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Sadier A, Anthwal N, Krause AL, Dessalles R, Lake M, Bentolila LA, Haase R, Nieves NA, Santana SE, Sears KE. Bat teeth illuminate the diversification of mammalian tooth classes. Nat Commun 2023; 14:4687. [PMID: 37607943 PMCID: PMC10444822 DOI: 10.1038/s41467-023-40158-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 07/11/2023] [Indexed: 08/24/2023] Open
Abstract
Tooth classes are an innovation that has contributed to the evolutionary success of mammals. However, our understanding of the mechanisms by which tooth classes diversified remain limited. We use the evolutionary radiation of noctilionoid bats to show how the tooth developmental program evolved during the adaptation to new diet types. Combining morphological, developmental and mathematical modeling approaches, we demonstrate that tooth classes develop through independent developmental cascades that deviate from classical models. We show that the diversification of tooth number and size is driven by jaw growth rate modulation, explaining the rapid gain/loss of teeth in this clade. Finally, we mathematically model the successive appearance of tooth buds, supporting the hypothesis that growth acts as a key driver of the evolution of tooth number and size. Our work reveal how growth, by tinkering with reaction/diffusion processes, drives the diversification of tooth classes and other repeated structure during adaptive radiations.
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Affiliation(s)
- Alexa Sadier
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, CA, USA.
| | - Neal Anthwal
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, CA, USA
- Centre for Craniofacial and Regenerative Biology, King's College London, London, UK
| | | | - Renaud Dessalles
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, CA, USA
- Greenshield, 46 rue Saint-Antoine, 75004, Paris, France
| | - Michael Lake
- Advanced Light Microscopy and Spectroscopy Laboratory, California NanoSystems Institute, UCLA, Los Angeles, CA, 90095, USA
| | - Laurent A Bentolila
- Advanced Light Microscopy and Spectroscopy Laboratory, California NanoSystems Institute, UCLA, Los Angeles, CA, 90095, USA
| | - Robert Haase
- DFG Cluster of Excellence "Physics of Life", TU Dresden, Dresden, Germany
| | - Natalie A Nieves
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, CA, USA
| | - Sharlene E Santana
- Department of Biology and Burke Museum of Natural History and Culture, University of Washington, Seattle, WA, USA
| | - Karen E Sears
- Department of Ecology and Evolutionary Biology, University of California Los Angeles, Los Angeles, CA, USA.
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2
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Dover M, Moseley T, Biskaduros A, Paulchakrabarti M, Hwang SH, Hammock B, Choudhury B, Kaczor-Urbanowicz KE, Urbanowicz A, Morselli M, Dang J, Pellegrini M, Paul K, Bentolila LA, Fiala M. Polyunsaturated Fatty Acids Mend Macrophage Transcriptome, Glycome, and Phenotype in the Patients with Neurodegenerative Diseases, Including Alzheimer's Disease. J Alzheimers Dis 2023; 91:245-261. [PMID: 36373322 PMCID: PMC9881025 DOI: 10.3233/jad-220764] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/11/2022] [Indexed: 11/09/2022]
Abstract
BACKGROUND Macrophages of healthy subjects have a pro-resolution phenotype, upload amyloid-β (Aβ) into endosomes, and degrade Aβ, whereas macrophages of patients with Alzheimer's disease (AD) generally have a pro-inflammatory phenotype and lack energy for brain clearance of Aβ. OBJECTIVE To clarify the pathogenesis of sporadic AD and therapeutic effects of polyunsaturated fatty acids (PUFA) with vitamins B and D and antioxidants on monocyte/macrophage (MM) migration in the AD brain, MM transcripts in energy and Aβ degradation, MM glycome, and macrophage clearance of Aβ. METHODS We followed for 31.3 months (mean) ten PUFA-supplemented neurodegenerative patients: 3 with subjective cognitive impairment (SCI), 2 with mild cognitive impairment (MCI), 3 MCI/vascular cognitive impairment, 2 with dementia with Lewy bodies, and 7 non-supplemented caregivers. We examined: monocyte migration in the brain and a blood-brain barrier model by immunochemistry and electron microscopy; macrophage transcriptome by RNAseq; macrophage glycome by N-glycan profiling and LTQ-Orbitrap mass spectrometry; and macrophage phenotype and phagocytosis by immunofluorescence. RESULTS MM invade Aβ plaques, upload but do not degrade Aβ, and release Aβ into vessels, which develop cerebrovascular amyloid angiopathy (CAA); PUFA upregulate energy and Aβ degradation enzyme transcripts in macrophages; PUFA enhance sialylated N-glycans in macrophages; PUFA reduce oxidative stress and increase pro-resolution MM phenotype, mitochondrial membrane potential, and Aβ phagocytosis (p < 0.001). CONCLUSION Macrophages of SCI, MCI, and AD patients have interrelated defects in the transcriptome, glycome, Aβ phagocytosis, and Aβ degradation. PUFA mend macrophage transcriptome, enrich glycome, enhance Aβ clearance, and benefit the cognition of early-stage AD patients.
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Affiliation(s)
- Mary Dover
- Department of Molecular, Cell and Developmental Biology, UCLA School of Life Sciences, Los Angeles, CA, USA
- Department of Integrated Biology and Physiology, UCLA School of Life Sciences, Los Angeles, CA, USA
| | - Taylor Moseley
- Department of Molecular, Cell and Developmental Biology, UCLA School of Life Sciences, Los Angeles, CA, USA
| | - Adrienne Biskaduros
- Department of Molecular, Cell and Developmental Biology, UCLA School of Life Sciences, Los Angeles, CA, USA
| | | | - Sung Hee Hwang
- Department of Entomology and Nematology, and UCDavis Comprehensive Cancer Center, University of California – Davis, Davis, CA, USA
| | - Bruce Hammock
- Department of Entomology and Nematology, and UCDavis Comprehensive Cancer Center, University of California – Davis, Davis, CA, USA
| | - Biswa Choudhury
- GlycoAnalytics Core, University of California SanDiego Health Sciences, La Jolla, CA, USA
| | | | - Andrzej Urbanowicz
- Institute of Control and Computation Engineering, Warsaw University of Technology, Warsaw, Poland
| | - Marco Morselli
- Department of Molecular, Cell and Developmental Biology, UCLA School of Life Sciences, Los Angeles, CA, USA
| | - Johnny Dang
- Department of Molecular, Cell and Developmental Biology, UCLA School of Life Sciences, Los Angeles, CA, USA
| | - Matteo Pellegrini
- Department of Molecular, Cell and Developmental Biology, UCLA School of Life Sciences, Los Angeles, CA, USA
| | - Ketema Paul
- Department of Integrated Biology and Physiology, UCLA School of Life Sciences, Los Angeles, CA, USA
| | - Laurent A. Bentolila
- Advanced Light Microscopy and Spectroscopy Laboratory, California Nano Systems Institute, UCLA, Los Angeles, CA, USA
| | - Milan Fiala
- Department of Molecular, Cell and Developmental Biology, UCLA School of Life Sciences, Los Angeles, CA, USA
- Department of Integrated Biology and Physiology, UCLA School of Life Sciences, Los Angeles, CA, USA
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3
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Zhang W, Liu W, Jia L, Chen D, Chang I, Lake M, Bentolila LA, Wang CY. Targeting KDM4A epigenetically activates tumor-cell-intrinsic immunity by inducing DNA replication stress. Mol Cell 2021; 81:2148-2165.e9. [PMID: 33743195 PMCID: PMC8141018 DOI: 10.1016/j.molcel.2021.02.038] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 10/23/2020] [Accepted: 02/24/2021] [Indexed: 12/17/2022]
Abstract
Developing strategies to activate tumor-cell-intrinsic immune response is critical for improving tumor immunotherapy by exploiting tumor vulnerability. KDM4A, as a histone H3 lysine 9 trimethylation (H3K9me3) demethylase, has been found to play a critical role in squamous cell carcinoma (SCC) growth and metastasis. Here we report that KDM4A inhibition promoted heterochromatin compaction and induced DNA replication stress, which elicited antitumor immunity in SCC. Mechanistically, KDM4A inhibition promoted the formation of liquid-like HP1γ puncta on heterochromatin and stall DNA replication, which activated tumor-cell-intrinsic cGAS-STING signaling through replication-stress-induced cytosolic DNA accumulation. Moreover, KDM4A inhibition collaborated with PD1 blockade to inhibit SCC growth and metastasis by recruiting and activating CD8+ T cells. In vivo lineage tracing demonstrated that KDM4A inhibition plus PD1 blockade efficiently eliminated cancer stem cells. Altogether, our results demonstrate that targeting KDM4A can activate anti-tumor immunity and enable PD1 blockade immunotherapy by aggravating replication stress in SCC cells.
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Affiliation(s)
- Wuchang Zhang
- Jonsson Comprehensive Cancer Center, University of California, Los Angeles, Los Angeles, CA 90095, USA; Laboratory of Molecular Signaling, Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Wei Liu
- Jonsson Comprehensive Cancer Center, University of California, Los Angeles, Los Angeles, CA 90095, USA; Laboratory of Molecular Signaling, Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Lingfei Jia
- Jonsson Comprehensive Cancer Center, University of California, Los Angeles, Los Angeles, CA 90095, USA; Laboratory of Molecular Signaling, Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Demeng Chen
- Jonsson Comprehensive Cancer Center, University of California, Los Angeles, Los Angeles, CA 90095, USA; Laboratory of Molecular Signaling, Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Insoon Chang
- Jonsson Comprehensive Cancer Center, University of California, Los Angeles, Los Angeles, CA 90095, USA; Laboratory of Molecular Signaling, Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Michael Lake
- Advanced Light Microscopy and Spectroscopy Laboratory, California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Laurent A Bentolila
- Advanced Light Microscopy and Spectroscopy Laboratory, California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Cun-Yu Wang
- Jonsson Comprehensive Cancer Center, University of California, Los Angeles, Los Angeles, CA 90095, USA; Laboratory of Molecular Signaling, Division of Oral Biology and Medicine, School of Dentistry, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Bioengineering, Henry Samueli School of Engineering and Applied Science, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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Prakash R, Thareja NS, Carmichael TS, Barnhill RL, Lugassy C, Bentolila LA. Visualizing Pericyte Mimicry of Angiotropic Melanoma by Direct Labeling of the Angioarchitecture. Methods Mol Biol 2021; 2235:1-12. [PMID: 33576966 DOI: 10.1007/978-1-0716-1056-5_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Abstract
In addition to intravascular dissemination, angiotropic melanoma cells have the propensity to spread along the external surface of blood vessels in a pericytic location, or pericytic mimicry. Such continuous migration without intravasation has been termed "extravascular migratory metastasis" or EVMM. In order to visualize this mechanism of tumor propagation, we used a murine brain melanoma model utilizing green fluorescent human melanoma cells and red fluorescent lectin-tagged murine vessels. This model allows the direct microscopic visualization and mapping of the interaction of melanoma cells with the brain vasculature. In this chapter, we describe the methodology of lectin perfusion to label the entire angioarchitecture in conjunction with confocal microscopy imaging to study the pericyte mimicry of the angiotropic GFP+ melanoma cells.
