Immune modulatory treatments for autism spectrum disorder

Need a wizard, or your local doctor?

I was intrigued to come across a recent paper on immune modulatory treatments for autism by a couple of doctors from Massachusetts General Hospital for Children.  The lead author has interests in:

·      Autism spectrum disorders

·      Psychopharmacology

·      Developmental Disabilities

·      Williams syndrome

·      Angelman syndrome

·      Down syndrome

Apparently, he is an internationally-recognized expert in the neurobiology and neuropsychopharmacology of childhood-onset neuropsychiatric disorders including autistic disorder.  Sounds promising, hopefully we will learn something new.

The paper is actually a review of existing drugs, with immunomodulatory properties, that have already been suggested to be repurposed for autism. The abstract was not very insightful, so I have highlighted the final conclusions and listed the drugs, by category, that they thought should be investigated further.

All the drugs have already been covered in this blog and have already been researched in autism.

One important point raised in the conclusion relates to when the drugs are used.  Autism is a progressive condition early in life and there are so-called “critical periods” when the developing brain is highly vulnerable.

For example, Pentoxifylline has been found to be most effective in very young children.  This does not mean do not give it to a teenager with autism, it just means the sooner you treat autism the better the result will be.  This is entirely logical.

Some very clever drugs clearly do not work if given too late, for example Rapamycin analogs used in people with TSC-type autism.

Multiple Critical Periods for Rapamycin Treatment to Correct Structural Defects in Tsc-1-Suppressed Brain

Importantly, each of these developmental abnormalities that are caused by enhanced mTOR pathway has a specific window of opportunity to respond to rapamycin. Namely, dyslamination must be corrected during neurogenesis, and postnatal rapamycin treatment will not correct the cortical malformation. Similarly, exuberant branching of basal dendrites is rectifiable only during the first 2 weeks postnatally while an increase in spine density responds to rapamycin treatment thereafter.  

Back to today’s paper.

Immune modulatory treatments for autism spectrum disorder

The identification of immune dysregulation in at least a subtype ASD has led to the hypothesis that immune modulatory treatments may be effective in treating the core and associated symptoms of ASD. In this article, we discussed how currently FDA-approved medications for ASD have immune modulatory properties.

“Risperidone also inhibited the expression of inflammatory signaling proteins, myelin basic protein isoform 3 (MBP1) and mitogen-activated kinase 1 (MAPK1), in a rat model of MIA. Similarly, aripiprazole has been demonstrated to inhibit expression of IL-6 and TNF-α in cultured primary human peripheral blood mononuclear cells from healthy adult donors.”

We then described emerging treatments for ASD which have been repurposed from nonpsychiatric fields of medicine including metabolic disease, infectious disease, gastroenterology, neurology, and regenerative medicine, all with immune modulatory potential. Although immune modulatory treatments are not currently the standard of care for ASD, remain experimental, and require further research to demonstrate clear safety, tolerability, and efficacy, the early positive results described above warrant further research in the context of IRB-approved clinical trials. Future research is needed to determine whether immune modulatory treatments will affect underlying pathophysiological processes affecting both the behavioral symptoms and the common immune-mediated medical co-morbidities of ASD. Identification of neuroimaging or inflammatory biomarkers that respond to immune modulatory treatment and correlate with treatment response would further support the hypothesis of an immune-mediated subtype of ASD and aid in measuring response to immune modulatory treatments. In addition, it will be important to determine if particular immune modulating treatments are best tolerated and most effective when administered at specific developmental time points across the lifespan of individuals with ASD.

Here are the drugs they listed:-

1.     Metabolic disease

Spironolactone

Pioglitazone

Pentoxifylline

Spironolactone is a cheap potassium sparing diuretic. It has secondary effects that include reducing the level of male hormones and some inflammatory cytokines.

Pioglitazone is drug for type 2 diabetes that improves insulin sensitivity.  It reduces certain inflammatory cytokines making it both an autism therapy and indeed a suggested Covid-19 therapy.

Pentoxifylline is a non-selective phosphodiesterase (PDE) inhibitor, used to treat muscle pain.  PDE inhibitors are very interesting drugs with a great therapeutic potential for the treatment of immune-mediated and inflammatory diseases.  Roflumilast and Ibudilast are PDE4 inhibitors that also may improve some autism.  The limiting side effect can be nausea/vomiting, which can happen with non-selective PDE4 inhibitors.

I did try Spironolactone once; it did not seem to have any effect.  It is a good match for bumetanide because it increases potassium levels.

I do think that Pioglitazone has a helpful effect and there will be another post on that.

