Function of Regulator of G protein signaling in aging skeleton

G蛋白信号调节因子在骨骼衰老中的作用

基本信息

批准号：
9294321
负责人：
SHUYING YANG
金额：
$ 36.79万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-08-01 至 2019-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9294321
关键词：
Adverse effects Affect Age Age-Related Bone Loss Age-Related Osteoporosis Aging Binding Biological Assay Bone Diseases Bone Resorption Bone remodeling Calcium Channel Calcium Signaling Calcium-Sensing Receptors Cell Lineage Data Disease Ectopic Expression Family Fc Receptor Fracture GTP-Binding Protein Regulators Goals Guanosine Triphosphate Phosphohydrolases Health Hematopoietic Heterodimerization Heterogeneity Immunoprecipitation In Vitro Knockout Mice Ligands Marrow Mass Spectrum Analysis Mediating Mesenchymal Molecular Mus Nuclear Osteoclasts Osteoporosis PTB Domain PTH gene Pathologic Pathway interactions Patients Phenotype Phosphorylation Phosphotyrosine Play Proteins Public Health RGS Domain RGS Proteins RGS1 gene Regulation Research Role Selective Estrogen Receptor Modulators Series Skeleton Specificity TNFSF11 gene Testing Therapeutic Intervention Woman aged base bisphosphonate bone bone mass bone metabolism cathepsin K insight knock-down lipid biosynthesis men mutant nuclear factors of activated T-cells osteoclastogenesis phospholipase C gamma postnatal receptor response skeletal therapeutic target

项目摘要

DESCRIPTION (provided by applicant): Age-associated osteoporosis is a major health problem, which is characterized by an imbalance in bone remodeling and metabolism due to the increase of osteoclastogenesis and activity with age. The current treatment options have been constrained with lower response rates or side-effects and ineffectively tackle the burden and heterogeneity of osteoporosis. Further progress in establishing successful treatment urgently requires a clearer understanding of the mechanisms of osteoclast (OC) differentiation and bone remodeling with age. Evidences have documented that RANKL -evoked Ca2+ oscillations play a switch-on role in the activation of PLC� and NFATc1, and OC differentiation. Further study showed that FcR� and DAP 12 regulate the phosphorylation of PLC�, which is the critical component involved in the RANKL-induced Ca2+ oscillations- NFATc1 pathway. Despite these new insights, it remains unclear how RANKL evokes the essential Ca2+ oscillations that triggers NFATc1 activation and OC differentiation, and it is unknown whether and how this mechanism is involved in age-associated bone loss. Our recent research demonstrated that Regulator of G protein signaling protein 12 (RGS12) was prominently expressed during OC differentiation and that RGS12 expression was significantly increased with increasing age. Knockdown of RGS12 expression inhibited Ca2+ oscillations, NFATc1 expression and OC differentiation. Deletion of RGS12 from hematopoietic/early OC lineage cells (RGS12 / /cre) led to a significantly increase of bone mass, and this increase of bone mass was protected from age-associated bone loss in RGS12 / /cre mice. We also found that loss of RGS12 in mice decreased OC number and levels of marrow adipogenesis with age. Based on these results, we hypothesize that age-associated bone remodeling and metabolism requires RGS12 expression and function, and RGS12 is a critical regulator in controlling Ca2+ oscillation and OC differentiation during aging. We will test the hypothesis through the following two specific aims. In Aim 1, we will reveal the function of RGS12 in OC differentiation and function during aging through characterization of the phenotypes and pathomechanism of RGS12 conditional knockout mice. We will analyze bone phenotypes in young (6 months (m)), mid-aged (14m) and aged (24m) mice to determine how deletion of RGS12 in early and late OC lineage cells affect postnatal age-associated bone metabolism by using Mx1-cre and Cathepsin K-Cre mice. We will further characterize in vitro of OCs derived from aging RGS12 / /cre mice and determine the contribution of mesenchymal lineage cells to the OCs and skeletal phenotype in aging RGS12 / /cre mice. In Aim 2, we will elucidate the mechanism of RGS12 interactions that confer specificity of Ca2+ oscillation and OCs with age by characterizing pathomechanism and pathways, RGS12 domain functions and its heterodimerization partners. The goal of this project is to discover the role and mechanism of RGS12 in OC differentiation and activation in pathologic age condition, and provide new and more effective therapeutic targets to age-associated osteoporosis and other bone diseases.

描述（由申请人提供）：与年龄相关的骨质疏松症是一个主要的健康问题，其特征是由于破骨细胞生成和活性随着年龄的增长而增加，导致骨重塑和代谢失衡。目前的治疗方案受到较低反应率的限制。或副作用，并且无法有效地解决骨质疏松症的负担和异质性，迫切需要更清楚地了解破骨细胞（OC）随年龄的分化和骨重塑机制。据报道，RANKL 诱发的 Ca2+ 振荡在 PLC� 和 NFATc1 的激活以及 OC 分化中发挥着开关作用。进一步的研究表明，FcR� 和 DAP 12 调节 PLC� 的磷酸化，这是参与 PLC� 的关键成分。 RANKL 诱导的 Ca2+ 振荡 - NFATc1 途径尽管有这些新见解，但仍不清楚 RANKL 如何激发必需的 Ca2+。触发 NFATc1 激活和 OC 分化的振荡，目前尚不清楚该机制是否以及如何参与与年龄相关的骨质流失。我们最近的研究表明，G 蛋白信号传导蛋白调节器 12 (RGS12) 在 OC 分化过程中显着表达。 RGS12 表达随着年龄的增加而显着增加。RGS12 表达的敲低抑制了 Ca2+ 振荡、NFATc1 表达和 OC 分化。来自造血/早期 OC 谱系细胞 (RGS12 / /cre) 的 RGS12 导致骨量显着增加，并且这种骨量的增加可以保护 RGS12 / /cre 小鼠免受年龄相关的骨质流失。随着年龄的增长，小鼠中的 RGS12 减少了 OC 数量和骨髓脂肪生成水平，基于这些结果，我们发现与年龄相关的骨重塑和代谢需要 RGS12 的表达和功能，并且RGS12 是衰老过程中控制 Ca2+ 振荡和 OC 分化的关键调节因子。我们将通过以下两个具体目标来检验这一假设：在目标 1 中，我们将通过表型表征来揭示 RGS12 在衰老过程中 OC 分化和功能中的功能。我们将分析年轻（6 个月（m））、中年（14m）和老年（24m）小鼠的骨表型，以确定如何进行研究。通过使用 Mx1-cre 和组织蛋白酶 K-Cre 小鼠，早期和晚期 OC 谱系细胞中 RGS12 的缺失会影响出生后年龄相关的骨代谢。我们将进一步表征来自衰老 RGS12 / /cre 小鼠的 OC 的体外特征，并确定其贡献。间充质谱系细胞对衰老 RGS12 / /cre 小鼠中 OC 和骨骼表型的影响在目标 2 中，我们将阐明 RGS12 的机制。通过表征病理机制和途径、RGS12 结构域功能及其异二聚化伙伴，研究 Ca2+ 振荡和 OC 与年龄的相互作用。该项目的目标是发现 RGS12 在病理年龄条件下 OC 分化和激活中的作用和机制，并赋予其相关性。为与年龄相关的骨质疏松症和其他骨病提供新的、更有效的治疗靶点。