1
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Guo Y, Zhang X. Unveiling intracellular phase separation: advances in optical imaging of biomolecular condensates. Trends Biochem Sci 2024:S0968-0004(24)00163-4. [PMID: 39034215 DOI: 10.1016/j.tibs.2024.06.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 06/20/2024] [Accepted: 06/25/2024] [Indexed: 07/23/2024]
Abstract
Intracellular biomolecular condensates, which form via phase separation, display a highly organized ultrastructure and complex properties. Recent advances in optical imaging techniques, including super-resolution microscopy and innovative microscopic methods that leverage the intrinsic properties of the molecules observed, have transcended the limitations of conventional microscopies. These advances facilitate the exploration of condensates at finer scales and in greater detail. The deployment of these emerging but sophisticated imaging tools allows for precise observations of the multiphasic organization and physicochemical properties of these condensates, shedding light on their functions in cellular processes. In this review, we highlight recent progress in methodological innovations and their profound implications for understanding the organization and dynamics of intracellular biomolecular condensates.
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Affiliation(s)
- Yinfeng Guo
- Department of Chemistry, School of Science and Research Center for Industries of the Future, Westlake University, Hangzhou 310030, PR China
| | - Xin Zhang
- Department of Chemistry, School of Science and Research Center for Industries of the Future, Westlake University, Hangzhou 310030, PR China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou 310024, PR China.
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2
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Tenchov R, Sasso JM, Zhou QA. Polyglutamine (PolyQ) Diseases: Navigating the Landscape of Neurodegeneration. ACS Chem Neurosci 2024. [PMID: 38996083 DOI: 10.1021/acschemneuro.4c00184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/14/2024] Open
Abstract
Polyglutamine (polyQ) diseases are a group of inherited neurodegenerative disorders caused by expanded cytosine-adenine-guanine (CAG) repeats encoding proteins with abnormally expanded polyglutamine tract. A total of nine polyQ disorders have been identified, including Huntington's disease, six spinocerebellar ataxias, dentatorubral pallidoluysian atrophy (DRPLA), and spinal and bulbar muscular atrophy (SBMA). The diseases of this class are each considered rare, yet polyQ diseases constitute the largest group of monogenic neurodegenerative disorders. While each subtype of polyQ diseases has its own causative gene, certain pathologic molecular attributes have been implicated in virtually all of the polyQ diseases, including protein aggregation, proteolytic cleavage, neuronal dysfunction, transcription dysregulation, autophagy impairment, and mitochondrial dysfunction. Although animal models of polyQ disease are available helping to understand their pathogenesis and access disease-modifying therapies, there is neither a cure nor prevention for these diseases, with only symptomatic treatments available. In this paper, we analyze data from the CAS Content Collection to summarize the research progress in the class of polyQ diseases. We examine the publication landscape in the area in effort to provide insights into current knowledge advances and developments. We review the most discussed concepts and assess the strategies to combat these diseases. Finally, we inspect clinical applications of products against polyQ diseases with their development pipelines. The objective of this review is to provide a broad overview of the evolving landscape of current knowledge regarding the class of polyQ diseases, to outline challenges, and evaluate growth opportunities to further efforts in combating the diseases.
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Affiliation(s)
- Rumiana Tenchov
- CAS, a division of the American Chemical Society, Columbus, Ohio 43210, United States
| | - Janet M Sasso
- CAS, a division of the American Chemical Society, Columbus, Ohio 43210, United States
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3
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Dhillon AK, Dudhe PE, Majumdar S, Barman S, Ghosh D, Dhanasekaran K, Siddhanta S. Imaging of intracellular protein aggregates through plasmon-assisted clusteroluminescence. NANOSCALE 2024; 16:11749-11761. [PMID: 38864278 DOI: 10.1039/d4nr01803f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2024]
Abstract
The formation of clusters in non-aromatic molecules can give rise to unconventional luminescence or clusteroluminescence. Typically containing heteroatoms without extended conjugation or aromatic rings, these molecules have drawn much attention owing to the prospects of label-free biological imaging. However, their applications have been limited due to the lack of knowledge of the underlying mechanism. Herein, we have elucidated the mechanism of clusteroluminescence from proteins, which were explicitly aggregated using plasmonic silver nanoparticles. The nanoparticles promoted protein aggregation and induced nitrile formation on the surface, which, along with other lone-pair-containing heteroatoms, contributed to enhanced emission in the visible range. Remarkably, this makes imaging of proteins possible with visible excitations, as co-factor-lacking proteins generally undergo electronic transitions only in the ultraviolet range. Furthermore, the inherent protein-aggregating behaviour of plasmonic nanoparticles was harnessed for imaging of intracellular Huntingtin protein aggregates overexpressed in HeLa cells through clusteroluminescence. Significant plasmon-enhanced and red-shifted fluorescence emission was observed, which helped in the imaging and localization of the intracellular aggregates. Density functional theory calculations and transient absorbance spectroscopy were used to probe the molecular interactions at the protein-nanoparticle interface and the charge transfer states, further elucidating the role of nanoparticles and the emission mechanism. This technique thus opens alternate avenues for label-free fluorescence bioimaging.
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Affiliation(s)
- Ashish Kumar Dhillon
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi-110016, India.
| | - Pranay Eknath Dudhe
- Centrosome and Cilia Laboratory, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, Haryana (NCR Delhi) 121001, India.
| | - Shubhangi Majumdar
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi-110016, India.
| | - Sanmitra Barman
- Center for Advanced Materials and Devices (CAMD), BML Munjal University, Haryana, India
| | - Dibyajyoti Ghosh
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi-110016, India.
- Department of Materials Science and Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
| | - Karthigeyan Dhanasekaran
- Centrosome and Cilia Laboratory, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, Haryana (NCR Delhi) 121001, India.
| | - Soumik Siddhanta
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi-110016, India.
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4
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Qian C, Liu H, Chittur PK, Chadha RS, Yao Y, Kornfield JA, Tirrell DA, Wei L. Quantitative Real-Time Analysis of Living Materials by Stimulated Raman Scattering Microscopy. Anal Chem 2024; 96:6540-6549. [PMID: 38619937 DOI: 10.1021/acs.analchem.3c03736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
Composite materials built in part from living organisms have the potential to exhibit useful autonomous, adaptive, and self-healing behavior. The physicochemical, biological, and mechanical properties of such materials can be engineered through the genetic manipulation of their living components. Successful development of living materials will require not only new methods for design and preparation but also new analytical tools that are capable of real-time noninvasive mapping of chemical compositions. Here, we establish a strategy based on stimulated Raman scattering microscopy to monitor phosphatase-catalyzed mineralization of engineered bacterial films in situ. Real-time label-free imaging elucidates the mineralization process, quantifies both the organic and inorganic components of the material as functions of time, and reveals spatial heterogeneity at multiple scales. In addition, we correlate the mechanical performance of films with the extent of mineralization. This work introduces a promising strategy for quantitatively analyzing living materials, which should contribute to the accelerated development of such materials in the future.
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Affiliation(s)
- Chenxi Qian
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Hanwei Liu
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Priya K Chittur
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Rahuljeet S Chadha
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Yuxing Yao
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Julia A Kornfield
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - David A Tirrell
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Lu Wei
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
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5
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Ghazvini S, Uthaman S, Synan L, Lin EC, Sarkar S, Santillan MK, Santillan DA, Bardhan R. Predicting the onset of preeclampsia by longitudinal monitoring of metabolic changes throughout pregnancy with Raman spectroscopy. Bioeng Transl Med 2024; 9:e10595. [PMID: 38193120 PMCID: PMC10771567 DOI: 10.1002/btm2.10595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Revised: 07/04/2023] [Accepted: 08/15/2023] [Indexed: 01/10/2024] Open
Abstract
Preeclampsia is a life-threatening pregnancy disorder. Current clinical assays cannot predict the onset of preeclampsia until the late 2nd trimester, which often leads to poor maternal and neonatal outcomes. Here we show that Raman spectroscopy combined with machine learning in pregnant patient plasma enables rapid, highly sensitive maternal metabolome screening that predicts preeclampsia as early as the 1st trimester with >82% accuracy. We identified 12, 15 and 17 statistically significant metabolites in the 1st, 2nd and 3rd trimesters, respectively. Metabolic pathway analysis shows multiple pathways corresponding to amino acids, fatty acids, retinol, and sugars are enriched in the preeclamptic cohort relative to a healthy pregnancy. Leveraging Pearson's correlation analysis, we show for the first time with Raman Spectroscopy that metabolites are associated with several clinical factors, including patients' body mass index, gestational age at delivery, history of preeclampsia, and severity of preeclampsia. We also show that protein quantification alone of proinflammatory cytokines and clinically relevant angiogenic markers are inadequate in identifying at-risk patients. Our findings demonstrate that Raman spectroscopy is a powerful tool that may complement current clinical assays in early diagnosis and in the prognosis of the severity of preeclampsia to ultimately enable comprehensive prenatal care for all patients.