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Affiliation(s)
- Roshini Prakash
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Nikita Shivani Thareja
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | - Thomas S Carmichael
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, USA
| | | | - Claire Lugassy
- Department of Translational Research, Institut Curie, Paris, France
| | - Laurent A Bentolila
- California NanoSystems Institute, University of California, Los Angeles, CA, USA.
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA.
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5
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Abstract
Multicomponent interpenetrating network hydrogels possessing enhanced mechanical stiffness compared to their individual components were prepared via physical mixing of diblock copolypeptides that assemble by either hydrophobic association or polyion complexation in aqueous media. Optical microscopy analysis of fluorescent-probe-labeled multicomponent hydrogels revealed that the diblock copolypeptide components rapidly and spontaneously self-sort to form distinct hydrogel networks that interpenetrate at micron length scales. These materials represent a class of microscale compartmentalized hydrogels composed of degradable, cell-compatible components, which possess rapid self-healing properties and independently tunable domains for downstream applications in biology and additive manufacturing.
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Cepeda C, Vergnes L, Carpo N, Schibler MJ, Bentolila LA, Karouia F, Espinosa-Jeffrey A. Human Neural Stem Cells Flown into Space Proliferate and Generate Young Neurons. Appl Sci (Basel) 2019; 9. [PMID: 34484810 PMCID: PMC8412175 DOI: 10.3390/app9194042] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Here we demonstrate that human neural stem cells (NSCs) proliferate while in space and they express specific NSC markers after being in space. NSCs displayed both higher oxygen consumption and glycolysis than ground controls. These cells also kept their ability to become young neurons. Electrophysiological recordings of space NSC-derived neurons showed immature cell membrane properties characterized by small capacitance and very high input resistance. Current injections elicited only an incipient action potential. No spontaneous synaptic events could be detected, suggesting their immature status even though most recorded cells displayed complex morphology and numerous cell processes. Ascertaining the origin of the NSCs′ increased energy requirement is of the essence in order to design effective measures to minimize health risks associated with long-duration human spaceflight missions.
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Affiliation(s)
- Carlos Cepeda
- Departments of Psychiatry, UCLA, Los Angeles, CA 90095, USA
| | - Laurent Vergnes
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Nicholas Carpo
- Departments of Psychiatry, UCLA, Los Angeles, CA 90095, USA
| | - Matthew J. Schibler
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Laurent A. Bentolila
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
- Advanced Light Microscopy/Spectroscopy, California NanoSystems Institute, University of California, Los Angeles, CA 90095, USA
| | - Fathi Karouia
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA
- NASA Ames Research Center, Space Biosciences Research Branch, Moffett Field, CA 94035, USA
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7
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Bentolila NY, Barnhill RL, Lugassy C, Bentolila LA. Intravital Imaging of Human Melanoma Cells in the Mouse Ear Skin by Two-Photon Excitation Microscopy. Methods Mol Biol 2019; 1755:223-232. [PMID: 29671273 DOI: 10.1007/978-1-4939-7724-6_15] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Noninvasive imaging of reporter gene expression by two-photon excitation (2PE) laser scanning microscopy is uniquely suited to perform dynamic and multidimensional imaging down to single-cell detection sensitivity in vivo in deep tissues. Here we used 2PE microscopy to visualize green fluorescent protein (GFP) as a reporter gene in human melanoma cells implanted into the dermis of the mouse ear skin. We first provide a step-by-step methodology to set up a 2PE imaging model of the mouse ear's skin and then apply it for the observation of the primary tumor and its associated vasculature in vivo. This approach is minimally invasive and allows repeated imaging over time and continuous visual monitoring of malignant growth within intact animals. Imaging fluorescence reporter gene expression in small living animals by 2PE provides a unique tool to investigate critical pathways and molecular events in cancer biology such as tumorigenesis and metastasis in vivo with high-spatial and temporal resolutions.
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MESH Headings
- Animals
- Cell Culture Techniques/instrumentation
- Cell Culture Techniques/methods
- Cell Line, Tumor
- Dermis/cytology
- Dermis/diagnostic imaging
- Ear, External
- Genes, Reporter/genetics
- Green Fluorescent Proteins/chemistry
- Green Fluorescent Proteins/genetics
- Humans
- Injections, Intradermal
- Intravital Microscopy/instrumentation
- Intravital Microscopy/methods
- Melanoma/diagnostic imaging
- Melanoma/pathology
- Mice
- Mice, Nude
- Microscopy, Confocal/instrumentation
- Microscopy, Confocal/methods
- Microscopy, Fluorescence, Multiphoton/instrumentation
- Microscopy, Fluorescence, Multiphoton/methods
- Skin Neoplasms/diagnostic imaging
- Skin Neoplasms/pathology
- Xenograft Model Antitumor Assays/instrumentation
- Xenograft Model Antitumor Assays/methods
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Affiliation(s)
| | - Raymond L Barnhill
- Department of Pathology, Institut Curie, University of Paris René Descartes, Paris, France
| | - Claire Lugassy
- Department of Translational Research, Institut Curie, Paris, France
| | - Laurent A Bentolila
- California NanoSystems Institute, University of California Los Angeles, Los Angeles, CA, USA.
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, USA.
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8
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Wang H, Rivenson Y, Jin Y, Wei Z, Gao R, Günaydın H, Bentolila LA, Kural C, Ozcan A. Deep learning enables cross-modality super-resolution in fluorescence microscopy. Nat Methods 2019; 16:103-110. [PMID: 30559434 PMCID: PMC7276094 DOI: 10.1038/s41592-018-0239-0] [Citation(s) in RCA: 331] [Impact Index Per Article: 66.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 11/05/2018] [Indexed: 11/09/2022]
Abstract
We present deep-learning-enabled super-resolution across different fluorescence microscopy modalities. This data-driven approach does not require numerical modeling of the imaging process or the estimation of a point-spread-function, and is based on training a generative adversarial network (GAN) to transform diffraction-limited input images into super-resolved ones. Using this framework, we improve the resolution of wide-field images acquired with low-numerical-aperture objectives, matching the resolution that is acquired using high-numerical-aperture objectives. We also demonstrate cross-modality super-resolution, transforming confocal microscopy images to match the resolution acquired with a stimulated emission depletion (STED) microscope. We further demonstrate that total internal reflection fluorescence (TIRF) microscopy images of subcellular structures within cells and tissues can be transformed to match the results obtained with a TIRF-based structured illumination microscope. The deep network rapidly outputs these super-resolved images, without any iterations or parameter search, and could serve to democratize super-resolution imaging.
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Affiliation(s)
- Hongda Wang
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA, USA
- Bioengineering Department, University of California, Los Angeles, CA, USA
- California NanoSystems Institute, University of California, Los Angeles, CA, USA
| | - Yair Rivenson
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA, USA
- Bioengineering Department, University of California, Los Angeles, CA, USA
- California NanoSystems Institute, University of California, Los Angeles, CA, USA
| | - Yiyin Jin
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA, USA
| | - Zhensong Wei
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA, USA
| | - Ronald Gao
- Computer Science Department, University of California, Los Angeles, CA, USA
| | - Harun Günaydın
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA, USA
| | - Laurent A Bentolila
- California NanoSystems Institute, University of California, Los Angeles, CA, USA
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA
| | - Comert Kural
- Department of Physics, Ohio State University, Columbus, OH, USA
- Biophysics Graduate Program, Ohio State University, Columbus, OH, USA
| | - Aydogan Ozcan
- Electrical and Computer Engineering Department, University of California, Los Angeles, CA, USA.
- Bioengineering Department, University of California, Los Angeles, CA, USA.
- California NanoSystems Institute, University of California, Los Angeles, CA, USA.
- Department of Surgery, David Geffen School of Medicine, University of California, Los Angeles, CA, USA.
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9
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Sandhu J, Li S, Fairall L, Pfisterer SG, Gurnett JE, Xiao X, Weston TA, Vashi D, Ferrari A, Orozco JL, Hartman CL, Strugatsky D, Lee SD, He C, Hong C, Jiang H, Bentolila LA, Gatta AT, Levine TP, Ferng A, Lee R, Ford DA, Young SG, Ikonen E, Schwabe JWR, Tontonoz P. Aster Proteins Facilitate Nonvesicular Plasma Membrane to ER Cholesterol Transport in Mammalian Cells. Cell 2018; 175:514-529.e20. [PMID: 30220461 DOI: 10.1016/j.cell.2018.08.033] [Citation(s) in RCA: 153] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 06/08/2018] [Accepted: 08/15/2018] [Indexed: 11/28/2022]
Abstract
The mechanisms underlying sterol transport in mammalian cells are poorly understood. In particular, how cholesterol internalized from HDL is made available to the cell for storage or modification is unknown. Here, we describe three ER-resident proteins (Aster-A, -B, -C) that bind cholesterol and facilitate its removal from the plasma membrane. The crystal structure of the central domain of Aster-A broadly resembles the sterol-binding fold of mammalian StARD proteins, but sequence differences in the Aster pocket result in a distinct mode of ligand binding. The Aster N-terminal GRAM domain binds phosphatidylserine and mediates Aster recruitment to plasma membrane-ER contact sites in response to cholesterol accumulation in the plasma membrane. Mice lacking Aster-B are deficient in adrenal cholesterol ester storage and steroidogenesis because of an inability to transport cholesterol from SR-BI to the ER. These findings identify a nonvesicular pathway for plasma membrane to ER sterol trafficking in mammals.
