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."
The discovery that rapidly cycling gut stem cells can regenerate the quiescent stem cells -- slowly dividing and probably long-lived -- suggests that the developmental pathways in human organs that regenerate quickly like in the gut, skin, blood, and bone, may be more flexible than previously appreciated.
"This better appreciation and understanding may help us learn how to promote the regeneration of tissue-specific adult stem cells that could subsequently help with tissue regeneration," says Epstein. "It may also help us to understand the cell types that give rise to cancer in the colon and stomach."
Co-authors are, all from Penn, Norifumi Takeda, Rajan Jain, Matthew R. LeBoeuf, Qiaohong Wang, and Min Min Lu. The work was funded by the National Heart, Lung and Blood Institute of the National Institutes of Health and by the Penn Institute for Regenerative Medicine.
Penn Medicine is one of the world's leading academic medical centers, dedicated to the related missions of medical education, biomedical research, and excellence in patient care. Penn Medicine consists of the Raymond and Ruth Perelman School of Medicine at the University of Pennsylvania (founded in 1765 as the nation's first medical school) and the University of Pennsylvania Health System, which together form a $4 billion enterprise.
Penn's Perelman School of Medicine is currently ranked #2 in U.S. News & World Report's survey of research-oriented medical schools and among the top 10 schools for primary care. The School is consistently among the nation's top recipients of funding from the National Institutes of Health, with $507.6 million awarded in the 2010 fiscal year.
The University of Pennsylvania Health System's patient care facilities include: The Hospital of the University of Pennsylvania -- recognized as one of the nation's top 10 hospitals by U.S. News & World Report; Penn Presbyterian Medical Center; and Pennsylvania Hospital – the nation's first hospital, founded in 1751. Penn Medicine also includes additional patient care facilities and services throughout the Philadelphia region.
Penn Medicine is committed to improving lives and health through a variety of community-based programs and activities. In fiscal year 2010, Penn Medicine provided $788 million to benefit our community.
Karen Kreeger | EurekAlert!
Something old, something new in the Ocean`s Blue
14.11.2019 | Max-Planck-Institut für Marine Mikrobiologie
AI-driven single blood cell classification: New method to support physicians in leukemia diagnostics
13.11.2019 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Dresden has succeeded in using Selective Electron Beam Melting (SEBM) to...
Carbon nanotubes (CNTs) are valuable for a wide variety of applications. Made of graphene sheets rolled into tubes 10,000 times smaller than a human hair, CNTs have an exceptional strength-to-mass ratio and excellent thermal and electrical properties. These features make them ideal for a range of applications, including supercapacitors, interconnects, adhesives, particle trapping and structural color.
New research reveals even more potential for CNTs: as a coating, they can both repel and hold water in place, a useful property for applications like printing,...
If you've ever tried to put several really strong, small cube magnets right next to each other on a magnetic board, you'll know that you just can't do it. What happens is that the magnets always arrange themselves in a column sticking out vertically from the magnetic board. Moreover, it's almost impossible to join several rows of these magnets together to form a flat surface. That's because magnets are dipolar. Equal poles repel each other, with the north pole of one magnet always attaching itself to the south pole of another and vice versa. This explains why they form a column with all the magnets aligned the same way.
Now, scientists at ETH Zurich have managed to create magnetic building blocks in the shape of cubes that - for the first time ever - can be joined together to...
Quantum-based communication and computation technologies promise unprecedented applications, such as unconditionally secure communications, ultra-precise...
In two experiments performed at the free-electron laser FLASH in Hamburg a cooperation led by physicists from the Heidelberg Max Planck Institute for Nuclear physics (MPIK) demonstrated strongly-driven nonlinear interaction of ultrashort extreme-ultraviolet (XUV) laser pulses with atoms and ions. The powerful excitation of an electron pair in helium was found to compete with the ultrafast decay, which temporarily may even lead to population inversion. Resonant transitions in doubly charged neon ions were shifted in energy, and observed by XUV-XUV pump-probe transient absorption spectroscopy.
An international team led by physicists from the MPIK reports on new results for efficient two-electron excitations in helium driven by strong and ultrashort...
05.11.2019 | Event News
30.10.2019 | Event News
02.10.2019 | Event News
14.11.2019 | Materials Sciences
14.11.2019 | Physics and Astronomy
14.11.2019 | Information Technology