fumarates and citraconic-acid

Fumaric acid ester-based drugs are used for the treatment of psoriasis and multiple sclerosis. All licensed fumaric acid ester drugs contain dimethylfumarate (DMF) as the main active component. Due to the expanding use of oral DMF there is growing scientific interest in determining its as-yet-unknown mechanism of action. However, the pharmacology and chemistry of DMF are often not fully considered in the design and interpretation of experiments; namely, that while DMF is plasma-membrane permeable and has strong effects on many cell types in vitro, it is rapidly metabolized into membrane-impermeable monomethylfumarate (MMF) in vivo. This can lead to significant biological effects being erroneously assigned to DMF. Understanding the pharmacology of DMF means that future work can more closely reflect the state in vivo.

Topics: Animals; Dermatologic Agents; Dimethyl Fumarate; Fumarates; Humans; Maleates; Prodrugs

Delayed-release dimethyl fumarate (DMF) is an oral therapy for relapsing multiple sclerosis with anti-inflammatory and neuroprotective properties. This 2-period crossover study was conducted to evaluate the potential for drug-drug interaction between DMF (240 mg twice daily) and a combined oral contraceptive (OC; norgestimate 250 μg, ethinyl estradiol 35 μg). Forty-six healthy women were enrolled; 32 completed the study. After the lead-in period (OC alone), 41 eligible participants were randomized 1:1 to sequence 1 (OC and DMF coadministration in period 1; OC alone in period 2) or sequence 2 (regimens reversed). Mean concentration profiles of plasma norelgestromin (primary metabolite of norgestimate) and ethinyl estradiol were superimposable following OC alone and OC coadministered with DMF, with 90% confidence intervals of geometric mean ratios for area under the plasma concentration-time curve over the dosing interval and peak plasma concentration contained within the 0.8-1.25 range. Low serum progesterone levels during combined treatment confirmed suppression of ovulation. The pharmacokinetics of DMF (measured via its primary active metabolite, monomethyl fumarate) were consistent with historical data when DMF was administered alone. No new safety concerns were identified. These results suggest that norgestimate/ethinyl estradiol-based OCs may be used with DMF without dose modification.

Topics: Administration, Oral; Adult; Area Under Curve; Contraceptives, Oral, Combined; Cross-Over Studies; Delayed-Action Preparations; Dimethyl Fumarate; Drug Combinations; Drug Interactions; Ethinyl Estradiol; Female; Fumarates; Humans; Immunosuppressive Agents; Maleates; Norgestrel; Oximes; Young Adult

Although the immunomodulatory and cytoprotective properties of itaconate have been studied extensively, it is not known whether its naturally occurring isomers mesaconate and citraconate have similar properties. Here, we show that itaconate is partially converted to mesaconate intracellularly and that mesaconate accumulation in macrophage activation depends on prior itaconate synthesis. When added to human cells in supraphysiological concentrations, all three isomers reduce lactate levels, whereas itaconate is the strongest succinate dehydrogenase (SDH) inhibitor. In cells infected with influenza A virus (IAV), all three isomers profoundly alter amino acid metabolism, modulate cytokine/chemokine release and reduce interferon signalling, oxidative stress and the release of viral particles. Of the three isomers, citraconate is the strongest electrophile and nuclear factor-erythroid 2-related factor 2 (NRF2) agonist. Only citraconate inhibits catalysis of itaconate by cis-aconitate decarboxylase (ACOD1), probably by competitive binding to the substrate-binding site. These results reveal mesaconate and citraconate as immunomodulatory, anti-oxidative and antiviral compounds, and citraconate as the first naturally occurring ACOD1 inhibitor.

Topics: Antiviral Agents; Carboxy-Lyases; Catalysis; Fumarates; Humans; Inflammation; Interferons; Macrophages; Maleates; Oxidative Stress

The methylotrophic bacterium Methylorubrum extorquens AM1 has the potential to become a platform organism for methanol-driven biotechnology. Its ethylmalonyl-CoA pathway (EMCP) is essential during growth on C1 compounds and harbors several CoA-activated dicarboxylic acids. Those acids could serve as precursor molecules for various polymers. In the past, two dicarboxylic acid products, namely mesaconic acid and 2-methylsuccinic acid, were successfully produced with heterologous thioesterase YciA from Escherichia coli, but the yield was reduced by product reuptake. In our study, we conducted extensive research on the uptake mechanism of those dicarboxylic acid products. By using 2,2-difluorosuccinic acid as a selection agent, we isolated a dicarboxylic acid import mutant. Analysis of the genome of this strain revealed a deletion in gene dctA2, which probably encodes an acid transporter. By testing additional single, double, and triple deletions, we were able to rule out the involvement of the two other DctA transporter homologs and the ketoglutarate transporter KgtP. Uptake of 2-methylsuccinic acid was significantly reduced in dctA2 mutants, while the uptake of mesaconic acid was completely prevented. Moreover, we demonstrated M. extorquens-based synthesis of citramalic acid and a further 1.4-fold increase in product yield using a transport-deficient strain. This work represents an important step towards the development of robust M. extorquens AM1 production strains for dicarboxylic acids. KEY POINTS: • 2,2-Difluorosuccinic acid is used to select for dicarboxylic acid uptake mutations. • Deletion of dctA2 leads to reduction of dicarboxylic acid uptake. • Transporter-deficient strains show improved production of citramalic acid.

Topics: Dicarboxylic Acids; Escherichia coli; Fumarates; Malates; Maleates; Methanol; Methylobacterium extorquens; Polymers; Succinates

Activating the cell survival modulator sigma 1 receptor (Sig1R) delays cone photoreceptor cell loss in Pde6βrd10/J (rd10) mice, a model of retinitis pigmentosa. Beneficial effects are abrogated in rd10 mice lacking NRF2, implicating NRF2 as essential to Sig1R-mediated cone neuroprotection. Here we asked whether activation of NRF2 alone is sufficient to rescue cones in rd10 mice.. Expression of antioxidant genes was evaluated in 661W cells and in mouse retinas after treatment with monomethylfumarate (MMF), a potent NRF2 activator. Rd10 mice were administered MMF (50 mg/kg) or the Sig1R ligand (+)-pentazocine (PTZ; 0.5 mg/kg) intraperitoneally (every other day, P14-42). Mice were evaluated for visual acuity (optokinetic tracking response), retinal function (electroretinography) and architecture (SD-OCT); histologic retinal sections were evaluated morphometrically.. MMF treatment increased Nrf2, Nqo1, Cat, Sod1, and Hmox1 expression in vitro and in vivo. Visual acuity of (+)-PTZ-treated rd10 mice was similar to wild-type mice; however, MMF treatment did not alter acuity compared with nontreated rd10 mice. Cone electroretinography b-wave amplitudes were greater in PTZ-treated than nontreated or MMF-treated rd10 mice. SD-OCT assessment of retinal thickness was greater in (+)-PTZ-treated mice versus nontreated or MMF-treated rd10 mice. Morphometric assessment of the outer nuclear layer revealed approximately 18 cells/100 µm retinal length in (+)-PTZ-treated rd10 mice, but only approximately 10 to 12 cells/100 µm in MMF-treated and nontreated rd10 retinas.. Activation of NRF2 using MMF, at least at our dosing regimen, is insufficient to attenuate catastrophic photoreceptor damage characteristic of rd10 mice. The data prompt investigation of additional mechanisms involved in Sig1R-mediated retinal neuroprotection.

Topics: Animals; Antioxidants; Disease Models, Animal; Electroretinography; Fumarates; Hydroquinones; Maleates; Mice, Knockout; Neuroprotection; Neuroprotective Agents; NF-E2-Related Factor 2; Pentazocine; Receptors, sigma; Retinal Cone Photoreceptor Cells; Retinal Rod Photoreceptor Cells; Retinitis Pigmentosa; Sigma-1 Receptor; Tomography, Optical Coherence; Up-Regulation; Visual Acuity

Power-to-X technologies have the potential to pave the way towards a future resource-secure bioeconomy as they enable the exploitation of renewable resources and CO

Topics: Carbon Dioxide; Catalysis; Cell Culture Techniques; Electrochemical Techniques; Formates; Fumarates; Maleates; Methylobacterium extorquens; Polymers; Succinates

Dimethylfumarate (DMF) has been approved the for treatment of relapsing-remitting multiple sclerosis. The mode of action of DMF and its assumed active primary metabolite monomethylfumarate (MMF) is still not fully understood, notably for brain resident cells. Therefore we investigated potential direct effects of DMF and MMF on microglia and indirect effects on oligodendrocytes. Primary rat microglia were differentiated into M1-like, M2-like and M0 phenotypes and treated in vitro with DMF or MMF. The gene expression of pro-inflammatory and anti-inflammatory factors such as growth factors (IGF-1), interleukins (IL-10, IL-1β), chemokines (CCl3, CXCL-10) as well as cytokines (TGF-1β, TNFα), iNOS, and the mannose receptor (MRC1) was examined by determining their transcription level with qPCR, and on the protein level by ELISA and FACS analysis. Furthermore, microglia function was determined by phagocytosis assays and indirect effects on oligodendroglial proliferation and differentiation. DMF treatment of M0 and M1-like polarized microglia demonstrated an upregulation of gene expression for IGF-1 and MRC1, but not on the protein level. While the phagocytic activity remained unchanged, DMF and MMF treated microglia supernatants led to an enhanced proliferation of oligodendrocyte precursor cells (OPC). These results suggest that DMF has anti-inflammatory effects on microglia which may result in enhanced proliferation of OPC.

Topics: Animals; Cell Differentiation; Cell Proliferation; Dimethyl Fumarate; Fumarates; Gene Expression Regulation; Insulin-Like Growth Factor I; Maleates; Microglia; Neuroprotective Agents; Oligodendroglia; Phagocytosis; Rats, Sprague-Dawley; Stem Cells

Post stroke recanalization has been associated with increased risk of oxidative stress. Stimulating endogenous antioxidant pathway by activation of nuclear factor erythroid-2-related factor-2 (Nrf2) plays a key role in neuronal defense against inflammation and oxidative stress in penumbra. Here, we explored whether monomethyl fumarate (MMF) could produce neuro-protection after ischemia/reperfusion (I/R) injury via Nrf2/HO1 activation. In male SD rats, middle cerebral artery was occluded for 90 min and confirmed using Laser Doppler flowmeter. MMF (10, 20 and 40 mg/kg) was administered in two divided doses at 30 min post ischemia and 5-10 min after reperfusion. After 24 h, effect on neurobehavioral parameters, infarct damage by TTC staining and MRI, oxidative stress and inflammatory cytokines were assessed. Expression studies of nuclear Nrf2 and cytoplasmic HO1 were performed in peri-infarct cortex and striatum; followed by dual immunofluorescence study to check the specific cell type. I/R induced neurobehavioral deficits and infarct damage were significantly (p < 0.05) attenuated by MMF (20 and 40 mg/kg). MMF, 20 mg/kg, significantly normalized I/R induced altered redox status and increased levels of TNF-α, IL-1β in the ipsilateral cortex. MRI data showed significantly reduced infarct in cortex but not in striatum after MMF treatment. Expression of nuclear Nrf2 and cytoplasmic HO1 were significantly (p < 0.05) increased in peri-infarct cortex after treatment with MMF. Additionally, dual immunofluorescence showed increased Nrf2 expression in neurons and HO1 expression in neurons as well as astrocytes in peri-infarct cortex after MMF treatment. Our results show the neuro-protective potential of MMF probably by restricting the progression of damage from striatum to cortex through activation of Nrf2/HO1 pathway in peri-infarct cortex.

Topics: Animals; Fumarates; Heme Oxygenase (Decyclizing); Infarction, Middle Cerebral Artery; Male; Maleates; Neuroprotective Agents; NF-E2-Related Factor 2; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction

Topics: Amino Acid Metabolism, Inborn Errors; Female; Fumarates; Humans; Infant, Newborn; Isovaleryl-CoA Dehydrogenase; Maleates; Succinates; Valerates

We determine if monomethyl fumarate (MMF) can protect the retina in mice subjected to light-induced retinopathy (LIR).. Albino BALB/c mice were intraperitoneally injected with 50 to 100 mg/kg MMF before or after exposure to bright white light (10,000 lux) for 1 hour. Seven days after light exposure, retinal structure and function were evaluated by optical coherence tomography (OCT) and electroretinography (ERG), respectively. Retinal histology also was performed to evaluate photoreceptor loss. Expression levels of Hcar2 and markers of microglia activation were measured by quantitative PCR (qPCR) in the neural retina with and without microglia depletion. At 24 hours after light exposure, retinal sections and whole mount retinas were stained with Iba1 to evaluate microglia status. The effect of MMF on the nuclear factor kB subunit 1 (NF-kB) and Nrf2 pathways was measured by qPCR and Western blot.. MMF administered before light exposure mediated dose-dependent neuroprotection in a mouse model of LIR. A single dose of 100 mg/kg MMF fully protected retinal structure and function without side effects. Expression of the Hcar2 receptor and the microglia marker Cd14 were upregulated by LIR, but suppressed by MMF. Depleting microglia reduced Hcar2 expression and its upregulation by LIR. Microglial activation, upregulation of proinflammatory genes (Nlrp3, Caspase1, Il-1β, Tnf-α), and upregulation of antioxidative stress genes (Hmox1) associated with LIR were mitigated by MMF treatment.. MMF can completely protect the retina from LIR in BALB/c mice. Expression of Hcar2, the receptor of MMF, is microglia-dependent in the neural retina. MMF-mediated neuroprotection was associated with attenuation of microglia activation, inflammation and oxidative stress in the retina.

