4G and Autism - Glutamine, Glutamate, GABA & GAD

This post is not about your IPad, it’s still about autism.

There are a few important substances that I have not fully addressed yet in this blog; as is often the case in biology, the names do all rather look alike.  A complete understanding of these 4 Gs will definitely help to understand the literature and hopefully separate science from pseudoscience and the voodoo.

We know for a fact that in autism some strange things are going on here, but it remains to be proved exactly what is going on, and whether all types of autism are similarly affected.  So it may be premature to visit the supplement shop.

 

The 4 Gs

Glutamine, like Creatine, is one of those chemicals that is widely used by body builders and sometimes given to children with autism.  It is an amino acid.

Glutamine is a precursor chemical to Glutamate.  Glutamate is a major excitatory neurotransmitter in the brain.

Glutamate is a precursor chemical to GABA, another very important neurotransmitter.

Glutamate is converted to GABA by the neuronal enzyme glutamate decarboxylase (GAD).

Glutamate is synthesized from glutamine via glutaminase, but after release in the synapse, glutamate is converted back into glutamine in glial cells, by glutamine synthetase.

 

Some Facts

Glutamine

Glutamine is known to help heal injuries and recover from abdominal surgery.  It was thought that this would extend to helping maintain the gut barrier, which is sometimes implicated in autism.  DAN type doctors use glutamine to “heal the gut”; however, when trials were made in Crohn’s disease, an inflammatory bowel disease similar to the type sometimes implicated in autism, supplementing with glutamine had no effect.
 

Glutamate

Glutamine + H2O

→ Glu + NH3

 

Glu is actually glutamic acid, the salts and esters of glutamic acid are called glutamates.  Often the literature mixes the terms glutamate and glutamic acid.

NH₃ is ammonia, which is also important and plays a role in some people’s autism theories.

Excessive glumate release is implicated in autism.  Glutamic acid is implicated in epilepsy, which is highly comorbid with autism.

Glutamate decarboxylase (GAD) is an enzyme that catalyzes the conversion  of glutamate  to GABA and CO₂.

HOOC-CH₂-CH₂-CH(NH₂)-COOH → CO₂ + HOOC-CH₂-CH₂-CH₂NH₂

Where HOOC-CH₂-CH₂-CH₂NH₂  is GABA (Gamma-Aminobutyric acid)

 
GABA

GABA is another amino acid and important neurotransmitter.  It is also known to regulate muscle tone, which is often affected in autism.

GABA works by binding at receptors, this binding causes the opening of ion channels to allow the flow of either negatively charged chloride ions into the cell or positively charged potassium ions out of the cell.

There are two classes of GABA receptor : GABA_A and GABA_B

The drug Baclofen is an agonist for the GABA_B receptors. A version of this drug called Arbaclofen is being developed as a treatment for autism and Fragile X.

Baclofen is a drug to treat spasticity, which is a condition where there can be strange effects on the muscles like spasms, stiffness and tightness.  Some people with ASD have a tendency to clasp their hands and fingers in a strange tight claw-like fashion and indeed some walk with an odd gait.  That would appear to me to be a form of spasticity.  Baclofen was stumbled upon by accident as a possible autism drug, where it would treat a form of mental spasticity.

Baclofen also has a long forgotten secondary effect that interested me; it stimulates the production of GH (Growth Hormone).  GH does appear to be implicated in autism along with IGF-1 and its analogues.

An antagonist of the GABA_A receptor, bumetanide, works by blocking the NKCC1 cation-chloride co-transporter, and thus decreases internal chloride concentration in neurons. In turn, this concentration change makes the action of GABA in some people with autism, returning it from excitory to inhibitory, where is should be.

I think it is clear that GABA plays a major role in some types of autism.

Recent Studies

As noted in previous posts, some very practical research comes out of Iran these days.

Increased Glutamate and Homocysteine and Decreased Glutamine Levels in Autism: A Review and Strategies for Future Studies of Amino Acids in Autism

"2.1. Glutamate

Glutamate is a major excitatory neurotransmitter in the brain. The high level of plasma glutamate level especially in children with normal IQ is supposed to be a diagnostic screening test. The increased plasma level in adults with autism is also reported. Higher glutamate level is not limited to plasma, and some studies confirmed its higher level in some brain regions (amygdala-hippocampal regions but not in parietal region) of patients with autism compared to the controls. The increased plasma glutamic acid is not limited to patients with autism, but its level is increased in their siblings and parents. "

"2.2. Glutamine

The low level of plasma glutamine level is suggested as a screening test for detecting autism in children especially those with normal IQ. The decreased level has been reported before in all children with autism."

