FTY720 modulates human oligodendrocyte progenitor process extension and survival.
TL;DR: The objective was to assess the effect of FTY720 on process extension, differentiation, and survival of human oligodendrocyte progenitor cells (OPCs), and link the functional effects with S1P receptor expression and signaling.
Abstract: Objective
FTY720, a sphingosine-1-phosphate (S1P) receptor agonist that crosses the blood–brain barrier, is a potential immuno-therapy for multiple sclerosis. Our objective was to assess the effect of FTY720 on process extension, differentiation, and survival of human oligodendrocyte progenitor cells (OPCs), and link the functional effects with S1P receptor expression and signaling.
Methods
Functional assays and receptor expression studies were conducted on A2B5+ OPCs derived from the human fetal central nervous system. Cells were treated with physiologically relevant concentrations of the active phosphorylated form of FTY720. S1P receptor/signaling modulators were used to elucidate the basis of the FTY720-induced functional responses.
Results
Short-term (1 day) FTY720 treatment caused initial process retraction that was reversed by uncoupling S1P3 and 5 from their G protein using suramin, and with a Rho-kinase inhibitor H1152. Retraction was associated with RhoA-mediated cytoskeletal signaling and with inhibition of OPC differentiation into more mature phenotypes. Continued FTY720 treatment (2 days) induced process extension and enhanced cell survival associated with increased extracellular signal-regulated kinases 1 and 2 phosphorylation, mimicked with the S1P1-specific agonist SEW2871, but not reversed with suramin. Quantitative real-time polymerase chain reaction showed that FTY720 induced reciprocal and cyclic modulation of S1P1 and S1P5 messenger RNA levels. The observed initial downregulation of S1P5 and subsequently of S1P1 messenger RNA supports functional responses being mediated sequentially by S1P5- and later S1P1-associated signaling.
Interpretation
FTY720 induces time-dependent modulation of S1P receptors on human OPCs with consequent functional responses that are directly relevant for the remyelination process. Ann Neurol 2007
Citations
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TL;DR: Both doses of oral fingolimod improved the relapse rate, the risk of disability progression, and end points on MRI and were superior to placebo with regard to MRI-related measures.
Abstract: Background Oral fingolimod, a sphingosine-1-phosphate–receptor modulator that prevents the egress of lymphocytes from lymph nodes, significantly improved relapse rates and end points measured on magnetic resonance imaging (MRI), as compared with either placebo or intramuscular interferon beta-1a, in phase 2 and 3 studies of multiple sclerosis. Methods In our 24-month, double-blind, randomized study, we enrolled patients who had relapsing–remitting multiple sclerosis, were 18 to 55 years of age, had a score of 0 to 5.5 on the Expanded Disability Status Scale (which ranges from 0 to 10, with higher scores indicating greater disability), and had had one or more relapses in the previous year or two or more in the previous 2 years. Patients received oral fingolimod at a dose of 0.5 mg or 1.25 mg daily or placebo. End points included the annualized relapse rate (the primary end point) and the time to disability progression (a secondary end point). Results A total of 1033 of the 1272 patients (81.2%) completed the study. The annualized relapse rate was 0.18 with 0.5 mg of fingolimod, 0.16 with 1.25 mg of fingolimod, and 0.40 with placebo (P<0.001 for either dose vs. placebo). Fingolimod at doses of 0.5 mg and 1.25 mg significantly reduced the risk of disability progression over the 24-month period (hazard ratio, 0.70 and 0.68, respectively; P = 0.02 vs. placebo, for both comparisons). The cumulative probability of disability progression (confirmed after 3 months) was 17.7% with 0.5 mg of fingolimod, 16.6% with 1.25 mg of fingolimod, and 24.1% with placebo. Both fingolimod doses were superior to placebo with regard to MRIrelated measures (number of new or enlarged lesions on T2 -weighted images, gadolinium-enhancing lesions, and brain-volume loss; P<0.001 for all comparisons at 24 months). Causes of study discontinuation and adverse events related to fingolimod included bradycardia and atrioventricular conduction block at the time of fingolimod initiation, macular edema, elevated liver-enzyme levels, and mild hypertension. Conclusions As compared with placebo, both doses of oral fingolimod improved the relapse rate, the risk of disability progression, and end points on MRI. These benefits will need to be weighed against possible long-term risks. (ClinicalTrials.gov number, NCT00289978.)
