sphingosine-1-phosphate and Multiple-Sclerosis

Abuse and misuse of prescription drugs remains an ongoing concern in the USA and worldwide; thus, all centrally active new drugs must be assessed for abuse and dependence potential. Sphingosine-1-phosphate (S1P) receptor modulators are used primarily in the treatment of multiple sclerosis. Among the new S1P receptor modulators, siponimod, ozanimod, and ponesimod have recently been approved in the USA, European Union (EU), and other countries. This review of literature and other public data has been undertaken to assess the potential for abuse of S1P receptor modulators, including ozanimod, siponimod, ponesimod, and fingolimod, as well as several similar compounds in development. The S1P receptor modulators have not shown chemical or pharmacological similarity to known drugs of abuse; have not shown abuse or dependence potential in animal models for subjective effects, reinforcement, or physical dependence; and do not have adverse event profiles demonstrating effects of interest to individuals who abuse drugs (such as sedative, stimulant, mood-elevating, or hallucinogenic effects). In addition, no reports of actual abuse, misuse, or dependence were identified in the scientific literature for fingolimod, which has been on the market since 2010 (USA) and 2011 (EU). Overall, the data suggest that S1P receptor modulators are not associated with significant potential for abuse or dependence, consistent with their unscheduled status in the USA and internationally.

Topics: Animals; Humans; Lysophospholipids; Multiple Sclerosis; Sphingosine; Sphingosine 1 Phosphate Receptor Modulators

Sphingosine-1-phosphate (S1P) and S1P receptors (S1PR) are bioactive lipid molecules that are ubiquitously expressed in the human body and play an important role in the immune system. S1P-S1PR signaling has been well characterized in immune trafficking and activation in both innate and adaptive immune systems. Despite this knowledge, the full scope in the pathogenesis of autoimmune disorders is not well characterized yet. From the discovery of fingolimod, the first S1P modulator, until siponimod, the new molecule recently approved for the treatment of secondary progressive multiple sclerosis (SPMS), there has been a great advance in understanding the S1P functions and their involvement in immune diseases, including multiple sclerosis (MS). Modulation on S1P is an interesting target for the treatment of various autoimmune disorders. Improved understanding of the mechanism of action of fingolimod has allowed the development of the more selective second-generation S1PR modulators. Subtype 1 of the S1PR (S1PR1) is expressed on the cell surface of lymphocytes, which are known to play a major role in MS pathogenesis. The understanding of S1PR1's role facilitated the development of pharmacological strategies directed to this target, and theoretically reduced the safety concerns derived from the use of fingolimod. A great advance in the MS treatment was achieved in March 2019 when the Food and Drug Association (FDA) approved Siponimod, for both active secondary progressive MS and relapsing-remitting MS. Siponimod became the first oral disease modifying therapy (DMT) specifically approved for active forms of secondary progressive MS. Additionally, for the treatment of relapsing forms of MS, ozanimod was approved by FDA in March 2020. Currently, there are ongoing trials focused on other new-generation S1PR1 modulators. This review approaches the fundamental aspects of the sphingosine phosphate modulators and their main similarities and differences.

Topics: Autoimmune Diseases; Fingolimod Hydrochloride; Humans; Lysophospholipids; Multiple Sclerosis; Receptors, Lysosphingolipid; Signal Transduction; Sphingosine

Sphingosine 1-phosphate (S1P) is a signaling molecule with complex biological functions that are exerted through the activation of sphingosine 1-phosphate receptors 1-5 (S1PR1-5). S1PR expression is necessary for cell proliferation, angiogenesis, neurogenesis and, importantly, for the egress of lymphocytes from secondary lymphoid organs. Since the inflammatory process is a key element of immune-mediated diseases, including multiple sclerosis (MS), S1PR modulators are currently used to ameliorate systemic immune responses. The ubiquitous expression of S1PRs by immune, intestinal and neural cells has significant implications for the regulation of the gut-brain axis. The dysfunction of this bidirectional communication system may be a significant factor contributing to MS pathogenesis, since an impaired intestinal barrier could lead to interaction between immune cells and microbiota with a potential to initiate abnormal local and systemic immune responses towards the central nervous system (CNS). It appears that the secondary mechanisms of S1PR modulators affecting the gut immune system, the intestinal barrier and directly the CNS, are coordinated to promote therapeutic effects. The scope of this review is to focus on S1P-S1PR functions in the cells of the CNS, the gut and the immune system with particular emphasis on the immunologic effects of S1PR modulation and its implication in MS.

Topics: Animals; Brain-Gut Axis; Central Nervous System; Humans; Immune System; Lysophospholipids; Multiple Sclerosis; Signal Transduction; Sphingosine; Sphingosine-1-Phosphate Receptors

Therapeutically controlling chronic progression in multiple sclerosis (MS) remains a major challenge. MS progression is defined as a steady loss of parenchymal and functional integrity of the central nervous system (CNS), occurring independent of relapses or focal, magnetic resonance imaging (MRI)-detectable inflammatory lesions. While it clinically surfaces in primary or secondary progressive MS, it is assumed to be an integral component of MS from the very beginning. The exact mechanisms causing progression are still unknown, although evolving evidence suggests that they may substantially differ from those driving relapse biology. To date, progression is assumed to be caused by an interplay of CNS-resident cells and CNS-trapped hematopoietic cells. On the CNS-resident cell side, microglia that are phenotypically and functionally related to cells of the monocyte/macrophage lineage may play a key role. Microglia function is highly transformable. Depending on their molecular signature, microglia can trigger neurotoxic pathways leading to neurodegeneration, or alternatively exert important roles in promoting neuroprotection, downregulation of inflammation, and stimulation of repair. Accordingly, to understand and to possibly alter the role of microglial activation during MS disease progression may provide a unique opportunity for the development of suitable, more effective therapeutics. This review focuses on the current understanding of the role of microglia during disease progression of MS and discusses possible targets for therapeutic intervention.

Topics: Agammaglobulinaemia Tyrosine Kinase; Animals; Antibodies, Monoclonal, Humanized; Biomarkers; CX3C Chemokine Receptor 1; Disease Progression; Down-Regulation; Humans; Inflammation; Lysophospholipids; Macrophages; Magnetic Resonance Imaging; Membrane Glycoproteins; Microglia; Monocytes; Multiple Sclerosis; Neuroprotective Agents; Phenotype; Receptors, Granulocyte-Macrophage Colony-Stimulating Factor; Receptors, Immunologic; Receptors, Purinergic P2X; Sphingosine

Sphingosine-1-phosphate (S1P) is a bioactive lipid metabolite that exerts its actions by engaging 5 G-protein-coupled receptors (S1PR1-S1PR5). S1P receptors are involved in several cellular and physiological events, including lymphocyte/hematopoietic cell trafficking. An S1P gradient (low in tissues, high in blood), maintained by synthetic and degradative enzymes, regulates lymphocyte trafficking. Because lymphocytes live long (which is critical for adaptive immunity) and recirculate thousands of times, the S1P-S1PR pathway is involved in the pathogenesis of immune-mediated diseases. The S1PR1 modulators lead to receptor internalization, subsequent ubiquitination, and proteasome degradation, which renders lymphocytes incapable of following the S1P gradient and prevents their access to inflammation sites. These drugs might also block lymphocyte egress from lymph nodes by inhibiting transendothelial migration. Targeting S1PRs as a therapeutic strategy was first employed for multiple sclerosis (MS), and four S1P modulators (fingolimod, siponimod, ozanimod, and ponesimod) are currently approved for its treatment. New S1PR modulators are under clinical development for MS, and their uses are being evaluated to treat other immune-mediated diseases, including inflammatory bowel disease (IBD), rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and psoriasis. A clinical trial in patients with COVID-19 treated with ozanimod is ongoing. Ozanimod and etrasimod have shown promising results in IBD; while in phase 2 clinical trials, ponesimod has shown improvement in 77% of the patients with psoriasis. Cenerimod and amiselimod have been tested in SLE patients. Fingolimod, etrasimod, and IMMH001 have shown efficacy in RA preclinical studies. Concerns relating to S1PR modulators are leukopenia, anemia, transaminase elevation, macular edema, teratogenicity, pulmonary disorders, infections, and cardiovascular events. Furthermore, S1PR modulators exhibit different pharmacokinetics; a well-established first-dose event associated with S1PR modulators can be mitigated by gradual up-titration. In conclusion, S1P modulators represent a novel and promising therapeutic strategy for immune-mediated diseases.

Topics: Animals; Humans; Immune System Diseases; Lysophospholipids; Multiple Sclerosis; Pharmaceutical Preparations; Signal Transduction; Sphingosine

Sphingosine-1-phosphate signaling is emerging as a critical regulator of cellular processes that is initiated by the intracellular production of bioactive lipid molecule, sphingosine-1-phosphate. Binding of sphingosine-1-phosphate to its extracellular receptors activates diverse downstream signaling that play a critical role in governing physiological processes. Increasing evidence suggests that this signaling pathway often gets impaired during pathophysiological and diseased conditions and hence manipulation of this signaling pathway may be beneficial in providing treatment. In this review, we summarized the recent findings of S1P signaling pathway and the versatile role of the participating candidates in context with several disease conditions. Finally, we discussed its possible role as a novel drug target in different diseases.

Topics: Arthritis, Rheumatoid; Ceramidases; Diabetes Mellitus; Humans; Lysophospholipids; Molecular Targeted Therapy; Multiple Sclerosis; Neoplasms; Phosphotransferases (Alcohol Group Acceptor); Signal Transduction; Sphingosine

Multiple sclerosis (MS) is a prototype autoimmune disease of the central nervous system (CNS). Currently, there is no drug that provides a cure for MS. To date, all immunotherapeutic drugs target relapsing remitting MS (RR-MS); it remains a daunting medical challenge in MS to develop therapy for secondary progressive MS (SP-MS). Since the approval of the non-selective sphingosine-1-phosphate (S1P) receptor modulator FTY720 (fingolimod [Gilenya®]) for RR-MS in 2010, there have been many emerging studies with various selective S1P receptor modulators in other autoimmune conditions. In this article, we will review how S1P receptor may be a promising therapeutic target for SP-MS and other autoimmune diseases such as psoriasis, polymyositis and lupus.

