Selenium Protects a Specific Type of Interneurons in The Brain
Exactly 200 years ago, the Swedish scientist Jöns Jacob Berzelius discovered the trace element selenium, which he named after the goddess of the moon, Selene. Besides its industrial applications (chemical industry, production of semiconductors and toners), selenium is an essential trace element and indispensable for humans, many animals and some bacteria. A team led by Dr. Marcus Conrad, research group leader at the Institute of Developmental Genetics (IDG) at Helmholtz Zentrum München, showed for the first time why selenium is a limiting factor for mammals.
Scientific ‘by-catch’ solves decades-old mystery
The scientists have been investigating for years the processes of a novel type of cell death, known as ferroptosis. In this context, the enzyme GPX4, which normally contains selenium in the form of the amino acid selenocysteine, plays an important role.
In order to better understand the role of GPX4 in this death process, we established and studied mouse models in which the enzyme was modified,” said study leader Conrad. “In one of these models, we observed that mice with a replacement of selenium to sulfur in GPX4 did not survive for longer than three weeks due to neurological complications.”
In their search for the underlying reasons, the researchers identified a distinct subpopulation of specialized neurons in the brain, which were absent when selenium-containing GPX4 was lacking. “In further studies, we were able to show that these neurons were lost during postnatal development, when sulfur- instead of selenium-containing GPX4 was present,” stated first author of the study, Irina Ingold.
Furthermore, the scientists were able to show that ferroptosis is triggered by oxidative stress, which is known to occur for instance during high metabolic activity of cells and high neuronal activity. “Our study demonstrates for the first time that selenium is an essential factor for the postnatal development of a specific type of interneurons,” said Dr. José Pedro Friedmann Angeli, a scientist at the IDG, describing the results. “Selenium-containing GPX4 protects these specialized neurons from oxidative stress and from ferroptotic cell death.”
Thus, the study explains why certain selenoenzymes are essential in some organisms, including mammals, whereas they are dispensable in other organisms, such as fungi and higher plants. In future investigations, study leader Marcus Conrad and his team aim to investigate how ferroptosis is triggered in cells. As a long-term goal, he wants to elucidate the role of ferroptosis in various disease conditions in order to be able to alleviate diseases, such as cancer or neurodegeneration, which are currently difficult to tackle.
Journal Reference:
Irina Ingold, Carsten Berndt, Sabine Schmitt, Sebastian Doll, Gereon Poschmann, Katalin Buday, Antonella Roveri, Xiaoxiao Peng, Florencio Porto Freitas, Tobias Seibt, Lisa Mehr, Michaela Aichler, Axel Walch, Daniel Lamp, Martin Jastroch, Sayuri Miyamoto, Wolfgang Wurst, Fulvio Ursini, Elias S.J. Arnér, Noelia Fradejas-Villar, Ulrich Schweizer, Hans Zischka, José Pedro Friedmann Angeli, Marcus Conrad. Selenium Utilization by GPX4 Is Required to Prevent Hydroperoxide-Induced Ferroptosis. Cell, 2017; DOI: 10.1016/j.cell.2017.11.048
Story Source:
Materials provided by Helmholtz Zentrum München – German Research Center for Environmental Health.
This important nutrient is vital to immune system function. Selenium works in conjunction with vitamin E, vitamin C, glutathione and vitamin B3 as an antioxidant to prevent free radical damage in the body. It’s thought to help prevent cancer by affecting oxidative stress, inflammation and DNA repair. Selenium has been found to be important to male fertility; increasing selenium levels leads to improved sperm motility. There is preliminary research that suggests that selenium supplementation may also help with asthma symptoms, but more studies are needed.
Selenium Deficiencies
Deficiencies of selenium can occur in areas where soil content of this mineral is low. Diets high in refined foods may also lead to deficiency, as selenium can be destroyed by food processing. Taking anti-inflammatory drugs may reduce the body’s supply of selenium.
