108 research outputs found
Absence of Cu–Zn superoxide dismutase BCSOD1 reduces Botrytiscinerea virulence in Arabidopsis and tomato plants, revealinginterplay among reactive oxygen species, callose and signallingpathways
Plants activate responses against pathogens, including the oxida-tive burst. Necrotrophic pathogens can produce reactive oxygenspecies (ROS) that benefit the colonization process. Previously, wehave demonstrated that tomato plants challenged with Botrytiscinerea accumulate ROS and callose, together with the inductionof genes involved in defence, signalling and oxidative metabolism.Here, we studied the infection phenotype of the Dbcs od1 strain inboth tomato and Arabidopsis plants. This mutant lacks bcsod1,which encodes Cu–Zn superoxide dismutase (SOD). This enzymecatalyses the conversion of superoxide ion (O–2) into hydrogen per-oxide (H2O2). ROS play a protective role and act as signals inplants. Dbcsod1 displayed reduced virulence compared with wild-type B05.10 in both species. Plants infected with Dbcsod1 accu-mulated less H2O2and more O–2than those infected with B05.10,which is associated with an increase in the defensive polymer cal-lose. This supports a major role of fungal SOD in H2O2productionduring the plant–pathogen interaction. The early induction of thecallose synthase gene PMR4 suggested that changes in ROSaltered plant defensive responses at the transcriptional level. Themetabolites and genes involved in signalling and in response tooxidative stress were differentially expressed on Dbcsod1 infec-tion, supporting the notion that plants perceive changes in ROSbalance and activate defence responses. A higher O2–/H2O2ratioseems to be beneficial for plant protection against this necrotroph.Our results highlight the relevance of callose and the oxylipin 12-oxo-phytodienoic acid (OPDA) in the response to changes in theoxidative environment, and clarify the mechanisms that underliethe responses to Botrytis in Arabidopsis and tomato plants.This work was supported by grants from the Spanish Ministry of Scienceand Innovation (AGL2010-22300-C03-01-02 and AGL2013-49023-C03-01-02), co-funded by the European Regional Development Funds (ERDF)and by Generalitat Valenciana Grupos de Excelencia PROMETEO/2012/066. J.L.-C. and O.C.-S. were recipients of research contracts from thePROMETEO/2012/066 grant. E.F.-C. was the recipient of research con-tracts from grant AGL2010-22300-C03-01. J.L.-C. is the recipient of aresearch contract from grant AGL2013-49023-C03-01
Priming of plant resistance by natural compounds. Hexanoic acid as a model
Some alternative control strategies of currently emerging plant diseases are based on the use of resistance inducers. This review highlights the recent advances made in the characterization of natural compounds that induce resistance by a priming mechanism. These include vitamins, chitosans, oligogalacturonides, volatile organic compounds, azelaic and pipecolic acid, among others. Overall, other than providing novel disease control strategies that meet environmental regulations, natural priming agents are valuable tools to help unravel the complex mechanisms underlying the induced resistance (IR) phenomenon. The data presented in this review reflect the novel contributions made from studying these natural plant inducers, with special emphasis placed on hexanoic acid (Hx), proposed herein as a model tool for this research field. Hx is a potent natural priming agent of proven efficiency in a wide range of host plants and pathogens. It can early activate broad-spectrum defenses by inducing callose deposition and the salicylic acid (SA) and jasmonic acid (JA) pathways. Later it can prime pathogen-specific responses according to the pathogen’s lifestyle. Interestingly, Hx primes redox-related genes to produce an anti-oxidant protective effect, which might be critical for limiting the infection of necrotrophs. Our Hx-IR findings also strongly suggest that it is an attractive tool for the molecular characterization of the plant alarmed state, with the added advantage of it being a natural compound.This work was supported by grants from the Spanish Ministry of Science and Innovation (AGL2010-22300-C03-01-02-03) co-funded by European Regional Development Fund (ERDF) and Generalitat Valenciana Grupos de Excelencia (PROMETEO/2012/066). Maria de la O Leyva and Ivan Finiti were recipients of a research contract from AGL2010-22300-C03-01. We thank the SCIE Greenhouse section at the University of Valencia and the SCIC at the Universitat Jaume I for technical support
The Questionnaire of Intention to Help in VAW Cases (QIHVC): Development and preliminary results
Introduction: Violence against women (VAW) is a worldwide social and health
problem of epidemic proportions. This violence is preventable, and bystander
programs are one of the possible preventative strategies. The main purpose of
this research was to develop a tool that, by applying a contrastive methodology
for its application in different forms of violence (forms of gender-based violence,
such as intimate partner VAW, sexual harassment at work, and street harassment,
and common violence, such as a robbery), would allow measuring the probability
of occurrence of bystander response in the face of these types of violence with
good evidence of content validity.
