The Purkinje-RORa-Estradiol-Neuroligin-KCC2 axis in Autism

Add testosterone/estradiol to those dysfunctional hormones

This blog is about noticing connections and making things a little simpler to understand.  Today’s post is going to be a good example; all those odd sounding things like Purkinje cells and neuroligins all fitting nicely together.

Today we see how a central hormonal dysfunction (testosterone/estradiol) can lead to an ion channel dysfunction (NKCC1/KCC2) at one end of the chain and at the other explains the absence of many Purkinje cells in the autistic cerebellum, which leads to some of the observed features of autism.

I am calling it the Purkinje-RORa-Estradiol-Neuroligin-KCC2 axis, or Purkinje-KCC2 axis for short.

We also get to see how melatonin fits in here and see why disturbed sleeping patterns should be expected in someone affected by the Purkinje- KCC2 axis.

I should point out that not everyone with autism is likely affected by the Purkinje-NKCC1 axis, but I think it will apply to a majority of those with non-regressive, multigenic, strictly defined autism (SDA).

We saw in a recent post how the enzyme aromatase acts in the so-called  testosterone – estradiol shunt.

I suggested that lack of aromatase was leading to too little estradiol which then affected neuroligin 2 (NL2) which then caused down-regulation of the KCC2 cotransporter that takes chloride out of neurons. This then caused neurons to remain in a permanent immature state.

Digging a little deeper we find recent research that shows how the control loops that balance aromatase act through RORA/RORα, RORa  (retinoic acid-related orphan receptor alpha.

Source:-  http://dx.doi.org/10.1371/journal.pone.0017116.g005

The schematic illustrates a mechanism through which the observed reduction in RORA in autistic brain may lead to increased testosterone levels through downregulation of aromatase. Through AR, testosterone negatively modulates RORA, whereas estrogen upregulates RORA through ER.

androgen receptor = AR

estrogen receptor = ER

RORα (retinoic acid-related orphan receptor alpha.)

RORα certainly has a long full name. Retinoic acid is a metabolite of vitamin A (retinol).

RORα does some clever things.

RORα is necessary for normal circadian rhythms

ROR-alpha is expressed in a variety of cell types and is involved in regulating several aspects of development, inflammatory responses, and lymphocyte development

RORα is involved in processes that regulate metabolism, development, immunity, and circadian rhythm and so shows potential as drug targets. Synthetic ligands have a variety of potential therapeutic uses, and can be used to treat diseases such as diabetes, atherosclerosis, autoimmunity, and cancer. T0901317 and SR1001, two synthetic ligands, have been found to be RORα and RORγ inverse agonists that suppress reporter activity and have been shown to delay onset and clinical severity of multiple sclerosis and other Th17 cell-mediated autoimmune diseases. SR1078 has been discovered as a RORα and RORγ agonist that increases the expression of G6PC and FGF21, yielding the therapeutic potential to treat obesity and diabetes as well as cancer of the breast, ovaries, and prostate. SR3335 has also been discovered as a RORα inverse agonist.

RORs are also called nuclear melatonin receptors. Many people with autism take melatonin to balance circadian rhythms and fall asleep.

The reduced estrogen levels in women during menopause likely caused them not to sleep due to the effect on RORα.

So it would appear that some of what is good for menopausal women may actually be helpful for some people with autism.

Many Genes affected by RORα

Study uncovers molecular targets of autism-linked RORA gene

Most exciting, the researchers say, is that 426 of RORA’s gene targets are listed in AutismKB, a database of autism candidates maintained by scientists at Peking University in Beijing, and 49 in SFARI Gene.

Therapeutic Effect of a Synthetic RORα/γ Agonist in an Animal Model of Autism

Therapeutic Effect of a Synthetic RORα/γ Agonist in an Animal Model of Autism

Autism is a developmental disorder of the nervous system associated with impaired social communication and interactions as well excessive repetitive behaviors. There are no drug therapies that directly target the pathology of this disease. The retinoic acid receptor-related orphan receptor α (RORα) is a nuclear receptor that has been demonstrated to have reduced expression in many individuals with autism spectrum disorder (ASD). Several genes that have been shown to be downregulated in individuals with ASD have also been identified as putative RORα target genes. Utilizing a synthetic RORα/γ agonist, SR1078, that we identified previously, we demonstrate that treatment of BTBR mice (a model of autism) with SR1078 results in reduced repetitive behavior. Furthermore, these mice display increased expression of ASD-associated RORα target genes in both the brains of the BTBR mice and in a human neuroblastoma cell line treated with SR1078. These data suggest that pharmacological activation of RORα may be a method for treatment of autism.

