2 School of Medicine, Chang Gung University and Division of Rheumatology, Allergy and Immunology, Chang Gung Memorial Hospital, Taoyuan, Taiwan.
3Imperial Lupus Centre, Imperial College Healthcare NHS Trust, London, United Kingdom.
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Mouse study shows how liraglutide briefly rewires gut bacterial communities
Researchers treated male high-fat-fed mice with liraglutide for 14 days, then tracked fecal bacterial communities after a 7-day washout using 16S rRNA sequencing. Liraglutide shifted the microbiome toward Lactobacillus- and Leptogranulimonas-related taxa while reducing several fermentative taxa, but most changes moved back toward baseline after treatment stopped.
3D DNA mapping in rare immune cells reveals new genes linked with autoimmune disease risk
Our DNA is often pictured as a simple spiral, like a piece of rope held taut. But inside cells, it folds into a complex three-dimensional structure, with 2 meters (6.6 feet) of DNA scrunched like a headphone wire in a pocket. This bundled architecture plays a crucial role in how genes are switched on and off. Understanding these interactions is key to interpreting genetic studies of disease and can help develop targeted treatments.
Genes—the instructions for making proteins—are regulated by two types of DNA regions, called promoters and enhancers. Promoters are located at the start of each gene and directly load the machinery that reads it to produce RNA, a template for making proteins. In contrast, enhancers, which act like “molecular switches” boosting gene activity in the right cell and condition, may be found much further from the genes they control: sometimes many thousands or even millions of DNA letters away. When DNA folds in the 3D space of the cell’s nucleus, these enhancers loop around to physically contact the genes they regulate.
Understanding how enhancers work and which genes they control is particularly important because genome-wide association studies—large-scale efforts comparing the DNA of thousands of people to identify small genetic differences linked to disease—have revealed many genetic variants associated with complex conditions such as Crohn’s disease that sit within these regions. Crohn’s disease is a common form of inflammatory bowel disease, which affects around 1 in 100 people globally and currently has no known cure.
A crossvertebrate brain protein interaction map identifies conserved neural and nonneural complexes
Dang et al. use co-fractionation and immunoprecipitation mass spectrometry to map protein interactions conserved across vertebrate brains. This resource, dubbed VerteBrain, offers insights into brain protein function and new links between proteins and disease, identifying candidate genes and pathways involved in epilepsy, deafness, and developmental disorders.
A temperature dial for more realistic quantum simulations
Scientists from Rice University in the U.S. have developed a way to precisely tune the temperature inside a trapped-ion simulator. The breakthrough means they will be able to run quantum simulations at precise temperatures that better reflect real-world conditions.
Trapped-ion simulators are quantum devices that isolate charged particles inside a sealed vacuum chamber, using electric fields to hold them in place. They mimic and study complex quantum systems, such as chemical reactions or exotic materials, that are too difficult for ordinary computers to calculate.
Temperatures inside these devices are typically kept as close as possible to absolute zero so that thermal motion does not disrupt calculations or cause errors. But researchers lacked a suitable way to set the temperature without accidentally changing how fast the system loses energy. This meant that studies were mostly stuck using absolute zero or uncontrolled high temperatures.
New approach to cleaning the inner walls of a fusion system removes another obstacle to near-endless energy
Fusion systems need inner walls that can withstand extreme heat. One promising solution uses liquid lithium to protect the walls, held like water in a sponge made of the exceptionally strong metal tungsten. An advanced manufacturing process can be used to make tungsten into sponge-like wall tiles with lots of pores for flowing liquid lithium. But this process also leaves the tungsten contaminated with other materials, such as carbon, oxygen or nitrogen.
When exposed to liquid lithium, the carbon and oxygen react to form solids that can plug the holes in the tungsten, preventing the lithium from flowing properly. Even if the tungsten were cleaned at the end of the manufacturing process, it would become recontaminated when the tiles are exposed to air during installation.
Now researchers from the U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL), Princeton University and Pennsylvania State University have found a clever way to clean those tiles after they are installed and sealed inside the fusion system—in vacuum chambers from which the air has been removed. The advance, which uses heat combined with particles from a neon plasma to knock contaminants out of tiles, could help future fusion systems run better with liquid lithium.