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Chin M, Patwardhan AR, Ang KH, Wang AL, Alquezar C, Welch M, Nguyen PT, Grabe M, Molofsky AV, Arkin MR, Kao AW. Genetically Encoded, pH-Sensitive mTFP1 Biosensor for Probing Lysosomal pH. ACS Sens 2021; 6:2168-2180. [PMID: 34102054 PMCID: PMC8240087 DOI: 10.1021/acssensors.0c02318] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 04/08/2021] [Indexed: 12/15/2022]
Abstract
Lysosomes are important sites for macromolecular degradation, defined by an acidic lumenal pH of ∼4.5. To better understand lysosomal pH, we designed a novel, genetically encoded, fluorescent protein (FP)-based pH biosensor called Fluorescence Indicator REporting pH in Lysosomes (FIRE-pHLy). This biosensor was targeted to lysosomes with lysosomal-associated membrane protein 1 (LAMP1) and reported lumenal pH between 3.5 and 6.0 with monomeric teal fluorescent protein 1 (mTFP1), a bright cyan pH-sensitive FP variant with a pKa of 4.3. Ratiometric quantification was enabled with cytosolically oriented mCherry using high-content quantitative imaging. We expressed FIRE-pHLy in several cellular models and quantified the alkalinizing response to bafilomycin A1, a specific V-ATPase inhibitor. In summary, we have engineered FIRE-pHLy, a specific, robust, and versatile lysosomal pH biosensor, that has broad applications for investigating pH dynamics in aging- and lysosome-related diseases, as well as in lysosome-based drug discovery.
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Affiliation(s)
- Marcus
Y. Chin
- Memory
and Aging Center, Department of Neurology, University of California, San Francisco, California 94158, United States
- Small
Molecule Discovery Center, Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143, United States
| | - Anand R. Patwardhan
- Memory
and Aging Center, Department of Neurology, University of California, San Francisco, California 94158, United States
| | - Kean-Hooi Ang
- Small
Molecule Discovery Center, Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143, United States
| | - Austin L. Wang
- Memory
and Aging Center, Department of Neurology, University of California, San Francisco, California 94158, United States
| | - Carolina Alquezar
- Memory
and Aging Center, Department of Neurology, University of California, San Francisco, California 94158, United States
| | - Mackenzie Welch
- Memory
and Aging Center, Department of Neurology, University of California, San Francisco, California 94158, United States
| | - Phi T. Nguyen
- Weill
Institute for Neurosciences, Department of Psychiatry, University of California, San Francisco, California 94158, United States
| | - Michael Grabe
- Cardiovascular
Research Institute, Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94158, United States
| | - Anna V. Molofsky
- Weill
Institute for Neurosciences, Department of Psychiatry, University of California, San Francisco, California 94158, United States
| | - Michelle R. Arkin
- Small
Molecule Discovery Center, Department of Pharmaceutical Chemistry, University of California, San Francisco, California 94143, United States
| | - Aimee W. Kao
- Memory
and Aging Center, Department of Neurology, University of California, San Francisco, California 94158, United States
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Kim H, Seong J. Fluorescent Protein-Based Autophagy Biosensors. MATERIALS 2021; 14:ma14113019. [PMID: 34199451 PMCID: PMC8199620 DOI: 10.3390/ma14113019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 05/28/2021] [Accepted: 05/30/2021] [Indexed: 11/16/2022]
Abstract
Autophagy is an essential cellular process of self-degradation for dysfunctional or unnecessary cytosolic constituents and organelles. Dysregulation of autophagy is thus involved in various diseases such as neurodegenerative diseases. To investigate the complex process of autophagy, various biochemical, chemical assays, and imaging methods have been developed. Here we introduce various methods to study autophagy, in particular focusing on the review of designs, principles, and limitations of the fluorescent protein (FP)-based autophagy biosensors. Different physicochemical properties of FPs, such as pH-sensitivity, stability, brightness, spectral profile, and fluorescence resonance energy transfer (FRET), are considered to design autophagy biosensors. These FP-based biosensors allow for sensitive detection and real-time monitoring of autophagy progression in live cells with high spatiotemporal resolution. We also discuss future directions utilizing an optobiochemical strategy to investigate the in-depth mechanisms of autophagy. These cutting-edge technologies will further help us to develop the treatment strategies of autophagy-related diseases.
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Affiliation(s)
- Heejung Kim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea;
- Department of Converging Science and Technology, Kyung Hee University, Seoul 02453, Korea
| | - Jihye Seong
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea;
- Department of Converging Science and Technology, Kyung Hee University, Seoul 02453, Korea
- Correspondence:
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53
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Visual pH Sensors: From a Chemical Perspective to New Bioengineered Materials. Molecules 2021; 26:molecules26102952. [PMID: 34065629 PMCID: PMC8156760 DOI: 10.3390/molecules26102952] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/11/2021] [Accepted: 05/14/2021] [Indexed: 02/05/2023] Open
Abstract
Many human activities and cellular functions depend upon precise pH values, and pH monitoring is considered a fundamental task. Colorimetric and fluorescence sensors for pH measurements are chemical and biochemical tools able to sense protons and produce a visible signal. These pH sensors are gaining widespread attention as non-destructive tools, visible to the human eye, that are capable of a real-time and in-situ response. Optical “visual” sensors are expanding researchers’ interests in many chemical contexts and are routinely used for biological, environmental, and medical applications. In this review we provide an overview of trending colorimetric, fluorescent, or dual-mode responsive visual pH sensors. These sensors include molecular synthetic organic sensors, metal organic frameworks (MOF), engineered sensing nanomaterials, and bioengineered sensors. We review different typological chemical entities of visual pH sensors, three-dimensional structures, and signaling mechanisms for pH sensing and applications; developed in the past five years. The progression of this review from simple organic molecules to biological macromolecules seeks to benefit beginners and scientists embarking on a project of pH sensing development, who needs background information and a quick update on advances in the field. Lessons learned from these tools will aid pH determination projects and provide new ways of thinking for cell bioimaging or other cutting-edge in vivo applications.
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54
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SCAMP5 plays a critical role in axonal trafficking and synaptic localization of NHE6 to adjust quantal size at glutamatergic synapses. Proc Natl Acad Sci U S A 2021; 118:2011371118. [PMID: 33372133 DOI: 10.1073/pnas.2011371118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Glutamate uptake into synaptic vesicles (SVs) depends on cation/H+ exchange activity, which converts the chemical gradient (ΔpH) into membrane potential (Δψ) across the SV membrane at the presynaptic terminals. Thus, the proper recruitment of cation/H+ exchanger to SVs is important in determining glutamate quantal size, yet little is known about its localization mechanism. Here, we found that secretory carrier membrane protein 5 (SCAMP5) interacted with the cation/H+ exchanger NHE6, and this interaction regulated NHE6 recruitment to glutamatergic presynaptic terminals. Protein-protein interaction analysis with truncated constructs revealed that the 2/3 loop domain of SCAMP5 is directly associated with the C-terminal region of NHE6. The use of optical imaging and electrophysiological recording showed that small hairpin RNA-mediated knockdown (KD) of SCAMP5 or perturbation of SCAMP5/NHE6 interaction markedly inhibited axonal trafficking and the presynaptic localization of NHE6, leading to hyperacidification of SVs and a reduction in the quantal size of glutamate release. Knockout of NHE6 occluded the effect of SCAMP5 KD without causing additional defects. Together, our results reveal that as a key regulator of axonal trafficking and synaptic localization of NHE6, SCAMP5 could adjust presynaptic strength by regulating quantal size at glutamatergic synapses. Since both proteins are autism candidate genes, the reduced quantal size by interrupting their interaction may underscore synaptic dysfunction observed in autism.
