Mice study suggests metabolic diseases may be driven by gut microbiome, loss of ovarian hormones

Mice that received fecal implants from donors that had their ovaries removed gained more fat mass and had greater expression of liver genes associated with inflammation, Type 2 diabetes, fatty liver disease and atherosclerosis. The findings may shed light on the greater incidence of metabolic dysfunction in postmenopausal women. The team members included, from left: molecular and integrative physiology professor Erik R. Nelson; Kelly Swanson, the director of the Division of Nutritional Sciences and the Kraft Heinz Endowed Professor in Human Nutrition; and animal sciences professor Brett R. Loman.
  Photo Credit: Fred Zwicky

The gut microbiome interacts with the loss of female sex hormones to exacerbate metabolic disease, including weight gain, fat in the liver and the expression of genes linked with inflammation, researchers found in a new rodent study.

The findings, published in the journal Gut Microbes, may shed light on why women are at significantly greater risk of metabolic diseases such as obesity and Type 2 diabetes after menopause, when ovarian production of female sex hormones diminishes.

“Collectively, the findings demonstrate that removal of the ovaries and female hormones led to increased permeability and inflammation of the gut and metabolic organs, and the high-fat diet exacerbated these conditions,” said Kelly S. Swanson, the director of the Division of Nutritional Sciences and the Kraft Heinz Endowed Professor in Human Nutrition at the University of Illinois Urbana-Champaign who is a corresponding author of the paper.  “The results indicated that the gut microbiome responds to changes in female hormones and worsens metabolic dysfunction.”

Stopping the awakening of leukemia stem cells to prevent relapse

Acute Myeloid Leukemia
Image Credit: National Cancer Institute

Why myeloid leukemias start to grow again after chemotherapy has killed the bulk of cancerous cells, and how growth may be blocked by repurposed drugs, may have been solved by new research.

The bone marrow of Acute Myeloid Leukemia (AML) patients contains a rare population of leukemic stem cells (LSCs) that do not grow and, therefore, are not killed by chemotherapy.

However, after treatment, these cells start to grow and produce AML cells, but it has until now been unclear as to what kick-starts this process.

In a new study, published in Nature Communications, experts from Newcastle University, the University of Birmingham and the Princess Maxima Centre of Pediatric oncology, studied single cells from patients with t(8;21) AML to investigate what made the rare LSCs grow.

Graphene research: numerous products, no acute dangers

The "Graphene Flagship" initiative has investigated the effects of graphene (blue) and related materials on health and the environment. Colored scanning electron microscopy
Image Credit: Empa

The largest EU research initiative ever launched has come to a successful end: The Graphene Flagship was officially concluded at the end of last year. Empa researchers were also involved, such as molecular biologist Peter Wick, who was part of the Health and Environment work package from the very beginning – and has just summarized the findings in this area with international colleagues in a comprehensive review article in the specialist journal ACS Nano.

Think big. Despite its research topic, this could well be the motto of the Graphene Flagship, which was launched in 2013: With an overall budget of one billion Euros, it was Europe's largest research initiative to date, alongside the Human Brain Flagship, which was launched at the same time. The same applies to the review article on the effects of graphene and related materials on health and the environment, which Empa researchers Peter Wick and Tina Bürki just published together with 30 international colleagues in the scientific journal ACS Nano; on 57 pages, they summarize the findings on the health and ecological risks of graphene materials, the reference list includes almost 500 original publications.

Caring glass frog fathers have smaller testes

Males of the glassfrog species Hyalinobatrachium valerioi are very dedicated fathers.
Photo Credit: © Francesca Angiolani

An international team of researchers including the University of Bern shows in a new study that male glass frogs that care for their offspring have smaller testes than males of species that do not provide any brood care. This indicates an evolutionary trade-off between sperm production and parenting.

Living in the tropical rainforests of Central and South America, frogs of the glass frog family are fascinating because of their transparent skin on their belly, which reveals their internal organs. However, it is not only the appearance of these amphibians that is remarkable, but also their social behavior. In many - but not all - glass frog species, the males remain with the clutch after mating and guard and care for their offspring. In a new study, an international team, including researchers from the Institute of Ecology and Evolution at the University of Bern, shows that there is a link between this paternal care and the testes size of glass frogs. The results were recently published in the journal Proceedings of the Royal Society B.

