Ketones and Autism Part 6 - Capric Acid (C10) for Mitochondrial Disease, in Particular Complex 1, plus more on Metformin

Capric Acid (C10) is so named because it smells like a goat (Goat in Latin = Caper)

Photographer: Armin Kübelbeck, CC-BY-SA, Wikimedia Commons

Rather than Goaty acid, C10 is called Capric acid, or indeed Decanoic acid (after its 10 carbon atoms). Today’s post is indirectly again about ketones, because if you eat a Ketogenic Diet (KD) you are likely to consume a fair amount of Capric acid (C10).

I have written a lot in this blog about mitochondria, even though I do not think my son has mitochondrial dysfunction. Clearly many people with autism do have a lack of one or more of the critical mitochondrial enzyme complexes that allow glucose to be converted to ATP (usable energy), by the clever process OXPHOS (Oxidative phosphorylation).

The “rate limiting” enzyme is usually Complex 1, meaning that is the one it is most important not to be short of.

Another favourite, but obscure, subject of this blog is PPAR gamma.

Peroxisome proliferator-activated receptors (PPARs) are a group of proteins that function as transcription factors regulating the expression of certain genes. Transcription factors are particularly important because they trigger numerous effects.

PPAR gamma plays a key role in fat storage and glucose metabolism, but has other functions. 

Activation of PPAR-gamma by Capric acid (C10) has been shown to increase the number of mitochondria, increase the mitochondrial enzyme citrate synthase, increase complex I activity in mitochondria, and increase activity of the antioxidant enzyme catalase. 

So, if you have autism and impaired mitochondrial function, C10 may well give a benefit because it can increase the peak power available to your brain.

The ketogenic diet component decanoic acid increases mitochondrial citrate synthase and complex I activity in neuronal cells

The Ketogenic diet (KD) is an effective treatment with regards to treating pharmaco-resistant epilepsy. However, there are difficulties around compliance and tolerability. Consequently, there is a need for refined/simpler formulations that could replicate the efficacy of the KD. One of the proposed hypotheses is that the KD increases cellular mitochondrial content which results in elevation of the seizure threshold. Here, we have focussed on the medium-chain triglyceride form of the diet and the observation that plasma octanoic acid (C8) and decanoic acid (C10) levels are elevated in patients on the medium-chain triglyceride KD. Using a neuronal cell line (SH-SY5Y), we demonstrated that 250-μM C10, but not C8, caused, over a 6-day period, a marked increase in the mitochondrial enzyme, citrate synthase along with complex I activity and catalase activity. Increased mitochondrial number was also indicated by electron microscopy. C10 is a reported peroxisome proliferator activator receptor γ agonist, and the use of a peroxisome proliferator activator receptor γ antagonist was shown to prevent the C10-mediated increase in mitochondrial content and catalase. C10 may mimic the mitochondrial proliferation associated with the KD and raises the possibility that formulations based on this fatty acid could replace a more complex diet. We propose that decanoic acid (C10) results in increased mitochondrial number. Our data suggest that this may occur via the activation of the PPARγ receptor and its target genes involved in mitochondrial biogenesis. This finding could be of significant benefit to epilepsy patients who are currently on a strict ketogenic diet. Evidence that C10 on its own can modulate mitochondrial number raises the possibility that a simplified and less stringent C10-based diet could be developed.

Capric Acid (C10) as a PPARγ agonist

As shown in the above study the mechanism by which C10 benefits the mitochondria is via PPARγ agonism.

Here is another study confirming that C10 is indeed a PPARγ agonist.

Identification and Mechanism of 10-Carbon Fatty Acid as Modulating Ligand of Peroxisome Proliferator-activated Receptors

Background: Mechanism of action of medium chain fatty acid remains unknown.

Results: Our results show that decanoic acid (C10) binds and activates PPARγ.

Conclusion: Decanoic acid acts as a modulator of PPARγ and reduces blood glucose levels with no weight gain.

Significance: This study could lead to design of better type 2 diabetes drugs.

Other PPARγ agonists

PPARγ agonists have been covered previously in this blog and we know that glitazones, a class of drugs for diabetes, do improve some types of autism. Glitazones are PPARγ agonists.

Metformin, a very widely used drug for type 2 diabetes, works differently to Glitazones, but I did suggest a while back it should help some types of autism. Last year it was indeed found to be beneficial in Fragile X.

Diabetes drug may help symptoms of autism-associated condition

 "Basically, it's something like a wonder drug," Sonenberg said.

The study suggests that metformin might also be used to treat other autism spectrum disorders, said Ilse Gantois, a research associate in Sonenberg's lab at McGill.

"We mostly looked at the autistic form of behaviour in the Fragile X mouse model," explained Gantois, who is co-lead author with McGill researchers Arkady Khoutorsky and Jelena Popic. "We want to start testing other mouse models to see if the drug could also have benefits for other types of autism."

Metformin is very cheap and has been used in humans for 60 years. It is another example of re-purposing a drug from Grandpa’s medicine cabinet to treat Grandson’s autism. 

Metformin has been trialled to combat obesity in idiopathic autism caused by antipsychotics. It did help with weight gain, but no comments were made about behavioural improvements, but then those studied were on antipsychotic drugs, which might mask such effects. 

Glitazone-type drugs appear more problematic than Metformin.

There are natural PPAR gamma agonists and they are often used to lower cholesterol, lower blood sugar and improve insulin sensitivity.

Sytrinol, a product containing flavanols tangeretin and nobiletin does indeed have a positive effect on some people’s autism, but for most people (but not all) the effect is lost after a few days.

Our doctor reader Maja, did suggest combining it with a PPARα agonist to see if the effect might be maintained.