PDE inhibitors are used by readers of this blog. Maja is a fan of Pentoxifylline, without any side effects. Roflumilast at a low dose is supposed to raise IQ, but still makes some people want to vomit. The Japanese drug Ibudilast works for some, but nausea is listed as a possible side effect.

2.     Infectious disease

Minocycline

Vancomycin

Suramin

Minocycline is an antibiotic that crosses in to the brain.  It is known to stabilize activated microglia, the brain’s immune cells.  It is also known that tetracycline antibiotics are immunomodulatory.

Vancomycin is an antibiotic used to treat bacterial infections, if taken orally it does not go beyond the gut.  It will reduce the level of certain harmful bacteria including Clostridium difficile.

Suramin is an anti-parasite drug that Dr Naviaux is repurposing for autism, based on his theory of cell danger response.

  

3.     Neurology

Valproic acid

Valproic acid is an anti-epileptic drug.  It also has immunomodulatory and HDAC effects, these effects can both cause autism when taken by a pregnant mother and also improve autism in some people.

Valproic acid can have side effects. Low dose valproic acid seems to work for some people. 

4.     Gastroenterology

Fecal microbiota transplant (FMT)

FMT is currently used to treat recurrent Clostridium difficile infection and may also be of benefit for other GI conditions including IBD, obesity, metabolic syndrome, and functional GI disorders.

Altered gut bacteria (dysbiosis) is a feature of some autism which then impairs brain function.  Reversing the dysbiosis with FMT improves brain function.  

5.     Oncology

Lenalidomide

Romidepsin

  

Lenalidomide is an expensive anti-cancer drug that also has immunomodulatory effects.

Romidepsin is a potent HDAC inhibitor, making it a useful cancer therapy.  HDAC inhibitors are potential autism drugs, but only if given early enough not to miss the critical periods of brain development. 

6.     Pulmonology

N-acetylcysteine

Many people with autism respond well to NAC. You do need a lot of it, because it has a short half-life.

7.     Nutritional medicine and dietary supplements

Omega-3 fatty acids

Vitamin D

Flavonoids

Nutritional supplements can get very expensive.  In hot climates, like Egypt, some dark skinned people cover up and then lack vitamin D.  A lack of vitamin D will make autism worse.

Some people with mild brain disorders do seem to benefit from some omega-3 therapies.

Flavonoids are very good for general health, but seem to lack potency for treating brain disorders.  Quercetin and luteolin do have some benefits. 

8.     Rheumatology

Celecoxib

Corticosteroids

Intravenous immunoglobulin (IVIG)

Celecoxib is a common NSAID that is particularly well tolerated (it affects COX-2 and only marginally COX-1, hence its reduced GI side effects).

NSAIDS are used by many people with autism.

Steroids do improve some people’s autism, but are unsuitable for long term use.  A short course of steroids reduces Covid-19 deaths – a very cost effective therapy.

IVIG is extremely expensive, but it does provide a benefit in some cases. IVIG is used quite often to treat autism in the US, but rarely elsewhere other than for PANS/PANDAS that might occur with autism.

9.     Regenerative medicine

Stem cell therapy

I was surprised they gave stem cell therapy a mention. I think it is still early days for stem cell therapy.

Conclusion

I have observed the ongoing Covid-19 situation with interest and in particular what use has been made of the scientific literature.

There are all sorts of interesting snippets of data. You do not want to be deficient in Zinc or vitamin D, having high cholesterol will make it easier for the virus to enter your cells.  Potassium levels may plummet and blood becomes sticky, so may form dangerous clots. A long list of drugs may be at least partially effective, meaning they speed up recovery and reduce death rates. Polytherapy, meaning taking multiple drugs, is likely to be the best choice for Covid-19.

Potential side effects of some drugs have been grossly exaggerated, as with drugs repurposed for autism.  Even in published research, people cheat and falsify the data. In the case of hydroxychloroquine, the falsified papers were quickly retracted.

The media twist the facts, to suit their narrative, as with autism.  This happens even with Covid-19. Anti-Trump media (CNN, BBC etc) is automatically anti-hydroxychloroquine, and ignores all the published research and the results achieved in countries that widely use it (small countries like China and India). 

Shutting down entire economies when only 5-10% of the population have been infected and hopefully got some immunity, does not look so smart if you are then going to reopen and let young people loose.  They will inevitably catch the virus and then infect everyone else. Permanent lockdown restrictions, if followed by everyone, until a vaccine which everyone actually agreed to take, makes sense and living with the virus makes sense, but anything in between is not going to work. After 3 months without any broad lockdown, and allowing young people to socialize, most people would have had the virus and then those people choosing to shield could safely reemerge. The death rate with the current optimal, inexpensive treatment, as used in India or South Africa is very low, in people who are not frail to start with. Time to make a choice.  Poor people in poor countries cannot afford to keep going into lockdown, they need to eat.

