FTY720介导的淋巴细胞归巢作用对外周淋巴细胞的影响

FTY720是由ISP-I衍生而来的一类新型免疫抑制剂。近年来的研究显示，FTY720在器官移植排斥以及自身免疫性疾病的一系列模型中显示出良好的治疗效果。研究表明，FTY720主要通过减少外周淋巴细胞数目发挥免疫抑制作用，但其具体作用机制仍存在争议。一部分观点认为FTY720是通过诱导外周淋巴细胞发生凋亡而引起白细胞数急剧下降；另一部分观点则认为FTY720是通过阻断淋巴细胞外流，即将淋巴细胞阻断在次级淋巴组织中，从而阻止活化的淋巴细胞迁移至移植器官或炎症组织部位，达到免疫抑制作用。本研究通过流式细胞技术以及荧光染料标记细胞跟踪技术证实：FTY720主要是通过促进外周循环中的淋巴细胞归巢而发挥其免疫抑制作用。     

S1P受体激动剂FTY720干扰孕鼠体内DC分布从而诱导妊娠免疫耐受

目的探讨S1P受体激动剂FTY720在降低自然流产模型孕鼠胚胎丢失率进程中的作用及其可能的机制。方法以自然流产模型孕鼠为研究对象,观察腹腔注射FTY720对自然流产模型孕鼠胚胎丢失率的影响,RT-PCR检测DC表面S1PR的表达,流式细胞术及免疫组化检测孕鼠外周血及局部组织中DC数量、成熟度及其表面相应趋化因子CCL19及其受体CCR7的表达情况,趋化实验验证FTY720对DC细胞趋化能力的影响。结果 1)FTY720对正常妊娠模型孕鼠的胚胎丢失率无明显影响(P<0.05),过继转移FTY720能明显降低自然流产模型孕鼠的胚胎丢失率(P<0.05);2)DC表面存在S1P受体的广泛表达,S1P受体激动剂FTY720减少了DC表面趋化因子及其受体的表达(P<0.05),致使趋化至母胎界面DC的数量显著减少(P<0.05);3)FTY720对DC细胞的分化及凋亡率均无明显影响(P>0.05)。结论 FTY720可能通过下调DC表面趋化因子受体CCR7的表达而使趋化至母胎界面的DC数量减少,最终诱导母胎免疫耐受。     

FTY720对肾缺血再灌注大鼠脑损伤的保护作用和机制

目的:通过肾缺血再灌注损伤(RIRI)大鼠模型来探讨FTY720能否对大鼠术后的脑损伤产生保护作用及其机制.方法:将30只SD雄性大鼠随机分为假手术组(Sham组),模型组(RIRI组)和FTY720干预组(FTY720组),每组10只.RIRI组和FTY720组建立RIRI模型,Sham组仅暴露肾蒂,不做缺血处理;再灌注前15min,FTY720组腹腔注射液FTY720(1 mg·kg-1),Sham组和RIRI组腹腔注射等体积生理盐水.术后24h每组随机选取5只大鼠处死,取肾组织和脑组织,HE染色观察肾脏组织和海马组织CA1区的病理改变,TUNEL法测定海马组织CA1区神经细胞的凋亡情况,Western Blot检测海马组织CA1区天冬氨酸特异性半胱氨酸蛋白3(Caspase-3)的表达水平;各组剩余5只大鼠进行Morris水迷宫实验,检测其学习能力和空间记忆能力.结果:与Sham组相比,RIRI组大鼠肾脏组织和海马组织CA1区出现明显病理损伤,海马组织CA1区凋亡细胞数显著增多,Caspase-3表达水平均显著升高,Morris水迷宫实验中大鼠逃避潜伏期显著延长,穿越穿台次数显著减少,差异均有统计学意义(P<0.05);与RIRI组比较,FTY720组大鼠海马组织CA1区病理性评分显著降低,凋亡细胞数显著减少,Caspase-3表达水平均显著降低,在Morris水迷宫实验中,FTY720组大鼠逃避潜伏期显著缩短,平台穿越次数显著增加,差异均有统计学意义(P<0.05).结论:FTY720能改善RIRI引起的大鼠脑损伤和认知功能障碍,其机制可能与FTY720抑制Caspase-3的表达水平,减少海马组织CA1区神经元细胞凋亡有关.     

