| 摘要: | 到公元2050年，全世界將有30%的高齡人口(>65歲)，台灣嬰兒潮黃金期已過，老年化情況 有更嚴重之趨勢。隨著老年化現象，社會為照顧老年化相關疾病，經濟負擔愈來愈沉重，因 此先進國家急需研究開發預防甚或緩和老化相關疾病的方法，其中從事規律體適能運動及攝 取健康蔬果及熱量限制(caloric restriction, CR)都被報導可以降低老年失智及神經退化。根據我 們最近的研究發現若能經由活化下述三大類神經保護分子機轉，可能可以有效增強內生性神 經再生，對於腦部神經退化之再造將有極大的助益，三大類分子機轉包括：1) 活化長壽基因 SIRT1及其相關訊息傳遞網(e.g., ADAM10/ADAM11/APP, CREB/TORC1/BDNF or PGC1, PGC1/PPAR/NFR1)以保護神經元；2) 抑制 glycogen synthase kinase 3 (GSK-3)其相關訊息傳 遞網 (e.g., p53/CREB/Akt/MMP-9/VEGF/HSF-1)，以有效對抗興奮神經毒性； 3) 藉由活化 Notch -1訊息傳遞及刺激腦部神經滋養因子製造 (e.g., Ang 1，Sdf1)可同時強化神經再生 (neurogenesis)、神經幹細胞遷徙、修補傷害並促進神經細胞分化。若能藉由找到合適方法或 藥物，可同時阻斷興奮神經毒性，強化血腦屏障再造，並促進神經再生、神經遷徙及神經分 化，將非常有助於預防甚或緩和老年失智及神經退化。最近許多研究顯示跑步運動會改變中 樞神經生理結構，特別是與學習記憶密切相關的海馬迴，該區可因從事正常跑步運動而增加 神經滋養因子表現，並促進血管增生和神經突觸可塑性，這些改變與從事運動能急遽提升神 經再生基因之分子機制密切相關，但跑步運動是否真能有效改善中風動物之神經病變並無深 入研究；另外服用白藜蘆醇 (resveratrol)可以模擬熱量限制 (CR mimetics) 活化長壽基因 SIRT1，因此我們提出本研究假說：常規跑步運動併用白藜蘆醇可以藉由去活化GSK-3及活化 以SIRT1並為中心的神經保護訊息傳遞機制網，降低興奮神經毒性，促進BDNF(神經滋養因子) 及血管新生使血腦屏障再造；或藉由活化Notch-1或Ang 1/Sdf1以促進內生性神經幹細胞(NSCs) 增生、遷徙修補及成熟分化。計畫設計理由：此假說乃依據許多文獻報導及我們初步研究發 現預先從事常規跑步運動可以顯著促進內生性神經幹細胞增生(doublecortin+ cells)；服用白藜 蘆醇(resveratrol)可以促進海馬迴附近SIRT1蛋白質之表現；因此若能經由本動物研究計畫，找 出預先從事正常跑步運動併用白藜蘆醇(resveratrol)所能激活之神經保護機轉及可能作用分子 標靶，將可提供該機轉及分子標靶做為預防神經退化、治療缺中風有效之生物標記(biomarker) 及藥物標靶 (molecular target)。研究目標：藉由探討從事常規跑步運動併用白藜蘆醇能否改 善輕微缺血型中風小鼠(模擬神經退化)之神經功能、神經生化學相關研究，找出常規跑步運 跑步運動併用白藜蘆醇促進學習記憶能力之分子機轉探討：以 SIRT-1 及 GSK-3 為中心的分子機制探討/文化大學劉國同副教授 2012/12/23, 3:22 PM 動併用白藜蘆醇所能活化之神經再生機轉及作用分子標的。為達成上述研究目的，我們特訂 定以下三項專一研究目標：專一目標#1(第1年)：探討從事常規跑步運動併用白藜蘆醇是否能 顯著活化長壽基因SIRT1及其相關訊息傳遞網 (e.g., RA/RAR/ADAM10/ADAM11/APP, CREB/TORC1/BDNF or PGC1, PGC1/PPAR/NFR1, LXR/NFB)以保護神經元；專一目標 #2(第2年)：探討從事常規跑步運動併用白藜蘆醇是否能顯著抑制中風鼠腦之GSK-3活性而活 化其下游相關神經保護訊息傳遞網 (e.g., p53/apoptosis; CREB/Bcl2; CREB/BDNF/PI3K/Akt; MMP-9/angiogenesis & migration; VEGF/angiogenesis; HSF-1/HSP70/NFB; CREB/BDNF/ neurogenesis)，以有效對抗興奮神經毒性並因而促進血管新生及神經再生；專一目標#3(第3 年)：探討從事常規跑步運動併用白藜蘆醇是否能經由活化 Nothch-1，並刺激滋養因子 Ang1/Sdf1製造，以促進內生性神經幹細胞增生、遷徙修補及成熟分化並經由活化Wnt/-catenin 及Ang1/Tie2等相關訊息傳遞，以有效促進血管新生，並激發血腦屏障再造。一般研究方法： 使用正常及輕微中風小鼠(模擬神經退化)，探討動物中風前4週，每天從事常規跑步運動1小時 或口服投予白藜蘆醇(10mg/kg/day)，比較有無從事常規跑步運動或投予白藜蘆醇之小鼠於正 常鼠及中風後7-28天內之活體動物腦神經功能恢復情形、血管新生暨BBB修補情形及內生性 神經幹細胞增生及分化情形、評估活體腦部發炎自由基影像及觀察神經行為損傷復原指數， 並測量腦梗死區域，對照免疫組織染色及RT-PCR檢驗發炎、氧化壓力、神經凋亡、神經自噬 及神經再生能力以了解預先從事常規跑步運動或投予白藜蘆醇所能活化之神經再造可能分子 機轉。預期成果：本研究成果將可了解從事常規跑步運動併用白藜蘆醇能否有效保護動物免 於輕微中風模擬神經退化傷害的機轉，是否與作用在三大類分子機制及關鍵分子標靶，包括 是否能：(1) 活化長壽基因SIRT1及其相關訊息傳遞網(e.g., PGC1/PPAR/NFR1 & LXR/NFB) 以達神經元保護作用；(2) 廣泛抑制興奮神經毒性(藉由抑制GSK-3)，促進血管新生/BBB再生 (藉由活化Wnt/-catenin)；(3) 促進神經再生(藉由活化Nothch-1))等訊息；本計畫結果將可提 供該有效分子標靶做為臨床發展成為預防神經退化及治療中風之藥物/策略之分子標靶考量。
By the year 2050, more than 30% of the total population will be over 65 years of age. This is also true in Taiwan as the baby boomers reach the golden age. As the aged population expands, the economic burden of care and treatment of those with age-related health disorders also increases, necessitating measures to prevent or even reverse age-related health disorders. Recent studies suggest that performing regular exercise and consumption of diets rich in antioxidants and anti-inflammatory components such as those found in fruits, nuts, vegetables, and spices, or even reduced caloric intake (caloric restriction, CR), may lower age-related cognitive declines and the risk of developing neurodegenerative disease. The goal of this project, we intend to decipher the specific and fundamental molecular targets involved in the neural protective effect by performing regular running in