Targeting foamy macrophages by manipulating ABCA1 expression to facilitate lesion healing in the injured spinal cord

Spinal cord injury (SCI) triggers a complex cascade of events, including myelin loss, neuronal damage, neuroinflammation, and the accumulation of damaged cells and debris at the injury site. Infiltrating bone marrow derived macrophages (BMDMϕ) migrate to the epicenter of the SCI lesion, where they engulf cell debris including abundant myelin debris to become pro-inflammatory foamy macrophages (foamy Mϕ), participate neuroinflammation, and facilitate the progression of SCI. This study aimed to elucidate the cellular and molecular mechanisms underlying the functional changes in foamy Mϕ and their potential implications for SCI. Contusion at T10 level of the spinal cord was induced using a New York University (NYU) impactor (5 g rod from a height of 6.25 mm) in male mice. ABCA1, an ATP-binding cassette transporter expressed by Mϕ, plays a crucial role in lipid efflux from foamy cells. We observed that foamy Mϕ lacking ABCA1 exhibited increased lipid accumulation and a higher presence of lipid-accumulated foamy Mϕ as well as elevated pro-inflammatory response in vitro and in injured spinal cord. We also found that both genetic and pharmacological enhancement of ABCA1 expression accelerated lipid efflux from foamy Mϕ, reduced lipid accumulation and inhibited the pro-inflammatory response of foamy Mϕ, and accelerated clearance of cell debris and necrotic cells, which resulted in functional recovery. Our study highlights the importance of understanding the pathologic role of foamy Mϕ in SCI progression and the potential of ABCA1 as a therapeutic target for modulating the inflammatory response, promoting lipid metabolism, and facilitating functional recovery in SCI.

Comparing the osteogenesis outcomes of different lumbar interbody fusions (A/O/X/T/PLIF) by evaluating their mechano-driven fusion processes

BACKGROUND

In lumbar interbody fusion (LIF), achieving proper fusion status requires osteogenesis to occur in the disc space. Current LIF techniques, including anterior, oblique, lateral, transforaminal, and posterior LIF (A/O/X/T/PLIF), may result in varying osteogenesis outcomes due to differences in biomechanical characteristics.

METHODS

A mechano-regulation algorithm was developed to predict the fusion processes of A/O/X/T/PLIF based on finite element modeling and iterative evaluations of the mechanobiological activities of mesenchymal stem cells (MSCs) and their differentiated cells (osteoblasts, chondrocytes, and fibroblasts). Fusion occurred in the grafting region, and each differentiated cell type generated the corresponding tissue proportional to its concentration. The corresponding osteogenesis volume was calculated by multiplying the osteoblast concentration by the grafting volume.

RESULTS

TLIF and ALIF achieved markedly greater osteogenesis volumes than did PLIF and O/XLIF (5.46, 5.12, 4.26, and 3.15 cm3, respectively). Grafting volume and cage size were the main factors influencing the osteogenesis outcome in patients treated with LIF. A large grafting volume allowed more osteoblasts (bone tissues) to be accommodated in the disc space. A small cage size reduced the cage/endplate ratio and therefore decreased the stiffness of the LIF. This led to a larger osteogenesis region to promote osteoblastic differentiation of MSCs and osteoblast proliferation (bone regeneration), which subsequently increased the bone fraction in the grafting space.

CONCLUSION

TLIF and ALIF produced more favorable biomechanical environments for osteogenesis than did PLIF and O/XLIF. A small cage and a large grafting volume improve osteogenesis by facilitating osteogenesis-related cell activities driven by mechanical forces.

Integrated evaluation of biomechanical and biological properties of the biomimetic structural bone scaffold: Biomechanics, simulation analysis, and osteogenesis

A porous structure is essential for bone implants because it increases the bone ingrowth space and improves mechanical and biological properties. The biomimetically designed porous Voronoi scaffold can reconstruct the structure and function of cancellous bone; however, its comprehensive properties need to be investigated further. In this study, algorithms based on scaling factors were used to design the Voronoi scaffolds. Classic approaches, such as computer-aided design and the implicit surface method, have been used to design Diamond, Gyroid, and I-WP scaffolds as controls. All scaffolds were prepared by selective laser melting of titanium alloys and three-dimensional printing. Mechanical tests, finite element analysis, and in vitro and in vivo experiments were performed to investigate the biomechanical, cytologic, and osteogenic performance of the scaffolds, while computational fluid dynamics simulations were used to explore the underlying mechanisms. Diamond scaffolds have a better loading capacity, and the mechanical behaviors and fluid flow of Voronoi scaffolds are similar to those of the human trabecular bone. Cells showed more proliferation and distribution on the Diamond and Voronoi scaffolds and exhibited evident differentiation on Gyroid and Voronoi scaffolds. Bone formation was apparent on the inner part of the Gyroid, the outer part of the I-WP, and the entire Diamond and Voronoi scaffolds. The hydrodynamic properties and stimulus response of cells influenced by the porous structure account for the varied biological performance of the scaffolds. The Voronoi scaffolds with bionic mechanical behavior and an appropriate hydrodynamic response exhibit evident cell growth and osteogenesis, making them preferable for porous structural bone implants.

