scholarly journals Mechanical Stretch Induces Annulus Fibrosus Cell Senescence through Activation of the RhoA/ROCK Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Li Ning ◽  
Lei Gao ◽  
Fan Zhang ◽  
Xiaoxiao Li ◽  
Tingting Wang
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Annulus Fibrosus ◽  
Coiled Coil ◽  
Mechanical Stretch ◽  
Telomerase Activity ◽  
Cell Senescence ◽  
Central Nucleus ◽  
Biological Behavior ◽  
Signaling Transduction Pathway

Background. Intervertebral disc is responsible for absorbing and transmitting mechanical compression. Under physiological conditions, the peripheral annulus fibrosus (AF) cells are subjected to different magnitudes of transverse mechanical stretch depending on the swelling of the central nucleus pulposus tissue. However, the biological behavior of AF cells under mechanical stretch is not well studied. Objective. This study was performed to study the effects of mechanical tension on AF cell senescence and the potential signaling transduction pathway. Methods. Rat AF cells were made to experience different magnitudes of mechanical stretch (2% elongation and 20% elongation for 4 hours every day at 1 Hz) in a 10-day experiment period. The inhibitor RKI-1447 of the Rho-associated coiled-coil–containing protein kinases (ROCK) was added along with culture medium to investigate its role. Cell proliferation, cell cycle, telomerase activity, and expression of senescence markers (p16 and p53) were analyzed. Results. We found that 20% elongation significantly decreased cell proliferation, promoted G0/G1 cell cycle arrest, decreased telomerase activity, and upregulated mRNA/protein expression of p16 and p53. Moreover, the inhibitor RKI-1447 partly resisted effects of 20% elongation on these parameters of cell senescence. Conclusion. High mechanical stretch obviously induces AF cell senescence through the RhoA/ROCK pathway. This study provides us a deeper understanding on the AF cell’s behavior under mechanical stretch.

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

2019 ◽  
Vol 39 (4) ◽  
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.

scholarly journals Resveratrol attenuates inflammation environment-induced nucleus pulposus cell senescence in vitro

2019 ◽  
Vol 39 (5) ◽  
Author(s):  
Xiaoming Li ◽  
Feixiang Lin ◽  
Yaohong Wu ◽  
Ning Liu ◽  
Jun Wang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Protein Expression ◽  
Cell Cycle Arrest ◽  
Inflammatory Cytokine ◽  
Telomerase Activity ◽  
Cell Senescence ◽  
Control Group ◽  
Cycle Arrest ◽  
Inflammation Group

Abstract Intervertebral disc degeneration is a disease identified as an inflammation response-participated pathological process. As a classical cellular feature, disc cell senescence is reported to be closely related with disc cell senescence. Resveratrol has a protective role against inflammation in some cells. However, its biological effects on disc cells remain largely unclear. The present study was aimed to study the effects of resveratrol on disc nucleus pulposus (NP) cell senescence in an inflammation environment. Isolated NP cells were cultured in cultured medium with (control group) or without (inflammation group) inflammatory cytokine TNF-α and IL-1β for 14 days. Resveratrol was added along with the NP cells treated with inflammatory cytokines to investigate its effects. NP cell senescence was analyzed by senescence-associated β-Galactosidase (SA-β-Gal) staining, cell proliferation, G0/1 cell cycle arrest, telomerase activity, gene/protein expression of senescence markers (p16 and p53) and NP matrix biosynthesis. In addition, the intracellular reactive oxygen species (ROS) was also analyzed. Compared with the control group, inflammation group significantly increased SA-β-Gal activity and ROS content, decreased cell proliferation and telomerase activity, promoted G0/1 cell cycle arrest, up-regulated gene/protein expression of senescence markers (p16 and p53) and matrix catabolism enzymes (MMP-3, MMP-13 and ADAMTS-4), and down-regulated gene/protein expression of NP matrix macromolecules (aggrecan and collagen II). However, resveratrol partly reversed the effects of inflammatory cytokine on these cell senescence-associated parameters. Together, resveratrol was effective to suppress cell senescence in an inflammatory environment. The present study shows new knowledge on how to retard inflammation response-initiated disc degeneration.

