1
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Liu DH, Li F, Yang RZ, Wu Z, Meng XY, Li SM, Li WX, Li JK, Wang DD, Wang RY, Li SA, Liu PP, Kang JS. Pulmonary mitochondrial DNA release and activation of the cGAS-STING pathway in Lethal Stx12 knockout mice. Cell Commun Signal 2025; 23:174. [PMID: 40200300 PMCID: PMC11980072 DOI: 10.1186/s12964-025-02141-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2024] [Accepted: 03/07/2025] [Indexed: 04/10/2025] Open
Abstract
STX12 (syntaxin12 or syntaxin13), a member of the SNARE protein family, plays a crucial role in intracellular vesicle transport and membrane fusion. Our previous research demonstrated that Stx12 knockout mice exhibit perinatal lethality with iron deficiency anemia. Despite its importance, the comprehensive physiological and pathological mechanism of STX12 remains largely unknown. Here, we revealed that STX12 deficiency causes the depolarization of mitochondrial membrane potential in zebrafish embryos and mouse embryonic fibroblasts. Additionally, the loss of STX12 decreased the levels of mitochondrial complex subunits, accompanied by mitochondrial DNA (mtDNA) release and activated cGAS-STING pathway and Type I interferon pathway in the lung tissue of Stx12-/- mice. Additionally, we observed a substantial increase in cytokines and neutrophil infiltration within the lung tissues of Stx12 knockout mice, indicating severe inflammation, which could be a contributing factor for Stx12-/- mortality. Various interventions have failed to rescue the lethal phenotype, suggesting that systemic effects may contribute to lethality. Further research is warranted to elucidate potential intervention strategies. Overall, our findings uncover the critical role of STX12 in maintaining mitochondrial function and mtDNA stability in pulmonary cells, and reveal that STX12 depletion results in pulmonary mtDNA release and activates mtDNA-dependent innate immunity.
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Affiliation(s)
- Dan-Hua Liu
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- The First Clinical College, Zhengzhou University, Zhengzhou, China
| | - Fang Li
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Run-Zhou Yang
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Zhuanbin Wu
- Shanghai Model Organisms Center, Inc., Shanghai, China
| | - Xiao-Yan Meng
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- The First Clinical College, Zhengzhou University, Zhengzhou, China
| | - Sen-Miao Li
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- The First Clinical College, Zhengzhou University, Zhengzhou, China
| | - Wen-Xiu Li
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- The First Clinical College, Zhengzhou University, Zhengzhou, China
| | - Jia-Kang Li
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- The First Clinical College, Zhengzhou University, Zhengzhou, China
| | - Dian-Dian Wang
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- The First Clinical College, Zhengzhou University, Zhengzhou, China
| | - Rui-Yu Wang
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- The First Clinical College, Zhengzhou University, Zhengzhou, China
| | - Shu-Ang Li
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Pei-Pei Liu
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Jian-Sheng Kang
- Clinical Systems Biology Laboratories, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
- The First Clinical College, Zhengzhou University, Zhengzhou, China.
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2
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Duszyc K, von Pein JB, Ramnath D, Currin-Ross D, Verma S, Lim F, Sweet MJ, Schroder K, Yap AS. Apical extrusion prevents apoptosis from activating an acute inflammatory program in epithelia. Dev Cell 2023; 58:2235-2248.e6. [PMID: 37647898 DOI: 10.1016/j.devcel.2023.08.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 06/20/2023] [Accepted: 08/07/2023] [Indexed: 09/01/2023]
Abstract
Apoptosis is traditionally considered to be an immunologically silent form of cell death. Multiple mechanisms exist to ensure that apoptosis does not stimulate the immune system to cause inflammation or autoimmunity. Against this expectation, we now report that epithelia are programmed to provoke, rather than suppress, inflammation in response to apoptosis. We found that an acute inflammatory response led by neutrophils occurs in zebrafish and cell culture when apoptotic epithelial cells cannot be expelled from the monolayer by apical extrusion. This reflects an intrinsic circuit where ATP released from apoptotic cells stimulates epithelial cells in the immediate vicinity to produce interleukin-8 (IL-8). Apical extrusion therefore prevents inappropriate epithelial inflammation by physically eliminating apoptotic cells before they can activate this pro-inflammatory circuit. This carries the implication that epithelia may be predisposed to inflammation, elicited by sporadic or induced apoptosis, if apical extrusion is compromised.
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Affiliation(s)
- Kinga Duszyc
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane 4072, Australia.
| | - Jessica B von Pein
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane 4072, Australia
| | - Divya Ramnath
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane 4072, Australia
| | - Denni Currin-Ross
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane 4072, Australia
| | - Suzie Verma
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane 4072, Australia
| | - Fayth Lim
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane 4072, Australia
| | - Matthew J Sweet
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane 4072, Australia
| | - Kate Schroder
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane 4072, Australia
| | - Alpha S Yap
- Division of Cell and Developmental Biology, Institute for Molecular Bioscience, The University of Queensland, Brisbane 4072, Australia.
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3
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Halimi R, Levin-Zaidman S, Levin-Salomon V, Bialik S, Kimchi A. Epiblast fragmentation by shedding—a novel mechanism to eliminate cells in post-implantation mouse embryos. Cell Death Differ 2022; 29:1255-1266. [DOI: 10.1038/s41418-021-00918-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 11/24/2021] [Accepted: 11/26/2021] [Indexed: 11/09/2022] Open
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4
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Bahmanpour S, Talaei Khozani T, Soleimani A, Zareifard N. Germ cell differentiation of mouse embryonic stem cells can be influenced by the culture medium. Biotech Histochem 2019; 95:210-218. [PMID: 31617423 DOI: 10.1080/10520295.2019.1665711] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Although embryonic stem (ES) cells can differentiate into germ cells, little is known about the influence of culture media on this process. We investigated the effect of two culture media on the capacity of ES cells to differentiate into germ cells using embryoid body (EB) and monolayer culture protocols. Germ cell differentiation was induced in mouse ES cells under four experimental conditions: EB/Dulbecco's modified Eagle's medium (EB/DMEM), EB/knockout Dulbecco's modified Eagle's medium (EB/KO-DMEM), monolayer/Dulbecco's modified Eagle's medium (monolayer/DMEM), and monolayer/knockout Dulbecco's modified Eagle's medium (monolayer/KO-DMEM). After incubation for 6 days, quantitative real-time polymerase chain reaction (qRT-PCR) was used to assess expression of the germ cell markers, Mvh, Oct4, Rec8, Scp1, Scp3 and Stra8. Also, Oct4 and Mvh expressions at the protein level were assessed using immunocytochemistry; we evaluated alkaline phosphatase activity in addition to cell number and viability. Germ cell-specific marker expression was increased significantly in cells differentiated in KO-DMEM for both EB and monolayer protocols; the highest level was in cultures using the EB protocol. The highest cell proliferation rate was observed using the monolayer/KO-DMEM protocol and the lowest using the EB/DMEM protocol. Generally, KO-DMEM exhibited the greatest impact on germ cell differentiation and cell proliferation. Optimization of germ cell differentiation of ES cells requires careful selection of culture medium.