2,363 citations
TL;DR: This trial showed the superior efficacy of oral fingolimod with respect to relapse rates and MRI outcomes in patients with multiple sclerosis, as compared with intramuscular interferon beta-1a.
Abstract: BACKGROUND: Fingolimod (FTY720), a sphingosine-1-phosphate-receptor modulator that prevents lymphocyte egress from lymph nodes, showed clinical efficacy and improvement on imaging in a phase 2 study involving patients with multiple sclerosis. METHODS: In this 12-month, double-blind, double-dummy study, we randomly assigned 1292 patients with relapsing-remitting multiple sclerosis who had a recent history of at least one relapse to receive either oral fingolimod at a daily dose of either 1.25 or 0.5 mg or intramuscular interferon beta-1a (an established therapy for multiple sclerosis) at a weekly dose of 30 microg. The primary end point was the annualized relapse rate. Key secondary end points were the number of new or enlarged lesions on T(2)-weighted magnetic resonance imaging (MRI) scans at 12 months and progression of disability that was sustained for at least 3 months. RESULTS: A total of 1153 patients (89%) completed the study. The annualized relapse rate was significantly lower in both groups receiving fingolimod--0.20 (95% confidence interval [CI], 0.16 to 0.26) in the 1.25-mg group and 0.16 (95% CI, 0.12 to 0.21) in the 0.5-mg group--than in the interferon group (0.33; 95% CI, 0.26 to 0.42; P<0.001 for both comparisons). MRI findings supported the primary results. No significant differences were seen among the study groups with respect to progression of disability. Two fatal infections occurred in the group that received the 1.25-mg dose of fingolimod: disseminated primary varicella zoster and herpes simplex encephalitis. Other adverse events among patients receiving fingolimod were nonfatal herpesvirus infections, bradycardia and atrioventricular block, hypertension, macular edema, skin cancer, and elevated liver-enzyme levels. CONCLUSIONS: This trial showed the superior efficacy of oral fingolimod with respect to relapse rates and MRI outcomes in patients with multiple sclerosis, as compared with intramuscular interferon beta-1a. Longer studies are needed to assess the safety and efficacy of treatment beyond 1 year. (ClinicalTrials.gov number, NCT00340834.)
2,040 citations
TL;DR: The discovery and development of fingolimod is described, which was approved by the US Food and Drug Administration in September 2010 as a first-line treatment for relapsing forms of multiple sclerosis, thereby becoming the first oral disease-modifying therapy to be approved for multiple sclerosis in the United States.
Abstract: The discovery of fingolimod (FTY720/Gilenya; Novartis), an orally active immunomodulatory drug, has opened up new approaches to the treatment of multiple sclerosis, the most common inflammatory disorder of the central nervous system. Elucidation of the effects of fingolimod--mediated by the modulation of sphingosine 1-phosphate (S1P) receptors--has indicated that its therapeutic activity could be due to regulation of the migration of selected lymphocyte subsets into the central nervous system and direct effects on neural cells, particularly astrocytes. An improved understanding of the biology of S1P receptors has also been gained. This article describes the discovery and development of fingolimod, which was approved by the US Food and Drug Administration in September 2010 as a first-line treatment for relapsing forms of multiple sclerosis, thereby becoming the first oral disease-modifying therapy to be approved for multiple sclerosis in the United States.
1,075 citations
TL;DR: Evidence is provided that a differentiation block of oligodendroglial progenitors is a major determinant of remyelination failure in chronic multiple sclerosis lesions.
