Examinando por Autor "Zuloaga, Rodrigo"
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Ítem 11-Deoxycorticosterone (DOC)’s Action on the Gill Osmoregulation of Juvenile Rainbow Trout (Oncorhynchus mykiss)(MDPI, 2024-02-02) Zuloaga, Rodrigo; Ahumada-Langer, Luciano; Aedo, Jorge Eduardo; Molina, Alfredo; Valdés, Juan AntonioIn aquaculture, stress can negatively affect fish growth. For years, the cortisol hormone has been thought to play both glucocorticoid and mineralocorticoid functions. Nevertheless, recent research has suggested that 11-deoxycorticosterone (DOC) released during stress could contribute to cortisol actions, though this process is still misunderstood. Here, we evaluated the DOC effects on physiological and early transcriptional responses by RNA-seq. Juvenile rainbow trout were treated with DOC and/or glucocorticoids (mifepristone) or mineralocorticoid (eplerenone) receptor antagonists. Subsequently, plasma was collected, and cDNA libraries were generated from the gills of vehicle (control), DOC, mifepristone, mifepristone with DOC, eplerenone, and eplerenone with DOC groups. Calcium and phosphate levels in plasma were changed. Results revealed 914 differentially expressed transcripts (DETs) induced by DOC compared with control, mainly associated with sodium ion transmembrane transport, gluconeogenesis, negative regulation of transmembrane transport, and activation of innate immune response. DOC versus eplerenone with DOC comparison displayed 444 DETs related to cell-cell junction organization, canonical glycolysis, positive regulation of immune response, and potassium ion transport. Conversely, no DETs were detected in DOC versus mifepristone with DOC comparison. These data suggest that DOC has a relevant role in gill stress response and ion transport, which is differentially regulated by mineralocorticoid receptors.Ítem Chronic stress inhibits growth and induces proteolytic mechanisms through two different nonoverlapping pathways in the skeletal muscle of a teleost fish(American Physiological Society, 2018-06) Valenzuela, Cristián A.; Zuloaga, Rodrigo; Mercado, Luis; Einarsdottir, Ingibjörg Eir; Björnsson, Björn Thrandur; Valdés, Juan Antonio; Molina, AlfredoChronic stress detrimen-tally affects animal health and homeostasis, with somatic growth, and thus skeletal muscle, being particularly affected. A detailed understanding of the underlying endocrine and molecular mechanisms of how chronic stress affects skeletal muscle growth remains lacking. To address this issue, the present study assessed primary (plasma corti-sol), secondary (key components of the GH/IGF system, muscular proteolytic pathways, and apoptosis), and tertiary (growth perfor-mance) stress responses in fine flounder (Paralichthys adspersus) exposed to crowding chronic stress. Levels of plasma cortisol, glucocorticoid receptor 2 (gr2), and its target genes (klf15 and redd1) mRNA increased significantly only at 4 wk of crowding (P < 0.05). The components of the GH/IGF system, including ligands, receptors, and their signaling pathways, were significantly downregulated at 7 wk of crowding (P < 0.05). Interestingly, chronic stress upregulated the ubiquitin-proteasome pathway and the intrinsic apoptosis pathways at 4wk (P < 0.01), whereas autophagy was only significantly activated at 7 wk (P < 0.05), and meanwhile the ubiquitin-proteasome and the apoptosis pathways returned to control levels. Overall growth was inhibited in fish in the 7-wk chronic stress trial (P < 0.05). In conclusion, chronic stress directly affects muscle growth and down-regulates the GH/IGF system, an action through which muscular catabolic mechanisms are promoted by two different and nonoverlapping proteolytic pathways. These findings provide new information on molecular mechanisms involved in the negative effects that chronic stress has on muscle anabolic/catabolic signaling balance. © 2018 American Physiological Society. All rights reserved.Ítem De novo assembly and analysis of tissue-specific transcriptomes of the edible red sea urchin loxechinus albus using rna-seq(MDPI, 2021-09) Antiqueo, Paulette; Zuloaga, Rodrigo; Bastias-Molina, Macarena; Meneses, Claudio; Estrada, Juan Manuel; Molina, Alfredo; Valdés, Juan AntonioEdible red sea urchin (Loxechinus albus) is an endemic echinoderm species of the Chilean coasts. The worldwide demand for high-quality gonads of this species has addressed the depletion of its natural populations. Studies on this sea urchin are limited, and genomic information is almost nonexistent. Hence, generate a transcriptome is crucial information that will considerably enrich molecular data and promote future findings for the L. albus aquaculture. Here, we