Nucleus Pulposus Cells from Calcified Discs Promote the Degradation of the Extracellular Matrix through Upregulation of the GATA3 Expression

Objective Disc calcification is strongly associated with disc degeneration;however,the underlying mechanisms driving its pathogenesis are poorly understood.This study aimed to provide a gene expression profile of nucleus pulposus cells(NPCs)from calcified discs,and clarify the potential mechanism in disc degeneration.Methods Primary NPCs were isolated from calcified and control discs(CAL-NPC and CON-NPC),respectively.The proliferation and extracellular matrix(ECM)metabolism capacities of the cells were evaluated using MTT and Western blotting,respectively.RNA sequencing was used to identify differentially expressed genes(DEGs)in the CAL-NPCs.The biological functions of the DEGs were analyzed using the Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)databases.The transcription factor database and Cytoscape software were used to construct the transcription factor-DEGs regulatory network.The role of the verified transcription factor in NPC proliferation and ECM metabolism was also investigated.Results The CAL-NPCs exhibited a lower proliferation rate and higher ECM degradation capacity than the CON-NPCs.In total,375 DEGs were identified in the CAL-NPCs.The GO and KEGG analyses showed that the DEGs were primarily involved in the regulation of ribonuclease activity and NF-kappa B and p53 signaling pathways.GATA-binding protein 3(GATA3)with the highest verified levels was selected for further studies.Overexpression of GATA3 in the CON-NPCs significantly inhibited their proliferation and promoted their ECM degradation function,while the knockdown of GATA3 in the CAL-NPCs resulted in the opposite phenotypes.Conclusion This study provided a comprehensive gene expression profile of the NPCs from the calcified discs and supported that GATA3 could be a potential target for reversing calcification-associated disc degeneration.

How to enhance the ability of mesenchymal stem cells to alleviate intervertebral disc degeneration

Intervertebral disc(ID)degeneration(IDD)is one of the main causes of chronic low back pain,and degenerative lesions are usually caused by an imbalance between catabolic and anabolic processes in the ID.The environment in which the ID is located is harsh,with almost no vascular distribution within the disc,and the nutrient supply relies mainly on the diffusion of oxygen and nutrients from the blood vessels located under the endplate.The stability of its internal environment also plays an important role in preventing IDD.The main feature of disc degeneration is a decrease in the number of cells.Mesenchymal stem cells have been used in the treatment of disc lesions due to their ability to differentiate into nucleus pulposus cells in a nonspecific anti-inflammatory manner.The main purpose is to promote their regeneration.The current aim of stem cell therapy is to replace the aged and metamorphosed cells in the ID and to increase the content of the extracellular matrix.The treatment of disc degeneration with stem cells has achieved good efficacy,and the current challenge is how to improve this efficacy.Here,we reviewed current treatments for disc degeneration and summarize studies on stem cell vesicles,enhancement of therapeutic effects when stem cells are mixed with related substances,and improvements in the efficacy of stem cell therapy by adjuvants under adverse conditions.We reviewed the new approaches and ideas for stem cell treatment of disc degeneration in order to contribute to the development of new therapeutic approaches to meet current challenges.

The study of migration of bone mesenchymal stem cells transplanted in intervertebral discs of rabbits and expression of exogenous gene

Objective： To explore the survival and migration of bone mesenchymal stem cells transplantated in intervertebral disc of rabbits and expression of the exogenic genes. Methods. Thirty-two rabbits were used, A randomized block design was used and discs in the same rabbit were one block,the lumbar discs from L2-3 to L5-6 were randomly divided into blank group, saline group, cell transplantation group Ⅰand cell transplantation group Ⅱ. The fluorescence microscopy was used to determine the fluorescence of the maker protein GFP and DNA-PCR was used to analyze the copies of DNA of neomycin-resistant gene at 1, 3, 6, months after transplantation. Results： There was fluorescence in cell transplantation group Ⅰ and Ⅱ and none in blank group, saline group at 1, 3, 6 months after transplantation. In cell transplantation groups,the fluorescent distribution was more scatter with time, but no significant difference between cell groups Ⅰ and Ⅱ. The test of neomycin resistant gene expressed in cell transplantation group Ⅰ and Ⅱ and quantitative analysis showed that there was no significant difference between the cell groups Ⅰ and Ⅱ （P〉0.05）. Conclusion： The transplanted bone mesenchymal stem cells can survive, migrate and the transfer genes can express efficiently, it suggests that the BMSC therapy may be effective to prevent and treat intervertebral disc degeneration.

