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Showing posts with label PKA. Show all posts
Showing posts with label PKA. Show all posts

Wednesday 19 September 2018

Ketones and Autism Part 5 - BHB, Histone Acetylation Modification, BDNF Expression, PKA, PKB/Akt, Microglial Ramification, Depression and Kabuki Syndrome















Child displaying elongated eyelids typical of Kabuki syndrome
Source: Given by Parents of children pictured with purpose of representing children with kabuki on Wikipedia. 

The syndrome is named after its resemblance to Japanese Kabuki makeup.

As we have discovered in this blog, autism is just a condition where certain genes are over-expressed and other genes are under-expressed. Put like that makes it sound quite simple.

Methylation of histones can either increase or decrease transcription of genes. The subject is highly complex, but we can keep things simple.

The child in the photo above has Kabuki syndrome and is likely to exhibit features of autism.  In most cases this is the result of a lack of expression of the KMT2D/MLL2 gene which encodes a protein called Histone-lysine N-methyltransferase.  Unfortunately, this is quite an important protein, because it promotes the “opening of chromatin”.  It adds a “trimethylation mark to H3K4”, just think of it as a pink post-it on your DNA. 
We get H3K4me3, which is an epigenetic marker (me3, because it is trimethylation). H3K4me3 promotes gene activation and it can cause a relative imbalance between open and closed chromatin states for critical genes. It has been suggested that it may be possible to restore this balance with drugs that promote open chromatin states, such as histone deacetylase inhibitors (HDACi).
What all this means is that people with Kabuki start with under-expression of just one gene, but this leads to the miss-expression of numerous other genes. Because science has figured out what the KMT2D/MLL2 gene does, we can find ways of treating this syndrome.

BHB as an HDAC inhibitor and a treatment for Kabuki syndrome

HDAC inhibitors (HDACi) are also suggested as therapies for other single gene syndromes. We saw in an earlier post that in Pitt Hopkins syndrome people lack Transcription Factor 4 (TCF4). Too little TC4 is not good, but too much TC4 is one feature of schizophrenia.
We saw in the research that we can increase expression of TCF4 using a class 1 HDAC inhibitor and we can also activate the Wnt pathway, which can also be achieved by inhibiting GSK3 (all themes covered in this blog).
So, Pitt Hopkins therapies include: -
·        Wnt activation (covered extensively in this blog) this includes statins and GSK3 inhibitors like Lithium

·        HDAC inhibitors like valproic acid, some cancer drugs, sodium butyrate and indeed the ketone BHB
This also means that people with schizophrenia, and likely too much TCF4, might benefit from the opposite gene expression modification, so a Wnt inhibitor, these include some cheap, safe, drugs used to treat children with parasites (Mebendazole/ Niclosamide etc) and of course GSK3 activators.
It is interesting that after 500 posts of this amateur blog you can start to fit the science together and identify rational therapies for complex disorders and  note that these therapies have much wider application, either to milder conditions or discovering avenues to treat the opposite genetic variation.  The underlying biological themes are all reoccurring in different types of autism/schizophrenia/ bipolar and you do wonder why more has not been done by professionals to apply this knowledge. 500 posts may sound a lot, but for autism researchers this is their paid, full-time job, not just a hobby pastime.

But then again, Simon Baron-Cohen, Head of Cambridge University's Autism Research Centre, recently published an article in which he wrote:

"We at the Autism Research Centre have no desire to cure, prevent or eradicate autism ... As scientists, our agenda is simply to understand the causes of autism." 

Whose team is he playing for?

My conclusion is that perhaps Baron-Cohen has Asperger's himself, because he does not realize that a disorder, severe enough for a medical/psychiatric diagnosis, is a bad thing that should be minimized and ideally prevented, just like any other brain disorder. His cousin the actor Sacha gives a very good impression of someone with bipolar, so perhaps they both need a Wnt activator?

Would a mother with Multiple Sclerosis (MS) want her daughter to also develop MS to share the experience? I think not. If it is just "quirky autism", it does not warrant a medical diagnosis, because it is perfectly okay to be quirky. 

This blog does have many Aspie readers who do want pharmacological therapy and that is their choice; I am fully supportive of them and wish them well.

Back to Kabuki
There is more than one type of HDAC and so there are different types of HDACi.  There are actually 18 HDAC enzymes divided into four classes
The ketone BHB inhibits HDAC class I enzymes called HDAC2 and HDAC3
The good news is that the ketogenic diet, which produces BHB, does indeed show merit as a therapy for Kabuki.

Kabuki syndrome is caused by haploinsufficiency for either of two genes that promote the opening of chromatin. If an imbalance between open and closed chromatin is central to the pathogenesis of Kabuki syndrome, agents that promote chromatin opening might have therapeutic potential. We have characterized a mouse model of Kabuki syndrome with a heterozygous deletion in the gene encoding the lysine-specific methyltransferase 2D (Kmt2d), leading to impairment of methyltransferase function. In vitro reporter alleles demonstrated a reduction in histone 4 acetylation and histone 3 lysine 4 trimethylation (H3K4me3) activity in mouse embryonic fibroblasts from Kmt2d+/βGeo mice. These activities were normalized in response to AR-42, a histone deacetylase inhibitor. In vivo, deficiency of H3K4me3 in the dentate gyrus granule cell layer of Kmt2d+/βGeo mice correlated with reduced neurogenesis and hippocampal memory defects. These abnormalities improved upon postnatal treatment with AR-42. Our work suggests that a reversible deficiency in postnatal neurogenesis underlies intellectual disability in Kabuki syndrome.

