309 research outputs found
Could cancer drugs provide ammunition against aging?
Recent advances in our understanding of the molecular and cellular signaling pathways that drive aging have revealed several genetic and environmental manipulations that can increase lifespan across different species. Research on the underlying biology of aging has not only revealed it to be a biologically malleable process but has also paved the way for the development of pharmacological interventions that could increase lifespan and delay the onset and/or progression of age-related disease
Higher-capacity communication links based on two-mode phase-sensitive amplifiers
Optical communication links are usually made with erbium-doped fiber amplifiers, which amplify the signal waves in a phase-insensitive (PI) manner. They can also be made with parametric fiber amplifiers, in which the signal waves interact with idler waves. If information is transmitted using only the signals, parametric amplifiers are PI and their noise figures are comparable to those of erbium amplifiers. However, transmitting correlated information in the signals and idlers, or copying the signals prior to transmission, allows parametric amplifiers to be phase-sensitive (PS), which lowers their noise figures. The information capacities of two-mode PS links exceed those of the corresponding PI links by 2 b/s-Hz
Using answer set programming to integrate RNA expression with signalling pathway information to infer how mutations affect ageing.
A challenge of systems biology is to integrate incomplete knowledge on pathways with existing experimental data sets and relate these to measured phenotypes. Research on ageing often generates such incomplete data, creating difficulties in integrating RNA expression with information about biological processes and the phenotypes of ageing, including longevity. Here, we develop a logic-based method that employs Answer Set Programming, and use it to infer signalling effects of genetic perturbations, based on a model of the insulin signalling pathway. We apply our method to RNA expression data from Drosophila mutants in the insulin pathway that alter lifespan, in a foxo dependent fashion. We use this information to deduce how the pathway influences lifespan in the mutant animals. We also develop a method for inferring the largest common sub-paths within each of our signalling predictions. Our comparisons reveal consistent homeostatic mechanisms across both long- and short-lived mutants. The transcriptional changes observed in each mutation usually provide negative feedback to signalling predicted for that mutation. We also identify an S6K-mediated feedback in two long-lived mutants that suggests a crosstalk between these pathways in mutants of the insulin pathway, in vivo. By formulating the problem as a logic-based theory in a qualitative fashion, we are able to use the efficient search facilities of Answer Set Programming, allowing us to explore larger pathways, combine molecular changes with pathways and phenotype and infer effects on signalling in in vivo, whole-organism, mutants, where direct signalling stimulation assays are difficult to perform. Our methods are available in the web-service NetEffects: http://www.ebi.ac.uk/thornton-srv/software/NetEffects
Evolutionary conservation of transcription factors affecting longevity
Gene expression can be optimised for health and longevity through manipulation of transcription factor (TF) activity. The effects of many such TFs are conserved between animal species indicating evolutionary conservation of underlying mechanisms.
Lifespan-determining TFs regulate a plethora of cellular and organismal functions, including stress resistance, metabolism and growth. They interact with each other both within and between cells. Manipulating their activity in a single cell type can often be sufficient to insure longevity.
