http://sedici.unlp.edu.ar:80/handle/10915/73455 Tue, 27 Oct 2026 01:59:51 GMT 2026-10-27T01:59:51Z http://sedici.unlp.edu.ar:80/handle/10915/200371 Objeto de conferencia I Jornada de Divulgación en Biotecnología (La Plata, 20 y 21 de octubre de 2022); Revista digital de la 1ra Jornada de Divulgación en Biotecnología; 2022; https://sedici.unlp.edu.ar/handle/10915/155920; Libro de resúmenes del Congreso de Investigaciones Formativas IFLP – 2026 En este proyecto de tesina, trabajaremos sobre la hipótesis del rol protectivo que ejerce apolipoproteína A-I (apoA-I), la proteína mayoritaria de las HDL, al remover lípidos celulares y posibilitar el cambio hacia un fenotipo anti-inflamatorio en macrófagos. Los desórdenes en el metabolismo de lipoproteínas constituyen una de las principales causas de enfermedad cardiovascular prematura, siendo la deficiencia de colesterol en HDL, así como los niveles elevados de colesterol en LDL, las anormalidades más frecuentes. La aterogénesis involucra la unión de lipoproteínas plasmáticas, principalmente LDLs oxidadas, en la pared arterial, lo que induce el reclutamiento de macrófagos, que fagocitan progresivamente las LDLox, adoptando el fenotipo espumoso; éstos se acumulan en el endotelio formando la placa ateromatosa inicial y promueven la respuesta inflamatoria. El fenotipo de macrófagos M1 es el tipo pro-inflamatorio; mientras que el fenotipo M2 está involucrado en la resolución de la inflamación. Sin embargo, no hay datos referentes sobre la caracterización fenotípica del estado inflamatorio (M1/M2) como consecuencia de las respuestas que podría causar una proteína típica antiaterogénica como es apoA-I. Así proponemos: Purificar apoA-I WT recombinante expresada en bacterias BL21(DE3). Obtener LDLs de plasma humano por ultracentrifugación en gradiente de densidad de NaBr y posterior cromatografía de exclusión molecular en columna de Sephacryl 300. Obtener LDL oxidadas por tratamiento con sulfato de cobre. Evaluar la polarización hacia un perfil pro/anti inflamatorio en macrófagos en presencia de LDLox y/o de apoA-I WT, mediante citometría de flujo; empleando anticuerpos anti- CD86 para M1 y anti-CD206 para M2, marcados con fluoróforos (AF488 y PE). Para lo cual, monocitos humanos de la línea THP1 serán diferenciados a macrófagos con ésteres de forbol, posteriormente transformados en células espumosas por incubación con LDLox, y finalmente tratados con apoA-I WT. Es probable que la exposición de macrófagos a LDLox determine la aparición del fenotipo M1, y en presencia de apoA-I, del fenotipo M2, lo cual aportará información para caracterizar a los distintos subtipos celulares. Sat, 01 Jan 2022 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/200371 2022-01-01T00:00:00Z En este proyecto de tesina, trabajaremos sobre la hipótesis del rol protectivo que ejerce apolipoproteína A-I (apoA-I), la proteína mayoritaria de las HDL, al remover lípidos celulares y posibilitar el cambio hacia un fenotipo anti-inflamatorio en macrófagos. Los desórdenes en el metabolismo de lipoproteínas constituyen una de las principales causas de enfermedad cardiovascular prematura, siendo la deficiencia de colesterol en HDL, así como los niveles elevados de colesterol en LDL, las anormalidades más frecuentes. La aterogénesis involucra la unión de lipoproteínas plasmáticas, principalmente LDLs oxidadas, en la pared arterial, lo que induce el reclutamiento de macrófagos, que fagocitan progresivamente las LDLox, adoptando el fenotipo espumoso; éstos se acumulan en el endotelio formando la placa ateromatosa inicial y promueven la respuesta inflamatoria. El fenotipo de macrófagos M1 es el tipo pro-inflamatorio; mientras que el fenotipo M2 está involucrado en la resolución de la inflamación. Sin embargo, no hay datos referentes sobre la caracterización fenotípica del estado inflamatorio (M1/M2) como consecuencia de las respuestas que podría causar una proteína típica antiaterogénica como es apoA-I. Así proponemos: Purificar apoA-I WT recombinante expresada en bacterias BL21(DE3). Obtener LDLs de plasma humano por ultracentrifugación en gradiente de densidad de NaBr y posterior cromatografía de exclusión molecular en columna de Sephacryl 300. Obtener LDL oxidadas por tratamiento con sulfato de cobre. Evaluar la polarización hacia un perfil pro/anti inflamatorio en macrófagos en presencia de LDLox y/o de apoA-I WT, mediante citometría de flujo; empleando anticuerpos anti- CD86 para M1 y anti-CD206 para M2, marcados con fluoróforos (AF488 y PE). Para lo cual, monocitos humanos de la línea THP1 serán diferenciados a macrófagos con ésteres de forbol, posteriormente transformados en células espumosas por incubación con LDLox, y finalmente tratados con apoA-I WT. Es probable que la exposición de macrófagos a LDLox determine la aparición del fenotipo M1, y en presencia de apoA-I, del fenotipo M2, lo cual aportará información para caracterizar a los distintos subtipos celulares. http://sedici.unlp.edu.ar:80/handle/10915/200368 Objeto de conferencia I Jornada de Divulgación en Biotecnología (La Plata, 20 y 21 de octubre de 2022); Revista digital de la 1ra Jornada de Divulgación en Biotecnología; 2022; https://sedici.unlp.edu.ar/handle/10915/155920; Libro de resúmenes del Congreso de Investigaciones Formativas IFLP – 2026 Los hongos entomopatógenos resultan atractivos para el control de insectos plaga en la agricultura por no dejar residuos nocivos para el hombre y el medio ambiente y no generar fenómenos de resistencia en los insectos (Lacey et al., 2015). Los microesclerocios (ME) son propágulos fúngicos tolerantes a la desecación formados por agregados de hifas melanizadas de 200-600 μm de diámetro (Jackson y Jaronski, 2012). Actualmente no se conoce la identidad ni el rol de las melaninas en ME de hongos entomopatógenos. El agregado en concentraciones subletales de inhibidores de la síntesis de melaninas en los medios de cultivo es una técnica ampliamente utilizada en la caracterización de estos pigmentos, y los resultados derivados de ese tipo de experimentos suelen ser suficientes para determinar la presencia y el tipo de melanina en las células estudiadas (Butler y Day, 1998). Se cultivó el hongo entomopatógeno Metarhizium robertsii cepa ARSEF 2575 en medios líquidos en presencia y ausencia de triciclazole (inhibidor de melaninas tipo DHN) a distintas concentraciones. Se analizaron distintos parámetros del cultivo como pH, biomasa seca, concentración y tamaño de propágulos producidos, concentración de pigmentos, tolerancia al secado y a la temperatura, de acuerdo a Saparrat et al. (2009), Huarte-Bonnet et. al (2019), Babitskaya et al. (2000), y Paixao et. al (2021). Sat, 01 Jan 2022 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/200368 2022-01-01T00:00:00Z Los hongos entomopatógenos resultan atractivos para el control de insectos plaga en la agricultura por no dejar residuos nocivos para el hombre y el medio ambiente y no generar fenómenos de resistencia en los insectos (Lacey et al., 2015). Los microesclerocios (ME) son propágulos fúngicos tolerantes a la desecación formados por agregados de hifas melanizadas de 200-600 μm de diámetro (Jackson y Jaronski, 2012). Actualmente no se conoce la identidad ni el rol de las melaninas en ME de hongos entomopatógenos. El agregado en concentraciones subletales de inhibidores de la síntesis de melaninas en los medios de cultivo es una técnica ampliamente utilizada en la caracterización de estos pigmentos, y los resultados derivados de ese tipo de experimentos suelen ser suficientes para determinar la presencia y el tipo de melanina en las células estudiadas (Butler y Day, 1998). Se cultivó el hongo entomopatógeno Metarhizium robertsii cepa ARSEF 2575 en medios líquidos en presencia y ausencia de triciclazole (inhibidor de melaninas tipo DHN) a distintas concentraciones. Se analizaron distintos parámetros del cultivo como pH, biomasa seca, concentración y tamaño de propágulos producidos, concentración de pigmentos, tolerancia al secado y a la temperatura, de acuerdo a Saparrat et al. (2009), Huarte-Bonnet et. al (2019), Babitskaya et al. (2000), y Paixao et. al (2021). http://sedici.unlp.edu.ar:80/handle/10915/200360 Objeto de conferencia I Jornada de Divulgación en Biotecnología (La Plata, 20 y 