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Branchini BR, Southworth TL, Fontaine DM, Kohrt D, Welcome FS, Florentine CM, Henricks ER, DeBartolo DB, Michelini E, Cevenini L, Roda A, Grossel MJ. Red-emitting chimeric firefly luciferase for in vivo imaging in low ATP cellular environments. Anal Biochem 2017; 534:36-39. [PMID: 28687486 DOI: 10.1016/j.ab.2017.07.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 06/30/2017] [Accepted: 07/03/2017] [Indexed: 12/12/2022]
Abstract
Beetle luciferases have been adapted for live cell imaging where bioluminescence is dependent on the cellular availability of ATP, O2, and added luciferin. Previous Photinus pyralis red-emitting variants with high Km values for ATP have performed disappointingly in live cells despite having much higher relative specific activities than enzymes like Click Beetle Red (CBR). We engineered a luciferase variant PLR3 having a Km value for ATP similar to CBR and ∼2.6-fold higher specific activity. The red-emitting PLR3 was ∼2.5-fold brighter than CBR in living HEK293T and HeLa cells, an improvement consistent with the importance of the Km value in low ATP environments.
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Cevenini L, Calabretta MM, Lopreside A, Branchini BR, Southworth TL, Michelini E, Roda A. Bioluminescence Imaging of Spheroids for High‐throughput Longitudinal Studies on 3D Cell Culture Models. Photochem Photobiol 2017; 93:531-535. [DOI: 10.1111/php.12718] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 12/11/2016] [Indexed: 12/12/2022]
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Ferri M, Graen-Heedfeld J, Bretz K, Guillon F, Michelini E, Calabretta MM, Lamborghini M, Gruarin N, Roda A, Kraft A, Tassoni A. Peptide Fractions Obtained from Rice By-Products by Means of an Environment-Friendly Process Show In Vitro Health-Related Bioactivities. PLoS One 2017; 12:e0170954. [PMID: 28125712 PMCID: PMC5268429 DOI: 10.1371/journal.pone.0170954] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 01/13/2017] [Indexed: 11/30/2022] Open
Abstract
Recently, the isolation of new health-related bioactive molecules derived from agro-food industrial by-products by means of environment-friendly extraction processes has become of particular interest. In the present study, a protein by-product from the rice starch industry was hydrolysed with five commercial proteolytic enzymes, avoiding the use of solvents or chemicals. The digestion processes were optimised, and the digestates were separated in fractions with four different molecular weight ranges by using a cross-flow membrane filtration technique. Total hydrolysates and fractions were tested in vitro for a wide range of biological activities. For the first time rice-derived peptides were assayed for anti-tyrosinase, anti-inflammatory, cytotoxicity and irritation capacities. Antioxidant and anti-hypertensive activities were also evaluated. Protamex, Alcalase and Neutrase treatments produced peptide fractions with valuable bioactivities without resulting cytotoxic or irritant. Highest levels of bioactivity were detected in Protamex-derived samples, followed by samples treated with Alcalase. Based on the present results, a future direct exploitation of isolated peptide fractions in the nutraceutical, functional food and cosmetic industrial fields may be foreseen.
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Roda A, Michelini E, Zangheri M, Di Fusco M, Calabria D, Simoni P. Smartphone-based biosensors: A critical review and perspectives. Trends Analyt Chem 2016. [DOI: 10.1016/j.trac.2015.10.019] [Citation(s) in RCA: 331] [Impact Index Per Article: 41.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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D'Alessandro S, Camarda G, Corbett Y, Siciliano G, Parapini S, Cevenini L, Michelini E, Roda A, Leroy D, Taramelli D, Alano P. A chemical susceptibility profile of the Plasmodium falciparum transmission stages by complementary cell-based gametocyte assays. J Antimicrob Chemother 2016; 71:1148-58. [PMID: 26888912 DOI: 10.1093/jac/dkv493] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 12/19/2015] [Indexed: 01/02/2023] Open
Abstract
OBJECTIVES As most available antimalarial drugs are ineffective against the Plasmodium falciparum transmission stages, new drugs against the parasite's gametocytes are urgently needed to combat malaria globally. The unique biology of gametocytes requires assays that need to be specific, to faithfully monitor anti-gametocyte activity, and to be easy to perform, cheap and scalable to high-throughput screening (HTS). METHODS We developed an HTS cell-based assay with P. falciparum gametocytes specifically expressing a potent luciferase. To confirm HTS hit activity for several parasite genotypes, the luciferase assay and the gametocyte lactate dehydrogenase (LDH) assay, usable on any parasite isolate, were compared by screening antimalarial drugs and determining IC50 values of anti-gametocyte hits from the 'Malaria Box' against early- and late-stage gametocytes. RESULTS Comparison of the two assays, conducted on the early and on late gametocyte stages, revealed an excellent correlation (R(2) > 0.9) for the IC50 values obtained by the respective readouts. Differences in susceptibility to drugs and compounds between the two parasite developmental stages were consistently measured in both assays. CONCLUSIONS This work indicates that the luciferase and gametocyte LDH assays are interchangeable and that their specific advantages can be exploited to design an HTS pipeline leading to new transmission-blocking compounds. Results from these assays consistently defined a gametocyte chemical susceptibility profile, relevant to the planning of future drug discovery strategies.
