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[Press release] DNA clock helps predict lifespan

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http://biocomicals.blogspot.com/2011_05_01_archive.html

Biocomicals by Dr. Alper Uzun is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

From the 30 January 2015 University of Edinburg press release

Scientists have identified a biological clock that provides vital clues about how long a person is likely to live.

Researchers studied chemical changes to DNA that take place over a lifetime, and can help them predict an individual’s age. By comparing individuals’ actual ages with their predicted biological clock age, scientists saw a pattern emerging.

Biological age

People whose biological age was greater than their true age were more likely to die sooner than those whose biological and actual ages were the same.

Four independent studies tracked the lives of almost 5,000 older people for up to 14 years. Each person’s biological age was measured from a blood sample at the outset, and participants were followed up throughout the study.

Researchers found that the link between having a faster-running biological clock and early death held true even after accounting for other factors such as smoking, diabetes and cardiovascular disease.

The same results in four studies indicated a link between the biological clock and deaths from all causes. At present, it is not clear what lifestyle or genetic factors influence a person’s biological age. We have several follow-up projects planned to investigate this in detail.

Dr Riccardo Marioni

Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh

DNA modification

Scientists from the University of Edinburgh, in collaboration with researchers in Australia and the US, measured each person’s biological age by studying a chemical modification to DNA, known as methylation.

The modification does not alter the DNA sequence, but plays an important role in biological processes and can influence how genes are turned off and on. Methylation changes can affect many genes and occur throughout a person’s life.

This new research increases our understanding of longevity and healthy ageing. It is exciting as it has identified a novel indicator of ageing, which improves the prediction of lifespan over and above the contribution of factors such as smoking, diabetes, and cardiovascular disease.

Professor Ian Deary

Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh

International collaboration

The study is published in the journal Genome Biology and was conducted by researchers from the University of Edinburgh, University of Queensland, Harvard University, University of California, Los Angeles (UCLA), Boston University, the Johns Hopkins University Lieber Institute for Brain Development and the U.S. National Heart, Lung and Blood Institute.

This study was carried out at the University of Edinburgh’s Centre for Cognitive Ageing and Epidemiology (CCACE), which is supported by the Medical Research Council (MRC) and the Biotechnology and Biological Sciences Research Council (BBSRC) as part of the Lifelong Health and Wellbeing programme, a collaboration between the UK’s Research Councils and Health Departments which is led by the MRC.

 

February 2, 2015 Posted by | Medical and Health Research News | , , , , , , | Leave a comment

[Press Release} UCLA scientist uncovers biological clock able to measure age of most human tissues

From the 20 October press release via EurkAlert

Study finds women’s breast tissue ages faster than rest of body

 IMAGE: A newly discovered biological clock measures aging throughout the body.

Click here for more information. 

Everyone grows older, but scientists don’t really understand why. Now a UCLA study has uncovered a biological clock embedded in our genomes that may shed light on why our bodies age and how we can slow the process. Published in the Oct. 21 edition of Genome Biology, the findings could offer valuable insights into cancer and stem cell research.

While earlier clocks have been linked to saliva, hormones and telomeres, the new research is the first to identify an internal timepiece able to accurately gauge the age of diverse human organs, tissues and cell types. Unexpectedly, the clock also found that some parts of the anatomy, like a woman’s breast tissue, age faster than the rest of the body.

“To fight aging, we first need an objective way of measuring it. Pinpointing a set of biomarkers that keeps time throughout the body has been a four-year challenge,” explained 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. “My goal in inventing this clock is to help scientists improve their understanding of what speeds up and slows down the human aging process.”

To create the clock, Horvath focused on methylation, a naturally occurring process that chemically alters DNA. Horvath sifted through 121 sets of data collected previously by researchers who had studied methylation in both 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. To create the clock, he zeroed in on 353 markers that change with age and are present throughout the body.

Horvath tested the clock’s effectiveness by comparing a tissue’s biological age to its chronological age. When the clock repeatedly proved accurate, he was thrilled—and a little stunned.

 IMAGE: This is Steven Horvath, Ph.D., UCLA geneticist and biostatistician.

Click here for more information. 

“It’s surprising that one could develop a clock that reliably keeps time across the human anatomy,” he admitted. “My approach really compared apples and oranges, or in this case, very different parts of the body: the brain, heart, lungs, liver, kidney and cartilage.”

While most samples’ biological ages matched their chronological ages, others diverged significantly. For example, Horvath discovered that a woman’s breast tissue ages faster 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.”

The results may explain why breast cancer is the most common cancer in women. Given that the clock ranked tumor tissue an average of 36 years older than healthy tissue, it could also explain why age is a major risk factor for many cancers in both genders.

Horvath next looked at pluripotent stem cells, adult cells that have been reprogrammed to an embryonic stem cell–like state, enabling them to form any type of cell in the body and continue dividing indefinitely.

“My research shows that all stem cells are newborns,” he said. “More importantly, the process of transforming a person’s cells into pluripotent stem cells resets the cells’ clock to zero.”

In principle, the discovery proves that scientists can rewind the body’s biological clock and restore it to zero.

“The big question is whether the biological clock controls a process that leads to aging,” Horvath said. “If so, the clock will become an important biomarker for studying new therapeutic approaches to keeping us young.”

Finally, Horvath discovered that the clock’s rate speeds up or slows down depending on a person’s age.

“The clock’s ticking rate isn’t constant,” he explained. “It ticks much faster when we’re born and growing from children into teenagers, then slows to a constant rate when we reach 20.”

In an unexpected finding, the cells of children with progeria, a genetic disorder that causes premature aging, appeared normal and reflected their true chronological age.

UCLA has filed a provisional patent on Horvath’s clock. His next studies will examine whether stopping the body’s aging clock halts the aging process–or increases cancer risk. He’ll also explore whether a similar clock exists in mice.

 

 

 

October 21, 2013 Posted by | Medical and Health Research News | , , , , , , | Leave a comment

   

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