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55
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Ogasawara H, Tanaka Y, Taki M, Yamaguchi S. Late-stage functionalisation of alkyne-modified phospha-xanthene dyes: lysosomal imaging using an off-on-off type of pH probe. Chem Sci 2021; 12:7902-7907. [PMID: 34168843 PMCID: PMC8188471 DOI: 10.1039/d1sc01705e] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 04/30/2021] [Indexed: 12/16/2022] Open
Abstract
Near-infrared (NIR) fluorescent molecules are of great importance for the visualisation of biological processes. Among the most promising dye scaffolds for this purpose are P[double bond, length as m-dash]O-substituted phospha-xanthene (POX) dyes, which show NIR emission with high photostability. Their practical utility for in vitro and in vivo imaging has recently been demonstrated. Although classical modification methods have been used to produce POX-based fluorescent probes, it is still a challenge to introduce additional functional groups to control the localisation of the probe in cells. Herein, we report on the development of POXs that bear a 4-ethynylphenyl group on the phosphorus atom. These dyes can subsequently be functionalised with azide-tagged biomolecules via a late-stage Cu-catalysed azide/alkyne cycloaddition (CuAAC) reaction, thus achieving target-selective labelling. To demonstrate the practical utility of the functionalised POXs, we designed a sophisticated NIR probe that exhibits a bell-shaped off-on-off pH-response and is able to assess the degree of endosomal maturation.
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Affiliation(s)
- Hiroaki Ogasawara
- Department of Chemistry, Graduate School of Science, Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University Furo, Chikusa Nagoya 464-8602 Japan
| | - Yoshiki Tanaka
- Department of Chemistry, Graduate School of Science, Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University Furo, Chikusa Nagoya 464-8602 Japan
| | - Masayasu Taki
- Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University Furo, Chikusa Nagoya 464-8601 Japan
| | - Shigehiro Yamaguchi
- Department of Chemistry, Graduate School of Science, Integrated Research Consortium on Chemical Sciences (IRCCS), Nagoya University Furo, Chikusa Nagoya 464-8602 Japan
- Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University Furo, Chikusa Nagoya 464-8601 Japan
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56
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Scales JL, Koroma DC, Oancea E. Single organelle measurements of melanosome pH using the novel ratiometric indicator RpHiMEL. Methods Enzymol 2021; 654:315-344. [PMID: 34120720 DOI: 10.1016/bs.mie.2021.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Melanocytes are specialized cells that produce melanin pigments responsible for skin, hair, and eye pigmentation. The synthesis and storage of melanin occurs in unique lysosome-related organelles called melanosomes, which regulate melanin production via complex regulatory mechanisms. Maintenance of the melanosome luminal ionic environment and pH is crucial for proper function of the main melanogenic enzymes. Defects in genes encoding pH-regulating melanosomal proteins result in oculocutaneous albinism, which is characterized by hypopigmentation, impaired vision, and increased susceptibility to skin and eye cancers. We recently uncovered several ion channels and transporters that modulate melanin synthesis by acidifying or neutralizing the luminal pH of melanosomes. However, our understanding of how melanosomes and other related organelles maintain their luminal pH is far from complete. The study of melanosome pH regulation requires robust imaging and quantification tools. Despite recent advances in the development of such methods, many limitations remain, particularly for quantitative analysis of individual organelle pH. In this chapter, we will provide an overview of the available methods used for melanosome pH determination, including their advantages, limitations, and challenges. To address the critical, unmet need for reliable melanosome pH quantification tools, we engineered a novel genetically encoded, ratiometric pH sensor for melanosomes that we named RpHiMEL. Here, we describe the design and optimization of RpHiMEL, and provide a pH quantification method for individual melanosomes in live cells. We demonstrate that RpHiMEL is a highly versatile tool with the potential to advance our understanding of pH regulation in melanosomes and related organelles.
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Affiliation(s)
- Jessica L Scales
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI, United States
| | - Donald C Koroma
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI, United States
| | - Elena Oancea
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI, United States.
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Bischof H, Burgstaller S, Springer A, Matt L, Rauter T, Bachkönig OA, Schmidt T, Groschner K, Schindl R, Madl T, Plesnila N, Lukowski R, Graier WF, Malli R. Potassium ions promote hexokinase-II dependent glycolysis. iScience 2021; 24:102346. [PMID: 33870140 PMCID: PMC8047173 DOI: 10.1016/j.isci.2021.102346] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 02/22/2021] [Accepted: 03/18/2021] [Indexed: 02/06/2023] Open
Abstract
High expression levels of mitochondria-associated hexokinase-II (HKII) represent a hallmark of metabolically highly active cells such as fast proliferating cancer cells. Typically, the enzyme provides a crucial metabolic switch towards aerobic glycolysis. By imaging metabolic activities on the single-cell level with genetically encoded fluorescent biosensors, we here demonstrate that HKII activity requires intracellular K+. The K+ dependency of glycolysis in cells expressing HKII was confirmed in cell populations using extracellular flux analysis and nuclear magnetic resonance-based metabolomics. Reductions of intracellular K+ by gramicidin acutely disrupted HKII-dependent glycolysis and triggered energy stress pathways, while K+ re-addition promptly restored glycolysis-dependent adenosine-5'-triphosphate generation. Moreover, expression and activation of KV1.3, a voltage-gated K+ channel, lowered cellular K+ content and the glycolytic activity of HEK293 cells. Our findings unveil K+ as an essential cofactor of HKII and provide a mechanistic link between activities of distinct K+ channels and cell metabolism.
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Affiliation(s)
- Helmut Bischof
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Auf der Morgenstelle 8, 72076 Tuebingen, Germany
| | - Sandra Burgstaller
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- Department of Molecular Biology, Interfaculty Institute for Cell Biology, University of Tuebingen, Auf der Morgenstelle 15, 72076 Tuebingen, Germany
| | - Anna Springer
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Lucas Matt
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Auf der Morgenstelle 8, 72076 Tuebingen, Germany
| | - Thomas Rauter
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Olaf A. Bachkönig
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Tony Schmidt
- Gottfried Schatz Research Center, Biophysics, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
| | - Klaus Groschner
- Gottfried Schatz Research Center, Biophysics, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- BioTechMed-Graz, Mozartgasse 12/II, 8010 Graz, Austria
| | - Rainer Schindl
- Gottfried Schatz Research Center, Biophysics, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- BioTechMed-Graz, Mozartgasse 12/II, 8010 Graz, Austria
| | - Tobias Madl
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- BioTechMed-Graz, Mozartgasse 12/II, 8010 Graz, Austria
| | - Nikolaus Plesnila
- Laboratory of Experimental Stroke Research, Institute for Stroke and Dementia Research, University of Munich Medical Center, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Robert Lukowski
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Auf der Morgenstelle 8, 72076 Tuebingen, Germany
| | - Wolfgang F. Graier
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- BioTechMed-Graz, Mozartgasse 12/II, 8010 Graz, Austria
| | - Roland Malli
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria
- BioTechMed-Graz, Mozartgasse 12/II, 8010 Graz, Austria
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58
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Sánchez-Navarro M. Advances in peptide-mediated cytosolic delivery of proteins. Adv Drug Deliv Rev 2021; 171:187-198. [PMID: 33561452 DOI: 10.1016/j.addr.2021.02.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/26/2021] [Accepted: 02/03/2021] [Indexed: 02/06/2023]
Abstract
The number of protein-based drugs is exponentially increasing. However, development of protein therapeutics against intracellular targets is hampered by the lack of efficient cytosolic delivery strategies. In recent years, the use of cell-penetrating peptides has been proposed as a strategy to promote protein internalization. In this article, we provide the reader with a succinct update on the strategies exploited to enable peptide-mediated cytosolic delivery of proteins. First, we analyse the various methods available for delivery. We then describe the most popular and the in vitro assays designed to assess the intracellular distribution of protein cargo.
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59
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Harper CB, Smillie KJ. Current molecular approaches to investigate pre-synaptic dysfunction. J Neurochem 2021; 157:107-129. [PMID: 33544872 DOI: 10.1111/jnc.15316] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 12/19/2022]
Abstract
Over the course of the last few decades it has become clear that many neurodevelopmental and neurodegenerative disorders have a synaptic defect, which contributes to pathogenicity. A rise in new techniques, and in particular '-omics'-based methods providing large datasets, has led to an increase in potential proteins and pathways implicated in synaptic function and related disorders. Additionally, advancements in imaging techniques have led to the recent discovery of alternative modes of synaptic vesicle recycling. This has resulted in a lack of clarity over the precise role of different pathways in maintaining synaptic function and whether these new pathways are dysfunctional in neurodevelopmental and neurodegenerative disorders. A greater understanding of the molecular detail of pre-synaptic function in health and disease is key to targeting new proteins and pathways for novel treatments and the variety of new techniques currently available provides an ideal opportunity to investigate these functions. This review focuses on techniques to interrogate pre-synaptic function, concentrating mainly on synaptic vesicle recycling. It further examines techniques to determine the underlying molecular mechanism of pre-synaptic dysfunction and discusses methods to identify molecular targets, along with protein-protein interactions and cellular localization. In combination, these techniques will provide an expanding and more complete picture of pre-synaptic function. With the application of recent technological advances, we are able to resolve events with higher spatial and temporal resolution, leading research towards a greater understanding of dysfunction at the presynapse and the role it plays in pathogenicity.
