RAS signaling, Autism, Cancer and Gingerols

Sytrinol (Tangeretin), sacrificial Gummy Bear and Gingerol

Today’s post follows on from an earlier one that introduced the term RASopathy.  A RASopathy is a disease characterized by over-activation of the RAS protein.

RASopathies are of interest because if you have one, you are highly likely to also have autism.

RAS dysfunction is also present in many types of cancer and there are existing drugs to inhibit RAS signaling.  It has been claimed that:-

"If RAS proves to be a key player in autism …  it might suggest new treatments for autism, as many cancer drugs inhibit RAS signaling."

Regular readers of the Simons Foundation autism blog may have read the following:

RAS pathway, a potentially unifying theory of autism

  

Cancer pathway connects autism to set of rare disorders

If RAS proves to be a key player in autism, she says, it might suggest new treatments for autism, as many cancer drugs inhibit RAS signaling.

RAS-based interventions

My Polypill already has one RAS-based component, the statin.  This (the statin) is now being patented by the University of California.

Statins as Treatment for Cognitive Dysfunction Associated with RASopathies

Innovation

Professor Alcino Silva and colleagues at the UCLA department of Neurobiology have repurposed HMG-CoA reductase inhibitors (or statins) to reverse the cognitive dysfunction associated with RASopathies. By blocking HMG-CoA reductase, the drug prevents overactivation of the Ras protein, which leads to deficits in long term potentiation, a mechanism of learning and memory. Using in vivo models of NF1 and Noonan Syndrome, the researchers have shown that lovastatin is able to restore both LTP deficits and cognitive function to wild-type levels.

Applications

• Treatment of cognitive dysfunction associated with NF1

• Treatment of cognitive dysfunction associated with Noonan syndrome

• Treatment of other disorders driven by hyperactivation of the Ras-MAPK pathway

Advantages

• Statins would represent the first and only drug available to treat the cognitive defects observed in NF1, Noonan and other RASopathies
• Statins have already been approved by the FDA as a cholesterol-lowering drug, demonstrating an amenable safety profile in humans
• Effectiveness in restoring cognitive function has been demonstrated in vivo

  

The studies using Lovastatin were positive:-

Lovastatin as treatment for neurocognitive deficits in neurofibromatosistype 1: phase I study

Lovastatin regulates brain spontaneous low-frequency brain activity in neurofibromatosis type 1.

However in the following trial in the Netherlands, Simvastatin was shown not to be effective in NF-1.

Simvastatin for cognitive deficits and behavioural problems in patients with neurofibromatosis type 1 (NF1-SIMCODA): a randomised, placebo-controlled trial

The UCLA team seem to think Lovastatin has potential, even though Simvastatin appears not to.

There is a comprehensive presentation from Silvalab at UCLA below,

Mechanisms and Adult Treatments for Neurodevelopmental Disorders

It seems that in Rett Syndrome (not a RASopathy) statins may also help.

Statins Suppress Rett Syndrome Symptoms in Mice

So choose your statin with care. 

We use Atorvastatin.  It works; but it has various possible modes of action, one of which is RAS.  Another is upregulating PTEN.

Upregulating PTEN is good, but if used to excess it may lead to reduced insulin sensitivity and type 2 diabetes.

However, anti-oxidants, sulfurophane and PPAR gamma agonists (Gingerols, tangeretin) all increase insulin sensitivity so this tiny risk can be mitigated.  Verapamil protects beta cells (that produce insulin) from damage.

Statin MAX

I was interested in further increasing the RAS inhibition to see if there would be further cognitive or other improvement.  This is not possible via increasing the dose of statin, but it is possible by using Farnesyltransferase inhibitors, these are mainly anti-cancer research compounds, but one is the flavonoid Gingerol.

Ginger is another of those substances that has been used for centuries in traditional medicine. Gingerols are found in uncooked ginger.

Gingerols in “Medicine”

Fortunately ginger has many claimed medical benefits, ranging from arthritis to cancer prevention and treatment.  As a result standardized concentrated versions are widely available.

When it comes to my experiments, one problem has been the taste of the substance and the loss in bioavailability by having to open up/crush the various substances.

Swallowing Pills

Swallowing pills is not an option for some people, but in some cases you lose the effect of a drug if you remove the outer coating.  This is true with the drugs that lower the acidity of your stomach (Proton Pump Inhibitors).  They are designed to dissolve in the acidity of your intestines and not before.

Sytrinol ,the tangeretin flavonoid that is an attractive PPAR gamma inhibitor, is packed in a thick capsule, because the research shows this increases its bioavailability.  So me squeezing it out on a piece of toast will dilute its potency.  

