Time filter

Source Type

Wu H.,Sichuan Agricultural University | Wu H.,Chengdu Agricultural College | Lin F.,Sichuan Agricultural University | Chen H.,Sichuan Agricultural University | And 8 more authors.
Fish Physiology and Biochemistry | Year: 2015

Spexin (SPX) is a novel peptide which was known for its role in physiological homeostasis. A recent study has confirmed that SPX plays an important role in the feeding regulation. However, the reports about SPX are very limited. In the present study, we characterized the structure, distribution and mRNA expression responses to feeding status of SPX in Ya-fish (Schizothorax prenanti). The full-length cDNA of Ya-fish SPX was 1330 base pairs (bp), which encoded 106 amino acid residues. These residues contained a 31-amino acid signal peptide region and a 14-amino acid mature peptide. The sequence alignment demonstrated that the Ya-fish SPX showed high conservation with other species. Our data revealed that SPX was widely expressed in all test tissues. The highest expression of SPX mRNA was observed in Ya-fish forebrain. Compared with the Ya-fish SPX mRNA expression in the forebrain between the preprandial and postprandial groups, the fed group was prominently increased than unfed groups after a meal, while the unfed group at 1 and 3 h substantially decreased than preprandial groups (P < 0.01). In addition, SPX mRNA expression in forebrain was significantly decreased (P < 0.01) during fasting for a week and sharply increased (P < 0.01) after refeeding on the 7th day, and then return to normal level on the 9th day. These results point toward that SPX mRNA expression is regulated by metabolic status or feeding conditions in Ya-fish. © 2015 Springer Science+Business Media Dordrecht

Du J.,Sichuan Agricultural University | Cheng X.,Sichuan Agricultural University | Shen L.,Sichuan Agricultural University | Tan Z.,Sichuan Agricultural University | And 9 more authors.
Biochemical and Biophysical Research Communications | Year: 2016

MicroRNAs (miRNAs, miR) play important roles in adipocyte development. Recent studies showed that the expression of several miRNAs is closely related with promoter methylation. However, it is not known whether miRNA mediates adipocytes differentiation by means of DNA methylation. Here, we showed that miR-145a-5p was poorly expressed in adipose tissue from mice fed a high fat diet (HFD). Overexpression or inhibition of miR-145a-5p was unfavorable or beneficial, respectively, for adipogenesis, and these effects were achieved by regulating adipocyte-specific genes involved in lipogenic transcription, fatty acid synthesis, and fatty acid transportation. Particularly, we first suggested that miR-145a-5p mimics or inhibitors promoted or repressed adipocytes proliferation by regulating p53 and p21, which act as cell cycle regulating factors. Surprisingly, the miR-145a-5p-repressed adipocyte differentiation was enhanced or rescued when cells treated with 5-Aza-dC were transfected with miR-145a-5p mimics or inhibitors, respectively. These data indicated that, as a new mean to positively regulate adipocyte proliferation, the process of miR-145a-5p-inhibited adipogenesis may be regulated by DNA methylation. © 2016 Elsevier Inc. All rights reserved.

Jiang W.-D.,Sichuan Agricultural University | Hu K.,Sichuan Agricultural University | Hu K.,Chengdu Agricultural College | Zhang J.-X.,Sichuan Agricultural University | And 10 more authors.
British Journal of Nutrition | Year: 2015

This study investigated the effects of glycinin on the growth, intestinal oxidative status, tight junction components, cytokines and apoptosis signalling factors of fish. The results showed that an 80 g/kg diet of glycinin exposure for 42 d caused poor growth performance and depressed intestinal growth and function of juvenile Jian carp (Cyprinus carpio var. Jian). Meanwhile, dietary glycinin exposure induced increases in lipid peroxidation and protein oxidation; it caused reductions in superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) activities; and it increased MnSOD, CuZnSOD, GPx1b and GPx4a mRNA levels, suggesting an adaptive mechanism against stress in the intestines of fish. However, dietary glycinin exposure decreased both the activity and mRNA levels of nine isoforms of glutathione-S-transferase (GST) (α, μ, π, ρ, θ, κ, mGST1, mGST2 and mGST3), indicating toxicity to this enzyme activity and corresponding isoform gene expressions. In addition, glycinin exposure caused partial disruption of intestinal cell-cell tight junction components, disturbances of cytokines and induced apoptosis signalling in the distal intestines>mid intestines>proximal intestines of fish. Glycinin exposure also disturbed the mRNA levels of intestinal-related signalling factors Nrf2, Keap1a, Keap1b, eleven isoforms of protein kinase C and target of rapamycin/4E-BP. Interestingly, glutamine was observed to partially block those negative influences. In conclusion, this study indicates that dietary glycinin exposure causes intestinal oxidative damage and disruption of intestinal physical barriers and functions and reduces fish growth, but glutamine can reverse those negative effects in fish. This study provides some information on the mechanism of glycinin-induced negative effects. Copyright © The Authors 2015.

