Helen May-Simera

Dr. Helen May-Simera

orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 February 2022 in Biomolecules
Verified
Journal Article
Open access
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FAFatma Acheuk
Fatma Acheuk
SBShereen Basiouni
Shereen Basiouni
Awad A ShehataAwad A Shehata
Awad A Shehata
KDKatie Dick
Katie Dick
HHHaifa Hajri
Haifa Hajri
Spyridon NtougiasSpyridon Ntougias
Spyridon Ntougias
Concerning human and environmental health, safe alternatives to synthetic pesticides are urgently needed. Many of the currently used synthetic pesticides are not authorized for application in organic agriculture. In addition, the developed resistances of various pests against classical pesticides necessitate the urgent demand for efficient and safe products with novel modes of action. Botanical pesticides are assumed to be effective against various crop pests, and they are easily biodegradable and available in high quantities and at a reasonable cost. Many of them may act by diverse yet unexplored mechanisms of action. It is therefore surprising that only few plant species have been developed for commercial usage as biopesticides. This article reviews the status of botanical pesticides, especially in Europe and Mediterranean countries, deepening their active principles and mechanisms of action. Moreover, some constraints and challenges in the development of novel biopesticides are highlighted.

27 January 2022 in Microorganisms
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Journal Article
Open access
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Elias AsimakisElias Asimakis
Elias Asimakis
Awad A ShehataAwad A Shehata
Awad A Shehata
Wolfgang EisenreichWolfgang Eisenreich
Wolfgang Eisenreich
FAFatma Acheuk
Fatma Acheuk
SLSalma Lasram
Salma Lasram
Georgios TsiamisGeorgios Tsiamis
Georgios Tsiamis
An increasing human population necessitates more food production, yet current techniques in agriculture, such as chemical pesticide use, have negative impacts on the ecosystems and strong public opposition. Alternatives to synthetic pesticides should be safe for humans, the environment, and be sustainable. Extremely diverse ecological niches and millions of years of competition have shaped the genomes of algae to produce a myriad of substances that may serve humans in various biotechnological areas. Among the thousands of described algal species, only a small number have been investigated for valuable metabolites, yet these revealed the potential of algal metabolites as bio-pesticides. This review focuses on macroalgae and microalgae (including cyanobacteria) and their extracts or purified compounds, that have proven to be effective antibacterial, antiviral, antifungal, nematocides, insecticides, herbicides, and plant growth stimulants. Moreover, the mechanisms of action of the majority of these metabolites against plant pests are thoroughly discussed. The available information demonstrated herbicidal activities via inhibition of photosynthesis, antimicrobial activities via induction of plant defense responses, inhibition of quorum sensing and blocking virus entry, and insecticidal activities via neurotoxicity. The discovery of antimetabolites also seems to hold great potential as one recent example showed antimicrobial and herbicidal properties. Algae, especially microalgae, represent a vast untapped resource for discovering novel and safe biopesticide compounds.

14 January 2023 in Veterinary Sciences
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Journal Article
Open access
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SBShereen Basiouni
Shereen Basiouni
Guillermo TellezGuillermo Tellez
Guillermo Tellez
JLJuan Latorre
Juan Latorre
DGDanielle Graham
Danielle Graham
Victor Manuel Petrone-GarciaVictor Manuel Petrone-Garcia
Victor Manuel Petrone-Garcia
Awad A ShehataAwad A Shehata
Awad A Shehata
Chronic stress is recognized as a secret killer in poultry. It is associated with systemic inflammation due to cytokine release, dysbiosis, and the so-called leaky gut syndrome, which mainly results from oxidative stress reactions that damage the barrier function of the cells lining the gut wall. Poultry, especially the genetically selected broiler breeds, frequently suffer from these chronic stress symptoms when exposed to multiple stressors in their growing environments. Since oxidative stress reactions and inflammatory damages are multi-stage and long-term processes, overshooting immune reactions and their down-stream effects also negatively affect the animal’s microbiota, and finally impair its performance and commercial value. Means to counteract oxidative stress in poultry and other animals are, therefore, highly welcome. Many phytogenic substances, including flavonoids and phenolic compounds, are known to exert anti-inflammatory and antioxidant effects. In this review, firstly, the main stressors in poultry, such as heat stress, mycotoxins, dysbiosis and diets that contain oxidized lipids that trigger oxidative stress and inflammation, are discussed, along with the key transcription factors involved in the related signal transduction pathways. Secondly, the most promising phytogenic substances and their current applications to ameliorate oxidative stress and inflammation in poultry are highlighted.

16 November 2018 in Cellular and Molecular Life Sciences
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SPSarita Rani Patnaik
Sarita Rani Patnaik
VKViola Kretschmer
Viola Kretschmer
LBLena Brücker
Lena Brücker
SSSandra Schneider
Sandra Schneider
AVAnn-Kathrin Volz
Ann-Kathrin Volz
HMHelen May-Simera
Helen May-Simera

7 March 2022 in EMBO Molecular Medicine
Verified
Journal Article
Open access
SGSophia Grotz
Sophia Grotz
JSJessica Schäfer
Jessica Schäfer
KWKirsten A Wunderlich
Kirsten A Wunderlich
ZEZdenka Ellederova
Zdenka Ellederova
HAHannah Auch
Hannah Auch
NKNikolai Klymiuk
Nikolai Klymiuk
Usher syndrome (USH) is the most common form of monogenic deaf‐blindness. Loss of vision is untreatable and there are no suitable animal models for testing therapeutic strategies of the ocular constituent of USH, so far. By introducing a human mutation into the harmonin‐encoding USH1C gene in pigs, we generated the first translational animal model for USH type 1 with characteristic hearing defect, vestibular dysfunction, and visual impairment. Changes in photoreceptor architecture, quantitative motion analysis, and electroretinography were characteristics of the reduced retinal virtue in USH1C pigs. Fibroblasts from USH1C pigs or USH1C patients showed significantly elongated primary cilia, confirming USH as a true and general ciliopathy. Primary cells also proved their capacity for assessing the therapeutic potential of CRISPR/Cas‐mediated gene repair or gene therapy in vitro . AAV‐based delivery of harmonin into the eye of USH1C pigs indicated therapeutic efficacy in vivo .

27 September 2021 in Nature Communications
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Journal Article
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AVAnn-Kathrin Volz
Ann-Kathrin Volz
AFAlina Frei
Alina Frei
VKViola Kretschmer
Viola Kretschmer
ADAntónio Miguel De Jesus Domingues
António Miguel De Jesus Domingues
RKRené Ketting
René Ketting
HMHelen May-Simera
Helen May-Simera
Primary cilia are microtubule based sensory organelles important for receiving and processing cellular signals. Recent studies have shown that cilia also release extracellular vesicles (EVs). Because EVs have been shown to exert various physiological functions, these findings have the potential to alter our understanding of how primary cilia regulate specific signalling pathways. So far the focus has been on lgEVs budding directly from the ciliary membrane. An association between cilia and MVB-derived smEVs has not yet been described. We show that ciliary mutant mammalian cells demonstrate increased secretion of small EVs (smEVs) and a change in EV composition. Characterisation of smEV cargo identified signalling molecules that are differentially loaded upon ciliary dysfunction. Furthermore, we show that these smEVs are biologically active and modulate the WNT response in recipient cells. These results provide us with insights into smEV-dependent ciliary signalling mechanisms which might underly ciliopathy disease pathogenesis.