1
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Chacko AN, Miller ADC, Dhanabalan KM, Mukherjee A. Exploring the potential of water channels for developing genetically encoded reporters and biosensors for diffusion-weighted MRI. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2024; 365:107743. [PMID: 39053029 DOI: 10.1016/j.jmr.2024.107743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 07/02/2024] [Accepted: 07/17/2024] [Indexed: 07/27/2024]
Abstract
Genetically encoded reporters for magnetic resonance imaging (MRI) offer a valuable technology for making molecular-scale measurements of biological processes within living organisms with high anatomical resolution and whole-organ coverage without relying on ionizing radiation. However, most MRI reporters rely on synthetic contrast agents, typically paramagnetic metals and metal complexes, which often need to be supplemented exogenously to create optimal contrast. To eliminate the need for synthetic contrast agents, we previously introduced aquaporin-1, a mammalian water channel, as a new reporter gene for the fully autonomous detection of genetically labeled cells using diffusion-weighted MRI. In this study, we aimed to expand the toolbox of diffusion-based genetic reporters by modulating aquaporin membrane trafficking and harnessing the evolutionary diversity of water channels across species. We identified a number of new water channels that functioned as diffusion-weighted reporter genes. In addition, we show that loss-of-function variants of yeast and human aquaporins can be leveraged to design first-in-class diffusion-based sensors for detecting the activity of a model protease within living cells.
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Affiliation(s)
- Asish N Chacko
- Department of Chemistry, University of California, Santa Barbara, CA 93106-5080, USA
| | - Austin D C Miller
- Biomolecular Science and Engineering Graduate Program, University of California, Santa Barbara, CA 93106-5080, USA
| | - Kaamini M Dhanabalan
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106-5080, USA
| | - Arnab Mukherjee
- Department of Chemistry, University of California, Santa Barbara, CA 93106-5080, USA; Biomolecular Science and Engineering Graduate Program, University of California, Santa Barbara, CA 93106-5080, USA; Department of Chemical Engineering, University of California, Santa Barbara, CA 93106-5080, USA; Department of Bioengineering, University of California, Santa Barbara, CA 93106-5080, USA.
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2
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Rallapalli H, McCall EC, Koretsky AP. Genetic control of MRI contrast using the manganese transporter Zip14. Magn Reson Med 2024; 92:820-835. [PMID: 38573932 PMCID: PMC11142883 DOI: 10.1002/mrm.29993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 11/15/2023] [Accepted: 12/12/2023] [Indexed: 04/06/2024]
Abstract
PURPOSE Gene-expression reporter systems, such as green fluorescent protein, have been instrumental to understanding biological processes in living organisms at organ system, tissue, cell, and molecular scales. More than 30 years of work on developing MRI-visible gene-expression reporter systems has resulted in a variety of clever application-specific methods. However, these techniques have not yet been widely adopted, so a general-purpose expression reporter is still required. Here, we demonstrate that the manganese ion transporter Zip14 is an in vivo MRI-visible, flexible, and robust gene-expression reporter to meet this need. METHODS Plasmid constructs consisting of a cell type-specific promoter, gene coding for human Zip14, and a histology-visible tag were packaged into adeno-associated viruses. These viruses were intracranially injected into the mouse brain. Serial in vivo MRI was performed using a vendor-supplied 3D-MPRAGE sequence. No additional contrast agents were administered. Animals were sacrificed after the last imaging timepoint for immunohistological validation. RESULTS Neuron-specific overexpression of Zip14 produced substantial and long-lasting changes in MRI contrast. Using appropriate viruses enabled both anterograde and retrograde neural tracing. Expression of Zip14 in astrocytes also enabled MRI of glia populations in the living mammalian brain. CONCLUSIONS The flexibility of this system as an MRI-visible gene-expression reporter will enable many applications of serial, high-resolution imaging of gene expression for basic science and therapy development.
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Affiliation(s)
- Harikrishna Rallapalli
- Section on Plasticity and Imaging of the Nervous System, NINDS/NIH, Bethesda, Maryland, USA
| | - Eleanor C McCall
- Section on Plasticity and Imaging of the Nervous System, NINDS/NIH, Bethesda, Maryland, USA
| | - Alan P Koretsky
- Section on Plasticity and Imaging of the Nervous System, NINDS/NIH, Bethesda, Maryland, USA
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3
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Huang Y, Chen X, Zhu Z, Mukherjee A. A Dual-Gene Reporter-Amplifier Architecture for Enhancing the Sensitivity of Molecular MRI by Water Exchange. Chembiochem 2024; 25:e202400087. [PMID: 38439618 DOI: 10.1002/cbic.202400087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 03/04/2024] [Accepted: 03/05/2024] [Indexed: 03/06/2024]
Abstract
The development of genetic reporters for magnetic resonance imaging (MRI) is essential for investigating biological functions in vivo. However, current MRI reporters have low sensitivity, making it challenging to create significant contrast against the tissue background, especially when only a small fraction of cells express the reporter. To overcome this limitation, we developed an approach for amplifying the sensitivity of molecular MRI by combining a chemogenetic contrast mechanism with a biophysical approach to increase water diffusion through the co-expression of a dual-gene construct comprising an organic anion transporting polypeptide, Oatp1b3, and a water channel, Aqp1. We first show that the expression of Aqp1 amplifies MRI contrast in cultured cells engineered to express Oatp1b3. We demonstrate that the contrast amplification is caused by Aqp1-driven increase in water exchange, which provides the gadolinium ions internalized by Oatp1b3-expressing cells with access to a larger water pool compared with exchange-limited conditions. We further show that our methodology allows cells to be detected using approximately 10-fold lower concentrations of gadolinium than that in the Aqp1-free scenario. Finally, we show that our approach enables the imaging of mixed-cell cultures containing a low fraction of Oatp1b3-labeled cells that are undetectable on the basis of Oatp1b3 expression alone.
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Affiliation(s)
- Yimeng Huang
- Department of Chemistry, University of California, Santa Barbara, CA 93106-5080
| | - Xinyue Chen
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106-5080
| | - Ziyue Zhu
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106-5080
| | - Arnab Mukherjee
- Department of Chemistry, University of California, Santa Barbara, CA 93106-5080
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106-5080
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106-5080
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4
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Miller ADC, Chowdhury SP, Hanson HW, Linderman SK, Ghasemi HI, Miller WD, Morrissey MA, Richardson CD, Gardner BM, Mukherjee A. Engineering water exchange is a safe and effective method for magnetic resonance imaging in diverse cell types. J Biol Eng 2024; 18:30. [PMID: 38649904 PMCID: PMC11035135 DOI: 10.1186/s13036-024-00424-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 04/08/2024] [Indexed: 04/25/2024] Open
Abstract
Aquaporin-1 (Aqp1), a water channel, has garnered significant interest for cell-based medicine and in vivo synthetic biology due to its ability to be genetically encoded to produce magnetic resonance signals by increasing the rate of water diffusion in cells. However, concerns regarding the effects of Aqp1 overexpression and increased membrane diffusivity on cell physiology have limited its widespread use as a deep-tissue reporter. In this study, we present evidence that Aqp1 generates strong diffusion-based magnetic resonance signals without adversely affecting cell viability or morphology in diverse cell lines derived from mice and humans. Our findings indicate that Aqp1 overexpression does not induce ER stress, which is frequently associated with heterologous expression of membrane proteins. Furthermore, we observed that Aqp1 expression had no detrimental effects on native biological activities, such as phagocytosis, immune response, insulin secretion, and tumor cell migration in the analyzed cell lines. These findings should serve to alleviate any lingering safety concerns regarding the utilization of Aqp1 as a genetic reporter and should foster its broader application as a noninvasive reporter for in vivo studies.
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Affiliation(s)
- Austin D C Miller
- Biomolecular Science and Engineering Graduate Program, University of California, Santa Barbara, CA, 93106, USA
| | - Soham P Chowdhury
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, 93106, USA
| | - Hadley W Hanson
- Biomolecular Science and Engineering Graduate Program, University of California, Santa Barbara, CA, 93106, USA
| | - Sarah K Linderman
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, 93106, USA
| | - Hannah I Ghasemi
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, 93106, USA
| | - Wyatt D Miller
- Biomolecular Science and Engineering Graduate Program, University of California, Santa Barbara, CA, 93106, USA
| | - Meghan A Morrissey
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, 93106, USA
| | - Chris D Richardson
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, 93106, USA
| | - Brooke M Gardner
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA, 93106, USA
| | - Arnab Mukherjee
- Biomolecular Science and Engineering Graduate Program, University of California, Santa Barbara, CA, 93106, USA.
- Department of Chemical Engineering, University of California, Santa Barbara, CA, 93106, USA.
- Department of Bioengineering, University of California, Santa Barbara, CA, 93106, USA.
- Department of Chemistry, University of California, Santa Barbara, CA, 93106, USA.
- Neuroscience Research Institute, University of California, Santa Barbara, CA, 93106, USA.
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5
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Huang Y, Chen X, Zhu Z, Mukherjee A. A dual-gene reporter-amplifier architecture for enhancing the sensitivity of molecular MRI by water exchange. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.22.576672. [PMID: 38328134 PMCID: PMC10849537 DOI: 10.1101/2024.01.22.576672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
The development of genetic reporters for magnetic resonance imaging (MRI) is essential for investigating biological functions in intact animals. However, current MRI reporters have low sensitivity, making it challenging to create significant contrast against the tissue background, especially when only a small percentage of cells express the reporter. To overcome this limitation, we developed an approach that amplifies signals by co-expressing an MRI reporter gene, Oatp1b3, with a water channel, aquaporin-1 (Aqp1). We first show that the expression of Aqp1 amplifies the paramagnetic relaxation effect of Oatp1b3 by facilitating transmembrane water exchange. This mechanism provides Oatp1b3-expressing cells with access to a larger water pool compared with typical exchange-limited conditions. We further demonstrated that our methodology allows dual-labeled cells to be detected using approximately 10-fold lower concentrations of contrast agent than that in the Aqp1-free scenario. Finally, we show that our approach enables the imaging of mixed-cell populations containing a low fraction of Oatp1b3-labeled cells that are otherwise undetectable based on Oatp1b3 expression alone.
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Affiliation(s)
| | - Xinyue Chen
- Department of Molecular, Cellular, and Developmental Biology
| | - Ziyue Zhu
- Department of Molecular, Cellular, and Developmental Biology
| | - Arnab Mukherjee
- Department of Chemistry
- Department of Molecular, Cellular, and Developmental Biology
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6
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Chacko AN, Miller AD, Dhanabalan KM, Mukherjee A. Exploring the potential of water channels for developing MRI reporters and sensors without the need for exogenous contrast agents. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.21.576580. [PMID: 38328035 PMCID: PMC10849501 DOI: 10.1101/2024.01.21.576580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Genetically encoded reporters for magnetic resonance imaging (MRI) offer a valuable technology for making molecular-scale measurements of biological processes within living organisms with high anatomical resolution and whole-organ coverage without relying on ionizing radiation. However, most MRI reporters rely on contrast agents, typically paramagnetic metals and metal complexes, which often need to be supplemented exogenously to create optimal contrast. To eliminate the need for contrast agents, we previously introduced aquaporin-1, a mammalian water channel, as a new reporter gene for the fully autonomous detection of genetically labeled cells using diffusion-weighted MRI. In this study, we aimed to expand the toolbox of diffusion-based genetic reporters by modulating aquaporin membrane trafficking and harnessing the evolutionary diversity of water channels across species. We identified a number of new water channels that functioned as diffusion-weighted reporter genes. In addition, we show that loss-of-function variants of yeast and human aquaporins can be leveraged to design first-in-class diffusion-based sensors for detecting the activity of a model protease within living cells.