Topics: Animals; Blotting, Western; Dermatologic Agents; Electroretinography; Fumarates; Gene Expression Regulation; Light; Male; Maleates; Mice; Mice, Inbred BALB C; NF-E2-Related Factor 2; NF-kappa B; Radiation Injuries, Experimental; Radiation-Protective Agents; Real-Time Polymerase Chain Reaction; Receptors, G-Protein-Coupled; Retina; Retinal Degeneration; Tomography, Optical Coherence

Oxidative stress and mitochondrial dysfunction contribute to the pathogenesis of neurodegenerative diseases and favor lipid peroxidation, leading to increased levels of 7β-hydroxycholesterol (7β-OHC) which induces oxiapoptophagy (OXIdative stress, APOPTOsis, autoPHAGY). The cytoprotective effects of dimethylfumarate (DMF), used in the treatment of relapsing remitting multiple sclerosis and of monomethylfumarate (MMF), its main metabolite, were evaluated on murine oligodendrocytes 158 N exposed to 7β-OHC (50 μM, 24 h) with or without DMF or MMF (25 μM). The activity of 7β-OHC in the presence or absence DMF or MMF was evaluated on several parameters: cell adhesion; plasma membrane integrity measured with propidium iodide (PI), trypan blue and fluoresceine diacetate (FDA) assays; LDH activity; antioxidant enzyme activities (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)); generation of lipid peroxidation products (malondialdehyde (MDA), conjugated dienes (CDs)) and protein oxidation products (carbonylated proteins (CPs)); reactive oxygen species (ROS) overproduction conducted with DHE and DHR123. The effect on mitochondria was determined with complementary criteria: measurement of succinate dehydrogenase activity, evaluation of mitochondrial potential (ΔΨm) and mitochondrial superoxide anions (O

Topics: Animals; Apoptosis; Autophagy; Cell Line; Cholesterol; Dimethyl Fumarate; Fumarates; Hydroxycholesterols; Lipid Peroxidation; Maleates; Mice; Mitochondria; Neuroprotective Agents; Oligodendroglia; Oxidative Stress

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a core enzyme of the aerobic glycolytic pathway with versatile functions and is associated with cancer development. Recently, Kornberg et al . published the detailed correlation between GAPDH and di

Topics: Catalytic Domain; Cell Proliferation; Fumarates; Glyceraldehyde-3-Phosphate Dehydrogenases; Humans; Maleates; Protein Binding; T-Lymphocytes

Topics: Aquaporin 3; Fumarates; Maleates; NF-E2-Related Factor 2; RNA, Messenger

Topics: Aquaporin 3; Fumarates; Maleates; NF-E2-Related Factor 2; RNA, Messenger

Mesaconate, a branched unsaturated dicarboxylic acid, has drawn great interest because of its versatile applications. In this work, we optimized the fermentation efficiency of Escherichia coli to produce mesaconate from glucose. We first drove the carbon flux to 2-ketoglutarate by overexpressing genes involved in TCA precursor pathway and anaplerotic pathways. Then, to increase the pool of phosphoenolpyruvate (PEP), an upstream precursor for 2-ketoglutarate, the phosphotransferase system (PTS) of E. coli was inactivated by deleting glucose PTS permease and the import of glucose was altered by overexpressing galactose/H

Topics: Biological Transport; Calcium-Binding Proteins; Carbon Cycle; Escherichia coli; Escherichia coli Proteins; Fermentation; Fumarates; Gene Deletion; Gene Expression; Glucose; Industrial Microbiology; Maleates; Monosaccharide Transport Proteins; Periplasmic Binding Proteins; Phosphoenolpyruvate; Phosphoenolpyruvate Sugar Phosphotransferase System; Pyruvate Synthase

Sepsis is a potentially fatal illness that can lead to impairment of multiple organs such as liver. The condition is deeply associated with oxidative stress and inflammation. Monomethyl fumarate (MMF) has manifested antioxidant and immunomodulatory properties. The aim of current study was to evaluate protective effects of MMF in sepsis-induced hepatic dysfunction.. Sepsis was induced by cecal ligation and puncture (CLP). Wistar rats were assigned to one of sham, CLP, CLP + dexamethasone (as positive control of inflammation) and CLP + MMF groups. Levels of serum IL-1β, IL-6, IL-10, AST, ALT and γ‑GT were quantified. Furthermore, Hepatic levels of GSH and MDA and mRNA expression of TNF and NFKBIA along with hepatic protein level of TLR-4 were assessed. Also, histopathological study of liver was carried out to evaluate hepatic injuries.. Septic rats demonstrated risen levels of IL-1β, IL-6, IL-10, AST, ALT and γ‑GT, while treatment with dexamethasone or MMF attenuated these levels. Moreover, enhancements in protein level of TLR-4 and mRNA levels of TNF and NFKBIA were observed in CLP rats. These elevations were mitigated in CLP-induced rats that were treated with either dexamethasone or MMF. Treatment with dexamethasone or MMF also shifted sepsis-induced disturbance in the levels of GSH and MDA towards sham levels. Hepato-protective effects of dexamethasone and MMF were further confirmed by histopathological observations.. Our findings imply that MMF alleviates sepsis-induced hepatic dysfunction by mitigating the inflammatory and oxidative state and this effect is at least partly mediated by the inhibition of TLR-4/NF-κB signalling pathway.

Topics: Animals; Antioxidants; Dexamethasone; Disease Models, Animal; Fumarates; Inflammation; Liver Diseases; Male; Maleates; NF-kappa B; NF-KappaB Inhibitor alpha; Oxidative Stress; Rats; Rats, Wistar; RNA, Messenger; Sepsis; Signal Transduction; Toll-Like Receptor 4

Oxidative stress contributes to inflammatory skin diseases, including psoriasis. Monomethylfumarate (MMF) is an antipsoriatic agent with a poorly understood mechanism of action. In other cell types MMF increases the expression of nuclear factor erythroid-derived 2-like 2 (Nrf2), a transcription factor that regulates cellular antioxidant responses, to reduce oxidative stress like that observed in inflammatory disorders such as multiple sclerosis. We tested the hypothesis that MMF enhances Nrf2 activity in keratinocytes, thereby improving their capacity to counteract environmental stresses. We used Western analysis, immunofluorescence, and real-time quantitative reverse-transcription polymerase chain reaction to examine the effect of MMF on the expression of Nrf2 and its targets. We also measured intracellular reactive oxygen species (ROS) levels following MMF treatment. Our data show that MMF increased total and nuclear Nrf2 levels in primary mouse keratinocytes and enhanced mRNA expression of several Nrf2-downstream effectors, including heme oxygenase-1 and peroxiredoxin-6. Moreover, MMF treatment attenuated the generation of ROS following hydrogen peroxide treatment. On the other hand, the expression and membranous localization of aquaporin-3 (AQP3), a glycerol channel implicated in keratinocyte differentiation, was stimulated by MMF, which also enhanced keratinocyte glycerol uptake. The Nrf2 activator sulforaphane also increased AQP3 levels, suggesting that AQP3 expression may be regulated by Nrf2. We show for the first time that MMF stimulates Nrf2 and AQP3 expression and function/activity in keratinocytes. This effect may account, in part, for the previously observed ability of MMF to inhibit proliferation and inflammatory mediator production and promote differentiation in keratinocytes and to treat psoriasis.

Topics: Animals; Animals, Newborn; Aquaporin 3; Base Sequence; Cells, Cultured; Fumarates; Gene Expression; Keratinocytes; Maleates; Mice; NF-E2-Related Factor 2; Psoriasis; RNA, Messenger

Topics: Dimethyl Fumarate; Fumarates; Healthy Volunteers; Humans; Hydrolases; Indoleamine-Pyrrole 2,3,-Dioxygenase; Kynurenine; Leukocytes, Mononuclear; Maleates; Primary Cell Culture; Psoriasis

HIV-associated neurocognitive disorders (HAND) affect about 50% of infected patients despite combined antiretroviral therapy (cART). Ongoing compartmentalized inflammation mediated by microglia which are activated by HIV-infected monocytes has been postulated to contribute to neurotoxicity independent from viral replication. Here, we investigated effects of teriflunomide and monomethylfumarate on monocyte/microglial activation and neurotoxicity. Human monocytoid cells (U937) transduced with a minimal HIV-Vector were co-cultured with human microglial cells (HMC3). Secretion of pro-inflammatory/neurotoxic cytokines (CXCL10, CCL5, and CCL2: p < 0.001; IL-6: p < 0.01) by co-cultures was strongly increased compared to microglia in contact with HIV-particles alone. Upon treatment with teriflunomide, cytokine secretion was decreased (CXCL10, 3-fold; CCL2, 2.5-fold; IL-6, 2.2-fold; p < 0.001) and monomethylfumarate treatment led to 2.9-fold lower CXCL10 secretion (p < 0.001). Reduced toxicity of co-culture conditioned media on human fetal neurons by teriflunomide (29%, p < 0.01) and monomethylfumarate (27%, p < 0.05) indicated functional relevance. Modulation of innate immune functions by teriflunomide and monomethylfumarate may target neurotoxic inflammation in the context of HAND.

Topics: Coculture Techniques; Crotonates; Culture Media, Conditioned; Dermatologic Agents; Dose-Response Relationship, Drug; Fetus; Fumarates; HIV-1; Humans; Hydroxybutyrates; Inflammation; Inflammation Mediators; Maleates; Microglia; Monocytes; Nitriles; Toluidines; U937 Cells

Dimethyl fumarate (DMF) is a new drug used to treat multiple sclerosis (MS) patients. Here, we examined the effects of DMF and the DMF metabolite monomethyl fumarate (MMF) on various activities of natural killer (NK) cells. We demonstrated that MMF augments the primary CD56(+), but not CD56(-), NK cell lysis of K562 and RAJI tumor cells. MMF induced NKp46 expression on the surface of CD56(+), but not CD56(-), NK cells after incubation for 24 h. This effect was closely correlated with the upregulation of CD107a expression on the surface of CD56(+) NK cells and the induction of Granzyme B release from these cells through this metabolite. An anti-NKp46 antibody inhibited the MMF-induced upregulation of CD107a and the lysis of tumor cells through CD56(+) NK cells. Thus, these results are the first to show that MMF augments CD56(+) NK cell lysis of tumor target cells, an effect mediated through NKp46. This novel effect suggests the use of MMF for therapeutic and/or preventive protocols in cancer.

Topics: Antibodies, Neutralizing; Antineoplastic Agents; CD56 Antigen; Cell Degranulation; Coculture Techniques; Cytotoxicity, Immunologic; Dimethyl Fumarate; Fumarates; Gene Expression Regulation, Leukemic; Granzymes; Humans; K562 Cells; Killer Cells, Natural; Lysosomal-Associated Membrane Protein 1; Maleates; Natural Cytotoxicity Triggering Receptor 1; Natural Cytotoxicity Triggering Receptor 3; Primary Cell Culture; Signal Transduction

Results of the very first experiments conducted to evaluate therapeutic potentials of a fumarate containing Fumaria indica extract and of fairly low daily oral doses of monomethyl fumarate for prevention of chronic unavoidable foot-shock stress-induced gastric ulcers, and possible involvement of diverse neuro-hormonal and oxidative process in their stress response desensitizing effects are reported and discussed in this article. Preventive effects of 21 daily oral 60, 120, and 240 mg/kg doses of a standardized 50 % methanolic F. indica extract (MFI) and 1.25, 2.50, and 5.00 mg/kg/day of pure monomethyl fumarate (MMF) were compared in rats subjected to one hour daily unavoidable foot-shocks. A pharmaceutically well-standardized Withania somnifera (WS) root extract was used as a reference herbal anti-stress agent in all experiments. Effects of the treatments on stress-induced alterations in body weight, adrenal and spleen weights, gastric ulcer and ulcer index, weight of glandular stomach, protective mucosal glycoprotein content, cellular proliferation, oxidative stress on stomach fundus, and brain tissues of male rats were quantified. Other parameters quantified were plasma corticosterone levels, brain monoamine levels, and expressions of the cytokines TNF-α, IL-10, and IL-1β in blood and brain of stressed and treated rats. Most but not every observed stress-induced anomalies were suppressed or completely prevented by both MFI and pure MMF treatments in dose-dependent manner. Qualitatively, the observed activity profiles of both of them were similar to those of WS dose tested. These results reveal that both MFI and MMF are potent gastro-protective agents against chronic unavoidable stress-induced ulcers and strongly suggest that they act as regulators or modulators of monoamine, corticosterone, and cytokine homeostasis.

Topics: Animals; Body Weight; Brain; Chronic Disease; Corticosterone; Cytokines; Fumarates; Fumaria; Male; Maleates; Methanol; Organ Size; Plant Extracts; Protective Agents; Rats; Real-Time Polymerase Chain Reaction; Stomach; Stomach Ulcer; Stress, Psychological

Reactive oxygen species play a key role in the pathogenesis of multiple sclerosis as they induce blood-brain barrier disruption and enhance transendothelial leukocyte migration. Thus, therapeutic compounds with antioxidant and anti-inflammatory potential could have clinical value in multiple sclerosis. The aim of the current study was to elucidate the therapeutic effects of monomethyl fumarate on inflammatory-mediated changes in blood-brain barrier function and gain insight into the underlying mechanism.. The effects of monomethyl fumarate on monocyte transendothelial migration across and adhesion to inflamed human brain endothelial cells (hCMEC/D3) were quantified using standardized in vitro migration and adhesion assays. Flow cytometry analysis and qPCR were used to measure the concomitant effects of monomethyl fumarate treatment on protein expression of cell adhesion molecules. Furthermore, the effects of monomethyl fumarate on the expression and nuclear localization of proteins involved in the activation of antioxidant and inflammatory pathways in human brain endothelial cells were elucidated using nuclear fractionation and Western blotting. Statistical analysis was performed using one-way ANOVA followed by the Bonferroni post-hoc test.. Our results show that monomethyl fumarate induced nuclear translocation of nuclear factor (erythroid-derived 2)-like 2 and concomitant production of the antioxidant enzymes heme oxygenase-1 and NADPH:quinone oxidoreductase-1 in brain endothelial cells. Importantly, monomethyl fumarate treatment markedly decreased monocyte transendothelial migration across and adhesion to inflamed human brain endothelial cells. Treatment of brain endothelial cells with monomethyl fumarate resulted in a striking reduction of vascular cell adhesion molecule expression. Surprisingly, monomethyl fumarate did not affect nuclear translocation of nuclear factor-кB suggesting that monomethyl fumarate potentially affects activity of nuclear factor-ĸB downstream of nuclear translocation.. Taken together, we show that monomethyl fumarate, the primary metabolite of dimethyl fumarate, which is currently used in the clinics for the treatment of relapsing-remitting multiple sclerosis, demonstrates beneficial therapeutic effects at the inflamed blood-brain barrier.

