DE PEDIATRIC COBRE: MECHANISMS OF CELL DEATH IN SPINAL MUSCULAR ATROPHY

DE PEDIATRIC COBRE：脊髓性肌萎缩症中细胞死亡的机制

• 批准号: 7382175
• 负责人: WENLAN WANG
• 金额: $ 14.23万
• 依托单位: ALFRED I. DU PONT HOSP FOR CHILDREN
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7382175
• 关键词: DE; PEDIATRIC; COBRE; MECHANISMS; CELL

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Spinal muscular atrophy (SMA) is a neuromuscular disease characterized by degeneration of motor neurons and progressive muscle atrophy. The disease is one of the most common genetic causes of infant death. Deletion or mutation(s) of the survival motor neuron gene (SMN1) causes the disease. The SMN protein has been known to function in the assembly of the RNA splicing complex; however, the mechanism(s) by which SMN-deficiency causes cell death in SMA are not clear. Our long-term goal is to understand the mechanism(s) of motor neuron death in SMA and develop a means of prevention. SMN protein has been reported to have some survival-promoting functions in cultured cells. Our studies showed that skin fibroblasts derived from SMA patients are more sensitive to certain death-promoting stimuli than control fibroblasts. We hypothesize that the SMN protein is directly involved in cell survival and that loss of SMN?s survival function results in motor neuron death in SMA. We have used skin fibroblasts derived from SMA patients and PC12 cells as model systems to test this hypothesis. We found that SMA fibroblasts are more prone to camptothecin?induced cell death. Camptothecin treatment results in significant higher caspase-3 activity in SMA fibroblasts, and levels of SMN protein are inversely associated with caspase-3 activity induced by camptothecin. We also demonstrated that transient expression of human SMN in both na¿ve and differentiated PC12 cells decreased camptothecin?activated caspase-3 activity. Upon camptothecin treatments, levels of p53 protein are elevated, suggesting SMN may play its survival function through pathway(s) that are involved in p53. We are currently investigating the effect of SMN on p53 -induced death in PC12 cells. We will further elucidate the role of SMN in motor neuron survival. Finally, we will continue to determine biological pathway(s) of SMN-mediated cell protection.

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心机构，不一定为研究者机构。脊髓性肌萎缩症（spinal muscular atrophy，SMA）是一种以运动神经元变性和进行性肌肉萎缩为特征的神经肌肉疾病。这种疾病是婴儿死亡的最常见遗传原因之一。运动神经元存活基因（SMN 1）的缺失或突变导致疾病。已知SMN蛋白在RNA剪接复合物的组装中起作用;然而，SMN缺陷导致SMA细胞死亡的机制尚不清楚。我们的长期目标是了解SMA中运动神经元死亡的机制并开发预防方法。SMN蛋白已被报道在培养的细胞中具有一些促进存活的功能。我们的研究表明，来自SMA患者的皮肤成纤维细胞比对照成纤维细胞对某些促死刺激更敏感。我们假设SMN蛋白直接参与细胞存活，SMN的丢失？的存活功能导致SMA运动神经元死亡。我们使用来自SMA患者的皮肤成纤维细胞和PC 12细胞作为模型系统来验证这一假设。我们发现SMA成纤维细胞更倾向于喜树碱？诱导细胞死亡。喜树碱处理导致SMA成纤维细胞中caspase-3活性显著升高，SMN蛋白水平与喜树碱诱导的caspase-3活性呈负相关。我们还表明，瞬时表达的人SMN在幼稚和分化的PC 12细胞减少喜树碱？激活caspase-3活性。喜树碱治疗后，p53蛋白水平升高，表明SMN可能通过参与p53的途径发挥其存活功能。我们目前正在研究SMN对p53诱导的PC 12细胞死亡的影响。我们将进一步阐明SMN在运动神经元存活中的作用。最后，我们将继续确定SMN介导的细胞保护的生物学途径。