135 research outputs found

    Modulation of utrophin A mRNA stability in fast versus slow muscles via an AU-rich element and calcineurin signaling

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    We examined the role of post-transcriptional mechanisms in controlling utrophin A mRNA expression in slow versus fast skeletal muscles. First, we determined that the half-life of utrophin A mRNA is significantly shorter in the presence of proteins isolated from fast muscles. Direct plasmid injection experiments using reporter constructs containing the full-length or truncated variants of the utrophin 3′UTR into slow soleus and fast extensor digitorum longus muscles revealed that a region of 265 nucleotides is sufficient to confer lower levels of reporter mRNA in fast muscles. Further analysis of this region uncovered a conserved AU-rich element (ARE) that suppresses expression of reporter mRNAs in cultured muscle cells. Moreover, stability of reporter mRNAs fused to the utrophin full-length 3′UTR was lower in the presence of fast muscle protein extracts. This destabilization effect seen in vivo was lost upon deletion of the conserved ARE. Finally, we observed that calcineurin signaling affects utrophin A mRNA stability through the conserved ARE. These results indicate that ARE-mediated mRNA decay is a key mechanism that regulates expression of utrophin A mRNA in slow muscle fibers. This is the first demonstration of ARE-mediated mRNA decay regulating the expression of a gene associated with the slow myogenic program

    Troglitazone Induces Extracellular Matrix and Cytoskeleton Remodeling in Mouse Collecting Duct Cells

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    Peroxisome proliferator-activated receptor (PPARγ) has been shown to have a protective role in the nephron through its ability to inhibit a transforming growth factor- (TGF-β) mediated fibrotic response. In contrast, PPARγ was also shown to induce a mesenchymal transformation in epithelial intestinal cells. A fibrotic response in the collecting duct has only recently been established; however, the entire collecting duct has not been fully examined. Inner medullary collecting duct cells (IMCD-K2) and mouse cortical collecting duct cells (M1), representing the cortical and medullary collecting duct, were exposed to 5–10 μM troglitazone for 24 hours. Troglitazone resulted in an elongated morphology, 60% decreases in E-cadherin and β-catenin, a 35% decrease in α-catenin, and a 1.5-fold increase in fibronectin. These effects were not reversed with PPARγ antagonists or affected with PPARγ overexpression. Our results indicate that troglitazone induced a mesenchymal-like transformation in M1 and IMCD-K2 epithelial cells independently of PPARγ

    Troglitazone Induces Extracellular Matrix and Cytoskeleton Remodeling in Mouse Collecting Duct Cells

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    Peroxisome proliferator-activated receptor (PPARγ) has been shown to have a protective role in the nephron through its ability to inhibit a transforming growth factor- (TGF-β) mediated fibrotic response. In contrast, PPARγ was also shown to induce a mesenchymal transformation in epithelial intestinal cells. A fibrotic response in the collecting duct has only recently been established; however, the entire collecting duct has not been fully examined. Inner medullary collecting duct cells (IMCD-K2) and mouse cortical collecting duct cells (M1), representing the cortical and medullary collecting duct, were exposed to 5–10 μM troglitazone for 24 hours. Troglitazone resulted in an elongated morphology, 60% decreases in E-cadherin and β-catenin, a 35% decrease in α-catenin, and a 1.5-fold increase in fibronectin. These effects were not reversed with PPARγ antagonists or affected with PPARγ overexpression. Our results indicate that troglitazone induced a mesenchymal-like transformation in M1 and IMCD-K2 epithelial cells independently of PPARγ

    Indução de ovulação em pacientes com tumor estrogênio‐dependente: diretrizes clínicas da Sociedade Brasileira de Reprodução Humana

