Adenylyl cyclase types I and VI but not II and V are selectively inhibited by nitric oxide

Adenylyl cyclase (AC) isoforms catalyze the synthesis of 3′,5′-cyclic AMP from ATP. These isoforms are critically involved in the regulation of gene transcription, metabolism, and ion channel activity among others. Nitric oxide (NO) is a gaseous product whose synthesis from L-arginine is catalyzed by the enzyme NO synthase. It has been well established that NO activates the enzyme guanylyl cyclase, but little has been reported on the effects of NO on other important second messengers, such as AC. In the present study, the effects of sodium nitroprusside (SNP), a nitric oxide-releasing compound, on COS-7 cells transfected with plasmids containing AC types I, II, V and VI were evaluated. Total inhibition (∼98.5%) of cAMP production was observed in COS-7 cells transfected with the AC I isoform and previously treated with SNP (10 mM) for 30 min, when stimulated with ionomycin. A high inhibition (∼76%) of cAMP production was also observed in COS-7 cells transfected with the AC VI isoform and previously treated with SNP (10 mM) for 30 min, when stimulated with forskolin. No effect on cAMP production was observed in cells transfected with AC isoforms II and V.Fil: Goldstein Raij, Jorge. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Fisiopatogenia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Ibarra, Cristina Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Fisiopatogenia; ArgentinaFil: Silberstein, Claudia Marcela. Universidad de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Fisiopatogenia; Argentin

A glucosylceramide synthase inhibitor prevents the cytotoxic effects of Shiga toxin-2 on human renal tubular epithelial cells

Shiga toxin-2 binds to the globotriaosyl-ceramide receptor on the plasma membrane of target cells. The highlevel expression of this receptor in renal epithelial cells may account, at least in part, for acute renal failure observed inchildren with hemolytic uremic syndrome. The cytotoxic effect of Shiga toxin-2 was assayed on primary cultures of humanrenal tubular epithelial cells treated with a new specific inhibitor of glucosylceramide synthase (C-9), the ratelimitingfirst step in the glycosphingolipid biosynthetic pathway. The treatment of the cells with 1-5 M C-9 for at least24 h significantly neutralized the action of 1 ng/ml Shiga toxin-2 on cell viability. The expression levels of globotriaosylceramidesignificantly decreased when cells were incubated with 1 M C-9 for 48 h. We propose here that prevention ofglobotriaosyl-ceramide synthesis by the C-9 could be a novel substrate inhibition therapy to neutralize Shiga toxin-2 actionin renal epithelial cells.Fil: Silberstein, Claudia Marcela. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Fisiopatogenia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; ArgentinaFil: Copeland, Diane P. No especifíca;Fil: Chiang, Wei Lien. No especifíca;Fil: Repetto, Horacio A.. Hospital Nacional Profesor Alejandro Posadas; ArgentinaFil: Ibarra, Cristina Adriana. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Fisiopatogenia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentin

Role of the Shiga toxin in the Hemolytic Uremic Syndrome

En los últimos años, las infecciones por Escherichia coli productor de toxina Shiga (STEC) y el desarrollo del Síndrome Urémico Hemolítico (SUH) han cobrado tal relevancia desde el punto de vista clínico y como problema de salud pública, que se considera uno de los patógenos emergentes más importantes de infecciones transmitidas por alimentos. Las infecciones por STEC pueden manifestarse dentro de un amplio espectro clínico, tales como infecciones asintomáticas intestinales, diarrea acuosa, diarrea sanguinolenta (colitis hemorrágica) y complicaciones sistémicas conocidas con el nombre de SUH. En Argentina, el SUH es la principal causa pediátrica de insuficiencia renal aguda y la segunda de insuficiencia renal crónica. Hasta el presente no existe un tratamiento específico para tratar las infecciones por STEC y disminuir la progresión del SUH. Los mecanismos por los cuales la toxina Shiga (Stx) induce SUH pueden ayudar a encontrar nuevas estrategias para impedir o mejorar el pronóstico del SUH. En este artículo se describen recientes progresos que contribuyen a entender el papel de Stx en la patogénesis del SUH y nuevas estrategias usadas para prevenir el pasaje de la toxina a la circulación sistémica durante la fase diarreica o luego del establecimiento del SUH.In the last years, infection associated with Shiga toxin-producing Escherichia coli (STEC) and subsequent Hemolitic-Uremic Syndrome (HUS) became relevant as a public health since it was considered as one of the most important emergent patogen present in the food contaminated by cattle feces. STEC infection may be asymptomatic or begins with a watery diarrhea that may or may not progress to bloody diarrhea (hemorrhagic colitis) and HUS. In Argentina, HUS is the most common pediatric cause of acute renal insufficiency and the second cause of chronic renal failure. Up to now, STEC infection lacks of known effective treatment strategies that diminish risk of progression to HUS. The mechanisms by which Shiga toxin (Stx) induce HUS may help to find strategies to prevent or ameliorate HUS. In this article, recent progress that has contributed to understanding the disease pathogenesis of STEC is reviewed. New strategies to prevent further uptake of Shiga from the gut, either during the diarrheal phase or once HUS has developed are discussed.Fil: Pistone Creydt, Virginia. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Fisiopatogenia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Nuñez, Pablo. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Fisiopatogenia; ArgentinaFil: Boccoli, Javier. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Fisiopatogenia; ArgentinaFil: Silberstein, Claudia Marcela. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Fisiopatogenia; ArgentinaFil: Zotta, Elsa. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Fisiopatogenia; ArgentinaFil: Goldstein, Jorge. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Fisiopatogenia; ArgentinaFil: Ibarra, Cristina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas. Laboratorio de Fisiopatogenia; Argentin

