HUMAN TELOMERE LENGTH PREDICTS LONGEVITY
The Highly Technical Blackburn Review Has Been Summarized In Layman's Terms For Us Mere Mortals, by Hector Valenzuela Ph. D. An Expert On Human Telomere Biology.
As is customary, the end of the year is accompanied by reflections and the year's best and worst collections. In this spirit, multiple scientific journals publish compilations of breakthrough articles or reviews on specific topics. This year, Science, one of the most influential journals in the scientific community, has a special edition issue with a theme on aging topics (Science, December 4, 2015, Vol. 350, issue 6265). The article's topics ranged from why we outlive our pets and how telomeres length can predict longevity and health to how Sirtuin proteins affect aging, metabolism, and neurodegeneration. We have selected one article and have summarized the review; we hope you find it interesting and informative.
Human Telomere Biology As We Understand It At The Close Of 2015:
The year-end review was written by Elizabeth Blackburn (Nobel Laureate), Elissa Epel, and Jue Lin, which reviews how telomere length can help predict and contribute to aging diseases. This article begins by summarizing basic background information on telomeres: telomeres protect our chromosomes and hence the cell's ability to grow, how telomerase enzyme elongates telomeres and delays cells from reaching their replicative endpoint known as cellular senescence (i.e., becoming old cells) and discusses how proteins that are usually attached to telomeres are required keep cells youthfulness. The Blackburn review discusses the most relevant genetic and clinical information about telomeres.
Human Telomere Biology Important Highlights For 2015:
When DNA is damaged, or abnormalities exist, the telomeres are the regions in your chromosome to "feel" it first. In a sense, telomeres are the "canary in the coal mine" of your DNA. And the damage is often reflected in the length of the telomeres.
It is a mistake to view telomeres length as simply a "cellular clock." This is because some cells can turn on telomerase and elongate their telomeres, essentially resetting the clock. Therefore, the telomere clock model is inaccurate, and other factors must be considered.
The proteins that bind telomeres, known as shelterin, are critical for longevity. If these proteins are mutated, even though your telomeres are long, mutated shelterin proteins will cause accelerated aging.
Mutations in your telomerase enzyme proteins and shelterin proteins will all lead to what is known as Inherited Telomere Syndromes. Inherited Telomere Syndromes are clinically manifested in several ways, such as pulmonary fibrosis, loss of immune function, gastrointestinal disorders, or neuropsychiatric conditions.
Diseases of aging can all be predicted by telomere length. For example, cardiovascular, diabetes, and dementia can all be indicated by the telomere length of the cells in your blood.
Genetic diseases such as but not limited to Duchene muscular dystrophy, Werner, and Bloom syndrome can all be aggravated when telomere length is short and can be alleviated by elongating your telomeres.
Very importantly: healthy telomeres need to be at least 3.81 kb in length to ensure the stability of the DNA and the onset of age-related diseases. To put this in perspective, a healthy middle-aged adult has telomere lengths of ~5 kb, and a newborn has telomere lengths of ~15 kb.
Although at birth, our telomere length is determined mainly by genetic inheritance from our parents, later in life, the environment, life events, and behavior (i.e., exercising, stress or smoking) can influence telomere length, and therefore the likelihood of developing age-related diseases.
These findings discussed in this review highlight the importance of telomere length in the clinical setting and maintaining healthy distances.