丁苯酞对神经干细胞向神经细胞分化的促进作用

目的 研究丁苯酞通过PI3K-AKT信号通路促进神经干细胞向神经细胞分化的作用。方法 分离培养SD大鼠胚胎脑皮质层的神经干细胞,采用分化专用完全培养基培养后,通过光镜下观察和Nestin蛋白免疫荧光法进行鉴定。设置对照组和实验组,其中实验组添加丁苯酞辅助分化,分为丁苯酞低剂量组（1 μmol·L^-1）、中剂量组（5 μmol·L^-1）和高剂量组（10 μmol·L^-1）,作用24 h后,CCK-8法检测神经干细胞的细胞活力,碱性磷酸酶染色法检测神经干细胞的分化能力,免疫荧光法检测神经细胞分化程度,RT-qPCR法检测转录因子SOX2、PAX6和NeuN的mRNA表达水平,Western-blot及RT-qPCR检测PI3K-AKT信号通路的表达。结果 丁苯酞干预后神经干细胞活力提高,分化能力提高,碱性磷酸酶试验呈强阳性,转录因子SOX2、PAX6和NeuN的mRNA表达水平增高,PI3K-AKT信号通路蛋白和mRNA表达水平均增高,且呈现剂量依赖性。结论 丁苯酞可以促进神经干细胞向神经细胞分化,其作用机制可能与PI3K-AKT的激活有关。     

新生儿脐血与成人外周血细胞比较分析

目的:比较新生儿脐血与成人外周血细胞性质差异,为干细胞移植提供基础数据。方法:采用全自动血细胞仪对脐静脉血和成人外周血进行分析。结果:脐静脉血中有核细胞数目多,红细胞体积较大。结论:脐血里富含干细胞等原始细胞成分。     

Ricin Trafficking in Cells

The heterodimeric plant toxin ricin binds exposed galactosyls at the cell surface of target mammalian cells, and, following endocytosis, is transported in vesicular carriers to the endoplasmic reticulum (ER). Subsequently, the cell-binding B chain (RTB) and the catalytic A chain (RTA) are separated reductively, RTA embeds in the ER membrane and then retrotranslocates (or dislocates) across this membrane. The protein conducting channels used by RTA are usually regarded as part of the ER-associated protein degradation system (ERAD) that removes misfolded proteins from the ER for destruction by the cytosolic proteasomes. However, unlike ERAD substrates, cytosolic RTA avoids destruction and folds into a catalytic conformation that inactivates its target ribosomes. Protein synthesis ceases, and subsequently the cells die apoptotically. This raises questions about how this protein avoids the pathways that are normally sanctioned for ER-dislocating substrates. In this review we focus on the molecular events that occur with non-tagged ricin and its isolated subunits at the ER–cytosol interface. This focus reveals that intra-membrane interactions of RTA may control its fate, an area that warrants further investigation.     

灵芝多糖对肿瘤细胞与内皮细胞相互作用的影响

目的:研究灵芝多糖对肿瘤细胞与内皮细胞相互作用的影响。方法:应用免疫荧光法配合使用显微镜将内皮细胞区分出来后,通过MTT法观察灵芝多糖在内皮细胞增殖分化过程中的作用,并使用相同的方法观察肿瘤细胞的增殖分化过程与灵芝多糖的关系,同时观察灵芝多糖是否干扰2种细胞间产生的黏附作用及迁移反应。结果:内皮细胞的增殖分化过程与灵芝多糖不存在明显联系,肿瘤细胞的增殖分化过程与灵芝多糖也不存在明显联系,即无明显的细胞毒性反应。但灵芝多糖可阻碍2种细胞间产生的黏附作用和迁移反应,减少肿瘤细胞的迁移百分比。结论:灵芝多糖具有抗肿瘤功效,其作用机制为阻碍肿瘤细胞的黏附作用和迁移反应。     

