Today’s post was going to be about FMT super-donors, but instead we have a post about new insights into using oxytocin to treat autism. From personal experience I can say that you really can target oxytocin receptors to affect mood/behavior; I have no personal experience of FMT (fecal microbiota transplants), but thousands of people use it for many conditions. The FMT post will be next.
Oxytocin and vasopressin are two hormones, made in the hypothalamus, that are established targets for autism treatment. They are released into the bloodstream where they carry out their best-known functions, but they are also released from the hypothalamus directly into the brain where these hormones have entirely different functions.
Both oxytocin and vasopressin can be given as nasal sprays to enter the central nervous system (CNS) rather than just the blood stream. This means you get the brain effects of the hormone, also known as the “central effects”.
As was discussed previously in this blog and is highlighted more recently in the article below, you can use certain bacteria in the gut to signal to the hypothalamus to produce more oxytocin. This is really clever and it works in humans, not just research animals. It also has the advantage of producing a more continuous effect than is found using the intranasal method to deliver oxytocin.
When you sever the vagus nerve, the bacteria in the gut continues to produce the required chemicals, but the signal to the brain has been lost. The hypothalamus no longer produces increased oxytocin and so the behavioral/mood effect is lost. This has been proven in the research.
Gut microbes may treat social difficulties in autism mice
In science speak, “the results suggest that a peptide or metabolite produced by bacteria may modulate host oxytocin secretion for potential public or personalized health goals”. It also appears that oxytocin improves wound healing. So perhaps old people with leg ulcers, which never seem to get better, might benefit from a daily dose of L. reuteri DSM 17938, it also might make them feel better due to those central effects.
Oxytocin in the brain acts via oxytocin receptors
As we learned years ago in this blog, you can increase the effect (turn up the volume) of receptors using a PAM (positive allosteric modulator). Interestingly, magnesium is a PAM of the oxytocin receptor (OTR). Many people with autism are supplementing magnesium, perhaps those using intranasal oxytocin should join them.
A very recent paper has investigated in detail how oxytocin receptors function.
The peptide hormone oxytocin modulates socioemotional behavior and sexual reproduction via the centrally expressed oxytocin receptor (OTR) across several species. Here, we report the crystal structure of human OTR in complex with retosiban, a nonpeptidic antagonist developed as an oral drug for the prevention of preterm labor. Our structure reveals insights into the detailed interactions between the G protein–coupled receptor (GPCR) and an OTR-selective antagonist. The observation of an extrahelical cholesterol molecule, binding in an unexpected location between helices IV and V, provides a structural rationale for its allosteric effect and critical influence on OTR function. Furthermore, our structure in combination with experimental data allows the identification of a conserved neurohypophyseal receptor-specific coordination site for Mg2+ that acts as potent, positive allosteric modulator for agonist binding. Together, these results further our molecular understanding of the oxytocin/vasopressin receptor family and will facilitate structure-guided development of new therapeutics.
Magnesium and mood disorders: systematic review and meta-analysis
Another consequence of ERβ under-expression in autism
Also interesting to those following autism research, is the role of ERβ (estrogen receptor beta). It is well known that in the brains of those with autism, there is a lack of ERβ. A lack of ERβ is likely to lead to lower oxytocin in the brain and CSF (spinal fluid). In many types of autism, we know that the level of oxytocin in CSF is reduced.
If you activate ERβ you both increase expression of oxytocin receptor (OTR) and also increase the level of oxytocin measured in the CSF. You can activate ERβ with estrogens, like estradiol or even phytoestrogens like soy. The ideal therapy to use would be DHED.
The cheap diuretic spironolactone may very well indirectly increase the level of oxytocin in CSF.
Oxytocin and Estrogen Receptor β in the Brain: An Overview
Oxytocin (OT) is a neuropeptide synthesized primarily by neurons of the paraventricular and supraoptic nuclei of the hypothalamus. These neurons have axons that project into the posterior pituitary and release OT into the bloodstream to promote labor and lactation; however, OT neurons also project to other brain areas where it plays a role in numerous brain functions. OT binds to the widely expressed OT receptor (OTR), and, in doing so, it regulates homeostatic processes, social recognition, and fear conditioning. In addition to these functions, OT decreases neuroendocrine stress signaling and anxiety-related and depression-like behaviors. Steroid hormones differentially modulate stress responses and alter OTR expression. In particular, estrogen receptor β activation has been found to both reduce anxiety-related behaviors and increase OT peptide transcription, suggesting a role for OT in this estrogen receptor β-mediated anxiolytic effect. Further research is needed to identify modulators of OT signaling and the pathways utilized and to elucidate molecular mechanisms controlling OT expression to allow better therapeutic manipulations of this system in patient populations.
NAD and Nicotinamide Riboside to boost Oxytocin
Today we see that recent research from Japan shows that in those people with autism who have reduced NAD, they may well be able to improve behavior/mood by increasing the level of their oxytocin using Nicotinamide Riboside (NR).
Nicotinamide riboside (NR) is a special form of vitamin B3, sold as an expensive supplement. The FDA say it is safe for use in humans.
