Peripheral Neuropathy Group, Department of Molecular Genetics, VIB and University of Antwerp, Antwerpen 2610, Belgium.
Neuromuscul Disord. 2012 Aug;22(8):699-711. doi: 10.1016/j.nmd.2012.04.005. Epub 2012 May 15.
Missense mutations in the small heat shock protein HSPB8 cause distal hereditary motor neuropathy (dHMN) and axonal Charcot-Marie-Tooth disease (CMT2L). We previously demonstrated that, despite the ubiquitous expression of HSPB8, motor neurons appear to be predominantly affected by HSPB8 mutations. Here, we studied the effect of mutant HSPB8 in primary fibroblast cultures derived from dHMN patients' skin biopsy. In early passage cultures, we observed in all patients' fibroblasts HSPB8 protein aggregates that were not detected in control cells. After applying heat shock stress on the patients' early passage cultured cells, the protein aggregates coalesced into larger formations, while in control cells a homogenous upregulation of HSPB8 protein expression was seen. We also found a reduction in the mitochondrial membrane potential in the early passage cultures. After three months in culture, the number of cells with aggregates had become indistinguishable from that in controls and the mitochondrial membrane potential had returned to normal. These results emphasize the possible drawbacks of using patients' non-neuronal cells to study neuropathological disease mechanisms.
错义突变导致小型热休克蛋白 HSPB8 引起远端遗传性运动神经病 (dHMN) 和轴索性夏科-马里-图病 (CMT2L)。我们之前的研究表明，尽管 HSPB8 广泛表达，但运动神经元似乎主要受到 HSPB8 突变的影响。在这里，我们研究了源自 dHMN 患者皮肤活检的原代成纤维细胞培养物中突变 HSPB8 的影响。在早期传代培养物中，我们在所有患者的成纤维细胞中观察到 HSPB8 蛋白聚集体，而在对照细胞中未检测到。在对患者的早期传代培养细胞施加热休克应激后，蛋白聚集体聚集成更大的结构，而在对照细胞中观察到 HSPB8 蛋白表达均匀上调。我们还发现早期传代培养物中线粒体膜电位降低。培养三个月后，具有聚集体的细胞数量与对照细胞无明显区别，线粒体膜电位恢复正常。这些结果强调了使用患者的非神经元细胞来研究神经病理学疾病机制可能存在的缺陷。
