Mechanisms of Drug Induced Phospholipidosis

药物诱导磷脂沉积的机制

基本信息

批准号：
8441941
负责人：
JAMES ALAN SHAYMAN
金额：
--
依托单位：
VETERANS HEALTH ADMINISTRATION
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-04-01 至 2017-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8441941
关键词：
Address Affect Alveolar Macrophages Amiodarone Amitriptyline Appearance Attention Azithromycin Basic Science Biological Assay Cell Line Cells Cellular biology Ceramides Charge Chemicals Chloroquine Chronic Clindamycin Clinical Clinical Research Complication Cultured Cells Development Disease Drug Approval Drug Prescriptions Drug Targeting Drug toxicity Drug usage Electrostatics Engineering Enzymes Fatty Acids Fluoxetine General Population Glycerophospholipids Grant Health Histology Imipramine In Vitro Inherited Inpatients Ketoconazole Knockout Mice Lead Lipids Lysosomal Storage Diseases Lysosomes Measures Membrane Lipids Metabolic Modeling Morbidity - disease rate Mus Mutate Mutation Names Patients Pharmaceutical Preparations Pharmacologic Substance Phenotype Phospholipase Phospholipase A2 Phospholipids Preclinical Drug Evaluation Predisposition Property Proteins Risk Role Scientist Secondary to Severities Single Nucleotide Polymorphism Susceptibility Gene Tamoxifen Testing Toxic effect Uncertainty United States Department of Veterans Affairs Veterans Work base burden of illness drug candidate drug development drug discovery drug mechanism enzyme mechanism enzyme substrate insight macrophage medical complication mortality novel patient population prevent programs public health relevance transacylation

Address Affect Alveolar Macrophages Amiodarone Amitriptyline Appearance Attention Azithromycin Basic Science Biological Assay Cell Line Cells Cellular biology Ceramides Charge Chemicals Chloroquine Chronic Clindamycin Clinical Clinical Research Complication Cultured Cells Development Disease Drug Approval Drug Prescriptions Drug Targeting Drug toxicity Drug usage Electrostatics Engineering Enzymes Fatty Acids Fluoxetine General Population Glycerophospholipids Grant Health Histology Imipramine In Vitro Inherited Inpatients Ketoconazole Knockout Mice Lead Lipids Lysosomal Storage Diseases Lysosomes Measures Membrane Lipids Metabolic Modeling Morbidity - disease rate Mus Mutate Mutation Names Patients Pharmaceutical Preparations Pharmacologic Substance Phenotype Phospholipase Phospholipase A2 Phospholipids Preclinical Drug Evaluation Predisposition Property Proteins Risk Role Scientist Secondary to Severities Single Nucleotide Polymorphism Susceptibility Gene Tamoxifen Testing Toxic effect Uncertainty United States Department of Veterans Affairs Veterans Work base burden of illness drug candidate drug development drug discovery drug mechanism enzyme mechanism enzyme substrate insight macrophage medical complication mortality novel patient population prevent programs public health relevance transacylation

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项目摘要

DESCRIPTION (provided by applicant) Drug toxicities represent a significant disease burden in the ambulatory and inpatient settings. Many drug toxicities are idiopathic in presentation and severity and often result in significant morbidity and mortality for those affected. Drug-induced phospholipidosis is one such toxicity. Drug-induced phospholipidosis is manifest as the intra-lysosomal accumulation of glycerophospholipids in association with the chronic use of commonly used pharmaceuticals. Specific examples of agents that cause phospholipidosis include, but are not limited to, azithromycin, fluoxetine, amiodarone, chloroquine, imipramine, and ketoconazole. Ascertaining the significance of this complication has been problematic for clinicians, as well as scientists and regulatory agencies overseeing drug discovery and approval. This is due to a limited understanding of the mechanisms responsible for phospholipidosis and the lack of suitable models for its study. Lysosomal phospholipase A2 is a recently discovered and characterized phospholipase that hydrolyzes those phospholipids that accumulate secondary to drug-induced phospholipidosis. In addition, mice engineered to express an inactive form of lysosomal phospholipase A2 develop a phenotype that closely resembles the clinical manifestations of this disorder. Specifically, these mice develop lysosomal phospholipid accumulation most prominently within their alveolar macrophages. When normal alveolar macrophages are exposed to amiodarone and additional phospholipidosis associated drugs, in vitro, lysosomal phospholipase A2 activity is inhibited in concert with phospholipid accumulation. Based on these observations, the primary hypothesis to be tested is that drug-induced phospholipidosis is the consequence of inhibition of lysosomal phospholipase A2. This grant will test this hypothesis by use of a newly developed fluorometric assay for lysosomal phospholipase A2 activity and the use of knockout mice that are partially or totally deficient in lysosomal phospholipase A2 activity. Also included in this project are mechanistic studies on the role of electrostatic charge interactions between the lysosomal phospholipase A2 protein and lipid membranes that contain the substrates for the enzyme. Finally, the association between common mutations in the lysosomal phospholipase A2 gene and susceptibility to drug-induced phospholipidosis will be studied by the expression of the mutated protein in cell lines. If the inhibition of lysosomal phospholipase A2 is demonstrated to be a primary mechanism for drug-induced hospholipidosis, then these findings may serve as both the basis for screening drugs that may cause this complication as well as for the identification of patients who may be uniquely sensitive to this form of drug toxicity.

描述（由申请人提供）药物毒性代表着门诊和住院环境中的重大疾病负担。许多药物毒性在表现和严重程度上是特发性的，通常会导致受影响者的发病率和死亡率显着。药物诱导的磷脂病是一种毒性。药物诱导的磷脂病显然表现为甘油磷脂的溶质体积累，以及长期使用常用药物。引起磷脂病的药物的特定例子包括但不限于阿奇霉素，氟西汀，胺碘酮，氯喹，丙吡啶和酮康唑。确定这种并发症的意义对临床医生以及负责监督药物发现和批准的科学家和监管机构都是有问题的。这是由于对负责磷脂病的机制的有限理解以及缺乏合适的研究模型。溶酶体磷脂酶A2是一种最近发现且表征的磷脂酶，可以水解那些累积继发于药物诱导的磷脂病的磷脂。此外，设计为表达溶酶体磷脂酶A2的不活跃形式的小鼠发展出一种与该疾病的临床表现非常相似的表型。具体而言，这些小鼠在其肺泡巨噬细胞中最突出地发展出溶酶体磷脂积累。当正常的肺泡巨噬细胞暴露于胺碘酮和其他磷脂相关的药物时，体外，溶酶体磷脂酶A2的活性在与磷脂积累的一致过程中抑制。基于这些观察结果，要检验的主要假设是药物诱导的磷脂病是抑制溶酶体磷脂酶A2的结果。该赠款将通过使用新开发的荧光测定法对溶酶体磷脂酶A2活性进行检验，并使用部分或完全缺乏溶酶体磷脂酶A2活性的基因敲除小鼠。该项目还包括有关溶酶体磷脂酶A2蛋白和脂质膜之间静电电荷相互作用的作用的机械研究，该溶液磷脂酶A2蛋白包含酶的底物。最后，通过在细胞系中突变的蛋白质的表达研究，将研究溶酶体磷脂酶A2基因中常见突变与对药物诱导的磷脂病的敏感性之间的关联。如果证明溶酶体磷脂酶A2的抑制是药物诱导的磷脂性病的主要机制，那么这些发现既可能是筛选可能引起这种并发症的药物的基础，也可以作为对这种形式对这种药物毒性具有独特敏感的患者的鉴定。