Year: 2025

Categories : Cardiovascular DiseaseTags :

Intermuscular Fat Raises the Risk of Heart Attack or Failure

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Photo by I Yunmai on Unsplash

People with intermuscular fat are at a higher risk of dying or being hospitalised from a heart attack or heart failure, regardless of their body mass index, according to research published in the European Heart Journal.

This intermuscular fat is highly prized in beef steaks for cooking but little is known about it in humans, and its impact on health. This is the first study to comprehensively investigate the effects of fatty muscles on heart disease.

The new finding adds evidence that existing measures, such as body mass index or waist circumference, are not adequate to evaluate the risk of heart disease accurately for all people.

The new study was led by Professor Viviany Taqueti, Director of the Cardiac Stress Laboratory at Brigham and Women’s Hospital and Faculty at Harvard Medical School, Boston, USA. She said: “Obesity is now one of the biggest global threats to cardiovascular health, yet body mass index – our main metric for defining obesity and thresholds for intervention – remains a controversial and flawed marker of cardiovascular prognosis. This is especially true in women, where high body mass index may reflect more ‘benign’ types of fat.

“Intermuscular fat can be found in most muscles in the body, but the amount of fat can vary widely between different people. In our research, we analyse muscle and different types of fat to understand how body composition can influence the small blood vessels or ‘microcirculation’ of the heart, as well as future risk of heart failure, heart attack and death.”

The new research included 669 people who were being evaluated at the Brigham and Women’s Hospital for chest pain and/or shortness of breath and found to have no evidence of obstructive coronary artery disease (where the arteries that supply the heart are becoming dangerously clogged). These patients had an average age of 63. The majority (70%) were female and almost half (46%) were non-white.

All the patients were tested with cardiac positron emission tomography/computed tomography (PET/CT) scanning to assess how well their hearts were functioning. Researchers also used CT scans to analyse each patient’s body composition, measuring the amounts and location of fat and muscle in a section of their torso.

To quantify the amount of fat stored within muscles, researchers calculated the ratio of intermuscular fat to total muscle plus fat, a measurement they called the fatty muscle fraction.

Patients were followed up for around six years and researchers recorded whether any patients died or were hospitalised for a heart attack or heart failure.

Researchers found that people with higher amounts of fat stored in their muscles were more likely to have damage to the tiny blood vessels that serve the heart (coronary microvascular dysfunction or CMD), and they were more likely to go on to die or be hospitalised for heart disease. For every 1% increase in fatty muscle fraction, there was a 2% increase in the risk of CMD and a 7% increased risk of future serious heart disease, regardless of other known risk factors and body mass index.

People who had high levels of intermuscular fat and evidence of CMD were at an especially high risk of death, heart attack and heart failure. In contrast, people with higher amounts of lean muscle had a lower risk. Fat stored under the skin (subcutaneous fat) did not increase the risk.

Professor Taqueti said: “Compared to subcutaneous fat, fat stored in muscles may be contributing to inflammation and altered glucose metabolism leading to insulin resistance and metabolic syndrome. In turn, these chronic insults can cause damage to blood vessels, including those that supply the heart, and the heart muscle itself.

“Knowing that intermuscular fat raises the risk of heart disease gives us another way to identify people who are at high risk, regardless of their body mass index. These findings could be particularly important for understanding the heart health effects of fat and muscle-modifying incretin-based therapies, including the new class of glucagon-like peptide-1 receptor agonists.

“What we don’t know yet is how we can lower the risk for people with fatty muscles. For example, we don’t know how treatments such as new weight-loss therapies affect fat in the muscles relative to fat elsewhere in the body, lean tissue, and ultimately the heart.”

Professor Taqueti and her team are assessing the impact of treatments strategies including exercise, nutrition, weight-loss drugs or surgery, on body composition and metabolic heart disease.

In an accompanying editorial, Dr Ranil de Silva from Imperial College London and colleagues said: “Obesity is a public health priority. Epidemiologic studies clearly show that obesity is associated with increased cardiovascular risk, though this relationship is complex.

“In this issue of the Journal, Souza and colleagues hypothesise that skeletal muscle quantity and quality associate with CMD and modify its effect on development of future adverse cardiovascular events independent of body mass index (BMI).

“In this patient population who were predominantly female and had a high rate of obesity, the main findings were that increasing levels of intermuscular adipose tissue (IMAT) were associated with a greater occurrence of CMD, and that the presence of both elevated IMAT and CMD was associated with the highest rate of future adverse cardiovascular events, with this effect being independent of BMI.