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Affiliation(s)
- Jaspreet Sandhu
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Shiqian Li
- Department of Anatomy and Research Programs Unit, Faculty of Medicine, University of Helsinki, Helsinki 00290, Finland; Minerva Foundation Institute for Medical Research, Helsinki 00290, Finland
| | - Louise Fairall
- Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 7RH, UK
| | - Simon G Pfisterer
- Department of Anatomy and Research Programs Unit, Faculty of Medicine, University of Helsinki, Helsinki 00290, Finland; Minerva Foundation Institute for Medical Research, Helsinki 00290, Finland
| | - Jennifer E Gurnett
- Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 7RH, UK
| | - Xu Xiao
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Thomas A Weston
- Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Dipti Vashi
- Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 7RH, UK
| | - Alessandra Ferrari
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Jose L Orozco
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Celine L Hartman
- Edward A. Doisy Department of Biochemistry and Molecular Biology, and Center for Cardiovascular Research, Saint Louis University School of Medicine, St. Louis, MO 63104, USA
| | - David Strugatsky
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Stephen D Lee
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Cuiwen He
- Department of Medicine, Division of Cardiology, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Cynthia Hong
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Haibo Jiang
- Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Perth 6009, Australia
| | - Laurent A Bentolila
- California NanoSystems Institute, University of California, Los Angeles, CA 90095, USA
| | - Alberto T Gatta
- Department of Cell Biology, UCL Institute of Ophthalmology, London, UK
| | - Tim P Levine
- Department of Cell Biology, UCL Institute of Ophthalmology, London, UK
| | - Annie Ferng
- Ionis Pharmaceuticals, Carlsbad, CA 92008, USA
| | - Richard Lee
- Ionis Pharmaceuticals, Carlsbad, CA 92008, USA
| | - David A Ford
- Edward A. Doisy Department of Biochemistry and Molecular Biology, and Center for Cardiovascular Research, Saint Louis University School of Medicine, St. Louis, MO 63104, USA
| | - Stephen G Young
- Department of Medicine, Division of Cardiology, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Elina Ikonen
- Department of Anatomy and Research Programs Unit, Faculty of Medicine, University of Helsinki, Helsinki 00290, Finland; Minerva Foundation Institute for Medical Research, Helsinki 00290, Finland
| | - John W R Schwabe
- Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 7RH, UK
| | - Peter Tontonoz
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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10
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Fornabaio G, Barnhill RL, Lugassy C, Bentolila LA, Cassoux N, Roman-Roman S, Alsafadi S, Del Bene F. Angiotropism and extravascular migratory metastasis in cutaneous and uveal melanoma progression in a zebrafish model. Sci Rep 2018; 8:10448. [PMID: 29992995 PMCID: PMC6041265 DOI: 10.1038/s41598-018-28515-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 06/21/2018] [Indexed: 02/01/2023] Open
Abstract
Cutaneous melanoma is a highly aggressive cancer with a propensity for distant metastasis to various organs. In contrast, melanoma arising in pigmented uveal layers of the eye metastasizes mostly in the liver. The mechanisms of these metastases, which are ultimately resistant to therapy, are still unclear. Metastasis via intravascular dissemination of tumour cells is widely accepted as a central paradigm. However, we have previously described an alternative mode of tumour dissemination, extravascular migratory metastasis, based on clinical and experimental data. This mechanism is characterised by the interaction of cancer cells with the abluminal vascular surface, which defines angiotropism. Here, we employed our 3D co-culture approach to monitor cutaneous and uveal human melanoma cells dynamics in presence of vascular tubules. Using time-lapse microscopy, we evaluated angiotropism, the migration of tumour cells along vascular tubules and the morphological changes occurring during these processes. Cutaneous and uveal melanoma cells were injected in zebrafish embryos in order to develop xenografts. Employing in vivo imaging coupled with 3D reconstruction, we monitored the interactions between cancer cells and the external surface of zebrafish vessels. Overall, our results indicate that cutaneous and uveal melanoma cells spread similarly along the abluminal vascular surfaces, in vitro and in vivo.
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Affiliation(s)
- Giulia Fornabaio
- Institut Curie, PSL Research University, Inserm U934, CNRS UMR315, F-75005, Paris, France
- Institut Curie, PSL Research University, Department of Translational Research, F-75005, Paris, France
- Sorbonne Universités, UPMC University Paris 6, CNRS UMR 3215, INSERM U934, F-75005, Paris, France
| | - Raymond L Barnhill
- Institut Curie, PSL Research University, Department of Pathology, F-75005, Paris, France
- Faculty of Medicine, University of Paris René Descartes, F-75006, Paris, France
| | - Claire Lugassy
- Institut Curie, PSL Research University, Department of Translational Research, F-75005, Paris, France
| | - Laurent A Bentolila
- California NanoSystems Institute, Los Angeles, CA, 90095, USA
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, 90095, USA
| | - Nathalie Cassoux
- Faculty of Medicine, University of Paris René Descartes, F-75006, Paris, France
- Institut Curie, PSL Research University, Department of Ophthalmology, F-75005, Paris, France
| | - Sergio Roman-Roman
- Institut Curie, PSL Research University, Department of Translational Research, F-75005, Paris, France
| | - Samar Alsafadi
- Institut Curie, PSL Research University, Department of Translational Research, F-75005, Paris, France.
| | - Filippo Del Bene
- Institut Curie, PSL Research University, Inserm U934, CNRS UMR315, F-75005, Paris, France.
- Institut Curie, PSL Research University, Department of Translational Research, F-75005, Paris, France.
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11
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Reinig MR, Novak SW, Tao X, Bentolila LA, Roberts DG, MacKenzie-Graham A, Godshalk SE, Raven MA, Knowles DW, Kubby J. Enhancing image quality in cleared tissue with adaptive optics. J Biomed Opt 2016; 21:121508. [PMID: 27735018 PMCID: PMC5997003 DOI: 10.1117/1.jbo.21.12.121508] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 09/19/2016] [Indexed: 06/06/2023]
Abstract
Our ability to see fine detail at depth in tissues is limited by scattering and other refractive characteristics of the tissue. For fixed tissue, we can limit scattering with a variety of clearing protocols. This allows us to see deeper but not necessarily clearer. Refractive aberrations caused by the bulk index of refraction of the tissue and its variations continue to limit our ability to see fine detail. Refractive aberrations are made up of spherical and other Zernike modes, which can be significant at depth. Spherical aberration that is common across the imaging field can be corrected using an objective correcting collar, although this can require manual intervention. Other aberrations may vary across the imaging field and can only be effectively corrected using adaptive optics. Adaptive optics can also correct other aberrations simultaneously with the spherical aberration, eliminating manual intervention and speeding imaging. We use an adaptive optics two-photon microscope to examine the impact of the spherical and higher order aberrations on imaging and contrast the effect of compensating only for spherical aberration against compensating for the first 22 Zernike aberrations in two tissue types. Increase in image intensity by 1.6× and reduction of root mean square error by 3× are demonstrated.
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Affiliation(s)
- Marc R. Reinig
- University of California Santa Cruz, W.M. Keck Center for Adaptive Optical Microscopy, Baskin Engineering, 1154 High Street, Santa Cruz, California 95064, United States
| | - Samuel W. Novak
- University of California Santa Cruz, W.M. Keck Center for Adaptive Optical Microscopy, Baskin Engineering, 1154 High Street, Santa Cruz, California 95064, United States
| | - Xiaodong Tao
- University of California Santa Cruz, W.M. Keck Center for Adaptive Optical Microscopy, Baskin Engineering, 1154 High Street, Santa Cruz, California 95064, United States
| | - Laurent A. Bentolila
- University of California, California Nanosystems Institute, Advanced Light Microscopy/Spectroscopy Laboratory, 570 Westwood Plaza, Building 114, Los Angeles, California 90095, United States
| | - Dustin G. Roberts
- UCLA Brain Mapping Center, 660 Charles E. Young Drive South, Los Angeles, California 90095, United States
| | - Allan MacKenzie-Graham
- UCLA Neurology, 710 Westwood Plaza, PO Box 951769, 4256 Los Angeles, California 90095-1769, United States
| | - Sirie E. Godshalk
- University of California, Neuroscience Research Institute, Microscopy Facility, 3087 Calle Rosales, Santa Barbara, California 93105, United States
| | - Mary A. Raven
- UCSB’s Office of Technology and Industry Alliances, 342 Lagoon Road, Mail Code 2055, Santa Barbara, California 93106-2055, United States
| | - David W. Knowles
- Life Sciences Division, Berkeley Drosophila Transcription Network Project, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
| | - Joel Kubby
- University of California Santa Cruz, W.M. Keck Center for Adaptive Optical Microscopy, Baskin Engineering, 1154 High Street, Santa Cruz, California 95064, United States
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12
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Bentolila LA, Prakash R, Mihic-Probst D, Wadehra M, Kleinman HK, Carmichael TS, Péault B, Barnhill RL, Lugassy C. Imaging of Angiotropism/Vascular Co-Option in a Murine Model of Brain Melanoma: Implications for Melanoma Progression along Extravascular Pathways. Sci Rep 2016; 6:23834. [PMID: 27048955 PMCID: PMC4822155 DOI: 10.1038/srep23834] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 02/15/2016] [Indexed: 02/01/2023] Open
Abstract
Angiotropism/pericytic mimicry and vascular co-option involve tumor cell interactions with the abluminal vascular surface. These two phenomena may be closely related. However, investigations of the two processes have developed in an independent fashion and different explanations offered as to their biological nature. Angiotropism describes the propensity of tumor cells to spread distantly via continuous migration along abluminal vascular surfaces, or extravascular migratory metastasis (EVMM). Vascular co-option has been proposed as an alternative mechanism by which tumors cells may gain access to a blood supply. We have used a murine brain melanoma model to analyze the interactions of GFP human melanoma cells injected into the mouse brain with red fluorescent lectin-labeled microvascular channels. Results have shown a striking spread of melanoma cells along preexisting microvascular channels and features of both vascular co-option and angiotropism/pericytic mimicry. This study has also documented the perivascular expression of Serpin B2 by angiotropic melanoma cells in the murine brain and in human melanoma brain metastases. Our findings suggest that vascular co-option and angiotropism/pericytic mimicry are closely related if not identical processes. Further studies are needed in order to establish whether EVMM is an alternative form of cancer metastasis in addition to intravascular cancer dissemination.
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Affiliation(s)
- Laurent A. Bentolila
- California NanoSystems Institute, Los Angeles, CA, 90095 USA
- Department of Chemistry and Biochemistry University of California, Los Angeles, CA, 90095 USA
| | - Roshini Prakash
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095 USA
| | - Daniela Mihic-Probst
- Institute of Surgical Pathology, University Hospital Zurich, 8091 Zurich, Switzerland
| | - Madhuri Wadehra
- Department of Pathology and Laboratory Medicine and Jonsson Comprehensive Cancer Center, David Geffen School of Medicine at University of California Los Angeles UCLA, Los Angeles, CA, USA
| | | | - Thomas S. Carmichael
- Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, CA, 90095 USA
| | - Bruno Péault
- Orthopedic Hospital Research Center and Broad Stem Cell Center, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA, USA
- MRC Center for Regenerative Medicine and BHF Center for Cardiovascular Science, Queens Medical Research Institute University of Edinburgh, Edinburgh, UK
| | - Raymond L. Barnhill
- Department of Pathology, Institut Curie, and University of Paris Réne Descartes, Paris, France
| | - Claire Lugassy
- Department of Translational Research, Institut Curie, Paris, France
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13
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Sonn GA, Behesnilian AS, Jiang ZK, Zettlitz KA, Lepin EJ, Bentolila LA, Knowles SM, Lawrence D, Wu AM, Reiter RE. Fluorescent Image-Guided Surgery with an Anti-Prostate Stem Cell Antigen (PSCA) Diabody Enables Targeted Resection of Mouse Prostate Cancer Xenografts in Real Time. Clin Cancer Res 2015; 22:1403-12. [PMID: 26490315 DOI: 10.1158/1078-0432.ccr-15-0503] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 10/06/2015] [Indexed: 01/13/2023]
Abstract
PURPOSE The inability to visualize cancer during prostatectomy contributes to positive margins, cancer recurrence, and surgical side effects. A molecularly targeted fluorescent probe offers the potential for real-time intraoperative imaging. The goal of this study was to develop a probe for image-guided prostate cancer surgery. EXPERIMENTAL DESIGN An antibody fragment (cys-diabody, cDb) against prostate stem cell antigen (PSCA) was conjugated to a far-red fluorophore, Cy5. The integrity and binding of the probe to PSCA was confirmed by gel electrophoresis, size exclusion, and flow cytometry, respectively. Subcutaneous models of PSCA-expressing xenografts were used to assess the biodistribution and in vivo kinetics, whereas an invasive intramuscular model was utilized to explore the performance of Cy5-cDb-mediated fluorescence guidance in representative surgical scenarios. Finally, a prospective, randomized study comparing surgical resection with and without fluorescent guidance was performed to determine whether this probe could reduce the incidence of positive margins. RESULTS Cy5-cDb demonstrated excellent purity, stability, and specific binding to PSCA. In vivo imaging showed maximal signal-to-background ratios at 6 hours. In mice carrying PSCA(+) and negative (-) dual xenografts, the mean fluorescence ratio of PSCA(+/-) tumors was 4.4:1. In surgical resection experiments, residual tumors <1 mm that were missed on white light surgery were identified and resected using fluorescence guidance, which reduced the incidence of positive surgical margins (0/8) compared with white light surgery alone (7/7). CONCLUSIONS Fluorescently labeled cDb enables real-time in vivo imaging of prostate cancer xenografts in mice, and facilitates more complete tumor removal than conventional white light surgery alone.
