Showing posts with label Niclosamide. Show all posts
Showing posts with label Niclosamide. Show all posts

Thursday, 22 June 2023

Autism Research Merry-go-round Keeps Turning


Today’s post again shows that many issues raised in previous posts keep on coming back  is that good news? Only you can decide.

I start with the “old chestnut” (English idiom to imply “a tired old story”) of the Autism Tsunami. 

Then we see what has come up in the world of autism interventions in the research in the last 3 weeks, most of which regular readers will already be aware of.

·        Autism Tsunami – real or not?

·        Vitamin D

·        Bumetanide

·        Ibudilast

·        Niclosamide

·         Non-invasive brain stimulation

·         Simvastatin 

I noted the research about autism incidence coming from Northern Ireland because it was published in the Belfast News Letter.  These days it has a tiny subscription, but I am one of those who know it is the world's oldest English-language general daily newspaper still in publication, having first been printed in 1737. In 1972 a bomb warning was called in to the paper's office and, as people evacuated, an explosion went off nearby killing several people and injuring many more. Back in the early 1990s, when some people in Northern Ireland were still blowing up others with bombs, I made a visit to Northern Ireland to meet the management of this newspaper. 

Their recent article on autism incidence is very well researched considering how only about 8,000 copies are published. Keep up the good work!

Idea that 5% of all Northern Ireland's children are autistic is 'a fantasy' claims international expert

Professor Laurent Mottron was speaking to the News Letter following a claim that the rate of autism in Northern Ireland is double the rate in the rest of the UK.

Back in 2019 Prof Mottron had authored a report warning about a tsunami of over-diagnosis, saying that soon "the definition of autism may get too vague to be meaningful, trivializing the condition"

“If this trend holds, the objective difference between people with autism and the general population will disappear in less than 10 years," he had said then – and has now indicated that this “fuzziness” is what’s helping swell the numbers in Northern Ireland.

Meanwhile Jill Escher, the president of the National Council on Severe Autism, takes a different view.

She says that evidence indicates the "skyrocketing" rate of autism in Northern Ireland is real, adding: "It boggles my mind that it is not the subject of the highest possible alarm and inquiry."

"One in 20 children in Northern Ireland of school age has a diagnosis of autism," he told MPs.

"[It is] one in 57 in the rest of the UK. The need in Northern Ireland is significantly different."

To put that in perspective, that would mean 5% of Northern Irish children are diagnosed with autism, compared with 1.8% in the rest of the UK.

Prof Mottron, a psychiatrist based at Montreal University, told the News Letter "numbers such as 5% are pure fantasy... these numbers correspond to the part of the general population which has less overt socialisation, which has minimally to do with prototypical autism". 

There is a "current fuzziness of autism diagnosis and over-inclusivity," he said, leading to "a situation of perfect confusion between autistic traits and prototypical autism" (that is, mixing up people who exhibit some tendencies of autistic people with people who actually have the full-blown condition). 

"The scientific 'quasi consensus' would be around 1% everywhere on the planet,” he added.


So on one side we have Jill Escher and her NCSA and on the other we have a French/Canadian researcher.  This time Laurent Mottron but in my blog posts I quoted Éric Fombonne.

A paper that was mentioned both in my blog and critiqued by Jill about autism incidence and cost just got retracted.  In reality a better word is “cancelled.”  The 3 authors are very much in the politically incorrect camp of the autism debate.

I was surprised it ever got published.  

Controversial ‘cost of autism’ paper retracted 

Citing methodological issues and undeclared conflicts of interest, an autism journal has retracted a paper that forecast the prevalence and cost of autism.

The retraction note, posted last week, comes two years after Spectrum reported on backlash surrounding the paper, which was published in the Journal of Autism and Developmental Disorders in July 2021. A month after publication, the journal added an editor’s note that the study was under investigation because of criticisms of its conclusions. 

“I am glad to see that it was retracted, although at a pace that maybe is a bit frustrating in terms of how long it took. But it was the right choice,” says Brittany Hand, associate professor of health and rehabilitation sciences at Ohio State University in Columbus.

Outside experts who reviewed the paper on the journal’s behalf found that it misrepresented the rise in autism diagnoses and gave “insufficient attention” to some potential causes of the increase, such as improved surveillance and changes to the diagnostic criteria. The authors also used “higher estimates and assumptions that inflated costs,” according to the retraction note.