This combination has indeed been researched for type 2 diabetes.               

The effect of dual PPAR alpha/gamma stimulation with combination of rosiglitazone and fenofibrate on metabolic parameters in type 2 diabetic patients.

There actually is another natural substance that is an agonist of both PPARγ and PPARα, Berberine, the alkaloid long used in Chinese medicine.

In the research it is suggested that “BRB localizes in mitochondria, inhibits respiratory electron chain and activates AMPK”, which is not what you would want. But this may not be correct.

People who like supplements might want to follow up on Berberine.

Berberine is used by many people with diabetes and a few with autism, for all kinds of reasons, from mercury to GI problems.

Berberine is a potent agonist of peroxisome proliferator activated receptor alpha.

Although berberine has hypolipidemic effects with a high affinity to nuclear proteins, the underlying molecular mechanism for this effect remains unclear. Here, we determine whether berberine is an agonist of peroxisome proliferator-activated receptor alpha (PPARalpha), with a lipid-lowering effect. The cell-based reporter gene analysis showed that berberine selectively activates PPARalpha (EC50 =0.58 mM, Emax =102.4). The radioligand binding assay shows that berberine binds directly to the ligand-binding domain of PPARalpha (Ki=0.73 mM) with similar affinity to fenofibrate. The mRNA and protein levels of CPT-Ialpha gene from HepG2 cells and hyperlipidemic rat liver are remarkably up-regulated by berberine, and this effect can be blocked by MK886, a non-competitive antagonist of PPARalpha. A comparison assay in which berberine and fenofibrate were used to treat hyperlipidaemic rats for three months shows that these drugs produce similar lipid-lowering effects, except that berberine increases high-density lipoprotein cholesterol more effectively than fenofibrate. These findings provide the first evidence that berberine is a potent agonist of PPARalpha and seems to be superior to fenofibrate for treating hyperlipidemia.

Berberine activates peroxisome proliferator-activated receptor gamma to increase atherosclerotic plaque stability in Apoe^-/- mice with hyperhomocysteinemia.

                                                                                                                                     

Sources of Capric Acid (C10)

Goat milk is a good source of capric acid.

Capric acid is 8-10% of coconut oil and 4% of palm kernel oil

Capric acid is a large component (about 40%) of the less expensive MCT oil supplements.

http://cdn.intechopen.com/pdfs/39464/InTech-The_effect_of_fatty_acids_in_goat_milk_on_health.pdf

1.2. Fatty acid composition in goat milk fat Average goat milk fat differs in contents of its fatty acids significantly from average cow milk fat, being much higher in butyric (C4:0), caproic (C6:0), caprylic (C8:0), capric (C10:0), lauric (C12:0), myristic (C14:0), palmitic (C16:0), linoleic (C18:2), but lower in stearic (C18:0), and oleic acid (C18:1) (Table 1). Three of the medium chain fatty acids (caproic, caprylic, and capric) have actually been named after goats, due to their predominance in goat milk. They contribute to 15% of the total fatty acid content in goat milk in comparison to 5% in cow milk (Haenlein, 1993). The presence of relatively high levels of medium chain fatty acids (C6:0 to C10:0) in goat milk fat could be responsible for its inferior flavour (Skjevdal, 1979). 

             

Conclusion

If someone responds well to coconut oil or cheaper MCT oil the reason may have more to do with PPAR gamma and improved mitochondrial function than anything to do with ketones and what they do.

Cheaper MCT oils are mainly a mixture of C8 and C10. To maximize the production of the ketone BHB you really want just C8, but if what you really need is a PPAR gamma agonist, to perk up your mitochondria, it is the C10 you need.

You may indeed benefit from both ketones and agonizing PPAR gamma, in which case you either follow the Ketogenic Diet, or supplement BHB, C8 and C10.

I think this explains why some people with autism reportedly respond well to teaspoon-sized doses of cheaper MCT oil or small amounts of coconut oil.

If you have Complex 1 mitochondrial dysfunction then a dose of Capric acid (C10) is likely to help.

Berberine may, or may not be, as effective as C10. I doubt we will ever know. I think C10 is the better option. 

I wonder when the Canadian researchers will publish their results showing whether Metformin is beneficial beyond Fragile X syndrome. They do not really know why it helps, but that is a repeating theme in medicine.  It is a cheap safe drug, so it would be a pity to waste time finding out if it could be repurposed for some autism.

Oxaloacetate and Pepping up Bioenergetic Fluxes in Autism and other Neurological Diseases

BHI as a dynamic measure of the response of the body to stress

In this scheme, healthy subjects have a high BHI with a high bioenergetic reserve capacity, high ATP-linked respiration (AL) and low proton leak (PL). The population of mitochondria is maintained by regenerative biogenesis. During normal metabolism, a sub-healthy mitochondrial population, still capable of meeting the energetic demand of the cell, accumulates functional defects, which can be repaired or turned over by mitophagy. Chronic metabolic stress induces damage in the mitochondrial respiratory machinery by progressively decreasing mitochondrial function and this manifests as low ATP-linked respiration, low reserve capacity and high non-mitochondrial (e.g. ROS generation) respiration. These bioenergetically inefficient damaged mitochondria exhibit increased proton leak and require higher levels of ATP for maintaining organelle integrity, which increases the basal oxygen consumption. In addition, chronic metabolic stress also promotes mitochondrial superoxide generation leading to increased oxidative stress, which can amplify mitochondrial damage, the population of unhealthy mitochondria and basal cellular energy requirements. The persistence of unhealthy mitochondria damages the mtDNA, which impairs the integrity of the biogenesis programme, leading to a progressive deterioration in bioenergetic function, which we propose can be identified by changes in different parameters of the bioenergetics profile and decreasing BHI.

