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Morana O, Wood W, Gregory CD. The Apoptosis Paradox in Cancer. Int J Mol Sci 2022; 23:ijms23031328. [PMID: 35163253 PMCID: PMC8836235 DOI: 10.3390/ijms23031328] [Citation(s) in RCA: 100] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 01/18/2022] [Accepted: 01/20/2022] [Indexed: 02/01/2023] Open
Abstract
Cancer growth represents a dysregulated imbalance between cell gain and cell loss, where the rate of proliferating mutant tumour cells exceeds the rate of those that die. Apoptosis, the most renowned form of programmed cell death, operates as a key physiological mechanism that limits cell population expansion, either to maintain tissue homeostasis or to remove potentially harmful cells, such as those that have sustained DNA damage. Paradoxically, high-grade cancers are generally associated with high constitutive levels of apoptosis. In cancer, cell-autonomous apoptosis constitutes a common tumour suppressor mechanism, a property which is exploited in cancer therapy. By contrast, limited apoptosis in the tumour-cell population also has the potential to promote cell survival and resistance to therapy by conditioning the tumour microenvironment (TME)-including phagocytes and viable tumour cells-and engendering pro-oncogenic effects. Notably, the constitutive apoptosis-mediated activation of cells of the innate immune system can help orchestrate a pro-oncogenic TME and may also effect evasion of cancer treatment. Here, we present an overview of the implications of cell death programmes in tumour biology, with particular focus on apoptosis as a process with "double-edged" consequences: on the one hand, being tumour suppressive through deletion of malignant or pre-malignant cells, while, on the other, being tumour progressive through stimulation of reparatory and regenerative responses in the TME.
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2
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Cabrera JTO, Makino A. Efferocytosis of vascular cells in cardiovascular disease. Pharmacol Ther 2022; 229:107919. [PMID: 34171333 PMCID: PMC8695637 DOI: 10.1016/j.pharmthera.2021.107919] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 05/21/2021] [Accepted: 06/03/2021] [Indexed: 12/20/2022]
Abstract
Cell death and the clearance of apoptotic cells are tightly regulated by various signaling molecules in order to maintain physiological tissue function and homeostasis. The phagocytic removal of apoptotic cells is known as the process of efferocytosis, and abnormal efferocytosis is linked to various health complications and diseases, such as cardiovascular disease, inflammatory diseases, and autoimmune diseases. During efferocytosis, phagocytic cells and/or apoptotic cells release signals, such as "find me" and "eat me" signals, to stimulate the phagocytic engulfment of apoptotic cells. Primary phagocytic cells are macrophages and dendritic cells; however, more recently, other neighboring cell types have also been shown to exhibit phagocytic character, including endothelial cells and fibroblasts, although they are comparatively slower in clearing dead cells. In this review, we focus on macrophage efferocytosis of vascular cells, such as endothelial cells, smooth muscle cells, fibroblasts, and pericytes, and its relation to the progression and development of cardiovascular disease. We also highlight the role of efferocytosis-related molecules and their contribution to the maintenance of vascular homeostasis.
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Affiliation(s)
- Jody Tori O Cabrera
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Ayako Makino
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, CA, USA.
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3
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A ligand-insensitive UNC5B splicing isoform regulates angiogenesis by promoting apoptosis. Nat Commun 2021; 12:4872. [PMID: 34381052 PMCID: PMC8358048 DOI: 10.1038/s41467-021-24998-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 07/16/2021] [Indexed: 12/12/2022] Open
Abstract
The Netrin-1 receptor UNC5B is an axon guidance regulator that is also expressed in endothelial cells (ECs), where it finely controls developmental and tumor angiogenesis. In the absence of Netrin-1, UNC5B induces apoptosis that is blocked upon Netrin-1 binding. Here, we identify an UNC5B splicing isoform (called UNC5B-Δ8) expressed exclusively by ECs and generated through exon skipping by NOVA2, an alternative splicing factor regulating vascular development. We show that UNC5B-Δ8 is a constitutively pro-apoptotic splicing isoform insensitive to Netrin-1 and required for specific blood vessel development in an apoptosis-dependent manner. Like NOVA2, UNC5B-Δ8 is aberrantly expressed in colon cancer vasculature where its expression correlates with tumor angiogenesis and poor patient outcome. Collectively, our data identify a mechanism controlling UNC5B’s necessary apoptotic function in ECs and suggest that the NOVA2/UNC5B circuit represents a post-transcriptional pathway regulating angiogenesis. UNC5B is a Netrin-1 receptor expressed in endothelial cells that in the absence of ligand induces apoptosis. Here the authors identify an UNC5B splicing isoform that is insensitive to the pro-survival ligand Netrin-1 and is required for apoptosis-dependent blood vessel development.
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4
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Castillo Ferrer C, Berthenet K, Ichim G. Apoptosis - Fueling the oncogenic fire. FEBS J 2021; 288:4445-4463. [PMID: 33179432 PMCID: PMC8451771 DOI: 10.1111/febs.15624] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 11/09/2020] [Indexed: 02/06/2023]
Abstract
Apoptosis, the most extensively studied form of programmed cell death, is essential for organismal homeostasis. Apoptotic cell death has widely been reported as a tumor suppressor mechanism. However, recent studies have shown that apoptosis exerts noncanonical functions and may paradoxically promote tumor growth and metastasis. The hijacking of apoptosis by cancer cells may arise at different levels, either via the interaction of apoptotic cells with their local or distant microenvironment, or through the abnormal pro-oncogenic roles of the main apoptosis effectors, namely caspases and mitochondria, particularly upon failed apoptosis. In this review, we highlight some of the recently described mechanisms by which apoptosis and these effectors may promote cancer aggressiveness. We believe that a better understanding of the noncanonical roles of apoptosis may be crucial for developing more efficient cancer therapies.
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Affiliation(s)
- Camila Castillo Ferrer
- Cancer Target and Experimental TherapeuticsInstitute for Advanced BiosciencesINSERM U1209CNRS UMR5309Grenoble Alpes UniversityFrance
- EPHEPSL Research UniversityParisFrance
| | - Kevin Berthenet
- Cancer Research Center of Lyon (CRCL) INSERM 1052CNRS 5286LyonFrance
- Cancer Cell Death Laboratory, part of LabEx DEVweCANUniversité de LyonFrance
| | - Gabriel Ichim
- Cancer Research Center of Lyon (CRCL) INSERM 1052CNRS 5286LyonFrance
- Cancer Cell Death Laboratory, part of LabEx DEVweCANUniversité de LyonFrance
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5
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Durdik M, Kosik P, Jakl L, Kozackova M, Markova E, Vigasova K, Beresova K, Jakubikova J, Horvathova E, Zastko L, Fekete M, Zavacka I, Pobijakova M, Belyaev I. Imaging flow cytometry and fluorescence microscopy in assessing radiation response in lymphocytes from umbilical cord blood and cancer patients. Cytometry A 2021; 99:1198-1208. [PMID: 34089242 DOI: 10.1002/cyto.a.24468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 05/31/2021] [Accepted: 06/01/2021] [Indexed: 12/28/2022]
Abstract
DNA double strand breaks (DSB) induced by ionizing radiation (IR) are usually measured using γH2AX/53BP1 DNA repair foci, that is considered to be the most sensitive assay for DSB analysis. While fluorescence microscopy (FM) is the gold standard for this analysis, imaging flow cytometry (IFC) may offer number of advantages such as lack of the fluorescence background, higher number of cells analyzed, and higher sensitivity in detection of DNA damage induced by IR at low doses. Along with appearance of γH2AX foci, the variable fraction of the cells exhibits homogeneously stained γH2AX signal resulting in so-called γH2AX pan-staining, which is believed to appear at early stages of apoptosis. Here, we investigated incidence of γH2AX pan-staining at different time points after irradiation with γ-rays using IFC and compared the obtained data with the data from FM. Appearance of γH2AX pan-staining during the apoptotic process was further analyzed by fluorescence-activated cell sorting (FACS) of cells at different stages of apoptosis and subsequent immunofluorescence analysis. Our results show that IFC was able to reveal dose dependence of pan-staining, while FM failed to detect all pan-staining cells. Moreover, we found that γH2AX pan-staining could be induced by therapeutic, but not low doses of γ-rays and correlate well with percentage of apoptotic cells was analyzed using flow cytometric Annexin-V/7-AAD assay. Further investigations showed that γH2AX pan-staining is formed in the early phases of apoptosis and remains until later stages of apoptotic process. Apoptotic DNA fragmentation as detected with comet assay using FM correlated with the percentage of live and late apoptotic/necrotic cells as analyzed by flow cytometry. Lastly, we successfully tested IFC for detection of γH2AX pan-staining and γH2AX/53BP1 DNA repair foci in lymphocyte of breast cancer patients after radiotherapy, which may be useful for assessing individual radiosensitivity in a clinically relevant cohort of patients.