Method: Firstly (Study 1), an initial version of a measure tool, the Questionnaire
of Intention to Help in VAW Cases (QIHVC), was developed; secondly (Study 2), a
Delphi (modified) study was carried out to obtain valid, content-based evidence;
and finally (Study 3), a pilot study was carried out to evaluate the appropriate
functioning of the QIHVC and, if required, to make any necessary adjustments.
Results and discussion: The main result is the development of a set of case
scenarios and a questionnaire related to its content which constitutes the QIHVC
and, in its initial approximation, seems to constitute an adequate and sensible tool
to capture the differences between the characterizations of common violence
and VAW and in the possible response of bystanders in the face of such violenc
Bisphenol-A Induces Podocytopathy With Proteinuria in Mice
Bisphenol-A, a chemical used in the production of the plastic lining of food and beverage containers, can be found in significant levels in human fluids. Recently, bisphenol-A has been associated with low-grade albuminuria in adults as well as in children. Since glomerular epithelial cells (podocytes) are commonly affected in proteinuric conditions, herein we explored the effects of bisphenol-A on podocytes in vitro and in vivo. On cultured podocytes we first observed that bisphenol-A?at low or high concentrations?(10?nM and 100?nM, respectively) was able to induce hypertrophy, diminish viability, and promote apoptosis. We also found an increase in the protein expression of TGF-?1 and its receptor, the cyclin-dependent kinase inhibitor p27Kip1, as well as collagen-IV, while observing a diminished expression of the slit diaphragm proteins nephrin and podocin. Furthermore, mice intraperitoneally injected with bisphenol-A (50?mg/Kg for 5 weeks) displayed an increase in urinary albumin excretion and endogenous creatinine clearance. Renal histology showed mesangial expansion. At ultrastructural level, podocytes displayed an enlargement of both cytoplasm and foot processes as well as the presence of condensed chromatin, suggesting apoptosis. Furthermore, immunohistochemistry for WT-1 (specific podocyte marker) and the TUNEL technique showed podocytopenia as well as the presence of apoptosis, respectively. In conclusion, our data demonstrate that Bisphenol-A exposure promotes a podocytopathy with proteinuria, glomerular hyperfiltration and podocytopenia. Further studies are needed to clarify the potential role of bisphenol-A in the pathogenesis as well as in the progression of renal diseases.Ministerio de Ciencia e InnovaciónInstituto de Salud Carlos IIIThe Eugenio Rodríguez Pascual Foundatio
The Histone Marks Signature in Exonic and Intronic Regions Is Relevant in Early Response of Tomato Genes to Botrytis cinerea and in miRNA Regulation
Research into the relationship between epigenetic regulation and resistance to biotic stresses provides alternatives for plant protection and crop improvement. To unravel the mechanisms underlying tomato responses to Botrytis cinerea, we performed a chromatin immunoprecipitation (ChIP) analysis showing the increase in H3K9ac mark along the early induced genes SlyDES, SlyDOX1, and SlyLoxD encoding oxylipin-pathway enzymes, and SlyWRKY75 coding for a transcriptional regulator of hormonal signaling. This histone mark showed a more distinct distribution than the previously studied H3K4me3. The RNAPol-ChIP analysis reflected the actual gene transcription associated with increased histone modifications. A different pattern of marks in the oxylipin-related genes against P. syringae supported a pathogen-specific profile, while no significant differences occurred in SlyWRKY75. The epigenetic regulation of SlyWRKY75 by the intron-binding miR1127-3p was supported by the presence of SlyWRKY75 pre-mRNA in control plants. Interestingly, mRNA was found to be accumulated in response to B. cinerea and P. syringae, while reduction in miRNA only occurred against B. cinerea. The intronic region presented a similar pattern of marks than the rest of the gene in both pathosystems, except for H3K4me3 in the miRNA binding site upon B. cinerea. We located the gene encoding Sly-miR1127-3p, which presented reduced H3K4me3 on its promoter against B. cinerea
Relationship Between Biofilm Formation and Antimicrobial Resistance in Gram-Negative Bacteria
Gram-negative microorganisms are a significant cause of
infection in both community and nosocomial settings. The
increase, emergence, and spread of antimicrobial resistance
among bacteria are the most important health problems worldwide.
