RESUMEN
The present study explored effects of L-glutamate (Glu) levels on growth, digestive and absorptive capability, and intestinal physical barrier functions of Jian carp (Cyprinus carpio). A total of 600 Jian carp (126.40 ± 0.21 g) were randomly distributed into 5 groups with 3 replicates each, fed diets containing graded levels of Glu (53.4 [control], 57.2, 60.6, 68.4, and 83.4 g/kg) for 63 d. Results showed compared with control diet, feed intake and percent weight gain (PWG) in fish fed 83.4 g of Glu/kg diet were increased and feed conversion ratio in fish fed 68.4 g of Glu/kg diet was decreased (P < 0.05). Similarly, body crude protein and lipid contents in fish fed 68.4 g of Glu/kg diet were higher (P < 0.05). The activities of trypsin and chymotrypsin in the hepatopancreas and intestine, and amylase, alkaline phosphatase (AKP), Na+, K+-ATPase (NKA), and creatine kinase (CK) in intestine were higher in fish fed 68.4 g of Glu/kg diet (P < 0.05). Dietary Glu (57.2 to 83.4 g/kg diet) decreased malondialdehyde (MDA) and protein carbonyl (PCO) contents in the intestine (P < 0.05). The activities of catalase (CAT), glutathione peroxidase (GPx), and glutathione S-transferase (GST) in the hepatopancreas and intestine were higher in fish fed 60.6 and 68.4 g of Glu/kg diets (P < 0.05). Intestinal the glutathione reductase (GR) activity and glutathione (GSH) content in fish fed 60.6, 68.4, and 83.4 g of Glu/kg diet were increased (P < 0.05). The GPx1a, GST, and nuclear factor erythroid 2-related factor 2 (Nrf2) mRNA expressions in the intestine were up-regulated in fish fed 60.6 and 68.4 g of Glu/kg diet (P < 0.05). The zonula occludens protein-1 (ZO-1), occludin1, and claudin3 mRNA expressions were also up-regulated in fish fed 83.4 g of Glu/kg diet (P < 0.05). Fish fed 68.4 g of Glu/kg diet had higher levels of claudin 2, claudin7, and protein kinase C (PKC) mRNA (P < 0.05). These results indicated that Glu improved fish growth, digestive and absorptive ability, and intestinal physical barrier functions. Based on the quadratic regression analysis of PWG, and MDA of the hepatopancreas and intestine, the optimal dietary Glu levels were estimated to be 81.97, 71.06, and 71.36 g/kg diet, respectively.
RESUMEN
Fatty liver is an increasingly serious disease of fish in aquaculture. However, the mechanisms responsible for the occurrence of fatty liver remain unclear, and no effective methods for the prevention and treatment of this disease have yet been found. In the present study, we aimed to develop an in vitro model of hepatocyte injury using oleic acid as hepatotoxicant and evaluate the protective effects of Rhizoma Alismatis extract (RAE) in Jian carp using this model. Primary hepatocytes from Jian carp were isolated and purified and cultured in vitro. The result indicated that 0.4 mmol L-1 oleic acid and 48 h could be the optimal conditions to induce hepatocyte injury model in cultured hepatocytes. Hepatocytes were exposed to oleic acid, followed by the addition of RAE at 0, 1, 5, 10, 20, or 50 µg mL-1. The hepatocytes and supernatant were then analyzed. RAE suppressed oleic acid-induced elevations in aspartate aminotransferase, alanine aminotransferase, triglycerides, total cholesterol, lactate dehydrogenase, alkaline phosphatase, cholinesterase, malondialdehyde, γ-glutamyl transferase, cytochrome P450 1A, cytochrome P450 2E1, liver-type fatty acid binding protein, free fatty acid, fatty acid synthetase, and tumor necrosis factor-α (P < 0.01 or P < 0.05); reduced protein levels of cytochrome P450 1A, nuclear factor (NF)-κB p65, and NF-κB c-Rel; and inhibited cytochrome P4503A, NF-κB c-Rel, nuclear factor erythroid-related factor 2, peroxisome proliferator-activated receptor-α, and cytochrome P4501A mRNA levels. In conclusion, RAE exhibited a protective effect against hepatocyte injury in Jian carp. Further in vivo studies are needed to provide more evidence for the use of RAE as a hepatoprotective agent for the treatment of hepatocyte injury.
