1
|
Verardo C, Mele LJ, Selmi L, Palestri P. Finite-element modeling of neuromodulation via controlled delivery of potassium ions using conductive polymer-coated microelectrodes. J Neural Eng 2024; 21:026002. [PMID: 38306702 DOI: 10.1088/1741-2552/ad2581] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 02/02/2024] [Indexed: 02/04/2024]
Abstract
Objective. The controlled delivery of potassium is an interesting neuromodulation modality, being potassium ions involved in shaping neuron excitability, synaptic transmission, network synchronization, and playing a key role in pathological conditions like epilepsy and spreading depression. Despite many successful examples of pre-clinical devices able to influence the extracellular potassium concentration, computational frameworks capturing the corresponding impact on neuronal activity are still missing.Approach. We present a finite-element model describing a PEDOT:PSS-coated microelectrode (herein, simplyionic actuator) able to release potassium and thus modulate the activity of a cortical neuron in anin-vitro-like setting. The dynamics of ions in the ionic actuator, the neural membrane, and the cellular fluids are solved self-consistently.Main results. We showcase the capability of the model to describe on a physical basis the modulation of the intrinsic excitability of the cell and of the synaptic transmission following the electro-ionic stimulation produced by the actuator. We consider three case studies for the ionic actuator with different levels of selectivity to potassium: ideal selectivity, no selectivity, and selectivity achieved by embedding ionophores in the polymer.Significance. This work is the first step toward a comprehensive computational framework aimed to investigate novel neuromodulation devices targeting specific ionic species, as well as to optimize their design and performance, in terms of the induced modulation of neural activity.
Collapse
Affiliation(s)
- Claudio Verardo
- Polytechnic Department of Engineering and Architecture, Università degli Studi di Udine, Udine, Italy
- BioRobotics Institute and Department of Excellence in Robotics and AI, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Leandro Julian Mele
- Polytechnic Department of Engineering and Architecture, Università degli Studi di Udine, Udine, Italy
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, United States of America
| | - Luca Selmi
- Department of Engineering "Enzo Ferrari", Università degli Studi di Modena e Reggio Emilia, Modena, Italy
| | - Pierpaolo Palestri
- Polytechnic Department of Engineering and Architecture, Università degli Studi di Udine, Udine, Italy
- Department of Engineering "Enzo Ferrari", Università degli Studi di Modena e Reggio Emilia, Modena, Italy
| |
Collapse
|
2
|
Carresi C, Marabelli R, Roncada P, Britti D. Is the Use of Monensin Another Trojan Horse for the Spread of Antimicrobial Resistance? Antibiotics (Basel) 2024; 13:129. [PMID: 38391515 PMCID: PMC10886233 DOI: 10.3390/antibiotics13020129] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 01/19/2024] [Accepted: 01/26/2024] [Indexed: 02/24/2024] Open
Abstract
Antimicrobial resistance (AMR) is a complex and somewhat unpredictable phenomenon. Historically, the utilization of avoparcin in intensive farming during the latter part of the previous century led to the development of resistance to vancomycin, a crucial antibiotic in human medicine with life-saving properties. Currently, in the European Union, there is a growing reliance on the ionophore antibiotic monensin (MON), which acts both as a coccidiostat in poultry farming and as a preventative measure against ketosis in lactating cows. Although many researchers claim that MON does not induce cross-resistance to antibiotics of clinical relevance in human medicine, some conflicting reports exist. The numerous applications of MON in livestock farming and the consequent dissemination of the compound and its metabolites in the environment require further investigation to definitively ascertain whether MON represents a potential vector for the propagation of AMR. It is imperative to emphasize that antibiotics cannot substitute sound animal husbandry practices or tailored dietary regimens in line with the different production cycles of livestock. Consequently, a rigorous evaluation is indispensable to assess whether the economic benefits associated with MON usage justify its employment, also considering its local and global environmental ramifications and the potential risk of instigating AMR with increased costs for its control.
Collapse
Affiliation(s)
- Cristina Carresi
- Veterinary Pharmacology Laboratory, Department of Health Sciences, Interregional Research Center for Food Safety and Health IRC-FSH, University "Magna Graecia" of Catanzaro, 88100 Catanzaro, Italy
| | | | - Paola Roncada
- Department of Health Sciences, University "Magna Graecia" of Catanzaro, 88100 Catanzaro, Italy
| | - Domenico Britti
- Department of Health Sciences, University "Magna Graecia" of Catanzaro, 88100 Catanzaro, Italy
- Interdepartmental Center Veterinary Service for Human and Animal Health, University "Magna Graecia" of Catanzaro, CISVetSUA, 88100 Catanzaro, Italy
| |
Collapse
|
3
|
Sarmikasoglou E, Johnson ML, Vinyard JR, Sumadong P, Lobo RR, Arce-Cordero JA, Bahman A, Ravelo A, Halima S, Salas-Solis GK, Hikita C, Watanabe T, Faciola AP. Effects of cashew nutshell extract and monensin on microbial fermentation in a dual-flow continuous culture. J Dairy Sci 2023; 106:8746-8757. [PMID: 37678783 DOI: 10.3168/jds.2023-23597] [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] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 07/05/2023] [Indexed: 09/09/2023]
Abstract
The objective of this study was to compare cashew nutshell extract (CNSE) to monensin and evaluate changes in in vitro mixed ruminal microorganism fermentation, nutrient digestibility, and microbial nitrogen outflow. Treatments were randomly assigned to 8 fermenters in a replicated 4 × 4 Latin square design with 4 experimental periods of 10 d (7 d for diet adaptation and 3 d for sample collection). Basal diets contained 43.5:56.5 forage: concentrate ratio and each fermenter was fed 106 g of DM/d divided equally between 2 feeding times. Treatments were control (CON, basal diet without additives), 2.5 μM monensin (MON), 0.1 mg CNSE granule/g DM (CNSE100), and 0.2 mg CNSE granule/g DM (CNSE200). On d 8 to10, samples were collected for pH, lactate, NH3-N, volatile fatty acids (VFA), mixed protozoa counts, organic matter (OM), and neutral detergent fiber (NDF) digestibility. Data were analyzed with the GLIMMIX procedure of SAS. Orthogonal contrasts were used to test the effects of (1) ADD (CON vs. MON, CNSE100, and CNSE200); (2) MCN (MON vs. CNSE100 and CNSE200); and (3) DOSE (CNSE100 vs. CNSE200). We observed that butyrate concentration in all treatments was lower compared with CON and the concentration for MON was lower compared with CNSE treatments. Protozoal population in all treatments was lower compared with CON. No effects were observed for pH, lactate, NH3-N, total VFA, OM, or N utilization. Within the 24-h pool, protozoal generation time, tended to be lower, while NDF digestibility tended to be greater in response to all additives. Furthermore, the microbial N flow, and the efficiency of N use tended to be lower for the monensin treatment compared with CNSE treatments. Overall, our results showed that both monensin and CNSE decreased butyrate synthesis and protozoal populations, while not affecting OM digestibility and tended to increase NDF digestibility; however, such effects are greater with monensin than CNSE nutshell.
Collapse
Affiliation(s)
- E Sarmikasoglou
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611
| | - M L Johnson
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611
| | - J R Vinyard
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611
| | - P Sumadong
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611; Department of Animal Science, Khon Kaen University, Khon Kaen 40002, Thailand
| | - R R Lobo
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611
| | - J A Arce-Cordero
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611; Escuela de Zootecnia, Universidad de Costa Rica, San Jose, 11501-2060, Costa Rica
| | - A Bahman
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611
| | - A Ravelo
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611
| | - S Halima
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611
| | - G K Salas-Solis
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611
| | - C Hikita
- SDS Biotech K.K., Tokyo, Japan 101-0022
| | | | - A P Faciola
- Department of Animal Sciences, University of Florida, Gainesville, FL 32611.
| |
Collapse
|
4
|
Kar S, Madhavan N. An Amphiphilic Peptide Carrier for HCl Transport. Chemistry 2023:e202301020. [PMID: 37218621 DOI: 10.1002/chem.202301020] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/20/2023] [Accepted: 05/22/2023] [Indexed: 05/24/2023]
Abstract
Single molecules that co-transport cations as well as anions across lipid membranes are few despite their high biological utility. The elegant yet simple lipidomimetic peptide design herein enables efficient HCl transport without the use of any external additives for proton transport. The carboxylic acids in the dipeptide scaffold provide a handle to append two long hydrophobic tails and also provides a polar hydrophilic carboxylate group. The peptide central unit also provides NH sites for anion-binding. Protonation of the carboxylate group coupled with the weak halide binding of the terminal NH group results in HCl transport with transport rates of H+ > Cl‾. The lipid-like structure also facilitates seamless membrane integration and flipping of the molecule. The biocompatibility, design simplicity and potential pH regulation of these molecules open up several avenues for their therapeutic use.
Collapse
Affiliation(s)
- Sabnam Kar
- Indian Institute of Technology Bombay, Chemistry, INDIA
| | - Nandita Madhavan
- Indian Institute of Technology Bombay, Chemistry, Department of Chemistry, IIT Bombay, Powai, 400076, Mumbai, INDIA
| |
Collapse
|
5
|
Ekinci İB, Chłodowska A, Olejnik M. Ionophore Toxicity in Animals: A Review of Clinical and Molecular Aspects. Int J Mol Sci 2023; 24:1696. [PMID: 36675211 DOI: 10.3390/ijms24021696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/09/2023] [Accepted: 01/12/2023] [Indexed: 01/18/2023] Open
Abstract
For many years, ionophores have been used to control coccidiosis in poultry. However, misuse of ionophores can cause toxicity with significant clinical symptoms. The most critical factors influencing ionophores' toxicity are administration dose, species, and animal age. Although clinical signs of ionophore intoxication are well studied, the toxicity mechanisms of the ionophores at the molecular level still are not fully elucidated. This review summarizes the studies focused on polyether ionophores toxicity mechanisms in animals at the clinical and molecular levels. Studies show that ionophore toxicity mainly affects myocardial and skeletal muscle cells. The molecular mechanism of the toxication could be explained by the inhibition of oxidative phosphorylation via dysregulation of ion concentration. Tiamulin-ionophore interaction and the synergetic effect of tiamulin in ionophore biotransformation are discussed. Furthermore, in recent years ionophores were candidates for reprofiling as antibacterial and anti-cancer drugs. Identifying ionophores' toxicity mechanisms at the cellular level will likely help develop novel therapies in veterinary and human medicine.
