低氧诱导因子-1α在糖尿病肾病中作用机制的研究进展

低氧诱导因子-1α (HIF-1α)是一种核转录因子。在高糖低氧条件下,HIF-1α表达增加,诱导其下游靶基因VEGF、HO-1和BNIP3的表达,通过影响血管生成、细胞外基质沉积、铁代谢及线粒体自噬参与糖尿病肾病(DKD)的发生发展。此外,HIF-1α通过促进细胞因子的产生,参与DKD炎性反应并导致肾脏纤维化。     

蛋白质精氨酸甲基转移酶1在糖尿病小鼠肠屏障功能障碍中的作用

目的：探讨蛋白质精氨酸甲基转移酶1(protein arginine methyltransferase 1,PRMT1)通过沉默信息调节因子1(silent information regulator 1,SIRT1)/过氧化物酶体增殖物激活受体γ辅激活因子1α(peroxisome proliferator-activated receptor γ coactivator-1α,PGC-1α)信号通路对2型糖尿病（type 2 diabetes mellitus,T2DM）小鼠肠屏障功能损伤的作用。方法：20只8周龄SPF级C57BL/6小鼠随机分为对照组（n=5）和实验组（n=15）;将采用链脲佐菌素和高脂饮食构建T2DM小鼠模型的实验组,随机分为T2DM组、T2DM+PRMT1抑制剂AMI-1(arginine methyltransferase inhibitor 1)组和T2DM+白藜芦醇（resveratrol,Resv）组,每组5只。将对数生长期的人结肠上皮NCM-460细胞分为对照组、高糖（HG;50 mmol/L葡萄糖）组、HG+AMI-1组和HG+Resv组。采用...     

糖维胶囊对2型糖尿病大鼠视网膜缺氧诱导因子-1α和核因子-κB水平的影响

目的:分析糖维胶囊对2型糖尿病大鼠视网膜缺氧诱导因子-1α(HIF-1α)和核因子-κB(NF-κB)水平的影响。方法:健康雄性SD大鼠45只,10只作为正常组(NC组),其余使用链脲佐菌素(STZ)腹腔注射建立2型糖尿病大鼠模型(模型组),造模成功30只。成模后将模型组大鼠分为3个亚组,每组10只。糖尿病组(DM组)给予生理盐水灌胃,格列本脲治疗组(DM+G组)给予格列本脲20mg/kg灌胃,糖维胶囊治疗组(DM+T组)给予糖维胶囊150mg/kg灌胃治疗。连续灌胃4周后,取各组大鼠视网膜观察其病理改变并检测HIF-1α及NF-κB的mRNA及蛋白表达水平。结果:显微镜下观察,NC组视网膜所有细胞层清晰整齐地排列,在DM组中,视网膜水肿,DM+G组病变较轻,DM+T组未见明显新生血管形成,视网膜水肿显著减弱,神经节层整齐排列。与NC组相比,DM组HIF-1α、NF-κB mRNA及蛋白表达均明显上调(P0.05)。与DM组比较,DM+G组及DM+T组NF-κB mRNA及NF-κB、HIF-1α蛋白表达水平明显下降,且DM+T组NF-κB、HIF-1αmRNA和NF-κB蛋白下降较DM+G组更明显(P0.05)。结论:糖维胶囊能够影响HIF-1α、NF-κB因子表达,可明显改善大鼠2型糖尿病视网膜病变,为临床中西药联合治疗糖尿病提供一定依据。     