Asunto(s)
Alisma , Hepatocitos/efectos de los fármacos , Extractos Vegetales/farmacología , Animales , Carpas/genética , Carpas/metabolismo , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Sistema Enzimático del Citocromo P-450/metabolismo , Hígado Graso/metabolismo , Hígado Graso/veterinaria , Enfermedades de los Peces/metabolismo , Expresión Génica/efectos de los fármacos , Hepatocitos/metabolismo , Hepatocitos/patología , L-Lactato Deshidrogenasa/metabolismo , Metabolismo de los Lípidos/efectos de los fármacos , FN-kappa B/metabolismo , Ácido Oléico , Rizoma , Transaminasas/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , gamma-Glutamiltransferasa/metabolismoRESUMEN
This study aimed to investigate the effects of choline deficiency on intestinal inflammation of fish after Aeromonas hydrophila infection and the potential molecular mechanisms. Juvenile Jian carp (Cyprinus carpio var. Jian) were fed two diets containing choline at 165 (deficient group) and 607 mg/kg diet respectively for 65 days. Choline deficiency decreased intestinal lysozyme activity, C3 and IgM contents, increased acid phosphatase activity, downregulated mRNA levels of antimicrobial peptides [liver-expressed antimicrobial peptide (LEAP) 2A, LEAP-2B, hepcidin and defensin], cytokines [interleukin (IL) 6a, tumor necrosis factor α (TNF-α), interferon γ2b (IFN-γ2b), IL-6b and transforming growth factor ß2 (TGF-ß2) only in proximal intestine, IL-10 in mid and distal intestine], immune-related signaling molecules [Toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), nuclear factor kappa B (NF-κB), inhibitor of NF-κB (IκB), Janus kinase 3 (JAK3), and signal transducers and activators of transcription 5 (STAT5)], tight junction proteins (claudin 3b, claudin 3c, claudin 11 and occludin), and mitogen-activated protein kinases p38 (p38MAPK) in proximal and distal intestine of juvenile Jian carp after A. hydrophila challenge. In contrast, choline deficiency upregulated mRNA levels of antimicrobial peptides (LEAP-2A, LEAP-2B, hepcidin and defensin), cytokines (IL-6b, IFN-γ2b and TGF-ß2), immune-related signaling molecules (TLR4, MyD88, NF-κB, IκB, JAK3, STAT4 in three intestinal segments, and STAT6), claudin 11, and p38MAPK in mid intestine of fish. This study provides new finding that choline deficiency-induced immune responses against A. hydrophila infection were varied among three intestinal segments in fish.
Asunto(s)
Carpas , Deficiencia de Colina/veterinaria , Colina/farmacología , Enteritis/veterinaria , Enfermedades de los Peces/inmunología , Infecciones por Bacterias Gramnegativas/veterinaria , Inmunidad Innata/efectos de los fármacos , Aeromonas hydrophila , Alimentación Animal/análisis , Animales , Colina/administración & dosificación , Deficiencia de Colina/complicaciones , Deficiencia de Colina/inmunología , Citocinas/genética , Citocinas/metabolismo , Dieta/veterinaria , Suplementos Dietéticos/análisis , Relación Dosis-Respuesta a Droga , Enteritis/complicaciones , Enteritis/tratamiento farmacológico , Enteritis/inmunología , Enfermedades de los Peces/tratamiento farmacológico , Enfermedades de los Peces/microbiología , Proteínas de Peces/genética , Proteínas de Peces/metabolismo , Infecciones por Bacterias Gramnegativas/complicaciones , Infecciones por Bacterias Gramnegativas/inmunología , Intestinos/efectos de los fármacos , Intestinos/inmunología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Distribución Aleatoria , Proteínas de Uniones Estrechas/genética , Proteínas de Uniones Estrechas/metabolismoRESUMEN
This study investigated the effect of dietary arginine on the immune response, antioxidant status and tight junction mRNA expression in the intestine of juvenile Jian carp (Cyprinus carpio var. Jian). A total of 1200 juvenile Jian carp with an average initial weight of 6.33 ± 0.03 g were fed graded levels of arginine (9.8-24.5 g kg(-1) diet) for nine weeks. The study showed that arginine deficiency up-regulated interleukin 1, interleukin 8 and transforming growth factor-ß and down-regulated tumour necrosis factor α gene expression (P < 0.05). Additionally, arginine deficiency increased malondialdehyde (MDA), protein carbonyl (PC) and glutathione contents and decreased the activities of copper/zinc superoxide dismutase (SOD1), glutathione peroxidase (GPx), catalase (CAT) and glutathione reductase (GR) and glutathione-S-transferase (GST) (P < 0.05). Meanwhile, arginine deficiency significantly increased claudin 7, occludin, protein kinase C, NF-E2-related factor 2 and Kelch-like-ECH- associated protein 1 mRNA expression and decreased SOD1, CAT and GR mRNA expression (P < 0.05). All of these results indicated that arginine deficiency impaired intestinal immune function via the regulation of mRNA expression of cytokines, tight junction proteins, antioxidant enzymes, Nrf2/Keap1 and PKC in fish intestine.
