Proteins team up to fix damaged DNA in human cells

 

Replication protein A (RPA) forms a complex with WASp at replication forks (red) within the nucleus (blue) of a human cell during DNA replication stress.   
Credit: Penn State College of Medicine / Penn State. Creative Commons

DNA replication and repair happens thousands of times a day in the human body and most of the time, people don’t notice when things go wrong thanks to the work of Replication protein A (RPA), the "guardian of the genome." Scientists previously believed this protein ‘hero’ responsible for repairing damaged DNA in human cells worked alone, but a new study by Penn State College of Medicine researchers showed that RPA works with an ally called the WAS protein (WASp) to "save the day" and prevent potential cancers from developing.

The researchers discovered these findings after observing that patients with Wiskott-Aldrich syndrome, or WAS — a genetic disorder that causes a deficiency of WASp — not only had suppressed immune system function, but in some cases, also developed cancer.

Dr. Yatin Vyas, professor and chair of the Department of Pediatrics at Penn State College of Medicine and pediatrician-in-chief at Penn State Health Children’s Hospital, conducted prior research which revealed that WASp functions within an apparatus that is designed to prevent cancer formation. As a result, some cancer patients had tumor cells with a WASp gene mutation. These observations led him to hypothesize that WASp might play a direct role in DNA damage repair.

“WAS is very rare — less than 10 out of every 1 million boys has the condition,” said Vyas, who is also the Children’s Miracle Network and Four Diamonds Endowed Chair. “Knowing that children with WAS were developing cancers and also observing WASp mutations in tumor cells of cancer patients, we decided to investigate whether WASp plays a role in DNA replication and repair.”

Neutrons help track down Mammalian Ancestors

Dr. Michael Schulz at the neutron radiography facility ANTARES.
Image Credit: Bernhard Ludewig, FRM II / TUM

Investigations at Research Neutron Source led to the discovery of a previously unknown animal species.

A team of German and Argentinian researchers has used neutrons in the FRM II research neutron source at the Technical University of Munich (TUM) to identify an animal species that has been extinct for 220 million years. Findings on the new species provide surprising insights into the evolution of mammals.

A long snout, a massive jaw and sharp teeth – these are some features of the newly discovered species Tessellatia bonapartei. It belongs to the group of Cynodontia (which literally translates to “dog teeth”), mammal-like animals from which mammals eventually evolved.

Argentinian researchers found the bones of the roughly mouse-sized cynodont species in the desert-like Talampaya National Park in the west of Argentina. “The bones were very fragile and therefore it was not possible to remove the surrounding rock without risking damaging them”, explains Dr. Aureliano Tartaglione of the research neutron source Heinz Maier-Leibnitz at TUM. He worked on the project with Dr. Leandro Gaetano from CONICET (National Scientific and Technical Research Council in Argentina).

See-through zebrafish

Tracing features in a large 3D electron microscopy dataset reveals a zebrafish blood stem cell (in green) and its surrounding niche support cells, a group photo method that will help researchers understand factors that contribute to blood stem cell health — which could in turn help develop therapies for blood diseases and cancers. 
Image Credit: Keunyoung Kim

For the first time, researchers can get a high-resolution view of single blood stem cells thanks to a little help from microscopy and zebrafish.

Researchers at the University of Wisconsin–Madison and the University of California San Diego have developed a method for scientists to track a single blood stem cell in a live organism and then describe the ultrastructure, or architecture, of that same cell using electron microscopy. This new technique will aid researchers as they develop therapies for blood diseases and cancers.

“Currently, we look at stem cells in tissues with a limited number of markers and at low resolution, but we are missing so much information,” says Owen Tamplin, an assistant professor in UW–Madison’s Department of Cell & Regenerative Biology, a member of the Stem Cell & Regenerative Medicine Center, and a co-author on the new study, which was published Aug. 9 in eLife. “Using our new techniques, we can now see not only the stem cell, but also all the surrounding niche cells that are in contact.”

The niche is a microenvironment found within tissues like the bone marrow that contain the blood stem cells that support the blood system. The niche is where specialized interactions between blood stem cells and their neighboring cells occur every second, but these interactions are hard to track and not clearly understood.

Robot helps reveal how ants pass on knowledge

Ant leading other ant to new nest, known as tandem running.
Credit: Norasmah Basari and Nigel R Franks

The team built the robot to mimic the behavior of rock ants that use one-to-one tuition, in which an ant that has discovered a much better new nest can teach the route there to another individual.

The findings, published in the Journal of Experimental Biology today, confirm that most of the important elements of teaching in these ants are now understood because the teaching ant can be replaced by a machine.

