Treating KCC2 Down-Regulation in Autism, Rett/Down Syndromes, Epilepsy and Neuronal Trauma ?

In this composite image, a human nerve cell derived from a patient with Rett syndrome shows significantly decreased levels of KCC2 compared to a control cell.  This will be equally true of about 50% people with classic autism, people with Down syndrome, many with TBI and many with epilepsy

In a recent post I highlighted an idea from the epilepsy research to treat a common phenomenon also found in much classic autism.  Neurons are in an immature state with too much intracellular chloride, the transporter that brings it in, called NKCC1, is over-expressed and the one that takes it out, KCC2, is under-expressed.  The net result is high levels of intracellular chloride and this leaves the brain in an over-excited state (GABA working in reverse) reducing cognitive function and with a reduced threshold to seizures.

The epilepsy research noted that increased BDNF is one factor that down regulates KCC2, which would have taken chloride out of the cells.  So it was suggested to block BDNF, or something closely related called trkB.

Unfortunately there is no easy way to this.  But I did some more digging and found various other ways to upregulate KCC2.

There is indeed a clever safe way that may achieve this and it is a therapy that I have already suggested for other reasons, intranasal insulin.

BDNF is a neurotrophin and other neurothrophins also have the ability to regulate KCC2. IGF-1 is another such neurotrophin and we even have very recent experimental data showing its effect on KCC2.

Regular readers will know that several trials with IGF-1, or analogs thereof, are underway.

I actually am rather biased against IGF-1 as a therapy, since in my son’s case the level of IGF-1 in blood is already high.  So I do not want to inject him with IGF-1 or even give him an oral analog.

However by using intranasal insulin the effect would be just within the CNS and insulin binds at the same receptors as IGF-1. So if IGF-1 upregulates KCC2 so will insulin.

We know from extensive existing trial data and direct feedback from one researcher that intranasal insulin is well tolerated and has no effect outside the CNS.

So rather to my surprise there seems to be a safe, cheap way to treat KCC2 down-regulation and this would also be applicable in epilepsy, traumatic brain injury (TBI) and any other condition involving immature neurons or neuronal trauma. 

The Science

There is a very thorough recent review paper that looks at all the ways that KCC2 expression is regulated.

Current view on the functional regulation of the neuronal K⁺-Cl⁻ cotransporter KCC2

The epilepsy researchers consider trkB, top left in the figure below.  But just next to it is IGFR which can be activated by both insulin and IGF-1.

In Rett syndrome they are already using IGF-1 to modulate KCC2.  The research is done at Penn State.

As you can see in the figure the mechanism for IGF-1 and insulin is not the same as BNDF/trkb, but Penn State have already shown that IGF-1 works in vitro.

We saw in early posts regarding intranasal insulin that this was a safe way to deliver insulin to the brain without effects in the rest of the body.

So we know it is safe and in theory it should achieve the same thing that the Penn State researchers are trying to achieve.

Signaling pathways controlling KCC2 function. The regulation of KCC2 activity is mediated by many proteins including kinases and phosphatases. It affects either the steady state protein expression at the plasma membrane or the KCC2 protein recycling. All the different pathways are explained and discussed in the main text. The schematic drawings of KCC2 as well as other membrane molecules do not reflect their oligomeric structure. GRFα2, GDNF family receptor α2; BDNF, Brain-derived neurotrophic factor; TrKB, Tropomyosin receptor kinase B; Insulin, Insulin-like growth factor 1 (IGF-1); IGFR, Insulin-like growth factor 1 receptor; mGluR1, Group I metabotropic glutamate receptor; 5-HT-2A, 5-hydroxytryptamine (5-HT) type 2A receptor; mAChR, Muscarinic acetylcholine receptor; NMDAR, N-methyl-D-aspartate receptor; mZnR, Metabotropic zinc-sensing receptor (mZnR); GPR39, G-protein-coupled receptor (GPR39); ERK-1,2, Extracellular signal-regulated kinases 1, 2; PKC, Protein kinase C; Src-TK, cytosolic Scr tyrosine kinase; WNKs1–4, with-no-lysine [K] kinase 1–4; SPAK, Ste20p-related proline/alanine-rich kinase; OSR1, oxidative stress-responsive kinase -1; Tph, Tyrosine phosphatase; PP1, protein phosphatase 1; Egr4, Early growth response transcription factor 4; USF 1/2, Upstream stimulating factor 1, 2.

The Penn State research on using IGF-1 to increase KCC2 in Rett Syndrome

Discovery of a new drug target could lead to novel treatment for severe autism

The researchers also showed that treating diseased nerve cells with insulin-like growth factor 1 (IGF1) elevated the level of KCC2 and corrected the function of the GABA neurotransmitter. IGF1 is a molecule that has been shown to alleviate symptoms in a mouse model of Rett Syndrome and is the subject of an ongoing phase-2 clinical trial for the treatment of the disease in humans.