What hope is there for treating a highly heterogeneous condition like autism, if it is not approached entirely rationally and without preconceptions and preconditions?  In a pandemic we see that science does not drive policy and translating science into therapy is highly variable.  The science is there for those who choose to read it.

I frequently see comments from parents who have seen some of the research showing that autism has an inflammatory/auto-immune component.  They ask why this has not been followed up on in the research.  It has been followed up on.  It just has not been acted upon.

Why has it not been acted on?

This missing stage is called “translation”.  Why don’t doctors translate scientific findings into therapy for their patients?

What is common sense to some, is “experimental” to others. “Experimental” is frowned upon in modern medicine, but innovation requires experimentation.

Many people’s severe autism is unique and experimental polytherapy/polypharmacy is their only hope.

The cookie cutter approach is not going to work for autism. 

Thankfully, for many common diseases the cookie cutter approach works just fine.

Do the authors of today’s paper, Dr McDougle and Dr Thom, actually prescribe to their young patients many of the drugs that they have written about?  I doubt it and therein lies the problem.  

Time for that wizard, perhaps? 

A few years ago I did add the following tag line, under the big Epiphany at the top of the page. 

An Alternative Reality for Classic Autism - Based on Today's Science

You can choose a different Autism reality, if you do not like your current one.  I am glad I did. I didn't even need a wizard.  

There are many immuno-modulatory therapies for autism that the Massachusetts doctor duo did not mention, but it is good that they made a start.

Garlic in Autism – Miscreant Microglia? ACE inhibition? or even Nitric Oxide?

Many people avoid garlic because it gives you bad breath, but if you eat enough of it, it can be a potent drug.

There is a substantial amount of research about garlic and general health - it is consistently positive. However, there is an odd resistance to tell people about it.  A good example is this quote from the website of the UK’s National Health Service.

“Studies using high concentrations of garlic extracts have been associated with improved blood circulation, healthier cholesterol levels and lower blood pressure, all of which reduce the risk of cardiovascular disease. However, current evidence does not support the use of garlic supplements to improve health.”

Which sounds like “garlic is really good for you, but don’t eat it”.

Garlic has numerous different modes of action that have a potential health benefit, the best known relate to your heart and circulation, but there are others. 

Garlic and Neurological Conditions with Activated Microglia

There is recent research showing positive effects on the activated microglia.  Activated microglia, the brain’s immune cells, is a feature of autism and other diseases, like Alzheimer’s.

Some people try and treat activated microglia in autism using therapies like:-

·        Minocycline

·        Ibudilast

Some researchers use garlic to try to minimize the damage caused by activated microglia.

They tend to use capsules that contain aged garlic.  It is important not to cook it and there is a difference between fresh garlic, aged garlic and steamed garlic. 

Table 1. Principal Organosulfur Compounds in Commercial Garlic Preparations
Product	Principal Organosulfur Compounds	Delivers allicin-derived compounds?
Fresh garlic cloves	Cysteine sulfoxides (Alliin) γ-glutamylcysteines	Yes, when chopped, crushed, or chewed raw. Minimal, when garlic cloves are cooked before crushing or chopping.
Powdered garlic (tablets)	Cysteine sulfoxides (Alliin) γ-glutamylcysteines	Varies greatly among commercial products. Enteric-coated tablets that pass the USP allicin release test are likely to provide the most.
Steam distilled garlic oil (capsules)	Diallyl disulfide Diallyl trisulfide Allyl methyl trisulfide	Yes
Garlic oil macerate (capsules)	Vinyldithiins Ajoene Diallyl trisulfide	Yes
Aged garlic extract™ (tablets or capsules)	S-Allylcysteine S-Allylmercaptocysteine S-1-Propenylcysteine	Minimal

  

Source: -http://lpi.oregonstate.edu/mic/food-beverages/garlic

  

Benefits Of Garlic Extract May Protect Brain From Inflammation, Diseases Like Alzheimer's

Now, a new study finds that one of these compounds, called FruArg, may protect the brain from age-related disease like dementia and Alzheimer’s.

As a carbohydrate derivative of garlic, there’s a relatively high concentration of FruArg in aged garlic extract (AGE), the authors wrote — AGE is typically sold as supplements. Looking at isolated FruArg’s impact on brain cells, researchers from the University of Missouri found it could protect brain cells from an overexcited immune response caused by environmental factors like pollution and smoking, as well as normal aging, brain injuries, and drinking lots of alcohol.