Regulating the fate of stem cells for regenerating the intervertebral disc degeneration

Lower back pain is a leading cause of disability and is one of the reasons for the substantial socioeconomic burden.The etiology of intervertebral disc(IVD)degeneration is complicated,and its mechanism is still not completely understood.Factors such as aging,systemic inflammation,biochemical mediators,toxic environmental factors,physical injuries,and genetic factors are involved in the progression of its pathophysiology.Currently,no therapy for restoring degenerated IVD is available except pain management,reduced physical activities,and surgical intervention.Therefore,it is imperative to establish regenerative medicine-based approaches to heal and repair the injured disc,repopulate the cell types to retain water content,synthesize extracellular matrix,and strengthen the disc to restore normal spine flexion.Cellular therapy has gained attention for IVD management as an alternative therapeutic option.In this review,we present an overview of the anatomical and molecular structure and the surrounding pathophysiology of the IVD.Modern therapeutic approaches,including proteins and growth factors,cellular and gene therapy,and cell fate regulators are reviewed.Similarly,small molecules that modulate the fate of stem cells for their differentiation into chondrocytes and notochordal cell types are highlighted.

Quercetin ameliorates oxidative stress-induced senescence in rat nucleus pulposus-derived mesenchymal stem cells via the miR-34a-5p/SIRT1 axis

BACKGROUND Intervertebral disc degeneration(IDD)is a main contributor to low back pain.Oxidative stress,which is highly associated with the progression of IDD,increases senescence of nucleus pulposus-derived mesenchymal stem cells(NPMSCs)and weakens the differentiation ability of NPMSCs in degenerated intervertebral discs(IVDs).Quercetin(Que)has been demonstrated to reduce oxidative stress in diverse degenerative diseases.AIM To investigate the role of Que in oxidative stress-induced NPMSC damage and to elucidate the underlying mechanism.METHODS In vitro,NPMSCs were isolated from rat tails.Senescence-associatedβ-galactosidase(SA-β-Gal)staining,cell cycle,reactive oxygen species(ROS),realtime quantitative polymerase chain reaction(RT-qPCR),immunofluorescence,and western blot analyses were used to evaluated the protective effects of Que.Meanwhile the relationship between miR-34a-5p and Sirtuins 1(SIRT1)was evaluated by dual-luciferase reporter assay.To explore whether Que modulates tert-butyl hydroperoxide(TBHP)-induced senescence of NPMSCs via the miR-34a-5p/SIRT1 pathway,we used adenovirus vectors to overexpress and downregulate the expression of miR-34a-5p and used SIRT1 siRNA to knockdown SIRT1 expression.In vivo,a puncture-induced rat IDD model was constructed,and X rays and histological analysis were used to assess whether Que could alleviate IDD in vivo.RESULTS We found that TBHP can cause NPMSCs senescence changes,such as reduced cell proliferation ability,increased SA-β-Gal activity,cell cycle arrest,the accumulation of ROS,and increased expression of senescence-related proteins.While abovementioned senescence indicators were significantly alleviated by Que treatment.Que decreased the expression levels of senescence-related proteins(p16,p21,and p53)and senescence-associated secreted phenotype(SASP),including IL-1β,IL-6,and MMP-13,and it increased the expression of SIRT1.In addition,the protective effects of Que on cell senescence were partially reversed by miR-34a-5p overexpression and SIRT1 knockdown.In vivo,X-ray,and histological analyses indicated that Que alleviated IDD in a punctureinduced rat model.CONCLUSION In summary,the present study provides evidence that Que reduces oxidative stress-induced senescence of NPMSCs via the miR-34a/SIRT1 signaling pathway,suggesting that Que may be a potential agent for the treatment of IDD.