Intellectual disability is a common clinical entity with few therapeutic options. Kabuki syndrome is a genetically determined cause of intellectual disability resulting from mutations in either of two components of the histone machinery, both of which play a role in chromatin opening. Previously, in a mouse model, we showed that agents that favor chromatin opening, such as the histone deacetylase inhibitors (HDACis), can rescue aspects of the phenotype. Here we demonstrate rescue of hippocampal memory defects and deficiency of adult neurogenesis in a mouse model of Kabuki syndrome by imposing a ketogenic diet, a strategy that raises the level of the ketone beta-hydroxybutyrate, an endogenous HDACi. This work suggests that dietary manipulation may be a feasible treatment for Kabuki syndrome.
 Although BHB has previously been shown to have HDACi activity (7, 21), the potential for therapeutic application remains speculative. Here, we show that therapeutically relevant levels of BHB are achieved with a KD modeled on protocols that are used and sustainable in humans (22, 23). In addition, we demonstrate a therapeutic rescue of disease markers in a genetic disorder by taking advantage of the BHB elevation that accompanies the KD.
Our findings that exogenous BHB treatment lead to similar effects on neurogenesis as the KD support the hypothesis that BHB contributes significantly to the therapeutic effect. In our previous study (6), the HDACi AR-42 led to improved performance in the probe trial of the MWM for both Kmt2d+/βGeo and Kmt2d+/+ mice (genotype-independent improvement). In contrast, KD treatment only led to improvement in Kmt2d+/βGeo mice (genotype-dependent improvement). This discrepancy may relate to the fact that AR-42 acts as an HDACi but also affects the expression of histone demethylases (24), resulting in increased potency but less specificity. Alternatively, because the levels of BHB appear to be higher in Kmt2d+/βGeo mice on the KD, the physiological levels of BHB might be unable to reach levels in Kmt2d+/+ mice high enough to make drastic changes on chromatin.
In addition to the effects seen on hippocampal function and morphology, we also uncovered a metabolic phenotype in Kmt2d+/βGeo mice, which leads to both increased BHB/AcAc and lactate/pyruvate ratios during ketosis; an increased NADH/NAD+ ratio could explain both observations. This increased NADH/NAD+ ratio may relate to a previously described propensity of Kmt2d+/βGeo mice toward biochemical processes predicted to produce NADH, including beta-oxidation, and a resistance to high-fat-diet–induced obesity (27). If this exaggerated BHB elevation holds true in patients with KS, the KD may be a particularly effective treatment strategy for this patient population; however, this remains to be demonstrated. Alterations of the NADH/NAD+ ratio could also affect chromatin structure through the action of sirtuins, a class of HDACs that are known to be NAD+ dependent (28). Advocates of individualized medicine have predicted therapeutic benefit of targeted dietary interventions, although currently there are few robust examples (2931). This work serves as a proof-of-principle that dietary manipulation may be a feasible strategy for KS and suggests a possible mechanism of action of the previously observed therapeutic benefits of the KD for intractable seizure disorder (22, 23).                   
Kabuki syndrome (KS) (Kabuki make-up syndrome, Niikawa-Kuroki syndrome) is a rare genetic disorder first diagnosed in 1981. Kabuki make-up syndrome (KMS) is a multiple malformation/intellectual disability syndrome that was first described in Japan but is now reported in many other ethnic groups. KMS is characterized by multiple congenital abnormalities: craniofacial, skeletal, and dermatoglyphic abnormalities; intellectual disability; and short stature. Other findings may include: congenital heart defects, genitourinary anomalies, cleft lip and/or palate, gastrointestinal anomalies including anal atresia, ptosis and strabismus, and widely spaced teeth and hypodontia. The KS is associated with mutations in the MLL2 gene in some cases were also observed deletions of KDM6A. This study describes three children with autism spectrum disorders (ASDs) and KS and rehabilitative intervention that must be implemented.

So what?
Unless you know someone with Kabuki syndrome, you might be wondering what does this matter to autism.
What is shows is that BHB/KD is sufficiently potent to be a viable HDAC inhibitor. 
We know that some cancer drug HDAC inhibitors are effective in some mouse models of autism. But these drugs usually have side effects. 

HDAC Inhibitors for which Cancer/Autism? 

BHB is safe endogenous substance, so it is a “natural” HDACi. 

The effect of HDAC2 and HDAC3 on BDNF 
Brain derived neurotropic factor (BDNF) is like brain fertilizer. In some types of autism, you would like more BDNF.
When you exercise you produce BHB and that goes on to trigger the release of BDNF. This process also involves NF-kB activation

Exercise induces beneficial responses in the brain, which is accompanied by an increase in BDNF, a trophic factor associated with cognitive improvement and the alleviation of depression and anxiety. However, the exact mechanisms whereby physical exercise produces an induction in brain Bdnf gene expression are not well understood. While pharmacological doses of HDAC inhibitors exert positive effects on Bdnf gene transcription, the inhibitors represent small molecules that do not occur in vivo. Here, we report that an endogenous molecule released after exercise is capable of inducing key promoters of the Mus musculus Bdnf gene. The metabolite β-hydroxybutyrate, which increases after prolonged exercise, induces the activities of Bdnf promoters, particularly promoter I, which is activity-dependent. We have discovered that the action of β-hydroxybutyrate is specifically upon HDAC2 and HDAC3, which act upon selective Bdnf promoters. Moreover, the effects upon hippocampal Bdnf expression were observed after direct ventricular application of β-hydroxybutyrate. Electrophysiological measurements indicate that β-hydroxybutyrate causes an increase in neurotransmitter release, which is dependent upon the TrkB receptor. These results reveal an endogenous mechanism to explain how physical exercise leads to the induction of BDNF.

Results: ROS was significantly increased in neurons after 6 hours of ketone incubation. However, after 24 hours, neurons show improved efficiency in ATP productions, upregulated expressions of antioxidant enzyme SOD2, and enhanced resistance to excitotoxicity. These effects were significantly abolished in neurons after treatment with TrkB inhibitor. More interestingly, ROS scavengers or blocking ROS-dependent NF-kB activation significantly decreased ketone-dependent BDNF-upregulation in neurons, suggesting that ROS may have increased BDNF expressions to improve mitochondrial respiration as adaptive responses.
Conclusions: 3OHB initially generates ROS and poses oxidative stress. However, ROS appears to trigger adaptive responses against oxidative stress by upregulating BDNF through NF-kB activation, which can improve mitochondrial oxidative capacity and ultimately enhance neuroprotection
BHB/KD promotes PKA/CREB activation 
Another clever way to change the function/expression of multiple genes in one single step is to use a protein kinase.  Up to 30% of all human proteins may be modified by kinase activity.  
A protein kinase is an enzyme that modifies other proteins by chemically adding phosphate groups to them (phosphorylation). Phosphorylation usually results in a functional change of the target protein.
In the autism research you may well have come across PKA, PKB (Akt) and PKC. They clearly are disturbed in much autism.
The research shows that BHB activates PKA.
If you want good myelination you need PKA.
This might be another reason why BHB/KD is helpful in people with Multiple Sclerosis.
In much autism the myelin coating is found to be abnormally thin. 

BHB, Microglial Ramification and Depression (yes, depression)
I am increasingly impressed by research from China. The paper below by Chao Huang et al is excellent and I think we need a Chinese on the Dean’s List of this blog, it looks like he is the first.
Nantong, China on the Yangtze River and home to Chao Huang and more than 7 million other people 
Source: Wikipedia Dolly 442

The ketone body metabolite β-hydroxybutyrate induces an antidepression-associated ramification of microglia via HDACs inhibition-triggered Akt-small RhoGTPase activation. 


Abstract


Direct induction of macrophage ramification has been shown to promote an alternative (M2) polarization, suggesting that the ramified morphology may determine the function of immune cells. The ketone body metabolite β-hydroxybutyrate (BHB) elevated in conditions including fasting and low-carbohydrate ketogenic diet (KD) can reduce neuroinflammation. However, how exactly BHB impacts microglia remains unclear. We report that BHB as well as its producing stimuli fasting and KD induced obvious ramifications of murine microglia in basal and inflammatory conditions in a reversible manner, and these ramifications were accompanied with microglial profile toward M2 polarization and phagocytosis. The protein kinase B (Akt)-small RhoGTPase axis was found to mediate the effect of BHB on microglial shape change, as (i) BHB activated the microglial small RhoGTPase (Rac1, Cdc42) and Akt; (ii) Akt and Rac1-Cdc42 inhibition abolished the pro-ramification effect of BHB; (iii) Akt inhibition prevented the activation of Rac1-Cdc42 induced by BHB treatment. Incubation of microglia with other classical histone deacetylases (HDACs) inhibitors, but not G protein-coupled receptor 109a (GPR109a) activators, also induced microglial ramification and Akt activation, suggesting that the BHB-induced ramification of microglia may be triggered by HDACs inhibition. Functionally, Akt inhibition was found to abrogate the effects of BHB on microglial polarization and phagocytosis. In neuroinflammatory models induced by lipopolysaccharide (LPS) or chronic unpredictable stress (CUS), BHB prevented the microglial process retraction and depressive-like behaviors, and these effects were abolished by Akt inhibition. Our findings for the first time showed that BHB exerts anti-inflammatory actions via promotion of microglial ramification. 