The evolutionary conservation of their effects on ageing is most likely a reflection of the conservation of their function in processes, such as reproduction, growth, and metabolism, that are important earlier in life. Their effects on early and late life can, however, often be uncoupled
Issues potentially affecting quality of life arising from long-term medicines use: a qualitative study
Background Polypharmacy is increasing and managing large number of medicines may create a burden for patients. Many patients have negative views of medicines and their use can adversely affect quality of life. No studies have specifically explored the impact of general long-term medicines use on quality of life. Objective To determine the issues which patients taking long-term medicines consider affect their day-to-day lives, including quality of life. Setting Four primary care general practices in North West England Methods Face-to-face interviews with adults living at home, prescribed four or more regular medicines for at least 1 year. Interviewees were identified from primary care medical records and purposively selected to ensure different types of medicines use. Interviews were recorded, transcribed and analysed thematically. Results Twenty-one interviews were conducted and analysed. Patients used an average of 7.8 medicines, 51 % were preventive, 40 % for symptom relief and 9 % treatment. Eight themes emerged: relationships with health professionals, practicalities, information, efficacy, side effects, attitudes, impact and control. Ability to discuss medicines with health professionals varied and many views were coloured by negative experiences, mainly with doctors. All interviewees had developed routines for using multiple medicines, some requiring considerable effort. Few felt able to exert control over medicines routines specified by health professionals. Over half sought additional information about medicines whereas others avoided this, trusting in doctors to guide their medicines use. Patients recognised their inability to assess efficacy for many medicines, notably those used for prophylaxis. All were concerned about possible side effects and some had poor experiences of discussing concerns with doctors. Medicines led to restrictions on social activities and personal life to the extent that, for some, life can revolve around medicines. Conclusion There is a multiplicity and complexity of issues surrounding medicines use, which impact on day-to-day lives for patients with long-term conditions. While most patients adapt to long-term medicines use, others did so at some cost to their quality of life
Genome-wide dFOXO targets and topology of the transcriptomic response to stress and insulin signalling
FoxO transcription factors, inhibited by insulin/insulin-like growth factor signalling (IIS), are crucial players in numerous organismal processes including lifespan. Using genomic tools, we uncover over 700 direct dFOXO targets in adult female Drosophila. dFOXO is directly required for transcription of several IIS components and interacting pathways, such as TOR, in the wild-type fly. The genomic locations occupied by dFOXO in adults are different from those observed in larvae or cultured cells. These locations remain unchanged upon activation by stresses or reduced IIS, but the binding is increased and additional targets activated upon genetic reduction in IIS. We identify the part of the IIS transcriptional response directly controlled by dFOXO and the indirect effects and show that parts of the transcriptional response to IIS reduction do not require dfoxo. Promoter analyses revealed GATA and other forkhead factors as candidate mediators of the indirect and dfoxoindependent effects. We demonstrate genome-wide evolutionary conservation of dFOXO targets between the fly and the worm Caenorhabditis elegans, enriched for a second tier of regulators including the dHR96/daf-12 nuclear hormone receptor. Molecular Systems Biology 7: 502; published online 21 June 2011; doi:10.1038/msb.2011.3
Implementation of standard testbeds for numerical relativity
We discuss results that have been obtained from the implementation of the
initial round of testbeds for numerical relativity which was proposed in the
first paper of the Apples with Apples Alliance. We present benchmark results
for various codes which provide templates for analyzing the testbeds and to
draw conclusions about various features of the codes. This allows us to sharpen
the initial test specifications, design a new test and add theoretical insight.Comment: Corrected versio
Of FOXes and Forgetful Worms
Age-related cognitive decline is one of the most haunting aspects of human aging. In a recent publication, Coleen Murphy and colleagues (Kaletsky et al., 2016) describe the transcriptional program that maintains youthful function of aging neurons in the nematode worm
Myc mouse and anti-ageing therapy
Reduction in the expression and activity of a well-known proto-oncogene, Myc, has a beneficial effect on mouse health and survival to old age, in part independently of cancer impact, a recent study reveals. Is this new anti-ageing intervention pointing a way towards new treatments for age-related diseases
Increased mitochondrial and lipid metabolism is a conserved effect of Insulin/PI3K pathway downregulation in adipose tissue
The Insulin/IGF-1 signalling (IIS) pathway plays an essential role in the regulation of glucose and
lipid homeostasis. At the same time, a reduction in the IIS pathway activity can extend lifespan and
healthspan in various model organisms. Amongst a number of body organs that sense and respond to
insulin/IGF-1, the adipose tissue has a central role in both the metabolic and lifespan efects of IIS at
the organismal level. Genetic inactivation of IIS components specifcally in the adipose tissue has been
shown before to improve metabolic profle and extend lifespan in various model organisms. We sought
to identify conserved molecular mechanisms that may underlie the benefcial efects of IIS inhibition
in the adipose tissue, specifcally at the level of phosphoinositide 3-kinase (PI3K), a key IIS efector
molecule. To this end, we inactivated PI3K by genetic means in the fy fat body and by pharmacological
inhibition in mammalian adipocytes. Gene expression studies revealed changes to metabolism and
upregulation of mitochondrial activity in mouse adipocytes and fy fat bodies with downregulated
PI3K, which were confrmed by biochemical assays in mammalian adipocytes. These data suggest that
PI3K inactivation has a conserved efect of upregulating mitochondrial metabolism in both fy and
mammalian adipose tissue, which likely contributes to the health- and life-span extending efect of IIS
pathway downregulation
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