肝豆状核变性培养细胞内微粒体铜转运的研究

肝豆状核变性 (Wilson disease,WD)的基因已被克隆 ,定位在 13q14.3。序列分析表明 ,该基因编码一个由 1411个氨基酸组成的铜转运 P-型 ATP酶 [1 ]。有关该酶在亚细胞结构的定位及在细胞铜代谢中的作用 ,尚不清楚。有学者 [2 ,3 ] 对从细菌到人不同类型细胞的铜转运 P型 ATP酶进行了探讨 ,结果不一。我们采用人离体培养皮肤成纤维细胞模型 ,对 WD患者、杂合子及正常人皮肤成纤维细胞 ,经 P型 ATP酶阻滞剂 (矾酸钠 )或激动剂 (长春新碱 )孵育后 [4] ,微粒体铜代谢情况进行分析 ,初步探讨 P型 ATP酶在人成纤维细胞亚细胞结构中的定位…     

CRISPR-Cas9系统在真核细胞领域内的研究进展

CRISPR-Cas免疫系统在天然状态下保护细菌和古生菌免受外来质粒或噬菌体的入侵.研究者们根据Ⅱ型CRISPR-Cas系统开发了全新的基因编辑工具——CRISPR-Cas9,它利用与靶序列互补的向导RNA引导Cas9酶定点切割DNA,该技术具有设计简单、操作方便、特异性强、效率高等优势,成为新一代基因组编辑技术.本文综述了CRISPR-Cas系统的技术发展史、最新分类和作用原理,重点介绍了近几年来CRISPR-Cas9系统应用于真核细胞领域的研究进展.     

ABC-AⅠ调节胆固醇跨细胞膜外向转运的研究进展

胆固醇跨细胞膜外向转运是胆固醇逆向转运过程(RCT)中具有关键意义的一步,三磷酸腺苷结合盒转运子家族AⅠ（ABCA-Ⅰ）在该过程中被公认为发挥十分重要的作用且对其研究至今仍然在不断深入。目前,大多数学者认为对其作用机制及与其他参与该过程的物质间相互作用的研究有可能成为防治动脉粥样硬化并促其转归的新突破口。     

钙调节激素对培养的纹状体细胞Ca^2＋转运的影响

本文观察了钙调节激素——甲状旁腺素(PTH)和降钙素(CT)对培养成活的脑纹状体神经细胞~(45)Ca转运的影响。结果表明,PTH(10-~7M)明显促进静息状态和去极化状态下细胞对~(45)Ca的摄取,并抑制去极化状态下的~(45)Ca释放,使胞内~(45)Ca净摄取量明显增加。CT(1u/ml)对细胞在静息状态下的~(45)Ca摄取无影响,但抑制去极化细胞的~(45)Ca摄取与释放,使胞内~(45)Ca净摄取最明显减少。结果提示,这两种钙调节激素可能通过影响神经细胞内的Ca~(2+)水平,参与某些中枢性的生理功能的调节。     

微量元素铁,锌及铜对大鼠免疫功能的影响

为了解微量元素铁、锌及铜与免疫关系,选用北京1号7—9周龄健康大鼠126只,随机分为低铁、高铁、低锌、高锌、低铜、高铜及对照组,各组18     

枸橼酸铁铵对原代培养的大鼠心肌细胞铜蓝蛋白、膜铁转运辅助蛋白和膜铁转运蛋白表达的影响

目的 观察枸橼酸铁铵(FAC)对原代培养的大鼠心肌细胞铁释放相关蛋白表达的影响,探讨枸橼酸铁铵对心肌细胞铁代谢的影响机制. 方法 以原代培养的乳鼠心肌细胞为材料,分为对照组、20mg/L枸橼酸铁铵组、40mg/L枸橼酸铁铵组和80mg/L枸橼酸铁铵组,每组6个重复.然后检测心肌细胞存活率、搏动频率,免疫组织化学检测铜蓝蛋白(CP)、膜铁转运辅助蛋白(HP)和膜铁转运蛋白(FP1)表达的变化. 结果 各剂量枸橼酸铁铵对大鼠心肌细胞存活率无明显影响;心肌细胞搏动频率减慢,停止跳动的细胞数量明显增加,收缩幅度逐渐降低;随着枸橼酸铁铵浓度的增加,心肌细胞铜蓝蛋白、膜铁转运辅助蛋白和膜铁转运蛋白的表达均增加. 结论 枸橼酸铁铵影响大鼠心肌细胞的生理功能,IRP-IRE可能参与膜铁转运蛋白表达的调控,铜蓝蛋白、膜铁转运辅助蛋白表达的升高可能与铁处理增加细胞的氧化紧张性有关.     

P型铜转运ATP酶和增殖细胞核抗原在大、小鼠肝的表达

目的:研究P型铜转运ATP酶(ATP7B)与增殖细胞核抗原(PCNA)在大鼠和小鼠肝组织中的表达.方法:采用免疫组织化学法检测肝中ATP7B与PCNA的表达.结果:ATP7B在大鼠和小鼠的肝细胞质表达,表达较广泛.肝细胞PCNA的表达强弱不一,强阳性细胞较少,大鼠和小鼠肝的ATP7B和PCNA积分光密度间的差异均无统计学意义;在大鼠或小鼠肝,ATP7B与PCNA的免疫反应阳性物积分光密度间无显著相关性.结论:ATP7B和PCNA在大鼠和小鼠肝组织均有表达,表达的关联性不明显.     

