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Robinson JP, Ostafe R, Iyengar SN, Rajwa B, Fischer R. Flow Cytometry: The Next Revolution. Cells 2023; 12:1875. [PMID: 37508539 PMCID: PMC10378642 DOI: 10.3390/cells12141875] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 07/06/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023] Open
Abstract
Unmasking the subtleties of the immune system requires both a comprehensive knowledge base and the ability to interrogate that system with intimate sensitivity. That task, to a considerable extent, has been handled by an iterative expansion in flow cytometry methods, both in technological capability and also in accompanying advances in informatics. As the field of fluorescence-based cytomics matured, it reached a technological barrier at around 30 parameter analyses, which stalled the field until spectral flow cytometry created a fundamental transformation that will likely lead to the potential of 100 simultaneous parameter analyses within a few years. The simultaneous advance in informatics has now become a watershed moment for the field as it competes with mature systematic approaches such as genomics and proteomics, allowing cytomics to take a seat at the multi-omics table. In addition, recent technological advances try to combine the speed of flow systems with other detection methods, in addition to fluorescence alone, which will make flow-based instruments even more indispensable in any biological laboratory. This paper outlines current approaches in cell analysis and detection methods, discusses traditional and microfluidic sorting approaches as well as next-generation instruments, and provides an early look at future opportunities that are likely to arise.
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Affiliation(s)
- J Paul Robinson
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN 47907, USA
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Raluca Ostafe
- Molecular Evolution, Protein Engineering and Production Facility (PI4D), Purdue University, West Lafayette, IN 47907, USA
| | | | - Bartek Rajwa
- Bindley Bioscience Center, Purdue University, West Lafayette, IN 47907, USA
| | - Rainer Fischer
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA
- Purdue Institute of Inflammation, Immunology and Infectious Diseases, Purdue University, West Lafayette, IN 47907, USA
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2
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Schulte M, Hensel M. Flow Cytometry-Based Single Cell Analyses of Bacterial Adaptation to Intracellular Environments. Methods Mol Biol 2022; 2427:105-117. [PMID: 35619029 DOI: 10.1007/978-1-0716-1971-1_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Since decades, flow cytometry (FC) is a powerful technique to perform single cell analyses with high accuracy and throughput. Moreover, FC is the method of choice to study bacterial cell heterogeneity and complements single-cell imaging techniques. The complex experimental approaches for FC sample preparation and the subsequent FC adjustment and gating strategy demand careful considerations to be successful when analyzing complex microbial populations, especially when liberated populations of intracellular bacterial pathogens, or bacterial pathogens inside intact host cells are analyzed. Here, we provide a set of experimental protocols for FC sample preparation of (1) in vitro cultured bacterial cells, (2) liberated intracellular bacteria from host cells, or (3) preparation of intact infected phagocytic or epithelial cells commonly used as host cells in infection biology. Since sample preparation, cytometer adjustment, and gating strategy are essential for experimental success, we aim to provide our expertise to support application of FC by other researchers.
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Affiliation(s)
- Marc Schulte
- Abteilung Mikrobiologie and CellNanOs-Center of Cellular Nanoanalytics Osnabrück, Fachbereich Biologie/Chemie, Universität Osnabrück Barbarastr, Osnabrück, Germany
| | - Michael Hensel
- Abteilung Mikrobiologie and CellNanOs-Center of Cellular Nanoanalytics Osnabrück, Fachbereich Biologie/Chemie, Universität Osnabrück Barbarastr, Osnabrück, Germany.
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3
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Machine-learning algorithm incorporating capacitated sperm intracellular pH predicts conventional in vitro fertilization success in normospermic patients. Fertil Steril 2021; 115:930-939. [PMID: 33461755 DOI: 10.1016/j.fertnstert.2020.10.038] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 10/06/2020] [Accepted: 10/08/2020] [Indexed: 12/24/2022]
Abstract
OBJECTIVE To measure human sperm intracellular pH (pHi) and develop a machine-learning algorithm to predict successful conventional in vitro fertilization (IVF) in normospermic patients. DESIGN Spermatozoa from 76 IVF patients were capacitated in vitro. Flow cytometry was used to measure sperm pHi, and computer-assisted semen analysis was used to measure hyperactivated motility. A gradient-boosted machine-learning algorithm was trained on clinical data and sperm pHi and membrane potential from 58 patients to predict successful conventional IVF, defined as a fertilization ratio (number of fertilized oocytes [2 pronuclei]/number of mature oocytes) greater than 0.66. The algorithm was validated on an independent set of data from 18 patients. SETTING Academic medical center. PATIENT(S) Normospermic men undergoing IVF. Patients were excluded if they used frozen sperm, had known male factor infertility, or used intracytoplasmic sperm injection only. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) Successful conventional IVF. RESULT(S) Sperm pHi positively correlated with hyperactivated motility and with conventional IVF ratio (n = 76) but not with intracytoplasmic sperm injection fertilization ratio (n = 38). In receiver operating curve analysis of data from the test set (n = 58), the machine-learning algorithm predicted successful conventional IVF with a mean accuracy of 0.72 (n = 18), a mean area under the curve of 0.81, a mean sensitivity of 0.65, and a mean specificity of 0.80. CONCLUSION(S) Sperm pHi correlates with conventional fertilization outcomes in normospermic patients undergoing IVF. A machine-learning algorithm can use clinical parameters and markers of capacitation to accurately predict successful fertilization in normospermic men undergoing conventional IVF.
