Fas/Fas配体在造影剂诱导肾小管细胞凋亡中的表达

随着介入治疗及医学影像学的发展，造影剂在临床上的应用越来越广泛，因造影剂所致的肾脏损害逐渐增多，但发病机制目前尚不十分清楚。肾小管细胞是造影剂肾损害的最常见的靶细胞之一，造影剂可直接作用于肾小管细胞导致其受损，如造影剂可诱导肾小管细胞凋亡。Fas／Fas配体(FasL)表达上调可参与肾小管细胞凋亡的调控。本研究旨在观察造影剂诱导肾小管细胞凋亡时Fas／FasL的表达。     

Fas/FasL系统与心肌缺血再灌注细胞凋亡

心肌缺血再灌注损伤与众多凋亡基因密切相关.Fas/FasL系统在心肌缺血再灌注损伤中起关键作用,是引起细胞凋亡的主要途径之一,是直接启动细胞凋亡信号传导的系统之一.Fas/FasL系统与心肌缺血再灌注细胞凋亡及其信号传导机制是目前国内外研究的热点,现对该问题做一综述.     

凋亡信号传导在急性胰腺炎发病中的作用研究

目前研究发现，急性胰腺炎的发生发展与细胞凋亡传导途径相关，其中与Caspase家族、Fas/FasL系统和Bcl－2家族的关系尤为密切，阐明凋亡信号传导途径有助于了解急性胰腺炎的发病机制。     

凋亡信号传导在急性胰腺炎发病中的作用研究

目前研究发现,急性胰腺炎的发生发展与细胞凋亡传导途径相关,其中与(Caspase家族、Fas/FasL系统和Bcl-2家族的关系尤为密切,阐明凋亡信号传导途径有助于了解急性胰腺炎的发病机制。     

苦参素对慢性乙型肝炎患者血清Fas、FasL、肿瘤坏死因子-α、白介素-6的影响

Fas与FasL结合可引起表达Fas靶细胞发生凋亡，细胞毒性T细胞(CTLs)介导的细胞免疫在乙型肝炎的发病中起着重要作用，其主要机制是通过FasL介导Fas阳性的肝细胞凋亡，因此Fas／FasL介导的细胞凋亡与乙型肝炎的发生发展有着密切关系。肿瘤坏死因子-α(TNF-α)是由巨噬细胞及单核细胞分泌的一种炎症细胞因子，具有多种生物学效应，是引起肝损伤的重要因素，也可通过TNF受体(TNFR1)介导肝细胞凋亡；白介素-6(IL-6)主要是由巨噬细胞、T细胞、B细胞等产生的一种糖蛋白，具有调节免疫应答，参与机体炎症反应等作用。我们旨在观察苦参素治疗慢性乙型肝炎(CHB)后血清中Fas、FasL、TNF-α、IL-6的水平变化特点，进一步探讨苦参素治疗CHB的作用机制。     

Fas、FasL与1型糖尿病

1型糖尿病是T细胞介导的自身免疫性疾病 ,β细胞凋亡在其发病中起了一定作用 ,Fas/FasL系统参与 β细胞凋亡。Fas是死亡因子 ,FasL是其受体 ,表达Fas的细胞和表达FasL的细胞或抗Fas抗体结合均可导致表达Fas的细胞凋亡。正常胰腺细胞不表达Fas,胰岛炎时 ,许多细胞因子和炎症介质可诱导胰岛β细胞表达Fas,从而被表达FasL的细胞 (T细胞或胰岛α及 β细胞 )诱导凋亡 ,导致糖尿病的发生。对Fas/FasL研究可能在 1型糖尿病免疫预防上具有潜在的应用前景。     

生大黄对急性胰腺炎患者外周血浆 Fas 和 Fas 配体表达的影响

急性胰腺炎（AP）是常见的急腹症之一,约80％的 AP 患者经内科保守治疗可好转,但有约20％的病例发展为重症胰腺炎（SAP）,其病死率可达15％～40％［1］。细胞凋亡对胰腺具有保护作用,与 AP 的严重程度呈负相关［2］。细胞凋亡是由基因控制的,参与凋亡调控的基因由很多种,Fas／Fas 配体（FasL）系统被认为是一条最主要的介导细胞凋亡的信号传导通路。中医采用大黄治疗 AP 历史悠久,且取得很好的临床疗效。本研究旨在观察生大黄对急性胰腺炎患者外周血浆 Fas 和 FasL 表达的影响。     