Exosomes derived from stem cells as an emerging therapeutic strategy for intervertebral disc degeneration

Intervertebral disc(IVD)degenerative diseases are a common problem in the world,and they cause substantial social and economic burdens for people.The current methods for treating IVD degenerative diseases mainly include surgery and conservative treatment,which cannot fundamentally restore the normal structure of the disc.With continuous research on the mechanism of degeneration and the development of regenerative medicine,rapid progress has been made in the field of regenerative medicine regarding the use of stem cell-derived exosomes,which are active biological substances used in intercellular communication,because they show a strong effect in promoting tissue regeneration.The study of exosomes in the field of IVD degeneration has just begun,and many surprising achievements have been made.This paper mainly reviews the biological characteristics of exosomes and highlights the current status of exosomes in the field of IVD degeneration,as well as future developments regarding exosomes.

Transcription regulators differentiate mesenchymal stem cells into chondroprogenitors,and their in vivo implantation regenerated the intervertebral disc degeneration

BACKGROUND Intervertebral disc degeneration(IVDD)is the leading cause of lower back pain.Disc degeneration is characterized by reduced cellularity and decreased production of extracellular matrix(ECM).Mesenchymal stem cells(MSCs)have been envisioned as a promising treatment for degenerative illnesses.Cell-based therapy using ECM-producing chondrogenic derivatives of MSCs has the potential to restore the functionality of the intervertebral disc(IVD).AIM To investigate the potential of chondrogenic transcription factors to promote differentiation of human umbilical cord MSCs into chondrocytes,and to assess their therapeutic potential in IVD regeneration.METHODS MSCs were isolated and characterized morphologically and immunologically by the expression of specific markers.MSCs were then transfected with Sox-9 and Six-1 transcription factors to direct differentiation and were assessed for chondrogenic lineage based on the expression of specific markers.These differentiated MSCs were implanted in the rat model of IVDD.The regenerative potential of transplanted cells was investigated using histochemical and molecular analyses of IVDs.RESULTS Isolated cells showed fibroblast-like morphology and expressed CD105,CD90,CD73,CD29,and Vimentin but not CD45 antigens.Overexpression of Sox-9 and Six-1 greatly enhanced the gene expression of transforming growth factor beta-1 gene,BMP,Sox-9,Six-1,and Aggrecan,and protein expression of Sox-9 and Six-1.The implanted cells integrated,survived,and homed in the degenerated intervertebral disc.Histological grading showed that the transfected MSCs regenerated the IVD and restored normal architecture.CONCLUSION Genetically modified MSCs accelerate cartilage regeneration,providing a unique opportunity and impetus for stem cell-based therapeutic approach for degenerative disc diseases.

Early efficacy of endoscopic translaminar and intervertebral foraminal approaches in the treatment of lumbar disc herniation

