诱导活化肝星状细胞凋亡主要信号通路的研究进展

肝纤维化是各种病因引起的肝脏慢性进行性的病理过程,肝纤维化时细胞外基质(ECM)合成大于降解导致ECM在肝内大量沉积。肝星状细胞(HSC)的激活、转化并产生分泌大量ECM是肝纤维化形成的关键环节。而通过诱导活化的HSC发生凋亡是逆转肝纤维化的重要手段之一。就主要的凋亡信号通路:死亡受体通路、线粒体通路、内质网通路、神经生长因子通路进行一一阐述。指出了对活化HSC的凋亡途径进行选择性的药物干预有望发挥抗肝纤维化的作用。     

TGF-β1刺激肝星状细胞活化与肝纤维化的分子病理机制研究进展

研究证实，肝星状细胞（hepatic stellate cell，HSC）是肝纤维化的细胞学基础，转化生长因子β1（transforming growth factor-β1，TGF-β1）是促肝纤维化的关键细胞因子，慢性肝损伤时TGF-β1以自分泌和旁分泌两种形式促进HSC活化，使细胞向肌成纤维细胞（myofibroblasts，MFB）转化并生成大量细胞外基质（ECM），导致肝纤维化。TGF-β1具有广泛的生物学作用，可参与炎症、组织修复、肿瘤发生等病理生理过程，通过其细胞信号转导通路在不同环境条件下的变化而发挥相应作用。     

肝星状细胞活化相关信号通路在肝纤维化中的研究进展

肝纤维化是多种慢性肝损伤造成的细胞外基质(extracellular matrix, ECM)过度累积及降解不足的病理结果,如不加以干预会逐渐进展为肝硬化,甚至肝细胞癌。肝星状细胞(hepatic stellate cell, HSC)是ECM的主要来源,并且HSC在肝纤维化的起始、发展和消退过程中发挥关键作用。近年来,HSC活化涉及的信号传导通路成为研究热点,本文总结了HSC活化过程中的重要信号通路。     

肝星状细胞活化的关键路径

肝星状细胞（HSC）为肝纤维发生发展中心环节,活化状态HSC的凋亡是纤维化的关键特征。HSC激活转变为肌成纤维细胞（MFC）表型,收缩、增生,分泌胶原蛋白和其他细胞外基质（ECM）参与肝内结构的重建,通过集成信号网络调节ECM的沉积从而促进纤维化或者修复损伤。肝纤维化进展和逆转都需要特定信号通路,了解其在肝损伤中如何互动和演变对揭示肝纤维发生发展的复杂机制尤为关键。     

氧化应激与肝纤维化

肝纤维化的主要病理改变是细胞外基质(ECM)成分的过度合成与异常沉积,肝星状细胞(HSC)活化、增殖是肝纤维化形成的中心环节[1].诸多肝损伤因素在其致病过程中均不同程度地伴有氧化应激(oxidative stress,OS),这些病因不祛除、长期作用于肝脏即可导致肝纤维化乃至肝硬化.近年来,氧化应激与肝纤维化,特别是HSC活化的关系日益受到关注[2,3].本文就氧化应激在不同病因所致肝纤维化中的作用及其机制作一综述.……     

肝纤维化的发病机制及治疗进展

肝纤维化是肝脏内细胞外基质(Extracellular Matrix,ECM)弥漫性过度沉积性疾病,无假小叶形成,其发生机制主要是肝内ECM合成与降解失衡,表现为ECM大量沉积。肝纤维化是慢性肝病发展为肝硬化的中间环节,肝星状细胞(Hepatic Stellate Cell,HSC)在此过程中起关键性作用。HSC激活并转化为肌成纤维样细胞(Myofibroblastic-like cell,MFLC)和成纤维细胞fibroblastic cell,FC),是肝纤维化发生、发展的核心环节,肝损伤是引发肝纤维化的始动环节。肝细胞和其他肝非实质细胞旁分泌释放一些细胞因子激活HSC,活化的HSC增生,合成细胞外基质;同时表达部分细胞因子(自分泌),共同参与调控过程。与基质降解有关的金属蛋白酶(Matrix metalloproteinase,MMPS)、金属蛋白酶组织抑制因子(tissue inhibitor of metalloproteinases,TIMPS)、α_2-巨球蛋白也相应发生变化,最后导致ECM过度沉积,形成纤维化。     

肝内肌成纤维细胞和星状细胞在肝纤维化中的作用

肝纤维化是不同病因长期作用于肝脏所致损伤后修复反应,发病机制主要是肝内纤维生成,细胞活化、增殖,合成大量细胞外基质(extracellur matrix.ECM),并伴有ECM降解不足,最终导致其在肝内大量积聚.近来有研究提示除肝星状细胞(hepatic satellite cell,HSC)外,肌成纤维细胞(myofibroblast,MF)可能是另一类参与肝纤维化进程并发挥重要作用的细胞,进一步确证上述研究结果将助于针对不同类型肝纤维化寻找和采取不同的干预方法,以更有效地阻断肝纤维化的进展.     

