Urinary Lipidomic profile in FSGS: A novel biomarker

局灶性节段性肾小球硬化(FSGS)是最常见的肾小球病变，导致 儿童时期肾脏疾病的进展和终末期。缺乏非侵入性、 预测FSGS诊断、预后和结局的可靠生物标志物。此外， FSGS的诊断可能会被推迟，因为大多数肾病综合征患者没有接受 肾脏活检，直到类固醇治疗失败。循环中脂质浓度升高 细胞内脂质沉积是FSGS的常见表现。然而，血脂异常是如何 与进步有关的问题仍未解决。我们发现了一个独特的尿脂代谢产物组 通过非靶向脂质组学分析预测FSGS的诊断和预后。 FSGS患者尿中溶血磷脂酰胆碱(LPC)浓度升高 和游离脂肪酸(FFA)。我们建议将这种磷脂配置文件作为一种 生物标记物组合是预测FSGS诊断、预后和监测的有力工具 对治疗的反应。该提案的SA-1将进一步验证磷脂和游离脂肪酸的使用 通过测量患者基线血清和尿样中的这些脂代谢产物 收集在FSGS和微小病变病(MCD)患者的全国队列中 (海王星)通过靶向脂质分析。登记的患者已完成至少5年的 后续行动。我们将评估临床结果(尿蛋白变化)之间的相关性 排泄物和肾功能)和患者生物样本中脂代谢产物的浓度 在海王星入口处获得。我们将调查敏感度、特异度、阳性预测值 脂生物标志物在FSGS诊断和预后中的价值及阴性预测价值。Sa- 将研究动物尿液LPC和FFA升高的机制 FSGS模型。我们发现胞浆磷脂酶A2(CPLA2)的活性增加。 足细胞和足细胞中膜磷脂酰胆碱分解为LPC和FFA的酶 FSGS小鼠模型中的肾小管上皮细胞。在SA-2中，我们的目标是研究 CPLA2在Fyn-/-CD2AP+/-双基因FSGS小鼠模型细胞损伤和FSGS进展中的作用 CPLA2基因敲除。在小鼠实验的同时，我们将使用BuffaloMna大鼠 研究cPLA2在自发性FSGS模型中的表达。我们假设抑制作用 CPLA2的表达可减轻FSGS的细胞损伤和进展。 在这项研究提案中，我们的目标是开发一种新的脂类代谢物生物标志物小组，该小组将 有助于FSGS的诊断和预后预测。此外，这一新型生物标志物面板 将改进监测治疗反应的方式。脂类作用机制的研究进展 介导性损伤将导致FSGS新的治疗方法的发展。我们的首要目标是 通过开发新的诊断和预后方法改善FSGS患者的护理和预后 脂类生物标记物小组，指向调节失调的脂类途径。

Focal segmental glomerulosclerosis (FSGS) is the most common glomerular pathology that leads to progression and end-stage kidney disease during childhood. There is a lack of non-invasive, reliable biomarkers that predict the diagnosis, prognosis and outcome of FSGS. Furthermore, FSGS diagnosis can be delayed as most of the patients with nephrotic syndrome do not undergo kidney biopsies until they have failed steroid therapy. Increased concentrations of circulating lipids and intracellular lipid deposits is a common finding in FSGS. However how lipid anomalies are linked to progression remains unsolved. We discovered a distinct urinary lipid metabolite panel in FSGS that predicted the diagnosis and prognosis of FSGS by untargeted lipidomics analysis. Patients with FSGS displayed increased urinary concentrations of lysophosphotidycholine (LPC) and free fatty acids (FFA). We propose that implementation of this phospholipid profile as a biomarker panel is a powerful tool in prediction of diagnosis and prognosis of FSGS and to monitor response to treatment. SA-1 of this proposal will further validate the use of phospholipid and FFA panel by measuring these lipid metabolites in baseline serum and urine samples of patients collected in a national cohort of patients with FSGS and minimal change disease (MCD) (NEPTUNE) by targeted lipid analysis. The enrolled patients have completed at least 5 years of follow-up. We will assess the correlation between clinical outcomes (change in urine protein excretion and kidney function) and concentrations of the lipid metabolites in patient biosamples obtained at the entry to NEPTUNE. We will investigate sensitivity, specificity, positive predictive value, and negative predictive value of lipid biomarkers in diagnosis and prognosis of FSGS. SA- 2 of this proposal, will examine the mechanism of increased urinary LPC and FFA in an animal model of FSGS. We demonstrated increased activation of cytosolic phospholipase A2 (cPLA2) enzyme that breaks down membrane phosphotidylcholines to LPC and FFA in podocytes and tubular epithelial cells in a mouse model of FSGS. In SA-2 our goal is to investigate the role of cPLA2 in cellular injury and progression of FSGS in Fyn–/–Cd2ap+/– bigenic FSGS mouse model with cPLA2 gene knock-out. In parallel with mouse experiments, we will use BuffaloMna rats to investigate cPLA2 expression in this spontaneous FSGS model. We hypothesize that inhibition of cPLA2 will alleviate cellular injury and progression in FSGS. In this research proposal our goal is to develop a novel lipid metabolite biomarker panel that will aid in prediction of diagnosis and prognosis of FSGS. Furthermore, this novel biomarker panel will improve the way treatment response is monitored. Delineation of the mechanism of lipid mediated injury will lead to development of novel treatments in FSGS. Our overarching goal is to improve the care and outcome of FSGS patients by developing novel diagnostic and prognostic lipid biomarker panel that is directed to dysregulated lipid pathways.