Source:  The Bioenergetic Health Index: a new concept in mitochondrial translational research

Bioenergetic is today’s new buzz word; it is again all about getting maximum power output (ATP) from your mitochondria, which we looked at from a different perspective in a recent post.

Autism, Power Outages and the Starving Brain?

A simple lack of ATP inside the brain seems to be a feature of many kinds of neurological problem. 

Oxaloacetate (OA or OAA) is another interesting potential treatment for a wide range of neurological disorders from Alzheimer’s and ALS to Huntington’s and Parkinson’s. There are no effective treatments for any of these conditions and little has changed in decades.

OAA, at high doses, and in animal studies, does have some very interesting effects, but they are perhaps too wide ranging, because some may be helpful and others not. OAA is interesting but no panacea.

OAA is sold as a supplement in low doses. It changes so many things, I think it is not surprising that some people find it beneficial, whether it is for Bipolar, ADHD or something else.

I think at higher doses, where there is a measurable impact above and beyond the OAA you have naturally in your blood, there might be some benefit as a treatment for mitochondrial disease. That would mean most regressive autism and some Childhood Disintegrative Disorder (CDD).

So we can consider OAA as another potential therapy for bioenergetic dysfunction. We have come across many potential therapies already in this blog.

Here is a schematic summary of what OAA does.

OAA effects and inter-effect relationships. OAA, a bioenergetic intermediate, affects bioenergetic flux. This produces a number of molecular changes. CREB phosphorylation and CREB activity increase, which in turn promotes the expression of PGC1 family member genes. AMPK and p38 MAP phosphorylation increase, and these activated kinases enhance PGC1α co-activator function. PGC1-induced co-activation of the NRF1 transcription factor stimulates COX4I1 production, while PGC1-induced co-activation of the ERRα transcription factor stimulates VEGF gene expression (61). OAA-induced flux changes also stimulate the pro-growth insulin signaling pathway and reduce inflammation. The pro-growth effects of increased insulin pathway signaling and increased VEGF, in conjunction with a more favorable bioenergetic status and less inflammation, cooperatively stimulate hippocampal neurogenesis.

You may recall from earlier posts that PGC-1α is the master regulator of mitochondrial biogenesis. 

The PGC-1α protein also appears to play a role in controlling blood pressure, regulating cellular cholesterol homoeostasis, and the development of obesity.

The PGC-1 α protein interacts with the nuclear receptor PPARγ. PPARγ has been covered extensively in this blog; agonists of PPARγ do seem to be therapeutic in some autism. Many drugs that are used to treat Type 2 diabetes work because they are PPARγ agonists.

It is not a surprise that Oxaloacetate (OAA) lowers your blood sugar. 

Oxaloacetate activates brain mitochondrial biogenesis, enhances the insulin pathway, reduces inflammation and stimulates neurogenesis. 

Tolerability and pharmacokinetics of oxaloacetate 100 mg capsules in Alzheimer's subjects

Bioenergetics and bioenergetic-related functions are altered in Alzheimer's disease (AD) subjects. These alterations represent therapeutic targets and provide an underlying rationale for modifying brain bioenergetics in AD-affected persons. Preclinical studies in cultured cells and mice found that administering oxaloacetate (OAA), a Krebs cycle and gluconeogenesis intermediate, enhanced bioenergetic fluxes and upregulated some brain bioenergetic infrastructure-related parameters. We therefore conducted a study to provide initial data on the tolerability and pharmacokinetics of OAA in AD subjects. Six AD subjects received OAA 100 mg capsules twice a day for one month. The intervention was well-tolerated. Blood level measurements following ingestion of a 100 mg OAA capsule showed modest increases in OAA concentrations, but pharmacokinetic analyses were complicated by relatively high amounts of endogenous OAA. We conclude that OAA 100 mg capsules twice per day for one month are safe in AD subjects but do not result in a consistent and clear increase in the OAA blood level, thus necessitating future clinical studies to evaluate higher doses.

In addition to being proposed for the treatment of AD and diabetes, recent preclinical research has also identified OAA as a potential therapeutic agent for stroke, traumatic brain injury, amyotrophic lateral sclerosis, and glioma [15], [16], [17], [18]. The clinical safety data we now report should prove relevant to efforts intending to translate results from these preclinical studies to the clinical arena. Our study also informs our attempts to develop OAA as a treatment for AD. Overall, we conclude that although OAA 100 mg capsules twice per day for one month are safe in AD subjects, because a consistent and clear increase in the OAA plasma level was not observed future clinical studies need to evaluate higher doses.

A Pilot Study of Oxaloacetate in Subjects With Treated PD

Experimental: Oxaloacetate (OAA) active capsule containing 100 mg OAA and 100 mg ascorbate, taken daily  

Trial of Oxaloacetate in Alzheimer's Disease (TOAD) (TOAD)

Experimental: Part 2 - Oxaloacetate (OAA)2 gram/day 
Participants take 2 grams of OAA per day for period of 4 weeks

Oxaloacetate Supplementation for Emotional PMS (OAA4PMS)

Participants take 2 capsules Jubilance 100 mg Oxaloacetate/150 mg Ascorbic Acid blend per day

Oxaloacetate is an energy metabolite found in every cell of the human body. It holds a key place in the Krebs Cycle within the mitochondria, providing energy to the cells. It is also a critical early metabolite in gluconeogenesis, which provides glucose for the heart and brain during times of low glucose. It is critical to human metabolism, proper cellular function and it is central to energy production and use in the body.

