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Aviner R, Lee TT, Masto VB, Li KH, Andino R, Frydman J. Polyglutamine-mediated ribotoxicity disrupts proteostasis and stress responses in Huntington's disease. Nat Cell Biol 2024:10.1038/s41556-024-01414-x. [PMID: 38741019 DOI: 10.1038/s41556-024-01414-x] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 04/01/2024] [Indexed: 05/16/2024]
Abstract
Huntington's disease (HD) is a neurodegenerative disorder caused by expansion of a CAG trinucleotide repeat in the Huntingtin (HTT) gene, encoding a homopolymeric polyglutamine (polyQ) tract. Although mutant HTT (mHTT) protein is known to aggregate, the links between aggregation and neurotoxicity remain unclear. Here we show that both translation and aggregation of wild-type HTT and mHTT are regulated by a stress-responsive upstream open reading frame and that polyQ expansions cause abortive translation termination and release of truncated, aggregation-prone mHTT fragments. Notably, we find that mHTT depletes translation elongation factor eIF5A in brains of symptomatic HD mice and cultured HD cells, leading to pervasive ribosome pausing and collisions. Loss of eIF5A disrupts homeostatic controls and impairs recovery from acute stress. Importantly, drugs that inhibit translation initiation reduce premature termination and mitigate this escalating cascade of ribotoxic stress and dysfunction in HD.
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Affiliation(s)
- Ranen Aviner
- Department of Biology and Department of Genetics, Stanford University, Stanford, CA, USA
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
- Chan Zuckerberg Biohub San Francisco, San Francisco, CA, USA
| | - Ting-Ting Lee
- Department of Biology and Department of Genetics, Stanford University, Stanford, CA, USA
| | - Vincent B Masto
- Department of Biology and Department of Genetics, Stanford University, Stanford, CA, USA
| | - Kathy H Li
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, USA
| | - Raul Andino
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
| | - Judith Frydman
- Department of Biology and Department of Genetics, Stanford University, Stanford, CA, USA.
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2
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Subramanian A, Wang L, Moss T, Voorhies M, Sangwan S, Stevenson E, Pulido EH, Kwok S, Chalkley RJ, Li KH, Krogan NJ, Swaney DL, Burlingame AL, Floor SN, Sil A, Walter P, Mukherjee S. A Legionella toxin exhibits tRNA mimicry and glycosyl transferase activity to target the translation machinery and trigger a ribotoxic stress response. Nat Cell Biol 2023; 25:1600-1615. [PMID: 37857833 PMCID: PMC11005034 DOI: 10.1038/s41556-023-01248-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [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: 11/08/2022] [Accepted: 09/01/2023] [Indexed: 10/21/2023]
Abstract
A widespread strategy employed by pathogens to establish infection is to inhibit host-cell protein synthesis. Legionella pneumophila, an intracellular bacterial pathogen and the causative organism of Legionnaires' disease, secretes a subset of protein effectors into host cells that inhibit translation elongation. Mechanistic insights into how the bacterium targets translation elongation remain poorly defined. We report here that the Legionella effector SidI functions in an unprecedented way as a transfer-RNA mimic that directly binds to and glycosylates the ribosome. The 3.1 Å cryo-electron microscopy structure of SidI reveals an N-terminal domain with an 'inverted L' shape and surface-charge distribution characteristic of tRNA mimicry, and a C-terminal domain that adopts a glycosyl transferase fold that licenses SidI to utilize GDP-mannose as a sugar precursor. This coupling of tRNA mimicry and enzymatic action endows SidI with the ability to block protein synthesis with a potency comparable to ricin, one of the most powerful toxins known. In Legionella-infected cells, the translational pausing activated by SidI elicits a stress response signature mimicking the ribotoxic stress response, which is activated by elongation inhibitors that induce ribosome collisions. SidI-mediated effects on the ribosome activate the stress kinases ZAKα and p38, which in turn drive an accumulation of the protein activating transcription factor 3 (ATF3). Intriguingly, ATF3 escapes the translation block imposed by SidI, translocates to the nucleus and orchestrates the transcription of stress-inducible genes that promote cell death, revealing a major role for ATF3 in the response to collided ribosome stress. Together, our findings elucidate a novel mechanism by which a pathogenic bacterium employs tRNA mimicry to hijack a ribosome-to-nuclear signalling pathway that regulates cell fate.
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Affiliation(s)
- Advait Subramanian
- G.W. Hooper Foundation, University of California at San Francisco, San Francisco, CA, USA
- Department of Microbiology and Immunology, University of California at San Francisco, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, CA, USA
| | - Lan Wang
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, CA, USA
| | - Tom Moss
- G.W. Hooper Foundation, University of California at San Francisco, San Francisco, CA, USA
- Department of Microbiology and Immunology, University of California at San Francisco, San Francisco, CA, USA
| | - Mark Voorhies
- Department of Microbiology and Immunology, University of California at San Francisco, San Francisco, CA, USA
| | - Smriti Sangwan
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, CA, USA
| | - Erica Stevenson
- Gladstone Institute of Data Science and Biotechnology, J. Gladstone Institutes, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, CA, USA
- Quantitative Biosciences Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Ernst H Pulido
- Gladstone Institute of Data Science and Biotechnology, J. Gladstone Institutes, San Francisco, CA, USA
| | - Samentha Kwok
- Department of Cell and Tissue Biology, University of California at San Francisco, San Francisco, CA, USA
| | - Robert J Chalkley
- Mass Spectrometry Facility, Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, CA, USA
| | - Kathy H Li
- Mass Spectrometry Facility, Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, CA, USA
| | - Nevan J Krogan
- Gladstone Institute of Data Science and Biotechnology, J. Gladstone Institutes, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, CA, USA
- Quantitative Biosciences Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Danielle L Swaney
- Gladstone Institute of Data Science and Biotechnology, J. Gladstone Institutes, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, CA, USA
- Quantitative Biosciences Institute, University of California at San Francisco, San Francisco, CA, USA
| | - Alma L Burlingame
- Mass Spectrometry Facility, Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, CA, USA
| | - Stephen N Floor
- Department of Cell and Tissue Biology, University of California at San Francisco, San Francisco, CA, USA
- Helen Diller Family Comprehensive Cancer Center, University of California at San Francisco, San Francisco, CA, USA
| | - Anita Sil
- Department of Microbiology and Immunology, University of California at San Francisco, San Francisco, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Peter Walter
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, CA, USA.
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, CA, USA.
- Bay Area Institute of Science, Altos Labs, Redwood City, CA, USA.
| | - Shaeri Mukherjee
- G.W. Hooper Foundation, University of California at San Francisco, San Francisco, CA, USA.
- Department of Microbiology and Immunology, University of California at San Francisco, San Francisco, CA, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
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3
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Vozdek R, Wang B, Li KH, Pramstaller PP, Hicks AA, Ma DK. Fluorescent reporter of Caenorhabditis elegans Parkin: Regulators of its abundance and role in autophagy-lysosomal dynamics. Open Res Eur 2023; 2:23. [PMID: 37811477 PMCID: PMC10556562 DOI: 10.12688/openreseurope.14235.2] [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] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 09/11/2023] [Indexed: 10/10/2023]
Abstract
Background: Parkin, which when mutated leads to early-onset Parkinson's disease, acts as an E3 ubiquitin ligase. How Parkin is regulated for selective protein and organelle targeting is not well understood. Here, we used protein interactor and genetic screens in Caenorhabditis elegans ( C. elegans) to identify new regulators of Parkin abundance and showed their impact on autophagy-lysosomal dynamics and alpha-Synuclein processing. Methods: We generated a transgene encoding mCherry-tagged C. elegans Parkin - Parkinson's Disease Related 1 (PDR-1). We performed protein interactor screen using Co-immunoprecipitation followed by mass spectrometry analysis to identify putative interacting partners of PDR-1. Ribonucleic acid interference (RNAi) screen and an unbiased mutagenesis screen were used to identify genes regulating PDR-1 abundance. Confocal microscopy was used for the identification of the subcellular localization of PDR-1 and alpha-Synuclein processing. Results: We show that the mCherry::pdr-1 transgene rescues the mitochondrial phenotype of pdr-1 mutants and that the expressed PDR-1 reporter is localized in the cytosol with enriched compartmentalization in the autophagy-lysosomal system. We determined that the transgenic overexpression of the PDR-1 reporter, due to inactivated small interfering RNA (siRNA) generation pathway, disrupts autophagy-lysosomal dynamics. From the RNAi screen of putative PDR-1 interactors we found that the inactivated Adenine Nucleotide Translocator ant-1.1/hANT, or hybrid ubiquitin genes ubq-2/h UBA52 and ubl-1/h RPS27A encoding a single copy of ubiquitin fused to the ribosomal proteins L40 and S27a, respectively, induced PDR-1 abundance and affected lysosomal dynamics. In addition, we demonstrate that the abundant PDR-1 plays a role in alpha-Synuclein processing. Conclusions: These data show that the abundant reporter of C. elegans Parkin affects the autophagy-lysosomal system together with alpha-Synuclein processing which can help in understanding the pathology in Parkin-related diseases.
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Affiliation(s)
- Roman Vozdek
- Institute for Biomedicine, Eurac Research, Affiliated institute of the University of Lübeck, Bolzano, 39100, Italy
| | - Bingying Wang
- Cardiovascular Research Institute and Department of Physiology, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Kathy H. Li
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Peter P. Pramstaller
- Institute for Biomedicine, Eurac Research, Affiliated institute of the University of Lübeck, Bolzano, 39100, Italy
| | - Andrew A. Hicks
- Institute for Biomedicine, Eurac Research, Affiliated institute of the University of Lübeck, Bolzano, 39100, Italy
| | - Dengke K. Ma
- Cardiovascular Research Institute and Department of Physiology, University of California San Francisco, San Francisco, CA, 94158, USA
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4
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Betancourt Moreira K, Collier MP, Leitner A, Li KH, Lachapel ILS, McCarthy F, Opoku-Nsiah KA, Morales-Polanco F, Barbosa N, Gestaut D, Samant RS, Roh SH, Frydman J. A hierarchical assembly pathway directs the unique subunit arrangement of TRiC/CCT. Mol Cell 2023; 83:3123-3139.e8. [PMID: 37625406 DOI: 10.1016/j.molcel.2023.07.031] [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: 12/22/2021] [Revised: 05/07/2023] [Accepted: 07/31/2023] [Indexed: 08/27/2023]
Abstract
How the essential eukaryotic chaperonin TRiC/CCT assembles from eight distinct subunits into a unique double-ring architecture remains undefined. We show TRiC assembly involves a hierarchical pathway that segregates subunits with distinct functional properties until holocomplex (HC) completion. A stable, likely early intermediate arises from small oligomers containing CCT2, CCT4, CCT5, and CCT7, contiguous subunits that constitute the negatively charged hemisphere of the TRiC chamber, which has weak affinity for unfolded actin. The remaining subunits CCT8, CCT1, CCT3, and CCT6, which comprise the positively charged chamber hemisphere that binds unfolded actin more strongly, join the ring individually. Unincorporated late-assembling subunits are highly labile in cells, which prevents their accumulation and premature substrate binding. Recapitulation of assembly in a recombinant system demonstrates that the subunits in each hemisphere readily form stable, noncanonical TRiC-like HCs with aberrant functional properties. Thus, regulation of TRiC assembly along a biochemical axis disfavors the formation of stable alternative chaperonin complexes.
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Affiliation(s)
| | | | - Alexander Leitner
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| | - Kathy H Li
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, USA
| | | | | | | | | | - Natália Barbosa
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Daniel Gestaut
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Rahul S Samant
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Soung-Hun Roh
- School of Biological Sciences, Institute of Molecular Biology and Genetics, Seoul National University, Seoul, South Korea
| | - Judith Frydman
- Department of Biology, Stanford University, Stanford, CA, USA.
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5
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Bemben MA, Sandoval M, Le AA, Won S, Chau VN, Lauterborn JC, Incontro S, Li KH, Burlingame AL, Roche KW, Gall CM, Nicoll RA, Diaz-Alonso J. Contrastsing synaptic roles of MDGA1 and MDGA2. bioRxiv 2023:2023.05.25.542333. [PMID: 37720016 PMCID: PMC10503827 DOI: 10.1101/2023.05.25.542333] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
Neurodevelopmental disorders are frequently linked to mutations in synaptic organizing molecules. MAM domain containing glycosylphosphatidylinositol anchor 1 and 2 (MDGA1 and MDGA2) are a family of synaptic organizers suggested to play an unusual role as synaptic repressors, but studies offer conflicting evidence for their localization. Using epitope-tagged MDGA1 and MDGA2 knock-in mice, we found that native MDGAs are expressed throughout the brain, peaking early in postnatal development. Surprisingly, endogenous MDGA1 was enriched at excitatory, but not inhibitory, synapses. Both shRNA knockdown and CRISPR/Cas9 knockout of MDGA1 resulted in cell-autonomous, specific impairment of AMPA receptor-mediated synaptic transmission, without affecting GABAergic transmission. Conversely, MDGA2 knockdown/knockout selectively depressed NMDA receptor-mediated transmission but enhanced inhibitory transmission. Our results establish that MDGA2 acts as a synaptic repressor, but only at inhibitory synapses, whereas both MDGAs are required for excitatory transmission. This nonoverlapping division of labor between two highly conserved synaptic proteins is unprecedented.
