Their reports will be published in the August 15th edition of Genes & Development.
Living longer, weighing less
Dr. Ying-Hue Lee and colleagues at Academia Sinica took a different approach towards the obesity epidemic, analyzing the effects of C/EBP gene replacement in mice. The C/EBP protein family consists of 5 members, 3 of which (alpha, beta, and delta) have established roles in promoting adipogenesis (fat cell differentiation). The researchers were specifically interested in determining the physiological impact of replacing the C/EBPalpha gene with the C/EBPbeta gene.
"No doubt, C/EBPalpha is very important for life as indicated by many excellent studies related to its physiological function. Still, we wondered that its cousin, C/EBPbeta, might do the job well as well if given a chance," explains Dr. Lee.
Dr. Lee and colleagues utilized an existing strain of mice that contains the alpha-to-beta gene substitution, referred to in the paper as "beta/beta mice." They found that beta/beta mice not only live an average of 5 months longer than wild-type mice, but are markably leaner, apparently burning fat at a much higher rate than normal mice.
Dr. Lee and colleagues observed that despite their svelte appearance, beta/beta mice actually eat more food and are no more active than their genetically normal littermates. In search of the cause of this revved-up metabolism, Dr. Lee's team found that the white adipose tissue, which is normally reserved for fat storage, had actually been converted into fat burning cells in beta/bet
Contact: Heather Cosel-Pieper
Cold Spring Harbor Laboratory