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Showing posts with label Angelman Syndrome. Show all posts
Showing posts with label Angelman Syndrome. Show all posts

Wednesday, 23 October 2019

GABAa receptor trafficking, Migraine, Pain, Light Sensitivity, Autophagy, Jacobsen Syndrome, Angelman Syndrome, GABARAP, TRPV1, PX-RICS, CaMKII and CGRP ... Oh and the "fever effect"



The mechanism controlling transporting just the “right” number of GABAA receptors


Today’s post is not for the faint-hearted.  It is another one that could just keep on rolling.  Ling will like it.

It again shows that GABAA receptors are at the centre of much autism, whether single gene or idiopathic. Today we highlight what can go wrong as these receptors are “transported”.

Today’s post also draws on several quite recent papers. It seeks to tie together some previous things mentioned in this blog like the symptoms of pain, particularly felt in the head, sensory sensitivity with dysfunction processes like autophagy and linking it all back to the GABAA receptor.  There is even a link at the end to the "fever effect", which occurs when a high temperature in some people causes a marked improvement in their autism symptoms.

We will come across some expensive drugs like Erenumab, the medical food PEA (Palmitoylethanolamide) and indeed Natasa’s favourite, CBD (Cannabidiol) and a newcomer CBDV (Cannabidivarin).   
We come across a protein called GABARAP (GABAA receptor associated protein) for the first time in this blog.  There is a vast amount in this blog about the GABAA receptor, how and why to modulate it. 

CaMKII makes an appearance, this is a protein kinase that is miss-regulated in much neurological disease. It changes the effect of many other proteins, acting just like a switch, by chemically adding phosphate groups to them. We have previously seen how important the protein kinases PKA, PKB and PKC are to autism.  Today add CaMKII to the list.

We come across another distinctive “face” of autism, this time it is Jacobsen syndrome, which I think is easily spotted by the trained eye, or some facial recognition software.  Jacobsen syndrome is a rare chromosomal disorder resulting from deletion of genes from chromosome 11 that includes band 11q24. This may include the gene that encodes the protein PX-RICS and, if so, it will lead to “autism”. Loss of that gene should be treatable with a GABA agonist.     

We also come back to that happy puppet syndrome (Angelman syndrome) which usually involves loss of the gene UBE3A, from chromosome 15. What I found interesting was that both Jacobsen syndrome and Angelman syndrome should share impaired GABAA receptor trafficking as a feature. They each have a different impediment that should reduce the number of functioning GABAA receptors. In the case of Angelman the impediment is CaMKII inhibition, in Jacobsen it is lack of the protein PX-RICS. Angelman syndrome may well respond to the same therapy as Jacobsen syndrome – a GABA agonist, of just a PAM (positive allosteric modulator, to “turn up the volume”).

Back to GABARAP

GABARAP has multiple functions:

1.     Transport of freshly minted GABAA receptors

In order for newly minted GABAA receptors to get to their final destination it requires four “helpers”: GABARAP, PX-RICS, 14-3-3 and Dynactin.  In addition, you need a dose of CaMKII. If you lack any one of these four, you will end up with reduced expression of GABAA receptors. If CaMKII is overactivated you get too many GABAA receptors.

In Jacobsen Syndrome there is reduced GABAA receptor trafficking/transport, leading to reduced surface expression. (in effect not enough functioning GABAA receptors in situ).  In some people with this syndrome the part of their DNA which encodes PX-RICS is missing.  This lack of PX-RICS produces autism.  The autism-like behavioural abnormalities in PX-RICS-deficient mice are ameliorated by enhancing inhibitory synaptic transmission with a GABAAR agonist.

2.     GABARAP modulates TRPV1 expression

GABARAP also does something totally different, it modulates TRPV1 ion channels, that we have previously touched on in this blog.  This then triggers a cascade of effects relating to pain, neuralgia, migraine headaches, microglial activation, epilepsy and indeed longevity.

The simple function of TRPV1 is detection and regulation of body temperature. In addition, TRPV1 provides a sensation of scalding heat and pain. TRPV1 is also known as the capsaicin receptor.  Capsaicin is the active component of chilli peppers.
TRPV1 not only plays a role in pain, but is suggested to play a role in migraine. In migraine TRPV1 plays a role along with calcitonin gene-related peptide receptor (CGRPR). TRPV1 determines how much of the CGRPR protein is produced. CGRPR affects your metabolism broadly and as such plays a key role in longevity.  Ablation of select pain sensory receptors (TRPV1) or the inhibition of CGRP are associated with increased metabolic health and longevity.
Erenumab/Aimovig is a medication which targets CGRPR for the prevention of migraine. It was the first of the group of CGRPR antagonists to be FDA approved in 2018. It is a form of monoclonal antibody therapy in which antibodies are used to block the receptors for the protein CGRP, thought to play a major role in starting migraines.
Recent evidence suggests that TRPV1 may contribute to the onset and progression of some forms of epilepsy;  Cannabidivarin  (CBDV) and cannabidiol (CBD), activate and desensitize TRPV1.
TRPV1 also plays a crucial role in the activation of microglia. As the researchers put it “TRPV1 channels are critical brain inflammation detectorsmicroglia shifted toward an anti-inflammatory phenotype when TRPV1 is lacking.

