scholarly journals CB2-mediated attenuation of nucleus pulposus degeneration via the amelioration of inflammation and oxidative stress in vivo and in vitro

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Xiaoqiang Cheng ◽  
Jiayi Lin ◽  
Zhanghuan Chen ◽  
Yubo Mao ◽  
Xiexin Wu ◽  
...  

Abstract Background Nucleus pulposus cell (NPC) degeneration is widely accepted as one of the major causes of intervertebral disc (IVD) degeneration (IVDD). The pathogenesis of IVDD is complex and consists of inflammation, oxidative stress, and the loss of extracellular matrix (ECM). Cannabinoid type 2 receptor (CB2) has been shown to be involved in the pathological mechanism of a variety of diseases due to its anti-inflammatory effects and antioxidative stress capacity. Method In Vitro, H2O2 was used to induce degeneration of nucleus pulposus cells, mRNA and protein expression level was determined by RT-PCR and Western Blot, and Immunocytochemical staining were used to detect expression of collagen II, aggrecan, MMP3/13, superoxide dismutase 2 (SOD2) and inducible nitric oxide synthase (iNOS). In vivo, the potential therapeutic effect of CB2 was detected in the rat acupuncture model. Result In vitro, we found that the CB2 agonist (JWH133) treatment reduced the oxidative stress level in NPCs induced by hydrogen peroxide (H2O2) treatment. Furthermore, the expression of inflammatory cytokines was also decreased by JWH133 treatment. We found that collagen II and aggrecan expression was preserved, whereas matrix metalloproteinase levels were reduced. In vivo, we established a rat model by needle puncture. Imaging assessment revealed that the disc height index (DHI) and morphology of IVD were significantly improved, and the disc degeneration process was delayed by treatment of JWH133. Furthermore, immunohistochemical (IHC) staining revealed that JWH133 could inhibit the degradation of collagen II and decrease the expression of MMP3. Conclusions The experiment indicates the oxidative stress and inflammatory response of rat NPCs induced by H2O2 could be inhibited by activating CB2. This study reveals that CB2 activation can effectively delay the development of IVDD, providing an effective therapeutic target for IVDD.

2022 ◽  
Vol 2022 ◽  
pp. 1-15
Author(s):  
Peng-Bo Chen ◽  
Gui-Xun Shi ◽  
Tao Liu ◽  
Bo Li ◽  
Sheng-Dan Jiang ◽  
...  

The process of intervertebral disc degeneration (IVDD) is complex, and its mechanism is considered multifactorial. Apoptosis of oxidative stressed nucleus pulposus cells (NPCs) should be a fundamental element in the pathogenesis of IVDD. In our pilot study, we found that the expression of MAT2A decreased, and METTL16 increased in the degenerative nucleus pulposus tissues. Previous studies have shown that the balance of splicing, maturation, and degradation of MAT2A pre-mRNA is regulated by METTL16 m6A modification. In the current study, we aimed to figure out whether this mechanism was involved in the aberrant apoptosis of NPCs and IVDD. Human NPCs were isolated and cultured under oxidative stress. An IVDD animal model was established. It showed that significantly higher METTL16 expression and lower MAT2A expression were seen in either the NPCs under oxidative stress or the degenerative discs of the animal model. MAT2A was inhibited with siRNA in vitro or cycloleucine in vivo. METTL16 was overexpressed with lentivirus in vitro or in vivo. Downregulation of MAT2A or upregulation of METTL16 aggravated nucleus pulposus cell apoptosis and disc disorganization. The balance of splicing, maturation, and degradation of MAT2A pre-mRNA was significantly inclined to degradation in the NPCs with the overexpression of METTL16. Increased apoptosis of NPCs under oxidative stress could be rescued by reducing the expression of METTL16 using siRNA with more maturation of MAT2A pre-mRNA. Collectively, oxidative stress aggravates apoptosis of NPCs through disrupting the balance of splicing, maturation, and degradation of MAT2A pre-mRNA, which is m6A modified by METTL16.


2021 ◽  
Vol 41 ◽  
pp. 90-107
Author(s):  
S Tang ◽  
◽  
A Salazar-Puerta ◽  
J Richards ◽  
S Khan ◽  
...  