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Affiliation(s)
- Soghra Bahmanpour
- Laboratory for Stem Cell Research, Department of Anatomical Sciences, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Tahereh Talaei Khozani
- Laboratory for Stem Cell Research, Department of Anatomical Sciences, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Azam Soleimani
- Laboratory for Stem Cell Research, Department of Anatomical Sciences, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Nehleh Zareifard
- Laboratory for Stem Cell Research, Department of Anatomical Sciences, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
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5
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Ke FFS, Vanyai HK, Cowan AD, Delbridge ARD, Whitehead L, Grabow S, Czabotar PE, Voss AK, Strasser A. Embryogenesis and Adult Life in the Absence of Intrinsic Apoptosis Effectors BAX, BAK, and BOK. Cell 2019; 173:1217-1230.e17. [PMID: 29775594 DOI: 10.1016/j.cell.2018.04.036] [Citation(s) in RCA: 135] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 01/31/2018] [Accepted: 04/25/2018] [Indexed: 12/01/2022]
Abstract
Intrinsic apoptosis, reliant on BAX and BAK, has been postulated to be fundamental for morphogenesis, but its precise contribution to this process has not been fully explored in mammals. Our structural analysis of BOK suggests close resemblance to BAX and BAK structures. Notably, Bok-/-Bax-/-Bak-/- animals exhibited more severe defects and died earlier than Bax-/-Bak-/- mice, implying that BOK has overlapping roles with BAX and BAK during developmental cell death. By analyzing Bok-/-Bax-/-Bak-/- triple-knockout mice whose cells are incapable of undergoing intrinsic apoptosis, we identified tissues that formed well without this process. We provide evidence that necroptosis, pyroptosis, or autophagy does not substantially substitute for the loss of apoptosis. Albeit very rare, unexpected attainment of adult Bok-/-Bax-/-Bak-/- mice suggests that morphogenesis can proceed entirely without apoptosis mediated by these proteins and possibly without cell death in general.
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Affiliation(s)
- Francine F S Ke
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia.
| | - Hannah K Vanyai
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Angus D Cowan
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Alex R D Delbridge
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Lachlan Whitehead
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | - Stephanie Grabow
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Peter E Czabotar
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Anne K Voss
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia.
| | - Andreas Strasser
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia.
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6
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Ishida K, Saito T, Mitsui T. Involvement of selective epithelial cell death in the formation of feather buds on a bioengineered skin. Dev Growth Differ 2019; 61:141-149. [PMID: 30675906 DOI: 10.1111/dgd.12593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 11/15/2018] [Accepted: 12/04/2018] [Indexed: 11/28/2022]
Abstract
Selective cell death by apoptosis plays important roles in organogenesis. Apoptotic cells are observed in the developmental and homeostatic processes of several ectodermal organs, such as hairs, feathers, and mammary glands. In chick feather development, apoptotic events have been observed during feather morphogenesis, but have not been investigated during early feather bud formation. Previously, we have reported a method for generating feather buds on a bioengineered skin from dissociated skin epithelial and mesenchymal cells in three-dimensional culture. During the development of the bioengineered skin, epithelial cavity formation by apoptosis was observed in the epithelial tissue. In this study, we examined the selective epithelial cell death during the bioengineered skin development. Histological analyses suggest that the selective epithelial cell death in the bioengineered skin was induced by caspase-3-related apoptosis. The formation of feather buds of the bioengineered skin was disturbed by the treatment with a pan-caspase inhibitor. The pan-caspase inhibitor treatment suppressed the rearrangement of the epithelial layer and the formation of dermal condensation, which are thought to be essential step to form feather buds. The suppression of the formation of feather buds on the pan-caspase inhibitor-treated skin was partially compensated by the addition of a GSK-3β inhibitor, which activates Wnt/β-catenin signaling. These results suggest that the epithelial cell death is involved in the formation of feather buds of the bioengineered skin. These observations also suggest that caspase activities and Wnt/β-catenin signaling may contribute to the formation of epithelial and mesenchymal components in the bioengineered skin.
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Affiliation(s)
- Kentaro Ishida
- Department of Physics and Mathematics, College of Science and Engineering, Aoyama Gakuin University, Kanagawa, Japan.,Department of Developmental Biology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Tetsuichiro Saito
- Department of Developmental Biology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Toshiyuki Mitsui
- Department of Physics and Mathematics, College of Science and Engineering, Aoyama Gakuin University, Kanagawa, Japan
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7
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Wang MS, Zhang RW, Su LY, Li Y, Peng MS, Liu HQ, Zeng L, Irwin DM, Du JL, Yao YG, Wu DD, Zhang YP. Positive selection rather than relaxation of functional constraint drives the evolution of vision during chicken domestication. Cell Res 2016; 26:556-73. [PMID: 27033669 PMCID: PMC4856766 DOI: 10.1038/cr.2016.44] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 01/18/2016] [Accepted: 02/22/2016] [Indexed: 01/05/2023] Open
Abstract
As noted by Darwin, chickens have the greatest phenotypic diversity of all birds, but an interesting evolutionary difference between domestic chickens and their wild ancestor, the Red Junglefowl, is their comparatively weaker vision. Existing theories suggest that diminished visual prowess among domestic chickens reflect changes driven by the relaxation of functional constraints on vision, but the evidence identifying the underlying genetic mechanisms responsible for this change has not been definitively characterized. Here, a genome-wide analysis of the domestic chicken and Red Junglefowl genomes showed significant enrichment for positively selected genes involved in the development of vision. There were significant differences between domestic chickens and their wild ancestors regarding the level of mRNA expression for these genes in the retina. Numerous additional genes involved in the development of vision also showed significant differences in mRNA expression between domestic chickens and their wild ancestors, particularly for genes associated with phototransduction and photoreceptor development, such as RHO (rhodopsin), GUCA1A, PDE6B and NR2E3. Finally, we characterized the potential role of the VIT gene in vision, which experienced positive selection and downregulated expression in the retina of the village chicken. Overall, our results suggest that positive selection, rather than relaxation of purifying selection, contributed to the evolution of vision in domestic chickens. The progenitors of domestic chickens harboring weaker vision may have showed a reduced fear response and vigilance, making them easier to be unconsciously selected and/or domesticated.
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Affiliation(s)
- Ming-Shan Wang
- State Key Laboratory of Genetic Resources and Evolution, Yunnan Laboratory of Molecular Biology of Domestic Animals
- Kunming College of Life Science, Unisversity of Chinese Academy of Sciences, Kunming, Yunnan 650204, China
| | - Rong-wei Zhang
- Institute of Neuroscience and State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Ling-Yan Su
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan 650223, China
- Kunming College of Life Science, Unisversity of Chinese Academy of Sciences, Kunming, Yunnan 650204, China
| | - Yan Li
- State Key Laboratory of Genetic Resources and Evolution, Yunnan Laboratory of Molecular Biology of Domestic Animals
- Kunming College of Life Science, Unisversity of Chinese Academy of Sciences, Kunming, Yunnan 650204, China
| | - Min-Sheng Peng
- State Key Laboratory of Genetic Resources and Evolution, Yunnan Laboratory of Molecular Biology of Domestic Animals
- Kunming College of Life Science, Unisversity of Chinese Academy of Sciences, Kunming, Yunnan 650204, China
| | - He-Qun Liu
- State Key Laboratory of Genetic Resources and Evolution, Yunnan Laboratory of Molecular Biology of Domestic Animals
- Kunming College of Life Science, Unisversity of Chinese Academy of Sciences, Kunming, Yunnan 650204, China
| | - Lin Zeng
- State Key Laboratory of Genetic Resources and Evolution, Yunnan Laboratory of Molecular Biology of Domestic Animals
- Kunming College of Life Science, Unisversity of Chinese Academy of Sciences, Kunming, Yunnan 650204, China
| | - David M Irwin
- State Key Laboratory of Genetic Resources and Evolution, Yunnan Laboratory of Molecular Biology of Domestic Animals
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
- Banting and Best Diabetes Centre, University of Toronto, Toronto, Canada
| | - Jiu-Lin Du
- Institute of Neuroscience and State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Yong-Gang Yao
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan 650223, China
- Kunming College of Life Science, Unisversity of Chinese Academy of Sciences, Kunming, Yunnan 650204, China
| | - Dong-Dong Wu
- State Key Laboratory of Genetic Resources and Evolution, Yunnan Laboratory of Molecular Biology of Domestic Animals
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan 650223, China
| | - Ya-Ping Zhang
- State Key Laboratory of Genetic Resources and Evolution, Yunnan Laboratory of Molecular Biology of Domestic Animals
- Kunming College of Life Science, Unisversity of Chinese Academy of Sciences, Kunming, Yunnan 650204, China
- Laboratory for Conservation and Utilization of Bio-resource, Yunnan University, Kunming, Yunnan 650091, China
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8
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Nhu D, Lessene G, Huang DCS, Burns CJ. Small molecules targeting Mcl-1: the search for a silver bullet in cancer therapy. MEDCHEMCOMM 2016. [DOI: 10.1039/c5md00582e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Progress towards the development of potent and selective inhibitors of the pro-survival protein Mcl-1 is reviewed.
