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Abstract
Methods for assessing mammalian cell death are presented in this article, which is divided into six sections: (1) a brief overview of cytotoxicity and pathways of cell death; (2) a method to measure cell death using lactate dehydrogenase (LDH) release as a marker of membrane integrity; (3) a flow cytometry method that simultaneously measures two types of cell death, necrosis and apoptosis; (4) use of fluorescence microscopy and nuclear morphology to assess apoptosis and necrosis; (5) the use of multi-well plates and high-content analysis imaging systems to assess nuclear morphology; and (6) a discussion of the use of cytotoxicity assays to determine the mechanisms of cell death. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Measurement of plasma membrane integrity and viability using LDH release Basic Protocol 2: Measurement of necrosis and apoptosis using flow cytometry Basic Protocol 3: Determination of nuclear morphology and membrane integrity Alternate Protocol 1: Assessment of nuclear morphology and membrane integrity using DAPI and PI Alternate Protocol 2: Assessment of nuclear morphology using multi-well plates Basic Protocol 4: Measurement of time-dependent toxicity using cell death markers.
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Affiliation(s)
- Brian S Cummings
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia, Athens, Georgia.,Interdisciplinary Toxicology Program, University of Georgia, Athens, Georgia
| | - Rick G Schnellmann
- Pharmacology and Toxicology, University of Arizona, Tucson, Arizona.,Southern Arizona VA Healthcare System, Tucson, Arizona
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2
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Futakuchi A, Inoue T, Wei FY, Inoue-Mochita M, Fujimoto T, Tomizawa K, Tanihara H. YAP/TAZ Are Essential for TGF-β2–Mediated Conjunctival Fibrosis. ACTA ACUST UNITED AC 2018; 59:3069-3078. [DOI: 10.1167/iovs.18-24258] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Akiko Futakuchi
- Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Toshihiro Inoue
- Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Fan-Yan Wei
- Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Miyuki Inoue-Mochita
- Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Tomokazu Fujimoto
- Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Kazuhito Tomizawa
- Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Hidenobu Tanihara
- Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
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Aebisher D, Bartusik D, Tabarkiewicz J. Laser flow cytometry as a tool for the advancement of clinical medicine. Biomed Pharmacother 2017; 85:434-443. [DOI: 10.1016/j.biopha.2016.11.048] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Revised: 11/08/2016] [Accepted: 11/08/2016] [Indexed: 12/11/2022] Open
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Futakuchi A, Inoue T, Fujimoto T, Inoue-Mochita M, Kawai M, Tanihara H. The effects of ripasudil (K-115), a Rho kinase inhibitor, on activation of human conjunctival fibroblasts. Exp Eye Res 2016; 149:107-115. [PMID: 27394186 DOI: 10.1016/j.exer.2016.07.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 06/17/2016] [Accepted: 07/05/2016] [Indexed: 02/06/2023]
Abstract
The most common cause of glaucoma surgery failure is scar formation induced by activation of wound-healing responses and resultant fibrosis at the surgical site. We investigated the effects of ripasudil, a Rho kinase inhibitor, on activation of human conjunctival fibroblasts (HConF). HConF were pretreated with different concentrations of ripasudil for 1 h before addition of transforming growth factor (TGF)-β2, followed by incubation for 48 h. TGF-β2-treated fibroblasts exhibited a significant increase in expression of α-smooth muscle actin (α-SMA), a marker of fibroblast-to-myofibroblast differentiation, and this increase was significantly suppressed, in a dose-dependent manner, by pretreatment with ripasudil. Ripasudil pretreatment also significantly attenuated TGF-β2-induced fibronectin production and collagen gel contraction. TGF-β2 increased both the number of viable cells and the number of cells in the G2/M phase of the cell cycle; these effects were attenuated by pretreatment with ripasudil. In addition, we explored the effects of ripasudil on stimulation of HConF by activated macrophages. Human monocytic cell line THP-1 cells were differentiated into M1 or M2 macrophage-like cells, and HConF were treated with conditioned media derived from these macrophages in the presence or absence of ripasudil. Conditioned medium from M2 macrophage-like cells induced a significant increase in α-SMA expression, viable cell numbers, and gel contraction, all of which were significantly suppressed by ripasudil. Thus, overall, ripasudil attenuated activation of human conjunctival fibroblasts. Ripasudil may be of therapeutic utility, preventing excessive scarring after glaucoma filtration surgery.
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Affiliation(s)
- Akiko Futakuchi
- Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Toshihiro Inoue
- Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan.
| | - Tomokazu Fujimoto
- Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Miyuki Inoue-Mochita
- Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Motofumi Kawai
- Department of Ophthalmology, Asahikawa Medical University, Asahikawa, Japan
| | - Hidenobu Tanihara
- Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
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Rana C, Vaish V, Piplani H, Nehru B, Sanyal SN. Nuclear Factor-κB is expressed in early colon cancer and its down-regulation by Curcumin and Diclofenac is associated with the suppression of proliferation and the induction of apoptosis. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.bionut.2012.07.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Abstract
Formation of new vessels during development and in the mature mammal generally proceeds through angiogenesis. Although a variety of molecules and signaling pathways are known to underlie endothelial cell sprouting and remodeling during angiogenesis, many aspects of this complex process remain unexplained. Here we show that the transmembrane semaphorin6A (Sema6A) is expressed in endothelial cells, and regulates endothelial cell survival and growth by modulating the expression and signaling of VEGFR2, which is known to maintain endothelial cell viability by autocrine VEGFR signaling. The silencing of Sema6A in primary endothelial cells promotes cell death that is not rescued by exogenous VEGF-A or FGF2, attributable to the loss of prosurvival signaling from endogenous VEGF. Analyses of mouse tissues demonstrate that Sema6A is expressed in angiogenic and remodeling vessels. Mice with null mutations of Sema6A exhibit significant defects in hyaloid vessels complexity associated with increased endothelial cell death, and in retinal vessels development that is abnormally reduced. Adult Sema6A-null mice exhibit reduced tumor, matrigel, and choroidal angiogenesis compared with controls. Sema6A plays important roles in development of the nervous system. Here we show that it also regulates vascular development and adult angiogenesis.
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Cummings BS, Schnellmann RG. Measurement of cell death in mammalian cells. ACTA ACUST UNITED AC 2012; Chapter 12:Unit 12.8. [PMID: 22294120 DOI: 10.1002/0471141755.ph1208s25] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This unit presents methods used to assess cell death in mammalian cells. The unit is divided into five sections: (1) a brief overview of cytotoxicity and pathways of cell death, (2) an improved method to measure cell death using lactate dehydrogenase (LDH) release as a marker of membrane integrity, (3) a flow cytometry method that simultaneously measures two types of cell death, oncosis and apoptosis, (4) use of nuclear morphology to assess apoptosis and oncosis, and (5) a brief discussion of the use of cytotoxicity assays to determine the mechanisms of cell death.
