Subjects: R and D
Scientists know that resveratrol, a compound found in red wine improves health and longevity in laboratory mice. Now they’re beginning to figure out how.
David Sinclair and colleagues at Harvard have concluded that resveratrol activates sirtuin, a protein normally involved in gene expression and chromosomal repair.
Sinclair’s group had previously developed compounds that mimic the effects of resveratrol. One such compound was recently found to help mice stay thin despite consuming a high calorie, high fat diet, presumably by regulating gene expression.
Using these same compounds, Sinclair’s group has now demonstrated that sirtuin improves longevity in certain mouse cell cultures by suppressing transcription of proteins associated with aging. The group speculated in Cell last week that sirtuin may govern similar processes in intact mice (not just their cell cultures) and perhaps humans.
This research helps flesh out an exciting story about sirtuin. It looks like the protein performs 2 major functions. First, it assures that cells can access only the few genes they actually need to carry out their duties. This involves preventing access to 20,000 other genes that are in the DNA of every cell.
Sirtuin governs access to genes by wrapping around non-essential DNA, creating a protective shield.
Second, sirtuin repairs DNA when it breaks or gets damaged, as happens during normal aging or following radiation exposure, say from sunlight.
The problem is that when sirtuin gets involved in DNA repair, it loses effectiveness as a gene access manager. This leads to abnormal gene expression which somehow contributes to cell aging and cell death.
In a nutshell, we know that cell differentiation, aging and death are mediated by a common biochemical pathway in which sirtuin is a player, and we have compounds that activate sirtuin. This could get interesting.