1
|
Alva R, Wiebe JE, Stuart JA. Revisiting reactive oxygen species production in hypoxia. Pflugers Arch 2024:10.1007/s00424-024-02986-1. [PMID: 38955833 DOI: 10.1007/s00424-024-02986-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 06/20/2024] [Accepted: 06/24/2024] [Indexed: 07/04/2024]
Abstract
Cellular responses to hypoxia are crucial in various physiological and pathophysiological contexts and have thus been extensively studied. This has led to a comprehensive understanding of the transcriptional response to hypoxia, which is regulated by hypoxia-inducible factors (HIFs). However, the detailed molecular mechanisms of HIF regulation in hypoxia remain incompletely understood. In particular, there is controversy surrounding the production of mitochondrial reactive oxygen species (ROS) in hypoxia and how this affects the stabilization and activity of HIFs. This review examines this controversy and attempts to shed light on its origin. We discuss the role of physioxia versus normoxia as baseline conditions that can affect the subsequent cellular response to hypoxia and highlight the paucity of data on pericellular oxygen levels in most experiments, leading to variable levels of hypoxia that might progress to anoxia over time. We analyze the different outcomes reported in isolated mitochondria, versus intact cells or whole organisms, and evaluate the reliability of various ROS-detecting tools. Finally, we examine the cell-type and context specificity of oxygen's various effects. We conclude that while recent evidence suggests that the effect of hypoxia on ROS production is highly dependent on the cell type and the duration of exposure, efforts should be made to conduct experiments under carefully controlled, physiological microenvironmental conditions in order to rule out potential artifacts and improve reproducibility in research.
Collapse
Affiliation(s)
- Ricardo Alva
- Department of Biological Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada.
| | - Jacob E Wiebe
- Department of Biological Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada
| | - Jeffrey A Stuart
- Department of Biological Sciences, Brock University, St. Catharines, ON, L2S 3A1, Canada.
| |
Collapse
|
2
|
Kaynezhad P, Tachtsidis I, Sivaprasad S, Jeffery G. Watching the human retina breath in real time and the slowing of mitochondrial respiration with age. Sci Rep 2023; 13:6445. [PMID: 37081065 PMCID: PMC10119193 DOI: 10.1038/s41598-023-32897-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 04/04/2023] [Indexed: 04/22/2023] Open
Abstract
The retina has the greatest metabolic demand in the body particularly in dark adaptation when its sensitivity is enhanced. This requires elevated level of perfusion to sustain mitochondrial activity. However, mitochondrial performance declines with age leading to reduced adaptive ability. We assessed human retina metabolism in vivo using broad band near-infrared spectroscopy (bNIRS), which records colour changes in mitochondria and blood as retinal metabolism shifts in response to changes in environmental luminance. We demonstrate a significant sustained rise in mitochondrial oxidative metabolism in the first 3 min of darkness in subjects under 50 years old. This was not seen in those over 50 years. Choroidal oxygenation declines in < 50 s as mitochondrial metabolism increases, but gradually rises in the > 50 s. Significant group differences in blood oxygenation are apparent in the first 6 min, consistent with mitochondrial demand leading hemodynamic changes. A greater coupling between mitochondrial oxidative metabolism with hemodynamics is revealed in subjects older than 50, possibly due to reduced capacity in the older retina. Rapid in vivo assessment of retinal metabolism with bNIRS provides a route to understanding fundamental physiology and early identification of retinal disease before pathology is established.
Collapse
Affiliation(s)
- Pardis Kaynezhad
- Institute of Ophthalmology, University College London, 11-43 Bath St, London, EC1V9EL, UK
| | - Ilias Tachtsidis
- Department of Medical Physics and Biomedical Engineering, University College London, Gower St, London, WC1E6BT, UK
| | - Sobha Sivaprasad
- Institute of Ophthalmology, University College London, 11-43 Bath St, London, EC1V9EL, UK
| | - Glen Jeffery
- Institute of Ophthalmology, University College London, 11-43 Bath St, London, EC1V9EL, UK.
| |
Collapse
|
3
|
Ge C, Huang X, Zhang S, Yuan M, Tan Z, Xu C, Jie Q, Zhang J, Zou J, Zhu Y, Feng D, Zhang Y, Aa J. In vitro co-culture systems of hepatic and intestinal cells for cellular pharmacokinetic and pharmacodynamic studies of capecitabine against colorectal cancer. Cancer Cell Int 2023; 23:14. [PMID: 36717845 PMCID: PMC9887786 DOI: 10.1186/s12935-023-02853-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 01/15/2023] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND As a prodrug of 5-fluorouracil (5-FU), orally administrated capecitabine (CAP) undergoes preliminary conversion into active metabolites in the liver and then releases 5-FU in the gut to exert the anti-tumor activity. Since metabolic changes of CAP play a key role in its activation, a single kind of intestinal or hepatic cell can never be used in vitro to evaluate the pharmacokinetics (PK) and pharmacodynamics (PD) nature. Hence, we aimed to establish a novel in vitro system to effectively assess the PK and PD of these kinds of prodrugs. METHODS Co-culture cellular models were established by simultaneously using colorectal cancer (CRC) and hepatocarcinoma cell lines in one system. Cell Counting Kit-8 (CCK-8) and flow cytometric analysis were used to evaluate cell viability and apoptosis, respectively. Apoptosis-related protein expression levels were measured using western blot analysis. A selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for cellular PK in co-culture models. RESULTS CAP had little anti-proliferative effect on the five monolayer CRC cell lines (SW480, LoVo, HCT-8, HCT-116 and SW620) or the hepatocarcinoma cell line (HepG2). However, CAP exerted marked anti-tumor activities on each of the CRC cell lines in the co-culture models containing both CRC and hepatocarcinoma cell lines, although its effect on the five CRC cell lines varied. Moreover, after pre-incubation of CAP with HepG2 cells, the culture media containing the active metabolites of CAP also showed an anti-tumor effect on the five CRC cell lines, indicating the crucial role of hepatic cells in the activation of CAP. CONCLUSION The simple and cost‑effective co-culture models with both CRC and hepatocarcinoma cells could mimic the in vivo process of a prodrug dependent on metabolic conversion to active metabolites in the liver, providing a valuable strategy for evaluating the PK and PD characteristics of CAP-like prodrugs in vitro at the early stage of drug development.
Collapse
Affiliation(s)
- Chun Ge
- grid.89957.3a0000 0000 9255 8984Department of Pharmacy, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006 China ,grid.89957.3a0000 0000 9255 8984Department of Clinical Pharmacology Lab, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006 China ,grid.254147.10000 0000 9776 7793Department of Clinical Pharmacy, School of Basic Medicine & Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198 China
| | - Xintong Huang
- grid.254147.10000 0000 9776 7793Department of Clinical Pharmacy, School of Basic Medicine & Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198 China
| | - Sujie Zhang
- grid.254147.10000 0000 9776 7793Department of Clinical Pharmacy, School of Basic Medicine & Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198 China
| | - Man Yuan
- grid.254147.10000 0000 9776 7793Department of Clinical Pharmacy, School of Basic Medicine & Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198 China
| | - Zhaoyi Tan
- grid.254147.10000 0000 9776 7793Key Laboratory of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009 China
| | - Chen Xu
- grid.254147.10000 0000 9776 7793Key Laboratory of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009 China
| | - Qiong Jie
- grid.89957.3a0000 0000 9255 8984Department of Pharmacy, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006 China ,grid.89957.3a0000 0000 9255 8984Department of Clinical Pharmacology Lab, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006 China ,grid.254147.10000 0000 9776 7793Department of Clinical Pharmacy, School of Basic Medicine & Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198 China
| | - Jingjing Zhang
- grid.89957.3a0000 0000 9255 8984Department of Pharmacy, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006 China ,grid.89957.3a0000 0000 9255 8984Department of Clinical Pharmacology Lab, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006 China ,grid.254147.10000 0000 9776 7793Department of Clinical Pharmacy, School of Basic Medicine & Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198 China
| | - Jianjun Zou
- grid.89957.3a0000 0000 9255 8984Department of Pharmacy, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006 China ,grid.89957.3a0000 0000 9255 8984Department of Clinical Pharmacology Lab, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006 China ,grid.254147.10000 0000 9776 7793Department of Clinical Pharmacy, School of Basic Medicine & Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198 China
| | - Yubing Zhu
- grid.89957.3a0000 0000 9255 8984Department of Pharmacy, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006 China ,grid.89957.3a0000 0000 9255 8984Department of Clinical Pharmacology Lab, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006 China ,grid.254147.10000 0000 9776 7793Department of Clinical Pharmacy, School of Basic Medicine & Clinical Pharmacy, China Pharmaceutical University, Nanjing, 211198 China
| | - Dong Feng
- Nanjing Southern Pharmaceutical Technology Co., Ltd., Nanjing, 211100 China
| | - Yue Zhang
- grid.254147.10000 0000 9776 7793Key Laboratory of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009 China
| | - Jiye Aa
- grid.254147.10000 0000 9776 7793Key Laboratory of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 210009 China
| |
Collapse
|
4
|
Steinert JR, Amal H. The contribution of an imbalanced redox signalling to neurological and neurodegenerative conditions. Free Radic Biol Med 2023; 194:71-83. [PMID: 36435368 DOI: 10.1016/j.freeradbiomed.2022.11.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/17/2022] [Accepted: 11/22/2022] [Indexed: 11/25/2022]
Abstract
Nitric oxide and other redox active molecules such as oxygen free radicals provide essential signalling in diverse neuronal functions, but their excess production and insufficient scavenging induces cytotoxic redox stress which is associated with numerous neurodegenerative and neurological conditions. A further component of redox signalling is mediated by a homeostatic regulation of divalent metal ions, the imbalance of which contributes to neuronal dysfunction. Additional antioxidant molecules such as glutathione and enzymes such as super oxide dismutase are involved in maintaining a physiological redox status within neurons. When cellular processes are perturbed and generation of free radicals overwhelms the antioxidants capacity of the neurons, a resulting redox damage leads to neuronal dysfunction and cell death. Cellular sources for production of redox-active molecules may include NADPH oxidases, mitochondria, cytochrome P450 and nitric oxide (NO)-generating enzymes, such as endothelial, neuronal and inducible NO synthases. Several neurodegenerative and developmental neurological conditions are associated with an imbalanced redox state as a result of neuroinflammatory processes leading to nitrosative and oxidative stress. Ongoing research aims at understanding the causes and consequences of such imbalanced redox homeostasis and its role in neuronal dysfunction.
Collapse
Affiliation(s)
- Joern R Steinert
- Division of Physiology, Pharmacology and Neuroscience, University of Nottingham, School of Life Sciences, Nottingham, NG7 2NR, UK.
| | - Haitham Amal
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel.
| |
Collapse
|
5
|
Alva R, Moradi F, Liang P, Stuart JA. Culture of Cancer Cells at Physiological Oxygen Levels Affects Gene Expression in a Cell-Type Specific Manner. Biomolecules 2022; 12:1684. [PMID: 36421698 PMCID: PMC9688152 DOI: 10.3390/biom12111684] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 11/03/2022] [Accepted: 11/11/2022] [Indexed: 02/26/2024] Open
Abstract
Standard cell culture is routinely performed at supraphysiological oxygen levels (~18% O2). Conversely, O2 levels in most mammalian tissues range from 1-6% (physioxia). Such hyperoxic conditions in cell culture can alter reactive oxygen species (ROS) production, metabolism, mitochondrial networks, and response to drugs and hormones. The aim of this study was to investigate the transcriptional response to different O2 levels and determine whether it is similar across cell lines, or cell line-specific. Using RNA-seq, we performed differential gene expression and functional enrichment analyses in four human cancer cell lines, LNCaP, Huh-7, PC-3, and SH-SY5Y cultured at either 5% or 18% O2 for 14 days. We found that O2 levels affected transcript abundance of thousands of genes, with the affected genes having little overlap between cell lines. Functional enrichment analysis also revealed different processes and pathways being affected by O2 in each cell line. Interestingly, most of the top differentially expressed genes are involved in cancer biology, which highlights the importance of O2 levels in cancer cell research. Further, we observed several hypoxia-inducible factor (HIF) targets, HIF-2α targets particularly, upregulated at 5% O2, consistent with a role for HIFs in physioxia. O2 levels also differentially induced the transcription of mitochondria-encoded genes in most cell lines. Finally, by comparing our transcriptomic data from LNCaP and PC-3 with datasets from the Prostate Cancer Transcriptome Atlas, a correlation between genes upregulated at 5% O2 in LNCaP cells and the in vivo prostate cancer transcriptome was found. We conclude that the transcriptional response to O2 over the range from 5-18% is robust and highly cell-type specific. This latter finding indicates that the effects of O2 levels are difficult to predict and thus highlights the importance of regulating O2 in cell culture.
Collapse
Affiliation(s)
- Ricardo Alva
- Department of Biological Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Fereshteh Moradi
- Department of Biological Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Ping Liang
- Department of Biological Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
- Centre for Biotechnology, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - Jeffrey A. Stuart
- Department of Biological Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
- Centre for Biotechnology, Brock University, St. Catharines, ON L2S 3A1, Canada
| |
Collapse
|
6
|
Aktories P, Petry P, Glatz P, Andrieux G, Oschwald A, Botterer H, Gorka O, Erny D, Boerries M, Henneke P, Groß O, Prinz M, Kierdorf K. An improved organotypic cell culture system to study tissue-resident macrophages ex vivo. CELL REPORTS METHODS 2022; 2:100260. [PMID: 36046625 PMCID: PMC9421540 DOI: 10.1016/j.crmeth.2022.100260] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 02/11/2022] [Accepted: 07/06/2022] [Indexed: 12/02/2022]
Abstract
Tissue-resident macrophages (TRMs) perform organ-specific functions that are dependent on factors such as hematopoietic origin, local environment, and biological influences. A diverse range of in vitro culture systems have been developed to decipher TRM functions, including bone marrow-derived macrophages (BMDMs), induced pluripotent stem cell (iPSC)-derived TRMs, or immortalized cell lines. However, despite the usefulness of such systems, there are notable limitations. Attempts to culture primary macrophages often require purification of cells and lack a high cell yield and consistent phenotype. Here, we aimed to address these limitations by establishing an organotypic primary cell culture protocol. We obtained long-term monocultures of macrophages derived from distinct organs without prior purification using specific growth factors and tissue normoxic conditions that largely conserved a TRM-like identity in vitro. Thus, this organotypic system offers an ideal screening platform for primary macrophages from different organs that can be used for a wide range of assays and readouts.