So, if we jump a few steps forward we can see that desensitizing TRPV1 might be helpful for people with: -

·        Some epilepsy
·        Some neuralgia
·        Perhaps some with chronic migraine
·        People with activated microglia, which is most autism

We also can see that a dysfunction in GABARAP may itself contribute to worsening the above conditions via its effect on TRPV1.


Epilepsy is the most common neurological disorder, with over 50 million people worldwide affected. Recent evidence suggests that the transient receptor potential cation channel subfamily member 1 (TRPV1) may contribute to the onset and progression of some forms of epilepsy. V Since the two nonpsychotropic cannabinoids cannabidivarin (CBDV) and cannabidiol (CBD) exert anticonvulsant activity in vivo and produce TRPV1-mediated intracellular calcium elevation in vitro, we evaluated the effects of these two compounds on TRPV1 channel activation and desensitization and in an in vitro model of epileptiform activity. Patch clamp analysis in transfected HEK293 cells demonstrated that CBD and CBDV dose-dependently activate and rapidly desensitize TRPV1, as well as TRP channels of subfamily V type 2 (TRPV2) and subfamily A type 1 (TRPA1). TRPV1 and TRPV2 transcripts were shown to be expressed in rat hippocampal tissue. When tested on epileptiform neuronal spike activity in hippocampal brain slices exposed to a Mg2+-free solution using multielectrode arrays (MEAs), CBDV reduced both epileptiform burst amplitude and duration. The prototypical TRPV1 agonist, capsaicin, produced similar, although not identical effects. Capsaicin, but not CBDV, effects on burst amplitude were reversed by IRTX, a selective TRPV1 antagonist. These data suggest that CBDV antiepileptiform effects in the Mg2+-free model are not uniquely mediated via activation of TRPV1. However, TRPV1 was strongly phosphorylated (and hence likely sensitized) in Mg2+-free solution-treated hippocampal tissue, and both capsaicin and CBDV caused TRPV1 dephosphorylation, consistent with TRPV1 desensitization. We propose that CBDV effects on TRP channels should be studied further in different in vitro and in vivo models of epilepsy.


TRPV1 channels are critical brain inflammation detectors and neuropathic pain biomarkers in mice

The capsaicin receptor TRPV1 has been widely characterized in the sensory system as a key component of pain and inflammation. A large amount of evidence shows that TRPV1 is also functional in the brain although its role is still debated. Here we report that TRPV1 is highly expressed in microglial cells rather than neurons of the anterior cingulate cortex and other brain areas. We found that stimulation of microglial TRPV1 controls cortical microglia activation per se and indirectly enhances glutamatergic transmission in neurons by promoting extracellular microglial microvesicles shedding. Conversely, in the cortex of mice suffering from neuropathic pain, TRPV1 is also present in neurons affecting their intrinsic electrical properties and synaptic strength. Altogether, these findings identify brain TRPV1 as potential detector of harmful stimuli and a key player of microglia to neuron communication.

TRPV1 controls cortical microglia activation

In the healthy mature brain, microglial cells play a role in immune surveillance and ensure the maintenance of brain homeostasis. Upon injuries these cells shift to an activated state characterized by drastic changes in the cellular shape, functional behavior and by the release of different proinflammatory and immunoregulatory factors58,59. Conforming to the capsaicin-mediated induction of microglial chemotaxis29, we investigated whether TRPV1 stimulation regulates the morphology of microglial cells…. Thus, stimulation of TRPV1 induced a pro-inflammatory phenotype of microglia from WTs. Conversely, microglia shifted toward an anti-inflammatory phenotype when TRPV1 is lacking.


Angelman syndrome

Angelman syndrome (Happy puppet syndrome) is a genetic disorder that mainly affects the nervous system. Symptoms include a small head and a specific facial appearance, severe intellectual disability, developmental disability, speaking problems, balance and movement problems, seizures, and sleep problems. Children usually have a happy personality and have a particular interest in water. The symptoms generally become noticeable by one year of age.  Angelman syndrome is typically due to a new mutation rather than one inherited from a person's parents. Angelman syndrome is due to a lack of function of part of chromosome 15 inherited from a person's mother. Most of the time, it is due to a deletion or mutation of the UBE3A gene.

CaMKII inhibition underlies Angelman Syndrome



CaMKII
CaMKII is a serine/threonine-specific protein kinase that is regulated by the Ca2+/calmodulin complex. CaMKII is involved in many signaling cascades and is thought to be an important mediator of learning and memory. CaMKII is also necessary for Ca2+ homeostasis and reuptake in cardiomyocytes, chloride transport in epithelia, positive T-cell selection, and CD8 T-cell activation.
Misregulation of CaMKII is linked to Alzheimer’s disease, Angelman syndrome, and heart arrhythmia.

