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Mejia EM, Hizon NA, Dueck CE, Lidder R, Daigle J, Wonitowy Q, Medina NG, Mohammed UP, Cox GW, Safronetz D, Hagan M, Strong J, Nichani A, Mulvey MR, Mangat CS. Detection of mpox virus in wastewater provides forewarning of clinical cases in Canadian cities. Sci Total Environ 2024; 933:173108. [PMID: 38729376 DOI: 10.1016/j.scitotenv.2024.173108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 05/07/2024] [Accepted: 05/07/2024] [Indexed: 05/12/2024]
Abstract
Wastewater-based surveillance (WBS) has shown to be an effective tool in monitoring the spread of SARS-CoV-2 and has helped guide public health actions. Consequently, WBS has expanded to now include the monitoring of mpox virus (MPXV) to contribute to its mitigation efforts. In this study, we demonstrate a unique sample processing and a molecular diagnostic strategy for MPXV detection that can inform on the epidemiological situation of mpox outbreaks through WBS. We conducted WBS for MPXV in 22 Canadian wastewater treatment plants (WWTPs) for 14 weeks. Three MPXV qPCR assays were assessed in this study for the detection of MPXV which include the G2R assays (G2R_WA and G2R_G) developed by the Centers for Disease Control and Prevention (CDC) in 2010, and an in-house-developed assay that we have termed G2R_NML. The G2R_NML assay was designed using reference genomes from the 2022 MPXV outbreak and provides a larger qPCR amplicon size to facilitate Sanger sequencing. Results show that all three assays have similar limits of detection and are able to detect the presence of MPXV in wastewater. The G2R_NML assay produced a significantly greater number of Sanger sequence-confirmed MPXV results compared to the CDC G2R assays. Detection of MPXV was possible where provincial surveillance indicated overall low caseloads, and in some sites forewarning of up to several weeks was observed. Overall, this study proposes that WBS of MPXV provides additional information to help fill knowledge gaps in clinical case-surveillance and is potentially an essential component to the management of mpox.
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Affiliation(s)
- Edgard M Mejia
- Wastewater Surveillance Unit, Bacterial Pathogens, AMR, and Wastewater, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada.
| | - Nikho A Hizon
- Wastewater Surveillance Unit, Bacterial Pathogens, AMR, and Wastewater, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Codey E Dueck
- Wastewater Surveillance Unit, Bacterial Pathogens, AMR, and Wastewater, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Ravinder Lidder
- Wastewater Surveillance Unit, Bacterial Pathogens, AMR, and Wastewater, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Jade Daigle
- Wastewater Surveillance Unit, Bacterial Pathogens, AMR, and Wastewater, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Quinn Wonitowy
- Wastewater Surveillance Unit, Bacterial Pathogens, AMR, and Wastewater, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Nestor G Medina
- Wastewater Surveillance Unit, Bacterial Pathogens, AMR, and Wastewater, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Umar P Mohammed
- Wastewater Surveillance Unit, Bacterial Pathogens, AMR, and Wastewater, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Graham W Cox
- Wastewater Surveillance Unit, Bacterial Pathogens, AMR, and Wastewater, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - David Safronetz
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada; Department of Medical Microbiology and Infectious Diseases, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Mable Hagan
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Jim Strong
- Special Pathogens Program, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada; Department of Medical Microbiology and Infectious Diseases, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Anil Nichani
- Wastewater Surveillance Unit, Bacterial Pathogens, AMR, and Wastewater, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Michael R Mulvey
- Wastewater Surveillance Unit, Bacterial Pathogens, AMR, and Wastewater, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada; Antimicrobial Resistance Nosocomial Infections, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada; Department of Medical Microbiology and Infectious Diseases, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Chand S Mangat
- Wastewater Surveillance Unit, Bacterial Pathogens, AMR, and Wastewater, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada; Antimicrobial Resistance Nosocomial Infections, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada; Department of Medical Microbiology and Infectious Diseases, Max Rady College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
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Sachdeva H, Shahin R, Ota S, Isabel S, Mangat CS, Stuart R, Padhi S, Chris A, Mishra S, Tan DHS, Braukmann TW, Eshaghi A, Mejia EM, Hizon NA, Finkelstein M. Preparing for Mpox Resurgence: Surveillance Lessons From Outbreaks in Toronto, Canada. J Infect Dis 2024; 229:S305-S312. [PMID: 38035826 DOI: 10.1093/infdis/jiad533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 11/16/2023] [Accepted: 11/27/2023] [Indexed: 12/02/2023] Open
Abstract
BACKGROUND With many global jurisdictions, Toronto, Canada, experienced an mpox outbreak in spring/summer 2022. Cases declined following implementation of a large vaccination campaign. A surge in early 2023 led to speculation that asymptomatic and/or undetected local transmission was occurring in the city. METHODS Mpox cases and positive laboratory results are reported to Toronto Public Health. Epidemic curves and descriptive risk factor summaries for the 2022 and 2023 outbreaks were generated. First- and second-dose vaccination was monitored. Mpox virus wastewater surveillance and whole genome sequencing were conducted to generate hypotheses about the source of the 2023 resurgence. RESULTS An overall 515 cases were reported in spring/summer 2022 and 17 in the 2022-2023 resurgence. Wastewater data correlated with the timing of cases. Whole genome sequencing showed that 2022-2023 cases were distinct from 2022 cases and closer to sequences from another country, suggesting a new importation as a source. At the start of the resurgence, approximately 16% of first-dose vaccine recipients had completed their second dose. CONCLUSIONS This investigation demonstrates the importance of ongoing surveillance and preparedness for mpox outbreaks. Undetected local transmission was not a likely source of the 2022-2023 resurgence. Ongoing preexposure vaccine promotion remains important to mitigate disease burden.
