Low dose Clonazepam for MIA Autism, Ponstan and TRPM3 in Intellectual Disability, Clemastine to restore myelination in Pitt Hopkins, Improving Oxytocin therapy with Maca, Lamotrigine for some autism

 

Monty in Ginza, Tokyo

Today’s post comes from Tokyo and looks at 5 therapies already discussed in previous posts and follows up on recent coverage in the research. They all came up in recent conversations I have been having.

·      Low dose Clonazepam  – Maternal Immune Activation model of autism

·      Ponstan – TRPM3 causing intellectual disability  (ID/MR)

·      Clemastine – improving myelination in Pitt Hopkins syndrome model

·      Oxytocin – Maca supplement to boost effect

·      Lamotrigine (an anti-epilepsy drug) to moderate autism

The good news is that many of same therapies keep coming up.

Ponstan and TRPM3 caused ID/MR

There is a lot in this blog about improving cognition, which is how I called treating ID/MR.  There are very many causes of ID and some of them are treatable.

ID/MR was always a part of classic autism and in the new jargon is part of what they want to call profound autism.

I was recently sent a paper showing how the cheap pain reliever Ponstan blocks the TRMP3 channel and that this channel when mutated can lead to intellectual disability and epilepsy.

Mefenamic acid selectively inhibits TRPM3-mediated calcium entry.

My own research has established that mefenamic acid seems to improve speech and cognition, as well as sound sensitivity.  The latter effect I am putting down to its effect on potassium channels. 

De novo substitutions of TRPM3 cause intellectual disability and epilepsy

The developmental and epileptic encephalopathies (DEE) are a heterogeneous group of chronic encephalopathies frequently associated with rare de novo nonsynonymous coding variants in neuronally expressed genes. Here, we describe eight probands with a DEE phenotype comprising intellectual disability, epilepsy, and hypotonia. Exome trio analysis showed de novo variants in TRPM3, encoding a brain-expressed transient receptor potential channel, in each. Seven probands were identically heterozygous for a recurrent substitution, p.(Val837Met), in TRPM3’s S4–S5 linker region, a conserved domain proposed to undergo conformational change during gated channel opening. The eighth individual was heterozygous for a proline substitution, p.(Pro937Gln), at the boundary between TRPM3’s flexible pore-forming loop and an adjacent alpha-helix. General-population truncating variants and microdeletions occur throughout TRPM3, suggesting a pathomechanism other than simple haploinsufficiency. We conclude that de novo variants in TRPM3 are a cause of intellectual disability and epilepsy.

 

Fenamates as TRP channel blockers: mefenamic acid selectively blocks TRPM3

This study reveals that mefenamic acid selectively inhibits TRPM3-mediated calcium entry. This selectivity was further confirmed using insulin-secreting cells. K_ATP channel-dependent increases in cytosolic Ca²⁺ and insulin secretion were not blocked by mefenamic acid, but the selective stimulation of TRPM3-dependent Ca²⁺ entry and insulin secretion induced by pregnenolone sulphate were inhibited. However, the physiological regulator of TRPM3 in insulin-secreting cells remains to be elucidated, as well as the conditions under which the inhibition of TRPM3 can impair pancreatic β-cell function. Our results strongly suggest mefenamic acid is the most selective fenamate to interfere with TRPM3 function. 

Here, we examined the inhibitory effect of several available fenamates (DCDPC, flufenamic acid, mefenamic acid, meclofenamic acid, niflumic acid, S645648, tolfenamic acid) on the TRPM3 and TRPV4 channels using fluorescence-based FLIPR Ca²⁺ measurements. To further substantiate the selectivity, we tested the potencies of these fenamates on two other TRP channels from different subfamilies, TRPC6 and TRPM2. In addition, single-cell Ca²⁺ imaging, whole-cell voltage clamp and insulin secretion experiments revealed mefenamic acid as a selective blocker of TRPM3.

  

Oxytocin

 Oxytocin does increase how emotional you feel; the difficulty is how to administer it in a way that provides a long lasting effect.  The half-life of oxytocin is a just minutes. The traditional method uses a nose spray.

I favour the use of a gut bacteria that stimulates the release of oxytocin in the brain.  The effect should be much longer lasting. Even then the effect is more cute than dramatic.

