scholarly journals Screening of the NIH Clinical Collection for inhibitors of HIV-1 integrase activity

2018 ◽  
Vol 114 (3/4) ◽  
Author(s):  
Shaakira Abrahams ◽  
Salerwe Mosebi ◽  
Muhammed Q. Fish ◽  
Maria A. Papathanasopoulos ◽  
Raymond Hewer

Drug repurposing offers a validated approach to reduce drug attrition within the drug discovery and development pipeline through the application of known drugs and drug candidates to treat new indications. Full exploitation of this strategy necessitates the screening of a vast number of molecules against an extensive number of diseases of high burden or unmet need and the subsequent dissemination of the findings. In order to contribute to endeavours within this field, we screened the 727 compounds comprising the US National Institutes of Health (NIH) Clinical Collection through an HIV-1 (human immunodeficiency virus type 1) integrase stand transfer inhibition assay on an automated scintillation proximity assay platform. Only two compounds were identified within the initial screen, with cefixime trihydrate and epigallocatechin gallate found to reduce integrase strand transfer activity at IC50 values of 6.03±1.29 μM and 9.57±1.62 μM, respectively. However, both cefixime trihydrate and epigallocatechin gallate retained their low micromolar inhibitory activity when tested against a raltegravir-resistant integrase double mutant (FCIC50 values of 0.83 and 0.06, respectively), were ineffective in an orthogonal strand transfer ELISA (less than 30% inhibition at 100 μM) and produced negligible selectivity index values (less than 1) in vitro. While no useful inhibitors of HIV-1 integrase strand transfer activity were found within the NIH Clinical Collection, the identification of two assay-disrupting molecules demonstrates the importance of consideration of non-specific inhibitors in drug repurposing screens.

2021 ◽  
Author(s):  
Vandana Mishra ◽  
Ishan Rathore ◽  
Anuradha Deshmukh ◽  
Swati Patankar ◽  
Alla Gustchina ◽  
...  

Malaria is a deadly disease, and the worldwide emergence of drug resistance in the Plasmodium parasites demands the development of novel and potent antimalarials. HIV-1 protease inhibitors (HIV-1 PIs) alleviate the Plasmodium pathogenesis during malaria/HIV-1 co-infection plausibly by inhibiting vacuolar plasmepsins (PMs), the hemoglobin degrading proteases from P. falciparum. All five FDA-approved HIV-1 PIs tested against PMII exhibit the Ki values in the low micromolar range of which RTV and LPV display the highest inhibition activity. Both inhibitors impede in vitro growth of P. falciparum at low micromolar IC50 values. We report the first crystal structures of PMII complexed with RTV and LPV that reveal the binding mode and interactions of the inhibitors in the active site as well as elucidate the mechanism underlying their differential potency. The conformational flexibility of the P4 group in RTV allows it to explore multiple regions of the S4 pocket. The present study establishes vacuolar PMs as potential drug targets of HIV-1 PIs. The molecular details explaining the inhibitory mechanism of HIV-1 PIs might be crucial in designing novel and potent antimalarial analogs. This work strengthens the prospect of drug repurposing as an alternative strategy towards antimalarial treatments and provides an opportunity to tackle malaria and HIV-1 co-infection.


2020 ◽  
Vol 17 (4) ◽  
pp. 418-427
Author(s):  
Pankaj Wadhwa ◽  
Priti Jain ◽  
Hemant R. Jadhav

Background: A series of eighteen 2-Oxo-N-substituted phenyl- 2H-chromene-3- carboxamide analogues has been evaluated for HIV-1 integrase (IN) inhibition. Methods: The derivatives were synthesized via a two-step pathway commencing with 2- hydroxybenzaldehyde and diethyl malonate followed by hydrolysis of ester and coupling with various aromatic amines. The HIV-1 IN inhibitory potential of these compounds has been studied relative to dolutegravir, a known HIV-1 IN inhibitor using a standard available kit. Results: Six molecules (compounds 13h, 13i, 13l, 13p to 13r) showed significant inhibition of HIV- 1 integrase 3′-strand transfer with IC50 values less than 1.7 μM. The presence of chromene-3- carboxamide motif was shown to be crucial for the enzymatic activity. In addition, molecular modelling studies were also done to justify the IN inhibition and in vitro-in silico correlation was drawn. Conclusion: However, these compounds did not show HIV-1 and HIV-2 inhibition below their cytotoxic concentration indicating that these compounds cannot be taken further for anti-HIV activity as such and require structural modification.


Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 873
Author(s):  
Raphael J. Eberle ◽  
Danilo S. Olivier ◽  
Marcos S. Amaral ◽  
Ian Gering ◽  
Dieter Willbold ◽  
...  

Since the first report of a new pneumonia disease in December 2019 (Wuhan, China) the WHO reported more than 148 million confirmed cases and 3.1 million losses globally up to now. The causative agent of COVID-19 (SARS-CoV-2) has spread worldwide, resulting in a pandemic of unprecedented magnitude. To date, several clinically safe and efficient vaccines (e.g., Pfizer-BioNTech, Moderna, Johnson & Johnson, and AstraZeneca COVID-19 vaccines) as well as drugs for emergency use have been approved. However, increasing numbers of SARS-Cov-2 variants make it imminent to identify an alternative way to treat SARS-CoV-2 infections. A well-known strategy to identify molecules with inhibitory potential against SARS-CoV-2 proteins is repurposing clinically developed drugs, e.g., antiparasitic drugs. The results described in this study demonstrated the inhibitory potential of quinacrine and suramin against SARS-CoV-2 main protease (3CLpro). Quinacrine and suramin molecules presented a competitive and noncompetitive inhibition mode, respectively, with IC50 values in the low micromolar range. Surface plasmon resonance (SPR) experiments demonstrated that quinacrine and suramin alone possessed a moderate or weak affinity with SARS-CoV-2 3CLpro but suramin binding increased quinacrine interaction by around a factor of eight. Using docking and molecular dynamics simulations, we identified a possible binding mode and the amino acids involved in these interactions. Our results suggested that suramin, in combination with quinacrine, showed promising synergistic efficacy to inhibit SARS-CoV-2 3CLpro. We suppose that the identification of effective, synergistic drug combinations could lead to the design of better treatments for the COVID-19 disease and repurposable drug candidates offer fast therapeutic breakthroughs, mainly in a pandemic moment.


2021 ◽  
Author(s):  
Büşra Aydin ◽  
Sema Arslan ◽  
Fatih Bayraklı ◽  
Betül Karademir ◽  
Kazim Yalcin Arga

Introduction: Prolactinomas, also called lactotroph adenomas, are the most encountered type of hormone-secreting pituitary neuroendocrine tumors (PitNET) in the clinic. The preferred first-line therapy is a medical treatment with dopamine agonists (DA), mainly cabergoline, to reduce serum prolactin levels, tumor volume, and mass effect. However, in some cases, patients have displayed DA-resistance with aggressive tumor behavior or are faced with recurrence after drug withdrawal. Also, currently used therapeutics have notorious side effects and impair the life quality of the patients. Methods: Since the amalgamation of clinical and laboratory data besides tumor histopathogenesis and transcriptional regulatory features of the tumor emerge to exhibit essential roles in the behavior and progression of prolactinomas, in this work, we integrated mRNA and microRNA (miRNA) level transcriptome data that exploit disease-specific signatures in addition to biological and pharmacological data to elucidate a rational prioritization of pathways and drugs in prolactinoma. Results: We identified eight drug candidates through drug repurposing based on mRNA-miRNA level data integration and evaluated their potential through in vitro assays in the MMQ cell line. Seven re-purposed drugs including 5-flourocytosine, nortriptyline, neratinib, puromycin, taxifolin, vorinostat, and zileuton were proposed as potential drug candidates for the treatment of prolactinoma. We further hypothesized possible mechanisms of drug action on MMQ cell viability through analyzing PI3K/Akt signaling pathway and cell cycle arrest via flow cytometry and western blotting. Discussion: We presented the transcriptomic landscape of prolactinoma through miRNA and mRNA level data integration and proposed repurposed drug candidates based on this integration. We validated our findings through testing cell viability, cell cycle phases, and PI3K/Akt protein expressions. Effects of the drugs on cell cycle phases and inhibition of PI3K/Akt pathway by all drugs gave us promising output for further studies using these drugs in the treatment of prolactinoma. This is the first study that reports miRNA-mediated repurposed drugs for prolactinoma treatment via in vitro experiments.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3213
Author(s):  
Alon Ben David ◽  
Eran Diamant ◽  
Eyal Dor ◽  
Ada Barnea ◽  
Niva Natan ◽  
...  