Low selenium levels can contribute to autoimmune problems, such as psoriasis and thyroid disease. Low levels have also been tied to stomach, throat and prostate cancers, although more research is needed to determine if this is a cause or a result of the disease. Some studies suggest that selenium deficiency is linked to mood disorders. There’s indication that deficiencies in selenium may contribute to the progression of viral infections.
10 Selenium Food Sources
The selenium content in foods depends on the concentration of selenium in the soil where the crops were grown. The following foods are generally considered good sources of selenium:
Exceeding 400 mcg per day can lead to selenium toxicity. Side effects may include hair loss, white spots on fingernails, fatigue, dizziness, nausea and nerve damage. There’s some evidence that high selenium levels may increase the risk of squamous cell skin cancer. Another well controlled study found a correlation between higher levels of selenium and an increased risk of developing type-2 diabetes.
Because of the possibility of toxicity, selenium supplements are controversial. The safest way to ensure a sufficient level of selenium in the diet is by eating a variety of selenium rich foods, like those listed above. Brazil nuts can be very high in selenium and should only be eaten occasionally. One Brazil nut can supply a whole day’s requirement of selenium, although this can vary depending on soil conditions. A multivitamin that contains some selenium is safe for most people to take and can help to fill the gap in a diet that is lacking.
When Garrett Pohlman was diagnosed with strep throat in 2007, his illness didn’t respond to antibiotics. Then the strange behaviors began.
Diana Pohlman says her son, who was 7 years old at the time, had been easygoing up to that point. But he developed severe obsessive compulsive disorder (OCD) symptoms overnight. He became paranoid – worrying about things like radiation from the TV and light switches. He had tics and anorexia and started having frequent episodes of rage.
“He was not anyone I recognized. He was a completely different child,” she says. “It was a nightmare. At first I thought maybe he had been molested. Then I thought he had a brain tumor.
“He became so delusional he would climb on the roof thinking it was the front door. He would jump in front of cars and out of moving cars, and he had self-harm fantasies. He was afraid to leave the house. We had to pick him up and wrap him in a sheet to get him out of the house. At the age of 7,” Pohlman says.
He was not anyone I recognized.
He was a completely different child.
Diana Pohlman
The search for answers was long and expensive. After many months, the family found their way to a psychiatrist who knew about a disorder called pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections, or PANDAS, a condition she says several specialists didn’t know about. That led to medical treatment that included long-term antibiotics, having his tonsils and adenoids removed, and eventually two rounds of immunoglobulin, or IVIG treatments.
Recovery was slow, but after 2 years, by the age of 9, Pohlman says the severe symptoms stopped. For another 2 years, he had what she calls mild and manageable symptoms that eventually dissipated.
But rather than move on from PANDAS, the boy’s mother decided she needed to help other parents trying to figure out these mysterious symptoms. She founded the nonprofit PANDAS Network in 2009 to raise awareness, support families, and push for more research to better understand how to diagnose and treat the condition.
“When I realized doctors didn’t understand it, I thought I better not quit working on this because how will anyone else ever get help,” Pohlman explains. “It is abysmal. It has been shocking how misinformed doctors are about the term ‘PANDAS.’ ”
Little is known about how or why the syndrome happens, and not all doctors believe there is a connection. The American Academy of Pediatrics does not recognize a link between strep and the syndrome.
“You will not find consensus from pediatric infectious disease doctors that PANDAS even exists, much less what to do about it and how to manage the patients,” says Meg Fisher, MD, a pediatrician and infectious disease specialist at Unterberg Children’s Hospital at Monmouth Medical Center in Long Branch, NJ. “We still haven’t had the definitive article or study or demonstration to really get some solid clinical evidence behind this. My problem is, even if you believe in the syndrome, it’s totally unclear what you should do to help those patients. All of the information is anecdotal.”
What Is PANDAS/PANS?
