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Wednesday, 11 September 2019

DMF and MMF for Neuroprotection and Immunomodulation in MS, TBI, Parkinson’s and potentially much more




DMF is an inexpensive chemical and was used to stop mould growing on sofas shipped from China to Europe, until it was banned as a skin irritant. It is also an expensive drug, sold by Biogen.


DMF was discussed in an earlier post on ketones, because one of the anti-inflammatory effects of the ketone BHB can also be achieved using Dimethyl Fumarate (DMF). In the body DMF is converted to MMF by a chemical reaction with the body’s key antioxidant Glutathione (GSH). Surprisingly, DMF then goes on to improve GSH recycling and actually raise GSH levels.

Ketones and Autism Part 3 - Niacin Receptor HCA2/GPR109A in Autism, Colonic Inflammation, Psoriasis and Multiple Sclerosis


                       
DMF is a very cheap chemical that has been sold as an extremely expensive drug, first in Germany to treat Psoriasis and later Multiple Sclerosis (MS). I did explain in an earlier post how a person unable to afford $50,000 a year for the Tecfidera drug version could achieve the same result for a couple of hundred dollars.

The drug form of DMF is cheaper in Europe, but still very pricey.

The good news is that some of Biogen’s patents are expiring and so new cheaper drug versions will appear, including one for MMF itself that may greatly reduce the GI side effects experienced by some people.

I do think that DMF, at much lower doses than used today, has potential to treat a wide range of inflammatory conditions. This will almost inevitably include some types of autism.  In one of Biogen’s patents they refer to a long list of potential applications: -

“The pharmaceutical composition according to any one of the above aspects is for use in the treatment of psoriasis (including moderate to severe plaque psoriasis), psoriatic arthritis, neurodermatitis, inflammatory bowel disease, such as Crohn's disease and ulcerative colitis, polyarthritis, multiple sclerosis including relapsing—remitting multiple sclerosis (MS including RR-MS and progressive MS), juvenile-onset diabetes mellitus, Hashimoto's thyroiditis, Grave's disease, SLE (systemic lupus erythematosus), Cutaneous Lupus Erythematosus, Sjogren’s syndrome, Pernicious anaemia, Chronic active (lupoid) hepatitis, Rheumatoid arthritis (RA), lupus nephritis, myasthenia gravis, uveitis, refractory uveitis, vernal conjunctivitis, pemphigus vulgaris, scleroderma, optic neuritis, malignant melanoma, alopecia areata, cutaneous sarcoidosis, pain such as radicular pain, pain associated with radiculopathy, neuropathic pain or sciatica/sciatic pain, organ transplantation (prevention of rejection), sarcoidosis, necrobiosis lipoidica or granuloma annulare.”

An “overactive immune system” is a hallmark of much autism and Asperger’s.  I am thinking of all those Aspies with IBS, IBD, ulcerative colitis etc.  There is also the opposite group in autism with those people catching every possible virus and taking a long time to get better.

We have come across an ever-widening variety of anti-inflammatory drugs and do help in certain cases, including:-

·        Cheap NSAIDs, like Ibuprofen
·        The  cheap leukotriene receptor antagonist, Montelukast/Singulair, used to treat children with asthma
·        The Japanese PDE4 inhibitor Ibudilast, used to treat asthma and now MS
·        TSO parasites
·        Lipophilic Statins (Atorvastatin, Lovastatin etc)
·        Beta-lactam antibiotics, like Penicillin
·        Macrolide antibiotics, like Azithromycin (developed interestingly, Natasa, in Croatia by Pliva)
·        Biogaia Gastrus probiotic from Sweden
·        PEA (Palmitoylethanolamide) from Italy or alternatively CBD (Cannabidiol)
·        The ketone BHB (beta hydroxybutyrate)
·        Lenalidomide (an ultra-expensive idea trialed by Dr Chez, in Sacramento)

You will find case histories or small trials that support all of the above therapies, but nothing works for everyone.

Some of the above therapies have side effects, some are cheap and some are very expensive.

I have no doubt that some people with autism would respond to DMF and some will not. People who respond well to BHB ketone supplements could well respond to DMF, because they share one anti-inflammatory mode of action; they are both agonists of Niacin Receptor HCA2/GPR109A. BHB has other anti-inflammatory modes of action and so does DMF. DMF has potent anti-oxidant effects that act via Nrf-2.

We see today that DMF can treat Psoriasis, Multiple Sclerosis (MS) and possibly Parkinson’s Disease and Traumatic Brain Injury (TBI). There is a lot in this blog about COPD (Chronic Oppressive Pulmonary Disease) and via Nrf2, I think DMF looks quite likely to be therapeutic.  You may wonder how these totally different diseases can respond to the same drugs or similar drugs, but it is well known that they do. Otelzla/Apremilast is a very expensive PDE4 inhibitor approved to treat psoriasis; Daxas/Roflumilast is a much cheaper PDE4 inhibitor approved to treat COPD, both cause GI side effects because neither drug is sufficiently selective (there are sub-types of PDE4).

Biogen’s patent for DMF does mention neuropathy and I can say that a much lower dose than they suggest, it can be effective, (based on n=1 trial).

The problems with DMF

I think the main problem with the drug form of DMF is the price.  The active form of DMF, which is called MMF, is also being developed as a drug.

It is suggested that MMF will have less GI side effects than MMF, in part because you would need a lower dose.

DMF needs to be taken in an enteric capsule/coating and with food, or you may get quite extreme GI side effects.

I think low dose DMF (5-10mg) has great potential to treat minor chronic inflammatory conditions.   

The MS dosage of Tecfidera/DMF is usually 240mg twice a day and this brings in $1 billion a year to Biogen.  As usual it us far more expensive in the US than in Europe.

DMF as a chemical is extremely cheap.  You may even find a sachet of DMF inside your old sofa.

Immunomodulation vs Immunosuppression

Even people with an “over-active” immune system get sick and so any therapy to damp down an excessive immune response has to avoid suppressing the immune system.  Ideally you would just modulate the immune system to put it where it should have always been.

Immunomodulation is something that a clever immunologist may be able to help you with, but it is still an emerging area of medicine.


Effects of dimethyl fumarate on neuroprotection and immunomodulation


Background

Neuronal degeneration in multiple sclerosis has been linked to oxidative stress. Dimethyl fumarate is a promising novel oral therapeutic option shown to reduce disease activity and progression in patients with relapsing-remitting multiple sclerosis. These effects are presumed to originate from a combination of immunomodulatory and neuroprotective mechanisms. We aimed to clarify whether neuroprotective concentrations of dimethyl fumarate have immunomodulatory effects.