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the coronavirus disease 2019 (COVID-19) global pandemic. The first step of viral infection is cell attachment, which is mediated by the binding of the SARS-CoV-2 receptor binding domain (RBD), part of the virus spike protein, to human angiotensin-converting enzyme 2 (ACE2). Therefore, drug repurposing to discover RBD-ACE2 binding inhibitors may provide a rapid and safe approach for COVID-19 therapy. Here, we describe the development of an in vitro RBD-ACE2 binding assay and its application to identify inhibitors of the interaction of the SARS-CoV-2 RBD to ACE2 by the high-throughput screening of two compound libraries (LOPAC®1280 and DiscoveryProbeTM). Three compounds, heparin sodium, aurintricarboxylic acid (ATA), and ellagic acid, were found to exert an effective binding inhibition, with IC50 values ranging from 0.6 to 5.5 µg/mL. A plaque reduction assay in Vero E6 cells infected with a SARS-CoV-2 surrogate virus confirmed the inhibition efficacy of heparin sodium and ATA. Molecular docking analysis located potential binding sites of these compounds in the RBD. In light of these findings, the screening system described herein can be applied to other drug libraries to discover potent SARS-CoV-2 inhibitors.


2015 ◽  
Vol 89 (16) ◽  
pp. 8119-8129 ◽  
Author(s):  
Eytan Herzig ◽  
Nickolay Voronin ◽  
Nataly Kucherenko ◽  
Amnon Hizi

ABSTRACTThe process of reverse transcription (RTN) in retroviruses is essential to the viral life cycle. This key process is catalyzed exclusively by the viral reverse transcriptase (RT) that copies the viral RNA into DNA by its DNA polymerase activity, while concomitantly removing the original RNA template by its RNase H activity. During RTN, the combination between DNA synthesis and RNA hydrolysis leads to strand transfers (or template switches) that are critical for the completion of RTN. The balance between these RT-driven activities was considered to be the sole reason for strand transfers. Nevertheless, we show here that a specific mutation in HIV-1 RT (L92P) that does not affect the DNA polymerase and RNase H activities abolishes strand transfer. There is also a good correlation between this complete loss of the RT's strand transfer to the loss of the DNA clamp activity of the RT, discovered recently by us. This finding indicates a mechanistic linkage between these two functions and that they are both direct and unique functions of the RT (apart from DNA synthesis and RNA degradation). Furthermore, when the RT's L92P mutant was introduced into an infectious HIV-1 clone, it lost viral replication, due to inefficient intracellular strand transfers during RTN, thus supporting thein vitrodata. As far as we know, this is the first report on RT mutants that specifically and directly impair RT-associated strand transfers. Therefore, targeting residue Leu92 may be helpful in selectively blocking this RT activity and consequently HIV-1 infectivity and pathogenesis.IMPORTANCEReverse transcription in retroviruses is essential for the viral life cycle. This multistep process is catalyzed by viral reverse transcriptase, which copies the viral RNA into DNA by its DNA polymerase activity (while concomitantly removing the RNA template by its RNase H activity). The combination and balance between synthesis and hydrolysis lead to strand transfers that are critical for reverse transcription completion. We show here for the first time that a single mutation in HIV-1 reverse transcriptase (L92P) selectively abolishes strand transfers without affecting the enzyme's DNA polymerase and RNase H functions. When this mutation was introduced into an infectious HIV-1 clone, viral replication was lost due to an impaired intracellular strand transfer, thus supporting thein vitrodata. Therefore, finding novel drugs that target HIV-1 reverse transcriptase Leu92 may be beneficial for developing new potent and selective inhibitors of retroviral reverse transcription that will obstruct HIV-1 infectivity.


2014 ◽  
Vol 58 (6) ◽  
pp. 3233-3244 ◽  
Author(s):  
Craig Fenwick ◽  
Ma'an Amad ◽  
Murray D. Bailey ◽  
Richard Bethell ◽  
Michael Bös ◽  
...  

