Dimethyl fumarate inhibits NLRP3/AIM2 inflammasomes to prevent spleen radiation injury ZHANG / 中国药理学通报

Aim To investigate the protective effect of dimethyl fumarate on spleen injury induced by gamma radiation in mice and the related mechanism. Methods C57BL/6 mice were randomly divided into the blank control group, radiation model group and DMF administration group, which were administered once at 12 h before irradiation and once at 0. 5 h, 12 h, 24 h and 48 h after irradiation. The 30-day survival rate, body weight and pathological injury of spleen were measured after a one-time total body irradiation of Co 7 rays (8 Gy). TUNEL staining was used to detect apoptosis of spleen cells. Enzyme-linked immunoassay ( ELISA) was applied to detect the contents of TNF-a, IL-1 p, IL-6, IL-18, NLRP3 and AIM2 in spleen. Western blot test and immunofluorescence staining test was employed to verify the changes of NLRP3 and AIM2 contents in spleen tissue after irradiation. Results DMF could obviously improve the survival rate of irradiated mice, improve the weight loss of irradiated mice, re-duce the pathological injury of spleen, and inhibit the apoptosis of spleen cells after irradiation. ELISA results showed that DMF could significantly inhibit the increase of spleen inflammatory cytokines TNF-a, IL-lp, IL-6, IL-18 and inflammasome components NL-RP3 and AIM2 induced by irradiation. Western blot and tissue immunofluorescence staining also confirmed that DMF could inhibit the increase of NLRP3 and AIM2 inflammasome protein levels caused by irradiation. Meanwhile, NLRP3 agonist and AIM2 agonist could antagonize the radiation protection effect of DMF on spleen cells. Conclusion DMF can ameliorate spleen injury of Co 7-ray injured mice, and its mechanism is closely related to NLRP3/AIM2 inflamma-somes, which can be used as a potential protective drug for radiation injury.

Therapeutic Effects of Dimethyl Fumarate on the Rat Model of Brain Ischemia

Abstract Blood-brain barrier (BBB) disruption, inflammation, and cell death are major pathogenic mechanisms in ischemic stroke. Dimethyl fumarate (DMF) has anti-inflammatory and immune-modulatory effects. So, this study aimed to elucidate the effects of DMF on brain ischemia in the middle cerebral artery occlusion (MCAO) model. 69 Sprague-Dawley male rats were allocated into a sham group that was just subjected to surgery stress; vehicle and DMF groups, after MCAO, received vehicle or 30 mg/kg DMF for three days. Neurological scores were evaluated every day. BBB disruption was evaluated by the extravasation of Evans blue. In addition to the measurement of brain water content, the total and infarct volume, numerical density, and the total number of neurons, non-neurons, and dead neurons in the right cortex were estimated by stereological methods. RT-PCR was done to analyze the expression levels of NF-κB and Nrf2. Although brain ischemia treatment with DMF did not have a significant effect on the infarction size, it improved neurobehavioral function, BBB disruption, cerebral edema, increased number of neurons, and expression of Nrf2. It also decreased the number of dead neurons and the expression of NF-κB. DMF beneficial effects on stroke may be mediated through both increase of the Nrf2 and decrease of NF-κB expression

Effect of Dimethyl Fumarate (DMF) on T-cell Acute Lymphoblastic Leukemia / 中国实验血液学杂志