Findings

We determined time- and concentration-dependent effects of dimethyl fumarate and its metabolite monomethyl fumarate on viability in a model of endogenous neuronal oxidative stress and clarified the mechanism of action by quantitating cellular glutathione content and recycling, nuclear translocation of transcription factors, and the expression of antioxidant genes. We compared this with changes in the cytokine profiles released by stimulated splenocytes measured by ELISPOT technology and analyzed the interactions between neuronal and immune cells and neuronal function and viability in cell death assays and multi-electrode arrays. Our observations show that dimethyl fumarate causes short-lived oxidative stress, which leads to increased levels and nuclear localization of the transcription factor nuclear factor erythroid 2-related factor 2 and a subsequent increase in glutathione synthesis and recycling in neuronal cells. Concentrations that were cytoprotective in neuronal cells had no negative effects on viability of splenocytes but suppressed the production of proinflammatory cytokines in cultures from C57BL/6 and SJL mice and had no effects on neuronal activity in multi-electrode arrays.

Conclusions

These results suggest that immunomodulatory concentrations of dimethyl fumarate can reduce oxidative stress without altering neuronal network activity.

DMF protection involves glutathione recycling

DMF increased the mRNA abundance of various genes involved in the antioxidant response in HT22 cells including the enzymes glutamate-cysteine ligase (GCLC), NQO1, and peroxiredoxin 1, as well as the system Χc- subunit xCT while glutathione S-transferase 1 and heme-oxygenase 1 were downregulated. In primary cortical cultures, only xCT and NQO1 were upregulated by DMF (Figure 2A). We then asked whether inhibition of the function of the most upregulated transcripts, xCT and GCLC with S4-CPG and buthionine sulfoximine (BSO), respectively, abolished the protective activity of DMF. However, DMF was capable of protecting against both compounds (Figure 2B). DMF was also still able to raise glutathione levels when GCLC was inhibited or when system Χc- activity was abrogated by incubation in cysteine-free medium (Figure 2C). Therefore, DMF can still exert protection in neuronal cells when de novo glutathione synthesis is blocked, suggesting that it enhances glutathione recycling.
Our main finding is that DMF at low concentrations protects neuronal cells from oxidative stress by elevating cellular glutathione, and that similar concentrations also reduce production of proinflammatory cytokines from splenocytes. In our experiments, DMF protection needed less time to develop than protection induced by MMF. The induction of the antioxidant response leading to glutathione synthesis seems to be the consequence of an initial and short-lived oxidative stress, since DMF decreased the glutathione content immediately after its addition to the cells. Most likely DMF as an unsaturated carboxylic acid ester initially binds and sequesters glutathione. The long-term effect of DMF in neuronal cells is most probably mediated via Nrf2 as other reported mechanisms such as the inhibition of the nuclear translocation of NF-κB were not evident in these cells and because the increase in GSH synthesis was abolished in cells lacking Nrf2.
In summary, our findings demonstrate that DMF at low concentrations exerts protective effects on neuronal cells and diminishes the production of TNF-α, IL-2, and IL-17 in splenocytes from C57BL/6 mice and the production of all cytokines measured in splenocytes from SJL mice. Although higher concentrations of DMF can cause cell death of primary splenocytes, this is probably not necessary for its immunomodulatory effect. These observations might be relevant for understanding the drug’s presumed mechanism of action as we assume that the active metabolite MMF has similar effects that merely need a longer time to develop.
Here, we first investigated the concentration and time dependence of DMF-mediated protection in neuronal cells using a model of endogenous oxidative stress, oxidative glutamate toxicity, where extracellular glutamate blocks the glutamate-cystine antiporter system Χc-. This leads to deprivation of cystine and its reduced form cysteine, the rate-limiting substrate for the synthesis of glutathione. The subsequent glutathione depletion gives rise to the accumulation of reactive oxygen species and cell death by oxidative stress (recently reviewed [13]). We show herein that neuroprotective concentrations of DMF suppress cytokine production by splenocytes from two different mouse strains without effecting apoptosis and do not impact neuronal network activity studied with dissociated cortical cultures grown on multi-electrode arrays [14] which allows a highly sensitive and reproducible assessment of network activity. Our results suggest that low doses of DMF may promote cellular resistance against oxidative stress and cause immunomodulation independent of T cell apoptosis or alterations in endogenous brain activity.                                                     
Patent for Low Dose DMF
Below is an excerpt from one of Biogen’s patents for DMF.

They are talking about 400mg a day as a low dose, whereas I am talking about a dose of 5-10mg for chronic low-level inflammation.

Pharmaceutical composition containing dimethylfumarate for administration at a low daily dose

Abstract

The present invention relates to pharmaceutical compositions containing dimethyl fumarate (DMF), More specifically, the present invention relates to a pharmaceutical composition for oral use in treating hyperproliferative, inflammatory or autoimmune disorders by administering a low daily dosage in the range of 410 mg±5% or 400 mg±5% dimethyl fumarate, wherein the pharmaceutical formulation is in the form of an erosion matrix tablet.

0044]
The pharmaceutical composition according to any one of the above aspects is for use in the treatment of psoriasis (including moderate to severe plaque psoriasis), psoriatic arthritis, neurodermatitis, inflammatory bowel disease, such as Crohn's disease and ulcerative colitis, polyarthritis, multiple sclerosis including relapsing—remitting multiple sclerosis (MS including RR-MS and progressive MS), juvenile-onset diabetes mellitus, Hashimoto's thyroiditis, Grave's disease, SLE (systemic lupus erythematosus), Cutaneous Lupus Erythematosus, Sjögren's syndrome, Pernicious anemia, Chronic active (lupoid) hepatitis, Rheumatoid arthritis (RA), lupus nephritis, myasthenia gravis, uveitis, refractory uveitis, vernal conjunctivitis, pemphigus vulgaris, scleroderma, optic neuritis, malignant melanoma, alopecia areata, cutaneous sarcoidosis, pain such as radicular pain, pain associated with radiculopathy, neuropathic pain or sciatica/sciatic pain, organ transplantation (prevention of rejection), sarcoidosis, necrobiosis lipoidica or granuloma annulare.