ABSTRACTBI 224436 is an HIV-1 integrase inhibitor with effective antiviral activity that acts through a mechanism that is distinct from that of integrase strand transfer inhibitors (INSTIs). This 3-quinolineacetic acid derivative series was identified using an enzymatic integrase long terminal repeat (LTR) DNA 3′-processing assay. A combination of medicinal chemistry, parallel synthesis, and structure-guided drug design led to the identification of BI 224436 as a candidate for preclinical profiling. It has antiviral 50% effective concentrations (EC50s) of <15 nM against different HIV-1 laboratory strains and cellular cytotoxicity of >90 μM. BI 224436 also has a low, ∼2.1-fold decrease in antiviral potency in the presence of 50% human serum and, by virtue of a steep dose-response curve slope, exhibits serum-shifted EC95values ranging between 22 and 75 nM. Passage of virus in the presence of inhibitor selected for either A128T, A128N, or L102F primary resistance substitutions, all mapping to a conserved allosteric pocket on the catalytic core of integrase. BI 224436 also retains full antiviral activity against recombinant viruses encoding INSTI resistance substitutions N155S, Q148H, and E92Q. In drug combination studies performed in cellular antiviral assays, BI 224436 displays an additive effect in combination with most approved antiretrovirals, including INSTIs. BI 224436 has drug-likein vitroabsorption, distribution, metabolism, and excretion (ADME) properties, including Caco-2 cell permeability, solubility, and low cytochrome P450 inhibition. It exhibited excellent pharmacokinetic profiles in rat (clearance as a percentage of hepatic flow [CL], 0.7%; bioavailability [F], 54%), monkey (CL, 23%;F, 82%), and dog (CL, 8%;F, 81%). Based on the excellent biological and pharmacokinetic profile, BI 224436 was advanced into phase 1 clinical trials.


1998 ◽  
Vol 72 (8) ◽  
pp. 6716-6724 ◽  
Author(s):  
Jianhui Guo ◽  
Tiyun Wu ◽  
Julian Bess ◽  
Louis E. Henderson ◽  
Judith G. Levin

ABSTRACT In this report we demonstrate that human immunodeficiency virus type 1 (HIV-1) minus-strand transfer, assayed in vitro and in endogenous reactions, is greatly inhibited by actinomycin D. Previously we showed that HIV-1 nucleocapsid (NC) protein (a nucleic acid chaperone catalyzing nucleic acid rearrangements which lead to more thermodynamically stable conformations) dramatically stimulates HIV-1 minus-strand transfer by preventing TAR-dependent self-priming from minus-strand strong-stop DNA [(−) SSDNA]. Despite this potent activity, the addition of NC to in vitro reactions with actinomycin D results in only a modest increase in the 50% inhibitory concentration (IC50) for the drug. PCR analysis of HIV-1 endogenous reactions indicates that minus-strand transfer is inhibited by the drug with an IC50 similar to that observed when NC is present in the in vitro system. Taken together, these results demonstrate that NC cannot overcome the inhibitory effect of actinomycin D on minus-strand transfer. Other experiments reveal that at actinomycin D concentrations which severely curtail minus-strand transfer, neither the synthesis of (−) SSDNA nor RNase H degradation of donor RNA is affected; however, the annealing of (−) SSDNA to acceptor RNA is significantly reduced. Thus, inhibition of the annealing reaction is responsible for actinomycin D-mediated inhibition of strand transfer. Since NC (but not reverse transcriptase) is required for efficient annealing, we conclude that actinomycin D inhibits minus-strand transfer by blocking the nucleic acid chaperone activity of NC. Our findings also suggest that actinomycin D, already approved for treatment of certain tumors, might be useful in combination therapy for AIDS.


2019 ◽  
Vol 17 (2) ◽  
pp. 105-114
Author(s):  
Pankaj Wadhwa ◽  
Priti Jain ◽  
Arpit Patel ◽  
Shantanu Shinde ◽  
Hemant R. Jadhav

<P>Background: A series of novel 3-(1,3-dioxoisoindolin-2-yl)-N-substituted phenyl benzamide derivatives was synthesized and tested in vitro against human immunodeficiency virus type-1 Integrase (HIV-1 IN). Methods: Out of the 18 analogues, six (compounds 16c, 16h, 16i, 16m, 16n and 16r) showed significant inhibition of strand transfer by HIV-1 integrase. For these six compounds. IC50 was below 5.0 µM. In silico docking studies revealed that the presence of 2-phenyl isoindoline-1,3-dione motif was essential as it was found to interact with active site magnesium. Results: To further confirm the results, cell-based HIV-1 and HIV-2 inhibitory assay was carried out. Conclusion: These compounds possess structural features not seen in previously reported HIV-1 integrase inhibitors and thus can help further optimization of anti-HIV-1 integrase activity.</P>


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