Refining Antioxidant (ROS & RNS) Therapy in Autism - Selenium and Molybdenum

Today’s post is about further refining antioxidant therapy.

As we saw in a recent post, oxidative and nitrosative stress is a very common feature of autism and is treatable with OTC products.

The cheapest antioxidant, N-acetylcysteine (NAC), looks to be the best one, but there are numerous others with exotic names and equally exotic prices.

Today we just look at selenium and molybdenum.  Selenium was on my to-do list for a long time because it affects some key enzymes call GP_X (glutathione peroxodases).

Molybdenum was enthusiastically recommended in a recent comment and this blog has previously touched on Molybdenum Cofactor Sulfurase (MOCOS).

Rather surprisingly, there is a commercial product that contains NAC, Selenium and Molybdenum. 

Selenium and GP_X (glutathione peroxodases)

There are eight different glutathione peroxodases, but GPx1, GPx2, GPx3, and GPx4 are all made from selenium.

GP_X speeds up the antioxidant reactions that involve glutathione (GSH).

In autism we know that both GSH and GP_X are lacking.

We know how to make more GSH, just take some NAC.  But what about the catalyst GP_X? 

There may be an equally easy way to increase that. 

Selenium and Thyroid  Enzymes

Selenium is also part of the three deiodinase enzymes D1, D2 and D3.

The active thyroid hormone is called T3, but most of what is circulating in your body is the inactive pro-hormone form called T4.

Deiodinase 1 (D1)  both activates T₄ to produce T₃ and inactivates T₄. Besides its increased function in producing extrathyroid T₃, its function is less well understood than D2 or D3.

Deiodinase 2 (D2), located in the ER membrane, converts T₄ into T₃ and is a major source of the cytoplasmic T₃ pool.  It looks like some people with autism may lack D2 in their brain.

Deiodinase 3 (D3) prevents T₄ activation and inactivates T₃. It looks like some people with autism have too much D3 in their brain.

D2 and D3 are important in homeostatic regulation in maintaining T₃ levels at the plasma and cellular levels.

·        In hyperthyroidism D2 is down regulated and D3 is upregulated to clear extra T₃

·        in hypothyroidism D2 is upregulated and D3 is downregulated to increase cytoplasmic T₃ levels

Serum T3 levels remain fairly constant in healthy individuals, but D2 and D3 can regulate tissue specific intracellular levels of T3 to maintain homeostasis since T3 and T4 levels may vary by organ.  

It appears that some people with autism may have central hyperthyroidism, meaning in their brain.

Regular readers may recall this post:-

Central Hypothyroidism or Low Brain D2 Levels in Autism

The major source of the biologically active hormone T3 in the brain is the local intra-brain conversion of T4 to T3, while a small fraction comes from circulating T3. 

As evidence derived from in vitro studies suggests, in response to oxidative stress D3 increases while D2 decreases (Lamirand et al., 2008; Freitas et al., 2010).  As we know in the autistic brain we have a lot of oxidative stress.

Furthermore, in ASD, the lower intra-brain T3 levels occur in the

Absence of a systemic T3 deficiency (Davis et al., 2008), most likely due to the increased activity of D3.

So in some autistic brains we have too much D3 which is inactivating T3 and preventing T4 being converted to T3.

Reduced D2 is reducing the conversion of T4 to T3. 

We would therefore want to increase D2 in some autism.

This can be achieved by:-

·        Reducing oxidative stress, which we are already sold on. 

·        We can also potentially upregulate the gene that produces D2 using some food-based genetic therapy. Kaempferol (KPF) appears to work and may explain why broccoli sprout powder makes some people go hyper and some others cannot sleep  

The Small Polyphenolic Molecule Kaempferol Increases Cellular Energy Expenditure and Thyroid Hormone Activation

The cAMP-responsive gene for type 2 iodothyronine deiodinase (D2), an intracellular enzyme that activates thyroid hormone (T3) for the nucleus, is approximately threefold upregulated by KPF

·        Perhaps low levels of selenium differentially affect the synthesis of D1, D2 and D3?

  

Where does selenium come from? 

We know from Chauham/James that selenium levels are reduced in autism, but we also know that selenium levels vary widely by geography.  

You get selenium from your diet and the level of selenium in the soil varies widely.  It is widely held that most healthy people should have plenty selenium in their diet. 

In the following paper there is an analysis of Selenium status in Europe and the Middle East.

