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Di Bonaventura G, Lupetti V, Pompilio A. Impact of Growth Conditions on High-Throughput Identification of Repurposing Drugs for Pseudomonas aeruginosa Cystic Fibrosis Lung Infections. Antibiotics (Basel) 2024; 13:642. [PMID: 39061324 PMCID: PMC11273527 DOI: 10.3390/antibiotics13070642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2024] [Revised: 06/26/2024] [Accepted: 07/10/2024] [Indexed: 07/28/2024] Open
Abstract
Pseudomonas aeruginosa lung infections in cystic fibrosis (CF) patients represent a therapeutic challenge due to antibiotic resistance. Repurposing existing drugs is a promising approach for identifying new antimicrobials. A crucial factor in successful drug repurposing is using assay conditions that mirror the site of infection. Here, the impact of growth conditions on the anti-P. aeruginosa activity of a library of 3386 compounds was evaluated. To this, after 24 h exposure, the survival rate of CF P. aeruginosa RP73 planktonic cells was assessed spectrophotometrically under "CF-like" (artificial CF sputum, pH 6.8, 5% CO2) and enriched (Tryptone Soya Broth, pH 7.2, and aerobiosis) conditions. Among non-antibiotic compounds (n = 3127), 13.4% were active regardless of growth conditions, although only 3.2% had comparable activity; 4% and 6.2% were more active under CF-like or enriched conditions, respectively. Interestingly, 22.1% and 26.6% were active exclusively under CF-like and enriched conditions, respectively. Notably, 7 and 12 hits caused 100% killing under CF-like and enriched conditions, respectively. Among antibiotics (n = 234), 42.3% were active under both conditions, although only 18.4% showed comparable activity; 9.4% and 14.5% were more active under CF-like and enriched conditions, respectively. Interestingly, 23% and 16.6% were active exclusively under CF-like and enriched conditions, respectively. Sulphonamides showed higher activity under CF-like conditions, whereas tetracyclines, fluoroquinolones, and macrolides were more effective under enriched settings. Our findings indicated that growth conditions significantly affect the anti-P. aeruginosa activity of antibiotics and non-antibiotic drugs. Consequently, repurposing studies and susceptibility tests should be performed under physicochemical conditions that the pathogen tackles at the site of infection.
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Affiliation(s)
- Giovanni Di Bonaventura
- Department of Medical, Oral and Biotechnological Sciences, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (V.L.); (A.P.)
- Center for Advanced Studies and Technology, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy
| | - Veronica Lupetti
- Department of Medical, Oral and Biotechnological Sciences, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (V.L.); (A.P.)
- Center for Advanced Studies and Technology, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy
| | - Arianna Pompilio
- Department of Medical, Oral and Biotechnological Sciences, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy; (V.L.); (A.P.)
- Center for Advanced Studies and Technology, “G. d’Annunzio” University of Chieti-Pescara, 66100 Chieti, Italy
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Oronsky B, Takahashi L, Gordon R, Cabrales P, Caroen S, Reid T. RRx-001: a chimeric triple action NLRP3 inhibitor, Nrf2 inducer, and nitric oxide superagonist. Front Oncol 2023; 13:1204143. [PMID: 37313460 PMCID: PMC10258348 DOI: 10.3389/fonc.2023.1204143] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 05/18/2023] [Indexed: 06/15/2023] Open
Abstract
RRx-001 is a shape shifting small molecule with Fast Track designation for the prevention/amelioration of chemoradiation-induced severe oral mucositis (SOM) in newly diagnosed Head and Neck cancer. It has been intentionally developed or "engineered" as a chimeric single molecular entity that targets multiple redox-based mechanisms. Like an antibody drug conjugate (ADC), RRx-001 contains, at one end a "targeting" moiety, which binds to the NLRP3 inflammasome and inhibits it as well as Kelch-like ECH-associated protein 1 (KEAP1), the negative regulator of Nrf2, and, at the other end, a conformationally constrained, dinitro containing 4 membered ring, which fragments under conditions of hypoxia and reduction to release therapeutically active metabolites i.e., the payload. This "payload", which is delivered specifically to hypoperfused and inflamed areas, includes nitric oxide, nitric oxide related species and carbon-centered radicals. As observed with ADCs, RRx-001 contains a backbone amide "linker" attached to a binding site, which correlates with the Fab region of an antibody, and to the dinitroazetidine payload, which is microenvironmentally activated. However, unlike ADCs, whose large size impacts their pharmacokinetic properties, RRx-001 is a nonpolar small molecule that easily crosses cell membranes and the blood brain barrier (BBB) and distributes systemically. This short review is organized around the de novo design and in vivo pro-oxidant/pro-inflammatory and antioxidant/anti-inflammatory activity of RRx-001, which, in turn, depends on the reduced to oxidized glutathione ratio and the oxygenation status of tissues.