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Affiliation(s)
- Michael A. Bemben
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, CA 94158, USA
| | - Matthew Sandoval
- Department of Anatomy & Neurobiology, University of California at Irvine, CA, 92617, USA
- Center for the Neurobiology of Learning and Memory, University of California at Irvine, CA, USA
| | - Aliza A. Le
- Department of Anatomy & Neurobiology, University of California at Irvine, CA, 92617, USA
- Center for the Neurobiology of Learning and Memory, University of California at Irvine, CA, USA
| | - Sehoon Won
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD, 20892, USA
| | - Vivian N. Chau
- Department of Anatomy & Neurobiology, University of California at Irvine, CA, 92617, USA
- Center for the Neurobiology of Learning and Memory, University of California at Irvine, CA, USA
| | - Julie C. Lauterborn
- Department of Anatomy & Neurobiology, University of California at Irvine, CA, 92617, USA
- Center for the Neurobiology of Learning and Memory, University of California at Irvine, CA, USA
| | - Salvatore Incontro
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, CA 94158, USA
- Present address: Unité de Neurobiologie des canaux Ioniques et de la Synapse (UNIS), UMR1072, INSERM, Aix-Marseille University, Marseille, 13015, France
| | - Kathy H. Li
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Alma L. Burlingame
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Katherine W. Roche
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD, 20892, USA
| | - Christine M. Gall
- Department of Anatomy & Neurobiology, University of California at Irvine, CA, 92617, USA
- Center for the Neurobiology of Learning and Memory, University of California at Irvine, CA, USA
| | - Roger A. Nicoll
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, CA 94158, USA
- Department of Physiology, University of California at San Francisco, San Francisco, CA, 94158, USA
| | - Javier Diaz-Alonso
- Department of Anatomy & Neurobiology, University of California at Irvine, CA, 92617, USA
- Center for the Neurobiology of Learning and Memory, University of California at Irvine, CA, USA
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6
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He L, Zhou G, Sofiyev V, Garcia E, Nguyen N, Li KH, Gochin M. Targeting a Conserved Lysine in the Hydrophobic Pocket of HIV-1 gp41 Improves Small Molecule Antiviral Activity. Viruses 2022; 14:v14122703. [PMID: 36560708 PMCID: PMC9784957 DOI: 10.3390/v14122703] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 11/29/2022] [Accepted: 11/30/2022] [Indexed: 12/03/2022] Open
Abstract
Human Immunodeficiency virus (HIV-1) fusion is mediated by glycoprotein-41, a protein that has not been widely exploited as a drug target. Small molecules directed at the gp41 ectodomain have proved to be poorly drug-like, having moderate efficacy, high hydrophobicity and/or high molecular weight. We recently investigated conversion of a fairly potent hydrophobic inhibitor into a covalent binder, by modifying it to react with a lysine residue on the protein. We demonstrated a 10-fold improvement in antiviral efficacy. Here, we continue this study, utilizing instead molecules with better inherent drug-like properties. Molecules possessing low to no antiviral activity as equilibrium binders were converted into µM inhibitors upon addition of an electrophilic warhead in the form of a sulfotetrafluorophenyl (STP) activated ester. We confirmed specificity for gp41 and for entry. The small size of the inhibitors described here offers an opportunity to expand their reach into neighboring pockets while retaining drug-likeness. STP esterification of equilibrium binders is a promising avenue to explore for inhibiting HIV-1 entry. Many gp41 targeting molecules studied over the years possess carboxylic acid groups which can be easily converted into the corresponding STP ester. It may be worth the effort to evaluate a library of such inhibitors as a way forward to small molecule inhibition of fusion of HIV and possibly other enveloped viruses.
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Affiliation(s)
- Li He
- Department of Basic Sciences, Touro University California College of Osteopathic Medicine, 1310 Club Drive, Mare Island, Vallejo, CA 94592, USA
| | - Guangyan Zhou
- Department of Basic Sciences, Touro University California College of Osteopathic Medicine, 1310 Club Drive, Mare Island, Vallejo, CA 94592, USA
| | - Vladimir Sofiyev
- Department of Basic Sciences, Touro University California College of Osteopathic Medicine, 1310 Club Drive, Mare Island, Vallejo, CA 94592, USA
| | - Eddie Garcia
- Master of Science in Medical Health Sciences, Touro University California College of Osteopathic Medicine, 1310 Club Drive, Mare Island, Vallejo, CA 94592, USA
| | - Newton Nguyen
- Master of Science in Medical Health Sciences, Touro University California College of Osteopathic Medicine, 1310 Club Drive, Mare Island, Vallejo, CA 94592, USA
| | - Kathy H. Li
- Department of Pharmaceutical Chemistry, UCSF School of Pharmacy, San Francisco, CA 94143, USA
| | - Miriam Gochin
- Department of Basic Sciences, Touro University California College of Osteopathic Medicine, 1310 Club Drive, Mare Island, Vallejo, CA 94592, USA
- Department of Pharmaceutical Chemistry, UCSF School of Pharmacy, San Francisco, CA 94143, USA
- Correspondence: ; Tel.: +1-707-638-5463
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7
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Li KH, Zhu Y, Zhang PH, Alini M, Grad S, Li Z. Osteochondral explants for diarthrodial joint diseases: bridging the gap between bench and bedside. Eur Cell Mater 2022; 44:74-89. [PMID: 36161648 DOI: 10.22203/ecm.v044a05] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Diarthrodial joint diseases, affecting hundreds of millions of people worldwide, mainly include osteoarthritis and cartilage injuries. No consensus on joint disease models has been achieved so far owing to the complex aetiologies, pathophysiological mechanisms and heterogeneity of disorders. The disease models established using isolated chondrocytes or small animals have the weaknesses of lacking native extracellular matrix and inter-species differences in anatomical and biomechanical cartilage properties. Osteochondral explants (OCEs) from large-animal or human joints present characteristics of native articular cartilage, showing promising potential for application in research on joint diseases. The present review focuses on OCEs and highlights the OCE sources, harvesting techniques, culture systems, applications and future developments. The OCE-centred ex vivo system has the potential to develop into preclinical models mimicking human joint diseases to help elucidate disease mechanisms, prompt therapeutic strategies and facilitate the clinical translation of findings in basic research.
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Affiliation(s)
| | | | | | | | | | - Z Li
- AO Research Institute Davos, Clavadelerstrasse 8, 7270 Davos Platz,
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8
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Loucks CM, Lin JJ, Trueman JN, Drögemöller BI, Wright GEB, Chang WC, Li KH, Yoshida EM, Ford JA, Lee SS, Crotty P, Kim RB, Al-Judaibi B, Schwarz UI, Ramji A, Farivar JF, Tam E, Walston LL, Ross CJD, Carleton BC. Patient-specific genetic factors predict treatment failure in sofosbuvir-treated patients with chronic hepatitis C. Liver Int 2022; 42:796-808. [PMID: 35107877 DOI: 10.1111/liv.15175] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 01/12/2022] [Indexed: 02/13/2023]
Abstract
BACKGROUND & AIMS According to pivotal clinical trials, cure rates for sofosbuvir-based antiviral therapy exceed 96%. Treatment failure is usually assumed to be because of virological resistance-associated substitutions or clinical risk factors, yet the role of patient-specific genetic factors has not been well explored. We determined if patient-specific genetic factors help predict patients likely to fail sofosbuvir treatment in real-world treatment situations. METHODS We recruited sofosbuvir-treated patients with chronic hepatitis C from five Canadian treatment sites, and performed a case-control pharmacogenomics study assessing both previously published and novel genetic polymorphisms. Specifically studied were variants predicted to impair CES1-dependent production of sofosbuvir's active metabolite, interferon-λ signalling variants expected to impact a patient's immune response to the virus and an HLA variant associated with increased spontaneous and treatment-induced viral clearance. RESULTS Three hundred and fifty-nine sofosbuvir-treated patients were available for analyses after exclusions, with 34 (9.5%) failing treatment. We identified CES1 variants as novel predictors for treatment failure in European patients (rs115629050 or rs4513095; odds ratio (OR): 5.43; 95% confidence interval (CI): 1.64-18.01; P = .0057), replicated associations with IFNL4 variants predicted to increase interferon-λ signalling (eg rs12979860; OR: 2.25; 95% CI: 1.25-4.06; P = .0071) and discovered a novel association with a coding variant predicted to enhance the activity of IFNL4's receptor (rs2834167 in IL10RB; OR: 1.81; 95% CI: 1.01-3.24; P = .047). CONCLUSIONS Ultimately, this work demonstrates that patient-specific genetic factors could be used as a tool to identify patients at higher risk of treatment failure and allow for these patients to receive effective therapy sooner.
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Affiliation(s)
- Catrina M Loucks
- BC Children's Hospital Research Institute, Vancouver, Canada.,Division of Translational Therapeutics, Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, Canada.,Department of Anesthesiology, Pharmacology & Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Jennifer J Lin
- BC Children's Hospital Research Institute, Vancouver, Canada.,Division of Translational Therapeutics, Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, Canada.,Department of Medical Genetics, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Jessica N Trueman
- BC Children's Hospital Research Institute, Vancouver, Canada.,Division of Translational Therapeutics, Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Britt I Drögemöller
- Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Galen E B Wright
- Department of Pharmacy and Therapeutics, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Wan-Chun Chang
- BC Children's Hospital Research Institute, Vancouver, Canada.,Division of Translational Therapeutics, Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Kathy H Li
- BC Children's Hospital Research Institute, Vancouver, Canada.,Division of Translational Therapeutics, Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Eric M Yoshida
- Division of Gastroenterology, Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Jo-Ann Ford
- Division of Gastroenterology, Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Samuel S Lee
- Liver Unit, University of Calgary Cumming School of Medicine, Calgary, Canada
| | - Pam Crotty
- Liver Unit, University of Calgary Cumming School of Medicine, Calgary, Canada
| | - Richard B Kim
- Division of Clinical Pharmacology, Department of Medicine, Western University, London, Canada
| | - Bandar Al-Judaibi
- Division of Transplantation, University of Rochester, Rochester, New York, USA.,Department of Liver Transplantation and Hepatobiliary Surgery, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Ute I Schwarz
- Division of Clinical Pharmacology, Department of Medicine, Western University, London, Canada
| | - Alnoor Ramji
- Division of Gastroenterology, Department of Medicine, University of British Columbia, Vancouver, Canada
| | | | | | | | - Colin J D Ross
- BC Children's Hospital Research Institute, Vancouver, Canada.,Department of Medical Genetics, Faculty of Medicine, University of British Columbia, Vancouver, Canada.,Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, Canada
| | - Bruce C Carleton
- BC Children's Hospital Research Institute, Vancouver, Canada.,Division of Translational Therapeutics, Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, Canada.,Department of Medical Genetics, Faculty of Medicine, University of British Columbia, Vancouver, Canada.,Pharmaceutical Outcomes Program (POPi), British Columbia Children's Hospital, Vancouver, Canada
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9
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Sun X, Bieber JM, Hammerlindl H, Chalkley RJ, Li KH, Burlingame AL, Jacobson MP, Wu LF, Altschuler SJ. Modulating environmental signals to reveal mechanisms and vulnerabilities of cancer persisters. Sci Adv 2022; 8:eabi7711. [PMID: 35089788 PMCID: PMC8797778 DOI: 10.1126/sciadv.abi7711] [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] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 12/08/2021] [Indexed: 06/14/2023]
Abstract
Cancer persister cells are able to survive otherwise lethal doses of drugs through nongenetic mechanisms, which can lead to cancer regrowth and drug resistance. The broad spectrum of molecular differences observed between persisters and their treatment-naïve counterparts makes it challenging to identify causal mechanisms underlying persistence. Here, we modulate environmental signals to identify cellular mechanisms that promote the emergence of persisters and to pinpoint actionable vulnerabilities that eliminate them. We found that interferon-γ (IFNγ) can induce a pro-persistence signal that can be specifically eliminated by inhibition of type I protein arginine methyltransferase (PRMT) (PRMTi). Mechanistic investigation revealed that signal transducer and activator of transcription 1 (STAT1) is a key component connecting IFNγ's pro-persistence and PRMTi's antipersistence effects, suggesting a previously unknown application of PRMTi to target persisters in settings with high STAT1 expression. Modulating environmental signals can accelerate the identification of mechanisms that promote and eliminate cancer persistence.
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Affiliation(s)
| | | | | | | | | | | | | | - Lani F. Wu
- Corresponding author. (S.J.A.); (L.F.W.)
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10
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Alquezar C, Schoch KM, Geier EG, Ramos EM, Scrivo A, Li KH, Argouarch AR, Mlynarski EE, Dombroski B, DeTure M, Dickson DW, Yokoyama JS, Cuervo AM, Burlingame AL, Schellenberg GD, Miller TM, Miller BL, Kao AW. TSC1 loss increases risk for tauopathy by inducing tau acetylation and preventing tau clearance via chaperone-mediated autophagy. Sci Adv 2021; 7:eabg3897. [PMID: 34739309 PMCID: PMC8570595 DOI: 10.1126/sciadv.abg3897] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Accepted: 09/17/2021] [Indexed: 05/20/2023]
Abstract
Age-associated neurodegenerative disorders demonstrating tau-laden intracellular inclusions are known as tauopathies. We previously linked a loss-of-function mutation in the TSC1 gene to tau accumulation and frontotemporal lobar degeneration. Now, we have identified genetic variants in TSC1 that decrease TSC1/hamartin levels and predispose to tauopathies such as Alzheimer’s disease and progressive supranuclear palsy. Cellular and murine models of TSC1 haploinsufficiency, as well as human brains carrying a TSC1 risk variant, accumulated tau protein that exhibited aberrant acetylation. This acetylation hindered tau degradation via chaperone-mediated autophagy, thereby leading to its accumulation. Aberrant tau acetylation in TSC1 haploinsufficiency resulted from the dysregulation of both p300 acetyltransferase and SIRT1 deacetylase. Pharmacological modulation of either enzyme restored tau levels. This study substantiates TSC1 as a novel tauopathy risk gene and includes TSC1 haploinsufficiency as a genetic model for tauopathies. In addition, these findings promote tau acetylation as a rational target for tauopathy therapeutics and diagnostic.
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Affiliation(s)
- Carolina Alquezar
- UCSF Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Kathleen M. Schoch
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Ethan G. Geier
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94143, USA
| | - Eliana Marisa Ramos
- Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Aurora Scrivo
- Institute for Aging Research, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Kathy H. Li
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA
| | - Andrea R. Argouarch
- UCSF Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Elisabeth E. Mlynarski
- Department of Pathology and Laboratory Medicine, Penn Neurodegeneration Genomics Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-4238, USA
| | - Beth Dombroski
- Department of Pathology and Laboratory Medicine, Penn Neurodegeneration Genomics Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-4238, USA
| | - Michael DeTure
- Department of Neuroscience, The Mayo Clinic Florida, 4500 San Pablo Road, Jacksonville, FL 32224, USA
| | - Dennis W. Dickson
- Department of Neuroscience, The Mayo Clinic Florida, 4500 San Pablo Road, Jacksonville, FL 32224, USA
| | - Jennifer S. Yokoyama
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA 94143, USA
| | - Ana M. Cuervo
- Institute for Aging Research, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Alma L. Burlingame
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA
| | - Gerard D. Schellenberg
- Department of Pathology and Laboratory Medicine, Penn Neurodegeneration Genomics Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-4238, USA
| | - Timothy M. Miller
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Bruce L. Miller
- UCSF Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Aimee W. Kao
- UCSF Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA 94158, USA
- Corresponding author.
