The Discovery of
GSK3227634: A Potent Inhaled Inhibitor
of the KEAP1/NRF2 Protein–Protein Interaction for the Treatment
of Chronic Obstructive Pulmonary Disease
Aug 2026· Journal of Medicinal Chemistry· 0 citations· 39 references
Abstract
KEAP1 is the key regulator of the NRF2-mediated cytoprotective response and a target for pathologies involving oxidative stress. Compounds that covalently modify KEAP1 to activate NRF2 are clinically validated; however, their chemical reactivity may drive increased off–target activity. A more selective approach involves inhibition of the KEAP1-NRF2 protein–protein interaction as exemplified by our previous bis-aryl lead KI-696 (4). We now describe the lead optimization of the bis-aryl series that focused on increasing the population of the bioactive conformation of the free ligand to drive potency while optimizing overall physicochemical properties. This resulted in the discovery of GSK3227634 (5), an ultrahigh-affinity noncovalent inhibitor of KEAP1-NRF2 (surface plasmon resonance pKd = 10.9) and the first NRF2 activator to demonstrate target engagement and efficacy in preclinical models of oxidative stress via direct delivery to the lung. Compound 5 therefore represents a novel potential agent to treat lung diseases involving oxidative stress, such as chronic obstructive pulmonary disease.
This study investigates the synergistic therapeutic potential of Rivastigmine (RVG) and Epigallocatechin (EGC) in Alzheimer’s disease (AD), a multifactorial neurodegenerative disorder characterized by neuroinflammation, oxidative stress, and dysregulated signaling pathways. Conventional therapies primarily provide symptomatic relief and target limited pathways, highlighting the need for multi-target strategies with improved efficacy and safety. An integrated in silico approach combining pharmacokinetic evaluation, network pharmacology, molecular docking, and molecular dynamics simulations is used to determine the synergistic potential of RVG and EGC. Pharmacokinetic analysis indicates favorable drug-likeness and acceptable ADME/Tox profiles for both compounds. Network pharmacology identified 146 overlapping targets associated with AD, highlighting key hub genes including NFKB1, MAPK1, STAT1, PRKACA, GRB2, LYN, and PTPN11, which are involved in neuroinflammation, synaptic signaling, and neuronal survival. Functional enrichment analysis indicated significant involvement of MAPK/ERK signaling and immune-regulatory pathways. Importantly, the PD-1/PD-L1 signaling pathway is identified as a novel mechanism connecting neuroimmune modulation with intracellular kinase-driven neurodegeneration. Molecular docking studies showed strong binding affinities of RVG and EGC toward key AD-related targets, particularly MAPK1, supported by stable hydrogen bonding and interaction profiles. Molecular dynamics simulations confirmed stable protein-ligand interactions, with EGC contributing structural stability and RVG exhibiting adaptive flexibility within the binding pocket. These results suggest that the RVG-EGC combination exhibits synergistic potential by simultaneously modulating neuroinflammatory, oxidative stress, and kinase-mediated signaling pathways. The integration of PD-1/PD-L1 and MAPK/ERK signaling provides a novel mechanistic pathway for multi-target therapeutic intervention in AD.
Bhaswati Das, M. S. Umashankar· Scientia Pharmaceutica· 0 citations
STAT6 is a transcription factor downstream of IL-4 and IL-13 signaling that acts as a key driver of type 2 inflammation, which is associated with atopic dermatitis and asthma. Inhibition of the IL-4/IL-13 pathway is clinically validated for treatment of allergic diseases. Our aim is to develop an oral small molecule that selectively inhibits activation of STAT6 for the treatment of allergic diseases.
Binding affinity and mechanism of action were determined using SPR and a nuclear translocation assay, respectively. Compound potency against human STAT6 was assessed in PBMC by measuring phosphorylated STAT6. Selectivity was examined utilizing STAT SH2 scan, KINOMEscan, and cellular assays for STATs 1-5. Inhibition of Th2 biomarkers, TARC and periostin, and cellular proliferation were assessed in cellular assays. Ex vivo target engagement was measured in mouse whole blood.
