OBJECTIVE: To explore mechanisms of acid-sensing ion channel 1 (ASIC1) mediated lumbar nucleus pulposus cell apoptosis through extracellular-signalregulated protein kinase 5 (ERK5) signaling pathway and mitochondrial dysfunction pathway. METHODS: Totally 34 patients with degenerative lumbar disc herniation (LDH) admitted from January 2020 to December 2022 were collected as research objects, including 21 males and 13 females;aged from 29 to 52 years old with an average of (37.43±4.75) years old;22 patients with grade Ⅱ and 12 patients with grade Ⅳ, according to Pfirrmann grading criteria;15 patients with L_4,5 and 19 patients with L₅S₁. The expression of ASIC1 in nucleus pulposus of LDH patients was measured by immunohistochemical staining. Nucleus pulposus cells were cultured by primary culture method, identified by toluidine blue staining and immunohistochemical staining, and the expression of ASIC1 protein was located by immunofluorescence staining. According to the addition of siRNA-ASIC1, ASIC1 overexpression plasmid, and ERK5 inhibitors, the nucleus pulpocyte was divided into three groups, named as SIRNA-silenced group, overexpression group, and inhibitor group, with 3 patients in each group. Cells of each group were collected at 72 h after intervention, expression of ASIC1, ERK5, BCL-xL/BCL-2-associated Death promoter (Bad), B-cell lymphoma-2 associated X (Bax) and B-cell lymphoblast-2 gene (Bcl-2) were detected by reverse transcription-polymerase chain reaction (RT-PCR);intracellular calcium ion levels were detected by calcium ion kit, mitochondrial membrane potential was detected by JC-1 kit, and apoptosis was observed by AV-PI kit. RESULTS: In LDH patients with grade Ⅳ, nucleus pulposus tissue removed during operation revealed poor elasticity, white color and poor ductility, and immunohistochemical results showed increased ASIC1 expression. There was no significant difference in mRNA relative expression of ASIC1 between siRNA silencing group (0.31±0.03) and inhibitor group (0.39±0.05) (P>0.05). The mRNA relative expression level of ERK5 in siRNA silencing group(0.32±0.05) was significantly higher than that in inhibitor group (0.15±0.04)(P<0.05), which suggested ERK5 was the downstream molecule of ASIC1. The mRNA relative expression levels of apoptosis promoting factor Bad and Bax in siRNA silencing group and inhibitor group were lower than those in overexpression group(P<0.05), the relative expression level of anti-apoptosis factor Bcl-2 mRNA was significantly increased (P<0.05). The calcium content in overexpression group was higher than that in siRNA silencing and inhibitor groups (P<0.05), the normal proportion of mitochondrial membrane potential in overexpression group was lower than that in siRNA silencing and inhibitor group (P<0.05), and the apoptosis rate in overexpression group was higher than that in siRNA silencing and inhibitor group (P<0.05). CONCLUSION After the activation of ASIC1 channel protein, calcium ions could enter the cells and act as a second messenger molecule to regulate apoptosis of nucleus pulposus cells by ERK5 signaling pathway and mitochondrial disorder pathway.
Humans ; Acid Sensing Ion Channels/physiology* ; Male ; Female ; Apoptosis ; Middle Aged ; Adult ; Signal Transduction ; Mitogen-Activated Protein Kinase 7/physiology* ; Mitochondrial Diseases/genetics* ; Nucleus Pulposus/metabolism* ; Intervertebral Disc Degeneration/metabolism* ; Mitochondria/metabolism* ; Intervertebral Disc Displacement/genetics*

Intervertebral disc degeneration (IDD) is the main cause of low back pain. Immune cells play an extremely important role in regulating the progression of IDD by interacting with nucleus pulposus (NP) cells and the extracellular matrix (ECM). Healthy NP tissue is a vascular-free and immune-privileged tissue that does not normally interact with macrophages. However, the establishment of neovascularization channels in damaged intervertebral discs has led to extensive cross-talk between NP and macrophages, with different results depending on microenvironmental stimuli. Based on this, this review reviewed the correlation between IDD and low back pain, summarized the source and function of macrophages, and discussed the possible regulatory mechanism between macrophages and discogenic pain. Finally, potential therapies targeting macrophages to delay IDD in recent years were also discussed, aiming to emphasize the important role of immunology in IDD and provide a new direction for the prevention and treatment of IDD.