蛋白酶活化受体(PARs)在肝纤维化中的调节作用

肝星状细胞(hepatic stellate cell,HSC)激活并转化为肌纤维母细胞并分泌细胞外基质 (ECM)成分是肝纤维化发生、发展的核心环节,肝损伤是引发肝纤维化的始动环节．蛋白酶激活受体(protease activated receptors, PARS)属于G蛋白偶联受体家族成员,他可通过介导细胞外信号调节激酶(extracellar signal- regulated kinase,ERK1／2)信号转导通路,引起细胞核反应,激活多种细胞转录因子,参与调节肝纤维化过程中HSC细胞增殖、分化和分泌大量细胞外基质,促使肝纤维化的发生和发展的方法,寻找通过抑制蛋白酶激活受体以期发现能阻断肝纤维化的形成和发展,逆转已形成的肝纤维化,将为肝纤维化的治疗提供新的理论基础．     

肝星状细胞的移行机制及药物干预研究

肝纤维化是各种慢性肝病向肝硬化发展的必经阶段。其关键环节是肝星状细胞（hepatic stellate cell,HSC）的激活。HSC的活化是导致细胞外基质（extracellular matrix,ECM）过度沉积,最终形成肝纤维化的主要原因。经典干预手段通过抑制HSC活化和促进HSC凋亡来逆转肝纤维化的进程,但也有部分学者认为HSC移行也是肝纤维化形成的重要机制之一。     

肝星状细胞凋亡与肝纤维化逆转

肝星状细胞(HSC)活化是肝纤维化形成的关键因素,但随着活化其凋亡敏感性增强,Fas／Fas-L、p75／NGF、PBR／PBR-L等介导HSC凋亡,金属蛋白酶组织抑制因子、细胞因子和药物等多种因素参与调控HSC凋亡,应用高选择性凋亡因素诱导活化HSC调亡将是治疗和逆转肝纤维化的理想途径。     

川芎生物碱对大鼠心肌细胞损伤的保护研究

目的通过观察川芎生物碱对大鼠心肌缺血产生损伤模型的影响,探讨其对缺血性心肌细胞损伤的保护作用。方法选取Wistar大鼠40只,雌雄各半,随机分为正常对照组、模型组及川芎生物碱高剂量组、低剂量组,每组各10只;各组均正常饲养,川芎生物碱高、低剂量组于实验前7d给予川芎生物碱50mg/kg·d和12.5mg/kg·d腹腔注射;建立大鼠心肌缺血损伤模型,记录心电图变化,测定血清各项相关生化指标。结果高剂量组可改变实验性大鼠急性心肌缺血的心电图S-T段变化幅度,减少心律失常发生率,提高心肌SOD活力,抑制CK活性,增加MDA含量。结论川芎生物碱能通过抑制心肌细胞凋亡以减少心肌缺血损伤,起到保护心肌作用。     

Beta Cell Workshop 2013 Kyoto

The very modern Kyoto International Conference Center provided the site for the 8th workshop on Beta cells on April 23–26, 2013. The preceding workshops were held in Boston, USA (1991); Kyoto, Japan (1994); Helsingør, Denmark (1997); Helsinki, Finland (2003); El Perello, Spain (2006); Peebles, Scotland (2009); and Helsingør, Denmark (2011). The Kyoto meeting drew more than 200 attendees from 18 different countries. There were 47 main oral presentations, and approximately 75 posters covered virtually all aspects of the pancreas function, development and genetics of disease. Here we will review some of the newest highlights.     

Does review of peripheral blood smears help in the initial workup of common anemias?

