CXCR4在肺型氧中毒致肺損傷機制中的作用研究
發(fā)布時間：2018-07-25 13:34
【摘要】：在潛水作業(yè)及高壓氧治療中,吸入氣氧分壓過高或吸氧時間過長導致肺部的功能和結(jié)構(gòu)發(fā)生病理性變化而表現(xiàn)出的癥狀稱之為肺型氧中毒。肺型氧中毒出現(xiàn)的癥狀易被腦型氧中毒的神經(jīng)系統(tǒng)癥狀掩蓋,且發(fā)病機制尚未完全明確,因此切實有效的干預措施和治療手段并不完善。若不及時進行治療,一旦進展為急性肺損傷甚至呼吸窘迫綜合癥,患者就可能進入全身多器官衰竭狀態(tài),預后極差。肺型氧中毒發(fā)生時肺內(nèi)肺泡-毛細血管屏障遭到破壞、出現(xiàn)氣體交換障礙、肺內(nèi)發(fā)生炎癥反應和肺水腫等病理學改變。在炎性因子和趨化因子的共同作用下,大量炎癥細胞在肺內(nèi)募集和黏附,不僅破壞肺臟血管內(nèi)皮屏障,還同時釋放大量的蛋白酶等物質(zhì),進一步加重肺內(nèi)炎癥反應程度和上皮細胞損傷,進而誘導更多信號轉(zhuǎn)導通路和轉(zhuǎn)錄因子的激活,形成所謂“放大”效應。肺損傷的嚴重程度與炎癥細胞浸潤密切相關,而炎癥細胞浸潤程度則與其趨化能力有關。因此,肺型氧中毒發(fā)生時,降低炎癥細胞的趨化能力和肺內(nèi)炎癥反應以及調(diào)節(jié)相關信號轉(zhuǎn)導通路活性成為目前治療氧中毒肺損傷的主要思路。趨化因子受體4(CXC Chemokine Receptor 4,CXCR4)屬于G蛋白耦聯(lián)受體蛋白超家族的一員,在炎癥反應、病原體清除等方面起到調(diào)節(jié)信號轉(zhuǎn)導、趨化炎癥細胞、維持炎性反應動態(tài)平衡等重要作用。相關研究發(fā)現(xiàn),高壓氧處理后大鼠肺組織出現(xiàn)出血、水腫,同時CXCR4表達顯著升高。據(jù)此推測其可能的機制為高壓氧狀態(tài)下血管內(nèi)皮細胞、肺泡上皮細胞損傷后,升高的CXCR4通過激活G蛋白耦聯(lián)的信號通路及轉(zhuǎn)錄因子引起細胞損傷、凋亡并釋放一系列炎癥因子,進一步損傷肺組織。但是其具體的損傷機制如相關信號轉(zhuǎn)導通路、下游炎癥因子水平變化及CXCR4在其中的作用機制仍不十分清楚。由此,本課題進行了以下研究:1、肺型氧中毒致肺損傷中CXCR4表達的變化規(guī)律:通過0.23MPa純氧高壓暴露復制動物模型,觀察高壓氧作用下不同暴露時間大鼠肺組織病理學改變,利用肺濕干重比、BALF總蛋白含量來判斷肺通透性變化,應用Western Blot方法研究肺組織CXCR4表達變化,ELISA法檢測炎癥因子TNF-α、IL-1β作為衡量下游炎癥因子水平變化依據(jù),探索肺損傷隨高壓氧暴露不同時間的變化規(guī)律,并對濕干重比、BALF總蛋白、TNF-α、IL-1β及CXCR4指標變化與UPTD劑量值進行相關性分析以探討CXCR4隨肺損傷程度變化而變化的規(guī)律及機制。2、CXCR4抑制劑對肺型氧中毒致肺損傷的干預作用:根據(jù)前期實驗結(jié)果,選擇指標變化最顯著的0.23MPa純氧暴露8小時方案,利用CXCR4特異性阻斷劑AMD3100進行預處理,并從大鼠肺組織病理學改變、肺通透性變化及CXCR4表達變化角度判斷AMD3100對大鼠肺型氧中毒致肺損傷的干預作用,觀察檢測炎癥因子TNF-α、IL-1β及凋亡蛋白Caspase3含量變化以研究下游信號通路在抑制劑干預下的變化情況,探究肺損傷中CXCR4抑制劑對肺型氧中毒致肺損傷的干預作用機制,進一步驗證CXCR4在肺型氧中毒致肺損傷機制中的作用。主要研究結(jié)果如下:1、本工作成功復制了0.23MPa高壓氧暴露不同時程大鼠肺型氧中毒模型,為下一步實驗奠定了實驗基礎。2、隨著高壓氧暴露時間的延長,大鼠肺組織病理學變化、肺通透性逐漸加重,與肺組織損傷程度相一致;高壓氧暴露后肺組織CXCR4表達明顯升高(P0.01),隨暴露時間變化逐漸升高,并在8小時組達到高峰,與炎癥因子TNF-α含量、IL-1β含量具有相同的變化趨勢。不同高壓氧暴露時間大鼠肺組織通透性指標、肺組織CXCR4、TNF-α及IL-1β含量與UPTD劑量均呈正相關(P0.01)。3、常壓空氣條件下預先應用CXCR4特異性抑制劑AMD3100處理大鼠,與使用PBS預處理相比,肺組織中CXCR4、TNF-α、IL-1β及活化的Caspase-3含量變化差異無顯著性(P0.05);而在高壓氧暴露下預先應用AMD3100處理與PBS預處理相比,大鼠肺組織中CXCR4、TNF-α、IL-1β及活化的Caspase-3含量降低,差異有顯著性(P0.01)。同時,應用AMD3100預處理后大鼠肺組織病理學檢查及通透性指標也有一定程度的減輕。表明CXCR4特異性抑制劑AMD3100可減輕大鼠肺型氧中毒致肺損傷程度,靶向CXCR4的肺型氧中毒致肺損傷治療方案更具針對性和選擇性,值得進行深入研究。綜上所述,本課題闡明了CXCR4在肺型氧中毒致肺損傷中發(fā)揮作用的可能機制,為找到干預肺型氧中毒致肺損傷有效靶點提供了新的依據(jù),為潛水作業(yè)及臨床治療提供有效的醫(yī)學保障。
[Abstract]:In the submersible operation and hyperbaric oxygen therapy, the symptoms of pulmonary oxygen poisoning are called pulmonary oxygen poisoning. The symptoms of pulmonary oxygen poisoning are easily concealed by the nervous system symptoms of brain oxygen poisoning, and the pathogenesis is not completely clear, so the pathogenesis is not completely clear. The effective intervention measures and treatment methods are not perfect. If they are not treated in time, the patients may enter the state of multiple organ failure, and the prognosis is extremely poor. With the joint action of inflammatory and chemokines, a large number of inflammatory cells collect and adhere to the lungs, not only destroy the blood vessel endothelial barrier, but also release a large number of proteases, which further aggravate the degree of inflammation of the lungs and the injury of epithelial cells. The activation of multiple signal transduction pathways and transcription factors form the so-called "amplification" effect. The severity of the lung injury is closely related to the infiltration of inflammatory cells, and the degree of infiltration of inflammatory cells is related to the chemotaxis. Therefore, when pulmonary oxygen poisoning occurs, it reduces the chemotaxis and inflammatory responses of the inflammatory cells and regulates the related letters. The activity of signal transduction pathway is the main idea for the treatment of lung injury in oxygen poisoning. Chemokine receptor 4 (CXC Chemokine Receptor 4, CXCR4) is a member of the protein superfamily of G protein coupled receptor. It plays an important role in regulating signal transduction, chemotaxis of inflammatory cells and maintaining dynamic