Mechanism to combat obesity without reducing food consumption identified
Mechanism to combat obesity without reducing food consumption identified
Europa Press
La Jornada Newspaper, Friday, September 5, 2025, p. 6
Madrid. A team of researchers co-led by the Barcelona Institute for Research in Biomedicine (IRB) has identified a possible mechanism for treating obesity in animals without reducing food intake, by activating brown fat.
The study, published in the journal Nature Communications , highlighted the “key role” of neuritin 1, a protein previously linked to the nervous system that is also produced in brown adipose tissue, where it acts as a “potent driver” of energy expenditure and metabolic health.
“By increasing neuritin 1 levels specifically in brown fat, we observed that the animals burned more energy, which helped prevent fat accumulation,” explained Antonio Zorzano, co-leader of the study, professor at the University of Barcelona and researcher at the Diabetes and Associated Metabolic Diseases Network Biomedical Research Center (Ciberdem).
Neuritin 1, unlike some current drugs for obesity and diabetes that act by suppressing appetite, increases energy burning thanks to its metabolic function in brown fat, which specializes in heat generation through a process known as thermogenesis.
This process involves burning energy to maintain body temperature, especially in response to cold, where neuritin 1 stimulates mitochondrial activity and promotes the expression of thermogenic genes.
To activate it, scientists used a viral vector that promotes the overextension of neuritin 1 exclusively in thermogenic fat cells, resulting in a sustained increase in metabolic activity without affecting the animals' food consumption or physical activity.
Significant improvements
This metabolic boost has also been demonstrated through “significant” improvements such as reduced weight gain, improved insulin sensitivity, and reduced liver inflammation, even in animals fed high-calorie diets.
"These findings point to neuritin 1 as a promising therapeutic candidate for treating obesity and its associated conditions, such as type 2 diabetes and fatty liver disease, through a mechanism that differs from current approaches," emphasized Manuela Sánchez-Feutrie, co-director of the research at IRB Barcelona.
Furthermore, human genetic data have shown a correlation between neuritin 1 and susceptibility to obesity, reinforcing the "potential relevance" of the discovery, which could lead to a future therapeutic strategy.
“Solid and reliable” conclusions
Professor Rubén Cereijo Téllez emphasized that the work has shown "solid and reliable" conclusions, after which he noted that recent human studies have shown that people with greater amounts of brown adipose tissue have a lower risk of developing type 2 diabetes or cardiovascular disease.
"This discovery, therefore, reveals for the first time an interesting new mechanism by which brown adipose tissue can be activated; it even demonstrates that treating brown adipose tissue cells with neuritin-1 alone is sufficient to activate their 'fat-burning' function in experimental models," Cereijo noted.
The specialist described as "particularly interesting" the possibility of communication between brown and white adipose tissue, a process in which "brown gives white the order" to mobilize its reserves to be burned and reduce both weight and lipid and blood sugar levels, which helps prevent or counteract obesity, type 2 diabetes, cardiovascular disease, or fatty liver disease.
"Activating it in adult humans would contribute not only to direct fat burning, but also to increasing communication between brown adipose tissue and other organs through the release of bathokines," pointing to the possibility of designing new therapeutic strategies aimed at improving the metabolic status and quality of life of people affected by the aforementioned pathologies.
Experimental models
Cereijo echoed the limitations expressed by the authors of the article, who acknowledged that this was a study conducted in experimental cell and animal models, and that adult humans have less brown adipose tissue relative to their size than mice, and that it becomes progressively inactive with age, especially in conditions of obesity or diabetes.
For this reason, he emphasized the need to test the regulation of this molecule and its blood levels in humans, both healthy and those with these clinical conditions, to verify that it is performing the same actions as in experimental models.
“Even if human neuritin-1 actually performed these actions, being a protein that must maintain its complex structure to perform its functions, it would be difficult to market it as such in injectable form, for example, so the strategy to follow would be to fully discover exactly how it acts in brown adipose tissue cells and design a drug that simulates its actions,” Cereijo concluded.
For his part, the director of the Joint University Institute of Sport and Health at the University of Granada, Jonatan R. Ruiz, agreed with the "confidence and solidity" of the study's results, which could serve as a starting point for future research in the field of obesity and metabolic diseases.
Promising results
"The study presents very promising results in research on how to activate brown adipose tissue in animal models, and its impact on the regulation of energy metabolism, glycemia, and liver inflammation," said Ruiz, who is also a professor of physical activity and health at the Faculty of Sports Sciences at the University of Granada.
However, like Cereijo and the study's authors, he emphasized the importance of keeping in mind that it is not yet known whether this protein will have the same effect in humans, and that translating these findings into clinical practice will require the development of strategies that activate this mechanism in humans and verify its benefits in controlling obesity.
The research was funded by several core facilities at IRB Barcelona, including Bioinformatics and Biostatistics, Functional Genomics, Protein Expression, and Histopathology. It also included the participation of collaborators from international institutions.
jornada
