A group of scientists from the Ecole Polytechnique Federale de Lausanne (EPFL) in Switzerland, along with researchers from the Netherlands and Italy, have unearthed key information that could help combat two of the major effects of diabetes. They learned that bile acids could help fight both inflammation and resistance to insulin, which are two of the most common symptoms of type II diabetes. One of the teams, led by EPFL scientist Kristina Schoonjans, discovered that bile acids can regulate the activity of a key receptor, which can in turn control inflammation. Reducing levels of inflammation help counter the effects of insulin resistance. The results of this discovery could lead to the development of new and effective forms of treatment for diabetes patients.
What is diabetes mellitus?
Diabetes mellitus is a metabolic disease that develops due to increased sugar levels in the bloodstream. The common effects of diabetes include greater appetite and thirst, recurrent urination, and in the worst cases, heart disease and stroke. These symptoms form due to insulin resistance, which is the inability of the body to process the blood sugar-regulating hormone insulin properly. The two major types of diabetes are type I and type II DM. Type II diabetes mellitus is the most common type of the disease, accounting for as much as 90% of cases, and is believed to be closely linked to obesity. Chronic inflammation and the subsequent insulin resistance are two of the leading issues behind type II diabetes.
The action of macrophages
The inflammation symptoms are caused by the bodies known as macrophages that nest themselves within the fat tissue. Macrophages are white blood cells that consume foreign substances in the body and work to activate the immune system. M1 macrophages are known for secreting substances that promote inflammation. The macrophages within the tissue signal others to gather around the fat cells. Aside of the inflammatory effects, the grouping of macrophages in the tissue interferes within the capacity of the fat cells to take in and appropriately respond to insulin, resulting in insulin resistance. Many kinds of diabetes treatments are targeted toward preventing macrophages from accumulating among fat tissue and causing insulin resistance.
Inhibitory effect of bile acids
The goal of the EPFL scientists was to find a way to inhibit the inflammation caused by macrophages. The Schoonjans’s team discovered a receptor found on macrophages that prevents the inflammation from the type II diabetes. The receptor, known as TGR5, is responsible for sending out the chemical signal that alerts macrophages to fat tissue. The scientists learned that instead of being confined to the liver and intestines, certain chemicals found in bile, or bile acids, are able to pass into the bloodstream and act in the same way as many hormones do. The acids were able to hook on to and activate the TGR5 receptors, causing a rapid decrease in macrophage accumulation and a significant decrease in inflammatory symptoms.
Implications for future diabetes treatment
These results may pave the way for new methods of both diabetes and obesity treatments. The study was able to discover an effective way for diminishing inflammation. This presents very promising news for many type II diabetes patients. Bile acids cannot be directly used for diabetes treatment, but several substances or compounds can be synthesized to replicate the acid action from the TGR5 receptor. The information discovered by the EPFL team could form the basis for the development of a variety of treatments. This may also be extended to cover general inflammation symptoms, as well as a variety of related disorders, including autoimmune diseases, asthma, allergies, sarcoidosis, and even cancer.