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    ResumoA oncofertilidade é um campo de interesse interdisciplinar de desenvolvimento recente que busca mesclar os conhecimentos em oncologia e medicina reprodutiva, com a contribuição das técnicas de reprodução assistida, para o desenvolvimento de estratégias de preservação da função gonadal e oferecer a possibilidade da procriação biológica aos sobreviventes de câncer. As estratégias de preservação da fertilidade feminina em pacientes oncológicas atualmente aceitas para a prática rotineira são a criopreservação de embriões e a criopreservação de oócitos maduros. Ocorre que, para execução de ambos, a indução de ovulação é obrigatória e, com ela, vêm os riscos teóricos de estimulação do crescimento de tumores estrogênio‐dependentes e a postergação do início do tratamento antineoplásico. Os protocolos de estimulação ovariana de início aleatório contemplam a intenção de se minimizar o atraso no início da quimioterapia ou radioterapia e o bloqueio ao crescimento tumoral e oferecem resultados satisfatórios, semelhantes aos obtidos em protocolos de início habitual. Apresentamos neste artigo as diretrizes clínicas da Sociedade Brasileira de Reprodução Humana para indução de ovulação em pacientes com tumor estrogênio‐dependente.AbstractOncofertility is an interdisciplinary interest field of recent development, which aims to merge the knowledge in oncology and reproductive medicine, with the help of assisted reproductive technologies, to develop strategies for gonadal function preservation and to offer the possibility of biological procreation to cancer survivors. Preservation strategies of female fertility in oncological patients currently accepted for routine practice are the cryopreservation of embryos and cryopreservation of mature oocytes. It happens that ovulation induction is mandatory for executing both strategies, and with it the theoretical risk of stimulation of estrogen‐dependent tumors growth and the postponement of anti‐neoplastic treatment. Random‐start ovarian stimulation protocols include the intention of minimizing the delay in onset of chemo‐radiotherapy and to block tumor growth, providing satisfactory results, similar to those obtained in the usual beginning protocols. This article presents the clinical guidelines of the Brazilian Society of Human Reproduction for ovulation induction in patients with estrogen‐dependent tumors

    1,7-Dihydr­oxy-2,3,4-trimeth­oxy-9H-xanthen-9-one monohydrate from Halenia elliptica

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    The title compound, C16H14O7·H2O, possesses a planar three-ring skeleton; its carbonyl, one of the two hydroxy and two of the three methoxy O atoms and the water mol­ecule form hydrogen bonds, giving rise to a layer structure

    Arabidopsis thaliana SPF1 and SPF2 are nuclear-located ULP2-like SUMO proteases that act downstream of SIZ1 in plant development

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    Post-translational modifiers such as the small ubiquitin-like modifier (SUMO) peptide act as fast and reversible protein regulators. Functional characterization of the sumoylation machinery has determined the key regulatory role that SUMO plays in plant development. Unlike components of the SUMO conjugation pathway, SUMO proteases (ULPs) are encoded by a relatively large gene family and are potential sources of specificity within the pathway. This study reports a thorough comparative genomics and phylogenetic characterization of plant ULPs, revealing the presence of one ULP1-like and three ULP2-like SUMO protease subgroups within plant genomes. As representatives of an under-studied subgroup, Arabidopsis SPF1 and SPF2 were subjected to functional characterization. Loss-of-function mutants implicated both proteins with vegetative growth, flowering time, and seed size and yield. Mutants constitutively accumulated SUMO conjugates, and yeast complementation assays associated these proteins with the function of ScUlp2 but not ScUlp1. Fluorescence imaging placed both proteins in the plant cell nucleoplasm. Transcriptomics analysis indicated strong regulatory involvement in secondary metabolism, cell wall remodelling, and nitrate assimilation. Furthermore, developmental defects of the spf1-1 spf2-2 (spf1/2) double-mutant opposed those of the major E3 ligase siz1 mutant and, most significantly, developmental and transcriptomic characterization of the siz1 spf1/2 triple-mutant placed SIZ1 as epistatic to SPF1 and SPF2.We thank Mark Hochstrasser (Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT, USA) for kindly providing the ulp1-ts yeast mutant strain. This research was funded by FEDER (through COMPETE), and by Fundacao para a Ciencia e Tecnologia (FCT), within the scope of project SUMOdulator (FCOMP-01-0124-FEDER-028459 and PTDC/BIA-PLA/3850/2012). PHC was supported by FCT (SFRH/BD/44484/2008). HA and FF were supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (FEDER) (NORTE-01-0145-FEDER-000007 and Norte-01-0145-FEDER-000008, respectively). The work was supported by FEDER through the COMPETE 2020-Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT, within the framework of projects 'Rede de Investigacao em Biodiversidade e Biologia Evolutiva' (POCI-01-0145-FEDER-006821) and 'Institute for Research and Innovation in Health Sciences' (POCI-01-0145-FEDER-007274). This research was also supported by a grant from the Spanish Ministerio de Ciencia y Tecnologia (AGL2016-75819-C2-1-R) and FEDER (PCQ, AGC, ERB)