For those who like natural substances, some research from Japan.

Isoflavones enhance interleukin-17 gene expression via retinoic acid receptor-related orphan receptors α and γ.

            Abstract

The retinoic acid receptor-related orphan receptors α and γ (RORα and RORγ), are key regulators of helper T (Th)17 cell differentiation, which is involved in the innate immune system and autoimmune disorders. In this study, we investigated the effects of isoflavones on RORα/γ activity and the gene expression of interleukin (IL)-17, which mediates the function of Th17 cells. In doxycycline-inducible CHO stable cell lines, we found that four isoflavones, biochanin A (BA), genistein, formononetin, and daidzein, enhanced RORα- or RORγ-mediated transcriptional activity in a dose-dependent manner. In an activation assay of the Il17a promoter using Jurkat cells, these compounds enhanced the RORα- or RORγ-mediated activation of the Il17a promoter at concentrations of 1 × 10(-6)M to 1 × 10(-5)M. In mammalian two-hybrid assays, the four isoflavones enhanced the interaction between the RORα- or RORγ-ligand binding domain and the co-activator LXXLL peptide in a dose-dependent manner. In addition, these isoflavones potently enhanced Il17a mRNA expression in mouse T lymphoma EL4 cells treated with phorbol myristate acetate and ionomycin, but showed slight enhancement of Il17a gene expression in RORα/γ-knockdown EL4 cells. Immunoprecipitation and immunoblotting assays also revealed that BA enhanced the interaction between RORγt and SRC-1, which is a co-activator for nuclear receptors. Taken together, these results suggest that the isoflavones have the ability to enhance IL-17 gene expression by stabilizing the interactions between RORα/γ and co-activators. This also provides the first evidence that dietary chemicals can enhance IL-17 gene expression in immune cells.

Genistein is a common supplement.  It is a pytoestrogen and unfortunately these substances lack potency in real life.  In test tubes they have interesting properties, but they are poorly absorbed when taken orally and so unless they are modified they are likely to have no effect in the usual tiny doses used in supplements.

This is true with very many products sold as supplements.

Sometimes care is taken to improve bioavailability as with some expensive curcumin supplements, like Longvida.

Trehalose, a supplement referred to recently in comments on this blog, is another interesting natural substance that lacks bioavailablity.  Analogs of this natural substance have been produced that are much better absorbed and are now potential drugs.

Lentztrehalose A, B, C

Purkinje Cells

Back in 2013 I wrote a post about Purkinje cells.

          Pep up those Purkinje cells

Loss of Purkinje cells is one of the few non-disputed abnormalities in autism. 

These cells are some of the largest neurons in the human with an intricately elaborate dendritic arbor, characterized by a large number of dendritic spines. Purkinje cells are found within the Purkinje layer in the cerebellum. Purkinje cells are aligned like dominos stacked one in front of the other. Their large dendritic arbors form nearly two-dimensional layers through which parallel fibers from the deeper-layers pass. These parallel fibers make relatively weaker excitatory (glutamatergic) synapses to spines in the Purkinje cell dendrite, whereas climbing fibers originating from the inferior olivary nucleus in the medulla provide very powerful excitatory input to the proximal dendrites and cell soma. Parallel fibers pass orthogonally through the Purkinje neuron's dendritic arbor, with up to 200,000 parallel fibers^[2] forming a Granule-cell-Purkinje-cell synapse with a single Purkinje cell. Each Purkinje cell receives ca 500 climbing fiber synapses, all originating from a single climbing fiber.^[3] Both basket and stellate cells (found in the cerebellar molecular layer) provide inhibitory (GABAergic) input to the Purkinje cell, with basket cells synapsing on the Purkinje cell axon initial segment and stellate cells onto the dendrites.

Purkinje cells send inhibitory projections to the deep cerebellar nuclei, and constitute the sole output of all motor coordination in the cerebellar cortex.

In humans, Purkinje cells can be harmed by a variety causes: toxic exposure, e.g. to alcohol or lithium; autoimmune diseases; genetic mutations causing spinocerebellar ataxias, Unverricht-Lundborg disease, or autism; and neurodegenerative diseases that are not known to have a genetic basis, such as the cerebellar type of multiple system atrophy or sporadic ataxias.

Purkinje cells are some of the largest neurons in the human brain and the most important.

Neuronal maturation during development is a multistep process regulated by transcription factors. The transcription factor RORα (retinoic acid-related orphan receptor α) is necessary for early Purkinje cell maturation but is also expressed throughout adulthood.