Mechanism Study of Polydatin in Treating Spinal Cord Injury by Modulating Mitochondrial Membrane Potential Based on Network Pharmacology and Molecular Docking

Spinal cord injury (SCI) is one of the most devastating central lesions, and mitochondrial function plays an important role in secondary injury after SCI. Polydatin (PD) is a natural glycosylated precursor of resveratrol, showing mitochondrial preservation effects in the central nervous system. This study aimed to identify the hub target genes of PD on mitochondrial membrane potential (MMP) in SCI. A comprehensive analysis was performed on SCI-related genes, MMP-related genes, and PD targets screening from public databases. Differential expression analysis was conducted to identify differentially expressed genes (DEGs) in SCI. Gene set enrichment analysis (GSEA) and gene set variation analysis (GSVA) were employed to assess pathway enrichment. Protein-protein interaction (PPI) network analysis and molecular docking were conducted to identify key genes and evaluate the binding affinity between PD and hub genes. A total of 16,958 SCI-related genes, 2,786 MMP-related genes, 318 PD-related target genes, and 7229 DEGs were identified. Intersection analysis revealed 46 genes common to all four categories. GSEA and GSVA analysis identified significant enrichment of pathways associated with suppressed and activated SCI biological processes. The PPI network analysis identified seven core hub genes: EGFR, SRC, VEGFA, STAT3, ERBB2, TP53, and RHOA. Molecular docking revealed strong binding affinities between PD and ERBB2, EGFR, and RHOA. The findings based on computational investigation from public databases suggest that PD may have therapeutic potential for SCI by modulating MMP. These results contribute to the understanding of SCI pathogenesis and the development of novel therapeutic strategies.

Differential Expression of microRNAs and Target Genes Analysis in Olfactory Ensheathing Cell-derived Extracellular Vesicles Versus Olfactory Ensheathing Cells

INTRODUCTION

Olfactory ensheathing cells (OECs) are important transplantable cells for the treatment of spinal cord injury. However, information on the mechanism of OEC-derived extracellular vesicles (EVs) in nerve repair is scarce.

METHODS

We cultured OECs and extracted the OEC-derived EVs, which were identified using a transmission electron microscope, nanoparticle flow cytometry, and western blotting. High throughput RNA sequencing of OECs and OEC-EVs was performed, and the differentially expressed microRNAs (miRNAs) (DERs) were analyzed by bioinformatics. The target genes of DERs were identified using miRWalk, miRDB, miRTarBase, and TargetScan databases. Gene ontology and KEGG mapper tools were used to analyze the predicted target genes. Subsequently, the STRING database and Cytoscape software platform were used to analyze and construct miRNA target genes' protein-protein interaction (PPI) network.

RESULTS

Overall, 206 miRNAs (105 upregulated and 101 downregulated) were differentially expressed in OEC-EVs (p < 0.05;|log2 (fold change)|>2). Six DERs (rno-miR-7a-5p, rno-miR-143-3p, rno-miR-182, rno-miR-214-3p, rno-miR-434-5p, rno-miR-543-3p) were significantly up-regulated , and a total of 974 miRNAs target genes were obtained. The target genes were mainly involved in biological processes such as regulation of cell size, positive regulation of cellular catabolic process and small GTPase-mediated signal transduction; positive regulation of genes involved in cellular components such as growth cone, site of polarized growth, and distal axon; and molecular functions such as small GTPase binding and Ras GTPase binding. In pathway analysis, target genes regulated by six DERs were mainly enriched in axon guidance, endocytosis, and Ras and cGMP-dependent protein kinase G signaling pathways. Finally, 19 hub genes were identified via the PPI network.

CONCLUSION

Our study provides a theoretical basis for treating nerve repair by OEC-derived EVs.

Circadian clock regulator Bmal1 gates axon regeneration via Tet3 epigenetics in mouse sensory neurons

Axon regeneration of dorsal root ganglia (DRG) neurons after peripheral axotomy involves reconfiguration of gene regulatory circuits to establish regenerative gene programs. However, the underlying mechanisms remain unclear. Here, through an unbiased survey, we show that the binding motif of Bmal1, a central transcription factor of the circadian clock, is enriched in differentially hydroxymethylated regions (DhMRs) of mouse DRG after peripheral lesion. By applying conditional deletion of Bmal1 in neurons, in vitro and in vivo neurite outgrowth assays, as well as transcriptomic profiling, we demonstrate that Bmal1 inhibits axon regeneration, in part through a functional link with the epigenetic factor Tet3. Mechanistically, we reveal that Bmal1 acts as a gatekeeper of neuroepigenetic responses to axonal injury by limiting Tet3 expression and restricting 5hmC modifications. Bmal1-regulated genes not only concern axon growth, but also stress responses and energy homeostasis. Furthermore, we uncover an epigenetic rhythm of diurnal oscillation of Tet3 and 5hmC levels in DRG neurons, corresponding to time-of-day effect on axon growth potential. Collectively, our studies demonstrate that targeting Bmal1 enhances axon regeneration.

Nanoenzyme-Reinforced Multifunctional Scaffold Based on Ti3C2Tx MXene Nanosheets for Promoting Structure-Functional Skeletal Muscle Regeneration via Electroactivity and Microenvironment Management

The completed volumetric muscle loss (VML) regeneration remains a challenge due to the limited myogenic differentiation as well as the oxidative, inflammatory, and hypoxic microenvironment. Herein, a 2D Ti3C2Tx MXene@MnO2 nanocomposite with conductivity and microenvironment remodeling was fabricated and applied in developing a multifunctional hydrogel (FME) scaffold to simultaneously conquer these hurdles. Among them, Ti3C2Tx MXene with electroconductive ability remarkably promotes myogenic differentiation via enhancing the myotube formation and upregulating the relative expression of the myosin heavy chain (MHC) protein and myogenic genes (MyoD and MyoG) in myogenesis. The MnO2 nanoenzyme-reinforced Ti3C2Tx MXene significantly reshapes the hostile microenvironment by eliminating reactive oxygen species (ROS), regulating macrophage polarization from M1 to M2 and continuously supplying O2. Together, the FME hydrogel as a bioactive multifunctional scaffold significantly accelerates structure-functional VML regeneration in vivo and represents a multipronged strategy for the VML regeneration via electroactivity and microenvironment management.

miR-145a-5p/Plexin-A2 promotes the migration of OECs and transplantation of miR-145a-5p engineered OECs promotes the functional recovery in rats with SCI

BACKGROUND

Olfactory ensheathing cells (OECs) serve as a bridge by migrating at the site of spinal cord injury (SCI) to facilitate the repair of the neural structure and neural function. However, OEC migration at the injury site not only faces the complex and disordered internal environment but also is closely associated with the migration ability of OECs.