The supplement Maca does not itself produce oxytocin, but “it restores social recognition impairments by augmenting the oxytocinergic neuronal pathways”.

So Maca looks like an interesting potential add-on therapy to boost the effect of oxytocin.

One reader wrote to me with a positive report on using Maca by itself, without any oxytocin.

 

Oral Supplementation with Maca Improves Social Recognition Deficits in the Valproic Acid Animal Model of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a congenital, lifelong neurodevelopmental disorder whose main symptom is impaired social communication and interaction. However, no drug can treat social deficits in patients with ASD, and treatments to alleviate social behavioral deficits are sorely needed. Here, we examined the effect of oral supplementation of maca (Lepidium meyenii) on social deficits of in utero-exposed valproic acid (VPA) mice, widely used as an ASD model. Although maca is widely consumed as a fertility enhancer and aphrodisiac, it possesses multiple beneficial activities. Additionally, it benefits learning and memory in experimental animal models. Therefore, the effect of maca supplementation on the social behavioral deficit of VPA mice was assessed using a social interaction test, a three-stage open field test, and a five-trial social memory test. The oral supplementation of maca attenuated social interaction behavior deficit and social memory impairment. The number of c-Fos-positive cells and the percentage of c-Fos-positive oxytocin neurons increased in supraoptic and paraventricular neurons of maca-treated VPA mice. These results reveal for the first time that maca is beneficial to social memory and that it restores social recognition impairments by augmenting the oxytocinergic neuronal pathways, which play an essential role in diverse social behaviors.

Maca (Lepidium meyenii) belongs to the cruciferous family and grows at high altitudes in Peru. In 2002, it was transplanted from Peru to the Yunnan Province of China. It is rich in dietary fiber; has many essential amino acids and nutrients including vitamin C, copper, and iron; and its root contains bioactive compounds. It is globally consumed and is popularly used as a fertility enhancer and aphrodisiac. On the other hand, with its potential to possess multi-nutritious components, it is reported to have diverse functions, including immunomodulation, antioxidant, antidepressant, antirheumatic, UV radiation protection, hepatoprotective, anti-fatigue, and neuroprotective effects. Interestingly, although the mechanism of the neuronal effect of maca is unclear, the uptake of maca extract improves learning and memory in memory-impaired model mice induced by either ethanol, ovariectomy, or scopolamine. However, the effects of maca on social memory impairment in neurodevelopmental disorders, including ASD, have not yet been tested.

In this study, the effects of maca on ASD animal models, in utero VPA-exposed mice, were investigated. The effect on social recognition by maca uptake with gavage was assessed using the social interaction test, a three-stage open field test, and the five-trail social recognition test. We also explored whether maca intake affects oxytocinergic signaling pathways, which play an important role in various social behaviors.

In this study, we showed that maca uptake rescues the deficits of social behavior and social recognition memory in VPA mice, a mouse model of autism. The c-Fos immunoreactivity of oxytocinergic neurons in SON and PVN increased significantly after maca treatment in VPA mice. Following previous studies indicating that OT administration ameliorates the impairment of social behavior in VPA mice, maca may also have improving effects on the deficit of social behavior and social recognition memory of VPA mice, probably by activating the OT neuronal pathway. Previous studies showed that maca could improve cognitive function in the mice model of impaired cognitive memory induced by either ovariectomy, ethanol, or scopolamine. Further studies are necessary to elucidate the potential link between maca and OT and to determine which components are involved in improving social recognition memory.

We have shown that maca improves the impairment of social memory and social behavioral deficits through oxytocinergic system modulation in this study. Although maca may not have an immediate effect on social behavioral deficits and takes days or weeks to demonstrate the effects, behavioral improvements, were visible regardless of the time of oral intake. The time between the very last oral intake of maca and the start of the social behavioral experiments in this study was more than 16 h. The duration of the maca’s effect on social behavioral deficits after the supplementation period is being investigated in our follow-up experiments. The possibility of the persistent effect of maca is very appealing, given that OT does not have a sustained effect due to its rapid metabolism, despite its immediate effects. Therefore, taking maca as a supplement while also receiving repeated OT treatment may have a synergistic, sustainable effect on improving social impairment in patients with ASD. Maca is already being used as a dietary supplement worldwide and has a high potential for practical applications.