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Affiliation(s)
- Geoffrey A Sonn
- Department of Urology, University of California, Los Angeles, California
| | | | - Ziyue Karen Jiang
- Department of Urology, University of California, Los Angeles, California
| | - Kirstin A Zettlitz
- Molecular and Medical Pharmacology, University of California, Los Angeles, California. Crump Institute for Molecular Imaging, University of California, Los Angeles, California
| | - Eric J Lepin
- Molecular and Medical Pharmacology, University of California, Los Angeles, California. Crump Institute for Molecular Imaging, University of California, Los Angeles, California
| | - Laurent A Bentolila
- Deparment of Chemistry and Biochemistry, University of California, Los Angeles, California. California NanoSystems Institute, University of California, Los Angeles, California
| | - Scott M Knowles
- Molecular and Medical Pharmacology, University of California, Los Angeles, California. Crump Institute for Molecular Imaging, University of California, Los Angeles, California
| | - Daniel Lawrence
- Molecular and Medical Pharmacology, University of California, Los Angeles, California
| | - Anna M Wu
- Molecular and Medical Pharmacology, University of California, Los Angeles, California. Crump Institute for Molecular Imaging, University of California, Los Angeles, California
| | - Robert E Reiter
- Department of Urology, University of California, Los Angeles, California.
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14
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Kisalu NK, Langousis G, Bentolila LA, Ralston KS, Hill KL. Mouse infection and pathogenesis by Trypanosoma brucei motility mutants. Cell Microbiol 2014; 16:912-24. [PMID: 24286532 DOI: 10.1111/cmi.12244] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 11/14/2013] [Accepted: 11/15/2013] [Indexed: 12/27/2022]
Abstract
The flagellum of Trypanosoma brucei is an essential and multifunctional organelle that drives parasite motility and is receiving increased attention as a potential drug target. In the mammalian host, parasite motility is suspected to contribute to infection and disease pathogenesis. However, it has not been possible to test this hypothesis owing to lack of motility mutants that are viable in the bloodstream life cycle stage that infects the mammalian host. We recently identified a bloodstream-form motility mutant in 427-derived T. brucei in which point mutations in the LC1 dynein subunit disrupt propulsive motility but do not affect viability. These mutants have an actively beating flagellum, but cannot translocate. Here we demonstrate that the LC1 point mutant fails to show enhanced cell motility upon increasing viscosity of the surrounding medium, which is a hallmark of wild type T. brucei, thus indicating that motility of the mutant is fundamentally altered compared with wild type cells. We next used the LC1 point mutant to assess the influence of trypanosome motility on infection in mice. Wesurprisingly found that disrupting parasite motility has no discernible effect on T. brucei bloodstream infection. Infection time-course, maximum parasitaemia, number of waves of parasitaemia, clinical features and disease outcome are indistinguishable between motility mutant and control parasites. Our studies provide an important step toward understanding the contribution of parasite motility to infection and a foundation for future investigations of T. brucei interaction with the mammalian host.
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Affiliation(s)
- Neville K Kisalu
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, CA, 90095, USA
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15
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Mittal N, Roberts K, Pal K, Bentolila LA, Fultz E, Minasyan A, Cahill C, Pradhan A, Conner D, DeFea K, Evans C, Walwyn W. Select G-protein-coupled receptors modulate agonist-induced signaling via a ROCK, LIMK, and β-arrestin 1 pathway. Cell Rep 2013; 5:1010-21. [PMID: 24239352 DOI: 10.1016/j.celrep.2013.10.015] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 09/04/2013] [Accepted: 10/07/2013] [Indexed: 12/12/2022] Open
Abstract
G-protein-coupled receptors (GPCRs) are typically present in a basal, inactive state but, when bound to an agonist, activate downstream signaling cascades. In studying arrestin regulation of opioid receptors in dorsal root ganglia (DRG) neurons, we find that agonists of delta opioid receptors (δORs) activate cofilin through Rho-associated coiled-coil-containing protein kinase (ROCK), LIM domain kinase (LIMK), and β-arrestin 1 (β-arr1) to regulate actin polymerization. This controls receptor function, as assessed by agonist-induced inhibition of voltage-dependent Ca(2+) channels in DRGs. Agonists of opioid-receptor-like receptors (ORL1) similarly influence the function of this receptor through ROCK, LIMK, and β-arr1. Functional evidence of this cascade was demonstrated in vivo, where the behavioral effects of δOR or ORL1 agonists were enhanced in the absence of β-arr1 or prevented by inhibiting ROCK. This pathway allows δOR and ORL1 agonists to rapidly regulate receptor function.
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Affiliation(s)
- Nitish Mittal
- Department of Psychiatry and Biobehavioral Sciences, Stefan Hatos Center for Neuropharmacology, Semel Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
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16
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Wei Q, Qi H, Luo W, Tseng D, Ki SJ, Wan Z, Göröcs Z, Bentolila LA, Wu TT, Sun R, Ozcan A. Fluorescent imaging of single nanoparticles and viruses on a smart phone. ACS Nano 2013; 7:9147-55. [PMID: 24016065 PMCID: PMC3951925 DOI: 10.1021/nn4037706] [Citation(s) in RCA: 265] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Optical imaging of nanoscale objects, whether it is based on scattering or fluorescence, is a challenging task due to reduced detection signal-to-noise ratio and contrast at subwavelength dimensions. Here, we report a field-portable fluorescence microscopy platform installed on a smart phone for imaging of individual nanoparticles as well as viruses using a lightweight and compact opto-mechanical attachment to the existing camera module of the cell phone. This hand-held fluorescent imaging device utilizes (i) a compact 450 nm laser diode that creates oblique excitation on the sample plane with an incidence angle of ~75°, (ii) a long-pass thin-film interference filter to reject the scattered excitation light, (iii) an external lens creating 2× optical magnification, and (iv) a translation stage for focus adjustment. We tested the imaging performance of this smart-phone-enabled microscopy platform by detecting isolated 100 nm fluorescent particles as well as individual human cytomegaloviruses that are fluorescently labeled. The size of each detected nano-object on the cell phone platform was validated using scanning electron microscopy images of the same samples. This field-portable fluorescence microscopy attachment to the cell phone, weighing only ~186 g, could be used for specific and sensitive imaging of subwavelength objects including various bacteria and viruses and, therefore, could provide a valuable platform for the practice of nanotechnology in field settings and for conducting viral load measurements and other biomedical tests even in remote and resource-limited environments.
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Affiliation(s)
- Qingshan Wei
- Electrical Engineering Department, University of California, Los Angeles (UCLA), California 90095, United States
- Bioengineering Department, University of California, Los Angeles (UCLA), California 90095, United States
- California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), California 90095, United States
| | - Hangfei Qi
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles (UCLA), California 90095, United States
| | - Wei Luo
- Electrical Engineering Department, University of California, Los Angeles (UCLA), California 90095, United States
| | - Derek Tseng
- Electrical Engineering Department, University of California, Los Angeles (UCLA), California 90095, United States
| | - So Jung Ki
- Department of Chemistry and Biochemistry, University of California, Los Angeles (UCLA), California 90095, United States
| | - Zhe Wan
- Electrical Engineering Department, University of California, Los Angeles (UCLA), California 90095, United States
| | - Zoltán Göröcs
- Electrical Engineering Department, University of California, Los Angeles (UCLA), California 90095, United States
- Bioengineering Department, University of California, Los Angeles (UCLA), California 90095, United States
| | - Laurent A. Bentolila
- Department of Chemistry and Biochemistry, University of California, Los Angeles (UCLA), California 90095, United States
| | - Ting-Ting Wu
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles (UCLA), California 90095, United States
| | - Ren Sun
- California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), California 90095, United States
- Department of Molecular and Medical Pharmacology, University of California, Los Angeles (UCLA), California 90095, United States
| | - Aydogan Ozcan
- Electrical Engineering Department, University of California, Los Angeles (UCLA), California 90095, United States
- Bioengineering Department, University of California, Los Angeles (UCLA), California 90095, United States
- California NanoSystems Institute (CNSI), University of California, Los Angeles (UCLA), California 90095, United States
- Address correspondence to:
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17
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Wend P, Runke S, Wend K, Anchondo B, Yesayan M, Jardon M, Hardie N, Loddenkemper C, Ulasov I, Lesniak MS, Wolsky R, Bentolila LA, Grant SG, Elashoff D, Lehr S, Latimer JJ, Bose S, Sattar H, Krum SA, Miranda-Carboni GA. WNT10B/β-catenin signalling induces HMGA2 and proliferation in metastatic triple-negative breast cancer. EMBO Mol Med 2013; 5:264-79. [PMID: 23307470 PMCID: PMC3569642 DOI: 10.1002/emmm.201201320] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 11/13/2012] [Accepted: 11/14/2012] [Indexed: 12/22/2022] Open
Abstract
Wnt/β-catenin signalling has been suggested to be active in basal-like breast cancer. However, in highly aggressive metastatic triple-negative breast cancers (TNBC) the role of β-catenin and the underlying mechanism(s) for the aggressiveness of TNBC remain unknown. We illustrate that WNT10B induces transcriptionally active β-catenin in human TNBC and predicts survival-outcome of patients with both TNBC and basal-like tumours. We provide evidence that transgenic murine Wnt10b-driven tumours are devoid of ERα, PR and HER2 expression and can model human TNBC. Importantly, HMGA2 is specifically expressed during early stages of embryonic mammogenesis and absent when WNT10B expression is lost, suggesting a developmentally conserved mode of action. Mechanistically, ChIP analysis uncovered that WNT10B activates canonical β-catenin signalling leading to up-regulation of HMGA2. Treatment of mouse and human triple-negative tumour cells with two Wnt/β-catenin pathway modulators or siRNA to HMGA2 decreases HMGA2 levels and proliferation. We demonstrate that WNT10B has epistatic activity on HMGA2, which is necessary and sufficient for proliferation of TNBC cells. Furthermore, HMGA2 expression predicts relapse-free-survival and metastasis in TNBC patients.
