Mouse models of Pik3ca brain overgrowth disorders

Pik3ca 大脑过度生长障碍的小鼠模型

基本信息

批准号：
9331300
负责人：
Kathleen Joyce Millen
金额：
$ 55.91万
依托单位：
SEATTLE CHILDREN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-04-01 至 2022-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9331300
关键词：
AKT Signaling Pathway Acute Adult Alleles Antiepileptic Agents Antineoplastic Agents Apoptosis Autistic Disorder Automobile Driving Biological Assay Biological Models Blood capillaries Brain Brain Diseases Brain Pathology Cell Size Cell division Child Childhood Chimera organism Cortical Dysplasia Cortical Malformation Data Defect Development Diffuse Dysplasia Disease Dysplasia Electroporation Embryo Enzymes Epidermal nevus Epilepsy Excision Exhibits FRAP1 gene Gene Mutation Germ-Line Mutation Hand Hippocampus (Brain)Hot Spot Hour Human Individual Injectable Intellectual functioning disability Intractable Epilepsy Lead Malignant Neoplasms Megalencephaly Modeling Molecular Mosaicism Mus Mutant Strains Mice Mutation Neurons Operative Surgical Procedures PIK3CA gene Pathogenesis Pathway interactions Patients Pharmacology Pharmacotherapy Phenotype Phosphatidylinositols Phosphotransferases Proteomics Proto-Oncogene Proteins c-akt Reporting Reproducibility Resistance Role Seborrheic keratosis Seizures Series Severities Side Signal Pathway Signal Transduction Sirolimus Stem cells Structural defect Syndrome Technology Testing base blastocyst brain overgrowth cancer type capillary clinically relevant critical developmental period developmental disease embryonic stem cell experimental study gain of function gain of function mutation genetic approach in utero inhibitor/antagonist mTOR Inhibitor malformation migration mouse model mutant nerve stem cell novel therapeutics pre-clinical standard of care

项目摘要

PROJECT SUMMARY This proposal outlines a comprehensive series of experiments to assess the basis of overgrowth phenotypes associated with gain of function mutations in PIK3CA, using the mouse as a model system. Although well studied in cancer, recent data has revealed a role for PIK3CA mutation in several developmental disorders including MCAP, DMEG, CLOVES syndrome, epidermal nevi and seborrheic keratosis. Here will assess the developmental and signaling pathway disruptions caused by 3 different Pik3ca gain of function mutations, with particular emphasis on the developing brain. To date, all reported PIK3CA mutations are postzygotic or mosaic rather than germline mutations. Accordingly, we hypothesize that PIK3CA phenotypes correlate with both the severity of the mutation and level (and distribution) of mosaicism. To test this and other hypotheses, we will use standard conditional genetic approaches to express 3 patient-related Pik3ca gof mutations in embryonic CNS neuronal progenitors and their descendants. We will then generate ES cell chimeras, injecting ES cells constitutively expressing the same mutations into wild-type blastocysts to assess phenotype-mosaicism relationships both within the brain and throughout the entire body. We also propose to use in utero electroporation technology to more specifically target mosaic expression to the developing brain. Our studies will assess the developmental pathogenesis of brain pathology and characterize the associated epilepsy, a pressing clinically relevant phenotype. Finally, we will use pharmacological approaches to assess the underlying mechanisms driving acutely Pik3ca-dependent seizures in post-natal mice. These assays represent the first step toward developing molecularly rational epilepsy therapy in PIK3CA segmental brain overgrowth syndrome patients.

项目概要该提案概述了评估过度生长表型基础的一系列综合实验与 PIK3CA 功能突变相关，使用小鼠作为模型系统。虽然很好在癌症研究中，最近的数据揭示了 PIK3CA 突变在多种发育障碍中的作用包括MCAP、DMEG、CLOVES综合征、表皮痣和脂溢性角化病。这里将评估由 3 种不同的 Pik3ca 功能增益突变引起的发育和信号通路中断，特别强调大脑的发育。迄今为止，所有报道的 PIK3CA 突变都是合子后突变或嵌合体突变而不是种系突变。因此，我们假设 PIK3CA 表型与突变的严重程度和嵌合体的水平（和分布）。为了检验这个假设和其他假设，我们将使用标准条件遗传方法在胚胎中表达 3 个与患者相关的 Pik3ca gof 突变 CNS 神经元祖细胞及其后代。然后我们将生成 ES 细胞嵌合体，注射 ES 细胞在野生型囊胚中组成型表达相同的突变以评估表型镶嵌现象大脑内部和整个身体的关系。我们还建议在子宫内使用电穿孔技术可以更具体地将马赛克表达靶向发育中的大脑。我们的研究将评估脑病理学的发育发病机制并描述相关癫痫的特征，紧迫的临床相关表型。最后，我们将使用药理学方法来评估驱动产后小鼠严重依赖 Pik3ca 癫痫发作的潜在机制。这些测定代表开发针对 PIK3CA 节段性脑过度生长的分子理性癫痫疗法的第一步综合症患者。