ABSTRACT Background Spinal cord injury (SCI) is a severe condition leading to significant disability and high mortality. The role of the secreted phosphoprotein 1 (SPP1) signaling pathway in SCI, which is quickly activated after injury, is critical for intercellular communication but remains poorly understood. Aims This study aimed to explore the function and regulatory mechanisms of the SPP1 signaling pathway in SCI and investigate its potential as a therapeutic target for improving functional recovery after injury. Materials and Methods Single‐cell RNA sequencing (scRNA‐seq) was employed to identify ligands and receptors of the SPP1 signaling pathway, particularly in microglia/macrophages. Recombinant SPP1 (rSPP1) was used in vitro and in vivo to assess its effects on neuronal maturation, mitochondrial energy in axons, and functional recovery after SCI. Pseudotime analysis was conducted to examine the role of Spp1 in microglial activation and proliferation. DNA‐pulldown and in vitro experiments were performed to investigate the upstream regulatory proteins of Spp1 . Results The SPP1 signaling pathway is primarily localized in microglia after SCI, with rSPP1 promoting neuronal maturation and enhancing mitochondrial function in axons. Injection of rSPP1 into the injured spinal cord resulted in significant improvement in functional recovery. Pseudotime analysis indicated that Spp1 is involved in the activation and proliferation of microglia. Histone H4 lysine 12 lactylation (H4K12la) was found to promote the transcription of Spp1 in reprogrammed microglia postinjury. Discussion Our findings reveal a novel regulatory mechanism involving Spp1 in SCI, particularly its role in microglial activation, mitochondrial function, and glycolytic reprogramming. This new insight provides a deeper understanding of its contribution to the injury response. Conclusion This study uncovers a previously unreported mechanism of Spp1 in SCI, offering a potential therapeutic target for SCI.

Objectives Posterior ring apophysis separation (PRAS) associated with lumbar disc herniation (LDH) is a relatively rare form of disc herniation. This study aims to evaluate the clinical effectiveness of unilateral biportal endoscopic discectomy (UBE) and percutaneous endoscopic lumbar discectomy (PELD) in the treatment of PRAS with LDH. Methods We enrolled 41 patients who met the inclusion criteria to undergo either UBE (15 cases) or PELD (26 cases) between October 2022 and October 2023. Perioperative evaluation parameters included mean operative time, hemoglobin (Hb) loss, length of stay (LOS), and postoperative complications. Outcomes were assessed at admission, as well as at 1, 3, and 6 months postsurgery using the Visual Analog Scale (VAS) and the Oswestry Disability Index (ODI). Additionally, we evaluated the results according to the modified MacNab criteria. Results Both groups demonstrated improvements in postoperative VAS and ODI scores. However, there were no significant differences between the 2 groups in VAS and ODI scores before surgery, or at 1, 3, and 6 months postsurgery. Additionally, no notable differences were observed in the modified MacNab criteria. The UBE group experienced greater Hb loss, longer mean operative time, and increased LOS compared to the PELD group. Furthermore, 2 patients in the PELD group reported recurrence, while one patient in the UBE group experienced a dural tear. Conclusions UBE and PELD possess strong clinical effectiveness for treating PRAS with LDH. Although the UBE group had a longer mean operative time and LOS, with more Hb loss, the UBE group had a lower recurrence rate. Therefore, UBE remains safe and innovative for the treatment of PRAS with LDH.