METHODS

We extracted OECs from the olfactory bulb of SD rats aged <7 days old. We verified the micro ribonucleic acid (miR)-145a-5p expression level in the gene chip after SCI and OEC transplantation using quantitative reverse transcription (qRT)-polymerase chain reaction (PCR). The possible target gene Plexin-A2 of miR-145a-5p was screened using bioinformatics and was verified using dual-luciferase reporter assay, Western blot, and qRT-PCR. The effect of miR-145a-5p/plexin-A2 on OEC migration ability was verified by wound healing assay, Transwell cell migration assay, and immunohistochemistry. Nerve regeneration was observed at the injured site of the spinal cord after OEC transplantation using tissue immunofluorescence and magnetic resonance imaging, diffusion tensor imaging, and the Basso-Beattie-Bresnahan locomotor rating scale were further used for imaging and functional evaluation.

RESULTS

miR-145a-5p expression in the injured spinal cord tissue after SCI considerably decreased, while Plexin-A2 expression significantly increased. OEC transplantation can reverse miR-145a-5p and Plexin-A2 expression after SCI. miR-145a-5p overexpression enhanced the intrinsic migration ability of OECs. As a target gene of miR-145a-5p, Plexin-A2 hinders OEC migration. OEC transplantation overexpressing miR-145a-5p after SCI can increase miR-145a-5p levels in the spinal cord, reduce Plexin-A2 expression in the OECs and the spinal cord tissue, and promote OEC migration and distribution at the injured site. OEC transplantation overexpressing miR-145a-5p can promote the regeneration and repair of neural morphology and neural function.

CONCLUSIONS

Our study demonstrated that miR-145a-5p could promote OEC migration to the injured spinal cord after cell transplantation by down-regulating the target gene Plexin-A2, thereby repairing the neural structure and function after SCI in rats.

Green polymer hydrogels from a natural monomer with inherent antioxidative capability for efficient wound healing and spinal cord injury treatment

Development of polymeric hydrogels with multiple functions (adhesiveness, self-healability, anti-oxidation efficiency, etc.) through one-step green polymerization of naturally occurring small molecules in water is critical for various biomedical applications and clinical transformation. In this work, benefiting from the dynamic disulfide bond in α-lipoic acid (LA), we directly obtain an advanced hydrogel (poly(lipoic acid-co-sodium lipoate) (PLAS)) through heat and concentration-induced ring-opening polymerization of LA with the addition of NaHCO₃ in an aqueous solution. The presence of COOH, COO^- and disulfide bonds endows the resulting hydrogels with comprehensive mechanical properties, facile injectability, fast self-healability and adequate adhesiveness. Moreover, the PLAS hydrogels show promising antioxidative efficiency, inherited from naturally occurring LA, and can efficiently eliminate intracellular reactive oxygen species (ROS). We also verify the advantage of PLAS hydrogels in a rat spinal injury model. Through the regulation of ROS and in situ inflammation, our system can promote the recovery of spinal cord injury. Owing to the natural origin and inherent anti-oxidative capability of LA, and a green preparation method, our hydrogel should be beneficial for clinical transformation and may be a good candidate for various biomedical applications.

ZIM3 activation of CCL25 expression in pulmonary metastatic nodules of osteosarcoma recruits M2 macrophages to promote metastatic growth

Tumor-associated macrophages (TAMs) play an important role in tumor growth and metastasis. However, the involvement of TAMs infiltration in pulmonary osteosarcoma (OS) metastasis remains poorly understood. Therefore, the effect of OS cells on macrophages migration was investigated by in vivo and in vitro experiments to evaluate the infiltration and mechanism of TAMs in pulmonary OS metastases. The results showed that the zinc finger protein ZIM3 was upregulated in OS cells than in osteoblasts and activated the expression of CCL25, which subsequently promoted the migration of M2 macrophages. CCL25 or ZIM3 silencing in OS cells inhibited the infiltration of M2 macrophages and the formation of pulmonary metastatic nodules in a mouse model of pulmonary OS metastasis and prolonged the survival of the mice. Furthermore, bioinformatics analyses revealed that CCL25 and ZIM3 expressions are negatively correlated with the prognosis of OS patients. In conclusion, this study found that a large number of M2 TAMs were recruited into pulmonary metastatic nodules of OS through the activation of the ZIM3-CCL25 axis in OS cells, thereby facilitating OS metastasis. Therefore, the suppression of ZIM3-CCL25-induced recruitment of M2 TAMs to the metastatic sites might be considered as a therapeutic approach to inhibit the growth of pulmonary OS metastases.

