63 research outputs found

    Evidence for the involvement of the Arabidopsis SEC24A in male transmission

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    Eukaryotic cells use COPII-coated carriers for endoplasmic reticulum (ER)-to-Golgi protein transport. Selective cargo capture into ER-derived carriers is largely driven by the SEC24 component of the COPII coat. The Arabidopsis genome encodes three AtSEC24 genes with overlapping expression profiles but it is yet to be established whether the AtSEC24 proteins have overlapping roles in plant growth and development. Taking advantage of Arabidopsis thaliana as a model plant system for studying gene function in vivo, through reciprocal crosses, pollen characterization, and complementation tests, evidence is provided for a role for AtSEC24A in the male gametophyte. It is established that an AtSEC24A loss-of-function mutation is tolerated in the female gametophyte but that it causes defects in pollen leading to failure of male transmission of the AtSEC24A mutation. These data provide a characterization of plant SEC24 family in planta showing incompletely overlapping functions of the AtSEC24 isoforms. The results also attribute a novel role to SEC24 proteins in a multicellular model system, specifically in male fertility

    Hepatocellular apoptosis during Candida albicans colonization: Involvement of TNF-α and infiltrating Fas-L positive lymphocytes

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    The liver constitutes the first barrier in the control of hematogenous dissemination of Candida albicans of intestinal origin. In rats infected with C. albicans, this organ limits the growth of the yeast and mounts an efficient inflammatory reaction. However, in rats infected and exposed to chronic varied stress, the hepatic inflammatory reaction is compromised and the outcoming of the infection is more severe. Although in both groups the fungal burden is associated with hepatotoxicity, steatosis, increment of hepatic enzymes and lipid peroxidation, stress-related differences are clearly evident. Herein, we evaluated in infected and infected-stressed hosts the involvement of apoptosis and pro-apoptotic signals in the hepatic injury during the acute step of C. albicans infection. We studied in situ apoptosis by 4â€Č,6-diamidino-2-phenylindole dihydrochloride and terminal deoxynucleotidyl transferase dUTP nick-end labeling reactions, the levels of local tumor necrosis factor (TNF)-α mRNA by reverse transcription-PCR and the Fas/Fas-L expression by immunohistochemistry and western blot. We also purified intrahepatic lymphocytes (IHLs) to evaluate the dynamic of recruitment following the infection and to characterize the in vivo and in vitro interaction of C. albicans with this subset evaluating the kinetic of Fas-L and Toll-like receptor-2 (TLR-2) expression. This work shows, for the first time, the occurrence of in situ apoptosis of hepatocytes as well as the kinetic of IHL recruitment early during the C. albicans infection. Moreover, our results demonstrate the ability of the fungus to up-regulate the Fas-L and TLR-2 expression in this subset. In the scenario of early liver injury, the recruited IHLs and the modulated expression of TNF-α, Fas-L and TLR-2 molecules could act coordinately in delivering death signals.Fil: Renna, Maria Sol. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico CĂłrdoba. Centro de Investigaciones en BioquĂ­mica ClĂ­nica e InmunologĂ­a; Argentina. Universidad Nacional de CĂłrdoba. Facultad de Ciencias QuĂ­micas; ArgentinaFil: Correa, Silvia Graciela. Universidad Nacional de CĂłrdoba. Facultad de Ciencias QuĂ­micas; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico CĂłrdoba. Centro de Investigaciones en BioquĂ­mica ClĂ­nica e InmunologĂ­a; ArgentinaFil: Porporatto, Carina. Universidad Nacional de CĂłrdoba. Facultad de Ciencias QuĂ­micas; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico CĂłrdoba. Centro de Investigaciones en BioquĂ­mica ClĂ­nica e InmunologĂ­a; ArgentinaFil: Figueredo, Carlos Mauricio. Universidad Nacional de CĂłrdoba. Facultad de Ciencias QuĂ­micas; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico CĂłrdoba. Centro de Investigaciones en BioquĂ­mica ClĂ­nica e InmunologĂ­a; ArgentinaFil: Aoki, Maria del Pilar. Universidad Nacional de CĂłrdoba. Facultad de Ciencias QuĂ­micas; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico CĂłrdoba. Centro de Investigaciones en BioquĂ­mica ClĂ­nica e InmunologĂ­a; ArgentinaFil: Paraje, MarĂ­a Gabriela. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico CĂłrdoba. Centro de Investigaciones en BioquĂ­mica ClĂ­nica e InmunologĂ­a; Argentina. Universidad Nacional de CĂłrdoba. Facultad de Ciencias QuĂ­micas; ArgentinaFil: Sotomayor, Claudia Elena. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico CĂłrdoba. Centro de Investigaciones en BioquĂ­mica ClĂ­nica e InmunologĂ­a; Argentina. Universidad Nacional de CĂłrdoba. Facultad de Ciencias QuĂ­micas; Argentin

