66 research outputs found
Analysis of Four New Enterococcus faecalis Phages and Modeling of a Hyaluronidase Catalytic Domain from Saphexavirus
Background: Phage therapy (PT), as a method to treat bacterial infections, needs identification of bacteriophages targeting specific pathogenic host. Enterococcus faecalis, a Gram-positive coccus resident in the human gastrointestinal tract, may become pathogenic in hospitalized patients showing acquired resistance to vancomycin and thus representing a possible target for PT.
Materials and Methods: We isolated four phages that infect E. faecalis and characterized them by host range screening, transmission electron microscopy, and genome sequencing. We also identified and three-dimensional modeled a new hyaluronidase enzyme.
Results: The four phages belong to Siphoviridae family: three Efquatrovirus (namely vB_EfaS_TV51, vB_EfaS_TV54, and vB_EfaS_TV217) and one Saphexavirus (vB_EfaS_TV16). All of them are compatible with lytic cycle. vB_EfaS_TV16 moreover presents a gene encoding for a hyaluronidase enzyme.
Conclusions: The identified phages show features suggesting their useful application in PT, particularly the Saphexavirus that may be of enhanced relevance in PT because of its potential biofilm-digestion capability
Deciphering the Role of Trehalose in Chroococcidiopsis sp. 029’s High-Desiccation Resistance: Sequence Determination, Structural Modelling and Simulative Analysis of the 30S Ribosomal Subunit
Desert strains of the genus Chroococcidiopsis are among the most desiccation-resistant
cyanobacteria capable of anhydrobiosis. The accumulation of two sugars, sucrose and trehalose,
facilitates the entrance of anhydrobiotes into a reversible state of dormancy by stabilizing cellular
components upon water removal. This study aimed to evaluate, at the atomistic level, the role
of trehalose in desiccation resistance by using as a model system the 30S ribosomal subunit of
the desert cyanobacterium Chroococcidiopsis sp. 029. Molecular dynamic simulations provided
atomistic evidence regarding its protective role on the 30S molecular structure. Trehalose forms an
enveloping shell around the ribosomal subunit and stabilizes the structures through a network of
direct interactions. The simulation confirmed that trehalose actively interacts with the 30S ribosomal
subunit and that, by replacing water molecules, it ensures ribosomal structural integrity during
desiccation, thus enabling protein synthesis to be carried out upon rehydration
Potential Use of Tea Tree Oil as a Disinfectant Agent against Coronaviruses: A Combined Experimental and Simulation Study
: The COVID-19 pandemic has highlighted the relevance of proper disinfection procedures and renewed interest in developing novel disinfectant materials as a preventive strategy to limit SARS-CoV-2 contamination. Given its widely known antibacterial, antifungal, and antiviral properties, Melaleuca alternifolia essential oil, also named Tea tree oil (TTO), is recognized as a potential effective and safe natural disinfectant agent. In particular, the proposed antiviral activity of TTO involves the inhibition of viral entry and fusion, interfering with the structural dynamics of the membrane and with the protein envelope components. In this study, for the first time, we demonstrated the virucidal effects of TTO against the feline coronavirus (FCoVII) and the human coronavirus OC43 (HCoV-OC43), both used as surrogate models for SARS-CoV-2. Then, to atomistically uncover the possible effects exerted by TTO compounds on the outer surface of the SARS-CoV-2 virion, we performed Gaussian accelerated Molecular Dynamics simulations of a SARS-CoV-2 envelope portion, including a complete model of the Spike glycoprotein in the absence or presence of the three main TTO compounds (terpinen-4-ol, γ-terpinene, and 1,8-cineole). The obtained results allowed us to hypothesize the mechanism of action of TTO and its possible use as an anti-coronavirus disinfectant agent
From In Silico Simulation between TGF-β Receptors and Quercetin to Clinical Insight of a Medical Device Containing Allium cepa: Its Efficacy and Tolerability on Post-Surgical Scars