Having obtained my high gingerol content potion, the first thing I did was to open the capsule and taste it.  Not nice at all.

Monty, aged 11 with ASD, has an elder brother who makes an enormous fuss on the very rare occasion he has to swallow a tablet.

Having overcome the usual autism problems of visiting a dentist and a hairdresser, the time had come for Monty to learn how to swallow pills.

In the end it was a non-event.

Having agreed that a gummy bear would be the reward and with the usual glass of water sitting beside it, the lesson began.  I put a NAC pill on my tongue and he put a Tangeretin capsule on his.

Before I could even suggest he drank some water, he had swallow the Tangeretin and bitten the head off the gummy bear.

This was swiftly followed by the rather odd smelling gingerol capsule.

So, rather unexpectedly, I can proceed with my gingerol investigation.

Gingerol may or may not be effective in our type of autism, but the research is highly promising in several other areas, some comorbid^* with autism.

·        Asthma^*

·        Ulcerative Colitis^*

·        Arthritis ^*

·        Alzheimer’s Disease

·        Cancer^*

No data suggests people with ASD are prone to Alzheimer’s, although some Alzheimer’s drugs do help some people with ASD.  It may just be that people with ASD do not make it to their eighties. 

Safety

Ginger is very widely used and I do not see any safety issues, just taste issues.

Asthma

Active Components of Ginger Potentiate b-Agonist–Induced Relaxation of Airway Smooth Muscle by Modulating Cytoskeletal Regulatory Proteins

Clinical Relevance

Natural herbal remedies, including ginger, have long been used to treat respiratory conditions. Many individuals with asthma use herbal therapies to self-treat their asthma symptoms; however, little is known regarding how these compounds work in the airway. In the current work, we show that 6-gingerol, 8-gingerol, and 6-shogaol potentiate b-agonist–induced relaxation of airway smooth muscle by inhibiting both phosphodiesterase 4D and phosphatidylinositol-specific phospholipase C, leading to downstream regulation of contractile proteins. These data suggest that natural compounds can work in combination with traditional asthma therapies to relieve asthma symptoms.

Ginger Compounds May Help Treat Asthma

Arthritis

Comparative Effects of Two Gingerol-Containing Zingiberofficinale Extracts on Experimental Rheumatoid Arthritis1

“In conclusion, these data document a very significant joint-protective effect of these ginger samples, and suggest that non-gingerol components are bioactive and can enhance the antiarthritic effects of the more widely studied gingerols.”

Arthritis. Some research shows that taking ginger can modestly reduce pain in some people with a form of arthritis called “osteoarthritis.” One study shows that taking a specific ginger extract (Zintona EC) 250 mg four times daily reduced arthritis pain in the knee after 3 months of treatment. Another study shows that using a different ginger extract (Eurovita Extract 77; EV ext-77), which combines a ginger with alpinia also reduces pain upon standing, pain after walking, and stiffness. Some research has compared ginger to medications such as ibuprofen. In one study, a specific ginger extract (Eurovita Extract 33; EV ext-33) did not work as well as taking ibuprofen 400 mg three times daily for reducing arthritis pain. But in another study, taking ginger extract 500 mg twice daily worked about as well as ibuprofen 400 mg three times daily for hip and knee pain related to arthritis. In another study, a specific ginger extract combined with glucosamine (Zinaxin glucosamine, EV ext-35) worked as well as the anti-inflamatory medication diclofenac slow release 100 mg daily plus glucosamine sulfate 1 gram daily. Research also suggests that massage therapy using an oil containing ginger and orange seems to reduce short-term stiffness and pain in people with knee pain.

Ulcerative Colitis

Pharmacological Activity of 6-Gingerolin Dextran Sulphate Sodium-induced Ulcerative Colitis in BALB/c Mice

Gingerols are phenolic compounds in ginger (Zingiber officinale), which have been reported to exhibit anti-inflammatory, antioxidant, and anticancer properties. The present study aimed at evaluating the possible pharmacologic activity of 6-gingerol in a mouse model of dextran sulphate sodium (DSS)-induced ulcerative colitis. Adult male mice were exposed to DSS in drinking water alone or co-treated with 6-gingerol orally at 50, 100, and 200 mg/kg for 7 days. Disease activity index, inflammatory mediators, oxidative stress indices, and histopathological examination of the colons were evaluated to monitor treatment-related effects of 6-gingerol in DSS-treated mice. Administration of 6-gingerol significantly reversed the DSS-mediated reduction in body weight, diarrhea, rectal bleeding, and colon shrinkage to near normal. Moreover, 6-gingerol significantly suppressed the circulating concentrations of interleukin-1β and tumor necrosis factor alpha and restored the colonic nitric oxide concentration and myeloperoxidase activity to normal in DSS-treated mice. 6-Gingerol efficiently prevented colonic oxidative damage by increasing the activities of antioxidant enzymes and glutathione content, decreasing the hydrogen peroxide and malondialdehyde levels, and ameliorated the colonic atrophy in DSS-treated mice. 6-Gingerol suppressed the induction of ulcerative colitis in mice via antioxidant and anti-inflammatory activities, and may thus represent a potential anticolitis drug candidate.