Roles of irregularity of pore morphology in osteogenesis of Voronoi scaffolds: From the perspectives of MSC adhesion and mechano-regulated osteoblast differentiation

Bone scaffolds designed based on the Voronoi-tessellation algorithm have been increasingly studied owing to their structural similarity with natural cancellous bone. The irregularity of pore morphology (IPM) influences the osteogenesis efficiency of Voronoi scaffolds since it may alter the static and hydromechanical microenvironments for the initial adhesion and mechano-regulated osteoblast differentiation (MrOD) of mesenchymal stem cells (MSCs). In this work, animal experiments were conducted to explore the relationship between IPM and osteogenesis efficiency in Voronoi scaffolds. A computational fluid dynamics (CFD) analysis based on discrete phase models was performed to predict the efficiency of MSC adhesion in different IPMs. Another combined finite element and CFD analysis based on the mechano-regulation algorithm was performed to predict the influence of IPM on the MrOD of the adhesive MSCs. The results showed that the osteogenesis efficiency of the Voronoi scaffolds increased as the IPM rose from low to moderate and then dropped as the IPM further rose. Same trends were also found in the MSC adhesion and MrOD, which caused by the changes of strain tensors on the strut surface and the tortuosity and fluid velocity of the fluid pathway. Moderate IPM induced the highest osteogenesis efficiency owing to its highest efficiencies of MSC adhesion and MrOD. This work identified the optimal IPM for the osteogenesis of Voronoi scaffolds and clarified its biomechanical mechanisms from the adhesion and mechano-regulated differentiation of MSCs, which is of great importance for guiding Voronoi scaffold design when it is used for bone defect repair.

Biocompatibility and osteointegration capability of β-TCP manufactured by stereolithography 3D printing: In vitro study

Beta-tricalcium phosphate (β-TCP) bioceramics have an inorganic composition similar to the human bone. While conventional methods can only produce ceramic scaffolds with poor controllability, the advancement of 3D-printing, especially stereolithography, made it possible to manufacture controllable, highly precise, micropore ceramic scaffolds. In this study, the stereolithography was applied to produce β-TCP bioceramics, while ZrO₂, Al₂O₃, Ti6Al4V, and polyetheretherketone (PEEK) were used as controls. Phase analysis, water contact angle tests, and Micro-CT were applied to evaluate the surface properties and scaffold. Hemolytic toxicity, cell proliferation, and morphological assessment were performed to evaluate the biocompatibility. Alkaline phosphatase (ALP) level, mineralization, and qRT-PCR were measured to evaluate the osteointegration. During the manufacturing of β-TCP, no evident impurity substance and hemolytic toxicity was found. Cells on β-TCP had good morphologies, and their proliferation capability was similar to Ti6Al4V, which was higher than the other materials. Cells on β-TCP had higher ALP levels than PEEK. The degree of mineralization was significantly higher on β-TCP. The expression of osteogenesis-related genes on β-TCP was similar to Ti6Al4V and higher than the other materials. In this study, the β-TCP produced by stereolithography had no toxicity, high accuracy, and excellent osteointegration capability, thus resulting as a good choice for bone implants.

Analysis of surgical strategies and efficacy in the treatment of Os odontoideum with atlantoaxial dislocation

BACKGROUND

There are many classification systems for atlantoaxial dislocation (AAD). Among these systems, the definitions of irreducible AAD remain vague, and its treatments are not unified.

OBJECTIVE

To explore the surgical strategies and efficacy for the treatment of os odontoideum (OO) with AAD.

METHODS

The clinical data of 56 OO patients with AAD who underwent surgery from January 2017 to June 2021 were retrospectively analyzed. AAD was classified into four types, Type I and type II were treated with posterior fixation and fusion. Type III received posterior fixation and fusion after irreducible dislocations were converted to reducible dislocations by translateral mass release or transoral release. Type IV required transoral release for conversion into reducible dislocations before posterior fixation and fusion. The operation time, blood loss, and complications were recorded. The preoperative and postoperative neurological function changes were assessed using the Japanese Orthopedic Association (JOA) score. Postoperative fusion status was assessed by X-ray.

RESULTS

There were 40 cases of type I-II, 14 cases of type III, and two cases of type IV AAD. The operation times of single posterior fixation and fusion, combined translateral mass release and combined transoral release were 130.52 ± 37.12 min, 151.11 ± 16.91 min and 188.57 ± 44.13 min, the blood loss were 162.63 ± 58.27 mL, 235.56 ± 59.94 mL, 414.29 ± 33.91 mL, respectively. One patient with type III died, one with type III underwent revision surgery due to infection, and three patients with type I had further neurological deterioration after operation. fifty-five patients were followed up for 12-24 months. The follow-up results showed that enough decompression was achieved and that fixation and fusion were effective. The JOA score increased from 9.58 ± 1.84 points preoperative to 13.09 ± 2.68 points at 3 months after operation, 14.07 ± 2.83 points at 6 months and 14.25 ± 2.34 at 12 months after operation, all significant differences compared with preoperative results (P < 0.05).

CONCLUSION

OO patients with irreducible AAD can be treated by translateral mass release or transoral release combined with posterior fixation and fusion, while some of those with bony fusion can be treated by transoral release combined with posterior fixation and fusion.

Computational comparison of anterior lumbar interbody fusion and oblique lumbar interbody fusion with various supplementary fixation systems: a finite element analysis

BACKGROUND AND OBJECTIVE

Anterior lumbar interbody fusion (ALIF) and oblique lumbar interbody fusion (OLIF) have shown a great surgical potential, while it has always been controversial which surgical approach and which type of fixation system should be selected. This study investigated the biomechanical response of ALIF and OLIF with various supplementary fixation systems using the finite element method.

MATERIALS AND METHODS

Lumbar L4-L5 ALIF and OLIF models stabilized by different supplementary fixation systems (stand-alone cage, integrated stand-alone cage, anterior plate, and bilateral pedicle screw) were developed to assess the segmental range of motion (ROM), endplate stress (EPS), and screw-bone interface stress (SBIS).