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Affiliation(s)
- Peter Wend
- Department of Obstetrics and Gynecology, David Geffen School of Medicine at UCLA, Jonsson Comprehensive Cancer Center, Los Angeles, CA, USA
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18
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Mitchell-Jordan S, Chen H, Franklin S, Stefani E, Bentolila LA, Vondriska TM. Features of endogenous cardiomyocyte chromatin revealed by super-resolution STED microscopy. J Mol Cell Cardiol 2012; 53:552-8. [PMID: 22846883 DOI: 10.1016/j.yjmcc.2012.07.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 07/06/2012] [Accepted: 07/19/2012] [Indexed: 11/30/2022]
Abstract
Despite the extensive knowledge of the functional unit of chromatin-the nucleosome-for which structural information exists at the atomic level, little is known about the endogenous structure of eukaryotic genomes. Chromosomal capture techniques and genome-wide chromatin immunoprecipitation and next generation sequencing have provided complementary insight into global features of chromatin structure, but these methods do not directly measure structural features of the genome in situ. This lack of insight is particularly troublesome in terminally differentiated cells which must reorganize their genomes for large scale gene expression changes in the absence of cell division. For example, cardiomyocytes, which are fully committed and reside in interphase, are capable of massive gene expression changes in response to physiological stimuli, but the global changes in chromatin structure that enable such transcriptional changes are unknown. The present study addressed this problem utilizing super-resolution stimulated emission depletion (STED) microscopy to directly measure chromatin features in mammalian cells. We demonstrate that immunolabeling of histone H3 coupled with STED imaging reveals chromatin domains on a scale of 40-70 nm, several folds better than the resolution of conventional confocal microscopy. An analytical workflow is established to detect changes in chromatin structure following acute stimuli and used to investigate rearrangements in cardiomyocyte genomes following agonists that induce cellular hypertrophy. This approach is readily adaptable to investigation of other nuclear features using a similar antibody-based labeling technique and enables direct measurements of chromatin domain changes in response to physiological stimuli.
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Affiliation(s)
- Scherise Mitchell-Jordan
- Department of Anesthesiology, David Geffen School of Medicine, University of California, Los Angeles, USA
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19
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Gu Z, Zhao M, Sheng Y, Bentolila LA, Tang Y. Detection of mercury ion by infrared fluorescent protein and its hydrogel-based paper assay. Anal Chem 2011; 83:2324-9. [PMID: 21323346 DOI: 10.1021/ac103236g] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mercury is a highly hazardous and widespread pollutant with bioaccumulative properties. Novel approaches that meet the criteria of desired selectivity, high sensitivity, good biocompatibility, and low background interference in natural settings are continuously being explored. We herein describe a new strategy utilizing the combination of infrared fluorescent protein (IFP) and its chromophore as an infrared fluorescence probe for mercury ion (Hg(II)) detection. Hg(II) has been validated to have specific binding affinity to a cysteine residue (C24) of IFP, thereby inhibiting the conjugation of IFP chromophore biliverdin (BV) to C24 and "turning off" the infrared emission of IFP. The IFP/BV sensor has high selectivity toward Hg(II) among other metal ions over a broad pH range. The in vitro detection limit was determined to be less than 50 nM. As a genetically encoded probe, we demonstrate the IFP/BV sensor can serve as a tool to detect Hg(II) in living organisms or tissues. Moreover, we have exploited a protein-agarose hydrogel-based paper assay to immobilize IFP for detection of Hg(II) in a portable and robust fashion.
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Affiliation(s)
- Zhen Gu
- Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, Los Angeles, California 90095, United States.
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20
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Yang J, Kickhoefer VA, Ng BC, Gopal A, Bentolila LA, John S, Tolbert SH, Rome LH. Vaults are dynamically unconstrained cytoplasmic nanoparticles capable of half vault exchange. ACS Nano 2010; 4:7229-7240. [PMID: 21121616 PMCID: PMC3020078 DOI: 10.1021/nn102051r] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Vaults are naturally occurring ribonucleoprotein particles with an enormous interior volume, large enough to encapsulate hundreds of proteins. They are highly conserved and are present in nearly all eukaryotic cells ranging from 10(4) to 10(7) particles per cell. Recombinant vaults can be produced in vitro and engineered to allow cell targeting and protein packaging. These nanometer-sized particles have many desirable characteristics that may give them advantages for use as drug delivery vehicles. Using photoactivatable green fluorescent protein (PAGFP) labeled vaults, we demonstrate that the particles rapidly diffuse throughout the cytoplasm following single pixel photoactivation in live cells. Their in vivo movement remained relatively unchanged despite exposure to a variety of cellular stresses, suggesting that vaults are largely unconstrained in the cytoplasm. Fluorescence resonance energy transfer (FRET) was observed from polyethylene glycol (PEG) fused hybrid cells that expressed either CFP or YFP labeled vaults, indicating that vaults can exchange major vault protein (MVP) subunits in vivo. Investigation into the mechanism of this exchange in vitro using recombinant vaults demonstrated that they were capable of rapidly separating at the particle waist and reassembling back into whole vaults, supporting a half vault exchange mechanism. This data suggests a means whereby vaults can functionally interact with their cellular environment and deliver materials packaged within their interior.
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Affiliation(s)
- Jian Yang
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, Los Angeles, California, USA 90095
| | - Valerie A. Kickhoefer
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, Los Angeles, California, USA 90095
| | - Benny C. Ng
- Department of Chemistry and Biochemistry, David Geffen School of Medicine at UCLA, Los Angeles, California, USA 90095
| | - Ajaykumar Gopal
- Department of Chemistry and Biochemistry, David Geffen School of Medicine at UCLA, Los Angeles, California, USA 90095
| | - Laurent A. Bentolila
- Department of Chemistry and Biochemistry, David Geffen School of Medicine at UCLA, Los Angeles, California, USA 90095
- California NanoSystems Institute at UCLA, Los Angeles, California, USA 90095
| | - Scott John
- Medicine and Cardiovascular Research Laboratories, David Geffen School of Medicine at UCLA, Los Angeles, California, USA 90095
| | - Sarah H. Tolbert
- Department of Chemistry and Biochemistry, David Geffen School of Medicine at UCLA, Los Angeles, California, USA 90095
- California NanoSystems Institute at UCLA, Los Angeles, California, USA 90095
| | - Leonard H. Rome
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, Los Angeles, California, USA 90095
- California NanoSystems Institute at UCLA, Los Angeles, California, USA 90095
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21
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Coffinier C, Jung HJ, Li Z, Nobumori C, Yun UJ, Farber EA, Davies BS, Weinstein MM, Yang SH, Lammerding J, Farahani JN, Bentolila LA, Fong LG, Young SG. Direct synthesis of lamin A, bypassing prelamin a processing, causes misshapen nuclei in fibroblasts but no detectable pathology in mice. J Biol Chem 2010; 285:20818-26. [PMID: 20439468 DOI: 10.1074/jbc.m110.128835] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Lamin A, a key component of the nuclear lamina, is generated from prelamin A by four post-translational processing steps: farnesylation, endoproteolytic release of the last three amino acids of the protein, methylation of the C-terminal farnesylcysteine, and finally, endoproteolytic release of the last 15 amino acids of the protein (including the farnesylcysteine methyl ester). The last cleavage step, mediated by ZMPSTE24, releases mature lamin A. This processing scheme has been conserved through vertebrate evolution and is widely assumed to be crucial for targeting lamin A to the nuclear envelope. However, its physiologic importance has never been tested. To address this issue, we created mice with a "mature lamin A-only" allele (Lmna(LAO)), which contains a stop codon immediately after the last codon of mature lamin A. Thus, Lmna(LAO/LAO) mice synthesize mature lamin A directly, bypassing prelamin A synthesis and processing. The levels of mature lamin A in Lmna(LAO/LAO) mice were indistinguishable from those in "prelamin A-only" mice (Lmna(PLAO/PLAO)), where all of the lamin A is produced from prelamin A. Lmna(LAO/LAO) exhibited normal body weights and had no detectable disease phenotypes. A higher frequency of nuclear blebs was observed in Lmna(LAO/LAO) embryonic fibroblasts; however, the mature lamin A in the tissues of Lmna(LAO/LAO) mice was positioned normally at the nuclear rim. We conclude that prelamin A processing is dispensable in mice and that direct synthesis of mature lamin A has little if any effect on the targeting of lamin A to the nuclear rim in mouse tissues.
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Affiliation(s)
- Catherine Coffinier
- Department of Medicine, University of California, Los Angeles, CA 90095, USA.
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Abstract
Nanotechnology is poised to transform research, prevention, and treatment of cancer through the development of novel diagnostic imaging methods and targeted therapies. In particular, the use of nanoparticles for imaging has gained considerable momentum in recent years. This review focuses on the growing contribution of quantum dots (QDs) for in vivo imaging in small-animal models. Fluorescent QDs, which are small nanocrystals (1-10 nm) made of inorganic semiconductor materials, possess several unique optical properties best suited for in vivo imaging. Because of quantum confinement effects, the emission color of QDs can be precisely tuned by size from the ultraviolet to the near-infrared. QDs are extremely bright and photostable. They are also characterized by a wide absorption band and a narrow emission band, which makes them ideal for multiplexing. Finally, the large surface area of QDs permits the assembly of various contrast agents to design multimodality imaging probes. To date, biocompatible QD conjugates have been used successfully for sentinel lymph node mapping, tumor targeting, tumor angiogenesis imaging, and metastatic cell tracking. Here we consider these novel breakthroughs in light of their potential clinical applications and discuss how QDs might offer a suitable platform to unite disparate imaging modalities and provide information along a continuum of length scales.
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Affiliation(s)
- Laurent A Bentolila
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, California, USA.
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Schipper ML, Iyer G, Koh AL, Cheng Z, Ebenstein Y, Aharoni A, Keren S, Bentolila LA, Li J, Rao J, Chen X, Banin U, Wu AM, Sinclair R, Weiss S, Gambhir SS. Particle size, surface coating, and PEGylation influence the biodistribution of quantum dots in living mice. Small 2009; 5:126-34. [PMID: 19051182 PMCID: PMC3084659 DOI: 10.1002/smll.200800003] [Citation(s) in RCA: 309] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
This study evaluates the influence of particle size, PEGylation, and surface coating on the quantitative biodistribution of near-infrared-emitting quantum dots (QDs) in mice. Polymer- or peptide-coated 64Cu-labeled QDs 2 or 12 nm in diameter, with or without polyethylene glycol (PEG) of molecular weight 2000, are studied by serial micropositron emission tomography imaging and region-of-interest analysis, as well as transmission electron microscopy and inductively coupled plasma mass spectrometry. PEGylation and peptide coating slow QD uptake into the organs of the reticuloendothelial system (RES), liver and spleen, by a factor of 6-9 and 2-3, respectively. Small particles are in part renally excreted. Peptide-coated particles are cleared from liver faster than physical decay alone would suggest. Renal excretion of small QDs and slowing of RES clearance by PEGylation or peptide surface coating are encouraging steps toward the use of modified QDs for imaging living subjects.
