Examining the role of the Lissencephaly protein, Lis1, in dynein-based transport

检查无脑畸形蛋白 Lis1 在基于动力蛋白的运输中的作用

• 批准号: 8618957
• 负责人: DEANNA S SMITH
• 金额: $ 29.53万
• 依托单位: UNIVERSITY OF SOUTH CAROLINA AT COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-01-01 至 2017-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8618957
• 关键词: APC gene; Adult; Adverse effects; Afferent Neurons; Agonist; Amyotrophic Lateral Sclerosis; Animal Model; Animals; Axon; Axonal Transport; Behavioral; Binding; Biochemical; Brain; Cell Line; Cerebral cortex; Clinical; Colon Carcinoma; Complex; Cyclin-Dependent Kinase 5; Defect; Development; Disease; Dissection; Dynein ATPase; Embryo; Event; Gene Mutation; Genes; Genetic; Glycogen Synthase Kinases; Human; Huntington Disease; In Vitro; Insulin; Intervention; Knockout Mice; LIS1 protein; Late-Onset Disorder; Life; Link; Lithium; Lithium Chloride; Lysosomes; Mammals; Microtubule-Associated Proteins; Microtubules; Mind; Mitochondria; Molecular; Monitor; Mood Disorders; Moods; Motor; Mus; Mutation; Nerve; Neurologic; Neurologic Dysfunctions; Neuronal Dysfunction; Neurons; Non-Insulin-Dependent Diabetes Mellitus; Nuclear Hormone Receptors; Organelles; Pathway interactions; Peroxisome Proliferator-Activated Receptors; Pharmaceutical Preparations; Phosphorylation; Phosphotransferases; Plus End of the Microtubule; Positioning Attribute; Process; Proteins; Rattus; Regulation; Role; Schizophrenia; Speed; Symptoms; Syndrome; Takeda brand of pioglitazone hydrochloride; Testing; Therapeutic; Work; base; brain malformation; cellular imaging; design; genetic manipulation; inhibitor/antagonist; insulin sensitizing drugs; interest; late disease onset; lissencephaly; mutant; nervous system disorder; novel; overexpression; prevent; research study; response; retrograde transport; rosiglitazone; synaptic function

DESCRIPTION (provided by applicant): Lissencephaly, an autosomal dominant brain malformation caused by mutations in the LIS1 gene, was the first neurological disorder linked directly to cytoplasmic dynein function. This discovery led the way for molecular dissection of events regulating development of the mammalian cerebral cortex. Lis1 and a binding partner, Nudel, bind directly to dynein and regulate its activity. This interaction has been studied almost exclusively in the context of brain development. More recently, gene products associated with later-onset disorders such as schizophrenia, amyotrophic lateral sclerosis (ALS), Perry Syndrome, and Huntington's disease (HD) have been shown to interact directly with dynein pathways. The discovery of an important role for Lis1 and Nudel in regulating dynein-dependent axonal transport in cultured adult rat sensory neurons has led to the hypothesis that perturbing this regulatory network will cause neuronal dysfunction in mice. To test this, the pathological consequences of disrupting Lis1 in post-developmentally will be determined using floxed-Lis1 and Cre strains. Histological, biochemical, and behavioral studies will be carried out to determine if depletion of Lis1 post- developmentally causes neurological dysfunction. Because this could exacerbate disease symptoms in lissencephaly and other neurological disorders, these studies may provide a feasible target for clinical intervention by drugs. Possible candidates are the PPAR3 agonists Avandia and Actos, insulin sensitizers normally used to treat type 2 diabetes. Recent studies indicate that these drugs stimulate dynein in several cell lines. This is blocked by mutations in APC, a microtubule plus end associated protein typically linked to colon cancer. APC has also been found to have critical roles in neurons, influencing both synaptic function and axonal transport. Notably, the dynein response to PPAR3 agonists requires PI3K activity and is mimicked by lithium, a potent Gsk32 inhibitor used to treat mood disorders. Moreover, dynein is a target of Gsk32 in vitro and its phosphorylation results in a 5-fold increase in coimmunoprecipitation of an APC fragment suggesting that inhibition of the kinase could impact dynein interactions. Dynein distribution in sensory neurons is altered in response to PPAR3 agonists, leading to the hypothesis that PPAR3 pathways contribute to regulation of dynein-dependent axonal transport in adult neurons. This will be tested by determining the effect of pharmacological and genetic manipulation of PPAR3/Gsk32/APC pathways on organelle transport in adult rat DRG neurons and determining if crosstalk occurs between Lis1 and PPAR3 pathways.

描述（由申请人提供）：无脑畸形是一种由LIS 1基因突变引起的常染色体显性脑畸形，是第一种与细胞质动力蛋白功能直接相关的神经系统疾病。这一发现为哺乳动物大脑皮层发育调控事件的分子解剖开辟了道路。Lis 1和结合伴侣Nudel直接与动力蛋白结合并调节其活性。这种相互作用几乎完全是在大脑发育的背景下研究的。最近，与迟发性疾病如精神分裂症、肌萎缩性侧索硬化症（ALS）、佩里综合征和亨廷顿氏病（HD）相关的基因产物已被证明与动力蛋白途径直接相互作用。Lis 1和Nudel在培养的成年大鼠感觉神经元中调节动力蛋白依赖性轴突运输中的重要作用的发现导致了这样的假设，即扰乱该调节网络将导致小鼠神经元功能障碍。为了测试这一点，将使用经鉴定的Lis 1和Cre菌株来确定在发育后破坏Lis 1的病理后果。将进行组织学、生物化学和行为研究，以确定发育后Lis 1的缺失是否会导致神经功能障碍。由于这可能会加剧无脑畸形和其他神经系统疾病的疾病症状，这些研究可能会为药物的临床干预提供一个可行的目标。可能的候选者是PPAR 3激动剂文迪雅和Actos，通常用于治疗2型糖尿病的胰岛素增敏剂。最近的研究表明，这些药物刺激动力蛋白在几个细胞系。这被APC突变所阻断，APC是一种微管加末端相关蛋白，通常与结肠癌相关。APC也被发现在神经元中具有关键作用，影响突触功能和轴突运输。值得注意的是，动力蛋白对PPAR 3激动剂的反应需要PI 3 K活性，并且被锂（一种用于治疗情绪障碍的有效Gsk 32抑制剂）模拟。此外，动力蛋白是Gsk 32在体外的一个目标，其磷酸化的APC片段的免疫共沉淀的结果增加了5倍，这表明抑制激酶可能会影响动力蛋白的相互作用。感觉神经元中的动力蛋白分布响应于PPAR 3激动剂而改变，导致PPAR 3途径有助于调节成年神经元中的动力蛋白依赖性轴突运输的假设。这将通过确定PPAR 3/Gsk 32/APC途径的药理学和遗传操作对成年大鼠DRG神经元中细胞器转运的影响并确定Lis 1和PPAR 3途径之间是否发生串扰来进行测试。