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Alhazmi A, Sidney LE, Hopkinson A, Elsheikha HM. Comparative cytotoxicity of Acanthamoeba castellanii-derived conditioned medium on human corneal epithelial and stromal cells. Acta Trop 2024; 257:107288. [PMID: 38901524 DOI: 10.1016/j.actatropica.2024.107288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Revised: 06/10/2024] [Accepted: 06/11/2024] [Indexed: 06/22/2024]
Abstract
Soluble factors in the secretome of Acanthamoeba castellanii play crucial roles in the pathogenesis of Acanthamoeba keratitis (AK). Investigating the pathological effects of A. castellanii-derived conditioned medium (ACCM) on ocular cells can provide insights into the damage inflicted during AK. This study examined ACCM-induced cytotoxicity in primary human corneal stromal cells (CSCs) and a human SV40 immortalized corneal epithelial cell line (ihCECs) at varying ACCM concentrations (25 %, 50 %, 75 %, and 100 %). MTT, AlamarBlue, Sulforhodamine B, lactate dehydrogenase, and Caspase-3/7 activation assays were used to assess the impact of ACCM on the cell viability, proliferation and apoptosis. Additionally, fluorescent staining was used to reveal actin cytoskeleton changes. ACCM exposure significantly decreased cell viability, increased apoptosis, and disrupted the actin cytoskeleton, particularly at higher concentrations and longer exposures. Proteases were found to mediate these cytopathogenic effects, highlighting the need for characterization of A. castellanii proteases as key virulence factors in AK pathogenesis.
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Affiliation(s)
- Abdullah Alhazmi
- Academic Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham NG7 2UH, UK; Faculty of Public Health and Health Informatics, Umm Al Qura University, Makkah, Saudi Arabia
| | - Laura E Sidney
- Academic Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham NG7 2UH, UK
| | - Andy Hopkinson
- Academic Ophthalmology, Division of Clinical Neuroscience, University of Nottingham, Nottingham NG7 2UH, UK
| | - Hany M Elsheikha
- Faculty of Medicine and Health Sciences, School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK.
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Palanivel S, Zhurina A, Doan P, Chandraseelan JG, Khandelwal VKM, Zubkov FI, Mahmudov KT, Pombeiro AJ, Yli-Harja O, Kandhavelu M. In vitro characterization of arylhydrazones of active methylene derivatives. Saudi Pharm J 2018; 26:430-436. [PMID: 29556135 PMCID: PMC5856940 DOI: 10.1016/j.jsps.2017.12.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 12/26/2017] [Indexed: 01/21/2023] Open
Abstract
Arylhydrazones of active methylene compounds (AHAMCs) are potent chemotherapy agents for the cancer treatment. AHAMCs enhance the apoptotic cell death and antiproliferation properties in cancer cells. In this study, a series of AHAMCs, 13 compounds, was assayed for cytotoxicity, apoptosis, externalization of phosphatidylserine, heterogeneity and cellular calcium level changes. The in vitro cytotoxicity study against HEK293T cells suggests that AHAMCs have significant cytotoxic effect over the concentrations. Top 5 compounds, 5-(2-(2-hydroxyphenyl) hydrazono)pyrimidine-2,4,6(1H,3H,5H)-trione (5), 4-hydroxy-5-(2-(2,4,6-trioxo-tetrahydro-pyrimidin-5(6H) ylidene)hydrazinyl)benzene-1,3-disulfonic acid (6), 5-chloro-3-(2-(4,4-dimethyl-2,6-dioxocyclohexylidene)hydrazinyl)-2-hydroxybenzenesulfonic acid (8), 5-(2-(4,4-dimethyl-2,6-dioxocyclohexylidene)hydrazinyl)-4-hydroxybenzene-1,3-disulfonic acid (9) and 2-(2-sulfophenylhydrazo)malononitrile (10) were chosen for the pharmacodynamics study. Among these, compound 5 exhibited the better cytotoxic effect with the IC50 of 50.86 ± 2.5 mM. DNA cleavage study revealed that 5 induces cell death through apoptosis and shows more effects after 24 and/or 48 h. Independent validation of apoptosis by following the externalization of phosphatidylserine using Annexin-V is also in agreement with the potential activity of 5. Single cell image analysis of Annexin-V bound cells confirms the presence of mixture of early, mid and late apoptotic cells in the population of the cells treated with 5 and a decreased trend in cell-to-cell variation over the phase was also identified. Additionally, intracellular calcium level measurements identified the Ca2+ up-regulation in compound treated cells. A brief inspection of the effect of the compound 5 against multiple human brain astrocytoma cells showed a better cell growth inhibitory effect at micro molar level. These systematic studies provide insights in the development of novel AHAMACs compounds as potential cell growth inhibitors for cancer treatment.
