Dimethyl fumarate in the treatment of relapsing-remitting multiple sclerosis: an overview

Recent Advances in the Treatment for Multiple Sclerosis; Current New Drugs Specific for Multiple Sclerosis

Since the first approved parenteral drug for the treatment of multiple sclerosis (MS) in 1993 (interferon [IFN] beta, and later glatiramer acetate [GA]), today there are both parenteral and oral treatment options for MS. After IFN beta preparations, glatiramer acetate was developed; and, until the approval of natalizumab in 2006, those dominated the treatment of MS. Later on, among oral drug options, cladribine made a promising entry; however, due to safety concerns, it was withdrawn soon. Afterwards, with the understanding of the role of sphingosine-1 phosphate (S1P) receptors in the pathogenesis of MS, fingolimod was approved in 2010, which was followed by other oral agents such as teriflunomide and dimethyl fumarate. Recently newer IV treatment options such as alemtuzumab, rituximab and ocrelizumab have widened the treatment arena. Recently, after submitting new efficacy and safety data, cladribine was approved for MS by EMA, in 2017. Moreover, seven years after its rejection due to safety reasons, in August 2018 FDA accepted to re-evaluate the data of cladribine as a treatment option for relapsing remitting MS (RRMS). Another oral treatment option, Laquinimod, was not approved because it could not be shown to slow disability progression despite favourable effect in relapsing MS. Newer generation S1P receptor modulators are being investigated currently, and they are expected to come into the treatment arena soon. In this article, mechanisms of actions, clinical trial results, and side effects of the newer drugs used for MS, are reviewed. IFN beta and glatiramer acetate were not included since they have clinical experience nearing 30 years.

Stearic acid based, systematically designed oral lipid nanoparticles for enhanced brain delivery of dimethyl fumarate

Aim: Dimethyl fumarate is a frequent prescription for the management of numerous neurological disorders. Despite immense promises, DMF is associated with various problems such as multiple dosing (2–3 oral doses daily) and lower brain permeability. Our aim was to enhance the oral bioavailability and increase the brain concentrations of dimethyl fumarate. Methods: Solid lipid nanoparticles were systematically formulated by optimizing the composition based on the desired attributes viz. particle size, entrapment efficiency and amount of drug released in 6 h. Results & conclusion: The developed system offered nanometric particle size with entrapment efficiency > 90%. Enhanced Caco-2 cells cellular uptake by optimized solid lipid nanoparticless with superior pharmacokinetic and higher brain biodistribution were observed.

Activation of anti-oxidant Nrf2 signaling by enone analogues of curcumin

Inflammation and oxidative stress are common in many chronic diseases. Targeting signaling pathways that contribute to these conditions may have therapeutic potential. The transcription factor Nrf2 is a major regulator of phase II detoxification and anti-oxidant genes as well as anti-inflammatory and neuroprotective genes. Nrf2 is widespread in the CNS and is recognized as an important regulator of brain inflammation. The natural product curcumin exhibits numerous biological activities including ability to induce the expression of Nrf2-dependent phase II and anti-oxidant enzymes. Curcumin has been examined in a number of clinical studies with limited success, mainly owing to limited bioavailability and rapid metabolism. Enone analogues of curcumin were examined with an Nrf2 reporter assay to identify Nrf2 activators. Analogues were separated into groups with a 7-carbon dienone spacer, as found in curcumin; a 5-carbon enone spacer with and without a ring; and a 3-carbon enone spacer. Activators of Nrf2 were found in all three groups, many of which were more active than curcumin. Dose-response studies demonstrated that a range of substituents on the aromatic rings of these enones influenced not only the sensitivity to activation, reflected in EC₅₀ values, but also the extent of activation, which suggests that multiple mechanisms are involved in the activation of Nrf2 by these analogues.

Pharmacological targeting of GSK-3 and NRF2 provides neuroprotection in a preclinical model of tauopathy

Tauopathies are a group of neurodegenerative disorders where TAU protein is presented as aggregates or is abnormally phosphorylated, leading to alterations of axonal transport, neuronal death and neuroinflammation. Currently, there is no treatment to slow progression of these diseases. Here, we have investigated whether dimethyl fumarate (DMF), an inducer of the transcription factor NRF2, could mitigate tauopathy in a mouse model. The signaling pathways modulated by DMF were also studied in mouse embryonic fibroblast (MEFs) from wild type or KEAP1-deficient mice. The effect of DMF on neurodegeneration, astrocyte and microglial activation was examined in Nrf2^+/+ and Nrf2^−/− mice stereotaxically injected in the right hippocampus with an adeno-associated vector expressing human TAU^P301L and treated daily with DMF (100 mg/kg, i.g) during three weeks. DMF induces the NRF2 transcriptional through a mechanism that involves KEAP1 but also PI3K/AKT/GSK-3-dependent pathways. DMF modulates GSK-3β activity in mouse hippocampi. Furthermore, DMF modulates TAU phosphorylation, neuronal impairment measured by calbindin-D28K and BDNF expression, and inflammatory processes involved in astrogliosis, microgliosis and pro-inflammatory cytokines production. This study reveals neuroprotective effects of DMF beyond disruption of the KEAP1/NRF2 axis by inhibiting GSK3 in a mouse model of tauopathy. Our results support repurposing of this drug for treatment of these diseases.

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DMF mechanisms of action are partially KEAP1-dependent.

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Modulation of GSK-3β phosphorylation by DMF.

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DMF modulates TAU hyperphosphorylation in a tauopathy mouse model.

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DMF attenuates hippocampal neuronal damage, astrogliosis and microgliosis.

Donor variability may mask dimethyl fumarate's effects on nuclear factor E2-related factor 2 in human peripheral blood mononuclear cells

OBJECTIVE

Dimethyl fumarate (DMF) is an anti-inflammatory and antioxidant drug used to treat multiple sclerosis, but its mechanism(s) of action are not fully understood. In central nervous system (CNS) cells, DMF activates nuclear factor E2-related factor 2 (Nrf2), perhaps ameliorating oxidative stress-induced damage. However, it is not known whether DMF also activates Nrf2 in peripheral immune cells, which are known to participate in CNS demyelination. We conducted a single observation study to determine whether DMF can activate Nrf2 in peripheral immune cells in vitro.

