Telomeres: Decades of Research, A Nobel Prize and Your Cellular Health

 

My name is Cal Harley, PhD and I am the Chief Scientist at Telomere Diagnostics, the company that offers TeloYears. As a clinical researcher and scientist, I have been actively involved in telomere biology research for the past 30+ years and am very excited that we are now able to offer TeloYears, a simple genetic test that measures the length of your telomeres, which are the protective caps on the ends of your DNA strands that tend to shorten and fray with age. Work that I and other researchers have done in the past eight decades has shown the amazing role that these fascinating structures on the ends of our chromosomes play in one of life’s most central biological processes – cell division. In multicellular organisms such as humans, cell division gives us the vitally critical ability to replace old worn-out tissues, to grow, to heal.

 

 

Our understanding of telomeres started in 1931 when Hermann Muller and Barbara McClintock first discovered structures on the ends of the chromosomes of both flies and corn, respectively. However, the specific purpose of these structures did not come into focus until much later. In later decades, the longstanding model of “immortal cells” was overturned by the work of Leonard Hayflick who in the 1960’s showed that cells have a self-limiting capacity to replicate. He demonstrated that when a cell can no longer divide, it becomes senescent, the biological equivalent of aging. The association between the self-limiting nature of cellular replication, or the Hayflick Limit as it is now known, and telomeres became increasingly clear in the research done in my lab at McMaster University in the late 1980’s and early 1990’s. We showed that telomere shortening due to the end-replication problem was responsible for the triggering of cellular senescence and the loss of regenerative capacity of human cells that defined the replicative clock of cell aging. Our work suggested that we could measure the rate of telomeric loss and its association with cellular senescence in multiple studies thus confirming the role telomere shortening plays in cell biology.

 

 

In 1984, Elizabeth Blackburn, co-founder of Telomere Diagnostics, profoundly expanded our understanding of telomere biology when she discovered the enzyme telomerase in the ciliate Tetrahymena. Telomerase is a reverse transcriptase, or an enzyme used to generate complementary DNA from an RNA primer, that adds telomere repeat sequences at the end of telomeres. Elizabeth Blackburn continued her research and in 2009 was awarded the Nobel Prize in Physiology or Medicine jointly with Carol Greider and Jack Szostak “for the discovery of how chromosomes are protected by telomeres and enzyme telomerase.”

To date, several thousand studies have been published on telomeres and telomerase in nearly every area of medical research – longevity, cardiovascular health, cancer, diabetes, diet and exercise, depression, arthritis, kidney disease, pulmonary disease, the list goes on and on. Because of their fundamental role in cellular functioning, telomeres continue to be vigorously researched for their role in nearly every known disease state as well as a potential target for therapeutic intervention.

 

 

We founded Telomere Diagnostics back in 2010 with the goal of expanding access to information about individuals’ telomere length in order to empower everyone with information about this important biomarker of cellular reserve. Learning about your DNA enables you to make informed decisions about your lifestyle choices to optimize your health or simply just to know. Genetic services from companies such as AncestryDNA and 23andMe have profoundly impacted the general public’s awareness of and interest in the information that our DNA holds about ourselves and where we come from.

 

 

The TeloYears test provides your age in TeloYears, a metric based on the relative length of your telomeres, one of the components of your DNA that changes over time and is influenced by both genetics and an individual’s accumulated lifestyle choices and experiences. Your telomere length is variable and understanding this pattern of change can provide you with motivation to either start or maintain a healthy lifestyle. It has been said a million times but with the advent of the genetic information age, it is more resonant now than ever: Knowledge is power.

In light of the ever expanding body of clinical data and research in telomere biology, I will be blogging my take on the latest and greatest findings in the weeks and months to come. Even though I am currently sailing through the late summer seas between Copenhagen and the west coast of Norway, I hope to have the time in the evenings to unpack some recent studies about telomeres that have been occupying my thoughts lately. As I sail under the northern night sky and look up at the array of constellations above me, I am reminded of the quote by artist and science fiction writer Vera Nazarian “When you reach for the stars, you are reaching for the farthest thing out there. When you reach deep into yourself, it is the same thing, but in the opposite direction. If you reach in both directions, you will have spanned the universe.”
Cal Harley, PhD