Hormone Klotho could extend life expectancy and Slow Aging

August 27th 2005

Researchers at the University of Texas Southwestern Medical Center led by Dr. Makoto Kuro-o (M.D., Ph.D.) found that a naturally occurring hormone called Klotho extended the lifespan of mice up to 30%.  They also found that it increases the susceptibility to diabetes and decreases fertility.  The study was reported in the online journal Science Thursday. 

The hormone is produced in the kidney and brain but can leak into the bloodstream. It is the leakage that helped the mice live longer, so it appears. Researchers will be looking into whether people that live longer have an surplus of this hormone in the blood. 

An earlier mice study conducted by Dr. Kuro-o in 1997 found that mice that lacked the hormone had significantly shorter life spans. They found the mice developed ailments including hardening of the arteries, thinning bones, withered skin, and weak lungs.

The Texas team identified a small protein component peptide that the so called Klotho gene produces.  They were able to genetically engineer normal mice by injecting them with this purified peptide.  The genetically engineered male mice lived 31% longer than normal males.  The modified females lived 19% longer.    

There does not appear to be any food or drug that stimulates Klotho secretion.  Dr. Kuro-o told Best Syndication that "At this moment I do not know that there is anything that can stimulate Klotho secretion."  Cells naturally die off as we age.  This is not the same for cancer cells.  Cancer cells do not die but continue to multiply.  This has been a common concern in longevity research.  Dr. Kuro-o told Best Syndication that "We do not observe an increase in cancer in transgenic mice that overexpress Klotho at this moment. Effects of Klotho on cancer remains to be determined."

The team noticed the hormone increased the body’s resistance to insulin.  Previous studies have shown this condition correlates to an extended life span.  Ultra-low calorie diets also increase insulin resistance.

Experiments involving cells in the laboratory indicated the peptide substance modulates a crucial biological pathway involving basic metabolic functions.  It is interesting that the mice did not have an increased level of glucose in their blood which is a primary symptom of diabetes.

Other studies found that “damping down” this insulin/insulin-like growth factor-1 signaling pathway may be the same mechanism that extends longevity in animals that were fed ultra-low calorie diets.  Previous research found that people with a certain variation of the gene are prone to age related diseases like heart attacks, strokes and osteoporosis.

Klotho is named after one of the Greek Goddesses who spins the thread of life controlling the longevity of individual humans.  It is hoped that this could lead to drugs that increase human life spans.

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By Dan Wilson
Best Syndication Staff Writer

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Keywords and misspellings: Klotho clotho ageing aging longevity