神经核蛋白γ（γ-syn）在直肠癌组织中表达的研究

目的研究直肠癌组织中γ-syn蛋白的表达情况。方法免疫组织化学法检测86例直肠癌组织γ-syn蛋白的表达。同时收集临床资料,包括年龄、性别、肿瘤距肛门距离、术前血清CEA水平、肿瘤分化程度、有无淋巴结转移。结果86例直肠癌组织中都有γ-syn蛋白的表达（86／86）。γ-syn蛋白的表达与患者性别、年龄、肿瘤距肛门距离、术前血清CEA水平之间无相关性;与直肠癌的组织分化程度、有无淋巴结转移无关。绪论直肠癌组织高表达γ-syn蛋白;γ-syn蛋白是直肠癌普遍存在表达的蛋白,可以作为直肠癌的生物标记。     

Immunotherapy with Agonistic Anti-CD137： Two Sides of a Coin

CD137 (4-1BB),a member of the TNF receptor superfamily,is an inducible T cell costimulatory receptorprimarily expressed on activated CD4~+ and CD8~+ T cells.Agonistic monoclonal antibodies (mAbs) against CD137greatly enhance T cell-mediated immune responses against many types of tumors and viruses.Surprisingly,theseagonists also showed therapeutic effects in several autoimmune diseases.These findings suggest that in differentdisease environments,CD137 engagement with agonist mAb in vivo can diametrically modulate immuneresponse outcomes.Therefore,CD137 agonists represent a promising immunotherapeutic approach to a widearray of disparate immune disorders.However,CD137's potency in modulating immune response necessitatescaution when targeting CD137 clinically.Cellular & Molecular Immunology.2004;1(1):31-36.     

Functional expression of 4-1BB (CD137) in the inflammatory tissue in Crohn's disease

4-1BB ligand (L) expressed on antigen presenting cells (APC) interacts with 4-1BB, expressed on activated T cells and this interaction costimulates T cells to secrete cytokines and to proliferate. We investigated whether 4-1BB/4-1BBL interactions might be involved in the pathogenesis of Crohn's disease (CD). In immunohistochemistry, we found 4-1BB expression on lamina propria (LP) cells in inflamed and to a lesser extend in non-inflamed gut tissue from CD patients. mRNA levels for 4-1BB were also elevated in intestinal CD tissue. In contrast, only few 4-1BB-expressing cells were found in inflamed tissue from ulcerative colitis (UC) patients and almost no positive cells were found in control intestinal tissue. 4-1BB expression was better sustained on in vitro activated lamina propria T cells from CD patients compared to controls. Finally, agonistic anti-4-1BB antibody enhanced interferon-gamma (IFN-gamma) production and proliferation of lamina propria T cells from CD patients. Taken together, our data suggest that 4-1BB/4-1BBL interactions contribute to the persistence of gut inflammation in CD.     

Human multiple myeloma cells express peroxisome proliferator-activated receptor gamma and undergo apoptosis upon exposure to PPARgamma ligands

Multiple myeloma is essentially an incurable malignancy and it is therefore of great interest to develop new therapeutic approaches. We previously reported that human B cell-lymphomas express the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARgamma) and are killed by PPARgamma ligands. Herein, we investigate the therapeutic potential of PPARgamma ligands for multiple myeloma. The human multiple myeloma cell lines ANBL6 and 8226 express PPARgamma mRNA and protein. The PPARgamma ligands, 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2) and ciglitazone, induced multiple myeloma cell apoptosis as determined by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay, loss of mitochondrial membrane potential, and caspase activation. Importantly, the ability of PPARgamma ligands to kill both multiple myeloma cell lines was not abrogated by Interleukin-6 (IL-6), a multiple myeloma growth survival factor. Finally, the RXR ligand 9-cis retinoic acid (9-cis RA) in combination with PPARgamma ligands greatly enhanced multiple myeloma cell killing. These new findings support that PPARgamma ligands may represent a novel therapy for multiple myeloma.     

Neurotransmitter segregation: functional and plastic implications

Synaptic cotransmission is the ability of neurons to use more than one transmitter to convey synaptic signals. Cotransmission was originally described as the presence of a classic transmitter, which conveys main signal, along one or more cotransmitters that modulate transmission, later on, it was found cotransmission of classic transmitters. It has been generally accepted that neurons store and release the same set of transmitters in all their synaptic processes. However, some findings that show axon endings of individual neurons storing and releasing different sets of transmitters, are not in accordance with this assumption, and give support to the hypothesis that neurons can segregate transmitters to different synapses. Here, we review the studies showing segregation of transmitters in invertebrate and mammalian central nervous system neurons, and correlate them with our results obtained in sympathetic neurons. Our data show that these neurons segregate even classic transmitters to separated axons. Based on our data we suggest that segregation is a plastic phenomenon and responds to functional synaptic requirements, and to 'environmental' cues such as neurotrophins. We propose that neurons have the machinery to guide the different molecules required in synaptic transmission through axons and sort them to different axon endings. We believe that transmitter segregation improves neuron interactions during cotransmission and gives them selective and better control of synaptic plasticity.     

