Young Stem Cells Stop Rapid Aging in Mice
Injection of young progenitor cells resembling in function stem cells derived from young animals stops aging in mice bred to age too quickly, scientists from the University of Pittsburgh School of Medicine demonstrate. In contrast to untreated mice, mice which got cell injections lived two to three times longer and had their health improved. The study results were published in the Jan. 3 edition of Nature Communications.
While previous studies have revealed poor replication and differentiation of stem cell in tissues in old age, it was not clear whether stem cell function loss caused the aging process or vice versa. With their experiments with mice having progeria, a disorder of quick ageing, the researchers concluded that stem cell dysfunctions drive aging process.
The scientists studied muscle stem cells / progenitor cells of progeria mice which, in contrast to cells from healthy mice, were less numerous, did not replicate and differentiate into specialized cells that readily and were less able to regenerate dagamed muscles. The same defects were observed in muscle stem cells of old mice.
To see if the stem cell treatment would help, the researchers injected into the abdomens of progeria mice stem cells from young healthy rodents. With the average lifespan of 21 to 28 days in progeria mice, the researchers observed some of them living beyond 66 days after the injection. These mice also did not develop symptoms of muscle mass loss observed in the control group, such as weakening of the hind limbs, trembling, and slow awkward movement. Moreover, in the treated rodents, new blood vessels appeared in the brain and muscles, though no progenitor / stem cells were detected in those tissues.
The latter has shown that injected in the abdomen stem / progenitor cells did not migrate to any particular place . Due to this, the researchers made a conclusion that the healthy stem cells secrete factors that help correct dysfunctions present in the organism. The same conclusion was made when the experiment was carried out in the culture dish. Though young stem cells were not touching stem cells from progeria mice, the functioning of the latter improved. The researchers expect that young stem cell injections would boost rejuvenating processes in the normal aging organism as well and plan to conduct the further research.