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Chen X, Murdoch R, Shafer DJ, Ajuwon KM, Applegate TJ. Cytotoxicity of various chemicals and mycotoxins in fresh primary duck embryonic fibroblasts: a comparison to HepG2 cells. J Appl Toxicol 2016; 36:1437-45. [PMID: 26889939 DOI: 10.1002/jat.3298] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 12/16/2015] [Accepted: 01/04/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Xi Chen
- Department of Animal Sciences; Purdue University; West Lafayette IN 47906 USA
| | | | | | - Kolapo M. Ajuwon
- Department of Animal Sciences; Purdue University; West Lafayette IN 47906 USA
| | - Todd J. Applegate
- Department of Animal Sciences; Purdue University; West Lafayette IN 47906 USA
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2
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Tavakolinejad S, Khosravi M, Mashkani B, Ebrahimzadeh Bideskan A, Sanjar Mossavi N, Parizadeh MRS, Hamidi Alamdari D. The effect of human platelet-rich plasma on adipose-derived stem cell proliferation and osteogenic differentiation. IRANIAN BIOMEDICAL JOURNAL 2015; 18:151-157. [PMID: 24842141 PMCID: PMC4048479 DOI: 10.6091/ibj.1301.2014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND The cultured mesenchymal stem cells (MSC) have been used in many clinical trials; however, there are still some concerns about the cultural conditions. One concern is related to the use of FBS as a widely used xenogeneic supplement in the culture system. Human platelet-rich plasma (hPRP) is a candidate replacement for FBS. In this study, the effect of hPRP on MSC proliferation and osteogenic differentiation has been evaluated. METHODS Human adipose-derived stem cells (hADSC) were expanded. Cells from the third passage were characterized by flow cytometric analysis and used for in vitro experiments. Resazurin and alizarin red stains were used for cell proliferation and osteogenic differentiation assays, respectively. RESULTS Treatment with hPRP resulted in a statistically significant increase in cell proliferation compare to the negative control group (P<0.001). Cell proliferation in the 15% hPRP group was also significantly higher than that in the 10% hPRP group (P<0.05). Additionally, it caused less osteogenic differentiation of the hADSC compared to the FBS (P<0.001), but in comparison to negative control, it caused acceptable mineralization (P<0.001). CONCLUSION These findings indicate that hPRP not only improves the proliferation but also it can be a suitable substitution in osteogenic differentiation for clinical purposes. However, the clinical application value of hPRP still needs more investigation.
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Affiliation(s)
- Sima Tavakolinejad
- Dept. of Anatomy and Cell Biology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohsen Khosravi
- Dept. of Clinical Biochemistry, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Baratali Mashkani
- Dept. of Clinical Biochemistry, Mashhad University of Medical Sciences, Mashhad, Iran
| | | | | | | | - Daryoush Hamidi Alamdari
- Stem cell and Regenerative Medicine Research Group, Biochemistry and Nutrition Research Center, Dept. of Clinical Biochemistry, School of Medicine,
Mashhad University of Medical Sciences, Mashhad, Iran
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Rudzok S, Krejči S, Graebsch C, Herbarth O, Mueller A, Bauer M. Toxicity profiles of four metals and 17 xenobiotics in the human hepatoma cell line HepG2 and the protozoa Tetrahymena pyriformis--a comparison. ENVIRONMENTAL TOXICOLOGY 2011; 26:171-186. [PMID: 19790250 DOI: 10.1002/tox.20541] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We performed an interspecies comparison for the human hepatoma cell line HepG2 and the eukaryotic single cell organism Tetrahymena pyriformis (T. pyriformis) for 17 xenobiotics with diverse structures and four metals. The cytotoxicity was assessed by four different cell viability assays (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide reduction (MTT), neutral red uptake (NRU), resazurin dye (AlamarBlue), 5-carboxyfluorescein diacetate acetoxymethyl ester (CFDA-AM)) for the HepG2 and by cell count and MTT for T. pyriformis. For HepG2 cells, the results revealed interassay variations depending on the compound. The highest assay conformity was found for the metal Hg(2+) and the fungicide prochloraz. The AlamarBlue assay was the most sensitive assay according to low-effect concentrations. By contrast, the NRU assay was comprised of more frequent whole concentration response relationships and was more susceptible to EC(50). For T. pyriformis the EC(50) values of the two applied assays displayed a high conformity (R(2) = 0.97). Comparing the EC(50) values obtained by the MTT assay for the two cell models, a direct correlation was absent for the xenobiotics and only present for the metals (Cd(2+), Cu(2+), and Ni(2+)). Moreover, the protozoa T. pyriformis displayed a 20 times higher sensitivity than the cell line. The highest interspecies difference of three log degrees was obtained for the polycyclic aromatic hydrocarbon fluoranthene. In addition, a correlation of the EC(50) values and octanol-water partition coefficient (log K(OW)) of the xenobiotics was performed. No correlation was found for HepG2, and a weak one for T. pyriformis. Interestingly, the interspecies difference of logarithmized EC(50) correlated positive with the log K(OW) (R(2) = 0.65). In conclusion, to obtain reliable evidence for human cytotoxicity, more than one viability/cytotoxicity assay had to be applied for cell lines. Second, the human hepatoma cell line was less affected by the organic compounds than the eukaryotic single-cell organism and was also less dependent on the log K(OW) of the xenobiotic.
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Affiliation(s)
- Susanne Rudzok
- Helmholtz Centre for Environmental Research-UFZ, Division Health Research, Leipzig, Germany
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Ke N, Wang X, Xu X, Abassi YA. The xCELLigence system for real-time and label-free monitoring of cell viability. Methods Mol Biol 2011; 740:33-43. [PMID: 21468966 DOI: 10.1007/978-1-61779-108-6_6] [Citation(s) in RCA: 289] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We describe here the use of the xCELLigence system for label-free and real-time monitoring of cell -viability. The xCELLigence system uses specially designed microtiter plates containing interdigitated gold microelectrodes to noninvasively monitor the viability of cultured cells using electrical impedance as the readout. The continuous monitoring of cell viability by the xCELLigence system makes it possible to distinguish between different perturbations of cell viability, such as senescence, cell toxicity (cell death), and reduced proliferation (cell cycle arrest). In addition, the time resolution of the xCELLigence system allows for the determination of optimal time points to perform standard cell viability assays as well as other end-point assays to understand the mode of action. We have used the WST-1 assay (end-point viability readout), the cell index determination (continuous monitoring of viability by xCELLigence), and the DNA fragmentation assay (end-point apoptosis assay) to systematically examine cytotoxic effects triggered by two cytotoxic compounds with different cell-killing kinetics. Good correlation was observed for viability readouts between WST-1 and cell index. The significance of time resolution by xCELLigence readout is exemplified by its ability to pinpoint the optimal time points for conducting end point viability and apoptosis assays.