 

This study showed for the first time that maca supplementation improves the impairment of social recognition memory in ASD model mice. We added the mechanism that social memory improvement may occur through the upregulation of oxytocinergic pathways. Maca highlights the possibility of treating social deficits sustainably in individuals with ASDs.

 

Low dose clonazepam

Professor Catterall was the brains behind low dose clonazepam for mice, I just translated it across to humans. It is one way to modify the E/I (excitatory/inhibitory) imbalance in autism.

I found that it gave a boost to cognition. Not as big as bumetanide, but worth having nonetheless.

I do not believe you have to be a bumetanide responder to respond well to low dose clonazepam.

Several people have written to me recently to say it works for their child.

Our reader Tanya is interested in the Maternal Immune Activation (MIA) trigger to autism. She highlighted a recent study showing how and why clonazepam can reverse autism in the MIA mouse model of autism. 

Clonazepam attenuates neurobehavioral abnormalities in offspring exposed to maternal immune activation by enhancing GABAergic neurotransmission

Ample evidence indicates that maternal immune activation (MIA) during gestation is linked to an increased risk for neurodevelopmental and psychiatric disorders, such as autism spectrum disorder (ASD), anxiety and depression, in offspring. However, the underlying mechanism for such a link remains largely elusive. Here, we performed RNA sequencing (RNA-seq) to examine the transcriptional profiles changes in mice in response to MIA and identified that the expression of Scn1a gene, encoding the pore-forming α-subunit of the brain voltage-gated sodium channel type-1 (Na_V1.1) primarily in fast-spiking inhibitory interneurons, was significantly decreased in the medial prefrontal cortex (mPFC) of juvenile offspring after MIA. Moreover, diminished excitatory drive onto interneurons causes reduction of spontaneous gamma-aminobutyric acid (GABA)ergic neurotransmission in the mPFC of MIA offspring, leading to hyperactivity in this brain region. Remarkably, treatment with low-dose benzodiazepines clonazepam, an agonist of GABA_A receptors, completely prevented the behavioral abnormalities, including stereotypies, social deficits, anxiety- and depression-like behavior, via increasing inhibitory neurotransmission as well as decreasing neural activity in the mPFC of MIA offspring. Our results demonstrate that decreased expression of Na_V1.1 in the mPFC leads to abnormalities in maternal inflammation-related behaviors and provides a potential therapeutic strategy for the abnormal behavioral phenotypes observed in the offspring exposed to MIA.

 

Pitt Hopkins – Clemastine and Sobetirome

Poor myelination is a feature of much autism and is a known problem in Pitt Hopkins syndrome.

I did cover a paper a while back where the Pitt Hopkins researchers showed that genes involved in myelination are down-regulated not only in Pitt Hopkins, but in several other popular models of autism.

From the multiple sclerosis (MS) research we have assembled a long list of therapies to improve different processes involved in myelination. Today we can add to that list sobetirome (and the related Sob-AM2). Sobetirome shares some of its effects with thyroid hormone (TH), it is a thyroid hormone receptor isoform beta-1 (THRβ-1) liver-selective analog.

Some people do use thyroid hormones to treat autism, and indeed US psychiatrists have long used T3 to treat depression.

The problem with giving T3 or T4 hormones is that it has body-wide effects and if you give too much the thyroid gland will just produce less.

One proposed mechanism I wrote about long ago is central hypothyroidism, that is a lack of the active T3 hormone just within the brain. One possible cause proposed was that oxidative stress reduces the enzyme D2 that is used to convert circulating prohormone T4 to T3. The result is that your blood test says your thyoid function is great, but in your brain you lack T3.

It looks like using sobetirome you can spice up myelination in the brain, without causing any negative effects to your thyroid gland.

Rather surprisingly, sobetirome is already sold as a supplement, but it is not cheap like Clemastine, the other drug used in the successful study below.