FTY720与吉西他滨对非小细胞肺癌A549和H520细胞增殖和凋亡的影响

目的探讨FTY720、吉西他滨以及两种联合应用对非小细胞肺癌(NSCLC)肿瘤细胞株A549和H520增殖和凋亡的影响。方法培养NSCLC肿瘤细胞株A549和H520,采集对数生长周期的A549、H520,接种于培养板中,分别向培养孔加入不同浓度的FTY720以及两种药物的联合,培养48h后计算细胞存活率,应用双染流式细胞检测技术检测细胞凋亡情况。结果 FTY720不同浓度下培养24h、48h、72h,A549细胞、H520细胞的存活率均呈浓度依赖性,药物浓度越高,细胞存活率越低。联合用药的细胞存活率明显低于单独用药(P0.05),细胞凋亡率明显高于单独用药(P0.05)。结论 FTY720与吉西他滨联合应用有效提高吉西他滨对NSCLC肿瘤细胞株A549、H520的敏感性,抑制肿瘤细胞增殖,促进肿瘤细胞凋亡。     

芬戈莫德预先给药对急性呼吸窘迫综合征大鼠肺损伤的保护作用

目的:研究1-磷酸鞘氨醇(S1P)受体激动剂芬戈莫德(FTY720)预先给药对急性呼吸窘迫综合征(ARDS)大鼠肺损伤的保护作用.方法:30只SD大鼠随机平分为正常组、模型组和FTY720预处理组,FTY720预处理组给予FTY7203mg/kg灌胃7天进行预处理,之后模型组和FTY720预处理组大鼠构建ARDS模型....     

FTY720诱导1型1-磷酸鞘氨醇受体内化与其保守基序的关系研究

目的:研究FTY720诱导1型1-磷酸鞘氨醇受体(S1P1)内化与后者保守基序之间的关系.方法:以HA-S1P1(WT)-Myc-EGFP-N1融合表达载体为模板,应用重叠PCR的方法,将S1P1保守基序ERY突变为ENY,构建HA-S1P1(R142N)-Myc-EGFP-N1融合表达载体.测序鉴定后,经Polyfect转染入HEK293细胞.G418筛选出稳定细胞株.100 nmol/L FTY720处理3、6、12小时后,荧光显微镜下观察S1P1在HEK293细胞上的表达情况.结果:HA-S1P1(R142N)-Myc-EGFP-N1载体被成功构建,S1P1(WT)和S1P1(R142N)蛋白表达在HEK293稳定细胞株的表面,FTY720能诱导S1P1(WT)内化,但不能诱导S1P1(R142N)内化.结论:FTY720诱导S1P1内化与ERY保守基序有关.     

S1P1受体ERY保守基序突变对FTY720诱导其内化的影响

1型1-磷酸鞘氨醇受体(S1P1)是淋巴细胞表面的重要受体。为研究S1P1中ERY保守基序与FTY720诱导其内化的关系,以HA-S1P1-Myc-EGFP-N1为模板,应用重叠PCR的方法,将S1P1第142位的Arg(R)突变为Asn(N),连同N端HA标签一起,克隆入pcDNA3.1(+)真核表达载体。同时PCR扩增野生型S1P1,克隆入pcDNA3.1(+)中。限制性酶切消化、PCR和测序鉴定后,经Polyfect转染入HEK293细胞。G418筛选出稳定细胞株。100 nmol/L FTY720处理12 h后,抗HA-PE抗体染色,用流式细胞仪检测S1P1在HEK293细胞上的表达情况。结果显示HA-S1P1(WT)-pcDNA3.1(+)和HA-S1P1(R142N)-pcDNA3.1(+)载体被成功构建,HA-S1P1(WT)和HA-S1P1(R142N)蛋白表达在HEK293稳定细胞株的表面。FTY720能诱导HA-S1P1(WT)内化,但不能诱导HA-S1P1(R142N)内化。提示FTY720诱导S1P1内化与ERY保守基序有关。     

FTY720, sphingosine 1-phosphate receptor modulator, ameliorates experimental autoimmune encephalomyelitis by inhibition of T cell infiltration