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Affiliation(s)
- Herveen Sachdeva
- Toronto Public Health
- Dalla Lana School of Public Health, University of Toronto
| | - Rita Shahin
- Toronto Public Health
- Dalla Lana School of Public Health, University of Toronto
| | | | - Sandra Isabel
- Public Health Ontario, Toronto
- Axe Maladies infectieuses et immunitaires, Centre de recherche du CHU de Québec-Université Laval
| | - Chand S Mangat
- Wastewater Surveillance Unit, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba
| | | | - Shovita Padhi
- Toronto Public Health
- Dalla Lana School of Public Health, University of Toronto
| | - Allison Chris
- Toronto Public Health
- Dalla Lana School of Public Health, University of Toronto
| | - Sharmistha Mishra
- MAP Centre for Urban Health Solutions, Li Ka Shing Knowledge Institute, Unity Health Toronto
- Department of Medicine, Temerty Faculty of Medicine
- Institute of Health Policy, Management and Evaluation and Institute of Medical Science, University of Toronto
- Institute for Clinical Evaluative Sciences (ICES)
- Division of Infectious Diseases, St Michael's Hospital, Toronto, Ontario, Canada
| | - Darrell H S Tan
- MAP Centre for Urban Health Solutions, Li Ka Shing Knowledge Institute, Unity Health Toronto
- Department of Medicine, Temerty Faculty of Medicine
- Institute of Health Policy, Management and Evaluation and Institute of Medical Science, University of Toronto
- Division of Infectious Diseases, St Michael's Hospital, Toronto, Ontario, Canada
| | | | | | - Edgard M Mejia
- Wastewater Surveillance Unit, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba
| | - Nikho A Hizon
- Wastewater Surveillance Unit, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba
| | - Michael Finkelstein
- Toronto Public Health
- Dalla Lana School of Public Health, University of Toronto
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Asadi M, Hamilton D, Shomachuk C, Oloye FF, De Lange C, Pu X, Osunla CA, Cantin J, El-Baroudy S, Mejia EM, Gregorchuk B, Becker MG, Mangat C, Brinkmann M, Jones PD, Giesy JP, McPhedran KN. Assessment of rapid wastewater surveillance for determination of communicable disease spread in municipalities. Sci Total Environ 2023; 901:166541. [PMID: 37625717 DOI: 10.1016/j.scitotenv.2023.166541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 08/02/2023] [Accepted: 08/22/2023] [Indexed: 08/27/2023]
Abstract
Wastewater surveillance (WS) helps to improve the understanding of the spread of communicable diseases in communities. WS can assist public health decision-makers in the design and implementation of timely mitigation measures. There is an increased need to use reliable, cost-effective, simple, and rapid WS systems, given traditional analytical (or 'gold-standard') programs are instrument/time-intensive, and dependent on highly skilled personnel. This study investigated the application of the portable GeneXpert platform for WS of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza A virus (IAV), influenza B virus (IBV), and respiratory syncytial virus (RSV). The GeneXpert system with the Xpert Xpress-SARS-CoV-2/Flu/RSV test kit uses reverse transcription-quantitative polymerase chain reaction (RT-qPCR) to analyze wastewater samples. From September 2022 through January 2023, wastewater samples were collected from the influents of municipal wastewater treatment plants (MWTPs) of Saskatoon, Prince Albert, and North Battleford in the province of Saskatchewan, Canada. Both raw and concentrated wastewater samples were subjected to the GeneXpert analysis. Results showed that the Saskatoon wastewater viral loads were significantly correlated to Saskatchewan's influenza and COVID-19 clinical cases, with a lead time of 10 days for IAV and a lag time of 4 days for SARS-CoV-2. Additionally, the GeneXpert analysis of the three cities' wastewater samples showed that the raw WS could capture the dynamics of SARS-CoV-2 and IAV due to their correlation with concentrated WS. Interestingly, IBV loads were not detected in any wastewater samples, while the Saskatoon and Prince Albert wastewater samples collected following the 2023 holiday season (end of December and beginning of January) were positive for RSV. This study indicates that the GeneXpert has excellent potential for use in the development of an early warning system for transmissible disease in municipalities and limited-resource communities while simultaneously providing stakeholders with an efficient WS methodology.
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Affiliation(s)
- Mohsen Asadi
- Department of Civil, Geological and Environmental Engineering, College of Engineering, University of Saskatchewan, Saskatoon, SK, Canada; Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Daniel Hamilton
- Department of Civil, Geological and Environmental Engineering, College of Engineering, University of Saskatchewan, Saskatoon, SK, Canada
| | - Corwyn Shomachuk
- Department of Civil, Geological and Environmental Engineering, College of Engineering, University of Saskatchewan, Saskatoon, SK, Canada
| | - Femi F Oloye
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Chantel De Lange
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Xia Pu
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Charles A Osunla
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Jenna Cantin
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Seba El-Baroudy
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada
| | - Edgard M Mejia
- JC Wilt Infectious Diseases Research Centre, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Branden Gregorchuk
- JC Wilt Infectious Diseases Research Centre, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Michael G Becker
- JC Wilt Infectious Diseases Research Centre, National Microbiology Laboratory, Public Health Agency of Canada, Winnipeg, Manitoba, Canada
| | - Chand Mangat
- Wastewater Surveillance Unit, On-Health Division, National Microbiology Laboratory - Winnipeg, Public Health Agency of Canada, Canada
| | - Markus Brinkmann
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada; Global Institute for Water Security, University of Saskatchewan, Saskatoon, SK, Canada; School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK, Canada
| | - Paul D Jones
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada; School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK, Canada
| | - John P Giesy
- Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada; Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, SK, Canada; Department of Environmental Sciences, Baylor University, Waco, TX, USA; Department of Integrative Biology and Center for Integrative Toxicology, Michigan State University, East Lansing, MI, USA
| | - Kerry N McPhedran
- Department of Civil, Geological and Environmental Engineering, College of Engineering, University of Saskatchewan, Saskatoon, SK, Canada; Global Institute for Water Security, University of Saskatchewan, Saskatoon, SK, Canada.
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Joung MJ, Mangat CS, Mejia EM, Nagasawa A, Nichani A, Perez-Iratxeta C, Peterson SW, Champredon D. Coupling wastewater-based epidemiological surveillance and modelling of SARS-COV-2/COVID-19: Practical applications at the Public Health Agency of Canada. Can Commun Dis Rep 2023; 49:166-174. [PMID: 38404704 PMCID: PMC10890812 DOI: 10.14745/ccdr.v49i05a01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Wastewater-based surveillance (WBS) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) offers a complementary tool for clinical surveillance to detect and monitor coronavirus disease 2019 (COVID-19). Since both symptomatic and asymptomatic individuals infected with SARS-CoV-2 can shed the virus through the fecal route, WBS has the potential to measure community prevalence of COVID-19 without restrictions from healthcare-seeking behaviours and clinical testing capacity. During the Omicron wave, the limited capacity of clinical testing to identify COVID-19 cases in many jurisdictions highlighted the utility of WBS to estimate disease prevalence and inform public health strategies; however, there is a plethora of in-sewage, environmental and laboratory factors that can influence WBS outcomes. The implementation of WBS, therefore, requires a comprehensive framework to outline a pipeline that accounts for these complex and nuanced factors. This article reviews the framework of the national WBS conducted at the Public Health Agency of Canada to present WBS methods used in Canada to track and monitor SARS-CoV-2. In particular, we focus on five Canadian cities-Vancouver, Edmonton, Toronto, Montréal and Halifax-whose wastewater signals are analyzed by a mathematical model to provide case forecasts and reproduction number estimates. The goal of this work is to share our insights on approaches to implement WBS. Importantly, the national WBS system has implications beyond COVID-19, as a similar framework can be applied to monitor other infectious disease pathogens or antimicrobial resistance in the community.
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Affiliation(s)
- Meong Jin Joung
- National Microbiology Laboratory, Public Health Risk Sciences Division, Public Health Agency of Canada, Guelph, ON
- Dalla Lana School of Public Health, University of Toronto. Toronto, ON
| | - Chand S Mangat
- National Microbiology Laboratory, Wastewater Surveillance Unit, Public Health Agency of Canada, Winnipeg, MB
| | - Edgard M Mejia
- National Microbiology Laboratory, Wastewater Surveillance Unit, Public Health Agency of Canada, Winnipeg, MB
| | - Audra Nagasawa
- Statistics Canada, Centre for Direct Health Measures, Ottawa, ON
| | - Anil Nichani
- National Microbiology Laboratory, Public Health Agency of Canada, Guelph, ON
| | | | - Shelley W Peterson
- National Microbiology Laboratory, Wastewater Surveillance Unit, Public Health Agency of Canada, Winnipeg, MB
| | - David Champredon
- National Microbiology Laboratory, Public Health Risk Sciences Division, Public Health Agency of Canada, Guelph, ON
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Zegallai HM, Abu-El-Rub E, Mejia EM, Sparagna GC, Cole LK, Marshall AJ, Hatch GM. Tafazzin deficiency attenuates anti-cluster of differentiation 40 and interleukin-4 activation of mouse B lymphocytes. Cell Tissue Res 2022; 390:429-439. [PMID: 36129532 DOI: 10.1007/s00441-022-03692-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 09/14/2022] [Indexed: 12/14/2022]
Abstract
Barth syndrome (BTHS) is a rare X-linked genetic disease caused by mutations in TAFAZZIN. The tafazzin (Taz) protein is a cardiolipin remodeling enzyme required for maintaining mitochondrial function. Patients with BTHS exhibit impaired mitochondrial respiratory chain and metabolic function and are susceptible to serious infections. B lymphocytes (B cells) play a vital role in humoral immunity required to eradicate circulating antigens from pathogens. Intact mitochondrial respiration is required for proper B-cell function. We investigated whether Taz deficiency in mouse B cells altered their response to activation by anti-cluster of differentiation 40 (anti-CD40) + interleukin-4 (IL-4). B cells were isolated from 3-4-month-old wild type (WT) or tafazzin knockdown (TazKD) mice and were stimulated with anti-CD40 + IL-4 for 24 h and cellular bioenergetics, surface marker expression, proliferation, antibody production, and proteasome and immunoproteasome activities determined. TazKD B cells exhibited reduced mRNA expression of Taz, lowered levels of cardiolipin, and impairment in both oxidative phosphorylation and glycolysis compared to WT B cells. In addition, anti-CD40 + IL-4 stimulated TazKD B cells expressed lower levels of the immunogenic surface markers, cluster of differentiation 86 (CD86) and cluster of differentiation 69 (CD69), exhibited a lower proliferation rate, reduced production of immunoglobulin M and immunoglobulin G, and reduced proteasome and immunoproteasome proteolytic activities compared to WT B cells stimulated with anti-CD40 + IL-4. The results indicate that Taz is required to support T-cell-dependent signaling activation of mouse B cells.
