温州地区上半年空气细颗粒物对妊娠大鼠影响的研究

发布时间：2018-06-06 14:12

本文选题：可吸入颗粒 + 妊娠　；参考：《山东大学》2017年博士论文

【摘要】：研究背景空气污染,又称为大气污染,通常是指由于人类活动或自然过程引起的某些有害物质进入空气中,并累积达到足够的浓度,持续一定长的时间,由此危害了人类的健康和环境的现象。伴随我国经济发展的一个重要社会问题是空气污染,来源于自然因素如森林火灾和人为因素如工业废气排放、生活燃煤污染、汽车尾气排放等对我国的环境造成严重的影响。2012年联合国环境规划署发布了《全球环境展望》中指出,空气细颗粒物吸入会导致每年近200万的过早死亡。2013世界卫生组织下属的国际癌症研究机构发布报告,首次指认大气污染属于环境致癌物之一。我国于2014年首次将雾霾天气纳入自然灾情进行通报并指出应对雾霾污染、改善空气质量的首要任务是控制PM2.5,要从压减燃煤、调整产业、严格控车、严格管理、联防联控、依法治理等方面,聚焦重点致污染领域,管理指标考核,加强环境执法的监管。可吸入细颗粒物PM2.5是指大气总悬浮颗粒物中空气动力学直径≤2.5μ m的粒子,是空气中各种气态污染物经化学反应产生的二次粒子。PM2.5其成分主要为有机物、硫酸盐、硝酸盐以及地壳类元素,其中有机物已检测出多环芳烃、联苯类和含氮、硫、氧等原子的化合物,共110多种。其中多环芳烃是分子中含有两个以上苯环的碳氢化合物,包括萘、蒽、菲、芘等150余种化合物,它一种可以致癌、致畸、致突变的物质,具有很强的毒性。多环芳烃还能通过胎盘与DNA结合,诱发胎儿DNA损伤,影响胎儿的生长发育。国内外大量的流行病学研究表明PM2.5对机体健康有着不良影响。PM2.5表面吸附大量有毒有害物质,粒径小,能通过呼吸作用进入呼吸道深部,沉积在终末细支气管和肺泡,通过肺换气进入血液循环,改变循环系统功能,引发机体的一系列急性应激反应,从而导致相关疾病的发生。PM2.5能影响细胞的生理生化过程,改变信号传导通路,诱发蛋白质合成和降解失调、抑癌基因突变失活,癌基因异常表达,诱导细胞癌变,增加肺癌等癌症的发病率,并会导致某些职业暴露人群如交通警察、道路清洁工等的癌症发病率增加。pM2.5暴露被报道与许多慢性疾病的发生发展有关,如糖尿病、心血管疾病、哮喘等。长期暴露污染空气可使机体对胰岛素敏感性下降、胰岛素抵抗增强,尤其是对于生活方式健康的人群更为明显。胰岛素抵抗是指外周组织和靶器官对内和(或)外源性胰岛素的敏感性和反应性降低,胰岛素抑制肝脏葡萄糖输出及外周组织利用葡萄糖能力降低,血循环中葡萄糖利用减少,血糖升高。胰岛素抵抗是2型糖尿病及代谢综合征发病的关键环节,是糖尿病患者发生心血管并发症的独立危险因素。PM2.5暴露会导致机体的胰岛素抵抗水平增加和全身性炎症状态。大气中PM2.5浓度每增加10μg/m3,糖尿病的发生率上升1%。PM2.5暴露小鼠显示出异常的胰岛素抵抗和全身炎症反应。PM2.5暴露下小鼠的骨骼肌葡萄糖转运蛋白-4的表达水平显著降低,提示PM2.5能通过抑制骨骼肌细胞葡萄糖的转运,减少葡萄糖利用从而导致血糖水平升高,促进糖尿病的发生发展。妊娠期糖尿病(gestational diabetes mellitus,GDM)与2型糖尿病发病机制相似,有着类似的病理生理过程。妊娠是发生糖耐量异常的敏感阶段,许多本身糖耐量正常的孕妇的胰岛素抵抗状态逐渐增强,大约有18%的孕妇会在妊娠期间出现糖耐量异常。近年来有研究发现PM2.5与妊娠妇女的糖耐量损害有关,PM2.5进入机体后发生的氧化应激反应、全身及局部的炎症反应,同样也会发生在妊娠妇女身上。PM2.5持续暴露可导致机体组织AKT磷酸化水平改变,弱化胰岛素信号通路,导致多器官组织的胰岛素抵抗水平增强,促进糖代谢异常的发生发展,有研究认为污染空气暴露会加速孕妇胰岛素抵抗发生发展的病理生理过程。近年来,流行病学调查研究发现高浓度PM2.5孕期暴露与不良妊娠结局有关。早期胚胎由于细胞的增殖迅速,对营养和氧需求增加,空气污染物暴露会引发胚胎功能性损伤甚至结构异常。产前暴露于较严重的空气污染会引发低出生体重、早产、流产等,并与出生缺陷的比率升高有关。许多污染物通过气血交换进入母体血循环,在母胎界面以简单扩散等方式通过胎盘影响胎儿发育。众所周知,胎儿的发育与胎盘的功能息息相关。胎盘是母体与胎儿之间的桥梁,母体通过胎盘向胎儿输送氧气和各种营养成分,胎儿通过胎盘向母体排出代谢废物和二氧化碳。胎盘功能不良往往会引发多种不良妊娠结局如流产、胎死宫内等。许多有害物质能通过母胎血流在胎盘中蓄积,引发胎盘结构与功能障碍,并导致不良妊娠结局发生。胎盘作为孕期母亲与胎儿物质与气体的交换桥梁,其结构、功能变化与胚胎发育乃至远期预后密切相关。本课题组自2014年开始对孕期PM2.5暴露进行的系列的研究。我们通过观察大鼠孕期PM2.5暴露对胎盘结构的影响,以及孕鼠炎症指标、凝血功能状态、胎盘及仔鼠生长发育之间的相互关系,初步为研究孕期PM2.5暴露对胎儿生长发育造成的影响奠定基础。为了探讨PM2.5孕期暴露对母鼠及仔鼠的影响,对不同组织器官如胎盘和胰腺的作用及机制,我们设计并完成了以下二部分实验:第一部分:温州地区上半年PM2.5对妊娠期大鼠胎盘病理及围产结局的影响方法:1.PM2.5颗粒采集、混悬液制备。使用大流量采样器在交通主干道采样,将采集好的PM2.5颗粒配成混悬液备用。2.妊娠大鼠造模。3.妊娠大鼠随机分成2组,实验组于妊娠10天、18天分别接受PM2.5(15mg/kg)经气管内滴注,对照组同期接受同等剂量的生理盐水。最后一次暴露后24小时,所有的妊娠大鼠麻醉下处死。4.剖宫取出仔鼠和胎盘。观察仔鼠有无外观畸形,记录仔鼠数目并称量体重。5.检测血常规和血IL-6评估炎症和凝血功能水平。6.检测胎盘组织均浆液的谷胱甘肽过氧化物酶(Glutathione peroxidase,GSH-Px)和丙二醛(methane dicarboxylic aldehyde,MDA)含量评估胎盘组织的氧化损伤。7.胎盘组织行病理检查。结果:1.孕期PM2.5暴露下的妊娠大鼠胚胎吸收率更高,孕期母鼠体重增加及仔鼠出生体重均低于对照组(p0.05)。2.PM2.5孕期暴露导致孕鼠白细胞、血小板、IL-6水平升高((P0.01)。3.两组胎盘组织的GSH-Px和MDA水平无明显区别(P0.05)。4.实验组的胎盘组织病理检查发现胎盘血管内血栓形成及绒毛膜羊膜炎改变。结论:1.pM2.5孕期暴露会导致不良妊娠结局发生率明显升高、胎盘组织发生明显的病理改变。2.胎盘炎症、高凝及血栓形成可能是PM2.5暴露致胎盘损伤的重要的作用机制。第二部分:温州地区上半年PM2.5对血糖及胰腺葡萄糖转运蛋白2(glucose transporter 2,GLUT2)表达的影响方法:1.PM2.5颗粒采集、混悬液制备。使用大流量采样器在交通主干道采样,将采集好的PM2.5颗粒配成混悬液备用。2.GDM大鼠造模。3.GDM大鼠随机分成2组,实验组于妊娠10天、18天分别接受PM2.5(15 mg/kg)经气管内滴注,对照组同期接受同等剂量的生理盐水。最后一次暴露后24小时,所有的GDM大鼠麻醉下处死。4.试验期间,GDM大鼠每3天测量体重、每3天测尾血血糖并记录。5.暴露结束后,检测血常规和血IL-6来评估炎症和凝血功能水平。6.胰腺匀浆液检测GSH-Px和MDA含量评估胰腺组织的氧化损伤。7.检测胰腺葡萄糖转运蛋白2(GLUT2)水平。8.胰腺组织进行病理检查。结果:1.PM2.5暴露组的孕期母鼠体重增加(P0.05)及仔鼠出生体重(P0.01)均低于对照组。2.PM2.5孕期暴露导致胚胎吸收率增高,血白细胞、血小板、IL-6水平升高(P0.01)。多次餐后随机血糖水平高于对照组(P0.01)。3.PM2.5暴露组的胰腺经病理检查证实有明显的胰腺导管周围炎症反应。4.胰腺匀浆液的GSH-Px和MDA水平高于对照组(P0.01)。5.胰腺GLUT2蛋白水平明显低于对照组(P0.05)。结论:1.PM2.5暴露可导致GDM大鼠胰腺GLUT2蛋白表达下降、血糖水平升高,胰腺组织有明显的病理改变。2.氧化应激反应、炎症反应可能是PM2.5暴露引发胰腺损伤并加重GDM大鼠糖代谢异常的重要原因。
