34 research outputs found

    Effects of intrauterine food restriction and long-term dietary supplementation with L-arginine on age-related changes in renal function and structure of rats

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    We have previously demonstrated that restricting intrauterine food by 50% in 3-mo-old rats produced lower nephron numbers and early-onset hypertension, the latter being normalized by L-arginine administration. in 18-mo-old rats, such restriction increased glomerulosclerosis. in this study, we expanded our investigation, evaluating functional, morphologic, and immunohistochemical parameters in intrauterine-food-restricted 18-mo-old rats, either receiving L-arginine (RA18) or not (R18). Age-matched, non-food-restricted controls were assigned to similar groups with L-arginine (CA18) and without (C18). After weaning, L-arginine was given daily for 17 mo. No functional or morphologic changes were observed in C IS rats. the R18 rats developed early-onset hypertension, which persisted throughout the observation period, as well its significant proteinuria from 12 mo on. in RA18 rats, L-arginine decreased both blood pressure levels and proteinuria, and glomerular diameter was si,significantly smaller than in R18 rats (115.63 +/- 2.2 versus 134.8 +/- 1.0 mu m, p < 0.05). However, in RA18 rats, glomerular filtration rate remained depressed. Although L-arginine prevented glomerulosclerosis (R18 = 14%, RA18 = 4%; p < 0.05), glomerular expression of fibronectin and desmin was still greater in RA18 rats than in controls. Our data show that, although L-arginine prevented hypertension and proteinuria, glomerular injury still occurred, suggesting that intrauterine food restriction may be one of the leading causes of impaired renal function in adult life.Universidade Federal de São Paulo, Dept Physiol, EPM, Dept Physiol, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Physiol, EPM, Dept Morphol,Embrol Div, BR-04023900 São Paulo, BrazilUniv São Paulo, Ribeirao Preto Sch Med, Dept Physiol & Biophys, Brookline, MA 02146 USAUniversidade Federal de São Paulo, Dept Physiol, EPM, Dept Physiol, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Physiol, EPM, Dept Morphol,Embrol Div, BR-04023900 São Paulo, BrazilWeb of Scienc

    The effects of temperature variation treatments on embryonic development: a mouse study

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    Since the development of ART, embryos have been cultured at 37 °C in an attempt to mimic the in vivo conditions and the average body temperature of an adult. However, a gradient of temperatures within the reproductive tract has been demonstrated in humans and several other mammalian species. Therefore, the aim of this study was to evaluate the effects of temperature variation treatments on mouse embryo quality through morphokinetic events, blastocyst morphology, the relative gene expression of Igf2, Bax, Bcl2 and Apaf1 and the metabolomics of individual culture media. Study groups consisted of 2 circadian treatments, T1 with embryos being cultured at 37 °C during the day and 35.5 °C during the night, T2 with 38.5 °C during the day and 37 °C during the night and a control group with constant 37 °C. Our main findings are that the lower-temperature group (T1) showed a consistent negative effect on mouse embryo development with “slow” cleaving embryos, poor-quality blastocysts, a higher expression of the apoptotic gene Apaf1, and a significantly different set of amino acids representing a more stressed metabolism. On the other hand, our higher-temperature group (T2) showed similar results to the control group, with no adverse effects on blastocyst viability

    Citalopram reduces aggregation of ATXN3 in a YAC transgenic mouse model of Machado-Joseph disease

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    Machado-Joseph disease, also known as spinocerebellar ataxia type 3, is a fatal polyglutamine disease with no disease-modifying treatment. The selective serotonin reuptake inhibitor citalopram was shown in nematode and mouse models to be a compelling repurposing candidate for Machado-Joseph disease therapeutics. We sought to confirm the efficacy of citalopram to decrease ATXN3 aggregation in an unrelated mouse model of Machado-Joseph disease. Four-week-old YACMJD84.2 mice and non-transgenic littermates were given citalopram 8 mg/kg in drinking water or water for 10 weeks. At the end of treatment, brains were collected for biochemical and pathological analyses. Brains of citalopram-treated YACMJD84.2 mice showed an approximate 50% decrease in the percentage of cells containing ATXN3-positive inclusions in the substantia nigra and three examined brainstem nuclei compared to controls. No differences in ATXN3 inclusion load were observed in deep cerebellar nuclei of mice. Citalopram effect on ATXN3 aggregate burden was corroborated by immunoblotting analysis. While lysates from the brainstem and cervical spinal cord of citalopram-treated mice showed a decrease in all soluble forms of ATXN3 and a trend toward reduction of insoluble ATXN3, no differences in ATXN3 levels were found between cerebella of citalopram-treated and vehicle-treated mice. Citalopram treatment altered levels of select components of the cellular protein homeostatic machinery that may be expected to enhance the capacity to refold and/or degrade mutant ATXN3. The results here obtained in a second independent mouse model of Machado-Joseph disease further support citalopram as a potential drug to be repurposed for this fatal disorder.This work was funded by Becky Babcox Research Fund/pilot research award G015617, University of Michigan to M.C.C. and NINDS/NIH R01NS038712 to H.L.P. The work performed at the University of Minho was funded by the European Regional Development Funds (FEDER), through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT), under the scope of the project POCI-01-0145-FEDER-007038. This article was developed under the scope of the project NORTE-01-0145-FEDER-000013, supported by the Northern Portugal Regional Operational Program (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the FEDER. This work was also supported by FCT and COMPETE through the projects [PTDC/SAU-GMG/112617/2009] (to P.M.) and [EXPL/BIM-MEC/ 0239/2012] (to A.T.C.); by FCT through the project [POCI-01-0145- FEDER-016818 (PTDC/NEU-NMC/3648/2014)] (to P.M.); by National Ataxia Foundation (to P.M. and to A.T.C.); and by Ataxia UK (to P.M.). S.D.S. and A.T.C. were supported by fellowships from FCT, SFRH/BD/ 78388/2011 and SFRH/BPD/102317/2014, respectively. FCT fellowships are co-financed by POPH, QREN, Governo da República Portuguesa and EU/FSE