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Affiliation(s)
| | | | | | - Arnab Mukherjee
- Department of Chemistry
- Biomolecular Science and Engineering Graduate Program
- Department of Chemical Engineering
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7
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Li N, Wang P, Xie Y, Wang B, Zhu C, Xue L, Han X, Gu N, Sun J. Expression of clMagR/clCry4 protein in mBMSCs provides T 2-contrast enhancement of MRI. Acta Biomater 2023; 172:309-320. [PMID: 37778484 DOI: 10.1016/j.actbio.2023.09.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 09/16/2023] [Accepted: 09/25/2023] [Indexed: 10/03/2023]
Abstract
Here, we propose for the first time the evaluation of magnetosensitive clMagR/clCry4 as a magnetic resonance imaging (MRI) reporter gene that imparts sensitivity to endogenous contrast in eukaryotic organisms. Using a lentiviral vector, we introduced clMagR/clCry4 into C57BL/6 mice-derived bone marrow mesenchymal stem cells (mBMSCs), which could specifically bind with iron, significantly affected MRI transverse relaxation, and generated readily detectable contrast without adverse effects in vivo. Specifically, clMagR/clCry4 makes mBMSCs beneficial for enhancing the sensitivity of MRI-R2 for iron-bearing granules, in which cells recruit exogenous iron and convert these stores into an MRI-detectable contrast; this is not achievable with control cells. Additionally, Prussian blue staining was performed together with ultrathin cell slices to provide direct evidence of natural iron-bearing granules being detectable on MRI. Hence, it was inferred that the sensitivity of MRI detection should be correlated with clMagR/clCry4 and exogenous iron. Taken together, the clMagR/clCry4 has great potential as an MRI reporter gene. STATEMENT OF SIGNIFICANCE: In this study, we propose the evaluation of magnetosensitive clMagR/clCry4 as an MRI reporter gene, imparting detection sensitivity to eukaryotic mBMSCs for endogenous contrast. At this point, the clMagR and clCry4 were located within the cytoplasm and possibly influence each other. The clMagR/clCry4 makes mBMSCs beneficial for enhancing the sensitivity of MRI-R2 for iron-bearing granules, in which protein could specifically bind with iron and convert these stores into MRI-detectable contrast; this is not achieved by control cells. The viewpoint was speculated that the clMagR/clCry4 and exogenous iron were complementary to each other. Additionally, Prussian blue staining was performed together with TEM observations to provide direct evidence that the iron-bearing granules were sensitive to MRI.
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Affiliation(s)
- Nuan Li
- Jiangsu Key Laboratory of Biomaterials and Devices, School of Biological Sciences and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Peng Wang
- Jiangsu Key Laboratory of Biomaterials and Devices, School of Biological Sciences and Medical Engineering, Southeast University, Nanjing 210096, China; Department of Sports Medicine and Adult Reconstructive Surgery, the Affiliated Drum Tower Hospital of Nanjing University, Nanjing 210008, China
| | - Yuanyuan Xie
- Clinical Stem Cell Center, the Affiliated Drum Tower Hospital of Nanjing University, Nanjing 210008, China
| | - Bin Wang
- Clinical Stem Cell Center, the Affiliated Drum Tower Hospital of Nanjing University, Nanjing 210008, China
| | - Chenzhuo Zhu
- Southeast University-Monash University Joint Graduate School, Southeast University, Suzhou 215123, China
| | - Le Xue
- Jiangsu Key Laboratory of Biomaterials and Devices, School of Biological Sciences and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Xiaofeng Han
- School of Biological Sciences and Medical Engineering, Southeast University, Nanjing 210096, China
| | - Ning Gu
- Medical School, Nanjing University, Nanjing 210093, China
| | - Jianfei Sun
- Jiangsu Key Laboratory of Biomaterials and Devices, School of Biological Sciences and Medical Engineering, Southeast University, Nanjing 210096, China.
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8
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Hong S, Lee DS, Bae GW, Jeon J, Kim HK, Rhee S, Jung KO. In Vivo Stem Cell Imaging Principles and Applications. Int J Stem Cells 2023; 16:363-375. [PMID: 37643761 PMCID: PMC10686800 DOI: 10.15283/ijsc23045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 07/13/2023] [Accepted: 07/21/2023] [Indexed: 08/31/2023] Open
Abstract
Stem cells are the foundational cells for every organ and tissue in our body. Cell-based therapeutics using stem cells in regenerative medicine have received attracting attention as a possible treatment for various diseases caused by congenital defects. Stem cells such as induced pluripotent stem cells (iPSCs) as well as embryonic stem cells (ESCs), mesenchymal stem cells (MSCs), and neuroprogenitors stem cells (NSCs) have recently been studied in various ways as a cell-based therapeutic agent. When various stem cells are transplanted into a living body, they can differentiate and perform complex functions. For stem cell transplantation, it is essential to determine the suitability of the stem cell-based treatment by evaluating the origin of stem, the route of administration, in vivo bio-distribution, transplanted cell survival, function, and mobility. Currently, these various stem cells are being imaged in vivo through various molecular imaging methods. Various imaging modalities such as optical imaging, magnetic resonance imaging (MRI), ultrasound (US), positron emission tomography (PET), and single-photon emission computed tomography (SPECT) have been introduced for the application of various stem cell imaging. In this review, we discuss the principles and recent advances of in vivo molecular imaging for application of stem cell research.
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Affiliation(s)
- Seongje Hong
- Department of Anatomy, College of Medicine, Chung-Ang University, Seoul, Korea
| | - Dong-Sung Lee
- Department of Life Sciences, University of Seoul, Seoul, Korea
| | - Geun-Woo Bae
- Department of Anatomy, College of Medicine, Chung-Ang University, Seoul, Korea
| | - Juhyeong Jeon
- Department of Anatomy, College of Medicine, Chung-Ang University, Seoul, Korea
| | - Hak Kyun Kim
- Department of Life Science, Chung-Ang University, Seoul, Korea
| | - Siyeon Rhee
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Kyung Oh Jung
- Department of Anatomy, College of Medicine, Chung-Ang University, Seoul, Korea
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Miller ADC, Chowdhury SP, Hanson HW, Linderman SK, Ghasemi HI, Miller WD, Morrissey MA, Richardson CD, Gardner BM, Mukherjee A. Engineering water exchange is a safe and effective method for magnetic resonance imaging in diverse cell types. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.07.566095. [PMID: 37986852 PMCID: PMC10659288 DOI: 10.1101/2023.11.07.566095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Aquaporin-1 (Aqp1), a water channel, has garnered significant interest for cell-based medicine and in vivo synthetic biology due to its ability to be genetically encoded to produce magnetic resonance signals by increasing the rate of water diffusion in cells. However, concerns regarding the effects of Aqp1 overexpression and increased membrane diffusivity on cell physiology have limited its widespread use as a deep-tissue reporter. In this study, we present evidence that Aqp1 generates strong diffusion-based magnetic resonance signals without adversely affecting cell viability or morphology in diverse cell lines derived from mice and humans. Our findings indicate that Aqp1 overexpression does not induce ER stress, which is frequently associated with heterologous expression of membrane proteins. Furthermore, we observed that Aqp1 expression had no detrimental effects on native biological activities, such as phagocytosis, immune response, insulin secretion, and tumor cell migration in the analyzed cell lines. These findings should serve to alleviate any lingering safety concerns regarding the utilization of Aqp1 as a genetic reporter and should foster its broader application as a noninvasive reporter for in vivo studies.
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Affiliation(s)
- Austin D C Miller
- Biomolecular Science and Engineering Graduate Program, University of California, Santa Barbara, CA 93106, USA
| | - Soham P Chowdhury
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Hadley W Hanson
- Biomolecular Science and Engineering Graduate Program, University of California, Santa Barbara, CA 93106, USA
| | - Sarah K Linderman
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Hannah I Ghasemi
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Wyatt D Miller
- Biomolecular Science and Engineering Graduate Program, University of California, Santa Barbara, CA 93106, USA
| | - Meghan A Morrissey
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Chris D Richardson
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Brooke M Gardner
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Arnab Mukherjee
- Biomolecular Science and Engineering Graduate Program, University of California, Santa Barbara, CA 93106, USA
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA
- Department of Bioengineering, University of California, Santa Barbara, CA 93106, USA
- Department of Chemistry, University of California, Santa Barbara, CA 93106, USA
- Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA
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10
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Fillion AJ, Bricco AR, Lee HD, Korenchan D, Farrar CT, Gilad AA. Development of a synthetic biosensor for chemical exchange MRI utilizing in silico optimized peptides. NMR IN BIOMEDICINE 2023; 36:e5007. [PMID: 37469121 PMCID: PMC11075521 DOI: 10.1002/nbm.5007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 06/26/2023] [Accepted: 06/28/2023] [Indexed: 07/21/2023]
Abstract
Chemical exchange saturation transfer (CEST) MRI has been identified as a novel alternative to classical diagnostic imaging. Over the last several decades, many studies have been conducted to determine possible CEST agents, such as endogenously expressed compounds or proteins, that can be utilized to produce contrast with minimally invasive procedures and reduced or non-existent levels of toxicity. In recent years there has been an increased interest in the generation of genetically engineered CEST contrast agents, typically based on existing proteins with CEST contrast or modified to produce CEST contrast. We have developed an in silico method for the evolution of peptide sequences to optimize CEST contrast and showed that these peptides could be combined to create de novo biosensors for CEST MRI. A single protein, superCESTide, was designed to be 198 amino acids. SuperCESTide was expressed in E. coli and purified with size exclusion chromatography. The magnetic transfer ratio asymmetry generated by superCESTide was comparable to levels seen in previous CEST reporters, such as protamine sulfate (salmon protamine) and human protamine. These data show that novel peptides with sequences optimized in silico for CEST contrast that utilize a more comprehensive range of amino acids can still produce contrast when assembled into protein units expressed in complex living environments.
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Affiliation(s)
- Adam J. Fillion
- Department of Chemical Engineering, Michigan State University, East Lansing, Michigan, USA
| | - Alexander R. Bricco
- Department of Biomedical Engineering, Michigan State University, East Lansing, Michigan, USA
| | - Harvey D. Lee
- Department of Biomedical Engineering, Michigan State University, East Lansing, Michigan, USA
| | - David Korenchan
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, MA, USA
| | - Christian T. Farrar
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, MA, USA
| | - Assaf A. Gilad
- Department of Chemical Engineering, Michigan State University, East Lansing, Michigan, USA
- Department of Radiology, Michigan State University, East Lansing, Michigan, USA
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11
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Fillion AJ, Bricco AR, Lee HD, Korenchan D, Farrar CT, Gilad AA. Development of a Synthetic Biosensor for Chemical Exchange MRI Utilizing In Silico Optimized Peptides. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.08.531737. [PMID: 37016672 PMCID: PMC10071792 DOI: 10.1101/2023.03.08.531737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Chemical Exchange Saturation Transfer (CEST) magnetic resonance imaging (MRI) has been identified as a novel alternative to classical diagnostic imaging. Over the last several decades, many studies have been conducted to determine possible CEST agents, such as endogenously expressed compounds or proteins, that can be utilized to produce contrast with minimally invasive procedures and reduced or non-existent levels of toxicity. In recent years there has been an increased interest in the generation of genetically engineered CEST contrast agents, typically based on existing proteins with CEST contrast or modified to produce CEST contrast. We have developed an in-silico method for the evolution of peptide sequences to optimize CEST contrast and showed that these peptides could be combined to create de novo biosensors for CEST MRI. A single protein, superCESTide 2.0, was designed to be 198 amino acids. SuperCESTide 2.0 was expressed in E. coli and purified with size-exclusion chromatography. The magnetic transfer ratio asymmetry (MTR asym ) generated by superCESTide 2.0 was comparable to levels seen in previous CEST reporters, such as protamine sulfate (salmon protamine, SP), Poly-L-Lysine (PLL), and human protamine (hPRM1). This data shows that novel peptides with sequences optimized in silico for CEST contrast that utilizes a more comprehensive range of amino acids can still produce contrast when assembled into protein units expressed in complex living environments.
