Expresion and release regulation of gonadotropin releasin hormone (GnRH): Glucorticoids like reproduction inhibitor

ABSTRACT: Gonadotropin releasing hormone (GnRH) plays a key role in regulation of the reproductive competence in vertebrates. This decapeptide produced by a few cells in the anterior and medial hypothalamus is released in a pulsatile manner onto the pituitary, where it induces the secretion of gonadotropins: follicle stimulating hormone (FSH) and luteinizing hormone (LH). Stress negatively affects reproductive competence in animals. However, the level of this inhibition and its molecular mechanisms are not completely understood. Recent evidence that glucocorticoids inhibit GnRH gene expression suggest that it could be one of the forms by which high glucocorticoid concentrations affect reproduction. This review presents the current knowledge about GnRH and its molecular structure, the ontogenesis and distribution of the cells that produce this hormone, new tools that facilitate the study of gene expression, synthesis and release of GnRH. The mechanisms of action of glucocorticoids are discussed as well as their negative regulation on the expression and release of GnRH and consequently on reproduction.RESUMEN: La hormona liberadora de gonadotropinas (GnRH) juega un papel central en la regulación de la competencia reproductiva en todos los vertebrados. Este decapéptido producido por unas cuantas células ubicadas en la parte anterior y media del hipotálamo es liberado en forma pulsátil hacia la hipófisis anterior, donde induce la liberación de las gonadotropinas: la hormona folículo-estimulan-te (FSH) y la hormona luteinizante (LH). El estrés es un factor que compromete la competencia reproductiva de los animales. Sin embargo, el nivel al cual ocurre esta inhibición y los mecanismos moleculares de esta acción aún no han sido enteramente dilucidados. Recientemente se han encontrado evidencias que involucran a los glucocorticoides como inhibidores de la expresión del gen de la GnRH, pudiendo ser ésta una de las formas en las cuales la reproducción se ve afectada por altas concentraciones de glucocorticoides. Esta revisión presenta el estado actual del conocimiento sobre la GnRH, su estructura molecular, el desarrollo y distribución de las células que la producen, las nuevas herramientas para el estudio de la regulación de su expresión, síntesis y liberación. Se discuten los mecanismos de acción de los glucocorticoides, y su aparente control negativo sobre la expresión y liberación de dicha hormona y por ende sobre la reproducción

Chlorpyrifos : a possible endocrine disrupter in dairy cattle

ABSTRACT: The use of pesticides for the control of those insects, fungi or plants that negatively affect or compete with animals or crops has allowed a remarkable increase in agricultural yield and cattle production. Nonetheless, the harmful effects of pesticides on human and environmental health have already been demonstrated and have become a major issue since the discovery of the role of pesticides as endocrine disrupters (ED). This name is given to substances that interfere with the synthesis, secretion, transport, union, action or elimination of natural hormones. The study of ED has received a great interest in the last two decades, not only because its consequences for public health through residues and contamination of food, but also because several pesticides have been related to reproductive problems in animals. The present review begins with a description of the current state of the use of insecticides (especially organophosphates) in farming production in Colombia, then, it examines up to date information regarding ED, their effects, and mechanisms discovered so far. It is evident the lack of information related to EDs in cattle, compared to the amount available on other species, especially wild animals and humans. Chlorpyrifos is an organophosphate insecticide, widely used in dairy cattle industry in Colombia. It has been reported to affect thyroid hormones and there is contradictory information regarding its effects upon estrogen. This review emphasizes the need to research the potential role of chlorpyrifos as an ED in the dairy region of the north of Antioquia, Colombia, to identify the possible relations between chlorpyrifos residues in milk and plasmatic levels of thyroid hormones and estrogens in dairy cows, as well as developing in vitro models for its study.RESUMEN: La presente revisión se inicia con una descripción del estado actual del uso de insecticidas en la producción agropecuaria, con énfasis en organofosforados, suministrando datos sobre la situación en Colombia. El artículo realiza un examen sobre información actualizada acerca del papel de los disruptores en general, sus acciones y los mecanismos de acción hasta ahora descubiertos Dentro de los organofosforados se destaca el Clorpirifos, pesticida del cual se conoce su acción como disruptor endocrino afectando principalmente las hormonas tiroideas, y con resultados contradictorios con respecto a los estrógenos; se deduce de la revisión, la escasa información disponible a nivel mundial sobre los DE en bovinos, al compararla con la que existe para otras especies, especialmente las silvestres. Se concluye con la necesidad de ahondar en la búsqueda del posible papel del Clorpirifos como disruptor hormonal en ganado en la región lechera del Norte de Antioquia, Colombia, teniendo en cuenta el volumen y las prácticas de utilización del mismo, identificando las relaciones potenciales entre sus niveles residuales en leche y los niveles plasmáticos de las hormonas tiroideas y los estrógenos, mediante la utilización de modelos experimentales in vivo, con animales en producción, que refuercen a su vez la incursión en la utilización posterior o concomitante de modelos in vitro