Dimethyl fumarate treatment induces adaptive and innate immune modulation independent of Nrf2

Significance

Dimethyl fumarate (DMF) (BG-12, Tecfidera), a fumaric acid ester (FAE), is a commonly prescribed oral therapy for multiple sclerosis (MS), a CNS autoimmune inflammatory demyelinating disease that may result in sustained neurologic damage. It is thought that the benefit of DMF in MS therapy is mediated through activation of the antioxidative transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway. However, the role of Nrf2 in the antiinflammatory effects of DMF has not been fully elucidated. Here, we investigated the role of Nrf2 in DMF treatment of the MS model, experimental autoimmune encephalomyelitis (EAE), and demonstrated DMF can modulate T cells, B cells, and antigen-presenting cells, and reduce clinical and histologic EAE, independent of Nrf2.

Dimethyl fumarate (DMF) (BG-12, Tecfidera) is a fumaric acid ester (FAE) that was advanced as a multiple sclerosis (MS) therapy largely for potential neuroprotection as it was recognized that FAEs are capable of activating the antioxidative transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway. However, DMF treatment in randomized controlled MS trials was associated with marked reductions in relapse rate and development of active brain MRI lesions, measures considered to reflect CNS inflammation. Here, we investigated the anti-inflammatory contribution of Nrf2 in DMF treatment of the MS model, experimental autoimmune encephalomyelitis (EAE). C57BL/6 wild-type (WT) and Nrf2-deficient (Nrf2−/−) mice were immunized with myelin oligodendrocyte glycoprotein (MOG) peptide 35–55 (p35–55) for EAE induction and treated with oral DMF or vehicle daily. DMF protected WT and Nrf2−/− mice equally well from development of clinical and histologic EAE. The beneficial effect of DMF treatment in Nrf2−/− and WT mice was accompanied by reduced frequencies of IFN-γ and IL-17–producing CD4+ cells and induction of anti-inflammatory M2 (type II) monocytes. DMF also modulated B-cell MHC II expression and reduced the incidence of clinical disease in a B-cell–dependent model of spontaneous CNS autoimmunity. Our observations that oral DMF treatment promoted immune modulation and provided equal clinical benefit in acute EAE in Nrf2−/− and WT mice, suggest that the anti-inflammatory activity of DMF in treatment of MS patients may occur through alternative pathways, independent of Nrf2.

 

DMF probably has multiple therapeutic targets. In this regard, MMF is a potent agonist of the hydroxycarboxylic acid receptor 2 (HCAR2) (GPR109A). It was also observed that HCAR2 deficiency prevented the beneficial effects of DMF treatment in acute EAE in mice, suggesting that HCAR2 may, indeed, be a principal target in DMF therapy of EAE. Our results in this report, highlighting the importance of the Nrf2-independent immunologic and clinical effects of DMF, are complementary with studies that identified HCAR2 as a potential target for DMF. However, the clinical and immunologic effects of DMF treatment of EAE were not completely inhibited by HCAR2 deficiency, indicating that HCAR2 is not the sole target of DMF therapy. One should recognize that the therapeutic response to DMF in MS is dose dependent, and it is possible that individual targets may vary in their sensitivity to different levels of MMF exposure. In this study, the plasma MMF levels obtained in DMF treatment of mice were severalfold higher than those in healthy volunteers treated with DMF doses used in MS. Of interest, when DMF was administered in vivo at a higher dose than was used in either our investigation of Nrf2-deficient mice or the study that evaluated HCAR2-deficient mice, it was observed that a majority of genes induced in spleen cells by DMF treatment were Nrf2 dependent. Thus, in vivo DMF treatment likely mediates its effects through activation of both Nrf2 and HCAR2, and possibly additional targets. Just as MMF covalently attaches to cysteine 151 of Keap1, it also conjugates to other Keap1 cysteine residues and may therefore also modify other cysteine-containing proteins involved in immune regulation. Our results in this report should stimulate exploration for additional potential targets of DMF therapy.

 

DMF/MMF for Parkinson’s Disease?

I found it interesting that the Parkinson’s researchers took a different view of the potential of DMF and its metabolite MMF. They see the merit in using the active substance, the metabolite MMF, as the drug and in doing so reduce the potential for GI side effects.

In the Parkinson’s reality they seek to develop MMF as a drug.

This may well also have something to do with patents and the intellectual property held by Biogen. 

 

Metaboliteof multiple sclerosis drug could be safe, effective therapy for Parkinson's disease


The metabolite of a drug that is helping patients battle multiple sclerosis appears to significantly slow the onset of Parkinson's disease, researchers say.
The oral drug, dimethyl fumarate, or DMF, and its metabolite, monomethylfumarate, or MMF, both increase activity of Nrf2, a protein that helps protect the body from oxidative stress and inflammation, hallmarks of both diseases, said Rd. Bobby Thomas, neuroscientist in the Department of Pharmacology and Toxicology at the Medical College of Georgia at Augusta University.
But the new study provides the first evidence that the metabolite, which is essentially the active portion of the parent drug, more directly targets Nrf2, potentially reducing known side effects of the parent drug that include flushing, diarrhoea, nausea, vomiting, abdominal pain and the brain infection encephalopathy, said Thomas, corresponding author of the study in The Journal of Neuroscience.
Particularly, the gastrointestinal side effects can exacerbate some problems patients with Parkinson's already experience, said Dr. John Morgan, neurologist, neuroscientist and Parkinson's disease specialist in the MCG Department of Neurology. In addition to destroying neurons in the brain that produce dopamine, a neurotransmitter that enables movement and learning, Parkinson's causes nerve cell death in the gastrointestinal tract and related problems such as severe constipation.
"Nrf2 is a natural protective mechanism we have for oxidative stress," Thomas said. The fact that multiple sclerosis and Parkinson's have in common evidence of declining activity of the Nrf2 pathway has generated interest in the drug for Parkinson's and other neurodegenerative diseases.
DMF was approved for multiple sclerosis three years ago by the Food and Drug Administration. While its metabolite MMF is not quite as potent as the parent drug in increasing Nrf2 activity, the new study indicates that its action is sufficient to dramatically slow the loss of dopamine-producing neurons as well as the parent drug, in an animal model of Parkinson's.
In their model, mice given the neurotoxin MPTP experience a dramatic loss of dopamine-producing neurons, losing about half within a handful of days, and rapidly develop Parkinson's-like symptoms. Patients, on the other hand, slowly develop symptoms over many years. By the time they seek medical care, patients may have lost 30-50 percent of their dopaminergic neurons, said Morgan, a study coauthor. "Presentation is after the disease is kind of out of the gate."
To accommodate the very compressed timeline in their model and the fact that several daily doses are needed before the drug starts to work, the researchers first gave the mice either the drug or metabolite the day before they started the toxin.
Dopamine-producing neurons are located in a darker-pigmented central portion of the brain called the substantia nigra. Even in the absence of disease, making dopamine is a stressful job for these neurons that makes them generally more fragile and actually results in oxidative stress even in a healthy scenario, Morgan said. To make a difficult situation worse, increased oxidative stress can make dopamine toxic to neurons, he said.
To increase Nrf2 activity, the parent drug DMF also appears to first make bad matters worse. DMF increases oxidative stress by depleting the natural antioxidant, glutathione, and reduces the power of cell powerhouses, called mitochondria, by limiting their ability to use oxygen and glucose to make energy leading to reduced viability of dopamine-producing cells, Thomas said.
The metabolite MMF appears to more directly activate Nrf2, and actually increases glutathione and improves mitochondrial function, brain cell studies showed. While the parent drug ultimately produces a higher Nrf2 activation, the researchers found the MMF effect was sufficient to stop the dramatic neuron loss in the animal model.
Both DMF and MMF slowed neuron loss to a more normal level, and the neurons that survived continued to make dopamine. Inflammation and oxidative stress levels also were significantly reduced, the researchers said.
As a next step, they are working toward a clinical trial of MMF in patients with early Parkinson's disease. Although the metabolite could be easily formulated for humans, it has not yet been done, Thomas notes.