The use of injectable hydrogels represents a viable approach for enhancing neural repair and promoting functional restoration after spinal cord trauma. Nevertheless, the current performance of these materials is not yet optimal and further optimization is necessary. Engineering a cell-free hydrogel delivery system with sustained anti-inflammatory capacity is of great relevance for advancing therapeutic strategies in spinal cord injury (SCI). Here, we fabricated a biomimetic hydrogel incorporating spermidine to modulate the post-injury immune microenvironment. The material was constructed by photocrosslinking aldehyde-modified methacrylated hyaluronic acid (AHAMA) through dynamic Schiff base chemistry, enabling controlled and prolonged spermidine release. This hydrogel demonstrated expedited gelation kinetics coupled with stable and exceptional mechanical properties. In addition, the cell-free AHAMA hydrogels have substantially enhanced the cellular-matrix interactions and facilitated neuronal integration. Furthermore, the spermidine-loaded hydrogel exerted potent immunomodulatory effects by suppressing M1 macrophage (classically activated macrophage) polarization through activation of STAT1 (signal transducer and activator of transcription 1) signaling axis. In vivo assessments demonstrated enhanced neuroregeneration and axonal elongation at the lesion site, which translated into marked improvements in locomotor function in the murine SCI model. Collectively, the combination of sustained spermidine release with a bioinspired, cell-free AHAMA hydrogel scaffold offers an effective therapeutic approach to modulate inflammation and enhance tissue repair in the injured spinal cord environment.

Improving the function of the blood-spinal cord barrier (BSCB) benefits the functional recovery of mice following spinal cord injury (SCI). The death of endothelial cells and disruption of the BSCB at the injury site contribute to secondary damage, and the ubiquitin-proteasome system is involved in regulating protein function. However, little is known about the regulation of deubiquitinated enzymes in endothelial cells and their effect on BSCB function after SCI. We observed that Sox17 is predominantly localized in endothelial cells and is significantly upregulated after SCI and in LPS-treated brain microvascular endothelial cells. In vitro Sox17 knockdown attenuated endothelial cell proliferation, migration, and tube formation, while in vivo Sox17 knockdown inhibited endothelial regeneration and barrier recovery, leading to poor functional recovery after SCI. Conversely, in vivo overexpression of Sox17 promoted angiogenesis and functional recovery after injury. Additionally, immunoprecipitation-mass spectrometry revealed the interaction between the deubiquitinase UCHL1 and Sox17, which stabilized Sox17 and influenced angiogenesis and BSCB repair following injury. By generating UCHL1 conditional knockout mice and conducting rescue experiments, we further validated that the deubiquitinase UCHL1 promotes angiogenesis and restoration of BSCB function after injury by stabilizing Sox17. Collectively, our findings present a novel therapeutic target for treating SCI by revealing a potential mechanism for endothelial cell regeneration and BSCB repair after SCI.

OBJECTIVES: To compare magnetic resonance (MR) short T1 inversion recovery (STIR) sequence with MR T2weighted (T2W) sequence for detecting increased signal intensity (ISI) and assessing outcomes of ISI in cervical spondylotic myelopathy (CSM). METHODS: Data of patients with CSM who showed ISI on MR imaging and had undergone cervical spine surgery were retrospectively reviewed. STIR and T2W images were examined to assess signal intensity ratio (SIR), length and grading of the ISI, maximal spinal cord compression, canal narrowing ratio, and ligamentum flavum hypertrophy. The patients were divided into good and poor groups based on their outcomes. c 2 tests and variance analysis were used to assess intergroup differences. Univariate and multivariate logistic regression analyses were performed to identify risk factors for poor outcomes, and receiver operating characteristic curves were plotted to detect prognostic effects. RESULTS: SIR and ISI lengths were significantly different between the STIR and T2 images. In the univariate logistic regression analysis, age, diabetes, SIR T2 , SIR STIR , and ISI STIR grading were significant factors. Accordingly, in the multivariate logistic regression analysis, age, diabetes, SIR T2 , and SIR STIR were included in the model. Among patients with diabetes, we observed a significant difference between SIR T2 and SIR STIR . CONCLUSIONS: The STIR sequence demonstrated superior capability to the T2W sequence in detecting ISI; however, there was no obvious difference in predicted outcomes. STIR sequence has a better prognostic value than T2W sequence in patients with diabetes who have CSM. ISI grading based on the STIR sequence may be a clinically valuable indicator.

