Fat’s unexpected role in muscle stem cell fate

Satellite cells differentiate into muscle cells or self-renew depending on the level of lipid droplets in the cell. Shihuan Kuang, a Purdue University professor of animal sciences, showed for the first time that fat inside adult muscle stem cells regulates their fate.
Purdue University image/courtesy of Shihuan Kuang

Scientists have shown for the first time that fat inside adult muscle stem cells regulates their fate.

“No one had seen such dynamics of lipid droplets in these muscle stem cells, so this discovery is very exciting,” said Shihuan Kuang, a professor of animal sciences at Purdue University, who led the team of scientists. “To then find that they play such a strong role in the fate of the stem cells is remarkable. It has potential implications for muscular diseases, aging and animal sciences.”

Cells contain various kinds of fat, or lipids, that are essential for energy production, cell membrane composition and chemical signaling. Special structures, called lipid droplets, safely store this cellular fat.

Rather than existing as a static pool of resources, researchers discovered the number of these droplets changes significantly in an individual cell and varies from cell to cell. The number of the droplets also regulates what the stem cells become.

The discovery, coupled with newly identified roles of lipids in other stem cell types – including cancer stem cells - suggest fat may be involved in much more than previously thought, Kuang said. The findings are detailed in a paper in the journal Cell Reports.

Scientists make first detection of exotic “X” particles in quark-gluon plasma

In the first millionths of a second after the Big Bang, the universe was a roiling, trillion-degree plasma of quarks and gluons — elementary particles that briefly glommed together in countless combinations before cooling and settling into more stable configurations to make the neutrons and protons of ordinary matter.

In the chaos before cooling, a fraction of these quarks and gluons collided randomly to form short-lived “X” particles, so named for their mysterious, unknown structures. Today, X particles are extremely rare, though physicists have theorized that they may be created in particle accelerators through quark coalescence, where high-energy collisions can generate similar flashes of quark-gluon plasma.

Now physicists at MIT’s Laboratory for Nuclear Science and elsewhere have found evidence of X particles in the quark-gluon plasma produced in the Large Hadron Collider (LHC) at CERN, the European Organization for Nuclear Research, based near Geneva, Switzerland.

The team used machine-learning techniques to sift through more than 13 billion heavy ion collisions, each of which produced tens of thousands of charged particles. Amid this ultradense, high-energy particle soup, the researchers were able to tease out about 100 X particles, of a type known as X (3872), named for the particle’s estimated mass.

Omicron causes less severe illness in animal models than previous variants

A new study confirms that, compared to earlier versions of the SARS-CoV-2 virus, the omicron variant causes less severe disease in mice and hamsters, which are reliable models for understanding COVID-19.

Yoshihiro Kawaoka

The findings, previously available as a preprint and published following peer review today (Jan. 21) in the journal Nature, align with preliminary data from studies of people infected with the variant and offer insight into the nature of the disease with omicron. The variant emerged in late November 2021 and was first identified by scientists in Botswana and South Africa.

Led by Yoshihiro Kawaoka at the University of Wisconsin–Madison, along with Michael Diamond and Adrianus (Jacco) Boon at the Washington University School of Medicine in St. Louis, the collaborative effort was the work of the SARS-CoV-2 Assessment of Viral Evolution (SAVE) program of the National Institute of Allergy and Infectious Diseases.

“SAVE meets four times per week,” Kawaoka explains, and includes teams analyzing sequences from viruses isolated across the world and screening for new variants; teams studying the biology of new variants in animal models; and teams working to isolate viruses for study, examining viral replication and testing how well previous infection or vaccination provides protection against emerging variants. Researchers who typically compete for publications and funding have come together in light of the COVID-19 crisis.

Peter Halfmann

Peter Halfmann, a research associate professor at UW–Madison, was among the first in the world to isolate the omicron variant from human samples for study. The samples came from infected patients in Wisconsin, New York, Georgia and Tokyo, and each contained slight sequence differences.

Once the viruses were isolated from the samples, scientists throughout the SAVE network began to test them in mice and hamsters. Animal studies are an important step in understanding new variants and how well they respond to existing countermeasures, such as vaccines and therapies.

The spike protein of omicron contains more than 30 mutations — a striking number relative to earlier variants. Because current vaccines and antibody treatments are based on these earlier versions, researchers were concerned that vaccines and therapies would be rendered less effective.

Computer models and studies that looked at the binding capacity of the virus to ACE2 receptors, which grant the virus entry into cells, also suggested that omicron would better attach to cells.

The Value of Wind Energy

Video by Graham Bourque | Pacific Northwest National Laboratory

Two teams of researchers from Pacific Northwest National Laboratory (PNNL) have shown that wind energy offers logistical, economic, and environmental value to consumers and utilities from the coast of Oregon to remote villages in Alaska.

In the first study of the grid impacts of offshore wind energy in Oregon, a PNNL team paired offshore wind resource potential from the Oregon coastline with other variable renewable energy sources, including land-based wind and solar. The study helped the team understand how offshore wind could serve electricity demand within Oregon’s transmission network and across the Pacific Northwest.

