Fumaric acid esters

Fumaric acid per se and in combination with methotrexate arrests inflammation via moderating inflammatory and oxidative stress biomarkers in arthritic rats

Objective: Fumaric acid is a dicarboxylic acid that belongs to the phenolic class enriched in fruits and vegetables that are traditionally used for the treatment of various ailments. The research was planned to find out the anti-inflammatory and anti-arthritic activities of fumaric acid using in-vitro and in-vivo assays. Moreover, safety study was also done.

Materials and methods: The 0.1 ml complete Freund's adjuvant was injected in left hind paw in all Wistar rats except normal rats at day 1 to induced arthritis. The treatment with fumaric acid at 10, 20, 40, and fumaric acid 40 mg/kg together with methotrexate (MTX) was administered to immunized rats at 8th day via oral gavage and continued till 28th day though, MTX was administered as standard control.

Results: The fumaric acid notably (p < 0.0001) lessened the paw edema and arthritic scoring, reinstated body and immune organ weight, and oxidation status in treated rats. Fumaric acid notably restored altered C-reactive protein, rheumatoid factor, liver function tests, ESR, WBCs, RBCs and Hb levels in treated rats. The fumaric acid in combination noticeably (p < 0.01-0.0001) suppressed the expression of TNF- α, IL-6, IL-1β, NF-kβ, and COX-2, and over expressed IL-4, and IL-10 in contrast to other treated groups. Fumaric acid had presented a dose-dependent antioxidant, anti-inflammatory and anti-arthritic activities while notable activity exhibited by fumaric acid in combination with MTX. The fumaric acid exhibited non-significant clinical signs of toxicity and mortality in acute toxicity study. The LD50 was more than 2000 mg/kg.

Conclusion: Fumaric acid in combination can be used as disease-modifying anti-rheumatic drug but it will need extensive pre-clinical and clinical studies.

The Role of NRF2 in Trinucleotide Repeat Expansion Disorders

Trinucleotide repeat expansion disorders, a diverse group of neurodegenerative diseases, are caused by abnormal expansions within specific genes. These expansions trigger a cascade of cellular damage, including protein aggregation and abnormal RNA binding. A key contributor to this damage is oxidative stress, an imbalance of reactive oxygen species that harms cellular components. This review explores the interplay between oxidative stress and the NRF2 pathway in these disorders. NRF2 acts as the master regulator of the cellular antioxidant response, orchestrating the expression of enzymes that combat oxidative stress. Trinucleotide repeat expansion disorders often exhibit impaired NRF2 signaling, resulting in inadequate responses to excessive ROS production. NRF2 activation has been shown to upregulate antioxidative gene expression, effectively alleviating oxidative stress damage. NRF2 activators, such as omaveloxolone, vatiquinone, curcumin, sulforaphane, dimethyl fumarate, and resveratrol, demonstrate neuroprotective effects by reducing oxidative stress in experimental cell and animal models of these diseases. However, translating these findings into successful clinical applications requires further research. In this article, we review the literature supporting the role of NRF2 in the pathogenesis of these diseases and the potential therapeutics of NRF2 activators.

Sulforaphane Ameliorates the Severity of Psoriasis and SLE by Modulating Effector Cells and Reducing Oxidative Stress

Background: Sulforaphane, which is found in cruciferous vegetables, has been reported to have anti-inflammatory, antioxidant, and antitumour activities. However, whether sulforaphane has therapeutic effects on inflammatory or autoimmune skin diseases, including psoriasis and systemic lupus erythematosus (SLE), is unclear.

Methods: The therapeutic effects of sulforaphane were analyzed in Imiquimod (IMQ)-induced psoriasis-like mice and lupus-prone MRL/lpr mice. In IMQ-induced psoriasis-like mice treated with sulforaphane (55.3 and 110.6 μmol/kg) or vehicle control, the pathological phenotypes were assessed by the psoriasis area and severity index (PASI) score, haematoxylin-eosin staining (H&amp;E) and quantifying of acanthosis and dermal inflammatory cell infiltration. The proportions of T cell subsets in draining lymph nodes (dLNs) and spleens were examined by flow cytometry. In MRL/lpr mice treated with sulforaphane (82.9 μmol/kg) or vehicle control, mortality and proteinuria were observed, and the glomerular pathology was examined by H&amp;E staining. C3 and IgG depositions in kidney sections were examined by immunofluorescence staining. The proportions of plasma cells, follicular helper T (Tfh) cells, neutrophils and dendritic cells in the dLNs and spleens were examined by flow cytometry. Finally, we examined the Malondialdehyde (MDA) concentration by thiobarbituric acid reactive substance assay and the expression of Prdx1, Nqo1, Hmox1, and Gss by reverse transcription-quantitative polymerase chain reaction (RT-qPCR).