Susan E. Swedo, MD, at the National Institute of Mental Health (NIMH), first identified PANDAS in the 1990s after she reported on a link between the fast onset of OCD and group A streptococcus, more commonly known as strep.
You will not find consensus from pediatric infectious disease doctors that PANDAS even exists, much less what to do about it and how to manage the patients.
Meg Fisher, MD, Unterberg Children’s Hospital, Monmouth Medical Center
PANDAS happens when strep triggers a misdirected immune response that causes inflammation in a child’s brain. Pediatric acute-onset neuropsychiatric syndrome, or PANS, is a larger umbrella term that has to do with cases with a trigger other than strep, including infections like walking pneumonia or the flu.
Both disorders appear in childhood, typically between the ages of 3 and 12. While blood tests may help identify infections, there are no lab tests or other indicators for PANDAS or PANS.
Doctors diagnose the syndrome when children suddenly get severe OCD or eat a lot less food, along with at least two of the following symptoms: anxiety, depression, irritability or aggression, behavioral regression, ADD- or ADHD-like symptoms affecting schoolwork, sensory or motor problems, troubled sleep, and frequent urination.
The PANDAS Network says in some cases, the emotional symptoms can weaken children and make them homebound. Other children are OK at school but fall apart at home. The NIMH describes the start of symptoms as “dramatic,” happening “overnight and out of the blue.”
“The consensus of scientists and clinicians is that it needs to be sudden and severe,” says Margo Thienemann, MD, co-director of the PANS program at Stanford University Medical Center in California. “Sudden can be overnight. Some people can say exactly what time it started or that it happened over a couple of days. But they all say this isn’t their child anymore. Even if they don’t believe someone can be possessed, it feels that way. What happened? Why are they doing these things? Why can’t they stop?”
Swedo estimates that it impacts about 1% of elementary school-aged children and is likely under-diagnosed. The PANDAS Network estimates 1 in 200 children have it. Thienemann says her program at Stanford has seen more than 250 patients since it started in 2012. But she says that since their staff is small, they have to narrow down who gets in. One year, they turned away 1,000 patients because they couldn’t handle any more.
Thienemann says this is why they have helped write guidelines to allow health care providers to identify and treat these children. “It takes a multidisciplinary team to manage. A psychiatrist, pediatrician, or rheumatologist can’t do it alone. You need all these different vantage points to diagnose and coordinate care,” she says.
There are now PANS centers in California and Arizona, and some doctors around the country treat the disorder.
The NIMH says research suggests IVIG can ease symptoms and may be used in severe PANDAS cases, but it warns it has many side effects — including nausea, vomiting, headaches, and dizziness — and there is a chance of infection with this sort of procedure. Parents say it is also expensive and often not covered by insurance.
Some families say they also see improvement when they have their children’s tonsils and adenoids removed, although no studies show that works.
streptococcus pneumonia bacteria
Controversy
Not all in the medical community agree that strep or other infections can trigger these kinds of behaviors. There is also much debate about whether treatments are effective.
While the American Academy of Pediatrics does not recognize a link between strep and PANDAS, a March 2017 article in AAP News, sent to the group’s 66,000 pediatrician members, discusses the disorders and the controversy around them. While it’s not the group’s official policy, the article says pediatricians should consider PANS anytime a child “has an abrupt behavior change with obsessive thoughts,” and it points them to material that shows them how to diagnose it.
Fisher says it’s complicated for pediatricians, since there is no evidence that taking out tonsils and adenoids is helpful or that antibiotics work. She says many pediatricians worry that young patients will become resistant to antibiotics if you prescribe them long-term, and many have concerns about IVIG side effects.
“I understand the parents’ frustration, because finding a physician for these patients is very difficult. There are a lot of doctors who are, quote unquote, PANDAS specialists, but there is nothing that is evidence-based about what they are doing,” she says. “Our goal is first do no harm, and it is hard to know how best to help these patients. It is a very frustrating thing. I wish someone would come up with some solutions.”
