1
|
Lukenge M, Ignell R, Hill SR. Adenosine triphosphate overrides the aversive effect of antifeedants and toxicants: a model alternative phagostimulant for sugar-based vector control tools. Parasit Vectors 2023; 16:416. [PMID: 37964326 PMCID: PMC10647091 DOI: 10.1186/s13071-023-06039-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 10/30/2023] [Indexed: 11/16/2023] Open
Abstract
BACKGROUND Sugar, when used as the phagostimulant in attractive toxic bait control tools, limits the efficacy and selectivity of this technology. Thus, more potent and selective phagostimulants than sugar are required to improve this technology. The potency of adenosine triphosphate (ATP) as an alternative model phagostimulant was assessed to determine its capacity to override the aversive effects of select antifeedants and toxicants. How ATP and sucrose modulate the rate of toxicity in the yellow fever mosquito Aedes aegypti was also examined. METHODS A no-choice feeding assay was used to investigate the phagostimulatory ability of ATP to override the aversive effects of structurally divergent antifeedant and toxicant compounds, and to modulate the rate of toxicity over 24 h. Binary combinations of antifeedant and toxicant compounds, at various concentrations, were similarly assessed for enhanced lethal potency. In comparison, no-choice open access and cotton wick feeding assays were used to determine the phagostimulatory role of sucrose in the ingestion of boric acid-laced diets. Dissections of the guts were performed to determine the diet destination as dependant on the phagostimulant. RESULTS ATP is a potent phagostimulant that dose dependently overrides aversion to antifeedant and toxicant tastants. Feeding on antifeedant- or toxicant-laced diets that was induced by ATP selectively resulted in rapid knockdown (nicotine, lobeline and caffeine) or death (boric acid and propylene glycol), with a combination of the two lethal compounds inducing a synergistic effect at lower concentrations. ATP- and sucrose-induced feeding predominantly directed the antifeedant- or toxicant-laced meals to the midgut and the crop, respectively. CONCLUSIONS ATP is an efficacious alternative model phagostimulant to sucrose that overrides the aversive effects of antifeedants and toxicants, resulting in rapid toxic effects. Furthermore, this study demonstrates that variation in the rate of toxicity between ATP- and sugar-induced feeding is at least partly regulated by the differential feeding response, volume imbibed and the destination of the meals. Additional research is needed to identify structurally related, stable analogues of ATP due to the ephemeral nature of this molecule. For future applications, the workflow presented in this study may be used to evaluate such analogues for their suitability for use in attractive bait stations designed to target a broad range of haematophagous arthropods and prevent off-target species' feeding.
Collapse
Affiliation(s)
- Matthew Lukenge
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Rickard Ignell
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden
| | - Sharon Rose Hill
- Disease Vector Group, Unit of Chemical Ecology, Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden.