21 de octubre de 2022); Revista digital de la 1ra Jornada de Divulgación en Biotecnología; 2022; https://sedici.unlp.edu.ar/handle/10915/155920; Libro de resúmenes del Congreso de Investigaciones Formativas IFLP – 2026 There is extensive evidence that young blood and plasma possess revitalizing properties in old animals of the same species. In parabiosis experiments, where the circulatory systems of two animals of different ages are joined, a phenotypic change from old animals to the phenotype of a young animal, and vice versa, has been observed. Later works managed to elucidate that the factors responsible for these changes were in the plasmatic fraction of the blood. In our work, inspired by parabiosis experiments, plasma extracted from the blood of young rats was injected into elderly rats, achieving appreciable phenotypic improvements compared to control animals. In this work, we report that repeated injections of young rat plasma to females, initially 25 months old, prolongs the half-life of the animals by almost 2.5 months (about 10 % of their natural lifespan). Treated rats maintained a more youthful appearance than untreated controls. Blood methylation analysis revealed that treated rats remained epigenetically younger than controls. Sat, 01 Jan 2022 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/200360 2022-01-01T00:00:00Z There is extensive evidence that young blood and plasma possess revitalizing properties in old animals of the same species. In parabiosis experiments, where the circulatory systems of two animals of different ages are joined, a phenotypic change from old animals to the phenotype of a young animal, and vice versa, has been observed. Later works managed to elucidate that the factors responsible for these changes were in the plasmatic fraction of the blood. In our work, inspired by parabiosis experiments, plasma extracted from the blood of young rats was injected into elderly rats, achieving appreciable phenotypic improvements compared to control animals. In this work, we report that repeated injections of young rat plasma to females, initially 25 months old, prolongs the half-life of the animals by almost 2.5 months (about 10 % of their natural lifespan). Treated rats maintained a more youthful appearance than untreated controls. Blood methylation analysis revealed that treated rats remained epigenetically younger than controls. http://sedici.unlp.edu.ar:80/handle/10915/200188 Articulo Aging; vol. 14, no. 21 The process of aging is the result of progressive loss of homeostasis and functional body impairment, including the central nervous system, where the hypothalamus plays a key role in regulating aging mechanisms. The consequences of aging include a chronic proinflammatory environment in the hypothalamus that leads to decreased secretion of gonadotropin-releasing hormone (GnRH) and impairs kisspeptin neuron functionality. In this work, we investigated the effect of insulin-like growth factor 1 (IGF1) gene therapy on hypothalamic kisspeptin/GnRH neurons and on microglial cells, that mediate the inflammatory process related with the aging process. The results show that IGF1 rats have higher kisspeptin expression in the anteroventral periventricular (AVPV) nucleus and higher immunoreactivity of GnRH in the arcuate nucleus and median eminence. In addition, IGF1-treated animals exhibit increased numbers of Iba1+ microglial cells and MHCII+ /Iba1+ in the AVPV and arcuate nuclei. In conclusion, IGF1 gene therapy maintains kisspeptin production in the AVPV nucleus, induces GnRH release in the median eminence, and alters the number and reactivity of microglial cells in middle-aged female rats. We suggest that IGF1 gene therapy may have a protective effect against reproductive decline. Tue, 01 Nov 2022 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/200188 2022-11-01T00:00:00Z The process of aging is the result of progressive loss of homeostasis and functional body impairment, including the central nervous system, where the hypothalamus plays a key role in regulating aging mechanisms. The consequences of aging include a chronic proinflammatory environment in the hypothalamus that leads to decreased secretion of gonadotropin-releasing hormone (GnRH) and impairs kisspeptin neuron functionality. In this work, we investigated the effect of insulin-like growth factor 1 (IGF1) gene therapy on hypothalamic kisspeptin/GnRH neurons and on microglial cells, that mediate the inflammatory process related with the aging process. The results show that IGF1 rats have higher kisspeptin expression in the anteroventral periventricular (AVPV) nucleus and higher immunoreactivity of GnRH in the arcuate nucleus and median eminence. In addition, IGF1-treated animals exhibit increased numbers of Iba1+ microglial cells and MHCII+ /Iba1+ in the AVPV and arcuate nuclei. In conclusion, IGF1 gene therapy maintains kisspeptin production in the AVPV nucleus, induces GnRH release in the median eminence, and alters the number and reactivity of microglial cells in middle-aged female rats. We suggest that IGF1 gene therapy may have a protective effect against reproductive decline. http://sedici.unlp.edu.ar:80/handle/10915/195357 Articulo Proceedings of the Royal Society B: Biological Sciences; vol. 293, no. 2064 Oviparous animals have evolved diverse strategies that deter egg predation. In terrestrial species, these often include noxious compounds and aposematic signalling, but little is known in freshwater environments. Here, we unravel the evolutionary and ecological strategies of Pomacea, aquatic snails that lay conspicuous masses of toxic orange-pink eggs to reduce predation risk. We reveal the interplay among warning coloration, toxicity and predator visual perception that enables the evolution of advanced chemical defences. We provide evidence that snails modify dietary carotenoids and that this controls egg coloration in a clade-specific manner. Snails from the canaliculata clade accumulate more and brighter- coloured egg carotenoid pigments than those from the bridgesii clade. The conspicuousness of colour signals was assessed using field data, spectral reflectance measurements and visual modelling. We show that aposematic signal variation among species is likely noticeable to putative waterbird predators. Feeding egg extracts to birds adversely affected their gut morphology. Comparative analysis revealed a correlation among pigment modification, conspicuousness and toxicity, demonstrating that colour acts as an honest aposematic signal in apple snail eggs. To our knowledge, our study provides the first example of an honest aposematic signal in warning coloration among freshwater invertebrates. Sun, 01 Feb 2026 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/195357 2026-02-01T00:00:00Z Oviparous animals have evolved diverse strategies that deter egg predation. In terrestrial species, these often include noxious compounds and aposematic signalling, but little is known in freshwater environments. Here, we unravel the evolutionary and ecological strategies of Pomacea, aquatic snails that lay conspicuous masses of toxic orange-pink eggs to reduce predation risk. We reveal the interplay among warning coloration, toxicity and predator visual perception that enables the evolution of advanced chemical defences. We provide evidence that snails modify dietary carotenoids and that this controls egg coloration in a clade-specific manner. Snails from the canaliculata clade accumulate more and brighter- coloured egg carotenoid pigments than those from the bridgesii clade. The conspicuousness of colour signals was assessed using field data, spectral reflectance measurements and visual modelling. We show that aposematic signal variation among species is likely noticeable to putative waterbird predators. Feeding egg extracts to birds adversely affected their gut morphology. Comparative analysis revealed a correlation among pigment modification, conspicuousness and toxicity, demonstrating that colour acts as an honest aposematic signal in apple snail eggs. To our knowledge, our study provides the first example of an honest aposematic signal in warning coloration among freshwater invertebrates. http://sedici.unlp.edu.ar:80/handle/10915/193527 