Regulator of Calcineurin (RCAN1)-a Novel Regulator of Osteoclastogenesis

钙调神经磷酸酶调节因子 (RCAN1)——一种新型破骨细胞生成调节因子

• 批准号: 8734212
• 负责人: KEVIN P MCHUGH
• 金额: $ 46.41万
• 依托单位: UNIVERSITY OF FLORIDA
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-06 至 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8734212
• 关键词: Address; Adoptive Transfer; Animals; Binding; Biology; Bone Marrow Cells; Bone Matrix; Bone Surface; Calcineurin; Cell Culture Techniques; Cell Lineage; Cells; Data; Defect; Deletion Mutation; Dominant-Negative Mutation; Down Syndrome; Eating; Estrogens; Exhibits; Family; Gene Expression; Generations; Genes; Genetic Programming; Genetic Transcription; Hematopoietic; Implant; In Vitro; Individual; Interleukin-1; Knockout Mice; Ligands; Literature; Luciferases; MAP3K7 gene; Macrophage Colony-Stimulating Factor; Mediating; Messenger RNA; Molecular; Molecular Profiling; Mus; Myelogenous; Nuclear Translocation; Nucleic Acid Regulatory Sequences; Orthopedics; Osteoclasts; Osteoporosis; Ovariectomy; Pathologic; Pathway interactions; Patients; Phenotype; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotransferases; Plastics; Play; Proteins; Publishing; Regulation; Regulator Genes; Reporter; Resistance; Rheumatoid Arthritis; Role; Signal Pathway; Signal Transduction; Structure; TNF gene; TNFSF11 gene; Testing; Transcription Factor AP-1; Transcriptional Regulation; Transfection; Translating; Ubiquitination; Validation; base; bone; bone loss; c-fms Proto-Oncogenes; effective therapy; in vivo; inhibitor/antagonist; insight; member; mouse model; multicatalytic endopeptidase complex; mutant; novel; osteoclastogenesis; physiologic bone resorption; prevent; promoter; public health relevance; receptor; research study; response; skeletal; skeletal disorder; small molecule; substantia spongiosa; tissue culture; transcription factor

DESCRIPTION (provided by applicant): Osteoclasts (OCs), which are essential for physiologic bone resorption, are derived from hematopoietic precursors in response to M-CSF and RANKL. In vitro experiments examining gene expression profiles of OC precursors exposed to RANKL and M-CSF led to identification of NFATc1 as a key regulator of OC formation and function. These experiments were performed with cells cultured on tissue culture plastic, whereas OCs develop in vivo in the context of a bone substrate. We compared the gene expression profiles of OCs cultured on bone with those obtained from the same cells on plastic and have identified multiple genes that are strongly and uniquely induced in OCs generated on bone. To identify the molecular mechanisms and signal pathways that mediate terminal OC differentiation and activation, we focused on regulator of calcineurin 1 (RCAN1), which is a prototypical member of the bone-regulated OC genes and is the best characterized and most highly expressed member of the RCAN family. RCAN1 controls the activity of calcineurin, which in turn regulates the activation of NFATc1, which plays a pivotal role in the transcriptional regulation of multiple OC-associated genes. Our analysis of the regulatory regions of the RCAN1 gene indicates several potential transcriptional and posttranscriptional regulatory mechanisms that may mediate bone-specific RCAN1 expression. Mice lacking RCAN1 exhibit a bone phenotype, characterized by increased trabecular bone with reduced OC-mediated resorption. Moreover, RCAN1 enhances transcription of multiple OC genes, indicating that RCAN1 plays an important role in controlling the genetic program and signal pathways of OC differentiation and activation. Based on these data we hypothesize that: RCAN1 expression and activity are up-regulated by interaction of OCs with bone and that RCAN1 plays a central role in regulating OC formation and activation by modulating the calcineurin-NFATc1 pathway. To pursue our novel findings, we propose the following specific aims: Aim 1 Identify the signaling pathways by which RCAN1 is activated during RANKL-induced OC formation on bone surfaces. Aim 2 Define the individual domains of RCAN1 that contribute to its role in OC biology. We will also test the hypothesis that the absence of RCAN1 will render animals resistant to the bone loss associated with estrogen deficiency in a mouse model of osteoporosis. Aim 3 will dissect the transcriptional and post-transcriptional mechanisms by which RANKL and bone substrate regulate expression of RCAN1. There remains an unmet need for more effective therapies to reduce bone loss and prevent potentially debilitating complications in patients with skeletal disorders. The proposed experiments utilizing OCs differentiated on bone will provide new directions and opportunities for developing more effective and specific therapies to prevent OC-mediated bone loss in osteoporosis and related forms of pathologic bone loss.

描述（由申请人提供）：破骨细胞（OCs）是生理性骨吸收所必需的，来源于造血前体，响应M-CSF和RANKL。通过体外实验检测暴露于RANKL和M-CSF的OC前体的基因表达谱，鉴定出NFATc1是OC形成和功能的关键调节因子。这些实验是用在组织培养塑料上培养的细胞进行的，而OCs是在骨基质的环境下在体内发育的。我们比较了在骨上培养的OCs与在塑料上从相同细胞获得的OCs的基因表达谱，并确定了在骨上产生的OCs中强烈且独特地诱导的多个基因。为了确定介导OC末端分化和激活的分子机制和信号通路，我们重点研究了钙调神经磷酸酶1 （calcineurin 1, RCAN1）的调节因子，它是骨调节OC基因的一个原型成员，也是RCAN家族中表征最好、表达最多的成员。RCAN1控制calcalineurin的活性，calcalineurin反过来调节NFATc1的激活，NFATc1在多种oc相关基因的转录调控中起关键作用。我们对RCAN1基因调控区域的分析表明，几种潜在的转录和转录后调控机制可能介导骨特异性RCAN1的表达。缺乏RCAN1的小鼠表现出骨表型，其特征是骨小梁增加，oc介导的吸收减少。此外，RCAN1可增强多个OC基因的转录，表明RCAN1在OC分化和激活的遗传程序和信号通路中发挥重要作用。基于这些数据，我们假设：RCAN1的表达和活性通过OCs与骨的相互作用而上调，并且RCAN1通过调节钙调神经磷酸酶- nfatc1通路在调节OC的形成和激活中起核心作用。为了实现我们的新发现，我们提出了以下具体目标：目的1：确定在rankl诱导的骨表面OC形成过程中RCAN1被激活的信号通路。目的2：明确RCAN1在OC生物学中的作用。我们还将在骨质疏松小鼠模型中验证RCAN1缺失会使动物抵抗与雌激素缺乏相关的骨质流失的假设。目的3将剖析RANKL和骨底物调控RCAN1表达的转录和转录后机制。对于减少骨质流失和预防骨骼疾病患者潜在的衰弱并发症的更有效疗法的需求仍未得到满足。利用骨分化OCs的实验将为开发更有效和特异性的治疗方法来预防骨质疏松症oc介导的骨质流失和相关形式的病理性骨质流失提供新的方向和机会。