[Abstract]:Background air pollution, also known as air pollution, usually refers to the accumulation of certain harmful substances caused by human activities or natural processes into the air, and the accumulation of sufficient concentration, lasting a long period of time, thus endangering human health and the environment. An important social problem with the economic development of our country is empty. Gas pollution, derived from natural factors such as forest fires and human factors such as industrial exhaust emissions, living coal pollution, automobile exhaust emissions and so on, has a serious impact on the environment of our country. The United Nations Environment Programme issued the Global Environmental Outlook in.2012 that the inhalation of fine particles of air will lead to nearly 2 million premature death of.20 every year. 13 WHO, the International Cancer Research Institute, issued a report for the first time that air pollution is one of the environmental carcinogens. In 2014, our country first reported haze weather into the natural disaster and pointed out that the fog and haze pollution, the first task to improve the air quality was to control the PM2.5, to reduce the coal burning, to adjust the industry, and to strictly adjust the industry. Control car, strict management, joint prevention and control, management according to law, focus on pollution field, management index assessment, and strengthen the supervision of environmental law enforcement. The inhaled fine particulate matter PM2.5 is the particle of the air dynamics diameter less than 2.5 u m in the total suspended particulate matter of the atmosphere, and the two particle produced by the chemical reaction of various gaseous pollutants in the air. .PM2.5 is mainly composed of organic matter, sulfate, nitrate and crustal elements, in which polycyclic aromatic hydrocarbons, biphenyl and nitrogen, sulfur, oxygen and other atoms have been detected in more than 110 compounds. Polycyclic aromatic hydrocarbons are hydrocarbons containing more than two benzene rings, including naphthalene, anthracene, phenanthrene, pyrene and other 150 compounds. It can be carcinogenic, teratogenic, mutagenicity, and has strong toxicity. Polycyclic aromatic hydrocarbons can also be combined with DNA to induce fetal DNA damage and affect fetal growth and development. A large number of epidemiological studies at home and abroad have shown that PM2.5 has a bad effect on the body's health and adsorbs a large number of toxic and harmful substances on the surface of.PM2.5, which can pass through small size and can pass through Respiration enters the deep part of the respiratory tract, deposits in the terminal bronchioles and alveoli, enters the blood circulation through the lung ventilation, changes the function of the circulatory system and causes a series of acute stress responses of the body, which leads