Oxaloacetate may affect Emotional PMS through multiple mechanisms. During PMS, there is a large increase in glucose utilization in the cerebellum of the brain in women who are affected with emotional mood swings. Oxaloacetate supplementation has been shown to support proper glucose levels in the body. Having an excess of oxaloacetate allows gluconeogenesis take place upon demand, thereby fueling the brain, and perhaps meeting cerebellum glucose need.

In addition to oxaloacetate's ability to support proper glucose regulation, oxaloacetate affects two chemicals in the brain, GABA and glutamate. Altering the GABA/Glutamate ratio can affect mood. Oxaloacetate supplementation can reduce glutamate levels in the brain via a process called "Glutamate Scavenging". In addition, oxaloacetate supplementation was shown to increase GABA levels in animal models. By both lowering glutamate and increasing GABA, the GABA/Glutamate ratio is affected, which may also help women with Emotional PMS.

This study will investigate oxaloacetate's effect on Emotional PMS using patient completed surveys to measure depression, anxiety, perceived stress, and aggression, and statistically compare these results against placebo (rice flour) and baseline measurements.

An interesting old paper from 1968 was recently highlighted to me by a friend, it  shows that sodium oxaloacetate is particularly effective in treating type-1 diabetes.  In type-2 diabetes the effect range from none/minor in most  to a profound effect in a minority.

The meaning of “treating” was reducing blood sugar levels.

This study was the result of identifying the active substance in the plant euonymus alatus sieb, which has known blood sugar lowering effects.

http://tnipc.org/invasive-plants/plant-details/?id=48

Introduced from northeast Asia in the 1860s. Widely planted as an ornamental and for highway beautification due to its reliable and very showy fall foliage coloration. Numerous cultivars are available.

Other states where invasive: CT, DE, IN, KY, MA, MD, MO, NH, NJ, OH, PA, RI, VA, WI, WV. Federal or state listed as noxious weed, prohibited, invasive or banned: CT, MA.

Here is the interesting Japanese paper from 1968: 

Studies on Anti-diabetic Effect of Sodium Oxalcacetate

There are more recent studies on the Euonymus alatus plant:

Euonymus alatus: A Review on Its Phytochemistry and Antidiabetic Activity

Euonymus alatus (E. alatus) is a medicinal plant used in some Asian countries for treating various conditions including cancer, hyperglycemia, and diabetic complications. This review outlines the phytochemistry and bioactivities of E. alatus related to antidiabetic actions. More than 100 chemical constituents have been isolated and identified from E. alatus, including flavonoids, terpenoids, steroids, lignans, cardenolides, phenolic acids, and alkaloids. Studies in vitro and in vivo have demonstrated the hypoglycemic activity of E. alatus extracts and its certain constituents. The hypoglycemic activity of E. alatus may be related to regulation of insulin signaling and insulin sensitivity, involving PPARγ and aldose reductase pathways. Further studies on E. alatus and its bioactive compounds may help to develop new agents for treating diabetes and diabetic complications.

A total of 26 flavonoids have been isolated and identified from E. alatus. The main structure types include flavonoid, flavanone, and flavonol. The aglycones of flavonoid glycosides isolated from E. alatus include quercetin, kaempferol, naringenin, aromadendrene, and dihydroquercetin. The flavonoids are mainly distributed in the leaves and wings of E. alatus

There is no mention of oxaloacetic acid.

The active components in protecting experimental diabetic nephropathy as mentioned above have also been suggested to be concentrated in ethyl acetate and n-butanol fractions [36, 40], though the nature of these compounds is still not identified. 

Alleviating effects of active fraction of Euonymus alatus abundant in flavonoids on diabetic mice.

Euonymus alatus (E. alatus) has been used as a folk medicine for diabetes in China for more than one thousand years. In order to identify major active components, effects of different fractions of E. alatus on the plasma glucose levels were investigated in normal mice and alloxan-induced diabetic mice. Our results show that ethyl acetate fraction (EtOAc Fr.) displayed significant effects on reducing plasma glucose. In oral glucose tolerance, EtOAc Fr. at 17.2 mg/kg could significantly decrease the blood glucose of both normal mice and diabetic mice. After 4 weeks administration of the EtOAc Fr, when compared with the diabetic control, there were significant difference in biochemical parameters, such as glycosylated serum protein, superoxide dismutase and malondial dehyde, triglyceride, and total cholesterol, between alloxan-induced diabetic mice and the control group. Additional histopathological studies of pancreatic islets also showed EtOAc Fr. has beneficial effects on diabetic mice. Chemical analysis with three-dimensional HPLC demonstrated that the major components from EtOAc Fr were flavonoids and phenolic acids, which had anti-oxidative effects on scavenging DPPH-radical in vitro. All these experimental results suggest that EtOAc Fr. is an active fraction of E. alatus and can prevent the progress of diabetes. The mechanism of E. alatus for glucose control may be by stimulating insulin release, improving glucose uptake and improving oxidative-stress.

Oxaloacetic acid

You already have Oxaloacetic acid in your body, you make it.

Oxaloacetic acid (also known as oxalacetic acid) is a metabolic intermediate in many processes that occur in animals. It takes part in the gluconeogenesis, urea cycle, glyoxylate cycle, amino acid synthesis, fatty acid synthesis and citric acid cycle. Oxaloacetate is also a potent inhibitor of Complex II.

Conclusion

This post was prompted by our reader LatteGirl, who was asking about the supplement BenaGene and ketones. BenaGene contains 100mg of OAA and the company behind it is the sponsor of some the current OAA clinical trials.