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Affiliation(s)
- Meike L. Schipper
- Molecular Imaging Program at Stanford (MIPS), Departments of Radiology and Bioengineering, Bio-X Program, Stanford University, 318 Campus Drive, Palo Alto, CA 94305-5427 (USA)
| | - Gopal Iyer
- California NanoSystems Institute (CNSI) and Department of Chemistry and Biochemistry, UCLA School of Medicine, Los Angeles, CA 90005-1770 (USA)
| | - Ai Leen Koh
- Stanford Nanocharacterization Laboratory, Department of Materials Science and Engineering, Stanford University, Palo Alto, CA 94305-5427 (USA)
| | - Zhen Cheng
- Molecular Imaging Program at Stanford (MIPS), Departments of Radiology and Bioengineering, Bio-X Program, Stanford University, 318 Campus Drive, Palo Alto, CA 94305-5427 (USA)
| | - Yuval Ebenstein
- California NanoSystems Institute (CNSI) and Department of Chemistry and Biochemistry, UCLA School of Medicine, Los Angeles, CA 90005-1770 (USA)
| | - Assaf Aharoni
- Department of Physical Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Givat Ram, Jerusalem (Israel)
| | - Shay Keren
- Molecular Imaging Program at Stanford (MIPS), Departments of Radiology and Bioengineering, Bio-X Program, Stanford University, 318 Campus Drive, Palo Alto, CA 94305-5427 (USA)
| | - Laurent A. Bentolila
- California NanoSystems Institute (CNSI) and Department of Chemistry and Biochemistry, UCLA School of Medicine, Los Angeles, CA 90005-1770 (USA)
| | - Jianquing Li
- California NanoSystems Institute (CNSI) and Department of Chemistry and Biochemistry, UCLA School of Medicine, Los Angeles, CA 90005-1770 (USA)
| | - Jianghong Rao
- Molecular Imaging Program at Stanford (MIPS), Departments of Radiology and Bioengineering, Bio-X Program, Stanford University, 318 Campus Drive, Palo Alto, CA 94305-5427 (USA)
| | - Xiaoyuan Chen
- Molecular Imaging Program at Stanford (MIPS), Departments of Radiology and Bioengineering, Bio-X Program, Stanford University, 318 Campus Drive, Palo Alto, CA 94305-5427 (USA)
| | - Uri Banin
- Department of Physical Chemistry and the Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Givat Ram, Jerusalem (Israel)
| | - Anna M. Wu
- Crump Institute for Molecular Imaging and Department of Molecular & Medical Pharmacology, UCLA School of Medicine, Los Angeles, CA 90005-1770 (USA)
| | - Robert Sinclair
- Stanford Nanocharacterization Laboratory, Department of Materials Science and Engineering, Stanford University, Palo Alto, CA 94305-5427 (USA)
| | - Shimon Weiss
- California NanoSystems Institute (CNSI) and Department of Chemistry and Biochemistry, UCLA School of Medicine, Los Angeles, CA 90005-1770 (USA)
| | - Sanjiv S. Gambhir
- Molecular Imaging Program at Stanford (MIPS), Departments of Radiology and Bioengineering, Bio-X Program, Stanford University, 318 Campus Drive, Palo Alto, CA 94305-5427 (USA)
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Schipper ML, Cheng Z, Lee SW, Bentolila LA, Iyer G, Rao J, Chen X, Wu AM, Weiss S, Gambhir SS. microPET-based biodistribution of quantum dots in living mice. J Nucl Med 2007; 48:1511-8. [PMID: 17704240 PMCID: PMC4146342 DOI: 10.2967/jnumed.107.040071] [Citation(s) in RCA: 166] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED This study evaluates the quantitative biodistribution of commercially available CdSe quantum dots (QD) in mice. METHODS (64)Cu-Labeled 800- or 525-nm emission wavelength QD (21- or 12-nm diameter), with or without 2,000 MW (molecular weight) polyethylene glycol (PEG), were injected intravenously into mice (5.55 MBq/25 pmol QD) and studied using well counting or by serial microPET and region-of-interest analysis. RESULTS Both methods show rapid uptake by the liver (27.4-38.9 %ID/g) (%ID/g is percentage injected dose per gram tissue) and spleen (8.0-12.4 %ID/g). Size has no influence on biodistribution within the range tested here. Pegylated QD have slightly slower uptake into liver and spleen (6 vs. 2 min) and show additional low-level bone uptake (6.5-6.9 %ID/g). No evidence of clearance from these organs was observed. CONCLUSION Rapid reticuloendothelial system clearance of QD will require modification of QD for optimal utility in imaging living subjects. Formal quantitative biodistribution/imaging studies will be helpful in studying many types of nanoparticles, including quantum dots.
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Affiliation(s)
- Meike L. Schipper
- Departments of Radiology and Bioengineering, Bio-X Program, Molecular Imaging Program at Stanford (MIPS), Stanford University, Stanford, California
| | - Zhen Cheng
- Departments of Radiology and Bioengineering, Bio-X Program, Molecular Imaging Program at Stanford (MIPS), Stanford University, Stanford, California
| | - Sheen-Woo Lee
- Departments of Radiology and Bioengineering, Bio-X Program, Molecular Imaging Program at Stanford (MIPS), Stanford University, Stanford, California
| | - Laurent A. Bentolila
- California NanoSystems Institute (CNSI), UCLA School of Medicine, Los Angeles, California
- Department of Chemistry and Biochemistry, UCLA School of Medicine, Los Angeles, California
| | - Gopal Iyer
- Department of Chemistry and Biochemistry, UCLA School of Medicine, Los Angeles, California
| | - Jianghong Rao
- Departments of Radiology and Bioengineering, Bio-X Program, Molecular Imaging Program at Stanford (MIPS), Stanford University, Stanford, California
| | - Xiaoyuan Chen
- Departments of Radiology and Bioengineering, Bio-X Program, Molecular Imaging Program at Stanford (MIPS), Stanford University, Stanford, California
| | - Anna M. Wu
- Department of Molecular & Medical Pharmacology, Crump Institute for Molecular Imaging, UCLA School of Medicine, Los Angeles, California
| | - Shimon Weiss
- California NanoSystems Institute (CNSI), UCLA School of Medicine, Los Angeles, California
- Department of Chemistry and Biochemistry, UCLA School of Medicine, Los Angeles, California
| | - Sanjiv S. Gambhir
- Departments of Radiology and Bioengineering, Bio-X Program, Molecular Imaging Program at Stanford (MIPS), Stanford University, Stanford, California
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Iyer G, Pinaud F, Tsay J, Li JJ, Bentolila LA, Michalet X, Weiss S. Notice of Violation of IEEE Publication Principles: Peptide coated quantum dots for biological applications. IEEE Trans Nanobioscience 2006; 5:231-8. [PMID: 17181021 PMCID: PMC3074086 DOI: 10.1109/tnb.2006.886563] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Quantum dots (QDOTs) have been widely recognized by the scientific community and the biotechnology industry, as witnessed by the exponential growth of this field in the past several years. We describe the synthesis and characterization of visible and near infrared QDots--a critical step for engineering organic molecules like proteins and peptides for building nanocomposite materials with multifunctional properties suitable for biological applications.
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Affiliation(s)
- Gopal Iyer
- Department of Chemistry & Biochemistry, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Fabien Pinaud
- Department of Chemistry & Biochemistry, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - James Tsay
- Department of Chemistry & Biochemistry, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Jack J. Li
- Department of Chemistry & Biochemistry, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Laurent A. Bentolila
- Department of Chemistry & Biochemistry, University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Xavier Michalet
- Department of Chemistry & Biochemistry, University of California at Los Angeles, Los Angeles, CA 90095, USA
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Bentolila LA, Weiss S. Single-step multicolor fluorescence in situ hybridization using semiconductor quantum dot-DNA conjugates. Cell Biochem Biophys 2006; 45:59-70. [PMID: 16679564 PMCID: PMC3084375 DOI: 10.1385/cbb:45:1:59] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 11/11/2022]
Abstract
We report a rapid method for the direct multicolor imaging of multiple subnuclear genetic sequences using novel quantum dot-based fluorescence in situ hybridization (FISH) probes (QD-FISH). Short DNA oligonucleotides were attached on QDs and used in a single hybridization/detection step of target sites in situ. QD-FISH probes penetrate both intact interphase nuclei and metaphase chromosomes and showed good targeting of dense chromatin domains with minimal steric hindrances. We further demonstrated that QD's broad absorption spectra allowed different colored probes specific for distinct subnuclear genetic sequences to be simultaneously excited with a single excitation wavelength and imaged free of chromatic aberrations in a single exposure. Thus, these results demonstrate that QD-FISH probes are very effective in multicolor FISH applications. This work also documents new possibilities of using QD-FISH probes detection down to the single molecule level.
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Affiliation(s)
- Laurent A Bentolila
- Department of Chemistry and Biochemistry, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA 90095-1569, USA.
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Iyer G, Li JJ, Pinaud F, Tsay JM, Bentolila LA, Michalet X, Weiss S. Near-infrared peptide-coated quantum dots for small animal imaging. Proc SPIE Int Soc Opt Eng 2006; 6096. [PMID: 29151665 DOI: 10.1117/12.661777] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
We have synthesized high quality type-II CdTe/CdSe near infrared quantum dots using successive ion layer adsorption and reaction chemistry. Transmission electron microscopy reveals that CdTe/CdSe can be synthesized layer by layer yielding quantum dots of narrow size distribution. Excitation and photoluminescence spectra reveal discrete type-II transitions, which correspond to energy lower that type-I bandgap. We have used a peptide coating technique on type-II and commercial near infrared quantum dots for delivery in live animals and cultured cells.
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Affiliation(s)
- Gopal Iyer
- Department of Chemistry & Biochemistry, University of California at Los Angeles 607 Charles E. Young Drive E., Los Angeles, CA 90095, USA
| | - Jack J Li
- Department of Chemistry & Biochemistry, University of California at Los Angeles 607 Charles E. Young Drive E., Los Angeles, CA 90095, USA
| | - Fabien Pinaud
- Department of Chemistry & Biochemistry, University of California at Los Angeles 607 Charles E. Young Drive E., Los Angeles, CA 90095, USA
| | - James M Tsay
- Department of Chemistry & Biochemistry, University of California at Los Angeles 607 Charles E. Young Drive E., Los Angeles, CA 90095, USA
| | - Laurent A Bentolila
- Department of Chemistry & Biochemistry, University of California at Los Angeles 607 Charles E. Young Drive E., Los Angeles, CA 90095, USA
| | - Xavier Michalet
- Department of Chemistry & Biochemistry, University of California at Los Angeles 607 Charles E. Young Drive E., Los Angeles, CA 90095, USA
| | - Shimon Weiss
- Department of Chemistry & Biochemistry, University of California at Los Angeles 607 Charles E. Young Drive E., Los Angeles, CA 90095, USA
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Pinaud F, Michalet X, Bentolila LA, Tsay JM, Doose S, Li JJ, Iyer G, Weiss S. Advances in fluorescence imaging with quantum dot bio-probes. Biomaterials 2006; 27:1679-87. [PMID: 16318871 PMCID: PMC3073483 DOI: 10.1016/j.biomaterials.2005.11.018] [Citation(s) in RCA: 272] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2005] [Accepted: 11/11/2005] [Indexed: 10/25/2022]
Abstract
After much effort in surface chemistry development and optimization by several groups, fluorescent semiconductor nanocrystals probes, also known as quantum dots or qdots, are now entering the realm of biological applications with much to offer to biologists. The road to success has been paved with hurdles but from these efforts has stemmed a multitude of original surface chemistries that scientists in the biological fields can draw from for their specific biological applications. The ability to easily modulate the chemical nature of qdot surfaces by employing one or more of the recently developed qdot coatings, together with their exceptional photophysics have been key elements for qdots to acquire a status of revolutionary fluorescent bio-probes. Indeed, the unique properties of qdots not only give biologists the opportunity to explore advanced imaging techniques such as single molecule or lifetime imaging but also to revisit traditional fluorescence imaging methodologies and extract yet unobserved or inaccessible information in vitro or in vivo.
