Cerebral Folate Deficiency – increasing cerebral folate without increasing plasma/blood folate, via activating the reduced folate carrier (RFC)

 

Source: https://autism.fratnow.com/blog/folate-transport-systems-i-transmembrane-carriers/

Two readers of this blog have been telling me about the fundamental role of brain energy and metabolism in autism. Marco sent me a book called Brain Energy by a psychiatrist at the Harvard Medical School. He stumbled upon this subject when he encouraged a patient to lose weight using the ketogenic diet. As well as losing weight, the patient’s decades-long psychiatric disorders seemed to vanish. The author, Dr Palmer, now believes that many of his patients actually have metabolic disorders as the underlying basis of their psychiatric symptoms. 

Our reader Natasa is approaching with a similar idea, essentially that autism features a brain running on empty.

Today’s post is about increasing the level of folate within the brain, by targeting similar metabolic pathways to those that will boost “brain energy.”

Low levels of folate within the brain will cause varying degrees of neurological disorder.

There are three ways folate can cross into the brain.

1.     Folate receptor alpha (FRA)

2.     Proton-coupled folate transporter (PCFT)

3.     Reduced folate carrier (RFC)

Autoantibodies to the FRA have been linked to neurodevelopmental diseases, particularly cerebral folate deficiency, schizophrenia and autism. Recent studies have shown that these neurodevelopmental disorders can be treated with folinic acid (leucovorin).

Dr Frye, Professor Ramaekers and others are targeting the problem of low folate in the brain by supercharging the level of folate in the bloodstream and hoping more squeezes through the blood brain barrier.

In my previous post I mentioned that Agnieszka has pointed out the idea of using the supplement PQQ. This targets the third transport mechanism above, it is aiming to get more folate across via  the Reduced Folate Carrier (RFC).

Somebody recently wrote their PhD thesis on exactly this topic:- 

Regulation of Folate Transport at the Blood-Brain Barrier: A Novel Strategy for the Treatment of Childhood Neurological Disorders Associated with Cerebral Folate Deficiency

Camille Alam, Department of Pharmaceutical Sciences, University of Toronto 

Additionally, we provided in vitro and in vivo evidence that RFC expression and transport activity is inducible by another transcription factor, NRF-1. These findings demonstrate that augmenting RFC functional expression through interaction with specific transcription factors could constitute a novel strategy for enhancing brain folate delivery. Modulating folate uptake at the BBB may have clinical significance due to the lack of established optimal therapy for neurometabolic disorders caused by loss of FRα or PCFT function. 

What Camille is saying is that if folate transport mechanism number 1 and/or number 2 are not working, we can reinvigorate mechanism number 3.

So if you have Dr Frye’s folate receptor antibodies, or PCFT isn’t working then you might focus on Reduced Folate Carrier (RFC).

The good news is that we have lots of ways to target Reduced Folate Carrier (RFC).

We do not, it seems, have any clever ways to target PCFT. 

NRF-1 and PGC1-alpha

There is a lot in this blog about PGC1-alpha, because it is the master regulator for biogenesis of mitochondria.

All those people with impaired “brain energy” would love to activate PGC1-alpha.

NRF-1 is an activator of mitochondrial respiratory chain genes. NRF-1 specifically targets genes encoding subunits of the mitochondrial respiratory chain complexes, particularly complexes I, III, and IV. By binding to their promoters, NRF-1 directly stimulates their transcription, leading to increased synthesis of these critical protein components and enhanced oxidative phosphorylation (OXPHOS) capacity.

Synergy between NRF-1 and PGC-1alpha

PGC-1alpha acts as the upstream regulator. Various stimuli, such as exercise, cold exposure, and certain hormones, can trigger PGC-1alpha expression. Once activated, PGC-1alpha directly interacts with and co-activates NRF-1, enhancing its binding to target gene promoters and amplifying its transcriptional activity.

NRF-1 as the downstream effector.  NRF-1 fine-tunes the expression of specific mitochondrial genes, ensuring a balanced and efficient OXPHOS system. This synergy between PGC-1alpha and NRF-1 optimizes mitochondrial function and cellular energy production.