“The interesting results provided by Souza et al are hypothesis generating and should be interpreted in the context of several limitations. This is a retrospective observational study. Whilst a number of potential mechanisms are suggested to explain the relationship between elevated IMAT and impaired coronary flow reserve, these were not directly evaluated. In particular, no details of circulating inflammatory biomarkers, insulin resistance, endothelial function, diet, skeletal muscle physiology, or exercise performance were given.

“The data presented by Souza et al. are intriguing and importantly further highlight patients with CMD as a population of patients at increased clinical risk. Their work should stimulate further investigation into establishing the added value of markers of adiposity to conventional and emerging cardiac risk stratification in order to identify those patients who may benefit prognostically from targeted cardiometabolic interventions.”

Source: European Society of Cardiology

Categories : New Compounds and Treatments OphthalmologyTags :

New Potential Treatment for Inherited Blinding Disease Retinitis Pigmentosa

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Researchers used a computer screening approach to identify two compounds that could help prevent vision loss in people with a genetic eye disease

Photoreceptor cells in the retina. Credit: Scientific Animations

Two new compounds may be able to treat retinitis pigmentosa, a group of inherited eye diseases that cause blindness. The compounds, described in a study published January 14th in the open-access journal PLOS Biology by Beata Jastrzebska from Case Western Reserve University, US, and colleagues, were identified using a virtual screening approach.

In retinitis pigmentosa, the retina protein rhodopsin is often misfolded due to genetic mutations, causing retinal cells to die off and leading to progressive blindness. Small molecules to correct rhodopsin folding are urgently needed to treat the estimated 100 000 people in the United States with the disease. Current experimental treatments include retinoid compounds, such as synthetic vitamin A derivatives, which are sensitive to light and can be toxic, leading to several drawbacks.

In the new study, researchers utilised virtual screening to search for new drug-like molecules that bind to and stabilise the structure of rhodopsin to improve its folding and movement through the cell. Two non-retinoid compounds were identified which met these criteria and had the ability to cross the blood-brain and blood-retina barriers. The team tested the compounds in the lab and showed that they improved cell surface expression of rhodopsin in 36 of 123 genetic subtypes of retinitis pigmentosa, including the most common one. Additionally, they protected against retinal degeneration in mice with retinitis pigmentosa.

“Importantly, treatment with either compound improved the overall retina health and function in these mice by prolonging the survival of their photoreceptors,” the authors say. However, they note that additional studies of the compounds or related compounds are needed before testing the treatments in humans.

The authors add, “Inherited mutations in the rhodopsin gene cause retinitis pigmentosa (RP), a progressive and currently untreatable blinding disease. This study identifies small molecule pharmacochaperones that suppress the pathogenic effects of various rhodopsin mutants in vitro and slow photoreceptor cell death in a mouse model of RP, offering a potential new therapeutic approach to prevent vision loss.”

Provided by PLOS

Categories : Diet and NutritionTags :

Developing a Grapefruit that Won’t Interfere with Medication Levels

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Photo by Olga Petnyunene on Unsplash

Grapefruit and pummelo contain compounds called furanocoumarins that may affect the blood levels of more than 100 prescription drugs, so that people taking these medications are advised to remove these fruits from their diets. Research published in New Phytologist reveals genetic information about the synthesis of furanocoumarins in different citrus plant tissues and species and provides new insights that could be used to develop grapefruit and pummelo that lack furanocoumarins.

The research indicates that the production of furanocoumarins in citrus fruit is dependent on the integrity of a single gene within a multi-gene cluster that encodes enzymes of the 2-oxoglutarate-dependent dioxygenase family.

“This research helps us to understand why fruit of certain citrus species produce furanocoumarins and demonstrates how breeders and researchers could develop furanocoumarin-free citrus varieties,” said co–corresponding author Yoram Eyal, PhD, of the Volcani Center, in Israel.

Source: Wiley

Categories : HIVTags :

Decoding How HIV Hijacks our Cellular Machinery

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Colourised transmission electron micrograph of an HIV-1 virus particle (yellow/gold) budding from the plasma membrane of an infected H9 T cell (purple/green).