The BenaGene supplement is sold by some companies that sell ketone products, but I do not really see big connection between OAA and ketones.   

If you can materially increase the plasma level of OAA, you really would expect numerous changes to occur.

Depending on what might be wrong with you, OAA might provide a net benefit, but it all looks very hit and miss. 

Treatment of all neurological disorders from ALS, Alzheimer’s to depression currently is remarkably hit and miss. Most serious disorders have only very partially effective treatments, but they do get FDA approval nonetheless.

The OAA research suggests its effect is from “altered bioenergetic fluxes”. You might be wondering what this actually means, since it sounds like pseudoscientific mumbo jumbo. What this really means is that for one reason or another there is a shortfall in energy (ATP) to power your cells.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3888119/

“Perturbed bioenergetic function, and especially mitochondrial dysfunction, is observed in brains and peripheral tissues of subjects with Alzheimer's disease (AD) and mild cognitive impairment (MCI) (1,2), a clinical syndrome that frequently represents a transition between normal cognition and AD dementia (3). Neurons are vulnerable to mitochondrial dysfunction due to their high energy demands and dependence on respiration to generate ATP (4). Mitochondrial dysfunction may, therefore, drive or mediate various AD pathologies.”

Impaired energy (ATP) production can be caused by a deficiency in one of the mitochondrial enzyme complexes (often complex 1), but it could be caused by too few mitochondria (each cell needs many) or it could be caused by a lack of fuel (glucose or ketones), or oxygen.

Glucose crosses the blood brain barrier via a transporter called GLUT1.

GLUT1 deficiency leads to epilepsy, cognitive impairment and a small head (microcephaly). It can be treated by adopting the ketogenic diet, where ketones replace glucose as the fuel for your brain and body.

Oxygen freely crosses the blood brain barrier, but sometimes there is not enough of it. To increase the amount of oxygen that is carried in the blood, mountaineers and the military sometimes use the drug Diamox, which changes the pH of your blood, among other effects.

The brain's blood supply is via microvasculature/microvessels. This does seem to be impaired in autism, according to the research, resulting in unstable blood flow to the brain. 

Thyroid hormones are generally seen as regulating your basal/resting metabolic rate, so rather like your idle on your car, when you do not press the accelerator/gas pedal.  If the idle rate is too low your car will stall in traffic.

Thyroid hormone has many other effects and these are very important in the brain, particularly during development. A lack of the T3 hormone will lead to a physically different brain, whereas in adulthood it just causes impaired function which is reversible.

Thyroid hormones T3 and T4 can cross the blood brain barrier. The prohormone T4 is converted into the active hormone T3 within the brain. Some research suggests that T4 may have a direct role in the brain, rather than simply being a source of T3.

Thyroid receptors in the brain

TRα1 encompasses 70–80% of all TR expression in the adult vertebrate brain and TRα1 is present in nearly all neurons

It appears that windows in brain development may exist where T4 itself may act on TRα1.

Thyroid Hormone (TH) endocrinology in the CNS is tightly regulated at multiple tiers. Negative feedback loops in the hypothalamus and the pituitary control T3 and T4 output by the thyroid gland itself. Further, multiple phenomenon functions together to modulate the transport of circulating TH through the BBB, and multiple transporters act together to directly alter TH availability in the CNS itself. Additionally, conversion of intracellular T₄ into T₃ by deiodinase 2, inactivation of both T₃ and T₄ by deiodinase 3, and, the ability of different TR isoforms and different coregulators to respond directly to T₄ versus T₃ further regulate the CNS response to TH. 

https://www.ncbi.nlm.nih.gov/books/NBK285549/

The thyroid hormone receptor subtypes TRα and TRβ are expressed throughout the brain from early development, and mediate overlapping actions on gene expression. However there are also TR-subtype specific actions. Dio3 for example is induced by T3 specifically through TRα1. In vivo T3 regulates gene expression during development from fetal stages, and in adult animals. A large number of genes are under direct and indirect regulation by thyroid hormone. In neural cells T3 may control around 5% of all expressed genes, and as much as one third of them may be regulated directly at the transcriptional level. Thyroid hormone deficiency during fetal and postnatal development may cause retarded brain maturation, intellectual deficits and in some cases neurological impairment. Thyroid hormone deficiency to the brain during development is caused by iodine deficiency, congenital hypothyroidism, and maternal hypothyroidism and hypothyroxinemia. The syndromes of Resistance to Thyroid Hormones due to receptor mutations, especially TRα, cause variable affectation of brain function. Mutations in the monocarboxylate transporter 8 cause a severe retardation of development and neurological impairment, likely due to deficient T4 and T3 transport to the brain.   

Thyroid hormones are essential for brain maturation, and for brain function throughout life. In adults, thyroid diseases can lead to various clinical manifestations (1,2). For example, hypothyroidism causes lethargy, hyporeflexia and poor motor coordination. Subclinical hypothyroidism is often associated with memory impairment. Hypothyroidism is also associated to bipolar affective disorders, depression, or loss of cognitive functions, especially in the elderly (3). Hyperthyroidism causes anxiety, irritability, and hyperreflexia. Both, hypothyroidism or hyperthyroidism can lead to mood disorders, dementia, confusion, and personality changes. Most of these disorders are usually reversible with proper treatment, indicating that thyroid hormone alterations of adult onset do not leave permanent structural defects.

The actions of thyroid hormone during development are different, in the sense that they are required to perform certain actions during specific time windows. Thyroid hormone deficiency, even of short duration may lead to irreversible brain damage, the consequences of which depend not only on the severity, but also on the specific timing of onset and duration of the deficiency (4-8).