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Affiliation(s)
- Adam J. Fillion
- Department of Chemical Engineering, Michigan State University, East Lansing, Michigan, USA
| | - Alexander R. Bricco
- Department of Biomedical Engineering, Michigan State University, East Lansing, Michigan, USA
| | - Harvey D. Lee
- Department of Biomedical Engineering, Michigan State University, East Lansing, Michigan, USA
| | - David Korenchan
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, MA, USA
| | - Christian T. Farrar
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, MA, USA
| | - Assaf A. Gilad
- Department of Chemical Engineering, Michigan State University, East Lansing, Michigan, USA
- Department of Radiology, Michigan State University, East Lansing, Michigan, USA
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12
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Abstract
MRI is a widely available clinical tool for cancer diagnosis and treatment monitoring. MRI provides excellent soft tissue imaging, using a wide range of contrast mechanisms, and can non-invasively detect tissue metabolites. These approaches can be used to distinguish cancer from normal tissues, to stratify tumor aggressiveness, and to identify changes within both the tumor and its microenvironment in response to therapy. In this review, the role of MRI in immunotherapy monitoring will be discussed and how it could be utilized in the future to address some of the unique clinical questions that arise from immunotherapy. For example, MRI could play a role in identifying pseudoprogression, mixed response, T cell infiltration, cell tracking, and some of the characteristic immune-related adverse events associated with these agents. The factors to be considered when developing MRI imaging biomarkers for immunotherapy will be reviewed. Finally, the advantages and limitations of each approach will be discussed, as well as the challenges for future clinical translation into routine clinical care. Given the increasing use of immunotherapy in a wide range of cancers and the ability of MRI to detect the microstructural and functional changes associated with successful response to immunotherapy, the technique has great potential for more widespread and routine use in the future for these applications.
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Affiliation(s)
- Doreen Lau
- Centre for Immuno-Oncology, University of Oxford, Oxford, UK
| | - Pippa G Corrie
- Department of Oncology, Addenbrooke's Hospital, Cambridge, UK
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13
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Yun J, Baldini M, Chowdhury R, Mukherjee A. Designing Protein-Based Probes for Sensing Biological Analytes with Magnetic Resonance Imaging. ANALYSIS & SENSING 2022; 2:e202200019. [PMID: 37409177 PMCID: PMC10321474 DOI: 10.1002/anse.202200019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/07/2023]
Abstract
Genetically encoded sensors provide unique advantages for monitoring biological analytes with molecular and cellular-level specificity. While sensors derived from fluorescent proteins represent staple tools in biological imaging, these probes are limited to optically accessible preparations owing to physical curbs on light penetration. In contrast to optical methods, magnetic resonance imaging (MRI) may be used to noninvasively look inside intact organisms at any arbitrary depth and over large fields of view. These capabilities have spurred the development of innovative methods to connect MRI readouts with biological targets using protein-based probes that are in principle genetically encodable. Here, we highlight the state-of-the-art in MRI-based biomolecular sensors, focusing on their physical mechanisms, quantitative characteristics, and biological applications. We also describe how innovations in reporter gene technology are creating new opportunities to engineer MRI sensors that are sensitive to dilute biological targets.
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Affiliation(s)
- Jason Yun
- Department of Chemistry, University of California, Santa Barbara, CA 93106, USA
| | - Michelle Baldini
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA
| | - Rochishnu Chowdhury
- Mechanical Engineering, University of California, Santa Barbara, CA 93106, USA
| | - Arnab Mukherjee
- Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA
- Department of Chemistry, University of California, Santa Barbara, CA 93106, USA
- Biomolecular Science and Engineering, University of California, Santa Barbara, CA 93106, USA
- Neuroscience Research Institute, University of California, Santa Barbara, CA 93106, USA
- Center for BioEngineering, University of California, Santa Barbara, CA 93106, USA
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14
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Liu T, Li Z, Li X, Zhao R, Wei X, Wang Z, Xin SX. In vivo visualization of murine melanoma cells B16-derived exosomes through magnetic resonance imaging. Biochim Biophys Acta Gen Subj 2022; 1866:130062. [PMID: 34822924 DOI: 10.1016/j.bbagen.2021.130062] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 10/22/2021] [Accepted: 11/17/2021] [Indexed: 10/19/2022]
Abstract
BACKGROUND Numerous studies demonstrated that exosomes play a powerful role in mediating intercellular communication to induce a pro-tumoral environment to promote tumor progression, including pre-metastatic niche formation and metastasis. Noninvasive imaging could determine the in vivo kinetics of exosomes in real time to provide better understanding of the mechanisms of the tumor formation, progression and metastasis. Magnetic resonance imaging (MRI) is an ideal technique which provides excellent anatomical resolution, intrinsic soft tissue contrast, unlimited penetration depth and no radiation exposure. METHODS A fusion protein composed of ferritin heavy chain (FTH1) and lactadherin was designed for visualizing exosomes through MRI. FTH1 was served as MRI reporter protein and lactadherin is a membrane-associated protein that is distributed on exosome surface. The characterizations of labeled exosomes were validated through transmission electron microscopy, western blot, nanoparticle tracking analysis and finally visualized in vitro and in vivo through MRI. RESULTS MR imaging showed that the labeled exosomes are able to be visualized in vitro and in vivo. Verification of the characterizations of exosomes observed no significant difference between labeled and unlabeled exosomes. CONCLUSION The proposed FTH1 labeling method was useful for visualizing exosomes through MRI. GENERAL SIGNIFICANCE The present study first reported a novel self-label method for imaging labeled exosomes of tumor cells in vivo through MR with cell endogenous MRI reporter protein. It may be further used as a tool to enhance understanding the role of exosomes in various pathophysiological conditions.
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Affiliation(s)
- Tianqi Liu
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, Guangdong, China
| | - Zhenlin Li
- Department of Histology and Embryology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, Guangdong, China
| | - Xiaodong Li
- School of Medicine, South China University of Technology, Guangzhou 510006, Guangdong, China
| | - Ruiting Zhao
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, Guangdong, China
| | - Xinhua Wei
- Department of Radiology, Guangzhou First People's Hospital, South China University of Technology, Guangzhou 510180, Guangdong, China
| | - Zixin Wang
- School of Electronics and Information Technology, Sun Yat-Sen University, Xingang Xi Road 135, Guangzhou 510275, Guangdong, China
| | - Sherman Xuegang Xin
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, Guangdong, China; School of Medicine, South China University of Technology, Guangzhou 510006, Guangdong, China.
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15
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Computationally designed dual-color MRI reporters for noninvasive imaging of transgene expression. Nat Biotechnol 2022; 40:1143-1149. [PMID: 35102291 DOI: 10.1038/s41587-021-01162-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 11/12/2021] [Indexed: 12/13/2022]
Abstract
Imaging of gene-expression patterns in live animals is difficult to achieve with fluorescent proteins because tissues are opaque to visible light. Imaging of transgene expression with magnetic resonance imaging (MRI), which penetrates to deep tissues, has been limited by single reporter visualization capabilities. Moreover, the low-throughput capacity of MRI limits large-scale mutagenesis strategies to improve existing reporters. Here we develop an MRI system, called GeneREFORM, comprising orthogonal reporters for two-color imaging of transgene expression in deep tissues. Starting from two promiscuous deoxyribonucleoside kinases, we computationally designed highly active, orthogonal enzymes ('reporter genes') that specifically phosphorylate two MRI-detectable synthetic deoxyribonucleosides ('reporter probes'). Systemically administered reporter probes exclusively accumulate in cells expressing the designed reporter genes, and their distribution is displayed as pseudo-colored MRI maps based on dynamic proton exchange for noninvasive visualization of transgene expression. We envision that future extensions of GeneREFORM will pave the way to multiplexed deep-tissue mapping of gene expression in live animals.
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16
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Fan K, Lu C, Shu G, Lv XL, Qiao E, Zhang N, Chen M, Song J, Wu F, Zhao Z, Xu X, Xu M, Chen C, Yang W, Sun J, Du Y, Ji J. Sialic acid-engineered mesoporous polydopamine dual loaded with ferritin gene and SPIO for achieving endogenous and exogenous synergistic T2-weighted magnetic resonance imaging of HCC. J Nanobiotechnology 2021; 19:76. [PMID: 33731140 PMCID: PMC7968241 DOI: 10.1186/s12951-021-00821-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 03/05/2021] [Indexed: 12/20/2022] Open
Abstract
Background Hepatocellular carcinoma (HCC) is a common malignant tumor with poor prognosis. Magnetic resonance imaging (MRI) is one of the most effective imaging methods for the early diagnosis of HCC. However, the current MR contrast agents are still facing challenges in the early diagnosis of HCC due to their relatively low sensitivity and biosafety. Thus, the development of effective MR agents is highly needed for the early diagnosis of HCC. Results Herein, we fabricated an HCC-targeted nanocomplexes containing SPIO-loaded mesoporous polydopamine (MPDA@SPIO), sialic acid (SA)-modified polyethyleneimine (SA-PEI), and alpha-fetoprotein regulated ferritin gene (AFP-Fth) which was developed for the early diagnosis of HCC. It was found that the prepared nanocomplexes (MPDA@SPIO/SA-PEI/AFP-Fth) has an excellent biocompatibility towards the liver cells. In vivo and in vivo studies revealed that the transfection of AFP-Fth gene in hepatic cells significantly upregulated the expression level of ferritin, thereby resulting in an enhanced contrast on T2-weighted images via the formed endogenous MR contrast. Conclusions The results suggested that MPDA@SPIO/SA-PEI/AFP-Fth had a superior ability to enhance the MR contrast of T2-weighted images of tumor region than the other preparations, which was due to its HCC-targeted ability and the combined T2 contrast effect of endogenous ferritin and exogenous SPIO. Our study proved that MPDA@SPIO/SA-PEI/AFP-Fth nanocomplexes could be used as an effective MR contrast agent to detect HCC in the early stage.![]() Supplementary Information The online version contains supplementary material available at 10.1186/s12951-021-00821-8.
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Affiliation(s)
- Kai Fan
- Department of Radiology, Key Laboratory of Imaging Diagnosis and Minimally Invasive Intervention Research, School of Medicine, Lishui Hospital of Zhejiang University, Lishui, 323000, Zhejiang, China.,Department of Radiology, Sir Run Shaw Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Chengying Lu
- Department of Radiology, Key Laboratory of Imaging Diagnosis and Minimally Invasive Intervention Research, School of Medicine, Lishui Hospital of Zhejiang University, Lishui, 323000, Zhejiang, China
| | - Gaofeng Shu
- Department of Radiology, Key Laboratory of Imaging Diagnosis and Minimally Invasive Intervention Research, School of Medicine, Lishui Hospital of Zhejiang University, Lishui, 323000, Zhejiang, China.,Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China
| | - Xiu-Ling Lv
- Department of Radiology, Key Laboratory of Imaging Diagnosis and Minimally Invasive Intervention Research, School of Medicine, Lishui Hospital of Zhejiang University, Lishui, 323000, Zhejiang, China
| | - Enqi Qiao
- Department of Radiology, Key Laboratory of Imaging Diagnosis and Minimally Invasive Intervention Research, School of Medicine, Lishui Hospital of Zhejiang University, Lishui, 323000, Zhejiang, China.,Department of Radiology, Sir Run Shaw Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Nannan Zhang
- Department of Radiology, Key Laboratory of Imaging Diagnosis and Minimally Invasive Intervention Research, School of Medicine, Lishui Hospital of Zhejiang University, Lishui, 323000, Zhejiang, China
| | - Minjiang Chen
- Department of Radiology, Key Laboratory of Imaging Diagnosis and Minimally Invasive Intervention Research, School of Medicine, Lishui Hospital of Zhejiang University, Lishui, 323000, Zhejiang, China.,Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China
| | - Jingjing Song
- Department of Radiology, Key Laboratory of Imaging Diagnosis and Minimally Invasive Intervention Research, School of Medicine, Lishui Hospital of Zhejiang University, Lishui, 323000, Zhejiang, China
| | - Fazong Wu
- Department of Radiology, Key Laboratory of Imaging Diagnosis and Minimally Invasive Intervention Research, School of Medicine, Lishui Hospital of Zhejiang University, Lishui, 323000, Zhejiang, China
| | - Zhongwei Zhao
- Department of Radiology, Key Laboratory of Imaging Diagnosis and Minimally Invasive Intervention Research, School of Medicine, Lishui Hospital of Zhejiang University, Lishui, 323000, Zhejiang, China
| | - Xiaoling Xu
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China
| | - Min Xu
- Department of Radiology, Key Laboratory of Imaging Diagnosis and Minimally Invasive Intervention Research, School of Medicine, Lishui Hospital of Zhejiang University, Lishui, 323000, Zhejiang, China
| | - Chunmiao Chen
- Department of Radiology, Key Laboratory of Imaging Diagnosis and Minimally Invasive Intervention Research, School of Medicine, Lishui Hospital of Zhejiang University, Lishui, 323000, Zhejiang, China
| | - Weibin Yang
- Department of Radiology, Key Laboratory of Imaging Diagnosis and Minimally Invasive Intervention Research, School of Medicine, Lishui Hospital of Zhejiang University, Lishui, 323000, Zhejiang, China
| | - Jihong Sun
- Department of Radiology, Sir Run Shaw Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, 310058, China
| | - Yongzhong Du
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China.
| | - Jiansong Ji
- Department of Radiology, Key Laboratory of Imaging Diagnosis and Minimally Invasive Intervention Research, School of Medicine, Lishui Hospital of Zhejiang University, Lishui, 323000, Zhejiang, China.