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Ventura C, Leon IE, Asuaje A, Martín P, Enrique N, Núñez M, Cocca C, Milesi V. Differential expression of the long and truncated Hv1 isoforms in breast-cancer cells. J Cell Physiol 2020; 235:8757-8767. [PMID: 32324259 DOI: 10.1002/jcp.29719] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 03/31/2020] [Accepted: 04/01/2020] [Indexed: 01/08/2023]
Abstract
Metabolic reprogramming of cancer cells results in a high production of acidic substances that must be extruded to maintain tumor-cell viability. The voltage-gated proton channel (Hv1) mediates highly selective effluxes of hydronium-ion (H+ ) that prevent deleterious cytoplasmic acidification. In the work described here, we demonstrated for the first time that the amino-terminal-truncated isoform of Hv1 is more highly expressed in tumorigenic breast-cancer-cell lines than in nontumorigenic breast cells. With respect to Hv1 function, we observed that pharmacologic inhibition of that channel, mediated by the specific blocker 5-chloro-2-guanidinobenzimidazole, produced a drop in intracellular pH and a decrease in cell viability, both in monolayer and in three-dimensional cultures, and adversely affected the cell-cycle in tumorigenic breast cells without altering the cycling of nontumorigenic cells. In conclusion, our results demonstrated that the Hv1 channel could be a potential tool both as a biomarker and as a therapeutic target in breast-cancer disease.
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Affiliation(s)
- Clara Ventura
- Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP), CONICET-UNLP, La Plata, Buenos Aires, Argentina.,Laboratorio de Radioisótopos, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Ignacio Esteban Leon
- Centro de Química Inorgánica (CEQUINOR), CONICET-UNLP, La Plata, Buenos Aires, Argentina
| | - Agustin Asuaje
- Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP), CONICET-UNLP, La Plata, Buenos Aires, Argentina
| | - Pedro Martín
- Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP), CONICET-UNLP, La Plata, Buenos Aires, Argentina
| | - Nicolas Enrique
- Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP), CONICET-UNLP, La Plata, Buenos Aires, Argentina
| | - Mariel Núñez
- Laboratorio de Radioisótopos, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Claudia Cocca
- Laboratorio de Radioisótopos, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Química y Fisicoquímica Biológica (IQUIFIB), CONICET-UBA, Buenos Aires, Argentina
| | - Verónica Milesi
- Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP), CONICET-UNLP, La Plata, Buenos Aires, Argentina
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Hu M, Zhao W, Li H, Gu J, Yan Q, Zhou X, Pan Z, Cui G, Jiao X. Immunization with recombinant Salmonella expressing SspH2-EscI protects mice against wild type Salmonella infection. BMC Vet Res 2018. [PMID: 29523140 PMCID: PMC5845362 DOI: 10.1186/s12917-018-1404-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Background Enhancing caspase-1 activation in macrophages is helpful for the clearance of intracellular bacteria in mice. Our previous studies have shown that EscI, an inner rod protein of type III system in E. coli can enhance caspase-1 activation. The purpose of this study was to further analyze the prospect of EscI in the vaccine design. Results A recombinant Salmonella expressing SspH2-EscI fusion protein using the promotor of Salmonella effector SspH2, X4550(pYA3334-P-SspH2-EscI), was constructed. A control recombinant Salmonella expressing SspH2 only X4550(pYA3334-P-SspH2) was also constructed. In the early stage of in vitro infection of mouse peritoneal macrophages, X4550(pYA3334-P-SspH2-EscI) could significantly (P < 0.05) enhance intracellular caspase-1 activation and pyroptotic cell death of macrophages, when compared with X4550(pYA3334-P-SspH2). Except for the intracellular pH value, the levels of reactive oxygen species, intracellular concentration of calcium ions, nitric oxide and mitochondrial membrane potential in macrophages were not significantly different between the cells infected with X4550(pYA3334-P-SspH2-EscI) and those infected with X4550(pYA3334-P-SspH2). Besides, only lower inflammatory cytokines secretion was induced by X4550(pYA3334-P-SspH2-EscI) than X4550(pYA3334-P-SspH2). After intravenous immunization of mice (1 × 106 cfu/mouse), the colonization of X4550(pYA3334-P-SspH2-EscI) in mice was significantly limited at one week post immunization (wpi), when compared with X4550(pYA3334-P-SspH2) (P < 0.05). The population of activated CD8+T lymphocytes in mouse spleens induced by X4550(pYA3334-P-SspH2-EscI) was lower than that induced by X4550(pYA3334-P-SspH2) at 2–3 wpi, and the ratio of CD4+T cells to CD8+T cells decreased. The blood coagulation assay indicated that no significant difference was found between X4550(pYA3334-P-SspH2-EscI) and uninfected control, while X4550(pYA3334-P-SspH2) could induce the quick coagulation. Notably, immunization of X4550(pYA3334-P-SspH2-EscI) could limit the colonization of challenged Salmonella strains in the early stage of infection and provide more effective protection. Conclusion The activation of caspase-1 in macrophages by EscI can be used in the design of live attenuated Salmonella vaccine candidate.
