A Sensitization-Free Dimethyl Fumarate Prodrug, Isosorbide Di-(Methyl Fumarate), Provides a Topical Treatment Candidate for Psoriasis

Comparative activity of dimethyl fumarate derivative IDMF in three models relevant to multiple sclerosis and psoriasis

Dimethyl fumarate (DMF) is an anti-inflammatory and immunoregulatory medication used to treat multiple sclerosis (MS) and psoriasis. Its skin sensitization property precludes its topical use, which is unfortunate for the treatment of psoriasis. Isosorbide di-(methyl fumarate) (IDMF), a novel derivative of DMF, was synthesized to circumvent this adverse reaction and unlock the potential of topical delivery, which could be useful for treating psoriasis in the subpopulation of psoriatic MS patients, as well as in the general population. Here, we compared its therapeutic potential of this non-sensitizing derivative with DMF and its therapeutic version Diroximel in three skin- and neuroinflammation models: the lck-GFP zebrafish, activated BV-2 murine microglia and human T-lymphocyte Jurkat cell line. The results provide a comparative evaluation of the bioactivity of these three related chemical entities in models relevant to skin and neuroinflammation and expose several therapeutic advantages unique to IDMF.

Nrf2-mediated ferroptosis inhibition: a novel approach for managing inflammatory diseases

Inflammatory diseases, including psoriasis, atherosclerosis, rheumatoid arthritis, and ulcerative colitis, are characterized by persistent inflammation. Moreover, the existing treatments for inflammatory diseases only provide temporary relief by controlling symptoms, and treatments of unstable and expensive. Therefore, new therapeutic solutions are urgently needed to address the underlying causes or symptoms of inflammatory diseases. Inflammation frequently coincides with a high level of (reactive oxygen species) ROS activation, serving as a fundamental element in numerous physiological and pathological phenotypes that can result in serious harm to the organism. Given its pivotal role in inflammation, oxidative stress, and ferroptosis, ROS represents a focal node for investigating the (nuclear factor E2-related factor 2) Nrf2 pathway and ferroptosis, both of which are intricately linked to ROS. Ferroptosis is mainly triggered by oxidative stress and involves iron-dependent lipid peroxidation. The transcription factor Nrf2 targets several genes within the ferroptosis pathway. Recent studies have shown that Nrf2 plays a significant role in three key ferroptosis-related routes, including the synthesis and metabolism of glutathione/glutathione peroxidase 4, iron metabolism, and lipid processes. As a result, ferroptosis-related treatments for inflammatory diseases have attracted much attention. Moreover, drugs targeting Nrf2 can be used to manage inflammatory conditions. This review aimed to assess ferroptosis regulation mechanism and the role of Nrf2 in ferroptosis inhibition. Therefore, this review article may provide the basis for more research regarding the treatment of inflammatory diseases through Nrf2-inhibited ferroptosis.

Sulforaphane alleviates psoriasis by enhancing antioxidant defense through KEAP1-NRF2 Pathway activation and attenuating inflammatory signaling

Psoriasis is a chronic inflammatory skin disease that affects millions of people worldwide. Sulforaphane (SFN) has been shown to have anti-inflammatory and antioxidant properties. In this study, we investigated the effects of SFN on a mouse model of psoriasis induced by imiquimod (IMQ) and its underlying molecular mechanism. Mice treated with SFN showed significant improvement in psoriatic symptoms, including reduced erythema, scales, and cutaneous thickness. Histopathological analysis and immunohistochemical staining revealed decreased expression of K16, K17, and Ki67 in SFN-treated mice, indicating reduced abnormal differentiation of keratinocytes and cutaneous inflammation. SFN treatment also reduced the activation of STAT3 and NF-κB pathways and downregulated pro-inflammatory cytokines IL-1β, IL-6, and CCL2. In vitro experiments using HaCaT cells demonstrated that SFN inhibited IL-22 and TNF-α-induced activation of inflammatory pathways and keratinocyte proliferation. Network pharmacology analysis suggested that the KEAP1-NRF2 pathway might be involved in the protective effects of SFN on psoriasis. We observed reduced NRF2 expression in human psoriatic lesions, and subsequent experiments showed that SFN activated KEAP1-NRF2 pathway in vivo and in vitro. Importantly, NRF2-deficient mice exhibited aggravated psoriasis-like symptoms and reduced response to SFN treatment. Our findings indicate that SFN ameliorates psoriasis symptoms and inflammation through the KEAP1-NRF2 pathway, suggesting a potential therapeutic role for SFN in the treatment of psoriasis.