The active form (T₃) of thyroid hormone  controls critical aspects of cerebellar development, such as migration of postmitotic neurons and terminal dendritic differentiation of Purkinje cells. T₃ action on the early Purkinje cell dendritic differentiation process is mediated by RORα.

In autism we have seen that oxidative stress may lead to low levels of T₃ in the autistic brain.  We now see that low levels of RORα are also likely in autsim.

The combined effect would help explain the loss of Purkinje cells in autism.

Induction of early Purkinje cell dendritic differentiation by thyroid hormone requires RORα

Mature Purkinje Cells Require the Retinoic Acid-Related Orphan Receptor-α (RORα) to Maintain Climbing Fiber Mono-Innervation and Other Adult Characteristics

Regional Alterations in Purkinje Cell Density in Patients with Autism

Neuropathological studies, using a variety of techniques, have reported a decrease in Purkinje cell (PC) density in the cerebellum in autism. We have used a systematic sampling technique that significantly reduces experimenter bias and variance to estimate PC densities in the postmortem brains of eight clinically well-documented individuals with autism, and eight age- and gender-matched controls. Four cerebellar regions were analyzed: a sensorimotor area comprised of hemispheric lobules IV–VI, crus I & II of the posterior lobe, and lobule X of the flocculonodular lobe. Overall PC density was thus estimated using data from all three cerebellar lobes and was found to be lower in the cases with autism as compared to controls. These findings support the hypothesis that abnormal PC density may contribute to selected clinical features of the autism phenotype.

Estradiol – Neuroligin 2 to KCC2

We saw in a recent post how reduced levels of estradiol could lead to KCC2 underexpression via the action of neuroligin 2.

Neuroligins, Estradiol and Male Autism

Conclusion

So in my grossly oversimplified world of autism, I think I have a plausible case for the Purkinje-KCC2 axis.  I think that in addressing this axis numerous other issues would also be solved ranging from sleep issues to those hundreds of other genes whose regulation is at least partly governed by RORα.

The KCC2 end of the axis can be treated by bumetanide, diamox/acetazolamide, potassium bromide and possibly by intranasal IGF-1/insulin.  

How to address the rest of the Purkinje-KCC2 axis?

·        More RORα, or just a RORα agonist.

·        More aromatase

·        Genistein may help, but you would need it by the bucket load, due to bioavailability issues

·        Estrogen receptor agonists

·        Exogenous estradiol

The simplest is the last one and really should be trialed on adult males with autism.  The dose would need to be much lower than the feminizing dose, so 0.2mg would seem a good starting dose for such a study.

Due to the feedback loops somethings may work short term, but not long term. 

Treating KCC2 Down-Regulation in Autism, Rett/Down Syndromes, Epilepsy and Neuronal Trauma ?

In this composite image, a human nerve cell derived from a patient with Rett syndrome shows significantly decreased levels of KCC2 compared to a control cell.  This will be equally true of about 50% people with classic autism, people with Down syndrome, many with TBI and many with epilepsy

In a recent post I highlighted an idea from the epilepsy research to treat a common phenomenon also found in much classic autism.  Neurons are in an immature state with too much intracellular chloride, the transporter that brings it in, called NKCC1, is over-expressed and the one that takes it out, KCC2, is under-expressed.  The net result is high levels of intracellular chloride and this leaves the brain in an over-excited state (GABA working in reverse) reducing cognitive function and with a reduced threshold to seizures.

The epilepsy research noted that increased BDNF is one factor that down regulates KCC2, which would have taken chloride out of the cells.  So it was suggested to block BDNF, or something closely related called trkB.

Unfortunately there is no easy way to this.  But I did some more digging and found various other ways to upregulate KCC2.

There is indeed a clever safe way that may achieve this and it is a therapy that I have already suggested for other reasons, intranasal insulin.

BDNF is a neurotrophin and other neurothrophins also have the ability to regulate KCC2. IGF-1 is another such neurotrophin and we even have very recent experimental data showing its effect on KCC2.

Regular readers will know that several trials with IGF-1, or analogs thereof, are underway.

I actually am rather biased against IGF-1 as a therapy, since in my son’s case the level of IGF-1 in blood is already high.  So I do not want to inject him with IGF-1 or even give him an oral analog.

However by using intranasal insulin the effect would be just within the CNS and insulin binds at the same receptors as IGF-1. So if IGF-1 upregulates KCC2 so will insulin.

We know from extensive existing trial data and direct feedback from one researcher that intranasal insulin is well tolerated and has no effect outside the CNS.