不同来源间充质干细胞定向诱导为神经样细胞的研究

目的:比较不同来源间充质干细胞(MSCs)在体外定向分化为神经样细胞的能力。方法:无菌获取不同来源的MSCs并进行分组。A组:胎儿真皮;B组:胎儿骨髓;C组:成人骨髓。倒置显微镜下观察各组细胞形态并检测其倍增时间。流式细胞术检测各组MSCs的细胞表型和细胞周期。全反式维甲酸(ATRA)诱导各组MSCs在体外分化为神经样细胞,倒置相差显微镜观察神经样细胞的形态,免疫组织化学法和Western blot检测神经元特异性标志—神经丝蛋白(NF)和星形胶质细胞特异性标志—胶质纤维酸性蛋白(GFAP)的表达。结果:不同来源的MSCs具有相似的细胞形态、细胞表型和细胞周期,但是C组MSCs的增殖能力及体外传代能力低于A组和B组。不同来源、不同扩增代数的MSCs在诱导剂的作用下呈现典型的神经样细胞的形态,免疫组织化学显示,NF和GFAP均呈阳性反应。结论:不同来源的MSCs均可以在体外分化为神经样细胞,但不同发育阶段的MSCs体外分化为神经样细胞的能力存在差异。     

Morphologic Evidence of Anti-Tumor Specificity of T Cells Activated by Denritic Cells Derived from Peripheral Blood Mononuclear Cells of Thyroid Cancer Patients

Recent studies suggest that immunization with autologous dendritic cells (DCs) results in protective immunity and rejection of established tumors in various human malignancies. The purpose of this study is to determine whether DCs are generated from peripheral blood mononuclear cells (PBMNs) by using cytokines such as F1t-3 ligand (FL), granulocyte macrophage-colony stimulating factor (GM-CSF), IL-4, and TNF-α, and whether cytotoxic T cells activated against the thyroid cancer tissues by the DCs. Peripheral blood was obtained from 2 patients with thyroid cancer. DCs were established from PBMNs by culturing in the presence of FL, GM-CSF, IL-4, and TNF-α for 14 days. At day 14, the differentiated DCs was analyzed morphologically. The immunophenotypic features of DCs such as CDla, CD83, and CD86 were analyzed by immunofluorelescence microscopy. At day 18, DCs and T cells were incubated with thyroid cancer tissues or normal thyroid tissues for additional 4 days, respectively. DCs generated from the PBMNs showed the typical morphology of DCs. Activated cytotoxic T lymphocytes (CTLs) were observed also. DCs and the CTLs were attached to the cancer tissues on scanning electron microscope. The DCs activated the CTLs, which able to specifically attack the thyroid cancer. This study provides morphologic evidence that the coculture of T cells/cancer tissues activated the T cells and differentiated CTLs. The CTLs tightly adhered to cancer tissues and lysed cancer tissues vigorously. Therefore DCs could be used as potential vaccines in the immunotherapy.     

Effect of Low Dose Radiation on Differentiation of Bone Marrow Cells into Dendritic Cells

Low dose radiation has been shown to be beneficial to living organisms using several biological systems, including immune and hematopoietic systems. Chronic low dose radiation was shown to stimulate immune systems, resulting in controlling the proliferation of cancer cells, maintain immune balance and induce hematopoietic hormesis. Since dendritic cells are differentiated from bone marrow cells and are key players in maintaining the balance between immune activation and tolerance, it may be important to further characterize whether low dose radiation can influence the capacity of bone marrow cells to differentiate into dendritic cells. We have shown that bone marrow cells from low dose-irradiated (γ-radiation, 0.2Gy, 15.44mGy/h) mice can differentiate into dendritic cells that have several different characteristics, such as expression of surface molecules, cytokine secretion and antigen uptake capacity, when compared to dentritic cells differentiated from the control bone marrow cells. These differences observed in the low dose radiation group can be beneficial to living organisms either by activation of immune responses to foreign antigens or tumors, or maintenance of self-tolerance. To the best of our knowledge, this is the first report showing that total-body low dose radiation can modulate the capacity of bone marrow cells to differentiate into dendritic cells.     