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Affiliation(s)
- Bryan Oronsky
- Drug Development, EpicentRx, Torrey Pines, CA, United States
| | - Lori Takahashi
- Drug Development, EpicentRx, Torrey Pines, CA, United States
| | - Richard Gordon
- Department of Translational Neuroscience, University of Queensland Centre for Clinical Research, Brisbane, QLD, Australia
| | - Pedro Cabrales
- Department of Bioengineering, University of California at San Diego, La Jolla, CA, United States
| | - Scott Caroen
- Drug Development, EpicentRx, Torrey Pines, CA, United States
| | - Tony Reid
- Drug Development, EpicentRx, Torrey Pines, CA, United States
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A Review of RRx-001: A Late-Stage Multi-Indication Inhibitor of NLRP3 Activation and Chronic Inflammation. Drugs 2023; 83:389-402. [PMID: 36920652 PMCID: PMC10015535 DOI: 10.1007/s40265-023-01838-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/22/2023] [Indexed: 03/16/2023]
Abstract
Chronic unresolving inflammation is emerging as a key underlying pathological feature of many if not most diseases ranging from autoimmune conditions to cardiometabolic and neurological disorders. Dysregulated immune and inflammasome activation is thought to be the central driver of unresolving inflammation, which in some ways provides a unified theory of disease pathology and progression. Inflammasomes are a group of large cytosolic protein complexes that, in response to infection- or stress-associated stimuli, oligomerize and assemble to generate a platform for driving inflammation. This occurs through proteolytic activation of caspase-1-mediated inflammatory responses, including cleavage and secretion of the proinflammatory cytokines interleukin (IL)-1β and IL-18, and initiation of pyroptosis, an inflammatory form of cell death. Several inflammasomes have been characterized. The most well-studied is the nucleotide-binding domain (NOD)-like receptor protein 3 (NLRP3) inflammasome, so named because the NLRP3 protein in the complex, which is primarily present in immune and inflammatory cells following activation by inflammatory stimuli, belongs to the family of nucleotide-binding and oligomerization domain (Nod) receptor proteins. Several NLRP3 inflammasome inhibitors are in development, all with multi-indication activity. This review discusses the current status, known mechanisms of action, and disease-modifying therapeutic potential of RRx-001, a direct NLRP3 inflammasome inhibitor under investigation in several late-stage anticancer clinical trials, including a phase 3 trial for the treatment of third-line and beyond small cell lung cancer (SCLC), an indication with no treatment, in which RRx-001 is combined with reintroduced chemotherapy from the first line, carboplatin/cisplatin and etoposide (ClinicalTrials.gov Identifier: NCT03699956). Studies from multiple independent groups have now confirmed that RRx-001 is safe and well tolerated in humans. Additionally, emerging evidence in preclinical animal models suggests that RRx-001 could be effective in a wide range of diseases where immune and inflammasome activation drives disease pathology.
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Hammond TC, Lee RC, Oronsky B, Reid TR, Caroen S, Juarez TM, Gill J, Heng A, Kesari S. Clinical Course of Two Patients with COVID-19 Respiratory Failure After Administration of the Anticancer Small Molecule, RRx-001. Int Med Case Rep J 2022; 15:735-738. [PMID: 36545548 PMCID: PMC9762260 DOI: 10.2147/imcrj.s389690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Two critically ill COVID-19 infected patients, who had exhausted all available treatment options, were treated with the small-molecule RRx-001 with subsequent improvement. RRx-001, a first-in-class small molecule with anti-inflammatory, vascular normalizing and macrophage-repolarizing properties, has been safely administered 300+ patients in clinical trials. This is the first report of RRx-001 treatment of COVID-19.
