Leaky ATP from either Mitochondria or Neurons in Fragile X and Autism

 

 

For leaky ATP, Popeye might want to try Dexpramipexole and

Suramin, or even the already approved Mirapex

If you are old enough to be a parent, you will have encountered problems with some kind of leak.  A leaky roof, a leaky pipe, a leaky washing machine, an air-conditioning unit... The list goes on, the older you get.

I have been preoccupied by fixing a leak recently.  We have a large roof terrace and, in the winter, water started leaking from the ceiling in the floor below.  I improvised a system to catch all the water, but still I had to find the source of the leak.

I did finally find the source of the problem and most importantly without digging up 95% of the terrace.  Now I have to put the 5% back together again.

Leaks are often extremely difficult to locate, because water always finds the easiest path and the dripping you see might have originated from a leak far away.  Nobody wants to fix leaks, because it can be a pretty thankless task and you can cause plenty of damage in the process, without solving the problem.  So, as with fixing autism, I ended up doing much of the fixing myself.  The damage had actually been there since the house was built, hidden under ceramic tiles.

I recently read about leaky ATP in Fragile-X, where ATP leaks from the mitochondria into the cell.

This fits neatly into Professor Naviaux’s belief that ATP is leaking from the cell into the extracellular space, as the basis for his concept of the cell danger response, as a unifying and treatable feature of most autism.

Sounds complicated?

Just think of it as bunch of leaks you need to fix.

 

 What is ATP? 

ATP has many functions:- 

·        It is the fuel your cells need to function.

·        It is a signalling molecule within a cell and importantly between different cells.

·        It is used to make your DNA

  

Mitochondria

Each cell in your brain contains many mitochondria and these are where ATP is produced. Mitochondria die and are replaced, whereas if the host brain cell dies, it is lost forever. Cell death in the brain is bad news.

The ATP – ADP Cycle 

You can think of ATP as a fully charged battery.  Once the energy has been used up the flat battery is called ADP and it goes back for recharging in the mitochondria.  It is a continuous cycle.

ADP is powered back to ATP through the process of releasing the chemical energy available in food; this is constantly performed via aerobic respiration in the mitochondria. This process is also called OXPHOS and has been covered in previous posts.  In most mitochondrial disease the problem is that one of the four mitochondrial enzyme complexes is insufficient; this means that the ATP-ADP cycle is restricted.  There is then insufficient energy to power the brain in times of peak energy requirement.  This can cause loss of myelination and ultimately cell death.

 

  

ATP in Fragile X

It looks like in Fragile X the mitochondria in the brain do not work properly. ATP is leaking from the mitochondria and this stops synapses from maturing. 

A synapse is just the junction between one neuron and its neighbour.

The immature synapse manifests as autistic behavior.  When you plug the leak with Dexpramipexole, a drug trialed for ALS and now asthma, dendritic spines mature and autistic behavior is reduced.

To what extent this leakage occurs in idiopathic autism is unknown, but we know that impaired dendritic spine formation/morphology is a key feature of most autism and that it can be modified, although the sooner you start the better the result will be.

It looks to me that some people diagnosed with mitochondrial disease based on blood tests may actually have leaking ATP which then affects metabolic pathways and shows up with odd blood test results, that is then misdiagnosed as mitochondrial disease.  Note that many people diagnosed with mitochondrial disease show no response to therapy.

In Professor Naviaux’s theory, the ATP leak is from the cell membrane, like the outer wall of the cell.  He thinks that ATP is leaking and this then sends a false danger signal to the rest of your brain.  This is his Cell Danger Response (CDR).  Because the brain thinks it is under attack it is set in a permanent pro-inflammatory state, this gets in the way of basic functions the developing brain needs to complete.  This might explain why the microglia (the brain’s immune cells) are found to be permanently activated in autism; this then means that they do not carry out their regular brain housekeeping activities very well, like pruning synapses.

Naviaux wants to plug the leaks in the cell wall using Suramin, which is an old anti-parasite drug made by Bayer, the giant German company.

The link between the Fragile X research from Yale and Naviaux’s work at UCSD is that ATP needs to be kept in the right place for the brain to function correctly.

Leaky ATP will cause you big problems.

 

 

Now for the supporting research

 

Leaky ATP in Fragile X

 

Fragile X syndrome traits may stem from leaky mitochondria

The persistent leak influences which metabolic pathway the cell uses to generate energy, the team discovered by using a technique called mass spectrometry. For example, fragile X neurons produce more enzymes associated with glycolysis — a pathway commonly used by immature cells — than do typical neurons. Previous studies have shown altered mitochondrial metabolism in people with other forms of autism2.

Adding dexpramipexole to the cells of fragile X mice decreased production of lactate dehydrogenase and other enzymes linked to glycolysis, suggesting that closing the leak causes the neurons to start to use different, more mature metabolic pathways.

Giving injections of dexpramipexole to fragile X model mice lessened their hyperactivity, repetitive behaviors and excessive grooming — traits that are reminiscent of those seen in people with autism and in those with fragile X syndrome. Mice that received the dexpramipexole injections also had neurons with more mature dendritic spines and decreased levels of protein synthesis.

Dexpramipexole has been tested in people with the neurological disease amyotrophic lateral sclerosis and found safe, but it is unclear how it would affect young people if taken over sustained periods of time.

 

ATP Synthase c-Subunit Leak Causes Aberrant Cellular Metabolism in Fragile X Syndrome

Loss of the gene (Fmr1) encoding Fragile X mental retardation protein (FMRP) causes increased mRNA translation and aberrant synaptic development. We find neurons of the Fmr1^-/y mouse have a mitochondrial inner membrane leak contributing to a "leak metabolism." In human Fragile X syndrome (FXS) fibroblasts and in Fmr1^-/y mouse neurons, closure of the ATP synthase leak channel by mild depletion of its c-subunit or pharmacological inhibition normalizes stimulus-induced and constitutive mRNA translation rate, decreases lactate and key glycolytic and tricarboxylic acid (TCA) cycle enzyme levels, and triggers synapse maturation. FMRP regulates leak closure in wild-type (WT), but not FX synapses, by stimulus-dependent ATP synthase β subunit translation; this increases the ratio of ATP synthase enzyme to its c-subunit, enhancing ATP production efficiency and synaptic growth. In contrast, in FXS, inability to close developmental c-subunit leak prevents stimulus-dependent synaptic maturation. Therefore, ATP synthase c-subunit leak closure encourages development and attenuates autistic behaviors.