Topics: Anti-Inflammatory Agents; Antioxidants; Blood-Brain Barrier; Cell Adhesion; Cell Adhesion Molecules; Cells, Cultured; Coculture Techniques; Cytoprotection; Endothelial Cells; Fumarates; Heme Oxygenase-1; Humans; Leukocytes; Maleates; Multiple Sclerosis; NAD(P)H Dehydrogenase (Quinone); NF-E2-Related Factor 2; NF-kappa B; Transendothelial and Transepithelial Migration

Cobalamin C disease (cblC), which leads to methylmalonic acidemia with homocystinuria, is the most common inherited disorder of vitamin B12 metabolism. Reported ocular findings associated with cblC have been maculopathy, pigmentary retinopathy, and optic nerve atrophy. Cobalamin A disease (cblA) which causes an isolated methylmalonic acidemia without homocystinuria is rarer than cblC. This is the first detailed report of the ocular findings associated with cblA. We also describe the spectrum of ocular findings in our cblC patients.. A case series describing the ophthalmologic clinical course of six patients with a diagnosis of cobalamin C type and one patient with cobalamin A type of methylmalonic acidemia. Patients were diagnosed through biochemical laboratory testing and genetic analysis was conducted on most patients. Longitudinal fundus findings, optical coherence tomography (OCT), autofluorescence, and electrophysiology were followed in the patients.. The cblA patient demonstrated a relatively mild ocular phenotype with late-onset and slowly progressing temporal disc pallor and peripapillary atrophy in the second decade of life. The patient maintained good visual acuity and central vision, without evidence of maculopathy. The six cblC patients demonstrated a range of ocular findings from unremarkable and mild phenotypes to significant retinopathy, including bull's eye maculopathy, severe maculopathy with punched out chorioretinal atrophy, peripheral bone spicules, and optic nerve atrophy.. The spectrum of ocular manifestations seen with inherited disorders of cobalamin metabolism is wide, ranging from mild optic nerve atrophy to severe macular or retinal degeneration. This heterogeneity may in part reflect the associated biochemical phenotype, such as that observed between our cblA and cblC patients. We also observed heterogeneity within the cblC type in agreement with previous reports.

Topics: Amino Acid Metabolism, Inborn Errors; Electroretinography; Female; Follow-Up Studies; Fumarates; Homocysteine; Homocystinuria; Humans; Infant; Infant, Newborn; Male; Maleates; Optic Nerve Diseases; Optical Imaging; Retinal Degeneration; Tomography, Optical Coherence; Vision Disorders; Visual Acuity; Vitamin B 12 Deficiency

A promising approach to neurotherapeutics involves activating the nuclear-factor-E2-related factor 2 (Nrf2)/antioxidant response element signaling, which regulates expression of antioxidant, anti-inflammatory, and cytoprotective genes. Tecfidera, a putative Nrf2 activator, is an oral formulation of dimethylfumarate (DMF) used to treat multiple sclerosis. We compared the effects of DMF and its bioactive metabolite monomethylfumarate (MMF) on Nrf2 signaling and their ability to block 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced experimental Parkinson's disease (PD). We show that in vitro DMF and MMF activate the Nrf2 pathway via S-alkylation of the Nrf2 inhibitor Keap1 and by causing nuclear exit of the Nrf2 repressor Bach1. Nrf2 activation by DMF but not MMF was associated with depletion of glutathione, decreased cell viability, and inhibition of mitochondrial oxygen consumption and glycolysis rates in a dose-dependent manner, whereas MMF increased these activities in vitro However, both DMF and MMF upregulated mitochondrial biogenesis in vitro in an Nrf2-dependent manner. Despite the in vitro differences, both DMF and MMF exerted similar neuroprotective effects and blocked MPTP neurotoxicity in wild-type but not in Nrf2 null mice. Our data suggest that DMF and MMF exhibit neuroprotective effects against MPTP neurotoxicity because of their distinct Nrf2-mediated antioxidant, anti-inflammatory, and mitochondrial functional/biogenetic effects, but MMF does so without depleting glutathione and inhibiting mitochondrial and glycolytic functions. Given that oxidative damage, neuroinflammation, and mitochondrial dysfunction are all implicated in PD pathogenesis, our results provide preclinical evidence for the development of MMF rather than DMF as a novel PD therapeutic.. Almost two centuries since its first description by James Parkinson, Parkinson's disease (PD) remains an incurable disease with limited symptomatic treatment. The current study provides preclinical evidence that a Food and Drug Administration-approved drug, dimethylfumarate (DMF), and its metabolite monomethylfumarate (MMF) can block nigrostriatal dopaminergic neurodegeneration in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mouse model of PD. We elucidated mechanisms by which DMF and its active metabolite MMF activates the redox-sensitive transcription factor nuclear-factor-E2-related factor 2 (Nrf2) to upregulate antioxidant, anti-inflammatory, mitochondrial biosynthetic and cytoprotective genes to render neuroprotection via distinct S-alkylating properties and depletion of glutathione. Our data suggest that targeting Nrf2-mediated gene transcription using MMF rather than DMF is a promising approach to block oxidative stress, neuroinflammation, and mitochondrial dysfunction for therapeutic intervention in PD while minimizing side effects.

Topics: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; Animals; Antigens, CD; Cell Line, Transformed; Disease Models, Animal; Dose-Response Relationship, Drug; Fumarates; Gene Expression Regulation; Humans; Maleates; Mice; Mice, Inbred C57BL; Mice, Knockout; Neuroprotective Agents; NF-E2-Related Factor 2; Parkinsonian Disorders; Rats; Signal Transduction; Tyrosine

Oxidative stress plays an important role in cerebral ischemia-reperfusion injury. Dimethyl fumarate (DMF) and its primary metabolite monomethyl fumarate (MMF) are antioxidant agents that can activate the nuclear factor erythroid-2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway and induce the expression of antioxidant proteins. Here, we evaluated the impact of DMF and MMF on ischemia-induced brain injury and whether the Nrf2 pathway mediates the effects provided by DMF and MMF in cerebral ischemia-reperfusion injury. Using a mouse model of transient focal brain ischemia, we show that DMF and MMF significantly reduce neurological deficits, infarct volume, brain edema, and cell death. Further, DMF and MMF suppress glial activation following brain ischemia. Importantly, the protection of DMF and MMF was mostly evident during the subacute stage and was abolished in Nrf2

Topics: Animals; Brain Edema; Calcium-Binding Proteins; Dimethyl Fumarate; Disease Models, Animal; Dose-Response Relationship, Drug; Fumarates; Glial Fibrillary Acidic Protein; Glutathione; Immunosuppressive Agents; Infarction, Middle Cerebral Artery; Maleates; Malondialdehyde; Mice; Mice, Inbred C57BL; Microfilament Proteins; Neurologic Examination; Neuroprotective Agents; NF-E2-Related Factor 2; Oxidative Stress; Recovery of Function; Reperfusion Injury; Time Factors

Dicarboxylic acids are attractive biosynthetic targets due to their broad applications and their challenging manufacturing process from fossil fuel feedstock. Mesaconate is a branched, unsaturated dicarboxylic acid that can be used as a co-monomer to produce hydrogels and fire-retardant materials. In this study, we engineered nonphosphorylative metabolism to produce mesaconate from d-xylose and l-arabinose. This nonphosphorylative metabolism is orthogonal to the intrinsic pentose metabolism in Escherichia coli and has fewer enzymatic steps and a higher theoretical yield to TCA cycle intermediates than the pentose phosphate pathway. Here mesaconate production was enabled from the d-xylose pathway and the l-arabinose pathway. To enhance the transportation of d-xylose and l-arabinose, pentose transporters were examined. We identified the pentose/proton symporter, AraE, as the most effective transporter for both d-xylose and l-arabinose in mesaconate production process. Further production optimization was achieved by operon screening and metabolic engineering. These efforts led to the engineered strains that produced 12.5g/l and 13.2g/l mesaconate after 48h from 20g/l of d-xylose and l-arabinose, respectively. Finally, the engineered strain overexpressing both l-arabinose and d-xylose operons produced 14.7g/l mesaconate from a 1:1 d-xylose and l-arabinose mixture with a yield of 85% of the theoretical maximum. (0.87g/g). This work demonstrates an effective system that converts pentoses into a value-added chemical, mesaconate, with promising titer, rate, and yield.

Topics: Arabinose; Biosynthetic Pathways; Escherichia coli; Escherichia coli Proteins; Fumarates; Genetic Enhancement; Lignin; Maleates; Metabolic Engineering; Metabolic Networks and Pathways; Pentoses; Phosphorylation; Xylose

Delayed-release dimethyl fumarate (DMF) is an approved treatment for multiple sclerosis (MS). Microglia are considered central to MS pathophysiology, however the effects of DMF and the primary metabolite monomethyl fumarate (MMF) on microglia are not well characterized. We demonstrated that DMF and MMF altered transcriptional responses in primary microglia related to the nuclear factor (erythroid-derived 2)-like 2 pathway. Additionally, through an NRF2 independent manner, DMF, but not MMF significantly reduced production of proinflammatory mediators in classically activated microglia, and further rescued mitochondrial respiratory deficits in primary cortical neurons that were induced by activated microglia. These data suggest the mechanism of action of DMF may involve modulation of microglia inflammatory responses and attenuation of neurotoxicity.

Topics: Animals; Cells, Cultured; Cellular Microenvironment; Dimethyl Fumarate; Fumarates; Immunosuppressive Agents; Inflammation Mediators; Male; Maleates; Mice; Mice, Inbred C57BL; Microglia; Neurons; Neuroprotective Agents; Phenotype; Rats; Rats, Sprague-Dawley

Extracellular matrix metalloproteinase inducer (EMMPRIN, CD147) is a transmembrane glycoprotein that is upregulated on leukocytes in active lesions in multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). Administration of anti-EMMPRIN Abs reduces the severity of EAE. Minocycline is a tetracycline antibiotic with immune-modulatory properties that decreases the severity of EAE; it was recently found to attenuate the conversion from a first demyelinating event to clinically definite MS in a phase III trial. We investigated whether and how minocycline affects the expression of EMMPRIN on T cells in culture and in mice afflicted with EAE. EMMPRIN expression in cultures of mouse splenocytes or human PBMCs was elevated upon polyclonal T cell activation, and this was reduced by minocycline correspondent with decreased P-Akt levels. An established MS medication, IFN-β, also diminished EMMPRIN levels on human cells whereas this was not readily observed for fingolimod or monomethylfumarate. In EAE-afflicted mice, minocycline treatment significantly reduced EMMPRIN levels on splenic lymphocytes at the presymptomatic (day 7) phase, and prevented the development of disease. Day 7 spleen transcripts from minocycline-treated EAE mice had a significantly lower MMP-9/TIMP-1 ratio, and significantly lower MCT-1 and CD98 levels, factors associated with EMMPRIN function. Day 16 (peak clinical severity) CNS samples from EAE mice had prominent representation of inflammatory perivascular cuffs, inflammatory molecules and EMMPRIN, and these were abrogated by minocycline. Overall, minocycline attenuated the activation-induced elevation of EMMPRIN on T cells in culture and in EAE mice, correspondent with reduced immune function and EAE CNS pathology.

Topics: Animals; Anti-Bacterial Agents; Basigin; Central Nervous System; Clinical Trials, Phase III as Topic; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Fingolimod Hydrochloride; Fumarates; Humans; Interferon-beta; Lymphocyte Activation; Maleates; Matrix Metalloproteinase 9; Mice; Mice, Inbred C57BL; Minocycline; Monocytes; Multiple Sclerosis; T-Lymphocytes; Tissue Inhibitor of Metalloproteinase-1

Monomethylfumarate (MMF) is thought to be the bioactive ingredient of the drug Fumaderm (Biogen Idec, Cambridge, MA), licensed in Germany since 1994 for the treatment of moderate-to-severe psoriasis. Psoriasis is a common inflammatory hyperproliferative skin disorder that involves cross-talk between different cell types, including immune cells and keratinocytes. Psoriatic lesions are characterized by hyperproliferation, aberrant differentiation, and inflammation, with the psoriatic cytokine network maintained by communication between immune cells and keratinocytes. Recently, there is increasing evidence regarding the pivotal role of keratinocytes in mediating the disease process, and these cells can be regarded as safe therapeutic targets. From the data available on human subjects treated with Fumaderm, MMF is an effective antipsoriatic agent with known effects on immune cells. However, little is known about its direct effects on keratinocytes. We hypothesized that MMF has direct antiproliferative, prodifferentiative, and anti-inflammatory effects on keratinocytes. Indeed, MMF dose-dependently inhibited [(3)H]thymidine incorporation into DNA, indicating a direct antiproliferative action on keratinocytes. MMF significantly increased the protein level of keratin 10, the early keratinocyte differentiation marker, and the activity of transglutaminase, a late differentiation marker. These results are consistent with an ability of MMF to promote keratinocyte differentiation and inhibit proliferation, thereby improving psoriatic lesions. In 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced keratinocytes, MMF significantly inhibited the expression of the proinflammatory cytokines, tumor necrosis factor-α (TNFα), interleukin-6, and interleukin-1α as well as the production of TNFα. Our results support the notion that MMF has direct antiproliferative, prodifferentiative, and anti-inflammatory effects on keratinocytes, highlighting its potential use as a multifactorial antipsoriatic agent.

Topics: Animals; Anti-Inflammatory Agents; Cell Differentiation; Cell Proliferation; Dose-Response Relationship, Drug; Endothelial Cells; Female; Fumarates; Gene Expression Regulation; Keratinocytes; Male; Maleates; Mice; Psoriasis; RNA, Messenger; Tumor Necrosis Factor-alpha

Dimethyl fumarate (DMF) is a newly approved drug for the treatment of relapsing forms of multiple sclerosis and relapsing-remitting multiple sclerosis. Here, we investigated the effects of DMF and its metabolites mono-methylfumarate (MMF and methanol) on different gastrointestinal cancer cell lines and the underlying molecular mechanisms involved.. Cell viability was measured by the MTT or CCK8 assay. Protein expressions were measured by Western blot analysis. LDH release, live- and dead-cell staining, intracellular GSH levels, and mitochondrial membrane potential were examined by using commercial kits.. DMF but not MMF induced cell necroptosis, as demonstrated by the pharmacological tool necrostatin-1, transmission electron microscopy, LDH and HMGB1 release in CT26 cells. The DMF-induced decrease in cellular GSH levels as well as cell viability and increase in reactive oxygen species (ROS) were inhibited by co-treatment with GSH and N-acetylcysteine (NAC) in CT26 cells. DMF activated JNK, p38 and ERK MAPKs in CT26 cells and JNK, p38 and ERK inhibitors partially reversed the DMF-induced decrease in cell viability. GSH or NAC treatment inhibited DMF-induced JNK, p38, and ERK activation in CT26 cells. DMF but not MMF increased autophagy responses in SGC-7901, HCT116, HT29 and CT26 cancer cells, but autophagy inhibition did not prevent the DMF-induced decrease in cell viability.. DMF but not its metabolite MMF induced necroptosis in colon cancer cells through a mechanism involving the depletion of GSH, an increase in ROS and activation of MAPKs.

