scholarly journals LncRNA GAS5 as miR-26a-5p Sponge Regulates the PTEN/PI3K/Akt Axis and Affects Extracellular Matrix Synthesis in Degenerative Nucleus Pulposus Cells in vitro

2021 ◽  
Vol 12 ◽  
Author(s):  
Liang Tan ◽  
Yifang Xie ◽  
Ye Yuan ◽  
Kai Hu
Keyword(s):  
Extracellular Matrix ◽  
Nucleus Pulposus ◽  
Intervertebral Disc Degeneration ◽  
Nucleus Pulposus Cell ◽  
Nucleus Pulposus Cells ◽  
Akt Inhibitor ◽  
Matrix Synthesis ◽  
Lncrna Gas5

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.

scholarly journals Oxidative Stress Aggravates Apoptosis of Nucleus Pulposus Cells through m6A Modification of MAT2A Pre-mRNA by METTL16

2022 ◽  
Vol 2022 ◽  
pp. 1-15
Author(s):  
Peng-Bo Chen ◽  
Gui-Xun Shi ◽  
Tao Liu ◽  
Bo Li ◽  
Sheng-Dan Jiang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Animal Model ◽  
Pilot Study ◽  
Nucleus Pulposus ◽  
Intervertebral Disc Degeneration ◽  
Nucleus Pulposus Cell ◽  
Nucleus Pulposus Cells ◽  
Human Npcs

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.

scholarly journals Dynamic Compression Promotes the Matrix Synthesis of Nucleus Pulposus Cells Through Up-Regulating N-CDH Expression in a Perfusion Bioreactor Culture

2018 ◽  
Vol 46 (2) ◽  
pp. 482-491 ◽  
Author(s):  
Yichun Xu ◽  
Hui Yao ◽  
Pei Li ◽  
Wenbin Xu ◽  
Junbin Zhang ◽  
...  
Keyword(s):  
Nucleus Pulposus ◽  
Dynamic Compression ◽  
Akt Pathway ◽  
Bioreactor Culture ◽  
Nucleus Pulposus Cells ◽  
Matrix Synthesis ◽  
Static Compression ◽  
Matrix Deposition ◽  
The Matrix

Background/Aims: An adequate matrix production of nucleus pulposus (NP) cells is an important tissue engineering-based strategy to regenerate degenerative discs. Here, we mainly aimed to investigate the effects and mechanism of mechanical compression (i.e., static compression vs. dynamic compression) on the matrix synthesis of three-dimensional (3D) cultured NP cells in vitro. Methods: Rat NP cells seeded on small intestinal submucosa (SIS) cryogel scaffolds were cultured in the chambers of a self-developed, mechanically active bioreactor for 10 days. Meanwhile, the NP cells were subjected to compression (static compression or dynamic compression at a 10% scaffold deformation) for 6 hours once per day. Unloaded NP cells were used as controls. The cellular phenotype and matrix biosynthesis of NP cells were investigated by real-time PCR and Western blotting assays. Lentivirus-mediated N-cadherin (N-CDH) knockdown and an inhibitor, LY294002, were used to further investigate the role of N-CDH and the PI3K/Akt pathway in this process. Results: Dynamic compression better maintained the expression of cell-specific markers (keratin-19, FOXF1 and PAX1) and matrix macromolecules (aggrecan and collagen II), as well as N-CDH expression and the activity of the PI3K/Akt pathway, in the 3D-cultured NP cells compared with those expression levels and activity in the cells grown under static compression. Further analysis showed that the N-CDH knockdown significantly down-regulated the expression of NP cell-specific markers and matrix macromolecules and inhibited the activation of the PI3K/Akt pathway under dynamic compression. However, inhibition of the PI3K/Akt pathway had no effects on N-CDH expression but down-regulated the expression of NP cell-specific markers and matrix macromolecules under dynamic compression. Conclusion: Dynamic compression increases the matrix synthesis of 3D-cultured NP cells compared with that of the cells under static compression, and the N-CDH-PI3K/Akt pathway is involved in this regulatory process. This study provides a promising strategy to promote the matrix deposition of tissue-engineered NP tissue in vitro prior to clinical transplantation.

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 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
Keyword(s):  
Growth Factor ◽  
Mouse Model ◽  
Intervertebral Disc ◽  
Nucleus Pulposus ◽  
Disc Degeneration ◽  
Intervertebral Disc Degeneration ◽  
Ex Vivo ◽  
Tissue Growth ◽  
Nucleus Pulposus Cells

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.

