scholarly journals Retinoic acid inhibits the pyroptosis of degenerated nucleus pulposus cells by activating Sirt1-SOD2 signaling

2021 ◽  
Author(s):  
Peng-Fei Li ◽  
Fei Xiong ◽  
Ying Yin ◽  
Hong-Yuan Xing ◽  
Shao-Jun Hu ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Intervertebral Disc ◽  
Nucleus Pulposus ◽  
Underlying Mechanism ◽  
Ros Generation ◽  
Common Disease ◽  
Nucleus Pulposus Cells ◽  
Ivd Degeneration ◽  
Related Proteins

Abstract Background: Intervertebral disc (IVD) degeneration is a common disease and initiated by the degeneration of nucleus pulposus (NP). The pyroptosis of degenerated NP cells (dNPCs) plays an important role in NP degeneration and may be a potential target in the treatment of IVD degeneration. The purpose of this study is to identify a feasible solution that can inhibit NP cell pyroptosis to therapy the degeneration of the intervertebral disc. Result: In this study, we determined the effects of retinoic acid (RA) on dNPCs and investigated the underlying mechanism of RA mediated pyroptosis in dNPCs. We also verified the effects of RA on IVD degeneration in vivo. Our results demonstrated that RA significantly increased the proliferation and the protein expression of sox9, aggrecan, and collagen II of dNPCs. Pyroptosis-related proteins such as cleaved caspase-1, NT-GSDMD, IL-1β, IL-18, and the pyroptosis rate of dNPCs was significantly decreased by RA. We also found that Sirt1-SOD2 signaling was activated, while ROS generation and TXNIP/NLRP3 signaling in dNPCs was inhibited after the addition of RA. Furthermore, RA also recovered the structure of NP and increased the contents of sGAG and collagen in vivo. Conclusion Our study demonstrated that RA can inhibit the pyroptosis and increase the ECM synthesis function of dNPCs and verified that RA has a protective effect in IVD degeneration.

scholarly journals Injectable Hydrogel Combined with Nucleus Pulposus-Derived Mesenchymal Stem Cells for the Treatment of Degenerative Intervertebral Disc in Rats

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Feng Wang ◽  
Li-ping Nan ◽  
Shi-feng Zhou ◽  
Yang Liu ◽  
Ze-yu Wang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Intervertebral Disc ◽  
Nucleus Pulposus ◽  
Rat Model ◽  
Injectable Hydrogel ◽  
Cell Scaffold ◽  
Ivd Degeneration

Stem cell-based tissue engineering in treating intervertebral disc (IVD) degeneration is promising. An appropriate cell scaffold can maintain the viability and function of transplanted cells. Injectable hydrogel has the potential to be an appropriate cell scaffold as it can mimic the condition of the natural extracellular matrix (ECM) of nucleus pulposus (NP) and provide binding sites for cells. This study was aimed at investigating the effect of injectable hydrogel-loaded NP-derived mesenchymal stem cells (NPMSC) for the treatment of IVD degeneration (IDD) in rats. In this study, we selected injectable 3D-RGD peptide-modified polysaccharide hydrogel as a cell transplantation scaffold. In vitro, the biocompatibility, microstructure, and induced differentiation effect on NPMSC of the hydrogel were studied. In vivo, the regenerative effect of hydrogel-loaded NPMSC on degenerated NP in a rat model was evaluated. The results showed that NPMSC was biocompatible and able to induce differentiation in hydrogel in vivo. The disc height index (almost 87%) and MRI index (3313.83±227.79) of the hydrogel-loaded NPMSC group were significantly higher than those of other groups at 8 weeks after injection. Histological staining and immunofluorescence showed that the hydrogel-loaded NPMSC also partly restored the structure and ECM content of degenerated NP after 8 weeks. Moreover, the hydrogel could support long-term NPMSC survival and decrease cell apoptosis rate of the rat IVD. In conclusion, injectable hydrogel-loaded NPMSC transplantation can delay the level of IDD and promote the regeneration of the degenerative IVD in the rat model.

scholarly journals LRP5-deficiency in OsxCreERT2 mice models intervertebral disc degeneration by aging and compression

2019 ◽  
Author(s):  
Matthew J. Silva ◽  
Nilsson Holguin
Keyword(s):  
Transcription Factor ◽  
Intervertebral Disc ◽  
Wnt Signaling ◽  
Cell Fate ◽  
Biomechanical Properties ◽  
Nucleus Pulposus Cells ◽  
Hypertrophic Chondrocyte ◽  
Age Related ◽  
Ivd Degeneration

