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Articles 1 - 7 of 7

Full-Text Articles in Social and Behavioral Sciences

The Extracellular Chaperone Clusterin Sequesters Oligomeric Forms Of The Amyloid-Beta 1-40 Peptide, Priyanka Narayan, Angel Orte, Richard Clarke, Benedetta Bolognesi, Sharon Hook, Kristina Ganzinger, Sarah Meehan, Mark Wilson, Christopher Dobson, David Klenerman Dec 2011

The Extracellular Chaperone Clusterin Sequesters Oligomeric Forms Of The Amyloid-Beta 1-40 Peptide, Priyanka Narayan, Angel Orte, Richard Clarke, Benedetta Bolognesi, Sharon Hook, Kristina Ganzinger, Sarah Meehan, Mark Wilson, Christopher Dobson, David Klenerman

Mark R Wilson

In recent genome-wide association studies, the extracellular chaperone protein, clusterin, has been identified as a newly-discovered risk factor in Alzheimer's disease. We have examined the interactions between human clusterin and the Alzheimer's disease-associated amyloid-β 1-40 peptide (Aβ 1-40), which is prone to aggregate into an ensemble of oligomeric intermediates implicated in both the proliferation of amyloid fibrils and in neuronal toxicity. Using highly sensitive single-molecule fluorescence methods, we have found that Aβ 1-40 forms a heterogeneous distribution of small oligomers (from dimers to 50-mers), all of which interact with clusterin to form long-lived, stable complexes. Consequently, clusterin is able to …


Polyelectrolyte Complex Materials Consisting Of Antibacterial And Cell-Supporting Layers, Khairul Mat Amin, Kerry Gilmore, Jake Matic, Stephen Poon, Mark Walker, Mark Wilson, Marc In Het Panhuis Dec 2011

Polyelectrolyte Complex Materials Consisting Of Antibacterial And Cell-Supporting Layers, Khairul Mat Amin, Kerry Gilmore, Jake Matic, Stephen Poon, Mark Walker, Mark Wilson, Marc In Het Panhuis

Mark R Wilson

The characterization of a polyelectrolyte complex material comprised of two biopolymers, a chitosan upper layer and a gellan gum under layer, is reported. It is shown that the upper layer of chitosan with incorporated levofloxacin displays an antibacterial activity, while the under layer of a gellan gum/TiO2 composite supports the growth of fibroblastic cells.


Sex-Specific Sod Levels And Dna Damage In Painted Dragon Lizards (Ctenophorus Pictus), Mats Olsson, Mo Healey, Cecile Perrin, Mark Wilson, Michael Tobler Dec 2011

Sex-Specific Sod Levels And Dna Damage In Painted Dragon Lizards (Ctenophorus Pictus), Mats Olsson, Mo Healey, Cecile Perrin, Mark Wilson, Michael Tobler

Mark R Wilson

When groups of individuals differ in activities that may influence the production of reactive molecules, such as superoxide, we expect selection to result in congruent upregulation of antioxidant production in the group(s) most at risk of suffering concomitant erosion of essential tissue and biomolecules, such as DNA. We investigate this in a (near) annual lizard species, the Australian painted dragon (Ctenophorus pictus), in which males and females have fundamentally different lifestyles, with males being overtly conspicuous and aggressive, whereas females are placid and camouflaged. When kept in identical conditions to females in captivity, males had higher levels of superoxide dismutase …


Predictors Of Telomere Content In Dragon Lizards, Cissy Ballen, Mo Healey, Mark Wilson, Michael Tobler, Mats Olsson Dec 2011

Predictors Of Telomere Content In Dragon Lizards, Cissy Ballen, Mo Healey, Mark Wilson, Michael Tobler, Mats Olsson

Mark R Wilson

Telomeres shorten as a consequence of DNA replication, in particular in cells with low production of telomerase and perhaps in response to physiological stress from exposure to reactive oxygen species, such as superoxide. This process of telomere attrition is countered by innate antioxidation, such as via the production of superoxide dismutase. We studied the inheritance of telomere length in the Australian painted dragon lizard (Ctenophorus pictus) and the extent to which telomere length covaries with masscorrected maternal reproductive investment, which reflects the level of circulating yolk precursor and antioxidant, vitellogenin. Our predictors of offspring telomere length explained 72 % of …


A Significant Component Of Ageing (Dna Damage) Is Reflected In Fading Breeding Colors: An Experimental Test Using Innate Antioxidant Mimetics In Painted Dragon Lizards, Mats Olsson, Michael Tobler, Mo Healey, Cecile Perrin, Mark Wilson Dec 2011

A Significant Component Of Ageing (Dna Damage) Is Reflected In Fading Breeding Colors: An Experimental Test Using Innate Antioxidant Mimetics In Painted Dragon Lizards, Mats Olsson, Michael Tobler, Mo Healey, Cecile Perrin, Mark Wilson

Mark R Wilson

A decade ahead of their time, von Schantz et al. united sexual selection and free radical biology by identifying causal links between deep-rooted physiological processes that dictate resistance to toxic waste from oxidative metabolism (reactive oxygen species, ROS), and phenotypic traits, such as ornaments.Ten years later, these ideas have still only been tested with indirect estimates of free radical levels (oxidative stress) subsequent to the action of innate and dietary antioxidants. Here, we measure net superoxide (a selection pressure for antioxidant production) and experimentally manipulate superoxide antioxidation using a synthetic mimetic of superoxide dismutase (SOD), Eukarion 134 (EUK). We then …


Amyloid-Β Oligomers Are Sequestered By Both Intracellular And Extracellular Chaperones, P Narayan, Sarah Meehan, John Carver, Mark Wilson, C M Dobson, D Klenerman Dec 2011

Amyloid-Β Oligomers Are Sequestered By Both Intracellular And Extracellular Chaperones, P Narayan, Sarah Meehan, John Carver, Mark Wilson, C M Dobson, D Klenerman

Mark R Wilson

The aberrant aggregation of the amyloid-β peptide into β-sheet rich, fibrillar structures proceeds via a heterogeneous ensemble of oligomeric intermediates that have been associated with neurotoxicity in Alzheimer’s disease (AD). Of particular interest in this context are the mechanisms by which molecular chaperones, part of the primary biological defenses against protein misfolding, influence Aβ aggregation. We have used single-molecule fluorescence techniques to compare the interactions between distinct aggregation states (monomers, oligomers, and amyloid fibrils) of the AD-associated amyloid-β(1–40) peptide, and two molecular chaperones, both of which are upregulated in the brains of patients with AD and have been found colocalized …


Net Superoxide Levels: Steeper Increase With Activity In Cooler Female And Hotter Male Lizards, Cissy Ballen, Mo Healey, Mark Wilson, Michael Tobler, Erik Wapstra, Mats Olsson Dec 2011

Net Superoxide Levels: Steeper Increase With Activity In Cooler Female And Hotter Male Lizards, Cissy Ballen, Mo Healey, Mark Wilson, Michael Tobler, Erik Wapstra, Mats Olsson

Mark R Wilson

"Ectotherms increase their body temperature in response to ambient heat, thereby elevating their metabolic rate. An often inferred consequence of this is an overall upregulation of gene expression and energetic expenditure, and a concomitant increased production of reactive oxygen species (e. g. superoxide) and, perhaps, a shortened lifespan. However, recent work shows that this may be a superficial interpretation. For example, sometimes a reduced temperature may in fact trigger up-regulation of gene expression. We studied temperature and associated activity effects in male and female Australian painted dragon lizards (Ctenophorus pictus) by allowing the lizards to bask for 4 h versus …