SAN ANTONIO (July 26, 2013) — Kryptonite, the only element known to weaken Superman, might not stand up to the mighty naked mole-rat.
The unusually long-lived rodent, native to the Horn of Africa, displays high levels of oxidative stress across different tissues, yet a recent study of two of its kidney proteins found remarkable capacity to ward off oxidative damage. The study is from the Barshop Institute for Longevity and Aging Studies at The University of Texas Health Science Center San Antonio. Naked mole-rats have a maximum life span of 32 years — eight to 10 times longer than the oldest mice of comparable size.
“This observation supports our earlier finding that, compared to short-lived rodents, the naked mole-rat has a unique cellular environment that protects proteins from dysfunction,” said corresponding author Asish Chaudhuri, Ph.D., associate professor of biochemistry in the School of Medicine at the Health Science Center. He conducts research at the Barshop Institute. “Identifying those elements that are protective will potentially open up new avenues for treatment of various diseases, including neurodegenerative diseases where proteins are unstable.”
Oxidative stress theory of aging
A long-held theory of aging is that oxidative stress causes harmful, cumulative effects to our bodies. Naked mole-rat studies are contradicting this theory. These hairless, burrow-dwelling creatures maintain cancer-free good health for at least 75 percent of their extraordinary longevity and show unchanged levels of protein activities and other biochemical traits at ages equivalent to 90-year-old humans.
“The key point of this new paper is that only certain proteins appear to take the brunt of oxidative stress, and they protect potentially more vulnerable proteins,” said co-author Rochelle Buffenstein, Ph.D., professor of physiology and cellular and structural biology in the School of Medicine at the Health Science Center. She directs the Barshop Institute’s naked mole-rat colony, which is the only facility in the world that maintains large numbers of young and aged naked mole-rats in a pathogen-free environment.
Riddles to solve
The authors said oxidative stress may not be the only criteria for impairment of protein function with age. Dr. Buffenstein said it is not known whether the two kidney proteins have other mechanisms in place to maintain their structural stability.
“These are very unexpected observations because the general concept is that oxidative stress leads to protein instability,” Dr. Chaudhuri said.
The paper came out earlier this year in Biochemical and Biophysical Research Communications.
This work was supported by National Institutes of Health/National Institute on Aging pilot grant K07 AG025063 04 (to A.C.) and from NIH/NIA grant RO1AG-022891 (to R.B.).
Elevated protein carbonylation and oxidative stress do not affect protein structure and function in the long-living naked-mole rat: A proteomic approach
Eric M. De Waala, Hanyu Liangb, Anson Piercec, Ryan T. Hamiltone,h, Rochelle Buffensteind,e, Asish R. Chaudhurid,f,g
Biochemical and Biophysical Research Communications, Volume 434, Issue 4, 17 May 2013, Pages 815–819
a Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
b Department of Medicine-Diabetes Division, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
c Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
d Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
e Barshop Institute for Longevity and Aging Studies, South Texas Veterans Health Care System, San Antonio, TX 78229, USA
f Department of Biochemistry, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
g Geriatric Research, Education, and Clinical Center, South Texas Veterans Health Care System, San Antonio, TX 78229, USA
h Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
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