Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 77
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
J Sci Food Agric ; 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38975814

RESUMO

BACKGROUND: Chestnut fruit quality is affected by fungal contamination. The study of the patterns of contamination in the postharvest is crucial to individuate the critical phases and propose solutions. To understand how fungal colonization varies on fruits, the composition of mycobiota was investigated in postharvest handling and in between tissues (shell and kernel). RESULTS: Fungal sequences were clustered into 308 operational taxonomic units (OTUs). Biodiversity was higher in shell than kernel tissues. Results evidenced the risk of new contamination in specific phases such as the 'cold bath' and storage. Genera known as mycotoxin producers were detected in all phases. Specifically, 47 OTUs belonging to Penicillium, eight to Fusarium and two to Aspergillus genera were identified. While Fusarium spp. was sensitive to 'warm bath' phase, Penicillium spp. was largely insensitive and accumulated in storage conditions. Surprisingly, Aspergillus spp. was poorly represented. Aflatoxin, ochratoxin A, fumonisins and T-2/HT-2 detection was performed for shell and kernel, and process phases. Higher contamination was observed on shell than in kernel samples. While aflatoxins were within the European Union (EU) limits for dry fruits, Ochratoxin exceeded the EU limits. The present study represents the first report of fumonisins and T-2/HT-2 detection in chestnuts. CONCLUSION: Fungal contamination taxa is high in chestnut fruits following postharvest handling and storage. A parametrization of process phases such as the 'warm bath' is functional to reduce the risk for some taxa. For other spoilage and mycotoxigenic genera strict sanitation procedures of equipment and water must be individuated and implemented to reduce their impact. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

2.
J Sci Food Agric ; 104(4): 2314-2325, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-37950679

RESUMO

BACKGROUND: Botrytis cinerea (Bc) is the causative agent of gray mold disease in wine grape bunches. Under particular climatic and edaphic conditions, typical of some wine regions, the grapes infected by this fungus can develop noble rot, the basic phenomenon for the production of sweet botrytized wines or some high-quality dry wines, such as Amarone. The possibility of early detection of noble rot on plants and at postharvest is an interesting option for managing botrytized wines. RESULTS: The present work aimed at early detection of noble rot and monitoring its development, at postharvest, on Trebbiano wine grapes by means of destructive and non-destructive analytical approaches (e.g., electronic nose and near-infrared spectroscopy). The development of Bc led to substantial modifications in grape composition, including dehydration, biosynthesis, and accumulation of different compounds due to Bc metabolism, grape stress responses, or both. However, these modifications are appreciable, notably at advanced stages of infection. Consequently, a specific focus was to monitor the infection in the first 72 h post inoculation for testing, potentially through non-destructive technologies, and to identify the real early stages of Bc development. CONCLUSION: The destructive chemical analyses performed over the 16 monitored days confirmed what is widely reported in the literature regarding the metabolic/compositional changes that occur following the development of Bc. Moreover, non-destructive technologies allowed us to identify the evolution of Bc, even at early stages of its presence. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Vitis , Vinho , Vitis/química , Vinho/análise , Botrytis/fisiologia , Espectroscopia de Luz Próxima ao Infravermelho , Frutas/química
3.
BMC Plant Biol ; 23(1): 249, 2023 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-37170201

RESUMO

Truffle cultivation has quickly grown in Europe and elsewhere as a consequence of the increase in the demand of the market. Thus the optimization of the protocols for the production of elite mycorrhized plants are also needed, keeping in consideration the economic and environmental sustainability. The suitability of two compost-based potting mixes to produce Quercus pubescens Willd. plants mycorrhized with the black Périgord truffle T. melanosporum Vittad. was tested as an alternative to the traditional potting mix used. The effects on mycorrhizal development and the morphometric assessment of the root and shoot system of the Q. pubescens seedlings were investigated eight months after the spore slurry inoculation in a glasshouse experiment. From the results obtained, the compost mix containing green organic residues from pruning and mowing (Mix 2) achieved better performance than the control and the potting mix based on composted municipal organic wastes, showing significantly higher mycorrhization percentage, root length, number of root tips, and root forks. In conclusion, a potting mix containing recycled green organic matter, which is readily available, cheap, and environmentally sustainable, can offer excellent mycorrhization performances and may be included in the mycorrhization process of downy oak seedlings with T. melanosporum under controlled conditions.


