scholarly journals The REDD1/TXNIP Complex Accelerates Oxidative Stress-Induced Apoptosis of Nucleus Pulposus Cells through the Mitochondrial Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-22
Author(s):  
Huipeng Yin ◽  
Kun Wang ◽  
Abhirup Das ◽  
Gaocai Li ◽  
Yu Song ◽  
...  

The death of nucleus pulposus (NP) cells is an important cause of intervertebral disc (IVD) degeneration. Redox disturbance caused by dysfunctional mitochondria has been considered as a vital risk for NP cell survival. It is valuable to identify key proteins maintaining mitochondrial function in NP cells. A previous study found that regulated in development and DNA damage response 1 (REDD1) are upregulated during intervertebral disc degeneration and that REDD1 can cause NP cell apoptosis. Thus, the present study further explores the effect of REDD1 on IVD degeneration. Our results showed that REDD1 promotes NP cell apoptosis via the mitochondrial pathway. Importantly, REDD1 formed a complex with TXNIP to strengthen its own action, and the combination was consolidated under H2O2-induced oxidative stress. The combined inhibition of the REDD1/TXNIP complex was better than that of REDD1 or TXNIP alone in restoring cell proliferation and accelerating apoptosis. Moreover, p53 acts as the transcription factor of REDD1 to regulate the REDD1/TXNIP complex under oxidative stress. Altogether, our results demonstrated that the REDD1/TXNIP complex mediated H2O2-induced human NP cell apoptosis and IVD degeneration through the mitochondrial pathway. Interferences on these sites to achieve mitochondrial redox homeostasis may be a novel therapeutic strategy for oxidative stress-associated IVD degeneration.

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yiqiang Hu ◽  
Ranyang Tao ◽  
Linfang Wang ◽  
Lang Chen ◽  
Ze Lin ◽  
...  

Oxidative stress is relevant in compression-induced nucleus pulposus (NP) cell apoptosis and intervertebral disc (IVD) degeneration. Exosomes derived from bone mesenchymal stem cells (BMSCs-Exos) are key secretory products of MSCs, with important roles in tissue regeneration. This research is aimed at studying the protective impact of BMSCs-Exos on NP cell apoptosis caused by compression and investigating the underlying mechanisms. Our results indicated that we isolated BMSCs successfully. Exosomes were isolated from the BMSCs and found to alleviate the inhibitory effect that compression has on proliferation and viability in NP cells, decreasing the toxic effects of compression-induced NP cells. AnnexinV/PI double staining and TUNEL assays indicated that the BMSCs-Exos reduced compression-induced apoptosis. In addition, our research found that BMSCs-Exos suppressed compression-mediated NP oxidative stress by detecting the ROS and malondialdehyde level. Furthermore, BMSCs-Exos increased the mitochondrial membrane potential and alleviated compression-induced mitochondrial damage. These results indicate that BMSCs-Exos alleviate compression-mediated NP apoptosis by suppressing oxidative stress, which may provide a promising cell-free therapy for treating IVD degeneration.


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.


Life Sciences ◽  
2018 ◽  
Vol 199 ◽  
pp. 122-130 ◽  
Author(s):  
Ruijun He ◽  
Min Cui ◽  
Hui Lin ◽  
Lei Zhao ◽  
Jiayu Wang ◽  
...  

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Xiangyu Deng ◽  
Sheng Chen ◽  
Dong Zheng ◽  
Zengwu Shao ◽  
Hang Liang ◽  
...  

Icariin is a prenylated flavonol glycoside derived from the Chinese herb Epimedium sagittatum. This study investigated the mechanism by which icariin prevents H2O2-induced apoptosis in rat nucleus pulposus (NP) cells. NP cells were isolated from the rat intervertebral disc and they were divided into five groups after 3 passages: (A) blank control; (B) 200 μM H2O2; (C) 200 μM H2O2 + 20 μM icariin; (D) 20 μM icariin + 200 μM H2O2 + 25 μM LY294002; (E) 200 μM H2O2 + 25 μM LY294002. LY294002 is a selective inhibitor of the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway. NP cell viability, apoptosis rate, intracellular reactive oxygen species levels, and the expression of AKT, p-AKT, p53, Bcl-2, Bax, caspase-3 were estimated. The results show that, compared with the control group, H2O2 significantly increased NP cell apoptosis and the level of intracellular ROS. Icariin pretreatment significantly decreased H2O2-induced apoptosis and intracellular ROS and upregulated p-Akt and BCL-2 and downregulated caspase-3 and Bax. LY294002 abolished the protective effects of icariin. Our results show that icariin can attenuate H2O2-induced apoptosis in rat nucleus pulposus cells and PI3K/AKT pathway is at least partly included in this protection effect.


