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Li X, Liu C, Zhang R, Li Y, Ye D, Wang H, He M, Sun Y. Biosynthetic deficiency of docosahexaenoic acid causes nonalcoholic fatty liver disease and ferroptosis-mediated hepatocyte injury. J Biol Chem 2024; 300:107405. [PMID: 38788853 PMCID: PMC11231757 DOI: 10.1016/j.jbc.2024.107405] [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: 11/03/2023] [Revised: 05/07/2024] [Accepted: 05/08/2024] [Indexed: 05/26/2024] Open
Abstract
Exogenous omega-3 fatty acids, particularly docosahexaenoic acid (DHA), have shown to exert beneficial effects on nonalcoholic fatty liver disease (NAFLD), which is characterized by the excessive accumulation of lipids and chronic injury in the liver. However, the effect of endogenous DHA biosynthesis on the lipid homeostasis of liver is poorly understood. In this study, we used a DHA biosynthesis-deficient zebrafish model, elovl2 mutant, to explore the effect of endogenously biosynthesized DHA on hepatic lipid homeostasis. We found the pathways of lipogenesis and lipid uptake were strongly activated, while the pathways of lipid oxidation and lipid transport were inhibited in the liver of elovl2 mutants, leading to lipid droplet accumulation in the mutant hepatocytes and NAFLD. Furthermore, the elovl2 mutant hepatocytes exhibited disrupted mitochondrial structure and function, activated endoplasmic reticulum stress, and hepatic injury. We further unveiled that the hepatic cell death and injury was mainly mediated by ferroptosis, rather than apoptosis, in elovl2 mutants. Elevating DHA content in elovl2 mutants, either by the introduction of an omega-3 desaturase (fat1) transgene or by feeding with a DHA-rich diet, could strongly alleviate NAFLD features and ferroptosis-mediated hepatic injury. Together, our study elucidates the essential role of endogenous DHA biosynthesis in maintaining hepatic lipid homeostasis and liver health, highlighting that DHA deficiency can lead to NAFLD and ferroptosis-mediated hepatic injury.
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Affiliation(s)
- Xuehui Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Hubei Hongshan Laboratory, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Chengjie Liu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Hubei Hongshan Laboratory, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Ru Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Hubei Hongshan Laboratory, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yi Li
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Hubei Hongshan Laboratory, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Ding Ye
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Hubei Hongshan Laboratory, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Houpeng Wang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Hubei Hongshan Laboratory, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Mudan He
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Hubei Hongshan Laboratory, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Yonghua Sun
- State Key Laboratory of Freshwater Ecology and Biotechnology, Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Hubei Hongshan Laboratory, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China; College of Advanced Agricultural Sciences, University of Chinese Academy of Sciences, Beijing, China; The Innovation Academy of Seed Design, Chinese Academy of Sciences, Wuhan, China.
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2
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Zhang H, Li P, Zhu Y, Jiang Y, Feng J, Zhao Z, Xu J. Contribution of elovl5a to Docosahexaenoic Acid (DHA) Synthesis at the Transcriptional Regulation Level in Common Carp, Cyprinus carpio. Animals (Basel) 2024; 14:544. [PMID: 38396511 PMCID: PMC10886045 DOI: 10.3390/ani14040544] [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: 12/22/2023] [Revised: 01/29/2024] [Accepted: 02/01/2024] [Indexed: 02/25/2024] Open
Abstract
Docosahexaenoic acid (DHA) is an essential nutrient for humans and plays a critical role in human development and health. Freshwater fish, such as the common carp (Cyprinus carpio), have a certain degree of DHA biosynthesis ability and could be a supplemental source of human DHA needs. The elongase of very-long-chain fatty acid 5 (Elovl5) is an important enzyme affecting polyunsaturated fatty acid (PUFA) biosynthesis. However, the function and regulatory mechanism of the elovl5 gene related to DHA synthesis in freshwater fish is not clear yet. Previous studies have found that there are two copies of the elovl5 gene, elovl5a and elovl5b, which have different functions. Our research group found significant DHA content differences among individuals in Yellow River carp (Cyprinus carpio var.), and four candidate genes were found to be related to DHA synthesis through screening. In this study, the expression level of elovl5a is decreased in the high-DHA group compared to the low-DHA group, which indicated the down-regulation of elovl5a in the DHA synthesis pathways of Yellow River carp. In addition, using a dual-luciferase reporter gene assay, we found that by targeting the 3'UTR region of elovl5a, miR-26a-5p could regulate DHA synthesis in common carp. After CRISPR/Cas9 disruption of elovl5a, the DHA content in the disrupted group was significantly higher than in the wildtype group; meanwhile, the expression level of elovl5a in the disrupted group was significantly reduced compared with the wildtype group. These results suggest that elovl5a may be down-regulating DHA synthesis in Yellow River carp. This study could provide useful information for future research on the genes and pathways that affect DHA synthesis.
