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Evaluation of Pharmacological Rescue of Melanocortin-4 Receptor Nonsense Mutations by Aminoglycoside. Life (Basel) 2022; 12:life12111793. [PMID: 36362948 PMCID: PMC9697516 DOI: 10.3390/life12111793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/18/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022] Open
Abstract
The melanocortin-4 receptor (MC4R) is critical for central satiety regulation, therefore presenting a potent target for pharmacological obesity treatment. Melanocortin-4 receptor mutations prevalently cause monogenetic obesity. A possibility of overcoming stop mutations is aminoglycoside-mediated translational readthrough. Promising results were achieved in COS-7 cells, but data for human cell systems are still missing, so uncertainty surrounds this potential treatment. In transfected HEK-293 cells, we tested whether translational readthrough by aminoglycoside Geneticin combined with high-affinity ligand setmelanotide, which is effective in proopiomelanocortin or leptin receptor deficiency patients, is a treatment option for affected patients. Five MC4R nonsense mutants (W16X, Y35X_D37V, E61X, W258X, Q307X) were investigated. Confocal microscopy and cell surface expression assays revealed the importance of the mutations’ position within the MC4R. N-terminal mutants were marginally expressed independent of Geneticin treatment, whereas mutants with nonsense mutations in transmembrane helix 6 or helix 8 showed wild-type-like expression. For functional analysis, Gs and Gq/11 signaling were measured. N-terminal mutants (W16X, Y35X_D37V) showed no cAMP formation after challenge with alpha-MSH or setmelanotide, irrespective of Geneticin treatment. Similarly, Gs activation was almost impossible in W258X and Q307X with wild-type-like cell surface expression. Results for Gq/11 signaling were comparable. Based on our data, this approach improbably represents a therapeutic option.
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Tabatabaei M, Caetano FA, Pashee F, Ferguson SSG, Lagugné-Labarthet F. Tip-enhanced Raman spectroscopy of amyloid β at neuronal spines. Analyst 2018; 142:4415-4421. [PMID: 29090690 DOI: 10.1039/c7an00744b] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The early stages of Alzheimer's disease pathogenesis are thought to occur at the synapse level, since synapse loss can be directly correlated with memory dysfunction. Considerable evidence has suggested that amyloid beta (Aβ), a secreted proteolytic derivative of amyloid precursor protein, appears to be a critical factor in the early 'synaptic failure' that is observed in Alzheimer's disease pathogenesis. The identification of Aβ at neuronal spines with high spatial resolution and high surface specificity would facilitate unraveling the intricate effect of Aβ on synapse loss and its effect on neighboring neuronal connections. Here, tip-enhanced Raman spectroscopy was used to map the presence of Aβ aggregations in the vicinity of the spines exposed to Aβ preformed in vitro. Exposure to Aβ was of 1 and 6 hours. The intensity variation of selected vibrational modes of Aβ was mapped by TERS for different exposure times to Aβ. Of interest, we discuss the distinct contributions of the amide modes from Aβ that are enhanced by the TERS process and in particular the suppression of the amide I mode in the context of recently reported observations in the literature.
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Affiliation(s)
- Mohammadali Tabatabaei
- Department of Chemistry and Centre for Advanced Materials and Biomaterials, University of Western Ontario, London, ON, Canada N6A 5B7.
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Pashaee F, Tabatabaei M, Caetano FA, Ferguson SSG, Lagugné-Labarthet F. Tip-enhanced Raman spectroscopy: plasmid-free vs. plasmid-embedded DNA. Analyst 2016; 141:3251-8. [DOI: 10.1039/c6an00350h] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Wallace GQ, Tabatabaei M, Zuin MS, Workentin MS, Lagugné-Labarthet F. A nanoaggregate-on-mirror platform for molecular and biomolecular detection by surface-enhanced Raman spectroscopy. Anal Bioanal Chem 2015; 408:609-18. [PMID: 26521177 DOI: 10.1007/s00216-015-9142-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 10/07/2015] [Accepted: 10/21/2015] [Indexed: 12/13/2022]
Abstract
A nanoaggregate-on-mirror (NAOM) structure has been developed for molecular and biomolecular detection using surface-enhanced Raman spectroscopy (SERS). The smooth surface of the gold mirror allows for simple and homogeneous functionalization, while the introduction of the nanoaggregates enhances the Raman signal of the molecule(s) in the vicinity of the aggregate-mirror junction. This is evidenced by functionalizing the gold mirror with 4-nitrothiophenol, and the further addition of gold nanoaggregates promotes local SERS activity only in the areas with the nanoaggregates. The application of the NAOM platform for biomolecular detection is highlighted using glucose and H2O2 as molecules of interest. In both cases, the gold mirror is functionalized with 4-mercaptophenylboronic acid (4-MPBA). Upon exposure to glucose, the boronic acid moiety of 4-MPBA forms a cyclic boronate ester. Once the nanoaggregates are added to the surface, detection of glucose is possible without the use of an enzyme. This method of indirect detection provides a limit of detection of 0.05 mM, along with a linear range of detection from 0.1 to 15 mM for glucose, encompassing the physiological range of blood glucose concentration. The detection of H2O2 is achieved with optical inspection and SERS. The H2O2 interferes with the coating of the gold mirror, enabling qualitative detection by visual inspection. Simultaneously, the H2O2 reacts with the boronic acid to form a phenol, a change that is detected by SERS.