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Affiliation(s)
- Callista B Harper
- Centre for Discovery Brain Sciences, University of Edinburgh, Scotland, UK
| | - Karen J Smillie
- Centre for Discovery Brain Sciences, University of Edinburgh, Scotland, UK
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60
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Deng H, Li J, Zhou Y, Xia Y, Chen C, Zhou Z, Wu H, Wang P, Zhou S. Genetic engineering of circularly permuted yellow fluorescent protein reveals intracellular acidification in response to nitric oxide stimuli. Redox Biol 2021; 41:101943. [PMID: 33752109 PMCID: PMC8005830 DOI: 10.1016/j.redox.2021.101943] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 03/09/2021] [Accepted: 03/09/2021] [Indexed: 02/07/2023] Open
Abstract
Intracellular pH (pHi) is a crucial parameter in cell biology; thus, a series of pH probes have been developed to determine pHi changes in living cells. However, more sensitive and non-perturbing ratiometric pH probes are needed for accurate pHi measurements. While the fluorescence of circular permutated YFP (cpYFP) is hypersensitive to pH changes due to its intrinsic properties, the single excitation peak of this protein restricts its capacity of becoming a rational type of pH sensor. Herein, we collected several cpYFP-based probes with dual excitation peaks and constructed their corresponding loss-of-function mutants to screen for a potential competent pH probe. The most sensitive probe was named NocPer. NocPer consists of cpYFP inserted into inactive-mutated GAF and AAA+, which are two regulatory domains of E. coli NorR, a nitric oxide (NO)-specific transcription factor. Fluorescence emission of NocPer peaks at 517 nm while exhibiting dual excitation peaks at 420 and 495 nm, which can be used for ratiometric imaging. This new pH sensor has a large ratio response dynamic (pH range of 7.0–11.0), which covers the physiological pH range (pH 7.0–8.0), and exhibits an approximately 3-fold higher fluorescent signal in response to a pH increase from 7.0 to 8.0 than that of pHluorin. Using NocPer, we discovered a new biological phenomenon in which NO exposure decreases the E. coli pHi, which led to the hypothesis that pathogens decrease their own pHi during infection. Further, we elucidated that the NO-induced inhibition of cytochrome c oxidase in the respiratory chain is responsible for the decline in pHi, which might represent a protective strategy of E. coli under NO stress conditions. Our results demonstrated that NocPer is a ratiometric pH probe with high sensitivity for the physiological pH range. Circular permutated YFP was modified to be an a supersensitive and ratiometric pH probe NocPer. Nitric oxide (NO) lowering intracellular pH (pHi) was discovered as a new biological phenomenon. NO-induced inhibition of cytochrome c oxidase is responsible for the decline in pHi. pHi decrease by NO might represent a bacterial protective mechanism.
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Affiliation(s)
- Haitao Deng
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
| | - Jingyi Li
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
| | - Yao Zhou
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
| | - Yang Xia
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
| | - Chao Chen
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
| | - Zhemin Zhou
- Key Laboratory of Industrial Biotechnology (Ministry of Education), School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu, 214122, China
| | - Hui Wu
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
| | - Ping Wang
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China
| | - Shengmin Zhou
- State Key Laboratory of Bioreactor Engineering, School of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China.
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61
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Ma Y, Liu Y, Wang Y, Zhang F, Yang D. A novel sodium-fluorescent crystal. ROYAL SOCIETY OPEN SCIENCE 2021; 8:201987. [PMID: 33959353 PMCID: PMC8074955 DOI: 10.1098/rsos.201987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 02/04/2021] [Indexed: 06/12/2023]
Abstract
In this work, a novel sodium-fluorescent crystal (Na-FS) was synthesized from 4-dimethylaminobenzoic acid and sodium hydroxide by one-pot hydrothermal method. The structure and conformation of Na-FS were confirmed by single-crystal X-ray diffraction and scanning electron microscope, and the optical properties were studied by fluorescence spectrometer. The results showed that: Na-FS was a triclinic crystal, space group was P-1, cell parameters a, b and c were 10.5113(3), 15.9198(5) and 15.9560(5) Å, respectively, and the number of independent atoms Z in a structure cell was two. Additionally, Na-FS has a blue fluorescence emission (around 360 nm under excited at the range of 230-300 nm) with great photostability and photobleaching resistance, and the quantum yield of Na-FS is 30.58%.
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Affiliation(s)
- Yunsu Ma
- School of Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu 22004, People's Republic of China
| | - Yongjie Liu
- School of Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu 22004, People's Republic of China
| | - Yuan Wang
- School of Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu 22004, People's Republic of China
| | - Fan Zhang
- School of Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu 22004, People's Republic of China
| | - Dongzhi Yang
- School of Pharmacy, Xuzhou Medical University, Xuzhou, Jiangsu 22004, People's Republic of China
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Prasad S, Chandra A, Cavo M, Parasido E, Fricke S, Lee Y, D'Amone E, Gigli G, Albanese C, Rodriguez O, Del Mercato LL. Optical and magnetic resonance imaging approaches for investigating the tumour microenvironment: state-of-the-art review and future trends. NANOTECHNOLOGY 2021; 32:062001. [PMID: 33065554 DOI: 10.1088/1361-6528/abc208] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The tumour microenvironment (TME) strongly influences tumorigenesis and metastasis. Two of the most characterized properties of the TME are acidosis and hypoxia, both of which are considered hallmarks of tumours as well as critical factors in response to anticancer treatments. Currently, various imaging approaches exist to measure acidosis and hypoxia in the TME, including magnetic resonance imaging (MRI), positron emission tomography and optical imaging. In this review, we will focus on the latest fluorescent-based methods for optical sensing of cell metabolism and MRI as diagnostic imaging tools applied both in vitro and in vivo. The primary emphasis will be on describing the current and future uses of systems that can measure intra- and extra-cellular pH and oxygen changes at high spatial and temporal resolution. In addition, the suitability of these approaches for mapping tumour heterogeneity, and assessing response or failure to therapeutics will also be covered.
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Affiliation(s)
- Saumya Prasad
- Institute of Nanotechnology, National Research Council (CNR-NANOTEC), c/o Campus Ecotekne, via Monteroni, 73100, Lecce, Italy
| | - Anil Chandra
- Institute of Nanotechnology, National Research Council (CNR-NANOTEC), c/o Campus Ecotekne, via Monteroni, 73100, Lecce, Italy
| | - Marta Cavo
- Institute of Nanotechnology, National Research Council (CNR-NANOTEC), c/o Campus Ecotekne, via Monteroni, 73100, Lecce, Italy
| | - Erika Parasido
- Department of Oncology, Georgetown University Medical Center, Washington, DC, United States of America
- Center for Translational Imaging, Georgetown University Medical Center, Washington, DC, United States of America
| | - Stanley Fricke
- Department of Oncology, Georgetown University Medical Center, Washington, DC, United States of America
- Center for Translational Imaging, Georgetown University Medical Center, Washington, DC, United States of America
- Department of Radiology, Georgetown University Medical Center, Washington, DC, United States of America
| | - Yichien Lee
- Department of Oncology, Georgetown University Medical Center, Washington, DC, United States of America
| | - Eliana D'Amone
- Institute of Nanotechnology, National Research Council (CNR-NANOTEC), c/o Campus Ecotekne, via Monteroni, 73100, Lecce, Italy
| | - Giuseppe Gigli
- Institute of Nanotechnology, National Research Council (CNR-NANOTEC), c/o Campus Ecotekne, via Monteroni, 73100, Lecce, Italy
- Department of Mathematics and Physics 'Ennio De Giorgi', University of Salento, via Arnesano, 73100, Lecce, Italy
| | - Chris Albanese
- Department of Oncology, Georgetown University Medical Center, Washington, DC, United States of America
- Center for Translational Imaging, Georgetown University Medical Center, Washington, DC, United States of America
- Department of Radiology, Georgetown University Medical Center, Washington, DC, United States of America
| | - Olga Rodriguez
- Department of Oncology, Georgetown University Medical Center, Washington, DC, United States of America
- Center for Translational Imaging, Georgetown University Medical Center, Washington, DC, United States of America
| | - Loretta L Del Mercato
- Institute of Nanotechnology, National Research Council (CNR-NANOTEC), c/o Campus Ecotekne, via Monteroni, 73100, Lecce, Italy
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63
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Kim H, Ju J, Lee HN, Chun H, Seong J. Genetically Encoded Biosensors Based on Fluorescent Proteins. SENSORS (BASEL, SWITZERLAND) 2021; 21:795. [PMID: 33504068 PMCID: PMC7865379 DOI: 10.3390/s21030795] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/21/2021] [Accepted: 01/22/2021] [Indexed: 02/06/2023]
Abstract
Genetically encoded biosensors based on fluorescent proteins (FPs) allow for the real-time monitoring of molecular dynamics in space and time, which are crucial for the proper functioning and regulation of complex cellular processes. Depending on the types of molecular events to be monitored, different sensing strategies need to be applied for the best design of FP-based biosensors. Here, we review genetically encoded biosensors based on FPs with various sensing strategies, for example, translocation, fluorescence resonance energy transfer (FRET), reconstitution of split FP, pH sensitivity, maturation speed, and so on. We introduce general principles of each sensing strategy and discuss critical factors to be considered if available, then provide representative examples of these FP-based biosensors. These will help in designing the best sensing strategy for the successful development of new genetically encoded biosensors based on FPs.