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Affiliation(s)
- Ning Ke
- ACEA Biosciences Inc., San Diego, CA, USA
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5
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Nguyen DM, Wang X, Ahn HY, Rodriguez L, Bondar MV, Belfield KD. Novel hydrophilic bis(1,2,3-triazolyl)fluorenyl probe for in vitro zinc ion sensing. ACS APPLIED MATERIALS & INTERFACES 2010; 2:2978-81. [PMID: 21028841 PMCID: PMC2991498 DOI: 10.1021/am100719v] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A hydrophilic bis(1,2,3-triazolyl)fluorene derivative was synthesized as a multi-photon-absorbing, zinc-ion-sensing fluorescent probe. The fluorescence response was approximately five-fold greater in presence of Zn(2+), resulting in a large binding constant (1 × 10(9)) for a 1:2 ligand to zinc complex. A four-fold increase in the two-photon absorption cross section was achieved upon binding Zn(2+). In vitro two-photon fluorescence microscopy imaging revealed a significant fluorescence increase upon introduction of Zn(2+) into HeLa cells and reversible Zn(2+) binding, demonstrating the potential of this probe for zinc ion sensing.
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Affiliation(s)
- Dao M. Nguyen
- Department of Chemistry, University of Central Florida, 4000 Central Florida Parkway, Orlando, FL 32816, USA
| | - Xuhua Wang
- Department of Chemistry, University of Central Florida, 4000 Central Florida Parkway, Orlando, FL 32816, USA
| | - Hyo-Yang Ahn
- Department of Chemistry, University of Central Florida, 4000 Central Florida Parkway, Orlando, FL 32816, USA
| | - Luis Rodriguez
- Department of Chemistry, University of Central Florida, 4000 Central Florida Parkway, Orlando, FL 32816, USA
| | | | - Kevin D. Belfield
- Department of Chemistry, University of Central Florida, 4000 Central Florida Parkway, Orlando, FL 32816, USA
- CREOL, The College of Optics and Photonics, University of Central Florida, 4000 Central Florida Parkway, Orlando, FL 32816, USA
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Uzunoglu S, Karaca B, Atmaca H, Kisim A, Sezgin C, Karabulut B, Uslu R. Comparison of XTT and Alamar blue assays in the assessment of the viability of various human cancer cell lines by AT-101 (−/− gossypol). Toxicol Mech Methods 2010; 20:482-6. [DOI: 10.3109/15376516.2010.508080] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Xiao J, Zhang Y, Wang J, Yu W, Wang W, Ma X. Monitoring of cell viability and proliferation in hydrogel-encapsulated system by resazurin assay. Appl Biochem Biotechnol 2010; 162:1996-2007. [PMID: 20437208 DOI: 10.1007/s12010-010-8975-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2010] [Accepted: 04/18/2010] [Indexed: 12/19/2022]
Abstract
Cell microencapsulation is a promising approach for cell implantation, cell-based gene therapy and large-scale cell culture. For better quality control, it is important to accurately measure the microencapsulated cell viability and proliferation in the culture. A number of assays have been used for this purpose, but limitations arise. In this study, we investigated the feasibility and reliability of resazurin as a cell growth indicator in microencapsulated culture system. According to the experiment data, there was a reversible, time- and dose-dependent growth inhibition as observed for resazurin application in encapsulated cells. A positive relationship was observed between reduction of resazurin and CHO cell number in microcapsule. Moreover, the resazurin assay provided an equivalent result to the commonly used MTT method in determining CHO cell proliferation in APA microcapsule with no notable influence on cell distribution and organization pattern. In conclusion, resazurin assay is offered as a simple, rapid and non-invasive method for in vitro microencapsulated cell viability and proliferation measurement.
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Affiliation(s)
- Jing Xiao
- Department of Science and Technology, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, People's Republic of China
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Wang MS, Boddapati S, Emadi S, Sierks MR. Curcumin reduces alpha-synuclein induced cytotoxicity in Parkinson's disease cell model. BMC Neurosci 2010; 11:57. [PMID: 20433710 PMCID: PMC2879277 DOI: 10.1186/1471-2202-11-57] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2009] [Accepted: 04/30/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Overexpression and abnormal accumulation of aggregated alpha-synuclein (alphaS) have been linked to Parkinson's disease (PD) and other synucleinopathies. alphaS can misfold and adopt a variety of morphologies but recent studies implicate oligomeric forms as the most cytotoxic species. Both genetic mutations and chronic exposure to neurotoxins increase alphaS aggregation and intracellular reactive oxygen species (ROS), leading to mitochondrial dysfunction and oxidative damage in PD cell models. RESULTS Here we show that curcumin can alleviate alphaS-induced toxicity, reduce ROS levels and protect cells against apoptosis. We also show that both intracellular overexpression of alphaS and extracellular addition of oligomeric alphaS increase ROS which induces apoptosis, suggesting that aggregated alphaS may induce similar toxic effects whether it is generated intra- or extracellulary. CONCLUSIONS Since curcumin is a natural food pigment that can cross the blood brain barrier and has widespread medicinal uses, it has potential therapeutic value for treating PD and other neurodegenerative disorders.
