本文選題：呼吸睡眠暫停 + 間歇性低氧��； 參考：《吉林大學(xué)》2015年博士論文

【摘要】：阻塞性睡眠呼吸暫停（obstructive sleep apnea, OSA）低通氣綜合征，是一種最常見的嚴重危害人類健康的睡眠疾病之一。慢性間歇性低氧（chronic intermittent hypoxia, CIH）是OSA的主要病理特征，目前眾多學(xué)者應(yīng)用CIH的動物模型研究OSA所致的心臟損傷，發(fā)現(xiàn)CIH是引發(fā)包括心室重構(gòu)在內(nèi)的心臟損傷的主要原因。目前認為，氧化應(yīng)激是OSA所致心血管疾病的主要發(fā)病機制之一。我們在前期研究中發(fā)現(xiàn)CIH早期（3天）心肌組織未見明顯氧化應(yīng)激損傷同時伴隨金屬硫蛋白（metallothionein, MT）表達升高，然而在CIH晚期（4周和8周）MT表達下降、心肌氧化應(yīng)激水平升高并出現(xiàn)心肌損傷及心功能下降；并且MT心臟特異性過表達轉(zhuǎn)基因（cardiac-specific overexpressing MT gene, MT-TG）小鼠證實MT對CIH所致的心肌氧化應(yīng)激損傷、心肌纖維化、炎癥及心功能不全有明確的保護作用；與此同時MT基因敲除（MT-knockout, MT-KO）小鼠導(dǎo)致CIH誘導(dǎo)的心臟損傷提前出現(xiàn)并且程度加重。NF-E2相關(guān)因子2（NF-E2-related factor2,Nrf2）是一種含有亮氨酸拉鏈基本結(jié)構(gòu)的轉(zhuǎn)錄因子，屬于Cap-n-colla（rCNC）調(diào)節(jié)蛋白家族，是機體抵抗內(nèi)外界氧化和化學(xué)等刺激的重要的防御性轉(zhuǎn)導(dǎo)通路，促進細胞內(nèi)氧化還原環(huán)境的調(diào)節(jié)。 目的：明確Nrf2在CIH所致心臟損傷中的作用及其與MT的關(guān)系，并探討Nrf2激動劑萊菔硫烷（Sulforaphane, SFN）保護CIH誘導(dǎo)的心臟損傷的機制。 方法：CIH處理方案為20.9%O2/8%O2FIO2交替進行，30次/小時，，12小時/天，最低氧飽和度變化維持在60%-70%，用以模擬發(fā)生在中重度OSA患者的氧飽和度狀態(tài)；正常對照組給予同樣周期的間歇性正常氣流處理。本實驗主要分為三部分：第一部分實驗中將Nrf2-TG小鼠和野生型FVB小鼠暴露于CIH4周，Nrf2-KO小鼠和野生型C57BL/6J小鼠暴露于CIH3天和4周，每組小鼠為6只。第二部分中將MT-TG小鼠和野生型FVB小鼠暴露于CIH4周，MT-KO小鼠和野生型129S1小鼠暴露于CIH3天和4周，每組小鼠為6只。為進一步探討PI3K/Akt/GSK-3β/Fyn通路在調(diào)節(jié)Nrf2的表達中的作用，將FVB小鼠暴露于CIH3天，同時給予或不給予PI3K抑制劑LY294002，每組小鼠為6只。第三部分實驗為研究SFN在CIH誘導(dǎo)的心臟損傷中的保護作用及機制，將MT-KO和Nrf2-KO小鼠及各自的野生型小鼠暴露于CIH4周，同時給予或不給予SFN皮下注射，每組小鼠為6只。 結(jié)果：CIH早期（3天）小鼠心肌組織中Nrf2表達水平升高、晚期（4周及8周）下降，與MT的表達趨勢相同。Nrf2基因心臟過表達小鼠可保護CIH所致的心臟損傷、而Nrf2基因敲除小鼠心臟損傷進一步加重。Nrf2通過與MT的啟動子區(qū)結(jié)合進而促進MT的表達，MT可通過激活PI3K/Akt/GSK-3β/Fyn途徑調(diào)節(jié)Nrf2的功能。SFN可保護MT-KO小鼠中CIH所致的心臟氧化應(yīng)激損傷和心功能不全，而在Nrf2-KO小鼠中則失去保護作用。 結(jié)論：在CIH所致的心臟損傷中Nrf2和MT之間存在協(xié)同作用關(guān)系，二者皆對CIH所致的心臟損傷有保護作用。SFN的保護作用依賴于Nrf2的存在，而不是MT。
[Abstract]:Obstructive sleep apnea obstructive sleep apnea, OSA) hypopnea syndrome (OSAS) is one of the most common sleep diseases that seriously endanger human health. Chronic intermittent hypoxia, CIH) induced by chronic intermittent hypoxia is the main pathological feature of OSA. At present, many researchers use the animal model of CIH to study the heart injury induced by OSA. It is found that CIH is the main cause of cardiac injury, including ventricular remodeling. At present, oxidative stress is one of the main pathogenesis of cardiovascular disease induced by OSA. In our previous study, we found that there was no significant oxidative stress injury associated with increased expression of metallothionein (MTT) in myocardial tissue in the early 3 days of CIH. However, the expression of MT decreased at 4 and 8 weeks in the late stage of CIH. Myocardial oxidative stress level increased, myocardial injury and cardiac function decreased, and MT cardiac-specific overexpressing MT gene, MT-TGG mice confirmed that MT induced myocardial oxidative stress injury and myocardial fibrosis induced by CIH. At the same time, MT-knockout (MT-KOO) mice induced by MT