The authors — Mark Blaxill, Toby Rogers and Cynthia Nevison — all disagree with the journal’s decision, the note also says.

The cancelled paper is here:-

Autism Tsunami: the Impact of Rising Prevalence on the Societal Cost of Autism in the United States


I assume Blaxill was the driving force behind all the math, because he is the ex- management consultant, with a son with severe autism that his dad attributes to vaccines.

What I found bizarre in their paper was that they has a prevention scenario, based on what they think has already happened in rich parts of California, where they think autism incidence is falling.  It is not falling, all that is happening is that wealthy Californians are paying for treatment using insurance or their own money, and no longer burdening the State.

The “rainbow” researchers that wanted the paper retracted think that preventing autism is akin to eugenics and Dr Mengele. According to Peter, treating autism is good, while Dr Josef Mengele, byname Todesengel (German: “Angel of Death”) was as bad as you can get.    

Jill Escher and her NCSA think that you cannot prevent autism.  According to Peter, you can both minimize the incidence and severity of autism. 

A bugbear of our reader Tanya is that the NCSA have a pet hate of facilitated communication and in particular the rapid prompting method (RPM). This method worked for Tanya’s son and it opened the door to independent, un-facilitated communication. 

Always keep an open mind.




“our Prevention scenario is based on real rates observed among wealthy white and Asian children in the California DDS.  Severe ASD prevalence has flattened and even declined among these children since birth year 2000, suggesting that wealthy parents have been making changes that effectively lower their children’s risk of developing ASD. The Prevention scenario assumes that these parental strategies and opportunities already used by wealthy parents to lower their children’s risk of ASD can be identified and made available rapidly to lower income children and ethnic minorities, who are currently experiencing the most rapid growth in ASD prevalence”


New Paper Makes Case that Autism Tsunami May Threaten American Economy

A major weakness in the analysis was the “Prevention Scenario” in which future costs were projected based on “what might be possible if strategies for reducing ASD risk are identified and addressed in the near future.” As I think everyone knows, at this time there is no way to prevent autism. But the authors use the observation that autism in the DDS is declining among wealthier white families, and thus “suggesting that wealthy parents have been making changes that effectively lower their children’s risk of developing ASD.” No, it’s far more likely that wealthier families are not entering their children into the system because they access services through insurance and school districts instead.


Vitamin D as a cause of autism has been discussed for decades.  As the title below puts it – a never-ending story. Our reader Seth Bittker even wrote a paper about it. He later wrote a paper about the use Acetaminophen/Paracetamol in children under two as a risk factor in developing autism. Good work Seth!


Maternal Vitamin D deficiency and brain functions: a never-ending story 

A large number of observational studies highlighted the prevalence rates of vitamin D insufficiency and deficiency in many populations as pregnant women. Vitamin D is well known to have a crucial role in differentiation and proliferation, as well as neurotrophic and neuroprotective actions in brain. Then, this micronutrient can modulate the neurotransmission and synaptic plasticity. Recent results from animal and epidemiological studies indicated that maternal vitamin D deficiency is associated with a wide range of neurobiological disease including autism, schizophrenia, depression, multiple sclerosis or developmental defect. The aim of this review is to provide a state of the art on the effect of maternal vitamin D deficiency on brain functions and development.

4.2.2. Autism

Autism spectrum disorder (ASD) is a complex neurodevelopmental disease with repetitive behaviour and difficulties in social interaction, communication and learning. Several murine studies and cohorts have demonstrated that early exposure to low levels of VD during pregnancy could be a risk factor for ASD. In 2019, Ali et al. aimed to find out the impact of a maternal VDD on early postnatal, adolescent and adult offspring. By assessing righting reflex and negative geotaxis, they found out that the pups from deficient dams showed a delay in their motor development. P12 rats from deficient females also exhibited increased ultrasound vocalization indicating an alteration in their vocal communication. Adolescent and young adult rats displayed an altered stereotyped repetitive behaviour as they had a reduced digging behaviour. Adolescent rats had less social interaction with longer latency to interact, which was not found in adult rats; however, adults were more hyperactive but showed no anxiety like behaviour.  In another animal study, maternal VDD induced an increase in the vocalizations of the pups accompanied with a decrease in cortical FoxP2, decrease in social behaviour and impaired learning and memory were observed in adult males (Table 1). Using data from the Stockholm youth cohort, Magnusson et al. examined a population of 4-17-year-old children exposed to low levels of VD during gestation and was able to report a positive association between maternal VDD and ASD. Analysing the same cohort, Lee et al. suggested that high levels of VD during pregnancy were associated with a moderate decrease in risk of ASD in the offspring. A prospective study of a multi-ethnic cohort in the Netherlands (generation R study) has also shown an association between maternal mid-gestation VDD and a two-fold increase in the risk of autism in children (Table 2). Interestingly, VD supplementation seems to clinically improve ASD symptoms of affected children.


