It may be that this particular mechanism is the proximate cause of
death in these yeast cells. But this is obviously a special case of
a more general "accumulation of garbage" problem. Cells are designed
to keep themselves clean; they have metabolism to deal with various
undesirable products and digest or excrete them. But these mechanisms
are not perfect; the possible variety of things which can go wrong is
almost infinite, and inevitably some waste products accumulate.
It may be that specific treatments can be found for certain wastes, like
the amyloid plaques in Alzheimer's disease or these DNA rings in stem
cells. But my guess is that this won't lead to a breakthrough in life
extension (although it may help with certain diseases). Fix the DNA rings
and some other chemical buildup will kill the cells a little while later.
Not to say that this information is useless; curing some diseases and
possibly even a moderate 5-10% increase in maximum lifespan would be
a wonderul advance. But it is not likely to solve the aging problem.
Hal