 

Highlights 

·        ATP synthase c-subunit leak in Fragile X causes aberrant metabolism

·        Changes in ATP synthase component stoichiometry regulate protein synthesis rate

·        Inhibition of the leak normalizes synaptic spine morphology and Fragile X behavior

 

In Brief

Lack of FMRP in Fragile X neurons is associated with a leak in the ATP synthase, the blockade of which normalizes cellular and behavioral disease phenotypes.

 

Now they fix the leak using Dexpramipexole (Dex) and cyclosporine A (CsA)

 

 

We have found that the mitochondrial inner membrane leak of FX neurons and cells is caused by abnormal levels of ATP synthase c-subunit. The c-subunit leak causes persistence of a mitochondrial leak metabolic phenotype characterized by high glycolytic flux, high lactate levels, and increased levels of glycolytic and TCA enzymes. The leak also aberrantly elevates overall and specific protein synthesis; a decrease in c-subunit level or pharmacological inhibition of the ATP synthase leak reduces protein synthesis rates and decreases the levels of leak metabolism enzymes. In Fmr1/y synapses, stimulation-dependent protein synthesis is absent. This is correlated with a lack of stimulus induced EF2 phosphorylation and a lack of synthesis of the ATP synthase b-subunit. These abnormalities are readily reversed by ATP synthase leak inhibitors, suggesting that leak closure is required for the ATP-dependent phosphorylation of EF2 adjacent to mitochondria. EF2 phosphorylation may regulate the change in subsets of proteins synthesized and may be correlated with- the overabundant synthesis of enzymes supporting a high flux glycolytic/TCA cycle ‘‘leak’’ metabolism indicative of metabolic immaturity. Consistent with the hypothesis that the c-subunit leak is also a major cause of synapse immaturity, we find that inhibition of the ATP synthase leak allows the maturation of synapses and normalizes autistic behaviors.

 

 

 

Closing Leaky Mitochondria Halts Behavioral Problems in Fragile X, Study Suggests

“In Fragile X neurons, the synapses fail to mature during development. The synapses remain in an immature state and this seems to be related to their immature metabolism,” she said.

The investigators tested whether closing the leak to boost the efficiency of ATP production would lessen behavioral abnormalities.

They first saw that nerve cells treated with an ATP synthase inhibitor named dexpramipexole (Dex) — a form of the common Parkinson’s therapy Mirapex ER (pramipexole) and previously tested as a treatment for amyotrophic lateral sclerosis — increased the levels of ATP.

Two-day treatment with Dex also reversed autistic-like behaviors, namely excessive time spent grooming and compulsive shredding of the animals’ nests. The treatment also reduced hyperactivate behaviors.

“We find that inhibition of the ATP synthase leak allows for the maturation of synapses and normalizes autistic behaviors in a mouse model of [fragile X],” the team wrote.

Jonas and her team now intend to further test the effectiveness of this and other leak-closing therapies for improving learning.

The lab is conducting a study assessing the role of leaky membranes in memory formation. Findings could pave the way for novel therapeutics for fragile X and autism, as well as for Alzheimer’s disease.

 

 

 

Dr Naviaux and Suramin for Autism

 

I have covered Suramin in previous posts.  There is a presentation below by Prof Naviaux that is for lay people, it is good to hear directly from the man himself.

 

Autism Treatment, the cell danger response and the SAT1 trial

https://youtu.be/pqd_BoCeRUw

In essence he says that when cells are stressed, they leak ATP and this creates the cell danger response.  If you have suramin in your bloodstream, it plugs the ATP channels and stops it leaking out of the cell and so blocks the cell danger response.

It is the cell danger response that is causing the symptoms we see as autism.

  

Conclusion

Who to call to fix an ATP leak?

If it is a case of Fragile X, there looks to be potential solution, but you will definitely not find it at your local doctor’s office.

For a mouse with Fragile X, you might choose Dexpramipexole.  Dexpramipexole was developed as a therapy for ALS (motor neuron disease), but failed in phase 3 trials and is now being developed for asthma.

For a human, the logical place to start would be the already approved Mirapex, which is currently used to treat Parkinson's disease and restless legs syndrome.

Mirapex - a miracle for Fragile X?

Clearly somebody should make a clinical trial of the existing drug.

I expect what will happen is that the Yale researchers will come up will a new drug that can be patented as a novel therapy for Fragile X.  This way they get to make some money, but a decade is wasted.

Is leaky ATP from mitochondria an issue in broader autism, beyond Fragile X? That is still unknown, but the Yale researchers seem to think their work has potential application in both autism and Alzheimer’s.

In the case of broader autism, Dr Naviaux and his partner Kuzani have some competition from Paxmedica.  Both groups seek to monetize Dr Naviaux’s published research.

It looks like the German giant Bayer does not want to help either group.  Instead of just tapping into Bayer’s existing production of Suramin, Kuzani and Paxmedica will have to figure out how to produce Suramin.

This all helps us to understand why there still are no approved therapies for core Autism or indeed Fragile X and yet there is a mountain of research.  Too many barriers and interests to overcome.

If you want to fix leaky ATP any time soon, you will be doing it mainly by yourself.  This has been my experience with most other kinds of leak!

 

 

Game Changer or Fine Tuning? It depends on severity of Autism

 

There are so many possible autism interventions discussed in this blog, it clearly is not always easy to know their relative merit.

There are so many people now diagnosed with autism it is no longer such a meaningful term.  The most extreme autism I think I will have to start calling really severe autism.  A scale of 1 to 100 would be much more helpful than the current levels 1, 2 or 3. I suppose Elon Musk and Greta are level 1.

One reader did recent describe the effects of bumetanide in his child as being game changing.  I think it is an excellent description to use.  For our reader Roger, Leucovorin was a game changer.

