Alarming New Switch Found in Fatty Liver Disease Diabetes Research
Duke University researchers have identified a key regulatory switch in liver metabolism that could become a powerful new treatment target for both fatty liver disease diabetes progression and prediabetes. The finding, led by Phillip White, assistant professor of medicine at the Duke Molecular Physiology Institute, centers on branched chain amino acids, or BCAA, and how their breakdown in the liver is controlled by two opposing molecules. According to the Mayo Clinic, nonalcoholic fatty liver disease affects a significant portion of the global population and is closely linked to obesity, insulin resistance, and type 2 diabetes.
What Are Branched Chain Amino Acids and Why Do They Matter
BCAA are breakdown products of protein metabolism that have been associated with obesity and insulin resistance since a 1969 study in the New England Journal of Medicine. In 2009, Duke researchers led by Christopher Newgard identified BCAA as a robust marker of obesity and insulin resistance in humans. The landmark Framingham Heart Study later confirmed that BCAA levels are highly predictive of future diabetes development.
In the context of fatty liver disease diabetes research, what makes BCAA significant is not just their role as a passive marker. Growing evidence suggests they may actively contribute to driving metabolic disease. As Robert Gerszten, MD, director of clinical and translational research at Massachusetts General Hospital Heart Center noted, BCAA may play a direct role in the disease process itself, not merely reflect it.
The Regulatory Switch Behind Fatty Liver Disease Diabetes
In a healthy liver, BCAA are broken down through a tightly regulated process. In the fatty liver disease diabetes context, the molecular components responsible for BCAA breakdown are turned off by a single regulatory switch controlled by two opposing molecules: a kinase that inhibits breakdown and a phosphatase that activates it. When the kinase dominates, BCAA accumulate, fat builds up in the liver, and glucose regulation deteriorates.
The Duke team demonstrated that inhibiting the kinase or activating the phosphatase produced nearly identical results. Within one week in a Zucker fatty rat model of prediabetes, activating BCAA breakdown reduced fat deposition in the liver and improved glucose regulation without any change in body weight.
How a High Fructose Diet Worsens the Balance
Working with Duke colleague Mark Herman, the researchers found that a high fructose diet, such as one involving frequent consumption of sugary beverages, disrupts the kinase and phosphatase balance as part of a broader program that promotes fat accumulation in the liver. Kinase activity increases, phosphatase activity decreases, and the result is more liver fat and worse metabolic health. This mechanism helps explain why dietary sugar intake is so strongly linked to fatty liver disease diabetes risk.
The Connection to Fat Production in the Liver
The Duke team also linked the BCAA regulatory switch to ATP-citrate lyase, an enzyme that plays a central role in fat production in the liver. This enzyme interacts with and is regulated by the same kinase and phosphatase that control BCAA metabolism, establishing a direct mechanistic connection between protein breakdown, fat synthesis, and fatty liver disease diabetes development.
What This Means for Treatment
While the study is limited by its use of a single animal model and a short observation period, the results are promising enough to motivate longer term studies. As White noted, there is real potential for this regulatory switch to become a new target for treating fatty liver disease. The collaboration with researchers at the University of Texas Southwestern Medical Center, who developed a drug that inhibits the kinase, has already produced a candidate compound for further investigation.
FOMAT conducts Phase I through Phase IV clinical research across a national network of investigator sites throughout the United States. To learn more about active metabolic and liver disease studies, visit our patient active studies page.