Novel Targets of Rituximab in FSGS

FSGS 中利妥昔单抗的新靶点

• 批准号: 8707439
• 负责人: ALESSIA FORNONI
• 金额: $ 33.28万
• 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/8707439
• 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）：移植后复发性局灶节段性肾小球硬化症 (FSGS) 是一种非常普遍的病症，利妥昔单抗（一种抗 CD20 的单克隆抗体）可能具有潜在的适应症。除 CD20 外，利妥昔单抗已被证明可以结合鞘磷脂磷酸二酯酶样 3b 前体 (SMPDL-3b) 并调节酸性鞘磷脂酶 (ASMase)。 我们测试了利妥昔单抗通过保留足细胞 SMPDL-3b 表达和活性来预防移植后复发 FSGS 的假设。我们对 41 名复发 FSGS 高风险患者的初步研究表明，利妥昔单抗治疗与移植后蛋白尿发生率降低和 eGFR 降低相关。在后来出现复发性疾病的患者中，再灌注后活检中 SMPDL-3b 阳性细胞的数量减少。 利妥昔单抗部分阻止了在用受影响患者血清处理的足细胞中观察到的 SMPDL-3b 下调。 利妥昔单抗和 SMPDL-3b 过表达均可阻止肌动蛋白细胞骨架的破坏和患者血清诱导的细胞凋亡，这种作用在 SMPDL-3b 基因沉默的细胞中减弱。体外应力纤维破坏的定量分析与移植后蛋白尿的程度相关，这表明开发复发性 FSGS 预测测定的可能性。 我们大学是招募大量 FSGS 患者的最佳临床基地之一。我们建议对所有接受肾移植的原发性 FSGS 患者进行一项试点研究，作为实验研究的饲养者。 我们将收集临床数据作为二次探索性分析。将按照方案收集随机接受利妥昔单抗或安慰剂的患者的再灌注后肾活检和移植前血清。肾活检和暴露于患者血清的培养足细胞中的 SMPDL-3b 表达将用于研究疾病机制并进行与临床结果的关联研究。将利用细胞骨架重塑、细胞活力、传统裂隙隔膜蛋白表达和定位以及细胞脂质组成来研究利妥昔单抗是否以 SMPDL-3b 依赖性方式保护足细胞。我们的研究非常重要，因为它具有很强的临床意义，因为它可能会导致批准的利妥昔单抗治疗 FSGS 以及其他蛋白尿疾病的适应症发生变化。这项研究具有创新性，因为它将为足细胞功能中鞘磷脂相关酶的作用提供新的见解，从而确定抗蛋白尿药物开发的新靶点。最后，我们用患者血清处理正常人足细胞的体外试验可能成为识别高危患者的移植前评估测试。