What are the study's implications for human aging?
"We all think about protecting the brain and the heart, but the intestine is a vital tissue type for healthy aging," Walker said. "If anything goes wrong with the mitochondria in cells, the consequences could be devastating, and if anything goes wrong with our intestines, that may have devastating consequences for other tissue types and organs. Not only is the intestine essential for the uptake of nutrients that are a vital source of energy, but it is also an important barrier that protects us from toxins and pathogens in the environment. The intestine has to be well-maintained.
"No one yet knows what causes aging at the cellular or tissue level," Walker said. "As we age, our mitochondria become less efficient and less active. That has far-reaching consequences, because if the mitochondria decline, then all of our cellular functions may be compromised. However, it's a dangerous road to travel to say, 'This is the cause of aging.'"
The PGC-1 gene activates the cells' mitochondria and regulates mitochondrial activity in mammals and flies. The gene is a potential target for pharmaceuticals to combat age-related diseases, Walker said.
The study raises the question of whether increasing mitochondrial activity is an effective strategy to delay aging. If so, increasing the PGC-1 gene may prove key, Walker said.
The first question Walker and his colleagues asked was whether the fruit fly version of PGC-1 has the same function as the mammalian version. They found it does.
The biologist increased levels of expression of the fly version of the PGC-1 gene and found that this made mitochondria more active. They then tested whether boosting PGC-1 activity would slow aging and, again, they found that it did, when they focused on the fly's digestive tract.
The fly's intestine is maintained by adult ste
|Contact: Stuart Wolpert|
University of California - Los Angeles