A Single Gene Change Can Extend Yeast Life Span: The Role of RAS in Cellular Senescence

Author(s):  
S. Michal Jazwinski ◽  
James B. Chen ◽  
Jiayan Sun
2007 ◽  
Vol 1100 (1) ◽  
pp. 455-469 ◽  
Author(s):  
T. DAVIS ◽  
F. S. WYLLIE ◽  
M. J. ROKICKI ◽  
M. C. BAGLEY ◽  
D. KIPLING

Author(s):  
Sofia Ferreira-Gonzalez ◽  
Daniel Rodrigo-Torres ◽  
Victoria L. Gadd ◽  
Stuart J. Forbes

AbstractCellular senescence is an irreversible cell cycle arrest implemented by the cell as a result of stressful insults. Characterized by phenotypic alterations, including secretome changes and genomic instability, senescence is capable of exerting both detrimental and beneficial processes. Accumulating evidence has shown that cellular senescence plays a relevant role in the occurrence and development of liver disease, as a mechanism to contain damage and promote regeneration, but also characterizing the onset and correlating with the extent of damage. The evidence of senescent mechanisms acting on the cell populations of the liver will be described including the role of markers to detect cellular senescence. Overall, this review intends to summarize the role of senescence in liver homeostasis, injury, disease, and regeneration.


2014 ◽  
Vol 25 (12) ◽  
pp. 1916-1924 ◽  
Author(s):  
David Öling ◽  
Rehan Masoom ◽  
Kristian Kvint

Ubp3 is a conserved ubiquitin protease that acts as an antisilencing factor in MAT and telomeric regions. Here we show that ubp3∆ mutants also display increased silencing in ribosomal DNA (rDNA). Consistent with this, RNA polymerase II occupancy is lower in cells lacking Ubp3 than in wild-type cells in all heterochromatic regions. Moreover, in a ubp3∆ mutant, unequal recombination in rDNA is highly suppressed. We present genetic evidence that this effect on rDNA recombination, but not silencing, is entirely dependent on the silencing factor Sir2. Further, ubp3∆ sir2∆ mutants age prematurely at the same rate as sir2∆ mutants. Thus our data suggest that recombination negatively influences replicative life span more so than silencing. However, in ubp3∆ mutants, recombination is not a prerequisite for aging, since cells lacking Ubp3 have a shorter life span than isogenic wild-type cells. We discuss the data in view of different models on how silencing and unequal recombination affect replicative life span and the role of Ubp3 in these processes.


Author(s):  
Mozhdeh Mehdizadeh ◽  
Martin Aguilar ◽  
Eric Thorin ◽  
Gerardo Ferbeyre ◽  
Stanley Nattel

1995 ◽  
Vol 7 (2) ◽  
pp. 331-336 ◽  
Author(s):  
Judith Alferink ◽  
Birgit Schittek ◽  
Günter Schönrich ◽  
Günter J. Hämmerling ◽  
Bernd Arnold

2014 ◽  
Vol 76 (6) ◽  
pp. 379-383 ◽  
Author(s):  
Melissa A. Hicks ◽  
Rebecca J. Cline ◽  
Angela M. Trepanier

An understanding of how genomics information, including information about risk for common, multifactorial disease, can be used to promote personal health (personalized medicine) is becoming increasingly important for the American public. We undertook a quantitative content analysis of commonly used high school textbooks to assess how frequently the genetic basis of common multifactorial diseases was discussed compared with the “classic” chromosomal–single gene disorders historically used to teach the concepts of genetics and heredity. We also analyzed the types of conditions or traits that were discussed. We identified 3957 sentences across 11 textbooks that addressed multifactorial and “classic” genetic disorders. “Classic” gene disorders were discussed relatively more frequently than multifactorial diseases, as was their genetic basis, even after we enriched the sample to include five adult-onset conditions common in the general population. Discussions of the genetic or hereditary components of multifactorial diseases were limited, as were discussions of the environmental components of these conditions. Adult-onset multifactorial diseases are far more common in the population than chromosomal or single-gene disorders; many are potentially preventable or modifiable. As such, they are targets for personalized medical approaches. The limited discussion in biology textbooks of the genetic basis of multifactorial conditions and the role of environment in modifying genetic risk may limit the public’s understanding and use of personalized medicine.


2018 ◽  
Vol 75 (6) ◽  
pp. 1199-1205
Author(s):  
Fanny Vallet ◽  
Nathalie Mella ◽  
Andreas Ihle ◽  
Marine Beaudoin ◽  
Delphine Fagot ◽  
...  

Abstract Objectives Interindividual differences in cognitive aging may be explained by differences in cognitive reserve (CR) that are built up across the life span. A plausible but underresearched mechanism for these differences is that CR helps compensating cognitive decline by enhancing motivation to cope with challenging cognitive situations. Theories of motivation on cognition suggest that perceived capacity and intrinsic motivation may be key mediators in this respect. Method In 506 older adults, we assessed CR proxies (education, occupation, leisure activities), motivation (perceived capacity, intrinsic motivation), and a global measure of cognitive functioning. Results Perceived capacity, but not intrinsic motivation, significantly mediated the relation between CR and cognitive performance. Discussion Complementary with neurobiological and cognitive processes, our results suggest a more comprehensive view of the role of motivational aspects built up across the life span in determining differences in cognitive performance in old age.


2019 ◽  
Vol 317 (5) ◽  
pp. C953-C963 ◽  
Author(s):  
Fengling Yuan ◽  
Jiejun Zhou ◽  
Lingxiu Xu ◽  
Wenxin Jia ◽  
Lei Chun ◽  
...  

GABA, a prominent inhibitory neurotransmitter, is best known to regulate neuronal functions in the nervous system. However, much less is known about the role of GABA signaling in other physiological processes. Interestingly, recent work showed that GABA signaling can regulate life span via a metabotropic GABAB receptor in Caenorhabditis elegans. However, the role of other types of GABA receptors in life span has not been clearly defined. It is also unclear whether GABA signaling regulates health span. Here, using C. elegans as a model, we systematically interrogated the role of various GABA receptors in both life span and health span. We find that mutations in four different GABA receptors extend health span by promoting resistance to stress and pathogen infection and that two such receptor mutants also show extended life span. Different GABA receptors engage distinct transcriptional factors to regulate life span and health span, and even the same receptor regulates life span and health span via different transcription factors. Our results uncover a novel, profound role of GABA signaling in aging in C. elegans, which is mediated by different GABA receptors coupled to distinct downstream effectors.


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