So rather to my surprise there seems to be a safe, cheap way to treat KCC2 down-regulation and this would also be applicable in epilepsy, traumatic brain injury (TBI) and any other condition involving immature neurons or neuronal trauma. 

The Science

There is a very thorough recent review paper that looks at all the ways that KCC2 expression is regulated.

Current view on the functional regulation of the neuronal K⁺-Cl⁻ cotransporter KCC2

The epilepsy researchers consider trkB, top left in the figure below.  But just next to it is IGFR which can be activated by both insulin and IGF-1.

In Rett syndrome they are already using IGF-1 to modulate KCC2.  The research is done at Penn State.

As you can see in the figure the mechanism for IGF-1 and insulin is not the same as BNDF/trkb, but Penn State have already shown that IGF-1 works in vitro.

We saw in early posts regarding intranasal insulin that this was a safe way to deliver insulin to the brain without effects in the rest of the body.

So we know it is safe and in theory it should achieve the same thing that the Penn State researchers are trying to achieve.

Signaling pathways controlling KCC2 function. The regulation of KCC2 activity is mediated by many proteins including kinases and phosphatases. It affects either the steady state protein expression at the plasma membrane or the KCC2 protein recycling. All the different pathways are explained and discussed in the main text. The schematic drawings of KCC2 as well as other membrane molecules do not reflect their oligomeric structure. GRFα2, GDNF family receptor α2; BDNF, Brain-derived neurotrophic factor; TrKB, Tropomyosin receptor kinase B; Insulin, Insulin-like growth factor 1 (IGF-1); IGFR, Insulin-like growth factor 1 receptor; mGluR1, Group I metabotropic glutamate receptor; 5-HT-2A, 5-hydroxytryptamine (5-HT) type 2A receptor; mAChR, Muscarinic acetylcholine receptor; NMDAR, N-methyl-D-aspartate receptor; mZnR, Metabotropic zinc-sensing receptor (mZnR); GPR39, G-protein-coupled receptor (GPR39); ERK-1,2, Extracellular signal-regulated kinases 1, 2; PKC, Protein kinase C; Src-TK, cytosolic Scr tyrosine kinase; WNKs1–4, with-no-lysine [K] kinase 1–4; SPAK, Ste20p-related proline/alanine-rich kinase; OSR1, oxidative stress-responsive kinase -1; Tph, Tyrosine phosphatase; PP1, protein phosphatase 1; Egr4, Early growth response transcription factor 4; USF 1/2, Upstream stimulating factor 1, 2.

The Penn State research on using IGF-1 to increase KCC2 in Rett Syndrome

Discovery of a new drug target could lead to novel treatment for severe autism

The researchers also showed that treating diseased nerve cells with insulin-like growth factor 1 (IGF1) elevated the level of KCC2 and corrected the function of the GABA neurotransmitter. IGF1 is a molecule that has been shown to alleviate symptoms in a mouse model of Rett Syndrome and is the subject of an ongoing phase-2 clinical trial for the treatment of the disease in humans.

"The finding that IGF1 can rescue the impaired KCC2 level in Rett neurons is important not only because it provides an explanation for the action of IGF1," said Xin Tang, a graduate student in Chen's Lab and the first-listed author of the paper, "but also because it opens the possibility of finding more small molecules that can act on KCC2 to treat Rett syndrome and other autism spectrum disorders."

More Melatonin?

As Agnieszka pointed out in the previous post it appears that extremely high doses of melatonin can increase KCC2 in traumatic brain injury (TBI). In this example BDNF was increased by the therapy, so I think TBI may be a specific case.  In most autism BDNF starts out elevated and in epilepsy, seizures are known to increase BDNF and that process is seen as down regulating KCC2 expression.  So in much autism and epilepsy you want less BDNF.

Melatonin attenuates neuronal apoptosis through up-regulation of K+ -Cl- cotransporter KCC2 expression following traumatic brain injury in rats

Compared with the vehicle group, melatonin treatment altered the down-regulation of KCC2 expression in both mRNA and protein levels after TBI. Also, melatonin treatment increased the protein levels of brain-derived neurotrophic factor (BDNF) and phosphorylated extracellular signal-regulated kinase (p-ERK). Simultaneously, melatonin administration ameliorated cortical neuronal apoptosis, reduced brain edema, and attenuated neurological deficits after TBI. In conclusion, our findings suggested that melatonin restores KCC2 expression, inhibits neuronal apoptosis and attenuates secondary brain injury after TBI, partially through activation of BDNF/ERK pathway.

