While it is abundantly clear, that the pancreas has some ability to regenerate, it is unclear if the pancreas has a stem cell population or simply makes new cells through cell division. However, a research team from Bundoora, Victoria, Australia has identified what they think is a stem cell from pancreas that can differentiate into insulin-producing beta cells. Such a discovery might means that type diabetics could potentially regrow their beta cells.
This work comes from scientists from the Walter and Eliza Hall Institute. In particular, Ilia Banakh and Len Harison from the institute’s Molecular Medicine division have identified stem cells from the pancreas, and have also developed a technique to differentiate these cells into insulin-producing beta cells.
Patients with type 1 diabetes mellitus make insufficient quantities of the hormone insulin. Insulin is the most important anabolic hormone of the body. Insulin signals to cells to take up glucose and use it, but it also signals to muscles to make muscle proteins and to fat cells to store more fat. Damage to the beta cells in the pancreas causes a decrease in insulin production to point that the body does not have sufficient quantities of insulin to properly control blood sugar levels. Type 1 diabetics must give themselves shots of insulin daily.
This new work by Banakh and Harrison advances recent studies that found cells with stem cell-like characteristics. However, according to Harrison, “But what Dr. Banakh has done is pinpoint the cell of origin of the insulin-producing cells and show that the number of these cells and their ability to turn into insulin-producing cells increases in response to pancreas injury. This is exciting, because it means that the potential to regenerate insulin-producing cells is there in all of us, even as adults.”
Professor Harrison continued: “In the long run, we hope that people with type 1 diabetes might be able to regenerate their own insulin-producing cells. This would mean they could make their own insulin and regain control of their blood sugar levels, curing their diabetes. Of course, this strategy will only work if we can devise ways to overcome the immune attack on the insulin-producing cells, that causes diabetes in the first place.”
This work confirms the presence of a stem cell population in the pancreas. In this study, the authors and their co-workers discovered a so-called “side population” (SP) of cells that have the ability to pump a dye that binds DNA from the cell. Cell with this capability have stem cell-like properties. However, when the pancreas was injured, the number of these side population cells increased substantially (enriched >10-fold). Even though these SP cells expressed neither insulin protein nor RNA, when they were cultured in serum-free culture medium with defined factors, the SP cells grew and differentiated into islet hormone-expressing cells that secreted insulin in response to glucose.
To extend this work, Harrison and Banakh and others transplanted these SP cells into diabetic mice encased in vascularized chambers, and they maintained their insulin-producing capacities.
Thus these SP cells in the adult pancreas expand in response to β cell injury and are a source of β cell progenitors with potential for the treatment of diabetes.