Discovery of 4H-Chromen-4-one Derivatives as a New Class of Selective Rho Kinase (ROCK) Inhibitors, which Showed Potent Activity in ex Vivo Diabetic Retinopathy Models

Computational discovery of novel PI3KC2α inhibitors using structure-based pharmacophore modeling, machine learning and molecular dynamic simulation

PI3KC2α is a lipid kinase associated with cancer metastasis and thrombosis. In this study, we present a novel computational workflow integrating structure-based pharmacophore modeling, machine learning (ML), and molecular dynamics (MD) simulations to discover new PI3KC2α inhibitors. Key innovations include the generation of diverse pharmacophores from both crystallographic and docking-derived complexes, coupled with data augmentation via ligand conformational sampling to enhance ML robustness. The optimal model, developed using XGBoost with genetic function algorithm (GFA) and Shapley additive explanations (SHAP), identified four critical pharmacophores and three descriptors governing bioactivity. Virtual screening of the NCI database using these pharmacophores yielded three hits, with H_1 (NCI: 725847) demonstrating MD-derived binding stability and affinity comparable to the potent inhibitor PITCOIN1 (IC50 = 95 nM). This study represents the first application of a conformation-augmented ML framework to PI3KC2α inhibition, offering a blueprint for targeting underexplored kinases with limited structural data.

Design, Synthesis, and Evaluation of Novel ROCK Inhibitors for Glaucoma Treatment: Insights into In Vitro and In Vivo Efficacy and Safety

The inhibition of Rho-associated coiled-coil kinase (ROCK) has emerged as a promising strategy for reducing intraocular pressure (IOP) and treating glaucoma. Here, we report the synthesis and evaluation of novel ROCK inhibitors, D25 and R3, which were designed to optimize selectivity, efficacy, and ocular bioavailability. D25 potently inhibited ROCK1/2 with IC50 values of 47.2 nM and 33.8 nM, respectively, surpassing Netarsudil. Compound R3 had weaker ROCK inhibition but demonstrated favorable lipophilicity (logP) and good selectivity to ROCKs, which enhances its potential and safety for ocular delivery. In human trabecular meshwork (HTM) cells, R3 showed lower cytotoxicity than Netarsudil and effectively mitigated oxidative damage, enhanced cellular integrity, and reduced inflammatory cytokine secretion. In rabbit models, D25 significantly lowered IOP, outperforming (S)-Netarsudil. R3 exhibited weaker IOP-lowering efficacy but better selectivity. D25 is a promising glaucoma treatment candidate, with R3 as a safer alternative for further optimization.

Recent advances in the development of Rho kinase inhibitors (2015-2021)

Rho-associated coiled-coil kinases (ROCKs) are key downstream effectors of small GTPases. ROCK plays a central role in diverse cellular events with accumulating evidence supporting the concept that ROCK is important in tumor development and progression. Numerous ROCK inhibitors have been investigated for their therapeutic potential in the treatment of cancers. In this article, we review recent research progress on ROCK inhibitors, especially those with potential for the treatment of cancers, reported in the literature from 2015 to 2021. Most ROCK inhibitors show potent in vitro and in vivo antitumor activities and have potential in the treatment of cancers.

Application and Study of ROCK Inhibitors in Pulmonary Fibrosis: Recent Developments and Future Perspectives

Rho-associated coiled-coil-containing kinases (ROCKs), serine/threonine protein kinases, were initially identified as downstream targets of the small GTP-binding protein Rho. Pulmonary fibrosis (PF) is a lethal disease with limited therapeutic options and a particularly poor prognosis. Interestingly, ROCK activation has been demonstrated in PF patients and in animal PF models, making it a promising target for PF treatment. Many ROCK inhibitors have been discovered, and four of these have been approved for clinical use; however, no ROCK inhibitors are approved for the treatment of PF patients. In this article, we describe ROCK signaling pathways and the structure-activity relationship, potency, selectivity, binding modes, pharmacokinetics (PKs), biological functions, and recently reported inhibitors of ROCKs in the context of PF. We will also focus our attention on the challenges to be addressed when targeting ROCKs and discuss the strategy of ROCK inhibitor use in the treatment of PF.

Synthesis and structure-activity relationship study of new biaryl amide derivatives and their inhibitory effects against hepatitis C virus

A series of novel biaryl amide derivatives were synthesized and evaluated for anti-HCV virus activity. Some significant SARs were uncovered. The intensive structural modifications led to fifteen novel compounds with more potent inhibitory activity compared to the hit compounds IMB 26 and IMB1f. Among them, compound 80 was the most active, with EC₅₀ values almost equivalent to the clinical drug telaprevir (EC₅₀ = 15 nM). Furthermore, it also had a good safety and in vitro and oral pharmacokinetic (oral bioavailability in rats: 34%) profile, suggesting a highly drug-like nature. Compound 80represents a more promising scaffold for anti-HCV virus activity for further study.

Discovery of 3,4-dihydrobenzo[f][1,4]oxazepin-5(2H)-one derivatives as a new class of ROCK inhibitors for the treatment of glaucoma

The Rho-associated protein kinases (ROCKs) are associated with the pathology of glaucoma and discovery of ROCK inhibitors has attracted much attention in recent years. Herein, we report a series of 3,4-dihydrobenzo[f][1,4]oxazepin-5(2H)-one derivatives as a new class of ROCK inhibitors. Structure-activity relationship studies led to the discovery of compound 12b, which showed potent activities against ROCK I and ROCK Ⅱ with IC₅₀ values of 93 nM and 3 nM, respectively. 12b also displayed considerable selectivity for ROCKs. The mean IOP-lowering effect of 12b in an ocular normotensive model was 34.3%, and no obvious hyperemia was observed. Overall, this study provides a good starting point for ROCK-targeting drug discovery against glaucoma.

Small-Molecule Kinase Inhibitors for the Treatment of Nononcologic Diseases

Great successes have been achieved in developing small-molecule kinase inhibitors as anticancer therapeutic agents. However, kinase deregulation plays essential roles not only in cancer but also in almost all major disease areas. Accumulating evidence has revealed that kinases are promising drug targets for different diseases, including cancer, autoimmune diseases, inflammatory diseases, cardiovascular diseases, central nervous system disorders, viral infections, and malaria. Indeed, the first small-molecule kinase inhibitor for treatment of a nononcologic disease was approved in 2011 by the U.S. FDA. To date, 10 such inhibitors have been approved, and more are in clinical trials for applications other than cancer. This Perspective discusses a number of kinases and their small-molecule inhibitors for the treatment of diseases in nononcologic therapeutic fields. The opportunities and challenges in developing such inhibitors are also highlighted.