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Affiliation(s)
- Suresh Palanivel
- Molecular Signaling Lab, CSB, BioMediTech Institute and Faculty of Biomedical Sciences and Engineering, Tampere University of Technology, P.O. Box 553, 33101 Tampere, Finland
| | - Anastasia Zhurina
- Molecular Signaling Lab, CSB, BioMediTech Institute and Faculty of Biomedical Sciences and Engineering, Tampere University of Technology, P.O. Box 553, 33101 Tampere, Finland
| | - Phuong Doan
- Molecular Signaling Lab, CSB, BioMediTech Institute and Faculty of Biomedical Sciences and Engineering, Tampere University of Technology, P.O. Box 553, 33101 Tampere, Finland
| | - Jerome G. Chandraseelan
- Molecular Signaling Lab, CSB, BioMediTech Institute and Faculty of Biomedical Sciences and Engineering, Tampere University of Technology, P.O. Box 553, 33101 Tampere, Finland
| | | | - Fedor I. Zubkov
- Organic Chemistry Department, RUDN University, 6 Miklukho-Maklaya St., Moscow 117198, Russian Federation
| | - Kamran T. Mahmudov
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
- Department of Ecology and Soil Sciences, Baku State University, Z. Xalilov Str. 23, Az 1148 Baku, Azerbaijan
| | - Armando J.L. Pombeiro
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - Olli Yli-Harja
- Computational Systems Biology Group, BioMediTech Institute and Faculty of Biomedical Sciences and Engineering, Tampere University of Technology, P.O. Box 553, 33101 Tampere, Finland
| | - Meenakshisundaram Kandhavelu
- Molecular Signaling Lab, CSB, BioMediTech Institute and Faculty of Biomedical Sciences and Engineering, Tampere University of Technology, P.O. Box 553, 33101 Tampere, Finland
- Corresponding author.
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Acanthamoeba castellanii Genotype T4 Stimulates the Production of Interleukin-10 as Well as Proinflammatory Cytokines in THP-1 Cells, Human Peripheral Blood Mononuclear Cells, and Human Monocyte-Derived Macrophages. Infect Immun 2016; 84:2953-62. [PMID: 27481240 PMCID: PMC5038060 DOI: 10.1128/iai.00345-16] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 07/24/2016] [Indexed: 12/11/2022] Open
Abstract
Free-living amoebae of the genus Acanthamoeba can cause severe and chronic infections in humans, mainly localized in immune privileged sites, such as the brain and the eye. Monocytes/macrophages are thought to be involved in Acanthamoeba infections, but little is known about how these facultative parasites influence their functions. The aim of this work was to investigate the effects of Acanthamoeba on human monocytes/macrophages during the early phase of infection. Here, THP-1 cells, primary human monocytes isolated from peripheral blood, and human monocyte-derived macrophages were either coincubated with trophozoites of a clinical isolate of Acanthamoeba (genotype T4) or stimulated with amoeba-derived cell-free conditioned medium. Production of proinflammatory cytokines (tumor necrosis factor alpha [TNF-α], interleukin-6 [IL-6], and IL-12), anti-inflammatory cytokine (IL-10), and chemokine (IL-8) was evaluated at specific hours poststimulation (ranging from 1.5 h to 23 h). We showed that both Acanthamoeba trophozoites and soluble amoebic products induce an early anti-inflammatory monocyte-macrophage phenotype, characterized by significant production of IL-10; furthermore, challenge with either trophozoites or their soluble metabolites stimulate both proinflammatory cytokines and chemokine production, suggesting that this protozoan infection results from the early induction of coexisting, opposed immune responses. Results reported in this paper confirm that the production of proinflammatory cytokines and chemokines by monocytes and macrophages can play a role in the development of the inflammatory response during Acanthamoeba infections. Furthermore, we demonstrate for the first time that Acanthamoeba stimulates IL-10 production in human innate immune cells, which might both promote the immune evasion of Acanthamoeba and limit the induced inflammatory response.