More Science

There is plenty more science on this subject.

It is suggested that in addition to IGF-1/insulin it may be necessary to involve Protein tyrosine kinase (PTK).

Insulin-Like Growth Factor 1 and a Cytosolic Tyrosine Kinase Activate Chloride Outward Transport during Maturation of Hippocampal Neurons

Protein tyrosine kinase (PTK) phosphorylation is considered a key biochemical event in numerous cellular processes, including proliferation, growth, and differentiation, and has also been implicated in synaptogenesis. Protein tyrosine kinases are subdivided into the cytosolic nonreceptor family and the transmembrane growth factor receptor family, which includes receptors for insulin and insulin-like growth factor (IGF-1). The maturation of postsynaptic inhibition may require both a cytoplasmic PTK, which increases GABA_A receptor-mediated currents, and insulin, which was shown to induce a rapid translocation of GABA_A receptors from intracellular compartments to the plasma membrane. KCC2 is also known to have a C-terminal PTK consensus site. Therefore, the maturation of postsynaptic inhibition may, in addition to other mechanisms, also involve the effects of PTK and insulin acting on KCC2.

Development and regulation of chloride homeostasis in the central nervous system

Conclusion

I would infer from all this science that intranasal insulin is likely to increase KCC2 expression in the brain, certainly worthy of investigation.

Protein tyrosine kinase (PTK) phosphorylation is considered a key biochemical event in numerous cellular processes.  This might be a limiting factor on the effectiveness of insulin in raising KCC2.  This would then add yet more complexity.

Protein kinases are enzymes that add a phosphate(PO₄) group to a protein, and can modulate its function.  A protein kinase inhibitor is a type of enzyme inhibitor that blocks the action of one or more protein kinases.

Abnormal protein tyrosine kinases (PTKs) cause many human leukaemias, so there is research into PTK inhibitors (PTK-Is).

As we know from Abha Chauhan’s mammoth book, oxidative stress controls the activities of PTK.

More Melatonin!

  Older people, those with autism, those with reflux, IBS/IBD and other GI problems generally have low levels of melatonin.  Poor sleep is but one consequence.

I have previously written about the potential for melatonin in autism and I do not just mean to improve sleeping disorders.  Melatonin does a great deal more than that.

Melatonin for Kids with Autism, and indeed their Parents

MitoE, MitoQ and Melatonin as possible therapies for Mitochondrial Dysfunction in Autism. Or Dimebon (Latrepirdine) from Russia?

Most substances I write about in this blog are either prescription drugs or quite expensive supplements.

Other than in a small number of countries like the United Kingdom, melatonin is widely available as a cheap supplement, but that does not mean it is not a drug.

In humans melatonin is produced in two different places and it appears in two orders of magnitude.  Traditionally melatonin is considered to be a hormone produced by the pineal gland in the brain, but far more melatonin is actually produced in your intestines, where it has completely different functions.

Many people have low levels of melatonin, for example people with autism/schizophrenia/bipolar, older people and people with intestinal problems ranging from reflux/GERD/GORD to ulcerative colitis.

We know that melatonin is a potent antioxidant, but there are numerous other antioxidants.  Damaging oxidants vary both by type, but also by their location and so if you are clever you would match your antioxidant(s) very specifically to the oxidant(s).  

So if you have elevated risk of prostate cancer, take lycopene, it accumulates in fatty tissue and the prostate is surrounded by a fatty deposit called periprostatic adipose tissue (PPAT).  It is not agreed whether lycopene can cross the blood brain barrier in humans; it does for sure in rats.  

It seems that in people with type 2 diabetes there is oxidative stress in the mitochondria of the beta cells in their pancreas.  Beta cells make insulin and in type 2 diabetes there is often a gradual loss in beta cells resulting in type 1 diabetes.  Numerous cancer studies have shown the potential of different antioxidants in different cancers, NAC in breast cancer, Sulforaphane is esophageal cancer etc.  It seems to be agreed that antioxidants are most helpful in disease prevention, rather than cure.  

  

We know that melatonin is potent at combatting oxidants in the mitochondria, so logically people with mitochondrial dysfunction might well benefit from melatonin.  It is vastly cheaper than the antioxidant drugs that target the mitochondria (MitoE, MitoQ etc).

An interesting recent study has linked low levels of melatonin in the parents of those with autism.

