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1.
Commun Biol ; 7(1): 470, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38649441

RESUMO

Proposed mechanisms of zoonotic virus spillover often posit that wildlife transmission and amplification precede human outbreaks. Between 2006 and 2012, the palm Raphia farinifera, a rich source of dietary minerals for wildlife, was nearly extirpated from Budongo Forest, Uganda. Since then, chimpanzees, black-and-white colobus, and red duiker were observed feeding on bat guano, a behavior not previously observed. Here we show that guano consumption may be a response to dietary mineral scarcity and may expose wildlife to bat-borne viruses. Videos from 2017-2019 recorded 839 instances of guano consumption by the aforementioned species. Nutritional analysis of the guano revealed high concentrations of sodium, potassium, magnesium and phosphorus. Metagenomic analyses of the guano identified 27 eukaryotic viruses, including a novel betacoronavirus. Our findings illustrate how "upstream" drivers such as socioeconomics and resource extraction can initiate elaborate chains of causation, ultimately increasing virus spillover risk.

2.
Virology ; 591: 109992, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38246037

RESUMO

We investigated the virome of agaonid fig wasps (Ceratosolen spp.) inside syconia ("fruits") of various Ficus trees fed upon by frugivores such as pteropodid bats in Sub-Saharan Africa. This virome includes representatives of viral families spanning four realms and includes near-complete genome sequences of three novel viruses and fragments of five additional potentially novel viruses evolutionarily associated with insects, fungi, plants, and vertebrates. Our study provides evidence that frugivorous animals are exposed to a plethora of viruses by coincidental consumption of fig wasps, which are obligate pollinators of figs worldwide.


Assuntos
Ficus , Vespas , Humanos , Animais , Viroma , Polinização , Frutas , Simbiose
3.
J Am Chem Soc ; 146(3): 1771-1775, 2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38181408

RESUMO

The search for a suitable replacement for the ubiquitous oxidizer ammonium perchlorate (AP) is a top priority to enable more sustainable solid rocket motors. The oxidizing salts ammonium nitrate (AN) and ammonium dinitramide (ADN) are regarded as potential green replacements for AP, but suffer from a plethora of handling and processing issues including poor stability and a needle-like crystal morphology which inhibits dense packing; these prevent their widespread use. In the present work, ionic cocrystallization is leveraged to produce the first cocrystals of these oxidizing salts with an energetic coformer and the first such cocrystals to maintain a positive oxygen balance. The azole-based energetic molecule 5,5'-dinitro-2H,2H'-3,3″-bi-1,2,4-triazole (DNBT) is successfully cocrystallized with AN to yield the cocrystal 2AN:DNBT. Differential scanning calorimetry data confirms that AN, which in its pure form suffers from a problematic solid-state phase transition, is stabilized in the cocrystal. Application of this cocrystallization strategy to ADN produces 2ADN:DNBT, which has the highest oxygen balance of any organic cocrystal.

4.
Geroscience ; 46(2): 2033-2049, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37801203

RESUMO

Myostatin negatively regulates skeletal muscle growth and appears upregulated in human obesity and associated with insulin resistance. However, observations are confounded by ageing, and the mechanisms responsible are unknown. The aim of this study was to delineate between the effects of excess adiposity, insulin resistance and ageing on myostatin mRNA expression in human skeletal muscle and to investigate causative factors using in vitro models. An in vivo cross-sectional analysis of human skeletal muscle was undertaken to isolate effects of excess adiposity and ageing per se on myostatin expression. In vitro studies employed human primary myotubes to investigate the potential involvement of cross-talk between subcutaneous adipose tissue (SAT) and skeletal muscle, and lipid-induced insulin resistance. Skeletal muscle myostatin mRNA expression was greater in aged adults with excess adiposity than age-matched adults with normal adiposity (2.0-fold higher; P < 0.05) and occurred concurrently with altered expression of genes involved in the maintenance of muscle mass but did not differ between younger and aged adults with normal adiposity. Neither chronic exposure to obese SAT secretome nor acute elevation of fatty acid availability (which induced insulin resistance) replicated the obesity-mediated upregulation of myostatin mRNA expression in vitro. In conclusion, skeletal muscle myostatin mRNA expression is uniquely upregulated in aged adults with excess adiposity and insulin resistance but not by ageing alone. This does not appear to be mediated by the SAT secretome or by lipid-induced insulin resistance. Thus, factors intrinsic to skeletal muscle may be responsible for the obesity-mediated upregulation of myostatin, and future work to establish causality is required.