Topics: Animals; Autoimmune Diseases; Central Nervous System; Humans; Lysophospholipids; Multiple Sclerosis; Multiple Sclerosis, Chronic Progressive; Receptors, Lysosphingolipid; Sphingosine

Lysophospholipids (LPs), including lysophosphatidic acid (LPA), sphingosine 1-phospate (S1P), lysophosphatidylinositol (LPI), and lysophosphatidylserine (LysoPS), are bioactive lipids that transduce signals through their specific cell-surface G protein-coupled receptors, LPA1-6, S1P1-5, LPI1, and LysoPS1-3, respectively. These LPs and their receptors have been implicated in both physiological and pathophysiological processes such as autoimmune diseases, neurodegenerative diseases, fibrosis, pain, cancer, inflammation, metabolic syndrome, bone formation, fertility, organismal development, and other effects on most organ systems. Advances in the LP receptor field have enabled the development of novel small molecules targeting LP receptors for several diseases. Most notably, fingolimod (FTY720, Gilenya, Novartis), an S1P receptor modulator, became the first FDA-approved medicine as an orally bioavailable drug for treating relapsing forms of multiple sclerosis. This success is currently being followed by multiple, mechanistically related compounds targeting S1P receptor subtypes, which are in various stages of clinical development. In addition, an LPA1 antagonist, BMS-986020 (Bristol-Myers Squibb), is in Phase 2 clinical development for treating idiopathic pulmonary fibrosis, as a distinct compound, SAR100842 (Sanofi) for the treatment of systemic sclerosis and related fibrotic diseases. This review summarizes the current state of drug discovery in the LP receptor field.

Topics: Animals; Drug Discovery; Humans; Lysophospholipids; Molecular Targeted Therapy; Multiple Sclerosis; Receptors, Lysophosphatidic Acid; Receptors, Lysosphingolipid; Signal Transduction; Sphingosine

Membrane sphingolipids are metabolized to sphingosine-1-phosphate (S1P), a bioactive lipid mediator that regulates many processes in vertebrate development, physiology, and pathology. Once exported out of cells by cell-specific transporters, chaperone-bound S1P is spatially compartmentalized in the circulatory system. Extracellular S1P interacts with five GPCRs that are widely expressed and transduce intracellular signals to regulate cellular behavior, such as migration, adhesion, survival, and proliferation. While many organ systems are affected, S1P signaling is essential for vascular development, neurogenesis, and lymphocyte trafficking. Recently, a pharmacological S1P receptor antagonist has won approval to control autoimmune neuroinflammation in multiple sclerosis. The availability of pharmacological tools as well as mouse genetic models has revealed several physiological actions of S1P and begun to shed light on its pathological roles. The unique mode of signaling of this lysophospholipid mediator is providing novel opportunities for therapeutic intervention, with possibilities to target not only GPCRs but also transporters, metabolic enzymes, and chaperones.

Topics: Acute Lung Injury; Anemia, Sickle Cell; Animals; Autoimmune Diseases; Cardiovascular Diseases; Cell Physiological Phenomena; Disease Models, Animal; Fingolimod Hydrochloride; Hematopoietic Stem Cell Mobilization; Humans; Influenza, Human; Lysophospholipids; Membrane Lipids; Mice; Multiple Sclerosis; Neoplasms; Neovascularization, Physiologic; Neurogenesis; Propylene Glycols; Receptors, Lysosphingolipid; Sphingolipids; Sphingosine

The understanding of the role of the sphingosine 1-phosphate signaling system in immunology and host defense has deepened exponentially over the past 12 years since the discovery that lymphocyte egress was reversibly modulated by sphingosine 1-phosphate receptors, and with the development of fingolimod, a prodrug of a nonselective S1P receptor agonist, for therapeutic use in the treatment of relapsing, remitting multiple sclerosis. Innovative genetic and chemical approaches, together with structural biology, now provide a more detailed molecular understanding of a regulated lysophospholipid ligand with a variety of autocrine, paracrine, and systemic effects in physiology and pathology, based upon selective interactions with a high affinity and selective evolutionary cluster of G-protein-coupled receptors.

Topics: Animals; Humans; Lysophospholipids; Multiple Sclerosis; Receptors, Lysosphingolipid; Signal Transduction; Sphingosine

Multiple Sclerosis (MS) is the most common cause for permanent disability in young adults. Current pathophysiological understanding has identified an autoaggressive immune reaction with infiltration of immune cells into the central nervous system and local inflammatory and demyelinating reactions. The current therapy focuses on a modulation or suppression of immune functions. Sphingolipids, main components of nervous tissue, have been linked to MS already 60 years ago with the description of an unusual myelin lipid distribution in diseased patients. There is tremendous information developing on the role of different sphingolipids in MS. Antibodies against sphingomyelin, sulfatide or galacosylceramide have been detected in serum or CSF of MS patients, although up to now, this knowledge did not find its way into clinical use. Ceramide and the enzymes linked to its production have been described to play a pivotal role in oligendrocyte damage and demyelination. Nowadays, especially sphingosine-1-phosphate (S1P) is in the focus of pathophysiological research and therapy development. A S1P analogue, FTY720, is a widely distributed therapy against relapsing-remitting MS, attenuating the emigration of activated, autoreactive lymphocytes from lymph nodes, thereby preventing new inflammatory infiltration into the central nervous system. Beside, there is more and more evidence, that especially S1P receptors on oligodendrocytes and astrocytes are involved in demyelination processes and subsequent axonal degeneration, important features of chonic progressive MS disease course. Further information and research on the manifold role of sphingolipids are needed to prepare the ground for further clinical trials. This review focuses on the current knowledge of the role of sphingolipids in MS and describes the current therapeutical implications.

Topics: Ceramides; Fingolimod Hydrochloride; Humans; Immunosuppressive Agents; Lysophospholipids; Multiple Sclerosis; Propylene Glycols; Sphingolipids; Sphingomyelin Phosphodiesterase; Sphingomyelins; Sphingosine

Because of its potent efficacy and oral route of administration, the approval of fingolimod as treatment for relapsing-remitting multiple sclerosis (MS) was highly anticipated. The therapeutic and adverse effects are mediated by modulation of sphingosine 1-phosphate receptors. Fingolimod inhibits the egress of lymphocytes from lymph nodes and may also have direct effects on the central nervous system. The clinical trials that led to the approval of fingolimod demonstrated benefit on relapses, disability progression, magnetic resonance imaging (MRI) activity, and brain volume loss in treatment-naïve and previously treated patients with relapsing-remitting MS. The use of fingolimod in clinical practice has been limited by concerns for cardiac effects, infection, and macular edema as well as the relative lack of long-term safety data for this drug with a novel mechanism of action. Additional clinical trial and postmarketing data suggest that fingolimod is a safe, effective, and well-tolerated treatment option when patients are selected and monitored appropriately.

Topics: Central Nervous System; Fingolimod Hydrochloride; Humans; Immunosuppressive Agents; Lysophospholipids; Multiple Sclerosis; Propylene Glycols; Sphingosine; Treatment Outcome

Sphingosine 1-phosphate (S1P) is a lipid mediator produced from sphingomyelin by the sequential enzymatic actions of sphingomyelinase, ceramidase, and sphingosine kinase. Five subtypes of cell surface G-protein-coupled receptors, S1P(1-5), mediate the actions of S1P in various organs systems, most notably cardiovascular, immune, and central nervous systems. S1P is enriched in blood and lymph but is present at much lower concentrations in interstitial fluids of tissues. This vascular S1P gradient is important for the regulation of trafficking of various immune cells. FTY720, which was recently approved for the treatment of relapsing-remitting multiple sclerosis, potently sequesters lymphocytes into lymph nodes by functionally antagonizing the activity of the S1P(1) receptor. S1P also plays critical roles in the vascular barrier integrity, thereby regulating inflammation, tumor metastasis, angiogenesis, and atherosclerosis. Recent studies have also revealed the involvement of S1P signaling in coagulation and in tumor necrosis factor α-mediated signaling. This review highlights the importance of S1P signaling in these inflammatory processes as well as the contribution of each receptor subtype, which exhibits both cooperative and redundant functions.

Topics: Animals; Atherosclerosis; Blood Coagulation; Fingolimod Hydrochloride; Humans; Immunosuppressive Agents; Inflammation; Lymph Nodes; Lymphocytes; Lysophospholipids; Multiple Sclerosis; Neoplasm Metastasis; Neoplasms; Neovascularization, Pathologic; Propylene Glycols; Receptors, Lysosphingolipid; Signal Transduction; Sphingosine; Tumor Necrosis Factor-alpha

FTY720 (fingolimod; Gilenya®), a sphingosine 1-phosphate (S1P) receptor modulator, is the first oral disease-modifying therapy to be approved for the treatment of relapsing-remitting multiple sclerosis. FTY720 is rapidly converted in vivo to the active S-fingolimod-phosphate, which binds to S1P receptors. This action inhibits egress of lymphocytes from the lymph nodes, preventing entry into the blood and thus infiltration into the central nervous system. More recent studies, however, convincingly show that FTY720 crosses the blood-brain barrier, where it is thought to act on S1P receptors on cells within the central nervous system, such as astrocytes, oligodendrocytes or microglia. Here we discuss the evidence showing that FTY720 also plays a role in remyelination and repair within the brain. While the mechanisms of action still require firm elucidation, it is clear that FTY720 could also be reparative, extending its therapeutic potential for multiple sclerosis.