在CoCl_2模拟低氧条件下HIF-1α直接调控PPARγ2的表达

目的探讨在Co Cl2模拟低氧条件下,低氧诱导因子1α(HIF-1α)对于过氧化物酶体增殖物激活受体γ2(PPARγ2)是否具有调控作用。方法用real time PCR和Western blot检测Co Cl2模拟低氧条件下PPARγ2和低氧诱导因子1α(HIF-1α)mRNA及蛋白表达。用双荧光报告系统检测HIF-1α对于PPARγ调控的剂量依赖性,并通过染色质免疫共沉淀技术进一步验证。结果 Co Cl2模拟低氧条件下PPARγ2和HIF-1α的mRNA及蛋白表达水平均随着诱导时间的增加而增加。过表达HIF-1α导致PPARγ2表达上调(P0.01),而抑制HIF-1α则导致PPARγ2表达下调(P0.05)。HIF-1α对PPARγ2基因的表达具有正调控作用,通过结合于PPARγ2上游调控区特定的低氧应答元件(HRE)而调控其表达。结论 PPARγ2通过HIF-1α依赖的途径在Co Cl2模拟的低氧条件下发挥低氧适应作用。     

2型糖尿病肾微血管病变患者PAI-1、TNF-α水平变化

目的:观察2型糖尿病(T2DM)肾微血管病变患者纤溶酶原激活剂抑制物-1(PAI-1)、肿瘤坏死因子-α(TNF-α)水平变化及其与糖代谢指标的相关性。方法:T2DM患者125例,根据24h尿微量白蛋白(UMA)排泄量分为三组:(1)T2DM无肾病组(A组);(2)T2DM早期肾病组(B组);(3)T2DM临床肾病组(C组)。平行检测PAI-1、TNF-α和空腹血糖(FBG)、空腹胰岛素(FINS)、糖化血红蛋白(HbA1c)浓度。结果:(1)各组T2DM患者PAI-1水平均较正常对照组高,C组的PAI-1显著高于A、B组(P<0.01),B组高于A组(P<0.05)。(2)C组的TNF-α显著高于A、B组(p<0.01),B组高于A组(P<0.05)。(3)相关分析表明PAI-1与FINS、FBG,TNF-α与HbA1c、FINS具有显著正相关性(P<0.05)。结论:PAI-1、TNF-α升高与肾损害有关,可能是T2DM肾病发生的共同危险因素;降低PAI-1、TNF-α活性,对延缓T2DM微血管病变的发生发展有重要作用。     

HIF-1α/SDF-1信号轴在低氧诱导祖细胞迁移和黏附中的作用

目的: 分析低氧对大鼠肺动脉内皮细胞低氧诱导因子(HIF-1α)及间质细胞衍生因子(SDF-1)表达的影响,探讨二者的相互关系(即是否存在HIF-1α/SDF-1信号轴)及其在低氧诱导祖细胞迁移和黏附中的作用。方法: 免疫磁珠分离纯化SD大鼠外周血CD34/CXCR4阳性祖细胞,免疫荧光、Western blotting及ELISA法检测不同低氧时间HIF-1α和SDF-1在大鼠肺动脉内皮细胞的表达,迁移和黏附实验检测常氧组、低氧组、HIF-1α抑制剂2-甲氧雌二醇(2ME2)组、SDF-1中和抗体组及同时加2ME2和SDF-1中和抗体组祖细胞的迁移指数和黏附率。结果: HIF-1α和SDF-1的表达与低氧时间有关,低氧12 h时二者表达到峰值(均P<0.01),应用2ME2可使SDF-1表达下调(P<0.05),应用2ME2或SDF-1中和抗体后均下调祖细胞的迁移指数和黏附率(P<0.05)。结论: 低氧可诱导肺动脉内皮细胞HIF-1α及受其调控的下游因子SDF-1的表达,提示HIF-1α与SDF-1存在信号调节关系。HIF-1α/SDF-1信号轴在介导祖细胞迁移和黏附至肺动脉内皮细胞的过程中起重要作用。     

肠黏膜屏障在1型糖尿病中的作用研究进展北大核心CSCD

1型糖尿病(T1DM)是儿童和青少年常见的以胰岛β细胞破坏和胰岛素缺乏为特征的自身免疫性疾病。近期研究表明,肠道菌群失衡和肠黏膜屏障变化与T1DM发生发展相关,但具体机制尚不清楚。本文就近年肠道菌群、肠黏膜屏障在T1DM中的作用研究进行综述,并探讨孕期治疗、粪菌移植、益生菌、短链脂肪酸治疗维持健康肠黏膜屏障改善T1DM的研究进展,为T1DM防治提供新方法。     