| |
Collapse
|
2
|
Saldarriaga CA, Alatout MH, Khurram OU, Gransee HM, Sieck GC, Mantilla CB. Chloroquine impairs maximal transdiaphragmatic pressure generation in old mice. J Appl Physiol (1985) 2023; 135:1126-1134. [PMID: 37823202 PMCID: PMC10979802 DOI: 10.1152/japplphysiol.00365.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 09/19/2023] [Accepted: 10/07/2023] [Indexed: 10/13/2023] Open
Abstract
Aging results in increased neuromuscular transmission failure and denervation of the diaphragm muscle, as well as decreased force generation across a range of motor behaviors. Increased risk for respiratory complications in old age is a major health problem. Aging impairs autophagy, a tightly regulated multistep process responsible for clearing misfolded or aggregated proteins and damaged organelles. In motor neurons, aging-related autophagy impairment may contribute to deficits in neurotransmission, subsequent muscle atrophy, and loss of muscle force. Chloroquine is commonly used to inhibit autophagy. We hypothesized that chloroquine decreases transdiaphragmatic pressure (Pdi) in mice. Old mice (16-28 mo old; n = 26) were randomly allocated to receive intraperitoneal chloroquine (50 mg/kg) or vehicle 4 h before measuring Pdi during eupnea, hypoxia (10% O2)-hypercapnia (5% CO2) exposure, spontaneous deep breaths ("sighs"), and maximal activation elicited by bilateral phrenic nerve stimulation (Pdimax). Pdi amplitude and ventilatory parameters across experimental groups and behaviors were evaluated using a mixed linear model. There were no differences in Pdi amplitude across treatments during eupnea (∼8 cm H2O), hypoxia-hypercapnia (∼10 cm H2O), or sigh (∼36 cm H2O), consistent with prior studies documenting a lack of aging effects on ventilatory behaviors. In vehicle and chloroquine-treated mice, average Pdimax was 61 and 46 cm H2O, respectively. Chloroquine decreased Pdimax by 24% compared to vehicle (P < 0.05). There were no sex or age effects on Pdi in older mice. The observed decrease in Pdimax suggests aging-related susceptibility to impairments in autophagy, consistent with the effects of chloroquine on this important homeostatic process.NEW & NOTEWORTHY Recent findings suggest that autophagy plays a role in the development of aging-related neuromuscular dysfunction; however, the contribution of autophagy impairment to the maintenance of diaphragm force generation in old age is unknown. This study shows that in old mice, chloroquine administration decreases maximal transdiaphragmatic pressure generation. These chloroquine effects suggest a susceptibility to impairments in autophagy in old age.
Collapse
Affiliation(s)
- Carlos A Saldarriaga
- Department of Anesthesiology and Perioperative Medicine, College of Medicine and Science, Mayo Clinic, Rochester, Minnesota, United States
| | - Mayar H Alatout
- Department of Anesthesiology and Perioperative Medicine, College of Medicine and Science, Mayo Clinic, Rochester, Minnesota, United States
| | - Obaid U Khurram
- Department of Physiology and Biomedical Engineering, College of Medicine and Science, Mayo Clinic, Rochester, Minnesota, United States
| | - Heather M Gransee
- Department of Anesthesiology and Perioperative Medicine, College of Medicine and Science, Mayo Clinic, Rochester, Minnesota, United States
| | - Gary C Sieck
- Department of Anesthesiology and Perioperative Medicine, College of Medicine and Science, Mayo Clinic, Rochester, Minnesota, United States
- Department of Physiology and Biomedical Engineering, College of Medicine and Science, Mayo Clinic, Rochester, Minnesota, United States
| | - Carlos B Mantilla
- Department of Anesthesiology and Perioperative Medicine, College of Medicine and Science, Mayo Clinic, Rochester, Minnesota, United States
- Department of Physiology and Biomedical Engineering, College of Medicine and Science, Mayo Clinic, Rochester, Minnesota, United States
| |
Collapse
|
3
|
Patel RN, Clare RH, Ledsgaard L, Nys M, Kool J, Laustsen AH, Ulens C, Casewell NR. An in vitro assay to investigate venom neurotoxin activity on muscle-type nicotinic acetylcholine receptor activation and for the discovery of toxin-inhibitory molecules. Biochem Pharmacol 2023; 216:115758. [PMID: 37604290 PMCID: PMC10570928 DOI: 10.1016/j.bcp.2023.115758] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 08/14/2023] [Accepted: 08/17/2023] [Indexed: 08/23/2023]
Abstract
Snakebite envenoming is a neglected tropical disease that causes over 100,000 deaths annually. Envenomings result in variable pathologies, but systemic neurotoxicity is among the most serious and is currently only treated with difficult to access and variably efficacious commercial antivenoms. Venom-induced neurotoxicity is often caused by α-neurotoxins antagonising the muscle-type nicotinic acetylcholine receptor (nAChR), a ligand-gated ion channel. Discovery of therapeutics targeting α-neurotoxins is hampered by relying on binding assays that do not reveal restoration of receptor activity or more costly and/or lower throughput electrophysiology-based approaches. Here, we report the validation of a screening assay for nAChR activation using immortalised TE671 cells expressing the γ-subunit containing muscle-type nAChR and a fluorescent dye that reports changes in cell membrane potential. Assay validation using traditional nAChR agonists and antagonists, which either activate or block ion fluxes, was consistent with previous studies. We then characterised antagonism of the nAChR by a variety of elapid snake venoms that cause muscle paralysis in snakebite victims, before defining the toxin-inhibiting activities of commercial antivenoms, and new types of snakebite therapeutic candidates, namely monoclonal antibodies, decoy receptors, and small molecules. Our findings show robust evidence of assay uniformity across 96-well plates and highlight the amenability of this approach for the future discovery of new snakebite therapeutics via screening campaigns. The described assay therefore represents a useful first-step approach for identifying α-neurotoxins and their inhibitors in the context of snakebite envenoming, and it should provide wider value for studying modulators of nAChR activity from other sources.