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Affiliation(s)
- Hyunbin Kim
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea; (H.K.); (J.J.); (H.N.L.); (H.C.)
- Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Korea
| | - Jeongmin Ju
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea; (H.K.); (J.J.); (H.N.L.); (H.C.)
- Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Korea
| | - Hae Nim Lee
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea; (H.K.); (J.J.); (H.N.L.); (H.C.)
- Department of Converging Science and Technology, Kyung Hee University, Seoul 02453, Korea
| | - Hyeyeon Chun
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea; (H.K.); (J.J.); (H.N.L.); (H.C.)
| | - Jihye Seong
- Brain Science Institute, Korea Institute of Science and Technology (KIST), Seoul 02792, Korea; (H.K.); (J.J.); (H.N.L.); (H.C.)
- Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Korea
- Department of Converging Science and Technology, Kyung Hee University, Seoul 02453, Korea
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64
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Tannert A, Garcia Lopez J, Petkov N, Ivanova A, Peneva K, Neugebauer U. Lysosome-targeting pH indicator based on peri-fused naphthalene monoimide with superior stability for long term live cell imaging. J Mater Chem B 2021; 9:112-124. [DOI: 10.1039/d0tb02208j] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Lysosomal pH is altered in many pathophysiological conditions. We describe synthesis and spectral properties of a new lysosomal fluorescent marker dye suitable for microscopic evaluation of lysosomal distribution and pH changes.
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Affiliation(s)
- Astrid Tannert
- Leibniz Institute of Photonic Technology
- 07745 Jena
- Germany
- Center for Sepsis Control and Care
- Jena University Hospital
| | - Javier Garcia Lopez
- Institute of Organic Chemistry and Macromolecular Chemistry
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Jena Center of Soft Matter (JCSM)
| | - Nikolay Petkov
- Faculty of Chemistry and Pharmacy
- Sofia University “St. Kliment Ohridski”
- Sofia
- Bulgaria
| | - Anela Ivanova
- Faculty of Chemistry and Pharmacy
- Sofia University “St. Kliment Ohridski”
- Sofia
- Bulgaria
| | - Kalina Peneva
- Institute of Organic Chemistry and Macromolecular Chemistry
- Friedrich Schiller University Jena
- 07743 Jena
- Germany
- Jena Center of Soft Matter (JCSM)
| | - Ute Neugebauer
- Leibniz Institute of Photonic Technology
- 07745 Jena
- Germany
- Center for Sepsis Control and Care
- Jena University Hospital
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65
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Pratt EP, Anson KJ, Tapper JK, Simpson DM, Palmer AE. Systematic Comparison of Vesicular Targeting Signals Leads to the Development of Genetically Encoded Vesicular Fluorescent Zn 2+ and pH Sensors. ACS Sens 2020; 5:3879-3891. [PMID: 33305939 DOI: 10.1021/acssensors.0c01231] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Genetically encoded fluorescent sensors have been widely used to illuminate secretory vesicle dynamics and the vesicular lumen, including Zn2+ and pH, in living cells. However, vesicular sensors have a tendency to mislocalize and are susceptible to the acidic intraluminal pH. In this study, we performed a systematic comparison of five different vesicular proteins to target the fluorescent protein mCherry and a Zn2+ Förster resonance energy transfer (FRET) sensor to secretory vesicles. We found that motifs derived from vesicular cargo proteins, including chromogranin A (CgA), target vesicular puncta with greater efficacy than transmembrane proteins. To characterize vesicular Zn2+ levels, we developed CgA-Zn2+ FRET sensor fusions with existing sensors ZapCY1 and eCALWY-4 and characterized subcellular localization and the influence of pH on sensor performance. We simultaneously monitored Zn2+ and pH in individual secretory vesicles by leveraging the acceptor fluorescent protein as a pH sensor and found that pH influenced FRET measurements in situ. While unable to characterize vesicular Zn2+ at the single-vesicle level, we were able to monitor Zn2+ dynamics in populations of vesicles and detected high vesicular Zn2+ in MIN6 cells compared to lower levels in the prostate cancer cell line LnCaP. The combination of CgA-ZapCY1 and CgA-eCALWY-4 allows for measurement of Zn2+ from pM to nM ranges.
