Development of a Covalent Inhibitor of c-Jun N-Terminal Protein Kinase (JNK) 2/3 with Selectivity over JNK1

A "Ligand First" Approach toward Selective, Covalent JNK2/3 Inhibitors

All JNK isoforms play a specific role in various diseases. The role of the JNK2 isoform has so far received little attention compared to its JNK1 and JNK3 counterparts with JNK3 being a potential target for neurodegenerative diseases and an inhibitor with JNK1 bias being currently investigated in clinical trials. Using an iterative, structure-guided optimization approach starting from a reported reversible binding aminopyrazole-derived scaffold, novel highly potent JNK2/3 selective inhibitors were generated ("ligand-first approach"). These reversible inhibitors were further transformed to covalent inhibitors by attaching an electrophilic warhead moiety, able to address a conserved cysteine side chain present in JNKs. Reversible and covalent inhibitors presented in this study show high JNK2/3 isoform selectivity and activity in cells. The covalently acting lead compound 56d shows good kinetic data with a kinact/KI (JNK2) = 38,200 M-1 s-1 as well as cellular isoform selectivity and a clean kinome profile.

Design, synthesis, and biological evaluation of Ponatinib-based N-Phenylpyrimidine-2-amine derivatives as novel fibroblast growth factor receptor 4 (FGFR4) selective inhibitors

Fibroblast growth factor receptor 4 (FGFR4) has been proven to be a promising target for FGFR-driven HCC therapy. Great efforts have been devoted to the discovery of FGFR4 inhibitors. In this article, a new class of Ponatinib-based N-phenylpyridine-2-amine derivatives was designed and synthesized as covalent and irreversible FGFR4 selective inhibitors through a rational drug design strategy. The representative compound 10f displayed significant FGFR4 inhibition and reasonable selectivity. Meanwhile, compound 10f strongly suppressed the proliferation of FGFR4 dependent HCC cells both in vitro and in vivo by inhibiting the FGFR4 signaling pathway. Moreover, the irreversible binding to Cys552 in FGFR4 of compound 10f was also characterized by LC-MS/MS. These results provide evidence of 10f as a potential lead compound targeting FGFR4 for anti-HCC agent development.

A focus on c-Jun-N-terminal kinase signaling in sepsis-associated multiple organ dysfunction: Mechanisms and therapeutic strategies

Sepsis is a life-threatening condition characterized by a widespread inflammatory response to infection, inevitably leading to multiple organ dysfunctions. Extensive research, both in vivo and in vitro, has revealed key factors contributing to sepsis, such as apoptosis, inflammation, cytokine release, oxidative stress, and systemic stress. The changes observed during sepsis-induced conditions are mainly attributed to altered signal transduction pathways, which play a critical role in cell proliferation, migration, and apoptosis. C-Jun N-terminal kinases, JNKs, and serine/threonine protein kinases in the mitogen-activated super family have gained considerable interest for their contribution to cellular events under sepsis conditions. JNK1 and JNK2 are present in various tissues like the lungs, liver, and intestine, while JNK3 is found in neurons. The JNK pathway plays a crucial role in the signal transduction of cytokines related to sepsis development, notably TNF-α and IL-1β. Activated JNK leads to apoptosis, causing tissue damage and organ dysfunction. Further, JNK activation is significant in several inflammatory conditions. Pharmacologically inhibiting JNK has been shown to prevent sepsis-associated damage across multiple organs, including the lungs, liver, intestines, heart, and kidneys. Multiple signaling pathways have been implicated in sepsis, including JNK/c-Myc, Mst1-JNK, MKK4-JNK, JNK-dependent autophagy, and Sirt1/FoxO3a. The review examines the role of JNK signaling in the development of sepsis-induced multiple-organ dysfunction through specific mechanisms. It also discusses different therapeutic approaches to target JNK. This review emphasizes the potential of JNKs as targets for the development of therapeutic agents for sepsis and the associated specific organ damage.

Analyzing how SiMiao Wan regulates ferroptosis to prevent RA-ILD using metabolomics and cyberpharmacology

BACKGROUND

Interstitial lung disease (ILD) is a common complication of rheumatoid arthritis (RA) that plays a significant role in the morbidity and mortality of individuals with this condition. In clinical settings, Si Miao Wan (SMW), a traditional Chinese medicine, is often utilized for the management of RA, as it is believed to possess properties that aid in reducing inflammation, eliminating excess moisture, and alleviating joint pain.

