Dimethyl Fumarate Alleviates Dextran Sulfate Sodium-Induced Colitis, through the Activation of Nrf2-Mediated Antioxidant and Anti-inflammatory Pathways

Protective effect of dimethyl fumarate against ethanol-provoked gastric ulcers in rats via regulation of HMGB1/TLR4/NF-κB, and PPARγ/SIRT1/Nrf2 pathways: Involvement of miR-34a-5p

Aberration of the gastric mucosal barrier homeostasis circuit is one of the key features linked to the onset of gastric ulcers (GU). This work aimed to inspect the gastroprotective influence of dimethyl fumarate (DMF) on ethanol-induced GU in rats and to decipher the possible mechanisms entailed. Rats were pretreated with either DMF (80 mg/kg) or omeprazole (OMP) (20 mg/kg) by oral gavage for 2 weeks. After 24 h of starvation, ethanol (5 ml/kg, oral) was employed to trigger GU in rats, while carboxymethyl cellulose (CMC) was used as a control. Ethanol notably elevated both macroscopic and microscopic gastric damage. DMF and OMP exhibited similar effects on gastric ulcer healing. DMF intervention led to a substantial improvement in gastric insults. DMF significantly reduced ethanol-triggered gastric lesions, as manifested by decreased gastric secretion, acidity, ulcer surface area percent, reduced leukocyte incursion, and increased mucus percent. DMF upregulated miR-34a-5p expression concomitant with the suppression of high mobility group box1 (HMGB1) and inflammatory responses in gastric mucosal homogenate. DMF improved GU by restoring reduced antioxidant defense mechanisms through the coactivation of nuclear factor erythroid 2-related factor-2 (Nrf2), peroxisome proliferator-activated receptor gamma (PPARγ), and sirtuin1 (SIRT1), indicating the protective role of the PPARγ/SIRT1/Nrf2 pathway. Intriguingly, DMF mitigated apoptosis in ethanol-elicited GU. Taken together, this research implies the potential for the repurposing of DMF as an innovative gastroprotective medication to reestablish the balance of the gastric mucosal barrier via the attenuation of gastric inflammation, oxidative stress, and apoptosis.

Proanthocyanidins and β-Glucan Synergistically Regulate Intestinal Inflammation in Dextran Sulfate Sodium-Induced Colitis Mice

Proanthocyanidins (PA) have been proven to have an anti-inflammation effect in multiple models by regulating oxidative stress. β-glucan (BG) could alleviate colitis from the perspectives of intestinal permeability and gut microbiota. In the present study, the synergistic anti-inflammatory function of PA and BG was explored from multiple aspects including immune response, intestinal barrier, gut microbiota, and differential metabolites. The results showed that the supplementation of PA and BG improved the colitis symptoms including atrophy of the colon, body weight loss, and organ index increase. Additionally, inflammatory cytokine levels and oxidative stress status were significantly regulated with the intake of PA and BG. Moreover, PA and BG intervention improved intestinal permeability and promoted the expression of barrier proteins. The microbiome and metabolic profile of cecal contents showed that PA and BG supplementation increased the abundance of anti-inflammatory bacteria and decreased the abundance of pro-inflammatory bacteria. Furthermore, some beneficial metabolites involved in amino acid metabolism, carbohydrate metabolism, and biosynthesis of other secondary metabolite pathways were increased. Overall, these findings have demonstrated the regulation of the inflammatory response and remodel of metabolite profiles by PA and BG complexes, indicating that it may serve as a new strategy for inflammatory bowel disease treatment in the future.

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.

Dimethyl fumarate modulates the regulatory T cell response in the mesenteric lymph nodes of mice with experimental autoimmune encephalomyelitis

Dimethyl fumarate (DMF, Tecfidera) is an oral drug utilized to treat relapsing-remitting multiple sclerosis (MS). DMF treatment reduces disease activity in MS. Gastrointestinal discomfort is a common adverse effect of the treatment with DMF. This study aimed to investigate the effect of DMF administration in the gut draining lymph nodes cells of C57BL6/J female mice with experimental autoimmune encephalomyelitis (EAE), an animal model of MS. We have demonstrated that the treatment with DMF (7.5 mg/kg) significantly reduces the severity of EAE. This reduction of the severity is accompanied by the increase of both proinflammatory and anti-inflammatory mechanisms at the beginning of the treatment. As the treatment progressed, we observed an increasing number of regulatory Foxp3 negative CD4 T cells (Tr1), and anti-inflammatory cytokines such as IL-27, as well as the reduction of PGE2 level in the mesenteric lymph nodes of mice with EAE. We provide evidence that DMF induces a gradual anti-inflammatory response in the gut draining lymph nodes, which might contribute to the reduction of both intestinal discomfort and the inflammatory response of EAE. These findings indicate that the gut is the first microenvironment of action of DMF, which may contribute to its effects of reducing disease severity in MS patients.