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Affiliation(s)
- Hanyuan Zhang
- Key Laboratory of Aquatic Genomics, Ministry of Agriculture and Rural Affairs, Beijing Key Laboratory of Fishery Biotechnology, Chinese Academy of Fishery Sciences, Beijing 100141, China; (P.L.); (Y.Z.); (Y.J.); (Z.Z.)
| | - Peizhen Li
- Key Laboratory of Aquatic Genomics, Ministry of Agriculture and Rural Affairs, Beijing Key Laboratory of Fishery Biotechnology, Chinese Academy of Fishery Sciences, Beijing 100141, China; (P.L.); (Y.Z.); (Y.J.); (Z.Z.)
| | - Youxiu Zhu
- Key Laboratory of Aquatic Genomics, Ministry of Agriculture and Rural Affairs, Beijing Key Laboratory of Fishery Biotechnology, Chinese Academy of Fishery Sciences, Beijing 100141, China; (P.L.); (Y.Z.); (Y.J.); (Z.Z.)
| | - Yanliang Jiang
- Key Laboratory of Aquatic Genomics, Ministry of Agriculture and Rural Affairs, Beijing Key Laboratory of Fishery Biotechnology, Chinese Academy of Fishery Sciences, Beijing 100141, China; (P.L.); (Y.Z.); (Y.J.); (Z.Z.)
| | - Jianxin Feng
- Henan Academy of Fishery Sciences, Zhengzhou 450044, China;
| | - Zixia Zhao
- Key Laboratory of Aquatic Genomics, Ministry of Agriculture and Rural Affairs, Beijing Key Laboratory of Fishery Biotechnology, Chinese Academy of Fishery Sciences, Beijing 100141, China; (P.L.); (Y.Z.); (Y.J.); (Z.Z.)
| | - Jian Xu
- Fisheries Engineering Institute, Chinese Academy of Fishery Sciences, Beijing 100141, China
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3
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Thompson WA, Rajeswari JJ, Holloway AC, Vijayan MM. Excess feeding increases adipogenesis but lowers leptin transcript abundance in zebrafish larvae. Comp Biochem Physiol C Toxicol Pharmacol 2024; 276:109816. [PMID: 38061616 DOI: 10.1016/j.cbpc.2023.109816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 11/26/2023] [Accepted: 12/04/2023] [Indexed: 12/17/2023]
Abstract
Although fish exposed to municipal wastewater effluents (MWWE) show higher lipid accumulation, whether this is due to adipogenesis is unclear. The objective here was to identify molecular markers of adipogenesis in zebrafish (Danio rerio) larvae for use as high throughput screening tools for environmental contaminants, including obesogens in MWWE. Zebrafish larvae were fed a commercial diet at a maintenance level (5 % body mass) or in excess (25 or 50 % body mass) from day 6 to 30 days post-fertilization (dpf) to stimulate adipogenesis. We monitored fat accumulation and markers of lipid metabolism, including peroxisome proliferator-activated receptor γ (ppar γ), fatty acid synthase (fas), ELOVL fatty acid elongase 2 (elovl2), diacylglycerol O-acyltransferase 2 (dgat2), leptin (lepa and lepb), leptin receptor (lepr), and lipoprotein lipase (lpl). Excess feeding led to a higher growth rate, protein content and an increase in igf1 transcript abundance. Also, these larvae had higher triglyceride levels and accumulated lipids droplets in the abdominal cavity and viscera. The molecular markers of adipogenesis, including fas, elovl2, and dgat2, were upregulated, while the transcript abundance of lpl, a lipolytic gene, was transiently lower due to excess feeding. The increased adiposity seen at 30 dpf due to excess feeding coincided with a lower lep but not lepr transcript abundance in zebrafish. Our results demonstrate that excess feeding alters the developmental programming of key genes involved in lipid homeostasis, leading to excess lipid accumulation in zebrafish larvae. Overall, fas, elovl2, lpl, and dgat2, but not lep or ppar γ, have the potential to be biomarkers of adipogenesis in zebrafish larvae.
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Affiliation(s)
- William Andrew Thompson
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada
| | - Jithine Jayakumar Rajeswari
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada
| | - Alison C Holloway
- Department of Obstetrics and Gynecology, McMaster University, 1280 Main St. West, Hamilton, ON L8S 4K1, Canada
| | - Mathilakath M Vijayan
- Department of Biological Sciences, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada.
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Coogan M, Xing D, Su B, Alston V, Johnson A, Khan M, Khalil K, Elaswad A, Li S, Wang J, Lu C, Wang W, Hettiarachchi D, Shang M, Hasin T, Qin Z, Cone R, Butts IAE, Dunham RA. CRISPR/Cas9-mediated knock-in of masu salmon (Oncorhyncus masou) elongase gene in the melanocortin-4 (mc4r) coding region of channel catfish (Ictalurus punctatus) genome. Transgenic Res 2023; 32:251-264. [PMID: 37468714 DOI: 10.1007/s11248-023-00346-w] [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: 07/08/2022] [Accepted: 03/24/2023] [Indexed: 07/21/2023]
Abstract
Channel catfish, Ictalurus punctatus, have limited ability to synthesize Ω-3 fatty acids. The ccβA-msElovl2 transgene containing masu salmon, Oncorhynchus masou, elongase gene driven by the common carp, Cyprinus carpio, β-actin promoter was inserted into the channel catfish melanocortin-4 receptor (mc4r) gene site using the two-hit two-oligo with plasmid (2H2OP) method. The best performing sgRNA resulted in a knockout mutation rate of 92%, a knock-in rate of 54% and a simultaneous knockout/knock-in rate of 49%. Fish containing both the ccβA-msElovl2 transgene knock-in and mc4r knockout (Elovl2) were 41.8% larger than controls at 6 months post-hatch (p = 0.005). Mean eicosapentaenoic acid (EPA, C20:5n-3) levels in Elov2 mutants and mc4r knockout mutants (MC4R) were 121.6% and 94.1% higher than in controls, respectively (p = 0.045; p = 0.025). Observed mean docosahexaenoic acid (DHA, C22:6n-3) and total EPA + DHA content was 32.8% and 45.1% higher, respectively, in Elovl2 transgenic channel catfish than controls (p = 0.368; p = 0.025). To our knowledge this is the first example of genome engineering to simultaneously target transgenesis and knock-out a gene in a commercially important aquaculture species for multiple improved performance traits. With a high transgene integration rate, improved growth, and higher omega-3 fatty acid content, the use of Elovl2 transgenic channel catfish appears beneficial for application on commercial farms.