Collapse
Affiliation(s)
- Rohit N Patel
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, L3 5QA, UK; Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, UK
| | - Rachel H Clare
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, L3 5QA, UK; Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, UK
| | - Line Ledsgaard
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Mieke Nys
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, Belgium
| | - Jeroen Kool
- AIMMS Division of BioAnalytical Chemistry, Vrije Universiteit Amsterdam, Netherlands
| | - Andreas H Laustsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Chris Ulens
- Laboratory of Structural Neurobiology, Department of Cellular and Molecular Medicine, Faculty of Medicine, KU Leuven, Belgium
| | - Nicholas R Casewell
- Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, L3 5QA, UK; Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, L3 5QA, UK.
| |
Collapse
|
4
|
Amyotrophic Lateral Sclerosis as an Adverse Drug Reaction: A Disproportionality Analysis of the Food and Drug Administration Adverse Event Reporting System. Drug Saf 2022; 45:663-673. [PMID: 35610460 DOI: 10.1007/s40264-022-01184-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/26/2022] [Indexed: 11/03/2022]
Abstract
INTRODUCTION Amyotrophic lateral sclerosis is a fatal progressive disease with a still unclear multi-factorial etiology. This study focused on the potential relationship between drug exposure and the development of amyotrophic lateral sclerosis by performing a detailed analysis of events reported in the FDA Adverse Event Reporting System database. METHODS The FDA Adverse Event Reporting System quarterly data (January 2004-June 2020) were downloaded and deduplicated. The reporting odds ratios and their 95% confidence intervals were calculated as a disproportionality measure. The robustness of the disproportion was assessed accounting for major confounders (i.e., using a broader query, restricting to suspect drugs, and excluding reports with amyotrophic lateral sclerosis as an indication). Disproportionality signals were prioritized based on their consistency across analyses (reporting odds ratio stability). RESULTS We retained 1188 amyotrophic lateral sclerosis cases. Sixty-two drugs showed significant disproportionality for amyotrophic lateral sclerosis onset in at least one analysis, and 31 had consistent reporting odds ratio stability, including tumor necrosis factor-alpha inhibitors and statins. Disproportionality signals from ustekinumab, an immunomodulator against interleukins 12-23 used in autoimmune diseases, and the anti-IgE omalizumab were consistent among analyses and unexpected. CONCLUSIONS For each drug emerging as possibly associated with amyotrophic lateral sclerosis onset, biological plausibility, underlying disease, and reverse causality could be argued. Our findings strengthened the plausibility of a precipitating role of drugs primarily through immunomodulation (e.g., tumor necrosis factor-alpha, ustekinumab, and omalizumab), but also by impacting metabolism and the musculoskeletal integrity (e.g., statins and bisphosphonates). Complement and NF-kB dysregulation could represent interesting topics for planning translational mechanistic studies on amyotrophic lateral sclerosis as an adverse drug effect.