to the effect of.PM2.5 on the physiological and biochemical processes of the cells, the change of the signal transduction pathway, and the synthesis of protein and the synthesis of protein. Maladjustment, inactivation of tumor suppressor gene, abnormal expression of oncogene, induced canceration of cells, increasing the incidence of cancer such as lung cancer, and the increased incidence of cancer in some occupational exposures, such as traffic policemen, road cleaners, and.PM2.5 exposure are reported to be associated with the development of many chronic diseases, such as diabetes and cardiovascular disease. Prolonged exposure to air pollution can reduce the body's sensitivity to insulin and increase insulin resistance, especially in people with a healthy lifestyle. Insulin resistance is a reduction in the sensitivity and responsiveness of the peripheral and / or target organs to internal and / or exogenous insulin, and insulin inhibits the liver glucose output and The use of glucose in peripheral tissue decreases, glucose utilization decreases and blood glucose increases in blood circulation. Insulin resistance is a key link in the pathogenesis of type 2 diabetes and metabolic syndrome. It is an independent risk factor for cardiovascular complications in diabetic patients..PM2.5 exposure will lead to increased insulin resistance and systemic inflammatory symptoms in the body. The concentration of PM2.5 in the atmosphere increased by 10 mu g/m3, the incidence of diabetes increased in 1%.PM2.5 exposed mice and showed abnormal insulin resistance and systemic inflammatory response to.PM2.5 exposure. The expression level of glucose transporter -4 in skeletal muscle of mice decreased significantly, suggesting that PM2.5 could reduce the glucose transport of skeletal muscle cells and reduce the grapes. Sugar utilization can lead to higher levels of blood sugar and promote the development of diabetes. Gestational diabetes mellitus (GDM) is similar to the pathogenesis of type 2 diabetes and has a similar pathophysiological process. Pregnancy is a sensitive stage of impaired glucose tolerance, and a number of pregnant women with normal glucose tolerance are resistant to insulin. Gradually, about 18% of pregnant women have abnormal glucose tolerance during pregnancy. In recent years, studies have found that PM2.5 is associated with impaired glucose tolerance in pregnant women, oxidative stress after PM2.5 enters the body, systemic and local inflammatory reactions, and the persistent exposure to.PM2.5 in pregnant women can also lead to the body group. The changes in the level of phosphorylation of AKT and the weakening of insulin signaling pathway lead to the enhancement of insulin resistance in multiple organ tissues and the development of abnormal glucose metabolism. There is a study that polluted air exposure will accelerate the pathophysiological process of the development of insulin resistance in pregnant women. In recent years, the epidemiological investigation found that high concentration of PM2.5 pregnancy was found. Exposure to adverse pregnancy outcomes is associated with adverse pregnancy outcomes. Early embryos increase the demand