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Sun Q, Zhai W, Wang H, Gao Z, Liu H. A novel lncRNA MSTRG.59348.1 regulates muscle cells proliferation and innate immunity of Megalobrama amblycephala. Int J Biol Macromol 2025:139445. [PMID: 39756731 DOI: 10.1016/j.ijbiomac.2024.139445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2024] [Revised: 12/30/2024] [Accepted: 12/31/2024] [Indexed: 01/07/2025]
Abstract
In mammals, long non-coding RNAs (lncRNAs) play a regulatory role in gene expression, contribute to immune responses, and aid in pathogen elimination, primarily through interactions with RNA-binding proteins (RBPs). However, the role of lncRNAs in fish innate immunity and their interaction with RBPs remains uncertain. To investigate the immunomodulatory role of lncRNAs in Megalobrama amblycephala, we identified the novel lncRNA MSTRG.59348.1 and examined its function in the innate immune response to Aeromonas hydrophila infection. Localization studies in hepatocytes revealed that MSTRG.59348.1 is primarily located in the nucleus, suggesting its potential involvement in gene regulation, possibly through chromatin modification or other nuclear processes. The expression of MSTRG.59348.1 was significantly up-regulated after lipopolysaccharide (LPS) stimulation in liver cells. RNA-seq analysis of muscle cells revealed that genes differentially expressed following MSTRG.59348.1 overexpression were enriched in immune pathways. MSTRG.59348.1 overexpression significantly inhibited the expression of sting and ifn, and significantly up-regulated muscle cell viability and promoted cell proliferation by targeting sting, ifn, nf-κb1, and bcl2. Screening by RNA pull-down and mass spectrometry identified 57 RBPs interacting with MSTRG.59348.1, with functions enriched in immune pathways. Our results suggest that MSTRG.59348.1 plays a crucial regulatory role in fish antibacterial response, marking it as a significant subject for future research in innate immunity.
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Jia X, Liu J, Jiang W, Chang L, Shen X, Jiang G, Li X, Chi C, Liu W, Zhang D. Binding site redundancy is critical for the regulation of fas by miR-30c in blunt snout bream ( Megalobrama amblycephala). Comp Biochem Physiol A Mol Integr Physiol 2025; 299:111763. [PMID: 39395751 DOI: 10.1016/j.cbpa.2024.111763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2024] [Revised: 10/09/2024] [Accepted: 10/09/2024] [Indexed: 10/14/2024]
Abstract
MiR-30c and fatty acid synthase (fas) both play important roles in physiological processes such as lipid synthesis and fat metabolism. Predictive analysis revealed that fas is a target gene of miR-30c with multiple seed sites. Seed sites are useful to predict miRNA targeting relationships; however, detailed analyses of seed sites in fish genomes remain poorly studied. In this study, the regulatory relationship between miR-30c and fas, number and effect of seed regions, and mechanism by which miR-30c regulates lipid metabolism were evaluated in blunt snout bream (Megalobrama amblycephala). Four miR-30c target sites for fas were identified using various prediction tools. miR-30c mimics were transfected into 293 T cells, and dual-luciferase reporter assays were used to evaluate the roles of different fas target sites. When a single target site was mutated, relative luciferase activity was higher than that in the control group, with different activity levels depending on the mutation site. When multiple target sites were mutated, relative luciferase activity increased significantly as the number of mutation sites increased and was the highest when the four sites were mutated simultaneously. The miR-30c agomir was injected into the abdominal cavity of M. amblycephala at various concentrations for analyses of physiological and biochemical parameters in the liver and blood and the expression of genes related to lipid metabolism in the liver. Total cholesterol, free fatty acid, triglyceride, and low density lipoprotein levels were significantly lower after miR-30c agomir injection comparing to the control (P < 0.05). Additionally, the expression levels of genes related to lipid metabolism were significantly lower after miR-30c agomir injection than in the control (P < 0.05). In summary, this study identified four specific miR-30c target sites in the 3' UTR of fas mRNA; the effects of these sites are cumulative, and the redundancy ensures the accurate regulation of fas during evolution. In addition, miR-30c has a negative regulatory effect on fas and regulates lipid metabolism via various genes related to this process. Therefore, the regulation of miR-30c can effectively ameliorate the side effects of a high-fat diet on liver function in M. amblycephala.
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Wang X, Dong Y, Huang Y, Tian H, Zhao H, Wang J, Zhou J, Liu W, Cao X, Li X, Liu X, Liu H, Jiang G. Docosahexaenoic acid-enriched diet improves the flesh quality of freshwater fish ( Megalobrama amblycephala): Evaluation based on nutritional value, texture and flavor. Food Chem 2024; 460:140518. [PMID: 39047487 DOI: 10.1016/j.foodchem.2024.140518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 07/03/2024] [Accepted: 07/17/2024] [Indexed: 07/27/2024]
Abstract
Docosahexaenoic acid (DHA) is a potential regulatory substance for flesh quality of fish, while the related evaluation is still barely. In this study, the effects of DHA-enriched diets on the flesh quality of freshwater fish (Megalobrama amblycephala) were investigated systematically. The sub-adult M. amblycephala were randomly fed with control diet (CON), 0.2% DHA diet (DL) or 0.8% DHA diet (DH). After 12-week feeding trial, the DH group flesh had higher concentrations of essential amino acids and polyunsaturated fatty acids compared to the CON group. Meanwhile, the hardness, springiness, shear force and moisture-holding capacity, as well as the values of umami, richness and sweetness were also improved by DH. The non-targeted metabolomics analysis revealed the key metabolites that may have significantly positive influence on flavor. Collectively, the diet supplementation with 0.8% DHA could achieve the improvement of the flesh quality in terms of nutritional value, texture and flavor in freshwater fish.
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Xiao K, Jia X, Qiang W, Chang L, Liu W, Zhang D. Tryptophan supplements in high-carbohydrate diets by improving insulin response and glucose transport through PI3K-AKT-GLUT2 pathways in blunt snout bream ( Megalobrama amblycephala). J Nutr Biochem 2024; 134:109715. [PMID: 39127308 DOI: 10.1016/j.jnutbio.2024.109715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2024] [Revised: 07/20/2024] [Accepted: 07/29/2024] [Indexed: 08/12/2024]
Abstract
The aim of this experiment was to elucidate the metabolic ramifications of tryptophan supplementation in the context of high-carbohydrate diet-feeding, which is important for improving feeding strategies in aquaculture in order to improve fish carbohydrate metabolism. Juvenile blunt snout bream with an initial mean body mass of 55.0±0.5 g were allocated to consume one of three experimental diets: CN, a normal diet with carbohydrate content of 30% (w/w); HC, a diet with high carbohydrate content of 43% (w/w); and HL, a high-carbohydrate diet to which 0.8% L-tryptophan (L-trp) had been added. These diets were fed for 8 weeks, and the effects of the carbohydrate and tryptophan contents of the diets were assessed. Histological analysis using Hematoxylin and Eosin (H&E) and Oil Red O staining revealed that high-carbohydrate intake was associated with abnormal hepatocyte morphology and excessive liver lipid accumulation, which were notably ameliorated by tryptophan supplementation. A significant increase in plasma glucose, glucagon, AGEs (advanced glycation end products), triglycerides, total cholesterol, and a significant decrease in insulin and hepatic glycogen after a high-carbohydrate diet in terms of plasma indices, compared to the control group. Almost all of them were restored to the normal level in the HL group. The present study might preliminarily suggest that tryptophan supplementation ameliorates the imbalance in glucose metabolism of this species induced by a high-carbohydrate diet. Transcriptomics showed that glucose metabolism under high carbohydrate was mainly regulated by the PI3K-AKT signaling pathway. The mRNA expression and protein levels of GLUT2 also varied with this pathway, which would suggest that sustained activation of this pathway with the addition of tryptophan accelerates glucose transport and insulin secretion under high-carbohydrate diet. Subsequent GTT and ITT experiments have also demonstrated that tryptophan improves glucose tolerance and insulin tolerance in blunt snout bream on a high-carbohydrate diet. In conclusion, these findings elucidate the positive regulatory effect of tryptophan on the PI3K-AKT-GLUT2 pathway under a high carbohydrate diet and provide a theoretical basis for the subsequent rational application of high carbohydrate diets in the future.
