Shinya Yamanaka
Stem Cell Science: Taking Aim at Type 1 Diabetes
Posted on by Dr. Francis Collins
Caption: Insulin-producing pancreatic beta cells (green) derived from human embryonic stem cells that have formed islet-like clusters in a mouse. The red cells are producing another metabolic hormone, glucagon, that regulates blood glucose levels. Blue indicates cell nuclei.
Credit: Photo by B. D. Colen/Harvard Staff; Image courtesy of Doug Melton
For most of the estimated 1 to 3 million Americans living with type 1 diabetes, every day brings multiple fingerpricks to manage their blood glucose levels with replacement insulin [1,2]. The reason is that their own immune systems have somehow engaged in friendly fire on small, but vital, clusters of cells in the pancreas known as the islets—which harbor the so-called “beta cells” that make insulin. So, it’s no surprise that researchers seeking ways to help people with type 1 diabetes have spent decades trying a find a reliable way to replace these islets.
Islet replacement has proven to be an extremely difficult research challenge for a variety of reasons, but exciting opportunities are now on the horizon. Notably, a team of researchers, led by Douglas Melton of Harvard University, Cambridge, MA, and partially funded by NIH, reported groundbreaking success just last week in spurring a human embryonic stem cell (hESC) line and two human-induced pluripotent stem (iPS) cell lines to differentiate into the crucial, insulin-producing beta cells. Not only did cells generated from all three of these lines look like human pancreatic beta cells, they functioned like bona fide, glucose-responsive beta cells in a mouse model of type 1 diabetes [3].
The Acid Test: Turning Regular Cells Into Stem Cells
Posted on by Dr. Francis Collins
Caption: A new type of stem cells, called STAPs.
Credit: Haruko Obokata, RIKEN Ctr. for Dev. Biol., Kobe, Japan
Updated July 2, 2014: Since these two papers were published in the journal Nature, more than a dozen research teams have been unable to replicate the STAP findings. On April 1, RIKEN found the main author Haruko Obokata guilty of scientific misconduct. On July 2, Nature accepted requests from all co-authors to retract the papers and published an editorial discussing the retractions.
Taking a 30-minute soak in a bath of acid might not sound like a good thing. But it happens to be the latest—and the most shockingly simple—strategy for creating stem cells.
The powerful appeal of stem cells for science and medicine lies in the fact that they are both self-renewing and pluripotent, which means they can develop into almost any type of cell in the body. Stem cell technology offers an essentially limitless supply of specialized cells to researchers for exploring the fundamentals of biology, screening for new drugs, and developing new ways to regenerate damaged tissue and repair diseased organs.