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Affiliation(s)
- Matus Durdik
- Department of Radiobiology, Cancer Research Institute, Biomedical Research Center, University Science Park for Biomedicine, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Pavol Kosik
- Department of Radiobiology, Cancer Research Institute, Biomedical Research Center, University Science Park for Biomedicine, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Lukas Jakl
- Department of Radiobiology, Cancer Research Institute, Biomedical Research Center, University Science Park for Biomedicine, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Maria Kozackova
- Department of Radiobiology, Cancer Research Institute, Biomedical Research Center, University Science Park for Biomedicine, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Eva Markova
- Department of Radiobiology, Cancer Research Institute, Biomedical Research Center, University Science Park for Biomedicine, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Katarina Vigasova
- Department of Radiobiology, Cancer Research Institute, Biomedical Research Center, University Science Park for Biomedicine, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Katarina Beresova
- Department of Radiobiology, Cancer Research Institute, Biomedical Research Center, University Science Park for Biomedicine, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Jana Jakubikova
- Department of Tumor Immunology, Cancer Research Institute, Biomedical Research Center, University Science Park for Biomedicine, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Eva Horvathova
- Department of Genetics, Cancer Research Institute, Biomedical Research Center, University Science Park for Biomedicine, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Lucian Zastko
- Department of Radiobiology, Cancer Research Institute, Biomedical Research Center, University Science Park for Biomedicine, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Marta Fekete
- Department of Radiation Oncology, National Cancer Institute, Bratislava, Slovakia
| | - Ingrid Zavacka
- Department of Radiation Oncology, National Cancer Institute, Bratislava, Slovakia
| | - Margita Pobijakova
- Department of Radiation Oncology, National Cancer Institute, Bratislava, Slovakia
| | - Igor Belyaev
- Department of Radiobiology, Cancer Research Institute, Biomedical Research Center, University Science Park for Biomedicine, Slovak Academy of Sciences, Bratislava, Slovakia
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6
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Mike JK, Ferriero DM. Efferocytosis Mediated Modulation of Injury after Neonatal Brain Hypoxia-Ischemia. Cells 2021; 10:1025. [PMID: 33925299 PMCID: PMC8146813 DOI: 10.3390/cells10051025] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/22/2021] [Accepted: 04/23/2021] [Indexed: 02/06/2023] Open
Abstract
Neonatal brain hypoxia-ischemia (HI) is a leading cause of morbidity and long-term disabilities in children. While we have made significant progress in describing HI mechanisms, the limited therapies currently offered for HI treatment in the clinical setting stress the importance of discovering new targetable pathways. Efferocytosis is an immunoregulatory and homeostatic process of clearance of apoptotic cells (AC) and cellular debris, best described in the brain during neurodevelopment. The therapeutic potential of stimulating defective efferocytosis has been recognized in neurodegenerative diseases. In this review, we will explore the involvement of efferocytosis after a stroke and HI as a promising target for new HI therapies.
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Affiliation(s)
- Jana Krystofova Mike
- Department of Pediatrics, University of California San Francisco, San Francisco, CA 94143, USA;
| | - Donna Marie Ferriero
- Department of Pediatrics, University of California San Francisco, San Francisco, CA 94143, USA;
- Department of Neurology Weill Institute for Neurosciences, University of California San Francisco, San Francisco, CA 94143, USA
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7
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Jiang MJ, Gu DN, Dai JJ, Huang Q, Tian L. Dark Side of Cytotoxic Therapy: Chemoradiation-Induced Cell Death and Tumor Repopulation. Trends Cancer 2020; 6:419-431. [PMID: 32348737 DOI: 10.1016/j.trecan.2020.01.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 01/25/2020] [Accepted: 01/27/2020] [Indexed: 12/20/2022]
Abstract
Accelerated tumor repopulation following chemoradiation is often observed in the clinic, but the underlying mechanisms remain unclear. In recent years, dying cells caused by chemoradiation have attracted much attention, and they may manifest diverse forms of cell death and release complex factors and thus orchestrate tumor repopulation cascades. Dying cells potentiate the survival of residual living tumor cells, remodel the tumor microenvironment, boost cell proliferation, and accelerate cancer cell metastasis. Moreover, dying cells also mediate the side effects of chemoradiation. These findings suggest more caution when weighing the benefits of cytotoxic therapy and the need to accordingly develop new strategies for cancer treatment.
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Affiliation(s)
- Ming-Jie Jiang
- Institute of Translational Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201620, China; Shanghai Key Laboratory of Pancreatic Diseases, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201620, China
| | - Dian-Na Gu
- Shanghai Key Laboratory of Pancreatic Diseases, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201620, China; Department of Chemoradiotherapy, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, China
| | - Juan-Juan Dai
- Shanghai Key Laboratory of Pancreatic Diseases, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201620, China
| | - Qian Huang
- Shanghai Key Laboratory of Pancreatic Diseases, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201620, China; Cancer Center, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201620, China
| | - Ling Tian
- Institute of Translational Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201620, China; Shanghai Key Laboratory of Pancreatic Diseases, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 201620, China; Department of Central Laboratory, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China.
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8
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Levin M, Selberg J, Rolandi M. Endogenous Bioelectrics in Development, Cancer, and Regeneration: Drugs and Bioelectronic Devices as Electroceuticals for Regenerative Medicine. iScience 2019; 22:519-533. [PMID: 31837520 PMCID: PMC6920204 DOI: 10.1016/j.isci.2019.11.023] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 10/15/2019] [Accepted: 11/12/2019] [Indexed: 12/21/2022] Open
Abstract
A major frontier in the post-genomic era is the investigation of the control of coordinated growth and three-dimensional form. Dynamic remodeling of complex organs in regulative embryogenesis, regeneration, and cancer reveals that cells and tissues make decisions that implement complex anatomical outcomes. It is now essential to understand not only the genetics that specifies cellular hardware but also the physiological software that implements tissue-level plasticity and robust morphogenesis. Here, we review recent discoveries about the endogenous mechanisms of bioelectrical communication among non-neural cells that enables them to cooperate in vivo. We discuss important advances in bioelectronics, as well as computational and pharmacological tools that are enabling the taming of biophysical controls toward applications in regenerative medicine and synthetic bioengineering.
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Affiliation(s)
- Michael Levin
- Allen Discovery Center at Tufts University, Medford, MA 02155, USA.
| | - John Selberg
- Electrical and Computer Engineering Department, University of California, Santa Cruz, CA 95064, USA
| | - Marco Rolandi
- Electrical and Computer Engineering Department, University of California, Santa Cruz, CA 95064, USA
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9
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Tajbakhsh A, Rezaee M, Kovanen PT, Sahebkar A. Efferocytosis in atherosclerotic lesions: Malfunctioning regulatory pathways and control mechanisms. Pharmacol Ther 2018; 188:12-25. [DOI: 10.1016/j.pharmthera.2018.02.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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10
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Feng L, Vujicic S, Dietrich ME, Litbarg N, Setty S, Antoni A, Rauch J, Levine JS. Repeated exposure of epithelial cells to apoptotic cells induces the specific selection of an adaptive phenotype: Implications for tumorigenesis. J Biol Chem 2018; 293:10245-10263. [PMID: 29769319 DOI: 10.1074/jbc.ra117.001290] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 05/08/2018] [Indexed: 11/06/2022] Open
Abstract
The consequences of apoptosis extend beyond the mere death of the cell. We have shown that receptor-mediated recognition of apoptotic target cells by viable kidney proximal tubular epithelial cells (PTECs) inhibits PTEC proliferation, growth, and survival. Here, we tested the hypothesis that continual exposure to apoptotic targets can induce a phenotypic change in responding PTECs, as in other instances of natural selection. In particular, we demonstrate that repeated exposure to apoptotic targets leads to emergence of a PTEC line (denoted BU.MPTSEL) resistant to apoptotic target-induced death. Resistance is exquisitely specific. Not only are BU.MPTSEL responders fully resistant to apoptotic target-induced death (∼85% survival versus <10% survival of nonselected cells) but do so while retaining sensitivity to all other target-induced responses, including inhibition of proliferation and growth. Moreover, the resistance of BU.MPTSEL responders is specific to target-induced apoptosis, as apoptosis in response to other suicidal stimuli occurs normally. Comparison of the signaling events induced by apoptotic target exposure in selected versus nonselected responders indicated that the acquired resistance of BU.MPTSEL cells lies in a regulatory step affecting the generation of the pro-apoptotic protein, truncated BH3 interacting-domain death agonist (tBID), most likely at the level of BID cleavage by caspase-8. This specific adaptation has especial relevance for cancer, in which the prominence and persistence of cell death entail magnification of the post-mortem effects of apoptotic cells. Just as cancer cells acquire specific resistance to chemotherapeutic agents, we propose that cancer cells may also adapt to their ongoing exposure to apoptotic targets.
