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Chiu HW, Hung SW, Chiu CF, Hong JR. A Mitochondrion-Targeting Protein (B2) Primes ROS/Nrf2-Mediated Stress Signals, Triggering Apoptosis and Necroptosis in Lung Cancer. Biomedicines 2023; 11:biomedicines11010186. [PMID: 36672696 PMCID: PMC9855812 DOI: 10.3390/biomedicines11010186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 01/03/2023] [Accepted: 01/09/2023] [Indexed: 01/15/2023] Open
Abstract
The betanodavirus B2 protein targets mitochondria and triggers mitochondrion-mediated cell death signaling in lung cancer cells; however, its molecular mechanism remains unknown. In this study, we observed that B2 triggers hydrogen peroxide/Nrf2-involved stress signals in the dynamic regulation of non-small lung cancer cell (NSCLC)-programmed cell death. Here, the B2 protein works as a necrotic inducer that triggers lung cancer death via p53 upregulation and RIP3 expression, suggesting a new perspective on lung cancer therapy. We employed the B2 protein to target A549 lung cancer cells and solid tumors in NOD/SCID mice. Tumors were collected and processed for the hematoxylin and eosin staining of tissue and cell sections, and their sera were used for blood biochemistry analysis. We observed that B2 killed an A549 cell-induced solid tumor in NOD/SCID mice; however, the mutant ΔB2 did not. In NOD/SCID mice, B2 (but not ΔB2) induced both p53/Bax-mediated apoptosis and RIPK3-mediated necroptosis. Finally, immunochemistry analysis showed hydrogen peroxide /p38/Nrf2 stress strongly inhibited the production of tumor markers CD133, Thy1, and napsin, which correlate with migration and invasion in cancer cells. This B2-triggered, ROS/Nrf2-mediated stress signal triggered multiple signals via pathways that killed A549 lung cancer tumor cells in vivo. Our results provide novel insight into lung cancer management and drug therapy.
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Affiliation(s)
- Hsuan-Wen Chiu
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
- Department of Biotechnology and Bioindustry, National Cheng Kung University, Tainan 701, Taiwan
| | - Shao-Wen Hung
- Division of Animal Industry, Animal Technology Research Center, Agricultural Technology Research Institute, Hsinchu 300, Taiwan
| | - Ching-Feng Chiu
- Graduate Institute of Metabolism and Obesity Sciences, College of Nutrition, Taipei Medical University, Taipei 11031, Taiwan
- Graduate TMU Research Center of Cancer Translational Medicine, Taipei Medical University, Taipei 11031, Taiwan
| | - Jiann-Ruey Hong
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
- Department of Biotechnology and Bioindustry, National Cheng Kung University, Tainan 701, Taiwan
- Correspondence: ; Tel.: +886-6-2003082; Fax: +886-6-2766505
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Chen PH, Hsueh TC, Hong JR. Infectious spleen and kidney necrosis virus induces the reactive oxidative species/Nrf2-mediated oxidative stress response for the regulation of mitochondrion-mediated Bax/Bak cell death signals in GF-1 cells. Front Microbiol 2022; 13:958476. [PMID: 36304944 PMCID: PMC9593061 DOI: 10.3389/fmicb.2022.958476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 09/21/2022] [Indexed: 11/13/2022] Open
Abstract
Infectious spleen and kidney necrosis virus (ISKNV) infections can trigger host cell death and are correlated with viral replication; however, they have rarely been considered in terms of the host organelle involvement. In the present study, we demonstrated that ISKNV triggered an oxidative stress signal in the Nrf2-mediated oxidative stress response and induced stress signals for Bax/Bak-mediated host cell death in fish GF-1 cells. The results showed that after ISKNV infection, the levels of reactive oxidative species (ROS) increased by 60–80% from day 3 to day 5, as assessed by an H2DCFDA assay for tracing hydrogen peroxide (H2O2), which was correlated with up to a one-fold change in the fish GF-1 cells. Furthermore, we found that ISKNV infection induced Nrf2-mediated ROS stress signals from D1 to D5, which were correlated with the upregulation of antioxidant enzymes, such as catalase, SOD1, and SOD2; these effects were blocked by the antioxidants GSH and NAC. By analyzing Nrf2-mediated ROS stress signals for cell death regulation via an apoptotic assay, we found that treatment with antioxidants reduced annexin-V-positive signals by 10% (GSH) to 15% (NAC); moreover, necrotic-positive signals were reduced by 6% (GSH) and 32% (NAC) at day 5 (D5) in GF-1 cells, as indicated by PI staining. Furthermore, we found that Nrf2-mediated ROS stress regulated mitochondrion-mediated Bax/Bak death signals at D3 and D5; this was effectively blocked by antioxidant treatment in the GF-1 cells, as demonstrated by a JC1 assay (ΔΨm) and western blot analysis. In addition, we found that downstream signals for caspase-9 and -3 activation were apparently blocked by antioxidant treatment at D3 and D5. Finally, we found that treatment with GSH and NAC reduced major capsid protein (MCP) expression and virus titer (TCID50%) by up to 15-fold at D5 in GF-1 cells. Thus, our data suggest that ISKNV can induce ROS production, which triggers Nrf2-mediated stress signals. Then, these stress signals can regulate mitochondrion-mediated Bax/Bak apoptotic signaling, which is connected to downstream caspase-9 and -3 activation. If ISKNV-induced Nrf2-mediated stress signaling is blocked, then the antioxidants GSH and NAC can also suppress apoptotic signals or reduce viral replication. These findings may provide insights into the control and treatment of double-stranded DNA viruses.
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Affiliation(s)
- Pin-Han Chen
- Lab of Molecular Virology and Biotechnology, Department of Biotechnology and Bioindustry Sciences, Institute of Biotechnology, National Cheng Kung University, Tainan City, Taiwan
- Institute of Biotechnology, National Cheng Kung University, Tainan City, Taiwan
| | - Tsai-Ching Hsueh
- Lab of Molecular Virology and Biotechnology, Department of Biotechnology and Bioindustry Sciences, Institute of Biotechnology, National Cheng Kung University, Tainan City, Taiwan
- Institute of Biotechnology, National Cheng Kung University, Tainan City, Taiwan
| | - Jiann-Ruey Hong
- Lab of Molecular Virology and Biotechnology, Department of Biotechnology and Bioindustry Sciences, Institute of Biotechnology, National Cheng Kung University, Tainan City, Taiwan
- Institute of Biotechnology, National Cheng Kung University, Tainan City, Taiwan
- *Correspondence: Jiann-Ruey Hong,
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Reshi L, Wang HV, Hui CF, Su YC, Hong JR. Corrigendum to "Anti-apoptotic genes Bcl-2 and Bcl-xL overexpression can block iridovirus serine/threonine kinase-induced Bax/mitochondria-mediated cell death in GF-1 cells" [Fish Shellfish Immunol. 61 (2017) 120-129]. Fish Shellfish Immunol 2022; 122:501. [PMID: 35177309 DOI: 10.1016/j.fsi.2022.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Affiliation(s)
- Latif Reshi
- Lab of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, No. 1 University Road, Tainan City, 701, Taiwan, ROC; Department of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, No. 1 University Road, Tainan City, 701, Taiwan, ROC
| | - Hao-Ven Wang
- Department of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, No. 1 University Road, Tainan City, 701, Taiwan, ROC
| | - Cho-Fat Hui
- Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, 115, Taiwan, ROC
| | - Yu-Chin Su
- Lab of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, No. 1 University Road, Tainan City, 701, Taiwan, ROC
| | - Jiann-Ruey Hong
- Lab of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, No. 1 University Road, Tainan City, 701, Taiwan, ROC; Department of Biotechnology and Bioindustry, National Cheng Kung University, No. 1 University Road, Tainan City, 701, Taiwan, ROC.
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Hung JC, Wu JL, Li HC, Chiu HW, Hong JR. The Proapoptotic Gene Bad Regulates Brain Development via p53-Mediated Stress Signals in Zebrafish. Cells 2021; 10:cells10112820. [PMID: 34831043 PMCID: PMC8616466 DOI: 10.3390/cells10112820] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/15/2021] [Accepted: 10/16/2021] [Indexed: 01/01/2023] Open
Abstract
Studies have shown that the BH3-only domain Bad regulates brain development via the control of programmed cell death (PCD), but very few studies have addressed its effect on the molecular signaling of brain development in the system. In this work, we examined the novel role of zebrafish Bad in initial programmed cell death for brain morphogenesis through the priming of p53-mediated stress signaling. In a biological function study on the knockdown of Bad by morpholino oligonucleotides, at 24 h post-fertilization (hpf) Bad defects induced abnormal hindbrain development, as determined in a tissue section by means of HE staining which traced the damaged hindbrain. Then, genome-wide approaches for monitoring either the upregulation of apoptotic-related genes (11.8%) or the downregulation of brain development-related genes (29%) at the 24 hpf stage were implemented. The p53/caspase-8-mediated apoptotic death pathway was strongly involved, with the pathway being strongly reversed in a p53 mutant (p53M214K) line during Bad knockdown. Furthermore, we propose the involvement of a p53-mediated stress signal which is correlated with regulating Bad loss-mediated brain defects. We found that some major genes in brain development, such as crybb1, pva1b5, irx4a, pax7a, and fabp7a, were dramatically restored in the p53M214K line, and brain development recovered to return movement behavior to normal. Our findings suggest that Bad is required for (PCD) control, exerting a p53 stress signal on caspase-8/tBid-mediated death signaling and brain development-related gene regulation.
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Affiliation(s)
- Jo-Chi Hung
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan; (J.-C.H.); (H.-C.L.); (H.-W.C.)
| | - Jen-Leih Wu
- Laboratory of Marine Molecular Biology and Biotechnology, Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei 115, Taiwan;
| | - Huei-Ching Li
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan; (J.-C.H.); (H.-C.L.); (H.-W.C.)
| | - Hsuan-Wen Chiu
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan; (J.-C.H.); (H.-C.L.); (H.-W.C.)
| | - Jiann-Ruey Hong
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan; (J.-C.H.); (H.-C.L.); (H.-W.C.)
- Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, Tainan 701, Taiwan
- Correspondence: ; Tel.: +886-6-2003082; Fax: +886-6-2766505
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Chen KW, Chiu HW, Chiu YW, Wu JL, Hong JR. EPA and DHA can modulate cell death via inhibition of the Fas/tBid-mediated signaling pathway with ISKNV infection in grouper fin cell line (GF-1) cells. Fish Shellfish Immunol 2020; 97:608-616. [PMID: 31614198 DOI: 10.1016/j.fsi.2019.10.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Revised: 10/05/2019] [Accepted: 10/11/2019] [Indexed: 06/10/2023]
Abstract
Polyunsaturated fatty acids (PUFAs) play important roles in organisms, including the structure and liquidity of cell membranes, anti-oxidation and anti-inflammation. Very little has been done in terms of the effect of PUFAs on cell death, especially on DNA virus. In this study, we demonstrated that the infectious spleen and kidney necrosis virus (ISKNV) can induce host cell death via the apoptotic cell death pathway, which correlated to modulation by PUFAs in grouper fin cell line (GF-1) cells. We screened the PUFAs, including docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), for the ability of different dosages to prevent cell death in GF-1 cells with ISKNV infection. In the results, each 10 μM of DHA and EPA treatment enhanced host cell viability up to 80% at day 5 post-infection. Then, in Terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL) assay, DHA- and EPA-treated groups reduced TUNEL positive signals 50% in GF-1 cells with ISKNV infection. Then, through studies of the mechanism of cell death, we found that ISKNV can induce both the Bax/caspase-3 and Fas/caspase-8/tBid death signaling pathways in GF-1 cells, especially at day 5 post-infection. Furthermore, we found that DHA and EPA treatment can either prevent caspase-3 activation on 17-kDa form cleavage or Bid cleaved (15-kDa form) for activation by caspase-8, apparently. On the other hand, the anti-apoptotic gene Bcl-2 was upregulated 0.3-fold and 0.15-fold at day 3 and day 5, respectively, compared to ISKNV-infected and DHA-treated cells; that this did not happen in the EPA-treated group showed that different PUFAs trigger different signals. Finally, ISKNV-infected GF-1 cells treated with either DHA or EPA showed a 5-fold difference in viral titer at day 5. Taken together, these results suggest that optimal PUFA treatment can affect cell death signaling through both the intrinsic and extrinsic death pathways, reducing viral expression and viral titer in GF-1 cells. This finding may provide insight in DNA virus infection and control.