    Understanding the clinical spectrum of complicated Plasmodium vivax malaria: a systematic review on the contributions of the Brazilian literature

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    The resurgence of the malaria eradication agenda and the increasing number of severe manifestation reports has contributed to a renewed interested in the Plasmodium vivax infection. It is the most geographically widespread parasite causing human malaria, with around 2.85 billion people living under risk of infection. The Brazilian Amazon region reports more than 50% of the malaria cases in Latin America and since 1990 there is a marked predominance of this species, responsible for 85% of cases in 2009. However, only a few complicated cases of P. vivax have been reported from this region. A systematic review of the Brazilian indexed and non-indexed literature on complicated cases of vivax malaria was performed including published articles, masters' dissertations, doctoral theses and national congresses' abstracts. The following information was retrieved: patient characteristics (demographic, presence of co-morbidities and, whenever possible, associated genetic disorders); description of each major clinical manifestation. As a result, 27 articles, 28 abstracts from scientific events' annals and 13 theses/dissertations were found, only after 1987. Most of the reported information was described in small case series and case reports of patients from all the Amazonian states, and also in travellers from Brazilian non-endemic areas. The more relevant clinical complications were anaemia, thrombocytopaenia, jaundice and acute respiratory distress syndrome, present in all age groups, in addition to other more rare clinical pictures. Complications in pregnant women were also reported. Acute and chronic co-morbidities were frequent, however death was occasional. Clinical atypical cases of malaria are more frequent than published in the indexed literature, probably due to a publication bias. In the Brazilian Amazon (considered to be a low to moderate intensity area of transmission), clinical data are in accordance with the recent findings of severity described in diverse P. vivax endemic areas (especially anaemia in Southeast Asia), however in this region both children and adults are affected. Finally, gaps of knowledge and areas for future research are opportunely pointed out

    Antisense Oligonucleotide-Mediated Removal of the Polyglutamine Repeat in Spinocerebellar Ataxia Type 3 Mice

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    Spinocerebellar ataxia type 3 (SCA3) is a currently incurable neurodegenerative disorder caused by a CAG triplet expansion in exon 10 of the ATXN3 gene. The resultant expanded polyglutamine stretch in the mutant ataxin-3 protein causes a gain of toxic function, which eventually leads to neurodegeneration. One important function of ataxin-3 is its involvement in the proteasomal protein degradation pathway, and long-term downregulation of the protein may therefore not be desirable. In the current study, we made use of antisense oligonucleotides to mask predicted exonic splicing signals, resulting in exon 10 skipping from ATXN3 pre-mRNA. This led to formation of a truncated ataxin-3 protein lacking the toxic polyglutamine expansion, but retaining its ubiquitin binding and cleavage function. Repeated intracerebroventricular injections of the antisense oligonucleotides in a SCA3 mouse model led to exon skipping and formation of the modified ataxin-3 protein throughout the mouse brain. Exon skipping was long lasting, with the modified protein being detectable for at least 2.5 months after antisense oligonucleotide injection. A reduction in insoluble ataxin-3 and nuclear accumulation was observed following antisense oligonucleotide treatment, indicating a beneficial effect on pathogenicity. Together, these data suggest that exon 10 skipping is a promising therapeutic approach for SCA3. Keywords: antisense oligonucleotides, spinocerebellar ataxia type 3, exon skipping, ataxin-3, ATXN3, SCA3, Machado-Joseph diseas
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