EXPERIMENTAL RESULTS

ALIF showed lower ROM and EPS than OLIF in all motion planes and less SBIS in the most of motion planes compared with OLIF when the anterior plate or pedicle screw was used. ALIF induced higher ROM, while lower EPS and SBIS than OLIF in the majority of motion planes when integrated stand-alone cage was utilized. Using a stand-alone cage in ALIF and OLIF led to cage migration. Integrated stand-alone cage prevented the cage migration, whereas caused significantly larger ROM, EPS, and SBIS than other fixation systems except for the rotation plane. In the most of motion planes, the pedicle screw had the lowest ROM, EPS, and SBIS. The anterior plate induced a slightly larger ROM, EPS, and SBIS than the pedicle screw, while the differences were not significant.

CONCLUSION

ALIF exhibited a better performance in postoperative segmental stability, endplate stress, and screw-bone interface stress than OLIF when the anterior plate or the pedicle screw was used. The pedicle screw could provide the greatest postoperative segmental stability, less cage subsidence incidence, and lower risk of fixation system loosening in ALIF and OLIF. The anterior plate could also contribute to the stability required and fewer complications, while not as effectively as the pedicle screw. Extreme caution should be regarded when the stand-alone cage is used due to the risk of cage migration. The integrated stand-alone cage may be an alternative method; however, further optimization is needed to reduce complications and improve postoperative segmental stability.

MicroRNA-137-mediated lysine demethylase 4A regulates the recovery of spinal cord injury via the SFRP4-Wnt/β-Catenin axis

OBJECTIVE

Spinal cord injury (SCI) causes great harm to the normal life of patients. Histone demethylase is involved in many biological processes, including SCI. Hence, this study explored the role and mechanism of histone lysine demethylase 4A (KDM4A) in SCI.

METHODS

The acute SCI (ASCI) rat model was established after spinal compression and the SCI neuronal model was induced via treating PC12 cells with lipopolysaccharide (LPS). KDM4A expression during SCI was detected. The microRNA (miRNA) targeting KDM4A was predicted and verified. The miRNA and KDM4A expression patterns were intervened in LPS-stimulated PC12 cells to evaluate their combined effects on neuronal cells in SCI. The downstream pathways of KDM4A were predicted, and SFRP4 and H3K9me3 expressions were determined. After the intervention of SFRP4 in LPS-treated cells, β-Catenin expression and the effect of SFRP4 on neuronal cells in SCI were detected. Finally, the effectiveness of the miR-137/KDM4A/SFRP4/Wnt/β-Catenin axis was verified in vivo.

RESULTS

KDM4A was abnormally elevated in SCI. miR-137 targeted KDM4A. miR-137 effectively inhibited the apoptosis of LPS-challenged PC12 cells, which could be reversed after overexpressing KDM4A. KDM4A promoted SFRP4 expression through demethylation of H3K9me3. Overexpression of SFRP4 blocked the Wnt/β-Catenin pathway and promoted apoptosis of LPS-stimulated cells. In vivo, miR-137 overexpression remarkably improved SCI symptoms, accompanied by obviously increased β-Catenin expression and notably decreased KDM4A and SFRP4 expressions, while overexpressed KDM4A treatment showed the opposite trend in the presence of miR-137.

CONCLUSION

We demonstrated that miR-137 targeted KDM4A and then downregulated SFRP4 to ameliorate SCI in a Wnt/β-Catenin-dependent manner.

Transcriptional Circuitry of NKX2-1 and SOX1 Defines an Unrecognized Lineage Subtype of Small-Cell Lung Cancer

Rationale: The current molecular classification of small-cell lung cancer (SCLC) on the basis of the expression of four lineage transcription factors still leaves its major subtype SCLC-A as a heterogeneous group, necessitating more precise characterization of lineage subclasses. Objectives: To refine the current SCLC classification with epigenomic profiles and to identify features of the redefined SCLC subtypes. Methods: We performed unsupervised clustering of epigenomic profiles on 25 SCLC cell lines. Functional significance of NKX2-1 (NK2 homeobox 1) was evaluated by cell growth, apoptosis, and xenograft using clustered regularly interspaced short palindromic repeats-Cas9 (CRISPR-associated protein 9)-mediated deletion. NKX2-1-specific cistromic profiles were determined using chromatin immunoprecipitation followed by sequencing, and its functional transcriptional partners were determined using coimmunoprecipitation followed by mass spectrometry. Rb1flox/flox; Trp53flox/flox and Rb1flox/flox; Trp53flox/flox; Nkx2-1flox/flox mouse models were engineered to explore the function of Nkx2-1 in SCLC tumorigenesis. Epigenomic landscapes of six human SCLC specimens and 20 tumors from two mouse models were characterized. Measurements and Main Results: We identified two epigenomic subclusters of the major SCLC-A subtype: SCLC-Aα and SCLC-Aσ. SCLC-Aα was characterized by the presence of a super-enhancer at the NKX2-1 locus, which was observed in human SCLC specimens and a murine SCLC model. We found that NKX2-1, a dual lung and neural lineage factor, is uniquely relevant in SCLC-Aα. In addition, we found that maintenance of this neural identity in SCLC-Aα is mediated by collaborative transcriptional activity with another neuronal transcriptional factor, SOX1 (SRY-box transcription factor 1). Conclusions: We comprehensively describe additional epigenomic heterogeneity of the major SCLC-A subtype and define the SCLC-Aα subtype by the core regulatory circuitry of NKX2-1 and SOX1 super-enhancers and their functional collaborations to maintain neuronal linage state.

