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Zhao Q, Sun X, Zheng C, Xue C, Jin Y, Zhou N, Sun S. The evolutionarily conserved hif-1/bnip3 pathway promotes mitophagy and mitochondrial fission in crustacean testes during hypoxia. Am J Physiol Regul Integr Comp Physiol 2023; 324:R128-R142. [PMID: 36468826 DOI: 10.1152/ajpregu.00212.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The hypoxia-inducible factor 1 (HIF-1) cascade is an ancient and strongly evolutionarily conserved signaling pathway that is involved in the hypoxic responses of most metazoans. Despite immense advances in the understanding of the HIF-1-mediated regulation of hypoxic responses in mammals, the contribution of the hif-1 cascade in the hypoxic adaptation of nonmodel invertebrates remains unclear. In this study, we used the oriental river prawn Macrobrachium nipponense for investigating the roles of hif-1-regulated mitophagy in crustacean testes under hypoxic conditions. We identified that the Bcl-2/adenovirus E1B 19-kDa interacting protein (bnip3) functions as a regulator of mitophagy in M. nipponense and demonstrated that hif-1α activates bnip3 by binding to the bnip3 promoter. Hif-1α knockdown suppressed the expression of multiple mitophagy-related genes, and prawns with hif-1α knockdown exhibited higher mortality under hypoxic conditions. We observed that the levels of BNIP3 were induced under hypoxic conditions and detected that bnip3 knockdown inhibited the mitochondrial translocation of dynamin-related protein 1 (drp1), which is associated with mitochondrial fission. Notably, bnip3 knockdown inhibited hypoxia-induced mitophagy and aggravated the deleterious effects of hypoxia-induced reactive oxygen species (ROS) production and apoptosis. The experimental studies demonstrated that hypoxia induced mitochondrial fission in M. nipponense via drp1. Altogether, the study elucidated the mechanism underlying hif-1/bnip3-mediated mitochondrial fission and mitophagy and demonstrated that this pathway protects crustaceans against ROS production and apoptosis induced by acute hypoxia.
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Affiliation(s)
- Qianqian Zhao
- Key Laboratory of Freshwater Aquatic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai, People's Republic of China
| | - Xichao Sun
- Key Laboratory of Freshwater Aquatic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai, People's Republic of China
| | - Cheng Zheng
- Key Laboratory of Freshwater Aquatic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai, People's Republic of China
| | - Cheng Xue
- Key Laboratory of Freshwater Aquatic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai, People's Republic of China
| | - Yiting Jin
- Key Laboratory of Freshwater Aquatic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai, People's Republic of China
| | - Na Zhou
- State Key Laboratory of Quality Research in Chinese Medicine and School of Pharmacy, Macau University of Science and Technology, Macau, People's Republic of China
| | - Shengming Sun
- Key Laboratory of Freshwater Aquatic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai, People's Republic of China.,International Research Center for Marine Biosciences at Shanghai Ocean University, Ministry of Science and Technology, Shanghai, People's Republic of China
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Jin S, Hu Y, Fu H, Jiang S, Xiong Y, Qiao H, Zhang W, Gong Y, Wu Y. Identification and Characterization of the Pyruvate Dehydrogenase E1 Gene in the Oriental River Prawn, Macrobrachium nipponense. Front Endocrinol (Lausanne) 2021; 12:752501. [PMID: 34790171 PMCID: PMC8591192 DOI: 10.3389/fendo.2021.752501] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 09/16/2021] [Indexed: 11/23/2022] Open
Abstract
Pyruvate dehydrogenase E1 (PDHE1) is thought to play essential roles in energy metabolism, and a previous study suggested that it also has potential regulatory roles in male sexual development in the oriental river prawn, Macrobrachium nipponense. In this study, we used rapid amplification of cDNA ends, quantitative polymerase chain reaction (qPCR), in situ hybridization, western blotting, RNA interference (RNAi), and histological analyses to assess the potential functions of Mn-PDHE1 in the sexual development of male M. nipponense. The full cDNA sequence of Mn-PDHE1 was 1,614 base pairs long, including a 1,077 base pair open reading frame that encodes 358 amino acids. qPCR analysis revealed the regulatory functions of PDHE1 in male sexual development in M. nipponense and in the metamorphosis process. In situ hybridization and western blot results indicated that PDHE1 was involved in testis development, and RNAi analysis showed that PDHE1 positively regulated the expression of insulin-like androgenic gland factor in M. nipponense. Compared with the cell types in the testes of control prawns, histological analysis showed that the number of sperm was dramatically lower after test subjects were injected with Mn-PDHE1 dsRNA, whereas the numbers of spermatogonia and spermatocytes were higher. Sperm constituted only 1% of cells at 14 days after injection in the RNAi group. This indicated that knockdown of the expression of PDHE1 delayed testis development. Thus, PDHE1 has positive effects on male sexual development in M. nipponense. This study highlights the functions of PDHE1 in M. nipponense and its essential roles in the regulation of testis development.
