A RORα Agonist for Autism?

Today’s post is again about RORα, which was suggested to be a nexus where different biological dysfunctions that lead to autism may converge. I think you can consider RORα like a dimmer switch on your lights, you need to adjust the brightness to give the effect you want.

Fine tuning RORα to tune autism gene expression

I recently came across some research where the scientist clearly has the same idea. He has been working on a synthetic RORα/γ agonist for some years and has investigated its use as both a cancer therapy and an autism therapy.

I have become rather interested in cancer therapies because there are so many overlaps between what can lead to cancer and what exists in autism. The big research money is of course in cancer research.

Tumor suppressor genes/proteins like PTEN and p53 have been shown to be disturbed in autism, as is Bcl-2. The Bcl-2 family of proteins regulate cell death (apoptosis); some members induce cell death and other inhibit it; the balance is important.

Generally it seems that most people with autism might benefit from more PTEN and Bcl-2. 

Therapeutic Effect of a Synthetic RORα/γ Agonist in an Animal Model of Autism  

Autism is a developmental disorder of the nervous system associated with impaired social communication and interactions as well excessive repetitive behaviors. There are no drug therapies that directly target the pathology of this disease. The retinoic acid receptor-related orphan receptor α (RORα) is a nuclear receptor that has been demonstrated to have reduced expression in many individuals with autism spectrum disorder (ASD). Several genes that have been shown to be downregulated in individuals with ASD have also been identified as putative RORα target genes. Utilizing a synthetic RORα/γ agonist, SR1078, that we identified previously, we demonstrate that treatment of BTBR mice (a model of autism) with SR1078 results in reduced repetitive behavior. Furthermore, these mice display increased expression of ASD-associated RORα target genes in both the brains of the BTBR mice and in a human neuroblastoma cell line treated with SR1078. These data suggest that pharmacological activation of RORα may be a method for treatment of autism. 

The RORs have been linked to autism in human in several studies. In 2010, Nguyen and co-workers reported that RORα protein expression was significantly reduced in the brains of autistic patients and this decrease in expression was attributed to epigenetic alterations in the RORA gene.¹⁵ Additional work from this group demonstrated that multiple genes associated with autism spectrum disorder are direct RORα target genes and suggested that reduction of RORα expression results in reduced expression of these genes associated with the disorder leading to the disease.¹⁶ Independently, Devanna and Vernes demonstrated that miR-137, a microRNA implicated in neuropsychiatric disorders, targets a number of genes associated with autism spectrum disorder including RORA.¹⁷ There are also additional links between RORα and autism. Deficiency of Purkinje cells is one of the most consistently identified neuroanatomical abnormalities in brains from autistic individuals^18,19 and RORα is critical in development of the Purkinje cells.²⁰⁻²³ Significant circadian disruptions have also been recognized in autistic patients,²⁴⁻²⁷ and RORs play a critical role in regulation of the circadian rhythm.^7,28 Additionally, the staggerer mouse displays behaviors that are associated with autism including abnormal spatial learning, reduced exploration, limited maze patrolling, and perseverative behavior relative to wt mice.²⁹⁻³³

SR1078 is a relatively low potency compound with limited RORα efficacy (3–5 μM EC₅₀E_max ∼ 40%),⁸ but the efficacy compares favorably to other classes of compounds that have been optimized such as a 38% decrease in the same model induced by the mGluR5 allosteric modulator GRN-529⁴⁹ and a 47% reduction by the mGluR5 antagonist MPEP.⁴⁵ Both of these compounds have been optimized and display high potency (single digit nanomolar range at mGluR5) and strong efficacy.^53,54 Thus, we believe that focused optimization of RORα ligands will provide compounds that will have improved efficacy in this model. It should also be noted that SR1078 has both RORα and RORγ agonist activity⁸ and a RORα selective agonist has not yet been developed. Thus, it is possible that the RORγ activity of this compound may also play a role in its efficacy in this model of autism. In summary, we have demonstrated that a synthetic RORα/γ agonist is able to increase the expression of key genes whose decrease in expression is associated with ASD both in cell culture and in vivo. Furthermore, the agonist decreases repetitive behavior in an animal model of autism suggesting that it is possible that ROR agonists may hold utility in treatment ASD. 

Regulation of p53 Stability and Apoptosis by a ROR Agonist

Activation of p53 function leading to cell-cycle arrest and/or apoptosis is a promising strategy for development of anti-cancer therapeutic agents. Here, we describe a novel mechanism for stabilization of p53 protein expression via activation of the orphan nuclear receptor, RORα. We demonstrate that treatment of cancer cells with a newly described synthetic ROR agonist, SR1078, leads to p53 stabilization and induction of apoptosis. These data suggest that synthetic ROR agonists may hold utility in the treatment of cancer.  

