Mefenamic acid (Ponstan) for some Autism

Caution:-

Ponstan (Mefenamic Acid) contains a warning:-

Caution should be exercised when treating patients suffering from epilepsy.

At lower doses Ponstan is antiepileptic, but at high doses it can have the opposite effect.  This effect depends on the biological origin of the seizures.

In an earlier post I wrote about a paper by Knut Wittkowski who applied statistics to interpret the existing genetic data on autism. 

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

His analysis suggested the early use of Fenamate drugs could potentially reduce the neurological anomalies that develop in autism as the brain develops.  The natural question arose in the comments was to whether it is too late to use Fenamates in later life.

Knut was particularly looking at a handful of commonly affected genes (ANO 2/4/7 & KCNMA1) where defects should partially be remedied by use of fenamates.

I recently received a comment from a South African reader who finds that his children’s autism improves when he gives them Ponstan and he wondered why.  Ponstan (Mefenamic Acid) is a fenamate drug often used in many countries as a pain killer, particularly in young children.

Ponstan is a cheap NSAID-type drug very widely used in some countries and very rarely used in other countries like the US.  It is available without prescription in some English-speaking countries (try a pharmacy in New Zealand, who sell online) and, as Petra has pointed out, it is widely available in Greece.

I did some more digging and was surprised what other potentially very relevant effects Ponstan has.  Ponstan affects GABA_A receptors, where it is a positive allosteric modulator (PAM).  This may be very relevant to many people with autism because we have seen that fine-tuning the response of the sub-units that comprise GABA_A receptors you can potentially improve cognition and also modulate anxiety. 

Anxiety seems to be a core issue in Asperger’s, whereas in Classic Autism, or Strict Definition Autism (SDA) the core issue is often actually cognitive function rather than “autism” as such.

In this post I will bring together the science showing why Ponstan should indeed be helpful in some types of autism.

Professor Ritvo from UCLA read Knut’s paper and also the bumetanide research and suggested that babies could be treated with Ponstan and then, later on, with  Bumetanide.

Autism treatments proposed by clinical studies and human genetics are complementary

I do not think the professor or Knut are aware of Ponstan’s effect on GABA.

The benefits from Ponstan may very well be greater if given to babies at risk of autism, but there does seem to be potential benefit for older children and adults, depending on their type of autism.

Professor Ritvo points out that that Ponstan is safely used in 6 month old babies, so trialing it in children and adults with autism should not be troubling.

Being an NSAID, long term use at high doses may well cause GI side effects.  An open question is the dosage at which Ponstan modulates the calcium activated ion channels that are implicated in some autism and also what dosage affects GABA_A receptors.  It might well be lower than that required for Ponstan’s known ant-inflammatory effects.

Ponstan vs Ibuprofen

Ibuprofen is quite widely used in autism.  Ibuprofen is an NSAID but also a PPAR gamma agonist.  Ponstan is an NSAID but has no effect on PPAR gamma.

Research shows that some types of autism respond to PPAR gamma agonists.

So it is worth trying both Ponstan and Ibuprofen, but for somewhat different reasons.

They are both interesting to deal with autism flare-ups, which seem common.

Other drugs that people use short term, but are used long term in asthma therapy,  are Singulair (Montelukast) and an interesting Japanese drug called Ibudilast.  Singulair is a Western drug for maintenance therapy in asthma.  Ibudilast is widely used in Japan as maintenance therapy in Asthma, but works in a different way.  Ibudilast is being used in clinical trials in the US to treat Multiple Sclerosis.  Singulair is cheap and widely available, Ibudilast is more expensive and available mainly in Japan.

Pre-vaccination Immunomodulation

In spite of there being no publicly acknowledged link between vaccinations and autism secondary to mitochondrial disease (AMD), I read that short term immunomodulation is used prior to vaccination at Johns Hopkins, for some babies.

Singulair is used, as is apparently ibuprofen.  Ponstan and Ibudilast would also likely be protective.   Ponstan might well be the best choice; it lowers fevers better than ibuprofen.