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Affiliation(s)
- Min S Wang
- Department of Chemical Engineering, Arizona State University, Tempe, AZ 85287-6006, USA
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Wang MS, Boddapati S, Sierks MR. Antifibrillizing agents catalyze the formation of unstable intermediate aggregates of beta-amyloid. Biotechnol Prog 2010; 26:1172-9. [PMID: 20306540 DOI: 10.1002/btpr.396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Although Alzheimer's disease (AD) is characterized by the extracellular deposition of fibrillar aggregates of beta-amyloid (Abeta), transient oligomeric species of Abeta are increasingly implicated in the pathogenesis of AD. Natively unfolded monomeric Abeta can misfold and progressively assemble into fibrillar aggregates, following a well-established "on pathway" seeded-nucleation mechanism. Here, we show that three simple saccharides, mannose, sucrose, and raffinose, alter Abeta aggregation kinetics and morphology. The saccharides inhibit formation of Abeta fibrils but promote formation of various oligomeric aggregate species through different "off pathway" aggregation mechanisms at 37 degrees C but not at 60 degrees C. The various oligomeric Abeta aggregates formed when coincubated with the different saccharides are morphologically distinct but all are toxic toward SH-SY5Y human neuroblastoma cells, increasing the level of toxicity and greatly prolonging toxicity compared with Abeta alone. As a wide variety of anti-Abeta aggregation strategies are being actively pursued as potential therapeutics for AD, these studies suggest that care must be taken to ensure that the therapeutic agents also block toxic oligomeric Abeta assembly as well as inhibit fibril formation.
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Affiliation(s)
- Min S Wang
- Department, of Chemical Engineering, Arizona State University, Tempe, AZ 85287, USA
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10
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Cyclodextrins promote protein aggregation posing risks for therapeutic applications. Biochem Biophys Res Commun 2009; 386:526-31. [DOI: 10.1016/j.bbrc.2009.06.077] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2009] [Accepted: 06/15/2009] [Indexed: 10/20/2022]
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11
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Shum D, Radu C, Kim E, Cajuste M, Shao Y, Seshan VE, Djaballah H. A high density assay format for the detection of novel cytotoxic agents in large chemical libraries. J Enzyme Inhib Med Chem 2009; 23:931-45. [PMID: 18608772 DOI: 10.1080/14756360701810082] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
In response to the need for inexpensive high throughput assays for anti-cancer drug screening, a 1536-well microtiter plate based assay utilizing the Alamar Blue fluorescent dye as a measure of cellular growth was validated in 10 microL assay volume. Its robustness was assessed in a screen against a library of 2000 known bioactives; with an overall Z' value of 0.89 for assay robustness, several known cytotoxic agents were identified including and not limited to anthracyclines, cardiac glycosides, gamboges, and quinones. To further test the sensitivity of the assay, IC50 determinations were performed in both 384-well and 1536-well formats and the obtained results show a very good correlation between the two density formats. These findings demonstrate that this newly developed assay is simple to set up, robust, highly sensitive and inexpensive. It could potentially provide a rapid way to screen established and primary tumor cell lines against large chemical libraries.
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Affiliation(s)
- David Shum
- High Throughput Screening Core Facility, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10021, USA
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Perrot S, Dutertre-Catella H, Martin C, Warnet JM, Rat P. A new nondestructive cytometric assay based on resazurin metabolism and an organ culture model for the assessment of corneal viability. Cytometry A 2003; 55:7-14. [PMID: 12938183 DOI: 10.1002/cyto.a.10067] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND Three-dimensional culture or human corneal equivalents for safety testing are difficult to investigate with classic cytometric or biochemical methods. So a fluorometric method is proposed using resazurin probe. METHODS Absorbance and fluorescence spectra of the oxidized and reduced forms of resazurin were performed to determine optimal measurement conditions. More than 100 enucleated porcine eyes were used for this experiment. Twelve corneas were immersed in resazurin solution and fluorescence was measured hourly from 1 to 10 h. Ninety benzalkonium chloride-treated corneas and control corneas were used as toxicity controls, and corneal viability was compared with in vivo rabbit eye irritation. RESULTS After analysis of spectra, the optimal measurement condition of resazurin metabolism proved to be a fluorescence measurement using 570 nm excitation wavelength and 590 nm emission wavelength. The reduction of resazurin was optimal after 6 h of incubation. Resazurin metabolism by isolated pig corneas varied proportionately with the benzalkonium chloride concentration employed, clearly showing significant differences (P < 0.001) in agreement with the in vivo data. CONCLUSION The resazurin metabolism test can be used to evaluate corneal viability and can thus be a potential alternative for toxicological assessments. This assay allows rapid assessment of non destructed samples, with simple equipment and at a reduced cost for continuous monitoring of corneal viability and possibly other three-dimensional cellular models.
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Affiliation(s)
- Sébastien Perrot
- Laboratoire de Toxicologie, Faculté des Sciences Pharmaceutiques et Biologiques, Université Paris V, Paris, France
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Kitani H, Black SJ, Nakamura Y, Naessens J, Murphy NB, Yokomizo Y, Gibson J, Iraqi F. Recombinant tumor necrosis factor alpha does not inhibit the growth of African trypanosomes in axenic cultures. Infect Immun 2002; 70:2210-4. [PMID: 11895989 PMCID: PMC127870 DOI: 10.1128/iai.70.4.2210-2214.2002] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mice whose tumor necrosis factor alpha (TNF-alpha) genes were disrupted developed higher levels of parasitemia than wild-type mice following infection with Trypanosoma congolense IL1180 or T. brucei brucei GUTat3.1, confirming the results of earlier studies. To determine whether TNF-alpha directly affects the growth of these and other bloodstream forms of African trypanosomes, we studied the effects of recombinant mouse, human, and bovine TNF-alpha on the growth of two isolates of T. congolense, IL1180 and IL3338, and two isolates of T. brucei brucei, GUTat3.1 and ILTat1.1, under axenic culture conditions. The preparations of recombinant TNF-alpha used were biologically active as determined by their capacity to kill L929 cells. Of five recombinant TNF-alpha lots tested, one lot of mouse TNF-alpha inhibited the growth of both isolates of T. brucei brucei and one lot of bovine TNF-alpha inhibited the growth of T. brucei brucei ILTat1.1 but only at very high concentrations and without causing detectable killing of the parasites. The other lots of mouse recombinant TNF-alpha, as well as human TNF-alpha, did not affect the growth of any of the test trypanosomes even at maximal concentrations that could be attained in the culture systems (3,000 to 15,000 U of TNF-alpha/ml of medium). These results suggest that exogenously added recombinant TNF-alpha generally does not inhibit the growth of African trypanosomes under the culture conditions we used. The impact of TNF-alpha on trypanosome parasitemia may be indirect, at least with respect to the four strains of trypanosomes reported here.