gene knockout (MT-KOO) caused early and aggravated cardiac injury induced by CIH. NF-E2 related factor 2(NF-E2-related factor2Nrf2) is a transcription factor containing leucine zipper basic structure. Cap-n-colla-rCNC regulatory protein family is an important defensive transduction pathway to resist internal and external oxidation and chemical stimulation and promote the regulation of intracellular redox environment. Aim: to investigate the role of Nrf2 in CIH induced cardiac injury and its relationship with MT, and to explore the mechanism of Nrf2 agonist sulforaphane (SFN) in protecting heart injury induced by CIH. Methods 20.9%O2/8%O2FIO2 was performed 30 times / hour for 12 hours / day alternately, and the minimum oxygen saturation remained between 60 and 70 to simulate the state of oxygen saturation in moderate and severe OSA patients. The normal control group was treated with intermittent normal airflow during the same period. The experiment was divided into three parts: in the first part of the experiment, Nrf2-TG mice and wild type FVB mice were exposed to CIH4 week Nrf2-KO mice and wild type C57BL/6J mice to CIH3 days and 4 weeks, 6 mice in each group. In the second part, MT-TG mice and wild-type FVB mice were exposed to CIH4 week MT-KO mice and wild-type 129S1 mice to CIH3 days and 4 weeks. There were 6 mice in each group. In order to further investigate the role of PI3K/Akt/GSK-3 尾 / Fyn pathway in regulating the expression of Nrf2, FVB mice were exposed to CIH3 for days and were given PI3K inhibitor LY294002 at the same time, six mice in each group. In the third part, to study the protective effect and mechanism of SFN on CIH induced heart injury, MT-KO and Nrf2-KO mice and their wild-type mice were exposed to CIH4 for weeks and were given or not injected with SFN subcutaneously. There were 6 mice in each group. Results the expression of Nrf2 in the myocardium of mice was increased in the early 3 days and decreased at 4 and 8 weeks in the late stage. The same trend of the expression of MT. Nrf2 gene can protect the heart injury induced by CIH in the mice with over expression of NRF 2 gene. The cardiac damage in Nrf2 knockout mice was further aggravated. Nrf2 promoted the expression of MT by binding to the promoter region of MT. MT could regulate the function of Nrf2 by activating PI3K/Akt/GSK-3 尾 -Fyn pathway. SFN could protect the heart from oxidative stress induced by CIH in MT-KO mice. Injury and heart failure, In Nrf2-KO mice, however, there was no protective effect. Conclusion: there is a synergistic relationship between Nrf2 and MT in cardiac injury induced by CIH. Both of them have protective effect on heart injury induced by CIH. The protective effect of SFN depends on the existence of Nrf2 rather than MT.
【學(xué)位授予單位】：吉林大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2015
【分類號】：R766

【參考文獻】

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本文編號：1921700