Since we have plenty of Polish readers I have included the chart with the Polish data (on the left).  It shows that Polish people may be a little deficient in selenium.

You can see the level of selenium in Poland is below that needed to optimise plasma GPx activity.

So if you already have reduced GPx activity, because of autism, and you really need to make the most of your limited glutathione (GSH) because you have oxidative/nitrosative stress, then a little extra selenium could be just what the doctor should have ordered.

  

A Review of Dietary Selenium Intake and Selenium Status in Europe and the Middle East

Se is an essential non-metal trace element [3] that is required for selenocysteine synthesis and is essential for the production of selenoproteins [4]. Selenoproteins are primarily either structural or enzymatic [2], acting as catalysts for the activation of thyroid hormone and as antioxidants, such as glutathione peroxidases (GPxs) [5]. GPx activity is commonly used as a marker for Se sufficiency in the body [6], where serum or plasma Se concentrations are believed to achieve maximum GPx expression at 90–100 μg/L (90.01 μg/L as proposed by Duffield and colleagues [7] and 98.7 μg/L according to Alfthan et al. [8]). However, plasma selenoprotein P (SEPP1) concentration is a more suitable marker than plasma GPx activity [9]. Prospective studies provide some evidence that adequate Se status may reduce the risk of some cancers, while elevated risk of type 2 diabetes and some cancers occurs when the Se concentration exceeds 120 μg/L [10]. Higher Se status has been linked to enhanced immune competence with better outcomes for cancer, viral infections, including HIV progression to AIDS, male infertility, pregnancy, cardiovascular disease, mood disorders [2] and, possibly, bone health [11–14].

  

Selenium and NAC for Rats with TBI

Perhaps not surprisingly, selenium and NAC have been found beneficial for Rats unfortunate enough to have sufferred a traumatic brain injury (TBI).

 N-Acetylcysteine and Selenium Modulate Oxidative Stress, Antioxidant Vitamin and Cytokine Values in Traumatic Brain Injury-Induced Rats

It has been suggested that oxidative stress plays an important role in the pathophysiology of traumatic brain injury (TBI). N-acetylcysteine (NAC) and selenium (Se) display neuroprotective activities mediated at least in part by their antioxidant and anti-inflammatory properties although there is no report on oxidative stress, antioxidant vitamin, interleukin-1 beta (IL)-1β and IL-4 levels in brain and blood of TBI-induced rats. We investigated effects of NAC and Se administration on physical injury-induced brain toxicity in rats. Thirty-six male Sprague–Dawley rats were equally divided into four groups. First and second groups were used as control and TBI groups, respectively. NAC and Se were administrated to rats constituting third and forth groups at 1, 24, 48 and 72 h after TBI induction, respectively. At the end of 72 h, plasma, erythrocytes and brain cortex samples were taken. TBI resulted in significant increase in brain cortex, erythrocytes and plasma lipid peroxidation, total oxidant status (TOS) in brain cortex, and plasma IL-1β values although brain cortex vitamin A, β-carotene, vitamin C, vitamin E, reduced glutathione (GSH) and total antioxidant status (TAS) values, and plasma vitamin E concentrations, plasma IL-4 level and brain cortex and erythrocyte glutathione peroxidase (GSH-Px) activities decreased by TBI. The lipid peroxidation and IL-1β values were decreased by NAC and Se treatments. Plasma IL-4, brain cortex GSH, TAS, vitamin C and vitamin E values were increased by NAC and Se treatments although the brain cortex vitamin A and erythrocyte GSH-Px values were increased through NAC only. In conclusion, NAC and Se caused protective effects on the TBI-induced oxidative brain injury and interleukin production by inhibiting free radical production, regulation of cytokine-dependent processes and supporting antioxidant redox system.

  

Dietary selenium stabilizes glutathione peroxidasemRNA in rat liver

  

And now to Molybdenum 

Molybdenum (Mo) is a trace dietary element necessary for human survival.

Low soil concentration of molybdenum in a geographical band from northern China to Iran results in a general dietary molybdenum deficiency, and is associated with increased rates of esophageal cancer.  Compared to the United States, which has a greater supply of molybdenum in the soil, people living in those areas have about 16 times greater risk for esophageal cancer.
So you would not want to have molybdenum deficiency.

Four Molybdenum-dependent enzymes are known, all of them include molybdenum cofactor (Moco) in their active site: sulfite oxidase, xanthine oxidoreductase, aldehyde oxidase, and mitochondrial amidoxime reductase.