Objective:To investigate the early efficacy of two approaches for lumbar disc herniation under spinal endoscopy.Methods:45 cases of lumbar disc herniation were divided into interlaminar approach(27 cases)and intervertebral foramen approach(18 cases)according to different surgical approaches.Postoperative pain visual analogue scale(VAS)was used.Japanese Orthopaedic Association(JOA)lumbar spine score(JOA)and modified Macnab criteria were used to evaluate the postoperative outcome.Results:(1)VAS score.There is no interaction effect between the access mode and the time factor(F=0.620,P=0.603).There were statistically significant differences in pain VAS scores between preoperative and postoperative time points,that is,there was a time effect(F=2157.488,P=0.000).The overall VAS scores of the two groups were compared,and the difference was not statistically significant,that is,there was no grouping effect(F=2.610,P=0.114).The VAS score of pain in both groups decreased with time,and the differences between the two groups were not statistically significant before surgery,at discharge,1 month after surgery and 3 months after surgery(t=0.067,P=0.947;t=1.415,P=0.164;t=0.564,P=0.575;t=0.442,P=0.660);JOA score.There is no interaction effect between the access mode and the time factor(F=1.296,P=0.280).The difference of JOA score between preoperative and postoperative time points was statistically significant,that is,there was a time effect(F=1464.830,P=0.000).JOA scores of the two groups showed an increasing trend with time,and the differences between the two groups were not statistically significant before surgery,at discharge,1 month after surgery and 3 months after surgery(t=0.067,P=0.947;t=1.415,P=0.164;t=0.564,P=0.575;t=0.442,P=0.660);(2)The improved Macnab standard was used to evaluate the excellent and good rate at 3 months after surgery.In the interlaminar group,12 cases were excellent,13 cases were good and 2 cases were fair.The excellent and good rate was 92.6%.In the intervertebral foramen group,7 cases were excellent,10 cases were good and 1 case was fair.The excellent and good rate was 94.4%.The overall excellent and good rate of the two groups was 93.3%.Conclusion:Both approaches can achieve satisfactory efficacy in the treatment of lumbar intervertebral disc herniation,which is worthy of clinical application.However,for beginners,l5-s1 lumbar disc herniation is more suitable for intervertebral disc approach,so as to achieve satisfactory efficacy.

The Artificial Disc Nucleus and Other Strategies for Replacement of the Nucleus Pulposus:Past,Present and Future Designs for an Emerging Surgical Solution

Nucleus Pulposus(NP)Replacement is a developing surgical methodology for the treatment of pathology related to degeneration of intervertebral discs(IVDs).This article provides necessary context regarding the patholo-gies treated with this technology,the biomechanical structure and function of the IVD,and the procedures this technology aims to replace.Primarily,it provides an overview and discussion of commercial and experimental preformed and in situ curing prosthesis designs reported in the scientific literature and summarizes the results of biomechanical and clinical studies evaluating their efficacy.Contextual and updated information on the most recent research into NP replacement with novel hydrogel and tissue engineering(TE)strategies is described.Replacement of the NP allows for potential improvement in the treatment of degenerative spinal pathologies through minimally invasive surgical techniques.

An esterase-responsive ibuprofen nano-micelle pre-modified embryo derived nucleus pulposus progenitor cells promote the regeneration of intervertebral disc degeneration

Stem cell-based transplantation is a promising therapeutic approach for intervertebral disc degeneration(IDD).Current limitations of stem cells include with their insufficient cell source,poor proliferation capacity,low nucleus pulposus(NP)-specific differentiation potential,and inability to avoid pyroptosis caused by the acidic IDD microenvironment after transplantation.To address these challenges,embryo-derived long-term expandable nucleus pulposus progenitor cells(NPPCs)and esterase-responsive ibuprofen nano-micelles(PEG-PIB)were prepared for synergistic transplantation.In this study,we propose a biomaterial pre-modification cell strategy;the PEG-PIB were endocytosed to pre-modify the NPPCs with adaptability in harsh IDD microenvironment through inhibiting pyroptosis.The results indicated that the PEG-PIB pre-modified NPPCs exhibited inhibition of pyroptosis in vitro;their further synergistic transplantation yielded effective functional recovery,histological regeneration,and inhibition of pyroptosis during IDD regeneration.Herein,we offer a novel biomaterial pre-modification cell strategy for synergistic transplantation with promising therapeutic effects in IDD regeneration.

