Digoxin protects against intervertebral disc degeneration via TNF/NF-κB and LRP4 signaling

Qunbo Meng; Kaiwen Liu; Zhenchuan Liu; Jinbo Liu; Ziyu Tian; Shanshan Qin; Jianlu Wei; Lei Cheng

doi:10.3389/fimmu.2023.1251517

Digoxin protects against intervertebral disc degeneration via TNF/NF-κB and LRP4 signaling

Front Immunol. 2023 Sep 18:14:1251517. doi: 10.3389/fimmu.2023.1251517. eCollection 2023.

Authors

Qunbo Meng^{1

2}, Kaiwen Liu^{1

2}, Zhenchuan Liu^{1

2}, Jinbo Liu^{1

2}, Ziyu Tian^{2

3}, Shanshan Qin³, Jianlu Wei^{1

4}, Lei Cheng^{1

4}

Affiliations

¹ Department of Orthopaedic Surgery, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China.
² Qilu Hospital of Shandong University, Shandong University, Jinan, Shandong, China.
³ Department of Radiology, Qilu Hospital of Shandong University, Jinan, Shandong, China.
⁴ Qilu Hospital of Shandong University Spine and Spinal Cord Disease Research Center-International Chinese Musculoskeletal Research Society (ICMRS) Collaborating Center for Orthopaedic Translational Research, Shandong University, Jinan, Shandong, China.

Abstract

Background: Intervertebral disc degeneration (IVDD) is a leading cause of low back pain (LBP). The pathological process of IVDD is associated with inflammatory reactions and extracellular matrix (ECM) disorders. Digoxin is widely used for treating heart failure, and it has been reported to have anti-inflammatory effects.

Objective: This study is to investigate the role of digoxin in the pathogenesis of intervertebral disc degeneration as well as the involved molecular mechanism, particularly the potential target protein.

Methods: We exploited a rat needle model to investigate digoxin's role in intervertebral disc degeneration in vivo. Safranin O staining was used to measure cartilaginous tissue in the intervertebral disc. The morphological changes of intervertebral discs in animal models were determined by Hematoxylin-Eosin (H&E) staining and the pathological score. Primary nucleus pulposus cells (NP cells) from intervertebral discs of patients and murine were used in the present study. Western-Blotting assay, Real-time PCR assay, immunofluorescence staining, and immunochemistry were used to detect the role of digoxin in anti-TNF-α-induced inflammatory effects in vitro. Transfection of siRNA was used to regulate low-density lipoprotein receptor-related protein 4 (LRP4) expression in NP cells to investigate the potential protein target of digoxin.

Results: Digoxin protected against intervertebral disc degeneration in rat needle models. Digoxin was found to exert its disc-protective effects through at least three different pathways by a) suppressing TNF-α-induced inflammation, b) attenuating ECM destruction, c) significantly promoting ECM anabolism. Additionally, LRP4 was found to be the downstream molecule of digoxin in NP cells for anti-inflammation and regulation of ECM metabolism. The knockdown of LRP4 downregulated the protective effect of digoxin in NP cells.

Conclusion: These findings suggest that digoxin may be a potential therapeutic agent for intervertebral disc degeneration through anti-catabolism and pro-anabolism. Digoxin might also work as an alternative for other inflammation-related diseases.

Keywords: LRP4; TNF; digoxin; inflammation; intervertebral disc degeneration.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Digoxin / pharmacology
Digoxin / therapeutic use
Humans
Inflammation / metabolism
Intervertebral Disc Degeneration* / genetics
LDL-Receptor Related Proteins
Mice
NF-kappa B / metabolism
Rats
Tumor Necrosis Factor Inhibitors / therapeutic use
Tumor Necrosis Factor-alpha / metabolism

Substances

NF-kappa B
Digoxin
Tumor Necrosis Factor Inhibitors
Tumor Necrosis Factor-alpha
LRP4 protein, human
LDL-Receptor Related Proteins

Grants and funding

This study received funding from the National Natural Science Foundation of China (82272548). Funds supporting this research also include the Natural Science Foundation of Shandong Pvince, China (ZR2023MH194, ZR2022MH019).