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Affiliation(s)
- Lanfei Feng
- From the Section of Nephrology, Department of Medicine, and.,the Section of Nephrology, Department of Medicine, Jesse Brown Veterans Affairs Hospital, Chicago, Illinois 60612
| | - Snezana Vujicic
- From the Section of Nephrology, Department of Medicine, and.,the Section of Nephrology, Department of Medicine, Jesse Brown Veterans Affairs Hospital, Chicago, Illinois 60612
| | | | - Natalia Litbarg
- From the Section of Nephrology, Department of Medicine, and.,the Section of Nephrology, Department of Medicine, Jesse Brown Veterans Affairs Hospital, Chicago, Illinois 60612
| | - Suman Setty
- Department of Pathology, University of Illinois, Chicago, Illinois 60612
| | - Angelika Antoni
- the Department of Biology, Kutztown University of Pennsylvania, Kutztown, Pennsylvania 19530, and
| | - Joyce Rauch
- the Division of Rheumatology, Department of Medicine, Research Institute of the McGill University Health Centre, Montreal, Quebec H4A 3J1, Canada
| | - Jerrold S Levine
- From the Section of Nephrology, Department of Medicine, and .,the Section of Nephrology, Department of Medicine, Jesse Brown Veterans Affairs Hospital, Chicago, Illinois 60612
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11
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Abstract
Within an organism, environmental stresses can trigger cell death, particularly apoptotic cell death. Apoptotic cells, themselves, are potent regulators of their cellular environment, involved primarily in effecting homeostatic control. Tumors, especially, exist in a dynamic balance of cell proliferation and cell death. This special feature of the tumorous microenvironment—namely, the prominence and persistence of cell death—necessarily entails a magnification of the extrinsic, postmortem effects of dead cells. In both normal and malignant tissues, apoptotic regulation is exerted through immune as well as non-immune mechanisms. Apoptotic cells suppress the repertoire of immune reactivities, both by attenuating innate (especially inflammatory) responses and by abrogating adaptive responses. In addition, apoptotic cells modulate multiple vital cell activities, including survival, proliferation (cell number), and growth (cell size). While the microenvironment of the tumor may contribute to apoptosis, the postmortem effects of apoptotic cells feature prominently in the reciprocal acclimatization between the tumor and its environment. In much the same way that pathogens evade the host’s defenses through exploitation of key aspects of innate and adaptive immunity, cancer cells subvert several normal homeostatic processes, in particular wound healing and organ regeneration, to transform and overtake their environment. In understanding this subversion, it is crucial to view a tumor not simply as a clone of malignant cells, but rather as a complex and highly organized structure in which there exists a multidirectional flow of information between the cancer cells themselves and the multiple other cell types and extracellular matrix components of which the tumor is comprised. Apoptotic cells, therefore, have the unfortunate consequence of facilitating tumorigenesis and tumor survival.
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Affiliation(s)
- David S Ucker
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago, IL, United States
| | - Jerrold S Levine
- Department of Medicine, Division of Nephrology, University of Illinois College of Medicine, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, United States
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12
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Sarode GS, Sarode SC, Maniyar N, Sharma NK, Patil S. Carcinogenesis-relevant biological events in the pathophysiology of the efferocytosis phenomenon. Oncol Rev 2017; 11:343. [PMID: 29285321 PMCID: PMC5733395 DOI: 10.4081/oncol.2017.343] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 12/01/2017] [Indexed: 01/05/2023] Open
Abstract
The effective removal of cells undergoing programmed cell death, which is referred to as efferocytosis, prevents the leakage of intracellular contents into the surrounding tissue, which could lead to tissue damage and inflammation. Efferocytosis involves a coordinated orchestration of multiple steps that lead to a swift, coherent and immunologically silent removal of dying cells. The release of wound healing cytokines, which resolve inflammation and enhance tissue repair, is an important feature of efferocytosis. However, in addition to the healing cytokines released during efferocytosis, the immunosuppressive action of cytokines promotes the tumor microenvironment, enhances the motility of cancer cells and promotes the evasion of antitumor immunity. The aim of the present review was to comprehensively discuss the efferocytosis phenomenon, the important players associated with this process and their role in cancer-related biological events.
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Affiliation(s)
- Gargi Sachin Sarode
- Department of Oral Pathology and Microbiology, Dr. D. Y. Patil Dental College and Hospital, Dr. D.Y. Patil Vidyapeeth, Sant-Tukaram Nagar, Pimpri, Pune, Maharashtra, India
| | - Sachin C Sarode
- Department of Oral Pathology and Microbiology, Dr. D. Y. Patil Dental College and Hospital, Dr. D.Y. Patil Vidyapeeth, Sant-Tukaram Nagar, Pimpri, Pune, Maharashtra, India
| | - Nikunj Maniyar
- Department of Oral Pathology and Microbiology, Dr. D. Y. Patil Dental College and Hospital, Dr. D.Y. Patil Vidyapeeth, Sant-Tukaram Nagar, Pimpri, Pune, Maharashtra, India
| | - Nilesh Kumar Sharma
- Cancer and Translational Research Lab, Dr. D.Y. Patil Biotechnology & Bioinformatics Institute, Dr. D.Y. Patil Vidyapeeth, Pune, Maharashtra, India
| | - Shankargouda Patil
- Department of Oral and Maxillofacial Surgery and Diagnostic Sciences, Division of Oral Pathology, College of Dentistry, Jazan University, Jazan, Saudi Arabia
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13
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Gregory CD, Ford CA, Voss JJLP. Microenvironmental Effects of Cell Death in Malignant Disease. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 930:51-88. [PMID: 27558817 DOI: 10.1007/978-3-319-39406-0_3] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Although apoptosis is well recognized as a cell death program with clear anticancer roles, accumulating evidence linking apoptosis with tissue repair and regeneration indicates that its relationship with malignant disease is more complex than previously thought. Here we review how the responses of neighboring cells in the microenvironment of apoptotic tumor cells may contribute to the cell birth/cell death disequilibrium that provides the basis for cancerous tissue emergence and growth. We describe the bioactive properties of apoptotic cells and consider, in particular, how apoptosis of tumor cells can engender a range of responses including pro-oncogenic signals having proliferative, angiogenic, reparatory, and immunosuppressive features. Drawing on the parallels between wound healing, tissue regeneration and cancer, we propose the concept of the "onco-regenerative niche," a cell death-driven generic network of tissue repair and regenerative mechanisms that are hijacked in cancer. Finally, we consider how the responses to cell death in tumors can be targeted to provide more effective and long-lasting therapies.
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Affiliation(s)
- Christopher D Gregory
- MRC Centre for Inflammation Research, University of Edinburgh Queen's Medical Research Institute, Edinburgh, EH16 4TJ, UK.
| | - Catriona A Ford
- MRC Centre for Inflammation Research, University of Edinburgh Queen's Medical Research Institute, Edinburgh, EH16 4TJ, UK
| | - Jorine J L P Voss
- MRC Centre for Inflammation Research, University of Edinburgh Queen's Medical Research Institute, Edinburgh, EH16 4TJ, UK
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14
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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: 45] [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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15
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Abstract
Apoptosis is a carefully choreographed process of cellular self-destruction in the absence of inflammation. During the death process, apoptotic cells actively communicate with their environment, signaling to both their immediate neighbors as well as distant sentinels. Some of these signals direct the anti-inflammatory immune response, instructing specific subsets of phagocytes to participate in the limited and careful clearance of dying cellular debris. These immunomodulatory signals can also regulate the activation state of the engulfing phagocytes. Other signals derived from apoptotic cells contribute to tissue growth control with the common goal of maintaining tissue integrity. Derangements in these growth control signals during prolonged apoptosis can lead to excessive cell loss or proliferation. Here, we highlight some of the most intriguing signals produced by apoptotic cells during the course of normal development as well as during physiological disturbances such as atherosclerosis and cancer.
