Department of Translational Neuroscience, Michigan State University, Grand Rapids, MI, USA; Neuroscience Program, Michigan State University, East Lansing, MI, USA.
Department of Translational Neuroscience, Michigan State University, Grand Rapids, MI, USA; Neuroscience Program, Michigan State University, East Lansing, MI, USA; Mercy Health Hauenstein Neuroscience Medical Center, Grand Rapids, MI, USA.
Parkinsonism Relat Disord. 2021 Aug;89:41-47. doi: 10.1016/j.parkreldis.2021.06.010. Epub 2021 Jun 19.
Alpha-synuclein (α-syn) preformed fibril (PFF)-induced pathology can be used to study the features and progression of synucleinopathies, such as Parkinson's disease. Intrastriatal injection of mouse α-syn PFFs produce accumulation of α-syn pathology in both mice and rats. Previous studies in mice have revealed that greater sequence homology between the α-syn amino acid sequence used to produce PFFs with that of the endogenous host α-syn increases α-syn pathology in vivo.
Based on the prediction that greater sequence homology will result in more α-syn pathology, PFFs generated from recombinant rat α-syn (rPFFs) were used instead of PFFs produced from recombinant mouse α-syn (mPFFs), which are normally used in the model. Rats received unilateral intrastriatal injections of either rPFFs or mPFFs and accumulation of α-syn phosphorylated at serine 129 (pSyn) was examined at 1-month post-surgery.
Rats injected with mPFFs exhibited abundant accumulation of α-syn inclusions in the substantia nigra and cortical regions, whereas in rats injected with rPFFs had significantly fewer SNpc neurons containing pSyn inclusions (≈60% fewer) and little, if any, pSyn inclusions were observed in the cortex.
Our results suggest that additional factors beyond the degree of sequence homology between host α-syn and injected recombinant α-syn impact efficiency of seeding and subsequent inclusion formation. More practically, these findings caution against the use of rPFFs in the rat preformed fibril model.
α-突触核蛋白（α-syn）原纤维（PFF）诱导的病理学可用于研究突触核蛋白病的特征和进展，如帕金森病。纹状体注射小鼠α-syn PFF 可在小鼠和大鼠中产生α-syn 病理学的积累。以前在小鼠中的研究表明，用于产生 PFF 的α-syn 氨基酸序列与内源性宿主α-syn 的序列同源性越高，体内的α-syn 病理学就越多。
基于序列同源性越大导致更多α-syn 病理学的预测，使用来自重组大鼠α-syn（rPFF）的 PFF 代替通常在模型中使用的来自重组小鼠α-syn（mPFF）的 PFF。大鼠接受单侧纹状体注射 rPFF 或 mPFF，并在手术后 1 个月检查α-syn 磷酸化丝氨酸 129（pSyn）的积累。
注射 mPFF 的大鼠在黑质和皮质区域表现出大量α-syn 包涵体的积累，而注射 rPFF 的大鼠中含有 pSyn 包涵体的 SNpc 神经元数量明显减少（约减少 60%），皮质中几乎没有观察到 pSyn 包涵体。
我们的结果表明，宿主α-syn 和注射的重组α-syn 之间序列同源性之外的其他因素会影响种子形成和随后包涵体形成的效率。更实际地说，这些发现警告不要在大鼠预形成纤维模型中使用 rPFF。