Topics: Animals; Apoptosis; Cell Line, Tumor; Cell Survival; Colonic Neoplasms; Dimethyl Fumarate; Fumarates; Glutathione; HMGB1 Protein; Humans; L-Lactate Dehydrogenase; Maleates; MAP Kinase Signaling System; Membrane Potential, Mitochondrial; Methanol; Mice; Mitogen-Activated Protein Kinases; Necrosis; Reactive Oxygen Species

Fumarate-containing pharmaceuticals are potent therapeutic agents that influence multiple cellular pathways. Despite proven clinical efficacy, there is a significant lack of data that directly defines the molecular mechanisms of action of related, yet distinct fumarate compounds. We systematically compared the impact of dimethyl fumarate (DMF), monomethyl fumarate (MMF) and a mixture of monoethyl fumarate salts (Ca(++), Mg(++), Zn(++); MEF) on defined cellular responses. We demonstrate that DMF inhibited NF-κB-driven cytokine production and nuclear translocation of p65 and p52 in an Nrf2-independent manner. Equivalent doses of MMF and MEF did not affect NF-κB signaling. These results highlight a key difference in the biological impact of related, yet distinct fumarate compounds.

Topics: Active Transport, Cell Nucleus; Animals; Bone Neoplasms; Burkitt Lymphoma; Cations; Cell Line, Tumor; Cells, Cultured; Cytokines; Dimethyl Fumarate; Fumarates; Humans; In Vitro Techniques; Lymphocytes; Maleates; Mice; Mice, Knockout; Molecular Structure; Neoplasm Proteins; NF-E2-Related Factor 2; NF-kappa B; NF-kappa B p52 Subunit; Osteosarcoma; Signal Transduction; Spleen; Transcription Factor RelA

Pseudomonas aeruginosa, Yersinia pestis, and many other bacteria are able to utilize the C5-dicarboxylic acid itaconate (methylenesuccinate). Itaconate degradation starts with its activation to itaconyl coenzyme A (itaconyl-CoA), which is further hydrated to (S)-citramalyl-CoA, and citramalyl-CoA is finally cleaved into acetyl-CoA and pyruvate. The xenobiotic-degrading betaproteobacterium Burkholderia xenovorans possesses a P. aeruginosa-like itaconate degradation gene cluster and is able to grow on itaconate and its isomer mesaconate (methylfumarate). Although itaconate degradation proceeds in B. xenovorans in the same way as in P. aeruginosa, the pathway of mesaconate utilization is not known. Here, we show that mesaconate is metabolized through its hydration to (S)-citramalate. The latter compound is then metabolized to acetyl-CoA and pyruvate with the participation of two enzymes of the itaconate degradation pathway, a promiscuous itaconate-CoA transferase able to activate (S)-citramalate in addition to itaconate and (S)-citramalyl-CoA lyase. The first reaction of the pathway, the mesaconate hydratase (mesaconase) reaction, is catalyzed by a class I fumarase. As this enzyme (Bxe_A3136) has similar efficiencies (kcat/Km) for both fumarate and mesaconate hydration, we conclude that B. xenovorans class I fumarase is in fact a promiscuous fumarase/mesaconase. This promiscuity is physiologically relevant, as it allows the growth of this bacterium on mesaconate as a sole carbon and energy source.

Topics: Acetyl Coenzyme A; Burkholderia; Fumarate Hydratase; Fumarates; Hydro-Lyases; Kinetics; Malates; Maleates; Metabolic Networks and Pathways; Pyruvic Acid; Substrate Specificity; Succinates

Mesaconate is an intermediate in the glutamate degradation pathway of microorganisms such as Clostridium tetanomorphum. However, metabolic engineering to produce mesaconate has not been reported previously. In this work, two enzymes involved in mesaconate production, glutamate mutase and 3-methylaspartate ammonia lyase from C. tetanomorphum, were recombinantly expressed in Escherichia coli. To improve mesaconate production, reactivatase of glutamate mutase was discovered and adenosylcobalamin availability was increased. In addition, glutamate mutase was engineered to improve the in vivo activity. These efforts led to efficient mesaconate production at a titer of 7.81 g/L in shake flask with glutamate feeding. Then a full biosynthetic pathway was constructed to produce mesaconate at a titer of 6.96 g/L directly from glucose. In summary, we have engineered an efficient system in E. coli for the biosynthesis of mesaconate.

Topics: Bacterial Proteins; Clostridium tetanomorphum; Escherichia coli; Fumarates; Intramolecular Transferases; Maleates

Dimethyl fumarate (DMF) is approved for disease-modifying treatment of patients with relapsing-remitting multiple sclerosis. Animal experiments suggested that part of its therapeutic effect is due to a reduction of T-cell infiltration of the central nervous system (CNS) by uncertain mechanisms. Here we evaluated whether DMF and its primary metabolite monomethyl fumarate (MMF) modulate pro-inflammatory intracellular signaling and T-cell adhesiveness of nonimmortalized single donor human brain microvascular endothelial cells at low passages. Neither DMF nor MMF at concentrations of 10 or 50 µM blocked the IL-1β-induced nuclear translocation of NF-κB/p65, whereas the higher concentration of DMF inhibited the nuclear entry of p65 in human umbilical vein endothelium cultured in parallel. DMF and MMF also did not alter the IL-1β-stimulated activation of p38 MAPK in brain endothelium. Furthermore, neither DMF nor MMF reduced the basal or IL-1β-inducible expression of ICAM-1. In accordance, both fumaric acid esters did not reduce the adhesion of activated Jurkat T cells to brain endothelium under basal or inflammatory conditions. Therefore, brain endothelial cells probably do not directly mediate a potential blocking effect of fumaric acid esters on the inflammatory infiltration of the CNS by T cells.

Topics: Active Transport, Cell Nucleus; Brain; Cell Adhesion; Cell Line; Dimethyl Fumarate; Endothelium, Vascular; Fumarates; Human Umbilical Vein Endothelial Cells; Humans; Immunosuppressive Agents; Intercellular Adhesion Molecule-1; Interleukin-1beta; Maleates; Microvessels; Multiple Sclerosis; T-Lymphocytes; Transcription Factor RelA

Experimental autoimmune encephalomyelitis (EAE) is a CD4⁺ T cell mediated inflammatory demyelinating disease that is induced in mice by administration of peptides derived from myelin proteins. We developed EAE in SJL mice by administration of PLP139-151 peptide. The effect of treating these mice with 1α,25-Dihydroxyvitamin D₃ (vitamin D₃), or with monomethyl fumarate (MMF) was then examined. We observed that both vitamin D₃ and MMF inhibited and/or prevented EAE in these mice. These findings were corroborated with isolating natural killer (NK) cells from vitamin D₃-treated or MMF-treated EAE mice that lysed immature or mature dendritic cells. The results support and extend other findings indicating that an important mechanism of action for drugs used to treat multiple sclerosis (MS) is to enhance NK cell lysis of dendritic cells.

Topics: Adjuvants, Immunologic; Animals; Cholecalciferol; Dendritic Cells; Encephalomyelitis, Autoimmune, Experimental; Flow Cytometry; Fumarates; Killer Cells, Natural; Maleates; Mice; Myelin Proteolipid Protein; Phenotype

Migration of immunocompetent cells into the central nervous system represents a key event in the immunopathogenesis of multiple sclerosis (MS). Fumaric acid esters have recently been approved for patients with MS. Their mode of action is not fully understood so far. We analyzed the effect of monomethylfumarate (MMF), the immediate metabolite of dimethylfumarate, on migration of lymphocytes and macrophages. Peripheral blood mononuclear cells (PBMCs) were isolated from patients with MS and healthy donors. PBMCs were treated with MMF in vitro and their migratory capacity was studied in a Boyden chamber assay. In addition, expression of matrix metalloproteinases (MMPs), chemokine receptors, adhesion molecules, and molecules of the oxidative stress cascade was assessed. MMF decreased the migratory capacity of T lymphocytes, but not of macrophages. Lymphocytes as well as macrophages responded to MMF by the upregulation of oxidative stress molecules; however, no effect was seen on the expression of MMPs, chemokine receptors, and adhesion molecules. There was no difference in comparison with cells from healthy controls. MMF reduces the migratory activity of lymphocytes most likely by changing their activational state. This points to a potential novel mode of action differentiating this drug from other available immunotherapies.

Topics: Adult; Antigens, CD; Cell Movement; Female; Flow Cytometry; Fumarates; Gene Expression Regulation; Glutamate-Cysteine Ligase; Heme Oxygenase-1; Humans; Leukocytes, Mononuclear; Male; Maleates; Multiple Sclerosis; NAD(P)H Dehydrogenase (Quinone); NF-E2-Related Factor 2; Signal Transduction; Statistics, Nonparametric; Time Factors

In this study, a series of semi-interpenetrating polymer network (IPN) hydrogels were prepared as a support material for lipase immobilization. Hydrogels were synthesized via free radical polymerization in different compositions of chitosan (Cs), acrylamide (AAm), and citraconic acid (CA). The swelling values of the hydrogels were found to be 240-400%. Depending on the swelling results, Cs-P(AAm-co-CA)-2 hydrogel was chosen for lipase immobilization. Three different types of immobilization technique were carried out. Lipase release behaviors were investigated, and immobilization yields of three immobilization methods were compared, and the maximum immobilization yield value was determined for entrapment method.

Topics: Acrylamide; Chitosan; Delayed-Action Preparations; Drug Delivery Systems; Enzymes, Immobilized; Fumarates; Humans; Hydrogels; Lipase; Maleates; Polymers

Sickle retinopathy (SR) is a major cause of vision loss in sickle cell disease (SCD). There are no strategies to prevent SR and treatments are extremely limited. The present study evaluated (1) the retinal pigment epithelial (RPE) cell as a hemoglobin producer and novel cellular target for fetal hemoglobin (HbF) induction, and (2) monomethylfumarate (MMF) as an HbF-inducing therapy and abrogator of oxidative stress and inflammation in SCD retina.. Human globin gene expression was evaluated by RT-quantitative (q)PCR in the human RPE cell line ARPE-19 and in primary RPE cells isolated from Townes humanized SCD mice. γ-Globin promoter activity was monitored in KU812 stable dual luciferase reporter expressing cells treated with 0 to 1000 μM dimethylfumarate, MMF, or hydroxyurea (HU; positive control) by dual luciferase assay. Reverse transcriptase-qPCR, fluorescence-activated cell sorting (FACS), immunofluorescence, and Western blot techniques were used to evaluate γ-globin expression and HbF production in primary human erythroid progenitors, ARPE-19, and normal hemoglobin producing (HbAA) and homozygous β(s) mutation (HbSS) RPE that were treated similarly, and in MMF-injected (1000 μM) HbAA and HbSS retinas. Dihydroethidium labeling and nuclear factor (erythroid-derived 2)-like 2 (Nrf2), IL-1β, and VEGF expression were also analyzed.. Retinal pigment epithelial cells express globin genes and synthesize adult and fetal hemoglobin MMF stimulated γ-globin expression and HbF production in cultured RPE and erythroid cells, and in HbSS mouse retina where it also reduced oxidative stress and inflammation.. The production of hemoglobin by RPE suggests the potential involvement of this cell type in the etiology of SR. Monomethylfumarate influences multiple parameters consistent with improved retinal health in SCD and may therefore be of therapeutic potential in SR treatment.

Topics: Adult; Animals; Antioxidants; Cells, Cultured; Disease Models, Animal; Erythroid Cells; Fetal Hemoglobin; Fumarates; gamma-Globins; Humans; Maleates; Mice; NF-E2-Related Factor 2; Oxidative Stress; Retina; Retinal Pigment Epithelium

A novel pH-sensitive polymeric micelle was reported. Methoxy poly(ethylene glycol)-b-poly(ϵ-caprolactone) copolymer with citraconic amide as pH-sensitive bond was synthesized (mPEG-pH-PCL). The copolymers self-assembled into micelles to encapsulate anticancer drug doxorubicin (DOX). The morphology, size and size distribution, drug release profile and in vitro anticancer activity of the DOX loaded mPEG-pH-PCL micelles were studied. The results showed that the mean size of the micelles was around 120 nm, the drug loading content and encapsulation efficiency of the mPEG-pH-PCL micelles were 6.8% and 54.3%, respectively. The mean diameter and size distribution of the mPEG-pH-PCL micelles increased significantly when soaking in medium with pH 5.5. The drug release of micelles in pH 5.5 was much faster than that in pH 7.4. The confocal laser microscopy and flow cytometry measurements indicated that the weak acidity of endosomes broke the citraconic amide bonds in the copolymer backbones and triggered the fast release of DOX. The in vitro IC50 of the drug loaded mPEG-pH-PCL micelles was lower than that of drug loaded polymeric micelles without pH-sensitivity to both HepG2 and 4T1 cancer cells.