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Affiliation(s)
- Evan P.S. Pratt
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, UCB 596, Boulder, Colorado 80309-0401, United States
| | - Kelsie J. Anson
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, UCB 596, Boulder, Colorado 80309-0401, United States
| | - Justin K. Tapper
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, UCB 596, Boulder, Colorado 80309-0401, United States
| | - David M. Simpson
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, UCB 596, Boulder, Colorado 80309-0401, United States
| | - Amy E. Palmer
- Department of Biochemistry and BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Ave, UCB 596, Boulder, Colorado 80309-0401, United States
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66
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Li J, Huang X, Zhao X, Chen L, Yan X. pH‐Responsive Torpedo‐Like Persistent Luminescence Nanoparticles for Autofluorescence‐Free Biosensing and High‐Level Information Encryption. Angew Chem Int Ed Engl 2020; 60:2398-2405. [DOI: 10.1002/anie.202011553] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Indexed: 01/09/2023]
Affiliation(s)
- Juan Li
- State Key Laboratory of Food Science and Technology Jiangnan University Wuxi 214122 China
- International Joint Laboratory on Food Safety Jiangnan University Wuxi 214122 China
- Institute of Analytical Food Safety School of Food Science and Technology Jiangnan University Wuxi 214122 China
| | - Xiaolin Huang
- State Key Laboratory of Food Science and Technology School of Food Science and Technology Nanchang University Nanchang 330047 China
| | - Xu Zhao
- State Key Laboratory of Food Science and Technology Jiangnan University Wuxi 214122 China
- International Joint Laboratory on Food Safety Jiangnan University Wuxi 214122 China
- Institute of Analytical Food Safety School of Food Science and Technology Jiangnan University Wuxi 214122 China
| | - Li‐Jian Chen
- State Key Laboratory of Food Science and Technology Jiangnan University Wuxi 214122 China
- International Joint Laboratory on Food Safety Jiangnan University Wuxi 214122 China
- Institute of Analytical Food Safety School of Food Science and Technology Jiangnan University Wuxi 214122 China
| | - Xiu‐Ping Yan
- State Key Laboratory of Food Science and Technology Jiangnan University Wuxi 214122 China
- International Joint Laboratory on Food Safety Jiangnan University Wuxi 214122 China
- Institute of Analytical Food Safety School of Food Science and Technology Jiangnan University Wuxi 214122 China
- Key Laboratory of Synthetic and Biological Colloids Ministry of Education Jiangnan University Wuxi 214122 China
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67
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Li J, Huang X, Zhao X, Chen L, Yan X. pH‐Responsive Torpedo‐Like Persistent Luminescence Nanoparticles for Autofluorescence‐Free Biosensing and High‐Level Information Encryption. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202011553] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Juan Li
- State Key Laboratory of Food Science and Technology Jiangnan University Wuxi 214122 China
- International Joint Laboratory on Food Safety Jiangnan University Wuxi 214122 China
- Institute of Analytical Food Safety School of Food Science and Technology Jiangnan University Wuxi 214122 China
| | - Xiaolin Huang
- State Key Laboratory of Food Science and Technology School of Food Science and Technology Nanchang University Nanchang 330047 China
| | - Xu Zhao
- State Key Laboratory of Food Science and Technology Jiangnan University Wuxi 214122 China
- International Joint Laboratory on Food Safety Jiangnan University Wuxi 214122 China
- Institute of Analytical Food Safety School of Food Science and Technology Jiangnan University Wuxi 214122 China
| | - Li‐Jian Chen
- State Key Laboratory of Food Science and Technology Jiangnan University Wuxi 214122 China
- International Joint Laboratory on Food Safety Jiangnan University Wuxi 214122 China
- Institute of Analytical Food Safety School of Food Science and Technology Jiangnan University Wuxi 214122 China
| | - Xiu‐Ping Yan
- State Key Laboratory of Food Science and Technology Jiangnan University Wuxi 214122 China
- International Joint Laboratory on Food Safety Jiangnan University Wuxi 214122 China
- Institute of Analytical Food Safety School of Food Science and Technology Jiangnan University Wuxi 214122 China
- Key Laboratory of Synthetic and Biological Colloids Ministry of Education Jiangnan University Wuxi 214122 China
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68
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Fremy G, Raibaut L, Cepeda C, Sanson M, Boujut M, Sénèque O. A novel DOTA-like building block with a picolinate arm for the synthesis of lanthanide complex-peptide conjugates with improved luminescence properties. J Inorg Biochem 2020; 213:111257. [DOI: 10.1016/j.jinorgbio.2020.111257] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 09/07/2020] [Accepted: 09/09/2020] [Indexed: 12/28/2022]
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69
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Luminescent probes for luminescence lifetime sensing and imaging in live cells: a narrative review. JOURNAL OF BIO-X RESEARCH 2020. [DOI: 10.1097/jbr.0000000000000081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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70
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Rauter T, Burgstaller S, Gottschalk B, Ramadani-Muja J, Bischof H, Hay JC, Graier WF, Malli R. ER-to-Golgi Transport in HeLa Cells Displays High Resilience to Ca 2+ and Energy Stresses. Cells 2020; 9:E2311. [PMID: 33080790 PMCID: PMC7603030 DOI: 10.3390/cells9102311] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/09/2020] [Accepted: 10/16/2020] [Indexed: 02/07/2023] Open
Abstract
One third of all human proteins are either transmembrane or soluble secretory proteins that first target the endoplasmic reticulum (ER). These proteins subsequently leave the ER and enter the Golgi apparatus via ER-Golgi intermediate vesicular structures. Live-cell imaging of cargos fused to fluorescent proteins (FPs) enables the high-resolution visualization and characterization of secretory transport processes. Here, we performed fluorescence time-lapse imaging to assess the Ca2+ and energy dependency of ER-to-Golgi transport in living HeLa cells, a cancer cell model which has been well investigated. Our data revealed that ER-to-Golgi transport remained highly efficient in the absence of ATP-generating substrates, despite clear reductions in cytosolic and mitochondrial ATP levels under these energy stress conditions. However, cell treatment with 2-deoxy-D-glucose (2-DG), which severely diminished subcellular ATP levels, abolished ER-to-Golgi transport. Interestingly, while 2-DG elevated cytosolic Ca2+ levels and reduced long-distance movements of glycosylphosphatidylinositol (GPI)-positive vesicles, robust short-term ER Ca2+ mobilizations, which strongly affected the motility of these vesicles, did not considerably impair ER-to-Golgi transport. In summary, we highlight that ER-to-Golgi transport in HeLa cells remains functional despite high energy and Ca2+ stress levels.
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Affiliation(s)
- Thomas Rauter
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria; (T.R.); (S.B.); (B.G.); (J.R.-M.); (H.B.); (W.F.G.)
| | - Sandra Burgstaller
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria; (T.R.); (S.B.); (B.G.); (J.R.-M.); (H.B.); (W.F.G.)
- Interfaculty Institute of Cell Biology, University of Tuebingen, Auf der Morgenstelle 15, 72076 Tuebingen, Germany
| | - Benjamin Gottschalk
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria; (T.R.); (S.B.); (B.G.); (J.R.-M.); (H.B.); (W.F.G.)
| | - Jeta Ramadani-Muja
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria; (T.R.); (S.B.); (B.G.); (J.R.-M.); (H.B.); (W.F.G.)
| | - Helmut Bischof
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria; (T.R.); (S.B.); (B.G.); (J.R.-M.); (H.B.); (W.F.G.)
- Department of Pharmacology, Toxicology and Clinical Pharmacy, Institute of Pharmacy, University of Tuebingen, Auf der Morgenstelle 8, 72076 Tuebingen, Germany
| | - Jesse C. Hay
- Division of Biological Sciences and Center for Structural and Functional Neuroscience, The University of Montana, 32 Campus Drive, HS 302A, Missoula, MT 59812-4824, USA;
| | - Wolfgang F. Graier
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria; (T.R.); (S.B.); (B.G.); (J.R.-M.); (H.B.); (W.F.G.)
- BioTechMed Graz, Mozartgasse 12/II, 8010 Graz, Austria
| | - Roland Malli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, 8010 Graz, Austria; (T.R.); (S.B.); (B.G.); (J.R.-M.); (H.B.); (W.F.G.)
- BioTechMed Graz, Mozartgasse 12/II, 8010 Graz, Austria
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71
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Roche B, Bumann D. Single-cell reporters for pathogen responses to antimicrobial host attacks. Curr Opin Microbiol 2020; 59:16-23. [PMID: 32810800 DOI: 10.1016/j.mib.2020.07.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/20/2020] [Accepted: 07/26/2020] [Indexed: 12/12/2022]
Abstract
Host-pathogen interactions are often heterogeneous involving individual encounters between host and pathogen cells with diverse molecular mechanisms, response networks, and diverging outcomes. Single-cell reporters can identify the various types of interactions and participating pathogen subsets, help to unravel underlying molecular mechanism, and determine individual outcomes and their impact on disease progression. In this review, we discuss reporters-based on fluorescent proteins. We present different types of reporters and their experimental advantages and challenges, and describe how different strategies can interrogate exposure to antimicrobial host mechanism, pathogen response, inflicted damage, and impact on pathogen fitness at the single-cell level. We find many gaps in available tools but also exciting avenues to address these issues.
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Affiliation(s)
- Béatrice Roche
- Biozentrum, University of Basel, CH-4056 Basel, Switzerland
| | - Dirk Bumann
- Biozentrum, University of Basel, CH-4056 Basel, Switzerland.
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72
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In Vitro Assays: Friends or Foes of Cell-Penetrating Peptides. Int J Mol Sci 2020; 21:ijms21134719. [PMID: 32630650 PMCID: PMC7369778 DOI: 10.3390/ijms21134719] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 06/24/2020] [Accepted: 07/01/2020] [Indexed: 12/20/2022] Open
Abstract
The cell membrane is a complex and highly regulated system that is composed of lipid bilayer and proteins. One of the main functions of the cell membrane is the regulation of cell entry. Cell-penetrating peptides (CPPs) are defined as peptides that can cross the plasma membrane and deliver their cargo inside the cell. The uptake of a peptide is determined by its sequence and biophysicochemical properties. At the same time, the uptake mechanism and efficiency are shown to be dependent on local peptide concentration, cell membrane lipid composition, characteristics of the cargo, and experimental methodology, suggesting that a highly efficient CPP in one system might not be as productive in another. To better understand the dependence of CPPs on the experimental system, we present a review of the in vitro assays that have been employed in the literature to evaluate CPPs and CPP-cargos. Our comprehensive review suggests that utilization of orthogonal assays will be more effective for deciphering the true ability of CPPs to translocate through the membrane and enter the cell cytoplasm.