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Affiliation(s)
- Kuang-Wen Chen
- Laboratory of Molecular Virology and Biotechnology, Department of Biotechnology and Bioindustry Sciences, Institute of Biotechnology, National Cheng Kung University, No 1. University Road, Tainan City, 701, Taiwan, ROC; Institute of Biotechnology, National Cheng Kung University, No 1. University Road, Tainan City, 701, Taiwan, ROC
| | - Hsuan-Wen Chiu
- Laboratory of Molecular Virology and Biotechnology, Department of Biotechnology and Bioindustry Sciences, Institute of Biotechnology, National Cheng Kung University, No 1. University Road, Tainan City, 701, Taiwan, ROC; Institute of Biotechnology, National Cheng Kung University, No 1. University Road, Tainan City, 701, Taiwan, ROC
| | - Yu-Wei Chiu
- Laboratory of Molecular Virology and Biotechnology, Department of Biotechnology and Bioindustry Sciences, Institute of Biotechnology, National Cheng Kung University, No 1. University Road, Tainan City, 701, Taiwan, ROC; Institute of Biotechnology, National Cheng Kung University, No 1. University Road, Tainan City, 701, Taiwan, ROC
| | - Jen-Leih Wu
- Laboratory of Marine Molecular Biology and Biotechnology, Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, 115, Taiwan, ROC.
| | - Jiann-Ruey Hong
- Laboratory of Molecular Virology and Biotechnology, Department of Biotechnology and Bioindustry Sciences, Institute of Biotechnology, National Cheng Kung University, No 1. University Road, Tainan City, 701, Taiwan, ROC; Institute of Biotechnology, National Cheng Kung University, No 1. University Road, Tainan City, 701, Taiwan, ROC.
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Su YC, Reshi L, Chen LJ, Li WH, Chiu HW, Hong JR. Nuclear targeting of the betanodavirus B1 protein via two arginine-rich domains induces G1/S cell cycle arrest mediated by upregulation of p53/p21. Sci Rep 2018; 8:3079. [PMID: 29449573 PMCID: PMC5814437 DOI: 10.1038/s41598-018-21340-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 02/02/2018] [Indexed: 12/20/2022] Open
Abstract
The molecular functions of betanodavirus non-structural protein B and its role in host cell survival remain unclear. In the present study, we examined the roles of specific nuclear targeting domains in B1 localization as well as the effect of B1 nuclear localization on the cell cycle and host cell survival. The B1 protein of the Red spotted grouper nervous necrosis virus (RGNNV) was detected in GF-1 grouper cells as early as 24 hours post-infection (hpi). Using an EYFP-B1 fusion construct, we observed nuclear localization of the B1 protein (up to 99%) in GF-1 cells at 48 hpi. The nuclear localization of B1 was mediated by two arginine-rich nuclear targeting domains (B domain: 46RRSRR51; C domain: 63RDKRPRR70) and domain C was more important than domain B in this process. B1 nuclear localization correlated with upregulation of p53 and p21(wef1/cip1); downregulation of Cyclin D1, CDK4 and Mdm2; and G1/S cell cycle arrest in GF-1 cells. In conclusion, nuclear targeting of the RGNNV B1 protein via two targeting domains causes cell cycle arrest by up-regulating p53/p21 and down-regulating Mdm2, thereby regulating host cell survival.
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Affiliation(s)
- Yu-Chin Su
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan, 701, Taiwan
| | - Latif Reshi
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan, 701, Taiwan.,Department of Life Science, College of Bioscience & Biotechnology, National Cheng Kung University, Tainan, 701, Taiwan
| | - Lei-Jia Chen
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan, 701, Taiwan
| | - Wei-Han Li
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan, 701, Taiwan
| | - Hsuan-Wen Chiu
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan, 701, Taiwan
| | - Jiann-Ruey Hong
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan, 701, Taiwan. .,Department of Biotechnology and Bioindustry, National Cheng Kung University, Tainan, 701, Taiwan.
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Chiu HW, Su YC, Hong JR. Betanodavirus B2 protein triggers apoptosis and necroptosis in lung cancer cells that suppresses autophagy. Oncotarget 2017; 8:94129-94141. [PMID: 29212215 PMCID: PMC5706861 DOI: 10.18632/oncotarget.21588] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 09/21/2017] [Indexed: 11/25/2022] Open
Abstract
The betanodavirus B2 protein targets the mitochondria and acts as a "death factor", but its effect on lung cancer cells is unknown. We examined the effect of the B2 protein on triggering apoptosis or necroptosis via P53-dependent and P53-independent pathways and increased in suppression of autophagy. The B2 protein targets the mitochondria of A549 (P53+/+) and H1299 (P53-/-) lung cancer cells due to a specific signal sequence (41RTFVISAHAA50). This triggers generation of reactive oxygen species within the mitochondria, and a minor stress response in A549 cells, but a strong stress response in H1299 cells. We examined the molecular mechanism of this cell death pathway, and found that B2 protein induces the P53/Bax-mediated apoptotic pathway in A549 cells, and that a P53 specific inhibitor (pifithrin-α) switches this response to RIP3-mediated necroptosis. On the other hand, B2 induces RIP3-mediated necroptosis pathway in H1299 cells, and a necroptosis inhibitor (necrostatin-1) switches this response to the apoptotic pathway. Both types of cell death signals inhibited autophagy via a tightly increased balance of beclin-1 and Bcl-2. Thus, B2 protein triggers P53-dependent apoptosis in A549 cells and ROS/RIP3-mediated necroptosis in H1299 cells, and crosstalk of these pathways limits initiation of autophagy. These findings provide new insights into the possible control and treatment of lung cancer.
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Affiliation(s)
- Hsuan-Wen Chiu
- Department of Biotechnology and Bioindustry, Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
| | - Yu-Chin Su
- Department of Biotechnology and Bioindustry, Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
| | - Jiann-Ruey Hong
- Department of Biotechnology and Bioindustry, Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
- Department of Biotechnology and Bioindustry, National Cheng Kung University, Tainan 701, Taiwan
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Reshi L, Wang HV, Hui CF, Su YC, Hong JR. Anti-apoptotic genes Bcl-2 and Bcl-xL overexpression can block iridovirus serine/threonine kinase-induced Bax/mitochondria-mediated cell death in GF-1 cells. Fish Shellfish Immunol 2017; 61:120-129. [PMID: 28025159 DOI: 10.1016/j.fsi.2016.12.026] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Revised: 12/13/2016] [Accepted: 12/22/2016] [Indexed: 06/06/2023]
Abstract
Although serine/threonine (ST) kinase is known to induce host cell death in GF-1 cells, it remains unclear how ST kinase induces mitochondrial function loss. In the present study, we addressed the issue of mitochondrial function loss by determining whether the Bcl-2 family members Bcl-2 and Bcl-xL can prevent ST kinase-induced cell death activity via interacting with the pro-apoptotic gene Bax. Grouper fin cells (GF-1) carrying EGFP-Bal-xL and EGFP-Bcl-2 fused genes were selected, established in cell culture, and used to examine the involvement of Bcl-2 and Bcl-xL overexpression in protection of GF-1 cells from the effects of the giant sea perch iridovirus (GSIV) ST kinase gene. Using the TUNEL assay, we found that EGFP-Bcl-2 and EGFP-Bcl-xL reduced GSIV ST kinase-induced apoptosis to 20% all at 24 h and 48 h post-transfection (pt). Also, Bcl-2 and Bcl-xL substantially reduced the percentage of cells with GSIV ST kinase-induced loss of mitochondrial membrane potential (Δψps) at 24 and 48 hpt, respectively, and this reduction correlated with a 30% and 50% enhancement of host cell viability at 24 and 48 hpt as compared with vector control. Moreover, analysis of the effect of Bcl-2 and Bcl-xL interaction with Bax targeted to mitochondria during ST kinase expression at 48 hpt found that Bcl-2 and Bcl-xL also interacted with Bax to block cytochrome c release. Finally, Bcl-2 and Bcl-xL overexpression caused blockage of ST kinase function at 48 hpt, which was correlated with preventing caspase-9 and -3 cleavage and activation, thereby blocking downstream death signaling events. Taken together, our results suggest that the ST kinase-induced Bax/mitochondria-mediated cell death pathway can be blocked by the interaction of Bcl-2 and Bcl-xL with Bax to inhibit cytochrome c release during MMP loss. This rescue activity also correlated with inhibition of caspase-9 and -3 activation, thereby enhancing cell viability.
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Affiliation(s)
- Latif Reshi
- Lab of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, No. 1 University Road, Tainan City 701, Taiwan, ROC; Department of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, No. 1 University Road, Tainan City 701, Taiwan, ROC
| | - Hua-Ven Wang
- Department of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, No. 1 University Road, Tainan City 701, Taiwan, ROC
| | - Cho-Fat Hui
- Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei 115, Taiwan, ROC
| | - Yu-Chin Su
- Lab of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, No. 1 University Road, Tainan City 701, Taiwan, ROC
| | - Jiann-Ruey Hong
- Lab of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, No. 1 University Road, Tainan City 701, Taiwan, ROC; Department of Biotechnology and Bioindustry, National Cheng Kung University, No. 1 University Road, Tainan City 701, Taiwan, ROC.
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Reshi L, Wu HC, Wu JL, Wang HV, Hong JR. GSIV serine/threonine kinase can induce apoptotic cell death via p53 and pro-apoptotic gene Bax upregulation in fish cells. Apoptosis 2016; 21:443-58. [PMID: 26833308 DOI: 10.1007/s10495-016-1219-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Previous studies have shown that GSIV induces apoptotic cell death through upregulation of the pro-apoptotic genes Bax and Bak in Grouper fin cells (GF-1 cells). However, the role of viral genome-encoded protein(s) in this death process remains unknown. In this study, we demonstrated that the Giant seaperch iridovirus (GSIV) genome encoded a serine/threonine kinase (ST kinase) protein, and induced apoptotic cell death via a p53-mediated Bax upregulation approach and a downregulation of Bcl-2 in fish cells. The ST kinase expression profile was identified through Western blot analyses, which indicated that expression started at day 1 h post-infection (PI), increased up to day 3, and then decreased by day 5 PI. This profile indicated the role of ST kinase expression during the early and middle phases of viral replication. We then cloned the ST kinase gene and tested its function in fish cells. The ST kinase was transiently expressed and used to investigate possible novel protein functions. The transient expression of ST kinase in GF-1 cells resulted in apoptotic cell features, as revealed with Terminal deoxynucleotidyl transferase biotin-dUTP nick-end labeling (TUNEL) assays and Hoechst 33258 staining at 24 h (37 %) and 48 h post-transfection (PT) (49 %). Then, through studies on the mechanism of cell death, we found that ST kinase overexpression could upregulate the anti-stress gene p53 and the pro-apoptotic gene Bax at 48 h PT. Interestingly, this upregulation of p53 and Bax also correlated to alterations in the mitochondria function that induced loss of mitochondrial membrane potential (MMP) and activated the initiator caspase-9 and the effector caspase-3 in the downstream. Moreover, when the p53-dependent transcriptional downstream gene was blocked by a specific transcriptional inhibitor, it was found that pifithrin-α not only reduced Bax expression, but also averted cell death in GF-1 cells during the ST kinase overexpression. Taken altogether, these results suggested that aquatic GSIV ST kinase could induce apoptosis via upregulation of p53 and Bax expression, resulting in mitochondrial disruption, which activated a downstream caspases-mediated cell death pathway.
