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Yao M, Walker G, Gamcsik MP. Assessing MTT and sulforhodamine B cell proliferation assays under multiple oxygen environments. Cytotechnology 2023; 75:381-390. [PMID: 37655276 PMCID: PMC10465423 DOI: 10.1007/s10616-023-00584-0] [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: 09/20/2022] [Accepted: 06/20/2023] [Indexed: 09/02/2023] Open
Abstract
Cell proliferation can be measured directly by counting cells or indirectly using assays that quantitate total protein or metabolic activity. However, for comparing cell proliferation under varying oxygen conditions it is not clear that these assays are appropriate surrogates for cell counting as cell metabolism and protein synthesis may vary under different oxygen environments. We used permeable bottom tissue culture ware to compare proliferation assays as a function of static oxygen concentrations under oxygen partial pressure (pO2) levels ranging from 2 to 139 mmHg. Cell proliferation was measured by cell counting and compared to surrogate methods measuring cell metabolism (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, MTT) and total protein (sulforhodamine B) assays under these different environments in Caco-2, MCF-7, MCF-10A and PANC-1 human cell lines. We found that the MTT readings do not correlate with cell number for the Caco-2 and PANC-1 cell lines under different oxygen conditions, whereas the sulforhodamine B protein assays perform well under all conditions. However, within a given oxygen environment, both proliferation assays show a correlation with cell number. Therefore, the MTT assay must be used with caution when comparing cell growth or drug response for cells grown in different oxygen environments. Supplementary Information The online version contains supplementary material available at 10.1007/s10616-023-00584-0.
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Affiliation(s)
- Ming Yao
- Department of Mechanical and Aerospace Engineering, North Carolina State University, 1840 Entrepreneur Drive, Raleigh, NC 27695-7910 USA
- Present Address: Department of Bioengineering, University of Washington, Seattle, WA 98195-5061 USA
| | - Glenn Walker
- UNC/NCSU Joint Department of Biomedical Engineering, 1840 Entrepreneur Drive, Box 7115, Raleigh, NC 27695-7115 USA
- Present Address: Department of Biomedical Engineering, University of Mississippi, Oxford, MS 38677-1848 USA
| | - Michael P. Gamcsik
- UNC/NCSU Joint Department of Biomedical Engineering, 1840 Entrepreneur Drive, Box 7115, Raleigh, NC 27695-7115 USA
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2
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Rivera KR, Bliton RJ, Burclaff J, Czerwinski MJ, Liu J, Trueblood JM, Hinesley CM, Breau KA, Deal HE, Joshi S, Pozdin VA, Yao M, Ziegler AL, Blikslager AT, Daniele MA, Magness ST. Hypoxia Primes Human ISCs for Interleukin-Dependent Rescue of Stem Cell Activity. Cell Mol Gastroenterol Hepatol 2023; 16:823-846. [PMID: 37562653 PMCID: PMC10520368 DOI: 10.1016/j.jcmgh.2023.07.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 07/26/2023] [Accepted: 07/27/2023] [Indexed: 08/12/2023]
Abstract
BACKGROUND AND AIMS Hypoxia in the intestinal epithelium can be caused by acute ischemic events or chronic inflammation in which immune cell infiltration produces inflammatory hypoxia starving the mucosa of oxygen. The epithelium has the capacity to regenerate after some ischemic and inflammatory conditions suggesting that intestinal stem cells (ISCs) are highly tolerant to acute and chronic hypoxia; however, the impact of hypoxia on human ISC (hISC) function has not been reported. Here we present a new microphysiological system (MPS) to investigate how hypoxia affects hISCs from healthy donors and test the hypothesis that prolonged hypoxia modulates how hISCs respond to inflammation-associated interleukins (ILs). METHODS hISCs were exposed to <1.0% oxygen in the MPS for 6, 24, 48, and 72 hours. Viability, hypoxia-inducible factor 1a (HIF1a) response, transcriptomics, cell cycle dynamics, and response to cytokines were evaluated in hISCs under hypoxia. HIF stabilizers and inhibitors were screened to evaluate HIF-dependent responses. RESULTS The MPS enables precise, real-time control and monitoring of oxygen levels at the cell surface. Under hypoxia, hISCs maintain viability until 72 hours and exhibit peak HIF1a at 24 hours. hISC activity was reduced at 24 hours but recovered at 48 hours. Hypoxia induced increases in the proportion of hISCs in G1 and expression changes in 16 IL receptors. Prolyl hydroxylase inhibition failed to reproduce hypoxia-dependent IL-receptor expression patterns. hISC activity increased when treated IL1β, IL2, IL4, IL6, IL10, IL13, and IL25 and rescued hISC activity caused by 24 hours of hypoxia. CONCLUSIONS Hypoxia pushes hISCs into a dormant but reversible proliferative state and primes hISCs to respond to a subset of ILs that preserves hISC activity. These findings have important implications for understanding intestinal epithelial regeneration mechanisms caused by inflammatory hypoxia.