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17
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Tsintou M, Dalamagkas K, Moore TL, Rathi Y, Kubicki M, Rosene DL, Makris N. The use of hydrogel-delivered extracellular vesicles in recovery of motor function in stroke: a testable experimental hypothesis for clinical translation including behavioral and neuroimaging assessment approaches. Neural Regen Res 2021; 16:605-613. [PMID: 33063708 PMCID: PMC8067932 DOI: 10.4103/1673-5374.295269] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Neural tissue engineering, nanotechnology and neuroregeneration are diverse biomedical disciplines that have been working together in recent decades to solve the complex problems linked to central nervous system (CNS) repair. It is known that the CNS demonstrates a very limited regenerative capacity because of a microenvironment that impedes effective regenerative processes, making development of CNS therapeutics challenging. Given the high prevalence of CNS conditions such as stroke that damage the brain and place a severe burden on afflicted individuals and on society, it is of utmost significance to explore the optimum methodologies for finding treatments that could be applied to humans for restoration of function to pre-injury levels. Extracellular vesicles (EVs), also known as exosomes, when derived from mesenchymal stem cells, are one of the most promising approaches that have been attempted thus far, as EVs deliver factors that stimulate recovery by acting at the nanoscale level on intercellular communication while avoiding the risks linked to stem cell transplantation. At the same time, advances in tissue engineering and regenerative medicine have offered the potential of using hydrogels as bio-scaffolds in order to provide the stroma required for neural repair to occur, as well as the release of biomolecules facilitating or inducing the reparative processes. This review introduces a novel experimental hypothesis regarding the benefits that could be offered if EVs were to be combined with biocompatible injectable hydrogels. The rationale behind this hypothesis is presented, analyzing how a hydrogel might prolong the retention of EVs and maximize the localized benefit to the brain. This sustained delivery of EVs would be coupled with essential guidance cues and structural support from the hydrogel until neural tissue remodeling and regeneration occur. Finally, the importance of including non-human primate models in the clinical translation pipeline, as well as the added benefit of multi-modal neuroimaging analysis to establish non-invasive, in vivo, quantifiable imaging-based biomarkers for CNS repair are discussed, aiming for more effective and safe clinical translation of such regenerative therapies to humans.
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Affiliation(s)
- Magdalini Tsintou
- Department of Psychiatry and Neurology Services, Center for Neural Systems Investigations, Center for Morphometric Analysis, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital; Department of Psychiatry, Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; University College of London Division of Surgery & Interventional Science, Center for Nanotechnology & Regenerative Medicine, University College London, London, UK
| | - Kyriakos Dalamagkas
- University College of London Division of Surgery & Interventional Science, Center for Nanotechnology & Regenerative Medicine, University College London, London, UK; Department of Physical Medicine and Rehabilitation, The University of Texas Health Science Center at Houston; The Institute for Rehabilitation and Research Memorial Hermann Research Center, The Institute for Rehabilitation and Research Memorial Hermann Hospital, Houston, TX, USA
| | - Tara L Moore
- Department of Anatomy & Neurobiology, Boston University School of Medicine, Boston, MA, USA
| | - Yogesh Rathi
- Department of Psychiatry and Neurology Services, Center for Neural Systems Investigations, Center for Morphometric Analysis, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital; Department of Psychiatry, Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Marek Kubicki
- Department of Psychiatry and Neurology Services, Center for Neural Systems Investigations, Center for Morphometric Analysis, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital; Department of Psychiatry, Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Douglas L Rosene
- Department of Anatomy & Neurobiology, Boston University School of Medicine, Boston, MA, USA
| | - Nikos Makris
- Department of Psychiatry and Neurology Services, Center for Neural Systems Investigations, Center for Morphometric Analysis, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital; Department of Psychiatry, Psychiatry Neuroimaging Laboratory, Brigham and Women's Hospital, Harvard Medical School; Department of Anatomy & Neurobiology, Boston University School of Medicine, Boston, MA, USA
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18
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Helfer BM, Bulte JW. Cell Surveillance Using Magnetic Resonance Imaging. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00042-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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19
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Zhang Y, Huang D, Zhang C, Meng J, Tan B, Deng Z. IQF characterization of a cathepsin B-responsive nanoprobe for report of differentiation of HL60 cells into macrophages. RSC Adv 2021; 11:16522-16529. [PMID: 35479137 PMCID: PMC9031808 DOI: 10.1039/d1ra01549d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/18/2021] [Indexed: 12/14/2022] Open
Abstract
Tracking of in vivo fates of exogenous cell transplants in terms of viability, migration, directional differentiation and function delivery by a suitable method of medical imaging is of great significance in the development and application of various cell therapies. In this contribution directional differentiation of HL60 cells into macrophages and granulocytes, and a difference in the associated expression level of cathepsin B (Cat B) among the parent and daughter cells is used as a model to guide and evaluate the development of a Cat B-responsive Abz-FRFK-Dnp@PLGA nanoprobe for an optical report of the differentiation process. A well-documented internally quenched fluorescence (IQF) pair coupled with a peptide substrate FRFK of Cat B was synthesized and imbedded in PLGA to form the nanoprobe. The nanoprobe is resistant to leakage when dispersed in water for 10 days. Degradation of the nanoprobe is dominated by Cat B. HL60 cells were then labelled with the Abz-FRFK-Dnp@PLGA nanoprobe to track the differentiation process. Differentiation of labelled HL60 cells into macrophages exhibited a significantly higher fluorescence relative to the granulocytes or the labelled parent cells. The fluorescence difference allows the differentiation process to be followed. The established characterization and assessment procedure is to be used for the development and evaluation of nanoprobes for other imaging modalities. A Cat B-responsive Abz-FRFK-Dnp@PLGA nanoprobe for an optical report of the differentiation of HL60 cells into macrophages.![]()
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Affiliation(s)
- Yanhui Zhang
- School of Nano-Tech and Nano-Bionics
- University of Science and Technology of China
- Hefei
- P. R. China
- CAS Key Laboratory of Nano-Bio Interface
| | - Dehua Huang
- CAS Key Laboratory of Nano-Bio Interface
- Suzhou Institute of Nano-tech and Nano-bionics
- Chinese Academy of Sciences
- Suzhou
- P. R. China
| | - Chengxing Zhang
- CAS Key Laboratory of Nano-Bio Interface
- Suzhou Institute of Nano-tech and Nano-bionics
- Chinese Academy of Sciences
- Suzhou
- P. R. China
| | - Jingjing Meng
- CAS Key Laboratory of Nano-Bio Interface
- Suzhou Institute of Nano-tech and Nano-bionics
- Chinese Academy of Sciences
- Suzhou
- P. R. China
| | - Bo Tan
- CAS Key Laboratory of Nano-Bio Interface
- Suzhou Institute of Nano-tech and Nano-bionics
- Chinese Academy of Sciences
- Suzhou
- P. R. China
| | - Zongwu Deng
- School of Nano-Tech and Nano-Bionics
- University of Science and Technology of China
- Hefei
- P. R. China
- CAS Key Laboratory of Nano-Bio Interface
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20
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Shapiro MG. Reporter Genes for Ultrasound and MRI. Mol Imaging 2021. [DOI: 10.1016/b978-0-12-816386-3.00051-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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21
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Perlman O, Ito H, Gilad AA, McMahon MT, Chiocca EA, Nakashima H, Farrar CT. Redesigned reporter gene for improved proton exchange-based molecular MRI contrast. Sci Rep 2020; 10:20664. [PMID: 33244130 PMCID: PMC7692519 DOI: 10.1038/s41598-020-77576-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 11/05/2020] [Indexed: 02/07/2023] Open
Abstract
Reporter gene imaging allows for non-invasive monitoring of molecular processes in living cells, providing insights on the mechanisms underlying pathology and therapy. A lysine-rich protein (LRP) chemical exchange saturation transfer (CEST) MRI reporter gene has previously been developed and used to image tumor cells, cardiac viral gene transfer, and oncolytic virotherapy. However, the highly repetitive nature of the LRP reporter gene sequence leads to DNA recombination events and the expression of a range of truncated LRP protein fragments, thereby greatly limiting the CEST sensitivity. Here we report the use of a redesigned LRP reporter (rdLRP), aimed to provide excellent stability and CEST sensitivity. The rdLRP contains no DNA repeats or GC rich regions and 30% less positively charged amino-acids. RT-PCR of cell lysates transfected with rdLRP demonstrated a stable reporter gene with a single distinct band corresponding to full-length DNA. A distinct increase in CEST-MRI contrast was obtained in cell lysates of rdLRP transfected cells and in in vivo LRP expressing mouse brain tumors ([Formula: see text], n = 10).
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Affiliation(s)
- Or Perlman
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, 149 13th Street, Suite 2301, Charlestown, MA, 02129, USA
| | - Hirotaka Ito
- Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Assaf A Gilad
- Department of Biomedical Engineering, Michigan State University, East Lansing, MI, USA
- The Institute of Quantitative Health Science and Engineering, Michigan State University, East Lansing, MI, USA
- Department of Radiology, Michigan State University, East Lansing, MI, USA
| | - Michael T McMahon
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, USA
- Division of MR Research, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - E Antonio Chiocca
- Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Hiroshi Nakashima
- Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Christian T Farrar
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, 149 13th Street, Suite 2301, Charlestown, MA, 02129, USA.
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22
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Liu T, Zhu Y, Zhao R, Wei X, Xin X. Visualization of exosomes from mesenchymal stem cells in vivo by magnetic resonance imaging. Magn Reson Imaging 2020; 68:75-82. [PMID: 32027941 DOI: 10.1016/j.mri.2020.02.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 02/01/2020] [Accepted: 02/01/2020] [Indexed: 12/25/2022]
Abstract
BACKGROUND AND PURPOSE We develop a method of imaging exosomes in vivo according to the vital role of exosomes in intercellular communication. This study aims to design a new label method that allows the visualization of labeled exosomes with magnetic resonance imaging (MRI). METHODS We designed a fusion protein consisting of two parts, namely, ferritin heavy chain (FTH1) and a truncated lactadherin. FTH1 is used as an MRI reporter. Lactadherin is a trans-membrane protein. The lactadherin protein are mostly located on the outer surface of exosomes. We replaced the outer membrane part of lactadherin with FTH1, infected mesenchymal stem cells with lentivirus carrying the fusion protein, and isolated exosomes from the labeled cells by ultracentrifugation. Labeled exosomes were validated by transmission electron microscopy images, Western blot, nanosight particle tracking, and visualized in vitro and in vivo by MRI. RESULTS FTH1 expression would suppress mesenchymal stem cell proliferation, whereas the characterization of labeled exosomes remains comparable with unlabeled exosomes. MR imaging shows that exosomes labeled with FTH1 can be visualized in vitro and in vivo. CONCLUSION This innovative reporter-imaging approach to track and visualize exosomes with MRI can be utilized as a tool for the study of the role of exosomes under different conditions.
