Hyper-osmolarity environment-induced oxidative stress injury promotes nucleus pulposus cell senescence in vitro

Abstract Nucleus pulposus (NP) cell senescence is involved in disc degeneration. The in situ osmolarity within the NP region is an important regulator of disc cell’s biology. However, its effects on NP cell senescence remain unclear. The present study was aimed to investigate the effects and mechanism of hyper-osmolarity on NP cell senescence. Rat NP cells were cultured in the in situ-osmolarity medium and hyper-osmolarity medium. The reactive oxygen species (ROS) scavenger N-acetylcysteine (NAC) was added along with the medium to investigate the role of oxidative injury. Cell cycle, cell proliferation, senescence associated β-galactosidase (SA-β-Gal) activity, telomerase activity, expression of senescence markers (p16 and p53) and matrix molecules (aggrecan and collagen II) were tested to assess NP cell senescence. Compared with the in situ-osmolarity culture, hyper-osmolarity culture significantly decreased cell proliferation and telomerase activity, increased SA-β-Gal activity and cell fraction in the G0/G1 phase, up-regulated expression of senescence markers (p16 and p53) and down-regulated expression of matrix molecules (aggrecan and collagen II), and increased intracellular ROS accumulation. However, addition of NAC partly reversed these effects of hyper-osmolarity culture on cellular senescence and decreased ROS content in NP cells. In conclusion, a hyper-osmolarity culture promotes NP cell senescence through inducing oxidative stress injury. The present study provides new knowledge on NP cell senescence and helps us to better understand the mechanism of disc degeneration.

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N-Cadherin Attenuates High Glucose-Induced Nucleus Pulposus Cell Senescence Through Regulation of the ROS/NF-κB Pathway

Cellular Physiology and Biochemistry ◽

10.1159/000489804 ◽

2018 ◽

Vol 47 (1) ◽

pp. 257-265 ◽

Cited By ~ 6

Author(s):

Gang Hou ◽

Huiqing Zhao ◽

Haijun Teng ◽

Pei Li ◽

Wenbin Xu ◽

...

Keyword(s):

Cell Proliferation ◽

Nucleus Pulposus ◽

Western Blotting ◽

High Glucose ◽

Culture Medium ◽

Telomerase Activity ◽

Cell Senescence ◽

Cell Phenotype ◽

P53 Expression ◽

Pathway Activity

Background/Aims: Diabetes mellitus (DM) is a potential etiology of disc degeneration. N-cadherin (N-CDH) helps maintain the cell viability, cell phenotype and matrix biosynthesis of nucleus pulposus (NP) cells. Here, we mainly aimed to investigate whether N-CDH can attenuate high glucose-induced NP cell senescence and its potential mechanism. Methods: Rat NP cells were cultured in a base culture medium and base culture medium with a 0.2 M glucose concentration. Recombinant lentiviral vectors were used to enhance N-CDH expression in NP cells. Senescence-associated β-galactosidase (SA-β-Gal) activity was measured by SA-β-Gal staining. NP cell proliferation was evaluated by CCK-8 assay. Telomerase activity and intracellular reactive oxygen species (ROS) content were tested by specific chemical kits according to the manufacturer’s instructions. G0/G1 cell cycle arrest was evaluated by flow cytometry. Real-time PCR and Western blotting were used to analyze mRNA and protein expressions of senescence markers (p16 and p53) and matrix macromolecules (aggrecan and collagen II). Additionally, p-NF-κB expression was also analyzed by Western blotting to evaluate NF-κB pathway activity. Results: High glucose significantly decreased N-CDH expression, increased ROS generation and NF-κB pathway activity, and promoted NP cell senescence, which was reflected in the increase in SA-β-Gal activity and senescence marker (p16 and p53) expression, compared to the control group. High glucose decreased telomerase activity and cell proliferation potency. However, N-CDH overexpression partially attenuated NP cell senescence, decreased ROS content and inhibited the activation of the NF-κB pathway under the high glucose condition. Conclusion: High glucose decreases N-CDH expression and promotes NP cell senescence. N-CDH overexpression can attenuate high glucose-induced NP cell senescence through the regulation of the ROS/ NF-κB pathway. This study suggests that N-CDH is a potential therapeutic target to slow DM-mediated disc NP degeneration.