“Microglia are immune cells in the brain and spinal cord that are the first and main line of defense in the central nervous system,” said lead author Zezong Gu, an associate professor of pathology and anatomical sciences at the university’s School of Medicine. “Unlike other mature brain cells that seldom regenerate themselves, microglial cells respond to inflammation and environmental stresses by multiplying. By massing themselves and migrating toward an injury site, they are able to respond to inflammation and protect other brain cells from destruction.”

But microglia also tread a line between benefiting the body and harming it, protecting only to an extent. A byproduct of their function is nitric oxide, a free radical. And when a lot of microglia are produced, so are nitric oxide molecules, which can lead to oxidative stress and inflammation within the brain and nervous system. As we’ve all heard before, however, antioxidants fight oxidative stress, and in this case, that antioxidant compound is FruArg. 

For their study, Gu and his colleagues applied stress to a cell model of microglial cells and then added FruArg to them once nitric oxide concentrations rose. They found the microglial cells “adapted to the stress by reducing the amount of nitric oxide they produced.” What’s more, FruArg also promoted the production of antioxidants, which then went on to protect and heal other brain cells. “This helps us understand how garlic benefits the brain by making it more resilient to the stress and inflammation associated with neurological diseases and aging,” Gu said. 

Full study:- 

Proteomic analysis of the effects of aged garlic extract and its FruArg component on lipopolysaccharide-induced neuroinflammatory response in microglial cells.

Collectively, these results suggest that AGE and FruArg attenuate neuroinflammatory responses and promote resilience in LPS-activated BV-2 cells by suppressing NO production and by regulating expression of multiple protein targets associated with oxidative stress. 

Effects of aged garlic (AGE) extract and FruArg on gene expression and signaling pathways in lipopolysaccharide-activated microglial cells 

These effects could be modulated by treatment with both AGE and FruArg. These findings suggests that AGE and FruArg are capable of alleviating oxidative stress and neuroinflammatory responses stimulated by LPS in BV-2 cells.

  

Evaluating the Anti-Neuroinflammatory Capacity of Raw and Steamed Garlic as Well as Five Organosulfur Compounds

Abstract

: The anti-neuroinflammatory capacities of raw and steamed garlic extracts as well as five organosulfur compounds (OSCs) were examined in lipopolysaccharide (LPS)-stimulated BV2 microglia. According to those results, steaming pretreatment blocked the formation of alliinase-catalyzed OSCs such as allicin and diallyl trisulfide (DATS) in crushed garlic. Raw garlic, but not steamed garlic, dose-dependently attenuated the production of LPS-induced nitric oxide (NO), interleukin-1β (IL-1β), tumor necrosis factor (TNF)-α, and monocyte chemoattractant protein-1 (MCP-1). DATS and diallyl disulfide at 200 and 400 μM, respectively, displayed significant anti-neuroinflammatory activity. Meanwhile, even at 1 mM, diallyl sulfide, S-allyl cysteine and alliin did not display such activity. Inhibition of nuclear factor-κB activation was the mechanism underlying this protective effect of raw garlic and DATS. Analysis results indicated that the anti-neuroinflammatory capacity of raw garlic is due to the alliin-derived OSCs. Importantly, DATS is a highly promising therapeutic candidate for treating inflammation-related neurodegenerative diseases.

As expected, raw garlic extract inhibited NO, proinflammatory cytokine, and chemokine production by through suppression of NF-κB activation in LPS-activated BV2 microglia; it also had a potent anti-neuroinflammatory capacity. Additionally, steaming pretreatment abolished both the anti-neuroinflammatory capacity and alliin-derived OSCs formation of garlic simultaneously. In sum, this study demonstrates that alliinase catalysis and chemical transformation are essential for the formation of active OSCs, which are responsible for the anti-neuroinflammatory capacity of garlic. Based on above, it is suggested that consumers to crush or cut raw garlic before cooking in order to obtain more health benefits of garlic. As one of the most potent anti-neuroinflammatory components of garlic, DATS is highly promising for use as a dietary agent to prevent inflammation-related neurodegenerative disease. 

Garlic as an ACE inhibitor 

We saw in a recent post how too much angiotensin II is likely a problem in schizophrenia and some autism.  The biomarker of those affected would be high levels of IL-17a. 

Targeting Angiotensin in Schizophrenia and Some Autism

There are numerous references in the literature to garlic being an ACE inhibitor, which will reduce the level of angiotensin II and hence IL-17 and IL-17a. 

Garlic extract reduces serum angiotensin converting enzyme (ACE) activity in nondiabetic and streptozotocin-diabetic rats. 

