scholarly journals Resveratrol inhibits IL-1β-mediated nucleus pulposus cell apoptosis through regulating the PI3K/Akt pathway

2019 ◽  
Vol 39 (3) ◽  
Author(s):  
Yanhai Jiang ◽  
Zhijie Xie ◽  
Jinying Yu ◽  
Lianqiang Fu

Abstract Nucleus pulposus (NP) cell apoptosis is a classical cellular character during intervertebral disc degeneration (IDD). Previous studies have shown that inflammatory cytokine-induced NP cell apoptosis plays an important role in disc degeneration. The present study was aimed to investigate whether resveratrol can suppress IL-1β-mediated NP cell apoptosis and the potential signal transduction pathway. Experimental rat NP cells were treated with culture medium containing IL-1β (20 ng/ml) for 7 days. Control NP cells were cultured in the baseline medium. Resveratrol was added along with culture medium to investigate its effects. The inhibitor LY294002 was used to study the role of the PI3K/Akt pathway. NP cell apoptosis was reflected by the caspase-3 activity, cell apoptosis ratio, and expression of apoptosis-related molecules (Bcl-2, Bax, caspase-3, cleaved caspase-3, and cleaved PARP). Compared with the control NP cells, IL-1β significantly increased caspase-3 activity, NP cell apoptosis ratio and mRNA/protein expression of Bax, caspase-3, cleaved caspase-3 and cleaved PARP, but decreased mRNA expression of Bcl-2. However, resveratrol partly suppressed the effects of IL-1β on those cell apoptosis-related parameters. Further analysis showed that IL-1β significantly decreased activity of the PI3K/Akt pathway whereas resveratrol partly increased activity of the PI3K/Akt pathway in NP cells treated with IL-1β. Additionally, when the inhibitor LY294002 was added along with the resveratrol, its protective effects against IL-1β-induced NP cell apoptosis were attenuated. In conclusion, resveratrol suppresses IL-1β-mediated NP cell apoptosis through activating the PI3K/Akt pathway. Resveratrol may be an effective drug to attenuate inflammatory cytokine-induced disc degenerative changes.

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Jian Li ◽  
Chengqiang Wang ◽  
Lixin Xue ◽  
Fan Zhang ◽  
Jianqiang Liu

Diabetes mellitus- (DM-) associated hyperglycemia promotes apoptosis of disc nucleus pulposus (NP) cells, which is a contributor to intervertebral disc degeneration (IDD). Melatonin is able to protect against cell apoptosis. However, its effects on apoptosis of NP cell in a high-glucose culture remain unclear. The purpose of the present study was to investigate the effects and molecular mechanism of melatonin on NP cell apoptosis in a high-glucose culture. NP cells were cultured in the baseline medium supplemented with a high-glucose concentration (0.2 M) for 3 days. The control cells were only cultured in the baseline medium. Additionally, the pharmaceutical inhibitor LY294002 was added along with the culture medium to investigate the possible role of the PI3K/Akt pathway. Apoptosis, autophagy, and activity of the PI3K/Akt pathway of NP cells among these groups were evaluated. Compared with the control NP cells, high glucose significantly increased cell apoptosis ratio and caspase-3/caspase-9 activity and decreased mRNA expression of Bcl-2, whereas it increased mRNA or protein expression of Bax, caspase-3, cleaved caspase-3, cleaved PARP, and autophagy-related molecules (Atg3, Atg5, Beclin-1, and LC3-II) and decreased protein expression of p-Akt compared with the control cells. Additionally, melatonin partly inhibited the effects of high glucose on those parameters of cell apoptosis, autophagy, and activation of PI3K/Akt. In conclusion, melatonin attenuates apoptosis of NP cells through inhibiting the excessive autophagy via the PI3K/Akt pathway in a high-glucose culture. This study provides new theoretical basis of the protective effects of melatonin against disc degeneration in a DM patient.


2019 ◽  
Vol 39 (4) ◽  
Author(s):  
Ziming Liu ◽  
Zhiwen Zhang ◽  
Ali Zhang ◽  
Fan Zhang ◽  
Wennan Du ◽  
...  