For those open minded people, here is what a former head of the US National Institutes of Health, Bernadine Healy, had to say about the safe vaccination.  Not surprisingly she was another Johns Hopkins trained doctor, as is Hannah Poling’s Neurologist father.

The Vaccines-Autism War: Détente Needed

“Finally, are certain groups of people especially susceptible to side effects from vaccines, and can we identify them? Youngsters like Hannah Poling, for example, who has an underlying mitochondrial disorder and developed a sudden and dramatic case of regressive autism after receiving nine immunizations, later determined to be the precipitating factor. Other children may have a genetic predisposition to autism, a pre-existing neurological condition worsened by vaccines, or an immune system that is sent into overdrive by too many vaccines, and thus they might deserve special care. This approach challenges the notion that every child must be vaccinated for every pathogen on the government's schedule with almost no exception, a policy that means some will be sacrificed so the vast majority benefit.”

So if I was an American running the FDA/CDC I would suggest giving parents the option of paying a couple of dollars for 10 days of Ponstan prior to these megadose vaccinations and a few days afterwards.  No harm or good done in 99.9% of cases, but maybe some good done for the remainder.

The fact the fact that nobody paid any attention to the late Dr Healy on this subject tells you a lot.

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.  KCNMA1encodes 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.

But fenamates also have a potent effect on what seems to be the most dysfunctional receptor in classic autism, the GABAA receptor.

Characterization of the interaction between fenamates and hippocampal neuron GABAA receptors

The fenamate NSAID, mefenamic acid (MFA) prevents convulsions and protects rats from seizure-induced forebrain damage evoked by pilocarpine (Ikonomidou-Turski et al., 1988) and is anti-epileptogenic against pentylenetetrazol (PTZ)-induced seizure activity, but at high doses induces seizures (Wallenstein, 1991). In humans, MFA overdose can lead to convulsions and coma (Balali-Mood et al, 1981; Young et al., 1979; Smolinske et al., 1990). More recent data by Chen and colleagues (1998) have shown that the fenamates, flufenamic, meclofenamic and mefenamic acid, protect chick embryo retinal neurons against ischaemic and excitotoxic (kainate and NMDA) induced neuronal cell death in vitro (Chen et al., 1998a; 1998b). MFA has also been reported to reduce neuronal damage induced by intraventricular amyloid beta peptide (Aβ1-42) and improve learning in rats treated with Aβ1-42 (Joo et al., 2006). The mechanisms underlying these anti-epileptic and neuroprotective effects are not well understood but together suggest that fenamates may influence neuronal excitability through modulation of ligand and/or voltage-gated ion channels. In the present study, therefore, we have investigated this hypothesis by determining the actions of five representative fenamate NSAIDs at the major excitatory and inhibitory ligand-gated ion channels in cultured hippocampal neurons

This study demonstrates for the first time that mefenamic acid and 4 other representatives of the fenamate NSAIDs are highly effective and potent modulators of native hippocampal neuron GABAA receptors. MFA was the most potent and at concentrations equal to or greater than 10 μM was also able to directly activate the GABAA gated chloride channel. A previous study from this laboratory reported that mefenamic acid potentiated recombinant GABAA receptors expressed in HEK-293 cells and in Xenopus laevis oocytes (Halliwell et al., 1999). Together these studies lead to the conclusion that fenamate NSAIDs should now also be considered a robust class of GABAA receptor modulators.