for nutrition and oxygen due to rapid cell proliferation. Exposure to air pollutants may lead to functional damage and even structural abnormalities. Prenatal exposure to severe air pollution causes low birth weight, premature birth, abortion and so on, which is associated with a rise in birth defects. It is well known that the development of the fetus is closely related to the function of the placenta. It is well known that the fetal development is closely related to the function of the placenta. The placenta is a bridge between the mother and the fetus, the mother conveyed oxygen and various nutrients to the fetus through the placenta, and the fetus passed through the fetus. Disks discharge metabolic waste and carbon dioxide from the parent body. Abnormal placental function often causes a variety of bad pregnancy outcomes, such as abortion, fetal death, and so on. Many harmful substances can accumulate in the placenta by the maternal fetal blood flow, lead to placental structure and dysfunction, and lead to adverse pregnancy outcomes. Placenta is the mother and fetus of pregnancy. The exchange bridge of gas, its structure and function change closely related to embryo development and long term prognosis. The research group began a series of studies on PM2.5 exposure during pregnancy since 2014. We observed the effect of PM2.5 exposure on the placental structure during pregnancy, and the index of inflammation, the state of coagulation function, the growth and development of placenta and offspring. The relationship between birth and breeding lays a foundation for the study of the effects of PM2.5 exposure on fetal growth and development during pregnancy. In order to explore the effects of PM2.5 exposure on pregnant rats and offspring, and on the roles and mechanisms of different tissues and organs such as the placenta and pancreas, we have designed and completed the next two parts: the first part: the upper half of Wenzhou region The effect of PM2.5 on the placental pathology and perinatal outcome of pregnancy rats: 1.PM2.5 granule collection and suspension preparation. A large flow sampler was used to sample the main road of the traffic. The collected PM2.5 granules were divided into 2 groups of.3. gestation rats in a spare.2. pregnancy rat model. The experimental group received 10 days of pregnancy and 18 days to receive PM2., respectively. 5 (15mg/kg) was injected into the air tube, and the control group received the same dose of normal saline at the same time. 24 hours after the last exposure, all the pregnant rats were killed by.4. caesarean section to remove the offspring and placenta. The deformity of the offspring was observed and the number of the offspring was recorded and weighed by.5., and the blood routine and blood IL-6 were measured to evaluate the inflammation and coagulation function water. The levels of glutathione peroxidase (Glutathione peroxidase, GSH-Px) and malondialdehyde (methane dicarboxylic aldehyde, MDA) in placental tissues were measured by.6. in placental tissue to evaluate the pathological changes of placental tissue. The results showed that 1. pregnant rats exposed to PM2.5 were more absorbed in pregnant