Collapse
Affiliation(s)
- Philipp Aktories
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Philippe Petry
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Paulo Glatz
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Geoffroy Andrieux
- Institute of Medical Bioinformatics and Systems Medicine, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Alexander Oschwald
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Hannah Botterer
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Oliver Gorka
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Daniel Erny
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- Berta-Ottenstein-Program for Advanced Clinician Scientists, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Melanie Boerries
- Institute of Medical Bioinformatics and Systems Medicine, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- German Cancer Consortium (DKTK), Partner Site Freiburg, and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Philipp Henneke
- CIBSS-Center for Integrative Biological Signaling Studies, University of Freiburg, 79104 Freiburg, Germany
- Institute for Immunodeficiency, Center for Chronic Immunodeficiency, and Center for Pediatrics and Adolescent Medicine, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Olaf Groß
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- Signaling Research Centers BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
| | - Marco Prinz
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- Signaling Research Centers BIOSS and CIBSS, University of Freiburg, 79104 Freiburg, Germany
| | - Katrin Kierdorf
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- CIBSS-Center for Integrative Biological Signaling Studies, University of Freiburg, 79104 Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| |
Collapse
|
7
|
Gardner G, Moradi F, Moffatt C, Cliche M, Garlisi B, Gratton J, Mehmood F, Stuart JA. Rapid nutrient depletion to below the physiological range by cancer cells cultured in Plasmax. Am J Physiol Cell Physiol 2022; 323:C823-C834. [DOI: 10.1152/ajpcell.00403.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mammalian cell culture is a fundamental tool used to study living cells. Presently, the standard protocol for performing cell culture involves the use of commercial media that contain an excess of nutrients. While this reduces the likelihood of cell starvation, it creates non-physiologic culture conditions that have been shown to 're-wire' cellular metabolism. Recently, researchers have developed new media like Plasmax, formulated to approximate the nutrient composition of human blood plasma. Although this represents an improvement in cell culture practice, physiologic media may be vulnerable to nutrient depletion. In this study we directly addressed this concern by measuring the rates of glucose and amino acid depletion from Plasmax in several cancer cell lines (PC-3, LNCaP, MCF-7, SH-SY5Y) over 48 hours. In all cell lines, depletion of glucose from Plasmax was rapid such that, by 48h, cells were hypoglycemic (<2mM glucose). Most amino acids were similarly rapidly depleted to sub-physiological levels by 48h. In contrast, glucose and most amino acids remained within the physiological range at 24h. When the experiment was done at physiological oxygen (5%) versus standard (18%) with LNCaP cells, no effect on glucose or amino acid consumption was observed. Using RNA sequencing, we show that this nutrient depletion is associated with enrichment of starvation responses, apoptotic signalling, and endoplasmic reticulum stress. A shift from glycolytic metabolism to mitochondrial respiration at 5% O2 was also measured using Seahorse analysis. Taken together, these results exemplify the metabolic considerations for Plasmax, highlighting that cell culture in Plasmax requires daily media exchange.
Collapse
Affiliation(s)
- Georgina Gardner
- Department of Biological Sciences, Brock University, St Catharines, Ontario, Canada
| | - Feresteh Moradi
- Department of Biological Sciences, Brock University, St Catharines, Ontario, Canada
| | - Christopher Moffatt
- Department of Biological Sciences, Brock University, St Catharines, Ontario, Canada
| | - Meagan Cliche
- Department of Biological Sciences, Brock University, St Catharines, Ontario, Canada
| | - Bianca Garlisi
- Department of Biological Sciences, Brock University, St Catharines, Ontario, Canada
| | - John Gratton
- Department of Biological Sciences, Brock University, St Catharines, Ontario, Canada
| | - Fatima Mehmood
- Department of Biological Sciences, Brock University, St Catharines, Ontario, Canada
| | - Jeffrey A. Stuart
- Department of Biological Sciences, Brock University, St Catharines, Ontario, Canada
| |
Collapse
|
8
|
Atherton E, Hu Y, Brown S, Papiez E, Ling V, Colvin V, Borton D. A 3D in vitro model of the device-tissue interface: Functional and structural symptoms of innate neuroinflammation are mitigated by antioxidant ceria nanoparticles. J Neural Eng 2022; 19. [PMID: 35447619 DOI: 10.1088/1741-2552/ac6908] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 04/20/2022] [Indexed: 11/12/2022]
Abstract
OBJECTIVE The recording instability of neural implants due to neuroinflammation at the device-tissue interface is a primary roadblock to broad adoption of brain-machine interfaces. While a multiphasic immune response, marked by glial scaring, oxidative stress (OS), and neurodegeneration, is well-characterized, the independent contributions of systemic and local "innate" immune responses are not well-understood. We aimed to understand and mitigate the isolated the innate neuroinflammatory response to devices. APPROACH Three-dimensional primary neural cultures provide a unique environment for studying the drivers of neuroinflammation by decoupling the innate and systemic immune systems, while conserving an endogenous extracellular matrix and structural and functional network complexity. We created a three-dimensional in vitro model of the DTI by seeding primary cortical cells around microwires. Live imaging of both dye and AAV-mediated functional, structural, and lipid peroxidation fluorescence was employed to characterize the neuroinflammatory response. MAIN RESULTS Live imaging of microtissues over time revealed independent innate neuroinflammation, marked by increased OS, decreased neuronal density, and increased functional connectivity. We demonstrated the use of this model for therapeutic screening by directly applying drugs to neural tissue, bypassing low bioavailability through the in vivo blood brain barrier. As there is growing interest in long-acting antioxidant therapies, we tested efficacy of "perpetual" antioxidant ceria nanoparticles, which reduced OS, increased neuronal density, and protected functional connectivity. SIGNIFICANCE Our 3D in vitro model of the device-tissue interface exhibited symptoms of OS-mediated innate neuroinflammation, indicating a significant local immune response to devices. The dysregulation of functional connectivity of microcircuits surround implants suggests the presence of an observer effect, in which the process of recording neural activity may fundamentally change the neural signal. Finally, the demonstration of antioxidant ceria nanoparticle treatment exhibited substantial promise as a neuroprotective and anti-inflammatory treatment strategy.
Collapse
Affiliation(s)
- Elaina Atherton
- School of Engineering, Brown University, 182 Hope Street, Providence, RI 02912, USA, Providence, Rhode Island, 02912, UNITED STATES
| | - Yue Hu
- Department of Chemistry, Brown University, 182 Hope Street, Providence, RI 02912, USA, Providence, Rhode Island, 02912, UNITED STATES
| | - Sophie Brown
- School of Engineering, Brown University, 182 Hope Street, Providence, RI 02912, USA, Providence, Rhode Island, 02912, UNITED STATES
| | - Emily Papiez
- School of Engineering, Brown University, 182 Hope Street, Providence, RI 02912, USA, Providence, Rhode Island, 02912, UNITED STATES
| | - Vivian Ling
- Department of Chemistry, Brown University, 182 Hope Street, Providence, RI 02912, USA, Providence, Rhode Island, 02912, UNITED STATES
| | - Vicki Colvin
- Department of Chemistry, Brown University, 182 Hope Street, Providence, RI 02912, USA, Providence, Rhode Island, 02912, UNITED STATES
| | - David Borton
- School of Engineering, Brown University, 182 Hope Street, Providence, RI 02912, USA, Providence, Rhode Island, 02912, UNITED STATES
| |
Collapse
|
9
|
Palacio-Castañeda V, Velthuijs N, Le Gac S, Verdurmen WPR. Oxygen control: the often overlooked but essential piece to create better in vitro systems. LAB ON A CHIP 2022; 22:1068-1092. [PMID: 35084420 DOI: 10.1039/d1lc00603g] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Variations in oxygen levels play key roles in numerous physiological and pathological processes, but are often not properly controlled in in vitro models, introducing a significant bias in experimental outcomes. Recent developments in microfluidic technology have introduced a paradigm shift by providing new opportunities to better mimic physiological and pathological conditions, which is achieved by both regulating and monitoring oxygen levels at the micrometre scale in miniaturized devices. In this review, we first introduce the nature and relevance of oxygen-dependent pathways in both physiological and pathological contexts. Subsequently, we discuss strategies to control oxygen in microfluidic devices, distinguishing between engineering approaches that operate at the device level during its fabrication and chemical approaches that involve the active perfusion of fluids oxygenated at a precise level or supplemented with oxygen-producing or oxygen-scavenging materials. In addition, we discuss readout approaches for monitoring oxygen levels at the cellular and tissue levels, focusing on electrochemical and optical detection schemes for high-resolution measurements directly on-chip. An overview of different applications in which microfluidic devices have been utilized to answer biological research questions is then provided. In the final section, we provide our vision for further technological refinements of oxygen-controlling devices and discuss how these devices can be employed to generate new fundamental insights regarding key scientific problems that call for emulating oxygen levels as encountered in vivo. We conclude by making the case that ultimately emulating physiological or pathological oxygen levels should become a standard feature in all in vitro cell, tissue, and organ models.
Collapse
Affiliation(s)
- Valentina Palacio-Castañeda
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands.
| | - Niels Velthuijs
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands.
| | - Séverine Le Gac
- Applied Microfluidics for BioEngineering Research, MESA+ Institute for Nanotechnology & TechMed Centre, Organ-on-a-chip Centre, University of Twente, Postbus 217, 7500 AE Enschede, The Netherlands.
| | - Wouter P R Verdurmen
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Medical Center, Geert Grooteplein 28, 6525 GA Nijmegen, The Netherlands.
| |
Collapse
|
10
|
Yazdani M. Uncontrolled Oxygen Levels in Cultures of Retinal Pigment Epithelium: Have We Missed the Obvious? Curr Eye Res 2022; 47:651-660. [PMID: 35243933 DOI: 10.1080/02713683.2022.2050264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Retinal pigment epithelium (RPE) is the outermost layer of retina located between the photoreceptor cells and the choroid. This highly-polarized monolayer provides critical support for the functioning of the other parts of the retina, especially photoreceptors. Methods of culturing RPE have been under development since its establishment in 1920s. Despite considering various factors, oxygen (O2) levels in RPE microenvironments during culture preparation and experimental procedure have been overlooked. O2 is a crucial parameter in the cultures, and therefore, maintaining RPE cells at O2 levels different from their native environment (70-90 mm Hg of O2) could have unintended consequences. Owing to the importance of the topic, lack of sufficient discussion in the literature and to encourage future research, this paper will focus on uncontrolled O2 level in cultures of RPE cells.
Collapse
Affiliation(s)
- Mazyar Yazdani
- Department of Medical Biochemistry, Oslo University Hospital, Rikshospitalet, 0027 Oslo, Norway
| |
Collapse
|
11
|
Martens A, de Buhr N, Ishikawa H, Schroten H, von Köckritz-Blickwede M. Characterization of Oxygen Levels in an Uninfected and Infected Human Blood-Cerebrospinal-Fluid-Barrier Model. Cells 2022; 11:cells11010151. [PMID: 35011713 PMCID: PMC8750020 DOI: 10.3390/cells11010151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 12/23/2021] [Accepted: 12/30/2021] [Indexed: 02/07/2023] Open
Abstract
The host–pathogen interaction during meningitis can be investigated with blood-cerebrospinal-fluid-barrier (BCSFB) cell culture models. They are commonly handled under atmospheric oxygen conditions (19–21% O2), although the physiological oxygen conditions are significantly lower in cerebrospinal fluid (CSF) (7–8% O2). We aimed to characterize oxygen levels in a Streptococcus (S.) suis-infected BCSFB model with transmigrating neutrophils. A BCSFB model with human choroid plexus epithelial cells growing on transwell-filters was used. The upper “blood”-compartment was infected and blood-derived neutrophils were added. S. suis and neutrophils transmigrated through the BCSFB into the “CSF”-compartment. Here, oxygen and pH values were determined with the non-invasive SensorDish® reader. Slight orbital shaking improved the luminescence-based measurement technique for detecting free oxygen. In the non-infected BCSFB model, an oxygen value of 7% O2 was determined. However, with S. suis and transmigrating neutrophils, the oxygen value significantly decreased to 2% O2. The pH level decreased slightly in all groups. In conclusion, we characterized oxygen levels in the BCSFB model and demonstrated the oxygen consumption by cells and bacteria. Oxygen values in the non-infected BCSFB model are comparable to in vivo values determined in pigs in the CSF. Infection and transmigrating neutrophils decrease the oxygen value to lower values.
Collapse
Affiliation(s)
- Alexander Martens
- Department of Biochemistry, University of Veterinary Medicine Hannover, 30559 Hannover, Germany;
- Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, 30559 Hannover, Germany
| | - Nicole de Buhr
- Department of Biochemistry, University of Veterinary Medicine Hannover, 30559 Hannover, Germany;
- Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, 30559 Hannover, Germany
- Correspondence: (N.d.B.); (M.v.K.-B.); Tel.: +49-511-953-6119 (N.d.B.)
| | - Hiroshi Ishikawa
- Laboratory of Clinical Regenerative Medicine, Department of Neurosurgery, University of Tsukuba, Tsukuba-City, Inaraki 305-8575, Japan;
| | - Horst Schroten
- Department of Pediatrics, Pediatric Infectious Diseases, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany;
| | - Maren von Köckritz-Blickwede
- Department of Biochemistry, University of Veterinary Medicine Hannover, 30559 Hannover, Germany;
- Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, 30559 Hannover, Germany
- Correspondence: (N.d.B.); (M.v.K.-B.); Tel.: +49-511-953-6119 (N.d.B.)
| |
Collapse
|
12
|
Luo Y, Lu H, Peng D, Ruan X, Chen YE, Guo Y. Liver-humanized mice: A translational strategy to study metabolic disorders. J Cell Physiol 2022; 237:489-506. [PMID: 34661916 PMCID: PMC9126562 DOI: 10.1002/jcp.30610] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 09/07/2021] [Accepted: 09/11/2021] [Indexed: 01/03/2023]
Abstract
The liver is the metabolic core of the whole body. Tools commonly used to study the human liver metabolism include hepatocyte cell lines, primary human hepatocytes, and pluripotent stem cells-derived hepatocytes in vitro, and liver genetically humanized mouse model in vivo. However, none of these systems can mimic the human liver in physiological and pathological states satisfactorily. Liver-humanized mice, which are established by reconstituting mouse liver with human hepatocytes, have emerged as an attractive animal model to study drug metabolism and evaluate the therapeutic effect in "human liver" in vivo because the humanized livers greatly replicate enzymatic features of human hepatocytes. The application of liver-humanized mice in studying metabolic disorders is relatively less common due to the largely uncertain replication of metabolic profiles compared to humans. Here, we summarize the metabolic characteristics and current application of liver-humanized mouse models in metabolic disorders that have been reported in the literature, trying to evaluate the pros and cons of using liver-humanized mice as novel mouse models to study metabolic disorders.