Key to this process of teaching is tandem running where one ant literally leads another ant quite slowly along a route to the new nest. The pupil ant learns the route sufficiently well that it can find its own way back home and then lead a tandem-run with another ant to the new nest, and so on.

Prof Nigel Franks of Bristol’s School of Biological Sciences said: “Teaching is so important in our own lives that we spend a great deal of time either instructing others or being taught ourselves. This should cause us to wonder whether teaching actually occurs among non-human animals. And, in fact, the first case in which teaching was demonstrated rigorously in any other animal was in an ant.” The team wanted to determine what was necessary and sufficient in such teaching. If they could build a robot that successfully replaced the teacher, this should show that they largely understood all the essential elements in this process.

Boeing, Nammo Complete Long-Range Ramjet Artillery Test

Boeing Ramjet 155 projectile
Illustration Credit: Boeing

Boeing [NYSE: BA] and Norwegian defense and aerospace company Nammo have successfully test-fired a ramjet-powered artillery projectile, further demonstrating the viability of one of the U.S. Army’s modernization priorities – long-range precision fires.

During the June 28 test at the Andøya Test Center in Norway, a Boeing Ramjet 155 projectile was fired out of a cannon and its ramjet engine ignited successfully. It demonstrated flight stability with a well-controlled engine combustion process.

Credit: Boeing

“We believe the Boeing Ramjet 155, with continued technology maturation and testing, can help the U.S. Army meet its long-range precision fires modernization priorities,” said Steve Nordlund, Boeing Phantom Works vice president and general manager. “This successful test is evidence that we are making great progress.”

“This is a historic moment for Nammo,” said Nammo Chief Executive Officer Morten Brandtzæg. “The test results demonstrate that ramjets are viable and can fundamentally change the future of artillery.

“We have great confidence in the ramjet concept,” Brandtzæg added. “The test – with all aspects from cannon firing, to the projectile body, fins, and trajectory all functioning perfectly – represents a real technological breakthrough in artillery, and a major success for Boeing, Nammo, and the U.S. Army.”

The long-range test at Andøya follows years of research, development and testing by Boeing and Nammo of ramjet technology, including more than 450 static or short-range tests.

Boeing Phantom Works and Nammo have been working together under a strategic partnership to jointly develop and produce the next generation of boosted artillery projectiles. In July 2019, the Boeing-Nammo team was awarded a contract under the U.S. Army’s XM1155 program to develop and mature the Ramjet 155 projectile. In May 2021, the team was awarded a Phase II technology development contract.

Ramjet 155 uses an engine in which the air drawn in for combustion is compressed solely by the forward motion of the projectile at supersonic speeds. Considered a hybrid between guided artillery and missiles, the program has an objective of a common round design that can be used in L39 and L58 cannons.

The team continues to develop and mature the technology, with further testing and demonstrations planned in the coming months.

Source/Credit: Boeing

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How water turns into ice — with quantum accuracy

Researchers at Princeton University combined artificial intelligence and quantum mechanics to simulate what happens at the molecular level when water freezes. The result is the most complete simulation yet of the first steps in ice “nucleation,” a process important for climate and weather modeling.  

Video by Pablo Piaggi, Princeton University

A team based at Princeton University has accurately simulated the initial steps of ice formation by applying artificial intelligence (AI) to solving equations that govern the quantum behavior of individual atoms and molecules.

The resulting simulation describes how water molecules transition into solid ice with quantum accuracy. This level of accuracy, once thought unreachable due to the amount of computing power it would require, became possible when the researchers incorporated deep neural networks, a form of artificial intelligence, into their methods. The study was published in the journal Proceedings of the National Academy of Sciences.

“In a sense, this is like a dream come true,” said Roberto Car, Princeton’s Ralph W. *31 Dornte Professor in Chemistry, who co-pioneered the approach of simulating molecular behaviors based on the underlying quantum laws more than 35 years ago. “Our hope then was that eventually we would be able to study systems like this one, but it was not possible without further conceptual development, and that development came via a completely different field, that of artificial intelligence and data science.”

The ability to model the initial steps in freezing water, a process called ice nucleation, could improve accuracy of weather and climate modeling as well as other processes like flash-freezing food.

The new approach enables the researchers to track the activity of hundreds of thousands of atoms over time periods that are thousands of times longer, albeit still just fractions of a second, than in early studies.

Car co-invented the approach to using underlying quantum mechanical laws to predict the physical movements of atoms and molecules. Quantum mechanical laws dictate how atoms bind to each other to form molecules, and how molecules join with each other to form everyday objects.