Although garlic extract administration had no significant effect on serum glucose, it significantly strongly decreased the serum ACE activity. ACE activity was higher in diabetic than nondiabetic rats, but in diabetic animals treated with garlic extract, the elevation of ACE activity did not occur. These results suggest that garlic extract might have value as ACE inhibitor to prevent some vascular complications of diabetes mellitus.

So perhaps some people with autism, who respond to garlic are actually not feeling the microglia effect, but actually the angiotensin II reducing effect. 

Potent activation of nitric oxide synthase by garlic: a basis for its therapeutic applications. 

Activation of calcium-dependent nitric oxide synthase and the subsequent production of nitric oxide is probably the most novel mechanism yet claimed by which garlic can exert its therapeutic properties.

   

Conclusion  

Garlic has numerous health benefits and different types of processing lead to very different chemical compositions.  So it does depend how you take your garlic.

Does any type of garlic provide a benefit in any type of autism? 

For one reader fresh garlic is effective in treating autism, whereas aged garlic is not; this is not what she expected. This would of course suggest something about its mode of action. 

Perhaps some people are actually benefiting from a reduction in angiotensin II.  Or maybe it is production of nitric oxide?

There are actually other natural ACE inhibitors that you might be using by accident.

People trying to make tasty drinkable sulforaphane, using the Australian mixture of broccoli and pomegranate powders, are actually also making an ACE inhibitor.  

Effect of pomegranate juice on Angiotensin II-induced hypertension in diabetic wistarrats

The results suggest that the PJ extract could prevent the development of high blood pressure induced by Ang II in diabetic rats probably by combating the oxidative stress induced by diabetes and Ang II and by inhibiting ACE activity.

Pharmacological review on Natural ACE inhibitors 

All we can say is some people with autism respond to specific types of garlic, but nobody can be sure what the mode of action is; there are several possible credible explanations.  

“Autism treatments proposed by clinical studies and human genetics are complementary” & the NSAID Ponstan as a Novel Autism Therapy

Today’s post was not my idea at all, it was the author of one of the papers who has drawn my attention to the subject.

Genetic studies are complicated and are not the sort of thing I would have chosen to read, let alone write about, before starting this blog. 

The optimal time to initiate pharmacological 

intervention in Autism?

However, much of the complex subject matter has now already been covered, step by step, in earlier posts. Regular readers should not feel put off.

It is perhaps easier to think about ion channel dysfunctions, or channelopathies.  Some of the key genetic dysfunctions produce these channelopathies.  There are many posts in this blog about channelopathies, partly because many therapies already exist to treat them.

Then we have the complex signaling pathways which are often the subject of cancer research, but we have seen that certain ones like RAS and PTEN are key to conditions like some autism and some MR/ID.

So it is not a big leap therefore to consider the findings of a statistical reassessment of the existing genome-wide association studies (GWAS).  As is often the case in medical science, it is the acronyms/abbreviations, like GWAS, that make it look more complex than it really is.

If you only ever read one paper about the genetics of autism, I suggest you make it this one.

Fortunately, the conclusion from the genetic study really fits nicely with the clinical studies reviewed on this blog and even my own first-hand experience of investigating and treating my n=1 case of autism.

Knut, the Biometrician

It was Knut who left a brief comment on this blog and, after a little digging, I was very surprised how much a statistician/biometrician could figure out about autism, from re-analyzing the existing genome-wide association studies (GWAS).

I think the Simons Foundation could save themselves a decade or two by giving him a call.

The Research

For those wanting the science-lite version, there is a short article reviewing the research in lay terms:-

Biostatistics provides clues to understanding autism: an interview with Dr Knut M. Wittkowski

“Hence, modulation of ion channels in children at the age of about 12 months, when the first symptoms of autism can be detected, may prevent progression to the more severe end of the spectrum.” .

The actual research paper is here:-

You may find it heavy going and I have highlighted some key parts.

A novel computational biostatistics approach implies impaired dephosphorylationof growth factor receptors as associated with severity of autism

  

“Despite evidence for a likely involvement of de novo and environmental or epigenetic risk factors, including maternal antibodies or stress during pregnancy  and paternal age, we contend that coding variations contribute substantially to the heritability of ASD and can be successfully detected and assembled into connected pathways with GWAS—if the experimental design, the primary outcome, the statistical methods used, and the decision rules applied were better targeted toward the particulars of non-randomized studies of common diseases.”

The data comes from the Autism Genome Project (AGP), and there are two sets of data AGPI and AGPPII.

The third data set is for Childhood Absence Epilepsy (CAE)

What I would call Classic Autism, others call severe autism or autistic disorder; Knut calls it Strict Definition Autism (SDA).  HFA is high functioning autism, much of which is Asperger’s Syndrome.