combination with CR-mimetics (by oral resveratrol (a SIRT1 activator)). We will use an in vivo slight-ischemic stroke murine model integrated with neurofunctional, neurological, and neurochemical approaches to elucidate the mechanisms involved. The central hypothesis is performing a regular running or in combination with oral resveratrol (CR-mimetic) can modify multiple beneficial and detrimental signaling molecules that centered at SIRT1 and GSK-3 to ameliorate stroke-induced excitotoxicity-mediated brain injury, enhance “angiogenesis” to remodel BBB, and promote “endogenous neurogenesis” to repair damaged neurons in a slight ischemic stroke mice. This hypothesis is based on our and other’s preliminary results showing that performing a regular running or in combination with oral resveratrol (CR-mimetic) daily can stimulate endogenous neurogenesis and exhibit neuroprotective activity. The rationale is performing a regular running or in combination with oral resveratrol (CR-mimetic) is well-known to be neuroprotective. We found that performing a regular running or in combination with oral resveratrol (CR-mimetic) can enhance expression of endogenous neurogenesis (doublecortin, DCX) gene and longevity gene SIRT1. To decipher whether and how performing a regular running or in combination with oral resveratrol (CR-mimetic) work on a slight ischemic stroke-mediated excitotoxicity in a murine model will lead to an effective therapeutic application (identify stroke biomarkers and drug targets) for hypoxia/ischemia-related neurodegenerative disorders. General Goal: To identify the fundamental molecular targets involved in the neuronal protective effects via performing a regular running or in combination with oral resveratrol (CR-mimetic) by using an in vivo slight ischemic stroke murine model integrated with neurofunctional, neurological, and neurochemical approaches for elucidation of neuronal cell proliferation, differentiation, maturation and microglial cell inactivation. Specifically, the following 3 aims will be studied: Specific Aim #1: to study whether performing regular running and/ or in combination with oral resveratrol (CR-mimetic) can enhance endogenous neurogenesis to promote learning and memory through SIRT-1 signaling pathways in a slight ischemic stroke murine model. Specific Aim #2: to study whether performing regular running or in combination with oral resveratrol (CR-mimetic) can promote neurogenesis through targeting GSK-3 signaling pathways in a slight ischemic murine model. Specific Aim #3: to study whether performing a regular running in combination with oral resveratrol (CR-mimetic) can enhance endogenous neurogenesis through Notch1 signaling pathways in a slight ischemic murine model. Expected Results of these specific aims, we will reveal performing regular running in combination with CR mimetis (oral resveratrol) can enhance endogenous neurogenesis, migration and differentiation of neuroprogenitor cells (NPCs), through activating SIRT1, Notch1, or inactivating GSK3 signaling in ischemic murine model. This can help to explain how performing regular running or in combination with CR mimetis could protect mice against ischemic brain injury and extend the life span of mice with an ischemic stroke. These results could help support performing regular running or in combination with resveratrol to be a beneficial strategy for the protection of neurodegenerative disorders. |