Collapse
|
6
|
Azzaz HH, Kholif AE, Abd El Tawab AM, Hassaan NA, Vargas-Bello-Pérez E. A newly developed bacteriocin like substance to replace monensin in diets of lactating ewes. Anim Sci J 2023; 94:e13858. [PMID: 37485763 DOI: 10.1111/asj.13858] [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: 03/31/2023] [Revised: 06/07/2023] [Accepted: 06/13/2023] [Indexed: 07/25/2023]
Abstract
The aim of the present experiment was to evaluate the effect of feeding a newly produced bacteriocin-like substance (BLS) as a replacement for monensin in the diets of lactating ewes. In Experiment 1, the effects of BLS or monensin at 0.5, 1, 1.5, and 2 g/kg diet on in vitro ruminal fermentation were compared. In Experiment 2, 30 multiparous Barki ewes were divided into three treatments in a complete randomized design for 90 days. The ewes were fed a basal diet without supplementation or supplemented with monensin or BLS at 0.5 g/kg DM diet. In Experiment 1, the highest levels of BLS and monensin decreased gas production, while all levels of additives linearly decreased methane production. In Experiment 2, BLS increased nutrient digestibility. Additives increased ruminal total and individual volatile fatty acids and decreased ruminal ammonia-N. The BLS increased serum albumin and decreased the concentrations of serum liver enzymes, while both additives increased serum glucose and decreased urea-N. Additives increased daily production of milk, while the BLS treatment increased the feed efficiency. It is concluded that dietary inclusion of BLS at 0.5 g/kg DM for lactating ewes is recommended to replace monensin.
Collapse
Affiliation(s)
- Hossam H Azzaz
- Dairy Science Department, National Research Centre, Giza, Egypt
| | - Ahmed E Kholif
- Dairy Science Department, National Research Centre, Giza, Egypt
| | | | - Noha A Hassaan
- Department of Animal Production, National Research Centre, Giza, Egypt
| | - Einar Vargas-Bello-Pérez
- School of Agriculture, Policy and Development, Reading, UK
- Facultad de Zootecnia y Ecología, Universidad Autónoma de Chihuahua, Chihuahua, Mexico
| |
Collapse
|
7
|
Keresten V, Mikhelson K. Voltammetric Ion Sensing with Ionophore-Based Ion-Selective Electrodes Containing Internal Aqueous Solution, Improving Lifetime of Sensors. Membranes (Basel) 2022; 12:1048. [PMID: 36363603 PMCID: PMC9699433 DOI: 10.3390/membranes12111048] [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] [Received: 10/07/2022] [Revised: 10/21/2022] [Accepted: 10/25/2022] [Indexed: 06/16/2023]
Abstract
The possibility of voltammetric ion sensing is demonstrated, for the first time, for ion-selective electrodes (ISEs) containing an internal aqueous solution. ISEs selective to calcium, lithium and potassium ions are used as model systems. The internal solution of the ISEs contains a chloride salt of the respective cation and a ferrocenemethanol or ferrocyanide/ferricyanide redox couple. A platinum wire is used as the internal reference electrode. It is shown, theoretically and experimentally, that the dependence of oxidation and reduction peak potentials on the sample composition obeys the Nernst law, while the peak currents virtually do not depend on the sample composition. Thus, the electrode behavior is similar to that reported by Bakker's group for solid contact ISEs with ultra-thin membranes (200-300 nm). It is shown that the use of classical ISEs with relatively thick membranes (100-300 µm) and internal aqueous solution allows for the sensor lifetime of about one month. It is also shown that use of a suitable background electrolyte allows for improvement of the detection limits in voltammetric measurements with ISEs.
Collapse
|
8
|
Syromiatnikova V, Prokopeva A, Gomzikova M. Methods of the Large-Scale Production of Extracellular Vesicles. Int J Mol Sci 2022; 23:ijms231810522. [PMID: 36142433 PMCID: PMC9506336 DOI: 10.3390/ijms231810522] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 09/01/2022] [Accepted: 09/05/2022] [Indexed: 11/21/2022] Open
Abstract
To date, extracellular vesicles (EVs) have been extensively investigated as potential substitutes for cell therapy. Research has suggested their ability to overcome serious risks associated with the application of these cells. Although, the translation of EVs into clinical practice is hampered by the lack of a cheap reasonable way to obtain a clinically relevant number of EVs, an available method for the large-scale production of EVs ensures vesicles’ integrity, preserves their biological activity, and ensures they are well reproducible, providing homogeneity of the product from batch to batch. In this review, advances in the development of methods to increase EVs production are discussed. The existing approaches can be divided into the following: (1) those based on increasing the production of natural EVs by creating and using high capacity “cell factories”, (2) those based on the induction of EVs secretion under various cell stressors, and (3) those based on cell fragmentation with the creation of biomimetic vesicles. The aim of this review is to stimulate the introduction of EVs into clinical practice and to draw attention to the development of new methods of EVs production on a large scale.
Collapse
|
9
|
Calvo Alvarez E, D'Alessandro S, Proverbio D, Spada E, Perego R, Taramelli D, Basilico N, Parapini S. In Vitro Antiparasitic Activities of Monovalent Ionophore Compounds for Human and Canine Leishmaniases. Animals (Basel) 2022; 12. [PMID: 36139198 DOI: 10.3390/ani12182337] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 09/06/2022] [Accepted: 09/06/2022] [Indexed: 12/03/2022] Open
Abstract
The leishmaniases are vector-borne parasitic diseases affecting humans and animals, with high mortality rates in endemic countries. Infected dogs represent the main reservoir of infection. Disease control is mainly based on chemotherapy, which, at present, shows serious drawbacks both in humans and dogs. Therefore, the discovery or repurposing of new treatments is mandatory. Here, three monovalent ionophores (salinomycin, monensin, nigericin) were tested against promastigotes of Leishmania (L.) infantum, Leishmania tropica, and Leishmania braziliensis, and against amastigotes of L. infantum within human and, for the first time, canine macrophages. All three drugs were leishmanicidal against all Leishmania spp. promastigotes with IC50 values between 7.98 and 0.23 µM. Monensin and nigericin showed IC50 values < 1 µM, whereas salinomycin was the least active compound (IC50 > 4 µM). Notably, the ionophores killed L. infantum amastigotes within human THP-1 cells with IC50 values ranging from 1.67 to 1.93 µM, but they only reduced by 27−37% the parasite burden in L. infantum-infected canine macrophages, showing a host-specific efficacy. Moreover, a selective higher toxicity against canine macrophages was observed. Overall, repurposed ionophores have the potential to be further investigated as anti-Leishmania agents, but different drug options may be required to tackle human or canine leishmaniases.
Collapse
|
10
|
Pandey P, Khan F, Qari HA, Upadhyay TK, Alkhateeb AF, Oves M. Evidence of Metallic and Polyether Ionophores as Potent Therapeutic Drug Candidate in Cancer Management. Molecules 2022; 27:4708. [PMID: 35897885 PMCID: PMC9329979 DOI: 10.3390/molecules27154708] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/18/2022] [Accepted: 07/20/2022] [Indexed: 02/04/2023] Open
Abstract
Cancer remains one of the most crucial human malignancies with a higher mortality rate globally, and is predicted to escalate soon. Dysregulated ion homeostasis in cancerous cells prompted the researchers to investigate further ion homeostasis impeding agents as potent anticancerous agents. Reutilization of FDA-approved non-cancerous drugs has emerged as a practical approach to developing potent, cost-effective drugs for cancer treatment. Across the globe, most nations are incapable of fulfilling the medical demands of cancer patients due to costlier cancerous drugs. Therefore, we have inclined our review towards emphasizing recent advancements in cancer therapies involving ionophores utilization in exploring potent anticancer drugs. Numerous research reports have established the significant anticancerous potential of ionophores in several pre-clinical reports via modulating aberrant cell signaling pathways and enhancing antitumor immunity in immune cells. This review has mainly summarized the most significant ion homeostasis impeding agents, including copper, zinc, calcium, and polyether, that presented remarkable potential in cancer therapeutics via enhanced antitumor immunity and apoptosis induction. Altogether, this study could provide a robust future perspective for developing cost-effective anticancerous drugs rapidly and cost-effectively, thereby combating the limitations of currently available drugs used in cancer treatment.
