Gamma-interferon (IFN-gamma) augments apoptotic response to mistletoe lectin-II via upregulation of Fas/Fas L expression and caspase activation in human myeloid U937 cells

Mistletoe lectin-II, a major composition of Korean mistletoe (Viscum album coloratum), is known as a potent apoptosis inducer. The previous research has demonstrated that Korean mistletoe lectin-II induces apoptosis via c-Jun N terminal kinase (JNK) activation in human myeloid U937 cells. The purpose of this research is to prove the synergistic action of mistletoe lectin-II and interferon-γ (IFN-γ) in the apoptotic cytotoxicity of U937. When U937 cells were treated with mistletoe lectin-II after being differentiated by IFN-γ, the proteolytic activity of caspase-3 and 9 was markedly elevated and that of caspase-8 was prolonged for 18 hr. The activation of caspase-3-like protease requires the earlier cleavage of poly(ADP-ribose) polymerase(PARP). Caspase-1 was, however, not activated during the resting phase and nor in IFN-γ-differentiated U937 cells. Western blot analysis revealed that, in IFN-γ-differentiated U937 cells, the expression of Fas (CD95/APO-1) & Fas ligand(FasL) increases the apoptotic sensitivity against Mistletoe lectin-II. Fas (CD95/APO-1) & FasL were not significantly induced solely by mistletoe lectin-II. Furthermore the activity of JNK1 in U937 cells was also markedly increased with IFN-γ-differentiation, compared to that of the control. These results suggest that the IFN-γ-differentiation of U937 cells increases the susceptibility to mistletoe lectin-II-induced apoptosis.     

慢性乙型肝炎患者肝组织FasL表达与血清可溶性FasL水平的关系

目的：探讨慢性乙型肝炎患者肝组织中FasL表达与血清可溶性FasL水平的关系。方法：用免疫组化方法检测60例慢性乙型肝炎患者肝穿组织FasL的表达,同时用酶联免疫吸附试验检测血清可溶性FasL。结果：重度慢性乙型肝炎患者血清中sFasL水平＞中度＞轻度,各组间差异有显著意义（P＜0．01）;慢性乙型肝炎患者肝组织FasL表达的程度和血清sFasL水平与肝组织病变的活动性一致。结论：（1）肝组织炎症程度加重,肝组织FasL抗原的表达增强,同时血清中sFasL水平升高;（2）Fas介导的肝细胞凋亡在慢性乙型肝炎的发病机制中起重要作用,抑制肝细胞Fas表达有助于减轻肝细胞损伤程度。     

The therapeutic effect of Interleukin-18 on hypertrophic scar through inducing Fas ligand expression

ObjectiveAmong downstream interleukin-18 (IL-18) targets, Fas ligand (FasL) in particular, has been strongly implicated in many conditions. Our study aims to explore the role of IL-18 in hypertrophic scar through enhancing FasL expression.MethodsIL-18 expression in hypertrophic scar tissues and normal tissues were explored by immunohistochemistry, qRT-PCR and Western blotting, and the expression of IL-18 in normal skin fibroblasts and hypertrophic scar fibroblasts by immunofluorescence. Hypertrophic scar fibroblasts treated with recombinant human IL-18 (rhIL-18) were assessed with MTT, Annexin V-FITC/PI, qRT-PCR, ELISA and western blotting. In the hypertrophic scar of rabbit ears, rhIL-18 was injected to determine histological changes with HE and Masson staining. Additionally, the scars were rated based on contour and overall severity using a visual analog scale scores (VAS).ResultsIL-18 was decreased in hypertrophic scar tissues and fibroblasts compared to normal skin tissues and fibroblasts, respectively. Decreased proliferation and increased apoptosis of hypertrophic scar fibroblasts were found after rhIL-18 treatment with enhanced expression of FasL, sFasL FADD, Caspase-8, Caspase-9 and Caspase-3 in a dose-dependent manner. The VAS and thickness of scars in rabbit ears was decreased as time went on after rhIL-18 treatment, with decreases in scar elevation index (SEI) and the increases in FasL expression.ConclusionIL-18 curbs proliferation and promotes apoptosis of hypertrophic scar fibroblasts by enhancing FasL expression. IL-18is a potential target for treatment of hypertrophic scar.     

表达FasL的肝癌细胞通过Fas/FasL诱导T淋巴细胞发生凋亡

目的研究发现肿瘤组织中FasL阳性表达区肿瘤浸润淋巴细胞的凋亡率比FasL阴性区高,推测肿瘤细胞可通过增加FasL表达来促使肿瘤浸润淋巴细胞凋亡.本实验在体外验证肝癌细胞是否可以诱导T淋巴细胞发生凋亡.方法选择FasL表达阳性的肝癌细胞(效应细胞)与对Fas介导凋亡敏感的活化T淋巴细胞共培养,取3种效靶比20:1,10:1,5:1.生长曲线法,流式细胞术,荧光显微镜观察分别检测T淋巴细胞的凋亡情况.结果流式细胞仪检测结果显示,肝癌细胞接种浓度为0(对照),0.5×105/ml,1×105/ml,2×105/ml时,T淋巴细胞凋亡率为1.80±0.21%,5.49±0.17%,11.18±0.14%,18.22±0.11%.荧光显微镜观察结果表明,肝癌细胞接种浓度为0(对照),0.5×105/m1,1×105/ml,2×105/ml时,T淋巴细胞凋亡率为1.58±0.12%,5.22±0.13%,9.74±0.21%,19.33±0.18%.3种效靶比条件下,肝癌均能诱导T淋巴细胞发生凋亡.随着肝癌接种浓度的升高及培养时间的延长,T淋巴细胞凋亡率逐渐增加,每个实验组与对照组比较P值均＜0.01.结论肝癌细胞可以通过Fas系统诱导淋巴细胞发生凋亡,这为肝癌的免疫逃逸和反攻击提供了证据.     