 

Promyelinating drugs promote functional recovery in an autism spectrum disorder mouse model of Pitt–Hopkins syndrome

Pitt–Hopkins syndrome is an autism spectrum disorder caused by autosomal dominant mutations in the human transcription factor 4 gene (TCF4). One pathobiological process caused by murine Tcf4 mutation is a cell autonomous reduction in oligodendrocytes and myelination. In this study, we show that the promyelinating compounds, clemastine, sobetirome and Sob-AM2 are effective at restoring myelination defects in a Pitt–Hopkins syndrome mouse model. In vitro, clemastine treatment reduced excess oligodendrocyte precursor cells and normalized oligodendrocyte density. In vivo, 2-week intraperitoneal administration of clemastine also normalized oligodendrocyte precursor cell and oligodendrocyte density in the cortex of Tcf4 mutant mice and appeared to increase the number of axons undergoing myelination, as EM imaging of the corpus callosum showed a significant increase in the proportion of uncompacted myelin and an overall reduction in the g-ratio. Importantly, this treatment paradigm resulted in functional rescue by improving electrophysiology and behaviour. To confirm behavioural rescue was achieved via enhancing myelination, we show that treatment with the thyroid hormone receptor agonist sobetirome or its brain penetrating prodrug Sob-AM2, was also effective at normalizing oligodendrocyte precursor cell and oligodendrocyte densities and behaviour in the Pitt–Hopkins syndrome mouse model. Together, these results provide preclinical evidence that promyelinating therapies may be beneficial in Pitt–Hopkins syndrome and potentially other neurodevelopmental disorders characterized by dysmyelination.

 

Sobetirome  (also called GC-1)

Sobetirome is a thyroid hormone receptor isoform beta-1 (THRβ-1) liver-selective analog.

In humans, sobetirome lowers plasma LDL cholesterol and reduced plasma triglycerides, while its liver-selective activity helped avoid the side effects seen with many other thyromimetic agents.

 

Myelin repair stimulated by CNS-selective thyroid hormone action

Oligodendrocyte processes wrap axons to form neuroprotective myelin sheaths, and damage to myelin in disorders, such as multiple sclerosis (MS), leads to neurodegeneration and disability. There are currently no approved treatments for MS that stimulate myelin repair. During development, thyroid hormone (TH) promotes myelination through enhancing oligodendrocyte differentiation; however, TH itself is unsuitable as a remyelination therapy due to adverse systemic effects. This problem is overcome with selective TH agonists, sobetirome and a CNS-selective prodrug of sobetirome called Sob-AM2. We show here that TH and sobetirome stimulated remyelination in standard gliotoxin models of demyelination. We then utilized a genetic mouse model of demyelination and remyelination, in which we employed motor function tests, histology, and MRI to demonstrate that chronic treatment with sobetirome or Sob-AM2 leads to significant improvement in both clinical signs and remyelination. In contrast, chronic treatment with TH in this model inhibited the endogenous myelin repair and exacerbated disease. These results support the clinical investigation of selective CNS-penetrating TH agonists, but not TH, for myelin repair.

 

Compound protects myelin, nerve fibers

 

Research could be important in treating, preventing progression of multiple sclerosis, other neurodegenerative diseases

A compound appears to protect nerve fibers and the fatty sheath, called myelin, that covers nerve cells in the brain and spinal cord. The new research in a mouse model advances earlier work to develop the compound - known as sobetirome - that has already showed promise in stimulating the repair of myelin.

Lead author Priya Chaudhary, M.D., assistant professor of neurology in the OHSU School of Medicine who is focused on developing therapies for neurodegenerative diseases, said that the technique is a common step in drug discovery.

"It is important to show the effectiveness of potential drugs in a model that is most commonly used for developing new therapies," Chaudhary said.

The researchers discovered that they were able to prevent damage to myelin and nerve fibers from occurring, by stimulating a protective response in the cells that make and maintain myelin. They also reduced the activity of migroglia, a type of inflammatory cell in the brain and spinal cord that's involved in causing damage in multiple sclerosis and other diseases.

"The effects are impressive and are at least in part consistent with a neuroprotective effect with particular inhibition of myelin and axon degeneration, and oligodendrocyte loss," the authors write.

The discovery, if proven in clinical trials involving people, could be especially useful for people who are diagnosed with multiple sclerosis early in the disease's progression.

"The drug could protect the nervous system from damage and reduce the severity of the disease," Bourdette said.

 

Does Lamotrigine have the potential to 'cure' Autism?

Recently headlines appeared like this one:-

Scientists 'CURE autism' in mice using $3 epilepsy drug

It referred to the use of the epilepsy drug Lamotrigine to treat a mouse model of autism, caused by reduced expression of the gene MYT1L.