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Affiliation(s)
- Hiroshi Kitani
- Japan International Research Center for Agricultural Sciences, Tsukuba, Ibaraki, Japan.
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Steff AM, Fortin M, Arguin C, Hugo P. Detection of a decrease in green fluorescent protein fluorescence for the monitoring of cell death: an assay amenable to high-throughput screening technologies. CYTOMETRY 2001; 45:237-43. [PMID: 11746092 DOI: 10.1002/1097-0320(20011201)45:4<237::aid-cyto10024>3.0.co;2-j] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Reliable assessment of cell death is now pivotal to many research programs aiming at generating new anti-tumor compounds or at screening cDNA libraries. Such approaches need to rely on reproducible, easy-to-handle, and rapid microplate-based cytotoxicity assays that are amenable to high-throughput screening (HTS) technologies. We describe a method for the direct measurement of cell death, based on the detection of a decrease in fluorescence observed following death induction in cells expressing enhanced green fluorescent protein (EGFP). METHODS Cell death was induced by a variety of apoptotic stimuli in various EGFP-expressing mammalian cell lines, including those routinely used in anti-cancer drug screening. Decrease in fluorescence was assessed either by flow cytometry (and compared with other apoptotic markers) or by a fluorescence microplate reader. RESULTS Cells expressing EGFP exhibited a decrease in fluorescence when treated by various agents, such as chemotherapeutic drugs, UV irradiation, or caspase-independent cell death inducers. Kinetics and sensitivity of this EGFP-based assay were comparable to those of traditional apoptosis markers such as annexin-V binding, propidium iodide incorporation, or reactive oxygen species production. We also show that the decrease in EGFP fluorescence is directly quantifiable in a fluorescence-based microplate assay. Furthermore, analysis of EGFP protein content in cells undergoing cell death demonstrates that the decrease in fluorescence does not arise from degradation of the protein. CONCLUSIONS This novel GFP-based microplate assay combines sensitivity and rapidity, is easily amenable to HTS setups, making it an assay of choice for cytotoxicity evaluation.
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Affiliation(s)
- A M Steff
- PROCREA BioSciences, Division of Research and Development, Montreal, Quebec, Canada
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15
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Seifalian AM, Salacinski HJ, Punshon G, Krijgsman B, Hamilton G. A new technique for measuring the cell growth and metabolism of endothelial cells seeded on vascular prostheses. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2001; 55:637-44. [PMID: 11288093 DOI: 10.1002/1097-4636(20010615)55:4<637::aid-jbm1058>3.0.co;2-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
For the improvement of vascular graft patency, an endothelial cell (EC) lining is desirable. It is essential that the EC remains viable after being seeded onto the prosthetic graft. The aim of this study was to adapt an Alamar redox assay (ABRA) as a technique to monitor the viability of ECs seeded on prosthetic grafts. To test the graft types, we seeded human umbilical vein ECs on compliant polyurethane (CPU), expanded polytetrafluoroethylene, and Dacron at a density of 2 x 10(5) cell/cm(2). After 24 h of incubation, ABRA was added, and the absorbance was measured at 4, 8, and 24 h. To assess seeded cell concentrations on grafts, we seeded CPU at densities ranging from 1 x 10(5) to 8 x 10(5) cell/cm(2). The validity of the test was assessed with sodium azide and mitomycin C, known physiological perturbators. ABRA reduction demonstrated that ECs were viable and functional postseeding on the prosthetic grafts. A significant correlation was observed with ABRA reduction and cell concentrations (p < 0.001). The acid phosphatase assay demonstrated enzyme activity in the cells, but they were not maintained under normal physiological conditions. The ABRA bioreduced product was soluble, stable, and noncytotoxic over 24 h. The assay is independent of the geometry or physiochemistry of the graft type. The technique allows the continuous assessment of the metabolism and viability of seeded cells, is simple to perform, and does not destroy the cells or graft materials.
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Affiliation(s)
- A M Seifalian
- Vascular Haemodynamic Laboratory, University Department of Surgery, Royal Free and University College Medical School, University College London and the Royal Free Hospital, London, England.
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16
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Jones LJ, Singer VL. Fluorescence Microplate-Based Assay for Tumor Necrosis Factor Activity Using SYTOX Green Stain. Anal Biochem 2001; 293:8-15. [PMID: 11373072 DOI: 10.1006/abio.2001.5116] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have developed a simple, sensitive, fluorescence microplate-based assay for tumor necrosis factor (TNF) biological activity. The assay employs SYTOX Green nucleic acid stain to detect TNF-induced cell necrosis in actinomycin D sensitized cultured cell lines. SYTOX Green stain is a cationic unsymmetrical cyanine dye that is excluded from live cells but can readily penetrate cells with compromised cell membranes. Upon binding to cellular nucleic acids, the dye exhibits a large enhancement in fluorescence, which is monitored at fluorescein wavelengths. We detected 2.5 pg/mL and quantitated 25-500 pg/mL recombinant murine (rm) and recombinant human (rh) TNF-alpha, using mouse fibroblast-derived WEHI 164, WEHI 13var, and L929 cell lines. The procedure can also be used to detect agents that modulate TNF activity. We demonstrated complete inhibition of rhTNF-alpha using monoclonal anti-human TNF-alpha antibody and determined that approximately 20 ng/mL antibody was sufficient to neutralize 50% of the biological activity of 250 pg/mL rhTNF-alpha in these cell lines. Reagents are added in a single step, followed by a 6- to 8-h incubation period, during which the cytokine exhibits its effects. There are no wash steps, and the assay is readily amenable to automation and high-throughput screening procedures.
