Effect of early psychosine accumulation in Krabbe Disease on CNS progenitor cells

描述(申请人提供)：在初级中枢神经系统(CNS)祖细胞群体中，尤其是那些负责正常髓鞘形成的少突胶质细胞谱系中，还没有研究Krabbe病早期精神药物积聚的分子效应。当早发性Krabbe病患者出现神经系统症状时，中枢神经系统的损害可能是无法修复的，这是因为在关键的发育期，异常水平的精神药物早期积累及其对易受伤害的祖细胞群体的影响。初步数据表明，生理上相关浓度的精神病素正在激活原代少突胶质细胞/2型星形胶质细胞前体细胞(O-2A/OPC)中先前描述的氧化还原/Fyn/c-Cbl途径。该途径在正常的O-2A/OPC增殖和迁移中起重要作用。对这一途径的进一步研究将更好地确定精神药物毒性的细胞和分子机制。此外，将对NINDS II库中FDA批准的药物进行筛选，以确定哪些药物可以改善或加剧精神病药的毒性作用。将使用自动贴壁细胞细胞仪系统进行快速体外筛选。候选药物将在早期发病的Krabbe病小鼠模型Twitcher小鼠身上进一步进行体内测试。发育效果将通过大脑和脊髓切片的免疫组织化学染色和Western印迹分析来确定。行为和运动功能测试、寿命和症状严重程度将作为药物治疗的功能读数进行。其目标是通过药物治疗干预保护早发性Krabbe患者的早期中枢神经系统发育免受内源性精神药物积聚的影响，最终在与遗传和酶替代疗法结合使用时能够提高疗效。 与公共卫生相关：Krabbe病是一种衰弱的神经系统遗传性疾病，在美国每100,000名活产儿中就有1人受到影响(然而，常见突变的携带率估计为每125人中有1人)，并导致严重的神经变性、脱髓鞘和死亡。目前尚无治愈方法，目前的治疗干预措施对病情较重的早期患者几乎没有什么益处。 发病(婴儿)形式的疾病。我的研究旨在确定由于正常祖细胞生物学改变而导致的早期神经系统发育异常，并筛选FDA批准的改善或加剧这些影响的药物，以促进多种治疗方法，为目前没有有效治疗选择的患者提供更长的时间和更高的生活质量。

DESCRIPTION (provided by applicant): The molecular effect of early psychosine accumulation in Krabbe disease has not been studied in primary central nervous system (CNS) progenitor cell populations, specifically those of the oligodendroglial lineage responsible for proper myelination. By the time early onset Krabbe disease patients have presented with neurological symptoms, damage to the CNS may be irreparable due to early accumulation of abnormal levels of psychosine and its effect on vulnerable progenitor populations during critical developmental periods. Preliminary data suggests that physiologically relevant concentrations of psychosine are activating the previously described [13] redox/Fyn/c-Cbl pathway in primary oligodendrocyte/type-2 astrocyte progenitor cells (O-2A/OPCs). This pathway plays an important role in normal O-2A/OPC proliferation and migration. Further investigations on this pathway will better define cellular and molecular mechanisms of psychosine toxicity. Moreover, FDA-approved drugs in the NINDS II library will be screened to identify those that either ameliorate or exacerbate the toxic effects of psychosine. Rapid in vitro screening will be conducted using an automated adherent cell cytometry system. Candidate drugs will be further tested in vivo in the early onset Krabbe disease mouse model, the twitcher mouse. Developmental effects will be identified through immunohistochemical staining of brain and spinal cord sections and Western blot analysis. Behavioral and motor function tests, lifespan and symptom severity will be conducted as functional readouts of drug treatment. The goal is to protect early CNS development from effects of endogenous psychosine accumulation in early onset Krabbe patients through drug treatment intervention, ultimately to enable increased efficacy when used in combination with genetic and enzymatic replacement therapies. PUBLIC HEALTH RELEVANCE: Krabbe Disease is a debilitating genetic disorder of the nervous system that affects 1 in 100,000 live births in the United States (however the carrier rate for common mutations is estimated at 1 in 125 individuals) and results in severe neurological degeneration, demyelination, and death. At present there is no cure, and current therapeutic interventions have little beneficial effect in patients that have the more severe early onset (infantile) form of the disease. My research aims to identify abnormalities in early nervous system development due to alterations in normal progenitor cell biology and to screen FDA-approved drugs that ameliorate or exacerbate these effects to contribute to a multi-therapeutic approach that affords increased length and quality of life to patients that currently have no efficacious treatment options.