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.

scholarly journals CGRP Regulates Nucleus Pulposus Cell Apoptosis and Inflammation via the MAPK/NF-κB Signaling Pathways during Intervertebral Disc Degeneration

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Kaiqiang Sun ◽  
Jian Zhu ◽  
Chen Yan ◽  
Fudong Li ◽  
Fanqi Kong ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Signaling Pathways ◽  
Nucleus Pulposus ◽  
Disc Degeneration ◽  
Intervertebral Disc Degeneration ◽  
Nucleus Pulposus Cell ◽  
Mapk Signaling ◽  
Discogenic Pain

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.

miR-338-3p inhibits HIF-1α to Attenuate Nucleus Pulposus Cell Proliferation and Promote Apoptosis Through the Hippo-YAP Pathway

2021 ◽  
Author(s):  
Daolu Zhan ◽  
Jian Liu ◽  
Mingxia Lin ◽  
Jian Chen ◽  
Yehan Fang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Nucleus Pulposus ◽  
Intervertebral Disc Degeneration ◽  
Nucleus Pulposus Cell ◽  
Luciferase Assay ◽  
Ki 67 ◽  
Pathway Activation ◽  
Proliferation And Apoptosis ◽  
Related Proteins

Abstract The proliferation and apoptosis of nucleus pulposus (NP) cells (NPCs) play a crucial role in intervertebral disc degeneration (IDD). we aimed to discover the role of miRNA-induced IDD. We analyzed the miRNA expression of three NP tissues from IDD patients and three normal NP samples using the GEO2R tool, and The results revealed that miR-338-3p was upregulated in NPCs from IDD patients. miR-338-3p suppressed NPCs proliferation, and the related proteins PCNA and Ki-67 were downregulated, as demonstrated via western blotting. miR-338-3p promoted apoptosis. Furthermore, we predicted that HIF-1α was targeted by miR-338-3p, using the miRDB database, and this target was validated via dual luciferase assay. HIF-1α reversed miR-338-3p-induced NPCs proliferation and apoptosis. The Hippo-YAP pathway activation proteins YAP, CTGF, and PCNA were upregulated, unlike the inhibitory YAP phosphorylation. In conclusions, our results suggestive that miR-338-3p inhibited HIF-1α/ Hippo-YAP pathway to attenuate NPCs proliferation and apoptosis.

The expression of Fas ligand on normal and stabbed-disc cells in a rabbit model of intervertebral disc degeneration: a possible pathogenesis

2007 ◽  
Vol 6 (5) ◽  
pp. 425-430 ◽  
Author(s):  
Jing Wang ◽  
Tiansi Tang ◽  
Huilin Yang ◽  
Xiaoshen Yao ◽  
Liang Chen ◽  
...  
Keyword(s):  
Nucleus Pulposus ◽  
Intervertebral Disc Degeneration ◽  
Fas Ligand ◽  
Rabbit Model ◽  
Nucleus Pulposus Cells ◽  
Physiological Barrier ◽  
Disc Cells ◽  
The Mean ◽  
Privileged Site

Object The nucleus pulposus has been reported to be an immunologically privileged site. The expression of Fas ligand (FasL) on normal and herniated lumbar disc cells has been reported. The relationship between a physiological barrier and the role of FasL has not yet been addressed. To clarify this relationship and to investigate a possible pathogenesis of intervertebral disc degeneration (IDD), the expression of Fas and FasL (a mean apoptosis index) on normal and stabbed-disc cells was examined in a rabbit model of IDD. Methods Using defined needle gauges and depths, the anular puncture model of IDD was established in rabbits. The normal and stabbed discs were harvested at 3, 6, and 10 weeks after surgery. Immunohistochemical staining of these discs for Fas and FasL was performed using standard procedures. The mean apoptosis indices of the disc cells were determined using flow cytometry analysis. The nucleus pulposus cells from the normal discs exhibited relatively weak immunopositivity, whereas the nucleus pulposus cells from the stabbed discs exhibited strong immunopositivity. There was a significant difference (p < 0.001) in the percentage of FasL-positive nucleus pulposus cells between the normal discs and the stabbed discs. The mean apoptosis indices of the stabbed-disc cells at 3, 6, and 10 weeks poststab were significantly higher than those in normal disc cells (p < 0.001, 0.002, and 0.006, respectively). There was a significant correlation between the degree of FasL-positive expression and the degree of Fas-positive expression of the nucleus pulposus cells poststab (r = 0.571, p = 0.0036). Conclusions These observations indicate that the nucleus pulposus is an immunologically privileged site. This immunological privilege is maintained by FasL and the physiological barrier together. When the physiological barrier was damaged (by stabbing the disc), the role of FasL changed, and FasL was coexpressed with Fas to induce apoptosis of disc cells. These results indicate that an autoimmune reaction may be a possible pathogenesis of IDD.

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