    Candida albicans up-regulates the Fas-L expression in liver Natural Killer and Natural Killer T cells

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    After Candida albicans arrival to the liver, the local production of proinflammatory cytokines and the expanded intrahepatic lymphocytes (IHL) can be either beneficial or detrimental to the host. Herein we explored the balance between protective inflammatory reaction and liver damage, focusing our study on the contribution of TNF-α and Fas-Fas-L pathways in the hepatocellular apoptosis associated to C. albicans infection. A robust tissue reaction and a progressive increase of IL-1ÎČ, IL-6 and TNF-α were observed in infected animals. Blocking the biological activity of TNF-α did not modify the number of apoptotic cells observed in C. albicans infected animals. Fas-L molecule was up regulated on purified hepatic mononuclear cells and its expression progressed with the infection. In the IHL compartment, the absolute number of Fas-L+ NK and NKT cells increased on days 1 and 3 of the infection. C. albicans was also able to up regulate Fas-L expression in normal liver NK and NKT cells after in vitro contact. The innate receptor TLR2 was involved in this phenomenon. In the interplay between host factors and evasion strategies exploited by pathogens, the mechanism supported here could represent an additional way that allows this fungus to circumvent protective immune responses in the liver.Fil: Renna, Maria Sol. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico CĂłrdoba. Centro de Investigaciones en BioquĂ­mica ClĂ­nica e InmunologĂ­a; ArgentinaFil: Figueredo, Carlos Mauricio. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico CĂłrdoba. Centro de Investigaciones en BioquĂ­mica ClĂ­nica e InmunologĂ­a; ArgentinaFil: Rodriguez Galan, Maria Cecilia. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico CĂłrdoba. Centro de Investigaciones en BioquĂ­mica ClĂ­nica e InmunologĂ­a; ArgentinaFil: Icely, Paula Alejandra. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico CĂłrdoba. Centro de Investigaciones en BioquĂ­mica ClĂ­nica e InmunologĂ­a; ArgentinaFil: Cejas, Hugo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico CĂłrdoba. Centro de Investigaciones en BioquĂ­mica ClĂ­nica e InmunologĂ­a; ArgentinaFil: Cano, Roxana Carolina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico CĂłrdoba. Centro de Investigaciones en BioquĂ­mica ClĂ­nica e InmunologĂ­a; ArgentinaFil: Correa, Silvia Graciela. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico CĂłrdoba. Centro de Investigaciones en BioquĂ­mica ClĂ­nica e InmunologĂ­a; ArgentinaFil: Sotomayor, Claudia Elena. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico CĂłrdoba. Centro de Investigaciones en BioquĂ­mica ClĂ­nica e InmunologĂ­a; Argentin

    IGF-1 receptor antagonism inhibits autophagy

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    Inhibition of the insulin/insulin-like growth factor signalling pathway increases lifespan and protects against neurodegeneration in model organisms, and has been considered as a potential therapeutic target. This pathway is upstream of mTORC1, a negative regulator of autophagy. Thus, we expected autophagy to be activated by insulin-like growth factor-1 (IGF-1) inhibition, which could account for many of its beneficial effects. Paradoxically, we found that IGF-1 inhibition attenuates autophagosome formation. The reduced amount of autophagosomes present in IGF-1R depleted cells can be, at least in part, explained by a reduced formation of autophagosomal precursors at the plasma membrane. In particular, IGF-1R depletion inhibits mTORC2, which, in turn, reduces the activity of protein kinase C (PKCa/b). This perturbs the actin cytoskeleton dynamics and decreases the rate of clathrin-dependent endocytosis, which impacts autophagosome precursor formation. Finally, with important implications for human diseases, we demonstrate that pharmacological inhibition of the IGF-1R signalling cascade reduces autophagy also in zebrafish and mice models. The novel link we describe here has important consequences for the interpretation of genetic experiments in mammalian systems and for evaluating the potential of targeting the IGF-1R receptor or modulating its signalling through the downstream pathway for therapeutic purposes under clinically relevant conditions, such as neurodegenerative diseases, where autophagy stimulation is considered beneficial.This is the version of the manuscript that was first published on line. The final version can be found published in Human Molecular Genetics by OUP here: http://hmg.oxfordjournals.org/content/22/22/4528.full.pdf+html