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Affiliation(s)
- Saman Ghazvini
- Department of Chemical and Biological EngineeringIowa State UniversityAmesIowaUSA
- Nanovaccine InstituteIowa State UniversityAmesIowaUSA
| | - Saji Uthaman
- Department of Chemical and Biological EngineeringIowa State UniversityAmesIowaUSA
- Nanovaccine InstituteIowa State UniversityAmesIowaUSA
| | - Lilly Synan
- Department of Chemical and Biological EngineeringIowa State UniversityAmesIowaUSA
- Nanovaccine InstituteIowa State UniversityAmesIowaUSA
| | - Eugene C. Lin
- Department of Chemistry and BiochemistryNational Chung Cheng UniversityChiayiTaiwan
| | - Soumik Sarkar
- Department of Mechanical EngineeringIowa state UniversityAmesIowaUSA
| | - Mark K. Santillan
- Department of Obstetrics and Gynecology, Carver College of MedicineUniversity of Iowa, Hospitals & ClinicsIowa CityIowaUSA
| | - Donna A. Santillan
- Department of Obstetrics and Gynecology, Carver College of MedicineUniversity of Iowa, Hospitals & ClinicsIowa CityIowaUSA
| | - Rizia Bardhan
- Department of Chemical and Biological EngineeringIowa State UniversityAmesIowaUSA
- Nanovaccine InstituteIowa State UniversityAmesIowaUSA
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6
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Pandey NK, Varkey J, Ajayan A, George G, Chen J, Langen R. Fluorescent protein tagging promotes phase separation and alters the aggregation pathway of huntingtin exon-1. J Biol Chem 2024; 300:105585. [PMID: 38141760 PMCID: PMC10825056 DOI: 10.1016/j.jbc.2023.105585] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 12/11/2023] [Accepted: 12/13/2023] [Indexed: 12/25/2023] Open
Abstract
Fluorescent protein tags are convenient tools for tracking the aggregation states of amyloidogenic or phase separating proteins, but the effect of the tags is often not well understood. Here, we investigated the impact of a C-terminal red fluorescent protein (RFP) tag on the phase separation of huntingtin exon-1 (Httex1), an N-terminal portion of the huntingtin protein that aggregates in Huntington's disease. We found that the RFP-tagged Httex1 rapidly formed micron-sized, phase separated states in the presence of a crowding agent. The formed structures had a rounded appearance and were highly dynamic according to electron paramagnetic resonance and fluorescence recovery after photobleaching, suggesting that the phase separated state was largely liquid in nature. Remarkably, the untagged protein did not undergo any detectable liquid condensate formation under the same conditions. In addition to strongly promoting liquid-liquid phase separation, the RFP tag also facilitated fibril formation, as the tag-dependent liquid condensates rapidly underwent a liquid-to-solid transition. The rate of fibril formation under these conditions was significantly faster than that of the untagged protein. When expressed in cells, the RFP-tagged Httex1 formed larger aggregates with different antibody staining patterns compared to untagged Httex1. Collectively, these data reveal that the addition of a fluorescent protein tag significantly impacts liquid and solid phase separations of Httex1 in vitro and leads to altered aggregation in cells. Considering that the tagged Httex1 is commonly used to study the mechanisms of Httex1 misfolding and toxicity, our findings highlight the importance to validate the conclusions with untagged protein.
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Affiliation(s)
- Nitin K Pandey
- Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Jobin Varkey
- Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Anakha Ajayan
- Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Gincy George
- Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Jeannie Chen
- Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Ralf Langen
- Physiology and Neuroscience, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, USA; Biochemistry and Molecular Medicine, Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
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7
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Xu FX, Wu R, Hu K, Fu D. Measuring Drug Response with Single-Cell Growth Rate Quantification. Anal Chem 2023; 95:18114-18121. [PMID: 38016067 PMCID: PMC11016461 DOI: 10.1021/acs.analchem.3c03434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2023]
Abstract
Intratumoral heterogeneity is a substantial cause of drug resistance development during chemotherapy or other drug treatments for cancer. Therefore, monitoring and measuring cell exposure and response to drugs at the single-cell level are crucial. Previous research suggested that the single-cell growth rate can be used to investigate drug-cell interactions. However, currently established methods for quantifying single-cell growth are limited to isolated or monolayer cells. Here, we introduce a technique that accurately measures both 2D and 3D cell growth rates using label-free ratiometric stimulated Raman scattering (SRS) microscopy. We use deuterated amino acids, leucine, isoleucine, and valine, as tracers and measure the C-D SRS signal from deuterium-labeled proteins and the C-H SRS signal from unlabeled proteins simultaneously to determine the cell growth rate at the single-cell level. The technique offers single-cell level drug sensitivity measurement with a shorter turnaround time (within 12 h) than most traditional assays. The submicrometer resolution of the imaging technique allows us to examine the effects of chemotherapeutic drugs, including kinase inhibitors, mitotic inhibitors, and topoisomerase II inhibitors, on both the cell growth rate and morphology. The capability of quantifying 3D cell growth rates provides insight into a deeper understanding of the cell-drug interaction in the actual tumor environment.
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Affiliation(s)
- Fiona Xi Xu
- Department of Chemistry, University of Washington, Seattle, WA 98195, United States
| | - Ruibing Wu
- Department of Chemistry, University of Washington, Seattle, WA 98195, United States
| | - Kailun Hu
- Department of Chemistry, University of Washington, Seattle, WA 98195, United States
| | - Dan Fu
- Department of Chemistry, University of Washington, Seattle, WA 98195, United States
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8
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Ibrahim KA, Grußmayer KS, Riguet N, Feletti L, Lashuel HA, Radenovic A. Label-free identification of protein aggregates using deep learning. Nat Commun 2023; 14:7816. [PMID: 38016971 PMCID: PMC10684545 DOI: 10.1038/s41467-023-43440-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 11/09/2023] [Indexed: 11/30/2023] Open
Abstract
Protein misfolding and aggregation play central roles in the pathogenesis of various neurodegenerative diseases (NDDs), including Huntington's disease, which is caused by a genetic mutation in exon 1 of the Huntingtin protein (Httex1). The fluorescent labels commonly used to visualize and monitor the dynamics of protein expression have been shown to alter the biophysical properties of proteins and the final ultrastructure, composition, and toxic properties of the formed aggregates. To overcome this limitation, we present a method for label-free identification of NDD-associated aggregates (LINA). Our approach utilizes deep learning to detect unlabeled and unaltered Httex1 aggregates in living cells from transmitted-light images, without the need for fluorescent labeling. Our models are robust across imaging conditions and on aggregates formed by different constructs of Httex1. LINA enables the dynamic identification of label-free aggregates and measurement of their dry mass and area changes during their growth process, offering high speed, specificity, and simplicity to analyze protein aggregation dynamics and obtain high-fidelity information.
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Affiliation(s)
- Khalid A Ibrahim
- Laboratory of Nanoscale Biology, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Kristin S Grußmayer
- Department of Bionanoscience and Kavli Institute of Nanoscience Delft, Delft University of Technology, Delft, Netherlands.
| | - Nathan Riguet
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Lely Feletti
- Laboratory of Nanoscale Biology, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Hilal A Lashuel
- Laboratory of Molecular and Chemical Biology of Neurodegeneration, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
| | - Aleksandra Radenovic
- Laboratory of Nanoscale Biology, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland.
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9
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Zheng C, Jiang ZJ, Jin K, Wang Q, Bai JF, Xu G, Gao Z. Pd-Catalyzed Regioselective Deuteration of Indole's C4-Position with Transient Directing Groups. J Org Chem 2023. [PMID: 37993979 DOI: 10.1021/acs.joc.3c02030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2023]
Abstract
As a representative scaffold of alkaloids, indoles have been extensively subjected to deuteration, but the regioselective C4 labeling has not been achieved due to its low reactivity. In this work, a Pd-catalyzed deuterium labeling at the indole's C4 position has been developed under the strategy of transient directing, using D2O as a deuterium source. The substituent effect is found to be crucial in facilitating this H/D exchange process, where the reversing C-D bond formation favors an electron-enriched ligation contrary to its C-H halogenation counterpart.
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Affiliation(s)
- Chenxu Zheng
- NingboTech-Cuiying Joint Laboratory of Stable Isotope Technology, School of Biological and Chemical Engineering, NingboTech University, Ningbo 315100, P. R. of China
- School of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310058, P. R. of China
| | - Zhi-Jiang Jiang
- NingboTech-Cuiying Joint Laboratory of Stable Isotope Technology, School of Biological and Chemical Engineering, NingboTech University, Ningbo 315100, P. R. of China
| | - Ke Jin
- NingboTech-Cuiying Joint Laboratory of Stable Isotope Technology, School of Biological and Chemical Engineering, NingboTech University, Ningbo 315100, P. R. of China
| | - Qian Wang
- NingboTech-Cuiying Joint Laboratory of Stable Isotope Technology, School of Biological and Chemical Engineering, NingboTech University, Ningbo 315100, P. R. of China
| | - Jian-Fei Bai
- NingboTech-Cuiying Joint Laboratory of Stable Isotope Technology, School of Biological and Chemical Engineering, NingboTech University, Ningbo 315100, P. R. of China
| | - Gang Xu
- School of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310058, P. R. of China
| | - Zhanghua Gao
- NingboTech-Cuiying Joint Laboratory of Stable Isotope Technology, School of Biological and Chemical Engineering, NingboTech University, Ningbo 315100, P. R. of China
- Ningbo Cuiying Chemical Technology Co. Ltd., Ningbo 315100, P. R. of China
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10
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Bai Y, Zhang S, Dong H, Liu Y, Liu C, Zhang X. Advanced Techniques for Detecting Protein Misfolding and Aggregation in Cellular Environments. Chem Rev 2023; 123:12254-12311. [PMID: 37874548 DOI: 10.1021/acs.chemrev.3c00494] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Protein misfolding and aggregation, a key contributor to the progression of numerous neurodegenerative diseases, results in functional deficiencies and the creation of harmful intermediates. Detailed visualization of this misfolding process is of paramount importance for improving our understanding of disease mechanisms and for the development of potential therapeutic strategies. While in vitro studies using purified proteins have been instrumental in delivering significant insights into protein misfolding, the behavior of these proteins in the complex milieu of living cells often diverges significantly from such simplified environments. Biomedical imaging performed in cell provides cellular-level information with high physiological and pathological relevance, often surpassing the depth of information attainable through in vitro methods. This review highlights a variety of methodologies used to scrutinize protein misfolding within biological systems. This includes optical-based methods, strategies leaning on mass spectrometry, in-cell nuclear magnetic resonance, and cryo-electron microscopy. Recent advancements in these techniques have notably deepened our understanding of protein misfolding processes and the features of the resulting misfolded species within living cells. The progression in these fields promises to catalyze further breakthroughs in our comprehension of neurodegenerative disease mechanisms and potential therapeutic interventions.