Moco cannot be taken up as a nutrient, and thus it requires to made in your body from molybdenum.

If your body cannot make enough Moco you may develop what is called molybdenum cofactor deficiency, which would ultimately kill you. It is ultra rare.

Symptoms include early seizures, low blood levels of uric acid, and high levels of sulphite, xanthine, and uric acid in urine.


When caused by a mutation in the MOCS1 gene it is called the type A variant.

Molybdenum cofactor deficiency may indeed be extremely rare, but MOCS1 is a known autism gene.  Perhaps there exists partial molybdenum cofactor deficiency, which is not rare at all?

Source:-  Identification of candidate intergenic risk loci in autism spectrum disorder

MOCOS (Molybdenum cofactor sulfurase)


Molybdenum cofactor sulfurase is an enzyme that in humans is encoded by the MOCOS gene.

MOCOS sulfurates the molybdenum cofactor of xanthine dehydrogenase (XDH) and aldehyde oxidase (AOX1), which is required for their enzymatic activities.

MOCOS is downregulated in autism and is suggested to induce increased oxidative-stress sensitivity, which would not be good.

So it looks like we need a clever way to upregulate MOCOS.

You need adequate molybdenum cofactor (Moco), for which you do need adequate molybdenum.

You need the genes MOCS1 and MOCOS to be correctly expressed.

SIRT1 activation, which is a future therapy for Alzheimer’s, is suggested to increase MOCOS, as may NRF2.

Sirtuin-activating compounds (STAC) are chemical compounds having an effect on sirtuins, a group of enzymes that use NAD+ to remove acetyl groups from proteins. They are molecules able to prevent aging related diseases like Alzheimer's, diabetes, and obesity.  There is quite a long list that includes ranges from polyphenols such as resveratrol, the flavonols fisetin, and quercetin also butein, piceatannol, isoliquiritigenin,

Fisetin is found in strawberries, cucumbers and supplements.  In normal animals, fisetin can improve memory; it also can have an effect on animals prone to Alzheimer's.

Modulation of p25 and inflammatory pathways by fisetin maintains cognitive function in Alzheimer's disease transgenic mice

Here is the excellent French paper on MOCOS:-

Olfactory stem cells reveal MOCOS as a new player in autism spectrum disorders

With an onset under the age of 3 years, autism spectrum disorders (ASDs) are now understood as diseases arising from pre- and/or early postnatal brain developmental anomalies and/or early brain insults. To unveil the molecular mechanisms taking place during the misshaping of the developing brain, we chose to study cells that are representative of the very early stages of ontogenesis, namely stem cells. Here we report on MOlybdenum COfactor Sulfurase (MOCOS), an enzyme involved in purine metabolism, as a newly identified player in ASD. We found in adult nasal olfactory stem cells of 11 adults with ASD that MOCOS is downregulated in most of them when compared with 11 age- and gender-matched control adults without any neuropsychiatric disorders. Genetic approaches using in vivo and in vitro engineered models converge to indicate that altered expression of MOCOS results in neurotransmission and synaptic defects. Furthermore, we found that MOCOS misexpression induces increased oxidative-stress sensitivity. Our results demonstrate that altered MOCOS expression is likely to have an impact on neurodevelopment and neurotransmission, and may explain comorbid conditions, including gastrointestinal disorders. We anticipate our discovery to be a fresh starting point for the study on the roles of MOCOS in brain development and its functional implications in ASD clinical symptoms. Moreover, our study suggests the possible development of new diagnostic tests based on MOCOS expression, and paves the way for drug screening targeting MOCOS and/or the purine metabolism to ultimately develop novel treatments in ASD.  

Lately, a diminished seric expression of glutathione, glutathione peroxidase, methionine and cysteine has been highlighted in a meta-analysis from 29 studies on ASD subjects.⁴⁵ Along this line, purines and purine-associated enzymes are recognized markers of oxidative stress. ROS are generated during the production of uric acid, catalyzed by xanthine oxidase and XDH.⁴⁶ Conversely, uric acid is nowadays recognized as a protective factor acting as a ROS scavenger.^{47, 48} Interestingly, allopurinol, a xanthine oxidase inhibitor, was found efficient in reducing symptoms, especially epileptic seizures, in ASD patients displaying high levels of uric acid.⁴⁹ However, in our cohort, only 3 out of 10 patients exhibited an abnormal uric acid secretion. It can therefore be postulated that still unknown other MOCOS-associated mechanisms may have a role in the unbalanced stress response observed in ASD OSCs.