Incorporation of an Isohexide Subunit Improves the Drug-like Properties of Bioactive Compounds

An enhanced ability to pre-engineer favorable drug-likeness qualities into bioactive molecules would focus and streamline the drug development process. We find that phenols, carboxylic acids, and a purine react with isosorbide ("GRAS" designated) under Mitsunobu coupling conditions to deliver the isoidide conjugates selectively and efficiently. Such conjugates show improved solubility and permeability properties compared with the bare scaffold compounds themselves, and the purine adduct may have applications as a 2'-deoxyadenosine isostere. We anticipate additional benefits, implied by their structures, in metabolic stability and reduced toxicity of the isoidide conjugates as well.

NRF2 in dermo-cosmetic: From scientific knowledge to skin care products

The skin is the organ that is most susceptible to the impact of the exposome. Located at the interface with the external environment, it protects internal organs through the barrier function of the epidermis. It must adapt to the consequences of the harmful effects of solar radiation, the various chemical constituents of atmospheric pollution, and wounds associated with mechanical damage: oxidation, cytotoxicity, inflammation, and so forth. In this biological context, a capacity to adapt to the various stresses caused by the exposome is essential; otherwise, more or less serious conditions may develop accelerated aging, pigmentation disorders, atopy, psoriasis, and skin cancers. Nrf2-controlled pathways play a key role at this level. Nrf2 is a transcription factor that controls genes involved in oxidative stress protection and detoxification of chemicals. Its involvement in UV protection, reduction of inflammation in processes associated with healing, epidermal differentiation for barrier function, and hair regrowth, has been demonstrated. The modulation of Nrf2 in the skin may therefore constitute a skin protection or care strategy for certain dermatological stresses and disorders initiated or aggravated by the exposome. Nrf2 inducers can act through different modes of action. Keap1-dependent mechanisms include modification of the cysteine residues of Keap1 by (pro)electrophiles or prooxidants, and disruption of the Keap1-Nrf2 complex. Indirect mechanisms are suggested for numerous phytochemicals, acting on upstream pathways, or via hormesis. While developing novel and safe Nrf2 modulators for skin care may be challenging, new avenues can arise from natural compounds-based molecular modeling and emerging concepts such as epigenetic regulation.

The Challenge of Dimethyl Fumarate Repurposing in Eye Pathologies

Dimethyl fumarate (DMF) is a small molecule currently approved and used in the treatment of psoriasis and multiple sclerosis due to its immuno-modulatory, anti-inflammatory, and antioxidant properties. As an Nrf2 activator through Keap1 protein inhibition, DMF unveils a potential therapeutical use that is much broader than expected so far. In this comprehensive review we discuss the state-of-art and future perspectives regarding the potential repositioning of this molecule in the panorama of eye pathologies, including Age-related Macular Degeneration (AMD). The DMF's mechanism of action, an extensive analysis of the in vitro and in vivo evidence of its beneficial effects, together with a search of the current clinical trials, are here reported. Altogether, this evidence gives an overview of the new potential applications of this molecule in the context of ophthalmological diseases characterized by inflammation and oxidative stress, with a special focus on AMD, for which our gene-disease (KEAP1-AMD) database search, followed by a protein-protein interaction analysis, further supports the rationale of DMF use. The necessity to find a topical route of DMF administration to the eye is also discussed. In conclusion, the challenge of DMF repurposing in eye pathologies is feasible and worth scientific attention and well-focused research efforts.