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Affiliation(s)
- Hana M Zegallai
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Department of Pharmacology & Therapeutics, Rady Faculty of Health Sciences, Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, Canada
| | - Ejlal Abu-El-Rub
- Physiology and Pathophysiology, Department of Basic Medical Sciences, Faculty of Medicine, Yarmouk University, Irbid, Jordan
- Physiology and Pathophysiology, Rady Faculty of Health Sciences, Regenerative Medicine, University of Manitoba, Winnipeg, Canada
| | - Edgard M Mejia
- Department of Immunology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Genevieve C Sparagna
- Department of Medicine, Division of Cardiology, University of Colorado Anschutz Medical Center, Aurora, Denver CO, USA
| | - Laura K Cole
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Department of Pharmacology & Therapeutics, Rady Faculty of Health Sciences, Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, Canada
| | - Aaron J Marshall
- Department of Immunology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Grant M Hatch
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Department of Pharmacology & Therapeutics, Rady Faculty of Health Sciences, Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, Canada.
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6
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Zegallai HM, Abu-El-Rub E, Cole LK, Field J, Mejia EM, Gordon JW, Marshall AJ, Hatch GM. Tafazzin deficiency impairs mitochondrial metabolism and function of lipopolysaccharide activated B lymphocytes in mice. FASEB J 2021; 35:e22023. [PMID: 34767647 DOI: 10.1096/fj.202100811rr] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 10/05/2021] [Accepted: 10/19/2021] [Indexed: 01/21/2023]
Abstract
B lymphocytes are responsible for humoral immunity and play a key role in the immune response. Optimal mitochondrial function is required to support B cell activity during activation. We examined how deficiency of tafazzin, a cardiolipin remodeling enzyme required for mitochondrial function, alters the metabolic activity of B cells and their response to activation by lipopolysaccharide in mice. B cells were isolated from 3-month-old wild type or tafazzin knockdown mice and incubated for up to 72 h with lipopolysaccharide and cell proliferation, expression of cell surface markers, secretion of antibodies and chemokines, proteasome and immunoproteasome activities, and metabolic function determined. In addition, proteomic analysis was performed to identify altered levels of proteins involved in survival, immunogenic, proteasomal and mitochondrial processes. Compared to wild type lipopolysaccharide activated B cells, lipopolysaccharide activated tafazzin knockdown B cells exhibited significantly reduced proliferation, lowered expression of cluster of differentiation 86 and cluster of differentiation 69 surface markers, reduced secretion of immunoglobulin M antibody, reduced secretion of keratinocytes-derived chemokine and macrophage-inflammatory protein-2, reduced proteasome and immunoproteasome activities, and reduced mitochondrial respiration and glycolysis. Proteomic analysis revealed significant alterations in key protein targets that regulate cell survival, immunogenicity, proteasomal processing and mitochondrial function consistent with the findings of the above functional studies. The results indicate that the cardiolipin transacylase enzyme tafazzin plays a key role in regulating mouse B cell function and metabolic activity during activation through modulation of mitochondrial function.
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Affiliation(s)
- Hana M Zegallai
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba, Canada.,Department of Pharmacology & Therapeutics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Ejlal Abu-El-Rub
- Department of Physiology and Pathophysiology, Yarmouk University, Irbid, Jordan.,Department of Basic Medical Sciences, Faculty of Medicine, Yarmouk University, Irbid, Jordan.,Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Manitoba, Canada.,Department of Regenerative Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Laura K Cole
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba, Canada.,Department of Pharmacology & Therapeutics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Jared Field
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba, Canada.,Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Edgard M Mejia
- Department of Immunology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Joseph W Gordon
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba, Canada.,Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Manitoba, Canada.,College of Nursing, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Aaron J Marshall
- Department of Immunology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Grant M Hatch
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba, Canada.,Department of Pharmacology & Therapeutics, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
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7
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Mejia EM, Zegallai HM, Sparagna GC, Hatch GM. Reduced protein kinase C delta association with a higher molecular weight complex in mitochondria of Barth Syndrome lymphoblasts. bioRxiv 2021:2021.07.21.453087. [PMID: 34341795 PMCID: PMC8328083 DOI: 10.1101/2021.07.21.453087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The protein kinase C delta (PKCδ) signalosome exists as a high molecular weight complex in mitochondria and controls mitochondrial oxidative phosphorylation. Barth Syndrome (BTHS) is a rare X-linked genetic disease in which mitochondrial oxidative phosphorylation is impaired due to a mutation in the gene TAFAZZIN which results in reduction in the phospholipid cardiolipin and an accumulation of monolysocardiolipin. Here we examined if PKCδ association with a higher molecular weight complex was altered in mitochondria of BTHS lymphoblasts. Immunoblot analysis of blue native-polyacrylamide gel electrophoresis mitochondrial fractions revealed that PKCδ associated with a higher molecular weight complex in control lymphoblasts but this was markedly reduced in BTHS patient B lymphoblasts in spite of an increase in PKCδ protein expression. We hypothesize that the lack of PKCδ within this higher molecular weight complex may contribute to defective mitochondrial PKCδ signaling and thus to the bioenergetic defects observed in BTHS.
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Barazandeh AF, Mou Z, Ikeogu N, Mejia EM, Edechi CA, Zhang WW, Alizadeh J, Hatch GM, Ghavami S, Matlashewski G, Marshall AJ, Uzonna JE. The Phosphoenolpyruvate Carboxykinase Is a Key Metabolic Enzyme and Critical Virulence Factor of Leishmania major. J Immunol 2021; 206:1013-1026. [PMID: 33462138 DOI: 10.4049/jimmunol.2000517] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 12/14/2020] [Indexed: 11/19/2022]
Abstract
There is currently no effective vaccine against leishmaniasis because of the lack of sufficient knowledge about the Ags that stimulate host-protective and long-lasting T cell-mediated immunity. We previously identified Leishmania phosphoenolpyruvate carboxykinase (PEPCK, a gluconeogenic enzyme) as an immunodominant Ag that is expressed by both the insect (promastigote) and mammalian (amastigote) stages of the parasite. In this study, we investigated the role of PEPCK in metabolism, virulence, and immunopathogenicity of Leishmania major We show that targeted loss of PEPCK results in impaired proliferation of L. major in axenic culture and bone marrow-derived macrophages. Furthermore, the deficiency of PEPCK results in highly attenuated pathology in vivo. BALB/c mice infected with PEPCK-deficient parasites failed to develop any cutaneous lesions despite harboring parasites at the cutaneous site of infection. This was associated with a dramatic reduction in the frequency of cytokine (IFN-γ, IL-4, and IL-10)-producing CD4+ T cells in spleens and lymph nodes draining the infection site. Cells from mice infected with PEPCK-deficient parasites also produced significantly low levels of these cytokines into the culture supernatant following in vitro restimulation with soluble Leishmania Ag. PEPCK-deficient parasites exhibited significantly greater extracellular acidification rate, increased proton leak, and decreased ATP-coupling efficiency and oxygen consumption rates in comparison with their wild-type and addback counterparts. Taken together, these results show that PEPCK is a critical metabolic enzyme for Leishmania, and its deletion results in altered metabolic activity and attenuation of virulence.