Articulo Parasitology; vol. 152 no. 8 Dioctophyme renale, the giant kidney worm, is a nematode related to Trichuris sp and is distributed worldwide. These parasites locate in the kidney of their definitive hosts (mainly belonging to the order Carnivora) and have an indirect life cycle with an annelid as the main intermediate host. Humans are rarely affected, but in those that are, 1 or both kidneys are destroyed. In South America, D. renale is widespread in riparian regions where changing climatic conditions, environmental degradation, and compromised sanitation are increasing the risk of distribution of this parasite, including humans. Here, we provide the descriptions of the genetic diversity of the parasite in the region by analysing 73 adult D. renale samples collected from domestic and wild carnivores. The most common hosts were (Canis lupus familiaris) and maned wolf (Chrysocyon brachyurus Fam. Canidae) among domestic and wild carnivores, respectively. This work shows the descriptions of the genetic diversity of this parasite complementing molecular methods and classical and probabilistic phylogeography. Our results strongly suggest that this parasite has been present on the continent long enough to develop local genetic variants. Also, the phylogenies show transmission between localities and bidirectional transmission between domestic and wild species. We now have new tools to understand the ecological dynamics of this parasite such as molecular markers to study its genetic diversity as well as for identification and reporting in cryptic cases. Mon, 28 Oct 2024 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/193527 2024-10-28T00:00:00Z Dioctophyme renale, the giant kidney worm, is a nematode related to Trichuris sp and is distributed worldwide. These parasites locate in the kidney of their definitive hosts (mainly belonging to the order Carnivora) and have an indirect life cycle with an annelid as the main intermediate host. Humans are rarely affected, but in those that are, 1 or both kidneys are destroyed. In South America, D. renale is widespread in riparian regions where changing climatic conditions, environmental degradation, and compromised sanitation are increasing the risk of distribution of this parasite, including humans. Here, we provide the descriptions of the genetic diversity of the parasite in the region by analysing 73 adult D. renale samples collected from domestic and wild carnivores. The most common hosts were (Canis lupus familiaris) and maned wolf (Chrysocyon brachyurus Fam. Canidae) among domestic and wild carnivores, respectively. This work shows the descriptions of the genetic diversity of this parasite complementing molecular methods and classical and probabilistic phylogeography. Our results strongly suggest that this parasite has been present on the continent long enough to develop local genetic variants. Also, the phylogenies show transmission between localities and bidirectional transmission between domestic and wild species. We now have new tools to understand the ecological dynamics of this parasite such as molecular markers to study its genetic diversity as well as for identification and reporting in cryptic cases. http://sedici.unlp.edu.ar:80/handle/10915/193479 Articulo Scientific Reports; vol. 15 no. 1 Astrocytes are essential for maintaining neuronal health and regulating the brain's inflammatory environment. In this study, we developed an adeno-associated viral vector (AAV9) designed to selectively overexpress glial cell line-derived neurotrophic factor (GDNF) in astrocytes, using the astrocyte-specific GFAP promoter and TdTomato for transduction tracking. This approach yielded targeted GDNF expression in hippocampal astrocytes. Sholl analysis revealed that GDNF overexpression significantly enhanced astrocytic branching complexity and process length. Using the intracerebroventricular streptozotocin (STZ) model of neurodegeneration, we evaluated the impact of GDNF on astrocytic morphology, neuroinflammation, and hippocampal-dependent memory. Although GDNF prevented astrocytic process length reduction, it did not mitigate neuroinflammation, as evidenced by persistent microglial activation, nor did it improve deficits in the novel object recognition task. However, GDNF + STZ treated animals performed similarly as SHAM controls at exploring the goal sector at the Barnes Maze. These findings demonstrate the capacity of the AAV-GFAP-GDNF-TdTom construct to induce astrocytic branching and partially preserve memory function. They also underscore its partial therapeutic potential in a neuroinflammatory, metabolically compromised and neurodegenerative context. Mon, 02 Jun 2025 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/193479 2025-06-02T00:00:00Z Astrocytes are essential for maintaining neuronal health and regulating the brain's inflammatory environment. In this study, we developed an adeno-associated viral vector (AAV9) designed to selectively overexpress glial cell line-derived neurotrophic factor (GDNF) in astrocytes, using the astrocyte-specific GFAP promoter and TdTomato for transduction tracking. This approach yielded targeted GDNF expression in hippocampal astrocytes. Sholl analysis revealed that GDNF overexpression significantly enhanced astrocytic branching complexity and process length. Using the intracerebroventricular streptozotocin (STZ) model of neurodegeneration, we evaluated the impact of GDNF on astrocytic morphology, neuroinflammation, and hippocampal-dependent memory. Although GDNF prevented astrocytic process length reduction, it did not mitigate neuroinflammation, as evidenced by persistent microglial activation, nor did it improve deficits in the novel object recognition task. However, GDNF + STZ treated animals performed similarly as SHAM controls at exploring the goal sector at the Barnes Maze. These findings demonstrate the capacity of the AAV-GFAP-GDNF-TdTom construct to induce astrocytic branching and partially preserve memory function. They also underscore its partial therapeutic potential in a neuroinflammatory, metabolically compromised and neurodegenerative context. http://sedici.unlp.edu.ar:80/handle/10915/190288 Objeto de conferencia II Congreso Argentino de Malacología (CAM) (Mendoza, 10 al 12 de agosto de 2016); Libro de Resúmenes del Segundo Congreso Argentino de Malacología El caracol dulciacuícola Pomacea canaliculata (Lamarck, 1822) deposita masas de huevos coloreadas fuera del agua que están bien defendidas de los depredadores por un conjunto de proteínas toxicas y antinutritivas que se sintetizan en la glándula del albumen (GA), un órgano accesorio del sistema reproductor de la hembra que posee un llamativo color rosado-rojizo. A pesar de la importante contribución de la GA a la biomasa corporal, observaciones de campo indican que los depredadores la descartan, incluyendo el gavilán caracolero Rostrhamus sociabilis (Vieillot, 1817) un especialista que se alimenta casi exclusivamente de caracoles del género Pomacea. Fri, 01 Jan 2016 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/190288 2016-01-01T00:00:00Z El caracol dulciacuícola Pomacea canaliculata (Lamarck, 1822) deposita masas de huevos coloreadas fuera del agua que están bien defendidas de los depredadores por un conjunto de proteínas toxicas y antinutritivas que se sintetizan en la glándula del albumen (GA), un órgano accesorio del sistema reproductor de la hembra que posee un llamativo color rosado-rojizo. A pesar de la importante contribución de la GA a la biomasa corporal, observaciones de campo indican que los depredadores la descartan, incluyendo el gavilán caracolero Rostrhamus sociabilis (Vieillot, 1817) un especialista que se alimenta casi exclusivamente de caracoles del género Pomacea. http://sedici.unlp.edu.ar:80/handle/10915/189513 Articulo Addiction Neuroscience; vol. 17 Recurrent cocaine seeking is a hallmark of cocaine use disorder. To develop therapeutic targets, it is critical to understand the neurobiological changes specific to cocaine-seeking in context with the seeking of non-drug rewards, e.g., sucrose. The nucleus accumbens (NAc) and medial prefrontal cortex (mPFC) are known regions associated with cocaine- and sucrose-seeking ensembles, i.e., a sparse population of