Generation of a floxed CST mouse

描述（由申请人提供）：硫苷脂是一种在少突胶质细胞和神经元中发现的鞘脂，在多发性硬化症（MS）患者和阿尔茨海默病（AD）患者的CNS中显著且特异性降低。在AD和MS两者中，硫苷脂的消耗在疾病过程的非常早期发生，因为在具有非常轻度痴呆的AD患者和在脱髓鞘之前的MS患者中，硫苷脂水平降低。尽管早期消耗与促进疾病进展一致，但目前几乎没有证据表明硫苷脂消耗与AD或MS相关的病理机制有关。然而，使用在所有细胞类型中和在其整个生命周期中都不能合成硫苷脂的小鼠，我的实验室证明了（见初步结果），硫苷脂的缺乏导致（1）结构破坏的副阳极，蛋白质膜结构域的损失和髓磷脂不稳定性，所有这些都在MS中观察到，和（2）神经元变性、神经元缠结的形成和受损的突触完整性，所有这些都在AD中观察到。基于这些研究结果，我建议，消耗的硫苷脂起着一定的作用，在AD和MS中观察到的病理后果。为了验证这一假设，我们将产生一个小鼠与loxP位点侧翼部分的基因编码的糖苷磺基转移酶（CST），催化的最后一步硫苷脂合成的酶。利用这种“floxed”小鼠将使我们能够以特定年龄和细胞类型的方式消耗硫苷脂。在产生这种“floxed”CST小鼠后，我们将采用多种方法的组合来确认适当的体内重组酶切除和不能合成硫苷脂。“floxed”小鼠的产生和分析是细胞类型和年龄特异性地耗尽硫苷脂，这是我们理解硫苷脂在AD和MS发病机制中所起作用的一个极其重要的步骤。 公共卫生相关性：在阿尔茨海默病和多发性硬化症中，硫脂显著且特异性地消耗;然而，这种消耗的病理后果尚不清楚。在这里，我们将产生一种小鼠，其将提供这种突出脂质的细胞类型特异性和年龄特异性消耗。这种新型小鼠的产生和分析将为确定硫苷脂耗竭的病理后果提供极其重要的一步，并将显著提高我们对硫苷脂在AD和MS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.