NRF2, a crucial modulator of skin cells protection against vitiligo, psoriasis, and cancer

The skin represents a physical barrier between the organism and the environment that has evolved to confer protection against biological, chemical, and physical insults. The inner layer, known as dermis, is constituted by connective tissue and different types of immune cells whereas the outer layer, the epidermis, is composed by different layers of keratinocytes and an abundant number of melanocytes, localized in the stratum basale of the epidermis. Oxidative stress is a common alteration of inflammatory skin disorders such as vitiligo, dermatitis, or psoriasis but can also play a causal role in skin carcinogenesis and tumor progression. Nuclear factor (erythroid-derived 2)-like 2 (NRF2) has emerged as a crucial regulator of cell defense mechanisms activating complex transcriptional programs that facilitate reactive oxygen species detoxification, repair oxidative damage and prevent xenobiotic-induced toxicity. Accumulating evidence suggests that the keratinocytes, melanocytes, and other skin cell types express high levels of NRF2, which is known to play a pivotal role in the skin homeostasis, differentiation, and metabolism during normal and pathologic conditions. In the present review, we summarize the current evidence linking NRF2 to skin pathophysiology and we discuss some recent modulators of NRF2 activity that have shown a therapeutic efficacy in skin protection against tumor initiation and common inflammatory skin conditions such as vitiligo or psoriasis, with a particular emphasis on natural compounds.

The Role of KEAP1-NRF2 System in Atopic Dermatitis and Psoriasis

The Kelch-like erythroid cell-derived protein with cap‘n’collar homology-associated protein 1 (KEAP1)-nuclear factor erythroid-2-related factor 2 (NRF2) system, a thiol-based sensor-effector apparatus, exerts antioxidative and anti-inflammatory effects and maintains skin homeostasis. Thus, NRF2 activation appears to be a promising treatment option for various skin diseases. However, NRF2-mediated defense responses may deteriorate skin inflammation in a context-dependent manner. Atopic dermatitis (AD) and psoriasis are two common chronic inflammatory skin diseases caused by a defective skin barrier, dysregulated immune responses, genetic predispositions, and environmental factors. This review focuses on the role of the KEAP1-NRF2 system in the pathophysiology of AD and psoriasis and the therapeutic approaches that utilize this system.

Transcriptomic Analysis of Fumarate Compounds Identifies Unique Effects of Isosorbide Di-(Methyl Fumarate) on NRF2, NF-kappaB and IRF1 Pathway Genes

Dimethyl fumarate (DMF) has emerged as a first-line therapy for relapsing-remitting multiple sclerosis (RRMS). This treatment, however, has been limited by adverse effects, which has prompted development of novel derivatives with improved tolerability. We compared the effects of fumarates on gene expression in astrocytes. Our analysis included diroximel fumarate (DRF) and its metabolite monomethyl fumarate (MMF), along with a novel compound isosorbide di-(methyl fumarate) (IDMF). Treatment with IDMF resulted in the largest number of differentially expressed genes. The effects of DRF and MMF were consistent with NRF2 activation and NF-κB inhibition, respectively. IDMF responses, however, were concordant with both NRF2 activation and NF-κB inhibition, and we confirmed IDMF-mediated NF-κB inhibition using a reporter assay. IDMF also down-regulated IRF1 expression and IDMF-decreased gene promoters were enriched with IRF1 recognition sequences. Genes altered by each fumarate overlapped significantly with those near loci from MS genetic association studies, but IDMF had the strongest overall effect on MS-associated genes. These results show that next-generation fumarates, such as DRF and IDMF, have effects differing from those of the MMF metabolite. Our findings support a model in which IDMF attenuates oxidative stress via NRF2 activation, with suppression of NF-κB and IRF1 contributing to mitigation of inflammation and pyroptosis.