Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease (Mpro) autocatalytically releases itself out of the viral polyprotein to form a fully active mature dimer in a manner that is not fully understood. Here, we introduce several tools to help elucidate differences between cis (intramolecular) and trans (intermolecular) proteolytic processing and to evaluate inhibition of precursor Mpro. We found that many mutations at the P1 position of the N-terminal autoprocessing site do not block cis autoprocessing but do inhibit trans processing. Notably, substituting the WT glutamine at the P1 position with isoleucine retains Mpro in an unprocessed precursor form that can be purified and further studied. We also developed a cell-based reporter assay suitable for compound library screening and evaluation in HEK293T cells. This assay can detect both overall Mpro inhibition and the fraction of uncleaved precursor form of Mpro through separable fluorescent signals. We observed that inhibitory compounds preferentially block mature Mpro. Bofutrelvir and a novel compound designed in-house showed the lowest selectivity between precursor and mature Mpro, indicating that inhibition of both forms may be possible. Additionally, we observed positive modulation of precursor activity at low concentrations of inhibitors. Our findings help expand understanding of the SARS-CoV-2 viral life cycle and may facilitate development of strategies to target precursor form of Mpro for inhibition or premature activation of Mpro.
- MeSH
- antivirové látky * farmakologie chemie MeSH
- farmakoterapie COVID-19 MeSH
- HEK293 buňky MeSH
- inhibitory proteas farmakologie chemie MeSH
- koronavirové proteasy 3C * metabolismus antagonisté a inhibitory chemie genetika MeSH
- lidé MeSH
- mutace MeSH
- objevování léků * metody MeSH
- proteolýza MeSH
- SARS-CoV-2 * enzymologie účinky léků metabolismus genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The polymerase acidic (PA) subunit of the influenza virus, an endonuclease of the RNA-dependent RNA polymerase, represents a viable target for anti-influenza therapies, as evidenced by the efficacy of the FDA-approved drug Xofluza. A characteristic feature of endonuclease inhibitors is their ability to chelate Mg2+ or Mn2+ ions within the enzyme's catalytic site. Previously, our studies identified luteolin and its C-8-glucoside orientin as potent endonuclease inhibitors. This report details our subsequent investigation into the structural modifications of the phenyl moiety attached to the C-8 position of luteolin. The inhibitory potencies (IC50 values) quantified with AlphaScreen technology indicated that substituting the C-8 glucose moiety of orientin resulted in compounds with comparable inhibitory potency. From a series of eighteen compounds, acid 12 with 3-carboxylphenyl moiety at the C-8 position was the most potent inhibitor with nanomolar potency.
- MeSH
- antivirové látky * farmakologie chemická syntéza chemie MeSH
- endonukleasy * antagonisté a inhibitory metabolismus MeSH
- inhibitory enzymů * farmakologie chemická syntéza chemie MeSH
- luteolin * farmakologie chemická syntéza chemie MeSH
- molekulární struktura MeSH
- racionální návrh léčiv * MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Publikační typ
- časopisecké články MeSH
Intracellular protein aggregation causes proteotoxic stress, underlying highly debilitating neurodegenerative disorders in parallel with decreased proteasome activity. Nevertheless, under such stress conditions, the expression of proteasome subunits is upregulated by Nuclear Factor Erythroid 2-related factor 1 (NRF1), a transcription factor that is encoded by NFE2L1. Activating the NRF1 pathway could accordingly delay the onset of neurodegenerative and other disorders with impaired cell proteostasis. Here, we present a series of small-molecule compounds based on bis(phenylmethylen)cycloalkanones and their heterocyclic analogues, identified via targeted library screening, that can induce NRF1-dependent downstream events, such as proteasome synthesis, heat shock response, and autophagy, in both model cell lines and Caenorhabditis elegans strains. These compounds increase proteasome activity and decrease the size and number of protein aggregates without causing any cellular stress or inhibiting the ubiquitin-proteasome system (UPS). Therefore, our compounds represent a new promising therapeutic approach for various protein conformational diseases, including the most debilitating neurodegenerative diseases.
