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 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 Ferroportin-Dependent Iron Homeostasis Protects against Oxidative Stress-Induced Nucleus Pulposus Cell Ferroptosis and Ameliorates Intervertebral Disc Degeneration In Vivo

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Saideng Lu ◽  
Yu Song ◽  
Rongjin Luo ◽  
Shuai Li ◽  
Gaocai Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Iron Overload ◽  
Intervertebral Disc Degeneration ◽  
Iron Homeostasis ◽  
Nuclear Translocation ◽  
Nucleus Pulposus Cell ◽  
Intracellular Iron ◽  
Human Npcs

Ferroptosis is a specialized form of regulated cell death that is charactered by iron-dependent lethal lipid peroxidation, a process associated with multiple diseases. However, its role in the pathogenesis of intervertebral disc degeneration (IVDD) is rarely investigated. This study is aimed at investigating the role of ferroptosis in oxidative stress- (OS-) induced nucleus pulposus cell (NPC) decline and the pathogenesis of IVDD and determine the underlying regulatory mechanisms. We used tert-butyl hydroperoxide (TBHP) to simulate OS conditions around human NPCs. Flow cytometry and transmission electron microscopy were used to identify ferroptosis, while iron assay kit, Perl’s staining, and western blotting were performed to assay the intracellular iron levels. A ferroportin- (FPN-) lentivirus and FPN-siRNA were constructed and used to explore the relationship between FPN, intracellular iron homeostasis, and ferroptosis. Furthermore, hinokitiol, a bioactive compound known to specifically resist OS and restore FPN function, was evaluated for its therapeutic role in IVDD both in vitro and in vivo. The results indicated that intercellular iron overload plays an essential role in TBHP-induced ferroptosis of human NPCs. Mechanistically, FPN dysregulation is responsible for intercellular iron overload under OS. The increase in nuclear translocation of metal-regulatory transcription factor 1 (MTF1) restored the function of FPN, abolished the intercellular iron overload, and protected cells against ferroptosis. Additionally, hinokitiol enhanced the nuclear translocation of MTF1 by suppressing the JNK pathway and ameliorated the progression of IVDD in vivo. Taken together, our results demonstrate that ferroptosis and FPN dysfunction are involved in the NPC depletion and the pathogenesis of IVDD under OS. To the best of our knowledge, this is the first study to demonstrate the protective role of FPN in ferroptosis of NPCs, suggesting its potential used as a novel therapeutic target against IVDD.

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.

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.

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