Cyclic mechanical stretch inhibits cell proliferation and induces apoptosis in fetal rat lung fibroblasts

2002 ◽  
Vol 282 (3) ◽  
pp. L448-L456 ◽  
Author(s):  
Juan Sanchez-Esteban ◽  
Yulian Wang ◽  
Lawrence A. Cicchiello ◽  
Lewis P. Rubin
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Cycle Progression ◽  
Fetal Lung ◽  
Mechanical Stretch ◽  
Lung Fibroblasts ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Dna Flow Cytometry ◽  
Fetal Rat ◽  
Induced Apoptosis

Development of the pulmonary air sacs is crucial for extrauterine survival. Late fetal lung development is characterized by a thinning of the mesenchyme, which brings pneumocytes and endothelial cells into apposition. We hypothesized that mechanical stretch, simulating fetal breathing movements, plays an important role in this remodeling process. Using a Flexercell Strain Unit, we analyzed the effects of intermittent stretch on cell proliferation and apoptosis activation in fibroblasts isolated from fetal rat lungs during late development. On day 19, intermittent stretch increased cells in G0/G1 by 22% ( P = 0.001) and decreased in S phase by 50% ( P = 0.003) compared with unstretched controls. Cell proliferation analyzed by 5-bromo-2′-deoxyuridine incorporation showed a similar magnitude of cell cycle arrest ( P = 0.04). At this same gestational age, stretch induced apoptosis by two- to threefold over controls, assayed by DNA flow cytometry, terminal deoxynucleotidyl transferase-mediated dUTP-FITC nick-end labeling, and caspase-3 activation. These results indicate that mechanical stretch of fibroblasts isolated during the canalicular stage inhibits cell cycle progression and activates apoptosis. These findings are cotemporal with the mesenchymal thinning that normally occurs in situ.

scholarly journals Inhibition of Proliferation, Migration, and Invasion by Knockdown of Pyruvate Kinase-M2 (PKM2) in Ovarian Cancer SKOV3 and OVCAR3 Cells

2016 ◽  
Vol 24 (6) ◽  
pp. 463-475 ◽  
Author(s):  
Yi Miao ◽  
Meng Lu ◽  
Qin Yan ◽  
Shuangdi Li ◽  
Youji Feng
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Migration ◽  
Pyruvate Kinase ◽  
Biological Behavior ◽  
Phase Cell ◽  
Migration And Invasion ◽  
Cell Cycle Distribution ◽  
Inhibition Of Proliferation ◽  
Cell Migration And Invasion

Pyruvate kinase (PK) is a key enzyme in the process of glycolysis, catalyzing phosphoenolpyruvate (PEP) into pyruvate. Currently, PK isozyme type M2 (PKM2), one subtype of PK, has been proposed as a new tumor marker with high expression in various tumor tissues. Here we aimed to explore the effects of siRNA-PKM2 on ovarian carcinoma (OC) cell lines SKOV3 and OVCAR3, in which PKM2 was notably expressed. PKM2 gene interference lentivirus vectors were built by miRNA transfection assay. siRNA-PKM2-transfected SKOV3 and OVCAR3 cells were evaluated for cell proliferation, cell cycle distribution, cell apoptosis, cell migration, and invasion in this study. In addition, the expression levels of several tumor-related genes were measured using real-time PCR and Western blot. Results showed that siRNA-PKM2 markedly inhibited cell proliferation, induced apoptosis, and caused cell cycle arrest at the G0/G1 phase. Cell migration and invasion were significantly suppressed by siRNA-PKM2. Furthermore, the tumor-related genes caspase 7, Bad, and E-cadherin were upregulated, while MMP2, HIF1α, VEGF, and MMP9 were depressed by siRNA-PKM2. The function of siRNA-PKM2 on the biological behavior of OC cells indicated that PKM2 may also be a target for treatment of OC.