奈韦拉平对HeLa细胞端粒酶活性和细胞周期的影响

目的研究奈韦拉平(nevirapine,NVP)对HeLa细胞端粒酶活性和细胞周期的影响.方法采用TRAP-PCR-ELISA方法检测HeLa细胞在奈韦拉平作用后端粒酶活性的变化,用流式细胞仪分析细胞周期的改变.结果NVP作用后,HeLa细胞端粒酶活性明显抑制(P＜0.05),并且HeLa细胞的G2/M期细胞含量明显增高(P＜0.01).结论NVP对肿瘤细胞的端粒酶活性有抑制作用.     

人参皂苷Rb1拮抗达沙替尼抑制NK细胞杀伤卵巢癌的研究

目的研究抗癌药达沙替尼对自然杀伤细胞（NK细胞）杀伤卵巢癌细胞的抑制效应,并探讨人参皂苷Rb1拮抗这种免疫抑制效应的作用及其分子机制。方法分别用达沙替尼、人参皂苷Rb1以及达沙替尼联合人参皂苷Rb1预处理NK细胞,未经药物处理的NK细胞设为对照。采用CFSE／PI双染色法,经流式细胞仪检测与NK细胞混合培养的卵巢癌HO-8910细胞的死亡率来明确NK细胞的杀伤功能;采用Annexin V-FITC／PI双染色法测定NK细胞的凋亡率来明确其生存活力;采用real-timePCR法测定NK细胞颗粒酶B的mRNA表达量;采用免疫印迹法检测NK细胞ERK的蛋白水平。结果与对照组相比,达沙替尼处理组的NK细胞对卵巢癌HO-8910细胞的杀伤率显著下降（P〈0．01）,NK细胞的颗粒酶B的mRNA水平和磷酸化ERK（pERK）表达均下调;达沙替尼合并人参皂苷Rb1处理组的NK细胞对卵巢癌HO-8910细胞的杀伤率较达沙替尼组升高（P〈0．05）,而且颗粒酶B的mRNA水平、pERK表达均较达沙替尼组有所恢复;与对照组相比,人参皂苷Rb1单独处理组的NK细胞的生存活力、颗粒酶B水平、pERK表达量以及杀伤功能均无显著差异（P〈0．05）。结论达沙替尼对NK细胞杀伤卵巢癌细胞有抑制效应,可能与下调NK细胞的杀伤介质颗粒酶B和抑制ERK磷酸化有关。人参皂苷Rb1虽然不能直接活化NK细胞,但是能拮抗达沙替尼对NK细胞的上述抑制效应,提示联用人参皂苷Rb1能减少抗癌药物达沙替尼对免疫效应细胞的抑制作用。     

Targeting Vaccines to Dendritic Cells

Dendritic cells (DC) are specialized antigen presenting cells (APC) with a remarkable ability to take up antigens and stimulate major histocompatibility complex (MHC)-restricted specific immune responses. Recent discoveries have shown that their role in initiating primary immune responses seems to be far superior to that of B-cells and macrophages. DC are localized at strategic places in the body at sites used by pathogens to enter the organism, and are thereby in an optimal position to capture antigens. In general, vaccination strategies try to mimic the invasiveness of the pathogens. DC are considered to play a central role for the provocation of primary immune responses by vaccination. A rational way of improving the potency and safety of new and already existing vaccines could therefore be to direct vaccines specifically to DC. There is a need for developing multifunctional vaccine drug delivery systems (DDS) with adjuvant effect that target DC directly and induce optimal immune responses. This paper will review the current knowledge of DC physiology as well as the progress in the field of novel vaccination strategies that directly or indirectly aim at targeting DC.     

