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Cell Research Dec 2023Members of the solute carrier organic anion transporting polypeptide (OATPs) family function as transporters for a large variety of amphipathic organic anions including...
Members of the solute carrier organic anion transporting polypeptide (OATPs) family function as transporters for a large variety of amphipathic organic anions including endogenous metabolites and clinical drugs, such as bile salts, steroids, thyroid hormones, statins, antibiotics, antivirals, and anticancer drugs. OATP1B1 plays a vital role in transporting such substances into the liver for hepatic clearance. FDA and EMA recommend conducting in vitro testing of drug-drug interactions (DDIs) involving OATP1B1. However, the structure and working mechanism of OATPs still remains elusive. In this study, we determined cryo-EM structures of human OATP1B1 bound with representative endogenous metabolites (bilirubin and estrone-3-sulfate), a clinical drug (simeprevir), and a fluorescent indicator (2',7'-dichlorofluorescein), in both outward- and inward-open states. These structures reveal major and minor substrate binding pockets and conformational changes during transport. In combination with mutagenesis studies and molecular dynamics simulations, our work comprehensively elucidates the transport mechanism of OATP1B1 and provides the structural basis for DDI predictions involving OATP1B1, which will greatly promote our understanding of OATPs.
Topics: Humans; Biological Transport; Cryoelectron Microscopy; Liver; Liver-Specific Organic Anion Transporter 1; Organic Anion Transporters; Thyroid Hormones
PubMed: 37674011
DOI: 10.1038/s41422-023-00870-8 -
Zhong Nan Da Xue Xue Bao. Yi Xue Ban =... Jun 2023() is a Gram-positive opportunistic pathogen that often causes hospital infections. With the abuse of antibiotics, the resistance of gradually increases, and drug...
OBJECTIVES
() is a Gram-positive opportunistic pathogen that often causes hospital infections. With the abuse of antibiotics, the resistance of gradually increases, and drug repurposing has become a research hotspot in the treating of refractory drug-resistant bacterial infections. This study aims to study the antimicrobial and antibiofilm effects of simeprevir, an antiviral hepatitis drug, on in vitro.
METHODS
The micro-dilution assay was used to determine the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of simeprevir against . Crystal violet staining assay was used to detect the biofilm inhibitory effect of simeprevir. The antimicrobial activity of simeprevir against and its biofilm were explored by SYTO9/PI fluorescent staining. The combined effect between simeprevir and gentamycin was assessed by checkerboard assay and was confirmed by time-inhibition assay.
RESULTS
Simeprevir showed significant antimicrobial effects against type strains and clinical isolates with the MIC and MBC at 2-16 μg/mL and 4-32 μg/mL, respectively. The antimicrobial effects of simeprevir were confirmed by SYTO9/PI staining. Simeprevir at MIC could significantly inhibit and break the biofilm on cover slides. Similarly, simeprevir also significantly inhibit the biofilm formation on the surface of urine catheters either in TSB [from (0.700±0.020) to (0.050±0.004)] (=54.03, <0.001), or horse serum [from (1.00±0.02) to (0.13±0.01)] (=82.78, <0.001). Synergistic antimicrobial effect was found between simeprevir and gentamycin against with the fractional inhibitory concentration index of 0.5.
CONCLUSIONS
Simeprevir shows antimicrobial effect and anti-biofilm activities against
Topics: Humans; Simeprevir; Antiviral Agents; Anti-Bacterial Agents; Cross Infection; Gentamicins
PubMed: 37587072
DOI: 10.11817/j.issn.1672-7347.2023.220644 -
ACS Central Science May 2021The outbreak of coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a global threat to human health....
The outbreak of coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a global threat to human health. Using a multidisciplinary approach, we identified and validated the hepatitis C virus (HCV) protease inhibitor simeprevir as an especially promising repurposable drug for treating COVID-19. Simeprevir potently reduces SARS-CoV-2 viral load by multiple orders of magnitude and synergizes with remdesivir . Mechanistically, we showed that simeprevir not only inhibits the main protease (M) and unexpectedly the RNA-dependent RNA polymerase (RdRp) but also modulates host immune responses. Our results thus reveal the possible anti-SARS-CoV-2 mechanism of simeprevir and highlight the translational potential of optimizing simeprevir as a therapeutic agent for managing COVID-19 and future outbreaks of CoV.
PubMed: 34075346
DOI: 10.1021/acscentsci.0c01186 -
CPT: Pharmacometrics & Systems... Oct 2023The orally available anti-hepatitis C virus (HCV) drug simeprevir exhibits nonlinear pharmacokinetics at the clinical doses due to saturation of cytochrome P450 (CYP)...