Abstract Increasing evidence has indicated a close relationship between diabetes mellitus (DM) and disc degeneration. As a potential therapeutic growth factor, osteogenic protein-1 (OP-1) has lots of protective effects on the healthy disc cell’s biology. The present study was aimed to investigate the effects of OP-1 on degenerative changes of nucleus pulposus (NP) cells in a high glucose culture. Rat NP cells were cultured in the baseline medium or the high glucose (0.2 M) culture medium. OP-1 was added into the high glucose culture medium to investigate whether its has some protective effects against degenerative changes of NP cells in the high glucose culture. NP cell apoptosis ratio, caspase-3/9 activity, expression of apoptosis-related molecules (Bcl-2, Bax, and caspase-3), matrix macromolecules (aggrecan and collagen II), and matrix remodeling enzymes (MMP-3, MMP-13, and ADAMTS-4), and immuno-staining of NP matrix proteins (aggrecan and collagen II) were evaluated. Compared with the baseline culture, high glucose culture significantly increased NP cell apoptosis ratio, caspase-3/9 activity, up-regulated expression of Bax, caspase-3, MMP-3, MMP-13 and ADAMTS-4, down-regulated expression of Bcl-2, aggrecan and collagen II, and decreased staining intensity of aggrecan and collagen II. However, the results of these parameters were partly reversed by the addition of OP-1 in the high glucose culture. OP-1 can alleviate high glucose microenvironment-induced degenerative changes of NP cells. The present study provides that OP-1 may be promising in retarding disc degeneration in DM patients.


2018 ◽  
Vol 38 (2) ◽  
Author(s):  
Wenping Wang ◽  
Pei Li ◽  
Jiagang Xu ◽  
Xiangkun Wu ◽  
Zhiliang Guo ◽  
...  

Background: Diabetes mellitus is closely correlated with disc degeneration. Nucleus pulposus (NP) cell apoptosis and senescence are typical cellular features within the degenerative disc. Resveratrol is a newly identified phytoalexin that has protective effects on cartilaginous tissue. Objective: To investigate the whether resveratrol can protect against high glucose-induced NP cell apoptosis and senescence, and the potential mechanism in this process. Methods: Rat NP cells were cultured in either 10% FBS culture medium (control group) or 10% FBS with a high glucose concentration (0.2 M, experiment group) for 3 days. Resveratrol or the combination of resveratrol and LY294002 was added into the culture medium of experiment group to investigate the effects of resveratrol and the PI3K/Akt pathway. Results: High glucose significantly promoted NP cell apoptosis and NP cell senescence compared with the control group. Resveratrol exhibited protective effects against high glucose-induced NP cell apoptosis and senescence. Further analysis showed that resveratrol suppressed reactive oxygen species (ROS) generation and increased the activity of the PI3K/Akt pathway under the high glucose condition. However, the LY294002 had no significant effects on ROS content in the resveratrol-treated high glucose group. Conclusion: Resveratrol can attenuate high glucose-induced NP cell apoptosis and senescence, and the activation of ROS-mediated PI3K/Akt pathway may be the potential mechanism in this process.


2018 ◽  
Vol 38 (6) ◽  
Author(s):  
Yan Yang ◽  
Xiyang Wang ◽  
Zheng Liu ◽  
Xiao Xiao ◽  
Wenkai Hu ◽  
...  

Background: Previous studies have indicated that osteogenic protein-1 has protective effects on the biological functions of intervertebral disc cells. Hyperosmolarity is an important physicochemical factor within the disc nucleus pulposus (NP) region, which obviously promotes NP cell apoptosis. Objective: To study the effects of osteogenic protein-1 (OP-1) on NP cell apoptosis induced by hyperosmolarity and the potential signaling transduction pathway. Methods: Rat NP cells were cultured in a hyperosmotic medium with or without OP-1 addition for 7 days. Inhibitor 294002 and inhibitor FK-506 were used to investigate the role of the PI3K/Akt/mTOR pathway in this process. NP cell apoptosis were evaluated by cell apoptosis ratio, activity of caspase-3/9 and gene/protein expression of apoptosis-related molecules (Bax, Bcl-2, caspase-3/cleaved caspase-3 and cleaved PARP). Results: OP-1 addition obviously decreased cell apoptosis ratio and caspase-3/9 activity, down-regulated gene/protein expression of pro-apoptosis molecules (Bax, caspase-3/cleaved casepase-3 and cleaved PARP), up-regulated gene/protein expression of anti-apoptosis molecule (Bcl-2) in a hyperosmotic culture. Moreover, OP-1 addition significantly increased protein expression of p-Akt and p-mTOR. Further analysis showed that addition of LY294002 and FK-506 partly attenuated these protective effects of OP-1 against NP cell apoptosis and activation of the PI3K/Akt/mTOR pathway in a hyperosmotic culture. Conclusion: OP-1 can attenuate NP cell apoptosis through activating the PI3K/Akt/mTOR pathway in a hyperosmotic culture. The present study sheds a new light on the protective role of OP-1 in regulating disc cell biology and provides some theoretical basis for the application of OP-1 in retarding/regenerating disc degeneration.