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Affiliation(s)
- Maozhi Hu
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, 225009, China. .,Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, 225009, China.
| | - Weixin Zhao
- College of Tourism & Cuisine (College of Food Science and Engineering), Yangzhou University, Yangzhou, Jiangsu, 225009, China
| | - Hongying Li
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, 225009, China
| | - Jie Gu
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, 225009, China
| | - Qiuxiang Yan
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, 225009, China
| | - Xiaohui Zhou
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, 225009, China.,Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, 225009, China.,Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, CT, 06269-3089, USA
| | - Zhiming Pan
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, 225009, China.,Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, 225009, China
| | - Guiyou Cui
- College of Tourism & Cuisine (College of Food Science and Engineering), Yangzhou University, Yangzhou, Jiangsu, 225009, China
| | - Xinan Jiao
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, 225009, China.,Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, Jiangsu, 225009, China
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Syeda SS, Sánchez G, Hong KH, Hawkinson JE, Georg GI, Blanco G. Design, Synthesis, and in Vitro and in Vivo Evaluation of Ouabain Analogues as Potent and Selective Na,K-ATPase α4 Isoform Inhibitors for Male Contraception. J Med Chem 2018; 61:1800-1820. [PMID: 29291372 PMCID: PMC5846083 DOI: 10.1021/acs.jmedchem.7b00925] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
![]()
Na,K-ATPase α4 is a testis-specific
plasma membrane Na+ and K+ transporter expressed
in sperm flagellum.
Deletion of Na,K-ATPase α4 in male mice results in complete
infertility, making it an attractive target for male contraception.
Na,K-ATPase α4 is characterized by a high affinity for the cardiac
glycoside ouabain. With the goal of discovering selective inhibitors
of the Na,K-ATPase α4 and of sperm function, ouabain derivatives
were modified at the glycone (C3) and the lactone (C17) domains. Ouabagenin
analogue 25, carrying a benzyltriazole moiety at C17,
is a picomolar inhibitor of Na,K-ATPase α4, with an outstanding
α4 isoform selectivity profile. Moreover, compound 25 decreased sperm motility in vitro and in vivo and affected sperm
membrane potential, intracellular Ca2+, pH, and hypermotility.
These results proved that the new ouabagenin triazole analogue is
an effective and selective inhibitor of Na,K-ATPase α4 and sperm
function.
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Affiliation(s)
- Shameem Sultana Syeda
- Department of Medicinal Chemistry and Institute for Therapeutics Discovery and Development, College of Pharmacy , University of Minnesota , Minneapolis , Minnesota 55414 , United States
| | - Gladis Sánchez
- Department of Molecular and Integrative Physiology , University of Kansas Medical Center , Kansas City , Kansas 66160 , United States
| | - Kwon Ho Hong
- Department of Medicinal Chemistry and Institute for Therapeutics Discovery and Development, College of Pharmacy , University of Minnesota , Minneapolis , Minnesota 55414 , United States
| | - Jon E Hawkinson
- Department of Medicinal Chemistry and Institute for Therapeutics Discovery and Development, College of Pharmacy , University of Minnesota , Minneapolis , Minnesota 55414 , United States
| | - Gunda I Georg
- Department of Medicinal Chemistry and Institute for Therapeutics Discovery and Development, College of Pharmacy , University of Minnesota , Minneapolis , Minnesota 55414 , United States
| | - Gustavo Blanco
- Department of Molecular and Integrative Physiology , University of Kansas Medical Center , Kansas City , Kansas 66160 , United States
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Asuaje A, Martín P, Enrique N, Zegarra LAD, Smaldini P, Docena G, Milesi V. Diphenhydramine inhibits voltage-gated proton channels (Hv1) and induces acidification in leukemic Jurkat T cells- New insights into the pro-apoptotic effects of antihistaminic drugs. Channels (Austin) 2018; 12:58-64. [PMID: 28514187 PMCID: PMC5972794 DOI: 10.1080/19336950.2017.1331799] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 05/09/2017] [Accepted: 05/10/2017] [Indexed: 12/22/2022] Open
Abstract
An established characteristic of neoplastic cells is their metabolic reprogramming, known as the Warburg effect, with greater reliance on energetically less efficient pathways (such as glycolysis and pentose phosphate shunt) compared with oxidative phosphorylation. This results in an overproduction of acidic species that must be extruded to maintain intracellular homeostasis. We recently described that blocking the proton currents in leukemic cells mediated by Hv1 ion channels triggers a marked intracellular acidification and apoptosis induction. Moreover, histamine H1-receptor antagonists were found to induce apoptosis in tumoral cells but the mechanism is still unclear. By using Jurkat T cells, we now show how diphenhydramine inhibits Hv1 mediated currents, inducing a drop in intracellular pH and cellular viability. This provides evidence of a new target structure responsible of the known pro-apoptotic action of antihistaminic drugs.