Thienemann says most parents who find their way to her program are frantic because they can’t get help anywhere else. “Part of that desperation is nobody would listen to them. People say my pediatrician won’t do anything, and my child is trying to jump out of moving cars or a window. They can’t get out of the house, can’t sleep, are urinating on themselves, and have severe separation anxiety,” she says.
There is something medically wrong. There isn’t a finger to be pointed. There are questions to be asked and answered.
Ali Claypoole
Parents say it is obvious something isn’t right.
“I thought she had schizophrenia or severe mental illness,” says Kelly, a mother in Maryland who asked that we not use her last name to protect the privacy of her 7-year-old daughter, Maggie, who has PANDAS. “It was rapid-onset OCD, and then we were spending our entire life trying to keep her from jumping out of cars, hurting herself, biting us, and losing her mind.”
“There is something medically wrong. There isn’t a finger to be pointed. There are questions to be asked and answered,” adds Ali Claypoole, whose son, now 9 years old, first showed PANDAS symptoms at the age of 6. “Our world is turned upside down, and from where I am, it’s almost like parents are more informed than the doctors. I find the civilian community is much more understanding, interested, and willing to learn about this than the medical community. It makes me mad.”
Going Forward
More research is now being done.
In a 2017 large-scale study of key parts of the PANDAS theory, researchers looked at 17 years of data out of Denmark and found that young patients with a positive strep test had higher chances of having of mental disorders, especially OCD and tic disorders, compared with those without a positive strep test. Non-strep throat infections also carried a higher chance of these types of mental disorders in children, although it was less – perhaps pointing to the chance that other infections can trigger the symptoms.
It is really the brain inflammation
that is central to this disease.
Dritan Agalliu, PhD, Columbia University Medical Center
In 2016, Dritan Agalliu, PhD, an assistant professor in the Department of Neurology at Columbia University Medical Center in New York City, published a study showing that immune cells produced in the nose after multiple strep infections appear to be the culprit for the disease. These cells enter the brain via the nerves that are responsible for the sense of smell, and they damage the blood vessels and synapses in the brain.
Agalliu says this research helped explain a crucial step in the disease: how antibodies that the body makes to attack strep or other infections cross the blood/brain barrier in these children and attack parts of their brain by mistake; similar to what happens in other autoimmune diseases of the brain, like multiple sclerosis.
The NIHM recently awarded Agalliu nearly $2 million to keep studying the disorder. He says it should be called post-streptococcal basal ganglia encephalitis, or inflammation of the brain. He’s also doing research funded by a private donor, looking at genetic chances of having the disorders to understand why a small number of children who get multiple strep infections are prone to get the disease.
“It is really the brain inflammation that is central to this disease. If we think about PANDAS/PANS this way, it will relieve a lot of controversy and make therapies more acceptable for patients,” Agalliu says. “I am hoping with our next publication, we can alleviate any potential question that this is an autoimmune disease.”
There’s also increasing interest in looking at PANDAS as a type of Sydenham chorea, defined by abnormal movements, OCD, mood swings, and other emotional symptoms that follow strep infection.
The NIMH now has a group for PANDAS and PANS. The PANDAS Network is working to make information about the disorders part of continuing medical education for pediatricians, and a working group has created handouts to educate school personnel nationwide to help children with these disorders get back to their classrooms.
So will children outgrow PANDAS? Like most other things associated with this disorder, there is no consensus.
Doctors who focus on the disorders say when patients can get to them, improvement is possible. “If we get people as early as possible, maybe even at the onset of illness, I think we do a good job of being able to tamp down inflammation and help them a lot and maybe get them all the way better,” Thienemann says. “If someone has been dealing with it for 10 years, I think they may develop ongoing autoimmune problems and there may be damage to their brain. Recovery might not be as complete, but I think we can still help them.”