Collapse
Affiliation(s)
- Yonghong Luo
- Department of Internal Medicine, Cardiovascular Center, University of Michigan Medical Center, Ann Arbor, Michigan, USA.,Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| | - Haocheng Lu
- Department of Internal Medicine, Cardiovascular Center, University of Michigan Medical Center, Ann Arbor, Michigan, USA
| | - Daoquan Peng
- Department of Cardiovascular Medicine, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| | - Xiangbo Ruan
- Division of Endocrinology, Diabetes and Metabolism, Johns Hopkins School of Medicine, Johns Hopkins All Children’s Hospital, St. Petersburg, FL 33701, USA
| | - Y. Eugene Chen
- Department of Internal Medicine, Cardiovascular Center, University of Michigan Medical Center, Ann Arbor, Michigan, USA.,Center for Advanced Models and Translational Sciences and Therapeutics, University of Michigan, Ann Arbor, MI 48109, USA.,Address correspondence to: Yanhong Guo, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, MI 48109, Phone: 734-764-1405, . Or Y. Eugene Chen, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, MI 48109, USA. Phone: 734-936-9548,
| | - Yanhong Guo
- Department of Internal Medicine, Cardiovascular Center, University of Michigan Medical Center, Ann Arbor, Michigan, USA.,Address correspondence to: Yanhong Guo, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, MI 48109, Phone: 734-764-1405, . Or Y. Eugene Chen, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, MI 48109, USA. Phone: 734-936-9548,
| |
Collapse
|
13
|
Maoz BM. Brain-on-a-Chip: Characterizing the next generation of advanced in vitro platforms for modeling the central nervous system. APL Bioeng 2021; 5:030902. [PMID: 34368601 PMCID: PMC8325567 DOI: 10.1063/5.0055812] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 07/19/2021] [Indexed: 02/07/2023] Open
Abstract
The complexity of the human brain creates significant, almost insurmountable challenges for neurological drug development. Advanced in vitro platforms are increasingly enabling researchers to overcome these challenges, by mimicking key features of the brain's composition and functionality. Many of these platforms are called "Brains-on-a-Chip"-a term that was originally used to refer to microfluidics-based systems containing miniature engineered tissues, but that has since expanded to describe a vast range of in vitro central nervous system (CNS) modeling approaches. This Perspective seeks to refine the definition of a Brain-on-a-Chip for the next generation of in vitro platforms, identifying criteria that determine which systems should qualify. These criteria reflect the extent to which a given platform overcomes the challenges unique to in vitro CNS modeling (e.g., recapitulation of the brain's microenvironment; inclusion of critical subunits, such as the blood-brain barrier) and thereby provides meaningful added value over conventional cell culture systems. The paper further outlines practical considerations for the development and implementation of Brain-on-a-Chip platforms and concludes with a vision for where these technologies may be heading.
Collapse
Affiliation(s)
- Ben M. Maoz
- Author to whom correspondence should be addressed:
| |
Collapse
|
14
|
Duggan MR, Mohseni Ahooyi T, Parikh V, Khalili K. Neuromodulation of BAG co-chaperones by HIV-1 viral proteins and H 2O 2: implications for HIV-associated neurological disorders. Cell Death Discov 2021; 7:60. [PMID: 33771978 PMCID: PMC7997901 DOI: 10.1038/s41420-021-00424-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 01/04/2021] [Accepted: 01/30/2021] [Indexed: 11/08/2022] Open
Abstract
Despite increasing numbers of aged individuals living with HIV, the mechanisms underlying HIV-associated neurological disorders (HANDs) remain elusive. As HIV-1 pathogenesis and aging are characterized by oxidative stress as well as altered protein quality control (PQC), reactive oxygen species (ROS) themselves might constitute a molecular mediator of neuronal PQC by modulating BCL-2 associated athanogene (BAG) family members. Present results reveal H2O2 replicated and exacerbated a reduction in neuronal BAG3 induced by the expression of HIV-1 viral proteins (i.e., Tat and Nef), while also causing an upregulation of BAG1. Such a reciprocal regulation of BAG3 and BAG1 levels was also indicated in two animal models of HIV, the doxycycline-inducible Tat (iTat) and the Tg26 mouse. Inhibiting oxidative stress via antioxidants in primary culture was capable of partially preserving neuronal BAG3 levels as well as electrophysiological functioning otherwise altered by HIV-1 viral proteins. Current findings indicate HIV-1 viral proteins and H2O2 may mediate neuronal PQC by exerting synergistic effects on complementary BAG family members, and suggest novel therapeutic targets for the aging HIV-1 population.
Collapse
Affiliation(s)
- Michael R Duggan
- Department of Neuroscience, Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, 7th Floor, Philadelphia, PA, 19140, USA
- Department of Psychology, College of Liberal Arts at Temple University, 1701 N 13th Street, 9th Floor, Philadelphia, PA, 19122, USA
| | - Taha Mohseni Ahooyi
- Department of Neuroscience, Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, 7th Floor, Philadelphia, PA, 19140, USA
| | - Vinay Parikh
- Department of Psychology, College of Liberal Arts at Temple University, 1701 N 13th Street, 9th Floor, Philadelphia, PA, 19122, USA
| | - Kamel Khalili
- Department of Neuroscience, Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, 7th Floor, Philadelphia, PA, 19140, USA.
| |
Collapse
|
15
|
Trotman-Lucas M, Gibson CL. A review of experimental models of focal cerebral ischemia focusing on the middle cerebral artery occlusion model. F1000Res 2021; 10:242. [PMID: 34046164 PMCID: PMC8127011 DOI: 10.12688/f1000research.51752.2] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/21/2021] [Indexed: 12/14/2022] Open
Abstract
Cerebral ischemic stroke is a leading cause of death and disability, but current pharmacological therapies are limited in their utility and effectiveness.
In vitro and
in vivo models of ischemic stroke have been developed which allow us to further elucidate the pathophysiological mechanisms of injury and investigate potential drug targets.
In vitro models permit mechanistic investigation of the biochemical and molecular mechanisms of injury but are reductionist and do not mimic the complexity of clinical stroke.
In vivo models of ischemic stroke directly replicate the reduction in blood flow and the resulting impact on nervous tissue. The most frequently used
in vivo model of ischemic stroke is the intraluminal suture middle cerebral artery occlusion (iMCAO) model, which has been fundamental in revealing various aspects of stroke pathology. However, the iMCAO model produces lesion volumes with large standard deviations even though rigid surgical and data collection protocols are followed. There is a need to refine the MCAO model to reduce variability in the standard outcome measure of lesion volume. The typical approach to produce vessel occlusion is to induce an obstruction at the origin of the middle cerebral artery and reperfusion is reliant on the Circle of Willis (CoW). However, in rodents the CoW is anatomically highly variable which could account for variations in lesion volume. Thus, we developed a refined approach whereby reliance on the CoW for reperfusion was removed. This approach improved reperfusion to the ischemic hemisphere, reduced variability in lesion volume by 30%, and reduced group sizes required to determine an effective treatment response by almost 40%. This refinement involves a methodological adaptation of the original surgical approach which we have shared with the scientific community via publication of a visualised methods article and providing hands-on training to other experimental stroke researchers.
Collapse
Affiliation(s)
| | - Claire L Gibson
- School of Psychology, University of Nottingham, Nottingham, NG7 2UH, UK
| |
Collapse
|
16
|
Holloway PM, Willaime-Morawek S, Siow R, Barber M, Owens RM, Sharma AD, Rowan W, Hill E, Zagnoni M. Advances in microfluidic in vitro systems for neurological disease modeling. J Neurosci Res 2021; 99:1276-1307. [PMID: 33583054 DOI: 10.1002/jnr.24794] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 11/21/2020] [Accepted: 12/19/2020] [Indexed: 12/19/2022]
Abstract
Neurological disorders are the leading cause of disability and the second largest cause of death worldwide. Despite significant research efforts, neurology remains one of the most failure-prone areas of drug development. The complexity of the human brain, boundaries to examining the brain directly in vivo, and the significant evolutionary gap between animal models and humans, all serve to hamper translational success. Recent advances in microfluidic in vitro models have provided new opportunities to study human cells with enhanced physiological relevance. The ability to precisely micro-engineer cell-scale architecture, tailoring form and function, has allowed for detailed dissection of cell biology using microphysiological systems (MPS) of varying complexities from single cell systems to "Organ-on-chip" models. Simplified neuronal networks have allowed for unique insights into neuronal transport and neurogenesis, while more complex 3D heterotypic cellular models such as neurovascular unit mimetics and "Organ-on-chip" systems have enabled new understanding of metabolic coupling and blood-brain barrier transport. These systems are now being developed beyond MPS toward disease specific micro-pathophysiological systems, moving from "Organ-on-chip" to "Disease-on-chip." This review gives an outline of current state of the art in microfluidic technologies for neurological disease research, discussing the challenges and limitations while highlighting the benefits and potential of integrating technologies. We provide examples of where such toolsets have enabled novel insights and how these technologies may empower future investigation into neurological diseases.
Collapse
Affiliation(s)
- Paul M Holloway
- Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | | | - Richard Siow
- King's British Heart Foundation Centre of Research Excellence, School of Cardiovascular Medicine & Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - Melissa Barber
- King's British Heart Foundation Centre of Research Excellence, School of Cardiovascular Medicine & Sciences, Faculty of Life Sciences & Medicine, King's College London, London, UK
| | - Róisín M Owens
- Department Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, UK
| | - Anup D Sharma
- New Orleans BioInnovation Center, AxoSim Inc., New Orleans, LA, USA
| | - Wendy Rowan
- Novel Human Genetics Research Unit, GSK R&D, Stevenage, UK
| | - Eric Hill
- School of Life and Health sciences, Aston University, Birmingham, UK
| | - Michele Zagnoni
- Electronic and Electrical Engineering, University of Strathclyde, Glasgow, UK
| |
Collapse
|
17
|
Cognitive Effects of a Ketogenic Diet on Neurocognitive Impairment in Adults Aging With HIV: A Pilot Study. J Assoc Nurses AIDS Care 2020; 31:312-324. [PMID: 31725105 PMCID: PMC7883774 DOI: 10.1097/jnc.0000000000000110] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We assessed a ketogenic diet (KD) intervention protocol and the cognitive effects of KD in older adults with HIV-associated neurocognitive impairment. Adults older than 50 years and living with HIV and mild-to-moderate neurocognitive impairment were randomized to either a KD or a patient-choice diet for 12 weeks followed by a 6-week washout period. A neurocognitive battery was administered at baseline, Week 12, and Week 18. Paired t tests compared groups at baseline, and multivariate analyses of covariance were used to assess between-group differences on primary outcome variables at Weeks 12 and 18. We enrolled 17 participants, and 14 completed the study. No between-group baseline differences were noted. The KD group demonstrated improved executive function and speed of processing at Week 12, which were negated after participants resumed their usual diets. Our study supports the potential efficacy of a KD for the treatment of HIV-associated neurocognitive impairment.
Collapse
|
18
|
Andjelkovic AV, Stamatovic SM, Phillips CM, Martinez-Revollar G, Keep RF. Modeling blood-brain barrier pathology in cerebrovascular disease in vitro: current and future paradigms. Fluids Barriers CNS 2020; 17:44. [PMID: 32677965 PMCID: PMC7367394 DOI: 10.1186/s12987-020-00202-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 06/15/2020] [Indexed: 12/16/2022] Open
Abstract
The complexity of the blood–brain barrier (BBB) and neurovascular unit (NVU) was and still is a challenge to bridge. A highly selective, restrictive and dynamic barrier, formed at the interface of blood and brain, the BBB is a “gatekeeper” and guardian of brain homeostasis and it also acts as a “sensor” of pathological events in blood and brain. The majority of brain and cerebrovascular pathologies are associated with BBB dysfunction, where changes at the BBB can lead to or support disease development. Thus, an ultimate goal of BBB research is to develop competent and highly translational models to understand mechanisms of BBB/NVU pathology and enable discovery and development of therapeutic strategies to improve vascular health and for the efficient delivery of drugs. This review article focuses on the progress being made to model BBB injury in cerebrovascular diseases in vitro.
Collapse
Affiliation(s)
- Anuska V Andjelkovic
- Department of Pathology, University of Michigan Medical School, 7520 MSRB I, 1150 West Medical Center Dr, Ann Arbor, MI, 48109-5602, USA.
| | - Svetlana M Stamatovic
- Department of Pathology, University of Michigan Medical School, 7520 MSRB I, 1150 West Medical Center Dr, Ann Arbor, MI, 48109-5602, USA
| | - Chelsea M Phillips
- Graduate Program in Neuroscience, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Gabriela Martinez-Revollar
- Department of Pathology, University of Michigan Medical School, 7520 MSRB I, 1150 West Medical Center Dr, Ann Arbor, MI, 48109-5602, USA
| | - Richard F Keep
- Department of Neurosurgery, University of Michigan Medical School, Ann Arbor, MI, USA.,Department of Molecular Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA
| |
Collapse
|
19
|
Gojanovich GS, Shikuma CM, Milne C, Libutti DE, Chow DC, Gerschenson M. Subcutaneous Adipocyte Adenosine Triphosphate Levels in HIV Infected Patients. AIDS Res Hum Retroviruses 2020; 36:75-82. [PMID: 31407586 DOI: 10.1089/aid.2019.0121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Lipoatrophy, or fat wasting, remains a syndrome plaguing HIV+ patients receiving antiretroviral (ARV) therapy. Both HIV infection per se and certain ARV are associated with lowered adipose tissue mitochondrial deoxyribonucleic acid (mtDNA) and mitochondrial ribonucleic acid (mtRNA) levels, but effects on adenosine triphosphate (ATP) production are unclear. We hypothesized that such alterations would accompany lowering of ATP levels in fat of HIV+ patients and would be worse in those displaying lipoatrophy. Gluteal-fold, subcutaneous adipose tissue was obtained from HIV seronegative control patients, from HIV+ ARV-naive patients, and those on ARV with or without lipoatrophy. Cellular ATP was measured in isolated adipocytes and preadipocyte fraction cells by bioluminescence. mtDNA copies/cell and oxidative phosphorylation (OXPHOS) mtRNA transcripts were evaluated by quantitative polymerase chain reactions. ATP levels were consistently higher in preadipocyte fraction cells than adipocytes, but values strongly correlated with each other (r = 0.66, p < .001). ATP levels in adipocytes were higher in both ARV-naive and nonlipoatrophic HIV+ patients compared to seronegative controls, but significantly lower in adipocytes and preadipocytes of lipoatrophic versus other HIV+ patients. Fat mtDNA copies/cell and OXPHOS mtRNA transcripts were lower in lipoatrophic patient samples compared to HIV seronegative. The ratio of specific OXPHOS transcripts to each other was significantly higher in nonlipoatrophic patients versus all groups, and this ratio correlated significantly with ATP levels in adipocytes. Thus, HIV infection is associated with an increase in adipose tissue ATP stores. Decreases in adipose mtDNA and OXPHOS mtRNA are found in those with HIV on ARV; however, ATP level is effected only in patients displaying lipoatrophy.
