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1.
Nat Immunol ; 23(9): 1365-1378, 2022 09.
Article in English | MEDLINE | ID: mdl-35999394

ABSTRACT

CD28 and CTLA-4 (CD152) play essential roles in regulating T cell immunity, balancing the activation and inhibition of T cell responses, respectively. Although both receptors share the same ligands, CD80 and CD86, the specific requirement for two distinct ligands remains obscure. In the present study, we demonstrate that, although CTLA-4 targets both CD80 and CD86 for destruction via transendocytosis, this process results in separate fates for CTLA-4 itself. In the presence of CD80, CTLA-4 remained ligand bound, and was ubiquitylated and trafficked via late endosomes and lysosomes. In contrast, in the presence of CD86, CTLA-4 detached in a pH-dependent manner and recycled back to the cell surface to permit further transendocytosis. Furthermore, we identified clinically relevant mutations that cause autoimmune disease, which selectively disrupted CD86 transendocytosis, by affecting either CTLA-4 recycling or CD86 binding. These observations provide a rationale for two distinct ligands and show that defects in CTLA-4-mediated transendocytosis of CD86 are associated with autoimmunity.


Subject(s)
Antigens, CD , CD28 Antigens , Antigens, CD/metabolism , Antigens, Differentiation/metabolism , B7-1 Antigen , B7-2 Antigen/genetics , CD28 Antigens/metabolism , CTLA-4 Antigen/genetics , Cell Adhesion Molecules , Ligands , Lymphocyte Activation
2.
Annu Rev Genet ; 57: 361-390, 2023 11 27.
Article in English | MEDLINE | ID: mdl-37722684

ABSTRACT

Genetic biocontrol aims to suppress or modify populations of species to protect public health, agriculture, and biodiversity. Advancements in genome engineering technologies have fueled a surge in research in this field, with one gene editing technology, CRISPR, leading the charge. This review focuses on the current state of CRISPR technologies for genetic biocontrol of pests and highlights the progress and ongoing challenges of using these approaches.


Subject(s)
CRISPR-Cas Systems , Clustered Regularly Interspaced Short Palindromic Repeats , CRISPR-Cas Systems/genetics , Clustered Regularly Interspaced Short Palindromic Repeats/genetics , Gene Editing , Genome
3.
Mol Cell ; 80(2): 246-262.e4, 2020 10 15.
Article in English | MEDLINE | ID: mdl-32949493

ABSTRACT

CRISPR-Cas9-based gene drive systems possess the inherent capacity to spread progressively throughout target populations. Here we describe two self-copying (or active) guide RNA-only genetic elements, called e-CHACRs and ERACRs. These elements use Cas9 produced in trans by a gene drive either to inactivate the cas9 transgene (e-CHACRs) or to delete and replace the gene drive (ERACRs). e-CHACRs can be inserted at various genomic locations and carry two or more gRNAs, the first copying the e-CHACR and the second mutating and inactivating the cas9 transgene. Alternatively, ERACRs are inserted at the same genomic location as a gene drive, carrying two gRNAs that cut on either side of the gene drive to excise it. e-CHACRs efficiently inactivate Cas9 and can drive to completion in cage experiments. Similarly, ERACRs, particularly those carrying a recoded cDNA-restoring endogenous gene activity, can drive reliably to fully replace a gene drive. We compare the strengths of these two systems.


Subject(s)
Gene Deletion , Gene Drive Technology , Animals , CRISPR-Associated Protein 9/metabolism , Chromosomes/genetics , Drosophila melanogaster/genetics , Female , Green Fluorescent Proteins/metabolism , Inheritance Patterns/genetics , Mutagenesis/genetics , RNA, Guide, Kinetoplastida/genetics , Transgenes
4.
Proc Natl Acad Sci U S A ; 121(27): e2312456121, 2024 Jul 02.
Article in English | MEDLINE | ID: mdl-38917000

