Diabetes Adjuvant
The recently discovered hormone fabkin is involved in the regulation of metabolism and may play an important role in the development of type 1 and type 2 diabetes, – these are the results of a study conducted by the Center for Metabolic Research at the Harvard T.H.Chan School of Public Health.
The study showed that the level of fabkin in the blood was abnormally high in mice and people with type 1 or type 2 diabetes. Blocking the activity of this hormone prevented the development of both forms of the disease in animals. According to the researchers, fabkin probably plays a similar role in humans, and the hormone may be a promising target for the treatment of diabetes.
For many decades, scientists have been looking for an intermediary substance that reports on the energy reserves of adipocytes in order to generate appropriate endocrine reactions, for example, the production of insulin by beta cells of the pancreas. A new study has identified the hormone fabkin, which controls this important function through an unusual molecular mechanism.
Insulin, leptin and many other hormones are involved in the regulation of metabolism. Fabkin differs from known hormones in that it is not a single molecule with one specific receptor, but consists of a complex of proteins, including fatty acid binding protein 4 (FABP4), adenosine kinase (ADK) and nucleoside diphosphate kinase (NDPK). In a series of experiments, the researchers determined that fabkin regulates energy signals outside of cells. These signals then control the function of target cells through a family of receptors. In the case of diabetes, fabkin controls the function of pancreatic beta cells, which are responsible for the production of insulin.
More than a decade ago, researchers discovered that FABP4 is released from fat cells during lipolysis, a process in which lipids stored in fat cells are broken down, more often in response to starvation. Since then, numerous studies have shown a correlation between circulating FABP4 and metabolic diseases, including obesity, diabetes, cardiovascular disease and cancer. However, the mechanism of action was unknown.
In this work, the authors showed that FABP4, getting from fat cells into the bloodstream, binds to NDPK and ADK enzymes and forms a protein complex that is identified as the fabkin hormone. In this protein complex, FABP4 modifies the activity of NDPK and ADK to regulate the level of ATP and ADP energy molecules. The researchers found that surface receptors on nearby cells detect a change in the ratio of ATP to ADP, forcing cells to respond to a change in energy status. Thus, fabkin is able to control the function of target cells.
The authors showed that the beta cells of the pancreas that produce insulin are affected by fabkin and that this hormone is the driving force behind the development of diabetes. Neutralization of fabkin in mice prevents the development of diabetes even with obesity, and already diabetic rodents recover.
Fabkin's discovery added to the fundamental understanding of how hormones regulate energy metabolism. In the long term, this may lead to the creation of a cure for diabetes.
Article by K.J.Prentice et al. A hormone complex of FABP4 and nucleoside kinases regulates islet function is published in the journal Nature.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru According to Harvard T.H. Chan School of Public Health: Newly identified hormone may be a critical driver of type 1 and type 2 diabetes.