A very recent study by King's College London looked at the level of glutamate and glutamine in adults with ASD using clever proton magnetic resonance spectroscopy in two brain regions. 

Reduced subcortical glutamate/glutamine in adults with autism spectrum disorders: a [1H]MRS study 

They found reduced levels of the combined signal of glutamate and glutamine in autism versus the control group.  It all sounds very clever until you get to the discussion part, where they say:-

"Hence, it could be that serotonergic abnormalities underlie the differences in Glx we observed—either indirectly via influences on neurodevelopment or through direct action on glutamate metabolism."

This may be the case of over-analyzing certain variables, because the technology exists, even though you can only understand 20% of the problem.  The end result is lots of complicated looking data and analysis that may actually lead nowhere.

A reality check is required.  We have to come back to definitive facts otherwise the research is just generating confusion.

We already know serotonergic abnormalities are present in autism.  We know that drugs that increase brain serotonin, such as LSD and Prozac, improve autistic behaviours.  So the researchers at Kings College have very likely just measured a consequence of these abnormalities.  As a result, the glutamate/glutamine issue may indeed join the long list of consequences, rather than causes of autism.

 

The fever effect (again)

Another reason for this post is that both Glutamine and Glutamate have been put forward as possible explanations for the fever effect in autism; that is a reduction in autistic behaviour when person is sick, with a high temperature.

The fever effect is so dramatic in some people, that it would be ever so easy to validate a hypothesis.  In doing so, you would open the door to a very useful therapy for many people.

Does infectious fever relieve autistic behavior by releasing glutamine from skeletal muscles as provisional fuel?

 

This paper was published in the Journal Medical Hypotheses, but the full version is not always available free, the first link is to the author’s own site.  It is a very thorough analysis and worth a read, but in the end the author seems to disprove his own hypothesis.

A preliminary version of this paper was sent to several hundred ASD practitioners (DAN Doctors) formerly listed on the ARI site, for feedback. Fourteen replies suggest ASD practitioners commonly give oral glutamine to heal the intestines, from 250 mg to 8 g/day, with few side effects (some hyperactivity) but few notable improvements in behavior.

So now on to the next candidate, glutamate.

The second hypothesis is by Ghanizadeh, the Iranian author of the paper I referred to earlier.

Could fever and neuroinflammation play a role in the neurobiology of autism? A subject worthy of more research.

Abstract

Autism is neuropsychiatric disorder in which a hyperglutamate state may play a role. It is suggested here that fever or hyperthermia may be able to alter glutamate levels in the brain and may therefore be able to impact on the symptoms of autism. More study on this possibility is clearly warranted.

Conclusion

Of the 4 Gs, I am sticking with GABA as the key one, but I will not be buying any GABA supplements, even though they do exist.  Some DAN-type doctors favour Glutamine supplements, even though some well-known “holistic” type doctors like Dr Mercola say specifically not to give it to kids with ASD and ADHD.

I have no doubt that glutamate plays an important role in autism, but as with GABA it is not just a matter of swallowing some.

There is a line to be drawn between science, pseudoscience and pure voodoo. For the time being, you have to find this line yourself.

Autism Clinical Trials, Arbaclofen (STX209), Curemark CM-AT and the Clever Chiropractor

 

In the world of clinical trials for drugs, judging success and failure can be highly subjective.  They try to make it as logical as possible and the method works pretty well for assessing things that you can measure objectively.

Primary and Secondary Endpoints

To quote Pfizer:

A trial endpoint of a clinical trial should fulfill three criteria: (1) be measurable and interpretable, (2) sensitive to the objective of the trial, and (3) clinically relevant. The endpoint can be either clinical or surrogate in nature.

If you are developing a drug to lower cholesterol or to increase survivability after a traumatic brain injury, it is pretty easy to define your endpoints.