精神分裂症患者血清锌、铜及急性期反应蛋白水平的变化

目的：探讨精神分裂症是否伴有血清微量元素锌、铜水平的异常，及其与急性期反应的关系。方法：分别采用原子吸收光谱法、散射速率比浊法测定了42例健康对照及67例精神分裂症患者治疗前后的血清锌、铜和结合珠蛋白（Hp)、转铁蛋白（Tf)水平。结果：精神分裂症组急性期血清Zn、Tf水平显著低于健康对照组，Cu、Hp水平显著高于健康对照组；精神分裂症组血清Zn、Cu和Hp、Tf水平在缓解期（治疗6周后）均恢复至与对照组相接近的水平；精神分裂症组血清Zn与Hp水平显著负相关，Cu与Hp无显著相关；未发现BPRS评分与血清Zn、Cu或Hp、Tf水平之间存在明显相关关系。结论：精神分裂症急性期伴有血清微量元素Zn、Cu水平的改变，这种改变可能是与急性期反应有关的非特异性状态改变。     

Wilson病基因产物及铜转运P型ATP酶的研究进展

肝豆状核变性(WD)基因已被克隆,序列分析表明,其基因产物(ATP7B)编码的是一种含有1411个氨基酸的铜转运P型ATP酶。ATP7B具有这些酶所独有的功能结构区:金属离子结合位点、阳离子转导区、SEHP序列及跨膜区等,WD基因高频突变位点多与这些结构有密切关系。对ATP7B的深入研究将为探讨WD的发病机制及诊断和治疗提供帮助。     

Evolutionary Origin of Eukaryotic Cells

This article reviews literature on the transition from rudimentary prokaryotic life to eukaryotes. An overview of the differences between these organisms and theories of eukaryogenesis are reviewed. Various methods of investigating the transformation from prokaryotes to eukaryotes are elaborated, including the fossil, the molecular and living records, and examples are given. Lastly, the recent molecular studies and the impact on phylogenetic classification for the tree of life, based on molecular evolution, are discussed.     

The Unfolded Protein Response in Homeostasis and Modulation of Mammalian Immune Cells

The endoplasmic reticulum (ER) plays important roles in eukaryotic protein folding and lipid biosynthesis. Several exogenous and endogenous cellular sources of stress can perturb ER homeostasis leading to the accumulation of unfolded proteins in the lumen. Unfolded protein accumulation triggers a signal-transduction cascade known as the unfolded protein response (UPR), an adaptive mechanism which aims to protect cells from protein aggregates and to restore ER functions. Further to this protective mechanism, in immune cells, UPR molecular effectors have been shown to participate in a wide range of biological processes such as cell differentiation, survival and immunoglobulin and cytokine production. Recent findings also highlight the involvement of the UPR machinery in the maturational program and antigen presentation capacities of dendritic cells. UPR is therefore a key element in immune system homeostasis with direct implications on both adaptive and innate immune responses. The present review summarizes the knowledge on the emerging roles of UPR signaling cascades in mammalian immune cells as well as the consequences of their dysregulation in relation to the pathogenesis of several diseases.     

外扰作用下细胞内稳态鲁棒性实验研究

内稳态是一种重要的生理现象,是生物反应动态平衡的结果.以内皮细胞为对象,用H2O2作为外源扰动剂,建立一种外扰作用下细胞内钙稳态鲁棒性的分析方法,包括以控制理论Lyapunov及鲁棒性理论为基础的扰动前稳态点和稳定域、扰动后状态转移和稳定鲁棒域.通过对照和1、10、30、50、100 μmol/L 5种不同剂量H2O2...     

Intestinal Antigen-Presenting Cells: Key Regulators of Immune Homeostasis and Inflammation

The microbiota that populate the mammalian intestine are critical for proper host physiology, yet simultaneously pose a potential danger. Intestinal antigen-presenting cells, namely macrophages and dendritic cells (DCs), are integral components of the mucosal innate immune system that maintain co-existence with the microbiota in face of this constant threat. Intestinal macrophages and DCs integrate signals from the microenvironment to orchestrate innate and adaptive immune responses that ultimately lead to durable tolerance of the microbiota. Tolerance is not a default response, however, because macrophages and DCs remain poised to vigorously respond to pathogens that breach the epithelial barrier. In this review, we summarize the salient features of macrophages and DCs in the healthy and inflamed intestine and discuss how signals from the microbiota can influence their function.From birth, the mammalian intestine is colonized with a complex microbiota leading to a lifelong mutualistic relationship.¹ This diverse microbial population confers several evolutionary advantages to the host while simultaneously introducing a robust antigenic challenge that has the potential to initiate intestinal inflammation. Despite this threat, the host manages to maintain intestinal homeostasis via a sophisticated immune cell network that promotes tolerance to the microbiota while permitting responsiveness to invading pathogens.^2,3 Central to this discrimination process are intestinal antigen-presenting cells (APCs), predominantly composed of macrophages and dendritic cells (DCs), that are separated from the microbiota by a single layer of epithelial cells. Together, intestinal macrophages and DCs integrate cues from epithelial, immune, and stromal cells to direct innate and adaptive immunity.^4–10 Inappropriate responses to these signals can lead to a breakdown of tolerance toward the microbiota and culminate in uncontrolled inflammation, such as that observed in Crohn disease and ulcerative colitis.¹¹ This review will focus on the role of intestinal macrophages and DCs in the steady state and during inflammation, as well as how these cells interface with the microbiota.