co-activated neurons linked with behavior. Within ensembles, transcriptomic alterations in the NAc and mPFC underlie the learning and recall of cocaine- and sucrose-seeking behavior. However, the transcriptomics exclusively driving cocaine seeking independent from sucrose seeking have not yet been defined using a within-subject approach. Using Ai14:cFos-TRAP2 transgenic mice in a dual cocaine and sucrose self-administration model, we fluorescently sorted and characterized the transcriptomes defining cocaine-seeking in reference to the sucrose-seeking ensemble, overlapping ensemble in between cocaine and sucrose-seeking, and the non-ensemble population. Our data suggests there are robust transcriptomic changes linked with cocaine-seeking that differ from sucroseseeking ensembles and the non-ensemble population which could guide future studies aimed to detangle cocaineseeking behavior without altering non-drug reward seeking. Sat, 01 Nov 2025 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/189513 2025-11-01T00:00:00Z Recurrent cocaine seeking is a hallmark of cocaine use disorder. To develop therapeutic targets, it is critical to understand the neurobiological changes specific to cocaine-seeking in context with the seeking of non-drug rewards, e.g., sucrose. The nucleus accumbens (NAc) and medial prefrontal cortex (mPFC) are known regions associated with cocaine- and sucrose-seeking ensembles, i.e., a sparse population of co-activated neurons linked with behavior. Within ensembles, transcriptomic alterations in the NAc and mPFC underlie the learning and recall of cocaine- and sucrose-seeking behavior. However, the transcriptomics exclusively driving cocaine seeking independent from sucrose seeking have not yet been defined using a within-subject approach. Using Ai14:cFos-TRAP2 transgenic mice in a dual cocaine and sucrose self-administration model, we fluorescently sorted and characterized the transcriptomes defining cocaine-seeking in reference to the sucrose-seeking ensemble, overlapping ensemble in between cocaine and sucrose-seeking, and the non-ensemble population. Our data suggests there are robust transcriptomic changes linked with cocaine-seeking that differ from sucroseseeking ensembles and the non-ensemble population which could guide future studies aimed to detangle cocaineseeking behavior without altering non-drug reward seeking. http://sedici.unlp.edu.ar:80/handle/10915/182571 Objeto de conferencia V Congreso Latino-Americano de Aracnología (Brasil, 3 a 8 de diciembre de 2017) El desarrollo embrionario y post-embrionario de la araña lobo (Pardosa saltans) se realiza dentro de la ooteca e incluye dos períodos, un período embrionario y un período postembrionario después de la eclosión (evento donde las crías emergen del huevo, pero no de la ooteca). En el presente trabajo hemos estudiado el costo energético de las diferentes etapas del desarrollo embrionario y post-embrionario. Se realizó la primera caracterización bioquímica del vitelo de huevos, embriones y juveniles de arañas lobo. Tanto en huevos como en embriones en diferentes estadios se observó la presencia de lipovitelinas (LVs), compuestas de cuatro apolipoproteínas de 116, 87, 70 y 42 kDa. Las LVs representan entre el 35-45% de las proteínas totales durante el desarrollo. Los principales lípidos de las LVs fueron triglicéridos, fosfolípidos, ácidos grasos libres y esteroles. El contenido calórico del huevo fue de 127 cal/g de peso húmedo, el cual correspondió a 91 cal/g de proteínas, 33 cal/g de lípidos y solo 3 cal/g de carbohidratos. Durante el desarrollo embrionario, desde huevo hasta el estadio postembrionario, se consumieron el 67% de las proteínas, el 51% de los carbohidratos y el 49% de las reservas de triglicéridos. Al final del período post-embrionario, antes de emerger las crías, el stock de energía corporal fue solo del 38% de las reservas de calorías iniciales de los huevos. Sun, 01 Jan 2017 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/182571 2017-01-01T00:00:00Z El desarrollo embrionario y post-embrionario de la araña lobo (Pardosa saltans) se realiza dentro de la ooteca e incluye dos períodos, un período embrionario y un período postembrionario después de la eclosión (evento donde las crías emergen del huevo, pero no de la ooteca). En el presente trabajo hemos estudiado el costo energético de las diferentes etapas del desarrollo embrionario y post-embrionario. Se realizó la primera caracterización bioquímica del vitelo de huevos, embriones y juveniles de arañas lobo. Tanto en huevos como en embriones en diferentes estadios se observó la presencia de lipovitelinas (LVs), compuestas de cuatro apolipoproteínas de 116, 87, 70 y 42 kDa. Las LVs representan entre el 35-45% de las proteínas totales durante el desarrollo. Los principales lípidos de las LVs fueron triglicéridos, fosfolípidos, ácidos grasos libres y esteroles. El contenido calórico del huevo fue de 127 cal/g de peso húmedo, el cual correspondió a 91 cal/g de proteínas, 33 cal/g de lípidos y solo 3 cal/g de carbohidratos. Durante el desarrollo embrionario, desde huevo hasta el estadio postembrionario, se consumieron el 67% de las proteínas, el 51% de los carbohidratos y el 49% de las reservas de triglicéridos. Al final del período post-embrionario, antes de emerger las crías, el stock de energía corporal fue solo del 38% de las reservas de calorías iniciales de los huevos. http://sedici.unlp.edu.ar:80/handle/10915/182570 Objeto de conferencia V Congreso Latino-Americano de Aracnología (Brasil, 3 a 8 de diciembre de 2017) En las especies ovíparas, los lípidos presentes en el vitelo, son la principal fuente de energía necesaria para el desarrollo del embrión, crecimiento y supervivencia de las larvas. Para este estudio, se capturaron en campo a lo largo de todo un año, machos y hembras en diferentes estadíos reproductivos de Polybetes pythagoricus (pre-vitelogénico, vitelogénico temprano, vitelogénico y post-vitelogénico). Se analizaron las fluctuaciones de los diferentes lípidos y ácidos grasos presentes en divertículo intestinal, ovario, músculo y hemolinfa. Por primera vez en arañas se determinaron los índices gonadosomático y hepatosomático. El divertículo intestinal mostró ser el órgano que posee mayor concentración lipídica, siendo los triacilglicéridos los lípidos mayoritarios, demostrando su función de órgano metabólicamente activo. A lo largo de la vitelogénesis se observó una importante acumulación de lípidos en el ovario. Sorpresivamente la fosfatidiletanolamina fue el lipido mayoritario (41%), siendo probablemente sintetizada en el divertículo intestinal, luego liberada a la hemolinfa, transportada y finalmente acumulada en el ovario. Su importancia en el desarrollo embrionario posiblemente se encuentre dada por su función estructural necesaria para mantener la fluidez de las membranas. Los ácidos grasos mayoritarios presente en los diferentes órganos fueron 18:0, 16:0, 18:1 y 18:2. El músculo no participa en el proceso vitelogénico manteniendo constante sus lípidos. Tanto los divertículos intestinales, músculos y hemolinfa de machos, mostraron patrones lipídicos similares a hembras en estadío previtelogénico o post-vitelogénico. Podemos concluir que este es el primer reporte sobre dinámica lipídica durante la vitelogénesis en la clase Arachnida. Sun, 01 Jan 2017 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/182570 2017-01-01T00:00:00Z En las especies ovíparas, los lípidos presentes en el vitelo, son la principal fuente de energía necesaria para el desarrollo del embrión, crecimiento y supervivencia de las larvas. Para este estudio, se capturaron en campo a lo largo de todo un año, machos y hembras en diferentes estadíos reproductivos de Polybetes pythagoricus (pre-vitelogénico, vitelogénico temprano, vitelogénico y post-vitelogénico). Se analizaron las fluctuaciones de los diferentes lípidos y ácidos grasos presentes en divertículo intestinal, ovario, músculo y hemolinfa. Por primera vez en arañas se determinaron los índices gonadosomático y hepatosomático. El divertículo intestinal mostró ser el órgano que posee mayor concentración lipídica, siendo los triacilglicéridos los lípidos mayoritarios, demostrando su función de órgano metabólicamente activo. A lo largo de la