Modulation of IP3 receptors in Autism – Pancreatitis and Caffeine?

This post stems from our Greek reader Petra's original observations about the combined effects of coffee and bumetanide.

In earlier posts we learned that one likely nexus in autism is the IP3 receptor that releases calcium from a store within each cell.

It turns out that too little/too much activity from IP3 receptors is a feature of a wide range of disease, some of which you may not have heard of, including:-

·      Gillespie syndrome, a genetic condition leading to MR/ID, ataxia and notably part of the iris to be missing

·      Spinocerebellar ataxias, genetic conditions that cause loss of movement control

·      Glioblastoma, an aggressive and “untreatable” brain cancer

·      Alzheimer’s disease

·      Huntington’s disease

·      Pancreatitis, inflammation of the pancreas where your body makes its digestive enzymes and insulin 

For detail, refer to this Japanese paper:- 

IP3 receptor mutations and brain diseases in human and rodents

Of the three types of IP₃Rs, the type 1 receptor (IP₃R1) is dominantly expressed in the brain and is important for brain function. Recent emerging evidence suggests that abnormal Ca²⁺ signals from the IP₃R1 are closely associated with human brain pathology. In this review, we focus on the recent advances in our knowledge of the regulation of IP₃R1 and its functional implication in human brain diseases, as revealed by IP₃R mutation studies and analysis of human disease‐associated genes. 

I suspect that both hyper and hypo-active IP3 receptors will be found in different types of autism. I assume the variant I deal with in my son is more likely to be hyperactive. The research by Gargus suggested “dysregulated IP3R” in autism in 3 single gene autisms; he found depressed Ca²⁺ release through inositol trisphosphate receptors (IP₃Rs) in patient-derived fibroblasts.

Shared functional defect in IP3R-mediated calcium signaling in diverse monogenic autism syndromes

Your body contains a lot of calcium, but almost all of it is in your bones, as calcium phosphate.  Only the residual amount (about 1%) of calcium is present in solution as the ion Ca²⁺. Ca²⁺ plays an important role in many physiological functions.  An excessive elevation of Ca²⁺ inside cells will kill them. Cells must maintain the intracellular Ca²⁺ concentration at the low level of ~10⁻⁷ mol/L, against the much higher extracellular Ca²⁺ concentration (~10⁻³ mol/L).

Cells must be able to rapidly and dynamically change the intracellular Ca²⁺ concentration in response to extracellular stimuli to regulate physiological functions such as cell proliferation, fertilization, immune response, and brain functioning.

To dynamically change the intracellular Ca²⁺ level, cells use two sources of Ca²⁺:

·      Ca²⁺ influx from outside (the extracellular space)

·      Ca²⁺ release from inside (the intracellular Ca²⁺ store, the endoplasmic reticulum – ER)

Many Ca²⁺ handling molecules (Ca²⁺ ion channels, Ca²⁺ pumps, Ca²⁺ sequester proteins) work to maintain the correct balance. The IP3 receptor is a key protein in the regulation of the intracellular Ca²⁺ dynamics, because it  controls the release of intracelluar Ca²⁺.

If IP3R is left open, Ca²⁺ levels inside cells become too high; if it is left shut Ca²⁺ becomes too low.

No medical therapy currently exists to inhibit/block IP3 receptors, but today’s post considers one potential therapy – caffeine. 

Caffeine

Caffeine is a drug, although it is not regulated as one.  At high doses caffeine is toxic, but at non-toxic doses caffeine does have some potent medical effects and it does protect against certain diseases.

It protects against pancreatitis, for example.

It would be very hard to drink yourself to death with coffee. Just like eating numerous bananas does not cause death by having too much potassium in your blood. Supplements have more risks than food. 

Pancreatitis IP3R and Caffeine 

Caffeine protects against experimental acute pancreatitis by inhibition of inositol 1,4,5-trisphosphatereceptor-mediated Ca2+ release 

Significance of this study

What is already known on this subject?

·       Acute pancreatitis is a major health problem without specific drug therapy.

·       Coffee consumption reduces the incidence of acute alcoholic pancreatitis.

·       Caffeine blocks physiological intracellular Ca²⁺ oscillations by inhibition of inositol 1,4,5-trisphosphate receptor-(IP₃R)-mediated signalling.

·       Sustained cytosolic Ca²⁺ overload from abnormal Ca²⁺ signalling is implicated as a critical trigger in the pathogenesis of acute pancreatitis.

What are the new findings?

·       Caffeine and its dimethylxanthine metabolites inhibit IP₃R-mediated, sustained cytosolic Ca²⁺ elevations, loss of mitochondrial membrane potential and necrotic cell death pathway activation in pancreatic acinar cells.