Effect of Ethanol on Parthenogenetic Activation and α-Tocopherol Supplementation during In Vitro Maturation on Developmental Competence of Summer-Collected Bovine Oocytes

The use of α-tocopherol during in vitro maturation (IVM) is an alternative to minimize the adverse effects of heat stress on oocyte competence. However, α-tocopherol is diluted in ethanol, which can induce oocyte parthenogenetic activation (PA). This study aimed to evaluate the role of ethanol concentration on PA and the effect of α-tocopherol supplementation during IVM on the developmental competence and the expression of key genes in blastocysts derived from summer-collected oocytes. All in vitro embryo production was conducted at 5% O2, 5% CO2 at 38.5 °C. Experiment 1: oocytes were cultured with or without 0.05% ethanol. As positive PA control matured oocytes were subjected to 3% or 7% ethanol for 7 min. Oocytes from all groups were placed in fertilization medium (22 h) and culture medium (9 days). Ethanol at 0.05% during IVM did not induce oocyte PA, however, 3% and 7% ethanol were effective parthenogenetic inductors. Experiment 2: oocytes were cultured in maturation medium supplemented with 0, 50, 100 and 200 μM α-tocopherol, diluted in 0.05% ethanol. After in vitro fertilization and embryo culture, we assessed blastocyst apoptotic index and the transcription of a panel of genes. The results showed that supplementation with 100 μM α-tocopherol reduced apoptotic index and increased the expression of SOD2. In conclusion, 100 μM α-tocopherol, diluted in 0.05% ethanol, can be used during IVM to embryonic quality

Environmental Surveillance through Next-Generation Sequencing to Unveil the Diversity of Human Enteroviruses beyond the Reported Clinical Cases

The knowledge about circulation of Human Enteroviruses (EVs) obtained through medical diagnosis in Argentina is scarce. Wastewater samples monthly collected in Córdoba, Argentina during 2011–2012, and then in 2017–2018 were retrospectively studied to assess the diversity of EVs in the community. Partial VP1 gene was amplified by PCR from wastewater concentrates, and amplicons were subject of next-generation sequencing and genetic analyses. There were 41 EVs detected, from which ~50% had not been previously reported in Argentina. Most of the characterized EVs (60%) were detected at both sampling periods, with similar values of intratype nucleotide diversity. Exceptions were enterovirus A71, coxsackievirus B4, echovirus 14, and echovirus 30, which diversified in 2017–2018. There was a predominance of types from EV-C in 2017–2018, evidencing a common circulation of these types throughout the year in the community. Interestingly, high genetic similarity was evidenced among environmental strains of echovirus 30 circulating in 2011–2012 and co-temporal isolates obtained from patients suffering aseptic meningitis in different locations of Argentina. This study provides an updated insight about EVs circulating in an important region of South America, and suggests a valuable role of wastewater-based epidemiology in predicting outbreaks before the onset of cases in the community

l-Carnitine Supplementation during In Vitro Maturation and In Vitro Culture Does not Affect the Survival Rates after Vitrification and Warming but Alters Inf-T and ptgs2 Gene Expression