 

Repurposing the NRF2Activator 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 PDAntioxid. Redox Signal. 25, 61–77.
The global results of this study are presented in an idealized graph in Supplementary Figure S6. It is predicted that overexpression of human α-SYN leads to a rapid, less than 3-week, intoxication of nigrostriatal dopaminergic neurons of Nrf2+/+ and Nrf2−/− mice. This injury is slightly higher in the Nrf2−/− mice (Fig. 3). In parallel to neuron intoxication, we find microglial activation that will elicit an inflammatory response and remove neuronal debris but will cease once α-SYN intoxicated neurons have disappeared. Microglial activation will be lower in DMF-treated Nrf2+/+ mice, because they exhibit less neuron damage (Figs. 5 and 3, respectively). Astrocytes are activated in parallel to neuronal intoxication but contrary to the microglia, they remain detectable after the phase of injury, creating a scar in the damaged tissue (Fig. 4). The astroglial scar is smaller in the DMF-treated mice, because the death of dopaminergic neurons was attenuated by this drug. Further work may be required for obtaining a fine analysis of the participation of DMF and NRF2 in prevention of proteinopathy, but from a clinical perspective, DMF is now ready for clinical analysis for the treatment of PD.


SUPPLEMENTARY FIG. S6. DMF effects on PD mouse model. Diagram of the molecular events triggered by a-SYN and the protective way of action of DMF through NRF2 activation. PD, Parkinson’s disease.
Biogen, maker of Tecfidera, dismissed its lawsuit against Banner in September 2018, in which Biogen claimed that monomethyl fumarate would infringe on patents 7,320,999 and 8,399,514 related to Tecfidera. The FDA’s final approval of monomethyl fumarate is expected once Biogen’s current patent no. 7,619,001 for dimethyl fumarate expires on June 20, 2020.  
A key feature offered by monomethyl fumarate is its lower dose when compared to dimethyl fumarate. Whether a lower dose of a different application of this class of drug will result in fewer side effects is yet to be explored in a clinical trial.  


Immunometabolism as therapeutic target


Dimethyl fumarate (DMF) is an immunomodulatory compound used to treat multiple sclerosis and psoriasis whose mechanisms of action remain only partially understood. Kornberg et al. found that DMF and its metabolite, monomethyl fumarate, succinate the glycolytic enzyme GAPDH (see the Perspective by Matsushita and Pearce). After DMF treatment, GAPDH was inactivated, and aerobic glycolysis was down-regulated in both myeloid and lymphoid cells. This resulted in down-modulated immune responses because inflammatory immune-cell subsets require aerobic glycolysis. Thus, metabolism can serve as a viable therapeutic target in autoimmune disease.
Activated immune cells undergo a metabolic switch to aerobic glycolysis akin to the Warburg effect, thereby presenting a potential therapeutic target in autoimmune disease. Dimethyl fumarate (DMF), a derivative of the Krebs cycle intermediate fumarate, is an immunomodulatory drug used to treat multiple sclerosis and psoriasis. Although its therapeutic mechanism remains uncertain, DMF covalently modifies cysteine residues in a process termed succination. We found that DMF succinates and inactivates the catalytic cysteine of the glycolytic enzyme glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in mice and humans, both in vitro and in vivo. It thereby down-regulates aerobic glycolysis in activated myeloid and lymphoid cells, which mediates its anti-inflammatory effects. Our results provide mechanistic insight into immune modulation by DMF and represent a proof of concept that aerobic glycolysis is a therapeutic target in autoimmunity.
  

Dimethylfumarate inhibits microglial and astrocyticinflammation by suppressing the synthesis of nitric oxide, IL-1β, TNF-α andIL-6 in an in-vitro model of brain inflammation

Background
Brain inflammation plays a central role in multiple sclerosis (MS). Dimethyl fumarate (DMF), the main ingredient of an oral formulation of fumaric acid esters with proven therapeutic efficacy in psoriasis, has recently been found to ameliorate the course of relapsing-remitting MS. Glial cells are the effector cells of neuroinflammation; however, little is known of the effect of DMF on microglia and astrocytes. The purpose of this study was to use an established in vitro model of brain inflammation to determine if DMF modulates the release of neurotoxic molecules from microglia and astrocytes, thus inhibiting glial inflammation.

Methods

Primary microglial and astrocytic cell cultures were prepared from cerebral cortices of neonatal rats. The control cells were treated with LPS, an accepted inducer of pro-inflammatory properties in glial cells, and the experimental groups with LPS and DMF in different concentrations. After stimulation/incubation, the generation of nitric oxide (NO) in the cell culture supernatants was determined by measuring nitrite accumulation in the medium using Griess reagent. After 6 hours of treatment RT-PCR was used to determine transcription levels of iNOS, IL-1β, IL-6 and TNF-α mRNA in microglial and astrocytic cell cultures initially treated with DMF, followed after 30 min by LPS treatment. Moreover, we investigated possible involvement of the ERK and Nrf-2 transduction pathway in microglia using western blot analysis.