Hypothyroidism causes delayed and poor deposition of myelin

Pep up your Bioenergetic Fluxes

Within this blog we have encountered a wide range of methods that might help put correct a deficiency in power available to the brain.

·      Improve brain microvasculature function (Agmatine)

·      Ensure central basal metabolic rate is high enough (T3 hormone)

·      Increase D2 (lower oxidative stress, kaempferol) if centrally hypothyroid

·      Increase number of mitochondria (activate PGC1alpha)

·      Ensure adequate mitochondrial enzyme complexes for OXPHOS

·      Ensure adequate glucose transport via GLUT1

While I still feel Bioenergetic Fluxes sounds like something very quack-like, it is the valid terminology and it does look important to many neurological conditions.

In Monty, aged 14 with ASD, Agmatine has worked wonders, in terms of being far more energetic. I assume the effect is via increasing eNOS (endothelial nitric oxide synthase) and this has improved blood supply. We saw that blood flow through microvasculature/microvessels is impaired in autism.  We also saw that in mouse model of Alzheimer’s, Agmatine has a similar positive effect; this also seems to apply in at least some humans with Alzheimer’s.  

Diabetes

We can certainly add Oxaloacetate to the long list of substances we have come across in this blog that may well be therapeutic in diabetes. In the case of Oxaloacetate, it is type-1 that seems to uniformly benefit, whereas in type-2 diabetes some benefit and some do not.

It is amazing that in type-1 diabetes, only insulin is routinely prescribed, when so many things can increase insulin sensitivity and reduce the severe complications of this type of diabetes.

In the case of type-2 diabetes, you can halt its progression and, for the really committed, we saw how you can reverse it.

If a common, life-threatening, condition like diabetes is not fully treated, no wonder nobody bothers to treat an amorphous condition like autism.

Autism, Power Outages and the Starving Brain?

There are certain Critical Periods in the development of the human brain and these are the most vulnerable times to any genetic or environmental insult.  Critical Periods (CPs) will be the subject of post appearing shortly.

Another power outage waiting to happen

 Have you wondered why autism secondary to mitochondrial disease (regressive autism) almost always seem to occur before five years of age, and usually much earlier?  Why does it not happen later? Why is it's onset often preceded by a viral infection?

I think you can consider much of this in terms of the brain running out of energy. Humans have evolved to require a huge amount of energy to power their developing brains, a massive 40% of the body’s energy is required by the brain in early childhood.  If your overload a power grid it will end in a blackout.

We know many people with autism have a tendency towards mitochondrial dysfunction, they lack some key enzyme complexes. This means that the process of OXPHOS (Oxidative phosphorylation), by which the body converts glucose to usable energy (ATP), is partially disabled. 

Mitochondrial Disease and Autism

We saw in earlier posts how the supply of glucose and oxygen to the brain can be impaired in autism because there is unstable blood flow.

Unstable Blood Flow in Autistic Brains

It is just like in your house, all your electrical appliances might mean you need a 25KW supply, because you do not use them all at the same time. Just to be on the safe side you might have a 40KW limit. What if the power company will only give you a 20 KW connection? If you turn on the clothes drier, the oven, the air conditioning and some other things all of a sudden you blow the main fuse and perhaps damage the hard drive of your old computer.

So, in the power-hungry brain of a three-year-old, you add a viral infection and all of a sudden you exceed the available power supply from the mitochondria, that have soldered on for 3years with impaired supply of complex 1 and imperfect cerebral blood flow. By the sixth year of life, the peak power requirement from the brain would have fallen to within the safe limit of the mitochondria and its impaired supply of complex 1.  Instead of blowing the fuse, which is easy to reset, you have blown some neuronal circuitry, which is not so easy to repair.    

Too Many Synapses?

We know that it is the synapses in the brain that are the big energy users and we also know that in most autism there are too many synapses. So, in that group of autism there is an even bigger potential energy demand.

Note that in Alzheimer’s type dementia (AD in the above chart) you see a severe loss of synapses/spines as atrophy takes place. This occurs at the same time as a loss of insulin sensitivity occurs (type 3 diabetes). Perhaps the AD brain is also starved of energy, it does seem to respond to ketosis (ketones replacing glucose as the fuel) and it responds to Agmatine (increasing blood flow via eNOS).

We also know that adolescent synaptic pruning is dysfunctional in autism and we even know why. Interestingly by modifying GABA_A function with bumetanide we may indeed allow the brain to eliminate more synapses (a good thing), so possibly an unexpected benefit from Ben Ari’s original idea.

https://www.sciencedaily.com/releases/2016/05/160502161118.htm

"Working with a mouse model we have shown that, at puberty, there is an increase in inhibitory GABA receptors, which are targets for brain chemicals that quiet down nerve cells. We now report that these GABA receptors trigger synaptic pruning at puberty in the mouse hippocampus, a brain area involved in learning and memory." The report, published by eLife, "Synaptic pruning in the female hippocampus is triggered at puberty by extrasynaptic GABAA receptors on dendritic spines."            

These findings may suggest new treatments targeting GABA receptors for "normalizing" synaptic pruning in diseases such as autism and schizophrenia, where synaptic pruning is abnormal. Research has suggested that children with autism may have an over-abundance of synapses in some parts of the brain.