What the tabloid journalists failed to notice was that there has already been a human trial of Lamotrigine in autism.  That trial was viewed as unsuccessful by the clinicians, although the parents did not agree.

There were many comments in the media from parents whose child already takes this drug for their epilepsy and they saw no reduction in autism. There were some who found it made autism worse.

 

MYT1L haploinsufficiency in human neurons and mice causes autism-associated phenotypes that can be reversed by genetic and pharmacologic intervention

 

Lamotrigine therapy for autistic disorder: a randomized, double-blind, placebo-controlled trial

In autism, glutamate may be increased or its receptors up-regulated as part of an excitotoxic process that damages neural networks and subsequently contributes to behavioral and cognitive deficits seen in the disorder. This was a double-blind, placebo-controlled, parallel group study of lamotrigine, an agent that modulates glutamate release. Twenty-eight children (27 boys) ages 3 to 11 years (M = 5.8) with a primary diagnosis of autistic disorder received either placebo or lamotrigine twice daily. In children on lamotrigine, the drug was titrated upward over 8 weeks to reach a mean maintenance dose of 5.0 mg/kg per day. This dose was then maintained for 4 weeks. Following maintenance evaluations, the drug was tapered down over 2 weeks. The trial ended with a 4-week drug-free period. Outcome measures included improvements in severity and behavioral features of autistic disorder (stereotypies, lethargy, irritability, hyperactivity, emotional reciprocity, sharing pleasures) and improvements in language and communication, socialization, and daily living skills noted after 12 weeks (the end of a 4-week maintenance phase). We did not find any significant differences in improvements between lamotrigine or placebo groups on the Autism Behavior Checklist, the Aberrant Behavior Checklist, the Vineland Adaptive Behavior scales, the PL-ADOS, or the CARS. Parent rating scales showed marked improvements, presumably due to expectations of benefits.

One reader of this blog who heard all about the news and was sceptical, since after all it is a mouse model. Her 8 year old non-verbal child was not happy taking the drug Keppra and was already scheduled to try Lamotrigine. 

“Within a week his teacher called to say he was saying his ABCs, the next week he was counting out loud, the following month he’s attempting to repeat words of interest and this week he’s spelling animals by memory, dolphin, duck, wolf, chicken, pig, etc.

We are 2 months in and at 50mg, our target dose is 100mg bid. Obviously with our success, I’ve been working with his doctor and will continue to.”

 

Conclusion

Even though every day new autism research is published, there is so much already in this blog that not much appearing is totally new to regular readers.

We saw several years ago that low dose clonazepam should be beneficial to some people with autism, in particular Dravet syndrome. Today we learnt a little more about why Nav1.1 might be disturbed beyond those with Dravet syndrome. In the maternal immune activation model it seems to be a winner. It seems to benefit many of those who have trialed it.

Treating myelination deficits has been well covered in this blog. In previous posts we saw how Pitt Hopkins syndrome researchers showed how myelination gene expression was disturbed in a wide range of autisms. Today we saw evidence to support such therapy and we discovered a new drug.

Oxytocin does help some people with autism, but not as much as you might expect. Today we learnt of a potential add on therapy, a supplement called Maca.

The idea that anti-epilepsy drugs might help some autism has been well covered. From low dose valproate to low dose phenytoin from Dr Philip Bird in Australia.

Treatment of Autism with low-dose Phenytoin, yet another AED

Recent research suggested that Lamotrigine should help some with autism and today you learned that it really does help in one case. The fact that a tiny study a few years ago suggested no responders just tells us that only a small subgroup are likely to benefit.

We already know that some people's autism is made worse by their epilepsy therapy. This is just what you would expect. Time to find a different epilepsy therapy.

My favorite new therapy, low dose mefenemic acid / ponstan has numerous effects. One reader without autism, but with an unusual visual dysfunction (visual snow syndrome) and a sound sensitivity problem contacted me a while to see if NKCC1 might be the root of his problem. I suggested he try Ponstan, which did actually work for him and is easy to buy where he lives. Now he sends me research into all its possible modes of action. One mode of action relates to a cause of intellectual disability (ID/MR). Is this a factor in why Ponstan seems to improve speech and cognition in some autism? I really don't mind why it works - I just got lucky again, that is how I look at it. The more I read the luckier I seem to get.