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Affiliation(s)
- Kristina R Rivera
- Joint Department of Biomedical Engineering, North Carolina State University and University of North Carolina at Chapel Hill, Raleigh, North Carolina
| | - R Jarrett Bliton
- Joint Department of Biomedical Engineering, North Carolina State University and University of North Carolina at Chapel Hill, Raleigh, North Carolina
| | - Joseph Burclaff
- Joint Department of Biomedical Engineering, North Carolina State University and University of North Carolina at Chapel Hill, Raleigh, North Carolina
| | - Michael J Czerwinski
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Jintong Liu
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Jessica M Trueblood
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Caroline M Hinesley
- Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Keith A Breau
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Halston E Deal
- Joint Department of Biomedical Engineering, North Carolina State University and University of North Carolina at Chapel Hill, Raleigh, North Carolina
| | - Shlok Joshi
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Vladimir A Pozdin
- Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, North Carolina
| | - Ming Yao
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina
| | - Amanda L Ziegler
- Comparative Medicine Institute, Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Anthony T Blikslager
- Comparative Medicine Institute, Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Michael A Daniele
- Joint Department of Biomedical Engineering, North Carolina State University and University of North Carolina at Chapel Hill, Raleigh, North Carolina; Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, North Carolina
| | - Scott T Magness
- Joint Department of Biomedical Engineering, North Carolina State University and University of North Carolina at Chapel Hill, Raleigh, North Carolina; Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Center for Gastrointestinal Biology and Disease, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
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3
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Li W, McLeod D, Ketzenberger JT, Kowalik G, Russo R, Li Z, Kay MW, Entcheva E. High-throughput optical sensing of peri-cellular oxygen in cardiac cells: system characterization, calibration, and testing. Front Bioeng Biotechnol 2023; 11:1214493. [PMID: 37397961 PMCID: PMC10313526 DOI: 10.3389/fbioe.2023.1214493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Accepted: 06/07/2023] [Indexed: 07/04/2023] Open
Abstract
Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) represent a scalable experimental model relevant to human physiology. Oxygen consumption of hiPSC-CMs has not been studied in high-throughput (HT) format plates used in pre-clinical studies. Here, we provide comprehensive characterization and validation of a system for HT long-term optical measurements of peri-cellular oxygen in cardiac syncytia (human iPSC-CM and human cardiac fibroblasts), grown in glass-bottom 96-well plates. Laser-cut oxygen sensors having a ruthenium dye and an oxygen-insensitive reference dye were used. Ratiometric measurements (409 nm excitation) reflected dynamic changes in oxygen, as validated with simultaneous Clark electrode measurements. Emission ratios (653 nm vs. 510 nm) were calibrated for percent oxygen using two-point calibration. Time-dependent changes in the Stern-Volmer parameter, ksv, were observed during the initial 40-90 min of incubation, likely temperature-related. Effects of pH on oxygen measurements were negligible in the pH range of 4-8, with a small ratio reduction for pH > 10. Time-dependent calibration was implemented, and light exposure time was optimized (0.6-0.8 s) for oxygen measurements inside an incubator. Peri-cellular oxygen dropped to levels <5% within 3-10 h for densely-plated hiPSC-CMs in glass-bottom 96-well plates. After the initial oxygen decrease, samples either settled to low steady-state or exhibited intermittent peri-cellular oxygen dynamics. Cardiac fibroblasts showed slower oxygen depletion and higher steady-state levels without oscillations, compared to hiPSC-CMs. Overall, the system has great utility for long-term HT monitoring of peri-cellular oxygen dynamics in vitro for tracking cellular oxygen consumption, metabolic perturbations, and characterization of the maturation of hiPSC-CMs.