Collapse
Affiliation(s)
- Pratibha Pandey
- Department of Biotechnology, Noida Institute of Engineering and Technology, Greater Noida 201306, India;
| | - Fahad Khan
- Department of Biotechnology, Noida Institute of Engineering and Technology, Greater Noida 201306, India;
| | - Huda A. Qari
- Department of Biological Science, Faculty of Sciences, King Abdulaziz University, Jeddah 21589, Saudi Arabia;
| | - Tarun Kumar Upadhyay
- Department of Biotechnology, Parul Institute of Applied Sciences and Animal Cell Culture and Immunobiochemistry Lab, Centre of Research for Development, Parul University, Vadodara 391760, India;
| | - Abdulhameed F. Alkhateeb
- Department of Electrical & Computer Engineering, Faculty of Engineering, King Abdulaziz University, Jeddah 21589, Saudi Arabia;
| | - Mohammad Oves
- Center of Excellence in Environmental Studies, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Sendai 980-8577, Japan
| |
Collapse
|
11
|
De Oliveira DMP, Forde BM, Phan MD, Steiner B, Zhang B, Zuegg J, El-Deeb IM, Li G, Keller N, Brouwer S, Harbison-Price N, Cork AJ, Bauer MJ, Alquethamy SF, Beatson SA, Roberts JA, Paterson DL, McEwan AG, Blaskovich MAT, Schembri MA, McDevitt CA, von Itzstein M, Walker MJ. Rescuing Tetracycline Class Antibiotics for the Treatment of Multidrug-Resistant Acinetobacter baumannii Pulmonary Infection. mBio 2022; 13:e0351721. [PMID: 35012353 DOI: 10.1128/mbio.03517-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Acinetobacter baumannii causes high mortality in ventilator-associated pneumonia patients, and antibiotic treatment is compromised by multidrug-resistant strains resistant to β-lactams, carbapenems, cephalosporins, polymyxins, and tetracyclines. Among COVID-19 patients receiving ventilator support, a multidrug-resistant A. baumannii secondary infection is associated with a 2-fold increase in mortality. Here, we investigated the use of the 8-hydroxyquinoline ionophore PBT2 to break the resistance of A. baumannii to tetracycline class antibiotics. In vitro, the combination of PBT2 and zinc with either tetracycline, doxycycline, or tigecycline was shown to be bactericidal against multidrug-resistant A. baumannii, and any resistance that did arise imposed a fitness cost. PBT2 and zinc disrupted metal ion homeostasis in A. baumannii, increasing cellular zinc and copper while decreasing magnesium accumulation. Using a murine model of pulmonary infection, treatment with PBT2 in combination with tetracycline or tigecycline proved efficacious against multidrug-resistant A. baumannii. These findings suggest that PBT2 may find utility as a resistance breaker to rescue the efficacy of tetracycline-class antibiotics commonly employed to treat multidrug-resistant A. baumannii infections. IMPORTANCE Within intensive care unit settings, multidrug-resistant (MDR) Acinetobacter baumannii is a major cause of ventilator-associated pneumonia, and hospital-associated outbreaks are becoming increasingly widespread. Antibiotic treatment of A. baumannii infection is often compromised by MDR strains resistant to last-resort β-lactam (e.g., carbapenems), polymyxin, and tetracycline class antibiotics. During the on-going COVID-19 pandemic, secondary bacterial infection by A. baumannii has been associated with a 2-fold increase in COVID-19-related mortality. With a rise in antibiotic resistance and a reduction in new antibiotic discovery, it is imperative to investigate alternative therapeutic regimens that complement the use of current antibiotic treatment strategies. Rescuing the efficacy of existing therapies for the treatment of MDR A. baumannii infection represents a financially viable pathway, reducing time, cost, and risk associated with drug innovation.
Collapse
|
12
|
Watson DJ, Meyers PR, Acquah KS, Dziwornu GA, Barnett CB, Wiesner L. Discovery of Novel Cyclic Ethers with Synergistic Antiplasmodial Activity in Combination with Valinomycin. Molecules 2021; 26:molecules26247494. [PMID: 34946577 PMCID: PMC8708982 DOI: 10.3390/molecules26247494] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 12/01/2021] [Accepted: 12/07/2021] [Indexed: 11/16/2022] Open
Abstract
With drug resistance threatening our first line antimalarial treatments, novel chemotherapeutics need to be developed. Ionophores have garnered interest as novel antimalarials due to their theorized ability to target unique systems found in the Plasmodium-infected erythrocyte. In this study, during the bioassay-guided fractionation of the crude extract of Streptomyces strain PR3, a group of cyclodepsipeptides, including valinomycin, and a novel class of cyclic ethers were identified and elucidated. Further study revealed that the ethers were cyclic polypropylene glycol (cPPG) oligomers that had leached into the bacterial culture from an extraction resin. Molecular dynamics analysis suggests that these ethers are able to bind cations such as K+, NH4+ and Na+. Combination studies using the fixed ratio isobologram method revealed that the cPPGs synergistically improved the antiplasmodial activity of valinomycin and reduced its cytotoxicity in vitro. The IC50 of valinomycin against P. falciparum NF54 improved by 4-5-fold when valinomycin was combined with the cPPGs. Precisely, it was improved from 3.75 ± 0.77 ng/mL to 0.90 ± 0.2 ng/mL and 0.75 ± 0.08 ng/mL when dosed in the fixed ratios of 3:2 and 2:3 of valinomycin to cPPGs, respectively. Each fixed ratio combination displayed cytotoxicity (IC50) against the Chinese Hamster Ovary cell line of 57-65 µg/mL, which was lower than that of valinomycin (12.4 µg/mL). These results indicate that combinations with these novel ethers may be useful in repurposing valinomycin into a suitable and effective antimalarial.
Collapse
Affiliation(s)
- Daniel J. Watson
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town 7700, South Africa;
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town 7700, South Africa; (P.R.M.); (K.S.A.)
- Correspondence:
| | - Paul R. Meyers
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town 7700, South Africa; (P.R.M.); (K.S.A.)
| | - Kojo Sekyi Acquah
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town 7700, South Africa; (P.R.M.); (K.S.A.)
- Department of Chemistry, University of Cape Town, Cape Town 7700, South Africa; (G.A.D.); (C.B.B.)
| | - Godwin A. Dziwornu
- Department of Chemistry, University of Cape Town, Cape Town 7700, South Africa; (G.A.D.); (C.B.B.)
| | | | - Lubbe Wiesner
- Division of Clinical Pharmacology, Department of Medicine, University of Cape Town, Cape Town 7700, South Africa;
| |
Collapse
|
13
|
Marques RDS, Cooke RF. Effects of Ionophores on Ruminal Function of Beef Cattle. Animals (Basel) 2021; 11:2871. [PMID: 34679890 DOI: 10.3390/ani11102871] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 09/14/2021] [Accepted: 09/29/2021] [Indexed: 01/19/2023] Open
Abstract
Ionophores have been widely used in the beef and dairy industry for decades to improve feed efficiency and performance by altering ruminal fermentation dynamics, increasing the level of propionate. Ionophores can also reduce ruminal proteolysis and ammonia synthesis, thus increasing the influx of protein into the small intestine in cattle, leading to improvements in performance and efficiency responses. Ionophores indirectly impact ruminal methanogenesis by decreasing the substrate used to produce methane. Despite the consistent benefits of using ionophores in cattle nutrition, their utilization is under public scrutiny due to concerns related to microbial adaptation. However, there is inconsistent evidence supporting these concerns, whereas ionophores are still an important dietary tool to enhance productivity and profitability in beef production systems.
Collapse
|
14
|
Bickerton LE, Docker A, Sterling AJ, Kuhn H, Duarte F, Beer PD, Langton MJ. Highly Active Halogen Bonding and Chalcogen Bonding Chloride Transporters with Non-Protonophoric Activity. Chemistry 2021; 27:11738-11745. [PMID: 34014001 PMCID: PMC8453555 DOI: 10.1002/chem.202101681] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Indexed: 12/14/2022]
Abstract
Synthetic anion transporters show much promise as potential anti-cancer agents and therapeutics for diseases associated with mis-regulation of protein anion channels. In such applications high activity and anion selectivity are crucial to overcome competing proton or hydroxide transport which dissipates cellular pH gradients. Here, highly active bidentate halogen bonding and chalcogen bonding anion carriers based on electron deficient iodo- and telluromethyl-triazole derivatives are reported. Anion transport experiments in lipid bilayer vesicles reveal record nanomolar chloride transport activity for the bidentate halogen bonding anion carrier, and remarkably high chloride over proton/hydroxide selectivity for the chalcogen bonding anionophore. Computational studies provide further insight into the role of sigma-hole mediated anion recognition and desolvation at the membrane interface. Comparison with hydrogen bonding analogues demonstrates the importance of employing sigma-hole donor motifs in synthetic anionophores for achieving both high transport activity and selectivity.
Collapse
Affiliation(s)
- Laura E. Bickerton
- Department of Chemistry Chemistry Research LaboratoryUniversity of OxfordMansfield RoadOxfordOX1 3TAUK
| | - Andrew Docker
- Department of Chemistry Chemistry Research LaboratoryUniversity of OxfordMansfield RoadOxfordOX1 3TAUK
| | - Alistair J. Sterling
- Department of Chemistry Chemistry Research LaboratoryUniversity of OxfordMansfield RoadOxfordOX1 3TAUK
| | - Heike Kuhn
- Department of Chemistry Chemistry Research LaboratoryUniversity of OxfordMansfield RoadOxfordOX1 3TAUK
| | - Fernanda Duarte
- Department of Chemistry Chemistry Research LaboratoryUniversity of OxfordMansfield RoadOxfordOX1 3TAUK
| | - Paul D. Beer
- Department of Chemistry Chemistry Research LaboratoryUniversity of OxfordMansfield RoadOxfordOX1 3TAUK
| | - Matthew J. Langton
- Department of Chemistry Chemistry Research LaboratoryUniversity of OxfordMansfield RoadOxfordOX1 3TAUK
| |
Collapse
|
15
|
Margolin L, Luchins J, Margolin D, Margolin M, Lefkowitz S. 20-Week Study of Clinical Outcomes of Over-the-Counter COVID-19 Prophylaxis and Treatment. J Evid Based Integr Med 2021; 26:2515690X211026193. [PMID: 34225463 PMCID: PMC8264737 DOI: 10.1177/2515690x211026193] [Citation(s) in RCA: 12] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Objectives and Setting. As the lethal COVID-19 pandemic enters its second year, the need for effective modalities of alleviation remains urgent. This includes modalities that can readily be used by the public to reduce disease spread and severity. Such preventive measures and early-stage treatments may temper the immediacy of demand for advanced anti-COVID measures (drugs, antibodies, vaccines) and help relieve strain also on other health system resources. Design and Participants. We present results of a clinical study with a multi-component OTC “core formulation” regimen used in a multiply exposed adult population. Analysis of clinical outcome data from our sample of over 100 subjects − comprised of roughly equal sized regimen-compliant (test) and non-compliant (control) groups meeting equivalent inclusion criteria − demonstrates a strong statistical significance in favor of use of the core formulations. Results. While both groups were moderate in size, the difference between them in outcomes over the 20-week study period was large and stark: Just under 4% of the compliant test group presented flu-like symptoms, but none of the test group was COVID-positive; whereas 20% of the non-compliant control group presented flu-like symptoms, three-quarters of whom (15% overall of the control group) were COVID-positive. Conclusions. Offering a low cost, readily implemented anti-viral approach, the study regimen may serve, at the least, as a stopgap modality and, perhaps, as a useful tool in combatting the pandemic.