胸腺肽α1联合DC疫苗对结肠癌体内外抗肿瘤的效应

目的观察胸腺肽α1(Tα1)对结肠癌细胞裂解物(TuLy)负载DC(LyDC)的表型和功能的影响,以及二者联合应用对裸鼠结肠癌的治疗作用.方法从健康人外周血单个核细胞中常规诱导培养未成熟DC(imDC),并负载TuLy后制备LyDC疫苗.Tα1体外刺激imDC、LyDC,流式细胞术(FCM)检测DC表型变化;ELISA法检测LyDC与自体T细胞共培养时,Tα1对LyDC分泌IL-12以及活化T细胞分泌IFN-γ水平的影响;MTT法检测LyDC经Tα1刺激后所诱导的细胞毒活性的变化.对HT-29结肠癌裸鼠模型行人源化T细胞免疫重建,观察LyDC与Tα1联合应用时的体内抗肿瘤效果.结果Tα1刺激后的imDC、LyDC表型HLA-DR、CD80、CD86、CD83均上调(P＜0.01);Tα1刺激组上清液中细胞因子IL-12和IFN-γ的水平较未刺激组增加(P＜0.05,P＜0.01);LyDC经Tα1刺激后诱导的CTL细胞毒活性较未经Tα1刺激组增强(P＜0.01).结肠癌裸鼠模型体内的人源化细胞免疫重建成功,在接种HT-29细胞58 d后,LyDC Tα1组和LyDC组的抑瘤率分别为60.41%和37.20%,二组之间瘤体积及瘤质量比较具有统计学意义(P＜0.01).结论Tα1可促进DC分化成熟,并能增强LyDC诱导的CD4 Th1细胞反应和CTL的杀伤效应.Tα1与LyDC疫苗联合应用时具有较好的免疫佐剂活性和抗肿瘤作用.     

缺氧诱导因子1研究进展

缺氧诱导因子1(HIF-1)在缺氧诱导的哺乳动物细胞中广泛表达,为缺氧应答的全局性调控因子。HIF-1由HIF-1α和HIF-1β两种亚基组成,为异源二聚体转录因子。HIF-1α、HIF-1β和近年来发现的HIF-2α一样均属于bHLH转录因子超家族中的PAS亚族。HIF-1α的bHLH和PAS结构域与二聚化及DNA结合活性有关,TAD结构域则主要参与转录激活。HIF-1α的全长基因已克隆并在人和小鼠中定位。通过作用于靶基因的缺氧反应元件(HRE),HIF-1参与缺氧诱导的一系列基因的表达调控。HIF-1在生物体的氧气供应、细胞代谢、心血管发育以及一系列疾病生理病理中起重要作用,其活性调节存在多种层次。HIF-1/HRE基因选择表达系统已被应用于基因治疗中。     

HIF-1α和HIF-2α在胃癌中的表达及意义

目的 探讨胃癌中低氧诱导因子HIF-1α和HIF-2α的表达及其临床意义。方法 用免疫组化SP法检测组织中HIF-1α、HIF-2α及VEGF的表达;用Western blot法检测组织中HIF-1α、HIF-2α的表达。结果 胃癌中HIF-1α、HIF-2α和VEGF的阳性表达率分别为61.5%、36.5%和61.5%,均显著高于正常对照组的11.1％、0和0;HIF-1α表达与VEGF及胃癌的淋巴结转移密切相关。胃癌组织中HIF-1α和HIF-2α蛋白的表达显著高于癌旁正常胃黏膜组织。结论 低氧诱导因子的表达可能在胃癌的发生、发展中具有重要作用。     