balance of inflammatory reaction in the aspects of inflammatory reaction and pathogen clearance. It was found that after hyperbaric oxygen treatment, the lung tissue appeared bleeding, edema, and the expression of CXCR4 increased significantly. Accordingly, it was suggested that the possible mechanism was vascular endothelial cells in hyperbaric oxygen state. After the alveolar epithelial cells were damaged, the elevated CXCR4 caused cell damage by activating the signal pathway and transcription factors of G protein coupling and withering. A series of inflammatory factors are released to further damage the lung tissue, but the specific damage mechanisms such as related signal transduction pathways, the level of downstream inflammatory factors and the mechanism of CXCR4 in it are still not very clear. Therefore, the following studies have been carried out: 1, the changes in the expression of CXCR4 in lung injury induced by pulmonary oxygen poisoning: Over 0.23MPa pure oxygen high pressure exposure animal model, observe the pathological changes of lung tissue in rats with different exposure time under hyperbaric oxygen, use the ratio of wet dry weight of lung, BALF total protein content to determine lung permeability change, use Western Blot method to study the change of CXCR4 expression in lung tissue, ELISA method to detect the inflammatory factor TNF- a, IL-1 beta as the measure The change of lung injury with hyperbaric oxygen exposure at different time, and the correlation analysis of the changes of wet dry weight ratio, BALF total protein, TNF- alpha, IL-1 beta and CXCR4 and UPTD dose value to explore the regularities and mechanism of CXCR4 with the change of lung injury degree and mechanism.2, CXCR4 inhibitor in lung oxygen oxygen. The intervention effect of toxic lung injury: according to the previous experimental results, the most significant 0.23MPa oxygen exposure scheme was selected for 8 hours, and the CXCR4 specific blocker AMD3100 was pretreated. The lung tissue pathological changes, pulmonary permeability change and CXCR4 expression change angle were used to determine the lung damage induced by AMD3100 on lung oxygen poisoning in rats. The changes of the inflammatory factors TNF- alpha, IL-1 beta and apoptotic protein Caspase3 were observed and measured to study the changes in the downstream signal pathway under the intervention of inhibitors, and to explore the mechanism of intervention of CXCR4 inhibitors on lung injury induced by pulmonary oxygen poisoning in lung injury, and to further verify the mechanism of CXCR4 in lung injury induced lung injury mechanism. The main results are as follows: 1, this work successfully replicates the lung oxygen poisoning model of 0.23MPa hyperbaric oxygen exposure in different time course rats and lays a foundation for the next experiment. With the prolonged exposure of hyperbaric oxygen, the pathological changes of lung tissue and lung permeability are gradually aggravated, and the degree of lung injury is consistent with the degree of lung tissue injury. The expression of CXCR4 in lung tissue increased significantly (P0.01) after exposure to oxygen exposure, and increased gradually with the exposure time, and reached the peak in the 8 hour group. The content of TNF- alpha and inflammatory factor, IL-1 beta content had the same trend. The lung tissue permeability index of rats with different hyperbaric oxygen exposure time, the content of CXCR4, TNF- A and IL-1 beta in the lung tissue were all positive with the dose of UPTD. There was no significant difference in CXCR4, TNF- a, IL-1 beta and activation of CXCR4, TNF- a, IL-1 beta and activated Caspase-3 (P0.05) in lung tissue compared with the use of CXCR4 specific inhibitor AMD3100 under normal pressure air conditions, compared with PBS preconditioning (P0.05), while in hyperbaric oxygen exposure, AMD3100 treatment was compared with PBS preconditioning in the lung tissue