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Affiliation(s)
- Yulong Bai
- Department of Chemistry, Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou 310030, Zhejiang Province, China
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Shengnan Zhang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Hui Dong
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of the Chinese Academy of Sciences, 19 A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Yu Liu
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Cong Liu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Shanghai 200032, China
| | - Xin Zhang
- Department of Chemistry, Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou 310030, Zhejiang Province, China
- Westlake Laboratory of Life Sciences and Biomedicine, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
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11
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Messina MS, Chang CJ. Chemical Sensors and Imaging: Molecular, Materials, and Biological Platforms. ACS CENTRAL SCIENCE 2023; 9:1706-1711. [PMID: 37780366 PMCID: PMC10540294 DOI: 10.1021/acscentsci.3c01070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
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12
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Mirveis Z, Howe O, Cahill P, Patil N, Byrne HJ. Monitoring and modelling the glutamine metabolic pathway: a review and future perspectives. Metabolomics 2023; 19:67. [PMID: 37482587 PMCID: PMC10363518 DOI: 10.1007/s11306-023-02031-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 07/03/2023] [Indexed: 07/25/2023]
Abstract
BACKGROUND Analysis of the glutamine metabolic pathway has taken a special place in metabolomics research in recent years, given its important role in cell biosynthesis and bioenergetics across several disorders, especially in cancer cell survival. The science of metabolomics addresses the intricate intracellular metabolic network by exploring and understanding how cells function and respond to external or internal perturbations to identify potential therapeutic targets. However, despite recent advances in metabolomics, monitoring the kinetics of a metabolic pathway in a living cell in situ, real-time and holistically remains a significant challenge. AIM This review paper explores the range of analytical approaches for monitoring metabolic pathways, as well as physicochemical modeling techniques, with a focus on glutamine metabolism. We discuss the advantages and disadvantages of each method and explore the potential of label-free Raman microspectroscopy, in conjunction with kinetic modeling, to enable real-time and in situ monitoring of the cellular kinetics of the glutamine metabolic pathway. KEY SCIENTIFIC CONCEPTS Given its important role in cell metabolism, the ability to monitor and model the glutamine metabolic pathways are highlighted. Novel, label free approaches have the potential to revolutionise metabolic biosensing, laying the foundation for a new paradigm in metabolomics research and addressing the challenges in monitoring metabolic pathways in living cells.
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Affiliation(s)
- Zohreh Mirveis
- FOCAS Research Institute, Technological University Dublin, City Campus, Camden Row, Dublin 8, Ireland.
- School of Physics and Optometric & Clinical Sciences, Technological University Dublin, City Campus, Grangegorman, Dublin 7, Ireland.
| | - Orla Howe
- School of Biological, Health and Sport Sciences, Technological University Dublin, City Campus, Grangegorman, Dublin 7, Ireland
| | - Paul Cahill
- School of Biotechnology, Dublin City University, Glasnevin, Dublin 9, Ireland
| | - Nitin Patil
- FOCAS Research Institute, Technological University Dublin, City Campus, Camden Row, Dublin 8, Ireland
- School of Physics and Optometric & Clinical Sciences, Technological University Dublin, City Campus, Grangegorman, Dublin 7, Ireland
| | - Hugh J Byrne
- FOCAS Research Institute, Technological University Dublin, City Campus, Camden Row, Dublin 8, Ireland
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13
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Zhao J, Jiang L, Matlock A, Xu Y, Zhu J, Zhu H, Tian L, Wolozin B, Cheng JX. Mid-infrared chemical imaging of intracellular tau fibrils using fluorescence-guided computational photothermal microscopy. LIGHT, SCIENCE & APPLICATIONS 2023; 12:147. [PMID: 37322011 PMCID: PMC10272128 DOI: 10.1038/s41377-023-01191-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 05/18/2023] [Accepted: 05/21/2023] [Indexed: 06/17/2023]
Abstract
Amyloid proteins are associated with a broad spectrum of neurodegenerative diseases. However, it remains a grand challenge to extract molecular structure information from intracellular amyloid proteins in their native cellular environment. To address this challenge, we developed a computational chemical microscope integrating 3D mid-infrared photothermal imaging with fluorescence imaging, termed Fluorescence-guided Bond-Selective Intensity Diffraction Tomography (FBS-IDT). Based on a low-cost and simple optical design, FBS-IDT enables chemical-specific volumetric imaging and 3D site-specific mid-IR fingerprint spectroscopic analysis of tau fibrils, an important type of amyloid protein aggregates, in their intracellular environment. Label-free volumetric chemical imaging of human cells with/without seeded tau fibrils is demonstrated to show the potential correlation between lipid accumulation and tau aggregate formation. Depth-resolved mid-infrared fingerprint spectroscopy is performed to reveal the protein secondary structure of the intracellular tau fibrils. 3D visualization of the β-sheet for tau fibril structure is achieved.
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Affiliation(s)
- Jian Zhao
- Department of Electrical and Computer Engineering, Boston University, Boston, MA, 02215, USA.
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, 02142, USA.
| | - Lulu Jiang
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, 02118, USA
| | - Alex Matlock
- Department of Electrical and Computer Engineering, Boston University, Boston, MA, 02215, USA
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02142, USA
| | - Yihong Xu
- Department of Physics, Boston University, Boston, MA, 02215, USA
| | - Jiabei Zhu
- Department of Electrical and Computer Engineering, Boston University, Boston, MA, 02215, USA
| | - Hongbo Zhu
- State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, 130033, Changchun, China
| | - Lei Tian
- Department of Electrical and Computer Engineering, Boston University, Boston, MA, 02215, USA
- Department of Biomedical Engineering, Boston University, Boston, MA, 02215, USA
| | - Benjamin Wolozin
- Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, MA, 02118, USA
| | - Ji-Xin Cheng
- Department of Electrical and Computer Engineering, Boston University, Boston, MA, 02215, USA.
- Department of Physics, Boston University, Boston, MA, 02215, USA.
- Department of Biomedical Engineering, Boston University, Boston, MA, 02215, USA.
- Photonics Center, Boston University, Boston, MA, 02215, USA.
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14
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Wang H, Lee D, Wei L. Toward the Next Frontiers of Vibrational Bioimaging. CHEMICAL & BIOMEDICAL IMAGING 2023; 1:3-17. [PMID: 37122829 PMCID: PMC10131268 DOI: 10.1021/cbmi.3c00004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 03/03/2023] [Accepted: 03/10/2023] [Indexed: 05/02/2023]
Abstract
Chemical imaging based on vibrational contrasts can extract molecular information entangled in complex biological systems. To this end, nonlinear Raman scattering microscopy, mid-infrared photothermal (MIP) microscopy, and atomic force microscopy (AFM)-based force-detected photothermal microscopies are emerging with better chemical sensitivity, molecular specificity, and spatial resolution than conventional vibrational methods. Their utilization in bioimaging applications has provided biological knowledge in unprecedented detail. This Perspective outlines key methodological developments, bioimaging applications, and recent technical innovations of the three techniques. Representative biological demonstrations are also highlighted to exemplify the unique advantages of obtaining vibrational contrasts. With years of effort, these three methods compose an expanding vibrational bioimaging toolbox to tackle specific bioimaging needs, benefiting many biological investigations with rich information in both label-free and labeling manners. Each technique will be discussed and compared in the outlook, leading to possible future directions to accommodate growing needs in vibrational bioimaging.
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Affiliation(s)
- Haomin Wang
- Division
of Chemistry and Chemical Engineering, California
Institute of Technology, Pasadena, California 91125, United States
| | - Dongkwan Lee
- Division
of Chemistry and Chemical Engineering, California
Institute of Technology, Pasadena, California 91125, United States
| | - Lu Wei
- Division
of Chemistry and Chemical Engineering, California
Institute of Technology, Pasadena, California 91125, United States
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15
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Jia H, Yue S. Stimulated Raman Scattering Imaging Sheds New Light on Lipid Droplet Biology. J Phys Chem B 2023; 127:2381-2394. [PMID: 36897936 PMCID: PMC10042165 DOI: 10.1021/acs.jpcb.3c00038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 02/05/2023] [Indexed: 03/11/2023]
Abstract
A lipid droplet (LD) is a dynamic organelle closely associated with cellular functions and energy homeostasis. Dysregulated LD biology underlies an increasing number of human diseases, including metabolic disease, cancer, and neurodegenerative disorder. Commonly used lipid staining and analytical tools have difficulty providing the information regarding LD distribution and composition at the same time. To address this problem, stimulated Raman scattering (SRS) microscopy uses the intrinsic chemical contrast of biomolecules to achieve both direct visualization of LD dynamics and quantitative analysis of LD composition with high molecular selectivity at the subcellular level. Recent developments of Raman tags have further enhanced sensitivity and specificity of SRS imaging without perturbing molecular activity. With these advantages, SRS microscopy has offered great promise for deciphering LD metabolism in single live cells. This article overviews and discusses the latest applications of SRS microscopy as an emerging platform to dissect LD biology in health and disease.