- MeSH
- aktivace transkripce účinky léků MeSH
- autofagie účinky léků MeSH
- Caenorhabditis elegans * účinky léků metabolismus MeSH
- faktor 1 související s NF-E2 metabolismus genetika MeSH
- knihovny malých molekul farmakologie MeSH
- lidé MeSH
- patologická konformace proteinů metabolismus farmakoterapie MeSH
- proteasomový endopeptidasový komplex * metabolismus MeSH
- proteinové agregáty * účinky léků MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Itaconate, an endogenous immunomodulator from the tricarboxylic acid (TCA) cycle, shows therapeutic effects in various disease models, but is highly polar with poor cellular permeability. We previously reported a novel, topical itaconate derivative, SCD-153, for the treatment of alopecia areata. Here, we present the discovery of orally available itaconate derivatives for systemic and skin disorders. Four sets of prodrugs were synthesized using pivaloyloxymethyl (POM), isopropyloxycarbonyloxymethyl (POC), (5-methyl-2-oxo-1,3-dioxol-4-yl) methyl (ODOL), and 3-(hexadecyloxy)propyl (HDP) pro-moieties pairing with itaconic acid (IA), 1-methyl itaconate (1-MI), and 4-methyl itaconate (4-MI). Among these, POC-based prodrugs (P2, P9, P13) showed favorable stability, permeability, and pharmacokinetics. Notably, P2 and P13 significantly inhibited Poly(I:C)/IFNγ-induced inflammatory cytokines in human epidermal keratinocytes. Oral studies demonstrated favorable pharmacokinetics releasing micromolar concentrations of IA or 4-MI from P2 and P13, respectively. These findings highlight the potential of prodrug strategies to enhance itaconate's cellular permeability and oral bioavailability, paving the way for clinical translation.
- MeSH
- aplikace orální MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- myši MeSH
- objevování léků MeSH
- prekurzory léčiv * chemie farmakologie chemická syntéza farmakokinetika MeSH
- sukcináty * chemie farmakologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
PURPOSE: Prostate-specific membrane antigen (PSMA) radioligand therapy is a promising treatment for metastatic castration-resistant prostate cancer (mCRPC). Several beta or alpha particle-emitting radionuclide-conjugated small molecules have shown efficacy in late-stage mCRPC and one, [[177Lu]Lu]Lu-PSMA-617, is FDA approved. In addition to tumor upregulation, PSMA is also expressed in kidneys and salivary glands where specific uptake can cause dose-limiting xerostomia and potential for nephrotoxicity. The PSMA inhibitor 2-(phosphonomethyl)pentanedioic acid (2-PMPA) can prevent kidney uptake in mice, but also blocks tumor uptake, precluding its clinical utility. Preferential delivery of 2-PMPA to non-malignant tissues could improve the therapeutic window of PSMA radioligand therapy. METHODS: A tris(isopropoxycarbonyloxymethyl) (TrisPOC) prodrug of 2-PMPA, JHU-2545, was synthesized to enhance 2-PMPA delivery to non-malignant tissues. Mouse pharmacokinetic experiments were conducted to compare JHU-2545-mediated delivery of 2-PMPA to plasma, kidney, salivary glands, and C4-2 prostate tumor xenograft. Imaging studies were conducted in rats and mice to measure uptake of PSMA PET tracers in kidney, salivary glands, and prostate tumor xenografts with and without JHU-2545 pre-treatment. RESULTS: JHU-2545 resulted in approximately 3- and 53-fold greater exposure of 2-PMPA in rodent salivary glands (18.0 ± 0.97 h*nmol/g) and kidneys (359 ± 4.16 h*nmol/g) versus prostate tumor xenograft (6.79 ± 0.19 h*nmol/g). JHU-2545 also blocked rodent kidneys and salivary glands uptake of the PSMA PET tracers [68Ga]Ga-PSMA-11 and [18 F]F-DCFPyL by up to 85% with little effect on tumor. CONCLUSIONS: JHU-2545 pre-treatment may enable greater cumulative administered doses of PSMA radioligand therapy, possibly improving safety and efficacy.
