Researchers at Boston’s Dana-Farber Cancer Institute managed to reverse brain disease and restore fertility and the sense of smell in prematurely aged mice, using a gene therapy technique.
The aging process shortens coatings on the ends of chromosomes, called telomeres, causing cells to stop dividing, stem cells to hibernate, brain cells to die and organs to atrophy. By restoring the telomeres in the mice, scientists were able to halt these processes, according to a study published in the journal Nature.
“These mice were equivalent to 80-year-old humans and were about to pass away,” Dr. Ronald DePinho, co-author of the paper and a scientist at Dana-Farber, told the Wall Street Journal. After the experiment, “they were the physiological equivalent of young adults.”
The mice, which the researchers genetically engineered to age prematurely, had atrophied spleens, damaged intestines and impaired senses of smell. Their brains were shrunken and incapable of growing new cells and the male mice had shrunken testes and low sperm counts.
“We stacked the deck against us and asked, ‘Is there a point of no return?'” DePinho told the Journal.
A month after scientists gave the mice an estrogen-based compound to reactivate the dormant telomerase gene, their brains were producing new cells and their spleens, testes and brains all grew. Key organs showed improved function, as did the sense of smell. The mice went on to live a normal lifespan.
The study is only a first step toward a similar treatment for humans. One risk is cancer; tumors have been shown to reactivate the telomerase gene, allowing their cells to reproduce themselves. DePinho told the newspaper that the next step is to try the technique on normally aged mice to determine whether similar results can be achieved.