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Affiliation(s)
| | | | | | | | | | - Zhenyu Li
- Correspondence: Zhenyu Li, ; Matthew W. Kay, ; Emilia Entcheva,
| | - Matthew W. Kay
- Correspondence: Zhenyu Li, ; Matthew W. Kay, ; Emilia Entcheva,
| | - Emilia Entcheva
- Correspondence: Zhenyu Li, ; Matthew W. Kay, ; Emilia Entcheva,
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Zhang Z, Kalra H, Delzell MC, Jedlicka CR, Vasilyev M, Vasileva A, Tomasson MH, Bates ML. CORP: Sources and degrees of variability in whole animal intermittent hypoxia experiments. J Appl Physiol (1985) 2023; 134:1207-1215. [PMID: 36958346 PMCID: PMC10151045 DOI: 10.1152/japplphysiol.00643.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 02/17/2023] [Accepted: 03/12/2023] [Indexed: 03/25/2023] Open
Abstract
Chamber exposures are commonly used to evaluate the physiological and pathophysiological consequences of intermittent hypoxia in animal models. Researchers in this field use both commercial and custom-built chambers in their experiments. The purpose of this Cores of Reproducibility in Physiology paper is to demonstrate potential sources of variability in these systems that researchers should consider. Evaluating the relationship between arterial oxygen saturation and inspired oxygen concentration, we found that there are important sex-dependent differences in the commonly used C57BL6/J mouse model. The time delay of the oxygen sensor that provides feedback to the system during the ramp-down and ramp-up phases was different, limiting the number of cycles per hour that can be conducted and the overall stability of the oxygen concentration. The time to reach the hypoxic and normoxic hold stages, and the overall oxygen concentration, were impacted by the cycle number. These variables were further impacted by whether there are animals present in the chamber, highlighting the importance of verifying the cycling frequency with animals in the chamber. At ≤14 cycles/h, instability in the chamber oxygen concentration did not impact arterial oxygen saturation but may be important at higher cycle numbers. Taken together, these data demonstrate the important sources of variability that justify reporting and verifying the target oxygen concentration, cycling frequency, and arterial oxygen concentration, particularly when comparing different animal models and chamber configurations.NEW & NOTEWORTHY Intermittent hypoxia exposures are commonly used in physiology and many investigators use chamber systems to perform these studies. Because of the variety of chamber systems and protocols used, it is important to understand the sources of variability in intermittent hypoxia experiments that can impact reproducibility. We demonstrate sources of variability that come from the animal model, the intermittent hypoxia protocol, and the chamber system that can impact reproducibility.
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Affiliation(s)
- Zishan Zhang
- Interdisciplinary Graduate Program in Molecular Medicine, University of Iowa, Iowa City, Iowa, United States
- Division of Hematology, Oncology, and Bone Marrow Transplantation, Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Hardik Kalra
- Department of Health and Human Physiology, University of Iowa, Iowa City, Iowa, United States
| | - Matthew C Delzell
- Department of Health and Human Physiology, University of Iowa, Iowa City, Iowa, United States
- Kirksville College of Osteopathic Medicine, A.T. Still University, Kirksville, Missouri, United States
| | - Charles R Jedlicka
- Department of Health and Human Physiology, University of Iowa, Iowa City, Iowa, United States
| | - Mikhail Vasilyev
- Division of Hematology, Oncology, and Bone Marrow Transplantation, Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Anastasiia Vasileva
- Department of Health and Human Physiology, University of Iowa, Iowa City, Iowa, United States
| | - Michael H Tomasson
- Interdisciplinary Graduate Program in Molecular Medicine, University of Iowa, Iowa City, Iowa, United States
- Division of Hematology, Oncology, and Bone Marrow Transplantation, Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
- Department of Health and Human Physiology, University of Iowa, Iowa City, Iowa, United States
| | - Melissa L Bates
- Interdisciplinary Graduate Program in Molecular Medicine, University of Iowa, Iowa City, Iowa, United States
- Division of Hematology, Oncology, and Bone Marrow Transplantation, Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
- Department of Health and Human Physiology, University of Iowa, Iowa City, Iowa, United States
- Division of Neonatology, Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States