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Affiliation(s)
- Agustín Asuaje
- Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP, CONICET—Universidad Nacional de la Plata), Fac. de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Pedro Martín
- Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP, CONICET—Universidad Nacional de la Plata), Fac. de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Nicolás Enrique
- Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP, CONICET—Universidad Nacional de la Plata), Fac. de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Leandro Agustín Díaz Zegarra
- Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP, CONICET—Universidad Nacional de la Plata), Fac. de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Paola Smaldini
- Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP, CONICET—Universidad Nacional de la Plata), Fac. de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Guillermo Docena
- Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP, CONICET—Universidad Nacional de la Plata), Fac. de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Verónica Milesi
- Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP, CONICET—Universidad Nacional de la Plata), Fac. de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina
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8
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Asuaje A, Smaldini P, Martín P, Enrique N, Orlowski A, Aiello EA, Gonzalez León C, Docena G, Milesi V. The inhibition of voltage-gated H + channel (HVCN1) induces acidification of leukemic Jurkat T cells promoting cell death by apoptosis. Pflugers Arch 2016; 469:251-261. [PMID: 28013412 DOI: 10.1007/s00424-016-1928-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 12/05/2016] [Accepted: 12/06/2016] [Indexed: 11/26/2022]
Abstract
Cellular energetic deregulation is widely known to produce an overproduction of acidic species in cancer cells. This acid overload must be counterbalanced with a high rate of H+ extrusion to maintain cell viability. In this sense, many H+ transporters have been reported to be crucial for cell survival and proposed as antineoplastic target. By the way, voltage-gated proton channels (Hv1) mediate highly selective H+ outward currents, capable to compensate acid burden in brief periods of time. This structure is canonically described acting as NADPH oxidase counterbalance in reactive oxygen species production. In this work, we show, for the first time in a oncohematologic cell line, that inhibition of Hv1 channels by Zn2+ and the more selective blocker 2-(6-chloro-1H-benzimidazol-2-yl)guanidine (ClGBI) progressively decreases intracellular pH in resting conditions. This acidification is evident minutes after blockade and progresses under prolonged exposure (2, 17, and 48 h), and we firstly demonstrate that this is followed by cell death through apoptosis (annexin V binding). Altogether, these results contribute strong evidence that this channel might be a new therapeutic target in cancer.
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Affiliation(s)
- Agustín Asuaje
- Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP, CONICET-Universidad Nacional de la Plata), Fac. de Ciencias Exactas, Universidad Nacional de La Plata, 47 y 115, 1900, La Plata, Argentina
| | - Paola Smaldini
- Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP, CONICET-Universidad Nacional de la Plata), Fac. de Ciencias Exactas, Universidad Nacional de La Plata, 47 y 115, 1900, La Plata, Argentina
| | - Pedro Martín
- Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP, CONICET-Universidad Nacional de la Plata), Fac. de Ciencias Exactas, Universidad Nacional de La Plata, 47 y 115, 1900, La Plata, Argentina.
| | - Nicolás Enrique
- Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP, CONICET-Universidad Nacional de la Plata), Fac. de Ciencias Exactas, Universidad Nacional de La Plata, 47 y 115, 1900, La Plata, Argentina
| | - Alejandro Orlowski
- Centro de Investigaciones Cardiovasculares (CIC, CONICET-Universidad Nacional de la Plata), Fac. de Ciencias Médicas, Universidad Nacional de La Plata, 60 y 120, 1900, La Plata, Argentina
| | - Ernesto A Aiello
- Centro de Investigaciones Cardiovasculares (CIC, CONICET-Universidad Nacional de la Plata), Fac. de Ciencias Médicas, Universidad Nacional de La Plata, 60 y 120, 1900, La Plata, Argentina
| | - Carlos Gonzalez León
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Chile, Pasaje Harrington 287, Playa Ancha, Valparaíso, Chile
| | - Guillermo Docena
- Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP, CONICET-Universidad Nacional de la Plata), Fac. de Ciencias Exactas, Universidad Nacional de La Plata, 47 y 115, 1900, La Plata, Argentina
| | - Verónica Milesi
- Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP, CONICET-Universidad Nacional de la Plata), Fac. de Ciencias Exactas, Universidad Nacional de La Plata, 47 y 115, 1900, La Plata, Argentina
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9
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Chueca E, Apostolova N, Esplugues JV, García-González MA, Lanas Á, Piazuelo E. Proton Pump Inhibitors Display Antitumor Effects in Barrett's Adenocarcinoma Cells. Front Pharmacol 2016; 7:452. [PMID: 27932981 PMCID: PMC5122752 DOI: 10.3389/fphar.2016.00452] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 11/11/2016] [Indexed: 12/14/2022] Open
Abstract
Recent evidence has reported that proton pump inhibitors (PPIs) can exert antineoplastic effects through the disruption of pH homeostasis by inhibiting vacuolar ATPase (H+-VATPase), a proton pump overexpressed in several tumor cells, but this aspect has not been deeply investigated in EAC yet. In the present study, the expression of H+-VATPase was assessed through the metaplasia-dysplasia-adenocarcinoma sequence in Barrett's esophagus (BE) and the antineoplastic effects of PPIs and cellular mechanisms involved were evaluated in vitro. H+-VATPase expression was assessed by immunohistochemistry in paraffined-embedded samples or by immunofluorescence in cultured BE and EAC cell lines. Cells were treated with different concentrations of PPIs and parameters of citotoxicity, oxidative stress, and autophagy were evaluated. H+-VATPase expression was found in all biopsies and cell lines evaluated, showing differences in the location of the pump between the cell lines. Esomeprazole inhibited proliferation and cell invasion and induced apoptosis of EAC cells. Production of reactive oxygen species (ROS) seemed to be involved in the cytotoxic effects observed since the addition of N-acetylcysteine significantly reduced esomeprazole-induced apoptosis in EAC cells. Esomeprazole also reduced intracellular pH of tumor cells, whereas only disturbed the mitochondrial membrane potential in OE33 cells. Esomeprazole induced autophagy in both EAC cells, but also triggered a blockade in autophagic flux in the metastatic cell line. These data provide in vitro evidence supporting the potential use of PPIs as novel antineoplastic drugs for EAC and also shed some light on the mechanisms that trigger PPIs cytotoxic effects, which differ upon the cell line evaluated.