1) objective: keloid and hypertrophic scars are a challenge in clinical management, causing functional and psychological discomfort. these pathological scars are caused by a proliferation of dermal tissue following skin injury. the TGF-beta/smad signal pathway in the fibroblasts and myofibroblasts is involved in the scarring process of skin fibrosis. today, multiple therapeutic strategies that target the TGF-beta/smad signal pathway are evaluated to attenuate aberrant skin scars that are sometimes difficult to manage. we performed a head-to-head, randomized controlled trial evaluating the appearance of the post-surgical scars of 64 subjects after two times daily topical application to compare the effect of a class I pullulan-based medical device containing allium cepa extract 5% and hyaluronic acid 5% gel versus a class I medical device silicone gel on new post-surgical wounds. (2) methods: objective scar assessment using the vancouver scar scale (VSS), POSAS, and other scales were performed after 4, 8, and 12 weeks of treatment and statistical analyses were performed. the trial was registered in clinical trials.gov ( NCT05412745). In parallel, molecular docking simulations have been performed to investigate the role of allium cepa in TGF-beta/smad signal pathway. (3) results: we showed that VSS, POSAS scale, itching, and redness reduced significantly at week 4 and 8 in the subjects using devices containing allium cepa and HA. no statistically significant differences in evaluated scores were noted at 12 weeks of treatment. safety was also evaluated by gathering adverse events related to the application of the gel. subject compliance and safety with the assigned gel were similar between the two study groups. molecular docking simulations have shown how allium cepa could inhibit fibroblasts proliferation and contraction via TGF- beta/smad signal pathway. (4) conclusions: the topical application of a pullulan-based medical device containing allium cepa and HA showed a clear reduction in the local inflammation, which might lead to a reduced probability of developing hypertrophic scars or keloids
Plant microRNAs from Moringa oleifera Regulate Immune Response and HIV Infection
Traditional medicine is often chosen due to its affordability, its familiarity with patient's cultural practices, and its wider access to the local community. Plants play an important role in providing indispensable nutrients, while specific small RNAs can regulate human gene expression in a cross-kingdom manner. The aim of the study was to evaluate the effects of plant-enriched purified extract microRNAs from Moringa oleifera seeds (MO) on the immune response and on HIV infection. Bioinformatic analysis shows that plant microRNAs (p-miRs) from MO belonging to 18 conserved families, including p-miR160h, p-miR166, p-miR482b, p-miR159c, p-miR395d, p-miR2118a, p-miR393a, p-miR167f-3p, and p-miR858b are predicted to target with high affinity BCL2, IL2RA, TNF, and VAV1, all these being involved in the cell cycle, apoptosis, immune response and also in the regulation of HIV pathogenesis. The effects of MO p-miRs transfected into HIV+ PBMCs were analyzed and revealed a decrease in viability associated with an increase of apoptosis; an increase of T helper cells expressing Fas and a decrease of intracellular Bcl2 protein expression. Meanwhile no effects were detected in PBMCs from healthy donors. In CD4(+) T cells, transfection significantly reduced cell activation and modified the T cell differentiation, thereby decreasing both central and effector memory cells while increasing terminal effector memory cells. Interestingly, the p-miRs transfection induces a reduction of intracellular HIV p24 protein and a reduction of viral DNA integration. Finally, we evaluated the effect of synthetic (mimic) p-miR858b whose sequence is present in the MO p-miR pool and predicted to target VAV1, a protein involved in HIV-Nef binding. This protein plays a pivotal role in T cell antigen receptor (TCR) signaling, so triggering the activation of various pathways. The transfection of HIV+ PBMCs with the synthetic p-miR858b showed a reduced expression of VAV1 and HIV p24 proteins. Overall, our evidence defines putative mechanisms underlying a supplementary benefit of traditional medicine, alongside current antiretroviral therapy, in managing HIV infection in resource-limited settings where MO remains widely available
Quercetin pentaacetate inhibits in vitro human respiratory syncytial virus adhesion.