obtained transcriptomic data of the edible red sea urchin by Illumina platform. Total RNA was extracted from gonads, intestines, and coelomocytes of juvenile urchins, and samples were sequenced using MiSeq Illumina technology. A total of 91,119,300 paired-end reads were de novo assembled, 185,239 transcripts produced, and a reference transcriptome created with 38.8% GC content and an N50 of 1769 bp. Gene ontology analysis revealed notable differences in the expression profiles between gonads, intestines, and coelomocytes, allowing the detection of transcripts associated with specific biological processes and KEGG pathways. These data were validated using 12 candidate transcripts by real-time qPCR. This dataset will provide a valuable molecular resource for L. albus and other species of sea urchins. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Ítem Effect of 11-Deoxycorticosterone in the Transcriptomic Response to Stress in Rainbow Trout Skeletal Muscle(MDPI, 2023-02) Zuloaga, Rodrigo; Aravena-Canales, Daniela; Aedo, Jorge Eduardo; Osorio-Fuentealba, Cesar; Molina, Alfredo; Valdés, Juan AntonioIn aquaculture, many stressors can negatively affect growth in teleosts. It is believed that cortisol performs glucocorticoid and mineralocorticoid functions because teleosts do not synthesize aldosterone. However, recent data suggest that 11-deoxycorticosterone (DOC) released during stress events may be relevant to modulate the compensatory response. To understand how DOC modifies the skeletal muscle molecular response, we carried out a transcriptomic analysis. Rainbow trout (Oncorhynchus mykiss) were intraperitoneally treated with physiological doses of DOC in individuals pretreated with mifepristone (glucocorticoid receptor antagonist) or eplerenone (mineralocorticoid receptor antagonist). RNA was extracted from the skeletal muscles, and cDNA libraries were constructed from vehicle, DOC, mifepristone, mifepristone plus DOC, eplerenone, and eplerenone plus DOC groups. The RNA-seq analysis revealed 131 differentially expressed transcripts (DETs) induced by DOC with respect to the vehicle group, mainly associated with muscle contraction, sarcomere organization, and cell adhesion. In addition, a DOC versus mifepristone plus DOC analysis revealed 122 DETs related to muscle contraction, sarcomere organization, and skeletal muscle cell differentiation. In a DOC versus eplerenone plus DOC analysis, 133 DETs were associated with autophagosome assembly, circadian regulation of gene expression, and regulation of transcription from RNA pol II promoter. These analyses indicate that DOC has a relevant function in the stress response of skeletal muscles, whose action is differentially modulated by GR and MR and is complementary to cortisol. © 2023 by the authors.Ítem Effects of crowding on the three main proteolytic mechanisms of skeletal muscle in rainbow trout (Oncorhynchus mykiss)(BioMed Central Ltd, 2020-08) Valenzuela, Cristián A.; Ponce, Claudia; Zuloaga, Rodrigo; González, Pamela; Avendaño-Herrera, Ruben; Valdés, Juan A.; Molina, AlfredoBackground: Skeletal muscle is one of the tissues most affected by stress conditions. The protein degradation in this tissue is vital for the supply of energy mediated by different proteolytic pathways such as the ubiquitin-proteasome (UPS), autophagy-lysosome (ALS) and the calpain/calpastatin system (CCS). Nevertheless, the regulation of this proteolytic axis under stress conditions is not yet completely clear. Chile is the main producer of rainbow trout (Oncorhynchus mykiss) in the world. This intensive fish farming has resulted in growing problems as crowding and stress are one of the major problems in the freshwater stage. In this context, we evaluated the crowding effect in juvenile rainbow trout kept in high stocking density (30 kg/m3) for 15, 45 and 60 days, using a control group of fish (10 kg/m3). Results: Plasmatic cortisol and glucose were evaluated by enzyme immunoassay. The mRNA levels of stress-related genes (gr1, gr2, mr, hsp70, klf15 and redd1), markers of the UPS (atrogin1 and murf1) and CCS (capn1, capn1, cast-l and cast-s) were evaluated using qPCR. ALS (LC3-I/II and P62/SQSTM1) and growth markers (4E-BP1 and ERK) were measured by Western blot analysis. The cortisol levels increased concomitantly with weight loss at 45 days of crowding. The UPS alone was upregulated at 15 days of high stocking density, while ALS activation was observed at 60 days. However, the CCS was inactivated during the entire trial. Conclusion: All these data suggest that stress conditions, such as crowding, promote muscle degradation in a time-dependent manner through the upregulation of the UPS at early stages of chronic stress and activation of the ALS in long-term stress, while the CCS is strongly inhibited by stress conditions in the rainbow trout muscle farmed during freshwater stage. Our descriptive study will allow perform functional analysis to determine, in a more detailed way, the effect of stress on skeletal muscle physiology as well as in the animal welfare in rainbow trout. Moreover, it is the first step to elucidate the optimal crop density in the freshwater stage and improve the standards of Chilean aquaculture. © 2020 The Author(s).