Low parental melatonin levels increases autism spectrum disorder risk in children

  

Background: Low melatonin levels are a frequent finding in autism spectrum disorder (ASD) patients. Melatonin is also important for normal neurodevelopment and embryonic growth. As a free radical scavenger and antioxidant melatonin is highly effective in protecting DNA from oxidative damage. Melatonin deficiency, possibly due to low CYP1A2 activity, could be a major factor, and well a common heritable variation. ASD is already present at birth. As the fetus does not produce melatonin, low maternal melatonin levels should be involved. Methods: We measured 6-sulfatoxymelatonin in urine of mothers of a child with ASD that attended our sleep clinic for people with an intellectual disability (ID), and asked for parental coffee consumption habits, as these are known to be related to CYP1A2 activity. Results: 6-Sulfatoxymelatonin levels were significantly lower in mothers than in controls (p = 0.005), as well as evening coffee consumption (p = 0.034). In mothers with a second child with ASD and/or ID, 6-sulfatoxymelatonin levels were lower compared to mothers with one child with ASD (p = 0.084), 

Conclusions: Low parental melatonin levels, likely caused by low CYP1A2 activity, seem to be a major contributor to ASD and possibly ID etiology.

I think you would also find, more generally, high levels of oxidative stress in parents of those with autism, and more importantly oxidative stress during pregnancy would have negative effects.  I think autism produces stress and stress helps produce autism.

  

The Potential Role of Melatonin on Mental Disorders: Insights from Physiology and Pharmacology 

Potency of pre–post treatment of coenzyme Q10 and melatoninsupplement in ameliorating the impaired fatty acid profile in rodent model ofautism

  

Melatonin as a stabilizerof mitochondrial function: role in diseases and aging

  

"It is now almost 60 years since the discovery of melatonin and new physiological functions of the indole continuously appear in the most recent studies worldwide. Besides the pineal gland, the existence and value of other sources of synthesis force us to rethink the established premises about the biological role of this molecule, such as the well-known regulation of circadian and reproductive cycles (Hardeland et al., 2008). In the last few years, other properties of melatonin such as antioxidant power, immunoregulatory capacity, and oncostatic action have enriched our knowledge about the pleiotropic nature of the hormone.

The role of melatonin in mitochondrial homeostasis has gained strength in the scientific community. Experimental evidence emphasizes its importance as a stabilizer of organular bioenergetics, which could be related to the             prevention of development of aging and several diseases.

  

Role of melatonin on mitochondrial dysfunction and diseases

The idea that mitochondrial dysfunction is implicated in the etiology of various diseases has been strengthened after several years of research. Initially, studies of mitochondrial diseases have focused on mitochondrial respiratory-chain diseases associated with mutations of mtDNA. However, more recent evidence shows that oxidative damage is responsible for the impairment of mitochondrial function, leading to a self-induced vicious cycle that finally culminates in necrosis and apoptosis of cells and organ failure. We are now starting to understand the mechanisms of a large list of mitochondrial-related diseases (cancer, diabetes, obesity, cardiovascular and neurodegenerative diseases, and aging); all of them seem to share the common features of disturbances of mitochondrial Ca2+, ATP, or ROS metabolism (Sheu et al., 2006). Therefore, selective prevention of such phenomena should be an effective therapy in a wide range of human diseases (Smith et al., 1999; Sheu et al., 2006). Melatonin, as was described in the previous section, has many of the characteristics of a perfect candidate for the treatment of these kinds of illnesses.

  

Conclusion

Mitochondrial dyshomeostasis and related events have begun to reveal themselves as possible etiologies of several diseases of unknown origin. In the next years, conscientious investigation about this topic should be undertaken by scientists of different research areas to achieve a better understanding of the molecular mechanisms implied, which will ultimately allow the development and clinical application of efficacious treatments."

Recent posts looked at disturbed calcium homeostasis in autism, particularly low bone density.  Melatonin may play a role here as well.

     Melatonin Osteoporosis Prevention Study (MOPS)

Melatonin osteoporosis prevention study (MOPS): a randomized, double-blind, placebo-controlled study examining the effects of melatonin on bone health and quality of life in perimenopausal women.