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Chen K, Jia Y, He Z, Xie P, Liu H, Gao Z, Wang H. Regulation mechanism of oxidative status, immunity and apoptosis induced by hypoxia and heat exposure via PI3K/Akt signaling pathway in Megalobrama amblycephala. FISH & SHELLFISH IMMUNOLOGY 2024; 155:110027. [PMID: 39551115 DOI: 10.1016/j.fsi.2024.110027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Revised: 11/11/2024] [Accepted: 11/14/2024] [Indexed: 11/19/2024]
Abstract
Megalobrama amblycephala, a main herbivorous fish with notable economic benefits in China, often faces serious challenges to its survival and growth due to hypoxia and heat caused by factors such as global warming and intensive aquaculture. To evaluate the combined effects of these stressors, we performed a two-factor crossover test to assess the impacts of simultaneous exposure to hypoxia (2 mg/L) and heat (35 °C) on oxidative stress, immunity and apoptosis in M. amblycephala. These results showed that hypoxia and heat exposure significantly enhanced the expression of oxygen-sensing and heat shock protein (HSP) genes, hypoxia inducible factor 1α (Hif-1α), HIF-prolyl hydroxylase-2 (phd2) and factor inhibiting Hif-1 (fih-1), as well as hsp70 and hsp90α. Furthermore, M. amblycephala suffering from hypoxia and heat exposure exhibited several changes in liver tissues, with the most severe lesions and up-regulation of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) observed in those subjected to simultaneous exposure. Moreover, the combined hypoxia and heat exposure initially triggered an increase in the activities of total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and catalase (CAT), and glutathione (GSH) contents, followed by a reduction, and the accumulation of malondialdehyde (MDA), which induced oxidative stress. This was accompanied by an increase and subsequent reduction in the contents of alkaline phosphatase (AKP), acid phosphatase (ACP), complement component 3 (C3) and C4, immunoglobulin M (IgM), and interferon-γ (IFN-γ) leading to immunosuppression. Additionally, hypoxia and heat exposure up-regulated the expression of antioxidant enzyme genes (nrf2, cu/zn-sod, mn-sod cat, ho-1, pi3k and gpx-1a), inflammatory genes (interleukin il-1β, il-8 and tnf-α), immunity effectors (igm and lyz), as well as apoptosis genes (casp3, casp8, casp9 and p53) and activated p-Akt/Akt, suggesting apoptosis may be linked with oxidative stress and inflammation and mediated through the PI3K/Akt signaling pathway. In short, the combined hypoxia and heat exposure disrupted homoeostasis in M. amblycephala, with a more pronounced detrimental effect than exposure to either stressor alone These results will contribute to understanding the mechanism of combined exposure to hypoxia and heat in fish and provide a fundamental base for fisheries management.
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Huang Y, Cao X, Liu W, Jiang G, Wang A. Effects of Oxidized Soybean Meal and Oxidized Soybean Oil on the Muscle Oxidative Stability, Flesh Quality, Amino Acid Profile, and Fatty Acid Profile of Megalobrama amblycephala. Antioxidants (Basel) 2024; 13:1356. [PMID: 39594498 PMCID: PMC11591312 DOI: 10.3390/antiox13111356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2024] [Revised: 10/17/2024] [Accepted: 10/21/2024] [Indexed: 11/28/2024] Open
Abstract
This study aimed to investigate the effects of oxidized soybean meal and oxidized soybean oil on the muscle oxidative stability, flesh quality, amino acid profile, and fatty acid profile of blunt snout bream Megalobrama amblycephala. Oxidized soybean meal and oxidized soybean oil were obtained from fresh soybean meal (FSM) and fresh soybean oil (FSO) by heating. In the experimental diet, the proportions of oxidized soybean meal (OSM) and oxidized soybean oil (OSO) were 30% and 4.19%, respectively. The feeding trial was conducted for 8 weeks. The findings revealed that both OSM and OSO reduced glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), catalase (CAT), hardness, chewiness, and oxymyoglobin (OxyMb) and elevated the content of malondialdehyde (MDA), protein carbonyl (PC), and metmyoglobin (MetMb) in the muscle. OSM notably decreased the content of muscle essential amino acids (EAAs), nonessential amino acids (NEAAs), delicious amino acids (DAAs), and total amino acids (TAAs) compared with CON and OSO. Compared with CON and OSM, OSO significantly reduced the content of elaidic acid (C18:1n9t), linoelaidic acid (C18:2n6c), polyunsaturated fatty acids (PUFAs), ω-6 PUFAs, and the ratio of ω-6/ω-3, while stearic acid (C18:0), γ-linolenic acid (C18:3n6) and saturated fatty acids (SFAs) were significantly elevated. In conclusion, this study demonstrated that both OSM and OSO negatively impacted muscle antioxidant capacity and flesh quality. Moreover, OSM adversely affected the amino acid profile of the muscle, while OSO impaired the fatty acid profile.