Stem cells sources for intervertebral disc regeneration

Intervertebral disc regeneration field is rapidly growing since disc disorders represent a major health problem in industrialized countries with very few possible treatments.Indeed, current available therapies are symptomatic, and surgical procedures consist in disc removal and spinal fusion, which is not immune to regardable concerns about possible comorbidities, cost-effectiveness, secondary risks and long-lasting outcomes. This review paper aims to share recent advances in stem cell therapy for the treatment of intervertebral disc degeneration. In literature the potential use of different adult stem cells for intervertebral disc regeneration has already been reported. Bone marrow mesenchymal stromal/stem cells, adipose tissue derived stem cells, synovial stem cells, muscle-derived stem cells, olfactory neural stem cells, induced pluripotent stem cells, hematopoietic stem cells, disc stem cells, and embryonic stem cells have been studied for this purpose either in vitro or in vivo. Moreover, several engineered carriers(e.g., hydrogels), characterized by full biocompatibility and prompt biodegradation, have been designed and combined with different stem cell types in order to optimize the local and controlled delivery of cellular substrates in situ. The paper overviews the literature discussing the current status of our knowledge of the different stem cells types used as a cell-based therapy for disc regeneration.

Insights of stem cell-based endogenous repair of intervertebral disc degeneration

Low back pain has become more prevalent in recent years,causing enormous economic burden for society and government.Common therapies used in clinics including conservative treatment and surgery can only relieve pain.Subsequent cell-based treatment such as mesenchymal stem cell transplantation poses problems such as short duration of therapeutic effect and tumorigenesis.Recently,the discovery and identification of stem cell niche and stem/progenitor cells in intervertebral disc bring increased attention to endogenous repair strategy.Therefore,we review the studies involving endogenous repair strategy and present the characteristics and current status of this treatment.Meanwhile,we also discuss the strategy and perspective of endogenous repair strategy in future.

Stromal cell-derived factor-1α promotes recruitment and differentiation of nucleus pulposus-derived stem cells

BACKGROUND Intervertebral disc(IVD) degeneration is a condition characterized by a reduction in the water and extracellular matrix content of the nucleus pulposus(NP) and is considered as one of the dominating contributing factors to low back pain. Recent evidence suggests that stromal cell-derived factor 1α(SDF-1α) and its receptor CX-C chemokine receptor type 4(CXCR4) direct the migration of stem cells associated with injury repair in different musculoskeletal tissues.AIM To investigate the effects of SDF-1α on recruitment and chondrogenic differentiation of nucleus pulposus-derived stem cells(NPSCs).METHODS We performed real-time RT-PCR and enzyme-linked immunosorbent assay to examine the expression of SDF-1α in nucleus pulposus cells after treatment with pro-inflammatory cytokines in vitro. An animal model of IVD degeneration was established using annular fibrosus puncture in rat coccygeal discs. Tissue samples were collected from normal control and degeneration groups.Differences in the expression of SDF-1α between the normal and degenerative IVDs were analyzed by immunohistochemistry. The migration capacity of NPSCs induced by SDF-1α was evaluated using wound healing and transwell migration assays. To determine the effect of SDF-1α on chondrogenic differentiation of NPSCs, we conducted cell micromass culture and examined the expression levels of Sox-9, aggrecan, and collagen II. Moreover, the roles of SDF-1/CXCR4 axis in the migration and chondrogenesis differentiation of NPSCs were analyzed by immunofluorescence, immunoblotting, and real-time RT-PCR.RESULTS SDF-1α was significantly upregulated in the native IVD cells cultured in vitro with pro-inflammatory cytokines, such as interleukin-1β and tumor necrosis factor-α, mimicking the degenerative settings. Immunohistochemical staining showed that the level of SDF-1α was also significantly higher in the degenerative group than in the normal group. SDF-1α enhanced the migration capacity of NPSCs in a dose-dependent manner. In addition, SDF-1α induced chondrogenic differentiation of NPSCs, as evidenced by the increased expression of chondrogenic markers using histological and immunoblotting analyses. Realtime RT-PCR, immunoblotting, and immunofluorescence showed that SDF-1αnot only increased CXCR4 expression but also stimulated translocation of CXCR4 from the cytoplasm to membrane, accompanied by cytoskeletal rearrangement.Furthermore, blocking CXCR4 with AMD3100 effectively suppressed the SDF-1α-induced migration and differentiation capacities of NPSCs.CONCLUSION These findings demonstrate that SDF-1α has the potential to enhance recruitment and chondrogenic differentiation of NPSCs via SDF-1/CXCR4 chemotaxis signals that contribute to IVD regeneration.