Collapse
|
5
|
Županić S, Lazibat I, Rubinić Majdak M, Jeličić M. TREATMENT OF MYASTHENIA GRAVIS PATIENTS WITH COVID-19: REVIEW OF THE LITERATURE. Acta Clin Croat 2022; 60:496-509. [PMID: 35282492 PMCID: PMC8907958 DOI: 10.20471/acc.2021.60.03.21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 03/22/2021] [Indexed: 11/24/2022] Open
Abstract
Coronavirus disease 2019 (COVID-19), caused by the late 2019 outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causes a respiratory disease which could put myasthenia gravis (MG) patients at a greater risk of developing severe disease course, since infections and some drugs are a well-recognized trigger of symptom exacerbation in MG patients. Out of ten most commonly used past and present drugs used in COVID-19 treatment, two (quinolone derivatives and azithromycin) are known to worsen MG symptoms, whereas another two (tocilizumab and eculizumab) might have positive effect on MG symptoms. Colchicine, remdesivir, lopinavir, ritonavir and favipiravir seem to be safe to use, while data are insufficient for bamlanivimab, although it is also probably safe to use. Considering MG treatment options in patients infected with SARS-CoV-2, acetylcholine esterase inhibitors are generally safe to use with some preliminary studies even demonstrating therapeutic properties in regard to COVID-19. Corticosteroids are in general safe to use, even recommended in specific circumstances, whereas other immunosuppressive medications (mycophenolate mofetil, azathioprine, cyclosporine, methotrexate) are probably safe to use. The only exception is rituximab since the resulting B cell depletion can lead to more severe COVID-19 disease. Concerning plasmapheresis and intravenous immunoglobulins, both can be used in COVID-19 while taking into consideration thromboembolic properties of the former and hemodynamic disturbances of the latter. As current data suggest, all known COVID-19 vaccines are safe to use in MG patients.
Collapse
|
6
|
Harris N, Benedict J, Dickie DA, Pagola S. Mechanochemical synthesis insights and solid-state characterization of quininium aspirinate, a glass-forming drug-drug salt. Acta Crystallogr C Struct Chem 2021; 77:566-576. [PMID: 34482301 PMCID: PMC8418670 DOI: 10.1107/s2053229621008275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 08/11/2021] [Indexed: 11/10/2022] Open
Abstract
Quinine (an antimalarial) and aspirin (a nonsteroidal anti-inflammatory drug) were combined into a new drug-drug salt, quininium aspirinate, C20H25N2O2+·C9H7O4-, by liquid-assisted grinding using stoichiometric amounts of the reactants in a 1:1 molar ratio, and water, EtOH, toluene, or heptane as additives. A tetrahydrofuran (THF) solution of the mechanochemical product prepared using EtOH as additive led to a single crystal of the same material obtained by mechanochemistry, which was used for crystal structure determination at 100 K. Powder X-ray diffraction ruled out crystallographic phase transitions in the 100-295 K interval. Neat mechanical treatment (in a mortar and pestle, or in a ball mill at 20 or 30 Hz milling frequencies) gave rise to an amorphous phase, as shown by powder X-ray diffraction; however, FT-IR spectroscopy unambiguously indicates that a mechanochemical reaction has occurred. Neat milling the reactants at 10 and 15 Hz led to incomplete reactions. Thermogravimetry and differential scanning calorimetry indicate that the amorphous and crystalline mechanochemical products form glasses/supercooled liquids before melting, and do not recrystallize upon cooling. However, the amorphous material obtained by neat grinding crystallizes upon storage into the salt reported. The mechanochemical synthesis, crystal structure analysis, Hirshfeld surfaces, powder X-ray diffraction, thermogravimetry, differential scanning calorimetry, FT-IR spectroscopy, and aqueous solubility of quininium aspirinate are herein reported.