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Affiliation(s)
- Latif Reshi
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, No 1. University Road, Tainan City, 701, Taiwan, ROC.,Department of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, No. 1. University Road, Tainan City, 701, Taiwan, ROC
| | - Horng-Cherng Wu
- Laboratory Department of Food Science and Technology, Chin Nan University of Pharmacy and Science, Tainan, 717, Taiwan, ROC
| | - Jen-Leih Wu
- Laboratory of Marine Molecular Biology and Biotechnology, Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, 115, Taiwan, ROC
| | - Hao-Ven Wang
- Department of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, No. 1. University Road, Tainan City, 701, Taiwan, ROC
| | - Jiann-Ruey Hong
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, No 1. University Road, Tainan City, 701, Taiwan, ROC.
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Shiu WL, Huang KR, Hung JC, Wu JL, Hong JR. Knockdown of zebrafish YY1a can downregulate the phosphatidylserine (PS) receptor expression, leading to induce the abnormal brain and heart development. J Biomed Sci 2016; 23:31. [PMID: 26924789 PMCID: PMC4770675 DOI: 10.1186/s12929-016-0248-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 02/16/2016] [Indexed: 01/08/2023] Open
Abstract
Background Yin Yang 1 (YY1) is a ubiquitously expressed GLI-Kruppel zinc finger-containing transcriptional regulator. YY1 plays a fundamental role in normal biologic processes such as embryogenesis, differentiation, and cellular proliferation. YY1 effects on the genes involved in these processes are mediated via initiation, activation, or repression of transcription depending upon the context in which it binds. The role of the multifunctional transcription factor Yin Yang 1 (YY1) in tissue development is poorly understood. In the present, we investigated YY1a role in developing zebrafish on PSR-mediated apoptotic cell engulfment during organic morphogenesis. Results YY1a is first expressed 0.5 h post-fertilization (hpf), in the whole embryo 12 hpf, and in brain, eyes, and heart 72 hpf by in situ hybridization assay. The nucleotide sequence of zebrafish YY1a transcription factor (clone zfYY1a; HQ 166834) was found to be similar to that of zebrafish YY1a (99 % sequence identity; NM 212617). With the loss-of-function assay, YY1a knockdown by a morpholino oligonucleotide led to downregulation of the phosphatidylserine engulfing receptor zfPSR during embryonic segmentation and to the accumulation of a large number of dead apoptotic cells throughout the entire early embryo, especially in the posterior area. Up to 24 hpf, these cells interfered with embryonic cell migration and cell-cell interactions that normally occur in the brain, heart, eye, and notochord. Finally, with gain-of-function assay, defective morphants could be rescued by injecting both YY1a mRNA and PSR mRNA and trigger resumption of normal development. Conclusions Taken together, our results suggest that YY1a regulates PS receptor expression that linked to function of PSR-phagocyte mediated apoptotic cell engulfment during development, especially the development of organs such as the brain and heart. YY1a/PSR-mediated engulfing system may involve in diseases.
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Affiliation(s)
- Wei-Lun Shiu
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan, 701, Taiwan, ROC
| | - Kuan-Rong Huang
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan, 701, Taiwan, ROC
| | - Jo-Chi Hung
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan, 701, Taiwan, ROC
| | - Jen-Leih Wu
- Laboratory of Marine Molecular Biology and Biotechnology, Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei, 115, Taiwan, ROC
| | - Jiann-Ruey Hong
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan, 701, Taiwan, ROC.
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11
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Chen XY, Wen CM, Wu JL, Su YC, Hong JR. Giant seaperch iridovirus (GSIV) induces mitochondria-mediated cell death that is suppressed by bongkrekic acid and cycloheximide in a fish cell line. Virus Res 2015; 213:37-45. [PMID: 26548846 DOI: 10.1016/j.virusres.2015.11.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 10/30/2015] [Accepted: 11/02/2015] [Indexed: 12/20/2022]
Abstract
Giant seaperch iridovirus (GSIV) induces cell death by an unknown mechanism. We postulated that this mechanism involves mitochondria-mediated cell death. Cell viability assays revealed a steady increase in dead grouper fin cells (GF-1) after GSIV infection, from 11% at 2 days post-infection (dpi) to 67% at 5 dpi. Annexin V/PI staining revealed GSIV infection induced apoptosis in a steadily increasing fraction of cells, from 4% at 1 dpi to 29% at 5 dpi. Furthermore, post-apoptotic necrosis was apparent at 4 and 5 dpi in the late replication stage. In the early replication stage, JC-1 dye revealed mitochondrial membrane potential (ΔΨm) loss in 42% of infected cells at 1 dpi, increasing to 98% at 3 dpi. Phosphatidylserine (PS) exposure and loss of ΔΨm from apoptosis/necrosis was attenuated by treatment with the adenine nucleotide translocase inhibitor bongkrekic acid (BKA) and the protein synthesis inhibitor cyclohexamide (CHX). These data suggest GSIV induces GF-1 apoptotic/necrotic cell death through pathways that require newly synthesized protein and involve the mitochondrial function.
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Affiliation(s)
- Xin-Yu Chen
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng-Kung University, Tainan 701, Taiwan
| | - Chiu-Ming Wen
- Department of Life Sciences, National University of Kaohsiung, Kaohsiung 811, Taiwan
| | - Jen-Leih Wu
- Laboratory of Marine Molecular Biology and Biotechnology, Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei 115, Taiwan
| | - Yu-Chin Su
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng-Kung University, Tainan 701, Taiwan
| | - Jiann-Ruey Hong
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng-Kung University, Tainan 701, Taiwan.
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12
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Reshi L, Wu JL, Wang HV, Hong JR. Aquatic viruses induce host cell death pathways and its application. Virus Res 2015; 211:133-44. [PMID: 26494167 DOI: 10.1016/j.virusres.2015.10.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 10/07/2015] [Accepted: 10/14/2015] [Indexed: 11/15/2022]
Abstract
Virus infections of mammalian and animal cells consist of a series of events. As intracellular parasites, viruses rely on the use of host cellular machinery. Through the use of cell culture and molecular approaches over the past decade, our knowledge of the biology of aquatic viruses has grown exponentially. The increase in aquaculture operations worldwide has provided new approaches for the transmission of aquatic viruses that include RNA and DNA viruses. Therefore, the struggle between the virus and the host for control of the cell's death machinery is crucial for survival. Viruses are obligatory intracellular parasites and, as such, must modulate apoptotic pathways to control the lifespan of their host to complete their replication cycle. This paper updates the discussion on the detailed mechanisms of action that various aquatic viruses use to induce cell death pathways in the host, such as Bad-mediated, mitochondria-mediated, ROS-mediated and Fas-mediated cell death circuits. Understanding how viruses exploit the apoptotic pathways of their hosts may provide great opportunities for the development of future potential therapeutic strategies and pathogenic insights into different aquatic viral diseases.
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Affiliation(s)
- Latif Reshi
- Laboratory of Molecular Virology and Biotechnology, College of Bioscience and Biotechnology, Institute of Biotechnology, National Cheng Kung University, No 1. University Road, Tainan City 701, Taiwan, ROC; Department of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, No. 1. University Road, Tainan City 701, Taiwan, ROC
| | - Jen-Leih Wu
- Laboratory of Marine Molecular Biology and Biotechnology, Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei 115, Taiwan, ROC
| | - Hao-Ven Wang
- Department of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, No. 1. University Road, Tainan City 701, Taiwan, ROC
| | - Jiann-Ruey Hong
- Laboratory of Molecular Virology and Biotechnology, College of Bioscience and Biotechnology, Institute of Biotechnology, National Cheng Kung University, No 1. University Road, Tainan City 701, Taiwan, ROC.
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13
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Chen XY, Wen CM, Hui CF, Chen MC, Wu JL, Hsueh TC, Lei WH, Hong JR. Giant seaperch iridovirus infection upregulates Bas and Bak expression, leading to apoptotic death of fish cells. Fish Shellfish Immunol 2015; 45:848-857. [PMID: 26067170 DOI: 10.1016/j.fsi.2015.06.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 05/29/2015] [Accepted: 06/03/2015] [Indexed: 06/04/2023]
Abstract
The giant seaperch iridovirus (GSIV) induces host cell apoptosis by a poorly-understood process. In this study, GSIV is shown to upregulate the pro-apoptotic death genes Bax and Bak at the middle replication stage, and factors in the grouper fin cell line (GF-1) are shown to modulate this process. Studying the mechanism of cell death, we found that upregulated, de novo-synthesized Bax and Bak proteins formed heterodimers. This up-regulation process correlated with mitochondrial membrane potential (MMP) loss, increased caspase-3 activity, and increased apoptotic cell death. All effects were diminished by treatment of infected GF-1 cells with the protein synthesis inhibitor cycloheximide. Interestingly, overexpression of the anti-apoptotic gene Bcl-xL also diminished GSIV-induced mitochondria-mediated cell death, increasing host cell viability and decreasing MMP loss at the early replication stage. Our data suggest that GSIV induces GF-1 apoptotic cell death through up-regulation of the pro-apoptotic genes Bax and Bak, which are regulated by Bcl-xL overexpression on mitochondria in GF-1 cells.
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Affiliation(s)
- Xin-Yu Chen
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng-Kung University, Tainan 701, Taiwan
| | - Chiu-Ming Wen
- Department of Life Sciences, National University of Kaohsiung, Kaohsiung 811, Taiwan
| | - Cho-Fat Hui
- Laboratory of Marine Molecular Biology and Biotechnology, Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei 115, Taiwan
| | - Ming-Chyuan Chen
- Department of Marine Biotechnology, National Kaohsiung Marine University, Kaohsiung 811, Taiwan
| | - Jen-Leih Wu
- Laboratory of Marine Molecular Biology and Biotechnology, Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei 115, Taiwan
| | - Tsai-Ching Hsueh
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng-Kung University, Tainan 701, Taiwan
| | - Wei-Han Lei
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng-Kung University, Tainan 701, Taiwan
| | - Jiann-Ruey Hong
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng-Kung University, Tainan 701, Taiwan.
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14
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Kung HC, Evensen Ø, Hong JR, Kuo CY, Tso CH, Ngou FH, Lu MW, Wu JL. Interferon regulatory factor-1 (IRF-1) is involved in the induction of phosphatidylserine receptor (PSR) in response to dsRNA virus infection and contributes to apoptotic cell clearance in CHSE-214 cell. Int J Mol Sci 2014; 15:19281-306. [PMID: 25342322 PMCID: PMC4227274 DOI: 10.3390/ijms151019281] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 10/13/2014] [Accepted: 10/14/2014] [Indexed: 11/16/2022] Open
Abstract
The phosphatidylserine receptor (PSR) recognizes a surface marker on apoptotic cells and initiates engulfment. This receptor is important for effective apoptotic cell clearance and maintains normal tissue homeostasis and regulation of the immune response. However, the regulation of PSR expression remains poorly understood. In this study, we determined that interferon regulatory factor-1 (IRF-1) was dramatically upregulated upon viral infection in the fish cell. We observed apoptosis in virus-infected cells and found that both PSR and IRF-1 increased simultaneously. Based on a bioinformatics promoter assay, IRF-1 binding sites were identified in the PSR promoter. Compared to normal viral infection, we found that PSR expression was delayed, viral replication was increased and virus-induced apoptosis was inhibited following IRF-1 suppression with morpholino oligonucleotides. A luciferase assay to analyze promoter activity revealed a decreasing trend after the deletion of the IRF-1 binding site on PSR promoter. The results of this study indicated that infectious pancreatic necrosis virus (IPNV) infection induced both the apoptotic and interferon (IFN) pathways, and IRF-1 was involved in regulating PSR expression to induce anti-viral effects. Therefore, this work suggests that PSR expression in salmonid cells during IPNV infection is activated when IRF-1 binds the PSR promoter. This is the first report to show the potential role of IRF-1 in triggering the induction of apoptotic cell clearance-related genes during viral infection and demonstrates the extensive crosstalk between the apoptotic and innate immune response pathways.
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Affiliation(s)
- Hsin-Chia Kung
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11574, Taiwan.
| | - Øystein Evensen
- Department of Basic Sciences and Aquatic Medicine, Norwegian University of Life Sciences, Oslo 0454, Norway.
| | - Jiann-Ruey Hong
- Institute of Biotechnology, National Cheng-Kung University, Tainan 70101, Taiwan.
| | - Chia-Yu Kuo
- Department of Aquaculture, National Taiwan Ocean University, Keelung 20224, Taiwan.
| | - Chun-Hsi Tso
- Department of Aquaculture, National Taiwan Ocean University, Keelung 20224, Taiwan.
| | - Fang-Huar Ngou
- Department of Aquaculture, National Taiwan Ocean University, Keelung 20224, Taiwan.
| | - Ming-Wei Lu
- Department of Aquaculture, National Taiwan Ocean University, Keelung 20224, Taiwan.
| | - Jen-Leih Wu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11574, Taiwan.