Levels of Bcl-2 and P53 Are Altered in Superior Frontal and Cerebellar Cortices of Autistic Subjects 

Results showed that levels of Bcl-2 decreased by 38% and 36% in autistic superior frontal and cerebellar cortices, respectively when compared to control tissues. By the same token, levels of P53 increased by 67.5% and 38% in the same brain areas in autistic subjects vs. controls respectively. Calculations of ratios of Bcl-2/P53 values also decreased by 75% and 43% in autistic frontal and cerebellar cortices vs. controls respectively. The autistic cerebellar values were significantly reduced (p < 0.08) vs. control only. There were no significant differences in levels of β-actin between the two groups. Additionally, there were no correlations between Bcl-2, P53, and β-actin concentrations vs. age or PMI in either group.

These results confirm and extend previous data that levels of Bcl-2 and P53 are altered in three important brain tissues, i.e. frontal, parietal, and cerebellar cortices of autistic subjects, alluding to deranged apoptotic mechanisms in autism.  

Conclusion

Increasing PTEN and Bcl-2 is already part of my Polypill, via the use of Atorvastatin.

There are of course many other genes miss-expressed in autism and we cannot give a drug for each one. We need to identify a handful of nexus, where multiple anomalies can be resolved with a single intervention.

It is good that Thomas Burris, the lead researcher, has been working on SR1078 for at least 6 years, let’s hope he continues to persevere.

I think it highly likely that some types of autism will need the opposite therapy, a RORα antagonist.

My method of attempting to modulate RORα will be different. I come back to my earlier gross simplification of autism :- 

As we have seen in earlier posts, the hormonal dysfunction, this time the balance between testosterone and estradiol, has a direct effect on RORα (and vice versa).

The schematic illustrates a mechanism through which the observed reduction in RORA in autistic brain may lead to increased testosterone levels through downregulation of aromatase. Through AR, testosterone negatively modulates RORA, whereas estrogen upregulates RORA through ER.

androgen receptor = AR 

estrogen receptor = ER

As you might know, many hormones are interrelated, so what are thought of as male/female sex hormones have much wider effects. They impact growth hormones and play a big role in calcium metabolism. They also affect serotonin.

We know that in most autism aromatase is reduced, estradiol is reduced and that there is reduced expression of estrogen receptor beta.

In the ideal world it might indeed be best to use an agonist or antagonist to fine tune RORα.

We have a chicken and the egg situation. Is RORα out of tune in autism because the hormones are disturbed, or vice versa?

We do know that hormones generally have feedback loops, but we also know that increasing a hormone like estradiol via obesity is not fully matched by a corresponding reduction in aromatase. So it looks highly plausible that you can tune RORα via estradiol, and that this could be a long term strategy, not just a short term strategy.

In the case of people with low T3 thyroid hormone centrally (in the brain), giving exogenous T3 may help initially, but in the long term it does not because feedback loops to the thyroid will reduce production of the pro-hormone T4. In the extreme you will make the thyroid gland shut down, this does happen to people using thyroid hormones for depression and even weight loss. 

T3 is quite commonly prescribed by alternative practitioners in the US for autism and also for depression in older people. In Europe this hormone is rarely even available. 

Many phytoestrogens are used as OTC autism therapies. These are dietary estrogens that are structurally similar to the human hormone estradiol and so produce estrogen-like effects. They include soy products, fenugreek, kudzu, EGCG etc.

More Wnt Modulation for Autism and More Inexpensive Potential Cancer Therapies

This blog is of course meant to be about autism, but today it is again more about cancer, since I keep coming across interesting potential therapies while researching Wnt/PAK/hedgehog therapies for autism.

On their way to visit a pharmacy?

It really looks like daily use of Mebendazole should be beneficial in some types of autism and perhaps a little short term bioavailability boost from cimetidine might help get things started. There are anecdotes on the internet of people with autism using it for its anti-parasite properties and showing a behavioral improvement.

Wnt signalling is highly complex and yet still only partially understood. One interesting role of Wnt signalling is in controlling the flow of calcium ions within cells. The non-canonical Wnt/calcium pathway helps to regulate calcium release from the endoplasmic reticulum (ER) in order to control intracellular calcium levels. Wnt ultimately causes the release of IP3 which then binds to the receptor IP3R which causes calcium to be released from the ER. Problems with this calcium release triggered by IP3R were put forward by Prof Gargus as a possible nexus where different genetic types of autism come together, but he does not translate this thinking into potential therapies. IP3R has been covered in earlier posts.  

Is dysregulated IP3R calcium signaling a nexus where genes altered in ASD converge to exert their deleterious effect?

The Excitatory/Inhibitory Imbalance – GABAA stabilization via IP3R

Wnt signalling also plays a role in dendritic spine morphology, which I wrote about at length previously. In autism the synaptic pruning process does not result in the optimal structure, but even after this process has been completed it is possible to fine tune brain function by changing the shape of the dendritic spines that remain. This dendritic spine morphology can be modulated by Wnt signalling. 

