基于Nrf2信号通路探讨异甘草酸镁对雷公藤甲素损伤L-02细胞中相关蛋白表达的影响

目的基于Nrf2-ARE信号通路探讨异甘草酸镁对雷公藤甲素损伤L-02细胞的保护作用及相关机制。方法体外培养正常人肝L-02细胞,通过免疫荧光技术检测异甘草酸镁(60μmol·L^-1)对雷公藤甲素(80nmol·L^-1)损伤L-02细胞中Nrf2核转移的影响;采用Western blotting测定细胞核中Nrf2及细胞中细胞色素P450 3A4(CYP3A4)、多药耐药相关蛋白2(multidrug resistance associated protein 2,MRP2)和胆盐输出泵(bile salt export pump,BSEP)的蛋白表达。结果雷公藤甲素对L-02细胞核中Nrf2具有诱导作用(P<0.01),并促进Nrf2核内转移;异甘草酸镁预处理组较雷公藤甲素组降低L-02细胞核中Nrf2的表达(P<0.01);异甘草酸镁预处理后对雷公藤甲素损伤L-02细胞中CYP3A4、MRP2和BSEP蛋白表达具有诱导作用(P<0.01)。结论异甘草酸镁可减轻雷公藤甲素对L-02细胞造成的损伤作用,其机制可能与诱导细胞核中Nrf2以及细胞中CYP3A4、MRP2和BSEP受体有关。     

雷公藤甲素对Caspase诱导人肝细胞L-02凋亡机制的研究

目的：研究雷公藤甲素诱导正常人肝细胞株L-02细胞凋亡的机制。方法：体外培养L-02细胞。MTT法检测雷公藤甲素的细胞毒性作用;Annexin V-FITC/PI双染法检测雷公藤甲素对L-02细胞的凋亡诱导作用;测定细胞基质中半胱天冬氨酸酶（Caspase）8、Caspase9与Caspase3活性的变化及加入Caspase抑制剂Z-DEVD-FMK后对细胞凋亡的影响。结果：雷公藤甲素能显著诱导L-02细胞的凋亡,其作用呈明显的量效关系与时间依赖性;120nmol·L-1雷公藤甲素作用L-02细胞24h使Caspase3的活性显著增强;加入Z-DEVD-FMK后,能有效抑制雷公藤甲素诱导的细胞凋亡。结论：雷公藤甲素体外诱导正常人肝细胞株L-02细胞凋亡可能与上调Caspase3、9的活性有关。     

雷公藤甲素单次及多次给药对大鼠肝药酶活性的影响

目的:研究雷公藤甲素对大鼠肝药酶活性的影响。方法:对SD大鼠以雷公藤甲素(150、300、450μg·kg-1)灌胃给药,每天1次,给药1d或14d,分别测定细胞色素P450、细胞色素b5含量及红霉素N-去甲基酶(ERD)、二甲基亚硝胺脱甲基酶(NDMA)、甲氧基异唑脱甲基酶(MROD)、乙氧基异唑脱乙基酶(EROD)和戊氧基异唑脱烷基酶(PROD)活性;CYP3A和CYP2E1蛋白含量采用Westernblotting法分析。结果:单次灌胃雷公藤甲素对肝药酶活性及CYP2E1、CYP3A蛋白表达基本无影响;多次给予雷公藤甲素(450μg·kg-1,14d)能诱导NDMA活性,抑制ERD活性,轻度升高CYP2E1蛋白表达,显著降低CYP3A蛋白表达。结论:长期较高剂量给予雷公藤甲素能抑制CYP3A活性,轻度诱导CYP2E1活性。     

雷公藤甲素对人肝细胞L-02氧化损伤的初步研究

目的 研究雷公藤甲素对正常人肝细胞株L-02细胞凋亡和活性氧生成的影响.方法 体外培养L-02细胞,MTT法检测雷公藤甲素对L-02细胞的毒性作用,H2DCFH-DA探针流式细胞仪检测细胞中ROS生成量,并测定细胞SOD活性、MDA含量及LDH释放量的变化.结果 雷公藤甲素诱导L-02细胞中ROS生成,且随时间的延长而增多,至12h时达峰值(P＜0.01);同时,雷公藤甲素也能诱导细胞中MDA含量及LDH释放量的增加,诱导SOD活性的降低.结论 雷公藤甲素体外诱导人正常肝细胞L-02细胞凋亡可能与其促进活性氧生成有关.     

