Role of gasdermin D in bone resorption

Gasdermin D 在骨吸收中的作用

基本信息

批准号：
9903077
负责人：
Gabriel Mbalaviele
金额：
$ 37.57万
依托单位：
WASHINGTON UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-02-15 至 2025-01-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/9903077
关键词：
Ablation Adverse effects Alcohol dependence Biochemical Bone Marrow Transplantation Bone Resorption Bone remodeling Cell Death Cell membrane Cells Chemotherapy and/or radiation Chronic Clinical Data Development Disease Disulfiram Dose Environment FDA approved Fracture Functional disorder Genetic Hematologic Neoplasms Immune Immune response In Vitro Inflammasome Inflammation Inflammatory Interleukin-1 Interleukin-1 beta Interleukin-18 Knockout Mice Lipopolysaccharides Membrane Mus Mutate Osteoclasts Osteogenesis Osteolysis Participant Pathologic Pathology Periodicity Pharmacology Pharmacotherapy Play Procedures Process Production Proteins Radiation Radiation therapy Rare Diseases Regimen Research Role Rupture Septic Shock Signal Transduction Structure Syndrome Testing Transplant Recipients VDAC1 gene autoinflammatory bone bone loss bone mass bone turnover cancer cell chemotherapy conditioning cytokine drug discovery extracellular inflammatory bone loss loss of function mouse model prevent radioresistant recruit response skeletal tissue repair

项目摘要

The study of rare diseases often informs more common pathologies. We have extensively studied the NLRP3 inflammasome, which is mutated in autoinflammatory disorders such as cryopyrin-associated periodic syndromes (CAPS). A major feature of these conditions is excessive production of IL-1β, which is also highly induced by procedures such as radiotherapy and chemotherapy, commonly used to kill malignant cells or as a conditioning regimen for bone marrow transplantation (BMT). IL-1β potently promotes bone resorption while simultaneously inhibiting bone formation, but IL-1 blocking agents have limited efficacy in the treatment of syndrome-associated bone pathologies. This suggests that other actions of the inflammasomes beyond IL-1β processing, contribute to adverse skeletal effects in diseases. The inflammasomes are responsible for the maturation of IL-1β and IL-18. Recent studies have identified GSDMD as an additional critical substrate of the inflammasomes. Activated GSDMD translocates to the plasma membrane where it forms pores through which IL-1β and IL-18 are secreted. However, excessive pore formation compromises membrane integrity, releasing pro-inflammatory cytoplasmic contents into the extracellular environment. This form of cell death, termed pyroptosis is inflammatory. Thus, while GSDMD is a normal participant in immune responses and tissue repair, its chronic activation promotes inflammation. We surmise that the concomitant release of multiple inflammatory factors during pyroptosis causes pathological bone loss. Therefore, inhibition of GSDMD could provide superior efficacy over IL-1 blockade, not only in the context of CAPS, but also radiation and chemotherapy. Recent drug discovery efforts have identified disulfiram as an antagonist of GSDMD-pore forming activity. Disulfiram is an FDA-approved drug for the treatment of alcohol addiction. We found that administration of disulfiram to mice inhibited LPS-stimulated IL-1β production. Disulfiram also inhibited IL-1β secretion, pyroptosis and osteoclast (OC) differentiation in vitro. To further study the role of GSDMD in bone resorption, we determined skeletal impact of GSDMD loss-of-function in mouse models. Preliminary results indicate that baseline bone mass was higher in Gsdmd-/- compared to WT mice. Moreover, the exuberant OC formation that occurred in CAPS mice was normalized upon Gsdmd ablation. Gsdmd null mice were also resistant to radiation/BMT-induced bone loss. In vitro data further demonstrated that expression of GSDMD was up- regulated during OC differentiation, and genetic ablation of this protein decreased OC formation. These results suggest that GSDMD is functional in OC without compromising their survival, and regulates bone resorption. The central hypothesis of this proposal is that GSDMD regulates bone resorption in pathological conditions through mechanisms involving its actions in inflammatory cells and OC lineage. We will test this hypothesis in two Aims: Aim 1: Determine the role of GSDMD in bone resorption in pathological conditions. Aim 2: Define the role of GSDMD in the OC lineage and elucidate the mechanisms of its activation in these cells.

对罕见疾病的研究通常会导致更常见的病理。我们已经广泛研究了NLRP3 炎性体，在自自炎症中突变，例如冷冻蛋白相关的周期性综合征（上限）。这些条件的主要特征是过度产生IL-1β，这也是高度的通过放疗和化学疗法等程序诱导，通常用于杀死恶性细胞或作为骨髓移植（BMT）的调节方案。 IL-1β有可能促进骨骼分辨率，而类似地抑制骨形成，但是IL-1阻断剂的治疗效率有限综合征相关的骨骼病理。这表明IL-1β之外的炎症症的其他作用处理，导致疾病的不良骨骼影响。炎症体负责 IL-1β和IL-18的成熟。最近的研究已将GSDMD确定为额外的关键基材炎症。激活的GSDMD转移到质膜，形成孔。 IL-1β和IL-18分泌。但是，多余的孔形成会损害膜完整性，释放促炎性细胞质含量进入细胞外环境。这种细胞死亡形式，称为凋亡是炎症性的。虽然GSDMD是免疫反应和组织修复的正常参与者，但它的慢性激活促进了感染。我们浏览多种炎症的伴随释放凋亡过程中的因素会导致病理骨质流失。因此，抑制GSDMD可以提供不仅在CAP的背景下，而且放射疗法和化学疗法，都超过IL-1阻断的效率。最近的药物发现工作已经确定二硫仑是GSDMD孔形成活性的对手。二硫仑是一种由FDA批准的药物，用于治疗酒精成瘾。我们发现管理对小鼠的二硫次抑制了LPS刺激的IL-1β产生。二硫仑还抑制IL-1β分泌，体外凋亡和破骨细胞（OC）分化。为了进一步研究GSDMD在骨骼分辨率中的作用，我们确定了小鼠模型中GSDMD功能丧失的骨骼影响。初步结果表明与WT小鼠相比，GSDMD - / - 的基线骨量更高。而且，旺盛的OC形成在GSDMD消融时，将发生在CAPS小鼠中。 GSDMD无效小鼠也具有抗性辐射/BMT诱导的骨质流失。体外数据进一步表明，GSDMD的表达是上升的在OC分化过程中调节，该蛋白质的遗传消融改善了OC的形成。这些结果表明GSDMD在OC中起作用，而不会损害其存活情况，并调节骨骼分辨率。该提议的中心假设是GSDMD在病理条件下调节骨骼分辨率通过涉及其在炎症细胞和OC谱系中作用的机制。我们将在两个目的：目标1：确定GSDMD在病理条件下骨骼分辨率中的作用。目标2：定义 GSDMD在OC谱系中的作用并阐明了其在这些细胞中激活的机制。