ABSTRACT

Controlling the principal African malaria vector, the mosquito Anopheles gambiae, is considered essential to curtail malaria transmission. However, existing vector control technologies rely on insecticides, which are becoming increasingly ineffective. Sterile insect technique (SIT) is a powerful suppression approach that has successfully eradicated a number of insect pests, yet the A. gambiae toolkit lacks the requisite technologies for its implementation. SIT relies on iterative mass releases of nonbiting, nondriving, sterile males which seek out and mate with monandrous wild females. Once mated, females are permanently sterilized due to mating-induced refractoriness, which results in population suppression of the subsequent generation. However, sterilization by traditional methods renders males unfit, making the creation of precise genetic sterilization methods imperative. Here, we introduce a vector control technology termed precision-guided sterile insect technique (pgSIT), in A. gambiae for inducible, programmed male sterilization and female elimination for wide-scale use in SIT campaigns. Using a binary CRISPR strategy, we cross separate engineered Cas9 and gRNA strains to disrupt male-fertility and female-essential genes, yielding >99.5% male sterility and >99.9% female lethality in hybrid progeny. We demonstrate that these genetically sterilized males have good longevity, are able to induce sustained population suppression in cage trials, and are predicted to eliminate wild A. gambiae populations using mathematical models, making them ideal candidates for release. This work provides a valuable addition to the malaria genetic biocontrol toolkit, enabling scalable SIT-like confinable, species-specific, and safe suppression in the species.


Subject(s)
Anopheles , Malaria , Mosquito Control , Mosquito Vectors , Animals , Male , Anopheles/genetics , Anopheles/physiology , Mosquito Vectors/genetics , Mosquito Vectors/parasitology , Malaria/transmission , Malaria/prevention & control , Female , Mosquito Control/methods , Infertility, Male/genetics , CRISPR-Cas Systems
5.
Trends Genet ; 39(2): 154-166, 2023 02.
Article in English | MEDLINE | ID: mdl-36414481

ABSTRACT

Gene-editing technologies have revolutionized the field of mosquito sensory biology. These technologies have been used to knock in reporter genes in-frame with neuronal genes and tag specific mosquito neurons to detect their activities using binary expression systems. Despite these advances, novel tools still need to be developed to elucidate the transmission of olfactory signals from the periphery to the brain. Here, we propose the development of a set of tools, including novel driver lines as well as sensors of neuromodulatory activities, which can advance our knowledge of how sensory input triggers behavioral outputs. This information can change our understanding of mosquito neurobiology and lead to the development of strategies for mosquito behavioral manipulation to reduce bites and disease transmission.


Subject(s)
Culicidae , Animals , Culicidae/genetics , Smell/genetics , Gene Editing , Neurons
6.
Nucleic Acids Res ; 52(D1): D808-D816, 2024 Jan 05.
Article in English | MEDLINE | ID: mdl-37953350

ABSTRACT

The Eukaryotic Pathogen, Vector and Host Informatics Resource (VEuPathDB, https://veupathdb.org) is a Bioinformatics Resource Center funded by the National Institutes of Health with additional funding from the Wellcome Trust. VEuPathDB supports >600 organisms that comprise invertebrate vectors, eukaryotic pathogens (protists and fungi) and relevant free-living or non-pathogenic species or hosts. Since 2004, VEuPathDB has analyzed omics data from the public domain using contemporary bioinformatic workflows, including orthology predictions via OrthoMCL, and integrated the analysis results with analysis tools, visualizations, and advanced search capabilities. The unique data mining platform coupled with >3000 pre-analyzed data sets facilitates the exploration of pertinent omics data in support of hypothesis driven research. Comparisons are easily made across data sets, data types and organisms. A Galaxy workspace offers the opportunity for the analysis of private large-scale datasets and for porting to VEuPathDB for comparisons with integrated data. The MapVEu tool provides a platform for exploration of spatially resolved data such as vector surveillance and insecticide resistance monitoring. To address the growing body of omics data and advances in laboratory techniques, VEuPathDB has added several new data types, searches and features, improved the Galaxy workspace environment, redesigned the MapVEu interface and updated the infrastructure to accommodate these changes.