Results: Sulforaphane ameliorated the skin lesions in IMQ-induced psoriasis-like mice and the renal damage in lupus-prone MRL/lpr mice. In IMQ-induced psoriasis-like mice, sulforaphane reduced the proportions of Th1 and Th17 cells and increased the expression of antioxidant gene Prdx1. In lupus-prone MRL/lpr mice, sulforaphane increased the lifespan and the expression of Prdx1, and decreased the proportions of plasma cells, Tfh cells, neutrophils, and dendritic cells in the dLNs and spleens and the concentration of MDA.

Conclusion: Sulforaphane has significant therapeutic effects on IMQ-induced psoriasis-like mice and lupus-like MRL/Lpr mice by reducing inflammatory and autoimmune-related cells and oxidative stress. These findings provide new evidence for developing natural products to treat inflammatory and autoimmune diseases.

Standard of care versus new-wave corticosteroids in the treatment of Duchenne muscular dystrophy: Can we do better?

BACKGROUND

Pharmacological corticosteroid therapy is the standard of care in Duchenne Muscular Dystrophy (DMD) that aims to control symptoms and slow disease progression through potent anti-inflammatory action. However, a major concern is the significant adverse effects associated with long term-use. MAIN: This review discusses the pros and cons of standard of care treatment for DMD and compares it to novel data generated with the new-wave dissociative corticosteroid, vamorolone. The current status of experimental anti-inflammatory pharmaceuticals is also reviewed, with insights regarding alternative drugs that could provide therapeutic advantage.

CONCLUSIONS

Although novel dissociative steroids may be superior substitutes to corticosteroids, other potential therapeutics should be explored. Repurposing or developing novel pharmacological therapies capable of addressing the many pathogenic features of DMD in addition to anti-inflammation could elicit greater therapeutic advantages.

Dimethyl Fumarate and Its Esters: A Drug with Broad Clinical Utility?

Fumaric acid esters (FAEs) are small molecules with anti-oxidative, anti-inflammatory and immune-modulating effects. Dimethyl fumarate (DMF) is the best characterised FAE and is approved and registered for the treatment of psoriasis and Relapsing-Remitting Multiple Sclerosis (RRMS). Psoriasis and RRMS share an immune-mediated aetiology, driven by severe inflammation and oxidative stress. DMF, as well as monomethyl fumarate and diroximel fumarate, are commonly prescribed first-line agents with favourable safety and efficacy profiles. The potential benefits of FAEs against other diseases that appear pathogenically different but share the pathologies of oxidative stress and inflammation are currently investigated.

Proposed Neuroimmune Roles of Dimethyl Fumarate, Bupropion, S-Adenosylmethionine, and Vitamin D3 in Affording a Chronically Ill Patient Sustained Relief from Inflammation and Major Depression

We had discussed earlier that, after most of the primary author's multiple sclerosis (MS) symptoms were lessened by prior neuroimmune therapies, use of dimethyl fumarate (DMF) gradually subdued his asthma and urticaria symptoms, as well as his MS-related intercostal cramping; and bupropion supplemented with S-adenosylmethionine (SAMe) and vitamin D3 (vit-D3) helped remit major depression (MD). Furthermore, the same cocktail (bupropion plus supplements), along with previously discussed routines (yoga, meditation, physical exercises, and timely use of medications for other illnesses), continued to subdue MD during new difficulties with craniopharyngioma, which caused bitemporal vision loss; sphenoid sinus infections, which caused cranial nerve-VI (CN6) palsy and diplopia; and through their treatments. Impressed by the benefit the four compounds provided, in this manuscript, we focus on explaining current neuroimmune literature proposals on how: (1) DMF impedes inflammation, oxidative stress, and cell death in CNS and peripheral tissues; (2) Bupropion curbs anxiety, MD, and enhances alertness, libido, and moods; (3) SAMe silences oxidative stress and depression by multiple mechanisms; and (4) Vit-D3 helps brain development and functioning and subdues inflammation. we realize that herein we have reviewed proposed mechanisms of remedies we discovered by literature searches and physician assisted auto-experimentation; and our methods might not work with other patients. We present our experiences so readers are heartened to reflect upon their own observations in peer-reviewed forums and make available a wide body of information for the chronically ill and their physicians to benefit from.