l-carnitine is a potent antioxidant used for in vitro culture systems. Controversial results have been reported using l-carnitine in culture medium at different stages of in vitro bovine embryo production. Cumulus-oocyte complexes (n = 843) were in vitro-fertilized and cultured and added (treatment group) or not added (control group) with l-carnitine. At day three of culture, each group was subdivided into two subgroups receiving no l-carnitine (group 1), 3.8 mM l-carnitine added during in vitro maturation (group 2), 1.5 mM added during the in vitro culture (group 3), and 3.8 mM and 1.5 mM added during the maturation and culture, respectively (group 4). At day 8, blastocyst embryos were examined for mitochondrial activity, the presence of lipid droplets, total cell number, gene expression, and cryotolerance by vitrification. The data were analyzed with a one-way analysis of variance. l-carnitine added in the late in vitro culture significantly reduced mitochondrial activity and lipid content, and upregulated ifn-τ and ptgs2 gene expression compared to controls (p < 0.05). l-carnitine supplementation did not significantly affect the embryo rate production or survival rate after vitrification and warming (p > 0.05). l-carnitine supplementation significantly improved embryo potential to develop viable pregnancies in agreement with a study reporting improved pregnancy rates

First evidence of enterovirus A71 and echovirus 30 in Uruguay and genetic relationship with strains circulating in the South American region

Human enteroviruses (EVs) comprise more than 100 types of coxsackievirus, echovirus, poliovirus and numbered enteroviruses, which are mainly transmitted by the faecal-oral route leading to diverse diseases such as aseptic meningitis, encephalitis, and acute flaccid paralysis, among others. Since enteroviruses are excreted in faeces, wastewater-based epidemiology approaches are useful to describe EV diversity in a community. In Uruguay, knowledge about enteroviruses is extremely limited. This study assessed the diversity of enteroviruses through Illumina next-generation sequencing of VP1-amplicons obtained by RT-PCR directly applied to viral concentrates of 84 wastewater samples collected in Uruguay during 2011–2012 and 2017–2018. Fifty out of the 84 samples were positive for enteroviruses. There were detected 27 different types belonging to Enterovirus A species (CVA2-A6, A10, A16, EV-A71, A90), Enterovirus B species (CVA9, B1-B5, E1, E6, E11, E14, E21, E30) and Enterovirus C species (CVA1, A13, A19, A22, A24, EV-C99). Enterovirus A71 (EV-A71) and echovirus 30 (E30) strains were studied more in depth through phylogenetic analysis, together with some strains previously detected by us in Argentina. Results unveiled that EV-A71 sub-genogroup C2 circulates in both countries at least since 2011–2012, and that the C1-like emerging variant recently entered in Argentina. We also confirmed the circulation of echovirus 30 genotypes E and F in Argentina, and reported the detection of genotype E in Uruguay. To the best of our knowledge this is the first report of the EV-A71 C1-like emerging variant in South-America, and the first report of EV-A71 and E30 in Uruguay.Fil: Lizasoain, Andrés. Universidad de la República. Centro Universitario del Litoral Norte. Centro Universitario de Salto; UruguayFil: Mir, Daiana. Universidad de la República. Centro Universitario del Litoral Norte. Centro Universitario de Salto; UruguayFil: Salvo, Matías. Universidad de la República. Centro Universitario del Litoral Norte. Centro Universitario de Salto; UruguayFil: Bortagaray, Viviana. Universidad de la República. Centro Universitario del Litoral Norte. Centro Universitario de Salto; UruguayFil: Masachessi, Gisela. Universidad Nacional de Córdoba. Facultad de Medicina. Instituto de Virología Dr. J. M. Vanella; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Farías, Adrián Alejandro. Universidad Nacional de Córdoba. Facultad de Medicina. Instituto de Virología Dr. J. M. Vanella; ArgentinaFil: Rodríguez Osorio, Nélida. Universidad de la República. Centro Universitario del Litoral Norte. Centro Universitario de Salto; UruguayFil: Nates, Silvia Viviana. Universidad Nacional de Córdoba. Facultad de Medicina. Instituto de Virología Dr. J. M. Vanella; ArgentinaFil: Victoria, Matías. Universidad de la República. Centro Universitario del Litoral Norte. Centro Universitario de Salto; UruguayFil: Colina, Rodney. Universidad de la República. Centro Universitario del Litoral Norte. Centro Universitario de Salto; Urugua

Human Enterovirus Diversity by Next-Generation Sequencing Analysis in Urban Sewage Samples From Buenos Aires Metropolitan Area, Argentina: A Retrospective Study