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Affiliation(s)
- Brian S Cummings
- Medical University of South Carolina, Charleston, South Carolina, USA
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Cummings BS, Wills LP, Schnellmann RG. Measurement of Cell Death in Mammalian Cells. ACTA ACUST UNITED AC 2012; Chapter 12:Unit12.8. [DOI: 10.1002/0471141755.ph1208s56] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Brian S. Cummings
- Department of Pharmaceutical and Biomedical Sciences, University of Georgia; Athens Georgia
| | - Lauren P. Wills
- Department of Pharmaceutical and Biomedical Sciences, Medical University of South Carolina; Charleston South Carolina
| | - Rick G. Schnellmann
- Department of Pharmaceutical and Biomedical Sciences, Medical University of South Carolina; Charleston South Carolina
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Cytoprotective effect of lithium against spontaneous and induced apoptosis of lymphoid cell line MOLT-4. Folia Histochem Cytobiol 2009; 47:639-46. [PMID: 20430733 DOI: 10.2478/v10042-009-0118-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Lithium (Li) is still useful in the treatment of bipolar disorder. Cellular mechanisms of Li action are not fully understood and include some cytoprotective properties. Data concerning Li effect on the apoptotic mechanisms in cells other than neurons are fragmentary and contradictory. We have investigated anti-apoptotic activity of Li in a lymphoid derived MOLT-4 cell line. Spontaneous and camptothecin-induced apoptosis was analyzed in cells treated with 0-20 mM Li carbonate. Early apoptosis was identified as significant mitochondrial depolarization (JC-1 staining). Later stages of apoptosis were estimated with annexin V binding and by the proportion of cells containing sub-G1 amounts of DNA (PI staining). We have observed a biphasic effect of Li on the proportion of spontaneously apoptotic cells;namely, low (therapeutic) concentrations of Li had a significant effect stabilizing the mitochondrial membrane polarization, while 10 and 20mM Li increased apoptosis. The latter could be seen both as mitochondrial depolarization as well as an increased proportion of sub-G1 cells, accompanied by reduced proportion of S phase cells. Li at concentrations above 2 mM had a significant, dose-dependent, anti-apoptotic effect on the cells undergoing camptothecin induced apoptosis. In conclusion, demonstrated cytoprotective effect of Li is at least partially related to stabilization of mitochondrial membrane potential and to the reduction of DNA damaging effects in proliferating cells; both may form part of the mechanism through which Li is useful in therapy of bipolar disorder, but may have more general consequences.
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Kamarajan P, Kapila YL. An altered fibronectin matrix induces anoikis of human squamous cell carcinoma cells by suppressing integrin alpha v levels and phosphorylation of FAK and ERK. Apoptosis 2008; 12:2221-31. [PMID: 17879163 DOI: 10.1007/s10495-007-0138-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Fibronectin regulates many cellular processes, including migration, proliferation, differentiation, and survival. Previously, we showed that squamous cell carcinoma (SCC) cell aggregates escape suspension-induced, p53-mediated anoikis by engaging in fibronectin-mediated survival signals through focal adhesion kinase (FAK). Here we report that an altered matrix, consisting of a mutated, nonfunctional high-affinity heparin-binding domain and the V region of fibronectin (V+H-), induced anoikis in human SCC cells; this response was blocked by inhibitors of caspase-8 and caspase-3. Anoikis was mediated by downregulation of integrin alpha v in a panel of SCC cells and was shown to be proteasome-dependent. Overexpression of integrin alpha v or FAK inhibited the increase in caspase-3 activation and apoptosis, whereas suppression of alpha v or FAK triggered a further significant increase in apoptosis, indicating that the apoptosis was mediated by suppression of integrin alpha v levels and dephosphorylation of FAK. Treatment with V+H- decreased the phosphorylation of extracellular signal-regulated kinase (ERK) 1 and 2, and direct activation of ERK by constitutively active MEK1, an ERK kinase, increased ERK1 and ERK2 phosphorylation and inhibited the increase in apoptosis induced by V+H-. ERK acted downstream from alpha v and FAK signals, since alpha v and FAK overexpression inhibited both the decrease in ERK phosphorylation and the increase in anoikis triggered by V+H-. These findings provide evidence that mutations in the high-affinity heparin-binding domain in association with the V region of fibronectin, or altered fibronectin matrices, induce anoikis in human SCC cells by modulating integrin alpha v-mediated phosphorylation of FAK and ERK.
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Affiliation(s)
- Pachiyappan Kamarajan
- Department of Periodontics and Oral Medicine, University of Michigan, School of Dentistry, 1011 N. University Ave, Room 5223, Ann Arbor, MI 48109-1078, USA
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Gardell JL, Dazin P, Islar J, Menge T, Genain CP, Lalive PH. Apoptotic effects of Human Herpesvirus-6A on glia and neurons as potential triggers for central nervous system autoimmunity. J Clin Virol 2007; 37 Suppl 1:S11-6. [PMID: 17276360 DOI: 10.1016/s1386-6532(06)70005-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Human Herpesvirus type 6 (HHV-6A and/or HHV-6B) has been tentatively associated with multiple sclerosis (MS). However, there is currently no direct proof of pathogenicity. OBJECTIVES To determine whether exposure to HHV-6 variants is capable of inducing programmed cell death (apoptosis) in representative cell types of the central nervous system (CNS). STUDY DESIGN HHV-6A and HHV-6B variants were grown on human T cell lines HSB2 and MOLT-3, respectively. Human neuronal (SK-N-SH), astrocytes (CRT), and oligodendrocytes (TC620) cell lines were exposed in vitro to infected T cells in a trans-well system for up to 4 days (5x10(4) cells target cells and 2x10(6) T cells). Apoptosis was measured by a FACS-based method. RESULTS Exposure to HHV-6A induced apoptosis in a time-dependent manner, while exposure to HHV-6B did not. Three days after exposure, apoptosis was increased compared to normalized controls, by 239% in neurons, 321% in astrocytes, and 326% in oligodendrocytes, respectively. CONCLUSIONS This study provides the demonstration that exposure to immune cells carrying replicating HHV-6A may injure glial cells and neurons by inducing apoptosis, and direct evidence for a causal association between HHV-6A with MS and related disorders.