Traumatic spinal cord injury (SCI) is a catastrophic damage that causes changes in its motor function permanently. Reactive astrocytes is a pathological feature of spinal cord injury (SCI). Exosomes take part in the transportation of miRNAs and play an a novel platform for intercellular communication in the central nervous system (CNS). However, the effect of miRNAs in Neuronal stem cells (NSCs) derived exosomes in SCI was unknown. in vivo SCI model and in vitro experiments were performed to investigate the effects and mechanisms of exosomes. NSCs-derived exosomes promoted motor function recovery by shifting astrocytes from the A1 to A2 phenotype. microarray analysis of miRNA showed that miR-31-5p was the most enriched in NSCs-derived exosomes. Bioinformatics, RIP, and luciferase activity predicted IL34 was the target downstream gene of miR-31-5p. Western bloting examined IL34/STAT3 signaling pathway involved in modulating atrocities by the exosomal miR-31-5p. Rescue experiments evaluate that exosomal miR-31-5p shifting astrocytes A1 to A2 phenotype by inhibiting IL34/STAT3 signaling cascades, and promoted motor function recovery in mice after SCI.

Ischemia-reperfusion injury is the second most common injury of the spinal cord and has the risk of neurological dysfunction and paralysis, which can seriously affect patient quality of life. Salidroside (Sal) is an active ingredient extracted from Herba Cistanche with a variety of biological attributes such as antioxidant, antiapoptotic, and neuroprotective activities. Moreover, Sal has shown a protective effect in ischemia-reperfusion injury of the liver, heart, and brain, but its effect in ischemia-reperfusion injury of the spinal cord has not been elucidated. Here, we demonstrated for the first time that Sal pretreatment can significantly improve functional recovery in mice after spinal cord ischemia-reperfusion injury and significantly inhibit the apoptosis of neurons both in vivo and in vitro . Neurons have a high metabolic rate, and consequently, mitochondria, as the main energy-supplying suborganelles, become the main injury site of spinal cord ischemia-reperfusion injury. Mitochondrial pathway-dependent neuronal apoptosis is increasingly confirmed by researchers; therefore, Sal’s effect on mitochondria naturally attracted our attention. By means of a range of experiments both in viv o and in vitro , we found that Sal can reduce reactive oxygen species production through antioxidant stress to reduce mitochondrial permeability and mitochondrial damage, and it can also enhance the PINK1-Parkin signaling pathway and promote mitophagy to eliminate damaged mitochondria. In conclusion, our results show that Sal is beneficial to the protection of spinal cord neurons after ischemia-reperfusion injury, mainly by reducing apoptosis associated with the mitochondrial-dependent pathway, among which Sal’s antioxidant and autophagy-promoting properties play an important role.

Osteosarcoma (OS) is a malignant bone tumor which occurs mainly in adolescents with frequent pulmonary metastasis and a high mortality rate. Accumulating evidence has indicated that microRNAs (miRNAs) play a vital role in various tumors by modulating target genes as well as signal pathways, and aberrant expression of miRNAs may contribute to OS progression. This study aimed to determine the association between miR-210-5p expression and OS progression and to investigate its potential underlying mechanism. Using reverse transcription-polymerase chain reaction (RT-PCR), miR-210-5p was found to be upregulated in clinical OS specimens and cell lines. Further functional analysis demonstrated that miR-210-5p promoted epithelial–mesenchymal transition (EMT) and induced oncogenic autophagy. Luciferase reporter assay, RNA-ChIP, and western blot analysis confirmed that PIK3R5, an essential regulator in the AKT/mTOR signaling pathway, is a target downstream gene of miR-210-5p. Overexpression or knockdown of PIK3R5 reversed the functional role of overexpression or knockdown of miR-210-5p, respectively. Silencing autophagy-related gene 5 (ATG5) abolished the functional effects of miR-210-5p upregulation or PIK3R5 knockdown in OS cells. In vivo, miR-210-5p overexpression promoted OS tumor growth and pulmonary metastasis. Taken together, our results demonstrated that miR-210-5p promoted EMT and oncogenic autophagy by suppressing the expression of PIK3R5 and regulating the AKT/mTOR signaling pathway. Therefore, inhibition of miR-210-5p may represent a promising treatment for OS.