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16
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Willems JJLP, Arnold BP, Gregory CD. Sinister self-sacrifice: the contribution of apoptosis to malignancy. Front Immunol 2014; 5:299. [PMID: 25071762 PMCID: PMC4081761 DOI: 10.3389/fimmu.2014.00299] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 06/13/2014] [Indexed: 01/02/2023] Open
Affiliation(s)
- Jorine J L P Willems
- MRC Centre for Inflammation Research, Queen's Medical Research Institute, The University of Edinburgh , Edinburgh , UK
| | - Benjamin P Arnold
- MRC Centre for Inflammation Research, Queen's Medical Research Institute, The University of Edinburgh , Edinburgh , UK
| | - Christopher D Gregory
- MRC Centre for Inflammation Research, Queen's Medical Research Institute, The University of Edinburgh , Edinburgh , UK
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17
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Yuan G, Zhang L, Yang G, Yang J, Wan C, Zhang L, Song G, Chen S, Chen Z. The distribution and ultrastructure of the forming blood capillaries and the effect of apoptosis on vascularization in mouse embryonic molar mesenchyme. Cell Tissue Res 2014; 356:137-45. [PMID: 24477797 DOI: 10.1007/s00441-013-1785-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 12/05/2013] [Indexed: 11/30/2022]
Abstract
Vascularization is essential for organ and tissue development. Teeth develop through interactions between epithelium and mesenchyme. The developing capillaries in the enamel organ, the dental epithelial structure, occur simultaneously by mechanisms of vasculogenesis and angiogenesis at the onset of dentinogenesis. The vascular neoformation in the dental mesenchyme has been reported to start from the cap stage. However, the mechanisms of vascularization in the dental mesenchyme remain unknown. In the hope of understanding the mechanisms of the formation of dental mesenchymal vasculature, mouse lower molar germs from embryonic day (E) 13.5 to E16.5 were processed for immunostaining of CD31 and CD34, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) and transmission electron microscopy (TEM). In addition, the role of apoptosis for the vascularization in dental mesenchyme was examined by in vitro culture of E14.0 lower molars in the presence of the apoptosis inhibitor (z-VAD-fmk) and a subsequent subrenal culture. Our results showed that CD31- and CD34-positive cells progressively entered the central part of the dental papilla from the peridental mesenchyme. For TEM, angioblasts, young capillaries with thick endothelium and endothelial cells containing vacuoles were observed in peripheral dental mesenchyme, suggesting vasculogenesis was taking place. The presence of lateral sprouting, cytoplasmic filopodia and transluminal bridges in the dental papilla suggested angiogenesis was also occurring. Inhibition of apoptosis delayed the angiogenic vascularization of the dental papilla. Therefore, these data demonstrated that molar mesenchyme is progressively vascularized by mechanisms of both vasculogenesis and angiogenesis and apoptosis partially contributes to the vascularization of the dental papilla.
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Affiliation(s)
- Guohua Yuan
- Key Laboratory of Oral Biomedicine of Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, Hubei, People's Republic of China, 430079
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18
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Stock C, Ludwig FT, Hanley PJ, Schwab A. Roles of ion transport in control of cell motility. Compr Physiol 2013; 3:59-119. [PMID: 23720281 DOI: 10.1002/cphy.c110056] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cell motility is an essential feature of life. It is essential for reproduction, propagation, embryonic development, and healing processes such as wound closure and a successful immune defense. If out of control, cell motility can become life-threatening as, for example, in metastasis or autoimmune diseases. Regardless of whether ciliary/flagellar or amoeboid movement, controlled motility always requires a concerted action of ion channels and transporters, cytoskeletal elements, and signaling cascades. Ion transport across the plasma membrane contributes to cell motility by affecting the membrane potential and voltage-sensitive ion channels, by inducing local volume changes with the help of aquaporins and by modulating cytosolic Ca(2+) and H(+) concentrations. Voltage-sensitive ion channels serve as voltage detectors in electric fields thus enabling galvanotaxis; local swelling facilitates the outgrowth of protrusions at the leading edge while local shrinkage accompanies the retraction of the cell rear; the cytosolic Ca(2+) concentration exerts its main effect on cytoskeletal dynamics via motor proteins such as myosin or dynein; and both, the intracellular and the extracellular H(+) concentration modulate cell migration and adhesion by tuning the activity of enzymes and signaling molecules in the cytosol as well as the activation state of adhesion molecules at the cell surface. In addition to the actual process of ion transport, both, channels and transporters contribute to cell migration by being part of focal adhesion complexes and/or physically interacting with components of the cytoskeleton. The present article provides an overview of how the numerous ion-transport mechanisms contribute to the various modes of cell motility.
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Affiliation(s)
- Christian Stock
- Institute of Physiology II, University of Münster, Münster, Germany.
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19
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Adams DS, Levin M. Endogenous voltage gradients as mediators of cell-cell communication: strategies for investigating bioelectrical signals during pattern formation. Cell Tissue Res 2013; 352:95-122. [PMID: 22350846 PMCID: PMC3869965 DOI: 10.1007/s00441-012-1329-4] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 01/12/2012] [Indexed: 01/07/2023]
Abstract
Alongside the well-known chemical modes of cell-cell communication, we find an important and powerful system of bioelectrical signaling: changes in the resting voltage potential (Vmem) of the plasma membrane driven by ion channels, pumps and gap junctions. Slow Vmem changes in all cells serve as a highly conserved, information-bearing pathway that regulates cell proliferation, migration and differentiation. In embryonic and regenerative pattern formation and in the disorganization of neoplasia, bioelectrical cues serve as mediators of large-scale anatomical polarity, organ identity and positional information. Recent developments have resulted in tools that enable a high-resolution analysis of these biophysical signals and their linkage with upstream and downstream canonical genetic pathways. Here, we provide an overview for the study of bioelectric signaling, focusing on state-of-the-art approaches that use molecular physiology and developmental genetics to probe the roles of bioelectric events functionally. We highlight the logic, strategies and well-developed technologies that any group of researchers can employ to identify and dissect ionic signaling components in their own work and thus to help crack the bioelectric code. The dissection of bioelectric events as instructive signals enabling the orchestration of cell behaviors into large-scale coherent patterning programs will enrich on-going work in diverse areas of biology, as biophysical factors become incorporated into our systems-level understanding of cell interactions.
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Affiliation(s)
- Dany S Adams
- Department of Biology, and Center for Regenerative and Developmental Biology, Tufts University, 200 Boston Ave, Medford, MA 02155, USA
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20
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Gregory CD. Inflammation and cancer revisited: an hypothesis on the oncogenic potential of the apoptotic tumor cell. Autoimmunity 2013; 46:312-6. [PMID: 23320865 DOI: 10.3109/08916934.2012.755961] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
It is well known that an important property of apoptosis is the prevention of cancer. However, it is becoming increasingly clear that apoptotic cells have the capacity to activate reparative and regenerative responses, which have the potential to make significant impact on pathological processes underlying autoimmune disease and cancer. Those properties of apoptotic cells that influence their immediate microenvironment are reviewed here in the context of cancer progression and treatment.
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Affiliation(s)
- Christopher D Gregory
- MRC Centre for Inflammation Research, University of Edinburgh, Queens Medical Research Institute, Edinburgh, United Kingdom.
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21
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Van Vré EA, Ait-Oufella H, Tedgui A, Mallat Z. Apoptotic Cell Death and Efferocytosis in Atherosclerosis. Arterioscler Thromb Vasc Biol 2012; 32:887-93. [DOI: 10.1161/atvbaha.111.224873] [Citation(s) in RCA: 138] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Apoptotic cell death is an important feature of atherosclerotic plaques, and it seems to exert both beneficial and detrimental effects depending on the cell type and plaque stage. Because late apoptotic cells can launch proatherogenic inflammatory responses, adequate engulfment of apoptotic cells (efferocytosis) by macrophages is important to withstand atherosclerosis progression. Several efferocytosis systems, composed of different phagocytic receptors, apoptotic ligands, and bridging molecules, can be distinguished. Because phagocytes in atherosclerotic plaques are very much solicited, a fully operative efferocytosis system seems to be an absolute requisite. Indeed, recent studies demonstrate that deletion of just 1 of the efferocytosis pathways aggravates atherosclerosis. This review discusses the role of apoptosis in atherosclerosis and general mechanisms of efferocytosis, to end with indirect and direct indications of the significance of effective efferocytosis in atherosclerosis.