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Affiliation(s)
- Jennifer L Gardell
- Department of Neurology, University of California, San Francisco, CA, USA
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Abstract
Fluorosed enamel is caused by exposure to fluoride during tooth formation. The objective of this study was to determine whether epithelial ameloblast-lineage cells, derived from the human enamel organ, are directly affected by micromolar concentrations of fluoride. Cells were cultured in the presence of fluoride, and proliferation was measured by BrdU incorporation. The effect of 0, 10, or 20 microM fluoride on apoptosis was determined by the flow cytometry apoptotic index. The effects of fluoride on gene expression were investigated by SuperArray microarray analysis and real-time PCR. Fluoride had a biphasic effect on cell proliferation, with enhanced proliferation at 16 microM, and reduced proliferation at greater than 1 mM F. Flow cytometry showed that both 10 microM and 20 microM NaF significantly increased the apoptotic index of ameloblast-lineage cells. There was no general effect of fluoride on gene expression. These results indicate multiple effects of micromolar fluoride on ameloblast-lineage cells.
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Affiliation(s)
- Q Yan
- Department of Orofacial Sciences, University of California at San Francisco, 513 Parnassus Ave. S-704, San Francisco, CA 94143-0422, USA
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Hillion JA, Li Y, Maric D, Takanohashi A, Klimanis D, Barker JL, Hallenbeck JM. Involvement of Akt in preconditioning-induced tolerance to ischemia in PC12 cells. J Cereb Blood Flow Metab 2006; 26:1323-31. [PMID: 16511503 PMCID: PMC1855183 DOI: 10.1038/sj.jcbfm.9600286] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The serine-threonine protein kinase Akt has been identified as an important mediator of cell survival able to counteract apoptotic stimuli. However, hibernation, a model of natural tolerance to cerebral ischemia, is associated with downregulation of Akt. We previously established a model of ischemic tolerance in a PC12 cell line and using this model we now addressed the question whether ischemic tolerance also downregulates Akt in PC12 cells. Kinetic studies showed decreased Akt phosphorylation in tolerized cells. Similarly, phosphorylated levels of three major targets of Akt and well-known proapoptotic factors, the glycogen synthase kinase 3 (GSK-3), a Forkhead family member, FoxO4, and the protein murine double minute 2 (MDM2), all inactivated upon phosphorylation by Akt, were decreased in preconditioned cells. In addition, pharmacological blockade of the phosphoinositide 3-kinase (PI3K)/Akt pathway reduced cell death induced by oxygen and glucose deprivation (OGD) and increased the protective effect of preconditioning (PC). Furthermore, decreasing availability of P-Akt by transfecting PC12 cells with constructs of inactive Akt also resulted in protection against OGD and potentiation of the protective effect of PC. Depending on the environment, GSK-3, FOXO-4, and MDM2 can trigger apoptotic responses or cell cycle arrest, and thus, in a situation of reduced energy, driving the cells into a state of quiescence might be neuroprotective. This work suggests that in the context of tolerance downregulation of Akt is beneficial.
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Affiliation(s)
- Joëlle A Hillion
- 1Stroke Branch, Department of Health and Human Services, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892-4476, USA.
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Chowdhury I, Tharakan B, Bhat GK. Current concepts in apoptosis: the physiological suicide program revisited. Cell Mol Biol Lett 2006; 11:506-25. [PMID: 16977376 PMCID: PMC6275981 DOI: 10.2478/s11658-006-0041-3] [Citation(s) in RCA: 158] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2006] [Accepted: 06/22/2006] [Indexed: 12/15/2022] Open
Abstract
Apoptosis, or programmed cell death (PCD), involves a complex network of biochemical pathways that normally ensure a homeostatic balance between cellular proliferation and turnover in nearly all tissues. Apoptosis is essential for the body, as its deregulation can lead to several diseases. It plays a major role in a variety of physiological events, including embryonic development, tissue renewal, hormone-induced tissue atrophy, removal of inflammatory cells, and the evolution of granulation tissue into scar tissue. It also has an essential role in wound repair. The various cellular and biochemical mechanisms involved in apoptosis are not fully understood. However, there are two major pathways, the extrinsic pathway (receptor-mediated apoptotic pathway) and the intrinsic pathway (mitochondria-mediated apoptotic pathway), which are both well established. The key component in both is the activation of the caspase cascade. Caspases belong to the family of proteases that ultimately, by cleaving a set of proteins, cause disassembly of the cell. Although the caspase-mediated proteolytic cascade represents a central point in the apoptotic response, its initiation is tightly regulated by a variety of other factors. Among them, Bcl-2 family proteins, TNF and p53 play pivotal roles in the regulation of caspase activation and in the regulation of apoptosis. This review summarizes the established concepts in apoptosis as a physiological cell suicide program, highlighting the recent and significant advances in its study.
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Affiliation(s)
- Indrajit Chowdhury
- Department of Obstetrics and Gynecology, Morehouse School of Medicine, Atlanta, GA USA
| | - Binu Tharakan
- Department of Neurology, Scott and White Clinic, The Texas A & M University Health Science Center, College of Medicine, Temple, Texas USA
| | - Ganapathy K. Bhat
- Department of Obstetrics and Gynecology, Morehouse School of Medicine, Atlanta, GA USA
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Wu LY, Ding AS, Zhao T, Ma ZM, Wang FZ, Fan M. Underlying mechanism of hypoxic preconditioning decreasing apoptosis induced by anoxia in cultured hippocampal neurons. Neurosignals 2005; 14:109-16. [PMID: 16088225 DOI: 10.1159/000086293] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2004] [Accepted: 01/06/2005] [Indexed: 11/19/2022] Open
Abstract
It is known that hypoxic preconditioning (HP, a brief period of sublethal hypoxia) provides neuroprotection against subsequent severe anoxia, but the mechanisms of this increased tolerance have not been fully elucidated. A hypoxic preconditioning model was established by exposing a 4-day hippocampal culture to 1% O(2) for 20 min/day for 8 days. The preconditioning significantly decreased the number of apoptotic neurons at reoxygenation 24 h after 4 h of severe anoxia (0% O(2)). Further study demonstrated that the degradation of mitochondrial membrane potential (MMP) was greatly inhibited and the expression of B-cell lymphoma protein-2 (Bcl-2) was increased considerably after severe anoxia in the HP groups. These results indicate that the increased anoxic tolerance, which is induced by HP in cultured hippocampal cells, may be correlated with Bcl-2 overexpression and enhanced stability of MMP, which ultimately reduces apoptosis 24 h after reoxygenation.