Topics: Animals; Astrocytes; Axons; Central Nervous System; Disease Models, Animal; Fingolimod Hydrochloride; Humans; Lysophospholipids; Mice; Microglia; Multiple Sclerosis; Myelin Sheath; Neurons; Oligodendroglia; Propylene Glycols; Rats; Receptors, Lysosphingolipid; Sphingosine

Spingolipids (SLs) are an important component of central nervous system (CNS) myelin sheaths and affect the viability of brain cells (oligodendrocytes, neurons and astrocytes) that is determined by signaling mediated by bioactive sphingoids (lyso-SLs). Recent studies indicate that two lipids, ceramide and sphingosine 1-phosphate (S1P), are particularly involved in many human diseases including the autoimmune inflammatory demyelination of multiple sclerosis (MS). In this review we: (1) Discuss possible sources of ceramide in CNS; (2) Summarize the features of the metabolism of S1P and its downstream signaling through G-protein-coupled receptors; (3) Link perturbations in bioactive SLs metabolism to MS neurodegeneration and (4) Compile ceramide and S1P relationships to this process. In addition, we described recent preclinical and clinical trials of therapies targeting S1P signaling, including 2-amino-2-propane-1,3-diol hydrochloride (FTY720, fingolimod) as well as proposed intervention to specify critical SL levels that tilt balances of apoptotic/active ceramide versus anti-apoptotic/inactive dihydroceramide that may offer a novel and important therapeutic approach to MS.

Topics: Apoptosis; Ceramides; Fatty Acids, Monounsaturated; Fingolimod Hydrochloride; Humans; Lysophospholipids; Metabolic Networks and Pathways; Multiple Sclerosis; Myelin Sheath; Propylene Glycols; Receptors, G-Protein-Coupled; Serine C-Palmitoyltransferase; Signal Transduction; Sphingolipids; Sphingosine

Sphingosine-1-phosphate (S1P) is a lysophospholipid signaling molecule that regulates important biological functions in both intracellular and extracellular compartments. It interacts with five G protein-coupled receptors subtypes (S1PR(1-5)) to generate multiple downstream signaling. Activation of S1PR1 has been validated to be involved in the process of immune modulation. Fingolimod (FTY720), the novel S1PR1 agonist, has been approved for the treatment of multiple sclerosis in clinical trials. The study towards discovery of selective S1PR1 agonists has become hot spot for immunological diseases. This article summarized the research progress of S1PR1 agonists, emphasizing their structure types, structure-activity relationship and direction of development.

Topics: Animals; Fingolimod Hydrochloride; Humans; Immunosuppressive Agents; Lysophospholipids; Multiple Sclerosis; Propylene Glycols; Receptors, Lysosphingolipid; Sphingosine; Structure-Activity Relationship

Over the last years, sphingosine-1-phosphate signaling function (S1P) is thought to play a key role in the development of immunological and neurological components of multiple sclerosis (MS). Modulators of the S1P-system are highly effective in MS treatment. Fingolimod, a structural analogue of endogenous sphingosine, is a first generation drug of a new class of medications known as "modulators of sphingosine-1-phosphate receptors". The inhibition of S1P receptors by fingolimod in MS reduces the recirculation of autoreactive central memory T-cells and their infiltration of the CNS where they cause a damage that clinically reveals in the decrease in the number of MS exacerbations and less severe inflammatory brain changes in MRI.

Topics: Animals; Disease Models, Animal; Fingolimod Hydrochloride; Humans; Immune System; Immunosuppressive Agents; Lysophospholipids; Multiple Sclerosis; Propylene Glycols; Receptors, Lysosphingolipid; Signal Transduction; Sphingosine

Topics: Administration, Oral; Animals; Clinical Trials, Phase I as Topic; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Fingolimod Hydrochloride; Humans; Lymphocytes; Lysophospholipids; Multiple Sclerosis; Propylene Glycols; Receptors, Lysosphingolipid; Secondary Prevention; Sphingosine; Th17 Cells

FTY720 is a recently approved first line therapy for relapsing forms of multiple sclerosis. In this context, FTY720 is a pro-drug, with its anti-multiple sclerosis, immunosuppressive effects largely elicited following its phosphorylation by sphingosine kinase 2 and subsequent modulation of G protein-coupled sphingosine 1-phosphate (S1P) receptor 1 that induces lymphopenia by altering lymphocyte trafficking. A number of other biological effects of FTY720 have, however, been described, including considerable evidence that this drug also has anti-cancer properties. These other effects of FTY720 are independent of S1P receptors, and appear facilitated by modulation of a range of other recently described protein targets by nonphosphorylated FTY720. Here, we review the direct targets of FTY720 that contribute to its anti-cancer properties. We also discuss other recently described protein effectors that, in combination with S1P receptors, appear to contribute to its immunosuppressive effects.

Topics: Antineoplastic Agents; Apoptosis; Fingolimod Hydrochloride; Humans; Immunosuppressive Agents; Lymphopenia; Lysophospholipids; Multiple Sclerosis; Neoplasms; Phosphorylation; Phosphotransferases (Alcohol Group Acceptor); Propylene Glycols; Receptors, Lysosphingolipid; Sphingosine

Multiple sclerosis is an autoimmune inflammatory disease of the central nervous system with neurodegenerative chararacteristics. The newly discovered per os administrable drug fingolimod (FTY720) has a different mechanism of action than the current disease-modifying therapies. In vivo the drug binds to four out of the five sphingosine-1-phosphate receptors after phosphorylation. Fingolimod-phosphate (FTY720-P) causes internalization and degradation of the sphingosine-1-phosphate receptors in the membrane of lymphocytes thus in contrast to sphingosine-1-phosphate it acts like a functional antagonist. In experimental autoimmune encephalomyelitis--an animal model of multiple sclerosis--fingolimod blocks the sphingosine-1-phosphate gradient controlled lymphocyte egress from the lymph nodes and therefore reduces the peripheral lymphocyte count especially the encephalitogenic Th17 subset is reduced. Modulation of the sinus lining and blood-brain-barrier constructing endothelial cells also contributes to the complex mechanism of action. Additionally due to its liphohilic nature fingolimod is able to penetrate the blood brain barrier thus, beside its peripheral effects the drug can probably modulate the cells of the central nervous system directly. Presumably it can reduce neurodegeneration caused by astrogliosis through modification of astrocyte and oligodendrocyte activity. The results of current clinical studies show a bright perspective for both, the favourable therapeutic effects and the well-tolerated side effects.

Topics: Administration, Oral; Animals; Blood-Brain Barrier; Cardiovascular System; Central Nervous System; Dendritic Cells; Encephalomyelitis, Autoimmune, Experimental; Fingolimod Hydrochloride; Humans; Immunosuppressive Agents; Lymphocyte Count; Lysophospholipids; Multiple Sclerosis; Organophosphates; Propylene Glycols; Sphingosine; Th17 Cells; Treatment Outcome

Sphingosine 1-phosphate (S1P) signaling in the treatment of multiple sclerosis (MS) has been highlighted by the efficacy of FTY720 (fingolimod), which upon phosphorylation can modulate S1P receptor activities. FTY720 has become the first oral treatment for relapsing MS that was approved by the FDA in September 2010. Phosphorylated FTY720 modulates four of the five known S1P receptors (S1P(1), S1P(3), S1P(4), and S1P(5)) at high affinity. Studies in human MS and its animal model, experimental autoimmune encephalomyelitis (EAE), have revealed that FTY720 exposure alters lymphocyte trafficking via sequestration of auto-aggressive lymphocytes within lymphoid organs, representing the current understanding of its mechanism of action. These effects primarily involve S1P(1), which is thought to attenuate inflammatory insults in the central nervous system (CNS). In addition, FTY720's actions may involve direct effects on S1P receptor-mediated signaling in CNS cells, based upon the known expression of S1P receptors in CNS cell types relevant to MS, access to the CNS through the blood-brain barrier (BBB), and in vitro studies. These data implicate lysophospholipid signaling--via S1P(1) and perhaps other lysophospholipid receptors--in therapeutic approaches to MS and potentially other diseases with immunological and/or neurological components.

Topics: Animals; Central Nervous System; Encephalomyelitis, Autoimmune, Experimental; Fingolimod Hydrochloride; Humans; Inflammation; Lymphocytes; Lysophospholipids; Multiple Sclerosis; Phosphorylation; Propylene Glycols; Receptors, Lysophospholipid; Signal Transduction; Sphingosine

Sphingosine 1-phosphate (S1P) evokes a plethora of physiological responses by stimulating members of a G protein-coupled receptor family, known as S1P receptors. Currently five different mammalian S1P receptor subtypes, S1P₁₋₅, each with a different cellular expression pattern, were identified. The S1P₁ receptor in particular has attracted major interest throughout the pharmaceutical industry following the breakthrough discovery that this S1P receptor subtype is critically involved in the regulation of lymphocyte trafficking through secondary lymphoid organs. Since then, examples of synthetic S1P₁ agonists with lymphocyte reducing and immunomodulating activity demonstrated efficacy in numerous preclinical models of autoimmune disease and transplantation. Notably FTY720 (fingolimod), a pro-drug that is phosphorylated in vivo and converted into a non-selective S1P₁,₃,₄,₅ receptor agonist, has been widely used to increase the understanding of S1P₁ receptor biology. Results from recently completed phase III clinical trials using FTY720 paved the way for this non-selective S1P₁ receptor agonist to become the first oral therapy in multiple sclerosis, with potential expansion into many other autoimmune diseases. This review briefly outlines the field of S1P₁ receptor biology and summarizes recent approaches in medicinal chemistry to discover potent and selective S1P₁ receptor agonists. In particular, the complexity of discovering a molecule akin to FTY720 but with an improved side-effect profile will be discussed.

