Oxidative stress in Duchenne muscular dystrophy: focus on the NRF2 redox pathway

Oxidative stress is involved in the pathogenesis of Duchenne muscular dystrophy (DMD), an X-linked genetic disorder caused by mutations in the dystrophin gene and characterized by progressive, lethal muscle degeneration and chronic inflammation. In this study, we explored the expression and signaling pathway of a master player of the anti-oxidant and anti-inflammatory response, namely NRF2, in muscle biopsies of DMD patients. We classified DMD patients in two age groups (Class I, 0-2 years and Class II, 2-9 years), in order to evaluate the antioxidant pathway expression during the disease progression. We observed that altered enzymatic antioxidant responses, increased levels of oxidized glutathione and oxidative damage are differently modulated in the two age classes of patients and well correlate with the severity of pathology. Interestingly, we also observed a modulation of relevant markers of the inflammatory response, such as heme oxygenase 1 and IL-6, suggesting a link between oxidative stress and chronic inflammatory response. Of note, using a transgenic mouse model, we demonstrated that IL-6 overexpression parallels the antioxidant expression profile and the severity of dystrophic muscle observed in DMD patients. This study advances our understanding of the pathogenic mechanisms underlying DMD and defines the critical role of oxidative stress on muscle wasting with clear implications for disease pathogenesis and therapy in human

Oxidative stress in Duchenne muscular dystrophy: focus on the NRF2 redox pathway

Oxidative stress is involved in the pathogenesis of Duchenne muscular dystrophy (DMD), an X-linked genetic disorder caused by mutations in the dystrophin gene and characterized by progressive, lethal muscle degeneration and chronic inflammation. In this study, we explored the expression and signaling pathway of a master player of the anti-oxidant and anti-inflammatory response, namely NRF2, in muscle biopsies of DMD patients. We classified DMD patients in two age groups (Class I, 0-2 years and Class II, 2-9 years), in order to evaluate the antioxidant pathway expression during the disease progression. We observed that altered enzymatic antioxidant responses, increased levels of oxidized glutathione and oxidative damage are differently modulated in the two age classes of patients and well correlate with the severity of pathology. Interestingly, we also observed a modulation of relevant markers of the inflammatory response, such as heme oxygenase 1 and IL-6, suggesting a link between oxidative stress and chronic inflammatory response. Of note, using a transgenic mouse model, we demonstrated that IL-6 overexpression parallels the antioxidant expression profile and the severity of dystrophic muscle observed in DMD patients. This study advances our understanding of the pathogenic mechanisms underlying DMD and defines the critical role of oxidative stress on muscle wasting with clear implications for disease pathogenesis and therapy in human

Targeting malaria parasites inside mosquitoes:Ecoevolutionary consequences

Proof-of-concept studies demonstrate that antimalarial drugs designed for human treatment can also be applied to mosquitoes to interrupt malaria transmission. Deploying a new control tool is ideally undertaken within a stewardship programme that maximises a drug’s lifespan by minimising the risk of resistance evolution and slowing its spread once emerged. We ask: what are the epidemiological and evolutionary consequences of targeting parasites within mosquitoes? Our synthesis argues that targeting parasites inside mosquitoes (i) can be modelled by readily expanding existing epidemiological frameworks; (ii) provides a functionally novel control method that has potential to be more robust to resistance evolution than targeting parasites in humans; and (iii) could extend the lifespan and clinical benefit of antimalarials used exclusively to treat humans

Concerning RNA-guided gene drives for the alteration of wild populations

Gene drives may be capable of addressing ecological problems by altering entire populations of wild organisms, but their use has remained largely theoretical due to technical constraints. Here we consider the potential for RNA-guided gene drives based on the CRISPR nuclease Cas9 to serve as a general method for spreading altered traits through wild populations over many generations. We detail likely capabilities, discuss limitations, and provide novel precautionary strategies to control the spread of gene drives and reverse genomic changes. The ability to edit populations of sexual species would offer substantial benefits to humanity and the environment. For example, RNA-guided gene drives could potentially prevent the spread of disease, support agriculture by reversing pesticide and herbicide resistance in insects and weeds, and control damaging invasive species. However, the possibility of unwanted ecological effects and near-certainty of spread across political borders demand careful assessment of each potential application. We call for thoughtful, inclusive, and well-informed public discussions to explore the responsible use of this currently theoretical technology. DOI: http://dx.doi.org/10.7554/eLife.03401.00

Nuove prospettive della comunicazione: inclusione di tutti i generi e di tutte le persone nell’UE

Questa recensione presenta i contenuti e l’utilità della guida pubblicata dal Segretariato Generale del Consiglio Europeo intitolata Comunicazione inclusiva all’SGC, la quale si concentra su somiglianze e differenze tra le versioni inglese, tedesca, portoghese e italiana. Sono mostrate alcune delle strategie che possono essere utilizzate per un linguaggio più inclusivo nell’SGC. Ogni versione presenta specificità linguistiche e socio-culturali relative alle singole lingue prese in considerazione e, pertanto, sono mostrati esempi diversi in ogni traduzione del documento. Gli obiettivi sono di ottenere una maggiore consapevolezza del nostro utilizzo del linguaggio orale, scritto e visivo e di invitare il lettore a prestare maggiore attenzione all’identità delle singole persone. L’argomento trattato nella guida è attuale e sempre in evoluzione come lo sono altresì le lingue, le quali sono in costante mutamento. Si offre uno spunto di riflessione su strutture e parole di uso quotidiano, le quali in base ai contesti d’uso possono risultare discriminatorie o rischiano di essere interpretate erroneamente