PPARγ

6-gingerol inhibits rosiglitazone-induced adipogenesis in 3T3-L1 adipocytes.

Abstract

We investigated the effects of 6-gingerol ((S)-5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-3-decanone) on the inhibition of rosiglitazone (RGZ)-induced adipogenesis in 3T3-L1 cells. The morphological changes were photographed based on staining lipid accumulation by Oil-Red O in RGZ (1 µmol/l)-treated 3T3-L1 cells without or with various concentrations of 6-gingerol on differentiation day 8. Quantitation of triglycerides content was performed in cells on day 8 after differentiation induction. Differentiated cells were lysed to detect mRNA and protein levels of adipocyte-specific transcription factors by real-time reverse transcription-polymerase chain reaction and Western blot analysis, respectively. 6-gingerol (50 µmol/l) effectively suppressed oil droplet accumulation and reduced the sizes of the droplets in RGZ-induced adipocyte differentiation in 3T3-L1 cells. The triglyceride accumulation induced by RGZ in differentiated 3T3-L1 cells was also reduced by 6-gingerol (50 µmol/l). Treatment of differentiated 3T3-L1 cells with 6-gingerol (50 µmol/l) antagonized RGZ-induced gene expression of peroxisome proliferator-activated receptor (PPAR)γ and CCAAT/enhancer-binding protein α. Additionally, the increased levels of mRNA and protein in adipocyte-specific fatty acid binding protein 4 and fatty acid synthase induced by RGZ in 3T3-L1 cells were decreased upon treatment with 6-gingerol. Our data suggests that 6-gingerol may be beneficial in obesity, by reducing adipogenesis partly through the down-regulating PPARγ activity.

6-Shogaol and 6-gingerol, the pungent of ginger, inhibit TNF-alpha mediated down regulation of adiponectin expression via different mechanisms in 3T3-L1adipocytes

ABSTRACT In this study, we demonstrated that the two ginger-derived components have a potent and unique pharmacological function in 3T3-L1 adipocytes via different mechanisms. Both pretreatment of 6-shogaol (6S) and 6-gingerol (6G) significantly inhibited the tumor necrosis factor-alpha (TNF-alpha) mediated downregulation of the adiponectin expression in 3T3-L1 adipocytes. Our study demonstrate that (1) 6S functions as a PPARgamma agonist with its inhibitory mechanism due to the PPARgamma transactivation, and (2) 6G is not a PPARgamma agonist, but it is an effective inhibitor of TNF-alpha induced c-Jun-NH(2)-terminal kinase signaling activation and thus, its inhibitory mechanism is due to this inhibitory effect.

Microglial Activation

Inhibitors of Microglial Neurotoxicity: Focus on

Natural Products

Abstract: Microglial cells play a dual role in the central nervous system as they have both neurotoxic and neuroprotective effects. Uncontrolled and excessive activation of microglia often contributes to inflammation-mediated neurodegeneration. Recently, much attention has been paid to therapeutic strategies aimed at inhibiting neurotoxic microglial activation.

Pharmacological inhibitors of microglial activation are emerging as a result of such endeavors. In this review, natural products-based inhibitors of microglial activation will be reviewed. Potential neuroprotective activity of these compounds will also be discussed.

Future works should focus on the discovery of novel drug targets that specifically mediate microglial neurotoxicity rather than neuroprotection. Development of new drugs based on these targets may require a better understanding of microglial biology and neuroinflammation at the molecular, cellular, and systems levels.

8. Gingerol from Zingiber officinale

Ginger, the rhizome of the plant Zingiber officinale, has a long history of medicinal use. In traditional oriental medicine, ginger has been used to treat a wide range of ailments including stomach aches, diarrhea, nausea, asthma, respiratory disorders, toothache, gingivitis, and arthritis [98-100]. Several studies have shown that ginger inhibits pro-inflammatory cytokines, including IL-1β, IL-2 , TNF-α, and interferon (IFN)-gamma [101]. Ginger also has been shown to decrease synthesis of pro-inflammatory prostaglandins and leukotrienes via inhibition of COX-2 and 5-lipoxygenase (5- LOX) enzymes, which are the targets for numerous anti-inflammatory pharmaceuticals.