Los enterovirus humanos (hEV) son responsables de una amplia variedad de enfermedades humanas. Durante la infección por hEV, los viriones se excretan en las heces humanas y la vía fecal-oral es la principal vía de transmisión de persona a persona. La vigilancia de las aguas residuales podría ayudar a controlar la circulación de los vehículos eléctricos pesados ​​y describir su diversidad en una población específica. En este estudio, las muestras de aguas residuales recolectadas en el Área Metropolitana de Buenos Aires (Argentina) se estudiaron retrospectivamente a través de un enfoque de secuenciación profunda de amplicón y análisis filogenéticos para caracterizar la propagación de los hEV. Identificamos 17 tipos diferentes de hEV pertenecientes a las especies A, B y C. Hasta donde sabemos, este es el primer informe en Buenos Aires para 7 tipos identificados de hEV-C. Los análisis filogenéticos sugieren varias introducciones de coxsackievirus B4, echovirus 1 y echovirus 9 en el país. junto con la difusión nacional alcanzada por algunas variantes. Además, grupos monofiléticos bien sustentados de cepas argentinas, uruguayas y brasileñas revelaron patrones de circulación regional para algunas variantes. Estos resultados amplían nuestro conocimiento sobre la circulación de vehículos pesados ​​en Buenos Aires y podrían exhortar a las autoridades a implementar una vigilancia más activa de las aguas residuales en la región.Fil: Lizasoain, Andrés. Universidad de la República. Centro Universitario del Litoral Norte. Centro Universitario de Salto; UruguayFil: Mir, Diego Damián. Universidad de la República. Centro Universitario del Litoral Norte. Centro Universitario de Salto; UruguayFil: Victoria, Marta. Universidad de la República. Centro Universitario del Litoral Norte. Centro Universitario de Salto; UruguayFil: Barrios, Melina Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Nanobiotecnología. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones en Bacteriología y Virología Molecular; ArgentinaFil: Blanco Fernandez, Maria Dolores. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones en Bacteriología y Virología Molecular; ArgentinaFil: Rodríguez Osorio, Nélida. Universidad de la República. Centro Universitario del Litoral Norte. Centro Universitario de Salto; UruguayFil: Nates, Silvia Viviana. Universidad Nacional de Córdoba. Facultad de Medicina. Instituto de Virología Dr. J. M. Vanella; ArgentinaFil: Cisterna, Daniel Marcelo. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbrán"; ArgentinaFil: Mbayed, Viviana Andrea. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones en Bacteriología y Virología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Colina, Rodney. Universidad de la República. Centro Universitario del Litoral Norte. Centro Universitario de Salto; Urugua

Table_1_Characterization of strains of Anaplasma marginale from clinical cases in bovine using major surface protein 1a in Uruguay.docx

The major surface protein 1a (MSP1a) gene has been used to characterize Anaplasma marginale genetic diversity. This pathogen causes significant productivity and economic losses to the cattle industry. The objective of the present study was to report the first characterization of A. marginale genetic diversity in Uruguay based on MSP1a genotypes and their putative relationship with Rhipicephalus microplus. This cross-sectional study was conducted between 2016 and 2020. The study included whole blood samples from clinical cases of bovine anaplasmosis obtained from 30 outbreaks located in six Uruguay territorial departments. Diagnosis was performed using Giemsa-stained smears and confirmed by nested Polymerase Chance Reaction (nPCR) targeting the A. marginale major surface protein 5 gene. The genetic diversity of A. marginale strains was characterized by analyzing the microsatellite and tandem repeats of MSP1a. Based on the microsatellite structure, four genotypes were identified. Genotype E was the most prevalent. Analysis of MSP1a tandem repeats showed 28 different strains from the combination of 31 repeats, with τ-10-15 and α-β-β-β-Γ being the most common. Repeats Γ, β, α, and γ were associated with the absence of R. microplus with statistical significance (p < 0.05). Molecular observations showed that 46.7% of the strains identified in our samples lacked the ability to bind to tick cells; therefore, they were probably transmitted by other vectors. Strain genetic diversity provides valuable information for understanding the epidemiological behavior of A. marginale and could contribute to the development of effective vaccines for the control of this disease.</p