Washington: A new technique can increase the length of human telomeres quickly and efficiently, promising to reverse the ageing process and paving the way for treatment of highly debilitating genetic diseases, scientists say.
Treated cells behave as if they are much younger than untreated cells, multiplying with abandon in the laboratory dish rather than stagnating or dying.
The procedure, which involves the use of a modified type of RNA, will improve the ability of researchers to generate large numbers of cells for study or drug development, scientists said.
Skin cells with telomeres lengthened by the procedure were able to divide up to 40 more times than untreated cells. The research may point to new ways to treat diseases caused by shortened telomeres.
Telomeres are the protective caps on the ends of the strands of DNA called chromosomes, which house our genomes. In young humans, telomeres are about 8,000-10,000 nucleotides long.
They shorten with each cell division, however, and when they reach a critical length the cell stops dividing or dies. This internal "clock" makes it difficult to keep most cells growing in a laboratory for more than a few cell doublings.
"Now we have found a way to lengthen human telomeres by as much as 1,000 nucleotides, turning back the internal clock in these cells by the equivalent of many years of human life," said Helen Blau, professor at the Stanford University School of Medicine.
"This greatly increases the number of cells available for studies such as drug testing or disease modelling," said Blau.
The researchers used modified messenger RNA to extend the telomeres. RNA carries instructions from genes in the DNA to the cell's protein-making factories.
The RNA used in this experiment contained the coding sequence for TERT, the active component of a naturally occurring enzyme called telomerase.
Telomerase is expressed by stem cells, including those that give rise to sperm and egg cells, to ensure that the telomeres of these cells stay in tip-top shape for the next generation. Most other types of cells, however, express very low levels of telomerase.
"This new approach paves the way towards preventing or treating diseases of ageing," said Blau.
"There are also highly debilitating genetic diseases associated with telomere shortening that could benefit from such a potential treatment," said Blau.
The research was published in the FASEB Journal.