Link Between Obesity, Diabetes and Liver May Lead to New Therapies
The links between obesity and type 2 diabetes are well-known, but why they are linked is still not well understood. One reason could be the effect that extra body weight has on liver function, a new study has found. An international team of scientists found that over-expression of a specific protein in the liver, caused by obesity, could be the key.
The protein, called tyrosine phosphatase receptor gamma (PTPR-y) acts as a molecular link between obesity-induced inflammation and insulin resistance. This is specifically associated with type 2 diabetes mellitus (T2DM).
The research team focused on PTPR-y and inflammation of the liver.
The researchers were led by Roberto Coppari, PhD, at the University of Geneva (UNIGE) Facility of Medicine Diabetes Centre and included colleagues from Switzerland, Japan, the United States, and France. Human data from those varied sources were also used to conduct the research.
The findings started with an initial analysis of the human data and how the PTPR-y expression was altered in obese individuals. They found that it does increase with obesity and its resulting liver inflammation, which they theorized could be inhibiting insulin receptors' action. The team then turned to mice.
The team reduced or increased expression of PTPR-y in mice. Slowing it did not prevent mice from becoming obese on a high-calorie diet, but it did lower or stop their insulin resistance. These same mice had a higher glucose tolerance. Their incidence of diabetes symptoms were thus far lower than in control subjects.
“In summary, our results indicate that the increased hepatic PTPR-? level observed in obesity is sufficient to cause insulin resistance and hence unveil PTPR-? as a new target for anti-T2DM therapy,” the authors wrote. “Our data suggest that means aimed at decreasing hepatic PTPR-? expression/activity should improve T2DM. This goal could be achieved by development of specific PTPR-? inhibitors.”
Source: GenengNews.com