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Affiliation(s)
- Terese Catherine Hammond
- Providence St. Johns Health Center, Santa Monica, CA, USA,John Wayne Cancer Institute, Santa Monica, CA, USA
| | - Raymond C Lee
- Providence St. Johns Health Center, Santa Monica, CA, USA,Cardiovascular Thoracic Institute, Keck School of Medicine of USC, Los Angeles, CA, USA
| | - Bryan Oronsky
- EpicentRx, Inc., La Jolla, CA, USA,Correspondence: Bryan Oronsky, EpicentRx, Inc, 11099 North Torrey Pines Road, La Jolla, CA, 92037, USA, Tel +1 858 947-6635, Fax +1 858 724-3080, Email
| | | | | | | | - Jaya Gill
- Pacific Neuroscience Institute, Santa Monica, CA, USA
| | - Annie Heng
- John Wayne Cancer Institute, Santa Monica, CA, USA
| | - Santosh Kesari
- Providence St. Johns Health Center, Santa Monica, CA, USA,John Wayne Cancer Institute, Santa Monica, CA, USA,Pacific Neuroscience Institute, Santa Monica, CA, USA
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Oronsky B, Caroen S, Abrouk N, Reid TR. RRx-001 and the "Right stuff": Protection and treatment in outer space. LIFE SCIENCES IN SPACE RESEARCH 2022; 35:69-75. [PMID: 36336372 DOI: 10.1016/j.lssr.2022.05.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 04/26/2022] [Accepted: 05/09/2022] [Indexed: 06/16/2023]
Abstract
From antibiotics to aspirin to antimalarials and to anticancer agents, about half of the world's best-selling drugs are derived from nature. However, accelerating climatic disruption, habitat destruction, pollution, and biodiversity loss all negatively impact the potential of natural sources to continue to serve as repositories of novel pharmaceuticals. On that basis, the final frontier for drug development is perhaps not the rainforests, coral reefs, and other natural habitats but rather the aerospace industry with its virtually unlimited and inexhaustible man-made 'library' of potentially bioactive compounds. The first aerospace-sourced therapeutic to reach the clinic is RRx-001, an inhibitor of the NOD-like receptor - Nucleotide-binding oligomerization domain with Leucine rich Repeat and Pyrin domain (NLRP3) inflammasome in a Phase 3 trial for the treatment of small cell lung cancer (SCLC) and in a soon-to-start Phase 3 trial for protection against chemoradiotherapy-induced severe oral mucositis in first line head and neck cancer. As manned missions to the Moon, Mars, and asteroids as well as space tourism beckon, it is perhaps fitting that a compound like RRx-001, which is derived from 1,3,3-Trinitroazetidine (TNAZ), an explosive propellant for rockets, is a potential "all purpose" option to mitigate the major biomedical effects of space radiation exposures including cancer development and other tissue degenerations both within mission and after mission. This article highlights the promise of RRx-001 to attenuate the acute and late effects of radiation exposure on astronauts including the development of cancer.
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Fang J, She J, Lin F, Wu JC, Han R, Sheng R, Wang G, Qin ZH. RRx-001 Exerts Neuroprotection Against LPS-Induced Microglia Activation and Neuroinflammation Through Disturbing the TLR4 Pathway. Front Pharmacol 2022; 13:889383. [PMID: 35462935 PMCID: PMC9020799 DOI: 10.3389/fphar.2022.889383] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 03/22/2022] [Indexed: 12/17/2022] Open
Abstract
Neuroinflammation plays an important role in the pathogenesis of many central nervous system diseases. Here, we investigated the effect of an anti-cancer compound RRx-001 on neuroinflammation and its possible new applications. BV2 cells and primary microglia cells were used to evaluate the role of RRx-001 in LPS-induced microglial activation and inflammatory response in vitro. And, we found that the increase in the synthesis and release of cytokines and the up-regulation of pro-inflammatory factors in LPS-treated microglial cells were significantly reduced by RRx-001 pretreatment. As the most classical inflammatory pathways, NF-κB and MAPK signaling pathways were activated by LPS, but were inhibited by RRx-001. Transcription of NLRP3 was also reduced by RRx-001. In addition, LPS induced oxidative stress by increasing the expression of Nox mediated by transcription factors NF-κB and AP-1, while RRx-001 pretreatment ameliorated Nox-mediated oxidative stress. LPS-induced activation of TAK1, an upstream regulator of NF-κB and MAPK pathways, was significantly inhibited by RRx-001 pretreatment, whereas recruitment of MyD88 to TLR4 was not affected by RRx-001. LPS-primed BV2 condition medium induced injury of primary neurons, and this effect was inhibited by RRx-001. Furthermore, we established a neuroinflammatory mouse model by stereotactic injection of LPS into the substantia nigra pars compacta (SNpc), and RRx-001 dose-dependently reduced LPS-induced microglial activation and loss of TH + neurons in the midbrain. In conclusion, the current study found that RRx-001 suppressed microglia activation and neuroinflammation through targeting TAK1, and may be a candidate for the treatment of neuroinflammation-related brain diseases.