Topics: Animals; Antineoplastic Agents; Cell Line, Tumor; Cell Survival; Doxorubicin; Drug Carriers; Drug Liberation; Fumarates; Hep G2 Cells; Humans; Hydrogen-Ion Concentration; Maleates; Mice; Micelles; Microscopy, Confocal; Molecular Structure; Molecular Weight; Particle Size; Polyesters; Polyethylene Glycols; Surface Properties

The new reactions of some divalent and trivalent transition metal ions (Mn(II), Cr(III), and Fe(III)) with citraconic acid has been studied. The obtained results indicate the formation of citraconic acid compounds with molar ratio of metal to citraconic acid of 2:2 or 2:3 with general formulas Mn2(C5H4O4)2 or M2(C5H4O4)3⋅nH2O where n=6 for Cr, and Fe(III). The thermal decomposition of the crystalline solid complexes was investigated. The IR spectra of citraconate suggested that the carboxylic groups are bidentatically bridging and chelating. In the course of decomposition the complexes are dehydrated and then decompose either directly to oxides in only one step or with intermediate formation of oxocarbonates. This proposal dealing the preparation of MnO2, Fe2O3 and Cr2O3 nanoparticles. The crystalline structure of oxide products were checked by X-ray powder diffraction (XRD), and the morphology of particles by scanning electron microscopy (SEM).

Topics: Chelating Agents; Chromium; Coordination Complexes; Ferric Compounds; Fumarates; Maleates; Manganese; Nanoparticles; X-Ray Diffraction

Oxidative stress is a common pathological factor in degenerative retinal diseases; therefore, identifying novel strategies for its limitation is critically important and highly relevant clinically. Along these lines, our present goal was to evaluate the effect(s) of the fumarate ester and antipsoriatic agent monomethylfumarate (MMF) on the expression and functional activity of the cystine/glutamate exchanger SLC7A11 (system xc(-)), a transport system critical to potentiation of antioxidant signaling in retina.. ARPE-19 and primary mouse RPE cells were cultured in the presence or absence of varying concentrations of MMF (0-5000 μM) for 0 to 24 hours. MMF (10 mM) was also delivered intravitreally to mouse eyes. RT-PCR, radiolabeled uptake, Western blotting, and glutathione (GSH) assays were then used to evaluate the effects of MMF on endogenous antioxidant machinery.. MMF induced system xc(-), Nrf2, and hypoxia-inducible factor 1α (Hif-1α) in cultured RPE cells. Additionally, the compound was recognized as a transportable substrate by the Na(+)-coupled monocarboxylate transporter SLC5A8 (SMCT1). In vivo these factors were evidenced by a significant increase in retinal levels of GSH.. MMF stimulates multiple pathways in retinal cells that potentiate cellular events leading to the upregulation of genes/mechanisms that function to protect retina against various forms of insult; upregulation of system xc(-) is one such consequence. To our knowledge, this is the first report that fumarate esters, compounds already employed clinically for other indications, are effective in retina via xc(-) induction. This novel, hitherto unknown mechanism helps to explain the antioxidant feature of these compounds and highlights their therapeutic potential in retina.

Topics: Amino Acid Transport System y+; Animals; Cells, Cultured; Dermatologic Agents; Epithelial Cells; Eye; Fumarates; Glutathione; Hypoxia-Inducible Factor 1, alpha Subunit; Maleates; Mice; Mice, Inbred BALB C; NF-E2-Related Factor 2; Retinal Pigment Epithelium; RNA, Messenger; Up-Regulation

The blood-brain barrier (BBB) is composed of a network of tight junctions (TJ) which interconnect cerebral endothelial cells (EC). Alterations in the TJ proteins are common in inflammatory diseases of the central nervous system (CNS) like multiple sclerosis (MS). Modulation of the BBB could thus represent a therapeutic mechanism. One pathway to modulate BBB integrity could be the induction of nuclear-factor (erythroid derived 2) related factor-2 (Nrf2) mediated oxidative stress responses which are targeted by fumaric acid esters (FAE). Here we analyze effects of FAE on the expression of TJ proteins in the human cerebral endothelial cell line hCMEC/D3 and experimental autoimmune encephalomyelitis (EAE). We show that dimethylfumarate (DMF) and its primary metabolite monomethylfumarate (MMF) induce the expression of the Nrf2/NQO1 pathway in endothelial cells. Neither MMF nor DMF had a consistent modulatory effect on the expression of TJ molecules in hCMEC/D3 cells. Tumor necrosis factor (TNFα)-induced downregulation of TJ proteins was at least partially reversed by treatment with FAE. However, DMF had no effect on claudin-5 expression in EAE, despite its effect on the clinical score and infiltration of immune cells. These data suggest that the modulation of the BBB is not a major mechanism of action of FAE in inflammatory demyelinating diseases of the CNS.

Topics: Animals; Blood-Brain Barrier; Brain; Cell Line; Cell Nucleus; Claudin-5; Dimethyl Fumarate; Encephalomyelitis, Autoimmune, Experimental; Epithelial Cells; Female; Fumarates; Humans; Hydroquinones; Maleates; Mice; Mice, Inbred C57BL; NF-E2-Related Factor 2; Occludin; Tight Junction Proteins; Tumor Necrosis Factor-alpha; Zonula Occludens-1 Protein

Mast cells modulate autoimmune diseases such as psoriasis and multiple sclerosis. Fumaric acid esters (FAEs) are widely used for the treatment of psoriasis, and dimethylfumarate (DMF) has recently been approved for multiple sclerosis. In this study, we analysed the cytotoxic effect of FAEs on human mast cells. Specifically, cell death was analysed in the human mast cell line HMC-1 and in primary cord blood-derived mast cells (CBMCs) after incubation with fumaric acid (FA), monomethylfumarate (MMF), DMF and calcium bis(monomethylfumarate) (Ca-MF). Our data show that only DMF potently induces apoptotic cell death in HMC-1 cells and CBMCs. DMF-mediated apoptosis was associated with increased expression of Bax and Bak and activation of caspase-9 and caspase-6. Interestingly, DMF also enhanced the sensitivity of CBMCs towards TRAIL- and dexamethasone-induced apoptosis. These findings demonstrate for the first time that DMF induces apoptosis of human mast cells, primarily via the mitochondrial apoptotic pathway. Our study contributes to the understanding of the beneficial effects of FAEs in autoimmune diseases and provides a rationale for exploiting FAEs for other diseases associated with mast cells.

Topics: Apoptosis; bcl-2 Homologous Antagonist-Killer Protein; bcl-2-Associated X Protein; Calcium; Caspase 6; Caspase 9; Cell Death; Cell Line; Dermatologic Agents; Dexamethasone; Dimethyl Fumarate; Etoposide; Fumarates; Humans; Interleukin-8; Maleates; Mast Cells; Methotrexate; Psoriasis; TNF-Related Apoptosis-Inducing Ligand

Density functional theory (DFT) calculations at B3LYP/6-31 G (d,p) and B3LYP/6-311+G(d,p) levels for the substituted pyridine-catalyzed isomerization of monomethyl maleate revealed that isomerization proceeds via four steps, with the rate-limiting step being proton transfer from the substituted pyridinium ion to the C=C double bond in INT1. In addition, it was found that the isomerization rate (maleate to fumarate) is solvent dependent. Polar solvents, such as water, tend to accelerate the isomerization rate, whereas apolar solvents, such as chloroform, act to slow down the reaction. A linear correlation was obtained between the isomerization activation energy and the dielectric constant of the solvent. Furthermore, linearity was achieved when the activation energy was plotted against the pKa value of the catalyst. Substituted-pyridine derivatives with high pKa values were able to catalyze isomerization more efficiently than those with low pKa values. The calculated relative rates for prodrugs 1-6 were: 1 (406.7), 2 (7.6×10(6)), 3 (1.0), 4 (20.7), 5 (13.5) and 6 (2.2×10(3)). This result indicates that isomerizations of prodrugs 1 and 3-5 are expected to be slow and that of prodrugs 2 and 6 are expected to be relatively fast. Hence, prodrugs 2 and 3-5 have the potential to be utilized as prodrugs for the slow release of monomethylfumarate in the treatment of psoriasis and multiple sclerosis.

Topics: Catalysis; Computer Simulation; Fumarates; Humans; Isomerism; Kinetics; Maleates; Models, Molecular; Multiple Sclerosis; Prodrugs; Psoriasis; Pyridines; Quantum Theory; Solvents; Thermodynamics

Fumaric acid esters are used to treat psoriasis, an inflammatory skin disease characterized by keratinocyte proliferation. Inflammation and proliferation are hallmarks of retinal disease; hence, fumaric acid esters may have therapeutic value in retinal pathology. In diseased retinas, Müller glial cells (MCs) undergo reactive gliosis, a hyperproliferative state. MCs take up folate, a vitamin necessary for cell proliferation, via the proton-coupled folate transporter (PCFT). Here we examined the effect of monomethylfumarate (MMF), the active metabolite of fumaric acid esters, on expression and function of PCFT in MCs. Primary MCs, isolated from neonatal mouse retinas, were treated with MMF, and PCFT function was monitored by measuring uptake of radiolabeled methyltetrahydrofolate (MTF) at pH 5.5. Dose-response and time-course analyses were performed to identify optimal conditions for maximal effect. The influence of MMF treatment on kinetic parameters of PCFT was studied, and PCFT expression was analyzed at the mRNA and protein level. MTF uptake in MCs decreased by ˜50% following 18 h treatment with 1 mM MMF. This effect was specific to fumaric acid esters. MMF treatment decreased the maximal velocity of the transporter without altering substrate affinity. The decrease in PCFT function following MMF treatment was accompanied by attenuated PCFT expression. This is the first report that an antipsoriatic compound can regulate folate transport in MCs and may have potential for the treatment of reactive gliosis in retinal disease.

Topics: Analysis of Variance; Animals; Animals, Newborn; Antipsychotic Agents; Dermatologic Agents; Dose-Response Relationship, Drug; Folate Receptor 1; Fumarates; Gene Expression Regulation; Maleates; Mice; Mice, Inbred C57BL; Neuroglia; Niacin; Proton-Coupled Folate Transporter; Receptors, G-Protein-Coupled; Receptors, Nicotinic; Retina; RNA, Messenger; Time Factors; Tritium; Vasodilator Agents

Access to novel ecological niches often requires adaptation of metabolic pathways to cope with new environments. For conversion to cellular building blocks, many substrates enter central carbon metabolism via acetyl-coenzyme A (acetyl-CoA). Until now, only two such pathways have been identified: the glyoxylate cycle and the ethylmalonyl-CoA pathway. Prokaryotes in the haloarchaea use a third pathway by which acetyl-CoA is oxidized to glyoxylate via the key intermediate methylaspartate. Glyoxylate condensation with another acetyl-CoA molecule yields malate, the final assimilation product. This cycle combines reactions that originally belonged to different metabolic processes in different groups of prokaryotes, which suggests lateral gene transfer and evolutionary tinkering of acetate assimilation. Moreover, it requires elevated intracellular glutamate concentrations, as well as coupling carbon assimilation with nitrogen metabolism.

Topics: Acetates; Acetyl Coenzyme A; Archaeal Proteins; Fumarates; Gene Transfer, Horizontal; Genes, Archaeal; Glutamic Acid; Glyoxylates; Haloarcula marismortui; Malates; Maleates; Metabolic Networks and Pathways; N-Methylaspartate; Oxidation-Reduction; Proteome; Succinic Acid

We report a case of a patient with a rapidly progressive dementing illness and gait disturbance, in whom initial screening demonstrated a high methylmalonic acid level only, suggestive of a functional vitamin B(12) deficiency. Despite B(12) replacement therapy, he continued to decline. Further investigations demonstrated extensive signal change on magnetic resonance imaging involving grey and white matter within the corpus callosum, deep grey matter, brainstem and cerebellar peduncles, and patchy post-contrast enhancement. Laboratory testing revealed a raised erythrocyte sedimentation rate, raised anti-nuclear, intrinsic factor and lupus anticoagulant antibody titres, and a IgG kappa paraprotein. Cerebrospinal fluid was unremarkable. Bone marrow trephine biopsy showed monoclonal gammopathy of unknown significance. The patient initially responded to steroids, and underwent a brain biopsy, which was uninformative. However, 3 weeks following admission, he died due to an aspiration pneumonia. Autopsy findings were consistent with a diffuse primary central nervous system small cell B-cell lymphoma. This has been rarely reported in the medical literature, but our case exhibits typical clinical features, although patchy enhancement on imaging and the high methylmalonic acid have not been previously described. We hypothesise that his functional B(12) deficiency may have resulted from rapid cell turnover, perhaps in conjunction with the presence of intrinsic factor antibodies.

Topics: Aged; Brain Neoplasms; Dementia; Fatal Outcome; Fumarates; Humans; Lymphoma, B-Cell; Magnetic Resonance Imaging; Male; Maleates

The present study was performed to investigate the effects of dimethylfumarate (DMF) and methylhydrogen fumarate (MHF) on the cytokine pattern of peripheral blood mononuclear cells (PBMCs) of multiple sclerosis (MS) patients. The PBMCs from patients and healthy controls were stimulated with myelin basic protein (MBP) or phytohemagglutinin (PHA) and cultured in the presence of DMF and MHF. The percentage of CD4+IL-4+ and CD4+IFN-γ+ cells was determined by means of intracellular cytokine staining. CD4+IL-4+ cells were significantly increased in the presence of DMF and MHF when PBMCs were stimulated by MBP (P < 0.003). The same significant result was obtained by PHA stimulation (P < 0.049). In terms of CD4+IFN-γ+ cells, the percentage of cells did not significantly differ between the cultures stimulated with MBP or PHA in the presence and absence of the drugs. Results of MBP stimulation in control group also showed a significant increase in CD4+IL-4+ cells in the presence of DMF and MHF. In comparison between patient and control groups, no statistically significant changes were observed. In conclusion, both DMF and MHF effectively increased IL-4 production, whereas they did not significantly change IFN-γ level, indicating the role of these drugs in increasing the production of beneficial cytokines such as IL-4.