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Affiliation(s)
- Duong Nhu
- The Walter and Eliza Hall Institute of Medical Research
- Australia
- Department of Medical Biology
- The University of Melbourne
- Australia
| | - Guillaume Lessene
- The Walter and Eliza Hall Institute of Medical Research
- Australia
- Department of Medical Biology
- The University of Melbourne
- Australia
| | - David C. S. Huang
- The Walter and Eliza Hall Institute of Medical Research
- Australia
- Department of Medical Biology
- The University of Melbourne
- Australia
| | - Christopher J. Burns
- The Walter and Eliza Hall Institute of Medical Research
- Australia
- Department of Medical Biology
- The University of Melbourne
- Australia
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9
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Pai VP, Martyniuk CJ, Echeverri K, Sundelacruz S, Kaplan DL, Levin M. Genome-wide analysis reveals conserved transcriptional responses downstream of resting potential change in Xenopus embryos, axolotl regeneration, and human mesenchymal cell differentiation. ACTA ACUST UNITED AC 2015; 3:3-25. [PMID: 27499876 PMCID: PMC4857752 DOI: 10.1002/reg2.48] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 08/20/2015] [Accepted: 08/25/2015] [Indexed: 12/14/2022]
Abstract
Endogenous bioelectric signaling via changes in cellular resting potential (Vmem) is a key regulator of patterning during regeneration and embryogenesis in numerous model systems. Depolarization of Vmem has been functionally implicated in dedifferentiation, tumorigenesis, anatomical re‐specification, and appendage regeneration. However, no unbiased analyses have been performed to understand genome‐wide transcriptional responses to Vmem change in vivo. Moreover, it is unknown which genes or gene networks represent conserved targets of bioelectrical signaling across different patterning contexts and species. Here, we use microarray analysis to comparatively analyze transcriptional responses to Vmem depolarization. We compare the response of the transcriptome during embryogenesis (Xenopus development), regeneration (axolotl regeneration), and stem cell differentiation (human mesenchymal stem cells in culture) to identify common networks across model species that are associated with depolarization. Both subnetwork enrichment and PANTHER analyses identified a number of key genetic modules as targets of Vmem change, and also revealed important (well‐conserved) commonalities in bioelectric signal transduction, despite highly diverse experimental contexts and species. Depolarization regulates specific transcriptional networks across all three germ layers (ectoderm, mesoderm, and endoderm) such as cell differentiation and apoptosis, and this information will be used for developing mechanistic models of bioelectric regulation of patterning. Moreover, our analysis reveals that Vmem change regulates transcripts related to important disease pathways such as cancer and neurodegeneration, which may represent novel targets for emerging electroceutical therapies.
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Affiliation(s)
- Vaibhav P Pai
- Biology Department and Center for Regenerative and Developmental Biology Tufts University Medford Massachusetts 02155 USA
| | - Christopher J Martyniuk
- Center for Environmental and Human Toxicology and Department of Physiological Sciences UF Genetics Institute, University of Florida Gainesville Florida 32611 USA
| | - Karen Echeverri
- Department of Genetics, Cell Biology and Development University of Minnesota Minneapolis Minnesota 55455 USA
| | - Sarah Sundelacruz
- Department of Biomedical Engineering Tufts University Medford Massachusetts 02155 USA
| | - David L Kaplan
- Department of Biomedical Engineering Tufts University Medford Massachusetts 02155 USA
| | - Michael Levin
- Biology Department and Center for Regenerative and Developmental Biology Tufts University Medford Massachusetts 02155 USA
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10
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Temajo NO, Howard N. The virus-induced HSPs regulate the apoptosis of operatus APCs that result in autoimmunity, not in homeostasis. Immunol Res 2015; 60:208-18. [PMID: 25403694 DOI: 10.1007/s12026-014-8585-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The viruses stand salient as environmental factors that trigger autoimmunity. The virus realizes its effects through induction of heat-shock proteins (HSPs) as well as by the viral IE-axis-mediated conversion of organ epithelial cells into virgin de novo professional antigen-presenting cells (APCs). The HSP is the accomplished operator in homeostasis by the logic of it being the regulator of apoptosis. By virtue of its regulation of apoptosis, the HSP is also involved in autoimmunity: (1) adornment of viral IE-axis-generated virgin de novo professional APCs with HSP-induced co-stimulatory molecules which transform these otherwise epithelial cells to competent antigen presenters, the operatus APCs, liable to apoptosis that becomes the initiator of organ damages; (2) molecular mimicry mechanism: epitopes on the HSP may be mistaken for viral peptides and be presented by operatus APCs to autoreactive TCRs resulting in the apoptosis of the operatus APCs; (3) regulation of MHC class II DR-mediated apoptosis of operatus APCS which can result in organ-specific autoimmune syndromes. We should remember, however, that Nature's intended purpose for apoptosis of the professional APCs is benevolence: as a principal regulator of immune homeostasis. But the apoptosis of our postulated operatus APCs can result in autoimmunity. The transformation of virgin de novo professional APCs to operatus APCs mirrors the maturation of DCs through their acquisition of HSP-induced costimulatory molecules. What happens to mature DCs as antigen presenters that end in homeostasis is replicated by what happens to operatus APCs that ends instead in autoimmunity.
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Affiliation(s)
- Norbert O Temajo
- Institute of Endocrinology and Diabetes, The Children's Hospital at Westmead, Sydney, NSW, Australia,
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11
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Yu D, Mu S, Zhao D, Wang G, Chen Z, Ren H, Fu Q. Puerarin attenuates glucocorticoid-induced apoptosis of hFOB1.19 cells through the JNK- and Akt-mediated mitochondrial apoptotic pathways. Int J Mol Med 2015; 36:345-54. [PMID: 26101183 PMCID: PMC4501663 DOI: 10.3892/ijmm.2015.2258] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 05/21/2015] [Indexed: 12/13/2022] Open
Abstract
Puerarin is an active component of Pueraria lobata, which is a commonly used Chinese herbal medicine for the treatment of osteoporosis. The present study aimed to evaluate the osteoprotective effect of puerarin on glucocorticoid (GC)-induced apoptosis of osteoblasts in vitro. The effects of puerarin on dexamethasone (DEX)-induced cell apoptosis were assessed using enzyme-linked immunosorbent assay and a terminal deoxynucleotidyl transferase dUTP nick-end labeling assay, and found that the viability of hFOB1.19 cells was significantly increased following exposure to between 10−6 and 10−10 M puerarin, with a maximal anti-apoptotic effect at a concentration of 10−8 M. In addition, compared with the control group, puerarin upregulated the transcription and protein levels of B-cell lymphoma-2 and downregulated B-cell-associated X protein in the hFOB1.19 cells. Puerarin attenuated the DEX-induced release of cytochrome c and cleavage of caspase-3, and treatment with puerarin inhibited the c-Jun N-terminal kinase (JNK) pathway and activated the phosphoinositide 3-kinase (PI3K)/Akt pathway in the hFOB1.19 cells. Furthermore, the Akt inhibitor, LY294002, partly eliminated the protective effect of puerarin on DEX-induced apoptosis, and puerarin combined with the JNK inhibitor, SP600125, suppressed DEX-induced apoptosis to a lesser extent than in the cells treated with SP600125 alone. These results suggested that the JNK and PI3K/Akt signaling pathways mediate the inhibitory effects of puerarin on apoptosis in the hFOB1.19 cells. In conclusion, puerarin prevented DEX-induced apoptosis of hFOB1.19 cells via inhibition of the JNK pathway and activation of the PI3K/Akt signaling pathway in the cells, dependent on the mitochondrial apoptotic pathway. These results support puerarin as a promising target in the treatment of GC-induced osteoporosis.