Topics: Animals; Fingolimod Hydrochloride; Humans; Lysophospholipids; Multiple Sclerosis; Propylene Glycols; Receptors, Lysosphingolipid; Sphingosine; Structure-Activity Relationship

Viral infections may have an important role in the precipitation or relapse of multiple sclerosis (MS) and its treatment. This review describes the normal immune response to viral infection, the possible associations between viral infections and MS therapy, and the impact of sphingosine 1-phosphate (S1P) receptor (S1PR) modulation with fingolimod (FTY720) on the immune responses to viral infection. The physiologic immune response to viral infection involves lymphocyte activation and control of the circulation of subsets of lymphocytes with different functions between the lymph nodes, vascular system, and tissues, under the control of the S1P/S1PR signaling mechanism. In MS, it has been postulated that viral infections may play a role in triggering MS relapses, with virus-specific T cells being responsible for the demyelinating lesions within the CNS. Fingolimod-an S1PR modulator approved for the treatment of relapsing MS in some countries-is thought to act by downmodulating lymphatic S1P subtype 1 receptors. This retains naïve T cells and central memory T cells, but not effector memory T cells, within the lymph nodes and prevents their circulation to the CNS. Evidence from infection models supports that the selective effects of fingolimod on T cell subsets allows key immune responses to be preserved during therapy. However, in patients, long-term observation is important as both the risk of cancer and infection is potentially increased by the use of any immunomodulatory agent.

Topics: Animals; Fingolimod Hydrochloride; Gene Expression Regulation; Humans; Immune System; Immunosuppressive Agents; Lymphocytes; Lysophospholipids; Multiple Sclerosis; Propylene Glycols; Receptors, Lysosphingolipid; Signal Transduction; Sphingosine; Virus Diseases

The oral sphingosine 1-phosphate (S1P) receptor (S1PR) modulator fingolimod has been shown to be effective in the treatment of patients with relapsing multiple sclerosis (MS). The drug binds with high affinity to 4 of the 5 G-protein-coupled S1P receptors (S1P(1-5)). After binding, the receptors are internalized, degraded, and thus functionally antagonized by fingolimod. Under physiologic conditions, S1P(1) mediates the egress of lymphocytes from secondary lymphoid organs to the peripheral circulation. Functional antagonism of S1P(1) by fingolimod results in a reduction in peripheral lymphocyte counts by inhibiting egress of lymphocytes, including potentially encephalitogenic T cells and their naïve progenitors that would otherwise be present within the circulation. Despite the fingolimod-mediated reduction of lymphocyte counts, fingolimod-treated patients with MS have been shown to have few infections and related complications and were able to mount antigen-specific immune responses in vaccination studies.

Topics: Fingolimod Hydrochloride; Humans; Immune System; Immunosuppressive Agents; Lymphocytes; Lysophospholipids; Multiple Sclerosis; Propylene Glycols; Receptors, Lysosphingolipid; Sphingosine

Until recently, all approved multiple sclerosis (MS) disease treatments were administered parenterally. Oral fingolimod was approved in September 2010 by the US Food and Drug Administration to reduce relapses and disability progression in relapsing forms of MS. In the clinical trials that led to approval, fingolimod reduced not only acute relapses and magnetic resonance imaging lesion activity but also disability progression and brain volume loss, suggesting preservation of tissue. Fingolimod's mechanism of action in MS is not known with certainty. Its active form, fingolimod-phosphate (fingolimod-P), is a sphingosine 1-phosphate receptor (S1PR) modulator that inhibits egress of lymphocytes from lymph nodes and their recirculation, potentially reducing trafficking of pathogenic cells into the central nervous system (CNS). Fingolimod also readily penetrates the CNS, and fingolimod-P formed in situ may have direct effects on neural cells. Fingolimod potently inhibits the MS animal model, experimental autoimmune encephalomyelitis, but is ineffective in mice with selective deficiency of the S1P₁ S1PR subtype on astrocytes despite normal expression in the immune compartment. These findings suggest that S1PR modulation by fingolimod in both the immune system and CNS, producing a combination of beneficial anti-inflammatory and possibly neuroprotective/reparative effects, may contribute to its efficacy in MS. In clinical trials, fingolimod was generally safe and well tolerated. Its interaction with S1PRs in a variety of tissues largely accounts for the reported adverse effects, which were seen more frequently with doses 2.5 to 10x the approved 0.5 mg dose. Fingolimod's unique mechanism of action distinguishes it from all other currently approved MS therapies.

Topics: Animals; Central Nervous System; Chemical and Drug Induced Liver Injury; Clinical Trials as Topic; Disease Models, Animal; Fingolimod Hydrochloride; Heart Diseases; Humans; Immunosuppressive Agents; Infections; Liver Diseases; Lymphocytes; Lysophospholipids; Multiple Sclerosis; Propylene Glycols; Receptors, Lysosphingolipid; Respiration Disorders; Sphingosine

Multiple sclerosis is the most frequent chronic inflammatory, demyelinating and neurodegenerative disease in young adults, but has no definitive pharmacological treatment. It is a heterogeneous disease from the immunological, neuropathological and clinical point of view, as well as in terms of its response to different therapies. Over the last two decades, pharmacology has focused on developing drugs that are capable of modifying the course of this disease, with the aim of reducing the frequency of the outbreaks and the speed at which the disability produced by the disease progresses. Nevertheless, today, there are no drugs that are capable of offering a curative effect that can fully stabilise the disease, and neuroprotective and neuroreparative strategies are still in their early stages. In this work we carry out a critical review of the different pathogenic paths involved in multiple sclerosis and we discuss the different pharmacological approaches that have been followed, based on the clinical trials that are currently being conducted. In the near future it is to be expected that, first, we will manage to stabilise the disease completely and, later, recover some of the functions altered by this disease. Research is being conducted at such a rate that we have to be optimistic and think that soon we will be able to improve the situation of those who suffer from the disease.

Topics: Adenosine Deaminase; Antigen-Presenting Cells; Antigens, CD; Cell Adhesion Molecules; Dihydroorotate Dehydrogenase; Humans; Lysophospholipids; Matrix Metalloproteinases; Multiple Sclerosis; Myelin Basic Protein; NF-kappa B; Oxidoreductases Acting on CH-CH Group Donors; Sphingosine; Transforming Growth Factor beta

Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid that mediates a wide variety of biological effects in different cells and tissues. This review discusses the effects of S1P signaling in oligodendrocytes, the myelin making cells of the central nervous system (CNS). Results from different laboratories have uncovered direct actions of S1P at different maturational stages along the oligodendroglial lineage. There is also evidence for the existence in oligodendrocytes of interactions between S1P and signaling by factors which, like neurotrophin-3 (NT-3) and platelet-derived growth factor (PDGF), have profound effects on oligodendrocyte development and myelination. Moreover, S1P signaling in oligodendrocytes may not only play an important role during normal CNS development but also offer new therapeutic avenues to stimulate remyelination in demyelinating diseases like multiple sclerosis.

Topics: Animals; Cell Lineage; Humans; Lysophospholipids; Multiple Sclerosis; Oligodendroglia; Receptor Cross-Talk; Signal Transduction; Sphingosine

Multiple sclerosis (MS) is a chronic central nervous system disease in which autoimmune mechanisms are operative. Although it appears that the prognosis of MS has been significantly improved after interferon-beta and glatiramer acetate were introduced in clinic, many patients are still refractory to available medications, and the necessity to develop new treatment options is obvious. Current trend in the drug discovery is to find or make a drug whose molecular target is clearly identified. This is also the case for the development of drugs for MS. Here I review current status in the development of so-called "molecular target drugs" for MS. In general, effects of such drugs well fit to the expected mechanism of action. Although concerns about opportunistic infections including JC virus-mediated progressive multi-focal leukoencephalopathy (PML) have not been dissolved, better clinical and laboratory monitoring of the immune system of the patients may help minimize potential side effects of these drugs.

Topics: Abatacept; Animals; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Autoimmunity; Clinical Trials as Topic; Daclizumab; Drug Discovery; Fingolimod Hydrochloride; Humans; Immunoconjugates; Immunoglobulin G; Integrin alpha4beta1; JC Virus; Leukoencephalopathy, Progressive Multifocal; Ligands; Lysophospholipids; Multiple Sclerosis; Natalizumab; Opportunistic Infections; Propylene Glycols; Receptors, Antigen, T-Cell; Sphingosine; Ustekinumab

FTY720 (fingolimod) is a first-in-class sphingosine 1-phosphate (S1P) receptor modulator that was highly effective in Phase II clinical trials for Multiple Sclerosis (MS). FTY720 is phosphorylated in vivo by sphingosine kinase-2 to form the active moiety FTY720-phosphate that binds to four of the five G protein-coupled S1P receptor subtypes. Studies using conditional S1P1 receptor-deficient and sphingosine kinase-deficient mice showed that the egress of lymphocytes from lymph nodes requires signalling of lymphocytic S1P1 receptors by the endogenous ligand S1P. The S1P mimetic FTY720-phosphate causes internalization and degradation of cell membrane-expressed S1P1, thereby antagonizing S1P action at the receptor. In models of human MS and demyelinating polyneuropathies, functional antagonism of lymphocytic S1P1 slows S1P-driven egress of lymphocytes from lymph nodes, thereby reducing the numbers of autoaggressive TH17 cells that recirculate via lymph and blood to the central nervous system and the sciatic/ischiatic nerves. Based on its lipophilic nature, FTY720 crosses the blood-brain barrier, and ongoing experiments suggest that the drug also down-modulates S1P1 in neural cells/astrocytes to reduce astrogliosis, a phenomenon associated with neurodegeneration in MS. This may help restore gap-junctional communication of astrocytes with neurons and cells of the blood-brain barrier. Additional effects may result from (down-) modulation of S1P3 in astrocytes and of S1P1 and S1P5 in oligodendrocytes. In conclusion, FTY720 may act through immune-based and central mechanisms to reduce inflammation and support structural restoration of the central nervous system parenchyma. Beyond the autoimmune indications, very recent studies suggest that short-term, low-dose administration of FTY720 could help treat chronic (viral) infections. Differential effects of the drug on the trafficking of naïve, central memory and effector memory T cell subsets are discussed.