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Affiliation(s)
- Tianqi Liu
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, Guangdong, China
| | - Yurong Zhu
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, Guangdong, China
| | - Ruiting Zhao
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, Guangdong, China
| | - Xinhua Wei
- Department of Radiology, Guangzhou First People's Hospital, South China University of Technology, Guangzhou 510180, Guangdong, China
| | - Xuegang Xin
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, Guangdong, China; School of Medicine, South China University of Technology, Guangzhou 510006, Guangdong, China.
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23
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Zheng N, Su P, Liu Y, Wang H, Nie B, Fang X, Xu Y, Lin K, Lv P, He X, Guo Y, Shan B, Manyande A, Wang J, Xu F. Detection of neural connections with ex vivo MRI using a ferritin-encoding trans-synaptic virus. Neuroimage 2019; 197:133-142. [DOI: 10.1016/j.neuroimage.2019.04.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 03/06/2019] [Accepted: 04/11/2019] [Indexed: 12/11/2022] Open
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The Continuing Evolution of Molecular Functional Imaging in Clinical Oncology: The Road to Precision Medicine and Radiogenomics (Part II). Mol Diagn Ther 2019; 23:27-51. [PMID: 30387041 DOI: 10.1007/s40291-018-0367-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The present era of precision medicine sees "cancer" as a consequence of molecular derangements occurring at the commencement of the disease process, with morphological changes happening much later in the process of tumourigenesis. Conventional imaging techniques, such as computed tomography (CT), ultrasound (US) and magnetic resonance imaging (MRI) play an integral role in the detection of disease at the macroscopic level. However, molecular functional imaging (MFI) techniques entail the visualisation and quantification of biochemical and physiological processes occurring during tumourigenesis. MFI has the potential to play a key role in heralding the transition from the concept of "one-size-fits-all" treatment to "precision medicine". Integration of MFI with other fields of tumour biology such as genomics has spawned a novel concept called "radiogenomics", which could serve as an indispensable tool in translational cancer research. With recent advances in medical image processing, such as texture analysis, deep learning and artificial intelligence, the future seems promising; however, their clinical utility remains unproven at present. Despite the emergence of novel imaging biomarkers, the majority of these require validation before clinical translation is possible. In this two part review, we discuss the systematic collaboration across structural, anatomical and molecular imaging techniques that constitute MFI. Part I reviews positron emission tomography, radiogenomics, AI, and optical imaging, while part II reviews MRI, CT and ultrasound, their current status, and recent advances in the field of precision oncology.
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Zhang Q, Lu Y, Xu X, Li S, Du Y, Yu R. MR molecular imaging of HCC employing a regulated ferritin gene carried by a modified polycation vector. Int J Nanomedicine 2019; 14:3189-3201. [PMID: 31118631 PMCID: PMC6504634 DOI: 10.2147/ijn.s191270] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 03/19/2019] [Indexed: 01/03/2023] Open
Abstract
Purpose: Early diagnosis is essential for reducing liver cancer mortality, and molecular diagnosis by magnetic resonance imaging (MRI) is an emerging and promising technology. The chief aim of the present work is to use the ferritin gene, modified by the alpha-fetoprotein (AFP) promoter, carried by a highly safe vector, to produce signal contrast on T2-weighted MR imaging as an endogenous contrast agent, and to provide a highly specific target for subsequent therapy. Methods: Polyethyleneimine-β-cyclodextrin (PEI-β-CD, PC) was synthesized as a novel vector. The optimal nitrogen/phosphorus ratio (N/P) of the PC/plasmid DNA complex was determined by gel retardation, biophysical properties and transmission electron microscopy morphological analysis. The transfection efficiency was observed under a fluorescence microscope and analyzed by flow cytometry. Cellular iron accumulation caused by ferritin overexpression was verified by Prussian blue staining, and the resulting contrast imaging effect was examined by MRI. Results: The modified cationic polymer PC was much safer than high molecular weight PEI, and could condense plasmid DNA at an N/P ratio of 50 with suitable biophysical properties and a high transfection efficiency. Overexpression of ferritin enriched intracellular iron. The short-term iron imbalance initiated by AFP promoter regulation only occurred in hepatoma cells, resulting in signal contrast on MRI. The specific target TfR was also upregulated during this process. Conclusion: These results illustrate that the regulated ferritin gene carried by PC can be used as an endogenous contrast agent for MRI detection of hepatocellular carcinoma (HCC). This molecular imaging technique may promote safer early diagnosis of HCC, and provide a more highly specific target for future chemotherapy drugs.
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Affiliation(s)
- Qian Zhang
- Department of Radiology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, People's Republic of China
| | - Yuanfei Lu
- Department of Radiology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, People's Republic of China
| | - Xiaoling Xu
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, People's Republic of China
| | - Shujuan Li
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, People's Republic of China
| | - Yongzhong Du
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, People's Republic of China
| | - Risheng Yu
- Department of Radiology, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, People's Republic of China
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Neeman M. Perspectives: MRI of angiogenesis. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2018; 292:99-105. [PMID: 29705037 PMCID: PMC6542363 DOI: 10.1016/j.jmr.2018.04.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Revised: 04/03/2018] [Accepted: 04/11/2018] [Indexed: 05/07/2023]
Abstract
Angiogenesis, the expansion of the vascular bed, is an important component in remodeling of tissues and organs. Such remodeling is essential for coping with substantial and sustained increase in the demands for supply of oxygen and nutrients and the timely removal of waste products. The vasculature, and its effectiveness in systemic delivery to all parts of the body, regulates the distribution of immune cells and the delivery of therapeutics as well as the dissemination of disease. Therefore, the vascular bed is possibly one of the key organs involved in homeostasis, in health and disease. The critical role of the vasculature in health, and the accessibility to non invasive probing by MRI, renders MRI as a modality of choice for monitoring the vasculature and its adaption to challenges.
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Affiliation(s)
- Michal Neeman
- Department of Biological Regulation, The Weizmann Institute of Science, Rehovot 76100, Israel.
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27
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Quantifying iron content in magnetic resonance imaging. Neuroimage 2018; 187:77-92. [PMID: 29702183 DOI: 10.1016/j.neuroimage.2018.04.047] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 04/13/2018] [Accepted: 04/20/2018] [Indexed: 01/19/2023] Open
Abstract
Measuring iron content has practical clinical indications in the study of diseases such as Parkinson's disease, Huntington's disease, ferritinopathies and multiple sclerosis as well as in the quantification of iron content in microbleeds and oxygen saturation in veins. In this work, we review the basic concepts behind imaging iron using T2, T2*, T2', phase and quantitative susceptibility mapping in the human brain, liver and heart, followed by the applications of in vivo iron quantification in neurodegenerative diseases, iron tagged cells and ultra-small superparamagnetic iron oxide (USPIO) nanoparticles.
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29
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He X, Cai J, Li H, Liu B, Qin Y, Zhong Y, Wang L, Liao Y. In Vivo magnetic resonance imaging of xenografted tumors using FTH1 reporter gene expression controlled by a tet-on switch. Oncotarget 2018; 7:78591-78604. [PMID: 27732930 PMCID: PMC5346662 DOI: 10.18632/oncotarget.12519] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 10/03/2016] [Indexed: 12/28/2022] Open
Abstract
As a promising magnetic resonance imaging (MRI) reporter, ferritin has been used to track cells in vivo; however, its continuous overexpression can be cytotoxic, which restricts its application. In this study, we aimed to develop a switch to turn this genetic reporter “on” or “off” while monitoring cell grafts via MRI. To accomplish this, we genetically modified the ferritin heavy chain (FTH1) with a Tet-On switch and assessed the expression of FTH1 in transduced neuroblastoma cells (SK-N-SH) in vitro and in xenografted tumors in vivo. We found that FTH1 expression induced by doxycycline (Dox) in SK-N-SH-FTH1 cells depended on treatment dose and duration. We successfully detected T2-weighted MRI contrast in cell grafts after switching “on” the reporter gene using Dox, and this contrast disappeared when we switched it “off”. The genetic reporter FTH1 can thus be switched “on” or “off” throughout longitudinal monitoring of cell grafts, limiting expression to when MRI contrast is needed. The controllable imaging system we have developed minimizes risks from constitutive reporter gene overexpression and facilitates tumor cell monitoring in vitro and in vivo.
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Affiliation(s)
- Xiaoya He
- Department of Radiology, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.,Key Laboratory of Pediatrics in Chongqing, Chongqing, China.,Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China
| | - Jinhua Cai
- Department of Radiology, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.,Key Laboratory of Pediatrics in Chongqing, Chongqing, China.,Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China
| | - Hao Li
- Department of Radiology, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.,Key Laboratory of Pediatrics in Chongqing, Chongqing, China.,Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China
| | - Bo Liu
- Department of Radiology, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.,Key Laboratory of Pediatrics in Chongqing, Chongqing, China.,Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China
| | - Yong Qin
- Department of Radiology, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.,Key Laboratory of Pediatrics in Chongqing, Chongqing, China.,Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China
| | - Yi Zhong
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.,Key Laboratory of Pediatrics in Chongqing, Chongqing, China.,Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China
| | - Longlun Wang
- Department of Radiology, Children's Hospital of Chongqing Medical University, Chongqing, China.,Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.,Key Laboratory of Pediatrics in Chongqing, Chongqing, China.,Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China
| | - Yifan Liao
- Ministry of Education Key Laboratory of Child Development and Disorders, Chongqing, China.,Key Laboratory of Pediatrics in Chongqing, Chongqing, China.,Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Chongqing, China
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30
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Mukherjee A, Davis HC, Ramesh P, Lu GJ, Shapiro MG. Biomolecular MRI reporters: Evolution of new mechanisms. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2017; 102-103:32-42. [PMID: 29157492 PMCID: PMC5726449 DOI: 10.1016/j.pnmrs.2017.05.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 05/23/2017] [Accepted: 05/28/2017] [Indexed: 05/08/2023]
Abstract
Magnetic resonance imaging (MRI) is a powerful technique for observing the function of specific cells and molecules inside living organisms. However, compared to optical microscopy, in which fluorescent protein reporters are available to visualize hundreds of cellular functions ranging from gene expression and chemical signaling to biomechanics, to date relatively few such reporters are available for MRI. Efforts to develop MRI-detectable biomolecules have mainly focused on proteins transporting paramagnetic metals for T1 and T2 relaxation enhancement or containing large numbers of exchangeable protons for chemical exchange saturation transfer. While these pioneering developments established several key uses of biomolecular MRI, such as imaging of gene expression and functional biosensing, they also revealed that low molecular sensitivity poses a major challenge for broader adoption in biology and medicine. Recently, new classes of biomolecular reporters have been developed based on alternative contrast mechanisms, including enhancement of spin diffusivity, interactions with hyperpolarized nuclei, and modulation of blood flow. These novel reporters promise to improve sensitivity and enable new forms of multiplexed and functional imaging.
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Affiliation(s)
- Arnab Mukherjee
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Hunter C Davis
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Pradeep Ramesh
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - George J Lu
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Mikhail G Shapiro
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
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31
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Jiang C, Wu D, Haacke EM. Ferritin-EGFP Chimera as an Endogenous Dual-Reporter for Both Fluorescence and Magnetic Resonance Imaging in Human Glioma U251 Cells. ACTA ACUST UNITED AC 2017; 3:1-8. [PMID: 30042970 PMCID: PMC6024424 DOI: 10.18383/j.tom.2015.00181] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A unique hybrid protein ferritin–enhanced green fluorescent protein (EGFP) was built to serve as an endogenous dual reporter for both fluorescence and magnetic resonance imaging (MRI). It consists of a human ferritin heavy chain (an iron-storage protein) at the N terminus, a flexible polypeptide in the middle as a linker, and an EGFP at the C terminus. Through antibiotic screening, we established stable human glioma U251 cell strains that expressed ferritin–EGFP under the control of tetracycline. These cells emitted bright green fluorescence and were easily detected by a fluorescent microscope. Ferritin–EGFP overexpression proved effective in triggering obvious intracellular iron accumulation as shown by Prussian blue staining and by MRI. Further, we found that ferritin–EGFP overexpression did not cause proliferation differences between experimental and control group cells when ferritin–EGFP was expressed for <96 hours. Application of this novel ferritin–EGFP chimera has a promising future for combined optical and MRI approaches to study in vivo imaging at a cellular level.
