Telomeres, which appear to carry clues to human aging and age-related disorders, have piqued the interest of researchers, journalists, and curious minds. Could telomeres hold the key to answering concerns like “How long will I live?” and “Will I Get Cancer?”
What are telomeres?
Telomeres are DNA structures found at the ends of chromosomes that contain repeated DNA sequences. They prevent chromosomes from unwinding or sticking together by “sealing” them at the tips. Telomeres help protect the DNA sequence of a chromosome when it is copied during cell division. Each time the chromosome is copied, a small amount of DNA is lost because the enzymes that copy DNA are unable to continue to the conclusion of the sequence. Every time a cell divides, telomeres provide a buffer that gets shorter.
Telomeres shorten over time, causing cell division to cease and the cell to die. This mechanism is assumed to limit a cell’s lifespan to a certain number of divisions, making telomere length a cellular aging indicator.
Telomeres and stress
Telomere shortening can be accelerated by environmental stress. Cigarette smoking, radiation, a bad diet, and even psychological stress have all been linked to the disease. Children who spent a considerable portion of their early lives in institutions had shorter telomeres on average than children who got high-quality foster care as part of an intervention trial, according to a recently published study. Telomere shortening has been discovered in adults who were maltreated as children in previous research.
Telomeres and disease
Telomere-less chromosomes can reorganize or fuse together, and these aberrant chromosomes are frequently found in cancer cells. Inheritance of abnormally short telomeres has been linked to disorders like pulmonary fibrosis and bone marrow failure in some families.
Shorter telomeres have been linked to diseases that become more common with age, such as heart disease and cancer, according to several epidemiological studies. The same cell-damaging processes that cause telomere shortening and chronic illnesses, such as oxidative stress and inflammation, could be to blame.
Telomeres and aging
Is the length of your telomere a biomarker for aging? The evidence is ambiguous, according to a comprehensive review released last year. Older adults have shorter telomeres on average, although there is a lot of diversity between persons. It’s unclear if shorter telomeres are just a symptom of aging or play a role in it.
Telomere length and mortality studies have yielded varied results. Only a few studies have tracked people overtime to investigate how telomere length changes are connected with survival. Several investigations are now underway that should throw more light on this topic.
Telomeres and immorality
Telomerase is an enzyme found in germ cells (eggs and sperm) and stems cells that repair telomere length. Telomerase is activated in cancer cells, making them “immortal,” despite the fact that it is generally inactive in most other cells in the body. Although it is theoretically possible to activate telomerase to immortalize normal cells, its feasibility is unknown.
Testing for telomeres
Although telomere research is still in its infancy, some entrepreneurs see human curiosity as an untapped market. Last week, a business in the United Kingdom claimed that it would soon be selling a $700 “biological age” test based on telomere length to the general public (US). Given the current state of science, it does not appear to be a good deal.
The vast majority of the 2,000 or so genetic tests presently in clinical use are for detecting uncommon diseases such as cystic fibrosis. Many more tests are being developed and distributed to the general public via the Internet and other media. Tests based on a small amount of scientific data may not be reliable or useful. Beware of the buyer!
The telomerase gene, which extends telomeres by adding nucleotides to strands of telomere DNA, is spontaneously expressed by some cells in the body. Telomeres, in other words, can be extended by telomerase. Premere promotes telomerase gene expression, while telomerase promotes overall telomere health.