Collapse
Affiliation(s)
- Nehemiah Harris
- Department of Chemistry and Biochemistry, Old Dominion University, 4402 Elkhorn Ave., Norfolk, VA 23529, USA
| | - Jubilee Benedict
- Department of Chemistry and Biochemistry, Old Dominion University, 4402 Elkhorn Ave., Norfolk, VA 23529, USA
| | - Diane A. Dickie
- Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA
| | - Silvina Pagola
- Department of Chemistry and Biochemistry, Old Dominion University, 4402 Elkhorn Ave., Norfolk, VA 23529, USA
| |
Collapse
|
7
|
Crosstalk of Multi-Omics Platforms with Plants of Therapeutic Importance. Cells 2021; 10:cells10061296. [PMID: 34071113 PMCID: PMC8224614 DOI: 10.3390/cells10061296] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/25/2021] [Accepted: 05/10/2021] [Indexed: 02/06/2023] Open
Abstract
From time immemorial, humans have exploited plants as a source of food and medicines. The World Health Organization (WHO) has recorded 21,000 plants with medicinal value out of 300,000 species available worldwide. The promising modern "multi-omics" platforms and tools have been proven as functional platforms able to endow us with comprehensive knowledge of the proteome, genome, transcriptome, and metabolome of medicinal plant systems so as to reveal the novel connected genetic (gene) pathways, proteins, regulator sequences and secondary metabolite (molecule) biosynthetic pathways of various drug and protein molecules from a variety of plants with therapeutic significance. This review paper endeavors to abridge the contemporary advancements in research areas of multi-omics and the information involved in decoding its prospective relevance to the utilization of plants with medicinal value in the present global scenario. The crosstalk of medicinal plants with genomics, transcriptomics, proteomics, and metabolomics approaches will be discussed.
Collapse
|
8
|
Kudryavtsev D, Isaeva A, Barkova D, Spirova E, Mukhutdinova R, Kasheverov I, Tsetlin V. Point Mutations of Nicotinic Receptor α1 Subunit Reveal New Molecular Features of G153S Slow-Channel Myasthenia. Molecules 2021; 26:molecules26051278. [PMID: 33652901 PMCID: PMC7956382 DOI: 10.3390/molecules26051278] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/18/2021] [Accepted: 02/23/2021] [Indexed: 11/16/2022] Open
Abstract
Slow-channel congenital myasthenic syndromes (SCCMSs) are rare genetic diseases caused by mutations in muscle nicotinic acetylcholine receptor (nAChR) subunits. Most of the known SCCMS-associated mutations localize at the transmembrane region near the ion pore. Only two SCCMS point mutations are at the extracellular domains near the acetylcholine binding site, α1(G153S) being one of them. In this work, a combination of molecular dynamics, targeted mutagenesis, fluorescent Ca2+ imaging and patch-clamp electrophysiology has been applied to G153S mutant muscle nAChR to investigate the role of hydrogen bonds formed by Ser 153 with C-loop residues near the acetylcholine-binding site. Introduction of L199T mutation to the C-loop in the vicinity of Ser 153 changed hydrogen bonds distribution, decreased acetylcholine potency (EC50 2607 vs. 146 nM) of the double mutant and decay kinetics of acetylcholine-evoked cytoplasmic Ca2+ rise (τ 14.2 ± 0.3 vs. 34.0 ± 0.4 s). These results shed light on molecular mechanisms of nAChR activation-desensitization and on the involvement of such mechanisms in channelopathy genesis.
Collapse
Affiliation(s)
- Denis Kudryavtsev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (A.I.); (E.S.); (R.M.); (I.K.); (V.T.)
- Correspondence:
| | - Anastasia Isaeva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (A.I.); (E.S.); (R.M.); (I.K.); (V.T.)
- Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia
| | - Daria Barkova
- Biological Department, Lomonosov Moscow State University, 119991 Moscow, Russia;
| | - Ekaterina Spirova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (A.I.); (E.S.); (R.M.); (I.K.); (V.T.)
| | - Renata Mukhutdinova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (A.I.); (E.S.); (R.M.); (I.K.); (V.T.)
- Biological Department, Lomonosov Moscow State University, 119991 Moscow, Russia;
| | - Igor Kasheverov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (A.I.); (E.S.); (R.M.); (I.K.); (V.T.)