Identifying and manipulating downstream effectors of MOCOS will be the next critical step to better understand its mechanisms of action. In parallel, we plan to ascertain some of its upstream regulators. For example, bioinformatic analyses revealed that the promoter region of MOCOS includes conserved binding sites for transcription factors such as GATA3 and NRF2. In addition, other putative interactors, such as the NAD-dependent deacetylase sirtuin-1 (SIRT1), may have a regulatory role on MOCOS expression. Interestingly, these three genes have been associated with ASD, fragile X syndrome, epilepsy and/or oxidative stress.^{54, 55, 56, 57} In conclusion, our study opens an unexplored new avenue for the study of MOCOS in ASD, and could set bases for the development of new diagnostic tools as well as the search of new therapeutics.

Conclusion

It looks like a little extra selenium may be in order to increase those GPx enzymes that are need to speed up aspects of the antioxidant activity of GSH.

When it comes to molybdenum, things get much more complex. You certainly do not want to be deficient in molybdenum and you do not want Molybdenum cofactor deficiency; you also do not want molybdenum cofactor Sulfurase (MOCOS) mis-expression.

It is fair to say that quite likely there is a problem related to molybdenum that affects oxidative stress in autism; but it is not yet clear what to do about it.  I rather doubt the solution is as simple as just a little extra molybdenum, but it is easy to try.

On the plus side, we see that if you have autism, epilepsy and high uric acid you are likely to benefit from allopurinol, which also seems to help in COPD.

There is nothing new about allopurinol possibly be effective in some autism, as from this 25 year old book, Diagnosis and Treatment of Autism.

Again we see that activating NRF2 looks a good idea, that applies to both autism and COPD.

One thing to note is that NRF2 activators are good for cancer prevention, but if you have a cancer you want NRF2 inhibitors.

NRF2 activators include sulforaphane (SFN), R-alphalipoic acid (ALA), resveratrol and curcumin.  SFN is by far the most potent.  Resveratrol and curcumin have a problem with bioavailability.

Inflammation Leading to Cognitive Dysfunction

Today’s post highlights a paper with some very concise insights into how microglial cells become “activated” resulting in the “exaggerated inflammatory response” that many people with autism experience on a daily basis.  

This is very relevant to treatment, which is not usually the objective of much autism research.

I recall reading a comment from John’s Hopkins about neuroinflammation/activated microglia in autism; they commented that no known therapy currently exists and that, of course, common NSAIDs like ibuprofen will not be effective.  But NSAIDs are effective.

As we see in today’s paper, there a least 4 indirect cytokine-dependent pathways leading to the microglia, plus one direct one.

NSAIDs most definitely can reduce cytokine signaling and thus, indirectly, reduce microglial activation.

The ideal therapy would act directly at the microglia, and as Johns Hopkins pointed out, that does not yet exist with today's drugs.  If you read the research on various natural flavonoids you will see that “in vitro” there are known substances with anti-neuroinflammatory effects on microglial activation.  The recurring “problem” with such substances is low bioavailability and inability to cross the blood brain barrier.

Back to Today’s Paper

It was a conference paper at the 114th Abbott Nutrition Research Conference - Cognition and Nutrition

The full conference proceedings can be downloaded

The paper is not about autism, it is about more general cognitive dysfunction.  It is from mainstream science (I checked).

It explains how inflammation anywhere in the body can be translated across the BBB (Blood Brain Barrier) to activate the microglia.  This of course allows you to think of ways to counter these mechanisms.

It also raises the issue of whether or not anti-inflammatory agents really need to cross the BBB.  While you might think that ability to cross the BBB is a perquisite to mitigate the activated microglia, this may not be the case.  Much can be achieved outside the BBB, and we should not rule out substances that cannot cross the BBB.

Very many known anti-inflammatory substances do not cross the BBB.   

  

From Inflammation to Sickness and Cognitive Dysfunction: When the Immune System Subjugates the Brain

extracts from the above paper ...

Example – Influenza and Cognition

Neurological and cognitive effects associated with influenza infection have been reported throughout history.

The simplest explanation for these neurocognitive effects is that influenza virus makes its way to the brain, where it is detected by neurons.