When it comes to autism, one of the major hurdles is to define objective measurable endpoints.  As it stands today, none of the assessment tools are really fit for purpose, when Big Pharma is supposed to come along and invest hundreds of millions of dollars in some bright spark’s idea.

Arbaclofen, Seaside Pharma & Roche

The Swiss giant, Roche, recently had just such a problem.  They had partnered with a spinout company from MIT called Seaside Therapeutics.  One of the projects was to complete the trials of a fragile X targeted drug, called Arbaclofen (STX209).  During the 4+ years of trials Seaside had changed the primary endpoint.  Arbaclofen started out as drug to treat one aspect of behaviour, but by the time they got to phase 3  clinical trials this had been changed to lethargy and social withdrawal scores from the Autism Behavior Checklist (ABC).

Quite logically, Roche assessed the result of the stage 3 trial against its primary endpoint.  Based on the total cohort in the trial, Roche determined the drug to be a failure and pulled the plug on financing the drug further.

Open Label Extension Study of STX209 (Arbaclofen) in Autism Spectrum Disorders

The owner and developer of the drug, Seaside, even though they have recently raised $90 million, said they could no longer continue to fund the trial and all those kids in the trial would have to be weaned of Arbaclofen ASAP.

It turns out that among the families involved in the trial there were many reports of wonderful improvements on Arbaclofen.  They even formed a group to lobby for a continuation of the trial.  There website is interesting.

They wrote to big boss of Roche in Basel. 

And he wrote back to them.

It now appears that Seaside has had a rethink and will try again with a new trial with a new primary endpoint (mark 3).

Background on Arbaclofen

Some of the first studies of Arbaclofen were conducted in patients with Fragile X syndrome, a genetic condition caused by a change in a gene called FMR1, which normally is needed to make the brain grow properly. Fragile X is the most common form of inherited intellectual disability in boys and can be a cause of autism or related disorders. In those Phase 2 trials, Arbaclofen was shown to decrease social withdrawal and improve adaptive social function.

A  Phase 2a study conducted at 8 sites and involving 32 children showed significant positive behavioral outcomes, including improved scores on the Aberrant Behavior Checklist-Irritability Score (ABC-I) and on the ABC-Social Withdrawal Scale. The most common adverse events were agitation, irritability, fatigue, psychomotor hyperactivity, insomnia and diarrhea. Most resolved without dose changes, but one serious adverse effect did occur during down-titration of the medication.

In July 2011, Seaside Therapeutics, announced that 25 sites across the nation will be involved in a new clinical trial to involve approximately 150 ASD patients between the ages of 5 and 21.

STX209 is an orally-administered GABA-B agonist; the drug acts by stimulating the release of GABA, a neurotransmitter in the central nervous system. GABA inhibits the release of glutamate, an excitatory neurotransmitter, for which an overabundance negatively affects the ability of neurons to communicate with each other.

The GABA "A" receptor, is a chloride channel, while STX209 targets the GABA "B" receptor, which is a G-protein coupled receptor and regulates a different set of molecules from GABA "A".

The original basis for starting this blog was my success with bumetanide, which is affecting the GABA “A” receptor.  In the brain, bumetanide blocks the NKCC1 cation-chloride co-transporter and thus decreases internal chloride concentration in neurons.

Medicine as an art and a science

Mark Bear is a neuroscientist at MIT and he was the co-founder of Seaside Therapeutics.  He is clearly a very brainy guy.

There is a derivative of his Arbaclofen called Arbaclofen Placarbil.  I found it interesting that this substance was also being trialed as a therapy for Multiple Sclerosis and GERD.  GERD is the medical term for heartburn/indigestion.

Incidentally, Arbaclofen Placarbil failed both trials.

Now to the Clever Chiropractor and her Pancreatic Enzymes

People outside the US will find it very strange that in the US chiropractors and osteopaths have the same right to prescribe drugs as conventional medical doctors. 

Outside of the US, if you want to be a doctor you have to apply to medical school and in most countries the competition is very tough. There is no plan B if your exam grades slip.  In the US it is different, if your grades and resources are not taking you to the Harvard, you can opt to become an osteopathic physician or a chiropractic physician.

Rather than Harvard or MIT, Joan Fallon trained as a chiropractor at Palmer University.