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Xiong W, Jiang GZ, He CF, Hua HK, Du MT, Huang WT, Xu HT, Zhou MT, Wang X, Guo HX, Wang AM, Sun SZ, Liu WB. Recombinant Bacillus subtilis expressing functional peptide and its effect on blunt snout bream ( Megalobrama amblycephala) in two state of stress. FISH & SHELLFISH IMMUNOLOGY 2024; 154:109980. [PMID: 39461393 DOI: 10.1016/j.fsi.2024.109980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 10/17/2024] [Accepted: 10/22/2024] [Indexed: 10/29/2024]
Abstract
This study was conducted to investigate the effects of recombinant Bacillus subtilis CM66-P4' (secreting P4, which related to previous research in this laboratory) on the antioxidant capacity and immune function of blunt snout bream (Megalobrama amblycephala) through in vitro and in vivo experiment. The culture experiment was divided into 3 groups, including control group (CG, with no additional bacteria), original bacteria group (OBG, with 2 × 109 CFU/kg Bacillus subtilis CM66) and recombinant bacteria group (RBG, with 2 × 109 CFU/kg Bacillus subtilis CM66-P4'). After 8 weeks of feeding, a part of the fish were subjected to fishing stress, and the rest were subjected to starvation stress test. Blood samples were collected for the determination of immune and stress-related indexes. The hepatocytes were divided into control group (CG) and experiment group with P4 peptide (LTG and HTG). The cells were collected after starvation treatment and the expression of related genes was detected. The results showed as follows: compared with the CG group, the gene expressions of hepatocytic hsp60 and hsp70 in the LTG and HTG groups were significantly suppressed after 24 h starvation stress (P < 0.05). The content of MDA, the activities of AKP and ALT in OBG group were significantly changed after 30 days starvation (P < 0.05), while the indexes in RBG group had no significant change. The changes of plasma cortisol, malondialdehyde (MDA) and Immunoglobulin M (IgM) in CG and OBG groups were significantly changed at 4 h after fishing stress (P < 0.05), while the indexes in RBG group was not. In conclusion, this study confirmed that Bacillus subtilis CM66-P4' has great potential in preventing adverse effects of stress on aquatic livestock.
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Xia H, Liu L, Zhou W, Ding C, Liu H, Lei T, Chen F, Liu S, Yu J, Yang P, Yu Y. Immune response to Aeromonas hydrophila and molecular characterization of polymeric immunoglobulin receptor in juvenile Megalobrama amblycephala. FISH & SHELLFISH IMMUNOLOGY 2024; 153:109821. [PMID: 39117129 DOI: 10.1016/j.fsi.2024.109821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2024] [Revised: 08/04/2024] [Accepted: 08/06/2024] [Indexed: 08/10/2024]
Abstract
Polymeric immunoglobulin receptor (pIgR) is an important immune factor in the mucosal immune system of fish, which plays a key role in mediating the secretion and transport of immunoglobulin into mucus. In this study, the full-length cDNA sequence of Megalobrama amblycephala pIgR gene was firstly cloned and the immune response to Aeromonas hydrophila was detected. After being challenged by Aeromonas hydrophila at 3 d, significantly pathological features were observed in intestine, head kidney, spleen, liver and gill of Megalobrama amblycephala. The content of lysozyme (Lys) and the activities of acid phosphatase (ACP) and alkaline phosphatase (AKP) increased significantly at 1 d and reached the peak at 3 d, and the activities of total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-PX) and catalase (CAT) in serum reached the peak at 5 d and 7 d after infection, respectively. The expression level of IL-1β gene reached the peak at 3 d in intestine, 5 d in gill and spleen, 7 d in head kidney and liver of Megalobrama amblycephala after infected by Aeromonas hydrophila, respectively. The TNF-α gene expression reached the peak at 3 d in intestine and gill, 5 d in head kidney and spleen, 7 d in liver after infection, respectively. The experimental results showed that the infection of Aeromonas hydrophila caused the pathological changes of immune-related tissues and triggered the inflammation responses. The full-length cDNA sequence of Megalobrama amblycephala pIgR was 1828 bp, and its open reading frame (ORF) was 1023 bp, encoding 340 amino acids. The pIgR of Megalobrama amblycephala has a signal peptide sequence, followed by extracellular region, transmembrane region and intracellular region. The extracellular region includes two Ig-like domains (ILDs), and its tertiary structure is twisted "L". The phylogenetic tree was constructed using the adjacency method, and the pIgR genes of Megalobrama amblycephala and cyprinidae fish were clustered into a single branch. Quantitative real-time PCR (qRT-PCR) was used to detect the expression of pIgR gene in different tissues of Megalobrama amblycephala. The expression level of pIgR gene was the highest in liver, followed by intestine, head kidney, skin, middle kidney and spleen, lower in heart, gill and brain, and the lowest in muscle. After being infected by Aeromonas hydrophila, the expression level of Megalobrama amblycephala pIgR gene in intestine, head kidney, spleen, liver and gill showed a trend of increasing first and then decreasing within 28 d. The pIgR gene expression reached the peak in mucosal immune-related tissues (gill and intestine) was earlier than that in systemic immune-related tissues (head kidney and spleen), and the relative expression level of pIgR gene at peak in intestine (12.3 fold) was higher than that in head kidney (3.73 fold) and spleen (7.84 fold). These results suggested that Megalobrama amblycephala pIgR might play an important role in the mucosal immune system to against Aeromonas hydrophila infection.
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Pan W, Wang F, Xu J, Li J, Gao J, Zhao Y, Wang Q. Betaine Supplementation Into High-Carbohydrate Diets Improves Feed Efficiency and Liver Health of Megalobrama amblycephala by Increasing Taurine Synthesis. AQUACULTURE NUTRITION 2024; 2024:9632883. [PMID: 39555516 PMCID: PMC11469934 DOI: 10.1155/2024/9632883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Accepted: 07/23/2024] [Indexed: 11/19/2024]
Abstract
Dietary betaine supplementation has been reported to alleviate the adverse effects of high-carbohydrate diets on Megalobrama amblycephala, while the regulatory mechanism remains largely unknown. In the present study, a 79-day feeding trial was conducted with 450 juvenile Megalobrama amblycephala (average weight 6.75 ± 0.10 g), which were fed with five high-carbohydrate diets (43%) supplementing betaine at 0% (CD group), 0.2% (0.2Bet group), 0.4% (0.4Bet group), 0.8% (0.8Bet group), and 1.6% (1.6Bet group), respectively. Results showed M. amblycephala in 0.8Bet group exhibited the best growth performance, indicated by the largest weight gain ratio (142.88%) and least feed conversion ratio (1.63). Moreover, liver health was promoted in 0.8Bet group, with decreased number of non-nucleated cells and less lipid accumulation, which was accompanied by the lowest hepatosomatic index (1.38%). In order to further illustrate the regulatory mechanism, metabolites assay indicated that dietary betaine supplementation significantly increased plasma contents of methionine, serine, hypotaurine, and taurine, but did not affect plasma contents of cystathionine, cystine, or cysteic acid. Accordingly, the mRNA expressions of cysteine sulfinate decarboxylase in cysteine sulfinic acid pathway and cysteamine dioxygenase (ADO) in sulfinic acid (CS) pathway, which were both involved in taurine synthesis, were also upregulated in the liver. Meanwhile, the microbial communities in M. amblycephala intestine were more stable and uniform with betaine supplementation. Therefore, dietary betaine supplementation may exert its protective roles in improving feed efficiency and liver health of M. amblycephala via promoting de novo taurine synthesis and stabilizing intestinal microbial communities.