A team of scientists at the Helmholtz Institute for RNA-based Infection Research (HIRI) in Würzburg and the University of Regensburg has unveiled insights into how HIV-1 skilfully hijacks cellular machinery for its own survival. By dissecting the molecular interplay between the virus and its host, the researchers identified novel strategies that HIV-1 employs to ensure its replication while suppressing the host’s cellular defences. The study was published in the journal Nature Structural and Molecular Biology.

HIV-1, like other viruses, lacks the machinery to produce its own proteins and must rely on the host cell to translate its genetic instructions. After entering host cells, it seizes control of the translation process, which converts messenger ribonucleic acid (mRNA) into proteins. “In this study, we combined ribosome profiling, RNA sequencing and RNA structural probing to map the viral and host translational landscape and pausing during replication of the virus in unprecedented detail,” says corresponding author Neva Caliskan.

Cheat Codes of Viral Translation

One of the key findings was the discovery of previously unrecognized elements in HIV-1 RNA called upstream open reading frames (uORFs) and internal open reading frames (iORFs). These “hidden gene fragments” may play a crucial role in fine-tuning the production of viral proteins as well as the interaction with the host immune system. “For instance, uORFs and iORFs can act as regulators, ensuring precise timing and levels of protein synthesis”, explains Anuja Kibe, a postdoctoral researcher at the HIRI and first author of the study.

Another important discovery was an intricate RNA structure near the critical “frameshift site” in the viral genome. This frameshift site is essential for the virus to produce the correct proportions of two key proteins, Gag and Gag-Pol, which are necessary for assembling infectious particles and replication of HIV-1. The researchers demonstrated that this extended RNA fold not only promotes ribosome collisions upstream of the site (a mechanism that appears to regulate translation) but also maintains the frameshifting efficiency. “Our team also showed that targeting this RNA structure with antisense molecules could significantly reduce frameshift efficiency by nearly 40 percent, offering a promising new avenue for antiviral drug development”, reports Caliskan. 

A Game of Priorities

Redmond Smyth, a former Helmholtz Young Investigator Group Leader at the HIRI and currently a group leader at the Centre National de Recherche Scientifique (CNRS) in Strasbourg, France, mentions, “Interestingly, our analysis revealed that, while HIV-1 mRNAs are translated efficiently throughout infection, the virus suppresses the protein production of the host, particularly at the translation initiation stage.” This allows HIV-1 to prioritise its own needs while effectively stalling the host defence mechanisms. Thus, the virus can manipulate the host cell machinery in ways that remain robust even under stress conditions.

More Than Traffic Jams

The researchers also observed that ribosomes collide at specific regions of the viral RNA, particularly upstream of the frameshift site. “These collisions are not accidental but are instead tightly regulated pauses that may influence how ribosomes interact with downstream RNA structures,” says Florian Erhard, study co-author and Chair of Computational Immunology at the University of Regensburg.

Overall, the study provides not only a detailed map of the translational landscape of HIV-1 infected cells but also a wealth of potential targets for therapeutic intervention. The identification of RNA structures and genetic elements critical for viral replication highlights new opportunities for the development of drugs aimed at disrupting these processes. “By understanding how the virus cleverly manipulates our cells, these discoveries will bring us closer to innovative treatments that could one day turn tables and outsmart the virus itself,” Caliskan adds.

Source: Helmholtz Centre for Infection Research

Categories : Genetics Neurodegenerative DiseasesTags :

Brain Changes in Huntington’s Disease Seen Decades ahead of Symptoms

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Photo by Robina Weermeijer on Unsplash

Subtle changes in the brain, detectable through advanced imaging, blood and spinal fluid analysis, happen approximately twenty years before a clinical motor diagnosis in people with Huntington’s disease, finds a new study led by UCL researchers which appears in Nature Medicine.

The team found that although functions such as movement, thinking or behaviour remained normal for a long time before the onset of symptoms in Huntington’s disease, subtle changes to the brain were taking place up to two decades earlier. These findings pave the way for future preventative clinical trials, offer hope for earlier interventions that could preserve brain function and improve outcomes for individuals at risk of Huntington’s disease.

Huntington’s disease is a devastating neurodegenerative condition affecting movement, thinking and behaviour. It is a genetic disease and people with an affected parent have a 50% chance of inheriting the Huntington’s disease mutation, meaning they will develop disease symptoms – typically in mid-adulthood.

The disease is caused by repetitive expansions of three DNA blocks (C, A and G) in the huntingtin gene. This sequence tends to continually expand in certain cells over a person’s life, in a process known as somatic CAG expansion. This ongoing expansion accelerates neurodegeneration, making brain cells more vulnerable over time.

