Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Int J Biol Macromol ; 188: 460-472, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34391784

RESUMO

This study aimed to characterize the full-length cDNA of thioredoxin-interacting protein (TXNIP) from Megalobrama amblycephala, and investigate its roles in high glucose (HC)-induced inflammatory response. The cDNA obtained covered 2706-bp with an open reading frame of 1203-bp encoding 400 amino acids, compared to Cyprinus carpio, it showed 89.96% homology. The highest expression of txnip was observed in head kidney followed by spleen and liver. After a 12-week feeding trial, high-carbohydrate diet remarkably increased txnip expression in liver and white muscle. Glucose administration resulted in a remarkably increased liver txnip expression, which peaked at 1 h. Thereafter, the expression decreased remarkably to the basal value at 12 h. However, insulin injection resulted in a significant decrease in txnip expression with minimum values attained at 2 h. Subsequently, it gradually increased to the normal values. Moreover, in the in-vitro study, over-expression of txnip along with remarkably increased il-1ß and il-6 expression in hepatocytes, and its knockdown led to remarkably reduced il-1ß expression. Furthermore, metformin treatment remarkably increased the cell viability and trx expression of hepatocytes under high glucose, while the opposite was true for ROS levels, LDH activity, the ALT/AST ratio, Txnip protein content and the transcriptions of txnip, tnfα and il-1ß.

2.
Br J Nutr ; : 1-14, 2021 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-33749571

RESUMO

A12-week experiment was conducted to evaluate the influences of thiamine ongrowth performance, and intestinal mitochondrial biogenesis and function of Megalobramaamblycephala fed a high-carbohydrate (HC) diet. Fish (24·73 (sem 0·45) g) were randomly assigned to one of four diets: two carbohydrate (CHO) levels (30 and 45 %) and two thiamine levels (0 and 1·5 mg/kg). HC diets significantly decreased DGC, GRMBW, FIMBW, intestinal activities of amylase, lipase, Na+, K+-ATPase, CK, complexes I, III and IV, intestinal ML, number of mitochondrial per field, ΔΨm, the P-AMPK: T-AMPK ratio, PGC-1ß protein expression as well as the transcriptions of AMPKα1, AMPKα2, PGC-1ß, mitochondrial transcription factor A, Opa-1, ND-1 and COX-1 and 2, while the opposite was true for ATP, AMP and reactive oxygen species, and the transcriptions of dynamin-related protein-1, fission-1 and mitochondrial fission factor. Dietarythiamine concentrations significantly increased DGC, GRMBW, intestinal activities of amylase, Na+, K+-ATPase, CK, complexes I and IV, intestinal ML, number of mitochondrial per field, ΔΨm, the P-AMPK:T-AMPK ratio, PGC-1ß protein expression as well as the transcriptions of AMPKα1, AMPKα2, PGC-1ß, Opa-1, ND-1, COX-1 and 2, SGLT-1 and GLUT-2. Furthermore, a significant interaction between dietary CHO and thiamine was observed in DGC, GRMBW, intestinal activities of amylase, CK, complexes I and IV, ΔΨm, the AMP:ATP ratio, the P-AMPK:T-AMPK ratio, PGC-1ß protein expression as well as the transcriptions of AMPKα1, AMPKα2, PGC-1ß, Opa-1, COX-1 and 2, SGLT-1 and GLUT-2. Overall, thiamine supplementation improved growth performance, and intestinal mitochondrial biogenesis and function of M. amblycephala fed HC diets.