EPS-3903 is an orally bioavailable allosteric inhibitor of STAT6 with strong binding affinity (Kd = 0.42 nM) that exhibited robust selectivity against other STAT family members, as well as a broad kinase panel. EPS-3903 suppressed STAT6 nuclear translocation in the human lung cell line A549 with an IC50 of 14 nM. In PBMC, EPS-3903 inhibited IL4-induced STAT6 phosphorylation and TARC production with IC50s of 5 and 11 nM, respectively. EPS-3903 potently prevented IL-13-induced periostin production in primary bronchial cells and STAT6-mediated proliferation in human TF-1 erythroblast cells with IC50s of 3.3 and 7.5 nM, respectively. In mouse whole blood, EPS-3903 suppressed pSTAT6 by > 90% for 24 h.
EPS-3903 is a potent and selective allosteric inhibitor of STAT6 and demonstrated effectiveness in preventing STAT6 activation and downstream Th2 biomarker production. EPS-3903 suppressed STAT6 activation in vivo by > 90% for 24 h. EPS-3903 may offer an oral therapeutic potential for treating allergic diseases including asthma and atopic dermatitis.
n/a
Immediate Hypersensitivity, Asthma, and Allergic Responses (HYP)
K. Garlick, J. Sweeney, M. Chau et al.· Journal of Immunology· 0 citations
This study identifies structurally tractable TQ analogs with improved predicted potency and establishes a robust computational framework for neuroprotective discovery as redox‐modulating agents in ALS.
Jabir C Nalicho, P. Mabeyo, Andrew S. Paluch et al.· ChemistryOpen· 0 citations
Chronic kidney disease (CKD) remains a major global health burden, and renal fibrosis is a key pathological driver of CKD progression. Homeodomain-interacting protein kinase 2 (HIPK2) has emerged as a potential therapeutic target because of its involvement in TGF-β/Smad3-mediated fibrotic signaling and NF-κB-driven inflammatory responses. In this study, a series of 2, 4-disubstituted pyrimidine derivatives were designed and synthesized as HIPK2 inhibitors. Among them, A6 (AF-1) and B11 (AF-2) exhibited potent HIPK2 inhibitory activity, with IC50 values of 0.36 and 0.56 μM, respectively, together with improved subtype selectivity over HIPK1 and HIPK3. Cellular thermal shift assays showed that AF-1 and AF-2 increased the thermal stability of endogenous HIPK2 in both NRK-49F and HK-2 cells, supporting intracellular target engagement. In TGF-β1-stimulated NRK-49F cells and HK-2 cells, both compounds reduced the expression of fibrosis-related markers, including fibronectin, collagen I, and α-SMA. AF-1 and AF-2 also inhibited the proliferation and migration of NRK-49F cells and attenuated TNF-α-induced NF-κB activation in HK-2 cells. In a 0.2% adenine-diet-induced mouse model of CKD, AF-1 and AF-2 alleviated renal tubular injury and collagen deposition, demonstrating significant renoprotective and antifibrotic effects in vivo. Collectively, AF-1 and AF-2 represent antifibrotic candidates with a new chemical scaffold, submicromolar HIPK2 inhibitory activity, and improved subtype selectivity within the HIPK family. Although further optimization is required to improve their pharmacokinetic and drug-like properties, these findings provide a new structural basis for the development of HIPK2 inhibitors with enhanced HIPK family selectivity for the treatment of CKD-associated renal fibrosis.
