Weight loss may 'rejuvenate' fat tissue in the body - Live Science

)The immortal jellyfish is capable of winding back its lifecycle to become young again. Scientists are unlocking its cellular secrets to find ways human cells could rejuvenate too. The tiny translucent jellyfish Turritopsis dohrnii is surprisingly hard to kill. The marine biologist Maria Miglietta of Texas A&M University at Galveston has cut them, boiled them, starved them, overloaded their tanks with salt or plopped them in fresh water – but the nifty creatures seem to cheat death every time. Under duress, they stop in their tracks and fall to the bottom of their tank. Then something astonishing happens: the animals transform into balls of cells that bear no resemblance to the tentacled umbrella shape of adult jellyfish, known as the medusa. Within one to three days, a structure called a polyp – an early jellyfish life stage – buds off from this ball of cells and then grows into a colony, which will eventually sprout new medusae. "From one jellyfish that doesn't die, then you get this colony that can form hundreds more," Miglietta says.

The liver is one of the most remarkable organs in the human body. This multitasking dynamo performs around 500 vital functions, including processing nutrients and filtering out harmful substances in our blood. Despite the chemical toxins it has to contend with on a daily basis, the liver is preternaturally youthful, thanks to its unique ability to regenerate itself. Even the trusty liver isn't immortal, though. As the body starts to age, so too does the liver. And as it declines, it becomes susceptible to various forms of fatty liver disease. But what if there were a way to help restore an aged liver to its youthful state? In a new study published in npj Aging, scientists got a step closer to that very thing, using a compound found in citrus fruits to slow and even reverse signs of liver aging in mice. Your liver, pictured at three years of age.

The sea cucumber study reveals an unusual form of tissue regrowth, with detached fragments continuing to heal, reorganize, and grow for more than three years in natural seawater. Credit: ShutterstockSea cucumber tissue kept growing for more than three years after removal, surviving in seawater teeming with microbes. Like Thing, the disembodied hand in The Addams Family, a severed piece of sea cucumber tissue kept living without the body it came from, prompting scientists to describe the animal as a “real-life zombie.” Weeks after being cut from a tube foot, the fragment appeared to be growing in seawater full of microbes, far from the sterile conditions usually needed to keep tissue cultures alive. Scientists at Memorial University of Newfoundland followed up by placing tissue removed from the feet, main body, and tentacles of three sea cucumbers in flowing seawater. The animals belonged to Psolus fabricii, a cold-water species. Working with collaborators including Rachel Sipler, a senior research scientist at Bigelow Laboratory for Ocean Sciences, the team documented what happened to those fragments in a study published in Science Advances.

Without native tissue in the way, the transplanted human cells multiplied to five times their initial size, grew their own blood vessels, and connected directly to the mice’s spinal cords. Led by first author Kelley Kaganovsky and senior author Sergiu Pașca, the team published the findings in Nature on September 16, 2026. Earlier attempts to integrate human brain tissue faced strict space constraints. In a 2022 study, Pașca’s lab transplanted human cortical organoids — 3D cell clusters grown from stem cells — into newborn rats. The rats’ own neurons matured quickly, capping the human tissue at a third of the cortical hemisphere.

Scientists uncover a cellular survival mechanism that helps severely damaged tissue regenerate and may also reveal why some cancers return after treatment. Tissues such as skin, along with the epithelial layers that cover and line many organs, have a remarkable ability to rebuild themselves after extensive damage. Scientists have known about this response, called compensatory proliferation, for roughly half a century. Yet exactly how cells manage to trigger such dramatic regrowth has remained a mystery.

The largest Tyrannosaurus rex fossils ever discovered belong to a 66-million-year-old apex predator named Scotty. Like many T. rex skeletons, it’s difficult to determine if the specimen was male or female, but Scotty was an unequivocal bruiser. Standing 13-feet-tall at the hip and measuring upwards of 43-feet-long, the Late Cretaceous hunter weighed as much as 19,500 pounds. However, Scotty isn’t simply the biggest T. rex on record. One of its bones still has traces of preserved soft tissue. This is almost never seen in paleontology, as soft tissues degrade due to the ravages of time. The only way to safely examine these delicate remains is through highly sensitive techniques like neutron imaging. But with the help of researchers at the Department of Energy’s (DOE) Oak Ridge National Laboratory (ORNL) in Tennessee, paleontologists recently glimpsed Scotty’s rib and its remaining tissue in unprecedented detail. The results offer some of the first in-depth looks at fossilized dinosaur tissue on a microscopic level.