Abstract: Impaired function/differentiation of progenitor cells might provide an explanation for the limited remyelination observed in the majority of chronic multiple sclerosis lesions. Here, we establish that in the normal adult human CNS, the transcription factors Nkx2.2 and Olig2 are strongly expressed in progenitor cells while mature oligodendrocytes are characterized by low levels of Olig2 or Nkx2.2. In vitro studies confirmed the expression of Olig2 in oligodendroglial progenitor cells and mature oligodendrocytes while astrocytes, microglial cells and neurons were negative for Olig2. In early multiple sclerosis lesions, we found Olig2-positive progenitor cells throughout all lesion stages and in periplaque white matter (PPWM). The number of progenitors in PPWM was significantly increased compared with the white matter from controls. In chronic multiple sclerosis lesions progenitor cells were still present, however, in significantly lower numbers than in early multiple sclerosis lesions. A subpopulation of progenitor cells in early multiple sclerosis lesions and PPWM but not in control cases co-expressed NogoA, a marker of mature oligodendrocytes. The co-expression of these two markers suggested that these cells were maturing oligodendrocytes recently recruited from the progenitor pool. In contrast, in chronic multiple sclerosis lesions maturing progenitors were only rarely present. In summary, we provide evidence that a differentiation block of oligodendroglial progenitors is a major determinant of remyelination failure in chronic multiple sclerosis lesions.
723 citations
Cites background or methods from "FTY720 modulates human oligodendroc..."
...Human foetal OPCs were isolated as previously described (Miron et al., 2008)....
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...Our previous studies have characterized the purity of these cultures (Miron et al., 2007, 2008)....
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TL;DR: Fingolimod crosses the blood-brain barrier and may therefore have direct CNS effects, distinguishing it from immunologically targeted MS therapies, andTherapeutic efficacy observed in animal studies has been substantiated in phase 2 and 3 trials involving patients with relapsesing or relapsing-remitting MS.
Abstract: Fingolimod (FTY720) is a first-in-class orally bioavailable compound that has shown efficacy in advanced clinical trials for the treatment of multiple sclerosis (MS). In vivo, fingolimod is phosphorylated to form fingolimod-phosphate, which resembles naturally occurring sphingosine 1-phosphate (S1P), an extracellular lipid mediator whose major effects are mediated by cognate G protein-coupled receptors. There are at least 5 S1P receptor subtypes, known as S1P subtypes 1-5 (S1P1-5), 4 of which bind fingolimod-phosphate. These receptors are expressed on a wide range of cells that are involved in many biological processes relevant to MS. S1P1 plays a key role in the immune system, regulating lymphocyte egress from lymphoid tissues into the circulation. Fingolimod-phosphate initially activates lymphocyte S1P1 via high-affinity receptor binding yet subsequently induces S1P1 down-regulation that prevents lymphocyte egress from lymphoid tissues, thereby reducing autoaggressive lymphocyte infiltration into the central nervous system (CNS). S1P receptors are also expressed by many CNS cell types and have been shown to influence cell proliferation, morphology, and migration. Fingolimod crosses the blood-brain barrier and may therefore have direct CNS effects, distinguishing it from immunologically targeted MS therapies. Prophylactic administration of fingolimod to animals with experimental autoimmune encephalitis (EAE), a model of MS, completely prevents development of EAE features, whereas therapeutic administration significantly reduces clinical severity of EAE. Therapeutic efficacy observed in animal studies has been substantiated in phase 2 and 3 trials involving patients with relapsing or relapsing-remitting MS.
685 citations
Cites background from "FTY720 modulates human oligodendroc..."
...These effects could alter the myelination or remyelination processes.(59)...
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...S1P5 and the S1P1 are both expressed on oligodendrocytes, and their relative levels of expression seem to depend on the developmental stages of the cell.(59,96) Activation of S1P receptor subtypes initiates distinct intracellular signaling pathways that can produce opposing effects....