Not surprisingly the scientific community is skeptical of her autism treatment, which is linked to pancreatic enzymes.  After all, how can a chiropractor know more than Ivy League neuroscientists?

Peter, on the other hand, thinks that Fallon is actually far more savvy than the very brainy people over at Seaside.  Her therapy may, or may not be effective, but her method of developing it is highly effective.

First she raised $6 million to start her company Curemark, then as trials progressed she very recently she raised another $18 million.

The reason I like what Fallon is doing is that she has figured out which sub-type of autism is helped by her therapy and she has identified a bio-marker for that subgroup.

Hallelujah, a street-smart autism researcher !

If you want to enroll in a clinical trial for Curemark’s CM-AT, first they will screen out the 50% that do not have the biomarker.  Fallon is making sure that her clinical trial results look as good as possible, by only including those subjects most likely to benefit.  This may sound like common sense, but in autism research this is a revolution.

CM-AT therapy and the biomarker

The reason the autism world are skeptical of Fallon, is that she is going on about Secretin and pancreatic enzymes.

Many years ago parents thought that Secretin was going to be the wonder cure for autism; it turned out not to be.  By reading her patents, it is clear that Fallon has some faith in the role of secretin, in addition to enzymes produced in the pancreas.

What impressed me was how she has screened the kids allowed into her clinical trials.

A Trial of CM-AT in Children With Autism 

Eligibility

·         Inclusion criteria:

o    Child is 3-8 years old

o    Child has a diagnosis of autistic disorder

o    Child must have a low fecal chymotrypsin level (we will measure)

·         Exclusion criteria:

o    Child must have no dietary restrictions (other than for a nut allergy)

o    Child may not have an allergy to pork products

o    Child may not have a history of severe head trauma or stroke

o    Child may not have had a seizure within the past year

o    Child may not be diagnosed with: HIV, cerebral palsy, endocrine disorder or pancreatic disease

o    Child may not be taking any enzyme product, amino acids, secretin product or stimulant medication currently 

“Low fecal chymotrypsin level” is a standard lab test available all around the world.  Over the years Fallon has found that it is a biomarker of the kids who benefit from her patented mix of enzymes sprinkled on their meals.

You actually can buy a very similar product called Creon, or Kreon, depending on which country you live in.  The reason why you cannot be in the trial if you have a pork allergy, is that they use the pancreas of dead pigs to make the enzymes.  This is bad news if you are Jewish, Muslim, a Seventh Day Adventist, or indeed the pig.

The active ingredient in Creon is Pancreatin. Pancreatin contains the pancreatic enzymes lipase, amylase and protease. These assist the digestion of fat, carbohydrates and proteins.

Update on trials of CM-AT

Here is a link to the always-helpful Simons Foundation, with the expected skeptical comments from experts:-

 https://sfari.org/news-and-opinion/news/2010/first-drug-for-autism-enters-final-stage-of-testing

Now Curemark have finished there phase 3 trial, and guess what? It met both primary and secondary endpoints and has been “fast-tracked” by the FDA.

Congratulations Joan !!!

One of the secrets of her success was to have the good sense to enroll herself in a course on clinical investigation run by Harvard/Massachusetts general hospital.

 

Curemark Begins NDA Submission for CM-AT Autism Treatment

CM-AT had previously been granted Fast Track status by the FDA, a designation given to drug candidates that treat serious or life-threatening conditions and demonstrate the potential to address unmet medical needs. The rolling submission process allows companies with a Fast Track designation to submit the NDA in sections to the FDA as they are completed.

“Initiating our ‘rolling NDA’ submission is a major step in the registration process for CM-AT,” said Dr. Joan Fallon, Curemark founder and CEO. “We have an extraordinary opportunity to help many children with autism improve the quality of their lives and we will continue to work closely with the FDA to make that happen.”

Curemark previously announced the successful completion of its Phase III multicenter clinical trial of CM-AT for autism. CM-AT met both primary and secondary endpoints in its double-blind, randomized, placebo-controlled study of children with autism at 3 to 8 years of age.



  

Conclusion

I would suggest those researchers who believe that diet can be an effective therapy in sub-types of ASD take good note of Joan Fallon's methods. You might indeed be right, but unless you can prove it, the skeptics will always hold sway.