胰腺干细胞研究进展

目的 糖尿病是危害人类健康的主要疾病之一,传统治疗如药物和外源性胰岛素替代疗法存在很多问题,胰岛移植在糖尿病的治疗上取得一定效果,但存在供体缺乏和移植细胞增殖困难等问题.近年来随着干细胞及生物医学工程的迅猛发展,作为糖尿病胰岛替代疗法胰腺干细胞已成为研究的热点,为糖尿病的治疗带来光明前景.本文就胰腺干细胞的分类、分离及鉴定进行综述.     

Chemical Toxicity on HeLa Cells

HeLa cells were named for Henrietta Lacks, who died in 1952 from an infection of a special type of cancer. Margaret Gey, her physician, started working with these cancer cells that are still used for medical research. In the present review, an attempt has been made to collect the data for the effects of different chemicals on HeLa cells and to discuss them by the formulation of a total number of 22 QSAR.     

噻替派(Thiotepa)滴眼液对人癌细胞和正常细胞的细胞毒作用

目的 了解0.05%Thiotepa滴眼液对各种不同的人癌细胞和正常细胞生长的影响.方法 采用四甲基偶氮唑蓝(MTT)法进行体外细胞毒试验,测定Thiotepa滴眼液对人癌细胞和正常细胞的生长抑制作用,以半数抑制浓度(IC50值)进行评价.结果 Thiotepa滴眼液在50μg/ml～0.78μg/ml浓度下对人癌细胞Glc-82、K-562、Bel-7402、Hela和CNE2的IC50值依次为:22.7μg/ml、10.6μg/ml、15.3μg/ml、11.2μg/ml和9.6μg/ml.对人正常细胞Hk-293、ECV-304、HRPE、Fibro和小鼠3T3细胞的IC50值分别为:1.4μg/ml、12.5μg/ml、17.8μg/ml、36.6μg/ml和14.4μg/ml.结论 Thiotepa滴眼液对各种细胞有明显的生长抑制作用;0.05%Thiotepa滴眼液对各种人癌细胞和正常细胞均有强的细胞毒作用,且对人癌细胞无明显的选择性抑制作用.     

细胞放射生物学参数的分析

目的通过测定鼻咽癌HNE1细胞株和HNE1-O(将空载体质粒pEGFP-N1转染到鼻咽癌细胞HNE1)的放射生物学参数,解决生物医学研究中放射剂量-存活曲线的拟合问题,给予统计软件技术上的支持。方法采用细胞转染技术,将空载体质粒pEGFP-N1转染到鼻咽癌细胞HNE1细胞株,荧光显微镜下观察结果。克隆形成实验测定HNE1和HNE1-O两组细胞在不同剂量照射下的存活分数。采用SPSS实现单击多靶模型和线性二次函数模型拟合细胞存活曲线,求出放射生物学参数D0、Dq、N和α、β、α/β、SF2值。结果分别对2种常用放射剂量-存活曲线的生物物理模型,给出曲线拟合的SPSS程序,并进行实例分析,估计相应的模型参数。结论给出的SPSS程序适用于放射剂量存活曲线的拟合。为基因治疗及细胞放射敏感性研究奠定理论和技术基础。     

Feridex标记胎盘来源的间充质干细胞分化为神经干细胞的实验研究

目的分离胎盘组织来源的间充质干细胞并诱导分化为神经干细胞,以期找到能成功标记神经干细胞的方法。方法将胎盘组织剪碎后消化、培养,加入神经干细胞诱导因子10ng/mL表皮生长因子（EGF）＋10ng/mL重组人碱性成纤维生长因子（bFGF）＋DMEM/F12,并分别添加相应浓度的血清,预诱导3d后加入DMEM/F12＋0.1μmol/L全反式维甲酸（RA）,10ng/mL胶质细胞系源性神经营养因子（GDNF）＋10ng/mL脑源性神经营养因子（BDNF）进行正式诱导7d。结果诱导10d后用Feridex标记诱导后的细胞,普鲁士蓝染色显示90%以上的干细胞胞质内出现细小的蓝色铁颗粒,Nestin染色显示阳性。结论胎盘来源的间充质干细胞能成功诱导为神经干细胞,且Feridex可成功标记诱导后的细胞。