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Affiliation(s)
- Aida Feiz Barazandeh
- Department of Immunology, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba R3T 0T5, Canada
| | - Zhirong Mou
- Department of Immunology, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba R3T 0T5, Canada
| | - Nnamdi Ikeogu
- Department of Immunology, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba R3T 0T5, Canada
| | - Edgard M Mejia
- Department of Immunology, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba R3T 0T5, Canada
| | - Chidalu A Edechi
- Department of Pathology, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Wen-Wei Zhang
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec H3A 0F4, Canada
| | - Javad Alizadeh
- Department of Human Anatomy and Cell Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Grant M Hatch
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada.,Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada; and.,Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Saeid Ghavami
- Department of Human Anatomy and Cell Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Greg Matlashewski
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec H3A 0F4, Canada
| | - Aaron J Marshall
- Department of Immunology, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba R3T 0T5, Canada
| | - Jude E Uzonna
- Department of Immunology, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba R3T 0T5, Canada;
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9
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Cole LK, Mejia EM, Sparagna GC, Vandel M, Xiang B, Han X, Dedousis N, Kaufman BA, Dolinsky VW, Hatch GM. Cardiolipin deficiency elevates susceptibility to a lipotoxic hypertrophic cardiomyopathy. J Mol Cell Cardiol 2020; 144:24-34. [PMID: 32418915 DOI: 10.1016/j.yjmcc.2020.05.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 05/04/2020] [Accepted: 05/06/2020] [Indexed: 02/08/2023]
Abstract
Cardiolipin (CL) is a unique tetra-acyl phospholipid localized to the inner mitochondrial membrane and essential for normal respiratory function. It has been previously reported that the failing human heart and several rodent models of cardiac pathology have a selective loss of CL. A rare genetic disease, Barth syndrome (BTHS), is similarly characterized by a cardiomyopathy due to reduced levels of cardiolipin. A mouse model of cardiolipin deficiency was recently developed by knocking-down the cardiolipin biosynthetic enzyme tafazzin (TAZ KD). These mice develop an age-dependent cardiomyopathy due to mitochondrial dysfunction. Since reduced mitochondrial capacity in the heart may promote the accumulation of lipids, we examined whether cardiolipin deficiency in the TAZ KD mice promotes the development of a lipotoxic cardiomyopathy. In addition, we investigated whether treatment with resveratrol, a small cardioprotective nutraceutical, attenuated the aberrant lipid accumulation and associated cardiomyopathy. Mice deficient in tafazzin and the wildtype littermate controls were fed a low-fat diet, or a high-fat diet with or without resveratrol for 16 weeks. In the absence of obesity, TAZ KD mice developed a hypertrophic cardiomyopathy characterized by reduced left-ventricle (LV) volume (~36%) and 30-50% increases in isovolumetric contraction (IVCT) and relaxation times (IVRT). The progression of cardiac hypertrophy with tafazzin-deficiency was associated with several underlying pathological processes including altered mitochondrial complex I mediated respiration, elevated oxidative damage (~50% increase in reactive oxygen species, ROS), the accumulation of triglyceride (~250%) as well as lipids associated with lipotoxicity (diacylglyceride ~70%, free-cholesterol ~44%, ceramide N:16-35%) compared to the low-fat fed controls. Treatment of TAZ KD mice with resveratrol maintained normal LV volumes and preserved systolic function of the heart. The beneficial effect of resveratrol on cardiac function was accompanied by a significant improvement in mitochondrial respiration, ROS production and oxidative damage to the myocardium. Resveratrol treatment also attenuated the development of cardiac steatosis in tafazzin-deficient mice through reduced de novo fatty acid synthesis. These results indicate for the first time that cardiolipin deficiency promotes the development of a hypertrophic lipotoxic cardiomyopathy. Furthermore, we determined that dietary resveratrol attenuates the cardiomyopathy by reducing ROS, cardiac steatosis and maintaining mitochondrial function.
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Affiliation(s)
- Laura K Cole
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Department of Pharmacology & Therapeutics, Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Edgard M Mejia
- Department of Immunology, University of Manitoba, Winnipeg, Canada
| | - Genevieve C Sparagna
- Department of Medicine, Division of Cardiology, University of Colorado Anschutz Medical Center Denver, Aurora, USA
| | - Marilyne Vandel
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Department of Pharmacology & Therapeutics, Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Bo Xiang
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Department of Pharmacology & Therapeutics, Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Xianlin Han
- Barshop Institute for Longevity and Aging Studies and the Department of Medicine-Diabetes, University of Texas Health Science Center at San Antonio, San Antonia, TX, USA
| | - Nikolaos Dedousis
- Center for Metabolism and Mitochondrial Medicine and the Vascular Medicine Institute, Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Brett A Kaufman
- Center for Metabolism and Mitochondrial Medicine and the Vascular Medicine Institute, Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Vernon W Dolinsky
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Department of Pharmacology & Therapeutics, Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Grant M Hatch
- Diabetes Research Envisioned and Accomplished in Manitoba (DREAM) Theme, Children's Hospital Research Institute of Manitoba, Department of Pharmacology & Therapeutics, Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada; Center for Research and Treatment of Atherosclerosis, University of Manitoba, Winnipeg, Canada.
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10
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Kost SEF, Saleh A, Mejia EM, Mostafizar M, Bouchard EDJ, Banerji V, Marshall AJ, Gibson SB, Katyal S, Johnston JB. Abstract 1891: Cross-resistance and synergy between idelalisib and bendamustine in chronic lymphocytic leukemia. Cancer Res 2018. [DOI: 10.1158/1538-7445.am2018-1891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Idelalisib (IDE) is an inhibitor of the δ isoform of PI3 kinase and has shown high activity in chronic lymphocytic leukemia (CLL) either when given alone or in combination with bendamustine (BEN) /rituximab (BR). In the present study, we have determined whether there is cross-resistance between BEN and IDE in primary CLL cells in vitro and whether synergy is observed upon combining these agents. In primary CLL cells in vitro, cross-resistance was not observed between BEN and IDE suggesting different modes of cytotoxicity. In contrast to BEN, sensitivity to IDE was not influenced by prior clinical treatment or the presence of a del 17p. Marked synergy in cytotoxicity was seen between BEN and IDE, which was paralleled by changes in γ-H2AX staining. These findings suggest that the synergistic antitumor effect was related to enhanced DNA damage by the drug combination. The degree of cytotoxic synergy varied and synergy was observed in some cases that were resistant to BEN or IDE, and those with del 17p. Synergy between BEN and IDE was also seen in the B cell lines, BJAB and I83, and in healthy donor peripheral blood mononuclear cells indicating that the phenomenon was not CLL-specific. To simulate the microenvironment, CLL cells were pre-stimulating with CD40L and IL4 prior to drug treatment. Interestingly this treatment caused the cells to become resistant to IDE, but BEN sensitivity was unaffected. However, combining BEN and IDE produced greater synergy than observed when cells were incubated without IL4/CD40. To examine the role of PI3Kδ for synergy, B cells from C57 BL/6 mice, both wild type and with non-functioning PI3Kδ protein, were exposed to BEN and/or IDE. Cells with the non-functioning PI3Kδ protein were more resistant to IDE than the wild-type cells and showed lesser synergy confirming the importance of this protein for the synergistic effect. In summary, these results confirm that IDE can be active against BEN-resistant CLL cells, while BEN may remain active against IDE-resistant samples, demonstrating different modes of anti-tumor activity. However, the unique yet inconsistent synergy seen between these two agents suggest an overlapping mechanism of action. Ongoing studies are evaluating the mechanism for this synergy.