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Affiliation(s)
- L J Jones
- Molecular Probes, Inc., Eugene, Oregon 97402-9165, USA
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KOBAYASHI M, SASAKI H, OGASAWARA K. Application of Redox Indicator to Monitor Development of Mouse Embryos Cultured In Vitro. J Reprod Dev 2001. [DOI: 10.1262/jrd.47.113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Masayuki KOBAYASHI
- Department of Biotechnology, Faculty of Bioresource Sciences, Akita Prefectural University
| | - Haruka SASAKI
- Department of Biotechnology, Faculty of Bioresource Sciences, Akita Prefectural University
| | - Kyoko OGASAWARA
- Department of Biotechnology, Faculty of Bioresource Sciences, Akita Prefectural University
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Jagannath C, Sepulveda E, Actor JK, Luxem F, Emanuele MR, Hunter RL. Effect of poloxamer CRL-1072 on drug uptake and nitric-oxide-mediated killing of Mycobacterium avium by macrophages. IMMUNOPHARMACOLOGY 2000; 48:185-97. [PMID: 10936516 DOI: 10.1016/s0162-3109(00)00203-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mycobacterium avium-intracellulare complex (MAI) are common pathogens of opportunistic infections that are naturally resistant to most antibiotics and develop acquired resistance rapidly. An experimental drug, poloxamer CRL-1072, was found to have two unusual properties: it synergistically enhanced the activity of several antibiotics against MAI even though it had little activity as a single agent and it had greater activity against MAI in macrophage culture or in mice than in broth culture. Studies were undertaken to investigate the mechanisms of these effects. CRL-1072 was taken up by MAI and enhanced the uptake of fluorescent-labeled streptomycin and erythromycin in broth culture. The labeled antibiotics had reduced activity so the relevance for naive antibiotics must be inferred. In culture with human U937 monocytoid cells, CRL-1072 became localized in phagosomes and promoted uptake of streptomycin. Finally, CRL-1072 was found to induce production of mRNA for inducible nitric oxide synthase (iNOS) and nitric oxide (NO) by U937 cells. The antimycobacterial effect in macrophages was reversed by the iNOS inhibitor N-monomethyl L-arginine (NMMA), suggesting that CRL-1072 promotes killing of MAI by inducing NO. These effects were induced by noncytotoxic concentrations of CRL-1072. These data suggest that the antimycobacterial mechanisms of CRL-1072 include enhancing the delivery of antibiotic to targets within MAI and enhancement of the ability of macrophages to kill ingested organisms.
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Affiliation(s)
- C Jagannath
- Department of Pathology and Laboratory Medicine, University of Texas-Houston Medical School, MSB2.137, 6431 Fannin, Houston, TX 77030, USA
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19
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Mu X, Azbill RD, Springer JE. Riluzole improves measures of oxidative stress following traumatic spinal cord injury. Brain Res 2000; 870:66-72. [PMID: 10869502 DOI: 10.1016/s0006-8993(00)02402-1] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Rats received a contusion injury to the spinal cord followed by treatment with riluzole (a glutamate release inhibitor, 8 mg/kg), methylprednisolone (MP 30 mg/kg) or both. At 4 h following injury, spinal cords were removed and synaptosomes prepared and examined using five measures of oxidative stress. Riluzole treatment was found to improve mitochondrial function, and enhance glutamate and glucose uptake. As expected, MP treatment was found to reduce lipid peroxidation, but also improved glutamate and glucose uptake. Interestingly, the combination treatment was found to be effective in improving all five measures of oxidative stress. The results of this study clearly demonstrate the potential beneficial effects of a combination approach in the treatment of oxidative stress events in traumatic spinal cord injury.
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Affiliation(s)
- X Mu
- Department of Anatomy and Neurobiology, Center for Spinal Cord and Brain Injury Research, University of Kentucky Medical Center, 800 Rose Street, Lexington, KY 40536-0084, USA
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20
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Yoshioka T, Iwamoto N, Tsukahara F, Irie K, Urakawa I, Muraki T. Anti-NO action of carvedilol in cell-free system and in vascular endothelial cells. Br J Pharmacol 2000; 129:1530-5. [PMID: 10742311 PMCID: PMC1571989 DOI: 10.1038/sj.bjp.0703241] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/1999] [Revised: 01/01/2000] [Accepted: 01/14/2000] [Indexed: 11/09/2022] Open
Abstract
1. Carvedilol, an adrenoceptor blocker with antioxidant activity, was studied for its ability to interact with NO in a cell-free condition and in an endothelial cell line (ECV304). 2. In a cell-free system, carvedilol attenuated NO-dependent reduction of carboxy-2-phenyl-4,4, 5,5-tetramethyl-imidazoline-1-oxyl-3-oxide induced by a NO donor, 1-hydroxy-2-oxo-3-(aminopropyl)-3-isopropyl-1-triazene (NOC5), which was determined by electron paramagnetic resonance (EPR) spectrometry. The EPR study also showed that nitrosylhaemoglobin formation in rat red blood cells by the addition of NO-saturated solution was attenuated by prior incubation with 0.1 - 10 microM carvedilol. 3. NO-induced fluorescence in 4,5-diaminofluorescein-2 diacethyl (DAF-2DA)-loaded ECV304 cells was attenuated by carvedilol but not by labetalol. The IC(50) of carvedilol for NOC5 or sodium nitroprusside-induced fluorescence of DAF-2DA in ECV304 cells was 1. 0x10(-7) M, which was similar to the reported IC(50) of carvedilol for the antioxidant effect. 4. Cell toxicity induced by a NO donor determined by the number of viable cells after 24 h treatment with 2-2'(hydroxynitrosohydrazino)bis-ethanamine was significantly attenuated by pretreatment with 1 microM carvedilol. 5. Both free and cell-associated carvedilol quenched NO. Because NO mediates both physiological and pathophysiological processes, NO quenching by the drug may have diverse clinical implications depending upon specific functions of local NO in tissues where carvedilol is distributed.
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Affiliation(s)
- T Yoshioka
- Department of Pharmacology, Tokyo Women's Medical University, School of Medicine, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan.