Made available in DSpace on 2020-12-12T01:06:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-15 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Human respiratory syncytial virus (hRSV) is one of the main etiological agents of diseases of the lower respiratory tract and is often responsible for the hospitalization of children and the elderly. To date, treatments are only palliative and there is no vaccine available. Natural products show exceptional structural diversity and they have played a vital role in drug research. Several investigations focused on applied structural modification of natural products to improved metabolic stability, solubility and biological actions them. Quercetin is a flavonoid that presents several biological activities, including anti-hRSV role. Some works criticize the pharmacological use of Quercetin because it has low solubility and low specificity. In this sense, we acetylated Quercetin structure and we used in vitro and in silico assays to compare anti-hRSV function between Quercetin (Q0) and its derivative molecule (Q1). Q1 shows lower cytotoxic effect than Q0 on HEp-2 cells. In addition, Q1 was more efficient than Q0 to protect HEp-2 cells infected with different multiplicity of infection (0.1–1 MOI). The virucidal effects of Q0 and Q1 suggest interaction between these molecules and viral particle. Dynamic molecular results suggest that Q0 and Q1 may interact with F-protein on hRSV surface in an important region to adhesion and viral infection. Q1 interaction with F-protein showed ΔG= -14.22 kcal/mol and it was more stable than Q0. Additional, MTT and plate assays confirmed that virucidal Q1 effects occurs during adhesion step of cycle hRSV replication. In conclusion, acetylation improves anti-hRSV Quercetin effects because Quercetin pentaacetate could interact with F-protein with lower binding energy and better stability to block viral adhesion. These results show alternative anti-hRSV strategy and contribute to drug discovery and development. Universidade Estadual Paulista UNESP (FCLAssis) Universidade Estadual Paulista UNESP IBILCE Centro Multiusuário de Inovação Biomolecular (CMIB) Universidade Estadual Paulista UNESP IBILCE Department of Biology University of Rome Tor Vergata, Via della Ricerca Scientifica 1 Universidade Estadual Paulista UNESP (FCLAssis) Universidade Estadual Paulista UNESP IBILCE Centro Multiusuário de Inovação Biomolecular (CMIB) Universidade Estadual Paulista UNESP IBILCE FAPESP: 2014/12298-
Effects of antiangiogenetic drugs on microcirculation and macrocirculation in patients with advanced-stage renal cancer
Adverse cardiovascular effects, including hypertension, were described in patients with different cancers treated with tyrosine kinase inhibitors (TKI). The mechanism of TKI-related hypertension is still debated. The aim of this work was to study the effects of TKI on blood pressure (BP), searching for a relationship with possible causative factors in patients with metastatic renal cell carcinoma. We included 29 patients in a prospective, observational study; 22 were treated with a first-line drug (sunitinib), while seven participated in the second-line treatment (axitinib or cabozantinib). Patients were investigated at the beginning of antiangiogenic therapy (T0) and at one (T1), three (T2), and six months (T3) after treatment. Patients were evaluated by office blood pressure (BP) and ultrasonography to measure flow-mediated dilatation (FMD), and carotid artery distensibility (cDC) by echocardiography and nailfold capillaroscopy. Plasma endothelin-1 (p-ET-1), urine nitrates, and proteins were also measured. At T1, systolic BP, along with U proteins and p-ET-1, increased significantly. In patients with a clinically significant increase in BP (defined as either the need for an antihypertensive drug or systolic blood pressure (SBP) T1\u207bT0 6510 and/or SBP 65140 mmHg and/or diastolic blood pressure (DBP) T1\u207bT0 655 and/or DBP 6590 mmHg), the urine nitrate concentration was lower at T0, whereas there were no differences in the p-ET-1 and U proteins. Seventeen participants showed changes in the capillaroscopic pattern at T1 with no association with BP increases. There were no differences in the FMD, cDC, and echocardiographic parameters. Our findings are consistent with those of previous studies about BP increases by TKI, and suggest a role of nitric oxide in BP maintenance in this population
Neuroimaging in cluster headache and other trigeminal autonomic cephalalgias
The central nervous system mechanisms involved in trigeminal autonomic cephalalgias, a group of primary headaches characterized by strictly unilateral head pain that occurs in association with ipsilateral craniofacial autonomic features, are still not comprehensively understood. However, functional imaging methods have revolutionized our understanding of mechanisms involved in these primary headache syndromes. The present review provides a brief overview of the major modern functional neuroimaging techniques used to examine brain structure, biochemistry, metabolic state, and functional capacity. The available functional neuroimaging data in cluster headache and other TACs will thus be summarized. Although the precise brain structures responsible for these primary headache syndromes still remain to be determined, neuroimaging data suggest a major role for posterior hypothalamus activation in initiating and maintaining attacks. Furthermore, pathophysiological involvement of the pain neuromatrix and of the central descending opiatergic pain control system was observed. Given the rapid advances in functional and structural neuroimaging methodologies, it can be expected that these non-invasive techniques will continue to improve our understanding into the nature of the brain dysfunction in cluster headache and other trigeminal autonomic cephalalgias