Nrf2 regulates the activation-driven expansion of CD4 + T-cells by differentially modulating glucose and glutamine metabolism

Upon antigenic stimulation, CD4 + T-cells undergo clonal expansion, elevating their bioenergetic demands and utilization of nutrients like glucose and glutamine. The nuclear factor erythroid 2-related factor 2 (Nrf2) is a well-known regulator of oxidative stress, but its involvement in modulating the metabolism of CD4 + T-cells remains unexplored. Here, we elucidate the role of Nrf2 beyond the traditional antioxidation, in modulating activation-driven expansion of CD4 + T-cells by influencing their nutrient metabolism. T-cell-specific activation of Nrf2 enhances early activation and IL-2 secretion, upregulates TCR-signaling, and increases activation-driven proliferation of CD4 + T-cells. Mechanistically, high Nrf2 inhibits glucose metabolism through glycolysis but promotes glutamine metabolism via glutaminolysis to support increased T-cell proliferation. Further, Nrf2 expression is temporally regulated in activated CD4 + T-cells with elevated expression during the early activation, but decreased expression thereafter. Overall, our findings uncover a novel role of Nrf2 as a metabolic modulator of CD4 + T-cells, thus providing a framework for improving Nrf2-targeting therapies and T-cell immunotherapies.

RM, Acra SA, Townsend SD, Yan F. A human milk oligosaccharide prevents intestinal inflammation in adulthood via modulating gut microbial metabolism

Observational evidence suggests that human milk oligosaccharides (HMOs) promote the growth of commensal bacteria in early life and adulthood. However, the mechanisms by which HMOs benefit health through modulation of gut microbial homeostasis remain largely unknown. 2'-fucosyllactose (2'-FL) is the most abundant oligosaccharide in human milk and contributes to the essential health benefits associated with human milk consumption. Here, we investigated how 2'-FL prevents colitis in adulthood through its effects on the gut microbial community. We found that the gut microbiota from adult mice that consumed 2'-FL exhibited an increase in abundance of several health-associated genera, including Bifidobacterium and Lactobacillus. The 2'-FL-modulated gut microbial community exerted preventive effects on colitis in adult mice. By using Bifidobacterium infantis as a 2'-FL-consuming bacterial model, exploratory metabolomics revealed novel 2'-FL-enriched secretory metabolites by Bifidobacterium infantis, including pantothenol. Importantly, pantothenate significantly protected the intestinal barrier against oxidative stress and mitigated colitis in adult mice. Furthermore, microbial metabolic pathway analysis identified 26 dysregulated metabolic pathways in fecal microbiota from patients with ulcerative colitis, which were significantly regulated by 2'-FL treatment in adult mice, indicating that 2'-FL has the potential to rectify dysregulated microbial metabolism in colitis. These findings support the contribution of the 2'-FL-shaped gut microbial community and bacterial metabolite production to the protection of intestinal integrity and prevention of intestinal inflammation in adulthood.IMPORTANCEAt present, neither basic research nor clinical studies have revealed the exact biological functions or mechanisms of action of individual oligosaccharides during development or in adulthood. Thus, it remains largely unknown whether human milk oligosaccharides could serve as effective therapeutics for gastrointestinal-related diseases. Results from the present study uncover 2'-FL-driven alterations in bacterial metabolism and identify novel B. infantis-secreted metabolites following the consumption of 2'-FL, including pantothenol. This work further demonstrates a previously unrecognized role of pantothenate in significantly protecting the intestinal barrier against oxidative stress and mitigating colitis in adult mice. Remarkably, 2'-FL-enhanced bacterial metabolic pathways are found to be dysregulated in the fecal microbiota of ulcerative colitis patients. These novel metabolic pathways underlying the bioactivities of 2'-FL may lay a foundation for applying individual oligosaccharides for prophylactic intervention for diseases associated with impaired intestinal homeostasis.