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15
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Reshi ML, Wu JL, Wang HV, Hong JR. RNA interference technology used for the study of aquatic virus infections. Fish Shellfish Immunol 2014; 40:14-23. [PMID: 24945574 DOI: 10.1016/j.fsi.2014.06.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 06/05/2014] [Accepted: 06/09/2014] [Indexed: 06/03/2023]
Abstract
Aquaculture is one of the most important economic activities in Asia and is presently the fastest growing sector of food production in the world. Explosive increases in global fish farming have been accompanied by an increase in viral diseases. Viral infections are responsible for huge economic losses in fish farming, and control of these viral diseases in aquaculture remains a serious challenge. Recent advances in biotechnology have had a significant impact on disease reduction in aquaculture. RNAi is one of the most important technological breakthroughs in modern biology, allowing us to directly observe the effects of the loss of specific genes in living systems. RNA interference technology has emerged as a powerful tool for manipulating gene expression in the laboratory. This technology represents a new therapeutic approach for treating aquatic diseases, including viral infections. RNAi technology is based on a naturally occurring post-transcriptional gene silencing process mediated by the formation of dsRNA. RNAi has been proven widely effective for gene knockdown in mammalian cultured cells, but its utility in fish remains unexplored. This review aims to highlight the RNAi technology that has made significant contributions toward the improvement of aquatic animal health and will also summarize the current status and future strategies concerning the therapeutic applications of RNAi to combat viral disease in aquacultured organisms.
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Affiliation(s)
- Mohammad Latif Reshi
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, No 1, University Road, Tainan City 701, Taiwan, ROC; Department of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, No. 1, University Road, Tainan City 701, Taiwan, ROC
| | - Jen-Leih Wu
- Laboratory of Marine Molecular Biology and Biotechnology, Institute of Cellular and Organismic Biology, Academia Sinica, Nankang, Taipei 115, Taiwan, ROC
| | - Hao-Ven Wang
- Department of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, No. 1, University Road, Tainan City 701, Taiwan, ROC
| | - Jiann-Ruey Hong
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, No 1, University Road, Tainan City 701, Taiwan, ROC.
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16
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Abstract
Reactive oxygen species (ROS) are well known for being both beneficial and deleterious. The main thrust of this review is to investigate the role of ROS in ribonucleic acid (RNA) virus pathogenesis. Much evidences has accumulated over the past decade, suggesting that patients infected with RNA viruses are under chronic oxidative stress. Changes to the body's antioxidant defense system, in relation to SOD, ascorbic acid, selenium, carotenoids, and glutathione, have been reported in various tissues of RNA-virus infected patients. This review focuses on RNA viruses and retroviruses, giving particular attention to the human influenza virus, Hepatitis c virus (HCV), human immunodeficiency virus (HIV), and the aquatic Betanodavirus. Oxidative stress via RNA virus infections can contribute to several aspects of viral disease pathogenesis including apoptosis, loss of immune function, viral replication, inflammatory response, and loss of body weight. We focus on how ROS production is correlated with host cell death. Moreover, ROS may play an important role as a signal molecule in the regulation of viral replication and organelle function, potentially providing new insights in the prevention and treatment of RNA viruses and retrovirus infections.
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Affiliation(s)
- Mohammad Latif Reshi
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
- Department of Life Sciences, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
| | - Yi-Che Su
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
| | - Jiann-Ruey Hong
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
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17
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Abstract
Betanodaviruses cause viral nervous necrosis, an infectious neuropathological condition in fish that is characterized by necrosis of the central nervous system, including the brain and retina. This disease can cause mass mortality in larval and juvenile populations of several teleost species and is of global economic importance. The mechanism of brain and retina damage during betanodavirus infection is poorly understood. In this review, we will focus recent results that highlight betanodavirus infection-induced molecular death mechanisms in vitro. Betanodavirus can induce host cellular death and post-apoptotic necrosis in fish cells. Betanodavirus-induced necrotic cell death is also correlated with loss of mitochondrial membrane potential in fish cells, as this necrotic cell death is blocked by the mitochondrial membrane permeability transition pore inhibitor bongkrekic acid and the expression of the anti-apoptotic Bcl-2 family member zfBcl-xL. Moreover, this mitochondria-mediated necrotic cell death may require a caspase-independent pathway. A possible cellular death pathway involving mitochondrial function and the modulator zfBcl-xs is discussed which may provide new insights into the necrotic pathogenesis of betanodavirus.
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18
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Abstract
When clinicians treat patients with pesticide poisoning, they often pay attention only to the chief toxic agent and ignore the toxicity of the pesticide’s additives or solvents. Occasionally, however, a solvent (e.g. methanol) may itself be the cause of poisoning. We report a case of acute methanol intoxication that occurred after ingestion of a methomyl pesticide that contained methanol as an additive. A 49-year-old man was brought to the emergency department in an unconscious state after ingestion of 20 ml of a carbamate pesticide (chief ingredient: methomyl; active ingredient: methanol). Upon arrival, he was semicomatose and did not breathe spontaneously; however, his cholinesterase level was within normal limits and cholinergic symptoms were not observed. High anion gap metabolic acidosis was present. His blood ethanol level was 74.8 mg/dL. The urine methanol level was 55.60 mg/dL, and urine ethanol level was 22.0 mg/dL. He was treated with hemodialysis; subsequently, his metabolic acidosis resolved and he returned to normal mental status. We guessed that methanol, as the solvent of the methomyl, had produced the symptoms. When treating pesticide-poisoned patients, clinicians should identify the solvent used in the pesticide, because solvents such as methanol may exacerbate the symptoms of poisoned patients.
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Affiliation(s)
- HW Gil
- Department of Internal Medicine, Soonchunhyang University, Cheonan Hospital, Cheonan, Kore
| | - JR Hong
- Department of Internal Medicine, Soonchunhyang University, Cheonan Hospital, Cheonan, Kore
| | - HY Song
- Department of Immunology, College of Medicine, Soonchunhyang University, Cheonan, Korea
| | - SY Hong
- Department of Internal Medicine, Soonchunhyang University, Cheonan Hospital, Cheonan, Kore
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Huang HL, Liu YT, Chen MC, Wu JL, Hong JR. Zebrafish anti-apoptotic gene Bcl-xL can prevent aquatic birnavirus-induced cell death in fish cells without affecting expression of viral proteins. Fish Shellfish Immunol 2011; 31:970-977. [PMID: 21906684 DOI: 10.1016/j.fsi.2011.08.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 08/18/2011] [Accepted: 08/20/2011] [Indexed: 05/31/2023]
Abstract
The aquatic birnavirus induces mitochondria-mediated cell death in fish; however, the molecular mechanism remains unknown. In the present study, we demonstrated that aquatic birnavirus-induced mitochondria-mediated cell death is regulated by the anti-apoptotic Bcl-2 family member, zfBcl-xL, which is anti-apoptotic and enhances host cell viability. First, CHSE-214 cells carrying EGFP-zfBcl-xL fused genes were selected, established in culture, and used to examine the involvement of zfBcl-xL in host cell protection from the effects of viral infection. EGFP-zfBcl-xL was found to prevent infectious pancreatic necrosis virus (IPNV)-induced phosphatidylserine exposure up to 40% at 12 h and 24 h post-infection (p.i.), block IPNV-induced loss of mitochondrial membrane potential (ΔΨm), and enhance host viability at the middle and late replication stages. In addition, zfBcl-xL overexpression prevented IPNV-induced caspase-9 activation up to 25% and 85% at the middle (12 h p.i.) and late (24 h p.i.) replication stages without affecting expression of viral proteins such as VP3 (as a viral death protein) protein. In the present study, we demonstrated that aquatic birnavirus-induced cell death is prevented by the anti-apoptotic Bcl-2 family member, zfBcl-xL, which enhances host cell viability through blockage of mitochondrial disruption and caspase-9 activation.
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Affiliation(s)
- Hui-Ling Huang
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
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Chang CW, Su YC, Her GM, Ken CF, Hong JR. Betanodavirus induces oxidative stress-mediated cell death that prevented by anti-oxidants and zfcatalase in fish cells. PLoS One 2011; 6:e25853. [PMID: 21991373 PMCID: PMC3185053 DOI: 10.1371/journal.pone.0025853] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 09/12/2011] [Indexed: 12/21/2022] Open
Abstract
The role of oxidative stress in the pathogenesis of RNA nervous necrosis virus infection is still unknown. Red-spotted grouper nervous necrosis virus (RGNNV) induced free radical species (ROS) production at 12-24 h post-infection (pi; early replication stage) in fish GF-1 cells, and then at middle replication stage (24-48 h pi), this ROS signal may upregulate some expressions of the anti-oxidant enzymes Cu/Zn SOD and catalase, and eventually expression of the transcription factor Nrf2. Furthermore, both antioxidants diphenyliodonium and N-acetylcysteine or overexpression of zebrafish catalase in GF-1 cells also reduced ROS production and protected cells for enhancing host survival rate due to RGNNV infection. Furthermore, localization of ROS production using esterase activity and Mitotracker staining assays found that the ROS generated can affect mitochondrial morphology changes and causes ΔΨ loss, both of which can be reversed by antioxidant treatment. Taken together, our data suggest that RGNNV induced oxidative stress response for playing dual role that can initiate the host oxidative stress defense system to upregulate expression of antioxidant enzymes and induces cell death via disrupting the mitochondrial morphology and inducing ΔΨ loss, which can be reversed by anti-oxidants and zfcatalase, which provide new insight into betanodavirus-induced ROS-mediated pathogenesis.
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Affiliation(s)
- Chih-Wei Chang
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan, Taiwan, Republic of China
| | - Yu-Chin Su
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan, Taiwan, Republic of China
| | - Guor-Mour Her
- Institute of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan, Republic of China
| | - Chuian-Fu Ken
- The Department of Biotechnology, National Changhua University of Education, Changhua, Taiwan, Republic of China
| | - Jiann-Ruey Hong
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan, Taiwan, Republic of China
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Su YC, Wu JL, Hong JR. Betanodavirus up-regulates chaperone GRP78 via ER stress: roles of GRP78 in viral replication and host mitochondria-mediated cell death. Apoptosis 2011; 16:272-87. [PMID: 21170590 DOI: 10.1007/s10495-010-0565-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Whether viral pathogens that induce ER stress responses benefit the host or the virus remains controversial. In this study we show that betanodavirus induced ER stress responses up-regulate GRP78, which regulates the viral replication and host cellular mitochondrial-mediated cell death. Betanodavirus (redspotted grouper nervous necrosis virus, RGNNV) infection resulted in the following increased ER stress responses in fish GF-1 grouper fin cells: (1) IRE-1 and ATF-6 sensors at 48 h post-infection (p.i.) that up-regulated chaperone protein GRP78; (2) activation of caspase-12; and (3) PERK phosphorylation and down-regulation of Bcl-2. Analyses of GRP78 functions during viral replication using either loss-of-function or gain-of-function approaches showed that GRP78 over-expression also enhanced viral replication and induced cell death. Then, we found that zfGRP78 localization gradually increased in mitochondria after RGNNV infection by EGFP tagging approach. Furthermore, zfGRP78 can interact with viral RNA-dependent RNA polymerase (RdRp) by using immunofluorescent and immunoprecipitation assays. Finally, we found that blocking GRP78-mediated ER signals can reduce the viral death factors protein α and protein B2 expression and decrease the Bcl-2 down-regulation mediated mitochondria-dependent cell death, which also enhances host cellular viability. Taken together, our results suggest that RGNNV infection and expression can trigger ER stress responses, which up-regulate the chaperone GRP78 at early replication stage. Then, GRP78 can interact with RdRp that may enhance the viral replication for increasing viral death factors' expressions at middle-late replication stage, which can enhance mitochondrial-mediated cell death pathway and viral spreading. These results may provide new insights into the mechanism of ER stress-mediated cell death in RNA viruses.