Technique of Percutaneous Transforaminal Endoscopic Discectomy for the Treatment of Lumbar Disc Herniation

Percutaneous Transforaminal Endoscopic Discectomy is a minimally invasive surgery with little pain, less blood loss, less hospital stay and the surgery can be done in local anesthesia, which was started during late 20th century. Kambin and Gellmann in 1973 in the United States and Hijikata in Japanin 1977 individually preformed posterolateral percutaneous nucleotomy for the resection of the nucleus pulposus and release of compressed exiting nerve root, which is now spreading through the world and many surgeons are developing their skill but it needs experience and patience for successful outcomes. Along with advanced instruments now the surgery can be performed only giving a small skin incision of 8 - 10 mm and is as effective as the conventional method of surgery and open microdiscectomy surgery for the treatment of symptomatic lumbar disc herniation. In this review, we are explaining the technique of minimally invasive Percutaneous Transforaminal Endoscopic Discectomy surgery along its advantages and complications which can be encountered while performing this technique.

Mesenchymal stem cell tracking in the intervertebral disc

Low back pain is a common clinical problem, which leads to significant social, economic and public health costs. Intervertebral disc(IVD) degeneration is accepted as a common cause of low back pain. Initially, this is characterized by a loss of proteoglycans from the nucleus pulposus resulting in loss of tissue hydration and hydrostatic pressure. Conservative management,including analgesia and physiotherapy often fails and surgical treatment, such as spinal fusion, is required. Stem cells offer an exciting possible regenerative approach to IVD disease. Preclinical research has demonstrated promising biochemical, histological and radiological results in restoring degenerate IVDs. Cell tracking provides an opportunity to develop an in-depth understanding of stem cell survival, differentiation and migration, enabling optimization of stem cell treatment. Magnetic Resonance Imaging(MRI) is a non-invasive, non-ionizing imaging modality with high spatial resolution, ideally suited for stem cell tracking. Furthermore, novel MRI sequences have the potential to quantitatively assess IVD disease, providing an improved method to review response to biological treatment. Superparamagnetic iron oxide nanoparticles have been extensively researched for the purpose of cell tracking. These particles are biocompatible, non-toxic and act as excellent MRI contrast agents. This review will explore recent advances and issues in stem cell tracking and molecular imaging in relation to the IVD.

Stem cells in intervertebral disc regeneration-more talk than action?

Pain and lifestyle changes are common consequences of intervertebral disc degeneration(IVDD)and affect a large part of the aging population.The stemness of cells is exploited in the field of regenerative medicine as key to treat degenerative diseases.Transplanted cells however often face delivery and survival challenges,especially in tissues with a naturally harsh microniche environment such as the intervertebral disc.Recent interest in the secretome of stem cells,especially cargo protected from microniche-related decay as frequently present in degenerating tissues,provides new means of rejuvenating ailing cells and tissues.Exosomes,a type of extracellular vesicles with purposeful cargo gained particular interest in conveying stem cell related attributes of rejuvenation,which will be discussed here in the context of IVDD.

