Biology subjects

Mercier, T.

Publications and source records attributed to Mercier, T..

3 recordsLinked to original sources

bioRxiv2026

Human prostaglandin reductases dearomatize and inactivate benzothiazinone antitubercular drugs

Macozinone (MCZ, PBTZ169) is a potent clinical stage benzothiazinone antitubercular agent that covalently inhibits the essential mycobacterial flavoenzyme DprE1. In some mammals, MCZ undergoes reductive dearomatization to H2MCZ, a Hydride Meisenheimer Complex, identified as the major circulating metabolite in humans. We demonstrate for the first time that the NADPH-dependent human prostaglandin reductases PTGR1 and PTGR2 catalyze MCZ dearomatization into H2MCZ, resulting in loss of antimycobacterial activity. This reaction represents a heretofore undescribed host-mediated metabolic inactivation pathway for a therapeutic agent. Although H2MCZ may constitute a transient reactive intermediate, ex vivo and cellular data indicate that it does not contribute to DprE1 inhibition in vivo. Pharmacological inhibition of PTGR1 and PTGR2 using diclofenac, indomethacin, dicumarol, or the selective inhibitor PTGR2-IN-1 suppresses H2MCZ formation and partially restores MCZ antimycobacterial activity in vitro. Together, our findings uncover a previously unrecognized noncanonical enzymatic mechanism of drug metabolism involving dearomatization in humans. Targeting prostaglandin reductases may represent a strategy to enhance benzothiazinone exposure and efficacy.

pharmacology and toxicology↗

bioRxiv2025

RNA-based communication in heterogeneous populations of cell mimics

RNA regulators offer a promising path for building complex, orthogonal circuits due to their low resource demands and design flexibility. In this study we explore their potential as signaling molecules in communication between synthetic cells. Specifically, we engineer populations of heterogenetic porous polymer cell mimics to produce, emit and receive two types of small synthetic RNA regulators. These RNAs are required to activate reporter expression at both the levels of transcription and translation. We distribute this AND gate circuit in receiver and two types of sender cell mimics to compare the distributed logic computation to the behavior of the circuit in well-mixed, bulk cell-free expression reactions. Analyzing different densities and spatial arrangements of senders and receivers, we reveal spatiotemporal gradients in RNA signals and identify configurations that increase specific activation. With small regulatory RNAs, the engineering toolbox for communication between synthetic cells expands to include a programmable class of signaling molecules. The rapid turnover of RNA suggests applications in establishing dynamic signaling gradients in communities of synthetic cells. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=110 SRC="FIGDIR/small/673985v2_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@3892b3org.highwire.dtl.DTLVardef@2751feorg.highwire.dtl.DTLVardef@1780922org.highwire.dtl.DTLVardef@19fc511_HPS_FORMAT_FIGEXP M_FIG C_FIG

synthetic biology↗

bioRxiv2020

HDLs extract lipophilic drugs from cells

High-density lipoproteins (HDLs) prevent cell death induced by a variety of cytotoxic drugs. The underlying mechanisms are however still poorly understood. Here we present evidence that HDLs efficiently protect cells against thapsigargin (a SERCA inhibitor) by extracting the drug from cells. Drug efflux could also be triggered to some extent by low-density lipoproteins (LDLs) and serum, which contains lipoproteins. HDLs did not reverse the non-lethal mild endoplasmic reticulum (ER) stress response induced by low thapsigargin concentrations or by SERCA knock-down but HDLs inhibited the toxic SERCA-independent effects mediated by high thapsigargin concentrations. HDLs were also found to extract other lipophilic compounds, such as the anti-diabetic drug glibenclamide. In contrast, hydrophilic substances (doxorubicin hydrochloride, rhodamine 123) were not extracted from cells by HDLs. This work shows that HDLs utilize their capacity of loading themselves with lipophilic compounds, akin to their ability to extract cellular cholesterol, to reduce the cell content of hydrophobic drugs. Silencing of the P-glycoprotein/ABCB1 transporter reduced the capacity of cells to load thapsigargin on HDLs. This work suggests that HDL-mediated cell efflux of toxic lipophilic xenobiotic is beneficial but also that HDL-mediated efflux can be detrimental to the therapeutic benefit of lipophilic drugs such as glibenclamide. Lipoprotein-mediated drug efflux should therefore be considered when evaluating drug efficacy.

cell biology↗