Non-alcoholic fatty liver disease (NAFLD) affects approximately 30% of the population, with that number increasing to 75% in obese individuals. Shockingly, the number of cases is expected to increase 21% by the year 2030 in the United States alone.
NAFLD refers to a broad range of liver conditions, which are all characterized by abnormally high levels of fat deposits in the livers of people who do not drink excessive amounts of alcohol. While not always fatal, NAFLD can lead to liver cirrhosis, or extensive scaring of the liver tissue. Cirrhosis, in turn, can cause life-threatening conditions such as liver cancer or liver failure. Whether or not N
AFLD will lead to extensive liver damage is not well understood and the primary therapeutic option is weight loss with no FDA-approved drug options. The projected increase in NALD cases combined with the poor treatment options makes this disease a significant public health burden.
Studying NALD can be quite complicated because the liver is complex organ made up of multiple different cell types. Investigators at the University of Edinburgh have simplified some of this complexity by figuring out a way to generate liver cells in a dish.
In studies published in the Philosophical Transactions of the Royal Society B, these scientists used human embryonic stem cells to generate hepatocyte-like cells (HLCs), or cells that are highly similar to liver cells isolated from humans. When exposed to fatty acids, they saw that the HLCs exhibited hallmarks of NAFLD, such as fat accumulation in liver cells, and changes in gene expression that are indicative of NAFLD.
In a press release, Dr. David Hay, one of the two senior investigators of this study, states:
“Our ability to generate human hepatocytes from stem cells, using semi-automated procedures, allows us to study the mechanisms of human liver disease in a dish and at scale.”
This approach is particularly valuable because it would replace the need to use cancer cell lines for this type of work. While valuable for many reasons, research done in cancer cells lines can be difficult to draw therapeutic conclusions from, because cell lines have significant genetic alternations from normal cells. Generating liver cells from human stem cells provides an important tool for high throughput screening of medically relevant therapies for NALD.