Generation of a floxed CST mouse

描述(申请人提供)：硫脂是一种在少突胶质细胞和神经元中发现的鞘磷脂，在多发性硬化症(MS)患者和阿尔茨海默病(AD)患者的中枢神经系统中显著和特异地减少。在AD和MS中，硫脂的耗竭发生在疾病过程的非常早期，因为极轻度痴呆的AD患者和脱髓鞘前的MS患者的硫脂水平降低。虽然早期耗竭与促进疾病进展一致，但目前几乎没有证据表明硫脂耗竭与AD或MS相关的病理机制有关。然而，使用在所有类型的细胞中以及在其整个生命周期中不能合成硫脂的小鼠，我的实验室证明(见初步结果)，缺乏硫脂会导致(1)结构紊乱、蛋白膜域丢失和髓鞘不稳定，所有这些在MS中都可以看到；(2)在神经元变性、神经纤维缠结的形成和突触完整性受损方面，所有这些都在AD中可以观察到。基于这些发现，我认为硫脂的枯竭在观察到的AD和MS的病理后果中发挥了作用。为了检验这一假设，我们将产生一只小鼠，其编码脑苷磺基转移酶(CST)的基因的一部分带有loxP位点，CST是催化硫脂合成的最后一步的酶。利用这种“有牙线的”小鼠将使我们能够以特定的年龄和细胞类型的方式消耗硫脂。在这只“有牙线”的CST小鼠出生后，我们将采用多种方法的组合来确认体内重组酶的正确切除以及不能合成硫脂。硫脂特异性耗尽的细胞类型和年龄的“丛生”小鼠的产生和分析对于我们了解硫脂在AD和MS的发病机制中所起的作用是极其重要的一步。 公共卫生相关性：硫脂在阿尔茨海默病和多发性硬化症中显著和特别地耗尽；然而，这种耗竭的病理后果尚不清楚。在这里，我们将产生一只小鼠，它将提供特定细胞类型和特定年龄的这种显著脂质的消耗。这种新型小鼠的产生和分析将为确定硫脂耗竭的病理后果提供极其重要的一步，并将极大地促进我们对硫脂在AD和MS的发病机制中所起作用的理解。

DESCRIPTION (provided by applicant): Sulfatide, a sphingolipid found in oligodendrocytes and neurons, is significantly and specifically reduced in the CNS of patients with multiple sclerosis (MS) and also of patients with Alzheimer's disease (AD). In both AD and MS the depletion of sulfatide occurs very early in the disease process as sulfatide levels are reduced in AD patients with very mild dementia and in patients with MS prior to demyelination. Although early depletion is consistent with facilitating disease progression, there is currently little evidence that ties sulfatide depletion to pathologic mechanisms associated with either AD or MS. However, using mice that are incapable of synthesizing sulfatide in all cell types and throughout their entire life span, my lab demonstrates (see Preliminary Results) that the absence of sulfatide results (1) in structurally disrupted paranodes, loss of protein membrane domains and myelin instability all of which are seen in MS and (2) in neuronal degeneration, formation of neurofibrillary tangles and compromised synaptic integrity all of which are observed in AD. Based on these findings, I propose that the depletion of sulfatide plays a role in the pathologic consequences observed in both AD and MS. To test this hypothesis we will generate a mouse with loxP sites flanking portions of the gene that encodes cerebroside sulfotransferase (CST), the enzyme that catalyzes the final step of sulfatide synthesis. Exploitation of this "floxed" mouse will enable us to deplete sulfatide in an age and cell type specific manner. Upon generation of this "floxed" CST mouse, we will employ a combination of approaches to confirm proper in vivo recombinase excision and the inability to synthesize sulfatide. Generation and analysis of the "floxed" mouse that is cell type and age specifically depleted in sulfatide is an extremely important step in the advancement of our understanding of the role that sulfatide plays in the pathogenesis of both AD and MS. PUBLIC HEALTH RELEVANCE: Sulfatide is significantly and specifically depleted in Alzheimer's disease and multiple sclerosis; however, the pathologic consequences of this depletion are not known. Here, we will generate a mouse that will provide cell type specific and age specific depletion of this prominent lipid. Generation and analysis of this novel mouse will provide an extremely important step in determining the pathologic consequences of sulfatide depletion and will significantly enhance the advancement of our understanding of the role that sulfatide plays in the pathogenesis of both AD and MS.