3.
Artigo em Inglês | MEDLINE | ID: mdl-31733535

RESUMO

Promoting highly unsaturated fatty acid (HUFA) uptake and deposition can improve nutritional value of farmed fish and reduce dietary fish oil addition. Previously, we found that the golden pompano Trachinotus ovatus liver HUFA content increased with the increasing of dietary HUFA. Therefore, we examined the common genes and pathways responsible for HUFA uptake and deposition in T. ovatus liver using transcriptome sequencing technology after feeding with either 1.0% or 2.1% HUFA for 8 weeks. Results showed that a total of 140 and 147 genes were significantly upregulated and downregulated, respectively. Five bile acid synthesis-related genes (CYP7A1, CYP8B1, AKR1D1, SCP2 and ACOT8), which are related to dietary fat emulsification were downregulated in 2.1% HUFA group, implying that the cholate synthesized through the classical pathway might be the main bile acid form in fat emulsification. Moreover, fatty acid transport protein (FATP)-6, fatty acid binding protein (FABP)-1, -4, and -6 increased with HUFA deposition, especially FATP6 and FABP4, suggesting that the two genes may be important mediators involved in HUFA uptake and deposition. KEGG analysis showed that most of the differential genes described above were involved in peroxisome proliferator activator receptor (PPAR) signaling pathway, and PPARγ increased with HUFA deposition, indicating that PPARγ might be a key regulator of HUFA uptake and deposition by regulating the genes involved in fatty acid emulsification and transport. This study focused on the liver, which is the center of intermediary metabolism, providing a comprehensive understanding of the molecular regulation of HUFA uptake and deposition in T. ovatus, which should be further investigated to develop potential measures to improve HUFA content.


Assuntos
Ácidos Graxos Insaturados/metabolismo , Peixes/genética , Transcriptoma , Animais , Ácidos Graxos Insaturados/genética , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Peixes/metabolismo , Perfilação da Expressão Gênica , Fígado/metabolismo , Transdução de Sinais
4.
Genomics ; 112(3): 2213-2222, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31881264

RESUMO

As one important member of the two-pore-domain potassium channel (K2P) family, potassium channel subfamily K member 3 (KCNK3) has been reported for thermogenesis regulation, energy homeostasis, membrane potential conduction, and pulmonary hypertension in mammals. However, its roles in fishes are far less examined and published. In the present study, we identified two kcnk3 genes (kcnk3a and kcnk3b) in an euryhaline fish, Nile tilapia (Oreochromis niloticus), by molecular cloning, genomic survey and laboratory experiments to investigate their potential roles for osmoregulation. We obtained full-length coding sequences of the kcnk3a and kcnk3b genes (1209 and 1173 bp), which encode 402 and 390 amino acids, respectively. Subsequent multiple sequence alignments, putative 3D-structure model prediction, genomic survey and phylogenetic analysis confirmed that two kcnk3 paralogs are widely presented in fish genomes. Interestingly, a DNA fragment inversion of a kcnk3a cluster was found in Cypriniforme in comparison with other fishes. Quantitative real-time PCRs demonstrated that both the tilapia kcnk3 genes were detected in all the examined tissues with a similar distribution pattern, and the highest transcriptions were observed in the heart. Meanwhile, both kcnk3 genes in the gill were proved to have a similar transcriptional change pattern in response to various salinity of seawater, implying that they might be involved in osmoregulation. Furthermore, three predicted transcription factors (arid3a, arid3b, and arid5a) of both kcnk3 genes also showed a similar pattern as their target genes in response to the various salinity, suggesting their potential positive regulatory roles. In summary, we for the first time characterized the two kcnk3 genes in Nile tilapia, and demonstrated their potential involvement in osmoregulation for this economically important fish.


Assuntos
Proteínas de Peixes/genética , Proteínas do Tecido Nervoso/genética , Canais de Potássio de Domínios Poros em Tandem/genética , Tilápia/genética , Animais , Clonagem Molecular , Proteínas de Peixes/química , Proteínas de Peixes/classificação , Proteínas de Peixes/metabolismo , Genoma , Modelos Moleculares , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/classificação , Proteínas do Tecido Nervoso/metabolismo , Filogenia , Canais de Potássio de Domínios Poros em Tandem/química , Canais de Potássio de Domínios Poros em Tandem/classificação , Canais de Potássio de Domínios Poros em Tandem/metabolismo , Conformação Proteica , Salinidade , Água do Mar , Alinhamento de Sequência , Análise de Sequência de Proteína , Tilápia/metabolismo , Distribuição Tecidual , Fatores de Transcrição/genética , Transcrição Genética
5.
Gen Comp Endocrinol ; 281: 49-57, 2019 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-31121162