It appears that either a Wnt activator or a Wnt inhibitor may be required to improve dendritic spine morphology depending on the person and the nature of their dysfunction. In a bipolar mouse model, lithium was used as a Wnt activator to create a denser structure of dendritic spines and a more functional mouse. My assumption is that in my case I need a Wnt inhibitor. This is the same situation we have observed with the better known mTOR pathway, where some people are hypo while others are hyper.

Many drugs that have some effect in autism do play a role in Wnt signalling, even Atorvastatin, in my Polypill, has an inhibitory effect.

Wnt signalling is a conserved evolutionary pathway so it is present in everything from fruit flies to humans. It plays a role in many cancers, type 2 diabetes and it seems in neurological conditions such as autism, bipolar and schizophrenia.

My earlier posts on Wnt and PAK1 ended up with 3 options:-

·      Ivermectin

·      FRAX486

·      Bio30 Propolis

The Bio30 propolis is put forward as a PAK inhibitor, but I think it is too weak unless used in huge quantities. I did try BIO 30 and I think it may have had a marginal effect, but it is expensive and you need a lot of it.

So I think Mebendazole, as a Wnt inhibitor, looks like an alternative more practical route to achieve the same thing.

Roche do not seem to be commercializing FRAX486, whereas Mebendazole is sitting in the OTC part of most pharmacies across the world (excluding the USA). Under the brand name Vermox, pharmacies in New Zealand legally sell it worldwide.
If Mebendazole has potency to have an anti-cancer effect, like FRAX486, then it should have potency to give an autism effect.

Note that some people may need a Wnt activator.

You can read all about Wnt at this Stanford lab here.

Back to Cancer

Cancer appears to be more common among people with autism and so it was to be expected that some readers of this blog are treating both autism and some type of cancer.

It does seem that there is scope to repurpose some very common generic drugs to improve the prognosis of many cancers. As with autism, there is great resistance among mainstream clinicians to do this.

As with autism, there are hundreds of sub-types of cancer and so it is not easy to collect relevant evidence, even in the best circumstances, so often it is a case of anecdotes. It is hard to prove anything conclusively, but some very expensive cancer therapies are only minimally effective. As with autism, even a moderate chance of success is worth pursuing and none of the mentioned potentially “repurposable” drugs have more than trivial side effects. Many ultra-expensive dedicated cancer drugs have side effects that are far from trivial and some have very limited benefit.

It seems that while many clinicians are aware of the potential benefit of these off-label therapies, very few prescribe them. Some seem quite happy if you get them somewhere else, which in the case of Prof Williams (see below) from San Diego means regular trips across the border to a pharmacy in Tijuana, Mexico.

Cimetidine for cancer

I did mention cimetidine in my last post.

Cimetidine (Tagamet) is an H2 antihistamine that lowers acidity in your stomach, but cimetidine does much more, it even increases your level of estrogen, which may help some autism. The anti-cancer effects of cimetidine are well documented, they come in part from its own actions and in part from interfering with how the prescribed cancer drugs are metabolized. Cimetidine increases the plasma concentration of numerous drugs including some anticancer drugs.

There are various different theories to explain the anticancer effects of cimetidine itself, but what looks clear is that it improves the prognosis of many types of cancer.
You might expect it to have a negative effect on the types of cancers that have estrogen receptors.

Desloratadine for cancer

On the subject of antihistamines, the OTC second generation antihistamine Desloratadine (Clarinex, Aerius)  has been shown to improve outcomes in breast cancer. As usual drugs have multiple modes of action and so the anticancer effect may have nothing to do with histamine. The data to support this anticancer effect comes from Sweden and the data is presented in the patent application below.

Patent - Antihistamine for use in treatment of breast cancer

Perhaps one mode of anti-cancer action is the following one:-

The antihistamines clemastine anddesloratadine inhibit STAT3 and c-Myc activities and induce apoptosis incutaneous T-cell lymphoma cell lines.

Generic drugs with anti-cancer properties

So far we have covered in the last post and this one:

·      Ivermectin

·      Mebendazole (Vermox)

·      Albendazole

·      Cimetidine (Tagamet)

·      Statins (particularly Simvastatin, but also Atorvastatin)

·      Metformin

·      Desloratadine (Clarinex, Aerius)

·      Suramin (but use is limited by toxicity at high doses)

An antifungal treatment, Itraconazole, has an effect inhibiting hedgehog signaling, relevant to many cancers and has been shown to have some effect on prostate and breast cancer in particular. This might also have an effect in some autism where hedgehog signalling is elevated.

Repurposing Drugs in Oncology (ReDO)—itraconazole as an anti-cancer agent

Zinc, Hedgehog Signaling, Shank2/3, NMDA/AMPA Inactivation and Autism

Itraconazole does not work well with drugs that lower stomach acidity, like H2 antihistamines and PPIs.