FTY720, a sphingosine 1-phosphate receptor modulator, induces a marked decrease in the number of peripheral blood lymphocytes and exerts immunomodulating activity in various experimental allograft and autoimmune disease models. In this study, we evaluated the effect of FTY720 and its active metabolite, （S）-enantiomer of FTY720-phosphate [（S）-FTY720-P] on experimental autoimmune encephalomyelitis （EAE） in rats and mice. Prophylactic administration of FTY720 at 0.1 to 1 mg/kg almost completely prevented the development of EAE, and therapeutic treatment with FTY720 significantly inhibited the progression of EAE and EAE-associated histological change in the spinal cords of LEW rats induced by immunization with myelin basic protein. Consistent with rat EAE, the development of proteolipid protein-induced EAE in SJL/J mice was almost completely prevented and infiltration of CD4^＋ T cells into spinal cord was decreased by prophylactic treatment with FTY720 and （S）-FTY720-P. When FTY720 or （S）-FTY720-P was given after establishment of EAE in SJL/J mice, the relapse of EAE was markedly inhibited as compared with interferon-β, and the area of demyelination and the infiltration of CD4^＋ T cells were decreased in spinal cords of EAE mice. Similar therapeutic effect by FTY720 was obtained in myelin oligodendrocyte glycoprotein-induced EAE in C57BL/6 mice. These results indicate that FTY720 exhibits not only a prophylactic but also a therapeutic effect on EAE in rats and mice, and that the effect of FTY720 on EAE appears to be due to a reduction of the infiltration of myelin antigen-specific CD4^＋ T cells into the inflammation site. Cellular ＆ Molecular Immunology. 2005;2（6）：439-448.     

FTY720抑制TLR4信号转导的炎症反应

FTY720是一种1-磷酸神经鞘氨醇(sphingosine 1-phosphate,S1P)受体拮抗剂。为阐明FTY720抑制炎症反应的机理,本研究采用流式细胞术检测FTY720对细菌脂多糖(LPS)刺激后小鼠脾脏细胞TLR4表达水平的影响。研究发现,注射适当剂量的FTY720可削弱LPS所引起的TLR4表达水平增强(FTY720处理组与对照组相比,TLR4+细胞构成比分别为6.7%±1.5%和38.6%±3.1%,P<0.01),并可消除LPS刺激所引起的外周血TNF-α、IFN-γ和IL-12等Th1型细胞因子表达水平增高(FTY720组血清TNF-α、IFN-γ和IL-12浓度分别为(72±22)ng/ml、(46±21)ng/ml和(19±4)ng/ml,LPS组分别为(300±75)ng/ml、(175±35)ng/ml和(50±8)ng/ml,均为P<0.01)。相反,FTY720组血清Th2型细胞因子IL-4水平与对照组相比分别为(7±3)ng/ml和(7±2)ng/ml,无显著性差异。在体外细胞培养实验中可观察到一致的结果。这些发现提示,FTY720可能通过抑制LPS/TLR4信息转导通路,下调TNF-α、IFN-γ和IL-12等Th1型细胞因子表达而抑制炎症反应。     

芬戈莫德(FTY720)通过激活Nrf2/HO-1通路促进大鼠脑缺血再灌注损伤后神经功能恢复

目的 研究芬戈莫德(FTY720/fingolimod)对脑缺血再灌注损伤的治疗作用并探索其保护机制.方法 60只SD大鼠随机分为假手术组、脑缺血再灌注损伤(MCAO/R)模型组及FTY720组.MCAO/R组和FTY720组用Longa缝合法建立MCAO/R模型.采用改良神经功能损伤评分法评估大鼠神经功能;HE染色观...     

A novel immunosuppressant, FTY720, increases the efficiency of a superantigen-induced peripheral T-cell deletion whilst inhibiting negative selection in the thymus.

