway interactions; Pattern; Phenotype; Protein Isoforms; Relative (related person); Reverse Transcriptase Polymerase Chain Reaction; Role; Signal Transduction; Small Interfering RNA; TNFSF11 gene; Testing; Therapeutic; Transgenic Organisms; Work; activity marker; age related; bone; bone loss; bone mass; bone strength; bone turnover; human FRAP1 protein; improved; insight; interest; laser capture microdissection; new therapeutic target; novel; novel therapeutics; overexpression; oxidant stress; prevent; public health relevance; receptor; skeletal; therapeutic target

ABSTRACT Bone loss and fracture are leading causes of morbidity with aging. The mechanisms of age-related bone disease have not been defined. Our studies suggest that CSF-1 deficiency and increased Nox4 oxidase expression in osteocytes are key determinants of oxidant stress that impact osteocyte survival/function that is essential for bone remodeling. The long-term goal of this proposal is to delineate mechanistic pathways by which CSF-1/oxidative stress regulate osteocyte homeostasis and identify therapeutic targets to prevent bone loss with age. CSF-1 and CSF-1R are expressed by osteocytes. The mechanisms by which CSF-1 or its isoforms, soluble (s) and cell-surface (cs) CSF-1, regulate osteocyte survival/function have not been explored. Oxidative stress contributes to osteocyte demise and bone loss with aging. Our findings indicate that, with aging, CSF-1 expression declines in osteocytes. We generated mice with global CSF-1 deficiency (CSF-1KO) that show osteopetrosis with increased fractures and osteocyte defects including apoptosis, associated with increased NADPH oxidase Nox4 expression/activity and reduced Cx43 expression. CSF-1 decreases NADPH oxidase activity in cultured osteocytes and CSF-1KO bone osteocytes show elevated Nox4 and activation of the mTOR pathway compared to WT osteocytes, suggesting that CSF-1 protects from oxidant stress. DMP1Cre-CSF-1cKO mice with conditional knockout (cKO) of CSF-1 in osteocytes/late osteoblasts also show increased Nox4, osteocyte defects, reduced osteoclasts and bone formation, predisposing to bone loss and fracture with age. We hypothesize that: a) osteocyte cKO of CSF-1 increases Nox4 and oxidative stress, impairs osteocytes and accelerates bone defects with age, b) deletion of Nox4 in CSF-1cKO osteocytes decreases oxidative stress, restores osteocyte function/bone remodeling with age, c) expression of sCSF-1 in CSF-1cKO osteocytes promotes osteocyte survival and proper bone remodeling to a greater extent than csCSF-1 during aging. We will test these hypotheses in the following specific aims: 1) Determine the effect of CSF-1cKO in osteocytes on bone phenotype and redox state during aging. WT and CSF-1cKO mice will be examined for bone phenotype and osteocytes will be assessed for apoptosis, Nox4 and gene expression profile; 2) Determine the role of Nox4 in osteocytes of CSF-1cKO mice and mechanisms by which CSF-1 regulates osteocyte survival. To dissect the interplay between CSF-1 and Nox4, mice with cKO of CSF-1 and Nox4 in osteocytes will be generated and signaling mechanisms by which CSF-1 regulates osteocyte survival will be analyzed in cultured osteocytes; 3) Determine the ability of CSF-1 isoforms to rescue bone defects in CSF-1cKO mice. This will be accomplished using a transgenic approach to target sCSF-1 or csCSF-1 in osteocytes of CSF-1cKO mice. These studies will provide new mechanistic insights by which CSF-1 controls osteocyte survival/function and may lead to novel therapeutic strategies for improving osteocyte viability crucial for bone strength and longevity.

抽象的 骨质流失和断裂是导致衰老发病率的主要原因。与年龄有关的骨骼的机制 疾病尚未定义。我们的研究表明CSF-1缺乏症和NOX4氧化酶增加 骨细胞中的表达是影响骨细胞存活/功能的氧化应激的关键决定因素 对于骨骼重塑至关重要。该提议的长期目标是描述机械途径 CSF-1/氧化应激调节骨细胞稳态并确定治疗靶标以防止 随着年龄的增长而流失。 CSF-1和CSF-1R由骨细胞表达。 CSF-1或 它的同工型，可溶性（S）和细胞表面（CS）CSF-1，调节骨细胞的生存/功能尚未是 探索。氧化应激有助于随着衰老而造成骨细胞的灭亡和骨质流失。我们的发现表明 随着衰老，CSF-1表达在骨细胞中下降。我们用全球CSF-1缺乏产生了小鼠 （CSF-1KO）表现出骨质肌畸形，骨折和骨细胞缺陷增加，包括细胞凋亡， 与NADPH氧化酶NOX4表达/活性增加和CX43表达降低有关。 CSF-1 降低培养的骨细胞和CSF-1KO骨骨细胞中NADPH氧化酶活性的升高 与WT骨细胞相比，NOX4和MTOR途径的激活，表明CSF-1保护 来自氧化应激。 DMP1CRE-CSF-1CKO小鼠，有条件敲除（CKO）的CSF-1在骨细胞/迟到 成骨细胞还显示NOX4增加，骨细胞缺陷，破骨细胞和骨形成减少， 随着年龄的增长而容易骨髓流失和骨折。我们假设：a）CSF-1的骨细胞CKO增加 NOX4和氧化应激，会损害骨细胞，并随着年龄的增长而加速骨骼缺陷，b）缺失Nox4 CSF-1CKO骨细胞减少氧化应激，随着年龄的增长恢复骨细胞功能/骨骼重塑，C） SCSF-1在CSF-1CKO骨细胞中的表达可促进骨细胞的存活和正确的骨头重塑 在衰老过程中，比CSCSF-1更大程度。我们将在以下特定目的中检验这些假设：1） 确定CSF-1CKO在骨细胞中对衰老过程中骨表型和氧化还原态的影响。 wt和 将检查CSF-1CKO小鼠的骨骼表型，将评估骨细胞的凋亡，NOX4 和基因表达谱； 2）确定NOX4在CSF-1CKO小鼠的骨细胞中的作用 CSF-1调节骨细胞存活的机制。剖析CSF-1和CSF-1之间的相互作用 NOX4，将CSF-1和NOX4的CKO小鼠在骨细胞中产生，并通过信号传导机制。 CSF-1调节骨细胞存活率将在培养的骨细胞中进行分析； 3）确定 CSF-1同工型可挽救CSF-1CKO小鼠的骨缺损。这将使用转基因完成 在CSF-1CKO小鼠的骨细胞中靶向SCSF-1或CSCSF-1的方法。这些研究将提供新的 CSF-1控制骨细胞存活/功能并可能导致新型治疗的机械见解 改善骨细胞生存能力的策略对于骨骼强度和寿命至关重要。