·       Neither specific phosphodiesterase inhibitors nor cyclic adenosine monophosphate and cyclic guanosine monophosphate inhibit sustained Ca²⁺ elevations in pancreatic acinar cells.

·       Serum levels of xanthines after 25 mg/kg caffeine administration are sufficient to inhibit IP₃R-mediated Ca²⁺ overload in experimental acute pancreatitis.

·       Caffeine but not theophylline or paraxanthine administered at 25 mg/kg significantly ameliorated pancreatic injury in experimental acute pancreatitis through IP₃R-mediated signalling inhibition.

How might it impact on clinical practice in the foreseeable future?

·       These findings support an approach of inhibition of Ca²⁺ overload and of its consequences as novel potential therapy for acute pancreatitis.

·       Methylxanthine-based structures are suitable starting points for drug discovery and development to treat acute pancreatitis. 

The Pancreas and Autism

The biomarker proposed by Joan Fallon/Curemark for her autism treatment (CM-AT) is low fecal chymotrypsin level. Chymotrypsin is a digestive enzyme produced in the pancreas and it can be used as a test for early cystic fibrosis. In adults low chymotrypsin indicates a pancreatic disease like pancreatitis.

Many people with autism have GI problems, but there are several distinct sub-groups. Some people have inflammatory bowel disease (IBD) potentially leading to ulcerative colitis, but most do not. Some people with autism have GI dysfunctions that remain undiagnosed, for some it is as if they do not digest food the same way as other people.

If IP3R hyperactivity is a feature of some autism and IP3R hyperactivity is inherent in pancreatitis, is it a surprise that some people with autism do not seem to digest their food properly? Or is it just a coincidence?

Brain Cancer

We did come across glioblastoma in a previous post that looked at off-label therapies for some cancers. In that post we came across an academic from San Diego, who decided to read the research and try and reverse his incurable aggressive brain cancer. This involved driving across the border to Mexico to freely acquire the prescription drugs he used to treat himself.  Two decades later he is still very much alive. 

More Wnt Modulation for Autism and More Inexpensive Potential Cancer Therapies

According to the study below, a hot cup of strong Greek coffee might be a good choice to maintain Professor Williams in good health.

Caffeine-mediated inhibition of calcium release channel inositol 1,4,5-trisphosphate receptor subtype 3 blocks glioblastoma invasion and extends survival.

IP₃Rs are known to be difficult to study especially due to the lack of suitable inhibitors and subtype specific blockers. We found that caffeine paradoxically inhibited IP₃R-mediated Ca²⁺ responses in a subtype 3 specific manner (Figure 5). Using caffeine as a tool to inhibit IP₃R3-mediate Ca²⁺ release, we have demonstrated that inhibiting IP₃R3 effectively reduced the migration, invasion, and survival of glioblastoma cells (Figure 2). The gene silencing of IP₃R3 by shRNA also effectively reduced the caffeine sensitivity of Ca²⁺ signaling and invasiveness in the Matrigel invasion assay (Figure 5). Our results are the first to demonstrate the involvement of IP₃R3 in glioblastoma Ca²⁺ signaling and invasion. Furthermore, we suggest that IP₃R3 can be specifically targeted for therapeutic intervention in glioblastoma patients with minimal influence on normal glial as well as neuronal functions.

Whether caffeine can directly affect the gating of IP₃R3 channels or not is still unknown. However, according to previous studies demonstrating that caffeine can compete with ATP binding to IP₃Rs (21) at millimolar concentrations (20), caffeine could selectively bind to IP₃R3 and affect the gating of IP₃R3. Further work is required to investigate the direct role of caffeine on IP₃R3 gating in comparison to other subtypes of IP₃R.

In summary our study provides IP₃R3 as a novel therapeutic target for glioblastoma treatment. Our study also provides new insights into the detailed molecular mechanism of caffeine action on migration and invasion of glioblastoma. The apparent beneficial effect of caffeine suggested by our study should trigger future investigations of the therapeutic potential for caffeine to treat this deadly disease that otherwise has no cure. 

Conclusion

Caffeine is the most obvious modulator of IP3R in your kitchen or at the local pharmacy.

cAMP plays a complex role in IP3R, PKA is involved so PDE4 should be. Parathyroid hormone (PTH) is also important. PTH is secreted to tell your bones to release Ca²⁺ into the bloodstream, but it has multiple roles. PTH causes the release of IP3 and DAG and hence release of calcium from the store within cells (the ER). PTH release is stimulated when Ca²⁺ is low but also by other things, such as notably by histamine. PTH also is reported to increase the sensitivity of IP3R receptors, so too much PTH would clearly be a bad idea.