Another reader wrote to me to give an update about his three year old

“After 3 months of bumetanide treatment I've seen improvement on his cognition, like, he is now able to finish an apple and take the end to the trash by himself or enter in his room, turn the lights on, take some toy, turn lights off and close the door or eat his lunch by himself. He is smarter now.”

This reader is well on his way to finding the additional elements for his son’s personalized polytherapy and the way he is going about it is likely to yield optimal results. Most of what you need is tucked away in this blog somewhere.  It is a case of who dares wins.

Using my scale of 1 to 100, with Elon and Greta in low single digits and many people referred to at the blog of the US National Council of Severe Autism mainly at 80-100, we can put interventions into a bit more perspective.

It is still far from perfect because most people with really severe autism reach a plateau in development at a very young age.  This matters because as a three year old they do not look/behave so differently to a typical child, but by the time they reach 18 years old, the difference is gigantic.

If you could delay the onset of this developmental plateau for a decade the result would be transformative.  Based on the longitudinal studies to adulthood, it looks like about 80% of severe autism reaches a plateau at the level of a 2-3 year old.  The other 20% continue to learn, but at a slower rate than typical children. 

In the case of the autism which is <10, like Greta and Elon, very small issues can still become very troubling.  There was inevitably bullying at school from mild to severe, there likely was (and still is) anxiety, perhaps an eating disorder, perhaps some self harming or even suicidal thoughts.

If you fine tune the brain a little to reduce anxiety and improve social/emotional responsiveness, you can trim someone’s score from a 15 to a 9 and make them feel much better.  Job done.

For someone with an IQ of 50 (i.e. severe intellectual disability), non-verbal, non-literate, who is sometimes aggressive and exhibits autistic behaviors, you are going to need much more than fine tuning, you need a game changer.  Then you can go on and fine tune things to give further incremental improvement.

One doctor reader did suggest to me that, in effect, five moderately effective interventions might equal one game changer.

In the case of autism that I deal with, the most important step was raising cognitive function, not treating what people consider to be autism.  I think that this applies to almost all people with a score 50 to 100.  Even if it was never actually diagnosed, the barrier to progress is low cognitive function and a severely reduced ability to learn and acquire new skills.  This has to be fixed and for many people the tools already exist.

 

Improving cognitive function

Game Changer

·      Bumetanide  (also Azosemide, KBr and, possibly, Betaine with the same effect of lowering chloride inside neurons)

Fine tuning

·      Atorvastatin, reducing cognitive inhibition

·      Micro-dose Clonazepam, shift E/I imbalance

·      Low-dose Roflumilast, raising IQ

 

Reducing autistic behaviors

Fine tuning

·      NAC

·      Sulforaphane

·      Verapamil

·      Oxytocin

·      BHB

·      Pentoxifylline

·      Agmatine

·      Clemastine

·      DMF

·      Leucovorin (Calcium Folinate)

 

Interventions with a slow course of action

Some interventions, for example pro-myelinating therapies (like clemastine and Tyler’s N-acetylglucosamine), or pro-autophagy therapies, may take a long time to show effect. I think you may need to first see very tangible results from other therapies, which are much easier to assess.

As Roger will want to point out, in the case of Cerebral Folate Deficiency Leucovorin was the game changer.

In the case of other metabolic autisms, a single therapy may also be the game changer, like the Greek boy for whom high dose biotin resolved his previously severe autism.

In the case of Fragile-X, there seem to be potential game changers galore.  The latest is plugging the leaky membrane in mitochondria that is allowing ATP to leak out, using a research drug dexpramipexole, or potentially the related and already approved variant Mirapex ER (pramipexole).  Mirapex is used to treat the symptoms of Parkinson Disease and Restless Legs Syndrome. 

If our occasional reader and bio-statistician Knut Wittkowski is correct, Mefenamic Acid (the NSAID Ponstan) could be a real game changer, if taken around 2-3 years of age.  He suggests this will block the progression to severe non-verbal autism. Knut has been upsetting YouTube with some of his interviews about Covid-19 and his deal with Q-Biomed to develop Mefenamic Acid fell through. You can buy Ponstan very cheaply, outside of the US, even as a pediatric syrup.

Hopefully, Dr Naviaux's Suramin will be a game changer for some.  More of that in the coming post on leaky ATP.

Conclusion

I am told where we live that Monty’s autism is “fixed”, or by one autism Grandad we know, “he’s 80% fixed”.

If you started life with (really) severe autism, even 80% fixed means you are still pretty autistic, much more so than Elon and Greta, but far less so than the now adult “children” over at the National Council for Severe Autism, who have really severe autism and often had a very early plateau in development.

Monty has finished his year-end exams.  Overall, the grades of his NT classmates are pretty terrible, maybe due to Covid disruptions.  I told Monty’s assistant that if he can come somewhere in the middle, without her doing the tests for him or having extra time, that is a great result, regardless of the grade itself.  In all his subjects he comes in the middle. In the English educational system, Monty is now a C student, maybe even with the odd B or D; so not something to boast about.  What really is amazing  is this person could not figure out  9 – 2 = 7,  at the age of 9 years old, prior to starting bumetanide and his Polypill therapy.  Now he is nearly 18 years old.

If you find that your young child is a genuine bumetanide responder, but later struggle to source it, take a close look at what untreated severe autism looks like by adulthood.  Then you may choose to redouble your efforts to get hold of your game changer. Some readers are getting it from Egypt, Pakistan, Nigeria, China, Austria and many from Mexico and Spain.  In Brazil you can buy it only in a compounding pharmacy. The lucky ones get it at their local pharmacy, which is what should be possible for everyone and one day that might even happen.

There are countless fine-tuning therapies that may be potentially effective in a particular person.  They are certainly worth having; you just have to look at what is available and cost effective.

There will soon be a post about leaky ATP in Fragile X and autism.

Two readers have highlighted the research suggesting that Betaine might have a similar effect to Bumetanide.  It does not block the NKCC1 transporter, but it may reduce the mRNA that produces them, so the net effect may potentially be similar.  At much lower doses, Betaine is a common autism supplement.  This will be covered in the next post.

 

Update on Roflumilast/Daxas as a PDE4 inhibitor for Autism

 

There is already quite a lot in this blog about using a PDE (Phosphodiesterase) inhibitor to potentially treat autism.