vitelogénesis se observó una importante acumulación de lípidos en el ovario. Sorpresivamente la fosfatidiletanolamina fue el lipido mayoritario (41%), siendo probablemente sintetizada en el divertículo intestinal, luego liberada a la hemolinfa, transportada y finalmente acumulada en el ovario. Su importancia en el desarrollo embrionario posiblemente se encuentre dada por su función estructural necesaria para mantener la fluidez de las membranas. Los ácidos grasos mayoritarios presente en los diferentes órganos fueron 18:0, 16:0, 18:1 y 18:2. El músculo no participa en el proceso vitelogénico manteniendo constante sus lípidos. Tanto los divertículos intestinales, músculos y hemolinfa de machos, mostraron patrones lipídicos similares a hembras en estadío previtelogénico o post-vitelogénico. Podemos concluir que este es el primer reporte sobre dinámica lipídica durante la vitelogénesis en la clase Arachnida. http://sedici.unlp.edu.ar:80/handle/10915/182549 Objeto de conferencia V Congreso Latino-Americano de Aracnología (Brasil, 3 a 8 de diciembre de 2017) El análisis de un transcriptoma nos permite visualizar los genes que se están expresando de manera temporal y tejido-específica y con ello tener un panorama claro de las vías metabólicas que están activas en dicho tejido. En el presente trabajo luego de realizar un minitranscriptoma de músculo de la araña Polybetes pythagoricus se obtuvieron unos 400 ESTs (etiquetas de secuencias expresadas) de una librería de cDNA, de los cuales, 60 han mostrado similitud con otras secuencias (algoritmo BLASTX). Se han obtenido 20 contigs (secuencia de ADN con regiones solapadas de un gen en particular) uno de los cuales fue el correspondiente a la enzima arginina quinasa (AK), la cual es una enzima crucial para el metabolismo energético de los invertebrados y se describe como un alérgeno potente para los seres humanos. Se completó el gen de AK mediante amplificación rápida de extremos de ADNc (RACE) para generar una secuencia de 1068 nucleótidos (GenBank MF001441) que codifican una proteína de 384 aminoácidos. La secuencia muestra una gran similitud con otras AK de artrópodos. La AK se sobre expresó en cultivos bacterianos y se purificó a homogeneidad por IMAC. Las constantes cinéticas fueron: constante de Michaelis-Menten 1.7 mM, velocidad máxima 27.77 μmol.min-1.mg de proteína-1 y constante catalitica 75 s-1. Finalmente se obtuvo la estructura cristalina de la AK (desconocida para el orden Araneae) y mediante difracción de rayos X se elucidó el sitio de unión a substrato (PDB 5U8E y 5U92). Este trabajo abre diferentes perspectivas del uso de la bioquímica en arácnidos. Sun, 01 Jan 2017 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/182549 2017-01-01T00:00:00Z El análisis de un transcriptoma nos permite visualizar los genes que se están expresando de manera temporal y tejido-específica y con ello tener un panorama claro de las vías metabólicas que están activas en dicho tejido. En el presente trabajo luego de realizar un minitranscriptoma de músculo de la araña Polybetes pythagoricus se obtuvieron unos 400 ESTs (etiquetas de secuencias expresadas) de una librería de cDNA, de los cuales, 60 han mostrado similitud con otras secuencias (algoritmo BLASTX). Se han obtenido 20 contigs (secuencia de ADN con regiones solapadas de un gen en particular) uno de los cuales fue el correspondiente a la enzima arginina quinasa (AK), la cual es una enzima crucial para el metabolismo energético de los invertebrados y se describe como un alérgeno potente para los seres humanos. Se completó el gen de AK mediante amplificación rápida de extremos de ADNc (RACE) para generar una secuencia de 1068 nucleótidos (GenBank MF001441) que codifican una proteína de 384 aminoácidos. La secuencia muestra una gran similitud con otras AK de artrópodos. La AK se sobre expresó en cultivos bacterianos y se purificó a homogeneidad por IMAC. Las constantes cinéticas fueron: constante de Michaelis-Menten 1.7 mM, velocidad máxima 27.77 μmol.min-1.mg de proteína-1 y constante catalitica 75 s-1. Finalmente se obtuvo la estructura cristalina de la AK (desconocida para el orden Araneae) y mediante difracción de rayos X se elucidó el sitio de unión a substrato (PDB 5U8E y 5U92). Este trabajo abre diferentes perspectivas del uso de la bioquímica en arácnidos. http://sedici.unlp.edu.ar:80/handle/10915/182212 Articulo Neurobiology of Disease; vol. 207 Previous research has shown that international donors can significantly influence national and international environmental governance. However, their influence at the regional level has not yet been sufficiently explored. This study aims to examine the influence of international donors on regional environmental governance agreements, taking the Amazon Cooperation Treaty (ACT) as a case study. Using a documentary analysis covering four decades, reviews of academic literature and media articles, and interviews with key informants, this study traces the influence of donors through three distinct stages: protectionism, formalisation and policy customisation. In the first stage, the limited influence of international donors did not translate into significant changes in the initially low degree of formalisation of the agreement. In the second stage, the moderate to high influence of international donors led member states to enhance the degree of formalisation of the ACT and to adopt for the first time a weak forest-related policy in the search to increase its capacities to attract and manage external funds. In the third stage, the still high influence of international donors increased the strength of the newly adopted forest-focused policy of the ACT to moderate. We conclude that international donors can influence regional environmental governance arrangements by increasing their degree of formalisation and the strength of their (forest) policies, and by customising these policies to their own interests rather than those of the members of the arrangements. Tue, 01 Apr 2025 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/182212 2025-04-01T00:00:00Z Previous research has shown that international donors can significantly influence national and international environmental governance. However, their influence at the regional level has not yet been sufficiently explored. This study aims to examine the influence of international donors on regional environmental governance agreements, taking the Amazon Cooperation Treaty (ACT) as a case study. Using a documentary analysis covering four decades, reviews of academic literature and media articles, and interviews with key informants, this study traces the influence of donors through three distinct stages: protectionism, formalisation and policy customisation. In the first stage, the limited influence of international donors did not translate into significant changes in the initially low degree of formalisation of the agreement. In the second stage, the moderate to high influence of international donors led member states to enhance the degree of formalisation of the ACT and to adopt for the first time a weak forest-related policy in the search to increase its capacities to attract and manage external funds. In the third stage, the still high influence of international donors increased the strength of the newly adopted forest-focused policy of the ACT to moderate. We conclude that international donors can influence regional environmental governance arrangements by increasing their degree of formalisation and the strength of their (forest) policies, and by customising these policies to their own interests rather than those of the members of the arrangements. http://sedici.unlp.edu.ar:80/handle/10915/181377 Articulo Antibiotics; vol. 14, no. 4 Background: The use of antimicrobial peptides (AMPs) as biotechnological tools is an area of growing interest in the research that seeks to improve crop defense. SmAPα1–21 and SmAPγ27–44 were previously reported to inhibit Fusarium graminearum, permeabilize the plasma membrane and induce cytoplasmic disorganization. To exert its activity, SmAPα1–21 initially enters through the basal and apical cells of F. graminearum conidia and then displays a general but non-homogeneous distribution in the cytoplasm of all conidial cells, in