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Affiliation(s)
- Eduardo Chueca
- CIBERehdMadrid, Spain; Instituto de Investigación Sanitaria AragónZaragoza, Spain
| | - Nadezda Apostolova
- CIBERehdMadrid, Spain; Department of Pharmacology, University of ValenciaValencia, Spain
| | - Juan V Esplugues
- CIBERehdMadrid, Spain; Department of Pharmacology, University of ValenciaValencia, Spain
| | - María A García-González
- CIBERehdMadrid, Spain; Instituto de Investigación Sanitaria AragónZaragoza, Spain; CIBA, Instituto Aragonés de Ciencias de la SaludZaragoza, Spain
| | - Ángel Lanas
- CIBERehdMadrid, Spain; Instituto de Investigación Sanitaria AragónZaragoza, Spain; Department of Medicine, Psychiatry and Dermatology, University of ZaragozaZaragoza, Spain
| | - Elena Piazuelo
- CIBERehdMadrid, Spain; Instituto de Investigación Sanitaria AragónZaragoza, Spain; CIBA, Instituto Aragonés de Ciencias de la SaludZaragoza, Spain
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10
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Meo-Evoli N, Almacellas E, Massucci FA, Gentilella A, Ambrosio S, Kozma SC, Thomas G, Tauler A. V-ATPase: a master effector of E2F1-mediated lysosomal trafficking, mTORC1 activation and autophagy. Oncotarget 2016; 6:28057-70. [PMID: 26356814 PMCID: PMC4695044 DOI: 10.18632/oncotarget.4812] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 07/30/2015] [Indexed: 11/26/2022] Open
Abstract
In addition to being a master regulator of cell cycle progression, E2F1 regulates other associated biological processes, including growth and malignancy. Here, we uncover a regulatory network linking E2F1 to lysosomal trafficking and mTORC1 signaling that involves v-ATPase regulation. By immunofluorescence and time-lapse microscopy we found that E2F1 induces the movement of lysosomes to the cell periphery, and that this process is essential for E2F1-induced mTORC1 activation and repression of autophagy. Gain- and loss-of-function experiments reveal that E2F1 regulates v-ATPase activity and inhibition of v-ATPase activity repressed E2F1-induced lysosomal trafficking and mTORC1 activation. Immunoprecipitation experiments demonstrate that E2F1 induces the recruitment of v-ATPase to lysosomal RagB GTPase, suggesting that E2F1 regulates v-ATPase activity by enhancing the association of V0 and V1 v-ATPase complex. Analysis of v-ATPase subunit expression identified B subunit of V0 complex, ATP6V0B, as a transcriptional target of E2F1. Importantly, ATP6V0B ectopic-expression increased v-ATPase and mTORC1 activity, consistent with ATP6V0B being responsible for mediating the effects of E2F1 on both responses. Our findings on lysosomal trafficking, mTORC1 activation and autophagy suppression suggest that pharmacological intervention at the level of v-ATPase may be an efficacious avenue for the treatment of metastatic processes in tumors overexpressing E2F1.
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Affiliation(s)
- Nathalie Meo-Evoli
- Departament de Bioquímica i Biologia Molecular, Facultat de Farmàcia, Universitat de Barcelona, 08028 Barcelona, Catalunya, Spain.,Laboratory of Cancer Metabolism, IDIBELL, Hospital Duran i Reynals, 08908 L'Hospitalet de Llobregat, Barcelona, Catalunya, Spain
| | - Eugènia Almacellas
- Departament de Bioquímica i Biologia Molecular, Facultat de Farmàcia, Universitat de Barcelona, 08028 Barcelona, Catalunya, Spain.,Laboratory of Cancer Metabolism, IDIBELL, Hospital Duran i Reynals, 08908 L'Hospitalet de Llobregat, Barcelona, Catalunya, Spain
| | | | - Antonio Gentilella
- Laboratory of Cancer Metabolism, IDIBELL, Hospital Duran i Reynals, 08908 L'Hospitalet de Llobregat, Barcelona, Catalunya, Spain
| | - Santiago Ambrosio
- Unitat de Bioquímica, Dep. Ciències Fisiològiques II, Facultat de Medicina, Campus Universitari de Bellvitge - IDIBELL, Universitat de Barcelona, 08908 L'Hospitalet de Llobregat, Barcelona, Catalunya, Spain
| | - Sara C Kozma
- Laboratory of Cancer Metabolism, IDIBELL, Hospital Duran i Reynals, 08908 L'Hospitalet de Llobregat, Barcelona, Catalunya, Spain.,Laboratory of Cancer Metabolism, Institut Català d'Oncologia, Hospital Duran i Reynals, 08908 L'Hospitalet de Llobregat, Barcelona, Catalunya, Spain.,Division of Hematology and Oncology, Department of Internal Medicine, College of Medicine, University of Cincinnati, Cincinnati, Ohio 45267, USA
| | - George Thomas
- Laboratory of Cancer Metabolism, IDIBELL, Hospital Duran i Reynals, 08908 L'Hospitalet de Llobregat, Barcelona, Catalunya, Spain.,Unitat de Bioquímica, Dep. Ciències Fisiològiques II, Facultat de Medicina, Campus Universitari de Bellvitge - IDIBELL, Universitat de Barcelona, 08908 L'Hospitalet de Llobregat, Barcelona, Catalunya, Spain.,Laboratory of Cancer Metabolism, Institut Català d'Oncologia, Hospital Duran i Reynals, 08908 L'Hospitalet de Llobregat, Barcelona, Catalunya, Spain.,Division of Hematology and Oncology, Department of Internal Medicine, College of Medicine, University of Cincinnati, Cincinnati, Ohio 45267, USA
