Gedunin Degrades Aggregates of Mutant Huntingtin Protein and Intranuclear Inclusions via the Proteasomal Pathway in Neurons and Fibroblasts from Patients with Huntington’s Disease

Huntington's disease(HD) is a deadly neurodegenerative disease with abnormal expansion of CAG repeats in the huntingtin gene. Mutant Huntingtin protein(m HTT) forms abnormal aggregates and intranuclear inclusions in specific neurons, resulting in cell death. Here,we tested the ability of a natural heat-shock protein 90 inhibitor, Gedunin, to degrade transfected m HTT in Neuro-2 a cells and endogenous m HTT aggregates and intranuclear inclusions in both fibroblasts from HD patients and neurons derived from induced pluripotent stem cells from patients. Our data showed that Gedunin treatment degraded transfected m HTT in Neuro-2 a cells, endogenous m HTT aggregates and intranuclear inclusions in fibroblasts from HD patients, and in neurons derived from induced pluripotent stem cells from patients in a dose-and time-dependent manner, and its activity depended on the proteasomal pathway rather than the autophagy route. These findings also showed that although Gedunin degraded abnormal m HTT aggregates and intranuclear inclusions in cells from HD patient, it did not affect normal cells, thus providing a new perspective for using Gedunin to treat HD.

纹状体内注射AAV9-82Q诱导亨廷顿病小鼠模型构建及评价

目的通过向纹状体内注射携带82个CAG重复序列的腺相关病毒(AAV)载体9型(AAV9-82Q)构建亨廷顿病(HD)小鼠模型并对其进行评价。方法将50只C57BL/6小鼠随机分入AAV9-82Q组(n=19,注射AAV9-82Q)、AAV9-GFP组(n=19,注射空白对照病毒AAV9-GFP)及正常组(n=12,不做任何处理)。造模后采用转棒实验和平衡木实验评估小鼠的运动功能,Y迷宫实验评估认知功能,免疫荧光染色检测纹状体mHtt和NeuN表达。结果从造模后4周开始,AAV9-82Q组小鼠从转棒上掉落的平均潜伏期短于正常组、AAV9-GFP组,差异有统计学意义(P<0.05)。在造模后18~24周,AAV9-82Q组小鼠通过平衡木的时间长于正常组、AAV9-GFP组,差异有统计学意义(P<0.05)。3组小鼠的自发交替转换率比较,差异无统计学意义(P>0.05)。AAV9-82Q组小鼠纹状体内可见明显的mHtt表达,但在正常组、AAV9-GFP组中未检测到mHtt;与正常组、AAV9-GFP组比较,AAV9-82Q组小鼠纹状体内NeuN表达未见明显减少。结论AAV9-82Q注射使小鼠出现运动障碍,纹状体过表达mHtt,成功构建HD小鼠模型。