However, most influenza strains, including those responsible for pandemics, are considered non-neurotropic, neurological symptoms associated with influenza infection are not a result of direct viral invasion into the CNS.

Moreover, neurons do not have receptors to detect viruses (or other pathogens) directly.

Cells of the immune system do, however, as the immune system’s primary responsibility is to recognize infectious pathogens and contend with them. For example, sentinel immune cells such as monocytes and macrophages are equipped with toll-like receptors (TLR) that recognize unique molecules associated with groups of pathogens (i.e., pathogen-associated molecular patterns). Stimulation of TLRs that recognize viruses (TLR3 and TLR7) and bacteria (TLR4) on immune sentinel cells can have profound neurological and cognitive effects, suggesting the immune system conveys a message to the brain after detecting an infectious agent. This message is cytokine based.

Macrophages and monocytes produce inflammatory cytokines (e.g., interleukin [IL]-1β, IL-6, and tumor necrosis factor-α [TNF-α]) that facilitate communication between the periphery and brain.

Cytokine-dependent Pathways to the Brain

Several cytokine-dependent pathways that enable the peripheral immune system to transcend the blood-brain barrier have been dissected.

Inflammatory cytokines present in blood can be actively transported into the brain.

But there are also four indirect pathways:-

1.     Cytokines produced in the periphery need not enter the brain to elicit neurocognitive changes. This is because inflammatory stimuli in the periphery can induce microglial cells to produce a similar repertoire of inflammatory cytokines. Thus, brain microglia recapitulates the message from the peripheral immune system.

2.     in a second pathway, inflammatory cytokines in the periphery can bind receptors on blood-brain barrier endothelial cells and induce perivascular microglia or macrophages to express cytokines that are released into the brain

3.     In a third pathway, cytokines in the periphery convey a message to the brain via the vagus nerve. After immune challenge, dendritic cells and macrophages that are closely associated with the abdominal vagus have been shown to express IL-1β protein; IL-1 binding sites have been identified in several regions of the vagus as well. When activated by cytokines, the vagus can activate specific neural pathways that are involved in neurocognitive behavior. However, activation of the vagus also stimulates microglia in the brain to produce cytokines via the central adrenergic system 

4.     A fourth pathway provides a slower immune-to-brain signaling mechanism based on volume transmission.  In this method of immune-to-brain communication, production of IL-1β by the brain first occurs in the choroid plexus and circumventricular organs—brain areas devoid of an intact blood-brain barrier. The cytokines then slowly diffuse throughout the brain by volume transmission, along the way activating microglia, neurons, and neural pathways that induce sickness behavior and inhibit cognition.

Can Flavonoids Reduce Neuroinflammation and Inhibit Cognitive Aging?

Flavonoids are naturally occurring polyphenolic compounds present in plants. The major sources of flavonoids in the human diet include fruits, vegetables, tea, wine, and cocoa.  Significant evidence has emerged to indicate that consuming a diet rich in flavonoids may inhibit or reverse cognitive aging

Flavonoids may improve cognition in the aged through a number of physiological mechanisms, including scavenging of reactive oxygen and nitrogen species and interactions with intracellular signaling pathways. Through these physiological mechanisms, flavonoids also impart an anti-inflammatory effect that may improve cognition. This seems likely for the flavone luteolin, which is most prominent in parsley, celery, and green peppers.

Whereas luteolin inhibits several transcription factors that mediate inflammatory genes (e.g., nuclear factor kappa B [NF-κB]and activator protein 1 [AP-1]), it is a potent activator of nuclear factor erythroid 2-related factor 2 (Nrf2), which induces the expression of genes encoding antioxidant enzymes. A recent study of old healthy mice found improved learning and memory and reduced expression of inflammatory genes in the hippocampus when luteolin was included in the diet. Thus, dietary luteolin may improve cognitive function in the aged by reducing brain microglial cell activity.

Hence, the flavonoid luteolin is a naturally occurring immune modulator that may be effective in reducing inflammatory microglia in the senescent brain.

