Newly discovered esophagus stem cells grow into transplantable tissue
Plastic tubing taped to a handheld egg-beater could save lives in developing countries, the Royal Society of Chemistry’s journal Lab on a Chip reports. The low-cost centrifuge replacement can separate plasma from blood in minutes, which is used in tests to detect lethal infectious diseases responsible for half of all deaths in developing countries. George
Full Post: $2 egg-beater - low-cost centrifuge replacement - could save lives in developing countries
Researchers at the University of Pennsylvania School of Medicine have discovered stem cells in the esophagus of mice that were able to grow into tissue-like structures and when placed into immune-deficient mice were able to form parts of an esophagus lining.
The investigators report their findings online this month in the Journal of Clinical Investigation.
“The immediate implication is that we’ll have a better understanding of the role of these stem cells in normal biology, as well as in regenerative and cancer biology,” says senior author Anil K. Rustgi, MD, the T. Grier Miller Professor of Medicine and Genetics and Chief of Gastroenterology. “Down the road, we will develop a panel of markers that will define these stem cells and use them in replacement therapy for diseases like gastroesophogeal reflux disease [GERD] and also to understand Barrett’s esophagus, a precursor to esophageal adenocarcinoma and how to reverse that before it becomes cancer.”
Diseases of the esophagus are very common in the United States and worldwide. “Benign forms include GERD and millions are affected,” notes Rustgi.
GERD can sometimes lead to inflammation of the esophagus, called esophagitis. “In some of these cases esophagitis can lead to a swapping of the normal lining of the esophagus with a lining that looks more like the intestinal lining and that’s called Barrett’s esophagus,” explains Rustgi. “This can lead to cancer of the esophagus, which is the fastest rising cancer in the US, increasing by 7 to 8 percent a year.”
The researchers set out to identify and characterize potential stem cells–those with the ability to self renew–in the esophagus to understand normal biology and how injured cells may one day be repaired.
First, they grew mouse esophageal cells they suspected were adult stem cells. Those cells formed colonies that self renewed. These cells then grew into esophageal lining tissue in a three-dimensional culture apparatus. “These tissue culture cells formed a mature epithelium sitting on top of the matrix,” says Rustgi. “The whole construct is a form of tissue engineering.”
The investigators then tested their pieces of esophageal lining in whole animals. When the tissue-engineered patches were transplanted under the skin of immunodeficient mice, the cells formed epithelial structures. Additionally, in a mouse model of injury of the esophagus in a normal mouse, which mimics what happens during acid reflux, green-stained stem cells migrated to the injured lining cells and co-labeled with the repaired cells, indicating involvement of the stem cells in tissue repair and regeneration.
Eventually the researchers will develop genetically engineered mouse models to be able to track molecular markers of esophageal stem cells found in a micorarray study. The group has already developed a library of human esophageal cell lines and is looking for human versions of markers already identified in mice.
“The ultimate goal is to identify esophageal stem cells in a patient, grow the patient’s own stem cells, and inject them locally to replace diseased tissue with normal lining,” says Rustgi.
Researchers at the Salk Institute for Biological Studies have developed a versatile mouse model of glioblastoma-the most common and deadly brain cancer in humans-that closely resembles the development and progression of human brain tumors that arise naturally. “Mouse models of human cancer have taught us a great deal about the basic principles of cancer biology,”
Full Post: A novel glioblastoma mouse model developed
The study, which appears in the December 18 online version of Cell Stem Cell and the January 2009 print edition of the journal, provides proof of principle that alternative sources of stem cells can be created. The team, which included scientists from Scripps Research, Peking University, and the University of California, San Diego, conducted the
Full Post: Scientists develop method for generating novel stem cells
Natural changes in voltage that occur across the membrane of adult human stem cells are a powerful controlling factor in the process by which these stem cells differentiate, according to research published by Tufts University scientists. Tufts doctoral student Sarah Sundelacruz, Professor of Biology Michael Levin, and Chair of Biomedical Engineering David L. Kaplan (corresponding
Full Post: New set of controls for stem cells discovered
One of the most promising new ideas about the causes of cancer, known as the cancer stem-cell model, must be reassessed because it is based largely on evidence from a laboratory test that is surprisingly flawed when applied to some cancers, University of Michigan researchers have concluded. By upgrading the lab test, the U-M scientists
Full Post: Cancer stem-cell model tested by University of Michigan researchers
Children with heart defects may someday receive perfectly-matched new heart valves built using stem cells from their umbilical cord blood, according to research presented at the American Heart Association’s Scientific Sessions 2008. When infants are born with malfunctioning heart valves that can’t be surgically repaired, they rely on replacements from animal tissue, compatible human organ
Full Post: Stem cells from umbilical cord blood may help build new heart valves