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Researchers have discovered what appears to be the first
animal evidence linking aging and age-related diseases such
as cancer, Alzheimer’s and Huntington’s.
They found a class of molecules in the roundworm C. elegans
and in humans that can prolong the life of the worm and prevent
the accumulation of abnormal proteins that cause a serious
disease similar to Huntington’s.
The molecules are known as small heat shock proteins. They
prevent the accumulation of abnormal proteins by binding to
cellular proteins that are damaged or unfolded, a practice
that may be able to stave off both aging and age-related disease.
Many diseases, including Alzheimer’s, Huntington’s,
Parkinson’s and prion diseases, are thought to be caused
by protein clumping or aggregation--and the list is growing.
The current finding suggests that heat shock proteins may
influence many age-related illnesses, and the pharmaceutical
industry is already looking for ways to increase the activity
of heat shock proteins. If the drugs work, they may be able
to protect protein function and even extend life.
In a past study, researchers found that modifying the daf-2
gene in C. elegans doubled the worms’ lifespan. The same
pathway has also been found to affect lifespan in fruit flies
and mice and is likely to control human lifespan as well.
Another study found that the long-lived, altered daf-2 worms
accumulated disabling proteins later in life, which means
that they not only live longer but also have a delayed onset
of age-related disease.
In the current study, researchers found that the expression
of genes for four small heat shock proteins "sharply
increased" in the long-lived daf-2 mutant worms, and
that two key proteins, DAF-16 and HSF-1, were required for
the boost.
Researchers used a technique called scientists RNA interference,
or RNAi, to show that the heat shock proteins account for
a substantial part of the worms' increased lifespan.
They also found that decreased heat-shock protein gene expression
accelerated the onset of Huntington's-like "polyglutamine"
protein aggregation.
Researchers concluded that regulating the small heat shock
proteins could influence both aging and age-related diseases.
Science
Blog May 2003
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