Genetic Manipulation Leads to Increased Energy, Fat Loss and Metabolism
It’s simply amazing what scientists are capable of doing now with genetic switches. For quite a while all we could hope to do is turn on and off receptors, or keyholes that would unlock certain effects. But taking it one layer deeper,scientists are figuring out ways of actually switching on our own genetic abilities to affect the whole body. In this instance, scientists manipulated a virus that no longer harms the patient (a mouse in this case so the results may be skewed toward their particular metabolism) but instead activates what is known as the opiomelanocortin system. This system involves, as the name implies, our Opiod system (feel good chemicals) and our melanin system (what makes us tan – even though that’s obviously just one of the roles the melanin system plays) and once switched on, scientists noticed an increased desire to exercise, an increase in the release of fat, AND even more importantly, an increase in metabolism so that the extra fat released actually gets burned up.
I think in today’s world it’s far more important to consider the role of our diet on our level of adiposity (how fat we are) but for those interested in the deeper workings of the genetic system, this kind of study proves to be fascinating!
Eur J Neurosci. 2011 Mar 2. doi: 10.1111/j.1460-9568.2011.07633.x. [Epub ahead of print]
Simultaneous POMC gene transfer to hypothalamus and brainstem increases physical activity, lipolysis and reduces adult-onset obesity.
Research Service, Malcom Randall Veterans Affairs Medical Center, Gainesville, FL 32608, USA Department of Pharmacology and Therapeutics, University of Florida, College of Medicine, Gainesville, FL, USA Department of Aging and Geriatric Research, University of Florida, College of Medicine, Gainesville, FL, USA Geriatric Research, Education and Clinical Center, Malcom Randall Veterans Affairs Medical Center, Gainesville, FL, USA.
Pro-opiomelanocortin (POMC) neurons are identified in two brain sites, the arcuate nucleus of the hypothalamus and nucleus of the solitary tract (NTS) in brainstem. Earlier pharmacological and POMC gene transfer studies demonstrate that melanocortin activation in either site alone improves insulin sensitivity and reduces obesity. The present study, for the first time, investigated the long-term efficacy of POMC gene transfer concurrently into both sites in the regulation of energy metabolism in aged F344xBN rats bearing adult-onset obesity. Pair feeding was included to reveal food-independent POMC impact on energy expenditure. We introduced adeno-associated virus encoding either POMC or green fluorescence protein to the two brain areas in 22-month-old rats, then recorded food intake and body weight, assessed oxygen consumption, serum leptin, insulin and glucose, tested voluntary wheel running, analysed POMC expression, and examined fat metabolism in brown and white adipose tissues. POMC mRNA was significantly increased in both the hypothalamus and NTS region at termination. Relative to pair feeding, POMC caused sustained weight reduction and additional fat loss, lowered fasting insulin and glucose, and augmented white fat hormone-sensitive lipase activity and brown fat uncoupling protein 1 level. By wheel running assessment, the POMC animals ran twice the distance as the Control or pair-fed rats. Thus, the dual-site POMC treatment ameliorated adult-onset obesity effectively, involving a moderate hypophagia lasting ∼60 days, enhanced lipolysis and thermogenesis, and increased physical activity in the form of voluntary wheel running. The latter finding provides a clue for countering age-related decline in physical activity.
© 2011 The Authors. European Journal of Neuroscience © 2011 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.
PMID: 21366729 [PubMed - as supplied by publisher]