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Fermented Chinese Formula Shuan-Tong-Ling Protects Brain Microvascular Endothelial Cells against Oxidative Stress Injury

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2016/5154290 ◽

2016 ◽

Vol 2016 ◽

pp. 1-13 ◽

Cited By ~ 3

Author(s):

Lingjing Tan ◽

Xiang Zhang ◽

Zhigang Mei ◽

Jinfeng Wang ◽

Xiaoli Li ◽

...

Keyword(s):

Oxidative Stress ◽

Cell Proliferation ◽

Endothelial Cells ◽

Cell Senescence ◽

Microvascular Endothelial Cells ◽

Dependent Manner ◽

Brain Microvascular Endothelial Cells ◽

Stress Injury ◽

Oxidative Stress Injury ◽

Microvascular Endothelial

Fermented Chinese formulaShuan-Tong-Ling(STL), composed of fourteen medicinal herbs, was an experiential formula by Dr. Zhigang Mei for treating vascular encephalopathy, but the underlying mechanisms remained unknown. In this study, we aimed to investigate the protective effects of fermented STL on hydrogen peroxide- (H2O2-) induced injury in rat brain microvascular endothelial cells (BMECs) and the possible mechanisms. Cultured BMECs were treated with H2O2, STL, or nicotinamide (NAM, a SIRT1 inhibitor). Then, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was employed to detect cell proliferation and senescence-associated beta-galactosidase (SA-β-gal) was used to examine cell senescence. Cell nuclei were observed by 4′,6-diamidino-2-phenylindole. Additionally, changes in reactive oxygen species (ROS), superoxide dismutase (SOD), and glutathione (GSH) levels were measured. Expression of SIRT1, p21, and PGC-1αwas determined by western blot. Cell proliferation significantly increased with STL treatment in a dose-dependent manner. H2O2treatment could intensify cell senescence and nuclei splitting or pyknosis. With STL treatment, the reduced ROS level was accompanied by increased SOD and GSH activity. Further assays showed upregulation of SIRT1 and PGC-1αand downregulation of p21 after STL treatment. The results revealed that STL could protect BMECs against oxidative stress injury at least partially through the SIRT1 pathway.

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Extensive mechanical tension promotes annulus fibrosus cell senescence through suppressing cellular autophagy

Bioscience Reports ◽

10.1042/bsr20190163 ◽

2019 ◽

Vol 39 (4) ◽

Cited By ~ 2

Author(s):

Liang Zhao ◽

Baofang Tian ◽

Qing Xu ◽

Cunxin Zhang ◽

Luo Zhang ◽

...

Keyword(s):

Cell Proliferation ◽

Protein Expression ◽

Disc Degeneration ◽

Cell Biology ◽

Annulus Fibrosus ◽

Mechanical Load ◽

Telomerase Activity ◽

Cell Senescence ◽

Mechanical Tension ◽

Cellular Autophagy

Abstract Background: Mechanical load contributes a lot to the initiation and progression of disc degeneration. Annulus fibrosus (AF) cell biology under mechanical tension remains largely unclear. Objective: The present study was aimed to investigate AF cell senescence under mechanical tension and the potential role of autophagy. Methods: Rat AF cells were cultured and experienced different magnitudes (5% elongation and 20% elongation) of mechanical tension for 12 days. Control AF cells were kept static. Cell proliferation, telomerase activity, cell cycle fraction, and expression of senescence-related molecules (p16 and p53) and matrix macromolecules (aggrecan and collagen I) were analyzed to evaluate cell senescence. In addition, expression of Beclin-1 and LC3, and the ratio of LC3-II to LC3-I were analyzed to investigate cell autophagy. Results: Compared with the control group and 5% tension group, 20% tension group significantly decreased cell proliferation potency and telomerase activity, increased G1/G0 phase fraction, and up-regulated gene/protein expression of p16 and p53, whereas down-regulated gene/protein expression of aggrecan and collagen I. In addition, autophagy-related parameters such as gene/protein expression of Beclin-1 and LC3, and the ratio of LC3-II to LC3-I, were obviously suppressed in the 20% tension group. Conclusion: High mechanical tension promotes AF cell senescence though suppressing cellular autophagy. The present study will help us to better understand AF cell biology under mechanical tension and mechanical load-related disc degeneration.

