Identification of osteoclast endocrine and paracrine communications by systems genetics approaches

破骨细胞的骨吸收在骨骼生长、动态平衡和骨折修复中起着关键作用。在……里面 成年人的骨骼健康是通过骨重建来确保的，在骨重建中，骨吸收通过骨来耦合和平衡 由成骨细胞形成。因此，破骨细胞的数量和活性受到全身性的严格调控。 骨髓微环境中的激素和旁分泌因子。与此同时，骨骼本身也越来越多地 在全身生理学中被认为是能调节其他器官功能的内分泌器官。 而成骨细胞和骨细胞来源的内分泌因子的系统功能，如FGF23和 骨钙素已得到很好的证实，破骨细胞分泌蛋白的内分泌功能尚待研究 没有遮盖物。为了识别和功能注释内分泌和旁分泌回路，我们开发了一种新的 系统遗传学方法，称为定量内分泌网络相互作用估计(QENIE)，利用 多个组学数据集中组织间转录水平的自然变化以预测内分泌模式 沟通。将这种方法应用于混合鼠标多样性小组(HMDP)中的数据集，该小组是 大约100个近交系小鼠，表现出与人类相关的大多数临床特征的巨大多样性 对于疾病，我们已经揭开了许多已知的内分泌相互作用以及几个新的组织-组织回路。 在导致这一建议的初步研究中，我们已经定量测量了蛋白质和 基于蛋白质组学和批量RNA序列的质谱学方法研究前体和成熟破骨细胞中的RNA。 这些“组学”研究已经确定了破骨细胞系细胞中的数百种分泌蛋白。而当 已知的几种破骨细胞衍生的偶联因子在骨重建过程中刺激成骨 破骨细胞分泌蛋白列表，其中大多数新鉴定的内分泌和旁分泌功能 破骨细胞分泌蛋白是未知的。根据我们的工作和其他人的报告，我们假设 破骨细胞的内分泌和旁分泌通讯在全身和骨骼中起着重要的作用 生理和病理条件下的动态平衡。为了检验我们的假设，我们将确定小说 系统遗传学生物信息学框架下破骨细胞系细胞的内分泌和旁分泌回路 QENIE(Aim 1)，并通过体外实验验证和功能评估这些破骨细胞衍生因子 细胞培养和共培养模型(目标2)。成功完成本申请中的拟议工作 将制定新的假设，并使用活体动物模型和人类群体进行测试。调查结果 不仅将极大地促进我们对破骨细胞生物学的了解，而且还将发现新的 治疗骨丢失和其他器官疾病的治疗靶点。

Bone resorption by osteoclasts plays a pivotal role in skeleton growth, homeostasis, and fracture repair. In adults, bone health is ensured by bone remodeling in which bone resorption is coupled and balanced by bone formation from osteoblasts. Therefore, the number and activities of osteoclasts are tightly regulated by systemic hormones and paracrine factors in bone marrow microenvironment. Meanwhile, bone itself is increasingly recognized as an endocrine organ which can modulate functions of other organs in whole-body physiology. While the systemic functions of endocrine factors derived from osteoblasts and osteocytes such as FGF23 and osteocalcin have been well established, the endocrine functions of osteoclast secreted proteins remain to be uncovered. To identify and functionally annotate endocrine and paracrine circuits, we have developed a novel systems genetic approach, termed Quantitative Endocrine Network Interaction Estimation (QENIE), that utilizes natural variation in transcript levels across tissues in multiple ‘omics’ datasets to predict modes of endocrine communication. Applying this approach to datasets in the hybrid mouse diversity panel (HMDP), a collection of approximately 100 inbred strains of mice exhibiting substantial diversity of most clinical traits relevant to human diseases, we have unraveled many known endocrine interactions as well as several novel tissue-tissue circuits. In the preliminary study leading to this proposal, we have quantitatively measured the levels of proteins and RNAs in precursor and mature osteoclasts by mass-spectrometry based proteomic and bulk RNA-seq. Hundreds of secreted proteins in osteoclast lineage cells have been identified by these ‘omics’ studies. While several osteoclast-derived coupling factors known to stimulate osteogenesis during bone remodeling are in the list of osteoclast secreted proteins, the endocrine and paracrine functions of most of these newly identified osteoclast secretory proteins are unknown. Based on our work and reports by others, we hypothesize that the endocrine and paracrine communications of osteoclasts play an important role in whole body and bone homeostasis under physiological and pathological conditions. To test our hypothesis, we will identify novel endocrine and paracrine circuits of osteoclast lineage cells by the system genetics bioinformatic framework QENIE (Aim 1) and experimentally validate and functionally assess these osteoclast-derived factors by in vitro cell culture and co-culture models (Aim 2). Successful accomplishment of the proposed work in this application will formulate new hypotheses to be tested using in vivo animal models and in human populations. The findings from this project will not only greatly advance our knowledge in osteoclast biology but also uncover new therapeutic targets to treat bone loss in bone and other organ diseases.