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Showing posts with label ID. Show all posts
Showing posts with label ID. Show all posts

Thursday, 18 April 2019

Wnt, TCF4 and Pre-myelinating Oligodendrocytes


Cartoons in art class - Monty is getting ready for Easter break, but not in the Maldives

Today’s post may sound very complicated and narrow, but it is very relevant to people with the following: - 

·        Pitt Hopkins Syndrome (insufficient expression of the Transcription Factor #4  TCF4 gene)

·        Multiple Sclerosis

·        Some Mental Retardation/Intellectual Disability (MR/ID)

·        Schizophrenia

·        Impaired Wnt signalling

·        Perhaps PAK1 inhibitor responders

I do feel that Multiple Sclerosis could be treated very much better if some effort was made to translate the existing science, freely available to all, into therapy. You could greatly improve many people’s lives just by repurposing cheap existing drugs.
In simple terms, to produce myelin that you need to coat axons in your brain, you need a type of cell called an oligodendrocyte (OL).  You need a lot of these cells and you need them to get busy. They place tiny pieces of white insulation along axons of your brain cells, this produces the so called “white matter”.  These pieces of insulation are needed to make electrical signals flow correctly in your brain.
It has been shown that in some people the oligodendrocyte precursors (OLPs) do not “mature” and instead get stuck as premyelinated oligodendrocytes (pre-OL). That means reduced myelination and loss of white matter.

It is clearly shown in the graphic below: -








































Tcf4 is expressed in oligodendrocyte lineage in human developmental white matter and in active areas of MS lesions. (A) Tcf4 is expressed in white matter tracts during myelination of human developmental brain at postnatal age 1 mo, 3.5 mo, and 16 mo, but is not expressed by 7 yr. Tcf4 colocalizes with Olig2 when expressed in the developing human corpus callosum. (B) Tcf4 protein expression is evident in active MS lesions, but it is not seen in normal-appearing white matter (NAWM) or in the core of chronic MS lesions. An illustrative MS case is shown with several lesion types present. NAWM stains with Luxol Fast Blue (LFB) and contains sparse LN3(HLA-DR)-positive inflammatory cells, organized SMI-31 axon fibers, and no Tcf4-positive cells. Chronic plaques have sparse LFB staining and LN3-positive cells, intact axons, but no Tcf4-positive cells. In contrast, Tcf4-positive cells are present in active areas of plaques with abundant LN3-positive cells and intact demyelinated axons. Tcf4 expression in active lesions colocalizes (open arrowheads) with a subset of Olig2 cells.


Don’t worry if you don't follow everything. There is nothing wrong with your white matter.
We come back to Wnt signalling that we covered in depth in older posts. This is a complex signalling pathway implicated in autism, some cancers and other conditions. You can both increase and reduce Wnt signalling, which will affect the transcription of numerous genes.
TCF4 is the Pitt Hopkins gene. We have across this syndrome several times, while it is rare, a milder miss-expression of the gene is actually quite common.  Reduced expression of TCF4 is a common feature of MR/ID very broadly. TCF4 has been found to be over-expressed in schizophrenia.
People with Multiple Sclerosis (MS) have been found to have oligodendrocytes “stuck” as non-myelinating (premyelinated oligodendrocytes, pre-OL). Inhibiting the Wnt pathway might play a role in treatment during periods of acute demyelination, when there is a lack of newly minted myelin-producing oligodendrocytes. The study below does refer to Wnt inhibitors in the pipeline as potential cancer therapies.  It looks to me that safe Wnt inhibitors like the cheap drugs widely used to treat children with parasites (Mebendazole/ Niclosamide) could be repurposed to treat the acute phase of multiple sclerosis.
Mebendazole/ Niclosamide are safe and dirt cheap, whereas the (slightly) disease changing MS drugs currently cost $50,000+ a year.

TCF4 links everything together
Wnt signalling needs to be active to block premyelinated oligodendrocytes into transforming into oligodendrocytes (OL). So by inhibiting Wnt signalling you may remove one of the problems in MS; you probably only need to do this during relapses of MS.  
There actually is a finally stage to getting the oligodendrocytes (OL) to myelinate many axons and not be lazy.
In the jargon “dysregulation of Wnt–β-catenin signaling in OLPs results in profound delay of both developmental myelination and remyelination”.
A miss-expression of TCF4 is clearly also going to affect myelination and its does in both Pitt Hopkins and MS.
One feature of Pitt Hopkins (caused by haploinsufficiency of the transcription factor 4) is indeed delayed myelination measured via MRI at the age of 1. By the age of 9 white matter (the myelin-coated part of your brain) appears normal. This fits with what I highlighted in red under figure 6 above.
Nothing is simple. Activating Wnt signalling is known to increase expression of TCF4.  