The Polypill approach to cancer

I was looking for information to support the possible effect of Mebendazole in autism and I came across a great example of someone with my approach treating his brain tumor. With good sense he was seeking to follow mainstream therapy, but to supplement it with science based off-label therapies.

The professor who'cured' his cancer with a cocktail of everyday pills and 20 years on remains disease-free

The Drugs in Question: the evidence for and against

Metformin: Several studies suggest that tumors grow more slowly in cancer patients who take this anti-diabetic drug. Early-stage clinical trials are investigating its potential to prevent various cancers including prostate, breast, colorectal and endometrial.

Statins: Preclinical studies suggest these cholesterol-lowering heart drugs may prevent various cancers and stop them spreading. One recent meta-analysis associated a daily statin with a significant risk reduction of liver cancer.

Mebendazole: There is evidence this drug – usually prescribed to treat parasitical worm infections — may inhibit cancer cell growth and secondary tumors, though no clinical trials have been completed.

Cimetidine: This over-the-counter antacid has direct anti-proliferative effects on cancer cells, inhibits cell adhesion, reduces tumor angiogenesis (growth of blood vessels essential to a developing tumor) and also boosts anti-cancer immunity in various cancers.

Itraconazole: The common anti-fungal treatment is also thought to be anti-angiogenic and has shown promise as an agent for prostate cancer, non-small cell lung cancer and basal cell carcinoma, the most common kind of skin cancer.

Isotretinoin: This acne drug, marketed as Accutane, is occasionally used to treat certain skin cancers and neurological cancers as well as to prevent the recurrence of some brain tumors, although some studies suggest it is ineffective.

Professor Williams is not a doctor, but that did not stop him reading the research.

His choice of cheap generic off-label anti-cancer drugs looks pretty smart to me. He is still alive two decades after he “should” have been dead. It may all be a happy coincidence and perhaps he would have survived his orange-sized brain tumor without his own interventions. 

There are numerous alternative therapies for cancer and some people do even forgo conventional therapies to treat themselves, which looks very foolish to me.

Personally I would put my faith in science and that does not necessarily mean just medicine. Medicine is based on an evidence-based selective interpretation of often out of date science. So in some fields, medicine works just great, but in complex areas like cancer or anything to do with the brain, medicine lags decades behind science.

As Prof Williams learned, evidence is great as long as you are not going to die before someone collects it. If you have only a year to live what do you really care about any minor side effects metformin, simvastatin or cimetidine may have?

There are some apparently nutty therapies for cancer, just as there are for autism; I think someone should investigate them anyway, just in case someone has stumbled upon something effective by accident.

Modulating Wnt Signaling in Autism and Cancer

Source: LDL receptor-related proteins 5 and 6 in Wnt/β-catenin signaling: Arrows point the way

In earlier posts I have covered various signaling pathways such as Wnt, mTOR and the unusually sounding Hedgehog.

You can go into huge detail if you want to understand these pathways, or just take a more superficial view. In most cases, things only start to go wrong if you are hypo/hyper (too little/too much) in these pathways.

We saw with mTOR that most people with autism are likely to have too much activity and so might benefit from mTOR inhibition, but a minority will have the opposite status and stand to benefit from more mTOR activity.

When it comes to Wnt signaling the research suggests the same situation. Wnt signaling is likely to be aberrant, but both extremes exist.

Wnt signaling networks in autism spectrum disorder and intellectual disability

Given the large volume of genetic data, analyzing each gene on its own is not a feasible approach and will take years to complete, let alone attempt to use the information to develop novel therapeutics. To make sense of independent genomic data, one approach is to determine whether multiple risk genes function in common signaling pathways that identify signaling “hubs” where risk genes converge. This approach has led to multiple pathways being implicated, such as synaptic signaling, chromatin remodeling, alternative splicing, and protein translation, among many others. In this review, we analyze recent and historical evidence indicating that multiple risk genes, including genes denoted as high-confidence and likely causal, are part of the Wingless (Wnt signaling) pathway. In the brain, Wnt signaling is an evolutionarily conserved pathway that plays an instrumental role in developing neural circuits and adult brain function.

While the human genetic data is an important supporting factor, it is not the only one. There are a number of mouse genetic knockout (KO) models targeting Wnt signaling molecules, describing molecular, cellular, electrophysiological, and behavioral deficits that are consistent with ASD and ID. Furthermore, the genes involved in Wnt signaling are of significant clinical interest because there are a variety of approved drugs that either inhibit or stimulate this pathway.