Humans ; Intervertebral Disc Degeneration/complications* ; Macrophages/immunology* ; Low Back Pain/immunology* ; Nucleus Pulposus ; Animals ; Extracellular Matrix

Lumbar disc (LD) herniation and aging are prevalent conditions that can result in substantial morbidity. This study aimed to clarify the mechanisms connecting the LD aging and herniation, particularly focusing on cellular senescence and molecular alterations in the nucleus pulposus (NP). We performed a detailed analysis of NP samples from a diverse cohort, including individuals of varying ages and those with diagnosed LD herniation. Our methodology combined histological assessments with single-nucleus RNA sequencing to identify phenotypic and molecular changes related to NP aging and herniation. We discovered that cellular senescence and a decrease in nucleus pulposus progenitor cells (NPPCs) are central to both processes. Additionally, we found an age-related increase in NFAT1 expression that promotes NPPC senescence and contributes to both aging and herniation of LD. This research offers fresh insights into LD aging and its associated pathologies, potentially guiding the development of new therapeutic strategies to target the root causes of LD herniation and aging.
Intervertebral Disc Displacement/metabolism* ; Humans ; Aging/pathology* ; Nucleus Pulposus/pathology* ; Male ; Female ; Transcriptome ; Middle Aged ; Lumbar Vertebrae/pathology* ; Adult ; Cellular Senescence ; Stem Cells/pathology* ; Aged ; Intervertebral Disc Degeneration/metabolism*

OBJECTIVE: To explore feasibility, clinical and imaging outcomes of percutaneous endoscopic interlaminar discectomy (PEID) for single level large lumbar disc herniation(LDH). METHODS: From October 2018 to March 2023, 31 patients with single level LDH treated with PEID were retrospectively analyzed. Among patients, including 18 males and 13 females, aged from 15 to 40 years old with an average of (28.5±7.4) years old;L_4,5 in 10 patients, L₅S₁ in 21 patients;14 patients on the left side, 17 patients on the right side;the courses of disease ranged from 3 to 19 months with an average of (6.8 ± 3.1) months. Operation time, blood loss, fluoroscopy times and hospital stay were observed. Visual analogue scale (VAS) was used to evaluate low back and leg pain, Oswestry disability index (ODI) was used to evaluate lumbar function, modified MacNab was used to evaluate clinical efficacy at the latest follow-up. Median sagittal diameter of spinal canal, effective sagittal diameter of spinal canal, spinal canal area, and dural sac area were used to evaluate spinal decompression. Anterior, middle, and posterior heights of intervertebral space were used to evaluate intervertebral space changes. RESULTS: All patients were performed spinal endoscopic surgery, operation time ranged from 30 to 71 min with an average of (48.7±14.2) min, blood loss ranged from 10 to 40 ml with an average of (21.1±7.0) ml, and intraoperative fluoroscopy times ranged from 4 to 7 with an average of (4.7±0.7). The hospital stay ranged from 3 to 8 days with an average of (5.1±1.3) days, and postoperative follow-up ranged from 12 to 34 months with an average of (16.9±4.1) months. VAS of low back pain before operation and 3, 6 months after operation, the latest follow-up were (6.2±1.8), (1.4±0.8), (1.9±0.7), (1.6±0.6), respectively;VAS of leg pain were (7.6±1.6), (1.8±0.9), (1.6±0.6), (1.4±0.7), respectively;ODI were (35.74±4.62), (6.68±1.78), (6.90±1.85), (7.10±1.94), respectively;postoperative lower back pain and leg pain VAS and ODI were significantly improved at all time points after operation (P<0.05). Postoperative VAS of low back pain at 6 months was higher than that of 3 months after operation (P<0.05). At the laest follow-up, 14 patients were excellent, 15 good, and 2 acceptable according to modified MacNab standard. Median diameters of spinal canal were (0.77±0.18) and (1.18±0.24) cm before operation and at the latest follow-up. The effective diameters of spinal canal were (0.48±0.17) and (0.89±0.23) cm, respectively. The vertebral canal areas were (0.90±0.22) and (1.68±0.43) cm², respectively. Dural sac areas were (0.41±0.10) and (0.81±0.24) cm², respectively. At the least follow-up, median diameter, effective diameter, area of spinal canal and dural sac were significantly increased compared with those before operation (P<0.05). Anterior vertebral space height before operation was (1.13±0.13) cm, and improved to (0.83±0.11) cm at the latest follow-up. Central height decreased from (0.81±0.20) cm before operation to (0.61±0.14) cm at the latest follow-up. The height of posterior margin decreased from (0.67±0.21) cm before operation to (0.46±0.15) cm at the latest follow-up (P<0.05). CONCLUSION PEID for giant LDH could effectively remove protruding giant nucleus pulposus tissue, and avoid injury to cauda equina nerve and nerve roots, which has good early clinical effect. However, the height of intervertebral space was obviously lost after operation.
