突變老鼠普昂蛋白(F198S)纖維誘導神經母瘤細胞之蛋白質表達

Proteomic Analysis of Protein Expression in Neuroblastoma Cells Induced by Mouse F198S Prion Fibrils

李依儒(Yi-Ru Li)

指導教授 ： 李政怡

國立中正大學/理學院/生命科學系生物醫學研究所/碩士(2013年)

摘要

普昂疾病屬於神經退化性疾病，普昂蛋白經錯誤摺疊而聚集並累積於腦中，導致疾病產生，mutant的普昂蛋白是造成普昂疾病的原因之一，PrPC具有感染正常PrPC的能力，可以將PrPC變成PrPSc；普昂蛋白為一醣蛋白(glycoprotein)，藉由GPI結合在細胞膜表面，普昂蛋白纖維可能與細胞膜表面成分作用、傳輸凋亡信號、損傷細胞或活化神經膠質細胞產生發炎現象。然而，造成普昂疾病的機制，尚未被詳細地說明。因此我們想藉由蛋白質體學的分析方法，找出受影響的蛋白質，由這些蛋白質推測可能的致病機轉為何。
這項研究中，我們對於mutant普昂蛋白纖維的發病途徑感到興趣，其中有F198S突變會使得致病機率更高，使我們想先了解其中原因。因此，我們使用二維電泳的技術與利用MADLI-TOF質譜得到胜肽質量指紋圖譜並以軟體進行鑑定分析，發現普昂蛋白纖維在老鼠神經母瘤細胞之蛋白質所造成的影響。目前我們比對wild-type fibril和F198S fibril誘導神經母瘤細胞在蛋白質上的改變，我們將表現量有差異之蛋白分類，可分成蛋白質摺疊相關、細胞骨架相關、代謝相關、訊息傳遞相關、蛋白質/小泡運輸相關、壓力反應、免疫系統相關、發育相關、細胞週期和未知功能。根據結果顯示wild-Type fibril和F198S fibril誘導神經母瘤細胞所影響之調控路徑有差異。我們可以藉由本論文結果，更進一步驗證普昂蛋白是否影響相關路徑而導致疾病，期待藉由本論文提供普昂疾病可能的致病機制。

關鍵字

普利昂蛋白

並列摘要

Prion disease is one of the neurodegenerative diseases, an umbrella term for the progressive loss of structure or function of neurons. An abnormal isoform of the prion protein, PrPSc, can convert normal prion protein, PrPC, and aggregate into amyloid fibrils. Prion proteins attach on cell plasma membrane via GPI-anchor. Prion fibrils may have interaction with plasma membrane surface components and transmit apoptosis signals or damage cell by activated glia that produce inflammatory mediators. Up to date, investigation of the pathway involved in prion disease is not complete and the mechanism in detail of prion disease is still not clarified.
We are interested in the pathogenic pathway in mouse neuroblastoma (N2a) cells treated with prion fibril in this study. Proteomics is a fast and powerful tool in research. Therefore, we use two-dimensional electrophoresis to find the variation of protein expression in N2a cells caused by mutated prion (F198S) converted fibrils between the fibril-treated and the non-treated neuronal cells by proteomic analysis. Further, we use MADLI-TOF to find the peptide mass fingerprinting (PMF) of the proteins and then identify the proteins by flexAnalysis software. We found changes in proteins involved in protein folding, metabolism, immune system process, developmental process, response to stress, transport, cytoskeleton and unknown. Our data found that wild-type fibrils and F198S fibrils affect N2a cell in different pathways. This result can help us to understand the effect of mutated prion proteins involved in the diseases and to propose possible pathogenic pathway.

並列關鍵字

prion protein

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