Abstract

The purpose of this double-blind study was to assess the effects of nightly melatonin supplementation on bone health and quality of life in perimenopausal women. A total of 18 women (ages 45-54) were randomized to receive melatonin (3mg, p.o., n=13) or placebo (n=5) nightly for 6months. Bone density was measured by calcaneal ultrasound. Bone turnover marker (osteocalcin, OC for bone formation and NTX for bone resorption) levels were measured bimonthly in serum. Participants completed Menopause-Specific Quality of Life-Intervention (MENQOL) and Pittsburgh Sleep Quality Index (PSQI) questionnaires before and after treatment. Subjects also kept daily diaries recording menstrual cycling, well-being, and sleep patterns. The results from this study showed no significant change (6-month-baseline) in bone density, NTX, or OC between groups; however, the ratio of NTX:OC trended downward over time toward a ratio of 1:1 in the melatonin group. Melatonin had no effect on vasomotor, psychosocial, or sexual MENQOL domain scores; however, it did improve physical domain scores compared to placebo (mean change melatonin: -0.6 versus placebo: 0.1, P<0.05). Menstrual cycling was reduced in women taking melatonin (mean cycles melatonin: 4.3 versus placebo: 6.5, P<0.05), and days between cycles were longer (mean days melatonin: 51.2 versus placebo: 24.1, P<0.05). No differences in duration of menses occurred between groups. The overall PSQI score and average number of hours slept were similar between groups. These findings show that melatonin supplementation was well tolerated, improved physical symptoms associated with perimenopause, and may restore imbalances in bone remodeling to prevent bone loss. Further investigation is warranted.

           Melatonin Effects on Hard Tissues: Bone and Tooth

Melatonin, as an endogenous hormone, participates in many physiological and pharmacological processes. The above analyzed data indicate that melatonin may be involved in the development of the hard tissues bone and teeth. Decreased melatonin levels may be related to bone disease and abnormality. Due to its ability of regulating bone metabolism, enhancing bone formation, promoting osseointegration of dental plant and cell and tissue protection, melatonin may used as a novel mode of therapy for augmenting bone mass in bone diseases characterized by low bone mass and increased fragility, bone defect/fracture repair and dental implant surgery. The investigation of melatonin on tooth still insufficient and requires further research.

The following very interesting study, looking at the broader effects of high dose melatonin in autism, has been completed, but the results have yet to be published

Melatonin Dose-effect Relation in Childhood Autism (MELADOSE)

the objective of this clinical trial is to study the relation between the melatonin dose administered and its effect on severity of autistic impairments especially in verbal communication and play.

Experimental: 2 mg melatonin 1 tablet of 2mg melatonin and 4 tablets of its placebo once a day, an hour before falling asleep, for 6 weeks.
Experimental: 4 mg melatonin 2 tablets of 2mg melatonin and 3 tablets of its placebo once a day, an hour before falling asleep, for 6 weeks.
Experimental: 10 mg melatonin 5 tablets of 2mg melatonin once a day, an hour before falling asleep, for 6 weeks.

The science part

The following is an extract from an excellent paper about the use of melatonin to treat ulcerative colitis:-

Melaton in and Ulcerative Colitis: Evidence, Biological Mechanisms, and Future Research

Melatonin was first described as a secretion from the pineal gland with multiple neurohormonal functions, including regulation of the circadian rhythm, reproductive physiology, and body temperature, but has since also been found to inhibit the Cox-2 and NF-_B pathways and several aging processes. The multifactorial role of this hormone, however, has only relatively recently been appreciated (Fig. 1) as it circulates unimpeded across anatomical barriers, the blood– brain barrier included, and exhibits both receptor-dependent and receptor-independent effects.

Furthermore, melatonin exhibits a high degree of conservation across the evolutionary ladder, pointing to a critical function in various forms of life, even in organisms devoid of a pineal gland. In fact, the analysis of extrapineal sources of melatonin have highlighted the GI tract as a major source of this factor, with concentrations of melatonin as much as 100 times that found in blood and 400 times that found in the pineal gland.40 GI melatonin comes from both pineal melatonin and de novo synthesis in the GI tract and may have a direct effect on many GI tissues, serving as an endocrine, paracrine, or autocrine hormone, influencing the regeneration and function of epithelium, modulating the immune milieu in the gut, and reducing the tone of GI muscles by targeting smooth muscle cells.40 Melatonin may also influence the GI tract indirectly, through the central nervous system and the mucosa, by a receptor-independent scavenging of free radicals leading to reduction of inflammation, reduction of secretion

of hydrochloric acid, stimulation of the immune system, COX-2 fostering tissue repair and epithelial regeneration, and increasing microcirculation. Human intestinal motility follows a circadian rhythm with reduced nocturnal activity. Abnormalities in colonic motor function in patients with UC have been well documented.

Melatonin appears to be involved in the regulation of GI motility, exerting both excitatory and inhibitory effects on the smooth musculature of the gut.  The precise mechanism through which melatonin regulates GI motility is not clear, although some studies suggest that this may be related to blockade of nicotonic channels by melatonin and/or the interaction between melatonin and Ca2+ activated K channels.

