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標題: | 微小核糖核酸125b預測尿毒症相關血管鈣化存在及惡化危險性 Circulating MicroRNA-125b Predicts the Presence and Progression of Uremic Vascular Calcification |
作者: | Chia-Ter Chao 趙家德 |
指導教授: | 陳惠文(Huei-Wen Chen) |
關鍵字: | 生物指標,慢性腎臟病,末期腎病,微小核糖核酸,高磷血症,尿毒症,血管鈣化, biomarker,chronic kidney disease,end-stage renal disease,microRNA,hyperphosphatemia,uremia,vascular calcification, |
出版年 : | 2017 |
學位: | 博士 |
摘要: | 在末期腎病(end-stage renal disease)接受慢性透析的患者之中,血管鈣化(vascular calcification)以及其所帶來的血管彈性改變及血壓變化、是一種極為重要的死亡原因;然而、現有的各種檢驗以及檢查工具尚未能有效預測血管鈣化的進展以及惡化,因此發展出能夠預測此現象隨時間而改變狀態的生物標記(biomarker),是目前研究上亟待聚焦的課題.在本研究中,吾人假設循環中的分子、特別是胞外的微小核糖核酸(microRNA)有可能是潛在重要的有用標記,因此吾人利用三種不同的模型、分別是體外細胞模型、體外組織培養模型、以及動物模型來篩選出可能的微小核糖核酸標記,最後在末期腎病病人血清中進行檢驗其應用可行性.吾人將動物及人類的血管平滑肌細胞暴露於高磷培養基之中,接著利用Affymetrix的microRNA微陣列平台進行篩選、找出兩個microRNA標的在鈣化過程中會發生顯著改變,同時在培養基中驗證了只有一個microRNA標的會有同樣趨勢的改變;後續吾人在血管鈣化的動物模型以及體外主動脈培養的模型中觀察、此microRNA (miR-125b)在動物的主動脈以及血清中隨著血管鈣化的進展,是否有與體外模型之中類似的改變.前者結果發現,在動物主動脈以及血清中、miR-125b呈現出隨時間延續的表現量顯著下降,後者結果也發現,暴露於高磷狀態下的動物主動脈、組織miR-125b表現量也有顯著的下降,顯示在動物模型中、miR-125b有機會可以成為腎衰竭相關血管鈣化的進展指標.最後、吾人在末期腎病病人的血清中測試、循環中的miR-125b濃度是否與病人的血管鈣化相關.在一群共88位末期腎病病人的血清之中,吾人發現血清miR-125b表現量高低、與主動脈的鈣化嚴重度有獨立於年齡、及礦物質骨病變分子表現量以外的顯著關聯.此外、收案時的血清miR-125b表現量更被發現可以預測數年後的血管鈣化進展;這些發現顯示血清miR-125b表現量的確可以作為血管鈣化進展的預測因子. Among end-stage renal disease patients receiving chronic dialysis, vascular calcification with its associated changes in vascular compliance and blood pressure is an extremely important contributor to mortality. However, existing assays and measurement approaches fail to predict the temporal progression of vascular calcification, particularly those related to chronic kidney disease. Thus the quest for and the validation of biomarkers capable of tracing the course of vascular calcification are the centerpiece in contemporary researches and remain unexplored. In this study, we hypothesized that circulating molecules, especially extracellular microRNAs, can be potentially important markers for uremic vascular calcification. We used different types of experimental models to simulate this pathologic process, including in vitro cell culture with calcification medium, ex vivo organ culture, and in vivo chronic kidney disease animal model to screen for candidate microRNAs, followed by validation in sera from patients with end-stage renal disease. We exposed rat and human vascular smooth muscle cells to high phosphate-containing medium, and extracted RNA from cells at different time points. We subsequently used microRNA microarray to screen for promising microRNA candidates, and uncovered two microRNAs that exhibited significant changes during the course of cellular calcification. This trend was accompanied by similar changes in culture media for one of the candidate microRNAs described above. We further tested the expression level of this microRNA (miR-125b) in the ex vivo and in vivo model, and found that miR-125b decreased successively over time during the calcification process in aortas and sera as well. These findings, in combination, suggest that miR-125b can be a promising biomarker for predicting the progression of uremia-associated vascular calcification. Finally, we examined whether the circulating miR-125b levels among patients with end-stage renal disease were associated with the presence of vascular calcification. From 88 patients, we discovered that high serum miR-125b levels were significantly associated with the presence of aortic arch calcification, independent of age and mineral-bone disorder parameters. Furthermore, baseline serum miR-125b levels were predictive of worsening vascular calcification severity among survivors 2 years later, indicating that miR-125b can be a promising biomarker for predicting uremic vascular calcification progression. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/68169 |
DOI: | 10.6342/NTU201704395 |
全文授權: | 有償授權 |
顯示於系所單位: | 毒理學研究所 |
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