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Affiliation(s)
- Hao Jia
- Key Laboratory of Biomechanics and
Mechanobiology (Beihang University), Ministry of Education, Institute
of Medical Photonics, Beijing Advanced Innovation Center for Biomedical
Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
| | - Shuhua Yue
- Key Laboratory of Biomechanics and
Mechanobiology (Beihang University), Ministry of Education, Institute
of Medical Photonics, Beijing Advanced Innovation Center for Biomedical
Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191, China
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16
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Ranasinghe JC, Wang Z, Huang S. Raman Spectroscopy on Brain Disorders: Transition from Fundamental Research to Clinical Applications. BIOSENSORS 2022; 13:27. [PMID: 36671862 PMCID: PMC9855372 DOI: 10.3390/bios13010027] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/13/2022] [Accepted: 12/23/2022] [Indexed: 06/17/2023]
Abstract
Brain disorders such as brain tumors and neurodegenerative diseases (NDs) are accompanied by chemical alterations in the tissues. Early diagnosis of these diseases will provide key benefits for patients and opportunities for preventive treatments. To detect these sophisticated diseases, various imaging modalities have been developed such as computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET). However, they provide inadequate molecule-specific information. In comparison, Raman spectroscopy (RS) is an analytical tool that provides rich information about molecular fingerprints. It is also inexpensive and rapid compared to CT, MRI, and PET. While intrinsic RS suffers from low yield, in recent years, through the adoption of Raman enhancement technologies and advanced data analysis approaches, RS has undergone significant advancements in its ability to probe biological tissues, including the brain. This review discusses recent clinical and biomedical applications of RS and related techniques applicable to brain tumors and NDs.
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17
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Fluorogenic toolbox for visualizing protein aggregation: From designing principles to biological application. Trends Analyt Chem 2022. [DOI: 10.1016/j.trac.2022.116764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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18
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Wang L, Hsiung CH, Liu X, Wang S, Loredo A, Zhang X, Xiao H. Xanthone-based solvatochromic fluorophores for quantifying micropolarity of protein aggregates. Chem Sci 2022; 13:12540-12549. [PMID: 36382293 PMCID: PMC9629104 DOI: 10.1039/d2sc05004h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 10/12/2022] [Indexed: 01/31/2023] Open
Abstract
Proper three-dimensional structures are essential for maintaining the functionality of proteins and for avoiding pathological consequences of improper folding. Misfolding and aggregation of proteins have been both associated with neurodegenerative disease. Therefore, a variety of fluorogenic tools that respond to both polarity and viscosity have been developed to detect protein aggregation. However, the rational design of highly sensitive fluorophores that respond solely to polarity has remained elusive. In this work, we demonstrate that electron-withdrawing heteroatoms with (d-p)-π* conjugation can stabilize lowest unoccupied molecular orbital (LUMO) energy levels and promote bathochromic shifts. Guided by computational analyses, we have devised a novel series of xanthone-based solvatochromic fluorophores that have rarely been systematically studied. The resulting probes exhibit superior sensitivity to polarity but are insensitive to viscosity. As proof of concept, we have synthesized protein targeting probes for live-cell confocal imaging intended to quantify the polarity of misfolded and aggregated proteins. Interestingly, our results reveal several layers of protein aggregates in a way that we had not anticipated. First, microenvironments with reduced polarity were validated in the misfolding and aggregation of folded globular proteins. Second, granular aggregates of AgHalo displayed a less polar environment than aggregates formed by folded globular protein represented by Htt-polyQ. Third, our studies reveal that granular protein aggregates formed in response to different types of stressors exhibit significant polarity differences. These results show that the solvatochromic fluorophores solely responsive to polarity represent a new class of indicators that can be widely used for detecting protein aggregation in live cells, thus paving the way for elucidating cellular mechanisms of protein aggregation as well as therapeutic approaches to managing intracellular aggregates.
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Affiliation(s)
- Lushun Wang
- Department of Chemistry, Rice University6100 Main StreetHoustonTexas77005USA
| | - Chia-Heng Hsiung
- Department of Chemistry, Pennsylvania State University, University ParkPA 16802USA,Department of Biochemistry and Molecular Biology, Pennsylvania State University, University ParkPA 16802USA
| | - Xiaojing Liu
- Department of Chemistry, Pennsylvania State University, University ParkPA 16802USA
| | - Shichao Wang
- Department of Chemistry, Rice University6100 Main StreetHoustonTexas77005USA
| | - Axel Loredo
- Department of Chemistry, Rice University6100 Main StreetHoustonTexas77005USA
| | - Xin Zhang
- Department of Chemistry, Pennsylvania State University, University ParkPA 16802USA,Department of Biochemistry and Molecular Biology, Pennsylvania State University, University ParkPA 16802USA
| | - Han Xiao
- Department of Chemistry, Rice University6100 Main StreetHoustonTexas77005USA,Department of Biosciences, Rice University6100 Main StreetHoustonTexas77005USA,Department of Bioengineering, Rice University6100 Main StreetHoustonTexas77005USA
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19
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Mitrea DM, Mittasch M, Gomes BF, Klein IA, Murcko MA. Modulating biomolecular condensates: a novel approach to drug discovery. Nat Rev Drug Discov 2022; 21:841-862. [PMID: 35974095 PMCID: PMC9380678 DOI: 10.1038/s41573-022-00505-4] [Citation(s) in RCA: 83] [Impact Index Per Article: 41.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2022] [Indexed: 12/12/2022]
Abstract
In the past decade, membraneless assemblies known as biomolecular condensates have been reported to play key roles in many cellular functions by compartmentalizing specific proteins and nucleic acids in subcellular environments with distinct properties. Furthermore, growing evidence supports the view that biomolecular condensates often form by phase separation, in which a single-phase system demixes into a two-phase system consisting of a condensed phase and a dilute phase of particular biomolecules. Emerging understanding of condensate function in normal and aberrant cellular states, and of the mechanisms of condensate formation, is providing new insights into human disease and revealing novel therapeutic opportunities. In this Perspective, we propose that such insights could enable a previously unexplored drug discovery approach based on identifying condensate-modifying therapeutics (c-mods), and we discuss the strategies, techniques and challenges involved.
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20
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Eriksson R, Gren P, Sjödahl M, Ramser K. Investigation of the Spatial Generation of Stimulated Raman Scattering Using Computer Simulation and Experimentation. APPLIED SPECTROSCOPY 2022; 76:1307-1316. [PMID: 36281542 DOI: 10.1177/00037028221123593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Stimulated Raman scattering is a phenomenon with potential use in providing real-time molecular information in three-dimensions (3D) of a sample using imaging. For precise imaging, the knowledge about the spatial generation of stimulated Raman scattering is essential. To investigate the spatial behavior in an idealized case, computer simulations and experiments were performed. For the computer simulations, diffraction theory was used for the beam propagation complemented with nonlinear phase modulation describing the interaction between the light and matter. For the experiments, a volume of ethanol was illuminated by an expanded light beam and a plane inside the volume was imaged in transmission. For generating stimulated Raman scattering, a pump beam was focused into this volume and led to a beam dump after passing the volume. The pulse duration of the two beams were 6 ns and the pump beam energy ranged from 1 to 27 mJ. The effect of increasing pump power on the spatial distribution of the Raman gain and the spatial growth of the signal at different interaction lengths between the beam and the sample was investigated. The spatial width of the region where the stimulated Raman scattering signal was generated for experiments and simulation was 0.21 and 0.09 mm, respectively. The experimental and simulation results showed that most of the stimulated Raman scattering is generated close to the pump beam focus and the maximum peak of the Stokes intensity spatially comes shortly after the peak of the pump intensity.
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Affiliation(s)
- Ronja Eriksson
- Department of Engineering Science and Mathematics, 407846Luleå University of Technology, Luleå, Sweden
| | - Per Gren
- Department of Engineering Science and Mathematics, 407846Luleå University of Technology, Luleå, Sweden
| | - Mikael Sjödahl
- Department of Engineering Science and Mathematics, 407846Luleå University of Technology, Luleå, Sweden
| | - Kerstin Ramser
- Department of Engineering Science and Mathematics, 407846Luleå University of Technology, Luleå, Sweden
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21
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Yuan Y, Lu F. A Flexible Chamber for Time-Lapse Live-Cell Imaging with Stimulated Raman Scattering Microscopy. J Vis Exp 2022:10.3791/64449. [PMID: 36121285 PMCID: PMC9631341 DOI: 10.3791/64449] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2024] Open
Abstract
Stimulated Raman scattering (SRS) microscopy is a label-free chemical imaging technology. Live-cell imaging with SRS has been demonstrated for many biological and biomedical applications. However, long-term time-lapse SRS imaging of live cells has not been widely adopted. SRS microscopy often uses a high numerical aperture (NA) water-immersion objective and a high NA oil-immersion condenser to achieve high-resolution imaging. In this case, the gap between the objective and the condenser is only a few millimeters. Therefore, most commercial stage-top environmental chambers cannot be used for SRS imaging because of their large thickness with a rigid glass cover. This paper describes the design and fabrication of a flexible chamber that can be used for time-lapse live-cell imaging with transmitted SRS signal detection on an upright microscope frame. The flexibility of the chamber is achieved by using a soft material - a thin natural rubber film. The new enclosure and chamber design can be easily added to an existing SRS imaging setup. The testing and preliminary results demonstrate that the flexible chamber system enables stable, long-term, time-lapse SRS imaging of live cells, which can be used for various bioimaging applications in the future.