Abstract Objective This study aims to explore the effects of exosomes derived from G protein-coupled receptor kinase 2 interacting protein 1 (GIT1)-overexpressing bone marrow mesenchymal stem cell (GIT1-BMSC-Exos) on the treatment of traumatic spinal cord injury (SCI) in a rat model. Methods All the rats underwent a T10 laminectomy. A weight-drop impact was performed using a 10-g rod from a height of 12.5 mm except the sham group. Rats with SCI were distributed into three groups randomly and then treated with tail vein injection of GIT1-BMSCs-Exos, BMSCs-Exos and PBS, respectively. The effects of GIT1-Exos on glutamate (GLU)-induced apoptosis in vitro were also evaluated by TUNEL staining. Results The results showed that rats treated with GIT1-BMSCs-Exos had better functional behavioral recovery than those treated with PBS or BMSCs-Exos only. The overexpression of GIT1 in BMSCs-Exos not only restrained glial scar formation and neuroinflammation after SCI, but also attenuated apoptosis and promoted axonal regeneration in the injured lesion area. Neuronal cell death induced by GLU was controlled remarkably in vitro as well. Conclusion In conclusion, our study suggested that the application of GIT1-BMSCs-Exos may provide a novel avenue for traumatic SCI treatment.

OBJECTIVE:Lumbar disk herniation (LDH) is a complex condition based on lumbar disk degeneration (LDD). Previous studies have shown that genetic factors are highly associated with the severity and risk for LDH. This case-control study was aimed to evaluate the association between the matrix metalloproteinase (MMP)-3 gene rs591058 C/T polymorphism and LDH risk in a southern Chinese population.METHODS:A total of 231 LDH patients and 312 healthy controls were recruited in this study. Genotyping was analyzed using a standard polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP).RESULTS:It was observed that TT genotype or T allele carriers of the MMP-3 gene rs591058 C/T polymorphism was more likely associated with an increased risk for LDH. Subgroup analyses showed the following characteristics increased the risk for LDH: female sex; cigarette smoking; and alcohol consumption. Furthermore, individuals with high whole body vibration, bending/twisting, and lifting were associated with an increased risk for LDH.CONCLUSION:Taken together, these data indicated that the MMP-3 gene rs591058 C/T polymorphism was associated with an increased risk for LDH. The MMP-3 gene rs591058 C/T polymorphism might serve as a clinical indicator and marker for LDH risk in the Chinese population.

Transplantation of mesenchymal stem cells (MSCs) has been considered an effective therapeutic treatment for a variety of diseases including bone fracture. However, there are associated complications along with MSCs transplantation. There is evidence to show that exosomes (Exos) derived from MSCs exert a similar paracrine function. In addition, repair capabilities of MSCs decline with age. Hence, this study aims to confirm whether the Exos protective function on osteogenic differentiation and fracture healing from aged MSCs was attenuated. This information was used in order to investigate the underlying mechanism. MSCs were successfully isolated and identified from young and aged rats, and Exos were then obtained. Aged-Exos exhibited significantly attenuated effects on MSCs osteogenic differentiation in vitro and facture healing in vivo. Using miRNA array analysis, it was shown that miR-128-3p was markedly upregulated in Aged-Exos. In vitro experiments confirmed that Smad5 is a direct downstream target of miR-128-3p, and was inhibited by overexpressed miR-128-3p. A series gain- and loss- function experiment indicated that miR-128-3P serves a suppressor role in the process of fracture healing. Furthermore, effects caused by miR-128-3P mimic/inhibitor were reversed by the application of Smad5/siSmad5. Taken together, these results suggest that the therapeutic effects of MSCs-derived Exos may vary according to differential expression of miRNAs. Exosomal miR-128-3P antagomir may act as a promising therapeutic strategy for bone fracture healing, especially for the elderly.