Assuntos
Micorrizas , Quercus , Solo , Plântula
4.
Int J Mol Sci ; 24(24)2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38139207

RESUMO

Oncolytic viruses (OVs) are the frontier therapy for refractory cancers, especially in integration with immunomodulation strategies. In cancer immunovirotherapy, the many available "omics" and systems biology technologies generate at a fast pace a challenging huge amount of data, where apparently clashing information mirrors the complexity of individual clinical situations and OV used. In this review, we present and discuss how currently big data analysis, on one hand and, on the other, simulation, modeling, and computational technologies, provide invaluable support to interpret and integrate "omic" information and drive novel synthetic biology and personalized OV engineering approaches for effective immunovirotherapy. Altogether, these tools, possibly aided in the future by artificial intelligence as well, will allow for the blending of the information into OV recombinants able to achieve tumor clearance in a patient-tailored way. Various endeavors to the envisioned "synthesis" of turning OVs into personalized theranostic agents are presented.


Assuntos
Terapia Viral Oncolítica , Vírus Oncolíticos , Humanos , Inteligência Artificial , Vírus Oncolíticos/genética , Tecnologia , Big Data , Simulação por Computador
5.
Environ Monit Assess ; 195(5): 570, 2023 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-37059862

RESUMO

This study was undertaken with the aim of selecting one or more lichen species that are the most suitable for transplant-based surveys of air pollution in Tunisia, in areas where the local native lichen vegetation is scanty or missing at all. To this purpose, four epiphytic (tree inhabiting) lichen species (Evernia prunastri, Flavoparmelia caperata, Parmotrema perlatum, Ramalina farinacea) were collected from the Babouch forests, a remote and unpolluted area of NW Tunisia, and analyzed for their content of potentially toxic elements (PTEs), namely Al, As, Cd, Cr, Cu, Fe, Ni, Pb, Sb, and Zn, by ICP-MS. Moreover, also the physiological status of the lichen samples was evaluated by measuring their chlorophyll content, photosynthetic efficiency, and spectral reflectance. The results indicated a remarkable contribution of airborne soil and dust particles to the total PTE content, especially for the foliose species F. caperata and P. perlatum. The fruticose lichens E. prunastri and R. farinacea had a lower and similar content of PTEs, and hence were regarded as more suitable to be used in transplant studies, since are able to detect even minimal accumulation amounts. All lichen species were healthy, as emerged from the analysis of physiological parameters.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Líquens , Metais Pesados , Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Tunísia , Poluição do Ar/análise , Metais Pesados/análise
6.
Proc Natl Acad Sci U S A ; 116(40): 20141-20150, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31527243

RESUMO

Tumors utilize a number of effective strategies, including the programmed death 1/PD ligand 1 (PD-1/PD-L1) axis, to evade immune-mediated control of their growth. PD-L1 expression is mainly induced by IFN receptor signaling or constitutively induced. Integrins are an abundantly expressed class of proteins which play multiple deleterious roles in cancer and exert proangiogenic and prosurvival activities. We asked whether αvß3-integrin positively regulates PD-L1 expression and the anticancer immune response. We report that αvß3-integrin regulated constitutive and IFN-induced PD-L1 expression in human and murine cancerous and noncancerous cells. αvß3-integrin targeted STAT1 through its signaling C tail. The implantation of ß3-integrin-depleted tumor cells led to a dramatic decrease in the growth of primary tumors, which exhibited reduced PD-L1 expression and became immunologically hot, with increased IFNγ content and CD8+ cell infiltration. In addition, the implantation of ß3-integrin-depleted tumors elicited an abscopal immunotherapeutic effect measured as protection from the challenge tumor and durable splenocyte and serum reactivity to B16 cell antigens. These modifications to the immunosuppressive microenvironment primed cells for checkpoint (CP) blockade. When combined with anti-PD-1, ß3-integrin depletion led to durable therapy and elicited an abscopal immunotherapeutic effect. We conclude that in addition to its previously known roles, αvß3-integrin serves as a critical component of the cancer immune evasion strategy and can be an effective immunotherapy target.