Grzanna et al. tested the effects of a ginger extract on THP-1 monocytic cells to determine whether it can block the induction of pro-inflammatory cytokines in these cells stimulated with LPS. The results of this study suggest that the anti-inflammatory properties of the ginger extract may provide beneficial effects similar to those of currently used COX inhibitors [102].

Recently, Jung et al. reported that the hexane fraction of Zingiberis Rhizoma Crudus extract inhibits the production of nitric oxide and pro-inflammatory cytokines in LPS-stimulated BV-2 microglial cells via the NF-κB pathway [103]. The authors indicated that ginger hexane extract significantly inhibited the excessive production of NO, PGE2, TNF-α, and IL-1β in LPS-stimulated BV-2 cells. Ginger extract also attenuated the mRNA expressions and protein levels of iNOS, COX-2, and proinflammatory cytokines. The molecular mechanisms that underlie ginger hexane extract-mediated attenuation of neuroinflammation were related to the inhibition of the phosphorylation of three mitogen-activated protein kinases (MAPKs), extracellular signal-regulated kinases 1 and 2 (ERK1/2), p38 MAPK, and c-Jun N-terminal kinase (JNK), and the activation of NF-κB [103].

6-Gingerol (Figure 2B), one of the active ingredients of ginger, has been reported to impart ginger with its anti-inflammatory properties. The 6-gingerol inhibited the production of pro-inflammatory cytokines from LPS-stimulated macrophages, and inhibited COX-2 expression by blocking the activation of p38 MAP kinase and NF-κB in phorbol ester-stimulated mouse skin [104-105]. Data indicate that several doses of 6-gingerol selectively inhibit production of pro-inflammatory cytokines such as TNF-α, IL-1, and IL-12 by murine peritoneal macrophages in the presence of LPS stimulation.

The authors also revealed that 6-gingerol does not affect antigen presenting cell (APC) function or cell surface expression of MHC II and co-stimulatory molecules [105]. These remarkable beneficial properties of ginger and 6-gingerol and the lack of gastrointestinal and renal side effects distinguish it from other NSAIDS. Considering the broad spectrum of ginger’s anti-inflammatory actions and its safety record in clinical trials, it is likely to be a valuable dietary supplement in the treatment of neurodegenerative and neuroinflammatory diseases. However, the ability of gingerol to cross bloodbrain barrier has not yet been explicitly demonstrated and needs further investigation.

.

Alzheimer’s Disease

At least in rats, we know that Gingerol does cross the blood brain barrier.

Protective effects of ginger root extract on Alzheimer disease-induced behavioral dysfunction in rats.

Abstract

The aim of this study was to assess the ability of a traditional Chinese medicinal ginger root extract (GRE) to prevent behavioral dysfunction in the Alzheimer disease (AD) rat model. Rat AD models were established by an operation (OP) in which rats were treated with a one-time intra-cerebroventricuIar injection of amyloid β-protein (Aβ) and continuous gavage of aluminum chloride every day for 4 weeks. GRE was administered intra-gastrically to rats. After 35 days, learning and memory were assessed in all of the rats. Brain sections were processed for immunohistochemistry and Hematoxylin & Eosin (H&E) and Nissl staining. The latency to show significant memory deficits was shorter in the group that received OP with a high dose of GRE (HG)(OP+HG) than in the groups that received OP with a low or moderate dose of GRE (LG, MG)(OP+LG, OP+MG) (p<0.05). The expression of superoxide dismutase (SOD) and catalase (CAT) in the OP+MG and OP+LG groups was up-regulated compared to the OP+HG groups (p<0.05). The rats in the OP+HG groups had lower levels of nuclear factor-κB (NF-κB), interleukin-1β (IL-1β), and malondialdehyde (MDA) expression than the rats in the OP+MG and OP+LG groups (p<0.05). This experiment demonstrates that the administration of GRE reverses behavioral dysfunction and prevents AD-like symptoms in our rat model.