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Rivera KR, Bliton RJ, Burclaff J, Czerwinski MJ, Liu J, Trueblood JM, Hinesley CM, Breau KA, Joshi S, Pozdin VA, Yao M, Ziegler AL, Blikslager AT, Daniele MA, Magness ST. A new microphysiological system shows hypoxia primes human ISCs for interleukin-dependent rescue of stem cell activity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.31.524747. [PMID: 36778265 PMCID: PMC9915581 DOI: 10.1101/2023.01.31.524747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Background & Aims Hypoxia in the intestinal epithelium can be caused by acute ischemic events or conditions like Inflammatory Bowel Disease (IBD) where immune cell infiltration produces 'inflammatory hypoxia', a chronic condition that starves the mucosa of oxygen. Epithelial regeneration after ischemia and IBD suggests intestinal stem cells (ISCs) are highly tolerant to acute and chronic hypoxia; however, the impact of acute and chronic hypoxia on human ISC (hISC) properties have not been reported. Here we present a new microphysiological system (MPS) to investigate how hypoxia affects hISCs isolated from healthy human tissues. We then test the hypothesis that some inflammation-associated interleukins protect hISCs during prolonged hypoxia. Methods hISCs were exposed to <1.0% oxygen in the MPS for 6-, 24-, 48- & 72hrs. Viability, HIF1α response, transcriptomics, cell cycle dynamics, and hISC response to cytokines were evaluated. Results The novel MPS enables precise, real-time control and monitoring of oxygen levels at the cell surface. Under hypoxia, hISCs remain viable until 72hrs and exhibit peak HIF1α at 24hrs. hISCs lose stem cell activity at 24hrs that recovers at 48hrs of hypoxia. Hypoxia increases the proportion of hISCs in G1 and regulates hISC capacity to respond to multiple inflammatory signals. Hypoxia induces hISCs to upregulate many interleukin receptors and hISCs demonstrate hypoxia-dependent cell cycle regulation and increased organoid forming efficiency when treated with specific interleukins. Conclusions Hypoxia primes hISCs to respond differently to interleukins than hISCs in normoxia through a transcriptional response. hISCs slow cell cycle progression and increase hISC activity when treated with hypoxia and specific interleukins. These findings have important implications for epithelial regeneration in the gut during inflammatory events.
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Affiliation(s)
- Kristina R. Rivera
- Joint Department of Biomedical Engineering, North Carolina State University and University of North Carolina at Chapel Hill 911 Oval Dr., Raleigh, NC, 27695 (USA)
| | - R. Jarrett Bliton
- Joint Department of Biomedical Engineering, North Carolina State University and University of North Carolina at Chapel Hill 911 Oval Dr., Raleigh, NC, 27695 (USA)
| | - Joseph Burclaff
- Joint Department of Biomedical Engineering, North Carolina State University and University of North Carolina at Chapel Hill 911 Oval Dr., Raleigh, NC, 27695 (USA)
| | - Michael J. Czerwinski
- Department of Cell Biology & Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599 (USA)
| | - Jintong Liu
- Department of Cell Biology & Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599 (USA)
| | - Jessica M. Trueblood
- Center for Gastrointestinal Biology and Disease, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Caroline M. Hinesley
- Center for Gastrointestinal Biology and Disease, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Keith A Breau
- Department of Cell Biology & Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599 (USA)
| | - Shlok Joshi
- Department of Cell Biology & Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599 (USA)
| | - Vladimir A. Pozdin
- Department of Electrical & Computer Engineering, North Carolina State University, Raleigh, NC, 27695 (USA)
| | - Ming Yao
- Department of Mechanical & Aerospace Engineering, North Carolina State University, Raleigh, NC 27695 (USA)
| | - Amanda L. Ziegler
- Center for Gastrointestinal Biology and Disease, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Anthony T. Blikslager
- Center for Gastrointestinal Biology and Disease, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Michael A. Daniele
- Joint Department of Biomedical Engineering, North Carolina State University and University of North Carolina at Chapel Hill 911 Oval Dr., Raleigh, NC, 27695 (USA)
- Department of Electrical & Computer Engineering, North Carolina State University, Raleigh, NC, 27695 (USA)
| | - Scott T. Magness
- Joint Department of Biomedical Engineering, North Carolina State University and University of North Carolina at Chapel Hill 911 Oval Dr., Raleigh, NC, 27695 (USA)
- Department of Cell Biology & Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599 (USA)
- School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599 (USA)