RESUMO

Potassium channel subfamily K member 3 (KCNK3) has been reported to play important roles in membrane potential conduction, pulmonary hypertension and thermogenesis regulation in mammals. However, its roles remain largely unknown and scarce reports were seen in fish. In the present study, we for the first time identified two kcnk3 genes (kcnk3a and kcnk3b) from the carnivorous Northern snakehead (Channa argus) by molecular cloning and a genomic survey. Subsequently, their transcription changes in response to different feeding status were investigated. Full-length coding sequences of the kcnk3a and kcnk3b genes are 1203 and 1176 bp, encoding 400 and 391 amino acids, respectively. Multiple alignments, 3D-structure prediction and phylogenetic analysis further suggested that these kcnk3 genes may be highly conserved in vertebrates. Tissue distribution analysis by real-time PCR demonstrated that both the snakehead kcnk3s were widely transcribed in majority of the examined tissues but with different distribution patterns. In a short-term (24-h) fasting experiment, we observed that brain kcnk3a and kcnk3b genes showed totally opposite transcription patterns. In a long-term (2-week) fasting and refeeding experiment, we also observed differential change patterns for the brain kcnk3 genes. In summary, our findings suggest that the two kcnk3 genes are close while present different transcription responses to fasting and refeeding. They therefore can be potentially selected as novel target genes for improvement of production and quality of this economically important fish.


Assuntos
Jejum/fisiologia , Comportamento Alimentar , Peixes/genética , Canais de Potássio de Domínios Poros em Tandem/genética , Transcrição Genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , DNA Complementar/genética , Genoma , Filogenia , Canais de Potássio de Domínios Poros em Tandem/química , Canais de Potássio de Domínios Poros em Tandem/metabolismo , Sintenia/genética , Distribuição Tecidual , Peixe-Zebra/genética
6.
Mar Biotechnol (NY) ; 21(4): 475-487, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31020472

RESUMO

Post-transcriptional regulatory mechanisms play important roles in the regulation of LC-PUFA biosynthesis. Our previous study revealed that miR-33 could increase the expression of fatty acyl desaturases (fads2) in the rabbitfish Siganus canaliculatus, but the specific mechanism is unknown. Here, we confirmed that miR-33 could target the 3'UTR of insulin-induced gene 1 (insig1), resulting in downregulation of its protein level in the rabbitfish hepatocyte line (SCHL). In vitro overexpression of miR-33 inhibited the mRNA level of insig1 and increased the mRNA levels of Δ6Δ5 fads2 and elovl5, as well as srebp1. In SCHL cells, proteolytic activation of sterol-regulatory-element-binding protein-1 (Srebp1) was blocked by Insig1, with overexpression of insig1 decreasing mature Srebp1 level, while inhibition of insig1 led to the opposite effect. Srebp1 could enhance the promoter activity of Δ6Δ5 fads2 and elovl5, whose expression levels decreased with knockdown of srebp1 in SCHL. Overexpression of miR-33 also resulted in a higher conversion of 18:3n-3 to 18:4n-3 and 20:5n-3 to 22:5n-3, linked to desaturation and elongation via Δ6Δ5 Fads2 and Elovl5, respectively. The results suggested that the mechanism by which miR-33 regulates LC-PUFA biosynthesis in rabbitfish is through enhancing the expression of srebp1 by targeting insig1. The findings here provide more insight to the mechanism of miRNAs involvement in the regulation of LC-PUFA biosynthesis in teleosts.