Readers might have seen the recent article below, in which a PDE-4D inhibitor raised cognition in adults with Fragile-X.

Drug boosts cognition in men with fragile X syndrome 

The study drug, BPN14770, is developed by Tetra Therapeutics, a clinical-stage biotechnology company in Grand Rapids, Michigan. It blocks the activity of phosphodiesterase-4D, an enzyme in the brain that degrades cyclic AMP. In a mouse model of fragile X, BPN14770 increased cyclic AMP and eased several fragile-X-related traits.

 

For the new work, 30 men with fragile X participated in a 24-week double-blind crossover study of the drug. The researchers randomly assigned each man to one of two treatment sequences: 12 weeks on the drug followed by 12 weeks on a placebo, or 12 weeks of placebo crossing over to 12 weeks on the drug. Researchers assessed all of the participants at the start of the study and during week 6 and week 12 of each trial sequence. They also asked parents and caregivers to rate changes in the men’s language, daily function and anxiety.

The treatment produced “significant improvement in the language and daily function measures that the families were rating, in conjunction with improvement on this objective test [NIH Toolbox] that’s very hard to have a placebo effect on,” says Elizabeth Berry-Kravis, professor of child neurology at Rush University Medical Center in Chicago, Illinois, who led the study.

 

Later on in the post is the science, which it does help to read. if you want apply it.

The research drug BPN14770 used in the Fragile-X trial is not something you can buy at the pharmacy, but there are PDE inhibitors available today.

I have written a post recently about the use of Pentoxifylline, which is a very cheap drug that is not selective, if affects many types of PDE not just PDE-4D. 

Pentoxifylline – Clearly an Effective add-on Autism Therapy for some

 

Today I am looking at Roflumilast/Daxas which mainly affects PDE-4.  There are 4 sub-types (isoforms) A, B, C and D.  Drugs that affect all these sub-types are called PDE4 pan inhibitors and they usually cannot be used in humans. due to severe nausea.

Roflumilast/Daxas is used to treat COPD/severe asthma at a dose just on the limit, where it begins to be effective and inhibit PDE in the lungs but before the nausea makes it unusable. There is research to make an inhaled version, which would make a lot of sense.

We are interested in PDE4 in the brain, not the lungs.  The effect of Roflumilast on PDE4 is unusual in that it is very dose dependent; too little and there is no effect, too much and there is no effect.  So, the amount of Roflumilast and its metabolites in your blood stream need to be within a tight range.

The median plasma half lives of Roflumilast and its N-oxide metabolite are approximately 17 and 30 hours, respectively.

This means if you give the same dose every day, the level of the metabolites will reach a steady state only after about 5 days.

As mentioned in an early post, roflumilast is not soluble in water, but it is in alcohol.  This means you can make a tincture, just like they do with bee propolis.  In fact, I am using an old propolis bottle, the type with a screw-on pipette.

We know from the research that in healthy adults a dose of 100mcg may be cognitive enhancing.

My target dose was 80mcg, but I wanted to be able to easily vary it.

Take an old propolis bottle and clean it with alcohol/ethanol/vodka.

In a small glass, dissolve 5 tablets (5 x 500mcg Daxas) in 15ml of vodka.  The tablets slowly dissolve; mix well and then use the pipette to transfer the fluid to the bottle and also figure out where on the pipette equates to 0.5ml. When I recently did this it took me 31 squirts, so by eye I was giving on average 83 mcg.

When I first started there was one day of dramatically increased speech, which I could not reproduce.  The first day of Pentoxifylline also had this effect. Pentoxifylline has a very short half-life.

Since at school Monty is having his year-end exams, I decided to focus on cognition.  I think my original dose was too high, more like 100 mcg.  Giving a little extra is something you have to resist.

Being a bit stingy (ungenerous) with the pipette, is what you have to be.

At close to 80 mcg a day, I am getting feedback from school that cognition is great.

Exams started and Monty is doing really well.  They are 90-minute exams and the fact that he is even there is amazing to me; that is down to 8 years of Bumetanide.

It looks like 80 mcg of Roflumilast does give an extra boost to cognition in a 60 kg boy.

Is it worth it?

One pack of 30 x 500mcg Roflumilast/Daxas tablets costs about EUR 40 (about 50 USD) in Europe, but at the 80 mcg daily dose it will last 6 months.

Monty has had been no side effects (nausea, GI etc), but this is very specific to the person. I myself did get GI side effects from 100 mcg.

   

Science that supports the use of a PDE4 inhibitor

There are many different types of PDE (Phosphodiesterase) and there has been a lot of research looking at their relevance to a wide range of neurological conditions.

The table below gives a useful summary, by disorder.

 

Neurodevelopmental disorders are highlighted in red. AD Alzheimer disease; ASD autism spectrum disorder; BP bipolar disorder; DS down syndrome; HD Huntington disease; ID intellectual disability; FXS fragile X syndrome; MDD major depression disorder, RTT Rett syndrome, SCZ schizophrenia.

 

This table is from an excellent paper published earlier this year.

 

Role of phosphodiesterases in the pathophysiology of neurodevelopmental disorders

Phosphodiesterases (PDEs) are enzymes involved in the homeostasis of both cAMP and cGMP. They are members of a family of proteins that includes 11 subfamilies with different substrate specificities. Their main function is to catalyze the hydrolysis of cAMP, cGMP, or both. cAMP and cGMP are two key second messengers that modulate a wide array of intracellular processes and neurobehavioral functions, including memory and cognition. Even if these enzymes are present in all tissues, we focused on those PDEs that are expressed in the brain. We took into consideration genetic variants in patients affected by neurodevelopmental disorders, phenotypes of animal models, and pharmacological effects of PDE inhibitors, a class of drugs in rapid evolution and increasing application to brain disorders. Collectively, these data indicate the potential of PDE modulators to treat neurodevelopmental diseases characterized by learning and memory impairment, alteration of behaviors associated with depression, and deficits in social interaction. Indeed, clinical trials are in progress to treat patients with Alzheimer’s disease, schizophrenia, depression, and autism spectrum disorders. Among the most recent results, the application of some PDE inhibitors (PDE2A, PDE3, PDE4/4D, and PDE10A) to treat neurodevelopmental diseases, including autism spectrum disorders and intellectual disability, is a significant advance, since no specific therapies are available for these disorders that have a large prevalence. In addition, to highlight the role of several PDEs in normal and pathological neurodevelopment, we focused here on the deregulation of cAMP and/or cGMP in Down Syndrome, Fragile X Syndrome, Rett Syndrome, and intellectual disability associated with the CC2D1A gene.