A novel immunosuppressant, FTY720, was generated by chemical modification of ISP-I, an immunosuppressive compound purified from culture filtrates of Isaria sinclairii. FTY720 directly induces apoptotic cell death in lymphocytes, which is believed to be the mechanism by which this drug exerts its immunosuppressive effect. We examined the effect of FTY720 treatment on antigen-induced apoptotic cell death in peripheral T cells and thymocytes. A superantigen, staphylococcus enterotoxin B (SEB), induces T-cell antigen receptor (TCR) Vbeta-specific apoptotic cell death in mature T cells in vivo. In this well-documented experimental system, FTY720 administration significantly enhanced the efficiency of superantigen-induced T-cell deletion. We also determined that apoptotic cell death with DNA fragmentation induced in T-hybridoma cells after stimulation in vitro with anti-TCR antibodies was enhanced in the presence of non-cytolytic doses of FTY720. In sharp contrast, negative selection of T cells in the thymus, another example of antigen-induced apoptosis, was found to be inhibited by FTY720 treatment. A rescue effect was observed on clonal deletion in the H-Y-specific TCRalpha beta transgenic male thymus. In a chicken egg albumin (OVA)-specific TCRalphabeta transgenic system, OVA-induced apoptotic cell death of CD4+CD8+ thymocytes was also inhibited by FTY720 injection. Thus, FTY720 increased the susceptibility of mature T cells to TCR-mediated apoptosis but decreased that of immature thymocytes. The results in this report suggest that the potent immunosuppressive effect of FTY720 is, in part, a result of the augmentation of effects on antigen-induced apoptosis in mature T cells, and that two distinct apoptotic cell death pathways are operating in mature and immature T cells.     

FTY720 enhances the activation-induced apoptosis of donor T cells and modulates graft-versus-host disease

FTY720 is a novel immunosuppressant that improves the outcomes after solid organ and bone marrow transplantation (BMT) due to the sequestration of T cells into LN. We tested the hypothesis that the sequestration of donor T cells in LN by FTY720 would enhance their interaction with host APC, thus causing a greater degree of activation-induced apoptosis of alloreactive T cells, and thereby resulting in a reduction of graft-vs.-host disease (GVHD). The short-term administration of FTY720 improved the recipient survival after allogeneic BMT. FTY720 treatment facilitated a rapid contraction of the donor T cell pool in association with an increased degree of apoptosis of donor T cells. The donor T cell reactivity to host alloantigens was diminished in host's LN and adoptive transfer of donor T cells isolated from LN of FTY720-treated recipients of allogeneic BMT induced less severe GVHD in secondary recipients than the transfer from controls. Caspase-dependent apoptosis was involved in this mechanism because FTY720-induced protection was abrogated when a pan-caspase inhibitor was administered. These findings thus demonstrate the presence of a novel mechanism by which FTY720 modulates the allogeneic T cell responses: namely, by the induction of activation-induced apoptosis of alloreactive T cells in LN.     

Anti-inflammatory effects of FTY720 do not prevent neuronal cell loss in a rat model of optic neuritis

In multiple sclerosis, long-term disability is caused by axonal and neuronal damage. Established therapies target primarily the inflammatory component of the disease, but fail to prevent neurodegeneration. Fingolimod (codenamed FTY720) is an oral sphingosine 1-phosphate (S1P) receptor modulator with promising results in phase II trials in multiple sclerosis patients and is under further development as a novel treatment for multiple sclerosis. To evaluate whether FTY720 has neuroprotective properties, we tested this drug in a rat model of myelin oligodendrocyte glycoprotein-induced optic neuritis. FTY720 exerted significant anti-inflammatory effects during optic neuritis and reduced inflammation, demyelination, and axonal damage; however, FTY720 treatment did not prevent apoptosis of retinal ganglion cells (RGCs), the neurons that form the axons of the optic nerve. Consistent with this lack of effect on RGC survival, FTY720 treatment did not improve visual function, nor did it prevent apoptosis of RGCs in vitro. We observed a persistent activation of apoptotic signaling pathways in RGCs under FTY720 treatment, a possible underlying mechanism for the lack of neuroprotection in the presence of strong anti-inflammatory effects, Furthermore, FTY720 shifted the remaining inflammation in the optic nerve toward neurotoxicity by modest up-regulation of potential neurotoxic cytokines. We conclude that FTY720-induced anti-inflammation and axon protection did not of itself protect neurons from apoptotic cell death.     