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Affiliation(s)
- Yuhao Yuan
- Department of Biomedical Engineering, Binghamton University, State University of New York
| | - Fake Lu
- Department of Biomedical Engineering, Binghamton University, State University of New York;
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22
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Benson S, de Moliner F, Tipping W, Vendrell M. Miniaturized Chemical Tags for Optical Imaging. Angew Chem Int Ed Engl 2022; 61:e202204788. [PMID: 35704518 PMCID: PMC9542129 DOI: 10.1002/anie.202204788] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Indexed: 11/06/2022]
Abstract
Recent advances in optical bioimaging have prompted the need for minimal chemical reporters that can retain the molecular recognition properties and activity profiles of biomolecules. As a result, several methodologies to reduce the size of fluorescent and Raman labels to a few atoms (e.g., single aryl fluorophores, Raman‐active triple bonds and isotopes) and embed them into building blocks (e.g., amino acids, nucleobases, sugars) to construct native‐like supramolecular structures have been described. The integration of small optical reporters into biomolecules has also led to smart molecular entities that were previously inaccessible in an expedite manner. In this article, we review recent chemical approaches to synthesize miniaturized optical tags as well as some of their multiple applications in biological imaging.
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Affiliation(s)
- Sam Benson
- Centre for Inflammation Research The University of Edinburgh Edinburgh EH16 4TJ UK
| | - Fabio de Moliner
- Centre for Inflammation Research The University of Edinburgh Edinburgh EH16 4TJ UK
| | - William Tipping
- Centre for Molecular Nanometrology The University of Strathclyde Glasgow G1 1RD UK
| | - Marc Vendrell
- Centre for Inflammation Research The University of Edinburgh Edinburgh EH16 4TJ UK
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23
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Abstract
As an emerging optical imaging modality, stimulated Raman scattering (SRS) microscopy provides invaluable opportunities for chemical biology studies using its rich chemical information. Through rapid progress over the past decade, the development of Raman probes harnessing the chemical biology toolbox has proven to play a key role in advancing SRS microscopy and expanding biological applications. In this perspective, we first discuss the development of biorthogonal SRS imaging using small tagging of triple bonds or isotopes and highlight their unique advantages for metabolic pathway analysis and microbiology investigations. Potential opportunities for chemical biology studies integrating small tagging with SRS imaging are also proposed. We next summarize the current designs of highly sensitive and super-multiplexed SRS probes, as well as provide future directions and considerations for next-generation functional probe design. These rationally designed SRS probes are envisioned to bridge the gap between SRS microscopy and chemical biology research and should benefit their mutual development.
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Affiliation(s)
- Jiajun Du
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
| | - Haomin Wang
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
| | - Lu Wei
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA
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24
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Benson S, de Moliner F, Tipping W, Vendrell M. Miniaturized Chemical Tags for Optical Imaging. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202204788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Sam Benson
- The University of Edinburgh Centre for Inflammation Research UNITED KINGDOM
| | - Fabio de Moliner
- The University of Edinburgh Centre for Inflammation Research UNITED KINGDOM
| | - William Tipping
- University of Strathclyde Centre for Molecular Nanometrology UNITED KINGDOM
| | - Marc Vendrell
- University of Edinburgh Centre for Inflammation Research 47 Little France Crescent EH16 4TJ Edinburgh UNITED KINGDOM
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25
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Manifold B, Fu D. Quantitative Stimulated Raman Scattering Microscopy: Promises and Pitfalls. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2022; 15:269-289. [PMID: 35300525 PMCID: PMC10083020 DOI: 10.1146/annurev-anchem-061020-015110] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Since its first demonstration, stimulated Raman scattering (SRS) microscopy has become a powerful chemical imaging tool that shows promise in numerous biological and biomedical applications. The spectroscopic capability of SRS enables identification and tracking of specific molecules or classes of molecules, often without labeling. SRS microscopy also has the hallmark advantage of signal strength that is directly proportional to molecular concentration, allowing for in situ quantitative analysis of chemical composition of heterogeneous samples with submicron spatial resolution and subminute temporal resolution. However, it is important to recognize that quantification through SRS microscopy requires assumptions regarding both system and sample. Such assumptions are often taken axiomatically, which may lead to erroneous conclusions without proper validation. In this review, we focus on the tacitly accepted, yet complex, quantitative aspect of SRS microscopy. We discuss the various approaches to quantitative analysis, examples of such approaches, challenges in different systems, and potential solutions. Through our examination of published literature, we conclude that a scrupulous approach to experimental design can further expand the powerful and incisive quantitative capabilities of SRS microscopy.
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Affiliation(s)
- Bryce Manifold
- Department of Chemistry, University of Washington, Seattle, Washington, USA;
| | - Dan Fu
- Department of Chemistry, University of Washington, Seattle, Washington, USA;
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26
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Miao K, Lin LE, Qian C, Wei L. Label-free Super-resolution Imaging Enabled by Vibrational Imaging of Swelled Tissue and Analysis. J Vis Exp 2022:10.3791/63824. [PMID: 35661092 PMCID: PMC9549918 DOI: 10.3791/63824] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2024] Open
Abstract
The universal utilization of fluorescence microscopy, especially super-resolution microscopy, has greatly advanced knowledge about modern biology. Conversely, the requirement of fluorophore labeling in fluorescent techniques poses significant challenges, such as photobleaching and non-uniform labeling of fluorescent probes and prolonged sample processing. In this protocol, the detailed working procedures of vibrational imaging of swelled tissue and analysis (VISTA) are presented. VISTA circumvents obstacles associated with fluorophores and achieves label-free super-resolution volumetric imaging in biological samples with spatial resolution down to 78 nm. The procedure is established by embedding cells and tissues in hydrogel, isotropically expanding the hydrogel sample hybrid, and visualizing endogenous protein distributions by vibrational imaging with stimulated Raman scattering microscopy. The method is demonstrated on both cells and mouse brain tissues. Highly correlative VISTA and immunofluorescence images were observed, validating the protein origin of imaging specificities. Exploiting such correlation, a machine learning-based image-segmentation algorithm was trained to achieve multi-component prediction of nuclei, blood vessels, neuronal cells, and dendrites from label-free mouse brain images. The procedure was further adapted to investigate pathological poly-glutamine (polyQ) aggregates in cells and amyloid-beta (Aβ) plaques in brain tissues with high throughput, justifying its potential for large-scale clinical samples.
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Affiliation(s)
- Kun Miao
- Division of Chemistry and Chemical Engineering, California Institute of Technology
| | - Li-En Lin
- Division of Chemistry and Chemical Engineering, California Institute of Technology
| | - Chenxi Qian
- Division of Chemistry and Chemical Engineering, California Institute of Technology
| | - Lu Wei
- Division of Chemistry and Chemical Engineering, California Institute of Technology;
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27
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Adams ZC, Olson EJ, Lopez-Silva TL, Lian Z, Kim AY, Holcomb M, Zimmermann J, Adhikary R, Dawson PE. Direct observation of peptide hydrogel self-assembly. Chem Sci 2022; 13:10020-10028. [PMID: 36128231 PMCID: PMC9430618 DOI: 10.1039/d1sc06562a] [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: 11/24/2021] [Accepted: 07/14/2022] [Indexed: 11/30/2022] Open
Abstract
The characterization of self-assembling molecules presents significant experimental challenges, especially when associated with phase separation or precipitation. Transparent window infrared (IR) spectroscopy leverages site-specific probes that absorb in the “transparent window” region of the biomolecular IR spectrum. Carbon–deuterium (C–D) bonds are especially compelling transparent window probes since they are non-perturbative, can be readily introduced site selectively into peptides and proteins, and their stretch frequencies are sensitive to changes in the local molecular environment. Importantly, IR spectroscopy can be applied to a wide range of molecular samples regardless of solubility or physical state, making it an ideal technique for addressing the solubility challenges presented by self-assembling molecules. Here, we present the first continuous observation of transparent window probes following stopped-flow initiation. To demonstrate utility in a self-assembling system, we selected the MAX1 peptide hydrogel, a biocompatible material that has significant promise for use in drug delivery and medical applications. C–D labeled valine was synthetically introduced into five distinct positions of the twenty-residue MAX1 β-hairpin peptide. Consistent with current structural models, steady-state IR absorption frequencies and linewidths of C–D bonds at all labeled positions indicate that these side chains occupy a hydrophobic region of the hydrogel and that the motion of side chains located in the middle of the hairpin is more restricted than those located on the hairpin ends. Following a rapid change in ionic strength to initiate self-assembly, the peptide absorption spectra were monitored as function of time, allowing determination of site-specific time constants. We find that within the experimental resolution, MAX1 self-assembly occurs as a cooperative process. These studies suggest that stopped-flow transparent window FTIR can be extended to other time-resolved applications, such as protein folding and enzyme kinetics. To facilitate the characterization of phase-transitioning molecules, site-specific non-perturbative infrared probes are leveraged for continuous observation of the self-assembly of fibrils in a peptide hydrogel following stopped-flow initiation.![]()
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Affiliation(s)
- Zoë C. Adams
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California, 92037, USA
| | - Erika J. Olson
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California, 92037, USA
| | - Tania L. Lopez-Silva
- Chemical Biology Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
| | - Zhengwen Lian
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California, 92037, USA
| | - Audrey Y. Kim
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California, 92037, USA
| | - Matthew Holcomb
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California, 92037, USA
| | - Jörg Zimmermann
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California, 92037, USA
| | - Ramkrishna Adhikary
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California, 92037, USA
| | - Philip E. Dawson
- Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California, 92037, USA
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28
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Shuster SO, Lee JC. Watching liquid droplets of TDP-43 CTD age by Raman spectroscopy. J Biol Chem 2021; 298:101528. [PMID: 34953857 PMCID: PMC8784639 DOI: 10.1016/j.jbc.2021.101528] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/16/2021] [Accepted: 12/20/2021] [Indexed: 12/14/2022] Open
Abstract
Liquid-liquid phase-separation (LLPS) is a biological phenomenon wherein a metastable, concentrated droplet phase of biomolecules spontaneously forms. A link may exist between LLPS of proteins and the disease-related process of amyloid fibril formation; however, this connection is not fully understood. Here, we investigated the relationship between LLPS and aggregation of the C-terminal domain of TAR DNA-binding protein 43, an amyotrophic lateral sclerosis-related protein known to both phase-separate and form amyloids, by monitoring conformational changes during droplet aging using Raman spectroscopy. We found that the earliest aggregation events occurred within droplets as indicated by the development of β-sheet structure and increased thioflavin-T emission. Interestingly, filamentous aggregates appeared outside the solidified droplets at a later time, suggestive that amyloid formation is a heterogeneous process under LLPS solution conditions. Furthermore, the secondary structure content of aggregated structures inside droplets are distinct from that in de novo fibrils, implying that fibril polymorphism develops as a result of different environments (LLPS vs. bulk solution), which may have pathological significance.