The orally available anti-hepatitis C virus (HCV) drug simeprevir exhibits nonlinear pharmacokinetics at the clinical doses due to saturation of cytochrome P450 (CYP) 3A4 metabolism and organic anion transporting peptide (OATP) 1B mediated hepatic uptake. Additionally, simeprevir increases exposures of concomitant drugs by CYP3A4 and OATP1B inhibition. The objective of this study was to develop physiologically-based pharmacokinetic (PBPK) models that could describe drug-drug interactions (DDIs) of simeprevir with concomitant drugs via CYP3A4 and OATP1B inhibition, and also to capture the effects on coproporphyrin-I (CP-I), an endogenous biomarker of OATP1B. PBPK modeling estimated unbound simeprevir inhibitory constant (K ) of 2.89 μM against CYP3A4 in the DDI results between simeprevir and midazolam in healthy volunteers. Then, we analyzed the DDIs between simeprevir and atorvastatin, a dual substrate of CYP3A4 and OATP1B, in healthy volunteers, and unbound K against OATP1B was estimated to be 0.00347 μM. Finally, we analyzed the increase in the blood level of CP-I by simeprevir to verify the K . Because CP-I was measured in subjects with HCV with various hepatic fibrosis state, Monte Carlo simulation was performed to involve the decreases in expression levels of hepatic CYP3A4 and OATP1B and their interindividual variabilities. The PBPK modeling coupled with Monte Carlo simulation using the K value obtained from atorvastatin study reasonably recovered the observed relationship between CP-I and simeprevir blood levels. In conclusion, the simeprevir PBPK model developed in this study can quantitatively describe the increase in exposures of concomitant drugs and an endogenous biomarker via inhibition of CYP3A4 and OATP1B.
Topics: Humans; Simeprevir; Cytochrome P-450 CYP3A; Atorvastatin; Biomarkers; Drug Interactions; Hepatitis C; Models, Biological
PubMed: 37667529
DOI: 10.1002/psp4.13023 -
Redox Biology Jul 2023Selenoprotein glutathione peroxidases (GPX), like ubiquitously expressed GPX1 and the ferroptosis modulator GPX4, enact antioxidant activities by reducing hydroperoxides...
Selenoprotein glutathione peroxidases (GPX), like ubiquitously expressed GPX1 and the ferroptosis modulator GPX4, enact antioxidant activities by reducing hydroperoxides using glutathione. Overexpression of these enzymes is common in cancer and can be associated with the development of resistance to chemotherapy. GPX1 and GPX4 inhibitors have thus shown promise as anti-cancer agents, and targeting other GPX isoforms may prove equally beneficial. Existing inhibitors are often promiscuous, or modulate GPXs only indirectly, so novel direct inhibitors identified through screening against GPX1 and GPX4 could be valuable. Here, we developed optimized glutathione reductase (GR)-coupled GPX assays for the biochemical high-throughput screen (HTS) of almost 12,000 compounds with proposed mechanisms of action. Initial hits were triaged using a GR counter-screen, assessed for isoform specificity against an additional GPX isoform, GPX2, and were assessed for general selenocysteine-targeting activity using a thioredoxin reductase (TXNRD1) assay. Importantly, 70% of the GPX1 inhibitors identified in the primary screen, including several cephalosporin antibiotics, were found to also inhibit TXNRD1, while auranofin, previously known as a TXNRD1 inhibitor, also inhibited GPX1 (but not GPX4). Additionally, every GPX1 inhibitor identified (including omapatrilat, tenatoprazole, cefoxitin and ceftibuten) showed similar inhibitory activity against GPX2. Some compounds inhibiting GPX4 but not GPX1 or GPX2, also inhibited TXNRD1 (26%). Compounds only inhibiting GPX4 included pranlukast sodium hydrate, lusutrombopag, brilanestrant, simeprevir, grazoprevir (MK-5172), paritaprevir, navitoclax, venetoclax and VU0661013. Two compounds (metamizole sodium and isoniazid sodium methanesulfate) inhibited all three GPXs but not TXNRD1, while 2,3-dimercaptopropanesulfonate, PI4KIII beta inhibitor 3, SCE-2174 and cefotetan sodium inhibited all tested selenoproteins (but not GR). The detected overlaps in chemical space suggest that the counter screens introduced here should be imperative for identification of specific GPX inhibitors. With this approach, we could indeed identify novel GPX1/GPX2- or GPX4-specific inhibitors, thus presenting a validated pipeline for future identification of specific selenoprotein-targeting agents. Our study also identified GPX1/GPX2, GPX4 and/or TXNRD1 as targets for several previously developed pharmacologically active compounds.
Topics: Humans; Glutathione; Glutathione Peroxidase GPX1; Neoplasms; Selenoproteins
PubMed: 37244126
DOI: 10.1016/j.redox.2023.102719