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Affiliation(s)
- Dongdong Yu
- Department of Orthopedic Surgery, The Shengjing Hospital of China Medical University, Liaoning 110004, P.R. China
| | - Shuai Mu
- Department of Orthopedic Surgery, The Shengjing Hospital of China Medical University, Liaoning 110004, P.R. China
| | - Danyang Zhao
- Department of Orthopedic Surgery, The Shengjing Hospital of China Medical University, Liaoning 110004, P.R. China
| | - Guangbin Wang
- Department of Orthopedic Surgery, The Shengjing Hospital of China Medical University, Liaoning 110004, P.R. China
| | - Zhiguang Chen
- Department of Orthopedic Surgery, The Shengjing Hospital of China Medical University, Liaoning 110004, P.R. China
| | - Hongfei Ren
- Department of Orthopedic Surgery, The Shengjing Hospital of China Medical University, Liaoning 110004, P.R. China
| | - Qin Fu
- Department of Orthopedic Surgery, The Shengjing Hospital of China Medical University, Liaoning 110004, P.R. China
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12
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Evolutionary Developmental Biology and the Limits of Philosophical Accounts of Mechanistic Explanation. HISTORY, PHILOSOPHY AND THEORY OF THE LIFE SCIENCES 2015. [DOI: 10.1007/978-94-017-9822-8_7] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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13
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Kepp O, Senovilla L, Vitale I, Vacchelli E, Adjemian S, Agostinis P, Apetoh L, Aranda F, Barnaba V, Bloy N, Bracci L, Breckpot K, Brough D, Buqué A, Castro MG, Cirone M, Colombo MI, Cremer I, Demaria S, Dini L, Eliopoulos AG, Faggioni A, Formenti SC, Fučíková J, Gabriele L, Gaipl US, Galon J, Garg A, Ghiringhelli F, Giese NA, Guo ZS, Hemminki A, Herrmann M, Hodge JW, Holdenrieder S, Honeychurch J, Hu HM, Huang X, Illidge TM, Kono K, Korbelik M, Krysko DV, Loi S, Lowenstein PR, Lugli E, Ma Y, Madeo F, Manfredi AA, Martins I, Mavilio D, Menger L, Merendino N, Michaud M, Mignot G, Mossman KL, Multhoff G, Oehler R, Palombo F, Panaretakis T, Pol J, Proietti E, Ricci JE, Riganti C, Rovere-Querini P, Rubartelli A, Sistigu A, Smyth MJ, Sonnemann J, Spisek R, Stagg J, Sukkurwala AQ, Tartour E, Thorburn A, Thorne SH, Vandenabeele P, Velotti F, Workenhe ST, Yang H, Zong WX, Zitvogel L, Kroemer G, Galluzzi L. Consensus guidelines for the detection of immunogenic cell death. Oncoimmunology 2014; 3:e955691. [PMID: 25941621 PMCID: PMC4292729 DOI: 10.4161/21624011.2014.955691] [Citation(s) in RCA: 645] [Impact Index Per Article: 58.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 08/04/2014] [Indexed: 02/07/2023] Open
Abstract
Apoptotic cells have long been considered as intrinsically tolerogenic or unable to elicit immune responses specific for dead cell-associated antigens. However, multiple stimuli can trigger a functionally peculiar type of apoptotic demise that does not go unnoticed by the adaptive arm of the immune system, which we named "immunogenic cell death" (ICD). ICD is preceded or accompanied by the emission of a series of immunostimulatory damage-associated molecular patterns (DAMPs) in a precise spatiotemporal configuration. Several anticancer agents that have been successfully employed in the clinic for decades, including various chemotherapeutics and radiotherapy, can elicit ICD. Moreover, defects in the components that underlie the capacity of the immune system to perceive cell death as immunogenic negatively influence disease outcome among cancer patients treated with ICD inducers. Thus, ICD has profound clinical and therapeutic implications. Unfortunately, the gold-standard approach to detect ICD relies on vaccination experiments involving immunocompetent murine models and syngeneic cancer cells, an approach that is incompatible with large screening campaigns. Here, we outline strategies conceived to detect surrogate markers of ICD in vitro and to screen large chemical libraries for putative ICD inducers, based on a high-content, high-throughput platform that we recently developed. Such a platform allows for the detection of multiple DAMPs, like cell surface-exposed calreticulin, extracellular ATP and high mobility group box 1 (HMGB1), and/or the processes that underlie their emission, such as endoplasmic reticulum stress, autophagy and necrotic plasma membrane permeabilization. We surmise that this technology will facilitate the development of next-generation anticancer regimens, which kill malignant cells and simultaneously convert them into a cancer-specific therapeutic vaccine.
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Key Words
- APC, antigen-presenting cell
- ATF6, activating transcription factor 6
- ATP release
- BAK1, BCL2-antagonist/killer 1
- BAX, BCL2-associated X protein
- BCL2, B-cell CLL/lymphoma 2 protein
- CALR, calreticulin
- CTL, cytotoxic T lymphocyte
- DAMP, damage-associated molecular pattern
- DAPI, 4′,6-diamidino-2-phenylindole
- DiOC6(3), 3,3′-dihexyloxacarbocyanine iodide
- EIF2A, eukaryotic translation initiation factor 2A
- ER, endoplasmic reticulum
- FLT3LG, fms-related tyrosine kinase 3 ligand
- G3BP1, GTPase activating protein (SH3 domain) binding protein 1
- GFP, green fluorescent protein
- H2B, histone 2B
- HMGB1
- HMGB1, high mobility group box 1
- HSP, heat shock protein
- HSV-1, herpes simplex virus type I
- ICD, immunogenic cell death
- IFN, interferon
- IL, interleukin
- MOMP, mitochondrial outer membrane permeabilization
- PDIA3, protein disulfide isomerase family A
- PI, propidium iodide
- RFP, red fluorescent protein
- TLR, Toll-like receptor
- XBP1, X-box binding protein 1
- autophagy
- calreticulin
- endoplasmic reticulum stress
- immunotherapy
- member 3
- Δψm, mitochondrial transmembrane potential
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Affiliation(s)
- Oliver Kepp
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer; Center de Recherche des Cordeliers; Paris, France
- INSERM; U1138; Paris, France
- Metabolomics and Cell Biology Platforms; Gustave Roussy Cancer Campus; Villejuif, France
| | - Laura Senovilla
- INSERM; U1138; Paris, France
- Metabolomics and Cell Biology Platforms; Gustave Roussy Cancer Campus; Villejuif, France
- INSERM; U1015; Villejuif, France
| | - Ilio Vitale
- Regina Elena National Cancer Institute; Rome, Italy
| | - Erika Vacchelli
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer; Center de Recherche des Cordeliers; Paris, France
- INSERM; U1138; Paris, France
- Gustave Roussy Cancer Campus; Villejuif, France
| | - Sandy Adjemian
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer; Center de Recherche des Cordeliers; Paris, France
- INSERM; U1138; Paris, France
- Gustave Roussy Cancer Campus; Villejuif, France
- Molecular Cell Biology Laboratory; Department of Immunology; Institute of Biomedical Sciences; University of São Paulo; São Paulo, Brazil
| | - Patrizia Agostinis
- Cell Death Research and Therapy (CDRT) Laboratory; Department of Cellular and Molecular Medicine; University of Leuven; Leuven, Belgium
| | - Lionel Apetoh
- INSERM; UMR866; Dijon, France
- Centre Georges François Leclerc; Dijon, France
- Université de Bourgogne; Dijon, France
| | - Fernando Aranda
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer; Center de Recherche des Cordeliers; Paris, France
- INSERM; U1138; Paris, France
- Gustave Roussy Cancer Campus; Villejuif, France
| | - Vincenzo Barnaba