Citation Format: Sara E. F. Kost, Ali Saleh, Edgard M. Mejia, Marina Mostafizar, Eric D. J. Bouchard, Versha Banerji, Aaron J. Marshall, Spencer B. Gibson, Sachin Katyal, James B. Johnston. Cross-resistance and synergy between idelalisib and bendamustine in chronic lymphocytic leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1891.
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Affiliation(s)
| | - Ali Saleh
- 1CancerCare Manitoba, Winnipeg, Manitoba, Canada
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11
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Jayachandran N, Mejia EM, Sheikholeslami K, Sher AA, Hou S, Hatch GM, Marshall AJ. TAPP Adaptors Control B Cell Metabolism by Modulating the Phosphatidylinositol 3-Kinase Signaling Pathway: A Novel Regulatory Circuit Preventing Autoimmunity. J I 2018; 201:406-416. [DOI: 10.4049/jimmunol.1701440] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 05/10/2018] [Indexed: 01/24/2023]
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12
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Mutz CN, Schwentner R, Aryee DNT, Bouchard EDJ, Mejia EM, Hatch GM, Kauer MO, Katschnig AM, Ban J, Garten A, Alonso J, Banerji V, Kovar H. EWS-FLI1 confers exquisite sensitivity to NAMPT inhibition in Ewing sarcoma cells. Oncotarget 2018; 8:24679-24693. [PMID: 28160567 PMCID: PMC5421879 DOI: 10.18632/oncotarget.14976] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 01/16/2017] [Indexed: 01/26/2023] Open
Abstract
Ewing sarcoma (EwS) is the second most common bone cancer in children and adolescents with a high metastatic potential. EwS development is driven by a specific chromosomal translocation resulting in the generation of a chimeric EWS-ETS transcription factor, most frequently EWS-FLI1. Nicotinamide adenine dinucleotide (NAD) is a key metabolite of energy metabolism involved in cellular redox reactions, DNA repair, and in the maintenance of genomic stability. This study describes targeting nicotinamide phosphoribosyltransferase (NAMPT), the rate-limiting enzyme of NAD synthesis, by FK866 in EwS cells. Here we report that blocking NAMPT leads to exhaustive NAD depletion in EwS cells, followed by a metabolic collapse and cell death. Using conditional EWS-FLI1 knockdown by doxycycline-inducible shRNA revealed that EWS-FLI1 depletion significantly reduces the sensitivity of EwS cells to NAMPT inhibition. Consistent with this finding, a comparison of 7 EwS cell lines of different genotypes with 5 Non-EwS cell lines and mesenchymal stem cells revealed significantly higher FK866 sensitivity of EWS-ETS positive EwS cells, with IC50 values mostly below 1nM. Taken together, our data reveal evidence of an important role of the NAMPT-mediated NAD salvage pathway in the energy homeostasis of EwS cells and suggest NAMPT inhibition as a potential new treatment approach for Ewing sarcoma.
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Affiliation(s)
- Cornelia N Mutz
- Children's Cancer Research Institute Vienna, St. Anna Kinderkrebsforschung, Vienna, Austria
| | - Raphaela Schwentner
- Children's Cancer Research Institute Vienna, St. Anna Kinderkrebsforschung, Vienna, Austria
| | - Dave N T Aryee
- Children's Cancer Research Institute Vienna, St. Anna Kinderkrebsforschung, Vienna, Austria.,Department of Pediatrics, Medical University Vienna, Vienna, Austria
| | - Eric D J Bouchard
- Department of Biochemistry and Medical Genetics, University of Manitoba, Research Institute in Oncology and Hematology (RIOH), CancerCare Manitoba, Winnipeg, Canada
| | - Edgard M Mejia
- Department of Pharmacology and Therapeutics, Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Grant M Hatch
- Department of Biochemistry and Medical Genetics, Center for Research and Treatment of Atherosclerosis, University of Manitoba, DREAM Children's Hospital Research Institute of Manitoba, Winnipeg, Canada
| | - Maximilian O Kauer
- Children's Cancer Research Institute Vienna, St. Anna Kinderkrebsforschung, Vienna, Austria
| | - Anna M Katschnig
- Children's Cancer Research Institute Vienna, St. Anna Kinderkrebsforschung, Vienna, Austria
| | - Jozef Ban
- Children's Cancer Research Institute Vienna, St. Anna Kinderkrebsforschung, Vienna, Austria
| | - Antje Garten
- Center for Pediatric Research Leipzig, Hospital for Children and Adolescents, University of Leipzig, Leipzig, Germany
| | - Javier Alonso
- Unidad de Tumores Sólidos Infantiles, Instituto de Investigación de Enfermedades Raras, ISCIII, Ctra, Madrid, Spain
| | - Versha Banerji
- Department of Biochemistry and Medical Genetics, University of Manitoba, Research Institute in Oncology and Hematology (RIOH), CancerCare Manitoba, Winnipeg, Canada
| | - Heinrich Kovar
- Children's Cancer Research Institute Vienna, St. Anna Kinderkrebsforschung, Vienna, Austria.,Department of Pediatrics, Medical University Vienna, Vienna, Austria
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13
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Mejia EM, Zegallai H, Bouchard ED, Banerji V, Ravandi A, Hatch GM. Expression of human monolysocardiolipin acyltransferase-1 improves mitochondrial function in Barth syndrome lymphoblasts. J Biol Chem 2018; 293:7564-7577. [PMID: 29563154 DOI: 10.1074/jbc.ra117.001024] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 03/01/2018] [Indexed: 12/12/2022] Open
Abstract
The mitochondrial polyglycerophospholipid cardiolipin (CL) is remodeled to obtain specific fatty acyl chains. This is predominantly accomplished by the transacylase enzyme tafazzin (TAZ). Barth syndrome (BTHS) patients with TAZ gene mutations exhibit impaired TAZ activity and loss in mitochondrial respiratory function. Previous studies identified monolysocardiolipin acyltransferase-1 (MLCL AT-1) as a mitochondrial enzyme capable of remodeling CL with fatty acid. In this study, we analyzed what relationship, if any, exists between TAZ and MLCL AT-1 with regard to CL remodeling and whether transfection of BTHS lymphoblasts with an MLCL AT-1 expression construct improves mitochondrial respiratory function. In healthy lymphoblasts, reduction in TAZ expression through TAZ RNAi transfection resulted in a compensatory increase in MLCL AT-1 mRNA, protein, and enzyme activity, but CL mass was unaltered. In contrast, BTHS lymphoblasts exhibited decreased TAZ gene and protein expression but in addition decreased MLCL AT-1 expression and CL mass. Transfection of BTHS lymphoblasts with MLCL AT-1 expression construct increased CL, improved mitochondrial basal respiration and protein leak, and decreased the proportion of cells producing superoxide but did not restore CL molecular species composition to control levels. In addition, BTHS lymphoblasts exhibited higher rates of glycolysis compared with healthy controls to compensate for reduced mitochondrial respiratory function. Mitochondrial supercomplex assembly was significantly impaired in BTHS lymphoblasts, and transfection of BTHS lymphoblasts with MLCL AT-1 expression construct did not restore supercomplex assembly. The results suggest that expression of MLCL AT-1 depends on functional TAZ in healthy cells. In addition, transfection of BTHS lymphoblasts with an MLCL AT-1 expression construct compensates, but not completely, for loss of mitochondrial respiratory function.