For the new study, the researchers studied 57 people with the Huntington’s disease gene expansion, who were calculated as being on average 23.2 years from a predicted clinical motor diagnosis.  

They were examined at two time points over approximately five years to see how their bodies and brains changed over time. Their results were compared to 46 control participants, matched closely for age, sex and educational level.

As part of the study, all participants volunteered to undergo comprehensive assessments of their thinking, movement and behaviour, alongside brain scans and blood and spinal fluid sampling.

Importantly, the group with Huntington’s disease gene expansion showed no decline in any clinical function (thinking, movement or behaviour) during the study period, compared to the closely matched control group.

However, compared to the control group, subtle changes were detected in brain scans and spinal fluid biomarkers of those with Huntington’s disease gene expansion. This indicates that the neurodegenerative process begins long before symptoms are evident and before a clinical motor diagnosis.

Specifically, the researchers identified elevated levels of neurofilament light chain (NfL), a protein released into the spinal fluid when neurons are injured, and reduced levels of proenkephalin (PENK), a neuropeptide marker of healthy neuron state that could reflect changes in the brain’s response to neurodegeneration.

Lead author, Professor Sarah Tabrizi (UCL Huntington’s Disease Research Centre, UCL Queen Square Institute of Neurology, and UK Dementia Research Institute at UCL), said: “Our study underpins the importance of somatic CAG repeat expansion driving the earliest neuropathological changes of the disease in living humans with the Huntington’s disease gene expansion. I want to thank the participants in our young adult study as their dedication and commitment over the last five years mean we hope that clinical trials aimed at preventing Huntington’s disease will become a reality in the next few years.”

The findings suggest that there is a treatment window, potentially decades before symptoms are present, where those at risk of developing Huntington’s disease are functioning normally despite having detectable measures of subtle, early neurodegeneration. Identifying these early markers of disease is essential for future clinical trials in order to determine whether a treatment is having any effect.

Co-first author of the study, Dr Rachael Scahill (UCL Huntington’s Disease Research Centre and UCL Queen Square Institute of Neurology) said: “This unique cohort of individuals with the Huntington’s disease gene expansion and control participants provides us with unprecedented insights into the very earliest disease processes prior to the appearance of clinical symptoms, which has implications not only for Huntington’s disease but for other neurodegenerative conditions such as Alzheimer’s disease.”

This study is the first to establish a direct link between somatic CAG repeat expansion, measured in blood, and early brain changes in humans, decades before clinical motor diagnosis in Huntington’s disease.

While somatic CAG expansion was already known to accelerate neurodegeneration, this research demonstrates how it actively drives the earliest detectable changes in the brain: specifically in the caudate and putamen, regions critical to movement and thinking.

By showing that somatic CAG repeat expansion changes measured in blood predicts brain volume changes and other markers of neurodegeneration, the findings provide crucial evidence to support the hypothesis that somatic CAG expansion is a key driver of neurodegeneration.

With treatments aimed at suppressing somatic CAG repeat expansion currently in development, this work validates this mechanistic process as a promising therapeutic target and represents a critical advance towards future prevention trials in Huntington’s disease.

Co-first author of the study, Dr Mena Farag (UCL Huntington’s Disease Research Centre and UCL Queen Square Institute of Neurology) added: “These findings are particularly timely as the Huntington’s disease therapeutic landscape expands and progresses toward preventive clinical trials.”

The research was done in collaboration with experts at the Universities of Glasgow, Gothenburg, Iowa, and Cambridge.

Source: University College London

Categories : HospitalsTags :

Windows in ICU Rooms Increase the Risk of Post-surgical Delirium

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Photo by Rodnae Productions on Pexels

Delirium is a condition common in the post-surgical intensive care unit (ICU) setting, affecting up to 50-70% of those admitted, depending on individual risk profiles. ICU delirium can be associated with a multitude of factors including underlying and acute medical conditions, pharmacologic agents or treatment regimens like surgery. Currently there is no definitive consensus on drug interventions that aid in the prevention of delirium or its treatment.

While there has been some evidence that the ICU environment plays a role in delirium, more research is needed to understand this association. In a new study appearing in Critical Care Medicine, researchers found windowed patient rooms were associated with an increase in the odds of developing delirium, when compared to patient rooms without windows.