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Affiliation(s)
- Jie Fang
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Jing She
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Fang Lin
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Jun-Chao Wu
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Rong Han
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Rui Sheng
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Guanghui Wang
- Department of Pharmacology and Laboratory of Molecular Pathology, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences, Soochow University, Suzhou, China
| | - Zheng-Hong Qin
- Department of Pharmacology and Laboratory of Aging and Nervous Diseases, Jiangsu Key Laboratory of Neuropsychiatric Diseases, College of Pharmaceutical Sciences, Soochow University, Suzhou, China
- *Correspondence: Zheng-Hong Qin,
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Bath PM, Coleman CM, Gordon AL, Lim WS, Webb AJ. Nitric oxide for the prevention and treatment of viral, bacterial, protozoal and fungal infections. F1000Res 2021; 10:536. [PMID: 35685687 PMCID: PMC9171293 DOI: 10.12688/f1000research.51270.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/15/2021] [Indexed: 12/18/2023] Open
Abstract
Although the antimicrobial potential of nitric oxide (NO) is widely published, it is little used clinically. NO is a key signalling molecule modulating vascular, neuronal, inflammatory and immune responses. Endogenous antimicrobial activity is largely mediated by high local NO concentrations produced by cellular inducible nitric oxide synthase, and by derivative reactive nitrogen oxide species including peroxynitrite and S-nitrosothiols. NO may be taken as dietary substrate (inorganic nitrate, L-arginine), and therapeutically as gaseous NO, and transdermal, sublingual, oral, intranasal and intravenous nitrite or nitrate. Numerous preclinical studies have demonstrated that NO has generic static and cidal activities against viruses (including β-coronaviruses such as SARS-CoV-2), bacteria, protozoa and fungi/yeasts in vitro. Therapeutic effects have been seen in animal models in vivo, and phase II trials have demonstrated that NO donors can reduce microbial infection. Nevertheless, excess NO, as occurs in septic shock, is associated with increased morbidity and mortality. In view of the dose-dependent positive and negative effects of NO, safety and efficacy trials of NO and its donors are needed for assessing their role in the prevention and treatment of infections. Trials should test dietary inorganic nitrate for pre- or post-exposure prophylaxis and gaseous NO or oral, topical or intravenous nitrite and nitrate for treatment of mild-to-severe infections, including due to SARS-CoV-2 (COVID-19). This review summarises the evidence base from in vitro, in vivo and early phase clinical studies of NO activity in viral, bacterial, protozoal and fungal infections.
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Affiliation(s)
- Philip M. Bath
- Stroke Trials Unit, Division of Clinical Neuroscience, University of Nottingham, Nottingham, Notts, NG7 2UH, UK
- Stroke, Nottingham University Hospitals NHS Trust, Nottingham, Notts, NG7 2UH, UK
| | - Christopher M. Coleman
- Division of Infection, Immunity and Microbes, School of Life Sciences, University of Nottingham, Nottingham, Notts, NG7 2UH, UK
| | - Adam L. Gordon
- Unit of Injury, Inflammation and Recovery Sciences, University of Nottingham, Derby, Derbyshire, DE22 3NE, UK
- NIHR Applied Research Collaboration-East Midlands (ARC-EM), Nottingham, Notts, UK
| | - Wei Shen Lim
- Respiratory Medicine, Nottingham University Hospitals NHS Trust, Nottingham, NG5 1PB, UK
| | - Andrew J. Webb
- Clinical Pharmacology, School of Cardiovascular Medicine & Sciences, Kings College London British Heart Foundation Centre of Research Excellence, St Thomas' Hospital, London, SE1 7EH, UK
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Oronsky B, Knox S, Cabrales P, Oronsky A, Reid TR. Desperate Times, Desperate Measures: The Case for RRx-001 in the Treatment of COVID-19. Semin Oncol 2020; 47:305-308. [PMID: 32718560 PMCID: PMC7341953 DOI: 10.1053/j.seminoncol.2020.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 06/23/2020] [Accepted: 07/01/2020] [Indexed: 01/10/2023]
Abstract
This article summarizes the likely attenuation properties of RRx-001 in COVID-19 based on its mechanism of action and the putative pathogenesis of the disease, which appears to activate inflammatory, oxidative, and immune cascades with the potential to culminate in acute respiratory distress syndrome, cytokine storm and death. An ongoing pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), COVID-19 appears to present with 3 major patterns of clinical symptomatology: (1) mild upper respiratory tract infection, (2) non–life-threatening pneumonia, and (3) severe pneumonia and acute respiratory distress syndrome that initially manifest as a mild prodrome lasting for 7–8 days before rapid clinical and radiological deterioration requiring ICU transfer. RRx-001 is a targeted nitric oxide donor. This small molecule, which has been evaluated in multiple Phase 1–2 clinical trials for cancer as well as a Phase 3 clinical trial for the treatment of small cell lung cancer called REPLATINUM (NCT03699956), is minimally toxic and demonstrates clear evidence of antitumor activity. During the course of these clinical trials it was noted that the rate of chronic obstructive pulmonary disease exacerbation and pneumonia in actively smoking small cell lung cancer patients treated with RRx-001 is less than 1%. Due to extensive history of tobacco use, 40%–70% of patients with lung cancer have chronic obstructive pulmonary disease and the expected rate of pulmonary infection in this population is 50%–70%, which was not observed in RRx-001 clinical trials. Moreover, in preclinical studies of pulmonary hypertension, RRx-001 was found to be comparable with or more effective than the FDA approved agent, Bosentan. The potential pulmonary protective effects of RRx-001 in patients with recurrent lung infections coupled with preclinical models demonstrating RRx-001-mediated reversal of pulmonary hypertension suggests RRx-001 may have therapeutic activity in patients with acute respiratory symptoms due to COVID 19. Clinical trials have been initiated to confirm the hypothesis that RRx-001 may be repurposed to treat SARS-CoV-2 infection.