Conclusion

In light of the recent evidence suggesting microglial cells become dysregulated due to aging and cause neuroinflammation, which can disrupt neural structure and function, it is an interesting prospect to think dietary flavonoids and other bioactives can be used to constrain microglia. But how can flavonoids impart this anti-inflammatory effect? Although in vitro studies clearly indicate that several flavonoids can act directly on microglial cells to restrict the inflammatory response, results from in vivo studies thus far do not prove that dietary flavonoids access the brain to interact with microglia in a meaningful way. This is a complicated question to dissect because flavonoids reduce inflammation in the periphery and microglia seem to act like an “immunostat,” detecting and responding to signals emerging from immune-to-brain signaling pathways. Thus, whether dietary flavonoids enter the brain and impart an anti-inflammatory effect on microglia is an interesting question but one that is more theoretical than practical because what is most important is how the immunostat is adjusted, whether that is via a direct or indirect route. However, because flavonoids are detectable in the brain they most likely affect microglia both directly and by dampening immune-to-brain signaling.

Interesting Natural Substances

In no particular order, these are several very interesting flavonoids/carotenoids.  In the lab, they all do some remarkable things.

In humans, they also do some interesting things; how helpful they might be in autism remains to be seen.

Being “natural” does not mean they are good for you and have no side-effects.

Some of the following are very widely used and so you can establish if there are issues with long term use.  It also makes them accessible.

Quercetin (found in many fruits, numerous interesting effects)

and two Quercetin-related flavonoids:-

Kaempferol (widely used in traditional medicine)

Myricetin (has good and bad effects)

Lycopene  (from tomatoes, potent anti-cancer, does not cross the BBB)

  

Luteolin(in many vegetables, like broccoli) 

Apigenin (from chamomile, stimulates neurogenesis, PAM of GABA_A, block NDMA receptors, antagonist of opioid receptors …)

Tangeretin (from tangerines, does cross the BBB, has potent effects in vitro)

Nobiletin (from tangerines)

Hesperidin (from tangerines)

Naringin (from Grapefruit, contraindicated with many prescription drugs)

Epicatechin/Catechin  (the chocolate/cocoa flavonoids, do cross the BBB, well researched)

Central Hypothyroidism or Low Brain D2 Levels in Autism

I am returning to an old theme of mine, which is my hypothesis that the thyroid releasing hormone (TRH) may be of therapeutic value in autism.  I have been reading up on what some endocrinologists are doing the US and also looking a bit deeper into the underlying biology of the related hormones and thinking about my research sample of one, Monty aged 10 with ASD.   My original hypothesis was argued in an earlier post.

The Peter Hypothesis of TRH-induced Behavioural Homeostatis in Autism

Since none of the TRH researchers care to reply to my emails, I decided to refine and document my hypothesis further and then plan to go and see a child endocrinologist for myself.  In most countries, the doctor does the talking and the patient does the listening, so I know that I need something unusual; I called it “an open minded endocrinologist”.

Peter’s TRH & Central Hypothyroidism Theory

Research has documented which parts of the autistic brain are often damaged.  The Purkinje cell layer and the cerebellum in general has been a focus of my blog; but the hypothalamus, which is very close by, is also known to be different in autistic people.   It has been shown that diminished grey matter exists in a region of the hypothalamus, which synthesizes the behaviorally relevant hormones oxytocin and arginine vasopressin.  My pet hormone “TRH” is also produced in the hypothalamus.  The pituitary gland is a protrusion off the bottom of the hypothalamus at the base of the brain. The pituitary gland is functionally connected to the hypothalamus via a small tube called the pituitary stalk. The pituitary gland secretes nine hormones that regulate homeostatis; one of these is TSH (thyroid stimulating hormone). 

In summary, TRH from the damaged hypothalamus travels down to the pituitary gland where it triggers the release of TSH.  TSH travels a bit further to the thyroid gland where two important hormones, T3 and T4, are produced.

When the levels of T3 and T4 are low a condition called hypothyroidism exists.  T4 is a so-called pro hormone of T3.

I have already noted that when Monty was a young toddler he was tall for his age, about the 90^th percentile; aged 10 his is now about the 25% percentile.  When I started this blog, I saw in the old autism literature there are lots of studies about head circumference in autism.  In summary they found that in autism the head (and by inference the brain) grows very fast in the first couple of years and then by 3 or 4 years of age the brain has prematurely reached adult size.  The brain grew faster than normal and certain parts developed abnormally.  I did not see any research into abnormal development in height.  It would be very easy to study this, since in most countries a child’s height is regularly recorded.

When I recently checked to see what are the effects of hypothyroidism in typical children, I found interesting reading:-

Effects of Hypothyroidism During Infancy. Transient hypothyroidism is common among premature infants. Although temporary, severe cases can cause difficulties in neurologic and mental development.

