Quercetin is a Potential Therapy for Rheumatoid Arthritis via Targeting Caspase-8 Through Ferroptosis and Pyroptosis

Abstract

Background

Rheumatoid arthritis (RA) is one of the most common chronic inflammatory autoimmune diseases. However, the underlying molecular mechanisms of its pathogenesis are unknown. This study aimed to identify the common biomarkers of ferroptosis and pyroptosis in RA and screen potential drugs.

Methods

The RA-related differentially expressed genes (DEGs) in GSE55235 were screened by R software and intersected with ferroptosis and pyroptosis gene libraries to obtain differentially expressed ferroptosis-related genes (DEFRGs) and differentially expressed pyroptosis-related genes (DEPRGs). We performed Gene Ontology (GO), Kyoto Encyclopedia of the Genome (KEGG), ClueGO, and Protein-Protein Interaction (PPI) analysis for DEFRGs and DEPRGs and validated them by machine learning. The microRNA/transcription factor (TF)-hub genes regulatory network was further constructed. The key gene was validated using the GSE77298 validation set, cellular validation was performed in in vitro experiments, and immune infiltration analysis was performed using CIBERSORT. Network pharmacology was used to find key gene-targeting drugs, followed by molecular docking and molecular dynamics simulations to analyze the binding stability between small-molecule drugs and large-molecule proteins.

Results

Three hub genes (CASP8, PTGS2, and JUN) were screened via bioinformatics, and the key gene (CASP8) was validated and obtained through the validation set, and the diagnostic efficacy was verified to be excellent through the receiver operating characteristic (ROC) curves. The ferroptosis and pyroptosis phenotypes were constructed by fibroblast-like synoviocytes (FLS), and caspase-8 was detected and validated as a common biomarker for ferroptosis and pyroptosis in RA, and quercetin can reduce caspase-8 levels. Quercetin was found to be a potential target drug for caspase-8 by network pharmacology, and the stability of their binding was further verified using molecular docking and molecular dynamics simulations.

Conclusion

Caspase-8 is an important biomarker for ferroptosis and pyroptosis in RA, and quercetin is a potential therapy for RA via targeting caspase-8 through ferroptosis and pyroptosis.

Keywords:

• rheumatoid arthritis
• ferroptosis
• pyroptosis
• caspase-8
• quercetin

Abbreviations

DEGs, Differentially expressed genes; FRGs, Ferroptosis-related genes; PRGs, Pyroptosis-related genes; DEFRGs, Differentially expressed ferroptosis-related genes; DEPRGs, Differentially expressed pyroptosis-related genes; RA, Rheumatoid arthritis; HC, Healthy controls; PCD, programmed cell death; ROS, Reactive oxygen species; GO, Gene ontology; KEGG, Kyoto encyclopedia of genes and genomes; PPI, Protein-protein interaction; TF, Transcription factor; ROC, Receiver operating characteristic curve; AUC, Area under the curve; NLR, NOD-like receptor; NLRP3, NOD-like receptor family pyrin domain containing 3; ASC, Apoptosis-associated speck-like protein; GSDMD, Gasdermin-D; PAMP, Pathogen-associated molecular pattern; DAMP, Damage-associated molecular pattern; STAT, Signal transducer and activator of transcription; NF-κB, Nuclear factor-kappa B; Tfh, Follicular helper T cells; FLS, Fibroblast-like synoviocytes; GPX4, Glutathione peroxidase 4; DED, Death effector domain; SLC7A11, Solute carrier family 7 member 11; GCLC, Glutamate-cysteine ligase catalytic subunit; GCLM, Glutamate cysteine ligase-modifier subunit.

Data Sharing Statement

Publicly available datasets (GSE55235, GSE77298) were analyzed in this study. All data were available from public databases and can be found in the GEO database (https://wwwncbinmnihgov/geo/), FerrDb database (http://www.zhounan.org/ferrdb/current/), Genecards database (https://www.genecards.org/). All the raw data is contained in Supplementary Material and uploaded to GitHub, which is HTTPS (https://github.com/zheng5862/zheng5862.git).

Acknowledgments

We acknowledge the GEO, FerrDb, and Genecards databases for providing their platforms and contributors for uploading meaningful datasets.

Author Contributions

Each author significantly contributed to various aspects of the reported work, including conception, study design, execution, data acquisition, analysis and interpretation, drafting, revising, and critical review of the article. All authors provided final approval for the submitted version and the selected journal, demonstrating their commitment to the complete research process and assuming accountability.

Disclosure

The authors declare that the research was conducted without commercial or financial relationships construed as a potential conflict of interest.

Additional information

Funding

The Natural Science Foundation of Fujian Province (No. 2020J01947, No. 2021J02035) and Fujian Provincial Health Technology Project (No. 2020CXA039, No. 2021CXA019) supported the study.