Jiang W.-D.,Sichuan Agricultural University | Hu K.,Sichuan Agricultural University | Hu K.,Chengdu Agricultural College | Liu Y.,Sichuan Agricultural University | And 6 more authors.
Fish and Shellfish Immunology | Year: 2016

This study was conducted to investigate the effects of the dietary vitamin myo-inositol (MI), on the immunity and structural integrity of the head kidney and spleen following infection of fish with the major freshwater pathogen bacterial Aeromonas hydrophila. The results demonstrated for the first time that MI deficiency depressed the lysozyme and acid phosphatase (ACP) activities and the complement 3 (C3) and C4 contents in the head kidney and spleen compared with the optimal MI levels, indicating that MI deficiency decreased the immunity of these important fish immune organs. The depression in immunity due to MI deficiency was partially related to oxidative damage [indicated by increases in the malondialdehyde (MDA) and protein carbonyl (PC) contents] that was in turn partially due to the decreased glutathione (GSH) content and the disturbances in antioxidant enzyme activities [total superoxide dismutase (T-SOD), CuZnSOD, MnSOD, catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR)]. MI deficiency inhibited the antioxidant-related gene transcription [CuZnSOD, MnSOD, CAT, GPx1a, GR and NF-E2-related factor 2 (Nrf2)] in the head kidney and spleen following infection of the fish with A. hydrophila. The oxidative damage due to MI deficiency also resulted in the inhibition of proliferation-associated signalling (cyclin D1, cyclin A, cyclin E and E2F4). Thus, MI deficiency partially inhibited damage repair. Excessive MI exhibited negative effects that were similar to MI deficiency, whereas the optimal MI content reversed those indicators. These observations indicated that an MI deficiency or excess could cause depression of the immune system that might be partially related to oxidative damage, antioxidant disturbances, and the inhibition of the proliferation-associated signalling in the head kidney and spleen following infection of fish with A. hydrophila. Finally, the optimal MI levels were 660.7 (based on ACP) and 736.8 mg kg-1 diet (based on MDA) in the head kidney and 770.5 (based on ACP) and 766.9 mg kg-1 diet (based on MDA) in the spleen of juvenile Jian carp. © 2015 Elsevier Ltd.

Huang X.,Sichuan Agricultural University | Huang X.,Chengdu Agricultural College | Chen L.,Sichuan Agricultural University | Yang Y.,China Institute of Technology | And 5 more authors.
Parasites and Vectors | Year: 2015

Background: The larval stage of Taenia multiceps, also known as coenurus, is the causative agent of coenurosis, which results in severe health problems in sheep, goats, cattle and other animals that negatively impact on animal husbandry. There is no reliable method to identify coenurus infected goats in the early period of infection. Methods: We identified a full-length cDNA that encodes acidic ribosomal protein P2 from the transcriptome of T. multiceps (TmP2). Following cloning, sequencing and structural analyses were performed using bioinformatics tools. Recombinant TmP2 (rTmP2) was prokaryotically expressed and then used to test immunoreactivity and immunogenicity in immunoblotting assays. The native proteins in adult stage and coenurus were located via immunofluorescence assays, while the potential of rTmP2 for indirect ELISA-based serodiagnostics was assessed using native goat sera. In addition, 20 goats were randomly divided into a drug treatment group and a control group. Each goat was orally given mature, viable T. multiceps eggs. The drug treatment group was given 10 % praziquantel by intramuscular injection 45 days post-infection (p.i), and all goats were screened for anti-TmP2 antibodies with the indirect ELISA method established here, once a week for 17 weeks p.i. Results: The open reading frame (366 bp) of the target gene encodes a 12.62 kDa protein, which showed high homology to that from Taenia solium (93 % identity) and lacked a signal peptide. Immunofluorescence staining showed that TmP2 was highly localized to the parenchymatous zone of both the adult parasite and the coenurus; besides, it was widely distributed in cystic wall of coenurus. Building on good immunogenic properties, rTmP2-based ELISA exhibited a sensitivity of 95.0 % (19/20) and a specificity of 96.3 % (26/27) in detecting anti-P2 antibodies in the sera of naturally infected goats and sheep. In goats experimentally infected with T. multiceps, anti-TmP2 antibody was detectable in the control group from 3 to 10 weeks and 15 to 17 weeks p.i. In the drug-treated group, the anti-TmP2 antibody dropped below the cut-off value about 2 weeks after treatment with praziquantel and remained below this critical value until the end of the experiment. Conclusion: The indirect ELISA method developed in this study has the potential for detection of T. multiceps infections in hosts. © 2015 Huang et al.

Discover hidden collaborations