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Affiliation(s)
- Michael Coogan
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA.
| | - De Xing
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Baofeng Su
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Veronica Alston
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Andrew Johnson
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Mohd Khan
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
- Department of Fisheries Biology and Genetics, Bangladesh Agricultural University, Mymensingh, 2202, Bangladesh
| | - Karim Khalil
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Ahmed Elaswad
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Shangjia Li
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Jinhai Wang
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Cuiyu Lu
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Wenwen Wang
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Darshika Hettiarachchi
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Mei Shang
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Tasnuba Hasin
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Zhenkui Qin
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Roger Cone
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Ian A E Butts
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Rex A Dunham
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
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Huang Y, Yang H, Li Y, Guo Y, Li G, Chen H. Comparative Transcriptome Analysis Reveals the Effect of Aurantiochytrium sp. on Gonadal Development in Zebrafish. Animals (Basel) 2023; 13:2482. [PMID: 37570291 PMCID: PMC10417364 DOI: 10.3390/ani13152482] [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: 06/19/2023] [Revised: 07/23/2023] [Accepted: 07/29/2023] [Indexed: 08/13/2023] Open
Abstract
Aurantiochytrium sp. has received much attention as a potential resource for mass production of omega-3 fatty acids, which contribute to improved growth and reproduction in aquatic animals. In this study, we evaluated the gonadal index changes in zebrafish supplemented with 1-3% Aurantiochytrium sp. crude extract (TE) and the effects of ex vivo environmental Aurantiochytrium sp. on oocytes. 1% TE group showed significant improvement in the gonadal index, and both in vitro incubation and intraperitoneal injection promoted the maturation of zebrafish oocytes. In contrast, the transcriptome revealed 576 genes that were differentially expressed between the 1% TE group and the control group, including 456 up-regulated genes and 120 down-regulated genes. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) pathway analysis of differentially expressed genes indicated that Aurantiochytrium sp. potentially affects pathways such as lipid metabolism, immune regulation, and oocyte development in zebrafish. The results of this study enriched the knowledge of Aurantiochytrium sp. in regulating gonadal development in zebrafish and provided a theoretical basis for its application in aquaculture.
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Affiliation(s)
- Yanlin Huang
- Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; (Y.H.); (H.Y.); (Y.L.); (Y.G.); (G.L.)
| | - Hao Yang
- Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; (Y.H.); (H.Y.); (Y.L.); (Y.G.); (G.L.)
| | - Yikai Li
- Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; (Y.H.); (H.Y.); (Y.L.); (Y.G.); (G.L.)
| | - Yuwen Guo
- Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; (Y.H.); (H.Y.); (Y.L.); (Y.G.); (G.L.)
| | - Guangli Li
- Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; (Y.H.); (H.Y.); (Y.L.); (Y.G.); (G.L.)
| | - Huapu Chen
- Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; (Y.H.); (H.Y.); (Y.L.); (Y.G.); (G.L.)
- Key Laboratory of Utilization and Conservation for Tropical Marine Bioresources of Ministry of Education, Hainan Key Laboratory for Conservation and Utilization of Tropical Marine Fishery Resources, Yazhou Bay Innovation Institute, Hainan Tropical Ocean University, Sanya 572022, China
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6
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Wu W, Ren T, Cao X, Gao J. Hepatic transcriptome analysis reveals that elovl5 deletion promotes PUFA biosynthesis and deposition. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART D, GENOMICS & PROTEOMICS 2023; 46:101076. [PMID: 37080058 DOI: 10.1016/j.cbd.2023.101076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 04/02/2023] [Accepted: 04/02/2023] [Indexed: 04/22/2023]
Abstract
The safe and low-cost acquisition of polyunsaturated fatty acids (PUFAs) has become a research hotspot. Fatty acyl elongase 5 (Elovl5), a rate-limiting enzyme for fatty acid elongation, is principally in charge of extending C18 and C20 PUFA substrates. However, the role of elovl5 in regulating pathways and genes involved in PUFA synthesis remain largely unknown. Here, hepatic transcriptome analysis of wild-type and elovl5 knockout (elovl5-/-) zebrafish was performed to identify the potential regulatory targets related to PUFA deposition and synthesis. There were 1579 differentially expressed genes (DEGs), of which 787 had their expression levels increased while 792 had the opposite effect. Peroxisome proliferators-activated receptors (PPAR) signaling pathway was considerably enriched in DEGs, according to the KEGG analysis, in which fatp2, fabp7, and pparδ were engaged in PUFA absorption and deposition. Additionally, transcriptome analysis also revealed that cyp46a1 and cyp2r1 were implicated in the synthesis of bile acids and the metabolism of vitamin D, thus indirectly participating in PUFA biosynthesis and deposition. Finally, the DEGs, which improve PUFA level following elovl5 deletion, were verified through feeding experiment with two prepared diets soybean oil diet and linolenic acid oil diet. This study revealed potential regulatory targets that improve PUFA level after elovl5 deletion in teleosts.