Disorders of iron metabolism. Part II: iron deficiency and iron overload

MAIN DISORDERS OF IRON METABOLISM: Increased iron requirements, limited external supply, and increased blood loss may lead to iron deficiency (ID) and iron deficiency anaemia. In chronic inflammation, the excess of hepcidin decreases iron absorption and prevents iron recycling, resulting in hypoferraemia and iron restricted erythropoiesis, despite normal iron stores (functional iron deficiency), and finally anaemia of chronic disease (ACD), which can evolve to ACD plus true ID (ACD+ID). In contrast, low hepcidin expression may lead to hereditary haemochromatosis (HH type I, mutations of the HFE gene) and type II (mutations of the hemojuvelin and hepcidin genes). Mutations of transferrin receptor 2 lead to HH type III, whereas those of the ferroportin gene lead to HH type IV. All these syndromes are characterised by iron overload. As transferrin becomes saturated in iron overload states, non-transferrin bound iron appears. Part of this iron is highly reactive (labile plasma iron), inducing free radical formation. Free radicals are responsible for the parenchymal cell injury associated with iron overload syndromes. ROLE OF LABORATORY TESTING IN DIAGNOSIS: In iron deficiency status, laboratory tests may provide evidence of iron depletion in the body or reflect iron deficient red cell production. Increased transferrin saturation and/or ferritin levels are the main cues for further investigation of iron overload. The appropriate combination of different laboratory tests with an integrated algorithm will help to establish a correct diagnosis of iron overload, iron deficiency and anaemia. REVIEW OF TREATMENT OPTIONS: Indications, advantages and side effects of the different options for treating iron overload (phlebotomy and iron chelators) and iron deficiency (oral or intravenous iron formulations) will be discussed.     

铁代谢对于β地中海贫血表型的修饰作用的研究进展

β地中海贫血(简称地贫)是由于β珠蛋白基因缺陷导致β珠蛋白肽链合成减少的遗传性溶血性疾病。其病理机制为α/β珠蛋白肽链比例严重失衡,多余的α珠蛋白链沉积形成包涵体,引发红细胞溶血、无效造血以及继发性多组织器官铁超载等。机体铁负荷过重可能导致生长发育停滞、肝硬化、心功能不全等并发症,加重其表型。近年来,随着机体铁代谢相关基因相继被发现,铁代谢在地贫的发生发展过程中的机理逐渐被阐明。研究人员通过改变铁调素、转铁蛋白受体等铁代谢关键基因的表达,揭示了限制红细胞铁应用可改善β地贫无效造血和铁过载的症状,为治疗地贫提供了一个新的途径。本文围绕铁代谢相关基因以及通路在β地贫中的研究进展进行综述。     

遗传性血色病的分子机制

近年来,铁代谢及其调节机制的研究取得了一系列突破性进展,有力地促进了遗传性血色病（hereditary hemochromatosis,HH）的分子机制的研究。本文综述了HH分子机制的最新研究,并从Hepcidin对铁代谢的调节角度探索、分析了其它可能的机制,针对目前研究面临的困难、缺陷和不足提出了一些建议。     

The new iron age

In the last four years there has been a major change in the approach to diagnosis of the iron overload disorder hereditary haemochromatosis (HH) following the discovery of the gene that is mutated in HH called HFE. In the first part of this review we will give a concise overview of the disease. Also the current literature on the role of HFE in iron absorption and transport at a molecular level and how mutations in HFE may lead to the break down in the regulation of iron homeostasis is reviewed. The second part of the review focuses on the molecular aspects of iron storage. Different chemical forms of storage iron deposits such as ferrihydrite and geotite are present in the iron storage proteins ferritin and haemosiderin. The type of iron storage deposits is thought to be an important factor in determining the degree of iron toxicity and tissue damage in patients with iron overload. Variations in the form of iron deposits in different types of iron overload disease e.g. HH or beta-thalessemia, the site of iron deposition and the clinical treatment used will be discussed.     

