Project description:Sir2 is the most intensively discussed longevity gene in current aging research. Although the gene encoding for a NAD+-dependent histone deacetylase initially was found to extend lifespan of various organisms ranging from yeast to mammals, serious doubts regarding its role in longevity have been expressed recently. In this study, we tested whether tissue-specific overexpression of Sir2 in the adult fat body can extend lifespan when compared to genetically identical controls. We also wanted to elucidate the mechanisms by which fat body Sir2 promotes longevity by studying the phenotypic and transcriptional changes in the fat body. We found that moderate (3-fold) Sir2 overexpression in the fat body during adulthood only can promote longevity in both sexes by roughly 13 %. In addition, we obtained transcriptional profiles elicited by this overexpression and propose a role for Sir2 in lipid droplet biology especially under conditions of starvation. Furthermore, our data do not support the idea of Sir2 mediating the response to dietary restriction (DR) because transcriptional profiles of fat bodies after DR or Sir2 overexpression do not match. This study provides additional independent evidence for the concept of Sir2 as a longevity gene and as a promising pharmacological target to cure age-related diseases.
Project description:Sir2 is the most intensively discussed longevity gene in current aging research. Although the gene encoding for a NAD+-dependent histone deacetylase initially was found to extend lifespan of various organisms ranging from yeast to mammals, serious doubts regarding its role in longevity have been expressed recently. In this study, we tested whether tissue-specific overexpression of Sir2 in the adult fat body can extend lifespan when compared to genetically identical controls. We also wanted to elucidate the mechanisms by which fat body Sir2 promotes longevity by studying the phenotypic and transcriptional changes in the fat body. We found that moderate (3-fold) Sir2 overexpression in the fat body during adulthood only can promote longevity in both sexes by roughly 13 %. In addition, we obtained transcriptional profiles elicited by this overexpression and propose a role for Sir2 in lipid droplet biology especially under conditions of starvation. Furthermore, our data do not support the idea of Sir2 mediating the response to dietary restriction (DR) because transcriptional profiles of fat bodies after DR or Sir2 overexpression do not match. This study provides additional independent evidence for the concept of Sir2 as a longevity gene and as a promising pharmacological target to cure age-related diseases. 6 groups of sample types were included in the experiment: a) females overexpressing Sir2 in the fat body b) female controls c) males overexpressing Sir2 in the fat body d) male controls e) wildtype females subjected to DR f) wildtype females feeding on a normal diet. 3 biological replicates were included per group.
Project description:Expression data from four different lifespan-extending conditions: dietary restriction in two different genetic backgrounds (canton-s and a yw, w1118 combination), sir2 overexpression and p53 knockdown (+/-). Comparison of significantly over and under-expressed genes reveals a signature for dietary restriction and lifespan extension. Abstract A major challenge in translating the positive effects of dietary restriction (DR) for the improvement of human health is the development of therapeutic mimics. One approach to finding DR mimics is based upon identification of the proximal effectors of DR life span extension. Whole genome profiling of DR in Drosophila shows a large number of changes in gene expression, making it difficult to establish which changes are involved in life span determination as opposed to other unrelated physiological changes. We used comparative whole genome expression profiling to discover genes whose change in expression is shared between DR and two molecular genetic life span extending interventions related to DR, increased dSir2 and decreased Dmp53 activity. We find twenty-one genes shared among the three related life span extending interventions. One of these genes, takeout, thought to be involved in circadian rhythms, feeding behavior and juvenile hormone binding is also increased in four other life span extending conditions: Rpd3, Indy, chico and methuselah. We demonstrate takeout is involved in longevity determination by specifically increasing adult takeout expression and extending life span. These studies demonstrate the power of comparative whole genome transcriptional profiling for identifying specific downstream elements of the DR life span extending pathway. 42 samples were used in the analysis. Sir2 overexpression flies and the yw, w1118 background DR flies had the same control. Flies were collected at ages 10 and 40 days. Tissue is whole body females.
Project description:Since healthspan-extending interventions such as caloric restriction or fasting robustly promote lipid catabolism, we investigated how lifespan and healthspan were affected by increased lipid catabolism via bmm (brummer, FBgn0036449), the major triglyceride hydrolase in Drosophila. Global overexpression of bmm strongly promoted lifespan extension as well as numerous markers of healthspan, including increased female fecundity, fertility maintenance, preserved locomotion activity, increased mitochondrial biogenesis and oxidative metabolism. Increased Bmm robustly upregulated the heat shock protein 70 (Hsp70) family of proteins, which equipped the flies with higher resistance to heat, cold, and ER stress via improved proteostasis. Overexpression of bmm recapitulated major physiological changes associated with dietary restriction (DR) and conveyed its effects through dSir2. Taken together, these data show that bmm overexpression has broad beneficial effects on healthspan, and implicate lipolysis as a key node underlying the beneficial effects of dietary interventions known to improve healthspan.
Project description:we performed proteome sequencing in Drosophila at day 7 (young) and day 42 (old) under dietary restriction (DR)and ad libitum (AL) conditions.