The Discovery of a Fat-Filled Cell Reveals Why Noses Are Springy
ABOVE: A newly discovered type of cartilage tissue makes tips of noses and ears bouncy and pliable. The fat-laden cells in this tissue are like individual bubbles in bubble wrap. ©iStock, ediebloom
T he smooth functioning of the body’s joints, the flexibility of the ears and nose, and the shaping of bones are all made possible by the skeletal tissue known as cartilage.1 According to popular medical textbooks, cartilage is made up of only one type of specialized cell called a chondrocyte, which is small and secretes large quantities of extracellular matrix, giving cartilage its biomechanical properties.2 But now, new research makes these textbooks outdated.
More than a decade ago, while studying fat cells in the mouse ear skin, Maksim Plikus and his colleagues observed a puzzling pattern in dye uptake. “There were some fat cells that stained, which were the true adipocytes,” said Plikus, a developmental biologist at the University of California, Irvine. “Then there was another group of fat cells that didn't [stain], no matter which marker.” Initially, he thought these odd adipocytes could simply be a type that stubbornly resisted dyes. However, upon digging deeper, Plikus realized that they were a completely new type of fat-laden cartilage cells that formed the pliable lipo-cartilage in body parts like the nose, ear and throat. “At first we really had to pinch ourselves because it made no sense,” Plikus exclaimed.
They called these newly-identified cells lipochondrocytes (LCs), and after a decade of investigation into their structure and function, the team published their report today in Science.3 These findings will expand the current understanding of skeletal biomechanics and open new avenues in regenerative medicine.