The NRF2/Keap1 pathway as a therapeutic target in inflammatory bowel disease

Oxidative stress (OS) is an important pathophysiological mechanism in inflammatory bowel disease (IBD). However, clinical trials investigating compounds directly targeting OS in IBD yielded mixed results. The NRF2 (nuclear factor erythroid 2-related factor 2)/Keap1 (Kelch-like ECH-associated protein 1) pathway orchestrates cellular responses to OS, and dysregulation of this pathway has been implicated in IBD. Activation of the NRF2/Keap1 pathway may enhance antioxidant responses. Although this approach could help to attenuate OS and potentially improve clinical outcomes, an overview of human evidence for modulating the NRF2/Keap1 axis and more recent developments in IBD is lacking. This review explores the NRF2/Keap1 pathway as potential therapeutic target in IBD and presents compounds activating this pathway for future clinical applications.

Novel potential pharmacological applications of dimethyl fumarate-an overview and update

Dimethyl fumarate (DMF) is an FDA-approved drug for the treatment of psoriasis and multiple sclerosis. DMF is known to stabilize the transcription factor Nrf2, which in turn induces the expression of antioxidant response element genes. It has also been shown that DMF influences autophagy and participates in the transcriptional control of inflammatory factors by inhibiting NF-κB and its downstream targets. DMF is receiving increasing attention for its potential to be repurposed for several diseases. This versatile molecule is indeed able to exert beneficial effects on different medical conditions through a pleiotropic mechanism, in virtue of its antioxidant, immunomodulatory, neuroprotective, anti-inflammatory, and anti-proliferative effects. A growing number of preclinical and clinical studies show that DMF may have important therapeutic implications for chronic diseases, such as cardiovascular and respiratory pathologies, cancer, eye disorders, neurodegenerative conditions, and systemic or organ specific inflammatory and immune-mediated diseases. This comprehensive review summarizes and highlights the plethora of DMF's beneficial effects and underlines its repurposing opportunities in a variety of clinical conditions.

miR-200a attenuated oxidative stress, inflammation, and apoptosis in dextran sulfate sodium-induced colitis through activation of Nrf2

Introduction

Oxidative stress and inflammatory responses are critical factors in ulcerative colitis disease pathogenesis. Nuclear factor erythroid 2-related factor 2 (Nrf2) modulates oxidative stress and suppresses inflammatory responses, and the protective benefits of Nrf2 activation have been associated with the therapy of ulcerative colitis. MicroRNA-200a (miR-200a) could target Kelch-like ECH-associated protein 1 (Keap1) and activate the Nrf2-regulated antioxidant pathway. Nevertheless, whether miR-200a modulates the Keap1/Nrf2 pathway in dextran sulfate sodium (DSS)-induced colonic damage is unknown. Here, our research intends to examine the impact of miR-200a in the model of DSS-induced colitis.

Methods

Prior to DSS intervention, we overexpressed miR-200a in mice for four weeks using an adeno-associated viral (AAV) vector to address this problem. ELISA detected the concentration of inflammation-related cytokines. The genes involved in inflammatory reactions and oxidative stress were identified using quantitative reverse transcription-polymerase chain reaction (qRT-PCR), western blot, and immunofluorescence. Moreover, we applied siRNAs to weakened Nrf2 expression to confirm the hypothesis that miR-200a provided protection via Nrf2.

Results

The present study discovered miR-200a down-regulation, excessive inflammatory activation, enterocyte apoptosis, colonic dysfunction, and Keap1/Nrf2 antioxidant pathway inactivation in mouse colitis and NCM460 cells under DSS induction. However, our data demonstrated that miR-200a overexpression represses Keap1 and activates the Nrf2 antioxidant pathway, thereby alleviating these adverse alterations in animal and cellular models. Significantly, following Nrf2 deficiency, we failed to observe the protective benefits of miR-200a against colonic damage.

Discussion

Taken together, through activating the Keap1/Nrf2 signaling pathway, miR-200a protected against DSS-induced colonic damage. These studies offer an innovative therapeutic approach for ulcerative colitis.

