Danggui Sini decoction attenuates intervertebral disc degeneration by regulating ferroptosis in nucleus pulposus cells via the GJA1/cGAS/STING signaling axis

Background: Intervertebral disc degeneration (IDD) stands as a leading culprit behind low back pain, ranking among the most widespread musculoskeletal conditions globally and placing a considerable strain on healthcare systems worldwide. Danggui Sini Decoction (DSD), a classical prescription from the Treatise on Cold Damage Diseases, has demonstrated therapeutic potential in the treatment of IDD. However, its underlying molecular mechanisms remain unclear.

Methods: Bioinformatics analyses were first performed to identify key mechanisms involved in IDD pathogenesis. The active compounds of DSD were characterized using high-performance liquid chromatography (HPLC). Network pharmacology analysis identified Gap Junction Protein alpha 1 (GJA1) as a key target, and molecular docking was conducted to assess the binding affinity of key DSD components with GJA1. An in vitro degeneration model was developed using nucleus pulposus (NP) cells exposed to interleukin-1β (IL-1β), combined with Ferroptosis inhibitors or activators. Cell viability, mitochondrial function, Ferroptosis markers, and extracellular matrix (ECM)-related indicators were evaluated. Transcriptomic Sequencing was performed to explore potential signaling pathways. In rescue experiments, Western blotting and fluorescence probe staining were used to further assess the role of the GJA1/cGAS/STING pathway in DSD-mediated Ferroptosis regulation. Additionally, a rat IDD model was established and treated with oral DSD administration, with Fer-1, erastin, and a GJA1 inhibitor used as controls. Radiological assessment and histological staining were employed to evaluate the therapeutic efficacy of DSD in vivo.

Results: Bioinformatics analysis identified Ferroptosis as a critical contributor to IDD progression. Major active compounds of DSD exhibited strong binding affinity to GJA1. Both in vitro and in vivo experiments demonstrated that DSD significantly reduced Ferroptosis, alleviated ECM degradation, and attenuated IL-1β-induced NP cell degeneration, thereby inhibiting IDD progression. These protective effects were closely associated with modulation of the GJA1/cGAS/STING signaling pathway.

Conclusion: DSD suppresses the GJA1/cGAS/STING signaling axis, reduces lipid peroxidation and intracellular iron accumulation, effectively attenuates Ferroptosis, and delays the progression of IDD. This study highlights the therapeutic potential of DSD as a ferroptosis-targeting intervention and provides novel mechanistic insights supporting its broader clinical application.

Danggui Sini decoction; Ferroptosis; GJA1; Intervertebral disc degeneration; cGAS/STING signaling axis.