Xinlan Hu, Hanyi Ouyang, Chunyu Feng et al.· European journal of medicina...· 0 citations
Background Triptolide demonstrates potent antiarthritic effects in rheumatoid arthritis (RA), although its complete mechanism is not fully elucidated. This study aimed to systematically identify its core targets and regulatory pathways by integrating network pharmacology, molecular docking, and experimental validation. Methods Potential targets of triptolide and RA‐associated genes were sourced from public databases. Network module analysis identified key targets, the binding affinity of which to triptolide was subsequently assessed by molecular docking, molecular dynamics (MD) simulations, and drug affinity responsive target stability (DARTS) assay. The functional effects of triptolide on RA fibroblast‐like synoviocytes (RA‐FLS) behavior, joint inflammation, and bone erosion were further investigated using in vitro cellular assays and a collagen‐induced arthritis (CIA) mouse model. Results Our analysis identified 73 candidate targets for triptolide against RA, which were primarily enriched in biological processes such as transcription factor activity and inflammatory response. Protein–protein interaction (PPI) network analysis highlighted a core module of five genes, among which STAT3 and its upstream regulator NR1D1 were selected for subsequent investigation. Molecular docking, MD simulation, and DARTS assay confirmed the high‐affinity and direct binding of triptolide to NR1D1. In vitro, triptolide effectively suppressed RA‐FLS migration and invasion, upregulated NR1D1, and inhibited JAK1/STAT3 signaling. In vivo, triptolide administration ameliorated arthritis severity and reduced bone erosion in CIA mice, as well as modulation of the NR1D1/STAT3 axis. Conclusion This study demonstrates that triptolide alleviates RA through NR1D1‐mediated inhibition of JAK1/STAT3 signaling. Our findings elucidate a novel molecular mechanism for triptolide’s antiarthritic effects, thereby revealing the NR1D1/JAK1/STAT3 axis as a potential therapeutic target for RA.
Conglin Ren, Mingshuang Li, Caijian He et al.· Mediators of Inflammation· 0 citations
Alzheimer’s disease (AD) is a complex neurodegenerative disorder characterized by the accumulation and aggregation of β-amyloid (Aβ) and chronic neuroinflammation mediated by the receptor for advanced glycation end products (RAGE). Current therapeutic candidates targeting RAGE signaling or Aβ aggregation continue to face challenges, including off-target toxicity, poor blood-brain barrier (BBB) penetration, and limited multi-target efficacy.
Naringenin (NAR), a naturally occurring flavanone polyphenol prioritized through structure-based virtual screening and preliminary biological evaluation, was selected for further mechanistic investigation as a potential dual-target modulator of RAGE-associated inflammatory signaling and Aβ42 fibrillization.
Molecular docking analyses showed that NAR interacts with the RAGE interface (PDB: 6XQ3) via π-cation interactions with ARG_98 and LYS_110 (docking score: −5.072 kcal/mol). At the Aβ fibril (PDB: 2MXU), NAR showed a superior docking score than ALZ-801 (valiltramiprosate), involving hydrogen bonding and π–π stacking with HIS_A14 (docking score: −8.098 kcal/mol). 100 ns molecular dynamics simulations supported the stability of these binding modes, with RMSD and RMSF values within acceptable ranges. MM-GBSA rescoring indicated competitive predicted binding free energies (ΔGBind: −30.260 kcal/mol at RAGE; −220.162 kcal/mol at the fibril, compared to ALZ- 801’s −214.482 kcal/mol), influenced by electrostatic and hydrophobic interactions. Per-residue energy decomposition indicated PHE_20 (−9.10 kcal/ mol) as the dominant hotspot residue, alongside ARG_98 (−4.71 kcal/mol) and LYS_52 (−3.96 kcal/mol) as key RAGE anchors.
In silico
ADMET profiling suggested favorable predicted BBB accessibility (score: 0.001), Caco-2 permeability, Lipinski compliance, and a more favorable predicted cardiac safety profile (hERG: 0.145) relative to V6Y. Experimentally, NAR reduced Aβ42-induced NF-κB activation in RAGE-positive C6 cells, protected SH-SY5Y neurons from Aβ42 toxicity, and inhibited Aβ42 fibrillization
in vitro
, producing non-seeding aggregates consistent with impaired fibril formation, and attenuated rotenone-induced α-synuclein-associated cellular stress.
Collectively, these findings support further investigation of NAR as a mechanistically plausible multi-target candidate for protein aggregation and RAGE-associated inflammatory signaling in neurodegenerative disease models.
Inderjeet Bhogal, I. Frydrych, Ajay Modi et al.· Frontiers in Pharmacology· 0 citations