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Xie R, Guo H, Luo Y, Huang W, Ruan Z, Liu W. New Insights into the Mechanism by Which the Pituitary Gland Copes with Hypoxia Stress Based on a Transcriptomic Analysis of Megalobrama amblycephala. Genes (Basel) 2024; 15:987. [PMID: 39202348 PMCID: PMC11353591 DOI: 10.3390/genes15080987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2024] [Revised: 07/18/2024] [Accepted: 07/24/2024] [Indexed: 09/03/2024] Open
Abstract
Hypoxia is a common environmental stressor in aquatic ecosystems, and during the cultivation process, Megalobrama amblycephala is prone to death because it is hypoxia-intolerant, which brings huge economic losses to farmers. The pituitary gland is a crucial endocrine gland in fish, and it is mainly involved in the secretion, storage, and regulation of hormones. In the present study, we compared the transcriptional responses to serious hypoxia in the pituitary gland among hypoxia-sensitive (HS) and hypoxia-tolerant (HT) M. amblycephala and a control group that received a normal oxygen supply (C0). The fish were categorized according to the time required to lose balance during a hypoxia treatment. A total of 129,251,170 raw reads were obtained. After raw sequence filtering, 43,461,745, 42,609,567, and 42,730,282 clean reads were obtained for the HS, HT, and C0 groups, respectively. A transcriptomic comparison revealed 1234 genes that were differentially expressed in C0 vs. HS, while 1646 differentially expressed genes were obtained for C0 vs. HT. In addition, the results for HS vs. HT showed that 367 upregulated and 41 downregulated differentially expressed genes were obtained for a total of 408 differentially expressed genes. A KEGG analysis of C0 vs. HS, C0 vs. HT, and HS vs. HT identified 315, 322, and 219 enriched pathways, respectively. Similar hypoxia-induced transcription patterns suggested that the downregulated DEGs and enriched pathways were related to pathways of neurodegeneration in multiple diseases, pathways in cancer, thermogenesis, microRNAs in cancer, diabetic cardiomyopathy, and renin secretion. However, in the upregulated DEGs, the PI3K-Akt signaling pathway (C0 vs. HS), microRNAs in cancer (C0 vs. HT), and HIF-1 signaling pathway (HS vs. HT) were significantly enriched. There is a lack of clarity regarding the role of the pituitary gland in hypoxic stress. These results not only provide new insights into the mechanism by which pituitary tissue copes with hypoxia stress in M. amblycephala but also offer a basis for breeding M. amblycephala with hypoxia-resistant traits.
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Mu Q, Miao L, Qian L, Lin Y, Jiang W, Ge X. Regulation of sirt1 and foxO1 in glucose metabolism of Megalobrama amblycephala. Gene 2024; 903:148172. [PMID: 38242371 DOI: 10.1016/j.gene.2024.148172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 12/19/2023] [Accepted: 01/16/2024] [Indexed: 01/21/2024]
Abstract
Both silent information regulator 2 homolog 1 (sirt1) and forkhead box transcription factor 1 (foxO1) are crucial transcription factors involved in glucolipid metabolism and energy regulation. The presnt study aimed to understand their regulatory roles in glucose metabolism. Molecular cloning and sequencing of sirt1 gene of Megalobrama amblycephala (masirt1) was conducted and cellular localization of both the factors were analysed. Their effects and action patterns in the glucose metabolism of Megalobrama amblycephala (M. amblycephala) were investigated through acute and long-term glucose tolerance assays. The results revealed that the full-length masirt1 cDNA sequence was 2350 bp and closely related to Sinocyclocheilus rhinocerous. Sirt1 and foxO1 were found to be mutually dependent and localized in the nucleus. Acute glucose tolerance tests revealed that the expression levels of both factors in the liver of M. amblycephala showed an initial increase followed by a decrease. Plasma glucose levels in M. amblycephala significantly increased at 2 and 12 h (P < 0.05). In a long-term breeding experiment with high-sugar feeding, the expressions of the sirt1 and foxO1 genes in the kidney and intestine of M. amblycephala exhibited synergistic changes. The 51WS groups had significantly higher levels of sirt1 and foxO1 gene expression in the kidney and intestine compared to the 0WS and 17WS groups (P < 0.05). Overall, masirt1 is evolutionarily highly conserved, and the interaction site of sirt1 and foxO1 is located in the nucleus. In long-term hyperglycemic regulation, sirt1 and foxO1 exhibit synergistic regulatory effects in the kidney and intestine of M. amblycephala. This study provides insights into how sirt1 and foxO1 regulate glucose metabolism in M. amblycephala.
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Zou X, Liu Q, Guan Q, Zhao M, Zhu X, Pan Y, Liu L, Gao Z. Muscle Fiber Characteristics and Transcriptome Analysis in Slow- and Fast-Growing Megalobrama amblycephala. Genes (Basel) 2024; 15:179. [PMID: 38397169 PMCID: PMC10888202 DOI: 10.3390/genes15020179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 01/25/2024] [Accepted: 01/26/2024] [Indexed: 02/25/2024] Open
Abstract
Growth is an important trait in aquaculture that is influenced by various factors, among which genetic regulation plays a crucial role. Megalobrama amblycephala, one of the most important freshwater species in China, exhibits wide variations in body mass among individuals of the same age within the same pool. But the molecular mechanisms underlying wide variation in body mass remain unclear. Here, we performed muscle histological and transcriptome analysis of muscle tissues from Fast-Growing (FG) and Slow-Growing (SG) M. amblycephala at the age of 4 months old (4 mo) and 10 months old (10 mo) to elucidate its muscle development and growth mechanism. The muscle histological analysis showed smaller diameter and higher total number of muscle fibers in FG compared to SG at 4 mo, while larger diameter and total number of muscle fibers were detected in FG at 10 mo. The transcriptome analysis of muscle tissue detected 1171 differentially expressed genes (DEGs) between FG and SG at 4 mo, and 718 DEGs between FG and SG at 10 mo. Furthermore, 44 DEGs were consistently up-regulated in FG at both 4 mo and 10 mo. Up-regulated DEGs in FG at 4 mo were mainly enriched in the pathways related to cell proliferation, while down-regulated DEGs were significantly enriched in cell fusion and muscle contraction. Up-regulated DEGs in FG at 10 mo were mainly enriched in the pathways related to cell proliferation and protein synthesis. Therefore, these results provide novel insights into the molecular mechanism of M. amblycephala muscle growth at different stages, and will be of great guiding significance to promote the fast growth of M. amblycephala.