Sixty-five physicians were tested to determine the effect of their reviews of red blood cell morphology on their subsequent diagnoses of and workup plans for common anemias. The subjects read clinical and laboratory data for six pairs of cases of anemia, reviewing the blood smear for one case in each pair. They correctly identified the presence or absence of morphologic features on the blood smears 82% of the time. In spite of excellent morphologic discrimination, the number of tests ordered was not affected by blood smear review. In fact, the quality of the physicians’ workup plans, measured by numbers of tests appropriately ordered and excluded, was slightly but significantly better when they did not review the smears (p<0.005). In addition, smear review did not significantly improve diagnostic accuracy for any of the common anemias studied. Significantly more correct diagnoses were made without smear review for vitamin B₁₂-folate deficiency anemia (p<0.015) and thalassemia (p<0.0001). Although routine review of blood smears by physicians in the management of common anemias may provide useful information, the authors were unable to demonstrate an improvement in the number or appropriateness of tests ordered or diagnostic accuracy in spite of excellent morphologic discrimination. Received from the Divisions of General Internal Medicine and Hematology, Department of Medicine, Walter Reed Army Medical Center, Washington, DC, and the Uniformed Services University of the Health Sciences, Bethesda, Maryland. Dr. Simmons is now Chief, Division of General Internal Medicine, Brooke Army Medical Center, San Antonio, Texas. Presented in part at the annual meeting of the American Federation of Clinical Research, Washington, DC, May 3, 1986. Supported by a grant from the Department of Clinical Investigation (WU 1013), Walter Reed Army Medical Center, Washington, DC 20307-5001. The opinions and assertions contained herein are the private ones of the authors and are not to be construed as official or as reflecting the views of the Department of Defense, the Department of the Army, or the Uniformed Services University of the Health Sciences.     

Rabbit anti-mouse brain serum (RAMBS): Lack of specific inhibition of late committed erythroid stem cells in culture (CFU-E)

Summary Heterologous antisera to mouse brain tissue have activity against mouse pluripotent hemopoietic stem cells (CFU-S), but not against granuloid/ macrophage committed precursor cells (CFU-C). In these studies we show that anti-mouse brain serum raised in a rabbit does not possess specific activity in vitro against late committed erythroid stem cells (CFU-E).From the Section of Hematology, Department of Medicine, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois, U.S.A.     

Téloméropathies de recrutement hématologique : étude de 15 cas

IntroductionTelomeres are composed of a repeated sequence of double-stranded nucleotides TTAGGG and numerous proteins including the Shelterin complex. Their main role is to maintain the stability of the genome during cell replication through a mechanism of copying the repeted sequence by the telomerase complexe. All the diseases involving a deregulation of this complex are now grouped together under the term telomeropathies. They are difficult to diagnose and manage. Our objective was to describe the clinico-biological characteristics and treatments used, in patients affected by telomeropathies previously seen by an hematologist followed at the Lille University Hospital Center.MethodsThis is a retrospective, single-center study carried out within the department of internal medicine-clinical immunology, Reference center for rare autoimmune and systemic diseases at Lille University Hospital Center between 2005 and 2020 including all patients followed for telomeropathy.ResultsProbands and relatives were included. Fifteen patients were studied from 10 independant families. Sixty percent had an heterozygous TERC gene mutation. Sixty seven percent had haematological diseases including macrocytosis, anemia and/or thrombocytopenia, 20 % had a fibrotic hepatic disease, 27 % had a fibrotic pulmonary disease. Lymphocyte immunophenotyping showed a double negative T lymphocyte population with γδ TCR expression in 5 (33 %) patients. Forty-seven percent of the patients had not received any treatment. Twenty-seven percent were on androgen therapy. Twenty percent had received cyclosporine and 13 % anti-lymphocyte serum in the context of initial misdiagnosis.ConclusionIt is important to be aware of the complexity of telomeropathies, a differential diagnosis of immune aplastic anemia, in order to optimize management and avoid inappropriate treatments. Allografting of hematopoietic stem cells is the only potentially curative treatment. Our analysis found particularities in immunophenotyping lymphocyte not previously described to our knowledge, whose physiopathological imputability remains to be demonstrated.     

