The FGF21, a hormone that reduces the levels of glucose, is also an activator of brown adipose tissue metabolism, according to research that is cover of the latest issue of the journal Cell Metabolism, And Francesc Villarroya directing the Department of Biochemistry and Molecular Biology, University of Barcelona (UB) and CIBER Physiopathology of Obesity and Nutrition.
The study, published in the journal Cell MetabolismHas been done on mice neonates and could open new therapeutic targets to combat obesity by fibroblast growth factor 21 (FGF21), which releases the liver in response to dietary lipids.
In the article, the team describes how a new scoop on the action of FGF21 brown adipose tissue, the manager of energy expenditure and body heat generation.
“The FGF21 is an antidiabetic and antiobesity agent described in scientific literature since 2005,” says Villarroya. “Our work shows for the first time that the FGF21 causes thermogenesis in brown adipose tissue, ie, loss of calories to liberate heat. This process acts as a large energy sink.
Any agent that promotes and activates the metabolism of brown adipose tissue is by definition an anti-obesity agent, “explains Villarroya, an expert in the study of metabolic regulation models with genetically modified mice.
Discover this direct link between FGF21 and brown adipose tissue is a major scientific contributions of the work. “In studies in vivo “says Villarroya, we found that the active factor thermogenesis in brown adipose tissue. According to the standard model, however, this process is regulated by a brain adrenergic pathway. However, further studies in vitro found that the target of FGF21 was not the brain but the brown adipose tissue. If FGF21 acts directly on the brown adipose tissue and is independent of adrenergic control, opens up new avenues to explore mechanisms to control body fat.
Studies with animal models of preterm
The paper studies the biological activity of FGF21 with a new biological model: the neonatal animals. “Working with animal models of infants is another key job,” said the expert Catalan. “We know that the metabolic disturbances in fetal and neonatal stage have an impact on adult metabolism. In the case of mice during the fetal stage feed on glucose via the placenta. After birth, mice fed with milk maternal, very high in fat, for the first time must begin to metabolize them. The neonatal mouse is therefore an excellent animal model for studying patterns of metabolic adaptation to new requirements.
Recent studies using techniques of positron emission tomography (PET) confirm the high metabolic activity of brown adipose tissue in adults, an issue much discussed by the scientific community so far. Currently, UB experts working on new experimental protocols to better understand the relationship of FGF21 and lipid metabolism and the possible use of pharmacological or nutritional strategies for the management of overweight.
“We know that the liver produces this factor in response to dietary fatty acids. But not all fatty acids produced the same response: they are signals of varying intensity and the response of the liver varies. Could these signals modulate dietary strategies? In short, this means adapting diets so that they can induce better production of FGF21 and thus speed up the metabolism “.
At the level of human studies, one of the greatest scientific challenges of the future will be to study how this system works in diabetic patients and obese patients. “Interestingly, it appears that obese patients have more of FGF21, and this indicates that there is a problem of resistance factors. We’ll have to investigate this aspect as well.”
Francesc Villarroya directs the UB research group Genetics and Molecular Biology of mitochondrial proteins. Associated pathologies and is a member of the CIBER Physiopathology of Obesity and Nutrition (CIBERobn), established in 2006 under the coordination of the Instituto de Salud Carlos III and directed by Philip F. Casanueva.
Elayne Hondares, Meritxell Rosell, Frank J. Gonzales, Marta Giralt, Roser Iglesias, Francesc Villarroya. FGF21 Is Induced Hepatic Expression via PPAR at Birth in Response to Milk Intake and Contributes to Activation of Neonatal Brown Thermogenic Fat. Cell Metabolism.
Source: Universitat de Barcelona
|Category: Medical Science||Tags: adipose tissue, antidiabetic, antiobesity agent, FGF21, molecular biology, thermogenesis|