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Zhang A, Guo X, Bao K, Wu D, Liu H, Gao Z, Wang H. Molecular Characterization and Expression Changes of the bcl2l13 Gene in Response to Hypoxia in Megalobrama amblycephala. Curr Issues Mol Biol 2024; 46:1136-1149. [PMID: 38392190 PMCID: PMC10887287 DOI: 10.3390/cimb46020072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 12/17/2023] [Accepted: 01/16/2024] [Indexed: 02/24/2024] Open
Abstract
Hypoxia is a unique environmental stress, which not only reflects the insufficient oxygen supply of cells and tissues, but also occurs in various physiological and pathological environments. Mitophagy as a selective autophagy can recover and utilize damaged organelles and misfolded proteins to ensure normal cell functions and promote cell survival. Bcl2l13 (B-cell lymphoma-2 like 13) is reported to induce mitophagy as a functional mammalian homolog of Atg32. However, the function of the bcl2l13 gene is still unclear in fish. Here the sequence and structure of the bcl2l13 gene in Megalobrama amblycephala were identified and showed that bcl2l13 contained an open reading frame (ORF) of 1458 bp for encoding 485 aa. Amino acid sequence analysis indicated that Bcl2l13, as a typical anti-apoptotic protein of the Bcl2 family, contained four BH domains, one BHNo domain, and one TM domain. Further study showed that Bcl2l13 was mainly located in the mitochondria, while its localization was changed within the whole cell after the TM domain was deleted. Real-time PCR analysis revealed that bcl2l13 showed higher expression levels in early embryos. After hypoxia treatment, the mRNA levels of the bcl2l13 and autophagy-related genes were significantly up-regulated in most detected tissues, and the bcl2l13 transcription was regulated by Hif-1α mediated pathway. Additionally, the transcription activity of the bcl2l13 promoter was further analyzed using luciferase reporter assays and showed the highest activity in the promoter region from -475 to +111. These results indicated that bcl2l13 may play important roles in embryogenesis and hypoxia mediated autophagy in fish.
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Jiang W, Lin Y, Qian L, Lu S, Shen H, Ge X, Miao L. Mulberry Leaf Polysaccharides Attenuate Oxidative Stress Injury in Peripheral Blood Leukocytes by Regulating Endoplasmic Reticulum Stress. Antioxidants (Basel) 2024; 13:136. [PMID: 38397734 PMCID: PMC10886326 DOI: 10.3390/antiox13020136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 12/28/2023] [Accepted: 01/09/2024] [Indexed: 02/25/2024] Open
Abstract
The present study assessed the protective effects and underlying mechanisms of mulberry leaf polysaccharides (MLPs) against hydrogen peroxide (H2O2)-induced oxidative stress injury in the peripheral blood leukocytes (PBLs) of Megalobrama amblycephala. Five treatment groups were established in vitro: the NC group (PBLs incubated in an RPMI-1640 complete medium for 4 h), the HP group (PBLs incubated in an RPMI-1640 complete medium for 3 h, and then stimulated with 100 μM of H2O2 for 1 h), and the 50/100/200-MLP pre-treatment groups (PBLs were pre-treated with MLPs (50, 100, and 200 μg/mL) for 3 h, and then stimulated with 100 μM of H2O2 for 1 h). The results showed that MLP pre-treatment dose-dependently enhanced PBLs' antioxidant capacities. The 200 μg/mL MLP pre-treatment effectively protected the antioxidant system of PBLs from H2O2-induced oxidative damage by reducing the malondialdehyde content and lactic dehydrogenase cytotoxicity, and increasing catalase and superoxide dismutase activities (p < 0.05). The over-production of reactive oxygen species, depletion of nicotinamide adenine dinucleotide phosphate, and collapse of the mitochondrial membrane potential were significantly inhibited in the 200-MLP pre-treatment group (p < 0.05). The expressions of endoplasmic reticulum stress-related genes (forkhead box O1α (foxO1α), binding immunoglobulin protein (bip), activating transcription factor 6 (atf6), and C/EBP-homologous protein (chop)), Ca2+ transport-related genes (voltage-dependent anion-selective channel 1 (vdac1), mitofusin 2 (mfn2), and mitochondrial Ca2+ uniporter (mcu)), and interleukin 6 (il-6) and bcl2-associated x (bax) were significantly lower in the 200-MLP pre-treatment group than in the HP group (p < 0.05), which rebounded to normal levels in the NC group (p > 0.05). These results indicated that MLP pre-treatment attenuated H2O2-induced PBL oxidative damage in the M. amblycephala by inhibiting endoplasmic reticulum stress and maintaining mitochondrial function. These findings also support the possibility that MLPs can be exploited as a natural dietary supplement for M. amblycephala, as they protect against oxidative damage.
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Wang Q, Zhao X, Liu Y, Zheng J, Cui H, Wang H, Ding H, Liu H, Ding Z. Characterization and Expression Analysis of Genes from Megalobrama amblycephala Encoding Hemoglobins with Extracellular Microbicidal Activity. Genes (Basel) 2023; 14:1972. [PMID: 37895322 PMCID: PMC10606352 DOI: 10.3390/genes14101972] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 10/18/2023] [Accepted: 10/20/2023] [Indexed: 10/29/2023] Open
Abstract
Hemoglobin (Hb) usually comprises two α and two β subunits, forming a tetramer responsible for oxygen transportation and storage. Few studies have elucidated fish hemoglobin immune functions. Megalobrama amblycephala is a freshwater-cultured fish prevalent in China. We identified two M. amblycephala hemoglobin subunits and analyzed their expression patterns and antibacterial activities. The respective full-length cDNA sequences of the M. amblycephala Hb α (MaHbα) and β (MaHbβ) subunits were 588 and 603 bp, encoding 143 and 148 amino acids. MaHbα and MaHbβ were highly homologous to hemoglobins from other fish, displaying typical globin-like domains, most heme-binding sites, and tetramer interface regions highly conserved in teleosts. In phylogenetic analyses, the hemoglobin genes from M. amblycephala and other cypriniformes clustered into one branch, and those from other fishes and mammals clustered into other branches, revealing fish hemoglobin conservation. These M. amblycephala Hb subunits exhibit different expression patterns in various tissues and during development. MaHbα is mainly expressed in the blood and brain, while MaHbβ gene expression is highest in the muscle. MaHbα expression was detectable and abundant post-fertilization, with levels fluctuating during the developmental stages. MaHbβ expression began at 3 dph and gradually increased. Expression of both M. amblycephala Hb subunits was down-regulated in most examined tissues and time points post-Aeromonas hydrophila infection, which might be due to red blood cell (RBC) and hematopoietic organ damage. Synthetic MaHbα and MaHbβ peptides showed excellent antimicrobial activities, which could inhibit survival and growth in five aquatic pathogens. Two M. amblycephala hemoglobin subunits were identified, and their expression patterns and antibacterial activities were analyzed, thereby providing a basis for the understanding of evolution and functions of fish hemoglobins.