Assuntos
Resistência à Insulina , Idoso , Humanos , Pessoa de Meia-Idade , Adiposidade/genética , Envelhecimento/genética , Estudos Transversais , Resistência à Insulina/genética , Lipídeos , Músculo Esquelético/metabolismo , Miostatina/genética , Miostatina/metabolismo , Obesidade/genética , Obesidade/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
5.
Sci Rep ; 13(1): 16606, 2023 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-37789066

RESUMO

Polymeric immunoglobulin receptor (PIGR) has a major role in mucosal immunity as a transporter of polymeric immunoglobulin across the epithelial cells. The aim of this study was to determine the effect of PIGR on cellular behaviours and chemo-sensitivity of MCF7 and MDA-MB468 breast cancer cell lines. Basal levels of PIGR mRNA and protein expression in MCF7 and MDA-MB468 cells were evaluated by real time quantitative polymerase chain reaction and Western blotting, respectively. MCF7/PIGR and MDA-MB468/PIGR stable cell lines, overexpressing the PIGR gene, were generated using a lentiviral vector with tetracycline dependent induction of expression. Cell viability, cell proliferation and chemo-sensitivity of PIGR transfected cells were evaluated and compared with un-transfected cells to determine the effect of PIGR overexpression on cell phenotype. The levels of PIGR mRNA and protein expression were significantly higher in MDA-MB468 cells than in MCF7 cells (380-fold, p < 0.0001). However, the differential expression of PIGR in these two cell lines did not lead to significant differences in chemosensitivity. Viral overexpression of PIGR was also not found to change any of the parameters measured in either cell line. PIGR per se did not affect cellular behaviours and chemosensitivity of these breast cancer cell lines.


Assuntos
Neoplasias da Mama , Receptores de Imunoglobulina Polimérica , Humanos , Feminino , Receptores de Imunoglobulina Polimérica/genética , Receptores de Imunoglobulina Polimérica/metabolismo , Neoplasias da Mama/genética , Células Epiteliais/metabolismo , Linhagem Celular , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
6.
Chemistry ; 29(27): e202300076, 2023 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-36812052

RESUMO

In contrast to the mature predictive frameworks applied to neutral cocrystals, ionic cocrystals, those including an ion pair, are difficult to design. Furthermore, they are generally excluded categorically from studies which correlate specific molecular properties to cocrystal formation, leaving the prospective ionic cocrystal engineer with few clear avenues to success. Herein ammonium nitrate, an energetic oxidizing salt, is targeted for cocrystallization in a potential coformer group selected based on likely interactions with the nitrate ion as revealed in the Cambridge Structural Database; six novel ionic cocrystals were discovered. Molecular descriptors previously identified as being related to neutral cocrystal formation were examined across the screening group but showed no relationship with ionic cocrystal formation. High packing coefficient is shown to be a constant among the successful coformers in the set and is utilized to directly target two more successful coformers, bypassing the need for a large screening group.

