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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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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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Papakonstantinou A, Koumarianou P, Rigakou A, Diamantakos P, Frakolaki E, Vassilaki N, Chavdoula E, Melliou E, Magiatis P, Boleti H. New Affordable Methods for Large-Scale Isolation of Major Olive Secoiridoids and Systematic Comparative Study of Their Antiproliferative/Cytotoxic Effect on Multiple Cancer Cell Lines of Different Cancer Origins. Int J Mol Sci 2022; 24:ijms24010003. [PMID: 36613449 PMCID: PMC9820430 DOI: 10.3390/ijms24010003] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 12/24/2022] Open
Abstract
Olive oil phenols (OOPs) are associated with the prevention of many human cancers. Some of these have been shown to inhibit cell proliferation and induce apoptosis. However, no systematic comparative study exists for all the investigated compounds under the same conditions, due to difficulties in their isolation or synthesis. Herein are presented innovative methods for large-scale selective extraction of six major secoiridoids from olive oil or leaves enabling their detailed investigation. The cytotoxic/antiproliferative bioactivity of these six compounds was evaluated on sixteen human cancer cell lines originating from eight different tissues. Cell viability with half-maximal effective concentrations (EC50) was evaluated after 72 h treatments. Antiproliferative and pro-apoptotic effects were also assessed for the most bioactive compounds (EC50 ≤ 50 μM). Oleocanthal (1) showed the strongest antiproliferative/cytotoxic activity in most cancer cell lines (EC50: 9−20 μM). The relative effectiveness of the six OOPs was: oleocanthal (1) > oleuropein aglycone (3a,b) > ligstroside aglycone (4a,b) > oleacein (2) > oleomissional (6a,b,c) > oleocanthalic acid (7). This is the first detailed study comparing the bioactivity of six OOPs in such a wide array of cancer cell lines, providing a reference for their relative antiproliferative/cytotoxic effect in the investigated cancers.
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Affiliation(s)
- Aikaterini Papakonstantinou
- Intracellular Parasitism Laboratory, Microbiology Department, Hellenic Pasteur Institute, 11521 Athens, Greece
- Laboratory of Pharmacognosy and Natural Products Chemistry, Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
| | - Petrina Koumarianou
- Intracellular Parasitism Laboratory, Microbiology Department, Hellenic Pasteur Institute, 11521 Athens, Greece
- Light Microscopy Unit, Hellenic Pasteur Institute, 11521 Athens, Greece
| | - Aimilia Rigakou
- Laboratory of Pharmacognosy and Natural Products Chemistry, Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
| | - Panagiotis Diamantakos
- Laboratory of Pharmacognosy and Natural Products Chemistry, Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
| | - Efseveia Frakolaki
- Molecular Virology Laboratory, Microbiology Department, Hellenic Pasteur Institute, 11521 Athens, Greece
| | - Niki Vassilaki
- Molecular Virology Laboratory, Microbiology Department, Hellenic Pasteur Institute, 11521 Athens, Greece
| | - Evangelia Chavdoula
- Biomedical Research Division, Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology, 45110 Ioannina, Greece
| | - Eleni Melliou
- Laboratory of Pharmacognosy and Natural Products Chemistry, Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
- World Olive Center for Health, Imittou 76, 11634 Athens, Greece
| | - Prokopios Magiatis
- Laboratory of Pharmacognosy and Natural Products Chemistry, Department of Pharmacy, National and Kapodistrian University of Athens, Panepistimiopolis Zografou, 15771 Athens, Greece
- Correspondence: (P.M.); (H.B.); Tel.: +30-210-7274052 (P.M.); +30-210-6478879 (H.B.)
| | - Haralabia Boleti
- Intracellular Parasitism Laboratory, Microbiology Department, Hellenic Pasteur Institute, 11521 Athens, Greece
- Light Microscopy Unit, Hellenic Pasteur Institute, 11521 Athens, Greece
- Correspondence: (P.M.); (H.B.); Tel.: +30-210-7274052 (P.M.); +30-210-6478879 (H.B.)
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Grist SM, Bennewith KL, Cheung KC. Oxygen Measurement in Microdevices. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2022; 15:221-246. [PMID: 35696522 DOI: 10.1146/annurev-anchem-061020-111458] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Oxygen plays a fundamental role in respiration and metabolism, and quantifying oxygen levels is essential in many environmental, industrial, and research settings. Microdevices facilitate the study of dynamic, oxygen-dependent effects in real time. This review is organized around the key needs for oxygen measurement in microdevices, including integrability into microfabricated systems; sensor dynamic range and sensitivity; spatially resolved measurements to map oxygen over two- or three-dimensional regions of interest; and compatibility with multimodal and multianalyte measurements. After a brief overview of biological readouts of oxygen, followed by oxygen sensor types that have been implemented in microscale devices and sensing mechanisms, this review presents select recent applications in organs-on-chip in vitro models and new sensor capabilities enabling oxygen microscopy, bioprocess manufacturing, and pharmaceutical industries. With the advancement of multiplexed, interconnected sensors and instruments and integration with industry workflows, intelligent microdevice-sensor systems including oxygen sensors will have further impact in environmental science, manufacturing, and medicine.
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Affiliation(s)
- Samantha M Grist
- School of Biomedical Engineering, Centre for Blood Research, University of British Columbia, Vancouver, British Columbia, Canada;
| | - Kevin L Bennewith
- Integrative Oncology Department, BC Cancer Research Institute, Vancouver, British Columbia, Canada
| | - Karen C Cheung
- School of Biomedical Engineering, Centre for Blood Research, University of British Columbia, Vancouver, British Columbia, Canada;
- Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, British Columbia, Canada
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