scholarly journals N-Cadherin Maintains the Healthy Biology of Nucleus Pulposus Cells under High-Magnitude Compression

2017 ◽  
Vol 43 (6) ◽  
pp. 2327-2337 ◽  
Author(s):  
Zhenyu Wang ◽  
Jiali Leng ◽  
Yuguang Zhao ◽  
Dehai Yu ◽  
Feng Xu ◽  
...  
Keyword(s):  
Cell Viability ◽  
Nucleus Pulposus ◽  
Cell Biology ◽  
Mechanical Load ◽  
Cell Phenotype ◽  
Nucleus Pulposus Cells ◽  
Keratin 19 ◽  
High Magnitude ◽  
And Control

Background/Aims: Mechanical load can regulate disc nucleus pulposus (NP) biology in terms of cell viability, matrix homeostasis and cell phenotype. N-cadherin (N-CDH) is a molecular marker of NP cells. This study investigated the role of N-CDH in maintaining NP cell phenotype, NP matrix synthesis and NP cell viability under high-magnitude compression. Methods: Rat NP cells seeded on scaffolds were perfusion-cultured using a self-developed perfusion bioreactor for 5 days. NP cell biology in terms of cell apoptosis, matrix biosynthesis and cell phenotype was studied after the cells were subjected to different compressive magnitudes (low- and high-magnitudes: 2% and 20% compressive deformation, respectively). Non-loaded NP cells were used as controls. Lentivirus-mediated N-CDH overexpression was used to further investigate the role of N-CDH under high-magnitude compression. Results: The 20% deformation compression condition significantly decreased N-CDH expression compared with the 2% deformation compression and control conditions. Meanwhile, 20% deformation compression increased the number of apoptotic NP cells, up-regulated the expression of Bax and cleaved-caspase-3 and down-regulated the expression of Bcl-2, matrix macromolecules (aggrecan and collagen II) and NP cell markers (glypican-3, CAXII and keratin-19) compared with 2% deformation compression. Additionally, N-CDH overexpression attenuated the effects of 20% deformation compression on NP cell biology in relation to the designated parameters. Conclusion: N-CDH helps to restore the cell viability, matrix biosynthesis and cellular phenotype of NP cells under high-magnitude compression.

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.

Cell Morphology and Migration of Nucleus Pulposus Cells Depends on Substrate Stiffness and Ligand

2012 ◽  
Author(s):  
Priscilla Y. Hwang ◽  
Christopher L. Gilchrist ◽  
Aubrey T. Francisco ◽  
Jun Chen ◽  
Lori A. Setton
Keyword(s):  
Nucleus Pulposus ◽  
Cell Biology ◽  
Imaging Techniques ◽  
Matrix Proteins ◽  
Cell Phenotype ◽  
Nucleus Pulposus Cells ◽  
Cell Clustering ◽  
And Migration ◽  
And Function

Changes in nucleus pulposus (NP) cell phenotype and morphology are implicated in the progression of intervertebral disc (IVD) disorders. Understanding how changes in the NP cell microenvironment influence cell behavior and function is important for revealing how pathology-related changes in IVD extracellular matrix may affect NP cell biology. In this study, live-cell imaging techniques were utilized to study changes in cell migration and morphology when cultured upon substrates of different matrix proteins and stiffnesses. Results indicate that soft substrates containing matrix proteins promote cell clustering and cell-cell interactions which mimic in vivo conditions of healthy NP cells.

scholarly journals Optimization of Spheroid Colony Culture and Cryopreservation of Nucleus Pulposus Cells for the Development of Intervertebral Disc Regenerative Therapeutics

2021 ◽  
Vol 11 (8) ◽  
pp. 3309
Author(s):  
Kosuke Sako ◽  
Daisuke Sakai ◽  
Yoshihiko Nakamura ◽  
Erika Matsushita ◽  
Jordy Schol ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Viability ◽  
Nucleus Pulposus ◽  
Mass Culture ◽  
Formation Rate ◽  
Proliferation Rate ◽  
Cell Phenotype ◽  
Mrna Levels ◽  
Spheroid Formation ◽  
Positive Nucleus

After the discovery of functionally superior Tie2-positive nucleus pulposus (NP) progenitor cells, new methods were needed to enable mass culture and cryopreservation to maintain these cells in an undifferentiated state with high cell yield. We used six types of EZSPHERE® dishes, which support spheroid-forming colony culture, and examined NP cell spheroid-formation ability, number, proliferation, and mRNA expression of ACAN, COL1A2, COL2A1, and ANGPT1. Six different types of cryopreservation solutions were examined for potential use in clinical cryopreservation by comparing the effects of exposure time during cryopreservation on cell viability, Tie2-positivity, and cell proliferation rates. The spheroid formation rate was 45.1% and the cell proliferation rate was 7.75 times using EZSPHERE® dishes. The mRNA levels for COL2A1 and ANGPT1 were also high. In cryopreservation, CryoStor10 (CS10) produced ≥90% cell viability and a high proliferation rate after thawing. CS10 had a high Tie2-positive rate of 12.6% after culturing for 5 days after thawing. These results suggest that EZSPHERE enabled colony formation in cell culture without the use of hydrogel products and that CS10 is the best cryopreservation medium for retaining the NP progenitor cell phenotype and viability. Together, these data provide useful information of NP cell-based therapeutics to the clinic.

