Lluis Tort

Autonomous University of Barcelona | UAB · Dpt. Cell Biology, Physiology and Immunology

When necessary, sea turtles are held captive for veterinarian care and research purposes. Protocols and basic guidelines have been described for husbandry of sea turtles with veterinarian needs but not considering physiological indicators of animal welfare. Because all sea turtle are imperiled species, monitoring their welfare is important. The aim...

Introduction: Under climate change, the increase in temperature in aquatic environments may induce oxygen depletion. In extreme cases, low oxygen may become a limiting factor for fish, thus generating stress. In addition, consecutive hypoxic episodes may complicate the recovery of individuals and hinder their ability to modulate physiological and b...

The widespread use of pesticides in some areas where fish species such as tilapia are farmed may cause damage to the environment and affect commercial fish and therefore, human health. Water leaching with the pesticide trichlorfon, during the fumigation season in the field, can affect water quality in fish farms and consequently affect fish health....

The present study explores the effects of two supplementation levels of Debaryomyces hansenii (1.1% and 2.2%) as a probiotic in a reference low fish meal-based diet on the skin mucosal tissue in Sparus aurata. This study includes the evaluation of fish performance coupled with a holistic study of the skin mucosa: i) a transcriptomic study of the sk...

Background: The development of a sustainable business model with social acceptance, makes necessary to develop new strategies to guarantee the growth, health, and well-being of farmed animals. Debaryomyces hansenii is a yeast species that can be used as a probiotic in aquaculture due to its capacity to i) promote cell proliferation and differentia...

In this study, we investigated the effects of the artificial photoperiods that mimic summer (16L:8D) and winter (8L:16D) solstices, equinoxes (12L:12D), and the artificial 24-h light regimen (24L:0D) on the leukocyte populations and the T helper and regulatory type responses on rainbow trout (Oncorhynchus mykiss). Using flow cytometry analysis, we...

The bulk of plastic pollution is mainly composed of small fragments, micro-and nanoplastics (NPs). Although many studies are currently published on NPs, research on the effects of NPs in fish after a chronic exposure is still scarce. The present study aimed to validate a series of automated assays to be used in the monitoring of fish challenged wit...

The most documented fibrates are gemfibrozil, clofibrate and bezafibrate, while for statins, the majority of the published literature focuses on atorvastatin and simvastatin. The present work reviews previously published research concerning the effects of these hypocholesterolaemic pharmaceuticals on fish, with a particular focus on commercially im...

The melanocortin system is an ancient neuroendocrine system conserved from teleosts to mammals. The melanocortin system is a set of complex neuroendocrine signaling pathways involved in numerous physiological processes, and particularly associated with the hypothalamic-pituitary-interrenal (HPI) axis response. The melanocortin 1 receptor (MC1R) is...

The insertion/deletion in the DNA-binding region allows the discrimination and subsequent identification of the glucocorticoid receptor 1 (gr1) and gr2 nucleotide sequences in gilthead sea bream (Sparus aurata): Standardizing the gr nomenclature for a better understanding of the stress response in teleost fish species Cortisol carries out its physi...

Overcoming a stress situation, such as hypoxia episodes, which involve an allostatic load, will depend 13 on the ability of fish to modulate physiological and biochemical systems to maintain homeostasis. The 14 aim of the study was to determine the integrated stress response after acute hypoxia of rainbow trout 15 considering the different elements...

The perception of an acute stressor (short-duration; high-intensity) induces a physiological response that activates the hypothalamic-pituitary-interrenal (HPI) axis and the subsequent release of cortisol. Cortisol carries out its effect at the molecular level through its recognition by the mineralocorticoid receptor (MR) and the glucocorticoid rec...

Circadian rhythms are present in all living organisms, participating in many physiological regulations including immune, stress and anti-oxidant responses. However, in fish the mutual influences between immune and circadian systems, either in wild or farmed scenarios, are still poorly analyzed. In farmed fish, vaccination strategies rely on memory...

Global warming is predicted to increase prolonged thermal challenges for aquatic ectotherms, i.e. it causes metabolic performance declines, impacts food intake, and finally causes impaired growth. In this research work, we investigated whether a tropical fish, Danio rerio (zebrafish), could tolerate prolonged thermal challenges and whether the temp...

[This corrects the article DOI: 10.3389/fmicb.2022.852677.].