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Li X, Li PCH. Strategies for the real-time detection of Ca2+ channel events of single cells: recent advances and new possibilities. Expert Rev Clin Pharmacol 2012; 3:267-80. [PMID: 22111609 DOI: 10.1586/ecp.10.16] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Ca(2+) ion channels play key roles in cell physiology and they are important drug targets. The Ca(2+) channel events are mainly measurable by fluorescent and patch clamp methods. This review summarizes the recent advances of these techniques for the detection of Ca(2+) channel events and the prospect of their new directions in the near future. Conventional bulk fluorescent methods are amenable to high-throughput applications, but they are not real-time single-cell measurements, which provide kinetic data on individual cells and offer unparalleled sensitive data for rare cells. Recent advances on real-time single-cell fluorescent measurements are conducted on microfluidic chips with scalable cell-retention sites, integrated with electrical stimulation and fluorescent measuring features. Patch clamp techniques are real-time measurements conducted on single cells, but the measurements are of low throughput. Recent advances are conducted on microfluidic patch clamp chips for high-throughput applications. Future real-time single-cell Ca(2+) channel event measurements will be conducted in a multiparametric manner in an integrated and automated microfluidic chip.
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Affiliation(s)
- XiuJun Li
- University of California at Berkeley, CA 94720, USA
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Elsheikha HM, Khan NA. Protozoa traversal of the blood–brain barrier to invade the central nervous system. FEMS Microbiol Rev 2010; 34:532-53. [DOI: 10.1111/j.1574-6976.2010.00215.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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Thai Acanthamoeba isolate (T4) induced apoptotic death in neuroblastoma cells via the Bax-mediated pathway. Parasitol Int 2010; 59:512-6. [PMID: 20601106 DOI: 10.1016/j.parint.2010.06.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2010] [Revised: 06/05/2010] [Accepted: 06/15/2010] [Indexed: 11/21/2022]
Abstract
A Thai Acanthamoeba isolate named AS recovered from a corneal scraping of a keratitis patient was genotypically determined as T4. AS trophozoites were used for studying Acanthamoeba-induced apoptosis in mouse neuroblastoma NA cells during in vitro co-cultivation. The Acanthamoeba-exposed NA cells showed signs of apoptosis including cell shrinkage, nuclear condensation and DNA fragmentation. The effect was confirmed by DNA laddering electrophoresis. Involvement of caspase enzymes and mitochondrial pro- and anti-apoptotic proteins (Bax and Bcl-2) in AS-induced apoptosis was determined. The use of Z-VAD-FMK, a pan-caspase inhibitor, significantly reduced the apoptotic effect, while Bax/Bcl-2 ratio analysis showed a significant increase in the expression of apoptotic proteins in AS-exposed NA cells. These results strongly indicated that apoptosis induced by AS trophozoites is caspase-dependent and is mediated by over-expression of pro-apoptotic proteins in the mitochondrial pathway. This is the first report on the role of Bax in mediating apoptosis induced by Acanthamoeba.
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In vitro activity of Acanthamoeba castellanii on human platelets and erythrocytes. Infect Immun 2008; 77:733-8. [PMID: 19015256 DOI: 10.1128/iai.00202-08] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The effect of Acanthamoeba on human platelets and erythrocytes has not been fully elucidated. This paper reports that cell-free supernatants prepared from A. castellanii can activate human platelets, causing both a significant increase in the cytosolic free-calcium concentration and platelet aggregation. In addition, we demonstrated that platelet activation depends on the activity of ADP constitutively secreted into the medium by trophozoites. This study also showed that A. castellanii can affect human red blood cells, causing hemolysis, and provided evidence that hemolysis occurs in both contact-dependent and contact-independent ways; there are differences in kinetics, hemolytic activity, and calcium dependency between the contact-dependent and contact-independent mechanisms. Partial characterization of contact-independent hemolysis indicated that ADP does not affect the plasma membrane permeability of erythrocytes and that heat treatment of amoebic cell-free supernatant abolishes its hemolytic activity. These findings suggest that some heat-labile molecules released by A. castellanii trophozoites are involved in this phenomenon. Finally, our data suggest that human platelets and erythrocytes may be potential cell targets during Acanthamoeba infection.