Intervertebral disc (IVD) degeneration is characterized by decreased cellularity and proteoglycan synthesis and increased inflammation, catabolism, and neural/vascular ingrowth. Regenerative methods for IVD degeneration are largely cell-therapy-based or involve viral vectors, which are associated with mutagenesis and undesired immune responses. The present study used bulk electroporation and engineered extracellular vesicles (EVs) to deliver forkhead-box F1 (FOXF1) mRNA to degenerate human nucleus pulposus (NP) cells as a minimally invasive therapeutic strategy for IVD regeneration. Bulk electroporation was used to investigate FOXF1 effects on human NP cells during a 4-week culture in 3D agarose constructs. Engineered EV delivery of FOXF1 into human IVD cells in monolayer was determined, with subsequent in vivo validation in a pilot mouse IVD puncture model. FOXF1 transfection significantly altered gene expression by upregulating healthy NP markers [FOXF1, keratin 19 (KRT19)], decreasing inflammatory cytokines [interleukin (IL)-1β, -6], catabolic enzymes [metalloproteinase 13 (MMP13)] and nerve growth factor (NGF), with significant increases in glycosaminoglycan accumulation in human NP cells. Engineered EVs loaded with FOXF1 demonstrated successful encapsulation of FOXF1 cargo and effective uptake by human NP cells cultured in monolayer. Injection of FOXF1-loaded EVs into the mouse IVD in vivo resulted in a significant upregulation of FOXF1 and Brachyury, compared to controls at 7 d post-injection, with no evidence of cytotoxicity. This is the first study to demonstrate non-viral delivery of FOXF1 and reprogramming of human NP cells in vitro and mouse IVD cells in vivo. This strategy represents a non-addictive approach for treating IVD degeneration and associated back pain.


2019 ◽  
Vol 51 (11) ◽  
pp. 1-16 ◽  
Author(s):  
Wen-Ning Xu ◽  
Huo-Liang Zheng ◽  
Run-Ze Yang ◽  
Tao Liu ◽  
Wei Yu ◽  
...  

AbstractThe main pathological mechanism of intervertebral disc degeneration (IVDD) is the programmed apoptosis of nucleus pulposus (NP) cells. Oxidative stress is a significant cause of IVDD. Whether mitophagy is induced by strong oxidative stress in IVDD remains to be determined. This study aimed to investigate the relationship between oxidative stress and mitophagy and to better understand the mechanism of IVDD in vivo and in vitro. To this end, we obtained primary NP cells from the human NP and subsequently exposed them to TBHP. We observed that oxidative stress induced mitophagy to cause apoptosis in NP cells, and we suppressed mitophagy and found that NP cells were protected against apoptosis. Interestingly, TBHP resulted in mitophagy through the inhibition of the HIF-1α/NDUFA4L2 pathway. Therefore, the upregulation of mitochondrial NDUFA4L2 restricted mitophagy induced by oxidative stress. Furthermore, the expression levels of HIF-1α and NDUFA4L2 were decreased in human IVDD. In conclusion, these results demonstrated that the upregulation of NDUFA4L2 ameliorated the apoptosis of NP cells by repressing excessive mitophagy, which ultimately alleviated IVDD. These findings show for the first time that NDUFA4L2 and mitophagy may be potential therapeutic targets for 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.


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.


2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Feng Wang ◽  
Li-ping Nan ◽  
Shi-feng Zhou ◽  
Yang Liu ◽  
Ze-yu Wang ◽  
...  

