探討黃嘌呤衍生物KMUP-1作用於Apo-E缺陷小鼠粥狀動脈硬化之病程延緩效果

The Xanthine Derivative KMUP-1 Attenuated the Progression of Atherosclerosis in Apolipoprotein E-Knockout Mice.

許智傑(Chih-Chieh Hsu)

指導教授 ： 葉竹來

高雄醫學大學/醫學院/醫學系藥理學科碩士班/碩士(2015年)

摘要

動脈粥狀硬化，目前仍然為全世界許多開發國家中引起心血管疾病高發病率及死亡率的首要原因，是一種複雜的慢性發炎與代謝性疾病，發展過程中，白血球會聚集並移行到血管壁中，同時有脂質的沉積，進而由巨噬細胞在動脈壁上形成泡沫細胞造成更嚴重的損傷。在本研究中，我們採用了自發性動脈粥狀硬化缺陷小鼠模式 (ApoE-KO mice)，ApoE缺陷小鼠會自發性地產生動脈硬化，為心血管實驗中研究動脈硬化的典型模式。先前的實驗指出，黃嘌呤類衍生物KMUP-1具有抗發炎、抗組織增生及心臟保護的特性。本篇論文的目的是希望探討KMUP-1對於ApoE缺陷小鼠的動脈粥狀硬化病程有無保護作用及其機制。
　　本實驗採用了雄性8週大的ApoE缺陷小鼠，隨機分為四組為期12週，分別為：(1) 控制組 (CTL)：餵食正常飼料；(2) 高脂肪組 (HFD)、(3) 預防組 (KMUP-1-P)、(4) 治療組 (KMUP-1-T) 皆餵食高脂肪飼料 (含0.15% 膽固醇及21% 脂質)，其中 (3) 於飲用水中投以藥物KMUP-1 (5 mg/kg/day) 12週，而 (4) 則是最後4週才投以同劑量藥物。整體實驗我們發現，KMUP-1抑制了ApoE缺陷小鼠的體重增加與心臟的增大，另外在小鼠犧牲前，利用非侵入式小動物超音波系統檢測不同組別ApoE缺陷小鼠的心臟功能，預防組 (KMUP-1-P) 與治療組 (KMUP-1-T) 的收縮分率 (FS%) 與血液射出分率 (EF%) 明顯優於高脂肪組 (HFD)。犧牲時採集小鼠血清進行血液生化分析，顯示KMUP-1降低了小鼠血液中的總膽固醇、三酸甘油脂及低密度膽固醇，相對地卻提高了高密度膽固醇；發炎物質方面，KMUP-1降低了小鼠血液中的IL-1?狻MTNF-?捁@度。KMUP-1降低了血管脂肪堆積的斑塊染色部分，亦減少了蘇木精與伊紅染色中內膜增厚所占腔室的比率。
　　在蛋白質的表現部分，顯示KMUP-1促進Atg7、Beclin-1、Bcl-2、Bax；Atg7的免疫螢光染色部分預防組則相對於治療組與高脂肪組有顯著的螢光反應。推論KMUP-1可能是透過促進細胞自噬減緩細胞凋亡的機制來改善粥狀動脈硬化的進程，有機會成為有效的抑制粥狀動脈硬化藥物。

關鍵字

粥狀動脈硬化 ； Apo-E缺陷小鼠

並列摘要

Atherosclerosis, a complex chronic inflammatory and metabolic disease, remains the leading cause of morbidity and mortality worldwide. Which is caused by the recruitment of blood monocytes, deposition of lipids, and formation of macrophage foam cells in the arterial wall. Apolipoprotein E-knockout (ApoE-KO) mice, a classic model of atherosclerosis, develop spontaneous atherosclerosis and thus have been widely used in cardiovascular research. In our previous studies, KMUP-1, a chemical synthetic xanthine-based derivative, has been shown its abilities of anti-inflammatory, anti-proliferation, and cardioprotective properties. This study aims to investigate whether KMUP-1 plays a protective role in inhibiting the progression of atherosclerosis in ApoE-KO mice.
　　For atherosclerosis studies, male ApoE-KO mice were randomly divided into four groups at the age of 8 weeks. High fat diet (HFD), prevention (KMUP-1-P) and treatment (KMUP-1-T) groups were fed with western diet containing 0.15% cholesterol and 21% fat (wt/wt) for 12 weeks. And the control (CTL) group was fed a normal chow diet for the same period. The KMUP-1-P group was administrated with KMUP-1 (5mg/kg/day) dissolved in drinking water for whole 12 weeks while the KMUP-1-T group for the last 4 weeks before sacrificing. According to our studies, KMUP-1 alleviated body and heart weight gain of ApoE-KO mice. In the echocardiography, FS% and EF% were improved in the KMUP-1-P and KMUP-1-T groups compared with the HFD group. The blood lipid profiles showed that KMUP-1 tended to decrease the level of TC, TG and LDL. However, KMUP-1 could somewhat increase the HDL level. Likewise, inflammatory cytokines IL-1?? and TNF-?? was decreased by KMUP-1. Histologically, atherosclerotic plaque with Oil-Red-O positive lesion areas were decreased in KMUP-1-given ApoE-KO mice.
　　KMUP-1 seemed to increase protein expressions of Atg7, Beclin-1, Bax and Bcl-2 in the aortic tissue of ApoE-KO. It is possible that KMUP-1 makes a protective role in the progression of atherosclerosis in ApoE-KO mice through the autophagy pathway. The results in our studies indicated that KMUP-1 may be a potential agent to restrict atherosclerosis development.

並列關鍵字

Atherosclerosis ； Apolipoprotein E-Knockout Mice

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