6-gingerol protects nucleus pulposus-derived mesenchymal stem cells from oxidative injury by activating autophagy

BACKGROUND To date,there has been no effective treatment for intervertebral disc degeneration(IDD).Nucleus pulposus-derived mesenchymal stem cells(NPMSCs)showed encouraging results in IDD treatment,but the overexpression of reactive oxygen species(ROS)impaired the endogenous repair abilities of NPMSCs.6-gingerol(6-GIN)is an antioxidant and anti-inflammatory reagent that might protect NPMSCs from injury.AIM To investigate the effect of 6-GIN on NPMSCs under oxidative conditions and the potential mechanism.METHODS The cholecystokinin-8 assay was used to evaluate the cytotoxicity of hydrogen peroxide and the protective effects of 6-GIN.ROS levels were measured by 2´7´-dichlorofluorescin diacetate analysis.Matrix metalloproteinase(MMP)was detected by the tetraethylbenzimidazolylcarbocyanine iodide assay.TUNEL assay and Annexin V/PI double-staining were used to determine the apoptosis rate.Additionally,autophagy-related proteins(Beclin-1,LC-3,and p62),apoptosisassociated proteins(Bcl-2,Bax,and caspase-3),and PI3K/Akt signaling pathwayrelated proteins(PI3K and Akt)were evaluated by Western blot analysis.Autophagosomes were detected by transmission electron microscopy in NPMSCs.LC-3 was also detected by immunofluorescence.The mRNA expression of collagen II and aggrecan was evaluated by real-time polymerase chain reaction(RT-PCR),and the changes in collagen II and MMP-13 expression were verified through an immunofluorescence assay.RESULTS 6-GIN exhibited protective effects against hydrogen peroxide-induced injury in NPMSCs,decreased hydrogen peroxide-induced intracellular ROS levels,and inhibited cell apoptosis.6-GIN could increase Bcl-2 expression and decrease Bax and caspase-3 expression.The MMP,Annexin V-FITC/PI flow cytometry and TUNEL assay results further confirmed that 6-GIN treatment significantly inhibited NPMSC apoptosis induced by hydrogen peroxide.6-GIN treatment promoted extracellular matrix(ECM)expression by reducing the oxidative stress injury-induced increase in MMP-13 expression.6-GIN activated autophagy by increasing the expression of autophagy-related markers(Beclin-1 and LC-3)and decreasing the expression of p62.Autophagosomes were visualized by transmission electron microscopy.Pretreatment with 3-MA and BAF further confirmed that 6-GIN-mediated stimulation of autophagy did not reduce autophagosome turnover but increased autophagic flux.The PI3K/Akt pathway was also found to be activated by 6-GIN.6-GIN inhibited NPMSC apoptosis and ECM degeneration,in which autophagy and the PI3K/Akt pathway were involved.CONCLUSION 6-GIN efficiently decreases ROS levels,attenuates hydrogen peroxide-induced NPMSCs apoptosis,and protects the ECM from degeneration.6-GIN is a promising candidate for treating IDD.

Comparison of microendoscopic discectomy and open discectomy for single-segment lumbar disc herniation

BACKGROUND Lumbar disc herniation is a common disease.Endoscopic treatment may have more advantages than traditional surgery.AIM To compare the clinical efficacy and safety of microendoscopic discectomy(MED)and open discectomy with lamina nucleus enucleation in the treatment of singlesegment lumbar intervertebral disc herniation.METHODS Ninety-six patients who were operated at our hospital were selected for this study.Patients with single-segment lumbar disc herniation were admitted to the hospital from March 2018 to March 2019 and were randomly divided into the observation group and the control group with 48 cases in each group.The former group underwent lumbar discectomy and the latter underwent laparotomy and nucleus pulpectomy.Surgical effects were compared between the two groups.RESULTS In terms of surgical indicators,the observation group had a longer operation time,shorter postoperative bedtime and hospital stay,less intraoperative blood loss,and smaller incision length than the control group(P<0.05).The excellent recovery rate did not differ significantly between the observation group(93.75%)and the control group(91.67%).Visual analogue scale pain scores were significantly lower in the observation group than in the control group at 1 d,3 d,1 mo,and 6 mo after surgery(P<0.05).The incidence of complications was significantly lower in the observation group than in the control group(6.25%vs 22.92%,P<0.05).CONCLUSION Both MED and open discectomy can effectively improve single-segment lumbar disc herniation,but MED is associated with less trauma,less bleeding,and a lower incidence of complications.