Skin mucus is a non-lethal and low-invasive matrix appropriate to assess fish welfare as it contributes to their defence against external aggressions and reflects changes in fish health status. However, more information on the response of this matrix to specific stressors is needed. In this study, rainbow trout (Oncorhynchus mykiss) specimens were...

Vibrio vulnificus is a marine zoonotic pathogen associated with fish farms that is considered a biomarker of climate change. Zoonotic strains trigger a rapid death of their susceptible hosts (fish or humans) by septicemia that has been linked to a cytokine storm in mice. Therefore, we hypothesize that V. vulnificus also causes fish death by trigger...

The stress response in fish is characterized by the activation of the HPI axis resulting in the release of cortisol. Previous studies in rainbow trout (Oncorhynchus mykiss) and gilthead sea bream (Sparus aurata) have shown that an acute stressor modulates the expression of immune- and stress-related genes in mucosal-associated lymphoid tissues (MAL...

The spray-dried porcine plasma (SDPP) is an abattoir by-product used in animal nutrition with beneficial effects reported in livestock and commercial aquatic species. Previous results have found that the dietary inclusion of SDPP in gilthead sea bream (Sparus aurata) increased the density of intestinal goblet cells, and it did not result in signifi...

The transcriptomic response of the head kidney, the main lymphohematopoietic tissue of the body, was evaluated in Atlantic salmon (Salmo salar) smolts fed a functional feed containing a phytogenic rich in verbascoside and triterpenic compounds like ursolic acid. Fish (initial body weight = 55.0 ± 0.1 g) were fed two experimental diets (40% crude pr...

Fish inhabit microbial- and parasite-enriched environments that constrict the adaptive choices and evolutionary pathways of regulatory physiological systems. Teleost immune architecture reflects those selective pressures, and the modulation of immune performance by glucocorticoids and other mediators of perceived stress have sculpted the type, inte...

Polymethylmethacrylate (PMMA) plastic fragments have been found abundant in the environment, but the knowledge regarding its effects on the physiology of aquatic animals is still poorly studied. Here the short-term (96 h) effects of waterborne exposure to PMMA nanoplastics (PMMA-NPs) on the muscle of gilthead sea bream (Sparus aurata) fingerlings w...

In the present study, the modulation of the transcriptional immune response (microarray analysis) in the head kidney (HK) of the anadromous fish Atlantic salmon (Salmo salar) fed a diet supplemented with an olive fruit extract (AQUOLIVE®) was evaluated. At the end of the trial (133 days), in order to investigate the immunomodulatory properties of t...

The feeding behavior in fish is a complex activity that relies on the ability of the brain to integrate multiple signals to produce appropriate responses in terms of food intake, energy expenditure, and metabolic activity. Upon stress cues including viral infection or mediators such as the proinflammatory cytokines, prostaglandins, and cortisol, bo...

The association of vaccines with immunostimulants such as β-glucan, promote the production of cytokines, competent immune cells and antibodies. However, differences between β-glucan types and trials make it difficult to understand β-glucan's mechanism of action. In this study, three trials were carried out with control and fish fed β-glucan, the fi...

The effects of porcine plasma protein hydrolysate (PPH) on growth, feed efficiency, and immune responses was evaluated in Sparus aurata. Fish were fed two isoproteic (48% protein), isolipidic (17% fat), and isoenergetic diets (21.7 MJ/kg) diets, one of them containing 5% PPH at the expense of fishmeal. Both diets were tested for 92 days. A signific...

β-glucans are prebiotic and/or food additives used by the aquaculture industry to enhance the immune response of fish. Their efficiency may vary according to their origin and structure. In this study, the immunostimulant effects of two β-glucan types extracted from wild-type baker’s yeast (Saccharomyces cerevisiae) and its null-mutant Gas1 were inv...

Las partículas de plástico de pequeño tamaño (microplásticos - MPs y nanoplásticos - NPs) son consideradas contaminantes emergentes, por lo que han motivado recientes investigaciones para establecer sus consecuencias ambientales. La dorada (Sparus aurata) es una especie común en el mar Mediterráneo y es de las especies piscícolas más cultivadas en...

The inclusion of a medicinal plant leaf extract (MPLE) from sage (Salvia officinalis) and lemon verbena (Lippia citriodora), rich in verbascoside and triterpenic compounds like ursolic acid, was evaluated in gilthead seabream (Sparus aurata) fed a low fishmeal-based diet (48% crude protein, 17% crude fat, 21.7 MJ kg-1, 7% fishmeal, 15% fish oil) fo...

One of the main targets for the use of phytogenics in aquafeeds is the mucosal tissues as they constitute a physical and biochemical shield against environmental and pathogenic threats, comprising elements from both the innate and acquired immunity. In the present study, the modulation of the skin transcriptional immune response, the bacterial grow...

In aquaculture, biofouling management is a difficult and expensive issue. Cuprous oxide has been commonly used to prevent fouling formation. To cheapen net management and reduce the use of copper, the industry has proposed several alternatives. Currently, polyurethane coatings are being explored and commercially implemented. With this alternative,...

Essential oils (EOs) are promising alternatives to chemotherapeutics in animal production due to their immunostimulant, antimicrobial, and antioxidant properties, without associated environmental or hazardous side effects. In the present study, the modulation of the transcriptional immune response (microarray analysis) and microbiota [16S Ribosomal...

From a general structural perspective, a mucosal tissue is constituted by two main matrices: the tissue and the secreted mucus. Jointly, they fulfill a wide range of functions including the protection of the epithelial layer. In this study, we simultaneously analyzed the epithelial tissue and the secreted mucus response using a holistic interactome...

Fish welfare in aquaculture – problems and approaches to solutions. Free download: http://www.ign-nutztierhaltung.ch/sites/default/files/Bilder/IGN_FOKUS20_Broschuere_Fischwohl_100Seiter_web.pdf (The English edition will be available in late spring 2021.)

A microencapsulated feed additive composed by garlic, carvacrol and thymol essential oils (EOs) was evaluated regarding its protective effect in gills parasitized by Sparicotyle chrysophrii in Sparus aurata. A nutritional trial (65 days) followed by a cohabitation challenge with parasitized fish (39 days) were performed. Transcriptomic analysis by...

This study evaluated the effect of a short-term exposure to 45 nm polymethylmethacrylate nanoplastics (PMMA-NPs) on the gilthead seabream (Sparus aurata), by assessing biomarkers at different levels of biological organization in liver and plasma. Fish were exposed via water to PMMA-NPs (0, 0.001, 0.01, 0.1, 1 and 10 mg L⁻¹) and sampled after 24 and...

The presence of small-sized plastic particles in marine and freshwater environments is a global problem but their long-term impact on ecosystems and human health is still far from being understood. Nanoplastics (<1000 nm) could pose a real and uncontrolled ecological challenge due to their smaller size and sharp ability to penetrate living organism...

Nodavirus, or nervous necrosis virus (NNV ), is the causative agent of viral encephalopathy and retinopathy (VER), a severe disease affecting numerous fish species worldwide. European sea bass, a cultured species of great economic importance, is highly susceptible to the disease. To better understand the response of this organism to NNV, we conduct...

Plastics materials rarely biodegrade, instead, through different biotic and abiotic processes, they fragment into smaller microplastics (<5 mm, MPs), which have already been reported as ubiquitous pollutants in marine environments worldwide, as well as in a wide range of marine organisms [1]. Nanoplastics (NPs), the smaller than 100/1000 nm fractio...

Small plastic particles are considered emerging pollutants, and this has motivated research to establish their ecological and environmental consequences. Currently, the study of the effects of nanoplastics (NPs) in aquatic organisms is still scarce, especially in organisms of higher trophic levels, such as fish.

Cortisol is the main corticosteroid in teleosts, exerting multiple functions by activating glucocorticoid receptors (GR). Most teleost species have two GR genes, gr-1 and gr-2. Some teleost also presents two splice variants for gr-1; gr-1a and gr-1b. In this study, we report for first time the presence of 2 homeologous genes for gr-1 and gr-2, loca...

In the present study, we evaluated the effects of a medicinal plant leaf extract (MPLE; 10%, ursolic acid, 3% other triterpenic compounds; 2% verbascoside and < 1% polyphenols) obtained from Lippia citriodora and Salvia officinalis on somatic growth and immune responses in juvenile gilthead seabream (Sparus aurata). Fish (initial body weight = 26.0...

Single-nucleotide polymorphisms (SNPs) are single genetic code variations considered one of the most common forms of nucleotide modifications. Such SNPs can be located in genes associated to immune response and, therefore, they may have direct implications over the phenotype of susceptibility to infections affecting the productive sector. In this s...

Small plastic particles are considered emerging pollutants, and this has motivated a considerable number of studies to establish their environmental consequences. At present, the study of the effects of nanoplastics (NPs) on aquatic organisms is still scarce, especially in organisms from higher trophic levels such as fish. This review describes the...

The current overview is presented regarding the biological investigations being carried out in fish to determine whether these animals are sentient beings with capacity to perceive stress and pain. After realising the wide biological diversity and describing the neural equipment and cognitive abilities, the current state of the scientific controver...

https://www.frontiersin.org/articles/10.3389/fendo.2019.00652/full

Vaccination is a widely used therapeutical strategy in aquaculture, but whether vaccination elicits stress responses in the central neuroendocrine system and enhances the crosstalk between the immune and endocrine systems in the brain or pituitary after vaccination is unclear. To answer this question two experiments using two different vaccine expo...

Vibrio vulnificus is a siderophilic pathogen spreading due to global warming. The zoonotic strains constitute a clonal‐complex related to fish farms that are distributed worldwide. In this study, we applied a transcriptomic and single gene approach and discover that the zoonotic strains bypassed the iron requirement of the species thanks to the acq...

The use of anesthesia is a common practice in aquaculture to sedate fish and mitigate handling stress. Although the employ of anesthesia is considered beneficial for fish, as it reduces stress and improves welfare, at the same time it may induce hazardous side-effects. The aim of the present study was to investigate the effects of clove oil (CO) an...

In the present study, the underlying short-term effects of gold nanoparticles (AuNP, spheres, citrate coated, ∼40 nm) on the hepatic function of gilthead sea bream (Sparus aurata) was assessed, using a species-specific enriched oligonucleotide microarray platform (SAQ). Two distinct concentrations of AuNP (0.5 and 50 μg/L) were tested during 24 h w...

Cortisol, the end product of the hypothalamus-pituitary-interrenal (HPI) axis, has been traditionally measured in blood as indicator of stress in fish, however, the degree of invasiveness inherent to blood collection is not always possible or desirable. Instead, cortisol measurement in skin mucus is far less invasive, but as blood, this method pote...

In the last decade, the concept of animal stress has been stressed thin to accommodate the effects of short-term changes in cell and tissue physiology, major behavioral syndromes in individuals and ecological disturbances in populations. Seyle's definition of stress as “the nonspecific (common) result of any demand upon the body” now encompasses ho...

The pituitary is a central organ of the neuro-endocrine system in fish that plays critical roles in various physiological processes, including stress response and behavior. Although it is known that pituitary hormones can have a direct or indirect influence stimulating or suppressing the immune responses, whether there is a local immune response in...

The aims of the present study were to validate an automated chemiluminescence assay (CIA) for cortisol determination in plasma and skin mucus of fish, to compare the results produced with those obtained by radio-immunoassay (RIA), and to evaluate the assay capacity to differentiate between stressed and non-stressed fish. Cortisol hormone was measur...

Fish are ectotherm organisms that move through different thermal zones according to their physiological requirements and environmental availability, a behavior known as thermoregulation. Thermoregulation in ectothermic animals is influenced by their ability to effectively respond to thermal variations. While it is known that ectotherms are affected...

Abstract Environmental insults, such as exposure to pathogens, modulate the behavioural coping style of animals to stressors, and repeated exposure to stressful environments may lead to species-specific infection phenotypes. To analyse the influence of stress behavioural phenotypes on immune and metabolic performance, gilthead sea bream (Sparus aur...

Reproductive steroid concentration and gonadal development as well as plasma cortisol were investigated during the reproductive period (April to October) of the Pacific red snapper Lutjanus Peru, a commercial and important local fishery species in the surrounding areas of Bahía La Paz, Gulf of California, Mexico. Gonads in April were immature and c...

The stress and immune-related effects of short-term (1, 6 and 24 h) air exposure stress (1 min), bath vaccination with Vibrio anguillarum bacterin, and both stressors combined were evaluated in liver and spleen of Sparus aurata, Danio rerio and Onchorhynchus mykiss. Expression profiles of immune (interleukin 1 beta: il1β; tumor necrosis factor alph...