NOTE:  Ramified Microglia = Resting Microglia


The brain microglia play important roles in sensing even subtle variations of their milieu. Upon moderate activation, they control brain activity via phagocytosis of cell debris and production of pro-inflammatory mediators and reactive oxygen species. However, a persistent activation would make the microglia transfer into a status with an amoeboid morphology tightly associated with neuronal damage and pro-inflammatory cytokine overproduction.

Unlike the activated microglia, the un-stimulated microglia are in a ramified status with extensively branched processes, an contribute to brain homeostasis via regulation of synaptic remodeling and neurotransmission. The ramified microglia has been shown to be associated with the induction of M2 polarization. A study by McWhorter et al. showed that elongation of macrophage by control of cell shape directly increases the expression of M2 markers and reduces the secretion of proinflammatory cytokines, suggesting that induction of microglial ramification may be a mechanism for regulation of microglial function. Methods that trigger microglial ramification may help treat brain disorders associated with neuroinflammation.
In this study, we found that BHB induces a functional ramification of murine microglia in both basal and inflammatory conditions in vitro and in vivo. The pro-ramification effects of BHB are associated with the change in microglial polarization and phagocytosis as well as the antidepressant-like effects of BHB in LPS- or chronic unpredictable stress (CUS)-stimulated mice. The ramified morphology in microglia is also induced by two BHB-producing stimuli fasting and KD, as well as two other HDACs inhibitors valproic acid (VPA) and trichostatin A (TSA). Given that microglial overactivation can mediate the pathogenesis of depression, induction of microglial ramification by BHB may have therapeutic significance in depression. 

These data confirm that BHB has an ability to transform the activated microglia back to their ramified and resting status in inflammatory conditions.

Recall the recent post about BHB and the Niacin Receptor HCA2/GPR109A in Autism:

The Chinese paper continues:

It is HDACs inhibition but not GPR109A activation that mediates the pro-ramification effect of BHB in microglia Akt inhibition abrogates the effects of BHB on microglial ramification, polarization, and phagocytosis
Akt inhibition prevents the antidepressant-like effects of BHB in acute and chronic depression models

Note that Akt is another name for Protein Kinase B (PKB)

One of the major findings in the present study is that the ketone body metabolite BHB as well as its producing stimuli fasting and KD induced reversible ramifications of murine microglia in vitro and in vivo, and these ramifications were not altered by pro-inflammatory stimuli. The ramified morphology induced by BHB seems to be a signal upstream of microglial polarization, and may mediate the antidepressant-like effect of BHB in depression induced by neuroinflammatory stimuli. Since the regulating effect of BHB in disorders associated with neuroinflammation has been well-documented, our findings provide a novel mechanism for the explanation of the neuroprotective effect of BHB in neurodegenerative and neuropsychiatric disorders from the aspect of the feedback regulation of microglial function by microglial ramification.
Induction of microglial ramification, a strategy neglected by most scientists for a long time, may have more important therapeutic significance than that of regulation of microglial polarization alone at the molecular level.

In experiments in vivo, we showed that BHB ameliorated the depressive-like behaviors induced by two neuroinflammatory stimuli LPS and CUS. These results are in accordance with previous reports, which showed that the BHB-producing stimuli, caloric restriction and fasting, produce potential antidepressant-like activities in both animals and humans. Thus, together with the pro-ramification effect of BHB in microglia in vitro, we speculate that the microglial shape change may be an independent signal that determines microglial function.

Our further analysis showed that the BHB-induced microglial ramification was mediated by the Rac1-Cdc42 signal, as BHB markedly increased the activity of Rac1 and Cdc42, and Rac1/Cdc42 inhibition attenuated the pro-ramification effect of BHB. The PI3K-Akt signal has been shown to mediate the activation of Rac1/Cdc42, and once accepting the signal from Akt, the Rac1-Cdc42 will be mobilized to promote lamellipodia/filopodia formation and cell shape change (Huang et al., 2016a). We showed that the BHB-induced microglial ramification was mediated by the Akt signal, as Akt inhibition suppressed the induction of microglial ramification by BHB. As a functional evidence for the involvement of Akt in the pro-ramification effect of BHB, Akt inhibition was found to block the functional changes in BHB-treated microglia in vitro and in vivo, including blockage of the anti-inflammatory and prophagocytic activity of BHB and abrogation of the antidepressant-like effects of BHB. Since the ramified morphology determines the anti-inflammatory phenotype in macrophages (McWhorter et al., 2013), our data suggest that there may exist a causal relationship between the ramified morphology and microglial function after BHB treatment, and this relationship may evidence the clinical significance of our findings, as the microglial process retraction has been shown to mediate the development of neurodegenerative and neuropsychiatric disorders.

Furthermore, considering the serum level of BHB in humans begin to rise to 6 to 8 mM with prolonged fasting (Cahill, 2006), investigation of whether the pro-ramification effect of BHB exists in human individuals should be of great value for the application of BHB in disease therapy. 


 Exposure to hypobaric hypoxia causes neuron cell damage, resulting in impaired cognitive function. Effective interventions to antagonize hypobaric hypoxia-induced memory impairment are in urgent need. Ketogenic diet (KD) has been successfully used to treat drug-resistant epilepsy and improves cognitive behaviors in epilepsy patients and other pathophysiological animal models. In the present study, we aimed to explore the potential beneficial effects of a KD on memory impairment caused by hypobaric hypoxia and the underlying possible mechanisms. We showed that the KD recipe used was ketogenic and increased plasma levels of ketone bodies, especially β-hydroxybutyrate. The results of the behavior tests showed that the KD did not affect general locomotor activity but obviously promoted spatial learning. Moreover, the KD significantly improved the spatial memory impairment caused by hypobaric hypoxia (simulated altitude of 6000 m, 24 h). In addition, the improving-effect of KD was mimicked by intraperitoneal injection of BHB. The western blot and immunohistochemistry results showed that KD treatment not only increased the acetylated levels of histone H3 and histone H4 compared to that of the control group but also antagonized the decrease in the acetylated histone H3 and H4 when exposed to hypobaric hypoxia. Furthermore, KD-hypoxia treatment also promoted PKA/CREB activation and BDNF protein expression compared to the effects of hypoxia alone. These results demonstrated that KD is a promising strategy to improve spatial memory impairment caused by hypobaric hypoxia, in which increased modification of histone acetylation plays an important role

Exogenous BHB prevents spatial memory impairment induced by hypobaric hypoxia

To further verify whether ketone body, a product of KD, has direct improving effect, we chose the most stable physiologic ketone body, BHB, for the subsequent experiment. In order to mimic the effect of KD as above described, the rats were pre-treated with BHB (at a dose of 200mg/kg/day) for 2 weeks and then submitted to Morris water maze test. Since intraperitoneal injection would allow substances to be absorbed at a slower rate and intraperitoneal injection would produce marginal effect during behavioral tests [16], we used the intraperitoneal injection of BHB, which has been applied in published reports [17, 18]. Although the rats in the control and BHB groups learned to find the platform with the same pattern during 5 days of acquisition training (Fig 4B), BHB could significantly improve the memory impairment induced by hypobaric hypoxia, represented by more crossing number, more time in the target quadrant, and decreased latency to first entry to platform compared to hypobaric hypoxia treatment alone (Fig 4C–4F). These results demonstrated that BHB has a direct memory-improving effect and served as the main executor of KD beneficial effects.