contrast. Methods: We analyzed, focusing on membrane interaction, the mode of action of SmAPγ27–44, a peptide based on the γ-core of defensins DefSm2-D and DefSm3, and SmAPα1–21, based on the α-core of DefSm2-D. Additionally, we compared the behavior of SmAPα1–21 with that of SmAP3α1–21 based on DefSm3 but with no activity against F. graminearum. Results: In this study, we showed that SmAPγ27–44 enters the cells with discrete intracellular localization. Furthermore, both peptides disrupted the plasma membrane, but with different modes of action. When large unilamellar liposomes (LUVs) containing phosphatidic acid and ergosterol were used as a filamentous fungal plasma membrane model, SmAPγ27–44 strongly induced aggregation concomitantly with the solubilization of the liposomes and showed the maximal insertion of its tryptophan moiety into the membrane’s hydrophobic interior. In comparison, SmAPα1–21 showed a high effect on the ζ potential of anionic vesicles, vesicle aggregation capacity after reaching a concentration threshold, and moderate transfer of tryptophan to the membrane. SmAP3α1–21, on the other hand, showed poor superficial adsorption to liposomes. Conclusions: In view of our results, a cell penetration peptide-like effect was pictured for the γ-core defensin-derived peptide and a classical AMP action was observed for the α-core defensin-derived one. Tue, 01 Apr 2025 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/181377 2025-04-01T00:00:00Z Background: The use of antimicrobial peptides (AMPs) as biotechnological tools is an area of growing interest in the research that seeks to improve crop defense. SmAPα1–21 and SmAPγ27–44 were previously reported to inhibit Fusarium graminearum, permeabilize the plasma membrane and induce cytoplasmic disorganization. To exert its activity, SmAPα1–21 initially enters through the basal and apical cells of F. graminearum conidia and then displays a general but non-homogeneous distribution in the cytoplasm of all conidial cells, in contrast. Methods: We analyzed, focusing on membrane interaction, the mode of action of SmAPγ27–44, a peptide based on the γ-core of defensins DefSm2-D and DefSm3, and SmAPα1–21, based on the α-core of DefSm2-D. Additionally, we compared the behavior of SmAPα1–21 with that of SmAP3α1–21 based on DefSm3 but with no activity against F. graminearum. Results: In this study, we showed that SmAPγ27–44 enters the cells with discrete intracellular localization. Furthermore, both peptides disrupted the plasma membrane, but with different modes of action. When large unilamellar liposomes (LUVs) containing phosphatidic acid and ergosterol were used as a filamentous fungal plasma membrane model, SmAPγ27–44 strongly induced aggregation concomitantly with the solubilization of the liposomes and showed the maximal insertion of its tryptophan moiety into the membrane’s hydrophobic interior. In comparison, SmAPα1–21 showed a high effect on the ζ potential of anionic vesicles, vesicle aggregation capacity after reaching a concentration threshold, and moderate transfer of tryptophan to the membrane. SmAP3α1–21, on the other hand, showed poor superficial adsorption to liposomes. Conclusions: In view of our results, a cell penetration peptide-like effect was pictured for the γ-core defensin-derived peptide and a classical AMP action was observed for the α-core defensin-derived one. http://sedici.unlp.edu.ar:80/handle/10915/167623 Articulo Biology of Sex Differences; vol. 15 Background Cholesterol (Cho) is an essential lipophilic molecule in cells; however, both its decrease and its increase may favor the development of neurological diseases such as Alzheimer’s disease (AD). Although copper (Cu) is an essential trace metal for cells, the increased plasma concentration of its free form has been linked with AD development and severity. AD affects aged people, but its prevalence and severity are higher in women than in men. We have previously shown that Cu promotes Cho de novo synthesis in immature neurons as well as increased Cho in membrane rafts and Aβ levels in culture medium, but there are no results yet regarding sex differences in the effects of sublethal Cu exposure on Cho de novo synthesis. Methods We examined the potential sex-specific impact of sublethal Cu concentrations on de novo Cho synthesis in primary cultures of male and female astrocytes. We also explored whether this had any correlation with variations in Cho and APP levels within neuronal membrane rafts. Results Flow cytometry analysis demonstrated that Cu treatment leads to a greater increase in ROS levels in female astrocytes than in males. Furthermore, through RT-PCR analysis, we observed an upregulation of SREBP-2 and HMGCR. Consistently, we observed an increase in de novo Cho synthesis. Finally, western blot analysis indicated that the levels of ABCA1 increase after Cu treatment, accompanied by a higher release of radiolabeled Cho and an elevation in Cho and APP levels in neuronal membrane rafts. Importantly, all these results were significantly more pronounced in female astrocytes than in males. Conclusions Our findings confirm that Cu stimulates Cho synthesis in astrocytes, both in a ROS-dependent and -independent manner. Moreover, female astrocytes displayed elevated levels of HMGCR, and de novo Cho synthesis compared to males following TBH and Cu treatments. This corresponds with higher levels of Cho released into the culture medium and a more significant Cho and APP rise within neuronal rafts. We consider that the increased risk of AD in females partly arises from sex-specific responses to metals and/or exogenous substances, impacting key enzyme regulation in various biochemical pathways, including HMGCR. Mon, 01 Jan 2024 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/167623 2024-01-01T00:00:00Z Background Cholesterol (Cho) is an essential lipophilic molecule in cells; however, both its decrease and its increase may favor the development of neurological diseases such as Alzheimer’s disease (AD). Although copper (Cu) is an essential trace metal for cells, the increased plasma concentration of its free form has been linked with AD development and severity. AD affects aged people, but its prevalence and severity are higher in women than in men. We have previously shown that Cu promotes Cho de novo synthesis in immature neurons as well as increased Cho in membrane rafts and Aβ levels in culture medium, but there are no results yet regarding sex differences in the effects of sublethal Cu exposure on Cho de novo synthesis. Methods We examined the potential sex-specific impact of sublethal Cu concentrations on de novo Cho synthesis in primary cultures of male and female astrocytes. We also explored whether this had any correlation with variations in Cho and APP levels within neuronal membrane rafts. Results Flow cytometry analysis demonstrated that Cu treatment leads to a greater increase in ROS levels in female astrocytes than in males. Furthermore, through RT-PCR analysis, we observed an upregulation of SREBP-2 and HMGCR. Consistently, we observed an increase in de novo Cho synthesis. Finally, western blot analysis indicated that the levels of ABCA1 increase after Cu treatment, accompanied by a higher release of radiolabeled Cho and an elevation in Cho and APP levels in neuronal membrane rafts. Importantly, all these results were significantly more pronounced in female astrocytes than in males. Conclusions Our findings confirm that Cu stimulates Cho synthesis in astrocytes, both in a ROS-dependent and -independent manner. Moreover, female astrocytes displayed elevated levels of HMGCR, and de novo Cho synthesis compared to males following TBH and Cu treatments. This corresponds with higher levels of Cho released into the culture medium and a more significant Cho and APP rise within neuronal rafts. We consider that the increased risk of AD in females partly arises from sex-specific responses to metals and/or exogenous substances, impacting key enzyme regulation in various biochemical pathways, including HMGCR. http://sedici.unlp.edu.ar:80/handle/10915/167381 Contribucion a revista Journal of Fungi; vol. 10, no. 2 Since Agostino Bassi first isolated the fungal pathogenic agent of the white muscardine in insects (later named Beauveria bassiana in his honor), and Ilya Mechnikov cultivated Metarhizium anisopliae as a first approach to use fungi as pest control agents, many other entomopathogenic fungi have been studied over the last two centuries [1,2]. There is evidence of a several-million-year coevolutionary history between invertebrate-pathogenic fungi and their hosts. Fungus–insect interactions are known to drive pathogenic cycles that usually culminate in killing the hosts; however, these fungi are also facultative saprophytes in the soil and/or the rhizosphere [3,4]. They can also develop endophytic relationships with plants, conferring protection to the host plant from the insects that feed on them [5]. In addition to invertebrate pathology, B. bassiana also has diverse applications in a range of other disciplines, including as an important whole-cell eukaryotic biocatalyst, and together with other entomopathogenic fungi, remains a reservoir for the discovery of numerous secondary metabolites with bioactive functions [6]. These topics were addressed in two Special Issues, which have captured a diversity of studies that focus on biological, molecular, and biotechnological aspects of the interaction between insect-related fungi and their wide range of hosts, including arthropods and plants, as well as on the expression of secondary metabolites, and other aspects regarding their catalyst role in biotransformation and bioremediation. A total of 11 original articles and one review article were published in the Special Issues “Multifaceted Beauveria bassiana and Other Insect-Related Fungi 1.0” (9 articles) and “Multifaceted Beauveria bassiana and Other Insect-Related Fungi 2.0” (3 articles). We briefly summarize them in the following paragraphs and encourage readers to explore them fully. Mon, 01 Jan 2024 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/167381 2024-01-01T00:00:00Z Since Agostino Bassi first isolated the fungal pathogenic agent of the white muscardine in insects (later named Beauveria bassiana in his honor), and Ilya Mechnikov cultivated Metarhizium anisopliae as a first approach to use fungi as pest control agents, many other entomopathogenic fungi have been studied over the last two centuries [1,2]. There is evidence of a several-million-year coevolutionary history between invertebrate-pathogenic fungi and their hosts. Fungus–insect interactions are known to drive pathogenic cycles that usually culminate in killing the hosts; however, these fungi are also facultative saprophytes in the soil and/or the rhizosphere [3,4]. They can also develop endophytic relationships with plants, conferring protection to the host plant from the insects that feed on them [5]. In addition to invertebrate pathology, B. bassiana also has diverse applications in a range of other disciplines, including as an important whole-cell eukaryotic biocatalyst, and together with other entomopathogenic fungi, remains a reservoir for the discovery of numerous secondary metabolites with bioactive functions [6]. These topics were addressed in two Special Issues, which have captured a diversity of studies that focus on biological, molecular, and biotechnological aspects of the interaction between insect-related fungi and their wide range of hosts, including arthropods and plants, as well as on the expression of secondary metabolites, and other aspects regarding their catalyst role in biotransformation and bioremediation. A total of 11 original articles and one review article were published in the Special Issues “Multifaceted Beauveria bassiana and Other Insect-Related Fungi 1.0” (9 articles) and “Multifaceted Beauveria bassiana and Other Insect-Related Fungi 2.0” (3 articles). We briefly summarize them in the following paragraphs and encourage readers to explore them fully. http://sedici.unlp.edu.ar:80/handle/10915/164076 Articulo Peptides; vol. 24 To assess the effect of histoneH3on pituitary hormone secretion, rat anterior pituitary (AP) cells were used and growth hormone, prolactin, thyrotropin, luteinizing hormone and follicle stimulating hormone measured by radioimmunoassay. Incubation of cells with H3 (1, 6, and 30mM) stimulated the release of all five hormones in a dose-dependent manner. This effect was blocked by preincubation of H3 with an anti-H3 antibody. Incubation of AP cells with 6mMH3 in the presence of specific AP hormone secretagogues (GRP-6, thyrotropin-releasing hormone (TRH), gonadotropin-releasing hormone (GnRH)) showed additive effects on hormone secretion. Pharmacological experiments suggested that calcium- and diacylglycerol- (DAG) associated pathways, but not cAMP, participate in the hypophysiotropic activity of H3. Our results confirm previous evidence that histones may act as hypophysiotropic signals. Wed, 01 Jan 2003 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/164076 2003-01-01T00:00:00Z To assess the effect of histoneH3on pituitary hormone secretion, rat anterior pituitary (AP) cells were used and growth hormone, prolactin, thyrotropin, luteinizing hormone and follicle stimulating hormone measured by radioimmunoassay. Incubation of cells with H3 (1, 6, and 30mM) stimulated the release of all five hormones in a dose-dependent manner. This effect was blocked by preincubation of H3 with an anti-H3 antibody. Incubation of AP cells with 6mMH3 in the presence of specific AP hormone secretagogues (GRP-6, thyrotropin-releasing hormone (TRH), gonadotropin-releasing hormone (GnRH)) showed additive effects on hormone secretion. Pharmacological experiments suggested that calcium- and diacylglycerol- (DAG) associated pathways, but not cAMP, participate in the hypophysiotropic activity of H3. Our results confirm previous evidence that histones may act as hypophysiotropic signals. http://sedici.unlp.edu.ar:80/handle/10915/162850 Articulo BBA - Biomembranes; vol. 1863 Extracellular nucleotides and nucleosides activate signaling pathways that play major roles in the physiology and pathophysiology of the gastrointestinal tract. Ectonucleotidases hydrolyze extracellular nucleotides and thus regulate ligand exposure to purinergic receptors. In this study, we investigated the expression, localization and activities of ectonucleotidases using Caco-2 cells, a model of human intestinal epithelial cells. In addition, by studying ATP release and the rates of extracellular ATP (eATP) hydrolysis, we analyzed the contribution of these processes to the regulation of eATP in these cells. Results show that Caco-2 cells regulate the metabolism of eATP and by-products by ecto-nucleoside triphosphate diphosphohydrolase-1 and -2, a neutral ecto-phosphatase and ecto-5′-nucleotidase. All these ectoenzymes were kinetically characterized using intact cells, and their presence confirmed by denatured and native gels, western blot and cytoimmunofluorescence techniques. In addition, regulation of eATP was studied by monitoring the dynamic balance between intracellular ATP release and ectoATPase activity. Following mechanical and hypotonic stimuli, Caco-2 cells triggered a strong but transient release of intracellular ATP, with almost no energy cost, leading to a steep increase of eATP concentration, which was later reduced by ectoATPase activity. A data-driven algorithm allowed quantifying and predicting the rates of ATP release and ATP consumption contributing to the dynamic accumulation of ATP at the cell surface. Fri, 01 Oct 2021 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/162850 2021-10-01T00:00:00Z Extracellular nucleotides and nucleosides activate signaling pathways that play major roles in the physiology and pathophysiology of the gastrointestinal tract. Ectonucleotidases hydrolyze extracellular nucleotides and thus regulate ligand exposure to purinergic receptors. In this study, we investigated the expression, localization and activities of ectonucleotidases using Caco-2 cells, a model of human intestinal epithelial cells. In addition, by studying ATP release and the rates of extracellular ATP (eATP) hydrolysis, we analyzed the contribution of these processes to the regulation of eATP in these cells. Results show that Caco-2 cells regulate the metabolism of eATP and by-products by ecto-nucleoside triphosphate diphosphohydrolase-1 and -2, a neutral