40 research outputs found

    In vitro and in vivo herpetic vector-mediated gene transfer in the pituitary gland: Impact on hormone secretion

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    Objective: Herpes simplex virus type 1 (HSV-1)-derived vectors are known to be effective tools to deliver transgenes into normal and neoplastic anterior pituitary (AP) cells in vitro. Our objective was to assess the in vitro and in vivo effects of tsK/β-gal, a temperature-sensitive HSV-1-derived vector harbouring the E. coli β-galactosidase gene, on AP hormone secretion as well as on transgene expression in rat AP tumours (hyperplastic prolactinomas). Design: The impact of vector infection on prolactin (PRL) and GH release was determined in vitro in normal and hyperplastic (lactotrophic) dispersed AP cells exposed for 24 h to tsK/β-gal as well as in vivo in ectopic AP grafts. In some oestrogen-induced prolactinoma-carrying rats, vector suspension was stereotaxically injected into the glands to assess transgene expression in vivo. Methods: GH and PRL release was measured by specific RIAs. In vivo transgene expression was assessed by immunohistochemistry for β-galactosidase and enzymohistochemistry (5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside). Ectopic pituitary grafts and stereotaxic surgery were performed following standard procedures. Results: At a multiplicity of infection of 0.5, the vector induced a 30 and 22% fall in PRL and GH release respectively in normal AP cells, whereas the corresponding hormone release inhibition for hyperplastic AP cells was 41 and 33% for PRL and GH respectively. In ectopic pituitary grafts, the effect of vector infection on hormone secretion was assessed by measuring serum PRL levels in the host rats every 5 days for 4 weeks post-grafting. In the pituitary-grafted rats that received the viral vector, serum PRL failed to increase to the levels achieved in control-grafted animals. Finally, pituitary tumours stereotaxically injected with tsK/β-gal showed widespread expression of the β-galactosidase transgene around the injection areas. Conclusions: The results reported here have implications for basic studies using gene transfer to pituitary gland as well as potential gene therapy approaches to pituitary diseases.Instituto de Investigaciones Bioquímicas de La PlataInstituto de Biotecnologia y Biologia MolecularInstituto Multidisciplinario de Biología Celula

    In vitro and in vivo herpetic vector-mediated gene transfer in the pituitary gland: Impact on hormone secretion

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    Objective: Herpes simplex virus type 1 (HSV-1)-derived vectors are known to be effective tools to deliver transgenes into normal and neoplastic anterior pituitary (AP) cells in vitro. Our objective was to assess the in vitro and in vivo effects of tsK/β-gal, a temperature-sensitive HSV-1-derived vector harbouring the E. coli β-galactosidase gene, on AP hormone secretion as well as on transgene expression in rat AP tumours (hyperplastic prolactinomas). Design: The impact of vector infection on prolactin (PRL) and GH release was determined in vitro in normal and hyperplastic (lactotrophic) dispersed AP cells exposed for 24 h to tsK/β-gal as well as in vivo in ectopic AP grafts. In some oestrogen-induced prolactinoma-carrying rats, vector suspension was stereotaxically injected into the glands to assess transgene expression in vivo. Methods: GH and PRL release was measured by specific RIAs. In vivo transgene expression was assessed by immunohistochemistry for β-galactosidase and enzymohistochemistry (5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside). Ectopic pituitary grafts and stereotaxic surgery were performed following standard procedures. Results: At a multiplicity of infection of 0.5, the vector induced a 30 and 22% fall in PRL and GH release respectively in normal AP cells, whereas the corresponding hormone release inhibition for hyperplastic AP cells was 41 and 33% for PRL and GH respectively. In ectopic pituitary grafts, the effect of vector infection on hormone secretion was assessed by measuring serum PRL levels in the host rats every 5 days for 4 weeks post-grafting. In the pituitary-grafted rats that received the viral vector, serum PRL failed to increase to the levels achieved in control-grafted animals. Finally, pituitary tumours stereotaxically injected with tsK/β-gal showed widespread expression of the β-galactosidase transgene around the injection areas. Conclusions: The results reported here have implications for basic studies using gene transfer to pituitary gland as well as potential gene therapy approaches to pituitary diseases.Instituto de Investigaciones Bioquímicas de La PlataInstituto de Biotecnologia y Biologia MolecularInstituto Multidisciplinario de Biología Celula