KD increases histone acetylation modification in the hippocampus

A previous study found that BHB is an endogenous HDAC inhibitor, and the KD recipe in our study substantially increased plasma levels of BHB. Then, we detected the effect of KD on histone acetylation in the hippocampus, which is responsible for learning and memory. As shown in Fig 5, the acetylated histone H3 (K9/K14), acetylated histone H3 (K14), and acetylated histone H4 (K12), were all increased in the hippocampus of the KD rats. Although the histone acetylation modifications listed above are decreased in hypoxia-treated rats, KD treatment could reverse the decreased levels of histone acetylation. The same pattern was displayed in the immunohistochemical staining, in which the hypoxia-induced decrease in acetylated histone H3 and acetylated histone H4 in the CA1 region of the hippocampus was reversed by KD treatment  

KD activates PKA/CREB signaling in the hippocampus

To explore a possible underlying mechanism of the beneficial effect of KD treatment on cognition, the activity of the PKA/CREB pathway in the four groups was also evaluated by western blot (Fig 7A). KD treatment was shown to not only increase the levels of PKA substrates and p-CREB (KD vs STD) but also reverse the decline in PKA substrates, p-CREB and CREB (KD-Hy vs STD-Hy). Although KD pre-treatment produced a partial restoration of PKA activity, p-CREB is nearly completely restore to its basic levels, which is may be account for its other upstream kinases, like calmodulin-dependent kinases [19]. Interestingly, the hypoxia-induced down-regulation of BDNF, a well-known neurotrophic factor involved in learning and memory formation processes, was also up-reregulated by KD treatment. These results demonstrated that KD treatment promoted PKA/CREB activation and BDNF protein expression. In order to detect whether KD promoted BDNF expression at mRNA levels, qRT-PCR assays were performed using BDNF specific primers. We found that KD-pretreatment significantly increased mRNA levels compared with that in hypobaric hypoxia group (Fig 7B). Next, we used ChIP-PCR to test if there might be increased enrichment of acetylated histones on the promoter of BDNF gene. We focused on the promoter I of BDNF gene, which response to neuronal activity [20). ]. The results showed that there is increased binding of acetylated histone H3 to the promoter I of BDNF gene (Fig 7C   

Concentrations of acetyl–coenzyme A and nicotinamide adenine dinucleotide (NAD+) affect histone acetylation and thereby couple cellular metabolic status and transcriptional regulation. We report that the ketone body d-β-hydroxybutyrate (βOHB) is an endogenous and specific inhibitor of class I histone deacetylases (HDACs). Administration of exogenous βOHB, or fasting or calorie restriction, two conditions associated with increased βOHB abundance, all increased global histone acetylation in mouse tissues. Inhibition of HDAC by βOHB was correlated with global changes in transcription, including that of the genes encoding oxidative stress resistance factors FOXO3A and MT2. Treatment of cells with βOHB increased histone acetylation at the Foxo3a and Mt2 promoters, and both genes were activated by selective depletion of HDAC1 and HDAC2. Consistent with increased FOXO3A and MT2 activity, treatment of mice with βOHB conferred substantial protection against oxidative stress. 
Abnormalities in mitochondrial function and epigenetic regulation are thought to be instrumental in Huntington's disease (HD), a fatal genetic disorder caused by an expanded polyglutamine track in the protein huntingtin. Given the lack of effective therapies for HD, we sought to assess the neuroprotective properties of the mitochondrial energizing ketone body, D-β-hydroxybutyrate (DβHB), in the 3-nitropropionic acid (3-NP) toxic and the R6/2 genetic model of HD. In mice treated with 3-NP, a complex II inhibitor, infusion of DβHB attenuates motor deficits, striatal lesions, and microgliosis in this model of toxin induced-striatal neurodegeneration. In transgenic R6/2 mice, infusion of DβHB extends life span, attenuates motor deficits, and prevents striatal histone deacetylation. In PC12 cells with inducible expression of mutant huntingtin protein, we further demonstrate that DβHB prevents histone deacetylation via a mechanism independent of its mitochondrial effects and independent of histone deacetylase inhibition. These pre-clinical findings suggest that by simultaneously targeting the mitochondrial and the epigenetic abnormalities associated with mutant huntingtin, DβHB may be a valuable therapeutic agent for HD.  

Conclusion
At the end of this fifth post on ketones and autism, I think we have established beyond any doubt that ketones can do some amazing things for numerous dysfunctions and diseases.
The question remains how much you need to achieve the various possible benefits. 
The next question, already put to me by one parent, is how do you measure such a benefit.  Some people’s idea of treating autism is just to eradicate disturbing behaviours like SIB and ensure a placid, cooperative child when out in public.  Other people notice small cognitive and speech changes, because they spend hours a day teaching their child. Small but significant cognitive improvement may not show up on autism rating scales.
You would expect a dose dependent response, so the more ketones the bigger the response, which suggests that the full Ketogenic Diet (KD) is the ultimate option.
A lot does seem to be possible just with BHB and C8 (caprylic acid) as supplements to a regular diet.
Adults with Alzheimer’s, or Huntington’s, or Multiple Sclerosis (MS) all stand to potentially benefit from ketone supplements.
Children/adults with certain single-gene autisms, not limited to Kabuki and Pitt Hopkins potentially should benefit from ketone supplements.
Interestingly, another benefit of BHB is on mood; it seems to make some people just feel much better, apparently all due to the effect on microglia. So perhaps autism parents who take antidepressants should try BHB instead.







Thursday 1 February 2018

Myelin and Skill Acquisition, Treating MS, plus Tuning P2X7



Today’s post was prompted by a recent visit from Monty’s assistant from when he was 3 to 9 years old. She was asking about how to improve fine motor skills in one of her class. In the background Monty, now aged 14 with ASD, was playing the piano and I said just look at those fingers move, no sign of a fine motor skill disorder any more.

Source: http://docjana.com/saltatory-conduction/
Slow going without Myelin

So how do you improve both fine and gross motor skills and why are deficits so common in autism?
It does look like practice makes perfect, but there is actually some science behind this and it might help explain in part why young people with autism are very slow to acquire skills.  I should point out that there are multiple contributing factors, not least any kind of excitatory-inhibitory imbalance, but today’s post is about myelin.
Normally developing babies gradually start to develop fine and gross motor skills, become toilet trained and learn to talk.
The process by which you learn all these skills is at least partially understood. Myelin’s role particularly in acquiring motor skills has been the subject of a great deal of research in recent years.
We now know that without myelin you cannot acquire new skills.
When you acquire a new skill a network has to be created linking neurons together.
Neurons, when myelinated, look something like this:- 








The detail of inside the body of the neuron contains some of things we have looked at like Mitochondria and Endoplasmic reticulum.










