scholarly journals Strain dependent structural effects and in vivo efficacy of enterovirus-D68 inhibitors

2021 ◽  
Author(s):  
Thomas R Lane ◽  
Jianing Fu ◽  
Barbara Sherry ◽  
Bart Tarbet ◽  
Brett Hurst ◽  
...  
Keyword(s):  
Hydrophobic Interactions ◽  
Current Treatment ◽  
In Vivo Efficacy ◽  
Log Reduction ◽  
Acute Flaccid Myelitis ◽  
Potent Inhibition ◽  
Enterovirus D68 ◽  
Strain Dependent

Acute flaccid myelitis (AFM) leads to loss of limb control in young children and is likely due to Enterovirus-D68 (EV-D68), for which there is no current treatment. We have developed a lead isoxazole-3-carboxamide analog of pleconaril (11526092) which displayed potent inhibition of the pleconaril-resistant CVB3-Woodruff (IC50 6-20 nM), EV-D68 (IC50 58 nM), and other enteroviruses. A mouse respiratory model of EV-D68 infection, in which pleconaril is inactive, showed decreased viremia of 3 log units as well as statistically significant 1 log reduction in lung titer reduction at day 5 after treatment with 11526092. A cryo-electron microscopy (cryo-EM) structure of EV-D68 in complex with 11526092 suggests that the increased potency may be due to additional hydrophobic interactions. Cryo-EM structures of 11526092 and pleconaril demonstrate destabilization of EV-D68 (MO strain) compared to the previously described stabilization of EV-D68 (Fermon strain) with pleconaril, illustrating clear strain dependent mechanisms of this molecule. 11526092 represents a more potent inhibitor in vitro with in vivo efficacy providing a potential future treatment for EV-D68 and AFM, suggesting an improvement over pleconaril for further optimization.

scholarly journals Understanding Enterovirus D68-Induced Neurologic Disease: A Basic Science Review

Viruses ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 821 ◽  
Author(s):  
Hixon ◽  
Frost ◽  
Rudy ◽  
Messacar ◽  
Clarke ◽  
...  
Keyword(s):  
Genomic Sequence ◽  
The United States ◽  
Causal Link ◽  
In Vitro Models ◽  
Experimental Models ◽  
Acute Flaccid Myelitis ◽  
The Us ◽  
Enterovirus D68

In 2014, the United States (US) experienced an unprecedented epidemic of enterovirus D68 (EV-D68)-induced respiratory disease that was temporally associated with the emergence of acute flaccid myelitis (AFM), a paralytic disease occurring predominantly in children, that has a striking resemblance to poliomyelitis. Although a definitive causal link between EV-D68 infection and AFM has not been unequivocally established, rapidly accumulating clinical, immunological, and epidemiological evidence points to EV-D68 as the major causative agent of recent seasonal childhood AFM outbreaks in the US. This review summarizes evidence, gained from in vivo and in vitro models of EV-D68-induced disease, which demonstrates that contemporary EV-D68 strains isolated during and since the 2014 outbreak differ from historical EV-D68 in several factors influencing neurovirulence, including their genomic sequence, their receptor utilization, their ability to infect neurons, and their neuropathogenicity in mice. These findings provide biological plausibility that EV-D68 is a causal agent of AFM and provide important experimental models for studies of pathogenesis and treatment that are likely to be difficult or impossible in humans.

scholarly journals 1336. Assessment of the In Vivo Efficacy of WCK 5222 (Cefepime-Zidebactam) Against Carbapenems-Resistant Acinetobacter baumannii (CR-ACBN) in the Neutropenic Murine Thigh Infection Model

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S408-S408 ◽  
Author(s):  
Safa Almarzoky Abuhussain ◽  
Lindsay Avery ◽  
Kamilia Abdelraouf ◽  
David P Nicolau
Keyword(s):  
Intrinsic Activity ◽  
Infection Model ◽  
Research Support ◽  
In Vivo Efficacy ◽  
Log Reduction ◽  
Clinical Dose ◽  
The Mean ◽  
High Binding Affinity

