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Molecular basis of DNA cross-linking by bacteria

The relevance of the gut microbiome, the community of microorganisms living in the digestive tract, to human health is a topic of intense interest. However, among the numerous benevolent bacteria living in the gut, there are some species that are harmful to humans.

For example, certain strains of Escherichia coli produce the genotoxin colibactin, which causes DNA damage and is linked with colon cancer. However, the colibactin molecule is complex and unstable, which has made it challenging to elucidate its chemical structure and the mechanism by which it damages DNA. In the culmination of years of research from multiple laboratories, researchers in a new Science study reveal the structure of the active form of colibactin bound to DNA.

The findings go a long way toward explaining the mutation signatures associated with colibactin exposure and provide substantial insight into how colibactin contributes to colorectal carcinogenesis.

Learn more in a new Science Perspective.


The structure of the bacterial genotoxin colibactin bound to DNA shows how it might contribute to cancer risk.

Orlando D. Schärer Authors Info & Affiliations

Scientists Discover Protein That Can Rejuvenate the Aging Immune System

A single blood protein can make aging stem cells act young again. As people age and notice changes like graying hair or reduced muscle strength, their immune system also undergoes shifts. One key change involves the stem cells that give rise to blood and immune cells, which can accumulate mutatio

Machine learning model predicts protein binding on gold nanoclusters

Researchers in the Nanoscience Center at the University of Jyväskylä, Finland, have developed a pioneering computational model that could expedite the use of nanomaterials in biomedical applications. The study presented the first generalizable machine-learning framework capable of predicting how proteins interact with ligand-stabilized gold nanoclusters, materials widely employed in bioimaging, biosensing, and targeted drug delivery.

The adsorption of proteins onto nanomaterial surfaces is fundamental to many biological applications, including bioimaging and biosensing to targeted drug delivery. Gold nanoclusters, in particular, have attracted attention thanks to their biocompatibility and tunable optical properties. Yet existing studies that predict how proteins interact with these ligand-protected nanostructures often focus on isolated cases, leaving researchers without a unified model to guide design.

“This gap has created a clear need for general, scalable models capable of capturing the underlying rules of protein–nanocluster binding,” specifies Postdoctoral Researcher Brenda Ferrari from the University of Jyväskylä

Microgel-based antioxidant system advances biohybrid brain research

Researchers have unveiled a breakthrough technology that could transform the way scientists build and study lab-grown brain tissue models. The innovation, called Cellular RedOx Spreading Shield (CROSS), delivers long-lasting antioxidant protection to stem cells, enabling the reliable production of high-quality extracellular vesicles (EVs) that strengthen neuron-glia networks.

The study, published in the journal Advanced Functional Materials, was led by University of Illinois Urbana-Champaign chemical and biomolecular engineering professor Hyunjoon Kong and chemistry professor Hee Sun Han, and performed by Ryan Miller, currently a post-doctoral fellow at Georgia Tech.

Jonghwi Lee, in the chemical engineering department at Chung-Ang University in South Korea, and Young Jun Kim at the Korean Institute of Science and Technology–Europe, collaborated on the project.

Protein unties tangled DNA linked to hotspots of cancer mutations

New research published in Nature Communications has linked a normal cellular process to an accumulation of DNA mutations in cancer and identified cancer-driving mutations in an underexplored part of the genome.

Led by Dr. Jüri Reimand of the Ontario Institute for Cancer Research (OICR), the study centers around a protein called TOP2B, part of a family of enzymes that serve an important function in cells and are targets of common cancer chemotherapies.

Strands of DNA are long and complex, and they often get looped and tangled. When that happens, TOP2B and other topoisomerase proteins make cuts to DNA strands to help untangle and repair them. But Reimand and colleagues found many genetic mutations present at the sites of these cuts.

Watch: Vine-like robot lifts delicate cargo — including human bodies

Although they’re constantly improving, robots aren’t necessarily known for their gentle touch. A new robotic system from MIT and Stanford takes a unique stab at changing that, with a robot that uses vine-like tendrils to do its lifting.

The system the engineers developed consists of a series of pneumatic tubes that deploy from a pressurized box on one side of a robotic arm, use air pressure to snake under or around a specific object, then rejoin the arm on the other side where they are clamped in place. Once clamped, the arm itself can move, or the tube can be wound up to lift or rotate the object in its grasp. The ability to deploy the tubes and then recapture them is the real breakthrough here, improving on previous vine-based robots by allowing the system to close its own loops.

“People might assume that in order to grab something, you just reach out and grab it,” says study co-author Kentaro Barhydt, from MIT’s Department of Mechanical Engineering. “But there are different stages, such as positioning and holding. By transforming between open and closed loops, we can achieve new levels of performance by leveraging the advantages of both forms for their respective stages.”

New AI technology can provide rapid and reliable dementia diagnosis

Researchers at Örebro University have developed two new AI models that can analyse the brain’s electrical activity and accurately distinguish between healthy individuals and patients with dementia, including Alzheimer’s disease.

“Early diagnosis is crucial in order to be able to take proactive measures that slow down the progression of the disease and improve the patient’s quality of life,” says Muhammad Hanif, researcher in informatics at Örebro University.

A Possible Role of Intestinal Microbiota in the Pathogenesis of Ankylosing Spondylitis

Ankylosing spondylitis (AS) is a chronic inflammatory disease primarily affecting the sacroiliac joints and the spine, for which the pathogenesis is thought to be a result of the combination of host genetic factors and environmental triggers. However, the precise factors that determine one’s susceptibility to AS remain to be unraveled. With 100 trillion bacteria residing in the mammalian gut having established a symbiotic relation with their host influencing many aspects of host metabolism, physiology, and immunity, a growing body of evidence suggests that intestinal microbiota may play an important role in AS. Several mechanisms have been suggested to explain the potential role of the microbiome in the etiology of AS, such as alterations of intestinal permeability, stimulation of immune responses, and molecular mimicry.

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