Primary Hyperparathyroidism (PHPT) is characterized by hypercalcaemia and elevation of parathyroid hormone.  Children with PHPT may present with non-specific complaints such as behavioural change and deteriorating school performance.  As we know, behavioural change in the form of aggression sometimes occurs in autism, ADHD and various other mood disorders. It may also present as a psychiatric manifestation of an endocrine disorder such as Primary Hyperparathyroidism (PHPT).

It is not surprising that histamine can cause aggression in the same way that Primary Hyperparathyroidism does. Aggression in all psychiatric disorders very likely has a biological cause, you just have to look for it. 

Aggression and Homicidal Thoughts in a Patient with Primary Hyperparathyroidism: A Case Report.

How about checking kids with aggression/SIB for PHPT, or just high levels of calcium (hypercalcaemia). Or perhaps:-

Going Loco? Think histamine, calcium and hyper-parathyroidism, before taking antipsychotics.

Back to caffeine.

In people with hyperactive IP3 receptors, such as those who damaged their pancreas by drinking too much alcohol, caffeine looks a smart therapy. The same would apply to people with autism and hyperactive IP3 receptors. So for those people, drink coffee, preferably Greek coffee (or Turkish coffee, which is the same thing). Some Latin American countries also make potent coffee drinks. Your cup of instant coffee, or chain store coffee is not going to do much.

There are numerous interesting substances in less processed coffee, not just caffeine. The key is to process it as little as possible, as we saw cocoa. In instant coffee only the caffeine is going to have much effect.

Chlorogenic acid, an OAT3 inhibitor, that should enhance bumetanide, is there in coffee.

Coffee contains small amounts of Caffeic acid. What we would really like is Caffeic Acid Phenethyl Ester (CAPE), which is a substance found in some bee propolis. CAPE acts as a PAK1 inhibitor, among other potentially beneficial effects.

Catechin, epicatechin, and surprisingly vanillin are present in coffee.

Roasting coffee makes big changes to its chemical composition and of course to its taste. Green coffee bean extract, used as a supplement for weight loss, is a rich source of chlorogenic acid.

Perhaps someone should do a study on adults with autism using 2 cups of Greek coffee a day.  Alternatively you could just use caffeine pills, with or without coffee bean extract for those interesting flavanols.

Amino Acids Disturbed in Autism? Very Likely

Amino acids in your body are the building blocks for making proteins. There are essential Amino Acids that you must obtain from diet and semi-essential amino acids that in young children are body is still not able to produce and non-essential amino acids that your body can produce. 

There was an earlier post on Amino Acids:- Amino Acids in Autism 

There are also sub-groups, Branch Chained Amino Acids (BCAAs) and aromatic.  The branched chained amino acids (BCAAs) compete with the aromatic amino acids for entry into the brain. Therefore, altering BCAA levels can affect the levels of the neurotransmitters serotonin, dopamine, epinephrine and norepinephrine in the brain. 

Alanine
Arginine (essential)
Asparagine
Aspartic acid
Cysteine
Glutamic acid
Glutamine
Glycine
Histidine (essential) Aromatic
Isoleucine (essential) BCAA
Leucine (essential) BCAA
Lysine (essential)
Methionine (essential)
Phenylalanine (essential)  Aromatic
Proline
Serine
Threonine (essential)
Tryptophan (essential) Aromatic
Tyrosine  Aromatic
Valine (essential)  BCAA 

Taurine is not an amino acid, but often gets treated as if it was one.

Arginine and its derivatives appear to play a critical role in some types of cognitive impairment including Alzheimer's and other forms of dementia.

I am writing new posts about certain individual amino acids that look interesting. Aspartic acid is next and the post looks like getting rather complex, so I decided to highlight an interesting very simplistic study that I stumbled across, that would otherwise get lost in other complex papers.  

I call it simplistic because it compares a control (NT) group with two groups of children with autism, one group has no intervention and the other group is made up of kids with some intervention, of any kind, under the umbrella of digestive/dietary/enzyme/antifungal. The control group was siblings of the children with autism. So three groups in total.

Nonetheless, this Disney science does show something quite surprising. In most cases it looks like any intervention produced results much closer to the reference range than no intervention. The study did not measure whether the intervention had any effect on the severity of autism, or compare the different interventions.

Since I am currently researching Aspartic acid I was drawn to the fact that Aspartic acid was nearly three times higher for the female controls compared with the males.  This I find notable, given the sex difference in autism, which is the biggest clue nature has left us. 