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Affiliation(s)
- Emily A. Van Vré
- From the Institut National de la Santé et de la Recherche Médicale, Paris Cardiovascular Research Center, Paris, France (E.A.V.V., H.A.-O., A.T., Z.M.); Assistance Publique–Hôpitaux de Paris, Saint-Antoine Hospital, Paris, France (H.A.-O.); Department of Medicine, Division of Cardiovascular Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom (Z.M.)
| | - Hafid Ait-Oufella
- From the Institut National de la Santé et de la Recherche Médicale, Paris Cardiovascular Research Center, Paris, France (E.A.V.V., H.A.-O., A.T., Z.M.); Assistance Publique–Hôpitaux de Paris, Saint-Antoine Hospital, Paris, France (H.A.-O.); Department of Medicine, Division of Cardiovascular Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom (Z.M.)
| | - Alain Tedgui
- From the Institut National de la Santé et de la Recherche Médicale, Paris Cardiovascular Research Center, Paris, France (E.A.V.V., H.A.-O., A.T., Z.M.); Assistance Publique–Hôpitaux de Paris, Saint-Antoine Hospital, Paris, France (H.A.-O.); Department of Medicine, Division of Cardiovascular Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom (Z.M.)
| | - Ziad Mallat
- From the Institut National de la Santé et de la Recherche Médicale, Paris Cardiovascular Research Center, Paris, France (E.A.V.V., H.A.-O., A.T., Z.M.); Assistance Publique–Hôpitaux de Paris, Saint-Antoine Hospital, Paris, France (H.A.-O.); Department of Medicine, Division of Cardiovascular Medicine, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom (Z.M.)
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22
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Smith BA, Xiao S, Wolter W, Wheeler J, Suckow MA, Smith BD. In vivo targeting of cell death using a synthetic fluorescent molecular probe. Apoptosis 2011; 16:722-31. [PMID: 21499791 DOI: 10.1007/s10495-011-0601-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
A synthetic, near-infrared, fluorescent probe, named PSS-794 was assessed for its ability to detect cell death in two animal models. The molecular probe contains a zinc(II)-dipicolylamine (Zn(2+)-DPA) affinity ligand that selectively targets exposed phosphatidylserine on the surface of dead and dying cells. The first animal model used rats that were treated with dexamethasone to induce thymic atrophy. Ex vivo fluorescence imaging and histological analysis of excised organs showed thymus uptake of PSS-794 was four times higher than a control fluorophore that lacked the Zn(2+)-DPA affinity ligand. In addition, the presence of PSS-794 produced a delayed and higher build up of dead and dying cells in the rat thymus. The second animal model employed focal beam radiation to induce cell death in tumor-bearing rats. Whole-body and ex vivo imaging showed that the amount of PSS-794 in a radiation-treated tumor was almost twice that in a non-treated tumor. The results indicate that PSS-794 may be useful for preclinical optical detection of tumor cell death due to therapy.
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Affiliation(s)
- Bryan A Smith
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
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23
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Devitt A, Marshall LJ. The innate immune system and the clearance of apoptotic cells. J Leukoc Biol 2011; 90:447-57. [DOI: 10.1189/jlb.0211095] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
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24
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Abstract
The apoptosis program of physiological cell death elicits a range of non-phlogistic homeostatic mechanisms-"recognition, response and removal"-that regulate the microenvironments of normal and diseased tissues via multiple modalities operating over short and long distances. The molecular mechanisms mediate intercellular signaling through direct contact with neighboring cells, release of soluble factors and production of membrane-delimited fragments (apoptotic bodies, blebs and microparticles) that allow for interaction with host cells over long distances. These processes effect the selective recruitment of mononuclear phagocytes and the specific activation of both phagocytic and non-phagocytic cells. While much evidence is available concerning the mechanisms underlying the recognition and responses of phagocytes that culminate in the engulfment and removal of apoptotic cell bodies, relatively little is yet known about the non-phagocytic cellular responses to the apoptosis program. These responses regulate inflammatory and immune cell activation as well as cell fate decisions of proliferation, differentiation and death. Here, we review current knowledge of these processes, considering especially how apoptotic cells condition the microenvironments of normal and malignant tissues. We also discuss how apoptotic cells that persist in the absence of phagocytic clearance exert inhibitory effects over their viable neighbors, paying particular attention to the specific case of cell cultures and highlighting how new cell-corpse-clearance devices-Dead-Cert Nanoparticles-can significantly improve the efficacy of cell cultures through effective removal of non-viable cells in the absence of phagocytes in vitro.
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25
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Gregory CD, Pound JD. Cell death in the neighbourhood: direct microenvironmental effects of apoptosis in normal and neoplastic tissues. J Pathol 2010; 223:177-94. [PMID: 21125674 DOI: 10.1002/path.2792] [Citation(s) in RCA: 149] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Revised: 09/12/2010] [Accepted: 09/21/2010] [Indexed: 12/24/2022]
Abstract
Here we consider the impact of the physiological cell-death programme on normal tissue homeostasis and on disease pathogenesis, with particular reference to evolution and progression of neoplasia. We seek to describe the direct contributions played by apoptosis in creating the microenvironments of normal and malignant tissues and to discuss the molecular mechanisms underlying the elements of the '3Rs' that define the meaning of apoptosis: recognition, response, and removal. Apoptotic cells elicit responses in other cell types-both phagocytic and non-phagocytic-through short- and long-range signalling modes that range from direct contact to intercellular communication via membrane-bound microparticles. Such cellular responses include migration, proliferation, and differentiation, as well as production of immunomodulatory and anti-inflammatory mediators together with, in the case of phagocytes, engulfment, and breakdown of apoptotic cells. In normal tissues, the removal of apoptotic cells is rapid and typically non-phlogistic. We discuss the importance of this clearance process in tissue homeostasis and the consequences of its failure in disease pathogenesis. Using the typical cell culture environment in vitro as an illustrative example in which apoptosis occurs commonly in the absence of the removal mechanisms, we also discuss the inhibitory effects of persistent apoptotic cells on their otherwise viable neighbours. Since apoptosis is a common and sustained event in high-grade malignancies, we hypothesize on its purposeful role in conditioning the tumour microenvironment. We propose that apoptosis subserves several pro-tumour functions-trophic, anti-inflammatory, and immunomodulatory-and we identify strategies targeting host responses to apoptotic cells as promising modes of future therapies that could be applied to multiple cancer types in which tumour-cell apoptosis is active.
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Affiliation(s)
- Christopher D Gregory
- MRC Centre for Inflammation Research, University of Edinburgh, Queens Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK.
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26
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Rizzo MT, Leaver HA. Brain Endothelial Cell Death: Modes, Signaling Pathways, and Relevance to Neural Development, Homeostasis, and Disease. Mol Neurobiol 2010; 42:52-63. [DOI: 10.1007/s12035-010-8132-6] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Accepted: 04/05/2010] [Indexed: 12/31/2022]
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27
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Contribution of Candida albicans cell wall components to recognition by and escape from murine macrophages. Infect Immun 2010; 78:1650-8. [PMID: 20123707 DOI: 10.1128/iai.00001-10] [Citation(s) in RCA: 178] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The pathogenicity of the opportunistic human fungal pathogen Candida albicans depends on its ability to escape destruction by the host immune system. Using mutant strains that are defective in cell surface glycosylation, cell wall protein synthesis, and yeast-hypha morphogenesis, we have investigated three important aspects of C. albicans innate immune interactions: phagocytosis by primary macrophages and macrophage cell lines, hyphal formation within macrophage phagosomes, and the ability to escape from and kill macrophages. We show that cell wall glycosylation is critically important for the recognition and ingestion of C. albicans by macrophages. Phagocytosis was significantly reduced for mutants deficient in phosphomannan biosynthesis (mmn4Delta, pmr1Delta, and mnt3 mnt5Delta), whereas O- and N-linked mannan defects (mnt1Delta mnt2Delta and mns1Delta) were associated with increased ingestion, compared to the parent wild-type strains and genetically complemented controls. In contrast, macrophage uptake of mutants deficient in cell wall proteins such as adhesins (ece1Delta, hwp1Delta, and als3Delta) and yeast-locked mutants (clb2Delta, hgc1Delta, cph1Delta, efg1Delta, and efg1Delta cph1Delta), was similar to that observed for wild-type C. albicans. Killing of macrophages was abrogated in hypha-deficient strains, significantly reduced in all glycosylation mutants, and comparable to wild type in cell wall protein mutants. The diminished ability of glycosylation mutants to kill macrophages was not a consequence of impaired hyphal formation within macrophage phagosomes. Therefore, cell wall composition and the ability to undergo yeast-hypha morphogenesis are critical determinants of the macrophage's ability to ingest and process C. albicans.