雷公藤甲素诱导肝细胞L-02凋亡的机制

目的:探讨雷公藤甲素对人正常肝细胞L-02细胞的凋亡诱导作用及细胞线粒体呼吸链复合体抑制剂对细胞凋亡的影响。方法:采用Annexin V-FITC/PI双染色法检测雷公藤甲素对L-02细胞的凋亡作用,JC-1染色观察细胞线粒体膜电位的变化,线粒体呼吸链复合体抑制剂对细胞活性氧释放及细胞凋亡的影响。结果:流式细胞仪检测结果显示,雷公藤甲素对细胞增殖的抑制作用与浓度、时间呈正相关;JC-1染色可见经雷公藤甲素作用的细胞线粒体膜电位降低;加入细胞线粒体呼吸链抑制剂后,与单用雷公藤甲素组比较,雷公藤甲素+rotenone组细胞活性氧释放水平显著降低(P<0.05),同时抑制剂合用组细胞凋亡百分率显著降低(P<0.05)。结论:雷公藤甲素体外可诱导L-02细胞凋亡,机制可能是与公藤甲素上调经线粒体呼吸链复合体Ⅰ、Ⅲ产生的活性氧有关。     

丙戊酸钠及其代谢产物的体外肝毒性研究

目的 研究丙戊酸钠及3个代谢产物（2-丙基-4-五烯酸、3-羟基丙戊酸、5-羟基丙戊酸）对体外人正常肝细胞L02增殖活性及对肝细胞损伤相关指标的影响。方法 实验分为对照组和实验组,对照组细胞常规培养,实验组加入丙戊酸钠及3个代谢产物,采用CCK-8法检测细胞增殖活性,PCR法检测CYP1A1、CYP1A2、PCNA、Bax及Bcl-2的mRNA相对含量,Western Blotting法检测蛋白表达,同时检测细胞上清液中谷草转氨酶（AST）、谷丙转氨酶（ALT）、乳酸脱氢酶（LDH）的含量。结果 与对照组相比,随着丙戊酸钠及3个代谢产物浓度和时间的增加,对 L02细胞增殖活性的抑制逐渐增强,CYP1A1、CYP1A2及Bax的mRNA相对含量和蛋白表达量升高,PCNA及Bcl-2的 mRNA相对含量和蛋白表达量均有下降,AST、ALT、LDH含量升高。结论 丙戊酸钠及3个代谢产物与肝毒性有关。     

人脂联素基因在L-02细胞中表达及其功能检测

目的:在人正常肝细胞株L-02中表达外源人脂联素蛋白,并观察其生物学活性。方法:采用脂质体法将成功构建的人脂联素真核表达质粒pcDNA3.1/CT-GFP-TOPO-Adiponectin转染L-02细胞;免疫组织化学定位观察脂联素的表达;Western blot检测培养上清及细胞沉淀中脂联素水平;酶联免疫法测定培养基血糖。结果:构建的真核表达质粒能有效转染L-02细胞,并在培养上清及细胞沉淀中检测到脂联素蛋白,该重组蛋白能够降低高糖处理的L-02细胞的血糖水平。结论:重组人脂联素蛋白能在L-02中有效表达,该蛋白定位在细胞质,并且能分泌到胞外,表达产物经体外实验证实具有生物学活性。     