Subject(s)
Computational Biology , Eukaryota , Animals , Computational Biology/methods , Invertebrates , Databases, Factual
7.
PLoS Genet ; 19(11): e1011065, 2023 Nov.
Article in English | MEDLINE | ID: mdl-38011259

ABSTRACT

Only female mosquitoes consume blood giving them the opportunity to transmit deadly human pathogens. Therefore, it is critical to remove females before conducting releases for genetic biocontrol interventions. Here we describe a robust sex-sorting approach termed SEPARATOR (Sexing Element Produced by Alternative RNA-splicing of A Transgenic Observable Reporter) that exploits sex-specific alternative splicing of an innocuous reporter to ensure exclusive dominant male-specific expression. Using SEPARATOR, we demonstrate reliable sex selection from early larval and pupal stages in Aedes aegypti, and use a Complex Object Parametric Analyzer and Sorter (COPAS) to demonstrate scalable high-throughput sex-selection of first instar larvae. Additionally, we use this approach to sequence the transcriptomes of early larval males and females and find several genes that are sex-specifically expressed. SEPARATOR can simplify mass production of males for release programs and is designed to be cross-species portable and should be instrumental for genetic biocontrol interventions.


Subject(s)
Aedes , Alternative Splicing , Animals , Male , Female , Humans , Alternative Splicing/genetics , Aedes/genetics , Animals, Genetically Modified , Larva/genetics
8.
PLoS Pathog ; 19(1): e1010842, 2023 01.
Article in English | MEDLINE | ID: mdl-36656895

ABSTRACT

As a major insect vector of multiple arboviruses, Aedes aegypti poses a significant global health and economic burden. A number of genetic engineering tools have been exploited to understand its biology with the goal of reducing its impact. For example, current tools have focused on knocking-down RNA transcripts, inducing loss-of-function mutations, or expressing exogenous DNA. However, methods for transactivating endogenous genes have not been developed. To fill this void, here we developed a CRISPR activation (CRISPRa) system in Ae. aegypti to transactivate target gene expression. Gene expression is activated through pairing a catalytically-inactive ('dead') Cas9 (dCas9) with a highly-active tripartite activator, VP64-p65-Rta (VPR) and synthetic guide RNA (sgRNA) complementary to a user defined target-gene promoter region. As a proof of concept, we demonstrate that engineered Ae. aegypti mosquitoes harboring a binary CRISPRa system can be used to effectively overexpress two developmental genes, even-skipped (eve) and hedgehog (hh), resulting in observable morphological phenotypes. We also used this system to overexpress the positive transcriptional regulator of the Toll immune pathway known as AaRel1, which resulted in a significant suppression of dengue virus serotype 2 (DENV2) titers in the mosquito. This system provides a versatile tool for research pathways not previously possible in Ae. aegypti, such as programmed overexpression of endogenous genes, and may aid in gene characterization studies and the development of innovative vector control tools.


Subject(s)
Aedes , Animals , Humans , Hedgehog Proteins/metabolism , Mosquito Vectors/genetics , RNA/metabolism , Transcriptional Activation , CRISPR-Cas Systems
9.
Genome Res ; 31(3): 512-528, 2021 03.
Article in English | MEDLINE | ID: mdl-33419731

ABSTRACT

Although mosquitoes are major transmission vectors for pathogenic arboviruses, viral infection has little impact on mosquito health. This immunity is caused in part by mosquito RNA interference (RNAi) pathways that generate antiviral small interfering RNAs (siRNAs) and Piwi-interacting RNAs (piRNAs). RNAi also maintains genome integrity by potently repressing mosquito transposon activity in the germline and soma. However, viral and transposon small RNA regulatory pathways have not been systematically examined together in mosquitoes. Therefore, we developed an integrated mosquito small RNA genomics (MSRG) resource that analyzes the transposon and virus small RNA profiles in mosquito cell cultures and somatic and gonadal tissues across four medically important mosquito species. Our resource captures both somatic and gonadal small RNA expression profiles within mosquito cell cultures, and we report the evolutionary dynamics of a novel Mosquito-Conserved piRNA Cluster Locus (MCpiRCL) made up of satellite DNA repeats. In the larger culicine mosquito genomes we detected highly regular periodicity in piRNA biogenesis patterns coinciding with the expansion of Piwi pathway genes. Finally, our resource enables detection of cross talk between piRNA and siRNA populations in mosquito cells during a response to virus infection. The MSRG resource will aid efforts to dissect and combat the capacity of mosquitoes to tolerate and spread arboviruses.