| | - Albert Tauler
- Departament de Bioquímica i Biologia Molecular, Facultat de Farmàcia, Universitat de Barcelona, 08028 Barcelona, Catalunya, Spain.,Laboratory of Cancer Metabolism, IDIBELL, Hospital Duran i Reynals, 08908 L'Hospitalet de Llobregat, Barcelona, Catalunya, Spain
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11
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Hektoen HH, Ree AH, Redalen KR, Flatmark K. Sulfamate inhibitor S4 influences carbonic anhydrase IX ectodomain shedding in colorectal carcinoma cells. J Enzyme Inhib Med Chem 2015; 31:779-86. [PMID: 26244271 DOI: 10.3109/14756366.2015.1069286] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Carbonic anhydrase IX (CAIX) is a pivotal pH regulator under hypoxia, which by its tumor-specific expression represents an attractive target for cancer therapy. Here, we report on effects of the sulfamate CAIX inhibitor S4 (4-(3'-(3″,5″-dimethylphenyl)ureido)phenyl sulfamate) in colorectal carcinoma cell lines. S4 was administered under experimental hypoxia or normoxia to HT29, KM20L2 and HCT116 cells. Effects on survival, proliferation, pH, lactate extrusion and CAIX protein expression were evaluated. S4 treatment resulted in attenuated hypoxia-induced extracellular acidification and reduced clonogenic survival under hypoxia in HT29 cells. The pH effects were present only in a [Formula: see text]-free buffer system and were accompanied by decreased lactate extrusion. The main finding of this work was that S4 treatment caused alterations in CAIX ectodomain shedding. This merits further investigation to understand how sulfamates influence CAIX activity and how such drugs may be of use in cancer treatment.
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Affiliation(s)
- Helga Helseth Hektoen
- a Institute of Clinical Medicine, University of Oslo , Oslo , Norway .,b Department of Tumor Biology , Oslo University Hospital , Oslo , Norway .,c Department of Oncology , Akershus University Hospital , Lørenskog , Norway , and
| | - Anne Hansen Ree
- a Institute of Clinical Medicine, University of Oslo , Oslo , Norway .,c Department of Oncology , Akershus University Hospital , Lørenskog , Norway , and
| | - Kathrine Røe Redalen
- c Department of Oncology , Akershus University Hospital , Lørenskog , Norway , and
| | - Kjersti Flatmark
- a Institute of Clinical Medicine, University of Oslo , Oslo , Norway .,b Department of Tumor Biology , Oslo University Hospital , Oslo , Norway .,d Department of Gastroenterological Surgery , Oslo University Hospital , Oslo , Norway
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12
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El-Malah SS, Yang Z, Hu M, Li Q, Pan Z, Jiao X. Vibrio parahaemolyticus strengthens their virulence through modulation of cellular reactive oxygen species in vitro. Front Cell Infect Microbiol 2014; 4:168. [PMID: 25566508 PMCID: PMC4269196 DOI: 10.3389/fcimb.2014.00168] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 11/14/2014] [Indexed: 02/05/2023] Open
Abstract
Vibrio parahaemolyticus (Vp) is one of the emergent food-borne pathogens that are commensally associated with various shellfish species throughout the world. It is strictly environmental and many strains are pathogenic to humans. The virulent strains cause distinct diseases, including wound infections, septicemia, and most commonly, acute gastroenteritis, which is acquired through the consumption of raw or undercooked seafood, especially shellfish. Vp has two type three secretion systems (T3SSs), which triggering its cytotoxicity and enterotoxicity via their effectors. To better understand the pathogenesis of Vp, we established a cell infection model in vitro using a non-phagocytic cell line. Caco-2 cells were infected with different strains of Vp (pandemic and non-pandemic strains) and several parameters of cytotoxicity were measured together with adhesion and invasion indices, which reflect the pathogen's virulence. Our results show that Vp adheres to cell monolayers and can invade non-phagocytic cells. It also survives and persists in non-phagocytic cells by modulating reactive oxygen species (ROS), allowing its replication, and resulting in complete cellular destruction. We conclude that the pathogenicity of Vp is based on its capacities for adhesion and invasion. Surprisingly's; enhanced of ROS resistance period could promote the survival of Vp inside the intestinal tract, facilitating tissue infection by repressing the host's oxidative stress response.