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Affiliation(s)
- Fabien Pinaud
- Department of Chemistry & Biochemistry, UCLA, 607 Charles E. Young Drive East, Los Angeles, CA 90095, USA.
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Bentolila LA, Michalet X, Pinaud FF, Tsay JM, Doose S, Li JJ, Sundaresan G, Wu AM, Gambhir SS, Weiss S. Quantum dots for molecular imaging and cancer medicine. Discov Med 2005; 5:213-218. [PMID: 20704913 PMCID: PMC3399916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Extract: The past few decades have witnessed technical advances that have introduced cell biologists and physicians to a new, dynamic, subcellular world where genes and gene products can be visualized to interact in space and time and in health and disease. The accelerating field of molecular imaging has been critically dependent on indicator probes which show when and where genetically or biochemically defined molecules, signals or processes appear, interact and disappear, with high spatial and temporal resolution in living cells and whole organisms. For example, the use of radionuclide tracers combined with 3-dimensional (3-D) imaging systems such as Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT) are now helping clinicians to characterize the molecular status of tumors deep within patients. Other types of imaging probes rely on the bioluminescence and fluorescence of genetically encoded proteins (originally found in fireflies and jellyfish, respectively) or entirely synthetic fluorochromes, or a combination of both. New powerful biological fluorescence microscopes provide the ability to study single molecules within single cells. Multiphoton confocal microscopy has been developed to allow for the capturing of high-resolution, 3-D images of living tissues that have been tagged with highly specific fluorophores.
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Affiliation(s)
- L A Bentolila
- Department of Chemistry and Biochemistry, UCLA, Los Angeles, CA 90095, USA
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Wang L, Radu CG, Yang LV, Bentolila LA, Riedinger M, Witte ON. Lysophosphatidylcholine-induced surface redistribution regulates signaling of the murine G protein-coupled receptor G2A. Mol Biol Cell 2005; 16:2234-47. [PMID: 15728718 PMCID: PMC1087231 DOI: 10.1091/mbc.e04-12-1044] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Intracellular trafficking and spatial dynamics of membrane receptors critically regulate receptor function. Using microscopic and subcellular fractionation analysis, we studied the localization of the murine G protein-coupled receptor G2A (muG2A). Evaluating green fluorescent protein-tagged, exogenously expressed as well as the endogenous muG2A, we observed that this receptor was spontaneously internalized and accumulated in endosomal compartments, whereas its surface expression was enhanced and stabilized by lysophosphatidylcholine (LPC) treatment. Monensin, a general inhibitor of recycling pathways, blocked LPC-regulated surface localization of muG2A as well as muG2A-dependent extracellular signal-regulated kinase (ERK) activation and cell migration induced by LPC treatment. Mutation of the conserved DRY motif (R-->A) enhanced the surface expression of muG2A, resulting in its resistance to monensin inhibition of ERK activation. Our data suggest that intracellular sequestration and surface expression regulated by LPC, rather than direct agonistic activity control the signaling responses of murine G2A toward LPC.
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Affiliation(s)
- Li Wang
- Department of Microbiology, Immunology, and Molecular Genetics, UCLA, Los Angeles, CA 90095, USA
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Michalet X, Pinaud FF, Bentolila LA, Tsay JM, Doose S, Li JJ, Iyer G, Weiss S. Peptide-coated semiconductor nanocrystals for biomedical applications. Proc SPIE Int Soc Opt Eng 2005; 5704:10.1117/12.589498. [PMID: 29176922 PMCID: PMC5701801 DOI: 10.1117/12.589498] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
We have developed a new functionalization approach for semiconductor nanocrystals based on a single-step exchange of surface ligands with custom-designed peptides. This peptide-coating technique yield small, monodisperse and very stable water-soluble NCs that remain bright and photostable. We have used this approach on several types of core and core-shell NCs in the visible and near-infrared spectrum range and used fluorescence correlation spectroscopy for rapid assessment of the colloidal and photophysical properties of the resulting particles. This peptide coating strategy has several advantages: it yields probes that are immediately biocompatible; it is amenable to improvements of the different properties (solubilization, functionalization, etc) via rational design, parallel synthesis, or molecular evolution; it permits the combination of several functions on individual NCs. These functionalized NCs have been used for diverse biomedical applications. Two are discussed here: single-particle tracking of membrane receptor in live cells and combined fluorescence and PET imaging of targeted delivery in live animals.
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Affiliation(s)
- X Michalet
- Dpt of Chemistry & Biochemistry, UCLA, 607 Charles E. Young Drive East, Los Angeles, CA 90095
| | - F F Pinaud
- Dpt of Chemistry & Biochemistry, UCLA, 607 Charles E. Young Drive East, Los Angeles, CA 90095
| | - L A Bentolila
- Dpt of Chemistry & Biochemistry, UCLA, 607 Charles E. Young Drive East, Los Angeles, CA 90095
| | - J M Tsay
- Dpt of Chemistry & Biochemistry, UCLA, 607 Charles E. Young Drive East, Los Angeles, CA 90095
| | - S Doose
- Applied Laserphysics & Laserspectroscopy, University of Bielefeld 33615 Bielefeld, Germany
| | - J J Li
- Dpt of Chemistry & Biochemistry, UCLA, 607 Charles E. Young Drive East, Los Angeles, CA 90095
| | - G Iyer
- Dpt of Chemistry & Biochemistry, UCLA, 607 Charles E. Young Drive East, Los Angeles, CA 90095
| | - S Weiss
- Dpt of Chemistry & Biochemistry, UCLA, 607 Charles E. Young Drive East, Los Angeles, CA 90095
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Abstract
We report the synthesis of highly luminescent CdTe/ZnS and CdHgTe/ZnS core/shell semiconductor nanocrystals (NCs). A hybrid of two synthesis routes leads to novel nanocrystal compositions and small core/shell sizes (4-5 nm) that emit in the far-red and near-infrared regions. These particles exhibit higher resistance to oxidation and photobleaching, have high quantum yields, and could be used for biological labeling and imaging.
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Affiliation(s)
- James M Tsay
- Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, California 90095, USA
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Bentolila LA, Olson S, Marshall A, Rougeon F, Paige CJ, Doyen N, Wu GE. Extensive junctional diversity in Ig light chain genes from early B cell progenitors of mu MT mice. J Immunol 1999; 162:2123-8. [PMID: 9973486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Nontemplated (N) nucleotide additions contribute significantly to the junctional diversity of all Ag receptor chains in adult mice except Ig light (L) chains, primarily because terminal deoxynucleotidyl transferase (TdT) expression is turned off at the time of their rearrangement in pre-B cells. However, because some Ig L chain gene rearrangements are detectable earlier during B cell ontogeny when TdT expression is thought to be maximal, we have examined the junctional processing of kappa- and lambda-chain genes of CD45(B220)+CD43+ pro-B cells from mu MT mice. We found that both kappa and lambda coding junctions formed in these B cell precursors were extensively diversified with N-region additions. Together, these findings demonstrate that Ig L chain genes are equally accessible to TdT in pro-B cells as Ig heavy chain genes. Surprisingly, however, the two L chain isotypes differed in the pattern of N addition, which was more prevalent at the lambda-chain locus. We observed the same diversity pattern in pre-B cells from TdT-transgenic mice. These results suggest that some aspects of TdT processing could be influenced by factors intrinsic to the sequence of Ig genes and/or the process of V(D)J recombination itself.
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Affiliation(s)
- L A Bentolila
- Unité de Génétique et Biochimie du Développement, Unité de Recherche Associée, Centre National de la Recherche Scientifique 1960, Département d'Immunologie, Institut Pasteur, Paris, France
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Bentolila LA, Olson S, Marshall A, Rougeon F, Paige CJ, Doyen N, Wu GE. Extensive Junctional Diversity in Ig Light Chain Genes from Early B Cell Progenitors of μMT Mice. The Journal of Immunology 1999. [DOI: 10.4049/jimmunol.162.4.2123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Nontemplated (N) nucleotide additions contribute significantly to the junctional diversity of all Ag receptor chains in adult mice except Ig light (L) chains, primarily because terminal deoxynucleotidyl transferase (TdT) expression is turned off at the time of their rearrangement in pre-B cells. However, because some Ig L chain gene rearrangements are detectable earlier during B cell ontogeny when TdT expression is thought to be maximal, we have examined the junctional processing of κ- and λ-chain genes of CD45(B220)+CD43+ pro-B cells from μMT mice. We found that both κ and λ coding junctions formed in these B cell precursors were extensively diversified with N-region additions. Together, these findings demonstrate that Ig L chain genes are equally accessible to TdT in pro-B cells as Ig heavy chain genes. Surprisingly, however, the two L chain isotypes differed in the pattern of N addition, which was more prevalent at the λ-chain locus. We observed the same diversity pattern in pre-B cells from TdT-transgenic mice. These results suggest that some aspects of TdT processing could be influenced by factors intrinsic to the sequence of Ig genes and/or the process of V(D)J recombination itself.