Three years after he first showed symptoms, Claypoole’s son had a full remission at the age of 9 after IVIG treatments. But after a few months, he got strep again and the PANDAS symptoms returned, but they were less severe. Kelly’s daughter Maggie has seen her symptoms subside for a while, only to return. Her doctors prescribe antibiotics and anti-inflammatories after each new episode. She takes both medications daily for months on end. She has also had two rounds of IVIG. “Every time we do an intervention, the baseline gets better, but it doesn’t end the problem. She is not symptom-free,” Kelly says.
Pohlman says her son, now 17, is a straight-A student who plays football and the cello and is applying to college. He is symptom-free.
“Once I understood that Garrett’s brain was on fire from an infectious illness, I barely could believe his body would have the capacity for a full recovery,” she says. “Could he have the normal life I had expected for my child? So I look at him now in amazement.”
By Jennifer Clopton Nov. 10, 2017 WebMD Article Reviewed by Hansa D. Bhargava, MD on November 10, 2017
Sources Ali Claypoole, Maryland. Kelly, Maryland. (Requested not using last name) Dritan Agalliu, PhD, Columbia University Medical Center, New York City. Meg Fisher, MD, Unterberg Children’s Hospital at Monmouth Medical Center, Long Branch, NJ. Diana Pohlman, executive director, PANDAS Network, Stanford, CA. Patricia Rice Doran, EdD, associate professor, Department of Special Education, Towson University, Maryland. Margo Thienemann, MD, Stanford University School of Medicine, Stanford, CA. AAP News: “PANDAS/PANS treatments, awareness evolve, but some experts skeptical.” American Academy of Pediatrics Red Book: “Group A Streptococcal Infections.” National Institute of Mental Health: “PANDAS, Questions and Answers.” National Institute of Mental Health: “Guidelines published for treating PANS/PANDAS.” PANDASNetwork.org: “What is PANS?” “What is PANDAS?” Symptoms,” “Statistics,” “Our Mission.” K. Chang, Journal of Child and Adolescent Psychopharmacology, Feb. 1, 2015. R. Kurlan, Pediatrics, June 2008. S Orlovska, JAMA Psychiatry, July 1, 2017. K.A. Williams, Brain Research, August 18, 2015. T Dileepan, The Journal of Clinical Investigation, January 4, 2016.
Around 30% of people are thought to carry the parasite often caught from a common domestic pet.
People with impulsive anger problems could have a parasite in their brain, a new study suggests.
Those who continually display behaviours like road-rage could be infected with a common parasite rather than having a psychological disorder.
Around 30% of people are thought to carry the toxoplasma gondii parasite — it is often present in, and caught from, cat faeces.
Professor Emil Coccaro, who led the research said:
“Our work suggests that latent infection with the toxoplasma gondii parasite may change brain chemistry in a fashion that increases the risk of aggressive behavior.
However, we do not know if this relationship is causal, and not everyone that tests positive for toxoplasmosis will have aggression issues.”
The conclusions come from a study of 358 adults.
The results showed that people with ‘intermittent explosive disorder’ (that’s rage issues to you and me!) were twice as likely to test positive for the toxoplasma gondii parasite in comparison to a healthy control group (22% versus 9%).
Across all the people in the study, those who tested positive for the toxoplasma gondii parasite had significantly higher levels of aggression and anger.
Dr Royce Lee, a study co-author, said:
“Correlation is not causation, and this is definitely not a sign that people should get rid of their cats.
We don’t yet understand the mechanisms involved–it could be an increased inflammatory response, direct brain modulation by the parasite, or even reverse causation where aggressive individuals tend to have more cats or eat more undercooked meat.
Our study signals the need for more research and more evidence in humans.
Professor Coccaro said:
“It will take experimental studies to see if treating a latent toxoplasmosis infection with medication reduces aggressiveness.
If we can learn more, it could provide rational to treat IED in toxoplasmosis-positive patients by first treating the latent infection.”
