Multi-scale imaging confirms protein’s role in neuronal structure, dynamics

A whole, live cell time-lapse image (2.5 min) of a neuron expressing fluorescently tagged actin (green) and cofilin (red).
Credit: Penn State College of Medicine.

Protein structures are typically determined by studying them in their purified form, outside of the busy inner workings of the cell, and because of this, their biological relevance is often called into question. In a new study by Penn State College of Medicine researchers, the long-observed protein structure cofilactin, a form of the filamentous protein actin that contains numerous connections to cofilin proteins, was shown to be a major component of neuronal growth cone filopodia — small dynamic “antennae” at the tips of growing neurons.

“The effects of cofilin on actin structure and its physical properties have been studied for more than 20 years, but now we can confidently see that this structural alteration serves some biological function in the cell,” said Matt Swulius, assistant professor of biochemistry and molecular biology. “We’re still trying to determine the mechanistic details of its function, but we have strong evidence that cofilactin regulates the flexibility of searching filopodia.”

According to Swulius, understanding how filopodial dynamics are controlled at the molecular level could open therapeutic avenues into nerve regeneration as well as some developmental diseases. His lab is studying how the proteins fascin and cofilin function together to regulate the structure and movement of neuronal filopodia as they navigate their environment to eventually form cellular connections.

New Light on Magnetic Massive Stars

Video Credit: Jeffrey C. Chase

Oh, those twinkling, twinkling little stars. They make the night sky seem so peaceful, so idyllic, so quiet. It’s hard to believe that they are actually powerful furnaces, where explosive power, extreme heat and swirling, energized gases make them something more like a hydrogen bomb than anything imagined in that child’s lullaby.

Some of us settle for the wistful bit of that lullaby: “How I wonder what you are.” Others press on with increasingly challenging questions in a lifelong quest to learn, discover and inform the rest of us about what those twinkling little stars really are.

Matt Shultz does that as the Annie Jump Cannon Postdoctoral Fellow at the University of Delaware. Stan Owocki does that as professor of physics and astronomy at UD. With collaborators at UD and around the world, they recently joined forces on three articles printed by the Royal Astronomical Society, pointing to important new discoveries that could change how measurements of stars are done and how their brightness can be predicted.

It started a few years ago. Shultz was minding his astronomy at UD and Paolo Leto, a researcher at the Catania Astrophysical Observatory, was doing the same in Italy. Both were studying magnetic massive stars — a rare variety of bright, hot stars with magnetic fields thousands of times stronger than the sun’s. These stars are emerging as promising laboratories for studying plasmas under extreme conditions, Shultz said.

Ground-breaking number of brown dwarfs discovered

Image of the brown dwarf (in the red circle) discovered around the star HIP 21152, obtained with the Very Large Telescope SPHERE instrument.
Credit: M. Bonavita et al., MNRAS

Brown dwarfs, mysterious objects that straddle the line between stars and planets, are essential to our understanding of both stellar and planetary populations. However, only 40 brown dwarfs could be imaged around stars in almost three decades of searches. An international team led by researchers from the Open University and the University of Bern directly imaged a remarkable four new brown dwarfs thanks to a new innovative search method.

Brown dwarfs are mysterious astronomical objects that fill the gap between the heaviest planets and the lightest stars, with a mix of stellar and planetary characteristics. Due to this hybrid nature, these puzzling objects are crucial to improve our understanding of both stars and giant planets. Brown dwarfs orbiting a parent star from sufficiently far away are particularly valuable as they can be directly photographed – unlike those that are too close to their star and are thus hidden by its brightness. This provides scientists with a unique opportunity to study the details of the cold, planet-like atmospheres of brown dwarf companions.

Evasive quantum phenomenon makes debut in routine tabletop experiment

Researchers recently confirmed the presence of the axial Higgs mode, a particle excitation depicted here as a golden sphere. They used Raman spectroscopy, in which an incoming electric field, shown in blue, was coupled with the particle and subsequently scattered into a different frequency, shown in red.
 Credit: Ioannis Petrides and Prineha Narang/Harvard University

A Quantum Science Center-supported team has captured the first-ever appearance of a previously undetectable quantum excitation known as the axial Higgs mode.