Using electronic medical records, researchers from Mass General Brigham and collaborators at Boston University Chobanian & Avedisian School of Medicine reviewed the association between patients being admitted to an ICU room with or without windows and the presence of delirium. Delirium was observed in 21% (460/2235) of patients in windowed rooms and 16% (206/1292) of patients in non-windowed rooms.

“While the findings of the study were ultimately unexpected due to prior research suggesting the importance of circadian rhythm while in the hospital, our results contribute to a growing body of evidence-based design literature around the importance of healthcare design to patient experience and outcomes,” explained corresponding author Diana Anderson, MD, FACHA, assistant professor of neurology at the school. She notes that because of the study design, these unexpected findings are not causative and may represent different patterns in which some patients – who are potentially at an increased risk of delirium – may be assigned to different room layouts by the clinical teams.

According to the authors, further research into the specific qualities of windows that may impact health is needed to better understand these results. “Although this study adds to our understanding of the relationship between delirium and characteristics of the built environment, it is clear that additional studies may provide further insight to understand these results. For example, it is possible that the window view toward adjacent landscapes or buildings may be important context to interpret these findings, or perhaps another feature of the room such as light or sound that we could consider in our next investigation,” Anderson says.

Source: Boston University School of Medicine

Categories : DermatologyTags :

Survey Sheds Light on the Phenomenon of Topical Steroid Withdrawal

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Source: Pixabay

Painful skin and trouble sleeping are among the problems reported when tapering cortisone cream for atopic eczema, as shown by a study headed by the University of Gothenburg. Many users consider the problems to be caused by cortisone dependence.

Topical steroid withdrawal (TSW) is a phenomenon commonly described as extremely red and painful skin arising when cortisone cream treatment is tapered or stopped.

While TSW is not an established diagnosis, the name indicates that the skin has become dependent on cortisone. Little research has been conducted to identify a dependency mechanism, so scientific support is lacking. At the same time, the term has become commonplace on social media, raising concerns among patients about cortisone cream safety.

Now, a national research group in Sweden, headed by Sahlgrenska Academy at the University of Gothenburg, has conducted the first study in which a larger group has been asked to provide a detailed account of what they consider to be TSW. The results are published in the journal Acta Dermato-Venereologica.

Questionnaire via social media

The study targeted adults with atopic eczema, a group that often uses cortisone cream, who also identified as suffering from TSW. The study was conducted by means of an anonymous questionnaire presented in Swedish in social media forums, with the option to share a link to invite other potential participants. The questionnaire was answered by almost one hundred people aged 18–39, the majority of whom were women.

“We wanted to gain more knowledge about how those who identify as suffering from TSW define the phenomenon and which symptoms they describe,” says Mikael Alsterholm, a researcher at the University of Gothenburg and a senior consultant in dermatology and venereology at Sahlgrenska University Hospital.

The results show variations in how the participants defined TSW. Most common was to define it as a dependence on cortisone, with symptoms arising when tapering or stopping its use, although many others also defined TSW as a reaction to cortisone already during its use.

It was also common to define TSW on the basis of the symptoms seen in the skin, such as redness and pain. While the symptoms described varied, they were largely similar to the symptoms seen in an exacerbation of atopic eczema.

In addition to the skin becoming red, dry, and blistered – mainly on the face, neck, torso, and arms – the participants also described sleep problems due to itching as well as signs of anxiety and depression.

Healthcare and research involvement

A majority of the participants described concurrent symptoms of both atopic eczema and TSW. Cortisone cream was most often cited as the triggering factor, while some cited cortisone tablets and a few cortisone-free treatments.

“It’s important that healthcare professionals and researchers are involved in the discussion on TSW and contribute science-based knowledge where possible. Cortisone cream is an effective and safe treatment for most people, and at present there’s no support for avoiding its use for fear of the types of symptoms described in the context of TSW,” says Mikael Alsterholm.

“At the same time, there’s a patient group with different experiences, expressed as TSW, and their symptoms and the potential causes need to be investigated by means of both research and practical healthcare. To do this, we first need to define TSW. While we understand that this is complicated, we hope that this study can help establish such a definition,” he concludes.