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Affiliation(s)
- Wenpeng Wu
- College of Fisheries, Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan 430070, China
| | - Tianying Ren
- College of Fisheries, Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan 430070, China
| | - Xiaojuan Cao
- College of Fisheries, Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan 430070, China; College of Fisheries, Hubei Provincial Engineering Laboratory for Pond Aquaculture, Huazhong Agricultural University, Wuhan 430070, China
| | - Jian Gao
- College of Fisheries, Engineering Research Center of Green development for Conventional Aquatic Biological Industry in the Yangtze River Economic Belt, Ministry of Education, Huazhong Agricultural University, Wuhan 430070, China; College of Fisheries, Hubei Provincial Engineering Laboratory for Pond Aquaculture, Huazhong Agricultural University, Wuhan 430070, China.
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7
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Genome-wide identification and expression profile of Elovl genes in threadfin fish Eleutheronema. Sci Rep 2023; 13:1080. [PMID: 36658196 PMCID: PMC9852283 DOI: 10.1038/s41598-023-28342-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 01/17/2023] [Indexed: 01/20/2023] Open
Abstract
Long-chain polyunsaturated fatty acids (LC-PUFA), including eicosapentaenoic acid and docosahexaenoic acid, are the essential fatty acids for organs to maintain various biological functions and processes. The threadfin fish Eleutheronema, with its rich nutritional value especially the high fatty acid contents, has become one of the promising aquaculture species in China and the potential food source of fatty acids for human consumption. However, the molecular basis underlying the biosynthesis of fatty acids in Eleutheronema species is still unknown. The elongation of the very long-chain fatty acids (Elovl) gene family in fish plays several critical roles in LC-PUFA synthesis. Therefore, in the present study, we performed genome-wide identification of the Elovl gene family to study their evolutionary relationships and expression profiles in two threadfin fish species Eleutheronema tetradactylum and Eleutheronema rhadinum, the first representatives from the family Eleutheronema. Phylogenetic analysis revealed that the Elovl genes in Eleutheronema were classified into six subfamilies (elovl1a/1b, elovl4a/4b, elovl5, elovl6/6 l, elovl7a, elovl8b). Phylogenetic, gene structure, motif, and conserved domain analysis indicated that the Elovl genes were highly conserved within the same subfamily in Eleutheronema. In addition, the Elovl genes were distributed in 7/26 chromosomes, while the duplicated gene pair, elovl4a and elovl4b, showed collinear relationships. The predicted secondary structure patterns and the 3D models revealed the highly similar functions and evolutionary conserved structure of Elovl proteins in Eleutheronema. The selection pressure analysis revealed that Elovl genes underwent strong purifying selection during evolution, suggesting that their functions might be evolutionarily conserved in Eleutheronema. Additionally, the expression patterns of Elovl genes in different tissues and species were distinct, indicating the possible functional divergence during evolution in the Eleutheronema genus. Collectively, we provided the first comprehensive genomic information on Elovl genes in threadfin fish Eleutheronema. This study enhanced the understanding of the underlying mechanisms of fatty acids biosynthesis in Eleutheronema, and provided new insights on breeding new varieties of fatty acids-enriched fish with potential benefits to farmers and the health of consumers.
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Li C, Wu Y, Li H, Wang H, Liu JX. Lipid-related metabolism during zebrafish embryogenesis under unbalanced copper homeostasis. FISH PHYSIOLOGY AND BIOCHEMISTRY 2022; 48:1571-1586. [PMID: 36161547 DOI: 10.1007/s10695-022-01127-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 09/17/2022] [Indexed: 05/13/2023]
Abstract
Copper (Cu) is an essential trace element, playing an important role in lipid metabolism, and its transporters ATP7A and ATP7B, as Cu-transporting P-type ATPases, are involved in maintaining the Cu homeostasis in cells. Numerous studies in mammals have shown that Cu homeostasis and lipid metabolism are closely related, but studies on the link between the effects of excess Cu, ATP7A, and ATP7B on lipid metabolism during vertebrate embryogenesis are scarce. In this study, zebrafish disease models with Cu overload and ATP7A and ATP7B inactivation, respectively, were used to study the lipid metabolism-related differentially expressed genes (DEGs) which were enriched in the models. The dynamic and spatiotemporal expressions of the DEGs in WTs, atp7a-/-, and atp7b-/- mutants with or without Cu stress were unveiled in this study and they mostly distributed in brain at 24 hpf then in liver and intestine at 96 hpf, suggesting their potential roles in lipid and glycogen metabolism to apply energy for normal development in zebrafish. Meanwhile, the correlation analysis for the DEGs among the three groups unveiled that most of the DEGs were involved in the glyceride metabolism pathway. This is the first report to establish the relationship between atp7a and atp7b with Cu-stimulated intestinal and liver lipid metabolism during fish embryogenesis, and this study will provide a theoretical basis for fish embryonic development and lipid metabolism disorders under unbalanced copper homeostasis.