Collapse
Affiliation(s)
- Leon Margolin
- Comprehensive Pain Management Institute, LLC, Columbus, OH, USA
| | - Jeremy Luchins
- Comprehensive Pain Management Institute, LLC, Columbus, OH, USA
| | - Daniel Margolin
- Comprehensive Pain Management Institute, LLC, Columbus, OH, USA
| | | | | |
Collapse
|
16
|
Keresten V, Solovyeva E, Mikhelson K. The Origin of the Non-Constancy of the Bulk Resistance of Ion-Selective Electrode Membranes within the Nernstian Response Range. Membranes (Basel) 2021; 11:membranes11050344. [PMID: 34067145 PMCID: PMC8150337 DOI: 10.3390/membranes11050344] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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: 04/14/2021] [Revised: 04/30/2021] [Accepted: 05/04/2021] [Indexed: 11/16/2022]
Abstract
The dependence of the bulk resistance of membranes of ionophore-based ion-selective electrodes (ISEs) on the composition of mixed electrolyte solutions, within the range of the Nernstian potentiometric response, is studied by chronopotentiometric and impedance measurements. In parallel to the resistance, water uptake by the membranes is also studied gravimetrically. The similarity of the respective curves is registered and explained in terms of heterogeneity of the membranes due to the presence of dispersed aqueous phase (water droplets). It is concluded that the electrochemical equilibrium is established between aqueous solution and the continuous organic phase, while the resistance refers to the membrane as whole, and water droplets hamper the charge transfer across the membranes. In this way, it is explained why the membrane bulk resistance is not constant within the range of the Nernstian potentiometric response of ISEs.
Collapse
|
17
|
Rüütel A, Yrjänä V, Kadam SA, Saar I, Ilisson M, Darnell A, Haav K, Haljasorg T, Toom L, Bobacka J, Leito I. Design, synthesis and application of carbazole macrocycles in anion sensors. Beilstein J Org Chem 2020; 16:1901-1914. [PMID: 32802207 PMCID: PMC7418101 DOI: 10.3762/bjoc.16.157] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [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: 04/21/2020] [Accepted: 07/16/2020] [Indexed: 11/23/2022] Open
Abstract
Carboxylate sensing solid-contact ion-selective electrodes (ISEs) were created to provide a proof-of-concept ISE development process covering all aspects from in silico ionophore design to functional sensor characterization. The biscarbazolylurea moiety was used to synthesize methylene-bridged macrocycles of different ring size aiming to fine tune selectivity towards different carboxylates. Cyclization was achieved with two separate strategies, using either amide synthesis to access up to –[CH2]10– macrocycles or acyl halides to access up to –[CH2]14– macrocycles. Seventy-five receptor–anion complexes were modelled and studied with COSMO-RS, in addition to all free host molecules. In order to predict initial selectivity towards carboxylates, 1H NMR relative titrations were used to quantify binding in DMSO-d6/H2O solvent systems of two proportions – 99.5%:0.5% m/m and 90.0%:10.0% m/m, suggesting initial selectivity towards acetate. Three ionophores were selected for successful sensor prototype development and characterization. The constructed ion-selective electrodes showed higher selectivity towards benzoate than acetate, i.e., the selectivity patterns of the final sensors deviated from that predicted by the classic titration experiments. While the binding constants obtained by NMR titration in DMSO-d6/H2O solvent systems provided important guidance for sensor development, the results obtained in this work emphasize the importance of evaluating the binding behavior of receptors in real sensor membranes.
Collapse
Affiliation(s)
- Alo Rüütel
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia, https://analytical.chem.ut.ee
| | - Ville Yrjänä
- Johan Gadolin Process Chemistry Centre, Laboratory of Molecular Science and Engineering, Åbo Akademi University, Biskopsgatan 8, FI-20500 Turku/Åbo, Finland
| | - Sandip A Kadam
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia, https://analytical.chem.ut.ee
| | - Indrek Saar
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia, https://analytical.chem.ut.ee
| | - Mihkel Ilisson
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia, https://analytical.chem.ut.ee
| | - Astrid Darnell
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia, https://analytical.chem.ut.ee
| | - Kristjan Haav
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia, https://analytical.chem.ut.ee
| | - Tõiv Haljasorg
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia, https://analytical.chem.ut.ee
| | - Lauri Toom
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia, https://analytical.chem.ut.ee
| | - Johan Bobacka
- Johan Gadolin Process Chemistry Centre, Laboratory of Molecular Science and Engineering, Åbo Akademi University, Biskopsgatan 8, FI-20500 Turku/Åbo, Finland
| | - Ivo Leito
- Institute of Chemistry, University of Tartu, Ravila 14a, 50411 Tartu, Estonia, https://analytical.chem.ut.ee
| |
Collapse
|
18
|
Sandler ZJ, Firpo MR, Omoba OS, Vu MN, Menachery VD, Mounce BC. Novel Ionophores Active against La Crosse Virus Identified through Rapid Antiviral Screening. Antimicrob Agents Chemother 2020; 64:e00086-20. [PMID: 32284379 DOI: 10.1128/AAC.00086-20] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 04/03/2020] [Indexed: 12/18/2022] Open
Abstract
Bunyaviruses are significant human pathogens, causing diseases ranging from hemorrhagic fevers to encephalitis. Among these viruses, La Crosse virus (LACV), a member of the California serogroup, circulates in the eastern and midwestern United States. While LACV infection is often asymptomatic, dozens of cases of encephalitis are reported yearly. Unfortunately, no antivirals have been approved to treat LACV infection. Here, we developed a method to rapidly test potential antivirals against LACV infection. From this screen, we identified several potential antiviral molecules, including known antivirals. Additionally, we identified many novel antivirals that exhibited antiviral activity without affecting cellular viability. Valinomycin, a potassium ionophore, was among our top targets. We found that valinomycin exhibited potent anti-LACV activity in multiple cell types in a dose-dependent manner. Valinomycin did not affect particle stability or infectivity, suggesting that it may preclude virus replication by altering cellular potassium ions, a known determinant of LACV entry. We extended these results to other ionophores and found that the antiviral activity of valinomycin extended to other viral families, including bunyaviruses (Rift Valley fever virus, Keystone virus), enteroviruses (coxsackievirus, rhinovirus), flavirivuses (Zika virus), and coronaviruses (human coronavirus 229E [HCoV-229E] and Middle East respiratory syndrome CoV [MERS-CoV]). In all viral infections, we observed significant reductions in virus titer in valinomycin-treated cells. In sum, we demonstrate the importance of potassium ions to virus infection, suggesting a potential therapeutic target to disrupt virus replication.
Collapse
|
19
|
Hickey EE, Page SW, Trott DJ. In vitro efficacy and pharmacodynamic profiles of four polyether ionophores against methicillin-resistant Staphylococcus spp. J Vet Pharmacol Ther 2020; 43:499-507. [PMID: 32420646 DOI: 10.1111/jvp.12871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 11/06/2019] [Revised: 04/15/2020] [Accepted: 04/15/2020] [Indexed: 11/28/2022]
Abstract
The objective of this study was to determine the minimum inhibitory concentrations (MICs) and pharmacodynamic profiles of four ionophores (lasalocid, monensin, narasin and salinomycin) against staphylococcal isolates from clinical cases of human and veterinary staphylococcal infections, and to determine the effect of methicillin resistance on the antimicrobial activity of ionophores. Broth microdilution MIC testing was used to determine antimicrobial activity against 156 staphylococcal isolates of human and veterinary origin. Pharmacodynamic profiles were examined using time-kill kinetics profiles against an ATCC type strain of Staphylococcus aureus and a clinical isolate of methicillin-resistant Staphylococcus pseudintermedius. All tests were performed in accordance with CLSI guidelines. All four ionophores demonstrated antimicrobial activity against methicillin-resistant staphylococci at concentrations similar to those observed for methicillin-susceptible isolates of the same species. Testing of human and veterinary MRSA isolates also showed that MIC values were not influenced by the host origin of the isolates. Pharmacodynamic profiles were similar for both isolates tested across all four ionophores, with similar reductions in viable cell counts being observed over an 18- to 24-hr period. Lasalocid, monensin, narasin and salinomycin all demonstrated antimicrobial activity against staphylococcal isolates of human and veterinary origins, with activity being unaffected by methicillin resistance status, although some Staphylococcus species-specific effects were observed that require further investigation.
Collapse
Affiliation(s)
- Elizabeth E Hickey
- Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, The University of Adelaide, SA, Australia
| | | | - Darren J Trott
- Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, The University of Adelaide, SA, Australia
| |
Collapse
|
20
|
Abstract
The aim of this study was to determine the susceptibility of Lactobacillus bacteria to selected coccidiostats. Seventy-five Lactobacillus isolates obtained from chickens were classified by MALDI-TOF mass spectrometry and 16S rDNA restriction analysis into seven species, among which L. salivarius (33%) and L. johnsonii (24%) were dominant. Susceptibility of lactobacilli to coccidiostats was determined by broth microdilution method. The ranges of minimum inhibitory concentrations (MICs) were 0.5-≥128 µg/ml for monensin, 0.125-8 µg/ml for salinomycin, ≤0.03-2 µg/ml for lasalocid A, and 4-16 µg/ml for robenidine. Coccidiostats in low concentrations inhibited in vitro growth of most lactobacilli and therefore there is a high probability that administration of this drugs to chickens would reduce the number of lactobacilli in the gut.