The progressive loss of CNS myelin in patients with multiple sclerosis (MS) has been proposed to result from the combined effects of damage to oligodendrocytes and failure of remyelination. A common feature of demyelinated lesions is the presence of oligodendrocyte precursors (OLPs) blocked at a premyelinating stage. However, the mechanistic basis for inhibition of myelin repair is incompletely understood. To identify novel regulators of OLP differentiation, potentially dysregulated during repair, we performed a genome-wide screen of 1040 transcription factor-encoding genes expressed in remyelinating rodent lesions. We report that 50 transcription factor-encoding genes show dynamic expression during repair and that expression of the Wnt pathway mediator Tcf4 (aka Tcf7l2) within OLPs is specific to lesioned—but not normal—adult white matter. We report that β-catenin signaling is active during oligodendrocyte development and remyelination in vivo. Moreover, we observed similar regulation of Tcf4 in the developing human CNS and lesions of MS. Data mining revealed elevated levels of Wnt pathway mRNA transcripts and proteins within MS lesions, indicating activation of the pathway in this pathological context. We show that dysregulation of Wnt–β-catenin signaling in OLPs results in profound delay of both developmental myelination and remyelination, based on (1) conditional activation of β-catenin in the oligodendrocyte lineage in vivo and (2) findings from APCMin mice, which lack one functional copy of the endogenous Wnt pathway inhibitor APC. Together, our findings indicate that dysregulated Wnt–β-catenin signaling inhibits myelination/remyelination in the mammalian CNS. Evidence of Wnt pathway activity in human MS lesions suggests that its dysregulation might contribute to inefficient myelin repair in human neurological disorders 
Potential Tcf4-catenin activities in oligodendrocyte development
The pattern of Tcf4 protein expression, from P1 to P30 and during remyelination after injury, defines the window of potential canonical Wnt pathway functions. Within this context, we observed that Tcf4 expression marked 15%–20% of OLPs at any given stage assessed. These findings were consistent with two possibilities. First, Tcf4 expression could demarcate a subset of OLPs. Second, it was possible that Tcf4 expression transiently marks all (or the vast majority) of OLPs during development. Our functional evidence strongly supports the latter conclusion, based on the fact that activity of activated β-catenin is Tcf-dependent (van de Wetering et al. 2002), coupled with the robust phenotype in DA-Cat and APCMin animals, in which we observe pervasive effects of Wnt pathway dysregulation on myelin production throughout the CNS. Interestingly, although Tcf4 proteins are coexpressed with nuclear Olig1 proteins, Tcf4 segregated from cells expressing Olig1 mRNA transcripts, consistent with the possibility that Tcf4 is expressed at a transition stage when nuclear Olig1 proteins become down-regulated during remyelination.

Previous work has suggested inhibitory functions of Tcf4 on myelin basic protein gene expression in vitro (He et al. 2007), and our studies indicate that Tcf4 interactions with β-catenin inhibit myelination in vivo. Additional studies are warranted to rule out possible β-catenin-independent roles for Tcf4 in oligodendrocyte development. Although Wnt pathway activation has conventionally been thought of as activating gene targets, recent work has identified novel Tcf–β-catenin DNA regulatory binding sites that repress targets (Blauwwkamp et al. 2008). In this regard, one intriguing candidate target is HYCCIN (DRCTNNB1A), a Wnt-repressed target (Kawasoe et al. 2000) with essential roles in human myelination (Zara et al. 2006), which is expressed in rodent oligodendrocytes and down-regulated in Olig2cre/DA-Cat mice (Supplemental Fig. 8). Further studies are needed to better understand Tcf4–catenin function and its direct gene targets during oligodendrocyte lineage progression.

Wnt pathway dysregulation in OLPs as a mechanism leading to chronic demyelination in human white matter diseases
Therapeutic opportunities might arise from an enhanced understanding of the process regulating normal kinetics of remyelination. How might the negative regulatory role of the canonical Wnt pathway help to explain the pathology of demyelinating disease? Delayed remyelination due to Wnt pathway dysregulation in OLPs could lead to chronic demyelination by OLPs then missing a “critical window” for differentiation (Miller and Mi 2007; Franklin and Ffrench-Constant 2008). This “dysregulation model” of remyelination failure requires the Wnt pathway to be active during acute demyelination, as suggested by data from our animal systems and human MS tissue.
Canonical WNT signaling has been implicated in a variety of human diseases (Nelson and Nusse 2004), and gain-of-function mutations in β-catenin are etiologic in several cancers including the majority of colon adenocarcinomas. Approaches for treating Wnt-dependent cancers by promoting differentiation (and hence cell cycle arrest or apoptosis) using pharmacological inhibitors of the pathway are under development (Barker and Clevers 2005). It is possible that such antagonists might play a role in the therapeutic enhancement of remyelination by normalizing the kinetics of myelin repair. If so, the animal models described here (e.g., APC+/−) should be useful in preclinical testing. However, it is important to note that while dysregulation of a pathway might delay remyelination, it is overly simplistic to expect that inhibition of the same pathway would accelerate repair in the complex milieu of an MS lesion in which several inhibitory pathways might be active, compounded by the presence of myelin debris (Kotter et al. 2006). Indeed, because of the need to synergize with other processes (e.g., those associated with inflammation), accelerated differentiation might negatively affect repair (Franklin and Ffrench-Constant 2008). Further work is needed to comprehensively understand interactions of regulatory networks required for optimal remyelination and how these may be dysregulated in human demyelinating diseases.