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Affiliation(s)
- Gregory Q Wallace
- Department of Chemistry, University of Western Ontario, 1151 Richmond St., London, Ontario, N6A 5B7, Canada.,Centre for Advanced Materials and Biomaterials Research, University of Western Ontario, 1151 Richmond St., London, Ontario, N6A 5B7, Canada
| | - Mohammadali Tabatabaei
- Department of Chemistry, University of Western Ontario, 1151 Richmond St., London, Ontario, N6A 5B7, Canada.,Centre for Advanced Materials and Biomaterials Research, University of Western Ontario, 1151 Richmond St., London, Ontario, N6A 5B7, Canada
| | - Mariachiara S Zuin
- Department of Chemistry, University of Western Ontario, 1151 Richmond St., London, Ontario, N6A 5B7, Canada.,Centre for Advanced Materials and Biomaterials Research, University of Western Ontario, 1151 Richmond St., London, Ontario, N6A 5B7, Canada
| | - Mark S Workentin
- Department of Chemistry, University of Western Ontario, 1151 Richmond St., London, Ontario, N6A 5B7, Canada.,Centre for Advanced Materials and Biomaterials Research, University of Western Ontario, 1151 Richmond St., London, Ontario, N6A 5B7, Canada
| | - François Lagugné-Labarthet
- Department of Chemistry, University of Western Ontario, 1151 Richmond St., London, Ontario, N6A 5B7, Canada. .,Centre for Advanced Materials and Biomaterials Research, University of Western Ontario, 1151 Richmond St., London, Ontario, N6A 5B7, Canada.
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Tabatabaei M, Wallace GQ, Caetano FA, Gillies ER, Ferguson SSG, Lagugné-Labarthet F. Controlled positioning of analytes and cells on a plasmonic platform for glycan sensing using surface enhanced Raman spectroscopy. Chem Sci 2015; 7:575-582. [PMID: 28791107 PMCID: PMC5519955 DOI: 10.1039/c5sc03332b] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 10/13/2015] [Indexed: 12/22/2022] Open
Abstract
Controlled analyte and cell positioning is enabled on a plasmonic platform with patterned fluorocarbon polymer thin films for SERS-based glycan sensing.
The rise of molecular plasmonics and its application to ultrasensitive spectroscopic measurements has been enabled by the rational design and fabrication of a variety of metallic nanostructures. Advanced nano and microfabrication methods are key to the development of such structures, allowing one to tailor optical fields at the sub-wavelength scale, thereby optimizing excitation conditions for ultrasensitive detection. In this work, the control of both analyte and cell positioning on a plasmonic platform is enabled using nanofabrication methods involving patterning of fluorocarbon (FC) polymer (C4F8) thin films on a plasmonic platform fabricated by nanosphere lithography (NSL). This provides the possibility to probe biomolecules of interest in the vicinity of cells using plasmon-mediated surface enhanced spectroscopies. In this context, we demonstrate the surface enhanced biosensing of glycan expression in different cell lines by surface enhanced Raman spectroscopy (SERS) on these plasmonic platforms functionalized with 4-mercaptophenylboronic acid (4-MPBA) as the Raman reporter. These cell lines include human embryonic kidney (HEK 293), C2C12 mouse myoblasts, and HeLa (Henrietta Lacks) cervical cancer cells. A distinct glycan expression is observed for cancer cells compared to other cell lines by confocal SERS mapping. This suggests the potential application of these versatile SERS platforms for differentiating cancerous from non-cancerous cells.