Recent evidence for CaMKII dysregulation in psychiatric diseases is reviewed.
Changes in postsynaptic structure and function appear to be central to multiple diseases.
Altered regulation of the CaMKIIα gene promoter may be a common mechanism among diseases.
CaMKII dysregulation in diverse brain regions may account for myriad disorders.
Although it has been known for decades that hippocampal calcium/calmodulin (CaM)-dependent protein kinase II (CaMKII) plays an essential role in learning and memory consolidation, the roles of CaMKII in other brain regions are only recently being explored in depth. A series of recent studies suggest that CaMKII dysfunction throughout the brain may underlie myriad neuropsychiatric disorders, including drug addiction, schizophrenia, depression, epilepsy, and multiple neurodevelopmental disorders, perhaps through maladaptations in glutamate signaling and neuroplasticity. I review here the structure, function, subcellular localization, and expression patterns of CaMKII isoforms, as well as recent advances demonstrating that disturbances in these properties may contribute to psychiatric disorders.

A Novel Human CAMK2A Mutation Disrupts Dendritic Morphology and Synaptic Transmission, and Causes ASD-Related Behaviors


Characterizing the functional impact of novel mutations linked to autism spectrum disorder (ASD) provides a deeper mechanistic understanding of the underlying pathophysiological mechanisms. Here we show that a de novo Glu183 to Val (E183V) mutation in the CaMKIIα catalytic domain, identified in a proband diagnosed with ASD, decreases both CaMKIIα substrate phosphorylation and regulatory autophosphorylation, and that the mutated kinase acts in a dominant-negative manner to reduce CaMKIIα-WT autophosphorylation. The E183V mutation also reduces CaMKIIα binding to established ASD-linked proteins, such as Shank3 and subunits of l-type calcium channels and NMDA receptors, and increases CaMKIIα turnover in intact cells. In cultured neurons, the E183V mutation reduces CaMKIIα targeting to dendritic spines. Moreover, neuronal expression of CaMKIIα-E183V increases dendritic arborization and decreases both dendritic spine density and excitatory synaptic transmission. Mice with a knock-in CaMKIIα-E183V mutation have lower total forebrain CaMKIIα levels, with reduced targeting to synaptic subcellular fractions. The CaMKIIα-E183V mice also display aberrant behavioral phenotypes, including hyperactivity, social interaction deficits, and increased repetitive behaviors. Together, these data suggest that CaMKIIα plays a previously unappreciated role in ASD-related synaptic and behavioral phenotypes.
SIGNIFICANCE STATEMENT Many autism spectrum disorder (ASD)-linked mutations disrupt the function of synaptic proteins, but no single gene accounts for >1% of total ASD cases. The molecular networks and mechanisms that couple the primary deficits caused by these individual mutations to core behavioral symptoms of ASD remain poorly understood. Here, we provide the first characterization of a mutation in the gene encoding CaMKIIα linked to a specific neuropsychiatric disorder. Our findings demonstrate that this ASD-linked de novo CAMK2A mutation disrupts multiple CaMKII functions, induces synaptic deficits, and causes ASD-related behavioral alterations, providing novel insights into the synaptic mechanisms contributing to ASD.

Jacobsen Sydrome

The signs and symptoms of Jacobsen syndrome can vary. Most affected people have delayed development of motor skills and speech; cognitive impairment; and learning difficulties. Behavioral features have been reported and may include compulsive behavior; a short attention span; and distractibility. Many people with the condition are diagnosed with attention deficit-hyperactivity disorder (ADHD). The vast majority of people with Jacobsen syndrome also have a bleeding disorder called Paris-Trousseau syndrome, which causes abnormal bleeding and easy bruising. 

People with Jacobsen syndrome typically have distinctive facial features, which include small and low-set ears; wide-set eyes (hypertelorism) with droopy eyelids (ptosis); skin folds covering the inner corner of the eyes; a broad nasal bridge; down-turned corners of the mouth; a thin upper lip; and a small lower jaw (micrognathia). Affected people often have a large head (macrocephaly) and a skull abnormality called trigonocephaly, giving the forehead a pointed appearance.

The Autism-Related Protein PX-RICS Mediates GABAergic Synaptic Plasticity in Hippocampal Neurons and Emotional Learning in Mice


GABAergic dysfunction underlies many neurodevelopmental and psychiatric disorders. GABAergic synapses exhibit several forms of plasticity at both pre- and postsynaptic levels. NMDA receptor (NMDAR)–dependent inhibitory long-term potentiation (iLTP) at GABAergic postsynapses requires an increase in surface GABAARs through promoted exocytosis; however, the regulatory mechanisms and the neuropathological significance remain unclear. Here we report that the autism-related protein PX-RICS is involved in GABAAR transport driven during NMDAR–dependent GABAergic iLTP. Chemically induced iLTP elicited a rapid increase in surface GABAARs in wild-type mouse hippocampal neurons, but not in PX-RICS/RICS–deficient neurons. This increase in surface GABAARs required the PX-RICS/GABARAP/14–3-3 complex, as revealed by gene knockdown and rescue studies. iLTP induced CaMKII–dependent phosphorylation of PX-RICS to promote PX-RICS–14-3-3 assembly. Notably, PX-RICS/RICS–deficient mice showed impaired amygdala–dependent fear learning, which was ameliorated by potentiating GABAergic activity with clonazepam. Our results suggest that PX-RICS–mediated GABAAR trafficking is a key target for GABAergic plasticity and its dysfunction leads to atypical emotional processing underlying autism.