Collapse
Affiliation(s)
- Marta Dec
- Department of Veterinary Prevention and Avian Diseases, Institute of Biological Bases of Animal Diseases, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Akademicka 12, 20-033 Lublin, Poland
| | - Andrzej Puchalski
- Department of Veterinary Prevention and Avian Diseases, Institute of Biological Bases of Animal Diseases, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Akademicka 12, 20-033 Lublin, Poland
| | - Dagmara Stępień-Pyśniak
- Department of Veterinary Prevention and Avian Diseases, Institute of Biological Bases of Animal Diseases, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Akademicka 12, 20-033 Lublin, Poland
| | - Agnieszka Marek
- Department of Veterinary Prevention and Avian Diseases, Institute of Biological Bases of Animal Diseases, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Akademicka 12, 20-033 Lublin, Poland
| | - Renata Urban-Chmiel
- Department of Veterinary Prevention and Avian Diseases, Institute of Biological Bases of Animal Diseases, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Akademicka 12, 20-033 Lublin, Poland
| |
Collapse
|
21
|
Chan WY, Hickey EE, Page SW, Trott DJ, Hill PB. Biofilm production by pathogens associated with canine otitis externa, and the antibiofilm activity of ionophores and antimicrobial adjuvants. J Vet Pharmacol Ther 2019; 42:682-692. [PMID: 31503362 DOI: 10.1111/jvp.12811] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [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: 06/21/2019] [Revised: 08/13/2019] [Accepted: 08/21/2019] [Indexed: 11/27/2022]
Abstract
Otitis externa (OE) is a frequently reported disorder in dogs associated with secondary infections by Staphylococcus, Pseudomonas and yeast pathogens. The presence of biofilms may play an important role in the resistance of otic pathogens to antimicrobial agents. Biofilm production of twenty Staphylococcus pseudintermedius and twenty Pseudomonas aeruginosa canine otic isolates was determined quantitatively using a microtiter plate assay, and each isolate was classified as a strong, moderate, weak or nonbiofilm producer. Minimum biofilm eradication concentration (MBEC) of two ionophores (narasin and monensin) and three adjuvants (N-acetylcysteine (NAC), Tris-EDTA and disodium EDTA) were investigated spectrophotometrically (OD570nm ) and quantitatively (CFU/ml) against selected Staphylococcus and Pseudomonas biofilm cultures. Concurrently, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of planktonic cultures were assessed. 16/20 of the S. pseudintermedius clinical isolates were weak biofilm producers. 19/20 P. aeruginosa clinical isolates produced biofilms and were distributed almost equally as weak, moderate and strong biofilm producers. While significant antibiofilm activity was observed, no MBEC was achieved with narasin or monensin. The MBEC for NAC ranged from 5,000-10,000 µg/ml and from 20,000-80,000 µg/ml against S. pseudintermedius and P. aeruginosa, respectively. Tris-EDTA eradicated P. aeruginosa biofilms at concentrations ranging from 6,000/1,900 to 12,000/3,800 µg/ml. The MBEC was up to 16-fold and eightfold higher than the MIC/MBC of NAC and Tris-EDTA, respectively. Disodium EDTA reduced biofilm growth of both strains at concentrations of 470 µg/ml and higher. It can be concluded that biofilm production is common in pathogens associated with canine OE. NAC and Tris-EDTA are effective antibiofilm agents in vitro that could be considered for the treatment of biofilm-associated OE in dogs.
Collapse
Affiliation(s)
- Wei Yee Chan
- Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, SA, Australia.,Faculty of Veterinary Medicine, Universiti Putra Malaysia, Selangor, Malaysia
| | - Elizabeth E Hickey
- Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, SA, Australia
| | | | - Darren J Trott
- Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, SA, Australia
| | - Peter B Hill
- Australian Centre for Antimicrobial Resistance Ecology, School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, SA, Australia
| |
Collapse
|
22
|
Robinson K, Becker S, Xiao Y, Lyu W, Yang Q, Zhu H, Yang H, Zhao J, Zhang G. Differential Impact of Subtherapeutic Antibiotics and Ionophores on Intestinal Microbiota of Broilers. Microorganisms 2019; 7:microorganisms7090282. [PMID: 31443457 PMCID: PMC6780560 DOI: 10.3390/microorganisms7090282] [Citation(s) in RCA: 30] [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: 07/22/2019] [Revised: 08/15/2019] [Accepted: 08/20/2019] [Indexed: 01/05/2023] Open
Abstract
Antimicrobial growth promoters (AGPs) are commonly used in the livestock industry at subtherapeutic levels to improve production efficiency, which is achieved mainly through modulation of the intestinal microbiota. However, how different classes of AGPs, particularly ionophores, regulate the gut microbiota remains unclear. In this study, male Cobb broiler chickens were supplemented for 14 days with or without one of five commonly used AGPs including three classical antibiotics (bacitracin methylene disalicylate, tylosin, and virginiamycin) and two ionophores (monensin and salinomycin) that differ in antimicrobial spectrum and mechanisms. Deep sequencing of the V3-V4 region of the bacterial 16S rRNA gene revealed that two ionophores drastically reduced a number of rare bacteria resulting in a significant decrease in richness and a concomitant increase in evenness of the cecal microbiota, whereas three antibiotics had no obvious impact. Although each AGP modulated the gut microbiota differently, the closer the antibacterial spectrum of AGPs, the more similarly the microbiota was regulated. Importantly, all AGPs had a strong tendency to enrich butyrate- and lactic acid-producing bacteria, while reducing bile salt hydrolase-producing bacteria, suggestive of enhanced metabolism and utilization of dietary carbohydrates and lipids and improved energy harvest, which may collectively be responsible for the growth-promoting effect of AGPs.
Collapse
Affiliation(s)
- Kelsy Robinson
- Department of Animal and Food Sciences, Oklahoma State University, Stillwater, OK 74078, USA
| | - Sage Becker
- Department of Animal and Food Sciences, Oklahoma State University, Stillwater, OK 74078, USA
| | - Yingping Xiao
- Institute of Quality and Standards for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Wentao Lyu
- Department of Animal and Food Sciences, Oklahoma State University, Stillwater, OK 74078, USA
- Institute of Quality and Standards for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Qing Yang
- Department of Animal and Food Sciences, Oklahoma State University, Stillwater, OK 74078, USA
| | - Huiling Zhu
- Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan 430000, China
| | - Hua Yang
- Institute of Quality and Standards for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Jiangchao Zhao
- Department of Animal Science, Division of Agriculture, University of Arkansas, Fayetteville, AR 72701, USA
| | - Guolong Zhang
- Department of Animal and Food Sciences, Oklahoma State University, Stillwater, OK 74078, USA.
| |
Collapse
|
23
|
Naletova I, Satriano C, Curci A, Margiotta N, Natile G, Arena G, La Mendola D, Nicoletti VG, Rizzarelli E. Cytotoxic phenanthroline derivatives alter metallostasis and redox homeostasis in neuroblastoma cells. Oncotarget 2018; 9:36289-36316. [PMID: 30555630 PMCID: PMC6284747 DOI: 10.18632/oncotarget.26346] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [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: 09/17/2018] [Accepted: 11/01/2018] [Indexed: 02/06/2023] Open
Abstract
Copper homeostasis is generally investigated focusing on a single component of the metallostasis network. Here we address several of the factors controlling the metallostasis for neuroblastoma cells (SH-SY5Y) upon treatment with 2,9-dimethyl-1,10-phenanthroline-5,6-dione (phendione) and 2,9-dimethyl-1,10-phenanthroline (cuproindione). These compounds bind and transport copper inside cells, exert their cytotoxic activity through the induction of oxidative stress, causing apoptosis and alteration of the cellular redox and copper homeostasis network. The intracellular pathway ensured by copper transporters (Ctr1, ATP7A), chaperones (CCS, ATOX, COX 17, Sco1, Sco2), small molecules (GSH) and transcription factors (p53) is scrutinised.
Collapse
Affiliation(s)
- Irina Naletova
- Department of Chemical Sciences, University of Catania, Catania, Italy
- Consorzio Interuniversitario di Ricerca in Chimica dei Metalli nei Sistemi Biologici (CIRCMSB), Bari, Italy
| | - Cristina Satriano
- Department of Chemical Sciences, University of Catania, Catania, Italy
- Consorzio Interuniversitario di Ricerca in Chimica dei Metalli nei Sistemi Biologici (CIRCMSB), Bari, Italy
| | - Alessandra Curci
- Consorzio Interuniversitario di Ricerca in Chimica dei Metalli nei Sistemi Biologici (CIRCMSB), Bari, Italy
- Department of Chemistry, University of Bari ‘Aldo Moro’, Bari, Italy
| | - Nicola Margiotta
- Consorzio Interuniversitario di Ricerca in Chimica dei Metalli nei Sistemi Biologici (CIRCMSB), Bari, Italy
- Department of Chemistry, University of Bari ‘Aldo Moro’, Bari, Italy
| | - Giovanni Natile
- Consorzio Interuniversitario di Ricerca in Chimica dei Metalli nei Sistemi Biologici (CIRCMSB), Bari, Italy
- Department of Chemistry, University of Bari ‘Aldo Moro’, Bari, Italy
| | - Giuseppe Arena
- Department of Chemical Sciences, University of Catania, Catania, Italy
- Consorzio Interuniversitario di Ricerca in Chimica dei Metalli nei Sistemi Biologici (CIRCMSB), Bari, Italy
| | - Diego La Mendola
- Consorzio Interuniversitario di Ricerca in Chimica dei Metalli nei Sistemi Biologici (CIRCMSB), Bari, Italy
- Department of Pharmacy, University of Pisa, Pisa, Italy
| | - Vincenzo Giuseppe Nicoletti
- Consorzio Interuniversitario di Ricerca in Chimica dei Metalli nei Sistemi Biologici (CIRCMSB), Bari, Italy
- Section of Medical Biochemistry, Department of Biomedical and Biotechnological Sciences (BIOMETEC), University of Catania, Catania, Italy
| | - Enrico Rizzarelli
- Department of Chemical Sciences, University of Catania, Catania, Italy
- Consorzio Interuniversitario di Ricerca in Chimica dei Metalli nei Sistemi Biologici (CIRCMSB), Bari, Italy
| |
Collapse
|
24
|
Kaushik V, Yakisich JS, Kumar A, Azad N, Iyer AKV. Ionophores: Potential Use as Anticancer Drugs and Chemosensitizers. Cancers (Basel) 2018; 10:cancers10100360. [PMID: 30262730 PMCID: PMC6211070 DOI: 10.3390/cancers10100360] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [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: 08/23/2018] [Revised: 09/13/2018] [Accepted: 09/21/2018] [Indexed: 01/08/2023] Open
Abstract
Ion homeostasis is extremely important for the survival of both normal as well as neoplastic cells. The altered ion homeostasis found in cancer cells prompted the investigation of several ionophores as potential anticancer agents. Few ionophores, such as Salinomycin, Nigericin and Obatoclax, have demonstrated potent anticancer activities against cancer stem-like cells that are considered highly resistant to chemotherapy and responsible for tumor relapse. The preclinical success of these compounds in in vitro and in vivo models have not been translated into clinical trials. At present, phase I/II clinical trials demonstrated limited benefit of Obatoclax alone or in combination with other anticancer drugs. However, future development in targeted drug delivery may be useful to improve the efficacy of these compounds. Alternatively, these compounds may be used as leading molecules for the development of less toxic derivatives.