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Affiliation(s)
- ChangShun Li
- College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 430070, China
| | - You Wu
- College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 430070, China
| | - HaoTian Li
- College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hai Wang
- Wuhan Zhihuiyuan Environmental Protection Technology, Co., Ltd, Wuhan, 430070, China
| | - Jing-Xia Liu
- College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Wuhan, 430070, China.
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Dominant Elongase Activity of Elovl5a but Higher Expression of Elovl5b in Common Carp ( Cyprinus carpio). Int J Mol Sci 2022; 23:ijms232314666. [PMID: 36498993 PMCID: PMC9741273 DOI: 10.3390/ijms232314666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/01/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022] Open
Abstract
Most diploid freshwater and marine fish encode one elovl5 elongase, having substrate specificity and activities towards C18, C20 and C22 polyunsaturated fatty acids (PUFAs). The allo-tetraploid common carp is hypothesized to encode two duplicated elovl5 genes. How these two elovl5 genes adapt to coordinate the PUFA biosynthesis through elongase function and expression divergence requires elucidation. In this study, we obtained the full-length cDNA sequences of two elovl5 genes in common carp, named as elovl5a and elovl5b. Functional characterization showed that both enzymes had elongase activity towards C18, C20 and C22 PUFAs. Especially, the activities of these two enzymes towards C22 PUFAs ranged from 3.87% to 8.24%, higher than those in most freshwater and marine fish. The Elovl5a had higher elongase activities than Elovl5b towards seven substrates. The spatial-temporal expression showed that both genes co-transcribed in all tissues and development stages. However, the expression levels of elovl5b were significantly higher than those of elovl5a in all examined conditions, suggesting that elovl5b would be the dominantly expressed gene. These two genes had different potential transcriptional binding sites. These results revealed the complicated roles of elovl5 on PUFA synthesis in common carp. The data also increased the knowledge of co-ordination between two homoeologs of the polyploid fish through function and expression divergence.
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The repertoire of the elongation of very long-chain fatty acids (Elovl) protein family is conserved in tambaqui (Colossoma macropomum): Gene expression profiles offer insights into the sexual differentiation process. Comp Biochem Physiol B Biochem Mol Biol 2022; 261:110749. [PMID: 35470007 DOI: 10.1016/j.cbpb.2022.110749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 04/18/2022] [Accepted: 04/19/2022] [Indexed: 11/24/2022]
Abstract
Elongation of very long-chain fatty acids (Elovl) proteins are critical players in the regulation of the length of a fatty acid. At present, eight members of the Elovl family (Elovl1-8), displaying a characteristic fatty acid substrate specificity, have been identified in vertebrates, including teleost fish. In general, Elovl1, Elovl3, Elovl6 and Elovl7 exhibit a substrate preference for saturated and monounsaturated fatty acids, while Elovl2, Elovl4, Elovl5 and Elovl8 use polyunsaturated fatty acids (PUFA) as substrates. PUFA elongases have received considerable attention in aquatic animals due to their involvement in the conversion of C18 PUFAs to long-chain polyunsaturated fatty acids (LC-PUFA). Here, we identified the full repertoire of elovl genes in the tambaqui Colossoma macropomum genome. A detailed phylogenetic and synteny analysis suggests a conservation of these genes among teleosts. Furthermore, based on RNAseq gene expression data, we discovered a gender bias expression of elovl genes during sex differentiation of tambaqui, toward future males. Our findings suggest a role of Elovl enzymes and fatty acid metabolism in tambaqui sexual differentiation.
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Xing D, Su B, Li S, Bangs M, Creamer D, Coogan M, Wang J, Simora R, Ma X, Hettiarachchi D, Alston V, Wang W, Johnson A, Lu C, Hasin T, Qin Z, Dunham R. CRISPR/Cas9-Mediated Transgenesis of the Masu Salmon (Oncorhynchus masou) elovl2 Gene Improves n-3 Fatty Acid Content in Channel Catfish (Ictalurus punctatus). MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2022; 24:513-523. [PMID: 35416602 DOI: 10.1007/s10126-022-10110-6] [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: 10/17/2021] [Accepted: 03/02/2022] [Indexed: 06/14/2023]
Abstract
Omega-3 polyunsaturated fatty acids (n-3 PUFAs), particularly eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3), play a very important role in human health. Channel catfish (Ictalurus punctatus) is one of the leading freshwater aquaculture species in the USA, but has low levels of EPA and DHA compared to some fish such as salmon. To improve EPA and DHA content, a modification of the n-3 PUFA biosynthetic pathway was achieved through the insertion of an elovl2 transgene isolated from masu salmon (Oncorhynchus masou) driven by a carp β-actin promoter using a two-hit by gRNA and two oligos with a targeting plasmid (2H2OP) CRISPR/Cas9 approach. Integration rate of the transgene was high (37.5%) and detected in twelve different tissues of P1 transgenic fish with tissue-specific gene expression. Liver and muscle had relative high gene expression (13.4- and 9.2-fold change, respectively). Fatty acid analysis showed DHA content in the muscle from transgenic fish was 1.62-fold higher than in non-transgenic fish (P < 0.05). Additionally, total n-3 PUFAs and omega-6 polyunsaturated fatty acids (n-6 PUFAs) increased to 1.41-fold and 1.50-fold, respectively, suggesting the β-actin-elovl2 transgene improved biosynthesis of PUFAs in channel catfish as a whole. The n-9 fatty acid level decreased in the transgenic fish compared to the control. Morphometric analysis showed that there were significant differences between injected fish with sgRNAs (including positive and negative fish) and sham-injected controls (P < 0.001). Potential off-target effects are likely the major factor responsible for morphological deformities. Optimization of sgRNA design to maximize activity and reduce off-target effects of CRISPR/Cas9 should be examined in future transgenic research, but this research shows a promising first step in the improvement of n-3 PUFAs in channel catfish.