[6]-Gingerolattenuates β-amyloid-induced oxidative cell death via fortifying cellularantioxidant defense system

 Abstract

β-Amyloid (Aβ) is involved in the formation of senile plaques, the typical neuropathological marker for Alzheimer’s disease (AD) and has been reported to cause apoptosis in neurons via oxidative and/or nitrosative stress. In this study, we have investigated the neuroprotective effect and molecular mechanism of [6]-gingerol, a pungent ingredient of ginger against Αβ_25–35-induced oxidative and/or nitrosative cell death in SH-SY5Y cells. [6]-Gingerol pretreatment protected against Aβ_25–35-induced cytotoxicity and apoptotic cell death such as DNA fragmentation, disruption of mitochondrial membrane potential, elevated Bax/Bcl-2 ratio, and activation of caspase-3. To elucidate the neuroprotective mechanism of [6]-gingerol, we have examined Aβ_25–35-induced oxidative and/or nitrosative stress and cellular antioxidant defense system against them. [6]-Gingerol effectively suppressed Aβ_25–35-induced intracellular accumulation of reactive oxygen and/or nitrogen species and restored Aβ_25–35-depleted endogenous antioxidant glutathione levels. Furthermore, [6]-gingerol treatment up-regulated the mRNA and protein expression of antioxidant enzymes such as γ-glutamylcysteine ligase (GCL) and heme oxygenase-1 (HO-1), the rate limiting enzymes in the glutathione biosynthesis and the degradation of heme, respectively. The expression of aforementioned antioxidant enzymes seemed to be mediated by activation of NF-E2-related factor 2 (Nrf2). These results suggest that [6]-gingerol exhibits preventive and/or therapeutic potential for the management of AD via augmentation of antioxidant capacity.

Cancer

NAC interferes with some anti-cancer actions, be careful if self treating

6-Shogaol induces apoptosis in human colorectal carcinoma cells via ROS production, caspase activation, andGADD 153 expression

Abstract

Ginger, the rhizome of Zingiber officinale, is a traditional medicine with anti-inflammatory and anticarcinogenic properties. This study examined the growth inhibitory effects of the structurally related compounds 6-gingerol and 6-shogaol on human cancer cells. 6-Shogaol [1-(4-hydroxy-3-methoxyphenyl)-4-decen-3-one] inhibits the growth of human cancer cells and induces apoptosis in COLO 205 cells through modulation of mitochondrial functions regulated by reactive oxygen species (ROS). ROS generation occurs in the early stages of 6-shogaol-induced apoptosis, preceding cytochrome c release, caspase activation, and DNA fragmentation. Up-regulation of Bax, Fas, and FasL, as well as down-regulation of Bcl-2 and Bcl-X_L were observed in 6-shogaol-treated COLO 205 cells. N-acetylcysteine (NAC), but not by other antioxidants, suppress 6-shogaol-induced apoptosis. The growth arrest and DNA damage (GADD)-inducible transcription factor 153 (GADD153) mRNA and protein is markedly induced in a time- and concentration-dependent manner in response to 6-shogaol.

Comparative antioxidant and anti-inflammatory effects of [6]-gingerol, [8]-gingerol,[10]-gingerol and [6]-shogaol

Results

In the antioxidant activity assay, [6]-gingerol, [8]-gingerol, [10]-gingerol and [6]-shogaol exhibited substantial scavenging activities with IC₅₀ values of 26.3, 19.47, 10.47 and 8.05 μM against DPPH radical, IC₅₀ values of 4.05, 2.5, 1.68 and 0.85 μM against superoxide radical and IC₅₀ values of 4.62, 1.97, 1.35 and 0.72 μM against hydroxyl radical, respectively. The free radical scavenging activity of these compounds also enhanced with increasing concentration (P < 0.05). On the other hand, all the compounds at a concentration of 6 μM have significantly inhibited (P < 0.05) f-MLP-stimulated oxidative burst in PMN. In addition, production of inflammatory mediators (NO and PGE₂) has been inhibited significantly (P < 0.05) and dose-dependently.

Conclusions

6-Shogaol has exhibited the most potent antioxidant and anti-inflammatory properties which can be attributed to the presence of α,β-unsaturated ketone moiety. The carbon chain length has also played a significant role in making 10-gingerol as the most potent among all the gingerols. This study justifies the use of dry ginger in traditional systems of medicine.

Growth Inhibition of Human Non-Small Lung Cancer Cells H460 By Green Tea and Ginger Polyphenols

Conclusion: The study reports the antiproliferative and apoptosis-mediated cytotoxic effects of green tea and ginger polyphenolic extracts on human H460 cell line, indicating their promising chemopreventive effect against lung cancer.

Conclusion

Ginger certainly does look to be good for you, but it has to be uncooked, otherwise you lose those gingerols.