So for Natasa, trying to boost energy production in the brain and in the rest of the body, it would be ideal to have more NRF-1 and more PGC-1alpha

What has optimized mitochondrial function got to do with more folate in the brain?

It turns out that you can increase expression of Reduced Folate Carrier (RFC) via activating NRF-1 and/or PGC1alpha.

So what is good for your brain energy is likely to also be good for your brain folate.

Nuclear respiratory factor 1 (NRF-1) upregulates the expression and function of reduced folate carrier (RFC) at the blood-brain barrier

Folates are important for neurodevelopment and cognitive function. Folate transport across biological membranes is mediated by three major pathways: folate receptor alpha (FRα), proton-coupled folate transporter (PCFT), and reduced folate carrier (RFC). Brain folate transport primarily occurs at the choroid plexus through FRα and PCFT; inactivation of these transport systems results in suboptimal folate levels in the cerebrospinal fluid (CSF) causing childhood neurological disorders. Our group has reported that upregulation of RFC at the blood-brain barrier (BBB) through interactions with specific transcription factors, that is, vitamin D receptor (VDR) could increase brain folate delivery. This study investigates the role of nuclear respiratory factor 1 (NRF-1) in the regulation of RFC at the BBB. Activation of NRF-1/PGC-1α signaling through treatment with its specific ligand, pyrroloquinoline quinone (PQQ), significantly induced RFC expression and transport activity in hCMEC/D3 cells. In contrast, transfection with NRF-1 or PGC-1α targeting siRNA downregulated RFC functional expression in the same cell system. Applying chromatin immunoprecipitation (ChIP) assay, we further demonstrated that PQQ treatment increased NRF-1 binding to putative NRF-1 binding sites within the SLC19A1 promoter, which encodes for RFC. Additionally, in vivo treatment of wild type mice with PQQ-induced RFC expression in isolated mouse brain capillaries. Together, these findings demonstrate that NRF-1/PGC-1α activation by PQQ upregulates RFC functional expression at the BBB and could potentially enhance brain folate uptake.

The hugely simple intervention mentioned above is to just take vitamin D. This has nothing to do with brain energy.

Upregulation of reduced folate carrier by vitamin D enhances brain folate uptake in mice lacking folate receptor alpha

Folates are critical for brain development and function. Abnormalities in brain folate transport have been implicated in a number of childhood neurodevelopmental disorders, including cerebral folate deficiency syndrome, hereditary folate malabsorption, and autism spectrum disorders. These disorders have devastating effects in young children, and current therapeutic approaches are not sufficiently effective. In this study, we demonstrate that functional expression of the folate transporter, reduced folate carrier, at the blood–brain barrier and its upregulation by the vitamin D nuclear receptor can remarkably increase folate transport to the brain. These findings provide a strategy for enhancing brain folate delivery for the treatment of neurometabolic disorders caused by folate transport defects.

 Low vitamin D correlates with poor health, dementia, and death from all causes

Taking vitamin D has become popular in recent years.

A correlation does not guarantee causality.  It was thought that vitamin D might be the silver bullet to improved health in older people. It has not proved to be.

Low vitamin D also correlates with less time outdoors, doing some physical activity. Taking vitamin D does not mean you will live longer, but we know for sure that exercise improves many medical concerns that will improve healthy life expectancy.

The concern many people now have regarding skin cancer leads to some healthy active people having low vitamin D. Put on that sunscreen and your exposed skin will not be able to produce your vitamin D.

Vitamin D is important to health and is easy to maintain in the normal range, but it is just one element of good health. It might be one way to increase folate in the brain, for those who need it. 

 

Conclusion

How do you increase folate in the brain?

The obvious way is to put more folate in your blood, this is the standard therapy. You either take calcium folinate tablets or, very rarely, the more potent infusions.

If you have antibodies blocking transport via FRA, you could follow the hypothesis that these antibodies are from a reaction to cow’s milk and try going dairy-free. There is a complex relationship between milk and folate receptor alpha antibodies (FRAA), but direct evidence of milk causing FRAA production is limited.

Milk, particularly cow's milk, contains proteins similar to folate receptor alpha found in humans. Some individuals, mainly those with a genetic predisposition, could develop FRAA that cross-react with these milk proteins. This cross-reactivity would not necessarily mean the milk directly caused FRAA production but might trigger an existing immune response. Some studies, though not all, have found an association between higher milk consumption and increased FRAA levels.