RESULTS

We performed enzyme-linked immunosorbent assays to measure Nrf2 activation in nuclear extracts of human peripheral blood mononuclear cells treated with DMF at time points from 0 to 6 h, initially determining that DMF did not activate Nrf2, and that the mechanism(s) of action of DMF may thus differ in the periphery compared to the CNS. However, further analyses of our data suggest that high T_max variability is masking Nrf2 activation in individual donors. Additionally, there may be sub-populations of responders, perhaps related to genetic polymorphisms in Nrf2.

A potent small-molecule inhibitor of the DCN1-UBC12 interaction that selectively blocks cullin 3 neddylation

The Cullin-RING E3 ubiquitin ligases (CRLs) regulate homeostasis of ~20% of cellular proteins and their activation require neddylation of their cullin subunit. Cullin neddylation is modulated by a scaffolding DCN protein through interactions with both the cullin protein and an E2 enzyme such as UBC12. Here we report the development of DI-591 as a high-affinity, cell-permeable small-molecule inhibitor of the DCN1–UBC12 interaction. DI-591 binds to purified recombinant human DCN1 and DCN2 proteins with K_i values of 10–12 nM, and disrupts the DCN1–UBC12 interaction in cells. Treatment with DI-591 selectively converts cellular cullin 3 into an un-neddylated inactive form with no or minimum effect on other cullin members. Our data firmly establish a previously unrecognized specific role of the DCN1–UBC12 interaction for cellular neddylation of cullin 3. DI-591 is an excellent probe compound to investigate the role of the cullin 3 CRL ligase in biological processes and human diseases.

Cullins are central components of the ubiquitin-proteosome system and are activated via a neddylation process mediated by the DCN1–UBC12 complex. Here, the authors develop a small molecule inhibitor of the DCN1–UBC12 interaction that specifically blocks cullin 3 neddylation and can be used to probe the cellular function of cullin 3.

Impaired T-cell migration to the CNS under fingolimod and dimethyl fumarate

Objective:

To evaluate the long-term effects of treatments used in MS on the T-cell trafficking profile.

Methods:

We enrolled 83 patients with MS under fingolimod (FTY), natalizumab (NTZ), dimethyl fumarate (DMF), or other disease-modifying treatments (DMTs). Blood was drawn before treatment onset and up to 36–48 months. The ex vivo expression of CNS-related integrins (α4β1 and α_L subunit of LFA-1) and the gut-related integrin (α4β7) was assessed using flow cytometry on CD4⁺ and CD8⁺ T cells. The adhesion profiles of CD3⁺ T cells to specific integrin ligands (vascular cell adhesion molecule-1 [VCAM-1], intercellular adhesion molecule-1 [ICAM-1], and mucosal vascular addressin cell adhesion molecule-1 [MAdCAM-1]) were measured in vitro before and after 12 and 36–48 months.

Results:

NTZ decreased the frequency of α4β1⁺ and α4β7⁺ integrin expressing T cells and the binding of these cells to VCAM-1 and MAdCAM-1, respectively. After 12 months, DMF induced a decreased frequency of α_L^highCD4⁺ T cells combined with reduced binding to ICAM-1. By contrast, with FTY, there was a doubling of the frequency of α4β1⁺ and α_L^high, but a decreased frequency of α4β7⁺ T cells. Strikingly, the binding of α4β1⁺, α4β7⁺, and to a lesser extent of α_L^high T cells to VCAM-1, MAdCAM-1, and ICAM-1, respectively, was decreased at month 12 under FTY treatment. The presence of manganese partially restored the binding of these T cells to VCAM-1 in vitro, suggesting that FTY interferes with integrin activation.

Conclusions:

In addition to NTZ, DMF and FTY but not other tested DMTs may also decrease T-cell–mediated immune surveillance of the CNS. Whether this mechanism may contribute to the onset of CNS opportunistic infections remains to be shown.

Britanin Ameliorates Cerebral Ischemia-Reperfusion Injury by Inducing the Nrf2 Protective Pathway

AIMS

Oxidative stress is considered the major cause of tissue injury after cerebral ischemia. The nuclear factor erythroid 2-related factor 2 (Nrf2) pathway is one of the most important defensive mechanisms against oxidative stresses and has been confirmed as a target for stroke treatment. Thus, we desired to find new Nrf2 activators and test their neuronal protective activity both in vivo and in vitro.

RESULTS

The herb-derived compound, Britanin, is a potent inducer of the Nrf2 system. Britanin can induce the expression of protective enzymes and reverse oxygen-glucose deprivation, followed by reperfusion (OGD-R)-induced neuronal injury in primary cortical neurons in vitro. Furthermore, the administration of Britanin significantly ameliorated middle cerebral artery occlusion-reperfusion (MCAO-R) insult in vivo. We report here the crystal structure of the complex of Britanin and the BTB domain of Keap1. Britanin selectively binds to a conserved cysteine residue, cysteine 151, of Keap1 and inhibits Keap1-mediated ubiquitination of Nrf2, leading to induction of the Nrf2 pathway.

INNOVATION

Britanin is a potent inducer of Nrf2. The complex crystal structure of Britanin and the BTB domain of Keap1 help clarify the mechanism of Nrf2 induction. Britanin was proven to protect primary cortical neurons against OGD-R-induced injury in an Nrf2-dependant way. Additionally, Britanin had excellent cerebroprotective effect in an MCAO-R model.

CONCLUSION

Our results demonstrate that the natural product Britanin with potent Nrf2-activating and neural protective activities both in vitro and in vivo could be developed into a cerebroprotective therapeutic agent. Antioxid. Redox Signal. 27, 754-768.

The Neuroprotective Effect of Dimethyl Fumarate in an MPTP-Mouse Model of Parkinson's Disease: Involvement of Reactive Oxygen Species/Nuclear Factor-κB/Nuclear Transcription Factor Related to NF-E2

AIM

Oxidative stress plays a key role in Parkinson disease (PD), and nuclear transcription factor related to NF-E2 (Nrf-2) is involved in neuroprotection against PD. The aim of the present study was to investigate a role for nuclear factor-κB (NF-κB)/Nrf-2 in the neurotherapeutic action of dimethyl fumarate (DMF) in a mouse model of PD and in vitro in SHSY-5Y cells.