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Affiliation(s)
- Laurent A. Bentolila
- *Unité de Génétique et Biochimie du Développement, Unité de Recherche Associée, Centre National de la Recherche Scientifique 1960, Département d’Immunologie, Institut Pasteur, Paris, France; and
| | - Stacy Olson
- †Department of Immunology, University of Toronto, and Ontario Cancer Institute, Toronto, Canada
| | - Aaron Marshall
- †Department of Immunology, University of Toronto, and Ontario Cancer Institute, Toronto, Canada
| | - François Rougeon
- *Unité de Génétique et Biochimie du Développement, Unité de Recherche Associée, Centre National de la Recherche Scientifique 1960, Département d’Immunologie, Institut Pasteur, Paris, France; and
| | - Christopher J. Paige
- †Department of Immunology, University of Toronto, and Ontario Cancer Institute, Toronto, Canada
| | - Noëlle Doyen
- *Unité de Génétique et Biochimie du Développement, Unité de Recherche Associée, Centre National de la Recherche Scientifique 1960, Département d’Immunologie, Institut Pasteur, Paris, France; and
| | - Gillian E. Wu
- †Department of Immunology, University of Toronto, and Ontario Cancer Institute, Toronto, Canada
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Marshall AJ, Doyen N, Bentolila LA, Paige CJ, Wu GE. Terminal Deoxynucleotidyl Transferase Expression During Neonatal Life Alters DH Reading Frame Usage and Ig-Receptor-Dependent Selection of V Regions. The Journal of Immunology 1998. [DOI: 10.4049/jimmunol.161.12.6657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Abstract
During neonatal life, Ig diversity is limited in many respects. The absence of terminal deoxynucleotidyl transferase (TdT) expression with the consequent lack of nontemplated addition during the neonatal period, coupled with the predominant usage of a single DH reading frame (RF), leads to severe limitations of diversity in the CDR3 region of Ig heavy (H) chains. The neonatal Ig H chain repertoire is also characterized by restricted VH usage, with predominant expression of certain VH segments, such as VH81x, that are rarely evident during adult life. In this report, we examine the effect of enforced TdT expression on the neonatal repertoire of VH81xDJH rearrangements. We find that TdT synthesis abrogates DH RF bias during the fetal/neonatal period through a Ig-receptor-independent mechanism. These findings suggest that DH RF bias during neonatal life is determined largely by homology-directed joining. We also find that TdT synthesis alters the selection of productively rearranged VH81xDJH alleles in the neonatal spleen through a Ig-receptor-dependent mechanism. Analysis of predicted CDR3 amino acid sequences indicates that positive selection of VH81x-encoded H chains is correlated with the presence of a consensus sequence immediately adjacent to the VH segment. These data support the hypothesis that the CDR3 region is critical in determining the ability of VH81x-encoded H chains to form functional receptors that support positive selection of B lymphocytes. Together, our results demonstrate that TdT can indirectly influence the Ig repertoire by influencing both receptor-dependent and receptor-independent selection processes.
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Affiliation(s)
- Aaron J. Marshall
- *Ontario Cancer Institute and Department of Immunology, University of Toronto, Toronto, Ontario, Canada; and
| | - Noelle Doyen
- †Unité de Génétique et Biochimie du Développement, Unité de Recherche Associée Centre National de la Recherche Scientifique 1960, Département d’Immunologie, Institut Pasteur, Paris, France
| | - Laurent A. Bentolila
- †Unité de Génétique et Biochimie du Développement, Unité de Recherche Associée Centre National de la Recherche Scientifique 1960, Département d’Immunologie, Institut Pasteur, Paris, France
| | - Christopher J. Paige
- *Ontario Cancer Institute and Department of Immunology, University of Toronto, Toronto, Ontario, Canada; and
| | - Gillian E. Wu
- *Ontario Cancer Institute and Department of Immunology, University of Toronto, Toronto, Ontario, Canada; and
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Marshall AJ, Doyen N, Bentolila LA, Paige CJ, Wu GE. Terminal deoxynucleotidyl transferase expression during neonatal life alters D(H) reading frame usage and Ig-receptor-dependent selection of V regions. J Immunol 1998; 161:6657-63. [PMID: 9862694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
During neonatal life, Ig diversity is limited in many respects. The absence of terminal deoxynucleotidyl transferase (TdT) expression with the consequent lack of nontemplated addition during the neonatal period, coupled with the predominant usage of a single D(H) reading frame (RF), leads to severe limitations of diversity in the CDR3 region of Ig heavy (H) chains. The neonatal Ig H chain repertoire is also characterized by restricted V(H) usage, with predominant expression of certain V(H) segments, such as V(H)81x, that are rarely evident during adult life. In this report, we examine the effect of enforced TdT expression on the neonatal repertoire of V(H)81xDJ(H) rearrangements. We find that TdT synthesis abrogates D(H) RF bias during the fetal/neonatal period through a Ig-receptor-independent mechanism. These findings suggest that D(H) RF bias during neonatal life is determined largely by homology-directed joining. We also find that TdT synthesis alters the selection of productively rearranged V(H)81xDJ(H) alleles in the neonatal spleen through a Ig-receptor-dependent mechanism. Analysis of predicted CDR3 amino acid sequences indicates that positive selection of V(H)81x-encoded H chains is correlated with the presence of a consensus sequence immediately adjacent to the V(H) segment. These data support the hypothesis that the CDR3 region is critical in determining the ability of V(H)81x-encoded H chains to form functional receptors that support positive selection of B lymphocytes. Together, our results demonstrate that TdT can indirectly influence the Ig repertoire by influencing both receptor-dependent and receptor-independent selection processes.
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Affiliation(s)
- A J Marshall
- Ontario Cancer Institute and Department of Immunology, University of Toronto, Ontario, Canada
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Bentolila LA, Wu GE, Nourrit F, Fanton d'Andon M, Rougeon F, Doyen N. Constitutive expression of terminal deoxynucleotidyl transferase in transgenic mice is sufficient for N region diversity to occur at any Ig locus throughout B cell differentiation. J Immunol 1997; 158:715-23. [PMID: 8992987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
N region diversity in Ag receptors is a developmentally regulated process in B and T cells that correlates with the differential expression of terminal deoxynucleotidyl transferase (TdT). Absent in fetal and newborn mice, TdT expression is restricted to early T and pro-B cells in adults. To extend the TdT expression pattern throughout B cell ontogenesis, we generated transgenic mice carrying a TdT cDNA under the regulatory elements of the N-myc gene and the IgH enhancer. High expression was observed in secondary lymphoid organs consistent with TdT activity beyond the pre-B cell stage. This suggests that TdT transgene expression is not down-regulated as is the endogenous gene. Unlike normal mice, extensive N region diversity was found in rearranged lambda light chain genes of adult transgenic animals. Therefore, expression of TdT appears sufficient for N region diversity to occur at any Ig locus. More importantly, expression of the transgene takes place during fetal development. As a consequence, the potential fetal B cell repertoire is modified as both rearranged heavy and light chain genes now show N region additions. Constitutive expression of TdT throughout B cell differentiation does not therefore appear deleterious and suggests that TdT is recruited only to participate in the V(D)J recombination process.
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Affiliation(s)
- L A Bentolila
- Unit of Genetics and Developmental Biochemistry, National Center for Scientific Research, Paris, France
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Bentolila LA, Wu GE, Nourrit F, Fanton d'Andon M, Rougeon F, Doyen N. Constitutive expression of terminal deoxynucleotidyl transferase in transgenic mice is sufficient for N region diversity to occur at any Ig locus throughout B cell differentiation. The Journal of Immunology 1997. [DOI: 10.4049/jimmunol.158.2.715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Abstract
N region diversity in Ag receptors is a developmentally regulated process in B and T cells that correlates with the differential expression of terminal deoxynucleotidyl transferase (TdT). Absent in fetal and newborn mice, TdT expression is restricted to early T and pro-B cells in adults. To extend the TdT expression pattern throughout B cell ontogenesis, we generated transgenic mice carrying a TdT cDNA under the regulatory elements of the N-myc gene and the IgH enhancer. High expression was observed in secondary lymphoid organs consistent with TdT activity beyond the pre-B cell stage. This suggests that TdT transgene expression is not down-regulated as is the endogenous gene. Unlike normal mice, extensive N region diversity was found in rearranged lambda light chain genes of adult transgenic animals. Therefore, expression of TdT appears sufficient for N region diversity to occur at any Ig locus. More importantly, expression of the transgene takes place during fetal development. As a consequence, the potential fetal B cell repertoire is modified as both rearranged heavy and light chain genes now show N region additions. Constitutive expression of TdT throughout B cell differentiation does not therefore appear deleterious and suggests that TdT is recruited only to participate in the V(D)J recombination process.
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Affiliation(s)
- L A Bentolila
- Unit of Genetics and Developmental Biochemistry, National Center for Scientific Research, Paris, France
| | - G E Wu
- Unit of Genetics and Developmental Biochemistry, National Center for Scientific Research, Paris, France
| | - F Nourrit
- Unit of Genetics and Developmental Biochemistry, National Center for Scientific Research, Paris, France
| | - M Fanton d'Andon
- Unit of Genetics and Developmental Biochemistry, National Center for Scientific Research, Paris, France
| | - F Rougeon
- Unit of Genetics and Developmental Biochemistry, National Center for Scientific Research, Paris, France
| | - N Doyen
- Unit of Genetics and Developmental Biochemistry, National Center for Scientific Research, Paris, France
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Bentolila LA, Fanton d'Andon M, Nguyen QT, Martinez O, Rougeon F, Doyen N. The two isoforms of mouse terminal deoxynucleotidyl transferase differ in both the ability to add N regions and subcellular localization. EMBO J 1995; 14:4221-9. [PMID: 7556063 PMCID: PMC394505 DOI: 10.1002/j.1460-2075.1995.tb00096.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Two alternatively spliced terminal deoxynucleotidyl transferase transcripts, TdTS and TdTL which code respectively for proteins of 509 and 529 amino acids have been previously identified in the mouse thymus. Here we show that the same two transcripts are also present in B lineage cells from bone marrow. In addition we demonstrate that the corresponding 20 amino acid insertion found near the carboxy-terminal end of TdTL significantly alters the function of the enzyme. In contrast to TdTS, TdTL does not catalyse N region insertions at the recombination junction of a V(D)J site-specific recombination substrate. In an attempt to explain the lack of N region insertions we have characterized the different parameters which distinguish the two isoforms of TdT. Examination of transfected cell extracts revealed a reduced capacity of TdTL to add nucleotides to the 3' end of DNA, consistent with a lower terminal transferase activity. Furthermore, the half-life of the TdTL protein in these cells is 2-fold shorter than that of TdTS. Finally, despite the fact that TdTL has the same nuclear localization signal as TdTS, the cellular localization of the two isoforms was strikingly different. In contrast to nuclear TdTS, TdTL was found exclusively in the cytoplasm. All these characteristics could contribute to the functional difference between the two isoforms of TdT. However, the subcellular localization of TdTL on its own can account for its inability to add N regions.
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Affiliation(s)
- L A Bentolila
- Unité de Génétique et Biochimie du Développement, Paris Cédex 15, France
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Doyen N, d'Andon MF, Bentolila LA, Nguyen QT, Rougeon F. Differential splicing in mouse thymus generates two forms of terminal deoxynucleotidyl transferase. Nucleic Acids Res 1993; 21:1187-91. [PMID: 8464703 PMCID: PMC309280 DOI: 10.1093/nar/21.5.1187] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
A new form of TdT mRNA has been identified by screening a mouse thymus cDNA library. It contains an open reading frame of 1527 base pairs corresponding to a protein containing 509 aminoacids, whereas the previously identified mouse TdT mRNA is composed of 1587 base pairs and encodes a protein of 529 aminoacids. Analysis of a mouse genomic clone containing the 3' portion of the TdT gene shows that these twenty additional aminoacids are encoded by an additional exon located between exons X and XI. Both forms of TdT mRNA are present in the thymus and could be generated by alternative splicing. The cDNA reported here corresponds to the major form of TdT mRNA in Balb/c mice and closely resembles human and bovine TdT cDNA. Expression of this cDNA in mammalian cells shows that it encodes a functional protein capable of catalysing N region insertions at the recombination junction of an episomic recombination substrate.
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Affiliation(s)
- N Doyen
- Institut Pasteur, Unité de Génétique et Biochimie du Développement, URA CNRS 361, Département d'Immunologie, Paris, France
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