  

It looks like idiopathic autism has the least research, but there is an interesting old paper.

  

Expression of Phosphodiesterase 4 is altered in brain of subjects with autism

 

The cyclic adenosine monophosphate-specific phosphodiesterase-4 (PDE4) gene family is the target of several potential therapeutic inhibitors and the PDE4B gene has been associated with schizophrenia and depression. Little, however, is known of any connection between this gene family and autism, with limited effective treatment being available for autism. We measured the expression of PDE4A and PDE4B by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting in Brodmann's area 40 (BA40, parietal cortex), BA9 (superior frontal cortex), and cerebellum from subjects with autism and matched controls. We observed a lower expression of PDE4A5, PDE4B1, PDE4B3, PDE4B4, and PDE4B2 in the cerebella of subjects with autism when compared with matched controls. In BA9, we observed the opposite: a higher expression of PDE4AX, PDE4A1, and PDE4B2 in subjects with autism. No changes were observed in BA40. Our results demonstrate altered expressions of the PDE4A and PDE4B proteins in the brains of subjects with autism and might provide new therapeutic avenues for the treatment of this debilitating disorder.

  

Conclusion

It looks like Roflumilast/Daxas should join Pentoxifylline on the to-trial list for people with autism.

In my opinion the actions of Pentoxifylline and Roflumilast/Daxas are sufficiently different that conceivably some people might benefit from taking both.

I cannot see why someone with Fragile X should wait another decade for BPN14770 to maybe get commercialized.

There are PDE4 inhibitors in the pipeline for Alzheimer’s.  In my opinion the focus should be more on prevention.  By the time people get diagnosed with Alzheimer’s, it is too late to reverse it.

 

 

 

Vasopressin, Oxytocin, the Lateral Septum, Aggression and Social Bonding, Autism gene NLGN3 and MNK inhibitors for reversing Fragile-X and likely more Autism

 

The Lateral Septum, in green, turns the volume

 up or down in aggression

Today’s post started by me checking for anything new in the research about the hormone Vasopressin and autism. I was surprised by just how much research continues to be published on the subject – no smoke without fire, perhaps.

We also get another insight into how aggressive raging develops in the brain; we even have a photo.

A novel therapy for Fragile-X is also thrown into the mix, due to a link to oxytocin.

So, what is cooking in the research?

The first thing to note is that you really do have to look at both Oxytocin and Vasopressin, because these two hormones are very closely related.

We have previously looked at the autism gene NLGN3, this gene encodes the cute sounding neuroligin-3.

 

https://epiphanyasd.blogspot.com/search/label/neuroglin

 

The reason people with Fragile-X have autism is because they lack the protein FMRP (Fragile X mental retardation protein).

In healthy neurons, FMRP modulates the local translation of numerous synaptic proteins. Synthesis of these proteins is required for the maintenance and regulation of long-lasting changes in synaptic strength. In this role as a translational inhibitor, FMRP exerts profound effects on synaptic plasticity.

When you look at the interactions of the FMRP protein you can find ways to compensate for this deficiency.  This is nicely illustrated in the graphic below. You just need to find another way to influence elF4E and elF4G.

Some people have told me they find these charts a bit overwhelming, but they precisely show what is going on.  You just have to look up all the terms, you do not know.  In the chart below there is NF1 autism, there is PTEN autism, problems with Ras are called RASopathies and cause MR/ID plus autism. We have at least one reader with TSC (Tuberous sclerosis) type autism. We have readers whose kids lack FMRP, because they have Fragile-X syndrome. 

Today we see that an inhibitor of MnK (in yellow in the chart below) is another via option to treat Fragile-X.

Beyond Fragile-X, we can see that numerous other upstream dysfunctions in the chart can result in miss-expression of neuroligins (NLGNs) in the chart below and then result in autism.

 

 One of the papers below goes further and suggests

“This work uncovers an unexpected convergence between the genetic autism risk factor Nlgn3, translational regulation, oxytocinergic signalling, and social novelty responses”

“We propose that pharmacological inhibition of MNKs may provide a new therapeutic strategy for neurodevelopmental conditions with altered translation homeostasis”

“Our work not only highlights a new class of highly-specific, brain-penetrant MNK inhibitors but also expands their application from fragile X syndrome to a non-syndromic model of ASD”

 

Regarding Fragile X 

“Collectively, this work establishes eFT508 (an MNK inhibitor) as a potential means to reverse deficits associated with FXS.”

 

What is the connection to Oxytocin?

A problem with your neuroligins causes an impairment in oxytocin signalling.

 

The role of the Lateral Septum (LS) in both aggression and desirable social behavior 

If you scan through the research on vasopressin and oxytocin you will eventually come across references to the LS.  The LS is a part of your brain called the Lateral Septum.

In the picture below you see a mouse brain and the green part is the Lateral Septum (LS).

 

Source: https://neurosciencenews.com/rage-lateral-septum-3637/ 

“Our research provides what we believe is the first evidence that the lateral septum directly ‘turns the volume up or down’ in aggression in male mice, and it establishes the first ties between this region and the other key brain regions involved in violent behavior”

Both social bonding and offensive aggression involve vasopressin receptors in a part of the brain called the Lateral Septum (LS).  Activity in the Lateral Septum (LS) is regulated by inhibitory GABA, and excitatory glutamate.

There is a notable difference between males and females, at least in rats.  No sex differences were found in extracellular GABA concentrations during social playing; however, glutamate plays a major role in female social playing. When glutamate receptors are blocked in the LS pharmacologically, there is a significant decrease in female social playing, while males had no decrease in playing. This suggests that in the lateral septum, GABA neurotransmission is involved in social play behavior regulation in both sexes, while glutamate neurotransmission is sex-specific, involved in regulation of social play only in females.

