Department of Neurology, The Fourth Hospital of Harbin Medical University, 150001, China; Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, United States of America.
Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, United States of America.
Neurobiol Dis. 2024 Jun 1;195:106502. doi: 10.1016/j.nbd.2024.106502. Epub 2024 Apr 10.
Synaptic changes are early manifestations of neuronal dysfunction in Huntington's disease (HD). However, the mechanisms by which mutant HTT protein impacts synaptogenesis and function are not well understood. Herein we explored HD pathogenesis in the BACHD mouse model by examining synaptogenesis and function in long term primary cortical cultures. At DIV14 (days in vitro), BACHD cortical neurons showed no difference from WT neurons in synaptogenesis as revealed by colocalization of a pre-synaptic (Synapsin I) and a post-synaptic (PSD95) marker. From DIV21 to DIV35, BACHD neurons showed progressively reduced colocalization of Synapsin I and PSD95 relative to WT neurons. The deficits were effectively rescued by treatment of BACHD neurons with BDNF. The recombinant apical domain of CCT1 (ApiCCT1) yielded a partial rescuing effect. BACHD neurons also showed culture age-related significant functional deficits as revealed by multielectrode arrays (MEAs). These deficits were prevented by BDNF, whereas ApiCCT1 showed a less potent effect. These findings are evidence that deficits in BACHD synapse and function can be replicated in vitro and that BDNF or a TRiC-inspired reagent can potentially be protective against these changes in BACHD neurons. Our findings support the use of cellular models to further explicate HD pathogenesis and potential treatments.
突触变化是亨廷顿病（HD）神经元功能障碍的早期表现。然而，突变 HTT 蛋白影响突触发生和功能的机制尚不清楚。在此，我们通过检查长期原代皮质培养物中的突触发生和功能，探讨了 BACHD 小鼠模型中的 HD 发病机制。在 DIV14（体外天数），与 WT 神经元相比，BACHD 皮质神经元在突触发生方面没有差异，这是通过前突触（Synapsin I）和后突触（PSD95）标记物的共定位来揭示的。从 DIV21 到 DIV35，与 WT 神经元相比，BACHD 神经元的 Synapsin I 和 PSD95 共定位逐渐减少。BDNF 处理有效挽救了 BACHD 神经元的缺陷。重组 CCT1 的顶端结构域（ApiCCT1）产生部分挽救效果。BACHD 神经元还表现出与培养年龄相关的显著功能缺陷，如多电极阵列（MEA）所示。BDNF 可预防这些缺陷，而 ApiCCT1 的效果较弱。这些发现证明了 BACHD 突触和功能的缺陷可以在体外复制，BDNF 或受 TRiC 启发的试剂可能对 BACHD 神经元的这些变化具有保护作用。我们的研究结果支持使用细胞模型进一步阐明 HD 的发病机制和潜在的治疗方法。