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Affiliation(s)
- De Xing
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Baofeng Su
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Shangjia Li
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Max Bangs
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
- Department of Biological Science, Florida State University, Tallahassee, FL, 32304, USA
| | - David Creamer
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Michael Coogan
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Jinhai Wang
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Rhoda Simora
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
- College of Fisheries and Ocean Sciences, University of the Philippines Visayas, 5023, Miagao, Iloilo, Philippines
| | - Xiaoli Ma
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Darshika Hettiarachchi
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Veronica Alston
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Wenwen Wang
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Andrew Johnson
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Cuiyu Lu
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Tasnuba Hasin
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Zhenkui Qin
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA.
- Ministry of Education Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, Qingdao, 266003, China.
| | - Rex Dunham
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA.
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Zou Y, Zhou Z, Yin S, Huang C, Tang H, Yin Z. Targeting of gallbladder megalin receptors with DHA-conjugated limonene albumin nanoparticles. NANOSCALE 2022; 14:6052-6065. [PMID: 35380143 DOI: 10.1039/d1nr07767h] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Gallbladder stones are a major pathogenic factor leading to cholecystitis, and it is increasingly important to explore innovative drug delivery methods for gallstones. In the present study, docosahexaenoic acid-coupled limonene bovine serum albumin nanoparticles (LIM-DHA-BSA-NPs) were constructed. The LIM-DHA-BSA-NPs are spherical structures, and the distribution was relatively uniform, and, more importantly, it has low cytotoxicity and good safety. The LIM-DHA-BSA-NPs solution shows higher uptake rates by RAW264.7 cells when compared with free limonene (LIM). The fluorescence intensity of FITC-modified BSA NPs was significantly higher than that of free FITC, which further indicated that the uptake of DHA-conjugated BSA NPs by RAW264.7 cells was stronger than that of the free drugs. Moreover, the in vivo distribution experiment showed that the enrichment of DiD-loaded BSA NPs in the gallbladder was significantly enhanced when compared with that of free DiD. The semi-quantitative fluorescence intensity results showed that the uptake of DiD-DHA-BSA-NPs was 4.5 times higher when compared with the free DiD. It is preliminarily shown that the DHA-conjugated BSA NPs that were constructed, have an ability to target the gallbladder. Furthermore, the Pearson colocalization coefficient Rcoloc from in vivo colocalization results indicates that the DHA-BSA-NPs had a good colocalization effect on the gallbladder epithelial cells (GBECs). In addition, the LIM-DHA-BSA-NPs solution not only significantly reduced the concentration of nitric oxide (NO) secreted by inflammatory model cells and the number of peripheral blood leukocytes in guinea pigs with cholecystitis, but also significantly decreased the activities of the aspartate transaminase (AST), alkaline phosphatase (ALP), alanine aminotransferase (ALT), glutamyl endopeptidase (GGT), total bile acid (TBA), and total bilirubin (TBIL) enzymes. Collectively, the LIM-DHA-BSA-NPs could be used as an effective anti-inflammatory agent at the cellular and animal levels. This experiment, for the first time, showed that DHA-conjugated BSA NPs could be absorbed into GBECs by megalin receptor-mediated endocytosis and then they exert an anti-cholecystitis effect because of the LIM. The active uptake of DHA-conjugated BSA NPs by the megalin receptors of the GBECs is expected to become an effective therapeutic strategy for cholecystolithiasis.
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Affiliation(s)
- Ya Zou
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
| | - Zishuo Zhou
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
| | - Shanmei Yin
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
| | - Chengyuan Huang
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
| | - Hesong Tang
- Sichuan Emeishan Pharmaceutical Co., Ltd, No.6 Yingbin Road, High-tech Development Zone, Leshan City, Sichuan Province, 614000, China
| | - Zongning Yin
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
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Monroig Ó, Shu-Chien A, Kabeya N, Tocher D, Castro L. Desaturases and elongases involved in long-chain polyunsaturated fatty acid biosynthesis in aquatic animals: From genes to functions. Prog Lipid Res 2022; 86:101157. [DOI: 10.1016/j.plipres.2022.101157] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 12/17/2021] [Accepted: 01/22/2022] [Indexed: 01/01/2023]
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14
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Chen Z, Cao X, Lu Q, Zhou J, Wang Y, Wu Y, Mao Y, Xu H, Yang Z. circ01592 regulates unsaturated fatty acid metabolism through adsorbing miR-218 in bovine mammary epithelial cells. Food Funct 2021; 12:12047-12058. [PMID: 34761771 DOI: 10.1039/d1fo02797b] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The composition of fatty acids plays a key role in regulating milk flavor and quality. Therefore, to improve the quality of milk, it is particularly important to study the regulatory mechanism of fatty acid metabolism in dairy cows. In this study, the expression profiles at non-lactation, peak-lactation, mid-lactation and late-lactation were constructed by high-throughput sequencing. Considering non-lactation as the control group and the other points as the experimental groups, the differentially expressed genes were screened. ELOVL5 was significantly upregulated and was selected for subsequent analyses. Bioinformatics prediction, a dual-luciferase assay, qPCR analysis and western blot analysis were used for verification. The results showed that ELOVL5 was a downstream target gene of miR-218 that regulated milk fat metabolism. A dual-luciferase assay and expression level analysis showed that circ01592 can directly bind to miR-218 and that overexpression of circ01592 (pcDNA-circ01592) significantly reduced the expression of miR-218 and enhanced the expression of ELOVL5, the target gene of miR-218 in BMECs. A functional study of BMECs showed that circ01592 promoted the synthesis of TAG and increased the content of UFA. The function of miR-218 was opposite to that of circ01592. Overall, the data showed that circ01592 promoted TAG synthesis and fatty acid composition by binding miR-218, alleviating the inhibitory effect of miR-218 on ELOVL5 expression. These mechanisms provide a new research approach and theoretical basis for improving milk quality.