Neurologic and ocular phenotype in Pitt-Hopkins syndrome and a zebrafish model.


Abstract


In this study, we performed an in-depth analysis of the neurologic and ophthalmologic phenotype in a patient with Pitt-Hopkins syndrome (PTHS), a disorder characterized by severe mental and motor retardation, carrying a uniallelic TCF4 deletion, and studied a zebrafish model. The PTHS-patient was characterized by high-resolution magnetic resonance imaging (MRI) with diffusion tensor imaging to analyze the brain structurally, spectral-domain optical coherence tomography to visualize the retinal layers, and electroretinography to evaluate retinal function. A zebrafish model was generated by knockdown of tcf4-function by injection of morpholino antisense oligos into zebrafish embryos and the morphant phenotype was characterized for expression of neural differentiation genes neurog1, ascl1b, pax6a, zic1, atoh1a, atoh2b. Data from PTHS-patient and zebrafish morphants were compared. While a cerebral MRI-scan showed markedly delayed myelination and ventriculomegaly in the 1-year-old PTHS-patient, no structural cerebral anomalies including no white matter tract alterations were detected at 9 years of age. Structural ocular examinations showed highly myopic eyes and an increase in ocular length, while retinal layers were normal. Knockdown of tcf4-function in zebrafish embryos resulted in a developmental delay or defects in terminal differentiation of brain and eyes, small eyes with a relative increase in ocular length and an enlargement of the hindbrain ventricle. In summary, tcf4-knockdown in zebrafish embryos does not seem to affect early neural patterning and regionalization of the forebrain, but may be involved in later aspects of neurogenesis and differentiation. We provide evidence for a role of TCF4/E2-2 in ocular growth control in PTHS-patients and the zebrafish model. 


Conclusion  

If you have a myelinating disease, you might want to read up on TCF4 and Wnt signalling. Probably not what the Minions take to read on the beach in the Maldives.

We also should recall the importance of what I am calling the "what, when and where" in neurological disorders. This is important for late onset disorders like schizophrenia, since the symptoms often develops in late teenage years and so it is potentially preventable, if identified early enough.

Today we see that TCF4 is expressed in white matter only in early childhood. If you knew what changes take place in the brains of children who go on to develop schizophrenia, you might well be able to prevent its onset.

Preventing some autism is already possible, as has been shown in mouse models, but in humans it is more complicated because of the "when" and quite literally the "where". There will be a post showing how the brain overgrowth typical of autism can be prevented using bumetanide, before it occurs, at least in mice.


  












Thursday, 10 May 2018

Accept Autism or Treat It?


Back in the old days autism was a hidden condition and those affected were usually tucked away in institutions. A trend then slowly developed towards inclusion, with the Individuals with Disabilities Education Act (IDEA) being passed in 1975 in the US.  Other countries have slowly moved in this direction, with France only this year finally following suit.



Having moved on from hiding autism, we then had the new diagnosis of Asperger’s appearing in the 1990s and so autism became a much broader diagnosis. Then followed the idea of awareness and diagnosing adults.
Now we have an ever-growing number of people diagnosed with this “autism” thing, that other people are supposed to be aware of. Is it a disease, a dysfunction, a disability or just a difference?
Most importantly are you supposed to treat it, or just accept it?
I recently watched a BBC documentary where a doctor was the presenter and she was talking about schizophrenia. She said that at medical school she was taught that there are medical problems and there are mental health problems, for some reason she was taught that mental health problems are not just medical problems of the brain. Somehow mental health problems are supposed to be different and not based in biology, where did that idea come from?
The program went on to show that about 8% of schizophrenia appears to be caused by NMDAR antibodies. This is a condition where antibodies attack NMDA receptors in the brain, this causes hallucinations and other symptoms that a psychiatrist would diagnose as schizophrenia.  Rather than treating lifelong with anti-psychotics, the patient needs immunotherapy and can then resume a normal life.
It looks like 30% of modern autism is associated with cognitive impairment leading to a measured IQ of less than 70. This is intellectual disability (ID) to autism parents and mental retardation (MR) to the rest of the world.
The interesting finding in this blog is that some MR/ID is actually treatable. I did suggest to the Bumetanide researchers that they should include measuring IQ in their clinical trials.
I do not see how anyone could object to treating MR/ID, even those parents with Asperger’s who find the idea of treating their child’s severe autism to be repulsive.