There are many drugs developed and tested as modulators of Wnt signaling in the cancer field that could potentially be repurposed for developmental cognitive disorders. In cases where a reduction in Wnt signaling is thought to underlie the pathology of the disorder, usage of compounds that elevated canonical Wnt signaling could be applied. An example of this is GSK-3β inhibitors that have failed in cancer trials but may be effective for ASDs and ID (e.g., Tideglusig, ClinicalTrials.gov identifier: {"type":"clinical-trial","attrs":{"text":"NCT02586935","term_id":"NCT02586935"}}NCT02586935). In cases where elevated Wnt signaling is thought to contribute to disease pathology, there are many potential options to inhibit canonical Wnt signaling using chemicals (Fig. 1) that inhibit the interaction between β-catenin and its targets (e.g., inhibiting β-catenin interaction with the TCF factors), disheveled inhibitors (through targeting of the PDZ domain which generally inhibit the Frizzled–PDZ interaction), and tankyrase inhibitors (e.g., XAV939, which induces the stabilization of axin by inhibiting the poly (ADP)-ribosylating enzymes tankyrase 1 and tankyrase 2)

As autism candidates emerge, cancer pathway rises to top

In recent years, strong autism ties have cropped up for one group of genes in particular: those that make up a well-known signaling pathway called WNT, which also has strong links to cancer. This pathway is especially compelling because some people with autism carry mutations in various members of it, including one of its central players: beta-catenin¹. What’s more, studies from the past year indicate that several of the strongest autism candidate genes, including CHD8 and PTEN, interact with this pathway.

“There might be a particular subgroup of genes associated with autism that could all be feeding into or be regulating this pathway,” says Albert Basson, reader in developmental and stem cell biology at King’s College London, who studies CHD8 and WNT. “That clearly has emerged as a relatively major theme over the last few years.”

The connection between cancer and some autism is over-activated pro-growth signaling pathways. Many signaling pathways have growth at one extreme and cell death at the other. In cancer you actually want cell death to suppress tumor growth; in much autism there is also too much growth.  

Many cancers are associated with elevated signaling of mTOR, Wnt and indeed Hedgehog.  These are targets for cancer drug therapy and so there is already a great deal known.

A complication is that in a developmental neurological condition, like autism, it also matters when these signaling pathways were/are disturbed. For example Wnt signaling is known to play a role in dendritic spines and synaptic pruning, some of this is an ongoing process but other parts are competed at an early age, so it would matter when you intervene to modulate these pathways.

Historically cancer therapies involve potent drugs, often with potent side effects, however in recent years there has been growing awareness that some safe existing drugs can have equally potent anti-cancer effects. Many of these drugs are anti-parasite drugs, but even the very widely used diabetes drug Metformin has been shown to have significant anti-cancer effects, not to forget Simvastatin.

Many autism pathways/genes play a role in cancer (RAS, PTEN) and the upstream targets considered in cancer research are also autism targets.  For example many human cancers are RAS dependent and in theory could be treated by a RAS inhibitor, but after decades of looking nobody has found one. So instead scientists go upstream to find another target that will indirectly reduce RAS. This led to the development of PAK1 inhibitors that will reduce RAS.

RAS plays a role in some types of intellectual disability and indeed autism. The collective term is RASopathy.  Logically, drugs that modulate RAS to treat cancer might be helpful in modulating RAS for some autism.

Most types of cancers are complex and so there are multiple potential targets to attack them, but also the same target can have multiple possible approaches. RAS dependent cancers can be targeted via Wnt and even Hedgehog signaling.

This may sound all very complicated but does it have any relevance to autism?

It apparently does because almost all these pathways are known to be disturbed hypo/hyper in autism.  This means that clever insights developed for cancer can be repurposed for autism.

Anti-parasite drugs and Cancer

It is indeed remarkable how many anti-parasite drugs have an anticancer effect and indeed there is a much maligned theory to justify this.

Clinical Evaluation of a New Form of Cancer Therapy Based on the Principles of Atavistic Metamorphosis

Quite possibly it is just a coincidence.

There are many ways to kill parasites, one of which involves starving them of ATP. ATP is the fuel that is produced in your mitochondria.

Cancer cells and many parasites use a very inefficient way to produce ATP that does not require oxygen. In normal human cells the process followed is known as OXPHOS, by which glucose and oxygen from the blood is converted into ATP (energy) is very efficient. Only when you run low on oxygen, like a marathon runner at the end of the race, can you run into trouble because there is not enough oxygen for OXPHOS.  What happens next is anaerobic respiration, when a different process takes over to make ATP. It is much less efficient and causes lactic acidosis which makes marathon runners' muscles hurt.

A cheap anti-parasite drug Pyrvinium targets anaerobic respiration and starves the parasite of ATP and thus kills it. Another common children’s anti-parasite drug albendazole also works by starving the parasite of ATP.

Other anti-parasite drugs work in different ways.

We already know from the autism trials of Suramin, another anti-parasite drug,  that it works via P2X and P2Y purinergic channels.

Ivermectin  binds to glutamate-gated chloride channels (GluCls) in the membranes of invertebrate nerve and muscle cells, causing increased permeability to chloride ions, resulting in cellular hyper-polarization, followed by paralysis and death.  Fortunately in mammals ivermectin does not cross the BBB.