There is a growing consensus that autism arises from the atypical regulation of the excitation/inhibition balance within specific neural microcircuitry. In terms of neural inhibition, autism is closely related to dysfunctional inhibitory signaling mediated by the γ-aminobutyric acid (GABA) type A receptors (GABAARs). Impaired presynaptic release of GABA and postsynaptic trafficking of GABAARs lead to autistic-like social behavior in mouse models of autism. There is a significant reduction in the number of GABAARs and GABAergic activity in certain brain areas of autistic individuals. Genetic association studies have revealed that several GABAAR subunits are linked to an increased risk for autism. GABAAR–mediated signaling is thus essential for the proper regulation of the excitation/inhibition balance associated with socio-emotional cognition.

PX-RICS, GABARAP and 14-3-3ζ/θ are localized in the specific dendritic compartments that are immunopositive for organelle markers for the endoplasmic reticulum (ER), ER exit sites and the trans-Golgi network. This structure, termed the dendritic satellite secretory pathway, is comprised of the dendritic ER and the Golgi outposts and is involved in the local synthesis, processing and transport of membrane-integral or secretory proteins in dendrites. The rapid increase in surface-expressed GABAARs after NMDA stimulation could be explained by the localization of the PX-RICS–dependent trafficking machinery in the dendritic secretory compartments.
Several lines of evidence suggest that the dysregulation of GABA signaling underlies atypical social behavior in autism However, there has been no report describing deficits in GABAergic plasticity that contribute to autistic features. The present study has shown that PX-RICS is essential for GABAergic iLTP and that loss of the PX-RICS function in mice leads to impaired cued fear learning. Cued fear learning is closely associated with GABAAR–mediated activity and plasticity in the amygdala and is inversely correlated with the severity of autistic symptoms. Considering all of these findings, we thus reason that PX-RICS–dependent GABAAR transport may play critical roles in emotional learning in the amygdala through the control of GABAergic synaptic plasticity and that the impairment of this transport mechanism may lead to improper socio-emotional processing, resulting in autistic-like atypical social behavior (Supplementary Fig. 7). Further elucidation of the functional link between GABAergic plasticity and socio-emotional learning could lead to a better understanding of autism pathogenesis and treatment. 
We have previously identified and characterized two splicing isoforms of GTPase-activating proteins specific for Cdc42 predominantly expressed in neurons of the cerebral cortex, amygdala and hippocampus: RICS (ARHGAP32 isoform 2) and PX-RICS (ARHGAP32 isoform 1) . RICS regulates NMDAR–mediated signaling at the postsynaptic density and axonal elongation at the growth cone. In contrast, PX-RICS forms an adaptor complex with GABARAP and 14-3-3ζ/θ to facilitate steady-state trafficking of the N-cadherin/β-catenin complex and GABAARs. PX-RICS is also responsible for autistic-like features observed in more than half of the patients with Jacobsen syndrome (JBS) [3]. Mice lacking PX-RICS/RICS show marked decreases in surface-expressed GABAARs and GABAAR–mediated inhibitory synaptic transmission, resulting in various autistic-like behaviors and autism-related comorbidities. Rare single-nucleotide variations in PX-RICS are also linked to non-syndromic autism, schizophrenia and alexithymia. These findings strongly suggest that dysfunction of PX-RICS–mediated GABAAR trafficking has severe effects on socio-emotional processing of the brain.
Our previous study described above showed that PX-RICS and other components of the GABAAR trafficking complex are required for constitutive transport of the receptor. In this study, we have focused on the role of PX-RICS in the activity–induced promotion of GABAAR trafficking during iLTP. Here we show that PX-RICS–mediated GABAAR trafficking is also involved in NMDAR activity–dependent trafficking of GABAARs and that PX-RICS is a key target of CaMKII for regulating GABAergic synaptic plasticity. Furthermore, we show that PX-RICS dysfunction in mice leads to impaired amygdala–dependent emotional learning, which manifests as autistic-like social behavior [3].




Supplementary Fig. 7. PX-RICS–mediated GABAAR trafficking underlies NMDAR–dependent GABAergic iLTP PX-RICS, GABARAP and 14-3-3s are assembled to form an adaptor complex that interconnects γ2-containing GABAARs (cargo) and dynein/dynactin (motor). Interaction
of PX-RICS with 14-3-3s depends on the phosphorylation activity of CaMKII, and this interaction is a critical regulatory point for GABAAR trafficking. When CaMKII activity is at a basal level, the PX-RICS–mediated trafficking complex has a role in steady-state transport of GABAARs to maintain the number of surface GABAARs as needed for proper synaptic inhibition.3 Neural activity that evokes moderate Ca2+ influx through NMDAR preferentially increases the activated form of CaMKII and elicits its translocation to inhibitory synapses, where it phosphorylates target proteins such as gephyrin and the GABAAR β3 subunit. Phosphorylated gephyrin and the GABAAR β3 subunit regulate the surface dynamics of GABAARs such as lateral diffusion and synaptic confinement. The present study has revealed that PXRICS
is a downstream CaMKII target associated with anterograde transport of
GABAARs. Enhanced PX-RICS phosphorylation increases the PX-RICS–14-3-3 complex and thereby drives de novo GABAAR surface expression, resulting in GABAergic iLTP. Dysfunction of this trafficking mechanism in the amygdala causes impaired GABAergic synaptic plasticity, which may contribute to deficits in socioemotional behavior as observed in PX-RICS/RICS–deficient mice and JBS patients with autism.