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6
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Farré R, Almendros I, Martínez-García MÁ, Gozal D. Experimental Models to Study End-Organ Morbidity in Sleep Apnea: Lessons Learned and Future Directions. Int J Mol Sci 2022; 23:ijms232214430. [PMID: 36430904 PMCID: PMC9696027 DOI: 10.3390/ijms232214430] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 11/17/2022] [Accepted: 11/18/2022] [Indexed: 11/22/2022] Open
Abstract
Sleep apnea (SA) is a very prevalent sleep breathing disorder mainly characterized by intermittent hypoxemia and sleep fragmentation, with ensuing systemic inflammation, oxidative stress, and immune deregulation. These perturbations promote the risk of end-organ morbidity, such that SA patients are at increased risk of cardiovascular, neurocognitive, metabolic and malignant disorders. Investigating the potential mechanisms underlying SA-induced end-organ dysfunction requires the use of comprehensive experimental models at the cell, animal and human levels. This review is primarily focused on the experimental models employed to date in the study of the consequences of SA and tackles 3 different approaches. First, cell culture systems whereby controlled patterns of intermittent hypoxia cycling fast enough to mimic the rates of episodic hypoxemia experienced by patients with SA. Second, animal models consisting of implementing realistic upper airway obstruction patterns, intermittent hypoxia, or sleep fragmentation such as to reproduce the noxious events characterizing SA. Finally, human SA models, which consist either in subjecting healthy volunteers to intermittent hypoxia or sleep fragmentation, or alternatively applying oxygen supplementation or temporary nasal pressure therapy withdrawal to SA patients. The advantages, limitations, and potential improvements of these models along with some of their pertinent findings are reviewed.
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Affiliation(s)
- Ramon Farré
- Unitat de Biofísica i Bioenginyeria, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
- CIBER de Enfermedades Respiratorias, 1964603 Madrid, Spain
- Institut Investigacions Biomediques August Pi Sunyer, 08036 Barcelona, Spain
- Correspondence: (R.F.); (D.G.)
| | - Isaac Almendros
- Unitat de Biofísica i Bioenginyeria, Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
- CIBER de Enfermedades Respiratorias, 1964603 Madrid, Spain
- Institut Investigacions Biomediques August Pi Sunyer, 08036 Barcelona, Spain
| | - Miguel-Ángel Martínez-García
- CIBER de Enfermedades Respiratorias, 1964603 Madrid, Spain
- Pneumology Department, University and Polytechnic La Fe Hospital, 46026 Valencia, Spain
| | - David Gozal
- Department of Child Health and Child Health Research Institute, School of Medicine, The University of Missouri, Columbia, MO 65201, USA
- Correspondence: (R.F.); (D.G.)
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Yan Y, Li H, Yao H, Cheng X. Nanodelivery Systems Delivering Hypoxia-Inducible Factor-1 Alpha Short Interfering RNA and Antisense Oligonucleotide for Cancer Treatment. FRONTIERS IN NANOTECHNOLOGY 2022. [DOI: 10.3389/fnano.2022.932976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Hypoxia-inducible factor (HIF), which plays a crucial role in oxygen homeostasis, contributes to immunosuppression, tumor angiogenesis, multidrug resistance, photodynamic therapy resistance, and metastasis. HIF as a therapeutic target has attracted scientists’ strong academic research interests. Short interfering RNA (siRNA) and antisense oligonucleotide (ASO) are the more promising and broadly utilized methods for oligonucleotide-based therapy. Their physicochemical characteristics such as hydrophilicity, negative charge, and high molecular weight make them impossible to cross the cell membrane. Moreover, siRNA and ASO are subjected to a rapid deterioration in circulation and cannot translocate into nuclear. Delivery of siRNA and ASO to specific gene targets should be realized without off-target gene silencing and affecting the healthy cells. Nanoparticles as vectors for delivery of siRNA and ASO possess great advantages and flourish in academic research. In this review, we summarized and analyzed regulation mechanisms of HIF under hypoxia, the significant role of HIF in promoting tumor progression, and recent academic research on nanoparticle-based delivery of HIF siRNA and ASO for cancer immunotherapy, antiangiogenesis, reversal of multidrug resistance and radioresistance, potentiating photodynamic therapy, inhibiting tumor metastasis and proliferation, and enhancing apoptosis are reviewed in this thesis. Furthermore, we hope to provide some rewarding suggestions and enlightenments for targeting HIF gene therapy.