Comparative analysis of smear layer removal by conventional endodontic irrigants with a newly experimented irrigant-fumaric acid: A scanning electron microscopic study

Introduction:

This study was aimed to evaluate the efficacy of 17% ethylenediaminetetraacetate (EDTA), 7% maleic acid and 0.7% fumaric acid in smear layer removal from the root canal walls.

Materials and Methods:

Forty single-rooted mandibular premolars were collected and prepared till F3 rotary ProTaper file with 1 ml of 3% of sodium hypochlorite after each instrument change. Samples were randomly divided into 4 groups according to the final irrigating solution: 17% EDTA, 7% maleic acid, 0.7% fumaric acid, and 0.9% saline. The samples were prepared for scanning electron microscope analysis to observe smear layer removal at coronal, middle, and apical third level of root canal system.

Results:

At coronal third level, fumaric acid was equally efficient in smear layer removal when compared to maleic acid and EDTA without any significant difference between them. At the middle third, fumaric acid showed significantly better results than maleic acid followed by EDTA. At the apical third, both fumaric acid and maleic acid were equally effective without any significant difference between them but both showed significantly better results than EDTA.

Conclusion:

Fumaric acid can be tried as a new irrigating agent for smear layer removal in root canal system.

Multiple mechanisms of dimethyl fumarate in amyloid β-induced neurotoxicity in human neuronal cells

Alzheimer disease (AD) is characterized by a complex heterogeneity of pathological changes, and any therapeutic approach categorically requires a multi-targeted way. It has been demonstrated that together with the hallmarks of the disease such as neurofibrillary tangles and senile plaques, oxidative and inflammatory stress covered an important role. Dimethyl fumarate (DMF) is an orally bioavailable methyl ester of fumaric acid and activator of Nrf2 with potential neuroprotective and immunomodulating activities. Therefore, the aim of the present work was to evaluate the potential beneficial effects of DMF, compared with its active metabolite monomethyl fumarate (MMF) (both at 30 μM) in an in vitro Alzheimer's model using SH-SY5Y human neuroblastoma cell lines stimulated with amyloid-beta (Aβ). Moreover, the effect of DMF, compared with MMF, was evaluate by an ex vivo model using organotypic hippocampal slice cultures stimulated with Aβ1-42 (1 μg/ml), to better understand its action in a pathological setting. In both models, DMF pre-treatment (30 μM) preserved cellular viability from Aβ stimulation, reducing tau hyper-phosphorylation, much more efficiently then MMF (30 μM). Moreover, DMF was able to induce an activation of manganese superoxide dismutase (MnSOD) and heme-oxygenase-1 (HO-1), decreasing the severity of oxidative stress. Our results showed important multi-protective effects of DMF pre-treatment from Aβ stimulation both in in vitro and ex vivo models, highlighting an Nrf2/NF-κB-dependent mechanism, which could provide a valuable support to the therapies for neurodegenerative diseases today.

Dimethyl fumarate modulates neutrophil extracellular trap formation in a glutathione- and superoxide-dependent manner

BACKGROUND

Neutrophil (polymorphonuclear) granulocytes (PMN) have been shown to contribute to the pathogenesis of psoriasis by releasing interleukin-17 and LL37-DNA complexes via neutrophil extracellular traps (NETs), webs of chromatin strands decorated with antimicrobial peptides, in psoriatic skin. Fumaderm^® , a fumaric acid ester (FAE) formulation consisting of different FAE salts, has been successfully used to treat psoriasis for decades. Most recently, FAE treatment was reported to inhibit NET formation in murine epidermolysis bullosa acquisita.

OBJECTIVES

To elucidate the effect of FAE treatment on human psoriasis and healthy donor NET formation.

RESULTS

Among the compounds present in the FAE formulation, dimethyl fumarate (DMF) pretreatment of human psoriasis and healthy donor PMN resulted in a consistent inhibitory effect on NET formation in response to phorbol 12-myristate 13-acetate but not to platelet activating factor and ionomycin. This effect was l-glutathione (GSH) dependent and involved a decrease in reactive oxygen species (ROS) production, a key event in NET formation. In contrast, G-protein-coupled signalling and protein synthesis were not involved. Monomethyl fumarate (MMF) was found to slightly reduce ROS production without affecting NET formation.