PX-RICS-deficient mice mimic autism spectrum disorder in Jacobsen syndrome through impaired GABAA receptor trafficking


Jacobsen syndrome (JBS) is a rare congenital disorder caused by a terminal deletion of the long arm of chromosome 11. A subset of patients exhibit social behavioural problems that meet the diagnostic criteria for autism spectrum disorder (ASD); however, the underlying molecular pathogenesis remains poorly understood. PX-RICS is located in the chromosomal region commonly deleted in JBS patients with autistic-like behaviour. Here we report that PX-RICS-deficient mice exhibit ASD-like social behaviours and ASD-related comorbidities. PX-RICS-deficient neurons show reduced surface γ-aminobutyric acid type A receptor (GABAAR) levels and impaired GABAAR-mediated synaptic transmission. PX-RICS, GABARAP and 14-3-3ζ/θ form an adaptor complex that interconnects GABAAR and dynein/dynactin, thereby facilitating GABAAR surface expression. ASD-like behavioural abnormalities in PX-RICS-deficient mice are ameliorated by enhancing inhibitory synaptic transmission with a GABAAR agonist. Our findings demonstrate a critical role of PX-RICS in cognition and suggest a causal link between PX-RICS deletion and ASD-like behaviour in JBS patients.


TRPV1

We now come back to TRPV1, which we saw is modulated by GABARAP.

GABAA receptor associated protein (GABARAP) modulates TRPV1 expression and channel function and desensitization


Transient receptor potential vanilloid (TRPV1) transduces noxious chemical and physical stimuli in high-threshold nociceptors. The pivotal role of TRPV1 in the physiopathology of pain transduction has thrust the identification and characterization of interacting partners that modulate its cellular function. Here, we report that TRPV1 associates with γ-amino butyric acid A-type (GABAA) receptor associated protein (GABARAP) in HEK293 cells and in neurons from dorsal root ganglia coexpressing both proteins. At variance with controls, GABARAP augmented TRPV1 expression in cotransfected cells and stimulated surface receptor clustering. Functionally, GABARAP expression attenuated voltage and capsaicin sensitivity of TRPV1 in the presence of extracellular calcium. Furthermore, the presence of the anchor protein GABARAP notably lengthened the kinetics of vanilloid-induced tachyphylaxia. Notably, the presence of GABARAP selectively increased the interaction of tubulin with the C-terminal domain of TRPV1. Disruption of tubulin cytoskeleton with nocodazole reduced capsaicin-evoked currents in cells expressing TRPV1 and GABARAP, without affecting the kinetics of vanilloid-induced desensitization. Taken together, these findings indicate that GABARAP is an important component of the TRPV1 signaling complex that contributes to increase the channel expression, to traffic and cluster it on the plasma membrane, and to modulate its functional activity at the level of channel gating and desensitization.

‘Entourage’ effectsof N‐palmitoylethanolamide and N‐oleoylethanolamide on vasorelaxation to anandamide occur through TRPV1 receptors



Age-Dependent Anti-seizure and Neuroprotective Effect of Cannabidivarin in Neonatal Rats


Neonatal seizures and seizures of infancy represent a significant cause of morbidity. 30–40% of infants and children with seizures will fail to achieve seizure remission with current anti-epileptic drug (AED) treatment. Moreover, pharmacotherapy during critical periods of brain development can adversely affect nervous system function. We, and others, have shown that early life exposure to AEDs including phenobarbital, phenytoin, and valproate are associated with induction of enhanced neuronal apoptosis during a confined period of postnatal development in rats. Thus, identification of new therapies for neonatal/infantile epilepsy syndromes that provide seizure control without neuronal toxicity is a high priority.
Current clinical trials report that modulation of the cannabinoid system with the phytocannabinoid cannabidiol exerts anti-seizure effects in children with epilepsy. While cannabidiol and the propyl analog cannabidivarin (CBDV) display anti-seizure efficacy in adult animal models of seizures/epilepsy, they remained unexplored in neonatal models. Therefore, we investigated the therapeutic potential of CBDV in multiple neonatal rodent seizure models. To evaluate the therapeutic potential of CBDV, we tested its anti-seizure efficacy in five models of neonatal seizures: pentylenetetrazole (PTZ), DMCM, hypoxia, kainate and NMDA-evoked spasms, each representing a different clinical seizure phenotype. We also evaluated the preclinical safety profile in the developing brain.
Postnatal day (P) 10 or P20 male, Sprague-Dawley rat pups were pretreated with CBDV or vehicle prior to chemically or hypoxia induced seizures. CBDV only displayed anticonvulsant effects in the P20 rat pups in the PTZ and DMCM models, with no effect on seizure severity or latency in the P10 animals. Therefore, we next measured the relative expression of known targets for CBDV (TRPV1, TRPA1) to determine a mechanism for which CBDV is anticonvulsant in P20, but not P10 animals. The P20 animals show increased expression of TRPV1 in key brain regions implicated in epileptogenic activity.
Together, these results indicate that modulation of the cannabinoid system in a receptor independent manner can provide seizure control in developing animals, but in an age specific manner. Further, during a developmentally sensitive neonatal period, drugs targeting the cannabinoid system do not induce neuronal apoptosis characteristic of many other AEDs. These results provide some of the first systemic, preclinical data evaluating CBDV in pediatric models of epilepsy.