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Affiliation(s)
- Caihong Jiang
- Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai, China and
| | - Dongmei Wu
- Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai, China and
| | - E Mark Haacke
- Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, Shanghai, China and.,Department of Radiology, Wayne State University, Detroit, Michigan
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32
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Genetically encoded iron-associated proteins as MRI reporters for molecular and cellular imaging. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2017; 10. [DOI: 10.1002/wnan.1482] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 04/18/2017] [Accepted: 05/04/2017] [Indexed: 02/06/2023]
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33
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Shin N, Hanaoka K, Piao W, Miyakawa T, Fujisawa T, Takeuchi S, Takahashi S, Komatsu T, Ueno T, Terai T, Tahara T, Tanokura M, Nagano T, Urano Y. Development of an Azoreductase-based Reporter System with Synthetic Fluorogenic Substrates. ACS Chem Biol 2017; 12:558-563. [PMID: 28036168 DOI: 10.1021/acschembio.6b00852] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Enzyme/substrate pairs, such as β-galactosidase with chromogenic x-gal substrate, are widely used as reporters to monitor biological events, but there is still a requirement for new reporter systems, which may be orthogonal to existing systems. Here, we focused on azoreductase (AzoR). We designed and synthesized a library of azo-rhodamine derivatives as candidate fluorogenic substrates. These derivatives were nonfluorescent, probably due to ultrafast conformational change around the N═N bond after photoexcitation. We found that AzoR-mediated reduction of the azo bond of derivatives bearing an electron-donating group on the azobenzene moiety was followed by nonenzymatic cleavage to afford highly fluorescent 2-methyl-rhodamine green (2-Me RG), which was well retained in cells. We show that the AzoR/compound 9 reporter system can detect azoreductase-expressing live cells at the single cell level.
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Affiliation(s)
- Narae Shin
- Graduate
School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Kenjiro Hanaoka
- Graduate
School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Wen Piao
- Graduate
School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Takuya Miyakawa
- Department
of Applied Biological Chemistry, Graduate School of Agricultural and
Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | | | - Satoshi Takeuchi
- Molecular
Spectroscopy Laboratory, RIKEN, Wako 351-0198, Japan
- Ultrafast
Spectroscopy Research Team, RIKEN Center for Advanced Photonics (RAP), RIKEN, Wako 351-0198, Japan
| | - Shodai Takahashi
- Graduate
School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Toru Komatsu
- Graduate
School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
- PRESTO, Japan Science and Technology Agency, Saitama 332-0012, Japan
| | - Tasuku Ueno
- Graduate
School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Takuya Terai
- Graduate
School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Tahei Tahara
- Molecular
Spectroscopy Laboratory, RIKEN, Wako 351-0198, Japan
- Ultrafast
Spectroscopy Research Team, RIKEN Center for Advanced Photonics (RAP), RIKEN, Wako 351-0198, Japan
| | - Masaru Tanokura
- Department
of Applied Biological Chemistry, Graduate School of Agricultural and
Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Tetsuo Nagano
- Drug
Discovery Initiative, The University of Tokyo, Tokyo 113-0033, Japan
| | - Yasuteru Urano
- Graduate
School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
- Graduate
School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
- AMED CREST (Japan) Agency for Medical Research and Development, Tokyo 100-0004, Japan
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Advances in Monitoring Cell-Based Therapies with Magnetic Resonance Imaging: Future Perspectives. Int J Mol Sci 2017; 18:ijms18010198. [PMID: 28106829 PMCID: PMC5297829 DOI: 10.3390/ijms18010198] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 01/05/2017] [Accepted: 01/10/2017] [Indexed: 01/07/2023] Open
Abstract
Cell-based therapies are currently being developed for applications in both regenerative medicine and in oncology. Preclinical, translational, and clinical research on cell-based therapies will benefit tremendously from novel imaging approaches that enable the effective monitoring of the delivery, survival, migration, biodistribution, and integration of transplanted cells. Magnetic resonance imaging (MRI) offers several advantages over other imaging modalities for elucidating the fate of transplanted cells both preclinically and clinically. These advantages include the ability to image transplanted cells longitudinally at high spatial resolution without exposure to ionizing radiation, and the possibility to co-register anatomical structures with molecular processes and functional changes. However, since cellular MRI is still in its infancy, it currently faces a number of challenges, which provide avenues for future research and development. In this review, we describe the basic principle of cell-tracking with MRI; explain the different approaches currently used to monitor cell-based therapies; describe currently available MRI contrast generation mechanisms and strategies for monitoring transplanted cells; discuss some of the challenges in tracking transplanted cells; and suggest future research directions.
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Lee CW, Choi SI, Lee SJ, Oh YT, Park G, Park NY, Yoon KA, Kim S, Kim D, Kim YH, Suh JS. The Effectiveness of Ferritin as a Contrast Agent for Cell Tracking MRI in Mouse Cancer Models. Yonsei Med J 2017; 58:51-58. [PMID: 27873495 PMCID: PMC5122652 DOI: 10.3349/ymj.2017.58.1.51] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 06/18/2016] [Accepted: 06/20/2016] [Indexed: 12/24/2022] Open
Abstract
PURPOSE We aimed to investigate the effectiveness of ferritin as a contrast agent and a potential reporter gene for tracking tumor cells or macrophages in mouse cancer models. MATERIALS AND METHODS Adenoviral human ferritin heavy chain (Ad-hFTH) was administrated to orthotopic glioma models and subcutaneous colon cancer mouse models using U87MG and HCT116 cells, respectively. Brain MR images were acquired before and daily for up to 6 days after the intracranial injection of Ad-hFTH. In the HCT116 tumor model, MR examinations were performed before and at 6, 24, and 48 h after intratumoral injection of Ad-hFTH, as well as before and every two days after intravenous injection of ferritin-labeled macrophages. The contrast effect of ferritin in vitro was measured by MR imaging of cell pellets. MRI examinations using a 7T MR scanner comprised a T1-weighted (T1w) spin-echo sequence, T2-weighted (T2w) relaxation enhancement sequence, and T2*-weighted (T2*w) fast low angle shot sequence. RESULTS Cell pellet imaging of Ad-hFTH in vitro showed a strong negatively enhanced contrast in T2w and T2*w images, presenting with darker signal intensity in high concentrations of Fe. T2w images of glioma and subcutaneous HCT116 tumor models showed a dark signal intensity around or within the Ad-hFTH tumor, which was distinct with time and apparent in T2*w images. After injection of ferritin-labeled macrophages, negative contrast enhancement was identified within the tumor. CONCLUSION Ferritin could be a good candidate as an endogenous MR contrast agent and a potential reporter gene that is capable of maintaining cell labeling stability and cellular safety.
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Affiliation(s)
- Chan Wha Lee
- Department of Medicine, The Graduate School of Yonsei University, Seoul, Korea
- Research Institute & Hospital, National Cancer Center, Goyang, Korea
| | - Sun Il Choi
- Research Institute & Hospital, National Cancer Center, Goyang, Korea
- Department of Life Science, Ewha Womans University, Seoul, Korea
| | - Sang Jin Lee
- Research Institute & Hospital, National Cancer Center, Goyang, Korea
- Department of System Cancer Science, Graduate School of Cancer Science & Policy, National Cancer Center, Goyang, Korea
| | - Young Taek Oh
- Research Institute & Hospital, National Cancer Center, Goyang, Korea
| | - Gunwoo Park
- Research Institute & Hospital, National Cancer Center, Goyang, Korea
| | - Na Yeon Park
- Department of System Cancer Science, Graduate School of Cancer Science & Policy, National Cancer Center, Goyang, Korea
| | - Kyoung Ah Yoon
- College of Veterinary Medicine, Konkuk University, Seoul, Korea
| | - Sunshin Kim
- Research Institute & Hospital, National Cancer Center, Goyang, Korea
| | - Daehong Kim
- Research Institute & Hospital, National Cancer Center, Goyang, Korea.
| | - Yun Hee Kim
- Research Institute & Hospital, National Cancer Center, Goyang, Korea
- Department of System Cancer Science, Graduate School of Cancer Science & Policy, National Cancer Center, Goyang, Korea.
| | - Jin Suck Suh
- Department of Medicine, The Graduate School of Yonsei University, Seoul, Korea
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36
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Non-invasive imaging using reporter genes altering cellular water permeability. Nat Commun 2016; 7:13891. [PMID: 28008959 PMCID: PMC5196229 DOI: 10.1038/ncomms13891] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 11/10/2016] [Indexed: 12/19/2022] Open
Abstract
Non-invasive imaging of gene expression in live, optically opaque animals is important for multiple applications, including monitoring of genetic circuits and tracking of cell-based therapeutics. Magnetic resonance imaging (MRI) could enable such monitoring with high spatiotemporal resolution. However, existing MRI reporter genes based on metalloproteins or chemical exchange probes are limited by their reliance on metals or relatively low sensitivity. Here we introduce a new class of MRI reporters based on the human water channel aquaporin 1. We show that aquaporin overexpression produces contrast in diffusion-weighted MRI by increasing tissue water diffusivity without affecting viability. Low aquaporin levels or mixed populations comprising as few as 10% aquaporin-expressing cells are sufficient to produce MRI contrast. We characterize this new contrast mechanism through experiments and simulations, and demonstrate its utility in vivo by imaging gene expression in tumours. Our results establish an alternative class of sensitive, metal-free reporter genes for non-invasive imaging. Magnetic resonance imaging combined with molecular reporters can visualise cellular functions in intact organisms. Here Mukherjee et al. present a cellular imaging approach based on intracellular changes in water diffusion using human aquaporin 1 gene as a genetically encoded reporter for MRI.
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Matteucci M, Casieri V, Gabisonia K, Aquaro GD, Agostini S, Pollio G, Diamanti D, Rossi M, Travagli M, Porcari V, Recchia FA, Lionetti V. Magnetic resonance imaging of infarct-induced canonical wingless/integrated (Wnt)/β-catenin/T-cell factor pathway activation, in vivo. Cardiovasc Res 2016; 112:645-655. [PMID: 27671803 DOI: 10.1093/cvr/cvw214] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 09/06/2016] [Accepted: 09/15/2016] [Indexed: 01/16/2023] Open
Abstract
AIMS Combined magnetic resonance imaging (MRI) of molecular and morpho-functional changes might prove highly valuable for the elucidation of pathological processes involved in the development of cardiac diseases. Our aim was to test a novel MRI reporter gene for in vivo assessment of the canonical Wnt/β-catenin/TCF pathway activation, an important regulator of post-ischaemic cardiac remodelling. METHODS AND RESULTS We designed and developed a chimeric construct encoding for both of iron-binding human ferritin heavy chain (hFTH) controlled by the β-catenin-responsive TCF/lymphoid-enhancer binding factor (Lef) promoter and constitutively expressed green fluorescent protein (GFP). It was carried by adeno-associated virus serotype 9 (rAAV9) vectors and delivered to the peri-infarct myocardium of rats subjected to coronary ligation (n = 11). By 1.5 T MRI and a multiecho T2* gradient echo sequence, we detected iron accumulation only in the border zone of the transduced infarcted hearts. In the same cardiac area, post-mortem histological analysis confirmed the co-existence of iron accumulation and GFP. The iron signal was absent when rats (n = 6) were chronically treated with SEN195 (10 mg/kg/day), a small-molecular inhibitor of β-catenin/TCF-dependent gene transcription. Canonical Wnt pathway inhibition attenuated the post-ischaemic remodelling process, as demonstrated by the significant preservation of cardiac function, the 42 ± 1% increase of peri-infarct arteriolar density and 43 ± 3% reduction in infarct scar size compared with untreated animals. CONCLUSIONS The TCF/Lef promoter-hFTH construct is a novel and reliable MRI reporter gene for in vivo detection of the canonical Wnt/β-catenin/TCF activation state in response to cardiac injury and therapeutic interventions.