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28
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Fadeel B, Xue D. The ins and outs of phospholipid asymmetry in the plasma membrane: roles in health and disease. Crit Rev Biochem Mol Biol 2009; 44:264-77. [PMID: 19780638 DOI: 10.1080/10409230903193307] [Citation(s) in RCA: 288] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A common feature of all eukaryotic membranes is the non-random distribution of different lipid species in the lipid bilayer (lipid asymmetry). Lipid asymmetry provides the two sides of the plasma membrane with different biophysical properties and influences numerous cellular functions. Alteration of lipid asymmetry plays a prominent role during cell fusion, activation of the coagulation cascade, and recognition and removal of apoptotic cell corpses by macrophages (programmed cell clearance). Here we discuss the origin and maintenance of phospholipid asymmetry, based on recent studies in mammalian systems as well as in Caenhorhabditis elegans and other model organisms, along with emerging evidence for a conserved role of mitochondria in the loss of lipid asymmetry during apoptosis. The functional significance of lipid asymmetry and its disruption during health and disease is also discussed.
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Affiliation(s)
- Bengt Fadeel
- Division of Molecular Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden.
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29
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Sundelacruz S, Levin M, Kaplan DL. Role of membrane potential in the regulation of cell proliferation and differentiation. Stem Cell Rev Rep 2009; 5:231-46. [PMID: 19562527 PMCID: PMC10467564 DOI: 10.1007/s12015-009-9080-2] [Citation(s) in RCA: 319] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Accepted: 06/07/2009] [Indexed: 12/11/2022]
Abstract
Biophysical signaling, an integral regulator of long-term cell behavior in both excitable and non-excitable cell types, offers enormous potential for modulation of important cell functions. Of particular interest to current regenerative medicine efforts, we review several examples that support the functional role of transmembrane potential (V(mem)) in the regulation of proliferation and differentiation. Interestingly, distinct V(mem) controls are found in many cancer cell and precursor cell systems, which are known for their proliferative and differentiation capacities, respectively. Collectively, the data demonstrate that bioelectric properties can serve as markers for cell characterization and can control cell mitotic activity, cell cycle progression, and differentiation. The ability to control cell functions by modulating bioelectric properties such as V(mem) would be an invaluable tool for directing stem cell behavior toward therapeutic goals. Biophysical properties of stem cells have only recently begun to be studied and are thus in need of further characterization. Understanding the molecular and mechanistic basis of biophysical regulation will point the way toward novel ways to rationally direct cell functions, allowing us to capitalize upon the potential of biophysical signaling for regenerative medicine and tissue engineering.
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Affiliation(s)
- Sarah Sundelacruz
- Department of Biomedical Engineering, Tufts University, 4 Colby St., Medford, MA 02155, USA
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30
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Gregory CD, Pound JD, Devitt A, Wilson-Jones M, Ray P, Murray RJ. Inhibitory effects of persistent apoptotic cells on monoclonal antibody production in vitro: simple removal of non-viable cells improves antibody productivity by hybridoma cells in culture. MAbs 2009; 1:370-6. [PMID: 20068393 DOI: 10.4161/mabs.1.4.9124] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Cells undergoing apoptosis in vivo are rapidly detected and cleared by phagocytes. Swift recognition and removal of apoptotic cells is important for normal tissue homeostasis and failure in the underlying clearance mechanisms has pathological consequences associated with inflammatory and auto-immune diseases. Cell cultures in vitro usually lack the capacity for removal of non-viable cells because of the absence of phagocytes and, as such, fail to emulate the healthy in vivo micro-environment from which dead cells are absent. While a key objective in cell culture is to maintain viability at maximal levels, cell death is unavoidable and non-viable cells frequently contaminate cultures in significant numbers. Here we show that the presence of apoptotic cells in monoclonal antibody-producing hybridoma cultures has markedly detrimental effects on antibody productivity. Removal of apoptotic hybridoma cells by macrophages at the time of seeding resulted in 100% improved antibody productivity that was, surprisingly to us, most pronounced late on in the cultures. Furthermore, we were able to recapitulate this effect using novel super-paramagnetic Dead-Cert Nanoparticles to remove non-viable cells simply and effectively at culture seeding. These results (1) provide direct evidence that apoptotic cells have a profound influence on their non-phagocytic neighbors in culture and (2) demonstrate the effectiveness of a simple dead-cell removal strategy for improving antibody manufacture in vitro.
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31
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Identification of ARIA regulating endothelial apoptosis and angiogenesis by modulating proteasomal degradation of cIAP-1 and cIAP-2. Proc Natl Acad Sci U S A 2009; 106:8227-32. [PMID: 19416853 DOI: 10.1073/pnas.0806780106] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Endothelial apoptosis is a pivotal process for angiogenesis during embryogenesis as well as postnatal life. By using a retrovirus-mediated signal sequence trap method, we identified a previously undescribed gene, termed ARIA (apoptosis regulator through modulating IAP expression), which regulates endothelial apoptosis and angiogenesis. ARIA was expressed in blood vessels during mouse embryogenesis, as well as in endothelial cells both in vitro and in vivo. ARIA is a unique protein with no homology to previously reported conserved domain structures. Knockdown of ARIA in HUVECs by using small interfering RNA significantly reduced endothelial apoptosis without affecting either cell migration or proliferation. ARIA knockdown significantly increased inhibitor of apoptosis (cIAP)-1 and cIAP-2 protein expression, although their mRNA expression was not changed. Simultaneous knockdown of cIAP-1 and cIAP-2 abolished the antiapoptotic effect of ARIA knockdown. Using yeast 2-hybrid screening, we identified the interaction of ARIA with 20S proteasome subunit alpha-7. Thereafter, we found that cIAP-1 and cIAP-2 were degraded by proteasomes in endothelial cells under normal condition. Overexpression of ARIA significantly reduced cIAP-1 expression, and this reduction was abolished by proteasomal inhibition in BAECs. Also, knockdown of ARIA demonstrated an effect similar to proteasomal inhibition with respect to not only expression but also subcellular localization of cIAP-1 and cIAP-2. In vivo angiogenesis studied by Matrigel-plug assay, mouse ischemic retinopathy model, and tumor xenograft model was significantly enhanced by ARIA knockdown. Together, our data indicate that ARIA is a unique factor regulating endothelial apoptosis, as well as angiogenesis, presumably through modulating proteasomal degradation of cIAP-1 and cIAP-2 in endothelial cells.
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32
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Ohnishi S, Nagaya N. Tissue regeneration as next-generation therapy for COPD--potential applications. Int J Chron Obstruct Pulmon Dis 2009; 3:509-14. [PMID: 19281069 PMCID: PMC2650613 DOI: 10.2147/copd.s1092] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
COPD is a major cause of chronic morbidity and mortality worldwide, and there is a need to develop more effective therapeutic strategies to replace specialized treatment such as lung transplantation. Recent studies suggest that recognition of apoptotic lung epithelial or endothelial cells may result in growth factors to stimulate cell replacement, and defects in these processes may contribute to the pathogenesis of COPD. Furthermore, recent animal and human studies have revealed that tissue-specific stem cells and bone marrow-derived cells contribute to lung tissue regeneration and protection, and thus administration of exogenous stem/progenitor cells or humoral factors responsible for activation of endogenous stem/progenitor cells may be a potent next-generation therapy for COPD.
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Affiliation(s)
- Shunsuke Ohnishi
- Department of Regenerative Medicine and Tissue Engineering, National Cardiovascular Center Research Institute, Suita, Osaka, Japan.