Results

Pre-treatment with DMF decreased synthesis of the proinflammatory mediators iNOS, TNF-α, IL-1β and IL-6 at the RNA level in activated microglia and astrocytes in vitro, associated with a decrease in ERK phosphorylation in microglia.

Conclusions

Collectively, these results suggest that the neuroprotective effects of DMF may be in part functionally attributable to the compound's ability to inhibit expression of multiple neuroinflammatory mediators in brain of MS patients.


Systemic inflammation is associated with increased cognitive decline and risk for Alzheimer’s disease. Microglia (MG) activated during systemic inflammation can cause exaggerated neuroinflammatory responses and trigger progressive neurodegeneration. Dimethyl fumarate (DMF) is an FDA-approved therapy for multiple sclerosis. The immunomodulatory and anti-oxidant properties of DMF prompted us to investigate whether DMF has translational potential for the treatment of cognitive impairment associated with systemic inflammation.

Methods

Primary murine MG cultures were stimulated with lipopolysaccharide (LPS) in the absence or presence of DMF. MG cultured from nuclear factor (erythroid-derived 2)-like 2-deficient (Nrf2 −/−) mice were used to examine mechanisms of DMF actions. Conditioned media generated from LPS-primed MG were used to treat hippocampal neuron cultures. Adult C57BL/6 and Nrf2 −/− mice were subjected to peripheral LPS challenge. Acute neuroinflammation, long-term memory function, and reactive astrogliosis were examined to assess therapeutic effects of DMF.

Results

DMF suppressed inflammatory activation of MG induced by LPS. DMF suppressed NF-κB activity through Nrf2-depedent and Nrf2-independent mechanisms in MG. DMF treatment reduced MG-mediated toxicity towards neurons. DMF suppressed brain-derived inflammatory cytokines in mice following peripheral LPS challenge. The suppressive effect of DMF on neuroinflammation was blunted in Nrf2 −/− mice. Importantly, DMF treatment alleviated long-term memory deficits and sustained reactive astrogliosis induced by peripheral LPS challenge. DMF might mitigate neurotoxic astrocytes associated with neuroinflammation.

Conclusions

DMF treatment might protect neurons against toxic microenvironments produced by reactive MG and astrocytes associated with systemic inflammation.

Emerging Understanding of the Mechanism of Action for Dimethyl Fumarate in the Treatment of Multiple Sclerosis

Dimethyl Fumarate Attenuates Neuroinflammation and Neurobehavioral Deficits Induced by Experimental Traumatic Brain Injury


Traumatic brain injury (TBI) is a serious neuropathology that causes secondary injury mechanisms, including dynamic interplay between ischemic, inflammatory, and cytotoxic processes. Fumaric acid esters (FAEs) showed beneficial effects in pre-clinical models of neuroinflammation and toxic oxidative stress, so the aim of the present work was to evaluate the potential beneficial effects of dimethyl fumarate (DMF), the most pharmacologically effective molecules among the FAEs, in a mouse model of TBI induced by controlled cortical impact (CCI). Mice were administered DMF orally at the doses of 1, 10, and 30 mg/kg 1 h and 4 h after CCI. We performed histological, molecular, and immunohistochemistry analysis on the traumatic penumbral areas of the brain 24 h after CCI. DMF treatment notably reduced histological damage and behavioral impairments, reducing neurodegeneration as evidenced by assessments of neuronal loss, Fluoro-Jade C, and TUNEL staining; also, treatment with DMF blocked the apoptosis process increasing B-cell lymphoma 2 (Bcl-2) expression in injured cortex. Further, DMF treatment up-regulated antioxidant Kelch-like ECH-associated protein 1/nuclear factor erythroid 2-related factor pathway, inducing activation of manganese superoxide dismutase and heme-oxygenase-1 and reducing 4-hydroxy-2-nonenal staining. Also, regulating the NF-κB pathway, DMF treatment decreased the severity of inflammation through a modulation of neuronal nitric oxide synthase, interleukin 1, tumor necrosis factor, cyclooxygenase 2, and myeloperoxidase activity, reducing ionized calcium-binding adapter molecule 1 and glial fibrillary acidic protein expression. Our results support the thesis that DMF may be an effective neuroprotectant after brain trauma and warrants further study.


Dimethyl fumarate alters microglia phenotype and protects neurons against proinflammatory toxic microenvironments


Highlights

·         Pharmacokinetic study provides evidence for direct brain exposure of dimethyl fumarates (DMF).
·         DMF, but not monomethyl fumarate (the primary metabolite of DMF) significantly decreases proinflammatory cytokine/chemokine and nitric oxide levels in classically activated microglia culture.
·         The inhibitory effect of DMF on cytokine is NRF2-independent.
·         DMF reduces the toxicity of classically activated microglia towards primary naïve neurons.

Abstract

Delayed-release dimethyl fumarate (DMF) is an approved treatment for multiple sclerosis (MS). Microglia are considered central to MS pathophysiology, however the effects of DMF and the primary metabolite monomethyl fumarate (MMF) on microglia are not well characterized. We demonstrated that DMF and MMF altered transcriptional responses in primary microglia related to the nuclear factor (erythroid-derived 2)-like 2 pathway. Additionally, through an NRF2 independent manner, DMF, but not MMF significantly reduced production of proinflammatory mediators in classically activated microglia, and further rescued mitochondrial respiratory deficits in primary cortical neurons that were induced by activated microglia. These data suggest the mechanism of action of DMF may involve modulation of microglia inflammatory responses and attenuation of neurotoxicity.