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Zhang YY, Xu P, Wang XL, Song LP, Wu J, Wang BL, Hu B, Mao SQ, Liu B, Ge XP. Study of Dietary Emodin on Immune Defense in Megalobrama amblycephala against Aeromonas hydrophila. Vet Sci 2023; 10:588. [PMID: 37756110 PMCID: PMC10537799 DOI: 10.3390/vetsci10090588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 09/01/2023] [Accepted: 09/19/2023] [Indexed: 09/28/2023] Open
Abstract
This experiment aimed to investigate the effects of emodin on the total bacterial count and immune response in various tissues of Wuchang bream infected with A. hydrophila. The experimental diets were made by supplementing emodin at 0, 30, 100, and 150 mg kg-1 to basal (control) diet, respectively, and fed to fish with an initial weight of 50.4 ± 2.35 g. All fish were divided into five experimental groups: uninfected fish fed with basal control diet (negative control, NC), infected fish fed with the diet supplemented with 0 (positive control group, PC), 30 (30), 100 (100), and 150 mg/kg (150) of emodin. The fish were reared for 14 days and sampled at different time points. The results showed that the total bacterial count in the kidney, blood, and liver tissues of Wuchang bream infected with A. hydrophila was significantly affected by the supplementation and feeding time of emodin. At the beginning of the experiment, the difference in total bacterial count among the groups was not significant. On day 1, the total bacterial count in all groups was significantly higher (p < 0.05) than that in the negative control group. On day 4, the total bacterial count in all the emodin groups was significantly reduced, and the best bactericidal effect was observed in the 100 mg kg-1 group. In addition, emodin had a significant effect on the immune response of Wuchang bream after infection with A. hydrophila (p < 0.05). Compared with the other groups, the respiratory burst activity, tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1) content, and white blood cell count (WBC) in the 100 and 150 mg kg-1 groups could be restored to normal levels in the shortest time (p < 0.05). Furthermore, this study also measured the complement alternative pathway activity (ACH50), plasma superoxide dismutase (SOD) activity, and malondialdehyde (MDA) content of the fish. The results showed that supplying 100 mg kg-1 emodin to the diet could significantly (p < 0.05) increase the ACH50 activity of the fish. Compared with the positive control (PC) group, the addition of emodin to the diet can inhibit the decrease in SOD activity and the increase in MDA content in the plasma of infected Wuchang bream. In conclusion, supplying 100 mg kg-1 emodin to the diet can enhance the ability of Wuchang bream to resist A. hydrophila infection by reducing the total bacterial count in tissues, increasing the activity of related immune enzymes, and promoting the secretion of cytokines. This provides a theoretical basis for production practice.
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Liu Y, Wang Z, Wang W, Liu B, Li C, Sun Y, Cao J, Xia K, Yang M, Yan J. Characterization and functional analysis of a novel C-type lectin in blunt snout bream ( Megalobrama amblycephala). FISH & SHELLFISH IMMUNOLOGY 2023; 140:108966. [PMID: 37482206 DOI: 10.1016/j.fsi.2023.108966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 06/28/2023] [Accepted: 07/20/2023] [Indexed: 07/25/2023]
Abstract
C-type lectins, one of the pattern recognition receptors (PRRs), play significant roles in innate immune responses through binding to the pathogen-associated molecular patterns (PAMPs) presented on surfaces of microorganisms. Here, a novel C-type lectin (named as MaCTL) from blunt snout bream (Megalobrama amblycephala) was cloned and characterized. The open reading frame (ORF) of MaCTL is 573 bp long encoding a putative protein of 190 amino acids (aa), which contains a typical feature of signal peptide at 1-23 aa, a characteristic CRD domain at 45-178 aa and a WND/EPN motif that is required for carbohydrates-binding specificity. Phylogenetic analysis indicated that MaCTL is a novel member of CTL family and possessed the highest similarity to that of grass carp (92.11%). The qRT-PCR analysis revealed that MaCTL expressed widely in all examined normal tissues, including heart, liver, spleen, kidney, head-kidney, gill, intestine and muscle, with the higher expression in the spleen, liver and muscle. The expression of MaCTL in spleen was significantly elevated, peaking at 9 h and 6 h after LPS stimulation and Aeromonas hydrophila challenge, respectively, suggesting its association with involvement in innate immune response. The recombinant MaCTL protein (rMaCTL) agglutinated markedly both Gram-positive (Staphylococcus aureus) and Gram-negative bacteria, including Escherichia coli, Vibrio anguillarum, Vibrio vulnificus and Aeromonas hydrophila, in a Ca2+-dependent manner. Meanwhile, rMaCTL showed the binding effects on the five bacteria and four carbohydrates, such as glucose, surose, LPS and PGN. Moreover, rMaCTL could remarkably inhibit the growth of three types of bacteria in vitro. Overall, the results obtained above demonstrated firmly that MaCTL binds to carbohydrates on the surface of diverse pathogens as a PRR and elicits antimicrobial responses, which shed new light on a better understanding of antibacterial functions of CTLs in teleost fish.
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Sun Q, Wang H, Liu H. Identification of long non-coding RNA MSTRG.5748.1 and MSTRG.7894.1 from Megalobrama amblycephala and their potential roles in innate immunity. FISH & SHELLFISH IMMUNOLOGY 2023; 140:108949. [PMID: 37453493 DOI: 10.1016/j.fsi.2023.108949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 07/08/2023] [Accepted: 07/13/2023] [Indexed: 07/18/2023]
Abstract
Megalobrama amblycephala is one of the most economically important freshwater fish in China, and the bacterial septicemia caused by Aeromonas hydrophila is a serious threat to the breeding industry of M. amblycephala. Unfortunately, the characterization of long noncoding RNA (lncRNA) in response to A. hydrophila infection has not been performed in M. amblycephala. To better understand the biological significance of lncRNA in the immune system, we identified two lncRNA, named MSTRG.5748.1 and MSTRG.7894.1, as playing critical roles in the antibacterial response of M. amblycephala. After separating the nucleus and cytoplasm of the hepatocytes from M. amblycephala, cellular localization of MSTRG.5748.1 and MSTRG.7894.1 was performed to predict their functions. The results showed that MSTRG.5748.1 was mainly expressed in the nucleus, suggesting that its functions are mostly to regulate the expression of downstream genes through epistasis and transcription. MSTRG.7894.1 existed in both the nucleus and cytoplasm, which indicated that it has many regulatory modes. qPCR analysis showed that MSTRG.5748.1 and MSTRG.7894.1 were expressed in the immune-related organs of M. amblycephala, and significantly changed in the liver after A. hydrophila infection. RNA-seq analysis revealed that differentially expressed genes (DEGs) were mainly enriched in antigen processing and presentation via MHC class I, RIG-I-like receptor (RLR) signaling pathway, and IFN-related pathway, and a large number of pathway-related genes were significantly regulated after lncRNA overexpression in muscle cell of M. amblycephala. Overexpression of MSTRG.5748.1 and MSTRG.7894.1 significantly inhibited the expression of STING and IFN, significantly upregulated muscle cell viability, and promoted cell proliferation by targeting STING and IFN.