7.
Int J Mol Sci ; 23(22)2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36430169

RESUMO

Bacterial pathogens employ a general strategy to overcome host defenses by coordinating the virulence gene expression using dedicated regulatory systems that could raise intricate networks. During the last twenty years, many studies of Helicobacter pylori, a human pathogen responsible for various stomach diseases, have mainly focused on elucidating the mechanisms and functions of virulence factors. In parallel, numerous studies have focused on the molecular mechanisms that regulate gene transcription to attempt to understand the physiological changes of the bacterium during infection and adaptation to the environmental conditions it encounters. The number of regulatory proteins deduced from the genome sequence analyses responsible for the correct orchestration of gene transcription appears limited to 14 regulators and three sigma factors. Furthermore, evidence is accumulating for new and complex circuits regulating gene transcription and H. pylori virulence. Here, we focus on the molecular mechanisms used by H. pylori to control gene transcription as a function of the principal environmental changes.


Assuntos
Infecções por Helicobacter , Helicobacter pylori , Humanos , Infecções por Helicobacter/genética , Infecções por Helicobacter/microbiologia , Fator sigma/metabolismo , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Transcrição Gênica
8.
J Sci Food Agric ; 102(14): 6596-6602, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35598330

RESUMO

BACKGROUND: Arsenic (As) may represent a risk for crop yield quality and human health since it may accumulate in the edible plant organs with the potential of leading to acute or chronic toxic effects in varied segments of the population. Management of soil fertility through compost has proven to be a valuable practice for increasing and maintaining soil organic matter, with nutritional benefits for crops. This work aimed to evaluate Swiss chard yield and the change in the bioavailability, bioaccumulation, and partitioning of As in the response of the use of compost or conventional mineral fertilization in an open-field trial conducted in a volcanic area in central Italy characterized by the natural contamination of As in soil. RESULTS: Compost treatment led to a short-term increase trend in soil organic carbon, total nitrogen, and available phosphorus in a significant way. In the compost-amended plots, the mitigation of the As uptake was detected in leaves, which are the edible part of Swiss chard. The As bioaccumulation factor in leaves of Swiss chard and the translocation factor for leaves/roots were also decreased using compost. CONCLUSION: Fertilization by compost can improve soil fertility, sustain Swiss chard production, and mitigate As accumulation in leaves of this crop grown in a naturally As-contaminated soil. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Arsênio , Beta vulgaris , Compostagem , Poluentes do Solo , Beta vulgaris/química , Carbono , Humanos , Minerais , Nitrogênio , Fósforo , Solo/química
9.
J Sci Food Agric ; 102(2): 680-687, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34171121

RESUMO

BACKGROUND: The brown rot fungus, Gnomoniopsis castanea, is the main organism responsible for the outbreak of chestnut postharvest decay that is threatening the sustainability of the chestnut market in Europe. Currently, no specific strategy is available to mitigate the impact and remediate the high losses of fruits in postharvest storage. In the present study, the different phases of chestnut handling in a standard facility plant were analyzed by evaluating the amount of fruit rot and infection by G. castanea at each phase. RESULTS: The warm bath (48 °C) was identified as the critical phase, requiring strict parametrization to effectively inactivate G. castanea in fruits. Laboratory tests indicated that maintaining fruits at 50 °C for a maximum of 45 min provided optimal conditions to completely inactivate G. castanea inoculum during postharvest handling. However, the warm bath at 50 °C and over was not effective in inactivating the complex of fungal taxa responsible for contamination and development of molds. Higher temperatures and extended treatment times caused significant losses in fruit quality, as indicated by taste panel evaluation. Upscaling of postharvest facilities is discussed and critically evaluated. CONCLUSION: The warm bath (50 °C for 45 min) is effective in completely inactivating G. castanea in fruits but did not reduce the impacts of the complex of molds responsible for external contamination and mycotoxin production. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.