FTY720 Reduces Endothelial Cell Apoptosis and Remodels Neurovascular Unit after Experimental Traumatic Brain Injury

Traumatic brain injury (TBI) is a major cause of death and disability worldwide. A sequence of pathological processes occurred when there is TBI. Previous studies showed that sphingosine-1-phosphate receptor 1 (S1PR1) played a critical role in inflammatory response in the brain after TBI. Thus, the present study was designed to evaluate the effects of the S1PR1 modulator FTY720 on neurovascular unit (NVU) after experimental TBI in mice. The weight-drop TBI method was used to induce TBI. Western blot (WB) was performed to determine the levels of SIPR1, claudin-5 and occludin at different time points. FTY720 was intraperitoneally administered to mice after TBI was induced. The terminal deoxynucleotidyl transferase-dUTP nick end labeling (TUNEL) assay was used to assess endothelial cell apoptosis. Immunofluorescence and WB were performed to measure the expression of tight junction proteins: claudin-5 and occludin. Evans blue (EB) permeability assay and brain water content were applied to evaluate the blood-brain barrier (BBB) permeability and brain edema. Immunohistochemistry was performed to assess the activation of astrocytes and microglia. The results showed that FTY720 administration reduced endothelial cell apoptosis and improved BBB permeability. FTY720 also attenuated astrocytes and microglia activation. Furthermore, treatment with FTY720 not only improved neurological function, but also increased the survival rate of mice significantly. These findings suggest that FTY720 administration restored the structure of the NVU after experimental TBI by decreasing endothelial cell apoptosis and attenuating the activation of astrocytes. Moreover, FTY720 might reduce inflammation in the brain by reducing the activation of microglia in TBI mice.     

FTY720 induces apoptosis in B16F10-NEX2 murine melanoma cells,limits metastatic development in vivo,and modulates the immune system

OBJECTIVE:

Available chemotherapy presents poor control over the development of metastatic melanoma. FTY720 is a compound already approved by the Food and Drug Administration for the treatment of patients with multiple sclerosis. It has also been observed that FTY720 inhibits tumor growth in vivo (experimental models) and in vitro (animal and human tumor cells). The aim of this study was to evaluate the effects of FTY720 on a metastatic melanoma model and in tumor cell lines.

METHODS:

We analyzed FTY720 efficacy in vivo in a syngeneic murine metastatic melanoma model, in which we injected tumor cells intravenously into C57BL/6 mice and then treated the mice orally with the compound for 7 days. We also treated mice and human tumor cell lines with FTY720 in vitro, and cell viability and death pathways were analyzed.

RESULTS:

FTY720 treatment limited metastatic melanoma growth in vivo and promoted a dose-dependent decrease in the viability of murine and human tumor cells in vitro. Melanoma cells treated with FTY720 exhibited characteristics of programmed cell death, reactive oxygen species generation, and increased β-catenin expression. In addition, FTY720 treatment resulted in an immunomodulatory effect in vivo by decreasing the percentage of Foxp3+ cells, without interfering with CD8+ T cells or lymphocyte-producing interferon-gamma.

CONCLUSION:

Further studies are needed using FTY720 as a monotherapy or in combined therapy, as different types of cancer cells would require a variety of signaling pathways to be extinguished.     

Effects of different dose of FTY720 on lymphocyte cell cycle arrest in cardiac transplantation model of rats

Purposes: To probe into immunosuppressive effect and cell cycle arrest effect of different dose of FTY720.

Method: we study immunosuppressive effect and cell cycle arrest effect of different dose of FTY720 and time and dose dependence of FTY720 with control and random method in vivo, respectively.

Results: (i) survival time of graft in rat cardiac transplantation model is prolonged in group treated with FTY720. It is longer in group treated with FTY720 10?mg/kg than that in group treated with FTY720 2?mg/kg. (ii) The mean sum of lymphocyte in periphery blood decrease obviously 2?h after administration, reaches its peak 4?h after administration, and then maintain at low level stably. The mean sum of lymphocyte shows a linear relationship with dose of FTY720 and decrease with increasing of dose of FTY720. (iii) The percent of cell in G1-G0 increased in group treated with FTY720, not only in thymus but also in lymph node; this is more prevalent in the group treated with FTY720 10?mg/kg than that in group treated with FTY720 2?mg/kg. Similarly, the percent of cell in S and G2-M decreased in group treated with FTY720, not only in thymus but also in lymph node, and this decrease is more associated with group treated with FTY720 10?mg/kg than the one treated with FTY720 2?mg/kg.