PURPOSE

The primary objective of this investigation was to elucidate the potential mechanism of RA-ILD prevention from the perspective of ferroptosis mediated by SMW.

METHODS

UPLC-Q-TOF/MS and network pharmacology were employed to forecast the potential targets of SMW for the early prevention of RA-ILD. Following this, HE staining, metabolomics, and RT-PCR were utilized to investigate the mechanism by which SMW prevents RA-ILD at an early stage.

RESULTS

Following six weeks of continuous administration of SMW extract at a dosage of 2.16 g/kg/day, it was observed that SMW exhibited early preventive effects against RA-ILD. Metabolomics analysis revealed seven potential biomarkers linked to the pharmacological efficacy of SMW in the early prevention of RA-ILD. Additionally, network pharmacology analysis suggested that SMW may exert its therapeutic effects on RA-ILD by modulating signaling pathways associated with lipid metabolism, atherosclerosis, TNF, and IL-17. Ultimately, through the integration of metabolomics and network pharmacology analysis, along with subsequent verification, it was determined that the early prevention of rheumatoid arthritis-associated interstitial lung disease (RA-ILD) by Shenmai injection (SMW) is associated with the ferroptosis pathway.

CONCLUSION

This research offers preliminary insights into the potential mechanism by which traditional Chinese medicine Shen Mai Wan (SMW) may mitigate the early onset of Rheumatoid Arthritis-Interstitial Lung Disease (RA-ILD) via the process of ferroptosis. Furthermore, it establishes a theoretical framework for the development of innovative SMW-based pharmaceuticals for the management of RA-ILD. The signal proteins implicated in this process are anticipated to emerge as crucial targets for the prevention of RA-ILD.

Update on JNK inhibitor patents: 2015 to present

INTRODUCTION

c-Jun N-terminal kinase (JNK) regulates various biological processes through the phosphorylation cascade and is closely associated with numerous diseases, including inflammation, cardiovascular diseases, and neurological disorders. Therefore, JNKs have emerged as potential targets for disease treatment.

AREAS COVERED

This review compiles the patents and literatures concerning JNK inhibitors through retrieving relevant information from the SciFinder, Google Patents databases, and PubMed from 2015 to the present. It summarizes the structure-activity relationship (SAR) and biological activity profiles of JNK inhibitors, offering valuable perspectives on their potential therapeutic applications.

EXPERT OPINION

The JNK kinase serves as a novel target for the treatment of neurodegenerative disorders, pulmonary fibrosis, and other illnesses. A variety of small-molecule inhibitors targeting JNKs have demonstrated promising therapeutic potential in preclinical studies, which act upon JNK kinases via distinct mechanisms, encompassing traditional ATP competitive inhibition, covalent inhibition, and bidentate inhibition. Among them, several JNK inhibitors from PregLem SA, Celegene SA, and Xigen SA have accomplished the early stage of clinical trials, and their results will guide the development and indications of future JNK inhibitors.

ZNL0325, a Pyrazolopyrimidine-Based Covalent Probe, Demonstrates an Alternative Binding Mode for Kinases

The pyrazolopyrimidine (PP) heterocycle is a versatile and widely deployed core scaffold for the development of kinase inhibitors. Typically, a 4-amino-substituted pyrazolopyrimidine binds in the ATP-binding pocket in a conformation analogous to the 6-aminopurine of ATP. Here, we report the discovery of ZNL0325 which exhibits a flipped binding mode where the C3 position is oriented toward the ribose binding pocket. ZNL0325 and its analogues feature an acrylamide side chain at the C3 position which is capable of forming a covalent bond with multiple kinases that possess a cysteine at the αD-1 position including BTK, EGFR, BLK, and JAK3. These findings suggest that the ability to form a covalent bond can override the preferred noncovalent binding conformation of the heterocyclic core and provides an opportunity to create structurally distinct covalent kinase inhibitors.