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Affiliation(s)
- Shimaa S El-Malah
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University Yangzhou, China
| | - Zhenquan Yang
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University Yangzhou, China ; College of Food Science and Engineering, Yangzhou University Yangzhou, China
| | - Maozhi Hu
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University Yangzhou, China ; Testing Center, Yangzhou University Yangzhou, China
| | - Qiuchun Li
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University Yangzhou, China
| | - Zhiming Pan
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University Yangzhou, China
| | - Xinan Jiao
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-Innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University Yangzhou, China
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13
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Le V, Esposito D, Grace MH, Ha D, Pham A, Bortolazzo A, Bevens Z, Kim J, Okuda R, Komarnytsky S, Lila MA, White JB. Cytotoxic effects of ellagitannins isolated from walnuts in human cancer cells. Nutr Cancer 2014; 66:1304-14. [PMID: 25264855 DOI: 10.1080/01635581.2014.956246] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Walnuts contain many bioactive components that may slow cancer growth. A previous report showed that a diet supplemented with walnuts decreased the tumor size formed by MDA-MB-231 human cancer cells injected into nude mice. However, the mechanism of action was never determined. We characterized the effects of a methanol extract prepared from walnuts on human MDA-MB-231, MCF7, and HeLa cells. The extract was cytotoxic to all cancer cells. We identified compounds from the methanol extract that induced this cytotoxicity. The predominant compounds were Tellimagrandin I and Tellimagrandin II, members of the ellagitannin family. We also show a walnut extract decreases the intracellular pH, depolarizes the mitochondrial membrane with release of cytochrome c and phosphatidylserine flipping. The antimitogenic effects of walnut extract were associated with a twofold reduction of mitochondria respiration. These results suggest impairment of mitochondrial function and apoptosis as relevant mechanism of anticancer effects of the walnut extract.
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Affiliation(s)
- Vy Le
- a Department of Biological Sciences , San José State University , San Jose , California , USA
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14
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Hu M, Yang Y, Meng C, Pan Z, Jiao X. Responses of macrophages against Salmonella infection compared with phagocytosis. In Vitro Cell Dev Biol Anim 2013; 49:778-84. [PMID: 23949781 DOI: 10.1007/s11626-013-9672-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 07/18/2013] [Indexed: 02/07/2023]
Abstract
To explore the responses of host cell after infection with live Salmonella compared with phagocytosis to dead bacteria, the responses of mouse macrophage after infection with Salmonella enteritidis C50041 and the fixed C50041 (C50041-d) were analyzed. Results indicated that the cytotoxicity induced by C50041 was stronger than C50041-d. Similar changing trends of mitochondrial membrane potential, intracellular concentration of calcium ions, reactive oxygen species and nitric oxide were found between C50041 and C50041-d infection. But the cell responses against C50041 were earlier and stronger than C50041-d. LC3 expression of macrophage induced by C50041 was lower than C50041-d. C50041 significantly inhibited the production of tumor necrosis factor and interleukin (IL)-6. Whereas intracellular caspase-1 activation and IL-1β release induced by C50041 were stronger than C50041-d, caspase-1 activation and IL-1β release are the innate defense responses of macrophage. Therefore, it will be beneficial to explore the use of this pathway in the control of Salmonella infection.
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Affiliation(s)
- Maozhi Hu
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, 225009, People's Republic of China
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15
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Ritt M, Guan JL, Sivaramakrishnan S. Visualizing and manipulating focal adhesion kinase regulation in live cells. J Biol Chem 2013; 288:8875-86. [PMID: 23393139 DOI: 10.1074/jbc.m112.421164] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Focal Adhesion Kinase (FAK) is essential for cell migration and plays an important role in tumor metastasis. However, the complex intermolecular and intramolecular interactions that regulate FAK activity at the focal adhesion remain unresolved. We have engineered a toolbox of FRET sensors that retain all of the individual FAK domains but modulate a key intramolecular regulatory interaction between the band 4.1/ezrin/radixin/moesin (FERM) and kinase domains of FAK. We demonstrate systematic control and quantitative measurement of the FERM-kinase interaction at focal adhesions, which in turn allows us to control cell migration. Using these sensors, we find that Tyr-397 phosphorylation, rather than kinase activity of FAK, is the key determinant of cell migration. Our sensors directly demonstrate, for the first time, a pH-dependent change in a protein-protein interaction at a macromolecular structure in live cells. The FERM-kinase interaction at focal adhesions is enhanced at acidic pH, with a concomitant decrease in Tyr-397 phosphorylation, providing a potential mechanism for enhanced migration of cancer cells.