Abstract Background Zidebactam (ZID) is a novel β-lactam enhancer with high binding affinity to PBP2 and intrinsic activity against many Gram-negative pathogens, with the exception of ACBN. ZID also inhibits β-lactamases but not OXA carbapenemases associated with ACBN or metallo-β-lactamases. However, WCK 5222 (a combination of cefepime [FEP] and ZID) has shown in vitro activity against ACBN, including OXA producers. Moreover, we have previously shown that WCK 5222 human-simulated regimen (HSR) causes extensive (i.e., >2 log) eradication of ACBN from neutropenic mice lung. This study aimed to evaluate the in vivo efficacy of the HSR of WCK 5222 compared with FEP HSR or ZID HSR alone against ACBN in the neutropenic murine thigh infection model. Methods Six CR-ACBN clinical isolates, including five isolates expressing OXA-23 or OXA-24, were studied. FEP and WCK 5222 MICs were 128 to >512 and 16 to 64 mg/L, respectively. The ZID MIC was >512 mg/L for all isolates. ICR mice were rendered transiently neutropenic via cyclophosphamide prior to thigh inoculation with bacterial suspensions of 107 CFU/mL. Treatment mice received either FEP HSR (equivalent to a clinical dose of 2 g IV q8h as a 1 hour infusion), ZID HSR (equivalent to a clinical dose of 1 g IV q8h as 1 hour infusion), or WCK 5222 HSR (FEP HSR + ZID HSR). Control mice were vehicle-dosed. Changes in log10 CFU/mL at 24 hours compared with 0 hours controls were measured to assess efficacy. Results The average log10 CFU/thigh at 0 hours across all isolates was 5.85 ± 0.22. Compared with 0 hours control, the mean bacterial growth at 24 hours in the untreated control mice, FEP HSR, and ZID HSR were 2.34 ± 0.93, 1.36 ± 1.40, and 2.04 ± 0.80 log10CFU/thigh, respectively. The WCK 5222 HSR produced a decline in bacterial burden for all isolates [mean reduction of −2.09 ± 1.01 log10CFU/thigh]; 4/6 isolates achieved ≥ 2-log reduction while ≥1-log reduction was attained with the remaining two isolates. Conclusion HSR of WCK 5222 showed potent in vivo activity against CR-ACBN expressing OXA carbapenemases in the murine thigh model which is attributed to the β-lactam enhancing effect of ZID, driven by the complementary PBP binding of FEP and ZID. These results support the clinical evaluation of WCK 5222 for the management of infections due to CR-ACBN. Disclosures D. P. Nicolau, Wockhardt: Investigator, Research support.

scholarly journals Characterization of LDD-2633 as a Novel RET Kinase Inhibitor with Anti-Tumor Effects in Thyroid Cancer

2021 ◽  
Vol 14 (1) ◽  
pp. 38
Author(s):  
Hyo Jeong Lee ◽  
Pyeonghwa Jeong ◽  
Yeongyu Moon ◽  
Jungil Choi ◽  
Jeong Doo Heo ◽  
...  
Keyword(s):  
Thyroid Cancer ◽  
Thyroid Carcinoma ◽  
Kinase Inhibitor ◽  
Point Mutations ◽  
Carcinoma Cells ◽  
Medullary Thyroid ◽  
Potent Inhibition ◽  
Kinase Inhibitory Activity

Rearranged during transfection (RET), a receptor tyrosine kinase, is activated by glial cell line-derived neurotrophic factor family ligands. Chromosomal rearrangement or point mutations in RET are observed in patients with papillary thyroid and medullary thyroid carcinomas. Oncogenic alteration of RET results in constitutive activation of RET activity. Therefore, inhibiting RET activity has become a target in thyroid cancer therapy. Here, the anti-tumor activity of a novel RET inhibitor was characterized in medullary thyroid carcinoma cells. The indirubin derivative LDD-2633 was tested for RET kinase inhibitory activity. In vitro, LDD-2633 showed potent inhibition of RET kinase activity, with an IC50 of 4.42 nM. The growth of TT thyroid carcinoma cells harboring an RET mutation was suppressed by LDD-2633 treatment via the proliferation suppression and the induction of apoptosis. The effects of LDD-2633 on the RET signaling pathway were examined; LDD-2633 inhibited the phosphorylation of the RET protein and the downstream molecules Shc and ERK1/2. Oral administration of 20 or 40 mg/kg of LDD-2633 induced dose-dependent suppression of TT cell xenograft tumor growth. The in vivo and in vitro experimental results supported the potential use of LDD-2633 as an anticancer drug for thyroid cancers.