I expect in ten years’ time we will know whether RAS signaling does underlie the autism of a wider group of people than those with currently identified RASopathies.

If you are impatient to know the answer you have a few choices:-

·        Statins

·        Gingerols

·        Other farnesyltransferase inhibitors (FTIs), a class of experimental cancer drugs that target protein farnesyltransferase with the downstream effect of preventing the proper functioning of the Ras (protein), which is commonly abnormally active in cancer.

Gingerols and Statins (as Farnesyltransferase inhibitors) for RASopathies and Some Autism

Today’s post was driven by another attempt not to take a statin.

Statins are among the world’s most prescribed, and yet most maligned, drugs.  Hundreds of millions of people take a statin drug every day to lower their cholesterol, but a small, vocal minority complain about muscle pains, memory loss and even type 2 diabetes.

Since my Polypill is evidently a therapy, and not a cure, for autism, the odds are that it will be needed life-long.  Regardless of the apparent lack of side-effects, nobody should be taking drugs/supplements that are not really needed.  Atorvastatin (Lipitor/Sortis) is part of my Polypill for the type of autism affecting Monty, aged 11, with ASD.

Every time I stop the statin part of my Polypill therapy, I end up starting it again after only a one day break.  I notice all sorts of little behavioral changes that I really do not want to see.   

These changes involve loss of initiative, flexibility and motivation.  I really do not see how these would be measured in any existing behavioral assessment of autism.  These little changes make a big difference in daily life, so-called adaptive behavior.

In case you are wondering, the types of people with autism that I think might benefit from statins, have high cholesterol and some of the following:-

·        Non-verbal, or people who are slightly verbal, but choose not to speak

·        Poor ability to generalize skills already mastered in 1:1 therapy

·        Great difficulty in separating

·        Great difficulty in coping with change

As with some other elements of the Polypill, there are numerous reasons why statins could/should help in autism.  Today I found yet another one and an interesting non-drug alternative.

Why Statins?

I originally choose statins as a possible therapy, based on their ability to control pro-inflammatory cytokines (e.g. cytokine storms), and their known neuro-protective properties (e.g. reduce mortality after a traumatic brain injury).

I then noted they also affect some autism target genes, such as PTEN and BCL-2.

I did also note that statins were being researched to treat Neurofibromatosis, a single gene condition that is frequently comorbid with an “autism” diagnosis.

Today’s post is really about why statins should help in Neurofibromatosis and what else shares the same mechanism of action. 

Putting aside cytokines, PTEN and BCL-2, this new mechanism (excessive RAS/ERK signaling) might also be active in broader autism and Intellectual Disability / MR.

The other recent development was a study at UCLA that looked at a rare condition called Noonan Syndrome.  Noonan Syndrome and Neurofibromatosis are members of a group of conditions called RASopathies.

The RASopathies are developmental syndromes caused by mutations in genes that alter the Ras subfamily and Mitogen-activated protein kinases that control signal transduction.

Statins reverse learning disabilities caused by genetic disorder

Drawing upon Silva’s previous research on neurofibromatosis 1, another Ras-influenced disease, the UCLA team treated the mice with lovastatin, an FDA-approved statin drug currently in wide clinical use.

When adult mice with Noonan were treated with lovastatin in the UCLA study, the drop in Ras activity dramatically improved their memory and ability to remember objects and navigate mazes.

“We were amazed to see that statin treatment restored the adult animals’ cognitive functions to normal. Traditionally, science assumes that therapy needs to start in the fetal stage to be effective,” explained Silva. “Our research suggests that the leading gene mutation responsible for Noonan syndrome plays critical roles not only in fetal development, but also in how well the adult brain functions.”

According to Silva, UCLA’s approach could help the estimated 35 million Americans who struggle with learning disabilities

The paper itself:-

Mechanism and treatment for learning and memory deficits in mouse models of Noonan syndrome

RAS/ERK Inhibitors

For those of you more interested in the implications, rather than the science, here they are.

Known RAS inhibitors include:-

·        Statins, the popular cholesterol reducing drugs.  The “lipophilic” statins (Simvastatin, Lovastatin, Atorvastatin) can cross the blood brain barrier

·        Farnesyltransferase inhibitors, these are mainly anti-cancer research compounds, but one is the flavonoid Gingerol

Gingerol, is the active constituent of fresh ginger.  It is normally found as a pungent yellow oil, but also can form a low-melting crystalline solid.

Cooking ginger transforms gingerol into zingerone, which is less pungent and has a spicy-sweet aroma. When ginger is dried, gingerol undergoes a dehydration reaction forming shogaols, which are about twice as pungent as gingerol. This explains why dried ginger is more pungent than fresh ginger.