    Insulin-like growth factor-I gene delivery to astrocytes reduces their inflammatory response to lipopolysaccharide

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    <p>Abstract</p> <p>Background</p> <p>Insulin-like growth factor-I (IGF-I) exerts neuroprotective actions in the central nervous system that are mediated at least in part by control of activation of astrocytes. In this study we have assessed the efficacy of exogenous IGF-I and IGF-I gene therapy in reducing the inflammatory response of astrocytes from cerebral cortex.</p> <p>Methods</p> <p>An adenoviral vector harboring the rat IGF-I gene and a control adenoviral vector harboring a hybrid gene encoding the herpes simplex virus type 1 thymidine kinase fused to <it>Aequorea victoria </it>enhanced green fluorescent protein were used in this study. Primary astrocytes from mice cerebral cortex were incubated for 24 h or 72 h with vehicle, IGF-I, the IGF-I adenoviral vector, or control vector; and exposed to bacterial lipopolysaccharide to induce an inflammatory response. IGF-I levels were measured by radioimmunoassay. Levels of interleukin 6, tumor necrosis factor-α, interleukin-1β and toll-like receptor 4 mRNA were assessed by quantitative real-time polymerase chain reaction. Levels of IGF-I receptor and IGF binding proteins 2 and 3 were assessed by western blotting. The subcellular distribution of nuclear factor κB (p65) was assessed by immunocytochemistry. Statistical significance was assessed by one way analysis of variance followed by the Bonferroni pot hoc test.</p> <p>Results</p> <p>IGF-I gene therapy increased IGF-I levels without affecting IGF-I receptors or IGF binding proteins. Exogenous IGF-I, and IGF-I gene therapy, decreased expression of toll-like receptor 4 and counteracted the lipopolysaccharide-induced inflammatory response of astrocytes. In addition, IGF-I gene therapy decreased lipopolysaccharide-induced translocation of nuclear factor κB (p65) to the cell nucleus.</p> <p>Conclusion</p> <p>These findings demonstrate efficacy of exogenous IGF-I and of IGF-I gene therapy in reducing the inflammatory response of astrocytes. IGF-I gene therapy may represent a new approach to reduce inflammatory reactions in glial cells.</p

    Cambios morfológicos en la población somatotropa inducidos por terapia génica neonatal con el vector RAd-FTS en ratones nude

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    Se ha detectado un eje bidireccional timo-pituitario, hallándose receptores de GH en las células epiteliales tímicas. La GH estimularía la secreción de timulina, mientras que los niveles bajos de timulina circulante en período prenatal inducirían hipopituitarismo. El presente estudio tiene por objetivo: implementar una terapia génica mediante el vector adenoviral RAd-FTS en ratones inmunodeficientes, con el fin de prevenir cambios en la población somatotropa

    In vitro and in vivo herpetic vector-mediated gene transfer in the pituitary gland: Impact on hormone secretion

    Get PDF
    Objective: Herpes simplex virus type 1 (HSV-1)-derived vectors are known to be effective tools to deliver transgenes into normal and neoplastic anterior pituitary (AP) cells in vitro. Our objective was to assess the in vitro and in vivo effects of tsK/β-gal, a temperature-sensitive HSV-1-derived vector harbouring the E. coli β-galactosidase gene, on AP hormone secretion as well as on transgene expression in rat AP tumours (hyperplastic prolactinomas). Design: The impact of vector infection on prolactin (PRL) and GH release was determined in vitro in normal and hyperplastic (lactotrophic) dispersed AP cells exposed for 24 h to tsK/β-gal as well as in vivo in ectopic AP grafts. In some oestrogen-induced prolactinoma-carrying rats, vector suspension was stereotaxically injected into the glands to assess transgene expression in vivo. Methods: GH and PRL release was measured by specific RIAs. In vivo transgene expression was assessed by immunohistochemistry for β-galactosidase and enzymohistochemistry (5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside). Ectopic pituitary grafts and stereotaxic surgery were performed following standard procedures. Results: At a multiplicity of infection of 0.5, the vector induced a 30 and 22% fall in PRL and GH release respectively in normal AP cells, whereas the corresponding hormone release inhibition for hyperplastic AP cells was 41 and 33% for PRL and GH respectively. In ectopic pituitary grafts, the effect of vector infection on hormone secretion was assessed by measuring serum PRL levels in the host rats every 5 days for 4 weeks post-grafting. In the pituitary-grafted rats that received the viral vector, serum PRL failed to increase to the levels achieved in control-grafted animals. Finally, pituitary tumours stereotaxically injected with tsK/β-gal showed widespread expression of the β-galactosidase transgene around the injection areas. Conclusions: The results reported here have implications for basic studies using gene transfer to pituitary gland as well as potential gene therapy approaches to pituitary diseases.Instituto de Investigaciones Bioquímicas de La PlataInstituto de Biotecnologia y Biologia MolecularInstituto Multidisciplinario de Biología Celula