Collapse
Affiliation(s)
- Greg S. Gojanovich
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
| | - Cecilia M. Shikuma
- Department of Medicine, Hawaii Center for AIDS, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
| | - Cris Milne
- Department of Medicine, Hawaii Center for AIDS, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
| | - Daniel E. Libutti
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
| | - Dominic C. Chow
- Department of Medicine, Hawaii Center for AIDS, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
- Department of Pediatrics, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
| | - Mariana Gerschenson
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii
| |
Collapse
|
20
|
Halim AB. Do We have a Satisfactory Cell Viability Assay? Review of the Currently Commercially-Available Assays. Curr Drug Discov Technol 2020; 17:2-22. [PMID: 30251606 DOI: 10.2174/1570163815666180925095433] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 09/13/2018] [Accepted: 09/18/2018] [Indexed: 06/08/2023]
Abstract
Cell-based assays are an important part of the drug discovery process and clinical research. One of the main hurdles is to design sufficiently robust assays with adequate signal to noise parameters while maintaining the inherent physiology of the cells and not interfering with the pharmacology of target being investigated. A plethora of assays that assess cell viability (or cell heath in general) are commercially available and can be classified under different categories according to their concepts and principle of reactions. The assays are valuable tools, however, suffer from a large number of limitations. Some of these limitations can be procedural or operational, but others can be critical as those related to a poor concept or the lack of proof of concept of an assay, e.g. those relying on differential permeability of dyes in-and-out of viable versus compromised cell membranes. While the assays can differentiate between dead and live cells, most, if not all, of them can just assess the relative performance of cells rather than providing a clear distinction between healthy and dying cells. The possible impact of relatively high molecular weight dyes, used in most of the assay, on cell viability has not been addressed. More innovative assays are needed, and until better alternatives are developed, setup of current cell-based studies and data interpretation should be made with the limitations in mind. Negative and positive control should be considered whenever feasible. Also, researchers should use more than one orthogonal method for better assessment of cell health.
Collapse
Affiliation(s)
- Abdel-Baset Halim
- VP Translational Medicine, Biomarkers & Diagnostics, Celldex Therapeutics, 53 Frontage Road, Suite 220, Hampton, NJ 08827-4032, United States
| |
Collapse
|
21
|
Cotto B, Natarajanseenivasan K, Langford D. HIV-1 infection alters energy metabolism in the brain: Contributions to HIV-associated neurocognitive disorders. Prog Neurobiol 2019; 181:101616. [PMID: 31108127 PMCID: PMC6742565 DOI: 10.1016/j.pneurobio.2019.101616] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 04/17/2019] [Accepted: 05/13/2019] [Indexed: 12/17/2022]
Abstract
The brain is particularly sensitive to changes in energy supply. Defects in glucose utilization and mitochondrial dysfunction are hallmarks of nearly all neurodegenerative diseases and are also associated with the cognitive decline that occurs as the brain ages. Chronic neuroinflammation driven by glial activation is commonly implicated as a contributing factor to neurodegeneration and cognitive impairment. Human immunodeficiency virus-1 (HIV-1) disrupts normal brain homeostasis and leads to a spectrum of HIV-associated neurocognitive disorders (HAND). HIV-1 activates stress responses in the brain and triggers a state of chronic neuroinflammation. Growing evidence suggests that inflammatory processes and bioenergetics are interconnected in the propagation of neuronal dysfunction. Clinical studies of people living with HIV and basic research support the notion that HIV-1 creates an environment in the CNS that interrupts normal metabolic processes at the cellular level to collectively alter whole brain metabolism. In this review, we highlight reports of abnormal brain metabolism from clinical studies and animal models of HIV-1. We also describe diverse CNS cell-specific changes in bioenergetics associated with HIV-1. Moreover, we propose that attention should be given to adjunctive therapies that combat sources of metabolic dysfunction as a mean to improve and/or prevent neurocognitive impairments.
Collapse
Affiliation(s)
- Bianca Cotto
- Lewis Katz School of Medicine at Temple University, Department of Neuroscience and Center for Neurovirology, Philadelphia, PA, 19140, USA.
| | - Kalimuthusamy Natarajanseenivasan
- Lewis Katz School of Medicine at Temple University, Department of Neuroscience and Center for Neurovirology, Philadelphia, PA, 19140, USA.
| | - Dianne Langford
- Lewis Katz School of Medicine at Temple University, Department of Neuroscience and Center for Neurovirology, Philadelphia, PA, 19140, USA.
| |
Collapse
|
22
|
Abstract
All four FOXO isoforms have been shown to respond to changes in the cellular redox status of the cell, and regulate the expression of target genes that in turn can modulate the cellular oxidative status. However, the mechanisms involved are still controversial. It is clear though that redox regulation of FOXO factors occurs at different levels. The proteins themselves are redox-sensitive and their capacity to bind their target sites seems to be at least partially dependent on their oxidative status. Importantly, several of the cofactors that are known to regulate FOXO transcriptional activity are also sensitive to changes in the cellular redox status, in particular the deacetylase SirT1 is activated in response to reduced levels of reducing equivalents (increased NAD+/NADH+ ratio) and the coactivator PGC-1α is induced in response to increased cellular oxidative stress. Furthermore, nuclear localization of FOXO factors is also regulated by proteins that, like AKT, are themselves regulated directly or indirectly by the cellular levels of reactive oxygen and nitrogen species. In this technical review, we aim to update the current status of our knowledge of how to handle redox-regulated FOXO factor research in order to better understand FOXO biology.
Collapse
|
23
|
Pomatto LCD, Sun PY, Yu K, Gullapalli S, Bwiza CP, Sisliyan C, Wong S, Zhang H, Forman HJ, Oliver PL, Davies KE, Davies KJA. Limitations to adaptive homeostasis in an hyperoxia-induced model of accelerated ageing. Redox Biol 2019; 24:101194. [PMID: 31022673 PMCID: PMC6479762 DOI: 10.1016/j.redox.2019.101194] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 04/04/2019] [Accepted: 04/08/2019] [Indexed: 12/11/2022] Open
Abstract
The Nrf2 signal transduction pathway plays a major role in adaptive responses to oxidative stress and in maintaining adaptive homeostasis, yet Nrf2 signaling undergoes a significant age-dependent decline that is still poorly understood. We used mouse embryonic fibroblasts (MEFs) cultured under hyperoxic conditions of 40% O2, as a model of accelerated ageing. Hyperoxia increased baseline levels of Nrf2 and multiple transcriptional targets (20S Proteasome, Immunoproteasome, Lon protease, NQO1, and HO-1), but resulted in loss of cellular ability to adapt to signaling levels (1.0 μM) of H2O2. In contrast, MEFs cultured at physiologically relevant conditions of 5% O2 exhibited a transient induction of Nrf2 Phase II target genes and stress-protective enzymes (the Lon protease and OXR1) following H2O2 treatment. Importantly, all of these effects have been seen in older cells and organisms. Levels of Two major Nrf2 inhibitors, Bach1 and c-Myc, were strongly elevated by hyperoxia and appeared to exert a ceiling on Nrf2 signaling. Bach1 and c-Myc also increase during ageing and may thus be the mechanism by which adaptive homeostasis is compromised with age.
Collapse
Affiliation(s)
- Laura C D Pomatto
- Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center, University of Southern California, Los Angeles, CA 90089-0191, USA
| | - Patrick Y Sun
- Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center, University of Southern California, Los Angeles, CA 90089-0191, USA
| | - Kelsi Yu
- Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center, University of Southern California, Los Angeles, CA 90089-0191, USA
| | - Sandhyarani Gullapalli
- Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center, University of Southern California, Los Angeles, CA 90089-0191, USA
| | - Conscience P Bwiza
- Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center, University of Southern California, Los Angeles, CA 90089-0191, USA
| | - Christina Sisliyan
- Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center, University of Southern California, Los Angeles, CA 90089-0191, USA
| | - Sarah Wong
- Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center, University of Southern California, Los Angeles, CA 90089-0191, USA
| | - Hongqiao Zhang
- Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center, University of Southern California, Los Angeles, CA 90089-0191, USA
| | - Henry Jay Forman
- Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center, University of Southern California, Los Angeles, CA 90089-0191, USA
| | - Peter L Oliver
- Oxford Centre for Gene Function, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK; MRC Harwell Institute, Harwell Campus, Didcot, Oxfordshire, OX11 0RD, UK
| | - Kay E Davies
- Oxford Centre for Gene Function, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, OX1 3PT, UK
| | - Kelvin J A Davies
- Leonard Davis School of Gerontology of the Ethel Percy Andrus Gerontology Center, University of Southern California, Los Angeles, CA 90089-0191, USA; Division of Molecular & Computational Biology, Department of Biological Sciences of the Dornsife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, CA 90089-0191, USA; Department of Biochemistry & Molecular Medicine, Keck School of Medicine of USC, University of Southern California, University of Southern California, Los Angeles, CA 90089-0191, USA.
| |
Collapse
|
24
|
Keeley TP, Mann GE. Defining Physiological Normoxia for Improved Translation of Cell Physiology to Animal Models and Humans. Physiol Rev 2019; 99:161-234. [PMID: 30354965 DOI: 10.1152/physrev.00041.2017] [Citation(s) in RCA: 169] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The extensive oxygen gradient between the air we breathe (Po2 ~21 kPa) and its ultimate distribution within mitochondria (as low as ~0.5-1 kPa) is testament to the efforts expended in limiting its inherent toxicity. It has long been recognized that cell culture undertaken under room air conditions falls short of replicating this protection in vitro. Despite this, difficulty in accurately determining the appropriate O2 levels in which to culture cells, coupled with a lack of the technology to replicate and maintain a physiological O2 environment in vitro, has hindered addressing this issue thus far. In this review, we aim to address the current understanding of tissue Po2 distribution in vivo and summarize the attempts made to replicate these conditions in vitro. The state-of-the-art techniques employed to accurately determine O2 levels, as well as the issues associated with reproducing physiological O2 levels in vitro, are also critically reviewed. We aim to provide the framework for researchers to undertake cell culture under O2 levels relevant to specific tissues and organs. We envisage that this review will facilitate a paradigm shift, enabling translation of findings under physiological conditions in vitro to disease pathology and the design of novel therapeutics.
Collapse
Affiliation(s)
- Thomas P Keeley
- King's British Heart Foundation Centre of Research Excellence, School of Cardiovascular Medicine and Sciences, Faculty of Life Sciences and Medicine, King's College London , London , United Kingdom
| | - Giovanni E Mann
- King's British Heart Foundation Centre of Research Excellence, School of Cardiovascular Medicine and Sciences, Faculty of Life Sciences and Medicine, King's College London , London , United Kingdom
| |
Collapse
|
25
|
Abstract
A hypoxic environment can be defined as a region of the body or the whole body that is deprived of oxygen. Hypoxia is a feature of many diseases, such as cardiovascular disease, tissue trauma, stroke, and solid cancers. A loss of oxygen supply usually results in cell death; however, when cells gradually become hypoxic, they may survive and continue to thrive as described for conditions that promote metastatic growth. The role of hypoxia in these pathogenic pathways is therefore of great interest, and understanding the effect of hypoxia in regulating these mechanisms is fundamentally important. This chapter gives an extensive overview of these mechanisms. Moreover, given the challenges posed by tumor hypoxia we describe the current methods to simulate and detect hypoxic conditions followed by a discussion on current and experimental therapies that target hypoxic cells.
Collapse
Affiliation(s)
- Elizabeth Bowler
- College of Medicine and Health, University of Exeter Medical School, Exeter, UK.
| | - Michael R Ladomery
- Faculty Health and Applied Sciences, University of the West of England, Bristol, UK
| |
Collapse
|
26
|
O’Toole SM, Watson DS, Novoselova TV, Romano LEL, King PJ, Bradshaw TY, Thompson CL, Knight MM, Sharp TV, Barnes MR, Srirangalingam U, Drake WM, Chapple JP. Oncometabolite induced primary cilia loss in pheochromocytoma. Endocr Relat Cancer 2019; 26:165-180. [PMID: 30345732 PMCID: PMC6215910 DOI: 10.1530/erc-18-0134] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 09/05/2018] [Indexed: 12/24/2022]
Abstract
Primary cilia are sensory organelles involved in regulation of cellular signaling. Cilia loss is frequently observed in tumors; yet, the responsible mechanisms and consequences for tumorigenesis remain unclear. We demonstrate that cilia structure and function is disrupted in human pheochromocytomas - endocrine tumors of the adrenal medulla. This is concomitant with transcriptional changes within cilia-mediated signaling pathways that are associated with tumorigenesis generally and pheochromocytomas specifically. Importantly, cilia loss was most dramatic in patients with germline mutations in the pseudohypoxia-linked genes SDHx and VHL. Using a pheochromocytoma cell line derived from rat, we show that hypoxia and oncometabolite-induced pseudohypoxia are key drivers of cilia loss and identify that this is dependent on activation of an Aurora-A/HDAC6 cilia resorption pathway. We also show cilia loss drives dramatic transcriptional changes associated with proliferation and tumorigenesis. Our data provide evidence for primary cilia dysfunction contributing to pathogenesis of pheochromocytoma by a hypoxic/pseudohypoxic mechanism and implicates oncometabolites as ciliary regulators. This is important as pheochromocytomas can cause mortality by mechanisms including catecholamine production and malignant transformation, while hypoxia is a general feature of solid tumors. Moreover, pseudohypoxia-induced cilia resorption can be pharmacologically inhibited, suggesting potential for therapeutic intervention.