RESULTS

Daily oral gavage of DMF (10, 30, and 100 mg/kg) significantly reduced neuronal cell degeneration of the dopaminergic tract and behavioral impairments induced by four injections of the dopaminergic neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. Moreover, treatment with DMF prevented dopamine depletion, increased tyrosine hydroxylase and dopamine transporter activities, and also reduced the number of α-synuclein-positive neurons. Furthermore, DMF treatment upregulated the Nrf-2 pathway, increased NeuN⁺/Nrf-2⁺ cell number in the striatum, induced activation of manganese superoxide dismutase and heme oxygenase-1, and regulated glutathione levels. Moreover, DMF reduced interleukin 1 levels, cyclooxygenase 2 activity, and nitrotyrosine neuronal nitrite oxide synthase expression. This treatment also modulated microglia activation, restored nerve growth factor levels, and preserved microtubule-associated protein 2 alterations. The protective effects of DMF treatment, via Nrf-2, were confirmed in in vitro studies, through inhibition of Nrf-2 by trigonelline.

INNOVATION

These findings demonstrate that DMF, both in a mouse model of PD and in vitro, provides, via regulation of the NF-κB/Nrf-2 pathway, novel cytoprotective modalities that further augment the natural antioxidant response in neurodegenerative and inflammatory disease models.

CONCLUSION

These results support the thesis that DMF may constitute a promising therapeutic target for the treatment of PD. Antioxid. Redox Signal. 27, 453-471.

The sequence of disease-modifying therapies in relapsing multiple sclerosis: safety and immunologic considerations

The treatment landscape for relapsing forms of multiple sclerosis (RMS) has expanded considerably over the last 10 years with the approval of multiple new disease-modifying therapies (DMTs), and others in late-stage clinical development. All DMTs for RMS are believed to reduce central nervous system immune-mediated inflammatory processes, which translate into demonstrable improvement in clinical and radiologic outcomes. However, some DMTs are associated with long-lasting effects on the immune system and/or serious adverse events, both of which may complicate the use of subsequent therapies. When customizing a treatment program, a benefit–risk assessment must consider multiple factors, including the efficacy of the DMT to reduce disease activity, the short- and long-term safety and immunologic profiles of each DMT, the criteria used to define switching treatment, and the risk tolerance of each patient. A comprehensive benefit–risk assessment can only be achieved by evaluating the immunologic, safety, and efficacy data for DMTs in the controlled clinical trial environment and the postmarketing clinical practice setting. This review is intended to help neurologists make informed decisions when treating RMS by summarizing the known data for each DMT and raising awareness of the multiple considerations involved in treating people with RMS throughout the entire course of their disease.

Transdermal delivery of dimethyl fumarate for Alzheimer's disease: Effect of penetration enhancers

Dimethyl fumarate (DMF) is an orally administered drug with neuroprotective and immunomodulatory activities. It has potential uses in the treatment of neurodegenerative diseases such as Alzheimer's disease (AD). The objective of this study was to investigate the feasibility of transdermal delivery of DMF by studying the effect of different penetration enhancers on the skin permeation of DMF. The permeation of saturated DMF solutions was investigated in propylene glycol (PG) with varying concentrations of each of the following enhancers: Polysorbate 80 (T80), N-methyl pyrrolidone (NMP), laurocapram (Azone^®) (Az), Transcutol P (Tc), Terpineol (Terp), and cineole (Cin) using vertical Franz diffusion cells and human cadaver skin. The results showed that all penetration enhancers improved the rate of permeation of DMF. The rank order for the highest concentration of each enhancer was as follows: Cin > Az>TC > Terp>T80≥NMP. The most effective penetration enhancer was shown to be 5% cineole with a 5.3-fold increase in the enhancement ratio (ER). The amounts of drug delivered suggest that DMF is a potential candidate for transdermal drug delivery.

Vitamin-Derived Nanolipoidal Carriers for Brain Delivery of Dimethyl Fumarate: A Novel Approach with Preclinical Evidence

Various oral treatment options have been reported for relapsing multiple sclerosis. Recently, dimethyl fumarate (DMF) has been approved for the management of the same. Though effective, DMF is associated with concerns like multiple dosing, patient incompliance, gastrointestinal flushing, lower brain permeation, and economic hurdles. Henceforth, the objective of the present study was to develop vitamin-based solid lipid nanoparticles (SLNs) for effective brain delivery of DMF with a promise of once-a-day dosing. The developed SLNs were characterized for micromeritics, morphology, entrapment efficiency, drug loading and in vitro drug release. Caco-2 and SH-SY5Y cell lines were used to assess the intestinal permeability and neuronal uptake. Pharmacokinetic and biodistribution studies were performed on rats. The developed nanometeric lipidparticles were able to control the drug release and substantially enhance the Caco-2 as well as SH-5YSY cell permeability. The developed systems not only enhanced the oral bioavailability of the drug, but also offered substantially elevated brain drug levels to that of plain drug. The drug was protected from liver and biological residence was increased, indicating promising potential of the carriers in effective brain delivery of DMF. Enhanced bioavailability and elevated bioresidence of DMF by vitamin-based SLNs provided the evidence for once-a-day delivery potential for DMF in the management of neurological disorders.

Redox-based therapeutics in neurodegenerative disease

This review describes recent developments in the search for effective therapeutic agents that target redox homeostasis in neurodegenerative disease. The disruption to thiol redox homeostasis in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and multiple sclerosis is discussed, together with the experimental strategies that are aimed at preventing, or at least minimizing, oxidative damage in these diseases. Particular attention is given to the potential of increasing antioxidant capacity by targeting the Nrf2 pathway, the development of inhibitors of NADPH oxidases that are likely candidates for clinical use, together with strategies to reduce nitrosative stress and mitochondrial dysfunction. We describe the shortcomings of compounds that hinder their progression to the clinic and evaluate likely avenues for future research.

LINKED ARTICLES

This article is part of a themed section on Redox Biology and Oxidative Stress in Health and Disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.12/issuetoc.

Unlocking the potential of established products: toward new incentives rewarding innovation in Europe

Background: Many established products (EPs - marketed for eight years or more) are widely used off-label despite little evidence on benefit-risk ratio. This exposes patients to risks related to safety and lack of efficacy, and healthcare providers to liability. Introducing new indications for EPs may represent a high societal value; however, manufacturers rarely invest in R&D for EPs. The objective of this research was to describe incentives and disincentives for developing new indications for EPs in Europe and to investigate consequences of current policies. Methods: Targeted literature search and expert panel meetings. Results: Within the current European-level and national-level regulatory framework there are limited incentives for development of new indications with EPs. Extension of indication normally does not allow the price to be increased or maintained, the market protection period to be extended, or exclusion from a reference price system. New indication frequently triggers re-evaluation, resulting in price erosion, regardless of the level of added value with the new indication. In consequence, manufacturers are more prone to undertake R&D efforts at early to mid-stage of product life cycle rather than with EPs, or to invest in new chemical entities, even in therapeutic areas with broad off-label use. This represents a potentially missed opportunity as developing new indications for EPs offers an alternative to off-label use or lengthy and expensive R&D for new therapies, opens new opportunities for potentially cost-effective treatment alternatives, as well as greater equity in patients' access to treatment options. Conclusion: There are potential benefits from the development of new indications for EPs that are currently not being realized due to a lack of regulatory and pricing incentives in Europe. Incentives for orphan or paediatric drugs have proven to be effective in promoting R&D. Similarly, incentives to promote R&D in EPs should be developed, for the benefit of patients and healthcare systems.

