The role of Itgam+ pulmonary macrophage populations in the pathogenesis and long-term effects of bronchopulmonary dysplasia.

Itgam 肺巨噬细胞群在支气管肺发育不良的发病机制和长期影响中的作用。

• 批准号: 531878612
• 负责人: Dr. Ivana Mizik, Ph.D.
• 金额: --
• 依托单位: Klinik und Poliklinik für Kinder- und Jugendmedizin
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/531878612?language=en
• 关键词: role; Itgam+; pulmonary; macrophage; populations

Bronchopulmonary dysplasia (BPD) is the most common neonatal chronic lung disease in premature infants, characterized by an arrest of alveolar and microvascular development. BPD develops following O2 and ventilator therapy for acute respiratory failure and is associated with life-long complications, including asthma, pulmonary hypertension, and emphysema. Currently, BPD lacks curative or preventive strategies. Oxygen-triggered inflammation plays a critical role in BPD pathogenesis. However, the key immune populations driving the injury remain unidentified. Moreover, it is unknown to which extent changes to immune cells persist after recovery and increase susceptibility to lung diseases later in life. The preliminary data show that hyperoxia triggers the trans-differentiation of macrophages (MFs) towards the yet unexplored pro-inflammatory Itgam+/Inhba+ phenotype. We hypothesize that Itgam+/Inhba+ MFs constitute the main source of pro-inflammatory signaling targeting the lung endothelial and stromal cells and play a causal role in BPD pathogenesis. To address this hypothesis, we pursue three specific aims: (1) To profile the long-term effects of hyperoxia on the phenotype and dynamics of Itgam+/Inhba+ MFs and other immune cells during recovery using single cell (sc)RNA-seq. Mice will be exposed to hyperoxia from birth until postnatal day (P)14, followed by recovery in room air until P70. Lung Itgam+ MFs will be isolated and profiled. Importantly, we will create a lung scRNA-seq atlas following the hyperoxia-injury, focusing on the Itgam+ MFs and their communication with other lung cell populations. (2) To Investigate the effects of hyperoxia on Itgam+ MFs and the impact of hyperoxic Itgam+ MFs on alveolar formation in vitro/ex vivo. To study acute effects of hyperoxia we will expose Itgam+ MFs to hyperoxia in vitro and evaluate transcriptional changes and changes in cytokines/chemokines production. Further, we will co-culture precision cut lung slices from healthy developing mice with hyperoxic Itgam+ MFs and evaluate changes in proliferation, cell death, and alveolar growth. (3) To investigate the causal role of Itgam+ MFs in an in vivo model of BPD on histological and functional level. 3a: Determining the functional role of Itgam+ MFs by transplanting primary Itgam+ MFs from hyperoxia-exposed mice to healthy developing mice. 3b: Analysing the causal role of Itgam+ MFs by depletion of Itgam+ cells in hyperoxia-exposed Itgam-cre/ROSA-DTA mice. Lung architecture, vasculature and function, and cell survival will be assessed. The strengths of this proposal include the use of novel scRNA-seq and systems biology approaches together with readily available animal models, well-established techniques, as well as possible clinical implications. Completion of this project will provide new mechanistic insights in macrophage biology in BPD and offer new possible therapeutic strategies, which might also be relevant for adult emphysematous chronic lung diseases.

支气管肺发育不良（BPD）是早产儿中最常见的新生儿慢性肺部疾病，其特征是肺泡和微血管发育停滞。BPD在O2和呼吸机治疗急性呼吸衰竭后发生，并与终身并发症相关，包括哮喘、肺动脉高压和肺气肿。目前，BPD缺乏治疗或预防策略。氧触发的炎症在BPD发病机制中起关键作用。然而，驱动损伤的关键免疫群体仍未确定。此外，目前还不清楚恢复后免疫细胞的变化在多大程度上持续存在，并增加日后对肺部疾病的易感性。初步数据显示，高氧触发巨噬细胞（MF）向尚未探索的促炎Itgam+/Inhba+表型的转分化。我们假设Itgam+/Inhba+ MFs构成了靶向肺内皮细胞和基质细胞的促炎信号的主要来源，并在BPD发病机制中发挥因果作用。为了解决这一假设，我们追求三个具体目标：（1）使用单细胞（sc）RNA-seq来描绘高氧对恢复期间Itgam+/Inhba+ MF和其他免疫细胞的表型和动力学的长期影响。小鼠从出生到出生后第14天（P）暴露于高氧，然后在室内空气中恢复直至P70。将对肺Itgam+ MF进行分离和分析。重要的是，我们将在高氧损伤后创建肺scRNA-seq图谱，重点关注Itgam+ MFs及其与其他肺细胞群的通讯。(2)研究高氧对Itgam+ MFs的影响以及高氧Itgam+ MFs对体外/离体肺泡形成的影响。为了研究高氧的急性效应，我们将Itgam+ MF在体外暴露于高氧，并评估转录变化和细胞因子/趋化因子产生的变化。此外，我们将用高氧Itgam+ MF共培养来自健康发育小鼠的精确切割的肺切片，并评估增殖、细胞死亡和肺泡生长的变化。(3)在组织学和功能水平上研究Itgam+ MFs在BPD体内模型中的因果作用。3a：通过将来自高氧暴露小鼠的原代Itgam+ MF移植至健康发育小鼠来确定Itgam+ MF的功能作用。3b：通过消耗高氧暴露的Itgam-cre/ROSA-DTA小鼠中的Itgam+细胞来分析Itgam+ MF的因果作用。将评估肺结构、血管系统和功能以及细胞存活。该提案的优势包括使用新的scRNA-seq和系统生物学方法，以及现成的动物模型，成熟的技术以及可能的临床意义。该项目的完成将为BPD中的巨噬细胞生物学提供新的机制见解，并提供新的可能的治疗策略，这也可能与成人肺气肿性慢性肺病相关。