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Zhang L, Liu Z, Deng Y, He C, Liu W, Li X. The Benefits of Nanosized Magnesium Oxide in Fish Megalobrama amblycephala: Evidence in Growth Performance, Redox Defense, Glucose Metabolism, and Magnesium Homeostasis. Antioxidants (Basel) 2023; 12:1350. [PMID: 37507890 PMCID: PMC10376070 DOI: 10.3390/antiox12071350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 06/20/2023] [Accepted: 06/25/2023] [Indexed: 07/30/2023] Open
Abstract
This study evaluated the effects of dietary magnesium oxide nanoparticles (MgO NPs) on the growth, redox defense, glucose metabolism, and magnesium homeostasis in blunt snout bream. Fish (12.42 ± 0.33 g) were fed seven diets containing graded levels of MgO NPs (0, 60, 120, 240, 480, 960, and 1920 mg/kg) for 12 weeks. Whole-body Mg retention decreased significantly as the dietary Mg increased. As dietary MgO NPs levels reached 120 mg/kg, the growth performance and feed utilization remarkably improved. When added at 240 mg/kg, oxidative stress was significantly reduced evidenced by the increased Mn-sod transcription and the decreased CAT and GSH-Px activities and the MDA content. Meanwhile, it enhanced glucose transport, glycolysis, and glycogen synthesis, while inhibiting gluconeogenesis, as was characterized by the increased transcriptions of glut2, gk, and pk, and the decreased transcriptions of fbpase and g6pase. In addition, the supplementation of 120 mg/kg MgO NPs promoted Mg transport marked by a significant increase in the protein expressions of TRMP7, S41A3, and CNNM1. In conclusion, the moderate supplementation of MgO NPs improved the growth performance, reduced hepatic oxidative stress, and promoted glucose transport, glycolysis, glycogen synthesis, and magnesium homeostasis in fish while inhibiting glu.
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Li H, Li H, Liu Y, Zheng Y, Zhang M, Wang X, Cui H, Wang H, Zhao X, Chen X, Cheng H, Xu J, Ding Z. Molecular characterization and expression patterns of CXCL8 gene from blunt snout bream ( Megalobrama amblycephala) and its chemotactic effects on macrophages and neutrophils. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2023; 142:104658. [PMID: 36758661 DOI: 10.1016/j.dci.2023.104658] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 01/16/2023] [Accepted: 02/06/2023] [Indexed: 06/18/2023]
Abstract
CXCL8 is a typical CXC-type chemokine, which mediates the migration of immune cells from blood vessels to the site of inflammation or injury to clear pathogenic microorganisms and repair damaged tissues. In this study, Megalobrama amblycephala CXCL8 (MaCXCL8) gene was identified and characterized. Sequence analysis showed that the deduced MaCXCL8 protein possessed the typical structure of CXCL8 from other species, with the characteristic CXC cysteine residues in the N-terminal and accompanied by a DLR motif (Asp-Leu-Arg motif). Phylogenetic analysis revealed that MaCXCL8 was homologous to that of Ctenopharyngodon idella and other cyprinid fishes. MaCXCL8 gene was expressed in all detected healthy tissues, with the highest expression levels in the spleen, and its expression was significantly up-regulated upon the challenge of Aeromonas hydrophila and Lipopolysaccharide (LPS) both in juvenile M. amblycephala tissues and primary macrophages. The immunohistochemical assay showed that MaCXCL8 was mainly distributed in the nucleus and cytoplasm, and its expression levels increased observably with the prolongation of bacterial infection. In addition, recombinant MaCXCL8 protein exhibited significant chemotactic effects on neutrophils and macrophages. In conclusion, MaCXCL8 is involved in the immune response of M. amblycephala, and these findings will be helpful to understand the biological roles of MaCXCL8 and provide a theoretical basis for the prevention and control of fish bacterial diseases.
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Hua Y, Huang W, Wang F, Jing Z, Li J, Wang Q, Zhao Y. Metabolites, gene expression, and gut microbiota profiles suggest the putative mechanisms via which dietary creatine increases the serum taurine and g-ABA contents in Megalobrama amblycephala. FISH PHYSIOLOGY AND BIOCHEMISTRY 2023; 49:253-274. [PMID: 36897433 DOI: 10.1007/s10695-023-01177-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 03/01/2023] [Indexed: 05/04/2023]
Abstract
A 90-day experiment was conducted to explore the effects of creatine on growth performance, liver health status, metabolites, and gut microbiota in Megalobrama amblycephala. There were 6 treatments as follows: control (CD, 29.41% carbohydrates), high carbohydrate (HCD, 38.14% carbohydrates), betaine (BET, 1.2% betaine + 39.76% carbohydrates), creatine 1 (CRE1, 0.5% creatine + 1.2% betaine + 39.29% carbohydrates), creatine 2 (CRE2, 1% creatine + 1.2% betaine + 39.50% carbohydrates), and creatine 3 (CRE3, 2% creatine + 1.2% betaine + 39.44% carbohydrates). The results showed that supplementing creatine and betaine together reduced the feed conversion ratio significantly (P < 0.05, compared to CD and HCD) and improved liver health (compared to HCD). Compared with the BET group, dietary creatine significantly increased the abundances of Firmicutes, Bacteroidota, ZOR0006, and Bacteroides and decreased the abundances of Proteobacteria, Fusobacteriota, Vibrio, Crenobacter, and Shewanella in the CRE1 group. Dietary creatine increased the content of taurine, arginine, ornithine, γ-aminobutyric acid (g-ABA), and creatine (CRE1 vs. BET group) and the expression of creatine kinase (ck), sulfinoalanine decarboxylase (csad), guanidinoacetate N-methyltransferase (gamt), glycine amidinotransferase (gatm), agmatinase (agmat), diamine oxidase1 (aoc1), and glutamate decarboxylase (gad) in the CRE1 group. Overall, these results suggested that dietary supplementation of creatine (0.5-2%) did not affect the growth performance, but it altered the gut microbial composition at the phylum and genus levels, which might be beneficial to the gut health of M. amblycephala; dietary creatine also increased the serum content of taurine by enhancing the expressions of ck and csad and increased the serum content of g-ABA by enhancing the arginine content and the expressions of gatm, agmat, gad, and aoc1.
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Sun Q, Zhang J, Wang J, Wang H, Gao Z, Liu H. Janus kinase 1 in Megalobrama amblycephala: Identification, phylogenetic analysis and expression profiling after Aeromonas hydrophila infection. FISH & SHELLFISH IMMUNOLOGY 2023; 135:108620. [PMID: 36841516 DOI: 10.1016/j.fsi.2023.108620] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 02/07/2023] [Accepted: 02/15/2023] [Indexed: 06/18/2023]
Abstract
Janus kinase 1 (JAK1), a member of the JAK family, plays an essential and non-redundant role in the mammalian immune system. However, the potential role of JAK1 in fish immune response remains largely unclear. In the present study, the JAK1 gene of Megalobrama amblycephala (MamJAK1) was identified and characterized. The open reading frame (ORF) of MamJAK1 was 3462 bp, encoding 1153 amino acids. MamJAK1 consists of four common domains of the JAK family, including B41, SH2, STyrKc (a pseudo kinase domain), and TyrKc (a kinase domain). Phylogenetic analysis showed that JAK1s are divided into two evolutionary clades, one containing fish JAK1s, and the other containing JAK1s from other vertebrates. The results of quantitative real-time PCR (qPCR) showed that in healthy M. amblycephala, MamJAK1 mRNA was highest expressed in blood, followed by spleen, intestine and mid-kidney, and lowly expressed in other tissues including gill, liver, head kidney, muscle, brain and heart. After Aeromonas hydrophila infection, the expression of MamJAK1 mRNA was significantly induced in four selected tissues including spleen, mid-kidney, liver and intestine, reaching a peak at 24 hpi (hour post infection) in spleen and mid-kidney, at 12 hpi in liver and at 4 hpi in intestine, and then the expression level was restricted to control levels at 72 or 120 hpi. In addition, the results of Western blot showed that the phosphorylation level of MamJAK1 protein in spleen and mid-kidney increased significantly after A. hydrophila infection, although MamJAK1 protein did not change obviously. Further, the JAK1 phosphorylation in Ctenopharyngodon idellus kidney (CIK) cells was found to be significantly induced by LPS stimulation and IL-6R over-expression. The results above suggest that MamJAK1 may play an essential role in the immune response against bacterial infection through the IL-6R mediated JAK1/STAT signaling pathway, which further deepen our understanding of JAK1 and provides a potential target for the treatment and prevention of bacterial diseases in teleost.