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Roda A, Mirasoli M, Michelini E, Di Fusco M, Zangheri M, Cevenini L, Roda B, Simoni P. Progress in chemical luminescence-based biosensors: A critical review. Biosens Bioelectron 2016; 76:164-79. [DOI: 10.1016/j.bios.2015.06.017] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 06/03/2015] [Accepted: 06/07/2015] [Indexed: 12/12/2022]
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Branchini BR, Southworth TL, Fontaine DM, Kohrt D, Talukder M, Michelini E, Cevenini L, Roda A, Grossel MJ. An enhanced chimeric firefly luciferase-inspired enzyme for ATP detection and bioluminescence reporter and imaging applications. Anal Biochem 2015; 484:148-53. [PMID: 26049097 PMCID: PMC4496250 DOI: 10.1016/j.ab.2015.05.020] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 05/26/2015] [Accepted: 05/29/2015] [Indexed: 10/23/2022]
Abstract
Firefly luciferases, which emit visible light in a highly specific ATP-dependent process, have been adapted for a variety of applications, including gene reporter assays, whole-cell biosensor measurements, and in vivo imaging. We previously reported the approximately 2-fold enhanced activity and 1.4-fold greater bioluminescence quantum yield properties of a chimeric enzyme that contains the N-domain of Photinus pyralis luciferase joined to the C-domain of Luciola italica luciferase. Subsequently, we identified 5 amino acid changes based on L. italica that are the main determinants of the improved bioluminescence properties. Further engineering to enhance thermal and pH stability produced a novel luciferase called PLG2. We present here a systematic comparison of the spectral and physical properties of the new protein with P. pyralis luciferase and demonstrate the potential of PLG2 for use in assays based on the detection of femtomole levels of ATP. In addition, we compared the performance of a mammalian codon-optimized version of the cDNA for PLG2 with the luc2 gene in HEK293T cells. Using an optimized low-cost assay system, PLG2 activity can be monitored in mammalian cell lysates and living cells with 4.4-fold and approximately 3.0-fold greater sensitivity, respectively. PLG2 could be an improved alternative to Promega's luc2 for reporter and imaging applications.
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Roda A, Guardigli M, Calabria D, Calabretta MM, Cevenini L, Michelini E. A 3D-printed device for a smartphone-based chemiluminescence biosensor for lactate in oral fluid and sweat. Analyst 2014; 139:6494-501. [DOI: 10.1039/c4an01612b] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Cevenini L, Camarda G, Michelini E, Siciliano G, Calabretta MM, Bona R, Kumar TRS, Cara A, Branchini BR, Fidock DA, Roda A, Alano P. Multicolor bioluminescence boosts malaria research: quantitative dual-color assay and single-cell imaging in Plasmodium falciparum parasites. Anal Chem 2014; 86:8814-21. [PMID: 25102353 PMCID: PMC4151787 DOI: 10.1021/ac502098w] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
![]()
New
reliable and cost-effective antimalarial drug screening assays
are urgently needed to identify drugs acting on different stages of
the parasite Plasmodium falciparum,
and particularly those responsible for human-to-mosquito transmission,
that is, the P. falciparum gametocytes.
