In a wide range of mammals, caloric restriction has shown significant benefits in delaying or even preventing age-related diseases and aging. Yet, biologists have been struggling to provide a comprehensive explanation behind this magical formula. In a recent study conducted in Sweden, the one enzyme responsible for the health benefit of caloric restriction was revealed – details in Forum or Gizmag. However, an American research group has provided another insight into how calorie restriction works by altering the genes of fruit flies and thereby achieving a 50 percent increase in their lifespan.
Results conducted on fruit flies have been positive. However, whether these results are applicable to long lived species such as humans is still under scrutiny. Let’s first have a better understanding of the fruit flies. It is specie, which has a tremendously short lifespan; from being an egg to become an adult takes only 7 days. The short lifespan of fruit flies have made them a standard prototype of longevity research both for physiology and genetics studies.
A dedicated research team from The University of California, Los Angeles and Salk Institute for Biological studies altered the genes of the intestinal stem cells of the fruit fly (Drosophila Melanogaster). These cells are called dPGC-1, a cell structure present in human’s DNA under the name of PGC-1. The change induced the fruit flies’ intestine with slower aging, and therefore, they enjoyed a 50 percent longer lifespan.
For both mammals and flies, PGC-1 gene cells are responsible for the control of various mitochondria presents in animal’s cells. The mitochondria is considered as being the power plant, as it is where fats and sugar from food are turned into energy used for cellular performance. Earlier studies had shown that calorie-restriction provided animals with more mitochondria. So the scientists made a test to understand what would happen if PGC-1 were given an even higher excess of mitochondria.
Genetic engineering methods were used to make the Fruit flies’ PGC-1 gene alike to organisms that were under calorie restriction diets. In other words, the volume of mitochondria and energy in cells were increased. The effect after increasing the speed of the stem and progenitor cells of the fruit flies’ intestine was that the intestinal tissues experienced a better response mechanism and therefore, cells became healthier as well as the fruit flies lived longer.
In correlation to the level of genetic engineering induced to the fruit flies, their lifespan was extended by 20 to 50 percent in comparison to a normal fruit fly.
The scientists suggest that the PGC-1 can act as a potential biological tool to delay aging, and it would be possible to develop drug and therapies targeting this age-brake. According to, the team, the theory is that when dPGC-1 was boosted with mitochondria, the stem cell was stimulated to energize intestinal tissues and therefore, ensuring healthier intestines for the fruit flies.
According to Leanne Jones who is an associate professor at Salk’s laboratory of Genetics as well as the lead researcher of the project, delaying aging of crucial single organ such as for the current experiment the intestine can have significant benefits on overall longevity and health. For example, in case of disease, it might be essential to emphasis on having particular organs healthy and in this case, PGC-1 might be the pathway.
The complete research is available in November’s Cell Metabolism and at University of California, Los Angles and Salk Institute for Biological Studies.
Source: Gizmag, Salk Institute, Cell Metabolism and University of California.
Sun, Dec 25, 2011
Bioscience, Health And Aging, Stem cells