Collapse
Affiliation(s)
- Samuel M O’Toole
- William Harvey Research InstituteBarts and the London School of Medicine, Queen Mary University of London, London, UK
- Department of EndocrinologySt Bartholomew’s Hospital, Barts Health NHS Trust, London, UK
| | - David S Watson
- William Harvey Research InstituteBarts and the London School of Medicine, Queen Mary University of London, London, UK
| | - Tatiana V Novoselova
- William Harvey Research InstituteBarts and the London School of Medicine, Queen Mary University of London, London, UK
| | - Lisa E L Romano
- William Harvey Research InstituteBarts and the London School of Medicine, Queen Mary University of London, London, UK
| | - Peter J King
- William Harvey Research InstituteBarts and the London School of Medicine, Queen Mary University of London, London, UK
| | - Teisha Y Bradshaw
- William Harvey Research InstituteBarts and the London School of Medicine, Queen Mary University of London, London, UK
| | - Clare L Thompson
- Institute of Bioengineering and School of Engineering and Material SciencesQueen Mary University of London, London, UK
| | - Martin M Knight
- Institute of Bioengineering and School of Engineering and Material SciencesQueen Mary University of London, London, UK
| | - Tyson V Sharp
- Barts Cancer InstituteQueen Mary University of London, London, UK
| | - Michael R Barnes
- William Harvey Research InstituteBarts and the London School of Medicine, Queen Mary University of London, London, UK
| | - Umasuthan Srirangalingam
- William Harvey Research InstituteBarts and the London School of Medicine, Queen Mary University of London, London, UK
- Department of EndocrinologySt Bartholomew’s Hospital, Barts Health NHS Trust, London, UK
- Department of Diabetes and EndocrinologyUniversity College London Hospital, London, UK
| | - William M Drake
- Department of EndocrinologySt Bartholomew’s Hospital, Barts Health NHS Trust, London, UK
| | - J Paul Chapple
- William Harvey Research InstituteBarts and the London School of Medicine, Queen Mary University of London, London, UK
| |
Collapse
|
27
|
Abstract
The brain is the most complex organ of the body, and many pathological processes underlying various brain disorders are poorly understood. Limited accessibility hinders observation of such processes in the in vivo brain, and experimental freedom is often insufficient to enable informative manipulations. In vitro preparations (brain slices or cultures of dissociated neurons) offer much better accessibility and reduced complexity and have yielded valuable new insights into various brain disorders. Both types of preparations have their advantages and limitations with regard to lifespan, preservation of in vivo brain structure, composition of cell types, and the link to behavioral outcome is often unclear in in vitro models. While these limitations hamper general usage of in vitro preparations to study, e.g., brain development, in vitro preparations are very useful to study neuronal and synaptic functioning under pathologic conditions. This chapter addresses several brain disorders, focusing on neuronal and synaptic functioning, as well as network aspects. Recent progress in the fields of brain circulation disorders, excitability disorders, and memory disorders will be discussed, as well as limitations of current in vitro models.
Collapse
|
28
|
Jaber SM, Bordt EA, Bhatt NM, Lewis DM, Gerecht S, Fiskum G, Polster BM. Sex differences in the mitochondrial bioenergetics of astrocytes but not microglia at a physiologically relevant brain oxygen tension. Neurochem Int 2018; 117:82-90. [PMID: 28888963 PMCID: PMC5839942 DOI: 10.1016/j.neuint.2017.09.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 08/14/2017] [Accepted: 09/05/2017] [Indexed: 11/22/2022]
Abstract
Biological sex is thought to influence mitochondrial bioenergetic function. Previous respiration measurements examining brain mitochondrial sex differences were made at atmospheric oxygen using isolated brain mitochondria. Oxygen is 160 mm Hg (21%) in the atmosphere, while the oxygen tension in the brain generally ranges from ∼5 to 45 mm Hg (∼1-6% O2). This study tested the hypothesis that sex and/or brain physiological oxygen tension influence the mitochondrial bioenergetic properties of primary rat cortical astrocytes and microglia. Oxygen consumption was measured with a Seahorse XF24 cell respirometer in an oxygen-controlled environmental chamber. Strikingly, male astrocytes had a higher maximal respiration than female astrocytes when cultured and assayed at 3% O2. Three percent O2 yielded a low physiological dissolved O2 level of ∼1.2% (9.1 mm Hg) at the cell monolayer during culture and 1.2-3.0% O2 during assays. No differences in bioenergetic parameters were observed between male and female astrocytes at 21% O2 (dissolved O2 of ∼19.7%, 150 mm Hg during culture) or between either of these cell populations and female astrocytes at 3% O2. In contrast to astrocytes, microglia showed no sex differences in mitochondrial bioenergetic parameters at either oxygen level, regardless of whether they were non-stimulated or activated to a proinflammatory state. There were also no O2- or sex-dependent differences in proinflammatory TNF-α or IL-1β cytokine secretion measured at 18 h activation. Overall, results reveal an intriguing sex variance in astrocytic maximal respiration that requires additional investigation. Findings also demonstrate that sex differences can be masked by conducting experiments at non-physiological O2.
Collapse
Affiliation(s)
- Sausan M Jaber
- Department of Anesthesiology, and the Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, 685 W. Baltimore ST., MSTF 5-34, Baltimore, MD, 21201, USA; Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 685 W. Baltimore ST., MSTF 5-34, Baltimore, MD, 21201, USA
| | - Evan A Bordt
- Department of Anesthesiology, and the Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, 685 W. Baltimore ST., MSTF 5-34, Baltimore, MD, 21201, USA
| | - Niraj M Bhatt
- Department of Anesthesiology, and the Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, 685 W. Baltimore ST., MSTF 5-34, Baltimore, MD, 21201, USA
| | - Daniel M Lewis
- Department of Chemical and Biomolecular Engineering, Institute for NanoBioTechnology, Johns Hopkins University, 3400 North Charles Street, Shaffer Hall 200C, Baltimore, MD 21218, USA
| | - Sharon Gerecht
- Department of Chemical and Biomolecular Engineering, Institute for NanoBioTechnology, Johns Hopkins University, 3400 North Charles Street, Shaffer Hall 200C, Baltimore, MD 21218, USA; Department of Materials Science and Engineering, Johns Hopkins University, 3400 North Charles Street, Shaffer Hall 200C, Baltimore, MD 21218, USA
| | - Gary Fiskum
- Department of Anesthesiology, and the Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, 685 W. Baltimore ST., MSTF 5-34, Baltimore, MD, 21201, USA; Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 685 W. Baltimore ST., MSTF 5-34, Baltimore, MD, 21201, USA
| | - Brian M Polster
- Department of Anesthesiology, and the Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, 685 W. Baltimore ST., MSTF 5-34, Baltimore, MD, 21201, USA; Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 685 W. Baltimore ST., MSTF 5-34, Baltimore, MD, 21201, USA.
| |
Collapse
|
29
|
Li X, Wu T, Jiang Y, Zhang Z, Han X, Geng W, Ding H, Kang J, Wang Q, Shang H. Plasma metabolic changes in Chinese HIV-infected patients receiving lopinavir/ritonavir based treatment: Implications for HIV precision therapy. Cytokine 2018; 110:204-212. [PMID: 29778008 DOI: 10.1016/j.cyto.2018.05.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 03/30/2018] [Accepted: 05/02/2018] [Indexed: 12/25/2022]
Abstract
OBJECTIVES The goal of this study is to profile the metabolic changes in the plasma of HIV patients receiving lopinavir/ritonavir (LPV/r)-based highly active antiretroviral therapy (HAART) relative to their treatment-naïve phase, aimed to identify precision therapy for HIV for improving prognosis and predicting dyslipidemia caused by LPV/r. METHODS 38 longitudinal plasma samples were collected from 19 HIV-infected patients both before and after antiretroviral therapy, and 18 samples from healthy individuals were used as controls. Untargeted metabolomics profiling of these plasma samples was performed using liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectrometry (GC-MS). RESULTS A total of 331 compounds of known identity were detected among these metabolites, a 67-metabolite signature mainly mapping to tryptophan, histidine, acyl carnitine, ketone bodies and fatty acid metabolism distinguished HIV patients from healthy controls. The levels of 19 out of the 67 altered metabolites including histidine, kynurenine, and 3-hydroxybutyrate (BHBA), recovered after LPV/r-based antiretroviral therapy, and histidine was positively correlated with the presence of CD4 + T lymphocytes. Furthermore, using receiver operating characteristic (ROC) analyses, we discovered that butyrylcarnitine in combination with myristic acid from plasma in treatment-naïve patients could predict dyslipidemia caused by LPV/r with 87% accuracy. CONCLUSIONS Metabolites alterations in treatment-naïve HIV patients may indicate an inflammatory, oxidative state and mitochondrial dysfunction that is permissive for disease progression. Histidine may provide a specific protective function for HIV patients. Besides, elevated fatty acids levels including butyrylcarnitine and myristic acid after infection may indicate patients at risk of suffering from dyslipidemia after LPV/r-based HAART.
Collapse
Affiliation(s)
- Xiaolin Li
- Key Laboratory of AIDS Immunology of National Health and Family Planning Commission, Department of Laboratory Medicine, The First Affiliated Hospital, China Medical University, Shenyang 110001, PR China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, PR China
| | - Tong Wu
- Key Laboratory of AIDS Immunology of National Health and Family Planning Commission, Department of Laboratory Medicine, The First Affiliated Hospital, China Medical University, Shenyang 110001, PR China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, PR China
| | - Yongjun Jiang
- Key Laboratory of AIDS Immunology of National Health and Family Planning Commission, Department of Laboratory Medicine, The First Affiliated Hospital, China Medical University, Shenyang 110001, PR China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, PR China
| | - Zining Zhang
- Key Laboratory of AIDS Immunology of National Health and Family Planning Commission, Department of Laboratory Medicine, The First Affiliated Hospital, China Medical University, Shenyang 110001, PR China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, PR China
| | - Xiaoxu Han
- Key Laboratory of AIDS Immunology of National Health and Family Planning Commission, Department of Laboratory Medicine, The First Affiliated Hospital, China Medical University, Shenyang 110001, PR China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, PR China
| | - Wenqing Geng
- Key Laboratory of AIDS Immunology of National Health and Family Planning Commission, Department of Laboratory Medicine, The First Affiliated Hospital, China Medical University, Shenyang 110001, PR China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, PR China
| | - Haibo Ding
- Key Laboratory of AIDS Immunology of National Health and Family Planning Commission, Department of Laboratory Medicine, The First Affiliated Hospital, China Medical University, Shenyang 110001, PR China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, PR China
| | - Jing Kang
- Key Laboratory of AIDS Immunology of National Health and Family Planning Commission, Department of Laboratory Medicine, The First Affiliated Hospital, China Medical University, Shenyang 110001, PR China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, PR China
| | - Qi Wang
- Key Laboratory of AIDS Immunology of National Health and Family Planning Commission, Department of Laboratory Medicine, The First Affiliated Hospital, China Medical University, Shenyang 110001, PR China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, PR China
| | - Hong Shang
- Key Laboratory of AIDS Immunology of National Health and Family Planning Commission, Department of Laboratory Medicine, The First Affiliated Hospital, China Medical University, Shenyang 110001, PR China; Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Hangzhou, PR China.
| |
Collapse
|
30
|
Hodge CD, Spyracopoulos L, Glover JNM. Ubc13: the Lys63 ubiquitin chain building machine. Oncotarget 2018; 7:64471-64504. [PMID: 27486774 PMCID: PMC5325457 DOI: 10.18632/oncotarget.10948] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 07/19/2016] [Indexed: 12/25/2022] Open
Abstract
Ubc13 is an ubiquitin E2 conjugating enzyme that participates with many different E3 ligases to form lysine 63-linked (Lys63) ubiquitin chains that are critical to signaling in inflammatory and DNA damage response pathways. Recent studies have suggested Ubc13 as a potential therapeutic target for intervention in various human diseases including several different cancers, alleviation of anti-cancer drug resistance, chronic inflammation, and viral infections. Understanding a potential therapeutic target from different angles is important to assess its usefulness and potential pitfalls. Here we present a global review of Ubc13 from its structure, function, and cellular activities, to its natural and chemical inhibition. The aim of this article is to review the literature that directly implicates Ubc13 in a biological function, and to integrate structural and mechanistic insights into the larger role of this critical E2 enzyme. We discuss observations of multiple Ubc13 structures that suggest a novel mechanism for activation of Ubc13 that involves conformational change of the active site loop.
Collapse
Affiliation(s)
- Curtis D Hodge
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Leo Spyracopoulos
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - J N Mark Glover
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|
31
|
Oxygen Concentration and Oxidative Stress Modulate the Influence of Alzheimer's Disease A β1-42 Peptide on Human Cells. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:7567959. [PMID: 29576854 PMCID: PMC5821958 DOI: 10.1155/2018/7567959] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 11/14/2017] [Accepted: 11/21/2017] [Indexed: 12/12/2022]
Abstract
Reactive oxygen species (ROS) generated after exposure to ionizing radiation and toxic peptides, in mitochondrial metabolism and during aging contribute to damage of cell's structural and functional components and can lead to diseases. Monomers and small oligomers of amyloid beta (Aβ) peptide, players in Alzheimer's disease, are recently suggested to be involved in damaging of neurons, instead of extracellular Aβ plaques. We demonstrate that externally applied disaggregated Aβ1–42 peptide interacts preferentially with acidic compartments (lysosomes). We compared standard cell cultivation (21% O2) to more physiological cell cultivation (5% O2). Cells did not exhibit a dramatic increase in ROS and change in glutathione level upon 4 μM Aβ peptide treatment, whereas exposure to 2 Gy X-rays increased ROS and changed glutathione level and ATP concentration. The occurrence of the 4977 bp deletion in mtDNA and significant protein carbonylation were specific effects of IR and more pronounced at 21% O2. An increase in cell death after Aβ peptide treatment or irradiation was unexpectedly restored to the control level or below when both were combined, particularly at 5% O2. Therefore, Aβ peptide at low concentration can trigger neuroprotective mechanisms in cells exposed to radiation. Oxygen concentration is an important modulator of cellular responses to stress.
Collapse
|
32
|
Sánchez-Ramos C, Prieto I, Tierrez A, Laso J, Valdecantos MP, Bartrons R, Roselló-Catafau J, Monsalve M. PGC-1α Downregulation in Steatotic Liver Enhances Ischemia-Reperfusion Injury and Impairs Ischemic Preconditioning. Antioxid Redox Signal 2017; 27:1332-1346. [PMID: 28269997 DOI: 10.1089/ars.2016.6836] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
AIMS Liver steatosis is associated with mitochondrial dysfunction and elevated reactive oxygen species (ROS) levels together with enhanced sensitivity to ischemia-reperfusion (IR) injury and limited response to preconditioning protocols. Here, we sought to determine whether the downregulation in the steatotic liver of peroxisome proliferator-activated receptor γ co-activator 1α (PGC-1α), a master regulator of mitochondrial metabolism and ROS that is known to play a role in liver metabolic control, could be responsible for the sensitivity of the steatotic liver to ischemic damage. RESULTS PGC-1α was induced in normal liver after exposure to an IR protocol, which was concomitant with an increase in the levels of antioxidant proteins. By contrast, its induction was severely blunted in the steatotic liver, resulting in a modest induction of antioxidant proteins. Livers of PGC-1α-/- mice on a chow diet were normal, but they exhibited an enhanced sensitivity to IR injury and also a lack of response to ischemic preconditioning (IPC), a phenotype that recapitulated the features of the steatotic liver in terms of liver damage, although the inflammatory response differed between both models. Utilizing an in vitro model of IPC, we found that PGC-1α expression was downregulated in hepatic cells cultured at 1% O2; whereas it was induced after reoxygenation (3% O2), and it was responsible for the recovery of antioxidant gene expression after the ischemic period. Innovation & Conclusion: PGC-1α plays an important role in the protection against IR injury in the liver, which is likely associated with its capacity to induce antioxidant gene expression. Antioxid. Redox Signal. 27, 1332-1346.