CONCLUSIONS

We report DMF as a potent, stimulus-specific, GSH- and ROS-dependent modulator of NET formation. Our results support the notion that modulation of NET formation contributes to the beneficial effects of FAEs in a variety of inflammatory conditions.

Attenuation of 7-ketocholesterol-induced overproduction of reactive oxygen species, apoptosis, and autophagy by dimethyl fumarate on 158N murine oligodendrocytes

Mitochondrial dysfunctions and oxidative stress are involved in several non demyelinating or demyelinating neurodegenerative diseases. Some of them, including multiple sclerosis (MS), are associated with lipid peroxidation processes leading to increased levels of 7-ketocholesterol (7KC). So, the eventual protective effect of dimethylfumarate (DMF), which is used for the treatment of MS, was evaluated on 7KC-treated oligodendrocytes, which are myelin synthesizing cells. To this end, murine oligodendrocytes 158N were exposed to 7KC (25, 50μM) for 24h without or with DMF (1, 25, 50μM). The biological activities of DMF associated or not with 7KC were evaluated by phase contrast microscopy, crystal violet and MTT tests. The impact on transmembrane mitochondrial potential (ΔYm), O₂^- and H₂O₂ production, apoptosis and autophagy was measured by microscopical and flow cytometric methods by staining with DiOC₆(3), dihydroethidine and dihydrorhodamine 123, Hoechst 33342, and by Western blotting with the use of specific antibodies raised against uncleaved and cleaved caspase-3 and PARP, and LC3-I/II. DMF attenuates the different effects of 7KC, namely: cell growth inhibition and/or loss of cell adhesion, decrease of ΔΨm, O₂^- and H₂O₂ overproduction, PARP and caspase-3 cleavage, nuclear condensation and fragmentation, and activation of LC3-I into LC3-II. The ability of DMF to attenuate 7KC-induced reactive oxygen species overproduction, apoptosis, and autophagy on oligodendrocytes reinforces the interest for this molecule for the treatment of MS or other demyelinating diseases.

Hydroxy-Carboxylic Acid Receptor Actions in Metabolism

Lactic acid, the ketone body 3-hydroxy-butyric acid, also known as β-hydroxybutyrate, and the β-oxidation intermediate 3-hydroxy-octanoic acid are hydroxy-carboxylic acids (HCAs) that serve as intermediates of energy metabolism. However, they also regulate cellular functions, in part by directly activating the G protein-coupled receptors HCA₁/GPR81, HCA₂/GPR109A, and HCA₃/GPR109B. During the past decade, it has become clear that HCA receptors help to maintain homeostasis under changing metabolic and dietary conditions, by controlling metabolic, immune, and other body functions. Work based on genetic mouse models and synthetic ligands of HCA receptors has, in addition, shown that members of this receptor family can serve as targets for the prevention and therapy of diseases such as metabolic and inflammatory disorders.

Design of simulated moving bed for separation of fumaric acid with a little fronting phenomenon

The production of fumaric acid through a biotechnological pathway has grown in importance because of its potential value in related industries. This has sparked an interest in developing an economically-efficient process for separation of fumaric acid (product of interest) from acetic acid (by-product). This study aimed to develop a simulated moving bed (SMB) chromatographic process for such separation in a systematic way. As a first step for this work, commercially available adsorbents were screened for their applicability to the considered separation, which revealed that an Amberchrom-CG71C resin had a sufficient potential to become an adsorbent of the targeted SMB. Using this adsorbent, the intrinsic parameters of fumaric and acetic acids were determined and then applied to optimizing the SMB process under consideration. The optimized SMB process was tested experimentally, from which the yield of fumaric-acid product was found to become lower than expected in the design. An investigation about the reason for such problem revealed that it was attributed to a fronting phenomenon occurring in the solute band of fumaric acid. To resolve this issue, the extent of the fronting was evaluated quantitatively using an experimental axial dispersion coefficient for fumaric acid, which was then considered in the design of the SMB of interest. The SMB experimental results showed that the SMB design based on the consideration of the fumaric-acid fronting could guarantee the attainment of both high purity (>99%) and high yield (>99%) for fumaric-acid product under the desorbent consumption of 2.6 and the throughput of 0.36L/L/h.