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Affiliation(s)
- Edgard M Mejia
- From the Department of Pharmacology and Therapeutics and.,Center for Research and Treatment of Atherosclerosis, University of Manitoba, Winnipeg, Manitoba R3E 0T6, Canada
| | - Hana Zegallai
- From the Department of Pharmacology and Therapeutics and
| | - Eric D Bouchard
- Research Institute in Oncology and Hematology, Cancer Care Manitoba, Winnipeg, Manitoba R3E 0V9, Canada
| | - Versha Banerji
- Research Institute in Oncology and Hematology, Cancer Care Manitoba, Winnipeg, Manitoba R3E 0V9, Canada
| | - Amir Ravandi
- Institute of Cardiovascular Sciences, St. Boniface Hospital Research Center, Winnipeg, Manitoba R2H 2A6, Canada, and
| | - Grant M Hatch
- From the Department of Pharmacology and Therapeutics and .,Center for Research and Treatment of Atherosclerosis, University of Manitoba, Winnipeg, Manitoba R3E 0T6, Canada.,Diabetes Research Envisioned and Accomplished in Manitoba (DREAM), Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba R3E 3P4, Canada
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14
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Mejia EM, Zinko JC, Hauff KD, Xu FY, Ravandi A, Hatch GM. Glucose Uptake and Triacylglycerol Synthesis Are Increased in Barth Syndrome Lymphoblasts. Lipids 2017; 52:161-165. [PMID: 28097490 DOI: 10.1007/s11745-017-4232-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 01/09/2017] [Indexed: 11/26/2022]
Abstract
Barth syndrome (BTHS) is an X-linked genetic disease resulting in loss of cardiolipin (Ptd2Gro). Patients may be predisposed to hypoglycemia and exhibit increases in whole-body glucose disposal rates and a higher fat mass percentage. We examined the reasons for this in BTHS lymphoblasts. BTHS lymphoblasts exhibited a 60% increase (p < 0.004) in 2-[1,2-3H(N)]deoxy-D-glucose uptake, a 40% increase (p < 0.01) in glucose transporter-3 protein expression, an increase in phosphorylated-adenosine monophosphate kinase (AMPK) and a 58% increase (p < 0.001) in the phosphorylated-AMPK/AMPK ratio compared to controls. In addition, BTHS lymphoblasts exhibited a 90% (p < 0.001) increase in D-[U-14C]glucose incorporated into 1,2,3-triacyl-sn-glycerol (TAG) and a 29% increase (p < 0.025) in 1,2-diacyl-sn-glycerol acyltransferase-2 activity compared to controls. Thus, BTHS lymphoblasts exhibit increased glucose transport and increased glucose utilization for TAG synthesis. These results may, in part, explain why BTHS patients exhibit an increase in whole-body glucose disposal rates, may be predisposed to hypoglycemia and exhibit a higher fat mass percentage.
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Affiliation(s)
- Edgard M Mejia
- Department of Pharmacology and Therapeutics, Faculty of Health Sciences, University of Manitoba, 753 McDermot Avenue, Winnipeg, MB, R3E 0W3, Canada
| | - James C Zinko
- Department of Pharmacology and Therapeutics, Faculty of Health Sciences, University of Manitoba, 753 McDermot Avenue, Winnipeg, MB, R3E 0W3, Canada
| | - Kristin D Hauff
- Department of Pharmacology and Therapeutics, Faculty of Health Sciences, University of Manitoba, 753 McDermot Avenue, Winnipeg, MB, R3E 0W3, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, Canada
| | - Fred Y Xu
- Department of Pharmacology and Therapeutics, Faculty of Health Sciences, University of Manitoba, 753 McDermot Avenue, Winnipeg, MB, R3E 0W3, Canada
| | - Amir Ravandi
- Department of Physiology and Pathophysiology, DREAM Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB, R3E 0T6, Canada
| | - Grant M Hatch
- Department of Pharmacology and Therapeutics, Faculty of Health Sciences, University of Manitoba, 753 McDermot Avenue, Winnipeg, MB, R3E 0W3, Canada.
- Biochemistry and Medical Genetics, Center for Research and Treatment of Atherosclerosis, DREAM Children's Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB, R3E 0T6, Canada.
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15
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Cole LK, Mejia EM, Vandel M, Sparagna GC, Claypool SM, Dyck-Chan L, Klein J, Hatch GM. Erratum. Impaired Cardiolipin Biosynthesis Prevents Hepatic Steatosis and Diet-Induced Obesity. Diabetes 2016;65:3289-3300. Diabetes 2017; 66:231. [PMID: 27856607 PMCID: PMC5379051 DOI: 10.2337/db17-er01a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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16
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Cole LK, Mejia EM, Vandel M, Sparagna GC, Claypool SM, Dyck-Chan L, Klein J, Hatch GM. Impaired Cardiolipin Biosynthesis Prevents Hepatic Steatosis and Diet-Induced Obesity. Diabetes 2016; 65:3289-3300. [PMID: 27495222 PMCID: PMC5079636 DOI: 10.2337/db16-0114] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 07/26/2016] [Indexed: 12/16/2022]
Abstract
Mitochondria are the nexus of energy metabolism, and consequently their dysfunction has been implicated in the development of metabolic complications and progression to insulin resistance and type 2 diabetes. The unique tetra-acyl phospholipid cardiolipin (CL) is located in the inner mitochondrial membrane, where it maintains mitochondrial integrity. Here we show that knockdown of Tafazzin (TAZ kd), a CL transacylase, in mice results in protection against the development of obesity, insulin resistance, and hepatic steatosis. We determined that hypermetabolism protected TAZ kd mice from weight gain. Unexpectedly, the large reduction of CL in the heart and skeletal muscle of TAZ kd mice was not mirrored in the liver. As a result, TAZ kd mice exhibited normal hepatic mitochondrial supercomplex formation and elevated hepatic fatty acid oxidation. Collectively, these studies identify a key role for hepatic CL remodeling in regulating susceptibility to insulin resistance and as a novel therapeutic target for diet-induced obesity.
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Affiliation(s)
- Laura K Cole
- Children's Hospital Research Institute of Manitoba, Department of Pharmacology & Therapeutics, Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Edgard M Mejia
- Children's Hospital Research Institute of Manitoba, Department of Pharmacology & Therapeutics, Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Marilyne Vandel
- Children's Hospital Research Institute of Manitoba, Department of Pharmacology & Therapeutics, Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | - Genevieve C Sparagna
- Department of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO
| | - Steven M Claypool
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Laura Dyck-Chan
- Children's Hospital Research Institute of Manitoba, Department of Pharmacology & Therapeutics, Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
| | | | - Grant M Hatch
- Children's Hospital Research Institute of Manitoba, Department of Pharmacology & Therapeutics, Faculty of Health Sciences, University of Manitoba, Winnipeg, Canada
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17
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Nguyen HM, Mejia EM, Chang W, Wang Y, Watson E, On N, Miller DW, Hatch GM. Reduction in cardiolipin decreases mitochondrial spare respiratory capacity and increases glucose transport into and across human brain cerebral microvascular endothelial cells. J Neurochem 2016; 139:68-80. [PMID: 27470495 DOI: 10.1111/jnc.13753] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 06/22/2016] [Accepted: 07/15/2016] [Indexed: 02/02/2023]
Abstract
Microvessel endothelial cells form part of the blood-brain barrier, a restrictively permeable interface that allows transport of only specific compounds into the brain. Cardiolipin is a mitochondrial phospholipid required for function of the electron transport chain and ATP generation. We examined the role of cardiolipin in maintaining mitochondrial function necessary to support barrier properties of brain microvessel endothelial cells. Knockdown of the terminal enzyme of cardiolipin synthesis, cardiolipin synthase, in hCMEC/D3 cells resulted in decreased cellular cardiolipin levels compared to controls. The reduction in cardiolipin resulted in decreased mitochondrial spare respiratory capacity, increased pyruvate kinase activity, and increased 2-deoxy-[(3) H]glucose uptake and glucose transporter-1 expression and localization to membranes in hCMEC/D3 cells compared to controls. The mechanism for the increase in glucose uptake was an increase in adenosine-5'-monophosphate kinase and protein kinase B activity and decreased glycogen synthase kinase 3 beta activity. Knockdown of cardiolipin synthase did not affect permeability of fluorescent dextran across confluent hCMEC/D3 monolayers grown on Transwell(®) inserts. In contrast, knockdown of cardiolipin synthase resulted in an increase in 2-deoxy-[(3) H]glucose transport across these monolayers compared to controls. The data indicate that in hCMEC/D3 cells, spare respiratory capacity is dependent on cardiolipin. In addition, reduction in cardiolipin in these cells alters their cellular energy status and this results in increased glucose transport into and across hCMEC/D3 monolayers. Microvessel endothelial cells form part of the blood-brain barrier, a restrictively permeable interface that allows transport of only specific compounds into the brain. In human adult brain endothelial cell hCMEC/D3 monolayers cultured on Transwell(®) plates, knockdown of cardiolipin synthase results in decrease in mitochondrial cardiolipin and decreased mitochondrial spare respiratory capacity. The reduced cardiolipin results in an increased activity of adenosine monophosphate kinase (pAMPK) and protein kinase B (pAKT) and decreased activity of glycogen synthase kinase 3 beta (pGSK3β) which results in elevated glucose transporter-1 (GLUT-1) expression and association with membranes. This in turn increases 2-dexoyglucose uptake from the apical medium into the cells with a resultant 2-deoxyglucose movement into the basolateral medium.