Synaptic pruning in the female hippocampus is triggered at puberty by extrasynaptic GABAA receptors on dendritic spines

Adolescent synaptic pruning is thought to enable optimal cognition because it is disrupted in certain neuropathologies, yet the initiator of this process is unknown. One factor not yet considered is the α4βδ GABA_A receptor (GABAR), an extrasynaptic inhibitory receptor which first emerges on dendritic spines at puberty in female mice. Here we show that α4βδ GABARs trigger adolescent pruning. Spine density of CA1 hippocampal pyramidal cells decreased by half post-pubertally in female wild-type but not α4 KO mice. This effect was associated with decreased expression of kalirin-7 (Kal7), a spine protein which controls actin cytoskeleton remodeling. Kal7 decreased at puberty as a result of reduced NMDAR activation due to α4βδ-mediated inhibition. In the absence of this inhibition, Kal7 expression was unchanged at puberty. In the unpruned condition, spatial re-learning was impaired. These data suggest that pubertal pruning requires α4βδ GABARs. In their absence, pruning is prevented and cognition is not optimal.

Strange Patterns of Growth

Longitudinal studies are when researchers collect the same data over long period of years. Most autism research is just based on a single snapshot in time.

One observation of mine is that some people with strictly defined autism (SDA) are born at the 90+ percentile for height, but then fall back to something like the 20 percentile. Body growth has dramatically slowed. Was this because energy has been diverted to the overgrowing brain? 

A Long Childhood Feeds the Hungry Human Brain
Study of brain scans explains why children grow slowly and childhood lasts so long 

A five-year old’s brain is an energy monster. It uses twice as much glucose (the energy that fuels the brain) as that of a full-grown adult, a new study led by Northwestern University anthropologists has found.

It was previously believed that the brain’s resource burden on the body was largest at birth, when the size of the brain relative to the body is greatest. The researchers found instead that the brain maxes out its glucose use at age 5. At age 4 the brain consumes glucose at a rate comparable to 66 percent of the body’s resting metabolic rate (or more than 40 percent of the body’s total energy expenditure). 

“The mid-childhood peak in brain costs has to do with the fact that synapses, connections in the brain, max out at this age, when we learn so many of the things we need to know to be successful humans,” Kuzawa said.

“At its peak in childhood, the brain burns through two-thirds of the calories the entire body uses at rest, much more than other primate species,” said William Leonard, co-author of the study. “To compensate for these heavy energy demands of our big brains, children grow more slowly and are less physically active during this age range. Our findings strongly suggest that humans evolved to grow slowly during this time in order to free up fuel for our expensive, busy childhood brains.” 

Full paper: -

Metabolic costs and evolutionary implications of human brain development

The high energetic costs of human brain development have been hypothesized to explain distinctive human traits, including exceptionally slow and protracted preadult growth. Although widely assumed to constrain life-history evolution, the metabolic requirements of the growing human brain are unknown. We combined previously collected PET and MRI data to calculate the human brain’s glucose use from birth to adulthood, which we compare with body growth rate. We evaluate the strength of brain–body metabolic trade-offs using the ratios of brain glucose uptake to the body’s resting metabolic rate (RMR) and daily energy requirements (DER) expressed in glucose-gram equivalents (glucose_rmr% and glucose_der%). We find that glucose_rmr% and glucose_der% do not peak at birth (52.5% and 59.8% of RMR, or 35.4% and 38.7% of DER, for males and females, respectively), when relative brain size is largest, but rather in childhood (66.3% and 65.0% of RMR and 43.3% and 43.8% of DER). Body-weight growth (dw/dt) and both glucose_rmr% and glucose_der% are strongly, inversely related: soon after birth, increases in brain glucose demand are accompanied by proportionate decreases in dw/dt. Ages of peak brain glucose demand and lowest dw/dt co-occur and subsequent developmental declines in brain metabolism are matched by proportionate increases in dw/dt until puberty. The finding that human brain glucose demands peak during childhood, and evidence that brain metabolism and body growth rate covary inversely across development, support the hypothesis that the high costs of human brain development require compensatory slowing of body growth rate. 

To quantify the metabolic costs of the human brain, in this study we used a unique, previously collected age series of PET measures of brain glucose uptake spanning birth to adulthood (32), along with existing MRI volumetric data (36), to calculate the brain’s total glucose use from birth to adulthood, which we compare with body growth rate. We estimate total brain glucose uptake by age (inclusive of all oxidative and nonoxidative functions), which we compare with two measures of whole-body energy expenditure: RMR, reflecting maintenance functions only, and daily energy requirements (DER), reflecting the combination of maintenance, activity, and growth. We hypothesized that ages of peak substrate competition (i.e., competition for glucose) between brain and body would be aligned developmentally with the age of slowest childhood body growth, and more generally that growth rate and brain glucose use would covary inversely during development, as is predicted by the concept of a trade-off between brain metabolism and body growth in human life-history evolution. 

Daily glucose use by the brain peaks at 5.2 y of age at 167.0 g/d and 146.1 g/d in males and females, respectively. These values represent 1.88- and 1.82-times the daily glucose use of the brain in adulthood (Fig. 1 A and B and SI Appendix, Fig. S2), despite the fact that body size is more than three-times as large in the adult.

Glucose use of the human brain by age. (A) Grams per day in males. (B) Grams per day in females; dashed horizontal line is adult value (A and B). (C) Glucose_rmr% (solid line) and glucose_der% (dashed line) in males. (D) Glucose_rmr% (solid line) and glucose_der% (dashed line) in females.

The most relevant data is the line highlighted in yellow below, showing brain consumption of glucose peaks at 40% (of total body consumption) around 5 years old and drops to 20% in adulthood.

