Researchers from the Oregon Stem Cell Center in Portland, Oregon have demonstrated the existence of at least four separate subtypes of human insulin-producing beta cells that may be important in the understanding and treatment of diabetes.
“This study marks the first description of several different kinds of human insulin producing beta cells,” said Markus Grompe of the Oregon Stem Cell Center at Oregon Health Science University. “Some of the cells are better at releasing insulin than others, whereas others may regenerate quicker. Therefore, it is possible that people with different percentages of the subtypes are more prone to diabetes. Further understanding of cell characteristics could be the key to uncovering new treatment options, as well as the reason why some people are diabetic and others are not.”
Diabetes mellitus affects more than 29 million people in the United States. There are two main types of diabetes mellitus, type I and type II. Type I diabetes mellitus is caused by insufficient production of insulin. Type II diabetes mellitus is caused by insulin resistance or the inability of the body to properly respond to the insulin produced by the body. Type I diabetes mellitus results from dysfunction or loss of insulin producing beta cells in the endocrine portion of the pancreas. Insulin is a hormone that helps the body keep normal blood sugar levels, and incorporate sugar in the bloodstream into cells to grow and repair tissues. Previously, only a single variety of beta cell was known to exist. However, using human pancreatic islets, or clusters of up to 4,000 cells, Grompe and colleagues identified a method to identify and isolate four distinct types of beta cells. They also found that hundreds of genes were differently expressed between cell subtypes and that these distinct beta cell subtypes produced different amounts of insulin.
All type 2 diabetics had abnormal percentages of the subtypes, suggesting a possible role in the disease process. Additional research is needed to determine how different forms of diabetes – and other diseases – affect the new cell subtypes, as well as how researchers may take advantage of these differences for medical treatment.