Role of the ERK1/2 pathway in osmolarity effects on nucleus pulposus cell apoptosis in a disc perfusion culture

2016 ◽  
Vol 35 (1) ◽  
pp. 86-92 ◽  
Author(s):  
Pei Li ◽  
Yibo Gan ◽  
Haoming Wang ◽  
Yuan Xu ◽  
Songtao Li ◽  
...  
Keyword(s):  
Nucleus Pulposus ◽  
Cell Apoptosis ◽  
Perfusion Culture ◽  
Nucleus Pulposus Cell

scholarly journals N-Cadherin-Mediated Activation of PI3K/Akt-GSK-3β Signaling Attenuates Nucleus Pulposus Cell Apoptosis Under High-Magnitude Compression

2017 ◽  
Vol 44 (1) ◽  
pp. 229-239 ◽  
Author(s):  
Pei Li ◽  
Zherui Liang ◽  
Gang Hou ◽  
Lei Song ◽  
Ruijie Zhang ◽  
...  
Keyword(s):  
Nucleus Pulposus ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Nucleus Pulposus Cell ◽  
Underlying Mechanism ◽  
Akt Pathway ◽  
Cell Phenotype ◽  
High Magnitude ◽  
Gsk 3Β

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.

scholarly journals Exosomes Derived from Bone Mesenchymal Stem Cells Alleviate Compression-Induced Nucleus Pulposus Cell Apoptosis by Inhibiting Oxidative Stress

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yiqiang Hu ◽  
Ranyang Tao ◽  
Linfang Wang ◽  
Lang Chen ◽  
Ze Lin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Nucleus Pulposus ◽  
Cell Apoptosis ◽  
Nucleus Pulposus Cell ◽  
Inhibitory Effect ◽  
Bone Mesenchymal Stem Cells ◽  
Induced Apoptosis ◽  
Ivd Degeneration

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.

scholarly journals The resistant effect of SIRT1 in oxidative stress-induced senescence of rat nucleus pulposus cell is regulated by Akt-FoxO1 pathway

2019 ◽  
Vol 39 (5) ◽  
Author(s):  
Junsheng He ◽  
Ailiang Zhang ◽  
Zhiwen Song ◽  
Shiwu Guo ◽  
Yuwei Chen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nucleus Pulposus ◽  
Intervertebral Disc Degeneration ◽  
Nucleus Pulposus Cell ◽  
Sublethal Concentration ◽  
Action Mechanism ◽  
Protein Levels ◽  
Signaling Axis ◽  
Silent Information Regulator 1

Abstract Objective: The senescence of nucleus pulposus (NP) cells induced by oxidative stress is one of the important causes of intervertebral disc degeneration (IDD). Herein, we investigated the role and action mechanism of silent information regulator 1 (SIRT1) in oxidative stress-induced senescence of rat NP cell. Methods: Premature senescence of rat NP cells was induced by sublethal concentration of hydrogen peroxide (H2O2) (100 μM). SIRT1 was activated with SRT1720 (5 μM) to explore its effect on NP cells senescence. FoxO1 and Akt were inhibited by AS1842856 (0.2 μM) and MK-2206 (5 μM), respectively, to explore the role of Akt-FoxO1-SIRT1 axis in rat NP cells. Pretreatment with the resveratrol (20 μM), a common antioxidant and indirect activator of SIRT1, was done to investigate its role in senescent rat NP cells. Results: The mRNA and protein levels of SIRT1 were decreased in H2O2-induced senescent rat NP cells, and that specific activation of SIRT1 suppresses senescence. And the Akt-FoxO1 pathway, as the upstream of SIRT1, might be involved in the regulation of H2O2-induced senescence of rat NP cells by affecting the expression of SIRT1. In addition, the resveratrol played an anti-senescence role in rat NP cells, which might affect the Akt-FoxO1-SIRT1 axis. Conclusion: SIRT1 ameliorated oxidative stress-induced senescence of rat NP cell which was regulated by Akt-FoxO1 pathway, and resveratrol exerted anti-senescence effects by affecting this signaling axis.