This mode manifests as a low-energy excitation in rare-earth tellurides, a class of quantum materials notable for exhibiting charge density wave, or CDW, interactions. This behavior refers to arrangements of interacting electrons in quantum materials that form specific patterns and correlations.

Unlike the regular Higgs mode, which is produced by a Higgs mechanism that provides mass to fundamental particles in the Standard Model of Particle Physics, the axial Higgs mode is visible at room temperature. This characteristic enables more efficient and cost-effective experiments for manipulating quantum materials for various applications – including next-generation memory storage and opto-electronic devices – which would otherwise require extremely cold temperatures.

The team responsible for these results, which are published in Nature, was led by researchers at Boston College and includes scientists from Harvard University, Princeton University, University of Massachusetts Amherst, Yale University, University of Washington and the Chinese Academy of Sciences.

New delivery method allows slow-release of broader array of peptide drugs in the body

Schwendeman Lab.
Image credit: Michigan Photography

A new study from the University of Michigan describes one of the first entirely new drug delivery microencapsulation approaches in decades.

Microencapsulation in biodegradable polymers allows drugs such as peptide therapeutics to be released over time in the body.

Peptides are molecules in the body that are composed of short chains of amino acids, and include messengers, growth factors and well-known hormones such as insulin. Because of their larger size and structure, peptide drugs are rarely given by mouth and must be injected. Microencapsulation is one way to decrease the time needed between injections.

One slow-release delivery method for peptide drugs is to encapsulate them within the type of resorbable polymers often used as dissolving sutures, said study co-author Steven Schwendeman, professor of pharmaceutical sciences and biomedical engineering.

However, development of polymer dosage forms for delivery of certain peptide drugs has been difficult because the currently available methods to microencapsulate the peptide molecules in the polymer require organic solvents and complex manufacturing.

Altered gene helps plants absorb more carbon dioxide, produce more useful compounds

Hiroshi Maeda

Every day, plants around the world perform an invisible miracle. They take carbon dioxide from the air and, with the help of sunlight, turn it into countless chemicals essential to both plants and humans.

Some of these chemicals, known as aromatic compounds, are the starting material for a wealth of useful medications, such as aspirin and morphine. Yet, many of these chemicals come from fossil fuels because it’s hard to get plants to make enough of them to harvest economically. Others are essential human nutrients and can only be obtained through our food since our bodies are unable to make them.

In new work, scientists at the University of Wisconsin–Madison identified a way to release the brakes on plants’ production of aromatic amino acids by changing, or mutating, one set of genes. The genetic change also caused the plants to absorb 30% more carbon dioxide than normal, without any ill effect on the plants.

If scientists could add a trait like this to crops or drug-producing plants, it could help them produce more chemicals naturally while reducing greenhouse gases in the atmosphere.

“We’ve long been interested in this aromatic amino acid pathway because it’s one of the major plant pathways that transform carbon fixed by photosynthesis into medicines, food, fuels, and materials,” says Hiroshi Maeda, a UW–Madison professor of botany who led the new research. “Now for the first time, we’ve discovered how to regulate the key control knob plants use to turn up production of this pathway.”

Uncovering a novel way to bring to Earth the energy that powers the sun and stars

From left: PPPL physicists Ken Hill, Lan Gao, and Brian Kraus; image of the National Ignition Facility
 Collage courtesy of Kiran Sudarsanan

Scientists at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) has uncovered critical new details about fusion facilities that use lasers to compress the fuel that produces fusion energy. The new data could help lead to the improved design of future laser facilities that harness the fusion process that drives the sun and stars.

Fusion combines light elements in the form of plasma — the hot, charged state of matter composed of free electrons and atomic nuclei — that generates massive amounts of energy. Scientists are seeking to replicate fusion on Earth for a virtually inexhaustible supply of power to generate electricity.

Major experimental facilities include tokamaks, the magnetic fusion devices that PPPL studies; stellarators, the magnetic fusion machines that PPPL also studies and have recently become more widespread around the world; and laser devices used in what are called inertial confinement experiments.