Dendritic spines are those small protrusions from the dendrite which are like docking stations where one neuron connects with another. An axon terminal (far right on the first illustration) of one neuron connects with dendritic spine of a neighboring neuron.
A skill (like an app on your smart phone) is just a network of these connections between neurons. To make this network efficient and hopefully permanent, myelin is deposited along this pathway. This speeds up the rate at which the electrical signals can pass along the network. Myelin is white in colour and these myelinated pathways become the brain’s white matter. 
Here is the animation from the beginning of this post, showing that it is slow going, on the left, without myelin.





Source: http://docjana.com/saltatory-conduction/

The Synapse
Just for completeness, the synapse is the place where the axon end of one neuron connects with the dendrite end of another neuron. The synapse is where lots of clever things are happening and sometimes things go wrong. Drugs often target the synapse.

Multiple Sclerosis (MS)
Most people have heard about MS, this is a condition caused by the loss of myelin or the inability to constantly maintain the myelin layer, via remyelination.
MS mainly affects females but has some similarities with autism; there is oxidative stress and chronic inflammation. By treating oxidative stress (with ALA) it has been shown that there is a benefit in MS, just as there is in autism. 
MS may be a family of conditions, because many different things are implicated, bacteria, virus etc.
MS is usually a cyclical disorder with regressions, improvements and remissions.
The inflammatory response in MS leads to damage of the myelin protective insulation in networks in the brain that have been created for specific skills. 
There are experimental finding in MS that might help promote myelination in other disorders. Some MS therapies are immunomodulatory, for example using gut bacteria, while other seek directly to promote (re)myelination and some clever ones do both. Not surprisingly there is some overlap with autism therapies.

Myelination in Autism
The research does show that myelination in autism is different to that found in most people. It does not look like that found in MS. 

There is less myelin in the brains of people with autism than in those of controls, according to a study published 11 August in Psychological Medicine1. Researchers applied a method that measures myelin in living brains with autism for the first time.
Magnetic resonance imaging (MRI) has previously shown abnormally structured white matter in people with autism. White matter is composed of axons, the long, myelin-coated projections that transmit electrical signals between neurons. 
The researchers looked at myelin content in the brains of 14 young men with autism with a mean age of 24 years and 14 controls with a mean age of 28 years, none of whom have intellectual disabilities. They found that those with autism have less myelin in some brain regions than do controls. In the autism group, those with the most severe social interaction difficulties have the lowest myelin levels.
The researchers speculate that low myelin explains the weak connectivity observed in the brains of people with autism. Without proper insulation, electrical signals travel slowly along the axons, making it difficult for regions of the brain to coordinate their activity. 
Full study:- 

  

Myelin and Learning
Logically you would then look at the role of myelin in both skill acquisition in childhood and then in older age look at a role for myelin in the loss of those very skills.

·        Myelination and skill acquisition

·        Demyelination and loss of skills 

In the case of regressive autism you might consider the role of demyelination in the loss of key skills. This would also apply to the old diagnosis of Childhood Disintegrative Disorders (CDD); perhaps CDD is an extreme case of demyelination.
In middle to older age in typical people we also have brain shrinkage, about 5% per decade.

Myelin, Motor Skills and Broader Cognitive Function
Another issue is whether learning motor skills in particular leads to more myelination as opposed to acquiring non-physical or cognitive skills.  To what extent is there a broader benefit to the brain from all this extra myelination? 
First let’s deal with brain shrinkage. I imagine that in aging there is an element of “use it or lose it”.  

Brain Shrinkage and the Mediterranean Diet 
I am interested in the Mediterranean Diet and the Okinawan Diet, both of which may reveal useful information regarding cognitive function. There will soon be a post on the Okinawan Diet.
The study below is supposed to show how eating the Mediterranean diet can stop your brain shrinking, but it was based on research in Scotland, which is notorious for bad diet and reduced life expectancy particularly in urban areas. There is even something called the Glasgow Effect, trying to explain poor health and shorter lifespan.

Mediterranean diet. 


Data from the Scottish Collaborative Group 168-item Food Frequency Questionnaire, version 7,12,13 were used to construct the MeDi score. Exclusions were made for incomplete data (39 had >10 missing items) and for individuals with extreme energy intakes (<2 .5th="" or="">97.5th centile, n = 46) to obtain the most reliable food frequency data.12 For scoring of the MeDi, we closely followed accepted procedure.14 Briefly, individuals were given a value of 1 for each beneficial food component (fruit, vegetables, legumes, cereal, and fish) and a value of 0 for each detrimental component (meat, dairy). The ratio of daily consumption (in grams) of monounsaturated fatty acids to saturated fatty acids was a further beneficial component. Caloric-adjusted sex-specific medians were used as the boundary defining low and high consumption for each of the components. For beneficial components, scores at or above the median were assigned a value of 1, whereas for detrimental components, scores at or above the median were given a value of 0. Moderate alcohol consumption was another positively scored component. It was defined for men as between 10 and 50 g alcohol per day and for women between 5 and 25 g per day. The MeDi score (range 0–9) was calculated by summing the scores for each of the components, with higher scores indicating higher MeDi adherence. 
There is so much more to the Mediterranean diet, to learn about it you need to go to southern Italy or Greece and see how (rural) people eat; not a deep-fried Mars bar in sight, rather a very wide range of vegetables, fruits, herbs etc that actually taste good.

Objective: To assess the association between Mediterranean-type diet (MeDi) and change in brain MRI volumetric measures and mean cortical thickness across a 3-year period in older age (73–76 years).
Conclusions: Lower adherence to the MeDi in an older Scottish cohort is predictive of total brain atrophy over a 3-year interval. Fish and meat consumption does not drive this change, suggesting that other components of the MeDi or, possibly, all of its components in combination are responsible for the association.

From the LA Times:-

This study likely just compared people with a moderate consumption of fruit and vegetables to the group that ate virtually none at all.

One key part of the Mediterranean diet is the large quantity and variety of herbs that are consumed. This is rarely replicated by foreigners. 

Brain Shrinkage in MS
Brain shrinkage, not surprisingly, is another feature of MS. Here one of the drugs that this blog seems to plug, Ibudilast, seems to be highly beneficial


“In 2016, the drug received Fast Track designation from the US Food and Drug Administration (FDA) to help speed its development as an MS treatment.”

Significantly, the presentation included news that a Phase 2 clinical trial shows the drug slows brain shrinkage and the loss of the protective myelin coating around nerve cells in people with MS.

The Phase 2 SPRINT-MS trial (NCT01982942) tested ibudilast’s safety and effectiveness in progressive MS patients, and their ability to tolerate it.

Ibudilast met the trial’s primary objective of reducing brain shrinkage. “Compared to placebo, ibudilast treatment was associated with a 48% slowing in the rate of atrophy (shrinkage) progression,” 


Acquiring Motor Skills 

The following study suggests that “slow and steady” skill acquisition is likely the best for the brain and that motor skills are the key. 

