Duhuo Jisheng Decoction inhibits SDF-1-induced inflammation and matrix degradation in human degenerative nucleus pulposus cells in vitro through the CXCR4/NF-κB pathway.

Lower back pain (LBP) is the most common disease in orthopedic clinics world-wide. A classic Fangji of traditional Chinese medicine, Duhuo Jisheng Decoction (DHJSD), has been proven clinically effective for LBP but its therapeutic mechanisms remain unclear. We hypothesized that DHJSD might relieve LBP through inhibiting the exaggerated proinflammatory cytokines and extracellular matrix (ECM) degradation. Thus, we studied the effects of DHJSD on stromal cell-derived factor-1 (SDF-1)-induced inflammation and ECM degradation in human nucleus pulposus cells (hNPCs). The primary hNPCs were isolated from either degenerated human intervertebral disc (HID) of LBP patients or normal HID of lumbar vertebral fracture patients, and cultured in vitro. The cells were treated with SDF-1 (10 ng/mL) and subsequently with different concentrations (100-500 µg/mL) of DHJSD for 24 h, respectively. We found that application of DHJSD significantly antagonized the SDF-1-induced production of proinflammatory cytokines and reduction of aggrecan and type II collagen in the hNPCs. DHJSD also markedly reduced the SDF-1-induced increase of CXCR4 and p-p65 and inhibited the nuclear translocation of p65 in the hNPCs. DHJSD, CXCR4-siRNA, and NF-κB inhibitor (BAY11-7082) caused the same inhibition of exaggerated proinflammatory cytokines in the SDF-1-treated hNPCs. These results provided compelling evidence that DHJSD may inhibit the generation of proinflammatory mediators and ECM degradation of HID through an orchestrated targeting at multiple molecules in the SDF-1/CXCR4/NF-κB pathway, thus offered novel mechanistic insights into the clinical effectiveness of DHJSD on LBP.

[Mechanism of Duhuo Jisheng decotion in delaying degeneration of nucleus pulposus cells in human intervertebral disc].

This paper aimed to investigate the role of Duhuo Jisheng decotion (DHJSD) in delaying human disc degeneration and its possible molecular mechanism. The intervertebral disc specimens were divided into normal and degenerated groups according to Pfirrmann classfication. The expressions of TNF-α, IL-1ß, MMP-3 and MMP-13 in intervertebral disc tissue were detected by Western blot and PCR. Then degenerated human primary NPCs were cultured in vitro, the viability of NPCs treated with stromal cell-derived factor-1 (SDF-1，10 µg·L⁻¹)and various concentrations of DHJSD was assessed by the CCK-8 assay, and the appropriate concentration was screened. The experiment was divided into three groups, control group, SDF-1 group and DHJSD plus SDF-1 group. The levels of TNF-α, IL-1ß, Agg, coIⅡ, MMP-3 and MMP-13 were detected. The levels of CXCR4, NF-κB major groups P65 phosphorylation (p-P65) and nuclear translocation, after treated with CXCR4 siRNA and NF-κB inhibitor (BAY11-7082) were measured by Western blot and immunofluorescence. At the same time, the expression of cell inflammatory factors and extracellular matrix were also measured. The expressions of TNF-α, IL-1ß, MMP-3 and MMP-13 in the degenerated intervertebral disc tissue were significantly increased. In vitro study, the results of CCK-8 indicated that the viability of NPCs was significantly increased when DHJSD concentration was 300 mg·L⁻¹. After the experiment was divided into three groups, compared with SDF-1 group, the expressions of TNF-α, IL-1ß, MMP-3 and MMP-13 in DHJSD group were significantly decreased, but the expressions of Agg, coIⅡ were significantly increased. When CXCR4-siRNA was transfected into NPCs, SDF-1 increased expressions of CXCR4 and p-P65 and inhibited nuclear translocation of P65, whose effect was suppressed by CXCR4-siRNA and DHJSD. In addition, when BAY11-7082 was used to treat NPCs, the expression of TNF-α, IL-1ß, MMP-3 and MMP-13 were significantly decreased. DHJSD could inhibit the production of inflammatory factors and promote the synthesis of extracellular matrix. The potential mechanism may be related to the SDF-1/CXCR4/NF-κB signaling pathway.