Altered amino acid excretion in children with autism 

A total of 63 subjects were recruited, consisting of 34 autistic children with 31 males and three females aged 5–15 years (mean ± SD, 6.9 ± 2.5 years), and 29 controls with 13 males and 16 females also covering a range of 5–15 years (mean ± SD, 8.9 ± 3.3 years). The controls were derived primarily from siblings of the autistic group, where the sex ratio was more reflective of the general population compared to the sex balance of the autistic population which is recognised as approximately 4:1 (male:female).15 Measures were taken to account for the uneven sex-distribution in the interpretation of the results.

Twenty-two of the autistic children were receiving therapeutic treatments related to digestive function and nutritional uptake. These treatments included antifungal medication, to treat confirmed or suspected Candida infection of the digestive tract, probiotics for maintenance of gut microflora, dietary intervention (gluten- and/or casein-free diet), nutritional supplements, or the hormone secretin; this has been shown to be responsible for regulating pH of the duodenum and is, therefore, pertinent to the functioning of digestive enzymes. On this basis, the autism group was further subdivided into two groups for evaluation of urinary metabolites: treated autistic patients (n = 22; range, 5–15 years; mean, 6.9 ± 2.4 years; 91% male) and untreated autistic patients (n = 12; range, 5–12 years; mean, 7.0 ± 2.5 years; 91% male). To account for any sex-associated differences in urinary output, resulting from the disparity in the sex matching of the autistic and control groups, the control population was first subdivided on the basis of gender.

Two compounds emerged as significantly different on a gender basis for the control group: (i) glucose excretion was of a significantly higher mean concentration for the female control group compared with the males (P <0.05); and (ii) aspartic acid was nearly three times higher for the female controls compared with the males (P < 0.05). No other urinary metabolite concentrations proved to be significantly different between the female and male controls. On this basis, the data from the entire control group were compared with the treated and untreated autistic cohorts.

Plasma amino acids vs urinary amino acids 

There are numerous other studies and they do tend to use a blood test rather than a urine sample. Below is a relatively recent study from Egypt. 

Study of plasma amino acid levels in children with autism: An Egyptian sample

Methods

Twenty autistic children were compared to twenty healthy age and sex matched normal children serving as control, where serum amino acids, urea, ammonia and protein electrophoresis were estimated.

Results

As regards essential amino acid levels, autistic children had significant lower plasma levels of leucine, isoleucine, phenylalanine, methionine and cystine than controls (P < 0.05),while there was no statistical difference in the level of tryptophan, valine, threonine, arginine, lysine and histidine (P > 0.05). In non-essential amino acid levels, phosphoserine was significantly raised in autistic children than in controls (P < 0.05). Autistic children had lower level of hydroxyproline, serine and tyrosine than controls (P < 0.05). On the other hand there was no significant difference in levels of taurin, asparagine, alanine, citrulline, GABA, glycine, glutamic acid, and ornithine (P > 0.05).

There was no significant difference between cases and controls as regards the levels of urea, ammonia, total proteins, albumin and globulins (alpha 1, alpha 2, beta and gamma) (P > 0.05).

Conclusions

Autistic children had lower levels of some plasma amino acids except for glycine and glutamic acids and phosphoserine were increased with normal serum levels of urea, ammonia, total proteins, albumin and globulins (alpha 1, alpha 2, beta and gamma). 

In conclusion, autistic children may have dysregulated amino acids metabolism as all amino acids except for glutamic acid, phosphoserine and glycine are decreased in patients than in control; the raised glutamic acid may suggest involvement of an altered glutamate transporter and is consistent with a biochemical basis for autistic disorders. Also, the lower amounts of essential amino acids are correlated with more severe autism.

Conclusion

The fair conclusion is that both excreted and plasma amino acids look to be disturbed in autism. Does this tell you anything actionable? Should you become obsessed by trying to reach the reference ranges?

The answer depends on who you ask and I guess who is paying.

The derivatives of some amino acids may indeed be disturbed as a protective mechanism in which the body is adapting to specific effects of that person's autism. This was suggested in the research as one explanation of why agmatine, a derivative of arginine, is elevated in schizophrenia.  In other words elevated agmatine is a good thing in that person, it may well be a biomarker for schizophrenia, but possibly a "good" biomarker. 

If normalizing amino acids does improve autism, then expect the CM-AT treatment from Curemark to pass its phase 3 trials and become an FDA approved therapy for autism. Interestingly when I looked into the Curemark patents a long time ago, secretin appeared and it made another appearance earlier in this post. Secretin is now viewed as a false hope for autism treatment and those who still use it are seen as quacks. In trials secretin was shown not to help most people with autism, but regular readers will know that this is different from saying nobody responds. 

Irrespective of what finally happens to CM-AT, it looks like individual amino acids do have a place in some personalized autism therapies. This may, in some cases, be irrespective of the reference ranges, in other words in some cases an abnormally high level of one amino acid may be required to get a specific beneficial therapeutic effect.  Staying within the reference range is clearly the safer option.