Weight-based dosing of 10 mg/kg/day of CBDV for 12 weeks
Primary Outcome Measures  :
1.     Aberrant Behavior Checklist-Irritability Subscale (ABC-I) [ Time Frame: Change in ABC-I from Baseline to Week 12 (Change over 12 weeks) ]
Change in ABC-I from Baseline to Endpoint


  

Lack of Autophagy will reduce the number of GABAA receptors, by blocking GABARAP function

Regular readers will recall that one feature of autism and many other neurological diseases is a reduction in autophagy, which I likened to an intra-cellular garbage collection service. 

The very recent paper below shows that lack of autophagy blocks GABARAP from its job to transport freshly minted GABAA receptors.
If correct, this actually has very wide implications.



The disruption of MTOR-regulated macroautophagy/autophagy was previously shown to cause autistic-like abnormalities; however, the underlying molecular defects remained largely unresolved. In a recent study, we demonstrated that autophagy deficiency induced by conditional Atg7 deletion in either forebrain GABAergic inhibitory or excitatory neurons leads to a similar set of autistic-like behavioral abnormalities even when induced following the peak period of synaptic pruning during postnatal neurodevelopment. Our proteomic analysis and molecular dissection further revealed a mechanism in which the GABAA receptor trafficking function of GABARAP (gamma-aminobutyric acid receptor associated protein) family proteins was compromised as they became sequestered by SQSTM1/p62-positive aggregates formed due to autophagy deficiency. Our discovery of autophagy as a link between MTOR and GABA signaling may have implications not limited to neurodevelopmental and neuropsychiatric disorders, but could potentially be involved in other human pathologies such as cancer and diabetes in which both pathways are implicated.


Conclusion

You may have skipped to the conclusion to avoid all the science.

The conclusion is simple, you need to keep your GABAA receptors in tip top form if you want to avoid the symptoms of autism.

o   You need the right number of them
o   You need the right balance among the five constituent subunits
o   You need the correct level of chloride inside neurons so the receptors are not “working backwards”

All of the genes that encode proteins involved in the above are individually “autism genes”, because any one of them can disrupt the process.

Whether it is Dravet syndrome (GABAA receptor α2 subunit), Angelman syndrome, Jacobsen syndrome, Down syndrome or numerous other autism syndromes, not to mention idiopathic autism, check the above 3 bullet points.

Tune up/down your GABAA receptors!

Desensitizing TRPV1 looks interesting and not just for epilepsy.  TRPV1 appears to be essential for microglia in the in brain to be activated.  We know that in autism microglia in the brain are permanently activated, as if there was a threat.

I do think there is cross-talk (feedback loops etc) going on here, for example you can treat the severe epilepsy in Dravet syndrome by any of the following:-

·        KBr, to lower intracellular chloride
·        Low dose clonazepam to affect α subunits of GABAA receptors
·        CBD or CBDV to modify TRPV1


Note that Dravet syndrome is caused by a mutation in the gene that encodes the sodium ion channel Nav1.1, the dysfunction of GABAA receptors is a secondary effect. Also of interest is that the seizures that occur in Dravet syndrome are often triggered by hot temperatures or fever, so you can see how TRPV1 is indeed likely involved.  More generally in idiopathic autism, we have the "fever effect" when high temperatures trigger a reduction in autistic behaviors, making it the opposite of Dravet syndrome. 

On the one hand the biology behind the various problems may look horribly complicated and interwoven, the solutions appear to be much simpler and you have multiple options.

I await the results of the autism clinical trial of CBDV (Cannabidivarin) with interest.

Just impaired autophagy may lead to a reduction in GABAA receptors and the appearance of autistic features in an otherwise “normal” brain. This reminds us again of why autism is not a medical diagnosis, it is just a vague/subjective observation, which, in severe cases, should then trigger a thorough medical investigation.









Thursday, 14 February 2019

More Politics of Autism, the NCSA, Prader Willi, Happy Puppets and the Crazy Car Wash


Kempton Park Racecourse, near London - now known for its Hot Dogs

A science-heavy post about microglia is in the works, but today’s post ties together some less complex issues.
As I mentioned in an earlier post, there is a new book out called the Politics of Autism, by Dr Siegel.
I did buy 2 copies, so I could give one away. It is a bit heavy going and I did skip some parts, but it is as expected a good read. The author does personally know/knew some of the “big names” in autism like Lovaas and even Bernie Rimland.
I was interested to read that Lovaas basically cheated in his famous ABA “clinical” trial, where he showed amazing responses. All the trial participants that did not develop speech during the trial were “retired” during the trial. He rigged the result, by removing those less responsive to the trial therapy.  If you follow this subject, you will know that some Americans and Canadians get very upset when intensive ABA is not provided for free to their child, believing that it would likely "cure" their child, like in the Lovaas study. This trial is constantly used to support the idea of intensive early intervention producing dramatic life changing results.  In most people with severe autism, no amount of behavioural intervention is going to change the fact that they are severely autistic. It does though make many such people more functional, which can greatly help them. Expectations need to be realistic and parents should not feel guilty if they cannot provide many years of therapy costing $60,000 a year. You can achieve a great deal at much less cost.
Siegel thinks that Bernie Rimland (of ARI and DAN!) started out well and then went a bit dotty.
She makes excellent points about education.
She makes the mistake of venturing into the realm of medicine, which is clearly not her field and tells readers not to bother trying to treat the biology autism. 10 years ago I would have been mistakenly backing her up on this, but then I had my epiphany, thanks to reading about Professor Ben Ari’s small clinical trial of Bumetanide in 2012.