Dimethyl Fumarate and Intestine: From Main Suspect to Potential Ally against Gut Disorders

Dimethyl fumarate (DMF) is a well-characterized molecule that exhibits immuno-modulatory, anti-inflammatory, and antioxidant properties and that is currently approved for the treatment of psoriasis and multiple sclerosis. Due to its Nrf2-dependent and independent mechanisms of action, DMF has a therapeutic potential much broader than expected. In this comprehensive review, we discuss the state-of-the-art and future perspectives regarding the potential repurposing of DMF in the context of chronic inflammatory diseases of the intestine, such as inflammatory bowel disorders (i.e., Crohn's disease and ulcerative colitis) and celiac disease. DMF's mechanisms of action, as well as an exhaustive analysis of the in vitro/in vivo evidence of its beneficial effects on the intestine and the gut microbiota, together with observational studies on multiple sclerosis patients, are here reported. Based on the collected evidence, we highlight the new potential applications of this molecule in the context of inflammatory and immune-mediated intestinal diseases.

Dimethyl fumarate protects against intestine damage in necrotizing enterocolitis by inhibiting the Toll-like receptor (TLR) inflammatory signaling pathway

OBJECTIVE

Necrotizing enterocolitis (NEC) is a severe disease in newborns, this study aimed to investigate the protective effect of dimethyl fumarate (DMF) on NEC and its possible mechanism.

METHODS

In vivo, the mice were divided into the control, NEC, and NEC+DMF group. The NEC model was established by artificial feeding, hypoxic for 4 days, and lipopolysaccharide (LPS) stimulation on day 2 and day 3. DMF (25 mg/kg/d) was administered to NEC mice on day 1 and day 3. On the 11th day, the blood and intestinal tissues of mice were taken for enzyme-linked immunosorbent assay (ELISA), pathological examination, quantitative real-time PCR (RT-qPCR), Western blot, and immunohistochemical (IHC) detection. In vitro, human colorectal cells (FHC) were induced by LPS (100 ng/mL) and was divided into the control, LPS, and LPS+DMF group. The effect of DMF (20 μM) on cell viability and TLR4 signal transduction was detected by MTT and RT-qPCR, respectively.

RESULTS

Compared to the NEC mice, DMF attenuated NEC-induced weight loss and abdominal distension diarrhea in mice, and alleviated NEC-induced intestinal pathological injuries. In addition, DMF reduced the expression of IL-6, IL-1β, TNF-α, NF-κB, and TLR4 in NEC mice intestinal tissues. Furthermore, DMF inhibited NEC-induced intestinal cell apoptosis as well as the protein expression of BCL2-Associated X (BAX), caspase-3, caspase-9, and increased Bcl-2 (B-cell lymphoma-2) expression. In vitro, DMF improved cell viability, and restrained NF-κB and TLR4 expression in LPS-induced NEC cells.

CONCLUSION

DMF has a protective effect against intestine damage of NEC, which is related to the inhibition of the TLR signaling pathway, alleviating the inflammatory response.

Personalized redox medicine in inflammatory bowel diseases: an emerging role for HIF-1α and NRF2 as therapeutic targets

Inflammatory bowel diseases (IBD), encompassing Crohn's disease (CD) and ulcerative colitis (UC), are intimately associated with inflammation and overproduction of reactive oxygen species (ROS). Temporal and inter-individual variabilities in disease activity and response to therapy pose significant challenges to diagnosis and patient care. Discovery and validation of truly integrative biomarkers would benefit from embracing redox metabolomics approaches with prioritization of central regulatory hubs. We here make a case for applying a personalized redox medicine approach that aims to selectively inhibit pathological overproduction and/or altered expression of specific enzymatic sources of ROS without compromising physiological function. To this end, improved 'clinical-omics integration' may help to better understand which particular redox signaling pathways are disrupted in what patient. Pharmacological interventions capable of activating endogenous antioxidant defense systems may represent viable therapeutic options to restore local/systemic redox status, with HIF-1α and NRF2 holding particular promise in this context. Achieving the implementation of clinically meaningful mechanism-based biomarkers requires development of easy-to-use, robust and cost-effective tools for secure diagnosis and monitoring of treatment efficacy. Ultimately, matching redox-directed pharmacological interventions to individual patient phenotypes using predictive biomarkers may offer new opportunities to break the therapeutic ceiling in IBD.