Topics: Adolescent; Adult; CD4-Positive T-Lymphocytes; Cell Count; Cell Survival; Cytokines; Dimethyl Fumarate; Female; Fumarates; Humans; Interferon-gamma; Interleukin-4; Leukocytes, Mononuclear; Lymphocyte Activation; Lymphocytes; Male; Maleates; Middle Aged; Multiple Sclerosis; Myelin Basic Protein; Phytohemagglutinins; Th1 Cells; Th2 Cells; Young Adult

Methylmalonic aciduria (MMA) is a common inherited autosomal recessive disorder resulting from defects in the enzyme methylmalonyl CoA mutase (MCM, mut complementation group) or in the synthesis of the MCM cofactor adenosylcobalamin (cbl complementation groups). The defects in the mut complementation group accounts for the largest number of patients with isolated MMA. At least 200 mutations in the MUT gene on chromosome 6p12 have been identified in MMA patients until now. This study aimed to investigate the clinical characteristics of MMA and genomic variations in the MUT gene of Chinese patients. Genomic DNA was extracted from 18 patients who were diagnosed as having isolated MMA by gas chromatography/mass spectrometry (GC-MS), and from some of their parents as well. Amplification and direct sequencing of the MUT coding regions (exon 2-13) and their adjacent intronic consensus splice sites were performed in order to identify the disease causing mutations. In this group, six novel mutations in the MUT gene, c.424A>G (p.T142A), c.786T>G (p.S262R), c.808G>C (p.G270R), c.1323_1324insA, c.1445-1G>A and c.1676+77A>C were identified. p.T142A and p.G270R were respectively detected at a heterozygous level in one patient. Two previously reported mutations, c.682C>T (p.R228X) and c.323G>A (p.R108H) were also found in this study. In addition, six previously described single nucleotide polymorphism (SNP), c.636A>G (p.K212K), c.1495G>A (p.A499T), c.1595A>G (p.H532R), c.1992G>A (p.A664A), c.2011G>A (p.V671I) and c.1677-53A>G were identified. In this study, we updated the spectrum of MUT mutations and identified the main MMA-causing mutations in Chinese MMA patients.

Topics: Asian People; Base Sequence; Child, Preschool; DNA Mutational Analysis; Female; Fumarates; Genotype; Humans; Infant; Infant, Newborn; Male; Maleates; Metabolism, Inborn Errors; Methylmalonyl-CoA Mutase; Molecular Sequence Data; Mutation; Polymorphism, Genetic

To investigate the interrelations of serum vitamin B12 markers with brain volumes, cerebral infarcts, and performance in different cognitive domains in a biracial population sample cross-sectionally.. In 121 community-dwelling participants of the Chicago Health and Aging Project, serum markers of vitamin B12 status were related to summary measures of neuropsychological tests of 5 cognitive domains and brain MRI measures obtained on average 4.6 years later among 121 older adults.. Concentrations of all vitamin B12-related markers, but not serum vitamin B12 itself, were associated with global cognitive function and with total brain volume. Methylmalonate levels were associated with poorer episodic memory and perceptual speed, and cystathionine and 2-methylcitrate with poorer episodic and semantic memory. Homocysteine concentrations were associated with decreased total brain volume. The homocysteine-global cognition effect was modified and no longer statistically significant with adjustment for white matter volume or cerebral infarcts. The methylmalonate-global cognition effect was modified and no longer significant with adjustment for total brain volume.. Methylmalonate, a specific marker of B12 deficiency, may affect cognition by reducing total brain volume whereas the effect of homocysteine (nonspecific to vitamin B12 deficiency) on cognitive performance may be mediated through increased white matter hyperintensity and cerebral infarcts. Vitamin B12 status may affect the brain through multiple mechanisms.

Topics: Aged; Aged, 80 and over; Brain; Brain Infarction; Chicago; Cognition; Cohort Studies; Cross-Sectional Studies; Female; Fumarates; Humans; Magnetic Resonance Imaging; Male; Maleates; Neuropsychological Tests; Residence Characteristics; Retrospective Studies; Vitamin B 12

Although fumaric acid esters (FAE) have a decade-long firm place in the therapeutic armamentarium for psoriasis, their pleiotropic mode of action is not yet fully understood. While most previous studies have focused on the effects of FAE on leucocytes, we have addressed their activity on macro- and microvascular endothelial cells. As detected both on mRNA and protein levels, dimethylfumarate effected a profound reduction of TNFα-induced expression of E-selectin (CD62E), ICAM-1 (CD54) and VCAM-1 (CD106) on two different endothelial cell populations in a concentration-dependent manner. This reduction of several endothelial adhesion molecules was accompanied by a dramatic diminution of both rolling and firm adhesive interactions between endothelial cells and lymphocytes in a dynamic flow chamber system. Dimethylfumarate, at a concentration of 50 μm, reduced lymphocyte rolling on endothelial cells by 85.9% (P<0.001 compared to untreated controls), and it diminished the number of adherent cells by 88% (P<0.001). In contrast, monomethylfumarate (MMF) influenced neither surface expression of adhesion molecules nor interactions between endothelial cells and lymphocytes. These observations demonstrate that endothelial cells, in addition to the known effects on leucocytes, undergo profound functional changes in response to dimethylfumarate. These changes are accompanied by severely impaired dynamic interactions with lymphocytes, which constitute the critical initial step of leucocyte recruitment to inflamed tissues in psoriasis and other TNF-related inflammatory disorders.

Topics: Cell Adhesion; Cell Adhesion Molecules; Cell Line, Transformed; Cell Membrane; Dimethyl Fumarate; Down-Regulation; E-Selectin; Endothelial Cells; Fumarates; Gene Expression; Human Umbilical Vein Endothelial Cells; Humans; Intercellular Adhesion Molecule-1; Leukocyte Rolling; Lymphocytes; Maleates; Tumor Necrosis Factor-alpha; Vascular Cell Adhesion Molecule-1; Vascular Endothelial Growth Factor A

Methylmenaquinol : fumarate reductase (Mfr) is a newly recognized type of fumarate reductase present in some epsilon-proteobacteria, where the active site subunit (MfrA) is localized in the periplasm, but for which a physiological role has not been identified. We show that the Campylobacter jejuni mfrABE operon is transcribed from a single promoter, with the mfrA gene preceded by a small open reading-frame (mfrX) encoding a C. jejuni-specific polypeptide of unknown function. The growth characteristics and enzyme activities of mutants in the mfrA and menaquinol : fumarate reductase A (frdA) genes show that the cytoplasmic facing Frd enzyme is the major fumarate reductase under oxygen limitation. The Mfr enzyme is shown to be necessary for maximal rates of growth by fumarate respiration and rates of fumarate reduction in intact cells measured by both viologen assays and 1H-NMR were slower in an mfrA mutant. As periplasmic fumarate reduction does not require fumarate/succinate antiport, Mfr may allow more efficient adaptation to fumarate-dependent growth. However, a further rationale for the periplasmic location of Mfr is suggested by the observation that the enzyme also reduces the fumarate analogues mesaconate and crotonate; fermentation products of anaerobes with which C. jejuni shares its gut environment, that are unable to be transported into the cell. Both MfrA and MfrB subunits were localized in the periplasm by immunoblotting and 2D-gel electrophoresis, but an mfrE mutant accumulated unprocessed MfrA in the cytoplasm, suggesting a preassembled MfrABE holoenzyme has to be recognized by the TAT system for translocation to occur. Gene expression studies in chemostat cultures following an aerobic-anaerobic shift showed that mfrA is highly upregulated by oxygen limitation, as would be experienced in vivo. Our results indicate that in addition to a role in fumarate respiration, Mfr allows C. jejuni to reduce analogous substrates specifically present in the host gut environment.

Topics: Amino Acid Sequence; Animals; Bacterial Proteins; Base Sequence; Campylobacter jejuni; Crotonates; Fumarates; Gene Expression Regulation, Bacterial; Humans; Maleates; Molecular Sequence Data; Operon; Oxidation-Reduction; Oxygen; Periplasm; Protein Subunits; Succinate Dehydrogenase

The aim of this study was to evaluate pharmacokinetic parameters of fumaric acid esters (FAE) in psoriasis patients for the first time. For this prupose new HPLC assays were developed. Additionally, physicochemical parameters of FAE were determined, allowing a better interpretation of the in vivo data. In vivo, monomethylfumarate (MMF) and monoethylfumarate (MEF) were detected after t (lag) = 120 min. T (max) and c (max) of MMF were 210 min and 11.2 microM, respectively, 210 min and 5.2 microM for MEF. The half-life of MMF was 38.7 min, and 25.4 min of MEF. The AUC(0-infinity) of MMF was 172 min microg ml(-1) and 63.6 min microg ml(-1) of MEF. Data display median of three subjects. No plasma levels of dimethylfumarate (DMF) or fumaric acid (FA) were detected. The evaluation of physicochemical parameters of FAE showed that only DMF fulfils the criteria of Lipinski's rule of five. The pKa of MMF was determined as 3.63. The data of this study provide evidence that DMF is most likely absorbed out of the duodenum into the presystemic circulation and is not completely hydrolysed to MMF before uptake as assumed by others.

Topics: Adult; Duodenum; Fumarates; Half-Life; Humans; Hydrolysis; Male; Maleates; Middle Aged; Psoriasis

The organotin monomer di(tri-n-butyltin) citraconate (DTBTC, I) was synthesized. Subsequently this monomer was copolymerized with N-vinylimidazole (VI) using a free radical technique. The overall conversion was kept low (< or = 14% wt/wt) for all studied samples and the copolymer composition was determined from tin analysis using the Gilman and Rosenberg method. The synthesized monomer and copolymer were further characterized by elemental analysis, (1)H- and (13)C-NMR, and FTIR spectroscopy.

Topics: Fumarates; Imidazoles; Maleates; Polymers; Trialkyltin Compounds

Fumaric acid esters (FAE) are a group of compounds which are currently under investigation as an oral treatment for relapsing-remitting multiple sclerosis. One of the suggested modes of action is the potential of FAE to exert a neuroprotective effect.. We have investigated the impact of monomethylfumarate (MMF) and dimethylfumaric acid (DMF) on de- and remyelination using the toxic cuprizone model where the blood-brain-barrier remains intact and only scattered T-cells and peripheral macrophages are found in the central nervous system (CNS), thus excluding the influence of immunomodulatory effects on peripheral immune cells. FAE showed marginally accelerated remyelination in the corpus callosum compared to controls. However, we found no differences for demyelination and glial reactions in vivo and no cytoprotective effect on oligodendroglial cells in vitro. In contrast, DMF had a significant inhibitory effect on lipopolysaccharide (LPS) induced nitric oxide burst in microglia and induced apoptosis in peripheral blood mononuclear cells (PBMC).. These results contribute to the understanding of the mechanism of action of fumaric acids. Our data suggest that fumarates have no or only little direct protective effects on oligodendrocytes in this toxic model and may act rather indirectly via the modulation of immune cells.

Topics: Animals; Apoptosis; Cells, Cultured; Central Nervous System; Cuprizone; Demyelinating Diseases; Dimethyl Fumarate; Fumarates; Immunohistochemistry; Leukocytes, Mononuclear; Male; Maleates; Mice; Mice, Inbred C57BL; Rats; Rats, Sprague-Dawley

To investigate urinary methylmalonic acid (uMMA) levels and their relationship with markers of myocyte necrosis and inflammation in patients with acute myocardial infarction (AMI).. The study participants consisted of 80 consecutive patients with AMI and 72 age- and sex-matched consecutive controls. Of the patients, 38 had ST segment elevation myocardial infarction (STEMI) and 42 had non-ST segment elevation. All patients with STEMI underwent fibrinolytic therapy. Routine laboratory tests included troponin-I, creatinine phosphokinase MB (CK-MB), high-sensitivity C-reactive protein (hs-CRP), vitamin B(12), folate, homocysteine and methylmalonic acid analyses. uMMA measurements were made by a spectrophotometric method.. uMMA levels were significantly higher in patients with AMI than in controls (10.1 vs. 5.2 mmol/mol creatinine, p < 0.001) and higher in patients with anterior MI compared to those with non-anterior MI (18.9 vs. 8.7 mmol/mol creatinine, p < 0.001). In addition, uMMA levels were significantly higher in patients without successful reperfusion compared to those with successful reperfusion. In patients with STEMI, a strong positive association was found between urinary MMA and plasma hs-CRP levels (r = 0.81, p < 0.001), symptom duration (r = 0.91, p < 0.001) and wall motion score (r = 0.60, p = 0.006). More importantly, a strong positive association was observed between uMMA and the size of myocardial infarction in patients without successful reperfusion (for CK-MB r = 0.81, p = 0.013; for wall motion score r = 0.82, p = 0.012).. uMMA levels were elevated in patients with AMI and, as such, may be a candidate biochemical indicator of larger infarct size and enhanced inflammation in patients with AMI.

Topics: Adult; Aged; Aged, 80 and over; Biomarkers; Case-Control Studies; Echocardiography; Electrocardiography; Female; Fibrinolytic Agents; Fumarates; Humans; Male; Maleates; Middle Aged; Myocardial Infarction; Severity of Illness Index; Spectrophotometry; Vitamin B 12

Deuterium-labelled compounds were prepared by (transfer) deuterogenation of unsaturated compounds using H(2) or HCO(2)H in acidic D(2)O as deuterium source with almost quantitative yields and high deuterium contents under mild reaction conditions via heterolytic cleavage of H(2) (or decomposition of HCO(2)H) and rapid H(+)/D(+) exchange using iridium catalysts with 4,4'-dihydroxy-2,2'-bipyridine.

Topics: 2,2'-Dipyridyl; Catalysis; Deuterium; Deuterium Oxide; Formates; Fumarates; Hydrogen; Iridium; Maleates; Succinates

Nicotinic acid has been used for several decades to treat dyslipidemia. In mice, the lipid-lowing effect of nicotinic acid is mediated by the Gi coupled receptor PUMA-G. In humans, high (GPR109A) and low (GPR109B) affinity nicotinic acid receptors have been characterized. Here we identify monomethylfumarate as a GPR109A agonist. Monomethylfumarate is the active metabolite of the psoriasis drug Fumaderm. We show that monomethylfumarate activates GPR109A in a calcium based aequorin assay, cAMP assay and demonstrate competitive binding with nicotinic acid. We show that GPR109A is highly expressed in neutrophils and epidermal keratinocytes, and that its expression is increased in human psoriatic lesions. Our findings provide evidence that GPR109A is a target for the drug Fumaderm and suggest that niacin should be investigated to treat psoriasis in addition to its role in treating lipid disorders.

