New Enzyme Research May Stop Fatty Liver Disease Progression

An estimated 100 million people in the United States suffer from metabolic dysfunction-associated steatotic liver disease (MASLD), formerly called nonalcoholic fatty liver disease, according to the American Liver Foundation. While this common condition affects a vast portion of the population, roughly 20% to 25% of those diagnosed eventually develop metabolic dysfunction-associated steatohepatitis (MASH). This more severe form of fatty liver disease features excess liver fat accompanied by cellular injury, inflammation, and scarring.

New Enzyme Research Offers Hope for Fatty Liver Disease Progression

Current medical care largely relies on lifestyle modifications and efforts to limit further injury. Although some medications have recently become available, they are typically restricted to patients with advanced disease and carry common side effects, leaving treatment options scarce and no known cure for MASH. Now, recent preclinical findings are shedding light on potential new avenues for therapeutic intervention.

The Protective Role of UBE2N in Liver Health

Researchers co-led by Cedars-Sinai Health Sciences University and the University of Pittsburgh have identified an enzyme that may help safeguard the liver against severe damage. Published in Nature Metabolism, the multicenter study centers on an E2 ubiquitin-conjugating enzyme known as UBE2N.

Researchers advance promising therapy for fatty liver disease — Photo: Waco Tribune-Herald

Investigators discovered that levels of UBE2N decline inside liver cells as fatty liver disease advances. According to Ekihiro Seki, MD, PhD, professor of Medicine and Biomedical Sciences at Cedars-Sinai and co-corresponding author of the research, the enzyme naturally protects the organ from inflammation and injury by facilitating the removal of damaged mitochondria and aiding fat breakdown. When enzyme levels dropped, researchers observed an increase in damaged cells and overall liver injury.

UBE2N Tags Faulty Mitochondria to Suppress MASH

Scientists describe UBE2N as a dual-function molecular switch that connects mitochondrial quality control with MASH suppression. Mitochondria serve as the structures that generate energy for cells, but when they sustain damage and fail to clear, they generate excess reactive oxygen species and spark inflammatory cascades that harm hepatocytes.

By coordinating necessary ubiquitin signaling, UBE2N tags faulty mitochondria for degradation—a process called mitophagy—clearing them out before they can amplify injury. When researchers restored UBE2N to normal levels in the livers of laboratory mice, they noted clear reductions in fat accumulation, inflammation, and scarring.

UBE2N Enzyme Activates Mitophagy and Blocks Fatty Liver Disease Progression — Photo: longevitytoday.com

GPPD Inhibitor Reduces Liver Injury and Fibrosis

In related efforts, researchers at the Texas A&M College of Veterinary Medicine and Biomedical Sciences (VMBS) have been investigating another therapeutic target, MAP4K4, alongside collaborators at the University of Oklahoma. Their team tested an experimental small-molecule inhibitor named GPPD in preclinical models. Unlike treatments that focus solely on reducing fat, GPPD simultaneously improved fat accumulation, inflammation, liver injury, and fibrosis by decreasing the target protein’s activity without altering its overall levels.

Experts emphasize that translating these experimental strategies into human applications will require extensive further study. While the identification of UBE2N and alternative pathways offers promising targets for preventing advanced liver disease, clinical applicability remains entirely preclinical at this stage. Future investigations will need to determine how enhancing these protective mechanisms can complement existing therapies and safely translate to patients.