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Affiliation(s)
- Hieu M Nguyen
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada
| | - Edgard M Mejia
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada
| | - Wenguang Chang
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada
| | - Ying Wang
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada
| | - Emily Watson
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada
| | - Ngoc On
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada
| | - Donald W Miller
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada
| | - Grant M Hatch
- Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB, Canada. .,Biochemistry and Medical Genetics, Center for Research and Treatment of Atherosclerosis, University of Manitoba, DREAM Manitoba Institute of Child Health, Winnipeg, MB, Canada.
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18
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Mejia EM, Chau S, Sparagna GC, Sipione S, Hatch GM. Reduced Mitochondrial Function in Human Huntington Disease Lymphoblasts is Not Due to Alterations in Cardiolipin Metabolism or Mitochondrial Supercomplex Assembly. Lipids 2016; 51:561-9. [PMID: 26846325 DOI: 10.1007/s11745-015-4110-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 12/01/2015] [Indexed: 10/22/2022]
Abstract
Huntington's Disease (HD) is an autosomal dominant disease that occurs as a result of expansion of the trinucleotide repeat CAG (glutamine) on the HTT gene. HD patients exhibit various forms of mitochondrial dysfunction within neurons and peripheral tissues. Cardiolipin (Ptd2Gro) is a polyglycerophospholipid found exclusively in mitochondria and is important for maintaining mitochondrial function. We examined if altered Ptd2Gro metabolism was involved in the mitochondrial dysfunction associated with HD. Mitochondrial basal respiration, spare respiratory capacity, ATP coupling efficiency and rate of glycolysis were markedly diminished in Epstein-Barr virus transformed HD lymphoblasts compared to controls (CTRL). Mitochondrial supercomplex formation and Complex I activity within these supercomplexes did not vary between HD patients with different length of CAG repeats and appeared unaltered compared to CTRL. In contrast, in vitro Complex I enzyme activity in mitochondrial enriched samples was reduced in HD lymphoblasts compared to CTRL. The total cellular pool size of Ptd2Gro and its synthesis/remodeling from [(3)H]acetate/[(14)C]oleate were unaltered in HD lymphoblasts compared to CTRL. In addition, the molecular species of Ptd2Gro were essentially unaltered in HD lymphoblasts compared to CTRL. We conclude that compared to CTRL lymphoblasts, HD lymphoblasts display impaired mitochondrial basal respiration, spare respiratory capacity, ATP coupling efficiency and rate of glycolysis with any pathological CAG repeat length, but this is not due to alterations in Ptd2Gro metabolism. We suggest that HD patient lymphoblasts may be a useful model to study defective energy metabolism that does not involve alterations in Ptd2Gro metabolism.
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Affiliation(s)
- Edgard M Mejia
- Department of Pharmacology and Therapeutics, Faculty of Health Sciences, University of Manitoba, 501C-715 McDermot Avenue, Winnipeg, MB, R3E 3P4, Canada
| | - Sarah Chau
- Department of Medicine, Division of Cardiology, University of Colorado Denver Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Genevieve C Sparagna
- Department of Medicine, Division of Cardiology, University of Colorado Denver Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Simonetta Sipione
- Department of Pharmacology, University of Alberta, Edmonton, AB, T6G2S2, Canada
| | - Grant M Hatch
- Department of Pharmacology and Therapeutics, Faculty of Health Sciences, University of Manitoba, 501C-715 McDermot Avenue, Winnipeg, MB, R3E 3P4, Canada. .,Department of Biochemistry and Medical Genetics, Center for Research and Treatment of Atherosclerosis, University of Manitoba, DREAM Children's Hospital Research Institute of Manitoba, Winnipeg, MB, R3E 0T6, Canada.
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Mejia EM, Cole LK, Hatch GM. Cardiolipin metabolism and the role it plays in heart failure and mitochondrial supercomplex formation. Cardiovasc Hematol Disord Drug Targets 2015; 14:98-106. [PMID: 24801725 DOI: 10.2174/1871529x14666140505123753] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 04/25/2014] [Accepted: 04/28/2014] [Indexed: 11/22/2022]
Abstract
Cardiolipin is a major membrane phospholipid in the mitochondria and is essential for cellular energy metabolism mediated through mitochondrial oxidative phosphorylation. Recent studies indicate that it plays a diverse role in cellular metabolism. Eukaryotic cardiolipin is synthesized de novo from phosphatidic acid via the cytidine-5'-diphosphate-1,2-diacyl-sn-glycerol pathway and is deacylated to monolysocardiolipin in order for it to be remodelled into the form that is observed in mitochondrial membranes. This resynthesis of deacylated cardiolipin from monolysocardiolipin occurs via the Barth Syndrome gene product tafazzin and acyllysocardiolipin acyltransferase-1, monolysocardiolipin acyltransferase-1 and the alpha subunit of trifunctional protein. Heart failure is a disease condition in which the amount and type of cardiolipin is altered. Several animal models have been generated to study the role of altered cardiolipin in heart failure. In many of these models loss of the tetralinoleoyl-cardiolipin species is observed during the development of the heart failure. In the doxycycline inducible short hairpin RNA tafazzin knock down mouse, loss of tetralinoleoyl-cardiolipin is associated with a mitochondrial bioenergetic disruption. Reduction in mitochondrial supercomplex formation and NADH dehydrogenase activity within these supercomplexes is observed. Modulation of CL fatty acyl composition may serve as a therapeutic strategy for the treatment of several pathologies including cardiac dysfunction.We propose that increasing cardiolipin may improve mitochondrial function and potentially serve as a therapy for diseases which exhibit mitochondrial dysfunction involving reduced cardiolipin.
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Affiliation(s)
| | | | - Grant M Hatch
- Department of Pharmacology & Therapeutics, University of Manitoba, Manitoba Institute of Child Health, 501C-715 McDermot Avenue, Winnipeg, Manitoba, Canada, R3E 3P4.
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Bouchard EDJ, Mejia EM, Gehrke I, Poeppl AG, Hewitt D, Johnston JB, Gibson SB, Hatch GM, Banerji V. Abstract 3052: NAMPT inhibition induces mitochondrial dysfunction leading to apoptosis in chronic lymphocytic leukemia cells. Cancer Res 2015. [DOI: 10.1158/1538-7445.am2015-3052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
We have previously shown that the NAD depletion following inhibition of NAMPT by the NA-mimetic FK866 leads to loss of mitochondrial membrane potential, depletion of cellular ATP, cytochrome C release and caspase activation in primary Chronic Lymphocytic Leukemia (CLL) cells in vitro, and that these events are coupled with an increased production of reactive oxygen species uncharacteristic of metabolic inhibition. In the present study we characterize the effect of NAD depletion on CLL mitochondria and the downstream mechanism of cell death.