Assuntos
Ascomicetos/fisiologia , Fagaceae/microbiologia , Conservação de Alimentos/métodos , Doenças das Plantas/microbiologia , Ascomicetos/genética , Ascomicetos/crescimento & desenvolvimento , Fagaceae/crescimento & desenvolvimento , Frutas/crescimento & desenvolvimento , Frutas/microbiologia , Temperatura Alta , Doenças das Plantas/prevenção & controle
10.
Adv Exp Med Biol ; 1290: 67-80, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33559855

RESUMO

The great hopes raised by the discovery of the immunoregulatory cytokine interleukin 12 (IL-12) as an anticancer agent were marred during early clinical experimentation because of severe adverse effects, which prompted a search for alternative formulations and routes of administration. Onco-immunotherapeutic viruses (OIVs) are wild-type or genetically engineered viruses that exert antitumor activity by causing death of the tumor cells they infect and by overcoming a variety of immunosuppressive mechanisms put in place by the tumors. OIVs have renewed the interest in IL-12, as they offer the opportunity to encode the cytokine transgenically from the viral genome and to produce it at high concentrations in the tumor bed. A large body of evidence indicates that IL-12 serves as a potent adjuvant for the immunotherapeutic response elicited by OIVs in murine tumor models. The list of OIVs includes onco-immunotherapeutic herpes simplex, adeno, measles, Newcastle disease, and Maraba viruses, among others. The large increase in IL-12-mediated adjuvanticity was invariably observed for all the OIVs analyzed. Indirect evidence suggests that locally delivered IL-12 may also increase tumor antigenicity. Importantly, the OIV/IL-12 treatment was not accompanied by adverse effects and elicited a long-lasting immune response capable of halting the growth of distant tumors. Thus, OIVs provide an avenue for reducing the clinical toxicity associated with systemic IL-12 therapy, by concentrating the cytokine at the site of disease. The changes to the tumor microenvironment induced by the IL-12-armed OIVs primed the tumors to an improved response to the checkpoint blockade therapy, suggesting that the triple combination is worth pursuing in the future. The highly encouraging results in preclinical models have prompted translation to the clinic. How well the IL-12-OIV-checkpoint inhibitors' combination will perform in humans remains to be fully investigated.


Assuntos
Terapia Viral Oncolítica , Vírus Oncolíticos , Animais , Humanos , Imunoterapia , Interleucina-12/genética , Camundongos , Vírus Oncolíticos/genética , Microambiente Tumoral
11.
PLoS Pathog ; 14(8): e1007209, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30080893