Who should buy the book?
This is not a feel good book, it is a very down to earth book that tells the story as it is, not the sugar coated version.

I thought this book would be good for people who study autism at University, like one of Monty’s assistants; she now has copy number two.
Many people with Asperger’s would likely hate this book and think Dr Siegel is a witch.

I thought most parents of people with severe autism probably do not want to hear more about how bad things are, but perhaps I was wrong. Dr Siegel provided one of her old posts as a guest blog post for the newly formed National Council on Severe Autism (NCSA).

The NCSA is a new group set up to represent what used to be autism, before the diagnosis got broadened. They are really all about DSM3 autism, or what we called Strictly Defined Autism (SDA).



Horror stories or just telling it how it is?
Some people with mild autism seem to be very upset by what NCSA are advocating, but that is hardly a surprise.

Decide for yourself whether you consider the NCSA to be spreading horror stories, or just telling it how it is.
An attention-seeking UK daytime TV “celebrity” has a son with Prader Willi syndrome and he is regularly described as having autism.  Prader Willi is associated with an insatiable appetite which, if uncontrolled, leads to obesity; reduced IQ, impaired vision, behavioural problems and a bad temper. It is caused by an anomaly on chromosome 15, which causes a loss of function of some of those 600 genes.

75% of cases occur when part of the father's chromosome 15 is deleted.  In another 25% of cases, the person has two copies of chromosome 15 from their mother and none from their father. As parts of the chromosome from the mother are turned off, they end up with no working copies of certain genes
A similar mechanism occurs in Angelman syndrome, except the defective chromosome 15 is from the mother or two copies are from the father.


People with Angelman’s have small heads and are not obese; because they are generally very happy, they are sometimes called Angels.  The condition used to be called Happy Puppet Syndrome, which apparently is not seen as politically correct these days. I should add the Prader Willi could be called “please lock the fridge syndrome”, because if you do not remove food the child may become severely obese before he/she is 10, develop type 2 diabetes, rapidly become insulin dependent and then have even bigger problems.
The Prader Willi mother is campaigning for disabled people’s rights, which is of course a nice thing to do; she is against abuse/trolling on the internet.  She recently revealed that at 16 years of age, her verbal, but obese son cannot wash or dress himself and no longer attends school regularly, because he has learnt that by having an early morning meltdown, the driver will refuse to take him to school. Like many teenage boys he would rather stay home than go to school.

The mother says she is concerned he is missing out on schooling.
I dare say Dr Siegel would ask what kind of schooling is this 16 year old getting? Perhaps learning to wash himself and dress should first be mastered.  In someone without severe MR/ID this is a matter of correct instruction and unlimited perseverance, by someone.

Dr Siegel could repurpose her blog post again, this time:

Diagnose and adios? Prader Willi families deserve better

The mother says she is thinking of putting her son into residential care. That sounds great, but who is then ever going to teach him to wash and dress himself and restrict his eating? If Mum cannot, why would some employee earning near minimum wage in a care home make a better job of it? What happens when he starts to need insulin injections twice a day, because obesity was not addressed?
Sometimes horror stories do not reflect the child, but how they are being cared for and all with the best intentions.  Most such parents need help, indeed it’s to be expected. This all could be solved by some home visits from someone like Dr Siegel.  More of these people do exist; our Greek-American ABA consultant would give very similar advice to Dr Siegel. Avoiding school would not be tolerated, regardless of any meltdown. Someone with an IQ>60 definitely can be taught to dress himself, even if occasionally a shirt goes on back to front.  Food has to be restricted.

Monty's morning assistant at school works with many other kids with autism and from what she tells me, it is clear that many issues repeat, even the publicity-hungry mother who ends up failing her own child. Since our morning assistant is writing a self-help manual for parents dealing with severe autism, I can imagine where my other copy of Dr Siegel's book is destined to go. At least my autism intervention library is being put to further use.
It should be noted that some autism mothers react very dynamically. We have one reader who identified a novel effective drug therapy for her child and is now trying to commercialise it, we have another reader who has inspired and funded research into what was a rarely studied genetic "autism". Parents react very differently to the challenge of raising a child with a severe disability, in some it brings out the best.  It is not just about having a high IQ, or a lot of money.
Some people cannot afford to pay for such 1:1 advice, but many might choose to, if they knew it existed. In many countries, like some provinces in Canada, families dealing with a disability are given substantial financial resources to help themselves. In Ontario there is currently uproar on the proposed $140,000 cap on free autism therapies per child. That is $140,000 more free money that we received. I recently calculated our total cost of autism up to the age of 16 and when converted into Canadian money it is $190,000. They should of course have different limits based on different levels of severity. In the DSM5 jargon you have 3 levels of need/severity and so you could have a low limit for level 1, since Aspies do not benefit from vast amounts of ABA, say $20,000 and a high limit for level 3, say $250,000. Then wait for the surge in (re)diagnosis of level 3 autism in Ontario.

