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Showing posts with label SIRT1. Show all posts
Showing posts with label SIRT1. Show all posts

Wednesday, 14 December 2016

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 GPX (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 GPX (glutathione peroxodases)

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

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

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

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


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 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.

  

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).




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.

  


  

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.




Here is the excellent French paper on MOCOS:-



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.