Macrophage Extracellular Traps Exacerbate Secondary Spinal Cord Injury by Modulating Macrophage/Microglia Polarization via LL37/P2X7R/NF-κB Signaling Pathway

Persistent inflammation in the secondary spinal cord injury (SCI) is an important reason for the failure of nerve repair, which is partly due to the continuous activation of local M1-like macrophage/microglia. It is reported that extracellular trap (ET) has been a new way of cell death, which can be released by macrophages and named macrophage extracellular trap (Met). Furthermore, it exists widely in the pathophysiological process of many diseases, but it has been rarely studied in the field of SCI. In this study, we constructed a spinal cord contusion model and assessed the function outcome of SCI rats. We used immunofluorescence, flow cytometry, and transmission electron microscope (TEM) to demonstrate the existence of Mets. Besides, some related experiments had also been employed to explore the relationship between Mets and M1 polarization of macrophage/microglia. We also performed Co-IP and Western blotting to reveal a new extracellular proinflammatory signal pathway. Finally, we made a linear regression analysis between the concentrations of specific markers of Mets in human serum and ASIA scores. Briefly, our results suggested that macrophages infiltrated in SCI area could induce macrophage/microglia to differentiate into M1-like cells by releasing Mets, which may be achieved partly through LL37-P2X37-NF-κB signal pathway. However, limiting Mets could effectively inhibit M1 polarization and promote function recovery. In addition, the concentrations of Met related proteins in human serum showed high correlation with ASIA scores and could be applied to reflect the severity of SCI. In conclusion, Mets may be a new target for SCI therapy and a promising index for SCI assessment.

Biomechanics of a novel artificial cervical vertebra from an in vivo caprine cervical spine non-fusion model

Objective

Anterior cervical corpectomy and fusion (ACCF) has been widely used in the treatment of cervical spondylotic myelopathy (CSM) but is accompanied by unavoidable motion loss and destruction of vertebra. We aim to evaluate the range of motion (ROM) of caprine cervical spine constructs implanted with cervical artificial disc and vertebra system (ADVS). The purpose of this study was to investigate the biomechanical properties of the ADVS from an in vivo caprine cervical spine non-fusion model.

Methods

Twelve goats were randomly divided into ADVS or control group, with 6 animals in each group. The animals in the ADVS group were implanted with ADVS at the C₄ level. The cervical spine constructs were harvested 6 months after the operation. The ROM of cervical spine specimens in the ADVS group was recorded. Biomechanical testing of the specimens in the control group were conducted to evaluate the ROM of the cervical spine specimens under intact and fixed condition (C₃-C₅) by an anterior plate, respectively.

Results

The biomechanical outcomes showed that the ROM of the levels (C₃-C₅) implanted with ADVS was maintained. The ROM in the adjacent level (C_2-3) did not increase significantly comparing with intact group.

Conclusions

In general, ADVS could preserve the ROM of operative levels and could reconstruct the height of the vertebra. ADVS did not increase the ROM of upper adjacent level. This device provides a non-fusion method for the treatment of patients suffering from CSM. However, improvements on the design of ADVS are still needed.

Translational potential statement

This study introduced a novel cervical spinal implant, which was designed to have the ability of motion preservation and vertebra construction. Our study provided a non-fusion procedure in the treatment of CSM after ACCF.

Spinal dural arteriovenous fistula: A rare but treatable disease that should not be missed by orthopedic surgeons

Objective

Spinal dural arteriovenous fistula (SDAVF) is a rare disease that is often misdiagnosed by orthopedic surgeons. We analyzed the reasons for the misdiagnosis and proposed countermeasures.

Methods

Twenty-two SDAVF patients who were initially treated in orthopedics were included. The patients were divided into a correct diagnosis group (A) and a misdiagnosis group (B). The clinical data and prognosis were evaluated.

Results

There were 10 patients in group A and 12 patients in group B. The clinical manifestations included limb numbness, weakness, and bladder and bowel dysfunction. Among these patients without spinal degenerative diseases which had typical magnetic resonance imaging (MRI) features in Group A were more than Group B (P < 0.05). More patients had spinal degenerative diseases in group B. In group A, seven patients were primarily diagnosed with a SDAVF after multidisciplinary teamwork (MDT). In group B, five patients were misdiagnosed with lumbar spinal stenosis, four with lumbar disc herniation, two with thoracic spinal stenosis, and one with cervical spinal stenosis and lumbar spinal stenosis and underwent cervical spinal canal and lumbar spinal canal decompression. The length of time for confirming the diagnosis was 7 months longer in group B than in group A. All patients underwent microsurgery treatment. The average follow-up duration was 11 months. The modified Aminoff-Logue Disability Scale scores showed a statistically significant difference in improvement between the two groups (P < 0.05).

Conclusion

when patients with dysuria especially, have intermittent spinal nerve dysfunction, the possibility of SDAVF should be considered. Awareness of the specific clinical and spinal cord edema and flow voids on MRI of a SDAVF needs to be promoted for orthopedic surgeons. Timely MDT is an important measure for reducing misdiagnosis, and steroids or inappropriate surgery should be avoided until a SDAVF is completely excluded.