Transplantation of gene-modified nucleus pulposus cells reverses rabbit intervertebral disc degeneration

Background Intervertebral disc degeneration is the main cause of low back pain. The purpose of this study was to explore potential methods for reversing the degeneration of lumbar intervertebral discs by transplantation of gene-modified nucleus pulposus cells into rabbit degenerative lumbar intervertebral discs after transfecting rabbit nucleus pulposus cells with adeno-associated virus 2 （AAV2）-mediated connective tissue growth factor （CTGF） and tissue inhibitor of metalloproteinases 1 （TIMP1） genes in vitro. Methods Computer tomography （CT）-guided percutaneous annulus fibrosus injury was performed to build degenerative lumbar intervertebral disc models in 60 New Zealand white rabbits, rAAV2-CTGF-IRES-TIMPI-transfected rabbit nucleus pulposus cells were transplanted into degenerative lumbar intervertebral discs （transplantation group）, phosphate-buffered saline （PBS） was injected into degenerative lumbar intervertebral discs （degeneration control group） and normal lumbar intervertebral discs served as a blank control group. After 6, 10 and 14 weeks, the disc height index （DHI） and signal intensity in intervertebral discs were observed by X-ray and magnetic resonance imaging （MRI） analysis The expression of CTGF and TIMP1 in nucleus pulposus tissue was determined by Western blotting analysis, the synthesis efficiency of proteoglycan was determined by a 35S-sulfate incorporation assay, and the mRNA expression of type II collagen and proteoglycan was detected by RT-PCR. Results MRI confirmed that degenerative intervertebral discs appeared two weeks after percutaneous puncture. Transgenic nucleus pulposus cell transplantation could retard the rapid deterioration of the DHI. MRI indicated that degenerative intervertebral discs were relieved in the transplantation group compared with the degeneration control group. The expression of collagen II mRNA and proteoglycan mRNA was significantly higher in the transplantation group and the blank control group compared with the degeneration control group （P 〈0.05）. Conclusions CT-guided percutaneous puncture can successfully build rabbit degenerative intervertebral disc models. Both CTGF and TIMPl-transfected cell transplantation helps to maintain disc height, and promotes the biosynthesis of tvDe II collaQen and proteoalvcan in intervertebral discs, reversinq the de（：ieneration of intervertebral discs.

Delivery of coenzyme Q10 loaded micelle targets mitochondrial ROS and enhances efficiency of mesenchymal stem cell therapy in intervertebral disc degeneration

Stem cell transplantation has been proved a promising therapeutic instrument in intervertebral disc degeneration(IVDD).However,the elevation of oxidative stress in the degenerated region impairs the efficiency of mesenchymal stem cells(BMSCs)transplantation treatment via exaggeration of mitochondrial ROS and promotion of BMSCs apoptosis.Herein,we applied an emulsion-confined assembly method to encapsulate Coenzyme Q10(Co-Q10),a promising hydrophobic antioxidant which targets mitochondria ROS,into the lecithin micelles,which renders the insoluble Co-Q10 dispersible in water as stable colloids.These micelles are injectable,which displayed efficient ability to facilitate Co-Q10 to get into BMSCs in vitro,and exhibited prolonged release of Co-Q10 in intervertebral disc tissue of animal models.Compared to mere use of Co-Q10,the Co-Q10 loaded micelle possessed better bioactivities,which elevated the viability,restored mitochondrial structure as well as function,and enhanced production of ECM components in rat BMSCs.Moreover,it is demonstrated that the injection of this micelle with BMSCs retained disc height and alleviated IVDD in a rat needle puncture model.Therefore,these Co-Q10 loaded micelles play a protective role in cell survival and differentiation through antagonizing mitochondrial ROS,and might be a potential therapeutic agent for IVDD.