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Affiliation(s)
- Li-ying Wu
- Department of Neurobiology, Institute of Basic Medical Sciences, Beijing, PR China
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Hillion JA, Takahashi K, Maric D, Ruetzler C, Barker JL, Hallenbeck JM. Development of an ischemic tolerance model in a PC12 cell line. J Cereb Blood Flow Metab 2005; 25:154-162. [PMID: 15647748 PMCID: PMC1378216 DOI: 10.1038/sj.jcbfm.9600003] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Although ischemic tolerance has been described in a variety of primary cell culture systems, no similar in vitro models have been reported with any cell line. A model of ischemic preconditioning in the rat pheochromocytoma PC12 cell line is described here. When compared to nonpreconditioned cells, preexposure of PC12 cells to 6 hours of oxygen and glucose deprivation (OGD) significantly increased cell viability after 15 hours of OGD 24 hours later. Flow cytometry analysis of cells labeled with specific markers for apoptosis, Annexin V, and Hoechst 33342, and of DNA content, revealed that apoptosis is involved in OGD-induced PC12 cell death and that preconditioning of the cells mainly counteracts the effect of apoptosis. Immunocytochemistry of caspase-3, a central executioner in the apoptotic process, further confirmed the activation of apoptotic pathways in OGD-induced PC12 cell death. This model may be useful to investigate the cellular mechanisms involved in neuronal transient tolerance following ischemia.
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Affiliation(s)
- Joëlle A Hillion
- Stroke Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Kenzo Takahashi
- Stroke Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Dragan Maric
- Laboratory of Neurophysiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Christl Ruetzler
- Stroke Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Jeffery L Barker
- Laboratory of Neurophysiology, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - John M Hallenbeck
- Stroke Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
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Zhang Y, Lu H, Dazin P, Kapila Y. Squamous cell carcinoma cell aggregates escape suspension-induced, p53-mediated anoikis: fibronectin and integrin alphav mediate survival signals through focal adhesion kinase. J Biol Chem 2004; 279:48342-9. [PMID: 15331608 DOI: 10.1074/jbc.m407953200] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Resistance to anoikis, or apoptosis triggered by detachment from the extracellular matrix (ECM), lengthens the survival of malignant cells, facilitating reattachment and colonization of secondary sites. To examine the molecular mechanisms underlying resistance to anoikis in human oral squamous cell carcinoma (SCC) cells, we cultured human squamous carcinoma (HSC-3) cells in suspension on plates coated with poly-2-hydroxyethyl methacrylate, which blocks access to the ECM. Cells in suspension that formed multicellular aggregates had significantly lower levels of apoptosis than single cells. Aggregates, but not single cells, had high levels of fibronectin. Preincubation with a cyclic arginine-glycine-aspartic acid peptide or fibronectin-blocking antibody significantly increased anoikis. Single cells had markedly lower expression of the integrin alpha(v) receptor than aggregates. Blocking alpha(v) function with a blocking antibody or by transfection with an antisense oligonucleotide increased apoptosis and inhibited aggregation. In single cells but not aggregates, phosphorylation of the integrin-associated focal adhesion kinase (FAK) at tyrosine 397 was reduced, and p53 levels were increased. Apoptosis was increased by blocking FAK with an antisense oligonucleotide and reduced by blocking p53. These findings show that SCC cells escape suspension-induced anoikis by forming multicellular aggregates that avail themselves of fibronectin survival signals mediated by integrin alpha(v). Single cells in suspension that do not form aggregates undergo anoikis because of decreased FAK phosphorylation and increased p53 levels. Thus, SCC cells appear to use neighboring cells and the ECM molecule FN to promote the metastatic phenotype.
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Affiliation(s)
- Yan Zhang
- Department of Stomatology, School of Dentistry, and Howard Hughes Medical Institute, School of Medicine, University of California, San Francisco, California 94143, USA
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Cruz AC, Frank BT, Edwards ST, Dazin PF, Peschon JJ, Fang KC. Tumor necrosis factor-alpha-converting enzyme controls surface expression of c-Kit and survival of embryonic stem cell-derived mast cells. J Biol Chem 2003; 279:5612-20. [PMID: 14625290 DOI: 10.1074/jbc.m312323200] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Transmembrane metalloproteinases of the disintegrin and metalloproteinase (ADAM) family control cell signaling interactions via hydrolysis of protein extracellular domains. Prior work has shown that the receptor tyrosine kinase, c-Kit (CD117), is essential for mast cell survival and that serum levels of c-Kit increase in proliferative mast cell disorders, suggesting the existence of c-Kit shedding pathways in mast cells. In the present work, we report that tumor necrosis factor alpha-converting enzyme (TACE; ADAM-17) mediates shedding of c-Kit. Stimulation of transfected cells with phorbol 12-myristate 13-acetate (PMA) induced metalloproteinase-mediated release of c-Kit ectodomain, which increased further upon TACE overexpression. By contrast, TACE-deficient fibroblasts did not demonstrate inducible release, thus identifying TACE as the metalloproteinase primarily responsible for PMA-induced c-Kit shedding. Surface expression of c-Kit by the human mast cell-1 line decreased upon phorbol-induced shedding, which involved metalloproteinase activity susceptible to inhibition by tissue inhibitor of metalloproteinase (TIMP)-3. To further explore the role of TACE in shedding of c-Kit from mast cells, we compared the behavior of mast cells derived from murine embryonic stem cells. In these studies, PMA decreased surface c-Kit levels on mast cells expressing wild-type (+/+) TACE but not on those expressing an inactive mutant (DeltaZn/DeltaZn), confirming the role of TACE in PMA-induced c-Kit shedding. Compared with TACE(+/+) cells, TACE(DeltaZn/DeltaZn) mast cells also demonstrated decreased constitutive shedding and increased basal surface expression of c-Kit, with diminished apoptosis in response to c-Kit ligand deprivation. These data suggest that TACE controls mast cell survival by regulating shedding and surface expression of c-Kit.
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Affiliation(s)
- Anthony C Cruz
- Cardiovascular Research Institute, University of California, San Francisco, California 94143, USA
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Chastagner P, Reddy J, Thèze J. Lymphoadenopathy in IL-2-deficient mice: further characterization and overexpression of the antiapoptotic molecule cellular FLIP. THE JOURNAL OF IMMUNOLOGY 2002; 169:3644-51. [PMID: 12244156 DOI: 10.4049/jimmunol.169.7.3644] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
IL-2 was originally identified as a potent T cell growth factor. It was subsequently demonstrated that IL-2 also exerts proapoptotic effects under certain conditions. Inactivation of IL-2 by gene targeting in mice showed that whereas IL-2 is not essential for the generation, clonal expansion, or differentiation of lymphocytes to effector cells, it has a unique role in preventing the accumulation of activated lymphocytes. IL-2(-/-) mice show lymphoadenopathy and autoimmune reactions, suggesting that the proapoptotic effects of IL-2 may predominate in vivo. In this study, we confirm that lymph nodes (LNs) are enlarged in IL-2(-/-) animals, but surprisingly, we found that their spleens are almost normal in size. Subsequent to this observation, we compare lymphocytes from LNs and spleens of IL-2(-/-) and IL-2(+/-) animals to analyze molecular and cellular correlates of the immunopathological disorders found in IL-2-deficient mice. LN lymphocytes from IL-2(-/-) are selectively activated and show an enhanced survival capacity and an increased ability to proliferate in vitro when compared with LN cells from IL-2(+/-) mice and splenocytes from IL-2(-/-) and IL-2(+/-) mice. Because the apoptosis inhibitor FLIP has been shown in vitro to participate in the IL-2 control of activation-induced cell death, we analyze its expression in IL-2(-/-) mice. FLIP was found to be selectively overexpressed in the LNs of IL-2(-/-) mice, but no overexpression was found in spleen cells or thymocytes. These results suggest that FLIP, in conjunction with other IL-2-regulated genes previously characterized in our laboratory, is involved in controlling lymphoadenopathy in IL-2(-/-) mice.