Maths, Autism and Hans Asperger
Some people with Asperger’s are brilliant at maths, and I think these are the ones that Hans Asperger was mostly studying in Vienna in the 1940s. Lorna Wing came along in 1981 and then Uta Frith in 1991 and translated into English one of Asperger’s 300 papers, the 1943/4 “Die Autistischen Psychopathen im Kindesalter” and then named autism with no speech delay as Asperger’s Syndrome.
In 1994 the Americans adopted Asperger’s as a diagnosis and then rejected it two decades later in 2013 (DSM5).
In Asperger’s 1943 paper he described Fritz, Harro, Ernst and Hellmuth, who he termed "autistic psychopaths”; all four had high IQs and Asperger called them "little professors" because they could talk about the area of ​​their special interest in detail and often accumulated amazing knowledge.
I think Asperger’s should have been left as the "Little Professor’s Syndrome" (high IQ only).
In 2018 some people have realized that from the mid 1930’s almost all people in high positions in Austria and Germany were implicated in some pretty evil Nazi programs, including killing mentally disabled children. Asperger, being a senior psychiatrist at the University of Vienna, obviously played a role, not wanting to pay a visit to the local Gestapo basement.  He was living in a police state, where people tend to do what they are told.  Unlike most of the University medical faculty he was not a member of the Nazi party.
The particularly evil Austrian psychiatrist was Dr Emil Gelny, who modified an ECT (Electro Convulsive Therapy) device to give his subjects lethal shocks. Having personally killed hundreds of mental patients, after the end of the war he escaped to Baghdad, continued practising as a doctor and lived till he was 71. He was never brought to account and Mossad clearly never paid a visit, so I guess there were no Jewish victims.  His highly publicized use of ECT is one reason why it is little used today, even though it does seem to help certain otherwise untreatable conditions.
What surprised me was that in 1930 (before the rise of Hitler) half of the doctors in Vienna were Jewish and indeed half of the Vienna medical faculty were Jewish. So not so anti-Semitic in 1930.  All these doctors had to leave and so the young Hans Asperger made rapid career progress.
Things were not all rosy elsewhere.
I recently read that in London in the 1950s Jewish doctors struggled to progress within the faculty of medical schools and so some emigrated to the US.
We should also note that the Nazis took their inspiration for eugenics from America, where it backed by well-known names such as the Carnegie Institution and the Rockefeller Foundation. California, which we now might consider very liberal, was the centre for forced sterilization.  Between 1907 and 1963 over 64,000 individuals were forcibly sterilized under eugenic legislation in the United States.
So, I think Asperger deserves a break, he was likely no better or worse than other Austrians, unlike most he did not join the Nazi Party. Wing and Frith (a German) were naïve to name a psychiatric syndrome based on the work of an Austrian written during the Nazi period. I think you would not name a reservation for native Americans after General George Custer. 

Back to Maths
One group of kids with severe autism do have near/distant relatives who have remarkable maths skills but were never diagnosed with anything other than being a bit odd.
Monty, now aged 14 with ASD, had great difficulty with even the most basic maths until the age of 9, so much so that we did not bother to teach it, we focused on literacy.
Five and a half years of drug treatment has produced a boy who is now great at maths, at least in his class of 12 years olds.
Coordinates, no problem; negative numbers, no problem. It still now shocks those who knew him from before.
Today I received a message from Monty’s assistant at school and a photo of his classwork, where he is solving simple equations like
7x - 6 = 15
That is not a complex problem for a typical boy, but at the age of 9, after 5 years of intensive ABA therapy, we were still challenged by the most basic single digit addition.  


Nice neat handwriting


Should you treat autism? 

Pretty obviously I think autism should be treated. I would favour treating all types of genuine disease.
If you can treat it, I’d definitely call it a disease.
I would treat people with Down Syndrome to raise their IQs to improve their quality of life and I would also treat them preventatively to avoid early onset Alzheimer’s, which they are highly likely to develop. By the age of just 40 years old, studies have shown significant levels of amyloid plaques and tau tangles, which will lead to Alzheimer’s type dementia.
If you cannot treat it, then you’re just going to have to accept it.
But how would you know you cannot treat it, if you do not at least try?
Since there are hundreds of types of autism, there is no one-stop treatment shop for autism. For medical advice you should go to see a doctor, but mainstream medicine believes autism is untreatable. Today it is really up to the parents themselves to figure out what, if anything, to do.  Dr Frye might suggest you try Leucovorin, B12 and NAC; some DAN doctor will tell you it is all about candida; another will treat everyone with cod liver oil; another will blame parasites; most will blame vaccines.  One lady will charge you large amounts of money for her genetic tests, baffle you with complicated looking charts and then sell you her supplements by the bucket-load. This blog suggests numerous therapies may be partially effective in specific people, a case for personalized medicine.  My Polypill is what works for my son's autism; it is nice to know it works for some others, but it does not work for all autism, that would never be possible.  
With schizophrenia, you could start by treating that 8% with NMDAR antibodies via a science-based medical therapy; this has got to be a big step forward over psychiatric drugs.
We have gone from aged 9, struggling with: -
5 + 2 =  ?
To aged 14, solving worded maths questions, where you have to create the formula and to neatly solving simple equations like:

7x – 6  =  15                  
In algebra there is no doubt effective treatment wins over acceptance.

There is more to life than algebra, but it looks pretty clear that going through life with an IQ 30+ points less than your potential is a missed opportunity. 