7.
Sci Rep ; 12(1): 16842, 2022 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-36207349

RESUMO

High expression of polymeric immunoglobulin receptor (PIGR) in breast cancer is associated with increased 5-year survival rate. However, the factors influencing PIGR expression in breast cancer have not been elucidated. The aim of this study was to determine the role of macrophages and cytokines affecting expression of PIGR in two breast cancer cell lines. M1, M2 macrophage conditioned media (CM) and recombinant human cytokines were used to determine factors which increased PIGR expression in MCF7 (HTB-22) and MDA-MB468 (HTB-132) breast cancer cell lines. The level of PIGR expression in the cells and PIGR secretory component were evaluated by real-time quantitative polymerase chain reaction and Western blotting. M1 macrophage CM induced a dose-dependent increase in PIGR mRNA expression in MDA-MB468 cells, up to 20-fold. The level of PIGR expression in MCF7 cells was very low and not affected by M1 and M2 CM. Interferon gamma (IFN-γ) and interleukin (IL)-1ß also increased PIGR expression in MDA-MB468 and MCF7 cells. However, IL-1ß was demonstrated to increase in M1 macrophages, while IFN-γ was not. The role of IL-1ß secreted from M1 macrophages in increasing expression of PIGR was confirmed by IL-1 receptor blockade, indicating that IL-1ß was the major M1 macrophage-derived cytokine that enhanced PIGR expression. Elevated PIGR expression in breast cancer in vivo may reflect the polarization state of tumor-associated immune cells.


Assuntos
Neoplasias da Mama , Receptores de Imunoglobulina Polimérica , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Meios de Cultivo Condicionados/farmacologia , Citocinas/metabolismo , Feminino , Humanos , Interferon gama/metabolismo , Interleucina-1beta/metabolismo , Macrófagos/metabolismo , RNA Mensageiro/metabolismo , Receptores de Interleucina-1/metabolismo , Receptores de Imunoglobulina Polimérica/genética , Receptores de Imunoglobulina Polimérica/metabolismo , Salicilatos , Componente Secretório
8.
Viruses ; 14(9)2022 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-36146724

RESUMO

The global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has highlighted the disparity between developed and developing countries for infectious disease surveillance and the sequencing of pathogen genomes. The majority of SARS-CoV-2 sequences published are from Europe, North America, and Asia. Between April 2020 and January 2022, 795 SARS-CoV-2-positive nares swabs from individuals in the U.S. Navy installation Camp Lemonnier, Djibouti, were collected, sequenced, and analyzed. In this study, we described the results of genomic sequencing and analysis for 589 samples, the first published viral sequences for Djibouti, including 196 cases of vaccine breakthrough infections. This study contributes to the knowledge base of circulating SARS-CoV-2 lineages in the under-sampled country of Djibouti, where only 716 total genome sequences are available at time of publication. Our analysis resulted in the detection of circulating variants of concern, mutations of interest in lineages in which those mutations are not common, and emerging spike mutations.


Assuntos
COVID-19 , Vacinas , COVID-19/epidemiologia , COVID-19/prevenção & controle , Djibuti/epidemiologia , Genoma Viral , Humanos , Mutação , SARS-CoV-2/genética
9.
One Health Outlook ; 4(1): 5, 2022 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-35216623

RESUMO

BACKGROUND: Understanding how and why people interact with animals is important for the prevention and control of zoonoses. To date, studies have primarily focused on the most visible forms of human-animal contact (e.g., hunting and consumption), thereby blinding One Health researchers and practitioners to the broader range of human-animal interactions that can serve as cryptic sources of zoonotic diseases. Zootherapy, the use of animal products for traditional medicine and cultural practices, is widespread and can generate opportunities for human exposure to zoonoses. Existing research examining zootherapies omits details necessary to adequately assess potential zoonotic risks. METHODS: We used a mixed-methods approach, combining quantitative and qualitative data from questionnaires, key informant interviews, and field notes to examine the use of zootherapy in nine villages engaged in wildlife hunting, consumption, and trade in Cross River State, Nigeria. We analyzed medicinal and cultural practices involving animals from a zoonotic disease perspective, by including details of animal use that may generate pathways for zoonotic transmission. We also examined the sociodemographic, cultural, and environmental contexts of zootherapeutic practices that can further shape the nature and frequency of human-animal interactions. RESULTS: Within our study population, people reported using 44 different animal species for zootherapeutic practices, including taxonomic groups considered to be "high risk" for zoonoses and threatened with extinction. Variation in use of animal parts, preparation norms, and administration practices generated a highly diverse set of zootherapeutic practices (n = 292) and potential zoonotic exposure risks. Use of zootherapy was patterned by demographic and environmental contexts, with zootherapy more commonly practiced by hunting households (OR = 2.47, p < 0.01), and prescriptions that were gender and age specific (e.g., maternal and pediatric care) or highly seasonal (e.g., associated with annual festivals and seasonal illnesses). Specific practices were informed by species availability and theories of healing (i.e., "like cures like" and sympathetic healing and magic) that further shaped the nature of human-animal interactions via zootherapy. CONCLUSIONS: Epidemiological investigations of zoonoses and public health interventions that aim to reduce zoonotic exposures should explicitly consider zootherapy as a potential pathway for disease transmission and consider the sociocultural and environmental contexts of their use in health messaging and interventions.