Protective effects of Rubus tereticaulis leaves ethanol extract on rats with ulcerative colitis and bio-guided isolation of its active compounds: A combined in silico, in vitro and in vivo study

The aim of this study was to evaluate the therapeutic effect of active ethanol extract obtained from the leaves of Rubus tereticaulis (RTME) against colitis, and to purify major compounds from this extract by bioassay-directed isolation. Rats with colitis induced via intra-rectal acetic acid administration (5%, v/v) received RTME or sulfasalazine for three consecutive days. On day four, all rats were decapitated, and the colonic tissue samples were collected for macroscopic score, colon weight, reduced glutathione (GSH), myeloperoxidase (MPO), and malondialdehyde (MDA) analyses. The active compounds and chemical composition of RTME were determined by bio-guided isolation and LC-MS/MS, respectively. Compared to the colitis group, the rats treated with RTME displayed significantly lowered macroscopic scores and colon wet weights (p < 0.001). These effects were confirmed biochemically by a decrease in colonic MPO activity (p < 0.001), MDA levels (p < 0.001), and an increase in GSH levels (p < 0.001). Kaempferol-3-O-β-d-glucuronide (RT1) and quercetin-3-O-β-d-glucuronide (RT2) were found to be the major compounds of RTME, as evidenced by in vitro anti-inflammatory and antioxidant activity-guided isolation. Their anti-inflammatory/antioxidant activities were also predicted by docking simulations. Additionally, quinic acid, 5-caffeoylquinic acid, quercetin pentoside, quercetin glucoside, quercetin-3-O-β-d-glucuronide, kaempferol-3-O-β-d-glucuronide, and kaempferol rutinoside were identified in RTME via using LC-MS/MS. RT2, along with other compounds, may be responsible for the observed protective action of RTME against colitis. This study represents the first report on the beneficial effects of RTME in an experimental model of colitis and highlights the potential future use of RTME as a natural alternative to alleviate colitis.

Using Drosophila melanogaster as a suitable platform for drug discovery from natural products in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic and life-treating inflammatory disease that can occur in multiple parts of the human intestine and has become a worldwide problem with a continually increasing incidence. Because of its mild early symptoms, most of them will not attract people's attention and may cause more serious consequences. There is an urgent need for new therapeutics to prevent disease progression. Natural products have a variety of active ingredients, diverse biological activities, and low toxicity or side effects, which are the new options for preventing and treating the intestinal inflammatory diseases. Because of multiple genetic models, less ethical concerns, conserved signaling pathways with mammals, and low maintenance costs, the fruit fly Drosophila melanogaster has become a suitable model for studying mechanism and treatment strategy of IBD. Here, we review the advantages of fly model as screening platform in drug discovery, describe the conserved molecular pathways as therapetic targets for IBD between mammals and flies, dissect the feasibility of Drosophila model in IBD research, and summarize the natural products for IBD treatment using flies. This review comprehensively elaborates that the benefit of flies as a perfact model to evaluate the therapeutic potential of phytochemicals against IBD.

The role of phosphatidylcholine 34:1 in the occurrence, development and treatment of ulcerative colitis

Lipid homeostasis is considered to be related to intestinal metabolic balance, while its role in the pathogenesis and treatment of ulcerative colitis (UC) remains largely unexplored. The present study aimed to identify the target lipids related to the occurrence, development and treatment of UC by comparing the lipidomics of UC patients, mice and colonic organoids with the corresponding healthy controls. Here, multi-dimensional lipidomics based on LC-QTOF/MS, LC-MS/MS and iMScope systems were constructed and used to decipher the alteration of lipidomic profiles. The results indicated that UC patients and mice were often accompanied by dysregulation of lipid homeostasis, in which triglycerides and phosphatidylcholines were significantly reduced. Notably, phosphatidylcholine 34:1 (PC34:1) was characterized by high abundance and closely correlation with UC disease. Our results also revealed that down-regulation of PC synthase PCYT1α and Pemt caused by UC modeling was the main factor leading to the reduction of PC34:1, and exogenous PC34:1 could greatly enhance the fumarate level via inhibiting the transformation of glutamate to N-acetylglutamate, thus exerting an anti-UC effect. Collectively, our study not only supplies common technologies and strategies for exploring lipid metabolism in mammals, but also provides opportunities for the discovery of therapeutic agents and biomarkers of UC.