Our findings agree with past estimates indicating that the brain dominates the body’s metabolism during early life (31). However, our PET-based calculations reveal that the magnitude of brain glucose uptake, both in absolute terms and relative to the body’s metabolic budget, does not peak at birth but rather in childhood, when the glucose used by the brain comprises the equivalent of 66% of the body’s RMR, and roughly 43% of total expenditure. These findings are in broad agreement with past clinical work showing that the body’s mass-specific glucose production rates are highest in childhood, and tightly linked with the brain’s metabolic needs (40). Whereas past attempts to quantify the contribution of the brain to the body’s metabolic expenditure suggested that the brain accounted for a continuously decreasing fraction of RMR as the brain-to-body weight ratio declined with age (25, 31), we find a more complex pattern of substrate trade-off. Both glucose_rmr% and glucose_der% decline in the first half-year as a fast but decelerating pace of body growth established in utero initially outpaces postnatal increases in brain metabolism. Beginning around 6 mo, increases in relative glucose use are matched by proportionate decreases in weight growth, whereas ages of declining brain glucose uptake in late childhood and early adolescence are accompanied by proportionate increases in weight growth. The relationships that we document between age changes in brain glucose demands and body-weight growth rate are particularly striking in males, who maintain these inverse linear trends despite experiencing threefold changes in brain glucose demand and body growth rate between 6 mo and 13 y of age. In females, an earlier onset of pubertal weight gain leads to earlier deviations from similar linear inverse relationships.

                                     

What the researchers then did was to see how the growth rate of the brain is correlated to the growth rate of the body. In effect that what they found was that the growth of the body has to slow down to allow the energy hungry brain to develop.  One the brain has passed its peak energy requirement at about 5 years old, body growth can then gradually accelerate. 

The brain is the red line, the body is blue. The chart on the left is males and the one on the right is females. 

So, we might suspect that in 2 to 4-year olds who seem not to be growing as fast as we might expect, the reason is that their brain is over-growing, a key feature of classic autism.

Glucose_der% and body-weight growth rate. Glucose_der% and weight velocities plotted as SD scores to allow unitless comparison. (A) Glucose_der% (red dots) and dw/dt (blue dots) by age in males. (B) Glucose_der% (red dots) and dw/dt (blue dots) by age in females

Brain Overgrowth in Autism

As has been previous commented on in this blog, Eric Courchesne has pretty much figured out what goes wrong in the growth trajectory of the autistic brain; that was almost 15 years ago.

Brain development in autism: early overgrowth followed by premature arrest of growth.

Courchesne E

Author information

Abstract

Due to the relatively late age of clinical diagnosis of autism, the early brain pathology of children with autism has remained largely unstudied. The increased use of retrospective measures such as head circumference, along with a surge of MRI studies of toddlers with autism, have opened a whole new area of research and discovery. Recent studies have now shown that abnormal brain overgrowth occurs during the first 2 years of life in children with autism. By 2-4 years of age, the most deviant overgrowth is in cerebral, cerebellar, and limbic structures that underlie higher-order cognitive, social, emotional, and language functions. Excessive growth is followed by abnormally slow or arrested growth. Deviant brain growth in autism occurs at the very time when the formation of cerebral circuitry is at its most exuberant and vulnerable stage, and it may signal disruption of this process of circuit formation. The resulting aberrant connectivity and dysfunction may lead to the development of autistic behaviors. To discover the causes, neural substrates, early-warning signs and effective treatments of autism, future research should focus on elucidating the neurobiological defects that underlie brain growth abnormalities in autism that appear during these critical first years of life.

Research from 2017: -

Rapid brain growth in infancy may signal autism

Early brain development in infants at high risk for autism spectrum disorder

Conclusion

A record of children’s height and weight and even head circumference is usually collected by their doctor. In an earlier post I did ask why they bother if nobody is checking this data. If a child falls from the 90^th percentile in height to the 20^th, something clearly is going on.

When I discussed this with a pediatric endocrinologist a few years ago, we then measured bone-age and IGF-1. If you have low IGF-1 and retarded bone age you might opt for some kind of growth hormone therapy.

In what is broadly defined as autism, I think we have some distinctly different things possibly happening: -

Group AMD

Energy conversion in the brain is less efficient than it should be due to a combination of impaired vascular function and impaired mitochondrial enzyme complex production. No symptoms are apparent and developmental milestones are achieved.  As the brain creates more synapses it energy requirement grows until the day when the body has some external insult like a viral infection, and the required power is not available, triggering a “power outage” which appears as the regression into autism. In biological terms there has been death of neurons and demyelination.

Group Sliding Down the Percentiles 

This group looks like a sub-set of classic autism. The brain grows too rapidly in the first two years after birth and this causes the expected slowing of body growth to occur much earlier than in typical children. This manifests itself in the child tumbling down the percentiles for height and weight.

The brain then stops growing prematurely, reducing energy consumption and allowing body growth to accelerate and the child slowly rises back up the height/weight percentiles.

Perhaps all those excessive synapses that were not pruned correctly are wasting glucose and so delay the growth of the rest of the body?   
In the sliding down the growth percentiles group, does this overgrowing brain ever exceed maximum available power? Maybe it just grows too fast and so mal-develops, as suggested by Courchesne, or maybe it grows too fast and cannot fuel correct development?  What happens if you increase maximum available power in this group, in the way some athletes use to enhance their performance/cheat?

All I know for sure is that in Monty, aged 14 with autism, increasing eNOS (endothelial nitric oxide synthase) using agmatine seems to make him achieve much more, with the same daily glucose consumption. I wonder what would happen if Agmatine was given to very young children as soon as it was noted that they were tumbling down the height percentiles?  This is perhaps what the pediatric endocrinologists should be thinking about, rather than just whether or not to administer growth hormones/IGF-1.

If you could identify Group AMD before the “power outage” you might be able to boost maximum power production or reduce body growth slightly and hence avoid the brain ever being starved of energy. That way you would not have most regressive autism.