雷公藤甲素对人肺腺癌A549细胞增殖和凋亡的影响

目的：研究雷公藤甲素对人肺腺癌‰细胞增殖和凋亡的影响。方法：采用MTT实验检测雷公藤甲素对体外培养的人肺腺癌A谢细胞增殖的影响，运用流式细胞术、基因组DNA电泳观察凋亡特征性“梯状”条带检测细胞凋亡，采用caspase活性定量检测试剂盒分析caspase-9，3的活化。结果：雷公藤甲素对体外培养的A谢细胞具有明显的抑制作用。流式细胞仪检测显示雷公藤甲素可以显著诱导‰细胞凋亡，DNA电泳显示雷公藤甲素作用于A谢细胞后出现凋亡细胞特有的DNA阶梯状条带。雷公藤甲素作用后‰细胞caspase-9，caspase-3活性明显升高。结论：雷公藤甲素可能通过线粒体信号通路抑制肺腺癌A谢细胞的生长并诱导其凋亡。     

海兔素对大鼠原代肝细胞酒精性氧化损伤的保护作用

目的探讨海兔素对大鼠原代肝细胞酒精性氧化损伤保护作用。方法门静脉胶原酶Ⅳ原位灌注及密度梯度离心获得大鼠原代肝细胞。MTT实验检测乙醇和海兔素最佳作用剂量及肝细胞活力。酶学实验检测细胞AST、LDH、SOD、MDA、GSH水平;流式细胞术检测细胞凋亡情况;单细胞凝胶电泳观察细胞DNA损伤状况;JC-1荧光探针检测细胞线粒体膜电位水平;比色法及Western blot检测细胞CYP2E1活性及蛋白表达。结果经30 mg·L~(-1)。海兔素预作用2 h,再与300 mmol·L~(-1)。乙醇共作用8 h后,肝细胞活力较酒精模型组明显上升,AST和LDH释放也得到明显抑制;同时,肝细胞SOD和GSH水平明显升高,MDA含量则明显降低,差异均具有显著性(P<0.05)。海兔素干预后,肝细胞凋亡率明显降低,DNA损伤及线粒体膜电位水平明显得到改善。海兔素干预后,肝细胞CYP2E1活性及蛋白表达水平明显受到抑制(P<0.05)。结论海兔素对大鼠原代肝细胞酒精性氧化损伤具有保护作用,其作用机制可能与海兔素抑制酒精对CYP2E1的活化,缓解氧化应激,提高机体抗氧化能力有关。     

胶原夹心培养大鼠肝细胞及其细胞色素P450酶活性的测定

目的　自制大鼠尾腱Ⅰ型胶原培养原代大鼠肝细胞 ,测定肝细胞中细胞色素P450 (cytochromeP450 ,CYP)酶活性。方法　制备无菌大鼠尾腱Ⅰ型胶原 ,比较单层胶原铺底法 (collagencoated ,CC)及胶原夹心法 (collagensandwichsys tem ,CSS)培养大鼠肝细胞的生长及功能维持情况。CSS法培养肝细胞 ,分别加入泼尼松龙 (10 0 μmol·L- 1,3d)、尼莫地平 (50 μmol·L- 1,2d)和利福平 (50 μmol·L- 1,2d) ,测定CYP1A、CYP2E1及CYP3A酶活性。结果　CSS法培养 6d后 ,肝细胞生长良好。CC法培养 3d后细胞开始脱落 ,此后持续增多 ;6d后 ,培养上清液中ALT、AST与LDH活性升高 ,均高于同期CSS法培养细胞上清液中的水平。加入经CYP3A代谢药物 ,CSS培养肝细胞CYP1A活性无明显改变 ;尼莫地平使CYP3A活性升高 3 3 % ,而CYP2E1活性下降 45% (P <0 0 5) ;利福平使CYP3A活性升高为对照组的1 94倍 (P <0 0 5) ,对CYP2E1活性无作用。结论　同为CYP3A底物 ,泼尼松龙、尼莫地平和利福平对CYP亚型的影响不同 ,但不改变肝细胞CYP1A对致癌物的活化。CSS培养法可作为体外模型用于药物代谢研究     