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Affiliation(s)
- Patricia Chastagner
- Unité d'Immunogénétique Cellulaire, Département de Médecine Moléculaire, Institut Pasteur, Paris, France
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Elegbede JA, Hayes K, Schell K, Oberley TD, Verma AK. Induction of apoptosis and inhibition of papilloma formation may signal a new role for okadaic acid. Life Sci 2002; 71:421-36. [PMID: 12044842 DOI: 10.1016/s0024-3205(02)01701-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Okadaic acid (OA), a tumor promoter in the mouse skin carcinogenesis model, has been shown to induce apoptosis in tumor cell lines that harbor H-ras mutations. We examined the effects of OA on mouse keratinocytes with (308) and without (C50) H-ras mutation in vitro and in an in vivo system. Following exposure to varying concentrations of OA over time, the effects of OA in vitro were assessed using microscopic, biochemical and flow cytometric techniques. OA effects on the cells included incorporation of propidium iodide, externalization of phosphatidylserine, and development of hypodiploidy. 308 cells demonstrated typical DNA ladder formation, rapid chromatin and nuclear condensation, while C50 cells demonstrated delayed chromatin condensation and nuclear fragmentation, but no DNA ladder formation. In vivo, OA elicited delayed papilloma formation and reduced tumor multiplicity. Though its mechanism of action is not fully known, we found that OA-induced inhibition of the clonal expansion of initiated cells may be related to the presence or absence of H-ras mutation.
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Affiliation(s)
- J Abiodun Elegbede
- Chemistry Department and UNLV Cancer Institute, University of Nevada Las Vegas, 4505 Maryland Parkway, Las Vegas, NV 89154-4003, USA.
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Tsutsumi S, Tomisato W, Hoshino T, Tsuchiya T, Mizushima T. Transforming growth factor-beta1 is responsible for maturation-dependent spontaneous apoptosis of cultured gastric pit cells. Exp Biol Med (Maywood) 2002; 227:402-11. [PMID: 12037130 DOI: 10.1177/153537020222700606] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
In this study, we established a system of high concentration serum-dependent spontaneous apoptosis of guinea pig gastric pit cells in primary culture, which seems to mimic the spontaneous apoptosis of matured gastric pit cells at gastric surface in vivo. In addition to induction of the spontaneous apoptosis, cell growth was inhibited in the presence of 10% serum compared with 0.5% serum. Transforming growth factor-beta1 (TGF-beta1), which is known to cause both apoptosis and growth inhibition in mammalian cells, was present in serum of both fetal calf and guinea pig. The addition of recombinant TGF-beta1 to the culture medium containing 0.5% fetal calf serum caused both induction of apoptosis and inhibition of cell growth. On the other hand, immunodepletion of TGF-beta1 from fetal calf serum caused inability to induce both the spontaneous apoptosis and inhibition of cell growth. These data suggest that TGF-beta1 is involved in the spontaneous apoptosis of guinea pig gastric pit cells in primary culture.
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Affiliation(s)
- Shinji Tsutsumi
- Faculty of Pharmaceutical Sciences, Okayama University, Okayama 700-8530, Japan
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Kapila YL, Wang S, Dazin P, Tafolla E, Mass MJ. The heparin-binding domain and V region of fibronectin regulate apoptosis by suppression of p53 and c-myc in human primary cells. J Biol Chem 2002; 277:8482-91. [PMID: 11751853 DOI: 10.1074/jbc.m108932200] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In apoptosis the tumor suppressor p53 and the c-myc proto-oncogene are usually up-regulated. We show a novel alternative pathway of apoptosis in human primary cells that is mediated by transcriptionally dependent decreases in p53 and c-Myc and decreases in p21. This pathway is regulated by the alternatively spliced V region and high-affinity heparin-binding domain of fibronectin. Requirements for c-Myc, p53, and p21 signals in maintaining survival and for their decreases in inducing apoptosis were demonstrated by the ability of p53, c-Myc, and p21 ectopic expression to rescue this apoptotic phenotype, and the ability of p53-deficient and c-myc antisense conditions to trigger a faster rate of apoptosis.
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Affiliation(s)
- Yvonne L Kapila
- Department of Stomatology, School of Dentistry, University of California San Francisco, San Francisco, California 94143, USA.
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23
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Laytragoon-Lewin N, Rossmann ED, Castro J, Mellstedt H. Significance of phosphotyrosine proteins, Bcl-2 and p53 for apoptosis in resting B-chronic lymphocytic leukemia (CLL) cells. Int J Cancer 2002; 97:344-8. [PMID: 11774286 DOI: 10.1002/ijc.1616] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Signal transduction and apoptosis in B-cell chronic lymphocytic leukemia (CLL) cells with a post-germinal center (GC) phenotype were studied. Specific activation of the cells was induced by a combination of soluble anti-CD40 monoclonal antibody and interleukin-4 (CD40/IL-4) and nonspecific activation with a combination of phytohemagglutinin, phorbol-12-myristate-13-acetate and ionomycin (chemical mixture). Less than 5% of these leukemia cells entered the cell cycle after activation, as indicated by the number of cells in G0/G1 phase. The protein tyrosine phosphorylation pattern and expression of the Bcl-2 protein were specific in ex vivo CLL cells of each individual patient. Expression of the p53 protein was not detectable in these leukemia cells. Cross-linking of the CD40/IL-4 receptors on CLL cells significantly upregulated phosphotyrosine proteins and the p53 protein. In the presence of chemical mixture, downregulated phosphotyrosine proteins were detected. Alterations in Bcl-2 expression were independent of cross-linking with CD40/IL-4 or chemical mixture. A high frequency of apoptotic cells was detected in cells that had downregulated phosphotyrosine proteins and Bcl-2 protein. There was no correlation between induction of apoptosis and expression of p53 protein. Our results suggest that apoptosis in resting leukemia cells could occur prior to the cell cycle progression. Alterations in phosphotyrosine proteins and Bcl-2 but not p53 might play an important role in the regulation of apoptosis in resting G0/G1 memory post-GC B-CLL cells.