Dimethyl Fumarate Induces Glutathione Recycling by Upregulation of Glutathione Reductase

Neuronal degeneration in multiple sclerosis has been linked to oxidative stress. Dimethyl fumarate (DMF) is an effective oral therapeutic option shown to reduce disease activity and progression in patients with relapsing-remitting multiple sclerosis. DMF activates the transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) leading to increased synthesis of the major cellular antioxidant glutathione (GSH) and prominent neuroprotection in vitro. We previously demonstrated that DMF is capable of raising GSH levels even when glutathione synthesis is inhibited, suggesting enhanced GSH recycling. Here, we found that DMF indeed induces glutathione reductase (GSR), a homodimeric flavoprotein that catalyzes GSSG reduction to GSH by using NADPH as a reducing cofactor. Knockdown of GSR using a pool of E. coli RNase III-digested siRNAs or pharmacological inhibition of GSR, however, also induced the antioxidant response rendering it impossible to verify the suspected attenuation of DMF-mediated neuroprotection. However, in cystine-free medium, where GSH synthesis is abolished, pharmacological inhibition of GSR drastically reduced the effect of DMF on glutathione recycling. We conclude that DMF increases glutathione recycling through induction of glutathione reductase.

Psoriasis, psoriatic arthritis, and rheumatoid arthritis: Is all inflammation the same?

OBJECTIVES

To review the pathophysiology, co-morbidities, and therapeutic options for psoriasis, psoriatic arthritis and rheumatoid arthritis in order to further understand the similarities and differences in treatment paradigms in the management of each disease. New targets for individualized therapeutic decisions are also identified with the aim of improving therapeutic outcome and reducing toxicity.

SEARCH STRATEGY

Using the PubMed database, we searched literature published from 2000 to 2015 using combinations of the key words "psoriasis," "psoriatic arthritis," "rheumatoid arthritis," "pathogenesis," "immunomodulation," and "treatment."

INCLUSION AND EXCLUSION CRITERIA

This was a non-systematic review and there were no formal inclusion and exclusion criteria.

DATA EXTRACTION

Abstracts identified in the search were screened for relevance and articles considered appropriate evaluated further. References within these selected articles were also screened. Information was extracted from 198 articles for inclusion in this report.

DATA SYNTHESIS

There was no formal data synthesis. Articles were reviewed and summarized according to disease area (psoriasis, psoriatic arthritis, and rheumatoid arthritis).

HEADLINE RESULTS

The pathophysiology of psoriasis, psoriatic arthritis, and rheumatoid arthritis involves chronic inflammation mediated by pro-inflammatory cytokines. Dysfunction in integrated signaling pathways affecting different constituents of the immune system result in varying clinical features in the three diseases. Co-morbidities, including cardiovascular disease, malignancies, and non-alcoholic fatty liver disease are increased. Increased understanding of the immunopathogenesis allowed development of targeted treatments; however, despite a variety of potentially predictive genetic, protein and cellular biomarkers, there is still significant unmet need in these three inflammatory disorders.

Severe recalcitrant cutaneous manifestations in systemic lupus erythematosus successfully treated with fumaric acid esters

Fumaric acid esters (FAEs) have proven efficacy in the treatment of psoriasis and have been in use for decades. More recently, as their mechanism of action and abundant immunomodulatory effects become clearer, the potential benefits of treating other inflammatory skin conditions using FAEs are increasingly being recognized. The use of FAEs as combination systemic therapy has not been well studied and data are lacking regarding the safety and efficacy of this type of therapy. In this case report, three patients with severe, extensive and recalcitrant cutaneous manifestations of systemic lupus erythematosus (SLE) (one case of disseminated discoid lesions and two with severe chilblain lesions) were treated with Fumaderm^® (containing the FAE dimethylfumarate and monoethylhydrogen fumarate salts), after failing to respond to a multitude of other monotherapies and combination therapies. All patients showed a substantial clinical response when FAEs were added to their treatment, with concurrent improvements in quality-of-life instrument scores. The treatment was well tolerated in the context of systemic organ involvement and as combination therapy with other agents, such as hydroxychloroquine and mycophenolate mofetil. These cases of SLE illustrate the potential use of FAEs in severe, disfiguring and otherwise therapy-resistant skin lesions, including, to our knowledge, the first two reported cases of FAE-treated chilblain lupus erythematosus.

Oxidative stress in psoriasis and potential therapeutic use of antioxidants

The pathophysiology of psoriasis is complex and dynamic. Recently, the involvement of oxidative stress in the pathogenesis of psoriasis has been proposed. Oxidative stress is an imbalance between oxidants and antioxidants in favor of the oxidants, leading to a disruption of redox signaling and control and/or molecular damage. In this article, the published studies on the role of oxidative stress in psoriasis pathogenesis are reviewed, focusing on the impacts of oxidative stress on dendritic cells, T lymphocytes, and keratinocytes, on angiogenesis and on inflammatory signaling (mitogen-activated protein kinase, nuclear factor-κB, and Janus kinase/signal transducer and activator of transcription). As there is compelling evidence that oxidative stress is involved in the pathogenesis of psoriasis, the possibility of using this information to develop novel strategies for treatment of patients with psoriasis is of considerable interest. In this article, we also review the published studies on treating psoriasis with antioxidants and drugs with antioxidant activity.