Dimethylfumarate inhibits NF-κB function at multiple levels to limit airway smooth muscle cell cytokine secretion


The antipsoriatic dimethylfumarate (DMF) has been anecdotically reported to reduce asthma symptoms and to improve quality of life of asthma patients. DMF decreases the expression of proinflammatory mediators by inhibiting the transcription factor NF-κB and might therefore be of interest for the therapy of inflammatory lung diseases. In this study, we determined the effect of DMF on platelet-derived growth factor (PDGF)-BB- and TNFα-induced asthma-relevant cytokines and NF-κB activation by primary human asthmatic and nonasthmatic airway smooth muscle cells (ASMC). Confluent nonasthmatic and asthmatic ASMC were incubated with DMF (0.1–100 μM) and/or dexamethasone (0.0001–0.1 μM), NF-κB p65 siRNA (100 nM), the NF-κB inhibitor helenalin (1 μM) before stimulation with PDGF-BB or TNFα (10 ng/ml). Cytokine release was measured by ELISA. NF-κB, mitogen and stress-activated kinase (MSK-1), and CREB activation was determined by immunoblotting and EMSA. TNFα-induced eotaxin, RANTES, and IL-6 as well as PDGF-BB-induced IL-6 expression was inhibited by DMF and by dexamethasone from asthmatic and nonasthmatic ASMC, but the combination of both drugs showed no glucocorticoid sparing effect in either of the two groups. NF-κB p65 siRNA and/or the NF-κB inhibitor helenalin reduced PDGF-BB- and TNFα-induced cytokine expression, suggesting the involvement of NF-κB signaling. DMF inhibited TNFα-induced NF-κB p65 phosphorylation, NF-κB nuclear entry, and NF-κB-DNA complex formation, whereas PDGF-BB appeared not to activate NF-κB within 60 min. Both stimuli induced the phosphorylation of MSK-1, NF-κB p65 at Ser276, and CREB, and all were inhibited by DMF. These data suggest that DMF downregulates cytokine secretion not only by inhibiting NF-κB but a wider range of NF-κB-linked signaling proteins, which may explain its potential beneficial effect in asthma. 

Dimethyl Fumarate Reduces Inflammatory Responses in Experimental Colitis


Background and Aims:
Fumaric acid esters have been proven to be effective for the systemic treatment of psoriasis and multiple sclerosis. We aimed to develop a new treatment for colitis.

Methods:
We investigated the effect of dimethylfumarate [DMF, 10-30-100mg/kg] on an experimental model of colitis induced by dinitrobenzene sulphuric acid [DNBS]. We also evaluated the therapeutic activity of 7 weeks’ treatment with DMF [30mg/kg] on 9-week-old IL-10KO mice that spontaneously develop a T helper-1 [Th1]-dependent chronic enterocolitis after birth, that is fully established at 8–10 weeks of age. The mechanism of this pharmacological potential of DMF [10 μM] was investigated in colonic epithelial cell monolayers [Caco-2] exposed to H 2 O 2 . The barrier function was evaluated by the tight junction proteins.
Results:
The treatment with DMF significantly reduced the degree of haemorrhagic diarrhoea and weight loss caused by administration of DNBS. DMF [30 and 100mg/kg] also caused a substantial reduction in the degree of colon injury, in the rise in myeloperoxidase [MPO] activity, and in the increase in tumour necrosis factor [TNF]-α expression, as well as in the up-regulation of ICAM-1 caused by DNBS in the colon. Molecular studies demonstrated that DMF impaired NF-κB signalling via reduced p65 nuclear translocalisation. DMF induced a stronger antioxidant response as evidenced by a higher expression of Mn-superoxide dismutase. Moreover, DMF protected human intestinal epithelial cells against H 2 O 2 -induced barrier dysfunction, restoring ZO-1 occludin expression, via the HO-1 pathway.
Conclusions:
DMF treatment reduces the degree of colitis caused by DNBS. We propose that DMF treatment may be useful in the treatment of inflammatory bowel disease.


Dimethyl fumarate treatment induces adaptive and innate immune modulation independent of Nrf2 

Significance 

Dimethyl fumarate (DMF) (BG-12, Tecfidera), a fumaric acid ester (FAE), is a commonly prescribed oral therapy for multiple sclerosis (MS), a CNS autoimmune inflammatory demyelinating disease that may result in sustained neurologic damage. It is thought that the benefit of DMF in MS therapy is mediated through activation of the antioxidative transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway. However, the role of Nrf2 in the antiinflammatory effects of DMF has not been fully elucidated. Here, we investigated the role of Nrf2 in DMF treatment of the MS model, experimental autoimmune encephalomyelitis (EAE), and demonstrated DMF can modulate T cells, B cells, and antigen-presenting cells, and reduce clinical and histologic EAE, independent of Nrf2.

Abstract

Dimethyl fumarate (DMF) (BG-12, Tecfidera) is a fumaric acid ester (FAE) that was advanced as a multiple sclerosis (MS) therapy largely for potential neuroprotection as it was recognized that FAEs are capable of activating the antioxidative transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway. However, DMF treatment in randomized controlled MS trials was associated with marked reductions in relapse rate and development of active brain MRI lesions, measures considered to reflect CNS inflammation. Here, we investigated the antiinflammatory contribution of Nrf2 in DMF treatment of the MS model, experimental autoimmune encephalomyelitis (EAE). C57BL/6 wild-type (WT) and Nrf2-deficient (Nrf2−/−) mice were immunized with myelin oligodendrocyte glycoprotein (MOG) peptide 35–55 (p35–55) for EAE induction and treated with oral DMF or vehicle daily. DMF protected WT and Nrf2−/− mice equally well from development of clinical and histologic EAE. The beneficial effect of DMF treatment in Nrf2−/− and WT mice was accompanied by reduced frequencies of IFN-γ and IL-17–producing CD4+ cells and induction of antiinflammatory M2 (type II) monocytes. DMF also modulated B-cell MHC II expression and reduced the incidence of clinical disease in a B-cell–dependent model of spontaneous CNS autoimmunity. Our observations that oral DMF treatment promoted immune modulation and provided equal clinical benefit in acute EAE in Nrf2−/− and WT mice, suggest that the antiinflammatory activity of DMF in treatment of MS patients may occur through alternative pathways, independent of Nrf2.