Pathophysiology and classification of iron overload diseases; update 2018

Iron overload pathophysiology has benefited from significant advances in the knowledge of iron metabolism and in molecular genetics. As a consequence, iron overload nosology has been revisited. The hematologist may be confronted to a number of iron overload syndromes, from genetic or acquired origin. Hemochromatoses, mostly but not exclusively related to the HFE gene, correspond to systemic iron overload of genetic origin in which iron excess is the consequence of hepcidin deficiency, hepcidin being the hormone regulating negatively plasma iron. Iron excess develops following hypersideremia and the formation of non-transferrin-bound iron, which targets preferentially parenchymal cells (hepatocytes). The ferroportin disease has a totally different iron overload mechanism consisting of defective egress of cellular iron into the plasma, iron deposition taking place mostly within the macrophages (spleen). Hereditary aceruloplasminemia is peculiar since systemic iron overload involves the brain. Two main types of acquired iron overload can be seen by the hematologist, one related to dyserythropoiesis (involving hypohepcidinemia ), the other related to multiple transfusions (thalassemias, myelodysplasia, hematopoietic stem cell transplantation). Congenital sideroblastic anemias, either monosyndromic (anemia) or polysyndromic (anemia plus extra-hematological syndromes), develop both compartimental iron excess within the erythroblast mitochondria, and systemic iron overload (through dyserythropoiesis and/or transfusions).     

Melatonin: Potential avenue for treating iron overload disorders

Iron overload as a highly risk factor, can be found in almost all human chronic and common diseases. Iron chelators are often used to treat iron overload; however, patient adherence to these chelators is poor due to obvious side effects and other disadvantages. Numerous studies have shown that melatonin has a high iron chelation ability and direct free radical scavenging activity, and can inhibit the lipid peroxidation process caused by iron overload. Therefore, melatonin may become potential complementary therapy for iron overload-related disorders due to its iron chelating and antioxidant activities. Here, the research progress of iron overload is reviewed and the therapeutic potential of melatonin in the treatment of iron overload is analyzed. In addition, studies related to the protective effects of melatonin on oxidative damage induced by iron overload are discussed. This review provides a foundation for preventing and treating iron homeostasis disorders with melatonin.     

Iron overload and heart fibrosis in mice deficient for both beta2-microglobulin and Rag1

Genetic causes of hereditary hemochromatosis (HH) include mutations in the HFE gene, a ss2-microglobulin (ss2m)-associated major histocompatibility complex class I-like protein. Accordingly, mutant ss2m(-/-) mice have increased intestinal iron absorption and develop parenchymal iron overload in the liver. In humans, other genetic and environmental factors have been suggested to influence the pathology and severity of HH. Previously, an association has been reported between low numbers of lymphocytes and the severity of clinical expression of the iron overload in HH. In the present study, the effect of a total absence of lymphocytes on iron overload was investigated by crossing ss2m(-/-) mice (which develop iron overload resembling human disease) with mice deficient in recombinase activator gene 1 (Rag1), which is required for normal B and T lymphocyte development. Iron overload was more severe in ss2mRag1 double-deficient mice than in each of the single deficient mice, with iron accumulation in parenchymal cells of the liver, in acinar cells of the pancreas, and in heart myocytes. With increasing age ss2mRag1(-/-) mice develop extensive heart fibrosis, which could be prevented by reconstitution with normal hematopoietic cells. Thus, the development of iron-mediated cellular damage is substantially enhanced when a Rag1 mutation, which causes a lack of mature lymphocytes, is introduced into ss2m(-/-) mice. Mice deficient in ss2m and Rag1 thus offer a new experimental model of iron-related cardiomyopathy.     

Transferrin and HFE genes interact in Alzheimer's disease risk: the Epistasis Project

Iron overload may contribute to the risk of Alzheimer's disease (AD). In the Epistasis Project, with 1757 cases of AD and 6295 controls, we studied 4 variants in 2 genes of iron metabolism: hemochromatosis (HFE) C282Y and H63D, and transferrin (TF) C2 and -2G/A. We replicated the reported interaction between HFE 282Y and TF C2 in the risk of AD: synergy factor, 1.75 (95% confidence interval, 1.1-2.8, p = 0.02) in Northern Europeans. The synergy factor was 3.1 (1.4-6.9; 0.007) in subjects with the APOEε4 allele. We found another interaction, between HFE 63HH and TF -2AA, markedly modified by age. Both interactions were found mainly or only in Northern Europeans. The interaction between HFE 282Y and TF C2 has now been replicated twice, in altogether 2313 cases of AD and 7065 controls, and has also been associated with increased iron load. We therefore suggest that iron overload may be a causative factor in the development of AD. Treatment for iron overload might thus be protective in some cases.     