PURPOSE:The endplate defects (EDs), Modic changes (MCs), disc degeneration (DD), facet orientation (FO), and facet tropism (FT) were demonstrated to be related to the low back pain (LBP). The aim of this study was to investigate possible correlations between them.METHODS:75 patients were reviewed to evaluate the degenerative change in vertebral bodies (EDs and MCs), intervertebral discs (DD), and facet joint degeneration (FO and FT). All patients were categorized into four groups based on the grade of EDs. Clinical outcomes were evaluated with the visual analog scale (VAS) and Oswestry disability index (ODI) before and after surgery.RESULTS:There was no difference between the four groups in baseline characteristics except for gender and weight. FT is positively correlated with FO. The same rule exists between EDs, the size of MCs II, FO (left) and FO (right), and VAS and ODI. The grade of EDs is positively correlated with the grade of DD. L4-L5 can bear more load than other levels; thus, the grade of EDs is higher than that of other lumbar levels. The preoperative LBP was relieved in all groups in varying degrees. The change of pain and dysfunction is inversely proportional to the grade of EDs in the general trend.CONCLUSION:The relationship between weight, gender, and disc degeneration provided a mechanism by which increasing weight can predispose to DD. Different grades of EDs had different effects on patients with LBP. There was a significant correlation between EDs, MCs II, DD, FT, and FO.

目的 比较在前路颈椎椎间盘切除融合术(ACDF)中应用零切迹自稳型颈椎融合器(ROI-C)与融合器并钛板固定治疗颈椎病的临床疗效、术后吞咽困难及远期邻近节段骨化的发生率.方法 回顾性分析2013年5月—2015年5月行ACDF治疗的108例颈椎病患者临床资料,其中59例应用ROI-C固定(A组),49例应用融合器并钛板固定(B组).在术前、术后3个月及末次随访时,测量颈椎Cobb角、颈椎弓深、上位邻近节段椎间隙高度,并采用日本骨科学会(JOA)评分、颈椎功能障碍指数(NDI)评估患者颈椎功能.分别采用Odom法及Vaccraro标准进行手术疗效评定,记录2组术后吞咽困难及末次随访时邻近节段骨化发生情况.结果 与术前比较,2组术后JOA评分明显提高,NDI明显降低,颈椎Cobb角和弓深明显增大,差异均有统计学意义(P<0.05);2组术后上位邻近节段椎间隙高度与术前比较差异均无统计学意义(P>0.05).组间比较,术后JOA评分、NDI、手术疗效优良率和同时间点影像学参数差异均无统计学意义(P>0.05).与B组相比,A组吞咽困难发生率和严重程度更低、持续时间更短,邻近节段骨化发生率也更低,差异有统计学意义(P<0.05).结论 在ACDF中应用ROI-C治疗颈椎病安全、有效,与融合器并钛板固定相比,ROI-C能减少术后吞咽困难和邻近节段骨化的发生率.

G protein-coupled receptor kinase 2 interacting protein-1 (GIT1) is a scaffold protein that plays a vital role in bone modeling and remodeling during osteogenesis coupled with angiogenesis. Recent studies have shown that a specialized subset of vascular endothelium strongly positive for CD31 and Endomucin (CD31(hi)Emcn(hi)) is coupled with anabolic bone formation. Based on our previous finding that GIT1 knockout (GIT1 KO) mice have impaired angiogenesis and bone formation, we hypothesized that GIT1 affects formation of the CD31(hi)Emcn(hi) vessel subtype. In the current study, GIT1 knockout (GIT1 KO) mice displayed a significant decrease in trabecular bone mass and CD31(hi)Emcn(hi) vessel number, compared to their wild-type counterparts. In the fracture healing mouse model, GIT1 KO mice contained a lower number of CD31(hi)Emcn(hi) vessels in fracture callus at days 7 and 14. However, no significant differences in the number of preosteoclasts in bone marrow, trabecular bone and callus in GIT1 KO mice were observed, compared with wild-type mice. Notably, concentrations of serum platelet-derived growth factor-BB(PDGF-BB) secreted by preosteoclasts associated with CD31(hi)Emcn(hi) vessel formation were lower in GIT1 KO mice. In addition, PDGF-BB-associated expression of phosphorylated extracellular signal regulated kinase- 1/2 (ERK1/2) and specificity protein 1 (SP1) was significantly decreased in preosteoclasts of GIT1 KO mice. These results collectively suggest that GIT1 is a critical participant in formation of the CD31(hi)Emcn(hi) vessel subtype, highlighting a novel biologic function of this scaffold protein in preosteoclasts.