Trivial autism
Many people with mild autism and an IQ much greater than 70 are happy the way they are and do not want treatment. For them autism is not a disability, it is just a difference, so we might call it trivial autism.  Unless years later they commit suicide or hurt other people, then it was not so trivial after all.
Unfortunately, some people with trivial autism will go on to produce children with not so trivial autism.
Then you end up with situation that the adult can block what is in the child’s interest, just like deaf parents who refuse their deaf child to have cochlear implants to gain some sense of hearing. Cochlear implants are only effective when implanted in very young children, so by the time you are old enough to have you own say in the decision, it is too late.  Some deaf parents do not want hearing children – odd but true.
So, I come back to my earlier point better to treat ID/MR, don’t even call it treating autism.
How can the Asperger’s mother then refuse treatment to her son with autism plus MR/ID? She can still be able to celebrate her difference, while he gets a chance to learn to tie his own shoe laces, put his shirt on the right way around and do all kinds of other useful things.


So, focus on the 31% of autism? 





                     
Unfortunately, in the research trials they often exclude severe autism, so they exclude people with epilepsy, people with MR/ID and people will self-injurious behaviour (SIB). The very people who clearly need treatment are excluded from the trials to determine what are effective autism treatments. Rather odd.




Thursday, 7 December 2017

Trajectories of Intellectual Development in Autism




Tracking IQ over a 3-4 year period, in 4 sub-groups of 2-8 year olds

Today’s post is about trajectories of intellectual development in autism, which I have to come to believe is the most important aspect of autism and certainly helps you understand where your type of autism fits in.
As regular readers may recall average IQ = 100 and the IQ scale fits a bell-curve, so most (68%) people have an IQ within the range 85-115.  2.1% of the general population have an IQ less than 70, which is the cut off for a diagnosis of MR/ID (Intellectual Disability).
There are special tests to measure IQ in non-verbal people and IQ testing is matched to your age; so the older a child gets the more there is expected from them in the test.
I do wonder how you can fairly test the IQ of a 2 year old with severe autism. So I think some testing in very young children may substantially underestimate IQ. 
A study was recently published taking data from the Autism Phenome Project run by UC Davies.



Even though the sample size is only a hundred, what makes it interesting is that it is a longitudinal study, meaning they collect data from the same kids over a period of many years.


They fitted data from the hundred kids into four groups and then took the average IQs within each group. The kids had IQ measured twice, not at exactly the same ages, but about 4 years apart. (The youngest at T1 was two years old and the oldest at T2 was eight)
I used their data and apply my interpretation. I do not think they made the most of their own data.
So the first group (black) are the Asperger’s kids who were 22% of the sample group.  This group started out at 2-3 years old with IQ just under 100 but in the next 4 years they raised their cognition at an above average rate, so that average IQ rose to 110. Not bad going.   Average IQ in the general population is 100.
Classic autism is the red group at the bottom and as expected their IQ starts out low and gets worse, because they add skills at a lower rate then NT kids, so even though they learn, their measured IQ falls. This group was 26%.  Even though the sample is very small at 100, this is close to my estimate of classic autism (SDA) being about 30% of all autism. In some countries you have to measure IQ to access services. Our behavioral consultant was not a fan, because the parents get upset when IQ goes down over time, so we never measured IQ. The red line is even lower than I had expected.
The green line I called responsive autism, because even though IQ is low it does not fall during the 4 years period where it was measured. This group account for 18% of the total. These children are acquiring new skills at a fair rate.
The good news is the blue line; in that large sub-group of 35%, the kids had some kind of “dysmaturation” at time 1, allowing them to make rapid cognitive improvement in the 4 years after their diagnosis (Time 1). They have gone from a technical definition of MR/ID to getting close to average IQ.
It would be great to see what happens at Time 3. I suppose if we wait 4 years we may find out.
I think some of the 35% (blue line) likely did not perform to their full ability at the first test (at time 1), for which there are numerous reasons, not liking/being familiar with the tester being an obvious one.  Based on other sources from this blog, I think it is about 15% of autism cases that make such a dramatic improvement to the age of eight.

In the above study the type of intervention chosen by parents (how many hours of ABA, speech therapy etc) had no correlation with IQ improvement from Time 1 to Time 2. It is your biology that matters most and to tweak that you need a little help from chemistry, as some regular readers have discovered. 

Counter Argument 
There is a alternative view that IQ is not important in ensuring favorable outcomes in autism; this does sound rather odd. It is a view put forward not just by the small, but vocal, group with Asperger's promoting their "neurodiversity" ideas, but also some well paid researchers. In my chart above I used Asperger's for the black line representing the people with average IQ. In the actual paper they do not call it Asperger's.


Intelligence scores do not predict success for autistic adults 

This is a very recent, rather light weight, article and would be much better if titled "Intelligence scores do not predict success for Aspies."   
Aspies do indeed share some biological problems with people with severe autism, but their daily life problems are much closer to those faced by people with Schizophrenia or Bipolar. A good example is suicide, where it is extremely common in bipolar, said to be 10% (as cause of death) in schizophrenia and ten times the "normal" level in Asperger's.  In severe autism the suicide rate is zero, they may have accidents but do not try to kill themselves.