转化生长因子β1对香烟诱导的大鼠肺泡巨噬细胞γ-谷氨酰半胱氨酸合酶表达的影响

目的：探讨转化生长因子（TGF）-β1对香烟诱导的大鼠肺泡巨噬细胞γ-谷氨酰半胱氨酸合酶（γ-GCS）和活化蛋白(AP)-1亚单位c-fos mRNA及其蛋白表达的影响。方法:通过支气管肺泡灌洗获取大鼠肺泡巨噬细胞，随机分为对照组、香烟组和TGF-β1组。TGF-β1组加入终浓度为3 μg/L的TGF-β1,2 h后除对照组外，余2组均加入香烟烟雾提取物,对照组加入磷酸盐缓冲液。分别用逆转录聚合酶链式反应（RT-PCR）和免疫细胞化学方法检测肺泡巨噬细胞中γ-GCSh(重链亚单位)及c-fos mRNA和蛋白的表达。结果:香烟组γ-GCSh和c-fos mRNA及其蛋白表达水平显著高于对照组(分别P<0.05,P<0.01)。TGF-β1组γ-GCSh mRNA及其蛋白表达水平明显低于香烟组(均P<0.01)；而c-fos mRNA及其蛋白表达水平明显高于香烟组(均P<0.01)。结论:转化生长因子-β1参与香烟所致慢性阻塞性肺疾病肺氧化/抗氧化失衡的发病机制。     

抗纤维化细胞因子对TGF-β1基因启动转录活性的影响

转化生长因子β1(transforming growth factor-β1)是一类现已明确的致纤维化细胞因子,具有广泛的生物学效应,对细胞外基质(ECM)基因表达、降解、细胞增殖分化、凋亡及免疫功能都具有重要调节作用。前期我们研究发现,TGF-β1启动调控序列中单核苷酸多态性(single nucleotide polymorphism,SNP)位点-509C>T与肝纤维化进展及血浆中TGF-β1浓度有明显的相关性。本研究旨在探讨抗纤维化细胞因子(IL-10、HGF、IFN-γ)对含TGF-β1基因-509C>T启动调控序列活性的影响。我们以特定-509C>T基因型患者DNA为模板,用PCR方法扩增得到一对长度为2.14kb(-1328~+812)含有-509C>T变异的TGF-β1上游基因片段,并将其与不含启动子的pCAT3-enhancer报告基因载体重组,构建重组体phT-GF2.14C和phTGF2.14T。用脂质体转染法将两种重组体分别转染至正常人肝脏细胞中,分别用IL-10(4ng/ml)、HGF(10ng/ml)、IFN-γ(20ng/ml)干预转染后细胞。ELISA法测定转染细胞的报告基因CAT活性。结果表明:肝细胞转染重组体phTGF2.14C细胞的CAT活性明显高于转染重组体phTGF2.14T(t=12.5882,P=0.0002)。IFN-γ对TGF-β1基因启动子phTGF2.14C、phTGF2.14T均具有显著抑制作用。细胞因子IL-10和HGF对其调控作用不显著。TGF-β1基因-509C>T中C等位基因可明显增强TGF-β1基因上游启动调控序列的转录活性,IFN-γ作为一种抗纤维化细胞因子在基因转录水平对含有两种等位基因-509C>T的TGF-β1基因上游启动调控序列均具有抑制作用。而作为抗纤维化细胞因子的IL-10与HGF在2.14Kb(-1328~+812)区域内对TGF-β1基因上游启动调控序列的作用不显著。     

携带mIFN-γ的溶瘤病毒CNHK300-mIFN-γ对肿瘤细胞的体外杀伤作用

目的: 研究携带小鼠干扰素γ(mIFN-γ)基因的溶瘤病毒CNHK300-mIFN-γ(CNHK300-Mγ)对恶性肿瘤细胞的体外杀伤作用。方法: CNHK300-Mγ、CNHK300、ONYX-015和AdEasy-mIFN-γ(AdEasy-Mγ)感染肺癌细胞株A549、肝癌细胞株SMMC-7721、胰腺癌细胞株PANC-1和正常成纤维细胞株BJ,通过病毒增殖实验、细胞病理效应和细胞杀伤实验观察CNHK300-Mγ、CNHK300和ONYX-015在上述肿瘤细胞和正常细胞中的增殖能力和对这些细胞的杀伤作用,通过双抗体夹心ELISA检测CNHK300-Mγ和AdEasy -Mγ在上述肿瘤细胞和正常细胞中不同时相的mIFN-γ表达量。结果: CNHK300-Mγ具有类似于CNHK300的肿瘤细胞选择增殖性,能在恶性肿瘤细胞中大量增殖并杀灭肿瘤细胞,均强于ONYX-015(P<0.01),而在正常细胞中增殖和杀伤作用均较弱,弱于ONYX-015(P<0.05)。CNHK300-Mγ感染恶性肿瘤细胞后有大量的mIFN-γ表达,并随着感染时间延长表达量也相应上升,而AdEasy-Mγ感染后只有少量mIFN-γ的表达,而且感染的时间延长表达量变化也不大(P<0.01)。结论: CNHK300-Mγ能选择性地在肿瘤细胞中增殖,并杀灭肿瘤细胞,同时大量表达具有抗肿瘤作用的蛋白,发挥多重抗瘤作用,有良好的临床应用前景。