Person:
Isorna Alonso, Esther

First Name

Esther

Last Name

Isorna Alonso

URI

https://hdl.handle.net/20.500.14352/74410

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Biológicas

Department

Genética, Fisiología y Microbiología

Area

Fisiología

Identifiers

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Now showing 1 - 10 of 24

Project number: 247
Herramientas innovadoras docentes para reforzar competencias transversales: Noche PechaKucha interdisciplinar sobre Derechos Humanos
(2015) Paredes Royano, Sergio Damián; Blázquez Rodríguez, María Isabel; Cornejo Valle, Mónica; Pichardo Galán, José Ignacio; Isorna Alonso, Esther; Marc Martínez, Isabelle; Simón Adiago, Carlos Mª; Solbes Canales, Irene; Gredilla Diaz, Ricardo; González Martín, Antonio
Nuclear receptors (PPARs, REV-ERBs, RORs) and clock gene rhythms in goldfish (Carassius auratus) are differently regulated in hypothalamus and liver
(Frontiers in Physiology, 2022) Gómez-Boronat, Miguel; Pedro Ormeño, Nuria de; Alonso Gómez, Ángel Luis; Delgado Saavedra, María Jesús; Isorna Alonso, Esther
The circadian system is formed by a network of oscillators located in central and peripheral tissues that are tightly linked to generate rhythms in vertebrates to adapt the organism to the cyclic environmental changes. The nuclear receptors PPARs, REV-ERBs and RORs are transcription factors controlled by the circadian system that regulate, among others, a large number of genes that control metabolic processes for which they have been proposed as key genes that link metabolism and temporal homeostasis. To date it is unclear whether these nuclear receptors show circadian expression and which zeitgebers are important for their synchronization in fish. Therefore, the objective of this study was to investigate whether the two main zeitgebers (light-dark cycle and feeding time) could affect the synchronization of central (hypothalamus) and peripheral (liver) core clocks and nuclear receptors in goldfish. To this aim, three experimental groups were established: fish under a 12 h light-12 h darkness and fed at Zeitgeber Time 2; fish with the same photoperiod but randomly fed; and fish under constant darkness and fed at Circadian Time 2. After one month, clock genes and nuclear receptors expression in hypothalamus and liver and circulating glucose were studied. Clock genes displayed daily rhythms in both tissues of goldfish if the light-dark cycle was present, with shifted-acrophases of negative and positive elements, as expected for proper functioning clocks. In darkness-maintained fish hypothalamic clock genes were fully arrhythmic while the hepatic ones were still rhythmic. Among studied nuclear receptors, in the hypothalamus only nr1d1 was rhythmic and only when the light-dark cycle was present. In the liver all nuclear receptors were rhythmic when both zeitgebers were present, but only nr1d1 when one of them was removed. Plasma glucose levels showed significant rhythms in fish maintained under random fed regimen or constant darkness, with the highest levels at 1-h postprandially in all groups. Altogether these results support that hypothalamus is mainly a light-entrained-oscillator, while the liver is a food-entrained-oscillator. Moreover, nuclear receptors are revealed as clear outputs of the circadian system acting as key elements in the timekeeping of temporal homeostasis, particularly in the liver.
The satiety factor oleoylethanolamide impacts hepatic lipid and glucose metabolism in goldfish
(Journal of Comparative Physiology B, 2016) Gómez Boronat, Miguel; Velasco, Cristina; Isorna Alonso, Esther; Pedro Ormeño, Nuria de; Delgado Saavedra, María Jesús; Soengas, José L.
Oleoylethanolamide (OEA) is an acylethanolamide synthesized mainly in the gastrointestinal tract with known effects in mammals on food intake and body mass through activation of peroxisome proliferator-activated receptor type α (PPARα). Since we previously demonstrated that acute treatment with OEA in goldfish resulted in decreased food intake and locomotor activity, as in mammals, we hypothesize that OEA would be involved in the control of energy metabolism in fish. Therefore, we assessed the effects of acute (for 6 h) and chronic (for 11 days) treatments with OEA (5 µg g−1 body mass) on metabolite concentrations and enzyme activities related to glucose and lipid metabolism in liver of goldfish (Carassius auratus). In the chronic treatment, OEA impairs the increase in body mass and reduces locomotor activity, without any signs of stress. The lipolytic capacity in liver decreased after both acute and chronic OEA treatments, whereas