Ivermectin is also a PAK1 inhibitor and a positive allosteric modulator of P2X7.

Both PAK1 and P2X7 are relevant to many cancers and so not surprisingly research shows that Ivermectin has an anti-cancer effect.

Ivermectin appears to have a positive effect in some autism, but strangely it does not cross the BBB.

Mebendazole is another extremely cheap children’s anti-parasite drug which has remarkable potential anti-cancer properties. It inhibits hedgehog signaling and, via the inhibition of TNIK, it is a Wnt inhibitor.

Unfortunately in the US the private sector has also noticed the anticancer effects of Mebendazole and albendazole and they have recently become astronomically expensive. Mebendazole (MBZ), which costs almost nothing in many countries, now costs hundreds of dollar per dose in the US under the name Emverm. Outside of the US, Mebendazole is OTC in many developed countries. In poor countries it is donated free by big pharma.

In the cancer research they consider taking advantage of the fact that cimetidine (a cheap H2 antihistamine) interacts with Mebendazole to increase its bioavailability. Cimetidine is by chance another generic drug also being considered to be repurposed for cancer.

While some anti-parasite drugs like Suramin have side effects or cannot be taken regularly like Ivermectin, others are seen as safe for continued use even at high doses (e.g. Mebendazole and albendazole).  

Anti-parasite drugs and Autism

Just as many anti-parasite drugs seem to have a positive effect on some cancers it looks likely that the same may be true for autism.  This does not mean that parasites cause either cancer or autism.

We know from Professor Naviaux that some people respond to Suramin.

Two people who comment on this blog have found their child responds to PAK1 inhibitors, one of which is the drug Ivermectin.

There are groups of people on the internet who think parasites cause autism and you will find some of them if you google “autism mebendazole”, but there are some very valid reasons why some people’s autism may respond to mebendazole, but nothing to do with little worms.

Potency of Anticancer drugs

Failed anticancer drugs are already considered as possible drugs to treat neurological conditions.

The same pathways do seem to be involved in some cancer and some neurological conditions, but the severity by which that pathway is affected may be very different, so a new drug may lack potency to treat a type of cancer but be potent enough to benefit others.

In the case of the anti-parasite drugs Ivermectin and indeed mebendazole the dosage being used in current cancer studies are very much higher than normally used.

Very little mebendazole makes its way out of your intestines and so researchers counter this by using a dose 15 times higher and even taking advantage of the interaction with the H2 antagonist cimetidine to boost bioavailability.

The standard human dose of Ivermectin is 3mg, but in the cancer trials (IVINCA trial - IVermectin IN CAncer) in Switzerland and Spain the trial dose is 12, 30 and 60 mg.

So when it comes to autism and the possible repurposing of these drugs, the cancer studies will give valuable safety information, but the likely dose required to fine-tune these signaling pathways will likely be a tiny fraction of the cancer dose.

The newly developed cancer drugs that fail in clinical trials, may have potential in autism but it is unlikely that anyone will develop them, test them and bring them to the market.

The clever thing for autism seems to be to keep an eye on the existing generic drugs considered to benefit the overlapping cancer pathways.

Conclusion

Aberrant Wnt signaling has been identified by researchers as playing a key role in autism; the Simons Foundation is among those now funding further research.

In practical terms you can be either hypo or hyper, but hyper seems more likely. It may be a case of shutting the stable door after the horse has bolted, because the ideal time to modulate Wnt signaling is probably as a baby, or before. Nonetheless some older people may indeed benefit from modulating Wnt; the Simons Foundation must also believe so.

In the case of people with hyperactive Wnt signaling, there is a case to make for the potential use of the cheap anti-parasite drug Mebendazole.

The drug Mebendazole (MBZ) can found in three states/polymorphs called Polymorph A, B or C. This is relevant because they do not cross the blood brain barrier to the same extent.

Brain Penetration and Efficacy of Different Mebendazole Polymorphs in a Mouse Brain Tumor Model  

To treat brain tumors, or indeed potentially some autism, you need MBZ-B or MBZ-C, it looks like MBZ-A does not cross the blood brain barrier.

Fortunately, MBZ-C is  the polymorph found most commonly in generic mebendazole tablets.  

Ivermectin is known not to cross the blood brain barrier but yet has been shown to show anti-tumor activity in brain cancer. The anti-cancer effect is thought to be as a PAK1 inhibitor, but this effect must be occurring outside the brain. Some people do use Ivermectin for autism.

The people using Ivermectin for autism are told they cannot use it continuously. Perhaps as the high dose cancer trials evolve the safety advice may change.

Histidine for Allergy, but as an effective MTOR inhibitor?

Today’s post is likely to be of interest to those dealing with allergy and mast cell activation, but it may have broader implications for those with excess brain mTOR activity.