 

Aggressive behavior in females 

Neural mechanisms of female aggression: Implications on the oxytocin and vasopressin systems

These models allowed me to investigate the role of the brain oxytocin (OXT) and vasopressin (AVP) systems on aggressive behavior. Both neuropeptides are known to regulate social including aggressive behaviors in males and lactating females.

Taken together this part of my thesis shows that the balance between OXT and AVP release within the LS regulates female aggression in a receptor and region-specific manner via modulating GABAergic neurotransmission.

Overall, this thesis shows that females are able to develop escalated as well as abnormal aggression just like males. In addition, the OXT and the AVP system seem to be main players in regulating aggressive behavior in female Wistar rats, especially, regarding their role in controlling aggression by acting on the LS.

 

The effect of Vasopressin as a therapy

 

Correction of vasopressin deficit in the lateral septum ameliorates social deficits of mouse autism model 

Intellectual and social disabilities are common comorbidities in adolescents and adults with MAGE family member L2 (MAGEL2) gene deficiency characterizing the Prader-Willi and Schaaf-Yang neurodevelopmental syndromes. The cellular and molecular mechanisms underlying the risk for autism in these syndromes are not understood. We asked whether vasopressin functions are altered by MAGEL2 deficiency and whether a treatment with vasopressin could alleviate the disabilities of social behavior. We used Magel2-knockout mice (adult males) combined with optogenetic or pharmacological tools to characterize disease modifications in the vasopressinergic brain system and monitor its impact on neurophysiological and behavioral functions. We found that the activation of vasopressin neurons and projections in the lateral septum were inappropriate for performing a social habituation/discrimination task. Mechanistically, the lack of vasopressin impeded the deactivation of somatostatin neurons in the lateral septum, which predicted social discrimination deficits. Correction of vasopressin septal content by administration or optogenetic stimulation of projecting axons suppressed the activity of somatostatin neurons and ameliorated social behavior. This preclinical study identified vasopressin in the lateral septum as a key factor in the pathophysiology of Magel2-related neurodevelopmental syndromes.

 

In humans, intranasal administration of AVP increased activity in the LS and reciprocated social collaboration (47). Intranasal OXT administration enhances the suppression of oscillatory activity (8–25 Hz) during execution and observation of social actions (48). Altogether, OXT- and AVP-dependent modulation of neural activity in response to social stimuli directly affect EEG activity, which may have a predictive value for the impact of such treatment in ASD-associated disorders. Furthermore, an imbalance between inhibition and excitation is associated with ASD, and AVP treatment could reset the balance by altering the functions of SST neurons (49).

  

Predicting Autism measuring Neonatal CSF vasopressin concentration 

We have yet another predictor of future autism.

Neonatal CSF vasopressin concentration predicts later medical record diagnoses of autism spectrum disorder

The Russian paper below is very thorough. At least in the case of autism, I do not agree with the therapeutic implications.  The paper suggests Oxytocin agonists (like oxytocin itself) and Vasopressin antagonists.

I propose Oxytocin agonists and Vasopressin agonists, as a practical solution today.  It is not a perfect solution, but totally doable today.

  

The role of oxytocin and vasopressin dysfunction in cognitive impairment and mental disorders 

Oxytocin (OXT) and arginine-vasopressin (AVP) are structurally homologous peptide hormones synthesized in the hypothalamus. Nowadays, the role of OXT and AVP in the regulation of social behaviour and emotions is generally known. However, recent researches indicate that peptides also participate in cognitive functioning. This review presents the evidence that the OXT/AVP systems are involved in the formation of social, working, spatial and episodic memory, mediated by such brain structures as the hippocampal CA2 and CA3 regions, amygdala and prefrontal cortex. Some data have demonstrated that the OXT receptor's polymorphisms are associated with impaired memory in humans, and OXT knockout in mice is connected with memory deficit. Additionally, OXT and AVP are involved in mental disorders' progression. Stress-induced imbalance of the OXT/AVP systems leads to an increased risk of various mental disorders, including depression, schizophrenia, and autism. At the same time, cognitive deficits are observed in stress and mental disorders, and perhaps peptide hormones play a part in this. The final part of the review describes possible therapeutic strategies for the use of OXT and AVP for treatment of various mental disorders.

 

4.4. Autism

Autism spectrum disorder (ASD) is a group of disorders that are characterized by early disturbances of social communication and limited, repetitive behaviour. Individuals with autism have impaired social cognition and social perception, executive dysfunction, and atypical perceptual and information processing. Additionally, they exhibit atypical neural development at the systems level . Autism is characterized by a disturbance of social interaction first of all, but it is also characterized by cognitive dysfunctions, including working memory impairment. The OXT/AVP system plays a role in such deficits. In male mice with a mutation in the Magel2 gene, social behaviour and cognitive functions are disrupted in adulthood, which makes this model similar to ASD. The lack of Magel2 causes a change in the OXT system. Subcutaneous administration of OXT to mice with this mutation during the first week of life suffices to restore normal social behaviour and learning abilities in adult mice. Exogenous OXT stimulates the release of endogenous OXT and inhibits the accumulation of intermediate forms of OXT (this is observed in OXT neurons in mice with the Magel2 mutation). This was revealed by neuroimaging methods. Human ASD is associated with altered face processing and decreased activity in brain areas involved in this process. OXT enhances the importance of social stimulus in ASD, and probably can stimulate face processing and eye contact in people with ASD. Genetic polymorphisms of the OXT and AVP receptor genes are associated with ASD. Additionally, this review revealed a link between social cognition disorders in autism and some SNPs in the OXTR and V1a receptor genes. The most significant associations between SNPs in OXTR and social cognition were found for rs2254298, rs53576 and rs7632287. SNP rs2254298 has been associated with a diagnosis of ASD. SNP in the V1a receptor gene, rs7294536, is closely associated with a deficit in social interactions. In addition, OXTR rs237887 polymorphism affects facial recognition memory in families with autistic children.