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Affiliation(s)
- Zhi Chen
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, P. R. China. .,Joint International Research Laboratory of Agriculture & Agri-Product Safety, Ministry of Education, Yangzhou University, Yangzhou, China
| | - Xiang Cao
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, P. R. China. .,Joint International Research Laboratory of Agriculture & Agri-Product Safety, Ministry of Education, Yangzhou University, Yangzhou, China
| | - Qinyue Lu
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, P. R. China. .,Joint International Research Laboratory of Agriculture & Agri-Product Safety, Ministry of Education, Yangzhou University, Yangzhou, China
| | - Jingpeng Zhou
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, P. R. China. .,Joint International Research Laboratory of Agriculture & Agri-Product Safety, Ministry of Education, Yangzhou University, Yangzhou, China
| | - Yuhao Wang
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, P. R. China. .,Joint International Research Laboratory of Agriculture & Agri-Product Safety, Ministry of Education, Yangzhou University, Yangzhou, China
| | - Yanni Wu
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, P. R. China. .,Joint International Research Laboratory of Agriculture & Agri-Product Safety, Ministry of Education, Yangzhou University, Yangzhou, China
| | - Yongjiang Mao
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, P. R. China. .,Joint International Research Laboratory of Agriculture & Agri-Product Safety, Ministry of Education, Yangzhou University, Yangzhou, China
| | - Huifen Xu
- College of Animal Science and Veterinary Medicine, Henan Agricultural University, Zhengzhou, Henan, China
| | - Zhangping Yang
- College of Animal Science and Technology, Yangzhou University, Yangzhou 225009, P. R. China. .,Joint International Research Laboratory of Agriculture & Agri-Product Safety, Ministry of Education, Yangzhou University, Yangzhou, China
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15
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Evolution and Functional Characteristics of the Novel elovl8 That Play Pivotal Roles in Fatty Acid Biosynthesis. Genes (Basel) 2021; 12:genes12081287. [PMID: 34440461 PMCID: PMC8392482 DOI: 10.3390/genes12081287] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/15/2021] [Accepted: 08/18/2021] [Indexed: 12/20/2022] Open
Abstract
Elongation of very long-chain fatty acid (Elovl) proteins are key enzymes that catalyze the rate-limiting step in the fatty acid elongation pathway. The most recently discovered member of the Elovl family, Elovl8, has been proposed to be a fish-specific elongase with two gene paralogs described in teleosts. However, the biological functions of Elovl8 are still to be elucidated. In this study, we showed that in contrast to previous findings, elovl8 is not unique to teleosts, but displays a rather unique and ample phylogenetic distribution. For functional determination, we generated elovl8a (elovl8a−/−) and elovl8b (elovl8b−/−) zebrafish using CRISPR/Cas9 technology. Fatty acid composition in vivo and zebrafish liver cell experiments suggest that the substrate preference of Elovl8 overlapped with other existing Elovl enzymes. Zebrafish Elovl8a could elongate the polyunsaturated fatty acids (PUFAs) C18:2n-6 and C18:3n-3 to C20:2n-6 and C20:3n-3, respectively. Along with PUFA, zebrafish Elovl8b also showed the capacity to elongate C18:0 and C20:1. Gene expression quantification suggests that Elovl8a and Elovl8b may play a potentially important role in fatty acid biosynthesis. Overall, our results provide novel insights into the function of Elovl8a and Elovl8b, representing additional fatty acid elongases not previously described in chordates.