Increasing evidence has suggested that paracrine mechanisms might be involved in the underlying mechanism of mesenchymal stem cells (MSCs) transplantation, and exosomes are an important component of this paracrine role. However, MSCs are usually exposed to normoxia (21% O2) in vitro but experience large differences in oxygen concentration in the body under hypoxia. Indeed, hypoxic precondition of MSCs can enhance their paracrine effects. The main purpose of this study was to determine whether exosomes derived from MSCs under hypoxia (Hypo-Exos) exhibit greater effects on bone fracture healing than those under normoxia (Exos). Using in vivo bone fracture model and in vitro experiments including cell proliferation assay, cell migration assay and so on, we confirmed that Hypo-Exos administration promoted angiogenesis, proliferation and migration to a greater extent when compared to Exos. Furthermore, utilizing a series in vitro and in vivo gain and loss of function experiments, we confirmed a functional role for exosomal miR-126 in the process of bone fracture healing. Meanwhile, we found that knockdown of hypoxia inducible factor 1 (HIF-1α) resulted in a significant decrease of miR-126 in MSCs and exosomes, thereby abolishing the effects of Hypo-Exos. In conclusion, our results demonstrated a mechanism by which Hypo-Exos promote bone fracture healing through exosomal miR-126. Moreover, hypoxia preconditioning mediated enhanced production of exosomal miR-126 through the activation of HIF-1α. Hypoxia preconditioning represents an effective and promising method for the optimization of the therapeutic actions of MSC-derived exosomes for bone fracture healing. STATEMENT OF SIGNIFICANCE: Studies have confirmed that transplantation of exosomes exhibit similar therapeutic effects and functional properties to directly-transplanted stem cells but have less significant adverse effects. However, during in vitro culture conditions, MSCs are usually exposed to normoxia (21% O2) which is very different to the oxygen concentrations found in the body under natural physiological conditions. Our results demonstrated a mechanism by which Hypo-Exos promote bone fracture healing through exosomal miR-126 and the SPRED1/Ras/Erk signaling pathway. Moreover, hypoxia preconditioning mediated enhanced production of exosomal miR-126 through the activation of HIF-1α. Hypoxia preconditioning represents an effective and promising method for the optimization of the therapeutic actions of MSC-derived exosomes for bone fracture healing.

The neuronal apoptosis program associated with spinal cord injury (SCI) has a severe impact on spinal cord function, which leads to further secondary and permanent neuronal damage that may cause irreparable damage to the central nervous system. Activation of the Wnt/β-catenin signaling pathway is effective in reducing apoptosis and preventing SCI. Harpagide is one of the main active constituents of the iridoid class of molecules, which have neuroprotective effects after SCI. In this study, we demonstrated that harpagide attenuated neuronal apoptosis via activation of the Wnt/β-catenin signaling pathway. This resulted in a promotion of axonal regeneration and an inhibition of glial scar formation, which ultimately improved functional behavioral recovery after SCI in rats. Specifically, the administration of harpagide after SCI increased the expression levels of β-catenin, c-myc and cyclin D1 proteins in spinal cord neurons, as well as increased the number of motor neurons and reduced the size of the SCI lesion area. In addition, the administration of harpagide after SCI also decreased the protein expression levels as well as the number of cells immuno-stained for the pro-apoptotic proteins Bax and cleaved-caspase 3. The expression level of the anti-apoptotic protein Bcl-2 was also increased. When the Wnt /β-catenin signaling pathway was inhibited, a weakened anti-apoptotic effect of harpagide was observed. Additionally, the application of harpagide led to an increase in NF200 staining and a reduction in GFAP staining in the SCI injury site. In summary, our study suggested that harpagide may be a promising drug for the treatment of SCI.

