New Approach to Phospholipidosis Prediction

描述（由申请人提供）：药物安全性是服用药物的人以及制药公司，监管机构和基础研究人员的主要关注点。药物性磷脂病（DIPL）是对阳离子两亲性药物（CADs）的不良反应，导致磷脂过度积累，严重时可导致器官衰竭和死亡。DIPL很普遍；例如，约50%服用普通抗心律失常胺碘酮的患者会出现DIPL，多达17%的患者需要停药。CADs是目前正在测试的批准药物和化合物的重要组成部分，但它们诱导DIPL的潜力目前是通过费力的电子显微镜或质谱方法来评估的。这些方法被FDA判定为不令人满意。人溶酶体磷脂酶A2 （LPLA2， XV PLA2组）是DIPL的核心磷脂加工酶。抑制LPLA2活性可诱导细胞内的磷脂病，LPLA2酶促分析可实现候选化合物的高通量测试。我们建议开发一种简单的荧光生化筛选方法来检测LPLA2的活性，并将其应用于检测CADs诱导磷脂沉积的潜力。我们的具体目标是：i)制备淬灭的荧光LPLA2特异性底物，ii)用重组LPLA2表征这些针对磷脂酶特异性的“智能探针”底物，iii)开发高通量筛选（HTS）试验，iv)使用对照和诱导磷脂病的cad验证该试验。由于毒性和安全性问题，进入临床试验的所有药物中约有三分之一失败，早期发现DIPL将通过在昂贵的临床试验之前确定会导致DIPL的药物来降低医疗保健成本。此外，我们设想该项目最终导致患者筛查LPLA2活性。这种个性化医疗的具体应用将识别出对特定药物易产生DIPL的个体，并指导治疗；从而防止病人受到伤害，提高美国医疗保健的效率

DESCRIPTION (provided by applicant): Drug safety is a major concern for people that taking medicines as well as pharmaceutical companies, regulatory bodies, and basic researchers. Drug induced phospholipidosis (DIPL) is an adverse reaction to cationic amphiphilic drugs (CADs) resulting in excessive phospholipid accumulation, which in serious cases, leads to organ failure and death. DIPL is prevalent; for example, about 50% of patients prescribed the common anti-arrythmic amiodarone will develop DIPL and up to 17% will require withdrawal from the medicine. CADs are a significant fraction of both approved drugs and chemical compounds currently in testing, but their DIPL- inducing potential is currently evaluated by laborious electron microscopy or mass spectrometry methods. These methods have been judged unsatisfactory by the FDA. Human lysosomal phospholipase A2 (LPLA2, group XV PLA2) is a phospholipid processing enzyme central to DIPL. Inhibition of LPLA2 activity induces phospholipidosis in cells, and an LPLA2 enzymatic assay would enable high-throughput testing of candidate compounds. We propose work to develop a simple fluorogenic biochemical screening assay for LPLA2 activity and its application for testing the phospholipidosis-inducing potential of CADs. Our specific aims are: i) prepare quenched fluorogenic LPLA2-specific substrates, ii) characterize these "smart probe" substrates, specific for phospholipases, with recombinant LPLA2, iii) develop a high throughput screening (HTS) assay, and iv) validate the assay using control and phospholipidosis- inducing CADs. With approximately one-third of all drugs entering clinical trials failing because of toxicity and safety concerns, early detection of DIPL would decrease health care costs by identifying drugs that will induce DIPL prior to expensive clinical trials. Further, we envision this project leading eventually to patient screening for LPLA2 activity. This specific application of personalized medicine would identify individuals who are susceptible to DIPL for a given drug and guide treatment; thus preventing patient harm and improving the efficiency of healthcare in the U.S. PUBLIC HEALTH RELEVANCE: Drug safety is a major concern for people taking medicines as well as pharmaceutical groups, regulatory bodies, and basic researchers. We plan to develop and commercialize a biochemical test assessing one common type of drug toxicity called phospholipidosis. Detection of chemical compounds early in the drug- discovery process that cause phospholipidosis would prevent patient harm, decrease costs, and improve the efficiency of healthcare in the U.S.