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11
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Meijer AJM, Li KH, Brooks B, Clemens E, Ross CJ, Rassekh SR, Hoetink AE, van Grotel M, van den Heuvel-Eibrink MM, Carleton BC. The cumulative incidence of cisplatin-induced hearing loss in young children is higher and develops at an early stage during therapy compared with older children based on 2052 audiological assessments. Cancer 2021; 128:169-179. [PMID: 34490624 DOI: 10.1002/cncr.33848] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [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: 03/30/2021] [Revised: 04/30/2021] [Accepted: 05/17/2021] [Indexed: 11/09/2022]
Abstract
BACKGROUND Ototoxicity is a common adverse event of cisplatin treatment. The authors investigated the development of cisplatin-induced hearing loss (CIHL) over time in children with cancer by age and examined the influence of other clinical characteristics on the course of CIHL. METHODS Data from Canadian patients with childhood cancer were retrospectively reviewed. Hearing loss was graded according to International Society of Pediatric Oncology criteria. The Kaplan-Meier method was applied to estimate the cumulative incidence of CIHL for the total cohort and according to age. Cox regression models were used to explore the effects of independent variables on CIHL development up to 3 years after the start of therapy. RESULTS In total, 368 patients with 2052 audiological assessments were included. Three years after initiating therapy, the cumulative incidence of CIHL was highest in patients aged ≤5 years (75%; 95% confidence interval [CI], 66%-84%), with a rapid increase observed to 27% (95% CI, 21%-35%) at 3 months and to 61% (95% CI, 53%-69%) at 1 year, compared with patients aged >5 years (48%; 95% CI, 37%-62%; P < .001). The total cumulative dose of cisplatin at 3 months (per 100 mg/m2 increase: hazard ratio [HR], 1.20; 95% CI, 1.01-1.41) vincristine (HR, 2.87; 95% CI, 1.89-4.36) and the total duration of concomitantly administered antibiotics (>30 days: HR, 1.85; 95% CI, 1.17-2.95) further influenced CIHL development over time. CONCLUSIONS In young children, the cumulative incidence of CIHL is higher compared with that in older children and develops early during therapy. The course of CIHL is further influenced by the total cumulative dose of cisplatin and other ototoxic (co-)medication. These results highlight the need for audiological monitoring at each cisplatin cycle.
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Affiliation(s)
- Annelot J M Meijer
- Department of Pediatric Oncology, Princess Maxima Center for Pediatric Oncology, Utrecht, the Netherlands
| | - Kathy H Li
- British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Beth Brooks
- Department of Audiology and Speech Pathology, British Columbia Children's Hospital, Vancouver, British Columbia, Canada.,School of Audiology and Speech Science, University of British Columbia, Vancouver, British Columbia, Canada
| | - Eva Clemens
- Department of Pediatric Oncology, Princess Maxima Center for Pediatric Oncology, Utrecht, the Netherlands.,Department of Pediatric Oncology, Erasmus Medical Center-Sophia Children's Hospital, Rotterdam, the Netherlands
| | - Colin J Ross
- Pharmaceutical Outcomes Program, British Columbia Children's Hospital, Vancouver, British Columbia, Canada.,Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Sharad R Rassekh
- Division of Hematology, Oncology, and Bone Marrow Transplant, Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alex E Hoetink
- Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Center Utrecht-Wilhelmina Children's Hospital, Utrecht, the Netherlands
| | - Martine van Grotel
- Department of Pediatric Oncology, Princess Maxima Center for Pediatric Oncology, Utrecht, the Netherlands
| | - Marry M van den Heuvel-Eibrink
- Department of Pediatric Oncology, Princess Maxima Center for Pediatric Oncology, Utrecht, the Netherlands.,Department of Pediatric Oncology, Erasmus Medical Center-Sophia Children's Hospital, Rotterdam, the Netherlands
| | - Bruce C Carleton
- British Columbia Children's Hospital Research Institute, Vancouver, British Columbia, Canada.,Pharmaceutical Outcomes Program, British Columbia Children's Hospital, Vancouver, British Columbia, Canada.,Division of Translational Therapeutics, Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
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12
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Mohan S, Sampognaro PJ, Argouarch AR, Maynard JC, Welch M, Patwardhan A, Courtney EC, Zhang J, Mason A, Li KH, Huang EJ, Seeley WW, Miller BL, Burlingame A, Jacobson MP, Kao AW. Processing of progranulin into granulins involves multiple lysosomal proteases and is affected in frontotemporal lobar degeneration. Mol Neurodegener 2021; 16:51. [PMID: 34344440 PMCID: PMC8330050 DOI: 10.1186/s13024-021-00472-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 07/13/2021] [Indexed: 11/24/2022] Open
Abstract
Background Progranulin loss-of-function mutations are linked to frontotemporal lobar degeneration with TDP-43 positive inclusions (FTLD-TDP-Pgrn). Progranulin (PGRN) is an intracellular and secreted pro-protein that is proteolytically cleaved into individual granulin peptides, which are increasingly thought to contribute to FTLD-TDP-Pgrn disease pathophysiology. Intracellular PGRN is processed into granulins in the endo-lysosomal compartments. Therefore, to better understand the conversion of intracellular PGRN into granulins, we systematically tested the ability of different classes of endo-lysosomal proteases to process PGRN at a range of pH setpoints. Results In vitro cleavage assays identified multiple enzymes that can process human PGRN into multi- and single-granulin fragments in a pH-dependent manner. We confirmed the role of cathepsin B and cathepsin L in PGRN processing and showed that these and several previously unidentified lysosomal proteases (cathepsins E, G, K, S and V) are able to process PGRN in distinctive, pH-dependent manners. In addition, we have demonstrated a new role for asparagine endopeptidase (AEP) in processing PGRN, with AEP having the unique ability to liberate granulin F from the pro-protein. Brain tissue from individuals with FTLD-TDP-Pgrn showed increased PGRN processing to granulin F and increased AEP activity in degenerating brain regions but not in regions unaffected by disease. Conclusions This study demonstrates that multiple lysosomal proteases may work in concert to liberate multi-granulin fragments and granulins. It also implicates both AEP and granulin F in the neurobiology of FTLD-TDP-Pgrn. Modulating progranulin cleavage and granulin production may represent therapeutic strategies for FTLD-Pgrn and other progranulin-related diseases. Supplementary Information The online version contains supplementary material available at 10.1186/s13024-021-00472-1.
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Affiliation(s)
- Swetha Mohan
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, 94143, USA
| | - Paul J Sampognaro
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, 94143, USA
| | - Andrea R Argouarch
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, 94143, USA
| | - Jason C Maynard
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California, 94143, USA
| | - Mackenzie Welch
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, 94143, USA
| | - Anand Patwardhan
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, 94143, USA
| | - Emma C Courtney
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, 94143, USA
| | - Jiasheng Zhang
- Department of Pathology, University of California, San Francisco, California, 94143, USA
| | - Amanda Mason
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, 94143, USA
| | - Kathy H Li
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California, 94143, USA
| | - Eric J Huang
- Department of Pathology, University of California, San Francisco, California, 94143, USA
| | - William W Seeley
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, 94143, USA
| | - Bruce L Miller
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, 94143, USA
| | - Alma Burlingame
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California, 94143, USA
| | - Mathew P Jacobson
- Department of Pharmaceutical Chemistry, University of California, San Francisco, California, 94143, USA
| | - Aimee W Kao
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, California, 94143, USA.
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13
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Abstract
Viral pathogens are an ongoing threat to public health worldwide. Analysing their dependence on host biosynthetic pathways could lead to effective antiviral therapies1. Here we integrate proteomic analyses of polysomes with functional genomics and pharmacological interventions to define how enteroviruses and flaviviruses remodel host polysomes to synthesize viral proteins and disable host protein production. We find that infection with polio, dengue or Zika virus markedly modifies polysome composition, without major changes to core ribosome stoichiometry. These viruses use different strategies to evict a common set of translation initiation and RNA surveillance factors from polysomes while recruiting host machineries that are specifically required for viral biogenesis. Targeting these specialized viral polysomes could provide a new approach for antiviral interventions. For example, we find that both Zika and dengue use the collagen proline hydroxylation machinery to mediate cotranslational modification of conserved proline residues in the viral polyprotein. Genetic or pharmacological inhibition of proline hydroxylation impairs nascent viral polyprotein folding and induces its aggregation and degradation. Notably, such interventions prevent viral polysome remodelling and lower virus production. Our findings delineate the modular nature of polysome specialization at the virus-host interface and establish a powerful strategy to identify targets for selective antiviral interventions.
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Affiliation(s)
- Ranen Aviner
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
- Department of Biology and Genetics, Stanford University, Stanford, CA, USA
| | - Kathy H Li
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, USA
| | - Judith Frydman
- Department of Biology and Genetics, Stanford University, Stanford, CA, USA.
| | - Raul Andino
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA.
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14
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Collier MP, Moreira KB, Li KH, Chen YC, Itzhak D, Samant R, Leitner A, Burlingame A, Frydman J. Native mass spectrometry analyses of chaperonin complex TRiC/CCT reveal subunit N-terminal processing and re-association patterns. Sci Rep 2021; 11:13084. [PMID: 34158536 PMCID: PMC8219831 DOI: 10.1038/s41598-021-91086-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [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: 11/03/2020] [Accepted: 05/05/2021] [Indexed: 11/14/2022] Open
Abstract
The eukaryotic chaperonin TRiC/CCT is a large ATP-dependent complex essential for cellular protein folding. Its subunit arrangement into two stacked eight-membered hetero-oligomeric rings is conserved from yeast to man. A recent breakthrough enables production of functional human TRiC (hTRiC) from insect cells. Here, we apply a suite of mass spectrometry techniques to characterize recombinant hTRiC. We find all subunits CCT1-8 are N-terminally processed by combinations of methionine excision and acetylation observed in native human TRiC. Dissociation by organic solvents yields primarily monomeric subunits with a small population of CCT dimers. Notably, some dimers feature non-canonical inter-subunit contacts absent in the initial hTRiC. This indicates individual CCT monomers can promiscuously re-assemble into dimers, and lack the information to assume the specific interface pairings in the holocomplex. CCT5 is consistently the most stable subunit and engages in the greatest number of non-canonical dimer pairings. These findings confirm physiologically relevant post-translational processing and function of recombinant hTRiC and offer quantitative insight into the relative stabilities of TRiC subunits and interfaces, a key step toward reconstructing its assembly mechanism. Our results also highlight the importance of assigning contacts identified by native mass spectrometry after solution dissociation as canonical or non-canonical when investigating multimeric assemblies.
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Affiliation(s)
| | | | - Kathy H Li
- Department of Chemistry, University of California San Francisco, San Francisco, CA, USA
| | - Yu-Chan Chen
- Department of Biology, Stanford University, Stanford, CA, USA
| | | | - Rahul Samant
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Alexander Leitner
- Department of Biology, Institute of Molecular Systems Biology, Zurich, Switzerland
| | - Alma Burlingame
- Department of Chemistry, University of California San Francisco, San Francisco, CA, USA
| | - Judith Frydman
- Department of Biology, Stanford University, Stanford, CA, USA.
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15
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Zhou G, He L, Li KH, Pedroso CCS, Gochin M. A targeted covalent small molecule inhibitor of HIV-1 fusion. Chem Commun (Camb) 2021; 57:4528-4531. [PMID: 33956029 DOI: 10.1039/d1cc01013a] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We describe a low molecular weight covalent inhibitor targeting a conserved lysine residue within the hydrophobic pocket of HIV-1 glycoprotein-41. The inhibitor bound selectively to the hydrophobic pocket and exhibited an order of magnitude enhancement of anti-fusion activity against HIV-1 compared to its non-covalent counterpart. The findings represent a significant advance in the quest to obtain non-peptide fusion inhibitors.
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Affiliation(s)
- Guangyan Zhou
- Department of Basic Sciences, Touro University California, 1310 Club Drive, Mare Island, Vallejo, CA 94592, USA.
| | - Li He
- Department of Basic Sciences, Touro University California, 1310 Club Drive, Mare Island, Vallejo, CA 94592, USA.
| | - Kathy H Li
- Department of Pharmaceutical Chemistry, UCSF School of Pharmacy, San Francisco, CA 94143, USA
| | - Cássio C S Pedroso
- Lawrence Berkeley National Laboratory, The Molecular Foundry, 1 Cyclotron Road, 67R5114, Berkeley, CA 94720, USA
| | - Miriam Gochin
- Department of Basic Sciences, Touro University California, 1310 Club Drive, Mare Island, Vallejo, CA 94592, USA. and Department of Pharmaceutical Chemistry, UCSF School of Pharmacy, San Francisco, CA 94143, USA
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16
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Gober HJ, Li KH, Yan K, Bailey AJ, Carleton BC. Hydroxyzine Use in Preschool Children and Its Effect on Neurodevelopment: A Population-Based Longitudinal Study. Front Psychiatry 2021; 12:721875. [PMID: 35153845 PMCID: PMC8832122 DOI: 10.3389/fpsyt.2021.721875] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 12/28/2021] [Indexed: 11/13/2022] Open
Abstract
We identified the first-generation antihistamine hydroxyzine as the earliest and most frequently prescribed drug affecting the central nervous system in children under the age of 5 years in the province of British Columbia, Canada (1. 1% prevalence). Whereas, the antagonism of H1-receptors exerts anti-pruritic effects in atopic dermatitis and diaper rash, animal studies suggest an adverse association between reduced neurotransmission of histamine and psychomotor behavior. In order to investigate hydroxyzine safety, we characterized the longitudinal patterns of hydroxyzine use in children under the age of 5 years and determined mental- and psychomotor disorders up to the age of 10 years. We found significantly higher rates of ICD-9 and ICD-10 codes for disorders such as tics (307), anxiety (300) and disturbance of conduct (312) in frequent users of hydroxyzine. Specifically, repeat prescriptions of hydroxyzine compared to a single prescription show an increase in tic disorder, anxiety and disturbance of conduct by odds ratios of: 1.55 (95%CI: 1.23-1.96); 1.34 (95%CI: 1.05-1.70); and 1.34 (95%CI: 1.08-1.66) respectively in children up to the age of 10 years. Furthermore, a non-significant increased trend was found for ADHD (314) and disturbance of emotions (313). This is the first study reporting an association between long-term neurodevelopmental adverse effects and early use of hydroxyzine. Controlled studies are required in order to prove a causal relationship and to confirm the safety of hydroxyzine in the pediatric population. For the time being, we suggest the shortest possible duration for hydroxyzine use in preschool-age children.