Goblet Cell Carcinoids of the Appendix

2001 ◽  
Vol 125 (3) ◽  
pp. 386-390 ◽  
Author(s):  
R. Kanthan ◽  
A. Saxena ◽  
S. C. Kanthan
Keyword(s):  
Electron Microscopy ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Goblet Cell ◽  
Cellular Proliferation ◽  
Lung Metastases ◽  
Periodic Acid ◽  
Biological Behavior ◽  
Periodic Acid Schiff ◽  
Proliferation Markers

Abstract Background.—Goblet cell carcinoids of the appendix are rare neoplasms with uncertain biological behavior. Objective.—The aims of our study were to evaluate the immunophenotype of this neoplasm with cell cycle/cell proliferation markers and to understand their histogenesis with ultrastructural analysis using conventional carcinoids as a frame of reference. Methods.—Clinical data and archival pathologic material of all goblet cell carcinoids of the appendix recorded by the Saskatchewan Cancer Registry between 1970 and 1998 were reviewed and evaluated by light microscopy, histochemistry, immunohistochemistry, and electron microscopy. Results.—Seven cases of goblet cell carcinoids were identified among 110 cases of conventional carcinoids of the appendix. Histopathology revealed widespread infiltration of the periappendiceal fat in all cases, with extensive perineural invasion. The cells stained strongly positive for mucicarmine, periodic acid–Schiff, periodic acid–Schiff diastase, Alcian blue, cytokeratin, and carcinoembryonic antigen. Most cases were positive for synaptophysin. Increased expression of cell proliferation markers and cell cycle markers was observed. Expression of p53 was strong in one case. Electron microscopy demonstrated the presence of mucinous vacuoles of varying sizes and occasional membrane-bound neuroendocrine granules. Conclusions.—Goblet cell carcinoids of the appendix arise from a pluripotent cell with divergent neuroendocrine and mucinous differentiation. These neoplasms are widely invasive; they demonstrate a high cellular proliferation rate and dysregulation of the cell cycle with up-regulation of cyclin D1 and p21, and down-regulation of p16. Complete removal of the tumor is recommended because of the unpredictable biological behavior of this tumor, which includes delayed local recurrences and lung metastases.

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

2018 ◽  
Vol 47 (1) ◽  
pp. 257-265 ◽  
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.

MicroRNA profiling analysis in a series of high-risk intestinal GISTs.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 10532-10532
Author(s):  
Silvia Calabuig ◽  
Javier Martin Broto ◽  
Dolors Sanchez-Izquierdo ◽  
Antonia Obrador ◽  
Luis Ortega ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
High Risk ◽  
Expression Profile ◽  
Rna Extraction ◽  
Differentially Expressed ◽  
Biological Behavior ◽  
P Values ◽  
Wide Range ◽  
Two Samples