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Cirrik S, Ugurel E, Aksu AC, Oronsky B, Cabrales P, Yalcin O. Nitrite may serve as a combination partner and a biomarker for the anti-cancer activity of RRx-001. Biorheology 2019; 56:221-235. [DOI: 10.3233/bir-190213] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
| | - Elif Ugurel
- Koc University School of Medicine, , , Turkey
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Jani VP, Yalcin O, Williams AT, Popovsky MA, Cabrales P. Rat red blood cell storage lesions in various additive solutions. Clin Hemorheol Microcirc 2018; 67:45-57. [PMID: 28598831 DOI: 10.3233/ch-170248] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Small rodent models are routinely used to evaluate the safety and efficacy of blood transfusions. Limited comprehensive literature exists about effect of different storage solutions in rat red blood cells (RBCs) characteristics. RBCs undergo time dependent biochemical and biophysical changes during storage known as hypothermic storage lesions (HSLs). OBJECTIVE This study evaluates the effects of RBC additive solutions (AS) during storage of rat RBCs. METHODS Blood was leukoreduced and stored as per manufacturer instructions at 4°C up to 42-days. Three solutions, CPDA-1; AS-1; and AS-7 (SOLX), were evaluated. Biochemical parameters measured included extracellular K+, pH, hemolysis, 2,3-diphosphoglycerate (2,3-DPG), oxygen affinity, ATP, and lactate. Mechanical properties measured included RBC deformability, elongation index (EI), RBC membrane shear elastic modulus (SEM), mean corpuscular volume (MCV), viscosity, and aggregability. RESULTS There were no differences in biochemical or mechanical parameters at baseline or after one week of storage. However, after two weeks, AS-7 preserved biochemical and mechanical properties as compared to CPDA-1 and AS-1. Changes were observed to be significant after 14-days of storage. AS-7 prevented extracellular K+ increase, reduced acidosis, showed lower hemolysis, preserved ATP and 2,3-DPG levels (consequently oxygen affinity), and reduced lactate. AS-7, when compared to CPDA-1 and AS-1, prevented the reduction in RBC deformability and was found to preserve the EI at multiple shear stresses, the membrane SEM, the aggregability and viscosity. DISCUSSION Rat RBCs stored with AS-7 presented reduced changes in biochemical and mechanical parameters, when compared with rat RBCs stored in CPDA-1 and AS-1, after as early as two weeks of storage.