- Departement of Internal Medicine and Medical Sciences; University of Rome La Sapienza; Rome, Italy
- Istituto Pasteur; Fondazione Cenci Bolognetti; Rome, Italy
| | - Norma Bloy
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer; Center de Recherche des Cordeliers; Paris, France
- INSERM; U1138; Paris, France
- Gustave Roussy Cancer Campus; Villejuif, France
| | - Laura Bracci
- Department of Hematology; Oncology and Molecular Medicine; Istituto Superiore di Sanità (ISS); Rome, Italy
| | - Karine Breckpot
- Laboratory of Molecular and Cellular Therapy (LMCT); Department of Biomedical Sciences Medical School of the Free University of Brussels (VUB); Jette, Belgium
| | - David Brough
- Faculty of Life Sciences; University of Manchester; Manchester, UK
| | - Aitziber Buqué
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer; Center de Recherche des Cordeliers; Paris, France
- INSERM; U1138; Paris, France
- Gustave Roussy Cancer Campus; Villejuif, France
| | - Maria G. Castro
- Department of Neurosurgery and Cell and Developmental Biology; University of Michigan School of Medicine; Ann Arbor, MI USA
| | - Mara Cirone
- Department of Experimental Medicine; University of Rome La Sapienza; Rome, Italy
| | - Maria I. Colombo
- Laboratorio de Biología Celular y Molecular; Instituto de Histología y Embriología (IHEM); Facultad de Ciencias Médicas; Universidad Nacional de Cuyo; CONICET; Mendoza, Argentina
| | - Isabelle Cremer
- INSERM; U1138; Paris, France
- Université Pierre et Marie Curie/Paris VI; Paris, France
- Equipe 13; Center de Recherche des Cordeliers; Paris, France
| | - Sandra Demaria
- Department of Pathology; New York University School of Medicine; New York, NY USA
| | - Luciana Dini
- Department of Biological and Environmental Science and Technology (DiSTeBA); University of Salento; Lecce, Italy
| | - Aristides G. Eliopoulos
- Molecular and Cellular Biology Laboratory; Division of Basic Sciences; University of Crete Medical School; Heraklion, Greece
- Institute of Molecular Biology and Biotechnology; Foundation of Research and Technology - Hellas; Heraklion, Greece
| | - Alberto Faggioni
- Department of Experimental Medicine; University of Rome La Sapienza; Rome, Italy
| | - Silvia C. Formenti
- Department of Radiation Oncology; NewYork University School of Medicine and Langone Medical Center; New York, NY USA
| | - Jitka Fučíková
- Department of Immunology; 2 Faculty of Medicine and University Hospital Motol, Charles University; Prague, Czech Republic
- Sotio; Prague, Czech Republic
| | - Lucia Gabriele
- Department of Hematology; Oncology and Molecular Medicine; Istituto Superiore di Sanità (ISS); Rome, Italy
| | - Udo S. Gaipl
- Department of Radiation Oncology; University Hospital Erlangen; University of Erlangen-Nürnberg; Erlangen, Germany
| | - Jérôme Galon
- INSERM; U1138; Paris, France
- Université Pierre et Marie Curie/Paris VI; Paris, France
- Université Paris Descartes/Paris V; Sorbonne Paris Cité; Paris, France
- Laboratory of Integrative Cancer Immunology; Center de Recherche des Cordeliers; Paris, France
| | - Abhishek Garg
- Cell Death Research and Therapy (CDRT) Laboratory; Department of Cellular and Molecular Medicine; University of Leuven; Leuven, Belgium
| | - François Ghiringhelli
- INSERM; UMR866; Dijon, France
- Centre Georges François Leclerc; Dijon, France
- Université de Bourgogne; Dijon, France
| | - Nathalia A. Giese
- European Pancreas Center; Department of Surgery; University Hospital Heidelberg; Heidelberg, Germany
| | - Zong Sheng Guo
- Department of Surgery; University of Pittsburgh; Pittsburgh, PA USA
| | - Akseli Hemminki
- Cancer Gene Therapy Group; Transplantation laboratory; Haartman Institute; University of Helsinki; Helsinki, Finland
| | - Martin Herrmann
- Department of Internal Medicine 3; University of Erlangen-Nuremberg; Erlangen, Germany
| | - James W. Hodge
- Laboratory of Tumor Immunology and Biology; Center for Cancer Research; National Cancer Institute (NCI), National Institutes of Health (NIH); Bethesda, MD USA
| | - Stefan Holdenrieder
- Institute of Clinical Chemistry and Clinical Pharmacology; University Hospital Bonn; Bonn, Germany
| | - Jamie Honeychurch
- Faculty of Medical and Human Sciences, Institute of Cancer Studies; Manchester Academic Health Sciences Center; University of Manchester; Manchester, UK
| | - Hong-Min Hu
- Cancer Research and Biotherapy Center; Second Affiliated Hospital of Southeast University; Nanjing, China
- Laboratory of Cancer Immunobiology; Earle A. Chiles Research Institute; Providence Portland Medical Center; Portland, OR USA
| | - Xing Huang
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer; Center de Recherche des Cordeliers; Paris, France
- INSERM; U1138; Paris, France
- Metabolomics and Cell Biology Platforms; Gustave Roussy Cancer Campus; Villejuif, France
| | - Tim M. Illidge
- Faculty of Medical and Human Sciences, Institute of Cancer Studies; Manchester Academic Health Sciences Center; University of Manchester; Manchester, UK
| | - Koji Kono
- Department of Surgery; National University of Singapore; Singapore, Singapore
- Cancer Science Institute of Singapore; National University of Singapore; Singapore, Singapore
| | | | - Dmitri V. Krysko
- VIB Inflammation Research Center; Ghent, Belgium
- Department of Biomedical Molecular Biology; Ghent University; Ghent, Belgium
| | - Sherene Loi
- Division of Cancer Medicine and Division of Research; Peter MacCallum Cancer Center; East Melbourne; Victoria, Australia
| | - Pedro R. Lowenstein
- Department of Neurosurgery and Cell and Developmental Biology; University of Michigan School of Medicine; Ann Arbor, MI USA
| | - Enrico Lugli
- Unit of Clinical and Experimental Immunology; Humanitas Clinical and Research Center; Milan, Italy
- Department of Medical Biotechnologies and Translational Medicine, University of Milan; Rozzano, Italy
| | - Yuting Ma
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer; Center de Recherche des Cordeliers; Paris, France
- INSERM; U1138; Paris, France
- Gustave Roussy Cancer Campus; Villejuif, France
| | - Frank Madeo
- Institute of Molecular Biosciences; University of Graz; Graz, Austria
| | - Angelo A. Manfredi
- University Vita-Salute San Raffaele; Milano, Italy
- San Raffaele Scientific Institute; Milano, Italy
| | - Isabelle Martins
- Gustave Roussy Cancer Campus; Villejuif, France
- INSERM, U1030; Villejuif, France
- Faculté de Médecine; Université Paris-Sud/Paris XI; Kremlin-Bicêtre, France
| | - Domenico Mavilio
- Unit of Clinical and Experimental Immunology; Humanitas Clinical and Research Center; Milan, Italy
- Department of Medical Biotechnologies and Translational Medicine, University of Milan; Rozzano, Italy
| | - Laurie Menger
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer; Center de Recherche des Cordeliers; Paris, France
- INSERM; U1138; Paris, France
- Gustave Roussy Cancer Campus; Villejuif, France
- Cancer Immunology Unit, Research Department of Haematology; University College London (UCL) Cancer Institute; London, UK
| | - Nicolò Merendino
- Department of Ecological and Biological Sciences (DEB), Tuscia University; Viterbo, Italy
| | - Michael Michaud
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer; Center de Recherche des Cordeliers; Paris, France
- INSERM; U1138; Paris, France
- Gustave Roussy Cancer Campus; Villejuif, France
| | - Gregoire Mignot
- Cellular and Molecular Immunology and Endocrinology, Oniris; Nantes, France