In someone with Asperger's and an IQ of 120, boosting their IQ to 140 will likely not help them; it would just make them feel more different. In a ten year old with severe autism and an IQ of 50, a child who cannot figure out which way round to put on his T shirt, cannot tie his shoelaces and does not understand why you need to cut your finger nails, a boost in IQ to 80 would be transformative. 
The education of people with severe autism focuses on adaptive behavior, or life skills. These are key skills for semi-independent living. These are skills that children of average IQ just pick up from observing the people around them. People with impaired cognitive function cannot just pick up these skills, they need to be taught (again and again and again).  I spent three years trying to teach prepositions to my son Monty to the age of eight, using a special computer program created for other people with exactly the same difficulty. Once I started addressing cognitive function, with Bumetanide, from the age of 9, Monty figured out prepositions all by himself, without any teaching. I never even bothered to use the remaining language teaching software that I had paid $1,500 for, as a bundle, when he was four years old.  It is still sitting unopened on the shelf. 







Tuesday, 24 October 2017

Treated ID and CBS/DYRK1A in Autism and Down Syndrome

One of the most interesting concepts I have come across writing this blog is the idea of treating people with mental retardation (MR) / intellectual disability (ID). I do keep using the term MR, because 90% of the world has no idea what ID means. MR is a very precise description, which is increasingly rare these days.
I still recall several years ago going to a French-speaking neighbour’s barbecue. The French are generally very family-oriented, but quite traditional when it comes to parenting, (hence their low rates of ADHD diagnosis). At that time, Monty aged around 8, could act strangely and was rather obsessed with fire, matches and cigarette lighters. Our neighbour introduced us to his French friends and explained Monty with a brief use of the word “retardé”, which did not prompt any comments or requests for clarification. In the English language this might have been regarded as a big faux-pas; it did not bother me.  It seemed to work very well to forewarn people not to over-react to any unexpected behaviours. 
In the English language, autism has become a nice word and seems the new ADHD, with people even wanting to be diagnosed with it.  MR/ID is still something reserved for other people; it is not something most people want to be associated with. I do use the term cognitive dysfunction, which is just as explicit as MR but does not seem to upset people.
Cognitive dysfunction (MR/ID) is an inevitable consequence of more severe autism and it is just a question of degree. It is not a comorbidity, it is all part of the same package.

In Down Syndrome (DS) IQ is usually between 45 and 71 and worsens with age. MR/ID is defined as an IQ less than 70 and accounts for 2.3% of the general population. An IQ of 100 would put you in the middle of the IQ bell curve. People with DS tend to be very happy and contented, without the problematic behaviors that can occur in autism. 
The good news is that cognitive dysfunction (MR/ID) is likely to be treatable, as some readers of this blog have discovered. You just need to figure out how, which in itself is more about your perseverance than your IQ. You do not need to be an Einstein (IQ > 160), rather a marathon runner.
I just had the uncanny experience at school during the parent-teacher meetings, to be told that other class members could learn from my younger son Monty, aged 14 with autism; that he has the neatest handwriting in class, his essay had the best structure and that when his geography teacher told his assistant to skip the final question in the test (using longitude and latitude) because it was hard, the assistant said just let him try it; he was the only one to get it right. 
So from aged 8 to 14 he has gone from “retardé” to being something quite different.  The teachers do love his assistants, who are great; but he has had an assistant from the age of 4 and back then things moved forward extremely slowly. He learnt to read and write the very hard way, with a vast amount of 1:1 instruction and the school was amazed when his then assistant taught him to read; I don’t think they expected it ever to happen. By treating cognitive dysfunction pharmacologically for five years normal learning became possible and remains a big surprise to everyone.  His new English teacher knows him from back in the darker old days and seemed more shocked than surprised, after a month of teaching him. "Is this the same boy?"
For the first time at school I am being told to be proud of my younger son’s academic achievements, rather than how talented my older son is. Big brother certainly did not expect such a day and his response was along the lines of “well the others in his class must be really thick then” (like it or not, this is a typical teenage male comment). Little brother still has autism, but it is much less disabling. Big brother is currently teaching him to fence (sword fighting), which he would not have bothered to try doing until recently, because it would not have ended well. Years ago Monty did learn to ski, play basketball and soccer, but that all took a lot of effort with very patient (mostly female) instruction; he initially had no idea what to do if a ball was rolled towards him.  Last week he happily sat through the new Blade Runner film, which is nearly three hours long with the trailers. 
Perhaps there is no need for further “breakthroughs” with my Polypill therapy.  It may be good enough already.
It just seems a pity that more people with cognitive dysfunctions are not treated. There are some extremely intelligent parents with children who have severe autism, indeed an ironic twist of genetics. Some even write autism research, or indeed fund it. Even these people are not treating it.   Their fear of quackery blinds them. There certainly are quacks and there are also those who straddle the line, some of what they say is nonsense, but other ideas may not be.

