Insight from Linker Investigations: Discovery of a Novel Phenylbenzothiazole Necroptosis Inhibitor Targeting Receptor-Interacting Protein Kinase 1 (RIPK1) from a Phenoxybenzothiazole Compound with Dual RIPK1/3 Targeting Activity

Recognition of necroptosis: From molecular mechanisms to detection methods

Necroptosis is a crucial modality of programmed cell death characterized by distinct morphological and biochemical hallmarks, including cell membrane rupture, organelle swelling, cytoplasmic and nuclear disintegration, cellular contents leakage, and release of damage-associated molecular patterns (DAMPs), accompanied by the inflammatory responses. Studies have shown that necroptosis is involved in the etiology and evolution of a variety of pathologies including organ damage, inflammation disorders, and cancer. Despite its significance, the field of necroptosis research grapples with the challenge of non-standardized detection methodologies. In this review, we introduce the fundamental concepts and molecular mechanisms of necroptosis and critically appraise the principles, merits, and inherent limitations of current detection technologies. This endeavor seeks to establish a methodological framework for necroptosis detection, thereby propelling deeper insights into the research of cell necroptosis.

Design, synthesis, and structure-activity relationship studies of 6,7-dihydro-5H-pyrrolo[1,2-b][1,2,4]triazole derivatives as necroptosis inhibitors

The development of necroptosis inhibitors has emerged as a promising strategy to effectively mitigate necroptosis-related inflammatory diseases, neurodegenerative diseases, and cancers. In this paper, we reported a series of 6,7-dihydro-5H-pyrrolo[1,2-b][1,2,4]triazole derivatives as potent necroptosis inhibitors. The representative compound 26 displayed potent anti-necroptotic activity in both human and mouse cellular assays and exhibited potent inhibitory activity against receptor-interacting protein kinase 1 (RIPK1). In vivo pharmacokinetic studies were performed to determine the oral exposure of compound 26. Finally, molecular docking elucidated that compound 26 could effectively bind to the allosteric pocket of RIPK1 and serve as a type III inhibitor. Taken together, our findings highlighted that compound 26 represented a promising lead compound for future necroptosis inhibitor development.

RIPK1 inhibitors: A key to unlocking the potential of necroptosis in drug development

Within the field of medical science, there is a great deal of interest in investigating cell death pathways in the hopes of discovering new drugs. Over the past two decades, pharmacological research has focused on necroptosis, a cell death process that has just been discovered. Receptor-interacting protein kinase 1 (RIPK1), an essential regulator in the cell death receptor signalling pathway, has been shown to be involved in the regulation of important events, including necrosis, inflammation, and apoptosis. Therefore, researching necroptosis inhibitors offers novel ways to treat a variety of disorders that are not well-treated by the therapeutic medications now on the market. The research and medicinal potential of RIPK1 inhibitors, a promising class of drugs, are thoroughly examined in this study. The journey from the discovery of Necrostatin-1 (Nec-1) to the recent advancements in RIPK1 inhibitors is marked by significant progress, highlighting the integration of traditional medicinal chemistry approaches with modern technologies like high-throughput screening and DNA-encoded library technology. This review presents a thorough exploration of the development and therapeutic potential of RIPK1 inhibitors, a promising class of compounds. Simultaneously, this review highlights the complex roles of RIPK1 in various pathological conditions and discusses potential inhibitors discovered through diverse pathways, emphasizing their efficacy against multiple disease models, providing significant guidance for the expansion of knowledge about RIPK1 and its inhibitors to develop more selective, potent, and safe therapeutic agents.

From Hit to Lead: Structure-Based Optimization of Novel Selective Inhibitors of Receptor-Interacting Protein Kinase 1 (RIPK1) for the Treatment of Inflammatory Diseases

Receptor-interacting protein kinase 1 (RIPK1) is a key regulator of cellular necroptosis, which is considered as an important therapeutic target for necroptosis-related indications. Herein, we report the structural optimization and structure-activity relationship investigations of a series of eutectic 5-substituted-indole-3-carboxamide derivatives. The prioritized compound 10b exhibited low nanomolar IC50 values against RIPK1 and showed good kinase selectivity. Based on its eutectic structure, 10b occupied both the allosteric and ATP binding pockets of RIPK1, making it a potent dual-mode inhibitor of RIPK1. In vitro, 10b had a potent protective effect against necroptosis in cells. Compound 10b also provided robust protection in a TNFα-induced systemic inflammatory response syndrome (SIRS) model and imiquimod (IMQ)-induced psoriasis model. It also showed good pharmacokinetic properties and low toxicity. Overall, 10b is a promising lead compound for drug discovery targeting RIPK1 and warrants further study.