Stem cell-based tissue engineering in treating intervertebral disc (IVD) degeneration is promising. An appropriate cell scaffold can maintain the viability and function of transplanted cells. Injectable hydrogel has the potential to be an appropriate cell scaffold as it can mimic the condition of the natural extracellular matrix (ECM) of nucleus pulposus (NP) and provide binding sites for cells. This study was aimed at investigating the effect of injectable hydrogel-loaded NP-derived mesenchymal stem cells (NPMSC) for the treatment of IVD degeneration (IDD) in rats. In this study, we selected injectable 3D-RGD peptide-modified polysaccharide hydrogel as a cell transplantation scaffold. In vitro, the biocompatibility, microstructure, and induced differentiation effect on NPMSC of the hydrogel were studied. In vivo, the regenerative effect of hydrogel-loaded NPMSC on degenerated NP in a rat model was evaluated. The results showed that NPMSC was biocompatible and able to induce differentiation in hydrogel in vivo. The disc height index (almost 87%) and MRI index (3313.83±227.79) of the hydrogel-loaded NPMSC group were significantly higher than those of other groups at 8 weeks after injection. Histological staining and immunofluorescence showed that the hydrogel-loaded NPMSC also partly restored the structure and ECM content of degenerated NP after 8 weeks. Moreover, the hydrogel could support long-term NPMSC survival and decrease cell apoptosis rate of the rat IVD. In conclusion, injectable hydrogel-loaded NPMSC transplantation can delay the level of IDD and promote the regeneration of the degenerative IVD in the rat model.


2017 ◽  
Vol 16 (6) ◽  
pp. 9521-9527 ◽  
Author(s):  
Lei Ding ◽  
Qingmin Zeng ◽  
Jingping Wu ◽  
Defang Li ◽  
Houlei Wang ◽  
...  

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 12 ◽  
Author(s):  
Liang Tan ◽  
Yifang Xie ◽  
Ye Yuan ◽  
Kai Hu

The role of lncRNA growth arrest specific 5 (GAS5) in degenerative nucleus pulposus cell (NPC) apoptosis has been reported, but the mechanism of GAS5 in extracellular matrix (ECM) synthesis in intervertebral disc degeneration (IDD) remains unknown. We aimed to investigate the mechanism of GAS5 in ECM synthesis in degenerative NPCs. GAS5 expression was measured in degenerative NPCs (CP-H170) and normal NPCs (CP-H097). siRNA-mediated GAS5 knockdown was transfected to NPCs to detect cell viability and the expression of ECM-related genes (Collagen II, aggrecan, Collagen I, and MMP-3). Subcellular localization of GAS5 was analyzed. The downstream gene and pathway of GAS5 in degenerative NPCs were explored. As our results indicated, lncRNA GAS5 was upregulated in degenerative NPCs. Silencing GAS5 improved the viability of degenerative NPCs and increased ECM synthesis. GAS5 was mainly located in the cytoplasm of NPCs. LncRNA GAS5 sponged miR-26a-5p to regulate PTEN. Overexpression of miR-26a-5p promoted ECM synthesis in degenerative NPCs. Akt inhibitor LY294002 reversed the promotion of silencing GAS5 on ECM synthesis of degenerative NPCs. In conclusion, lncRNA GAS5 sponged miR-26a-5p to upregulate PTEN and inhibit the PI3K/Akt pathway, thus inhibiting ECM synthesis of degenerative NPCs.


2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Kaiqiang Sun ◽  
Jian Zhu ◽  
Chen Yan ◽  
Fudong Li ◽  
Fanqi Kong ◽  
...  

Chronic low back pain (CLBP) has been proved to be the dominating cause of disability in patients with lumbar degenerative diseases. Of the various etiological factors, intervertebral disc degeneration (IVDD) has been the dominating cause. In the past few decades, the role and changes of nerve systems, especially the peripheral sensory fibers and their neurotransmitters, in the induction and progression of IVDD have attracted growing concerns. The expression of many neuropeptides, such as SP, NPY, and CGRP, in the nociceptive pathways is increased during the progression of IVDD and responsible for the discogenic pain. Here, the role of CGRP in the progression of IVDD was firstly investigated both in vitro and in vivo. Firstly, we confirmed that human degenerated intervertebral disc tissue exhibited elevated expression of CGRP and its receptor. Secondly, in vitro experiments suggested that CGRP could inhibit the proliferation and induce apoptosis in human nucleus pulposus (NP) cells, as well as promote inflammation and degenerated phenotypes through activating NF-κB and MAPK signaling pathways. Thirdly, CGRP receptor antagonist, Rimegepant, can ameliorate the adverse effects of CGRP imposed on NP cells, which were confirmed in vitro and in vivo. Our results will bring about a brand-new insight into the roles of neuromodulation in IVDD and related therapeutic attempts.


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