ecto-phosphatase and ecto-5′-nucleotidase. All these ectoenzymes were kinetically characterized using intact cells, and their presence confirmed by denatured and native gels, western blot and cytoimmunofluorescence techniques. In addition, regulation of eATP was studied by monitoring the dynamic balance between intracellular ATP release and ectoATPase activity. Following mechanical and hypotonic stimuli, Caco-2 cells triggered a strong but transient release of intracellular ATP, with almost no energy cost, leading to a steep increase of eATP concentration, which was later reduced by ectoATPase activity. A data-driven algorithm allowed quantifying and predicting the rates of ATP release and ATP consumption contributing to the dynamic accumulation of ATP at the cell surface. http://sedici.unlp.edu.ar:80/handle/10915/162849 Articulo Biochemistry; vol. 62, no. 12 Alpha hemolysin of Escherichia coli (HlyA) is a pore-forming protein, which is a prototype of the “Repeat in Toxins” (RTX) family. It was demonstrated that HlyA-cholesterol interaction facilitates the insertion of the toxin into membranes. Putative cholesterol-binding sites, called cholesterol recognition/amino acid consensus (CRAC), and CARC (analogous to CRAC but with the opposite orientation) were identified in the HlyA sequence. In this context, two peptides were synthesized, one derived from a CARC site from the insertion domain of the toxin (residues 341-353) (PEP 1) and the other one from a CRAC site from the domain between the acylated lysines (residues 639-644) (PEP 2), to study their role in the interaction of HlyA with membranes. The interaction of peptides with membranes of different lipid compositions (pure POPC and POPC/Cho of 4:1 and 2:1 molar ratios) was analyzed by surface plasmon resonance and molecular dynamics simulations. Results demonstrate that both peptides interact preferentially with Cho-containing membranes, although PEP 2 presents a lower KD than PEP 1. Molecular dynamics simulation results indicate that the insertion and interaction of PEP 2 with Cho-containing membranes are more prominent than those caused by PEP 1. The hemolytic activity of HlyA in the presence of peptides indicates that PEP 2 was the only one that inhibits HlyA activity, interfering in the binding between the toxin and cholesterol. © 2023 American Chemical Society. Tue, 20 Jun 2023 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/162849 2023-06-20T00:00:00Z Alpha hemolysin of Escherichia coli (HlyA) is a pore-forming protein, which is a prototype of the “Repeat in Toxins” (RTX) family. It was demonstrated that HlyA-cholesterol interaction facilitates the insertion of the toxin into membranes. Putative cholesterol-binding sites, called cholesterol recognition/amino acid consensus (CRAC), and CARC (analogous to CRAC but with the opposite orientation) were identified in the HlyA sequence. In this context, two peptides were synthesized, one derived from a CARC site from the insertion domain of the toxin (residues 341-353) (PEP 1) and the other one from a CRAC site from the domain between the acylated lysines (residues 639-644) (PEP 2), to study their role in the interaction of HlyA with membranes. The interaction of peptides with membranes of different lipid compositions (pure POPC and POPC/Cho of 4:1 and 2:1 molar ratios) was analyzed by surface plasmon resonance and molecular dynamics simulations. Results demonstrate that both peptides interact preferentially with Cho-containing membranes, although PEP 2 presents a lower KD than PEP 1. Molecular dynamics simulation results indicate that the insertion and interaction of PEP 2 with Cho-containing membranes are more prominent than those caused by PEP 1. The hemolytic activity of HlyA in the presence of peptides indicates that PEP 2 was the only one that inhibits HlyA activity, interfering in the binding between the toxin and cholesterol. © 2023 American Chemical Society. http://sedici.unlp.edu.ar:80/handle/10915/162844 Preprint Placenta; 2024 Introduction: Almost 80% of urinary tract infections during pregnancy are caused by uropathogenic strains of Escherichia coli. Alpha-hemolysin, toxin secreted by them, has a fundamental role in this pathology development. Considering that urinary tract infections are related with premature rupture of fetal membranes, we proposed to evaluate the effects that alpha-hemolysin induces on human-fetal-membranes. Methods: Thirteen fetal membranes obtained from elective cesarean sections (>37 weeks) were mounted in a transwell-device generating two independent chambers. To mimic an ascendant-urinary-tract infection, membranes were incubated with different concentrations of pure alpha-hemolysin from the choriodecidual side during 24h. Extensive histological analyses were performed and transepithelial electrical-resistance were determined. Cell viability, metalloproteinase activity and cyclooxygenase-2- gene expression was estimated by lactate-dehydrogenase–release assay, zymography and RT-qPCR, respectively. Finally, four fetal membranes were treated with hemolysin preincubated with polyclonal anti-hemolysin antibodies. Cell viability and metalloproteinase activity were monitored. Results: After 24 h of treatment, fetal membranes evidenced a structural damage and a decrease in membrane resistance that progressed as the concentration of alpha hemolysin increased. While the amniotic-epithelial-layer remained practically unaffected, the chorion cells manifested an increase in vacuolization and necrosis. In addition, the extracellular matrix exhibited collagen-fiber disorganization, a marked decrease in fiber content, and became thicker in presence of the toxin. Cyclooxigenase-2 expression and metalloproteinase activity were also higher in the treated groups than in untreated ones. Finally, a preincubation of hemolysin with specific antibodies prevented the cytotoxicity on the chorion cells and the increase in metalloproteinase activity. Discussion: Hemolysin induces structural and molecular changes associated with the remodeling of human-fetal-membranes in-vitro. Tue, 13 Feb 2024 00:00:00 GMT http://sedici.unlp.edu.ar:80/handle/10915/162844 2024-02-13T00:00:00Z Introduction: Almost 80% of urinary tract infections during pregnancy are caused by uropathogenic strains of Escherichia coli. Alpha-hemolysin, toxin secreted by them, has a fundamental role in this pathology development. Considering that urinary tract infections are related with premature rupture of fetal membranes, we proposed to evaluate the effects that alpha-hemolysin induces on human-fetal-membranes. Methods: Thirteen fetal membranes obtained from elective cesarean sections (>37 weeks) were mounted in a transwell-device generating two independent chambers. To mimic an ascendant-urinary-tract infection, membranes were incubated with different concentrations of pure alpha-hemolysin from the choriodecidual side during 24h. Extensive histological analyses were performed and transepithelial electrical-resistance were determined. Cell viability, metalloproteinase activity and cyclooxygenase-2- gene expression was estimated by lactate-dehydrogenase–release assay, zymography and RT-qPCR, respectively. Finally, four fetal membranes were treated with hemolysin preincubated with polyclonal anti-hemolysin antibodies. Cell viability and metalloproteinase activity were monitored. Results: After 24 h of treatment, fetal membranes evidenced a structural damage and a decrease in membrane resistance that progressed as the concentration of alpha hemolysin increased. While the amniotic-epithelial-layer remained practically unaffected, the chorion cells manifested an increase in vacuolization and necrosis. In addition, the extracellular matrix exhibited collagen-fiber disorganization, a marked decrease in fiber content, and became thicker in presence of the toxin. Cyclooxigenase-2 expression and metalloproteinase activity were also higher in the treated groups than in untreated ones. Finally, a preincubation of hemolysin with specific antibodies prevented the cytotoxicity on the chorion cells and the increase in metalloproteinase activity. Discussion: Hemolysin induces structural and molecular changes associated with the remodeling of human-fetal-membranes in-vitro.