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Affiliation(s)
- Yu-Chin Su
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan, ROC
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22
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Wang WL, Liu W, Gong HY, Hong JR, Lin CC, Wu JL. Activation of cytokine expression occurs through the TNFα/NF-κB-mediated pathway in birnavirus-infected cells. Fish Shellfish Immunol 2011; 31:10-21. [PMID: 21272652 DOI: 10.1016/j.fsi.2011.01.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2010] [Revised: 01/10/2011] [Accepted: 01/16/2011] [Indexed: 05/30/2023]
Abstract
The infectious pancreatic necrosis virus (IPNV) belongs to the Birnaviridae family of viruses and causes acute contagious diseases in a number of economically important freshwater and marine fish. In this study, we infected zebrafish embryonic cells (ZF4) with IPNV and analyzed the gene expression patterns of normal and infected cells using quantitative real-time PCR. We identified a number of immune response genes, including ifna, ifng, mx, irf1, irf2, irf4, tnfa, tnfb, il-1b, il-15, il-26, ccl4 and mmp family genes, that are induced after viral infection. Transcriptional regulators, including cebpb, junb, nfkb and stat1, stat4 and stat5, were also upregulated in IPNV-infected cells. In addition, we used Pathway Studio software to identify TNFα as having the greatest downstream influence among these altered genes. Treating virus-infected cells with an siRNA targeting TNFα inhibited NF-κB expression. To further interrupt the TNFα/NF-κB-mediated pathway, the expression levels of cytokines and metalloproteinases were inhibited in IPNV-infected cells. These data suggest that, during IPNV infection, the expression of cytokines and metalloproteinases might be initiated through the TNFα/NF-κB-mediated pathway. The modulation of TNFα/NF-κB-related mechanisms may provide a therapeutic strategy for inhibiting viral infection in teleosts.
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Affiliation(s)
- Wei-Lun Wang
- Institute of Cellular and Organismic Biology, Academia Sinica, Nankang 115, Taipei, Taiwan
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Wang WL, Hong JR, Lin GH, Liu W, Gong HY, Lu MW, Lin CC, Wu JL. Stage-specific expression of TNFα regulates bad/bid-mediated apoptosis and RIP1/ROS-mediated secondary necrosis in Birnavirus-infected fish cells. PLoS One 2011; 6:e16740. [PMID: 21304825 PMCID: PMC3033425 DOI: 10.1371/journal.pone.0016740] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2010] [Accepted: 01/05/2011] [Indexed: 01/18/2023] Open
Abstract
Infectious pancreatic necrosis virus (IPNV) can induce Bad-mediated apoptosis followed by secondary necrosis in fish cells, but it is not known how these two types of cell death are regulated by IPNV. We found that IPNV infection can regulate Bad/Bid-mediated apoptotic and Rip1/ROS-mediated necrotic death pathways via the up-regulation of TNFα in zebrafish ZF4 cells. Using a DNA microarray and quantitative RT-PCR analyses, two major subsets of differentially expressed genes were characterized, including the innate immune response gene TNFα and the pro-apoptotic genes Bad and Bid. In the early replication stage (0–6 h post-infection, or p.i.), we observed that the pro-inflammatory cytokine TNFα underwent a rapid six-fold induction. Then, during the early-middle replication stages (6–12 h p.i.), TNFα level was eight-fold induction and the pro-apoptotic Bcl-2 family members Bad and Bid were up-regulated. Furthermore, specific inhibitors of TNFα expression (AG-126 or TNFα-specific siRNA) were used to block apoptotic and necrotic death signaling during the early or early-middle stages of IPNV infection. Inhibition of TNFα expression dramatically reduced the Bad/Bid-mediated apoptotic and Rip1/ROS-mediated necrotic cell death pathways and rescued host cell viability. Moreover, we used Rip1-specific inhibitors (Nec-1 and Rip1-specific siRNA) to block Rip1 expression. The Rip1/ROS-mediated secondary necrotic pathway appeared to be reduced in IPNV-infected fish cells during the middle-late stage of infection (12–18 h p.i.). Taken together, our results indicate that IPNV triggers two death pathways via up-stream induction of the pro-inflammatory cytokine TNFα, and these results may provide new insights into the pathogenesis of RNA viruses.
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Affiliation(s)
- Wei-Lun Wang
- Institute of Fisheries Science, National Taiwan University, Taipei, Taiwan, Republic of China
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Jiann-Ruey Hong
- Institute of Biotechnology, National Cheng Kung University, Tainan, Taiwan, Republic of China
| | - Gen-Hwa Lin
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Wangta Liu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Hong-Yi Gong
- Department of Aquaculture, National Taiwan Ocean University, Keelung, Taiwan, Republic of China
| | - Ming-Wei Lu
- Department of Aquaculture, National Taiwan Ocean University, Keelung, Taiwan, Republic of China
| | - Ching-Chun Lin
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Jen-Leih Wu
- Institute of Fisheries Science, National Taiwan University, Taipei, Taiwan, Republic of China
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan, Republic of China
- * E-mail:
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24
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Su YC, Hong JR. Betanodavirus B2 causes ATP depletion-induced cell death via mitochondrial targeting and complex II inhibition in vitro and in vivo. J Biol Chem 2010; 285:39801-10. [PMID: 20870718 DOI: 10.1074/jbc.m110.164988] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The betanodavirus non-structural protein B2 is a newly discovered necrotic death factor with a still unknown role in regulation of mitochondrial function. In the present study, we examined protein B2-mediated inhibition of mitochondrial complex II activity, which results in ATP depletion and thereby in a bioenergetic crisis in vitro and in vivo. Expression of protein B2 was detected early at 24 h postinfection with red-spotted grouper nervous necrosis virus in the cytoplasm. Later B2 was found in mitochondria using enhanced yellow fluorescent protein (EYFP) and immuno-EM analysis. Furthermore, the B2 mitochondrial targeting signal peptide was analyzed by serial deletion and specific point mutation. The sequence of the B2 targeting signal peptide ((41)RTFVISAHAA(50)) was identified and its presence correlated with loss of mitochondrial membrane potential in fish cells. Protein B2 also was found to dramatically inhibit complex II (succinate dehydrogenase) activity, which impairs ATP synthesis in fish GF-1 cells as well as human embryonic kidney 293T cells. Furthermore, when B2 was injected into zebrafish embryos at the one-cell stage to determine its cytotoxicity and ability to inhibit ATP synthesis, we found that B2 caused massive embryonic cell death and depleted ATP resulting in further embryonic death at 10 and 24 h post-fertilization. Taken together, our results indicate that betanodavirus protein B2-induced cell death is due to direct targeting of the mitochondrial matrix by a specific signal peptide that targets mitochondria and inhibits mitochondrial complex II activity thereby reducing ATP synthesis.
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Affiliation(s)
- Yu-Chin Su
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
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25
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Wu HC, Wu JL, Chu HL, Su YC, Hong JR. RGNNV induces mitochondria-mediated cell death via newly synthesized protein dependent pathway in fish cells. Fish Shellfish Immunol 2010; 29:451-463. [PMID: 20641154 DOI: 10.1016/j.fsi.2010.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The RNA nervous necrosis virus induces necrotic cell death in fish; however, the molecular mechanism remains unknown. In this study, we demonstrated that beta-nodavirus-induced mitochondria-mediated dependent cell death is through newly synthesized protein dependent pathway in replication cycle. We determined that newly synthesized protein dependent pathway is required for red-spotted grouper nervous necrosis virus (RGNNV)-induced cell death. UV irradiation of the virus effectively blocked viral replication and cell death. Next, RGNNV RNA-dependent RNA polymerase (RdRp or protein A) was cloned and its involvement in RNA genome replication and viral protein synthesis was analyzed. Protein A was initially expressed 48 h post-infection and localized to the cytoplasm. Knockdown of protein A expression completely blocked viral genomic replication and expression of viral protein expression RNA1 small hairpin RNA (shRNA) producing cell lines, which coincided with inhibition of phosphatidylserine exposure, mitochondria-mediated death signaling, and increased cell viability 72 h post-infection. Furthermore, RGNNV-induced mitochondria-mediated caspase-3-independent necrotic cell death is dependent on viral synthesized protein dependent pathway at the middle-late replication stage. Taken together, for instance these results suggested that RGNNV induces cell death may require newly synthesized protein for triggering host mitochondria-mediated cell death. These findings may provide new insights into RNA viral pathogenesis.
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Affiliation(s)
- Horng-Cherng Wu
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan, ROC
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26
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Hsu CC, Hou MF, Hong JR, Wu JL, Her GM. Inducible male infertility by targeted cell ablation in zebrafish testis. Mar Biotechnol (NY) 2010; 12:466-478. [PMID: 19936986 DOI: 10.1007/s10126-009-9248-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Accepted: 09/22/2009] [Indexed: 05/28/2023]
Abstract
To generate a zebrafish model of inducible male sterility, we expressed an Escherichia coli nitroreductase (Ntr) gene in the male germ line of zebrafish. The Ntr gene encodes an enzyme that can convert prodrugs such as metronidazole (Met) to cytotoxins. A fusion protein eGFP:Ntr (fusing Ntr to eGFP) under control of approximately 2 kb putative promoters of the zebrafish testis-specific genes, A-kinase anchoring protein-associated protein (Asp), outer dense fibers (Odf), and sperm acrosomal membrane-associated protein (Sam) was expressed in the male germ line. Three independent and four compound transgenic zebrafish lines expressing eGFP:Ntr were established. Female carriers were fertile, while males exhibited different levels of sterility and appeared normal, otherwise. Developmental analysis shows that germ cells survived and testes were normal before Met treatment, but that the testes of all male transgenic zebrafish exhibited variously depleted prospermatogonia after Met treatment. Particularly in a triple-transgenic line, Tg(AOS-eGFP:Ntr)[Tg(Asp-eGFP:Ntr; Odf-eGFP:Ntr; Sam-eGFP:Ntr)], the transgenic males had very small testes that were virtually devoid of germ cells, and the residual germ cells had almost completely disappeared after 2 weeks of Met treatment. These zebrafish transgenic lines show the complete testis specificity of inducible male sterility after Met treatment and reveal a period of the Ntr/Met ablation activity just prior to formation of the definitive adult spermatogonial cell population. This study demonstrates that combined genetic and pharmacological methods for developing an "infertile breeding technology" have practical application in controlling genetically modified (GM) fish breeding and meet the standards of biological and environment safety for other GM species.
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Affiliation(s)
- Chia-Chun Hsu
- Department of Radiology, Tri-Service General Hospital, 325, Cheng-Kung Road Sec. 2, Taipei 114, Taiwan, Republic of China
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27
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Shieh YS, Chang YS, Hong JR, Chen LJ, Jou LK, Hsu CC, Her GM. Increase of hepatic fat accumulation by liver specific expression of Hepatitis B virus X protein in zebrafish. Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1801:721-30. [PMID: 20416398 DOI: 10.1016/j.bbalip.2010.04.008] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 03/25/2010] [Accepted: 04/12/2010] [Indexed: 02/06/2023]
Abstract
The pathogenesis of fatty liver disease remains largely unknown. Here, we assessed the importance of hepatic fat accumulation on the progression of hepatitis in zebrafish by liver specific expression of Hepatitis B virus X protein (HBx). Transgenic zebrafish lines, GBXs, which selectively express the GBx transgene (GFP-fused HBx gene) in liver, were established. GBX Liver phenotypes were evaluated by histopathology and molecular analysis of fatty acid (FA) metabolism-related genes expression. Most GBXs (66-81%) displayed obvious emaciation starting at 4 months old. Over 99% of the emaciated GBXs developed hepatic steatosis or steatohepatitis, which in turn led to liver hypoplasia. The liver histology of GBXs displayed steatosis, lobular inflammation, and balloon degeneration, similar to non-alcoholic steatohepatitis (NASH). Oil red O stain detected the accumulation of fatty droplets in GBXs. RT-PCR and Q-rt-PCR analysis revealed that GBx induced hepatic steatosis had significant increases in the expression of lipogenic genes, C/EBP-alpha, SREBP1, ChREBP and PPAR-gamma, which then activate key enzymes of the de novo FA synthesis, ACC1, FAS, SCD1, AGAPT, PAP and DGAT2. In addition, the steatohepatitic GBX liver progressed to liver degeneration and exhibited significant differential gene expression in apoptosis and stress. The GBX models exhibited both the genetic and functional factors involved in lipid accumulation and steatosis-associated liver injury. In addition, GBXs with transmissible NASH-like phenotypes provide a promising model for studying liver disease.