Source: University of Gothenburg

Categories : Neurodegenerative Diseases New Compounds and TreatmentsTags :

Noble Intentions: Xenon Gas might Protect against Alzheimer’s

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By Alchemist-hp (talk) (www.pse-mendelejew.de) – Own work, FAL

Most treatments being pursued today to protect against Alzheimer’s disease focus on amyloid plaques and tau tangles that accumulate in the brain, but new research from Mass General Brigham and Washington University School of Medicine in St. Louis points to a novel – and noble – approach: using xenon gas. The study found that xenon gas inhalation suppressed neuroinflammation, reduced brain atrophy, and increased protective neuronal states in mouse models of Alzheimer’s disease. Results are published in Science Translational Medicine, and a phase 1 clinical trial of the treatment in healthy volunteers will begin in early 2025.

“It is a very novel discovery showing that simply inhaling an inert gas can have such a profound neuroprotective effect,” said senior and co-corresponding author Oleg Butovsky, PhD, at Brigham and Women’s Hospital (BWH). “One of the main limitations in the field of Alzheimer’s disease research and treatment is that it is extremely difficult to design medications that can pass the blood-brain barrier – but senon gas does. We look forward to seeing this novel approach tested in humans.”

“It is exciting that in both animal models that model different aspects of Alzheimer’s disease, amyloid pathology in one model and tau pathology in another model, that Xenon had protective effects in both situations,” said senior and co-corresponding author David M. Holtzman, MD, from Washington University School of Medicine in St. Louis.

The causes of Alzheimer’s disease are not fully understood; there is currently no cure, and more effective treatments are desperately needed. Characterised by protein buildups in the brain, including tau and amyloid, Alzheimer’s disease disrupts nerve cell communication and causes progressive brain abnormalities that lead to neuronal damage and ultimately to death. Microglia, the brain’s primary and most prominent immune cells, act as ‘first responders’ when something goes awry in the brain, and they play a key role in regulating brain function in all phases of development. Microglial dysregulation is a key component of Alzheimer’s disease. Butovsky’s lab previously designed a way to study how microglia respond to neurodegeneration and confirmed that a specific phenotype of microglia can be modulated in a way that is protective in Alzheimer’s disease.

In this study, mouse models of Alzheimer’s disease were treated with xenon gas that has been used in human medicine as an anesthetic and as a neuroprotectant for treating brain injuries. Xenon gas penetrates the blood-brain barrier, passing from the bloodstream directly into the fluid surrounding the brain. The team found that xenon gas inhalation reduced brain atrophy and neuroinflammation and improved nest-building behaviours in the Alzheimer’s disease mouse models. It also induced and increased a protective microglial response that is associated with clearing amyloid and improving cognition. Together, these findings identify the promising potential of xenon inhalation as a therapeutic approach that could modify microglial activity and reduce neurodegeneration in Alzheimer’s disease.

The clinical trial at Brigham and Women’s Hospital, which will initially only enrol healthy volunteers, is set to begin in the next few months.

As early phases of the clinical trial get underway to establish safety and dosage, the research team plans to continue to study the mechanisms by which xenon gas achieves its effects in addition to its potential for treating other diseases such as multiple sclerosis, amyotrophic lateral sclerosis, and eye diseases that involve the loss of neurons. The team is also devising technologies to help use xenon gas more efficiently as well as potentially recycle it.

“If the clinical trial goes well, the opportunities for the use of Xenon gas are great,” said co-author Howard Weiner, MD, co-director of the Ann Romney Center for Neurologic Diseases at BWH and principal investigator of the upcoming clinical trial. “It could open the door to new treatments for helping patients with neurologic diseases.”

Source: Mass General Brigham

Categories : Diet and Nutrition VaccinesTags :

Study in SA Children Finds Undernutrition may Weaken Measles Vaccination

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Photo by National Cancer Institute

Amid a global surge in measles cases, new research suggests that undernutrition may be exacerbating outbreaks in areas suffering from food insecurity. A study involving over 600 fully vaccinated children in South Africa found those who were undernourished had substantially lower levels of antibodies against measles.

Researchers from McGill University, UC Berkeley School of Public Health and the University of Pretoria tracked the children’s growth over time as an indicator of undernutrition and measured their antibody levels through blood tests. Children who were stunted around age three had an average of 24-per-cent-lower measles antibody levels by age five compared to their typical-sized peers.

The findings, published in Vaccine, suggest that undernutrition may affect the duration of vaccine protection.

This indicates that addressing child hunger could be a key piece of the puzzle in preventing viral outbreaks, said senior author Jonathan Chevrier, an Associate Professor at McGill.

A growing threat worldwide

Measles is a highly contagious viral infection that causes symptoms such as a rash, fever and cough, and can lead to severe complications, especially in young children. The disease is a threat in regions where it was once under control, including Canada, which in 2024 reported its highest number of cases in nearly a decade.