Subject(s)
Culicidae/genetics , Culicidae/virology , DNA Transposable Elements/genetics , Genomics , RNA, Small Interfering/genetics , Viruses , Animals
10.
Cancer Causes Control ; 35(4): 605-609, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37975972

ABSTRACT

BACKGROUND: Head and neck cancer (HNC) has low 5-year survival, and evidence-based recommendations for tertiary prevention are lacking. Aspirin improves outcomes for cancers at other sites, but its role in HNC tertiary prevention remains understudied. METHODS: HNC patients were recruited in the University of Michigan Head and Neck Cancer Specialized Program of Research Excellence (SPORE) from 2003 to 2014. Aspirin data were collected through medical record review; outcomes (overall mortality, HNC-specific mortality, and recurrence) were collected through medical record review, Social Security Death Index, or LexisNexis. Cox proportional hazards models were used to evaluate the associations between aspirin use at diagnosis (yes/no) and HNC outcomes. RESULTS: We observed no statistically significant associations between aspirin and cancer outcome in our HNC patient cohort (n = 1161) (HNC-specific mortality: HR = 0.91, 95% CI = 0.68-1.21; recurrence: HR = 0.94, 95% CI = 0.73-1.19). In analyses stratified by anatomic site, HPV status, and disease stage, we observed no association in any strata examined with the possible exception of a lower risk of recurrence in oropharynx patients (HR = 0.60, 95% CI 0.35-1.04). CONCLUSIONS: Our findings do not support a protective association between aspirin use and cancer-specific death or recurrence in HNC patients, with the possible exception of a lower risk of recurrence in oropharynx patients.


Subject(s)
Aspirin , Head and Neck Neoplasms , Humans , Aspirin/therapeutic use , Head and Neck Neoplasms/drug therapy , Proportional Hazards Models
11.
Cytokine ; 179: 156629, 2024 07.
Article in English | MEDLINE | ID: mdl-38704961

ABSTRACT

Melanoma is a particularly aggressive type of skin cancer that can spread to distant organs, resulting in poor patient outcomes. C-X-C motif chemokine ligand 12 (CXCL12) interacts to the C-X-C chemokine receptor type 4 (CXCR4). This connection between CXCR4 and its companion ligand CXCL12 is important in melanoma metastasis and progression, encouraging cell proliferation, invasion, and survival via downstream signaling pathways. Furthermore, CXCR4 is implicated in the interaction between melanoma cells and the tumor microenvironment, which promotes malignant cell migration and immune evasion. Given the importance of the CXCR4/CXCL12 axis in melanoma, addressing this axis has the potential to prevent metastasis and improve patient outcomes. We present an overview of the CXCR4/CXCL12 axis in cancer progression and explain its role in the melanoma microenvironment in this paper. Furthermore, we investigate CXCR4's predictive usefulness as a possible biomarker for monitoring melanoma progression. Finally, we discuss the most recent research and clinical trials on CXCR4 inhibitors, emphasizing their efficacy and limits. We hope to improve the quality of life for melanoma patients by better understanding the role of CXCR4 and investigating novel therapeutic options.


Subject(s)
Chemokine CXCL12 , Melanoma , Receptors, CXCR4 , Signal Transduction , Tumor Microenvironment , Humans , Receptors, CXCR4/metabolism , Melanoma/metabolism , Melanoma/pathology , Chemokine CXCL12/metabolism , Skin Neoplasms/pathology , Skin Neoplasms/metabolism , Animals , Disease Progression
12.
Insect Mol Biol ; 33(4): 362-371, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38450861