    Insulin-like growth factor-I gene therapy reverses morphologic changes and reduces hyperprolactinemia in experimental rat prolactinomas

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    <p>Abstract</p> <p>Background</p> <p>The implementation of gene therapy for the treatment of pituitary tumors emerges as a promising complement to surgery and may have distinct advantages over radiotherapy for this type of tumors. Up to now, suicide gene therapy has been the main experimental approach explored to treat experimental pituitary tumors. In the present study we assessed the effectiveness of insulin-like growth factor I (IGF-I) gene therapy for the treatment of estrogen-induced prolactinomas in rats.</p> <p>Results</p> <p>Female Sprague Dawley rats were subcutaneously implanted with silastic capsules filled with 17-β estradiol (E<sub>2</sub>) in order to induce pituitary prolactinomas. Blood samples were taken at regular intervals in order to measure serum prolactin (PRL). As expected, serum PRL increased progressively and 23 days after implanting the E<sub>2 </sub>capsules (Experimental day 0), circulating PRL had undergone a 3–4 fold increase. On Experimental day 0 part of the E<sub>2</sub>-implanted animals received a bilateral intrapituitary injection of either an adenoviral vector expressing the gene for rat IGF-I (RAd-IGFI), or a vector (RAd-GFP) expressing the gene for green fluorescent protein (GFP). Seven days post vector injection all animals were sacrificed and their pituitaries morphometrically analyzed to evaluate changes in the lactotroph population. RAd-IGFI but not RAd-GFP, induced a significant fall in serum PRL. Furthermore, RAd-IGFI but not RAd-GFP significantly reversed the increase in lactotroph size (CS) and volume density (VD) induced by E<sub>2 </sub>treatment.</p> <p>Conclusion</p> <p>We conclude that IGF-I gene therapy constitutes a potentially useful intervention for the treatment of prolactinomas and that bioactive peptide gene delivery may open novel therapeutic avenues for the treatment of pituitary tumors.</p

    Regional research priorities in brain and nervous system disorders

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    The characteristics of neurological, psychiatric, developmental and substance-use disorders in low-and middle-income countries are unique and the burden that they have will be different from country to country. Many of the differences are explained by the wide variation in population demographics and size, poverty, conflict, culture, land area and quality, and genetics. Neurological, psychiatric, developmental and substance-use disorders that result from, or are worsened by, a lack of adequate nutrition and infectious disease still afflict much of sub-Saharan Africa, although disorders related to increasing longevity, such as stroke, are on the rise. In the Middle East and North Africa, major depressive disorders and post-traumatic stress disorder are a primary concern because of the conflict-ridden environment. Consanguinity is a serious concern that leads to the high prevalence of recessive disorders in the Middle East and North Africa and possibly other regions. The burden of these disorders in Latin American and Asian countries largely surrounds stroke and vascular disease, dementia and lifestyle factors that are influenced by genetics. Although much knowledge has been gained over the past 10 years, the epidemiology of the conditions in low-and middle-income countries still needs more research. Prevention and treatments could be better informed with more longitudinal studies of risk factors. Challenges and opportunities for ameliorating nervous-system disorders can benefit from both local and regional research collaborations. The lack of resources and infrastructure for health-care and related research, both in terms of personnel and equipment, along with the stigma associated with the physical or behavioural manifestations of some disorders have hampered progress in understanding the disease burden and improving brain health. Individual countries, and regions within countries, have specific needs in terms of research priorities.Fil: Ravindranath, Vijayalakshmi. Indian Institute of Science; IndiaFil: Dang, Hoang Minh. Vietnam National University; VietnamFil: Goya, Rodolfo Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Mansour, Hader. University of Pittsburgh; Estados Unidos. Mansoura University; EgiptoFil: Nimgaonkar, Vishwajit L.. University of Pittsburgh; Estados UnidosFil: Russell, Vivienne Ann. University of Cape Town; SudáfricaFil: Xin, Yu. Peking University; Chin

