Stem Cells Differentiated into Insulin-Producing Cells in Mice
Reported: Irina Robu, PhD
Dr. Douglas Melton team from Harvard University funded in part by NIH’s National Institute of Diabetes and Digestive and Kidney Diseases set out to transform stem cells into beta cells that have the potential to replace damaged beta cells. While scientists have been able to change stem cells into insulin-producing cells, these cells don’t have markers that indicate they are beta cells, and they aren’t responsive to glucose.
Since diabetes is a disorder of elevated blood sugars where the body does not harvest enough insulin to meet where the body does not harvest enough insulin to respond properly to the insulin being made. When blood glucose levels rise, beta cells in the pancreas normally make the hormone insulin. Insulin triggers cells throughout the body to take up sugar from the blood. In type 2 diabetes, the most common form, tissues in the body lose their sensitivity to insulin, and pancreatic beta cells can’t make enough insulin to keep glucose levels in check. In type 1 diabetes, the body’s own immune system attacks and destroys beta cells. High blood glucose levels can lead to heart disease, blindness, and other health problems over time.
One approach to treat diabetes is to replace destroyed beta cells. Transplanted human pancreatic cells from deceased donors have been successfully used to treat people with type 1 diabetes. But this method is restricted by the accessibility of donor cells and the side effects of immunosuppression. The other approach is to develop functioning beta cells from stem cells which have the potential to transform into many different cell types. These cells can grow indefinitely in the laboratory and can differentiate, into any cell type found in the body.
In this experiment, the researchers grew a human embryonic stem cell line and 2 human-induced pluripotent stem cell lines in a culture system that allowed them to produce large numbers of cells. The researchers tested more than 150 combinations of over 70 compounds to figure out a method to produce functional human beta cells from the cultured stem cells which when added in exact combinations over a period of several weeks, they transformed human pluripotent stem cells into beta cells that functioned similarly to normal adult beta cells.
The cultured beta cells had specific markers that were found on normal beta cells which displayed changes in calcium levels when exposed to glucose and packaged insulin into granules. However, when transplanted into mice these cells secreted insulin in response to glucose. However, when the cells were transplanted into diabetic mice, abnormally high blood glucose levels lowered. More work is needed to develop these cells for clinical use. However, at this point they can serve as a useful screening tool for diabetes drugs.
SOURCE
http://www.frontlinegenomics.com/news/26168/stem-cells-turned-into-insulin-producing-cells-in-mice/
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