lipogenic capacity increased after acute and decreased after chronic treatment with OEA. These results are different from those observed to date in mammalian adipose tissue, but not so different from those known in liver, and might be attributed to the absence of changes in the expression of pparα, and/or to the increase in the expression of the clock gene bmal1a after chronic OEA treatment. As for glucose metabolism, a clear decrease in the capacity of hepatic tissue to use glucose was observed in OEA-treated fish. These results support an important role for OEA in the regulation of liver lipid and glucose metabolism, and could relate to the metabolic changes associated with circadian activity and the regulation of food intake in fish.
Diurnal Profiles of N-Acylethanolamines in Goldfish Brain and Gastrointestinal Tract: Possible Role of Feeding
(Frontiers in Neuroscience, 2019) Gómez-Boronat, Miguel; Isorna Alonso, Esther; Armirotti, Andrea; Delgado Saavedra, María Jesús; Piomelli, Danielle; Pedro Ormeño, Nuria de
N-acylethanolamines (NAEs) are a family of endogenous lipid signaling molecules that are involved in regulation of energy homeostasis in vertebrates with a putative role on circadian system. The aim of this work was to study the existence of daily fluctuations in components of NAEs system and their possible dependence on food intake. Specifically, we analyzed the content of oleoylethanolamide (OEA), palmitoylethanolamide (PEA), stearoylethanolamide (SEA), their precursors (NAPEs), as well as the expression of nape-pld (NAEs synthesis enzyme), faah (NAEs degradation enzyme), and pparα (NAEs receptor) in gastrointestinal and brain tissues of goldfish (Carassius auratus) throughout a 24-h cycle. Daily profiles of bmal1a and rev-erbα expression in gastrointestinal tissues were also quantified because these clock genes are also involved in lipid metabolism, are PPAR-targets in mammals, and could be a link between NAEs and circadian system in fish. Gastrointestinal levels of NAEs exhibited daily fluctuations, with a pronounced and rapid postprandial increase, the increment being likely caused by food intake as it is not present in fasted animals. Such periprandial differences were not found in brain, supporting that NAEs mobilization occurs in a tissue-specific manner and suggesting that these three NAEs could be acting as peripheral satiety signals. The abundance of pparα mRNA displayed a daily rhythm in the intestine and the liver, suggesting a possible rhythmicity in the NAEs functionality. The increment of pparα expression during the rest phase can be related with its role stimulating lipid catabolism to obtain energy during the fasting state of the animals. In addition, the clock genes bmal1a and rev-erbα also showed daily rhythms, with a bmal1a increment after feeding, supporting its role as a lipogenic factor. In summary, our data show the existence of all components of NAEs system in fish (OEA, PEA, SEA, precursors, synthesis and degradation enzymes, and the receptor PPARα), supporting the involvement of NAEs as peripheral satiety signals.
Ghrelin induces clock gene expression in the liver of goldfish in vitro via protein kinase C and protein kinase A pathways
(Journal of Experimental Biology, 2017) Sánchez Bretaño, Aída; Blanco Imperiali, Ayelén M.; Alonso Gómez, Ángel Luis; Delgado Saavedra, María Jesús; Kah, Olivier; Isorna Alonso, Esther
The liver is the most important link between the circadian system and metabolism. As a food-entrainable oscillator, the hepatic clock needs to be entrained by food-related signals. The objective of the present study was to investigate the possible role of ghrelin (an orexigenic peptide mainly synthesized in the gastrointestinal tract) as an endogenous synchronizer of the liver oscillator in teleosts. To achieve this aim, we first examined the presence of ghrelin receptors in the liver of goldfish. Then, the ghrelin regulation of clock gene expression in the goldfish liver was studied. Finally, the possible involvement of the phospholipase C/protein kinase C (PLC/PKC) and adenylate cyclase/protein kinase A (AC/PKA) intracellular signalling pathways was investigated. Ghrelin receptor transcripts, ghs-r1a, are present in the majority of goldfish hepatic cells. Ghrelin induced the mRNA expression of the positive (gbmal1a, gclock1a) and negative (gper genes) elements of the main loop of the molecular clock machinery, as well as grev-erbα (auxiliary loop) in cultured liver. These effects were blocked, at least in part, by a ghrelin antagonist. Incubation of liver with a PLC inhibitor (U73122), a PKC activator (phorbol 12-myristate 13-acetate) and a PKC inhibitor (chelerythrine chloride) demonstrated that the PLC/PKC pathway mediates such ghrelin actions. Experiments with an AC activator (forskolin) and a PKA inhibitor (H89) showed that grev-erbα regulation could be due to activation of PKA. Taken together, the present results show for the first time in vertebrates a direct action of ghrelin on hepatic clock genes and support a role for this hormone as a temporal messenger in the entrainment of liver circadian functions.
