Benefits of “Zombie” Cells: Senescent Cells Aid Regeneration in Salamanders

The salamander species studied by the Yun group: a red spotted newt Notophthalmus viridescens.
Photo Credit: Dr. Maximina Yun

Scientists show that so-called senescent cells, i.e., cells that have permanently stopped dividing, boost production of new muscle cells to enhance regeneration of lost limbs in salamanders.

Senescent cells, often referred to as "zombie" cells, have long been associated with aging and disease. However, a new study from the Center for Regenerative Therapies Dresden (CRTD) at TU Dresden adds to a growing body of evidence that not all senescent cells are harmful. The study led by Dr. Maximina Yun shows that these cells can play a beneficial role in regeneration. Her team found that senescent cells boost muscle formation in regenerating salamander limbs. Their findings reveal a new role for senescent cells and expand the understanding of the early events in the regeneration process. The research was published in the journal Aging Cell.

Senescent cells are cells that have permanently stopped dividing in response to cellular stress but have not died. As organisms age, the number of senescent cells in the body increases. This accumulation is currently considered one of the hallmarks of aging and has been linked to a variety of diseases, including cancer. However, the true nature of these cells may be more complex and context-dependent.

Apes may have evolved upright stature for leaves, not fruit, in open woodland habitats

Artistic rendering of the open woodland habitat reconstruction at Moroto II with Morotopithecus bishopi vertically climbing with infant on back and juvenile below. Active volcano (Mount Moroto) is in background. Fossil relative of an elephant (Prodeinotherium) is foraging in center back.
Illustration Credit: Corbin Rainbolt

Anthropologists have long thought that our ape ancestors evolved an upright torso in order to pick fruit in forests, but new research from the University of Michigan suggests a life in open woodlands and a diet that included leaves drove apes’ upright stature.

The findings shed light on ape origins and push back the origin of grassy woodlands from between 7 million and 10 million years ago to 21 million years ago in equatorial Africa, during the Early Miocene.

Fruit grows on the spindly peripheries of trees. To reach it, large apes need to distribute their weight on branches stemming from the trunk, then reach out with their hands toward their prize. This is much easier if an ape is upright because it can more easily grab onto different branches with its hands and feet. If its back is horizontal, then its hands and feet are generally underneath the body, making it much harder to move outward to the smaller branches of a tree—especially if the ape is large bodied.

AI Tool Predicts Colon Cancer Survival, Treatment Response

New AI tool accurately predicts both overall survival and disease-free survival after colorectal cancer diagnosis.
Image Credit: bodymybody

A new artificial intelligence model designed by researchers at Harvard Medical School and National Cheng Kung University in Taiwan could bring much-needed clarity to doctors delivering prognoses and deciding on treatments for patients with colorectal cancer, the second deadliest cancer worldwide.

Solely by looking at images of tumor samples — microscopic depictions of cancer cells — the new tool accurately predicts how aggressive a colorectal tumor is, how likely the patient is to survive with and without disease recurrence, and what the optimal therapy might be for them.

Having a tool that answers such questions could help clinicians and patients navigate this wily disease, which often behaves differently even among people with similar disease profiles who receive the same treatment — and could ultimately spare some of the 1 million lives that colorectal cancer claims every year.

Study reveals how pollinators cope with plant toxins

Photo Credit: Dustin Humes

Pollinators such as honeybees produce special enzymes that detoxify defense chemicals produced by plants, new research shows.

Many plants produce alkaloids as protection against herbivores, and these toxins are also found in their nectar and pollen.

The new study, by the University of Exeter and Bayer AG, examined the genes of several species in a group called Hymenoptera – insects including bees, wasps, ants and sawflies that share a common ancestor about 280 million years ago.

Remarkably, all the species tested produce the same group of enzymes (the CYP336 family of cytochrome P450 enzymes) to tackle alkaloid toxins.

“These species differ greatly, but one thing they share is this ability to detoxify alkaloids,” said Dr Angie Hayward, from Exeter’s Penryn Campus in Cornwall.

Scientists develop new way to measure wind

Photo Credit: Zbynek Burival

Using data from two NOAA satellites, University of Arizona researchers developed an algorithm for measuring wind via water vapor.

Wind speed and direction provide clues for forecasting weather patterns. In fact, wind influences cloud formation by bringing water vapor together. Atmospheric scientists have now found a novel way of measuring wind – by developing an algorithm that uses data from water vapor movements. This could help predict extreme events like hurricanes and storms.

A study published by University of Arizona researchers in the journal Geophysical Research Letters provides, for the first time, data on the vertical distribution of horizontal winds over the tropics and midlatitudes. The researchers got the water vapor movement data by using two operational satellites of the National Oceanic and Atmospheric Administration, or NOAA, the federal agency for weather forecasting.

Wind brings everything else in the atmosphere together, including clouds, aerosols, water vapor, precipitation and radiation, said Xubin Zeng, co-author of the study and the director of the Climate Dynamics and Hydrometeorology Collaborative at UArizona. But it has remained somewhat elusive.

How did Earth get its water?

