scholarly journals Mammalian Deubiquitinating Enzyme Inhibitors Display in Vitro and in Vivo Activity against Malaria Parasites and Potentiate Artemisinin Action

2021 ◽  
Author(s):  
Nelson V. Simwela ◽  
Katie R. Hughes ◽  
Michael T. Rennie ◽  
Michael P. Barrett ◽  
Andrew P. Waters
Keyword(s):  
Enzyme Inhibitors ◽  
Deubiquitinating Enzyme ◽  
Malaria Parasites

scholarly journals Mammalian deubiquitinating enzyme inhibitors display in vitro and in vivo activity against malaria parasites and potentiate artemisinin action

2020 ◽  
Author(s):  
Nelson V. Simwela ◽  
Katie R. Hughes ◽  
Michael T. Rennie ◽  
Michael P. Barrett ◽  
Andrew P. Waters
Keyword(s):  
Anticancer Agents ◽  
Drug Targets ◽  
Reverse Genetics ◽  
Enzyme Inhibitors ◽  
Artemisinin Resistance ◽  
Drug Repurposing ◽  
Antimalarial Drugs ◽  
Malaria Parasites

AbstractCurrent malaria control efforts rely significantly on artemisinin combinational therapies which have played massive roles in alleviating the global burden of the disease. Emergence of resistance to artemisinins is therefore, not just alarming but requires immediate intervention points such as development of new antimalarial drugs or improvement of the current drugs through adjuvant or combination therapies. Artemisinin resistance is primarily conferred by Kelch13 propeller mutations which are phenotypically characterised by generalised growth quiescence, altered haemoglobin trafficking and downstream enhanced activity of the parasite stress pathways through the ubiquitin proteasome system (UPS). Previous work on artemisinin resistance selection in a rodent model of malaria, which we and others have recently validated using reverse genetics, has also shown that mutations in deubiquitinating enzymes, DUBs (upstream UPS component) modulates susceptibility of malaria parasites to both artemisinin and chloroquine. The UPS or upstream protein trafficking pathways have, therefore, been proposed to be not just potential drug targets, but also possible intervention points to overcome artemisinin resistance. Here we report the activity of small molecule inhibitors targeting mammalian DUBs in malaria parasites. We show that generic DUB inhibitors can block intraerythrocytic development of malaria parasites in vitro and possess antiparasitic activity in vivo and can be used in combination with additive effect. We also show that inhibition of these upstream components of the UPS can potentiate the activity of artemisinin in vitro as well as in vivo to the extent that ART resistance can be overcome. Combinations of DUB inhibitors anticipated to target different DUB activities and downstream 20s proteasome inhibitors are even more effective at improving the potency of artemisinins than either inhibitors alone providing proof that targeting multiple UPS activities simultaneously could be an attractive approach to overcoming artemisinin resistance. These data further validate the parasite UPS as a target to both enhance artemisinin action and potentially overcome resistance. Lastly, we confirm that DUB inhibitors can be developed into in vivo antimalarial drugs with promise for activity against all of human malaria and could thus further exploit their current pursuit as anticancer agents in rapid drug repurposing programs.Graphical abstract

scholarly journals Ex VivoMaturation Assay for Testing Antimalarial Sensitivity of Rodent Malaria Parasites

2016 ◽  
Vol 60 (11) ◽  
pp. 6859-6866 ◽  
Author(s):  
Zi Wei Chang ◽  
Benoit Malleret ◽  
Bruce Russell ◽  
Laurent Rénia ◽  
Carla Claser
Keyword(s):  
Ex Vivo ◽  
Single Step ◽  
Parasite Development ◽  
Ring Stage ◽  
Malaria Parasites ◽  
Rodent Malaria ◽  
Content Type ◽  
Parasite Biology

ABSTRACTEx vivoassay systems provide a powerful approach to studying human malaria parasite biology and to testing antimalarials. For rodent malaria parasites, short-termin vitroculture andex vivoantimalarial susceptibility assays are relatively cumbersome, relying onin vivopassage for synchronization, since ring-stage parasites are an essential starting material. Here, we describe a new approach based on the enrichment of ring-stagePlasmodium berghei,P. yoelii, andP. vinckei vinckeiusing a single-step Percoll gradient. Importantly, we demonstrate that the enriched ring-stage parasites develop synchronously regardless of the parasite strain or species used. Using a flow cytometry assay with Hoechst and ethidium or MitoTracker dye, we show that parasite development is easily and rapidly monitored. Finally, we demonstrate that this approach can be used to screen antimalarial drugs.

scholarly journals A therapeutic combination of two small molecule toxin inhibitors provides pancontinental preclinical efficacy against viper snakebite

2020 ◽  
Author(s):  
Laura-Oana Albulescu ◽  
Chunfang Xie ◽  
Stuart Ainsworth ◽  
Jaffer Alsolaiss ◽  
Edouard Crittenden ◽  
...  
Keyword(s):  
Small Molecules ◽  
Enzyme Inhibitors ◽  
Interspecific Variation ◽  
Medical Emergency ◽  
Dual Inhibitor ◽  
Mortality And Morbidity ◽  
Venom Composition ◽  
Inhibitor Combination