People do associate this blog with Bumetanide.  Yet another paper has been published showing the benefits of this therapy for autism.


EEG-based brain connectivity analysis in autism spectrum disorder: Unravelling the effects of bumetanide treatment 



·        We investigated the nonlinear brain connectivity and topological changes in brain networks of people with autism spectrum disorders (ASD) after a three-month course of bumetanide treatment.

·        We found statistically significant differences between pre and post intervention in the connectivity patterns using repeated measures analysis of variance (ANOVA).

·        We found that the number of strong connections in response to sad image stimuli seem to be less compared with that of the other two stimuli, especially in the central area.

·        We found that the changes in brain connectivity between pre and post intervention is more significant in response to sad image stimuli.


Emerging evidence suggests that cognitive impairment associated with brain network disorders in people with autism could be improved with medications such as bumetanide. However, the extent to which bumetanide is effective in improving brain function in these individuals has not been adequately studied. The main purpose of this study is to investigate the nonlinear brain connectivity and topological changes in brain networks of people with autism spectrum disorders (ASD) after a three-month course of bumetanide treatment. We used electroencephalography (EEG) data of nine participants recorded during the face emotion recognition activity in two stages before and after bumetanide treatment. Brain connectivity matrix was calculated using a neural network-based estimator. Graph criteria and statistical tests have been used to determine the effects of bumetanide treatment on children and adolescents with autism. Bumetanide treatment significantly alters the brain connectivity networks based on stimuli type. Differences in brain connectivity related to the sad stimuli are more significant. The most of the significant changes of the strength graph metric was in the occipital electrodes and electrodes related to the right hemisphere. These results suggest that bumetanide may affect effective connectivity and be used a promising treatment for improving social interactions in patients with autism. It also suggests that brain connectivity patterns can be considered as a neural marker to be used in the development of new therapies. 

I have also covered in sometimes painful details the potential to treat autism and increase cognitive function using PDE (Phosphodiesterase) inhibitors. One of our psychiatrist readers is a huge fan of Pentoxifylline and takes it himself.

I was recently asked how to obtain Ibudilast.  It is approved in Japan as an asthma drug. Sometimes it is called Ketas and you can get it from an “International Pharmacy” in Germany/Switzerland if you have a prescription. 

I also wrote about repurposing Roflumilast, which as Daxas is approved all over the world as a therapy for severe asthma (COPD). This drug at a 1/5th dose has been patented as a cognitive enhancer.


Phosphodiesterase inhibitor, ibudilast alleviates core behavioral and biochemical deficits in the prenatal valproic acid exposure model of autism spectrum disorder


Autism spectrum disorder (ASD) is categorized as a neurodevelopmental disorder, presenting with a variety of aetiological and phenotypical features. Ibudilast is known to produce beneficial effects in several neurological disorders including neuropathic pain, multiple sclerosis, etc. by displaying its neuroprotective and anti-inflammatory properties. Here, in our study, the pharmacological outcome of ibudilast administration was investigated in the prenatal valproic acid (VPA)-model of ASD in Wistar rats.


Autistic-like symptoms were induced in Wistar male pups of dams administered with Valproic acid (VPA) on embryonic day 12.5. VPA-exposed male pups were administered with two doses of ibudilast (5 and10 mg/kg) and all the groups were evaluated for behavioral parameters like social interaction, spatial memory/learning, anxiety, locomotor activity, and nociceptive threshold. Further, the possible neuroprotective effect of ibudilast was evaluated by assessing oxidative stress, neuroinflammation (IL-1β, TNF-α, IL-6, IL-10) in the hippocampus, % area of Glial fibrillary acidic protein (GFAP)-positive cells and neuronal damage in the cerebellum.