Also demonstrated for the first time here is the direct activation of neuronal GABAA receptors by mefenamic acid. Other allosteric potentiators, including the neuroactive steroids and the depressant barbiturates share this property, with MFA at least equipotent to neurosteroids and significantly more potent than the barbiturates. The mechanism(s) of the direct gating of GABAA receptor chloride channels by MFA requires further investigation using ultra-fast perfusion techniques but may be distinct from that reported for neurosteroids (see, Hosie et al., 2006). Mefenamic acid induced a leftward shift in the GABA dose-response curve consistent with an increase in receptor affinity for the agonist. This is an action observed with other positive allosteric GABAA receptor modulators, including the benzodiazepine agonist, diazepam, the neuroactive steroid, allopregnanolone, and the intravenous anesthetics, pentobarbitone and propofol (e.g. Johnston, 2005). To our knowledge, a unique property of MFA was that it was significantly (F = 10.35; p≤ 0.001) more effective potentiating GABA currents at hyperpolarized holding potentials (especially greater than −60mV). Further experiments are required however to determine the underlying mechanism(s).

The highly effective modulation of GABAA receptors in cultured hippocampal neurons suggests the fenamates may have central actions. Consistent with this hypothesis, mefenamic acid concentrations are 40–80μM in plasma with therapeutic doses (Cryer & Feldman, 1998); fenamates can also cross the blood brain barrier (Houin et al., 1983; Bannwarth et al., 1989) Coyne et al. Page 5 Neurochem Int. Author manuscript; available in PMC 2008 November 1. NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript and in overdose in humans are associated with coma and convulsions (Smolinske et al., 1990). In animal studies, mefenamic acid is anticonvulsant and neuroprotective against seizureinduced forebrain damage in rodents (Ikonomidou-Turski et al., 1988). The present study would suggest that the anticonvulsant effects of fenamates may be related, in part, to their efficacy to potentiate native GABAA receptors in the brain, although a recent study has suggested that activation of M-type K+ channels may contribute to this action (Peretz et al., 2005) Finally, Joo and co-workers (2006) have recently reported that mefenamic acid provided neuroprotection against β-amyloid (Aβ1-42) induced neurodegeneration and attenuated cognitive impairments in this animal model of Alzheimer’s disease. The authors proposed that neuroprotection may have resulted from inhibition of cytochrome c release from mitochondria and reduced caspase-3 activation by mefenamic acid. Clearly it would also be of interest to evaluate the role of GABA receptor modulation in this in vivo model of Alzheimer’s disease. Moreover, considerable evidence has emerged in the last few years indicating that GABA receptor subtypes are involved in distinct neuronal functions and subtype modulators may provide novel pharmacological therapies (Rudolf & Mohler, 2006). Our present data showing that fenamates are highly effective modulators of native GABAA receptors and that mefenamic acid is highly subtype-selective (Halliwell et al., 1999) suggests that further studies of its cognitive and behavioral effects would be of value.

  

Note in the above paper that NSAIDs other than mefenamic acid also modulate GABAA receptors.

Just a couple of months ago a rather complicated paper was published, again showing that NSAIDs modulate GABA_A receptors and showing that this is achieved via the same calcium activated chloride channels (CaCC) referred to by Knut.

NSAIDs modulate GABA-activated currents via Ca²⁺-activated Cl⁻ channels in rat dorsal root ganglion neurons

"Schematic displaying the effects of CaCCs on GABA-activated inward currents and depolarization. GABA activates the GABA_A receptor to open the Cl ⁻ channel and the Cl⁻ efflux induces the depolarization response (inward current) of the membrane of dorsal root ganglion (DRG) neurons. Then, voltage dependent L-type Ca²⁺ channels are activated by the depolarization, and give rise to an increase in intracellular Ca²⁺. CaCCs are activated by an increase in intracellular Ca²⁺ concentration which, in turn, increases the driving force for Cl⁻ efflux. Finally, the synergistic action of the chloride ion efflux through GABA_A receptors and NFA-sensitive CaCCs causes GABA-activated currents or depolarization response in rat DRG neurons."

Note in the complex explanation above the L-type calcium channels, which are already being targeted by Verapamil, in the PolyPill.

Mefenamic Acid and Potassium Channels

We know that Mefenamic acid also affects K_v7.1 (KvLQT1).

A closely related substance called meclofenamic acid is known to act as novel KCNQ2/Q3 channel openers and is seen as having potential for the treatment of neuronal hyper-excitability including epilepsy, migraine, or neuropathic pain.