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Affiliation(s)
- Hans J Gober
- Division of Translational Therapeutics, Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.,Department of Pharmacy, Kepler University Hospital, Linz, Austria
| | - Kathy H Li
- Therapeutic Evaluation Unit, Provincial Health Services Authority, Vancouver, BC, Canada.,Pharmaceutical Outcomes Programme, BC Children's Hospital, Vancouver, BC, Canada
| | - Kevin Yan
- Division of Translational Therapeutics, Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Anthony J Bailey
- Department of Psychiatry, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Bruce C Carleton
- Division of Translational Therapeutics, Department of Pediatrics, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.,Therapeutic Evaluation Unit, Provincial Health Services Authority, Vancouver, BC, Canada.,Pharmaceutical Outcomes Programme, BC Children's Hospital, Vancouver, BC, Canada.,BC Children's Hospital Research Institute, Vancouver, BC, Canada
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17
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Jin H, Chen L, Li J, An X, Wu YP, Zhu L, Yi H, Li KH. Vertically stacked RGB LEDs with optimized distributed Bragg reflectors. Opt Lett 2020; 45:6671-6674. [PMID: 33325867 DOI: 10.1364/ol.408416] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 09/18/2020] [Indexed: 06/12/2023]
Abstract
The design and fabrication of a vertically stacked red-green-blue (RGB) light-emitting diode (LED) with novel, to the best of our knowledge, wavelength-selective distributed Bragg reflectors (DBRs) are demonstrated. The two DBRs are optimized to achieve selective reflectance in the RGB spectral region through theoretical calculations and simulation modeling. The insertion of optimal DBRs into the stack structure can effectively reflect downward emission from the upper chip without filtering the emission from the lower chips, thereby increasing the luminous efficiency for white emission with a color temperature range of 3000-8000 K by 1.6-7.4%. The optical performances of stacked devices with and without DBRs are thoroughly studied, verifying the effectiveness of the proposed wavelength-selective DBR structure.
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18
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Abstract
Photo-plethysmography (PPG) making use of a monochromic light source and a photoelectric sensor is a non-invasive detection method to record blood volume changes in vessels and can be used to extract cardiac-related heart pulse information. Here, we demonstrated the fabrication of a monolithic photonic chip by integrating light-emitting diodes (LEDs) with photodetectors (PDs) on the same GaN-on-sapphire wafer containing InGaN/GaN multi-quantum wells (MQWs). The MQWs simultaneously act as light emitters in the LEDs and detectors in the PDs, and their mechanism has been studied. The fabricated chip operating in reflection mode is flip-chip bonded on a flexible polydimethylsiloxane (PDMS) strip, enabling the sapphire surface in close contact with the skin. The optical and electrical properties of the LED and PD have been thoroughly characterized, confirming that the PDs using identical MQWs can detect the reflected light from the LEDs. By attaching the chip to the wrist, PPG heart pulse signals from the arterial blood flow can be obtained, thereby verifying the feasibility of the proposed monolithic chip.
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19
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Butler VJ, Salazar DA, Soriano-Castell D, Alves-Ferreira M, Dennissen FJA, Vohra M, Oses-Prieto JA, Li KH, Wang AL, Jing B, Li B, Groisman A, Gutierrez E, Mooney S, Burlingame AL, Ashrafi K, Mandelkow EM, Encalada SE, Kao AW. Tau/MAPT disease-associated variant A152T alters tau function and toxicity via impaired retrograde axonal transport. Hum Mol Genet 2020; 28:1498-1514. [PMID: 30590647 PMCID: PMC6489414 DOI: 10.1093/hmg/ddy442] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [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: 08/29/2018] [Revised: 11/19/2018] [Accepted: 12/17/2018] [Indexed: 12/17/2022] Open
Abstract
Mutations in the microtubule-associated protein tau (MAPT) underlie multiple neurodegenerative disorders, yet the pathophysiological mechanisms are unclear. A novel variant in MAPT resulting in an alanine to threonine substitution at position 152 (A152T tau) has recently been described as a significant risk factor for both frontotemporal lobar degeneration and Alzheimer’s disease. Here we use complementary computational, biochemical, molecular, genetic and imaging approaches in Caenorhabditis elegans and mouse models to interrogate the effects of the A152T variant on tau function. In silico analysis suggests that a threonine at position 152 of tau confers a new phosphorylation site. This finding is borne out by mass spectrometric survey of A152T tau phosphorylation in C. elegans and mouse. Optical pulse-chase experiments of Dendra2-tau demonstrate that A152T tau and phosphomimetic A152E tau exhibit increased diffusion kinetics and the ability to traverse across the axon initial segment more efficiently than wild-type (WT) tau. A C. elegans model of tauopathy reveals that A152T and A152E tau confer patterns of developmental toxicity distinct from WT tau, likely due to differential effects on retrograde axonal transport. These data support a role for phosphorylation of the variant threonine in A152T tau toxicity and suggest a mechanism involving impaired retrograde axonal transport contributing to human neurodegenerative disease.
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Affiliation(s)
- Victoria J Butler
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA, USA
| | - Dominique A Salazar
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA, USA
| | - David Soriano-Castell
- Departments of Molecular Medicine and Molecular and Cellular Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA, USA
| | - Miguel Alves-Ferreira
- Departments of Molecular Medicine and Molecular and Cellular Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA, USA.,Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal.,Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Frank J A Dennissen
- German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, Bonn, Germany.,MPI for Neurological Research, Hamburg Outstation, c/o Deutsches Elektronen-Synchrotron, Notkestrasse 85, Hamburg, Germany.,The Center of Advanced European Studies and Research, Ludwig-Erhard-Allee 2, Bonn, Germany
| | - Mihir Vohra
- Department of Physiology, University of California San Francisco, San Francisco, CA, USA
| | - Juan A Oses-Prieto
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, USA
| | - Kathy H Li
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, USA
| | - Austin L Wang
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA, USA
| | - Beibei Jing
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA, USA
| | - Biao Li
- The Buck Institute for Research on Aging, Novato, CA, USA
| | - Alex Groisman
- Department of Physics, University of California San Diego, La Jolla, CA, USA
| | - Edgar Gutierrez
- Department of Physics, University of California San Diego, La Jolla, CA, USA
| | - Sean Mooney
- The Buck Institute for Research on Aging, Novato, CA, USA
| | - Alma L Burlingame
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA, USA
| | - Kaveh Ashrafi
- Department of Physiology, University of California San Francisco, San Francisco, CA, USA
| | - Eva-Maria Mandelkow
- German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, Bonn, Germany.,MPI for Neurological Research, Hamburg Outstation, c/o Deutsches Elektronen-Synchrotron, Notkestrasse 85, Hamburg, Germany.,The Center of Advanced European Studies and Research, Ludwig-Erhard-Allee 2, Bonn, Germany
| | - Sandra E Encalada
- Departments of Molecular Medicine and Molecular and Cellular Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA, USA
| | - Aimee W Kao
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA, USA
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20
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Michaux KD, Hou K, Karakochuk CD, Whitfield KC, Ly S, Verbowski V, Stormer A, Porter K, Li KH, Houghton LA, Lynd LD, Talukder A, McLean J, Green TJ. Effect of enhanced homestead food production on anaemia among Cambodian women and children: A cluster randomized controlled trial. Matern Child Nutr 2019; 15 Suppl 3:e12757. [PMID: 31148398 PMCID: PMC6593652 DOI: 10.1111/mcn.12757] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 10/23/2018] [Accepted: 11/04/2018] [Indexed: 11/30/2022]
Abstract
There is inconsistent evidence on the efficacy of agriculture programmes at improving women and children's anaemia and nutritional status. The primary aim of this study was to evaluate the impact of a nutrition‐sensitive enhanced homestead food production (EHFP) programme on anaemia in women (18–45 years) and children (6–59 months) in rural Cambodia. Secondary outcomes were women's micronutrient status and women and children's anthropometry. In this cluster‐randomized controlled trial, 900 households from 90 villages (clusters) were randomized to either (a) home gardens and behaviour change communication (BCC) on nutrition, hygiene, women's empowerment, and marketing (EHFP); (b) home gardens plus fishponds and BCC (EHFP + F); or (c) control (no intervention). Haemoglobin concentration and anthropometry were measured in women and children at baseline and at 22 months. Venous blood samples were collected in a subset of women (n = 450) at baseline and at 22 months. Generalized linear mixed effect models with repeated measures were used to evaluate the difference across groups and the change from baseline to end of study. Ninety clusters, 552 women, and 754 children completed the trial. Compared with control, we found a statistically significant impact on anaemia prevalence in children (−14.0 percentage points; P = 0.02) and retinol binding protein concentrations in women (difference in difference: 0.34; P = 0.02) randomized to EHFP and EHFP + F groups, respectively. No other statistically significant effects on anaemia, nutritional biomarker concentrations, or anthropometry were observed. Future research is needed to examine longer term impacts of EHFP on anthropometry in women and children and into the nutritional causes of anaemia among children in Cambodia.
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Affiliation(s)
- Kristina D Michaux
- Food, Nutrition and Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kroeun Hou
- Helen Keller International, New York, NY, USA
| | - Crystal D Karakochuk
- Food, Nutrition and Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kyly C Whitfield
- Food, Nutrition and Health, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Applied Human Nutrition, Mount Saint Vincent University, Halifax, Nova Scotia, Canada
| | - Sokhoing Ly
- Helen Keller International, New York, NY, USA
| | - Vashti Verbowski
- Food, Nutrition and Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Ame Stormer
- Helen Keller International, New York, NY, USA
| | | | - Kathy H Li
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Lisa A Houghton
- Department of Human Nutrition, University of Otago, Dunedin, New Zealand
| | - Larry D Lynd
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada.,Centre for Health Evaluation and Outcome Sciences, Providence Health Research Institute, Vancouver, British Columbia, Canada
| | | | - Judy McLean
- Food, Nutrition and Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Timothy J Green
- Food, Nutrition and Health, University of British Columbia, Vancouver, British Columbia, Canada.,Department of Pediatrics and Reproductive Health, University of Adelaide, Adelaide, South Australia, Australia.,Healthy Mothers, Babies, Children Research Theme, South Australia Health and Medical Research Institute, Women's and Children's Hospital, Adelaide, South Australia, Australia
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21
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Li KH, Ho J, Xu Z, Lakhani I, Bazoukis G, Liu T, Wong WT, Cheng SH, Chan MTV, Gin T, Wong MCS, Wong I, Wu WKK, Zhang Q, Tse G. P5014The NPAC score for predicting survival after incident acute myocardial infarction. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz746.0192] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Risk stratification in acute myocardial infarction (AMI) is important for guiding clinical management. Current risk scores are mostly derived from clinical trials with stringent patient selection. We aimed to establish and evaluate a composite scoring system to predict short-term mortality after index episodes of AMI, independent of electrocardiography (ECG) pattern, in a large real-world cohort.
Methods
Using electronic health records, patients admitted to our regional teaching hospital (derivation cohort, n=2127) and an independent tertiary care center (validation cohort, n=1276) with index acute myocardial infarction between January 2013 and December 2017 as confirmed by principal diagnosis and laboratory findings, were identified retrospectively.
Results
Univariate logistic regression was used as the primary model to identify potential contributors to mortality. Stepwise forward likelihood ratio logistic regression revealed that neutrophil-to-lymphocyte ratio, peripheral vascular disease, age, and serum creatinine (NPAC) were significant predictors for 90-day mortality (Hosmer-Lemeshow test, P=0.21). Each component of the NPAC score was weighted by beta-coefficients in multivariate analysis. The C-statistic of the NPAC score was 0.75, which was higher than the conventional Charlson's score (C-statistic=0.63). Application of a deep learning model to our dataset improved the accuracy of classification with a C-statistic of 0.81.
Multivariate binary logistic regression Variable β Adjusted Odds ratio (95% CI) P-value Points Age ≥65 years 1.304 3.68 (2.63–5.17) <0.001 2 Peripheral vascular disease 1.109 3.03 (1.52–6.04) 0.002 2 NLRt ≥9.51 1.100 2.73 (2.12–3.51) <0.001 1 Creatinine≥109 μmol/L 1.003 3.00 (2.35–3.85) <0.001 2
NPAC deep learning model
Conclusions
The NPAC score comprised of four items from routine laboratory parameters and basic clinical information and can facilitate early identification of cases at risk of short-term mortality following index myocardial infarction. Deep learning model can serve as a gate-keeper to provide more accurate prediction to facilitate clinical decision making.
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Affiliation(s)
- K H Li
- Newcastle University, Newcastle upon Tyne, United Kingdom
| | - J Ho
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Z Xu
- The Chinese University of Hong Kong, Institute of Digestive Disease, Li Ka Shing Institute of Health Sciences, Hong Kong, Hong Kong
| | - I Lakhani
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - G Bazoukis
- Evangelismos General Hospital of Athens, Cardiology, Athens, Greece
| | - T Liu
- 2nd Hospital of Tianjin Medical University, Cardiology, Tianjin, China
| | - W T Wong
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - S H Cheng
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - M T V Chan
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - T Gin
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - M C S Wong
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - I Wong
- The University of Hong Kong, Hong Kong, Hong Kong
| | - W K K Wu
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Q Zhang
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - G Tse
- The Chinese University of Hong Kong, Shatin, Hong Kong
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22
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Li KH, Sang T, Chan CP, Gong M, Li G, Liu T, Wu WKK, Chan M, Tse G, Xia Y, Ho J. P2838The impact of anesthesia depth on catheter ablation for atrial fibrillation: a systematic review and meta-analysis of observational studies. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz748.1148] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Objectives
This meta-analysis and systematic review seeks to compare both characteristic parameters and procedural outcomes of catheter ablation in patients under GA/deep sedation and mild/moderate sedation.
Background
Catheter ablation has become a widely applied intervention for treating symptomatic AF and arrhythmias that are refractory to medical therapy. It can be conducted through from mild sedation to general anesthesia.
Methods
PubMed and Embase were searched up to July 2018 for randomized controlled trials, cohort and observational studies that assessed the outcomes of catheter ablation under GA/deep sedation or mild/moderate sedation. 12 studies were included in this meta-analysis after screening with the inclusion and exclusion criteria. Heterogeneity between studies and publication bias was evaluated by I2 index and Egger's regression, respectively.
Results
Our meta-analysis found catheter AF ablation with GA/deep sedation to be associated with reduced risk of recurrence (RR: 0.79, 95% CI: 0.56 to 1.13, P=0.20) and complications (RR: 0.95, 95% CI: 0.64 to 1.42, P=0.82), though statistically insignificant. In terms of procedural parameters, there was non-significant difference between the two groups when both procedural time (SMD: −0.13, 95% CI: −0.90 to 0.63, P=0.74) and fluoroscopy time (SMD: −0.41, 95% CI: −1.40 to 0.58, P=0.41) were considered. Multivariate meta-regression demonstrated hypertension as an independent moderating factor for complication risk.
Complications Comparison
Conclusion
Apart from an increased likelihood of procedural success, ablation by GA/deep sedation was found to be non-significantly different from the mild/moderate sedation approach in both procedural parameters and outcome measures.
