The pancreas contains clusters of cells called islets. Insulin is produced by one of these cell types – the β-cell (or beta cell). As discussed in many other blogs, insulin is the only hormone that lowers blood glucose levels.
In people with type 1 diabetes (T1D), the body’s immune system mistakenly attacks and destroys these β-cells. Over time, this leads to a loss of insulin production. Once enough β-cells are destroyed, the body can no longer properly control blood glucose levels, and insulin therapy becomes necessary.
It has long been thought that all of the β-cells are destroyed in individuals with T1D. However, this is not the case. In fact, 35–80% of people with T1D have some functioning β-cells. This is based on two lines of evidence. First, there is evidence of a protein in their blood called C-peptide. Because C-peptide is secreted at the same time that insulin is secreted and is commonly used as a biomarker of β-cell function. Second, pancreatic tissue from autopsies of some people with T1D actually do contain some β-cells, even many years after the diagnosis of T1D.
This raises the question: how do some β-cells survive? β-cells are very heterogeneous. Some of them can make themselves partially invisible to the immune system, so are unlikely to be attacked. Others can change their appearance or even function in response to being attacked.
So, what does this mean clinically? Even low levels of C-peptide are linked with better glucose control, fewer hypoglycemic episodes and a lower risk of diabetes-related complications. Because of this, some researchers are working on ways to preserve as many β-cells as possible.
About the author
Camille Préfontaine
Camille is a graduate student in Physiology at the University of Manitoba researching beta cell stress in type 1 diabetes. Camille studies a potential pathway which may cause beta cells to become stressed in type 1 diabetes. Camille is working to better understand the role beta cell stress is type 1 diabetes progression, potentially leading to new treatment strategies.