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73
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Kuo JCH, Goudge MC, Metzloff AE, Huang LT, Colville MJ, Park S, Zipfel WR, Paszek MJ. Litmus-Body: A Molecularly Targeted Sensor for Cell-Surface pH Measurements. ACS Sens 2020; 5:1555-1566. [PMID: 32337979 DOI: 10.1021/acssensors.9b02080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Precise pH measurements in the immediate environment of receptors is essential for elucidating the mechanisms through which local pH changes associated with diseased phenotypes manifest into aberrant receptor function. However, current pH sensors lack the ability to localize and target specific receptor molecules required to make these measurements. Herein we present the Litmus-body, our recombinant protein-based pH sensor, which through fusion to an anti-IgG nanobody is capable of piggybacking on IgG antibodies for molecular targeting to specific proteins on the cell surface. By normalizing a pH-dependent green fluorescent protein to a long Stokes shift red fluorophore or fluorescent protein, we readily report pH independent of sensor concentration using a single 488 nm excitation. Our Litmus-body showed excellent responsiveness in solution, with a greater than 50-fold change across the regime of physiological pH. The sensor was further validated for use on live cells and shown to be specific to the protein of interest. In complex with our Litmus-body, cetuximab therapeutic antibody retained its functionality in binding and inhibiting ligand interaction of its target epidermal growth factor receptor (EGFR), triggering receptor-mediated endocytosis that allowed tracking of local pH from the cell surface through the endocytic pathway.
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Affiliation(s)
- Joe Chin-Hun Kuo
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Marc C. Goudge
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Ann E. Metzloff
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Ling-Ting Huang
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, United States
| | | | - Sangwoo Park
- Field of Biophysics, Cornell University, Ithaca, New York 14853, United States
| | - Warren R. Zipfel
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York 14853, United States
- Field of Biophysics, Cornell University, Ithaca, New York 14853, United States
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, United States
| | - Matthew J. Paszek
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, United States
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York 14853, United States
- Field of Biophysics, Cornell University, Ithaca, New York 14853, United States
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, United States
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74
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Rauter T, Depaoli MR, Bischof H, Graier WF, Malli R. Metabolic Profiling of Single Cancer Cells Using Mitochondrial ATP Probes. STAR Protoc 2020; 1:100048. [PMID: 33111094 PMCID: PMC7580088 DOI: 10.1016/j.xpro.2020.100048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The metabolic activity of cells is interrelated with cell signaling, functions, and fate. Uncontrolled cancer cell proliferation requires metabolic adaptations. Research focusing on understanding the characteristics of cell metabolism is crucial for the development of novel diagnostic and therapeutic strategies. Here, we describe protocols for the ATP profiling of single cancer cells by fluorescence live-cell imaging. In response to distinct metabolic inhibitions, we record individual mitochondrial ATP dynamics using established Förster resonance energy transfer-based genetically encoded fluorescent ATP probes. For complete details on the use and execution of this protocol, please refer to Depaoli et al. (2018).
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Affiliation(s)
- Thomas Rauter
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, Graz 8010, Austria,Corresponding author
| | - Maria R. Depaoli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, Graz 8010, Austria,Corresponding author
| | - Helmut Bischof
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, Graz 8010, Austria
| | - Wolfgang F. Graier
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, Graz 8010, Austria,BioTechMed, Graz, Austria,Corresponding author
| | - Roland Malli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Neue Stiftingtalstraße 6/6, Graz 8010, Austria,BioTechMed, Graz, Austria,Corresponding author
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75
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Ripoll C, Roldan M, Contreras-Montoya R, Diaz-Mochon JJ, Martin M, Ruedas-Rama MJ, Orte A. Mitochondrial pH Nanosensors for Metabolic Profiling of Breast Cancer Cell Lines. Int J Mol Sci 2020; 21:E3731. [PMID: 32466332 PMCID: PMC7279253 DOI: 10.3390/ijms21103731] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 05/21/2020] [Accepted: 05/22/2020] [Indexed: 12/12/2022] Open
Abstract
The main role of mitochondria, as pivotal organelles for cellular metabolism, is the production of energy (ATP) through an oxidative phosphorylation system. During this process, the electron transport chain creates a proton gradient that drives the synthesis of ATP. One of the main features of tumoral cells is their altered metabolism, providing alternative routes to enhance proliferation and survival. Hence, it is of utmost importance to understand the relationship between mitochondrial pH, tumoral metabolism, and cancer. In this manuscript, we develop a highly specific nanosensor to accurately measure the intramitochondrial pH using fluorescence lifetime imaging microscopy (FLIM). Importantly, we have applied this nanosensor to establish differences that may be hallmarks of different metabolic pathways in breast cancer cell models, leading to the characterization of different metabophenotypes.
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Affiliation(s)
- Consuelo Ripoll
- Departamento de Fisicoquimica, Facultad de Farmacia, Unidad de Excelencia en Quimica Aplicada a Biomedicina y Medioambiente (UEQ), Universidad de Granada, Campus Cartuja, 18071 Granada, Spain; (C.R.); (M.J.R.-R.)
| | - Mar Roldan
- GENYO, Pfizer-Universidad de Granada-Junta de Andalucia Centre for Genomics and Oncological Research, Avda Ilustracion 114, PTS, 18016 Granada, Spain; (M.R.); (J.J.D.-M.); (M.M)
| | - Rafael Contreras-Montoya
- Departamento de Quimica Organica, Facultad de Ciencias, Unidad de Excelencia en Quimica Aplicada a Biomedicina y Medioambiente (UEQ), Universidad de Granada, Campus Fuentenueva, 18071 Granada, Spain;
| | - Juan J. Diaz-Mochon
- GENYO, Pfizer-Universidad de Granada-Junta de Andalucia Centre for Genomics and Oncological Research, Avda Ilustracion 114, PTS, 18016 Granada, Spain; (M.R.); (J.J.D.-M.); (M.M)
- Departamento de Quimica Farmaceutica y Organica, Facultad de Farmacia, Unidad de Excelencia en Quimica Aplicada a Biomedicina y Medioambiente (UEQ), Universidad de Granada, Campus Cartuja, 18071 Granada, Spain
| | - Miguel Martin
- GENYO, Pfizer-Universidad de Granada-Junta de Andalucia Centre for Genomics and Oncological Research, Avda Ilustracion 114, PTS, 18016 Granada, Spain; (M.R.); (J.J.D.-M.); (M.M)
- Departamento de Bioquimica y Biologia Celular I, Facultad de Ciencias, Universidad de Granada, Campus Fuentenueva, 18071 Granada, Spain
| | - Maria J. Ruedas-Rama
- Departamento de Fisicoquimica, Facultad de Farmacia, Unidad de Excelencia en Quimica Aplicada a Biomedicina y Medioambiente (UEQ), Universidad de Granada, Campus Cartuja, 18071 Granada, Spain; (C.R.); (M.J.R.-R.)
| | - Angel Orte
- Departamento de Fisicoquimica, Facultad de Farmacia, Unidad de Excelencia en Quimica Aplicada a Biomedicina y Medioambiente (UEQ), Universidad de Granada, Campus Cartuja, 18071 Granada, Spain; (C.R.); (M.J.R.-R.)