- MeSH
- antigeny povrchové * metabolismus MeSH
- glutamátkarboxypeptidasa II * metabolismus MeSH
- krysa rodu rattus MeSH
- ledviny * diagnostické zobrazování metabolismus MeSH
- lidé MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- organofosforové sloučeniny MeSH
- slinné žlázy * diagnostické zobrazování metabolismus účinky záření MeSH
- tkáňová distribuce MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The PB2 subunit of the influenza virus polymerase complex is essential for viral replication, primarily through a mechanism known as cap-snatching. In this process, PB2 binds to the 5' cap structure of host pre-mRNAs, enabling the viral polymerase to hijack the host transcriptional machinery. This binding facilitates the cleavage and integration of the capped RNA fragment into viral mRNA, thereby promoting efficient viral replication. Inhibiting the PB2-cap interaction is therefore crucial, as it directly disrupts the viral replication cycle. Consequently, targeting PB2 with specific inhibitors is a promising strategy for antiviral drug development against influenza. However, there are currently no available methods for the high-throughput screening of potential inhibitors. The development of new inhibitor screening methods of potential PB2 binders is the focus of this study. In this study, we present two novel methods, DIANA and AlphaScreen, for screening influenza PB2 cap-binding inhibitors and evaluate their effectiveness compared to the established differential scanning fluorimetry (DSF) technique. Using a diverse set of substrates and compounds based on the previously described PB2 binder pimodivir, we thoroughly assessed the capabilities of these new methods. Our findings demonstrate that both DIANA and AlphaScreen are highly effective for PB2 inhibitor screening, offering distinct advantages over traditional techniques such as isothermal titration calorimetry (ITC) and surface plasmon resonance (SPR). These advantages include improved scalability, reduced sample requirements, and the capacity for label-free detection. Notably, DIANA's ability to determine Ki values from a single-well measurement significantly enhances its practicality and efficiency in inhibitor screening. This research represents a significant step forward in the development of more efficient and scalable screening strategies, helping advance efforts in the discovery of antiviral drugs against influenza.
- MeSH
- antivirové látky * farmakologie chemie MeSH
- fluorometrie metody MeSH
- lidé MeSH
- piperidiny farmakologie MeSH
- pyridiny MeSH
- pyrimidiny MeSH
- pyrroly MeSH
- RNA čepičky metabolismus MeSH
- RNA-dependentní RNA-polymerasa antagonisté a inhibitory metabolismus MeSH
- rychlé screeningové testy * metody MeSH
- virové proteiny * antagonisté a inhibitory metabolismus MeSH
- virus chřipky A účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Rhomboid intramembrane serine proteases have been implicated in several pathologies, and emerge as attractive pharmacological target candidates. The most potent and selective rhomboid inhibitors available to date are peptidyl α-ketoamides, but their selectivity for diverse rhomboid proteases and strategies to modulate it in relevant contexts are poorly understood. This gap, together with the lack of suitable in vitro models, hinders ketoamide development for relevant eukaryotic rhomboid enzymes. Here we explore the structure-activity relationship principles of rhomboid inhibiting ketoamides by medicinal chemistry and enzymatic in vitro and in-cell assays with recombinant rhomboid proteases GlpG, human mitochondrial rhomboid PARL and human RHBDL2. We use X-ray crystallography in lipidic cubic phase to understand the binding mode of one of the best ketoamide inhibitors synthesized here containing a branched terminal substituent bound to GlpG. In addition, to extend the interpretation of the co-crystal structure, we use quantum mechanical calculations and quantify the relative importance of interactions along the inhibitor molecule. These combined experimental analyses implicates that more extensive exploration of chemical space at the prime side is unexpectedly powerful for the selectivity of rhomboid inhibiting ketoamides. Together with variations in the peptide sequence at the non-prime side, or its non-peptidic alternatives, this strategy enables targeted tailoring of potent and selective ketoamides towards diverse rhomboid proteases including disease-relevant ones such as PARL and RHBDL2.