10.
Liver Int ; 42(3): 507-521, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35048542

RESUMO

As the worldwide prevalence of chronic liver diseases is high and continuing to increase, there is an urgent need for treatment to prevent cirrhosis-related morbidity and mortality. Integrins are heterodimeric cell-surface proteins that are promising targets for therapeutic intervention. αv integrins are central in the development of fibrosis as they activate latent TGFß, a known profibrogenic cytokine. The αv subunit can form heterodimers with ß1, ß3, ß5, ß6 or ß8 subunits and one or more of these integrins are central to the development of liver fibrosis, however, their relative importance is not understood. This review summarises the current knowledge of αv integrins and their respective ß subunits in different organs, with a focus on liver fibrosis and the emerging preclinical and clinical data with regards to αv integrin inhibitors.


Assuntos
Integrinas , Preparações Farmacêuticas , Humanos , Integrina alfaV/metabolismo , Integrinas/metabolismo , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/metabolismo , Fator de Crescimento Transformador beta/metabolismo
12.
Arch Virol ; 166(12): 3513-3566, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34463877

RESUMO

In March 2021, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was amended and emended. The phylum was expanded by four families (Aliusviridae, Crepuscuviridae, Myriaviridae, and Natareviridae), three subfamilies (Alpharhabdovirinae, Betarhabdovirinae, and Gammarhabdovirinae), 42 genera, and 200 species. Thirty-nine species were renamed and/or moved and seven species were abolished. This article presents the updated taxonomy of Negarnaviricota as now accepted by the ICTV.


Assuntos
Mononegavirais , Vírus , Humanos
13.
Viruses ; 13(5)2021 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-34066683

RESUMO

Bat flies (Hippoboscoidea: Nycteribiidae and Streblidae) are obligate hematophagous ectoparasites of bats. We collected streblid bat flies from the New World (México) and the Old World (Uganda), and used metagenomics to identify their viruses. In México, we found méjal virus (Rhabdoviridae; Vesiculovirus), Amate virus (Reoviridae: Orbivirus), and two unclassified viruses of invertebrates. Méjal virus is related to emerging zoonotic encephalitis viruses and to the agriculturally important vesicular stomatitis viruses (VSV). Amate virus and its sister taxon from a bat are most closely related to mosquito- and tick-borne orbiviruses, suggesting a previously unrecognized orbivirus transmission cycle involving bats and bat flies. In Uganda, we found mamucuso virus (Peribunyaviridae: Orthobunyavirus) and two unclassified viruses (a rhabdovirus and an invertebrate virus). Mamucuso virus is related to encephalitic viruses of mammals and to viruses from nycteribiid bat flies and louse flies, suggesting a previously unrecognized orthobunyavirus transmission cycle involving hippoboscoid insects. Bat fly virus transmission may be neither strictly vector-borne nor strictly vertical, with opportunistic feeding by bat flies occasionally leading to zoonotic transmission. Many "bat-associated" viruses, which are ecologically and epidemiologically associated with bats but rarely or never found in bats themselves, may actually be viruses of bat flies or other bat ectoparasites.