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Affiliation(s)
- Mohammadali Tabatabaei
- Department of Chemistry and Center for Advanced Materials and Biomaterials , University of Western Ontario , London , ON , Canada N6A 5B7 . ; ; Tel: +1 519 661 2111 ext. 81006
| | - Gregory Q Wallace
- Department of Chemistry and Center for Advanced Materials and Biomaterials , University of Western Ontario , London , ON , Canada N6A 5B7 . ; ; Tel: +1 519 661 2111 ext. 81006
| | - Fabiana A Caetano
- J. Allyn Taylor Centre for Cell Biology , Robarts Research Institute , Department of Physiology and Pharmacology , University of Western Ontario , 100 Perth Drive St. , London , ON , Canada N6A 5K8
| | - Elizabeth R Gillies
- Department of Chemistry and Center for Advanced Materials and Biomaterials , University of Western Ontario , London , ON , Canada N6A 5B7 . ; ; Tel: +1 519 661 2111 ext. 81006.,Department of Chemical and Biochemical Engineering , The University of Western Ontario , 1151 Richmond Street , London , Ontario , Canada N6A 5B9
| | - Stephen S G Ferguson
- J. Allyn Taylor Centre for Cell Biology , Robarts Research Institute , Department of Physiology and Pharmacology , University of Western Ontario , 100 Perth Drive St. , London , ON , Canada N6A 5K8
| | - François Lagugné-Labarthet
- Department of Chemistry and Center for Advanced Materials and Biomaterials , University of Western Ontario , London , ON , Canada N6A 5B7 . ; ; Tel: +1 519 661 2111 ext. 81006
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Ye F, Jiang J, Chang H, Xie L, Deng J, Ma Z, Yuan W. Improved single-cell culture achieved using micromolding in capillaries technology coupled with poly (HEMA). BIOMICROFLUIDICS 2015; 9:044106. [PMID: 26339307 PMCID: PMC4514715 DOI: 10.1063/1.4926807] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 07/02/2015] [Indexed: 05/16/2023]
Abstract
Cell studies at the single-cell level are becoming more and more critical for understanding the complex biological processes. Here, we present an optimization study investigating the positioning of single cells using micromolding in capillaries technology coupled with the cytophobic biomaterial poly (2-hydroxyethyl methacrylate) (poly (HEMA)). As a cytophobic biomaterial, poly (HEMA) was used to inhibit cells, whereas the glass was used as the substrate to provide a cell adhesive background. The poly (HEMA) chemical barrier was obtained using micromolding in capillaries, and the microchannel networks used for capillarity were easily achieved by reversibly bonding the polydimethylsiloxane mold and the glass. Finally, discrete cell adhesion regions were presented on the glass surface. This method is facile and low cost, and the reagents are commercially available. We validated the cytophobic abilities of the poly (HEMA), optimized the channel parameters for higher quality and more stable poly (HEMA) patterns by investigating the effects of changing the aspect ratio and the width of the microchannel on the poly (HEMA) grid pattern, and improved the single-cell occupancy by optimizing the dimensions of the cell adhesion regions.
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Affiliation(s)
- Fang Ye
- Key Laboratory of Micro/Nano Systems for Aerospace, Ministry of Education and School of Mechanical Engineering, Northwestern Polytechnical University , Xi'an 710072, People's Republic of China
| | - Jin Jiang
- Key Laboratory of Micro/Nano Systems for Aerospace, Ministry of Education and School of Mechanical Engineering, Northwestern Polytechnical University , Xi'an 710072, People's Republic of China
| | - Honglong Chang
- Key Laboratory of Micro/Nano Systems for Aerospace, Ministry of Education and School of Mechanical Engineering, Northwestern Polytechnical University , Xi'an 710072, People's Republic of China
| | - Li Xie
- Key Laboratory of Space Bioscience and Biotechnology, Institute of Special Environmental Biophysics, School of Life Sciences, Northwestern Polytechnical University , Xi'an 710072, People's Republic of China
| | - Jinjun Deng
- Key Laboratory of Micro/Nano Systems for Aerospace, Ministry of Education and School of Mechanical Engineering, Northwestern Polytechnical University , Xi'an 710072, People's Republic of China
| | - Zhibo Ma
- Key Laboratory of Micro/Nano Systems for Aerospace, Ministry of Education and School of Mechanical Engineering, Northwestern Polytechnical University , Xi'an 710072, People's Republic of China
| | - Weizheng Yuan
- Key Laboratory of Micro/Nano Systems for Aerospace, Ministry of Education and School of Mechanical Engineering, Northwestern Polytechnical University , Xi'an 710072, People's Republic of China
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