    Eficácia e pH de caldas de glifosato após a adição de fertilizantes nitrogenados e utilização de pulverizador pressurizado por CO2

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    This work was developed with the objective of evaluating the efficacy and the pH of glyphosate spray solutions after the addition of nitrogen fertilizers and the use of CO2-pressurized sprayer. In field conditions, two rates of glyphosate (360 and 720 g ha-1) were applied either alone or combined with two concentrations of urea (2.5 and 5.0 g L-1) or ammonium sulfate (7.5 and 15.0 g L-1). In laboratory, the pH of the glyphosate solutions was measured after using different concentrations of the product and nitrogen fertilizers and after using a CO2-pressurized sprayer. For all field condition evaluations, the lowest glyphosate rate had higher biological efficacy after the addition of ammonium sulfate (15 g L-1) to the spray solution. Urea (5 g L-1) promoted benefits only at the 28th-day evaluation. In laboratory, the increase of glyphosate concentration promoted gradual acidification of the spray solution, which stabilized at pH 4.5. Ammonium sulfate caused minor acidification of the herbicide solution, whereas urea did not change the pH. The use of CO2-pressurized sprayer had small effect on the solution's pH. Highest glyphosate efficacy identified after the addition of nitrogen fertilizers has little relation with changes on the solution's pH.Este trabalho foi desenvolvido com o objetivo de avaliar a eficácia e o pH de caldas de glifosato após a adição de fertilizantes nitrogenados e utilização de pulverizador pressurizado por CO2. Em campo, foram aplicadas duas doses de glifosato (360 e 720 g ha-1), isoladas ou combinadas a duas concentrações de ureia (2,5 e 5,0 g L-1) ou sulfato de amônio (7,5 e 15,0 g L-1). Em laboratório, mensurou-se o pH de caldas de glifosato após o uso de diferentes concentrações do produto e dos fertilizantes nitrogenados e após a utilização do pulverizador pressurizado por CO2. Em todas as avaliações do experimento em campo, a menor dose de glifosato teve maior eficácia biológica após a adição de sulfato de amônio (15 g L-1) à calda. A ureia (5 g L-1) proporcionou efeitos benéficos somente na avaliação aos 28 dias após a aplicação. Em laboratório, o aumento da concentração de glifosato promoveu gradativa acidificação da calda de pulverização, com estabilização do pH da solução em 4,5. O sulfato de amônio causou pequena acidificação da calda herbicida, enquanto a ureia não alterou o pH. O uso do pulverizador pressurizado por CO2 pouco alterou o pH da calda de glifosato. A maior eficácia do glifosato após a adição de fertilizantes nitrogenados à calda está pouco relacionada com alterações no pH da solução

    Protection of rat renal vitamin E levels by ischemic-preconditioning

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    BACKGROUND: During renal transplantation, the kidney remains without blood flow for a period of time. The following reperfusion of this ischemic kidney causes functional and structural injury. Formation of oxygen-derived free radicals (OFR) and subsequent lipid peroxidation (LP) has been implicated as the causative factors of these injuries. Vitamin E is known to be the main endogenous antioxidant that stabilizes cell membranes by interfering with LP. The present study was designed to examine the role of ischemic-preconditioning (repeated brief periods of ischemia, IPC) in prevention of renal injury caused by ischemia-reperfusion (IR) in rats. METHODS: IPC included sequential clamping of the right renal artery for 5 min and release of the clamp for another 5 min for a 3 cycles. IR was induced by 30 min ischemia followed by 10 min reperfusion. Four groups of male rats were used: Control, IPC, IR and IPC-IR. Vitamin E, an endogenous antioxidant and as an index of LP, was measured by HPLC and UV detection in renal venous plasma and tissue. Renal function was assessed by serum creatinine and BUN levels. Renal damage was assessed in sections stained with Haematoxylin and Eosin. RESULTS: In the IR group, there was a significant decrease in vitamin E in plasma and tissue compared to a control group (p,0.05). In the IPC-IR group, vitamin E concentration was significantly higher than in the IR group (p,0.01). The results showed that 30 min ischemia in the IR group significantly (p,0.05) reduced renal function demonstrated by an increase in serum creatinine levels as compared with the control group. These results in the IPC group also showed a significant difference with the IR group but no significant difference in serum BUN and creatinine between IR and IPC-IR group were detected. Histological evaluation showed no structural damage in the IPC group and an improvement in the IPC-IR group compared to IR alone. CONCLUSIONS: In this study, IPC preserved vitamin E levels, but it could not markedly improve renal function in the early phase (1–2 h) of reperfusion. IPC may be a useful method for antioxidant preservation in organ transplantation