Dimethylfumarate effectively inhibits lymphangiogenesis via p21 induction and G1 cell cycle arrest

Different pathologies, such as lymphoedema, cancer or psoriasis, are associated with abnormal lymphatic vessel formation. Therefore, influencing lymphangiogenesis is an interesting target. Recent evidence suggests that dimethylfumarate (DMF), an antipsoriatic agent, might have antitumorigenic and antilymphangiogenic properties. To prove this assumption, we performed proliferation and functional assays with primary human dermal lymphendothelial cells (DLEC). We could demonstrated that DMF suppresses DLEC proliferation and formation of capillary-like structures. Underlying apoptotic mechanisms could be ruled out. Cell cycle analysis demonstrated a pronounced G1-arrest. Further evaluations revealed increases in p21 expression. In addition, DMF suppressed Cyclin D1 and Cyclin A expression in a concentration-dependent manner. p21 knockdown experiments demonstrated a p21-dependent mechanism of regulation. Further analysis showed an increased p21 mRNA expression after DMF treatment. This transcriptional regulation was enforced by post-transcriptional and post-translational mechanisms. In addition, we could demonstrate that the combination of a proteasomal inhibitor and DMF superinduced the p21 expression. Hence, DMF is a new antilymphangiogenic compound and might be used in various illnesses associated with increased lymphangiogenesis.

Mutually enhancing anti-inflammatory activities of dimethyl fumarate and NF-κB inhibitors--implications for dose-sparing combination therapies

Fumaric acid esters, dimethyl fumarate (DMF) in particular, have been established for the therapy of psoriasis and, more recently, multiple sclerosis. In the light of therapy-limiting dose-dependent side effects, such as gastrointestinal irritation, reducing the effective doses of FAE is a worthwhile goal. In search of strategies to maintain the anti-inflammatory activity of DMF at reduced concentrations, we found that NF-κB inhibition augmented key anti-inflammatory effects of DMF in two complementary experimental settings in vitro. At non-toxic concentrations, both proteasome inhibition with bortezomib as well as blocking NF-κB activation through KINK-1, a small molecule inhibitor of IKKβ-profoundly enhanced DMF-dependent inhibition of nuclear NF-κB translocation in TNFα-stimulated human endothelial cells. This resulted in significant and selective co-operative down-regulation of endothelial adhesion molecules crucial for leucocyte extravasation, namely E-selectin (CD62E), VCAM-1 (CD106) and ICAM-1 (CD54), on both mRNA and protein levels. Functionally, these molecular changes led to synergistically decreased rolling and firm adhesion of human lymphocytes on TNF-activated endothelial cells, as demonstrated in a dynamic flow chamber system. If our in vitro findings can be translated into clinical settings, it is conceivable that anti-inflammatory effects of DMF can be achieved with lower doses than currently used, thus potentially reducing unwanted side effects.

Drug-induced Fanconi syndrome associated with fumaric acid esters treatment for psoriasis: a case series

BACKGROUND

Fumaric acid esters (FAEs), an oral immunomodulating treatment for psoriasis and multiple sclerosis, have been anecdotally associated with proximal renal tubular dysfunction due to a drug-induced Fanconi syndrome. Few data are available on clinical outcomes of FAE-induced Fanconi syndrome.

METHODS

Descriptive case series with two cases of Fanconi syndrome associated with FAE treatment diagnosed at two Dutch university nephrology departments, three cases reported at the Dutch and German national pharmacovigilance databases and six previously reported cases.

RESULTS

All 11 cases involved female patients with psoriasis. The median age at the time of onset was 38 years [interquartile range (IQR) 37-46]. Patients received long-term FAEs treatment with a median treatment duration of 60 months (IQR 28-111). Laboratory tests were typically significant for low serum levels of phosphate and uric acid, while urinalysis showed glycosuria and proteinuria. Eight (73%) patients had developed a hypophosphataemic osteomalacia and three (27%) had pathological bone fractures. All patients discontinued FAEs, while four (36%) patients were treated with supplementation of phosphate and/or vitamin D. Five (45%) patients had persisting symptoms despite FAEs discontinuation.