Performing a hepatic timing signal: glucocorticoids induce gper1a and gper1b expression and repress gclock1a and gbmal1a in the liver of goldfish
(Journal of Comparative Physiology B, 2016) Sánchez Bretaño, Aída; Callejo, María; Montero, Marta; Alonso Gómez, Ángel L.; Delgado Saavedra, María Jesús; Isorna Alonso, Esther
Glucocorticoids have been recently proposed as input signals of circadian system, although the underlying molecular mechanism remains unclear. This work investigates the role of glucocorticoids as modulators of clock genes expression in the liver of goldfish. In fish maintained under a 12L:12D photoperiod, an intraperitoneal injection at Zeitgeber Time 2 of a glucocorticoid analog, dexamethasone (1 μg/g body weight) induced per1 genes while decreased gbmal1a and gclock1a expression in the liver at 8 h post-injection. A 4-h in vitro exposure of goldfish liver to cortisol (0.1–10 μM) also induced gper1 genes in a concentration-dependent manner. Similarly, the exposure of the goldfish cultured liver to dexamethasone produced a concentration-dependent induction of gper1 genes. Moreover, this glucocorticoid analog led to a decrease in gbmal1a and gclock1a transcripts, while the other clock genes analyzed were unaffected. The induction of gper1a and gper1b by dexamethasone in vitro was observed at short times (2 h), whereas the reductions of gbmal1a and gclock1a transcripts needed longer exposure times (8 h) to the glucocorticoid to be significant. Additionally, a 2-h exposure to dexamethasone in the liver culture was enough to extend the induction of per genes for more than 12 h. Present results indicate that gper1 genes are targets for glucocorticoids in the regulation of goldfish hepatic oscillator, as previously reported in mammals, suggesting a conserved role of glucocorticoids in the functional organization of the peripheral circadian system in vertebrates. The repression of clock1a and bmal1a is not so well established, and suggests that other clock genes could be glucocorticoid targets in the goldfish liver.
REV-ERBα Agonist SR9009 Promotes a Negative Energy Balance in Goldfish
(International Journal of Molecular Sciences, 2022) Saiz, Nuria; Herrera Castillo, Lisbeth; Isorna Alonso, Esther; Delgado Saavedra, María Jesús; Conde Sieira, Marta; Soengas, José L.; Pedro Ormeño, Nuria de
REV-ERBα (nr1d1, nuclear receptor subfamily 1 group D member 1) is a transcriptional repressor that in mammals regulates nutrient metabolism, and has effects on energy homeostasis, although its role in teleosts is poorly understood. To determine REV-ERBα’s involvement in fish energy balance and metabolism, we studied the effects of acute and 7-day administration of its agonist SR9009 on food intake, weight and length gain, locomotor activity, feeding regulators, plasma and hepatic metabolites, and liver enzymatic activity. SR9009 inhibited feeding, lowering body weight and length gain. In addition, the abundance of ghrelin mRNA decreased in the intestine, and abundance of leptin-aI mRNA increased in the liver. Hypocretin, neuropeptide y (npy), and proopiomelanocortin (pomc) mRNA abundance was not modified after acute or subchronic SR9009 administration, while hypothalamic cocaine- and amphetamine-regulated transcript (cartpt-I) was induced in the subchronic treatment, being a possible mediator of the anorectic effects. Moreover, SR9009 decreased plasma glucose, coinciding with increased glycolysis and a decreased gluconeogenesis in the liver. Decreased triglyceride levels and activity of lipogenic enzymes suggest a lipogenesis reduction by SR9009. Energy expenditure by locomotor activity was not significantly affected by SR9009. Overall, this study shows for the first time in fish the effects of REV-ERBα activation via SR9009, promoting a negative energy balance by reducing energetic inputs and regulating lipid and glucose metabolism.
Students and Teachers Using Mentimeter: Technological Innovation to Face the Challenges of the COVID-19 Pandemic and Post-Pandemic in Higher Education