Now I am back to my complicated post about Aspartate and N-acetylaspartate (NAA), which does look very relevant to autism.

Amino Acids in Autism

Amino Acids (AAs) are very important to health and it is important that all 20 are within the reference ranges, or there can be serious consequences.  Inborn errors of amino acid metabolism do exist and there are metabolic disorders which impair either the synthesis and/or degradation of amino acids.

It has been suggested that a lack of certain amino acids might underlie some people’s autism. This seems to be the basis of one new autism drug, CM-AT, being developed in the US, but this idea remains somewhat controversial.

In those people who have normal levels of amino acids, potential does exist to modify their level for some therapeutic effect. 

Examples include:-

·        Using histidine to inhibit mast cells de-granulating and so reducing symptoms of allergy

·       Using the 3 branch chained AAs to reduce the level of the AA, phenylanine, which can drive movement disorders/tics

·       Methionine seems to promote speech in regressive autism, but for no known reason.

·        Some AAs, such as leucine, activate mTOR. It is suggested that others (histidine, lysine and threonine) can inhibit it, which might have a therapeutic benefit in those with too much mTOR signaling.

·        D-Serine, synthesized in the brain by from L-serine, serves as a neuromodulator by co-activating NMDA receptors.  D-serine has been suggested for the treatment of negative symptoms of schizophrenia

·        Aspartic acid is an NMDA agonist

·       Threonine is being studied as a possible therapy for Inflammatory Bowel Disease (IBD), because it may increase intestinal mucin synthesis.

Amino acids, the building blocks for proteins

To make a protein, a cell must put a chain of amino acids together in the right order. It makes a copy of the relevant DNA instruction in the cell nucleus, and takes it into the cytoplasm, where the cell decodes the instruction and makes many copies of the protein, which fold into shape as they are produced.

There are 20 standard or “canonical” amino acids, which can be thought of as protein building blocks.

Humans can produce 10 of the 20 amino acids; the others must be supplied in the food and are called “essential”. The human body does not store excess amino acids for later use, so these amino acids must be in your food every day.

The 10 amino acids that we can produce are alanine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine and tyrosine. Tyrosine is produced from phenylalanine, so if the diet is deficient in phenylalanine, tyrosine will be required as well.

The essential amino acids (marked * below) are arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

The three so-called branched-chain amino acids (BCAAs) are leucine, isoleucine and valine

The so-called aromatic amino acids (AAAs) are histidine, phenylanine, tryptophan and tyrosine

When plasma levels of BCAAs increase, this reduces the absorption of aromatic AAs; so the level of tryptophan, tyrosine, and phenylalanine will fall and this directly affects the synthesis and release of serotonin and catecholamines.

Many sportsmen, and indeed soldiers, take BCAA supplements in an attempt to build stronger muscles, but within the brain this will cause a cascade of other effects.

In people with tardive dyskinesia, which is a quite common tic disorder found in schizophrenia and autism, taking phenylalanine may make their tics worse.  It seems that taking BCAA supplements may make their tics reduce, because reducing the level of phenylalanine will impact dopamine (a catecholamine). Most movement disorders ultimately relate to dopamine.

Tardive Dyskinesia Exacerbated after Ingestion of Phenylalanine by Schizophrenic Patients

In effect, BCAA supplements affect the synthesis and release of serotonin and catecholamines.  This might be good for you, or might be bad for you; it all depends where you started from.

   Alanine
   Arginine *
   Asparagine
   Aspartic acid
   Cysteine
   Glutamic acid
   Glutamine
   Glycine
   Histidine * Aromatic
   Isoleucine * BCAA
   Leucine * BCAA
   Lysine *
   Methionine *
   Phenylalanine *  Aromatic
   Proline
   Serine
   Threonine *
   Tryptophan * Aromatic
   Tyrosine  Aromatic
   Valine *  BCAA

Blood levels of the BCAAs are elevated in people with obesity and those with insulin resistance, suggesting the possibility that BCAAs contribute to the pathogenesis of obesity and diabetes.  BCAA-restricted diets improve glucose tolerance and promote leanness in mice.