Assuntos
Ácidos Graxos Dessaturases/genética , Ácidos Graxos Insaturados/biossíntese , Proteínas de Peixes/genética , MicroRNAs/genética , Perciformes/genética , Proteína de Ligação a Elemento Regulador de Esterol 1/genética , Regiões 3' não Traduzidas , Animais , Linhagem Celular , Clonagem Molecular , Ácidos Graxos Dessaturases/metabolismo , Proteínas de Peixes/metabolismo , Expressão Gênica , Regulação da Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Células HEK293 , Hepatócitos/citologia , Hepatócitos/metabolismo , Humanos , Metabolismo dos Lipídeos/genética , MicroRNAs/metabolismo , Perciformes/metabolismo , Regiões Promotoras Genéticas , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transdução de Sinais , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo
7.
Front Immunol ; 8: 611, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28659912

RESUMO

Invertebrates rely heavily on immune-like molecules with highly diversified variability so as to counteract infections. However, the mechanisms and the relationship between this variability and functionalities are not well understood. Here, we showed that the C-terminal domain of hemocyanin (HMC) from shrimp Litopenaeus vannamei contained an evolutionary conserved domain with highly variable genetic sequence, which is structurally homologous to immunoglobulin (Ig). This domain is responsible for recognizing and binding to bacteria or red blood cells, initiating agglutination and hemolysis. Furthermore, when HMC is separated into three fractions using anti-human IgM, IgG, or IgA, the subpopulation, which reacted with anti-human IgM (HMC-M), showed the most significant antimicrobial activity. The high potency of HMC-M is a consequence of glycosylation, as it contains high abundance of α-d-mannose relative to α-d-glucose and N-acetyl-d-galactosamine. Thus, the removal of these glycans abolished the antimicrobial activity of HMC-M. Our results present a comprehensive investigation of the role of HMC in fighting against infections through genetic variability and epigenetic modification.

8.
Comp Biochem Physiol B Biochem Mol Biol ; 151(2): 183-90, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18639644

RESUMO

Delta(6)-Desaturase (linoleoyl-CoA desaturase, EC 1.14.19.3) is the rate-limiting enzyme in the biosynthetic pathway of highly unsaturated fatty acid (HUFA). In this report, a Delta6 desaturase-like cDNA was cloned, and the relation of HUFA biosynthetic activity in liver with ambient salinity as well as dietary fatty acids was investigated in the euryhaline teleost Siganus canaliculatus. After the juveniles were fed four formulated diets (D1-D4) with different essential fatty acid composition (D1 with 23.49% HUFA, D2-D4 were HUFA-free, linoleic and alpha-linolenic acids account for 21.1% and 0.38%, 13.99% and 11.64%, 18.31% and 5.82% of the total fatty acids, respectively) for nine weeks, the growth performance showed no difference among groups in brackish water (10 ppt) or seawater (32 ppt) (P>0.05). Comparing liver fatty acids with fish fed D1, the content of arachidonic acid in fish fed D2 or D4 was significantly higher in 10 ppt (P<0.05), but showed no difference in 32 ppt; the contents of eicosapentaenoic (EPA), docosapentaenoic (DPA) and docosahexaenoic (DHA) acids in 10 ppt, as well as EPA in 32 ppt in fish fed D3 showed no difference, whereas those of DPA and DHA were significantly lower in 32 ppt (P<0.05). These data suggest that S. canaliculatus may convert linoleic and alpha-linolenic acids into HUFA and such a capacity was stronger in low salinity than that in high salinity. Consistent with this, the liver levels of Delta6 desaturase mRNA in fish fed D2-D4 were generally higher than in fish fed D1 in both salinities, and the total expression level in 10 ppt was about 1.56 times of that in 32 ppt, suggesting that transcriptional control of Delta6 desaturase is involved in such a HUFA biosynthesis. To our knowledge, this is the first report showing the relation of HUFA biosynthetic activity with ambient salinity in a euryhaline fish.