(Education Sciences, 2021) Pichardo Galán, José Ignacio; López Medina, Esteban F.; Mancha Cáceres, Olga Inmaculada; González Enríquez, Isabel; Hernández Melián, Alejandro Domingo; Blázquez Rodríguez, María Isabel; Jiménez Rodríguez, Virginia; Logares Jiménez, Marina Lucía; Carabantes Alarcón, David; Ramos Toro, Mónica; Isorna Alonso, Esther; Cornejo Valle, Mónica; Borras Gené, Oriol
The COVID-19 pandemic has prompted higher university lecturers to develop their digital skills in order to adapt to online teaching. A group of university teachers decided to evaluate the educational uses of Mentimeter to promote student participation and active learning. A questionnaire was answered by 400 students and 12 participating academics. These 12 academic respondents also participated in a focus group after experiencing this software during an academic course. Qualitative and quantitative data was collected and analyzed to conclude that this software not only facilitated student participation during the pandemic (both face-to-face and online) in synchronous and asynchronous ways but also improved attention, engagement, collaborative learning and interaction. Immediate feedback made it possible for teachers to monitor the students’ learning processes and to adjust the content and pace accordingly. Students and educators highlighted the inclusive potential of this tool, as it allows participation from a diverse audience with different backgrounds and capacities, ensuring inclusive and equitable education for all. Some opportunities for improvement were also identified, namely more functions to make the software more attractive and adapt it to different educational objectives.
El uso de Mentimeter para promover la participación del alumnado en el aula y en el Campus Virtual
(Jornada «Aprendizaje Eficaz con TIC en la UCM», 2022) Borras Gené, Oriol; Pichardo Galán, José Ignacio; Blázquez Rodríguez, María Isabel; Mancha Cáceres, Olga Inmaculada; González Enríquez, Isabel; Jiménez Rodríguez, Virginia; Isorna Alonso, Esther; Carabantes Alarcón, David; Cornejo Valle, Mónica; Hernández Melián, Alejandro Domingo; Logares Jiménez, Marina Lucía; López Medina, Esteban Francisco; Ramos Toro, Mónica
La herramienta de software online (SaaS) Mentimeter tiene un gran potencial para promover y facilitar el aprendizaje colaborativo, ya que posibilita la participación simultanea del alumnado de una forma gratuita, sencilla y anónima a través de su propio móvil, tableta u ordenador. El profesorado participante docente ha utilizado este recurso como herramienta innovadora tanto de forma presencial como en línea, con carácter sincrónico y asincrónico. Los resultados del cuestionario distribuido entre el alumnado y el profesorado que han utilizado Mentimeter corroboran su utilidad y éxito para mejorar los procesos de enseñanza y aprendizaje.
Anatomical distribution and daily profile of gper1b gene expression in brain and peripheral structures of goldfish (Carassius auratus)
(Chronobiology International, 2015) Sánchez Bretaño, Aída; Gueguen, Marie-M.; Cano-Nicolau, Joel; Kah, Olivier; Alonso Gómez, Ángel Luis; Delgado Saavedra, María Jesús; Isorna Alonso, Esther
The functional organization of the circadian system and the location of the main circadian oscillators vary through phylogeny. Present study investigates by in situ hybridization the anatomical location of the clock gene gPer1b in forebrain and midbrain, pituitary, and in two peripheral locations, the anterior intestine and liver, in a teleost fish, the goldfish (Carassius auratus). Moreover, the daily expression profiles of this gene were also studied by quantitative Real Time-PCR. Goldfish were maintained under a 12L–12D photoperiod and fed daily at 2 h after lights were switched on. A wide distribution of gPer1b mRNA in goldfish brain and pituitary was found in telencephalon, some hypothalamic nuclei (including the homologous to mammalian SCN), habenular nucleus, optic tectum, cerebellum and torus longitudinalis. Moreover, gPer1b expression was observed, for the first time in teleosts, in the pituitary, liver and anterior intestine. Day/night differences in gper1b mRNA abundance were found by in situ hybridization, with higher signal at nighttime that correlates with the results obtained by RT-PCR, where a rhythmic gPer1b expression was found in all tissues with acrophases at the end of the night. Amplitudes of gper1b rhythms vary among tissues, being higher in liver and intestine than in the brain, maybe because different cues entrain clocks in these locations. These results support the existence of functional clocks in many central and peripheral locations in goldfish coordinated, ticking at the same time.