    Processo Coletivo de reformulação curricular do BCC-IME-USP

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    A última reformulação na grade do Bacharelado em Ciência da Computação (BCC) do IME-USP deu-se em 1998. Há cinco anos um grupo de alunos, ex-alunos e professores do BCC iniciou um estudo com o objetivo de propor atualizações para a grade curricular do curso. Entre as principais mudanças propostas por este grupo estão a criação de trilhas e o aumento de número de disciplinas optativas eletivas, permitindo, inclusive, que os alunos cursem mais disciplinas de outras áreas e mesmo de outras universidades. Neste texto apresentamos o processo de mudança da grade, a nova grade curricular, bem como as diferenças entre as grades curriculares antiga, anterior e nova. A grade curricular entrou em vigor no ano de 2016. É importante observar que o processo contou fortemente com a participação de alunos e ex-alunos. Um efeito colateral positivo dessa participação é o aumento do envolvimento dos alunos do curso, que pode ser observado pela criação de diversos grupos de atividades extracurriculares por ações espontâneas.The last curriculum reform of the undergraduate degree Program in Computer Science (BCC) of the IME-USP took place in 1998. Six years ago, a group of BCC students, alumni, and professors began a study aiming to propose updates to the BCC curriculum. Among the main changes proposed by this group are the creation of tracks and the increase in the number of elective courses, allowing students to attend more courses from other areas and even from other universities. In this paper we present the update process of the curriculum, the new curriculum, as well as the differences between old, previous and new curricula. The new curriculum became valid in 2016. It is important to note that the process relied on the participation of students and former students. A positive side effect of this participation is the increase of the students’ involvement in the Program, which can be observed by the spontaneous creation of various extracurricular activities group

    IRES-Mediated Translation of Utrophin A Is Enhanced by Glucocorticoid Treatment in Skeletal Muscle Cells

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    Glucocorticoids are currently the only drug treatment recognized to benefit Duchenne muscular dystrophy (DMD) patients. The nature of the mechanisms underlying the beneficial effects remains incompletely understood but may involve an increase in the expression of utrophin. Here, we show that treatment of myotubes with 6α−methylprednisolone-21 sodium succinate (PDN) results in enhanced expression of utrophin A without concomitant increases in mRNA levels thereby suggesting that translational regulation contributes to the increase. In agreement with this, we show that PDN treatment of cells transfected with monocistronic reporter constructs harbouring the utrophin A 5′UTR, causes an increase in reporter protein expression while leaving levels of reporter mRNAs unchanged. Using bicistronic reporter assays, we further demonstrate that PDN enhances activity of an Internal Ribosome Entry Site (IRES) located within the utrophin A 5′UTR. Analysis of polysomes demonstrate that PDN causes an overall reduction in polysome-associated mRNAs indicating that global translation rates are depressed under these conditions. Importantly, PDN causes an increase in the polysome association of endogenous utrophin A mRNAs and reporter mRNAs harbouring the utrophin A 5′UTR. Additional experiments identified a distinct region within the utrophin A 5′UTR that contains the inducible IRES activity. Together, these studies demonstrate that a translational regulatory mechanism involving increased IRES activation mediates, at least partially, the enhanced expression of utrophin A in muscle cells treated with glucocorticoids. Targeting the utrophin A IRES may thus offer an important and novel therapeutic avenue for developing drugs appropriate for DMD patients
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