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33
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Yun JH, Henson PM, Tuder RM. Phagocytic clearance of apoptotic cells: role in lung disease. Expert Rev Respir Med 2008; 2:753-65. [PMID: 20477237 PMCID: PMC3956128 DOI: 10.1586/17476348.2.6.753] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Apoptosis and apoptotic clearance are matched processes that are centered in the maintenance of homeostasis. Similar to apoptosis, apoptotic cell clearance is a conserved mechanism that is highly efficient and redundant, highlighting its overall functional importance in homeostasis. Increasing evidence suggests that the mismatch between apoptosis and apoptotic cell clearance underlies pathologic conditions including inflammatory lung diseases, such as chronic obstructive pulmonary disease, cystic fibrosis, asthma, acute lung injury/acute respiratory distress syndrome and cancer immunity. Although direct causality has yet to be established, this paradigm opens novel approaches towards the understanding and treatment of lung diseases. Glucocorticoids, statins and macrolide antibiotics, which are already in use for treating lung conditions, have a positive effect on apoptotic clearance and are among novel agents that are potential candidates for treatment of these disorders.
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Affiliation(s)
- Jeong H Yun
- Program in Translational Lung Research, Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado at Denver, School of Medicine, 12700 East 19th Avenue, Aurora, CO 80045, USA, Tel.: +1 303 724 6049,
| | - Peter M Henson
- Department of Pediatrics, National Jewish Medical and Research Center, Denver, CO, USA, Tel.: +1 303 398 1380, Fax: +1 303 398 1381,
| | - Rubin M Tuder
- Program in Translational Lung Research, Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine, University of Colorado at Denver, School of Medicine, 12700 East 19th Avenue, Aurora, CO 80045, USA, Tel.: +1 303 724 6062,
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34
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Lampkins AJ, O'Neil EJ, Smith BD. Bio-orthogonal phosphatidylserine conjugates for delivery and imaging applications. J Org Chem 2008; 73:6053-8. [PMID: 18616222 DOI: 10.1021/jo8011336] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The syntheses of phosphatidylserine (PS) conjugates are described, including fluorescent derivatives for potential cellular delivery and bioimaging applications. Installation of terminal functional groups (amine, thiol, or alkyne) onto the sn-2 chain provides reactive sites for bio-orthogonal conjugation of cargo with suitably protected PS derivatives. An amine-containing PS forms amide bonds with peptidic cargo, a thiol derivative is designed for conjugation to cargo that contain alpha-halo carbonyls or Michael acceptors, and the terminal alkyne PS analogue permits "click" conjugation with any azide-tagged molecule. This latter conjugation method is quite versatile as it can be performed without PS headgroup protection, in aqueous media, and with acid-labile cargo.
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Affiliation(s)
- Andrew J Lampkins
- Department of Chemistry and Biochemistry and Walther Cancer Research Center, 251 Nieuwland Science Hall, University of Notre Dame, Notre Dame, Indiana 46556, USA
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35
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Myrsky E, Kaukinen K, Syrjänen M, Korponay-Szabó IR, Mäki M, Lindfors K. Coeliac disease-specific autoantibodies targeted against transglutaminase 2 disturb angiogenesis. Clin Exp Immunol 2008; 152:111-9. [PMID: 18279443 DOI: 10.1111/j.1365-2249.2008.03600.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Coeliac disease is characterized by immunoglobulin-A (IgA)-class autoantibodies targeted against transglutaminase 2 (TG2), a multi-functional protein also with a role in angiogenesis. These antibodies are present in patient serum but are also found bound to TG2 below the epithelial basement membrane and around capillaries in the small intestinal mucosa. Based on these facts and the information that the mucosal vasculature of coeliac patients on a gluten-containing diet is disorganized, we studied whether the coeliac disease-specific autoantibodies targeted against TG2 would disturb angiogenesis. The effects of coeliac disease-specific autoantibodies on in vitro angiogenesis were studied in angiogenic cell cultures. The binding of the antibodies to cells, endothelial sprouting, migration of both endothelial and vascular mesenchymal cells, the integrity of the actin cytoskeleton in both cell types and the differentiation of vascular mesenchymal cells were recorded. In vitro, IgA derived from coeliac disease patients on a gluten-containing diet binds to surface TG2 on endothelial and vascular mesenchymal cells and this binding can be inhibited by the removal of TG2. In addition, coeliac disease-specific autoantibodies targeting TG2 disturb several steps of angiogenesis: endothelial sprouting and the migration of both endothelial and vascular mesenchymal cells. Furthermore, the autoantibodies cause disorganization of the actin cytoskeleton in both capillary cell types that account most probably for the defective cellular migration. We conclude that coeliac disease-specific autoantibodies recognizing TG2 inhibit angiogenesis in vitro. This disturbance of the angiogenic process could lead in vivo to the disruption of the mucosal vasculature seen in coeliac disease patients on a gluten-containing diet.
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Affiliation(s)
- E Myrsky
- Paediatric Research Centre, Medical School, University of Tampere, Tampere, Finland
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Affara M, Dunmore B, Savoie C, Imoto S, Tamada Y, Araki H, Charnock-Jones DS, Miyano S, Print C. Understanding endothelial cell apoptosis: what can the transcriptome, glycome and proteome reveal? Philos Trans R Soc Lond B Biol Sci 2007; 362:1469-87. [PMID: 17569639 PMCID: PMC2440409 DOI: 10.1098/rstb.2007.2129] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Endothelial cell (EC) apoptosis may play an important role in blood vessel development, homeostasis and remodelling. In support of this concept, EC apoptosis has been detected within remodelling vessels in vivo, and inactivation of EC apoptosis regulators has caused dramatic vascular phenotypes. EC apoptosis has also been associated with cardiovascular pathologies. Therefore, understanding the regulation of EC apoptosis, with the goal of intervening in this process, has become a current research focus. The protein-based signalling and cleavage cascades that regulate EC apoptosis are well known. However, the possibility that programmed transcriptome and glycome changes contribute to EC apoptosis has only recently been explored. Traditional bioinformatic techniques have allowed simultaneous study of thousands of molecular signals during the process of EC apoptosis. However, to progress further, we now need to understand the complex cause and effect relationships among these signals. In this article, we will first review current knowledge about the function and regulation of EC apoptosis including the roles of the proteome transcriptome and glycome. Then, we assess the potential for further bioinformatic analysis to advance our understanding of EC apoptosis, including the limitations of current technologies and the potential of emerging technologies such as gene regulatory networks.
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Affiliation(s)
- Muna Affara
- Department of Pathology, Cambridge UniversityTennis Court Road, Cambridge CB2 1QP, UK
| | - Benjamin Dunmore
- Department of Obstetrics and Gynaecology, Cambridge UniversityThe Rosie Hospital, Cambridge CB2 2SW, UK
| | - Christopher Savoie
- GNI Ltd. Kasumigaseki IHF Building 3-5-1Kasumigaseki, Chiyoda-ku, 100-0013 Toyko, Japan
| | - Seiya Imoto
- Human Genome Centre, Institute of Medical Science, University of Tokyo4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Yoshinori Tamada
- Department of Obstetrics and Gynaecology, Cambridge UniversityThe Rosie Hospital, Cambridge CB2 2SW, UK
- Bioinformatics Centre, Institute for Chemical Research, Kyoto UniversityGokasho, Uji, Kyoto 611-0011, Japan
| | - Hiromitsu Araki
- GNI Ltd. Kasumigaseki IHF Building 3-5-1Kasumigaseki, Chiyoda-ku, 100-0013 Toyko, Japan
| | - D. Stephen Charnock-Jones
- Department of Obstetrics and Gynaecology, Cambridge UniversityThe Rosie Hospital, Cambridge CB2 2SW, UK
| | - Satoru Miyano
- Human Genome Centre, Institute of Medical Science, University of Tokyo4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Cristin Print
- Department of Molecular Medicine and Pathology, University of Auckland85 Park Road, Private Bag 92019, Auckland, New Zealand
- Author for correspondence ()
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Erwig LP, Henson PM. Immunological consequences of apoptotic cell phagocytosis. THE AMERICAN JOURNAL OF PATHOLOGY 2007; 171:2-8. [PMID: 17591947 PMCID: PMC1941587 DOI: 10.2353/ajpath.2007.070135] [Citation(s) in RCA: 170] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/17/2007] [Indexed: 01/14/2023]
Abstract
Cells undergo apoptosis in development, tissue homeostasis, and disease and are subsequently cleared by professional and nonprofessional phagocytes. There is now overwhelming evidence that phagocyte function is profoundly altered following apoptotic cell uptake, with consequences for the ensuing innate and adaptive immune response. Pathogens and tumors exploit the changes in macrophage function following apoptotic cell uptake. Here, we will outline the consequences of apoptotic cell phagocytosis and illustrate how apoptotic cells could be used to manipulate the immune response for therapeutic gain.