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Affiliation(s)
- Marco Matteucci
- Laboratory of Medical Science, Institute of Life Sciences, Scuola Superiore Sant'Anna, Via G. Moruzzi, 1, 56124 Pisa, Italy
| | - Valentina Casieri
- Laboratory of Medical Science, Institute of Life Sciences, Scuola Superiore Sant'Anna, Via G. Moruzzi, 1, 56124 Pisa, Italy
| | - Khatia Gabisonia
- Laboratory of Medical Science, Institute of Life Sciences, Scuola Superiore Sant'Anna, Via G. Moruzzi, 1, 56124 Pisa, Italy
| | | | - Silvia Agostini
- Laboratory of Medical Science, Institute of Life Sciences, Scuola Superiore Sant'Anna, Via G. Moruzzi, 1, 56124 Pisa, Italy
| | | | | | - Marco Rossi
- Siena Biotech Medicine Research Centre, 53100 Siena, Italy
| | | | | | - Fabio A Recchia
- Laboratory of Medical Science, Institute of Life Sciences, Scuola Superiore Sant'Anna, Via G. Moruzzi, 1, 56124 Pisa, Italy.,Cardiovascular Research Center, Lewis Katz School of Medicine, Temple University, 19140 Philadelphia, PA, USA
| | - Vincenzo Lionetti
- Laboratory of Medical Science, Institute of Life Sciences, Scuola Superiore Sant'Anna, Via G. Moruzzi, 1, 56124 Pisa, Italy .,Fondazione Toscana 'G. Monasterio', 56124 Pisa, Italy
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Abstract
UNLABELLED Comprehensive analysis of brain function depends on understanding the dynamics of diverse neural signaling processes over large tissue volumes in intact animals and humans. Most existing approaches to measuring brain signaling suffer from limited tissue penetration, poor resolution, or lack of specificity for well-defined neural events. Here we discuss a new brain activity mapping method that overcomes some of these problems by combining MRI with contrast agents sensitive to neural signaling. The goal of this "molecular fMRI" approach is to permit noninvasive whole-brain neuroimaging with specificity and resolution approaching current optical neuroimaging methods. In this article, we describe the context and need for molecular fMRI as well as the state of the technology today. We explain how major types of MRI probes work and how they can be sensitized to neurobiological processes, such as neurotransmitter release, calcium signaling, and gene expression changes. We comment both on past work in the field and on challenges and promising avenues for future development. SIGNIFICANCE STATEMENT Brain researchers currently have a choice between measuring neural activity using cellular-level recording techniques, such as electrophysiology and optical imaging, or whole-brain imaging methods, such as fMRI. Cellular level methods are precise but only address a small portion of mammalian brains; on the other hand, whole-brain neuroimaging techniques provide very little specificity for neural pathways or signaling components of interest. The molecular fMRI techniques we discuss have particular potential to combine the specificity of cellular-level measurements with the noninvasive whole-brain coverage of fMRI. On the other hand, molecular fMRI is only just getting off the ground. This article aims to offer a snapshot of the status and future prospects for development of molecular fMRI techniques.
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Radoul M, Lewin L, Cohen B, Oren R, Popov S, Davidov G, Vandsburger MH, Harmelin A, Bitton R, Greneche JM, Neeman M, Zarivach R. Genetic manipulation of iron biomineralization enhances MR relaxivity in a ferritin-M6A chimeric complex. Sci Rep 2016; 6:26550. [PMID: 27211820 PMCID: PMC4876375 DOI: 10.1038/srep26550] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 05/04/2016] [Indexed: 01/07/2023] Open
Abstract
Ferritin has gained significant attention as a potential reporter gene for in vivo imaging by magnetic resonance imaging (MRI). However, due to the ferritin ferrihydrite core, the relaxivity and sensitivity for detection of native ferritin is relatively low. We report here on a novel chimeric magneto-ferritin reporter gene - ferritin-M6A - in which the magnetite binding peptide from the magnetotactic bacteria magnetosome-associated Mms6 protein was fused to the C-terminal of murine h-ferritin. Biophysical experiments showed that purified ferritin-M6A assembled into a stable protein cage with the M6A protruding into the cage core, enabling magnetite biomineralisation. Ferritin-M6A-expressing C6-glioma cells showed enhanced (per iron) r2 relaxivity. MRI in vivo studies of ferritin-M6A-expressing tumour xenografts showed enhanced R2 relaxation rate in the central hypoxic region of the tumours. Such enhanced relaxivity would increase the sensitivity of ferritin as a reporter gene for non-invasive in vivo MRI-monitoring of cell delivery and differentiation in cellular or gene-based therapies.
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Affiliation(s)
- Marina Radoul
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 76100 Israel
| | - Limor Lewin
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, POB 653, Beer-Sheva 84105, Israel
| | - Batya Cohen
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 76100 Israel
| | - Roni Oren
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 76100 Israel
| | - Stanislav Popov
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, POB 653, Beer-Sheva 84105, Israel
| | - Geula Davidov
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, POB 653, Beer-Sheva 84105, Israel
| | - Moriel H. Vandsburger
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 76100 Israel
| | - Alon Harmelin
- Department of Veterinary Resources, Weizmann Institute of Science, Rehovot 76100 Israel
| | - Ronit Bitton
- Department of Chemical Engineering and Ilse Katz Institute for Nanoscale Science and Technology Ben-Gurion University of the Negev, 84105 Beer-Sheva, Israel
| | - Jean-Marc Greneche
- Institut des Molécules et Matériaux du Mans (IMMM), UMR CNRS 6283 Université du Maine, Avenue Olivier Messiaen, 72085 Le Mans Cedex France
| | - Michal Neeman
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 76100 Israel,
| | - Raz Zarivach
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, POB 653, Beer-Sheva 84105, Israel,
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40
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Yang Y, Gong MF, Yang H, Zhang S, Wang GX, Su TS, Wen L, Zhang D. MR molecular imaging of tumours using ferritin heavy chain reporter gene expression mediated by the hTERT promoter. Eur Radiol 2016; 26:4089-4097. [PMID: 26960542 PMCID: PMC5052315 DOI: 10.1007/s00330-016-4259-9] [Citation(s) in RCA: 10] [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: 06/02/2015] [Revised: 12/06/2015] [Accepted: 01/28/2016] [Indexed: 11/25/2022]
Abstract
Objectives Using the human telomerase reverse transcriptase (hTERT) promoter and the modified ferritin heavy chain (Fth) reporter gene, reporter gene expression for MRI was examined in telomerase positive and negative tumour cells and xenografts. Methods Activity of the reporter gene expression vector Lenti-hTERT-Fth1-3FLAG-Puro was compared to constitutive CMV-driven expression and to the untransfected parental control in five tumour cell lines: A549, SKOV3, 293T, U2OS and HPDLF. In vitro, transfected cells were evaluated for FLAG-tagged protein expression, iron accumulation and transverse relaxation. In vivo, tumours transduced by lentiviral vector injection were imaged using T2*WI. Changes in tumour signal intensity were validated by histology. Results Only telomerase positive tumour cells expressed FLAG-tagged Fth and displayed an increase in R2* above the parental control, with a corresponding change in T2*WI. In addition, only telomerase positive tumours, transduced by injection of the reporter gene expression construct, exhibited a change in signal intensity on T2*WI. Tumour histology verified the expression of FLAG-tagged Fth and iron accumulation in telomerase positive tissue. Conclusion Reporter gene expression for MRI, using the Fth reporter and the hTERT promoter, may be a useful strategy for the non-invasive diagnosis of many types of cancer. Key points • Modified heavy chain of ferritin can serve as an MR reporter gene • hTERT promoter can direct the expression of reporter gene in cancer cells • MR reporter imaging mediated by hTERT promoter can be used for cancer diagnosis
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Affiliation(s)
- Yan Yang
- Department of Radiology, XinQiao Hospital, Third Military Medical University, ChongQing, 400037, People's Republic of China
- Department of Radiology, The First Affiliated Hospital of ChengDu Medical College, ChengDu, 610500, People's Republic of China
| | - Ming-Fu Gong
- Department of Radiology, XinQiao Hospital, Third Military Medical University, ChongQing, 400037, People's Republic of China
| | - Hua Yang
- Department of Radiology, XinQiao Hospital, Third Military Medical University, ChongQing, 400037, People's Republic of China
| | - Song Zhang
- Department of Radiology, XinQiao Hospital, Third Military Medical University, ChongQing, 400037, People's Republic of China
| | - Guang-Xian Wang
- Department of Radiology, XinQiao Hospital, Third Military Medical University, ChongQing, 400037, People's Republic of China
| | - Tong-Sheng Su
- Department of Radiology, XinQiao Hospital, Third Military Medical University, ChongQing, 400037, People's Republic of China
| | - Li Wen
- Department of Radiology, XinQiao Hospital, Third Military Medical University, ChongQing, 400037, People's Republic of China.
| | - Dong Zhang
- Department of Radiology, XinQiao Hospital, Third Military Medical University, ChongQing, 400037, People's Republic of China.
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Bar-Shir A, Liang Y, Chan KWY, Gilad AA, Bulte JWM. Supercharged green fluorescent proteins as bimodal reporter genes for CEST MRI and optical imaging. Chem Commun (Camb) 2015; 51:4869-71. [PMID: 25697683 DOI: 10.1039/c4cc10195b] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Superpositively charged mutants of green fluorescent protein (GFP) demonstrated a dramatically improved chemical exchange saturation transfer (CEST) MRI contrast compared to their wild type counterparts. The mutants +36 GFP and +48 GFP were successfully expressed in mammalian cells and retained part of their fluorescence, making them a new potential bimodal reporter gene.
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Affiliation(s)
- Amnon Bar-Shir
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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42
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Abstract
Lineage tracing is a widely used method for understanding cellular dynamics in multicellular organisms during processes such as development, adult tissue maintenance, injury repair and tumorigenesis. Advances in tracing or tracking methods, from light microscopy-based live cell tracking to fluorescent label-tracing with two-photon microscopy, together with emerging tissue clearing strategies and intravital imaging approaches have enabled scientists to decipher adult stem and progenitor cell properties in various tissues and in a wide variety of biological processes. Although technical advances have enabled time-controlled genetic labeling and simultaneous live imaging, a number of obstacles still need to be overcome. In this review, we aim to provide an in-depth description of the traditional use of lineage tracing as well as current strategies and upcoming new methods of labeling and imaging.
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Affiliation(s)
| | | | - Bon-Kyoung Koo
- Department of Genetics and Wellcome Trust - Medical Research Council Stem Cell Institute, University of Cambridge, Cambridge, CB2 1QR, United Kingdom
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He X, Cai J, Liu B, Zhong Y, Qin Y. Cellular magnetic resonance imaging contrast generated by the ferritin heavy chain genetic reporter under the control of a Tet-On switch. Stem Cell Res Ther 2015; 6:207. [PMID: 26517988 PMCID: PMC4628232 DOI: 10.1186/s13287-015-0205-z] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2015] [Revised: 08/30/2015] [Accepted: 10/16/2015] [Indexed: 12/26/2022] Open
Abstract
INTRODUCTION Despite the strong appeal of ferritin as a magnetic resonance imaging (MRI) reporter for stem cell research, no attempts have been made to apply this genetic imaging reporter in stem cells in an inducible manner, which is important for minimizing the potential risk related to the constitutive expression of an imaging reporter. The aim of the present study was to develop an inducible genetic MRI reporter system that enables the production of intracellular MRI contrast as needed. METHODS Ferritin heavy chain (FTH1) was genetically modified by adding a Tet-On switch. A C3H10T1/2 cell line carrying Tet-FTH1 (C3H10T1/2-FTH1) was established via lentiviral transduction. The dose- and time-dependent expression of FTH1 in C3H10T1/2 cells was assessed by western blot and immunofluorescence staining. The induced "ON" and non-induced "OFF" expressions of FTH1 were detected using a 3.0 T MRI scanner. Iron accumulation in cells was analyzed by Prussian blue staining and transmission electron microscopy (TEM). RESULTS The expression of FTH1 was both dose- and time-dependently induced, and FTH1 expression peaked in response to induction with doxycycline (Dox) at 0.2 μg/ml for 72 h. The induced expression of FTH1 resulted in a significant increase in the transverse relaxation rate of C3H10T1/2-FTH1 cells following iron supplementation. Prussian blue staining and TEM revealed extensive iron accumulation in C3H10T1/2-FTH1 cells in the presence of Dox. CONCLUSIONS Cellular MRI contrast can be produced as needed via the expression of FTH1 under the control of a Tet-On switch. This finding could lay the groundwork for the use of FTH1 to track stem cells in vivo in an inducible manner.