rats, and the weight of pregnant female rats increased. The birth weight of the mice was lower than that of the control group (P0.05). The exposure to.2.PM2.5 in pregnancy induced the leukocytes, platelets and IL-6 levels in the pregnant rats (P0.01) there was no significant difference between the GSH-Px and MDA levels of the placental tissue in.3. two groups (P0.05) the placental pathological examination of the.4. experimental group found the formation of intravascular thrombus in the fetal disc and the change of chorioamnionitis. Conclusion: 1.p Exposure to M2.5 during pregnancy could lead to a significant increase in the incidence of adverse pregnancy outcomes, placental tissue and pathological changes in.2. placenta inflammation. Hypercoagulability and thrombosis may be an important mechanism for placental injury induced by PM2.5 exposure. The second part: PM2.5 glucose and pancreatic glucose transporter 2 (glucose transporte) in the first half of the year in Wenzhou R 2, GLUT2) expression of the influence methods: 1.PM2.5 particles collection, suspension preparation. Using a large flow sampler sampling in the main road of the traffic,.3.GDM rats were randomly divided into 2 groups in the.2.GDM rat model of.2.GDM rats. The experimental group was treated with PM2.5 (15 mg/kg) in the air tube on the 18 day of pregnancy and the control group was the same as the control group. During the last 24 hours of the last exposure, 24 hours after the last exposure, all the GDM rats were killed in the.4. test, the GDM rats were measured every 3 days, the blood glucose was measured every 3 days and the.5. exposure was recorded. The blood routine and the blood IL-6 were detected to assess the levels of GSH-Px and MDA in the.6. pancreatic homogenate. To evaluate the oxidative damage of pancreatic tissue by.7., the pancreatic glucose transporter 2 (GLUT2) level.8. pancreatic tissue was examined. Results: the weight increase (P0.05) and the birth weight (P0.01) of the pregnant female rats in the 1.PM2.5 exposure group were lower than those of the control group, which resulted in the increase of the embryo absorption rate, blood leukocyte, platelet, IL-6 water during.2.PM2.5 pregnancy exposure. Ping Shenggao (P0.01). The level of postprandial random blood glucose was higher than that of the control group (P0.01).3.PM2.5 exposure group. The pancreatic duct pathological examination showed obvious pancreatic duct inflammatory response. The GSH-Px and MDA levels of.4. pancreatic homogenate were higher than those of the control group (P0.01).5. pancreatic GLUT2 protein water level was significantly lower than that of the control group (P0.05). Conclusion: 1.PM2.5 exposure can be found. The expression of GLUT2 protein in the pancreas of GDM rats decreased and the level of blood sugar increased. The pancreatic tissue had obvious pathological changes of.2. oxidative stress. The inflammatory reaction may be an important reason for the pancreatic injury caused by PM2.5 exposure and the aggravation of abnormal glucose metabolism in GDM rats.
【学位授予单位】：山东大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R714.2

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