BRANCHED-CHAIN AMINO ACIDS AND THE BRAIN

In the brain, BCAAs have two important influences on the production of neurotransmitters. As nitrogen donors, they contribute to the synthesis of excitatory glutamate and inhibitory gamma-aminobutyric acid (GABA) They also compete for transport across the blood-brain barrier (BBB) with tryptophan (the precursor to serotonin), as well as tyrosine and phenylalanine (precursors for catecholamines)Ingestion of BCAAs therefore causes rapid elevation of the plasma concentrations and increases uptake of BCAAs to the brain, but diminishes tryptophan, tyrosine, and phenylalanine uptake. The decrease in these aromatic amino acids directly affects the synthesis and release of serotonin and catecholamines. The reader is referred to Fernstrom (2005) for a review of the biochemistry of BCAA transportation to the brain. Oral BCAAs have been examined as treatment for neurological diseases such as mania, motor malfunction, amyotrophic lateral sclerosis, and spinocerebral degeneration. Excitotoxicity as a result of excessive stimulation by neurotransmitters such as glutamate results in cellular damage after traumatic brain injury (TBI). However, because BCAAs also contribute to the synthesis of inhibitory neurotransmitters, it is unclear to what extent the role of BCAAs in synthesis of both excitatory and inhibitory neurotransmitters might contribute to their potential effects in outcomes of TBI.

A list of human studies (years 1990 and beyond) evaluating the effectiveness of BCAAs in providing resilience or treating TBI or related diseases or conditions (i.e., subarachnoid hemorrhage, intracranial aneurysm, stroke, anoxic or hypoxic ischemia, epilepsy) in the acute phase is presented in Table 8-1; this also includes supporting evidence from animal models of TBI. The occurrence or absence of adverse effects in humans is included if reported by the authors.

Cell Signaling

Leucine indirectly activates p70 S6 kinase as well as stimulates assembly of the eIF4F complex, which are essential for mRNA binding in translational initiation. P70 S6 kinase is part of the mammalian target of rapamycin complex (mTOR) signaling pathway.

The actions of exogenous leucine on mTOR signalling and amino acid transporters in human myotubes

The present study provides the first evidence that mTOR signalling is enhanced in response to an acute stimulation with the proteinogenic amino acid, leucine, within cultured human myotubes. While these actions appear transient at the leucine dose utilised, activation of mTOR and p70S6K occurred at physiologically relevant concentrations independently of insulin stimulation. Interestingly, activation of mTOR signalling by leucine occurred in the absence of changes in the expression of genes encoding both the system A and system L carriers, which are responsible for amino acid transport. Thus, additional analyses are required to investigate the molecular mechanisms controlling amino acid transporter expression within skeletal muscle. Of note was the increased protein expression of hVps34, a putative leucine-sensitive kinase which intersects with mTOR. These results demonstrate the need for further clinical analysis to be performed specifically investigating the role of hVps34 as a nutrient sensing protein for mTOR signalling.

Dexamethasone and BCAA Failed to Modulate Muscle Mass and mTOR Signaling in GH-Deficient Rats

Skeletal muscle mass is determined by the balance between the synthesis and degradation of muscle proteins. Several hormones and nutrients, such as branched-chain amino acids (BCAAs), stimulate protein synthesis via the activation of the mammalian target of rapamycin (mTOR).

BCAAs (i.e., leucine, isoleucine, and valine) also exert a protective effect against muscle atrophy. We have previously reported that orally administered BCAA increases the muscle weight and cross-sectional area (CSA) of the muscle in rats

Metabolic and Physiological Roles of Branched-Chain Amino Acids

3.4. BCAAs in Brain Functions

BCAAs may also play important roles in brain function. BCAAs may influence brain protein synthesis and production of energy and may influence synthesis of different neurotransmitters, that is, serotonin, dopamine, norepinephrine, and so forth, directly or indirectly. Major portion of dietary BCAAs is not metabolized by liver and comes into systemic circulation after a meal. BCAAs and aromatic AA, such as tryptophan (Trp), tyrosine (Tyr), and phenylalanine (Phe), share the same transporter protein to transport into brain. Trp is the precursor of neurotransmitter serotonin; Tyr and Phe are precursors of catecholamines (dopamine, norepinephrine, and epinephrine). When plasma concentration of BCAAs increases, the brain absorption of BCAAs also increases with subsequent reduction of aromatic AA absorption. That may lead to decrease in synthesis of these related neurotransmitters [3]. Catecholamines are important in lowering blood pressure. When hypertensive rats were injected with Tyr, their blood pressure dropped markedly and injection with equimolar amount of valine blocks that action [49]. In vigorous working persons, such as in athletes, depletion of muscle and plasma BCAAs is normal. And that depletion of muscle and plasma BCAAs may lead to increase in Trp uptake by brain and release of serotonin. Serotonin on the other hand leads to central fatigue. So, supplementation of BCAAs to vigorously working person may be beneficial for their performance and body maintenance

Example of a treatable Amino Acid variant of Autism

Mutations in BCKD-kinase lead to a potentially treatable form of autism with epilepsy.