| | - Karen L. Mossman
- Department of Pathology and Molecular Medicine; McMaster Immunology Research Center; Hamilton, Canada
- Institute for Infectious Disease Research; McMaster University; Hamilton, Canada
| | - Gabriele Multhoff
- Department of Radiation Oncology; Klinikum rechts der Isar; Technical University of Munich; Munich, Germany
| | - Rudolf Oehler
- Comprehensive Cancer Center; Medical University of Vienna; Vienna, Austria
| | - Fabio Palombo
- Departement of Internal Medicine and Medical Sciences; University of Rome La Sapienza; Rome, Italy
- Istituto Pasteur; Fondazione Cenci Bolognetti; Rome, Italy
| | | | - Jonathan Pol
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer; Center de Recherche des Cordeliers; Paris, France
- INSERM; U1138; Paris, France
- Gustave Roussy Cancer Campus; Villejuif, France
| | - Enrico Proietti
- Department of Hematology; Oncology and Molecular Medicine; Istituto Superiore di Sanità (ISS); Rome, Italy
| | - Jean-Ehrland Ricci
- INSERM; U1065; Nice, France
- Equipe “Contrôle Métabolique des Morts Cellulaires,” Center Méditerranéen de Médecine Moléculaire (C3M); Nice, France
- Faculté de Médecine; Université de Nice Sophia Antipolis; Nice, France
- Centre Hospitalier Universitaire de Nice; Nice, France
| | - Chiara Riganti
- Department of Oncology and Subalpine Center for Research and Experimental Medicine (CeRMS); University of Turin; Turin, Italy
| | - Patrizia Rovere-Querini
- University Vita-Salute San Raffaele; Milano, Italy
- San Raffaele Scientific Institute; Milano, Italy
| | - Anna Rubartelli
- Cell Biology Unit; Azienda Ospedaliera Universitaria San Martino; Istituto Nazionale per la Ricerca sul Cancro; Genova, Italy
| | | | - Mark J. Smyth
- Immunology in Cancer and Infection Laboratory; QIMR Berghofer Medical Research Institute; Herston, Australia
- School of Medicine, University of Queensland; Herston, Australia
| | - Juergen Sonnemann
- Department of Pediatric Haematology and Oncology; Jena University Hospital, Children's Clinic; Jena, Germany
| | - Radek Spisek
- Department of Immunology; 2 Faculty of Medicine and University Hospital Motol, Charles University; Prague, Czech Republic
- Sotio; Prague, Czech Republic
| | - John Stagg
- Centre de Recherche du Center Hospitalier de l’Université de Montréal; Faculté de Pharmacie, Université de Montréal; Montréal, Canada
| | - Abdul Qader Sukkurwala
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer; Center de Recherche des Cordeliers; Paris, France
- INSERM; U1138; Paris, France
- Gustave Roussy Cancer Campus; Villejuif, France
- Department of Pathology, Dow International Medical College; Dow University of Health Sciences; Karachi, Pakistan
| | - Eric Tartour
- INSERM; U970; Paris, France
- Pôle de Biologie; Hôpital Européen Georges Pompidou; AP-HP; Paris, France
| | - Andrew Thorburn
- Department of Pharmacology; University of Colorado School of Medicine; Aurora, CO USA
| | | | - Peter Vandenabeele
- VIB Inflammation Research Center; Ghent, Belgium
- Department of Biomedical Molecular Biology; Ghent University; Ghent, Belgium
- Methusalem Program; Ghent University; Ghent, Belgium
| | - Francesca Velotti
- Department of Ecological and Biological Sciences (DEB), Tuscia University; Viterbo, Italy
| | - Samuel T. Workenhe
- Department of Pathology and Molecular Medicine; McMaster Immunology Research Center; Hamilton, Canada
- Institute for Infectious Disease Research; McMaster University; Hamilton, Canada
| | - Haining Yang
- University of Hawaii Cancer Center; Honolulu, HI USA
| | - Wei-Xing Zong
- Department of Molecular Genetics and Microbiology; Stony Brook University; Stony Brook, NY USA
| | - Laurence Zitvogel
- INSERM; U1015; Villejuif, France
- Gustave Roussy Cancer Campus; Villejuif, France
- Centre d’Investigation Clinique Biothérapie 507 (CICBT507); Gustave Roussy Cancer Campus; Villejuif, France
| | - Guido Kroemer
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer; Center de Recherche des Cordeliers; Paris, France
- INSERM; U1138; Paris, France
- Metabolomics and Cell Biology Platforms; Gustave Roussy Cancer Campus; Villejuif, France
- Université Paris Descartes/Paris V; Sorbonne Paris Cité; Paris, France
- Pôle de Biologie; Hôpital Européen Georges Pompidou; AP-HP; Paris, France
| | - Lorenzo Galluzzi
- Equipe 11 labellisée par la Ligue Nationale contre le Cancer; Center de Recherche des Cordeliers; Paris, France
- INSERM; U1138; Paris, France
- Gustave Roussy Cancer Campus; Villejuif, France
- Université Paris Descartes/Paris V; Sorbonne Paris Cité; Paris, France
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14
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Temajo NO, Howard N. The virus-induced HSPs regulate the apoptosis of operatus APCs that results in autoimmunity, not in homeostasis. Autoimmun Rev 2014; 13:1013-9. [PMID: 25183243 DOI: 10.1016/j.autrev.2014.08.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 05/30/2014] [Indexed: 12/20/2022]
Abstract
The viruses are salient in the roles of environmental factors that trigger autoimmunity. The virus realizes its effects by the power of its induction of heat shock proteins (HSPs) as well as by the viral IE-axis-mediated conversion of organ epithelial cells into virgin de novo professional antigen-presenting cells (APCs). The HSP is the accomplished operator in homeostasis by the logic of it being the regulator of apoptosis. That HSP which regulates and controls different points in the pathways of apoptosis is rationally propitious as both HSP and apoptosis are highly conserved in multicellular organisms. By virtue of its regulation of apoptosis, the HSP is also involved in human autoimmunity and this involvement is tripartite: (i) adornment of viral IE-axis-generated virgin de novo professional APCs with HSP-induced co-stimulatory molecules which transform these otherwise epithelial cells to achieve the status of fledged competent antigen-presenters, the operatus APCs, which are liable to apoptosis that becomes the initiator of organ damages that can culminate in the autoimmune syndrome(s); apoptosis is a routine fate that befalls all APCs following their antigen presentation; (ii) molecular mimicry mechanism: epitopes on the HSP may be mistaken for viral peptides and be presented by operatus APCs to autoreactive TCRs resulting in the apoptosis of the operatus APCs; and (iii) regulation of MHC class II-DR-mediated apoptosis of operatus APCs which can ultimately consequent in organ-specific autoimmune syndromes. We should remember, however, that Nature's intended purpose for the apoptosis of the professional APCs is benevolence: as a principal regulator of homeostasis. It is only from the apoptosis of our postulated operatus APCs that the apoptotic consequence can be deleterious, an autoimmune syndrome(s). The transformation of virgin de novo professional APCs to operatus APCs mirrors the maturation of DCs, through their acquisition of HSP-induced co-stimulatory molecules; and what happens to mature DCs as antigen-presenters that ends in homeostasis is replicated by what happens to operatus APCs that ends instead in autoimmune syndromes (Fig. 1).
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Affiliation(s)
- Norbert O Temajo
- Institute of Endocrinology and Diabetes, The Children's Hospital at Westmead, Sydney, NSW, Australia.
| | - Neville Howard
- Institute of Endocrinology and Diabetes, The Children's Hospital at Westmead, Sydney, NSW, Australia.