Melatonin may also function as a physiological antagonist of serotonin. In a recent rodent model, melatonin administration was shown to reverse lipopolysaccharide-induced GI motility disturbances through the inhibition of oxidative stress. The net motor regulation by melatonin is, therefore, likely multifactorial.

In addition, several lines of in vitro studies as well as animal studies, have reported that melatonin regulates the extensive gut immune system and has important general antiinflammatory and immunomodulatory effects. Given its

presence in GI tissue and its suggested importance in GI tract physiology, it is reasonable to hypothesize that melatonin could influence inflammation-related GI disorders, including UC. In various animal experiments, melatonin administration was (among other immunomodulatory effects) shown to increase

IL-10 production and inhibit production of IFN-_, TNF-_, IL-6, and NO, suggesting that melatonin may exert benefits in UC by reducing or controlling inflammation.

Melatonin administration has also inhibited the TNF-_-induced mucosal addressin cell adhesion molecule (MAd-CAM)-1 in vitro, and intercellular adhesion molecule (ICAM)-1 in vivo, limiting the influx of activated _4_7_ and LFA-1_ leukocytes to the mucosal environment. During inflammation, the mucosal microvasculature controls the selection and magnitude of influx of T-cell subsets into the gut through cell adhesion molecules expression and chemokine secretion, which further amplify the communication with other leukocytes and cells. In animal experiments neutralization of MAdCAM-1 and ICAM-1 led to attenuation of mucosal damage in colitis.

If you made your way through the above section, and regularly read this blog you will appreciate the multiple possible beneficial actions for many types of autism.

I was going to have a post about GI issues, but I will put some of the melatonin part in this post.  In summary, very many GI problems are associated with low levels and melatonin and numerous studies have shown that giving oral melatonin is an effective treatment to varying degrees. Melatonin is a useful adjunct (add-on) therapy in these conditions. 

Not only does melatonin appears to promote healing of the esophagus but also the tightening of the LES (The lower esophagealsphincter)

Failure of this sphincter to close is why people get reflux/GERD/GORD.

One possibility is that the night time spike in melatonin signals your brain that it is time to sleep and also signals your LES to shut tightly, so that during the night acid does not rise up your esophagus while you are horizontal.

The potential therapeutic effect of melatonin in gastro-esophageal reflux disease

Regression of gastroesophageal reflux disease symptoms using dietary supplementation with melatonin, vitamins and aminoacids: comparison with omeprazole.   

Melatonin and Ulcerative Colitis:Evidence, Biological Mechanisms, and Future Research  

Oxidative Stress: An Essential Factor in the Pathogenesis of Gastrointestinal Mucosal Diseases

Which is the best choice for gastroesophageal disorders: Melatonin or proton pump inhibitors?

Conclusion

Melatonin may already be the most widely used drug to treat autism, but generally at the lower sleep-inducing doses.

It would seem that those with GI problems, mitochondrial problems or more general oxidative stress may very well benefit from the higher doses of melatonin already used by some.

Older people, people with esophagitis/duodenitis or IBS/IBD, people with type 1 or 2 diabetes and even people with osteoporosis may also want to look into melatonin supplementation.

Given the supplement is ending up in your intestines, where much melatonin should already be being produced, the impact on pineal melatonin production becomes less of an issue.  People giving thyroid hormones T3 and T4 to children who are euthyroid (ie normal thyroid function) should be aware of the consequences (thyroid shutdown).

For various reasons, production of ROS (reactive oxygen species) that are the oxidants varies throughout the day, the morning is the worst time supposedly.  Ideally you would match this with your antioxidant intake.  One combination would be melatonin before bed, a larger dose of NAC at breakfast and then NAC throughout the day.  As highlighted in an earlier post, sustained release NAC is also interesting, but it would help if there was a more potent version. 

Hopefully Dr Tordjman will publish the results of her high dose melatonin in autism study soon.

  

Most people struggle to access the really effective autism drugs, but antioxidants are available in abundance.

Oxidative stress is not a cause of autism, but it is a common side effect.  Treating oxidative stress does indeed seem to help many people with autism, but since the source of those oxidants may vary so should the most effective therapy.  Melatonin may be a useful part of that antioxidant mix, particularly if there are GI, mitochondrial or sleep issues.

Melatonin has a half-life of less than an hour, people who respond well might consider sustained release versions, which are available quite cheaply (5 and 10 mg sustained release forms look interesting).  There are even some clinical trials measuring the resulting plasma levels.