Insight on the impacts of free amino acids and their metabolites on the immune system from a perspective of inborn errors of amino acid metabolism

INTRODUCTION

Amino acids (AAs) support a broad range of functions in living organisms, including several that affect the immune system. The functions of the immune system are affected when free AAs are depleted or in excess because of external factors, such as starvation, or because of genetic factors, such as inborn errors of metabolism. Areas covered: In this review, we discuss the current insights into how free AAs affect immune responses. When possible, we make comparisons to known disease states resulting from inborn errors of metabolism, in which changed levels of AAs or AA metabolites provide insight into the impact of AAs on the human immune system in vivo. We also explore the literature describing how changes in AA levels might provide pharmaceutical targets for safe immunomodulatory treatment. Expert opinion: The impact of free AAs on the immune system is a neglected topic in most immunology textbooks. That neglect is undeserved, because free AAs have both direct and indirect effects on the immune system. Consistent choices of pre-clinical models and better strategies for creating formulations are required to gain clinical impact.

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.

Non-canonical activation of NRF2: New insights and its relevance to disease

PURPOSE OF REVIEW

The goal of this review is to summarize the current knowledge in the field regarding the non-canonical activation of the NRF2 pathway. Specifically, we address what role p62 plays in mediating this pathway, which pathologies have been linked to the p62-dependent activation of NRF2, as well as what therapeutic strategies could be used to treat diseases associated with the non-canonical pathway.

RECENT FINDINGS

It has recently been shown that autophagic dysfunction leads to the aggregation or autophagosomal accumulation of p62, which sequesters KEAP1, resulting in prolonged activation of NRF2. The ability of p62 to outcompete NRF2 for KEAP1 binding depends on its abundance, or post-translational modifications to its key domains. Furthermore, the relevance of the p62-dependent activation of NRF2 in disease has been demonstrated in human hepatocellular carcinomas, as well as neurodegenerative diseases.

SUMMARY

These findings indicate that targeting p62, or the enzymes that modify it, could prove to be an advantageous strategy for treating diseases associated with autophagy dysregulation and prolonged activation of NRF2. Other therapeutic possibilities include restoring proper autophagic function, or directly inhibiting NRF2 or its targets, to restore redox and metabolic homeostasis. Future studies will help further clarify the mechanisms, regulation, and relevance of the non-canonical pathway in driving disease pathogenesis.

Enhanced Brain Delivery of Dimethyl Fumarate Employing Tocopherol-Acetate-Based Nanolipidic Carriers: Evidence from Pharmacokinetic, Biodistribution, and Cellular Uptake Studies

Dimethyl fumarate (DMF) is an approved drug for the management of relapsing multiple sclerosis. Despite efficacy, DMF is also reported to be a challenging drug owing to concerns like gastrointestinal tract flushing, multiple dosing, lower brain permeability, less patient compliance, and economic hurdles. The present study aims to develop DMF-tocopherol acetate nanolipidic carrier (NLCs) to enhance brain permeability and improve the gastric tolerance. The developed DMF-tocopherol acetate NLCs offered an average size of 69.70 nm, PDI of 0.317, and a zeta potential of -9.71 mV. Higher drug entrapment (90.12%) and drug loading (20.13%) assured controlled drug release behavior both in gastric and intestinal pH. Cellular uptake studies on Caco-2 and SH-SY5Y monolayers confirmed better intestinal absorption and neuronal uptake of the developed system, which was further corroborated by the pharmacokinetic and biodistribution studies. The oral bioavailability was enhanced by 4.09 times and brain availability was substantially improved vis-à-vis plain drug. The findings are promising and offer preclinical evidence for better brain availability of DMF, which can be exploited in the better management of diseases like multiple sclerosis.

The NmrA-like family domain containing 1 pseudogene Loc344887 is amplified in gallbladder cancer and promotes epithelial-mesenchymal transition

The expression pattern and biological role of long non-coding RNA (lncRNA) in cancer has been reported to be involved in many cancers. Here, we report the expression and biological role of a newly discovered lncRNA NmrA-like family domain containing 1 pseudogene (Loc344887) in gallbladder cancer (GBC). In this study, we found that the expression of Loc344887 was significantly elevated in GBC tissues and cell lines when compared with matched normal tissues and normal epithelial bile duct cell line, respectively. High Loc344887 was associated with larger tumor size. Loc344887 was upregulated significantly after ectopic expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) in GBC cells. Downregulation of Loc344887 in GBC cells suppressed cell proliferation, blocked cells in G0/S phase, and decreased the migration and invasion cell numbers. In addition, downregulation of Loc344887 decreased the expression of transcription factor Twist, mesenchymal marker Vimentin, and N-cadherin and increased the expression of epithelial maker E-cadherin, which could prompt a mesenchymal-to-epithelial transition phenotype. These results demonstrated that Loc344887 might contribute to cell proliferation and epithelial-to-mesenchymal transition process in GBC, which might be a potential therapeutic target.

[Monitoring of blood parameters under course-modified MS therapy : Substance-specific relevance and current recommendations for action]

With the approval of various substances for the immunotherapy of multiple sclerosis (MS), treatment possibilities have improved significantly over the last few years. Indeed, the choice of individually tailored preparations and treatment monitoring for the treating doctor is becoming increasingly more complex. This is particularly applicable for monitoring for a treatment-induced compromise of the immune system. The following article by members of the German Multiple Sclerosis Skills Network (KKNMS) and the task force "Provision Structures and Therapeutics" summarizes the practical recommendations for approved immunotherapy for mild to moderate and for (highly) active courses of MS. The focus is on elucidating the substance-specific relevance of particular laboratory parameters with regard to the mechanism of action and the side effects profile. To enable appropriate action to be taken in clinical practice, any blood work changes that can be expected, in addition to any undesirable laboratory findings and their causes and relevance, should be elucidated.