            Diagnosing for Dollars (click, for Dr Siegel's take)
Many “horror stories” appearing on the NCSA forums likely could be avoided by applying personalized medicine, rather than cookie cutter medicine, or standard psychiatric medicine. 

Kids with undiagnosed genetic disorders 
I am not a doctor, but I do quite regularly get to play guess the undiagnosed metabolic/genetic disorder.  The latest one is what would cause deafness and hypertonia and apparently no other symptoms.

I recently read that US medical insurance generally will not pay for genetic testing for autism, because there are no therapies.
But yet there sometimes are, if you look.

Look at the recent comments in this blog about a child whose genetic testing revealed a problem with the KCNQ3 gene, which encodes the Kv7.3 potassium ion channel. You can look up Kv7.3 channelopathy, or just the KCNQ3 gene.
This is at least partially treatable just by using google and the excellent Genecards human gene database; both cost absolutely nothing.


You can both activate and block this ion channel.  You will need one or the other.


Jobs for adults with Autism
You do quite regularly hear about how an IT company like Microsoft, or a big bank is actively recruiting people with autism. This always makes me laugh.  IT jobs for Aspies - yes of course, but autism?

People with DSM3 autism are not commuting to work reading the Wall Street Journal, or the Financial Times; but there should be things they can do.
Many years ago there used to be special companies set up to employ disabled people. This became not politically correct, for some reason.

Remploy is an organisation in the United Kingdom which provides employment placement services for disabled people. It is now a “welfare-to-work provider” finding jobs for disabled people, but for most its existence it directly employed disabled people in a number of factories, owned by Remploy itself, and subsidised by the UK government.  This was phased out at the start of the 21st century, under the prevailing view that disabled people should have mainstream jobs.

Sadly, many disabled people cannot hold down a mainstream job.

You might recall Andreas Rett (of Rett Syndrome), as well as being a doctor, established a factory in which neurologically disabled youngsters could work. That was 50 years ago.

One supermarket chain where we live sometimes has young people with Down Syndrome, or MR/ID helping to pack your groceries.

Monty’s afternoon assistant was telling me how sad it is that one Aspie her age is still without any job. My reply was that someone has to create him a job, just like we will have to create Monty a job.
I am a big believer in developing musical and other artistic skills, it did not get the above Aspie a job, but it does give him something to do.

Our very worldly Greek-American ABA consultant told me long ago that the biggest problem “her kids” face, as they grow up, is that they have nothing to do with all their time.  No job and no hobbies is not a good combination.
As I write this text, Monty is downstairs drawing a frog. Before that he was playing all the melodies in his current piano book.  Before that he washed his Mum’s car and earlier on we were washing my car.

Monty’s Crazy Car Wash
You gotta be a little bit Crazy to work here!
You gotta be totally Crazy not to try it!

I think Monty will end up more capable than having a car wash, but it is quite a suitable job for many young people with DSM3 autism. It is a genuine job, whereas packing groceries is not and the Crazy Car Wash is a lot of fun.

Good journalism?
There are very few journalists who are credible when they write about autism; they generally do not understand it at all (you cannot blame them for that!); then there are some Aspie ones, who will by definition tend to lack empathy, and they can completely fail to understand the severe end of the spectrum, often in a jaw-dropping fashion.

I rather liked this article by a 28 year old journalist taking charge of her 24 year old sister with autism, for the first time and going for a girls’ weekend riding horses.


I wonder at what point my 18 year son will be taking charge of his 15 year old sibling with autism, for a boys’ weekend. Hopefully I will not need to wait 10 years.
I expect it will be something eventful like Tom Cruise and Dustin Hoffman on a road trip to Las Vegas, in the excellent, but nowadays much maligned, film Rain Man. Bernie Rimland was the autism advisor for this film. 

This Christmas in London on December 26th, Monty asked me if he was going to be having a hot dog for lunch; leaving me to ponder where did that idea come from. He accurately recalled that 12 months previously, on Boxing Day, he had gone with Uncle Stuart and Dad to Kempton Park for a boys’ day out at the horse races. The weather is usually cold and damp (i.e. miserable), but you do get to have a hot dog.


Conclusion
If you can take the sometimes brutal honesty of describing things as they really are, then Dr Siegel’s new book is going to be appreciated and you will also like the new US National Council on Severe Autism. 

A sense of humour will do you much more good than political correctness ever will. Upsetting people can sometimes be necessary to enable them to acknowledge their own delusions. I am beginning to sound like Dr Siegel, who likely would take her car to the Crazy Car Wash, should Monty open a branch in California.
It is up to parents to stop their child becoming obese, even more so when they have a genetic propensity towards this condition. 

If you do not have $60,000 a year to pay for ABA and feel you are missing out, make your own intervention program instead. Buy some books and recruit some helpers.  Don't spend years fuming in a waiting list, pondering what might have been.










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