ABSTRACT

Multiple Wolbachia strains can block pathogen infection, replication and/or transmission in Aedes aegypti mosquitoes under both laboratory and field conditions. However, Wolbachia effects on pathogens can be highly variable across systems and the factors governing this variability are not well understood. It is increasingly clear that the mosquito host is not a passive player in which Wolbachia governs pathogen transmission phenotypes; rather, the genetics of the host can significantly modulate Wolbachia-mediated pathogen blocking. Specifically, previous work linked variation in Wolbachia pathogen blocking to polymorphisms in the mosquito alpha-mannosidase-2 (αMan2) gene. Here we use CRISPR-Cas9 mutagenesis to functionally test this association. We developed αMan2 knockouts and examined effects on both Wolbachia and virus levels, using dengue virus (DENV; Flaviviridae) and Mayaro virus (MAYV; Togaviridae). Wolbachia titres were significantly elevated in αMan2 knockout (KO) mosquitoes, but there were complex interactions with virus infection and replication. In Wolbachia-uninfected mosquitoes, the αMan2 KO mutation was associated with decreased DENV titres, but in a Wolbachia-infected background, the αMan2 KO mutation significantly increased virus titres. In contrast, the αMan2 KO mutation significantly increased MAYV replication in Wolbachia-uninfected mosquitoes and did not affect Wolbachia-mediated virus blocking. These results demonstrate that αMan2 modulates arbovirus infection in A. aegypti mosquitoes in a pathogen- and Wolbachia-specific manner, and that Wolbachia-mediated pathogen blocking is a complex phenotype dependent on the mosquito host genotype and the pathogen. These results have a significant impact for the design and use of Wolbachia-based strategies to control vector-borne pathogens.


Subject(s)
Aedes , Wolbachia , alpha-Mannosidase , Animals , Aedes/microbiology , Aedes/virology , Aedes/genetics , Wolbachia/physiology , alpha-Mannosidase/metabolism , alpha-Mannosidase/genetics , Dengue Virus/physiology , Arboviruses/physiology , Mosquito Vectors/microbiology , Mosquito Vectors/virology , Mosquito Vectors/genetics , Female , Arbovirus Infections/transmission , Insect Proteins/metabolism , Insect Proteins/genetics , CRISPR-Cas Systems
13.
Nature ; 563(7732): 501-507, 2018 11.
Article in English | MEDLINE | ID: mdl-30429615

ABSTRACT

Female Aedes aegypti mosquitoes infect more than 400 million people each year with dangerous viral pathogens including dengue, yellow fever, Zika and chikungunya. Progress in understanding the biology of mosquitoes and developing the tools to fight them has been slowed by the lack of a high-quality genome assembly. Here we combine diverse technologies to produce the markedly improved, fully re-annotated AaegL5 genome assembly, and demonstrate how it accelerates mosquito science. We anchored physical and cytogenetic maps, doubled the number of known chemosensory ionotropic receptors that guide mosquitoes to human hosts and egg-laying sites, provided further insight into the size and composition of the sex-determining M locus, and revealed copy-number variation among glutathione S-transferase genes that are important for insecticide resistance. Using high-resolution quantitative trait locus and population genomic analyses, we mapped new candidates for dengue vector competence and insecticide resistance. AaegL5 will catalyse new biological insights and intervention strategies to fight this deadly disease vector.


Subject(s)
Aedes/genetics , Arbovirus Infections/virology , Arboviruses , Genome, Insect/genetics , Genomics/standards , Insect Control , Mosquito Vectors/genetics , Mosquito Vectors/virology , Aedes/virology , Animals , Arbovirus Infections/transmission , Arboviruses/isolation & purification , DNA Copy Number Variations/genetics , Dengue Virus/isolation & purification , Female , Genetic Variation/genetics , Genetics, Population , Glutathione Transferase/genetics , Insecticide Resistance/drug effects , Male , Molecular Sequence Annotation , Multigene Family/genetics , Pyrethrins/pharmacology , Reference Standards , Sex Determination Processes/genetics
14.
BMC Vet Res ; 20(1): 90, 2024 Mar 08.
Article in English | MEDLINE | ID: mdl-38459498