Low Z′ factors, narrow dynamic ranges, and/or
extended assay times are commonly reported in current gametocyte assays
measuring gametocyte-expressed fluorescent or luciferase reporters,
endogenous ATP levels, activity of gametocyte enzymes, or redox-dependent
dye fluorescence. We hereby report on a dual-luciferase gametocyte
assay with immature and mature P. falciparum gametocyte stages expressing red and green-emitting luciferases
from Pyrophorus plagiophthalamus under
the control of the parasite sexual stage-specific pfs16 gene promoter. The assay was validated with reference antimalarial
drugs and allowed to quantitatively and simultaneously measure stage-specific
drug effects on parasites at different developmental stages. The optimized
assay, requiring only 48 h incubation with drugs and using a cost-effective
luminogenic substrate, significantly reduces assay cost and time in
comparison to state-of-the-art analogous assays. The assay had a Z′ factor of 0.71 ± 0.03, and it is suitable
for implementation in 96- and 384-well microplate formats. Moreover,
the use of a nonlysing d-luciferin substrate significantly
improved the reliability of the assay and allowed one to perform,
for the first time, P. falciparum bioluminescence
imaging at single-cell level.
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Roda A, Michelini E, Cevenini L, Calabria D, Calabretta MM, Simoni P. Integrating biochemiluminescence detection on smartphones: mobile chemistry platform for point-of-need analysis. Anal Chem 2014; 86:7299-304. [PMID: 25017302 DOI: 10.1021/ac502137s] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
In this paper, we report, for the first time, the use of a smartphone to image and quantify biochemiluminescence coupled biospecific enzymatic reactions to detect analytes in biological fluids. Using low-cost three-dimensional (3D) printing technology, we fabricated a smartphone accessory and a minicartridge for hosting biospecific reactions. As a proof-of-principle, we report two assays: a bioluminescence assay for total bile acids using 3α-hydroxyl steroid dehydrogenase coimmobilized with bacterial luciferase system and a chemiluminescence assay for total cholesterol using cholesterol esterase/cholesterol oxidase coupled with the luminol-H2O2-horseradish peroxidase system. These assays can be performed within 3 min in a very straightforward manner and provided adequate analytical performance for the analysis of total cholesterol in serum (limit of detection (LOD) = 20 mg/dL) and total bile acid in serum and oral fluid (LOD = 0.5 μmol/L) with a reasonable accuracy and precision. Smartphone-based biochemiluminescence detection could be thus applied to a variety of clinical chemistry assays.
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Michelini E, Cevenini L, Calabretta MM, Calabria D, Roda A. Exploiting in vitro and in vivo bioluminescence for the implementation of the three Rs principle (replacement, reduction, and refinement) in drug discovery. Anal Bioanal Chem 2014; 406:5531-9. [PMID: 24908412 DOI: 10.1007/s00216-014-7925-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 05/22/2014] [Accepted: 05/23/2014] [Indexed: 12/21/2022]
Abstract
Bioluminescence-based analytical tools are suitable for high-throughput and high-content screening assays, finding widespread application in several fields related to the drug discovery process. Cell-based bioluminescence assays, because of their peculiar advantages of predictability, possibility of automation, multiplexing, and miniaturization, seem the most appealing tool for the high demands of the early stages of drug screening. Reporter gene technology and the bioluminescence resonance energy transfer principle are widely used, and receptor binding studies of new agonists/antagonists for a variety of human receptors expressed in different cell lines can be performed. Moreover, bioluminescence can be used for in vitro and in vivo real-time monitoring of pathophysiological processes within living cells and small animals. New luciferases and substrates have recently arrived on the market, further expanding the spectrum of applications. A new generation of probes are also emerging that promise to revolutionize the preclinical imaging market. This formidable toolbox is demonstrated to facilitate the implementation of the three Rs principle in the early drug discovery process, in compliance with ethical and responsible research to reduce cost and improve the reliability and predictability of results.