Topics: Animals; Astrocytes; Brain; Encephalomyelitis, Autoimmune, Experimental; Fingolimod Hydrochloride; Gap Junctions; Humans; Immune System; Inflammation; Lymph Nodes; Lysophospholipids; Multiple Sclerosis; Phosphorylation; Phosphotransferases (Alcohol Group Acceptor); Propylene Glycols; Receptors, Lysosphingolipid; Sphingosine; T-Lymphocytes

Sphingosine 1-phosphate (S1P) is a bioactive sphingolipid metabolite involved in many critical cellular processes including proliferation, survival, and migration, as well as angiogenesis and allergic responses. S1P levels inside cells are tightly regulated by the balance between its synthesis by sphingosine kinases and degradation. S1P is interconvertible with ceramide, which is a critical mediator of apoptosis. It has been postulated that the ratio between S1P and ceramide determines cell fate. Activation of sphingosine kinase by a variety of agonists increases intracellular S1P, which in turn can function intracellularly as a second messenger or be secreted out of the cell and act extracellularly by binding to and signaling through S1P receptors in autocrine and/or paracrine manners. Recent studies suggest that this "inside-out" signaling by S1P may play a role in many human diseases, including cancer, atherosclerosis, inflammation, and autoimmune disorders such as multiple sclerosis. In this review we summarize metabolism of S1P, mechanisms of sphingosine kinase activation, and S1P receptors and their downstream signaling pathways and examine relationships to multiple disease processes. In particular, we describe recent preclinical and clinical trials of therapies targeting S1P signaling, including 2-amino-2-propane-1,3-diol hydrochloride (FTY720, fingolimod), S1P receptor agonists, sphingosine kinase inhibitors, and anti-S1P monoclonal antibody.

Topics: Animals; Antibodies, Monoclonal; Antineoplastic Agents; Apoptosis; Enzyme Activation; Fingolimod Hydrochloride; Humans; Hypersensitivity; Immunosuppressive Agents; Lysophospholipids; Multiple Sclerosis; Neoplasms; Phosphotransferases (Alcohol Group Acceptor); Propylene Glycols; Receptors, Lysosphingolipid; Signal Transduction; Sphingosine; Sulfhydryl Compounds

FTY720 (fingolimod; 2-amino-2[2-(4-octylphenyl)ethyl]-1,3-propanediol, Novartis) is the prototype of a new generation of immunomodulators. The drug is the result of extensive chemical derivatisation based on the natural product myriocin, isolated from the ascomycete Isaria sinclairii. FTY720 bears structural similarity to sphingosine, a naturally occurring sphingolipid. As with sphingosine, FTY720 is effectively phosphorylated by sphingosine kinases in vivo and the phosphorylated drug targets G-protein-coupled receptors for sphingosine-1-phosphate (S1P). Gene deletion and reverse pharmacology studies have shown that FTY720 acts at S1P1 receptors on lymphocytes and the endothelium, thereby inhibiting the egress of T- and B cells from secondary lymphoid organs into the blood and their recirculation to inflamed tissues. Animal studies suggest that this novel mechanism translates into effective treatments for several autoimmune diseases and a recently completed Phase II clinical trial highlighted FTY720 as a potential therapy for relapsing-remitting multiple sclerosis.

Topics: Animals; Central Nervous System; Clinical Trials as Topic; Encephalomyelitis, Autoimmune, Experimental; Endothelium, Lymphatic; Fingolimod Hydrochloride; Humans; Immunologic Factors; Lymphocytes; Lysophospholipids; Multiple Sclerosis; Propylene Glycols; Receptors, Lysosphingolipid; Sphingolipids; Sphingosine

Resistance training (RT) has been shown to elicit neuroprotective effects in persons with multiple sclerosis (pwMS). Brain-derived neurotrophic factor (BDNF) and Sphingosine-1-phosphat (S1P) have been put forward as potent mediators of the neuroprotective effects induced by RT. However, while increases have been shown in acute and chronic circulating BDNF levels in pwMS following aerobic exercise alone or in combination with other exercise regimes, no studies have examined this in response to RT. As a novel 'proof-of-concept' approach, we therefore examined the effects of 24 weeks of RT on acute and chronic circulating BDNF and S1P levels in the same pwMS whom our group had previously observed RT-induced neuroprotective effects in (i.e. increased cortical thickness and preservation of whole brain volume). A total of n = 30 relapsing-remitting pwMS were randomized into a training group (TG: 24 weeks of progressive high intensity resistance training, 2 sessions per week; n = 16, age 44[40:51] years, EDSS score 3.0[2.0:3.5] (median[IQR]) or a control group (CG: 24 weeks of habitual lifestyle; n = 14, age 45[37:47] years, EDSS score 3.0[2.5:3.5]). Plasma levels of BDNF and S1P were assessed by ELISA kits before and after the 24-week intervention period. No within- or between group changes were observed in acute or chronic circulating levels of BDNF. A substantial proportion of the participants had S1P levels below the detection limit, yet no within- or between changes were observed in chronic S1P plasma levels in the remaining samples. Thus, the present findings do not support that circulating plasma BDNF or S1P levels are the main mediators of the neuroprotective effects previously reported in the same group of pwMS.

Topics: Adult; Brain-Derived Neurotrophic Factor; Female; Humans; Lysophospholipids; Male; Middle Aged; Multiple Sclerosis; Neuroprotection; Resistance Training; Sphingosine; Treatment Outcome

Multiple sclerosis (MS) is an inflammatory-demyelinating disease of the central nervous system (CNS) mediated by aberrant auto-reactive immune responses. The current immune-modulatory therapies are unable to protect and repair immune-mediated neural tissue damage. One of the therapeutic targets in MS is the sphingosine-1-phosphate (S1P) pathway which signals via sphingosine-1-phosphate receptors 1-5 (S1P

Topics: Animals; beta-Arrestins; Central Nervous System; Cuprizone; Mice; Mice, Inbred C57BL; Multiple Sclerosis; Oligodendroglia; Receptors, Lysosphingolipid; Remyelination; Sphingosine-1-Phosphate Receptors

Ozanimod is approved in multiple countries for the treatment of adults with either relapsing multiple sclerosis or moderately to severely active ulcerative colitis. Ozanimod is metabolized in humans to form seven active plasma metabolites, including two major active metabolites CC112273 and CC1084037, and an inactive metabolite. Here, the binding and activity of ozanimod and its metabolites across human sphingosine 1-phosphate receptors were determined. Binding affinity was assessed in Chinese hamster ovary cell membranes expressing recombinant human sphingosine 1-phosphate receptors 1 and 5 via competitive radioligand binding using tritium-labeled ozanimod; selectivity via functional potency assessment was performed using [

Topics: Adult; Animals; CHO Cells; Colitis, Ulcerative; Cricetinae; Cricetulus; Humans; Indans; Multiple Sclerosis; Oxadiazoles; Sphingosine; Sphingosine-1-Phosphate Receptors

The SARS-CoV-2 Omicron variant appears to cause milder infections, however, its capacity for immune evasion and high transmissibility despite vaccination remains a concern, particularly in immunosuppressed patients. Herein, we investigate the incidence and risk factors for COVID-19 infection in vaccinated adult patients with Multiple Sclerosis (MS), Aquaporin-4-antibody Neuromyelitis Optica Spectrum Disorder (AQP4-Ab NMOSD), and Myelin Oligodendrocyte Glycoprotein-antibody associated disease (MOGAD) during the Omicron subvariant BA.1/2 wave in Singapore.. This was a prospective observational study conducted at the National Neuroscience Institute, Singapore. Only patients who had at least two doses of mRNA vaccines were included. Data on demographics, disease characteristics, COVID-19 infections and vaccinations, and immunotherapies were collected. SARS-CoV-2 neutralising antibodies were measured at various time points after vaccination.. Two hundred and one patients were included; 47 had COVID-19 infection during the study period. Multivariable logistic regression revealed that receipt of a third SARS-CoV-2 mRNA vaccination (V3) was protective against COVID-19 infection. No particular immunotherapy group increased the risk of infection, however, Cox proportional-hazards regression showed that patients on anti-CD20s and sphingosine-1-phosphate modulators (S1PRMs) had a shorter time to infection after V3, compared to those on other immunotherapies or not on immunotherapy.. The Omicron subvariant BA.1/2 is highly infectious in patients with central nervous system inflammatory diseases; three doses of mRNA vaccination improved protection. However, treatment with anti-CD20s and S1PRMs predisposed patients to earlier infection. Future studies are required to determine the protective efficacy of newer bivalent vaccines that target the Omicron (sub)variant, especially in immunocompromised patients.

Topics: Antibodies, Viral; COVID-19; Humans; Multiple Sclerosis; Myelin-Oligodendrocyte Glycoprotein; Neuromyelitis Optica; SARS-CoV-2; Singapore; Vaccination

VLCFAs (very-long-chain fatty acids) are the most abundant fatty acids in myelin. Hence, during demyelination or aging, glia are exposed to higher levels of VLCFA than normal. We report that glia convert these VLCFA into sphingosine-1-phosphate (S1P) via a glial-specific S1P pathway. Excess S1P causes neuroinflammation, NF-κB activation, and macrophage infiltration into the CNS. Suppressing the function of S1P in fly glia or neurons, or administration of Fingolimod, an S1P receptor antagonist, strongly attenuates the phenotypes caused by excess VLCFAs. In contrast, elevating the VLCFA levels in glia and immune cells exacerbates these phenotypes. Elevated VLCFA and S1P are also toxic in vertebrates based on a mouse model of multiple sclerosis (MS), experimental autoimmune encephalomyelitis (EAE). Indeed, reducing VLCFA with bezafibrate ameliorates the phenotypes. Moreover, simultaneous use of bezafibrate and fingolimod synergizes to improve EAE, suggesting that lowering VLCFA and S1P is a treatment avenue for MS.