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Trubetskaya str. 8, bld. 2, 119991 Moscow, Russia
| | - Victor Tsetlin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya 16/10, 117997 Moscow, Russia; (A.I.); (E.S.); (R.M.); (I.K.); (V.T.)
- Institute of Engineering Physics for Biomedicine, MePhi, 115409 Moscow, Russia
| |
Collapse
|
9
|
Qian X, He Z, Wang Y, Chen B, Hetrick A, Dai C, Chi F, Li H, Ren D. Hair cell uptake of gentamicin in the developing mouse utricle. J Cell Physiol 2020; 236:5235-5252. [PMID: 33368220 DOI: 10.1002/jcp.30228] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 11/27/2020] [Accepted: 12/08/2020] [Indexed: 12/27/2022]
Abstract
Intratympanic injection of gentamicin has proven to be an effective therapy for intractable vestibular dysfunction. However, most studies to date have focused on the cochlea, so little is known about the distribution and uptake of gentamicin by the counterpart of the auditory system, specifically vestibular hair cells (HCs). Here, with a combination of in vivo and in vitro approaches, we used a gentamicin-Texas Red (GTTR) conjugate to investigate the mechanisms of gentamicin vestibulotoxicity in the developing mammalian utricular HCs. In vivo, GTTR fluorescence was concentrated in the apical cytoplasm and the cellular membrane of neonatal utricular HCs, but scarce in the nucleus of HCs and supporting cells. Quantitative analysis showed the GTTR uptake by striolar HCs was significantly higher than that in the extrastriola. In addition, the GTTR fluorescence intensity in the striola was increased gradually from 1 to 8 days, peaking at 8-9 days postnatally. In vitro, utricle explants were incubated with GTTR and candidate uptake conduits, including mechanotransduction (MET) channels and endocytosis in the HC, were inhibited separately. GTTR uptake by HCs could be inhibited by quinine, a blocker of MET channels, under both normal and stressed conditions. Meanwhile, endocytic inhibition only reduced GTTR uptake in the CoCl2 hypoxia model. In sum, the maturation of MET channels mediated uptake of GTTR into vestibular HCs. Under stressed conditions, MET channels play a pronounced role, manifested by channel-dependent stress enhanced GTTR permeation, while endocytosis participates in GTTR entry in a more selective manner.
Collapse
Affiliation(s)
- Xiaoqing Qian
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| | - Ziyu He
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| | - Yanmei Wang
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| | - Binjun Chen
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| | - Alisa Hetrick
- Research Service, VA Loma Linda Healthcare System, Loma Linda, California, USA
| | - Chunfu Dai
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| | - Fanglu Chi
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| | - Hongzhe Li
- Research Service, VA Loma Linda Healthcare System, Loma Linda, California, USA.,Department of Otolaryngology-Head and Neck Surgery, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Dongdong Ren
- ENT Institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China.,NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| |
Collapse
|
10
|
Moshirfar M, Somani SN, Shmunes KM, Ronquillo YC. Will Tonic Water Stop My Eyelid Twitching? Clin Ophthalmol 2020; 14:689-691. [PMID: 32184555 PMCID: PMC7061523 DOI: 10.2147/opth.s235895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 01/21/2020] [Indexed: 11/25/2022] Open
Abstract
Eyelid myokymia, commonly referred to as “eyelid twitching”, is a common, benign condition that resolves in most individuals within hours to days; however, chronic cases can persist for several weeks to months, prompting the search for home remedies that may reduce the frequency or duration of symptoms. In this article, we discuss the proposed pathophysiologic mechanism and safety concerns surrounding tonic water as a treatment for eyelid myokymia.