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Khan NA. Acanthamoeba invasion of the central nervous system. Int J Parasitol 2007; 37:131-8. [PMID: 17207487 DOI: 10.1016/j.ijpara.2006.11.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2006] [Revised: 11/09/2006] [Accepted: 11/15/2006] [Indexed: 10/23/2022]
Abstract
Pathogenic Acanthamoeba are known to infect the CNS, resulting in fatal granulomatous encephalitis. The mechanisms associated with the pathogenesis remain unclear; however pathophysiological complications involving the CNS most likely include induction of pro-inflammatory responses, invasion of the blood-brain barrier and the connective tissue and neuronal damage leading to brain dysfunction. The routes of entry include the olfactory neuroepithelium pathway and/or lower respiratory tract, followed by haematogenous spread. Skin lesions may provide direct entry into the bloodstream, bypassing the lower respiratory tract. For the haematogenous route, entry of amoebae into the CNS most likely occurs at the sites of the blood-brain barrier. Recent studies have identified several molecular mechanisms associated with Acanthamoeba traversal of the blood-brain barrier and targeting those may help develop therapeutic interventions and/or design preventative strategies.
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Affiliation(s)
- Naveed Ahmed Khan
- School of Biological and Chemical Sciences, Birkbeck College, University of London, London WC1E 7HX, UK.
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Abstract
Acanthamoeba is an opportunistic protozoan that is widely distributed in the environment and is well recognized to produce serious human infections, including a blinding keratitis and a fatal encephalitis. This review presents our current understanding of the burden of Acanthamoeba infections on human health, their pathogenesis and pathophysiology, and molecular mechanisms associated with the disease, as well as virulence traits of Acanthamoeba that may be targets for therapeutic interventions and/or the development of preventative measures.
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Affiliation(s)
- Naveed Ahmed Khan
- School of Biological and Chemical Sciences, Birkbeck College, University of London, London, UK.
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Butler R, Nowak BF. In vitro interactions between Neoparamoeba sp. and Atlantic salmon epithelial cells. JOURNAL OF FISH DISEASES 2004; 27:343-349. [PMID: 15189374 DOI: 10.1111/j.1365-2761.2004.00550.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Neoparamoeba sp., including the putative aetiological agent of amoebic gill disease in cultured fish (N. pemaquidensis), were incubated in vitro with an Atlantic salmon gill epithelium (RGE-2) cell line. Proliferation by the amoeba population was dependent upon culture osmolarity; no growth occurred at 330 mm x kg(-1) but a sixfold increase was observed at 1000 mm x kg(-1). At 780 mm x kg(-1) there was a fourfold increase in the amoeba population but a concurrent decrease in RGE-2 cell density that was significantly greater than that caused by the high culture osmolarity alone. This apparent cytopathic effect (CPE) developed rapidly and resulted in complete cytolysis of the monolayer in 5 days. CPE occurred in multiple foci and presented as cell vacuolation, rounding and clumping, and the rapid clearance of large areas of the cell monolayer. The possibility that CPE is because of the presence of Neoparamoeba sp. derived cytolytic products is discussed in the context of the pathology of the disease in vivo and the occurrence of secreted cytopathogenic compounds in other amoeba species.
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Affiliation(s)
- R Butler
- Tasmanian Aquaculture and Fisheries Institute, School of Aquaculture, University of Tasmania, Tasmania, Australia.
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Abstract
Acanthamoeba are free-living, harmless organisms, however, given the opportunity and the appropriate conditions, they can cause painful, sight-threatening as well as fatal infections and, thus, are considered opportunistic pathogens. Acanthamoeba infections have become increasingly important in the past few years due to increasing populations of contact lens users and AIDS patients. The mechanisms associated with the pathogenesis of Acanthamoeba tend to be highly complex, depending on parasite, host and the environmental factors. Elucidation of the biochemical, cellular and molecular basis of the pathogenesis of diseases caused by Acanthamoeba may lead to the development of therapeutic interventions.
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Affiliation(s)
- Naveed Ahmed Khan
- School of Biological and Chemical Sciences, Birkbeck College, University of London, London WC1E 7HX, UK.
