Andjus Pavle, Stamenković Stefan, Dučić Tanja
Faculty of Biology, Center for Laser Microscopy-CLM, University of Belgrade, Studentski trg 16, Belgrade, 11000, Serbia.
CELLS-ALBA, Carrer de la Llum 2-26, Cerdanyola del Vallès, 08290, Barcelona, Spain.
Eur Biophys J. 2019 Jul;48(5):475-484. doi: 10.1007/s00249-019-01380-5. Epub 2019 Jun 26.
Pathological mechanisms in amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease, are still poorly understood. One subset of familial ALS cases is caused by mutations in the metallo-enzyme copper-zinc superoxide dismutase (SOD1), increasing the susceptibility of the SOD1 protein to form insoluble intracellular aggregates. Here, we employed synchrotron radiation-based Fourier transform infrared spectroscopy and microscopy to investigate brainstem cross-sections from the transgenic hSOD1 G93A rat model of ALS that overexpresses human-mutated SOD1. We compared the biomacromolecular organic composition in brainstem tissue cross-sections of ALS rats and their non-transgenic littermates (NTg). We demonstrate that the proteins and especially their antiparallel β-sheet structure significantly differed in all three regions: the facial nucleus (FN), the gigantocellular reticular nucleus (GRN) and the trigeminal motor nucleus (TMN) in the brainstem tissue of ALS rats. The protein levels varied between different brainstem areas, with the highest concentration observed in the region of the FN in the brainstem tissue of NTg animals. Furthermore, the concentration of lipids and esters was significantly decreased in the TMN and FN of ALS animals. A similar pattern was detected for choline and phosphate assigned to nucleic acids with the highest concentrations in the FN of NTg animals. The spectroscopic analysis showed significant differences in phosphates, amide and lipid structure in the FN of NTg animals in comparison with the same area of ALS rats. These results show that the hG93A SOD1 mutation causes metabolic cellular changes and point to a link between bioorganic composition and hallmarks of protein aggregation.
肌萎缩侧索硬化症（ALS）是一种致命的神经退行性疾病，其病理机制仍未得到充分了解。家族性ALS病例的一个子集是由金属酶铜锌超氧化物歧化酶（SOD1）的突变引起的，这增加了SOD1蛋白形成不溶性细胞内聚集体的易感性。在这里，我们采用基于同步辐射的傅里叶变换红外光谱和显微镜技术，研究了过表达人类突变SOD1的转基因hSOD1 G93A大鼠ALS模型的脑干横截面。我们比较了ALS大鼠及其非转基因同窝仔鼠（NTg）脑干组织横截面中的生物大分子有机组成。我们证明，在ALS大鼠脑干组织的所有三个区域：面神经核（FN）、巨细胞网状核（GRN）和三叉神经运动核（TMN）中，蛋白质尤其是其反平行β-折叠结构存在显著差异。蛋白质水平在不同的脑干区域有所不同，在NTg动物脑干组织的FN区域观察到最高浓度。此外，ALS动物的TMN和FN中脂质和酯的浓度显著降低。在NTg动物的FN中，与核酸相关的胆碱和磷酸盐浓度最高，也检测到了类似的模式。光谱分析表明，与ALS大鼠的相同区域相比，NTg动物的FN中磷酸盐、酰胺和脂质结构存在显著差异。这些结果表明，hG93A SOD1突变会导致细胞代谢变化，并指出生物有机组成与蛋白质聚集特征之间存在联系。