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Affiliation(s)
- Nongnit Laytragoon-Lewin
- Department of Oncology Research Laboratory, Clinical Research Center, Huddinge University Hospital, SE-141 86 Stockholm, Sweden.
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Span L, Pennings A, Vierwinden G, Boezeman J, Raymakers R, de Witte T. The dynamic process of apoptosis analyzed by flow cytometry using Annexin-V/propidium iodide and a modified in situ end labeling technique. ACTA ACUST UNITED AC 2001. [DOI: 10.1002/cyto.10028] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Eray M, Mättö M, Kaartinen M, Andersson L, Pelkonen J. Flow cytometric analysis of apoptotic subpopulations with a combination of annexin V-FITC, propidium iodide, and SYTO 17. CYTOMETRY 2001; 43:134-42. [PMID: 11169578 DOI: 10.1002/1097-0320(20010201)43:2<134::aid-cyto1028>3.0.co;2-l] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND We have previously characterized apoptotic cell death induced in a follicular lymphoma cell line, HF-1, after triggering via the B-cell receptor (BCR) or treatment with Ca(2+) Ionophore A23187. We analyzed the kinetics of apoptosis induced by these two treatments, as two alternative models of classical apoptosis, by flow cytometry using a novel combination of cytofluorometric stains. METHODS Cells were stained with a combination of Annexin V-FITC, propidium iodide (PI), and SYTO 17 and analyzed by a two-laser flow cytometry system using 488-nm argon and 633-nm HeNe air-cooled lasers. RESULTS In both apoptotic models, the first apoptotic cells were detected by SYTO 17 staining. The alteration in SYTO 17 staining intensity was followed by an increased uptake of PI. Finally, the apoptotic cells were labeled with Annexin V in BCR-induced apoptosis. On the contrary, on treatment with Ca(2+) Ionophore A23187, cells became positive for Annexin V earlier than for PI. CONCLUSIONS The novel cytofluorometric dye, SYTO 17, discriminates apoptotic alterations before Annexin V and PI. PI also discriminates apoptotic alterations before the loss of plasma membrane asymmetry by BCR but not by Ca(2+) Ionophore A23187-induced apoptosis. Finally, the combination of these three cytofluorometric dyes allows effective detection of apoptotic subpopulations and ordering of apoptotic events by flow cytometry.
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Affiliation(s)
- M Eray
- Department of Pathology, Haartman Institute, University of Helsinki, Helsinki, Finland.
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26
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Abstract
The balance between cell survival and death is under tight genetic control. A multiplicity of extracellular signals and intracellular mediators is involved in maintaining this balance. When the cell is exposed to physical, biochemical or biological injury, or deprived of necessary substances, it activates a series of stress-response genes. With minimal insults, the cell may recover. With greater insults, single cell death, or apoptosis, results; the cell dies and is recycled to its neighbours. If the insult overwhelms a large number of cells then necrosis ensues, with an accompanying inflammatory response. Dysregulation of the controlling mechanisms of this system results in disease. Deficient apoptosis is associated with cancer, auto-immunity and viral infections. Excessive apoptosis is associated with ischaemic heart disease, stroke, neurodegenerative disease, sepsis and multiple organ dysfunction syndrome. There are myriad therapeutic options unfolding as understanding is gained of apoptosis and its control.
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Affiliation(s)
- P C Kam
- Department of Anaesthesia and Pain Management, University of Sydney, Royal North Shore Hospital, St Leonards, NSW 2065, Australia
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Komarova SV, Ataullakhanov FI, Globus RK. Bioenergetics and mitochondrial transmembrane potential during differentiation of cultured osteoblasts. Am J Physiol Cell Physiol 2000; 279:C1220-9. [PMID: 11003602 DOI: 10.1152/ajpcell.2000.279.4.c1220] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To evaluate the relationship between osteoblast differentiation and bioenergetics, cultured primary osteoblasts from fetal rat calvaria were grown in medium supplemented with ascorbate to induce differentiation. Before ascorbate treatment, the rate of glucose consumption was 320 nmol. h(-1). 10(6) cells(-1), respiration was 40 nmol. h(-1). 10(6) cells(-1), and the ratio of lactate production to glucose consumption was approximately 2, indicating that glycolysis was the main energy source for immature osteoblasts. Ascorbate treatment for 14 days led to a fourfold increase in respiration, a threefold increase in ATP production, and a fivefold increase in ATP content compared with that shown in immature cells. Confocal imaging of mitochondria stained with a transmembrane potential-sensitive vital dye showed that mature cells possessed abundant amounts of high-transmembrane-potential mitochondria, which were concentrated near the culture medium-facing surface. Acute treatment of mature osteoblasts with metabolic inhibitors showed that the rate of glycolysis rose to maintain the cellular energy supply constant. Thus progressive differentiation coincided with changes in cellular metabolism and mitochondrial activity, which are likely to play key roles in osteoblast function.
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Affiliation(s)
- S V Komarova
- Life Sciences Division, NASA Ames Research Center, Moffett Field, California 94035-1000, USA
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Chauhan D, Pandey P, Hideshima T, Treon S, Raje N, Davies FE, Shima Y, Tai YT, Rosen S, Avraham S, Kharbanda S, Anderson KC. SHP2 mediates the protective effect of interleukin-6 against dexamethasone-induced apoptosis in multiple myeloma cells. J Biol Chem 2000; 275:27845-50. [PMID: 10880513 DOI: 10.1074/jbc.m003428200] [Citation(s) in RCA: 146] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Our previous studies have shown that activation of a related adhesion focal tyrosine kinase (RAFTK) (also known as Pyk2) is required for dexamethasone (Dex)-induced apoptosis in multiple myeloma (MM) cells and that human interleukin-6 (IL-6), a known growth and survival factor for MM cells, blocks both RAFTK activation and apoptosis induced by Dex. However, the mechanism whereby IL-6 inhibits Dex-induced apoptosis is undefined. In this study, we demonstrate that protein-tyrosine phosphatase SHP2 mediates this protective effect. We show that IL-6 triggers selective activation of SHP2 and its association with RAFTK in Dex-treated MM cells. SHP2 interacts with RAFTK through a region other than its Src homology 2 domains. We demonstrate that RAFTK is a direct substrate of SHP2 both in vitro and in vivo, and that Tyr(906) in the C-terminal domain of RAFTK mediates its interaction with SHP2. Moreover, overexpression of dominant negative SHP2 blocked the protective effect of IL-6 against Dex-induced apoptosis. These findings demonstrate that SHP2 mediates the anti-apoptotic effect of IL-6 and suggest SHP2 as a novel therapeutic target in MM.