scholarly journals Melatonin Protects Intervertebral Disc from Degeneration by Improving Cell Survival and Function via Activation of the ERK1/2 Signaling Pathway

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Jun Ge ◽  
Quan Zhou ◽  
Junjie Niu ◽  
Yingjie Wang ◽  
Qi Yan ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Intervertebral Disc ◽  
Signaling Pathway ◽  
Nucleus Pulposus ◽  
Disc Degeneration ◽  
Intervertebral Disc Degeneration ◽  
Nucleus Pulposus Cell ◽  
Cell Physiology ◽  
Cell Degeneration

Melatonin, a neuroendocrine hormone secreted by the pineal body, has a positive effect on intervertebral disc degeneration. The present study is aimed at investigating the biological role of melatonin in intervertebral disc degeneration and its underlying mechanism. A human nucleus pulposus cell (NPC) line was exposed to melatonin at different concentrations. Cell proliferation was measured by CCK-8 assay. Cell cycle and apoptosis were analyzed by flow cytometry. Western blot was performed to measure the protein expression of indicated genes. A rabbit model of intervertebral disc degeneration was established to detect the role and mechanism of melatonin on intervertebral disc degeneration. Our study showed that melatonin promoted NPC viability and inhibited cell arrest. Furthermore, melatonin treatment led to the upregulation of collagen II and aggrecan and downregulation of collagen X. Moreover, melatonin significantly elevated the activity of the ERK signaling pathway. Inhibition of the ERK1/2 signals reversed the role of melatonin in the regulation of NPCs both in vitro and in vivo. Melatonin increased NPC viability through inhibition of cell cycle arrest and apoptosis. Moreover, melatonin promoted the secretion of functional factors influencing the nucleus pulposus cell physiology and retarded cell degeneration. Our results suggest that melatonin activated the ERK1/2 signaling pathway, thereby affecting the biological properties of the intervertebral disc degeneration.

scholarly journals MiR-502 Suppresses TNF-α-Induced Nucleus Pulposus Cell Apoptosis by Targeting TARF2

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zhao Guo ◽  
Wen-Shan Gao ◽  
Yun-Fei Wang ◽  
Fei Gao ◽  
Wei Wang ◽  
...  
Keyword(s):  
Nucleus Pulposus ◽  
Cell Injury ◽  
Nucleus Pulposus Cell ◽  
Luciferase Reporter ◽  
Luciferase Reporter Gene ◽  
Tnf Α ◽  
Induced Apoptosis ◽  
Necrosis Factor

Intervertebral disc degeneration (IVDD) is a common cause of low back pain. This study is aimed at investigating the role of microRNAs (miRNAs) in regulating human nucleus pulposus (NP) cell injury induced by tumor necrosis factor- (TNF-) α in IVDD. In this study, we induced NP cells with 20 ng/mL TNF-α in vitro, which promoted the obvious apoptosis of NP cells and the activation of nuclear transcription factor (NF)-κB. In contrast, using the specific NF-κB inhibitor BAY 11-7082 to treat cells greatly impaired the activation of NF-κB and increased the sensitivity of NP cells to TNF-α-induced apoptosis. Moreover, both TNF-α and BAY 11-7082 treatments were associated with marked miRNA dysregulation, with miR-502 being upregulated by TNF-α treatment and downregulated by BAY 11-7082 treatment, respectively. And the overexpression of miR-502 enhanced NF-κB activation and suppressed apoptosis of human NP cells induced by TNF-α, whereas the opposite was observed following miR-502 inhibition. Last, through bioinformatic analyses and luciferase reporter gene experiments, we identified TRAF2, an important activator of NF-κB, as a miR-502 target gene. Similarly, siRNA-mediated knockdown of the TRAF2 expression also suppressed TNF-α-induced apoptosis and enhanced NF-κB activation. Our findings provide evidence indicating that miR-502 is a key regulator of apoptosis of human NP cells induced by TNF-α by targeting TRAF2 and activating NF-κB.

Sign in / Sign up

Export Citation Format

Share Document