Nicotinamide riboside supplementation corrects deficits in oxytocin, sociability and anxiety of CD157 mutants in a mouse model of autism spectrum disorder
Oxytocin (OT) is a critical molecule for social recognition and memory that mediates social and emotional behaviours. In addition, OT acts as an anxiolytic factor and is released during stress. Based on the activity of CD38 as an enzyme that produces the calcium-mobilizing second messenger cyclic ADP-ribose (cADPR), CD157, a sister protein of CD38, has been considered a candidate mediator for the production and release of OT and its social engagement and anti-anxiety functions. However, the limited expression of CD157 in the adult mouse brain undermined confidence that CD157 is an authentic and/or actionable molecular participant in OT-dependent social behaviour. Here, we show that CD157 knockout mice have low levels of circulating OT in cerebrospinal fluid, which can be corrected by the oral administration of nicotinamide riboside, a recently discovered vitamin precursor of nicotinamide adenine dinucleotide (NAD). NAD is the substrate for the CD157- and CD38-dependent production of cADPR. Nicotinamide riboside corrects social deficits and fearful and anxiety-like behaviours in CD157 knockout males. These results suggest that elevating NAD levels with nicotinamide riboside may allow animals with cADPR- and OT-forming deficits to overcome these deficits and function more normally.
NR elevates brain NAD+ and cerebrospinal OT
Social preference deficit and anxiety of CD157KO males are best corrected at a relatively low dose of NR
The results demonstrated that the daily oral administration of NR rescued the social behavioural impairments observed in male CD157KO mice. NR had essentially no effects on social behaviour in wild-type male mice. The beneficial effects of NR appear to depend on restoration of CSF OT levels because the NR-induced OT elevation was only detected in CD157KO mice, which have a CSF OT deficit.
In the course of identifying a nutritional intervention for CD157KO mice, we reproduced the anxiety-like and social-avoidance-like deficits reported previously. Reproducibly lower levels of CSF OT in male CD157KO mice make these mice an attractive model of autism, anxiety disorder, or social avoidance in neurodegenerative diseases. Significantly, this model responds to both OT and NR as a treatment.
The challenge of polygenic diseases of incomplete penetrance is that they are difficult to understand mechanistically. Multiple genetic and environmental (biochemical) factors may converge to dysregulate pathways that are altered in common conditions such as ASD. We note that one potentially hopeful point when studying polygenetic diseases is that brain systems are redundant, and thus, it may be possible to increase normal functions that are only partially encoded by genetically damaged circuitry.
NAD+ is consumed by CD38 in formation of cyclic ADP-ribose. It then participates in OT release in the hypothalamus. In our study, ADP-ribosyl cyclase activity was maintained at a similar range as that in wild-type animals (data not shown). A recent study suggested that NR supplementation did not change CD38 expression. However, in vitro studies have shown that NAD+ applied to the mouse hypothalamus leads to OT release. It is reasonable to assume that an elevation in NAD+ levels by NR in the hypothalamus is responsible for repair of the OT release.
Future work will probe CD38 dependence and the cell-type dependence of the beneficial effects of NR on CD157KO behaviour, the potential benefits of NR in other ASD models, and the potential of NR to become a safe nutritional intervention, in addition to OT, for at least some types of ASD in human populations.
NAD+ is reduced in older people
There is a lot of research into combating the effects of aging. It is agreed that the older you get, the less NAD+ you have and so research has looked at numerous ways to raise it.
The CD157KO mice model of autism does feature reduced NAD+, but nobody knows how common reduced NAD+ is in autism.
If you have low levels of NAD+ there will be negative consequences.
I think you can consider NAD+ depletion in a similar way to oxidative stress, both are inevitable and damaging features of aging.
Most healthy younger people are likely wasting their time and money worrying about oxidative stress and NAD+. These are the people with “detox” diets and juices.
However, most old people and some young people with autism really stand to benefit from correcting oxidative stress and any reduced NAD+.
Therapeutic potential of NAD-boosting molecules: the in vivo evidence
Hallmarks of NAD homeostasis
NAD+ is not merely a redox co-factor, it is also a key signaling molecule that controls cell function and survival in response to environmental changes such as nutrient intake and cellular damage. Fluctuations in NAD impact mitochondrial function and metabolism, redox reactions, circadian rhythm, immune response and inflammation, DNA repair, cell division, protein-protein signaling, chromatin and epigenetics.
There are many ways to boost NAD+.
NAD+ Precursors
Niacin/ nicotinic acid (NA), Nicotinamide riboside (NR) Nicotinamide (NAM) etc.
CD38 Inhibitors
Flavonoids (Quercetin, Luteolin, Apigenin, fisetin, rutin and naringin)
Luteolinidin. Kuromanin/ Chrysanthemin, an anthocyanin (food pigment)
PARP Inhibitors
BGB-290, Olaparib, Rucaparib, Veliparib, CEP-9722, E7016, Talazoparib, Iniparib, Niraparib, PJ34, DPQ, 3-aminobenzamide
SARM Inhibitors
XAV939
NAMPT Activators
P7C3
Conclusion
Some readers of this blog do give intranasal oxytocin as a therapy. There have been numerous studies on children with autism, some discussed in earlier posts. Oxytocin needs to be kept chilled, not to lose its potency.
Eleven previous posts in this blog refer to Oxytocin.
As to whether stimulating oxytocin receptors is going to be worthwhile in your case of autism, you will just have to try it and see.
I found that the Biogaia Protectis probiotic (L. reuteri DSM 17938) had very clear effects, which were very much hallmark effects of oxytocin. This is easy and inexpensive to try.
Some readers of this blog do use Nicotinamide Riboside (NR), which we saw today can increase oxytocin by increasing NAD+.
There are very many reasons why you do not want to be lacking in NAD+, other than oxytocin, but if you already have plenty NAD+ you will unlikely see a benefit from yet more.
Magnesium is a very common autism supplement; it is often given with vitamin B6; both can be used to treat stress.