2013-08-012024-05-14https://scholars.lib.ntu.edu.tw/handle/123456789/659709摘要：ALDH2 (acetaldehyde dehydrogenase 2, mitochondria) 是酒精代謝途徑中的酵素,當身體攝食乙醇後, 乙醇會先被轉成有毒性的乙醛(acetaldehyde), ALDH2 再將乙醛轉成較不具毒性的乙酸(acetic acid),ALDH2 對於其它具生物活性的醛類(aldehydes), 如4-hydroxynonenal (4-HNE), 也有活性。過去研究顯示, 具生物活性的醛類會造成多種細胞傷害, 在許多病理狀態, 如心肌缺氧, 糖尿病等都有致病角色。最近的一項研究找到小分子藥物alda-1 會與ALDH2 結合, 可以增加ALDH2 的酵素活性, 在動物實驗中顯示, alda-1 可以降低心肌缺氧時過4-HNE 的濃度, 進一步減少心肌受損的程度。我們初步的研究發現, alda-1 也可以減少胰島細胞的氧化壓力, 改善粒線體功能, 減少胰島細胞的凋亡, 以及增加胰島素分泌, 在動物模式中, 我們更發現alda-1 可以改善糖尿病小鼠的血糖, 胰島素分泌, 甚至是胰島素組抗性。我們計劃在未來三年完成:1. (a) 利用核糖核酸干擾技術在胰島細胞抑制ALDH2 表現(b) ALDH2 標的轉殖(knock-in)與剔除(knockout)小鼠分離的胰島細胞(c) ALDH2 的抑制劑daidzin (d) ALDH2 的促進劑, 探討ALDH2 在胰島細胞醛類代謝, 氧化壓力, 粒線體功能, 細胞凋亡, 以及胰島素分泌的角色。2. 利用上述方法, 探討探討ALDH2 在肝細胞, 脂肪細胞, 肌肉細胞中, 氧化壓力, 粒線體功能, 以及胰島素阻抗性的作用。3. 探討糖尿病及胰島素阻抗時, 醛類代謝與ALDH2 活性的變化。4. 以ALDH2 標的轉殖(knock-in)與剔除(knockout)小鼠, 餵食高脂飲食後, 評估其醛類代謝,氧化壓力, 粒線體功能, 胰島素分泌, 胰島素阻抗性, 以及血糖的變化。5. 確認alda-1 在糖尿病鼠Lep ob/ob 小鼠醛類代謝, 氧化壓力,粒線體功能, 胰島素分泌, 與降血糖的角色。<br> Abstract: The ALDH2 gene encodes the mitochondrial aldehyde dehydrogenase 2, a critical enzyme involved inalcohol metabolism. After alcohol ingestion, ethanol is first oxidized to acetaldehyde by alcoholdehydrogenase and subsequently converted to acetic acid by ALDH2. ALDH2also catalyze the metabolism ofother bioreative aldehydes including 4-hydroxynonenal (4-HNE). Previous studies indicated that bioreactivealdehydes caused multiple forms of cellular injury and played important roles in the pathogenesis of severaldiseases including myocardial ischemia and diabetes.A recent study found that a small molecular chaperon, alda-1, bound with ALDH2 and increased theenzymatic activity of ALDH2. In animal studies, alda-1 could lowered 4-HNE levels during myocardialischemia and reduced the extent of myocardial injury. We preliminarily found that alda-1 could also reducedthe oxidative stress, improved mitochondrial function, reduced cell apoptosis and increased insulin secretionof pancreatic beta-cells. In animal models, we further found that alda-1 could improve glucose homeostasis,increased insulin secretion, and improved insulin sensitivity in diabetic mice.We further plan to achieve following goals in 3 years:1. Investigate the role of ALDH2 in acetaldehyde metabolism, oxidative stress, mitochondrial function,cell apoptosis, and insulin secretion of pancreatic beta-cells using (a) ALDH2 knockdown technique(b) primary pancreatic beta-cells isolated from ALDH2 knock-in and knockout mice (c) daidzin, anALDH2 inhibitor (d) adla-1, an ALDH2 activator2. Investigate the role of ALDH2 in acetaldehyde metabolism, oxidative stress, mitochondrial function,and insulin signaling of adipocyte, myotubes, and liver cells3. Investigate changes of aldehydes metabolism and ALDH2 activity in diabetic and insulin-resistantstatus both in vitro and in vivo4. Investigate the role of ALDH2 in acetaldehyde metabolism, oxidative stress, mitochondrial function,insulin secretion, insulin sensitivity, and glucose homeostasis in vivo using high-fat diet-fed ALDH2knockin and knockout mice mode.5. Confirm the effect of alda-1 in acetaldehyde metabolism, oxidative stress, mitochondrial function,insulin secretion, insulin sensitivity, and glucose homeostasis in vivo in diabetic Lepob/ob mice model.ALDH2醛類氧化壓力粒線體功能胰島素分泌胰島素阻抗性糖尿病ALDH2acetaldehydeoxidative stressmitochondrial functioninsulin secretioninsulin sensitivitydiabetes