Meclofenamic Acid and Diclofenac, Novel Templates of KCNQ2/Q3 Potassium Channel Openers, Depress Cortical Neuron Activity and Exhibit Anticonvulsant Properties

The voltage-dependent M-type potassium current (M-current) plays a major role in controlling brain excitability by stabilizing the membrane potential and acting as a brake for neuronal firing. The KCNQ2/Q3 heteromeric channel complex was identified as the molecular correlate of the M-current. Furthermore, the KCNQ2 and KCNQ3 channel  subunits are mutated in families with benign familial neonatal convulsions, a neonatal form of epilepsy. Enhancement of KCNQ2/Q3 potassium currents may provide an important target for antiepileptic drug development. Here, we show that meclofenamic acid (meclofenamate) and diclofenac, two related molecules previously used as anti-inflammatory drugs, act as novel KCNQ2/Q3 channel openers. Extracellular application of meclofenamate (EC50  25 M) and diclofenac (EC50  2.6 M) resulted in the activation of KCNQ2/Q3 K currents, heterologously expressed in Chinese hamster ovary cells. Both openers activated KCNQ2/Q3 channels by causing a hyperpolarizing shift of the voltage activation curve (23 and 15 mV, respectively) and by markedly slowing the deactivation kinetics. The effects of the drugs were stronger on KCNQ2 than on KCNQ3 channel  subunits. In contrast, they did not enhance KCNQ1 K currents. Both openers increased KCNQ2/Q3 current amplitude at physiologically relevant potentials and led to hyperpolarization of the resting membrane potential. In cultured cortical neurons, meclofenamate and diclofenac enhanced the M-current and reduced evoked and spontaneous action potentials, whereas in vivo diclofenac exhibited an anticonvulsant activity (ED50  43 mg/kg). These compounds potentially constitute novel drug templates for the treatment of neuronal hyperexcitability including epilepsy, migraine, or neuropathic pain. Volt

BK channel

KCNMA1encodes the ion channel K_Ca1.1, otherwise known as BK (big potassium). BK channels are implicated not only by Knut’s statistics, but numerous studies ranging from schizophrenia to Fragile X. 

Usually it is a case of too little BK channel activity.

The BK channel is implicated in some epilepsy.

  

Pharmacology

BK channels are pharmacological targets for the treatment of several medical disorders including stroke and overactive bladder. Although pharmaceutical companies have attempted to develop synthetic molecules targeting BK channels, their efforts have proved largely ineffective. For instance, BMS-204352, a molecule developed by Bristol-Myers Squibb, failed to improve clinical outcome in stroke patients compared to placebo. However, BKCa channels are reduced in patients suffering from the Fragile X syndrome and the agonist, BMS-204352, corrects some of the deficits observed in Fmr1 knockout mice, a model of Fragile X syndrome.

BK channels have also been found to be activated by exogenous pollutants and endogenous gasotransmitters carbon monoxide and hydrogen sulphide.

BK channels can be readily inhibited by a range of compounds including tetraethylammonium (TEA), paxilline and iberiotoxin.

BK channel dysfunction and neurological disorders

Achieving a better understanding of BK channel function is important not only for furthering our knowledge of the involvement of these channels in physiological processes, but also for pathophysiological conditions, as has been demonstrated by recent discoveries implicating these channels in neurological disorders. One such disorder is schizophrenia where BK channels are hypothesized to play a role in the etiology of the disease due to the effects of commonly used antipsychotic drugs on enhancing K⁺ conductance [101]. Furthermore, this same study found that the mRNA expression levels of the BK channel were significantly lower in the prefrontal cortex of the schizophrenic group than in the control group [101]. Similarly, autism and mental retardation have been linked to haploinsufficiency of the Slo1 gene and decreased BK channel expression [102].