Comparative effectiveness using a matching-adjusted indirect comparison between delayed-release dimethyl fumarate and fingolimod for the treatment of multiple sclerosis

OBJECTIVE

Delayed-release dimethyl fumarate (DMF; also known as gastro-resistant DMF) and fingolimod are approved oral disease-modifying treatments for relapsing-remitting multiple sclerosis. In phase 3 trials, DMF (DEFINE/CONFIRM) and fingolimod (FREEDOMS/FREEDOMS II) resulted in significant reductions in clinical and magnetic resonance imaging activity, with acceptable safety profiles. Direct comparisons of these treatments are not possible due to a lack of head-to-head trials. We compared 2 year efficacy of DMF versus fingolimod at the approved dosage using a matching-adjusted indirect approach.

RESEARCH DESIGN AND METHODS

Individual patient data from DEFINE and CONFIRM, and aggregate data from FREEDOMS and FREEDOMS II, were pooled and compared using the matching-adjusted in-direct method. To account for cross-trial differences, data from trials with available individual patient data were adjusted to match aggregate data (i.e. average patient characteristics) from trials without patient-level data. Data from DMF-treated patients were weighted such that average baseline characteristics matched those of fingolimod-treated patients. After matching, weighted treatment outcomes for DMF-treated patients (240 mg twice daily) were compared with summary outcomes for fingolimod-treated patients (0.5 mg once daily). All comparison results of DMF versus fingolimod used fingolimod as the reference.

RESULTS

After matching, baseline characteristics were balanced between DMF and fingolimod. At year 2, the efficacy of DMF was similar to that of fingolimod for annualized relapse rate (rate ratio [95% confidence interval (CI)]: 1.11 [0.88, 1.40]), 12 week confirmed disability progression (hazard ratio [95% CI]: 0.90 [0.63, 1.29]), and Multiple Sclerosis Functional Composite (mean difference [95% CI]: 0.04 [-0.05, 0.13]). For patient-reported outcomes (EuroQoL 5-Dimensions questionnaire), the mean differences (95% CI) were 0.05 (0.01, 0.08) for utility score and 3.22 (0.58, 5.86) for visual analog scale score, significantly favoring DMF. There was no significant difference in the percentage of patients with no evidence of disease activity (NEDA) for DMF versus fingolimod among matching-adjusted patients with complete NEDA data: rate ratio (95% CI): 0.92 (0.51, 1.64).

CONCLUSIONS

Using the matching-adjusted indirect comparison approach, the efficacy of DMF and fingolimod were similar on all clinical outcomes, while patient-reported outcomes showed greater benefit with DMF. Study limitations include possible confounding from unobserved/unknown differences between trials, and trial length may have been insufficient to detect significant differences on disability progression.

CLINICAL TRIAL REGISTRATION

NCT00420212 (DEFINE); NCT00451451 (CONFIRM); NCT00289978 (FREEDOMS); NCT00355134 (FREEDOMS II).

Update on disease-modifying therapies for multiple sclerosis

Multiple sclerosis (MS) is an autoimmune, demyelinating disease of the central nervous system (CNS). It predominantly affects young women and is one of the most common causes of disability in young adults. MS is characterized by formation of white matter lesions in the CNS as a result of inflammation, demyelination, and axonal loss. Treatment has been a focus of neurological research for over 60 years. A number of disease-modifying therapies (DMTs) have become available making MS a treatable disease. These compounds target the inflammatory response in MS. They work by decreasing the chances of relapse, decreasing the chances of new lesion formation seen on MRI of the CNS and slowing the accumulation of disability. The first drugs for MS to be available were interferon-β and glatiramer acetate. These work by modulating the inflammatory response via different mechanisms that are briefly discussed. Newer agents have since become available and have significantly changed the dynamics of MS treatment. These include fingolimod, dimethyl fumarate and teriflunomide, which are oral agents. Other second-line and third-line Food and Drug Administration (FDA) approved medications include natalizumab and alemtuzumab. Natalizumab is considered one of the most potent treatments for relapse prevention. However, the high risk of progressive multifocal leukoencephalopathy (PML), which is caused by JC virus infection in the brain, tempers the more widespread use of this agent; nevertheless, JC virus antibody tests have helped to stratify the risk of PML. Alemtuzumab, which also has a considerable side effect profile, is likewise highly efficacious. Ocrelizumab, a monoclonal antibody to CD20 on B cells, is a highly effective agent for MS that is likely to be approved soon by the FDA. MS is a major contributor to healthcare costs and it is critical that healthcare providers be aware of the availability and benefits of DMTs. It is imperative that prompt and adequate treatment be established on diagnosis. Changes in therapy should be considered when there is evidence of disease activity as well as accumulation of disability or safety or tolerability concerns.

Activation of anti-oxidant Nrf2 signaling by substituted trans stilbenes

Nrf2, which is a member of the cap'n'collar family of transcription factors, is a major regulator of phase II detoxification and anti-oxidant genes as well as anti-inflammatory and neuroprotective genes. The importance of inflammation and oxidative stress in many chronic diseases supports the concept that activation of anti-oxidant Nrf2 signaling may have therapeutic potential. A number of Nrf2 activators have entered into clinical trials. Nrf2 exists in the cytosol in complex with its binding partner Keap1, which is a thiol-rich redox-sensing protein. In response to oxidative and electrophilic stress, select cysteine residues of Keap1 are modified, which locks Keap1 in the Nrf2-Keap1 complex and allows newly synthesized Nrf2 to enter the nucleus. Numerous Nrf2-activating chemicals, including a number of natural products, are electrophiles that modify Keap1, often by Michael addition, leading to activation of Nrf2. One concern with the design of Nrf2 activators that are electrophilic covalent modifiers of Keap1 is the issue of selectivity. In the present study, substituted trans stilbenes were identified as activators of Nrf2. These activators of Nrf2 are not highly electrophilic and therefore are unlikely to activate Nrf2 through covalent modification of Keap1. Dose-response studies demonstrated that a range of substituents on either ring of the trans stilbenes, especially fluorine and methoxy substituents, influenced not only the sensitivity to activation, reflected in EC₅₀ values, but also the extent of activation, which suggests that multiple mechanisms are involved in the activation of Nrf2. The stilbene backbone appears to be a privileged scaffold for development of a new class of Nrf2 activators.