Lower number of cerebellar Purkinje neurons in psychosis is associated with reduced reelin expression

Reelin is an extracellular matrix protein synthesized in cerebellar granule cells that plays an important role in Purkinje cell positioning during cerebellar development and in modulating adult synaptic function. In the cerebellum of schizophrenia (SZ) and bipolar (BP) disorder patients, there is a marked decrease (≈50%) of reelin expression. In this study we measured Purkinje neuron density in the Purkinje cell layer of cerebella of 13 SZ and 17 BP disorder patients from the McLean 66 Cohort Collection, Harvard Brain Tissue Resource Center. The mean number of Purkinje neurons (linear density, neurons per millimeter) was 20% lower in SZ and BP disorder patients compared with nonpsychiatric subjects (NPS; n = 24). This decrease of Purkinje neuron linear density was unrelated to postmortem interval, pH, drugs of abuse, or to the presence, dose, or duration of antipsychotic medications. A comparative study in the cerebella of heterozygous reeler mice (HRM), in which reelin expression is down-regulated by ≈50%, showed a significant loss in the number of Purkinje cells in HRM (10–15%) compared with age-matched (3–9 months) wild-type mice. This finding suggests that lack of reelin impairs GABAergic Purkinje neuron expression and/or positioning during cerebellar development.     

以肝功能轻度异常为首发表现的高苯丙氨酸血症1例

高苯丙氨酸血症(hyperphenylalaninemia,HPA)是一种遗传代谢性疾病,以苯丙氨酸羟化酶(phenylalanine hydroxylase,PAH)活性缺乏,致血浆苯丙氨酸浓度升高为特征。该病早期无明显临床症状,随着病情加重会逐渐出现严重神经系统功能障碍,但首发症状为肝功能异常的着实罕见。本文现对1例以肝功能轻度异常为首发表现的HPA患者进行报道,并回顾相关文献,以进一步提高临床医生对此类疾病不典型表现的辨识能力,达到早诊断、早治疗的目的。     

血清高尔基体蛋白73在辅助诊断慢性乙型肝炎患者中度以上肝损伤中的应用

目的评价血清标志物高尔基体蛋白73(GP73)对慢性乙型肝炎患者肝组织炎症活动度与纤维化程度的诊断价值。方法回顾性收集2013年12月-2017年5月就诊于中国人民解放军第三〇二医院行肝穿刺检查的678例慢性乙型肝炎患者的血清,并随机分为2组(A组477例,B组201例),使用ELISA试剂盒,依照说明书进行血清GP73的定量检测。2独立样本间比较采用Mann-Whitny U检验,相关性比较使用Spearman相关性分析,定性资料组间比较采用χ2检验。结果血清GP73在A组与B组患者中均随着肝组织炎症活动度与纤维化程度的加重而升高,在A组患者中血清GP73与肝脏炎症活动度及纤维化程度均显著相关(r值分别为0.529、0.434,P值均<0.001),在B组患者中也得到了类似的结果(r值分别为0.418、0.437,P值均<0.001)。血清GP73诊断肝脏中度及以上炎症坏死(G≥2)及重度及以上炎症坏死(G≥3)的受试者工作特征曲线下面积,A组患者分别为0.774[95%可信区间(95%CI):0.733~0.811,P<0.001)和0.844(95%CI:0.808~0.875,P<0.001),B组患者分别为0.730(95%CI:0.663~0.790,P<0.001)和0.716(95%CI:0.649~0.777,P<0.001)。ALT联合血清GP73检测在A组中可以使77.4%的G≥2和(或)S≥2患者被鉴别出来,B组中78.9%的患者被鉴别出来。结论血清GP73可用于辅助ALT鉴别适宜抗病毒治疗的慢性乙型肝炎患者,减少对肝穿刺活组织检查的依赖。     

MLN4924对索拉非尼耐药肝细胞癌细胞中neddylation修饰的抑制作用

目的 索拉非尼是美国FDA于2007年批准的治疗肝细胞癌(hepatocellular carcinoma,HCC)的一线小分子抑制剂。然而,其在HCC患者中的反应率不高。本研究旨在进一步了解索拉非尼在HCC治疗中的作用机理,为HCC靶向治疗方法的优化提供理论基础。方法 使用蛋白印迹方法检测经索拉非尼治疗前后HCC细胞中与neddylation修饰相关蛋白的表达水平。通过CCK实验检测HCC细胞的增殖速率。结果 本研究发现索拉非尼能激活neddylation修饰相关的蛋白的表达。神经前体细胞表达的发育性下调蛋白8(neuronal precursor cell-expressed developmentally down-regulated protein8,NEDD8)激活酶抑制剂MLN4924通过抑制neddylation修饰来抑制索拉非尼耐药细胞的增殖。结论 索拉非尼能引起neddylation通路的活化。泛素激活酶NAE抑制剂可以进一步抑制对索拉非尼耐药的HCC细胞的增殖。