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Affiliation(s)
- Yun-Sheng Shieh
- Institute of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan
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28
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Chen PC, Wu JL, Her GM, Hong JR. Aquatic birnavirus induces necrotic cell death via the mitochondria-mediated caspase pathway. Fish Shellfish Immunol 2010; 28:344-353. [PMID: 19944168 DOI: 10.1016/j.fsi.2009.11.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Revised: 11/05/2009] [Accepted: 11/14/2009] [Indexed: 05/28/2023]
Abstract
Aquatic birnavirus induces necrotic cell death by an ill-understood process. Presently, we demonstrate that infectious pancreatic necrosis virus (IPNV) induces post-apoptotic necrotic cell death through loss of mitochondrial membrane potential (MMP) followed by caspase-3 activation in CHSE-214 cells. Progressive phosphatidylserine externalization was observed at 6 h post-infection (p.i.). This was followed by the development of bulb-like vesicles (bleb formation) at 8 h p.i. Progressive loss of MMP was also observed in IPNV-infected CHSE-214 cells beginning at 6 h p.i. At 8 h and 12 h p.i., IPNV-infected cells demonstrated a dramatic increase in MMP loss, rapid entry into necrotic cell death, and activation of caspase-9 and -3. Additionally, treatment with an inhibitor of MMP loss, bongkrekic acid, an adenine nucleotide translocase inhibitor, blocked IPNV-induced PS exposure and MMP loss, as well as reduced the activation of caspase-3. Taken together, our results suggest that IPNV induces apoptotic cell death via loss of MMP, thereby triggering secondary necrosis and caspases-3 activation. Furthermore, this death-signaling pathway is disrupted by bongkrekic acid in fish cells, indicating that this drug may serve to modulate IPNV-induced pathogenesis.
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Affiliation(s)
- Po-Chun Chen
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
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29
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Chen LJ, Su YC, Hong JR. Betanodavirus non-structural protein B1: A novel anti-necrotic death factor that modulates cell death in early replication cycle in fish cells. Virology 2009; 385:444-54. [PMID: 19136133 DOI: 10.1016/j.virol.2008.11.048] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Revised: 11/03/2008] [Accepted: 11/25/2008] [Indexed: 12/30/2022]
Abstract
The functions of the Betanodavirus non-structural protein B1 is still unknown. We examined B1 expression patterns and investigated novel cell death regulatory functions for this viral protein following RGNNV infection in fish cells. The B1 gene (336 nt) was cloned from the redspotted grouper nervous necrosis virus (RGNNV) genome. B1 mRNA was rapidly expressed in the fish cells from viral RNA3 at 12 h post-infection (p.i.). At the protein level, expression was low at 12 h p.i., and then increased rapidly between 24 h and 72 h p.i. In RGNNV-infected, B1-containing fish cells, over expression of RGNNV B1 reduced Annexin-V positive cells by 50% and 65% at 48 h and 72 h p.i., respectively, and decreased loss of mitochondrial membrane potential (MMP) by 20% and 70% at 48 h and 72 h p.i., respectively. Finally, B1 knockdown during RGNNV infection using anti-sense RNA increased necrotic cell death and reduced cell viability during the early replication cycle (24 h p.i.). Our results suggest that B1 is an early expression protein that has an anti-necrotic cell death function which reduces the MMP loss and enhances viral host cell viability. This finding provides new insights into RNA viral pathogenesis and disease control.
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Affiliation(s)
- Lei-Jia Chen
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology; National Cheng Kung University, Tainan 701, Taiwan
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30
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Su YC, Wu JL, Hong JR. Betanodavirus non-structural protein B2: A novel necrotic death factor that induces mitochondria-mediated cell death in fish cells. Virology 2008; 385:143-54. [PMID: 19116179 DOI: 10.1016/j.virol.2008.11.036] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Revised: 09/17/2008] [Accepted: 11/13/2008] [Indexed: 12/31/2022]
Abstract
The Betanodavirus non-structural protein B2 plays a role in silencing RNA interference (RNAi), which mediated regulation of animal and plant innate immune responses, but little is known regarding the role of B2 in cell death. The present study examined the effects of B2 on mitochondria-mediated necrotic cell death in grouper liver (GL-av) cells. B2 was expressed at 12 h post-infection (pi), with increased expression between 24 and 72 h pi by Western blot. B2 was transiently expressed to investigate possible novel protein functions. Transient expression of B2 in GL-av cells resulted in apoptotic cell features and positive TUNEL assays (28%) at 24 h post-transfection (pt). During mechanistic studies of cell death, B2 upregulated expression of the proapoptotic gene Bax (2.8 fold at 48 h pt) and induced loss of mitochondria membrane potential (MMP) but not mitochondrial cytochrome c release. Furthermore, over expression of Bcl-2 family member zfBcl-xL effectively prevented B2-induced, mitochondria-mediated necrotic cell death. Finally, using RNA interference to reduce B2 expression, both B2 and Bax expression were downregulated and RGNNV-infected cells were rescued from secondary necrosis. Taken together, our results suggest that B2 upregulates Bax and triggers mitochondria-mediated necrotic cell death independent of cytochrome c release.
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Affiliation(s)
- Yu-Chin Su
- Institute of Biotechnology, National Cheng Kung University, Taiwan, ROC
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31
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Chen LJ, Hsu CC, Hong JR, Jou LK, Tseng HC, Wu JL, Liou YC, Her GM. Liver-specific expression of p53-negative regulator mdm2 leads to growth retardation and fragile liver in zebrafish. Dev Dyn 2008; 237:1070-81. [PMID: 18297734 DOI: 10.1002/dvdy.21477] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Tumorigenesis requires inactivation of the p53 tumor suppressor pathway, likely involving the negative regulator Mdm2 protein. To analyze the possible roles of Mdm2 in oncogenesis and other functions during zebrafish hepatogenesis, we generated transgenic zebrafish by liver-specific Mdm2 over-expression utilizing a fusion between genes encoding GFP and mdm2, GFP::Mdm2. Over-expression of GFP::Mdm2 in the zebrafish liver did not interrupt normal liver development in the larval stages but approximately 30% of the adult fish raised from the same larvae displayed obvious growth retardation at 16 weeks of age. Most growth-retarded adults displayed liver atrophy, contraction, or hypoplasia, which proved lethal within 4 to 8 months. Histologically, over-expression of GFP::Mdm2 in Gmdm2-liver leading to liver degeneration may in some way have been due to an increased cell apoptosis accompanied by a slightly interrupted cell cycle or hepatocyte proliferation. Liver degeneration or other transgenic phenotypes were not associated with liver cancer; however, liver-degenerated phenotypes could be passed to wild-type zebrafish. In this study, we generated transgenic zebrafish lines with a "fragile liver." The "fragile liver" zebrafish can provide a model for molecular pathology of liver diseases and for screening small molecules that affect mdm2-related pathways.
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Affiliation(s)
- Li-Je Chen
- Institute of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan
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32
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Wu HC, Chiu CS, Wu JL, Gong HY, Chen MC, Lu MW, Hong JR. Zebrafish anti-apoptotic protein zfBcl-xL can block betanodavirus protein alpha-induced mitochondria-mediated secondary necrosis cell death. Fish Shellfish Immunol 2008; 24:436-449. [PMID: 18276161 DOI: 10.1016/j.fsi.2008.01.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2007] [Revised: 12/18/2007] [Accepted: 01/02/2008] [Indexed: 05/25/2023]
Abstract
Betanodavirus protein alpha induces cell apoptosis or secondary necrosis by a poorly understood process. In the present work, red spotted grouper nervous necrosis virus (RGNNV) RNA 2 was cloned and transfected into tissue culture cells (GF-1) which then underwent apoptosis or post-apoptotic necrosis. In the early apoptotic stage, progressive phosphatidylserine externalization was evident at 24h post-transfection (p.t.) by Annexin V-FLUOS staining. TUNEL assay revealed apoptotic cells at 24-72 h p.t, after which post-apoptotic necrotic cells were identified by acridine orange/ethidium bromide dual dye staining from 48 to 72 h p.t. Protein alpha induced progressive loss of mitochondrial membrane potential (MMP) which was detected in RNA2-transfected GF-1 cells at 24, 48, and 72 h p.t., which correlated with cytochrome c release, especially at 72 h p.t. To assess the effect of zfBcl-xL on cell death, RNA2-transfected cells were co-transfected with zfBcl-x(L). Co-transfection of GF-1 cells prevented loss of MMP at 24 h and 48 h p.t. and blocked initiator caspase-8 and effector caspase-3 activation at 48 h p.t. We conclude that RGNNV protein alpha induces apoptosis followed by secondary necrotic cell death through a mitochondria-mediated death pathway and activation of caspases-8 and -3.
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Affiliation(s)
- Horng-Cherng Wu
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng-Kung University, Tainan 701, Taiwan
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33
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Lu MW, Chao YM, Guo TC, Santi N, Evensen O, Kasani SK, Hong JR, Wu JL. The interferon response is involved in nervous necrosis virus acute and persistent infection in zebrafish infection model. Mol Immunol 2007; 45:1146-52. [PMID: 17727953 DOI: 10.1016/j.molimm.2007.07.018] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Revised: 07/12/2007] [Accepted: 07/18/2007] [Indexed: 10/22/2022]
Abstract
Betanodavirus, a small positive-sense bipartite RNA virus notoriously affecting marine aquaculture worldwide has been extensively studied in vitro. However, impending studies in elucidating virus-host interactions have been limiting due to the lack of appropriate animal disease models. Therefore, in this study, we have attempted to successfully establish NNV infection in zebrafish (Danio rerio) showing typical NNV symptoms and which could potentially serve as an in vivo model for studying virus pathogenesis. Zebrafish being already a powerful research tool in developmental biology and having its genome completely sequenced by the end of 2007 would expedite NNV research. We have observed viral titers peaked at 3 days post-infection and histological study showing lesions in brain tissues similar to natural host infection. Further, we used this infection model to study the acute and persistence infection during NNV infection. Interestingly, RT-PCR and immunoblotting assays revealed that the acute infection in larvae and juveniles is largely due to inactive interferon response as opposed to activated innate immune response during persistent infection in adult stage. This study is the first to demonstrate NNV infection of zebrafish, which could serve as a potential animal model to study virus pathogenesis and neuron degeneration research.
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Affiliation(s)
- Ming-Wei Lu
- Laboratory of Marine Molecular Biology and Biotechnology, Institute of Cellular & Organismic Biology, Academia Sinica, Nankang, Taipei 115, Taiwan
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34
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Chen SP, Wu JL, Su YC, Hong JR. Anti-Bcl-2 family members, zfBcl-x(L) and zfMcl-1a, prevent cytochrome c release from cells undergoing betanodavirus-induced secondary necrotic cell death. Apoptosis 2007; 12:1043-60. [PMID: 17245642 DOI: 10.1007/s10495-006-0032-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Nervous necrosis virus (NNV)-induced, host cell apoptosis mediates secondary necrosis by an ill-understood process. In this study, redspotted grouper nervous necrosis virus (RGNNV) is shown to induce mitochondria-mediated necrotic cell death in GL-av cells (fish cells) via cytochrome c release, and anti-apoptotic proteins are shown to protect these cells from death. Western blots revealed that cytochrome c release coincided with disruption of mitochondrial ultrastructure and preceded necrosis, but did not correlate with caspases activation. To identify the mediator(s) of this necrotic process, a protein synthesis inhibitor (cycloheximide; CHX; 0.33 microg/ml) was used to block cytochrome c release as well as PS exposure and mitochondrial membrane permeability transition pore (MMP) loss. CHX (0.33 microg/ml) completely blocked viral protein B2 expression, and partly blocked protein A, protein alpha, and a pro-apoptotic death protein (Bad) expression. Overexpression of B2 gene increased necrotic-like cell death up to 30% at 48 h post-transfection, suggesting that newly synthesized protein (B2) may be involved in this necrotic process. Finally, necrotic death was prevented by overexpression of Bcl-2 family proteins, zfBcl-x(L) and xfMcl-1a. Thus, new protein synthesis and release of cytochrome c are required for RGNNV-induced necrotic cell death, which can be blocked by anti-apoptotic Bcl-2 members.