OBJECTIVE@#To explore the effect and possible mechanism of dimethyl fumarate (DMF) on T-cell acute lymphoblastic leukemia (T-ALL), and provide experimental and theoretical basis for the clinical treatment of T-ALL.@*METHODS@#Jurkat cells were treated with different concentrations of DMF for 24 hours, and then the proportion and absolute count of Ki67-positive Jurkat cells were analyzed by flow cytometry. Meanwhile, the protein levels of nuclear factor-erythroid 2-related factor 2 (Nrf2) and E3 ubiquitin ligase HACE1 in Jurkat cells treated with DMF for 24 hours were evaluated by Western blot. Nrf2 proteins were co-immunoprecipitated in Jurkat cells, and then HACE1 protein was assessed by Western blot. Plasmids of Flag-Nrf2 and different gradients of Flag-HACE1 were transfected into HEK293T cells, and the levels of Flag-Nrf2 were detected by Western blot after 48 hours.@*RESULTS@#DMF could significantly inhibit the proportion and absolute count of Ki67-positive Jurkat cells, and DMF inhibited the proliferation of Jurkat cells in a dose-dependent manner (r=0.9595, r=0.9054). DMF could significantly up-regulate the protein levels of Nrf2 and E3 ubiquitin ligase HACE1 in Jurkat cells (P<0.01, P<0.01). HACE1 physically interacted with Nrf2 in Jurkat cells. Overexpression of Flag-HACE1 significantly increased the protein level of Flag-Nrf2 in a dose-dependent manner (r=0.9771).@*CONCLUSION@#DMF inhibits the proliferation of T-cell acute lymphoblastic leukemia cell. The mechanism may be that, DMF significantly up-regulates the protein levels of Nrf2 and E3 ubiquitin ligase HACE1, and HACE1 interacts with Nrf2 and positively regulates Nrf2 protein level.

Neuroprotection and immunomodulation by dimethyl fumarate and a heterologous fibrin biopolymer after ventral root avulsion and reimplantation

Ventral root avulsion (VRA) is an experimental approach in which there is an abrupt separation of the motor roots from the surface of the spinal cord. As a result, most of the axotomized motoneurons degenerate by the second week after injury, and the significant loss of synapses and increased glial reaction triggers a chronic inflammatory state. Pharmacological treatment associated with root reimplantation is thought to overcome the degenerative effects of VRA. Therefore, treatment with dimethyl fumarate (DMF), a drug with neuroprotective and immunomodulatory effects, in combination with a heterologous fibrin sealant/biopolymer (FS), a biological glue, may improve the regenerative response. Methods: Adult female Lewis rats were subjected to VRA of L4-L6 roots followed by reimplantation and daily treatment with DMF for four weeks. Survival times were evaluated 1, 4 or 12 weeks after surgery. Neuronal survival assessed by Nissl staining, glial reactivity (anti-GFAP for astrocytes and anti-Iba-1 for microglia) and synapse preservation (anti-VGLUT1 for glutamatergic inputs and anti-GAD65 for GABAergic inputs) evaluated by immunofluorescence, gene expression (pro- and anti-inflammatory molecules) and motor function recovery were measured. Results: Treatment with DMF at a dose of 15 mg/kg was found to be neuroprotective and immunomodulatory because it preserved motoneurons and synapses and decreased astrogliosis and microglial reactions, as well as downregulated the expression of pro-inflammatory gene transcripts. Conclusion: The pharmacological benefit was further enhanced when associated with root reimplantation with FS, in which animals recovered at least 50% of motor function, showing the efficacy of employing multiple regenerative approaches following spinal cord root injury.(AU)

Effect of dimethyl fumarate on rats with chronic pancreatitis

OBJECTIVE@#To discuss the effect of dimethyl fumarate (DMF) on rats with l-arginine induced chronic pancreatitis (CP).@*METHODS@#Male Wistar rats were given DMF treatment (25 mg/kg) by oral lavage method; then Wistar rats were given the intraperitoneal injection of l-arginine for 5 times (250 mg/100 kg, twice per time, each interval of 1 h) for building of CP model. Rats were divided into control group, CP group, DMF group and CP + DMF group. Rats in CP + DMF group were given the oral intragastric administration of DMF (25 mg/kg), while rats in control group and CP group were given the equal volume of normal saline. The weight of rats was evaluated and the intraperitoneal glucose tolerance test was performed (IPGTT, 2 g/kg). The islet of rats was isolated and then flow cytometry was employed to evaluate the quality and activity of islets. Meanwhile, the histology of non-endocrine tissues and levels of myeloperoxidase (MPO) and malondialdehyde (MDA) were detected.@*RESULTS@#Compared with control group, the weight of rats in CP group was significantly reduced at week 2, 4 and 6; the blood glucose significantly increased, AUC increased, the histopathological scores of pancreatic atrophy, acinar injury, edema and cellular infiltration increased, levels of MDA and MPO increased, the islet equivalent and islet activity decreased at 0, 30, 60, 120 and 180 min. Compared with CP group, the weight of rats in CP + DMF group significantly increased at week 2, 4 and 6; the blood glucose significantly decreased, AUC decreased, the histopathological scores of pancreatic atrophy, acinar injury, edema and cellular infiltration decreased, levels of MDA and MPO decreased, the islet equivalent and islet activity increased at 0, 30, 60, 120 and 180 min.@*CONCLUSIONS@#DMF treatment can improve CP induced by l-arginine and islet function in rats.

