Steven N. Austad, Ph.D.Professor
Purdue University, 1981
Department of Cellular and Structural Biology and
The Barshop Center for Longevity and Aging Studies
Dr. Austad writes a biweekly newspaper column "On Aging" for the San Antonio Express-News. Links to his columns can be found at The Barshop Center for Longevity and Aging Studies website!
Dr. Austad joined the Department of Cellular and structural Biology faculty in June 2004. A Fellow of the Gerontological Society of America since 1993, he is also a past recipient of the Robert W. Kleemeier Award (2003) for outstanding research and the Geron Corporation-Samuel Goldstein Distinguished Publication Award (1994) from that Society. He received as well the Nathan A. Shock Award (1994) from the Gerontological Research Center of the National Institute on Aging. He currently serves on the editorial board of seven journals, including Neurobiology of Aging, Aging Cell, Journals of Gerontology: Biological Sciences, and The Journal of Population Ageing. With Dr. Edward J. Masoro, he co-edited the 5th (2001), 6th (2006) and 7th (2010) Editions of the Handbook of the Biology of Aging. He continues to serve (since 2001) on the Initial Review Group for aging grants of the Ellison Medical Foundation and is currently Research Committee Chair for the American Federation for Aging Research. In addition, he co-directs (with Dr. Gary Ruvkun, Harvard University) the 3-week summer course on the Molecular Biology of Aging at the Woods Hole Marine Biological Laboratory.
Dr. Austad maintains a keen interest in the communication of science to the general public, and in that capacity has served on the Science Advisory Board of National Public Radio (1992-1997) and has been a consultant to the Oregon Museum of Science and Industry and the American Museum of Natural History in New York City. He has written popular science articles for numerous publications including Natural History magazine, Scientific American, National Wildlife, and International Wildlife. His trade book, Why We Age (1997), has been translated into 8 languages. He is currently working on a new book - Methusaleh's Zoo - about the natural history of exceptionally long life. Dr. Austad also directs the biology of aging training grant and is co-leader of the Biology of Aging Track.
A major puzzle in biology is why some species live short lives with rapid physical decay and others live much longer, senescing slowly. Attempting to identify the underlying cellular and molecular mechanisms that account for such species differences is the basis of Dr. Austad's research in comparative biogerontology. A second interest of the laboratory is in development methods for the assessment of animal healthspan, so that the impact on health (as well as longevity) of potential senescence-retarding therapies can be investigated. More detail on these general interests is given below.
Current Lab Projects:
1. Assessment of Animal Healthspan
For too long, the study of aging has focused only on how long animals live rather than how well they live. The laboratory is working on develop and refine physiological, kinesthetic, and behavioral metrics to define mouse and marmoset healthspan. Assays include 24 hour metabolic rate and activity patterns, muscle strength, motor coordination, nerve conduction velocity and a variety of cognitive tests.
2. Impact of Rapamycin on Mouse Healthspan
In 2009, it was reported that the drug rapamycin, which inhibits the TOR pathway, significantly extends the lifespan of 20 month old mice (the human equivalent of about 60 years of age). The lab is now investigating how rapamycin begun either late or early in life affects the details of healthspan.
3. Development of the Marmoset as a Model for Aging Research
The marmoset is a small (rat-sized) primate which offer manifold advantages for the study of aging. Because it is short-lived for a primate yet cognitively sophisticated, the marmoset is being developed as an intermediate animal model between mice and humans for evaluating senescence-retarding therapies. A key feature of developing this species for aging research is defining metrics of marmoset healthspan, particularly in the cognitive realm. The laboratory is now working on the development of these measures.
(Marmosets pictured at left)
4. Mechanisms of Exceptional Longevity in Bivalve Molluscs
No other animal group lives as long as the bivalve mollusks (clams, scallops, oyster). More than 10 species are known to live at least a century, with one species (the ocean quahog) well-documented to live more than 400 years. This project compares mitochondrial function, proteome stability, and stress resistance in seven species of mollusks, ranging in longevity from one year to more than 400 years.