U-CHANGE Project: a multidimensional consensus on how clinicians, patients and caregivers may approach together the new urothelial cancer scenario
IntroductionAdvanced urothelial carcinoma remains aggressive and very hard to cure, while new treatments will pose a challenge for clinicians and healthcare funding policymakers alike. The U-CHANGE Project aimed to redesign the current model of care for advanced urothelial carcinoma patients to identify limitations (“as is” scenario) and recommend future actions (“to be” scenario).MethodsTwenty-three subject-matter experts, divided into three groups, analyzed the two scenarios as part of a multidimensional consensus process, developing statements for specific domains of the disease, and a simplified Delphi methodology was used to establish consensus among the experts.ResultsRecommended actions included increasing awareness of the disease, increased training of healthcare professionals, improvement of screening strategies and care pathways, increased support for patients and caregivers and relevant recommendations from molecular tumor boards when comprehensive genomic profiling has to be provided for appropriate patient selection to ad hoc targeted therapies.DiscussionWhile the innovative new targeted agents have the potential to significantly alter the clinical approach to this highly aggressive disease, the U-CHANGE Project experience shows that the use of these new agents will require a radical shift in the entire model of care, implementing sustainable changes which anticipate the benefits of future treatments, capable of targeting the right patient with the right agent at different stages of the disease
Progettazione e caratterizzazione di nanostrutture poliedriche di DNA attraverso tecniche di modellistica e dinamica molecolare classica
La dinamica molecolare classica è stata utilizzata, unitamente a tecniche avanzate di modellistica molecolare, per caratterizzare dal punto di vista atomistico un set di nanostrutture poliedriche di DNA e per verificare il meccanismo molecolare di incapsulamento e rilascio di una biomolecola dalla cavità interna di una nanogabbia di DNA appositamente progettata per questo scopo. Lo studio di questi sistemi ha permesso di mettere in evidenza:
l’importanza della composizione nucleotidica dei linker a singolo filamento che compongono le facce quadrate della geometria troncata scelta per generare un set di nanostrutture ottaedriche di DNA. I dati ottenuti infatti indicano molto chiaramente che le nanogabbie esaminate, che condividono la stessa composizione delle doppie eliche collegate da linker con stessa lunghezza ma diversa composizione nucleotidica, possiedono un comportamento molto simile dimostrando che i vincoli imposti dalla geometria sono i fattori principali nel determinare le proprietà di questa classe di nanogabbie; la possibilità di generare una nanostruttura ottaedrica composta totalmente da doppie eliche di DNA. I dati ottenuti indicano che è possibile progettare una nano‐gabbia di DNA più rigida di quella originale con i linker a singolo filamento. Inoltre le informazioni ricavate da queste analisi confermano che variando la tipologia (ma non la sequenza) dei linker che collegano le doppie eliche strutturali è possibile realizzare nanostrutture in grado di svolgere compiti differenti: ad esempio è possibile variare in maniera molto fine il volume interno della struttura consentendo la creazione di nano‐carriers capaci di trasportare molecole di forma o dimensione differenti; la relativà semplicità con cui è ora possibile realizzare centinaia di nanostrutture di diversa forma e dimensione, che può essere utilizzato dalla comunità scientifica per progettare e testare in silico dei modelli di nanogabbie poliedriche di DNA prima della loro produzione sperimentale; In ultimo, ma non meno importante, il ruolo della dinamica molecolare nell’interpretare, da un punto di vista atomistico, un comportamento osservato a livello macroscopico, nonché di identificare un meccanismo molecolare diverso da quello ipotizzato inizialmente. Il processo di incapsulamento e rilascio controllato attraverso la temperatura di un enzima all’interno di una nanogabbia avviene infatti con bassa efficienza poiché il meccanismo inizialmente proposto, che prevedeva una apertura del reticolo della nanogabbia guidato dall’unfolding delle regioni occupate dagli hairpin‐loop, si è rivelato fondamentalmente errato. Il reale meccanismo, evidenziato dalle simulazioni, coinvolge un riarrangiamento totale dello scaffold della struttura che permette l’ingresso dell’enzima attraverso le facce del reticolo che descrive la geometria della nanogabbia
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