Recent transmission clustering of HIV-1 C and CRF17_BF strains characterized by NNRTI-related mutations among newly diagnosed men in central Italy

Increased evidence of relevant HIV-1 epidemic transmission in European countries is being reported, with an increased circulation of non-B-subtypes. Here, we present two recent HIV-1 non-B transmission clusters characterized by NNRTI-related amino-acidic mutations among newly diagnosed HIV-1 infected men, living in Rome (Central-Italy)

Obtaining new information on hemolytic uremic syndrome by text mining

El síndroem urémico hemolítico está caracterizado por microangiopatía trombótica, anemia hemolítica, trombocitopenia e insuficiencia renal aguda. Puede causar desde secuelas permanentes hasta muerte, principalmente en niños. En este trabajo, utilizando minería de textos (MT), se analizó el texto explícito e implícito de 16 192 artículos científicos originales sobre SUH indexados en la base de datos de Europe PMC. Los objetivos fueron examinar comportamientos, realizar seguimiento de tendencias, hacer predicciones y cruzar datos con otras fuentes de información. Para el análisis se utilizaron –entre otras herramientas infor-máticas– flujos de trabajo (FT) especialmente desarrollados en la plataforma KNIME. La MT sobre las palabras de los resúmenes de las publicaciones permitió: detectar asociaciones no descritas entre eventos relacionados con SUH; extraer información subyacente; hacer agrupamientos temáticos mediante algoritmos no supervisados; realizar predicciones sobre el curso de las investigaciones asociadas al tema. Tanto el abordaje como los FT desarrollados para realizar Ciencia de Datos sobre SUH pueden aplicarse a otros temas biomédicos y a otras bases de datos científicos, permitiendo analizar aspectos relevantes en el campo de la salud humana para me-jorar la investigación, la prevención y el tratamiento de múltiples enfermedades.Hemolytic uremic syndrome (HUS) is characterized by thrombotic microangiopathy, hemolytic anemia, thrombocytopenia and acute renal failure. It can cause from permanent sequelae to death, mainly in children. In this work, using text mining (TM), we analyzed the explicit and implicit text of 16 192 original scientific articles on HUS indexed in the Europe PMC database. The objectives were to examine behaviors, track trends, and make predictions and cross-check data with other sources of information. For the analysis we used –among other computational tools– specially developed workflows (WF) in the KNIME platform. The TM on the words of the abstracts of the publications made it possible to: detect undescribed associations between events related to HUS; extract underlying information; make thematic clustering using unsupervised algorithms; make forecasting about the course of research associated with the topic. Both the approach and the WFs developed to perform Data Science on HUS can be applied to other biomedical topics and other scientific databases, making it possible to analyze relevant aspects in the field of human health to improve research, prevention and treatment of multiples diseases.Fil: Dorr, Ricardo Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Silberstein, Claudia Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Ibarra, Cristina Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Toriano, Roxana Mabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; Argentin

Obtaining new information on hemolytic uremic syndrome by text mining

El síndroem urémico hemolítico está caracterizado por microangiopatía trombótica, anemia hemolítica, trombocitopenia e insuficiencia renal aguda. Puede causar desde secuelas permanentes hasta muerte, principalmente en niños. En este trabajo, utilizando minería de textos (MT), se analizó el texto explícito e implícito de 16 192 artículos científicos originales sobre SUH indexados en la base de datos de Europe PMC. Los objetivos fueron examinar comportamientos, realizar seguimiento de tendencias, hacer predicciones y cruzar datos con otras fuentes de información. Para el análisis se utilizaron –entre otras herramientas infor-máticas– flujos de trabajo (FT) especialmente desarrollados en la plataforma KNIME. La MT sobre las palabras de los resúmenes de las publicaciones permitió: detectar asociaciones no descritas entre eventos relacionados con SUH; extraer información subyacente; hacer agrupamientos temáticos mediante algoritmos no supervisados; realizar predicciones sobre el curso de las investigaciones asociadas al tema. Tanto el abordaje como los FT desarrollados para realizar Ciencia de Datos sobre SUH pueden aplicarse a otros temas biomédicos y a otras bases de datos científicos, permitiendo analizar aspectos relevantes en el campo de la salud humana para me-jorar la investigación, la prevención y el tratamiento de múltiples enfermedades.Hemolytic uremic syndrome (HUS) is characterized by thrombotic microangiopathy, hemolytic anemia, thrombocytopenia and acute renal failure. It can cause from permanent sequelae to death, mainly in children. In this work, using text mining (TM), we analyzed the explicit and implicit text of 16 192 original scientific articles on HUS indexed in the Europe PMC database. The objectives were to examine behaviors, track trends, and make predictions and cross-check data with other sources of information. For the analysis we used –among other computational tools– specially developed workflows (WF) in the KNIME platform. The TM on the words of the abstracts of the publications made it possible to: detect undescribed associations between events related to HUS; extract underlying information; make thematic clustering using unsupervised algorithms; make forecasting about the course of research associated with the topic. Both the approach and the WFs developed to perform Data Science on HUS can be applied to other biomedical topics and other scientific databases, making it possible to analyze relevant aspects in the field of human health to improve research, prevention and treatment of multiples diseases.Fil: Dorr, Ricardo Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Silberstein, Claudia Marcela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Ibarra, Cristina Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; ArgentinaFil: Toriano, Roxana Mabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; Argentin

