Project description:Manipulating the activity of transcription factor (TF) to regulate animal’s longevity is achieved in different species. However, deciphering the pro-longevity transcriptional programme triggered by the TFs activity is challenging. One obstacle is the multifunctional feature of TFs. The physiological functions of single TF could be diverse and tissues-dependent. The other is the gene regulatory network among the TFs, where multiple TFs can have synergetic or antagonistic impact on the same target genes. Here, we show Xbp1s overexpression in gut and fat body can extend lifespan in Drosophila. Importantly, Xbp1s activity triggers distinct transcriptional programmes in the two tissues, and Xbp1s induction in both tissues are beneficial for longevity. Furthermore, we reveal a pro-longevity gene regulatory network in the fat body, where Xbp1s and dFOXO impinge on the same target genes and induce identical transcriptional outcomes. dfoxo overexpression requires Xbp1 to extend lifespan. Lastly, inducing Xbp1u, the precursor of Xbp1s, can also extend lifespan without triggering massive transcriptome change.
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: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 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:The involvement of protein chaperones in aging is intriguing and their potential contribution has, so far, been attributed solely to their central role in proteostasis. Here we show that four protein chaperones from different cellular compartments extend replicative lifespan (RLS) in budding yeast by a common mechanism akin to caloric restriction. The RLS extension relies on the increased direct activation of Snf1 kinase by Hsp90, thereby bypassing the signal on the environmental glucose level. The chaperone-related RLS extension is accompanied by the uncoupling of the respiratory chain. A genomic approach confirmed the repression of glycolysis and cytoplasmic translation, and contrary, activation of gluconeogenesis and fatty acid oxidation. Our results set a novel paradigm for the role of protein chaperones: by modulation of the chaperone expression level one can affect metabolic features such as glucose sensing, fatty acid consumption, respiration rate, and, consequently, modify lifespan. We expect the described mechanism to open new avenues for research in aging and age-related diseases.
Project description:We overexpressed the spliced form of transcription factor XBP1 in mature F442A adipocytes by adenoviral infection. Control virus expressed GFP alone.
Project description:We overexpressed the spliced form of transcription factor XBP1 in mature F442A adipocytes by adenoviral infection. Control virus expressed GFP alone. mouse sXBP1 overexpressed in mouse F442A adipocytes compared to control (GFP alone). Four replicates of each treatment were analyzed.
Project description:Xbp1 is an important regulator of unfolded protein response and lipid metabolism. Its dyregulation has been associcated in human NASH. Feeding a high fat diet with fructose/sucrose to mice causes progressive, fibrosing steatohepatitis. This study is to use RNA-Seq to identify differentially expressed genes in hepatic Xbp1 deficient mice livers fed with a high fat diet compared to controls. Hepatic Xbp1 deficient mice or flox controls were fed either regular chow or a high fat diet (n=4). Samples from each cohort were pooled into two replicates.