Telomerase, an enzyme naturally found in the human organism, is the closest of all known substances to a “cellular elixir of youth.” In a recent study, Brazilian and US researchers show that sex hormones can stimulate production of this enzyme.
The strategy was tested in patients with genetic diseases associated with mutations in the gene that codes for telomerase, such as aplastic anemia and pulmonary fibrosis. The authors say that the results suggest that the approach can combat the damage caused to the organism by telomerase deficiency.
The study was performed by Brazilian researchers in collaboration with colleagues at the National Institutes of Health (NIH) in the US. Among the scientists involved was Rodrigo Calado, a professor at the University of São Paulo’s Ribeirão Preto Medical School (FMRP-USP) and a member of the Center for Cell-Based Therapy (CTC), one of the Research, Innovation and Dissemination Centers (RIDCs) supported by FAPESP.
“One of the processes associated with aging is progressive shortening of telomeres, DNA-protecting structures at the ends of chromosomes, like the plastic tips on shoelaces,” Calado said. “Each time a cell divides, its telomeres get shorter. Eventually, the cell can’t replicate anymore and dies or becomes senescent. However, telomerase can keep the length of telomeres intact, even after cell division.”
In practice, he added, telomere length is a laboratory measure of a cell’s “age.” Some cells avoid aging by using telomerase to lengthen their telomeres through the addition of DNA sequences, thereby maintaining their capacity to multiply and “stay young.”
In an embryo, where tissue is still in the formative stage, telomerase is expressed by practically every cell. After this period, only cells that are constantly dividing, such as hematopoietic (blood-forming) stem cells, which can differentiate into a variety of specialized cells, continue to produce telomerase.
“Aplastic anemia is one …