Collapse
Affiliation(s)
- Majid Moshirfar
- HDR Research Center, Hoopes Vision, Draper, UT, USA.,John A. Moran Eye Center, University of Utah School of Medicine, Salt Lake City, UT, USA.,Utah Lions Eye Bank, Murray, UT, USA
| | - Shaan N Somani
- Northwestern Feinberg School of Medicine, Chicago, IL 60611, USA
| | | | | |
Collapse
|
11
|
Heterogeneous Network Model to Identify Potential Associations Between Plasmodium vivax and Human Proteins. Int J Mol Sci 2020; 21:ijms21041310. [PMID: 32075230 PMCID: PMC7072978 DOI: 10.3390/ijms21041310] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Revised: 01/29/2020] [Accepted: 02/12/2020] [Indexed: 02/06/2023] Open
Abstract
Integration of multiple sources and data levels provides a great insight into the complex associations between human and malaria systems. In this study, a meta-analysis framework was developed based on a heterogeneous network model for integrating human-malaria protein similarities, a human protein interaction network, and a Plasmodium vivax protein interaction network. An iterative network propagation was performed on the heterogeneous network until we obtained stabilized weights. The association scores were calculated for qualifying a novel potential human-malaria protein association. This method provided a better performance compared to random experiments. After that, the stabilized network was clustered into association modules. The potential association candidates were then thoroughly analyzed by statistical enrichment analysis with protein complexes and known drug targets. The most promising target proteins were the succinate dehydrogenase protein complex in the human citrate (TCA) cycle pathway and the nicotinic acetylcholine receptor in the human central nervous system. Promising associations and potential drug targets were also provided for further studies and designs in therapeutic approaches for malaria at a systematic level. In conclusion, this method is efficient to identify new human-malaria protein associations and can be generalized to infer other types of association studies to further advance biomedical science.
Collapse
|
12
|
Lakes JE, Richards CI, Flythe MD. Inhibition of Bacteroidetes and Firmicutes by select phytochemicals. Anaerobe 2019; 61:102145. [PMID: 31918362 DOI: 10.1016/j.anaerobe.2019.102145] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 12/11/2019] [Accepted: 12/23/2019] [Indexed: 01/26/2023]
Abstract
Current research indicates that changes in gut microbiota can impact the host, but it is not always clear how dietary and environmental factors alter gut microbiota. One potential factor is antimicrobial activity of compounds ingested by the host. The goal of this study was to determine the antimicrobial activity of common plant secondary metabolites against pure cultures of paired, structurally and phylogenetically distinct gastrointestinal bacteria of human or bovine origin: Prevotella bryantii B14, Bacteroides fragilis 25285, Acetoanaerobium (Clostridium) sticklandii SR and Clostridioides difficile 9689. When growth media were amended with individual phytochemicals (the alkaloids: berberine, capsaicin, nicotine, piperine and quinine and the phenolic: curcumin), growth of each species was inhibited to varying degrees at the three greatest concentrations tested (0.10-10.00 mg mL-1). The viable cell numbers of all the cultures were reduced, ≥4-logs, by berberine at concentrations ≥1.00 mg mL-1. Quinine performed similarly to berberine for B14, 25285, and SR at the same concentrations. The other phytochemicals were inhibitory, but not as much as quinine or berberine. Nicotine had activity against all four species (≥2-log reduction in viable cell number at 10.00 mg mL-1), but had stronger activity against the Gram-positive bacteria, SR and 9689, (≥4-log reductions at 10.00 mg mL-1). In conclusion, the phytochemicals had varying spectra of antimicrobial activity. These results are consistent with the hypothesis that ingested phytochemicals have the ability to differentially impact gut microbiota through antimicrobial activity.
Collapse
Affiliation(s)
- Jourdan E Lakes
- Department of Chemistry, College of Arts & Sciences, University of Kentucky, Lexington, KY, USA
| | - Christopher I Richards
- Department of Chemistry, College of Arts & Sciences, University of Kentucky, Lexington, KY, USA
| | - Michael D Flythe
- USDA Agricultural Research Service Forage-Animal Production Research Unit, Lexington, KY, USA; Department of Animal and Food Sciences, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, USA.
| |
Collapse
|