10532 Background: Resected localized GISTs exhibit a wide range of biological behavior from low to high risk of recurrence. Risk categories (low, intermediate and high) are built from mitotic count, size and location. However, the molecular mechanism related to GIST relapse has not yet been fully clarified. The purpose of this study is to characterize miRNA expression profile in high risk GIST patients for both, recurred and not recurred, and detect those differentially expressed in these two subsets. Methods: Twelve cases of high risk intestinal GIST, 6 with relapse and 6 without relapse, were selected for this analysis. Sections were obtained for RNA extraction using the miRNeasy FFPE kit (Qiagen) and miRNA was hybridized to the GeneChip miRNA 3.0 Array (Affymetrix) including more than 1800 human miRNA. Normalization and statistical analysis were performed with Partek Genomic Suite 6.6 software by means of ANOVA test. Fold-change (FC) and p-values were applied to generate miRNA differentially expressed lists. Results: A subset of 85 miRNA were significantly deregulated (p<0.05; FC=1.5) when comparing both groups. Among them, the highest p-values and associated FC were: mir-4776 (FC= 1,95, p= 0,011;), mir-1973 (FC= 1,59, p= 0,014) mir-4649 (FC 1,74, p= 0,028) and mir-3605 (GC= 1,58, p=0,045). All of these were up-regulated in recurred patients. Interestingly, the two samples that correspond to the biggest tumors with relapse showed a significantly different expression profile that separated them from the rest of the samples. We have identified 44 miRNAs that discriminate these two samples from the rest and show a very high statistical significance. The most significantly up regulated miRNAs were miR-100 (FC= 90,87, p<0.0001), miR-30a (FC= 156,086, p<0.0001) and down regulated miR-1184 (FC= -24,94, p<0.0001) and miR-4529 (FC= -16,61, p<0.0001). These miRNAs are involved in cell cycle and cell proliferation. Conclusions: This is the first wide characterization of miRNA profile in high risk GIST. The highest differences in expression are related to not previously described miRNAs in GIST tumors. All of them are involved in cell cycle and cell proliferation, thus expecting to regulate many GISTs associated genes, related to the relapse event.

scholarly journals The miR-141/neuropilin-1 axis is associated with the clinicopathology and contributes to the growth and metastasis of pancreatic cancer

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Lixin Ma ◽  
Bo Zhai ◽  
Huaqiang Zhu ◽  
Weidong Li ◽  
Wenjing Jiang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Pancreatic Cancer ◽  
Cell Proliferation ◽  
Liver Metastasis ◽  
Tumor Growth ◽  
Biological Behavior ◽  
Therapeutic Effects ◽  
Mesenchymal Transition ◽  
Neuropilin 1 ◽  
Cancer Tissues

Abstract Background Neuropilin-1 (NRP-1) is a non-tyrosine kinase receptor interacting with multiple signaling pathways that underpin the biological behavior and fate of cancer cells. However, in pancreatic cancer, the mechanisms underlying the function of NRP-1 in cell proliferation and metastasis and the involvement of regulatory upstream miRNAs remain unclear. Methods Potential miRNAs were mined by using multiple bioinformatics prediction tools and validated by luciferase assays. The expression of NRP-1 and miRNA-141 (miR-141) in pancreatic tissues and cells was examined by immunohistochemistry, immunoblotting and/or real-time RT-PCR. Stable transfected cells depleted of NRP-1 were generated, and regulatory effects of miR-141 were investigated by transfecting cells with miR-141 mimics and anti-miR-141. Assays of cell viability, proliferation, cell cycle distribution, transwell migration and cell scratch were employed. Xenograft tumor models were established to assess the effects of NRP-1 depletion on tumorigenesis and liver metastasis, and therapeutic effects of miR-141 on tumor growth. The role of miR-141/NRP-1 axis in regulating epithelial–mesenchymal transition (EMT) by co-interacting the TGF-β pathway was examined. Results In this study, of 12 candidate miRNAs identified, miR-141 showed the strongest ability to regulate NRP-1. In pancreatic cancer tissues and cells, the expression level of NRP-1 was negatively correlated with that of miR-141. NRP-1 was highly expressed in pancreatic cancer tissues compared with normal pancreatic tissues, and its expression levels were positively correlated with tumor grade, lymph metastasis and AJCC staging. NRP-1 depletion inhibited cell proliferation by inducing cell cycle arrest at the G0/G1 phase through upregulating p27 and downregulating cyclin E and cyclin-dependent kinase 2, and reduced cell migration by inhibiting EMT through upregulating E-cadherin and downregulating Snail and N-cadherin. Through downregulating NRP-1, miR-141 mimics showed a similar effect as NRP-1 depletion on cell proliferation and migration. NRP-1 depletion suppressed tumor growth and liver metastasis and miR-141 mimics inhibited the growth of established tumors in mice. NRP-1 depletion and/or miR-141 mimics inhibited the activation of the TGF-β pathway stimulated by TGF-β ligand. Conclusions The present results indicate that NRP-1 is negatively regulated by miR-141 and the miR-141/NRP-1 axis may serve as potentially valuable biomarkers and therapeutic targets for pancreatic cancer.