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Méndez‐Ardoy A, Reina JJ, Montenegro J. Synthesis and Supramolecular Functional Assemblies of Ratiometric pH Probes. Chemistry 2020; 26:7516-7536. [DOI: 10.1002/chem.201904834] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 12/20/2019] [Indexed: 01/28/2023]
Affiliation(s)
- Alejandro Méndez‐Ardoy
- Centro Singular de Investigación en Química Biolóxica e, Materiais Moleculares (CIQUS)Departamento de Química OrgánicaUniversidade de Santiago de Compostela 15782 Santiago de Compostela Spain
| | - Jose J. Reina
- Centro Singular de Investigación en Química Biolóxica e, Materiais Moleculares (CIQUS)Departamento de Química OrgánicaUniversidade de Santiago de Compostela 15782 Santiago de Compostela Spain
| | - Javier Montenegro
- Centro Singular de Investigación en Química Biolóxica e, Materiais Moleculares (CIQUS)Departamento de Química OrgánicaUniversidade de Santiago de Compostela 15782 Santiago de Compostela Spain
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77
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Huang M, Liang X, Zhang Z, Wang J, Fei Y, Ma J, Qu S, Mi L. Carbon Dots for Intracellular pH Sensing with Fluorescence Lifetime Imaging Microscopy. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E604. [PMID: 32218205 PMCID: PMC7221822 DOI: 10.3390/nano10040604] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 03/11/2020] [Accepted: 03/24/2020] [Indexed: 12/11/2022]
Abstract
The monitoring of intracellular pH is of great importance for understanding intracellular trafficking and functions. It has various limitations for biosensing based on the fluorescence intensity or spectra study. In this research, pH-sensitive carbon dots (CDs) were employed for intracellular pH sensing with fluorescence lifetime imaging microscopy (FLIM) for the first time. FLIM is a highly sensitive method that is used to detect a microenvironment and it can overcome the limitations of biosensing methods based on fluorescence intensity. The different groups on the CDs surfaces changing with pH environments led to different fluorescence lifetime values. The CDs aqueous solution had a gradual change from 1.6 ns to 3.7 ns in the fluorescence lifetime with a pH range of 2.6-8.6. Similar fluorescence lifetime changes were found in pH buffer-treated living cells. The detection of lysosomes, cytoplasm, and nuclei in living cells was achieved by measuring the fluorescence lifetime of CDs. In particular, a phasor FLIM analysis was used to improve the pH imaging. Moreover, the effects of the coenzymes, amino acids, and proteins on the fluorescence lifetime of CDs were examined in order to mimic the complex microenvironment inside the cells.
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Affiliation(s)
- Maojia Huang
- Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing, Green Photoelectron Platform, Fudan University, Shanghai 200433, China; (M.H.); (X.L.); (Z.Z.); (Y.F.)
| | - Xinyue Liang
- Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing, Green Photoelectron Platform, Fudan University, Shanghai 200433, China; (M.H.); (X.L.); (Z.Z.); (Y.F.)
| | - Zixiao Zhang
- Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing, Green Photoelectron Platform, Fudan University, Shanghai 200433, China; (M.H.); (X.L.); (Z.Z.); (Y.F.)
| | - Jing Wang
- State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China;
| | - Yiyan Fei
- Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing, Green Photoelectron Platform, Fudan University, Shanghai 200433, China; (M.H.); (X.L.); (Z.Z.); (Y.F.)
| | - Jiong Ma
- Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing, Green Photoelectron Platform, Fudan University, Shanghai 200433, China; (M.H.); (X.L.); (Z.Z.); (Y.F.)
- Institute of Biomedical Engineering and Technology, Academy for Engineer and Technology, Fudan University, Shanghai 200433, China
- The Multiscale Research Institute of Complex Systems (MRICS), School of Life Sciences, Fudan University, Shanghai 200433, China
| | - Songnan Qu
- Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering, University of Macau, Avenida da Universidade, Taipa, Macau 999078, China
| | - Lan Mi
- Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing, Green Photoelectron Platform, Fudan University, Shanghai 200433, China; (M.H.); (X.L.); (Z.Z.); (Y.F.)
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78
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Gerndt S, Chen CC, Chao YK, Yuan Y, Burgstaller S, Scotto Rosato A, Krogsaeter E, Urban N, Jacob K, Nguyen ONP, Miller MT, Keller M, Vollmar AM, Gudermann T, Zierler S, Schredelseker J, Schaefer M, Biel M, Malli R, Wahl-Schott C, Bracher F, Patel S, Grimm C. Agonist-mediated switching of ion selectivity in TPC2 differentially promotes lysosomal function. eLife 2020; 9:54712. [PMID: 32167471 PMCID: PMC7108868 DOI: 10.7554/elife.54712] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Accepted: 03/12/2020] [Indexed: 12/16/2022] Open
Abstract
Ion selectivity is a defining feature of a given ion channel and is considered immutable. Here we show that ion selectivity of the lysosomal ion channel TPC2, which is hotly debated (Calcraft et al., 2009; Guo et al., 2017; Jha et al., 2014; Ruas et al., 2015; Wang et al., 2012), depends on the activating ligand. A high-throughput screen identified two structurally distinct TPC2 agonists. One of these evoked robust Ca2+-signals and non-selective cation currents, the other weaker Ca2+-signals and Na+-selective currents. These properties were mirrored by the Ca2+-mobilizing messenger, NAADP and the phosphoinositide, PI(3,5)P2, respectively. Agonist action was differentially inhibited by mutation of a single TPC2 residue and coupled to opposing changes in lysosomal pH and exocytosis. Our findings resolve conflicting reports on the permeability and gating properties of TPC2 and they establish a new paradigm whereby a single ion channel mediates distinct, functionally-relevant ionic signatures on demand.
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Affiliation(s)
- Susanne Gerndt
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany.,Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Cheng-Chang Chen
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany
| | - Yu-Kai Chao
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Yu Yuan
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Sandra Burgstaller
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Anna Scotto Rosato
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Einar Krogsaeter
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Nicole Urban
- Rudolf-Boehm-Institute for Pharmacology and Toxicology, Universität Leipzig, Leipzig, Germany
| | - Katharina Jacob
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Ong Nam Phuong Nguyen
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany
| | - Meghan T Miller
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany.,Pharma Research and Early Development (pRED), Roche Innovation Center Basel, F. Hoffmann-La Roche, Basel, Switzerland
| | - Marco Keller
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany
| | - Angelika M Vollmar
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Susanna Zierler
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Johann Schredelseker
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany.,Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
| | - Michael Schaefer
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany.,Rudolf-Boehm-Institute for Pharmacology and Toxicology, Universität Leipzig, Leipzig, Germany
| | - Martin Biel
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany
| | - Roland Malli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | | | - Franz Bracher
- Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität, Munich, Germany
| | - Sandip Patel
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Christian Grimm
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, Ludwig-Maximilians-Universität, Munich, Germany
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79
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Ehtesabi H, Hallaji Z, Najafi Nobar S, Bagheri Z. Carbon dots with pH-responsive fluorescence: a review on synthesis and cell biological applications. Mikrochim Acta 2020; 187:150. [PMID: 31989317 DOI: 10.1007/s00604-019-4091-4] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 12/17/2019] [Indexed: 12/24/2022]
Abstract
This review summarizes state of the art synthesis and applications of carbon dots (CDs) with pH-responsive fluorescence. Following an introduction, the first section covers methods for the preparation of pH-responsive CDs, with subsections on general methods for preparing CDs (by hydrothermal, solvothermal, electrochemical, microwave, laser ablation, pyrolysis or chemical oxidation polymerization methods), and on precursors for synthesis. This is followed by a section on the mechanisms of pH-responsivity (by creating new functional groups, change of energy levels, protonation and deprotonation, aggregation, or by introduction shells). Several Tables are presented that give an overview of the wealth of methods and materials. A final section covers applications of carbon dots (CDs) with pH-responsive fluorescence for sensing, drug delivery, and imaging. The conclusion summarizes the current status, addresses challenges, and gives an outlook on potential future trends. Graphical abstract The synthesis and biological applications of carbon dots(CDs) with pH-responsive fluorescence are summarized. Precursors and methods for preparation of pH-responsive CDs, mechanisms of pH-responsivity, and biological applications of CDs with pH-responsive fluorescence for sensing, drug delivery, and imaging are discussed.
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Affiliation(s)
- Hamide Ehtesabi
- Faculty of Life Sciences and Biotechnology, Shahid Beheshti University G.C, Tehran, 19839-69411, Iran
| | - Zahra Hallaji
- Faculty of Biological Sciences, Tarbiat Modares University, Tehran, 14117-13116, Iran
| | - Shima Najafi Nobar
- Faculty of Mechanical Engineering, K. N. Toosi University of Technology, Tehran, 19697-64499, Iran
| | - Zeinab Bagheri
- Faculty of Life Sciences and Biotechnology, Shahid Beheshti University G.C, Tehran, 19839-69411, Iran.