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Affiliation(s)
- K H Li
- Newcastle University, Newcastle upon Tyne, United Kingdom
| | - T Sang
- University of Toronto, Toronto, Canada
| | - C P Chan
- University of Manchester, Manchester, United Kingdom
| | - M Gong
- 2nd Hospital of Tianjin Medical University, Cardiology, Tianjin, China
| | - G Li
- 2nd Hospital of Tianjin Medical University, Cardiology, Tianjin, China
| | - T Liu
- 2nd Hospital of Tianjin Medical University, Cardiology, Tianjin, China
| | - W K K Wu
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - M Chan
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - G Tse
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Y Xia
- The Chinese University of Hong Kong, Shatin, Hong Kong
| | - J Ho
- The Chinese University of Hong Kong, Shatin, Hong Kong
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23
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Gleason CE, Oses-Prieto JA, Li KH, Saha B, Situ G, Burlingame AL, Pearce D. Phosphorylation at distinct subcellular locations underlies specificity in mTORC2-mediated activation of SGK1 and Akt. J Cell Sci 2019; 132:jcs.224931. [PMID: 30837283 DOI: 10.1242/jcs.224931] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [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: 09/07/2018] [Accepted: 02/21/2019] [Indexed: 02/04/2023] Open
Abstract
mTORC2 lies at the intersection of signaling pathways that control metabolism and ion transport through phosphorylation of the AGC-family kinases, the Akt and SGK1 proteins. How mTORC2 targets these functionally distinct downstream effectors in a context-specific manner is not known. Here, we show that the salt- and blood pressure-regulatory hormone, angiotensin II (AngII) stimulates selective mTORC2-dependent phosphorylation of SGK1 (S422) but not Akt (S473 and equivalent sites). Conventional PKC (cPKC), a critical mediator of the angiotensin type I receptor (AT1R, also known as AGTR1) signaling, regulates the subcellular localization of SIN1 (also known as MAPKAP1) and SGK1. Inhibition of cPKC catalytic activity disturbs SIN1 and SGK1 subcellular localization, re-localizing them from the nucleus and a perinuclear compartment to the plasma membrane in advance of hormonal stimulation. Surprisingly, pre-targeting of SIN1 and SGK1 to the plasma membrane prevents SGK1 S422 but not Akt S473 phosphorylation. Additionally, we identify three sites on SIN1 (S128, S315 and S356) that are phosphorylated in response to cPKC activation. Collectively, these data demonstrate that SGK1 activation occurs at a distinct subcellular compartment from that of Akt and suggests a mechanism for the selective activation of these functionally distinct mTORC2 targets through subcellular partitioning of mTORC2 activity.
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Affiliation(s)
- Catherine E Gleason
- Department of Medicine, Division of Nephrology, UCSF, San Francisco, CA 94143, USA
| | - Juan A Oses-Prieto
- Departments of Chemistry and Pharmaceutical Chemistry, UCSF, San Francisco, CA 94143, USA
| | - Kathy H Li
- Departments of Chemistry and Pharmaceutical Chemistry, UCSF, San Francisco, CA 94143, USA
| | - Bidisha Saha
- Department of Medicine, Division of Nephrology, UCSF, San Francisco, CA 94143, USA
| | - Gavin Situ
- Department of Medicine, Division of Nephrology, UCSF, San Francisco, CA 94143, USA
| | - Alma L Burlingame
- Departments of Chemistry and Pharmaceutical Chemistry, UCSF, San Francisco, CA 94143, USA
| | - David Pearce
- Department of Medicine, Division of Nephrology, UCSF, San Francisco, CA 94143, USA
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24
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Rizzardo S, Bansback N, Dragojlovic N, Douglas C, Li KH, Mitton C, Marra C, Blanis L, Lynd LD. Evaluating Canadians' Values for Drug Coverage Decision Making. Value Health 2019; 22:362-369. [PMID: 30832975 DOI: 10.1016/j.jval.2018.08.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [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: 03/14/2018] [Revised: 08/14/2018] [Accepted: 08/15/2018] [Indexed: 05/28/2023]
Abstract
BACKGROUND Decision makers are facing growing challenges in prioritizing drugs for reimbursement because of soaring drug costs and increasing pressures on financial resources. In addition to cost and effectiveness, payers are using other values to dictate which drugs are prioritized for funding, yet there are limited data on the Canadian public's priorities. OBJECTIVES To measure the relative societal importance of values considered most relevant in informing drug reimbursement decisions in a representative sample of Canadians. METHODS An online survey of 2539 Canadians aged 19 years and older was performed in which 13 values used in drug funding prioritization were ranked and then weighted using an analytic hierarchy process. RESULTS Canadians value safe and efficacious drugs that have certainty of evidence. The values ranked in the top 5 by most of our subjects were potential effect on quality of life (65.4%), severity of the disease (62.6%), ability of drug to work (61.1%), safety (60.5%), and potential to extend life (49.4%). Values related to patient or disease characteristics such as rarity, socioeconomic status, and health and lifestyle choices held the lowest rankings and weights. CONCLUSIONS Canadians value, above all, treatment-related factors (eg, efficacy and safety) and disease-related factors (eg, severity and equity). Decision makers are currently using additional justifications to prioritize drugs for reimbursement, such as rarity and unmet need, which were not found to be highly valued by Canadians. Decision makers should integrate the public's values into a Canadian reimbursement framework for prioritization of drugs competing for limited funds.
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Affiliation(s)
- Shirin Rizzardo
- Pharmaceutical Services Division, British Columbia Ministry of Health, Victoria, BC, Canada
| | - Nick Bansback
- Faculty of Medicine, School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada; Centre for Health Evaluation and Outcome Sciences, Providence Health Care Research Institute, Vancouver, BC, Canada
| | - Nick Dragojlovic
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Conor Douglas
- Department of Science and Technology Studies, York University, Toronto, ON, Canada
| | - Kathy H Li
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Craig Mitton
- Faculty of Medicine, School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada; Centre for Clinical Epidemiology and Evaluation, Vancouver Coastal Health Research Institute, Vancouver, BC, Canada
| | - Carlo Marra
- National School of Pharmacy, University of Otago, Dunedin, New Zealand
| | - Litsa Blanis
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Larry D Lynd
- Centre for Health Evaluation and Outcome Sciences, Providence Health Care Research Institute, Vancouver, BC, Canada; Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada.
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25
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Han TW, Ye W, Bethel NP, Zubia M, Kim A, Li KH, Burlingame AL, Grabe M, Jan YN, Jan LY. Chemically induced vesiculation as a platform for studying TMEM16F activity. Proc Natl Acad Sci U S A 2019; 116:1309-1318. [PMID: 30622179 PMCID: PMC6347726 DOI: 10.1073/pnas.1817498116] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [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: 01/10/2023] Open
Abstract
Calcium-activated phospholipid scramblase mediates the energy-independent bidirectional translocation of lipids across the bilayer, leading to transient or, in the case of apoptotic scrambling, sustained collapse of membrane asymmetry. Cells lacking TMEM16F-dependent lipid scrambling activity are deficient in generation of extracellular vesicles (EVs) that shed from the plasma membrane in a Ca2+-dependent manner, namely microvesicles. We have adapted chemical induction of giant plasma membrane vesicles (GPMVs), which require both TMEM16F-dependent phospholipid scrambling and calcium influx, as a kinetic assay to investigate the mechanism of TMEM16F activity. Using the GPMV assay, we identify and characterize both inactivating and activating mutants that elucidate the mechanism for TMEM16F activation and facilitate further investigation of TMEM16F-mediated lipid translocation and its role in extracellular vesiculation.
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Affiliation(s)
- Tina W Han
- Howard Hughes Medical Institute, University of California, San Francisco, CA 94143
- Department of Physiology, University of California, San Francisco, CA 94143
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143
| | - Wenlei Ye
- Howard Hughes Medical Institute, University of California, San Francisco, CA 94143
- Department of Physiology, University of California, San Francisco, CA 94143
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143
| | - Neville P Bethel
- Department of Pharmaceutical Chemistry, Cardiovascular Research Institute, University of California, San Francisco, CA 94143
| | - Mario Zubia
- Howard Hughes Medical Institute, University of California, San Francisco, CA 94143
- Department of Physiology, University of California, San Francisco, CA 94143
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143
| | - Andrew Kim
- Howard Hughes Medical Institute, University of California, San Francisco, CA 94143
- Department of Physiology, University of California, San Francisco, CA 94143
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143
| | - Kathy H Li
- Mass Spectrometry Facility, University of California, San Francisco, CA 94143
| | - Alma L Burlingame
- Mass Spectrometry Facility, University of California, San Francisco, CA 94143
| | - Michael Grabe
- Department of Pharmaceutical Chemistry, Cardiovascular Research Institute, University of California, San Francisco, CA 94143
| | - Yuh Nung Jan
- Howard Hughes Medical Institute, University of California, San Francisco, CA 94143
- Department of Physiology, University of California, San Francisco, CA 94143
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143
| | - Lily Y Jan
- Howard Hughes Medical Institute, University of California, San Francisco, CA 94143;
- Department of Physiology, University of California, San Francisco, CA 94143
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143
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26
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Gobis B, Kapanen AI, Reardon J, Min J, Li KH, Lynd LD, Zed PJ. Cardiovascular Risk Reduction in the Workplace With CAMMPUS (Cardiovascular Assessment and Medication Management by Pharmacists at the UBC Site). Ann Pharmacother 2019; 53:574-580. [DOI: 10.1177/1060028018823330] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Background: Cardiovascular (CV) disease is a leading cause of death despite being largely preventable. Employers increasingly offer preventive health programs in the workplace, and pharmacists are well suited to provide these programs. Objective: To evaluate the impact of a pharmacist-led service on CV risk in University of British Columbia (UBC) employees. Methods: This was a prospective observational pre-and-post design study, with participants as their own controls. Employees >18 years of age in the UBC health plan with a Framingham Risk Score (FRS) ≥10% or ≥1 medication-modifiable CV risk factor were included. Participants received a baseline assessment, individualized consultation for 12 months, and a final assessment by a pharmacist at the UBC Pharmacists Clinic. The primary end point was FRS reduction. Results: Baseline assessment of 512 participants between September 2015 and October 2016 yielded 207 (40%) participants, of whom 178 (86%) completed the 12-month intervention. Participants were 54% female and 55% Caucasian, with an average age of 51 (SD = 9.1) years. FRS at baseline was <10 in 45.8%, 10 to 19.9 in 37.9%, and ≥20 in 16.4% of participants. Over 12 months, significant reductions in average FRS (from 11.7 [SD = 7.7] to 10.7 [SD = 7.3]; P = 0.0017) and other parameters were observed. Significant improvements in quality of life (EQ5D change of 0.031 [95% CI = 0.001, 0.062] P = 0.023) and medication adherence (MMAS-8 change of 0.42 [ P = 0.019]) were also noted. Conclusions and Relevance: UBC employees had improvements in health markers, self-reported quality of life, and medication adherence after receiving a 12-month pharmacist-led intervention. Pharmacists are encouraged to provide CV risk reduction services in workplaces.
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Affiliation(s)
- Barbara Gobis
- The University of British Columbia, Vancouver, BC, Canada
| | | | | | - Jason Min
- The University of British Columbia, Vancouver, BC, Canada
| | - Kathy H. Li
- The University of British Columbia, Vancouver, BC, Canada
| | - Larry D. Lynd
- The University of British Columbia, Vancouver, BC, Canada
| | - Peter J. Zed
- The University of British Columbia, Vancouver, BC, Canada
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27
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Nayak A, Kim DY, Trnka MJ, Kerr CH, Lidsky PV, Stanley DJ, Rivera BM, Li KH, Burlingame AL, Jan E, Frydman J, Gross JD, Andino R. A Viral Protein Restricts Drosophila RNAi Immunity by Regulating Argonaute Activity and Stability. Cell Host Microbe 2018; 24:542-557.e9. [PMID: 30308158 PMCID: PMC6450077 DOI: 10.1016/j.chom.2018.09.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [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: 01/16/2018] [Revised: 07/13/2018] [Accepted: 09/10/2018] [Indexed: 11/30/2022]
Abstract
The dicistrovirus, Cricket paralysis virus (CrPV) encodes an RNA interference (RNAi) suppressor, 1A, which modulates viral virulence. Using the Drosophila model, we combined structural, biochemical, and virological approaches to elucidate the strategies by which CrPV-1A restricts RNAi immunity. The atomic resolution structure of CrPV-1A uncovered a flexible loop that interacts with Argonaute 2 (Ago-2), thereby inhibiting Ago-2 endonuclease-dependent immunity. Mutations disrupting Ago-2 binding attenuates viral pathogenesis in wild-type but not Ago-2-deficient flies. CrPV-1A also contains a BC-box motif that enables the virus to hijack a host Cul2-Rbx1-EloBC ubiquitin ligase complex, which promotes Ago-2 degradation and virus replication. Our study uncovers a viral-based dual regulatory program that restricts antiviral immunity by direct interaction with and modulation of host proteins. While the direct inhibition of Ago-2 activity provides an efficient mechanism to establish infection, the recruitment of a ubiquitin ligase complex enables CrPV-1A to amplify Ago-2 inactivation to restrict further antiviral RNAi immunity.
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Affiliation(s)
- Arabinda Nayak
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94158, USA; Department of Biology and Genetics, Stanford University, Stanford, CA 94305, USA
| | - Dong Young Kim
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA; College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 38541, South Korea
| | - Michael J Trnka
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA
| | - Craig H Kerr
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Peter V Lidsky
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94158, USA
| | - David J Stanley
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA
| | - Brianna Monique Rivera
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Kathy H Li
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA
| | - Alma L Burlingame
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA
| | - Eric Jan
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Judith Frydman
- Department of Biology and Genetics, Stanford University, Stanford, CA 94305, USA
| | - John D Gross
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA
| | - Raul Andino
- Department of Microbiology and Immunology, University of California San Francisco, San Francisco, CA 94158, USA.
