Researchers from North Carolina State University have confirmed that a species of Rickettsia first seen in dogs in 2018 is a new species of bacteria. The new species, dubbed Rickettsia finnyi, is associated with symptoms similar to those of Rocky Mountain spotted fever (RMSF) in dogs, but has not yet been found in humans.
Rickettsia pathogens are categorized into four groups; of those, the spotted-fever group Rickettsia (which is transmitted by ticks) is the most commonly known and contains the most identified species. There are more than 25 species of tick-borne, spotted-fever group Rickettsia species worldwide, with R. rickettsii—which causes RMSF—being one of the most virulent and dangerous.
Cancer cells with a cell nucleus that is easily deformed are more sensitive to drugs that damage DNA. These are the findings of a new study by researchers at Linköping University in Sweden. The results may also explain why combining certain cancer drugs can produce the opposite of the intended effect. The study has been published in the journal Nature Communications.
A few years ago, a new type of drug was introduced that exploits deficiencies in cancer cells’ ability to repair damage to their DNA. These drugs, called PARP1 inhibitors, are used against cancers that have mutations in genes involved in DNA repair, such as the breast cancer gene 1 (BRCA1).
This gene has such a central role in the cell’s ability to repair serious DNA damage that mutations in it greatly increase the risk of developing cancer, often at a young age. The risk is so high that some women with a mutated BRCA1 gene choose to have their breasts and ovaries surgically removed to prevent cancer.
Purdue University researchers found that a subset of epidermal cells in plant leaves serves as early responders to chemical cues from bacterial pathogens and communicate this information to neighbors through a local traveling wave of calcium ions. The properties of this local wave differ from those generated when epidermal cells are wounded, suggesting that distinct mechanisms are used by plants to communicate specific types of pathogen attack, the team reported Dec. 2 in Science Signaling.
The new work from Purdue’s Emergent Mechanisms in Biology of Robustness Integration and Organization (EMBRIO) Institute highlights the importance of calcium ion signatures or patterns in the cytoplasm of cells. Plants and animals use calcium ions to transmit biologically critical sensory information within single cells, across tissues and even between organs.
“When a bacterium infects plant material, or when a fungus tries to invade plant tissue, cells and tissues recognize the presence of an attacker,” said Christopher Staiger, a professor in the Department of Botany and Plant Pathology and Distinguished Professor of Biological Sciences. “They recognize both chemical and mechanical cues. This study is largely about how the chemical cues are sensed.”
One of the hallmarks of cancer cells is their ability to evade apoptosis, or programmed cell death, through changes in protein expression. Inducing apoptosis in cancer cells has become a major focus of novel cancer therapies, as these approaches may be less toxic to healthy tissue than conventional chemotherapy or radiation. Many chemical agents are currently being tested for their ability to trigger apoptosis, and researchers are increasingly exploring light-activated molecules that can be precisely targeted to tumor sites using lasers, sparing surrounding healthy tissue.
Cancer cells have mitochondria that supply energy for rapid growth and division, but an overly alkaline environment is thought to disrupt mitochondrial function, leading to apoptosis.
A microbial protein called Archaerhodopsin-3 (AR3) may hold the key to alkalinity-induced apoptosis. When exposed to green light, AR3 pumps hydrogen ions out of the cell, increasing alkalinity, disrupting cellular functions, and eventually inducing apoptosis.
Background and ObjectivesSpinal muscular atrophy 5q (SMA) is a motor neuron disorder caused by recessive pathogenic variants in the SMN1 gene, which encodes the survival motor neuron (SMN) protein. While the majority of patients with SMA exhibit…
The asteroid Bennu continues to provide new clues to scientists’ biggest questions about the formation of the early solar system and the origins of life. As part of the ongoing study of pristine samples delivered to Earth by NASA’s OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer) spacecraft, three new papers published Tuesday by the journals Nature Geosciences and Nature Astronomy present remarkable discoveries: sugars essential for biology, a gum-like substance not seen before in astromaterials, and an unexpectedly high abundance of dust produced by supernova explosions.
Scientists led by Yoshihiro Furukawa of Tohoku University in Japan found sugars essential for biology on Earth in the Bennu samples, detailing their findings in the journal Nature Geoscience. The five-carbon sugar ribose and, for the first time in an extraterrestrial sample, six-carbon glucose were found. Although these sugars are not evidence of life, their detection, along with previous detections of amino acids, nucleobases, and carboxylic acids in Bennu samples, show building blocks of biological molecules were widespread throughout the solar system.
For life on Earth, the sugars deoxyribose and ribose are key building blocks of DNA and RNA, respectively. DNA is the primary carrier of genetic information in cells. RNA performs numerous functions, and life as we know it could not exist without it. Ribose in RNA is used in the molecule’s sugar-phosphate “backbone” that connects a string of information-carrying nucleobases.
Cornell scientists have discovered a potentially transformative approach to manufacturing one of the world’s most widely used chemicals—hydrogen peroxide—using nothing more than sunlight, water and air. The research is published in the journal Nature Communications.
“Currently, hydrogen peroxide is made through the anthraquinone process, which relies on fossil fuels, produces chemical waste and requires transport of concentrated peroxide—all of which have safety and environmental concerns,” said Alireza Abbaspourrad, associate professor of Food Chemistry and Ingredient Technology in the Department of Food Science in the College of Agriculture and Life Sciences, and corresponding author of the research.
Hydrogen peroxide is ubiquitous in both industrial and consumer settings: It bleaches paper, treats wastewater, disinfects wounds and household surfaces, and plays a key role in electronics manufacturing. Global production runs into the millions of tons each year. Yet today’s process depends almost entirely on a complex method involving hazardous intermediates and large-scale central chemical plants.
Scientists in Melbourne have discovered how tiny electrical pulses can steer stem cells as they grow, opening the door to new improved ways of creating new tissues, organs, nerves and bones.
Dr. Amy Gelmi, a senior lecturer at RMIT University’s School of Science, led the work using advanced atomic force microscopy to track how stem cells change their structure when exposed to electrical stimulation.
The study reveals, for the first time, how living stem cells physically respond to external signals in real time—reshaping themselves within minutes and setting off changes that influence what type of cell they eventually become. The paper is published in the journal Advanced Materials Interfaces.
At European XFEL, researchers have observed in detail how the vital iron protein ferritin makes its way in highly dense environments—with implications for medicine and nanotechnology.
Inside biological cells, there is a dense crowd where millions of proteins move side by side, bump into each other or temporarily accumulate. At the same time, these proteins often have to fulfill important tasks at short notice. How exactly the proteins move in this confined space has been difficult to track until now.
An international research team led by Anita Girelli and Fivos Perakis, both from Stockholm University, has now used the European XFEL X-ray laser in Schenefeld near Hamburg to take a closer look at these movements—and discovered a surprising pattern. The results are published in Nature Communications.