Rapid-fire fast radio burst shows hot space between galaxies

The Five-hundred-meter Aperture Spherical radio Telescope, known as FAST, in Ghizou province, southwest China, where Fast Radio Burst 20190520B was discovered, is considered the spiritual successor to the now-defunct, Cornell-built Arecibo Observatory in Puerto Rico.
Credit: Shami Chatterjee

A rare and persistent rapid-fire fast radio burst source – sending out an occasional and informative cosmic ping from more than 3.5 billion light years away – now helps to reveal the secrets of the broiling hot space between the galaxies.

What excites astronomers about the repeating fast radio bursts (FRBs) – since they only burst once, generally speaking – is that these quick-fire surges provide a pathway for scientists to comprehend the perplexing, mysterious and million-degree intergalactic medium.

This work, “A Repeating Fast Radio Burst Associated with a Persistent Radio Source,” was published June 8 in Nature, by an international group of scientists led by Chinese and Cornell astronomers.

“Examining the intergalactic medium is really hard,” said co-author Shami Chatterjee, Ph.D. ’03, principal research scientist in astronomy in the College of Arts and Sciences. “The intergalactic medium is difficult to probe, which is why fast radio bursts are exciting. The bursts let us study the properties of the intergalactic medium.”

Joining Chatterjee on the Nature paper are James M. Cordes, the George Feldstein Professor of Astronomy (A&S) and Stella K. Ocker, a doctoral student in astronomy.

Human skin can be damaged by exposure to thirdhand smoke and electronic cigarette spills

Prue Talbot (left) and her former graduate student Giovanna Pozuelos.
Credit: UCR/Stan Lim

A University of California, Riverside, study has found that dermal exposure to nicotine concentrations found in thirdhand smoke, or THS, and electronic cigarette spills may damage the skin.

THS, of which nicotine is a major component, is created when exhaled smoke and smoke emanating from the tip of burning cigarettes settles on surfaces such as clothing, hair, furniture, and cars. Not strictly smoke, THS refers to the residues left behind by smoking. Electronic cigarette spills are e-liquid spills that may occur by leaky electronic cigarette products or when consumers and vendors mix e-liquids for refillable electronic cigarettes.

Study results appear in Atmosphere, a journal.

“We found dermal contact with nicotine may impair wound healing, increase susceptibility to skin infections due to a decrease in immune response, and cause oxidative stress in skin cells,” said Giovanna Pozuelos, who graduated earlier this year from UC Riverside with a doctoral degree in cell, molecular, and developmental biology.

The study was performed using EpiDermTM, a 3D model of the human epidermis, and cultured human keratinocytes. Keratinocytes are epidermal cells that produce keratin, the protein found in hair and fingernails. The researchers exposed EpiDermTM for 24 hours to different nicotine concentrations typically found in THS environments and electronic cigarette spills. The researchers then proceeded to identify processes and pathways altered by the exposure. They investigated nicotine’s effect on cellular organelles, mitochondria, and peroxisomes — organelles containing enzymes involved in many metabolic reactions.

Zinc Found to Play an Important Role in Lung Fibrosis

Paul Noble, MD

Cedars-Sinai research shows targeting a newly identified molecular Pathway with a common mineral could help reverse lung damage in Idiopathic Pulmonary Fibrosis patients

Investigators from the Women’s Guild Lung Institute at Cedars-Sinai have discovered that zinc, a common mineral, may reverse lung damage and improve survival for patients with a deadly age-related condition known as idiopathic pulmonary fibrosis (IPF).

Their findings, published in The Journal of Clinical Investigation, have the potential to change the landscape of treatment for patients with this disease, which most often affects those over age 50.

“This study has the potential to be a game changer,” said Paul Noble, MD, chair of the Department of Medicine, director of the Women’s Guild Lung Institute and co-senior author of the study. “We identified a root cause of IPF-related lung damage and a potential therapeutic target that might restore the lungs’ ability to heal themselves.”

Idiopathic pulmonary fibrosis, or IPF, affects 100,000 people in the U.S. and has no known cause. The condition, which leads to scarring of the lungs, called fibrosis, and progressive breathing difficulty, has no cure, and most patients die or require a lung transplant within three to five years of diagnosis. The incidence of IPF rises dramatically with age and affects men more often than women.

Through this research, Cedars-Sinai investigators found that stem cells lining the air sacs in the lungs of patients with IPF lose their ability to process zinc, which is known to have a role in the growth of cells and healing damaged tissue.