“Global measles cases declined from 2000 to 2016, but the trend reversed in 2018, driven in part by under-vaccination and the impact of the pandemic. Measles is now making a strong comeback in many parts of the world despite being preventable with vaccination and adequate immunity,” said co-author Brian Ward, Professor at McGill’s.

“We need to vaccinate children against infectious diseases that are preventable and ensure they are protected,” said first author Brenda Eskenazi, Professor at the University of California, Berkeley. “This is especially important now, given that many known diseases are expected to spread with climate change.”

About 22% of children under age five worldwide – approximately 148 million – were stunted in 2022, Chevrier added, with the highest rates in Asia and sub-Saharan Africa.

The team plans to monitor the children in the study as they grow older to understand whether the effects of early-life undernutrition persist.

Source: McGill University

Categories : DermatologyTags :

Sunburn Results from Damage to RNA, not DNA

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The warnings against sunburn are well known: avoid direct sunlight between 12 noon and 3pm, seek out shade and put on sunscreen and a hat. It is also taught that sunburn results from damage to DNA. But that is not the full truth, according the researchers behind a new study conducted at the University of Copenhagen and Nanyang Technological University, Singapore (NTU Singapore).

“Sunburn damages the DNA, leading to cell death and inflammation. So the textbooks say. But in this study we were surprised to learn that this is a result of damage to the RNA, not the DNA that causes the acute effects of sunburn,” says Assistant Professor Anna Constance Vind, who is one of the researchers responsible for the new study.

The study has been published in Molecular Cell.

RNA is a more transient molecule than DNA. A type of RNA, known as messenger RNA (mRNA), functions as the intermediate ‘messenger’ that carries information from DNA to make proteins – the basic building blocks of cellular components.

“DNA damage is serious as the mutations will get passed down to progenies of the cells, RNA damage happens all the time and does not cause permanent mutations. Therefore, we used to believe that the RNA is less important, as long as the DNA is intact. But in fact, damages to the RNA are the first to trigger a response to UV radiation,” Anna Constance Vind explains.

The new study was conducted on mice as well as human skin cells, and the objective was to describe the impact of UV radiation on the skin and what causes these damages. The researchers found the same skin response to UV radiation exists in both mice and human cells.

A built-in surveillance system for RNA damage

mRNA damage triggers a response in ribosomes (protein complexes that “read” the mRNA to synthesise protein), orchestrated by a protein known as ZAK-alpha – the so-called ribotoxic stress response – the new study shows. The response can be described as a surveillance system within the cells, which registers the RNA damage, leading to inflammatory signalling and recruitment of immune cells, which then leads to inflammation of the skin.

“We found that the first thing the cells respond to after being exposed to UV radiation is damage to the RNA, and that this is what triggers cell death and inflammation of the skin. In mice exposed to UV radiation we found responses such as inflammation and cell death, but when we removed the ZAK gene, these responses disappeared, which means that ZAK plays a key role in the skin’s response to UV-induced damage,” says Professor Simon Bekker-Jensen from the Department of Cellular and Molecular Medicine, who is one of the other researchers responsible for the study. He adds:

“So you could say that everything depends on this one response, which monitors all protein translations occurring. The cells respond to the RNA damage, realising that something is wrong, and this is what leads to cell death.”

Faster and more effective response

The result of the study changes our understanding of sunburn and the skin’s defence mechanisms: that RNA damage triggers a faster and more effective response, protecting the skin from further damage.

“The fact that the DNA does not control the skin’s initial response to UV radiation, but that something else does and that it does so more effectively and more quickly, is quite the paradigm shift,” says Anna Constance Vind.

We need to understand the function of RNA damage, as it may in the long term change our entire approach to prevention and treatment of sunburn.

“Many inflammatory skin diseases are worsened by sun exposure. Thus, understanding how our skin responds at the cellular level to UV damage opens the door to innovative treatments for certain chronic skin conditions,” says co-author Dr Franklin Zhong, Nanyang Assistant Professor at NTU’s Lee Kong Chian School of Medicine.

“This new knowledge turns things upside down. I think most people associate sunburn with DNA damage; it is established knowledge. But now we need to rewrite the textbooks, and it will affect future research on the effects of UV radiation on the skin,” Simon Bekker-Jensen concludes.

Source: University of Copenhagen