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Affiliation(s)
- Sydney O Shuster
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Jennifer C Lee
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA.
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29
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Nuclear and cytoplasmic huntingtin inclusions exhibit distinct biochemical composition, interactome and ultrastructural properties. Nat Commun 2021; 12:6579. [PMID: 34772920 PMCID: PMC8589980 DOI: 10.1038/s41467-021-26684-z] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/11/2021] [Indexed: 12/20/2022] Open
Abstract
Despite the strong evidence linking the aggregation of the Huntingtin protein (Htt) to the pathogenesis of Huntington's disease (HD), the mechanisms underlying Htt aggregation and neurodegeneration remain poorly understood. Herein, we investigated the ultrastructural properties and protein composition of Htt cytoplasmic and nuclear inclusions in mammalian cells and primary neurons overexpressing mutant exon1 of the Htt protein. Our findings provide unique insight into the ultrastructural properties of cytoplasmic and nuclear Htt inclusions and their mechanisms of formation. We show that Htt inclusion formation and maturation are complex processes that, although initially driven by polyQ-dependent Htt aggregation, also involve the polyQ and PRD domain-dependent sequestration of lipids and cytoplasmic and cytoskeletal proteins related to HD dysregulated pathways; the recruitment and accumulation of remodeled or dysfunctional membranous organelles, and the impairment of the protein quality control and degradation machinery. We also show that nuclear and cytoplasmic Htt inclusions exhibit distinct biochemical compositions and ultrastructural properties, suggesting different mechanisms of aggregation and toxicity.
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30
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Boorman D, Pope I, Masia F, Watson P, Borri P, Langbein W. Quantification of the nonlinear susceptibility of the hydrogen and deuterium stretch vibration for biomolecules in coherent Raman micro-spectroscopy. JOURNAL OF RAMAN SPECTROSCOPY : JRS 2021; 52:1540-1551. [PMID: 36339900 PMCID: PMC9627839 DOI: 10.1002/jrs.6164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/12/2021] [Accepted: 05/16/2021] [Indexed: 06/14/2023]
Abstract
Deuterium labelling is increasingly used in coherent Raman imaging of complex systems, such as biological cells and tissues, to improve chemical specificity. Nevertheless, quantitative coherent Raman susceptibility spectra for deuterated compounds have not been previously reported. Interestingly, it is expected theoretically that -D stretch vibrations have a Raman susceptibility lower than -H stretch vibrations, with the area of their imaginary part scaling with their wavenumber, which is shifted from around 2900 cm-1 for C-H into the silent region around 2100 cm-1 for C-D. Here, we report quantitative measurements of the nonlinear susceptibility of water, succinic acid, oleic acid, linoleic acid and deuterated isoforms. We show that the -D stretch vibration has indeed a lower area, consistent with the frequency reduction due to the doubling of atomic mass from hydrogen to deuterium. This finding elucidates an important trade-off between chemical specificity and signal strength in the adoption of deuterium labelling as an imaging strategy for coherent Raman microscopy.
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Affiliation(s)
- Dale Boorman
- School of BiosciencesCardiff UniversityCardiffUK
| | - Iestyn Pope
- School of BiosciencesCardiff UniversityCardiffUK
| | | | - Peter Watson
- School of BiosciencesCardiff UniversityCardiffUK
| | - Paola Borri
- School of BiosciencesCardiff UniversityCardiffUK
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31
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Huang Y, Bai Y, Jin W, Shen D, Lyu H, Zeng L, Wang M, Liu Y. Common Pitfalls and Recommendations for Using a Turbidity Assay to Study Protein Phase Separation. Biochemistry 2021; 60:2447-2456. [PMID: 34369156 DOI: 10.1021/acs.biochem.1c00386] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The turbidity assay is commonly exploited to study protein liquid-to-liquid phase separation (LLPS) or liquid-to-solid phase separation (LSPS) processes in biochemical analyses. Herein, we present common pitfalls of this assay caused by exceeding the detection linear range. We showed that aggregated proteins of high concentration and large particle size can lead to inaccurate quantification in multiple applications, including the optical density measurement, the thermal shift assay, and the dynamic light scattering experiment. Finally, we demonstrated that a simple sample dilution of insoluble aggregated protein (LSPS) samples or direct imaging of liquid droplets (LLPS) can address these issues and improve the accuracy of the turbidity assay.
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Affiliation(s)
- Yanan Huang
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian, Liaoning 116023, China
| | - Yulong Bai
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian, Liaoning 116023, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wenhan Jin
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian, Liaoning 116023, China
| | - Di Shen
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian, Liaoning 116023, China
| | - Haochen Lyu
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian, Liaoning 116023, China
| | - Lianggang Zeng
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian, Liaoning 116023, China
| | - Mengdie Wang
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian, Liaoning 116023, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yu Liu
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian, Liaoning 116023, China
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32
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Watson MD, Lee JC. Coupling chemical biology and vibrational spectroscopy for studies of amyloids in vitro and in cells. Curr Opin Chem Biol 2021; 64:90-97. [PMID: 34186291 DOI: 10.1016/j.cbpa.2021.05.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 05/04/2021] [Accepted: 05/18/2021] [Indexed: 01/21/2023]
Abstract
Amyloid diseases are characterized by the aggregation of various proteins to form insoluble β-sheet-rich fibrils leading to cell death. Vibrational spectroscopies have emerged as attractive methods to study this process because of the rich structural information that can be extracted without large, perturbative probes. Importantly, specific vibrations such as the amide-I band directly report on secondary structure changes, which are key features of amyloid formation. Beyond intrinsic vibrations, the incorporation of unnatural vibrational probes can improve sensitivity for secondary structure determination (e.g. isotopic labeling), can provide residue-specific information of the surrounding polarity (e.g. unnatural amino acid), and are translatable into cellular studies. Here, we review the latest studies that have leveraged tools from chemical biology for the incorporation of novel vibrational probes into amyloidogenic proteins for both mechanistic and cellular studies.
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Affiliation(s)
- Matthew D Watson
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Jennifer C Lee
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA.
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33
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Murakami K, Kajimoto S, Shibata D, Kuroi K, Fujii F, Nakabayashi T. Observation of liquid-liquid phase separation of ataxin-3 and quantitative evaluation of its concentration in a single droplet using Raman microscopy. Chem Sci 2021; 12:7411-7418. [PMID: 34163831 PMCID: PMC8171347 DOI: 10.1039/d0sc06095j] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 04/09/2021] [Indexed: 12/31/2022] Open
Abstract
Liquid-liquid phase separation (LLPS) plays an important role in a variety of biological processes and is also associated with protein aggregation in neurodegenerative diseases. Quantification of LLPS is necessary to elucidate the mechanism of LLPS and the subsequent aggregation process. In this study, we showed that ataxin-3, which is associated with Machado-Joseph disease, exhibits LLPS in an intracellular crowding environment mimicked by biopolymers, and proposed that a single droplet formed in LLPS can be quantified using Raman microscopy in a label-free manner. We succeeded in evaluating the protein concentration and identifying the components present inside and outside a droplet using the O-H stretching band of water as an internal intensity standard. Only water and protein were detected to be present inside droplets with crowding agents remaining outside. The protein concentration in a droplet was dependent on the crowding environment, indicating that the protein concentration and intracellular environment should be considered when investigating LLPS. Raman microscopy has the potential to become a powerful technique for clarifying the chemical nature of LLPS and its relationship with protein aggregation.