CONCLUSIONS

FAEs treatment can cause drug-induced Fanconi syndrome, but the association has been reported infrequently. Female patients with psoriasis treated long term with FAEs seem to be particularly at risk. Physicians treating patients with FAEs should be vigilant and monitor for the potential occurrence of Fanconi syndrome. Measurement of the urinary albumin:total protein ratio is a suggested screening tool for tubular proteinuria in Fanconi syndrome.

DMF, but not other fumarates, inhibits NF-κB activity in vitro in an Nrf2-independent manner

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.

Systemic antipsoriatic combination therapy with fumaric acid esters for plaque-type psoriasis: report on 17 cases

BACKGROUND

In the literature as well as in existing psoriasis guidelines, only little evidence is available on combination regimens with systemic antipsoriatic agents. However, if systemic monotherapy is not efficacious enough to control the disease, a combination therapy might be necessary.

OBJECTIVE

To evaluate the use of fumaric acid esters (FAEs) in combination with other antipsoriatic agents in 6 specialized dermatological departments in Germany.

METHODS

A systematic retrospective chart review of patients receiving FAEs was performed.

RESULTS

A total of 17 cases of patients receiving FAEs combined with at least one other systemic therapy (methotrexate, acitretin, etanercept, cyclosporine, leflunomide and infliximab) to treat psoriasis or psoriatic arthritis were identified.

CONCLUSION

FAEs can be combined in an off-label setting with conventional as well as biological agents to treat recalcitrant psoriasis or psoriatic arthritis. Safety monitoring should be taken seriously as no controlled data for these combination regimens exist.

Safety of conventional systemic therapies for psoriasis on reproductive potential and outcomes

The effects of conventional systemic therapies for psoriasis on pregnancy outcomes, lactation, male fertility and mutagenicity are common concerns in the clinical setting. There is relatively little evidence to guide clinician and patient. In this study, we review the safety profile of the commonly used conventional systemic therapies used for psoriasis in individuals of reproductive potential. Safety data are derived from large-scale registries, adverse-event reporting databases, clinical trials and case reports. We assess the effect of each therapy on adverse pregnancy outcomes, including congenital malformations, and lactation with maternal administration. We also assess the effect of the therapies on male fertility and potential mutagenicity with paternal administration. We provide applicable guidance to inform clinician and patient before and after conception.

Dimethylfumarate alleviates early brain injury and secondary cognitive deficits after experimental subarachnoid hemorrhage via activation of Keap1-Nrf2-ARE system

OBJECT

Oxidative stress and the inflammatory response are thought to promote brain damage in the setting of subarachnoid hemorrhage (SAH). Previous reports have shown that dimethylfumarate (DMF) can activate the Kelch-like ECH-associated protein 1-nuclear factor erythroid 2-related factor 2-antioxidant-responsive element (Keap1-Nrf2-ARE) system in vivo and in vitro, which leads to the downregulation of oxidative stress and inflammation. The aim of this study was to evaluate the potential neuroprotective effect of DMF on SAH-induced brain injury in rats.

METHODS

Rats were subjected to SAH by the injection of 300 μl of autologous blood into the chiasmatic cistern. Rats in a DMF-treated group were given 15 mg/kg DMF twice daily by oral gavage for 2 days after the onset of SAH. Cortical apoptosis, neural necrosis, brain edema, blood-brain barrier impairment, learning deficits, and changes in the Keap1-Nrf2-ARE pathway were assessed.

RESULTS

Administration of DMF significantly ameliorated the early brain injury and learning deficits induced by SAH in this animal model. Treatment with DMF markedly upregulated the expressions of agents related to Keap1-Nrf2-ARE signaling after SAH. The inflammatory response and oxidative stress were downregulated by DMF therapy.

CONCLUSIONS

DMF administration resulted in abatement of the development of early brain injury and cognitive dysfunction in this prechiasmatic cistern SAH model. This result was probably mediated by the effect of DMF on the Keap1-Nrf2-ARE system.

The antipsoriatic agent monomethylfumarate has antiproliferative, prodifferentiative, and anti-inflammatory effects on keratinocytes

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.

Dimethylfumarate induces apoptosis in human mast cells

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.