Assuntos
Dípteros/virologia , Tropismo Viral , Animais , Código de Barras de DNA Taxonômico , Dípteros/classificação , Dípteros/genética , Geografia , Especificidade de Hospedeiro , Metagenômica/métodos , México , Filogenia , Uganda
14.
J Mater Chem B ; 9(20): 4120-4133, 2021 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-33982048

RESUMO

Effective regenerative medicine requires delivery systems which can release multiple components at appropriate levels and at different phases of tissue growth and repair. However, there are few biomaterials and encapsulation techniques that are fully suitable for the loading and controlled release of multiple proteins. In this study we describe how proteins were physically and chemically loaded into a single coaxial electrospun fibre scaffold to obtain bi-phasic release profiles. Cyto-compatible polymers were used to construct the scaffold, using polyethylene oxide (PEO) for the core and polycaprolactone (PCL) reacted or mixed with (bis-aminopropyl)polyether (Jeffamine ED2003; JFA) for the shell. Horseradish peroxidase (HRP), a model protein, was loaded in the core and functionalised onto the scaffold surface by coupling of protein carboxyl groups to the available polymer amine groups. Fibre morphologies were evaluated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) and functional group content was determined using X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (TOF SIMS). Hydrophobicity profiles of the fibres before and after protein loading were evaluated by water contact angle (WCA) and the mechanical properties of the electrospun scaffolds were determined by performing tensile tests. The electrospun fibre scaffolds generated by reacting PEO/PCL with 1,6-diaminohexane and those from mixing PEO/PCL with JFA were further characterised for protein conjugation and release. Fibres prepared by the mixed PEO/PCL/JFA system were found to be the most appropriate for the simultaneous release of protein from the core and the immobilisation of another protein on the shell of the same scaffold. Moreover, JFA enhanced scaffold properties in terms of porosity and elasticity. Finally, we successfully demonstrated the cytocompatibility and cell response to protein-loaded and -conjugated scaffolds using HepG2 cells. Enhanced cell attachment (2.5 fold) was demonstrated using bovine serum albumin (BSA)-conjugated scaffolds, and increased metabolic activity observed with retinoic acid (RA)-loaded scaffolds (2.7 fold).


Assuntos
Materiais Biocompatíveis/química , Polímeros/química , Soroalbumina Bovina/química , Tecidos Suporte/química , Animais , Bovinos , Células Hep G2 , Humanos , Tamanho da Partícula , Propriedades de Superfície , Engenharia Tecidual
15.
Front Med (Lausanne) ; 8: 836658, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35155489

RESUMO

The emergence of SARS-CoV-2 variants complicates efforts to control the COVID-19 pandemic. Increasing genomic surveillance of SARS-CoV-2 is imperative for early detection of emerging variants, to trace the movement of variants, and to monitor effectiveness of countermeasures. Additionally, determining the amount of viable virus present in clinical samples is helpful to better understand the impact these variants have on viral shedding. In this study, we analyzed nasal swab samples collected between March 2020 and early November 2021 from a cohort of United States (U.S.) military personnel and healthcare system beneficiaries stationed worldwide as a part of the Defense Health Agency's (DHA) Global Emerging Infections Surveillance (GEIS) program. SARS-CoV-2 quantitative real time reverse-transcription PCR (qRT-PCR) positive samples were characterized by next-generation sequencing and a subset was analyzed for isolation and quantification of viable virus. Not surprisingly, we found that the Delta variant is the predominant strain circulating among U.S. military personnel beginning in July 2021 and primarily represents cases of vaccine breakthrough infections (VBIs). Among VBIs, we found a 50-fold increase in viable virus in nasal swab samples from Delta variant cases when compared to cases involving other variants. Notably, we found a 40-fold increase in viable virus in nasal swab samples from VBIs involving Delta as compared to unvaccinated personnel infected with other variants prior to the availability of approved vaccines. This study provides important insight about the genomic and virological characterization of SARS-CoV-2 isolates from a unique study population with a global presence.