scholarly journals Melatonin Inhibits Annulus Fibrosus Cell Senescence through Regulating the ROS/NF-κB Pathway in an Inflammatory Environment

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Jing Li ◽  
Jianghua Li ◽  
Chengzhang Cao ◽  
Jianhua Sun ◽  
Sibo Wang ◽  
...  
Keyword(s):  
Disc Degeneration ◽  
Annulus Fibrosus ◽  
Underlying Mechanism ◽  
Telomerase Activity ◽  
Cell Senescence ◽  
Oxygen Species ◽  
Protective Effects ◽  
Tnf Α ◽  
Factor Α ◽  
Necrosis Factor

Inflammation response is an important reason for disc cell senescence during disc degeneration. Recently, melatonin is suggested to protect against disc degeneration. However, the effects of melatonin on annulus fibrosus (AF) cell senescence are not fully studied. The main purpose of this study was to investigate the effects of melatonin on AF cell senescence in an inflammatory environment and the underlying mechanism. Rat disc AF cells were cultured in a medium with tumor necrosis factor-α (TNF-α). Melatonin was added along with the medium to observe its protective effects. Compared with the control AF cells, TNF-α significantly declined cell proliferation potency and telomerase activity, elevated senescence-associated β-galactosidase (SA-β-Gal) activity, upregulated protein expression of senescence markers (p16 and p53), and increased reactive oxygen species (ROS) content and activity of the NF-κB pathway. However, when the TNF-α-treated AF cells were incubated with melatonin, ROS content and activity of the NF-κB pathway were decreased, and those parameters reflecting cell senescence indicated that AF cell senescence was also partly alleviated. Together, melatonin suppresses AF cell senescence through regulating the ROS/NF-κB pathway in an inflammatory environment. This study sheds a new light that melatonin may be promising to retard inflammation-caused disc degeneration.

scholarly journals HnRNP F/H associate with hTERC and telomerase holoenzyme to modulate telomerase function and promote cell proliferation

2019 ◽  
Vol 27 (6) ◽  
pp. 1998-2013 ◽  
Author(s):  
Chenzhong Xu ◽  
Nan Xie ◽  
Yuanyuan Su ◽  
Zhaomeng Sun ◽  
Yao Liang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Stem Cell ◽  
Telomerase Activity ◽  
Cell Senescence ◽  
Promote Cell Proliferation ◽  
Associated Proteins ◽  
Hnrnp F ◽  
Human Telomerase

AbstractHuman telomerase RNA component hTERC comprises multiple motifs that contribute to hTERC biogenesis, holoenzyme activity, and enzyme recruitment to telomeres. hTERC contains several guanine tracts (G-tracts) at its 5′-end, but its associated proteins and potential roles in telomerase function are still poorly understood. The heterogeneous nuclear ribonucleoproteins F, H1, and H2 (hnRNP F/H) are splicing factors that preferentially bind to poly(G)-rich sequences RNA. Here, we demonstrate that hnRNP F/H associate with both hTERC and telomerase holoenzyme to regulate telomerase activity. We reveal hnRNP F/H bind to the 5′-end region of hTERC in vitro and in vivo, and identify the first three G-tracts of hTERC and qRRM1 domain of hnRNP F/H are required for their interaction. Furthermore, hnRNP F/H also directly interact with telomerase holoenzyme. Functionally, we show that hnRNP F/H plays important roles in modulating telomerase activity and telomere length. Moreover, hnRNP F/H deletion greatly impair cancer and stem cell proliferation, and induce stem cell senescence, while hnRNP F/H overexpression delay stem cell senescence. Collectively, our findings unveil a novel role of hnRNP F/H as the binding partners of hTERC and telomerase holoenzyme to regulate telomerase function.

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