The Role of the Dysregulated JNK Signaling Pathway in the Pathogenesis of Human Diseases and Its Potential Therapeutic Strategies: A Comprehensive Review

JNK is named after c-Jun N-terminal kinase, as it is responsible for phosphorylating c-Jun. As a member of the mitogen-activated protein kinase (MAPK) family, JNK is also known as stress-activated kinase (SAPK) because it can be activated by extracellular stresses including growth factor, UV irradiation, and virus infection. Functionally, JNK regulates various cell behaviors such as cell differentiation, proliferation, survival, and metabolic reprogramming. Dysregulated JNK signaling contributes to several types of human diseases. Although the role of the JNK pathway in a single disease has been summarized in several previous publications, a comprehensive review of its role in multiple kinds of human diseases is missing. In this review, we begin by introducing the landmark discoveries, structures, tissue expression, and activation mechanisms of the JNK pathway. Next, we come to the focus of this work: a comprehensive summary of the role of the deregulated JNK pathway in multiple kinds of diseases. Beyond that, we also discuss the current strategies for targeting the JNK pathway for therapeutic intervention and summarize the application of JNK inhibitors as well as several challenges now faced. We expect that this review can provide a more comprehensive insight into the critical role of the JNK pathway in the pathogenesis of human diseases and hope that it also provides important clues for ameliorating disease conditions.

Discovery of the Diphenyl 6-Oxo-1,6-dihydropyridazine-3-carboxylate/carboxamide Analogue J27 for the Treatment of Acute Lung Injury and Sepsis by Targeting JNK2 and Inhibiting the JNK2-NF-κB/MAPK Pathway

Acute lung injury (ALI) and sepsis are both serious and complex conditions associated with high mortality, yet there are no effective treatments. Herein, we designed and synthesized a series of diphenyl 6-oxo-1,6-dihydropyridazine-3-carboxylate/carboxamide analogues exhibiting anti-inflammatory activity. The optimal compound J27 decreased the release of TNF-α and IL-6 in mouse and human cells J774A.1 and THP-1 (IL-6 IC50 = 0.22 μM) through the NF-κB/MAPK pathway. J27 demonstrated remarkable protection against ALI and sepsis in vivo and exhibited good safety in subacute toxicity experiments. Pharmacokinetic study indicated that J27 had good bioavailability (30.74%). To our surprise, J27 could target JNK2 with a totally new molecular skeleton compared with the only few JNK2 inhibitors reported. Moreover, there is no report that JNK2 inhibitors could apply for ALI and sepsis. Therefore, this work provides a new lead structure for the study of JNK2 inhibitors and a new target of JNK2 to treat ALI and sepsis.

JNK2 Promotes Progression of Esophageal Squamous Cell Carcinoma via Inhibiting Axin2

INTRODUCTION

The dysregulation of the c-Jun NH2-terminal kinase (JNK) pathway has been increasingly reported in human malignancies. Aberrant expression of the JNK pathway has also been implicated in the progression of Esophageal Squamous Cell Carcinoma (ESCC). However, the specific role and regulatory mechanisms of JNK2 in ESCC have not been extensively investigated.

METHODS

In this study, we examined JNK2 expression in patient samples and performed experiments involving the knockdown and inhibition of the JNK2 in ESCC cell lines.

RESULTS

Higher JNK2 expression was observed in tumor tissues compared to adjacent tissues. JNK2 overexpression was associated with advanced disease stages and poor prognosis. Furthermore, knockdown or inhibition of JNK2 in ESCC cell lines resulted in a decrease in cell proliferation and migration.

CONCLUSION

Additionally, a significant decrease in the expression of β-catenin and vimentin, along with an increase in the expression of Axin2, was observed upon downregulation of JNK2. Our study provides insight into the role of JNK2 in ESCC and its potential regulatory mechanism, offering a potential therapeutic strategy for ESCC patients with aberrant JNK2 expression.

A patent review of MAPK inhibitors (2018 - present)

INTRODUCTION

The mitogen-activated protein kinase (MAPK) family consist of p38 MAP kinases, c-Jun N-terminal kinases (JNKs) and extracellular signal-regulated kinases (ERKs). They are involved in a multitude of diseases, including inflammatory, autoimmune, neurodegenerative, and metabolic diseases as well as cancer. In recent years, further developments in the field of MAPK-inhibitors have been reported, including an isoform or downstream target selective inhibition of MAPKs as well as target protein degradation approaches.

AREAS COVERED

This review summarizes newly patented MAPK-inhibitors that were claimed between 2018 and early 2023. Presented are the patents as well as their corresponding publications, the storyline of development, and clinical trials involving these compounds. This article elaborates a total of 27 patents, which were identified using established search engines.

EXPERT OPINION

Although industrial research on MAPK-inhibitors has been ongoing for more than 20 years, novel clinical trials of MAPK-inhibitors as potential drug candidates are still being conducted in the period under review. Recently reported inhibitors show an excellent selectivity profile and are even achieving selectivity between closely related isoforms. This progression offers the possibility to eliminate unwanted side effects and may finally lead to the approval of the first MAPK-inhibitor.