Humans ; Male ; Female ; Adult ; Intervertebral Disc Displacement/surgery* ; Lumbar Vertebrae/surgery* ; Endoscopy/methods* ; Young Adult ; Adolescent ; Diskectomy, Percutaneous/methods* ; Retrospective Studies ; Nucleus Pulposus/surgery*

This study aims to investigate the effects of Bushen Huoxue Decoction regulating adipose-derived stem cells(ADSCs)-exosomes(Exos) on the apoptosis of intervertebral disc nucleus pulposus cells(NPCs) and extracellular signal-regulated kinase(ERK) signaling pathway. Tert-butyl hydrogen peroxide(TBHP)-induced NPCs were divided into control, model, drug-containing serum, blank Exos, normal serum Exos, and drug-containing serum Exos groups. Cell viability and proliferation were examined by the CCK-8 assay and EdU staining, respectively. The cell cycle and apoptosis were evaluated by flow cytometry. Enzyme-linked immunosorbent assay was employed to measure the levels of interleukin(IL)-1β, tumor necrosis factor(TNF)-α, and IL-6. The mRNA levels of aggrecan, collagen type Ⅱ alpha 1 chain(COL2A1), and ERK were determined by qRT-PCR, and the protein levels of aggrecan, COL2A1, and p-ERK were determined by Western blot. The results showed that compared with the model group, the treatments with drug-containing serum, blank Exos, and normal serum Exos enhanced the viability and proliferation of NPCs, decreased the proportion of cells in the G_0/G_1 phase, increased the proportion of cells in the S phase, reduced apoptosis, lowered the levels of IL-1β, TNF-α, and IL-6, up-regulated the mRNA and protein levels of aggrecan and COL2A1, and down-regulated the mRNA level of ERK and the protein level of p-ERK. Compared with the drug-containing serum, blank Exos, and normal serum Exos groups, the treatment with drug-containing serum Exos enhanced the viability and proliferation of NPCs, decreased the proportion of cells in the G_0/G_1 phase, increased the cells in the S phase, reduced apoptosis, lowered the levels of IL-1β, TNF-α, and IL-6, up-regulated the mRNA and protein levels of aggrecan and COL2A1, and down-regulated the mRNA level of ERK and the protein level of p-ERK. The results confirmed that the Exos secreted by ADSCs after treatment with Bushen Huoxue Decoction-containing serum promoted the proliferation of degenerated NPCs, inhibited apoptosis and the expression of inflammatory mediators, and promoted the production of proteoglycans and collagen, thus delaying the progression of intervertebral disc degeneration, the mechanism of which was related to the regulation of the ERK signaling pathway.