One of the mechanisms of resistance used by bacteria is biofilm
formation, which is also a mechanism of virulence. This study
analyzed the possible relationship between antimicrobial
resistance and biofilm formation among isolates of three
Gram-negative bacteria species. Several relationships were found
between the ability to form biofilm and antimicrobial
resistance, being different for each species. Indeed, gentamicin
and ceftazidime resistance was related to biofilm formation in
Escherichia coli, piperacillin/tazobactam, and colistin in
Klebsiella pneumoniae, and ciprofloxacin in Pseudomonas
aeruginosa. However, no relationship was observed between global
resistance or multidrug-resistance and biofilm formation. In
addition, compared with other reported data, the isolates in the
present study showed higher rates of antimicrobial resistance.
In conclusion, the acquisition of specific antimicrobial
resistance can compromise or enhance biofilm formation in
several species of Gram-negative bacteria. However,
multidrug-resistant isolates do not show a trend to being
greater biofilm producers than non-multiresistant isolates
Cellular vaccines in listeriosis: role of the Listeria antigen GAPDH
The use of live Listeria-based vaccines carries serious difficulties when administrated to immunocompromised individuals. However, cellular carriers have the advantage of inducing multivalent innate immunity as well as cell-mediated immune responses, constituting novel and secure vaccine strategies in listeriosis. Here, we compare the protective efficacy of dendritic cells (DCs) and macrophages and their safety. We examined the immune response of these vaccine vectors using two Listeria antigens, listeriolysin O (LLO) and glyceraldehyde-3-phosphate-dehydrogenase (GAPDH), and several epitopes such as the LLO peptides, LLO189-201 and LLO91-99 and the GAPDH peptide, GAPDH1-22. We discarded macrophages as safe vaccine vectors because they show anti-Listeria protection but also high cytotoxicity. DCs loaded with GAPDH1-22 peptide conferred higher protection and security against listeriosis than the widely explored LLO91-99 peptide. Anti-Listeria protection was related to the changes in DC maturation caused by these epitopes, with high production of interleukin-12 as well as significant levels of other Th1 cytokines such as monocyte chemotactic protein-1, tumor necrosis factor-α, and interferon-γ, and with the induction of GAPDH1-22-specific CD4(+) and CD8(+) immune responses. This is believed to be the first study to explore the use of a novel GAPDH antigen as a potential DC-based vaccine candidate for listeriosis, whose efficiency appears to highlight the relevance of vaccine designs containing multiple CD4(+) and CD8(+) epitopes
Doñana. Acta vertebrata. vol 23 (1)
Variaciones geográfica y temporal en la dieta de la lechuza campestre (Asio flammeus) en EuropaVariaciones estacionales en la dieta de la lechuza común (Tyto alba) en dos nidos de diferente localizaciónDinámica anual de la comunidad de paseriformes en carrizales costeros del sudeste ibéricoSedentarismo, áreas de campeo y selección de microhábitats en el lagarto verdinegro Lacerta schreiberEstudio morfométrico y del crecimiento de Apodemus sylvaticus L., 1758 (Rodentia, Muridae) en el norte de la Península IbéricaLas Gaviotas patiamarillas (Larus cachinnans) de la colonia de las Islas Medes (NE de España) como posibles agentes transmisores de contaminación microbiana.Dieta de la garduña (Martes foina Erxlebeb, 1777) en una localidad de las sierras subbéticas de Granada (sureste de España)Situación del lince ibérico en la Sierra de GataNotas sobre la reproducción de una población semicautiva de tortuga mediterránea Testudo hermanni en Valencia (E, España)Peer reviewe
Prevalence, antimicrobial resistance and serotype distribution of group B streptococcus isolated among pregnant women and newborns in Rabat, Morocco
PURPOSE: Group B streptococcus (GBS) is an important cause of
neonatal sepsis worldwide. Data on the prevalence of maternal
GBS colonization, risk factors for carriage, antibiotic
susceptibility and circulating serotypes are necessary to tailor