scholarly journals Intracellular localisation of Mycobacterium tuberculosis affects efficacy of the antibiotic pyrazinamide

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Pierre Santucci ◽  
Daniel J. Greenwood ◽  
Antony Fearns ◽  
Kai Chen ◽  
Haibo Jiang ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Host Cell ◽  
Combination Chemotherapy ◽  
In Vitro Activity ◽  
In Vivo Efficacy ◽  
Human Macrophages ◽  
Ion Microscopy ◽  
Intracellular Localisation

AbstractTo be effective, chemotherapy against tuberculosis (TB) must kill the intracellular population of the pathogen, Mycobacterium tuberculosis. However, how host cell microenvironments affect antibiotic accumulation and efficacy remains unclear. Here, we use correlative light, electron, and ion microscopy to investigate how various microenvironments within human macrophages affect the activity of pyrazinamide (PZA), a key antibiotic against TB. We show that PZA accumulates heterogeneously among individual bacteria in multiple host cell environments. Crucially, PZA accumulation and efficacy is maximal within acidified phagosomes. Bedaquiline, another antibiotic commonly used in combined TB therapy, enhances PZA accumulation via a host cell-mediated mechanism. Thus, intracellular localisation and specific microenvironments affect PZA accumulation and efficacy. Our results may explain the potent in vivo efficacy of PZA, compared to its modest in vitro activity, and its critical contribution to TB combination chemotherapy.

scholarly journals P074 In vitro and in vivo efficacy of linezolid on Treponema pallidum, the syphilis agent

2021 ◽  
Author(s):  
L Giacani ◽  
A Haynes ◽  
M Vall Mayans ◽  
M Ubals Cazorla ◽  
C Nieto ◽  
...  
Keyword(s):  
Treponema Pallidum ◽  
In Vivo Efficacy

scholarly journals Efficacy of a novel lantibiotic, CMB001, against MRSA

2021 ◽  
Author(s):  
Jerzy Karczewski ◽  
Christine M Brown ◽  
Yukari Maezato ◽  
Stephen P Krasucki ◽  
Stephen J Streatfield
Keyword(s):  
Antibacterial Activity ◽  
Pharmacokinetic Analysis ◽  
Maximum Tolerable Dose ◽  
In Vivo Efficacy ◽  
Clostridioides Difficile ◽  
Alternative Treatment Option ◽  
Significant Damage ◽  
Tolerable Dose

Abstract Objectives To evaluate the efficacy of a novel lantibiotic, CMB001, against MRSA biofilms in vitro and in an in vivo experimental model of bacterial infection. Methods Antibacterial activity of CMB001 was measured in vitro after its exposure to whole blood or to platelet-poor plasma. In vitro efficacy of CMB001 against a Staphylococcus aureus biofilm was studied using scanning electron microscopy. The maximum tolerable dose in mice was determined and a preliminary pharmacokinetic analysis for CMB001 was performed in mice. In vivo efficacy was evaluated in a neutropenic mouse thigh model of infection. Results CMB001 maintained its antibacterial activity in the presence of blood or plasma for up to 24 h at 37°C. CMB001 efficiently killed S. aureus within the biofilm by causing significant damage to the bacterial cell wall. The maximum tolerable dose in mice was established to be 10 mg/kg and could be increased to 30 mg/kg in mice pretreated with antihistamines. In neutropenic mice infected with MRSA, treatment with CMB001 reduced the bacterial burden with an efficacy equivalent to that of vancomycin. Conclusions CMB001 offers potential as an alternative treatment option to combat MRSA. It will be of interest to evaluate the in vivo efficacy of CMB001 against infections caused by other pathogens, including Clostridioides difficile and Acinetobacter baumannii, and to expand its pharmacokinetic/pharmacodynamic parameters and safety profile.

scholarly journals Lysyl oxidase activity and elastin/glycosaminoglycan interactions in growing chick and rat aortas.