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21
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Springer JE, Azbill RD, Carlson SL. A rapid and sensitive assay for measuring mitochondrial metabolic activity in isolated neural tissue. BRAIN RESEARCH. BRAIN RESEARCH PROTOCOLS 1998; 2:259-63. [PMID: 9630663 DOI: 10.1016/s1385-299x(97)00045-7] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In the present study, we used the oxidation-reduction sensitive dye Alamar Blue, a fluorometric/colorimetric indicator of metabolic activity, as a tool for examining mitochondrial function in rat spinal cord synaptosomes. At 15 min following incubation, Alamar Blue fluorescence levels were found to increase by 3-fold, and could be detected in samples containing as little as 25 microg of protein. Alamar Blue is non-toxic, making it possible to obtain measures of the metabolic rate and the maximal functional capacity of mitochondria in a single sample. The findings of this study demonstrate that Alamar Blue fluorescence levels increased in a near linear fashion when samples were measured every 15 min for a period of 1 h. To document that the changes in Alamar Blue fluorescence are directly related to mitochondrial function, synaptosomes were pre-incubated with antimycin A (10 microM) or malonate (50 mM), both of which are potent inhibitors of mitochondrial function. Pretreatment with either compound significantly reduced the Alamar Blue fluorometric signal at all time points examined. These results provide evidence that Alamar Blue is a valuable analytical tool for examining mitochondrial function in synaptosomal preparations from neural tissue. Moreover, the properties of Alamar Blue are such that it provides a more sensitive and simpler indicator compared to indicators used in existing assays.
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Affiliation(s)
- J E Springer
- Department of Anatomy and Neurobiology, University of Kentucky Medical Center, 800 Rose Street, Lexington, KY 40536-0084, USA.
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22
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Nociari MM, Shalev A, Benias P, Russo C. A novel one-step, highly sensitive fluorometric assay to evaluate cell-mediated cytotoxicity. J Immunol Methods 1998; 213:157-67. [PMID: 9692848 DOI: 10.1016/s0022-1759(98)00028-3] [Citation(s) in RCA: 268] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
In this study, a fluorometric method using alamarBlue has been developed for detecting cell-mediated cytotoxicity in vitro. AlamarBlue is a non-toxic metabolic indicator of viable cells that becomes fluorescent upon mitochondrial reduction. Specific lysis of targets by effector cells is quantified by comparing the total number of viable cells in wells containing effector and targets together, with wells where target and effector cells were separately seeded. Cell-mediated cytotoxic activity by alloreactive T cells and natural killer cells has been detected using a novel application of the alamarBlue technique. The assay that we have developed to detect cell-mediated cytotoxicity is extremely sensitive and specific and requires a significant lower number of effector cells than the standard 51Cr assay. Since alamarBlue reagent is non-toxic to cells and the assay can be performed under sterile conditions, effector cells may be recovered at the end for further analysis or cell expansion, if desired. Direct comparison of cell-mediated cytotoxicity measured by the alamarBlue method with the standard 51Cr release assay revealed that the former method is as specific and more sensitive than the conventional assay. Moreover, very small inter and intra-assay variations have been observed for alamarBlue cytotoxicity assays. In conclusion, this study shows that the alamarBlue assay is an extremely sensitive, economical, simple and non-toxic procedure to evaluate cell-mediated cytotoxicity that yields accurate results using a limited number of effector cells. Furthermore, since this assay is a one-step procedure, and does not involve any risk for the personnel, it may be useful to analyze automatically cell-mediated cytotoxicity in a large number of samples.
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Affiliation(s)
- M M Nociari
- Division of Geriatrics, Cornell University Medical College, New York, NY 10021, USA
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23
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Momotani E, Watanabe S, Yoshihara K, Amano F. The effect of oligosaccharides on the production of tumor necrosis factor-alpha by macrophage-like cell line J774/JA-4. J Vet Med Sci 1998; 60:519-22. [PMID: 9592728 DOI: 10.1292/jvms.60.519] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Stimulation and modulation of tumor necrosis factor-alpha (TNF-alpha) production during treatment of the murine macrophage-like cell line J774/JA-4 with 25 oligosaccharides were studied. Direct stimulation of TNF-alpha production by oligosaccharides was measured with a cytotoxic assay using the L929 cell line. Twelve samples showed a significantly higher production (P < or = 0.01) of TNF-alpha than the controls. Modulation of TNF-alpha production by treatment with oligosaccharides, followed by stimulation with lipopolysaccharide (LPS) from E. coli, was examined using the L929 bioassay system. In three samples TNF-alpha production increased significantly, but in four samples, production was reduced significantly (P < or = 0.01). No samples showed modulation of growth or viability of L929 cells within the first 26 hr. The present results are useful in the application of these oligosaccharides which is potentially applicable in medical and food technology.
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Affiliation(s)
- E Momotani
- National Institute of Animal Health, Tsukuba, Japan
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24
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Shahan TA, Sorenson WG, Paulauskis JD, Morey R, Lewis DM. Concentration- and time-dependent upregulation and release of the cytokines MIP-2, KC, TNF, and MIP-1alpha in rat alveolar macrophages by fungal spores implicated in airway inflammation. Am J Respir Cell Mol Biol 1998; 18:435-40. [PMID: 9490662 DOI: 10.1165/ajrcmb.18.3.2856] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Inhalation of fungal spores has been shown to cause primary or secondary infection and respiratory inflammation and diseases such as allergic alveolitis, atopic asthma, and organic dust toxic syndrome, which are rarely reported in the absence of predisposing factors. Biochemical and molecular markers of inflammation were measured in rat bronchial alveolar lavage cells (> 95% macrophages) following stimulation with fungal spores isolated from pathogenic and nonpathogenic fungi that have been implicated in airway inflammation. The results of this study demonstrate that mRNA transcripts for the C-X-C branch of the PF4 superfamily are differentially upregulated over those of the C-C mediators in a time- and concentration-dependent manner. Macrophage inflammatory protein (MIP)-2 and KC were differentially upregulated over the acute phase inflammatory cytokines MIP-1alpha and tumor necrosis factor-alpha (TNF-alpha) in rat alveolar macrophages stimulated with fungal spores from Aspergillus candidus, Aspergillus niger, Eurotium amstelodami, and Cladosporium cladosporioides. Spores from Aspergillus terreus and Penicillium spinulosum failed to stimulate an increase of any cytokine mRNA, whereas those from Aspergillus fumigatus stimulated the upregulation of MIP-2, KC, TNF-alpha, and MIP-1alpha mRNAs. Over time, A. fumigatus stimulated increasing KC production until 24 h, when production levels increased slightly, then leveled off when measurements ceased at 36 h. Latex spheres stimulated modest amounts of MIP-2 and transforming growth factor-beta only. These observations suggest that the inflammatory cytokines MIP-2 and KC may be involved in the inflammation arising from the inhalation of fungal spores in a time- and concentration-dependent manner.