of rats. CXCR4, TNF- alpha, IL-1 beta and activated Caspase-3 content decreased significantly (P0.01). At the same time, the pathological examination and permeability index of lung tissue of rats were also reduced to a certain extent after AMD3100 pretreatment. It showed that CXCR4 specific inhibitor AMD3100 could reduce lung injury induced by pulmonary oxygen poisoning in rats and target CXCR4 in lung oxygen oxygen. The treatment scheme for lung injury is more targeted and selective and deserves in-depth study. To sum up, this topic illustrates the possible mechanism of the role of CXCR4 in lung injury induced by pulmonary oxygen poisoning. It provides a new basis for finding effective targets for the intervention of lung injury caused by pulmonary oxygen poisoning and provides effective treatment for submersible operation and clinical treatment. Medical security.
【學位授予單位】：第二軍醫(yī)大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：R595
本文編號：2143982
[Abstract]:In the submersible operation and hyperbaric oxygen therapy, the symptoms of pulmonary oxygen poisoning are called pulmonary oxygen poisoning. The symptoms of pulmonary oxygen poisoning are easily concealed by the nervous system symptoms of brain oxygen poisoning, and the pathogenesis is not completely clear, so the pathogenesis is not completely clear. The effective intervention measures and treatment methods are not perfect. If they are not treated in time, the patients may enter the state of multiple organ failure, and the prognosis is extremely poor. With the joint action of inflammatory and chemokines, a large number of inflammatory cells collect and adhere to the lungs, not only destroy the blood vessel endothelial barrier, but also release a large number of proteases, which further aggravate the degree of inflammation of the lungs and the injury of epithelial cells. The activation of multiple signal transduction pathways and transcription factors form the so-called "amplification" effect. The severity of the lung injury is closely related to the infiltration of inflammatory cells, and the degree of infiltration of inflammatory cells is related to the chemotaxis. Therefore, when pulmonary oxygen poisoning occurs, it reduces the chemotaxis and inflammatory responses of the inflammatory cells and regulates the related letters. The activity of signal transduction pathway is the main idea for the treatment of lung injury in oxygen poisoning. Chemokine receptor 4 (CXC Chemokine Receptor 4, CXCR4) is a member of the protein superfamily of G protein coupled receptor. It plays an important role in regulating signal transduction, chemotaxis of inflammatory cells and maintaining dynamic balance of inflammatory reaction in the aspects of inflammatory reaction and pathogen clearance. It was found that after hyperbaric oxygen treatment, the lung tissue appeared bleeding, edema, and the expression of CXCR4 increased significantly. Accordingly, it was suggested that the possible mechanism was vascular endothelial cells in hyperbaric oxygen state. After the alveolar epithelial cells were damaged, the elevated CXCR4 caused cell damage by activating the signal pathway and transcription factors of G protein coupling and withering. A series of inflammatory factors are released to further damage the lung tissue, but the specific damage mechanisms such as related signal transduction pathways, the level of downstream inflammatory factors and the mechanism of CXCR4 in it are still not very clear. Therefore, the following studies have been carried out: 1, the changes in the expression of CXCR4 in lung injury induced by pulmonary oxygen poisoning: Over 0.23MPa pure oxygen high pressure exposure animal model, observe the pathological changes of lung tissue in rats with different exposure time under hyperbaric oxygen, use the ratio of wet dry weight of lung, BALF total protein content to determine lung permeability change, use Western