Collapse
Affiliation(s)
| | - Ignacio Prieto
- 1 Instituto de Investigaciones Biomédicas "Alberto Sols" (CSIC-UAM) , Madrid, Spain
| | - Alberto Tierrez
- 2 Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC) , Madrid, Spain
| | - Javier Laso
- 2 Fundación Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC) , Madrid, Spain
| | - M Pilar Valdecantos
- 3 Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERdem) , ISCIII, Madrid, Spain
| | - Ramon Bartrons
- 4 Unitat de Bioquímica i Biologia Molecular, Departament de Ciències Fisiològiques, Campus de Bellvitge, IDIBELL-Universitat de Barcelona , Hospitalet, Spain
| | - Joan Roselló-Catafau
- 5 Experimental Hepatic Ischemia-Reperfusion Unit, Institut d'Investigacions Biomèdiques de Barcelona (CSIC) , Barcelona, Spain
| | - María Monsalve
- 1 Instituto de Investigaciones Biomédicas "Alberto Sols" (CSIC-UAM) , Madrid, Spain
| |
Collapse
|
33
|
McLaughlin JP, Paris JJ, Mintzopoulos D, Hymel KA, Kim JK, Cirino TJ, Gillis TE, Eans SO, Vitaliano GD, Medina JM, Krapf RC, Stacy HM, Kaufman MJ. Conditional Human Immunodeficiency Virus Transactivator of Transcription Protein Expression Induces Depression-like Effects and Oxidative Stress. BIOLOGICAL PSYCHIATRY. COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2017; 2:599-609. [PMID: 29057370 PMCID: PMC5648358 DOI: 10.1016/j.bpsc.2017.04.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
BACKGROUND The prevalence of major depression in those with HIV/AIDS is substantially higher than in the general population. Mechanisms underlying this comorbidity are poorly understood. HIV-transactivator of transcription (Tat) protein, produced and excreted by HIV, could be involved. We determined whether conditional Tat protein expression in mice is sufficient to induce depression-like behaviors and oxidative stress. Further, as oxidative stress is associated with depression, we determined whether decreasing or increasing oxidative stress by administering methylsulfonylmethane (MSM) or diethylmaleate (DEM), respectively, altered depression-like behavior. METHODS GT-tg bigenic mice received intraperitoneal saline or doxycycline (Dox, 25-100 mg/kg/day) to induce Tat expression. G-tg mice, which do not express Tat protein, also received Dox. Depression-like behavior was assessed with the tail suspension test (TST) and the two-bottle saccharin/water consumption task. Reactive oxygen/nitrogen species (ROS/RNS) were assessed ex vivo. Medial frontal cortex (MFC) oxidative stress and temperature were measured in vivo with 9.4-Tesla proton magnetic resonance spectroscopy (MRS). RESULTS Tat expression increased TST immobility time in an exposure-dependent manner and reduced saccharin consumption. MSM decreased immobility time while DEM increased it in saline-treated GT-tg mice. Tat and MSM behavioral effects persisted for 28 days. Tat and DEM increased while MSM decreased ROS/RNS levels. Tat expression increased MFC glutathione levels and temperature. CONCLUSIONS Tat expression induced rapid and enduring depression-like behaviors and oxidative stress. Increasing/decreasing oxidative stress increased/decreased, respectively, depression-like behavior. Thus, Tat produced by HIV may contribute to the high depression prevalence among those with HIV. Further, mitigation of oxidative stress could reduce depression severity.
Collapse
Affiliation(s)
- Jay P. McLaughlin
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL 32610
| | - Jason J. Paris
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL 32610
- Virginia Commonwealth University, Department of Pharmacology & Toxicology, Richmond, VA 23298
| | - Dionyssios Mintzopoulos
- McLean Imaging Center, Department of Psychiatry, McLean Hospital/Harvard Medical School, Belmont, MA 02478
| | - Kristen A. Hymel
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL 32610
| | - Jae K. Kim
- McLean Imaging Center, Department of Psychiatry, McLean Hospital/Harvard Medical School, Belmont, MA 02478
| | - Thomas J. Cirino
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL 32610
| | - Timothy E. Gillis
- McLean Imaging Center, Department of Psychiatry, McLean Hospital/Harvard Medical School, Belmont, MA 02478
| | - Shainnel O. Eans
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL 32610
| | - Gordana D. Vitaliano
- McLean Imaging Center, Department of Psychiatry, McLean Hospital/Harvard Medical School, Belmont, MA 02478
| | - Jessica M. Medina
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL 32610
| | - Richard C. Krapf
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL 32610
| | - Heather M. Stacy
- Department of Pharmacodynamics, College of Pharmacy, University of Florida, Gainesville, FL 32610
| | - Marc J. Kaufman
- McLean Imaging Center, Department of Psychiatry, McLean Hospital/Harvard Medical School, Belmont, MA 02478
| |
Collapse
|
34
|
Keeley TP, Siow RCM, Jacob R, Mann GE. A PP2A-mediated feedback mechanism controls Ca 2+-dependent NO synthesis under physiological oxygen. FASEB J 2017; 31:5172-5183. [PMID: 28760745 PMCID: PMC5690389 DOI: 10.1096/fj.201700211r] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 07/17/2017] [Indexed: 12/20/2022]
Abstract
Intracellular O2 is a key regulator of NO signaling, yet most in vitro studies are conducted in atmospheric O2 levels, hyperoxic with respect to the physiologic milieu. We investigated NO signaling in endothelial cells cultured in physiologic (5%) O2 and stimulated with histamine or shear stress. Culture of cells in 5% O2 (>5 d) decreased histamine- but not shear stress–stimulated endothelial (e)NOS activity. Unlike cells adapted to a hypoxic environment (1% O2), those cultured in 5% O2 still mobilized sufficient Ca2+ to activate AMPK. Enhanced expression and membrane targeting of PP2A-C was observed in 5% O2, resulting in greater interaction with eNOS in response to histamine. Moreover, increased dephosphorylation of eNOS in 5% O2 was Ca2+-sensitive and reversed by okadaic acid or PP2A-C siRNA. The present findings establish that Ca2+ mobilization stimulates both NO synthesis and PP2A-mediated eNOS dephosphorylation, thus constituting a novel negative feedback mechanism regulating eNOS activity not present in response to shear stress. This, coupled with enhanced NO bioavailability, underpins differences in NO signaling induced by inflammatory and physiologic stimuli that are apparent only in physiologic O2 levels. Furthermore, an explicit delineation between physiologic normoxia and genuine hypoxia is defined here, with implications for our understanding of pathophysiological hypoxia.—Keeley, T. P., Siow, R. C. M., Jacob, R., Mann, G. E. A PP2A-mediated feedback mechanism controls Ca2+-dependent NO synthesis under physiological oxygen.
Collapse
Affiliation(s)
- Thomas P Keeley
- Cardiovascular Division, King's British Heart Foundation Centre of Research Excellence, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Richard C M Siow
- Cardiovascular Division, King's British Heart Foundation Centre of Research Excellence, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Ron Jacob
- Cardiovascular Division, King's British Heart Foundation Centre of Research Excellence, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| | - Giovanni E Mann
- Cardiovascular Division, King's British Heart Foundation Centre of Research Excellence, Faculty of Life Sciences and Medicine, King's College London, London, United Kingdom
| |
Collapse
|
35
|
Rozzi SJ, Avdoshina V, Fields JA, Trejo M, Ton HT, Ahern GP, Mocchetti I. Human Immunodeficiency Virus Promotes Mitochondrial Toxicity. Neurotox Res 2017; 32:723-733. [PMID: 28695547 DOI: 10.1007/s12640-017-9776-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 06/15/2017] [Accepted: 06/28/2017] [Indexed: 01/09/2023]
Abstract
Combined antiretroviral therapies (cART) have had remarkable success in reducing morbidity and mortality among patients infected with human immunodeficiency virus (HIV). However, mild forms of HIV-associated neurocognitive disorders (HAND), characterized by loss of synapses, remain. cART may maintain an undetectable HIV RNA load but does not eliminate the expression of viral proteins such as trans-activator of transcription (Tat) and the envelope glycoprotein gp120 in the brain. These two viral proteins are known to promote synaptic simplifications by several mechanisms, including alteration of mitochondrial function and dynamics. In this review, we aim to outline the many targets and pathways used by viral proteins to alter mitochondria dynamics, which contribute to HIV-induced neurotoxicity. A better understanding of these pathways is crucial for the development of adjunct therapies for HAND.
Collapse
Affiliation(s)
- Summer J Rozzi
- Laboratory of Preclinical Neurobiology, Department of Neuroscience, Georgetown University Medical Center, 3970 Reservoir Rd NW, Washington, DC, 20057, USA
| | - Valeria Avdoshina
- Laboratory of Preclinical Neurobiology, Department of Neuroscience, Georgetown University Medical Center, 3970 Reservoir Rd NW, Washington, DC, 20057, USA
| | - Jerel A Fields
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - Margarita Trejo
- Department of Psychiatry, University of California San Diego, La Jolla, CA, USA
| | - Hoai T Ton
- Department of Pharmacology, Georgetown University Medical Center, Washington, DC, 20057, USA
| | - Gerard P Ahern
- Department of Pharmacology, Georgetown University Medical Center, Washington, DC, 20057, USA
| | - Italo Mocchetti
- Laboratory of Preclinical Neurobiology, Department of Neuroscience, Georgetown University Medical Center, 3970 Reservoir Rd NW, Washington, DC, 20057, USA.
| |
Collapse
|
36
|
Effect of different levels of intermittent hypoxia on autophagy of hippocampal neurons. Sleep Breath 2017; 21:791-798. [PMID: 28553681 DOI: 10.1007/s11325-017-1512-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 04/28/2017] [Accepted: 05/15/2017] [Indexed: 10/19/2022]
Abstract
PURPOSE The current study was carried out to assess the effects of different levels of intermittent hypoxia (IH) on autophagy in hippocampal neurons, and explore the extent, frequency and duration of IH for researching on autophagy in hippocampal neurons. METHODS Hippocampal neurons were exposed to different levels of IH. To analyze the oxygen level of neuronal exposure environment, we detected the oxygen concentration in the chamber by O2 analyzer, and monitored the oxygen partial pressure (PO2), carbon dioxide partial pressure (PCO2), and pH in the culture media by blood gas analyzer. After 4-, 8-, and 12-h IH, the morphology and quantity of neurons, as well as the expression of light chain 3 (LC3)-II positive dots were observed by immunofluorescence. The expression of apoptosis marker protein cleaved caspase-3 and autophagy marker protein LC3 were examined by western blotting. RESULTS The oxygen level in the chamber and the neuronal culture media both reached to the values set previously in three models. The level of cleaved caspase-3 and LC3 had no significant changes in IH-1 group. The morphology and quantity had no significant changes, while the levels of cleaved caspase-3 and LC3 were both increased in IH-2 group. The quantity of neurons was reduced significantly, and the chromatin condensed and nuclei fragmented in IH-3 group. CONCLUSIONS The effects of varying degrees of IH on autophagy in hippocampal neurons are different. The IH model, hypoxia phase (1.5% O2, 5% CO2, and balance N2) for 5 min and reoxygenation phase (21% O2, 5% CO2, and balance N2) for 10 min, may be the best condition for researching on autophagy in hippocampal neurons.
Collapse
|
37
|
le Feber J, Erkamp N, van Putten MJAM, Hofmeijer J. Loss and recovery of functional connectivity in cultured cortical networks exposed to hypoxia. J Neurophysiol 2017; 118:394-403. [PMID: 28424292 DOI: 10.1152/jn.00098.2017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 04/18/2017] [Accepted: 04/18/2017] [Indexed: 01/13/2023] Open
Abstract
In the core of a brain infarct, loss of neuronal function is followed by neuronal death within minutes. In an area surrounding the core (penumbra), some perfusion remains. Here, neurons initially remain structurally intact, but massive synaptic failure strongly reduces neural activity. Activity in the penumbra may eventually recover or further deteriorate toward massive cell death. Besides activity recovery, return of brain functioning requires restoration of connectivity. However, low activity has been shown to initiate compensatory mechanisms that affect network connectivity. We investigated the effect of transient hypoxia and compensatory mechanisms on activity and functional connectivity using cultured cortical networks on multielectrode arrays. Networks were exposed to hypoxia of controlled depth (10-90% of normoxia) and duration (6-48 h). First, we determined how hypoxic depth and duration govern activity recovery. Then, we investigated connectivity changes during and after hypoxic incidents, mild enough for activity to recover. Shortly after hypoxia onset, activity and connectivity decreased. Following 4-6 h of ongoing hypoxia, we observed partial recovery. Only if the hypoxic burden was limited did connectivity show further recovery upon return to normoxia. Partial recovery during hypoxia was dominated by restored baseline connections, rather than newly formed ones. Baseline strengths of surviving (persisting or recovered) and lost connections did not differ nor did baseline activity at their "presynaptic" electrodes. However, "postsynaptic" electrodes of surviving connections were significantly more active during baseline than those of lost connections. This implies that recovery during hypoxia reflects an effective mechanism to restore network activity, which does not necessarily conserve prehypoxia connectivity.NEW & NOTEWORTHY Hypoxia reduced the firing rates of cultured neurons. Depending on hypoxic depth and duration, activity recovered during hypoxia and upon return to normoxia. Recovery (partial) during hypoxia was associated with restored baseline connections rather than newly formed ones. Predominantly, baseline connections with most active postsynaptic electrodes recovered, supporting the notion of effective activity homeostasis. This compensatory mechanism remained effective during ~20 h of hypoxia. Beyond 20 h of compensation, loss of activity and connectivity became irreversible.