Conservation Environments' Effect on the Compressive Strength Behaviour of Wood-Concrete Composites

This paper addresses the issues in making wood-concrete composites more resilient to environmental conditions and to improve their compressive strength. Tests were carried out on cubic specimens of 10 × 10 × 10 cm³ composed of ordinary concrete with a 2% redwood- and hardwood-chip dosage. Superficial treatments of cement and lime were applied to the wood chips. All specimens were kept for 28 days in the open air and for 12 months in: the open air, drinking water, seawater, and an oven. Consequently, the compressive strength of ordinary concrete is approximately 37.1 MPa. After 365 days of exposure to the open air, drinking water, seawater, and the oven, a resistance loss of 35.84, 36.06, 42.85, and 52.30% were observed, respectively. In all environments investigated, the untreated wood composite concrete's resistance decreased significantly, while the cement/lime treatment of the wood enhanced them. However, only 15.5 MPa and 14.6 MPa were attained after the first 28 days in the cases of the redwood and the hardwood treated with lime. These findings indicate that the resistance of wood-concrete composites depends on the type of wood used. Treating wood chips with cement is a potential method for making these materials resistant in conservation situations determined by the cement's chemical composition. The current study has implications for researchers and practitioners for further understanding the impact of these eco-friendly concretes in the construction industry.

Dimethyl Fumarate Ameliorates Doxorubicin-Induced Cardiotoxicity By Activating the Nrf2 Pathway

Doxorubicin (DOX) is limited in clinical application because of its cardiotoxicity. Oxidative stress and apoptosis are crucial in DOX-induced cardiac injury. Dimethyl fumarate (DMF) is an FDA-approved oral drug with powerful effects to reduce oxidative stress and apoptosis through the Nrf2 pathway. This study was aimed to determine whether DMF can protect against DOX-induced cardiac injury. We used both neonatal rat cardiomyocytes (NRCMs) in vitro and DOX-induced cardiac toxicity in vivo to explore the effects of DMF. The results showed that DMF significantly improved cell viability and morphology in NRCMs. In addition, DMF alleviated DOX-induced cardiac injury in rats, as evidenced by decreased CK-MB, LDH levels, improved survival rates, cardiac function, and pathological changes. Moreover, DMF significantly inhibited cardiac oxidative stress by reducing MDA levels and increasing GSH, SOD, and GSH-px levels. And DMF also inhibited DOX-induced cardiac apoptosis by modulating Bax, Bcl-2 and cleaved caspase-3 expression. Moreover, DMF exerted its protective effects against DOX by promoting Nrf2 nuclear translocation, which activated its downstream antioxidant gene Hmox1. Silencing of Nrf2 attenuated the protective effects of DMF in NRCMs as manifested by increased intracellular oxidative stress, elevated apoptosis levels, and decreased cell viability. In addition, DMF showed no protective effects on the viability of DOX-treated tumor cells, which suggested that DMF does not interfere with the antitumor effect of DOX in vitro. In conclusion, our data confirmed that DMF alleviated DOX-induced cardiotoxicity by regulating oxidative stress and apoptosis through the Nrf2 pathway. DMF may serve as a new candidate to alleviate DOX-related cardiotoxicity in the future.

Luteolin Confers Cerebroprotection after Subarachnoid Hemorrhage by Suppression of NLPR3 Inflammasome Activation through Nrf2-Dependent Pathway

Luteolin (LUT) possesses multiple biologic functions and has beneficial effects for cardiovascular and cerebral vascular diseases. Here, we investigated the protective effects of LUT against subarachnoid hemorrhage (SAH) and the involvement of underlying molecular mechanisms. In a rat model of SAH, LUT significantly inhibited SAH-induced neuroinflammation as evidenced by reduced microglia activation, decreased neutrophil infiltration, and suppressed proinflammatory cytokine release. In addition, LUT markedly ameliorated SAH-induced oxidative damage and restored the endogenous antioxidant systems. Concomitant with the suppressed oxidative stress and neuroinflammation, LUT significantly improved neurologic function and reduced neuronal cell death after SAH. Mechanistically, LUT treatment significantly enhanced the expression of nuclear factor-erythroid 2-related factor 2 (Nrf2), while it downregulated nod-like receptor pyrin domain-containing 3 (NLRP3) inflammasome activation. Inhibition of Nrf2 by ML385 dramatically abrogated LUT-induced Nrf2 activation and NLRP3 suppression and reversed the beneficial effects of LUT against SAH. In neurons and microglia coculture system, LUT also mitigated oxidative stress, inflammatory response, and neuronal degeneration. These beneficial effects were associated with activation of the Nrf2 and inhibitory effects on NLRP3 inflammasome and were reversed by ML385 treatment. Taken together, this present study reveals that LUT confers protection against SAH by inhibiting NLRP3 inflammasome signaling pathway, which may be modulated by Nrf2 activation.