In control of chaos

Assembly line: A different chemical mixture is created in each of the droplets within the "Tubular flow reactor" – under exactly the same boundary conditions.
Image Credit: Empa

Crystals consisting of wildly mixed ingredients - so-called high-entropy materials - are currently attracting growing scientific interest. Their advantage is that they are particularly stable at extremely high temperatures and could be used, for example, for energy storage and chemical production processes. An Empa team is producing and researching these mysterious ceramic materials, which have only been known since 2015.

Nature strives for chaos. That's a nice, comforting phrase when yet another coffee cup has toppled over the computer keyboard and you imagine you could wish the sugary, milky brew back into the coffee cup - where it had been just seconds before. But wishing won't work. Because, as mentioned, nature strives for chaos.

Scientists have coined the term entropy for this effect - a measure of disorder. In most cases, if the disorder increases, processes run spontaneously and the way back to the previously prevailing order is blocked. See the spilled coffee cup. Even thermal power plants, which generate a huge cloud of steam above their cooling tower from a neat pile of wood or a heap of hard coal, operate driven by entropy. Disorder increases dramatically in many combustion processes - and humans take advantage of this, tapping a bit of energy in the form of electricity from the ongoing process for their own purposes.

Hearing Loss in Dogs Associated With Dementia

Image by Chen Vision, licensed under CC BY-NC 2.0

A new study from North Carolina State University explores the connection between hearing loss and dementia in geriatric dogs. The work could aid in both treatment of aging dogs and in understanding the relationship between sensory loss and cognitive function in dogs.

“In humans, we know that age-related hearing loss is estimated to affect one-third of people over age 65,” says Natasha Olby, the Dr. Kady M. Gjessing and Rahna M. Davidson Distinguished Chair in Gerontology at North Carolina State University and corresponding author of the study.

“We also know that the rate of cognitive decline is approximately 30-40% faster in people with age-related hearing loss and that hearing loss is a greater contributor to dementia risk than other factors such as hypertension or obesity. But we don’t understand whether the same holds true for dogs.”

In the study, Olby and colleagues evaluated 39 senior or geriatric dogs. Auditory and cognitive tests were performed on each dog and their owners were asked to fill out two commonly used questionnaires – one focused on cognitive ability and the other on quality of life. Cognitive testing, questionnaire scores and age were compared between hearing groups.

Students Begin Creating Oil-Based Emulsions for Foods

The internship of Ural Federal University students was the beginning of joint work of the Ural universities in the field of biotechnology.
Credit: Elena Kovaleva

It will be done within the framework of a joint project of the Ural Federal University and the South Ural State University

The Ural Federal University and the South Ural State University started cooperation in the field of progressive biotechnologies. This year, four Master's students from Ural Federal University completed an internship at the university in Chelyabinsk under the supervision of researchers from the Laboratory of Synthesis and Analysis of Food Ingredients (School of Medical Biology) of the South Ural State University.

As part of this project, students will be trained to make double emulsions based on oils for their subsequent use in products. A new format of cooperation and joining efforts of two scientific teams will lead to the creation of new technologies in such an important sphere as food production, says Irina Potoroko, Head of SUSU Department of Food and Biotechnology.

As Elena Kovaleva, Professor at the Ural Federal University Department of Technology of Organic Synthesis, notes, Ural Federal University chemists are engaged not only in food technology, but also in industrial technology, developing methods of extracting biologically active substances from food and plant raw materials. The team is ready to accept students interested in internships.

A role for cell ‘antennae’ in managing dopamine signals in the brain

Microscope image of a cultured mouse neuron from the striatum region of the brain labeled with a green fluorescent antibody that detects dopamine receptor 1. The receptor localizes along the cell surface and is enriched in a primary cilium projecting from the cell body. Nuclei are indicated in blue.
 Credit: Image courtesy of Kirk Mykytyn

A historically overlooked rod-like projection present on nearly every cell type in the human body may finally be getting its scientific due: A new study has found that these appendages, called cilia, on neurons in the brain have a key role in ensuring a specific dopamine receptor’s signals are properly received.

The research was conducted in mouse models of a disorder called Bardet-Biedl syndrome, and applies to one of five proteins that regulate dopamine signaling, called dopamine receptor 1. In certain regions of the brain, this receptor can be thought of as an “on” switch that initiates motivated behavior – basically any behavior linked to pursuit of a goal.

The study showed that if the receptor either gets stuck on cilia or never has a chance to localize to these cell “antennae,” messages telling the body to move are reduced.

“There’s something about dopamine receptor 1 needing to get to and from neuronal cilia that’s required for proper signaling,” said lead author Kirk Mykytyn, associate professor of biological chemistry and pharmacology in The Ohio State University College of Medicine. “This is the first demonstration that cilia are important for dopamine receptor 1 signaling.”