Multiple sclerosis: Therapeutic applications of advancing drug delivery systems

Multiple sclerosis (MS) is an inflammatory autoimmune disease of the central nervous system, which is accompanying with demyelination, neurodegeneration and sensibility to oxidative stress. In MS, auto-reactive lymphocytes cross the blood-brain barrier (BBB) and reside in the perivenous demyelinating lesions which create various distinct inflammatory demyelinated plaques situated predominantly in the white matter. The current MS-related therapeutic approaches can be classified into disease-modifying therapies (DMTs) and symptomatic therapy. DMTs suppress circulating immune cells, inhibit passing the BBB and decrease the inflammatory responses. Recent advances have remarkably delayed disease development and improved the quality of life for numerous patients. In spite of major improvements in therapeutic options, there are some limitations regarding the routes of administration and the necessity for repeated and long-term dosing in which cause to systemic disadvantageous consequences and patient non-compliance. Nanotechnology presents promising approaches to improve autoimmune disease treatment with the capability to overcome many of the limitations common to the current immunosuppressive and biological therapies. Here we emphasis on nanomedicine-based drug delivery approaches of biological immunomodulatory mediators for the treatment of multiple sclerosis. This comprehensive review details the most successful drugs in MS therapy and also focuses on conceptions and clinical potential of novel nanomedicine attitudes for inducing immunosuppression and immunological tolerance in MS to modulate abnormal and pathologic immune responses.

Oral Monomethyl Fumarate Therapy Ameliorates Retinopathy in a Humanized Mouse Model of Sickle Cell Disease

AIMS

Sickle retinopathy (SR) is a major cause of blindness in sickle cell disease (SCD). The genetic mutation responsible for SCD is known, however; oxidative stress and inflammation also figure prominently in the development and progression of pathology. Development of therapies for SR is hampered by the lack of (a) animal models that accurately recapitulate human SR and (b) strategies for noninvasive yet effective retinal drug delivery. This study addressed both issues by validating the Townes humanized SCD mouse as a model of SR and demonstrating the efficacy of oral administration of the antioxidant fumaric acid ester monomethyl fumarate (MMF) in the disease.

RESULTS

In vivo ophthalmic imaging, electroretinography, and postmortem histological RNA and protein analyses were used to monitor retinal health and function in normal (HbAA) and sickle (HbSS) hemoglobin-producing mice over a one-year period and in additional HbAA and HbSS mice treated with MMF (15 mg/ml) for 5 months. Functional and morphological abnormalities and molecular hallmarks of oxidative stress/inflammation were evident early in HbSS retinas and increased in number and severity with age. Treatment with MMF, a known inducer of Nrf2, induced γ-globin expression and fetal hemoglobin production, improved hematological profiles, and ameliorated SR-related pathology. Innovation and Conclusion: United States Food and Drug Administration-approved formulations in which MMF is the primary bioactive ingredient are currently available to treat multiple sclerosis; such drugs may be effective for treatment of ocular and systemic complications of SCD, and given the pleiotropic effects, other nonsickle-related diseases in which oxidative stress, inflammation, and retinal vascular pathology figure prominently. Antioxid. Redox Signal. 25, 921-935.

Anti-inflammatory activity of Barleria lupulina: Identification of active compounds that activate the Nrf2 cell defense pathway, organize cortical actin, reduce stress fibers, and improve cell junctions in microvascular endothelial cells

ETHNOPHARMACOLOGICAL RELEVANCE

Hot aqueous extracts of the plant Barleria lupulina (BL) are used for treating inflammatory conditions and diabetic vascular complications.

AIM OF THE STUDY

The goal was to identify active compounds in hot aqueous extracts of BL (HAE-BL) that are consistent with a role in reducing inflammation and reducing the vascular pathology associated with diabetes. In particular, we examined activation of the Nrf2 cell defense pathway because our initial findings indicated that HAE-BL activates Nrf2, and because Nrf2 is known to suppress inflammation. Activation of Nrf2 by HAE-BL has not been described previously.

MATERIALS AND METHODS

Human endothelial cells, real-time PCR, western blotting, cytoskeletal analyses, and assay-guided fractionation with HPLC were used to identify specific compounds in HAE-BL that activate the Nrf2 cell defense pathway and reduce markers of inflammation in vitro.

RESULTS

HAE-BL potently activated the Nrf2 cell defense pathway in endothelial cells consistent with its traditional use and reported success in reducing inflammation. Assay guided fractionation with HPLC identified three alkyl catechols: 4-ethylcatechol, 4-vinylcatechol, and 4-methylcatechol, that are each potent Nrf2 activators. In addition to activating Nrf2, HAE-BL and akyl catechols each profoundly improved organization of the endothelial cell actin cytoskeleton, reduced actin stress fibers, organized cell-cell junctions, and induced expression of mRNA encoding claudin-5 that is important for formation of endothelial tight junctions and reducing vascular leak.

CONCLUSIONS

HAE-BL contains important alkyl catechols that potently activate the Nrf2 cell defense pathway, improve organization of the endothelial cell cytoskeleton, and organize tight cell junctions. All of these properties are consistent with a role in reducing inflammation and reducing vascular leak. Because activation of the Nrf2 cell defense pathway also prevents cancers, neuro-degeneration, age-related macular degeneration, and also reduces the severity of chronic obstructive pulmonary disorder and multiple sclerosis, HAE-BL warrants additional consideration for these other serious disorders.

T-REX on-demand redox targeting in live cells

This protocol describes targetable reactive electrophiles and oxidants (T-REX)-a live-cell-based tool designed to (i) interrogate the consequences of specific and time-resolved redox events, and (ii) screen for bona fide redox-sensor targets. A small-molecule toolset comprising photocaged precursors to specific reactive redox signals is constructed such that these inert precursors specifically and irreversibly tag any HaloTag-fused protein of interest (POI) in mammalian and Escherichia coli cells. Syntheses of the alkyne-functionalized endogenous reactive signal 4-hydroxynonenal (HNE(alkyne)) and the HaloTag-targetable photocaged precursor to HNE(alkyne) (also known as Ht-PreHNE or HtPHA) are described. Low-energy light prompts photo-uncaging (t1/2 <1-2 min) and target-specific modification. The targeted modification of the POI enables precisely timed and spatially controlled redox events with no off-target modification. Two independent pathways are described, along with a simple setup to functionally validate known targets or discover novel sensors. T-REX sidesteps mixed responses caused by uncontrolled whole-cell swamping with reactive signals. Modification and downstream response can be analyzed by in-gel fluorescence, proteomics, qRT-PCR, immunofluorescence, fluorescence resonance energy transfer (FRET)-based and dual-luciferase reporters, or flow cytometry assays. T-REX targeting takes 4 h from initial probe treatment. Analysis of targeted redox responses takes an additional 4-24 h, depending on the nature of the pathway and the type of readouts used.