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GSE4, a Small Dyskerin- and GSE24.2-Related Peptide, Induces Telomerase Activity, Cell Proliferation and Reduces DNA Damage, Oxidative Stress and Cell Senescence in Dyskerin Mutant Cells

PLoS ONE ◽

10.1371/journal.pone.0142980 ◽

2015 ◽

Vol 10 (11) ◽

pp. e0142980 ◽

Cited By ~ 7

Author(s):

Laura Iarriccio ◽

Cristina Manguán-García ◽

Laura Pintado-Berninches ◽

José Miguel Mancheño ◽

Antonio Molina ◽

...

Keyword(s):

Oxidative Stress ◽

Cell Proliferation ◽

Dna Damage ◽

Telomerase Activity ◽

Cell Senescence ◽

Related Peptide ◽

Mutant Cells

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Expression of miR-195 and its target gene Bcl-2 in human intervertebral disc degeneration and their effects on nucleus pulposus cell apoptosis

Journal of Orthopaedic Surgery and Research ◽

10.1186/s13018-021-02538-8 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Xue-Lin Lin ◽

Zhao-Yun Zheng ◽

Qing-Shan Zhang ◽

Zhen Zhang ◽

You-Zhi An

Keyword(s):

Cell Proliferation ◽

Intervertebral Disc ◽

Nucleus Pulposus ◽

Disc Degeneration ◽

Rat Model ◽

Cell Apoptosis ◽

Intervertebral Disc Degeneration ◽

Target Gene ◽

Blank Group ◽

Tnf Α

Abstract Objective To investigate the expression of miR-195 and its target gene Bcl-2 in intervertebral disc degeneration (IVDD) and its effect on nucleus pulposus (NP) cell apoptosis. Methods The expressions of miR-195 and Bcl-2 in NP tissues of IVDD patients were quantified by qRT-PCR and western blotting, respectively. NP cells were divided into blank group, TNF-α group, TNF-α + miR-NC group, TNF-α + siBcl-2 group, and TNF-α + miR-195 inhibitors + siBcl-2 group. Cell proliferation was detected by MTT assay, cell apoptosis evaluated by flow cytometry, and mitochondrial membrane potential (MMP) tested by JC-1 staining. Moreover, the function of miR-195 on IVDD in vivo was investigated using a puncture-induced IVDD rat model. Results IVDD patients had significantly increased miR-195 expression and decreased Bcl-2 protein expression in NP tissues. The expression of miR-195 was negatively correlated with the expression of Bcl-2 in IVDD patients. Dual-luciferase reporter gene assay indicated that Bcl-2 was a target gene of miR-195. In comparison with blank group, TNF-α group showed decreased cell proliferation and MMP, increased cell apoptosis, upregulated expression of miR-195, Bax, and cleaved caspase 3, and downregulated Bcl-2 protein, while these changes were attenuated by miR-195 inhibitors. Additionally, siBcl-2 can reverse the protective effect of miR-195 inhibitors on TNF-α-induced NP cells. Besides, inhibition of miR-195 alleviated IVDD degeneration and NP cell apoptosis in the rat model. Conclusion MiR-195 was significantly upregulated in NP tissues of IVDD patients, and inhibition of miR-195 could protect human NP cells from TNF-α-induced apoptosis via upregulation of Bcl-2.

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