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Park Y, Li KH, Fu WY, Cheung YF, Choi HW. Packaging of InGaN stripe-shaped light-emitting diodes. Appl Opt 2018; 57:2452-2458. [PMID: 29714220 DOI: 10.1364/ao.57.002452] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 02/26/2018] [Indexed: 06/08/2023]
Abstract
We demonstrate the fabrication of InGaN/GaN stripe-shaped light-emitting diodes (LEDs) in flip-chip packaging (FC-LED) and vertically mounted packaging (VM-LED). Compared to conventionally packaged LEDs, these packaging schemes enhance light output and emission divergence in ways favorable for general lighting applications. The FC-LED can sustain efficiency at high current operations due to effective heat sinking, while the VM-LED excels at light extraction efficiency due to the exposure of two large emission surfaces. Together with the properties of low luminous exitance and emission uniformity, the stripe-shaped LEDs are ideal for the assembly of luminaires. An LED light tube comprising a continuous linear array of 10 stripe-shaped LED chips has been assembled. The optical performance of the light tube is compared to another light tube assembled with conventional square-shaped LED chips (with and without external diffuser) by confocal microscopy. It is found that emission uniformity of the stripe-shaped LED tube is significantly improved, with a threefold increase in illumination area, without efficiency loss associated with diffusers.
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29
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Pang T, Guo XF, Zhou YH, Qiu XQ, Li S, Liang ZR, Qin XL, Li KH, Zeng XY. [Outcomes of pregnancy among women with alpha-thalassemia minor: A retrospective study of Pingguo county in Guangxi Zhuang Autonomous Region]. Zhonghua Liu Xing Bing Xue Za Zhi 2018; 38:1620-1623. [PMID: 29294574 DOI: 10.3760/cma.j.issn.0254-6450.2017.12.007] [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] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To investigate the association between the value of α-thalassemia minor and the outcomes in pregnant women. Methods: A total of 445 pregnant women with α-thalassemia minor were selected as thalassemia group in the Pingguo County Maternal and Child Health Hospital of Guangxi from January 2011 to December 2015, with ratio of 1∶4 healthy pregnant women was randomly recruited as non-thalassemia group. Clinical characteristics and pregnancy outcomes of the two groups were retrospectively analyzed using methods including t test, χ(2) test, and logistic regression model and ROC curve. Results: There were no significant differences noticed in factors as age, BMI, gestational age and educational level of the two groups. Hemoglobin of the thalassemia group was significantly lower than that of the non-thalassemia group (P<0.001). Differences on parity, ethnicities or occupation were statistically significant. Results from univariate analysis showed that the proportions of low birth weight, small for date infant and 1 min Apgar score<7 were higher in the thalassemia group, but the ratio of adverse pregnancy outcomes was comparable on parameters as preterm birth, stillbirth, macrosomia. Findings from the unconditional logistic regression showed that pregnancy complicated with α-thalassemia minor appeared a risk for both newborns with low birth weight (aOR=2.29, 95%CI: 1.32-3.95) and small for date infant (aOR= 2.11, 95%CI: 1.16-3.84). The ROC curve showed that α-thalassemia minor combined with multiple indicators presented a certain predictive value on neonatal birth weight. Conclusion: Pregnancy complicated with α-thalassemia minor was likely to increase the risk of birth weight loss in newborns, suggesting that prenatal care for pregnant women with thalassemia be strengthened, in order to reduce the incidence of adverse pregnancy outcomes.
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Affiliation(s)
- T Pang
- Department of Epidemiology and Health Statistic, School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - X F Guo
- Department of Epidemiology and Health Statistic, School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - Y H Zhou
- Department of Maternity, Pingguo County Child Health, Baise 531400, China
| | - X Q Qiu
- Department of Epidemiology and Health Statistic, School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - S Li
- Department of Epidemiology and Health Statistic, School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - Z R Liang
- Department of Epidemiology and Health Statistic, School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - X L Qin
- Department of Epidemiology and Health Statistic, School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - K H Li
- Department of Epidemiology and Health Statistic, School of Public Health, Guangxi Medical University, Nanning 530021, China
| | - X Y Zeng
- Department of Epidemiology and Health Statistic, School of Public Health, Guangxi Medical University, Nanning 530021, China
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Verbowski V, Talukder Z, Hou K, Sok Hoing L, Michaux K, Anderson V, Gibson R, Li KH, Lynd LD, McLean J, Green TJ, Barr SI. Effect of enhanced homestead food production and aquaculture on dietary intakes of women and children in rural Cambodia: A cluster randomized controlled trial. Matern Child Nutr 2018; 14:e12581. [PMID: 29314705 DOI: 10.1111/mcn.12581] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Revised: 11/17/2017] [Accepted: 11/27/2017] [Indexed: 01/16/2023]
Abstract
The Cambodian diet is low in nutrient-dense animal-source foods. Enhanced homestead food production (EHFP) and aquaculture, which increase availability of nutrient-dense foods, are promising interventions to improve dietary intake. This study examined the effect of EHFP with or without aquaculture on dietary intake and prevalence of inadequate intake of select nutrients among women and children living in rural Cambodia, compared to controls. In a registered, cluster randomized controlled trial in Prey Veng, Cambodia, 10 households in each of 90 villages (n = 900) were randomized by village to receive EHFP, EHFP plus aquaculture, or control. After 22-month intervention, 24-hr dietary recalls (24HRs) were collected from mothers aged 18-50 years (n = 429) and their children aged 6 months-7 years (n = 421), reported by their mothers. Usual intake distributions (generated using 24HRs and repeat 24HRs on a subsample) were used to estimate prevalence of inadequate intake. Compared to controls, women in the EHFP group had significantly higher zinc (+1.0 mg/d) and Vitamin A (+139 retinol activity equivalents/d) intakes, and women in the EHFP plus aquaculture group had significantly higher iron (+2.7 mg/d), Vitamin A (+191 retinol activity equivalents/d), and riboflavin (+0.17 mg/d) intakes. Women in the EHFP plus aquaculture group also had significantly lower prevalence of inadequate iron (-7%, at 10% bioavailability), Vitamin A (-19%), and riboflavin (-17%) intakes, compared to controls. No significant differences in intakes or nutrient adequacy were observed among children or between EHFP and EHFP plus aquaculture groups. The biological importance of the small differences in nutrient intakes among women remains to be established.
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Affiliation(s)
- Vashti Verbowski
- Faculty of Land and Food Systems, Department of Human Nutrition, University of British Columbia, Vancouver, British Columbia, Canada
| | - Zaman Talukder
- Helen Keller International, Cambodia, Phnom Penh, Cambodia
| | - Kroeun Hou
- Helen Keller International, Cambodia, Phnom Penh, Cambodia
| | - Ly Sok Hoing
- Helen Keller International, Cambodia, Phnom Penh, Cambodia
| | - Kristina Michaux
- Faculty of Land and Food Systems, Department of Human Nutrition, University of British Columbia, Vancouver, British Columbia, Canada
| | - Victoria Anderson
- Department of Human Nutrition, University of Otago, Dunedin, New Zealand
| | - Rosalind Gibson
- Department of Human Nutrition, University of Otago, Dunedin, New Zealand
| | - Kathy H Li
- Collaboration for Outcomes Research and Evaluation, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada.,Centre for Health Evaluation and Outcome Sciences, Providence Health Research Institute, Vancouver, BC, Canada
| | - Larry D Lynd
- Collaboration for Outcomes Research and Evaluation, Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada.,Centre for Health Evaluation and Outcome Sciences, Providence Health Research Institute, Vancouver, BC, Canada
| | - Judy McLean
- Faculty of Land and Food Systems, Department of Human Nutrition, University of British Columbia, Vancouver, British Columbia, Canada
| | - Tim J Green
- Faculty of Land and Food Systems, Department of Human Nutrition, University of British Columbia, Vancouver, British Columbia, Canada.,Healthy Mothers, Babies, and Children Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia.,Discipline of Paediatrics, University of Adelaide, Adelaide, South Australia, Australia
| | - Susan I Barr
- Faculty of Land and Food Systems, Department of Human Nutrition, University of British Columbia, Vancouver, British Columbia, Canada
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31
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Hao ZQ, Liu L, Shen M, Yang XY, Li KH, Guo LB, Li XY, Lu YF, Zeng XY. Investigation on self-absorption at reduced air pressure in quantitative analysis using laser-induced breakdown spectroscopy. Opt Express 2016; 24:26521-26528. [PMID: 27857385 DOI: 10.1364/oe.24.026521] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The self-absorption at reduced air pressure for quantitative analysis of Mn and Cu elements in steel using laser-induced breakdown spectroscopy was investigated. The calibration curves of Mn and Cu elements at the air pressures of 100, 80, 50, 20, and 1 kPa were studied. The results show that, the nonlinearity of calibration curves which caused by self-absorption effects at atmosphere could be significantly improved by reducing the air pressure to 1 kPa, and the coefficients of determination (R2) of linear calibration curves of Mn and Cu lines are all higher than 0.99. The further study explored that the reason for the improvement was that the induced plasma became low density and the self-absorption coefficient was close to 1 when the air pressure reduced to 1 kPa.
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Abstract
The majority of a GaN light-emitting diode (LED) is released from its sapphire substrate through selective-area laser lift-off to form a freely suspended light emitter. By virtue of being suspended in air without supporting substrates, the ultrathin crystalline and crack-free film possesses flexibility and bendability. The free-standing LEDs benefit from significant relaxation of strain, evident from red-shifting of the E2(high) phonon frequencies as measured by Raman spectroscopy toward those of strain-free free-standing GaN substrates. The phonon frequencies remain invariant upon bending of the film; this indicates that the properties of the flexible device will not be dependent on the bending curvatures. The observation of pronounced spectral blue-shifts from the photoluminescence (PL) spectrum from the flexible regions further confirms the occurrence of strain relaxation in the quantum wells. Being free-standing and thus lacking a direct heat-sinking pathway, emissions from the different regions of the suspended film can be affected by thermal effects to different extents, which are investigated by long-wave infrared thermometry. Heat accumulation is determined to be most severe at the far end of the flexible stripe at higher currents, leading to reduced efficiencies and electroluminescence (EL) spectral red-shifts. Based on this architecture, a monolithic 3 × 4 dot-matrix microdisplay prototype is demonstrated, comprising three adjacent flexible stripe emitters with four individually addressable pixels on each stripe. This proof-of-concept demonstration opens up new opportunities for GaN optoelectronics for a wide range of flexible display and visual applications.
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Affiliation(s)
- Y F Cheung
- Department of Electrical and Electronic Engineering, The University of Hong Kong , Pokfulam Road, Hong Kong
| | - K H Li
- Department of Electrical and Electronic Engineering, The University of Hong Kong , Pokfulam Road, Hong Kong
| | - H W Choi
- Department of Electrical and Electronic Engineering, The University of Hong Kong , Pokfulam Road, Hong Kong
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Lee S, Shang Y, Redmond SA, Urisman A, Tang AA, Li KH, Burlingame AL, Pak RA, Jovičić A, Gitler AD, Wang J, Gray NS, Seeley WW, Siddique T, Bigio EH, Lee VMY, Trojanowski JQ, Chan JR, Huang EJ. Activation of HIPK2 Promotes ER Stress-Mediated Neurodegeneration in Amyotrophic Lateral Sclerosis. Neuron 2016; 91:41-55. [PMID: 27321923 DOI: 10.1016/j.neuron.2016.05.021] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2015] [Revised: 02/16/2016] [Accepted: 05/04/2016] [Indexed: 12/13/2022]
Abstract
Persistent accumulation of misfolded proteins causes endoplasmic reticulum (ER) stress, a prominent feature in many neurodegenerative diseases including amyotrophic lateral sclerosis (ALS). Here we report the identification of homeodomain interacting protein kinase 2 (HIPK2) as the essential link that promotes ER-stress-induced cell death via the IRE1α-ASK1-JNK pathway. ER stress, induced by tunicamycin or SOD1(G93A), activates HIPK2 by phosphorylating highly conserved serine and threonine residues (S359/T360) within the activation loop of the HIPK2 kinase domain. In SOD1(G93A) mice, loss of HIPK2 delays disease onset, reduces cell death in spinal motor neurons, mitigates glial pathology, and improves survival. Remarkably, HIPK2 activation positively correlates with TDP-43 proteinopathy in NEFH-tTA/tetO-hTDP-43ΔNLS mice, sporadic ALS and C9ORF72 ALS, and blocking HIPK2 kinase activity protects motor neurons from TDP-43 cytotoxicity. These results reveal a previously unrecognized role of HIPK2 activation in ER-stress-mediated neurodegeneration and its potential role as a biomarker and therapeutic target for ALS. VIDEO ABSTRACT.
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Affiliation(s)
- Sebum Lee
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Yulei Shang
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Stephanie A Redmond
- Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA; Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Anatoly Urisman
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Amy A Tang
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Kathy H Li
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Alma L Burlingame
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Ryan A Pak
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Ana Jovičić
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Aaron D Gitler
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jinhua Wang
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School & Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Nathanael S Gray
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School & Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - William W Seeley
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Teepu Siddique
- Division of Neuromuscular Medicine and Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Eileen H Bigio
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Virginia M-Y Lee
- Department of Pathology and Laboratory Medicine, Center for Neurodegenerative Disease Research, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - John Q Trojanowski
- Department of Pathology and Laboratory Medicine, Center for Neurodegenerative Disease Research, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Jonah R Chan
- Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA; Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Eric J Huang
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 94158, USA; Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA; Pathology Service 113B, VA Medical Center, San Francisco, CA 94121, USA.
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Yang XY, Hao ZQ, Li CM, Li JM, Yi RX, Shen M, Li KH, Guo LB, Li XY, Lu YF, Zeng XY. Sensitive determinations of Cu, Pb, Cd, and Cr elements in aqueous solutions using chemical replacement combined with surface-enhanced laser-induced breakdown spectroscopy. Opt Express 2016; 24:13410-13417. [PMID: 27410358 DOI: 10.1364/oe.24.013410] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In this study, chemical replacement combined with surface-enhanced laser-induced breakdown spectroscopy (CR-SENLIBS) was for the first time applied to improve the detection sensitivities of trace heavy metal elements in aqueous solutions. Utilizing chemical replacement effect, heavy metal ions in aqueous solution were enriched on the magnesium alloy surface as a solid replacement layer through reacting with the high chemical activity metallic magnesium (Mg) within 1 minute. Unitary and mixed solutions with Cu, Pb, Cd, and Cr elements were prepared to construct calibration curves, respectively. The CR-SENLIBS showed a much better detection sensitivity and accuracy for both unitary and mixed solutions. The coefficients of determination R2 of the calibration curves were above 0.96, and the LoDs were of the same order of magnitude, i.e., in the range of 0.016-0.386 μg/mL for the unitary solution, and in the range of 0.025-0.420 μg/mL for the mixed solution. These results show that CR-SENLIBS is a feasible method for improving the detection sensitivity of trace element in liquid sample, which definitely provides a way for wider application of LIBS in water quality monitoring.