ABSTRACT

BACKGROUND: Multiple sclerosis (MS) is a chronic condition that primarily manifests as demyelination of neuronal axons in the central nervous system, due to the loss or attack of oligodendroglia cells that form myelin. Stem cell therapy has shown promising results for the treatment of MS due to its capability to halt the immune attack, stop apoptosis and axonal degeneration, and differentiate into oligodendrocytes. Stem cell-derived Exosomes (Exosomes) have shown great capabilities for neuronal diseases as they have growth factors, complex sets of miRNA, enzymes, proteins, major peptides, lipids, and macromolecules with anti-inflammatory, angiogenesis, and neurogenesis activities. METHODS: This study aimed to compare the healing properties of stem cells, against Exosomes for the treatment of an experimentally induced MS dog model. Dog models of MS received either a single treatment of stem cells or a single treatment of Exosomes intrathecally and the treatment process was evaluated clinically, radiologically, histopathologically, and electron microscopy and cerebrospinal fluid analysis. RESULTS: showed marked amelioration of the clinical signs in both treated groups compared to the control one, magnetic resonance scans showed the resolution of the hyperintense lesions at the end of the study period, the histopathology and electron microscopy showed marked healing properties and remyelination in treated groups with superiority of the stem cells compared to Exosomes. CONCLUSIONS: Although stem cell results were superior to Exosomes therapy; Exosomes have proven to be effective and safe important actors in myelin regeneration, and their use in diseases like MS helps to stimulate remyelination.


Subject(s)
Dog Diseases , Exosomes , Multiple Sclerosis , Dogs , Animals , Multiple Sclerosis/veterinary , Multiple Sclerosis/drug therapy , Myelin Sheath/metabolism , Myelin Sheath/pathology , Stem Cells , Cell- and Tissue-Based Therapy/veterinary , Dog Diseases/pathology
15.
Nucleic Acids Res ; 50(D1): D898-D911, 2022 01 07.
Article in English | MEDLINE | ID: mdl-34718728

ABSTRACT

The Eukaryotic Pathogen, Vector and Host Informatics Resource (VEuPathDB, https://veupathdb.org) represents the 2019 merger of VectorBase with the EuPathDB projects. As a Bioinformatics Resource Center funded by the National Institutes of Health, with additional support from the Welllcome Trust, VEuPathDB supports >500 organisms comprising invertebrate vectors, eukaryotic pathogens (protists and fungi) and relevant free-living or non-pathogenic species or hosts. Designed to empower researchers with access to Omics data and bioinformatic analyses, VEuPathDB projects integrate >1700 pre-analysed datasets (and associated metadata) with advanced search capabilities, visualizations, and analysis tools in a graphic interface. Diverse data types are analysed with standardized workflows including an in-house OrthoMCL algorithm for predicting orthology. Comparisons are easily made across datasets, data types and organisms in this unique data mining platform. A new site-wide search facilitates access for both experienced and novice users. Upgraded infrastructure and workflows support numerous updates to the web interface, tools, searches and strategies, and Galaxy workspace where users can privately analyse their own data. Forthcoming upgrades include cloud-ready application architecture, expanded support for the Galaxy workspace, tools for interrogating host-pathogen interactions, and improved interactions with affiliated databases (ClinEpiDB, MicrobiomeDB) and other scientific resources, and increased interoperability with the Bacterial & Viral BRC.


Subject(s)
Databases, Factual , Disease Vectors/classification , Host-Pathogen Interactions/genetics , Phenotype , User-Computer Interface , Animals , Apicomplexa/classification , Apicomplexa/genetics , Apicomplexa/pathogenicity , Bacteria/classification , Bacteria/genetics , Bacteria/pathogenicity , Communicable Diseases/microbiology , Communicable Diseases/parasitology , Communicable Diseases/pathology , Communicable Diseases/transmission , Computational Biology/methods , Data Mining/methods , Diplomonadida/classification , Diplomonadida/genetics , Diplomonadida/pathogenicity , Fungi/classification , Fungi/genetics , Fungi/pathogenicity , Humans , Insecta/classification , Insecta/genetics , Insecta/pathogenicity , Internet , Nematoda/classification , Nematoda/genetics , Nematoda/pathogenicity , Phylogeny , Virulence , Workflow
16.
Proc Natl Acad Sci U S A ; 118(22)2021 06 01.
Article in English | MEDLINE | ID: mdl-34031258