In the jargon, we are told that:

“enhanced mammalian target of rapamycin (mTOR) signaling in the brain has been implicated in the pathogenesis of autism spectrum disorder”.

I have discussed mTOR and mTOR inhibitors previously on this blog.

Amino acids, not just for body builders?

mTOR plays a key role in aging and many human diseases ranging from cancer, diabetes and obesity to autism and Alzheimer’s.

The greatest interest in mTOR seems to be in cancer care.  Many cancer genes and pathways are also involved in autism, so we can benefit from the cancer research.  Another autism gene that is also a cancer gene is PTEN.  PTEN is a tumor suppressor and in the most common male cancer, prostate cancer (PCa), what happens is that PTEN gets turned off and so the cancer continues to grow.  If you upregulate PTEN you slow the cancer growth and if you upregulated this gene in those people at risk of Pca perhaps they would never develop this cancer in the first place?  PTEN is upregulated by statin-type drugs and people already on this type of drug have better PCa prognoses.   The beneficial of effect of statins on PCa is known, but the mechanism being PTEN upregulation does not seem to have been noticed. No surprise there.

Inhibiting mTOR using cancer drugs is very expensive.

Other substances affecting mTOR include amino acids, growth factors, insulin, and oxidative stress.

The amino acid Leucine is an mTOR activator, we don’t need that.  We actually want the opposite effect and, at least in mice, we can get it from some of the other amino acids. 

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

          Highlights 

·        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.

Neuroprotective and anti-inflammatory diet reduced behavioral deficits only in allergic mice.

              Abstract

Enhanced mammalian target of rapamycin (mTOR) signaling in the brain has been implicated in the pathogenesis of autism spectrum disorder (ASD). Inhibition of the mTOR pathway improves behavior and neuropathology in mouse models of ASD containing mTOR-associated single gene mutations. The current study demonstrated that the amino acids histidine, lysine, threonine inhibited mTOR signaling and IgE-mediated mast cell activation, while the amino acids leucine, isoleucine, valine had no effect on mTOR signaling in BMMCs. Based on these results, we designed an mTOR-targeting amino acid diet (Active 1 diet) and assessed the effects of dietary interventions with the amino acid diet or a multi-nutrient supplementation diet (Active 2 diet) on autistic-like behavior and mTOR signaling in food allergic mice and in inbred BTBR T + Itpr3tf/J mice. Cow’s milk allergic (CMA) or BTBR male mice were fed a Control, Active 1, or Active 2 diet for 7 consecutive weeks. CMA mice showed reduced social interaction and increased self-grooming behavior. Both diets reversed behavioral impairments and inhibited the mTOR activity in the prefrontal cortex and amygdala of CMA mice. In BTBR mice, only Active 1 diet reduced repetitive self-grooming behavior and attenuated the mTOR activity in the prefrontal and somatosensory cortices. The current results suggest that activated mTOR signaling pathway in the brain may be a convergent pathway in the pathogenesis of ASD bridging genetic background and environmental triggers (food allergy) and that mTOR over-activation could serve as a potential therapeutic target for the treatment of ASD.

  

So in mice a combination of the three amino acids Histidine, Lysine and Threonine reduced brain mTOR activity and improved autism.

I did look at all three of these amino acids and their other effects and I choose Histidine. 

Histidine can be produced in adult humans in very small amounts, but in young children they need to obtain some from other sources, usually dietary.

Histidine is the precursor of histamine.  Histamine has both good and bad effects.

Histidine decarboxylase (HDC) is the enzyme that catalyzes the reaction that produces histamine from histidine with the help of vitamin B₆ as follows:

You can treat allergy by inhibiting HDC.

Tritoqualine, is an inhibitor of the enzyme histidine decarboxylase and therefore an atypical antihistamine,

You might think that having extra histidine would result in extra histamine, but this appears not to be the case.  There is a paradoxical reaction where increasing histadine actually seems to reduce the release of histamine from the mast cells that store it.  This may indeed be a case of feedback loops working in our favour.

So it seems that histidine may give two different benefits, it reduces IgE-mediated mast cell activation and it reduces mTOR signalling in the brain.

If the effect on mTOR is sufficient we would then benefit from an increase in autophagy, the cellular garbage disposal service that does not work well in autism.  We might eventually see a benefit from increased synaptic pruning which might be seen in improved cognition.  

Recap on mTOR and Synaptic Pruning

This has been covered in earlier posts.

In autism loss of mTOR-dependent macro-autophagy causes synaptic pruning deficits; this results in too many dendritic spines.

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4159743/figure/F1/

A dendritic spine (or spine) is a small membranous protrusion from a neuron's dendrite that typically receives input from a single axon at the synapse. Dendritic spines serve as a storage site for synaptic strength and help transmit electrical signals to the neuron's cell body. The dendrites of a single neuron can contain hundreds to thousands of spines. In addition to spines providing an anatomical substrate for memory storage and synaptic transmission, they may also serve to increase the number of possible contacts between neurons.