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15
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Brigandt I. Systems biology and the integration of mechanistic explanation and mathematical explanation. STUDIES IN HISTORY AND PHILOSOPHY OF BIOLOGICAL AND BIOMEDICAL SCIENCES 2013; 44:477-492. [PMID: 23863399 DOI: 10.1016/j.shpsc.2013.06.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Revised: 06/12/2013] [Accepted: 06/14/2013] [Indexed: 06/02/2023]
Abstract
The paper discusses how systems biology is working toward complex accounts that integrate explanation in terms of mechanisms and explanation by mathematical models-which some philosophers have viewed as rival models of explanation. Systems biology is an integrative approach, and it strongly relies on mathematical modeling. Philosophical accounts of mechanisms capture integrative in the sense of multilevel and multifield explanations, yet accounts of mechanistic explanation (as the analysis of a whole in terms of its structural parts and their qualitative interactions) have failed to address how a mathematical model could contribute to such explanations. I discuss how mathematical equations can be explanatorily relevant. Several cases from systems biology are discussed to illustrate the interplay between mechanistic research and mathematical modeling, and I point to questions about qualitative phenomena (rather than the explanation of quantitative details), where quantitative models are still indispensable to the explanation. Systems biology shows that a broader philosophical conception of mechanisms is needed, which takes into account functional-dynamical aspects, interaction in complex networks with feedback loops, system-wide functional properties such as distributed functionality and robustness, and a mechanism's ability to respond to perturbations (beyond its actual operation). I offer general conclusions for philosophical accounts of explanation.
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Affiliation(s)
- Ingo Brigandt
- Department of Philosophy, University of Alberta, 2-40 Assiniboia Hall, Edmonton, AB T6G2E7, Canada.
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16
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Liu LJ, Liu LQ, Bo T, Li SJ, Zhu Z, Cui RR, Mao DA. Puerarin Suppress Apoptosis of Human Osteoblasts via ERK Signaling Pathway. Int J Endocrinol 2013; 2013:786574. [PMID: 23843790 PMCID: PMC3694486 DOI: 10.1155/2013/786574] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 03/31/2013] [Accepted: 04/10/2013] [Indexed: 12/15/2022] Open
Abstract
Puerarin, the main isoflavone glycoside extracted from Radix Puerariae, is an isoflavone traditional Chinese herb. Previous studies have demonstrated that puerarin could regulate osteoblast proliferation and differentiation to promote bone formation. However, the effect of puerarin on the process of human osteoblasts (hOBs) apoptosis is still unclear. In this study, we detected the function of puerarin on serum-free-induced cell apoptosis using ELISA and TUNEL arrays and then found that the mortality of hOBs was significantly decreased after exposure to 10(-10)-10(-6) M puerarin and reached the maximal antiapoptotic effect at the concentration of 10(-8) M. In addition, compared with the control group, puerarin notably increased the Bcl-2 protein levels while it decreased the Bax protein levels in the hOBs in a dose-dependent way. 10(-7) M puerarin decreased the Bax/Bcl-2 ratio with a maximal decrease to 0.08. Moreover, puerarin activated ERK signaling pathways in hOBs, and the antiapoptotic effect induced by puerarin was abolished by incubation of ERK inhibitor PD98059. Similarly, the estrogen receptor antagonist ICI182780 also suppressed the inhibitory effect of puerarin on hOBs apoptosis. In conclusion, puerarin could prevent hOBs apoptosis via ERK signaling pathway, which might be effective in providing protection against bone loss and bone remolding associated with osteoporosis.
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Affiliation(s)
- Ling-juan Liu
- Department of Pediatrics, The Second Xiang-Ya Hospital, Central South University, 139 Middle Renmin Road, Changsha, Hunan 410011, China
| | - Li-qun Liu
- Department of Pediatrics, The Second Xiang-Ya Hospital, Central South University, 139 Middle Renmin Road, Changsha, Hunan 410011, China
| | - Tao Bo
- Department of Pediatrics, The Second Xiang-Ya Hospital, Central South University, 139 Middle Renmin Road, Changsha, Hunan 410011, China
| | - Shi-jun Li
- Department of Pediatrics, The Second Xiang-Ya Hospital, Central South University, 139 Middle Renmin Road, Changsha, Hunan 410011, China
| | - Zhen Zhu
- Department of Pediatrics, The Second Xiang-Ya Hospital, Central South University, 139 Middle Renmin Road, Changsha, Hunan 410011, China
| | - Rong-rong Cui
- Institute of Metabolism and Endocrinology, The Second Xiang-Ya Hospital, Central South University, 139 Middle Renmin Road, Changsha, Hunan 410011, China
- *Rong-rong Cui: and
| | - Ding-an Mao
- Department of Pediatrics, The Second Xiang-Ya Hospital, Central South University, 139 Middle Renmin Road, Changsha, Hunan 410011, China
- *Ding-an Mao:
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17
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17β-estradiol combined with testosterone promotes chicken osteoblast proliferation and differentiation by accelerating the cell cycle and inhibiting apoptosis in vitro. Vet Res Commun 2010; 34:143-52. [DOI: 10.1007/s11259-010-9340-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2010] [Indexed: 10/19/2022]
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18
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Shah S, Smith H, Feng X, Rancourt DE, Riabowol K. ING function in apoptosis in diverse model systems. Biochem Cell Biol 2009; 87:117-25. [PMID: 19234528 DOI: 10.1139/o08-107] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Genetic studies in model organisms have shown that programmed cell death (apoptosis) plays a significant role during development, where a deficiency in apoptosis results in severe and diverse diseases. Dysregulation of apoptosis also contributes to a variety of human diseases, such as cancer and autoimmune diseases. ING family proteins (ING1-ING5) are involved in many cellular processes, and appear to play a significant role in apoptosis. Loss or downregulation of ING protein function is frequently observed in different tumour types, many of which are resistant to apoptosis, thus warranting their classification as type II tumour suppressors. Several different in vitro and in vivo models have explored the role of ING proteins in regulating apoptosis. In this review, we discuss the progress that has been made in understanding ING protein function in apoptosis using in vitro studies and Mus musculus, Xenopus laevis, and Caenorhabditis elegans experimental models, with an emphasis on ING1 and ING3.
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Affiliation(s)
- Sitar Shah
- Southern Alberta Cancer Research Institute, Department of Biochemistry & Molecular Biology, Faculty of Medicine, University of Calgary, 3330 Hospital Dr. NW, Calgary, ABT2N4N1, Canada
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19
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Pearson JF, Hughes S, Chambers K, Lang SH. Polarized fluid movement and not cell death, creates luminal spaces in adult prostate epithelium. Cell Death Differ 2009; 16:475-82. [PMID: 19096393 PMCID: PMC2857323 DOI: 10.1038/cdd.2008.181] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
There are two predominant theories for lumen formation in tissue morphogenesis: cavitation driven by cell death, and membrane separation driven by epithelial polarity. To define the mechanism of lumen formation in prostate acini, we examined both theories in several cell lines grown in three-dimensional (3D) Matrigel culture. Lumen formation occurred early in culture and preceded the expression of cell death markers for apoptosis (active caspase 3) and autophagy (LC-3). Active caspase 3 was expressed by very few cells and inhibition of apoptosis did not suppress lumen formation. Despite LC-3 expression in all cells within a spheroid, this was not associated with cell death. However, expression of a prostate-secretory protein coincided with lumen formation and subsequent disruption of polarized fluid movement led to significant inhibition of lumen formation. This work indicates that lumen formation is driven by the polarized movement of fluids and proteins in 3D prostate epithelial models and not by cavitation.