(Clam pictured at left)
5. Comparative Biology of Mammalian Aging
The lifespan of mammals in the wild ranges over more than 100-fold difference. The mammalian comparative aging project uses cells and tissues from a wide variety of mammal species, carefully chosen for their longevity, the evolutionary relationships among one another, and their body size, to evaluate hypotheses concerning the cellular, molecular, and endocrinological pathways that affect mammalian aging rate.
6. Hydra: New Invertebrate Models for Aging Research
Hydra, because of their remarkable powers of regeneration, have been studied in the laboratory for more than two centuries. However, two recent findings have made them of special interest as informative model animals in the biology of aging. First, although hydra had previously been reported to avoid aging altogether, under certain environmental conditions, they begin to age rapidly. Thus, by comparing non-aging and rapidly aging forms of the same species, we should be able gain insight into the molecular mechanisms affecting aging. Second, DNA sequencing of a related cnidarian species discovered that more than 10% of its genes sre shared with mammals, but absent in the two major animal models of aging, the worm C. elegans and the fruitfly Drosophila melanogaster. Thus hydra offer the opportunity to discover novel molecular pathways modulating aging that are not available in current model systems.
Austad SN. (2012) Ageing: Mixed results for dieting monkeys. Nature. 2012 Sep 13; 489(7415):210-11.
Hinojosa CA, Mgbemena V, Van Roekel S, Austad SN, Miller RA, Bose S, Orihuela CJ. (2012)
Enteric-delivered rapamycin enhances resistance of aged mice to pneumococcal pneumonia through reduced cellular senescence. Exp Gerontol. 2012 Sep 7. pii: S0531-5565(12)00250-1. doi: 10.1016/j.exger.2012.08.013.
Nussey DH, Froy H, Lemaitre JF, Gaillard JM, Austad SN. (2012) Senescence in natural populations of animals: Widespread evidence and its implications for bio-gerontology. Ageing Res Rev. 2012 Aug 4.
Ungvari Z, Csiszar A, Sosnowska D, Philipp EE, Campbell CM, McQuary PR, Chow TT, Coelho M, Didier ES, Gelino S, Holmbeck MA, Kim I, Levy E, Sonntag WE, Whitby PW, Austad SN, Ridgway I. (2012)
Testing Predictions of the Oxidative Stress Hypothesis of Aging Using a Novel Invertebrate Model of Longevity: The Giant Clam (Tridacna Derasa). J Gerontol A Biol Sci Med Sci. 2012 Aug 17.
Halloran J, Hussong SA, Burbank R, Podlutskaya N, Fischer KE, Sloane LB, Austad SN, Strong R, Richardson A, Hart MJ, Galvan V. (2012) Chronic inhibition of mammalian target of rapamycin by rapamycin modulates cognitive and non-cognitive components of behavior throughout lifespan in mice. Neuroscience. 2012 Oct 25; 223:102-13.
Finch CE, Austad SN. (2012) Primate aging in the mammalian scheme: the puzzle of extreme variation in brain aging. Age (Dordr). 2012 Oct;34(5):1075-91.
Austad SN (2010) Sex differences in longevity and aging. In Handbook of the Biology of Aging, 7th Ed., E.J. Masoro & S.N. Austad (eds). Academic Press: San Diego, CA. pp.479-96.
Austad SN (2010) Animal size, metabolic rate, and survival, among and within species. In Comparative Biology of Aging, N.S. Wolf (ed). Springer Science & Business Media, New York. pp. 27-42.
Austad, S.N. (2008) Making sense of biological theories of aging. In Handbook of theories of aging, 2nd Ed. Bengtson VL, Gans D, Putney NM, Silverstein M (eds). Springer Publ., New York. Ch. 8, 147-162.
Austad, SN & Kirkwood, TBL. (2008) Evolutionary theory in aging research. The Molecular Biology of Aging. L. Guarente, L. Partridge, D.C. Wallace (eds). Cold Spring Harbor Press, Cold Spring Harbor, NY. Pp. 95-111. (ISBN 978-087969824-9)
Austad, SN, Finch, CE. (2008) The evolutionary context of human aging and degenerative disease. In SC Stearns & JC Koella (eds). Evolution in health and disease, 2nd Edition. Oxford University Press: Oxford, UK. pp. 301-311. (ISBN13: 978-0-19-920745-9)