If you want to increase folate transport via our third mechanism, Reduced Folate Carrier (RFC) you have many options:

The obvious first step is to take a vitamin D supplement to raise levels to the high end of normal. This can be done by taking a larger supplement just once a week, because vitamin D has a long half-life.

As you can see from the study below in children there is a correlation between low vitamin D and low folate in children.

 

Evaluation of correlation between vitamin D with vitamin B₁₂ and folate in children

The present study reported a positive correlation between vitamin D and vitamin B12 and folate levels. Regular measurement of these two micronutrient levels in children with vitamin D deficiency is important for public health.

Vitamin D is low in much of the population, even more so in wintertime. It seems particularly low in children with autism, perhaps because they are spending less time playing outside than other children.

Activate NRF-1 and/or PGC1alpha:

1.     Exercise, particularly endurance training

2.     PQQ supplement

3.     Perhaps resveratrol/pterostilbene

4.     Butyric acid / sodium butyrate

5.     The very safe old drug Metformin

6.     Other type 2 diabetes drugs like Pioglitazone

Metformin has been shown to raise IQ in Fragile-X by about 10 points and has a range of metabolic benefits and even cancer preventative effects. This common diabetes medication primarily targets AMPK, an energy sensor molecule upstream of PGC-1alpha. By activating AMPK, metformin indirectly stimulates PGC-1alpha and subsequently NRF1, leading to enhanced mitochondrial function.

Pioglitazone has been researched in autism and is my choice for peak risk spring/summer aggression and self-injury. Pioglitazone can potentially upregulate PGC-1alpha expression through several pathways:

•                    Pioglitazone activates AMPK, an important energy sensor molecule. AMPK can then stimulate PGC-1alpha expression through various signaling pathways.

•                    Pioglitazone activates PPAR-gamma and PPAR-gamma directly interacts with PGC-1alpha, potentially increasing its activity.

I think Metformin has a better safety profile than Pioglitazone and so better for every day use.

Butyric acid does have the potential to activate PGC-1alpha. Butyric acid is produced in the gut by fermentation. You need “good” bacteria and fiber. People with healthy diet naturally produce it. You can also buy it as a supplement (sodium butyrate) since it has numerous benefits – everything from gut health, bone health to a tight blood brain barrier.

According to a doctor I was talking to recently, nobody wants to hear that exercise is a key part of health. It is free and the side effects are generally all good ones. Endurance exercise will boost NRF1 and PGC1alpha. Many people with autism are overweight, often due to the psychiatric drugs they have been put on.

Sirtuin activators boost NRF1 and PGC1 alpha. There are drugs and foods which can do this, but a potent way is through exercise.

I hope Dr Frye is checking his patients’ vitamin D levels and supplementing to the safe upper limit.

Those taking I/V calcium folinate might want to look at the more potent ways to activate NRF1 and/or PGC1alpha.

 

DMF for Mitochondrial Dysfunction in Autism and Friedreich's Ataxia?

Yet more money was just donated to autism research. In 2017 the CEO of Broadcom gave $20 million to MIT and now he has given $20 million to Harvard, where he did his MBA.

Time to boost Homer's mitochondria?

I think philanthropists from the fast-moving IT sector should demand rather more from the slow-moving world of autism research.  I also think common sense is often more lacking than money.

The US Government has also just announced $1.8 billion for autism research.

Donald Trump authorized a five-year extension of the Autism Collaboration, Accountability, Research, Education and Support (CARES) Act. The 2014 act dedicated funds to children with autism spectrum disorder, but the new version includes adults.  Children with autism do indeed grow up to become adults with autism. 

Today we look at further applications of DMF, which is a cheap chemical also sold as a very expensive drug.

We learnt from Dr Kelley, from Johns Hopkins, that most regressive autism features mitochondrial dysfunction. Mitochondria within cells produce ATP (fuel) via a complex multi-step process called OXPHOS. If you lack any of the required enzyme complexes for OXPHOS, that part of your body will suffer a power shortage/outage.  Another potential problem is just too few mitochondria.