- MeSH
- amidy * chemie farmakologie chemická syntéza MeSH
- inhibitory proteas farmakologie chemie chemická syntéza metabolismus MeSH
- krystalografie rentgenová MeSH
- lidé MeSH
- molekulární modely MeSH
- molekulární struktura MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The mitochondrial rhomboid protease PARL regulates mitophagy by balancing intramembrane proteolysis of PINK1 and PGAM5. It has been implicated in the pathogenesis of Parkinson's disease, but its investigation as a possible therapeutic target is challenging in this context because genetic deficiency of PARL may result in compensatory mechanisms. To address this problem, we undertook a hitherto unavailable chemical biology strategy. We developed potent PARL-targeting ketoamide inhibitors and investigated the effects of acute PARL suppression on the processing status of PINK1 intermediates and on Parkin activation. This approach revealed that PARL inhibition leads to a robust activation of the PINK1/Parkin pathway without major secondary effects on mitochondrial properties, which demonstrates that the pharmacological blockage of PARL to boost PINK1/Parkin-dependent mitophagy is a feasible approach to examine novel therapeutic strategies for Parkinson's disease. More generally, this study showcases the power of ketoamide inhibitors for cell biological studies of rhomboid proteases.
- MeSH
- endopeptidasy MeSH
- lidé MeSH
- metaloproteasy genetika metabolismus MeSH
- mitochondriální proteiny metabolismus MeSH
- mitofagie MeSH
- Parkinsonova nemoc * farmakoterapie MeSH
- proteasy * MeSH
- proteinkinasy metabolismus MeSH
- ubikvitinligasy metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Alopecia areata is a chronic hair loss disorder that involves autoimmune disruption of hair follicles by CD8+ T cells. Most patients present with patchy hair loss on the scalp that improves spontaneously or with topical and intralesional steroids, topical minoxidil, or topical immunotherapy. However, recurrence of hair loss is common, and patients with extensive disease may require treatment with oral corticosteroids or oral Janus kinase (JAK) inhibitors, both of which may cause systemic toxicities with long-term use. Itaconate is an endogenous molecule synthesized in macrophages that exerts anti-inflammatory effects. To investigate the use of itaconate derivatives for treating alopecia areata, we designed a prodrug of 4-methyl itaconate (4-MI), termed SCD-153, with increased lipophilicity compared to 4-MI (CLogP 1.159 vs. 0.1442) to enhance skin and cell penetration. Topical SCD-153 formed 4-MI upon penetrating the stratum corneum in C57BL/6 mice and showed low systemic absorption. When added to human epidermal keratinocytes stimulated with polyinosinic-polycytidylic acid (poly I:C) or interferon (IFN)γ, SCD-153 significantly attenuated poly I:C-induced interleukin (IL)-6, Toll-like receptor 3, IL-1β, and IFNβ expression, as well as IFNγ-induced IL-6 expression. Topical application of SCD-153 to C57BL/6 mice in the resting (telogen) phase of the hair cycle induced significant hair growth that was statistically superior to vehicle (dimethyl sulfoxide), the less cell-permeable itaconate analogues 4-MI and dimethyl itaconate, and the JAK inhibitor tofacitinib. Our results suggest that SCD-153 is a promising topical candidate for treating alopecia areata.
- Publikační typ
- časopisecké články MeSH
The development of highly active and selective enzyme inhibitors is one of the priorities of medicinal chemistry. Typically, various high-throughput screening methods are used to find lead compounds from a large pool of synthetic compounds, and these are further elaborated and structurally refined to achieve the desired properties. In an effort to streamline this complex and laborious process, new selection strategies based on different principles have recently emerged as an alternative. Herein, we compare three such selection strategies with the aim of identifying potent and selective inhibitors of human carbonic anhydrase II. All three approaches, in situ click chemistry, phage-display libraries and synthetic peptide libraries, led to the identification of more potent inhibitors when compared to the parent compounds. In addition, one of the inhibitor-peptide conjugates identified from the phage libraries showed greater than 100-fold selectivity for the enzyme isoform used for the compound selection. In an effort to rationalize the binding properties of the conjugates, we performed detailed crystallographic and NMR structural analysis, which revealed the structural basis of the compound affinity towards the enzyme and led to the identification of a novel exosite that could be utilized in the development of isoform specific inhibitors.
- Publikační typ
- časopisecké články MeSH