Collapse
Affiliation(s)
- Joost le Feber
- Clinical Neurophysiology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, the Netherlands;
| | - Niels Erkamp
- Clinical Neurophysiology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, the Netherlands
| | - Michel J A M van Putten
- Clinical Neurophysiology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, the Netherlands.,Department of Clinical Neurophysiology, Medisch Spectrum Twente, Enschede, the Netherlands; and
| | - Jeannette Hofmeijer
- Clinical Neurophysiology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, the Netherlands.,Department of Neurology, Rijnstate Hospital, Arnhem, the Netherlands
| |
Collapse
|
38
|
Lytovchenko O, Kunji ERS. Expression and putative role of mitochondrial transport proteins in cancer. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:641-654. [PMID: 28342810 DOI: 10.1016/j.bbabio.2017.03.006] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 02/20/2017] [Accepted: 03/21/2017] [Indexed: 02/07/2023]
Abstract
Cancer cells undergo major changes in energy and biosynthetic metabolism. One of them is the Warburg effect, in which pyruvate is used for fermentation rather for oxidative phosphorylation. Another major one is their increased reliance on glutamine, which helps to replenish the pool of Krebs cycle metabolites used for other purposes, such as amino acid or lipid biosynthesis. Mitochondria are central to these alterations, as the biochemical pathways linking these processes run through these organelles. Two membranes, an outer and inner membrane, surround mitochondria, the latter being impermeable to most organic compounds. Therefore, a large number of transport proteins are needed to link the biochemical pathways of the cytosol and mitochondrial matrix. Since the transport steps are relatively slow, it is expected that many of these transport steps are altered when cells become cancerous. In this review, changes in expression and regulation of these transport proteins are discussed as well as the role of the transported substrates. This article is part of a Special Issue entitled Mitochondria in Cancer, edited by Giuseppe Gasparre, Rodrigue Rossignol and Pierre Sonveaux.
Collapse
Affiliation(s)
- Oleksandr Lytovchenko
- Medical Research Council, Mitochondrial Biology Unit, Cambridge Biomedical Campus, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK
| | - Edmund R S Kunji
- Medical Research Council, Mitochondrial Biology Unit, Cambridge Biomedical Campus, Wellcome Trust/MRC Building, Hills Road, Cambridge CB2 0XY, UK.
| |
Collapse
|
39
|
Abstract
About two decades ago, West and coworkers established a model which predicts that metabolic rate follows a three quarter power relationship with the mass of an organism, based on the premise that tissues are supplied nutrients through a fractal distribution network. Quarter power scaling is widely considered a universal law of biology and it is generally accepted that were in-vitro cultures to obey allometric metabolic scaling, they would have more predictive potential and could, for instance, provide a viable substitute for animals in research. This paper outlines a theoretical and computational framework for establishing quarter power scaling in three-dimensional spherical constructs in-vitro, starting where fractal distribution ends. Allometric scaling in non-vascular spherical tissue constructs was assessed using models of Michaelis Menten oxygen consumption and diffusion. The models demonstrate that physiological scaling is maintained when about 5 to 60% of the construct is exposed to oxygen concentrations less than the Michaelis Menten constant, with a significant concentration gradient in the sphere. The results have important implications for the design of downscaled in-vitro systems with physiological relevance.
Collapse
Affiliation(s)
- Arti Ahluwalia
- Department of Information Engineering and Research Center E.Piaggio, University of Pisa, Pisa, Italy
| |
Collapse
|
40
|
Chapin RE, Winton T, Nowland W, Danis N, Kumpf S, Johnson K, Coburn A, Stukenborg JB. Lost in translation: The search for an in vitro screen for spermatogenic toxicity. ACTA ACUST UNITED AC 2016; 107:225-242. [DOI: 10.1002/bdrb.21188] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 11/18/2016] [Accepted: 11/18/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Robert E. Chapin
- Developmental and Reproductive Toxicology Center of Expertise; Pfizer Worldwide R&D (WRD); Groton CT USA
| | - Timothy Winton
- Developmental and Reproductive Toxicology Center of Expertise; Pfizer Worldwide R&D (WRD); Groton CT USA
| | - William Nowland
- Developmental and Reproductive Toxicology Center of Expertise; Pfizer Worldwide R&D (WRD); Groton CT USA
| | - Nichole Danis
- Developmental and Reproductive Toxicology Center of Expertise; Pfizer Worldwide R&D (WRD); Groton CT USA
- Histopathology Laboratory; WRD; Groton CT USA
| | - Steven Kumpf
- Developmental and Reproductive Toxicology Center of Expertise; Pfizer Worldwide R&D (WRD); Groton CT USA
| | - Kjell Johnson
- Developmental and Reproductive Toxicology Center of Expertise; Pfizer Worldwide R&D (WRD); Groton CT USA
- Arbor Analytics; Ann Arbor MI USA
| | - Aleasha Coburn
- Developmental and Reproductive Toxicology Center of Expertise; Pfizer Worldwide R&D (WRD); Groton CT USA
| | - Jan-Bernd Stukenborg
- Department of Women's and Children's Health; Karolinska Institutet; Stockholm Sweden
| |
Collapse
|
41
|
Džinić T, Hartwig S, Lehr S, Dencher NA. Oxygen and differentiation status modulate the effect of X-ray irradiation on physiology and mitochondrial proteome of human neuroblastoma cells. Arch Physiol Biochem 2016; 122:257-265. [PMID: 27615280 DOI: 10.1080/13813455.2016.1218518] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Cytotoxic effects, including oxidative stress, of low linear energy transfer (LET)-ionizing radiation are often underestimated and studies of their mechanisms using cell culture models are widely conducted with cells cultivated at atmospheric oxygen that does not match its physiological levels in body tissues. Also, cell differentiation status plays a role in the outcome of experiments. We compared effects of 2 Gy X-ray irradiation on the physiology and mitochondrial proteome of nondifferentiated and human neuroblastoma (SH-SY5Y) cells treated with retinoic acid cultivated at 21% and 5% O2. Irradiation did not affect the amount of subunits of OxPhos complexes and other non-OxPhos mitochondrial proteins, except for heat shock protein 70, which was increased depending on oxygen level and differentiation status. These two factors were proven to modulate mitochondrial membrane potential and the bioenergetic status of cells. We suggest, moreover, that oxygen plays a role in the differentiation of human SH-SY5Y cells.
Collapse
Affiliation(s)
- Tamara Džinić
- a Physical Biochemistry, Department of Chemistry , Technische Universität Darmstadt , Darmstadt , Germany
| | - Sonja Hartwig
- b Institute of Clinical Biochemistry and Pathobiochemistry, German Diabetes Center at the Heinrich-Heine-University Düsseldorf, Leibniz Center for Diabetes Research , Düsseldorf , Germany , and
- c German Center for Diabetes Research (DZD) , München , Neuherberg , Germany
| | - Stefan Lehr
- b Institute of Clinical Biochemistry and Pathobiochemistry, German Diabetes Center at the Heinrich-Heine-University Düsseldorf, Leibniz Center for Diabetes Research , Düsseldorf , Germany , and
- c German Center for Diabetes Research (DZD) , München , Neuherberg , Germany
| | - Norbert A Dencher
- a Physical Biochemistry, Department of Chemistry , Technische Universität Darmstadt , Darmstadt , Germany
| |
Collapse
|
42
|
Horvath P, Aulner N, Bickle M, Davies AM, Nery ED, Ebner D, Montoya MC, Östling P, Pietiäinen V, Price LS, Shorte SL, Turcatti G, von Schantz C, Carragher NO. Screening out irrelevant cell-based models of disease. Nat Rev Drug Discov 2016; 15:751-769. [PMID: 27616293 DOI: 10.1038/nrd.2016.175] [Citation(s) in RCA: 322] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The common and persistent failures to translate promising preclinical drug candidates into clinical success highlight the limited effectiveness of disease models currently used in drug discovery. An apparent reluctance to explore and adopt alternative cell- and tissue-based model systems, coupled with a detachment from clinical practice during assay validation, contributes to ineffective translational research. To help address these issues and stimulate debate, here we propose a set of principles to facilitate the definition and development of disease-relevant assays, and we discuss new opportunities for exploiting the latest advances in cell-based assay technologies in drug discovery, including induced pluripotent stem cells, three-dimensional (3D) co-culture and organ-on-a-chip systems, complemented by advances in single-cell imaging and gene editing technologies. Funding to support precompetitive, multidisciplinary collaborations to develop novel preclinical models and cell-based screening technologies could have a key role in improving their clinical relevance, and ultimately increase clinical success rates.
Collapse
Affiliation(s)
- Peter Horvath
- Synthetic and Systems Biology Unit, Biological Research Centre of the Hungarian Academy of Sciences, Szeged H-6726, Hungary; and at the Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki 00290, Finland.,European Cell-Based Assays Interest Group
| | - Nathalie Aulner
- Imagopole-Citech, Institut Pasteur, Paris 75015, France.,European Cell-Based Assays Interest Group
| | - Marc Bickle
- Technology Development Studio, Max Planck Institute of Molecular Cell Biology and Genetics, Dresden 01307, Germany.,European Cell-Based Assays Interest Group
| | - Anthony M Davies
- Translational Cell Imaging Queensland (TCIQ), Institute of Health Biomedical Innovation, Queensland University of Technology, Brisbane 4102 QLD, Australia; and The Irish National Centre for High Content Screening and Analysis, Trinity Translational Medicine Institute, Trinity College Dublin, Phase 3 Trinity Health Sciences 1.20, St James Hospital, Dublin D8, Republic of Ireland.,European Cell-Based Assays Interest Group
| | - Elaine Del Nery
- Institut Curie, PSL Research University, Department of Translational Research, The Biophenics High-Content Screening Laboratory, Cell and Tissue Imaging Facility (PICT-IBiSA), F-75005, Paris, France.,European Cell-Based Assays Interest Group
| | - Daniel Ebner
- Target Discovery Institute, University of Oxford, Oxford OX3 7FZ, UK.,European Cell-Based Assays Interest Group
| | - Maria C Montoya
- Cellomics Unit, Cell Biology &Physiology Program, Cell &Developmental Biology Area, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid 28029, Spain.,European Cell-Based Assays Interest Group
| | - Päivi Östling
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki 00290, Finland.,Science for Life Laboratory, Department of Oncology and Pathology, Karolinska Institutet, Stockholm 17165, Sweden.,European Cell-Based Assays Interest Group
| | - Vilja Pietiäinen
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki 00290, Finland.,European Cell-Based Assays Interest Group
| | - Leo S Price
- Faculty of Science, Leiden Academic Centre for Drug Research, Toxicology, Universiteit Leiden, The Netherlands; and at OcellO, J.H Oortweg 21, 2333 CH, Leiden, The Netherlands.,European Cell-Based Assays Interest Group
| | - Spencer L Shorte
- Imagopole-Citech, Institut Pasteur, Paris 75015, France.,European Cell-Based Assays Interest Group
| | - Gerardo Turcatti
- Biomolecular Screening Facility, Swiss Federal Institute of Technology (EPFL), Lausanne CH-1015, Switzerland.,European Cell-Based Assays Interest Group
| | - Carina von Schantz
- Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki 00290, Finland.,European Cell-Based Assays Interest Group
| | - Neil O Carragher
- Cancer Research UK Edinburgh Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh EH4 2XR, UK.,European Cell-Based Assays Interest Group
| |
Collapse
|
43
|
Jana A, Crowston BJ, Shewring JR, McKenzie LK, Bryant HE, Botchway SW, Ward AD, Amoroso AJ, Baggaley E, Ward MD. Heteronuclear Ir(III)-Ln(III) Luminescent Complexes: Small-Molecule Probes for Dual Modal Imaging and Oxygen Sensing. Inorg Chem 2016; 55:5623-33. [PMID: 27219675 DOI: 10.1021/acs.inorgchem.6b00702] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Luminescent, mixed metal d-f complexes have the potential to be used for dual (magnetic resonance imaging (MRI) and luminescence) in vivo imaging. Here, we present dinuclear and trinuclear d-f complexes, comprising a rigid framework linking a luminescent Ir center to one (Ir·Ln) or two (Ir·Ln2) lanthanide metal centers (where Ln = Eu(III) and Gd(III), respectively). A range of physical, spectroscopic, and imaging-based properties including relaxivity arising from the Gd(III) units and the occurrence of Ir(III) → Eu(III) photoinduced energy-transfer are presented. The rigidity imposed by the ligand facilitates high relaxivities for the Gd(III) complexes, while the luminescence from the Ir(III) and Eu(III) centers provide luminescence imaging capabilities. Dinuclear (Ir·Ln) complexes performed best in cellular studies, exhibiting good solubility in aqueous solutions, low toxicity after 4 and 18 h, respectively, and punctate lysosomal staining. We also demonstrate the first example of oxygen sensing in fixed cells using the dyad Ir·Gd, via two-photon phosphorescence lifetime imaging (PLIM).
Collapse
Affiliation(s)
- Atanu Jana
- Department of Chemistry, University of Sheffield , Sheffield, S3 7HF, United Kingdom
| | - Bethany J Crowston
- Department of Chemistry, University of Sheffield , Sheffield, S3 7HF, United Kingdom
| | - Jonathan R Shewring
- Department of Chemistry, University of Sheffield , Sheffield, S3 7HF, United Kingdom
| | - Luke K McKenzie
- Department of Chemistry, University of Sheffield , Sheffield, S3 7HF, United Kingdom.,Department of Oncology & Metabolism, University of Sheffield , Sheffield, S10 2RX, United Kingdom
| | - Helen E Bryant
- Department of Oncology & Metabolism, University of Sheffield , Sheffield, S10 2RX, United Kingdom
| | - Stanley W Botchway
- Rutherford Appleton Laboratory, STFC, Research Complex at Harwell, Harwell Science and Innovation Campus , Didcot, OX11 0FA, United Kingdom
| | - Andrew D Ward
- Rutherford Appleton Laboratory, STFC, Research Complex at Harwell, Harwell Science and Innovation Campus , Didcot, OX11 0FA, United Kingdom
| | - Angelo J Amoroso
- School of Chemistry, Cardiff University , Main Building, Park Place, Cardiff CF10 3AT, United Kingdom
| | - Elizabeth Baggaley
- Department of Chemistry, University of Sheffield , Sheffield, S3 7HF, United Kingdom
| | - Michael D Ward
- Department of Chemistry, University of Sheffield , Sheffield, S3 7HF, United Kingdom
| |
Collapse
|
44
|
Villeneuve LM, Purnell PR, Stauch KL, Callen SE, Buch SJ, Fox HS. HIV-1 transgenic rats display mitochondrial abnormalities consistent with abnormal energy generation and distribution. J Neurovirol 2016; 22:564-574. [PMID: 26843384 DOI: 10.1007/s13365-016-0424-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 12/04/2015] [Accepted: 01/12/2016] [Indexed: 02/06/2023]
Abstract
With the advent of the combination antiretroviral therapy era (cART), the development of AIDS has been largely limited in the USA. Unfortunately, despite the development of efficacious treatments, HIV-1-associated neurocognitive disorders (HAND) can still develop, and as many HIV-1 positive individuals age, the prevalence of HAND is likely to rise because HAND manifests in the brain with very low levels of virus. However, the mechanism producing this viral disorder is still debated. Interestingly, HIV-1 infection exposes neurons to proteins including Tat, Nef, and Vpr which can drastically alter mitochondrial properties. Mitochondrial dysfunction has been posited to be a cornerstone of the development of numerous neurodegenerative diseases. Therefore, we investigated mitochondria in an animal model of HAND. Using an HIV-1 transgenic rat model expressing seven of the nine HIV-1 viral proteins, mitochondrial functional and proteomic analysis were performed on a subset of mitochondria that are particularly sensitive to cellular changes, the neuronal synaptic mitochondria. Quantitative mass spectroscopic studies followed by statistical analysis revealed extensive proteome alteration in this model paralleling mitochondrial abnormalities identified in HIV-1 animal models and HIV-1-infected humans. Novel mitochondrial protein changes were discovered in the electron transport chain (ETC), the glycolytic pathways, mitochondrial trafficking proteins, and proteins involved in various energy pathways, and these findings correlated well with the function of the mitochondria as assessed by a mitochondrial coupling and flux assay. By targeting these proteins and proteins upstream in the same pathway, we may be able to limit the development of HAND.