The treatment for mitochondrial disease is mainly to avoid further damage, using antioxidants.  If you know which enzyme complex is lacking, you might try and target that.

We saw a long time ago in this blog that PGC-1α is the master regulator of mitochondrial biogenesis and as such this would be a target for people with mitochondrial dysfunction.

Among other interactions, PGC-1α is affected by something called PPAR-γ (Peroxisome proliferator-activated receptor gamma), also known as the glitazone receptor.

There are many cheap drugs that target PPAR-γ, because this is also one way to treat type 2 diabetes.  We saw that Glitazone drugs have been successfully trialed in autism.

Today we look at another way to activate PGC-1α and stimulate the production of more mitochondria and increase the necessary enzyme complexes for OXPHOS.

Many people with autism in the US are diagnosed by their MAPS/DAN doctor as lacking Complex 1.

DMF has two principal effects. It affects NRF2 and HCAR2.

Many supplements sold online are supposed to activate NRF2, but may well lack potency.

Activating NRF2 turns on your antioxidant defences and so is good for people with autism, diabetes, COPD and many other conditions, but is bad for someone with cancer.

We will see later how, somewhat bizarrely, at high doses DMF reverses function and causes cell death via oxidative stress, making it a potent potential cancer therapy.  Cancer cells are highly vulnerable to oxidative stress.

In this blog we are focusing on low doses of DMF, that are NRF2 activating.

In the chart below the NFE2L2 gene encodes the transcription factor NRF2. We want the antioxidant genes turned on.

We then get another benefit because NRF2 expression also regulates NRF1 expression.

The transcription factor NRF1 is another regulator of mitochondrial biogenesis with involvements in mitochondrial replication  and transcription of mitochondrial DNA.

We then get a third benefit from DMF via activating HCAR2, this time we increase Complex I expression.  In the OXPOS multistep process to make fuel/ATP the bottleneck is usually Complex I, so Complex I is often referred to as being “rate limiting”. Complex I is the most important deficiency to fix.

Dimethyl fumarate mediates Nrf2-dependent mitochondrial biogenesis in mice and humans

The induction of mitochondrial biogenesis could potentially alleviate mitochondrial and muscle disease. We show here that dimethyl fumarate (DMF) dose-dependently induces mitochondrial biogenesis and function dosed to cells in vitro, and also dosed in vivo to mice and humans. The induction of mitochondrial gene expression is more dependent on DMF's target Nrf2 than hydroxycarboxylic acid receptor 2 (HCAR2). Thus, DMF induces mitochondrial biogenesis primarily through its action on Nrf2, and is the first drug demonstrated to increase mitochondrial biogenesis with in vivo human dosing. This is the first demonstration that mitochondrial biogenesis is deficient in Multiple Sclerosis patients, which could have implications for MS pathophysiology and therapy. The observation that DMF stimulates mitochondrial biogenesis, gene expression and function suggests that it could be considered for mitochondrial disease therapy and/or therapy in muscle disease in which mitochondrial function is important.

                                                                                                                    

DMF for Friedreich's ataxia

Friedreich's ataxia (FA) is a genetic disease caused by mutations in the FXN gene on the chromosome 9, which produces a protein called frataxin. It causes difficulty walking, a loss of sensation in the arms and legs and impaired speech that worsens over time. Symptoms typically start between 5 and 15 years of age. Most young people diagnosed with FA require a mobility aid such as a wheelchair by their teens. As the disease progresses, people lose their sight and hearing. Other complications include scoliosis and diabetes.

Frataxin is required for the normal functioning of mitochondria, the energy-producing factories of cells. Mutations in the FXN gene lead to a decrease in the production of frataxin and the consequent disruption in mitochondrial function.

No effective treatment exists. FA shortens life expectancy due to heart disease, but some people can live into their sixties.

Dimethyl fumarate dosing in humans increases frataxin expression: A potential therapy for Friedreich's Ataxia.