Experience-dependent structural changes are widely evident in gray matter. Using diffusion weighted imaging (DWI), the neuroplastic effect of motor training on white matter in the brain has been demonstrated. However, in humans it is not known whether specific features of white matter relate to motor skill acquisition or if these structural changes are associated to functional network connectivity. Myelin can be objectively quantified in vivo and used to index specific experience-dependent change. In the current study, seventeen healthy young adults completed ten sessions of visuomotor skill training (10,000 total movements) using the right arm. Multicomponent relaxation imaging was performed before and after training. Significant increases in myelin water fraction, a quantitative measure of myelin, were observed in task dependent brain regions (left intraparietal sulcus [IPS] and left parieto-occipital sulcus). In addition, the rate of motor skill acquisition and overall change in myelin water fraction in the left IPS were negatively related, suggesting that a slower rate of learning resulted in greater neuroplastic change. This study provides the first evidence for experience-dependent changes in myelin that are associated with changes in skilled movements in healthy young adults.  
Our results suggest that myelin is modifiable by experience in humans. Increases in myelin may be aided by oligodendrogenesis associated with behavioral changes, as has been demonstrated in a mouse model using optogenetic stimulation [9]. Even modest increases in myelination may

result in large increases in signal propagation speed resulting in more rapid information transfer between gray matter processing centers and improved synchrony between distant cortical regions [7].These results provide insights into tissue specific experience-dependent changes in white matter. Our findings may have important clinical implications and future investigations should evaluate the effect of intensive motor practice on myelin plasticity in individuals with neurologic conditions (e.g., stroke or those with demyelinating diseases such as multiple sclerosis) in order to assess the efficacy of behavioural training on myelin plasticity in the diseased brain.  


New evidence of myelin’s essential role in learning and retaining new practical skills, such as playing a musical instrument, has been uncovered by UCL research. Myelin is a fatty substance that insulates the brain's wiring and is a major constituent of ‘white matter’. It is produced by the brain and spinal cord into early adulthood as it is needed for many developmental processes, and although earlier studies of human white matter hinted at its involvement in skill learning, this is the first time it has been confirmed experimentally.
For a child to learn to walk or an adult to master a new skill such as juggling, new brain circuit activity is needed and new connections are made across large distances and at high speeds between different parts of the brain and spinal cord. For this, electrical signals fire between neurons connected by “axons” – thread-like extensions of their outer surfaces which can be viewed as the ‘wire’ in the electric circuit. When new signals fire repeatedly along axons, the connections between the neurons strengthen, making them easier to fire in the same pattern in future. Neighbouring myelin-producing cells called oligodendrocytes (OLs) recognise the repeating signal and wrap myelin around the active circuit wiring. It is this activity-driven insulation that the team identified as essential for learning.    

Novel Treatments for Multiple Sclerosis  (MS)
In a recent phase II clinical trial, an over-the-counter allergy drug was shown to improve nervous system function in patients with multiple sclerosis.
See the section further below on P2X7, for the reason why an antihistamine can help myelination.

Of the three strains of bacteria, one known as Prevotella histicola effectively suppressed MS in the mice. Specifically, P. histicola produced a drop in two cell types that encourage inflammation, which are known as pro-inflammatory cytokines.Conversely, it increased the level of certain cell types that fight disease, including dendritic cells, T cells, and a type of macrophage. Overall, inflammation and demyelination were reduced, about which the researchers are excited but cautious.
The current findings knit together with other recent studies in a similar vein - for instance, studies looking at MS patients' microbiomes have found lower levels of bacteria in the Prevotella genus. Similarly, levels of Prevotella have been shown to increase when MS patients take drugs that combat the condition.
Another neat dovetail is that Western diets promote an abundance of Bacteroides, whereas a high-fiber agrarian, or cereal-based, diet seems to encourage increased levels of Prevotella, marking another trail of clues to follow.
Although the study has concentrated on MS, the scope of these findings is much broader. First study author Ashutosh Mangalam, Ph.D. - from the University of Iowa Carver College of Medicine in Iowa City - says, "[...] it's not just for MS, because this may have a similar modulating effect on other nervous system and autoimmune diseases."  

Dr. Spain and colleagues suggest that lipoic acid - a naturally occurring antioxidant that is available as an over-the-counter supplement - could be an effective treatment for SPMS (secondary progressive multiple sclerosis), after finding that it helped to reduce the rate of whole brain atrophy among patients with the condition.
Compared with participants who took the placebo, the researchers found that those who took lipoic acid showed a 68 percent reduction in the rate of whole brain atrophy.


Purinergic signaling in Inflammation 
Purinergic signaling is complex and only partially understood. There are three types of purinergic receptor:- 
·        P1 receptors which are activated by adenosine

·        P2Y receptors which are activated by nucleotides, primarily ATP

·        P2X receptors which are activated by ATP

Purinergic signaling is involved in just about every process in humans, to the extent that the purinergic signalling complex of a cell is referred to as the “purinome”.
In this very superficial review we are just looking at inflammation.
Purinergic signaling is an important mechanism in a wide range of inflammatory diseases. There are many instances in which signaling events initiated by adenosine P1 receptors and those initiated by nucleotide P2 receptors have opposing effects in biologic systems, and shifting the balance between purinergic P1 and P2 signaling is an emerging therapeutic concept in efforts to dampen pathologic inflammation and promote healing.
Pharmacologic P2-receptor antagonists inhibit inflammation such as that which occurs in inflammatory bowel disease (IBD), lung inflammation, and ischemia. 
In pathologic conditions such as asthma and vascular inflammation, P2-receptor knockout mice are protected from inflammatory diseases.
Examples of nucleotide ­receptor signaling in inflammatory conditions include P2Y6­ or P2X7­receptor signaling, which mediates vascular inflammation P2Y1­, P2X1­, and P2Y12 ­receptor signaling, which mediates platelet activation. Activation of P2 receptors of the P2Y2 and P2X7 family that are expressed on dendritic cells is thought to play a role in promoting lung inflammation in chronic lung diseases such as asthma. 
P2X7 receptors are known to play a key role in mast cell degranulation and hence allergies.


The results indicate that P2X7 receptors may play a significant role in contributing to the unwanted activation of mast cells in chronic inflammatory conditions where extracellular ATP levels are elevated.

 Note that at times of inflammation the level of extracellular ATP is elevated.  

Not so simple - P2X7 in MS
As mentioned earlier purinergic signaling is complex and only partially understood. In an inflammatory condition like MS, P2X7 appears very likely to be involved, but is it having a good or bad effect? The answer is both, as you can see in the paper below.

The right question to ask becomes is the net effect of P2X7 signaling good or bad?  