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8
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A multiwell plate-based system for toxicity screening under multiple static or cycling oxygen environments. Sci Rep 2021; 11:4020. [PMID: 33597640 PMCID: PMC7890056 DOI: 10.1038/s41598-021-83579-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 01/18/2021] [Indexed: 12/24/2022] Open
Abstract
Tumor tissue contains a continuous distribution of static and dynamically changing oxygen environments with levels ranging from physiologically normal oxygen down to anoxia. However, in vitro studies are often performed under oxygen levels that are far higher than those found in vivo. A number of devices are available to alter the oxygen environment in cell culture, including designs from our laboratory. However, in our devices and most other designs, changing the media in order to feed or dose cells remains a disruptive factor in maintaining a consistent hypoxic environment. This report presents a novel 96-well plate design that recirculates the local oxygen environment to shield cells during media changes and facilitates toxicity studies of cells cultured under varying oxygen levels. The principle behind the design is presented and the response of human pancreatic cancer PANC-1 cells treated with tirapazamine and doxorubicin under eight different static or cycling oxygen levels was measured. As expected, tirapazamine is progressively more toxic as oxygen levels decrease but retains some toxicity as oxygen is cycled between hypoxic and normoxic levels. Doxorubicin sensitivity is largely unaffected by changing oxygen levels. This technology is ideal for assessing the effects of oxygen as a variable in toxicity screens.
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9
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Abstract
Oxygen concentration varies tremendously within the body and has proven to be a critical variable in cell differentiation, proliferation, and drug metabolism among many other physiological processes. Currently, researchers study the gas's role in biology using low-throughput gas control incubators or hypoxia chambers in which all cells in a vessel are exposed to a single oxygen concentration. Here, we introduce a device that can simultaneously deliver 12 unique oxygen concentrations to cells in a 96-well plate and seamlessly integrate into biomedical research workflows. The device inserts into 96-well plates and delivers gas to the headspace, thus avoiding undesirable contact with media. This simple approach isolates each well using gas-tight pressure-resistant gaskets effectively creating 96 "mini-incubators". Each of the 12 columns of the plate is supplied by a distinct oxygen concentration from a gas-mixing gradient generator supplied by two feed gases. The wells within each column are then supplied by an equal flow-splitting distribution network. Using equal feed flow rates, concentrations ranging from 0.6 to 20.5% were generated within a single plate. A549 lung carcinoma cells were then used to show that O2 levels below 9% caused a stepwise increase in cell death for cells treated with the hypoxia-activated anticancer drug tirapirizamine (TPZ). Additionally, the 96-well plate was further leveraged to simultaneously test multiple TPZ concentrations over an oxygen gradient and generate a three-dimensional (3D) dose-response landscape. The results presented here show how microfluidic technologies can be integrated into, rather than replace, ubiquitous biomedical labware allowing for increased throughput oxygen studies.
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Affiliation(s)
- Adam Szmelter
- Department of Bioengineering, University of Illinois at Chicago, 851 South Morgan Street, Chicago, Illinois 60607, United States
| | - Jason Jacob
- Department of Bioengineering, University of Illinois at Chicago, 851 South Morgan Street, Chicago, Illinois 60607, United States
| | - David T Eddington
- Department of Bioengineering, University of Illinois at Chicago, 851 South Morgan Street, Chicago, Illinois 60607, United States
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10
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Cheng X, Li H, Ge X, Chen L, Liu Y, Mao W, Zhao B, Yuan WE. Tumor-Microenvironment- Responsive Size-Shrinkable Drug-Delivery Nanosystems for Deepened Penetration Into Tumors. Front Mol Biosci 2020; 7:576420. [PMID: 33330618 PMCID: PMC7729065 DOI: 10.3389/fmolb.2020.576420] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 08/13/2020] [Indexed: 01/04/2023] Open
Abstract
Over the years, the manipulation and clinical application of drug-delivery nanosystems for cancer diseases have attracted a rapid growth of academic research interests, and some nanodrugs have been approved for clinic application. Although encouraging achievements have been made, the potency of nanomedicines in cancer treatment is far from satisfaction, and one significant reason is the inefficient penetration of nanoparticles into solid tumors. Particle size is one of the most significant features that influence diffusion ability of the drug-delivery system in tumors. Size-shrinkable drug-delivery nanosystems possess a size-switchable property that can achieve passive targeting via the enhanced permeability and retention (EPR) effect and transform into ultrasmall particles in tumors for deep penetration into tumors. The tumor microenvironment is characterized by acidic pH, hypoxia, upregulated levels of enzymes, and a redox environment. In this review, we summarize and analyze the current research progresses and challenges in tumor microenvironment responsive size-shrinkable drug-delivery nanosystems. We further expect to present some meaningful proposals and enlightenments on promoting deep penetration into tumors of nanoparticles.
