Cell Adhesion Regulation of Osteoclast Maturation

破骨细胞成熟的细胞粘附调节

• 批准号: 9242582
• 负责人: YONGWON CHOI
• 金额: $ 35.2万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-01 至 2021-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9242582
• 关键词: Actins; Address; Adhesions; Adverse effects; Biological Assay; Biological Process; Biology; Bone Marrow Cells; Bone Resorption; Cell Adhesion; Cell Adhesion Molecules; Cell Count; Cell fusion; Cells; Clinical; Clinical Trials; Coupled; Data; Development; Differentiation Antigens; Disease; Eligibility Determination; Employment; Extracellular Domain; Gene Expression; Generations; Genes; Genetic; Homeostasis; Homo; Immunoglobulins; In Vitro; Inflammatory; Intervention; Label; Link; Measures; Mediating; Membrane Proteins; Molecular; Mus; Mutation Analysis; Osteoblasts; Osteoclasts; Osteogenesis; Osteoporosis; Ovariectomy; Pathogenicity; Pathologic; Pathway interactions; Periodontal Diseases; Phase; Physiological; Physiological Processes; Play; Prevention; Process; Proteins; Protocols documentation; Regulation; Reporting; Resolution; Rheumatoid Arthritis; Role; Signal Transduction; Signal Transduction Pathway; Specificity; Staining method; Stains; TNFSF11 gene; Testing; Therapeutic; Vesicle; Work; X-Ray Computed Tomography; bisphosphonate; bone; bone loss; bone strength; cathepsin K; cell motility; design; experimental study; gene function; improved; in vivo; member; mouse model; mutant; precursor cell; programs; protein function; public health relevance; therapeutic target; trafficking; treatment strategy

 DESCRIPTION (provided by applicant): Bone homeostasis is maintained by the balanced functions of bone-forming osteoblasts (OBs) and bone- resorbing osteoclasts (OCs). Excessive OC activity can cause pathogenic bone loss, so it is important to understand the molecular signaling and genetic programs controlling the commitment, maturation, and resorption phases of OC development. Current bone loss treatments target early OC commitment and/or later viability. Long-term use of these treatments may cause compromised bone strength, possibly due to inhibition of coupled bone formation, which requires positive interplay between OCs and OBs. A better treatment strategy may be to target late-stage OC biology in favor of early OC differentiation, and in fact some recent clinical trials have successfully employed targeted inhibition of resorption without observed diminution of either OC numbers or coupled bone formation. Therefore, better understanding the regulatory factors and mechanisms of OC maturation may be extremely useful for providing better therapeutic targets. In particular, a growing number of cell adhesion molecules are now implicated in bone homeostasis and they are good potential targets for clinical intervention. Therefore, we designed a screening protocol -- described in this proposal -- to identify genes dually associated with OC maturation and cell adhesion. We now identify IgSF11, which has no previously reported function in bone, as being required specifically for progression from the commitment to the mature stages of osteoclast differentiation. We have generated and employed IGSF11-/- mice to preliminarily show that IGSF11-/- OC maturation in vitro is defective, demonstrating a potential genetic link to further pursue OC maturation-related therapeutic strategies. We therefore propose the following specific aims: 1. Investigate the effect of IgSF11 deficiency on osteoclast development and function. To begin to define the requirement for IGSF11 in OC biology per se, we will first assess early IGSF11-/- OC commitment ex vivo, and then interrogate IGSF11-/- OC maturation through gene expression and cell biologic approaches ex vivo. To examine the effects of IGSF11 deficiency on bone homeostasis, OC function and maturation in vivo, we will subject IGSF11-/- bones and bone sections obtained under normal, OVX, PTH-treated, or inflammatory conditions to high-resolution micro-computed tomography and histomorphometry, as well as TRAP staining. 2. Determine mechanisms of IgSF11 function in the context of osteoclast biology. We will determine whether IgSF11 is required for adhesion between cells during OC maturation by mixing IgSF11-expressing and IgSF11- deficient OC cultures. The effects of OC IgSF11 deficiency on expression and function of known OC- associated cell adhesion factors will be assayed. Via mutational analysis, regulation of homo- and hetero-typic interactions and cell signaling by specific IgSF11 domains retrovirally expressed in OCs will be analyzed. These experiments will address not only whether IgSF11 is required for OC cell adhesion, but also the specificity of IgSF11-mediated adhesion and potential signaling mechanisms in the context of OC maturation.

 描述（由申请人提供）：骨稳态由骨形成成骨细胞（OB）和骨吸收破骨细胞（OC）的平衡功能维持。过度的OC活性可导致致病性骨丢失，因此了解控制OC发育的定型、成熟和再吸收阶段的分子信号传导和遗传程序非常重要。目前的骨丢失治疗目标是早期OC承诺和/或后期生存能力。长期使用这些治疗可能会导致骨强度受损，这可能是由于偶联骨形成的抑制，这需要OC和OB之间的积极相互作用。更好的治疗策略可能是靶向晚期OC生物学，有利于早期OC分化，事实上，最近的一些临床试验已经成功地采用了靶向抑制再吸收，而没有观察到OC数量或偶联骨的减少。阵因此，更好地了解OC成熟的调控因素和机制可能对提供更好的治疗靶点非常有用。特别是，越来越多的细胞粘附分子参与骨稳态，它们是临床干预的良好潜在靶点。因此，我们设计了一个筛选方案-在这个建议中描述-以确定与OC成熟和细胞粘附双重相关的基因。我们现在确定IgSF 11，这是以前没有报道的功能，在骨，作为特定的进展所需的承诺，破骨细胞分化的成熟阶段。我们已经产生并使用IGSF 11-/-小鼠，初步表明IGSF 11-/- OC体外成熟是有缺陷的，这表明了进一步追求OC成熟相关治疗策略的潜在遗传联系。因此，我们提出以下具体目标：1.研究IgSF 11缺乏对破骨细胞发育和功能的影响。为了开始定义OC生物学本身对IGSF 11的要求，我们将首先离体评估早期IGSF 11-/- OC定型，然后通过基因表达和细胞生物学方法离体询问IGSF 11-/- OC成熟。为了研究IGSF 11缺乏对体内骨稳态、OC功能和成熟的影响，我们将对在正常、OVX、PTH治疗或炎症条件下获得的IGSF 11-/-骨和骨切片进行高分辨率显微计算机断层扫描和组织形态测定，以及TRAP染色。2.确定破骨细胞生物学背景下IgSF 11功能的机制。我们将通过混合表达IgSF 11和IgSF 11缺陷的OC培养物来确定OC成熟过程中细胞间粘附是否需要IgSF 11。将测定OC IgSF 11缺乏对已知OC相关细胞粘附因子的表达和功能的影响。通过突变分析，将分析OC中逆转录病毒表达的特异性IgSF 11结构域对同型和异型相互作用和细胞信号传导的调节。这些实验将不仅解决IgSF 11是否是OC细胞粘附所需的，而且还解决IgSF 11介导的粘附的特异性和OC成熟背景下的潜在信号传导机制。