Blot method to study the change of CXCR4 expression in lung tissue, ELISA method to detect the inflammatory factor TNF- a, IL-1 beta as the measure The change of lung injury with hyperbaric oxygen exposure at different time, and the correlation analysis of the changes of wet dry weight ratio, BALF total protein, TNF- alpha, IL-1 beta and CXCR4 and UPTD dose value to explore the regularities and mechanism of CXCR4 with the change of lung injury degree and mechanism.2, CXCR4 inhibitor in lung oxygen oxygen. The intervention effect of toxic lung injury: according to the previous experimental results, the most significant 0.23MPa oxygen exposure scheme was selected for 8 hours, and the CXCR4 specific blocker AMD3100 was pretreated. The lung tissue pathological changes, pulmonary permeability change and CXCR4 expression change angle were used to determine the lung damage induced by AMD3100 on lung oxygen poisoning in rats. The changes of the inflammatory factors TNF- alpha, IL-1 beta and apoptotic protein Caspase3 were observed and measured to study the changes in the downstream signal pathway under the intervention of inhibitors, and to explore the mechanism of intervention of CXCR4 inhibitors on lung injury induced by pulmonary oxygen poisoning in lung injury, and to further verify the mechanism of CXCR4 in lung injury induced lung injury mechanism. The main results are as follows: 1, this work successfully replicates the lung oxygen poisoning model of 0.23MPa hyperbaric oxygen exposure in different time course rats and lays a foundation for the next experiment. With the prolonged exposure of hyperbaric oxygen, the pathological changes of lung tissue and lung permeability are gradually aggravated, and the degree of lung injury is consistent with the degree of lung tissue injury. The expression of CXCR4 in lung tissue increased significantly (P0.01) after exposure to oxygen exposure, and increased gradually with the exposure time, and reached the peak in the 8 hour group. The content of TNF- alpha and inflammatory factor, IL-1 beta content had the same trend. The lung tissue permeability index of rats with different hyperbaric oxygen exposure time, the content of CXCR4, TNF- A and IL-1 beta in the lung tissue were all positive with the dose of UPTD. There was no significant difference in CXCR4, TNF- a, IL-1 beta and activation of CXCR4, TNF- a, IL-1 beta and activated Caspase-3 (P0.05) in lung tissue compared with the use of CXCR4 specific inhibitor AMD3100 under normal pressure air conditions, compared with PBS preconditioning (P0.05), while in hyperbaric oxygen exposure, AMD3100 treatment was compared with PBS preconditioning in the lung tissue of rats. CXCR4, TNF- alpha, IL-1 beta and activated Caspase-3 content decreased significantly (P0.01). At the same time, the pathological examination and permeability index of lung tissue of rats were also reduced to a certain extent after AMD3100 pretreatment. It showed that CXCR4 specific inhibitor AMD3100 could reduce lung injury induced by pulmonary oxygen poisoning in rats and target CXCR4 in lung oxygen oxygen. The treatment scheme for lung injury is more targeted and selective and deserves in-depth study. To sum up, this topic illustrates the possible mechanism of the role of CXCR4 in lung injury induced by pulmonary oxygen poisoning. It provides a new basis for finding effective targets for the intervention of lung injury caused by pulmonary oxygen poisoning and provides effective treatment for submersible operation and clinical treatment. Medical security.
【學位授予單位】：第二軍醫(yī)大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：R595
【參考文獻】
相關期刊論文 前3條
1 李彩霞,張學光;SDF-1/CXCR4的研究進展[J];國外醫(yī)學(分子生物學分冊);2003年06期
2 靳麗妍;朱光發(fā);;急性肺損傷/急性呼吸窘迫綜合征與炎癥因子關系的研究[J];臨床肺科雜志;2010年07期
3 邱海波,代靜泓,燕艷麗,楊毅,周韶霞;腫瘤壞死因子和白細胞介素-1基因多態(tài)性與急性呼吸窘迫綜合征的相關性研究[J];東南大學學報(醫(yī)學版);2004年01期
，本文編號：2143982
本文鏈接：http://sikaile.net/yixuelunwen/nfm/2143982.html
最近更新
教材專著