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Affiliation(s)
- Vivek P Jani
- Department of Bioengineering, University of California, San Diego, CA, USA
| | - Ozlem Yalcin
- Department of Bioengineering, University of California, San Diego, CA, USA.,School of Medicine, Koç University, Sariyer, Istanbul, Turkey
| | | | | | - Pedro Cabrales
- Department of Bioengineering, University of California, San Diego, CA, USA
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Fallatah O, Georges E. Apigenin-induced ABCC1-mediated efflux of glutathione from mature erythrocytes inhibits the proliferation of Plasmodium falciparum. Int J Antimicrob Agents 2017; 50:673-677. [DOI: 10.1016/j.ijantimicag.2017.08.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 08/03/2017] [Accepted: 08/05/2017] [Indexed: 01/28/2023]
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Cabrales P, Caroen S, Oronsky A, Carter C, Trepel J, Summers T, Reid T, Oronsky N, Lybeck M, Oronsky B. The macrophage stimulating anti-cancer agent, RRx-001, protects against ischemia-reperfusion injury. Expert Rev Hematol 2017; 10:575-582. [PMID: 28448172 DOI: 10.1080/17474086.2017.1324779] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND RRx-001, a clinical macrophage-stimulating anti-cancer agent that also produces nitric oxide (NO) was studied in a model of ischemia-reperfusion injury. METHODS The production of NO is dependent on the oxygen tension because nitric oxide synthases convert l-arginine to NO and l-citrulline in the presence of O2. Since the P450 enzymes, which metabolize nitrate esters such as nitroglycerin are dependent on oxygen, the generation of 'exogenous' NO is also sensitive to alterations in tissue PO2. I/R injury was studied in a hamster chamber window, with compression of the periphery of the window for 1 h to induce ischemia. Animals received RRx-001 (5 mg/kg) 24 h before ischemia and sodium nitrite (10 nmols/kg) was supplemented 10 min after the start of reperfusion. Vessel diameter, blood flow, adherent leukocytes, and functional capillary density were assessed by intravital microscopy at 0.5, 2, and 24 h following the release of the ischemia. RESULTS The results demonstrated that, compared to control, RRx-001 preconditioning increased blood flow and functional capillary density, and preserved tissue viability in the absence of side effects over a sustained time period. CONCLUSION Thus, RRx-001 may serve as a long-lived protective agent during postsurgical restoration of flow and other ischemia-reperfusion associated conditions, increasing blood flow and functional capillary density as well as preserving tissue viability in the absence of side effects.
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Affiliation(s)
- Pedro Cabrales
- a Department of Bioengineering , University of California San Diego (UCSD) , La Jolla , CA , USA
| | | | | | - Corey Carter
- d Walter Reed Military Medical Center , Murtha Cancer Center , Bethesda , MD , USA
| | - Jane Trepel
- e Moores Cancer Center , University of California San Diego (UCSD) , La Jolla , CA , USA
| | - Thomas Summers
- d Walter Reed Military Medical Center , Murtha Cancer Center , Bethesda , MD , USA
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Oronsky B, Paulmurugan R, Foygel K, Scicinski J, Knox SJ, Peehl D, Zhao H, Ning S, Cabrales P, Summers TA, Reid TR, Fitch WL, Kim MM, Trepel JB, Lee MJ, Kesari S, Abrouk ND, Day RM, Oronsky A, Ray CM, Carter CA. RRx-001: a systemically non-toxic M2-to-M1 macrophage stimulating and prosensitizing agent in Phase II clinical trials. Expert Opin Investig Drugs 2017; 26:109-119. [PMID: 27935336 DOI: 10.1080/13543784.2017.1268600] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
INTRODUCTION According to Hanahan and Weinberg, cancer manifests as six essential physiologic hallmarks: (1) self-sufficiency in growth signals, (2) insensitivity to growth-inhibitory signals, (3) evasion of programmed cell death, (4) limitless replicative potential, (5) sustained angiogenesis, and (6) invasion and metastasis. As a facilitator of these traits as well as immunosuppression and chemoresistance, the presence of tumor-associated macrophages (TAMs) may serve as the seventh hallmark of cancer. Anticancer agents that successfully reprogram TAMs to target rather than support tumor cells may hold the key to better therapeutic outcomes. Areas covered: This article summarizes the characteristics of the macrophage-stimulating agent RRx-001, a molecular iconoclast, sourced from the aerospace industry, with a particular emphasis on the cell-to-cell transfer mechanism of action (RBCs to TAMs) underlying its antitumor activity as well as its chemo and radioprotective properties, consolidated from various preclinical and clinical studies. Expert opinion: RRx-001 is macrophage-stimulating agent with the potential to synergize with chemotherapy, radiotherapy and immunotherapy while simultaneously protecting normal tissues from their cytotoxic effects. Given the promising indications of activity in multiple tumor types and these normal tissue protective properties, RRx-001 may be used to treat a broad spectrum of malignancies, if it is approved in the future.