大鼠心肌缺血/再灌注损伤心肌细胞凋亡与Fas、FasL基因表达的变化

目的：探讨大鼠实验性心肌缺血再灌注时心肌细胞凋亡与Fas及Fas蛋白配体（Fas Ligand,FasL）基因表达的变化及与心肌组织损伤的关系。方法：以穿线结扎或松扎左冠状动脉制备大鼠心肌缺血再灌注模型。64只大鼠随机分成假手术组（假手术24h）、缺血再灌注I组（缺血30min、再灌注24h）、缺血再灌注Ⅱ组（缺备30min、再灌注72h）及缺血再灌注Ⅲ组（缺血3h、再灌注24h）。以缺口末端标记法检测心肌细胞凋亡的变化,S－P免疫组化法分别检测Fas与FasL蛋白水平变化,采用逆转录聚合酶链反应法检测Fas基因mRNA的表达改变,并分析心肌组织病理学损伤程度。结果：心肌缺血再灌注后心肌细胞凋亡指数Fas蛋白阳性染色指数与炎性细胞FasL蛋白阳性染色指数均增加,且均随缺血或再灌注时间延长而进一步增高; Fas基因的mRNA表达也上调,但以再灌注24h时达高峰;心肌缺血再灌注后心肌组织呈大小不一的灶性坏死,坏死周围有爆炸性一细胞浸润。结论：心肌缺血再灌注时心肌细胞凋亡、Fas基因的蛋白与mRNA表达水平及炎性细胞的FasL蛋白表达量均增加,心肌细胞凋亡与Fas/FasL系统参与了心肌缺血再灌注损伤过程。     

组织金属蛋白酶抑制因子3重组蛋白诱导小鼠成骨细胞MC3T3-E1凋亡

目的 研究组织金属蛋白酶抑制因子3（TIMP-3）重组蛋白对MC3T3-E1成骨细胞凋亡的影响。方法 细胞存活率和凋亡分别用MTT及ELISA检测。Fas，FasL，Bcl-2，Bax，caspase-3，caspase-8，细胞色素c的表达以及JNK，p38，细胞外信号调节激酶（ERK）1／2的磷酸化水平用Western印迹检测。结果 MTT及ELISA检测提示TIMP-3降低MC3T3-E1细胞存活率，诱导MC3T3-E1细胞凋亡。TIMP-1增加Fas、FasL蛋白表达，对Bax、Bcl-2蛋白表达无影响，但可诱导细胞色素c的释放及caspase-8、caspase-3的活化。TIMP-3促进p38和ERK磷酸化，而PD098059（ERK阻断剂）和SB203580（p38阻断剂）消除p38和ERK的促凋亡作用。结论 TIMP-3诱导MC3T3-E1细胞凋亡的信号途径为凋亡受体Fas介导，并有p38、ERK信号转导途径参与。     

福辛普利对实验性心力衰竭大鼠心肌细胞凋亡和Fas、Fas配体基因表达的影响

目的:探讨实验性心力衰竭大鼠心肌细胞凋亡和心肌组织Fas、Fas配体(FasL)蛋白及其信使核糖核酸(mRNA)表达的变化及血管紧张素转换酶抑制剂(ACEI)干预的影响及意义.方法:将30只健康Wistar大鼠,随机分为假手术组(n=10)、慢性心力衰竭组(n=10)和福辛普利组(n=10).通过缩窄Wistar大鼠腹主动脉建立慢性心力衰竭模型,以福辛普利进行干预,对照观察血流动力学、心肌细胞凋亡、心肌组织Fas、FasL蛋白及其mRNA表达的变化.结果:与假手术组相比,慢性心力衰竭组左心室舒张末压、心率显著升高(P＜0.01);收缩压、舒张压、平均压、左心室收缩压、左心室内压最大收缩率、左心室内压最大舒张率显著降低(P＜0.01).福辛普利组舒张压、左心室收缩压、左心室舒张末压、心率显著低于慢性心力衰竭组(P＜0.01),左心室内压最大收缩率、左心室内压最大舒张率显著高于慢性心力衰竭组(P＜0.01).慢性心力衰竭组心肌细胞凋亡指数、心肌组织Fas、FasL蛋白及其mRNA表达水平显著高于假手术组(P＜0.05),福辛普利组心肌细胞凋亡指数、心肌组织Fas、FasL蛋白及其mRNA表达水平显著低于慢性心力衰竭组(P＜0.05).结论:慢性心力衰竭的发生、发展过程中有心肌细胞凋亡的变化及Fas/FasL系统的参与;心力衰竭大鼠心肌细胞凋亡指数、心肌组织Fas、FasL蛋白及其mRNA表达水平增高,福辛普利长期干预慢性心力衰竭,能够降低细胞凋亡及Fas、FasL基因的表达,可能与其减少Fas/FasL系统介导的细胞凋亡的发生、改善心肌功能有关.     