Control of Oxidative Stress and Inflammation in Sickle Cell Disease with the Nrf2 Activator Dimethyl Fumarate


Aims: Heme derived from hemolysis is pro-oxidative and proinflammatory and promotes vaso-occlusion in murine models of sickle cell disease (SCD), suggesting that enhanced detoxification of heme may be beneficial. Nuclear factor erythroid-2-related factor-2 (Nrf2) transcription pathway is the principal cellular defense system responding to pro-oxidative and proinflammatory stress. Dimethyl fumarate (DMF), a drug approved for treatment of multiple sclerosis, provides neuroprotection by activating Nrf2-responsive genes. We hypothesized that induction of Nrf2 with DMF would be beneficial in murine SCD models. Results: DMF (30 mg/kg/day) or vehicle (0.08% methyl cellulose) was administered for 3-7 days to NY1DD and HbSS-Townes SCD mice. Vaso-occlusion, a hallmark of SCD, measured in sickle mice with dorsal skinfold chambers, was inhibited by DMF. The inhibitory effect of DMF was abrogated by the heme oxygenase-1 (HO-1) inhibitor tin protoporphyrin. DMF increased nuclear Nrf2 and cellular mRNA of Nrf2-responsive genes in livers and kidneys. DMF increased heme defenses, including HO-1, haptoglobin, hemopexin, and ferritin heavy chain, although plasma hemoglobin and heme levels were unchanged. DMF decreased markers of inflammation, including nuclear factor-kappa B phospho-p65, adhesion molecules, and toll-like receptor 4. DMF administered for 24 weeks to HbSS-Townes mice decreased hepatic necrosis, inflammatory cytokines, and irregularly shaped erythrocytes and increased hemoglobin F, but did not alter hematocrits, reticulocyte counts, lactate dehydrogenase, plasma heme, or spleen weights, indicating that the beneficial effects of DMF were not attributable to decreased hemolysis. Innovation: These studies identify Nrf2 activation as a new therapeutic target for the treatment of SCD. Conclusion: DMF activates Nrf2, enhances antioxidant defenses, and inhibits inflammation and vaso-occlusion in SCD mice. 


Dimethyl fumarate treatment after traumatic brain injury prevents depletion of antioxidative brain glutathione and confers neuroprotection.

 

Abstract

Dimethyl fumarate (DMF) is an immunomodulatory compound to treat multiple sclerosis and psoriasis with neuroprotective potential. Its mechanism of action involves activation of the antioxidant pathway regulator Nuclear factor erythroid 2-related factor 2 thereby increasing synthesis of the cellular antioxidant glutathione (GSH). The objective of this study was to investigate whether post-traumatic DMF treatment is beneficial after experimental traumatic brain injury (TBI). Adult C57Bl/6 mice were subjected to controlled cortical impact followed by oral administration of DMF (80 mg/kg body weight) or vehicle at 3, 24, 48, and 72 h after the inflicted TBI. At 4 days after lesion (dal), DMF-treated mice displayed less neurological deficits than vehicle-treated mice and reduced histopathological brain damage. At the same time, the TBI-evoked depletion of brain GSH was prevented by DMF treatment. However, nuclear factor erythroid 2-related factor 2 target gene mRNA expression involved in antioxidant and detoxifying pathways was increased in both treatment groups at 4 dal. Blood brain barrier leakage, as assessed by immunoglobulin G extravasation, inflammatory marker mRNA expression, and CD45+ leukocyte infiltration into the perilesional brain tissue was induced by TBI but not significantly altered by DMF treatment. Collectively, our data demonstrate that post-traumatic DMF treatment improves neurological outcome and reduces brain tissue loss in a clinically relevant model of TBI. Our findings suggest that DMF treatment confers neuroprotection after TBI via preservation of brain GSH levels rather than by modulating neuroinflammation.


Emerging Understanding of the Mechanism of Action for Dimethyl Fumarate in the Treatment of Multiple Sclerosis


Dimethyl fumarate (DMF) is an effective treatment option for relapsing–remitting multiple sclerosis (MS), but its therapeutic mechanism of action has not been fully elucidated. A better understanding of its mechanism will allow for the development of assays to monitor its clinical efficacy and safety in patients, as well as guide the development of the next generation of therapies for MS. In order to build the foundation for determining its mechanism, we reviewed the manner in which DMF alters lymphocyte subsets in MS patients, its impact on clinical efficacy and safety, as well as its molecular effects in cellular and animal models. DMF decreases absolute lymphocyte counts, but does not affect all subsets uniformly. CD8+ T-cells are the most profoundly affected, but reduction also occurs in the CD4+ population, particularly within the pro-inflammatory T-helper Th1 and Th17 subsets, creating a bias toward more anti-inflammatory Th2 and regulatory subsets. Similarly, B-lymphocyte, myeloid, and natural killer populations are also shifted toward a more anti-inflammatory stateIn vitro and animal models demonstrate a role for DMF within the central nervous system (CNS) in promoting neuronal survival in an Nrf2 pathway-dependent manner. However, the impact of DMF directly within the CNS of MS patients remains largely unknown.


Conclusion

I think DMF and MMF could have wide application in numerous inflammatory conditions and at much lower doses that those envisaged by Biogen.

No very low dose versions are produced as drugs, the lowest is the 30mg “starter” version for psoriasis. It is not cheap. This tablet can of course be subdivided and placed into enteric capsules to give whatever dose is required and taken after a large meal. Enteric capsules will not dissolve in the gastric acids of the stomach (pH ~3), but they will in the alkaline (pH 7–9) environment present in the small intestine. DMF is an irritant to the stomach and your skin.

Do some of the big-time responders to BHB salts and esters also respond to a tiny dose of DMF? My feeling is that some will.  

It looks like anyone who has oxidative stress and neuroinflammation might potentially benefit and that is most of "autism".  In our case all that is left of allergy-triggered summertime raging/SIB is some anxiety; increasing the NKCC1 blocking with a second daily dose improves cognition but may have a side effect of increasing this anxiety. I was recently asked to fix it. This anxiety disappears with 5mg of DMF, with no side effects. 

There has also been an increase in speech, somewhat reminiscent of what happened several years ago when starting sulforaphane/broccoli sprouts. Sulforaphane and DMF both activate Nrf-2, which functions like an antioxidant switch. The effect of sulforaphane/broccoli sprouts does fade.  

More speech in our case does not mean the social "chit-chat", which you might hope for, but it nonetheless is speech. I was just talking to Monty's assistant about this subject. She is working on developing more conversational speech during some of the free time at school. When your goal is conversational speech you may totally ignore the new speech the student does produce - better to engage in whatever subject he actually does want to "talk" about and build from there.

BHB does have multiple potentially helpful-to-autism modes of action, but so does DMF.

DMF accelerates wound healing, but only in diabetics (this is observed, but not fully understood). Diabetics do suffer foot ulcers that often lead to amputations, so DMF would have a very obvious application.

Neuralgia is a chronic problem affecting many people, DMF may well be an effective new therapy.

It looks like activating the Nrf-2 pathway should protect brains affected by Parkinson’s and maybe these researchers will push for DMF/MMF to get approved.  I do not think anyone has thought of using DMF to treat COPD (severe asthma).  I am glad that at least one paper does mention the potential to use DMF to reduce inflammation in Alzheimer’s.