Friedreich’s Ataxia (FA) is an inherited neurodegenerative disorder resulting from decreased expression of the mitochondrial protein frataxin, for which there is no approved therapy. High throughput screening of clinically used drugs identified Dimethyl fumarate (DMF) as protective in FA patient cells. Here we demonstrate that DMF significantly increases frataxin gene (FXN) expression in FA cell model, FA mouse model and in DMF treated humans. DMF also rescues mitochondrial biogenesis deficiency in FA-patient derived cell model. We further examined the mechanism of DMF's frataxin induction in FA patient cells. It has been shown that transcription-inhibitory R-loops form at GAA expansion mutations, thus decreasing FXN expression. In FA patient cells, we demonstrate that DMF significantly increases transcription initiation. As a potential consequence, we observe significant reduction in both R-loop formation and transcriptional pausing thereby significantly increasing FXN expression. Lastly, DMF dosed Multiple Sclerosis (MS) patients showed significant increase in FXN expression by ~85%. Since inherited deficiency in FXN is the primary cause of FA, and DMF is demonstrated to increase FXN expression in humans, DMF could be considered for Friedreich's therapy.

High Dose DMF to treat some cancer

Some readers may recall that the protein DJ-1 is encoded by the Parkinson’s gene PARK7 and that DMF has already been proposed as a therapy for Parkinson’s disease. 

At high doses of DMF the protein DJ-1 loses its stabilization function and ends up effectively blocking NRF2. Put simply, high dose DMF turns off NRF2, making it a cancer cell killer.

Dimethyl Fumarate Controls the NRF2/DJ-1Axis in Cancer Cells: Therapeutic Applications

The transcription factor NRF2 (NFE2L2), regulates important antioxidant and cytoprotective genes. It enhances cancer cell proliferation and promotes chemoresistance in several cancers. Dimethyl fumarate (DMF) is known to promote NRF2 activity in noncancer models. We combined in vitro and in vivo methods to examine the effect of DMF on cancer cell death and the activation of the NRF2 antioxidant pathway. We demonstrated that at lower concentrations (<25 a="" activation="" antioxidant="" cytoprotective="" dmf="" has="" mol="" nrf2="" of="" pathway.="" role="" span="" the="" through=""> At higher concentrations, however (>25 μmol/L), DMF caused oxidative stress and subsequently cytotoxicity in several cancer cell lines. High DMF concentration decreases nuclear translocation of NRF2 and production of its downstream targets. The pro-oxidative and cytotoxic effects of high concentration of DMF were abrogated by overexpression of NRF2 in OVCAR3 cells, suggesting that DMF cytotoxicity is dependent of NRF2 depletion. High concentrations of DMF decreased the expression of DJ-1, a NRF2 protein stabilizer. Using DJ-1 siRNA and expression vector, we observed that the expression level of DJ-1 controls NRF2 activation, antioxidant defenses, and cell death in OVCAR3 cells. Finally, antitumoral effect of daily DMF (20 mg/kg) was also observed in vivo in two mice models of colon cancer. Taken together, these findings implicate the effect of DJ-1 on NRF2 in cancer development and identify DMF as a dose-dependent modulator of both NRF2 and DJ-1, which may be useful in exploiting the therapeutic potential of these endogenous antioxidants.

Proposed mechanism of DMF-induced cancer cell death. Low concentrations of DMF can induce the NRF2 antioxidant pathway, allowing NRF2 nuclear translocation and binding to the antioxidant response elements leading to the transcription of antioxidant and detoxifying enzymes, thereby promoting cell survival. High concentrations of DMF, however, induce disruption of the NRF2 stabilizer DJ-1, which in turn impairs NRF2 induction and transcriptional activities in response to DMF, induces ROS generation, GSH depletion, and hence, facilitates cancer cell death. Cys, cysteine; 2SC, succination of cysteine residues.

Conclusion

This post did not cost $20 million, it is yours for free.

It looks pretty obvious that people with autism caused by, or associated with, mitochondrial dysfunction might potentially benefit from DMF.

People with Friedreich’s Ataxia do not currently have any treatment options. Low dose DMF is free of side effects, the high doses used to treat Psoriasis and Multiple Sclerosis often cause troubling GI side effects.

DMF seems to have very many potential therapeutic applications, limited only by the cost of the pharmaceutical version of this cheap chemical. Fortunately the "autism dose" is tiny.


Related Earlier Posts

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

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