1987 ◽  
Vol 105 (3) ◽  
pp. 1463-1469 ◽  
Author(s):  
C Fornieri ◽  
M Baccarani-Contri ◽  
D Quaglino ◽  
I Pasquali-Ronchetti
Keyword(s):  
Hydrophobic Interactions ◽  
Isonicotinic Acid ◽  
Lysyl Oxidase ◽  
Acid Hydrazide ◽  
Elastic Fibers ◽  
Amino Groups ◽  
Lysine Residues ◽  
Oxidase Inhibition

Hydrophobic tropoelastin molecules aggregate in vitro in physiological conditions and form fibers very similar to natural ones (Bressan, G. M., I. Pasquali Ronchetti, C. Fornieri, F. Mattioli, I. Castellani, and D. Volpin, 1986, J. Ultrastruct. Molec. Struct. Res., 94:209-216). Similar hydrophobic interactions might be operative in in vivo fibrogenesis. Data are presented suggesting that matrix glycosaminoglycans (GAGs) prevent spontaneous tropoelastin aggregation in vivo, at least up to the deamination of lysine residues on tropoelastin by matrix lysyl oxidase. Lysyl oxidase inhibitors beta-aminopropionitrile, aminoacetonitrile, semicarbazide, and isonicotinic acid hydrazide were given to newborn chicks, to chick embryos, and to newborn rats, and the ultrastructural alterations of the aortic elastic fibers were analyzed and compared with the extent of the enzyme inhibition. When inhibition was greater than 65% all chemicals induced alterations of elastic fibers in the form of lateral aggregates of elastin, which were always permeated by cytochemically and immunologically recognizable GAGs. The number and size of the abnormal elastin/GAGs aggregates were proportional to the extent of lysyl oxidase inhibition. The phenomenon was independent of the animal species. All data suggest that, upon inhibition of lysyl oxidase, matrix GAGs remain among elastin molecules during fibrogenesis by binding to positively charged amino groups on elastin. Newly synthesized and secreted tropoelastin has the highest number of free epsilon amino groups, and, therefore, the highest capability of binding to GAGs. These polyanions, by virtue of their great hydration and dispersing power, could prevent random spontaneous aggregation of hydrophobic tropoelastin in the extracellular space.

scholarly journals Screening marine algae metabolites as high-affinity inhibitors of SARS-CoV-2 main protease (3CLpro): an in silico analysis to identify novel drug candidates to combat COVID-19 pandemic

2020 ◽  
Vol 63 (1) ◽  
Author(s):  
Ghazala Muteeb ◽  
Adil Alshoaibi ◽  
Mohammad Aatif ◽  
Md. Tabish Rehman ◽  
M. Zuhaib Qayyum
Keyword(s):  
Hydrophobic Interactions ◽  
In Silico Analysis ◽  
Salt Bridge ◽  
Competitive Inhibitor ◽  
Binding Energies ◽  
Dynamics Simulation ◽  
In Vivo Studies ◽  
Energy Calculation

AbstractThe recent dissemination of SARS-CoV-2 from Wuhan city to all over the world has created a pandemic. COVID-19 has cost many human lives and created an enormous economic burden. Although many drugs/vaccines are in different stages of clinical trials, still none is clinically available. We have screened a marine seaweed database (1110 compounds) against 3CLpro of SARS-CoV-2 using computational approaches. High throughput virtual screening was performed on compounds, and 86 of them with docking score <  − 5.000 kcal mol−1 were subjected to standard-precision docking. Based on binding energies (< − 6.000 kcal mol−1), 9 compounds were further shortlisted and subjected to extra-precision docking. Free energy calculation by Prime-MM/GBSA suggested RC002, GA004, and GA006 as the most potent inhibitors of 3CLpro. An analysis of ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) properties of RC002, GA004, and GA006 indicated that only RC002 (callophysin A, from red alga Callophycus oppositifolius) passed Lipinski’s, Veber’s, PAINS and Brenk’s filters and displayed drug-like and lead-like properties. Analysis of 3CLpro-callophysin A complex revealed the involvement of salt bridge, hydrogen bonds, and hydrophobic interactions. callophysin A interacted with the catalytic residues (His41 and Cys145) of 3CLpro; hence it may act as a mechanism-based competitive inhibitor. Docking energy and docking affinity of callophysin A towards 3CLpro was − 8.776 kcal mol−1 and 2.73 × 106 M−1, respectively. Molecular dynamics simulation confirmed the stability of the 3CLpro-callophysin A complex. The findings of this study may serve as the basis for further validation by in vitro and in vivo studies.

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