 

 

 

 

Fig 1. The role of oxytocin and vasopressin systems in the pathogenesis of mental disorders. Stress activates the HPA axis and rises in plasma glucocorticoid levels, which leads to social through the cortisol release. HPA axis activation increases the risk of development of psychopathologies. OXT and AVP regulate emotional behaviours, multiple aspects of social behaviour and cognitive functions. Negative environment, including stress factor, causes an imbalance of the OXT/AVP system, which also leads to psychopathological behaviour: aggression, social impairment, anxiety, emotional and cognitive disorders. At the same time, the OXT/AVP system forms a reaction to stress oppositely. OXT inhibits the HPA axis stress induced activity (anxiolytic effect). AVP activates the HPA axis (anxiogenic effect). OXT and AVP can be used as the treatment of mental diseases associated with social and cognitive dysfunctions. OXT – oxytocin; AVP – arginine-vasopressin; iOXT – intranasal oxytocin; iAVP – intranasal arginine-vasopressin; ACTH - adrenocorticotropic hormone; CRH – corticotropin releasing hormone; HPA axis - hypothalamic-pituitary-adrenal axis.

 

 

5. OXT and AVP systems in mental disorder treatments in recent years, interest in the usage of OXT as the treatment of various psychiatric diseases is growing. OXT and AVP systems that exist in balance produce the contrary effect on emotional behaviour. Positive social stimuli and/or psychopharmacotherapy can shift this balance towards OXT and can help to stimulate emotional behaviour and restore mental health through this shifting. OXT produces an effect on several neurobiological systems, including the HPA axis, limbic system, neurotransmitters, and immune processes related to stress disorders. The exact effects of iOXT still remain unclear; nevertheless, it is known that iOXT action depends on individual sensitivity. Data from functional magnetic resonance imaging demonstrated that iOXT induces temporary activation of some cortex areas and prolonged activation of hippocampus and forebrain areas. These structures are characterized by a high density of OXT receptors. At the same time, iAVP causes stable deactivation in the parietal cortex, thalamus, and mesolimbic pathway. Importantly, the intravenous administration of OXT and AVP does not repeat activation patterns caused by intranasal administration of OXT and AVP. Nevertheless, it is possible that a small amount of OXT which crosses the blood-brain barrier may lead to an additional central OXT release since OXT is able to bind to brain OXT ergic neurons and cause its own release. Generally, OXT doses administered in studies vary from 15 IU to more than 7000 IU. As the table indicates, the results of these studies are very different. The most frequently used dose is 24 IU. Many studies are focused on the capability of OXT in the treatment of depressive disorders. It was demonstrated that iOXT reduces the time of concentration on aggressive facial expressions and increases the time of concentration on happy faces in men and women with chronic depression. Therefore, iOXT regulates emotion recognition in depression. iOXT can be used in combination with antidepressants, enhancing antidepressant efficiency. iOXT administration positively affects mother-child relationship in mothers with postpartum depression (PPD). iOXT activates the protective behaviour of mothers with PPD towards their children. Similar results were found in animal experiments. In rats, iOXT reduced the depressive-like behaviour in adult animals subjected to early maternal separation. Moreover, the research of specific neurogenesis markers Ki67 and BrdU demonstrated that iOXT promotes hippocampal neurogenesis, which is impaired in depressed rats. Many studies investigate the therapeutic properties of iOXT and iAVP for the treatment of schizophrenia and autism. It is known that schizophrenia disturbs social behaviour; and cognitive function. iOXT has the potential for usage as a therapeutic tool to restore impaired functions during schizophrenia. Some data suggest that iOXT reduces the negative symptoms of schizophrenia, improves working memory, verbal memory and cognitive function, and also improves social function in patients with schizophrenia and schizoaffective disorder. Although many studies indicate a positive effect of iOXT on cognitive function in people with schizophrenia, the neuropeptide has a very selective action on behaviour. The exact mechanism of iOXT action is also indefinite; therefore, its therapeutic potential requires further research. Eventually, iOXT can be used as an additional therapeutic agent in traditional schizophrenia treatment. iOXT can also be applied to ASD treatment. It was found that iOXT improves social abilities in children and emotionality in adult men with ASD. Moreover, the improvement of emotional state was observed in adults after an 8 IU dose, but not after 24 IU. The study of iOXT's therapeutic properties was also carried out using a mouse valproate autism model. iOXT improved social behaviour in that model, and reduced anxiety, depressive-like behaviour, and repetitive behaviour. iOXT has some positive effects in the ASD treatment. Despite this, studies of the potential therapeutic usage of iOXT are still at an early stage, and doctors have insufficient data to prescribe iOXT to patients. A few data indicate the therapeutic possibilities of AVP compared to OXT. It is known that iAVP was used in the treatment of the first episode of schizophrenia, in addition to the traditional benzodiazepine treatment. Cognitive functions (namely the memorization process, long-term and short-term memory) improved in patients. iAVP treatment ameliorated social ability in children with ASD. Additionally, iAVP treatment reduced anxiety and repetitive behaviors in these children. These data indicate the necessity of further investigation of AVP's treatment potential.

 

 

Rescue of oxytocin response and social behaviour in a mouse model of autism

A fundamental challenge in developing treatments for autism spectrum disorders is the heterogeneity of the condition. More than one hundred genetic mutations confer high risk for autism, with each individual mutation accounting for only a small fraction of cases^1-3. Subsets of risk genes can be grouped into functionally related pathways, most prominently those involving synaptic proteins, translational regulation, and chromatin modifications. To attempt to minimize this genetic complexity, recent therapeutic strategies have focused on the neuropeptides oxytocin and vasopressin^4-6, which regulate aspects of social behaviour in mammals⁷. However, it is unclear whether genetic risk factors predispose individuals to autism as a result of modifications to oxytocinergic signalling. Here we report that an autism-associated mutation in the synaptic adhesion molecule Nlgn3 results in impaired oxytocin signalling in dopaminergic neurons and in altered behavioural responses to social novelty tests in mice. Notably, loss of Nlgn3 is accompanied by a disruption of translation homeostasis in the ventral tegmental area. Treatment of Nlgn3-knockout mice with a new, highly specific, brain-penetrant inhibitor of MAP kinase-interacting kinases resets the translation of mRNA and restores oxytocin signalling and social novelty responses. Thus, this work identifies a convergence between the genetic autism risk factor Nlgn3, regulation of translation, and oxytocinergic signalling. Focusing on such common core plasticity elements might provide a pragmatic approach to overcoming the heterogeneity of autism. Ultimately, this would enable mechanism-based stratification of patient populations to increase the success of therapeutic interventions. 