Multiple sclerosis (MS) is characterized by macrophage accumulation and inflammatory infiltrates into the CNS contributing to demyelination. Because purinergic P2X7 receptor (P2X7R) is known to be abundantly expressed on cells of the hematopoietic lineage and of the nervous system, we further investigated its phenotypic expression in MS and experimental autoimmune encephalomyelitis conditions. By quantitative reverse transcription polymerase chain reaction and flow cytometry, we analyzed the P2X7R expression in human mononuclear cells of peripheral blood from stable and acute relapsing-remitting MS phases. Human monocytes were also challenged in vitro with pro-inflammatory stimuli such as the lipopolysaccharide, or the P2X7R preferential agonist 2'(3')-O-(4 Benzoylbenzoyl)adenosine 5'-triphosphate, before evaluating P2X7R protein expression. Finally, by immunohistochemistry and immunofluorescence confocal analysis, we investigated the P2X7R expression in frontal cortex from secondary progressive MS cases. We demonstrated that P2X7R is present and inhibited on peripheral monocytes isolated from MS donors during the acute phase of the disease, moreover it is down-regulated in human monocytes after pro-inflammatory stimulation in vitro. P2X7R is instead up-regulated on astrocytes in the parenchyma of frontal cortex from secondary progressive MS patients, concomitantly with monocyte chemoattractant protein-1 chemokine, while totally absent from microglia/macrophages or oligodendrocytes, despite the occurrence of inflammatory conditions. Our results suggest that inhibition of P2X7R on monocytes and up-regulation in astrocytes might contribute to sustain inflammatory mechanisms in MS. By acquiring further knowledge about P2X7R dynamics and identifying P2X7R as a potential marker for the disease, we expect to gain insights into the molecular pathways of MS.  

A recent trial has shown that the common H1 antihistamine Clemastine is therapeutic in MS.
Clemastine is seen as a positive allosteric modulator of P2X7, meaning that it increases P2X7 signaling. In our superficial view of the science increasing P2X7 signaling looks like a crazy idea to treat an inflammatory condition.
As you can see in the paper below increasing P2X7 signaling has a pro-inflammatory effect and an anti-inflammatory effect.
What matters is the net effect and that will vary depending on the exact type and location of the inflammatory activity.
In the case of MS, the net effect of increasing P2Y7 is highly beneficial.  

Because clinical data do not hint to severe or obvious clemastine-induced adverse drug responses that may involve P2X7 potentiation, augmentation of P2X7 activity in the presence of therapeutic concentrations of the antihistamine possibly exert more subtle changes that require a more thorough and focused evaluation. In addition, although we demonstrated release of the proinflammatory cytokine IL-1β from hMDM, P2X7 activation also gives rise to production and secretion of IL-1 receptor antagonist (IL-1Ra), which is in turn expected to exert anti-inflammatory activity (52,,54). Hence, the pro- or anti-inflammatory net effect of a clemastine-induced P2X7 potentiation may additionally depend on the targeted cell type, local availability of ATP, and pathophysiological background. An accumulating body of evidence points to a beneficial role of P2X7 activation in monocytes and macrophages to contribute to elimination of intracellularly located parasites and mycobacteria (55, 56). Even more strikingly, P2X7 activation in dendritic cells chiefly contributes to the orchestration of the adaptive antitumor immunity by triggering the caspase-1-dependent inflammasome activation in dendritic cells followed by IL-1β secretion and priming of interferon γ-producing CD8+ T cells (57). Therefore, selective P2X7 activators or positive allosteric modulators are intensely sought. In addition, the use of P2X7 activators, by triggering apoptotic cell death, has been put forward as a concept to treat several malignancies (Ref. 58 and references therein). Thus, the approved drug clemastine may serve as an interesting and immediately available starting point to explore these mechanisms in clinical settings.  

Full results from a randomized controlled trial (RCT) suggest that the over-the-counter (OTC) antihistamine clemastine fumarate is safe and effective for treating chronic demyelinating injury in multiple sclerosis (MS)֫ — even in patients who have had symptoms of myelin degeneration for years.

Although preliminary results were presented at the annual American Academy of Neurology meeting last year, full data from the ReBUILD trial were published online October 10 in the Lancet. 


Why P2X7 as the mode of action in MS? 
You may be asking why has Peter assumed that P2X7 is the helpful mode of action of Clemastine in treating MS, nobody else seems to highlight this.
Clemastine is an H1 antihistamine and as such does also have so-called cholinergic effects, meaning it act like the hormone acetylcholine. 
There is a whole class of drugs that increase the amount of  acetylcholine, by inhibiting cholinerases which normally act to degrade acetylcholine.
So if acetylcholine was magical for MS, then you would expect an acetylcholinerase inhibitor like Donepezil to work wonders for MS.  It has been trialed at least twice.


“A small study followed 69 people with MS taking either donepezil or a placebo for 24 weeks. It found that twice as many people in the treatment group reported memory improvement (65.7%) than those on placebo (32.4%). Health professionals also reported that more people in the treatment group showed improved cognitive symptoms. However, a larger study involving 120 people with MS showed no difference in improving memory between donepezil and placebo


Of course there is some existing research showing the role of P2X7 in MS:- 


How about P2X7 more broadly in Neurological Conditions? 


Highlights 


·         P2X7 receptor channels allow the passage of both small and large molecular weight cations.
·         P2X7Rs are expressed on all different cell types of the CNS but their expression is highly dependent on external stimuli.
·         P2X7Rs contribute to various neurodegenerative diseases.
·         P2X7Rs may participate in the pathophysiology of psychiatric disorders.
The ATP-sensitive homomeric P2X7 receptor (P2X7R) has received particular attention as a potential drug target because of its widespread involvement in inflammatory diseases as a key regulatory element of the inflammasome complex. However, it has only recently become evident that P2X7Rs also play a pivotal role in central nervous system (CNS) pathology. There is an explosion of data indicating that genetic deletion and pharmacological blockade of P2X7Rs alter responsiveness in animal models of neurological disorders, such as stroke, neurotrauma, epilepsy, neuropathic pain, multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), Alzheimer's disease, Parkinson's disease, and Huntington's disease. Moreover, recent studies suggest that P2X7Rs regulate the pathophysiology of psychiatric disorders, including mood disorders, implicating P2X7Rs as drug targets in a variety of CNS pathology.


P2X7 in Schizophrenia:-

P2X7 receptors (P2X7Rs) are ligand-gated ion channels sensitive to extracellular ATP. Here we examined for the first time the role of P2X7R in an animal model of schizophrenia. Using the PCP induced schizophrenia model we show that both genetic deletion and pharmacological inhibition of P2X7Rs alleviate schizophrenia-like behavioral alterations. In P2rx7+/+ mice, PCP induced hyperlocomotion, stereotype behavior, ataxia and social withdrawal. In P2X7 receptor deficient mice (P2rx7−/−), the social interactions were increased, whereas the PCP induced hyperlocomotion and stereotype behavior were alleviated. The selective P2X7 receptor antagonist JNJ-47965567 partly replicated the effect of gene deficiency on PCP-induced behavioral changes and counteracted PCP-induced social withdrawal. We also show that PCP treatment upregulates and increases the functional responsiveness of P2X7Rs in the prefrontal cortex of young adult animals. The amplitude of NMDA evoked currents recorded from layer V pyramidal neurons of cortical slices were slightly decreased by both genetic deletion of P2rx7 and by JNJ-47965567. PCP induced alterations in mRNA expression encoding schizophrenia-related genes, such as NR2A, NR2B, neuregulin 1, NR1 and GABA α1 subunit were absent in the PFC of young adult P2rx7−/− animals. Our findings point to P2X7R as a potential therapeutic target in schizophrenia.