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Affiliation(s)
- Shi-Ping Chen
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
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35
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Her GM, Cheng CH, Hong JR, Sundaram GS, Wu JL. Imbalance in liver homeostasis leading to hyperplasia by overexpressing either one of the Bcl-2-related genes, zfBLP1 and zfMcl-1a. Dev Dyn 2006; 235:515-23. [PMID: 16273521 DOI: 10.1002/dvdy.20624] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Apoptosis is an essential part of normal embryonic development in vertebrates, and it is involved in sculpturing organs and controlling cell populations. In previous studies, we identified two novel proteins, zfBLP1 and zfMcl-1a, which are similar to those of the Bcl-2 family as a group of evolutionarily conserved proteins that regulate cellular anti-apoptosis. To evaluate the effect of dysregulated hepatocyte apoptosis during zebrafish hepatogenesis, we demonstrate the transgenic overexpression of either zfBLP1 or zfMcl-1a in zebrafish larval liver. Results showed that 18%-43% of larvae overexpressed zfBLP1 and that 16%-37% of larvae overexpressed zfMc1-1a in the liver leading to liver hyperplasia in 5-day postfertilization (dpf) zebrafish larvae. Histologically, zebrafish larvae exhibiting liver hyperplasia displayed a normal type of hepatocyte and the same cell numbers in their two liver buds compared with only one liver bud of wild-type larvae. Of interest, the expression of cyclin genes (A2, B, D1, and E), hepatocyte nuclear factor genes (HNF-1alpha, beta, -3beta, and 4alpha), and oncogenic markers (P53, c-myc, beta-catenin, N-ras, and gankyrin) were up-regulated, while the expression of C/EBP-alpha was down-regulated in a zfMcl-1a-mediated anti-apoptotic process of the liver. Increased cell death and proliferation was found in both hepatic cells of zebrafish larvae overexpressing either zfBLP1 or zfMcl-1a. However, those zebrafish larvae with liver hyperplasia only lived approximately 10 days. (This finding may have been due to liver abnormalities that led to failure of liver function.) In conclusion, transgenic overexpression of zfBLP1 or zfMcl-1a in zebrafish larvae interrupts regulation of the homeostatic balance between cell proliferation and programmed cell death during hepatogenesis and leads to liver hyperplasia.
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Affiliation(s)
- Guor Mour Her
- Institute of Bioscience and Biotechnology, National Taiwan Ocean University, Keelung, Taiwan.
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36
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Chen SP, Yang HL, Her GM, Lin HY, Jeng MF, Wu JL, Hong JR. Betanodavirus induces phosphatidylserine exposure and loss of mitochondrial membrane potential in secondary necrotic cells, both of which are blocked by bongkrekic acid. Virology 2006; 347:379-91. [PMID: 16430940 DOI: 10.1016/j.virol.2005.11.052] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2005] [Revised: 09/27/2005] [Accepted: 11/29/2005] [Indexed: 01/02/2023]
Abstract
In this study, we show how the red spotted grouper nervous necrosis virus (RGNNV) causes loss of mitochondrial membrane potential and promotes host secondary apoptotic necrosis. RGNNV viral proteins such as protein alpha (42 kDa) and protein A (110 kDa) were quickly expressed between 12 h and 24 h postinfection (p.i.) in GL-av cells. Annexin V staining revealed that the NNV infection of GL-av cells induced phosphatidylserine (PS) externalization and development of bulb-like vesicles (bleb formation) at 24 h p.i. NNV infection also induced DNA fragmentation detectable by TUNEL assay between 12 h (8%) and 72 h (32%) p.i. Bongkrekic acid (1.6 microM; BKA) blocked permeability of the mitochondrial permeability transition pore, but cyclosporine A (CsA) did not block secondary necrosis. Finally, secondary necrotic cells were not engulfed by neighboring cells. Our data suggest that RGNNV induces apoptotic death via opening the mitochondrial permeability transition pore thereby triggering secondary necrosis in the mid-apoptotic phase.
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Affiliation(s)
- Shi-Ping Chen
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng-Kung University, Tainan 701, Taiwan, ROC
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Santi N, Sandtrø A, Sindre H, Song H, Hong JR, Thu B, Wu JL, Vakharia VN, Evensen Ø. Infectious pancreatic necrosis virus induces apoptosis in vitro and in vivo independent of VP5 expression. Virology 2005; 342:13-25. [PMID: 16126243 DOI: 10.1016/j.virol.2005.07.028] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2005] [Revised: 04/25/2005] [Accepted: 07/14/2005] [Indexed: 11/20/2022]
Abstract
Infectious pancreatic necrosis virus (IPNV), the causative agent of a highly infectious disease in salmonid fish, encodes a small non-structural protein designated VP5. This protein contains Bcl-2 homologous domains and inhibits apoptosis when expressed in cell culture. We have previously reported the generation of three VP5 mutants of IPNV-Sp serotype, using reverse genetics (Santi, N., Song, H., Vakharia, V.N., Evensen, Ø., 2005. Infectious pancreatic necrosis virus VP5 is dispensable for virulence and persistence. J. Virol. 79 (14), 9206-9216). The wild-type rNVI15 virus encodes a truncated 12-kDa VP5 protein, rNVI15-15K encodes a full-length 15-kDa VP5, whereas rNVI15-DeltaVP5 is deficient in VP5 expression. In the present report, the role of VP5 in apoptosis was assessed both in vitro and in vivo, using the recombinant IPNV strains. Apoptosis was observed in hepatocytes of Atlantic salmon post-smolts challenged with all three VP5 mutant viruses. Using a double-labeling technique to detect apoptotic cells and IPNV antigens, we found that viral antigen and apoptotic cells co-distributed. In addition, numerous double-positive cells were seen. The recombinant viruses also induced apoptosis in infected cell cultures, and the morphology and membrane integrity of infected cells at different time points was similar. In summary, these results indicate that IPNV induces apoptosis in infected cell cultures and in fish, independent of VP5 expression. However, substitutions of putative functionally important amino acids in the BH2 domain of VP5 of IPNV-Sp strains were identified, which might influence the anti-apoptosis effect of the protein, and partly explain the apparent absence of this specific function.
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Affiliation(s)
- Nina Santi
- Section for Pathology, National Veterinary Institute, 0033 Oslo, Norway
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Hong JR, Lin GH, Lin CJF, Wang WP, Lee CC, Lin TL, Wu JL. Phosphatidylserine receptor is required for the engulfment of dead apoptotic cells and for normal embryonic development in zebrafish. Development 2004; 131:5417-27. [PMID: 15469976 DOI: 10.1242/dev.01409] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
During development, the role of the phosphatidylserine receptor (PSR) in the removal of apoptotic cells that have died is poorly understood. We have investigated this role of PSR in developing zebrafish. Programmed cell death began during the shield stage, with dead cells being engulfed by a neighboring cell that showed a normal-looking nucleus and the nuclear condensation multi-micronuclei of an apoptotic cell. The zebrafish PSR engulfing receptor was cloned (zfpsr), and its nucleotide sequence was compared with corresponding sequences in Drosophila melanogaster (76% identity), human (74%), mouse (72%) and Caenorhabditis elegans (60%). The PSR receptor contained a jmjC domain (residues 143-206) that is a member of the cupin metalloenzyme superfamily, but in this case serves an as yet unknown function(s). psr knockdown by a PSR morpholino oligonucleotide led to accumulation of a large number of dead apoptotic cells in whole early embryo. These cells interfered with embryonic cell migration. In addition, normal development of the somite, brain, heart and notochord was sequentially disrupted up to 24 hours post-fertilization. Development could be rescued in defective embryos by injecting psr mRNA. These results are consistent with a PSR-dependent system in zebrafish embryos that engulfs apoptotic cells mediated by PSR-phagocytes during development, with the system assuming an important role in the normal development of tissues such as the brain, heart, notochord and somite.
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MESH Headings
- Amino Acid Sequence
- Animals
- Apoptosis
- Cell Movement
- Cloning, Molecular
- Embryo, Nonmammalian/cytology
- Embryo, Nonmammalian/embryology
- Embryo, Nonmammalian/metabolism
- Embryonic Development
- Gene Expression Profiling
- Gene Expression Regulation, Developmental
- Humans
- Jumonji Domain-Containing Histone Demethylases
- Microscopy, Electron
- Molecular Sequence Data
- Organogenesis
- Phenotype
- Protein Structure, Tertiary
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Cell Surface/chemistry
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Sequence Alignment
- Time Factors
- Zebrafish/embryology
- Zebrafish/genetics
- Zebrafish/metabolism
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Affiliation(s)
- Jiann-Ruey Hong
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng-Kung University, Tainan 701, Taiwan
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39
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Abstract
VP5, a 5'-terminal, small open reading frame in segment A of the aquatic birnavirus (infectious pancreatic necrosis virus, IPNV) genome, encodes a 17-kDa nonstructural protein. We previously reported apoptosis induced by IPNV in a fish cell line. In the present study, we cloned and identified VP5 and tested its function. Comparisons of the amino acid sequence of VP5 with well-known Bcl-2 family member proteins showed that the VP5 protein contains Bcl-2 homology (BH) domains BH1, BH2, BH3, and BH4 but without the transmembrane region. VP5-stable clones enhanced viability, prevented membrane blebbing, delayed DNA internucleosomal cleavage, and decreased virus titer during IPNV infection but, when deleted, BH domains 1 and 2 could lose the preventable ability. In addition, VP5 was demonstrated to be able to enhance or assist in maintaining the functional half-life of survival factor Mcl-1 and regulate specific viral protein expression during the early replication cycle. Finally, we found that VP5 was capable of enhancing cell viability when cells were exposed to UV irradiation. In summary, these results suggest that the aquatic birnavirus may utilize a notable strategy via VP5 to regulate the host apoptosis-off system for enhancing progeny production.
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Affiliation(s)
- Jiann-Ruey Hong
- Laboratory of Marine Molecular Biology and Biotechnology, Institute of Zoology, Academia Sinica, Nankang, Taipei 115, Taiwan, ROC
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Chen MC, Gong HY, Cheng CY, Wang JP, Hong JR, Wu JL. Cloning and characterization of zfBLP1, a Bcl-XL homologue from the zebrafish, Danio rerio. Biochim Biophys Acta 2001; 1519:127-33. [PMID: 11406282 DOI: 10.1016/s0167-4781(01)00209-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The importance of the Bcl-2 family proteins in normal vertebrate embryogenesis is being recognized; however, their regulatory mechanism is poorly understood. We report here the cloning and characterization of a novel zebrafish Bcl-2 family protein, zfBLP1. The zfBLP1 cDNA is 1942 nucleotides long, encoding a polypeptide of 238 amino acids. The primary sequence of zfBLP1 shares 50% identity to human Bcl-XL, and contains all four conserved BH domains of the Bcl-2 family proteins. Primary sequence analysis identified a consensus ER retention signal at the C-terminal end of zfBLP1. Northern blot analysis indicated that there were two major and two minor zfBLP1 mRNA species expressed during embryonic development. Among the two major mRNA species, the short one, approx. 3 kb in size, was expressed throughout embryonic development, while the long one, approx. 7 kb long, was not detectable until the gastrula stage. These results suggest that zfBLP1 is a novel Bcl-2 family protein under complicated regulations, and is likely to play an important role in zebrafish oogenesis and embryogenesis.