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

    Heterogeneity of circulating prolactin in the bitch

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    Different molecular forms of circulating prolactin (PRL) are known to occur in several species. As no such information was available in dogs, we assessed the molecular profile of circulating PRL in bitches. Pooled sera from covertly (CTRL) and overtly pseudopregnant (PSPT) diestrous bitches with high or low (>> 10 or << 10 ng\cdotmL1^{-1}, respectively) serum PRL (measured by ELISA) were analyzed by Sephadex G-100 and Concanavalin A-Sepharose column chromatography. Four serum PRL fractions were identified and termed big-big, big (>> 67 kDa), native (23 kDa) and fragmented (<< 20 kDa) PRL. The percentages of these fractions were roughly similar in CTRL and PSPT animals, irrespective of their serum PRL levels (higher in PSPT than in CTRL bitches). A large proportion of glycosylated PRL (between 69 and 100%) was also detected in these sera. We conclude that in dogs, circulating PRL occurs in multiple molecular forms, whose relative abundance is comparable in covertly and overtly pseudopregnant bitches.Hétérogénéité de la prolactine circulante chez la chienne. La prolactine (PRL) circulante se trouve, dans différentes espèces, sous plusieurs formes moléculaires. Compte tenu du fait qu'il n'existe pas d'information disponible chez le chien, nous avons décidé d'étudier le profil moléculaire de la PRL circulante chez cet animal. Nous avons utilisé des pools de sérums provenant de chiennes normales en diestrus (CTRL) ou pseudogestantes (PSPT), ayant des taux élevés ou bas de PRL (>> 10 ou << 10 ng\cdotmL1^{-1} respectivement; dosages effectués par Elisa). Les sérums ont été analysés sur colonne de Séphadex G-100 et par chromatographie d'affinité, sur colonne de Sépharose couplée à de la Concanavaline A. La chromatographie sur G-100 a identifié quatre fractions de PRL, qui ont été appelées big-big, big (PM << 67 kDa), native (23 kDa) et fragmentée (<< 20 kDa). Les pourcentages relatifs de ces fractions sont identiques chez les CTRL et les PSPT, quel que soit le taux, élevé ou bas, de PRL sérique (plus haut chez les animaux CTRL). De plus, une proportion importante de PRL sérique (69 à 100 %) est sous forme glycosylée. En conclusion, la PRL sérique se trouve, chez le chien, sous des formes moléculaires multiples, dont l'abondance relative est comparable chez la chienne normale et pseudogestante

    Racemized and Isomerized Proteins in Aging Rat Teeth and Eye Lens

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    The quantification of aspartic acid racemization in the proteins of nonmetabolically active tissues can be used as a measure of chronological aging in humans and other long-lived organisms. However, very few studies have been conducted in shorter-lived animals such as rodents, which are increasingly used as genetic and metabolic models of aging. An initial study had reported significant changes in the ratio of d- to l-aspartate in rat molars with age. Using a sensitive HPLC method for the determination of d- and l-aspartate from protein hydrolysates, we found no accumulation of d-aspartate in the molars of 17 rats that ranged in age from 2 to 44 months, and the amount of d-aspartate per molar did not correspond with molar eruption date as had been previously reported. However, developing an alternate approach, we found significant accumulation of isomerized aspartyl residues in eye lens proteins that are also formed by spontaneous degradation processes. In this study, we used the human protein l-isoaspartate/d-aspartate O-methyltransferase (PCMT1) as an analytical reagent in a sensitive and convenient procedure that could be used to rapidly examine multiple samples simultaneously. We found levels of isomerized aspartyl residues to be about 35 times higher in the lens extracts of 18-month-old rats versus 2-month-old rats, suggesting that isomerization may be an effective marker for biological aging in this range of ages. Importantly, we found that the accumulation appeared to plateau in rats of 18 months and older, indicating that potentially novel mechanisms for removing altered proteins may develop with age.Fil: Warmack, Rebeccah A.. University of California at Los Angeles; Estados UnidosFil: Mansilla, Eduardo. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaFil: Goya, Rodolfo Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata ; ArgentinaFil: Clarke, Steven G.. University of California at Los Angeles; Estados Unido
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