RESUMO

Oncolytic herpes simplex viruses (oHSVs) showed efficacy in clinical trials and practice. Most of them gain cancer-specificity from deletions/mutations in genes that counteract the host response, and grow selectively in cancer cells defective in anti-viral response. Because of the deletions/mutations, they are frequently attenuated or over-attenuated. We developed next-generation oHSVs, which carry no deletion/mutation, gain cancer-specificity from specific retargeting to tumor cell receptors-e.g. HER2 (human epidermal growth factor receptor 2)-hence are fully-virulent in the targeted cancer cells. The type of immunotherapy they elicit was not predictable, since non-attenuated HSVs induce and then dampen the innate response, whereas deleted/attenuated viruses fail to contrast it, and since the retargeted oHSVs replicate efficiently in tumor cells, but spare other cells in the tumor. We report on the first efficacy study of HER2-retargeted, fully-virulent oHSVs in immunocompetent mice. Their safety profile was very high. Both the unarmed R-LM113 and the IL-12-armed R-115 inhibited the growth of the primary HER2-Lewis lung carcinoma-1 (HER2-LLC1) tumor, R-115 being constantly more efficacious. All the mice that did not die because of the primary treated tumors, were protected from the growth of contralateral untreated tumors. The long-term survivors were protected from a second contralateral tumor, providing additional evidence for an abscopal immunotherapeutic effect. Analysis of the local response highlighted that particularly R-115 unleashed the immunosuppressive tumor microenvironment, i.e. induced immunomodulatory cytokines, including IFNγ, T-bet which promoted Th1 polarization. Some of the tumor infiltrating cells, e.g. CD4+, CD335+ cells were increased in the tumors of all responders mice, irrespective of which virus was employed, whereas CD8+, Foxp3+, CD141+ were increased and CD11b+ cells were decreased preferentially in R-115-treated mice. The durable response included a breakage of tolerance towards both HER2 and the wt tumor cells, and underscored a systemic immunotherapeutic vaccine response.


Assuntos
Antineoplásicos/farmacologia , Vacinas Anticâncer/farmacologia , Imunoterapia Ativa/métodos , Interleucina-12 , Terapia Viral Oncolítica/métodos , Simplexvirus , Animais , Carcinoma Pulmonar de Lewis/tratamento farmacológico , Camundongos , Vírus Oncolíticos
12.
Ecotoxicol Environ Saf ; 204: 111117, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32798753

RESUMO

Wood distillate (pyroligneous acid) can be successfully applied in agriculture to increase crop quality and productivity with a lower risk for the environment respect to synthetic chemical herbicides, pesticides or fertilizers. However, the effects of wood distillate on the environment and biota are still under investigation, depending on biological attributes of potentially influenced organisms. The potential toxicological effects of wood distillate on sensitive non-target organisms, lichens and mosses, are studied for the first time. The physiological parameters (chlorophyll a fluorescence emission FV/FM and PI(ABS), chlorophyll content, spectral reflectance, antioxidant power, and dehydrogenase activity) and eventual bioaccumulation of selected elements (As, Ba, Cd, Cr, Cu, Fe, Ni, Pb, Zn) were investigated in the lichen Xanthoria parietina and the moss Hypnum cupressiforme after short-term treatments over a range of wood distillate solutions (1:300, 1:500, 1:700) to detect potential early stress responses. Overall, the lichen did not show changes after the treatments, while in the moss wood distillate caused only modest alterations in FV/FM and PI(ABS) and progressive increasing of antioxidant activity according to the dose supplied. The bioaccumulation of toxic elements was low and did not show any pattern of uptake with increasing concentrations of wood distillate.


Assuntos
Briófitas/efeitos dos fármacos , Herbicidas/toxicidade , Líquens/efeitos dos fármacos , Terpenos/toxicidade , Poluentes Atmosféricos/análise , Ascomicetos/efeitos dos fármacos , Briófitas/química , Bryopsida , Clorofila/farmacologia , Clorofila A , Biomarcadores Ambientais , Monitoramento Ambiental/métodos , Madeira/química
13.
J Virol ; 92(6)2018 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-29263257