Collapse
Affiliation(s)
- Vivek Kaushik
- Department of Pharmaceutical Sciences, School of Pharmacy, Hampton University, Hampton, VA 23668, USA.
| | - Juan Sebastian Yakisich
- Department of Pharmaceutical Sciences, School of Pharmacy, Hampton University, Hampton, VA 23668, USA.
| | - Anil Kumar
- Great Plains Health, North Platte, NE 69101, USA.
| | - Neelam Azad
- Department of Pharmaceutical Sciences, School of Pharmacy, Hampton University, Hampton, VA 23668, USA.
| | - Anand K V Iyer
- Department of Pharmaceutical Sciences, School of Pharmacy, Hampton University, Hampton, VA 23668, USA.
| |
Collapse
|
25
|
Bagheri Varzaneh M, Klevenhusen F, Zebeli Q, Petri R. Scrophularia striata Extract Supports Rumen Fermentation and Improves Microbial Diversity in vitro Compared to Monensin. Front Microbiol 2018; 9:2164. [PMID: 30283414 PMCID: PMC6156526 DOI: 10.3389/fmicb.2018.02164] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [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: 04/17/2018] [Accepted: 08/23/2018] [Indexed: 12/17/2022] Open
Abstract
In the search for natural alternatives to antibiotic feed additives, we compared the efficacy of two doses of Scrophularia striata extract [S. striata-Low at 40 and S. striata-High at 80 mg g-1 dry matter (DM)] with monensin (monensin) and a negative control in the modulation of rumen fermentation, methane production and microbial abundance in vitro. Microbes were investigated using qPCR and 16S rRNA targeted sequencing. Data showed that the addition of S. striata increased production of total short chain fatty acids (SCFA) in comparison to both monensin and control (P = 0.04). The addition of S. striata increased acetate production, and increased propionate at the higher dosage (P < 0.001). Supplementation of S. striata lowered methane production (P < 0.001) compared to control but with no effect compared to monensin. Ammonia concentration decreased by 52% (P < 0.001) with S. striata-High supplementation (4.14 mmol L-1) compared to control, which was greater than that of monensin (36%). The diversity of rumen bacteria was reduced (P < 0.001) for monensin and S. striata for both the number of observed OTUs and the Chao1 index. Quantitative analysis of Protozoa showed a decrease in the monensin treatment (P = 0.05) compared to control. Archaea copy numbers decreased equally in both S. striata-High and monensin treatments compared to the control group. Supplementation with S. striata increased relative abundances of Fibrobacteres (P < 0.001) and Planctomycetes (P = 0.001) in comparison to both the control and monensin treatments. Significant negative correlations were observed between the abundances of Bacteroides, Fusobacterium, and Succinivibrio genera and methane (r > -0.71; P ≤ 0.001). The abundance of Fibrobacter genera and total SCFA (r = 0.86), acetate (r = 0.75), and valerate (r = -0.51; P < 0.001) correlated positively. These results suggest that S. striata supplementation at 80 mg g-1 DM inclusion, similar to monensin, supports rumen fermentation, lowers methane and ammonia production. However, S. striata supported rumen fermentation toward higher total SCFA and propionate production, while unlike monensin still supported a diverse rumen microbiome and an increase in cellulolytic bacteria such as Fibrobacter.
Collapse
Affiliation(s)
- Maryam Bagheri Varzaneh
- Department of Agriculture, Iranian Research Organization for Science and Technology, Tehran, Iran
| | - Fenja Klevenhusen
- Institute of Animal Nutrition and Functional Plant Compounds, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Qendrim Zebeli
- Institute of Animal Nutrition and Functional Plant Compounds, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Renee Petri
- Institute of Animal Nutrition and Functional Plant Compounds, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria
| |
Collapse
|
26
|
Borgström B, Huang X, Hegardt C, Oredsson S, Strand D. Structure-Activity Relationships in Salinomycin: Cytotoxicity and Phenotype Selectivity of Semi-synthetic Derivatives. Chemistry 2016; 23:2077-2083. [PMID: 27740704 DOI: 10.1002/chem.201603621] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [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: 07/29/2016] [Indexed: 01/09/2023]
Abstract
The ionophore salinomycin has attracted attention for its exceptional ability to selectively reduce the proportion of cells with stem-like properties in cancer cell populations of varying origin. Targeting the tumorigenicity of such cells is of interest as they are implicated in recurrence, metastasis, and drug resistance. Structural derivatives of salinomycin are thus sought after, both as tools for probing the molecular mechanism(s) underlying the observed phenotype effects, and for improving selectivity and activity against cancer stem cells. Synthetic strategies for modification of each of the directly accessible functional groups of salinomycin are presented and the resulting library of analogues was investigated to establish structure-activity relationships, both with respect to cytotoxicity and phenotype selectivity in breast cancer cells. 20-O-Acylated derivatives stand out by exhibiting both improved selectivity and activity. Mechanistically, the importance of the ionophore properties of salinomycin is highlighted by a significant loss of activity by modifications directly interfering with either of the two primary ion coordinating motifs in salinomycin, the C11 ketone and the C1 carboxylate.
Collapse
Affiliation(s)
- Björn Borgström
- Centre for Analysis and Synthesis, Lund University, Box 124, 22100, Lund, Sweden
| | - Xiaoli Huang
- Department of Biology, Lund University, Sölvegatan 35/37, 223 62, Lund, Sweden
| | - Cecilia Hegardt
- Division of Oncology and Pathology, Department of Clinical Sciences, Lund University, Medicon Village, 223 81, Lund, Sweden
| | - Stina Oredsson
- Department of Biology, Lund University, Sölvegatan 35/37, 223 62, Lund, Sweden
| | - Daniel Strand
- Centre for Analysis and Synthesis, Lund University, Box 124, 22100, Lund, Sweden
| |
Collapse
|
27
|
Abstract
Exceptionally powerful anion receptors have been constructed by placing squaramide groups in axial positions on a steroidal framework. The steroid preorganizes the squaramide NH groups such that they can act cooperatively on a bound anion, while maintaining solubility in nonpolar media. The acidic NH groups confer higher affinities than previously-used ureas or thioureas. Binding constants exceeding 10(14) M(-1) have been measured for tetraethylammonium salts in chloroform by employing a variation of Cram's extraction procedure. The receptors have also been studied as transmembrane anion carriers in unilamellar vesicles. Unusually their activities do not correlate with anion affinities, thus suggesting an upper limit for binding strength in the design of anion carriers.
Collapse
Affiliation(s)
- Sophie J Edwards
- School of Chemistry, University of Bristol, Cantock*s CloseBristol BS8 1TS (UK)
| | - Hennie Valkenier
- School of Chemistry, University of Bristol, Cantock*s CloseBristol BS8 1TS (UK)
| | | | - Philip A Gale
- Chemistry, University of SouthamptonSouthampton, SO17 1BJ (UK)
| | - Anthony P Davis
- School of Chemistry, University of Bristol, Cantock*s CloseBristol BS8 1TS (UK)
| |
Collapse
|
28
|
Senouci-Rezkallah K, Jobin MP, Schmitt P. Adaptive responses of Bacillus cereus ATCC14579 cells upon exposure to acid conditions involve ATPase activity to maintain their internal pH. Microbiologyopen 2015; 4:313-322. [PMID: 25740257 PMCID: PMC4398511 DOI: 10.1002/mbo3.239] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 12/17/2014] [Accepted: 12/22/2014] [Indexed: 11/08/2022] Open
Abstract
This study examined the involvement of ATPase activity in the acid tolerance response (ATR) of Bacillus cereus ATCC14579 strain. In the current work, B. cereus cells were grown in anaerobic chemostat culture at external pH (pHe ) 7.0 or 5.5 and at a growth rate of 0.2 h-1 . Population reduction and internal pH (pHi ) after acid shock at pH 4.0 was examined either with or without ATPase inhibitor N,N'-dicyclohexylcarbodiimide (DCCD) and ionophores valinomycin and nigericin. Population reduction after acid shock at pH 4.0 was strongly limited in cells grown at pH 5.5 (acid-adapted cells) compared with cells grown at pH 7.0 (unadapted cells), indicating that B. cereus cells grown at low pHe were able to induce a significant ATR and Exercise-induced increase in ATPase activity. However, DCCD and ionophores had a negative effect on the ability of B. cereus cells to survive and maintain their pHi during acid shock. When acid shock was achieved after DCCD treatment, pHi was markedly dropped in unadapted and acid-adapted cells. The ATPase activity was also significantly inhibited by DCCD and ionophores in acid-adapted cells. Furthermore, transcriptional analysis revealed that atpB (ATP beta chain) transcripts was increased in acid-adapted cells compared to unadapted cells before and after acid shock. Our data demonstrate that B. cereus is able to induce an ATR during growth at low pH. These adaptations depend on the ATPase activity induction and pHi homeostasis. Our data demonstrate that the ATPase enzyme can be implicated in the cytoplasmic pH regulation and in acid tolerance of B. cereus acid-adapted cells.
