Human Tissues Measured By Biological Clock
Nobody understands the reasons why we age, we have grown to know that it's just part of life. Scientists have been trying to understand why for years, what they do know is human tissues, are a factor that plays into our aging and its age may be able to be reversed to keep us younger, according to a new study.
Steve Horvath, a professor of human genetics at the David Geffen School of Medicine at UCLA and of biostatistics at the UCLA Fielding School of Public Health has invented a biological clock to further test this research.
"My goal in inventing this clock is to help scientists improve their understanding of what speeds up and slows down the human aging process," Horvath said in a news release.
In order to make the clock Horvath used a process that chemically changes DNA called methylation. The information used for his study was burrowed from previous researchers who analyzed the same study using healthy and cancerous human tissue.
"Gleaning information from nearly 8,000 samples of 51 types of tissue and cells taken from throughout the body, Horvath charted how age affects DNA methylation levels from pre-birth through 101 years," according to a university release. "To create the clock, he zeroed in on 353 markers that change with age and are present throughout the body."
In observing a tissue's biological age to its chronological age, the clock's accuracy was tested.
"It's surprising that one could develop a clock that reliably keeps time across the human anatomy," said Horvath.
Horvath noticed that although the biological and chronological ages matched there was an important finding that shed light to why breast cancer occurs. He found that a woman's breast tissue ages more quickly than the rest of her body.
"Healthy breast tissue is about two to three years older than the rest of a woman's body," said Horvath. "If a woman has breast cancer, the healthy tissue next to the tumor is an average of 12 years older than the rest of her body."
Another valid finding was that the biological clock ticks faster from the day we are born until we reach adolescence. Once we reach the age of 20 it slows down to a constant rate.
It intrigued Horvath to discover how we could make ourselves younger and so he did more research on how the adult cells that we own could be reset to young cells.
He found that it could be made possible by turning the adult cells into pluripotent stem cells (young cells) which in turn rewinds the biological cell clock to zero.
"The big question is whether the biological clock controls a process that leads to aging," said Horvath. "If so, the clock will become an important biomarker for studying new therapeutic approaches to keeping us young."
The findings are published in the journal Genome Biology.