2021 ◽  
Vol 8 ◽  
Author(s):  
Tao Lan ◽  
Yu-chen Zheng ◽  
Ning-dao Li ◽  
Xiao-sheng Chen ◽  
Zhe Shen ◽  
...  

ObjectiveThe aim of this study is to explore the role of Parkin in intervertebral disk degeneration (IDD) and its mitophagy regulation mechanism.Study design and methodsRat nucleus pulposus (NP) cells were stimulated with hydrogen peroxide (H2O2) to a mimic pathological condition. Apoptosis and mitophagy were assessed by Western blot, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, and immunofluorescence staining. The CRISPR–dCas9–KRAB system was used to silence the expression of Parkin.ResultIn this study, we found that Parkin was downregulated in rat NP cells under oxidative stress. In addition, treatment with H2O2 resulted in mitochondrial dysfunction, autophagy inhibition, and a significant increase in the rate of apoptosis of NP cells. Meanwhile, mitophagy inhibition enhanced H2O2-induced apoptosis. Furthermore, repression of Parkin significantly attenuated mitophagy and exacerbated apoptosis.ConclusionThese results suggested that Parkin may play a protective role in alleviating the apoptosis of NP cells via mitophagy, and that targeting Parkin may provide a promising therapeutic strategy for the prevention of IDD.


2018 ◽  
Vol 27 (10) ◽  
pp. 2609-2620 ◽  
Author(s):  
Ming-Bo Guo ◽  
De-Chun Wang ◽  
Hai-Fei Liu ◽  
Long-Wei Chen ◽  
Jian-Wei Wei ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Zhaohui Zhai ◽  
Zhaoxin Li ◽  
Zhonglei Ji ◽  
Xiaosheng Lu

Objective. Polygonatum sibiricum polysaccharide (PSP) has antioxidant activity, immune enhancement, and other biological properties. However, the effect of PSP on intervertebral disc degeneration has not been reported. In this study, we mainly investigated the effect of PSP on the apoptosis, inflammation, and oxidative stress of nucleus pulposus cells (NPCs) during the process of intervertebral disc degeneration. Methods. A rat NPC model induced by H2O2 was constructed. The CCK8 method was used to measure the effects of PSP on the apoptosis of rat NPCs induced by H2O2. The effects on the activity of SOD and content of MDA were also determined. The rat model of intervertebral disc degeneration was treated with PSP for 1 month, and the mRNA expression levels of IL-1β, COX2, iNOS, Col2α1, Col10α1, and MMP3 were measured by qPCR in the tissue of intervertebral disc. NPCs from the degenerated intervertebral discs were separated, and the cell viability was measured by the CCK8 method. The contents of SOD and MDA in NPCs were determined as well. Results. PSP significantly reduced the apoptosis of NPCs induced by H2O2, significantly increased the SOD content, and decreased the content of MDA in H2O2-induced NPCs. The expression level of IL-1β, COX2, and iNOS in the rat model with intervertebral disc degeneration was significantly downregulated after 1 month of PSP treatment. PSP treatment increased the expression of Col2α1 type and significantly decreased the expression of Col10α1 type collagen and MMP3 in rats with disc degeneration. PSP treatment significantly reduced NPC apoptosis and increased its SOD content and reduced MDA content, which is consistent with the results from cell-level experiments. Conclusion. PSP can effectively reduce the apoptosis, inflammation, and oxidative stress of H2O2-induced NPCs in rats with intervertebral disc degeneration and mitigate the progression of intervertebral disc degeneration, which has the potential to be developed as new drugs for the treatment of intervertebral disc degeneration.


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