Conclusion: FTY720 is an effective immunosuppressant and immunosuppressive effect of FTY720 show a tendency of time and dose dependent. Effect of cell cycle arrest of FTY720 is related to dose of this new immunosuppressant.     

The immune modulator FYT720 prevents autoimmune diabetes in nonobese diabetic mice

FTY720 is a novel immune regulatory drug derived from the fungal sphingosine analog ISP-1 (myriocin). FTY720 causes a redistribution of lymphocytes from circulation to secondary lymphoid tissues. Type 1 diabetes is an autoimmune disorder caused by cellular-mediated destruction of insulin-producing pancreatic beta cells in the islets of Langerhans. Indeed, local infiltration of islets by mononuclear cells is the hallmark of Type 1 diabetes. Based on both FTY720's action and the involvement of cellular infiltration in the disease progression, we tested FTY720 for its ability to prevent autoimmune diabetes in diabetes-prone, nonobese diabetic (NOD) mice. We found that treatment with FTY720 completely prevented NOD mice from developing autoimmune diabetes. The FTY720-treated animals showed both reduced numbers of circulating lymphocytes and sharply diminished cellular infiltration of pancreatic islets. These results suggest that FTY720 may be effective in prevention of autoimmune diabetes or in slowing its progression.     

FTY720 attenuates hypoxia–reoxygenation-induced apoptosis in cardiomyocytes

FTY720, sphingosine 1 phosphate (S1P) receptor agonist, is a potent immunosuppressive agent. Numerous studies have documented a relationship between S1P and cardioprotection. We therefore hypothesized that a S1P analogue FTY720 would attenuate hypoxia/reoxygenation (H/R) induced cadiomyocyte apoptosis. H9C2 cardiomyocytes were employed to establish an in vitro model of H/R. Cells were treated or not with different doses of FTY720. Cell viability was measured by flow cytometry and TUNEL staining. Western blot was used to analyze downstream signaling pathway. We observed that FTY720 inhibits the expression of cleaved caspase-3 and activates both AKT and ERK1/2 pathways. AKT pathway can be blocked by MEK kinase inhibitor PD98059. ERK1/2 pathway can be blocked by the phosphoinositide-3 kinase inhibitor wortmannin. AKT and ERK1/2 activation can also be inhibited by S1P1/3 receptor antagonist VPC23019, Gi antagonist PTX. The protein levels of TNF-α and IL1ß were upregulated during hypoxia/reoxygenation and were attenuated by FTY720. We conclude that FTY720, via its cargo of S1P, can protect cardiomyocytes against hypoxia/reoxygenation injury. This effect is achieved by inhibiting caspase-3 expression, inflammatory cytokine levels and activating AKT and ERK1/2 signaling pathways. The prosurvival signal activation is dependent on S1P1, 3 subtype receptors and Gi protein.     

Immunomodulator FTY720 induces myofibroblast differentiation via the lysophospholipid receptor S1P3 and Smad3 signaling

The novel immunomodulator FTY720 is an effective immunosuppressive agent in experimental models of transplantation and autoimmunity and is currently undergoing phase III clinical trials for multiple sclerosis. Phosphorylated FTY720 is a structural analogue of sphingosine 1-phosphate (S1P) and therefore acts as a high-affinity agonist at four of the five G protein-coupled S1P receptors. It has been well established that there exists a crosstalk between S1P and transforming growth factor (TGF)-beta signaling. Because TGF-beta is the most prominent inductor of fibrosis and myofibroblasts are primarily responsible for excessive matrix protein formation, we examined whether FTY720, in analogy to TGF-beta, induces differentiation of fibroblasts into myofibroblasts. Indeed, FTY720 provoked myofibroblast differentiation comparable with that of TGF-beta. For biological efficacy, FTY720 required endogenous phosphorylation because inhibition of sphingosine kinase completely prevented FTY720 from inducing the differentiation process. Moreover, we identified the lysophospholipid receptor S1P3 as the crucial receptor subtype for FTY720-induced myofibroblast differentiation because the effect was abolished in fibroblasts isolated from S1P3 knockout mice. Finally, we determined that downstream of S1P3 signaling Smad3 activation is essential for myofibroblast differentiation in response to FTY720. Thus, FTY720 may have adverse fibrotic effects related to its activity on S1P3 signaling.