adequate locally relevant public health policies. METHODOLOGY: A
prospective study including pregnant women and their newborns
was conducted between March and July 2013 in Morocco. We
collected clinical data and vagino-rectal and urine samples from
the recruited pregnant women, together with the clinical
characteristics of, and body surface samples from, their
newborns. Additionally, the first three newborns admitted every
day with suspected invasive infection were recruited for a
thorough screening for neonatal sepsis. Serotypes were
characterized by molecular testing. RESULTS: A total of 350
pregnant women and 139 of their newborns were recruited. The
prevalence of pregnant women colonized by GBS was 24 %. In 5/160
additional sick newborns recruited with suspected sepsis, the
blood cultures were positive for GBS. Gestational hypertension
and vaginal pruritus were significantly associated with a
vagino-rectal GBS colonization in univariate analyses. All of
the strains were susceptible to penicillin, while 7 % were
resistant to clindamycin and 12 % were resistant to
erythromycin. The most common GBS serotypes detected included V,
II and III. CONCLUSION: In Morocco, maternal GBS colonization is
high. Penicillin can continue to be the cornerstone of
intrapartum antibiotic prophylaxis. A pentavalent GBS vaccine
(Ia, Ib, II, III and V) would have been effective against the
majority of the colonizing cases in this setting, but a
trivalent one (Ia, Ib and III) would only prevent 28 % of the
cases
The anti-aging factor Klotho protects against acquired long QT syndrome induced by uremia and promoted by fibroblast growth factor 23
[Background]: Chronic kidney disease (CKD) is associated with increased propensity for arrhythmias. In this context, ventricular repolarization alterations have been shown to predispose to fatal arrhythmias and sudden cardiac death. Between mineral bone disturbances in CKD patients, increased fibroblast growth factor (FGF) 23 and decreased Klotho are emerging as important effectors of cardiovascular disease. However, the relationship between imbalanced FGF23-Klotho axis and the development of cardiac arrhythmias in CKD remains unknown.
[Methods]: We carried out a translational approach to study the relationship between the FGF23–Klotho signaling axis and acquired long QT syndrome in CKD-associated uremia. FGF23 levels and cardiac repolarization dynamics were analyzed in patients with dialysis-dependent CKD and in uremic mouse models of 5/6 nephrectomy (Nfx) and Klotho deficiency (hypomorphism), which show very high systemic FGF23 levels.
[Results]: Patients in the top quartile of FGF23 levels had a higher occurrence of very long QT intervals (> 490 ms) than peers in the lowest quartile. Experimentally, FGF23 induced QT prolongation in healthy mice. Similarly, alterations in cardiac repolarization and QT prolongation were observed in Nfx mice and in Klotho hypomorphic mice. QT prolongation in Nfx mice was explained by a significant decrease in the fast transient outward potassium (K+) current (Itof), caused by the downregulation of K+ channel 4.2 subunit (Kv4.2) expression. Kv4.2 expression was also significantly reduced in ventricular cardiomyocytes exposed to FGF23. Enhancing Klotho availability prevented both long QT prolongation and reduced Itof current. Likewise, administration of recombinant Klotho blocked the downregulation of Kv4.2 expression in Nfx mice and in FGF23-exposed cardiomyocytes.
[Conclusion]: The FGF23–Klotho axis emerges as a new therapeutic target to prevent acquired long QT syndrome in uremia by minimizing the predisposition to potentially fatal ventricular arrhythmias and sudden cardiac death in patients with CKD.This work was supported by projects from the Instituto de Salud Carlos III, Ministry of Economy, Industry and Competitiveness (PI17/01093, PI17/01193, PI20/00763, CP15/00129, F18/00261, CPII20/00022, SAF2017-84777-R, PID2020-113238RB-I00), from the Sociedad Española de Cardiología (SEC), and from the Fundación Renal Íñigo Alvarez de Toledo (FRIAT), co-funded by the European Regional Development Fund (Fondos FEDER)
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