“Study design We aimed at risk factors specific to strict definition autism (SDA) by comparing case subpopulations meeting the definition of SDA and milder cases with ASD (excluding SDA), for which we here use the term ‘highfunctioning autism’ (HFA). To reduce variance, we included only subjects of European ancestry genotyped on the more frequently used platform in either stage. In AGP II, we also excluded female cases because of confounding between chip platform and disease severity. The total number of subjects included (m: male/f: female) was 547/98 (SDA) and 358/68 (HFA) in AGP I and 375 (SDA) and 201 (HFA) in AGP II.

Overall, the results (see Supplementary Figure 1 for a Manhattan plot) are highly consistent with previously proposed aspects of the etiology of ASD. The clusters of genes implicated in both of the independent stages (Figure 2a/b) consistently overlap with our published CAE results (Figure 2c), confirming the involvement of ion channels (top right) and signaling downstream of RAS (bottom left), with two noticeable additional gene clusters in ASD. Both stages implicate several genes involved in deactivation of growth factor (GF) receptors (Figure 2a/b, top left) as ASD-specific risk factors and chloride (Cl − ) signaling, either through Ca2+ activated Cl− channels

Click to enlarge the figure 

A new term is PTPR (protein tyrosine phosphatases receptor), just to confuse us it is also called RPTP.

Receptor Protein Tyrosine Phosphatases in Nervous System Development

 

For example, the receptor protein tyrosine phosphatases gamma (PTPRG) and zeta (PTPRZ) are expressed primarily in the nervous system and mediate cell adhesion and signaling events during development.

In an earlier post I highlighted the numerous dysfunctions in growth factors (GF) in autism.  Knut is highlighting here the effect of PTPR on growth factors.  Later it is suggested that this cascade of GF dysfunctions could be halted, pharmacologically if it was identified very early.  But, as Courchesne from UC San Diego noted, by the time people have been identified as having autism, around three years old, the accelerated brain growth has already run its course.

You would need to intervene around one year old.

Broad evidence for involvement of PTPRs One of the most striking observations is the involvement of at least five PTPRs in ASD (Figure 2, 10 o’clock position). PTPRs (Table 1e) regulate GF signaling through reversible protein tyrosine dephosphorylation.72 PTPRT (90th/20th, 8.57) was implicated in ASD by a deletion73 (Table S2 AU018704) and a somatic mutation

It was my post pondering the reasons for the positive effect of potassium supplementation that drew Knut’s attention to this blog.  Now we move on to Knut’s ideas on potassium and chloride channels.

K+ and Cl− ion channels as drug targets

Aside from PTPRs (Figure 2, 10 o’clock) as a risk factor for protracted GF signaling, our results suggest a second functional cluster of genes, involved in Cl− transport and signaling, as specific to ASD (Table 1f). In AGP I, the CaCCs ANO4 and ANO7 scored 1st and 70th, respectively. In AGP II, the lysosome membrane H+ /Cl- exchange transporter CLCN7 scored 21st, followed by CAMK2A, which regulates ion channels, including anoctamins82 (55th), and LRRC7 (densin-180), which regulates CAMK2A83 (Figure 2a/b, 2 o’clock). The role of the anoctamins in pathophysiology is not well understood, except that CaCC activity in some neurons is predicted to be excitatory84 and to have a role in neuropathic pain or nerve regeneration. More recently, CaCCs have also been suggested as involved in ‘neurite (re)growth’. Finally, we compared the HFA and SDA cases as separate groups against all parental controls in the larger AGP I population. Overall, the level of significance is lower and the enrichment is less pronounced, especially for the SDA cases (Supplementary Figure 9), as expected when cases and some controls are related. For the HFA cases (Figure 4, and Supplementary Figure 8), however, a second anoctamin, ANO2, located on the other arm of chromosome 12, competes with ANO4 (Figure 1, left), for the most significant gene among the result. Hence, drugs targeting anoctamins might have broader benefits for the treatment of ASD than in preventing progression to more severe forms of autism. ANO2 and ANO6 are associated with panic disorder and major depressive disorder, respectively. ANO3, ANO4, ANO8 and ANO10, but not ANO1, are also expressed in neuronal tissue.86 As ‘druggable channels’, anoctamins ‘may be ideal pharmacological targets to control physiological function or to correct defects in diseases’.  Few drugs, however, target individual anoctamins or even exclusively CaCCs. Cl− channel blockers such as fenamates, for instance, may decrease neuronal excitability primarily by activating Ca2+-dependent outward rectifying K+ channels.

Here is a follow-up paper with consideration of the possible next steps.