The multifaceted role of Nrf2 in mitochondrial function

The transcription factor nuclear factor erythroid 2 p45-related factor 2 (Nrf2) is the master regulator of the cellular redox homeostasis. Nrf2 target genes comprise of a large network of antioxidant enzymes, proteins involved in xenobiotic detoxification, repair and removal of damaged proteins, inhibition of inflammation, as well as other transcription factors. In recent years it has emerged that as part of its role as a regulator of cytoprotective gene expression, Nrf2 impacts mitochondrial function. Increased Nrf2 activity defends against mitochondrial toxins. Reduced glutathione, the principal small molecule antioxidant in the mammalian cell and a product of several of the downstream target genes of Nrf2, counterbalances mitochondrial ROS production. The function of Nrf2 is suppressed in mitochondria-related disorders, such as Parkinson's disease and Friedrich's ataxia. Studies using isolated mitochondria and cultured cells have demonstrated that Nrf2 deficiency leads to impaired mitochondrial fatty acid oxidation, respiration and ATP production. Small molecule activators of Nrf2 support mitochondrial integrity by promoting mitophagy and conferring resistance to oxidative stress-mediated permeability transition. Excitingly, recent studies have shown that Nrf2 also affects mitochondrial function in stem cells with implications for stem cell self-renewal, cardiomyocyte regeneration, and neural stem/progenitor cell survival.

Immunomodulatory Effects of 1,25-Dihydroxyvitamin D3 on Dendritic Cells Promote Induction of T Cell Hyporesponsiveness to Myelin-Derived Antigens

While emerging evidence indicates that dendritic cells (DC) play a central role in the pathogenesis of multiple sclerosis (MS), their modulation with immunoregulatory agents provides prospect as disease-modifying therapy. Our observations reveal that 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃) treatment of monocyte-derived DC results in a semimature phenotype and anti-inflammatory cytokine profile as compared to conventional DC, in both healthy controls and MS patients. Importantly, 1,25(OH)₂D₃-treated DC induce T cell hyporesponsiveness, as demonstrated in an allogeneic mixed leukocyte reaction. Next, following a freeze-thaw cycle, 1,25(OH)₂D₃-treated immature DC could be recovered with a 78% yield and 75% viability. Cryopreservation did not affect the expression of membrane markers by 1,25(OH)₂D₃-treated DC nor their capacity to induce T cell hyporesponsiveness. In addition, the T cell hyporesponsiveness induced by 1,25(OH)₂D₃-treated DC is antigen-specific and robust since T cells retain their capacity to respond to an unrelated antigen and do not reactivate upon rechallenge with fully mature conventional DC, respectively. These observations underline the clinical potential of tolerogenic DC (tolDC) to correct the immunological imbalance in MS. Furthermore, the feasibility to cryopreserve highly potent tolDC will, ultimately, contribute to the large-scale production and the widely applicable use of tolDC.

Advancing drug delivery systems for the treatment of multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease of the central nervous system. It is characterized by demyelination of neurons and loss of neuronal axons and oligodendrocytes. In MS, auto-reactive T cells and B cells cross the blood-brain barrier (BBB), causing perivenous demyelinating lesions that form multiple discrete inflammatory demyelinated plaques located primarily in the white matter. In chronic MS, cortical demyelination and progressive axonal transections develop. Treatment for MS can be stratified into disease-modifying therapies (DMTs) and symptomatic therapy. DMTs aim to decrease circulating immune cells or to prevent these cells from crossing the BBB and reduce the inflammatory response. There are currently 10 DMTs approved for the relapsing forms of MS; these vary with regard to their efficacy, route and frequency of administration, adverse effects, and toxicity profile. Better drug delivery systems are being developed in order to decrease adverse effects, increase drug efficacy, and increase patient compliance through the direct targeting of pathologic cells. Here, we address the uses and benefits of advanced drug delivery systems, including nanoparticles, microparticles, fusion antibodies, and liposomal formulations. By altering the properties of therapeutic particles and enhancing targeting, breakthrough drug delivery technologies potentially applicable to multiple disease treatments may rapidly emerge.

Role of Nrf2/HO-1 system in development, oxidative stress response and diseases: an evolutionarily conserved mechanism

The multifunctional regulator nuclear factor erythroid 2-related factor (Nrf2) is considered not only as a cytoprotective factor regulating the expression of genes coding for anti-oxidant, anti-inflammatory and detoxifying proteins, but it is also a powerful modulator of species longevity. The vertebrate Nrf2 belongs to Cap 'n' Collar (Cnc) bZIP family of transcription factors and shares a high homology with SKN-1 from Caenorhabditis elegans or CncC found in Drosophila melanogaster. The major characteristics of Nrf2 are to some extent mimicked by Nrf2-dependent genes and their proteins including heme oxygenase-1 (HO-1), which besides removing toxic heme, produces biliverdin, iron ions and carbon monoxide. HO-1 and their products exert beneficial effects through the protection against oxidative injury, regulation of apoptosis, modulation of inflammation as well as contribution to angiogenesis. On the other hand, the disturbances in the proper HO-1 level are associated with the pathogenesis of some age-dependent disorders, including neurodegeneration, cancer or macular degeneration. This review summarizes our knowledge about Nrf2 and HO-1 across different phyla suggesting their conservative role as stress-protective and anti-aging factors.

Repurposing the NRF2 Activator Dimethyl Fumarate as Therapy Against Synucleinopathy in Parkinson's Disease

AIMS

This preclinical study was aimed at determining whether pharmacological targeting of transcription factor NRF2, a master controller of many homeostatic genes, might provide a disease-modifying therapy in the animal model of Parkinson's disease (PD) that best reproduces the main hallmark of this pathology, that is, α-synucleinopathy, and associated events, including nigral dopaminergic cell death, oxidative stress, and neuroinflammation.

RESULTS

Pharmacological activation of NRF2 was achieved at the basal ganglia by repurposing dimethyl fumarate (DMF), a drug already in use for the treatment of multiple sclerosis. Daily oral gavage of DMF protected nigral dopaminergic neurons against α-SYN toxicity and decreased astrocytosis and microgliosis after 1, 3, and 8 weeks from stereotaxic delivery to the ventral midbrain of recombinant adeno-associated viral vector expressing human α-synuclein. This protective effect was not observed in Nrf2-knockout mice. In vitro studies indicated that this neuroprotective effect was correlated with altered regulation of autophagy markers SQTSM1/p62 and LC3 in MN9D, BV2, and IMA 2.1 and with a shift in microglial dynamics toward a less pro-inflammatory and a more wound-healing phenotype. In postmortem samples of PD patients, the cytoprotective proteins associated with NRF2 expression, NQO1 and p62, were partly sequestered in Lewy bodies, suggesting impaired neuroprotective capacity of the NRF2 signature.