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Mirasoli M, Guardigli M, Michelini E, Roda A. Recent advancements in chemical luminescence-based lab-on-chip and microfluidic platforms for bioanalysis. J Pharm Biomed Anal 2014; 87:36-52. [DOI: 10.1016/j.jpba.2013.07.008] [Citation(s) in RCA: 122] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 07/08/2013] [Accepted: 07/08/2013] [Indexed: 01/27/2023]
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Roda A, Cevenini L, Borg S, Michelini E, Calabretta MM, Schüler D. Bioengineered bioluminescent magnetotactic bacteria as a powerful tool for chip-based whole-cell biosensors. LAB ON A CHIP 2013; 13:4881-4889. [PMID: 24193113 DOI: 10.1039/c3lc50868d] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
This paper describes the generation of genetically engineered bioluminescent magnetotactic bacteria (BL-MTB) and their integration into a microfluidic analytical device to create a portable toxicity detection system. Magnetospirillum gryphiswaldense strain MSR-1 was bioengineered to constitutively express a red-emitting click beetle luciferase whose bioluminescent signal is directly proportional to bacterial viability. The magnetic properties of these bacteria have been exploited as "natural actuators" to transfer the cells in the chip from the reaction to the detection area, optimizing the chip's analytical performance. A robust and cost-effective biosensor for the evaluation of sample toxicity, named MAGNETOX, based on lens-free contact imaging detection, has been developed. A microfluidic chip has been fabricated using multilayered black and transparent polydimethyl siloxane (PDMS) in which BL-MTB are incubated for 30 min with the sample, then moved by microfluidics, trapped, and concentrated in detection chambers by an array of neodymium-iron-boron magnets. The chip is placed in contact with a cooled CCD via a fiber optic taper to perform quantitative bioluminescence imaging after addition of luciferin substrate. A model toxic compound (dimethyl sulfoxide, DMSO) and a bile acid (taurochenodeoxycholic acid, TCDCA) were used to investigate the analytical performance of the MAGNETOX. Incubation with DMSO and TCDCA drastically reduces the bioluminescent signal in a dose-related manner. The generation of bacteria that are both magnetic and bioluminescent combines the advantages of easy 2D cell handling with ultra sensitive detection, offering undoubted potential to develop cell-based biosensors integrated into microfluidic chips.
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Michelini E, Cevenini L, Calabretta MM, Spinozzi S, Camborata C, Roda A. Field-deployable whole-cell bioluminescent biosensors: so near and yet so far. Anal Bioanal Chem 2013; 405:6155-63. [DOI: 10.1007/s00216-013-7043-6] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 04/26/2013] [Accepted: 05/02/2013] [Indexed: 12/24/2022]
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Ekström L, Cevenini L, Michelini E, Schulze J, Thörngren JO, Belanger A, Guillemette C, Garle M, Roda A, Rane A. Testosterone challenge and androgen receptor activity in relation to UGT2B17 genotypes. Eur J Clin Invest 2013; 43:248-55. [PMID: 23294483 DOI: 10.1111/eci.12037] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 11/27/2012] [Indexed: 11/29/2022]
Abstract
BACKGROUND We investigated the androgen receptor (AR) bioluminescense response in serum and urine before and after testosterone challenge in different genotypes of the UGT2B17 enzyme, which catalyses testosterone glucuronidation. MATERIAL AND METHODS The androgen receptor activity was determined using a yeast-based bioluminescence assay. The androgens were analysed using LC-MS/MS, and the individuals were genotyped for UGT2B17 deletion polymorphism using real-time polymerase chain reaction. RESULTS The serum concentrations of testosterone and dihydrotestosterone (DHT) were markedly elevated on days 2 and 4 and were still above baseline on day 15 after a dose of 500 mg testosterone enanthate. The androgenic activity in serum increased in parallel and correlated with the hormone concentrations and remained above baseline on day 15. The urinary androgenic activity increased 4-5-fold and was closely related to the unconjugated testosterone and independent of the UGT2B17 genotype. CONCLUSIONS The AR assay may serve as a complement to the urinary testosterone/epitestosterone (T/E) doping test, because this is profoundly influenced by the UGT2B17 deletion polymorphism. It may also be useful for detection of other illicit androgens in sports, or in the society, or for monitoring and diagnostics of androgen-related disorders.