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Wei CQ, Chien CW, Ai LF, Zhao J, Zhang Z, Li KH, Burlingame AL, Sun Y, Wang ZY. The Arabidopsis B-box protein BZS1/BBX20 interacts with HY5 and mediates strigolactone regulation of photomorphogenesis. J Genet Genomics 2016; 43:555-563. [PMID: 27523280 DOI: 10.1016/j.jgg.2016.05.007] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [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: 05/06/2016] [Revised: 05/20/2016] [Accepted: 05/23/2016] [Indexed: 10/21/2022]
Abstract
Plant growth is controlled by integration of hormonal and light-signaling pathways. BZS1 is a B-box zinc finger protein previously characterized as a negative regulator in the brassinosteroid (BR)-signaling pathway and a positive regulator in the light-signaling pathway. However, the mechanisms by which BZS1/BBX20 integrates light and hormonal pathways are not fully understood. Here, using a quantitative proteomic workflow, we identified several BZS1-associated proteins, including light-signaling components COP1 and HY5. Direct interactions of BZS1 with COP1 and HY5 were verified by yeast two-hybrid and co-immunoprecipitation assays. Overexpression of BZS1 causes a dwarf phenotype that is suppressed by the hy5 mutation, while overexpression of BZS1 fused with the SRDX transcription repressor domain (BZS1-SRDX) causes a long-hypocotyl phenotype similar to hy5, indicating that BZS1's function requires HY5. BZS1 positively regulates HY5 expression, whereas HY5 negatively regulates BZS1 protein level, forming a feedback loop that potentially contributes to signaling dynamics. In contrast to BR, strigolactone (SL) increases BZS1 level, whereas the SL responses of hypocotyl elongation, chlorophyll and HY5 accumulation are diminished in the BZS1-SRDX seedlings, indicating that BZS1 is involved in these SL responses. These results demonstrate that BZS1 interacts with HY5 and plays a central role in integrating light and multiple hormone signals for photomorphogenesis in Arabidopsis.
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Affiliation(s)
- Chuang-Qi Wei
- Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Collaboration Innovation Center for Cell Signaling, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China; Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Chih-Wei Chien
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Lian-Feng Ai
- Hebei Entry-Exit Inspection and Quarantine Bureau of the People's Republic of China, Shijiazhuang 050051, China
| | - Jun Zhao
- Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Collaboration Innovation Center for Cell Signaling, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China
| | - Zhenzhen Zhang
- Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Collaboration Innovation Center for Cell Signaling, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China; Center of Basic Forestry and Proteomics, Haixia Institute of Science and Technology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Kathy H Li
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158, USA
| | - Alma L Burlingame
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158, USA
| | - Yu Sun
- Key Laboratory of Molecular and Cellular Biology of Ministry of Education, Hebei Collaboration Innovation Center for Cell Signaling, Hebei Key Laboratory of Molecular and Cellular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China.
| | - Zhi-Yong Wang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA.
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Lynd LD, Traboulsee A, Marra CA, Mittmann N, Evans C, Li KH, Carter M, Hategekimana C. Quantitative analysis of multiple sclerosis patients' preferences for drug treatment: a best-worst scaling study. Ther Adv Neurol Disord 2016; 9:287-96. [PMID: 27366235 DOI: 10.1177/1756285616648060] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND With recent developments in drug therapy for multiple sclerosis (MS), new treatment options have become available presenting patients with complex treatment decisions. OBJECTIVES The objective of this study was to elicit patients' preferences for different attributes of MS drug therapy. METHODS A representative sample of patients with MS across Canada (n=189) participated in a best-worst scaling study to quantify preferences for different attributes of MS drug therapy, including delaying progression, improving symptoms, preventing relapse, minor side effects, rare but serious adverse events (SAEs), and route of administration. Conditional logit models were fitted to estimate the relative importance of each attribute in influencing patients' preferences. RESULTS A latent-class analysis revealed heterogeneity of preferences across respondents, with preferences differing across five classes. The most important attributes of drug therapy were the avoidance of SAEs for three classes and the improvement of symptoms for two other classes. Only a smaller group of patients demonstrated a specific preference for avoiding SAEs, and route of administration. CONCLUSION This study shows that preferences for drug therapy among patients with MS are different, some of which can be explained by experiences with their disease and treatment. These findings can help to inform the focus of interactions that healthcare practitioners have with patients with MS, as well as further drug development.
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Affiliation(s)
- Larry D Lynd
- Faculty of Pharmaceutical Sciences, University of British Columbia, 2405 Wesbrook Mall, Vancouver, BC, Canada V6T 1Z3
| | - Anthony Traboulsee
- Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - Carlo A Marra
- School of Pharmacy, Memorial University of Newfoundland, St John's, Canada
| | | | - Charity Evans
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Canada
| | - Kathy H Li
- Collaboration for Outcomes Research and Evaluation, Faculty of Pharmaceutical Sciences, University of British Columbia, Canada
| | - Melanie Carter
- Collaboration for Outcomes Research and Evaluation, Faculty of Pharmaceutical Sciences, University of British Columbia, Canada
| | - Celestin Hategekimana
- Collaboration for Outcomes Research and Evaluation, Faculty of Pharmaceutical Sciences, University of British Columbia, Canada
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Portnoy V, Lin SHS, Li KH, Burlingame A, Hu ZH, Li H, Li LC. saRNA-guided Ago2 targets the RITA complex to promoters to stimulate transcription. Cell Res 2016; 26:320-35. [PMID: 26902284 PMCID: PMC4783471 DOI: 10.1038/cr.2016.22] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [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: 06/02/2015] [Revised: 10/22/2015] [Accepted: 01/12/2016] [Indexed: 12/21/2022] Open
Abstract
Small activating RNAs (saRNAs) targeting specific promoter regions are able to stimulate gene expression at the transcriptional level, a phenomenon known as RNA activation (RNAa). It is known that RNAa depends on Ago2 and is associated with epigenetic changes at the target promoters. However, the precise molecular mechanism of RNAa remains elusive. Using human CDKN1A (p21) as a model gene, we characterized the molecular nature of RNAa. We show that saRNAs guide Ago2 to and associate with target promoters. saRNA-loaded Ago2 facilitates the assembly of an RNA-induced transcriptional activation (RITA) complex, which, in addition to saRNA-Ago2 complex, includes RHA and CTR9, the latter being a component of the PAF1 complex. RITA interacts with RNA polymerase II to stimulate transcription initiation and productive elongation, accompanied by monoubiquitination of histone 2B. Our results establish the existence of a cellular RNA-guided genome-targeting and transcriptional activation mechanism and provide important new mechanistic insights into the RNAa process.
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Affiliation(s)
- Victoria Portnoy
- Department of Urology and Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94158, USA
| | - Szu Hua Sharon Lin
- Department of Urology and Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94158, USA
| | - Kathy H Li
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA
| | - Alma Burlingame
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, CA 94158, USA
| | - Zheng-Hui Hu
- Department of Urology and Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94158, USA
| | - Hao Li
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94158, USA
| | - Long-Cheng Li
- Department of Urology and Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94158, USA.,Laboratory of Molecular Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China
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Didonna A, Isobe N, Caillier SJ, Li KH, Burlingame AL, Hauser SL, Baranzini SE, Patsopoulos NA, Oksenberg JR. A non-synonymous single-nucleotide polymorphism associated with multiple sclerosis risk affects the EVI5 interactome. Hum Mol Genet 2015; 24:7151-8. [PMID: 26433934 DOI: 10.1093/hmg/ddv412] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 09/28/2015] [Indexed: 12/31/2022] Open
Abstract
Despite recent progress in the characterization of genetic loci associated with multiple sclerosis (MS) risk, the ubiquitous linkage disequilibrium operating across the genome has stalled efforts to distinguish causative variants from proxy single-nucleotide polymorphisms (SNPs). Here, we have identified through fine mapping and meta-analysis EVI5 as the most plausible disease risk gene within the 1p22.1 locus. We further show that an exonic SNP associated with risk induces changes in superficial hydrophobicity patterns of the coiled-coil domain of EVI5, which, in turns, affects the EVI5 interactome. Immunoprecipitation of wild-type and mutated EVI5 followed by mass spectrometry generated a roster of disease-specific interactors functionally linked to lipid metabolism. Among the exclusive binding partners of the risk variant, we describe the novel interaction with sphingosine 1-phosphate lyase (SGPL1)-a key enzyme for the creation of the sphingosine-1 phosphate gradient, which is relevant to the pathogenic process and therapeutic management of MS.
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Affiliation(s)
| | | | | | - Kathy H Li
- Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, CA 94158, USA
| | - Alma L Burlingame
- Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, CA 94158, USA
| | | | | | - Nikolaos A Patsopoulos
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA, Program in Translational NeuroPsychiatric Genomics, Department of Neurology, Institute for the Neurosciences and Division of Genetics, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02142, USA
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Li KH, Cheung YF, Choi HW. Whispering gallery mode lasing in optically isolated III-nitride nanorings. Opt Lett 2015; 40:2564-2567. [PMID: 26030558 DOI: 10.1364/ol.40.002564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
III-nitride nanorings fabricated from a combination of hybrid-nanosphere-lithography and laser lift-off processes is demonstrated. Being formed on an interfacial metallic layer optically coupling between the optical ring and its substrate is eliminated, maximizing optical confinement of whispering gallery resonant mode within the ring cavity. The tapered cross-sectional profile also promotes coupling of emitted light into resonant modes. Optically pumped lasing with a dominant peak at 421.5 nm is observed at room temperature, with threshold energy density of ∼6.5 mJ/cm2. Etch-induced sidewall roughness causes scattering of light at the interface to diminish confinement, and is also responsible for the mode-splitting effect according to finite-difference time-domain simulations.
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Muller M, Hutin S, Marigold O, Li KH, Burlingame A, Glaunsinger BA. A ribonucleoprotein complex protects the interleukin-6 mRNA from degradation by distinct herpesviral endonucleases. PLoS Pathog 2015; 11:e1004899. [PMID: 25965334 PMCID: PMC4428876 DOI: 10.1371/journal.ppat.1004899] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [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: 01/16/2015] [Accepted: 04/20/2015] [Indexed: 11/21/2022] Open
Abstract
During lytic Kaposi's sarcoma-associated herpesvirus (KSHV) infection, the viral endonuclease SOX promotes widespread degradation of cytoplasmic messenger RNA (mRNA). However, select mRNAs escape SOX-induced cleavage and remain robustly expressed. Prominent among these is interleukin-6 (IL-6), a growth factor important for survival of KSHV infected B cells. IL-6 escape is notable because it contains a sequence within its 3' untranslated region (UTR) that can confer protection when transferred to a SOX-targeted mRNA, and thus overrides the endonuclease targeting mechanism. Here, we pursued how this protective RNA element functions to maintain mRNA stability. Using affinity purification and mass spectrometry, we identified a set of proteins that associate specifically with the protective element. Although multiple proteins contributed to the escape mechanism, depletion of nucleolin (NCL) most severely impacted protection. NCL was re-localized out of the nucleolus during lytic KSHV infection, and its presence in the cytoplasm was required for protection. After loading onto the IL-6 3' UTR, NCL differentially bound to the translation initiation factor eIF4H. Disrupting this interaction, or depleting eIF4H, reinstated SOX targeting of the RNA, suggesting that interactions between proteins bound to distant regions of the mRNA are important for escape. Finally, we found that the IL-6 3' UTR was also protected against mRNA degradation by the vhs endonuclease encoded by herpes simplex virus, despite the fact that its mechanism of mRNA targeting is distinct from SOX. These findings highlight how a multitude of RNA-protein interactions can impact endonuclease targeting, and identify new features underlying the regulation of the IL-6 mRNA.
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Affiliation(s)
- Mandy Muller
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, United States of America
| | - Stephanie Hutin
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, United States of America
| | - Oliver Marigold
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, United States of America
| | - Kathy H. Li
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California, United States of America
| | - Al Burlingame
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, California, United States of America
| | - Britt A. Glaunsinger
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, United States of America
- Department of Cell and Molecular Biology, University of California, Berkeley, Berkeley, California, United States of America
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Hao ZQ, Li CM, Shen M, Yang XY, Li KH, Guo LB, Li XY, Lu YF, Zeng XY. Acidity measurement of iron ore powders using laser-induced breakdown spectroscopy with partial least squares regression. Opt Express 2015; 23:7795-7801. [PMID: 25837118 DOI: 10.1364/oe.23.007795] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Laser-induced breakdown spectroscopy (LIBS) with partial least squares regression (PLSR) has been applied to measuring the acidity of iron ore, which can be defined by the concentrations of oxides: CaO, MgO, Al₂O₃, and SiO₂. With the conventional internal standard calibration, it is difficult to establish the calibration curves of CaO, MgO, Al₂O₃, and SiO₂ in iron ore due to the serious matrix effects. PLSR is effective to address this problem due to its excellent performance in compensating the matrix effects. In this work, fifty samples were used to construct the PLSR calibration models for the above-mentioned oxides. These calibration models were validated by the 10-fold cross-validation method with the minimum root-mean-square errors (RMSE). Another ten samples were used as a test set. The acidities were calculated according to the estimated concentrations of CaO, MgO, Al₂O₃, and SiO₂ using the PLSR models. The average relative error (ARE) and RMSE of the acidity achieved 3.65% and 0.0048, respectively, for the test samples.
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Li KH, Liu X, Wang Q, Zhao S, Mi Z. Ultralow-threshold electrically injected AlGaN nanowire ultraviolet lasers on Si operating at low temperature. Nat Nanotechnol 2015; 10:140-4. [PMID: 25599190 DOI: 10.1038/nnano.2014.308] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 11/19/2014] [Indexed: 05/22/2023]
Abstract
Ultraviolet laser radiation has been adopted in a wide range of applications as diverse as water purification, flexible displays, data storage, sterilization, diagnosis and bioagent detection. Success in developing semiconductor-based, compact ultraviolet laser sources, however, has been extremely limited. Here, we report that defect-free disordered AlGaN core-shell nanowire arrays, formed directly on a Si substrate, can be used to achieve highly stable, electrically pumped lasers across the entire ultraviolet AII (UV-AII) band (∼320-340 nm) at low temperatures. The laser threshold is in the range of tens of amps per centimetre squared, which is nearly three orders of magnitude lower than those of previously reported quantum-well lasers. This work also reports the first demonstration of electrically injected AlGaN-based ultraviolet lasers monolithically grown on a Si substrate, and offers a new avenue for achieving semiconductor lasers in the ultraviolet B (UV-B) (280-320 nm) and ultraviolet C (UV-C) (<280 nm) bands.