Molecular pharmacodynamics of new oral drugs used in the treatment of multiple sclerosis

New oral drugs have considerably enriched the therapeutic armamentarium for the treatment of multiple sclerosis. This review focuses on the molecular pharmacodynamics of fingolimod, dimethyl fumarate (BG-12), laquinimod, and teriflunomide. We specifically comment on the action of these drugs at three levels: 1) the regulation of the immune system; 2) the permeability of the blood-brain barrier; and 3) the central nervous system. Fingolimod phosphate (the active metabolite of fingolimod) has a unique mechanism of action and represents the first ligand of G-protein-coupled receptors (sphingosine-1-phosphate receptors) active in the treatment of multiple sclerosis. Dimethyl fumarate activates the nuclear factor (erythroid-derived 2)-related factor 2 pathway of cell defense as a result of an initial depletion of reduced glutathione. We discuss how this mechanism lies on the border between cell protection and toxicity. Laquinimod has multiple (but less defined) mechanisms of action, which make the drug slightly more effective on disability progression than on annualized relapse rate in clinical studies. Teriflunomide acts as a specific inhibitor of the de novo pyrimidine biosynthesis. We also discuss new unexpected mechanisms of these drugs, such as the induction of brain-derived neurotrophic factor by fingolimod and the possibility that laquinimod and teriflunomide regulate the kynurenine pathway of tryptophan metabolism.

Monomethylfumarate induces γ-globin expression and fetal hemoglobin production in cultured human retinal pigment epithelial (RPE) and erythroid cells, and in intact retina

PURPOSE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Free fatty acid (FFA) and hydroxy carboxylic acid (HCA) receptors

Saturated and unsaturated free fatty acids (FFAs), as well as hydroxy carboxylic acids (HCAs) such as lactate and ketone bodies, are carriers of metabolic energy, precursors of biological mediators, and components of biological structures. However, they are also able to exert cellular effects through G protein-coupled receptors named FFA1-FFA4 and HCA1-HCA3. Work during the past decade has shown that these receptors are widely expressed in the human body and regulate the metabolic, endocrine, immune and other systems to maintain homeostasis under changing dietary conditions. The development of genetic mouse models and the generation of synthetic ligands of individual FFA and HCA receptors have been instrumental in identifying cellular and biological functions of these receptors. These studies have produced strong evidence that several FFA and HCA receptors can be targets for the prevention and treatment of various diseases, including type 2 diabetes mellitus, obesity, and inflammation.

Therapeutic decisions in multiple sclerosis: moving beyond efficacy

Several innovative disease-modifying treatments (DMTs) for relapsing-remitting multiple sclerosis have been licensed recently or are in late-stage development. The molecular targets of several of these DMTs are well defined. All affect at least 1 of 4 properties, namely (1) trafficking, (2) survival, (3) function, or (4) proliferation. In contrast to β-interferons and glatiramer acetate, the first-generation DMTs, several newer therapies are imbued with safety issues, which may be attributed to their structure or metabolism. In addition to efficacy, understanding the relationship between the mechanism of action of the DMTs and their safety profile is pertinent for decision making and patient care. In this article, we focus primarily on the safety of DMTs in the context of understanding their pharmacological characteristics, including molecular targets, mechanism of action, chemical structure, and metabolism. While understanding mechanisms underlying DMT toxicities is incomplete, it is important to further develop this knowledge to minimize risk to patients and to ensure future therapies have the most advantageous benefit-risk profiles. Recognizing the individual classes of DMTs described here may be valuable when considering use of such agents sequentially or possibly in combination.

Anti-inflammatory dimethylfumarate: a potential new therapy for asthma?

Asthma is a chronic inflammatory disease of the airways, which results from the deregulated interaction of inflammatory cells and tissue forming cells. Beside the derangement of the epithelial cell layer, the most prominent tissue pathology of the asthmatic lung is the hypertrophy and hyperplasia of the airway smooth muscle cell (ASMC) bundles, which actively contributes to airway inflammation and remodeling. ASMCs of asthma patients secrete proinflammatory chemokines CXCL10, CCL11, and RANTES which attract immune cells into the airways and may thereby initiate inflammation. None of the available asthma drugs cures the disease—only symptoms are controlled. Dimethylfumarate (DMF) is used as an anti-inflammatory drug in psoriasis and showed promising results in phase III clinical studies in multiple sclerosis patients. In regard to asthma therapy, DMF has been anecdotally reported to reduce asthma symptoms in patients with psoriasis and asthma. Here we discuss the potential use of DMF as a novel therapy in asthma on the basis of in vitro studies of its inhibitory effect on ASMC proliferation and cytokine secretion in ASMCs.