Neutrophil Biomarker and neutrophil targeted therapy to predict and prevent heterotopic ossification

项目摘要 异位骨化(HO)是骨外骨骼的病理性形成，发生在~20%的 髋关节置换术后的患者，肌肉骨骼损伤或烧伤，而这一比例上升到80%以上 在高能损伤患者中牵涉到先天免疫反应的作用。标准化 预防HO的治疗方案缺失，手术切除HO未能恢复损伤前的功能 容量大，复发风险高。Ho，无论是什么煽动事件，最常见的是在现场形成 机动性。一旦确诊为HO，医生就会限制受影响关节的运动，以限制进展， 然而，限制流动性以改变炎症和HO进展的机制仍不清楚。 更复杂的治疗是，目前还没有生物标记物来指导临床医生 患者处于HO的高风险中，因此应该接受预防以及何时开始治疗。因此， 有大量的临床需要开发一种有效的、炎症靶向的HO疗法，并验证 指导患者选择和精确治疗时机的生物标记物。该提案将为以下项目生成数据集 这两个未得到满足的临床需求为HO的更有效干预提供了突破。 我们小组最近对HO损伤进行了新的动态分析，确定中性粒细胞表型是中心 致贺。具体地说，我们发现中性粒细胞释放的结构性成分，即中性粒细胞 胞外陷阱(Nets)在HO中起着关键作用。这是一个新的方面，如何先天免疫反应 对Ho有贡献。据报道，组织损伤促使网络的形成，以防止感染 (原发NET病)。HO是独一无二的，因为它形成在流动性的位置，这增加了放置在 还没有被研究过的网。初步数据显示，关节的运动扰乱了初级网络 诱导NETs(继发性网虫病)的传播，这对HO的发展至关重要。我们发现了这本专门针对Ho的小说 其机制是通过Toll样受体9(TLR9)介导的，TLR9是一种已知的DNA复合体受体。因此，我们 提出TLR9是一个针对HO的新靶点。 目的1：评价Nets作为预测HO形成的生物标志物的作用。我们将评估差分网 在我们的小鼠模型和特征良好的人类患者中，HO形成与非HO对照的比较 HO(髋关节置换术)的风险队列检查损伤部位和全身净值作为HO生物标志物。 目的2：研究TLR9在二次网络形成中的作用和治疗潜力 HO形成和进展中的信号转导。我们还将评估药物对TLR9的抑制能力 以及中性粒细胞特异性TLR9的缺失，以减轻已证实的小鼠模型中的继发性网络沉着症和HO。

Project Summary Heterotopic ossification (HO) is the pathologic formation of extra-skeletal bone that occurs in ~20% of patients after hip arthroplasty, musculoskeletal trauma or burns, whereas this incidence increases to over 80% in patients with high energy injuries implicating the role of the innate immune response. Standardized treatment protocols to prevent HO are missing and surgical resection of HO fails to restore pre-injury functional capacity and has a high risk of recurrence. HO, regardless of the inciting event, most commonly forms at sites of mobility. Once HO is diagnosed, physicians restrict movement of the effected joint to limit progression, however, the mechanism behind limiting mobility to alter inflammation and HO progression remains unknown. Further complicating treatment is the fact that there are currently no biomarkers to guide clinicians on which patients are at high HO risk and therefore should receive prophylaxis and when to initiate treatment. Thus, there is a substantial clinical need to develop an effective, inflammatory targeted HO therapy and to validate a biomarker to guide patient selection and precise therapeutic timing. This proposal will generate data sets for those two unmet clinical needs to provide a breakthrough towards more efficient intervention for HO. Recent novel dynamic analyses of HO injuries by our group have identified neutrophil phenotype as central to HO. Specifically, we found that structural components released by neutrophils, known as neutrophil extracellular traps (NETs), play a critical role in HO. This is a novel aspect how the innate immune response contributes to HO. It is reported that tissue injury prompts formation of NETs for prevention of infections (primary NETosis). HO is unique as it forms in sites of mobility which adds a unique force (extrinsic) placed on NETs which has not been studied. Preliminary data demonstrates that motion of a joint disrupts primary NETs to induce propagation of NETs (secondary NETosis), critical to develop HO. We found this HO-specific novel mechanism is mediated by toll-like receptor 9 (TLR9), a known receptor for DNA complexes. Therefore, we propose that TLR9 is a novel target specific to HO. Aim 1: Evaluate the role of NETs as a biomarker to predict HO formation. We will evaluate differential NET formation in HO compared to non-HO control in our mouse models and in a well characterized human patient cohort at risk for HO (hip arthroplasty) to examine injury site and systemic NET levels as a HO biomarker. Aim 2: Characterize the role and therapeutic potential specific to secondary NET formation through TLR9 signaling in HO formation and progression. We will also assess the ability of pharmacologic TLR9 inhibition and neutrophil specific Tlr9 deletion to mitigate secondary NETosis and HO in proven mouse models.