Dimethyl fumarate prevents acute lung injury related cognitive impairment potentially via reducing inflammation

OBJECTIVE

Dimethyl fumarate (DMF) has been reported to exert a protective role against diverse lung diseases and cognitive impairment-related diseases. Thus this study aimed to investigate its role on acute lung injury (ALI) and related cognitive impairment in animal model.

METHODS

C57BL/6 mice were divided into four groups: control group, DMF group, ALI group, and ALI + DMF group. For ALI group, the ALI mice model was created by airway injection of LPS (50 μL, 1 μg/μL); for ALI + DMF group, DMF (dissolved in 0.08% methylcellulose) was treated twice a day for 2 days, and on the third day, mice were injected with LPS for ALI modeling. Mice pre-administered with methylcellulose or DMF without LPS injection (PBS instead) were used as the control group and DMF group, respectively. Morris water maze test was performed before any treatment (0 h) and 6 h after LPS-induction (54 h) to evaluate the cognitive impairment of mice. Next, the brain edema and blood brain barrier (BBB) permeability of ALI mice were assessed by brain water content, Evans blue extravasation and FITC-Dextran uptake assays. In addition, the effect of DMF on the numbers of total cells and neutrophils, protein content in BALF were quantified; the inflammatory factors in BALF, serum, and brain tissues were examined by ELISA, qRT-PCR, and Western blot assays. The effect of DMF on the cognitive impairment-related factor HIF-1α level in lung and brain tissues was also examined by Western blot.

RESULTS

DMF reduced the numbers of total cells, neutrophils and protein content in BALF of ALI mice, inhibited the levels of IL-6, TNF-α and IL-1β in BALF, serum and brain tissues of ALI mice. The protein expressions of p-NF-κB/NF-κB and p-IKBα/IKBα was also suppressed by DMF in ALI mice. Morris water maze test showed that DMF alleviated the cognitive impairment in ALI mice by reducing the escape latency and path length. Moreover, DMF lessened the BBB permeability by decreasing cerebral water content, Evans blue extravasation and FITC-Dextran uptake in ALI mice. The HIF-1α levels in lung and brain tissues of ALI mice were also lessened by DMF.

CONCLUSION

In conclusion, DME had the ability to alleviate the lung injury and cerebral cognitive impairment in ALI model mice. This protective effect partly associated with the suppression of inflammation by DMF.

Therapeutic implications of inflammasome in inflammatory bowel disease

Inflammatory bowel disease (IBD) remains a persistent health problem with a global burden surging over 6.8 million cases currently. Clinical pathology of IBD is complicated; however, hyperactive inflammatory and immune responses in the gut is shown to be one of the persistent causes of the disease. Human gut inflammasome, the activator of innate immune system is believed to be a primary underlying cause for the pathology and is largely associated with the progression of IBD. To manage IBD, there is a need to fully understand the role of inflammasome activation in IBD. Since inflammasome potentially play a significant role in IBD, systemic modulation of inflammasome may provide an effective therapeutic and clinical approach to control IBD symptoms. In this review, we have focused on this association between IBD and gut inflammasome, and recent advances in the research and therapeutic strategies for IBD. We have discussed inflammasomes and their components, outcomes from the experimental animals and human studies, inflammasome inhibitors, and developments in the inflammasome-targeted therapies for IBD.

Inflammasome Regulation: Therapeutic Potential for Inflammatory Bowel Disease

Inflammasomes are multiprotein complexes formed to regulate the maturation of pro-inflammatory caspases, in response to intracellular or extracellular stimulants. Accumulating studies showed that the inflammasomes are implicated in the pathogenesis of inflammatory bowel disease (IBD), although their activation is not a decisive factor for the development of IBD. Inflammasomes and related cytokines play an important role in the maintenance of gut immune homeostasis, while its overactivation might induce excess immune responses and consequently cause tissue damage in the gut. Emerging studies provide evidence that some genetic abnormalities might induce enhanced NLRP3 inflammasome activation and cause colitis. In these cases, the colonic inflammation can be ameliorated by blocking NLRP3 activation or its downstream cytokine IL-1β. A number of natural products were shown to play a role in preventing colon inflammation in various experimental colitis models. On the other hand, lack of inflammasome function also causes intestinal abnormalities. Thus, an appropriate regulation of inflammasomes might be a promising therapeutic strategy for IBD intervention. This review aims at summarizing the main findings in these studies and provide an outline for further studies that might contribute to our understanding of the role of inflammasomes in the pathogenesis and therapeutic treatment of IBD.

