Huntington Disease (HD) is a late-onset autosomal neurodegenerative disease characterized by the aggregations of mutant Huntingtin proteins (mHTT). A glutamine stretch (PolyQ) at the N-terminal of the Huntingtin protein is generated by the abnormal expansion of CAG trinucleotide repeats in exon 1 of the HTT gene. While the resulting polyQ aggregates are the predominate feature of HD, the intercellular spread of the expanded protein and the effect upon this transfer inside healthy cells have not yet fully understood. Here, we have employed the phasor Fluorescence Lifetime Imaging Microscopy (FLIM) method to measure NADH fluorescence lifetime change after the internalization of the PolyQ protein. Based on our analysis, we have found a significant decrease in the fraction of bound NADH in both cytoplasmic and nucleus regions when cells are co-cultured or when healthy cells uptake the supernatant containing polyQ proteins and aggregates. Overall, our FLIM study combined with confocal fluorescence imaging visualizes the absorption of the mutant Htt protein aggregates which results in a distinct NADH fluorescence lifetime between control cells and acceptor cells. These studies show, for the first time, the influence of how neighboring cells expressing the expanded Htt protein can regulate energy metabolism in healthy cells.

亨廷顿病 (HD) 是一种迟发性常染色体神经退行性疾病，其特征是突变亨廷顿蛋白 (mHTT) 的聚集。亨廷顿蛋白 N 末端的谷氨酰胺链 (PolyQ) 是由 HTT 基因外显子 1 中 CAG 三核苷酸重复序列的异常扩增产生的。虽然由此产生的 polyQ 聚集体是 HD 的主要特征，但扩展蛋白质的细胞间扩散以及对健康细胞内这种转移的影响尚未完全了解。在这里，我们采用相量荧光寿命成像显微镜 (FLIM) 方法来测量 PolyQ 蛋白内化后的 NADH 荧光寿命变化。根据我们的分析，我们发现，当细胞共培养或健康细胞摄取含有 polyQ 蛋白和聚集体的上清液时，细胞质和细胞核区域结合 NADH 的比例显着降低。总体而言，我们的 FLIM 研究与共聚焦荧光成像相结合，可视化了突变 Htt 蛋白聚集体的吸收，从而导致对照细胞和受体细胞之间的不同 NADH 荧光寿命。这些研究首次表明，表达扩展的 Htt 蛋白的邻近细胞如何调节健康细胞的能量代谢。我们的 FLIM 研究与共聚焦荧光成像相结合，可视化了突变 Htt 蛋白聚集体的吸收，从而导致对照细胞和受体细胞之间的不同 NADH 荧光寿命。这些研究首次表明，表达扩展的 Htt 蛋白的邻近细胞如何调节健康细胞的能量代谢。我们的 FLIM 研究与共聚焦荧光成像相结合，可视化了突变 Htt 蛋白聚集体的吸收，从而导致对照细胞和受体细胞之间的不同 NADH 荧光寿命。这些研究首次表明，表达扩展的 Htt 蛋白的邻近细胞如何调节健康细胞的能量代谢。