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Affiliation(s)
- T A Shahan
- Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Morgantown, West Virginia 26505, USA
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25
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Wu A, Zhang Y, Qin H, He Q. Antitumor effects induced by b7-1 gene modified EL-4 lymphoma cooperated with IL-2in vivo andin vitro. Chin J Cancer Res 1997. [DOI: 10.1007/bf02974969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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26
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Braut-Boucher F, Pichon J, Wantyghem J, Muriel MP, Giner M, Font J, Aubery M. Human keratinocyte models: Assessment of cell adhesion and dermotoxicity using fluorescent probes. Toxicol In Vitro 1997; 11:601-11. [DOI: 10.1016/s0887-2333(97)00067-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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27
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Azbill RD, Mu X, Bruce-Keller AJ, Mattson MP, Springer JE. Impaired mitochondrial function, oxidative stress and altered antioxidant enzyme activities following traumatic spinal cord injury. Brain Res 1997; 765:283-90. [PMID: 9313901 DOI: 10.1016/s0006-8993(97)00573-8] [Citation(s) in RCA: 224] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Glutamate-induced excitotoxicity involving the formation of reactive oxygen species (ROS) has been implicated in neuronal dysfunction and cell loss following ischemic and traumatic injury to the central nervous system (CNS). ROS are formed in mitochondria when energy metabolism is compromised, and are inactivated by the ROS scavengers superoxide dismutase (SOD), catalase, and glutathione (GSH). ROS can impair the function of several cellular components including proteins, nucleic acids, and lipids. In the present study, we measured indicators of mitochondrial metabolic activity, ROS formation, lipid peroxidation, and antioxidant enzyme activities in synaptosomes obtained from rat spinal cord at early times following traumatic injury. Mitochondrial metabolic activity was found to significantly decrease as early as 1 h following injury, and continued to be compromised over the remaining postinjury time points. ROS formation was found to be significantly increased at 4 and 24 h following injury, while lipid peroxidation levels were found to be significantly increased in the injured spinal cord at 1 and 24 h, but not 4 h following injury. SOD enzyme activity was unchanged at all postinjury time points, while catalase activity and GSH levels were significantly increased at 24 h following injury. These findings indicate that impaired mitochondrial function, ROS, and lipid peroxidation occur soon after traumatic spinal cord injury, while the compensatory activation of molecules important for neutralizing ROS occurs at later time points. Therapeutic strategies aimed at facilitating the actions of antioxidant enzymes or inhibiting ROS formation and lipid peroxidation in the CNS may prove beneficial in treating traumatic spinal cord injury, provided such treatments are initiated at early stages following injury.
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Affiliation(s)
- R D Azbill
- Department of Anatomy and Neurobiology, University of Kentucky Medical Center, Lexington 40536-0084, USA
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28
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Stangel M, Schumacher HC, Ruprecht K, Boegner F, Marx P. Immunoglobulins for intravenous use inhibit TNF alpha cytotoxicity in vitro. Immunol Invest 1997; 26:569-78. [PMID: 9399100 DOI: 10.3109/08820139709088541] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Intravenous immunoglobulins (IVIg) have been used as an immunomodulatory therapy in a variety of diseases. Several mechanisms of action have been proposed, one of which is interference with the cytokine network. We have investigated the effect of IVIg on the cytotoxicity of human TNF alpha. IVIg was capable of protecting L929 fibroblasts from TNF alpha induced cell death. This effect was not species specific and was mediated by both the Fc and the Fab portion of immunoglobulins. Since the effect was also seen when IVIg was added after the removal of TNF alpha from the culture medium, it seems to be independent of the interaction of TNF alpha with its receptor. We conclude that IVIg either act on some point of the TNF alpha signalling pathway or influence the cell cycle unspecifically. The cytoprotective effect of IVIg potentially could contribute to the beneficial effect described for various diseases.
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Affiliation(s)
- M Stangel
- Department of Neurology, Universitätsklinikum Benjamin Franklin, Freie Universität Berlin, Germany.
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29
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Yang HM, Ma JY, Castranova V, Ma JK. Effects of diesel exhaust particles on the release of interleukin-1 and tumor necrosis factor-alpha from rat alveolar macrophages. Exp Lung Res 1997; 23:269-84. [PMID: 9184793 DOI: 10.3109/01902149709087372] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The effects of diesel exhaust particles (DEP) and their components (washed dust and methanol extracts) on the release of proinflammatory cytokines, interleukin-I (IL-1), and tumor necrosis factor-alpha (TNF-alpha) by alveolar macrophages (AM) were investigated. Rat AM were incubated with 0, 5, 10, 20, 50, or 100 micrograms/10(6) AM/mL of DEP, methanol-washed DEP, or equivalent concentrations of DEP methanol extracts at 37 degrees C for 24 h. AM-conditioned supernatants were collected and assayed for the activities of IL-1 and TNF-alpha. At high concentrations both DEP and DEP methanol extracts were shown to increase IL-I-like activity secreted by AM, whereas methanol-washed DEP had no effect. Neither DEP, methanol-washed DEP, nor DEP methanol extracts was found to stimulate the secretion of TNF-alpha. The effects of DEP on the release of IL-I and TNF-alpha by lipopolysaccharide (LPS)- or interferon-gamma (IFN-gamma)-primed AM were also studied. AM were preincubated with various concentrations of DEP for 2 h, then challenged with either 0.1 microgram/mL of LPS or 5 units/mL of IFN-gamma. DEP inhibited LPS-stimulated production of H-I and TNF-alpha. These inhibitory effects were attributed to the organic extracts of DEP. In contrast, stimulation of AM production of TNF-alpha by IFN-gamma was not affected by DEP exposure. In summary, evidence that DEP enhanced the production of IL-1 by AM in vitro suggests that this proinflammatory cytokine may play a role in the pulmonary response to DEP inhalation. The suppressive response of DEP-pretreated AM to LPS stimulation may be a contributing factor to the impairment of pulmonary defense system after prolonged DEP exposure.