RESUMO

Oncolytic viruses gain cancer specificity in several ways. Like the majority of viruses, they grow better in cancer cells that are defective in mounting the host response to viruses. Often, they are attenuated by deletion or mutation of virulence genes that counteract the host response or are naturally occurring oncolytic mutants. In contrast, retargeted viruses are not attenuated or deleted; their cancer specificity rests on a modified, specific tropism for cancer receptors. For herpes simplex virus (HSV)-based oncolytics, the detargeting-retargeting strategies employed so far were based on genetic modifications of gD. Recently, we showed that even gH or gB can serve as retargeting tools. To enable the growth of retargeted HSVs in cells that can be used for clinical-grade virus production, a double-retargeting strategy has been developed. Here we show that several sites in the N terminus of gB are suitable to harbor the 20-amino-acid (aa)-long GCN4 peptide, which readdresses HSV tropism to Vero cells expressing the artificial GCN4 receptor and thus enables virus cultivation in the producer noncancer Vero-GCN4R cell line. The gB modifications can be combined with a minimal detargeting modification in gD, consisting in the deletion of two residues, aa 30 and 38, and replacement of aa 38 with the scFv to human epidermal growth factor receptor 2 (HER2), for retargeting to the cancer receptor. The panel of recombinants was analyzed comparatively in terms of virus growth, cell-to-cell spread, cytotoxicity, and in vivo antitumor efficacy to define the best double-retargeting strategy.IMPORTANCE There is increasing interest in oncolytic viruses, following FDA and the European Medicines Agency (EMA) approval of HSV OncovexGM-CSF, and, mainly, because they greatly boost the immune response to the tumor and can be combined with immunotherapeutic agents, particularly checkpoint inhibitors. A strategy to gain cancer specificity and avoid virus attenuation is to retarget the virus tropism to cancer-specific receptors of choice. Cultivation of fully retargeted viruses is challenging, since they require cells that express the cancer receptor. We devised a strategy for their cultivation in producer noncancer Vero cell derivatives. Here, we developed a double-retargeting strategy, based on insertion of one ligand in gB for retargeting to a Vero cell derivative and of anti-HER2 ligand in gD for cancer retargeting. These modifications were combined with a minimally destructive detargeting strategy. This study and its companion paper explain the clinical-grade cultivation of retargeted oncolytic HSVs and promote their translation to the clinic.


Assuntos
Herpesvirus Humano 1 , Neoplasias Experimentais/terapia , Terapia Viral Oncolítica , Vírus Oncolíticos , Anticorpos de Cadeia Única , Proteínas do Envelope Viral , Animais , Linhagem Celular Tumoral , Chlorocebus aethiops , Herpesvirus Humano 1/genética , Herpesvirus Humano 1/metabolismo , Humanos , Camundongos , Camundongos Transgênicos , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Vírus Oncolíticos/genética , Vírus Oncolíticos/metabolismo , Anticorpos de Cadeia Única/genética , Anticorpos de Cadeia Única/metabolismo , Células Vero , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Bull Environ Contam Toxicol ; 100(3): 430-437, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29335758

RESUMO

This study investigated the occurrence of toxicity, expressed as damage to the photosynthetic apparatus, in the aquatic fern Azolla filiculoides and the lichen Xanthoria parietina following treatments with diclofenac at different concentrations (0.1, 1, 10 and 100 mg/L) and different exposure times (24, 48, 72 and 240 h). Measurements of photosynthetic efficiency, chlorophyll content and chlorophyll degradation indicated dose- and time-dependent toxicity, since significant differences with control samples as well as among treatments, emerged mainly for the highest concentration (100 mg/L) and the longest time (240 h). In addition, also the mycobiont of the lichen X. parietina showed similar toxic effects, expressed as ergosterol content. The absence of relevant alterations at the lowest concentration (0.1 mg/L) suggested a very limited susceptibility of these species to environmentally relevant levels of this pharmaceutical.


Assuntos
Diclofenaco/toxicidade , Gleiquênias/efeitos dos fármacos , Líquens/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Clorofila/metabolismo , Relação Dose-Resposta a Droga , Ergosterol/metabolismo , Gleiquênias/metabolismo , Líquens/metabolismo
15.
Cell Mol Life Sci ; 73(16): 3151-68, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-26863876

