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Macrophage-produced peroxynitrite induces antibiotic tolerance and supersedes intrinsic mechanisms of persister formation. Infect Immun 2021; 89:e0028621. [PMID: 34097475 DOI: 10.1128/iai.00286-21] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Staphylococcus aureus is a leading human pathogen that frequently causes chronic and relapsing infections. Antibiotic tolerant persister cells contribute to frequent antibiotic failure in patients. Macrophages represent an important niche during S. aureus bacteremia and recent work has identified a role for oxidative burst in the formation of antibiotic tolerant S. aureus. We find that host-derived peroxynitrite, the reaction product of superoxide and nitric oxide, is the main mediator of antibiotic tolerance in macrophages. Using a collection of S. aureus clinical isolates, we find that, despite significant variation in persister formation in pure culture, all strains were similarly enriched for antibiotic tolerance following internalization by activated macrophages. Our findings suggest that host interaction strongly induces antibiotic tolerance and may negate bacterial mechanisms of persister formation, established in pure culture. These findings emphasize the importance of studying antibiotic tolerance in the context of bacterial interaction with the host suggest that modulation of the host response may represent a viable therapeutic strategy to sensitize S. aureus to antibiotics.
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Juan CA, Pérez de la Lastra JM, Plou FJ, Pérez-Lebeña E. The Chemistry of Reactive Oxygen Species (ROS) Revisited: Outlining Their Role in Biological Macromolecules (DNA, Lipids and Proteins) and Induced Pathologies. Int J Mol Sci 2021; 22:4642. [PMID: 33924958 PMCID: PMC8125527 DOI: 10.3390/ijms22094642] [Citation(s) in RCA: 631] [Impact Index Per Article: 210.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 04/25/2021] [Accepted: 04/26/2021] [Indexed: 02/08/2023] Open
Abstract
Living species are continuously subjected to all extrinsic forms of reactive oxidants and others that are produced endogenously. There is extensive literature on the generation and effects of reactive oxygen species (ROS) in biological processes, both in terms of alteration and their role in cellular signaling and regulatory pathways. Cells produce ROS as a controlled physiological process, but increasing ROS becomes pathological and leads to oxidative stress and disease. The induction of oxidative stress is an imbalance between the production of radical species and the antioxidant defense systems, which can cause damage to cellular biomolecules, including lipids, proteins and DNA. Cellular and biochemical experiments have been complemented in various ways to explain the biological chemistry of ROS oxidants. However, it is often unclear how this translates into chemical reactions involving redox changes. This review addresses this question and includes a robust mechanistic explanation of the chemical reactions of ROS and oxidative stress.
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Affiliation(s)
- Celia Andrés Juan
- Cinquima Institute and Department of Organic Chemistry, Faculty of Sciences, Valladolid University, Paseo de Belén, 7, 47011 Valladolid, Spain;
| | - José Manuel Pérez de la Lastra
- Institute of Natural Products and Agrobiology, CSIC-Spanish Research Council, Avda. Astrofísico Fco. Sánchez, 38206 La Laguna, Spain
| | - Francisco J. Plou
- Institute of Catalysis and Petrochemistry, CSIC-Spanish Research Council, 28049 Madrid, Spain;
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An electrophysiological evaluation method for the ovine facial nerve. Regen Ther 2021; 18:76-81. [PMID: 33969162 PMCID: PMC8060511 DOI: 10.1016/j.reth.2021.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/12/2021] [Accepted: 03/26/2021] [Indexed: 12/04/2022] Open
Abstract
Introduction Large-animal models such as sheep for facial nerve regeneration research have not yet been established because of the lack of methods for assessing the electrophysiological function of regenerated nerves. In this study, we developed a percutaneous measurement method for the evoked compound muscle action potential (CMAP) of the facial nerve in sheep. Methods Six 3-year-old castrated male Corriedale sheep were used in this study. Under general anesthesia, an anatomical exploration was performed to identify the course of the buccal branch of the facial nerve and its innervating muscles on one side, followed by the application of surface stimulating electrodes to the contralateral side of the face along the course of the buccal branch of the facial nerve to obtain CMAP measurements of the nasolabial levator muscle. Results Percutaneous CMAP measurements of the nasolabial levator muscle could be obtained in all animals by placing stimulating electrodes 1 cm apart on the line coinciding with the course of the buccal branch of the facial nerve revealed by the preceding anatomical exploration. Mean values for electrophysiological parameters were amplitude 4.7 ± 0.7 mV, duration 2.1 ± 0.6 ms, and latency 3.6 ± 0.4 ms. Conclusion We have established a percutaneous measurement method for CMAP of the buccal branch of the facial nerve in sheep. This method is expected to be very useful in future studies of facial nerve regeneration for long nerve defects in sheep. A percutaneous CMAP measurement method for the ovine facial nerve was established. Anatomical experiment demonstrated the method's physiological accuracy. The ovine facial nerve enables a more realistic model of facial nerve regeneration.