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Affiliation(s)
- H M Yang
- School of Pharmacy, West Virginia University, Morgantown 26506-9530, USA
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30
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Jonsson KB, Frost A, Larsson R, Ljunghall S, Ljunggren O. A new fluorometric assay for determination of osteoblastic proliferation: effects of glucocorticoids and insulin-like growth factor-I. Calcif Tissue Int 1997; 60:30-6. [PMID: 9030477 DOI: 10.1007/s002239900182] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A novel fluorometric proliferation assay, AlamarBlue (AB), was used to study the proliferative capacity of isolated human osteoblasts (hOBs). AB is an oxidation-reduction indicator that yields a fluorescent signal in response to metabolic activity. The assay was performed by replacing the experiment media in a microtiter plate with a 10% AB solution and measuring fluorescence after a 3-8-hour incubation. The assay was optimized with respect to incubation time, cell density, and AB concentration. When the results of the AB assay were compared with cell counting in a Bürker chamber there were consistently good correlations (r > 0.9), regardless of the agonist with which the cells were treated. The mean intraassay coefficient of variance (CV) values were 9.9-11.8% in experiments where osteoblasts were treated for 12 days with insulin-like growth factor-I (IGF-I; 100 nM), or dexamethasone (1 micro;M). IGF-I dose dependently, at and above 1 nM, stimulated proliferation of hOBs. This effect was detectable after 3 days and reached 130-140% of untreated controls after 12 days in culture. The effects of dexamethasone (DEX) on the proliferation rate of hOBs were more complex. In short-term cultures, 3 days, DEX dose dependently stimulated proliferation. However, at and above 6 days, DEX exerted a biphasic effect, with stimulation seen at 1-10 nM and a marked inhibition of cell proliferation at and above 100 nM. dexamethasone, hydrocortisone, prednisolone, and deflazacort had almost identical biphasic effects on osteoblastic proliferation in 12 day cultures with a stimulation seen at 1-10 nM, and a marked inhibition down to 50-60% of untreated controls at and above 100 nM. When IGF-I (0. 1-100 nM; 12 day culture) was combined with different doses of DEX, IGF-I still dose dependently stimulated the proliferation rate in hOBs regardless of the amount of DEX added. The stimulatory effect of DEX (10 nM, 12 days culture) was additive to the effect of 100 nM IGF-I. We conclude that AB is an easy and reliable assay for osteoblastic cell proliferation, well suited for large scale studies of cell growth using small amounts of cells, and that IGF-I partly reverses the glucocorticoid-induced inhibition of osteoblastic proliferation.
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Affiliation(s)
- K B Jonsson
- Department of Internal Medicine, University of Uppsala, S-751 85 Uppsala, Sweden
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31
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Liu J, Squibb KS, Akkerman M, Nordberg GF, Lipsky M, Fowler BA. Cytotoxicity, zinc protection, and stress protein induction in rat proximal tubule cells exposed to cadmium chloride in primary cell culture. Ren Fail 1996; 18:867-82. [PMID: 8948521 DOI: 10.3109/08860229609047713] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Primary cell culture was utilized to study the relationships between stress protein induction by zinc in vivo and cadmium toxicity in vitro. Effects of cadmium on cell viability were evaluated by the alamar blue assay, in conjunction with the ultrastructural morphology of cells by transmission electron microscopy. The expression of stress protein gene products was evaluated by 35S two-dimensional gel electrophoresis. The results showed cytotoxicity of CdCl2 at and above 129 microM (14.55 micrograms cadmium/mL medium) following 4 h of exposure. Prior zinc administration (20 mg zinc/kg, s.c., two daily doses) in vivo significantly protected the cells in vitro as demonstrated by improved cell viability. The 35S labeling of proteins induced by CdCl2 exposure clearly demonstrated for the first time that gene product of the 70-kDa family was induced in cultured rat proximal tubule cells which are the target cells for cadmium toxicity in vivo. Zinc in vivo pretreatment of animals induced proteins in the 90-, 70-, and 38-kDa families, which may act together with metallothionein to protect cells against cadmium toxicity. The results also indicate that the protective effect of zinc remains after the cells have been put in culture and thus provides a system in which we can study the changes that occur as a result of zinc exposure that decreases cadmium toxicity.
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Affiliation(s)
- J Liu
- Department of Environmental Medicine, Umeå University, Sweden
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32
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Greenwald RB, Gilbert CW, Pendri A, Conover CD, Xia J, Martinez A. Drug delivery systems: water soluble taxol 2'-poly(ethylene glycol) ester prodrugs-design and in vivo effectiveness. J Med Chem 1996; 39:424-31. [PMID: 8558510 DOI: 10.1021/jm950475e] [Citation(s) in RCA: 181] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Water soluble 2'-taxol poly(ethylene glycol) (PEG) esters have been synthesized and shown to function in vitro as prodrugs. However, in vivo experiments clearly establish that in order for these prodrugs to behave in a predictable fashion, the molecular weight of PEG must be of such magnitude so as to maintain a t1/2(circulation) > t1/2(hydrolysis). When PEG derivatives of molecular weight approximately 40 kDa were employed with paclitaxel, ca. 4% by weight of paclitaxel was carried by the water soluble prodrug form, and equivalent in vivo toxicity and increased life expectancy in the P388-treated mouse was observed. An effective method for prescreening prodrugs was found to be the acute murine lethality, which reflects the equivalency of the solubilized transport form and the native drug.
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