Impact of analytical treatment interruption on burden and diversification of HIV peripheral reservoir: a pilot study

Background: If analytical antiretroviral-treatment (ART) interruption (ATI) might significantly impact quantitative or qualitative peripheral-total HIV-DNA is still debated. Methods: Six chronically HIV-1 infected patients enrolled in APACHE-study were analysed for peripheral-total HIV-DNA and residual viremia, major-resistance-mutations (MRMs) and C2-V3-C3 evolution at pre-ATI (T1), during ATI (T2) and at achievement of virological success after ART-resumption (post-ATI, T3). These data were obtained at three comparable time-points in five chronically HIV-1 infected patients on suppressive ART for ≥1 year, enrolled in MODAt-study. Results: At T1, APACHE and MODAt individuals had similar peripheral-total HIV-DNA and residual viremia (p = 0.792 and 0.662, respectively), and no significant changes for these parameters were observed between T1 and T3 in both groups. At T1, 4/6 APACHE and 2/5 MODAt carried HIV-DNA MRMs. MRMs disappeared at T3 in 3/4 APACHE. All disappearing MRMs were characterized by T1 intra-patient prevalence <80%, and mainly occurred in APOBEC3-related sites. All MRMs persisted over-time in the 2 MODAt. C2-V3-C3 genetic-distance significantly changed from T1 to T3 in APACHE individuals (+0.36[0.11-0.41], p = 0.04), while no significant changes were found in MODAt. Accordingly, maximum likelihood trees (bootstrap > 70%) and genealogical sorting indices (GSI > 0.50 with p-value < 0.05) showed that T1 C2-V3-C3 DNA sequences were distinct from T2 and T3 viruses in 4/6 APACHE. Virus populations at all three time-points were highly interspersed in MODAt. Conclusions: This pilot study indicates that short ATI does not alter peripheral-total HIV-DNA burden and residual viremia, but in some cases could cause a genetic diversification of peripheral viral reservoir in term of both MRMs rearrangement and viral evolution

External quality assessment of HIV-1 DNA quantification assays used in the clinical setting in Italy

none18no: Total cell-associated HIV-1 DNA is a surrogate marker of the HIV-1 reservoir, however, certified systems for its quantification are not available. The Italian HIV DNA Network was launched to validate HIV-1 DNA quantification methods in use at University and Hospital labs. A quality control panel including HIV-1 DNA standards, reconstructed blood samples (RBSs) and DNA from different HIV-1 subtypes was blindly tested by 12 participating labs by quantitative real-time PCR (n = 6), droplet digital PCR (n = 3) or both (n = 3). The median 95% hit rate was 4.6 (3.7-5.5) copies per test and linearity in the tested range was excellent (R2 = 1.000 [1.000-1.000]). The median values obtained across labs were 3,370 (2,287-4,245), 445 (299-498), 59 (40-81) and 7 (6-11) HIV-1 DNA copies, for the 3,584, 448, 56 and 7-copy standards, respectively. With RBSs, measured values were within twofold with respect to the median in two thirds of cases. HIV-1 subtypes were missed (CRF01_AE by 3 labs) or underestimated by > 1 log (subtypes A, C, D, F by one lab; CRF01_AE by one lab; CRF02_AG by one lab). The overall performance was excellent with HIV-1 DNA standards, however detection of different HIV-1 subtypes must be improved.openVicenti, Ilaria; Dragoni, Filippo; Giannini, Alessia; Casabianca, Anna; Lombardi, Francesca; Di Sante, Laura; Turriziani, Ombretta; Racca, Sara; Paolucci, Stefania; Lai, Alessia; Bon, Isabella; Abbate, Isabella; Rozera, Gabriella; Belmonti, Simone; Scutari, Rossana; Alteri, Claudia; Saladini, Francesco; Zazzi, MaurizioVicenti, Ilaria; Dragoni, Filippo; Giannini, Alessia; Casabianca, Anna; Lombardi, Francesca; Di Sante, Laura; Turriziani, Ombretta; Racca, Sara; Paolucci, Stefania; Lai, Alessia; Bon, Isabella; Abbate, Isabella; Rozera, Gabriella; Belmonti, Simone; Scutari, Rossana; Alteri, Claudia; Saladini, Francesco; Zazzi, Maurizi