磁共振检测重型β-地中海贫血患者内分泌腺体铁过载的临床意义

目的 联合肝脏、胰腺、垂体磁共振T2-star（MRI T2＊）评估重型β-地中海贫血（β-TM）患者相关脏器铁过载的临床意义,分析去铁酮治疗前后的肝脏、胰腺、垂体MRI T2＊变化的临床意义。方法 选择长期（输血史≥ 1年,输血次数＞ 10 次）治疗β-TM患者中选择年龄≥ 10岁26例,其中男性7例,女性19例。2010年7月 ～ 2011年7月规律输血,仅口服去铁酮去铁治疗,治疗前、服用去铁酮满1年时分别赴香港威尔斯亲王医院进行胰腺MRI T2＊（胰腺T2＊）、肝脏MRI T2＊（肝脏T2＊）、垂体MRI T2＊（垂体T2＊）检测。结果 服用去铁酮治疗前,肝脏铁浓度（LIC）（22.42 ± 7.21） mg/g;服用去铁酮满1年时,肝脏LIC（21.46 ± 7.69） mg/g。治疗前后肝脏、胰腺、垂体MRI T2＊值[（1.48 ± 1.23） ms vs （1.55 ± 1.18） ms,（9.09 ± 9.96） ms vs （9.51 ± 13.0） ms,（9.74 ± 4.46） ms vs （10.14 ± 4.76） ms]比较,差异无明显统计学意义（P 〉 0.05）。治疗前后肝脏与胰腺MRI T2＊值均呈正相关（P 〈 0.05）;治疗前后LIC与胰腺T2＊值均呈负相关（P 〈 0.05）。肝脏与垂体、胰腺与垂体MRI T2＊值治疗前后均不相关（P 〉 0.05）。年龄与肝脏、胰腺及垂体的MRI T2＊值无相关关系（P 〉 0.05）。结论 MRI T2＊可以作为评估β-TM患者胰腺、垂体铁负荷有效、安全的检测工具;可通过肝脏铁负荷来推测胰腺铁负荷,胰腺铁负荷与年龄无关;但肝脏负荷并不能作为垂体铁负荷的推测手段。去铁酮的临床疗效难以定论,有待进一步研究。     

Recent advances in the pathophysiology, diagnosis and treatment of hereditary hemochromatosis and other iron overload syndromes

Recent years have witnessed tremendous advances in the fields of pathophysiology, diagnosis and management of hereditary hemochromatosis (HH) and other iron overload syndromes, the dreadful consequences of which are fully preventable by early diagnosis and treatment. Missense mutations in HFE, a newly discovered gene encoding for a major histocompatibility class-I like molecule, have been found to be strictly associated with most cases of HH. The mechanisms by which a dysfunctional HFE molecule determines increased absorption of iron in HH are on the way to be fully clarified, due to the availability of a knockout mouse model. Epidemiologic studies have shown that HH is one of the most common human hereditary disorders. The possibility to identify HFE heterozygotes by means of a simple genetic test have prompted studies on the association between HFE mutations and iron overload syndromes different from HH. In the era of the historic completion of the human genome projects, genetic testing for HH may soon qualify for being adopted in universal population screening policies. In the present paper, the recent advances in the fields of genetics and pathophysiology of HH and other iron overload syndromes will be summarized. Furthermore, its clinical features, pathology and treatment will be reviewed, and the emerging issues of cost-effective diagnosis and of possible population screening strategies will be succintly discussed.