In a curious new study, researchers have extended youth and lifespan in the model organism C. elegans with application of an antidepressant.
Pushing the clock back
In 2007 a team of scientists found that administering the antidepressant Mianserin to C. elegans worms could extend lifespan by 30-40%, but how was it doing it?
After treating thousands of these organisms with water or Mianserin, they measured gene activity in each group, as they got older. There were some dramatic changes in both groups. As we age, in mammals too, there are a number of widespread gene expression changes that occur. Whether this is an innately driven process, or as a response to increasing damage we're not yet sure. This altered pattern of gene expression has been termed 'transcriptional drift'. The order of youth seems to become chaotic, dysregulated and scrambled as most organisms get older.
"The orchestration of gene expression no longer seemed coordinated as the organism aged and the results were confusing because genes related to the same function were going up and down at the same time"
Delaying the inevitable
C. elegans normally enters maturity after one day, and they survive for 2-3 weeks. If administered early enough, Mianserin appeared to suppress this transcriptional drift and delay its onset. The worms given Mianserin showed the same gene expression at 10 days old as the normal group did at 3 days old. While the age of onset was delayed, it was merely pushed back and the drift began to occur, simply shifted by 7-8 days.
What does Mianserin do?
The drug interferes with signals relating to serotonin regulation, which is why it's used as an antidepressant in humans. While it's not yet clear exactly how the drug is exerting this 'delaying' property on transcriptional drift, it's raised some interesting questions.
"We think it is exciting to see that extending lifespan by extending young adulthood can be done at all. Transcriptional drift can be used as a new metric for measuring age-associated changes that start in young adulthood"
This probably won't work in humans
Humans are much, much more complicated than C. elegans, with millions of years of evolution between is. Mianserin is therefore unlikely to have anyway near the same effect, if its effect is positive at all. The researchers specifically cautioned the public taking the results as a go ahead for antidepressant usage. What the study does suggest however, is that there are mechanisms that can delay and interfere with this age-related change in gene expression also common to mammals. If we could work out ways to do the same thing in humans, we may well see similar effects.
Read more at MedicalXpress