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Michelini E, Donati M, Aldini R, Cevenini L, Mezzanotte L, Nardini P, Foschi C, Zvi IB, Cevenini M, Montagnani M, Marangoni A, Roda A, Cevenini R. Dual-color bioluminescent assay using infected HepG2 cells sheds new light on Chlamydia pneumoniae and human cytomegalovirus effects on human cholesterol 7α-hydroxylase (CYP7A1) transcription. Anal Biochem 2012; 430:92-6. [DOI: 10.1016/j.ab.2012.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Revised: 07/27/2012] [Accepted: 08/03/2012] [Indexed: 12/18/2022]
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Michelini E, Lonardo A, Ballestri S, Costantini M, Caporali C, Bonati ME, Bertolotti M, Iori R, Loria P. Is cholangiocarcinoma another complication of insulin resistance: a report of three cases. Metab Syndr Relat Disord 2012; 5:194-202. [PMID: 18370827 DOI: 10.1089/met.2006.0018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Cholangiocarcinoma is the second most common primary liver cancer, and the number of cases of intrahepatic cholangiocarcinoma (ICC) have been steadily increasing worldwide. Although the reasons for this surge are unknown, insulin resistance (IR) could be a risk factor, similar to what has been reported for other cancers. CASE REPORT We report on 3 cases of ICC arising in subjects sharing IR as an underlying risk factor. Case 1 was an obese and dyslipidemic patient with NAFLD. The second and the third patients were affected by type 2 diabetes. CONCLUSIONS Evidence for a link between IR and onset of cholangiocarcinoma in our patients rests on three lines of evidence: epidemiological, biological, and exclusion of others risk factors. Studies are needed to confirm our hypothesis that IR is a risk factor for the development of ICC.
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Michelini E. Khalid Shah (Ed.): Molecular imaging. Methods and protocols. Anal Bioanal Chem 2012. [DOI: 10.1007/s00216-012-6064-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Nazari M, Emamzadeh R, Hosseinkhani S, Cevenini L, Michelini E, Roda A. Renilla luciferase-labeled Annexin V: a new probe for detection of apoptotic cells. Analyst 2012; 137:5062-70. [DOI: 10.1039/c2an35741k] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Roda A, Roda B, Cevenini L, Michelini E, Mezzanotte L, Reschiglian P, Hakkila K, Virta M. Analytical strategies for improving the robustness and reproducibility of bioluminescent microbial bioreporters. Anal Bioanal Chem 2011; 401:201-11. [PMID: 21603915 DOI: 10.1007/s00216-011-5091-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2011] [Revised: 05/04/2011] [Accepted: 05/09/2011] [Indexed: 11/30/2022]
Abstract
Whole-cell bioluminescent (BL) bioreporter technology is a useful analytical tool for developing biosensors for environmental toxicology and preclinical studies. However, when applied to real samples, several methodological problems prevent it from being widely used. Here, we propose a methodological approach for improving its analytical performance with complex matrix. We developed bioluminescent Escherichia coli and Saccharomyces cerevisiae bioreporters for copper ion detection. In the same cell, we introduced two firefly luciferases requiring the same luciferin substrate emitting at different wavelengths. The expression of one was copper ion specific. The other, constitutively expressed, was used as a cell viability internal control. Engineered BL cells were characterized using the noninvasive gravitational field-flow fractionation (GrFFF) technique. Homogeneous cell population was isolated. Cells were then immobilized in a polymeric matrix improving cell responsiveness. The bioassay was performed in 384-well black polystyrene microtiter plates directly on the sample. After 2 h of incubation at 37 °C and the addition of the luciferin, we measured the emitted light. These dual-color bioreporters showed more robustness and a wider dynamic range than bioassays based on the same strains with a single reporter gene and that uses a separate cell strain as BL control. The internal correction allowed to accurately evaluate the copper content even in simulated toxic samples, where reduced cell viability was observed. Homogenous cells isolated by GrFFF showed improvement in method reproducibility, particularly for yeast cells. The applicability of these bioreporters to real samples was demonstrated in tap water and wastewater treatment plant effluent samples spiked with copper and other metal ions.