树突状细胞对肿瘤细胞株的直接杀伤活性

目的 对比分析干扰素－γ（Interferon-γ,IFN-γ)或脂多糖（lipoplysaccharide,LPS)刺激后的树突状细胞（dendritic cell,DC)对肿瘤细胞杀伤活性的差异。方法 分离健康供者外周血单核细胞，用粒单细胞集落刺激因子和白介素－4诱导为DC。于培养液中加入LPS或IFN－γ培养12h，作为LPS激活的DC（LPS－DC）及IFN－γ激活的DC（IFN－DC）。用流式细胞仪检测DC表面共刺激分子的改变，以明确LPS或IFN－γ对DC的不同刺激作用；同时，以恶性血液病细胞株HL－60 Jurkat及Daudi为靶细胞，用不同效靶比与DC共同培养18h，采用^51Cr释放试验检测LPS－DC及IFN－DC抗肿瘤活性的差异。结果 ①LPS及IFN－γ可不同程度的上调DC表面CD86、CD80、CD83及CD1a的表达，以LPS刺激组明显。②IFN－γ和LPS可分别增强DC对HL60及Daudi的杀伤活性，在效靶比为20：1及10：1时杀伤率与未加刺激因子对照组（medium-DC)相比差异有显著意义（P＜0．05）。相反，IFN－γ－DC对Daudi、LPS－DC对HL－60无明显杀伤活性，但两者对Jurkat均具杀伤作用。结论 LPS及IFN－γ激活的DC对肿瘤细胞的杀伤活性具有相对肿瘤特异性。     

Nitric oxide, cell signaling and cell death

Nitric oxide (NO) is an important bioregulatory molecule in the nervous, immune and cardiovascular systems. NO participates in the regulation of the daily activities of cells as well as in cytotoxic events. It possesses a controversial effect on cell viability by acting both as a protection against apoptogenic stimuli, or by inducing apoptosis when produced at elevated concentrations. The mechanisms of NO in regulating these biological functions can be either through cyclic guanylate cyclase (cGMP)-dependent or cGMP-independent pathways. The purpose of this review is to highlight the implication of NO in cell signalling, synaptic transmission, and cell death. We focus also on the protective role as well as the toxicity of NO. Finally, the adverse effects of inhaled nitric oxide are also depicted in this review.     

Mast cell regulatory effect on lymphoid cell proliferation.

It has been shown rat mast cells (MC) can modulate lymphocyte proliferation in vitro. Depending on concentrations tested both serosal MC and their supernatants enhanced the spontaneous and T-mitogen-induced proliferation of spleen and lymph node cells. In addition T-mitogen-induced thymocyte proliferation was also increased. The enhancing effect of MC on lymphoid cell proliferation appeared after MC and lymphocytes were cocultured for 24, 48 or 72 h. The highest enhancing action of MC was observed when MC and lymphocytes were plated simultaneously. In contrast, when MC were added 24 or 48 h after the start of lymphocyte culture, the enhancing action of MC decreased or was abolished, respectively. No dependence was found between histamine concentration in MC supernatants and the enhancing activity of supernatants. After chromatographic separation of MC supernatants the fractions with molecular weights between 1-6 KDa augmented lymphoid cell proliferation.     

Pharmacotherapy for treating metastatic clear cell renal cell carcinoma

Introduction: Over the past decade metastatic renal cell carcinoma (RCC) treatment landscape has dramatically evolved from the era of cytokines-based immunotherapy (which benefited very few patients, at the expenses of high toxicities) to the present era of targeted agents and novel immunotherapeutics, greatly improving the prognosis of our patients.