Early Pharmacological Intervention in Autism: Wide-Locus GWAS Leading to Novel Treatment Options

Gene gene environment behavior development interaction at the core of autism:

Here, we combine a recent wide-locus approach with novel decision strategies fine-tuned to GWAS. With these methodological advances, mechanistically related clusters of genes and novel treatment options, including prevention of more severe forms of ASD, can now be suggested from studies of a few hundred narrowly defined cases only.

(Nonsyndromic) autism starts with largely unknown prenatal events (♂: age, ♀: virus/stress ...)

• Mutations in growth factor regulators (PTPRs) lead to neuronal overgrowth (brain sizes).

• Mutations in K+/Cl− channels cause Ca2+ mediated over excitation of neurons (“intense world”).

• Stressful environments (urbanization) contribute to epistatic interaction (increasing prevalence).

• This GGE interaction causes “migraine-like” experiences during the “stranger anxiety” period where children learn verbal/social skills, leading to behavioral maladaptation (“tune-out”).

• The lack of verbal/social stimuli causes “patches of disorganization” (Stoner 2014, NEJM) as a form of developmental maladaptation when underutilized brain areas are permanently “pruned”. The PTPRs point to a short window of opportunity (WoO) for pharmacological intervention:

• Treatment has to begin as early as possible, while neurons are still growing (12 months of age. Broad support for the proposed unifying etiology and the 2nd year of life as the WoO:

• Regression (“loss of language”) seen in some children >12 mos of age.

• “Patches of disorganization” in >2 yr old brains.

• Romanian orphans developed “quasi-autism” when placed into foster care at >24 mos of age. 

• Hearing impairment leading to intellectual disability when diagnosed >24 mos of age.

 A rational drug target: treating either of two epistatic risk factors suffices:

• Blocking growth factors (Gleevac, ...) is unacceptable in children merely at risk of ASD.

• Ion channel modulators have been used in small children for arthritis and seizures.

Here is a response to Knut’s first paper from a professor at the UCLA medical school who suggests the combination of the specific NSAID and bumetanide. 

The professor would better understand the mechanism of action of bumetanide in autism if he read Ben Ari’s research more thoroughly, or even this blog.

  

Autism treatments proposed byclinical studies and human genetics are complementary

  

The article by Wittkowski et al.¹ reports results of human genetic studies that suggest that a nonsteroidal anti-inflammatory drug (NSAID) given for a few months from the time of the first symptoms might help some children who are at risk of developing more severe forms of atrial septal defect.

While the authors mention the recent article by Lemonnier et al.,² which reported that a clinical study of the diuretic Bumetanide was partially effective in children with milder forms of autism, they seem to have overlooked that these two treatments may well be complementary, leading to sequential interventions, each targeting specific risks related to well-defined stages in the development of brain and social interactions.

Since abnormal brain development in autistic disorder goes through different stages from infancy to childhood, targeting different developmental stages with different treatment interventions may well be necessary to foster continued normalization of brain growth.

Bumetanide is known to block inward chloride transporters, yet the relation of this mechanism to the etiology of autism is unknown. Wittkowski et al. identified mutations in calcium-activated (outward) chloride channels as associated with autistic disorder, suggesting loss-of-function mutations in anoctamins as one of the risk factors for autism. This provides a testable hypothesis for the mechanism by which Bumetanide alleviates symptoms of autism. For example, mouse models could test whether Bumetanide ameliorates a stress-induced phenotype caused by a knockout/down in ANO2 and/or ANO4.

A second cluster of genes identified receptor protein tyrosine phosphatases, which downregulate growth factors. These findings support the notion that successful treatment should start as early as possible,³ while neuronal development still takes place.

The rationale for combining these two treatments rests on the fact that Bumetanide is contraindicated in infancy because it is known to interfere with neuronal development when used long term. In contrast, the NSAID proposed in the second study has been given for decades to children with juvenile idiopathic arthritis from 6 months of age on, with no adverse effects on brain development. It is known to modulate chloride channels (see above) as well as potassium channels.⁴

In conclusion, I wish to extend their hypothesis based on the synergy of the two treatment approaches: (1) early treatment with NSAID can reduce early maladaptive behaviors that cause abnormal pruning of neurons in the cortical areas; (2) these children could subsequently benefit from Bumetanide, which would compensate for the primary ion channel defect, but could not reverse the secondary effect of abnormal pruning.

This hypothesis allows for a novel two-way interaction between behavior and molecular events. Traditionally, one assumes that molecular events determine behavior. The new hypothesis, based on human genetics, also allows for symptoms (such as the absence of social interactions, delayed speech onset and language development) during certain sensitive periods to change molecular events (pruning of neurons in areas required for normal development).

