Bone morphogenetic protein 8B (BMP8B) plays a key role in regulating thermogenesis in brown adipose tissue, according to the findings of a research work published in Cell, the journal with the most impact on the field of biomedicine and molecular biology. The research group of Molecular Biology and Gene Regulation of the Adipose Tissue and its Diseases, led by Francesc Villarroya, professor at the Department of Biochemistry and Molecular Biology and director of the Institute of Biomedicine of the University of Barcelona (IBUB), affiliated centre to the campus of international excellence Barcelona Knowledge Campus (BKC) has taken part in the research.
The new research work, which presents a new mechanism to regulate brown adipose tissue, is also signed by experts from the Research Group of de NeurObesity (University of Santiago de Compostela), led by lecturer Miguel López, in collaboration with research teams from research centres in Iowa (United States), Stockholm (Sweden) and Cambridge (United Kingdom).
Brown adipose tissue: the mechanism for thermogenesis
One of the basic causes related to the epidemic of obesity is the malfunctioning of the brown adipose tissue. Unlike white adipose tissue, which is the most common type of fat, brown adipose tissue does not store up lipids. Instead, it oxidizes them in order to obtain energy which is released as heat. This phenomenon is known as thermogenesis. Hence, brown adipose tissue helps to "burn more calories" and to produce body heat from fat. For this reason, this special type of fat has attracted the attention of the research group as a potential therapeutic target to treat obesity. However, molecular mechanisms that regulate its functioning are not well known and further research is still needed.
Bone morphogenetic proteins are members of the transforming growth factor TGF-β family. Traditionally, they have been related to the formation of bone, cartilage and connective tissue. The results from the new study show that, for the first time, BMP8B is expressed in high levels in brown adipose tissue and in the hypothalamus, modulating key aspects of the thermogenesis.
As experts mention, knockout mice of BMP8B (that is, without the gene BMP8B) used for research, are markedly obese, despite having a reduced food intake, due to a lower capacity to burn fat in brown adipose tissue. The effects of BMP8B on brown adipose tissue are regulated by the hypothalamus, a very important brain area for the regulation of energy. The administration of minimum doses of BMP8B in the hypothalamus is sufficient to increase in a powerful way body temperature of animals, as a result of stimulating the production of heat by brown adipose tissue.