AbstractSnakebite is a medical emergency causing high mortality and morbidity in rural tropical communities that typically experience delayed access to unaffordable therapeutics. Viperid snakes are responsible for the majority of envenomings, but extensive interspecific variation in venom composition dictates that different antivenom treatments are used in different parts of the world, resulting in clinical and fiscal snakebite management challenges. Here, we show that a number of repurposed Phase 2-approved small molecules are capable of broadly neutralizing distinct viper venom bioactivities in vitro by inhibiting different enzymatic toxin families. Furthermore, using multiple in vivo models of envenoming, we demonstrate that a single dose of a rationally-selected dual inhibitor combination consisting of marimastat and varespladib prevents lethality caused by venom from the most medically-important vipers of Africa, South Asia and Central America. Our findings strongly support the translation of combinations of safe and affordable enzyme inhibitors as novel broad-spectrum therapeutics for snakebite.

scholarly journals Assay Systems for Profiling Deubiquitinating Activity

2020 ◽  
Vol 21 (16) ◽  
pp. 5638
Author(s):  
Jinhong Cho ◽  
Jinyoung Park ◽  
Eunice EunKyeong Kim ◽  
Eun Joo Song
Keyword(s):  
Protein Degradation ◽  
Protein Interactions ◽  
Live Cells ◽  
Deubiquitinating Enzyme ◽  
Protein Protein Interactions ◽  
Deubiquitinating Enzymes ◽  
Cell Lysates ◽  
Cellular Processes

Deubiquitinating enzymes regulate various cellular processes, particularly protein degradation, localization, and protein–protein interactions. The dysregulation of deubiquitinating enzyme (DUB) activity has been linked to several diseases; however, the function of many DUBs has not been identified. Therefore, the development of methods to assess DUB activity is important to identify novel DUBs, characterize DUB selectivity, and profile dynamic DUB substrates. Here, we review various methods of evaluating DUB activity using cell lysates or purified DUBs, as well as the types of probes used in these methods. In addition, we introduce some techniques that can deliver DUB probes into the cells and cell-permeable activity-based probes to directly visualize and quantify DUB activity in live cells. This review could contribute to the development of DUB inhibitors by providing important information on the characteristics and applications of various probes used to evaluate and detect DUB activity in vitro and in vivo.

scholarly journals USP19 deubiquitinating enzyme inhibits muscle cell differentiation by suppressing unfolded-protein response signaling

2015 ◽  
Vol 26 (5) ◽  
pp. 913-923 ◽  
Author(s):  
Benjamin Wiles ◽  
Miao Miao ◽  
Erin Coyne ◽  
Louise Larose ◽  
Andrey V. Cybulsky ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Unfolded Protein Response ◽  
Muscle Cell ◽  
Deubiquitinating Enzyme ◽  
Muscle Cell Differentiation ◽  
Unfolded Protein ◽  
The Unfolded Protein Response ◽  
Protein Response

USP19 deubiquitinating enzyme has two isoforms, cytoplasmic and endoplasmic reticulum (ER) localized. The ER-localized isoform specifically suppresses muscle cell differentiation in vitro and appears to do so by inhibiting the unfolded-protein response that occurs during such differentiation. In vivo, loss of USP19 promotes muscle regeneration following injury.

Synergy of the antiretroviral protease inhibitor indinavir and chloroquine against malaria parasites in vitro and in vivo

2011 ◽  
Vol 109 (6) ◽  
pp. 1519-1524 ◽  
Author(s):  
Xiaofen Li ◽  
Zhengxiang He ◽  
Lili Chen ◽  
Yayong Li ◽  
Qinyan Li ◽  
...  
Keyword(s):  
Protease Inhibitor ◽  
Malaria Parasites

In vivo and in vitro effect of androstene derivatives as 5α-reductase type 1 enzyme inhibitors

2012 ◽  
Vol 28 (6) ◽  
pp. 1247-1254 ◽  
Author(s):  
Eugene Bratoeff ◽  
Araceli Sánchez ◽  
Yazmín Arellano ◽  
Yvonne Heuze ◽  
Juan Soriano ◽  
...  
Keyword(s):  
Enzyme Inhibitors ◽  
Vitro Effect

In vitro and in vivo antimalarial activity of ferrochloroquine, a ferrocenyl analogue of chloroquine against chloroquine-resistant malaria parasites

2001 ◽  
Vol 87 (3) ◽  
pp. 239-244 ◽  
Author(s):  
L. Delhaes ◽  
H. Abessolo ◽  
L. Berry ◽  
P. Delcourt ◽  
L. Maciejewski ◽  
...  
Keyword(s):  
Antimalarial Activity ◽  
Malaria Parasites

scholarly journals Synthesis and Evaluation of Chirally Defined Side Chain Variants of 7-Chloro-4-Aminoquinoline To Overcome Drug Resistance in Malaria Chemotherapy

2016 ◽  
Vol 61 (3) ◽  
Author(s):  
Vasantha Rao Dola ◽  
Awakash Soni ◽  
Pooja Agarwal ◽  
Hafsa Ahmad ◽  
Kanumuri Siva Rama Raju ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Solid State ◽  
Side Chain ◽  
Detailed Structure ◽  
Preclinical Development ◽  
Malaria Parasites ◽  
Sar Studies ◽  
Structure Activity

ABSTRACT A novel 4-aminoquinoline derivative [(S)-7-chloro-N-(4-methyl-1-(4-methylpiperazin-1-yl)pentan-2-yl)-quinolin-4-amine triphosphate] exhibiting curative activity against chloroquine-resistant malaria parasites has been identified for preclinical development as a blood schizonticidal agent. The lead molecule selected after detailed structure-activity relationship (SAR) studies has good solid-state properties and promising activity against in vitro and in vivo experimental malaria models. The in vitro absorption, distribution, metabolism, and excretion (ADME) parameters indicate a favorable drug-like profile.

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