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Zhao SS, Su XL, Yang HQ, Zheng GD, Zou SM. Functional exploration of SNP mutations in HIF2αb gene correlated with hypoxia tolerance in blunt snout bream ( Megalobrama amblycephala). FISH PHYSIOLOGY AND BIOCHEMISTRY 2023; 49:239-251. [PMID: 36859574 DOI: 10.1007/s10695-023-01173-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 02/13/2023] [Indexed: 05/04/2023]
Abstract
Blunt snout bream (Megalobrama amblycephala) is sensitive to hypoxia environment. Hypoxia-inducible factor (HIF) is the most critical factor in the HIF pathway, which strictly regulates the hypoxia stress process of fish. In this study, we found six hifα genes in blunt snout bream that demonstrated different expressions under hypoxia conditions. In HEK293T cells, all six hifαs were detected to activate the HRE region by luciferase reporter assay. More importantly, we identified two linkage-disequilibrium SNP sites at exon 203 and 752 of the hif2αb gene in blunt snout bream. Haplotype II (A203A752) and its homozygous diplotype II (A203A203A752A752) appeared frequently in a selected strain of blunt snout bream with hypoxia tolerance. Diplotype II has a lower oxygen tension threshold for loss of equilibrium (LOEcrit) over a similar range of temperatures. Moreover, its erythrocyte number increased significantly (p < 0.05) than those in diplotype I and diplotype III strains at 48 h of hypoxia. The enzymes related with hypoxia tolerant traits, i.e., reduced glutathione, superoxide dismutase, and catalase, were also significantly (p < 0.05) induced in diplotype II than in diplotype I or III. In addition, the expression of epo in the liver of diplotype II was significantly (p < 0.01) higher than that in the diplotype I or III strains at 48 h of hypoxia. Taken together, our results found that the hypoxia-tolerant-related diplotype II of hif2αb has the potential to be used as a molecular marker in future genetic breeding of hypoxia-tolerant strain.
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Cui H, Liu Y, Zheng Y, Li H, Zhang M, Wang X, Zhao X, Cheng H, Xu J, Chen X, Ding Z. Intelectin enhances the phagocytosis of macrophages via CDC42-WASF2-ARPC2 signaling axis in Megalobrama amblycephala. Int J Biol Macromol 2023; 236:124027. [PMID: 36907302 DOI: 10.1016/j.ijbiomac.2023.124027] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 03/07/2023] [Accepted: 03/08/2023] [Indexed: 03/14/2023]
Abstract
Intelectin has been identified in various vertebrates and plays an important role in the host immune system. In our previous studies, recombinant Megalobrama amblycephala intelectin (rMaINTL) protein with excellent bacterial binding and agglutination activities enhances the phagocytic and killing activities of macrophages in M. amblycephala; however, the underlying regulatory mechanisms remain unclear. The present study showed that treatment with Aeromonas hydrophila and LPS induced the expression of rMaINTL in macrophages, and its level and distribution in macrophages or kidney tissue markedly increased after incubation or injection with rMaINTL. The cellular structure of macrophages was significantly affected after incubation with rMaINTL, resulting in an increased surface area and pseudopodia extension, which might contribute to enhancing the phagocytic ability of macrophages. Then, digital gene expression profiling analysis of the kidneys from rMaINTL-treated juvenile M. amblycephala identified some phagocytosis-related signaling factors that were enriched in pathways involved in the regulation of the actin cytoskeleton. In addition, qRT-PCR and western blotting verified that rMaINTL upregulated the expression of CDC42, WASF2, and ARPC2 in vitro and in vivo; however, the expression of these proteins was inhibited by a CDC42 inhibitor in macrophages. Moreover, CDC42 mediated the promotion of rMaINTL on actin polymerization by increasing the F-actin/G-actin ratio, which led to the extension of pseudopodia and remodeling of the macrophage cytoskeleton. Furthermore, the enhancement of macrophage phagocytosis by rMaINTL was blocked by the CDC42 inhibitor. These results suggested that rMaINTL induced the expression of CDC42 as well as the downstream signaling molecules WASF2 and ARPC2, thereby facilitating actin polymerization to promote cytoskeletal remodeling and phagocytosis. Overall, MaINTL enhanced the phagocytosis activity of macrophages in M. amblycephala via activation of the CDC42-WASF2-ARPC2 signaling axis.
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Jiang D, Li S, Liang Y, Ma J, Wang B, Zhang C. Protective effects of the fructooligosaccharide on the growth performance, biochemical indexes, and intestinal morphology of blunt snout bream ( Megalobrama amblycephala) infected by Aeromonas hydrophila. FISH PHYSIOLOGY AND BIOCHEMISTRY 2023; 49:139-153. [PMID: 36538149 DOI: 10.1007/s10695-022-01162-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 12/02/2022] [Indexed: 06/17/2023]
Abstract
The purpose of the study was to investigate the effects of dietary fructooligosaccharide (FOS) on growth performance, biochemical indexes, intestinal morphology, and growth-related gene expression of blunt snout bream (Megalobrama amblycephala) infected by Aeromonas hydrophila (AH). Two hundred twenty-five healthy blunt snout bream with an initial body weight of 38.41 ± 0.88 g were randomly divided into five groups with three replicates: control (basal diet), model (AH + basal diet), SFOS (AH + 2 g/kg FOS), MFOS (AH + 4 g/kg FOS), LFOS (AH + 6 g/kg FOS). After 9 weeks of feeding, the results showed that the FOS-added diet abrogated AH-induced retardation, hemorrhage, and inflammatory infiltration. FOS supplementation enhanced the growth performance degradation caused by AH, and the highest growth performance was observed at MFOS. Meanwhile, the addition of FOS to feed improved the blood immunity reduced by AH. In expansion, the mucosal epithelium of intestinal villi exfoliated, exposing the lamina propria, and a few villi were genuinely harmed in the model group. Fish fed with MFOS ameliorated the damaged intestine, evidenced by well-preserved intestine architecture. Furthermore, the model group downregulated the expression of growth-related genes (growth hormone receptor (GHR), insulin-like growth factor 1 (IGF-1)). Fish fed with 2 g/kg or 4 g/kg FOS upregulated the genes specified above expressions in the liver compared with the model group. In conclusion, the results mentioned above suggested that the dietary FOS could relieve the pressure to elevate the immune damage and intestine injury induced by AH and enhance the hepatic expression of IGF-1 and GHR.
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