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Affiliation(s)
- Shubo Jin
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Yuning Hu
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, China
| | - Hongtuo Fu
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, China
| | - Sufei Jiang
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Yiwei Xiong
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Hui Qiao
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Wenyi Zhang
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Yongsheng Gong
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Yan Wu
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
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Xu L, Fu Y, Fu H, Zhang W, Qiao H, Jiang S, Xiong Y, Jin S, Gong Y, Wang Y, Hu Y. Transcriptome analysis of hepatopancreas from different living states oriental river prawn (Macrobrachium nipponense) in response to hypoxia. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2021; 40:100902. [PMID: 34455149 DOI: 10.1016/j.cbd.2021.100902] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 08/12/2021] [Accepted: 08/16/2021] [Indexed: 12/12/2022]
Abstract
As an important economical freshwater prawn, Macrobrachium nipponense has difficulty with adapting to hypoxia. In this study, comparative transcriptome analysis was used for the first time to explore the differences between different living states of Macrobrachium nipponense under hypoxia. A total of 94.22 Gb clean reads were obtained and assembled into 54,688 unigenes. A total of 224, 266, and 750 differently expressed genes were found in the comparison of the control and death groups, the control and moribund groups, and the control and survived groups, respectively. Three signal pathways closely related to hypoxia were found by enriching of the signal pathways in three comparison groups. In addition, much attention was focused on the differential genes in these pathways. Oxidative stress related genes, such as 70 kDa heat shock protein, phosphoenolpyruvate carboxykinase and cyclooxygenase were differentially expressed in different comparisons. After comparing with previous studies, cyclooxygenase was found to be an important hypoxia-related gene that is fully involved in the hypoxic response. Interestingly, two new genes with no Nr annotation were found in this manuscript. This manuscript will enrich our understanding of oxidative stress response to hypoxia and provide a theoretical basis for the subsequent solution of apoptosis caused by hypoxia.
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Affiliation(s)
- Lei Xu
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, Jiangsu, China
| | - Yin Fu
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China
| | - Hongtuo Fu
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, Jiangsu, China; Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, Jiangsu, China.
| | - Wenyi Zhang
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, Jiangsu, China
| | - Hui Qiao
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, Jiangsu, China
| | - Sufei Jiang
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, Jiangsu, China
| | - Yiwei Xiong
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, Jiangsu, China
| | - Shubo Jin
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, Jiangsu, China
| | - Yongsheng Gong
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, Jiangsu, China
| | - Yabing Wang
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai 200090, China
| | - Yuning Hu
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, Jiangsu, China
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Jin S, Hu Y, Fu H, Jiang S, Xiong Y, Qiao H, Zhang W, Gong Y, Wu Y. Identification and Characterization of the Succinate Dehydrogenase Complex Iron Sulfur Subunit B Gene in the Oriental River Prawn, Macrobrachium nipponense. Front Genet 2021; 12:698318. [PMID: 34335695 PMCID: PMC8320353 DOI: 10.3389/fgene.2021.698318] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 05/24/2021] [Indexed: 11/13/2022] Open
Abstract
Previous studies have revealed that SDHB has potential functions in the male sexual differentiation and development in M. nipponense through providing ATP. In this study, the functions of Mn-SDHB were further analyzed in depth using quantitative polymerase chain reaction (qPCR), in situ hybridization, western-blot, and RNA interference (RNAi), combined with the histological observations. The full-genome sequence of Mn-SDHB was 54,608 bp at Chromosome 34, including 7 introns and 6 exons. The full-length cDNA sequence of Mn-SDHB was 1,268 base pairs (bp) long with an open reading frame of 807 bp, encoding for 268 amino acids. The highest expression level of Mn-SDHB in different tissues was observed in the testis, and male prawns at post-larval developmental stage 25 during different developmental stages, indicating that SDHB was potentially involved in the male sexual development in M. nipponense. In situ hybridization and western-blot analysis indicated that SDHB plays essential roles in the testis development. The in situ hybridization analysis also implies the potential roles of Mn-SDHB in ovarian development. The expressions of Mn-IAG were decreased after Mn-SDHB dsRNA injection, indicating SDHB has the positive regulatory effects on IAG in M. nipponese. Thus, SDHB was involved in the mechanism of the male sexual development. The testis development was inhibited, and sperms were rarely observed after 10 days of Mn-SDHB dsRNA injection, indicating SDHB has positive effects on the male sexual development in M. nipponense. This study highlights the functions of SDHB in M. nipponense, which provide new insights for the future studies of the male sexual development in other crustacean species.