Collapse
Affiliation(s)
- Khadidja Senouci-Rezkallah
- UMR408 Sécurité et Qualité des Produits d'Origine Végétale, INRA, Université d'Avignon, 84914, Avignon, France.,Faculté des Sciences de la Nature et de la Vie, Université de Mascara, Mascara, Algérie.,Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - Michel P Jobin
- UMR408 Sécurité et Qualité des Produits d'Origine Végétale, INRA, Université d'Avignon, 84914, Avignon, France
| | - Philippe Schmitt
- UMR408 Sécurité et Qualité des Produits d'Origine Végétale, INRA, Université d'Avignon, 84914, Avignon, France
| |
Collapse
|
29
|
Tunuguntla RH, Bangar MA, Kim K, Stroeve P, Grigoropoulos C, Ajo-Franklin CM, Noy A. Bioelectronic light-gated transistors with biologically tunable performance. Adv Mater 2015; 27:831-836. [PMID: 25410490 DOI: 10.1002/adma.201403988] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 10/13/2014] [Indexed: 06/04/2023]
Abstract
Light-activated bioelectronic silicon nanowire transistor devices are made by fusing proteoliposomes containing a bacteriorhodopsin (bR) proton pump onto the nanowire surface. Under green-light illumination, bR pumps protons toward the nanowire, and the pH gradient developed by the pump changes the transistor output. Furthermore, co-assembly of small biomolecules that alter the bilayer permeability to other ions can upregulate and downregulate the response of field-effect transistor devices.
Collapse
Affiliation(s)
- Ramya H Tunuguntla
- Biology and Biotechnology Division, Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California, 94550, USA; Materials Science and Chemical Engineering Department, University of California Davis, Davis, California, 95616, USA; The Molecular Foundry, Materials Sciences Division and
| | | | | | | | | | | | | |
Collapse
|
30
|
Oliveira DM, Chalfun-Junior A, Chizzotti ML, Barreto HG, Coelho TC, Paiva LV, Coelho CP, Teixeira PD, Schoonmaker JP, Ladeira MM. Expression of genes involved in lipid metabolism in the muscle of beef cattle fed soybean or rumen-protected fat, with or without monensin supplementation. J Anim Sci 2014; 92:5426-36. [PMID: 25403202 DOI: 10.2527/jas.2014-7855] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Degree of unsaturation of fatty acids, which is influenced by lipid source and level of metabolism in the rumen, is a major determinant in how dietary lipids affect genes that regulate beef marbling. A total of 28 Red Norte bulls with an initial live weight of 361±32 kg (P>0.05) were used in a completely randomized experimental design to analyze the expression of genes that are involved in lipid metabolism in the longissimus dorsi (LD) when diets contained soybean grain or rumen-protected fat, with or without monensin. Treatments were arranged as a 2×2 factorial, with 4 treatments and 7 replicates per treatment. Half of the animals that received soybean or rumen-protected fat were supplemented with 230 mg head(-1) d(-1) of monensin. Gene expression was analyzed by reverse-transcription quantitative PCR (RT-qPCR). Expression of sterol regulatory element-binding protein-1c (SREBP-1c) in the LD muscle was not affected by lipid source or monensin (P>0.05). There was an interaction effect (P<0.05) between lipid source and monensin for peroxisome proliferator-activated receptor α (PPAR-α) and stearoyl-CoA desaturase (SCD) expression, where greater gene expression was found in animals fed soybean plus monensin and the lower gene expression was found in animals fed rumen-protected fat plus monensin. Expression of lipoprotein lipase (LPL) and fatty acid-binding protein 4 (FABP4) were greater (P<0.05) in the LD muscle of animals fed soybean. Monensin had no effect on LPL and FABP4 expression when soybean without monensin was fed, but when rumen-protected fat was fed, monensin increased LPL expression and decreased FABP4 expression (P<0.05). Linoleic and arachidonic acids had negative correlations (P<0.05) with the expression of PPAR-α, SCD, FABP4, and LPL genes. PPAR-α gene expression was not correlated with SREBP-1c but was positively correlated with SCD, FABP4, LPL, and glutathione peroxidase (GPX1) gene expression (P<0.001). Lipid sources and monensin interact and alter the expression of PPAR-α, SCD, acetyl CoA carboxylase α (ACACA), LPL, FABP4, and GPX1. These changes in gene expression were most associated with arachidonic and α-linolenic acids and the ability of lipid sources and monensin to increase these fatty acids in tissues.
Collapse
Affiliation(s)
- D M Oliveira
- Department of Animal Science, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil, 37.200-000
| | - A Chalfun-Junior
- Department of Biology, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil, 37.200-000
| | - M L Chizzotti
- Department of Animal Science, Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil, 36.570-000
| | - H G Barreto
- Department of Agricultural Sciences, Universidade Federal de Tocantins, Gurupi, Tocantins, Brazil, 77.402-970
| | - T C Coelho
- Department of Animal Science, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil, 37.200-000
| | - L V Paiva
- Department of Chemistry, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil, 37.200-000
| | - C P Coelho
- Department of Animal Science, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil, 37.200-000
| | - P D Teixeira
- Department of Animal Science, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil, 37.200-000
| | - J P Schoonmaker
- Department of Animal Science, Purdue University, West Lafayette, IN 47906
| | - M M Ladeira
- Department of Animal Science, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil, 37.200-000
| |
Collapse
|
31
|
Luhavaya H, Williams SR, Hong H, Gonzaga de Oliveira L, Leadlay PF. Site-specific modification of the anticancer and antituberculosis polyether salinomycin by biosynthetic engineering. Chembiochem 2014; 15:2081-5. [PMID: 25155178 PMCID: PMC4515104 DOI: 10.1002/cbic.201402300] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Indexed: 11/23/2022]
Abstract
The complex bis-spiroacetal polyether ionophore salinomycin has been identified as a uniquely selective agent against cancer stem cells and is also strikingly effective in an animal model of latent tuberculosis. The basis for these important activities is unknown. We show here that deletion of the salE gene abolishes salinomycin production and yields two new analogues, in both of which the C18C19 cis double bond is replaced by a hydroxy group stereospecifically located at C19, but which differ from each other in the configuration of the bis-spiroacetal. These results identify SalE as a novel dehydratase and demonstrate that biosynthetic engineering can be used to redirect the reaction cascade of oxidative cyclization to yield new salinomycin analogues for use in mechanism-of-action studies.
Collapse
Affiliation(s)
- Hanna Luhavaya
- Department of Biochemistry, University of Cambridge80 Tennis Court Road, Cambridge CB2 1GA (UK)
| | - Simon R Williams
- University Chemical Laboratory, University of CambridgeLensfield Road, Cambridge CB2 1EW (UK)
| | - Hui Hong
- Department of Biochemistry, University of Cambridge80 Tennis Court Road, Cambridge CB2 1GA (UK)
| | - Luciana Gonzaga de Oliveira
- Department of Organic Chemistry, University of Campinas, UNICAMP, Cidade Universitária Zeferino Vaz s/nP.O. Box 6154, 13083-970, Campinas, SP (Brazil)
| | - Peter F Leadlay
- Department of Biochemistry, University of Cambridge80 Tennis Court Road, Cambridge CB2 1GA (UK)
| |
Collapse
|
32
|
Doane M, Sarenbo S. Antibiotic usage in 2013 on a dairy CAFO in NY State, USA. Infect Ecol Epidemiol 2014; 4:24259. [PMID: 24891936 PMCID: PMC4033321 DOI: 10.3402/iee.v4.24259] [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] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 04/16/2014] [Accepted: 04/24/2014] [Indexed: 11/14/2022] Open
Abstract
Antimicrobial resistance is threatening humans and animals worldwide. Biosecurity and 1-year usage of antibiotics on a dairy concentrated animal feeding operation (CAFO) in NY State, USA, were mapped: how much antibiotics were used, for what purpose, and whether any decrease could be warranted. Approximately 493 kg antibiotics was used, of which 376 kg was ionophores (monensin and lasalocides), 79 kg penicillin, 16.5 kg lincosamides, 8.0 kg aminoglycosides, 7.7 kg sulfamides, 3.4 kg cephalosporin, 2 kg macrolides, 0.7 kg amphenicols, and 0.1 kg fluoroquinolones. Usage reduction by 84% was realistic without compromising the animal welfare. Further reduction could be possible by improving the biosecurity and by utilizing antibiotic sensitivity testing.
Collapse
Affiliation(s)
- Marie Doane
- Faculty of Health and Life Sciences, Department of Biology and Environmental Science, Linnaeus University, Kalmar, Sweden
| | - Sirkku Sarenbo
- Faculty of Health and Life Sciences, Department of Biology and Environmental Science, Linnaeus University, Kalmar, Sweden
| |
Collapse
|
33
|
Chimerel C, Murray AJ, Oldewurtel ER, Summers DK, Keyser UF. The effect of bacterial signal indole on the electrical properties of lipid membranes. Chemphyschem 2013; 14:417-23. [PMID: 23303560 PMCID: PMC3790958 DOI: 10.1002/cphc.201200793] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 11/12/2012] [Accepted: 11/12/2012] [Indexed: 11/06/2022]
Abstract
Indole is an important biological signalling molecule produced by many Gram positive and Gram negative bacterial species, including Escherichia coli. Here we study the effect of indole on the electrical properties of lipid membranes. Using electrophysiology, we show that two indole molecules act cooperatively to transport charge across the hydrophobic core of the lipid membrane. To enhance charge transport, induced by indole across the lipid membrane, we use an indole derivative, 4 fluoro-indole. We demonstrate parallels between charge transport through artificial lipid membranes and the function of complex eukaryotic membrane systems by showing that physiological indole concentrations increase the rate of mitochondrial oxygen consumption. Our data provide a biophysical explanation for how indole may link the metabolism of bacterial and eukaryotic cells.