Social recognition and communication are crucial elements in the establishment and maintenance of social relationships. Oxytocin and vasopressin are two evolutionarily conserved neuropeptides with important functions in the control of social behaviours, in particular pair-bonding and social recognition7,8 . In humans, genetic variation of the oxytocin receptor (OXTR) gene is linked to individual differences in social behaviour9 . Consequently, signalling modulators and biomarkers for the oxytocin or vasopressin system are being explored for conditions with altered social interactions such as autism spectrum disorders (ASDs)5,6 . In mice, mutation of the genes encoding oxytocin or its receptor results in a loss of social recognition and social reward signalling10–14. Mutation of Cntnap2, a gene linked to ASD in humans, resulted in reduced levels of oxytocin in mice, and the addition of oxytocin improved social behaviour in this model15. However, the vast majority of genetic risk factors for autism have no known links to oxytocinergic signalling. 

Thus, modification of translation homeostasis in Nlgn3KO mice by MNK inhibition restores oxytocin responses and social novelty responses. This work uncovers an unexpected convergence between the genetic autism risk factor Nlgn3, translational regulation, oxytocinergic signalling, and social novelty responses. Although loss of Nlgn3 impairs oxytocin responses in VTA DA neurons, the behavioural phenotype does not fully phenocopy genetic loss of oxytocin. Oxytocin knockout mice exhibit impaired habituation in the social recognition task10, whereas Nlgn3KO mice habituate normally but exhibit a selective deficit in the response to a novel conspecific. This is probably due to differential roles of Nlgn3 and oxytocin across several neural circuits and over development. Moreover, Nlgn3 loss-of-function also affects signalling through additional GPCRs23. We propose that pharmacological inhibition of MNKs may provide a new therapeutic strategy for neurodevelopmental conditions with altered translation homeostasis. Notably, MNK loss-of-function appears to be overall well tolerated. MNK1/2 double-knockout mice are viable46 and several MNK inhibitors are entering clinical trials for cancer therapy47. Previously available MNK inhibitors were greatly limited by specificity and brain penetrance. Our work not only highlights a new class of highly-specific, brain-penetrant MNK inhibitors but also expands their application from fragile X syndrome41 to a non-syndromic model of ASD. The common disruption in translational machinery and phenotypic rescue in two very different genetic models indicate that genetic heterogeneity of ASD might be reduced to a smaller number of cellular core processes. This raises the possibility that pharmacological interventions targeting such core processes may benefit broader subsets of patient populations.

 

A Highly Selective MNK Inhibitor Rescues Deficits Associated with Fragile X Syndrome in Mice 

Fragile X syndrome (FXS) is the most common inherited source of intellectual disability in humans. FXS is caused by mutations that trigger epigenetic silencing of the Fmr1 gene. Loss of Fmr1 results in increased activity of the mitogen-activated protein kinase (MAPK) pathway. An important downstream consequence is activation of the mitogen-activated protein kinase interacting protein kinase (MNK). MNK phosphorylates the mRNA cap-binding protein, eukaryotic initiation factor 4E (eIF4E). Excessive phosphorylation of eIF4E has been directly implicated in the cognitive and behavioral deficits associated with FXS. Pharmacological reduction of eIF4E phosphorylation is one potential strategy for FXS treatment. We demonstrate that systemic dosing of a highly specific, orally available MNK inhibitor, eFT508, attenuates numerous deficits associated with loss of Fmr1 in mice. eFT508 resolves a range of phenotypic abnormalities associated with FXS including macroorchidism, aberrant spinogenesis, and alterations in synaptic plasticity. Key behavioral deficits related to anxiety, social interaction, obsessive and repetitive activities, and object recognition are ameliorated by eFT508. Collectively, this work establishes eFT508 as a potential means to reverse deficits associated with FXS.

  

Conclusion

I think I have written enough about Oxytocin and Vasopressin.

The research is not entirely consistent regarding Vasopressin, but my assumption is that for my kind of autism I want an Oxytocin Agonist and a Vasopressin Agonist, some people might think it would be a Vasopressin Antagonist.

The good news is that there is significant research in humans, reported in previous posts, to support the use of both Oxytocin Agonist and a Vasopressin Agonist

I also think there will be both short-term, or immediate effects, from both treatments but also potentially different long-term effects from continued therapy, that is indeed suggested by the animal research models.  For example, neurite outgrowth is stimulated by oxytocin.  It is suggested that oxytocin may contribute to the regulation of scaffolding proteins expression.

Is it worth using oxytocin as a therapy to generate some extra hugs? You can argue both ways, but the longer-term benefits of correcting low oxytocin levels may be more profound.

The effects of vasopressin and oxytocin are somewhat overlapping. We know that low levels of vasopressin in spinal fluid are a good marker for autism, so putting a little extra vasopressin in the brain does not seem unreasonable.

As usual with the human body, the effects of oxytocin and vasopressin are different within the brain and in the rest of your body.  Also, the levels of these hormones in your blood are not a good predictor of their levels within the brain.  This is a reoccurring problem.  Because taking a spinal fluid sample is an invasive procedure, it is rarely taking place and then endless time and money is wasted on blood tests that may well send the doctor in the wrong direction, or just no direction.

It is highly likely that increasing Oxytocin and Vasopressin in the brain is going to affect aggressive behaviors, via actions in the Lateral Septum (LS).  Due to the role of GABA potentiating activity in the Lateral Septum (LS) you might expect a possible difference in bumetanide-responders and bumetanide non-responders (because GABA is acting as excitatory).

I would consider Oxytocin and Vasopressin as fine-tuning autistic behavior and you would have to personalize the dosage. In some people it might be a case of either or, rather than both.

Using MNK inhibitors to treat human Fragile-X looks a great idea and hopefully a commercialized therapy could then be trialed in broader autism.