Ítem High‐Temperature Stress Effect on the Red Cusk‐Eel (Geypterus chilensis) Liver: Transcriptional Modulation and Oxidative Stress Damage(MDPI, 2022-06) Dettleff, Phillip; Zuloaga, Rodrigo; Fuentes, Marcia; Gonzalez, Pamela; Aedo, Jorge; Estrada, Juan Manuel; Molina, Alfredo; Valdés, Juan AntonioEnvironmental stressors, such as temperature, are relevant factors that could generate a negative effect on several tissues in fish. A key fish species for Chilean aquaculture diversification is the red cusk‐eel (Genypterus chilensis), a native fish for which knowledge on environmental stressors effects is limited. This study evaluated the effects of high‐temperature stress on the liver of red cusk‐eel in control (14 °C) and high‐temperature (19 °C) groups using multiple approaches: determination of plasmatic hepatic enzymes (ALT, AST, and AP), oxidative damage evaluation (AP sites, lipid peroxidation, and carbonylated proteins), and RNA‐seq analysis. High-temperature stress generated a significant increase in hepatic enzyme activity in plasma. In the liver, a transcriptional regulation was observed, with 1239 down‐regulated and 1339 up‐regulated transcripts. Additionally, high‐temperature stress generated oxidative stress in the liver, with oxidative damage and transcriptional modulation of the antioxidant response. Furthermore, an unfolded protein response was observed, with several pathways enriched, as well as a heat shock response, with several heat shock proteins up regulated, suggesting candidate biomarkers (i.e., serpinh1) for thermal stress evaluation in this species. The present study shows that high-temperature stress generated a major effect on the liver of red cusk‐eel, knowledge to consider for the aquaculture and fisheries of this species. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Ítem Role of glucocorticoid and mineralocorticoid receptors in rainbow trout (Oncorhynchus mykiss) skeletal muscle: A transcriptomic perspective of cortisol action(Frontiers Media S.A., 2023-01) Aedo, Jorge E.; Zuloaga, Rodrigo; Aravena-Canales, Daniela; Molina, Alfredo; Valdés, Juan AntonioCortisol is an essential regulator of neuroendocrine stress responses in teleost. Cortisol performs its effects through the modulation of glucocorticoid receptor (GR) and mineralocorticoid receptor (MR), activating gene expression. Until now the contribution of both receptors in the global transcriptional response in teleost skeletal muscle has not been explored. To understand in a comprehensive and global manner how GR and MR modulates the skeletal muscle transcriptomic response, we performed RNA-seq analysis. Juvenile rainbow trout (Oncorhynchus mykiss) pretreated with a suppressor of endogenous cortisol production were intraperitoneally injected with cortisol (10 mg/kg). We also included a treatment with mifepristone (GR antagonist) and eplerenone (MR antagonist) in the presence or absence of cortisol. cDNA libraries were constructed from the skeletal muscle of rainbow trout groups: vehicle, cortisol, mifepristone, eplerenone, mifepristone/cortisol and eplerenone/cortisol. RNA-seq analysis revealed that 135 transcripts were differentially expressed in cortisol vs. mifepristone/cortisol group, mainly associated to inflammatory response, ion transmembrane transport, and proteolysis. In the other hand, 68 transcripts were differentially expressed in cortisol vs. eplerenone/cortisol group, mainly associated to muscle contraction, and regulation of cell cycle. To validate these observations, we performed in vitro experiments using rainbow trout myotubes. In myotubes treated with cortisol, we found increased expression of cxcr2, c3, and clca3p mediated by GR, associated with inflammatory response, proteolysis, and ion transmembrane transport, respectively. Contrastingly, MR modulated the expression of myh2 and gadd45g mainly associated with muscle contraction and regulation of cell cycle, respectively. These results suggest that GR and MR have a differential participation in the physiological response to stress in teleost skeletal muscle. Copyright © 2023 Aedo, Zuloaga, Aravena-Canales, Molina and Valdés.