Topics: Cell Line; Dermatologic Agents; Dimethyl Fumarate; Fumarates; Humans; Hypolipidemic Agents; Maleates; Niacin; Psoriasis; Receptors, G-Protein-Coupled; Receptors, Nicotinic

Immunohistochemical staining of tissues is a powerful tool used to delineate the presence or absence of an antigen. During the last 30 years, antigen visualization in human brain tissue has been significantly limited by the masking effect of fixatives. In the present study, we have used a new method for antigen retrieval in formalin-fixed human brain tissue and examined the effectiveness of this protocol to reveal masked antigens in tissues with both short and long formalin fixation times. This new method, which is based on the use of citraconic acid, has not been previously utilized in brain tissue although it has been employed in various other tissues such as tonsil, ovary, skin, lymph node, stomach, breast, colon, lung and thymus. Thus, we reported here a novel method to carry out immunohistochemical studies in free-floating human brain sections. Since fixation of brain tissue specimens in formaldehyde is a commonly method used in brain banks, this new antigen retrieval method could facilitate immunohistochemical studies of brains with prolonged formalin fixation times.

Topics: Antigens; Brain Chemistry; Female; Fixatives; Formaldehyde; Fumarates; Humans; Immunohistochemistry; Male; Maleates; Methods; Tissue Fixation

Fumaric acid esters (FAE) are effective against psoriasis vulgaris and monomethylfumarate (MMF) is believed to be the most bioactive metabolite of this medication. Earlier we found that the beneficial effects of FAE medication are accompanied by a downregulation of type 1 cytokine production by T-helper (Th) lymphocytes, which are important as they maintain a type 1 cytokine [interferon (IFN)-gamma, interleukin (IL)-2] environment in the skin lesions of psoriasis vulgaris patients and once maximal beneficial effects are obtained type 2 cytokine production is also decreased. In vitro MMF selectively induced type 2 cytokine production by primed Th lymphocytes, whereas type 1 cytokine production by and profileration of T lymphocytes were unaffected.. As dendritic cells (DCs) present in these skin lesions play a key role in the activation of Th lymphocytes, we investigated the effects of MMF on monocyte-derived DC differentiation.. Monocytes were differentiated into immature (i) DCs by cytokines with or without MMF. To establish whether these cells were differentiated into iDCs, we analysed the expression of cell surface molecules on these cells and the capacity to capture antigens using flow cytometry. Next, we determined whether these MMF-incubated (MMF-)iDCs could be matured by lipopolysaccharide (LPS) and whether MMF affected this responsiveness as well. For this purpose we measured cytokine production by these LPS-stimulated cells (MMF-DCs) using enzyme-linked immunosorbent assays as well as their ability to activate naive Th lymphocytes.. The presence of MMF during the differentiation of monocytes into iDCs resulted in cells that retained low levels of CD14 and hardly expressed CD1a. Upon maturation, these MMF-iDCs upregulated CD83 and costimulatory molecules and HLA-DR on their surface, indicating that these cells respond to LPS, albeit less than control iDCs. In addition, in response to LPS, MMF-iDCs did not decrease the capacity to capture antigens when compared with control iDCs. MMF-DCs hardly produced IL-12p70 and IL-10 and low levels of tumour necrosis factor (TNF)-alpha, whereas IL-8 produced by MMF-DCs and control DCs did not differ. Moreover, MMF-DCs were less able to induce IFN-gamma production by naive Th lymphocytes compared with control DCs. The production of IL-4 and IL-10 by naive Th lymphocytes cocultured with MMF-DCs did not differ from that by T cells cocultured with control DCs.. MMF inhibited the monocyte-derived DC differentiation resulting in cells that cannot be appropriately matured to DCs. Consequently, these MMF-DCs are less effective than control DCs in stimulating type 1 cytokine, but not type 2 cytokine production, in Th lymphocytes. This general immunomodulatory effect may in part explain the beneficial effects of FAE therapy in psoriasis.

Topics: Antigens, Surface; Cell Differentiation; Cells, Cultured; Cytokines; Dendritic Cells; Dermatologic Agents; Endocytosis; Fumarates; Humans; Lipopolysaccharide Receptors; Lipopolysaccharides; Lymphocyte Activation; Maleates; Monocytes; T-Lymphocytes, Helper-Inducer

The soluble fumarate reductase (FR) from Shewanella frigidimarina can catalyse the reduction of 2-methylfumarate with a k(cat) of 9.0 s(-1) and a K(M) of 32 microM. This produces the chiral molecule 2-methylsuccinate. Here, we present the structure of FR to a resolution of 1.5 A with 2-methylfumarate bound at the active site. The mode of binding of 2-methylfumarate allows us to predict the stereochemistry of the product as (S)-2-methylsuccinate. To test this prediction we have analysed the product stereochemistry by circular dichroism spectroscopy and confirmed the production of (S)-2-methylsuccinate.

Topics: Catalysis; Circular Dichroism; Crystallography; Fumarates; Maleates; Oxidation-Reduction; Protein Conformation; Shewanella; Succinate Dehydrogenase; Succinates

The patients affected by vitamin B12-unresponsive methylmalonic acidemia (MMA) on the long run develop chronic renal disease with interstitial nephropathy and progressive renal insufficiency. The mechanism of nephrotoxicity in vitamin B12-unresponsive MMA is not yet known. Chronic hyporeninemic hypoaldosteronism has been found in many cases of methylmalonic acidemia, hyperkalemia and renal tubular acidosis type 4. We report 2 patients affected by B12-unresponsive methylmalonic acidemia diagnosed at the age of 23 months and 5 years, respectively, with normal glomerular filtration and function. They showed hyporeninemic hypoaldosteronism and significant hyperkalemia requiring sodium potassium exchange resin (Kayexalate) therapy after an episode of metabolic decompensation leading to diagnosis of MMA. In both children, hyporeninemic hypoaldosteronism and hyperkalemia disappeared after 6 months of good metabolic control.

Topics: Child, Preschool; Female; Fumarates; Humans; Hyperkalemia; Hypoaldosteronism; Infant; Kidney; Male; Maleates; Metabolism, Inborn Errors; Vitamin B 12

Formalin is a commonly used fixative for tissue preservation in pathology laboratories. A major adverse effect of this fixative is the concealing of tissue antigens by protein cross-linking. To achieve a universal antigen retrieval method for immunohistochemistry under a constant condition, we developed a new method in which the effects of formalin fixation were reversed with citraconic anhydride (a reversible protein cross-linking agent) plus heating. Formalin-fixed, paraffin-embedded tissues from various organs were examined for immunohistochemical localization of a wide variety of antigens. Deparaffinized tissue sections were placed in an electric kitchen pot containing 0.05% citraconic anhydride solution, pH 7.4, and the pot was set at "keep warm" temperature mode of 98C for 45 min. This mode allowed heating the sections at a constant temperature. The sections were then washed in buffer solution and immunostained using a labeled streptavidin-biotin method using an automated stainer. In general, formalin-fixed tissues demonstrated specific immunostainings comparable to that in fresh frozen tissues and significantly more enhanced than after conventional antigen retrieval methods. In particular, even difficult-to-detect antigens such as CD4, cyclin D1, granzyme beta, bcl-6, CD25, and lambda chain revealed distinct immunostainings. Different classes of antigens such as cellular markers and receptors, as well as cytoplasmic and nuclear proteins, consistently produced enhanced reactions. This method provides efficient antigen retrieval for successful immunostaining of a wide variety of antigens under an optimized condition. It also allows standardization of immunohistochemistry for formalin-fixed tissues in pathology laboratories, eliminating inter-laboratory discrepancies in results for accurate clinical and research studies.

Topics: Antigens; Cross-Linking Reagents; Fixatives; Formaldehyde; Fumarates; Heating; Humans; Immunohistochemistry; Maleates; Paraffin Embedding; Tissue Fixation

Psoriasis vulgaris, a type-1 cytokine-mediated chronic skin disease, can be treated successfully with fumaric acid esters (FAE). Beneficial effects of this medication coincided with decreased production of IFN-gamma. Since dendritic cells (DC) regulate the differentiation of T helper (Th) cells, this study focussed on effects of monomethylfumarate (MMF, bioactive metabolite of FAE) on polarization of monocyte-derived DC. MMF-incubated, lipo-polysaccharide-stimulated DC (MMF-DC) produced dramatically (p<0.05) reduced levels of IL-12p70 and IL-10 (8+/-4% and 20+/-4%, respectively) compared to control DC. MMF-DC were mature. MMF affected polarization of DC irrespective of polarization factor(s) and ligands for the various Toll-like receptors used. Coculture of MMF-DC with naive and primed allogenous Th cells resulted in lymphocytes producing less IFN-gamma, i.e. 59% and 54% of that by the respective Th cells cocultured with control DC. IL-4 production by primed, but not naive Th cells cocultured with MMF-DC was decreased as compared to cocultures with control DC. IL-10 production by naive and primed Th cells cocultured with MMF-DC and control DC did not differ. In addition, MMF inhibited LPS-induced NF-kappaB activation in DC. Together, beneficial effects of FAE in psoriasis involve modulation of DC polarization by MMF such that these cells down-regulate IFN-gamma production by Th cells.

Topics: Antigens, CD; Cell Differentiation; Cell Polarity; Coculture Techniques; Dendritic Cells; Down-Regulation; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Fumarates; Humans; Interleukin-10; Interleukin-12; Interleukin-8; Lymphocyte Activation; Maleates; Monocytes; Protein Subunits; Psoriasis; Th1 Cells; Tumor Necrosis Factor-alpha

Psoriasis is a chronic inflammatory skin disease that can be successfully treated with a mixture of fumaric acid esters (FAE) formulated as enteric-coated tablets for oral use. These tablets consist of dimethylfumarate (DMF) and salts of monoethylfumarate (MEF) and its main bioactive metabolite is monomethylfumarate (MMF). Little is known about the pharmacokinetics of these FAE. The aim of the present study was to investigate the hydrolysis of DMF to MMF and the stability of MMF, DMF and MEF at in vitro conditions representing different body compartments.. DMF is hydrolyzed to MMF in an alkaline environment (pH 8), but not in an acidic environment (pH 1). In these conditions MMF and MEF remained intact during the period of analysis (6 h). Interestingly, DMF was hardly hydrolyzed to MMF in a buffer of pH 7.4, but was rapidly hydrolyzed in human serum having the same pH. Moreover, in whole blood the half-life of DMF was dramatically reduced as compared to serum. The concentrations of MMF and MEF in serum and whole blood decreased with increasing time. These data indicate that the majority of the FAE in the circulation are metabolized by one or more types of blood cells. Additional experiments with purified blood cell fractions resuspended in phosphate buffered saline (pH 7.4) revealed that at concentrations present in whole blood monocytes/lymphocytes, but not granulocytes and erythrocytes, effectively hydrolyzed DMF to MMF. Furthermore, in agreement with the data obtained with the pure components of the tablet, the enteric-coated tablet remained intact at pH 1, but rapidly dissolved at pH 8.. Together, these in vitro data indicate that hydrolysis of DMF to MMF rapidly occurs at pH 8, resembling that within the small intestines, but not at pH 1 resembling the pH in the stomach. At both pHs MMF and MEF remained intact. These data explain the observation that after oral FAE intake MMF and MEF, but not DMF, can be readily detected in the circulation of human healthy volunteers and psoriasis patients.

Topics: Blood Cells; Buffers; Dermatologic Agents; Dimethyl Fumarate; Drug Stability; Esters; Fumarates; Half-Life; Humans; Hydrogen-Ion Concentration; Hydrolysis; In Vitro Techniques; Intestine, Small; Maleates; Psoriasis; Serum; Stomach

A series of fumarate analogues has been used to explore the molecular mechanism of the activation of dopamine beta-mono-oxygenase by fumarate. Mesaconic acid (MA) and trans -glutaconic acid (TGA) both activate the enzyme at low concentrations, similar to fumarate. However, unlike fumarate, TGA and MA interact effectively with the oxidized enzyme to inhibit it at concentrations of 1-5 mM. Monoethylfumarate (EFum) does not activate the enzyme, but inhibits it. In contrast with TGA and MA, however, EFum inhibits the enzyme by interacting with the reduced form. The saturated dicarboxylic acid analogues, the geometric isomer and the diamide of fumaric acid do not either activate or inhibit the enzyme. The phenylethylamine-fumarate conjugate, N -(2-phenylethyl)fumaramide (PEA-Fum), is an approximately 600-fold more potent inhibitor than EFum and behaves as a bi-substrate inhibitor for the reduced enzyme. The amide of PEA-Fum behaves similarly, but with an inhibition potency approximately 20-fold less than that of PEA-Fum. The phenylethylamine conjugates of saturated or geometric isomers of fumarate do not inhibit the enzyme. Based on these findings and on steady-state kinetic analysis, an electrostatic model involving an interaction between the amine group of the enzyme-bound substrate and a carboxylate group of fumarate is proposed to account for enzyme activation by fumarate. Furthermore, in light of the recently proposed model for the similar copper enzyme, peptidylglycine alpha-hydroxylating mono-oxygenase, the above electrostatic model suggests that fumarate may also play a role in efficient electron transfer between the active-site copper centres of dopamine beta-mono-oxygenase.

Topics: Amides; Animals; Ascorbic Acid; Binding Sites; Cattle; Dopamine beta-Hydroxylase; Dose-Response Relationship, Drug; Electron Transport; Enzyme Activation; Fumarates; Glutarates; Kinetics; Maleates; Models, Chemical; Models, Molecular; Oxygen; Phenethylamines; Spectrophotometry; Tyramine

Monomethyl fumarate, isolated for the first time from the methanolic extract of the whole plant of Fumaria indica, was characterised and screened for its antihepatotoxic activity in albino rats. The compound showed significant (P < 0.01) antihepatotoxic activity against thioacetamide in vitro, and against hepatotoxicities induced by carbon tetrachloride, paracetamol and rifampicin in vivo to an extent almost similar to that of silymarin, a known antihepatotoxic agent.