Asunto(s)
Antioxidantes/metabolismo , Arginina/administración & dosificación , Carpas/inmunología , Citocinas/metabolismo , Proteínas de Peces/genética , Regulación de la Expresión Génica , Proteínas de Uniones Estrechas/genética , Alimentación Animal/análisis , Animales , Carpas/genética , Carpas/metabolismo , Dieta/veterinaria , Suplementos Dietéticos/análisis , Proteínas de Peces/metabolismo , Intestinos/inmunología , Transducción de Señal , Proteínas de Uniones Estrechas/metabolismoRESUMEN
The aim of this study was to establish a model for the study of liver injury induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in Jian carp using precision-cut liver slices (PCLS). PCLS were treated with TCDD at concentrations of 0, 0.05, 0.1, 0.3, and 0.6 µg/L for 6 h, followed by collection of the culture supernatant and PCLS for analysis. Several biochemical indices were analyzed, including glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT), lactate dehydrogenase (LDH), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA). Expression of mRNA was also estimated for cytochrome P4501A (CYP1A), aryl hydrocarbon receptor2 (AhR2), and aryl hydrocarbon receptor nuclear translocator2 (ARNT2). Results showed that some significant effects (p < 0.05) in MDA, GSH-Px and PCLS viability were observed at a TCDD concentration as low as 0.05 µg/L, and the observed effects increased with exposure concentration. Following exposure to TCDD for 6 h at a concentration of 0.3 µg/L, significant increases (p < 0.01) in the content of GPT, GOT, MDA, and LDH were observed, while SOD activity, GSH-Px activity, and PCLS viability were decreased (p < 0.01 or p < 0.05). Exposure to 0.3 µg/L TCDD also resulted in increased expression of mRNA for CYP1A, AhR2, and ARNT2. Overall, these results provide evidence of TCDD-induced liver injury and oxidative stress in Jian carp. These results also support the use of PCLS as an in vitro model for the evaluation of hepatotoxicity in Jian carp.
Asunto(s)
Carpas/metabolismo , Técnicas In Vitro/métodos , Hígado/efectos de los fármacos , Estrés Oxidativo/efectos de los fármacos , Dibenzodioxinas Policloradas/toxicidad , Animales , Glutatión Peroxidasa/metabolismo , Hígado/metabolismo , Malondialdehído/metabolismo , Oxidación-Reducción , ARN Mensajero/metabolismo , Receptores de Hidrocarburo de Aril/metabolismo , Superóxido Dismutasa/metabolismoRESUMEN
The present study investigated the effect of body weight on body composition, digestive and absorptive capacity, transaminase activities in hepatopancreas and muscle, and plasma ammonia concentration of Jian carp (Cyprinus carpio var. Jian). A total of 750 Jian carps (18.0 ± 0.2 g) were randomly distributed into five groups with three replicates and fed the same diet for 56 days. Tissue and plasma samples were collected on days 14, 28, 42, and 56. The results were used to develop a mathematical model for specific growth rate, body moisture and fat content, aspartate transaminase activity and alanine aminotransferase activity in hepatopancreas and muscle, plasma ammonia concentration, and trypsin, chymotrypsin, lipase, and amylase activities in hepatopancreas and intestine, activities of creatine kinase, Na+/K+-ATPase, alkaline phosphatase, and γ-glutamyl transpeptidase in intestine in Jian carp. There were linear relationships between natural logarithms of above indexes and body weight. The body moisture and fat content, digestive and absorptive enzymes activities, and transaminase activities showed negative allometry against body weight of Jian carp which were partial reasons to explain fish growth rate decreasing.
RESUMEN
The brain is the center of the nervous system in all vertebrates, and homeostasis of the brain is crucial for fish survival. Copper (Cu) is essential for normal cellular processes in most eukaryotic organisms but is toxic in excess. Although Cu is indicated as a potent neurotoxicant, information regarding its threat to fish brain and underlying mechanisms is still scarce. In accordance, the objective of this study was to assess the effects and the potential mechanism of Cu toxicity by evaluating brain oxidative status, the enzymatic and mRNA levels of antioxidant genes, as well as the Nrf2/ARE signaling in the brain of fish after Cu exposure. The protective effects of myo-inositol (MI) against subsequent Cu exposure were also investigated. The results indicate that induction of oxidative stress by Cu is shown by increases in brain ROS production, lipid peroxidation and protein oxidation, which are accompanied by depletions of antioxidants, including total superoxide dismutase (T-SOD), CuZnSOD, glutathione-S-transferase (GST) and glutathione reductase (GR) activities and glutathione (GSH) content. Cu exposure increased the catalase (CAT) and glutathione peroxidase (GPx) activities. Further molecular results showed that Cu exposure up-regulated CuZnSOD, GPx1a and GR mRNA levels, suggesting an adaptive mechanism against stress. Moreover, Cu exposure increased fish brain Nrf2 nuclear accumulation and increased its ability of binding to ARE (CuZnSOD), which supported the increased CuZnSOD mRNA levels. In addition, Cu exposure caused increases of the expression of the Nrf2, Maf G1 (rather than Maf G2 gene) and PKCd genes, suggesting that de novo synthesis of those factors is required for the protracted induction of such antioxidant genes. However, the modulation of Keap1a (rather than Keap1b) of fish brain under Cu exposure might be used to turn off of the signaling cascade and avoid harmful effects. Interestingly, pre-treatment of fish with MI prevented the fish brain from Cu-induced oxidative damages mainly by increasing the GSH content and CuZnSOD and GST activities. Summarily, this study indicates that although Cu stimulates adaptive increases in the expression of some antioxidant enzyme genes through Nrf2/ARE signaling, it also induces oxidation and the depletion of most of antioxidant enzyme activities and GSH content due to the increase of ROS production, and MI protects the fish brain against Cu toxicity.