Fas／FasL系统在肿瘤细胞耐药中的作用

目的：探讨凋亡基因Ｆａｓ／ＦａｓＬ对肿瘤细胞耐药性的影响。方法：多发性骨髓瘤敏感株ＲＰＭＩ８２２６和耐药株和ＲＰＭＩ８２２６／Ｄｏｘ４０分别和Ｄｏｘｏｒｕｂｉｃｉｎ、ＣＨ－１１作用，在不同时间和浓度下观察二株细胞的Ｆａｓ／ＦａｓＬ的表达和死亡情况。结果：Ｄｏｘｏｒｕｂｉｃｉｎ能上调Ｆａｓ／ＦａｓＬ在敏感株肿瘤细胞表面的表达，从而激发ＰＣＤ，而耐药株则无此作用，结论：耐药细胞通过改变其Ｆａｓ／Ｆａｓ     

Fas/FasL在肺癌中的表达

目的探讨Fas／FasL在肺癌中的表达及意义。方法采用免疫组化方法检测60例肺癌组织、癌旁组织及20例正常肺组织的Fas／FasL的表达。结果Fas／FasL在肺癌组织中阳性表达率显著低于Fas／FasL在癌旁组织及正常肺组织中Fas／FasL表达率。Fas／FasL在非小细胞肺癌组织中阳性表达率显著低于Fas／FasL在小细胞肺癌中阳性表达率。Fas的阳性表达率与PTNM及淋巴结转移无明显相关，FasL的阳性表达率与PTNM及淋巴结转移明显相关。结论Fas／FasL在肺癌的发生和发展中起重要作用。     

溴氰菊酯对PC12细胞Fas、FasL、TNFR1蛋白及凋亡的影响

背景与目的 :探讨溴氰菊酯诱导神经细胞凋亡及其神经毒作用机制。 材料与方法 :用免疫细胞化学法定性检测给予不同剂量水平(10 -4mol/L ,10 -5mol/L ,10 -6mol/L)的溴氰菊酯24h后 ,Fas、FasL、TNFR1蛋白在PC12细胞中的表达 ;流式细胞仪定量检测给予溴氰菊酯24h和48h后 ,Fas、FasL、TNFR1蛋白在PC12细胞中的相对表达量阳性细胞率(rateofpositivecells ,RPC)和平均荧光强度(meanfluorescenceintensity,MFI)及PC12细胞的凋亡率。 结果 :①Fas、FasL、TNFR1蛋白在对照组和各剂量组均为阳性表达 ,但镜下未见各蛋白在各组之间的差异表达。流式细胞仪检测发现 :染毒24h后 ,Fas、FasL蛋白在各组的表达没有差异 ,而TNFR1蛋白在中剂量和高剂量组的表达与对照组比较有升高 ;染毒48h后 ,Fas、FasL、TNFR1蛋白在高剂量组表达(MFI分别为42.85±8.4、37.91±1.65、8.09±1.83)与各自对照组比较均有升高。②染毒24h后 ,各剂量组凋亡率没有升高 ;染毒48h后 ,高剂量组凋亡率与对照组凋亡率比较有升高。③染毒48h组细胞凋亡率与溴氰菊酯浓度、Fas、Fasl蛋白含量有直线相关关系。 结论 :溴氰菊酯可能通过死亡受体Fas诱导PC12细胞凋亡。     

Immunoregulative Mechanism of the Leydig Cell in the Infection by Expression of IL-1,IL-6,TGF-β, Fas and FasL mRNA

Objective To investigate the immune regulative mechanism of Leydig cells in the localinfection of rat's testis.Methods Ureaplasma Urealyticum(UU) was injected into rat's bladder, which mimicked an ascending infectious way, and at the same time culture medium was injected into rat's bladder as the control. The rats were sacrificed at week 1, 2 and 3 after injection respectively. Then pathological changes in testis were analyzed by histological examination. At the same time Leydig cells were separated from rat's testis, The comparasion of levels of IL-1,IL-6, TGF-β, Fas and FasL mRNA expression among the three groups was made by RT-PCR.Results As compared with control group, the levels of IL-1, IL-6, TGF-β mRNA expression for UU supernatant and living UU groups increased; and levels of Fas and FasL mRNA expression decreased and increased respectively after UU infection.Conclusion During anti-infective immunity, rat's Leydig cells may regulate immune function of the testis by changing the levels of IL-1, IL-6, TGF-β, Fas and FasL mRNA expression and may contribute to maintain immune privilege of the testis.     

Fas 、FasL 在胃癌发生发展中的表达及其意义

 目的 研究Fas、FasL在胃癌发生发展中的表达，并探讨其临床病理意义。方法 应用免疫组化SABC法检测60例胃癌组织、癌旁交界组织、距肿瘤边缘5cm组织及20例良性胃疾病组织和20例正常胃黏膜中Fas、FasL的表达。结果 胃癌组织、癌旁交界组织、距肿瘤边缘5cm组织和良性胃疾病、正常胃黏膜组织的Fas阳性表达率分别为46．6％、51．6％、83．3％、85％、95％；FasL的阳性率则分别为86．6％、81．6％、26．6％、20％、10％。在胃癌不同分化程度之间，Fas和FasL表达有显著性差异(P<0．05)。而胃癌不同TNM分期，有无淋巴结转移之间则无显著性差异(P>0．05)。结论 Fas、FasL的表达失衡与胃癌的发生发展有着密切关系，并与胃癌的分化和免疫逃逸有关。