Therapeutic implications from the genetic analysis

Some of the therapies that Knut is proposing, based on the genetic analysis, have already been reviewed in this blog.  Some have not.  A few therapeutic ideas in this blog actually target genes Knut has identified, but not highlighted a therapy.

I will just review the drugs and genes that the above study highlights.

Benzodiazepines

Low dose clonazepam fits in this category.  We have the work of Professor Catterall to support its use.  At higher doses, benzodiazepines have different effects but use is associated with various troubling side effects.

Bumetanide

Bumetanide is at the core of my suggested therapy for classic autism or what Knut calls SDA (strict definition autism).  We have Ben-Ari to thank for this

Fenamates (ANO 2/4/7 & KCNMA1)

Here Knut is trying to target the ion channels expressed by the genes ANO 2/4/7 & KCNMA1. 

·        ANO 2/4/7 are calcium activated chloride channels. (CACCs)

·        KCNMA1 is a calcium activated potassium channel.  KCNMA1 encodes the ion channel K_Ca1.1, otherwise known as BK (big potassium).  This was the subject of post that I never got round to publishing.

  

Fenamates are an important group of clinically used non-steroidal anti-inflammatory drugs (NSAIDs), but they have other effects beyond being anti-inflammatory.  They act as CaCC inhibitors and also stimulate BKCa channel activity.

  

Fenamates stimulate BKCachannel osteoblast-like MG-63 cells activity in the human.

 “The fenamates can stimulate BKCa channel activity in a manner that seems to be independent of the action of these drugs on the prostaglandin pathway”

Molecular and functional significance of Ca2+-activated Cl− channels in pulmonary arterial smooth muscle

“Of this “first generation” of CaCC inhibitors, NFA (a fenamate called niflumic acid)  is the most potent blocker of these channels and the compound most frequently used to investigate the physiological role of CaCCs”

Choice of Fenamate

There are several fenamate-type NSAIDs, but one is a very well used generic drug, Mefenamic acid known as Ponstan, Ponalar, Ponstyl, Ponstel and other generic names.  It is even available as a syrup for children.

 It is not available in all countries.

Gabapentin

Gabapentin is used primarily to treat seizures and neuropathic pain. It is also commonly prescribed for many off-label uses, such as treatment of anxiety disorders, insomnia, and bipolar disorder.

Some people with autism are prescribed Gabapentin.  Some people suffer side effects and others do not.

If you have a dysfunction of voltage operated calcium channels, Gabapentin should help.

Memantine

This is all about modifying NMDA receptors.  Memantine is but one method.

http://epiphanyasd.blogspot.rs/2015/06/altered-homeostasis-in-autism-cl-k-ca2.html

Minocycline

Minocycline is an antibiotic with several little known extra properties.  In autism, we looked at its ability to reduce microglial activation and so improve autism.  A clinical trial showed that it did not help autism.

Minocycline also affects MMP-9.  MMP-9 is an enzyme found to be associated with numerous pathological processes, including cancer, immunologic and cardiovascular diseases.

High MMP-9 activity levels in fragile X syndrome are lowered by minocycline.

 “ The results of this study suggest that, in humans, activity levels of MMP-9 are lowered by minocycline and that, in some cases, changes in MMP-9 activity are positively associated with improvement based on clinical measures.”

So if you are treating a case of Fragile-X, or partial "Fragile-X-like" autism, better take note.

Rapamycin

Rapamycin and mTOR was the subject of the following post:

mTOR – Indirect inhibition, the Holy Grail for Life Extension and Perhaps Some Autism

Both too much and too little mTOR can occur in autism.

Conclusion

My conclusion is probably different to yours.

For me, it seems that all the pieces really are fitting together and so this blog on the cause and treatment of classic autism will eventually cover the current scientific knowledge, in its entirety.  No complex areas are off limits, because in the end they are not as complex as they seem, when you lift the veil of jargon and acronyms.

From the all-important therapeutic perspective, new insights from today’s post are:-

·        Those with a dysfunction of voltage operated calcium channels might want to give Gabapentin (Neurontin) a try.

·        The fenamate-type NSAID mefenamic acid,  widely known as Ponstan, really should be tested, either at home, or in a clinical trial.

This statistical analysis is based on “all autism”, so any one person would be highly unlikely to have all the mentioned dysfunctions.  These are the most common genetic dysfunctions and many can both hypo and hyper, as in the case of NMDA dysfunctions and indeed mTOR. 

In Knut’s chart, I would add a green line pointing to RAS and PTEN with the word Atorvastatin.  Baclofen would point to the growth factors.  Verapamil would point in multiple places.

The motto of University of Tübingen, where Knut originally comes from, is Attempto !  The Latin for "I dare".

This might be a useful motto for readers of this blog, and also a good tittle for a book on treating autism.