16.
Nature ; 588(7836): E2, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33199919

RESUMO

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

17.
Nature ; 586(7829): 424-428, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33029010

RESUMO

Since 1814, when rubella was first described, the origins of the disease and its causative agent, rubella virus (Matonaviridae: Rubivirus), have remained unclear1. Here we describe ruhugu virus and rustrela virus in Africa and Europe, respectively, which are, to our knowledge, the first known relatives of rubella virus. Ruhugu virus, which is the closest relative of rubella virus, was found in apparently healthy cyclops leaf-nosed bats (Hipposideros cyclops) in Uganda. Rustrela virus, which is an outgroup to the clade that comprises rubella and ruhugu viruses, was found in acutely encephalitic placental and marsupial animals at a zoo in Germany and in wild yellow-necked field mice (Apodemus flavicollis) at and near the zoo. Ruhugu and rustrela viruses share an identical genomic architecture with rubella virus2,3. The amino acid sequences of four putative B cell epitopes in the fusion (E1) protein of the rubella, ruhugu and rustrela viruses and two putative T cell epitopes in the capsid protein of the rubella and ruhugu viruses are moderately to highly conserved4-6. Modelling of E1 homotrimers in the post-fusion state predicts that ruhugu and rubella viruses have a similar capacity for fusion with the host-cell membrane5. Together, these findings show that some members of the family Matonaviridae can cross substantial barriers between host species and that rubella virus probably has a zoonotic origin. Our findings raise concerns about future zoonotic transmission of rubella-like viruses, but will facilitate comparative studies and animal models of rubella and congenital rubella syndrome.


Assuntos
Mamíferos/virologia , Filogenia , Vírus da Rubéola/classificação , Vírus da Rubéola/isolamento & purificação , Sequência de Aminoácidos , Animais , Animais de Zoológico/imunologia , Animais de Zoológico/virologia , Membrana Celular/virologia , Quirópteros/virologia , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/imunologia , Equidae/imunologia , Equidae/virologia , Evolução Molecular , Feminino , Mapeamento Geográfico , Alemanha , Especificidade de Hospedeiro , Humanos , Masculino , Mamíferos/imunologia , Marsupiais/imunologia , Marsupiais/virologia , Fusão de Membrana , Camundongos , Modelos Animais , Modelos Moleculares , Rubéola (Sarampo Alemão)/congênito , Rubéola (Sarampo Alemão)/virologia , Vírus da Rubéola/química , Vírus da Rubéola/imunologia , Alinhamento de Sequência , Uganda , Proteínas do Envelope Viral/química
18.
Viruses ; 12(7)2020 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-32659960

RESUMO

Pteropine orthoreovirus (PRV; Reoviridae: Spinareovirinae) is an emerging bat-borne zoonotic virus that causes influenza-like illness (ILI). PRV has thus far been found only in Australia and Asia, where diverse old-world fruit bats (Pteropodidae) serve as hosts. In this study, we report the discovery of PRV in Africa, in an Angolan soft-furred fruit bat (Lissonycteris angolensis ruwenzorii) from Bundibugyo District, Uganda. Metagenomic characterization of a rectal swab yielded 10 dsRNA genome segments, revealing this virus to cluster within the known diversity of PRV variants detected in bats and humans in Southeast Asia. Phylogeographic analyses revealed a correlation between geographic distance and genetic divergence of PRVs globally, which suggests a geographic continuum of PRV diversity spanning Southeast Asia to sub-Saharan Africa. The discovery of PRV in an African bat dramatically expands the geographic range of this zoonotic virus and warrants further surveillance for PRVs outside of Southeast Asia.