Topics: Animals; Bezafibrate; Encephalomyelitis, Autoimmune, Experimental; Fatty Acids; Fingolimod Hydrochloride; Immunosuppressive Agents; Mice; Multiple Sclerosis; Neuroglia; Neuroinflammatory Diseases; Propylene Glycols

Lysophospholipids are bioactive lipids and can signal through G-protein-coupled receptors (GPCRs). The best studied lysophospholipids are lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P). The mechanisms of lysophospholipid recognition by an active GPCR, and the activations of lysophospholipid GPCR-G-protein complexes remain unclear. Here we report single-particle cryo-EM structures of human S1P receptor 1 (S1P

Topics: Animals; Azetidines; Benzyl Compounds; Cryoelectron Microscopy; GTP-Binding Protein alpha Subunits, Gi-Go; Humans; Lysophospholipids; Molecular Conformation; Molecular Docking Simulation; Multiple Sclerosis; Receptors, Lysophosphatidic Acid; Recombinant Proteins; Sf9 Cells; Single Molecule Imaging; Sphingosine; Sphingosine-1-Phosphate Receptors; Spodoptera

Sphingosine 1-phosphate (S1P) is an extensively studied signaling molecule that contributes to cell proliferation, survival, migration and other functions through binding to specific S1P receptors. The cycle of S1P

Topics: Animals; CHO Cells; Cricetulus; Fingolimod Hydrochloride; Humans; Lymphocyte Count; Lysophospholipids; Mice; Mice, Inbred C57BL; Multiple Sclerosis; Phosphotransferases (Alcohol Group Acceptor); Receptors, Lysosphingolipid; Signal Transduction; Sphingosine; T-Lymphocytes

Systemic suppression of adaptive immune responses is a major way in which UV radiation contributes to skin cancer development. Immune suppression is also likely to explain how UV protects from some autoimmune diseases, such as multiple sclerosis. However, the mechanisms underlying UV-mediated systemic immune suppression are not well understood. Exposure of C57BL/6 mice to doses of UV known to suppress systemic autoimmunity led to the accumulation of cells within the skin-draining lymph nodes and away from non-skin-draining lymph nodes. Transfer of CD45.1

Topics: Animals; Blood Circulation; Cells, Cultured; Humans; Immunologic Memory; Immunosuppression Therapy; Lymph Nodes; Lymphocyte Activation; Lysophospholipids; Mice; Mice, Inbred C57BL; Multiple Sclerosis; Phosphotransferases (Alcohol Group Acceptor); Signal Transduction; Skin; Sphingosine; Sphingosine-1-Phosphate Receptors; Ultraviolet Rays; Ultraviolet Therapy

The Siponimod (Mayzent) is a newly developed drug, similar to Fingolimod (FTY720) but with fewer side effects, approved by the Food and Drug Administration for the treatment of multiple sclerosis (MS). The therapeutic effect of siponimod and FTY720 in MS relies on their inhibitory effect on the sphingosine 1-phosphate (S1P) signaling. These drugs bind to the S1P receptors and block the CCL2 chemokine pathway that is responsible for the exit of the immune cells from the lymphoid organs, and circulation, thus preventing immune cell-dependent injury to the nervous system. We recently found that FTY720 beside its effect on the S1P pathway also blocks the RhoA pathway, which is involved in the actin cytoskeleton-related function of macrophages, such as expression/recycling of fractalkine (CX3CL1) receptors (CX3CR1), which direct macrophages to the transplanted organs during the development of the long-term (chronic) rejection. Here we tested the effects of siponimod on the RhoA pathway and the expression of the S1P1 and CX3CR1 receptors in mouse RAW 264.7 macrophages. We found that siponimod downregulates the expression of RhoA protein and decreases the cell surface expression of S1P1 and CX3CR1 receptors. This newly discovered crosstalk between S1P and RhoA/CX3CR1 pathways may help in the development of novel anti-chronic rejection therapies in clinical transplantation.

Topics: Actin Cytoskeleton; Animals; Azetidines; Benzyl Compounds; Cell Membrane; Chemokine CCL2; Down-Regulation; Fingolimod Hydrochloride; Graft Rejection; Humans; Lysophospholipids; Macrophages; Membrane Proteins; Mice; Multiple Sclerosis; Organ Transplantation; Phosphoric Monoester Hydrolases; RAW 264.7 Cells; Receptors, Interleukin-8A; rhoA GTP-Binding Protein; Signal Transduction; Sphingosine; United States; United States Food and Drug Administration

Multiple sclerosis (MS) is a chronic, inflammatory, autoimmune disease of the central nervous system (CNS) which is associated with lower life expectancy and disability. The experimental antigen-induced encephalomyelitis (EAE) in mice is a useful animal model of MS, which allows exploring the etiopathogenetic mechanisms and testing novel potential therapeutic drugs. A new therapeutic paradigm for the treatment of MS was introduced in 2010 through the sphingosine 1-phosphate (S1P) analogue fingolimod (FTY720, Gilenya

Topics: Animals; Central Nervous System; CHO Cells; Cricetulus; Disease Models, Animal; Encephalomyelitis; Encephalomyelitis, Autoimmune, Experimental; Fingolimod Hydrochloride; Immunosuppressive Agents; Ligands; Lymphopenia; Lysophospholipids; Mice; Morpholinos; Multiple Sclerosis; Receptors, Lysosphingolipid; Sphingosine; Sphingosine-1-Phosphate Receptors; Spinal Cord; T-Lymphocytes

Fingolimod is one of the few oral drugs available for the treatment of multiple sclerosis (MS), a chronic, inflammatory, demyelinating and neurodegenerative disease. The mechanism of action proposed for this drug is based in the phosphorylation of the molecule to produce its active metabolite fingolimod phosphate (FP) which, in turns, through its interaction with S1P receptors, triggers the functional sequestration of T lymphocytes in lymphoid nodes. On the other hand, part if not most of the damage produced in MS and other neurological disorders seem to be mediated by reactive oxygen species (ROS), and mitochondria is one of the main sources of ROS. In the present work, we have evaluated the anti-oxidant profile of FP in a model of mitochondrial oxidative damage induced by menadione (Vitk3) on neuronal cultures. We provide evidence that incubation of neuronal cells with FP alleviates the Vitk3-induced toxicity, due to a decrease in mitochondrial ROS production. It also decreases regulated cell death triggered by imbalance in oxidative stress (restore values of advanced oxidation protein products and total thiol levels). Also restores mitochondrial function (cytochrome c oxidase activity, mitochondrial membrane potential and oxygen consumption rate) and morphology. Furthermore, increases the expression and activity of protective factors (increases Nrf2, HO1 and Trx2 expression and GST and NQO1 activity), being some of these effects modulated by its interaction with the S1P receptor. FP seems to increase mitochondrial stability and restore mitochondrial dynamics under conditions of oxidative stress, making this drug a potential candidate for the treatment of neurodegenerative diseases other than MS.

Topics: Animals; Antioxidants; Cell Death; Cell Line; Dopaminergic Neurons; Fingolimod Hydrochloride; Humans; Lysophospholipids; Membrane Potential, Mitochondrial; Mice; Mitochondria; Molecular Mimicry; Multiple Sclerosis; Neuroprotection; Oxidative Stress; Oxygen Consumption; Phosphates; Reactive Oxygen Species; Sphingosine; Sphingosine-1-Phosphate Receptors; Vitamin K 3

Fingolimod (FTY) is known to have multiple effects on the immune system and the central nervous system (CNS) in patients with multiple sclerosis (MS). In this study, we evaluated the immunological and neurobiological effects of FTY in MS. Blood and cerebrospinal fluid (CSF) samples were collected from 15 MS patients before first FTY administration and after 4 months of FTY therapy. Immunophenotyping and evaluation of sphingosine-1-phosphate (S1P), neurofilament light chain (NFL), S-100 and neuron-specific enolase (NSE) levels were conducted. After 4 months of FTY therapy, absolute cell count in CSF was decreased from 6.33 to 2.43 MPt/l, accompanied by decreases of CD3+ (2.22 to 0.65 MPt/l) and of CD4+ counts (1.60 to 0.39 MPt/l). In blood, CD3+ (1.05 to 0.09 GPt/l), CD4+ (0.80 to 0.02 GPt/l), CD8+ (0.23 to 0.04 GPt/l) and CD19+ (0.21 to 0.01GPt/l) cell counts were as well reduced. CD14+ cell count remained stable over the same period (0.24 to 0.26GPt/l). NFL and S1P levels in CSF and blood were reduced over time (NFL: CSF 1759 to 1359 pg/l, blood 8.42 to 7.36 pg/l; S1P: CSF 2.12 to 0.71 nmol/l, blood 392.1 to 312.9 nmol/l). Strong correlations between CSF and blood NFL levels were observed. Neuronal damage markers such as S-100 (1.86 to 1.69 μg/l) and NSE (9.53 to 8.67 μg/l) were reduced to a lesser degree than other markers. FTY exerted significant effects on immunological and neurobiological markers in the central and peripheral compartment. Decreases in levels of neuroinflammatory and neurodegenerative markers were already evident after 4 months of treatment. Four-month serum NFL level appears to be a useful marker for FTY efficacy that correlates well with changes in the CNS compartment. KEY MESSAGES: FTY has important immunological effects in both central and peripheral compartments. Cellular effects of FTY effects are more pronounced in the blood than in the CSF. FTY reduces S1P and NFL levels in CSF and serum. Serum NFL appears to be a useful marker for FTY therapy.

