The Cedars-Sinai team in LA – who performed the world’s first cardiac stem cell infusion in 2009 – have shown cardiac stem cell infusions can reverse aging. They found the rats in the study had longer telomeres (the caps on the ends of chromosomes) which protects cells
Scientists have successfully reversed aging in rats’ hearts – paving the way to a treatment for humans.
Researchers at Cedars-Sinai Heart Institute injected fresh cardiac cells from newborn lab rats into old rats.
Previously, this experimental method has only been used as a way to repair damage after a heart attack.
But in this study, the Los Angeles-based team – who performed the world’s first cardiac stem cell infusion in 2009 – have demonstrated it can also reverse aging.
Experts say the breakthrough could revolutionize medicine.
In the study, 22-month-old rats – who were considered old – received stem cells from four-month-old rats.
Across the board, all of them experienced improved heart function, improved their exercise capacity by an average of 20 percent, and regrew hair faster than rats that didn’t receive the cells.
They also demonstrated longer heart cell telomeres – compound structures located at the ends of chromosomes that shrink with age.
‘Our previous lab studies and human clinical trials have shown promise in treating heart failure using cardiac stem cell infusions,’ said lead author Dr Eduardo Marbán, director of the Cedars-Sinai Heart Institute.
‘Now we find that these specialized stem cells could turn out to reverse problems associated with aging of the heart.’
Stem cells are a basic type of cell that can change into another type of more specialized cell through a process known as differentiation.
Similar to a fresh ball of clay, they can be shaped and morphed into any cell in the body.
They grow in embryos as embryonic stem cells, used to help the rapidly growing baby form the millions of different cell types it needs to grow before birth.
In adults they are used as repair cells, used to replace those we lose through damage or ageing.
Stem cells have been the focus of lots of medical research in recent decades because they can be used to grow almost any type of cell.
Dr Marbán developed the process to grow cardiac-derived stem cells when he was on the faculty of Johns Hopkins University, and further developed it at Cedars-Sinai.
In 2009, his team successfully repaired the damaged heart of a man who had suffered a heart attack, using his own heart tissue.
In the latest study, Dr Marbán’s team injected cardiosphere-derived cells, a specific type of stem cell, from newborn laboratory rats into the hearts of rats with an average age of 22 months, which is considered aged.
Other laboratory rats from the same age group were assigned to receive placebo treatment, saline injections instead of stem cells.
Both groups of aged rats were compared to a group of young rats with an average age of four months.
Baseline heart function was measured in all rats, using echocardiograms, treadmill stress tests and blood analysis.
The group of older rats underwent an additional round of testing one month after receiving cardiosphere-derived cells that came from young rats.
‘The way the cells work to reverse aging is fascinating,’ Dr Marbán said.
‘They secrete tiny vesicles that are chock-full of signaling molecules such as RNA and proteins. The vesicles from young cells appear to contain all the needed instructions to turn back the clock.’
This experimental method has only been used as a way to repair damage after a heart attack
‘This study didn’t measure whether receiving the cardiosphere-derived cells extended lifespans, so we have a lot more work to do,’ said Dr Lilian Grigorian-Shamagian, co-primary investigator and the first author of the study.
‘We have much to study, including whether CDCs need to come from a young donor to have the same rejuvenating effects and whether the extracellular vesicles are able to reproduce all the rejuvenating effects we detect with CDCs.’
The team is also studying the use of stem cells to treat patients with Duchenne muscular dystrophy, and patients with heart failure with preserved ejection fraction, a condition that affects more than 50 percent of all heart failure patients.