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Affiliation(s)
- D Chauhan
- Department of Adult Oncology, Dana-Farber Cancer Institute, Division of Experimental Medicine and Hematology/Oncology, Beth Israel Deaconess Medical Center, Harvard Institutes of Medicine and Harvard Medical School, Boston, Massachusetts 02115, USA
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29
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Neves I, Morgado M. Immunological evaluation of human immunodeficiency virus infected individuals by flow cytometry. Mem Inst Oswaldo Cruz 2000; 95:393-400. [PMID: 10800198 DOI: 10.1590/s0074-02762000000300016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Human immunodeficiency virus (HIV) infection heavily compromises the immune system. The decrease of the T cell CD4+ subset along the evolution to acquired immunodeficiency syndrome has been considered as a hallmark of HIV infection. In this paper we review some aspects of the immunopathology of HIV infection and discuss the importance of the flow cytometry for the evaluation of the T lymphocyte subsets in the follow-up of HIV infected children and adults, and for the monitoring of the immune reconstitution upon antiretroviral therapy.
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Affiliation(s)
- I Neves
- Laboratório de Aids e Imunologia Molecular, Departamento de Imunologia, Instituto Oswaldo Cruz, Rio de Janeiro, Brasil
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30
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Wiltshire M, Patterson LH, Smith PJ. A novel deep red/low infrared fluorescent flow cytometric probe, DRAQ5NO, for the discrimination of intact nucleated cells in apoptotic cell populations. CYTOMETRY 2000; 39:217-23. [PMID: 10685079 DOI: 10.1002/(sici)1097-0320(20000301)39:3<217::aid-cyto7>3.0.co;2-m] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND The linking of intracellular metabolism of anticancer drugs with cellular response is problematic. We describe a new probe for cellular integrity, based upon a structure which has the additional potential to act as a substrate for cytochrome P450-dependent bioreductive metabolism. DRAQ5NO is an N-oxide modified anthraquinone with optimal fluorescence excitation maxima compatible with He-Ne (633 nm) and Kr-Ar (647 nm) lasers. METHODS DRAQ5NO-loading and Annexin V binding was monitored using dual-laser flow cytometry (488 nm/633 nm wavelengths) in human lymphoma cultures undergoing anticancer drug- (etoposide; VP-16) induced apoptosis. RESULTS DRAQ5NO gave an Em(lambdamax) of 700.5 nm but retains DNA binding potential with an emission wavelength red-shift of approximately 12 nm. The agent showed reduced cytotoxicity and a limited capacity to accumulate within cells compared with the non-N-oxide form that shows a high nuclear targeting capacity in intact cells. DRAQ5NO/Annexin V provides for a positive discrimination between intact cells, membrane-compromised cells, cellular debris, and early stage apoptotic cells. CONCLUSIONS The spectral properties of DRAQ5NO allow for the use of visible range fluorochromes and differential excitation in multilaser systems for tracking apoptotic populations with implications for the measurement of bioreductive potential in complex tumour populations simultaneously undergoing physiologically or drug-induced apoptosis.
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Affiliation(s)
- M Wiltshire
- Department of Pathology, University of Wales College of Medicine, Heath Park, Cardiff, UK
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31
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Chauhan D, Hideshima T, Pandey P, Treon S, Teoh G, Raje N, Rosen S, Krett N, Husson H, Avraham S, Kharbanda S, Anderson KC. RAFTK/PYK2-dependent and -independent apoptosis in multiple myeloma cells. Oncogene 1999; 18:6733-40. [PMID: 10597281 DOI: 10.1038/sj.onc.1203082] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Related Adhesion Focal Tyrosine Kinase (RAFTK; also known as Pyk2), is a member of the Focal Adhesion Kinase (FAK) subfamily and is activated by TNF alpha, UV light and increases in intracellular calcium levels. However, the function of RAFTK remains largely unknown. Our previous studies demonstrated that treatment with dexamethasone (Dex), ionizing radiation (IR), and anti-Fas mAb induces apoptosis in multiple myeloma (MM) cells. In the present study, we examined the potential role of RAFTK during induction of apoptosis in human MM cells triggered by these three stimuli. Dex-induced apoptosis, in contrast to apoptosis triggered by anti-Fas mAb or IR, is associated with activation of RAFTK. Transient overexpression of RAFTK wild type (RAFTK WT) induces apoptosis, whereas transient overexpression of Kinase inactive RAFTK (RAFTK K-M) blocks Dex-induced apoptosis. In contrast, transient overexpression of RAFTK K-M has no effect on apoptosis triggered by IR or Fas. In Dex-resistant cells, Dex does not trigger either RAFTK activation or apoptosis. Finally, interleukin-6 (IL-6), a known survival factor for MM cells, inhibits both activation of RAFTK and apoptosis of MM.1S cells triggered by Dex. Our studies therefore demonstrate Dex-induced RAFTK-dependent, and IR or Fas induced RAFTK-independent apoptotic signaling cascades in MM cells.
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Affiliation(s)
- D Chauhan
- Department of Adult Oncology, Dana Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA
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Matteucci C, Grelli S, De Smaele E, Fontana C, Mastino A. Identification of nuclei from apoptotic, necrotic, and viable lymphoid cells by using multiparameter flow cytometry. CYTOMETRY 1999; 35:145-53. [PMID: 10554170 DOI: 10.1002/(sici)1097-0320(19990201)35:2<145::aid-cyto6>3.0.co;2-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Methods widely used to detect apoptosis do not allow us to easily distinguish between nuclei from viable or necrotic cells. Even if apoptosis and necrosis seem to occur as alternatives at the single cell level, they could be present simultaneously in a cell population much more frequently than expected. For this reason, attention was focused on attempting to recognize, by multiparameter flow cytometry, the characteristics of viable cells and of apoptotic or necrotic dead cells. METHODS Apoptosis and necrosis were induced in vitro in murine thymocytes and lymphocytes from adult peripheral blood by using dexamethasone or prostaglandin E2 treatment and heat shock at 60 degrees C or hydrogen peroxide, respectively. Traditional methods, such as DNA gel electrophoresis and propidium iodide staining followed by single-fluorescence analysis or annexin-V-fluorescein isothiocyanate plus propidium iodide staining by using flow cytometry, were compared with a new method. This method consisted of combined light-scatter and red fluorescence analysis by flow cytometry after isolation of nuclei by hypotonic solution as well as high-dose detergent treatment and DNA staining with propidium iodide. RESULTS Results showed that, although traditional methods such as DNA-gel electrophoresis and single-parameter fluorescence flow cytometry analysis were unable, as expected, to discriminate among viability, apoptosis, and necrosis, our new method has enabled us to easily identify nuclei from viable, apoptotic, and necrotic cells. Results obtained by using our method were comparable to those obtained by using two-color analysis of cells after propidium iodide/annexin V staining. CONCLUSIONS A highly reproducible, inexpensive, rapid, and easily accessible method of analysis has been developed for simultaneously detecting apoptosis and necro sis.