Assuntos
Gorduras Insaturadas na Dieta/administração & dosagem , Ácidos Graxos Essenciais/administração & dosagem , Linoleoil-CoA Desaturase/genética , Fígado/metabolismo , Perciformes/genética , Perciformes/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Primers do DNA/genética , Ácidos Graxos/análise , Ácidos Graxos/metabolismo , Ácidos Graxos Insaturados/biossíntese , Expressão Gênica , Linoleoil-CoA Desaturase/metabolismo , Dados de Sequência Molecular , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Salinidade , Água do Mar , Homologia de Sequência de Aminoácidos , Distribuição Tecidual
9.
Zoolog Sci ; 20(2): 211-9, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12655184

RESUMO

Steroidogenic acute regulatory protein (StAR) is a key molecule for steroid production by translocating cholesterol from the outer to inner mitochondrial membrane. Two cDNAs of different length encoding StAR was cloned from the head kidney of the eel (Anguilla japonica). In the 3'-untranslated region (UTR) of the longer cDNA, two putative polyadenylation signals were found. The shorter one differed from the longer one solely by the lack of middle of 3'-UTR including the first polyadenylation signal. Reverse transcription-polymerase chain reaction (RT-PCR) that differentiates the two mRNAs showed that the ratio of the two was highly variable among individuals, and no preferential expression was detected between freshwater and seawater eels. The predicted protein consists of 285 amino acid residues with 64-83% identity to other StARs thus far obtained. RT-PCR analyses revealed that eel StAR mRNA was expressed abundantly in the head kidney and gonad, and faintly in the brain; but no expression was detected in the gill, heart, liver, intestine, kidney and skeletal muscle. Plasma cortisol concentration increased, but StAR mRNA content in the head kidney did not change, 3 and 24 h after transfer of freshwater eels to seawater, indicating that the transcriptional regulation of StAR may not be involved in cortisol production after seawater transfer. However, ACTH elevated both plasma cortisol and StAR mRNA levels in the head kidney 1.5 and 4.5 h after injection. Thus, the steroidogenic effect of ACTH is mediated by increased StAR production as observed in mammals.


Assuntos
Hormônio Adrenocorticotrópico/farmacologia , Anguilla/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Fosfoproteínas/genética , Água do Mar/química , Adaptação Fisiológica , Sequência de Aminoácidos , Anguilla/sangue , Animais , Sequência de Bases , Clonagem Molecular , DNA Complementar/genética , Hidrocortisona/sangue , Dados de Sequência Molecular , Especificidade de Órgãos , Fosfoproteínas/química , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Alinhamento de Sequência , Sódio/análise , Sódio/farmacologia , Fatores de Tempo
10.
Gen Comp Endocrinol ; 130(3): 317-23, 2003 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-12606274

RESUMO

The effects of three eel natriuretic peptides (NPs), i.e., ANP, VNP, and CNP on plasma cortisol levels were investigated in conscious freshwater (FW)- and seawater (SW)-adapted eels with permanent arterial catheter. The experiment was performed between 9:00 and 15:00 of the day, when the natural plasma cortisol level was relatively stable. After a single intra-arterial injection of ANP, VNP, or CNP at 100 pmol/kg, only CNP, but not ANP or VNP, increased plasma cortisol concentration in FW eels. In SW eels, however, only ANP at the same dose increased plasma cortisol concentration. The effect of CNP in FW eels and that of ANP in SW eels were dose-dependent between 10 and 1000 pmol/kg. On the other hand, ANP and VNP were equally effective, but CNP was ineffective, in increasing hematocrit in both FW and SW eels. These results show that the effect of NPs on plasma cortisol level is dependent on the ambient salinity in the eel. Since cortisol plays a pivotal role in environmental adaptation of fishes, the results suggest a possible involvement of ANP and CNP in the adaptation to SW and FW, respectively. Furthermore, this is the first evidence showing that ANP and VNP exert different effects in fish despite they share the same receptor, NPR-A.


Assuntos
Fator Natriurético Atrial/sangue , Enguias/sangue , Hidrocortisona/sangue , Peptídeo Natriurético Tipo C/sangue , Equilíbrio Hidroeletrolítico/fisiologia , Adaptação Fisiológica , Animais , Ritmo Circadiano , Relação Dose-Resposta a Droga , Água Doce , Hematócrito , Técnicas Imunoenzimáticas , Água do Mar/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...