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Affiliation(s)
- Shubo Jin
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Yuning Hu
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, China
| | - Hongtuo Fu
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China.,Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, China
| | - Sufei Jiang
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Yiwei Xiong
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Hui Qiao
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Wenyi Zhang
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Yongsheng Gong
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Yan Wu
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, China
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Sun S, Zhao Q, Xue C, Zheng C. Comparative Phosphoproteomics Reveals a Role for AMPK in Hypoxia Signaling in Testes of Oriental River Prawn ( Macrobrachium nipponense). J Proteome Res 2021; 20:2923-2934. [PMID: 33851848 DOI: 10.1021/acs.jproteome.1c00144] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Hypoxia is one of the major stresses in aquaculture animals. Recently, we reported that hypoxia disrupts the endocrine system and inhibits testicular function of oriental river prawns (Macrobrachium nipponense), but the molecular mechanism of testes responded to hypoxia remains largely unknown. In the present study, we aimed to integrate whole phosphoproteomic profiles of hypoxia-treated testes of the oriental river prawn (Macrobrachium nipponense). We successfully isolated sperm cells and evaluated the mitochondrial morphology and function using laser confocal microscopy, flow cytometry, and biochemical analyses. Quantitative proteomics identified 117 differentially abundant phosphorylated proteins, and these proteins are mainly involved in the pathways related to cellular processes, including autophagy, apoptosis, and the FoxO signaling pathway. Protein-protein interaction analysis clustered these phosphoproteins into three groups, many of which have been suggested to impact carbohydrate metabolism, autophagy, and signal regulation in testes. Western blotting confirmed that phosphorylated proteins including AMPK, ULK1, and TP53 (of the AMPK pathway) may contribute to testicular dysfunction caused by hypoxia. Further, we investigated the potential roles of AMP-activated protein kinase (AMPK)'s in testes mitochondrial autophagy and apoptosis in M. nipponense as induced by hypoxia. Simultaneous knockdown of AMPKα in sperm cells led to a decrease in FOXO3a phosphorylation at Ser413, upregulation of caspase-3 and caspase-9 activities, and an increased apoptosis rate. These results improve our understanding of hypoxia-induced energy metabolism disorders in the testes of M. nipponense.
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Affiliation(s)
- Shengming Sun
- Key Laboratory of Freshwater Aquatic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, PR China.,International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai 201306, China
| | - Qianqian Zhao
- Key Laboratory of Freshwater Aquatic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, PR China
| | - Cheng Xue
- Key Laboratory of Freshwater Aquatic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, PR China
| | - Cheng Zheng
- Key Laboratory of Freshwater Aquatic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai 201306, PR China
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Sun S, Wu Y, Fu H, Yang M, Ge X, Zhu J, Xuan F, Wu X. Evaluating expression of autophagy-related genes in oriental river prawn Macrobrachium nipponense as potential biomarkers for hypoxia exposure. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 171:484-492. [PMID: 30639875 DOI: 10.1016/j.ecoenv.2018.12.079] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 12/21/2018] [Accepted: 12/23/2018] [Indexed: 06/09/2023]
Abstract
Autophagy, a crucial process for maintaining cellular homeostasis, is under the control of several autophagy-related (ATG) proteins, and is highly conserved in most animals, but its response to adverse environmental conditions is poorly understood in crustaceans. Herein, we hypothesised that autophagy acts as a protective response to hypoxia, and Beclin 1, ATG7 and ATG8 in oriental river prawn (Macrobrachium nipponense) were chosen as potential biomarkers under hypoxia exposure; thus, their full-length cDNA sequences were cloned and characterised. Open reading frames (ORFs) of 1281, 2076 and 360 bp, encoding proteins of 427, 692 and 120 amino acid residues, respectively, were obtained. Phylogenetic analysis demonstrated the three M. nipponense proteins do not form a clade with vertebrate homologs. Protein and mRNA levels were investigated in different tissues and developmental stages, and all three were significantly upregulated in a time-dependent manner in the hepatopancreas following hypoxia stress. Biochemical and morphological analysis of hepatocytes revealed that hypoxia increased the abundance of hepatic autophagic vacuoles and stimulated anaerobic metabolism. RNA interference-mediated silencing of ATG8 significantly increased the death rate of M. nipponense juveniles under hypoxia stress conditions. Together, these results suggest that Beclin 1, ATG7 and ATG8 contribute to autophagy-based responses against hypoxia in M. nipponense. The findings also expand our understanding of the potential role of autophagy as an adaptive response against hypoxia toxicity in crustaceans. The results showed that hepatic ATG8 levels may be directly indicative of acute hypoxia in prawns, and provide insight into the time at which hypoxia exposure occurs. Autophagy-related genes expression pattern seems to be sensitive and good biomarkers of acute hypoxia exposure.
