5,864 research outputs found

    The essential roles of metal ions in insect homeostasis and physiology

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    Metal ions play distinct roles in living organisms, including insects. Some, like sodium and potassium, are central players in osmoregulation and ‘blood and guts’ transport physiology, and have been implicated in cold adaptation. Calcium is a key player as a second messenger, and as a structural element. Other metals, particularly those with multiple redox states, can be cofactors in many metalloenzymes, but can contribute to toxic oxidative stress on the organism in excess. This short review selects some examples where classical knowledge has been supplemented with recent advances, in order to emphasize the importance of metals as essential nutrients for insect survival

    O-GlcNAcase contributes to cognitive function in Drosophila

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    Contains fulltext : 219183.pdf (publisher's version ) (Open Access

    Anti-Inflammatory activity of a polyphenolic extract from Arabidopsis thaliana in in vitro and in vivo models of Alzheimer's Disease

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    Alzheimer's disease (AD) is the most common neurodegenerative disorder and the primary form of dementia in the elderly. One of the main features of AD is the increase in amyloid-beta (Aβ) peptide production and aggregation, leading to oxidative stress, neuroinflammation and neurodegeneration. Polyphenols are well known for their antioxidant, anti-inflammatory and neuroprotective effects and have been proposed as possible therapeutic agents against AD. Here, we investigated the effects of a polyphenolic extract of Arabidopsis thaliana (a plant belonging to the Brassicaceae family) on inflammatory response induced by Aβ. BV2 murine microglia cells treated with both Aβ25⁻35 peptide and extract showed a lower pro-inflammatory (IL-6, IL-1β, TNF-α) and a higher anti-inflammatory (IL-4, IL-10, IL-13) cytokine production compared to cells treated with Aβ only. The activation of the Nrf2-antioxidant response element signaling pathway in treated cells resulted in the upregulation of heme oxygenase-1 mRNA and in an increase of NAD(P)H:quinone oxidoreductase 1 activity. To establish whether the extract is also effective against Aβ-induced neurotoxicity in vivo, we evaluated its effect on the impaired climbing ability of AD Drosophila flies expressing human Aβ1⁻42. Arabidopsis extract significantly restored the locomotor activity of these flies, thus confirming its neuroprotective effects also in vivo. These results point to a protective effect of the Arabidopsis extract in AD, and prompt its use as a model in studying the impact of complex mixtures derived from plant-based food on neurodegenerative diseases

    A fruitful fly forward : the role of the fly in drug discovery for neurodegeneration

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    AD, Alzheimer’s disease; APP, amyloid precursor protein; BBB, blood brain barrier; GFP, green fluorescent protein; HTS, high-throughput screening; HD, Huntington’s disease; LB, Lewy bodies; PD, Parkinson’s disease; PolyQ, Polyglutamine; RNAi, RNA interference; SNCA, α-synuclein gene; UAS, Upstream Activating Sequence.peer-reviewe

    Establishing a role for specific nutrients in Drosophila dietary restriction

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    Dietary restriction (DR), the reduction in food intake that falls short of starvation, has been shown to be the most robust and reproducible intervention to extend lifespan in diverse organisms ranging from yeast to mammals, including the fruit fly Drosophila. Despite over 70 years of research, primarily on rodents, the mechanisms by which DR extend lifespan in any organism are poorly understood, partially due to the variation in how DR is defined and applied between laboratories. Lifespan extension by DR commonly trade-offs with reduced fecundity, leading to evolutionary-based theories predicting that DR elicits an evolved response to food shortage in nature, through reallocation of resources away from reproduction and towards somatic maintenance, hence increasing the chance of survival until food supply becomes more abundant. In Drosophila, DR is typically implemented by dilution of sucrose and yeast in an agar-based medium, with yeast being the key component regulating lifespan. Firstly, this thesis presents an investigation of the response of the model organism Drosophila to different DR diets and protocols, thereby creating one standardized and optimized DR diet for use. Secondly, using the optimized diet, this project investigates the role of specific nutrients mediating the effects of DR and the potential pathways controlling these effects. Essential amino acids were shown to directly regulate the trade-off between high fecundity and reduced lifespan observed with full feeding. However, methionine addition alone was necessary and sufficient to increase fecundity to levels seen with full feeding, without reducing lifespan, demonstrating that reallocation of nutrients cannot explain the DR responses. The results of this thesis highlight the importance for a standard DR protocol and suggest that in other organisms, including mammals, the beneficial effects of DR may be achieved without impairing fertility by using a suitable balance of nutrients in the diet