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Affiliation(s)
| | | | - Kira Foygel
- b Department of Radiology , Stanford University , Palo Alto , CA , USA
| | | | - Susan J Knox
- c Department of Radiation Oncology , Stanford University , Palo Alto , CA , USA
| | - Donna Peehl
- d Department of Urology , Stanford University , Palo Alto , CA , USA
| | - Hongjuan Zhao
- d Department of Urology , Stanford University , Palo Alto , CA , USA
| | - Shoucheng Ning
- c Department of Radiation Oncology , Stanford University , Palo Alto , CA , USA
| | - Pedro Cabrales
- f Department of Bioengineering , University of California at San Diego (UCSD ) , La Jolla , CA , USA
| | - Thomas A Summers
- g Murtha Cancer Center , Walter Reed National Military Medical Center ; Bethesda , MD , USA
| | - Tony R Reid
- h Moores Cancer Center , University of California at San Diego (UCSD) , CA , USA
| | - William L Fitch
- e Department of Anesthesia , Stanford University , Palo Alto , CA , USA
| | | | - Jane B Trepel
- i National Cancer Institute , National Institutes of Health , Bethesda , MD , USA
| | - Min-Jung Lee
- i National Cancer Institute , National Institutes of Health , Bethesda , MD , USA
| | - Santosh Kesari
- j John Wayne Cancer Institute, Providence Saint John's Health Center , CA , USA
| | | | - Regina M Day
- l Department of pharmacology , Uniformed Services University , Bethesda , MD , USA
| | | | - Carolyn M Ray
- n Cancer Center, St. Francis Hospital , Hartford , CT , USA
| | - Corey A Carter
- g Murtha Cancer Center , Walter Reed National Military Medical Center ; Bethesda , MD , USA
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14
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Zhao H, Ning S, Scicinski J, Oronsky B, Knox SJ, Peehl DM. Epigenetic effects of RRx-001: a possible unifying mechanism of anticancer activity. Oncotarget 2016; 6:43172-81. [PMID: 26657731 PMCID: PMC4791224 DOI: 10.18632/oncotarget.6526] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 11/27/2015] [Indexed: 12/26/2022] Open
Abstract
RRx-001 is a novel aerospace-derived compound currently under investigation in several ongoing Phase II studies. In a Phase I trial, it demonstrated anti-cancer activity and evidence of resensitization to formerly effective therapies in heavily pre-treated patients with relapsed/refractory solid tumors. RRx-001 generates reactive oxygen and nitrogen species (ROS and RNS) and nitric oxide (NO), elicits changes in intracellular redox status, modulates tumor blood flow, hypoxia and vascular function and triggers apoptosis in cancer cells. We investigated the effect of RRx-001 on the epigenome of SCC VII cancer cells. RRx-001 at 0.5 and 2 μM significantly decreased global DNA methylation, i.e., 5-methylcytosine levels, in SCC VII cells. Consistently, 0.5-5 μM RRx-001 significantly decreased Dnmt1 and Dnmt3a protein expression in a dose- and time-dependent manner. In addition, global methylation profiling identified differentially methylated genes in SCC VII cells treated with 0.5, 2, and 5 μM RRx-001 compared to control cells. Twenty-three target sites were hypomethylated and 22 hypermethylated by >10% in the presence of at least two different concentrations of RRx-001. Moreover, RRx-001 at 2 μM significantly increased global acetylated histone H3 and H4 levels in SCC VII cells after 24 hour treatment, suggesting that RRx-001 regulates global acetylation in cancer cells. These results demonstrate that, in contrast to the traditional "one drug one target" paradigm, RRx-001 has multi(epi)target features, which contribute to its anti-cancer activity and may rationalize the resensitization to previously effective therapies observed in clinical trials and serve as a unifying mechanism for its anticancer activity.
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Affiliation(s)
- Hongjuan Zhao
- Department of Urology, Stanford University School of Medicine, Stanford, CA, USA
| | - Shoucheng Ning
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | | | | | - Susan J Knox
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Donna M Peehl
- Department of Urology, Stanford University School of Medicine, Stanford, CA, USA
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15
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Padín-Irizarry V, Colón-Lorenzo EE, Vega-Rodríguez J, Castro MDR, González-Méndez R, Ayala-Peña S, Serrano AE. Glutathione-deficient Plasmodium berghei parasites exhibit growth delay and nuclear DNA damage. Free Radic Biol Med 2016; 95:43-54. [PMID: 26952808 PMCID: PMC4934901 DOI: 10.1016/j.freeradbiomed.2016.02.032] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Revised: 02/26/2016] [Accepted: 02/28/2016] [Indexed: 01/15/2023]
Abstract
Plasmodium parasites are exposed to endogenous and exogenous oxidative stress during their complex life cycle. To minimize oxidative damage, the parasites use glutathione (GSH) and thioredoxin (Trx) as primary antioxidants. We previously showed that disruption of the Plasmodium berghei gamma-glutamylcysteine synthetase (pbggcs-ko) or the glutathione reductase (pbgr-ko) genes resulted in a significant reduction of GSH in intraerythrocytic stages, and a defect in growth in the pbggcs-ko parasites. In this report, time course experiments of parasite intraerythrocytic development and morphological studies showed a growth delay during the ring to schizont progression. Morphological analysis shows a significant reduction in size (diameter) of trophozoites and schizonts with increased number of cytoplasmic vacuoles in the pbggcs-ko parasites in comparison to the wild type (WT). Furthermore, the pbggcs-ko mutants exhibited an impaired response to oxidative stress and increased levels of nuclear DNA (nDNA) damage. Reduced GSH levels did not result in mitochondrial DNA (mtDNA) damage or protein carbonylations in neither pbggcs-ko nor pbgr-ko parasites. In addition, the pbggcs-ko mutant parasites showed an increase in mRNA expression of genes involved in oxidative stress detoxification and DNA synthesis, suggesting a potential compensatory mechanism to allow for parasite proliferation. These results reveal that low GSH levels affect parasite development through the impairment of oxidative stress reduction systems and damage to the nDNA. Our studies provide new insights into the role of the GSH antioxidant system in the intraerythrocytic development of Plasmodium parasites, with potential translation into novel pharmacological interventions.