High-throughput Sorting of Mosquito Larvae for Laboratory Studies and for Future Vector Control Interventions

Background: Mosquito transgenesis offers new promises for the genetic control of vector-borne infectious diseases such as malaria and dengue fever. Genetic control strategies require the release of large number of male mosquitoes into field populations, whether they are based on the use of sterile males (sterile insect technique, SIT) or on introducing genetic traits conferring refractoriness to disease transmission (population replacement). However, the current absence of high-throughput techniques for sorting different mosquito populations impairs the application of these control measures. Methods: A method was developed to generate large mosquito populations of the desired sex and genotype. This method combines flow cytometry and the use of Anopheles gambiae transgenic lines that differentially express fluorescent markers in males and females. Results: Fluorescence-assisted sorting allowed single-step isolation of homozygous transgenic mosquitoes from a mixed population. This method was also used to select wild-type males only with high efficiency and accuracy, a highly desirable tool for genetic control strategies where the release of transgenic individuals may be problematic. Importantly, sorted males showed normal mating ability compared to their unsorted brothers. Conclusions: The developed method will greatly facilitate both laboratory studies of mosquito vectorial capacity requiring high-throughput approaches and future field interventions in the fight against infectious disease vectors

Heterosis Increases Fertility, Fecundity and Survival of Laboratory-Produced F1 Hybrid Males of the Malaria Mosquito Anopheles coluzzii

The success of vector control strategies aiming to decrease disease transmission via the release of sterile or genetically-modified male mosquitoes critically depends on mating between laboratory-reared males and wild females. Unfortunately, mosquito colonization, laboratory rearing, and genetic manipulations can all negatively affect male competitiveness. Heterosis is commonly used to produce domestic animals with enhanced vigor and homogenous genetic background and could therefore potentially improve the mating performance of mass-reared male mosquitoes. Here, we produced enhanced hybrid males of the malaria mosquito Anopheles coluzzii by crossing two strains colonized 35+ and 8 years ago. We compared the amount of sperm and mating plug proteins they transferred to females, as well as their insemination rate, reproductive success and longevity under various experimental conditions. Across experiments widespread adaptations to laboratory mating were detected in the older strain. In large-group mating experiments, no overall hybrid advantage in insemination rates and the amount of sperm and accessory gland proteins transferred to females was detected. Despite higher sperm activity, hybrid males did not appear more fecund. However, individual-male mating and laboratory-swarm experiments revealed that hybrid males, while inseminating fewer females than older inbred males, were significantly more fertile, producing larger mating plugs and drastically increasing female fecundity. Heterotic males also showed increased longevity. These results validate the use of heterosis for creating hybrid males with improved fitness from long-established inbred laboratory strains. Therefore, this simple approach could facilitate disease control strategies based on male mosquito releases with important ultimate benefits to human health

Mating activates the heme peroxidase HPX15 in the sperm storage organ to ensure fertility in Anopheles gambiae

Anopheles gambiae mosquitoes are major African vectors of malaria, a disease that kills more than 600,000 people every year. Given the spread of insecticide resistance in natural mosquito populations, alternative vector control strategies aimed at reducing the reproductive success of mosquitoes are being promoted. Unlike many other insects, An. gambiae females mate a single time in their lives and must use sperm stored in the sperm storage organ, the spermatheca, to fertilize a lifetime’s supply of eggs. Maintenance of sperm viability during storage is therefore crucial to the reproductive capacity of these mosquitoes. However, to date, no information is available on the factors and mechanisms ensuring sperm functionality in the spermatheca. Here we identify cellular components and molecular mechanisms used by An. gambiae females to maximize their fertility. Pathways of energy metabolism, cellular transport, and oxidative stress are strongly regulated by mating in the spermatheca. We identify the mating-induced heme peroxidase (HPX) 15 as an important factor in long-term fertility, and demonstrate that its function is required during multiple gonotrophic cycles. We find that HPX15 induction is regulated by sexually transferred 20-hydroxy-ecdysone (20E), a steroid hormone that is produced by the male accessory glands and transferred during copulation, and that expression of this peroxidase is mediated via the 20E nuclear receptor. To our knowledge, our findings provide the first evidence of the mechanisms regulating fertility in Anopheles, and identify HPX15 as a target for vector control

Nuclear Factors Bind to a Conserved DNA Element That Modulates Transcription of Anopheles gambiae Trypsin Genes

The Anopheles gambiae trypsin family consists of seven genes that are transcribed in the gut of female mosquitoes in a temporal coordinated and mutually exclusive manner, suggesting the involvement of a complex transcription regulatory mechanism. We identified a highly conserved 12-nucleotide motif present in all A. gambiae and Anopheles stephensi trypsin promoters. We investigated the role of this putative trypsin regulatory element (PTRE) in controlling the transcription of the trypsin genes. Gel shift experiments demonstrated that nuclear proteins of A. gambiae cell lines formed two distinct complexes with probes encompassing the PTRE sequence. Mapping of the binding sites revealed that one of the complex has the specificity of a GATA transcription factor. Promoter constructs containing mutations in the PTRE sequence that selectively abolished the binding of either one or both complexes exerted opposite effects on the transcriptional activity of trypsin promoters in A. gambiae and Aedes aegypti cell lines. In addition, the expression of a novel GATA gene was highly enriched in A. gambiae guts. Taken together our data prove that factors binding to the PTRE region are key regulatory elements possibly involved in the blood meal-induced repression and activation of transcription in early and late trypsin genes