Autism Spectrum Disorders (ASD) are a genetically heterogeneous constellation of syndromes characterized by impairments in reciprocal social interaction. Available somatic treatments have limited efficacy. We have identified inactivating mutations in the gene BCKDK (Branched Chain Ketoacid Dehydrogenase Kinase) in consanguineous families with autism, epilepsy and intellectual disability (ID). The encoded protein is responsible for phosphorylation-mediated inactivation of the E1-alpha subunit of branched chain ketoacid dehydrogenase (BCKDH). Patients with homozygous BCKDK mutations display reductions in BCKDK mRNA and protein, E1-alpha phosphorylation and plasma branched chain amino acids (BCAAs). Bckdk knockout mice show abnormal brain amino acid profiles and neurobehavioral deficits that respond to dietary supplementation. Thus, autism presenting with intellectual disability and epilepsy caused by BCKDK mutations represents a potentially treatable syndrome.

The data suggest that the neurological phenotype may be treated by dietary supplementation with BCAAs. To test this hypothesis, we studied the effect of a chow diet containing 2% BCAAs or a BCAA-enriched diet, consisting of 7% BCAAs, on the neurological phenotypes of the Bckdk^−/− mice. Mice raised on the BCAA-enriched diet were phenotypically normal. On the 2% BCAA diet, however, Bckdk^−/− mice had clear neurological abnormalities not seen in wild-type mice, such as seizures and hindlimb clasping, that appeared within 4 days of instituting the 2% BCAA diet (Fig. 3B). These neurological deficits were completely abolished within a week of the Bckdk^−/− mice starting the BCAA-enriched diet, which suggests that they have an inducible yet reversible phenotype (Fig. 3C).

Our experiments have identified a Mendelian form of autism with comorbid ID and epilepsy that is associated with low plasma BCAAs. Although the incidence of this disease among patients with autism and epilepsy remains to be determined, it is probably quite a rare cause of this condition. We have shown that murine Bckdk^−/− brain has a disrupted amino acid profile, suggesting a role for the BBB in the pathophysiology of this disorder. The mechanism by which abnormal brain amino acid levels lead to autism, ID, and epilepsy remains to be investigated. We have shown that dietary supplementation with BCAAs reverses some of the neurological phenotypes in mice. Finally, by supplementing the diet of human cases with BCAAs, we have been able to normalize their plasma BCAA levels (table S10), which suggests that it may be possible to treat patients with mutations in BCKDK with BCAA supplementation.

(Look at the three red rows, the BCAAs, all lower than the reference range, before supplementation)

Threonine, Mucin and Akkermansia muciniphila in Autism

Mucins are secreted as principal components of mucus by mucous membranes, like the lining of the intestines.  People with Inflammatory Bowel Disease (IBD) have mucus barrier changes.

The low levels of the mucolytic bacterium Akkermansia muciniphila found in children with autism, apparently suggests mucus barrier changes.

The amino acid Threonine is a component of mucin and Nestle have been researching for some time the idea of a threonine supplement to treat Inflammatory Bowel Disease (IBD), being a serious Swiss company they publish their research.      

Threonine Requirement in IBD Adults and Healthy Adult Controls

Threonine Requirement in Healthy Adult Subjects and in Patients With Crohn's Disease and With Ulcerative Colitis Using the Indicator Amino Acid Oxidation (IAAO) Methodology

Threonine is an essential amino acid which must be obtained from the diet. It is a component of mucin. Mucin, in turn, is a key protein in the mucous membrane that protects the lining of the intestine.

Inflammatory bowel disease (IBD) is a group of inflammatory conditions that affect the colon and small intestine. IBD primarily includes ulcerative colitis (UC) and Crohn's disease (CD). In UC, the inflammation is usually in the colon whereas in CD inflammation may occur anywhere along the digestive tract. Studies in animals have shown that more threonine is used when there is inflammation in the intestine.

The threonine requirement in healthy participants and in IBD patients will be determined using the indicator amino acid oxidation method. The requirement derived in healthy participants will be compared to that derived in patients with IBD.

Each participant will take part in two x 3 day study periods. The first two days are called adaptation days where the subjects will consume a liquid diet specially designed for him. The diet will be consumed at home. It contains all vitamins, minerals, protein and all other nutrients required. On the third day, the participant will come to the Hospital for Sick Children in Toronto. Subjects will consume hourly meals for a total of 8 meals and a stable isotope 13C-phenylalanine. Breath and urine samples will be collected to measure the oxidation of phenylalanine from which the threonine requirement will be determined. 