I think some people with irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD) would very likely respond and MMF is the obvious choice, so as to avoid the GI side effects of DMF.

Even though it is usually stated that DMF is a prodrug while MMF is the active substance, it is clear that this is an over simplification. The effects of DMF and MMF are slightly different.  The effect on GSH (the antioxidant Glutathione) levels is very different, because GSH is consumed in the chemical transition from DMF to MMF, so in the short-term oxidative stress increases if you take DMF.  Perhaps people taking large doses of DMF for Multiple Sclerosis should indeed take NAC to avoid GSH being depleted and also be told not to take Paracetamol for pain (since it further depletes GSH).

For the time being the only commercial product available is DMF.  

Low dose DMF placed in an enteric capsule and taken after a main meal appears to have no GI side effects. It does indeed have an immunomodulatory effect even at a tiny dose of 5 to 8 mg.  Low dose DMF taken without an enteric capsule does have GI effects that you would rather avoid.  I looked up patient feedback from those taking the 100 time higher psoriasis dose of DMF and many report an awful time for the first 2-3 months, before things settle down.

DMF does cause dose dependent side effects. This is why doses far lower than envisaged by Biogen are interesting, if they do actually have a genuine clinical effect in that person. The daily dose for psoriasis is 720 mg. DMF/MMF crosses the blood brain barrier very easily.


DMF, at high psoriasis doses, has been widely used in Germany for many years.

As with many things mentioned in this blog, realistically I doubt much will be made of DMF/MMF in the near future beyond Multiple Sclerosis (MS) and Psoriasis; this is a shame, but not really a surprise.  It does get added to my list of options to modulate the immune system in autism.

·        Cheap NSAIDs, like Ibuprofen
·        The  cheap leukotriene receptor antagonist, Montelukast/Singulair
·        The Japanese PDE4 inhibitor Ibudilast (has less GI side effects than the Western drug Daxas/Roflumilast)
·        TSO parasites
·        Statins
·        Beta-lactam antibiotics, like Penicillin
·        Macrolide antibiotics, like Azithromycin
·        Biogaia Gastrus probiotic
·        PEA (Palmitoylethanolamide) or alternatively CBD (Cannabidiol)
·        The ketone BHB (beta hydroxybutyrate)
·        Lenalidomide (an ultra-expensive drug)
·        5mg DMF (Dimethyl Fumarate) taken in an enteric capsule just after a large meal


All of the above would raise eyebrows as autism therapies, but perhaps less so if you use the term autoimmune encephalopathy.  

The thing to bear in mind is that all the above immuno-modulating therapies have the potential to cause a negative reaction.  You have to match the therapy to the specific immune dysfunction, if indeed there is one at all. Hopefully the field of immunology will move forward and not leave you to ponder these issues yourself. 

I will pursue DMF further.






Thursday, 5 September 2019

Cannabis Use and Potential Epigenetic Damage to Autism Genes


Today we consider another risk factor that may be contributing to the increase in prevalence of autism and it is about the father, for a change.  In the public's perception cannabis is a safe alternative way to treat all kinds of medical problems, many experts do not agree.




Fathers who use marijuana may be using it for two, suggests a study from Duke Medical Center. Although the study is small, encompassing just 24 men and 15 rats, it highlights a potential transgenerational effect of marijuana exposure—the passing on of sperm in which an autism-associated gene, DLGAP2, has accumulated extra epigenetic marks.
The Duke scientists, led by Susan Murphy, PhD, associate professor of obstetrics and gynecology, identified significant hypomethylation at DLGAP2 in the sperm of men who used marijuana compared to controls. A similar observation was made in the sperm of rats exposed to tetrahydrocannabinol (THC) compared to controls. This hypomethylated state was also detected in the forebrain region of rats born to fathers exposed to THC.
Murphy and colleagues said their findings do not establish a definitive link between cannabis use and autism, but the possible connection warrants further, urgent study, given efforts throughout the country to legalize marijuana for recreational and/or medicinal uses.
This study is the first to demonstrate an association between a man’s cannabis use and changes of a gene in sperm that has been implicated in autism,” she emphasized. “Given marijuana’s increasing prevalence of use in the United States and the increasing numbers of states that have legalized its use, we need more studies to understand how this drug is affecting not only those who smoke it, but their unborn children.
“There’s a perception that marijuana is benign. More studies are needed to determine whether that is true.”
The original paper:-

Parental cannabis use has been associated with adverse neurodevelopmental outcomes in offspring, but how such phenotypes are transmitted is largely unknown. Using reduced representation bisulphite sequencing (RRBS), we recently demonstrated that cannabis use is associated with widespread DNA methylation changes in human and rat sperm. Discs-Large Associated Protein 2 (DLGAP2), involved in synapse organization, neuronal signaling, and strongly implicated in autism, exhibited significant hypomethylation (p < 0.05) at 17 CpG sites in human sperm. We successfully validated the differential methylation present in DLGAP2 for nine CpG sites located in intron seven (p < 0.05) using quantitative bisulphite pyrosequencing. Intron 7 DNA methylation and DLGAP2 expression in human conceptal brain tissue were inversely correlated (p < 0.01). Adult male rats exposed to delta-9-tetrahydrocannabinol (THC) showed differential DNA methylation at Dlgap2 in sperm (p < 0.03), as did the nucleus accumbens of rats whose fathers were exposed to THC prior to conception (p < 0.05). Altogether, these results warrant further investigation into the effects of preconception cannabis use in males and the potential effects on subsequent generations.


Conclusion

I do not think anyone should be surprised that the THC in cannabis may leave an epigenetic tag on the DNA of the user and that it is passed down to following generations. We saw a long time ago that the same applies to people who smoke. It is just a question of which genes are most affected.  In the case of smoking it affected how your body deals with oxidative stress and this blocked how drugs for severe asthma (COPD) should work, so making COPD a very big problem for ex-smokers. Stopping smoking does not make the problem go away.

Any kind of prolonged chemical exposure may be a problem, the lead that was used in gasoline/petrol, current use of potent pesticides etc.  The same applies to electrical/magnetic exposure. Best not to live very close to high voltage power lines, or have a mobile phone mast on top of your building.

The concern is that these epigenetic markers are heritable and so accumulate over the generations, a kind of epigenetic pollution.

If great great grandpa worked down a coal mine or in a chemical factory, it may be recorded in your DNA.