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Affiliation(s)
- Shengming Sun
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, PR China
| | - Ying Wu
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, PR China
| | - Hongtuo Fu
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, PR China; Key Laboratory of Genetic Breeding and Aquaculture Biology of Freshwater Fishes, Ministry of Agriculture, Freshwater Fisheries Research Centre, Chinese Academy of Fishery Sciences, Wuxi 214081, PR China.
| | - Ming Yang
- Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, PR China
| | - Xianping Ge
- Key Laboratory of Genetic Breeding and Aquaculture Biology of Freshwater Fishes, Ministry of Agriculture, Freshwater Fisheries Research Centre, Chinese Academy of Fishery Sciences, Wuxi 214081, PR China
| | - Jian Zhu
- Key Laboratory of Genetic Breeding and Aquaculture Biology of Freshwater Fishes, Ministry of Agriculture, Freshwater Fisheries Research Centre, Chinese Academy of Fishery Sciences, Wuxi 214081, PR China
| | - Fujun Xuan
- Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, Yancheng Teachers University, Yancheng 224051, PR China
| | - Xugan Wu
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Education, Shanghai 201306, PR China
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Sun S, Gu Z, Fu H, Zhu J, Ge X, Wu X. Hypoxia Induces Changes in AMP-Activated Protein Kinase Activity and Energy Metabolism in Muscle Tissue of the Oriental River Prawn Macrobrachium nipponense. Front Physiol 2018; 9:751. [PMID: 29962970 PMCID: PMC6011032 DOI: 10.3389/fphys.2018.00751] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 05/28/2018] [Indexed: 12/18/2022] Open
Abstract
Hypoxia has important effects on biological activity in crustaceans, and modulation of energy metabolism is a crucial aspect of crustaceans’ ability to respond to hypoxia. The adenosine 5′-monophosphate (AMP)-activated protein kinase (AMPK) enzyme is very important in cellular energy homeostasis; however, little information is known about the role of AMPK in the response of prawns to acute hypoxia. In the present study, three subunits of AMPK were cloned from the oriental river prawn, Macrobrachium nipponense. The full-length cDNAs of the α, β, and γ AMPK subunits were 1,837, 3,174, and 3,773 bp long, with open reading frames of 529, 289, and 961 amino acids, respectively. Primary amino acid sequence alignment of these three subunits revealed conserved similarity between the functional domains of the M. nipponense AMPK protein with AMPK proteins of other animals. The expression of the three AMPK subunits was higher in muscle tissue than in other tissues. Furthermore, the mRNA expression of AMPKα, AMPKβ, and AMPKγ were significantly up-regulated in M. nipponense muscle tissue after acute hypoxia. Probing with a phospho-AMPKα antibody revealed that AMPK is phosphorylated following hypoxia; this phosphorylation event was found to be essential for AMPK activation. Levels of glucose and lactic acid in hemolymph and muscle tissue were significantly changed over the course of hypoxia and recovery, indicating dynamic changes in energy metabolism in response to hypoxic stress. The activation of AMPK by hypoxic stress in M. nipponense was compared to levels of muscular AMP, ADP, and ATP, as determined by HPLC; it was found that activation of AMPK may not completely correlate with AMP:ATP ratios in prawns under hypoxic conditions. These findings confirm that the α, β, and γ subunits of the prawn AMPK protein are regulated at the transcriptional and protein levels during hypoxic stress to facilitate maintenance of energy homeostasis.
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Affiliation(s)
- Shengming Sun
- Key Laboratory of Genetic Breeding and Aquaculture Biology of Freshwater Fishes, Ministry of Agriculture, Freshwater Fisheries Research Centre, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Zhongbao Gu
- Guangxi Academy of Fishery Sciences, Nanning, China
| | - Hongtuo Fu
- Key Laboratory of Genetic Breeding and Aquaculture Biology of Freshwater Fishes, Ministry of Agriculture, Freshwater Fisheries Research Centre, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Jian Zhu
- Key Laboratory of Genetic Breeding and Aquaculture Biology of Freshwater Fishes, Ministry of Agriculture, Freshwater Fisheries Research Centre, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Xianping Ge
- Key Laboratory of Genetic Breeding and Aquaculture Biology of Freshwater Fishes, Ministry of Agriculture, Freshwater Fisheries Research Centre, Chinese Academy of Fishery Sciences, Wuxi, China
| | - Xugan Wu
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Education, Shanghai, China
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