Key findings: Treatment with ibudilast significantly attenuated prenatal VPA exposure associated social interaction and spatial learning/memory deficits, anxiety, hyperactivity, and increased nociceptive threshold, and it decreased oxidative stress markers, pro-inflammatory markers (IL-1β, TNF-α, IL-6), and % area of GFAP-positive cells and restored neuronal damage.


Ibudilast treatment has restored crucial ASD-related behavioural abnormalities, potentially through neuroprotection. Therefore, benefits of ibudilast administration in animal models of ASD suggest that ibudilast may have therapeutic potential in the treatment of ASD.



I have also written widely about repurposing certain anti-parasite medicines to treat autism. This is not because I think parasites cause autism, it is the secondary modes of action.



Repurposing Niclosamide as a plausible neurotherapeutic in autism spectrum disorders, targeting mitochondrial dysfunction: a strong hypothesis



Autism Spectrum Disorders (ASD) are a complex set of neurodevelopmental manifestations which present in the form of social and communication deficits. Affecting a growing proportion of children worldwide, the exact pathogenesis of this disorder is not very well understood, and multiple signaling pathways have been implicated. Among them, the ERK/MAPK pathway is critical in a number of cellular processes, and the normal functioning of neuronal cells also depends on this cascade. As such, recent studies have increasingly focused on the impact this pathway has on the development of autistic symptoms. Improper ERK signaling is suspected to be involved in neurotoxicity, and the same might be implicated in autism spectrum disorders (ASD), through a variety of effects including mitochondrial dysfunction and oxidative stress. Niclosamide, an antihelminthic and anti-inflammatory agent, has shown potential in inhibiting this pathway, and countering the effects shown by its overactivity in inflammation. While it has previously been evaluated in other neurological disorders like Alzheimer’s Disease and Parkinson’s Disease, as well as various cancers by targeting ERK/MAPK, it’s efficacy in autism has not yet been evaluated. In this article, we attempt to discuss the potential role of the ERK/MAPK pathway in the pathogenesis of ASD, specifically through mitochondrial damage, before moving to the therapeutic potential of niclosamide in the disorder, mediated by the inhibition of this pathway and its detrimental effects of neuronal development.


Note that in earlier posts I explored RASopathies as potentially treatable types of intellectual disability (ID). We also have RAS-dependent cancers as a discrete treatable sub-type of cancer.

The ERK/MAPK pathway is known to interact with multiple genes that have been implicated in autism, and genome-wide association analysis of the same have supported these findings. As such, a dysregulation of this pathway has been found to result in many CNS disorders, including ASD-related syndromes, in many studies. These syndromes are collectively known as Rasopathies, due to the fact that the affected genes include those encoding for elements which function together with Ras, a G-protein responsible for activating ERKs (Levitt and Campbell 2009; Tidyman and Rauen 2009). It has been found that ASD is linked to the occurrence of many Rasopathies, and there have been multiple reports suggesting the possible relation of ERK/MAPK pathway defects with the incidence of ASD (Vithayathil et al. 2018; Aluko et al. 2021)⁠⁠. Moreover, a detailed study has found that single nucleotide polymorphisms (SNPs) in the ERK/MAPK-related genes are more common in subjects presenting with idiopathic ASD.


Niclosamide is an FDA-approved antihelminthic drug which is routinely used to treat tapeworm infections by inhibiting their mitochondrial oxidative phosphorylation and ATP production. In addition, it has long been known to have significant immunomodulating activity, and has been shown to inhibit a number of signaling pathways, including the Wingless-related integration site (Wnt)/β-catenin, nuclear factor kappa B (Nf-κB), signal transducer and activator of transcription 3 (STAT3), and mammalian target of rapamycin (mTOR) (Chen et al. 2018). However, while these targets are known to be rather well-characterized in terms of the effect that niclosamide has on them, there are also other targets, including the phosphoinositode 3 kinase/Akt (PI3K/Akt) and ERK/MAPK pathways, that are seen to be downregulated by the agent. Hence, given the possible relation of the ERK pathway in autism, there has been interest in the potential role of niclosamide in the management of the prognosis of ASD. This article aims to discuss the possible therapeutic benefit of niclosamide in the treatment of autism spectrum disorders.