ABSTRACTOsterix is a critical transcription factor of mesenchymal stem cell fate, where its loss or loss of WNT signaling diverts differentiation to a chondrocytic lineage. Intervertebral disc (IVD) degeneration activates differentiation of prehypertrophic chondrocyte-like cells and inactivates WNT signaling, but its interacting role with osterix is unclear. First, compared to young-adult (5mo), mechanical compression of old (18mo) IVD induced greater IVD degeneration. Aging (5 vs 12mo) and/or compression reduced the transcription of osterix and notochordal marker T by 40-75%. Compression elevated transcription of hypertrophic chondrocyte marker MMP13 and pre-osterix transcription factor RUNX2, but less so in 12mo IVD. Next, using an Ai9/td reporter and immunohistochemistry, annulus fibrosus and nucleus pulposus cells of 5mo IVD expressed osterix, but aging and compression reduced its expression. Lastly, in vivo LRP5-deficiency in osterix-expressing cells degenerated the IVD, inactivated WNT signaling, reduced the biomechanical properties by 45-70%, and reduced transcription of osterix, notochordal markers and chondrocytic markers by 60-80%. Overall, these data indicate that age-related inactivation of WNT signaling in osterix-expressing cells may limit regeneration by depleting progenitors and attenuating the expansion of chondrocyte-like cells.

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 The REDD1/TXNIP Complex Accelerates Oxidative Stress-Induced Apoptosis of Nucleus Pulposus Cells through the Mitochondrial Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-22
Author(s):  
Huipeng Yin ◽  
Kun Wang ◽  
Abhirup Das ◽  
Gaocai Li ◽  
Yu Song ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Intervertebral Disc ◽  
Nucleus Pulposus ◽  
Cell Apoptosis ◽  
Redox Homeostasis ◽  
Mitochondrial Pathway ◽  
Nucleus Pulposus Cells ◽  
Damage Response ◽  
Induced Apoptosis ◽  
Ivd Degeneration

The death of nucleus pulposus (NP) cells is an important cause of intervertebral disc (IVD) degeneration. Redox disturbance caused by dysfunctional mitochondria has been considered as a vital risk for NP cell survival. It is valuable to identify key proteins maintaining mitochondrial function in NP cells. A previous study found that regulated in development and DNA damage response 1 (REDD1) are upregulated during intervertebral disc degeneration and that REDD1 can cause NP cell apoptosis. Thus, the present study further explores the effect of REDD1 on IVD degeneration. Our results showed that REDD1 promotes NP cell apoptosis via the mitochondrial pathway. Importantly, REDD1 formed a complex with TXNIP to strengthen its own action, and the combination was consolidated under H2O2-induced oxidative stress. The combined inhibition of the REDD1/TXNIP complex was better than that of REDD1 or TXNIP alone in restoring cell proliferation and accelerating apoptosis. Moreover, p53 acts as the transcription factor of REDD1 to regulate the REDD1/TXNIP complex under oxidative stress. Altogether, our results demonstrated that the REDD1/TXNIP complex mediated H2O2-induced human NP cell apoptosis and IVD degeneration through the mitochondrial pathway. Interferences on these sites to achieve mitochondrial redox homeostasis may be a novel therapeutic strategy for oxidative stress-associated IVD degeneration.

Effect of Inflammation on the Osmotic Response of Nucleus Pulposus Cells

2012 ◽  
Author(s):  
Robert Maidhof ◽  
Neena Rajan ◽  
Nadeen O. Chahine
Keyword(s):  
Nucleus Pulposus ◽  
Biomechanical Properties ◽  
Nucleus Pulposus Cells ◽  
Cellular Mechanisms ◽  
Osmotic Response ◽  
Tnf Α ◽  
Disc Cells ◽  
Cytokine Stimulation ◽  
Ivd Degeneration

Intervertebral disc (IVD) degeneration is accompanied by elevated levels of pro-inflammatory cytokines, particularly IL-1β and TNF-α [1]. Disc cells from the nucleus pulposus (NPs) respond to cytokine stimulation with increased catabolic breakdown of the tissue, resulting in a positive feedback of disc integrity loss and further inflammation [2]. Previous studies by our group have examined the response of NP cells to Toll-Like Receptor-4 (TLR-4) activation through stimulation with lipopolysaccharide (LPS). TLR-4 is a pattern recognition receptor that is activated in innate immunity and by polysaccharide fragments from degenerated proteoglycans. TLR-4 activation by LPS results in stimulation of multiple cytokines by NP cells [3]. Moreover, we have shown that in vivo LPS injection results in catabolic changes in the IVD, including matrix breakdown, decrease in biomechanical properties and loss of disc height [4]. However, the specific cellular mechanisms for these catabolic changes remain to be elucidated.

scholarly journals TonEBP regulates the hyperosmotic expression of aquaporin 1 and 5 in the intervertebral disc

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. W. Snuggs ◽  
S. Tessier ◽  
R. A. B. Bunning ◽  
I. M. Shapiro ◽  
M. V. Risbud ◽  
...  
Keyword(s):  
Gene Expression ◽  
Intervertebral Disc ◽  
Nucleus Pulposus ◽  
Central Region ◽  
Aquaporin 1 ◽  
Enhancer Binding Protein ◽  
Ivd Degeneration ◽  
Hyperosmotic Environment