Collapse
Affiliation(s)
- Catalin Chimerel
- Cavendish Laboratory, Department of PhysicsUniversity of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE (United Kingdom), Fax: (+44) (0)1223 337000
| | - Andrew J Murray
- Department of Physiology, Development & NeuroscienceUniversity of Cambridge, Downing Street, Cambridge, CB2 3EG (United Kingdom)
| | - Enno R Oldewurtel
- Cavendish Laboratory, Department of PhysicsUniversity of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE (United Kingdom), Fax: (+44) (0)1223 337000
| | - David K Summers
- Department of GeneticsUniversity of Cambridge, Downing Street, Cambridge, CB2 3EH (United Kingdom)
| | - Ulrich F Keyser
- Cavendish Laboratory, Department of PhysicsUniversity of Cambridge, JJ Thomson Avenue, Cambridge, CB3 0HE (United Kingdom), Fax: (+44) (0)1223 337000
| |
Collapse
|
34
|
Zahr R, Saeed D, Fumoto H, Horai T, Shalli S, Anzai T, Arakawa Y, Dessoffy R, Catanese J, Massiello A, Litwak KN, Fukamachi K. A pilot study for inducing chronic heart failure in calves by means of oral monensin. Int J Biomed Sci 2010; 6:1-7. [PMID: 23675169 PMCID: PMC3614725] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Accepted: 08/13/2009] [Indexed: 12/03/2022]
Abstract
INTRODUCTION Heart failure remains a major cause of mortality in the United States, despite advancing technologies, newer methods of treatment, and novel devices. To evaluate such novel devices, a large-animal model of chronic heart failure is critical in carrying out preclinical animal studies. METHODS We evaluated the efficacy of oral monensin in inducing stable heart failure in five Jersey calves. Various doses of monensin were administered. Hemodynamics, pressure-volume loops, echocardiographic measurements, extent of tissue perfusion, and histopathologic data were recorded before and after induction of heart failure. RESULTS Responses were variable in the animals. One experiment showed a significant decrease in cardiac output within one week, associated with simultaneous increases in left atrial pressure, central venous pressure, and mean pulmonary artery pressure. Left ventricular pressure-volume loops showed that the slope of the end-systolic pressure-volume relation decreased markedly between the baseline and terminal study, suggesting a decrease in contractility. Echocardiographic studies indicated a decrease in ejection fraction. Histopathologic analysis in cardiac tissue showed extensive fibrosis and necrosis. CONCLUSION We demonstrated the feasibility of inducing and maintaining severe yet stable heart failure for up to 3 weeks in a calf model by administration of oral monensin.
Collapse
Affiliation(s)
- Roula Zahr
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA;
| | - Diyar Saeed
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA;
| | - Hideyuki Fumoto
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA;
| | - Tetsuya Horai
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA;
| | - Shanaz Shalli
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA;
| | - Tomohiro Anzai
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA;
| | - Yoko Arakawa
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA;
| | - Raymond Dessoffy
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA;
| | - Jacquelyn Catanese
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA;
| | - Alex Massiello
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA;
| | | | - Kiyotaka Fukamachi
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA;
| |
Collapse
|
35
|
Vlascici D, Fagadar-Cosma E, Pica EM, Cosma V, Bizerea O, Mihailescu G, Olenic L. Free Base Porphyrins as Ionophores for Heavy Metal Sensors. Sensors (Basel) 2008; 8:4995-5004. [PMID: 27873797 PMCID: PMC3705483 DOI: 10.3390/s8084995] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [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: 07/25/2008] [Revised: 08/13/2008] [Accepted: 08/21/2008] [Indexed: 11/16/2022]
Abstract
Two functionalized porphyrins: 5,10,15,20-tetrakis(3,4-dimethoxyphenyl) porphyrin (A) and 5,10,15,20-tetrakis(3-hydroxyphenyl)porphyrin (B) obtained and characterized by us were used as ionophores (I) for preparing PVC-based membrane sensors selective to Ag⁺, Pb2+ and Cu2+. The membranes were prepared using three different plasticizers: (bis(2-ethylhexyl)sebacate (DOS), dioctylphtalate (DOP), o-nitrophenyl octyl ether (NPOE) and potassium tetrakis(4-chlorophenyl)borate (KTClPB) as additive. The functional parameters (linear concentration range, slope and selectivity) of the sensors with membrane composition: (I:PVC:KTClPB:Plasticizer) in different ratios were investigated. The best results were obtained for the membranes in the ratio I:PVC:KTClPB:Plasticizer 10:165:5:330. The influence of pH on the sensors response was studied. The sensors were used for a period of four months and their utility has been tested on synthetic and real samples.
Collapse
Affiliation(s)
- Dana Vlascici
- West University of Timisoara, 4 V. Parvan Ave, Timisoara 300223 Timis, Romania.
| | - Eugenia Fagadar-Cosma
- Institute of Chemistry -Timişoara of Romanian Academy, 24 M. Viteazul Ave, 300223-Timisoara, Romania.
| | - Elena Maria Pica
- Technical University of Cluj-Napoca, Faculty of Science and Materials Engineering, 15 Constantin Daicoviciu Street, 400020 Cluj-Napoca, Romania.
| | - Viorica Cosma
- Technical University of Cluj-Napoca, Faculty of Science and Materials Engineering, 15 Constantin Daicoviciu Street, 400020 Cluj-Napoca, Romania.
| | - Otilia Bizerea
- West University of Timisoara, 4 V. Parvan Ave, Timisoara 300223 Timis, Romania.
| | - Gheorghe Mihailescu
- Nationale Institute of Research and Development for Isotopic and Molecular Technologies, 71-103 Donath Street 400293, Cluj-Napoca, Romania.
| | - Liliana Olenic
- Nationale Institute of Research and Development for Isotopic and Molecular Technologies, 71-103 Donath Street 400293, Cluj-Napoca, Romania.
| |
Collapse
|
36
|
Hamidinia SA, Erdahl WL, Chapman CJ, Steinbaugh GE, Taylor RW, Pfeiffer DR. Monensin improves the effectiveness of meso-dimercaptosuccinate when used to treat lead intoxication in rats. Environ Health Perspect 2006; 114:484-93. [PMID: 16581534 PMCID: PMC1440769 DOI: 10.1289/ehp.8279] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Among divalent cations, the ionophore monensin shows high activity and selectivity for the transport of lead ions (Pb2+) across phospholipid membranes. When coadministered to rats that were receiving meso-dimercaptosuccinate for treatment of Pb intoxication, monensin significantly increased the amount of Pb removed from femur, brain, and heart. It showed a tendency to increase Pb removal from liver and kidney but had no effect of this type in skeletal muscle. Tissue levels of several physiologic (calcium, cobalt, copper, iron, magnesium, manganese, molybdenum, zinc) and nonphysiologic (arsenic, cadmium, chromium, nickel, strontium) elements were also determined after the application of these compounds. Among the physiologic elements, a number of significant changes were seen, including both rising and falling values. The size of these changes was typically around 20% compared with control values, with the largest examples seen in femur. These changes often tended to reverse those of similar size that had occurred during Pb administration. Among the nonphysiologic elements, which were present in trace amounts, the changes were smaller in number but larger in size. None of these changes appears likely to be significant in terms of toxicity, and there were no signs of overt toxicity under any of the conditions employed. Monensin may act by cotransporting Pb2+ and OH- ions out of cells, in exchange for external sodium ions. The net effect would be to shuttle intracellular Pb2+ to extracellular dimercaptosuccinic acid thereby enhancing its effectiveness. Thus, monensin may be useful for the treatment of Pb intoxication when applied in combination with hydrophilic Pb2+ chelators.
Collapse
Affiliation(s)
- Shawn A Hamidinia
- Departments of Molecular and Cellular Biochemistry, Ohio State University, Columbus, Ohio, USA
| | | | | | | | | | | |
Collapse
|
37
|
Nishino H, Schiller RM, Parnes JR, Isselbacher KJ. Role of Na+ in alpha-aminoisobutyric acid uptake by membrane vesicles from mouse fibroblasts transformed by simian virus 40. Proc Natl Acad Sci U S A 1978; 75:2329-32. [PMID: 79182 PMCID: PMC392546 DOI: 10.1073/pnas.75.5.2329] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The uptake of alpha-amino[(3)H]isobutyric acid (AIB) was studied in membrane vesicles from mouse fibroblasts transformed by simian virus 40 to examine the features of the Na(+)-stimulated and Na(+)-dependent AIB transport process. The simultaneous addition of NaCl and AIB to these vesicles produced a transient accumulation, or "overshoot," of amino acid 3-4 times the equilibrium value. Both the initial rate of uptake and the rate of fall of intravesicular AIB after maximal accumulation were sensitive to the temperature of incubation. The overshoot of AIB uptake was enhanced with Na(+) salts of highly permeant lipophilic anions, such as SCN(-) and NO(3) (-), and was decreased by the addition of SO(4) (2-), a relatively impermeant ion. Gramicidin D, which enhances the membrane conductance of Na(+) electrogenically, decreased the overshoot, while a potassium diffusion potential, induced by valinomycin (in K(+)-preloaded membrane vesicles), produced a Na(+)-dependent overshoot of AIB uptake. When vesicles were preincubated with both Na(+) and AIB, followed by the generation of an interior negative membrane potential (by the addition of SCN(-)), an overshoot of AIB uptake resulted. However, this did not occur in the absence of Na(+). It is concluded that, apart from its role in the generation of a transmembrane electrochemical potential, Na(+) is essential for the overshoot of AIB uptake.
Collapse
|
38
|
Hirata H, Altendorf K, Harold FM. Role of an electrical potential in the coupling of metabolic energy to active transport by membrane vesicles of Escherichia coli. Proc Natl Acad Sci U S A 1973; 70:1804-8. [PMID: 4578444 PMCID: PMC433601 DOI: 10.1073/pnas.70.6.1804] [Citation(s) in RCA: 152] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Membrane vesicles from E. coli can oxidize D-lactate and other substrates and couple respiration to the active transport of sugars and amino acids. The present experiments bear on the nature of the link between respiration and transport. Respiring vesicles were found to accumulate dibenzyldimethylammonium ion, a synthetic lipid-soluble cation that serves as an indicator of an electrical potential. The results suggest that oxidation of D-lactate generates a membrane potential, vesicle interior negative, of the order of -100 mV. In vesicles lacking substrate, an electrical potential was created by induction of electrogenic efflux of K(+) with the aid of the K(+) ionophores, valinomycin and monactin. These conditions induced transient accumulation by the vesicles of [(14)C]proline and other metabolites. Experiments with inhibitors and ionophores indicate that neither ATP nor the respiratory chain is involved; the electrical potential generated by K(+) efflux is coupled directly to the transport systems. The results verify two predictions derived from Mitchell's chemiosmotic hypothesis: respiring vesicles generate an electrical potential of the proper polarity and magnitude; and a membrane potential is in itself sufficient to drive the active transport of amino acids and other metabolites.
Collapse
|