Topics: Adult; Biomarkers; Central Nervous System; Cerebrospinal Fluid; Female; Fingolimod Hydrochloride; Humans; Longitudinal Studies; Lysophospholipids; Male; Middle Aged; Multiple Sclerosis; Peripheral Nervous System; Sphingosine

Multiple Sclerosis (MS) is a chronic autoimmune disorder affecting the Central Nervous System (CNS) through inflammation, demyelination and neurodegeneration. Sphingosine-1-phosphate receptor (S1PR1) modulators have been approved for the management of MS. Phosphorylated fingolimod mimics endogenous sphingosine-1-phosphate (S1P), a bioactive lipid that regulates remyelination and cell injury. Amiselimod was developed as a successor of fingolimod, with more specificity for S1PR1, and showed promising results until phase 2 clinical trials. This study utilized the fingolimod and amiselimod scaffolds, together with their critical binding interactions for the S1PR1 Ligand Binding Pocket, as templates for the

Topics: Algorithms; Animals; Crystallography, X-Ray; Drug Design; Fingolimod Hydrochloride; Humans; Immunologic Factors; Lysophospholipids; Molecular Structure; Multiple Sclerosis; Protein Structure, Secondary; Receptors, Lysosphingolipid; Sphingosine

Berberine (BBR) has shown neuroprotective properties. The present study aims to investigate the effects of BBR on experimental autoimmune encephalomyelitis (EAE), a murine model of multiple sclerosis (MS), and SphK1/S1P signaling, which plays a key role in MS. EAE was induced in mice, followed by treatment with BBR at 50, 100, or 300 mg/kg/d. Neurophysiological function was evaluated daily; inflammation, cell infiltration, and the severity of demyelination were also examined. The SphK1, SphK2, and S1P levels in the animals and primary astrocyte culture were measured. We found that treatment with BBR reduced the loss of neurophysiological function and the degree of demyelination. Moreover, BBR was associated with a decrease in SphK1 and S1P levels both in the animals and in culture. These results indicated that BBR suppresses demyelination and loss of neurophysiological function by inhibiting the SphK1/S1P signaling pathway. The use of BBR as a treatment of MS warrant further exploration.

Topics: Animals; Berberine; Encephalomyelitis, Autoimmune, Experimental; Female; Lysophospholipids; Mice; Mice, Inbred C57BL; Multiple Sclerosis; Neuroprotective Agents; Phosphotransferases (Alcohol Group Acceptor); Signal Transduction; Sphingosine; Spinal Cord

Fingolimod, a sphingosine-1-phosphate (S1P) receptor modulator, is an oral drug approved for the treatment of active relapsing-remitting multiple sclerosis (RRMS). It selectively inhibits the egress of lymphocytes from lymph nodes. We studied the changes in the transcriptome of peripheral blood CD8

Topics: Adult; CD8-Positive T-Lymphocytes; Cytokines; Cytotoxicity, Immunologic; Female; Fingolimod Hydrochloride; Humans; Lysophospholipids; Male; Middle Aged; Multiple Sclerosis; Phenotype; Sphingosine

It is accepted that sphingolipids (SL) are not only structural lipids in cellular membranes, but also key regulators of different cell process. Sphingosine-1-phosphate (S1P) is a member of this family involved, inter alia, in cell migration, angiogenesis and cell proliferation processes, being able to play different intracellular and extracellular roles. When S1P is transported out of the cell, it binds S1P specific G protein-coupled receptors, which are mainly involved in the regulation of the immune, vascular and nervous systems. These effects account for the vast diversity of functions that arise from the activation of S1P receptors. Deregulation of S1P levels is correlated with several pathologies, such as autoimmune disorders and cancer. Consequently, the correct modulation of these receptors represents a valuable approach for the development of new therapeutic strategies. Along this line, the non-selective S1P receptor agonist fingolimod (FTY720) has been commercialized recently for the treatment of multiple sclerosis and several related S1P receptor modulators are ongoing clinical trials. However, despite the progress in this field, the biological functions of S1P receptors are not still well elucidated. For this reason, several studies are being developed in order to better understand the functions of these receptors, making use of new selective S1P receptor agonists and antagonists as pharmacological tools.

Topics: Fingolimod Hydrochloride; Humans; Immune System; Immunosuppressive Agents; Lysophospholipids; Multiple Sclerosis; Nervous System; Receptors, Lysosphingolipid; Sphingolipids; Sphingosine

Multiple sclerosis patients are treated with fingolimod (FTY720), a prodrug that acts as an immune modulator. FTY720 is first phosphorylated to FTY720-P and then internalizes sphingosine-1-phosphate receptors, preventing lymphocyte sequestration. IL-33 is released from necrotic endothelial cells and contributes to MS severity by coactivating T cells. Herein we analyzed the influence of FTY720, FTY720-P, and S1P on IL-33 induced formation of IL-2 and IFN-γ, by using IL-33 receptor overexpressing EL4 cells, primary CD8(+) T cells, and splenocytes. EL4-ST2 cells released IL-2 after IL-33 stimulation that was inhibited dose-dependently by FTY720-P but not FTY720. In this system, S1P increased IL-2, and accordingly, inhibition of S1P producing sphingosine kinases diminished IL-2 release. In primary CD8(+) T cells and splenocytes IL-33/IL-12 stimulation induced IFN-γ, which was prevented by FTY720 but not FTY720-P, independently from intracellular phosphorylation. The inhibition of IFN-γ by nonphosphorylated FTY720 was mediated via the SET/protein phosphatase 2A (PP2A) pathway, since a SET peptide antagonist also prevented IFN-γ formation and the inhibition of IFN-γ by FTY720 was reversible by a PP2A inhibitor. While our findings directly improve the understanding of FTY720 therapy in MS, they could also contribute to side effects of FTY720 treatment, like progressive multifocal leukoencephalopathy, caused by an insufficient immune response to a viral infection.

Topics: Animals; CD8-Positive T-Lymphocytes; Cell Line, Tumor; DNA-Binding Proteins; Female; Fingolimod Hydrochloride; Histone Chaperones; Interferon-gamma; Interleukin-2; Interleukin-33; Lysophospholipids; Mice; Mice, Inbred C57BL; Multiple Sclerosis; Oncogene Proteins; Organophosphates; Phosphorylation; Phosphotransferases (Alcohol Group Acceptor); Protein Phosphatase 2; Sphingosine; Spleen

FTY720 (Fingolimod; Gilenya®) is an immune-modulatory prodrug which, after intracellular phosphorylation by sphingosine kinase 2 (SphK2) and export, mimics effects of the endogenous lipid mediator sphingosine-1-phosphate. Fingolimod has been introduced to treat relapsing-remitting multiple sclerosis. However, little has been published about the immune cell membrane penetration and subcellular distribution of FTY720 and FTY720-P. Thus, we applied a newly established LC-MS/MS method to analyze the subcellular distribution of FTY720 and FTY720-P in subcellular compartments of spleen cells of wild type, SphK1- and SphK2-deficient mice. These studies demonstrated that, when normalized to the original cell volume and calculated on molar basis, FTY720 and FTY720-P dramatically accumulated several hundredfold within immune cells reaching micromolar concentrations. The amount and distribution of FTY720 was differentially affected by SphK1- and SphK2-deficiency. On the background of recently described relevant intracellular FTY720 effects in the nanomolar range and the prolonged application in multiple sclerosis, this data showing a substantial intracellular accumulation of FTY720, has to be considered for benefit/risk ratio estimates.

Topics: Animals; Cells, Cultured; Female; Fingolimod Hydrochloride; Lysophospholipids; Mice; Mice, Inbred C57BL; Multiple Sclerosis; Organophosphates; Phosphorylation; Phosphotransferases (Alcohol Group Acceptor); Sphingosine; Spleen; Tandem Mass Spectrometry

The characterization of molecular pathways that modulate blood-brain barrier (BBB) function and integrity has been fueled by a growing body of literature implicating BBB dysfunction in a wide range of neurologic diseases. Sphingosine 1-phosphate (S1P) is a pleiotropic signaling molecule that has been effectively targeted by the immunomodulatory S1P1 functional antagonist fingolimod in the treatment of multiple sclerosis (MS). Investigation into the pathways modulated by S1P has revealed its important role in regulating BBB integrity via signaling through receptor isoforms on astrocytes and endothelial cells (ECs). Current evidence supports a significant role for S1P signaling as a key determinant of BBB permeability and hence as a potential pathogenic player or therapeutic target in diseases characterized by BBB dysfunction.

Topics: Animals; Astrocytes; Blood-Brain Barrier; Capillary Permeability; Endothelial Cells; Fingolimod Hydrochloride; Humans; Immunologic Factors; Lysophospholipids; Multiple Sclerosis; Receptors, Lysosphingolipid; Signal Transduction; Sphingosine

The ability of the Blood Brain Barrier (BBB) to maintain proper barrier functions, keeping an optimal environment for central nervous system (CNS) activity and regulating leukocytes' access, can be affected in CNS diseases. Endothelial cells and astrocytes are the principal BBB cellular constituents and their interaction is essential to maintain its function. Both endothelial cells and astrocytes express the receptors for the bioactive sphingolipid S1P. Fingolimod, an immune modulatory drug whose structure is similar to S1P, has been approved for treatment in multiple sclerosis (MS): fingolimod reduces the rate of MS relapses by preventing leukocyte egress from the lymph nodes. Here, we examined the ability of S1P and fingolimod to act on the BBB, using an in vitro co-culture model that allowed us to investigate the effects of S1P on endothelial cells, astrocytes, and interactions between the two. Acting selectively on endothelial cells, S1P receptor signaling reduced cell death induced by inflammatory cytokines. When acting on astrocytes, fingolimod treatment induced the release of a factor, granulocyte macrophage colony-stimulating factor (GM-CSF) that reduced the effects of cytokines on endothelium. In an in vitro BBB model incorporating shear stress, S1P receptor modulation reduced leukocyte migration across the endothelial barrier, indicating a novel mechanism that might contribute to fingolimod efficacy in MS treatment.