AbstractThe central region of the intervertebral disc (IVD) is rich in proteoglycans, leading to a hyperosmotic environment, which fluctuates with daily loading. The cells of the nucleus pulposus (NP cells) have adapted to this environment via the function of tonicity enhancer binding protein (TonEBP), and NP cells have been shown to express several water channels known as aquaporins (AQP). We have previously shown that AQP1 and 5 decrease during IVD degeneration. Here, the regulation of AQP1 and 5 by hyperosmotic conditions and the role of TonEBP in this regulation was investigated. AQP1 and 5 gene expression was upregulated by hyperosmotic conditions mimicking the osmolality of the healthy IVD, which was abrogated by TonEBP knockdown. Furthermore, AQP1 and 5 immunopositivity was significantly reduced in TonEBPΔ/Δ E17.5 mice when compared with wildtype controls, indicating in vivo expression of AQP1 and 5 is controlled at least in part by TonEBP. This hyperosmotic regulation of AQP1 and 5 could help to explain the decreased AQP1 and 5 expression during degeneration, when the osmolality of the NP decreases. Together this data suggests that TonEBP-regulated osmo-adaptation may be disrupted during IVD degeneration when the expression of both AQPs is reduced.

scholarly journals Moracin attenuates LPS-induced inflammation in nucleus pulposus cells via Nrf2/HO-1 and NF-κB/TGF-β pathway

2019 ◽  
Vol 39 (12) ◽  
Author(s):  
Ronghe Gu ◽  
Zonggui Huang ◽  
Huijiang Liu ◽  
Qiwen Qing ◽  
Zou Zhuan ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Primary Culture ◽  
Nucleus Pulposus ◽  
Underlying Mechanism ◽  
Pcr Analysis ◽  
Protective Effects ◽  
Nucleus Pulposus Cells ◽  
Protein Levels ◽  
Lps Challenge ◽  
Smad 3

Abstract The present study was designed to investigate the protective effect of moracin on primary culture of nucleus pulposus cells in intervertebral disc and explore the underlying mechanism. Moracin treatment significantly inhibited the LPS-induced inflammatory cytokine accumulation (IL-1β, IL-6 and TNF-α) in nucleus pulposus cells. And moracin also dramatically decreased MDA activity, and increased the levels of SOD and CAT induced by LPS challenge. Moreover, the expressions of Nrf-2 and HO-1 were decreased and the protein levels of p-NF-κBp65, p-IκBα, p-smad-3 and TGF-β were increased by LPS challenge, which were significantly reversed after moracin treatments. Moracin treatments also decreased the levels of matrix degradation enzymes (MMP-3, MMP-13) as indicated by RT-PCR analysis. However, Nrf-2 knockdown abolished these protective effects of moracin. Together, our results demonstrated the ability of moracin to antagonize LPS-mediated inflammation in primary culture of nucleus pulposus in intervertebral disc by partly regulating the Nrf2/HO-1 and NF-κB/TGF-β pathway in nucleus pulposus cells.

scholarly journals Mitochondrial NDUFA4L2 attenuates the apoptosis of nucleus pulposus cells induced by oxidative stress via the inhibition of mitophagy

2019 ◽  
Vol 51 (11) ◽  
pp. 1-16 ◽  
Author(s):  
Wen-Ning Xu ◽  
Huo-Liang Zheng ◽  
Run-Ze Yang ◽  
Tao Liu ◽  
Wei Yu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Intervertebral Disc ◽  
Nucleus Pulposus ◽  
Intervertebral Disc Degeneration ◽  
Nucleus Pulposus Cells ◽  
Pathological Mechanism ◽  
First Time ◽  
The Relationship

AbstractThe main pathological mechanism of intervertebral disc degeneration (IVDD) is the programmed apoptosis of nucleus pulposus (NP) cells. Oxidative stress is a significant cause of IVDD. Whether mitophagy is induced by strong oxidative stress in IVDD remains to be determined. This study aimed to investigate the relationship between oxidative stress and mitophagy and to better understand the mechanism of IVDD in vivo and in vitro. To this end, we obtained primary NP cells from the human NP and subsequently exposed them to TBHP. We observed that oxidative stress induced mitophagy to cause apoptosis in NP cells, and we suppressed mitophagy and found that NP cells were protected against apoptosis. Interestingly, TBHP resulted in mitophagy through the inhibition of the HIF-1α/NDUFA4L2 pathway. Therefore, the upregulation of mitochondrial NDUFA4L2 restricted mitophagy induced by oxidative stress. Furthermore, the expression levels of HIF-1α and NDUFA4L2 were decreased in human IVDD. In conclusion, these results demonstrated that the upregulation of NDUFA4L2 ameliorated the apoptosis of NP cells by repressing excessive mitophagy, which ultimately alleviated IVDD. These findings show for the first time that NDUFA4L2 and mitophagy may be potential therapeutic targets for IVDD.

Sign in / Sign up

Export Citation Format

Share Document