The giant monoliths of Easter Island are worn, but they have endured for centuries. New research suggests that a compound first discovered in the soil of the South Pacific island might help us stand the test of time, too.
Today in the journal Nature, The University of Texas Health Science Center at San Antonio and two collaborating centers reported that the Easter Island compound – called “rapamycin” after the island’s Polynesian name, Rapa Nui – extended the expected lifespan of middle-aged mice by 28 percent to 38 percent. In human terms, this would be greater than the predicted increase in extra years of life if cancer and heart disease were both cured and prevented.
The rapamycin was given to the mice at an age equivalent to 60 years old in humans.
The studies are part of the National Institute on Aging (NIA) Interventions Testing Program, which seeks compounds that might help people remain active and disease-free throughout their lives. The other two centers involved are the University of Michigan at Ann Arbor and Jackson Laboratory in Bar Harbor, Maine.
The Texas study was led by scientists at two institutes at the UT Health Science Center: the Institute of Biotechnology (IBT) and the Barshop Institute for Longevity and Aging Studies.
“I’ve been in aging research for 35 years and there have been many so-called ‘anti-aging’ interventions over those years that were never successful,” said Arlan G. Richardson, Ph.D., director of the Barshop Institute. “I never thought we would find an anti-aging pill for people in my lifetime; however, rapamycin shows a great deal of promise to do just that.”
Discovered in the 1970s, rapamycin was first noted for its anti-fungal properties and later was used to prevent organ rejection in transplant patients. It also is used in stents, which are implanted in patients during angioplasty to keep coronary arteries open. It is in clinical trials for the treatment of cancer.
The new aging experiments found that adding rapamycin to the diet of older mice increased their lifespan. The results were the same in Texas, Michigan and Maine.
“We believe this is the first convincing evidence that the aging process can be slowed and lifespan can be extended by a drug therapy starting at an advanced age,” said Randy Strong, Ph.D., who directs the NIA-funded Aging Interventions Testing Center in San Antonio. He is a professor of pharmacology at the UT Health Science Center and a senior research career scientist with the South Texas Veterans Health Care System.
The findings have “interesting implications for our understanding of the aging process,” said Z. Dave Sharp, Ph.D., director of the Institute of Biotechnology and professor and chairman of the Health Science Center’s Department of Molecular Medicine.
“In addition,” Dr. Sharp said, “the findings have immediate implications for preventive medicine and human health, in that rapamycin is already in clinical usage.”
Aging researchers currently acknowledge only two life-extending interventions in mammals: calorie restriction and genetic manipulation. Rapamycin appears to partially shut down the same molecular pathway as restricting food intake or reducing growth factors.
It does so through a cellular protein called mTOR (mammalian target of rapamycin), which controls many processes in cell metabolism and responses to stress.
A decade ago, Dr. Sharp proposed to his colleagues that mTOR might be involved in calorie restriction. “It seemed like an off-the-wall idea at that time,” Dr. Richardson said.
In 2004, a year after the launch of the NIA Interventions Testing Program, Dr. Sharp submitted a proposal that rapamycin be studied for anti-aging effects. The proposal was approved, and testing centers in San Antonio and elsewhere began to include rapamycin in the diets of mice.
The male and female mice were cross-bred from four different strains of mice to more closely mimic the genetic diversity and disease susceptibility of the human population.
Dr. Strong soon recognized a problem: Rapamycin was not stable enough in food or in the digestive tract to register in the animals’ blood level. He worked with the Southwest Research Institute in San Antonio to improve the bioavailability of the compound through a process called microencapsulation. The reformulated drug was stable in the diet fed to the mice and bypassed the stomach to release in the intestine, where it could more reliably enter the bloodstream.
Older miceThe original goal was to begin feeding the mice at 4 months of age, but because of the delay caused by developing the new formulation, the mice were not started until they were 20 months old – the equivalent of 60 years of age in humans.
The teams decided to try the rapamycin intervention anyway.
“I did not think that it would work because the mice were too old when the treatment was started,” Dr. Richardson said. “Most reports indicate that calorie restriction doesn’t work when implemented in old animals. The fact that rapamycin increases lifespan in relatively old mice was totally unexpected.”
Added Dr. Strong: “This study has clearly identified a potential therapeutic target for the development of drugs aimed at preventing age-related diseases and extending healthy lifespan. If rapamycin, or drugs like rapamycin, works as envisioned, the potential reduction in overall health cost for the U.S. and the world will be enormous.”
Leaders of the other interventions testing centers are Richard Miller, M.D., Ph.D., of the University of Michigan and David Harrison, Ph.D., at the Jackson Laboratories.
About The University of Texas Health Science Center at San Antonio
The University of Texas Health Science Center at San Antonio is the leading research institution in South Texas and one of the major health sciences universities in the world. With an operating budget of $668 million, the Health Science Center is the chief catalyst for the $16.3 billion biosciences and health care sector in San Antonio’s economy. The Health Science Center has had an estimated $36 billion impact on the region since inception and has expanded to six campuses in San Antonio, Laredo, Harlingen and Edinburg. More than 26,400 graduates (physicians, dentists, nurses, scientists and other health professionals) serve in their fields, including many in Texas. Health Science Center faculty are international leaders in cancer, cardiovascular disease, diabetes, aging, stroke prevention, kidney disease, orthopaedics, research imaging, transplant surgery, psychiatry and clinical neurosciences, pain management, genetics, nursing, dentistry and many other fields.
Will Sansom | Newswise Science News
Multi-year study finds 'hotspots' of ammonia over world's major agricultural areas
17.03.2017 | University of Maryland
Diabetes Drug May Improve Bone Fat-induced Defects of Fracture Healing
17.03.2017 | Deutsches Institut für Ernährungsforschung Potsdam-Rehbrücke
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
27.03.2017 | Life Sciences
27.03.2017 | Life Sciences
27.03.2017 | Earth Sciences