Now I know that parents like the idea of treating autism with various gadgets you can strap on to your head  things like Transcranial Magnetic Stimulation (TMS). I must say I liked my old post on Photobiomodulation/cold laser/low level laser therapy.

Epiphany: Low Level Laser Therapy (LLLT) for Autism – seems to work in Havana

From China we have a new round-up paper, but the full text does not yet seem to be ready.


Non-invasive brain stimulation for Patient with Autism A Systematic Review and Meta-Analysis

Objective: To comprehensively evaluate the efficacy of non-invasive brain stimulation (NIBS) in patients with autism spectrum disorder (ASD) in randomized controlled trials (RCT),providing reference for future research on the same topic.

Methods:Five databases were searched (Pubmed,Web of science,Medline,Embase and Cochrane library) and track relevant references,Meta-analysis was performed using RevMan 5.3 software.

Results: Twenty-two references(829 participants) were included. The results of meta analysis showed that, NIBS had positive effects on repetitive and stereotypical behaviors, cognitive function and executive function in autistic patients. Most of the included studies had a moderate to high risk of bias, Mainly because of the lack of blinding of subjects and assessors to treatment assignment, as well as the lack of continuous observation of treatment effects.

Conclusions: Available evidence supports an improvement in some aspects of NIBS in patients with ASD. However, due to the quality of the original studies and significant publication bias, these evidences must be treated with caution. Further large multicenter randomized double-blind controlled trials and appropriate follow-up observations are needed to further evaluate the specific efficacy of NIBS in patients with ASD.

Unfortunately, the Chinese have concluded that most of these studies are not reliable. So no laser for me to go out and buy just yet.

No need to dent your bank balance with the next therapy.  We are back to one of the world's most prescribed and therefore affordable drugs, its Simvastatin (Zocor). 

There is masses of information in this blog about the potential to treat sub-types of autism with Atorvastatin, Simvastatin or Lovastatin. They are each slightly different.


Effect of simvastatin on brain-derived neurotrophic factor (BDNF)/TrkB pathway in hippocampus of autism rat model 

Purpose: To study the effect of simvastatin on behavioral performance in a rat model of autism, and its effect on hippocampal brain-derived BDNF-TrkB pathway. 

Methods: Twelve rats with valproic acid (VPA)-induced autism were randomly divided into model group and simvastatin group, while six healthy rats served as normal control group. Rats in the simvastatin group received the drug (5 mg/kg) via i.p. route, while rats in model group and normal control group were injected with equivalent volume of normal saline in place of simvastatin. Capacity for interaction and repetitive stereotyped behavior, as well as results of Morris water maze test were determined for each group. The expressions of BDNF-TrkB proteins were assayed with immunoblotting. 

Results: The frequencies of sniffing normal saline, alcohol and rat urine were significantly higher in model and simvastatin rats than in normal rats, but they were significantly lower in simvastatin-treated rats than in model rats (p < 0.05). There was higher duration of turning, jumping and grooming in the model group and simvastatin group than in the normal rats, but the duration was significantly reduced in simvastatin rats, relative to model rats. Escape latency times was significantly longer in model and simvastatin rats than in controls, but number of target quadrant crossings was significantly reduced. However, escape latency time was lower in simvastatin rats than in model rats, but number of target quadrant crossings was significantly higher. The model and simvastatin rats had down-regulated levels of BDNF and TrkB protein, relative to control rats, but there were markedly higher levels of these proteins in simvastatin-treated rats than in model rats. 

Conclusion: Simvastatin improves the behavioral performance of autistic rats by regulating BDNF/TrkB signal axis. This finding may be useful in the development of new drugs for treating autism.



What is the conclusion? Well, I could say give up reading the new research and just read my old posts.  It seems you are not going to miss very much.

Of course, back in the real world, it is true that things do take time to change and after a few decades the leap might be taken from the research to the doctor’s office.

There already is plenty of research on the causes of autism and what steps can be taken by those who want to treat aspects of it.  It is far from a complete picture, but it is enough to get started.  There are no guarantees of success, but if you want 100% certainty you will wait forever.

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.


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. 


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.