Pathogenesis/Treatment-Inherited Cholesterol Deficiency

遗传性胆固醇缺乏症的发病机制/治疗

基本信息

批准号：
8625409
负责人：
CEDRIC HOWARD SHACKLETON
金额：
$ 6.91万
依托单位：
CHILDREN'S HOSPITAL & RES CTR AT OAKLAND
依托单位国家：
美国
项目类别：
财政年份：
2006
资助国家：
美国
起止时间：
2006-04-15 至 2016-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8625409
关键词：
7-dehydrocholesterol reductase Adverse effects Aftercare Animals Behavioral Biochemical Biochemical Markers Biochemistry Birth Blood Blood - brain barrier anatomy Brain CMV promoter Cell Count Cells Cerebrospinal Fluid Cholesterol Cholesterol Homeostasis Complex DNA Dehydrocholesterols Detection Development Diagnosis Diagnostic Procedure Disease Dose Dysmorphology Effectiveness Ensure Enzymes Family Fetal Development Fluorescent Antibody Technique Frequencies Gene Delivery Gene Expression Gene Transfer Gene Transfer Techniques Genes Genetic Goals Growth Healthcare Systems Hepatocyte Hereditary Disease Human Inherited Learning Liver Longevity Mass Spectrum Analysis Measures Memory Mental Retardation Messenger RNA Metabolism Methods Microscopic Monitor Mus Mutant Strains Mice Mutation Neuraxis Newborn Infant North America Oxidoreductase Pathogenesis Patients Performance Phenotype Photosensitivity Physiological Plant Roots Preventive Quality of life Reaction Reverse Transcriptase Polymerase Chain Reaction Risk Role Safety Severities Siblings Smith-Lemli-Opitz Syndrome Staining method Stains Sterols Survival Rate Symptoms Technology Testing Therapeutic Time Tissues Vertebral column Viral Vector Weight Gain base behavior test cellular transduction disease characteristic fetal gene therapy gene transfer vector grasp improved in utero killings morris water maze mouse model mutant neuromuscular novel diagnostics pre-clinical prenatal promoter public health relevance research study retinal rods vector

项目摘要

DESCRIPTION (provided by applicant): Smith-Lemli-Opitz syndrome (SLOS) is a dysmorphology and mental retardation disorder lacking adequate therapy options. It is caused by cholesterol deficiency due to inactivity of 7-dehydrocholesterol reductase (DHCR7). Biochemically, it is characterized by low concentrations of cholesterol (C) in blood and tissues and high concentrations of dehydrocholesterol (DHC). Although mutations in the DHCR7 gene have been well described, the pathogenic development of the disease characteristics is not well understood. Among inherited errors of metabolism, SLOS is relatively frequent, and new diagnostic methods aid its prenatal detection. The long-term objective of this proposal is to develop a basis for the treatment of SLOS. For experiments, gene transfer techniques and mouse models that mimic human SLOS will be used. Three Specific Aims are proposed: (Aim 1) Define the limitations of post-natal, systemic gene therapy. The ratio of DHC/C is an indicator of SLOS severity. So far we have improved, but not completely normalized, this ratio by gene therapy. We now seek to enhance the effectiveness of this gene therapy. Our hypothesis is that the number of liver cells able to express the introduced DHCR7 gene is the limiting factor. We shall test this by varying the dose and type of vector carrying a tagged DHCR7 gene, following the extent of transduction by microscopic identification of cells expressing a tagged enzyme (FLAG-DHCR7), and comparing with DHC/C. (Aim 2) Normalize cholesterol in the CNS by treating newborns. Cholesterol metabolism in the CNS must be treated separately because it is isolated from systemic cholesterol by the blood brain barrier. Gene transfer vector will be injected intrathecally into the cerebrospinal fluid of newborn SLOS mice. At various times brains will be analyzed for sterols, DHCR7 DNA and mRNA, and the distribution of cells expressing FLAG-DHCR7. Sustained normalization of DHC/C in brain will prompt behavioral tests to see if learning, memory and neuromuscular performance are improved. (Aim 3) Correct cholesterol levels during fetal development. Here the emphasis is on preventive treatment and establishing when during development irreversible damage occurs. Biochemical markers, dysmorphic features, and physiological indicators (e.g., survival rates, weight gain and photosensitivity) will all be monitored. If there is significant improvement we shall again explore neuromuscular and behavioral performance. For the three types of treatment, systemic, CNS and fetal, long- term consequences, safety and potential adverse effects will also be monitored. Due to the multiple essential roles of cholesterol, SLOS is a complicated and devastating disorder in spite of its relatively simple genetic origin. The frequency of SLOS in North America is estimated at about 1 in 60,000, although many cases are thought to be never diagnosed because of prenatal lethality or mild phenotype. Through the proposed experiments using gene transfer and SLOS mice, we hope to learn more about the timing and biochemistry of disease development and to establish a basis for eventual treatment in humans.

描述（由申请人提供）：Smith-Lemli-Opitz综合征（SLO）是缺乏适当治疗选择的畸形和智力低下的障碍。由于胆固醇缺乏症，由于7-脱氢胆固醇还原酶（DHCR7）引起的胆固醇缺乏症引起。从生化上讲，它的特征是血液和组织中的胆固醇（C）低浓度以及高浓度的脱氢胆固醇（DHC）。尽管已经很好地描述了DHCR7基因中的突变，但疾病特征的致病发育尚不清楚。在代谢的遗传错误中，SLO相对频繁，新的诊断方法有助于其产前检测。该提案的长期目标是为治疗SLO的治疗基础。对于实验，将使用模仿人类SLO的基因转移技术和小鼠模型。提出了三个具体目的：（目标1）定义产后，全身基因治疗的局限性。 DHC/C的比率是SLOS严重程度的指标。到目前为止，我们已经通过基因治疗提高了这种比率，但还没有完全归一化。我们现在寻求提高这种基因疗法的有效性。我们的假设是能够表达引入的DHCR7基因的肝细胞数量是限制因素。我们应根据微观鉴定表达标记酶（FLAG-DHCR7）的细胞的转导程度，并与DHC/C进行比较，从而改变带有标记的DHCR7基因的载体的剂量和类型。（AIM 2）通过治疗新生儿将中枢神经系统中的胆固醇归一化。中枢神经系统中的胆固醇代谢必须分别治疗，因为血液脑屏障与全身胆固醇分离。基因转移载体将静定地注入新生儿SLOS小鼠的脑脊液中。在不同时间，将分析大脑的固醇，DHCR7 DNA和mRNA，以及表达FLAG-DHCR7的细胞的分布。大脑中DHC/C的持续归一化将促使行为测试，以查看学习，记忆和神经肌肉表现是否得到改善。（AIM 3）在胎儿发育过程中正确胆固醇水平。在这里，重点是预防治疗和确定在发育中发生不可逆损害时。将监测生化标记，畸形特征和生理指标（例如，生存率，体重增加和光敏性）。如果有显着改善，我们将再次探索神经肌肉和行为表现。对于三种类型的治疗，全身，中枢神经系统和胎儿，还将监测长期后果，安全性和潜在的不利影响。由于胆固醇的多重作用，尽管其相对简单的遗传起源，但SLO是一种复杂而毁灭性的疾病。北美SLO的频率估计为60,000分之一，尽管由于产前致死性或轻度表型，人们认为许多病例被认为从未被诊断出。通过提出的使用基因转移和SLOS小鼠的实验，我们希望更多地了解有关疾病发展的时间和生物化学的更多信息，并为人类最终治疗的基础建立基础。