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Affiliation(s)
- Kazuki Murakami
- Graduate School of Pharmaceutical Sciences, Tohoku University Aoba-ku Sendai 980-8578 Japan
| | - Shinji Kajimoto
- Graduate School of Pharmaceutical Sciences, Tohoku University Aoba-ku Sendai 980-8578 Japan
| | - Daiki Shibata
- Graduate School of Pharmaceutical Sciences, Tohoku University Aoba-ku Sendai 980-8578 Japan
| | - Kunisato Kuroi
- Faculty of Pharmaceutical Sciences, Kobe Gakuin University 1-1-3 Minatojima, Chuo-ku Kobe 650-8586 Japan
| | - Fumihiko Fujii
- Faculty of Pharmaceutical Sciences, Kobe Gakuin University 1-1-3 Minatojima, Chuo-ku Kobe 650-8586 Japan
| | - Takakazu Nakabayashi
- Graduate School of Pharmaceutical Sciences, Tohoku University Aoba-ku Sendai 980-8578 Japan
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34
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Adamczyk A, Matuszyk E, Radwan B, Rocchetti S, Chlopicki S, Baranska M. Toward Raman Subcellular Imaging of Endothelial Dysfunction. J Med Chem 2021; 64:4396-4409. [PMID: 33821652 PMCID: PMC8154563 DOI: 10.1021/acs.jmedchem.1c00051] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
![]()
Multiple diseases are at some point associated with altered endothelial
function, and endothelial dysfunction (ED) contributes to their pathophysiology.
Biochemical changes of the dysfunctional endothelium are linked to
various cellular organelles, including the mitochondria, endoplasmic
reticulum, and nucleus, so organelle-specific insight is needed for
better understanding of endothelial pathobiology. Raman imaging, which
combines chemical specificity with microscopic resolution, has proved
to be useful in detecting biochemical changes in ED at the cellular
level. However, the detection of spectroscopic markers associated
with specific cell organelles, while desirable, cannot easily be achieved
by Raman imaging without labeling. This critical review summarizes
the current advances in Raman-based analysis of ED, with a focus on
a new approach involving molecular Raman reporters that could facilitate
the study of biochemical changes in cellular organelles. Finally,
imaging techniques based on both conventional spontaneous Raman scattering
and the emerging technique of stimulated Raman scattering are discussed.
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Affiliation(s)
- Adriana Adamczyk
- Faculty of Chemistry, Jagiellonian University, 2 Gronostajowa Str., 30-387 Krakow, Poland.,Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, 14 Bobrzynskiego Str., 30-348 Krakow, Poland
| | - Ewelina Matuszyk
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, 14 Bobrzynskiego Str., 30-348 Krakow, Poland
| | - Basseem Radwan
- Faculty of Chemistry, Jagiellonian University, 2 Gronostajowa Str., 30-387 Krakow, Poland.,Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, 14 Bobrzynskiego Str., 30-348 Krakow, Poland
| | - Stefano Rocchetti
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, 14 Bobrzynskiego Str., 30-348 Krakow, Poland
| | - Stefan Chlopicki
- Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, 14 Bobrzynskiego Str., 30-348 Krakow, Poland.,Chair of Pharmacology, Jagiellonian University, 16 Grzegorzecka Str., 31-531 Krakow, Poland
| | - Malgorzata Baranska
- Faculty of Chemistry, Jagiellonian University, 2 Gronostajowa Str., 30-387 Krakow, Poland.,Jagiellonian Centre for Experimental Therapeutics (JCET), Jagiellonian University, 14 Bobrzynskiego Str., 30-348 Krakow, Poland
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35
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Xu J, Yu T, Zois CE, Cheng JX, Tang Y, Harris AL, Huang WE. Unveiling Cancer Metabolism through Spontaneous and Coherent Raman Spectroscopy and Stable Isotope Probing. Cancers (Basel) 2021; 13:1718. [PMID: 33916413 PMCID: PMC8038603 DOI: 10.3390/cancers13071718] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 03/24/2021] [Accepted: 03/28/2021] [Indexed: 11/25/2022] Open
Abstract
Metabolic reprogramming is a common hallmark in cancer. The high complexity and heterogeneity in cancer render it challenging for scientists to study cancer metabolism. Despite the recent advances in single-cell metabolomics based on mass spectrometry, the analysis of metabolites is still a destructive process, thus limiting in vivo investigations. Being label-free and nonperturbative, Raman spectroscopy offers intrinsic information for elucidating active biochemical processes at subcellular level. This review summarizes recent applications of Raman-based techniques, including spontaneous Raman spectroscopy and imaging, coherent Raman imaging, and Raman-stable isotope probing, in contribution to the molecular understanding of the complex biological processes in the disease. In addition, this review discusses possible future directions of Raman-based technologies in cancer research.
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Affiliation(s)
- Jiabao Xu
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, UK;
| | - Tong Yu
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, UK;
| | - Christos E. Zois
- Molecular Oncology Laboratories, Department of Oncology, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford University, Oxford OX3 9DS, UK;
- Department of Radiotherapy and Oncology, School of Health, Democritus University of Thrace, 68100 Alexandroupolis, Greece
| | - Ji-Xin Cheng
- Department of Biomedical Engineering, Boston University, Boston, MS 02215, USA;
| | - Yuguo Tang
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou 215163, China;
| | - Adrian L. Harris
- Molecular Oncology Laboratories, Department of Oncology, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford University, Oxford OX3 9DS, UK;
| | - Wei E. Huang
- Department of Engineering Science, University of Oxford, Oxford OX1 3PJ, UK;
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36
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Watson MD, Flynn JD, Lee JC. Raman spectral imaging of 13C 2H 15N-labeled α-synuclein amyloid fibrils in cells. Biophys Chem 2021; 269:106528. [PMID: 33418468 PMCID: PMC7856057 DOI: 10.1016/j.bpc.2020.106528] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 10/29/2020] [Accepted: 10/30/2020] [Indexed: 12/11/2022]
Abstract
Parkinson's disease is characterized by the intracellular accumulation of α-synuclein (α-syn) amyloid fibrils, which are insoluble, β-sheet-rich protein aggregates. Raman spectroscopy is a powerful technique that reports on intrinsic molecular vibrations such as the coupled vibrational modes of the polypeptide backbone, yielding secondary structural information. However, in order to apply this method in cells, spectroscopically unique frequencies are necessary to resolve proteins of interest from the cellular proteome. Here, we report the use of 13C2H15N-labeled α-syn to study the localization of preformed fibrils fed to cells. Isotopic labeling shifts the amide-I (13CO) band away from endogenous 12CO vibrations, permitting secondary structural analysis of internalized α-syn fibrils. Similarly, 13C2H stretches move to lower energies in the "cellular quiet" region, where there is negligible biological spectral interference. This combination of well-resolved, distinct vibrations allows Raman spectral imaging of α-syn fibrils across a cell, which provides conformational information with spatial context.
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Affiliation(s)
- Matthew D Watson
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, United States of America
| | - Jessica D Flynn
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, United States of America
| | - Jennifer C Lee
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, United States of America.
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37
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Lee D, Du J, Yu R, Su Y, Heath JR, Wei L. Visualizing Subcellular Enrichment of Glycogen in Live Cancer Cells by Stimulated Raman Scattering. Anal Chem 2020; 92:13182-13191. [PMID: 32907318 PMCID: PMC10676777 DOI: 10.1021/acs.analchem.0c02348] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Glycogen, a branched glucose polymer, helps regulate glucose homeostasis through immediate storage and release of glucose. Reprogramming of glycogen metabolism has recently been suggested to play an emerging role in cancer progression and tumorigenesis. However, regulation of metabolic rewiring for glycogen synthesis and breakdown in cancer cells remains less understood. Despite the availability of various glycogen detection methods, selective visualization of glycogen in living cells with high spatial resolution has proven to be highly challenging. Here, we present an optical imaging strategy to visualize glycogen in live cancer cells with minimal perturbation by combining stimulated Raman scattering microscopy with metabolic incorporation of deuterium-labeled glucose. We revealed the subcellular enrichment of glycogen in live cancer cells and achieved specific glycogen mapping through distinct spectral identification. Using this method, different glycogen metabolic phenotypes were characterized in a series of patient-derived BRAF mutant melanoma cell lines. Our results indicate that cell lines manifesting high glycogen storage level showed increased tolerance to glucose deficiency among the studied melanoma phenotypes. This method opens up the possibility for noninvasive study of complex glycogen metabolism at subcellular resolution and may help reveal new features of glycogen regulation in cancer systems.
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Affiliation(s)
- Dongkwan Lee
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E California Blvd, Pasadena, CA, 91125, USA
| | - Jiajun Du
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E California Blvd, Pasadena, CA, 91125, USA
| | - Rona Yu
- Division of Engineering and Applied Science, California Institute of Technology, 1200 E California Blvd, Pasadena, CA, 91125, USA
| | - Yapeng Su
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E California Blvd, Pasadena, CA, 91125, USA
- Institute of Systems Biology, 501 Terry Avenue North, Seattle, WA, 98109-5263, USA
| | - James R. Heath
- Institute of Systems Biology, 501 Terry Avenue North, Seattle, WA, 98109-5263, USA
| | - Lu Wei
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E California Blvd, Pasadena, CA, 91125, USA
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38
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Wolstenholme CH, Hu H, Ye S, Funk BE, Jain D, Hsiung CH, Ning G, Liu Y, Li X, Zhang X. AggFluor: Fluorogenic Toolbox Enables Direct Visualization of the Multi-Step Protein Aggregation Process in Live Cells. J Am Chem Soc 2020; 142:17515-17523. [PMID: 32915553 DOI: 10.1021/jacs.0c07245] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Aberrantly processed or mutant proteins misfold and assemble into a variety of soluble oligomers and insoluble aggregates, a process that is associated with an increasing number of diseases that are not curable or manageable. Herein, we present a chemical toolbox, AggFluor, that allows for live cell imaging and differentiation of complex aggregated conformations in live cells. Based on the chromophore core of green fluorescent proteins, AggFluor is comprised of a series of molecular rotor fluorophores that span a wide range of viscosity sensitivity. As a result, these compounds exhibit differential turn-on fluorescence when incorporated in either soluble oligomers or insoluble aggregates. This feature allows us to develop, for the first time, a dual-color imaging strategy to distinguish unfolded protein oligomers from insoluble aggregates in live cells. Furthermore, we have demonstrated how small molecule proteostasis regulators can drive formation and disassembly of protein aggregates in both conformational states. In summary, AggFluor is the first set of rationally designed molecular rotor fluorophores that evenly cover a wide range of viscosity sensitivities. This set of fluorescent probes not only change the status quo of current imaging methods to visualize protein aggregation in live cells but also can be generally applied to study other biological processes that involve local viscosity changes with temporal and spatial resolutions.