In the second study, a PNNL team analyzed the value of distributed wind—wind turbines installed near where their energy is consumed, such as for homes, businesses, and communities—for the small, remote community of St. Mary’s, Alaska. The study’s results could help inform utilities of the economic feasibility for installing wind in similar isolated microgrid systems in other remote villages. Additionally, the study revealed potential economic and environmental benefits for the village’s electricity consumers.

Both studies, which were published in the journal Energies, illustrate PNNL’s growing expertise in assessing the value that renewable energy brings for bolstering the grid.

Research team sets new efficiency record for solar cell technology

Asst Prof Hou Yi (right), Dr Chen Wei (left) and their team have developed perovskite/organic tandem solar cells (held by Dr Chen) that achieved a power conversion efficiency of 23.6%.
Source: National University of Singapore.

A team of researchers from the National University of Singapore (NUS) has set a new record in the power conversion efficiency of solar cells made using perovskite and organic materials. This technological breakthrough paves the way for flexible, light-weight, low cost and ultra-thin photovoltaic cells which are ideal for powering vehicles, boats, blinds and other applications.

“Technologies for clean and renewable energy are extremely important for carbon reduction. Solar cells that directly convert solar energy into electricity are among the most promising clean energy technologies. High power conversion efficiency of solar cells is critical for generating more electrical power using a limited area and this, in turn, reduces the total cost of generating solar energy,” explained lead researcher Presidential Young Professor Hou Yi, who is from the NUS Department of Chemical and Biomolecular Engineering and also leading a “Perovskite-based Multi-junction Solar Cells group” at the Solar Energy Research Institute of Singapore at NUS.

“The main motivation of this study is to improve the power conversion efficiency of perovskite/organic tandem solar cells. In our latest work, we have demonstrated a power conversion efficiency of 23.6% - this is the best performance for this type of solar cells to date,” added Dr Chen Wei, Research Fellow at the NUS Department of Chemical and Biomolecular Engineering and the first author of this work.

Air pollution significantly reduces pollination by confusing butterflies and bees

Credit: James Ryalls

Common air pollutants from both urban and rural environments may be reducing the pollinating abilities of insects by preventing them from sniffing out the crops and wildflowers that depend on them, new research has shown.

Scientists from the University of Reading, the University of Birmingham and the UK Centre for Ecology & Hydrology found that there were up to 70% fewer pollinators, up to 90% fewer flower visits and an overall pollination reduction of up to 31% in test plants when common ground-level air pollutants, including diesel exhaust pollutants and ozone, were present.

The study, published in the journal Environmental Pollution, is the first to observe a negative impact of common air pollutants on pollination in the natural environment. The theory is that the pollutants react with and change the scents of flowers, making them harder to find.

Dr Robbie Girling, Associate Professor in Agroecology at the University of Reading, who led the project, said: “We knew from our previous lab studies that diesel exhaust can have negative effects on insect pollinators, but the impacts we found in the field were much more dramatic than we had expected.”

Dr James Ryalls, a Leverhulme Trust Research Fellow at the University of Reading, who conducted the study, said: “The findings are worrying because these pollutants are commonly found in the air many of us breathe every day. We know that these pollutants are bad for our health, and the significant reductions we saw in pollinator numbers and activity shows that there are also clear implications for the natural ecosystems we depend on.”

Dr Christian Pfrang, Reader in Atmospheric Science at the University of Birmingham and a co-author on the study, said: “This truly cross-disciplinary work demonstrated very clearly how atmospheric pollutants negatively impact on pollination with direct consequences for food production as well as the resilience of our natural environment.”

Scientists build ‘valves’ in DNA to shape biological information flows

DNA valve controlling molecular processes along DNA
Credit: Thomas Gorochowski

Scientists at the University of Bristol have developed new biological parts that are able to shape the flow of cellular processes along DNA.

The work, now published in the journal Nature Communications, offers a fresh perspective on how information is encoded in DNA and new tools for building sustainable biotechnologies.

Despite being invisible to the naked eye, microorganisms are integral for our survival. They operate using DNA, often referred to as the code of life. DNA encodes numerous tools that could be useful to us, but we currently lack a complete understanding of how to interpret DNA sequences.

Matthew Tarnowski, first author and a PhD student in Bristol’s School of Biological Sciences, said: “Understanding the microbial world is tricky. While reading a microbe’s DNA with a sequencer gives us a window into the underlying code, you still need to read a lot of different DNA sequences to understand how it actually works. It’s a bit like trying to learn a new language, but from only a few small fragments of text.”

To tackle this problem, the Bristol team focused on how the information encoded in DNA is read, and specifically, how the flow of cellular processes along DNA are controlled. These biological information flows orchestrate many of the core functions of a cell and an ability to shape them would offer a way to guide cellular behaviors.

