Brown fat tissue - a potential target to combat obesity

Abstract

From the global population perspective, the epidemic of "globesity" (more than one billion adults being overweight) represents one of the largest public health problems (1). Traditional reasoning related to the dysbalance between caloric intake and energy expenditure does not provide a satisfying explanation for a complexfailure to combat obesity. The brown adipose tisue (BAT) has a unique chemical structure and a specific metabolic role. A potential preventive co-factor is thermogenesis. BAT has the ability to dissipate energy byproducing heat, rather than storing energy as triglycerides. The cells of the white adipose tissue (WAT) contain one large globule of triglycerides which displaces the cell nucleus and other cell organelles excentrically, to the cell periphery. BAT contains numerous smaller droplets of triglycerides, much higher number of mitochondria and a specific uncoupling protein 1 or thermogenin. This specialized protein uncouples ATP production from mitochondrial respiration and converts energy into heat. Using sophisticated diagnostic techniques (e.g. imaging combination of positron-emisson tomography and computed tomography), scientists confirmed the importance of BAT not only in the newborn but also in adults who were found to possess considerable body stores of BAT.The highest proportion of BAT has been detected in lean individuals. As the body mass increases, BAT proportionately drops. Data both from animal and human studies suggest that BAT and mitochondrial uncoupling can be targeted for interventions to prevent and treat obesity. Melatonin and arginine have been proposed as possible interventional tools. The scientific world eagerly awaits further advanced studies to document possible metabolic and pharmacologic interventions, using BAT as a primary target to prevent and manage obesity (Fig. 5, Ref. 41).