Collapse
Affiliation(s)
- Lance M Villeneuve
- Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, 985800 Nebraska Medical Center-DRC1 3008, Omaha, NE, 68198-5800, USA
| | - Phillip R Purnell
- Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, 985800 Nebraska Medical Center-DRC1 3008, Omaha, NE, 68198-5800, USA
| | - Kelly L Stauch
- Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, 985800 Nebraska Medical Center-DRC1 3008, Omaha, NE, 68198-5800, USA
| | - Shannon E Callen
- Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, 985800 Nebraska Medical Center-DRC1 3008, Omaha, NE, 68198-5800, USA
| | - Shilpa J Buch
- Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, 985800 Nebraska Medical Center-DRC1 3008, Omaha, NE, 68198-5800, USA
| | - Howard S Fox
- Departments of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, 985800 Nebraska Medical Center-DRC1 3008, Omaha, NE, 68198-5800, USA.
| |
Collapse
|
45
|
Kumar A, Dailey LA, Swedrowska M, Siow R, Mann GE, Vizcay-Barrena G, Arno M, Mudway IS, Forbes B. Quantifying the magnitude of the oxygen artefact inherent in culturing airway cells under atmospheric oxygen versus physiological levels. FEBS Lett 2016; 590:258-69. [DOI: 10.1002/1873-3468.12026] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 11/23/2015] [Accepted: 11/24/2015] [Indexed: 12/31/2022]
Affiliation(s)
- Abhinav Kumar
- Institute of Pharmaceutical Science; King's College London; UK
| | - Lea Ann Dailey
- Institute of Pharmaceutical Science; King's College London; UK
| | | | - Richard Siow
- Cardiovascular Division; British Heart Foundation Centre of Research Excellence; King's College London; UK
| | - Giovanni E. Mann
- Cardiovascular Division; British Heart Foundation Centre of Research Excellence; King's College London; UK
| | | | | | - Ian S. Mudway
- MRC-PHE Centre for Environment and Health; King's College London; UK
- NIHR Health Protection Research Unit on Environmental Hazards at King's College London in Partnership with Public Health England; London UK
| | - Ben Forbes
- Institute of Pharmaceutical Science; King's College London; UK
| |
Collapse
|
46
|
Holloway PM, Gavins FNE. Modeling Ischemic Stroke In Vitro: Status Quo and Future Perspectives. Stroke 2016; 47:561-9. [PMID: 26742797 DOI: 10.1161/strokeaha.115.011932] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 12/04/2015] [Indexed: 12/13/2022]
Affiliation(s)
- Paul M Holloway
- From the Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA
| | - Felicity N E Gavins
- From the Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA.
| |
Collapse
|
47
|
Lages YM, Nascimento JM, Lemos GA, Galina A, Castilho LR, Rehen SK. Low oxygen alters mitochondrial function and response to oxidative stress in human neural progenitor cells. PeerJ 2015; 3:e1486. [PMID: 26713239 PMCID: PMC4690376 DOI: 10.7717/peerj.1486] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 11/18/2015] [Indexed: 12/11/2022] Open
Abstract
Oxygen concentration should be carefully regulated in all living tissues, beginning at the early embryonic stages. Unbalances in oxygen regulation can lead to cell death and disease. However, to date, few studies have investigated the consequences of variations in oxygen levels for fetal-like cells. Therefore, in the present work, human neural progenitor cells (NPCs) derived from pluripotent stem cells grown in 3% oxygen (v/v) were compared with NPCs cultured in 21% (v/v) oxygen. Low oxygen concentrations altered the mitochondrial content and oxidative functions of the cells, which led to improved ATP production, while reducing generation of reactive oxygen species (ROS). NPCs cultured in both conditions showed no differences in proliferation and glucose metabolism. Furthermore, antioxidant enzymatic activity was not altered in NPCs cultured in 3% oxygen under normal conditions, however, when exposed to external agents known to induce oxidative stress, greater susceptibility to DNA damage was observed. Our findings indicate that the management of oxygen levels should be considered for in vitro models of neuronal development and drug screening.
Collapse
Affiliation(s)
- Yury M Lages
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro , Rio de Janeiro, RJ , Brazil
| | | | - Gabriela A Lemos
- Institute of Medical Biochemistry Leopoldo De Meis, Federal University of Rio de Janeiro , Rio de Janeiro, RJ , Brazil
| | - Antonio Galina
- Institute of Medical Biochemistry Leopoldo De Meis, Federal University of Rio de Janeiro , Rio de Janeiro, RJ , Brazil
| | - Leda R Castilho
- COPPE, Chemical Engineering Program, Federal University of Rio de Janeiro , Rio de Janeiro, RJ , Brazil
| | - Stevens K Rehen
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro , Rio de Janeiro, RJ , Brazil ; IDOR, D'Or Institute for Research and Education , Rio de Janeiro, RJ , Brazil
| |
Collapse
|
48
|
Babu D, Leclercq G, Goossens V, Remijsen Q, Vandenabeele P, Motterlini R, Lefebvre RA. Antioxidant potential of CORM-A1 and resveratrol during TNF-α/cycloheximide-induced oxidative stress and apoptosis in murine intestinal epithelial MODE-K cells. Toxicol Appl Pharmacol 2015; 288:161-78. [PMID: 26187750 DOI: 10.1016/j.taap.2015.07.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 07/03/2015] [Accepted: 07/07/2015] [Indexed: 12/26/2022]
Abstract
Targeting excessive production of reactive oxygen species (ROS) could be an effective therapeutic strategy to prevent oxidative stress-associated gastrointestinal inflammation. NADPH oxidase (NOX) and mitochondrial complexes (I and II) are the major sources of ROS production contributing to TNF-α/cycloheximide (CHX)-induced apoptosis in the mouse intestinal epithelial cell line, MODE-K. In the current study, the influence of a polyphenolic compound (resveratrol) and a water-soluble carbon monoxide (CO)-releasing molecule (CORM-A1) on the different sources of TNF-α/CHX-induced ROS production in MODE-K cells was assessed. This was compared with H2O2-, rotenone- or antimycin-A-induced ROS-generating systems. Intracellular total ROS, mitochondrial-derived ROS and mitochondrial superoxide anion (O2(-)) production levels were assessed. Additionally, the influence on TNF-α/CHX-induced changes in mitochondrial membrane potential (Ψm) and mitochondrial function was studied. In basal conditions, CORM-A1 did not affect intracellular total or mitochondrial ROS levels, while resveratrol increased intracellular total ROS but reduced mitochondrial ROS production. TNF-α/CHX- and H2O2-mediated increase in intracellular total ROS production was reduced by both resveratrol and CORM-A1, whereas only resveratrol attenuated the increase in mitochondrial ROS triggered by TNF-α/CHX. CORM-A1 decreased antimycin-A-induced mitochondrial O2(-) production without any influence on TNF-α/CHX- and rotenone-induced mitochondrial O2(-) levels, while resveratrol abolished all three effects. Finally, resveratrol greatly reduced and abolished TNF-α/CHX-induced mitochondrial depolarization and mitochondrial dysfunction, while CORM-A1 only mildly affected these parameters. These data indicate that the cytoprotective effect of resveratrol is predominantly due to mitigation of mitochondrial ROS, while CORM-A1 acts solely on NOX-derived ROS to protect MODE-K cells from TNF-α/CHX-induced cell death. This might explain the more pronounced cytoprotective effect of resveratrol.
Collapse
Affiliation(s)
- Dinesh Babu
- Heymans Institute of Pharmacology, Faculty of Medicine and Health Sciences, Ghent University, Belgium.
| | - Georges Leclercq
- Department of Clinical Chemistry, Microbiology and Immunology, Faculty of Medicine and Health Sciences, Ghent University, Belgium
| | - Vera Goossens
- Inflammation Research Center, Molecular Signaling and Cell Death Unit, VIB, Ghent, Belgium; Department of Biomedical Molecular Biology, Molecular Signaling and Cell Death Unit, Ghent University, Ghent, Belgium
| | - Quinten Remijsen
- Inflammation Research Center, Molecular Signaling and Cell Death Unit, VIB, Ghent, Belgium; Department of Biomedical Molecular Biology, Molecular Signaling and Cell Death Unit, Ghent University, Ghent, Belgium
| | - Peter Vandenabeele
- Inflammation Research Center, Molecular Signaling and Cell Death Unit, VIB, Ghent, Belgium; Department of Biomedical Molecular Biology, Molecular Signaling and Cell Death Unit, Ghent University, Ghent, Belgium
| | - Roberto Motterlini
- Inserm U955, Equipe 12 and University Paris-Est Créteil, Faculty of Medicine, F-94000 Créteil, France
| | - Romain A Lefebvre
- Heymans Institute of Pharmacology, Faculty of Medicine and Health Sciences, Ghent University, Belgium
| |
Collapse
|
49
|
Emam M, Thompson-Crispi K, Mallard B. The effect of immunological status, in-vitro treatment and culture time on expression of eleven candidate reference genes in bovine blood mononuclear cells. BMC Immunol 2015; 16:33. [PMID: 26025301 PMCID: PMC4449592 DOI: 10.1186/s12865-015-0099-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 05/20/2015] [Indexed: 01/05/2023] Open
Abstract
Background Technical feasibility of RNA quantification by real time RT-PCR has led to enormous utilization of this method. However, real time PCR results need to be normalized due to the high sensitivity of the method and also to eliminate technical variation. Normalization against a reference gene that is constitutively transcribed and has minimum variation among samples is the ideal method. Nevertheless, many studies have shown that there is no general reference gene(s) with ideal characteristics and candidate reference genes should be tested before being used as a “normalizer” in each study. Methods The current study investigated the effects of previous exposure of the host to experimental test antigens and culturing time on the expression of 11 candidate genes when blood mononuclear cells (BMCs) were cultured and treated in-vitro by hen egg white lysozyme, Candida albicans extract and a mitogen. Mononuclear cells were isolated and cultured from 12 bovine blood samples representing 3 different immunological statuses. The expression of candidate housekeeping genes were measured by real-time RT-PCR at 4 and 24 hours post culture. The expression of candidate genes were first compared between the two time points in untreated samples. Constitutively expressed genes were further tested in linear mixed effects models to examine the effect of previous host exposure and in-vitro treatments. Results Our findings showed that the expression of the most common reference genes, β-actin, and Glyceraldehydes-3-phosphate dehydrogenase (GAPDH), are significantly decreased at 24 hours after culturing BMCs, even without any treatment. The effect of culturing time was also significantly influenced the expression of 18s ribosomal RNA, β2-microglobulin, Tyrosine 3-monooxygenase/tryptophan 5-monoxygenase activation protein, zeta polypeptide (YWHAZ) in BMCs. Only the expression of C-terminal binding protein 1 (CTBP1) and RAD50 among all tested genes were consistent after treatment of cultured BMCs with C. albicans whole yeast extract and Hen Egg White Lysozyme (HEWL), respectively. In addition, expressions of CTBP1, and RAD50 were independent from previous exposure of the host to the antigen. Conclusions The results of this study demonstrated inconsistent expression of commonly used reference genes in untreated cultured BMCs over time. As this condition applies to negative controls in real time RT-PCR study designs, normalization against these genes can largely deceive the outcome, especially in kinetic studies. Moreover, the potential effects of immunological memory on the expression of reference genes should be considered if BMCs are collected from different individuals under different environmental conditions and if these cells are treated in-vitro by an antigen.
Collapse
Affiliation(s)
- Mehdi Emam
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada.
| | - Kathleen Thompson-Crispi
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada. .,Center for Genetic Improvement of Livestock, University of Guelph, Guelph, ON, Canada.
| | - Bonnie Mallard
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada. .,Center for Genetic Improvement of Livestock, University of Guelph, Guelph, ON, Canada.
| |
Collapse
|
50
|
Abstract
Evidence is presented that the rate and equilibrium constants in mitochondrial oxidative phosphorylation set and maintain metabolic homeostasis in eukaryotic cells. These internal constants determine the energy state ([ATP]/[ADP][Pi]), and the energy state maintains homeostasis through a bidirectional sensory/signaling control network that reaches every aspect of cellular metabolism. The energy state is maintained with high precision (to ∼1 part in 10(10)), and the control system can respond to transient changes in energy demand (ATP utilization) of more than 100 times the resting rate. Epigenetic and environmental factors are able to "fine-tune" the programmed set point over a narrow range to meet the special needs associated with cell differentiation and chronic changes in metabolic requirements. The result is robust across-platform control of metabolism, which is essential to cellular differentiation and the evolution of complex organisms. A model of oxidative phosphorylation is presented, for which the steady-state rate expression has been derived and computer programmed. The behavior of oxidative phosphorylation predicted by the model is shown to fit the experimental data available for isolated mitochondria as well as for cells and tissues. This includes measurements from several different mammalian tissues as well as from insect flight muscle and plants. The respiratory chain and oxidative phosphorylation is remarkably similar for all higher plants and animals. This is consistent with the efficient synthesis of ATP and precise control of metabolic homeostasis provided by oxidative phosphorylation being a key to cellular differentiation and the evolution of structures with specialized function.
Collapse
Affiliation(s)
- David F Wilson
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| |
Collapse
|