Novel Targets of Rituximab in FSGS

FSGS 中利妥昔单抗的新靶点

• 批准号: 8512589
• 负责人: SANDRA MERSCHER
• 金额: $ 32.11万
• 依托单位: UNIVERSITY OF MIAMI SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-30 至 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8512589
• 关键词: Accounting; Acids; Actins; Affect; Allografting; Antibodies; Apoptosis; B-Lymphocytes; Binding; Biological Assay; Biological Preservation; Biopsy; Cell Survival; Cell membrane; Cells; Ceramides; Cessation of life; Childhood; Clinical; Clinical Data; Complication; Cytoskeleton; Data; Disease; Disease remission; Down-Regulation; End stage renal failure; Enrollment; Ensure; Enzymes; Exposure to; Focal Segmental Glomerulosclerosis; Future; Generations; Genes; Human; In Vitro; Incidence; Kidney; Kidney Transplantation; Lead; Lipids; Lymphoma; Lymphoproliferative Disorders; MS4A1 gene; Mediating; Membrane Microdomains; Molecular; Monoclonal Antibodies; Outcome; Participant; Patients; Pilot Projects; Placebos; Proteinuria; Protocols documentation; Randomized; Recurrence; Recurrent disease; Reperfusion Therapy; Reporting; Risk; Role; Selection Bias; Serum; Signal Transduction; Sphingomyelinase; Stress Fibers; Testing; Time; Transplantation; Universities; acid sphingomyelinase; arm; assay development; base; disease mechanisms study; drug development; experience; genetic manipulation; high risk; in vitro Assay; innovation; insight; kidney cell; novel; overexpression; patient population; podocyte; prevent; prophylactic; protein expression; research study; rituximab; slit diaphragm; young adult

DESCRIPTION (provided by applicant): Recurrent focal segmental glomerulosclerosis (FSGS) after transplantation is a highly prevalent condition where rituximab (a monoclonal antibody against CD20) may have a potential indication. Besides CD20, rituximab has been shown to bind sphingomyelin-phosphodiesterase-like-3b-precursor (SMPDL-3b) and to regulate acid-sphyngomyelinase (ASMase). We tested the hypothesis that rituximab prevents recurrent FSGS after transplantation via preservation of podocyte SMPDL-3b expression and activity. Our preliminary study in 41 patients at high risk for recurrent FSGS demonstrated that rituximab treatment was associated with lower incidence of post-transplant proteinuria and with decreased eGFR. The number of SMPDL-3b positive cells in post-reperfusion biopsies was reduced in patients that would later develop recurrent disease. Rituximab partially prevented the SMPDL-3b down-regulation observed in podocytes treated with the sera of affected patients. Both rituximab and SMPDL-3b overexpression prevented the disruption of the actin cytoskeleton and the apoptosis induced by patient sera, an effect that was diminished in cells where SMPDL- 3b gene was silenced. Quantitative analysis of the disruption of stress fibers in vitro was associated with the degree of post-transplant proteinuria, suggesting the possibility of developing a prediction assay for recurrent FSGS. Our University offers one of the best clinical grounds for the recruitment of a large population of patients with FSGS. We propose to utilize a pilot study in all patients with primary FSGS who undergo kidney transplantation as a feeder for the experimental studies. We will collect clinical data that will serve as secondary exploratory analyses. Post-reperfusion kidney biopsies and pre-transplant sera will be collected per protocol in patients randomized to receive rituximab or placebo. SMPDL-3b expression in kidney biopsies and in cultured podocytes exposed to patient sera will be utilized to study disease mechanisms and to perform association studies with clinical outcomes. Cell cytoskeleton remodeling, cell viability, traditional slit diaphragm proteins expression and localization and cellular lipid composition will be utilized to study if rituximab protects podocytes in a SMPDL-3b dependent manner. Our study is highly significant because it has strong clinical implications, since it may lead to a change in the approved indications for rituximab treatment of FSGS as well as other proteinuric diseases. The proposed study is innovative because it will offer new insights into the role of shyngomyelin related enzymes in podocyte function, thus allowing the identification of novel targets for antiproteinuric drug development. Finally, our in vitro assay treating normal human podocytes with patient sera may become a pre-transplant assessment test for the identifications of patients at high-risk.

描述（由申请人提供）：移植后的复发性局灶性节段性肾小球硬化症（FSG）是一种高度普遍的条件，利妥昔单抗（利妥昔单抗针对CD20的单克隆抗体）可能具有潜在的指示。除CD20外，利妥昔单抗已显示出结合鞘磷脂蛋白 - 磷酸二酯酶样-3b-crencurs（SMPDL-3B）并调节酸 - 磷酸霉素酶（ASMASE）。 我们检验了以下假设：利妥昔单抗通过保存足细胞SMPDL-3B表达和活性来阻止移植后复发的FSG。我们对41例复发性FSG风险的41例患者的初步研究表明，利妥昔单抗治疗与移植后蛋白尿的发生率较低有关，而EGFR的发生率降低。在复发后活检中，SMPDL-3B阳性细胞的数量减少了，后来会出现复发性疾病。 利妥昔单抗部分阻止了在受影响患者血清治疗的足细胞中观察到的SMPDL-3B下调。 利妥昔单抗和SMPDL-3B过表达都阻止了肌动蛋白细胞骨架的破坏和患者血清诱导的凋亡，这种作用在SMPDL-3B基因的细胞中降低了。体外应力纤维破坏的定量分析与移植后蛋白尿的程度有关，这表明有可能开发针对经常性FSG的预测测定法。 我们的大学提供了招募大量FSG患者的最佳临床理由之一。我们建议在所有原发性FSG患者接受肾脏移植作为实验研究的饲养者的患者中使用试点研究。 我们将收集将作为次要探索性分析的临床数据。重新灌注后的肾脏活检和移植前血清将根据随机接受利妥昔单抗或安慰剂的患者进行。 SMPDL-3B在肾脏活检和暴露于患者血清的培养的足细胞中的表达将用于研究疾病机制，并与临床结果进行关联研究。如果利妥昔单抗以SMPDL-3B依赖性方式保护脚胞菌，将利用细胞细胞骨架重塑，细胞活力，传统的缝隙隔膜蛋白表达和定位以及细胞脂质组成。我们的研究非常重要，因为它具有强大的临床意义，因为它可能导致批准的利妥昔单抗治疗FSG和其他蛋白尿疾病的迹象发生变化。拟议的研究具有创新性，因为它将为害羞霉素相关酶在足细胞功能中的作用提供新的见解，从而允许鉴定出抗蛋白尿药物开发的新靶标。最后，我们用患者血清治疗正常人足细胞的体外测定可能会成为转移前评估测试，以对高危患者的鉴定。