INNOVATION

These experiments provide a compelling rationale for targeting NRF2 with DMF as a therapeutic strategy to reinforce endogenous brain defense mechanisms against PD-associated synucleinopathy.

CONCLUSION

DMF is ready for clinical validation in PD. Antioxid. Redox Signal. 25, 61-77.

Dimethyl fumarate activates the prostaglandin EP2 receptor and stimulates cAMP signaling in human peripheral blood mononuclear cells

Dimethyl fumarate (DMF) was recently approved by the FDA for the treatment of relapsing remitting MS. The pathology of MS is a result of both immune dysregulation and oxidative stress induced damage, and DMF is believed to have therapeutic effects on both of these processes. However, the mechanisms of action of DMF are not fully understood. To determine if DMF is able to activate signaling cascades that affect immune dysregulation, we treated human peripheral blood mononuclear cells with DMF. We discovered that DMF stimulates cyclic adenosine monophosphate (cAMP) production after 1 min treatment in vitro. cAMP is a small molecule second messenger that has been shown to modulate immune response. Using pharmacological inhibitors, we determined that adenylyl cyclase mediates DMF induced cAMP production; DMF activated the prostaglandin EP2 receptor to produce cAMP. This response was not due to increased endogenous production of prostaglandin E2 (PGE2), but was enhanced by addition of exogenous PGE2. Furthermore, we determined that the bioactive metabolite of DMF, monomethyl fumarate (MMF), also stimulates cAMP production. These novel findings suggest that DMF may provide protection against MS by inhibiting immune cell function via the cAMP signaling pathway.

Dimethyl fumarate attenuates experimental autoimmune neuritis through the nuclear factor erythroid-derived 2-related factor 2/hemoxygenase-1 pathway by altering the balance of M1/M2 macrophages

Background

Guillain–Barré syndrome (GBS) is an acute, post-infectious, immune-mediated, demyelinating disease of peripheral nerves and nerve roots. Dimethyl fumarate (DMF), a fumaric acid ester, exhibits various biological activities, including multiple immunomodulatory and neuroprotective effects. However, the potential mechanism underlying the effect of DMF in GBS animal model experimental autoimmune neuritis (EAN) is unclear.

Methods

Using EAN, an established GBS model, we investigated the effect of DMF by assessing clinical score, histological staining and electrophysiological studies. Then, we further explored the potential mechanism by Western blot analysis, flow cytometry, fluorescence immunohistochemistry, PCR, and ELISA analysis. The Mann–Whitney U test was used to compare differences between control group and treatment groups where appropriate.

Results

DMF treatment reduced the neurological deficits by ameliorating inflammatory cell infiltration and demyelination of sciatic nerves. In addition, DMF treatment decreased the level of pro-inflammatory M1 macrophages while increasing the number of anti-inflammatory M2 macrophages in the spleens and sciatic nerves of EAN rats. In RAW 264.7, a shift in macrophage polarization from M1 to M2 phenotype was demonstrated to be depended on DMF application. In sciatic nerves, DMF treatment elevated the level of the antioxidant transcription factor nuclear factor erythroid-derived 2-related factor 2 (Nrf2) and its target gene hemoxygenase-1 (HO-1) which could facilitate macrophage polarization toward M2 type. Moreover, DMF improved the inflammatory milieu in spleens of EAN rats, characterized by downregulation of messenger RNA (mRNA) of IFN-γ, TNF-α, IL-6, and IL-17 and upregulation of mRNA level of IL-4 and IL-10.

Conclusions

Taken together, our data demonstrate that DMF can effectively suppress EAN, and the mechanism involves altering the balance of M1/M2 macrophages and attenuating inflammation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-016-0559-x) contains supplementary material, which is available to authorized users.

Nano- and micro-based systems for immunotolerance induction in multiple sclerosis

It is estimated that more than 2.5 million individuals worldwide have multiple sclerosis (MS). MS is an autoimmune neurodegenerative disease resulting from the destruction of the myelin sheath that enwraps axons driven by an immune cell attack to the central nervous system. Current therapeutic programs for MS focus in immunosuppression and more recently in the use of immunomodulatory molecules. These therapeutic approaches provide significant improvements in the management of the disease, but are frequently associated with an increased susceptibility of opportunistic infection. In this commentary, we highlight the application of nano and micro-technologies as emerging and innovative solutions for MS therapy with the potential to restore immune homeostasis via antigen-specific interactions. Furthermore, we propose and discuss the usage of a minimally invasive approach, namely microneedle patches, as a new therapeutic route. Microneedle patches for the delivery of specific antigens to restore immunotolerance in the context of multiple sclerosis.

Microparticulate/Nanoparticulate Powders of a Novel Nrf2 Activator and an Aerosol Performance Enhancer for Pulmonary Delivery Targeting the Lung Nrf2/Keap-1 Pathway

This systematic and comprehensive study reports for the first time on the successful rational design of advanced inhalable therapeutic dry powders containing dimethyl fumarate, a first-in-class Nrf2 activator drug to treat pulmonary inflammation, using particle engineering design technology for targeted delivery to the lungs as advanced spray dried (SD) one-component DPIs. In addition, two-component co-spray dried (co-SD) DMF:D-Man DPIs with high drug loading were successfully designed for targeted lung delivery as advanced DPIs using organic solution advanced spray drying in closed mode. Regional targeted deposition using design of experiments (DoE) for in vitro predictive lung modeling based on aerodynamic properties was tailored based on composition and spray drying parameters. These findings indicate the significant potential of using D-Man in spray drying to improve particle formation and aerosol performance of small molecule with a relatively low melting point. These respirable microparticles/nanoparticles in the solid-state exhibited excellent aerosol dispersion performance with an FDA-approved human DPI device. Using in vitro predictive lung deposition modeling, the aerosol deposition patterns of these particles show the capability to reach lower airways to treat inflammation in this region in pulmonary diseases such as acute lung injury (ALI), chronic obstructive pulmonary disease (COPD), pulmonary hypertension (PH), and pulmonary endothelial disease.