Still looking for the elixir of youth? It may be found in a laboratory with a group of scientists using a new method of extending cellular telomere lengths. Their research has shown successful extension of cell life by increasing the lifespan of telomeres, the protective caps for DNA. The researchers used modified RNA which contain instructions encoded from DNA to make the protein telomerase, which produces telomeres. These proteins are typically seen in germ cells and not in somatic cells. Germ cells are cells related to reproductive functions, whereas somatic cells are every other cell in our body, like a skin or muscle cells.
The paper was published in the journal FASEB under the title “Transient delivery of modified mRNA encoding TERT rapidly extends telomeres in human cells” and was co-written by researchers at Stanford University. Their method found that treated cells grew at a much higher rate, about 40 times the size, than cells which were not treated. This amounts to an increase of about 1,000 nucleotides – single units of DNA – to the telomere length. All cells will age and die and have a certain lifespan, based on tissue type. When they were treated, cells in the lab lived past their average life span.
An important advantage in their treatment is the transient property. Their treatment wears off after about 48 hours. This may not seem good at first glance, but it simply allows for cells to be given an extra coating of protective gear. If we extended this principle further, the cell would never die but would continue to grow forever. This is something scientists want to avoid. The extended, immortal life of telomeres is a cellular hallmark of cancer.
Every DNA structure in our body has, at its end, protective caps known as telomeres. They are long strings of repetitive sequences of DNA whose sole purpose is to be destroyed so that the functional DNA is maintained. In young adults they are around 1,000 to 8,000 nucleotides long. DNA replication is a complicated process; it is not perfect and every time our cells divide, some of their DNA become smaller. Without telomeres, a substantial portion of DNA would be destroyed every time our cells divide. Skin cells, to give an example, die quickly because they divide more often and so lose their telomeres the quickest. The idea behind this study is that cellular life can be extended in cells we cannot afford to lose, or those in older people, whose telomere length has been shortened.
Another important property of this particular cellular treatment is that previous attempts at doing this kind of telomere treatment have caused our bodies to react badly due to the immune system developing an immune response against telomerase.
As the study moves forward, researchers continue to replicate and test their results on a wide range of cells. The idea is to eventually use this as a method of treating diseases that deal with aging.
“One day it may be possible to target muscle stem cells in a patient with Duchenne muscular dystrophy, for example, to extend their telomeres. There are also implications for treating conditions of aging such as diabetes and heart disease,” said Helen Blau, co-author and microbiologist at Stanford.