Effect of dimethyl fumarate on rats with chronic pancreatitis

Objective: To discuss the effect of dimethyl fumarate (DMF) on rats with l-arginine induced chronic pancreatitis (CP). Methods: Male Wistar rats were given DMF treatment (25 mg/kg) by oral lavage method; then Wistar rats were given the intraperitoneal injection of l-arginine for 5 times (250 mg/100 kg, twice per time, each interval of 1 h) for building of CP model. Rats were divided into control group, CP group, DMF group and CP + DMF group. Rats in CP + DMF group were given the oral intragastric administration of DMF (25 mg/kg), while rats in control group and CP group were given the equal volume of normal saline. The weight of rats was evaluated and the intraperitoneal glucose tolerance test was performed (IPGTT, 2 g/kg). The islet of rats was isolated and then flow cytometry was employed to evaluate the quality and activity of islets. Meanwhile, the histology of non-endocrine tissues and levels of myeloperoxidase (MPO) and malondialdehyde (MDA) were detected. Results: Compared with control group, the weight of rats in CP group was significantly reduced at week 2, 4 and 6; the blood glucose significantly increased, AUC increased, the histopathological scores of pancreatic atrophy, acinar injury, edema and cellular infiltration increased, levels of MDA and MPO increased, the islet equivalent and islet activity decreased at 0, 30, 60, 120 and 180 min. Compared with CP group, the weight of rats in CP + DMF group significantly increased at week 2, 4 and 6; the blood glucose significantly decreased, AUC decreased, the histopathological scores of pancreatic atrophy, acinar injury, edema and cellular infiltration decreased, levels of MDA and MPO decreased, the islet equivalent and islet activity increased at 0, 30, 60, 120 and 180 min. Conclusions: DMF treatment can improve CP induced by l-arginine and islet function in rats.

Dimethyl fumarate: a novel drug for multiple sclerosis.

Dimethyl fumarate (DMF) is a novel oral immunomodulatory and neuroprotective drug that was approved by FDA for relapsing forms of multiple sclerosis (MS). The initial use of DMF was for the treatment of psoriasis where its long-term use was safe and efficacious, and it also got German approval for the same. It was found that the anti-inflammatory actions of DMF contributed to its efficacy in psoriasis. This anti-inflammatory action of DMF created interest using DMF in other auto-immune or inflammatory diseases, including MS. DMF acts by decreasing production and release of inflammatory molecules. DMF also activates the nuclear factor-erythroid 2 related factor pathway which induces the transcription of various genes, including anti-oxidative ones, reduces oxidative neuronal death and helps maintain myelin integrity. Thus, DMF acts via two pathways: by down-regulating oxidative stress and corresponding cellular injury, as well as by inhibiting pro-inflammatory cytokines. DMF is an orally administered, enteric-coated microtablet preparation. There was a 44-53% reduction in annualized relapse rate with the use of DMF in patients with relapsing form of MS. The most common adverse reactions reported are flushing, abdominal pain, diarrhea, and nausea, which are more prominent during initial treatment and usually decrease over time. No serious adverse events were seen during the phase II and III trials, including no increased risk of opportunistic infections or cancer. DMF seems to approach the ideal combination of safety, efficacy and welltolerability to other approved oral therapies for MS.