Areas covered: Here we have reviewed the present status of the medical treatment of metastatic RCC. To do this, we interrogated the Medline database, as well as the proceedings of the main Oncological and Urological conferences for the relevant trials coducted so far.

Expert opinion: Despite all the advances made in these relatively few years, further improvements are needed, since none of the available agents proved able to cure even a sigle metastatic RCC patient. In particular, advances are awaited from the results of ongoing trial of combinations of different immune checkpoint inhibitors and of immune checkpoint inhibitors with anti-VEGF/VEGFRs agents. Furthermore, a better understanding of the molecular escape pathways used by the tumor to overcome VEGFR blockade or immune activation will hopefully bring soon to the clinic more active, tailored treatments, to be used in second line and beyond.     

Rapid fluorometric assay for cell viability and cell growth using nucleic acid staining and cell lysis agents

The purpose of this study was to establish a new method for rapidly and simply assessing cell viability and growth with objective validation if the assay system proceeded under suitable conditions of cell culture. In this method, a cell lysis agent was combined with a fluorescent probe for nucleic acid which exclusively passes through the disrupted membranes of dead cells but not intact membranes of viable cells. The distinctive feature of this probe is to possess a large fluorescence enhancement (460-fold) on binding to nucleic acid despite very low intrinsic fluorescence. In this fluorometric assay based on cell lysis and staining (FACLS), the fluorescence intensity was linearly related to total tumour cell number. This FACLS was also used to evaluate the chemosensitivity of MOLT-4 human leukaemia cells and to measure cell viability. The results were similar to those obtained by MTT colorimetric and trypan blue exclusion assays. The main advantage of this assay is its ability to measure simultaneously both cell viability and cell growth rapidly (within about 5 min) and simply (two steps) with validation of cell culture conditions in each microplate. This method could be widely applicable to cytotoxic evaluation of anticancer drugs and other chemicals.     

T cell targeted immune enhancement yields effective T cell adjuvants

Given the critical role of cell-mediated immunity (CMI) in defense against attack from pathogens that establish chronic infections, it has become abundantly clear that current vaccine methodology will not be sufficient to develop the appropriate immune response for protection and/or clearance of infection. By extension, this logic also applies to cancer vaccines where T cell immune-mediated destruction is a critical mechanism for control of the disease. This review describes our current thoughts on the events associated with immune activation and evaluates the various approaches to achieve successful immune activation with defined or targeted antigens as opposed to using inactivated or attenuated organisms. The advantages and disadvantages of the current adjuvants for antigens that focus on mimicking the infection events via the innate immune system or antigen uptake are described in the context of generation of T cell specific responses. A central theme of the discussions is the importance of cytokines in modulating the immune response towards T cell immunity, either by adjuvant modulation or use of natural cytokine mixtures targeted towards the site of immune activation. Also discussed is the possibility that thymomimetic agents such as thymosin alpha1, levamisole and methyl inosine monophosphate (MIMP) may be useful in enhancing the T cell mediated arm of the immune response.     

Stem cell pharmacogenomics

Therapeutic stem cell applications represent a newly evolving approach for the treatment of several genetic and degenerative diseases. The advent of pharmacogenomics too, holds promise for an individualized, optimal treatment regime for a large variety of medical conditions. A combination of the benefits of these two technologies creates a new niche in therapeutic medicine research viz. that of stem cell pharmacogenomics (SCP). The development of this approach requires the application of existing technologies in genomics, proteomics and bioinformatics to resolve the various issues involved in advancing the therapeutic applications of stem cell medicine. In this brief overview of the subject, we attempt to provide fresh insights into the exclusive niche of stem cell pharmacogenomics and discuss some of the priority issues that need to be targeted, based on the existing principles of pharmacogenomics, stem cell characteristics and transplantation medicine. Advances in these areas are imperative in realizing the dream of stem cell therapies contributing towards the improvisation of the quality of human life.