2018 ◽  
Vol 38 (6) ◽  
Author(s):  
Wei Yu ◽  
Jiabin Fu ◽  
Yan Liu ◽  
Yuchi Wu ◽  
Dianming Jiang

Background: Intervertebral disc degeneration is a pathological process that involves an inflammation response. As a classical cellular feature, several studies have demonstrated that inflammation can promote nucleus pulposus (NP) cell apoptosis. Therefore, attenuation of NP cell apoptosis may be a potential way to retard disc degeneration. Objective: The present study was aimed to investigate the protective effects of osteogenic protein-1 (OP-1) against NP cell apoptosis in an inflammation environment, and the potential signaling transduction pathway. Methods: Rat NP cells were cultured in medium with or without inflammatory cytokine tumor necrosis factor (TNF)-α for 6 days. The exogenous TNF-α was added into the medium to investigate its protective effects. NP cell apoptosis was evaluated by cell apoptosis ratio, caspase-3 activity, gene/protein expression of apoptosis-related molecules (Bcl-2, Bax, and caspase-3). Additionally, the intracellular reactive oxygen species (ROS) content and activity of the NF-κB pathway were also analyzed. Results: Compared with the control NP cells, TNF-α significantly increased cell apoptosis ratio, caspase-3 activity, gene/protein expression of Bcl-2, Bax and caspase-3, ROS content, and activity of the NF-κB pathway. However, OP-1 partly attenuated these effects in NP cells treated with TNF-α. Conclusion: OP-1 is effective in attenuating TNF-α-caused NP cell apoptosis, and the ROS/NF-κB pathway may be the potential signaling transduction pathway. The present study indicates that OP-1 may be helpful to inhibit inflammation-mediated disc degeneration.


2020 ◽  
Vol 40 (7) ◽  
Author(s):  
Lianglong Pang ◽  
Keshi Yang ◽  
Zhi Zhang

Abstract Diabetes mellitus (DM) is an important risk factor of intervertebral disc degeneration. However, how DM affects annulus fibrosus (AF) biology remains unclear. The present study was aimed to investigate the effects and mechanism of high glucose on AF cell biology. Rat AF cells were cultured in baseline medium and culture medium with 0.2 M glucose. The inhibitor 4-PBA was added along with the high glucose culture medium to study the role of endoplasmic reticulum (ER) stress in this process. Compared with the control cells, high glucose significantly increased cell apoptosis ratio and caspase-3/9 activity, up-regulated mRNA/protein expression of Bax and caspase-3/cleaved caspase-3, but down-regulated mRNA/protein expression of Bcl-2. Moreover, high glucose increased mRNA and protein expression of CHOP, ATF-6 and GRP78. However, once ER stress was inhibited by the inhibitor 4-PBA in the high glucose group, cell apoptosis ratio and caspase-3/9 activity were decreased, mRNA/protein expression of Bax and caspase-3/cleaved caspase-3 was down-regulated, but mRNA/protein expression of Bcl-2 was up-regulated. In conclusion, high glucose condition can promote AF cell apoptosis through inducing ER stress. The present study helps us understand the mechanism of disc degeneration in DM patients.


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.


2019 ◽  
Vol 39 (3) ◽  
Author(s):  
Qing Xu ◽  
Haolin Fang ◽  
Liang Zhao ◽  
Cunxin Zhang ◽  
Luo Zhang ◽  
...  

Abstract Mechanical overload is a risk factor of disc degeneration. It can induce disc degeneration through mediating cell apoptosis. Mechano growth factor (MGF) has been reported to inhibit mechanical overload-induced apoptosis of chondrocytes. The present study is aimed to investigate whether MGF can attenuate mechanical overload-induced nucleus pulposus (NP) cell apoptosis and the possible signaling transduction pathway. Rat NP cells were cultured and subjected to mechanical overload for 7 days. The control NP cells did not experience mechanical load. The exogenous MGF peptide was added into the culture medium to investigate its protective effects. NP cell apoptosis ratio, caspase-3 activity, gene expression of Bcl-2, Bax and caspase-3, protein expression of cleaved caspase-3, cleaved PARP, Bax and Bcl-2 were analyzed to evaluate NP cell apoptosis. In addition, activity of the p38 MAPK pathway was also detected. Compared with the control NP cells, mechanical overload significantly increased NP cell apoptosis and caspase-3 activity, up-regulated gene/protein expression of pro-apoptosis molecules (i.e. Bax, caspase-3, cleaved caspase-3 and cleaved PARP) whereas down-regulated gene/protein expression of anti-apoptosis molecule (i.e. Bcl-2). However, exogenous MGF partly reversed these effects of mechanical overload on NP cell apoptosis. Further results showed that activity of the p38 MAPK pathway of NP cells cultured under mechanical overload was decreased by addition of MGF peptide. In conclusion, MGF is able to attenuate mechanical overload-induced NP cell apoptosis, and the p38 MAPK signaling pathway may be involved in this process. The present study provides that MGF supplementation may be a promising strategy to retard mechanical overload-induced disc degeneration.