Stock photo

For decades, what researchers knew about planet formation was based primarily on our own Solar System. However, the explosion of exoplanet research over the past decade informed a new approach to modeling the Earth’s embryonic state.

Our planet’s water could have originated from interactions between the hydrogen-rich atmospheres and magma oceans of the planetary embryos that comprised Earth’s formative years, according to new work from Carnegie Science’s Anat Shahar and UCLA’s Edward Young and Hilke Schlichting. Their findings, which could explain the origins of Earth’s signature features, are published in Nature.

For decades, what researchers knew about planet formation was based primarily on our own Solar System. Although there are some active debates about the formation of gas giants like Jupiter and Saturn, it is widely agreed upon that Earth and the other rocky planets accreted from the disk of dust and gas that surrounded our Sun in its youth.

As increasingly larger objects crashed into each other, the baby planetesimals that eventually formed Earth grew both larger and hotter, melting into a vast magma ocean due to the heat of collisions and radioactive elements. Over time, as the planet cooled, the densest material sank inward, separating Earth into three distinct layers—the metallic core, and the rocky, silicate mantle and crust.

ORNL, NOAA launch new supercomputer for climate science research

Photo Credit: Genevieve Martin/ORNL

Oak Ridge National Laboratory, in partnership with the National Oceanic and Atmospheric Administration, is launching a new supercomputer dedicated to climate science research. The new system is the fifth supercomputer to be installed and run by the National Climate-Computing Research Center at ORNL.

The NCRC was established in 2009 as part of a strategic partnership between NOAA and the U.S. Department of Energy and is responsible for the procurement, installation, testing and operation of several supercomputers dedicated to climate modeling and simulations. The goal of the partnership is to increase NOAA’s climate modeling capabilities to further critical climate research. To that end, the NCRC has installed a series of increasingly powerful computers since 2010, each of them formally named Gaea. The latest system, also referred to as C5, is an HPE Cray machine with over 10 petaflops — or 10 million billion calculations per second — of peak theoretical performance — almost double the power of the two previous systems combined.

The brain’s support cells may play a key role in OCD

An astrocye from the striatum
Image Credit: Joselyn Soto

A type of cell usually characterized as the brain’s support system appears to play an important role in obsessive-compulsive disorder-related behaviors, according to new UCLA Health research published April 12 in Nature.

The new clue about the brain mechanisms behind OCD, a disorder that is incompletely understood, came as a surprise to researchers. They originally sought to study how neurons interact with star-shaped “helper” cells known as astrocytes, which are known to provide support and protection to neurons.

However, scientists are still trying to understand the apparent role these complex cells play in psychiatric and neurodegenerative diseases.

By studying the proteins expressed by neurons and astrocytes in mice, UCLA researchers found a protein associated with OCD and repetitive behaviors in neurons was also found in astrocytes. The discovery suggests therapeutic strategies targeting astrocytes and neurons may be useful for OCD and potentially other brain disorders.

Scientists Trace Key Innovation in Our Camera-like Vision to Bacteria

Photo Credit: Colin Lloyd

Discovery comes to light with evidence that vertebrates acquired a special protein from bacteria more than 500 million years ago

Humans and other organisms with backbones come equipped with an evolutionary marvel: eyes that function like cameras to provide a finely tuned visual system. Due to its complexity, Charles Darwin described the eye as one of the greatest potential challenges to his theory of natural selection through incremental evolutionary steps.

A notable difference between vertebrate and invertebrate vision is rooted in a unique protein responsible for the specialization of cells that are critical for vision. Mutations in the protein have been known to cause a variety of diseases such as retinitis pigmentosa, but its evolutionary origin has remained elusive with no obvious genetic precursor.

Scientists track evolution of microbes on the skin’s surface

An SEM image showing four yellow-colored, spheroid shaped, Staphylococcus aureus bacteria.
Image Credit: National Institute of Allergy and Infectious Diseases (NIAID)

Human skin is home to millions of microbes. One of these microbes, Staphylococcus aureus, is an opportunistic pathogen that can invade patches of skin affected by eczema, also known as atopic dermatitis.

In a new study, researchers at MIT and other institutions have discovered that this microbe can rapidly evolve within a single person’s microbiome. They found that in people with eczema, S. aureus tends to evolve to a variant with a mutation in a specific gene that helps it grow faster on the skin.

This study marks the first time that scientists have directly observed this kind of rapid evolution in a microbe associated with a complex skin disorder. The findings could also help researchers develop potential treatments that would soothe the symptoms of eczema by targeting variants of S. aureus that have this type of mutation and that tend to make eczema symptoms worse.

“This is the first study to show that Staph aureus genotypes are changing on people with atopic dermatitis,” says Tami Lieberman, an assistant professor of civil and environmental engineering and a member of MIT’s Institute for Medical Engineering and Science. “To my knowledge, this is the most direct evidence of adaptive evolution in the skin microbiome.”

Lieberman and Maria Teresa García-Romero, a dermatologist and assistant professor at the National Institute of Pediatrics in Mexico, are the senior authors of the study, which appears today in Cell Host and Microbe. Felix Key, a former MIT postdoc who is now a group leader at the Max Planck Institute for Infection Biology, is the lead author of the paper.