Fas/FasL系统表达与结直肠癌的研究进展

细胞凋亡是指在一定生理和病理情况下,机体为维护内环境的稳定而发生的主动性细胞死亡过程,即程序性死亡.由死亡受体与其配体相互作用是引起细胞凋亡的主要途径之一,其中Fas/FasL系统是被认为最主要的介导细胞凋亡的信号转导途径.大肠癌是严重威胁人类健康的常见恶性肿瘤之一,大肠癌的发生、发展与细胞凋亡的调节失衡有关.本文就Fas/ FasL系统表达与结直肠癌发生发展的关系及相关方面研究作一综述.     

脱氢表雄酮在体外对胸腺细胞的调节机制研究

目的 通过观察脱氢表雄酮(DHEA)对胸腺细胞凋亡及CD95/CD95配体(Fag/FagL)表达的影响,探讨在免疫系统中的作用.方法 四甲基偶氮唑盐比色分析法(MTT法)观察细胞的活力,用梯度状凝胶电泳观察细胞凋亡,反转录-聚合酶链反应(RT-PcR)法检测Fag与Fag-L的表达.结果 DHEA在体外降低胸腺细胞活力,促进细胞的凋亡,上调Fas/Fas-L mRNA的表达.结论 DHEA能通过Fas/FasL途径诱导胸腺细胞凋亡,提示DHEA可能在一些凋亡失调相关的自身免疫性疾病的发生发展中起作用.     

原发性干燥综合征患者唇腺组织中CAD的表达与细胞凋亡的关系

目的 研究原发性干燥综合症（primary Sjgren＇s syndromepss）唇腺组织细胞中Fas介导的细胞凋亡信号转导相关蛋白的表达，探讨导致干燥综合征的细胞信号转导的可能途径。方法 采用Westernblot法检测唇腺组织中Fas、FasL蛋白的表达；RT-PCR半定量检测CAD mRNA表达。结果 与对照组比较pSS患者唇腺组织细胞中Fas介导的细胞凋亡信号转导相关蛋白Fas、FasL的表达及CADmRNA表达都有不同程度增高（P〈0．05）。结论 导致干燥综合征患者唇腺组织凋亡的信号转导途径可能是由Fas介导的。     

Fas/FasL与支气管哮喘

Fas受体和Fas配体(FasL)在免疫细胞上的表达相对较高,其介导的细胞凋亡、增殖与免疫细胞的凋亡、增殖及功能发挥密切相关,在哮喘免疫耐受及调控异常、Th1/Th2失衡、气道炎症、黏液产生、气道高反应及气道重塑中发挥了重要作用,有望成为哮喘治疗的突破口。但是,在Fas/FasL信号转导过程中,各种因素构成了一个复杂的调控网络,深入研究Fas/FasL信号转导途径及其相关的调控机制才能为哮喘治疗开创新途径。     

Fas/FasL与支气管哮喘

Fas受体和Fas配体(FasL)在免疫细胞上的表达相对较高,其介导的细胞凋亡、增殖与免疫细胞的凋亡、增殖及功能发挥密切相关,在哮喘免疫耐受及调控异常、Th1/Th2失衡、气道炎症、黏液产生、气道高反应及气道重塑中发挥了重要作用,有望成为哮喘治疗的突破口.但是,在Fas/FasL信号转导过程中,各种因素构成了一个复杂的...     

凋亡信号调节激酶1与心脏肥大研究进展

心脏肥大是心肌细胞对高血压、瓣膜病、急性心肌梗死及先天性心脏病等常见临床疾病的一种基本应答,是影响心血管疾病病死率和发病率的独立危险因素,其发病机制中信号转导通路的研究是当前研究热点。凋亡信号调节激酶1是有丝分裂原激活蛋白激酶的上游激酶,参与细胞的生长、分化、凋亡,近年来研究发现它与心脏肥大的发生也存在密切关系。     

Differential effects of membrane and soluble Fas ligand on cardiomyocytes: role in ischemia/reperfusion injury