The application of biomaterials in osteogenesis: A bibliometric and visualized analysis

Osteogenesis serves an important role in bone tissue repairing. Novel biomaterials are widely prevalent as materials for orthopedic implants due to their biocompatibility and osteogenetic ability. The purpose of this study was to comprehensively analyze hotspots and future trend of biomaterials research in osteogenesis based on bibliometric and visualized analysis. A total of 1,523 papers about biomaterials research in osteogenesis between 2000 and 2021 were included in this study. During the above 20 years, China’s leading position in the global biomaterials research in osteogenesis was obvious, and it was also the country that most frequently participates in international cooperation. Chinese Academy of Sciences was the most productive institution and the leader of research cooperation. Acta Biomaterialia and Biomaterials have published the largest number of articles in the field of biomaterials research in osteogenesis. Meanwhile, Acta Biomaterialia and Biomaterials were also the two journals with the highest total citation frequency. Wu CT, Chang J, Kaplan DL, and Xiao Y all made important contributions in the field of biomaterials research in osteogenesis. At present, there are five research hotspots in the field of biomaterials research in osteogenesis: 1) the immunomodulatory role of biomaterial-related inflammatory; 2) mechanisms of osteogenesis in biomaterials; 3) 3D printing and clinical application of biomaterials; 4) bone tissue engineering for biomaterial osteogenesis; and 5) regenerative medicine for biomaterial osteogenesis. The results of this study showed that mechanisms of osteogenesis in biomaterials, bone tissue engineering for biomaterial osteogenesis, and regenerative medicine for biomaterial osteogenesis will remain research hotspots in the future. International cooperation was also expected to expand and deepen the field of biomaterials research in osteogenesis.

Prophylactic Use of Antibiotics for Fever After Drainage Removal Following a Dural Tear During Lumbar Spinal Surgery: A Retrospective Study

Background

Dural tear and subsequent cerebrospinal fluid leakage are frequent complications during lumbar spine surgery. This retrospective study aimed to investigate the risk factors and the use of prophylactic antibiotics in patients with fever after drainage removal (FDR) following lumbar dural tear during lumbar spinal surgery.

Material/Methods

The authors retrospectively analyzed 2812 patients who underwent different spinal surgical procedures from January 2015 to December 2017. The basic information of patients was obtained to analyze the risk factors of dural tear and FDR. The patients were divided into 5 groups according to their antibiotic strategies for FDR (no antibiotics, ceftriaxone, vancomycin, ceftriaxone+vancomycin, other antibiotics). Body temperature, laboratory test results, and pathogen profiles were collected for analysis.

Results

There were 326 cases diagnosed as dural tear, including 198 cases of FDR. Sex, age, type of disease, and previous lumbar surgery played significant roles in the dural tear rate (P<0.05). Patients older than 60 years old had a higher incidence of FDR after dural tear (P<0.05). There was no significant difference in the incidence of surgical site infection among the various treatment groups (P>0.05).

Conclusions

Age has obvious effect on dural tear and FDR, whereas sex, revision surgery, primary diagnosis, and procedure type only affect the rate of dural tear. The prophylactic use of antibiotics has no effect on the incidence of surgical site infection when fever after drainage removal occurred in patients with dural tear.

Identification of a circRNA-mediated comprehensive ceRNA network in spinal cord injury pathogenesis

RNAs are closely associated with human diseases; however, immune-related genes (IRGs) and their potential regulatory networks in relation to spinal cord injury (SCI) are still poorly understood. Here, we investigated the key IRGs as well as the competing endogenous RNA (ceRNA) mechanisms that are associated with SCI pathogenesis based on microarray datasets and the use of a rat SCI model. Specifically, four independent SCI microarray datasets from Gene Expression Omnibus (GEO) database were analyzed and, thereafter, differentially expressed IRGs were annotated via Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Furthermore, based on the GEO datasets, differentially expressed RNAs (DERNAs), including DEcircRNAs, DEmiRNAs, and DEmRNAs were identified and interactions between them were also predicted using online databases, and to construct a circular RNA (circRNA) mediated ceRNA network, candidate RNAs were also identified. Furthermore, the support vector machine (SVM) and least absolute shrinkage and selection operator (LASSO) methods were used for the identification of critical DERNAs, while differential gene expression was validated using the GSE20907 dataset. Our results were as follows. In the SCI microarray datasets, 32, 58, and 74 DEIRGs, DEcircRNAs, and DEmiRNAs were identified, respectively. In addition, GO and KEGG analyses showed that the DEIRGs were primarily enriched in neutrophil-mediated immunity and nuclear factor-kappa B (NF-κB) and hypoxia-inducible factor-1 (HIF-1) signaling pathways, and based on LASSO and SVM screening, PLXNB2 was identified as a DEIRG, while hsa_circ_0026646 was identified as the key circRNA, showing a higher SCI expression. Furthermore, our results proved that PLXNB2 and hsa_circ_0026646 were upregulated in SCI, whereas miR-331-3p was downregulated, and, interestingly, similar expression profiles were confirmed using the rat SCI model. Furthermore, fluorescent reporter assay indicated that both hsa_circ_0026646 and PLXNB2 have miR-331-3p target sites, and the ceRNA hypothesis suggested the dysregulation of hsa_circ_0026646, miR-331-3p, and PLXNB2 in SCI. Thus, our results suggested that in SCI pathogenesis, hsa_circ_0026646 correlates with PLXNB2 by targeting miR-331-3p.