Dietary Threonine Restriction Specifically Reduces Intestinal Mucin Synthesis in Rats

We determined whether the steady-state levels of intestinal mucins are more sensitive than total proteins to dietary threonine intake. For 14 d, male Sprague-Dawley rats (158 ± 1 g, n = 32) were fed isonitrogenous diets (12.5% protein) containing 30% (group 30), 60% (group 60), 100% (control group), or 150% (group 150) of the theoretical threonine requirement for growth. All groups were pair-fed to the mean intake of group 30. The mucin and mucosal protein fractional synthesis rates (FSR) did not differ from controls in group 60. By contrast, the mucin FSR was significantly lower in the duodenum, ileum, and colon of group 30 compared with group 100, whereas the corresponding mucosal protein FSR did not differ. Because mucin mRNA levels did not differ between these 2 groups, mucin production in group 30 likely was impaired at the translational level. Our results clearly indicate that restriction of dietary threonine significantly and specifically impairs intestinal mucin synthesis. In clinical situations associated with increased threonine utilization, threonine availability may limit intestinal mucin synthesis and consequently reduce gut barrier function.

  

Mucin glycan foragingin the human gut microbiome

It has been proposed that excessive mucin degradation by intestinal bacteria may contribute to intestinal disorders, as access of luminal antigens to the intestinal immune system is facilitated. However, it is not known whether all mucin-degraders have the same effect. For example A. muciniphila may possess anti-inflammatory properties, as a high proportion of the bacteria has been correlated to protection against inflammation in diseases such as type 1 diabetes mellitus, IBD, atopic dermatitis, autism , type 2 diabetes mellitus, and.

Low Relative Abundances of the Mucolytic Bacterium Akkermansia muciniphila and Bifidobacteriumspp. in Feces of Children with Autism

Gastrointestinal disturbance is frequently reported for individuals with autism. We used quantitative real-time PCR analysis to quantify fecal bacteria that could influence gastrointestinal health in children with and without autism. Lower relative abundances of Bifidobacteria species and the mucolytic bacterium Akkermansia muciniphila were found in children with autism, the latter suggesting mucus barrier changes. 

Previous studies in rats by MacFabe et al. have shown that intraventricular administration of propionate induces behaviors resembling autism (e.g., repetitive dystonic behaviors, retropulsion, seizures, and social avoidance) (12, 13). We have also reported increased fecal propionate concentrations in ASD children compared with that in controls in the same fecal samples (25). However, the abundance of a key propionate-producing bacterium, Prevotella sp., was not significantly different between the study groups. This suggests that other untargeted bacteria, such as those from Clostridium cluster IX, which also includes major propionate producers (24), may be responsible for the observed differences in fecal propionate concentrations. Moreover, it is possible that the activities of the bacteria responsible for producing propionate, rather than bacterial numbers, have been altered. Other factors, such as differences in GI function that change GI transit time in ASD children, should also be considered.

In summary, the current findings of depleted populations of A. muciniphila and Bifidobacterium spp. add to our knowledge of the changes in the GI tracts of ASD children. These findings could potentially guide implementation of dietary/probiotic interventions that impact the gut microbiota and improve GI health in individuals with ASD.

Conclusion

I think that modifying levels of amino acids can have merit for some people, but it looks like another case for personalized medicine, rather than the same mix of powders given to everyone.

Threonine is interesting given the incidence of Inflammatory Bowel Disease (IBD) in autism.  IBD mainly describes ulcerative colitis and Crohn's disease.

The research into Threonine, is being funded by Nestle, the giant Swiss food company, who fortunately do publish their research.

The trial in the US of CM-AT is unusual because no results have ever been published in the literature, so we just have press releases. It likely that CM-AT is a mixture of pancreatic enzymes from pigs and perhaps some added amino acids.

http://www.prweb.com/releases/2017/02/prweb14088362.htm

This 14-week, double-blind, randomized, placebo-controlled Phase 3 study is being conducted to determine if CM-AT may help improve core and non-core symptoms of Autism. CM-AT, which has been granted Fast Track designation by FDA, is designed to enhance protein digestion thereby potentially restoring the pool of essential amino acids. Essential amino acids play a critical role in the expression of several genes important to neurological function and serve as precursors to key neurotransmitters such as serotonin and dopamine.

Based on the study I referred to early this year:-

Dietary interventions that reduce mTOR activity rescue autistic-like behavioral deficits in mice 

·        Amino acids, his, lys and thr, inhibited mTOR pathway in antigen-activated mast cells

·     Amino acids, his, lys and thr inhibited degranulation and cytokine production of mast cells

·     Amino acid diet reversed mTOR activity in the brain and behavioral deficits in allergic and BTBR mice.

in my post:

Histidine for Allergy, but as an effective MTOR inhibitor?

I for one will be evaluating both lysine and threonine, having already found a modest dose histidine very beneficial in allergy (stabilizing mast cells).