ABSTRACT

Aedes aegypti spread devastating viruses such as dengue, which causes disease among 100 to 400 million people annually. A potential approach to control mosquito disease vectors is the sterile insect technique (SIT). The strategy involves repeated release of large numbers of sterile males, which reduces insect populations because the sterile males mate and thereby suppress the fertility of females that would otherwise mate with fertile males. While SIT has been successful in suppressing certain agricultural pests, it has been less effective in depressing populations of Ae. aegypti This limitation is in part because of the fitness effects resulting from mutagenizing the mosquitoes nonspecifically. Here, we introduced and characterized the impact on female fertility of an Ae. aegypti mutation that disrupts a gene that is specifically expressed in testes. We used CRISPR/Cas9 to generate a null mutation in the Ae. aegypti ß2-tubulin (B2t) gene, which eliminates male fertility. When we allowed wild-type females to first mate with B2t mutant males, most of the females did not produce progeny even after being subsequently exposed to wild-type males. We also introduced B2t mutant and wild-type males simultaneously with wild-type females and found that a larger number of B2t mutant males relative to the wild-type males was effective in significantly suppressing female fertility. These results raise the possibility of employing B2t sterile males to improve the efficacy of SIT in suppressing populations of Ae. aegypti through repeated releases and thereby reduce the transmission of viruses by these invasive mosquitoes.


Subject(s)
Aedes/genetics , Infertility, Male/genetics , Pest Control, Biological , Animals , CRISPR-Cas Systems , Female , Gene Editing , Infertility, Female , Male
17.
Article in English | MEDLINE | ID: mdl-38512495

ABSTRACT

In the current study, the bottlebrush [Callistemon viminalis (Sol. ex Gaertn.) G. Don] plant was selected for the green synthesis of silver (Ag) and gold (Au) nanoparticles and to evaluate its antibacterial and antifungal activities. Phytochemical screening of C. viminalis confirmed the presence of alkaloids, anthraquinones, saponins, tannins, betacyanins, phlobatanins, coumarins, terpenoids, steroids, glycosides, and proteins. To characterize the synthesized Ag and Au NPs, UV-Visible spectroscopy, FTIR spectroscopy for functional group identification, field emission scanning electron microscopy (FE-SEM) for particle size, and elemental analysis were performed using EDX. The UV-Visible absorption spectra of the green-synthesized Ag and Au nanoparticles were found to have a maximum absorption band at 420 nm for Ag NPs and 525 nm for Au NPs. FE-SEM analysis of the synthesized NPs revealed a circular shape with a size of 100 nm. Elemental analysis was performed for the synthesis of Ag and Au NPs, which confirmed the purity of the nanoparticles. The greenly synthesized Ag and Au NPs were also evaluated for their anti-bacterial and anti-fungal activities, which exhibited prominent inhibition activities against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, Candida albicans, C. krusei, Aspergillus sp., and Trichoderma species. The highest zone of inhibition 15.5 ± 0.75 and 15 ± 0.85 mm was observed for Ag NPs against E. coli and P. aeruginosa. Similarly, Trichoderma sp. and Aspergillus sp. were inhibited by Ag NPs up to 13.5 ± 0.95 and 13 ± 0.70 mm. This work will open doors for the development of new antimicrobial agents using green chemistry.

18.
Sensors (Basel) ; 24(2)2024 Jan 22.
Article in English | MEDLINE | ID: mdl-38276381

ABSTRACT

Time synchronization is vital for accurate data collection and processing in sensor networks. Sensors in these networks often operate under fluctuating conditions. However, an accurate timekeeping mechanism is critical even in varying network conditions. Consequently, a synchronization method is required in sensor networks to ensure reliable timekeeping for correlating data accurately across the network. In this research, we present a novel dynamic NTP (Network Time Protocol) algorithm that significantly enhances the precision and reliability of the generalized NTP protocol. It incorporates a dynamic mechanism to determine the Round-Trip Time (RTT), which allows accurate timekeeping even in varying network conditions. The proposed approach has been implemented on an FPGA and a comprehensive performance analysis has been made, comparing three distinct NTP methods: dynamic NTP (DNTP), static NTP (SNTP), and GPS-based NTP (GNTP). As a result, key performance metrics such as variance, standard deviation, mean, and median accuracy have been evaluated. Our findings demonstrate that DNTP is markedly superior in dynamic network scenarios, a common characteristic in sensor networks. This adaptability is important for sensors installed in time-critical networks, such as real-time industrial IoTs, where precise and reliable time synchronization is necessary.

