A platelet-fibroblast axis connecting bioenergetics and metabolism in SSc-pulmonary arterial hypertension

肺动脉高压(PAH)是一种与系统性硬化症(SSc-PAH)相关的致命疾病。 并且依赖于几种血管细胞类型。然而，分子串扰的关键系统仍然存在 神秘莫测。之前，我们定义了转录共激活因子YAP/TAZ之间的关键调节轴 谷氨酰胺酶，建立了谷氨酰胺代谢如何与血管相关的新范式 硬度(以PAH表示)。然而，关键问题依然存在。激活YAP/TAZ以启动PAH和 它们是否起源于不同的细胞类型？在这些触发因素的下游，血管谷氨酰胺代谢 可作为SSc-PAH的诊断指标吗？我们未发表的数据表明，自闭症患者的血小板 显示异常的线粒体能量与血管症状的严重程度相关 并导致肺外膜成纤维细胞谷氨酰胺分解增加。假设：血小板改变 能量向PA成纤维细胞发出信号，导致谷氨酰胺代谢的特异性变化以控制 胶原沉积、血管僵硬和SSC-PAH。在此翻译提案中，我们将定义 SSc-PAH患者存在血小板能量和成纤维细胞谷氨酰胺代谢异常。我们还将 确定成纤维细胞谷氨酰胺摄取是否可以作为开发更有效的诊断的靶点。目标 1)确定调节失调的血小板能量是否与血管的严重程度有关 SSc的症状和SSc-PAH的肺血管成纤维细胞谷氨酰胺分解。我们假定 功能障碍的血小板能量学可作为进行性血管损伤的生物标志物 与SSc-PAH中肺外膜成纤维细胞谷氨酰胺分解增加有关。为了进行调查， 将从SSc-PAH患者、SSC患者和对照患者中分离血小板，并分析能量谱和 与临床血管测量指标相关。同时，对人SSC-1的单细胞RNA测序 PAH与对照外植体肺将确定血小板能量转录谱是否与血管相关 成纤维细胞谷氨酰胺分解谱。目的2)利用18F-氟谷氨酰胺PET显像测定谷氨酰胺 SSC-PAH与对照组的摄取。我们发现肺血管和右肺对谷氨酰胺的摄取增加 用18F-FGln示踪剂的正电子发射计算机断层扫描和波谱成像(MIMS)对啮齿动物PAH的脑室进行定量。 15N-谷氨酰胺。在一项首次人类研究中，我们将研究SSC-PAH患者与单纯SSC患者的18F-FGln PET/CT 和非疾病对照。这一目标将确定人类SSc-PAH和谷氨酰胺代谢的相关性 18F-FGln作为SSc-PAH诊断示踪剂的潜力意义：我们的多学科 该团队在确定关键的血小板-成纤维细胞代谢途径的临床相关性方面具有独特的地位 用于诱导血管僵硬和PAH。我们将利用这些发现进行人类第一次诊断 18F-FGln PET/CT的研究总之，我们将定义汇聚在血小板和成纤维细胞上的细胞间轴。 SSC-PAH的新陈代谢，从而为这一致命疾病提供急需的有针对性的诊断。

Pulmonary arterial hypertension (PAH) is a deadly disease associated with systemic sclerosis (SSc-PAH) and is dependent on several vascular cell types. However, key systems of molecular cross-talk remain enigmatic. Previously, we defined a key regulatory axis between the transcriptional coactivators YAP/TAZ with the enzyme glutaminase, establishing a new paradigm of how glutamine metabolism is related to vascular stiffness in PAH. Yet, crucial questions remain. What are the triggers that activate YAP/TAZ to initiate PAH and do they originate from separate cell types? Downstream of those triggers, can vascular glutamine metabolism serve as a diagnostic indicator of SSc-PAH? Our unpublished data demonstrate that platelets from SSc patients show dysregulated mitochondrial energetics which correlate with the severity of vascular manifestations in these patients and cause increased glutaminolysis in pulmonary adventitial fibroblasts. Hypothesis: Altered platelet energetics signal to PA fibroblasts, resulting in specific alterations of glutamine metabolism to control collagen deposition, vascular stiffness, and SSc-PAH. In this translational proposal, we will define the presence of dysregulated platelet energetics and fibroblast glutamine metabolism in SSc-PAH. We will also determine if fibroblast glutamine uptake can be targeted for the development of more effective diagnostics. Aim 1) Determine whether dysregulated platelet energetics is associated with the severity of vascular symptoms in SSc and with lung vascular fibroblast glutaminolysis in SSc-PAH. We postulate that dysfunctional platelet energetics can serve as a biomarker of progressive vascular damage in SSc and is associated with increased glutaminolysis in pulmonary adventitial fibroblasts in SSc-PAH. To investigate, platelets will be isolated from SSc-PAH, SSc, and control patients and energetic profiles will be analyzed and correlated with measures of clinical vascular measures. In parallel, single cell RNA sequencing of human SSc- PAH vs. control explant lungs will determine if platelet energetic transcriptional profiles correlate with vascular fibroblast glutaminolytic profiles. Aim 2) Utilize 18F-fluoroglutamine PET imaging to measure glutamine uptake in SSc-PAH vs. controls. We found increased glutamine uptake into pulmonary vessels and right ventricle in rodent PAH, as quantified by PET imaging of a 18F-FGln tracer and by spectral (MIMS) imaging of 15N-glutamine. In a first-in-human study, we will investigate 18F-FGln PET/CT in SSc-PAH patients vs. SSc alone and non-diseased controls. This aim will define the relevance of glutamine metabolism in human SSc-PAH and the potential of 18F-FGln to serve as a novel diagnostic tracer for SSc-PAH. Significance: Our multi-disciplinary team is uniquely positioned to define the clinical relevance of a platelet-to-fibroblast metabolism pathway critical for inducing vascular stiffening and PAH. We will leverage those findings to embark on a first-in-human diagnostic study of 18F-FGln PET/CT. In sum, we will define the intercellular axes that converge upon platelet and fibroblast metabolism in SSc-PAH, thus offering much needed targeted diagnostics in this deadly disease.