RESUMO

Small regulatory RNAs (sRNAs) are emerging as key post-transcriptional regulators in many bacteria. In the human pathobiont Helicobacter pylori a plethora of trans- and cis-encoded sRNAs have been pinpointed by a global transcriptome study. However, only two have been studied in depth at the functional level. Here we report the characterization of CncR1, an abundant and conserved sRNA encoded by the virulence-associated cag pathogenicity island (cag-PAI) of H. pylori. Growth-phase dependent transcription of CncR1 is directed by the PcagP promoter, which resulted to be a target of the essential transcriptional regulator HsrA (HP1043). We demonstrate that the 213 nt transcript arising from this promoter ends at an intrinsic terminator, few bases upstream of the annotated cagP open reading frame, establishing CncR1 as the predominant gene product encoded by the cagP (cag15) locus. Interestingly, the deletion of the locus resulted in the deregulation en masse of σ(54)-dependent genes, linking CncR1 to flagellar functions. Accordingly, the enhanced motility recorded for cncR1 deletion mutants was complemented by ectopic reintroduction of the allele in trans. In silico prediction identified fliK, encoding a flagellar checkpoint protein, as likely regulatory target of CncR1. The interaction of CncR1 with the fliK mRNA was thus further investigated in vitro, demonstrating the formation of strand-specific interactions between the two RNA molecules. Accordingly, the full-length translational fusions of fliK with a lux reporter gene were induced in a cncR1 deletion mutant in vivo. These data suggest the involvement of CncR1 in the post-transcriptional modulation of H. pylori motility functions through down-regulation of a critical flagellar checkpoint factor. Concurrently, the cncR1 mutant revealed a decrease of transcript levels for several H. pylori adhesins, resulting in a phenotypically significant impairment of bacterial adhesion to a host gastric cell line. The data presented support a model in which the cag-PAI encoded CncR1 sRNA is able to oppositely modulate bacterial motility and adhesion to host cells.


Assuntos
Regulação Bacteriana da Expressão Gênica , Infecções por Helicobacter/metabolismo , Infecções por Helicobacter/microbiologia , Helicobacter pylori/genética , Helicobacter pylori/fisiologia , RNA Bacteriano/genética , Pequeno RNA não Traduzido/genética , Aderência Bacteriana , Proteínas de Bactérias/genética , Ilhas Genômicas , Helicobacter pylori/patogenicidade , Interações Hospedeiro-Parasita , Humanos , Regiões Promotoras Genéticas , RNA Mensageiro/genética , Transcriptoma
16.
Ecotoxicol Environ Saf ; 122: 193-7, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26247898

RESUMO

This study investigated if treatment of the lichen Xanthoria parietina (L.) Th. Fr. with glyphosate caused uptake of this herbicide as well as physiological alterations. Samples were treated with Glifene SL®, a common commercial glyphosate-based herbicide, at the lowest recommended doses (3.6g/L) as well as with doses slightly higher than the highest suggested (36 g/L). The results clearly showed glyphosate uptake in X. parietina proportionally to the dose provided. Adverse physiological effects were evident on the photosynthetic apparatus (photosynthetic efficiency, chlorophyll a content, chlorophyll degradation) as well as on the fungal respiration rates and cell membrane integrity (ergosterol content, dehydrogenase activity) already after 24h from treatment, also at the low application dose. It is concluded that lichens are suitable organisms for monitoring unwanted biological effects from the application of glyphosate-based herbicides, as well as for detecting the accumulation of this compound in the biota, thus screening for its environmental fate.


Assuntos
Glicina/análogos & derivados , Herbicidas/toxicidade , Líquens/efeitos dos fármacos , Ascomicetos/efeitos dos fármacos , Transporte Biológico , Clorofila/metabolismo , Clorofila A , Monitoramento Ambiental/métodos , Ergosterol/metabolismo , Glicina/farmacocinética , Glicina/toxicidade , Herbicidas/farmacocinética , Líquens/metabolismo , Líquens/fisiologia , Oxirredutases/metabolismo , Fotossíntese/efeitos dos fármacos , Glifosato
17.
Environ Sci Technol ; 48(15): 8754-9, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24971640