19.
Drug Dev Ind Pharm ; 50(3): 274-283, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38374658

ABSTRACT

OBJECTIVE: Apigenin and gallic acid are natural compounds that are useful as antioxidant, anti-inflammatory and anticancer agents, especially when used together in combination. Therefore, the development and validation of a simultaneous method of analysis for both compounds in pure form and when encapsulated in an advanced delivery system such as liposomes would be useful. METHODS: Analysis was performed using C18 column under isocratic conditions. The mobile phase was acetonitrile: water containing 0.2% orthophosphoric acid at a ratio of 67:33, flow rate 1 ml/min, and detection wavelength 334 nm for apigenin and 271 nm for gallic acid. RESULTS: The assay method was linear at the concentration range (5-600 µg/mL) with R2 of 1 for both drugs. The method was also shown to be precise and robust with RSD less than 2% with LOD (0.12, 0.1 µg/mL) and LOQ (4.14, 3.58 µg/mL) for apigenin and gallic acid respectively. The method was also applicable for the determination of the entrapment efficiency of both drugs when co-loaded in a nanoliposomal formulation. CONCLUSION: The described HPLC method was shown to be suitable, sensitive, and reproducible for the simultaneous identification and quantification of apigenin and gallic acid. The analytical results were accurate and precise, with good recovery, low limit of detection, and the chromatographic assay was accomplished in less than 3 min, suggesting the suitability of the method for routine analysis of both drugs in pharmaceutical formulations.


Subject(s)
Apigenin , Gallic Acid , Pharmaceutical Preparations , Chromatography, High Pressure Liquid/methods
20.
Saudi Pharm J ; 32(2): 101936, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38261938

ABSTRACT

In this work, we investigated Diospyros kaki extract and an isolated compound for their potential as xanthine oxidase (XO) inhibitors, a target enzyme involved in inflammatory disorders. The prepared extract was subjected to column chromatography, and dinaphthodiospyrol S was isolated. Then XO inhibitory properties were assessed using a spectrophotometry microplate reader. DMSO was taken as a negative control, and allopurinol was used as a standard drug. The molecular docking study of the isolated compound to the XO active site was performed, followed by visualization and protein-ligand interaction. The defatted chloroform extract showed the highest inhibitory effect, followed by the chloroform extract and the isolated compound. The isolated compound exhibited significant inhibitory activity against XO with an IC50 value of 1.09 µM. Molecular docking studies showed that the compound strongly interacts with XO, forming hydrogen bond interactions with Arg149 and Cys113 and H-pi interactions with Cys116 and Leu147. The binding score of -7.678 kcal/mol further supported the potential of the isolated compound as an XO inhibitor. The quantum chemical procedures were used to study the electronic behavior of dinaphthodiospyrol S isolated from D. kaki. Frontier molecular orbital (FMO) analysis was performed to understand the distribution of electronic density, highest occupied molecular orbital HOMO, lowest unoccupied molecular orbital LUMO, and energy gaps. The values of HOMO, LUMO, and energy gap were found to be -6.39, -3.51 and 2.88 eV respectively. The FMO results indicated the intramolecular charge transfer. Moreover, reactivity descriptors were also determined to confirm the stability of the compound. The molecular electrostatic potential (MEP) investigation was done to analyze the electrophilic and nucleophilic sites within a molecule. The oxygen atoms in the compound exhibited negative potential, indicating that they are favorable sites for electrophilic attacks. The results indicate its potential as a therapeutic agent for related disorders. Further studies are needed to investigate this compound's in vivo efficacy and safety as a potential drug candidate.

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