A feature of autism is usually too many, but can be too few, dendritic spines.  In an earlier post we saw how the shape of individual spines affects their function.  The shape is constantly changing and can be influenced by external therapy. Wnt signaling affects dendritic spine morphology and so using this pathway you could fine-tune dendritic spine shape.  We did look at PAK1 inhibitors in connection with this.

Synaptic pruning is an ongoing process well into adolescence.

So it may be possible to improve synapse density and structure well after the onset of autism.

It should be noted that using Rapalogs, the usual mTOR inhibiting drugs, would have a negative effect in the minority of autism that feature hypo-active growth signalling.  That would be people born with small heads and small bodies.  So a child affected by the zika virus, might very likely exhibit autism and ID, but likely has too few dendritic spines and would then need more mTOR, rather than less.

Rapalog drugs like Everolimus are very expensive, but as in this recent paper do show effect in some autism. 

Everolimus improves neuropsychiatric symptoms in a patient with tuberous sclerosis carrying a novel TSC2 mutation

The mTOR pathway is a central regulator of mammalian metabolism and physiology, with important roles in the function of tissues including liver, muscle, white and brown adipose tissue, and the brain, and is dysregulated in human diseases, such as diabetes, obesity, depression, and certain cancers.

mTOR Complex 1 (mTORC1) is composed of MTOR, regulatory-associated protein of MTOR (Raptor), mammalian lethal with SEC13 protein 8 (MLST8) and the non-core components PRAS40 and DEPTOR. This complex functions as a nutrient/energy/redox sensor and controls protein synthesis. The activity of mTORC1 is regulated by rapamycin, insulin, growth factors, phosphatidic acid, certain amino acids and their derivatives (e.g., L-leucine and β-hydroxy β-methylbutyric acid), mechanical stimuli, and oxidative stress

Rapamycin inhibits mTORC1, and this appears to provide most of the beneficial effects of the drug (including life-span extension in animal studies). Rapamycin has a more complex effect on mTORC2.

How do amino acids affect mTOR?

This is not fully understood by anyone, but here is a relevant paper, for those interested.

The role of amino acid-induced mammalian target of rapamycin complex 1(mTORC1) signaling ininsulin resistance

Mammalian target of rapamycin (mTOR) controls cell growth and metabolism in response to nutrients, energy, and growth factors. Recent findings have placed the lysosome at the core of mTOR complex 1 (mTORC1) regulation by amino acids. Two parallel pathways, Rag GTPase-Ragulator and Vps34-phospholipase D1 (PLD1), regulate mTOR activation on the lysosome. This review describes the recent advances in understanding amino acid-induced mTOR signaling with a particular focus on the role of mTOR in insulin resistance.

We then discuss how mTORC1 activation by amino acids controls insulin signaling, a key aspect of body metabolism, and how deregulation of mTOR signaling can promote metabolic disease. 

Concluding remarks

Recent findings of new mediators and their regulatory mechanisms have broadened our understanding of amino acid-induced mTOR signaling. In addition to the role of the TSC1-TSC2-Rheb hub in transducing upstream signals from growth factors, stressors and energy to mTOR, the lysosomal regulation of mTOR functions as a platform to connect nutrient signals to the Rheb axis. Furthermore, two parallel pathways of amino acid signaling explain the diverse regulation of mTOR signaling. It is yet to be determined which regulators sense amino acids directly and whether the two pathways require separate amino acid sensing mechanisms. The identification of a direct amino acid sensor will shed light on these uncertainties.

A more integrated understanding of mTOR regulation in amino acid signaling will open the door for new therapeutic approaches for metabolic diseases, especially type 2 diabetes. Already, metformin, an antidiabetic drug, inhibits mTOR in an AMP-activated kinase (AMPK)-independent and Rag-dependent manner,⁶⁴ providing further support for the idea that the regulation of amino acid sensing could be a therapeutic target for diabetes.

How typical is the level of amino acids in autism?

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

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).

  

Conclusion 

For the more common hyperactive pro growth signaling pathway types of autism, histidine should be a good amino acid, whereas for the hypoactive type, that might feature microcephaly, leucine should be a good choice.

Histidine is already used by some people to treat allergy.

Histidine does have numerous other functions and one relates to zinc, so it is suggested that people who supplement histidine add a little zinc. For this reason German histidine supplements thoughtfully all seem to include zinc.

Histidine also has some direct antioxidant effects and has an effect on Superoxide dismutase (SOD).

It is not clear how much histidine would be needed in humans to achieve the mTOR inhibiting effect found in mice.

The RDA for younger teenagers is histidine  850 mg and leucine 2450 mg.  What the therapeutic dose to affect mTOR in humans remains to be seen.

Histidine is also claimed to help ulcers, which is plausible.

For allergy some people are taking 1,500mg of histidine a day.