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80
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81
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Chakraborty S, Nandi S, Bhattacharyya K, Mukherjee S. Time Evolution of Local pH Around a Photo-Acid in Water and a Polymer Hydrogel: Time Resolved Fluorescence Spectroscopy of Pyranine. Chemphyschem 2019; 20:3221-3227. [PMID: 31596029 DOI: 10.1002/cphc.201900845] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 09/19/2019] [Indexed: 12/31/2022]
Abstract
In this work, we propose a new analysis of the time resolved emission spectra of a photo-acid, HA, pyranine (8-hydroxypyrene-1,3,6-trisulphonic acid, HPTS) based on time resolved area normalized emission spectra (TRANES). Presence of an isoemissive point in TRANES confirms the presence of two emissive species (HA and A- ) inside the system in bulk water and inside a co-polymer hydrogel [F127, (PEO)100 -(PPO)70 -(PEO)100 ]. We show that following electronic excitation, the local pH around HPTS, is much lower than the bulk pH presumably because of ejection of proton from the photo-acid in the excited state. With increase in time, the local pH increases and reaches the bulk value. We further, demonstrate that the excited state pKa of HPTS may be estimated from the emission intensities of HA and A- at long time. The time constant for time evolution of pH is ∼630 ps in water, ∼1300 ps in F127 gel and ∼4700 ps in CTAB micelle. The location and local viscosity sensed by the probe is ascertained using fluorescence correlation spectroscopy (FCS) and fluorescence anisotropy decay. The different values of the local viscosity reported by these two methods are reconciled.
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Affiliation(s)
- Subhajit Chakraborty
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhopal, 462 066, Madhya Pradesh, India
| | - Somen Nandi
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhopal, 462 066, Madhya Pradesh, India
| | - Kankan Bhattacharyya
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhopal, 462 066, Madhya Pradesh, India
| | - Saptarshi Mukherjee
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhopal, 462 066, Madhya Pradesh, India
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82
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Waldeck-Weiermair M, Gottschalk B, Madreiter-Sokolowski CT, Ramadani-Muja J, Ziomek G, Klec C, Burgstaller S, Bischof H, Depaoli MR, Eroglu E, Malli R, Graier WF. Development and Application of Sub-Mitochondrial Targeted Ca 2 + Biosensors. Front Cell Neurosci 2019; 13:449. [PMID: 31636543 PMCID: PMC6788349 DOI: 10.3389/fncel.2019.00449] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 09/20/2019] [Indexed: 12/20/2022] Open
Abstract
Mitochondrial Ca2+ uptake into the mitochondrial matrix is a well-established mechanism. However, the sub-organellar Ca2+ kinetics remain elusive. In the present work we identified novel site-specific targeting sequences for the intermembrane space (IMS) and the cristae lumen (CL). We used these novel targeting peptides to develop green- and red- Ca2+ biosensors targeted to the IMS and to the CL. Based on their distinctive spectral properties, and comparable sensitivities these novel constructs were suitable to visualize Ca2+-levels in various (sub) compartments in a multi-chromatic manner. Functional studies that applied these new biosensors revealed that knockdown of MCU and EMRE yielded elevated Ca2+ levels inside the CL but not the IMS in response to IP3-generating agonists. Knockdown of VDAC1, however, strongly impeded the transfer of Ca2+ through the OMM while the cytosolic Ca2+ signal remained unchanged. The novel sub-mitochondrially targeted Ca2+ biosensors proved to be suitable for Ca2+ imaging with high spatial and temporal resolution in a multi-chromatic manner allowing simultaneous measurements. These informative biosensors will facilitate efforts to dissect the complex sub-mitochondrial Ca2+ signaling under (patho)physiological conditions.
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Affiliation(s)
- Markus Waldeck-Weiermair
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Benjamin Gottschalk
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Corina T. Madreiter-Sokolowski
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
- Energy Metabolism Laboratory, Institute of Translational Medicine, D-HEST, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
| | - Jeta Ramadani-Muja
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Gabriela Ziomek
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Christiane Klec
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
- Department of Internal Medicine, Division of Oncology, Medical University of Graz, Graz, Austria
| | - Sandra Burgstaller
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Helmut Bischof
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Maria R. Depaoli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
| | - Emrah Eroglu
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Roland Malli
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Wolfgang F. Graier
- Molecular Biology and Biochemistry, Gottfried Schatz Research Center, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
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83
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Wang Y, Zhang N, Lu S, Wang J, Bing T, Liu X, Chen C, Shangguan D. Dual-Monitoring Glycosylation and Local pH in Live Cells by Metabolic Oligosaccharide Engineering with a Ratiometric Fluorescent Tag. Anal Chem 2019; 91:13720-13728. [DOI: 10.1021/acs.analchem.9b03047] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Yan Wang
- College of Chemistry, Xiangtan University, Xiangtan 411105, China
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Nan Zhang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shanshan Lu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Junyan Wang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tao Bing
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiangjun Liu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chunyan Chen
- College of Chemistry, Xiangtan University, Xiangtan 411105, China
| | - Dihua Shangguan
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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84
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Live cell imaging of signaling and metabolic activities. Pharmacol Ther 2019; 202:98-119. [DOI: 10.1016/j.pharmthera.2019.06.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 05/31/2019] [Indexed: 12/15/2022]
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85
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Bischof H, Burgstaller S, Vujic N, Madl T, Kratky D, Graier WF, Malli R. Purification and Application of Genetically Encoded Potassium Ion Indicators for Quantification of Potassium Ion Concentrations within Biological Samples. CURRENT PROTOCOLS IN CHEMICAL BIOLOGY 2019; 11:e71. [PMID: 31483097 PMCID: PMC6927797 DOI: 10.1002/cpch.71] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Vital cells maintain a steep potassium ion (K+ ) gradient across the plasma membrane. Intracellular potassium ion concentrations ([K+ ]) and especially the [K+ ] within the extracellular matrix are strictly regulated, the latter within a narrow range of ∼3.5 to 5.0 mM. Alterations of the extracellular K+ homeostasis are associated with severe pathological alterations and systemic diseases including hypo- or hypertension, heart rate alterations, heart failure, neuronal damage or abnormal skeleton muscle function. In higher eukaryotic organisms, the maintenance of the extracellular [K+ ] is mainly achieved by the kidney, responsible for K+ excretion and reabsorption. Thus, renal dysfunctions are typically associated with alterations in serum- or plasma [K+ ]. Generally, [K+ ] quantifications within bodily fluids are performed using ion selective electrodes. However, tracking such alterations in experimental models such as mice features several difficulties, mainly due to the small blood volume of these animals, hampering the repetitive collection of sample volumes required for measurements using ion selective electrodes. We have recently developed highly sensitive, genetically encoded potassium ion indicators, the GEPIIs, applicable for in vitro determinations of [K+ ]. In addition to the determination of [K+ ] within bodily fluids, GEPIIs proved suitable for the real-time visualization of cell viability over time and the exact determination of the number of dead cells. © 2019 The Authors.
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Affiliation(s)
- H Bischof
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - S Burgstaller
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - N Vujic
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - T Madl
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - D Kratky
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - W F Graier
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - R Malli
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
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86
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Live-Cell Imaging of Physiologically Relevant Metal Ions Using Genetically Encoded FRET-Based Probes. Cells 2019; 8:cells8050492. [PMID: 31121936 PMCID: PMC6562680 DOI: 10.3390/cells8050492] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 05/17/2019] [Accepted: 05/21/2019] [Indexed: 01/02/2023] Open
Abstract
Essential biochemical reactions and processes within living organisms are coupled to subcellular fluctuations of metal ions. Disturbances in cellular metal ion homeostasis are frequently associated with pathological alterations, including neurotoxicity causing neurodegeneration, as well as metabolic disorders or cancer. Considering these important aspects of the cellular metal ion homeostasis in health and disease, measurements of subcellular ion signals are of broad scientific interest. The investigation of the cellular ion homeostasis using classical biochemical methods is quite difficult, often even not feasible or requires large cell numbers. Here, we report of genetically encoded fluorescent probes that enable the visualization of metal ion dynamics within individual living cells and their organelles with high temporal and spatial resolution. Generally, these probes consist of specific ion binding domains fused to fluorescent protein(s), altering their fluorescent properties upon ion binding. This review focuses on the functionality and potential of these genetically encoded fluorescent tools which enable monitoring (sub)cellular concentrations of alkali metals such as K+, alkaline earth metals including Mg2+ and Ca2+, and transition metals including Cu+/Cu2+ and Zn2+. Moreover, we discuss possible approaches for the development and application of novel metal ion biosensors for Fe2+/Fe3+, Mn2+ and Na+.
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