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39
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High-throughput screening for high-efficiency small-molecule biosynthesis. Metab Eng 2020; 63:102-125. [PMID: 33017684 DOI: 10.1016/j.ymben.2020.09.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/31/2020] [Accepted: 09/01/2020] [Indexed: 01/14/2023]
Abstract
Systems metabolic engineering faces the formidable task of rewiring microbial metabolism to cost-effectively generate high-value molecules from a variety of inexpensive feedstocks for many different applications. Because these cellular systems are still too complex to model accurately, vast collections of engineered organism variants must be systematically created and evaluated through an enormous trial-and-error process in order to identify a manufacturing-ready strain. The high-throughput screening of strains to optimize their scalable manufacturing potential requires execution of many carefully controlled, parallel, miniature fermentations, followed by high-precision analysis of the resulting complex mixtures. This review discusses strategies for the design of high-throughput, small-scale fermentation models to predict improved strain performance at large commercial scale. Established and promising approaches from industrial and academic groups are presented for both cell culture and analysis, with primary focus on microplate- and microfluidics-based screening systems.
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40
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Investigating the Structure of Neurotoxic Protein Aggregates Inside Cells. Trends Cell Biol 2020; 30:951-966. [PMID: 32981805 DOI: 10.1016/j.tcb.2020.08.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/13/2020] [Accepted: 08/17/2020] [Indexed: 12/22/2022]
Abstract
Neurodegenerative diseases affect the lives of millions of people across the world, being particularly prevalent in the aging population. Despite huge research efforts, conclusive insights into the disease mechanisms are still lacking. Therefore, therapeutic strategies are limited to symptomatic treatments. A common histopathological hallmark of many neurodegenerative diseases is the presence of large pathognomonic protein aggregates, but their role in the disease pathology is unclear and subject to controversy. Here, we discuss imaging methods allowing investigation of these structures within their cellular environment: conventional electron microscopy (EM), super-resolution light microscopy (SR-LM), and cryo-electron tomography (cryo-ET). Multidisciplinary approaches are key for understanding neurodegenerative diseases and may contribute to the development of effective treatments. For simplicity, we focus on huntingtin aggregates, characteristic of Huntington's disease.
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41
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Minoshima W, Masui K, Tani T, Nawa Y, Fujita S, Ishitobi H, Hosokawa C, Inouye Y. Deuterated Glutamate-Mediated Neuronal Activity on Micro-Electrode Arrays. MICROMACHINES 2020; 11:mi11090830. [PMID: 32878218 PMCID: PMC7569784 DOI: 10.3390/mi11090830] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/21/2020] [Accepted: 08/28/2020] [Indexed: 11/16/2022]
Abstract
The excitatory synaptic transmission is mediated by glutamate in neuronal networks of the mammalian brain. In addition to the synaptic glutamate, extra-synaptic glutamate is known to modulate the neuronal activity. In neuronal networks, glutamate uptake is an important role of neurons and glial cells for lowering the concentration of extracellular glutamate and to avoid the excitotoxicity by glutamate. Monitoring the spatial distribution of intracellular glutamate is important to study the uptake of glutamate, but the approach has been hampered by the absence of appropriate glutamate analogs that report the localization of glutamate. Deuterium-labeled glutamate (GLU-D) is a promising tracer for monitoring the intracellular concentration of glutamate, but physiological properties of GLU-D have not been studied. Here we study the effects of extracellular GLU-D for the neuronal activity by using primary cultured rat hippocampal neurons that form neuronal networks on microelectrodes array. The frequency of firing in the spontaneous activity of neurons increased with the increasing concentration of extracellular GLU-D. The frequency of synchronized burst activity in neurons increased similarly as we observed in the spontaneous activity. These changes of the neuronal activity with extracellular GLU-D were suppressed by antagonists of glutamate receptors. These results suggest that GLU-D can be used as an analog of glutamate with equivalent effects for facilitating the neuronal activity. We anticipate GLU-D developing as a promising analog of glutamate for studying the dynamics of glutamate during neuronal activity.
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Affiliation(s)
- Wataru Minoshima
- AIST–Osaka University Advanced Photonics and Biosensing Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology, AIST, Osaka 565-0871, Japan; (W.M.); (K.M.); (Y.N.); (S.F.); (H.I.)
- Graduate School of Frontier Biosciences, Osaka University, Osaka 565-0871, Japan
| | - Kyoko Masui
- AIST–Osaka University Advanced Photonics and Biosensing Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology, AIST, Osaka 565-0871, Japan; (W.M.); (K.M.); (Y.N.); (S.F.); (H.I.)
- Graduate School of Frontier Biosciences, Osaka University, Osaka 565-0871, Japan
| | - Tomomi Tani
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Ikeda 563-0026, Japan;
| | - Yasunori Nawa
- AIST–Osaka University Advanced Photonics and Biosensing Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology, AIST, Osaka 565-0871, Japan; (W.M.); (K.M.); (Y.N.); (S.F.); (H.I.)
- Department of Applied Physics, Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan
| | - Satoshi Fujita
- AIST–Osaka University Advanced Photonics and Biosensing Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology, AIST, Osaka 565-0871, Japan; (W.M.); (K.M.); (Y.N.); (S.F.); (H.I.)
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Ikeda 563-0026, Japan;
- Department of Applied Physics, Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan
| | - Hidekazu Ishitobi
- AIST–Osaka University Advanced Photonics and Biosensing Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology, AIST, Osaka 565-0871, Japan; (W.M.); (K.M.); (Y.N.); (S.F.); (H.I.)
- Graduate School of Frontier Biosciences, Osaka University, Osaka 565-0871, Japan
- Department of Applied Physics, Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan
| | - Chie Hosokawa
- AIST–Osaka University Advanced Photonics and Biosensing Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology, AIST, Osaka 565-0871, Japan; (W.M.); (K.M.); (Y.N.); (S.F.); (H.I.)
- Department of Chemistry, Division of Molecular Materials Science, Graduate School of Science, Osaka City University, Osaka 558-8585, Japan
- Correspondence: (C.H.); (Y.I.); Tel.: +81-6-6605-3700 (C.H.); +81-6-6879-4615 (Y.I.)
| | - Yasushi Inouye
- AIST–Osaka University Advanced Photonics and Biosensing Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology, AIST, Osaka 565-0871, Japan; (W.M.); (K.M.); (Y.N.); (S.F.); (H.I.)
- Graduate School of Frontier Biosciences, Osaka University, Osaka 565-0871, Japan
- Department of Applied Physics, Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan
- Correspondence: (C.H.); (Y.I.); Tel.: +81-6-6605-3700 (C.H.); +81-6-6879-4615 (Y.I.)
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42
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Burns KH, Srivastava P, Elles CG. Absolute Cross Sections of Liquids from Broadband Stimulated Raman Scattering with Femtosecond and Picosecond Pulses. Anal Chem 2020; 92:10686-10692. [PMID: 32598135 DOI: 10.1021/acs.analchem.0c01785] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Broadband stimulated Raman scattering (SRS) is often observed in applications that use nonlinear spectroscopy to probe the composition or dynamics of complex systems. Whether the SRS response is measured intentionally or unintentionally, as a background signal, the relative scattering intensities provide a quantitative measure of the population profile of target molecules. Solvent scattering is a valuable internal reference for determining absolute concentrations in these applications, but accurate cross sections have been reported for only a limited number of transitions in select solvents and were measured using spontaneous Raman scattering with narrowband continuous wave or nanosecond light sources. This work reports the measurement and analysis of absolute Raman scattering cross sections spanning the frequency range of 500-4000 cm-1 for cyclohexane, DMSO, acetonitrile, methanol, water, benzene, and toluene using broadband SRS with femtosecond and picosecond Raman pump pulses at 488 nm. Varying the duration of the Raman pump pulses from ∼80 fs to >1 ps confirms that the cross sections are independent of the spectral bandwidth across the range of ∼250 to <20 cm-1. The cross sections and depolarization ratios measured using broadband SRS agree with the limited number of previously reported values, after accounting for overlapping transitions in the lower-resolution femtosecond and picosecond spectra. The SRS cross sections reported here can be used with confidence as internal reference standards for a wide range of applications, including nonlinear spectroscopy and coherent microscopy measurements using ultrafast lasers.
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Affiliation(s)
- Kristen H Burns
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Prasenjit Srivastava
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
| | - Christopher G Elles
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, United States
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Sun DE, Chen X. Raman Imaging Shines a Light on Neurodegenerative Disorders. ACS CENTRAL SCIENCE 2020; 6:459-460. [PMID: 32341993 PMCID: PMC7181325 DOI: 10.1021/acscentsci.0c00267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Affiliation(s)
- De-en Sun
- College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Xing Chen
- College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
- Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
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