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Affiliation(s)
- Xiaoya He
- Department of Radiology, Children's Hospital of Chongqing Medical University, 136 Zhongshan 2 Road, Yuzhong District, Chongqing, 400014, China. .,Ministry of Education Key Laboratory of Child Development and Disorders, 136 Zhongshan 2 Road, Yuzhong District, Chongqing, 400014, China. .,Key Laboratory of Pediatrics in Chongqing, 136 Zhongshan 2 Road, Yuzhong District, Chongqing, 400014, China. .,Chongqing International Science and Technology Cooperation Center For Child Development and Disorders, 136 Zhongshan 2 Road, Yuzhong District, Chongqing, 400014, China.
| | - Jinhua Cai
- Department of Radiology, Children's Hospital of Chongqing Medical University, 136 Zhongshan 2 Road, Yuzhong District, Chongqing, 400014, China. .,Ministry of Education Key Laboratory of Child Development and Disorders, 136 Zhongshan 2 Road, Yuzhong District, Chongqing, 400014, China. .,Key Laboratory of Pediatrics in Chongqing, 136 Zhongshan 2 Road, Yuzhong District, Chongqing, 400014, China. .,Chongqing International Science and Technology Cooperation Center For Child Development and Disorders, 136 Zhongshan 2 Road, Yuzhong District, Chongqing, 400014, China.
| | - Bo Liu
- Department of Radiology, Children's Hospital of Chongqing Medical University, 136 Zhongshan 2 Road, Yuzhong District, Chongqing, 400014, China. .,Ministry of Education Key Laboratory of Child Development and Disorders, 136 Zhongshan 2 Road, Yuzhong District, Chongqing, 400014, China. .,Key Laboratory of Pediatrics in Chongqing, 136 Zhongshan 2 Road, Yuzhong District, Chongqing, 400014, China. .,Chongqing International Science and Technology Cooperation Center For Child Development and Disorders, 136 Zhongshan 2 Road, Yuzhong District, Chongqing, 400014, China.
| | - Yi Zhong
- Department of Radiology, Children's Hospital of Chongqing Medical University, 136 Zhongshan 2 Road, Yuzhong District, Chongqing, 400014, China. .,Ministry of Education Key Laboratory of Child Development and Disorders, 136 Zhongshan 2 Road, Yuzhong District, Chongqing, 400014, China. .,Key Laboratory of Pediatrics in Chongqing, 136 Zhongshan 2 Road, Yuzhong District, Chongqing, 400014, China. .,Chongqing International Science and Technology Cooperation Center For Child Development and Disorders, 136 Zhongshan 2 Road, Yuzhong District, Chongqing, 400014, China.
| | - Yong Qin
- Department of Radiology, Children's Hospital of Chongqing Medical University, 136 Zhongshan 2 Road, Yuzhong District, Chongqing, 400014, China. .,Ministry of Education Key Laboratory of Child Development and Disorders, 136 Zhongshan 2 Road, Yuzhong District, Chongqing, 400014, China. .,Key Laboratory of Pediatrics in Chongqing, 136 Zhongshan 2 Road, Yuzhong District, Chongqing, 400014, China. .,Chongqing International Science and Technology Cooperation Center For Child Development and Disorders, 136 Zhongshan 2 Road, Yuzhong District, Chongqing, 400014, China.
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Assmann JC, Körbelin J, Schwaninger M. Genetic manipulation of brain endothelial cells in vivo. Biochim Biophys Acta Mol Basis Dis 2015; 1862:381-94. [PMID: 26454206 DOI: 10.1016/j.bbadis.2015.10.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 09/30/2015] [Accepted: 10/05/2015] [Indexed: 12/19/2022]
Affiliation(s)
- Julian C Assmann
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Jakob Körbelin
- University Medical Center Hamburg-Eppendorf, Hubertus Wald Cancer Center, Department of Oncology and Hematology, Martinistr. 52, 20246 Hamburg, Germany
| | - Markus Schwaninger
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany.
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Abstract
Molecular imaging plays an important role in the era of personalized medicine, especially with recent advances in magnetic resonance (MR) probes. While the first generation of these probes focused on maximizing contrast enhancement, a second generation of probes has been developed to improve the accumulation within specific tissues or pathologies, and the newest generation of agents is also designed to report on changes in physiological status and has been termed "smart" agents. This represents a paradigm switch from the previously commercialized gadolinium and iron oxide probes to probes with new capabilities, and leads to new challenges as scanner hardware needs to be adapted for detecting these probes. In this chapter, we highlight the unique features for all five different categories of MR probes, including the emerging chemical exchange saturation transfer, (19)F, and hyperpolarized probes, and describe the key physical properties and features motivating their design. As part of this comparison, the strengths and weaknesses of each category are discussed.
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Affiliation(s)
- Michael T McMahon
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA; The Russell H. Morgan Department of Radiology and Radiological Sciences, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
| | - Kannie W Y Chan
- F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland, USA; The Russell H. Morgan Department of Radiology and Radiological Sciences, Division of MR Research, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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46
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Bar-Shir A, Bulte JWM, Gilad AA. Molecular engineering of nonmetallic biosensors for CEST MRI. ACS Chem Biol 2015; 10:1160-70. [PMID: 25730583 PMCID: PMC11329289 DOI: 10.1021/cb500923v] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Recent advancements in molecular and synthetic biology, combined with synthetic chemistry and biotechnology, have opened up new opportunities to engineer novel platforms that can monitor complex biological processes with various noninvasive imaging modalities. After decades of using gadolinium- or iron-based metallic sensors for MRI, the recently developed chemical exchange saturation transfer (CEST) contrast mechanism has created an opportunity for rational design, in silico, of nonmetallic biosensors for MRI. These biomolecules are either naturally occurring compounds (amino acids, sugars, nucleosides, native proteins) or can be artificially engineered (synthetic probes or recombinant proteins). They can be administered either as exogenous agents or can be genetically (over)expressed. Moreover, they can be precisely engineered to achieve the desired biochemical properties for fine tuning optimized imaging schemes. The availability of these agents marks the dawn of a new scientific era for molecular and cellular MRI.
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Affiliation(s)
- Amnon Bar-Shir
- †Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States
- ‡Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
| | - Jeff W M Bulte
- †Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States
- ‡Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- §F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland 21205, United States
- ∥Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- #Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States
| | - Assaf A Gilad
- †Russell H. Morgan Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287, United States
- ‡Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States
- §F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland 21205, United States
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Srivastava AK, Kadayakkara DK, Bar-Shir A, Gilad AA, McMahon MT, Bulte JWM. Advances in using MRI probes and sensors for in vivo cell tracking as applied to regenerative medicine. Dis Model Mech 2015; 8:323-36. [PMID: 26035841 PMCID: PMC4381332 DOI: 10.1242/dmm.018499] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The field of molecular and cellular imaging allows molecules and cells to be visualized in vivo non-invasively. It has uses not only as a research tool but in clinical settings as well, for example in monitoring cell-based regenerative therapies, in which cells are transplanted to replace degenerating or damaged tissues, or to restore a physiological function. The success of such cell-based therapies depends on several critical issues, including the route and accuracy of cell transplantation, the fate of cells after transplantation, and the interaction of engrafted cells with the host microenvironment. To assess these issues, it is necessary to monitor transplanted cells non-invasively in real-time. Magnetic resonance imaging (MRI) is a tool uniquely suited to this task, given its ability to image deep inside tissue with high temporal resolution and sensitivity. Extraordinary efforts have recently been made to improve cellular MRI as applied to regenerative medicine, by developing more advanced contrast agents for use as probes and sensors. These advances enable the non-invasive monitoring of cell fate and, more recently, that of the different cellular functions of living cells, such as their enzymatic activity and gene expression, as well as their time point of cell death. We present here a review of recent advancements in the development of these probes and sensors, and of their functioning, applications and limitations.
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Affiliation(s)
- Amit K Srivastava
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Deepak K Kadayakkara
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Amnon Bar-Shir
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Assaf A Gilad
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD 21205, USA
| | - Michael T McMahon
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD 21205, USA
| | - Jeff W M Bulte
- Russell H. Morgan Department of Radiology and Radiological Science, Division of MR Research, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD 21205, USA. Department of Chemical & Biomolecular Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA. Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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Tennstaedt A, Aswendt M, Adamczak J, Collienne U, Selt M, Schneider G, Henn N, Schaefer C, Lagouge M, Wiedermann D, Kloppenburg P, Hoehn M. Human neural stem cell intracerebral grafts show spontaneous early neuronal differentiation after several weeks. Biomaterials 2015; 44:143-54. [DOI: 10.1016/j.biomaterials.2014.12.038] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 12/20/2014] [Indexed: 10/24/2022]
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49
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Gilad AA, Pelled G. New approaches for the neuroimaging of gene expression. Front Integr Neurosci 2015; 9:5. [PMID: 25698946 PMCID: PMC4316713 DOI: 10.3389/fnint.2015.00005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 01/13/2015] [Indexed: 01/19/2023] Open
Affiliation(s)
- Assaf A Gilad
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine Baltimore, MD, USA ; Cellular Imaging Section and Vascular Biology Program, Institute for Cell Engineering, The Johns Hopkins University School of Medicine Baltimore, MD, USA
| | - Galit Pelled
- The Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine Baltimore, MD, USA ; F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute Baltimore, MD, USA
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50
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Oskolkov N, Bar-Shir A, Chan KW, Song X, van Zijl PC, Bulte JW, Gilad AA, McMahon MT. Biophysical Characterization of Human Protamine-1 as a Responsive CEST MR Contrast Agent. ACS Macro Lett 2015; 4:34-38. [PMID: 25642384 PMCID: PMC4307908 DOI: 10.1021/mz500681y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 12/15/2014] [Indexed: 11/28/2022]
Abstract
![]()
The protamines are a low-molecular-weight,
arginine-rich family
of nuclear proteins that protect chromosomal DNA in germ cells by
packing it densely using electrostatic interactions. Human protamine-1
(hPRM1) has been developed as a magnetic resonance imaging (MRI) chemical
exchange saturation transfer (CEST) reporter gene, based on a sequence
that is approximately 50% arginine, which has a side chain with rapidly
exchanging protons. In this study, we have synthesized hPRM1 and determined
how its CEST MRI contrast varies as a function of pH, phosphorylation
state, and upon noncovalent interaction with nucleic acids and heparin
(as antagonist). CEST contrast was found to be highly sensitive to
phosphorylation on serine residues, intra- and intermolecular disulfide
bridge formation, and the binding of negatively charged nucleotides
and heparin. In addition, the nucleotide binding constants (Keq) for the protamines were determined through
plotting the molar concentration of heparin versus CEST contrast and
compared between hPRM1 and salmon protamine. Taken together, these
findings are important for explaining the CEST contrast of existing
arginine-rich probes as well as serving as a guideline for designing
new genetic or synthetic probes.
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Affiliation(s)
- Nikita Oskolkov
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
| | - Amnon Bar-Shir
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- Cellular
Imaging Section and Vascular Biology Program, Institute for Cell Engineering, Baltimore, Maryland United States
| | - Kannie W.Y. Chan
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
- Cellular
Imaging Section and Vascular Biology Program, Institute for Cell Engineering, Baltimore, Maryland United States
| | - Xiaolei Song
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
| | - Peter C.M. van Zijl
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
| | - Jeff W.M. Bulte
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
- Cellular
Imaging Section and Vascular Biology Program, Institute for Cell Engineering, Baltimore, Maryland United States
| | - Assaf A. Gilad
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
- Cellular
Imaging Section and Vascular Biology Program, Institute for Cell Engineering, Baltimore, Maryland United States
| | - Michael T. McMahon
- Russell
H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, Maryland United States
- F.M.
Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland United States
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