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Affiliation(s)
- Michael Ritt
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
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16
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Jancic CC, Cabrini M, Gabelloni ML, Rodríguez Rodrigues C, Salamone G, Trevani AS, Geffner J. Low extracellular pH stimulates the production of IL-1β by human monocytes. Cytokine 2011; 57:258-68. [PMID: 22154780 DOI: 10.1016/j.cyto.2011.11.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Revised: 10/06/2011] [Accepted: 11/17/2011] [Indexed: 10/14/2022]
Abstract
The development of acidic environments is a hallmark of inflammatory processes of different etiology. We have previously shown that transient exposure to acidic conditions, similar to those encountered in vivo, induces the activation of neutrophils and the phenotypic maturation of dendritic cells. We here report that extracellular acidosis (pH 6.5) selectively stimulates the production and the secretion of IL-1β by human monocytes without affecting the production of TNF-α, IL-6 and the expression of CD40, CD80, CD86, and HLA-DR. Stimulation of IL-1β production by pH 6.5-treated monocytes was shown to be dependent on caspase-1 activity, and it was also observed using peripheral blood mononuclear cells instead of isolated monocytes. Contrasting with the results in monocytes, we found that pH 6.5 did not stimulate any production of IL-1β by macrophages. Changes in intracellular pH seem to be involved in the stimulation of IL-1β production. In fact, monocytes cultured at pH 6.5 undergo a fall in the values of intracellular pH while the inhibitor of the Na+/H+ exchanger, 5-(N-ethyl-N-isopropyl)amiloride induced both, a decrease in the values of intracellular pH and the stimulation of IL-1β production. Real time quantitative PCR assays indicated that monocytes cultured either at pH 6.5 or in the presence of 5-(N-ethyl-N-isopropyl)amiloride expressed higher levels of pro-IL-1β mRNA suggesting that low values of intracellular pH enhance the production of IL-1β, at least in part, by stimulating the synthesis of its precursor.
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Affiliation(s)
- Carolina Cristina Jancic
- Instituto de Investigaciones Hematológicas (IIHEMA), Academia Nacional de Medicina, Buenos Aires, Argentina.
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17
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Konovalova SA, Zubatkina IS, Savina MV, Nikiforov AA. Intracellular pH in hepatocytes of the river lamprey Lampetra fluviatilis L. at the period of pre-spawning migration. J EVOL BIOCHEM PHYS+ 2011. [DOI: 10.1134/s0022093011040116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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18
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Roberts ES, Wong VA, McManus BE, Marshall MW, Lancianese S, Dorman DC. Changes in intracellular pH play a secondary role in hydrogen sulfide-induced nasal cytotoxicity. Inhal Toxicol 2007; 18:159-67. [PMID: 16399658 DOI: 10.1080/08958370500434156] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Hydrogen sulfide (H(2)S) is a naturally occurring gas that is also associated with several industries. The potential for widespread human inhalation exposure to this toxic gas is recognized as a public health concern. The nasal epithelium is particularly susceptible to H(2)S-induced pathology. Cytochrome oxidase inhibition is postulated as one mechanism of H(2)S toxicity. Another mechanism by which the weak acid H(2)S could cause nasal injury is intracellular acidification and cytotoxicity. To further understand the mechanism by which H(2)S damages the nasal epithelium, nasal respiratory and olfactory epithelial cell isolates and explants from naive rats were loaded with the pH-sensitive intracellular chromophore SNARF-1 and exposed to air or 10, 80, 200, or 400 ppm H(2)S for 90 min. Intracellular pH was measured using flow cytometry or confocal microscopy. Cell lysates were used to quantify total protein and cytochrome oxidase activity. A modest but statistically significant decrease in intracellular pH occurred following exposure of respiratory and olfactory epithelium to 400 ppm H(2)S. Decreased cytochrome oxidase activity was observed following exposure to >10 ppm H(2)S in both respiratory and olfactory epithelia. None of the treatments resulted in cytotoxicity. The intracellular acidification of nasal epithelial cells by high-dose H(2)S exposure and the inhibition of cytochrome oxidase at much lower H(2)S concentrations suggest that changes in intracellular pH play a secondary role in H(2)S-induced nasal injury.
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Affiliation(s)
- E S Roberts
- CIIT Centers for Health Research, Research Triangle Park, North Carolina 27709-2137, USA.
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Ono K, Wang X, Han J. Resistance to tumor necrosis factor-induced cell death mediated by PMCA4 deficiency. Mol Cell Biol 2001; 21:8276-88. [PMID: 11713265 PMCID: PMC99993 DOI: 10.1128/mcb.21.24.8276-8288.2001] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2001] [Accepted: 09/12/2001] [Indexed: 11/20/2022] Open
Abstract
We used retrovirus insertion-mediated random mutagenesis to generate tumor necrosis factor (TNF)-resistant lines from L929 cells. Using this approach, we discovered that the plasma membrane calcium ATPase 4 (PMCA4) is required for TNF-induced cell death in L929 cells. Under basal conditions, PMCA4-deficient (PMCA(mut)) cells have a normal phenotype. However, stimulation with TNF induces an abnormal increase in the intracellular calcium concentration ([Ca(2+)](i)). The substantially elevated [Ca(2+)](i) caused resistance to TNF-induced cell death. We found that an increase in the total volume of acidic compartments (VAC), mainly constituted by lysosomes, is a common event in cell death caused by a variety of agonists. The increased [Ca(2+)](i) in PMCA(mut) cells promoted lysosome exocytosis, which, at least in part, accounted for the inhibition of TNF-induced increase in VAC and cell death. Promoting lysosome exocytosis by calcium inhibited TNF-induced cell death in wild-type L929 cells, while inhibition of lysosome exocytosis or increase of VAC by sucrose restored the sensitivity of PMCA(mut) cells to TNF-induced cell death. Thus, increase of the volume of acidic compartment is a part of the cell death process, and the antideath effect of calcium is mediated, at least in part, by inhibition of the TNF-induced increase in VAC.
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Affiliation(s)
- K Ono
- Department of Immunology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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