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.

Prevention of Autoimmune Diabetes in NOD Mice by Dimethyl Fumarate

Oxidative stress plays critical roles in the pathogenesis of diabetes. This study tested the hypothesis that by protecting β-cells against oxidative stress and inflammation, an Nrf2 activator, dimethyl fumarate (DMF), may prevent or delay the onset of type 1 diabetes in non-obese diabetic (NOD) mice. Firstly, islet isolation was conducted to confirm the antioxidative effects of DMF oral administration on islet cells. Secondly, in a spontaneous diabetes model, DMF (25 mg/kg) was fed to mice once daily starting at the age of 8 weeks up to the age of 22 weeks. In a cyclophosphamide-induced accelerated diabetes model, DMF (25 mg/kg) was fed to mice twice daily for 2 weeks. In the islet isolation study, DMF administration improved the isolation yield, attenuated oxidative stress and enhanced GCLC and NQO1 expression in the islets. In the spontaneous model, DMF significantly reduced the onset of diabetes compared to the control group (25% vs. 54.2%). In the accelerated model, DMF reduced the onset of diabetes from 58.3% to 16.7%. The insulitis score in the islets of the DMF treatment group (1.6 ± 0.32) was significantly lower than in the control group (3.47 ± 0.21). The serum IL-1α, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-9, IL-12p70, IFN-γ, TNF-α, MCP-1 and CXCL16 levels in the DMF-treated group were lower than in the control group. In conclusion, DMF may protect islet cells and reduce the incidence of autoimmune diabetes in NOD mice by attenuating insulitis and proinflammatory cytokine production.

Identification and optimization of piperlongumine analogues as potential antioxidant and anti-inflammatory agents via activation of Nrf2

Oxidative stress and inflammation are significant risk factors for neurodegenerative disease. The Keap1-Nrf2-ARE pathway is one of the most promising defensive systems against oxidative stress. Here, dozens of piperlongumine analogues were designed, synthesized, and tested on PC12 cells to examine neuroprotective effects against H2O2 and 6-OHDA induced damage. Among them, 6d was found to be able to alleviate the accumulation of ROS, inhibit the production of NO and downregulate the level of IL-6, which indicated its potential antioxidant and anti-inflammatory activity. Further studies proved that 6d could activate Nrf2 signaling pathway, induce the translocation of Nrf2 from cell cytosol to nucleus and upregulate the related phase II antioxidant enzymes including NQO1, HO-1, GCLC, GCLM and TrxR1. These results confirmed that 6d exerted antioxidant and anti-inflammatory activities by activating Nrf2 signaling pathway. Moreover, the parallel artificial membrane permeability assay indicated that 6d can cross the blood-brain barrier. In general, 6d is promising for further development as a therapeutic drug against oxidative stress and inflammation related neurodegenerative disorders.

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.

Ischemic postconditioning attenuates acute kidney injury following intestinal ischemia-reperfusion through Nrf2-regulated autophagy, anti-oxidation, and anti-inflammation in mice

Intestinal ischemia-reperfusion (IIR) often occurs during and following major cardiovascular or gut surgery and causes significant organ including kidney injuries. This study was to investigate the protective effect of intestinal ischemic postconditioning (IPo) on IIR-induced acute kidney injury (AKI) and the underling cellular signaling mechanisms with focus on the Nrf2/HO-1. Adult C57BL/6J mice were subjected to IIR with or without IPo. IIR was established by clamping the superior mesenteric artery (SMA) for 45 minutes followed by 120 minutes reperfusion. Outcome measures were: (i) Intestinal and renal histopathology; (ii) Renal function; (iii) Cellular signaling changes; (iv) Oxidative stress and inflammatory responses. IPo significantly attenuated IIR-induced kidney injury. Furthermore, IPo significantly increased both nuclear Nrf2 and HO-1 expression in the kidney, upregulated autophagic flux, inhibited IIR-induced inflammation and reduced oxidative stress. The protective effect of IPo was abolished by the administration of Nrf2 inhibitor (Brusatol) or Nrf2 siRNA. Conversely, a Nrf2 activator t-BHQ has a similar protective effect to that of IPo. Our data indicate that IPo protects the kidney injury induced by IIR, which was likely mediated through the Nrf2/HO-1 cellular signaling activation.