Long COVID linked to persistently high levels of inflammatory protein: a potential biomarker and target for treatments

"We hope that this could help to pave the way to develop therapies and give some patients a firm diagnosis," -Benjamin Krishna
Photo Credit: Annie Spratt

SARS-CoV-2 triggers the production of the antiviral protein IFN-γ, which is associated with fatigue, muscle ache and depression. New research shows that in Long COVID patients, IFN-y production persists until symptoms improve, highlighting a potential biomarker and a target for therapies.

A University of Cambridge-led study identifies the protein interferon gamma (IFN-γ) as a potential biomarker for Long COVID fatigue and highlights an immunological mechanism underlying the disease, which could pave the way for the development of much needed therapies, and provide a head start in the event of a future coronavirus pandemic. 

The study, published today in Science Advances, followed a group of patients with Long COVID fatigue for over 2.5 years, to understand why some recovered and others did not. 

Long COVID continues to affect millions of people globally and is placing a major burden on health services. An estimated 1.9 million people in the UK alone (2.9% of the population) were experiencing self-reported Long COVID as of March 2023, according to the ONS. Fatigue remains by far the most common and debilitating symptom and patients are still waiting for an effective treatment.

Researchers reveal mechanism of drug reactivating tumor suppressors

Mechanism of methylated-histone inhibitor valemetostat
Researchers revealed the mechanism of the cancer drug valemetostat and established its efficacy in treating adult T-cell leukemia/lymphoma (ATL).
Illustration Credit: ©2024 Makoto Yamagishi, The University of Tokyo

Researchers have revealed the mechanism of a drug shown to be effective in treating certain types of cancer, which targets a protein modification silencing the expression of multiple tumor suppressor genes. They also demonstrated in clinical trials the efficacy of the drug in reducing tumor growth in blood cancer. The findings could lead to longer-term treatments for the disease and therapies for other types of cancer with similar underlying causes.

A team of researchers from the University of Tokyo and their collaborators focused on therapies targeting H3K27me3, a modification on a DNA-packaging histone protein, which plays a large role in regulating gene expression. The modification occurs when methyl groups, each consisting of three hydrogen atoms bonded to a single carbon atom (CH3), are added to the protein in a process called methylation.

The modification, also referred to as being epigenetic (a heritable change in gene function that occurs without altering the sequence of the DNA), has been tied to the repression, or reducing the expression, of tumor suppressor genes, with the accumulation of the methylated histones around the genes.

Baleen whales evolved a unique larynx to communicate

humpback whales
Image Credit: Jeanette Atherton AI generated.

The new results also make it clear that human noise in the oceans severely restricts the animals

The iconic baleen whales, such as the blue, gray and humpback whale, depend on sound for communication in the vast marine environment where they live. However, ever since whale song were first discovered more than 50 years ago, it remained unknown how baleen whales produce their complex vocalizations – until now. A team led by the voice scientists Coen Elemans from the University of Southern Denmark and Tecumseh Fitch from the University of Vienna has now for the first time found that baleen whales evolved novel structures in their larynx to make their vast array of underwater songs. The study was published in the prestigious journal Nature. 

Baleen whales are the largest animals to have ever roamed our planet and as top predators play a vital role in marine ecosystems. To communicate across vast distances and find each other, baleen whales depend critically on the production of sounds that travels far in murky and dark oceans. 

A new study in the prestigious journal Nature reports that baleen whales evolved unique structures in their larynx that enable their low-frequency vocalizations, but also limit their communication range.

"The toothed and baleen whales evolved from land mammals that had a larynx serving two functions: protecting the airways and sound production. However, their transition to aquatic life placed new and strict demands on the larynx to prevent choking underwater.", says Tecumseh Fitch. 

How Does the Brain Make Decisions?

Image Credit: Generated by HM News with AI in Adobe Firefly

Scientists have gained new insights into how neurons in the brain communicate during a decision, and how the connections between neurons may help reinforce a choice.

The study — conducted in mice and led by neuroscientists at Harvard Medical School — is the first to combine structural, functional, and behavioral analyses to explore how neuron-to-neuron connections support decision-making.

