"Now we know how it works," said Chan, director of the federally designed Diabetes and Endocrinology Research Center at BCM and chief of the division of endocrinology in BCM's department of medicine. "The answer is adult stem cells."
A gene called neurogenin3 proved critical to inducing cells in the liver to produce insulin on a continuing basis, said Chan and Dr. Vijay Yechoor, assistant professor of medicine-endocrinology and first author of the report that appears in the current issue of the journal Developmental Cell. The research team used a disarmed virus called a vector to deliver the gene to the livers of diabetic mice by a procedure commonly known as gene therapy.
"The mice responded within a week," said Yechoor. The levels of sugar in their blood plummeted to normal and stayed that way for the rest of their normal lives.
The quick response generated more questions as did the length of time that the animals stayed healthy.
They found that there was a two-step response. At first, the neurogenin3 gene goes into the mature liver cells and causes them to make small quantities of insulin – enough to drop sugar levels to normal, said Yechoor.
"This is a transient effect," he said. "Liver cells lose the capacity to make insulin after about six weeks."
However, they found that other cells that made larger quantities of insulin showed up later, clustered around the portal veins (blood vessels that carry blood from the intestines and abdominal organs to the liver).
"They look similar to normal pancreatic islet cells (that make insulin normally)," said Yechoor.
They found that these "islet" cells came from a small population of adult stem cells usually found near the portal vein. Only a few are needed usually because they serve as a safety net in case of liver injury. When that occurs, they quickly activate to form mature liver cells or bile duct cells.
However, neurogenin3 changes their fates, directing them down a path to becoming insulin-producing islet cells located in the liver. The mature liver cell cannot make this change because its fate appears to be fixed before exposure to neurogenin3.
The islet cells in the liver look similar to those made by pancreas after an injury, said Yechoor.
"If we didn't use neurogenin3, none of this would happen," he said. "Neurogenin3 is necessary and sufficient to produce these changes."
Chan cautioned that much more work is needed before similar results could be seen in humans. The gene therapy they undertook in the animals used a disarmed viral vector that could still have substantial toxic effects in humans.
"The concept is important because we can induce normal adult stem cells to acquire a new cell fate. It might even be applicable to regenerating other organs or tissues using a different gene from other types of adult stem cells," he said.
Finding a way to use the treatment in human sounds easier than it is, he said. The environment in which cells grow appears to be an important part of the cell fate determination.
However, he and Yechoor plan to continue their work with the eventual goal of providing a workable treatment for people with diabetes.
Dipali Pathak | EurekAlert!
Gene therapy shows promise for treating Niemann-Pick disease type C1
27.10.2016 | NIH/National Human Genome Research Institute
'Neighbor maps' reveal the genome's 3-D shape
27.10.2016 | International School of Advanced Studies (SISSA)
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
27.10.2016 | Materials Sciences
27.10.2016 | Physics and Astronomy
27.10.2016 | Life Sciences