Ginger also contains 8-gingerol, 10-gingerol, and 12-gingerol.

Physiological effects

Gingerol seems to be effective in an animal model of rheumatoid arthritis.

Gingerol has been investigated for its effect on cancerous tumors in the bowel, breast tissue, ovaries, the pancreas, among other tissues, with positive results.

Neurofibromatosis, Behavioral dysfunction and RAS signaling

Neurofibromatosis Type 1: Modeling CNS Dysfunction

Neurofibromatosis type 1 (NF1) is the most common monogenic disorder in which individuals manifest CNS abnormalities. Affected individuals develop glial neoplasms (optic gliomas, malignant astrocytomas) and neuronal dysfunction (learning disabilities, attention deficits). Nf1 genetically engineered mouse models have revealed the molecular and cellular underpinnings of gliomagenesis, attention deficit, and learning problems with relevance to basic neurobiology. Using NF1 as a model system, these studies have revealed critical roles for the NF1 gene in non-neoplastic cells in the tumor microenvironment, the importance of brain region heterogeneity, novel mechanisms of glial growth regulation, the neurochemical bases for attention deficit and learning abnormalities, and new insights into neural stem cell function. Here we review recent studies, presented at a symposium at the 2012 Society for Neuroscience annual meeting, that highlight unexpected cell biology insights into RAS and cAMP pathway effects on neural progenitor signaling, neuronal function, and oligodendrocyte lineage differentiation.

Working memory, which, like attention, depends on intact prefrontal circuitry, is also impaired in both Nf1^+/− mice and in individuals with NF1. Functional imaging studies showed that the working memory impairments of NF1 subjects correlated with hypoactivation in the prefrontal cortex, which may reflect increased GABA-mediated inhibition in prefrontal cortical circuits of Nf1^+/− mice. Remarkably, a dose of a GABA receptor inhibitor (picrotoxin), which caused deficits in working memory in control mice, rescued the working memory deficits of Nf1^+/− mice, a result consistent with the hypothesis that increased inhibition is at the root of the working memory deficits associated with NF1.

Increases in RAS/ERK signaling in Nf1^+/− mice have been implicated in the working memory, attention, and spatial learning deficits of these mice. Genetic and pharmacological manipulations that target the RAS/ERK signaling pathway were shown to rescue the physiological and behavioral deficits of Nf1^+/− mice. Importantly, pharmacological manipulations that impair the isoprenylation of RAS (statins, farnesyl transferase inhibitors), and therefore decrease the levels of RAS/ERK signaling, also rescue key electrophysiological and behavioral phenotypes of Nf1^+/− mice. Indeed, at concentrations that do not affect signaling, physiology, or behavior of wild-type controls, statins reverse the signaling, electrophysiological, attention, and spatial learning deficits of Nf1^+/− mice. Prompted by these findings, clinical studies are currently underway to test the efficacy of statins as a treatment for the behavioral and cognitive deficits in individuals with NF1.

Similar to individuals with NF1, Nf1 mutant mice also show attention deficits. These deficits are thought to be key contributors to academic and social problems in children with NF1. Using an additional Nf1 GEM strain to study attention, in which the Nf1^+/− mutation is combined with Cre-driven homozygous Nf1 gene deletion in GFAP-expressing cells (Nf1 OPG mouse), it was found that reduced striatal dopamine was responsible for the observed attention deficits. Treatment with methylphenidate (but not with drugs that affect RAS) reversed the attention deficits of these Nf1 OPG mutants, suggesting that defects in brain catecholamine homeostasis contribute to the attention deficits observed. These results suggest that, in addition to drugs that affect RAS/ERK signaling, drugs that manipulate dopaminergic function could also be used to treat the cognitive deficits associated with NF1.

Treatments and future directions

With the availability of genetically engineered mouse models for NF1-associated CNS pathology, it now becomes possible to envision a pipeline in which fundamental basic science discoveries lead to the identification of new cellular and molecular targets for therapeutic drug design, culminating in preclinical evaluation before testing in patients with NF1. First, the success of Nf1 mouse model implementation has already resulted in the clinical evaluation of lovastatin in children with NF1-associated learning deficits and rapamycin analogs for the treatment of glioma. Second, mouse models afford an opportunity to envision specific features of NF1 as distinct diseases defined by the timing of NF1 gene inactivation or the particular cell of origin. Similar to other cancers, the identification of molecular or cellular subtypes of NF1-associated nervous system tumors or learning/behavioral problems may result in more individualized treatments with a higher likelihood of success. Third, as we further exploit these powerful preclinical models, additional cellular and molecular targets may emerge as candidates for future therapeutic drug design. In this regard, one could envision more effective therapies resulting from the combined use of targeted inhibition of multiple growth control pathways regulated by neurofibromin in the neoplastic cell (NF1-deficient neuroglial precursor) or dual targeting of non-neoplastic (microglia) and neoplastic cells within NF1-associated CNS tumors.