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...1).29,35,38Y40,61,62,64,70 Fingolimod exerts its therapeutic effects through modulation of S1P receptors by fingolimod-phosphate and may well achieve its beneficial effects in patients with MS through receptor-mediated actions both on the immune system and in the CNS.4,39,46,59,70 Role of S1P Receptors in Lymphocyte Recirculation Sphingosine 1-phosphate and S1P receptors play important roles in normal immune function....
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...Fingolimod exposure in vitro has also been reported to increase the number of both progenitor and mature oligodendrocytes, to protect oligodendrocytes from cell death induced by cytokines or the withdrawal of growth factors, and to modulate process outgrowth (both retraction and extension).(59,101,102) The effects of fingolimod on human oligodendrocytes and process extension/retraction were found to be time, dose, and stage dependent, which may in part reflect the relative levels of expression of the relevant receptors....
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...Patterns of expression of S1P receptors can change with the activation and functional status of cells.(59,60) Sphingosine 1-phosphate receptors are involved in multiple biological processes, including leukocyte recirculation, neural cell proliferation, morphological changes, migration, endothelial cell function, vasoregulation, and cardiovascular development, as summarized in Table 1....
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References
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TL;DR: It is shown that lymphocyte trafficking is altered by the lysophospholipid sphingosine-1-phosphate (S1P) and by a phosphoryl metabolites of the immunosuppressive agent FTY720.
Abstract: Blood lymphocyte numbers, essential for the development of efficient immune responses, are maintained by recirculation through secondary lymphoid organs. We show that lymphocyte trafficking is altered by the lysophospholipid sphingosine-1-phosphate (S1P) and by a phosphoryl metabolite of the immunosuppressive agent FTY720. Both species were high-affinity agonists of at least four of the five S1P receptors. These agonists produce lymphopenia in blood and thoracic duct lymph by sequestration of lymphocytes in lymph nodes, but not spleen. S1P receptor agonists induced emptying of lymphoid sinuses by retention of lymphocytes on the abluminal side of sinus-lining endothelium and inhibition of egress into lymph. Inhibition of lymphocyte recirculation by activation of S1P receptors may result in therapeutically useful immunosuppression.
1,641 citations
"FTY720 modulates human oligodendroc..." refers background in this paper
...FTY720 is an agonist of four of five known G-protein–coupled receptors, termed S1P1, 3, 4, and 5, that are part of the endothelial differentiation gene-related (Edg) family.(12,13) Edg receptor messenger RNA (mRNA) levels are upregulated around the perimeter of MS brain lesions....
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TL;DR: In this proof-of-concept study, fingolimod reduced the number of lesions detected on MRI and clinical disease activity in patients with multiple sclerosis and both measures decreased in patients who switched from placebo to fingolIMod.
Abstract: Background Fingolimod (FTY720) is a new oral immunomodulating agent under evaluation for the treatment of relapsing multiple sclerosis. Methods We randomly assigned 281 patients to receive oral fingolimod, at a dose of 1.25 mg or 5.0 mg, or a placebo once daily, and we followed these patients for 6 months with magnetic resonance imaging (MRI) and clinical evaluations (core study, months 0 to 6). The primary end point was the total number of gadolinium-enhanced lesions recorded on T1-weighted MRI at monthly intervals for 6 months. In an extension study in which the investigators and patients remained unaware of the dose assignments (months 7 to 12), patients who received placebo underwent randomization again to one of the fingolimod doses. Results A total of 255 patients completed the core study. The median total number of gadolinium-enhanced lesions on MRI was lower with 1.25 mg of fingolimod (1 lesion, P<0.001) and 5.0 mg of fingolimod (3 lesions, P=0.006) than with placebo (5 lesions). The annualized re...
1,025 citations
"FTY720 modulates human oligodendroc..." refers background in this paper
...FTY720, a lipophilic sphingosine-1-phosphate (S1P) analogue that crosses the blood–brain barrier,(10) is being evaluated as a potential therapy for MS because of its antiinflammatory properties.(11) FTY720 is an agonist of four of five known G-protein–coupled receptors, termed S1P1, 3, 4, and 5, that are part of the endothelial differentiation gene-related (Edg) family....