    Il Bilancio di Genere dell’Ateneo federiciano: dal rapporto di genere all’istituzionalizzazione del processo

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    [Italiano]:Le UniversitĂ , in quanto enti di formazione e di ricerca, sono tenute a mettere in atto azioni e politiche volte a garantire la paritĂ  di genere e a rimuovere gli ostacoli che impediscono la piena realizzazione personale e professionale di uomini e donne. A tale scopo il Bilancio di Genere Ăš lo strumento d’elezione per perseguire gli obiettivi di paritĂ . Ma piĂč che di un documento, si tratta di un vero e proprio articolato processo che richiede un significativo coinvolgimento della governance di Ateneo, attraverso un percorso di istituzionalizzazione dell’approccio alle questioni di genere. Il volume presenta gli esiti del secondo bilancio di genere della Federico II di Napoli, redatto secondo le Linee Guida elaborate dalla Conferenza dei Rettori delle UniversitĂ  Italiane. Oltre all’analisi di contesto, che consente di evidenziare i punti di forza e gli elementi di criticitĂ  dell’Ateneo federiciano rispetto alla paritĂ  di genere, il documento illustra il livello di integrazione della prospettiva di genere nei documenti strategici di Ateneo, la rete di organismi preposti alle tematiche di genere e il repertorio delle azioni messe in atto nel quinquennio precedente. L’analisi di genere degli impegni economico-finanziari, realizzata a partire dalla riclassificazione del bilancio, ha consentito inoltre di esplorare nel dettaglio le risorse espressamente destinate agli obiettivi di paritĂ , identificando gli ambiti in cui Ăš necessario investire maggiormente. Il documento include inoltre una prima analisi in ottica di genere dei questionari di rilevazione delle opinioni degli studenti e delle studentesse, che puĂČ essere adoperata come utile strumento per fornire spunti per la definizione di azioni positive destinate alla popolazione studentesca. Il quadro che emerge dall’analisi proposta Ăš quello di un Ateneo che ha intrapreso un serio percorso di istituzionalizzazione dell’intero ciclo del Bilancio di Genere, attestato dall’impegno nella promozione di processi culturali ed organizzativi inclusivi volti a perseguire concretamente gli obiettivi di uguaglianza e di paritĂ  nella formazione, nella ricerca e nel lavoro. ./[English]:Universities, as training and research institutions, are required to implement actions and policies aimed at ensuring gender equality and at removing obstacles that prevent the full personal and professional fulfilment of men and women. To this end, the Gender Responsive Budgeting is the fundamental tool to pursue the objectives of equality. But more than a document, it is an articulated process that requires a significant involvement of the governance of the University, through a path of institutionalization of the approach to the gender issues. The volume presents the results of the second gender report of the University Federico II of Naples, drawn up according to the Conference of Rectors of Italian Universities Guidelines. In addition to the context analysis, which allows to highlight strengths and critical issues of the University with respect to gender equality, the document illustrates the level of integration of the gender perspective in the University's strategic documents, the network of bodies responsible for gender issues and the repertoire of actions implemented in the previous five years. The gender analysis of economic and financial commitments, carried out through the reclassification of the budget, has also made it possible to explore in detail the resources expressly allocated to the equality objectives, identifying the areas in which greatest investments are needed. The document also includes a preliminary gender analysis of student opinion questionnaires, which can be used as a useful tool to provide insights into the definition of positive actions for the student population. The picture that emerges from the proposed analysis is of a University that has embarked on a serious path of institutionalization of the gender budget process, attested by the commitment to promote inclusive cultural and organizational processes aimed at concretely pursuing equality objectives in training, research and work
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