Topics: Acetaminophen; Alanine Transaminase; Alkaline Phosphatase; Animals; Aspartate Aminotransferases; Bilirubin; Carbon Tetrachloride; Chemical and Drug Induced Liver Injury; Female; Fumarates; Galactosamine; Liver; Male; Maleates; Plant Extracts; Rats; Rats, Wistar; Rifampin; Silymarin; Thioacetamide

Preparative affinity chromatography of bovine serum amine oxidase (SAO) on aminohexyl (AH)-Sepharose was often associated with an unexpected irreversible SAO retention on the support. This particular enzyme immobilization, occurring without coupling reagents, was supposed to be due to a SAO ability to: (i) recognize alkylamine groups of the support as macro-molecularized substrate; (ii) catalyse their oxidation to the corresponding aldehydes, with release of NH3 and H2O2; and (iii) be immobilized on the activated support by a coupling between the nascent aldehyde groups and SAO free amine groups. This affinity immobilization procedure, with the self-activation of the support, being mild, allows by simple incubation for 24 h, the enzyme immobilization with the retention of 80% from original specific activity of free SAO. Immobilized SAO on AH-Sepharose microcolumns, viewed as a continuous flow-system reactor, was able to catalyse benzylamine oxidation for several weeks.

Topics: Amine Oxidase (Copper-Containing); Animals; Benzylamines; Cattle; Chromatography, Affinity; Enzymes, Immobilized; Fumarates; Hydrogen Peroxide; Isoelectric Focusing; Maleates; Oxidation-Reduction; Oxidoreductases Acting on CH-NH Group Donors; Peptides; Sepharose; Time Factors

Monomethylfumarate (MMF), the most active metabolite of the new antipsoriasis drug Fumaderm, stimulates an anti-inflammatory mediator profile in human leucocytes and inhibits the proliferation of keratinocytes. These effects of MMF on cells in vitro may in part explain the beneficial action of Fumaderm in patients. In addition, we have reported that MMF stimulates an increase in the intracellular free Ca2+ concentration ([Ca2+]i) and the cyclic adenosine monophosphate (cAMP) concentration in granulocytes and keratinocytes. Because Ca2+ and cAMP control many physiological cellular responses, including cell proliferation and inflammatory mediator production, the present study focused on the intracellular signal transduction pathway which links interaction between MMF and granulocytes with increases in [Ca2+]i and the cAMP concentration. The increase in [Ca2+]i in granulocytes after MMF depended both on extracellular Ca2+ and Ca2+ from intracellular stores. Ca2+ is essential for the increase in the cAMP concentration after stimulation with MMF. The results found for pharmacological inhibitors of various protein kinases suggest that a staurosporine-sensitive protein kinase different from protein kinase C (PKC) and protein kinase A is involved in the MMF-induced increase in [Ca2+]i in granulocytes. As MMF activated protein tyrosine kinase (PTK), and inhibition of this protein kinase partially reduced the increase in [Ca2+]i in granulocytes, PTK activity most likely is involved. In addition, activation of protein kinase histone 4 (PKH4) probably plays a part in the MMF-stimulated increase in [Ca2+]i in granulocytes as well. As MMF stimulated an increase in the GTP-ase activity of membranes and pertussis toxin (PTX) inhibited the increase in the [Ca2+]i and PKH4 activity of granulocytes stimulated by this compound, it is concluded that MMF activates PTX-sensitive G proteins. Competition binding studies with radiolabelled dimethylfumarate (DMF) and unlabelled DMF and MMF revealed the presence of specific binding sites for methylated fumarates on granulocytes. In summary, MMF binds to specific sites on the plasma membrane of cells. This interaction activates pertussis toxin-sensitive G proteins which then stimulate an increase in PTK and PKH4 activity. These protein kinases may regulate the rise in [Ca2+]i and the intracellular cAMP concentration. Elevated [Ca2+]i and intracellular cAMP concentration stimulate protein kinases that regulate transcription factors. A

Topics: Binding Sites; Binding, Competitive; Calcium; Cell Membrane; Cells, Cultured; Cyclic AMP; Dimethyl Fumarate; Fumarates; Furocoumarins; Genistein; Granulocytes; GTP Phosphohydrolases; GTP-Binding Proteins; Humans; Inositol 1,4,5-Trisphosphate; Intracellular Fluid; Isoflavones; Maleates; Protein Kinase C; Protein-Tyrosine Kinases; Psoriasis; Signal Transduction; Staurosporine

Footprinting of yeast DNA topoisomerase II and its NH2- and COOH-terminal truncation derivatives was carried out to map the locations of lysyl side chains that are involved in enzyme-DNA interaction, in the binding of ATP, or in interaction between domains of the same enzyme molecule. Several conclusions were drawn based on these measurements and the crystal structures of a 92-kDa fragment of the yeast enzyme and a 43-kDa fragment of Escherichia coli gyrase B-subunit. First, the footprinting results support the model previously inferred from the 92-kDa fragment crystal structure that the main site of DNA binding is comprised of a pair of semicircular grooves. Second, the binding of a nonhydrolyzable ATP analog to the yeast enzyme appears to affect citraconylation at a minimum of six lysines in the ATPase domain of each polypeptide. Two of these lysines are probably involved in contacting the nucleotide directly, and one probably becomes buried when the two ATPase domains of a dimeric enzyme come into contact upon ATP binding; for the others, changes in lysine reactivity appear to reflect allosteric changes following ATP binding. Third, from a comparison of the footprint of the intact enzyme and those of the truncated polypeptides comprised of either the NH2- or the COOH-terminal half of the intact polypeptide, it appears that there are few contacts between the NH2- and COOH-terminal half of yeast DNA topoisomerase II.

Topics: Adenylyl Imidodiphosphate; Binding Sites; DNA Topoisomerases, Type II; DNA, Fungal; Fumarates; Lysine; Maleates; Models, Molecular; Peptide Fragments; Peptide Mapping; Protein Binding; Saccharomyces cerevisiae; Substrate Specificity

Although the effectiveness of systemic antipsoriatic treatment with fumaric acid esters has been proven, their mode of action is still not understood. Recent results indicate their potency in inducing cytokine production in stimulated T cells. Since monocytes and their cytokines are also considered to be of pathogenic importance in psoriasis, we investigated the effect of monomethylfumarate (MMF) on proinflammatory (TNF-alpha, IL-12) and antiinflammatory (IL-10, IL-1RA) cytokine production by peripheral blood mononuclear cells (PBMC) and separated monocytes. In 24-h PBMC cultures from both psoriatic patients (n = 6-13) and healthy volunteers (n = 7-9), MMF at 100 microM induced secretion of TNF-alpha, IL-10, and IL-1RA. Kinetics of IL-10 protein and mRNA expression indicated de novo production. Moreover, MMF significantly augmented endotoxin-induced synthesis of TNF-alpha, IL-10 and IL-1RA. In contrast, no influence on IL-12 secretion was found. Similar effects of MMF in purified monocytes indicated these cells to be responsible for aberrant cytokine formation. Furthermore, enhanced expression of costimulatory molecules after MMF stimulation confirmed monocyte activation. Multiple restimulation with fumaric acid esters in vitro, however, and immunomonitoring in a patient during Fumaderm initial therapy suggested that initial monocyte activation is followed by subsequent deactivation associated with an antiinflammatory response. Our results may explain the well-known effects of therapy with fumaric acid esters. Thus, initial treatment is often accompanied by adverse effects which may be caused by MMF-induced TNF-alpha formation. The change in the IL-10/IL-12 balance as a result of elective induction of IL-10, however, may have antipsoriatic activity by diminishing type-1/proinflammatory cytokine over-expression and the antigen-presenting capacity of monocytes/macrophages, and by upregulation of IL-1RA.

Topics: Cells, Cultured; Cytokines; Fumarates; Humans; Maleates; Monocytes; Psoriasis; RNA, Messenger

Type 2 cytokines are thought to have a protective role in psoriasis vulgaris by dampening the activity of T helper 1 (Th1) lymphocytes. The aim of the present study was to determine the effect of monomethylfumarate (MMF), the most active metabolite of the new anti-psoriatic drug Fumaderm, on the production of cytokines and the development of Th subsets. MMF was found to enhance interleukin (IL)-4 and IL-5 production by CD2/CD8 monoclonal antibody-stimulated peripheral blood mononuclear cells (PBMC) in a dose-dependent manner. Maximal effects of MMF were found at a concentration of 200 microM and resulted in tenfold enhanced levels of IL-4 and IL-5 production. MMF did not affect the levels of IL-2 production, interferon (IFN)-gamma production or proliferative T cell responses in these cultures. Similar effects of MMF were observed in cultures of purified peripheral blood T cells indicating that this compound can act directly on T cells. MMF did not influence cytokine production by purified CD4+CD45RA+ (unprimed) T cells, but greatly enhanced IL-4 and IL-5 production without affecting IFN-gamma production by purified CD4+CD45RO+ (primed) T cells. Furthermore, MMF also augmented IL-4 and IL-5 production in established Th1/Th0 clones that were stimulated with CD2/CD28 monoclonal antibody. Finally, when PBMC were challenged with Mycobacterium tuberculosis that typically induces Th1 recall responses with strong IFN-gamma secretion, MMF again appeared to induce high levels of IL-4 and IL-5 secretion while IFN-gamma production was unaffected. These results may be relevant for the development of therapeutic regimens designed to correct inappropriate Th1 subset development in immunopathologic conditions.

Topics: Animals; Fumarates; Humans; Immunologic Memory; Interleukin-4; Interleukin-5; Leukocyte Common Antigens; Lymphocyte Activation; Maleates; Psoriasis; Sheep; Th2 Cells

Systemic administration of fumaric acid (FA) derivatives was originally an empirical antipsoriatic treatment, which showed promising clinical results. In the present study, FURA-2-loaded suspensions of cultured normal keratinocytes and SV40-transformed keratinocytes (SVK-14 cells) were used to study the effects of FA derivatives on the intracellular free calcium concentration ([Ca2+]i). Monomethylfumarate (MMF), dimethylfumarate (DMF) and monoethylfumarate (MEF) induced a rapid, transient [Ca2+]i increase in both cell types. This immediate increase reached maximal values of 396 nmol/l 10s after addition of MMF, and fell to basal values within 90-120 s (173 nmol/l for normal keratinocytes and 68 nmol/l for transformed keratinocytes). This increase was not affected by the prior addition of EGTA, indicating that FA derivatives released Ca2+ mainly from intracellular stores into the cytoplasm. Subsequently, dose-dependent inhibitory effects of FA derivatives on keratinocyte proliferation were demonstrated. The results of these experiments revealed that DMF was the most potent, MMF and MEF intermediate, and FA and malonic acid the least potent growth inhibitors. These antiproliferative effects of FA derivatives might be linked to the observed, transient [Ca2+]i elevations.

Topics: Anticarcinogenic Agents; Calcium; Cell Division; Cell Line, Transformed; Cells, Cultured; Depression, Chemical; Dimethyl Fumarate; Dose-Response Relationship, Drug; Fumarates; Humans; Intracellular Fluid; Keratinocytes; L-Lactate Dehydrogenase; Male; Maleates

Malease from Pseudomonas pseudoalcaligenes catalyses the hydration of both maleate and citraconate to D-malate and D-citramalate, respectively. The Kapp for these hydration reactions were 2050 and 104, respectively, under standard biochemical conditions (25 degrees C, pH 7.0, I = 0.1). The influence of the pH (6.0-8.5) on Kapp was determined. The Gibbs-free-energy changes under standard biochemical conditions for the hydration of the dianionic acids were calculated to be -19.28 kJ.mol-1 and -11.65 kJ.mol-1, respectively. From the obtained data together with data from the literature, the Gibbs free energy of formation of maleate2- and citraconate2- were calculated to be -588.91 kJ.mol-1 and -600.56 kJ.mol-1, respectively. The influence of the temperature (10-40 degrees C) on Kapp was determined for both hydration reactions. The enthalpy change (delta H degrees') and entropy change (delta S degrees') under standard biochemical conditions for the maleate2- (delta H degrees' = 18.07 kJ.mol-1, delta S degrees' = 2.94 J.mol-1 x K-1) and citraconate2- (delta H degrees' = -22.55 kJ.mol-1, delta S degrees' = -35.92 kJ.mol-1 x K-1) hydration reactions were calculated. The reaction rate of malease from Ps. pseudoalcaligenes was studied for both hydration reactions as a function of temperature. From these studies, the Gibbs free energies of activation for the maleate and citraconate hydration reactions catalysed by malease from Ps. pseudoalcaligenes were calculated to be 62.21 kJ.mol-1 and 63.43 kJ.mol-1, respectively.

Topics: Catalysis; Fumarates; Hydro-Lyases; Hydrogen-Ion Concentration; Kinetics; Maleates; Pseudomonas; Temperature; Thermodynamics; Water

Monomethylfumarate (MMF) is the most active metabolite of the new antipsoriasis drug Fumaderm. Because granulocytes play an important role in the pathophysiology of psoriasis, the effects of this drug on the functional activities of these cells were investigated. MMF stimulated polarization and elastase release, and enhanced the intracellular killing of bacteria by granulocytes. This compound suppressed the formyl-Met-Nle-Phe (FMLP)-stimulated respiratory burst in these cells. MMF and dimethylfumarate but not its stereoisomer dimethylmaleate, fumaric acid, or dimethylmalate stimulated polarization of and elastase release by granulocytes, indicating that methylated fumarate derivatives interact with granulocytes in a specific fashion. MMF did not affect the binding of formyl-Nle-Leu-Phe-Nle-Tyr-Lys-fluorescein isothiocyanate to the FMLP receptor on granulocytes. This compound induced an increase in the intracellular Ca++ ([Ca++]i) and cyclic adenosine monophsphate concentration. The agonistic effects of MMF on granulocytes are thought to be mediated by the rise in the [Ca++]i and the antagonistic effects by the increase in the cyclic adenosine monophosphate concentration. These effects of MMF on granulocytes may in part explain the beneficial action of methylated fumarate derivatives on psoriatic skin lesions.

Topics: Blood Bactericidal Activity; Cell Polarity; Cell-Free System; Chemotaxis, Leukocyte; Cyclic AMP; Fluorescein-5-isothiocyanate; Fumarates; Granulocytes; Humans; Maleates; Mycobacterium; N-Formylmethionine Leucyl-Phenylalanine; NADH, NADPH Oxidoreductases; Oligopeptides; Oxygen Consumption; Pancreatic Elastase; Reactive Oxygen Species; Stimulation, Chemical

Topics: Fermentation; Fumarates; Liver; Maleates

Topics: Anthracenes; Citraconic Anhydrides; Fumarates; Maleates

Topics: Citraconic Anhydrides; Fumarates; Maleates