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Affiliation(s)
- K H Li
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - X Liu
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - Q Wang
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - S Zhao
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9, Canada
| | - Z Mi
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, Quebec H3A 0E9, Canada
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Wang Q, Liu X, Kibria MG, Zhao S, Nguyen HPT, Li KH, Mi Z, Gonzalez T, Andrews MP. p-Type dopant incorporation and surface charge properties of catalyst-free GaN nanowires revealed by micro-Raman scattering and X-ray photoelectron spectroscopy. Nanoscale 2014; 6:9970-9976. [PMID: 25074362 DOI: 10.1039/c4nr01608d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Micro-Raman scattering and X-ray photoelectron spectroscopy were employed to investigate Mg-doped GaN nanowires. With the increase of Mg doping level, pronounced Mg-induced local vibrational modes were observed. The evolution of longitudinal optical phonon-plasmon coupled mode, together with detailed X-ray photoelectron spectroscopy studies, show that the near-surface region of nanowires can be transformed from weakly n-type to p-type with the increase of Mg doping.
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Affiliation(s)
- Q Wang
- Department of Electrical and Computer Engineering, McGill University, 3480 University Street, Montreal, QC H3A 0E9, Canada.
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Lee HL, Ho WY, Lam YL, Ng TP, Li KH, Shek T, Mak KL, Fong ST, So YC, Ngan RKC, Lau PPL, Chan ACL. Prognostic factors associated with clear cell sarcoma in 14 Chinese patients. J Orthop Surg (Hong Kong) 2014; 22:236-9. [PMID: 25163964 DOI: 10.1177/230949901402200226] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
PURPOSE. To identify prognostic factors associated with clear cell sarcomas in 14 Chinese patients. METHODS. Medical records of 7 men and 7 women (mean age, 36 years) with histologically confirmed clear cell sarcoma of tendons and aponeuroses were reviewed. Patient demographics, tumour characteristics, and treatment modalities were retrieved. Prognostic factors associated with favourable 5-year survival were determined. RESULTS. The most affected sites were the thigh (n=5) and the foot (n=4); the mean time from symptom onset to diagnosis was 9.5 months. The tumour stage at diagnosis was IIA in 8 patients, IIB in 2, and III in 4. The mean tumour size was 4.5 cm in diameter. One patient was lost to follow-up. For the remaining 13 patients, the mean time to disease-related mortality was 2.5 years. Nine patients had distant metastases; the most common sites were lungs and pleura (n=7), followed by distant lymph nodes (n=4), bone (n=2), pericardium (n=2), and brain (n=1). All patients underwent surgical excision. Three women and one man (mean age, 27 years) attained 5-year disease-free survival. All had stage IIA tumours at diagnosis. Their mean tumour size was 1.75 cm in diameter, which was significantly smaller than that of all patients (4.5 cm). Tumour size of ≤ 2.5 cm in diameter (p=0.004) and stage IIA tumour at diagnosis (p=0.04) were significant prognostic factors for 5-year survival. CONCLUSION. Tumour size of ≤ 2.5 cm and early stage tumour are associated with 5-year disease-free survival. Early detection is crucial for the prognosis of clear cell sarcomas.
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Affiliation(s)
- H L Lee
- Department of Orthopaedics and Traumatology, Queen Mary Hospital, Hong Kong
| | - W Y Ho
- Department of Orthopaedics and Traumatology, Queen Mary Hospital, Hong Kong
| | - Y L Lam
- Department of Orthopaedics and Traumatology, Queen Mary Hospital, Hong Kong
| | - T P Ng
- Department of Orthopaedics and Traumatology, Queen Mary Hospital, Hong Kong
| | - K H Li
- Department of Surgery, Queen Mary Hospital, Hong Kong
| | - T Shek
- Department of Pathology, Queen Mary Hospital, Hong Kong
| | - K L Mak
- Department of Orthopaedics and Traumatology, Queen Elizabeth Hospital, Hong Kong
| | - S T Fong
- Department of Orthopaedics and Traumatology, Queen Elizabeth Hospital, Hong Kong
| | - Y C So
- Department of Orthopaedics and Traumatology, Queen Elizabeth Hospital, Hong Kong
| | - R K C Ngan
- Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong
| | - P P L Lau
- Department of Pathology, Queen Elizabeth Hospital, Hong Kong
| | - A C L Chan
- Department of Pathology, Queen Elizabeth Hospital, Hong Kong
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Cho Y, Di Liberto V, Carlin D, Abe N, Li KH, Burlingame AL, Guan S, Michaelevski I, Cavalli V. Syntaxin13 expression is regulated by mammalian target of rapamycin (mTOR) in injured neurons to promote axon regeneration. J Biol Chem 2014; 289:15820-32. [PMID: 24737317 DOI: 10.1074/jbc.m113.536607] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Injured peripheral neurons successfully activate intrinsic signaling pathways to enable axon regeneration. We have previously shown that dorsal root ganglia (DRG) neurons activate the mammalian target of rapamycin (mTOR) pathway following injury and that this activity enhances their axon growth capacity. mTOR plays a critical role in protein synthesis, but the mTOR-dependent proteins enhancing the regenerative capacity of DRG neurons remain unknown. To identify proteins whose expression is regulated by injury in an mTOR-dependent manner, we analyzed the protein composition of DRGs from mice in which we genetically activated mTOR and from mice with or without a prior nerve injury. Quantitative label-free mass spectrometry analyses revealed that the injury effects were correlated with mTOR activation. We identified a member of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) family of proteins, syntaxin13, whose expression was increased by injury in an mTOR-dependent manner. Increased syntaxin13 levels in injured nerves resulted from local protein synthesis and not axonal transport. Finally, knockdown of syntaxin13 in cultured DRG neurons prevented axon growth and regeneration. Together, these data suggest that syntaxin13 translation is regulated by mTOR in injured neurons to promote axon regeneration.
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Affiliation(s)
- Yongcheol Cho
- From the Department of Anatomy and Neurobiology, Washington University in St Louis, School of Medicine, St. Louis, Missouri 63110
| | - Valentina Di Liberto
- From the Department of Anatomy and Neurobiology, Washington University in St Louis, School of Medicine, St. Louis, Missouri 63110
| | - Dan Carlin
- From the Department of Anatomy and Neurobiology, Washington University in St Louis, School of Medicine, St. Louis, Missouri 63110
| | - Namiko Abe
- From the Department of Anatomy and Neurobiology, Washington University in St Louis, School of Medicine, St. Louis, Missouri 63110
| | - Kathy H Li
- the Mass Spectrometry Facility, Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, California 94158-2517, and
| | - Alma L Burlingame
- the Mass Spectrometry Facility, Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, California 94158-2517, and
| | - Shenheng Guan
- the Mass Spectrometry Facility, Department of Pharmaceutical Chemistry, University of California at San Francisco, San Francisco, California 94158-2517, and
| | - Izhak Michaelevski
- the Department of Biochemistry and Molecular Biology, Tel Aviv University, Tel Aviv 69978, Israel
| | - Valeria Cavalli
- From the Department of Anatomy and Neurobiology, Washington University in St Louis, School of Medicine, St. Louis, Missouri 63110,
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46
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Yu Y, Guo LB, Hao ZQ, Li XY, Shen M, Zeng QD, Li KH, Zeng XY, Lu YF, Ren Z. Accuracy improvement on polymer identification using laser-induced breakdown spectroscopy with adjusting spectral weightings. Opt Express 2014; 22:3895-3901. [PMID: 24663709 DOI: 10.1364/oe.22.003895] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
A new approach to polymer identification by laser-induced breakdown spectroscopy (LIBS) with adjusting spectral weightings (ASW) was developed in this work aiming at improving the identification accuracy. This approach has been achieved through increasing the intensities of specific characteristic spectral lines which are important to polymer identification but difficult to be excited. Using the ASW method, the identification accuracies of all 11 polymers were increased to nearly 100%, while the accuracies of PE, PU, PP and PC were only 98%, 74%, 90% and 98%, respectively, without using the ASW method.
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47
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Li KH, Sun BH, Zhu Y, Long HT. Locked pubic symphysis into the obturator foramen: a rare case presentation and literature review. Orthop Traumatol Surg Res 2013; 99:106-10. [PMID: 23270720 DOI: 10.1016/j.otsr.2012.08.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [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: 04/05/2012] [Revised: 07/27/2012] [Accepted: 08/21/2012] [Indexed: 02/02/2023]
Abstract
Locked pubic symphysis is a rare form of pelvic injury. It occasionally occurs after a lateral compression injury of the pelvis. We described an overlapping pubic symphysis dislocation that was locked into the contralateral obturator foramen. To the best of our knowledge, there are about seventeen similar cases reported in the literature. The pubic symphysis was finally reduced by means of a superior pubic ramus osteotomy to unlock the incarcerated pubic body out of the contralateral obturator foramen. As the reduction was unstable, the pubic symphysis was fixed with a reconstruction plate. The patient recovered completely and returned to normal activities within 4months. At 1year's follow-up she reported no discomfort in the pubic symphysis region and was able to void urine normally.
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Affiliation(s)
- K H Li
- Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan, China
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48
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Abstract
An ordered hexagonal closed-packed nanopillar array is fabricated on GaN. A metal coating is then applied to encapsulate the pillars for promoting optical confinement within the cylindrical cavity. Room-temperature lasing at 373 nm is observed under pulsed excitation, at a lasing threshold of 0.42 MW/cm2. With pillar diameters of around 980 nm, the number of modes overlapping the emission spectrum is reduced, giving rise to single-mode whispering gallery stimulated emission. Finite-difference time-domain simulations are carried out for the prediction of resonant frequencies and electric field patterns corresponding to the resonant modes.
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Affiliation(s)
- K H Li
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong, China
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49
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Li T, Xu SL, Oses-Prieto JA, Putil S, Xu P, Wang RJ, Li KH, Maltby DA, An LH, Burlingame AL, Deng ZP, Wang ZY. Proteomics analysis reveals post-translational mechanisms for cold-induced metabolic changes in Arabidopsis. Mol Plant 2011; 4:361-74. [PMID: 21242321 PMCID: PMC3063518 DOI: 10.1093/mp/ssq078] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [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: 11/29/2010] [Accepted: 12/01/2010] [Indexed: 05/21/2023]
Abstract
Cold-induced changes of gene expression and metabolism are critical for plants to survive freezing. Largely by changing gene expression, exposure to a period of non-freezing low temperatures increases plant tolerance to freezing-a phenomenon known as cold acclimation. Cold also induces rapid metabolic changes, which provide instant protection before temperature drops below freezing point. The molecular mechanisms for such rapid metabolic responses to cold remain largely unknown. Here, we use two-dimensional difference gel electrophoresis (2-D DIGE) analysis of sub-cellular fractions of Arabidopsis thaliana proteome coupled with spot identification by tandem mass spectrometry to identify early cold-responsive proteins in Arabidopsis. These proteins include four enzymes involved in starch degradation, three HSP100 proteins, several proteins in the tricarboxylic acid cycle, and sucrose metabolism. Upon cold treatment, the Disproportionating Enzyme 2 (DPE2), a cytosolic transglucosidase metabolizing maltose to glucose, increased rapidly in the centrifugation pellet fraction and decreased in the soluble fraction. Consistent with cold-induced inactivation of DPE2 enzymatic activity, the dpe2 mutant showed increased freezing tolerance without affecting the C-repeat binding transcription factor (CBF) transcriptional pathway. These results support a model that cold-induced inactivation of DPE2 leads to rapid accumulation of maltose, which is a cold-induced compatible solute that protects cells from freezing damage. This study provides evidence for a key role of rapid post-translational regulation of carbohydrate metabolic enzymes in plant protection against sudden temperature drop.
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Affiliation(s)
- Tian Li
- Key Laboratory of Arid and Grassland Agroecology of Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Shou-Ling Xu
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143, USA
| | - Juan A. Oses-Prieto
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143, USA
| | - Sunita Putil
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Peng Xu
- Institute of Molecular and Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei 050016, China
| | - Rui-Ju Wang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Kathy H. Li
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143, USA
| | - David A. Maltby
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143, USA
| | - Liz-He An
- Key Laboratory of Arid and Grassland Agroecology of Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou 730000, China
| | - Alma L. Burlingame
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94143, USA
| | - Zhi-Ping Deng
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
- To whom correspondence should be addressed. E-mail of Dr. Zhi-Yong Wang: , email of Dr. Zhi-Ping Deng:
| | - Zhi-Yong Wang
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
- To whom correspondence should be addressed. E-mail of Dr. Zhi-Yong Wang: , email of Dr. Zhi-Ping Deng:
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50
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Wang D, Oses-Prieto JA, Li KH, Fernandes JF, Burlingame AL, Walbot V. The male sterile 8 mutation of maize disrupts the temporal progression of the transcriptome and results in the mis-regulation of metabolic functions. Plant J 2010; 63:939-51. [PMID: 20626649 PMCID: PMC2974755 DOI: 10.1111/j.1365-313x.2010.04294.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [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: 05/22/2023]
Abstract
Maize anther ontogeny is complex, with the expression of more than 30,000 genes over 4 days of cell proliferation, cell fate acquisition and the start of meiosis. Although many male-sterile mutants disrupt these key steps, few have been investigated in detail. The terminal phenotypes of Zea mays (maize) male sterile 8 (ms8) are small anthers exhibiting meiotic failure. Here, we document much earlier defects: ms8 epidermal cells are normal in number but fail to elongate, and there are fewer, larger tapetal cells that retain, rather than secrete, their contents. ms8 meiocytes separate early, have extra space between them, occupied by excess callose, and the meiotic dyads abort. Thousands of transcriptome changes occur in ms8, including ectopic activation of genes not expressed in fertile siblings, failure to express some genes, differential expression compared with fertile siblings and about 40% of the differentially expressed transcripts appear precociously. There is a high correlation between mRNA accumulation assessed by microarray hybridization and quantitative real-time reverse transcriptase polymerase chain reaction. Sixty-three differentially expressed proteins were identified after two-dimensional gel electrophoresis followed by liquid chromatography tandem mass spectroscopy, including those involved in metabolism, plasmodesmatal remodeling and cell division. The majority of these were not identified by differential RNA expression, demonstrating the importance of proteomics in defining developmental mutants.
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Affiliation(s)
- Dongxue Wang
- Department of Biology, 385 Serra Mall, Stanford University, Stanford, CA, 94305-5020
| | - Juan A. Oses-Prieto
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA,94143
| | - Kathy H. Li
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA,94143
| | - John F. Fernandes
- Department of Biology, 385 Serra Mall, Stanford University, Stanford, CA, 94305-5020
| | - Alma L. Burlingame
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA,94143
| | - Virginia Walbot
- Department of Biology, 385 Serra Mall, Stanford University, Stanford, CA, 94305-5020
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