“How the brain is organized to help make decisions is a big, fundamental question, and the neural circuitry — how neurons are connected to one another — in brain areas that are important for decision-making isn’t well understood,” said Wei-Chung Allen Lee, associate professor of neurobiology in the Blavatnik Institute at HMS and professor of neurology at Boston Children’s Hospital. Lee is co-senior author on the paper with Christopher Harvey, professor of neurobiology at HMS, and Stefano Panzeri, professor at University Medical Center Hamburg-Eppendorf.

In the research, mice were tasked with choosing which way to go in a maze to find a reward. The researchers found that a mouse’s decision to go left or right activated sequential groups of neurons, culminating in the suppression of neurons linked to the opposite choice.

These specific connections between groups of neurons may help sculpt decisions by shutting down neural pathways for alternative options, Lee said.

Possible trigger for autoimmune diseases discovered

 One of the great mysteries of immunology: the function of B cells (green) in the thymus gland was previously unknown. Researchers have now been able to show that the immune cells help to prevent T cells from attacking the body.
Image Credit: Jan Böttcher, Thomas Korn / TUM

Immune cells must learn not to attack the body itself. A team of researchers from the Technical University of Munich (TUM) and the Ludwig Maximilian University of Munich (LMU) has discovered a previously unknown mechanism behind this: other immune cells, the B cells, contribute to the "training" of the T cells in the thymus gland. If this process fails, autoimmune diseases can develop.

In children and adolescents, the thymus gland functions as a "school for T cells". The organ in our chest is where the precursors of those T cells that would later attack the body's own cells are discarded. Epithelial cells in the thymus present a large number of molecules that occur in the body to the future T cells. If any of them reacts to one of these molecules, a self-destruction program is triggered. T cells that attack the body's own molecules remaining intact and multiplying, on the other hand, can cause autoimmune diseases.

New mechanism discovered

In Nature, the team led by Thomas Korn, Professor of Experimental Neuroimmunology at TUM and a Principal Investigator in the SyNergy Cluster of Excellence, and Ludger Klein, Professor of Immunology at LMU’s Biomedical Center (BMC), describe another previously unknown mechanism behind this.

In addition to the precursors of T cells, the thymus gland also contains other immune cells, the B cells. They develop in the bone marrow but migrate to the thymus in early childhood. "The function of B cells in the thymus gland has been a mystery that has puzzled immunologists for many years," says Thomas Korn. The researchers have now been able to show for the first time that B cells play an active role in teaching T cells which targets not to attack.

Electrons become fractions of themselves in graphene

The fractional quantum Hall effect has generally been seen under very high magnetic fields, but MIT physicists have now observed it in simple graphene. In a five-layer graphene/hexagonal boron nitride (hBN) moire superlattice, electrons (blue ball) interact with each other strongly and behave as if they are broken into fractional charges.
Image Credit: Sampson Wilcox, RLE
(CC BY-NC-ND 4.0 DEED)

The electron is the basic unit of electricity, as it carries a single negative charge. This is what we’re taught in high school physics, and it is overwhelmingly the case in most materials in nature.

But in very special states of matter, electrons can splinter into fractions of their whole. This phenomenon, known as “fractional charge,” is exceedingly rare, and if it can be corralled and controlled, the exotic electronic state could help to build resilient, fault-tolerant quantum computers.

To date, this effect, known to physicists as the “fractional quantum Hall effect,” has been observed a handful of times, and mostly under very high, carefully maintained magnetic fields. Only recently have scientists seen the effect in a material that did not require such powerful magnetic manipulation.

Now, MIT physicists have observed the elusive fractional charge effect, this time in a simpler material: five layers of graphene — an atom-thin layer of carbon that stems from graphite and common pencil lead. They report their results today in Nature.

They found that when five sheets of graphene are stacked like steps on a staircase, the resulting structure inherently provides just the right conditions for electrons to pass through as fractions of their total charge, with no need for any external magnetic field.

The results are the first evidence of the “fractional quantum anomalous Hall effect” (the term “anomalous” refers to the absence of a magnetic field) in crystalline graphene, a material that physicists did not expect to exhibit this effect.

“This five-layer graphene is a material system where many good surprises happen,” says study author Long Ju, assistant professor of physics at MIT. “Fractional charge is just so exotic, and now we can realize this effect with a much simpler system and without a magnetic field. That in itself is important for fundamental physics. And it could enable the possibility for a type of quantum computing that is more robust against perturbation.”