2018 ◽  
Vol 38 (2) ◽  
Author(s):  
Haolin Fang ◽  
Xianzhou Li ◽  
Haiming Shen ◽  
Buwei Sun ◽  
Haijun Teng ◽  
...  

Disc degeneration is correlated with mechanical load. Osteogenic protein-1 (OP-1) is potential to regenerate degenerative disc. To investigate whether OP-1 can protect against high magitude compression-induced nucleus pulposus (NP) cell apoptosis and NP matrix catabolism, and its potential mechanism; porcine discs were cultured in a bioreactor and compressed at a relatively high-magnitude mechanical compression (1.3 MPa at a frequency of 1.0 Hz for 2 h once per day) for 7 days. OP-1 was added along with the culture medium to investigate the protective effects of OP-1. NP cell apoptosis and matrix biosynthesis were evaluated. Additionally, activity of the p38 MAPK pathway is also analyzed. Compared with the control group, high magnitude compression significantly promoted NP cell apoptosis and decreased NP matrix biosynthesis, reflected by the increase in the number of terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL)-positive cells and caspase-3 activity, the up-regulated expression of Bax and caspase-3 mRNA and down-regulated expression of Bcl-2 mRNA, and the decreased Alcian Blue staining intensity and expression of matrix proteins (aggrecan and collagen II). However, OP-1 addition partly attenuated the effects of high magnitude compression on NP cell apoptosis and NP matrix biosynthesis. Further analysis showed that inhibition of the p38 MAPK pathway partly participated in this process. OP-1 can attenuate high magnitude compression-induced NP cell apoptosis and promoted NP matrix biosynthesis, and inhibition of the p38 MAPK pathway may participate in this regulatory process. The present study provides that OP-1 may be efficient in retarding mechanical overloading-exacerbated disc degeneration.


2017 ◽  
Vol 44 (1) ◽  
pp. 229-239 ◽  
Author(s):  
Pei Li ◽  
Zherui Liang ◽  
Gang Hou ◽  
Lei Song ◽  
Ruijie Zhang ◽  
...  

Background/Aims: Mechanical overloading-induced nucleus pulposus (NP) apoptosis plays an important role in the pathogenesis of intervertebral disc degeneration. N-cadherin (N-CDH)-mediated signaling preserves normal NP cell phenotype. This study aims to investigate the effects of N-CDH on NP cell apoptosis under high-magnitude compression and the underlying mechanism behind this process. Methods: Rat NP cells seeded on scaffold were perfusion-cultured using a self-developed perfusion bioreactor for 5 days and experienced different magnitudes (2% and 20% compressive deformation, respectively) of compression at a frequency of 1.0 Hz for 4 hours once per day. The un-loaded NP cells were used as controls. Lentivirus-mediated N-CDH overexpression and inhibitor LY294002 were used to further investigate the role of N-CDH and PI3K/Akt pathway under high-magnitude compression, respectively. NP cell apoptosis was evaluated by caspase-3 activity measured using a commercial kit, flow cytometry, and expression of apoptosis-related molecules analyzed by real-time PCR and western blotting assays. Results: High-magnitude compression significantly increased apoptotic NP cells, caspase-3 activity and expression of pro-apoptotic molecules (Bax and caspase-3/cleaved caspase-3), but decreased expression of anti-apoptotic molecule (Bcl-2). High-magnitude compression decreased expression of N-CDH, p-Akt and p-GSK-3β. However, N-CDH overexpression attenuated NP cell apoptosis and increased expression of p-Akt and p-GSK-3β under high-magnitude compression. Further analysis showed that inhibition of the PI3K/Akt pathway suppressed NP cell apoptosis and decreased expression of p-GSK-3β, but had no significant effects on N-CDH expression under high-magnitude compression. Conclusion: N-CDH can attenuate NP cell apoptosis through activating the PI3K/Akt-GSK-3β signaling under high-magnitude compression.


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