Previously unknown type of regenerating insulin-producing cell discovered.
Type I diabetes is a disease with two parts, firstly, the beta cells are killed by the body’s own immune system, and then they fail to regenerate. Without these cells, the body loses the ability to control blood glucose, therefore, an effective cure for type I diabetes could involve dealing with the inability of insulin-producing beta cells to regenerate. Now, a study from researchers at the University of California Davis identifies a previously unknown type of regenerating insulin-producing cell. The team state that their study shows a possible new route to regenerating beta cells, giving insight into the basic mechanisms behind healthy metabolism and diabetes. The study is published in the journal Cell Metabolism.
Previous studies show that in both mice and people the islets contain beta cells which detect glucose and secrete insulin, and other cell types including alpha cells that produce glucagon, a hormone which raises blood sugar. The opposite effects of insulin and glucagon enable the body to regulate blood sugars and store nutrients. The accepted dogma has been that new beta cells are generated by other beta cells dividing. The current study identifies a previously unknown type of cell, which looks a lot like an immature beta cell, scattered around the edges of the islets.
The current study shows that these new cells can make insulin, and don’t have receptors to detect glucose, so they can’t function as a full beta cell. Data findings show that these new cells are an intermediate stage in the differentiation of alpha cells into cells which are functionally indistinguishable from conventional beta cells.
The lab explain that this is a new beta cell population in both humans and mice could be a source to replenish beta cells killed off in diabetes. They go on to add that understanding how these cells mature into functioning beta cells could help in developing stem cell therapies for diabetes. They state that this basic understanding of cells in the islets could also help in understanding type II diabetes further, where beta cells become inactive and no longer secrete insulin.
The team surmise they have discovered a population of immature beta cells that are present throughout life, and form from non-beta precursors at a specialized micro-environment at the islet periphery. For the future, the researchers state that by comparing co-existing immature and mature beta cells within healthy islets, the global medical community stands to learn how to mature insulin-expressing cells into functional beta cells.
Source: University of California – Davis