RESUMO

The uptake kinetics of elemental gaseous Hg (Hg(0)) in three species of epiphytic lichens (Pseudevernia furfuracea, Evernia prunastri, and Xanthoria parietina) were investigated under four different Hg concentrations (10, 15, 30, and 45 µg/m(3)) and three different temperatures (10, 20, and 30 °C) with the aim of evaluating the lichen efficiency for Hg(0) accumulation and their potential use in the estimate of atmospheric concentrations of this metal in the field. The results showed that under our experimental conditions the lichens accumulated Hg according to exposure time and that the metal is not released back to the atmosphere after Hg(0) was removed from the air (clearance). Pseudevernia furfuracea showed the highest Hg accumulation capacity and Evernia prunastri showed the lowest, but in these species the metal uptake kinetics was affected by temperature. Xanthoria parietina showed an intermediate metal accumulation capacity and a Hg accumulation rate independent of temperature (in the range 10-30 °C). The use of first-order kinetics equations for Hg uptake in X. parietina and available field data on Hg bioaccumulation in this species allowed reliable estimates of atmospheric Hg concentrations in the environment.


Assuntos
Monitoramento Ambiental/métodos , Líquens/química , Mercúrio/análise , Ascomicetos , Atmosfera/química , Metais , Temperatura
18.
Heliyon ; 10(4): e26526, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38404867

RESUMO

Salt stress is presently a major environmental concern, given the huge number of soils affected by the presence of dissolved salts. Therefore, it is necessary to find solutions, preferably nature-based ones, to deal with this problem. In this study, biochar, a product made from plant biomass residues through the process of pyrolysis, was tested to alleviate salt stress on lettuce (Lactuca sativa L.) plants. Six different concentrations of NaCl were tested: 0, 50, 100, 200, 300 and 400 mM with and without the addition of 5% (w/w) biochar. Biochar ability to mitigate salinity damage was assessed by means of both biometric (fresh weight), physiological (chlorophyll content), and biochemical (i.e., electrolyte leakage, total antioxidant power, total soluble proteins, free amino acids, and mineral content) parameters. The experiment lasted four weeks. The results showed that NaCl has a negative effect from the concentration of 100-200 mM and that biochar was to some extent effective in mitigating the negative effects of salt on plant physiology; nevertheless, biochar failed to counteract Na accumulation. Similarly, biochar did not influence the content of free amino acids in lettuce leaves, but enhanced the expression of several parameters, such as total antioxidant power, fresh weight, chlorophyll content, total soluble protein, K content, although only clearly evident in some cases. Overall, the present study showed that biochar is a viable solution to counteract the damage caused by high salt concentrations on plant growth.

19.
Cancers (Basel) ; 16(6)2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38539478

RESUMO

The role of the interaction with cell-surface glycosaminoglycans (GAGs) during in vivo HSV infection is currently unknown. The rationale of the current investigation was to improve the anticancer efficacy of systemically administered retargeted oHSVs (ReHVs) by decreasing their binding to GAGs, including those of endothelial cells, blood cells, and off-tumor tissues. As a proof-of-principle approach, we deleted seven amino acids critical for interacting with GAGs from the glycoprotein C (gC) of R-337 ReHV. The modification in the resulting R-399 recombinant prolonged the half-life in the blood of systemically administered R-399 and enhanced its biodistribution to tumor-positive lungs and to the tumor-negative liver. Ultimately, it greatly increased the R-399 efficacy against metastatic-like lung tumors upon IV administration but not against subcutaneous tumors upon IT administration. These results provide evidence that the increased efficacy seen upon R-399 systemic administration correlated with the slower clearance from the circulation. To our knowledge, this is the first in vivo evidence that the partial impairment of the gC interaction with GAGs resulted in a prolonged half-life of circulating ReHV, an increase in the amount of ReHV taken up by tissues and tumors, and, ultimately, an enhanced anticancer efficacy of systemically administered ReHV.

20.
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA