Conseqüències fisiològiques d'una activació del sistema immunitari sobre la reproducció i el creixement en peixos d'interès en aqüicultura

En peixos teleostis, una activació del sistema immunitari comporta la producció de factors immunitaris que ajuden a combatre una infecció i estableixen una comunicació entre la resposta immunitària innata i l'adaptativa. A part d'aquesta funció estrictament immunitària, els factors immunitaris poden afectar el funcionament d'altres cèl·lules i teixits no immunitaris. Dos processos particularment importants, tant per l'estat biològic d'una població de peixos, com per aspectes més relacionats amb la productivitat d'espècies en cultiu, són la reproducció i el creixement. En aquest treball es descriuen estudis encaminats a investigar els efectes d'una activació del sistema immunitari, i dels factors produïts, sobre la reproducció i el creixement en peixos teleostis.In teleost fish, an activation of the immune system entails the production of immune factors that are key to fighting an infeccion and establish a bridge between the innate and D’aquesthe adaptive immune responses. In addition to this strictly immune function, immune factors can also affect the function of other non-immune cells and tissues. Reproduction and growth are two processes that are particularly important for the biological condition of a population of fish as well as for aspects more related to productivity of cultured species. In this paper, we describe studies designed to investigate the effects of an activation of the immune system, as well as of the factors produced, on reproduction and growth in teleost fish

Conseqüències fisiológiques d'una activació del sistema immunitari sobre la reproducción i el creixement en peixos d'interés en aqüicultura

En peixos teleostis, una activació del sistema immunitari comporta la producció de factors immunitaris que ajuden a combatre una infecció i estableixen una comunicació entre la resposta immunitària innata i l'adaptativa. A part d'aquesta funció estrictament immunitària, els factors immunitaris poden afectar el funcionament d'altres cèl·lules i teixits no immunitaris. Dos processos particularment importants, tant per l'estat biològic d'una població de peixos, com per aspectes més relacionats amb la productivitat d'espècies en cultiu, són la reproducció i el creixement. En aquest treball es descriuen estudis encaminats a investigar els efectes d'una activació del sistema immunitari, i dels factors produïts, sobre la reproducció i el creixement en peixos teleostis.In teleost fish, an activation of the immune system entails the production of immune factors that are key to fighting an infeccion and establish a bridge between the innate and the adaptive immune responses. In addition to this strictly immune function, immune factors can also affect the function of other non-immune cells and tissues. Reproduction and growth are two processes that are particularly important for the biological condition of a population of fish as well as for aspects more related to productivity of cultured species. In this paper, we describe studies designed to investigate the effects of an activation of the immune system, as well as of the factors produced, on reproduction and growth in teleost fish

AMP-Activated Protein Kinase Plays an Important Evolutionary Conserved Role in the Regulation of Glucose Metabolism in Fish Skeletal Muscle Cells

AMPK, a master metabolic switch, mediates the observed increase of glucose uptake in locomotory muscle of mammals during exercise. AMPK is activated by changes in the intracellular AMP∶ATP ratio when ATP consumption is stimulated by contractile activity but also by AICAR and metformin, compounds that increase glucose transport in mammalian muscle cells. However, the possible role of AMPK in the regulation of glucose metabolism in skeletal muscle has not been investigated in other vertebrates, including fish. In this study, we investigated the effects of AMPK activators on glucose uptake, AMPK activity, cell surface levels of trout GLUT4 and expression of GLUT1 and GLUT4 as well as the expression of enzymes regulating glucose disposal and PGC1α in trout myotubes derived from a primary muscle cell culture. We show that AICAR and metformin significantly stimulated glucose uptake (1.6 and 1.3 fold, respectively) and that Compound C completely abrogated the stimulatory effects of the AMPK activators on glucose uptake. The combination of insulin and AMPK activators did not result in additive nor synergistic effects on glucose uptake. Moreover, exposure of trout myotubes to AICAR and metformin resulted in an increase in AMPK activity (3.8 and 3 fold, respectively). We also provide evidence suggesting that stimulation of glucose uptake by AMPK activators in trout myotubes may take place, at least in part, by increasing the cell surface and mRNA levels of trout GLUT4. Finally, AICAR increased the mRNA levels of genes involved in glucose disposal (hexokinase, 6-phosphofructokinase, pyruvate kinase and citrate synthase) and mitochondrial biogenesis (PGC-1α) and did not affect glycogen content or glycogen synthase mRNA levels in trout myotubes. Therefore, we provide evidence, for the first time in non-mammalian vertebrates, suggesting a potentially important role of AMPK in stimulating glucose uptake and utilization in the skeletal muscle of fish

AMP-activated protein kinase plays an important evolutionary conserved role in the regulation of glucose metabolism in fish skeletal muscle cells

AMPK, a master metabolic switch, mediates the observed increase of glucose uptake in locomotory muscle of mammals during exercise. AMPK is activated by changes in the intracellular AMP:ATP ratio when ATP consumption is stimulated by contractile activity but also by AICAR and metformin, compounds that increase glucose transport in mammalian muscle cells. However, the possible role of AMPK in the regulation of glucose metabolism in skeletal muscle has not been investigated in other vertebrates, including fish. In this study, we investigated the effects of AMPK activators on glucose uptake, AMPK activity, cell surface levels of trout GLUT4 and expression of GLUT1 and GLUT4 as well as the expression of enzymes regulating glucose disposal and PGC1α in trout myotubes derived from a primary muscle cell culture. We show that AICAR and metformin significantly stimulated glucose uptake (1.6 and 1.3 fold, respectively) and that Compound C completely abrogated the stimulatory effects of the AMPK activators on glucose uptake. The combination of insulin and AMPK activators did not result in additive nor synergistic effects on glucose uptake. Moreover, exposure of trout myotubes to AICAR and metformin resulted in an increase in AMPK activity (3.8 and 3 fold, respectively). We also provide evidence suggesting that stimulation of glucose uptake by AMPK activators in trout myotubes may take place, at least in part, by increasing the cell surface and mRNA levels of trout GLUT4. Finally, AICAR increased the mRNA levels of genes involved in glucose disposal (hexokinase, 6-phosphofructokinase, pyruvate kinase and citrate synthase) and mitochondrial biogenesis (PGC-1α) and did not affect glycogen content or glycogen synthase mRNA levels in trout myotubes. Therefore, we provide evidence, for the first time in non-mammalian vertebrates, suggesting a potentially important role of AMPK in stimulating glucose uptake and utilization in the skeletal muscle of fish

Conseqüències fisiològiques d'una activació del sistema immunitari sobre la reproducció i el creixement en peixos d'interès en aqüicultura

En peixos teleostis, una activació del sistema immunitari comporta la producció de factors immunitaris que ajuden a combatre una infecció i estableixen una comunicació entre la resposta immunitària innata i l'adaptativa. A part d'aquesta funció estrictament immunitària, els factors immunitaris poden afectar el funcionament d'altres cèl·lules i teixits no immunitaris. Dos processos particularment importants, tant per l'estat biològic d'una població de peixos, com per aspectes més relacionats amb la productivitat d'espècies en cultiu, són la reproducció i el creixement. En aquest treball es descriuen estudis encaminats a investigar els efectes d'una activació del sistema immunitari, i dels factors produïts, sobre la reproducció i el creixement en peixos teleostis.In teleost fish, an activation of the immune system entails the production of immune factors that are key to fighting an infeccion and establish a bridge between the innate and Daquesthe adaptive immune responses. In addition to this strictly immune function, immune factors can also affect the function of other non-immune cells and tissues. Reproduction and growth are two processes that are particularly important for the biological condition of a population of fish as well as for aspects more related to productivity of cultured species. In this paper, we describe studies designed to investigate the effects of an activation of the immune system, as well as of the factors produced, on reproduction and growth in teleost fish

Immunodetection of AMPK subunits in trout myotubes.

<p>Western blots were performed with lysates from trout myotubes and from C2C12 myotubes, used as a positive control, subjected to SDS-PAGE (12%) and blotted onto PVDF membranes, using commercial antibodies (at 1∶1000) against the α₁, β₂ and γ₁ subunits of human AMPK. The molecular weight of the protein markers is expressed in kDa.</p

Conseqüències fisiológiques d'una activació del sistema immunitari sobre la reproducción i el creixement en peixos d'interés en aqüicultura

En peixos teleostis, una activació del sistema immunitari comporta la producció de factors immunitaris que ajuden a combatre una infecció i estableixen una comunicació entre la resposta immunitària innata i l'adaptativa. A part d'aquesta funció estrictament immunitària, els factors immunitaris poden afectar el funcionament d'altres cèl·lules i teixits no immunitaris. Dos processos particularment importants, tant per l'estat biològic d'una població de peixos, com per aspectes més relacionats amb la productivitat d'espècies en cultiu, són la reproducció i el creixement. En aquest treball es descriuen estudis encaminats a investigar els efectes d'una activació del sistema immunitari, i dels factors produïts, sobre la reproducció i el creixement en peixos teleostis.In teleost fish, an activation of the immune system entails the production of immune factors that are key to fighting an infeccion and establish a bridge between the innate and the adaptive immune responses. In addition to this strictly immune function, immune factors can also affect the function of other non-immune cells and tissues. Reproduction and growth are two processes that are particularly important for the biological condition of a population of fish as well as for aspects more related to productivity of cultured species. In this paper, we describe studies designed to investigate the effects of an activation of the immune system, as well as of the factors produced, on reproduction and growth in teleost fish

In Vivo Effects of Lipopolysaccharide on Peroxisome Proliferator-Activated Receptor Expression in Juvenile Gilthead Seabream (Sparus Aurata)

Fish are constantly exposed to microorganisms in the aquatic environment, many of which are bacterial pathogens. Bacterial pathogens activate the innate immune response in fish involving the production of pro-inflammatory molecules that, in addition to their immune-related role, can affect non-immune tissues. In the present study, we aimed at investigating how inflammatory responses can affect metabolic homeostasis in the gilthead seabream (Sparus aurata), a teleost of considerable economic importance in Southern European countries. Specifically, we mimicked a bacterial infection by in vivo administration of lipopolysaccharide (LPS, 6 mg/kg body weight) and measured metabolic parameters in the blood and, importantly, the mRNA expression levels of the three isotypes of peroxisome proliferator activated receptors (PPARα, β, and γ) in metabolically-relevant tissues in seabream. PPARs are nuclear receptors that are important for lipid and carbohydrate metabolism in mammals and that act as biological sensors of altered lipid metabolism. We show here that LPS-induced inflammatory responses result in the modulation of triglyceride plasma levels that are accompanied most notably by a decrease in the hepatic mRNA expression levels of PPARα, β, and γ and by the up-regulation of PPARγ expression only in adipose tissue and the anterior intestine. In addition, LPS-induced inflammation results in an increase in the hepatic mRNA expression and protein activity levels of members of the mitogen-activated protein kinase (MAPK) family, known in mammals to regulate the transcription and activity of PPARs. Our results provide evidence for the involvement of PPARs in the metabolic response to inflammatory stimuli in seabream and offer insights into the molecular mechanisms underlying the redirection of metabolic activities under inflammatory conditions in vertebrates