X-Message-Number: 13374 Date: Wed, 8 Mar 2000 18:10:20 -0800 (PST) From: Doug Skrecky <> Subject: sod, motor neurons and drosophila longevity Citations: 1-3 <1> Authors Mockett RJ. Orr WC. Rahmandar JJ. Benes JJ. Radyuk SN. Klichko VI. Sohal RS. Institution Department of Biological Sciences, Southern Methodist University, Dallas, Texas 75275, USA. Title Overexpression of Mn-containing superoxide dismutase in transgenic Drosophila melanogaster. Source Archives of Biochemistry & Biophysics. 371(2):260-9, 1999 Nov 15. Abstract The general objective of this study was to examine the role of mitochondria in the aging process. Two alternative hypotheses were tested: (i) that overexpression of Mn superoxide dismutase (Mn SOD) in the mitochondria of Drosophila melanogaster would slow the accrual of oxidative damage and prolong survival or (ii) that there is an evolved optimum level of superoxide anion radical, such that overexpression of Mn SOD would have deleterious or neutral effects. Microinjection and mobilization of a transgene, which contained a 9-kb genomic sequence encoding Mn SOD, produced 15 experimental lines overexpressing Mn SOD by 5-116% relative to the parental y w strain. Comparisons between these lines and control lines containing inserted vector sequences alone indicated that the mean longevity of the experimental lines was decreased by 4-5% relative to controls. There were no compensatory changes in the metabolic rate, level of physical activity, or the levels of other antioxidants, namely Cu-Zn SOD, catalase, and glutathione. There were no differences between groups in rates of mitochondrial hydrogen peroxide release, protein oxidative damage, or resistance to 100% oxygen or starvation conditions. The experimental lines had a marginally increased resistance to moderate heat stress. These results are consistent with the existence of an optimum level of Mn SOD activity which minimizes oxidative stress. The naturally evolved level of Mn SOD activity in Drosophila appears to be near the optimum required under normal conditions, although the optimum may be shifted to a higher level under more stressful conditions. Copyright 1999 Academic Press. <2> Authors Hari R. Burde V. Arking R. Institution Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202, USA. Title Immunological confirmation of elevated levels of CuZn superoxide dismutase protein in an artificially selected long-lived strain of Drosophila melanogaster. Source Experimental Gerontology. 33(3):227-37, 1998 May. Abstract Oxidative stress-induced damage is a major causal factor leading to the loss of function characteristic of the aging process. Various antioxidant defenses are marshalled by the organism so as to combat this oxidative damage and delay the onset of senscence. CuZnSOD is one of the major antioxidant enzymes and has been shown to play an important role in the extended longevity of Drosophila melanogaster. Although assays exist with which to measure the CuZnSOD RNA prevalence and enzyme activity, there existed no antibodies that permitted the measurement of the actual amount of Drosophila enzyme protein present. Development of such a tool would enhance our ability to understand mechanisms of antioxidant gene expression in this organism. We have developed a polyclonal antibody against synthetic SOD peptides that is specific for Drosophila CuZnSOD as shown by Western blots. It is very sensitive when tested against native Drosophila CuZnSOD protein. Its use in our experimental system confirms the prior RNA and enzyme activity measurements that indicate that our genetically selected long-lived strain has significantly higher levels of CuZnSOD protein than does the appropriate control strain. <3> Authors Parkes TL. Elia AJ. Dickinson D. Hilliker AJ. Phillips JP. Boulianne GL. Institution Department of Molecular Biology and Genetics, University of Guelph, Ontario, Canada. Title Extension of Drosophila lifespan by overexpression of human SOD1 in motorneurons [comment] [see comments]. Comments Comment on: Nat Genet 1998 Jun;19(2):105-6, Comment in: Nat Genet 1998 Jun;19(2):103, 104 Source Nature Genetics. 19(2):171-4, 1998 Jun. Abstract Reactive oxygen (RO) has been identified as an important effector in ageing and lifespan determination. The specific cell types, however, in which oxidative damage acts to limit lifespan of the whole organism have not been explicitly identified. The association between mutations in the gene encoding the oxygen radical metabolizing enzyme CuZn superoxide dismutase (SOD1) and loss of motorneurons in the brain and spinal cord that occurs in the life-shortening paralytic disease, Familial Amyotrophic Lateral Sclerosis (FALS; ref. 4), suggests that chronic and unrepaired oxidative damage occurring specifically in motor neurons could be a critical causative factor in ageing. To test this hypothesis, we generated transgenic Drosophila which express human SOD1 specifically in adult motorneurons. We show that overexpression of a single gene, SOD1, in a single cell type, the motorneuron, extends normal lifespan by up to 40% and rescues the lifespan of a short-lived Sod null mutant. Elevated resistance to oxidative stress suggests that the lifespan extension observed in these flies is due to enhanced RO metabolism. These results show that SOD activity in motorneurons is an important factor in ageing and lifespan determination in Drosophila. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=13374