scholarly journals Resveratrol increases nucleus pulposus matrix synthesis through activating the PI3K/Akt signaling pathway under mechanical compression in a disc organ culture

2017 ◽  
Vol 37 (6) ◽  
Author(s):  
Xiaorui Han ◽  
Xiaoming Leng ◽  
Man Zhao ◽  
Mei Wu ◽  
Amei Chen ◽  
...  
Keyword(s):  
Nucleus Pulposus ◽  
Mechanical Load ◽  
Staining Intensity ◽  
Akt Pathway ◽  
Dependent Manner ◽  
Mechanical Compression ◽  
Matrix Synthesis ◽  
High Magnitude ◽  
Collagen Ii ◽  
Dose Dependent

Disc nucleus pulposus (NP) matrix homeostasis is important for normal disc function. Mechanical overloading seriously decreases matrix synthesis and increases matrix degradation. The present study aims to investigate the effects of resveratrol on disc NP matrix homeostasis under a relatively high-magnitude mechanical compression and the potential mechanism underlying this process. Porcine discs were perfusion-cultured and subjected to a relatively high-magnitude mechanical compression (1.3 MPa at a frequency of 1.0 Hz for 2 h once per day) for 7 days in a mechanically active bioreactor. The non-compressed discs were used as controls. Resveratrol was added along with culture medium to observe the effects of resveratrol on NP matrix synthesis under mechanical load respectively. NP matrix synthesis was evaluated by histology, biochemical content (glycosaminoglycan (GAG) and hydroxyproline (HYP)), and expression of matrix macromolecules (aggrecan and collagen II). Results showed that this high-magnitude mechanical compression significantly decreased NP matrix content, indicated by the decreased staining intensity of Alcian Blue and biochemical content (GAG and HYP), and the down-regulated expression of NP matrix macromolecules (aggrecan and collagen II). Further analysis indicated that resveratrol partly stimulated NP matrix synthesis and increased activity of the PI3K/Akt pathway in a dose-dependent manner under mechanical compression. Together, resveratrol is beneficial for disc NP matrix synthesis under mechanical overloading, and the activation of the PI3K/Akt pathway may participate in this regulatory process. Resveratrol may be promising to regenerate mechanical overloading-induced disc degeneration.

scholarly journals Non-viral reprogramming of human nucleus pulposus cells with FOXF1 via extracellular vesicle delivery: an in vitro and in vivo study

2021 ◽  
Vol 41 ◽  
pp. 90-107
Author(s):  
S Tang ◽  
◽  
A Salazar-Puerta ◽  
J Richards ◽  
S Khan ◽  
...  
Keyword(s):  
Nucleus Pulposus ◽  
Viral Vectors ◽  
Extracellular Vesicle ◽  
Proteoglycan Synthesis ◽  
Nucleus Pulposus Cells ◽  
Keratin 19 ◽  
Altered Gene ◽  
Ivd Degeneration

Intervertebral disc (IVD) degeneration is characterized by decreased cellularity and proteoglycan synthesis and increased inflammation, catabolism, and neural/vascular ingrowth. Regenerative methods for IVD degeneration are largely cell-therapy-based or involve viral vectors, which are associated with mutagenesis and undesired immune responses. The present study used bulk electroporation and engineered extracellular vesicles (EVs) to deliver forkhead-box F1 (FOXF1) mRNA to degenerate human nucleus pulposus (NP) cells as a minimally invasive therapeutic strategy for IVD regeneration. Bulk electroporation was used to investigate FOXF1 effects on human NP cells during a 4-week culture in 3D agarose constructs. Engineered EV delivery of FOXF1 into human IVD cells in monolayer was determined, with subsequent in vivo validation in a pilot mouse IVD puncture model. FOXF1 transfection significantly altered gene expression by upregulating healthy NP markers [FOXF1, keratin 19 (KRT19)], decreasing inflammatory cytokines [interleukin (IL)-1β, -6], catabolic enzymes [metalloproteinase 13 (MMP13)] and nerve growth factor (NGF), with significant increases in glycosaminoglycan accumulation in human NP cells. Engineered EVs loaded with FOXF1 demonstrated successful encapsulation of FOXF1 cargo and effective uptake by human NP cells cultured in monolayer. Injection of FOXF1-loaded EVs into the mouse IVD in vivo resulted in a significant upregulation of FOXF1 and Brachyury, compared to controls at 7 d post-injection, with no evidence of cytotoxicity. This is the first study to demonstrate non-viral delivery of FOXF1 and reprogramming of human NP cells in vitro and mouse IVD cells in vivo. This strategy represents a non-addictive approach for treating IVD degeneration and associated back pain.

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.

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.

Decreased Zn2+ Influx Underlies the Protective Role of Hypoxia in Rat Nucleus Pulposus Cells

2015 ◽  
Vol 168 (1) ◽  
pp. 196-205 ◽  
Author(s):  
Yin Xiao-Fan ◽  
Jiang Li-Bo ◽  
Ma Yi-Qun ◽  
Xu Jun ◽  
Gu Hui-Jie ◽  
...  
Keyword(s):  
Nucleus Pulposus ◽  
Protective Role ◽  
Nucleus Pulposus Cells
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