Two mutations in BK channel genes have been associated with epilepsy. One mutation has been identified on the accessory β3 subunit, which results in an early truncation of the protein and has been significantly correlated in patients with idiopathic generalized epilepsy [103]. The other mutation is located on the Slo1gene, and was identified through genetic screening of a family with generalized epilepsy and paroxysmal dyskinesia [104]. The biophysical properties of this Slo1 mutation indicates enhanced sensitivity to Ca²⁺ and an increased average time that the channel remains open [104–107]. This increased Ca²⁺ sensitivity is dependent on the specific type of β subunit associating with the BK channel [106, 107]. In association with the β3 subunit, the mutation does not alter the Ca²⁺-dependent properties of the channel, but with the β4 subunit the mutation increases the Ca²⁺ sensitivity [105–107]. This is significant considering the relatively high abundance of the β4 subunit compared to the weak distribution of the β3 subunit in the brain [12, 13,15, 106, 107]. It has been proposed that a gain of BK channel function may result in increases in the firing frequency due to rapid repolarization of APs, which allows a quick recovery of Na⁺ channels from inactivation, thereby facilitating the firing of subsequent APs [104]. Supporting this hypothesis, mice null for the β4 subunit showed enhanced Ca²⁺ sensitivity of BK channels, resulting in temporal lobe epilepsy, which was likely due to a shortened duration and increased frequency of APs [108]. An interesting relevance to the mechanisms of BK channel activation as discussed above, the Slo1 mutation associated with epilepsy only alters Ca²⁺ dependent activation originated from the Ca²⁺ binding site in RCK1, but not from the Ca²⁺bowl, by altering the coupling mechanism between Ca²⁺ binding and gate opening [100]. Since Ca²⁺dependent activation originated from the Ca²⁺ binding site in RCK1 is enhanced by membrane depolarization, at the peak of an action potential the binding of Ca²⁺ to the site in RCK1 contributes much more than binding to the Ca²⁺ bowl to activating the channel [84, 109].

Although these associations between specific mutations in BK channel subunits and various neurological disorders have been demonstrated by numerous studies, it is also important to point out certain caveats with these studies, such as genetic linkage between BK channels and different diseases do not necessary show causation as these studies were performed based on correlation between changes in the protein/genetic marker and overall phenotype. Furthermore, studies performed using a mouse model also can fail to indicate what may happen in higher-order species, and this is especially true for BK channels, where certain β subunits are only primate specific [110].

  

Possible role of potassium channel, big K in etiology of schizophrenia.

Schizophrenia (SZ), a common severe mental disorder, affecting about 1% of the world population. However, the etiology of SZ is still largely unknown. It is believed that molecules that are in an association with the etiology and pathology of SZ are neurotransmitters including dopamine, 5-HT and gamma-aminobutyric acid (GABA). But several lines of evidences indicate that potassium large conductance calcium-activated channel, known as BK channel, is likely to be included. BK channel belongs to a group of ion channels that plays an important role in regulating neuronal excitability and transmitter releasing. Its involvement in SZ emerges as a great interest. For example, commonly used neuroleptics, in clinical therapeutic concentrations, alter calcium-activated potassium conductance in central neurons. Diazoxide, a potassium channel opener/activator, showed a significant superiority over haloperidol alone in the treatment of positive and general psychopathology symptoms in SZ. Additionally, estrogen, which regulates the activity of BK channel, modulates dopaminergic D2 receptor and has an antipsychotic-like effect. Therefore, we hypothesize that BK channel may play a role in SZ and those agents, which can target either BK channel functions or its expression may contribute to the therapeutic actions of SZ treatment.

Conclusion

It appears that Ponstan and related substances have some interesting effects that are only now emerging in the research.

People with autism, and indeed schizophrenia, may potentially benefit from Ponstan and for a variety of different reasons.

I think it will take many decades for any conclusive research to be published on this subject, because this is an off-patent generic drug.

As with most NSAIDS, it is simple to trial Ponstan.

Thanks to Knut for the idea, Professor Ritvo for his endorsement of the idea and our reader from South Africa for sharing his positive experience with Ponstan. 

“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.