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Affiliation(s)
- Xiaoliang Cheng
- Department of Pharmacy, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Houli Li
- Department of Pharmacy, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Xuemei Ge
- Department of Food Science and Technology, College of Light Industry Science and Engineering, Nanjing Forestry University, Nanjing, China
| | - Lijuan Chen
- Department of Food Science and Technology, College of Light Industry Science and Engineering, Nanjing Forestry University, Nanjing, China
| | - Yao Liu
- Instrumental Analysis Center, Shanghai Jiao Tong University, Shanghai, China
| | - Wenwei Mao
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, and School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China
| | - Bo Zhao
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, and School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China
| | - Wei-En Yuan
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, and School of Pharmacy, Shanghai Jiao Tong University, Shanghai, China
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11
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Yao M, Rabbani ZN, Sattler T, Nguyen KG, Zaharoff DA, Walker G, Gamcsik MP. Flow-Encoded Oxygen Control to Track the Time-Dependence of Molecular Changes Induced by Static or Cycling Hypoxia. Anal Chem 2019; 91:15032-15039. [PMID: 31694368 DOI: 10.1021/acs.analchem.9b03709] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Detecting the effects of low oxygen on cell function is often dependent on monitoring the expression of a number of hypoxia markers. The time dependence of the appearance and stability of these markers varies between cell lines. Assessing cellular marker dynamics is also critical to determining how quickly cells respond to transient changes in oxygen levels that occurs with cycling hypoxia. We fabricated a manifold designed to use flow-encoding to produce sequential changes in gas mixtures delivered to a permeable-bottom 96-well plate. We show how this manifold and plate design can be used to expose cells to either static or cycling hypoxic conditions for eight different time periods thereby facilitating the study of the time-response of cells to altered oxygen environments. Using this device, we monitored the time-dependence of molecular changes in human PANC-1 pancreatic carcinoma and Caco-2 colon adenocarcinoma cells exposed to increasing periods of static or cycling hypoxia. Using immunohistochemistry, both cell lines show detectable levels of the marker protein hypoxia-inducible factor-1α (HIF-1α) after 3 h of exposure to static hypoxia. Cycling hypoxia increased the expression level of HIF-1α compared to static hypoxia. Both static and cycling hypoxia also increased glucose uptake and aldehyde dehydrogenase activity. This new device offers a facile screening approach to determine the kinetics of cellular alterations under varying oxygen conditions.
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Affiliation(s)
- Ming Yao
- Department of Mechanical and Aerospace Engineering , North Carolina State University , Raleigh , North Carolina 27695 , United States
| | - Zahid N Rabbani
- UNC/NCSU Joint Department of Biomedical Engineering , Raleigh , North Carolina 27695 , United States
| | - Tyler Sattler
- UNC/NCSU Joint Department of Biomedical Engineering , Raleigh , North Carolina 27695 , United States
| | - Khue G Nguyen
- UNC/NCSU Joint Department of Biomedical Engineering , Raleigh , North Carolina 27695 , United States
| | - David A Zaharoff
- UNC/NCSU Joint Department of Biomedical Engineering , Raleigh , North Carolina 27695 , United States
| | - Glenn Walker
- UNC/NCSU Joint Department of Biomedical Engineering , Raleigh , North Carolina 27695 , United States
| | - Michael P Gamcsik
- UNC/NCSU Joint Department of Biomedical Engineering , Raleigh , North Carolina 27695 , United States
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