Intervertebral Disc Degeneration/drug therapy* ; Apoptosis/drug effects* ; Nucleus Pulposus/cytology* ; Drugs, Chinese Herbal/pharmacology* ; Animals ; Rats ; MAP Kinase Signaling System/drug effects* ; Rats, Sprague-Dawley ; Collagen Type II/metabolism* ; Humans ; Cell Proliferation/drug effects* ; Stem Cells/metabolism* ; Aggrecans/metabolism* ; Cell Survival/drug effects* ; Male ; Cells, Cultured ; Tumor Necrosis Factor-alpha/metabolism*

This study aimed to investigate the effect of aucubin(AU) on injury of nucleus pulposus cells and extracellular matrix(ECM) degradation and its mechanism. The nucleus pulposus cell injury model was established by interleukin-1β(IL-1β) and treated with AU or phosphatidylinositol 3-kinase(PI3K) inhibitor LY294002. CCK-8 experiment was conducted to test cell proliferation. EdU staining method was employed to detect cell injury. Flow cytometry was used to detect cell apoptosis. Western blot was used to detect protein levels of cleaved-caspase-3, B-cell lymphoma(Bcl-2), Bcl-2 associated X protein(Bax), type Ⅱ collagen(collagen Ⅱ), aggregation proteoglycans(aggrecan), PI3K, and mammalian target of rapamycin(mTOR). qPCR was used to detect the rRNA level of 5S, 18S, and 28S. Ethynyluridine was used to label nascent RNA. The results showed that IL-1β could significantly cause injury of nucleus pulposus cells and increase the apoptosis rate of nucleus pulposus cells and the expression of apoptosis protein cleaved-caspase-3 and Bax. At the same time, IL-1β down-regulated the expression of anti-apoptotic protein Bcl-2 and collagen Ⅱ and aggrecan, the main components of ECM. On this basis, AU intervention could improve the injury of nucleus pulposus cells, reduce the apoptosis of nucleus pulposus cells and the expression of cleaved-caspase-3 and Bax, and increase the expression of Bcl-2, collagen Ⅱ, and aggrecan. Compared with IL-1β, AU could up-regulate the phosphorylation level of PI3K and mTOR, and LY294002 could reverse the injury of nucleus pulposus cells and improve ECM degradation induced by AU. In addition, AU also could save lowered rRNA levels of 5S, 18S, and 28S induced by IL-1β and improve RNA synthesis. PI3K inhibitor LY294002 intervention could reduce the promoting effect of AU on ribosome biogenesis. The above results suggest that AU can improve the injury of nucleus pulposus cells and ECM degradation, and its mechanism of action is related to its activation of the PI3K/mTOR pathway to promote ribosome biogenesis.
Nucleus Pulposus/cytology* ; Extracellular Matrix/drug effects* ; Animals ; Iridoid Glucosides/pharmacology* ; Apoptosis/drug effects* ; Interleukin-1beta/metabolism* ; Phosphatidylinositol 3-Kinases/genetics* ; Rats ; Cell Proliferation/drug effects* ; TOR Serine-Threonine Kinases/genetics* ; Rats, Sprague-Dawley ; Humans ; Signal Transduction/drug effects* ; Caspase 3/genetics* ; Proto-Oncogene Proteins c-bcl-2/genetics*

This study investigated the mechanism by which kaempferol(KAE) affected intervertebral disc degeneration(IDD) through the p38 mitogen-activated protein kinase(p38 MAPK) signaling pathway. Rats were randomly divided into five groups: control group, model group, low-dose KAE group, medium-dose KAE group, and high-dose KAE group. An IDD model was established by needle puncture of the caudal intervertebral discs. Four weeks post-surgery, the rats were administered KAE via gavage for 8 consecutive weeks. Magnetic resonance imaging(MRI) was performed, and samples were collected. In vitro, an inflammation model of nucleus pulposus cells(NPCs) induced by tumor necrosis factor-alpha(TNF-α) was constructed. Anisomycin was used to activate the p38 MAPK signaling pathway. NPCs were divided into blank, model, KAE, agonist, and KAE + agonist groups. After 1 day of treatment, cell proliferation activity was assessed using the CCK-8. Protein expression levels were determined by Western blot, and mRNA expression was measured by real-time quantitative polymerase chain reaction. Cell apoptosis was detected by TUNEL staining, and immunofluorescence staining was used to detect type Ⅱ collagen and matrix metalloproteinase 3(MMP3). In vivo results indicated significant improvement in the degree of IDD in the treatment groups compared to the model group, with the medium-dose group showing more pronounced therapeutic effects than the low-and high-dose groups. In vitro results demonstrated that KAE treatment significantly enhanced NPC proliferation activity, down-regulated the expression levels of Bcl-2-associated X protein(Bax), interleukin-6(IL-6), interleukin-17A(IL-17A), MMP3, and a disintegrin and metalloproteinase with thrombospondin motifs 5, and inhibited the phosphorylation of p38 MAPK pathway-related proteins. Activation of the p38 MAPK signaling pathway by anisomycin reduced the therapeutic effects of KAE. The study concluded that KAE could improve the proliferation activity of degenerated NPCs, reduce inflammation levels, and slow the progression of IDD in rats, and the mechanism was likely related to the regulation of the p38 MAPK signaling pathway.