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Nyunoya H, Noda T, Kawamoto Y, Hayashi Y, Ishibashi Y, Ito M, Okino N. Lack of ∆5 Desaturase Activity Impairs EPA and DHA Synthesis in Fish Cells from Red Sea Bream and Japanese Flounder. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2021; 23:472-481. [PMID: 34176006 DOI: 10.1007/s10126-021-10040-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 05/28/2021] [Indexed: 06/13/2023]
Abstract
Long-chain (≥ C20) polyunsaturated fatty acids (LC-PUFA), such as eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA), are necessary for human health and are obtained from marine fish-derived oils. Marine fish are LC-PUFA-rich animals; however, many of them require LC-PUFA for growth. Therefore, it is suggested that they do not have sufficient ability to biosynthesize LC-PUFA. To evaluate in vivo LC-PUFA synthetic activity in fish cells, fish-derived cell lines from red sea bream (Pagrus major, PMS and PMF), Japanese flounder (Paralichthys olivaceus, HINAE), and zebrafish (Danio rerio, BRF41) were incubated with n-3 fatty acids labeled by radioisotopes or stable isotopes, and then, n-3 PUFA were analyzed by thin-layer chromatography or liquid chromatography-mass spectrometry. Labeled EPA and DHA were biosynthesized from labeled α-linolenic acid (18:3n-3) in BRF41, whereas they were not detected in PMS, PMF, or HINAE cells. We next cloned the fatty acid desaturase 2 (Fads2) cDNAs from PMF cells and zebrafish, expressed in budding yeasts, and then analyzed the substrate specificities of enzymes. As a result, we found that Fads2 from PMF cells was a ∆6/∆8 desaturase. Collectively, our study indicates that cell lines from red sea bream and Japanese flounder were not able to synthesize EPA or DHA by themselves, possibly due to the lack of ∆5 desaturase activity. Furthermore, this study provides a sensitive and reproducible non-radioactive method for evaluating LC-PUFA synthesis in fish cells using a stable isotope and liquid chromatography-mass spectrometry.
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Affiliation(s)
- Hayato Nyunoya
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Tatsuki Noda
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - You Kawamoto
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Yasuhiro Hayashi
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka, 819-0395, Japan
- Faculty of Pharma-Science, Teikyo University, Kaga 2-11-1, Itabashi-ku, Tokyo, 173-8605, Japan
| | - Yohei Ishibashi
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Makoto Ito
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Nozomu Okino
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka, 819-0395, Japan.
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ADIPOR1 deficiency-induced suppression of retinal ELOVL2 and docosahexaenoic acid levels during photoreceptor degeneration and visual loss. Cell Death Dis 2021; 12:458. [PMID: 33963174 PMCID: PMC8105316 DOI: 10.1038/s41419-021-03741-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 03/23/2021] [Accepted: 03/25/2021] [Indexed: 02/03/2023]
Abstract
Lipid metabolism-related gene mutations can cause retinitis pigmentosa, a currently untreatable blinding disease resulting from progressive neurodegeneration of the retina. Here, we demonstrated the influence of adiponectin receptor 1 (ADIPOR1) deficiency in retinal neurodegeneration using Adipor1 knockout (KO) mice. Adipor1 mRNA was observed to be expressed in photoreceptors, predominately within the photoreceptor inner segment (PIS), and increased after birth during the development of the photoreceptor outer segments (POSs) where photons are received by the visual pigment, rhodopsin. At 3 weeks of age, visual function impairment, specifically photoreceptor dysfunction, as recorded by electroretinography (ERG), was evident in homozygous, but not heterozygous, Adipor1 KO mice. However, although photoreceptor loss was evident at 3 weeks of age and progressed until 10 weeks, the level of visual dysfunction was already substantial by 3 weeks, after which it was retained until 10 weeks of age. The rhodopsin mRNA levels had already decreased at 3 weeks, suggesting that reduced rhodopsin may have contributed to early visual loss. Moreover, inflammation and oxidative stress were induced in homozygous KO retinas. Prior to observation of photoreceptor loss via optical microscopy, electron microscopy revealed that POSs were present; however, they were misaligned and their lipid composition, including docosahexaenoic acid (DHA), which is critical in forming POSs, was impaired in the retina. Importantly, the expression of Elovl2, an elongase of very long chain fatty acids expressed in the PIS, was significantly reduced, and lipogenic genes, which are induced under conditions of reduced endogenous DHA synthesis, were increased in homozygous KO mice. The causal relationship between ADIPOR1 deficiency and Elovl2 repression, together with upregulation of lipogenic genes, was confirmed in vitro. Therefore, ADIPOR1 in the retina appears to be indispensable for ELOVL2 induction, which is likely required to supply sufficient DHA for appropriate photoreceptor function and survival.
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Elovl2 Is Required for Robust Visual Function in Zebrafish. Cells 2020; 9:cells9122583. [PMID: 33276584 PMCID: PMC7761535 DOI: 10.3390/cells9122583] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 11/12/2020] [Accepted: 11/29/2020] [Indexed: 12/11/2022] Open
Abstract
Omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) play critical roles in membrane stability and cell signaling within the retina. ELOVL2 (Elongation of Very Long Chain Fatty Acids-Like 2), an elongase involved in the synthesis of long chain polyunsaturated fatty acids (LC-PUFAs), has recently been implicated in regulating aging in the mammalian retina. In this work, we characterize the expression and function of elovl2 in the retina development in embryonic zebrafish. Whole mount in situ hybridization shows elovl2 is expressed in the Muller glia in embryonic and adult zebrafish. Lipidomics analysis of elovl2 crispants whole embryos at day 2 and eyes at day 7 demonstrated significant changes in lipids composition, especially on the level of lipids containing docosahexaenoic acid (DHA). Histological analysis of zebrafish lacking elovl2 revealed increased retinal thickness compared to controls at day 7 without gross disruptions of the retinal architecture. Finally, elovl2 crispants showed differences in the visual motor reflex light off (VMR-OFF) at day 7 compared to controls. In sum, inactivation of elovl2 in zebrafish embryos caused changes in lipid composition and in visual behavior, further confirming the important role of LC-PUFAs in healthy vision.
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