The study was published in the Journal of Clinical Psychiatry (Coccaro et al., 2016).
People in the study were asked to journal about their most stressful experiences.
Accepting negative emotions is the best way to deal with them in the long-run, new research finds.
People who are more accepting of their darker moods have better psychological health.
Dr Iris Mauss, one author of the study, said:
“We found that people who habitually accept their negative emotions experience fewer negative emotions, which adds up to better psychological health.”
Psychologists are still not sure exactly why acceptance is so powerful, said Dr Mauss:
“Maybe if you have an accepting attitude toward negative emotions, you’re not giving them as much attention.
And perhaps, if you’re constantly judging your emotions, the negativity can pile up.”
The results come from research on over 1,300 people.
Those who most strongly resisted negative emotions, or judged them excessively, were more stressed.
Over six months, the people who did best were those who let their dark moods run their course, with little judgement or criticism.
They had fewer symptoms of mood disorders like depression.
Dr Brett Ford, the study’s first author, said:
“It turns out that how we approaach our own negative emotional reactions is really important for our overall well-being.
People who accept these emotions without judging or trying to change them are able to cope with their stress more successfully.”
The researchers ruled out being richer as a factor, Dr Mauss said:
“It’s easier to have an accepting attitude if you lead a pampered life, which is why we ruled out socio-economic status and major life stressors that could bias the results.”
People were asked to journal about their most stressful experiences, in one of three studies the researchers conducted.
In general, those who did not feel bad about feeling bad had the highest levels of well-being and psychological health.
Next, the researchers want to look at where the habitual acceptance of negative emotions comes from.
Dr Mauss said:
“By asking parents about their attitudes about their children’s emotions, we may be able to predict how their children feel about their emotions, and how that might affect their children’s mental health.”
The study was published in the Journal of Personality and Social Psychology (Ford et al., 2017).
New research finds that cognitive behavioral therapy (CBT) actually changes key brain structures that are involved in processing and regulating emotions.
The finding helps to explain the success of CBT for anxiety disorders. Remediation of social anxiety is an important accomplishment as anxiety in social situations is not a rare problem.
Experts say that around one in 10 people are affected by social anxiety disorder during their lifetime. Social anxiety disorder is diagnosed if fears and anxiety in social situations significantly impair everyday life and cause intense suffering. A relatively common anxiety provoking experience is talking in front of a larger group — a situation that can provoke fear and extreme stress.
In the new study, researchers from the University of Zurich, Zurich University Hospital and the University Hospital of Psychiatry Zurich discovered that the successful treatment of an anxiety disorder alters key brain structures linked to emotions.
In patients suffering from social anxiety disorder, regulation of excessive anxiety by frontal and lateral brain areas is impaired. Strategies aimed at regulating emotions should restore the balance between cortical and subcortical brain areas.
These strategies are practiced in CBT, a central therapy for social anxiety disorder. In cognitive behavioral group therapy, patients learn and apply new strategies aimed at dealing with social anxiety disorder.
Based on specific examples, the group discusses explanatory models and identifies starting points for changes. Through self-observation, role plays, or video recordings, alternative viewpoints can be developed.
In the study, published online in the journal Molecular Psychiatry, researchers investigated structural brain changes in patients suffering from social anxiety disorder after a specific 10-week course of CBT. Using magnetic resonance imaging, the participants’ brains were examined before and after CBT.
“We were able to show that structural changes occur in brain areas linked to self-control and emotion regulation,” said Dr. Annette Brühl, head physician at the Center for Depression, Anxiety Disorders and Psychotherapy at the University Hospital of Psychiatry Zurich (PUK).
The more successful the treatment, the stronger the brain changes. The research group was also able to demonstrate that brain areas involved in processing emotions were more interconnected after the treatment.
“Psychotherapy normalizes brain changes associated with social anxiety disorder,” Brühl said.