The present study aimed to evaluate the effects of ~45 nm nanoplastics (NPs) on the marine fish Dicentrarchus labrax after a short-term exposure. Animals were exposed to a concentration range of NPs for 96 h and liver, plasma and skin mucus sampled. Assessed endpoints included biochemical biomarkers and expression of genes related to lipid metaboli...

The effects of two new anesthetics (essential oils) extracted from oregano (OO) and eucalyptus (EO) plants were studied in European sea bass (Dicentrarchus labrax) stress response and welfare parameters in comparison to the effects of clove oil (CO) that is one of the most used anesthetics in aquaculture. A time-course study on evolution of plasma...

This study aimed to assess antioxidant and immune gene transcription alterations in the gills of Sparus aurata exposed during 96 h to 4, 80, and 1600 μg/L of gold nanoparticles (AuNPs) coated with citrate or polyvinyl pyrrolidone (PVP). After 96 h of exposure, gr and cat mRNA levels decreased for all tested concentrations of AuNPs, for both coating...

In recent years, the innate immune response has gained importance since evidence indicates that after an adequate priming protocol, it is possible to obtain some prolonged and enhanced immune responses. Nevertheless, several factors, such as the timing and method of administration of the immunostimulants, must be carefully considered. An inappropri...

Plastic pollution is a worldwide problem, highlighted by the fact that plastic materials degrade into nano-size particles (<100 nm), potentially becoming more bioavailable as well as a source of entry of other contaminants into organisms. The present study aimed to assess the effects of polystyrene nanoplastics (PS), individually or combined with c...

Gold nanoparticles (AuNP) effects on Sparus aurata were evaluated on skin, gills and intestine by assessing the expression of immune genes and in peripheral blood evaluating genetic damage. Fish were exposed to 0.5 and 50 μg/L AuNP for 96 h. Results showed that exposure to 50 μg/L AuNP induced an upregulation in the expression of innate immune gene...

Although several efforts have been made to describe the immunoendocrine interaction in fish, there are no studies to date focusing on the characterization of the immune response and glucocorticoid synthesis using the host–pathogen interaction on larval stage as an early developmental stage model of study. Therefore, the aim of this study was to eva...

Fish have to face various environmental challenges that may compromise the efficacy of the immune response in mucosal surfaces. Since the effect of acute stress on mucosal barriers in fish has still not been fully elucidated, we aimed to compare the short-term mucosal stress and immune transcriptomic responses in a freshwater (rainbow trout, Oncorh...

Rhodomyrtus tomentosa is a medicinal plant that shows biological effects including immunomodulatory activity on human and other mammals but not in fish. In this study, we evaluated the in vitro immunomodulatory effects of R. tomentosa leaf extract and its active compound, rhodomyrtone, on the immune responses, using rainbow trout (Oncorhynchus myki...

The inflammatory reflex modulates the innate immune system, keeping in check the detrimental consequences of overstimulation. A key player controlling the inflammatory reflex is the alpha 7 acetylcholine receptor (α7nAChR). This receptor is one of the signalling molecules regulating cytokine expression in macrophages. In this study, we characterize...

The immunostimulatory effects of Rhodomyrtus tomentosa leaf extract were evaluated in rainbow trout through changes in expression profile of genes involved in innate immune and antioxidant response, hematology and stress indicators. The concentrations of R. tomentosa at 10 and 100 μg per fish were administrated by intraperitoneal injection, alone o...

A fever, or increased body temperature, is a symptom of inflammation, which is a complex defence reaction of the organism to pathogenic infections. After pathogens enter the body, immune cells secrete a number of agents, the functions of which stimulate the body to develop a functional immune and fever response. In mammals it is known that PGE2is t...

Physiological mechanisms driving stress response in vertebrates are evolutionarily conserved. These mechanisms involve the activation of both the hypothalamic-sympathetic-chromaffin cell (HSC) and the hypothalamic-pituitary-adrenal (HPA) axes. In fish, the reduction of food intake levels is a common feature of the behavioral response to stress but...

There is an increasing need to assess animal welfare and subtle alterations that may indicate the presence of environmental stressors. Among the most widely used endpoints are the assessment of the activities of specific enzymes and the alterations of the expression levels of target genes. Enzymes associated with oxidative stress are frequently ass...