Nearly 2 billion people worldwide are living with Fatty Liver Disease, which occurs when lipid droplets – the sites where fat is stored in cells – accumulate in the organ.
The condition increases the risk of cancer, heart disease and type II diabetes among other health issues.
Scientists have long hypothesized about the different mechanisms our bodies use to breakdown lipid droplets including known lipid degrading enzymes and lipophagy, a process where cells breakdown fat for use as energy. New evidence published in the journal Cell Reports suggests we break down fat differently than previously thought.
“The relationship between enzymes and fat-busting processes like lipophagy haven’t been explored in-depth, so we only partially understand how lipid droplets are turned into energy,” said Douglas Mashek, PhD, researcher within the University of Minnesota Medical School and College of Biological Sciences who led the study. “The findings really challenge what is currently accepted in the field.”
Currently, scientists believe an enzyme called ATGL breaks down fats in most cells, creating fatty acids which are shuttled to the mitochondria and burned for energy.
However, Mashek, post-doctoral researcher Aishwarya Sathyanarayan, and colleagues discovered ATGL is not responsible for most of the fat broken down in the liver. Instead it appears to promote a signal that ultimately spurs lipophagy, reducing most of the lipid droplets held in the liver.
By better understanding the networks and processes involved in breaking down fats, Mashek says, we can move closer to pharmaceutical, dietary or lifestyle interventions to prevent or treat fatty liver disease, which currently has no FDA-approved therapies.