scholarly journals Ligustrazine Prevents Intervertebral Disc Degeneration via Suppression of Aberrant TGFβ Activation in Nucleus Pulposus Cells

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Shufen Liu ◽  
Yuhao Cheng ◽  
Yuqi Tan ◽  
Jingcheng Dong ◽  
Qin Bian

Objectives. Aberrant transforming growth factor β (TGFβ) activation is detrimental to both nucleus pulposus (NP) cells and cartilage endplates (CEPs), which can lead to intervertebral disc degeneration (IDD). Ligustrazine (LIG) reduces the expression of inflammatory factors and TGFβ1 in hypertrophic CEP to prevent IDD. In this study, we investigate the effects of LIG on NP cells and the TGFβ signaling. Design. LIG was injected to the lumbar spinal instability (LSI) mouse model. The effect of LIG was evaluated by intervertebral disc (IVD) score in the LSI mouse model. The expression of activated TGFβ was examined using immunostaining with pSmad2/3 antibody. The upright posture (UP) rat model was also treated and evaluated in the same manner to assess the effect of LIG. In ex vivo study, IVDs from four-week old mice were isolated and treated with 10−5, 10−6, and 10−7 M of LIG. We used western blot to detect activated TGFβ expression. TGFβ-treated human nucleus pulposus cells (HNPCs) were cotreated with optimized dose of LIG in vitro. Immunofluorescence staining was performed to determine pSmad2/3, connective tissue growth factor (CCN2), and aggrecan (ACAN) expression levels. Results. IVD score and the percentage of pSmad2/3+ NP cells were low in LIG-treated LSI mice in comparison with LSI mice, but close to the levels in the Sham group. Similarly, LIG reduced the overexpression of TGFβ1 in NP cells. The inhibitory effect of LIG was dose dependent. A dose of 10−5 M LIG not only strongly attenuated Smad2/3 phosphorylation in TGFβ-treated IVD ex vivo but also suppressed pSmad2/3, CCN2, and ACAN expression in TGFβ-treated NP cells in vitro. Conclusions. LIG prevents IDD via suppression of TGFβ overactivation in NP cells.

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Sunli Hu ◽  
Chenxi Zhang ◽  
Tianchen Qian ◽  
Yue Bai ◽  
Liang Chen ◽  
...  

One of the causes of intervertebral disc degeneration (IVDD) is nucleus pulposus cell (NPC) death, possibly apoptosis. In this study, we explored the role of the Nrf2/Sirt3 pathway and tert-butylhydroquinone (t-BHQ) in IVDD and elucidated the potential working mechanism. Reactive oxygen species (ROS) assay kits and malondialdehyde (MDA) assay kits were used to assess oxidative stress. Western blot and TUNEL staining were used to examine apoptosis. After siRNA against Nrf2 or lentivirus against Sirt3 was transfected into NPCs, the mechanism of the effect of the Nrf2/Sirt3 pathway on NPCs was assessed. The interaction between t-BHQ and its potential interacting protein NRF2 was further investigated through protein docking analysis. ChIP examined the binding affinity between Nrf2 and Sirt3 promoter. In vivo experiments, X-ray, hematoxylin-eosin (HE) staining, Safranin O staining, and immunohistochemistry were used to evaluate IVDD grades. The results demonstrated that activation of the Nrf2/Sirt3 pathway inhibited tert-butyl hydroperoxide- (TBHP-) induced apoptosis and mitochondrial dysfunction in vitro. In addition to apoptosis, upregulation of the Nrf2/Sirt3 pathway induced by t-BHQ restored TBHP-induced autophagic flux disturbances. However, its protective effect was reversed by chloroquine and Si-ATG5. Furthermore, t-BHQ ameliorated IVDD development in a rat model. In conclusion, our findings indicate that the Nrf2/Sirt3 pathway and its agonist represent a potential candidate for treating IVDD.


2018 ◽  
Vol 46 (07) ◽  
pp. 1561-1580 ◽  
Author(s):  
Zengjie Zhang ◽  
Chenggui Wang ◽  
Jialiang Lin ◽  
Haiming Jin ◽  
Ke Wang ◽  
...  

Intervertebral disc degeneration (IDD) is a major cause of lower back pain, but few efficacious medicines have been developed for IDD. Increased nucleus pulposus cells apoptosis is a dominant pathogenesis of IDD and is considered a therapeutic target. Previously, our group proved that autophagy may protect nucleus pulposus cells against apoptosis. As one of the major bioflavonoids of citrus, naringin activates autophagy. Therefore, we hypothesize that naringin may have therapeutic potential for IDD by activating autophagy in nucleus pulposus cells. In this study, we evaluated the effects of naringin on TBHP-induced oxidative stress in nucleus pulposus cells in vitro as well as in puncture-induced rat IDD model in vivo. Our results showed that naringin could reduce the incidence of oxidative stress-induced apoptosis in nucleus pulposus cells and promoted the expression of autophagy markers LC3-II/I and beclin-1. Meanwhile, inhibition of autophagy by 3-MA may partially reverse the anti-apoptotic effect of naringin, indicating that autophagy was involved in the protective effect of naringin in nucleus pulposus cells. Further study showed that autophagy regulation of naringin may be related to AMPK signaling. Also, we found that naringin treatment can regulate the expression of collagen II, aggrecan and Mmp13 to sustain the extracellular matrix. Furthermore, our in vivo study showed that naringin can ameliorate IDD in puncture-induced rat model. In conclusion, our study suggests that naringin can protect nucleus pulposus cells against apoptosis and ameliorate IDD in vivo, the mechanism may relate to its autophagy regulation.


2016 ◽  
Vol 38 (1) ◽  
pp. 295-305 ◽  
Author(s):  
Jin Feng Ma ◽  
Li Na Zang ◽  
Yong Ming Xi ◽  
Wen Jiu Yang ◽  
Debo Zou

Background: Spinal degenerative diseases are a major health problem and social burden worldwide. Intervertebral disc degeneration (IDD) is the pathological basis of spinal degenerative diseases and is characterized by loss of nucleus pulposus cells due to excessive apoptosis caused by various factors. MicroRNAs (miRNAs) have been reported to be functionally involved in the control of apoptosis. Methods: computational analysis and luciferase assay were used to identify the target of miR-125a, and cell culture, transfection were used to confirm such relationship. Sequencing was used to determine the genotype of each participant. Results: We confirmed the previous report that the presence of the minor allele (T) of rs12976445 polymorphism significantly downregulated the expression level of miR-125a in nucleus pulposus cells, leading to less efficient inhibition of its target gene. We also validated TP53INP1 as a target of miR-125a in nucleus pulposus cells using a dual luciferase reporter system, and the transfection of miR-125a significantly reduced the expression of TP53INP1. The expression level of TP53INP1 was significantly lower in nucleus pulposus cells genotyped as CT or TT than in those genotyped as CC, and the apoptosis rate was consistently lower in the CC group than in the nucleus pulposus cells collected from individuals carrying at least one minor allele of rs12976445 polymorphism. To study the association between rs12976445 polymorphism and the risk of IDD, we enrolled 242 patients diagnosed with IDD and 278 normal controls, and significant differences were noted regarding the genotype distribution of rs12976445 between the IDD and the control groups (OR = 2.69, 95% C.I. = 1.88-3.83, p < 0.0001). In summary, rs12976445 polymorphism is significantly associated with the risk of IDD in the Chinese population. Conclusion: The present study indicated that miR-125a is a promising potential target for patients with IDD in clinical practice.


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