Tales from the Crypt: Penn Study on Gut Cell Regeneration Reconciles Long-Standing Research Controversy
PHILADELPHIA - The lining of the intestine regenerates itself every few days as compared to say red blood cells that turn over every four months. The cells that help to absorb food and liquid that humans consume are constantly being produced. The various cell types that do this come from stem cells that reside deep in the inner recesses of the accordion-like folds of the intestines, called villi and crypts.
But exactly where the most important stem cell type is located -- and how to identify it -- has been something of a mystery. In fact, two types of intestinal stem cells have been proposed to exist but the relationship between them has been unclear. One type of stem cell divides slowly and resides at the sides of intestinal crypts. The other divides much more quickly and resides at the bottom of the crypts.
Some researchers have been proponents of one type of stem cell or the other as the "true" intestinal stem cell. Recent work published this week in Science from the lab of Jonathan Epstein, MD, chairman of the Department of Cell and Developmental Biology from the Perelman School of Medicine at the University of Pennsylvania, may reconcile this controversy. The findings suggest that these two types of stem cells are related. In fact, each can produce the other, which surprised the researchers.
"We actually began our studies by looking at stem cells in the heart and other organs," Epstein said. "In other tissues in the body, slowly dividing cells can sometimes give rise to more rapidly dividing stem cells that are called to action when tissue regeneration is required. Our finding that this can happen in reverse in the intestine was not expected."
Nanoparticle blueprints reveal path to smarter medicines
New research involving Penn Engineering shows detailed variation in lipid nanoparticle size, shape, and internal structure, and finds that such factors correlate with how well they deliver therapeutic cargo to a particular destination.
A generous gift from alumni Glenn and Amanda Fuhrman brings the work of internationally acclaimed artist Jaume Plensa to the University of Pennsylvania. The latest addition to the Penn Art Collection expands Philadelphia's public art.
A massive chunk of ice, a new laser, and new information on sea-level rise
For nearly a decade, Leigh Stearns and collaborators aimed a laser scanner system at Greenland’s Helheim Glacier. Their long-running survey reveals that Helheim’s massive calving events don’t behave the way scientists once thought, reframing how ice loss contributes to sea-level rise.