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Affiliation(s)
- M C Chen
- Laboratory of Marine Molecular Biology and Biotechnology, Institute of Zoology, Academia Sinica, Taipei, Taiwan
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Chen MC, Gong HY, Cheng CY, Wang JP, Hong JR, Wu JL. Cloning and characterization of a novel nuclear Bcl-2 family protein, zfMcl-1a, in zebrafish embryo. Biochem Biophys Res Commun 2000; 279:725-31. [PMID: 11118352 DOI: 10.1006/bbrc.2000.3977] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The importance of the Bcl-2 family proteins in normal vertebrate embryogenesis is being recognized; however, their regulatory mechanism is poorly understood. To elucidate the embryonic roles of Bcl-2 family proteins, we cloned and characterized the first zebrafish Bcl-2 family protein, zfMcl-1a. Zebrafish Mcl-1a shows the highest homology to rat Mcl-1 and contains several conserved BH domains of the Bcl-2 family proteins. It also contains a nuclear localization signal (NLS). Using EGFP reporter analysis, we verified the nuclear localization of zfMcl-1a. Deletion of the NLS resulted in distribution of the fusion protein in the cytoplasm. Northern blot analysis indicated that zfMcl-1a mRNA is 1.5 kb and was expressed in oocytes and throughout embryonic development. Notably, the expression of zfMcl-1a transcript was significantly downregulated during gastrulation. These results suggest that zfMcl-1a is a novel nuclear Bcl-2 family protein and is likely to play an important role in zebrafish oogenesis and embryogenesis.
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Affiliation(s)
- M C Chen
- Laboratory of Marine Molecular Biology and Biotechnology, Institute of Zoology, Taipei, Taiwan, 115, Republic of China
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42
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Hong JR, Hsu YL, Wu JL. Infectious pancreatic necrosis virus induces apoptosis due to down-regulation of survival factor MCL-1 protein expression in a fish cell line. Virus Res 1999; 63:75-83. [PMID: 10509718 DOI: 10.1016/s0168-1702(99)00060-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Infectious pancreatic necrosis virus (IPNV), a member of the virus family Birnaviridae, causes an acute, contagious disease in a number of economically important fish species. CHSE-214, a Chinook salmon embryonic cell line, when infected by IPNV showed morphological and biochemical features of apoptosis, including an intense DNA laddering pattern and blebbing of the plasma membrane, followed by formation of apoptotic bodies. The Mcl-1 gene product proved to be a member of the Bcl-2 gene family, and like Bcl-2 had the capacity to promote cell viability. Here, we investigated the pattern of expression of Mcl-1 in CHSE-214 cells infected by IPNV. We found that the Mcl-1 level decreased markedly in cells undergoing apoptosis after IPNV infection. This decrease was rapid during the first 8 h postinfection and preceded cell death. Furthermore, we found that drugs including cycloheximide, genistein and EDTA either prevented the decline in Mcl-1 levels or blocked the intense DNA laddering pattern. Other drugs like serine proteinase inhibitor, 400 microg/ml aprotinin, 400 microg/ml leupeptin and 100 microg/ml tryphostin did not. The virus gene expression pattern was examined by Western blot using antivirion polyclonal antibody and was blocked during treatment with cycloheximide, genistein and EDTA but not by serine proteinase, aprotinin, leupeptin or tryphostin. Together the data showed a striking correlation between virus replication and Mcl-1 expression in CHSE-214 cells, suggesting that the virus gene expression has a possible involvement with Mcl-1 in the regulation of apoptosis in these cells.
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Affiliation(s)
- J R Hong
- Laboratory of Marine Molecular Biology and Biotechnology, Institute of Zoology, Academia Sinica, Nankang, Taipei, Taiwan, ROC
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Hong JR, Lin TL, Yang JY, Hsu YL, Wu JL. Dynamics of nontypical apoptotic morphological changes visualized by green fluorescent protein in living cells with infectious pancreatic necrosis virus infection. J Virol 1999; 73:5056-63. [PMID: 10233968 PMCID: PMC112550 DOI: 10.1128/jvi.73.6.5056-5063.1999] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Morphologically, apoptotic cells are characterized by highly condensed membrane blebbing and formation of apoptotic bodies. Recently, we reported that apoptosis precedes necrosis in a fish cell line infected with infectious pancreatic necrosis virus (IPNV). In the present study, we tested the possibility that nontypical apoptosis is a component of IPNV-induced fish cell death. A variant type of green fluorescent protein (EGFP) was expressed in a fish cell line such that EGFP served as a protein marker for visualizing dynamic apoptotic cell morphological changes and for tracing membrane integrity changes during IPNV infection. Direct morphological changes were visualized by fluorescence microscopy by EGFP in living cells infected with IPNV. The nontypical apoptotic morphological change stage occurred during the pre-late stage (6 to 7 h postinfection). Nontypical apoptotic features, including highly condensed membrane blebbing, occurred during the middle apoptotic stage. At the pre-late apoptotic stage, membrane vesicles quickly formed, blebbed, and were finally pinched off from the cell membrane. At the same time, at this pre-late apoptotic stage, apoptotic cells formed unique small holes in their membranes that ranged from 0.39 to 0.78 micrometer according to examination by scanning electron microscopy and immunoelectron microscopy. Quantitation of the intra- and extracellular release of EGFP by CHSE-214-EGFP cells after IPNV infection was done by Western blotting and fluorometry. Membrane integrity was quickly lost during the late apoptotic stage (after 8 h postinfection), and morphological change and membrane integrity loss could be prevented and blocked by treatment with apoptosis inhibitors such as cycloheximide, genistein, and EDTA before IPNV infection. Together, these findings show the apoptotic features at the onset of pathology in host cells (early and middle apoptotic stages), followed secondarily by nontypical apoptosis (pre-late apoptotic stage) and then by postapoptotic necrosis (late apoptotic stage), of a fish cell line. Our results demonstrate that nontypical apoptosis is a component of IPNV-induced fish cell death.
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Affiliation(s)
- J R Hong
- Laboratory of Marine Molecular Biology and Biotechnology, Institute of Zoology, Academia Sinica, Nankang, Taipei 115, Taiwan, Republic of China
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44
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Huang CY, Zeng LF, He T, Wang CJ, Hong JR, Zhang XQ, Hou YH, Peng SS. In vivo and in vitro studies on the antitumor activities of MCP (Malva crispa L. Powder). Biomed Environ Sci 1998; 11:297-306. [PMID: 10095926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Four short-term in vivo and in vitro tests were used to further confirm the antitumor activities of MCP, a vegetable powder, prepared from Malva crispa L. (i) In the H22 hepatoma-transplanting test, MCP had antitumor action, but MCP residue did not show such action; 5-FU appeared to have more potent antitumor activities and more harmful effects than MCP. (ii) In the micronucleus (MN) test, MCP significantly decreased MN frequency. (iii) In the cancer cell culture systems, the MCP fat-soluble extract revealed inhibitory effects on the growth and proliferation of the human hepatoma and the gastric cancer cells in a dose-response manner. (iv) In the colony formation test, MCP also altered the morphology of human gastric cancer cells. It was suggested that MCP could be consumed not only by healthy subjects for cancer prevention but also by patients with cancer as supplementary treatment in combination with anticarcinogenic drug such as 5-FU, cyclophosphamide (CP).
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Affiliation(s)
- C Y Huang
- Department of Nutrition and Food Hygiene, School of Public Health, West China University of Medical Sciences (WCUMS), Chengdu, China
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45
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Abstract
The current view of infectious pancreatic necrosis virus (IPNV) infection includes a necrotic process that relies primarily on the histological appearance of tissue after the degenerative process. We tested this view by examining the possibility that apoptosis is a component of double-stranded RNA virus (IPNV) that induces fish embryonic cell death. Four kinds of assays for apoptosis were used in analyzing IPNV-infected CHSE-214 cells: (1) assay with terminal deoxynucleotidyl transferase (TdT)-mediated end-labeling of DNA in nuclei of intact cells during virus infection, (2) assay for procoagulant activity, (3) assay for DNA ladders, and (4) electron microscopic assays for the ultrastructural changes in characteristic apoptotic cells. In all p.i. samples, both low and high m.o.i. groups contained apoptotic nuclei, according to TdT-mediated dUTP labeling of intact cells, but in control CHSE-214 cells, apoptotic nuclei were rare at all levels of incubation sampled by TdT-mediated dUTP labeling. Prenecrotic or postnecrotic cells were found to express phosphatidylserine on the surface by annexin V-FITC labeling, but normal cells did not. DNAs from both 4 h p.i. of high m.o.i. and 8 h p.i. of low m.o.i. were found to be cleaved into fragments indicative of preferential cleavage at internucleosomal sites. The IPNV-infected CHSE-214 cells were analyzed with an electron microscope and showed a pattern of ultrastructural change, indicating that apoptosis appears before pathological changes of necrosis, including condensed chromatin, fragmented nuclei, nuclei with chromatin marginations, and secondary necrosis from prenecrotic cells in IPNV-infected CHSE-214 cells. Together, these findings show that apoptosis precedes any detectable necrotic change in CHSE-214 cells that is currently viewed as necrosis. Thus, apoptosis characterizes the onset of pathology in host cells and is followed by necrotic processes.
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Affiliation(s)
- J R Hong
- Institute of Zoology, Academia Sinica, Nankang, Taipei, 115, Taiwan
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Wu JL, Hong JR, Chang CY, Hui CF, Liao CF, Hsu YL. Involvement of serine proteinase in infectious pancreatic necrosis virus capsid protein maturation and NS proteinase cleavage in CHSE-214 cells. J Fish Dis 1998; 21:215-220. [PMID: 21361976 DOI: 10.1046/j.1365-2761.1998.00097.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
An investigation of virus-specific protein maturation in infectious pancreatic necrosis virus (IPNV) infected Chinook salmon embryo cells (CHSE-214) was undertaken. The precursor protein (pVP2-1) of the major mature capsid protein (VP2) was processed sequentially from pVP2-1 to pVP2-2 and VP2. Experiments using serine proteinase inhibitors showed that the maturation of the VP2 was blocked in the pVP2-1 post-translational cleavage steps. A protinin, a potent proteinase inhibitor, at 800 μg ml(-1) blocked pVP2-2 to VP2 and the cleavage of VP4 (28 kDa) to VP4-1 (25 kDa). Therefore, our data showed that the maturation of the capsid protein (VP2) and cleavage of VP4 (NS proteinase) can be blocked by serine proteinase inhibitors.
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Affiliation(s)
- J L Wu
- 1 Molecular Biology Laboratory, Institute of Zoology, Academia Sinica, Nankang, Taipei, Taiwan, 2 Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
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Abstract
The authors report the case of bilateral gonadoblastomas in a phenotypic female, with a 46,XY karyotype, with campomelic dysplasia. Although campomelic dysplasia with gonadal dysgenesis should be expected to contribute to an increased risk of gonadoblastoma, this is the first documented case report of campomelic dysplasia and gonadoblastoma. Phenotypic females with campomelic dysplasia should be karyotyped once the skeletal dysplasia is recognized. phenotypic females with campomelic dysplasia should undergo gonadectomy if their karyotype includes a Y chromosome or fragment.
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Affiliation(s)
- J R Hong
- Department of Surgery, Alfred I duPont Institute, Wilmington, DE 19899, USA
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48
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Abstract
To understand some of the factors involved in weaning and growth faltering in rural China, a cross-sectional positive deviance study was undertaken among 389 rural 4-12-month-old infants from two townships of a county in Sichuan. The infants' mothers were interviewed about their child-feeding practices and other sociodemographic information, and anthropometric measurements were made on their infants. Positive deviant infants (those growing adequately in environments in which the majority of the children suffer from growth retardation and malnutrition) were identified from the Chinese WAZ-scores calculated from the anthropometric measurements. Feeding practices found to be associated with the better growth of the positive deviant infants included breastfeeding through age 12 months, feeding soybean milk, liver and pork blood products on a more than weekly basis during the ages of 7-9 months, not feeding rice flour (mifen) before age 7 months, and not giving supplements or tonics. Mothers' nutrition knowledge was also associated with positive deviance status. The relevance of the findings is discussed with respect to designing nutrition education interventions for rural Sichuan.
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Affiliation(s)
- G S Guldan
- Tufts University School of Nutrition, Medford, MA 02155
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