"The finding that IGF1 can rescue the impaired KCC2 level in Rett neurons is important not only because it provides an explanation for the action of IGF1," said Xin Tang, a graduate student in Chen's Lab and the first-listed author of the paper, "but also because it opens the possibility of finding more small molecules that can act on KCC2 to treat Rett syndrome and other autism spectrum disorders."

More Melatonin?

As Agnieszka pointed out in the previous post it appears that extremely high doses of melatonin can increase KCC2 in traumatic brain injury (TBI). In this example BDNF was increased by the therapy, so I think TBI may be a specific case.  In most autism BDNF starts out elevated and in epilepsy, seizures are known to increase BDNF and that process is seen as down regulating KCC2 expression.  So in much autism and epilepsy you want less BDNF.

Melatonin attenuates neuronal apoptosis through up-regulation of K+ -Cl- cotransporter KCC2 expression following traumatic brain injury in rats

Compared with the vehicle group, melatonin treatment altered the down-regulation of KCC2 expression in both mRNA and protein levels after TBI. Also, melatonin treatment increased the protein levels of brain-derived neurotrophic factor (BDNF) and phosphorylated extracellular signal-regulated kinase (p-ERK). Simultaneously, melatonin administration ameliorated cortical neuronal apoptosis, reduced brain edema, and attenuated neurological deficits after TBI. In conclusion, our findings suggested that melatonin restores KCC2 expression, inhibits neuronal apoptosis and attenuates secondary brain injury after TBI, partially through activation of BDNF/ERK pathway.

More Science

There is plenty more science on this subject.

It is suggested that in addition to IGF-1/insulin it may be necessary to involve Protein tyrosine kinase (PTK).

Insulin-Like Growth Factor 1 and a Cytosolic Tyrosine Kinase Activate Chloride Outward Transport during Maturation of Hippocampal Neurons

Protein tyrosine kinase (PTK) phosphorylation is considered a key biochemical event in numerous cellular processes, including proliferation, growth, and differentiation, and has also been implicated in synaptogenesis. Protein tyrosine kinases are subdivided into the cytosolic nonreceptor family and the transmembrane growth factor receptor family, which includes receptors for insulin and insulin-like growth factor (IGF-1). The maturation of postsynaptic inhibition may require both a cytoplasmic PTK, which increases GABA_A receptor-mediated currents, and insulin, which was shown to induce a rapid translocation of GABA_A receptors from intracellular compartments to the plasma membrane. KCC2 is also known to have a C-terminal PTK consensus site. Therefore, the maturation of postsynaptic inhibition may, in addition to other mechanisms, also involve the effects of PTK and insulin acting on KCC2.

Development and regulation of chloride homeostasis in the central nervous system

Conclusion

I would infer from all this science that intranasal insulin is likely to increase KCC2 expression in the brain, certainly worthy of investigation.

Protein tyrosine kinase (PTK) phosphorylation is considered a key biochemical event in numerous cellular processes.  This might be a limiting factor on the effectiveness of insulin in raising KCC2.  This would then add yet more complexity.

Protein kinases are enzymes that add a phosphate(PO₄) group to a protein, and can modulate its function.  A protein kinase inhibitor is a type of enzyme inhibitor that blocks the action of one or more protein kinases.

Abnormal protein tyrosine kinases (PTKs) cause many human leukaemias, so there is research into PTK inhibitors (PTK-Is).

As we know from Abha Chauhan’s mammoth book, oxidative stress controls the activities of PTK.

Longitude, Latitude & Epilepsy in Autism

It is not always easy to decide which subjects to study, never mind if you have autism.

For Monty, aged 12 with autism, it has been me choosing what he studies.  At the beginning it was rather overwhelming for his 1:1 assistant, because there was so much to learn and never enough time.  It takes years to learn very simple things that typical kids just pick up naturally.

One big change after three and half years of Polypill use, is that Monty follows the standard academic curriculum, albeit for kids two years his junior.

An excellent but not very user friendly curriculum/skill list is in a book called ABLLS (assessment of basic language and learning skills).  It is both a curriculum and an assessment tool.  It covers all the very basic skills that kids need as a foundation for future learning.

We were working from this list of simple skills for four years, until the age of eight.  These are skills most kids effortlessly pick up in the first three or four years of life.

After you have mastered those simple skills what do you teach next to someone with classic autism?

I did my research and concluded the generally accepted answer is “not much”.

One phrase I still recall was a mother writing “our kids don’t need to learn longitude and latitude”, because this is going to go way over their heads.

It seems that for kids entirely non-verbal at three, about 10% have some maturational dysfunction that self-corrects by six, leaving just minor tics or perhaps mild "quirky" autism. Most of the remaining 90% end up "graduating" high school with an academic level of a four to seven year old.  A small number do better.  

A few years after ABLLS and Monty has mastered X,Y coordinates, even using negative numbers and identifying objects using Northwest, Southeast etc.