Infants born with permanent congenital (inborn) hypothyroidism need to receive treatment as soon as possible after birth to prevent mental retardation, stunted growth, and other aspects of abnormal development (a syndrome referred to as cretinism). Untreated infants can lose up to three to five IQ points per month during the first year. An early start of lifelong treatment avoids or minimizes this damage. Even with early treatment, however, mild problems in memory, attention, and mental processing may persist into adolescence and adulthood.

Effects of Childhood-Onset Hypothyroidism. If hypothyroidism develops in children older than 2 years, mental retardation is not a danger, but physical growth may be slowed and new teeth delayed. If treatment is delayed, adult growth could be affected. Even with treatment, some children with severe hypothyroidism may have attention problems and hyperactivity.

Hypothyroidism is usually caused by a failure of the thyroid gland.  TRH is being released to the pituitary, which the produces TSH.  The problem is in the thyroid.  The cure is usually to give T4 in tablet form.  The body is usually able to produce T3 from the T4.

Role of D2 and D3 & Oxidative Stress

Both T3 and T4, are produced in the thyroid gland. The ratio of T3 to T4 released into the blood is 1:20.  Both T3 and T4 then reach the individual body organs, where the prohormone T4 is converted to the biologically active hormone T3. The organ/tissue levels of T3 are regulated locally primarily by the activity of two different selenoenzymes, deiodinases type 2 (D2) and type 3 (D3), although deiodinase type 1 is also involved. In the CNS, approximately 70-80% of T3 originates from intracerebral T4 to T3 conversion, while the plasma contribution amounts to 20-30 %  and D2 is responsible for most of the T3 supply within the brain.

The major source of the biologically active hormone T3 in the brain is the local intra-brain conversion of T4 to T3, while a small fraction comes from circulating T3.

As evidence derived from in vitro studies suggests, in response to oxidative stress D3 increases while D2 decreases (Lamirand et al., 2008; Freitas et al., 2010).  As we know in the autistic brain we have a lot of oxidative stress.

Furthermore, in ASD, the lower intra-brain T3 levels occur in the

Absence of a systemic T3 deficiency (Davis et al., 2008), most likely due to the increased activity of D3.

 

Central Hypothyroidism

There is a supposedly rare condition called Central Hypothyroidism, which occurs when the pituitary gland does not produce enough TSH in response to TRH.  In the research jargon they call it “a blunted response”.  Note that blood levels of TSH, T3 and T4 can be normal in cases of central hypothyroidism.

Research has long ago shown that in autistic children often have a blunted response of TSH to TRH.  Interestingly in many psychiatric conditions, like depression, research also shows a blunted response.

Reduced thyroid-stimulating hormone response to thyrotropin-releasing hormone in autistic boys.

 

The Blunted TSH Responseto TRH — What Does It Tell Us? Biological Monitoring During Psychopharmacological Treatment

Panic, suicide, and agitation: independent correlates of the TSH response to TRH in depression

In the US, psychiatrist have longed prescribed the hormone T3 for depression.  I cannot find much in the way of explanation by psychiatrists of this, other than that some endochronologists do not seem to approve.

In theory if you are low on T3 and T4, the therapy is to give just T4. But as we learned above, if D2 and D3 are misbehaving T3 will not be produced as required.

In the “rare” cases of central hypothyroidism the researchers report being able to correct T4 quite easily but not T3.  So their bodies are not converting enough T4 into T3, because D2 and D3 levels are out of balance.

So the Peter theory has to evolve

In autism there is very likely to be central hypothyroidism, a deficiency of D2 in the brain causes low T3 and I conjecture that there is also a reduced level of TRH being produced in the hypothalamus.  Both the hypothalamus and the pituitary gland are under-responsive.  As a result many hormones are going to be reduced including TRH, TSH, oxytocin, arginine vasopressin and others.

Because TRH also has secondary, only recently understood, behavioral effects, the central hypothyrodism symptoms fits nicely with my earlier TRH theory.

In the US some “holistic” doctors specialized in autism have long been claiming that the majority of kids with ASD are hypothyroid.  They claim that the modern T3 and T4 blood tests are “inaccurate” and that the old TRH stimulation test is more “accurate”.  They then end up prescribing supplementary T3 and T4.  This always looked odd to me; in fact it is yet another case of getting the right answer, but for the wrong reason.