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TL;DR: Why remyelination fails is crucial for devising effective methods by which to enhance it, and as the disease progresses, the numbers of lesions in which demyelinations persists increases, significantly contributing to clinical deterioration.
Abstract: Multiple sclerosis is a common cause of neurological disability in young adults. The disease is complex — its aetiology is multifactorial and largely unknown; its pathology is heterogeneous; and, clinically, it is difficult to diagnose, manage and treat. However, perhaps its most frustrating aspect is the inadequacy of the healing response of remyelination. This regenerative process generally occurs with great efficiency in experimental models, and sometimes proceeds to completion in multiple sclerosis. But as the disease progresses, the numbers of lesions in which demyelination persists increases, significantly contributing to clinical deterioration. Understanding why remyelination fails is crucial for devising effective methods by which to enhance it.
800 citations
"FTY720 modulates human oligodendroc..." refers background in this paper
...Results from experimental models of central nervous system (CNS) demyelination indicate that remyelination is dependent on oligodendrocyte progenitor cells (OPCs) rather than on previously myelinating oligodendrocytes.(3,4) Myelin lineage progenitor cells have been identified in both the normal adult human CNS and in MS lesions....
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TL;DR: In this paper, a method of producing neuronal progenitor cells by providing an isolated population of progenitors cells from human brain white matter and permitting the isolated populations of cells to differentiate to neuronal cells was proposed.
Abstract: The present invention is directed to a method of producing neuronal progenitor cells by providing an isolated population of progenitor cells from human brain white matter and permitting the isolated population of cells to differentiate to neuronal progenitor cells. Alternatively, neuronal progenitor cells can be produced by providing an isolated population of glial progenitor cells and permitting the isolated population of glial progenitor cells to differentiate to neuronal progenitor cells.
684 citations
TL;DR: The data indicate that activation of innate immune responses in the CNS is not homogeneous but rather tailored according to cell type and environmental signal.
Abstract: The specific signals mediating the activation of microglia and astrocytes as a prelude to, or consequence of, CNS inflammation continue to be defined. We investigated TLRs as novel receptors mediating innate immune responses in human glial cells. We find that microglia express mRNA for TLRs 1-9, whereas astrocytes express robust TLR3, low-level TLR 1, 4, 5, and 9, and rare-to-undetectable TLR 2, 6, 7, 8, and 10 mRNA (quantitative real-time PCR). We focused on TLRs 3 and 4, which can signal through both the MyD88-dependent and -independent pathways, and on the MyD88-restricted TLR2. By flow cytometry, we established that microglia strongly express cell surface TLR2; TLR3 is expressed at higher levels intracellularly. Astrocytes express both cell surface and intracellular TLR3. All three TLRs trigger microglial activation upon ligation. TLR3 signaling induces the strongest proinflammatory polarizing response, characterized by secretion of high levels of IL-12, TNF-alpha, IL-6, CXCL-10, and IL-10, and the expression of IFN-beta. CXCL-10 and IL-10 secretion following TLR4 ligation are comparable to that of TLR3; however, other responses were lower or absent. TLR2-mediated responses are dominated by IL-6 and IL-10 secretion. Astrocytes respond to TLR3 ligation, producing IL-6, CXCL-10, and IFN-beta, implicating these cells as contributors to proinflammatory responses. Initial TLR-mediated glial activation also regulates consequent TLR expression; while TLR2 and TLR3 are subject to positive feedback, TLR4 is down-regulated in microglia. Astrocytes up-regulate all three TLRs following TLR3 ligation. Our data indicate that activation of innate immune responses in the CNS is not homogeneous but rather tailored according to cell type and environmental signal.
658 citations
"FTY720 modulates human oligodendroc..." refers methods in this paper
...Actin transcript levels were used as endogenous controls for the amount of RNA transcribed, and primers/ probes were designed using the PRIMER express software.(32) All S1P receptor levels were normalized to the actin levels in the corresponding sample....
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