Regular readers will be aware that Monty’s recent academic development did not happen spontaneously, nor through ABA, it came from pharmacotherapy (drugs) and is reversible (hopefully not entirely).

Burden of proof

In spite of all this change it would be hard to prove what has caused it. Fortunately I do not need to.

Monty is still autistic, just less so and is now educable. That is a really big deal to me, but not to others. 

If you could convert 100% of kids with autism into outgoing, talkative, social, intelligent, typical kids then people would take note.  No therapy will ever deliver this. Just to confuse the issue, 10% will indeed "recover" without any intervention at all, which then is used to justify all kinds of interventions that those people used.

Have I measured Monty’s IQ?  No I have not.  A lady from California asked me why not, because over there they have excellent autism services, even assisted employment and sheltered housing but it is rationed based on things including IQ. 

One doctor reader of this blog suggested that some of the drug interventions in this blog will also reduce the development of seizures and therefore reduce the rate of premature death in autism; “surely we should tell people about this”.  I had a sense of déjà vu.

It is clear that in treating the excitatory/inhibitory imbalance that underlies much autism and also treating other channelopathies, you should also be avoiding some of the neuronal hyper-excitability that is epilepsy.

So treating autism should reduce death from seizures that reduce life expectancy in severe autism to just 40 years old.

This is all true and a year or so back I did suggest this to the Bumetanide researchers.  There was little interest and some skepticism. 

In fact there is a great deal of epilepsy research and some does indeed overlap with autism research.  One key area is Cation Chloride Cotransporters (CCCs), where the same type of immature neurons found in autism are found in epilepsy. Another is elevated BDNF (brain-derived neurotropic factor); in epilepsy, seizures trigger an increase in BDNF which then reduces expression of KCC2 which then shifts neurons further towards immature (high intra-cellular chloride) worsening the excitatory/inhibitory imbalance and making the next seizure more likely.  A clever idea we can borrow from the under-utilized epilepsy research is to consider blocking BDNF, or trkB, as a means of increasing KCC2 expression.  This could be a useful adjunct therapy to bumetanide, which blocks NKCC1. We want less NKCC1 but more KCC2, to give lower levels of chloride inside the cells and then neurons can fire when they are supposed to.

It takes decades for research findings, like those in the above paragraph, to be translated across into therapies.

If you, or particularly a researcher, make a statement that is controversial and not backed by a big stack of evidence (based on human trials, not mouse trials) nobody is going to believe you.  Worse still, the next time you make a claim, they will be even less likely to believe you.

So better under-promise but over deliver.  Start finally treating some autism and then watch in the next thirty years that epilepsy incidence falls and along with it SUDEP (Sudden Unexpected Death in Epilepsy).  Then you can say “I told you so, it was those Cation Chloride Cotransporter after all ”.

In spite of all the “evidence” that some autism is treatable, cognitive dysfunction is reversible, the world has not taken any notice.  Where is the undisputed concrete proof?  I just have to think “longitude and latitude”, that’s my proof.

So in reality while avoiding epilepsy should be a big deal for the parents, it is not for anyone else.  The current wisdom is keep your fingers crossed and hope that you are not in the one third that will develop epilepsy around puberty.  In some people this triggers an epigenetic change, opening the way to many future seizures.  For those who are interested:-

          Epigenetics and Epilepsy

If you follow 100 kids with autism on bumetanide for 10 years and found 5 developed seizures that would not be regarded as proof.

Based on my reading of the literature, you would expect 30+% of people with classic autism to develop epilepsy.  So if they had just 5 cases, I would see that as vindication, but it would not be seen as conclusive proof by others, just another paper to file and forget.

So the idea of prophylactic drug treatment to avoid the onset of epilepsy in autism is unlikely to catch on and is easy to rubbish.

Just like prophylactic use of drugs to avoid dementia, avoid type 2 diabetes or avoid the nasty side effects of type 1 diabetes, they will not enter the mainstream.

Conclusion

Setting low standards and targets will guarantee poor outcomes.  Aim to learn longitude and latitude, but it might be easier with a daily dose of bumetanide.

Some epilepsy is avoidable, some may not be, but if treating autism can also reduce the chance of epilepsy and SUDEP do you really need to wait for absolute evidence?

It is currently a matter of geography and google competence who is going to access effective pharmacotherapy.  For a change it is the poorer countries who have the advantage, since they have less rigid control over access to prescription medication.

I was just reading that the excellent New England Center for Children (NECC) charges up to $300,000 a year to educate kids with autism.  It is a great school and we employed a former teacher from there a few years ago, to help with our home program.  With something like 0.3% of all kids having serious autism, there needs to be a less expensive solution available to all.  

Spending $300,000 at NECC will almost definitely have a positive impact on one severely autistic child for one year.  Alternatively, for the same money, you could treat 480 kids with strict definition autism with my Polypill for one year.  It looks like around a half would respond very well.  Ideally you would spend $300,620 and have both the NECC and the Polypill; this is pretty much what was my target, but without leaving home.

 

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.