227 research outputs found

    PaCATB, a secreted catalase protecting Podospora anserina against exogenous oxidative stress

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    A differential mass spectrometry analysis of secreted proteins from juvenile and senescent Podospora anserina cultures revealed age-related differences in protein profiles. Among other proteins with decreased abundance in the secretome of senescent cultures a catalase, termed PaCATB, was identified. Genetic modulation of the abundance of PaCATB identified differential effects on the phenotype of the corresponding strains. Deletion of PaCatB resulted in decreased resistance, over-expression in increased resistance against hydrogen peroxide. While the lifespan of the genetically modified strains was found to be unaffected under standard growth conditions, increased exogenous hydrogen peroxide stress in the growth medium markedly reduced the lifespan of the PaCatB deletion strain but extended the lifespan of PaCatB over-expressors. Overall our data identify a component of the secretome of P. anserina as a new effective factor to cope with environmental stress, stress that under natural conditions is constantly applied on organisms and influences aging processes

    Leucoagaricus gongylophorus uses leaf-cutting ants to vector proteolytic enzymes towards new plant substrate

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    The mutualism between leaf-cutting ants and their fungal symbionts revolves around processing and inoculation of fresh leaf pulp in underground fungus gardens, mediated by ant fecal fluid deposited on the newly added plant substrate. As herbivorous feeding often implies that growth is nitrogen limited, we cloned and sequenced six fungal proteases found in the fecal fluid of the leaf-cutting ant Acromyrmex echinatior and identified them as two metalloendoproteases, two serine proteases and two aspartic proteases. The metalloendoproteases and serine proteases showed significant activity in fecal fluid at pH values of 5–7, but the aspartic proteases were inactive across a pH range of 3–10. Protease activity disappeared when the ants were kept on a sugar water diet without fungus. Relative to normal mycelium, both metalloendoproteases, both serine proteases and one aspartic protease were upregulated in the gongylidia, specialized hyphal tips whose only known function is to provide food to the ants. These combined results indicate that the enzymes are derived from the ingested fungal tissues. We infer that the five proteases are likely to accelerate protein extraction from plant cells in the leaf pulp that the ants add to the fungus garden, but regulatory functions such as activation of proenzymes are also possible, particularly for the aspartic proteases that were present but without showing activity. The proteases had high sequence similarities to proteolytic enzymes of phytopathogenic fungi, consistent with previous indications of convergent evolution of decomposition enzymes in attine ant fungal symbionts and phytopathogenic fungi

    Peanut stunt virus and its satellite RNA trigger changes in phosphorylation in N-benthamiana infected plants at the early stage of the infection

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    Signaling in host plants is an integral part of a successful infection by pathogenic RNA viruses. Therefore, identifying early signaling events in host plants that play an important role in establishing the infection process will help our understanding of the disease process. In this context, phosphorylation constitutes one of the most important post-translational protein modifications, regulating many cellular signaling processes. In this study, we aimed to identify the processes affected by infection with Peanut stunt virus (PSV) and its satellite RNA (satRNA) in Nicotiana benthamiana at the early stage of pathogenesis. To achieve this, we performed proteome and phosphoproteome analyses on plants treated with PSV and its satRNA. The analysis of the number of differentially phosphorylated proteins showed strong down-regulation in phosphorylation in virus-treated plants (without satRNA). Moreover, proteome analysis revealed more down-regulated proteins in PSV and satRNA-treated plants, which indicated a complex dependence between proteins and their modifications. Apart from changes in photosynthesis and carbon metabolism, which are usually observed in virus-infected plants, alterations in proteins involved in RNA synthesis, transport, and turnover were observed. As a whole, this is the first community (phospho)proteome resource upon infection of N. benthamiana with a cucumovirus and its satRNA and this resource constitutes a valuable data set for future studies

    Comparison of the Proteomes of Three Yeast Wild Type Strains: CEN.PK2, FY1679 and W303

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    Yeast deletion strains created during gene function analysis projects very often show drastic phenotypic differences depending on the genetic background used. These results indicate the existence of important molecular differences between the CEN.PK2, FY1679 and W303 wild type strains. To characterise these differences we have compared the protein expression levels between CEN.PK2, FY1679 and W303 strains using twodimensional gel electrophoresis and identified selected proteins by mass spectrometric analysis. We have found that FY1679 and W303 strains are more similar to each other than to the CEN.PK2 strain. This study identifies 62 proteins that are differentially expressed between the strains and provides a valuable source of data for the interpretation of yeast mutant phenotypes observed in CEN.PK2, FY1679 and W303 strains

    The care for older people during the COVID-19 pandemic : an overview of the situation in Poland