Misophonia is most-likely a neurological affliction that causes a fight/flight/freeze response to otherwise normal visual and audial stimuli. As of now, there is no official consensus on what exactly causes the disorder. Though it was coined in 2001 by Jastreboff and Jastreboff there has been little research published under the disorder’s current name.
Researchers such as Joseph E. LeDoux and Stephen Porges have been researching auditory over-responsivity. However, the name of the disorder matters little since researchers are more focused on what’s going on inside the brain and body and not merely perceived notions and sweeping generalizations.
Many that sufferer from misophonia struggle with similar symptoms. Commonly, tapping, whistling, chewing, and other repetitive sounds cause this severe reaction. Though the disorder manifests with aversions to sights and sounds, many are proposing that its cause is physiological and not psychological.
There are currently no experts on Misophonia and no one doctor or researcher can claim that they have all the answers. This is also true of treatments and coping methods. Before trying a treatment please ensure that you are aware that new disorders not only carry a lack of treatment but also a risk. If you are trying experimental treatments please be wary. If you feel uncomfortable with your treatment provider, do not hesitate to refrain from continuing.
Please chew with your mouth CLOSED!
As of now, much of the research must be geared toward preliminary findings. The first steps to understanding Misophonia comes from academic and ethically conducted research that will lay the groundwork for future studies and findings. The IMRN works vehemently to ensure that several angles of research are being explored. We are not committed to one theory over another. Our focus on research is about the journey. As research changes and develops, so will our ideas on the disorder.
There seems to be an overlap between SPD SOR (Sensory Processing Disorder; Sub-set Sensory Over Responsivity) and Misophonia. However, this overlap is entirely based on symptoms. Whether or not the two are related remains to be seen. Though, due to the close over-lap, Lucy Miller of the SPD Foundation has joined the IMRN advisory board to help facilitate research to see if the two may in-fact be related. If this is true, this explains the similarities between misophonics, autistics, Aspergers patients, as well as other disorders.
The cause of Misophonia is secondary right now to its impact on the lives of sufferers. As a magazine and news site we hope to connect sufferers with their researchers. Since there is no official cure it is important that we act as shoulders and support systems for each other. Together we can ask for answers. The IMRN does not believe that one researchers proposals are more important than another. Though we may currently be fundraising for one lab this does not mean that we are not exploring all avenues. A cross-disciplinary approach is our best case scenario when it comes to finding answers. This means that audiologists, neurologists, psychologists, and several professionals are the key to finding answers. When asking ‘what is misophonia?’ we must realize that it is through working together that we find the greatest answers.
Selenium Protects a Specific Type of Interneurons in The Brain
Exactly 200 years ago, the Swedish scientist Jöns Jacob Berzelius discovered the trace element selenium, which he named after the goddess of the moon, Selene. Besides its industrial applications (chemical industry, production of semiconductors and toners), selenium is an essential trace element and indispensable for humans, many animals and some bacteria. A team led by Dr. Marcus Conrad, research group leader at the Institute of Developmental Genetics (IDG) at Helmholtz Zentrum München, showed for the first time why selenium is a limiting factor for mammals.
Scientific ‘by-catch’ solves decades-old mystery
The scientists have been investigating for years the processes of a novel type of cell death, known as ferroptosis. In this context, the enzyme GPX4, which normally contains selenium in the form of the amino acid selenocysteine, plays an important role.
In order to better understand the role of GPX4 in this death process, we established and studied mouse models in which the enzyme was modified,” said study leader Conrad. “In one of these models, we observed that mice with a replacement of selenium to sulfur in GPX4 did not survive for longer than three weeks due to neurological complications.”
In their search for the underlying reasons, the researchers identified a distinct subpopulation of specialized neurons in the brain, which were absent when selenium-containing GPX4 was lacking. “In further studies, we were able to show that these neurons were lost during postnatal development, when sulfur- instead of selenium-containing GPX4 was present,” stated first author of the study, Irina Ingold.
Furthermore, the scientists were able to show that ferroptosis is triggered by oxidative stress, which is known to occur for instance during high metabolic activity of cells and high neuronal activity. “Our study demonstrates for the first time that selenium is an essential factor for the postnatal development of a specific type of interneurons,” said Dr. José Pedro Friedmann Angeli, a scientist at the IDG, describing the results. “Selenium-containing GPX4 protects these specialized neurons from oxidative stress and from ferroptotic cell death.”
Thus, the study explains why certain selenoenzymes are essential in some organisms, including mammals, whereas they are dispensable in other organisms, such as fungi and higher plants. In future investigations, study leader Marcus Conrad and his team aim to investigate how ferroptosis is triggered in cells. As a long-term goal, he wants to elucidate the role of ferroptosis in various disease conditions in order to be able to alleviate diseases, such as cancer or neurodegeneration, which are currently difficult to tackle.
Journal Reference:
Irina Ingold, Carsten Berndt, Sabine Schmitt, Sebastian Doll, Gereon Poschmann, Katalin Buday, Antonella Roveri, Xiaoxiao Peng, Florencio Porto Freitas, Tobias Seibt, Lisa Mehr, Michaela Aichler, Axel Walch, Daniel Lamp, Martin Jastroch, Sayuri Miyamoto, Wolfgang Wurst, Fulvio Ursini, Elias S.J. Arnér, Noelia Fradejas-Villar, Ulrich Schweizer, Hans Zischka, José Pedro Friedmann Angeli, Marcus Conrad. Selenium Utilization by GPX4 Is Required to Prevent Hydroperoxide-Induced Ferroptosis. Cell, 2017; DOI: 10.1016/j.cell.2017.11.048
Story Source:
Materials provided by Helmholtz Zentrum München – German Research Center for Environmental Health.
This important nutrient is vital to immune system function. Selenium works in conjunction with vitamin E, vitamin C, glutathione and vitamin B3 as an antioxidant to prevent free radical damage in the body. It’s thought to help prevent cancer by affecting oxidative stress, inflammation and DNA repair. Selenium has been found to be important to male fertility; increasing selenium levels leads to improved sperm motility. There is preliminary research that suggests that selenium supplementation may also help with asthma symptoms, but more studies are needed.
Selenium Deficiencies
Deficiencies of selenium can occur in areas where soil content of this mineral is low. Diets high in refined foods may also lead to deficiency, as selenium can be destroyed by food processing. Taking anti-inflammatory drugs may reduce the body’s supply of selenium.
Low selenium levels can contribute to autoimmune problems, such as psoriasis and thyroid disease. Low levels have also been tied to stomach, throat and prostate cancers, although more research is needed to determine if this is a cause or a result of the disease. Some studies suggest that selenium deficiency is linked to mood disorders. There’s indication that deficiencies in selenium may contribute to the progression of viral infections.
10 Selenium Food Sources
The selenium content in foods depends on the concentration of selenium in the soil where the crops were grown. The following foods are generally considered good sources of selenium:
Exceeding 400 mcg per day can lead to selenium toxicity. Side effects may include hair loss, white spots on fingernails, fatigue, dizziness, nausea and nerve damage. There’s some evidence that high selenium levels may increase the risk of squamous cell skin cancer. Another well controlled study found a correlation between higher levels of selenium and an increased risk of developing type-2 diabetes.
Because of the possibility of toxicity, selenium supplements are controversial. The safest way to ensure a sufficient level of selenium in the diet is by eating a variety of selenium rich foods, like those listed above. Brazil nuts can be very high in selenium and should only be eaten occasionally. One Brazil nut can supply a whole day’s requirement of selenium, although this can vary depending on soil conditions. A multivitamin that contains some selenium is safe for most people to take and can help to fill the gap in a diet that is lacking.