Animals ; p38 Mitogen-Activated Protein Kinases/genetics* ; Kaempferols/pharmacology* ; Intervertebral Disc Degeneration/genetics* ; Rats ; Rats, Sprague-Dawley ; Male ; Apoptosis/drug effects* ; Cell Proliferation/drug effects* ; Nucleus Pulposus/drug effects* ; Signal Transduction/drug effects* ; Humans ; MAP Kinase Signaling System/drug effects*

This paper aims to investigate the effects and mechanisms of adipose-derived stem cells-exosomes(ADSCs-exos) toge-ther with aucubin in protecting human-derived nucleus pulposus cells(NPCs) from inflammatory injury, senescence, and apoptosis. The tert-butyl hydroperoxide(TBHP)-induced NPCs were assigned into normal, model, aucubin, ADSCs-exos, and aucubin+ADSCs-exos groups. The cell viability was examined by cell counting kit-8(CCK-8), cell proliferation by EdU staining, cell senescence by senescence-associated-β-galactosidase(SA-β-Gal), and cell cycle and apoptosis by flow cytometry. Enzyme-linked immunosorbent assay was employed to examine the expression of interleukin-1β(IL-1β), IL-10, and tumor necrosis factor-α(TNF-α). Real-time fluorescence quantitative PCR and Western blot were employed to determine the mRNA and protein levels of aggregated proteoglycan(aggrecan), type Ⅱ collagen alpha 1(COL2A1), Toll-like receptor 4(TLR4), and nuclear factor-kappa B(NF-κB). The results showed that compared with the model group, the aucubin or ADSCs-exos group showed enhanced viability and proliferation of NPCs, decreased proportion of G_0/G_1 phase cells, increased proportion of S phase cells, reduced apoptosis and proportion of cells in senescence, lowered IL-1β and TNF-α levels, elevated IL-10 level, down-regulated mRNA and protein levels of TLR4 and NF-κB, and up-regulated mRNA and protein levels of aggrecan and COL2A1. Compared with the aucubin or ADSCs-exos group, the aucubin+ADSCs-exos combination further increased the viability and proliferation of NPCs, decreased the proportion of G_0/G_1 phase cells, increased the proportion of S phase cells, reduced the apoptosis and proportion of cells in senescence, lowered the IL-1β and TNF-α levels, elevated the IL-10 level, down-regulated the mRNA and protein levels of TLR4 and NF-κB, and up-regulated the mRNA and protein levels of aggrecan and COL2A1. In summary, both aucubin and ADSCs-exos could exert protective effects by inhibiting inflammatory responses, reducing apoptosis and senescence of NPCs, improving cell viability and proliferation as well as extracellular matrix synthesis, which may be associated with the inhibition of TLR4/NF-κB signaling pathway activation. The combination of both plays a synergistic role in the protective effects.