RASopathies & Autism

Autism traits in the RASopathies

Higher prevalence and severity of autism traits in RASopathies compared to unaffected siblings suggests that dysregulation of Ras/MAPK signalling during development may be implicated in ASD risk. Evidence for sex bias and potential sibling correlation suggests that autism traits in the RASopathies share characteristics with autism traits in the general population and clinical ASD population and can shed light on idiopathic ASDs.

This systematic study offers empirical support that autism traits are associated with developmental Ras/MAPK pathway dysregulation. It suggests that individuals affected by RASopathies should be evaluated for social communication challenges and offered treatment in these areas. This is the first strong evidence that multiple members of a well-defined biochemical pathway can contribute to autism traits. Future studies could explore potential modifying or epistatic factors contributing to variation within the RASopathies and the role of Ras/MAPK activation in idiopathic ASDs.

RAS/ERK Inhibitors

Inhibition of Ras for cancer treatment: the search continues

Discussion

Despite intensive effort, to date no effective anti-Ras strategies have successfully made it to the clinic. We present an overview of past and ongoing strategies to inhibit oncogenic Ras in cancer.

Conclusions

Since approaches to directly target mutant Ras have not been successful, most efforts have focused on indirect approaches to block Ras membrane association or downstream effector signaling. While inhibitors of effector signaling are currently under clinical evaluation, genome-wide unbiased genetic screens have identified novel directions for future anti-Ras drug discovery.

Conclusion

In some people with “autism” statins are an effective therapy.  Higher doses of statin are associated with side effects.  By knowing the principal mode of action of statins in autism, we might be able to develop a more potent therapy – STATIN PLUS.

On the basis of today’s post, investigating Farnesyltransferase inhibitors, as inhibitors of RAS signalling, looks an interesting option.

Gingerol is available as an inexpensive, supposedly standardized, product.  Ginger itself has been safely used in traditional medicine for thousands of years.

Perhaps Gingerol is the PLUS and for people unwilling to use a statin, perhaps Gingerol could be the statin?

The current medical view on ginger:-

According to the America Cancer Society

Recent preliminary results in animals show some effect in slowing or preventing tumor growth. While these results are not well understood, they deserve further study. Still, it is too early in the research process to say whether ginger will have the same effect in humans.

Anti-Oxidative and Anti-Inflammatory Effects of Ginger in Health and Physical Activity: Review of Current Evidence

  

Note on Intellectual Disability / MR

Regular readers may recall, I have commented that not only are many types of autism partially treatable, but so should be some types of Intellectual Disability / MR.  This same theme about treating cognitive dysfunction is raised in the paper below.

In the days when most readers of this blog were at school, 30-50% of people with an autism diagnosis were also diagnosed with Intellectual Disability / MR.  This is no longer the case; as autism diagnoses have skyrocketed in Western countries, diagnosis of Intellectual Disability / MR has not followed it.

People born today with what used to be called autism, often suffer from epilepsy and impaired cognitive function.  They do now tend to get rather sidelined by the much wider scope of the “autism” diagnosis used today, mainly in Anglo-Saxon countries (where most research is carried out).

The point where this matters is in clinical trials, since many of the milder autisms (now even being called “quirky autism”) may be caused by entirely different dysfunctions.  The observational diagnosis of “autism” is enough to enter most trials, but as we have seen in this blog, autism is not a true diagnosis; it is merely a description of symptoms.  It is like going to the doctor and saying “I think I might have a head ache” and after some questions, the doctors sits back and says “yes, you have a headache”.  You want to know why you have a head ache and how to make it go away.

Understanding Intellectual Disability through RASopathies

A fraction of the cases of intellectual disability is caused by point mutations or deletions in genes that encode for proteins of the RAS/MAP Kinase signaling pathway known as RASopathies. Here we examined the current understanding of the molecular mechanisms involved in this group of

genetic disorders focusing in studies which provide evidence that intellectual disability is potentially treatable and curable. The evidence presented supports the idea that with the appropriate understanding of the molecular mechanisms involved, intellectual disability could be treated pharmacologically and perhaps through specific mechanistic-based teaching strategies.