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Affiliation(s)
- Lars-Peter Erwig
- Department of Medicine and Therapeutics, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, UK.
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38
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Abstract
Phagocytic clearance of apoptotic cells may be considered to consist of four distinct steps: accumulation of phagocytes at the site where apoptotic cells are located; recognition of dying cells through a number of bridge molecules and receptors; engulfment by a unique uptake process; and processing of engulfed cells within phagocytes. Here, we will discuss these individual steps that collectively are essential for the effective removal of apoptotic cells. This will illustrate our relative lack of knowledge about the initial attraction signals, the specific mechanisms of engulfment and processing in comparison to the extensive literature on recognition mechanisms. There is now mounting evidence that clearance defects are responsible for chronic inflammatory disease and contribute to autoimmunity. Therefore, a better understanding of all aspects of the clearance process is required before it can truly be manipulated for therapeutic gain.
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Affiliation(s)
- L-P Erwig
- Department of Medicine and Therapeutics, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, UK.
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Gao J, Liang G, Zhang B, Kuang Y, Zhang X, Xu B. FePt@CoS(2) yolk-shell nanocrystals as a potent agent to kill HeLa cells. J Am Chem Soc 2007; 129:1428-33. [PMID: 17263428 DOI: 10.1021/ja067785e] [Citation(s) in RCA: 258] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report the evaluation of cytotoxicity of a new type of engineered nanomaterials, FePt@CoS(2) yolk-shell nanocrystals, synthesized by the mechanism of the Kirkendall effect when FePt nanoparticles serve as the seeds. The cytotoxicity of FePt@CoS(2) yolk-shell nanocrystals, evaluated by MTT assay, shows a much lower IC(50) (35.5 +/- 4.7 ng of Pt/mL for HeLa cell) than that of cisplatin (230 ng of Pt/mL). In the control experiment, cysteine-modified FePt nanoparticles exhibit IC50 at 12.0 +/- 0.9 microg of Pt/mL. Transmission electron microscopy confirms the cellular uptake of FePt@CoS(2) nanocrystals, and the magnetic properties analysis (SQUID) proves the release of FePt nanoparticles from the yolk-shell nanostructures after cellular uptake. These results are significant because almost none of the platinum-based complexes produced for clinical trials in the past 3 decades have shown higher activity than that of the parent drug, cisplatin. The exceptionally high toxicity of FePt@CoS(2) yolk-shell nanocrystals (about 7 times higher than that of cisplatin in terms of Pt) may lead to a new design of an anticancer nanomedicine.
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Affiliation(s)
- Jinhao Gao
- Department of Chemistry, Center for Cancer Research, Department of Physics, and Bioengineering Program, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
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Henson PM, Vandivier RW, Douglas IS. Cell death, remodeling, and repair in chronic obstructive pulmonary disease? Ann Am Thorac Soc 2007; 3:713-7. [PMID: 17065379 PMCID: PMC2647658 DOI: 10.1513/pats.200605-104sf] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Apoptotic cells can be detected in the parenchyma and airways of patients with chronic obstructive pulmonary disease (COPD) in greater numbers than seen in normal lungs or those from smokers without COPD. Implications include more apoptosis and/or decreased clearance of apoptotic cells. Both epithelial and endothelial cells become apoptotic. What role does the apoptosis play in the emphysema or small airway alterations seen in COPD? In simple terms, loss of cells by apoptosis would be expected to accompany, or perhaps initiate, the overall tissue destruction normally believed responsible. Indeed, direct induction of apoptosis in pulmonary endothelial or epithelial cells in rodents is accompanied by emphysematous changes. On the other hand, apoptotic cells are normally removed from tissues rapidly with minimal tissue response, to be followed by cell replacement to maintain homeostasis. The presence of detectable apoptotic cells, therefore, may imply defects in these clearance mechanisms, and, in keeping with this hypothesis, there is increasing evidence for such defects in patients with COPD. Mice with abnormalities in apoptotic cell removal also tend to develop spontaneous "emphysema." A reconciling hypothesis is that recognition of apoptotic cells not only leads to removal but also, normally, to signals for cell replacement. If this latter response is lacking in COPD-susceptible smokers, defects in normal alveolar or small airway repair could significantly contribute to the structural disruption. The concept puts emphasis on defective repair as well as initial injury (i.e., persistent alteration of dynamic tissue homeostasis, as a key contributor to COPD), with, it is hoped, additional approaches for mitigation.
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Affiliation(s)
- Peter M Henson
- National Jewish Medical and Research Center, 1400 Jackson Street, Denver, CO 80206, USA.
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Duval H, Johnson N, Li J, Evans A, Chen S, Licence D, Skepper J, Charnock-Jones DS, Smith S, Print C. Vascular development is disrupted by endothelial cell-specific expression of the anti-apoptotic protein Bcl-2. Angiogenesis 2006; 10:55-68. [PMID: 17149535 DOI: 10.1007/s10456-006-9057-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2006] [Accepted: 10/22/2006] [Indexed: 12/01/2022]
Abstract
Endothelial cell (EC) apoptosis has been detected in remodelling blood vessels in vivo, and inhibition of EC apoptosis appears to alter vascular morphogenesis in vitro, suggesting that EC apoptosis may play a role in blood vessel remodelling. However, apoptotic EC are difficult to quantify in vivo, and studies of the incidence of EC apoptosis and the sites at which it occurs in vivo have produced contradictory results. Therefore, the specific biological roles played by EC apoptosis remain unclear. Here, we have used a transgenic approach to determine the biological function of EC apoptosis in vivo. Anti-apoptotic Bcl-2 transgenes were expressed in mice under control of the EC-specific tie2 promoter. These transgenic mice died during the second half of gestation. While the development and remodelling of large vessels including aortic arch arteries and great veins proceeded normally, abnormally dense and disorganised networks of small vessels were present in the skin and internal organs. In addition, vessel organisation and lumen formation were disrupted in the placental labyrinth. This study provides direct experimental evidence that endothelial cell apoptosis plays an essential role during embryogenesis. Our results suggest that EC apoptosis plays an important role in determining the structure of the microcirculation but may be dispensable for large vessel development.
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Affiliation(s)
- Hélène Duval
- Department of Pathology, Cambridge University, Tennis Court Road, Cambridge CB2 1QP, UK
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Schwab A, Nechyporuk-Zloy V, Fabian A, Stock C. Cells move when ions and water flow. Pflugers Arch 2006; 453:421-32. [PMID: 17021798 DOI: 10.1007/s00424-006-0138-6] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2006] [Accepted: 07/09/2006] [Indexed: 12/22/2022]
Abstract
Cell migration is a process that plays an important role throughout the entire life span. It starts early on during embryogenesis and contributes to shaping our body. Migrating cells are involved in maintaining the integrity of our body, for instance, by defending it against invading pathogens. On the other side, migration of tumor cells may have lethal consequences when tumors spread metastatically. Thus, there is a strong interest in unraveling the cellular mechanisms underlying cell migration. The purpose of this review is to illustrate the functional importance of ion and water channels as part of the cellular migration machinery. Ion and water flow is required for optimal migration, and the inhibition or genetic ablation of channels leads to a marked impairment of migration. We briefly touch cytoskeletal mechanisms of migration as well as cell-matrix interactions. We then present some general principles by which channels can affect cell migration before we discuss each channel group separately.
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Affiliation(s)
- Albrecht Schwab
- Institut für Physiologie II, Universität Münster, Robert-Koch-Str. 27b, 48149, Münster, Germany.
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Liang G, Wang L, Yang Z, Koon H, Mak N, Chang CK, Xu B. Using enzymatic reactions to enhance the photodynamic therapy effect of porphyrin dityrosine phosphates. Chem Commun (Camb) 2006:5021-3. [PMID: 17146514 DOI: 10.1039/b611557h] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This paper reports the synthesis and photodynamic therapy (PDT) effect of a porphyrin derivative containing tyrosine phosphate, which promises a new, useful approach to develop PDT agents.
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Affiliation(s)
- Gaolin Liang
- Department of Chemistry, The Hong Kong University of Science & Technology, Clear Water Bay, Hong Kong, China
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