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    AUTHORS' DEDICATION: “During the time this paper was being prepared for publication, our scientific mentor and friend, a retired professor at the Warsaw University of Life Sciences, Maria-Okret Zajaczkowska, passed away. We wish to dedicate this work to her memory.”PURPOSE: The research aims to review and assess the situation of the old adults as well as formal and informal elderly care in Poland at the time of Covid-19.DESIGN/METHODOLOGY/APPROACH: It includes, inter alia, the relevant literature overview, short characteristics of the structure of care facilities for the elderly and the sources of their financing, changes related to the pandemic and their consequences, identification of the main socio-economic problems of caregivers, and the impact of the pandemic on the health, dignity, and well-being of older adults. The study uses secondary data from the national statistics, Eurostat, OECD as well as primary data from the survey addressed to the older persons and their formal and informal carers (including family members), that was conducted to examine economic, financial, social, and health condition both of caregivers and care receivers during the pandemic.FINDINGS: The study is situated within the domain of the economics of care, health economics, behavioural economics, and social policy. It provides an important contribution to the understanding of the challenges faced both by the most vulnerable people who need support and providers of this support during the crises like the COVID-19 pandemic.PRACTICAL IMPLICATIONS: Research shows that public long-term care for the elderly in Poland does not sufficiently meet the needs, while commercial facilities are too expensive long-term care solutions, which is why the care is mostly provided in-home by relatives. Moreover, during Covid-19, the burden on families with caring for older people increased compared with "normal" times.peer-reviewe

    Secondary Vitrectomy with Internal Limiting Membrane Plug due to Persistent Full-Thickness Macular Hole OCT-Angiography and Microperimetry Features: Case Series

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    Purpose. To study the features in OCT-angiography and microperimetry in eyes with persistent full-thickness macular hole (FTMH) closed with the secondary plana vitrectomy (PPV) with autologous internal limiting membrane (ILM) plug. Methods. Secondary PPV was performed with closing the persistent FTMH with ILM plug, C3F8 tamponade, and face-down positioning. Four patients were followed for 6 months with best corrected visual acuity (BCVA) measurement, SD-OCT and OCT-A, and microperimetry. The results were compared with the fellow eye; in two patients, it was the healthy eye, and in two remaining eyes, successfully closed FTMH after primary PPV. Results. ILM flap was integrated in all cases with V-shape of closure, and atrophy was found in one case, with the largest diameter of FTMH. BCVA improved in two cases and remained the same in two cases. In OCT-A, the area of foveal avascular zone (FAZ) was larger, and foveal vessel density (FVDS) was smaller in eyes after secondary PPV in comparison to fellow eyes. In microperimetry, retinal sensitivity was lower in eyes after secondary PPV, and eccentric fixation was found in 2 of 4 patients. Conclusion. Although the anatomical results of repeated surgeries of FTMH with ILM plug are favorable, visual function results may be limited. Secondary closure of FTMH with ILM plug may lead to atrophy, changes in the macular vasculature, and eccentric fixation. The trial is registered with NCT03701542

    Secondary Vitrectomy with Internal Limiting Membrane Plug due to Persistent Full-Thickness Macular Hole OCT-Angiography and Microperimetry Features: Case Series

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    Purpose. To study the features in OCT-angiography and microperimetry in eyes with persistent full-thickness macular hole (FTMH) closed with the secondary plana vitrectomy (PPV) with autologous internal limiting membrane (ILM) plug. Methods. Secondary PPV was performed with closing the persistent FTMH with ILM plug, C3F8 tamponade, and face-down positioning. Four patients were followed for 6 months with best corrected visual acuity (BCVA) measurement, SD-OCT and OCT-A, and microperimetry. The results were compared with the fellow eye; in two patients, it was the healthy eye, and in two remaining eyes, successfully closed FTMH after primary PPV. Results. ILM flap was integrated in all cases with V-shape of closure, and atrophy was found in one case, with the largest diameter of FTMH. BCVA improved in two cases and remained the same in two cases. In OCT-A, the area of foveal avascular zone (FAZ) was larger, and foveal vessel density (FVDS) was smaller in eyes after secondary PPV in comparison to fellow eyes. In microperimetry, retinal sensitivity was lower in eyes after secondary PPV, and eccentric fixation was found in 2 of 4 patients. Conclusion. Although the anatomical results of repeated surgeries of FTMH with ILM plug are favorable, visual function results may be limited. Secondary closure of FTMH with ILM plug may lead to atrophy, changes in the macular vasculature, and eccentric fixation. The trial is registered with NCT03701542

    Vertical and Horizontal M-Charts and Microperimetry for Assessment of the Visual Function in Patients after Vitrectomy with ILM Peeling due to Stage 4 Macular Hole

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    Purpose. To examine the relationship between the morphological and functional results in eyes after pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling due to stage 4 full-thickness macular hole (FTMH). Methods. The study included 22 eyes that underwent successful PPV due to FTMH. Both vertical metamorphopsia (VM) and horizontal metamorphopsia (HM) were determined using type 2 M-charts, as well as best-corrected visual acuity (BCVA), microperimetry, and optical coherence tomography (OCT) were performed before PPV and 1 and 6 months postoperatively. Results. A significant improvement of BCVA and metamorphopsia scores measured by M-charts in particular periods before surgery, 1 and 6 months after PPV, was observed. The VM scores were consistently higher than the HM scores at all assessment times. There was a correlation found between VM and BCVA and microperimetry parameters before surgery. The macular sensitivity (MS) as well as macular integrity index increased from 1 month to 6 months after PPV and were correlated with postoperative visual acuity (VA). There was a correlation found between the hole diameter and MS and P2 parameter 6 months after PPV. There was a correlation found between mean duration of symptoms of FTMH and VA and VM score. Conclusions. VM scores seem to correlate better than HM scores with preoperative BCVA, microperimetry parameters, and duration of symptoms of the FTMH. VM scores are higher after PPV than HM scores in patients with stage 4 of the FTMH. This trial is registered with NCT03701542
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