A RORα Agonist for Autism?

Today’s post is again about RORα, which was suggested to be a nexus where different biological dysfunctions that lead to autism may converge. I think you can consider RORα like a dimmer switch on your lights, you need to adjust the brightness to give the effect you want.

Fine tuning RORα to tune autism gene expression

I recently came across some research where the scientist clearly has the same idea. He has been working on a synthetic RORα/γ agonist for some years and has investigated its use as both a cancer therapy and an autism therapy.

I have become rather interested in cancer therapies because there are so many overlaps between what can lead to cancer and what exists in autism. The big research money is of course in cancer research.

Tumor suppressor genes/proteins like PTEN and p53 have been shown to be disturbed in autism, as is Bcl-2. The Bcl-2 family of proteins regulate cell death (apoptosis); some members induce cell death and other inhibit it; the balance is important.

Generally it seems that most people with autism might benefit from more PTEN and Bcl-2. 

Therapeutic Effect of a Synthetic RORα/γ Agonist in an Animal Model of Autism  

Autism is a developmental disorder of the nervous system associated with impaired social communication and interactions as well excessive repetitive behaviors. There are no drug therapies that directly target the pathology of this disease. The retinoic acid receptor-related orphan receptor α (RORα) is a nuclear receptor that has been demonstrated to have reduced expression in many individuals with autism spectrum disorder (ASD). Several genes that have been shown to be downregulated in individuals with ASD have also been identified as putative RORα target genes. Utilizing a synthetic RORα/γ agonist, SR1078, that we identified previously, we demonstrate that treatment of BTBR mice (a model of autism) with SR1078 results in reduced repetitive behavior. Furthermore, these mice display increased expression of ASD-associated RORα target genes in both the brains of the BTBR mice and in a human neuroblastoma cell line treated with SR1078. These data suggest that pharmacological activation of RORα may be a method for treatment of autism. 

The RORs have been linked to autism in human in several studies. In 2010, Nguyen and co-workers reported that RORα protein expression was significantly reduced in the brains of autistic patients and this decrease in expression was attributed to epigenetic alterations in the RORA gene.¹⁵ Additional work from this group demonstrated that multiple genes associated with autism spectrum disorder are direct RORα target genes and suggested that reduction of RORα expression results in reduced expression of these genes associated with the disorder leading to the disease.¹⁶ Independently, Devanna and Vernes demonstrated that miR-137, a microRNA implicated in neuropsychiatric disorders, targets a number of genes associated with autism spectrum disorder including RORA.¹⁷ There are also additional links between RORα and autism. Deficiency of Purkinje cells is one of the most consistently identified neuroanatomical abnormalities in brains from autistic individuals^18,19 and RORα is critical in development of the Purkinje cells.²⁰⁻²³ Significant circadian disruptions have also been recognized in autistic patients,²⁴⁻²⁷ and RORs play a critical role in regulation of the circadian rhythm.^7,28 Additionally, the staggerer mouse displays behaviors that are associated with autism including abnormal spatial learning, reduced exploration, limited maze patrolling, and perseverative behavior relative to wt mice.²⁹⁻³³

SR1078 is a relatively low potency compound with limited RORα efficacy (3–5 μM EC₅₀E_max ∼ 40%),⁸ but the efficacy compares favorably to other classes of compounds that have been optimized such as a 38% decrease in the same model induced by the mGluR5 allosteric modulator GRN-529⁴⁹ and a 47% reduction by the mGluR5 antagonist MPEP.⁴⁵ Both of these compounds have been optimized and display high potency (single digit nanomolar range at mGluR5) and strong efficacy.^53,54 Thus, we believe that focused optimization of RORα ligands will provide compounds that will have improved efficacy in this model. It should also be noted that SR1078 has both RORα and RORγ agonist activity⁸ and a RORα selective agonist has not yet been developed. Thus, it is possible that the RORγ activity of this compound may also play a role in its efficacy in this model of autism. In summary, we have demonstrated that a synthetic RORα/γ agonist is able to increase the expression of key genes whose decrease in expression is associated with ASD both in cell culture and in vivo. Furthermore, the agonist decreases repetitive behavior in an animal model of autism suggesting that it is possible that ROR agonists may hold utility in treatment ASD. 

Regulation of p53 Stability and Apoptosis by a ROR Agonist

Activation of p53 function leading to cell-cycle arrest and/or apoptosis is a promising strategy for development of anti-cancer therapeutic agents. Here, we describe a novel mechanism for stabilization of p53 protein expression via activation of the orphan nuclear receptor, RORα. We demonstrate that treatment of cancer cells with a newly described synthetic ROR agonist, SR1078, leads to p53 stabilization and induction of apoptosis. These data suggest that synthetic ROR agonists may hold utility in the treatment of cancer.  

Levels of Bcl-2 and P53 Are Altered in Superior Frontal and Cerebellar Cortices of Autistic Subjects 

Results showed that levels of Bcl-2 decreased by 38% and 36% in autistic superior frontal and cerebellar cortices, respectively when compared to control tissues. By the same token, levels of P53 increased by 67.5% and 38% in the same brain areas in autistic subjects vs. controls respectively. Calculations of ratios of Bcl-2/P53 values also decreased by 75% and 43% in autistic frontal and cerebellar cortices vs. controls respectively. The autistic cerebellar values were significantly reduced (p < 0.08) vs. control only. There were no significant differences in levels of β-actin between the two groups. Additionally, there were no correlations between Bcl-2, P53, and β-actin concentrations vs. age or PMI in either group.

These results confirm and extend previous data that levels of Bcl-2 and P53 are altered in three important brain tissues, i.e. frontal, parietal, and cerebellar cortices of autistic subjects, alluding to deranged apoptotic mechanisms in autism.  

Conclusion

Increasing PTEN and Bcl-2 is already part of my Polypill, via the use of Atorvastatin.

There are of course many other genes miss-expressed in autism and we cannot give a drug for each one. We need to identify a handful of nexus, where multiple anomalies can be resolved with a single intervention.

It is good that Thomas Burris, the lead researcher, has been working on SR1078 for at least 6 years, let’s hope he continues to persevere.

I think it highly likely that some types of autism will need the opposite therapy, a RORα antagonist.

My method of attempting to modulate RORα will be different. I come back to my earlier gross simplification of autism :- 

As we have seen in earlier posts, the hormonal dysfunction, this time the balance between testosterone and estradiol, has a direct effect on RORα (and vice versa).

The schematic illustrates a mechanism through which the observed reduction in RORA in autistic brain may lead to increased testosterone levels through downregulation of aromatase. Through AR, testosterone negatively modulates RORA, whereas estrogen upregulates RORA through ER.

androgen receptor = AR 

estrogen receptor = ER

As you might know, many hormones are interrelated, so what are thought of as male/female sex hormones have much wider effects. They impact growth hormones and play a big role in calcium metabolism. They also affect serotonin.

We know that in most autism aromatase is reduced, estradiol is reduced and that there is reduced expression of estrogen receptor beta.

In the ideal world it might indeed be best to use an agonist or antagonist to fine tune RORα.

We have a chicken and the egg situation. Is RORα out of tune in autism because the hormones are disturbed, or vice versa?

We do know that hormones generally have feedback loops, but we also know that increasing a hormone like estradiol via obesity is not fully matched by a corresponding reduction in aromatase. So it looks highly plausible that you can tune RORα via estradiol, and that this could be a long term strategy, not just a short term strategy.

In the case of people with low T3 thyroid hormone centrally (in the brain), giving exogenous T3 may help initially, but in the long term it does not because feedback loops to the thyroid will reduce production of the pro-hormone T4. In the extreme you will make the thyroid gland shut down, this does happen to people using thyroid hormones for depression and even weight loss. 

T3 is quite commonly prescribed by alternative practitioners in the US for autism and also for depression in older people. In Europe this hormone is rarely even available. 

Many phytoestrogens are used as OTC autism therapies. These are dietary estrogens that are structurally similar to the human hormone estradiol and so produce estrogen-like effects. They include soy products, fenugreek, kudzu, EGCG etc.

Under-expression (Haploinsufficiency) of ARID1B in Autism and Corpus Callosum Abnormalities

People keep telling me that my blog is too complicated; compared to the literature it really is not. If your child has a disabling condition you really should be willing to invest all the time needed to learn about it, rather than be a passive bystander.

I think you can investigate even complex sounding genetic disorders without being an expert, which is what happens in today’s post.  

Are there 20,000 types of jeans?

As readers may recall, humans only have about 20,000 genes, far less than originally was thought. Each gene provides the instructions to make one thing, usually a protein.

For the great majority of genes we have two copies, one from Mum and one from Dad. Mitochondrial genes all come from Mum.

These genes are stored on chromosomes (like recipe books).

For 22 of these recipe books you have two copies, so if one page got damaged at least you have an undamaged version from the other book.

The 23rd pair of books is special because while females have two copies, males do not. This is the X chromosome and if a male has a problem on any page in this little book, he has a big problem, while his sister has less of a problem, because she has a spare copy. The male has a Y chromosome in place of a second copy of X. 

Examples of problems on the X chromosome:-

·        The MECP2 gene is on the X chromosome and when there is one working copy and one mutated version you have Rett syndrome and you must be female. If you were male with one mutated version you cannot survive.

·        In Fragile X syndrome a problem with the FMR1 gene means not enough not enough fragile X mental retardation protein (FMRP), which is required for normal development of the connection between neurons. Females would normally have a clean spare copy of the FMR1 gene and so show much less severe symptoms that a male with Fragile X.

Problems on chromosomes 1 to 22:-

If you have a problem in the first 22 chromosomes (recipe books), boys and girls are equal. If one page got damaged you can always look up the recipe in the other book.

In case one gene got mutated but the other copy is fine, things can work out just fine, in which case it is called haplosufficiency. You get to make enough of that protein.

In some cases you really need to use that recipe a lot; that particular protein is in big demand. One copy of that gene just is not enough. This is called  haploinsufficiency.

In most cases when the gene has a problem, it just fails to produce the intended protein. In some cases it actually produces a mutated protein, which can be worse than no protein. 

Pitt Hopkins

In Pitt Hopkins Syndrome there is a problem on chromosome 18, where you find the TCF4 gene. Not enough expression of TCF4 means not enough Transcription Factor 4;  this is an example of haploinsufficiency.

Now the reason why these rare conditions are important to many other people is that they not only affect people who happened to have a random mutation and hence a severe deficit of the protein; moderately reduced transcription of this gene, for any reason, can also result in troubling symptoms.

So in the case of the Pitt Hopkins and the gene TCF4, as was pointed out to me recently, reduced expression is a feature of some MR/ID and indeed schizophrenia. 

The Intellectual Disability and Schizophrenia Associated Transcription Factor TCF4 Is Regulated by Neuronal Activity and Protein Kinase A 

Instead of just a tiny number of people with Pitt Hopkins, you can see that upregulating TCF4 expression could help a lot of people.

It appears that people with Pitt Hopkins have a “clean copy” of TCF4, so it is just a case of making it work a little harder. There are ways being researched to achieve just that.

I suspect people with schizophrenia have two “clean copies” of TCF4, but for some reason have a deficiency of the protein encoded by it.

In the above paper it was shown that Protein Kinase A (PKA) plays a key role in regulating what your TCF4 gene is producing.

We have come across PKA before in this blog and we know that in regressive autism there can be a deficit of PKA. There is also PKB and PKC. All three are very important, but complicated. 

Brain Region–Specific Decrease in the Activity and Expression of Protein Kinase A in the Frontal Cortex of Regressive Autism

Without going into all the details you can see that if someone with Pitt Hopkins has a lack of PKA, like those with regressive autism, then he will struggle to make the most of his good copy of the gene TCF4.

It all gets very complicated, but PKA is controlled by something called cAMP. In turn cAMP is controlled by PDE. PDE4 is known to be disturbed in the brains of some people with autism.

It appears that you can activate PKA with a PDE4 inhibitor. The long established Japanese asthma drug Ibudilast is such a PDE4 inhibitor. At least one reader of this blog uses Ibudilast long term.

PDE4 inhibitor, roflumilast protects cardiomyocytes against NO-induced apoptosis via activation of PKA and Epac dual pathways

PDE4 inhibitors have been explored to treat various neurological conditions like schizophrenia.

PDE4 as a target for cognition enhancement

So logically if you feed a PDE4 inhibitor to a Pitt Hopkins mouse, you might expect something good to happen. There now is such a mouse model.

I think I could keep that mouse quite busy. 

The point being you do not have to figure things out 100%, before starting to see what you have in your drug library might be truly beneficial.  

Some of the things in the drug library are actually in the kitchen cupboard, as we have already seen. 

Protein Kinase A

Protein kinase A (PKA) is something that is both complicated and important.

The effects of PKA activation vary with cell type.

PKA has always been considered important in formation of a memory.  Formation of a normal memory is highly sensitive to PKA levels; too much is bad and too little is bad.

ARID1B in Autism and Corpus Callosum Abnormalities

I don’t think anyone has set up a research foundation for agenesis of the Corpus Callosum (ACC), perhaps they should. 

There was a post on this a while back, prompted by meeting someone whose son has this condition. 

Agenesis of the Corpus Callosum

The Corpus Callosum is just a fancy name for what joins the two sides of the brain together. Agenesis of the Corpus Callosum (ACC) is what they call it when there is a complete or partial absence of the corpus callosum.

ACC is we are told a very rare condition, but clearly smaller corpus callosum variations are a key part of some autism. 

For example, in Pitt Hopkins a small corpus callosum is typical.

An estimated 7 percent of children with autism and macrocephaly (big heads) carry a PTEN mutation. This is associated with an enlarged corpus callosum. 

PTEN is an autism gene, but it is more usually thought of as a tumor suppressor, making it a cancer gene. In older people, losing PTEN appears to be often a first step to developing cancer; up to 70% of men with prostate cancer are estimated to have lost a copy of the PTEN gene at the time of diagnosis  (https://www.ncbi.nlm.nih.gov/pubmed/16079851). 

PTEN is interesting because too little can allow cancer to develop, but too much may eventually result in type 2 diabetes. So, as always, it is a balance. 

PTEN upregulation may explain the development of insulin resistance and type 2 diabetes with high dose statins. 

Evidently from the comments in this blog, regarding tumors/cancers, people with autism are likely shifted towards the direction of lacking tumor suppressing proteins. The exception would be those born very small, or with small heads. 

ARID1B gene

ARID1B is another tumor suppressing gene, like PTEN, and like PTEN it is also an autism gene.

What I found interesting was the link between ARID1B and corpus callosum anomalies. 

ARID1B mutations are the major genetic cause of corpus callosum anomalies in patients with intellectual disability  

Corpus callosum abnormalities, intellectual disability, speech impairment, and autism inpatients with haploinsufficiency of ARID1B

Corpus callosum abnormalities are common brain malformations with a wide clinical spectrum ranging from severe intellectual disability to normal cognitive function. The etiology is expected to be genetic in as much as 30–50% of the cases, but the underlying genetic cause remains unknown in the majority of cases.

Additional functional studies including a systematic search for ARID1B target genes may show how haploinsufficiency of ARID1B predispose to CC defects and to an array of cognitive defects, including severe speech defects

Several readers of this blog have highlighted a recent study:-  

Breakthrough research suggests potential treatment for autism, intellectual disability 

We showed that cognitive and social deficits induced by an Arid1b mutation in mice are reversed by pharmacological treatment with a GABA receptor modulating drug. And, now we have a designer mouse that can be used for future studies." 

The full study:-

Arid1b haploinsufficiency disrupts cortical interneuron development and mouse behavior

Clonazepam also reversed the reduced time spent in the center and reduced moving distance displayed by Arid1b-mutant mice in the open field test (Fig. 7c,d and Supplementary Fig. 14c). However, depression measures, using the forced swim test and the tail suspension test, showed no reversible effect of clonazepam in Arid1b+/− mice compared with controls (Fig. 7e,f). Our results show that clonazepam rescues impaired recognition, social memory, and elevated anxiety in Arid1b+/− mice. 

Our mouse model effectively mirrors the behavioral characteristics of intellectual disability and ASD. Arid1b+/− and Arid1bconditional-knockout mice displayed impaired spatial learning, recognition memory, and reference memory. Open field and social behavior tests also revealed decreased social interaction in the mice. Mice with mutations in genes encoding Smarca2 and Actl6b, other subunits of the BAF complex, have severe defects in social interaction and long-term memory35. Thus, this chromatin remodeling complex may provide a cellular and molecular platform for normal intellectual and social behavior. In addition, Arid1b+/− mice showed heightened levels of anxiety- and depression-related behaviors, which are common symptoms of ASD36. 

For people with intellectual disability, the prevalence of anxiety disorders has likewise been shown to be much higher. This may be due to reduced cognitive function and increased vulnerability to environmental demands. Communication difficulties may also make it more difficult for people with cognitive disabilities to deal with anxiety or fear. ARID1B haploinsufficiency may be responsible for multiple facets of characteristic ASD behaviors. Other isoforms of Arid1b that are not affected by the Arid1b mutation could exist in the mouse line. Additionally, it is possible that the genetic background for the mouse line may impact the effect of Arid1b haploinsufficiency. Thus it is important to consider allele specificity, genetic backgrounds, and knockout strategies for comparing phenotypes of other Arid1bhaploinsufficiency models.  

GABA allosteric modulators, including clonazepam, a benzodiazepine, have been used to treat seizures and anxiety. We found that clonazepam injection rescued deficits in object and social recognition and anxiety in Arid1b+/− mice. These results suggest that treatment with a benzodiazepine could be a potential pharmacological intervention for symptoms of ASD. Furthermore, our results suggest that pharmacological manipulation of GABA signaling is a potential treatment strategy for cognitive and social dysfunctions in ASD- or intellectual disability-associated disorders due to mutations in chromatin remodeling genes.  

ACC Research Foundation

If there actually was an ACC Research Foundation, they could explore whether clonazepam was therapeutic in children who have Arid1b haploinsufficiency.

While they are at it, they might want to look into Hereditary Motor and Sensory Neuropathy with agenesis of the corpus callosum (HMSN/ACC), this is caused by mutations in the potassium-chloride co-transporter 3 (SLC12A6/KCC3) gene. This I stumbled upon a long time ago, when trying to upregulate KCC2, which causes elevated intracellular chloride in many people with autism and likely many with Down Syndrome.

KCC2 is usually associated with neuropathic pain and now we see that so is KCC3. Odd reaction to pain is a well known feature of autism. The rather ill-defined condition of fibromyalgia seems common in female relatives of those with autism and I do not think this is just a coincidence. 

The interesting thing is that the research shows you can potentially upregulate KCC3 with curcumin. 

Transit Defect of Potassium-Chloride Co-transporter 3 Is a Major Pathogenic Mechanism in Hereditary Motor and Sensory Neuropathy with Agenesis of the Corpus Callosum

HMSN/ACC is a severe and progressive neurodegenerative disease that exhibits an early onset of symptoms. Signs of HMSN/ACC, such as hypotonia and delays in motor development skills, are noticed before 1 year of age. However, the motor abilities of patients progress slowly to 4–6 years of age, and these children are able to stand and walk with some help. This is followed by a motor deterioration that generally renders affected subjects wheelchair-dependent by adolescence. 

Accordingly, we found that curcumin relieved the ER retention of dimerized R207C in mammalian cultured cells. A diet enriched in curcumin may therefore be beneficial for the relief or delay of some of the HMSN/ACC symptoms in patients bearing the R207C mutation, including the Turkish patient described in this study (as patient has not yet reached puberty).

KCC3 defects also cause the very similar Andermann syndrome also known as agenesis of corpus callosum with neuronopathy (ACCPN).

KCC3 defects are associated with epilepsy.

My question was can you have KCC3 under-expression with partial ACC, epilepsy but no peripheral neuropathy? If this was likely, then upregulating KCC3 with curcumin might help.

The gene for KCC3 is located at chromosome 15q14. Based on my “logic of associations”, if you have ACC and epilepsy you should consider KCC3 under-expression.

I did suggest to my former classmate whose son has partial ACC and epilepsy, but no neuropathy, that it might be worth trying some curcumin. Since his son is already on anti-epileptic drugs (AEDs) my suggested effect to look for was improved cognitive function.

6 months later it does indeed, apparently, improve cognitive function.  Of course this does not establish that upregulating KCC3 had anything to do with it. It is nonetheless a nice story and another parent has realized that you can change things for the better, in spite of what neurology currently says. 

The question now is can you have both ARID1B under-expression and KCC3 under-expression, in which case you would add some clonazepam, based on the latest research. At this point you should of course go and talk to your neurologist, rather than read my blog and that was my recommendation. 

Partial agenesis of the corpus callosum in a patient with juvenile myoclonic epilepsy

We describe a patient who presented at our epilepsy-monitoring unit with myoclonic jerks, and was diagnosed with juvenile myoclonic epilepsy (JME). Imaging of his brain revealed partial agenesis of the corpus callosum (ACC). We discuss the known genetic basis of both JME and ACC, as well as the role of the corpus callosum (CC) in primary generalized epilepsy. Both JME and ACC are associated with gene loci on chromosome 15q14. Structural brain abnormalities other than ACC, such as atrophy of the corpus callosum have been reported in patients with JME. ACC has been associated with seizures, suggesting an anti-epileptogenic role of the corpus callosum

Conclusion

If you have a biological diagnosis you are one big step closer to finding a therapy. Even if you have a diagnosis like partial Agenesis of the Corpus Callosum (ACC), you can go one step further and ask why. You have a 50% chance of being able to find out a specific gene that is the cause. If you know with certainty which gene is the originator of the problem, you know a lot.  I think you are then two big steps closer to a therapy.

In the case of Rett Syndrome, a really good website is run by their research foundation (Rett Syndrome Research Trust). They look like they mean business. 

https://reverserett.org/cure/

If you look at the above site you might be left wondering why the much larger and better financed autism organizations look so amateur by comparison.  The big difference is that Rett Syndrome is a biological diagnosis and autism is not. In many ways calling autism a spectrum is not helpful, as the originators of the ASD concept are beginning to realize.  The precise biological dysfunctions are what matter and lumping together hundreds of miscellaneous brain dysfunctions into a pile labelled ASD may not be so clever, in fact I would call it primitive.

Targeting Dendritic Spines to Improve Cognitive Function and Behavior in Autism; plus Hair Loss/Graying

I have written several posts about dendritic spines and their varying shapes (morphology).  This sounds like a rather obscure subject, but it looks like it may be a key area where both behavior and cognition can be modified, even later in life.

Homer Simson after using a Wnt Activator 

Dendritic spines

In a typical neuron (brain cell) you have dendrites at one end and so-called axon terminals at the other. When neurons connect with each other, an axon terminal connects with a dendritic spine from another close by neuron.  Axons transmit electrochemical signals from one neuron to the dendrites of other neurons.  The junction formed between a dendritic spine and an axon terminal is called a synapse.

One neuron can have as many as 15,000 spines, some of which are picking up signals from axon terminals of other neurons.

The number and shape of these spines is constantly changing and not surprisingly defects in this process affect both cognition and behavior.

The other end of the neuron, with the axon terminals is much less studied.  The myelin sheath deserves a mention. This protective coating is constantly being repaired in a process called remyelination. MS (Multiple Sclerosis) is caused by damage to the myelin coating that does not self repair. A newly identified feature of autism is an abnormally thin layer of myelin. A lack of insulation along the axon will affect the flow of electrical signals.

Many factors are involved in dendritic spine morphology and plasticity. Many of the same factors are known to be disturbed in autism and other related dysfunctions (schizophrenia, bipolar, ADHD etc).

Recall that within autism there are two broad groups; the larger group has “too many” dendritic spines and the smaller group has “too few”. I am writing about the larger group. My post is a simplification of a complex subject.

Factors that influence dendritic spine morphology and plasticity include:- 

·        BDNF  (want less)

·        Estrogen  (want more)

·        Reelin (want more)

·        BCL2 (want more)

·        PAK1 (want less)

·        GSK3 beta (want more)

·        PTEN (want more)

All the above seem to work via

·        Wnt signaling (want less) 

BDNF is a growth factor within the brain, which tends to be elevated in most autism.

The female hormone estrogen seems to be reduced in male autism and this will have many effects via something called ROR alpha. There is also reduced expression of estrogen receptor beta.

Reelin is a protein that is critical in brain development and maintenance. Reelin is implicated in most brain diseases, including autism. It stimulates dendritic spine development. Reelin is found to be reduced in autism.

BCl2 is a very well-known cancer gene/protein. BCL2 is part of a broader family of genes/proteins that control cell growth/death. BCL2 is anti-apoptotic, meaning it encourages growth rather than cell death. You will find elevated BCL2 in cancers.  BCL2 is implicated in both schizophrenia and autism.

Bax is another key member of the BCL2 family. The BCL2 protein duels with Bax, its counteracting twin. When Bax is in excess, cells execute a death command. When BCL2 dominates, the program is inhibited and cells survive. In cancer you want more Bax.

Modulating BCL2/Bax has been proposed as an autism therapy in Japan.

BCL2 is found to be reduced in autism.

The Japanese proposed the use of Navitoclax, a drug responsible for inhibiting BCL2 production for the treatment of cancer. I think they want to activate BCL2 production. 

I covered PAK1 in some lengthy posts. This was what the Japanese Nobel Laureate at MIT was working on. In summary, a PAK1 inhibitor should be helpful in autism, schizophrenia and some cancer.  Some people with a condition called neurofibromatosis, where non-cancerous tumors grow, use a special kind of bee propolis that contains a substance called CAPE (caffeic acid phenethyl ester), that is a mild PAK1 inhibitor.

Pak1 regulates dendritic branching and spine formation

GSK3 beta plays a role in several key signaling pathways. Abnormal expression of GSK3 beta is associated with Bipolar disorder. One role played by GSK3 beta is in Wnt signaling, which then affects dendritic spines. A GSK3 beta inhibitor, like lithium, is a Wnt activator which will increase the number of dendritic spines.

PTEN is a tumor suppressor gene/protein that is also an autism gene.

PTEN deficiency results in abnormal arborization and myelination in humans. PTEN-deficient neurons in brains of animal models have increased synaptic spine density.

People with autism and PTEN mutations have large heads because they lacked enough PTEN to reign in cell growth (and head growth).  You would expect them to have increased synaptic spine density.

Note than in both autism/cancer genes (BCL2 and PTEN) the balance is shifted towards growth, which fits in with the broad concept of autism as a growth dysfunction.

Wnt signaling is a complex and only partially understood subject, that has been previously discussed in this blog.  The short version is that most people with autism and particularly the ones with large heads will likely have too much Wnt signaling as the result of their various metabolic “disturbances”. The best way to inhibit their Wnt signaling might be to counter their particular metabolic disturbances, so if you are one of the 2% of autism with a PTEN mutation, then increase your PTEN levels.  If this is not possible than any other way to inhibit Wnt might be effective.

In Bipolar, where GSK3 beta is a known risk gene, you want more dendritic spines and so you want a GSK3 beta inhibitor like lithium. 

I think lithium will have a negative effect on most autism. Within children diagnosed with autism, a minority may well better fit a diagnosis of bipolar.

Preliminary investigation of lithium for mood disorder symptoms in children and adolescents with autism spectrum disorder.

OBJECTIVE:

Children with autism spectrum disorder (ASD) have higher rates of comorbid psychiatric disorders, including mood disorders, than the general child population. Although children with ASD may experience irritability (aggression, self-injury, and tantrums), a portion also experience symptoms that are typical of a mood disorder, such as euphoria/elevated mood, mania, hypersexuality, paranoia, or decreased need for sleep. Despite lithium's established efficacy in controlling mood disorder symptoms in the neurotypical population, lithium has been rarely studied in children with ASD.

METHODS:

We performed a retrospective chart review of 30 children and adolescents diagnosed with ASD by the Diagnostic and Statistical Manual of Mental Disorders, 4th ed., Text Revision (DSM-IV-TR) criteria who were prescribed lithium in order to assess target symptoms, safety, and tolerability. Clinical Global Impressions - Improvement (CGI-I) ratings were performed by two board-certified child psychiatrists with expertise in ASD. CGI-I scores were dichotomized into "improved" (CGI-I score of 1 or 2) or "not improved" (CGI-I score ≥3).

RESULTS:

Forty-three percent of patients who received lithium were rated as "improved" on the CGI-I. Seventy-one percent of patients who had two or more pretreatment mood disorder symptoms were rated as "improved." The presence of mania (p=0.033) or euphoria/elevated mood (p=0.041) were the pretreatment symptoms significantly associated with an "improved" rating. The mean lithium blood level was 0.70 mEq/L (SD=0.26), and the average length of lithium treatment was 29.7 days (SD=23.9). Forty-seven percent of patients were reported to have at least one side effect, most commonly vomiting (13%), tremor (10%), fatigue (10%), irritability (7%), and enuresis (7%).

CONCLUSIONS:

This preliminary assessment of lithium in children and adolescents with ASD suggests that lithium may be a medication of interest for those who exhibit two or more mood disorder symptoms, particularly mania or euphoria/elevated mood. A relatively high side effect rate merits caution, and these results are limited by the retrospective, uncontrolled study design. Future study of lithium in a prospective trial with treatment-sensitive outcome measures may be indicated.

Hair Growth and Graying 

One surprising observation is the apparent connection between dendritic spine modification and modifying growth/color of human hair.

The same pathway is involved in signaling growth and coloring in the hair on your head and growing the dendritic spines on the neurons inside your head. I have mentioned this once before in a previous post. It is relevant because if a substance is potent enough to affect your dendritic spines you would expect it also to have a visible effect on the hair, of at least some people.

For example one reader of this blog uses a PAK1 inhibitor to treat her case of autism and she found that it has a hair graying effect.

EdnrB Governs Regenerative Response of Melanocyte Stem Cells by Crosstalk with Wnt Signaling

Pigmented hair regeneration requires epithelial stem cells (EpSCs) and melanocyte stem cells (McSCs) in the hair follicle.

Thus far, only a handful of signals that regulate McSCs have been identified, including extrinsic signals, such as transforming growth factor beta (TGFB) and Wnts, which are provided by the epithelial niche. Wnt signaling induces activation of EpSCs to drive epithelial regeneration while coordinately inducing McSCs to proliferate and differentiate to pigment regenerating hair follicle

One known but uncommon side effect of my current favourite Wnt inhibitor, Mebendazole, is hair loss. Hair follicles require Wnt signaling and if there is too little Wnt signaling you will lose some hair.

BCL2 is a very important cancer gene/protein but it also plays a role in autism and in dendritic spine morphology.  Low levels of the protein BCl2 leads to premature graying.

Grey hair 'clue' to skin cancer

The team then looked at what would happen if they 'knocked out' a gene in mice that is known to be important for cell survival.

Mice lacking this Bcl2 gene went grey shortly after birth.

The scientists believe the same principle might apply in humans, which would explain why some people - such as TV presenter Philip Schofield - go grey in their 20s, while others keep their dark locks into retirement.

  

BCL2 is known to be reduced in the reduced in the brains of people with autism, as is another substance called Reelin.  Both Reelin and Bcl-2 are needed for dendritic spines to develop correctly.  

Dysregulation of Reelin and Bcl-2 proteins in autistic cerebellum.

Autism is a severe neurodevelopmental disorder with potential genetic and environmental causes. Cerebellar pathology including Purkinje cell atrophy has been demonstrated previously. We hypothesized that cell migration and apoptotic mechanisms may account for observed Purkinje cell abnormalities. Reelin is an important secretory glycoprotein responsible for normal layering of the brain. Bcl-2 is a regulatory protein responsible for control of programmed cell death in the brain. Autistic and normal control cerebellar corteces matched for age, sex, and post-mortem interval (PMI) were prepared for SDS-gel electrophoresis and Western blotting using specific anti-Reelin and anti-Bcl-2 antibodies. Quantification of Reelin bands showed 43%, 44%, and 44% reductions in autistic cerebellum (mean optical density +/- SD per 30 microg protein 4.05 +/- 4.0, 1.98 +/- 2.0, 13.88 +/- 11.9 for 410 kDa, 330 kDa, and 180 kDa bands, respectively; N = 5) compared with controls (mean optical density +/- SD per 30 microg protein, 7.1 +/- 1.6, 3.5 +/- 1.0, 24.7 +/- 5.0; N = 8, p < 0.0402 for 180 kDa band). Quantification of Bcl-2 levels showed a 34% to 51% reduction in autistic cerebellum (M +/- SD per 75 microg protein 0.29 +/- 0.08; N = 5) compared with controls (M +/- SD per 75 microg protein 0.59 +/- 0.31; N = 8, p < 0.0451). Measurement of beta-actin (M +/- SD for controls 7.3 +/- 2.9; for autistics 6.77 +/- 0.66) in the same homogenates did not differ significantly between groups. These results demonstrate for the first time that dysregulation of Reelin and Bcl-2 may be responsible for some of the brain structural and behavioral abnormalities observed in autism.  

The Reelin Signaling Pathway Promotes Dendritic Spine Development in Hippocampal Neurons 

Abstract

The development of distinct cellular layers and precise synaptic circuits is essential for the formation of well-functioning cortical structures in the mammalian brain. The extracellular protein Reelin through the activation of a core signaling pathway including the ApoER2 and VLDLR receptors and the adapter protein Dab1, controls the positioning of radially migrating principal neurons, promotes the extension of dendritic processes in immature forebrain neurons, and affects synaptic transmission. Here we report for the first time that the Reelin signaling pathway promotes the development of postsynaptic structures such as dendritic spines in hippocampal pyramidal neurons. Our data underscore the importance of Reelin as a factor that promotes the maturation of target neuronal populations and the development of excitatory circuits in the postnatal hippocampus. These findings may have implications for understanding the origin of cognitive disorders associated with Reelin deficiency.

While not everything relating to dendritic spines is variable, and hence potentially can be modified, much seems to be.

Rather like in this blog it took a few years to get a comprehensive view of the factors involved in neuronal chloride and extend the list of potential therapies, getting to the bottom of fine tuning dendritic spin morphology for improved behavior and cognition will be a complex task.

Much is already known.

Our reader AJ is busy looking at GSK3 beta inhibitors.

GSK3 beta is best known as a bipolar gene/protein, but it is becoming seen as an autism gene.

GSK3: a multifaceted kinase in Wnt signaling 

GSK3 is one of the few signaling mediators that play central roles in a diverse range of signaling pathways, including those activated by Wnts, hedgehog, growth factors, cytokines, and G protein-coupled ligands. Although the inhibition of GSK3-mediated β-catenin phosphorylation is known to be the key event in Wnt-β-catenin signaling, the mechanisms which underlie this event remain incompletely understood. The recent demonstration of GSK3 involvement in Wnt receptor phosphorylation illustrates the multifaceted roles that GSK3 plays in Wnt-β-catenin signaling. In this review, we will summarize these recent results and offer explanations, hypotheses, and models to reconcile some of these observations.

Recent advances indicate that GSK3 also plays a positive role in Wnt signal transduction by phosphorylating the Wnt receptors low density lipoprotein receptor-related protein (LRP5/6) and provide new mechanisms for the suppression of GSK3 activity by Wnt in β-catenin stabilization. Furthermore, GSK3 mediates crosstalk between signaling pathways and β-catenin-independent downstream signaling from Wnt.

GSK-3β Overexpression Alters the Dendritic Spines of Developmentally Generated Granule Neurons in the Mouse Hippocampal Dentate Gyrus

it is known that glycogen synthase kinase 3β (GSK-3β) regulates both synaptic plasticity and memory. 

GSK-3β overexpression led to a general reduction in the number of dendritic spines. In addition, it caused a slight reduction in the percentage, head diameter and length of thin spines, whereas the head diameter of mushroom spines was increased.

New clues to how lithium soothes the bipolar brain may shed light on other mental illnesses 

Over the past 2 decades, neuroscientists have built a body of evidence that links not only bipolar disease, but other psychiatric disorders including autism and schizophrenia to abnormal brain development. In particular, they have found abnormalities in the numbers of synapses and in the shape of neurons at the points where they form synapses. Their studies have often implicated abnormal signaling in a brain pathway called Wnt, which is involved both in early brain development and later, more complex, refining of brain connections. The role of Wnt could help explain why lithium is effective: It blocks an enzyme called GSK-3 β, which is an inhibitor on the Wnt pathway. By boosting Wnt signaling, lithium could produce a therapeutic effect in psychiatric diseases in which the Wnt pathway is underpowered.

They then treated the mutant mice with lithium. Although the researchers acknowledge that rodents are an imperfect proxy for human mood disorders, they did observe that the animals’ symptoms markedly improved; studies of their brains also revealed normal numbers of spines. “That’s the key finding,” Cheyette says. “It suggests that lithium could have its well-known therapeutic effect on patients with bipolar disorder by changing the stability of spines in the brain.”

GSK3 has numerous effects.

Activator or inhibitor? GSK-3 as a new drug target

Glycogen synthase kinase-3 (GSK-3) is a cytoplasmic serine/threonine protein kinase that phosphorylates and inhibits glycogen synthase, thereby inhibiting glycogen synthesis from glucose. However, this serine/threonine kinase is now known to regulate numerous cellular processes through a number of signaling pathways important for cell proliferation, stem cell renewal, apoptosis and development. Because of these diverse roles, malfunction of this kinase is also known to be involved in the pathogenesis of human diseases, such as nervous system disorders, diabetes, bone formation, inflammation, cancer and heart failure. Therefore, GSK-3 is recognized as an attractive target for the development of new drugs. The present review summarizes the roles of GSK-3 in the insulin, Wnt/β-catenin and hedgehog signaling pathways including the regulation of their activities. The roles of GSK-3 in the development of human diseases within the context of its participation in various signaling pathways are also summarized. Finally, the possibility of new drug development targeting this kinase is discussed with recent information about inhibitors and activators of GSK-3.  

Estradiol

Morphological plasticity of dendritic spines in central neurons is mediated by activation of cAMP response element binding protein 

The present study demonstrates that estradiol may trigger formation of new dendritic spines by activation of a cAMPregulated CREB phosphorylation. Induction of the CREB response requires activation of NMDA receptors, increased intracellularcalciumconcentrationsandcAMP-activatedPKA.These systems together then contribute to the CREB response, which in turn leads to the morphological changes seen with estradiol—i.e., spine formation. The biochemical and cellular routes leading from activated CREB to the morphological change in dendritic spine density are still uncharted.

Dendritic spines of the medial amygdala: plasticity, density, shape, and subcellular modulation by sex steroids.

The medial nucleus of the amygdala (MeA) is a complex component of the "extended amygdala" in rats. Its posterodorsal subnucleus (MePD) has a remarkable expression of gonadal hormone receptors, is sexually dimorphic or affected by sex steroids, and modulates various social behaviors. Dendritic spines show remarkable changes relevant for synaptic strength and plasticity. Adult males have more spines than females, the density of dendritic spines changes in the course of hours to a few days and is lower in proestrous and estrous phases of the ovarian cycle, or is affected by both sex steroid withdrawal and hormonal replacement therapy in the MePD. Males also have more thin spines than mushroom-like or stubby/wide ones. The presence of dendritic fillopodia and axonal protrusions in the MePD neuropil of adult animals reinforces the evidence for local plasticity. Estrogen affects synaptic and cellular growth and neuroprotection in the MeA by regulating the activity of the cyclic AMP response element-binding protein (CREB)-related gene products, brain-derived neurotrophic factor (BDNF), the anti-apoptotic protein B-cell lymphoma-2 (Bcl-2) and the activity-regulated cytoskeleton-related protein (Arc). These effects on signal transduction cascades can also lead to local protein synthesis and/or rearrangement of the cytoskeleton and subsequent numerical/morphological alterations in dendritic spines. Various working hypotheses are raised from these experimental data and reveal the MePD as a relevant region to study the effects of sex steroids in the rat brain.

PTEN 

Pten Regulates Neuronal Arborization and Social Interaction in Mice

CNS deletion of Pten in the mouse has revealed its roles in controlling cell size and number, thus providing compelling etiology for macrocephaly and Lhermitte-Duclos disease. PTEN mutations in individuals with autism spectrum disorders (ASD) have also been reported, although a causal link between PTEN and ASD remains unclear. In the present study, we deleted Pten in limited differentiated neuronal populations in the cerebral cortex and hippocampus of mice. Resulting mutant mice showed abnormal social interaction and exaggerated responses to sensory stimuli. We observed macrocephaly and neuronal hypertrophy, including hypertrophic and ectopic dendrites and axonal tracts with increased synapses. This abnormal morphology was associated with activation of the Akt/mTor/S6k pathway and inactivation of Gsk3β. Thus, our data suggest that abnormal activation of the PI3K/AKT pathway in specific neuronal populations can underlie macrocephaly and behavioral abnormalities reminiscent of certain features of human ASD.  

PTEN knockdown alters dendritic spine/protrusion morphology, not density

Mutations in phosphatase and tensin homolog deleted on chromosome ten (PTEN) are implicated in neuropsychiatric disorders including autism. Previous studies report that PTEN knockdown in neurons in vivo leads to increased spine density and synaptic activity. To better characterize synaptic changes in neurons lacking PTEN, we examined the effects of shRNA knockdown of PTEN in basolateral amygdala neurons on synaptic spine density and morphology using fluorescent dye confocal imaging. Contrary to previous studies in dentate gyrus, we find that knockdown of PTEN in basolateral amygdala leads to a significant decrease in total spine density in distal dendrites. Curiously, this decreased spine density is associated with increased miniature excitatory post-synaptic current frequency and amplitude, suggesting an increase in number and function of mature spines. These seemingly contradictory findings were reconciled by spine morphology analysis demonstrating increased mushroom spine density and size with correspondingly decreased thin protrusion density at more distal segments. The same analysis of PTEN conditional deletion in dentate gyrus demonstrated that loss of PTEN does not significantly alter total density of dendritic protrusions in the dentate gyrus, but does decrease thin protrusion density and increases density of more mature mushroom spines. These findings suggest that, contrary to previous reports, PTEN knockdown may not induce de novo spinogenesis, but instead may increase synaptic activity by inducing morphological and functional maturation of spines. Furthermore, behavioral analysis of basolateral amygdala PTEN knockdown suggests that these changes limited only to the basolateral amygdala complex may not be sufficient to induce increased anxiety-related behaviors. 

WNT/β-catenin signaling regulates mitochondrial activity to alter the oncogenic potential of melanoma in a PTEN-dependent manner

Aberrant regulation of WNT/β-catenin signaling has a crucial role in the onset and progression of cancers, where the effects are not always predictable depending on tumor context. In melanoma, for example, models of the disease predict differing effects of the WNT/β-catenin pathway on metastatic progression. Understanding the processes that underpin the highly context-dependent nature of WNT/β-catenin signaling in tumors is essential to achieve maximal therapeutic benefit from WNT inhibitory compounds. In this study, we have found that expression of the tumor suppressor, phosphatase and tensin homolog deleted on chromosome 10 (PTEN), alters the invasive potential of melanoma cells in response to WNT/β-catenin signaling, correlating with differing metabolic profiles. This alters the bioenergetic potential and mitochondrial activity of melanoma cells, triggered through regulation of pro-survival autophagy. Thus, WNT/β-catenin signaling is a regulator of catabolic processes in cancer cells, which varies depending on the metabolic requirements of tumors.

BDNF

Brain-Derived Neurotrophic FactorLevels in Autism: A Systematic Review and Meta-Analysis. 

A meta-analysis of blood BDNF in 887 patients with ASD and 901 control subjects demonstrated significantly higher BDNF levels in ASD compared to controls with the SMD of 0.47 (95% CI 0.07-0.86, p = 0.02). In addition subgroup meta-analyses were performed based on the BDNF specimen. The present meta-analysis study led to conclusion that BDNF might play role in autism initiation/ propagation and therefore it can be considered as a possible biomarker of ASD.

Neurotrophin and Wnt signaling cooperatively regulate dendritic spine formation 

Dendritic spines are major sites of excitatory synaptic transmission and changes in their numbers and morphology have been associated with neurodevelopmental and neurodegenerative disorders. Brain-derived Neurotrophic Factor (BDNF) is a secreted growth factor that influences hippocampal, striatal and neocortical pyramidal neuron dendritic spine density. However, the mechanisms by which BDNF regulates dendritic spines and how BDNF interacts with other regulators of spines remain unclear. We propose that one mechanism by which BDNF promotes dendritic spine formation is through an interaction with Wnt signaling. Here, we show that Wnt signaling inhibition in cultured cortical neurons disrupts dendritic spine development, reduces dendritic arbor size and complexity, and blocks BDNF-induced dendritic spine formation and maturation. Additionally, we show that BDNF regulates expression of Wnt2, and that Wnt2 is sufficient to promote cortical dendrite growth and dendritic spine formation. Together, these data suggest that BDNF and Wnt signaling cooperatively regulate dendritic spine formation.

Other Wnt inhibitors

Yet another anti-parasite drug, Niclosamide,  turns out to be a Wnt inhibitor. 

The Anti-Helminthic Niclosamide Inhibits Wnt/Frizzled1 Signaling

Not surprisingly, Niclosamide is now a candidate drug to treat several different types of cancer.  It is also thought to have great potential in suppressing the metastatic process of prostate cancer. Another extremely cheap drug, not available in the US.

Even the flavonoid quercetin can inhibit Wnt. 

Quercetin, a potent inhibitor against beta-catenin/Tcf signaling in SW480 colon cancer cells.

Therapeutic Avenues

There certainly are many potential ways to fine tune dendritic spine morphology.

Some readers of this blog are already doing just that, perhaps not all realizing it. 

·        BDNF  (want less - TrkB inhibitor)

·        Estrogen 

·        Reelin (want more – statin via RAS activation)

·        BCL2 (want more – statin)

·        PAK1 (want less – PAK inhibitor, BIO30)

·        GSK3 beta (want more – GSK3 activator)

·        PTEN (want more – statin)

All the above seem to work via

·        Wnt signaling (want less – Mebendazole/Niclosamide etc)

If you inhibit GSK3 beta you activate Wnt. You need get things the right way around. 

Statins promote RAS signaling which appears to increase Reelin expression. 

RAS signaling through PI3-Kinase controls cell migration via modulation of Reelin expression

Conclusion

Fine tuning dendritic spine morphology seems like a good target for those with MR/ID and also those with any kind of neurological disorder.

There appear to be many ways to achieve this.

It seems a plausible idea and in many ways seems more credible than the idea of a diuretic (bumetanide) raising some people’s IQ.

The big issue is which substances have sufficient potency, once they have crossed the blood brain barrier, to do anything at all.  This is an issue with all therapies targeting the brain, including bumetanide.

At least substances that can affect hair growth and color are making it through to the bloodstream, which is a start.

Does this mean that tuning your dendritic spines will inevitably make your hair turn grey or begin to thin?  I don’t think so. I think this will happen in people who have low to normal Wnt signaling to start with.

Do some people with naturally premature graying, or thinning, hair have low levels of Wnt signaling? Quite possibly. Are they more likely to have traits of bipolar/creativity? Look for actors with gray or thinning hair.

Do people with autism tend to have full heads of thicker hair, as well as bigger heads?

Do the minority of people with autism and small heads have thinning hair?

Some readers of this blog are already using statins to treat autism. As has been pointed out in earlier posts, other than lowing cholesterol, statins have potent anti-inflammatory effects and they also affect expression of RAS, PTEN and BCL2, all of which are implicated in autism and all affect dendritic spines. It seems plausible that these readers are already modifying dendritic spine morphology.