The effects of pulsed electromagnetic field stimulation on nucleus pulposus cell inflammation and its mechanism
10.3760/cma.j.cn421666-20250404-00299
- VernacularTitle:脉冲电磁场对沉默腺苷受体2A介导的退变髓核细胞炎症的影响及机制研究
- Author:
Lei CAI
1
;
Qingbo LI
1
;
Chuankun ZHOU
1
;
Yichi ZHOU
1
;
Bowen KOU
1
;
Weijun LIU
1
Author Information
1. 武汉市第四医院脊柱外科中心，武汉 430030
- Publication Type:Journal Article
- Keywords:
Pulsed electromagnetic field stimulation;
A2A adenosine receptors;
NF-κB signaling;
Intervertebral disc degeneration
- From:
Chinese Journal of Physical Medicine and Rehabilitation
2025;47(9):769-775
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To observe any ability of pulsed electromagnetic field (PEMF) stimulation to regulate inflammation in degenerate nucleus pulposus cells.Methods:Primary nucleus pulposus cells from rats were cultured and divided into a control group, a model group, an A2AR-small interfering RNA group (A2AR-siRNA group), and a PEMF group. The control and model group cells were stimulated with tumor necrosis factor-α (TNF-α) in phosphate-buffered saline solution, those in the A2AR-siRNA and the PEMF groups were transfected with A2AR siRNA and given TNF-α stimulation. The PEMF group cells had four hours daily of PEMF irradiation beginning within 24 hours after the TNF-α stimulation for 2 days. After 48 hours, cell proliferation was detected by CCK8 assay, while the positive expression of A2AR in the nucleus pulposus cells was measured using immunofluorescence staining. The expression of A2AR, cyclic adenosine monophosphate (cAMP), protein kinase A (PKA), cAMP response element binding protein (CREB), nuclear factor-κB (NF-κB), nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3), and interleukin-6 (IL-6) in the cells was observed using western blotting and real-time fluorescence quantitative polymerase chain reactions.Results:The rate of cell proliferation among the model group was approximately 60%, significantly lower than that of the control group (100%), but significantly higher than that of the A2AR-siRNA group (approximately 34%). The cell proliferation rate of the PEMF group was approximately 80%, significantly higher than that of the model and A2AR-siRNA groups. Compared with the control group, the positive expression of A2AR in the nucleus pulposus cells, A2AR protein and mRNA in the model group increased significantly in response to stress. The expression of A2AR protein and mRNA in the A2AR-siRNA group and the PEMF group was significantly lower than in the model group. Compared with the control group, the cAMP level in the nucleus pulposus cells of the model group had decreased significantly. The cAMP content in the A2AR-siRNA group further decreased compared with the model group, and that in the PEMF group increased compared with the model and the A2AR-siRNA groups. The average expression of PKA and CREB in the model group was significantly higher than among the control group, while that of PKA and CREB in the A2AR-siRNA group was significantly lower. The PKA and CREB protein levels in the PEMF group were slightly higher than in the A2AR-siRNA group, but the difference was not statistically significant. The expression of NF-κB, NLRP3, and IL-6 protein and mRNA in the cells of the model group was significantly higher than in the control group, but those of the A2AR-siRNA group were significantly higher than in the model group. The levels in the PEMF group were significantly lower than among the model and A2AR-siRNA groups, on average.Conclusions:Down-regulation of A2AR content further aggravates the inflammatory injury of degenerated nucleus pulposus cells. The mechanism may be related to the down-regulation of CREB activity, activation of the NF-κB signaling pathway, and subsequent up-regulation of inflammatory factors NLRP3 and IL-6. PEMF stimulation cannot significantly increase the A2AR level in degenerated nucleus pulposus cells, but it can promote the expression of cAMP and inhibit the downstream NF-κB signaling pathway, thereby exerting an anti-inflammatory effect.