Humans ; NF-kappa B/metabolism* ; Interleukin-10 ; Nucleus Pulposus/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Aggrecans/metabolism* ; Toll-Like Receptor 4/metabolism* ; RNA, Messenger/metabolism*

OBJECTIVE: To study the clinical manifestations and treatment of intervertebral space infection after percutaneous lumbar radiofrequency ablation of nucleus pulposus. METHODS: A retrospective analysis was performed of 496 patients who underwent percutaneous lumbar disc decompression using low-temperature plasma radiofrequency ablation nucleus pulposus from June 2009 to June 2019. Six patients had lumbar infection, and the infection rate was 1.21%. All patients were male, ranging in age from 20 to 61 years old. Three patients underwent single segment radiofrequency ablation, two patients underwent dual segments ablation;and one patient underwent three segment ablation, totaling 10 intervertebral discs. One patient was complicated with type 2 diabetes before operation. The interval between infection occurrence ranged from 21 to 65 days. RESULTS: All 6 patients were followed up, and the duration ranged from 18 to 40 months, with an average of 24 months. Among them, 2 patients presented with symptoms of low back pain accompanied by fever, and imaging examination showed intervertebral space infection accompanied by abscess. In addition, 4 patients experienced low back pain but no fever, and MRI showed abnormal signals of the infected intervertebral endplate or vertebral body. One patient showed staphylococcus aureus in blood culture, while the remaining 5 patients showed negative bacterial culture. All the patients were treated with antibiotics after diagnosis. Four patients were treated with conservative management to control infection;1 patient was treated with debridement of posterior lumbar infection focus, and 1 patient was treated with debridement of posterior lumbar infection focus combined with interbody fusion and internal fixation. CONCLUSION The occurrence of intervertebral space infection during lumbar radiofrequency ablation nucleoplasty should be given sufficient attention. Strict aseptic technique, avoiding repeated multi segment puncture, realizing early detection and treatment, and selecting appropriate treatment methods according to the severity of infection is the guarantee of achieving curative effect.
Humans ; Male ; Young Adult ; Adult ; Middle Aged ; Female ; Low Back Pain ; Nucleus Pulposus ; Diabetes Mellitus, Type 2 ; Retrospective Studies ; Spinal Puncture

Traditional Chinese medicine has unique advantages in the treatment of degenerative bone and joint diseases, and its widely used in clinical practice. In recent years, many scholars have conducted a large number of basic studies on the delay of intervertebral disc degeneration by herbal compound and monomeric components from different perspectives. In order to further elucidate its mechanism of action, this paper summarizes the in vivo and in vitro experimental studies conducted at the level of both herbal compound and single components, respectively, in order to provide references for the basic research on the treatment of lumbar intervertebral disc degeneration by Chinese medicine. A summary shows that commonly used herbal compound prescriptions include both classical prescriptions such as Duhuo Jisheng Decoction, as well as clinical experience prescriptions such as Yiqi Huoxue Recipe. Angelicae Sinensis Radix, Chuanxiong Rhizoma, Rehmanniae Radix Praeparata, Achyranthis Bidentatae Radix, and Eucommiae Cortex were used most frequently. Tonic for deficiency and blood stasis activators were used most frequently. The most utilized monomeric components include icariin, ginsenoside Re, salvianolic acid B and aucubin. The main molecular mechanisms by which herbal compound and monomeric components delay of lumbar intervertebral disc degeneration include improving the intervertebral disc microenvironment, promoting the synthesis of aggregated proteoglycans and type Ⅱ collagen in the intervertebral disc, reducing the degradation of the extracellular matrix, and inhibiting apoptosis in the nucleus pulposus cells, etc. The main signaling pathways involved include Wnt/β-catenin signaling pathway, MAPK-related signaling pathway, mTOR signaling pathway, Fas/FasL signaling pathway, PI3 K/Akt signaling pathway, NF-κB signaling pathway, JAK/STAT signaling pathway, and hedgehog signaling pathway, etc.
China ; Drugs, Chinese Herbal/therapeutic use* ; Hedgehog Proteins/metabolism* ; Humans ; Intervertebral Disc Degeneration/metabolism* ; Nucleus Pulposus/metabolism* ; Wnt Signaling Pathway