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Affiliation(s)
- J F Pearson
- YCR Cancer Research Unit, Department of Biology, University of York, Heslington, York YO10 5YW, UK
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20
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Davuluri G, Gong W, Yusuff S, Lorent K, Muthumani M, Dolan AC, Pack M. Mutation of the zebrafish nucleoporin elys sensitizes tissue progenitors to replication stress. PLoS Genet 2008; 4:e1000240. [PMID: 18974873 PMCID: PMC2570612 DOI: 10.1371/journal.pgen.1000240] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2008] [Accepted: 09/29/2008] [Indexed: 12/15/2022] Open
Abstract
The recessive lethal mutation flotte lotte (flo) disrupts development of the zebrafish digestive system and other tissues. We show that flo encodes the ortholog of Mel-28/Elys, a highly conserved gene that has been shown to be required for nuclear integrity in worms and nuclear pore complex (NPC) assembly in amphibian and mammalian cells. Maternal elys expression sustains zebrafish flo mutants to larval stages when cells in proliferative tissues that lack nuclear pores undergo cell cycle arrest and apoptosis. p53 mutation rescues apoptosis in the flo retina and optic tectum, but not in the intestine, where the checkpoint kinase Chk2 is activated. Chk2 inhibition and replication stress induced by DNA synthesis inhibitors were lethal to flo larvae. By contrast, flo mutants were not sensitized to agents that cause DNA double strand breaks, thus showing that loss of Elys disrupts responses to selected replication inhibitors. Elys binds Mcm2-7 complexes derived from Xenopus egg extracts. Mutation of elys reduced chromatin binding of Mcm2, but not binding of Mcm3 or Mcm4 in the flo intestine. These in vivo data indicate a role for Elys in Mcm2-chromatin interactions. Furthermore, they support a recently proposed model in which replication origins licensed by excess Mcm2-7 are required for the survival of human cells exposed to replication stress. DNA replication is a complex process that requires activation of cell cycle checkpoints and DNA repair pathways. Genetic analyses in fungi have suggested that nucleoporins, the proteins that make up the nuclear pore complex (NPC), play a role in the cellular response to agents that disrupt cell proliferation or damage DNA. Here we show that mutation of the Elys nucleoporin causes widespread apoptosis in the intestine and other tissues of zebrafish flotte lotte (flo) mutants. Intestinal apoptosis occurs in the absence of the DNA damage marker γH2X, and levels of chromatin bound Mcm2, a component of the DNA replication helicase, were also reduced in flo mutants. These findings suggested that flo intestinal cells cannot repair endogenous replication errors. Consistent with this idea, flo mutants were highly sensitized to treatment with DNA replication inhibitors such as hydroxyurea, UV irradiation, or cisplatin, but not agents that cause DNA double strand breaks, such as γ-irradiation or camptothecin. These data point to a conserved role for nucleoporins in the cellular response to replication stress in eukaryote cells.
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Affiliation(s)
- Gangarao Davuluri
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Weilong Gong
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Shamila Yusuff
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Kristin Lorent
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Manimegalai Muthumani
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Amy C. Dolan
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Michael Pack
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- Department of Cell & Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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21
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Dix MM, Simon GM, Cravatt BF. Global mapping of the topography and magnitude of proteolytic events in apoptosis. Cell 2008; 134:679-91. [PMID: 18724940 PMCID: PMC2597167 DOI: 10.1016/j.cell.2008.06.038] [Citation(s) in RCA: 292] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2008] [Revised: 05/14/2008] [Accepted: 06/19/2008] [Indexed: 11/18/2022]
Abstract
Proteolysis is a key regulatory process that promotes the (in)activation, translocation, and/or degradation of proteins. As such, there is considerable interest in methods to comprehensively characterize proteolytic pathways in biological systems. Here, we describe a robust and versatile proteomic platform that enables direct visualization of the topography and magnitude of proteolytic events on a global scale. We use this method to generate a proteome-wide map of proteolytic events induced by the intrinsic apoptotic pathway. This profile contained 91 characterized caspase substrates as well as 170 additional proteins not previously known to be cleaved during apoptosis. Surprisingly, the vast majority of proteolyzed proteins, regardless of the extent of cleavage, yielded persistent fragments that correspond to discrete protein domains, suggesting that the generation of active effector proteins may be a principal function of apoptotic proteolytic cascades.
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Affiliation(s)
| | | | - Benjamin F. Cravatt
- The Skaggs Institute for Chemical Biology and Department of Chemical Physiology, The Scripps Research Institute, 10550 N. Torrey Pines Rd. La Jolla, CA 92037
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22
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Monserrate JP, Brachmann CB. Identification of the death zone: a spatially restricted region for programmed cell death that sculpts the fly eye. Cell Death Differ 2006; 14:209-17. [PMID: 16710366 DOI: 10.1038/sj.cdd.4401947] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Programmed cell death (PCD) sculpts many developing tissues. The final patterning step of the Drosophila retina is the elimination, through PCD, of a subset of interommatidial lattice cells during pupation. It is not understood how this process is spatially regulated to ensure that cells die in the proper positions. To address this, we observed PCD of lattice cells in the pupal retina in real time. This live-visualization method demonstrates that lattice cell apoptosis is a highly specific process. In all, 85% of lattice cells die in exclusive 'death zone' positions between adjacent ommatidia. In contrast, cells that make specific contacts with primary pigment cells are protected from death. Two signaling pathways, Drosophila epidermal growth factor receptor (dEgfr) and Notch, that are thought to be central to the regulation of lattice cell survival and death, are not sufficient to establish the death zone. Thus, application of live visualization to the fly eye gives new insight into a dynamic developmental process.
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Affiliation(s)
- J P Monserrate
- Developmental and Cell Biology, University of California Irvine, Irvine, CA 92697, USA
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Wiren KM, Toombs AR, Semirale AA, Zhang X. Osteoblast and osteocyte apoptosis associated with androgen action in bone: requirement of increased Bax/Bcl-2 ratio. Bone 2006; 38:637-51. [PMID: 16413235 DOI: 10.1016/j.bone.2005.10.029] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2005] [Revised: 10/07/2005] [Accepted: 10/14/2005] [Indexed: 01/13/2023]
Abstract
Both the number and the activity of osteoblasts are critical for normal bone growth and maintenance. Although a potential role for estrogen in protection of bone mass through inhibition of osteoblast apoptosis has been proposed, a function for androgen is much less clear. The aim of this study was to establish a direct role for androgen to influence osteoblast apoptosis both in vitro and in vivo. AR-MC3T3-E1 cells, with androgen receptor (AR) overexpression controlled by the type I collagen promoter, were treated with the non-aromatizable androgen 5alpha-dihydrotestosterone (DHT). Apoptosis was assessed by three different techniques including DNA fragmentation, caspase-3 activation, and changes in mitochondrial membrane potential. Transactivation of AR by DHT enhanced apoptosis while 17beta-estradiol (E(2)) treatment reduced apoptosis in both proliferating preosteoblasts and mature osteocyte-like cells. To explore mechanism, the apoptosis regulators Bcl-2 (antiapoptotic) and Bax (proapoptotic) were evaluated. Western analysis revealed that DHT decreased Bcl-2 resulting in a significantly increased Bax/Bcl-2 ratio. Regulation of Bcl-2 was post-transcriptional since bcl-2 mRNA levels were unaffected by DHT treatment. Furthermore, ubiquitination of Bcl-2 was increased and serine phosphorylation was reduced, consistent with inhibition of MAP kinase signaling by DHT. Increased Bax/Bcl-2 ratio was essential since either Bcl-2 overexpression or Bax downregulation by RNA interference (RNAi) partially abrogated or reversed DHT-enhanced osteoblastic apoptosis. In order to establish physiologic significance in vivo, AR-transgenic mice with AR overexpression in the osteoblast lineage and thus enhanced androgen sensitivity were characterized. In male AR-transgenic mice, increased osteoblast apoptosis was observed in vivo even in association with new bone formation. Thus, although estrogen can be antiapoptotic, androgen stimulates osteoblast and osteocyte apoptosis through an increased Bax/Bcl-2 ratio even in anabolic settings. These results identify a new mechanism for androgen regulation of osteoblast activity distinct from estrogen, and suggest that enhanced apoptosis can be associated with anabolic stimulation of new bone growth. Androgens thus play a distinct role in skeletal homeostasis.
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Affiliation(s)
- Kristine M Wiren
- Veterans Affairs Medical Center, 3181 SW U.S. Veterans Hospital Road, Portland, OR 97239, USA.
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