Department of Laboratory Medicine and Pathobiology, The University of Toronto, Toronto, Ontario, Canada.
J Neurochem. 2010 Aug;114(4):1177-92. doi: 10.1111/j.1471-4159.2010.06846.x. Epub 2010 Jun 1.
Peripherin is a type III intermediate filament protein that is up-regulated during neuronal injury and is a major component of pathological inclusions found within degenerating motor neurons of patients with amyotrophic lateral sclerosis (ALS). The relationship between these inclusions and their protein constituents remains largely unknown. We have previously shown that peripherin expression is characterized by tissue-specific, intra-isoform associations that contribute to filament structure; changes to the normal isoform expression pattern is associated with malformed filaments and intracellular inclusions. Here, we profile peripherin isoform expression and ratio changes in traumatic neuronal injury, transgenic mouse models of motor neuron disease, and ALS. Extensive western blot analyses of Triton X-100 soluble and insoluble fractions of neuronal tissue from these conditions revealed significant changes in peripherin isoform content which could be differentiated by electrophoretic banding patterns to produce distinct peripherin biochemical signatures. Significantly, we found that the pattern of peripherin expression in ALS most closely approximates that of peripherin over-expressing mice, but differs with regard to inter-individual variations in isoform-specific expression. Overall, these results provide important insights into complex post-transcriptional processes that may underlie a continuum between peripherin-mediated neuronal repair and its role in the pathogenesis of motor neuron disease.
外周蛋白是一种 III 型中间丝蛋白，在神经元损伤时上调，是肌萎缩侧索硬化症（ALS）患者变性运动神经元中发现的病理性包含物的主要成分。这些包含物及其蛋白成分之间的关系在很大程度上仍然未知。我们之前已经表明，外周蛋白的表达特征是组织特异性的同种型内关联，有助于纤维丝结构；正常同种型表达模式的改变与畸形纤维丝和细胞内包含物有关。在这里，我们对创伤性神经元损伤、运动神经元疾病的转基因小鼠模型和 ALS 中的外周蛋白同种型表达和比例变化进行了分析。对这些条件下神经元组织的 Triton X-100 可溶性和不溶性部分进行了广泛的 Western blot 分析，结果显示外周蛋白同种型含量发生了显著变化，通过电泳带型可以将其区分开来，从而产生独特的外周蛋白生化特征。重要的是，我们发现 ALS 中的外周蛋白表达模式与过表达小鼠的外周蛋白表达模式最为接近，但在同种型特异性表达的个体间差异方面有所不同。总体而言，这些结果提供了对外周蛋白介导的神经元修复及其在运动神经元疾病发病机制中的作用之间连续体的复杂转录后过程的重要见解。