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12
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Abstract
Acanthamoeba spp. are free-living amebae that inhabit a variety of air, soil, and water environments. However, these amebae can also act as opportunistic as well as nonopportunistic pathogens. They are the causative agents of granulomatous amebic encephalitis and amebic keratitis and have been associated with cutaneous lesions and sinusitis. Immuno compromised individuals, including AIDS patients, are particularly susceptible to infections with Acanthamoeba. The immune defense mechanisms that operate against Acanthamoeba have not been well characterized, but it has been proposed that both innate and acquired immunity play a role. The ameba's life cycle includes an active feeding trophozoite stage and a dormant cyst stage. Trophozoites feed on bacteria, yeast, and algae. However, both trophozoites and cysts can retain viable bacteria and may serve as reservoirs for bacteria with human pathogenic potential. Diagnosis of infection includes direct microscopy of wet mounts of cerebrospinal fluid or stained smears of cerebrospinal fluid sediment, light or electron microscopy of tissues, in vitro cultivation of Acanthamoeba, and histological assessment of frozen or paraffin-embedded sections of brain or cutaneous lesion biopsy material. Immunocytochemistry, chemifluorescent dye staining, PCR, and analysis of DNA sequence variation also have been employed for laboratory diagnosis. Treatment of Acanthamoeba infections has met with mixed results. However, chlorhexidine gluconate, alone or in combination with propamidene isethionate, is effective in some patients. Furthermore, effective treatment is complicated since patients may present with underlying disease and Acanthamoeba infection may not be recognized. Since an increase in the number of cases of Acanthamoeba infections has occurred worldwide, these protozoa have become increasingly important as agents of human disease.
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Affiliation(s)
- Francine Marciano-Cabral
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, Virginia 23298-0678, USA.
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Mattana A, Cappai V, Alberti L, Serra C, Fiori PL, Cappuccinelli P. ADP and other metabolites released from Acanthamoeba castellanii lead to human monocytic cell death through apoptosis and stimulate the secretion of proinflammatory cytokines. Infect Immun 2002; 70:4424-32. [PMID: 12117953 PMCID: PMC128125 DOI: 10.1128/iai.70.8.4424-4432.2002] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Monocytes/macrophages are thought to be involved in Acanthamoeba infections. The aim of this work was to study whether soluble metabolites (ADP and other compounds) released by Acanthamoeba castellanii trophozoites could induce morphological and biochemical changes in human monocytic cells in vitro. We demonstrate here that ADP constitutively released in the medium by A. castellanii, interacting with specific P2y(2) purinoceptors expressed on the monocytic cell membrane, caused a biphasic rise in [Ca(2+)](i), morphological changes characteristics of cells undergoing apoptosis, caspase-3 activation, and secretion of tumor necrosis factor alpha (TNF-alpha). The same results were found in monocytes exposed to purified ADP. Cell damage and TNF-alpha release induced by amoebic ADP were blocked by the P2y(2) inhibitor suramin. Other metabolites contained in amoebic cell-free supernatants, with molecular masses of, respectively, >30 kDa and between 30 and 10 kDa, also caused morphological modifications and activation of intracellular caspase-3, characteristics of programmed cell death. Nevertheless, mechanisms by which these molecules trigger cell damage appeared to differ from that of ADP. In addition, other amoebic thermolable metabolites with molecular masses of <10 kDa caused the secretion of interleukin-1beta. These findings suggest that pathogenic free-living A. castellanii by release of ADP and other metabolites lead to human monocytic cell death through apoptosis and stimulate the secretion of proinflammatory cytokines.
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Affiliation(s)
- A Mattana
- Department of Pharmaceutical Sciences, University of Sassari, Italy.
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Mattana A, Tozzi MG, Costa M, Delogu G, Fiori PL, Cappuccinelli P. By releasing ADP, Acanthamoeba castellanii causes an increase in the cytosolic free calcium concentration and apoptosis in wish cells. Infect Immun 2001; 69:4134-40. [PMID: 11349088 PMCID: PMC98481 DOI: 10.1128/iai.69.6.4134-4140.2001] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The role played by soluble molecules that may participate in acanthamoebal cytopathogenicity has yet to be fully characterized. We demonstrate here that Acanthamoeba castellanii trophozoites constitutively release ADP in the medium. Cell-free supernatants prepared from A. castellanii, by interaction with specific P(2y2) purinoceptors expressed on the Wish cell membrane, caused a biphasic rise in [Ca(2+)](i), extensive cell membrane blebbing, cytoskeletal disorganization, and the breakdown of nuclei. Cell damage induced by amoebic supernatants was blocked by the P(2y2) inhibitor Suramin. The same results were found in Wish cells exposed to purified ADP. These findings suggest that pathogenic free-living A. castellanii may have a cytopathic effect on human epithelial cells through ADP release, by a process that begins with a rise of cytosolic free-calcium concentration, and culminates in apoptosis.
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Affiliation(s)
- A Mattana
- Department of Pharmacological Sciences, Division of Experimental and Clinical Microbiology, University of Sassari, Italy.
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