We profiled the mitochondrial respiration of CLL cells and control B-lymphocytes, by extracellular flux analysis, over the 48 hours following FK866 treatment and found time-dependant inhibition of respiratory capacity consistent with disruption of the electron transport chain (ETC) in CLL cells. This led to suppression of basal respiration concomitant with the rise in ROS and approximately one day before loss of cellular viability. Interestingly, Zap70-positive CLL cells exhibited increased mitochondrial respiration and respiratory capacity over Zap70-negative CLL cells, but responded similarly to NAMPT inhibition. Additionally, mitochondrial respiration was not effected by NAMPT inhibition in control B-lymphocytes.
Increase autophagic flux, caspase-dependant apoptosis and mitochondrio-nuclear translocation of Apoptosis Inducing Factor (AIF) were detected by western blot. However, neither pan-caspase inhibition with Z-VAD-fmk nor inhibition of autophagy with 3-methyladenine were sufficient to prevent FK866-induced CLL cell death. We conclude that NAD depletion following inhibition of NAMPT leads to disruption of the mitochondrial ETC in CLL cells, leading to mitochondrial initiation of the intrinsic apoptosis pathway. As healthy B-lymphocytes are resistant to this NAD depletion, these downstream effects are also selective for malignant cells.
We are currently working to characterize the roles of NAD and Zap70 in the regulation and function of the CLL ETC. This will not only lead to an improved understanding of CLL metabolism, but will also inform new therapeutic strategies that will effectively employ NAMPT inhibition to treat this yet-incurable disease.
Citation Format: Eric DJ Bouchard, Edgard M. Mejia, Iris Gehrke, Armando G. Poeppl, Donna Hewitt, James B. Johnston, Spencer B. Gibson, Grant M. Hatch, Versha Banerji. NAMPT inhibition induces mitochondrial dysfunction leading to apoptosis in chronic lymphocytic leukemia cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3052. doi:10.1158/1538-7445.AM2015-3052
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Affiliation(s)
| | | | - Iris Gehrke
- 2CancerCare Manitoba, Winnipeg, Manitoba, Canada
| | | | - Donna Hewitt
- 2CancerCare Manitoba, Winnipeg, Manitoba, Canada
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Abstract
Cardiolipin is a major phospholipid in mitochondria and is involved in the generation of cellular energy in the form of ATP. In mammalian and eukaryotic cells it is synthesized via the cytidine-5'-diphosphate-1,2-diacyl-sn-glycerol phosphate pathway. This brief review will describe some of the more recent studies on mammalian cardiolipin biosynthesis and provide an overview of regulation of cardiolipin biosynthesis. In addition, the important role that this key phospholipid plays in disease processes including heart failure, diabetes, thyroid hormone disease and the genetic disease Barth Syndrome will be discussed.
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Affiliation(s)
- Edgard M Mejia
- Department of Pharmacology and Therapeutics, Center for Research and Treatment of Atherosclerosis, University of Manitoba, DREAM Manitoba Institute of Child Health, Winnipeg, Manitoba, Canada
| | - Hieu Nguyen
- Department of Pharmacology and Therapeutics, Center for Research and Treatment of Atherosclerosis, University of Manitoba, DREAM Manitoba Institute of Child Health, Winnipeg, Manitoba, Canada
| | - Grant M Hatch
- Department of Pharmacology and Therapeutics, Center for Research and Treatment of Atherosclerosis, University of Manitoba, DREAM Manitoba Institute of Child Health, Winnipeg, Manitoba, Canada; Department of Biochemistry and Medical Genetics, Center for Research and Treatment of Atherosclerosis, University of Manitoba, DREAM Manitoba Institute of Child Health, Winnipeg, Manitoba, Canada.
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Taylor WA, Mejia EM, Mitchell RW, Choy PC, Sparagna GC, Hatch GM. Human trifunctional protein alpha links cardiolipin remodeling to beta-oxidation. PLoS One 2012; 7:e48628. [PMID: 23152787 PMCID: PMC3494688 DOI: 10.1371/journal.pone.0048628] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Accepted: 10/02/2012] [Indexed: 12/19/2022] Open
Abstract
Cardiolipin (CL) is a mitochondrial membrane phospholipid which plays a key role in apoptosis and supports mitochondrial respiratory chain complexes involved in the generation of ATP. In order to facilitate its role CL must be remodeled with appropriate fatty acids. We previously identified a human monolysocardiolipin acyltransferase activity which remodels CL via acylation of monolysocardiolipin (MLCL) to CL and was identical to the alpha subunit of trifunctional protein (αTFP) lacking the first 227 amino acids. Full length αTFP is an enzyme that plays a prominent role in mitochondrial β-oxidation, and in this study we assessed the role, if any, which this metabolic enzyme plays in the remodeling of CL. Purified human recombinant αTFP exhibited acyl-CoA acyltransferase activity in the acylation of MLCL to CL with linoleoyl-CoA, oleoyl-CoA and palmitoyl-CoA as substrates. Expression of αTFP increased radioactive linoleate or oleate or palmitate incorporation into CL in HeLa cells. Expression of αTFP in Barth Syndrome lymphoblasts, which exhibit reduced tetralinoleoyl-CL, elevated linoleoyl-CoA acylation of MLCL to CL in vitro, increased mitochondrial respiratory Complex proteins and increased linoleate-containing species of CL. Knock down of αTFP in Barth Syndrome lymphoblasts resulted in greater accumulation of MLCL than those with normal αTFP levels. The results clearly indicate that the human αTFP exhibits MLCL acyltransferase activity for the resynthesis of CL from MLCL and directly links an enzyme of mitochondrial β-oxidation to CL remodeling.
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Affiliation(s)
- William A. Taylor
- Department of Pharmacology and Therapeutics, Center for Research and Treatment of Atherosclerosis, Manitoba Institute of Child Health, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Edgard M. Mejia
- Department of Pharmacology and Therapeutics, Center for Research and Treatment of Atherosclerosis, Manitoba Institute of Child Health, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Ryan W. Mitchell
- Department of Pharmacology and Therapeutics, Center for Research and Treatment of Atherosclerosis, Manitoba Institute of Child Health, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Patrick C. Choy
- Biochemistry and Medical Genetics, Center for Research and Treatment of Atherosclerosis, Manitoba Institute of Child Health, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Genevieve C. Sparagna
- Department of Integrative Physiology, University of Colorado at Boulder, Boulder, Colorado, United States of America
| | - Grant M. Hatch
- Department of Pharmacology and Therapeutics, Center for Research and Treatment of Atherosclerosis, Manitoba Institute of Child Health, University of Manitoba, Winnipeg, Manitoba, Canada
- Biochemistry and Medical Genetics, Center for Research and Treatment of Atherosclerosis, Manitoba Institute of Child Health, University of Manitoba, Winnipeg, Manitoba, Canada
- * E-mail:
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Mejia EM, Alvarez OA, Lee M. Endometriosis with massive bloody ascites. J Am Board Fam Pract 1997; 10:59-61. [PMID: 9018665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- E M Mejia
- Department of Medicine, University of Texas Health Science Center, San Antonio 78284-7878, USA
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Abstract
Our case report illustrates the clinicopathologic features of this rare vascular lesion and highlights that phlebectasia should be considered as a cause of gastrointestinal bleeding of undetermined etiology in adult patients.
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Affiliation(s)
- E M Mejia
- Department of Medicine, University of Texas Health Science Center, San Antonio 78284-7878, USA
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