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Roda A, Cevenini L, Michelini E, Branchini BR. A portable bioluminescence engineered cell-based biosensor for on-site applications. Biosens Bioelectron 2011; 26:3647-53. [PMID: 21388801 DOI: 10.1016/j.bios.2011.02.022] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Revised: 02/02/2011] [Accepted: 02/12/2011] [Indexed: 11/28/2022]
Abstract
We have developed a portable biosensing device based on genetically engineered bioluminescent (BL) cells. Cells were immobilized on a 4 × 3 multiwell cartridge using a new biocompatible matrix that preserved their vitality. Using a fiber optic taper, the cartridge was placed in direct contact with a cooled CCD sensor to image and quantify the BL signals. Yeast and bacterial cells were engineered to express recognition elements, whose interaction with the analyte led to luciferase expression, via reporter gene technology. Three different biosensors were developed. The first detects androgenic compounds using yeast cells carrying a green-emitting P. pyralis luciferase regulated by the human androgen receptor and a red mutant of the same species as internal vitality control. The second biosensor detects two classes of compounds (androgens and estrogens) using yeast strains engineered to express green-or red-emitting mutant firefly luciferases in response to androgens or estrogens, respectively. The third biosensor detects lactose analogue isopropyl β-d-1-thiogalactopyranoside using two E. coli strains. One strain exploits the lac operon as recognition element for the expression of P. pyralis luciferase. The other strain serves as a vitality control expressing Gaussia princeps luciferase, which requires a different luciferin substrate. The immobilized cells were stable for up to 1 month. The analytes could be detected at nanomolar levels with good precision and accuracy when the specific signal was corrected using the internal vitality control. This portable device can be used for on-site multiplexed bioassays for different compound classes.
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Michelini E, Cevenini L, Mezzanotte L, Coppa A, Mirasoli M, Roda A. Bioluminescent genetically engineered cells for biosensing applications. J Biotechnol 2010. [DOI: 10.1016/j.jbiotec.2010.08.505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Roda A, Mezzanotte L, Aldini R, Michelini E, Cevenini L. A new gastric-emptying mouse model based on in vivo non-invasive bioluminescence imaging. Neurogastroenterol Motil 2010; 22:1117-e288. [PMID: 20546505 DOI: 10.1111/j.1365-2982.2010.01535.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND Different techniques were used to assess gastric emptying (GE) in small animals; most of them require sophisticated equipment, animal sacrifice and are expensive. In the present investigation a simple, non-invasive method based on bioluminescence imaging (BLI) is reported to study GE, using light-emitting Escherichia coli cells as a marker of the gastric content. METHODS A new thermostable red-emitting luciferase was chosen as reporter gene to transform E. coli cells. Bioluminescent (BL) bacteria were administered to fasting mice, after a solid meal, and in response to different doses of metoclopramide (MET) and hyoscine butylbromide (HY). Bioluminescence imaging allowed to evaluate the real time 2D spatial and temporal distribution of bacteria along the gastrointestinal tract in animals and to calculate GE rate in basal conditions and following pharmacological stimulation. KEY RESULTS The administered BL bacteria were easily imaged and localized in the stomach and subsequently followed in the duodenum and upper intestine allowing to accurately calculate GE. Gastric emptying after the test meal was significantly slower (T(1/2) 16 ± 3 min) than that obtained in fasting conditions (T(1/2) 2 ± 1 min); administration of HY (1 mg kg(-1) b.w.) significantly (P < 0.05) increased T(1/2) that was delayed up to 25 ± 4 min; MET (1 mg kg(-1) b.w.) significantly (P < 0.05) accelerated T(1/2), that was achieved within 8 ± 2 min. CONCLUSION & INFERENCES The reported model is simple, inexpensive, reliable, sensitive and accurate; it can detect both acceleration and slowdown of GE. The model is useful in the investigation of new drug-induced alterations of gastric motility allowing to reduce the number of experimental animals.
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Michelini E, Cevenini L, Mezzanotte L, Coppa A, Roda A. Cell-based assays: fuelling drug discovery. Anal Bioanal Chem 2010; 398:227-38. [PMID: 20623273 DOI: 10.1007/s00216-010-3933-z] [Citation(s) in RCA: 144] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Revised: 06/16/2010] [Accepted: 06/16/2010] [Indexed: 12/15/2022]
Abstract
It has been estimated that over a billion dollars in resources can be consumed to obtain clinical approval, and only a few new chemical entities are approved by the US Food and Drug Administration (FDA) each year. Therefore it is of utmost importance to obtain the maximum amount of information about biological activity, toxicological profile, biochemical mechanisms, and off-target interactions of drug-candidate leads in the earliest stages of drug discovery. Cell-based assays, because of their peculiar advantages of predictability, possibility of automation, multiplexing, and miniaturization, seem the most appealing tool for the high demands of the early stages of the drug-discovery process. Nevertheless, cellular screening, relying on different strategies ranging from reporter gene technology to protein fragment complementation assays, still presents a variety of challenges. This review focuses on main advantages and limitations of different cell-based approaches, and future directions and trends in this fascinating field.
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