An uncontrolled protein synthesis might be one of the reasons behind premature aging disorder Hutchinson-Gilford progeria.
It may seem paradoxical, but studying what goes wrong in rare diseases can provide useful insights into normal health. Researchers probing the premature aging disorder Hutchinson-Gilford progeria have uncovered an errant protein process in thedisease that could help healthy people as well as progeria sufferers live longer. "The production of proteins is an extremely energy-intensive process for cells ," says Martin Hetzer, vice president and chief science officer of the Salk Institute and senior author of the paper.
‘Reducing protein synthesis can extend lifespan--and thus may offer a useful therapeutic target to counter both premature and normal aging.’
"When a cell devotes valuable resources to producing protein, other important functions may be neglected. Our work suggests that one driver of both abnormal and normal aging could be accelerated protein turnover." Hutchinson-Gilford progeria is a very rare genetic disease causing people to age 8 to 10 times faster than the rest of us and leading to an early death. The rare mutation occurs in one of the structural proteins in the cell nucleus, lamin A, but it has been unclear how a single defective protein in the nucleus causes the myriad rapid-aging features seen in the disease.
Initially, Salk Staff Scientist Abigail Buchwalter, first author of the paper, was interested in whether the mutation was making the lamin A protein less stable and shorter lived. After measuring protein turnover in cultured cells from skin biopsies of both progeria sufferers and healthy people, she found that it wasn't just lamin A that was affected in the disease.
"We analyzed all the proteins of the nucleus and instead of seeing rapid turnover in just mutant lamin A and maybe a few proteins associated with it, we saw a really broad shift in overall protein stability in the progeria cells," says Buchwalter. "This indicated a change in protein metabolism that we hadn't expected."
Along with the rapid turnover of proteins, the team found that the nucleolus, which makes protein-assembling structures called ribosomes, was enlarged in the prematurely aging cells compared to healthy cells.
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The work supports other research that appears in the same issue showing that decreasing protein synthesis extends lifespan in roundworms and mice. The Hetzer lab plans to continue studying how nucleolus size may serve as a reliable biomarker for aging.
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Source-Eurekalert