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Lopez E, Fukuda S, Modis K, Fujiwara O, Enkhtaivan B, Trujillo-Abarca R, Ihara K, Lima-Lopez F, Perez-Bello D, Szabo C, Prough DS, Enkhbaatar P. Arginine vasopressin receptor 2 activation promotes microvascular permeability in sepsis. Pharmacol Res 2020; 163:105272. [PMID: 33160069 DOI: 10.1016/j.phrs.2020.105272] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 10/23/2020] [Accepted: 10/27/2020] [Indexed: 12/16/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) sepsis is a severe condition associated with vascular leakage and poor prognosis. The hemodynamic management of sepsis targets hypotension, but there is no specific treatment available for vascular leakage. Arginine vasopressin (AVP) has been used in sepsis to promote vasoconstriction by activating AVP receptor 1 (V1R). However, recent evidence suggests that increased fluid retention may be associated with the AVP receptor 2 (V2R) activation worsening the outcome of sepsis. Hence, we hypothesized that the inhibition of V2R activation ameliorates the severity of microvascular hyperpermeability during sepsis. The hypothesis was tested using a well-characterized and clinically relevant ovine model of MRSA pneumonia/sepsis and in vitro assays of human lung microvascular endothelial cells (HMVECs). in vivo experiments demonstrated that the treatment of septic sheep with tolvaptan (TLVP), an FDA-approved V2R antagonist, significantly attenuated the sepsis-induced fluid retention and markedly reduced the lung water content. These pathological changes were not affected by the treatment with V2R agonist, desmopressin (DDAVP). Additionally, the incubation of cultured HMVECs with DDAVP, and DDAVP along with MRSA significantly increased the paracellular permeability. Finally, both the DDAVP and MRSA-induced hyperpermeability was significantly attenuated by TLVP. Subsequent protein and gene expression assays determined that the V2R-induced increase in permeability is mediated by phospholipase C beta (PLCβ) and the potent permeability factor angiopoietin-2. In conclusion, our results indicate that the activation of the AVP-V2R axis is critical in the pathophysiology of severe microvascular hyperpermeability during Gram-positive sepsis. The use of the antagonist TLVP should be considered as adjuvant treatment for septic patients. The results from this clinically relevant animal study are highly translational to clinical practice.
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Affiliation(s)
- Ernesto Lopez
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA
| | - Satoshi Fukuda
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA
| | - Katalin Modis
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA; Department of Surgery, University of Texas Medical Branch Galveston, TX, USA
| | - Osamu Fujiwara
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA
| | - Baigal Enkhtaivan
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA
| | - Raul Trujillo-Abarca
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA
| | - Koji Ihara
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA; Department of Plastic and Reconstructive Surgery, Kagoshima City Hospital, Kagoshima, Japan
| | - Francisco Lima-Lopez
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA; Department of Surgery, University of Texas Medical Branch Galveston, TX, USA
| | - Dannelys Perez-Bello
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA
| | - Csaba Szabo
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA; Department of Pharmacology, University of Fribourg, Fribourg, Switzerland
| | - Donald S Prough
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA
| | - Perenlei Enkhbaatar
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA.
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