The perfect solution might have been just to give TRH.  You cannot do this because the half-life of TRH is just a few minutes and it needs to be delivered into a vein.   A nasal TRH spray is being developed with funding from the US military.  TRH has mood changing properties and the military has a big problem with suicide.

My idea of using a TRH analog, such as Taltirelin Hydrate, is practical since it has a long half-life and can be taken orally.  It is licensed as a drug, but only in Japan.  It also has a reduced effect on TSH, so you get the benefit of the behavioural properties of TRH rather than just producing more TSH.  This avoids the patient then going hyperthyroid.

A word from the Harvard Medical School

After interest in the 1970s researching autism and the thyroid, not much has been written for decades.  Recently a paper was published by researchers at the Harvard Medical School showing how oxidative stress in the brain, if present, would disrupt thyroid hormone homeostatis.  It has been a long time coming, but it looks like their thinking is spot on.

Environmentally Induced Oxidative Stress and Disruption of Brain Thyroid Hormone Homeostasis in Autism Spectrum Disorders

 

According to this hypothesis, brain region-specific oxidative stress in autism may be associated with increased D3 and decreased D2 activity resulting in a region-specific T3 deficiency in the brain. Future human studies utilizing the CSF of living ASD individuals or postmortem brain tissue of ASD donors will support its validity. Such findings would have several significant implications. They may result in methods of early ASD diagnosis; detection of high brain D3 levels in postmortem human brains may suggest the benefits of measuring the levels of its product (rT3) in the CSF of living patients to assess the risks, monitor the disease progression and efficacy of ongoing treatment. Furthermore, several tissue-specific and TH receptor (TR)-specific thyromimetics have been developed as potential treatment for atherosclerosis, obesity and Type 2 diabetes and might be able to correct local brain TH deficiency without systemic thyrotoxicity (Baxter and Webb, 2009) and may thus be considered as potential therapeutic agents. Finally, confirmation that autism may be associated with increased D3 and decreased D2 activity resulting in a region specific T3 deficiency in the brain could lead to or reinforce dietary treatments, because D2 activity can be modulated not only by selenium but also by xenobiotic compounds (da-Silva

et al., 2007). In conclusion, TH abnormalities in autism warrant a second look.

This paper from Harvard is encouraging and not only concludes that thyroid abnormalities in autism warrant a second look, but suggests ways to raise the level of D2 and correct local brain hypothyroidism

The xenobioyic compound they refer to is the flavonoid kaempferol.

The flavonoid kaempferol looks interesting and there is also much written about its anti-diabetic effects.  This would be a way to raise the amount of D2 and consequently T3 in the brain.  This might be more effective that just supplementing T3.

By the way, just look at all the other things claimed of this flavonoid:-

Numerous preclinical studies have shown kaempferol and some glycosides of kaempferol have a wide range of pharmacological activities, including antioxidant, anti-inflammatory, antimicrobial, anticancer, cardioprotective, neuroprotective, antidiabetic, antiosteoporotic, estrogenic/antiestrogenic, anxiolytic, analgesic, and antiallergic activities.

Kaempferol consumption is also correlated with a reduced lung cancer incidence.

Kaempferol may be a potent prophylactic against NOX-mediated neurodegeneration

If you like natural cures, you will like this paper.  Take a look at page 28.  

A Review on the Dietary Flavonoid Kaempferol

As with other flavonoids, there is low bioavailability – they are absorbed by the body in tiny quantities.  And they are VERY expensive.

 

Conclusion

I wish the Harvard Medical School would follow up fast on its own research, so I do not have to rely on the internet writings of “holistic” doctors.  As the Harvard paper concluded “TH abnormalities in autism warrant a second look”.

Oral T3 clearly does enter the brain in marked quantities, otherwise I suppose US psychiatrists would not keep using it with their depressed patients.  Research shows that most T3 in the brain originates from T4 converted there by D2.  This implies to me that an alternative therapy would be to give something like kaempferol to raise the level of D2.  The problem, as with other useful flavonoids, like Quercetin and Rutin, is low bioavailability – they are absorbed by the body in tiny quantities.  Kaempferol appears to have the basis of being a wonder drug, but let's wait 20 years to see.

In the meantime, I will review all this with my sought for “open minded endochronologist”.  All I can measure is TSH, T3 and T4 in the blood, I cannot even guess at T3 or D2 in the brain.  The old TRH stimulation test involves lots of needles and that is something I have to try and avoid.  Autistic kids don’t sit still for needles.