Topics: Adult; Astrocytes; Blood-Brain Barrier; Cell Movement; Cell Survival; Cytokines; Endothelial Cells; Fingolimod Hydrochloride; Granulocyte-Macrophage Colony-Stimulating Factor; Healthy Volunteers; Humans; Inflammation; Leukocytes; Lysophospholipids; Microcirculation; Middle Aged; Multiple Sclerosis; Receptors, Lysosphingolipid; Signal Transduction; Sphingolipids; Sphingosine; Stress, Mechanical; Young Adult

Several studies support a protective effect of vitamin D on multiple sclerosis and experimental allergic encephalomyelitis (EAE), but the mechanisms of these favorable effects are unclear. Our study demonstrates that sphingosine 1-phosphate (S1P) is upregulated in the serum and spinal cords of EAE rats, but that vitamin D reverses the upregulation to alleviate inflammation. Vitamin D, however, cannot prevent the disease process, suggesting that other factors may be involved. To identify additional factors that might limit vitamin D efficacy, we assessed the effects of vitamin D on plasma gelsolin (pGSN), a regulator of S1P that is downregulated in the CSF of MS patients. Our results show that pGSN is downregulated in the serum of EAE rats, whereas its cellular form, cytoplasmic gelsolin (cGSN), is upregulated in the spinal cord of EAE rats. Importantly, vitamin D causes a downregulation of both pGSN and cGSN, which may counteract the positive effects of S1P decrease. Furthermore, 48 and 42 kDa caspase-3 cleavage products of cGSN are detected in EAE spinal cords, suggesting enhanced apoptotic activity, but these cleaved products undergo a similar decrease upon vitamin D treatment. To directly test the role of cGSN in the apoptotic process, we performed RNA interference in PC-12, a rat sympathetic nerve cell line. Results verify that cGSN suppresses apoptosis induced by TNF-α. Collectively, these results support a therapeutic effect of vitamin D that is derived from its ability to reduce S1P, but is limited by its simultaneous effect in reducing pGSN and cGSN. Based on these observations, we postulate that combined therapy with recombinant human pGSN and vitamin D may produce more beneficial effect in treating multiple sclerosis.

Topics: Animals; Apoptosis; Caspase 3; Encephalomyelitis, Autoimmune, Experimental; Gelsolin; Humans; Inflammation; Lysophospholipids; Male; Multiple Sclerosis; PC12 Cells; Rats; Rats, Inbred Lew; Sphingosine; Spinal Cord; Up-Regulation; Vitamin D

Sphingosine 1-phosphate (S1P) signaling regulates lymphocyte egress from lymphoid organs into systemic circulation. The sphingosine phosphate receptor 1 (S1P1) agonist FTY-720 (Gilenya) arrests immune trafficking and prevents multiple sclerosis (MS) relapses. However, alternative mechanisms of S1P-S1P1 signaling have been reported. Phosphoproteomic analysis of MS brain lesions revealed S1P1 phosphorylation on S351, a residue crucial for receptor internalization. Mutant mice harboring an S1pr1 gene encoding phosphorylation-deficient receptors (S1P1(S5A)) developed severe experimental autoimmune encephalomyelitis (EAE) due to autoimmunity mediated by interleukin 17 (IL-17)-producing helper T cells (TH17 cells) in the peripheral immune and nervous system. S1P1 directly activated the Jak-STAT3 signal-transduction pathway via IL-6. Impaired S1P1 phosphorylation enhances TH17 polarization and exacerbates autoimmune neuroinflammation. These mechanisms may be pathogenic in MS.

Topics: Animals; Autopsy; Brain; Encephalomyelitis, Autoimmune, Experimental; Female; Gene Expression Regulation; Humans; Inflammation; Interleukin-17; Interleukin-6; Janus Kinases; Lysophospholipids; Mice; Multiple Sclerosis; Phosphorylation; Receptors, Lysosphingolipid; Signal Transduction; Sphingosine; STAT3 Transcription Factor; Th17 Cells

We reveal how a N-scan SAR strategy (systematic substitution of each CH group with a N atom) was employed for quinolinone-based S1P(1) agonist 5 to modulate physicochemical properties and optimize in vitro and in vivo activity. The diaza-analog 17 displays improved potency (hS1P(1) RI; 17: EC(50)=0.020 μM, 120% efficacy; 5: EC(50)=0.070 μM, 110% efficacy) and selectivity (hS1P(3) Ca(2+) flux; 17: EC(50) >25 μM; 5: EC(50)=1.5 μM, 92% efficacy), as well as enhanced pharmacokinetics (17: CL=0.15 L/h/kg, V(dss)=5.1L/kg, T(1/2)=24h, %F=110; 5: CL=0.93L/h/kg, V(dss)=11L/kg, T(1/2)=15 h, %F=60) and pharmacodynamics (17: 1.0mg/kg po, 24h PLC POC=-67%; 5: 3mg/kg po, 24h PLC POC=-51%) in rat.

Topics: Animals; Area Under Curve; Cardiovascular Diseases; Chemistry, Physical; Drug Design; Female; Humans; Immunosuppressive Agents; In Vitro Techniques; Kinetics; Lymphocytes; Models, Chemical; Multiple Sclerosis; Quinolones; Rats; Rats, Inbred Lew; Receptors, Lysosphingolipid; Structure-Activity Relationship

CS-0777 is a selective sphingosine 1-phosphate receptor-1 modulator under investigation for treatment of multiple sclerosis (MS). We conducted an open-label, pilot study in 25 MS patients to assess the safety, pharmacokinetics, pharmacodynamics and exploratory efficacy of oral CS-0777 (0.1, 0.3 and 0.6 mg), administered once weekly or every other week for 12 weeks. CS-0777 resulted in a pronounced, dose-dependent decrease in lymphocytes and CD4 T cell subsets, which returned to baseline within 4 weeks after the last dose. Overall, CS-0777 was safe and well-tolerated. These results require confirmation in a double-blind, placebo-controlled and adequately powered phase 2 study in MS.

Topics: Administration, Oral; Amino Alcohols; CD4-Positive T-Lymphocytes; Dose-Response Relationship, Immunologic; Down-Regulation; Humans; Lymphocyte Subsets; Lymphopenia; Lysophospholipids; Multiple Sclerosis; Pilot Projects; Pyrroles; Receptors, Lysosphingolipid; Sphingosine

Fingolimod has recently been approved for the therapy of relapsing multiple sclerosis. This drug binds to different sphingosine-1-phosphate receptors.. To analyze basic mechanisms of action that can account for the efficacy of this drug in multiple sclerosis.. Fingolimod acts as an inverse agonist on sphingosine-1-phosphate receptors, inducing degradation of receptors. On lymphoid circulation, this effect causes retention in lymph nodes of naive and central memory T cells, including Th17 T lymphocytes, bearing CCR7 and CD62L receptors. As a result, the level of circulating T cells is markedly decreased. B ell circulation is impaired and complex effects on other immune cells are also induced. Fingolimod enters the central nervous system and binds to receptors on glial cells and neurons. In experimental autoimmune encephalomyelitis, the therapeutic efficacy of fingolimod is not only associated with a reduced entry of inflammatory cells into the nervous system, but also with a direct effect mostly on astroglial cells.. In multiple sclerosis patients, the available evidence indicates that fingolimod efficacy is directly associated with impairment of circulation of several T cell subsets and possibly B cells. Animal studies raise the possibility that an additional effect on glial cells might also contribute to the clinical efficacy.

Topics: Animals; Atrophy; B-Lymphocytes; Brain; Cell Movement; Drug Evaluation, Preclinical; Encephalomyelitis, Autoimmune, Experimental; Fingolimod Hydrochloride; Humans; Immunosuppressive Agents; L-Selectin; Lysophospholipids; Mice; Molecular Structure; Multiple Sclerosis; Neuroglia; Propylene Glycols; Rats; Receptors, CCR7; Receptors, Lysosphingolipid; Sphingosine; T-Lymphocyte Subsets; Th17 Cells

Modifying FTY720, an immunosuppressant modulator, led to a new series of well phosphorylated tetralin analogs as potent S1P1 receptor agonists. The stereochemistry effect of tetralin ring was probed, and (-)-(R)-2-amino-2-((S)-6-octyl-1,2,3,4-tetrahydronaphthalen-2-yl)propan-1-ol was identified as a good SphK2 substrate and potent S1P1 agonist with good oral bioavailability.

Topics: Administration, Oral; Animals; Crystallography, X-Ray; Immunosuppressive Agents; Lymphopenia; Mice; Models, Molecular; Multiple Sclerosis; Phosphorylation; Phosphotransferases (Alcohol Group Acceptor); Prodrugs; Receptors, Lysosphingolipid; Structure-Activity Relationship; Tetrahydronaphthalenes

Both cultured neonatal rat hippocampal neurons and differentiated oligodendrocytes rapidly metabolized exogenous C(2)- and C(6)-ceramides to sphingosine (Sph) and sphingosine 1-phosphate (S1P) but only minimally to C(16-24)-ceramides. Dihydrosphinolipids were unaffected but were increased by exogenous C(6)-dihydroceramide. Conversely, quantitative liquid chromatography-tandem mass spectrometry technology showed that exogenous S1P (0.25-10 microm) was rapidly metabolized to both Sph (a >200-fold increase) and predominantly C(18)-ceramide (a >2-fold increase). Longer treatments with either C(2)-ceramide (>2.5 microm) or S1P (10 microm) led to apoptotic cell death. Thus, there is an active sphingolipid salvage pathway in both neurons and oligodendrocytes. Staurosporine-induced cell death was shown to be associated with decreased S1P and increased Sph and C(16/18)-ceramide levels. The physiological significance of this observation was confirmed by the analysis of affected white matter and plaques from brains of multiple sclerosis patients in which reduced S1P and increased Sph and C(16/18)-ceramides were observed.

Topics: Animals; Animals, Newborn; Apoptosis; Autopsy; Brain; Case-Control Studies; Ceramides; Hippocampus; Humans; Lysophospholipids; Multiple Sclerosis; Neurons; Oligodendroglia; Rats; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Sphingosine

Topics: Administration, Oral; Animals; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Clinical Trials, Phase III as Topic; Fingolimod Hydrochloride; Humans; Lysophospholipids; Mitoxantrone; Multiple Sclerosis; Natalizumab; Propylene Glycols; Randomized Controlled Trials as Topic; Sphingosine

Topics: Administration, Oral; Animals; Clinical Trials as Topic; Drug Approval; Drug Industry; Fingolimod Hydrochloride; Humans; Lymphocytes; Lysophospholipids; Multiple Sclerosis; Propylene Glycols; Sphingosine

Topics: Animals; Autoantigens; Cell Movement; Central Nervous System; Down-Regulation; Fingolimod Hydrochloride; Humans; Immunosuppressive Agents; Lymph Nodes; Lysophospholipids; Multiple Sclerosis; Multiple Sclerosis, Relapsing-Remitting; Propylene Glycols; Sphingosine; T-Lymphocytes