Imagine having a conversation with Bill Gates, who is using his billions to use vaccines to save millions of lives in poor countries, about the possibility that in some people vaccines might trigger mitochondrial disease and autism.  Any organization talking about autism in relation to vaccines, chelation, aluminium, heavy metals etc and anyone who associates with them are in effect blacklisted.
Why does the global head of neuroscience at Novartis not attend the Autism One or TACA conferences? He does have a son with severe autism. It would be very difficult for him to apply any therapy promoted by anyone who attends these events.
Why does a Professor of Medicine from the US Ivy League apply ideas from this blog to his son, but never leave a comment? It is very clear to me why.
As our reader Roger has commented, why do some leading autism researchers still go on about vaccines? It does their interests much more harm than good. 
I think Roger could teach Dr Naviaux a thing or two about getting his Suramin research funded.  


Enhancing Cognition
The first area I came across where serious research is underway to treat MR/ID concerns RASopathies, a group of disorders that share disturbed levels of a protein called RAS. It was actually French research.
In Down Syndrome (DS) I highlighted research that aims to increase cognitive function by targeting the alpha 5 subunit of the GABAA receptor. We also saw that the same abnormal level of chloride within in cells that exists in much autism also occurs in Down Syndrome (DS); this is why the Frenchman Ben Ari has patented Bumetanide as a therapy for DS. 
In schizophrenia and bipolar there is also reduced cognitive function, but only in schizophrenia has there been much research and clinical trials to improve it. Histamine receptors were one target of this research. 

Too much or too little CBS (Cystathionine-β-synthase )
One known cause of cognitive dysfunction that has not been mentioned in my posts is CBS and since it was raised in a comment I thought it should be included.
All you need to know if you want to rule out a CBS problem is your level of homocysteine. If it is normal you do not have a problem with CBS. If homocysteine is high you have a case of Hyper-homocystinuria, which may be caused by too little CBS, or for a different reason. If you have very low levels of homocysteine (Hypo-homocystinuria) that may be caused by too much CBS and if you have Down Syndrome elevated CBS is inevitable.
Normalizing CBS is very likely to help cognition.
Cystathionine-β-synthase, also known as CBS, is an enzyme that in humans is encoded by the CBS gene. It catalyzes the first step of the transsulfuration pathway, from homocysteine to cystathionine:

L-serine + L-homocysteine    <------>     L-cystathionine + H2O


Down syndrome is a medical condition characterized by an overexpression of cystathionine beta synthase (CBS) and so a low level of homocysteine in the blood. It has been speculated that cystathionine beta synthase overexpression could be the major culprit in this disease (along with dysfunctioning of GABAA and Dyrk1a). The phenotype of down syndrome is the opposite of Hyperhomocysteinemia (described below). Pharmacological inhibitors of CBS have been patented by the Jerome Lejeune Foundation and trials are planned.


Down's syndrome (DS) or trisomy 21 is the most common genetic cause of mental retardation, and adults with DS develop Alzheimer type of disease (AD). Cystathionine beta-synthase (CBS) is encoded on chromosome 21 and deficiency in its activity causes homocystinuria, the most common inborn error of sulfur amino acid metabolism and characterized by mental retardation and vascular disease. Here, we show that the levels of CBS in DS brains are approximately three times greater than those in the normal individuals. CBS is localized to astrocytes and those surrounding senile plaques in the brains of DS patients with AD. The over-expression of CBS may cause the developmental abnormality in cognition in DS children and that may lead to AD in DS

It is a French foundation that is funding research is develop CBS inhibitors to improve cognition in Down Syndrome.


NovAliX will use its expertise and capabilities in medicinal chemistry and structural biology to develop small molecule lead candidates targeting the cystathionine-beta-synthase (CBS). Indeed inhibition of CBS over-expression has been associated with restoration of cognitive impairment in animal models afflicted with trisomy. 

People with DS have a low incidence of coronary atherosclerotic disease (CAD), which would seem to be linked to their low level of homocysteine (high CBS), but their high level of DYRK1A (see later) may be the cause of their early onset Alzheimer’s. 
Some background on homocystinuria, courtesy of Wikipedia:- 

Classical homocystinuria, also known as cystathionine beta synthase deficiency or CBS deficiency, is an inherited disorder of the metabolism of the amino acid methionine, often involving cystathionine beta synthase.
Homocystinuria represents a group of hereditary metabolic disorders characterized by an accumulation of the amino acid homocysteine in the serum and an increased excretion of homocysteine in the urine.
Signs and symptoms of homocystinuria that may be seen include the following:


The term homocystinuria describes an increased excretion of homocysteine in urine (and incidentally, also an increased concentration in plasma). The source of this increase may be one of many metabolic factors, only one of which is CBS deficiency. Others include the re-methylation defects (cobalamin defects, methionine sythase deficiency, MTHFR) and vitamin deficiencies (cobalamin (vitamin B12) deficiency, folate (vitamin B9) deficiency, riboflavin deficiency (vitamin B2), pyridoxal phosphate deficiency (vitamin B6)). In light of this information, a combined approach to laboratory diagnosis is required to reach a differential diagnosis.  