Cardiomyocyte apoptosis by Fas ligand (FasL)/Fas signaling is associated with various pathophysiological conditions, such as ischemia/reperfusion injury and congestive heart failure. In this study, we tested the hypothesis that shedding of membrane FasL is a mechanism for downregulating FasL/Fas signaling and both membrane and soluble FasL are involved in cardiomyocyte hypoxia/reoxygenation (H/R) injury. We also examined the relative importance of mitochondrial damage and direct cleavage of the executioner caspases by activated initiator caspase 8 in the propagation of FasL/Fas signaling activated by either recombinant membrane FasL or H/R. We demonstrated that in neonatal rat cardiomyocytes maintained under normal culture conditions, recombinant human soluble FasL increased caspase 3 activation by twofold but did not reduce cell viability. In contrast, infection with a recombinant adenoviral vector expressing the non-cleavable human FasL (Ad2/nchFasL) resulted in cardiomyocyte death that was attenuated by soluble FasL. H/R increased the mRNA levels of both FasL and Fas and activated caspases 8, 9 and 3, indicating the activation of FasL/Fas signaling. Z-IETD.fmk and Z-LEHD.fmk, selective inhibitors for caspases 8 and 9, respectively, abolished caspase 3 activation induced by Ad2/nchFasL or H/R. Z-IETD.fmk also significantly reduced Ad2/nchFasL- or H/R-induced cardiomyocyte death. H/R potentiated membrane FasL-induced cell death. These results suggest that shedding of membrane FasL downregulates FasL/Fas signaling in cardiomyocytes and both membrane and soluble FasL contribute to H/R injury. Activation of FasL/Fas signaling by either recombinant membrane FasL under normal culture conditions or H/R causes cardiomyocyte death mainly through the mitochondrial damage/caspase 9 activation pathway.     

Dual response to Fas ligation in human endothelial cells: apoptosis and induction of chemokines,interleukin-8 and monocyte chemoattractant protein-1

BACKGROUND: To maintain the integrity of tissues, endothelial cells play critical roles. Fas ligand (FasL) is well known to deliver a death signal through its receptor, Fas. The Fas/FasL system may concomitantly induce expressions of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) besides triggering apoptosis in endothelial cells. We also investigated whether an inhibitor of caspase-8 (Z-IETD-FMK) does modulate IL-8 and MCP-1 secretion. METHODS AND RESULTS: After treatment with interferon-gamma (IFN-gamma), human recombinant FasL (hr FasL) or Fas agonistic antibody (CH-11) was added to cultured human endothelial cells. IFN-gamma up-regulated Fas mRNA levels. Fas ligation promoted apoptosis assessed by fluorescent-activated cell sorter (FACS) analysis in a dose-dependent manner and induced prominent DNA fragmentation. Simultaneously, IL-8 and MCP-1 were secreted from the endothelial cells in response to hr FasL or CH-11 in a dose-dependent manner (P < 0.01). Fas-neutralizing agent (Fas-Fc) suppressed the Fas-mediated secretions of IL-8 and MCP-1 (P < 0.01) both as well as the Fas-mediated apoptosis. On the other hand, whereas Z-IETD-FMK suppressed apoptosis, the inhibitor enhanced the Fas-mediated secretions of both IL-8 and MCP-1 beyond the value of the Fas stimulation alone (P < 0.01), suggesting an enhanced signalling for the chemokine expression. CONCLUSION: In human endothelial cells, the Fas/FasL system induces both IL-8 and MCP-1 secretions probably via a caspase-8 independent pathway. The Fas/FasL system may amplify the inflammatory cascade in the vascular injury and atherogenesis by recruiting leukocytes at the region of apoptotic endothelial damage.     

Suppression of FasL expression in tumor cells and preventing TNF-induced apoptosis was better for immune cells survival

OBJECTIVE: To elucidate if Fas/FasL signal pathway participates in the immune escape of tumor cells, and if contemporarily preventing Fas/FasL and TNF-induced apoptosis is better for immune cells survival than just blocking Fas/FasL-induced apoptotic signal. METHODS: Suppression of FasL expression in mouse H22 hepatocellular cancer cells by siRNA technique. Wild-type Ad5 14.7K gene was amplified by PCR and transduced into Jurkat T cells. Detecting apoptosis of target Jurkat cells by Flow Cytometry. Detection of TNF-alpha in the culture supernatant of H22 cells by ELISA. FasL and 14.7K gene expression in stably transfected or transduced clones were determined by western blotting. RESULTS: FasL expression in H22 cells was down-regulated following stable transfection with a plasmid encoding antisense FasL cDNA. Down-regulation of FasL expression in H22 cells had no effect on tumor growth in vitro. There was an apparent decrease in the number of apoptotic Jurkat T cells following coculture with transfected H22 cells, relative to coculture with FasL-expressing untransfected cells. Compared with untransduced Jurkat cells, apoptotic rates in 14.7K transduced Jurkat cells were significantly reduced in three different E/T ratios (P < 0.01), respectively. CONCLUSIONS: Fas/FasL signal pathway participated in the immune escape of tumor cells by inducing immune cells apoptosis. Reducing the expression of FasL in tumor cells can decrease the apoptotic rate of immune cells. Further blocking of apoptotic signal pathway of immune cells by preventing TNF-induced apoptosis can increase the survival of immune cells.