Taking inspiration from nature, where it is known that flows on DNA are often complex and interwoven, the team focused on how these flows could be regulated by creating “valves” to tune the flow from one region of DNA to another.

Suicide Attempts on the Rise, But Help is Hard to Get

The rate of suicidal behavior among Americans increased from 2008 to 2019, but usage of mental health services didn’t budge, reports a team led by UConn Health. The results, reported in JAMA Psychiatry, show that people need help to overcome existing barriers to care.

Suicide overall is still rare, but the rate of people attempting it in the US increased from 2008 to 2019, despite an improving economy during that period. A team of researchers including UConn Health School of Medicine psychiatric epidemiologist Greg Rhee looked at data from a survey done by the National Institutes of Health and Substance Abuse and Mental Health Services Administration of 484,732 people across the US.

The survey found rates of attempted suicide rose by 1.8 times from 2008 to 2019 in young people aged 18-25. It also rose among people struggling with substance abuse. Suicide attempts are the single most important risk factor for suicide; the rate of suicide is 100 times greater among people who’ve already made the attempt in the past year compared to the general population. Getting people mental health services soon after a suicide attempt is one of the most effective ways to help them.

The survey also asked respondents if there was a time in the last 12 months when they needed mental health services but did not receive them, and if so, why.

Arthritis-related gene also regenerates cartilage in joints and growth plates

Spine from a healthy mouse (left) and a mouse with
genetically disrupted cartilage progenitor cells 
Image by Dawei Geng and Tea Jashashvili

The IL-6 family of proteins has a bad reputation: it can promote inflammation, arthritis, autoimmune disease and even cancer. However, a new USC-led study published in Communications Biology reveals the importance of IL-6 and associated genes for maintaining and regenerating cartilage in both the joints and in the growth plates that enable skeletal growth in children.

“We show, for the first time, that the IL-6 family, previously almost exclusively associated in the musculoskeletal field with arthritis, bone and muscle loss, and other chronic inflammatory diseases, is required for the maintenance of skeletal stem and progenitor cells, and for the healthy growth and function of the joints and spine,” said the study’s corresponding author Denis Evseenko, who is the J. Harold and Edna LaBriola Chair in Genetic Orthopedic Research, and an associate professor of orthopaedic surgery, and stem cell biology and regenerative medicine at USC. “Our study establishes a link between inflammation and regeneration, and may explain why stem and progenitors are exhausted in chronic inflammation.”

In the study, first author Nancy Q. Liu from USC and her colleagues took a close look at a key gene activated by IL-6: STAT3. In both lab-grown human cells and in mice, the scientists demonstrated that STAT3 is critical for the proliferation, survival, maturation and regeneration of cartilage-forming cells in the joints and growth plates. When the gene ceased to function, cartilage-forming cells became increasingly dysfunctional over time, resulting in smaller body size, prematurely fused growth plates, underdeveloped skeletons and mildly degenerated joint cartilage.

Mice experienced the same issues when they lacked a protein called glycoprotein 130 (gp130), which all IL-6 proteins use to activate Stat3. Deactivating another gene Lifr, which encodes a protein that works with gp130 to recognize one of the IL-6 proteins called Lif, produced similar but milder skeletal and cartilage changes.

Making the invisible visible: tracing the origins of plants in West African cuisine

Excavated Nok vessels are cleaned and photographed at the Janjala research station, shown in the picture: Dr Gabriele Franke, Goethe University
Credit: Peter Breunig

A team of scientists, led by the University of Bristol, in co-operation with colleagues from Goethe University, Frankfurt, has uncovered the first insights into the origins of West African plant-based cuisine, locked inside pottery fragments dating back some 3,500 years ago.

West African cuisine has long been known for its distinct ingredients and flavors, often enhanced by the addition of a large and diverse range of plant foods.

A traditional meal comprises a starchy staple cooked in a pot, served with a sauce prepared from vegetables, fish and/or meat, often accompanied by pulses.

These starchy staples include root crops such as yams, cassava, sorghum, pearl millet and maize. In the northern Sahel and savanna zones, pearl millet is mainly prepared as porridge, while in the southern forest zone, a pounded mash from tuber crops such as yam, called fufu, is the major starch-rich element.

Excavating Nok terracotta pottery vessel at Ifana 3 site
Credit: Peter Breunig

Indigenous vegetables, eaten at almost every West African meal, include eggplant, pumpkin and watermelon, okra (used as a thickener for soups and stews), as well as a staggering variety of both farmed and foraged green leafy vegetables, little known or used outside of the African continent.

These include leaves from the amaranth, roselle and baobab tree. However, investigating the origin of vegetables and leafy greens is difficult as they do not generally survive over archaeological timescales.

The Bristol team carried out chemical analysis of more than 450 prehistoric potsherds from the Central Nigerian Nok culture to investigate what foods they were cooking in their pots. The Nok people are known for their remarkable large-scale terracotta figurines and early iron production in West Africa, around the first millennium BC.