Assuntos
Quirópteros/virologia , Orthoreovirus , Infecções por Reoviridae/virologia , Animais , Genoma Viral/genética , Humanos , Metagenômica , Orthoreovirus/genética , Orthoreovirus/patogenicidade , Orthoreovirus/fisiologia , Filogenia , Infecções por Reoviridae/epidemiologia , Infecções por Reoviridae/veterinária , Uganda/epidemiologia , Zoonoses Virais/epidemiologia
19.
Microorganisms ; 8(5)2020 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-32429498

RESUMO

Obligate hematophagous ectoparasitic flies of the superfamily Hippoboscoidea are distributed worldwide, but their role as vectors and reservoirs of viruses remains understudied. We examined hippoboscoid bat flies (family Nycteribiidae) parasitizing Angolan soft-furred fruit bats (Lissonycteris angolensis ruwenzorii) from Bundibugyo District, Uganda. Using metagenomic methods, we detected 21 variants of the rhabdovirid genus Ledantevirus, which contains medically important "bat-associated" viruses. These 21 viruses, representing at least two divergent viral lineages, infected 26 bat flies from 8 bats in a single roost. Cophylogenetic analyses of viruses and bat flies resulted in strong evidence of virus-host codivergence, indicating vertical transmission of bat fly ledanteviruses. Examination of oral swabs from bats revealed ledantevirus RNA in the saliva of 1 out of 11 bats, with no evidence of insect genetic material in the mouth of this bat. These data demonstrate that bat flies can harbor diverse ledanteviruses even in a single roost and that the predominant mode of transmission is likely vertical (among bat flies), but that bats can become infected and shed viruses orally. In conclusion, bat flies may serve as ectoparasitic reservoirs of "bat-associated" viruses that only transiently or sporadically infect bats.

20.
Pain ; 161(1): 61-73, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31479064

RESUMO

Brain-derived neurotrophic factor (BDNF) and the high-affinity receptor tropomyosin receptor kinase B (TrkB) have important roles in neuronal survival and in spinal sensitization mechanisms associated with chronic pain. Recent clinical evidence also supports a peripheral role of BDNF in osteoarthritis (OA), with synovial expression of TrkB associated with higher OA pain. The aim of this study was to use clinical samples and animal models to explore the potential contribution of knee joint BDNF/TrkB signalling to chronic OA pain. Brain-derived neurotrophic factor and TrkB mRNA and protein were present in knee synovia from OA patients (16 women, 14 men, median age 67 years [interquartile range: 61-73]). There was a significant positive correlation between mRNA expression of NTRK2 (TrkB) and the proinflammatory chemokine fractalkine in the OA synovia. Using the surgical medial meniscal transection (MNX) model and the chemical monosodium iodoacetate (MIA) model of OA pain in male rats, the effects of peripheral BDNF injection, vs sequestering endogenous BDNF with TrkB-Fc chimera, on established pain behaviour were determined. Intra-articular injection of BDNF augmented established OA pain behaviour in MIA rats, but had no effect in controls. Intra-articular injection of the TrkB-Fc chimera acutely reversed pain behaviour to a similar extent in both models of OA pain (weight-bearing asymmetry MIA: -11 ± 4%, MNX: -12 ± 4%), compared to vehicle treatment. Our data suggesting a contribution of peripheral knee joint BDNF/TrkB signalling in the maintenance of chronic OA joint pain support further investigation of the therapeutic potential of this target.


Assuntos
Artralgia/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Dor Crônica/metabolismo , Glicoproteínas de Membrana/metabolismo , Osteoartrite do Joelho/metabolismo , Receptor trkB/metabolismo , Membrana Sinovial/metabolismo , Idoso , Animais , Artralgia/genética , Artrite Experimental/genética , Artrite Experimental/metabolismo , Fator Neurotrófico Derivado do Encéfalo/genética , Dor Crônica/genética , Feminino , Humanos , Masculino , Glicoproteínas de Membrana/genética , Pessoa de Meia-Idade , Osteoartrite do Joelho/genética , Medição da Dor , Ratos , Ratos Sprague-Dawley , Receptor trkB/genética
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