DYRK1A
You may have noticed that DYRK1A was mentioned as another cause of cognitive loss in Down Syndrome.  DYRK1A is yet another autism gene; it encodes an enzyme that is important in how the brain develops. Too much DYRK1A also leads to reduced levels of homocysteine. 
An OTC DYRK1A inhibitor exists today, epigallocatechin gallate (EGCG).



DYRK1A is important in neuronal development and function, and its excessive activity is considered a significant pathogenic factor in Down syndrome and Alzheimer's disease. Thus, inhibition of DYRK1A has been suggested to be a new strategy to modify the disease. Very few compounds, however, have been reported to act as inhibitors, and their potential clinical uses require further evaluation. Here, we newly identify CX-4945, the safety of which has been already proven in the clinical setting, as a potent inhibitor of DYRK1A that acts in an ATP-competitive manner. The inhibitory potency of CX-4945 on DYRK1A (IC50=6.8 nM) in vitro was higher than that of harmine, INDY or proINDY, which are well-known potent inhibitors of DYRK1A. CX-4945 effectively reverses the aberrant phosphorylation of Tau, amyloid precursor protein (APP) and presenilin 1 (PS1) in mammalian cells. To our surprise, feeding with CX-4945 significantly restored the neurological and phenotypic defects induced by the overexpression of minibrain, an ortholog of human DYRK1A, in the Drosophila model. Moreover, oral administration of CX-4945 acutely suppressed Tau hyperphosphorylation in the hippocampus of DYRK1A-overexpressing mice. Our research results demonstrate that CX-4945 is a potent DYRK1A inhibitor and also suggest that it has therapeutic potential for DYRK1A-associated diseases

Neurodevelopmental alterations and cognitive disability are constant features of Down syndrome (DS), a genetic condition due to triplication of chromosome 21. DYRK1A is one of the triplicated genes that is thought to be strongly involved in brain alterations. Treatment of Dyrk1A transgenic mice with epigallocatechin gallate (EGCG), an inhibitor of DYRK1A, improves cognitive performance, suggesting that EGCG may represent a suitable treatment of DS. Evidence in the Ts65Dn mouse model of DS shows that EGCG restores hippocampal development, although this effect is ephemeral. Other studies, however, show no effects of treatment on hippocampus-dependent memory. On the other hand, a pilot study in young adults with DS shows that EGCG transiently improves some aspects of memory. Interestingly, EGCG plus cognitive training engenders effects that are more prolonged. Studies in various rodent models show a positive impact of EGCG on brain and behavior, but other studies show no effect. In spite of these discrepancies, possibly due to heterogeneity of protocols/timing/species, EGCG seems to exert some beneficial effects on the brain. It is possible that protocols of periodic EGCG administration to individuals with DS (alone or in conjunction with other treatments) may prevent the disappearance of its effects.


Conclusion

Understanding emerging therapies that treat various types of MR/ID, and also the various types of dementia, should unlock interesting avenues to raise cognitive function in many types of autism.
Homocysteine levels are very easy to measure. 
Because the gene miss-expression in Down Syndrome (DS) is fully understood, it makes sense that treatment is more advanced than in autism, which is so heterogenous. There are a lot of people in the world with DS and so there is a big market for drug makers.
The potential drug therapies to improve cognition in Down Syndrome (DS) appear to be:- 

·        Basmisanil, a negative allosteric modulator of α5 subunit-containing GABAA receptors. It appears that sodium benzoate may have a similar effect.

·        Bumetanide, an NKCC1 inhibitor

·        Potassium bromide, Br- displaces Cl- to lower intracellular Cl-

·        CBS inhibitor

·        DYRK1A inhibitor, like Epigallocatechin gallate (EGCG), but a more potent inhibitor like CX-4945 (Silmitasertib) might be better.

There is mouse model research to show that a single dose just after birth of a drug that stimulates the sonic hedgehog signaling pathway results in a "normal" adult brain.

The risk of Down Syndrome (DS), caused by a third copy of chromosome 21 (trisomy 21), rises rapidly with increasing maternal age, nonetheless the number of births is stable to falling in most developed countries, due to increased prenatal testing and termination of pregnancy for fetal anomaly (TOPFA). TOPFA is not practiced in countries like Poland and Ireland. In Denmark screening has long been free and TOPFA has risen to 98%. In the UK two thirds of mothers opt for their free DS screening and 90% of those who test positive, opt for their free TOPFA. The one third letting nature take its course are probably mainly younger mothers.
In Catholic countries you have both extremes - in Cork, Ireland DS is present 30 times per 10,000 births, but in Zagreb Croatia it is just 6 per 10,000. In the US the CDC say it 14, while in the UK it is 10.  In South Africa 20 cases of DS occur per 10,000 births; mothers are younger than in Ireland.
In developed countries, the natural prevalence of DS looks to be 0.3%, which is the same as the incidence of strictly defined autism (SDA), which I estimated in an earlier post to be 0.3%. It is just that in developed countries most people with DS are never born. 

I would have thought CX-4945 should be trialed by some clever Alzheimer's researcher and indeed for any Tauopathy. In the meantime perhaps Grandad should drink a lot of green tea to get his dose of EGCG.