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Affiliation(s)
- C Matteucci
- Department of Experimental Medicine and Biochemical Sciences, University of Rome Tor Vergata, Italy
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Ilić D, Almeida EA, Schlaepfer DD, Dazin P, Aizawa S, Damsky CH. Extracellular matrix survival signals transduced by focal adhesion kinase suppress p53-mediated apoptosis. J Cell Biol 1998; 143:547-60. [PMID: 9786962 PMCID: PMC2132850 DOI: 10.1083/jcb.143.2.547] [Citation(s) in RCA: 376] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/1998] [Revised: 09/03/1998] [Indexed: 11/22/2022] Open
Abstract
In many malignant cells, both the anchorage requirement for survival and the function of the p53 tumor suppressor gene are subverted. These effects are consistent with the hypothesis that survival signals from extracellular matrix (ECM) suppress a p53-regulated cell death pathway. We report that survival signals from fibronectin are transduced by the focal adhesion kinase (FAK). If FAK or the correct ECM is absent, cells enter apoptosis through a p53-dependent pathway activated by protein kinase C lambda/iota and cytosolic phospholipase A2. This pathway is suppressible by dominant-negative p53 and Bcl2 but not CrmA. Upon inactivation of p53, cells survive even if they lack matrix signals or FAK. This is the first report that p53 monitors survival signals from ECM/FAK in anchorage- dependent cells.
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Affiliation(s)
- D Ilić
- Departments of Stomatology and Anatomy, University of California San Francisco, San Francisco, California 94143-0512, USA
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Cook T, Gebelein B, Mesa K, Mladek A, Urrutia R. Molecular cloning and characterization of TIEG2 reveals a new subfamily of transforming growth factor-beta-inducible Sp1-like zinc finger-encoding genes involved in the regulation of cell growth. J Biol Chem 1998; 273:25929-36. [PMID: 9748269 DOI: 10.1074/jbc.273.40.25929] [Citation(s) in RCA: 159] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Sp1-like zinc finger transcription factors are involved in the regulation of cell growth and differentiation. Recent evidence demonstrating that mammalian cells express novel, yet uncharacterized, Sp1-like proteins has stimulated a search for new members of this family. We and others have recently reported that the transforming growth factor (TGF)-beta-regulated gene TIEG encodes a new Sp1-like protein that inhibits cell growth in cultured cells. Here we report the identification, nuclear localization, DNA binding activity, transcriptional repression activity, and growth inhibitory effects of TIEG2, a novel TGF-beta-inducible gene related to TIEG. TIEG2 is ubiquitously expressed in human tissues, with an enrichment in pancreas and muscle. TIEG2 shares 91% homology with TIEG1 within the zinc finger region and 44% homology within the N terminus. Biochemical characterization reveals that TIEG2 is a nuclear protein, which, as predicted from the primary structure, specifically binds to an Sp1-like DNA sequence in vitro and can repress a promoter containing Sp1-like binding sites in transfected Chinese hamster ovary epithelial cells. Furthermore, functional studies using [3H]thymidine uptake and MTS (3-(4, 3-dimethyltiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-su lfophenyl)-2 H-tetrazolium) assays demonstrate that the overexpression of TIEG2 in Chinese hamster ovary cells inhibits cell proliferation. Thus, TIEG2, together with TIEG1, defines a new subfamily of TGF-beta-inducible Sp1-like proteins involved in the regulation of cell growth.
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Affiliation(s)
- T Cook
- Gastroenterology Research Unit, Saint Marys Hospital, Mayo Clinic, Rochester, Minnesota 55905, USA
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35
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Abstract
Apoptosis, often synonymously used with the term 'programmed cell death', is an active, genetically controlled process that removes unwanted or damaged cells. Suppression, overexpression or mutation of a number of genes which orchestrate the apoptotic process are associated with disease. The diseases in which apoptosis has been implicated can be grouped into 2 broad groups: those in which there is increased cell survival (i.e. associated with inhibition of apoptosis) and those in which there is excess cell death (where apoptosis is overactive). Diseases in which there is an excessive accumulation of cells include cancer, autoimmune disorders and viral infections. Deprivation of trophic factors is known to induce apoptosis in cells dependent on them for survival. This fact has been exploited in the use of antiandrogens or antiestrogens in the management of prostate or breast cancer. Haemopoietic growth factors like granulocyte-macrophage colony stimulating factor (GM-CSF) or interleukin-3 prevent apoptosis in target cells and modulation of levels of these factors has been tried in the prevention of chemotherapy-induced myelosuppression. Until recently, it was thought that cytotoxic drugs killed target cells directly by interfering with some life-maintaining function. However, of late, it has been shown that exposure to several cytotoxic drugs with disparate mechanisms of action induces apoptosis in both malignant and normal cells. Physiological regulation of cell death is essential for the removal of potentially autoreactive lymphocytes during development and the removal of excess cells after the completion of an immune response. Recent work has clearly demonstrated that dysregulation of apoptosis may underlie the pathogenesis of autoimmune diseases by allowing abnormal autoreactive lymphocytes to survive. AIDS and neurodegenerative disorders like Alzheimer's or Parkinson's disease represent the most widely studied group of disorders where an excess of apoptosis has been implicated. Amyotrophic lateral sclerosis, retinitis pigmentosa, epilepsy and alcoholic brain damage are other neurological disorders in which apoptosis has been implicated. Apoptosis has been reported to occur in conditions characterised by ischaemia, e.g. myocardial infarction and stroke. The liver is a site where apoptosis occurs normally. This process has also been implicated in a number of liver disorders including obstructive jaundice. Hepatic damage due to toxins and drugs is also associated with apoptosis in hepatocytes. Apoptosis has also been identified as a key phenomenon in some diseases of the kidney, i.e. polycystic kidney, as well as in disorders of the pancreas like alcohol-induced pancreatitis and diabetes.
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Affiliation(s)
- U Thatte
- Department of Pharmacology, Seth GS Medical College, Mumbai, India.
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