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Affiliation(s)
- Vivian Padín-Irizarry
- Department of Microbiology and Medical Zoology, University of Puerto Rico, School of Medicine, San Juan 00936-5067, Puerto Rico
| | - Emilee E Colón-Lorenzo
- Department of Microbiology and Medical Zoology, University of Puerto Rico, School of Medicine, San Juan 00936-5067, Puerto Rico
| | - Joel Vega-Rodríguez
- Department of Microbiology and Medical Zoology, University of Puerto Rico, School of Medicine, San Juan 00936-5067, Puerto Rico
| | - María Del R Castro
- Department of Pharmacology and Toxicology, University of Puerto Rico, School of Medicine, San Juan 00936-5067, Puerto Rico
| | - Ricardo González-Méndez
- Department of Radiological Sciences, University of Puerto Rico, School of Medicine, San Juan 00936-5067, Puerto Rico
| | - Sylvette Ayala-Peña
- Department of Pharmacology and Toxicology, University of Puerto Rico, School of Medicine, San Juan 00936-5067, Puerto Rico
| | - Adelfa E Serrano
- Department of Microbiology and Medical Zoology, University of Puerto Rico, School of Medicine, San Juan 00936-5067, Puerto Rico.
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16
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Cabrales P, Scicinski J, Reid T, Kuypers F, Larkin S, Fens M, Oronsky A, Oronsky B. A look inside the mechanistic black box: Are red blood cells the critical effectors of RRx-001 cytotoxicity? Med Oncol 2016; 33:63. [PMID: 27229330 DOI: 10.1007/s12032-016-0775-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2016] [Accepted: 05/13/2016] [Indexed: 12/18/2022]
Abstract
The therapeutic potential of epi-immunotherapeutic anticancer agent RRx-001 in cancer has been validated with preclinical and clinical studies, since RRx-001 has successfully completed a phase 1 trial and multiple single-agent and combination phase 2 trials with preliminary evidence of promising activity are underway. Previous experimental work has implicated diverse anticancer mechanisms such as oxidative stress, ATP and NADPH depletion, anti-angiogenesis and epigenetic modulation in the overall antitumor effect of RRx-001. The hypothesis of this study was that the RRx-001 red blood cells are the essential and de facto intermediaries responsible for the reprograming of tumor behavior via transfer of their intracellular and membrane contents. To test this hypothesis, and thereby resolve the "black box" incompleteness in the continuity of the mechanism, the fate of red blood cells incubated with RRx-001 was explored in vitro and in vivo both in healthy animals and in tumor-bearing mice. The collective results establish that RRx-001-derivatized red blood cells are the critical "missing links" to explain the specificity and anticancer activity of RRx-001, including its immunomodulatory effects on tumor-associated macrophages. These experimental results delineate a novel erythrocyte-based mechanism without precedent in the annals of oncology and open the door to rational combination strategies with RRx-001 both in cancer therapy and beyond, particularly in disease states that affect red blood cell and vascular function such as malaria, leishmaniasis, sickle-cell disease and hemorrhagic shock.
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Affiliation(s)
- Pedro Cabrales
- Department of Bioengineering, University of California San Diego, La Jolla, CA, 92093, USA
| | - Jan Scicinski
- EpicentRx, Inc., 800 W El Camino Real, Suite 180, Mountain View, CA, 94040, USA
| | - Tony Reid
- Moores Cancer Center, University of California San Diego, La Jolla, CA, 92093, USA
| | - Frans Kuypers
- Children's Hospital Oakland Research Institute, Oakland, CA, 94609, USA
| | - Sandra Larkin
- Children's Hospital Oakland Research Institute, Oakland, CA, 94609, USA
| | - Marcel Fens
- Children's Hospital Oakland Research Institute, Oakland, CA, 94609, USA
| | | | - Bryan Oronsky
- EpicentRx, Inc., 800 W El Camino Real, Suite 180, Mountain View, CA, 94040, USA.
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