Spinal cord injury (SCI) can cause severe irreversible motor dysfunction and even death. Neural stem cell (NSC) transplantation can promote functional recovery after acute SCI in experimental animals, but numerous issues, including low-transplanted cell survival rate, cell de-differentiation, and tumor formation need to be resolved before routine clinical application is feasible. Recent studies have shown that transplanted stem cells facilitate regeneration through release of paracrine factors. Small extracellular vesicles (sEVs), the smallest known membrane-bound nanovesicles, are involved in complex intercellular communication systems and are an important vehicle for paracrine delivery of therapeutic agents. However, the application of NSC-derived small extracellular vesicles (NSC-sEVs) to SCI treatment has not been reported. We demonstrate that NSC-sEVs can significantly reduce the extent of SCI, improve functional recovery, and reduce neuronal apoptosis, microglia activation, and neuroinflammation in rats. Furthermore, our study suggests that NSC-sEVs can regulate apoptosis and inflammatory processes by inducing autophagy. In brief, NSC-sEVs increased the expression of the autophagy marker proteins LC3B and beclin-1, and promoted autophagosome formation. Following NSC-sEV infusion, the SCI area was significantly reduced, and the expression levels of the proapoptotic protein Bax, the apoptosis effector cleaved caspase-3, and the pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 were significantly reduced, whereas the expression level of the anti-apoptotic protein Bcl-2 was upregulated. In the presence of the autophagy inhibitor 3MA, however, these inhibitory effects of NSC-sEVs on apoptosis and neuroinflammation were significantly reversed. Our results show for the first time that NSC-sEV treatment has the potential to reduce neuronal apoptosis, inhibit neuroinflammation, and promote functional recovery in SCI model rats at an early stage by promoting autophagy.

Neural stem cell-derived small extracellular vesicles (NSC-sEVs) play an important role in the repair of tissue damage. Our previous in vitro and in vivo studies found that preconditioning with NSC-sEVs promoted the recovery of functional behaviors following spinal cord injury by activating autophagy. However, the underlying mechanisms for such observations remain unclear. In this study, we further explored the mechanisms by which NSC-sEVs repair spinal cord injury via autophagy. We found that NSC-sEVs contain 14-3-3t protein, of which the overexpression or knockdown enhanced and decreased autophagy, respectively. In addition, 14-3-3t overexpression enhanced the anti-apoptotic and anti-inflammatory effects of NSC-sEVs, further promoting functional behavior recovery following spinal cord injury. The overexpression of 14-3-3t was used to further validate the in vivo results through a series of in vitro experiments. Conversely, knockdown of 14-3-3t attenuated the anti-apoptotic and anti-inflammatory effects of NSC-sEVs. Further studies also confirmed that NSC-sEVs increased Beclin-1 expression, with which 14-3-3t interacted and promoted its localization to autophagosome precursors. In this study, we found that NSC-sEVs deliver 14-3-3t, which interacts with Beclin-1 to activate autophagy. Our results indicate that 14-3-3t acts via a newly-discovered mechanism for the activation of autophagy by NSC-sEVs.

目的:比较钛板-融合器固定系统与插片式融合器对颈椎前路椎间盘摘除椎间融合术(anterior cervical discectomy and fusion,ACDF)的临床疗效与并发症.方法:共招募195例成年颈椎病患者,其中98例采用钛板-融合器系统(P组),97例采用插片式融合器(S组).对患者术前、术后的日本骨科协会(JOA)评分与颈椎功能障碍指数(NDI)进行评估.测量颈椎矢状位参数,并通过X线片进行比较,包括C2-C7 Cobb角、颈椎弓深与邻近椎间隙高度(头端与尾端),评估邻近节段骨化(adjacentlevel ossification development,ALOD)与吞咽困难等级.结果:两组患者术后X线片显示C2-C7 Cobb角与颈椎弓深值均大于术前(P＜0.05).P组患者的尾端椎间隙高度小于术前(P＜0.05).S组中有吞咽困难或ALOD的患者比例比P组低(P＜0.01).两组患者的JOA评分与NDI均有所改善,但恢复率无明显差异.结论:两组患者的长期临床疗效均令人满意,两种内固定对颈椎矢状序列均有改善,但两组间变化程度并无差异.钛板-融合器系统更易使手术节段头端邻近节段出现骨化,插片式融合器的优势在于可以降低吞咽困难和ALOD的发生率.