More on Clemastine for MS in plain English:-


Modulating P2X7 with H1 antihistamines
Using 2 existing antihistamine drugs you can either increase or decrease the response from P2X7 receptors.
The complication is that pro or anti-inflammatory effect of P2X7 varies depending on which cell types are involved. So it is not so obvious whether a particular condition wants more or less P2X7 activity.  
In the case of MS a positive allosteric modulator of P2X7 (Clemastine) helps. In some other condition it may need the opposite, a P2X7 antagonist (Oxatomide).
Both Clemastine and Oxatomide are well understood inexpensive antihistamines, in many countries Clemastine is OTC. Oxatomide (Tinset) seems very popular in Italy. 

Because clinical data do not hint to severe or obvious clemastine-induced adverse drug responses that may involve P2X7 potentiation, augmentation of P2X7 activity in the presence of therapeutic concentrations of the antihistamine possibly exert more subtle changes that require a more thorough and focused evaluation. In addition, although we demonstrated release of the proinflammatory cytokine IL-1β from hMDM, P2X7 activation also gives rise to production and secretion of IL-1 receptor antagonist (IL-1Ra), which is in turn expected to exert anti-inflammatory activity (52,,54). Hence, the pro- or anti-inflammatory net effect of a clemastine-induced P2X7 potentiation may additionally depend on the targeted cell type, local availability of ATP, and pathophysiological background. An accumulating body of evidence points to a beneficial role of P2X7 activation in monocytes and macrophages to contribute to elimination of intracellularly located parasites and mycobacteria (55, 56). Even more strikingly, P2X7 activation in dendritic cells chiefly contributes to the orchestration of the adaptive antitumor immunity by triggering the caspase-1-dependent inflammasome activation in dendritic cells followed by IL-1β secretion and priming of interferon γ-producing CD8+ T cells (57). Therefore, selective P2X7 activators or positive allosteric modulators are intensely sought. In addition, the use of P2X7 activators, by triggering apoptotic cell death, has been put forward as a concept to treat several malignancies (Ref. 58 and references therein). Thus, the approved drug clemastine may serve as an interesting and immediately available starting point to explore these mechanisms in clinical settings.

P2X7 receptor antagonist activityof the anti-allergic agent oxatomide. 

Abstract


Activation of the P2X7 receptor by extracellular ATP is associated with various immune responses including allergic inflammation. Anti-allergic agents, such as H1-antihistamines, are known to inhibit the effects of different chemical mediators such as acetylcholine and platelet-activating factor. Therefore, we hypothesized that some anti-allergic agents might affect P2X7 receptor function. Using N18TG2 and J774 cells, which express functional P2X7 receptors, the effects of several anti-allergic agents on P2X7 receptor function were investigated by monitoring the ATP-induced increase in intracellular Ca(2+) concentrations ([Ca(2+)]i). Among the various agents tested, oxatomide significantly inhibited P2X7 receptor-mediated [Ca(2+)]i elevation in a concentration-dependent manner without affecting the P2Y2 receptor-mediated response in both N18TG2 and J774 cells. Consistently, oxatomide inhibited P2X7 receptor-mediated membrane current and downstream responses such as mitogen-activated protein kinase activation, inflammation-related gene induction, and cell death. In addition, oxatomide inhibited P2X7 receptor-mediated degranulation in mouse bone marrow-derived mast cells. Whole cell patch clamp analyses in HEK293 cells expressing human, mouse, and rat P2X7 receptors revealed that the inhibitory effect of oxatomide on ATP-induced current was most prominent for the human P2X7 receptor and almost non-existent for the rat P2X7 receptor. The potent inhibitory effects of oxatomide on human P2X7 receptor-mediated function were confirmed in RPMI8226 human B cell-like myeloma cells, which endogenously express the P2X7 receptor. Our results demonstrated that the antihistamine oxatomide also acts as a P2X7 receptor antagonist. Future studies should thus evaluate whether P2X7 receptor antagonism contributes to the anti-allergic effects of oxatomide. 

Other ideas for MS? 
How about immunomodulation by antibiotic to treat MS? We have seen how macrolide antibiotics have immunomodulatory properties, but so do both (fluoro)quinolones and tetracyclines. In MS it is the tetracycline antibiotic minocycline that has the desired immunomodulatory effect. This is another  cheap way to treat MS. Minocycline is a common antibiotic often used to treat acne. In my earlier post we looked at Azithromycin and the idea of modifying such a drug to stop being an antibiotic but retain the immune-modulating property.
There will be a post on (fluoro)quinolones and tetracyclines in the near future.

My earlier post.

Conclusion
If you have MS a PDE4 inhibitor like Ibudilast looks a good idea. Ibudilast is currently only licensed in Japan, where it has long been used for asthma. In the West a different PDE4 inhibitor called Daxas/Roflumilast is approved to treat COPD and we saw in an earlier post that at one fifth of the regular dose it seems to treat sensory gating impairments and also improve cognition in some.
Clemastine, an OTC antihistamine in many countries, shows improved myelination in MS. I suspect the mode of action relates to P2X7.
The cheap tetracycline antibiotic Minocycline is likely another good choice. 
In people with mitochondrial disease, who lose skills, it appears that remyelination may be disturbed and they may be the most likely subgroup of autism that might benefit from the therapies that increase myelination.
Some of the MS therapies are “just” anti-inflammatory and by blunting the immune response, they remove a barrier to remyelination.
A PDE4 inhibitor is anti-inflammatory but it also increases something we have come across called PKA (protein kinase A). If you want myelin you want to activate PKA.
How about autism (and big brother, schizophrenia)? I think much of what helps MS may help at least some autism and vice versa.
For autism the Prevotella histicola bacteria looks interesting and quite possibly more or less P2X7R activity is going to help some autism/schizophrenia.



The yellow box means, we know it works, at least for some people, based on trial results.  

Regarding aging we know that learning new activities, physical activity and avoiding a terrible diet are all good ways to slow your brain shrinking.
Learning a new language, at any age is good for you, but if you are lucky enough to do this from birth you have less chance of dementia later on.
Very recent research shows the benefit of being bilingual if you happen to be autistic. Having strictly defined autism means you will not appear fluent in either language, but you have learnt that there at least two ways of doing the same thing. Some people with autism are extremely inflexible, but if you are bilingual there are two ways to ask for everything and you learnt this as soon as you started to speak.
In the first study of its kind, scientists show that bilingual children with autism spectrum disorders can switch mental gears more easily than those who can only speak one language.
A focus on developing/improving motor skills from a very early age in those even suspected of having autism may well have much broader cognitive benefits.
It is best not to accept sloppy handwriting and lack of coordination when playing ball; gradually improving these skills will pay broader dividends.
Going back to the start of this post and what Monty’s old assistant might do with her new young learner with poor fine motor skills, my advice was to ignore the psychologist and spend half an hour a day practicing fine motor skills with a photocopiable workbook like this one, that years ago she used with Monty:-


I have to make sure to ask for it back !