Harnessing brown fat could offer novel approach to combat obesity

Could obesity be treated without reducing food intake? A new study co-led by Dr. Antonio Zorzano and Dr. Manuela Sánchez-Feutrie at the Institute for Research in Biomedicine (IRB Barcelona) indicates this might be possible, at least in animal models.

Published in Nature Communications, the research identifies a key role for neuritin 1, a protein previously linked to the nervous system, which is also produced in brown adipose tissue. In this tissue, it acts as a powerful driver of energy expenditure and metabolic health.

Unlike current anti-obesity and antidiabetic drugs like Ozempic or tirzepatide, which work by suppressing appetite, neuritin 1 boosts energy burning without affecting food intake. "By elevating neuritin 1 levels specifically in brown fat, we observed that the animals burned more energy, preventing fat accumulation," explains Dr. Zorzano, who is also a professor at the University of Barcelona and a researcher at CIBERDEM.

This metabolic boost led to significant health improvements, including reduced weight gain, improved insulin sensitivity, and lower liver inflammation, even in animals fed high-calorie diets.

Previously known for its role in neuronal plasticity, neuritin 1 is now shown to have a metabolic function in brown fat—a type of fat specialized in generating heat through thermogenesis. This process burns energy to maintain body temperature, especially in response to cold. In this context, neuritin 1 stimulates mitochondrial activity and promotes the expression of thermogenic genes.

To induce its expression, researchers used a viral vector that drives neuritin 1 overexpression exclusively in thermogenic fat cells. The result was a sustained increase in metabolic activity without affecting food consumption or physical activity in the animals.

"These findings suggest that neuritin 1 could be a promising therapeutic candidate for treating obesity and associated conditions like type 2 diabetes and fatty liver disease through a new mechanism," highlights Dr. Sánchez-Feutrie.

Beyond animal model results, genetic data in humans also show a correlation between neuritin 1 and susceptibility to obesity, reinforcing the discovery's relevance. The team is exploring ways to develop this research into a future therapeutic strategy.

This research is still in its early stages. While promising, additional studies are needed before considering potential human applications.