Mycobacterium tuberculosis Induced Osteoblast Dysregulation Involved in Bone Destruction in Spinal Tuberculosis

Disturbance of bone homeostasis caused by Mycobacterium tuberculosis (Mtb) is a key clinical manifestation in spinal tuberculosis (TB). However, the complete mechanism of this process has not been established, and an effective treatment target does not exist. Increasing evidence shows that abnormal osteoclastogenesis triggered by an imbalance of the receptor activator of NF-κB ligand (RANKL)/osteoprotegerin (OPG) axis may play a key role in the disturbance of bone homeostasis. Previous studies reported that RANKL is strongly activated in patients with spinal TB; however, the OPG levels in these patients were not investigated in previous studies. In this study, we investigated the OPG levels in patients with spinal TB and the dysregulation of osteoblasts caused by Mtb infection. Inhibition of the Mce4a gene of Mtb by an antisense locked nucleic acid (LNA) gapmer (Mce4a-ASO) was also investigated. Analysis of the serum OPG levels in clinical samples showed that the OPG levels were significantly decreased in patients with spinal TB compared to those in the group of non-TB patients. The internalization of Mtb in osteoblasts, the known major source of OPG, was investigated using the green fluorescent protein (GFP)-labeled Mycobacterium strain H37Ra (H37RaGFP). The cell-associated fluorescence measurements showed that Mtb can efficiently enter osteoblast cells. In addition, Mtb infection caused a dose-dependent increase of the CD40 mRNA expression and cytokine (interleukin 6, IL-6) secretion in osteoblast cells. Ligation of CD40 by soluble CD154 reversed the increased secretion of IL-6. This means that the induced CD40 is functional. Considering that the interaction between CD154-expressing T lymphocytes and bone-forming osteoblast cells plays a pivotal role in bone homeostasis, the CD40 molecule might be a strong candidate for mediating the target for treatment of bone destruction in spinal TB. Additionally, we also found that Mce4a-ASO could dose-dependently inhibit the Mce4a gene of Mtb and reverse the decreased secretion of IL-6 and the impaired secretion of OPG caused by Mtb infection of osteoblast cells. Taken together, the current finding provides breakthrough ideas for the development of therapeutic agents for spinal TB.

Extracellular vesicle-derived miR-511-3p from hypoxia preconditioned adipose mesenchymal stem cells ameliorates spinal cord injury through the TRAF6/S1P axis

Extracellular vesicle (EV) from hypoxic adipose tissue-derived mesenchymal stem cells (AD-MSCs) play critical roles in spinal cord injury (SCI) by transferring miRNAs to target cells through fusion with the cell membrane. However, the role of miR-511-3p within the AD-MSCs -derived EV in SCI is largely unknown. Western blotting results demonstrated the secretion of EVs derived from AD-MSCs under hypoxia (Hyp-EVs) was more than those under normoxia (Nor-EVs), and miR-511-3p expression was more enriched in Hyp-EVs. PC12 cells were stimulated with lipopolysaccharide (LPS) to induce cell damage. AD-MSCs were transfected with miR-511-3p mimic or miR-511-3p inhibitor to induce EVs-miR-511-3p overexpression or silencing. Cells treated with Hyp-EVs-miR-511-3p mimic reduced LPS-induced apoptosis, alleviated inflammation and promoted proliferation, while cells treated with Hyp-EVs-miR-511-3p inhibitor aggravated LPS-induced apoptosis and inflammation, and suppressed proliferation. Luciferase reporter gene assay revealed tumor necrosis factor receptor-associated factor 6 (TRAF6) was a target downstream gene of miR-511-3p. A series of gain- and loss-of-function experiments verified that TRAF6 could antagonize the effects of Hyp-EVs-miR-511-3p on inflammation, cell apoptosis and viability. Furthermore, cells treated with CYM5541, an agonist of sphingosine-1-phosphate receptor 3 (S1PR3), reversed the inhibitory effect of Hyp-EVs-miR-511-3p mimic on S1PR3 expression, inflammation and cell apoptosis. Finally, intravenously injection of Hyp-EVs-miR-511-3p mimic into SCI model rats obviously reduced inflammation and promoted neurological function recovery. In conclusion, EVs-derived miR-511-3p from hypoxia preconditioned AD-MSCs ameliorates SCI via TRAF6/S1P/NF-κB pathway, which indicates that miR-511-3p may be a potential therapeutic target for SCI.

Cervical non-fusion using biomimetic artificial disc and vertebra complex: technical innovation and biomechanics analysis

Background

Changes in spinal mobility after vertebral fusion are important factors contributing to adjacent vertebral disease (ASD). As an implant for spinal non-fusion, the motion-preserving prosthesis is an effective method to reduce the incidence of ASD, but its deficiencies hamper the application in clinical. This study designs a novel motion-preserving artificial cervical disc and vertebra complex with an anti-dislocation mechanism (MACDVC-AM) and verifies its effect on the cervical spine.

Methods

The MACDVC-AM was designed on the data of healthy volunteers. The finite element intact model, fusion model, and MACDVC-AM model were constructed, and the range of motion (ROM) and stress of adjacent discs were compared. The biomechanical tests were performed on fifteen cervical specimens, and the stability index ROM (SI-ROM) were calculated.

Results

Compared with the intervertebral ROMs of the intact model, the MACDVC-AM model reduced by 28–70% in adjacent segments and increased by 26–54% in operated segments, but the fusion model showed the opposite result. In contrast to the fusion model, the MACDVC-AM model diminished the stress of adjacent intervertebral discs. In biomechanical tests, the MACDVC-AM group showed no significant difference with the ROMs of the intact group (p > 0.05). The SI-ROM of the MACDVC-AM group is negative but close to zero and showed no significant difference with the intact group (p > 0.05).

Conclusions

The MACDVC-AM was successfully designed. The results indicate that the MACDVC-AM can provide physiological mobility and stability, reduce adjacent intervertebral compensatory motion, and alleviate the stress change of adjacent discs, which contributes to protect adjacent discs and reduce the occurrence of ASD.

Relationship between the elastic modulus of the cage material and the biomechanical properties of transforaminal lumbar interbody fusion: A logarithmic regression analysis based on parametric finite element simulations

BACKGROUND AND OBJECTIVE

Conventional method for evaluating the biomechanical effects of a specific elastic modulus of cage (cage-E) on spinal fusions requires establishing a "one-on-one" biomechanical model, which seems laborious and inefficient when dealing with the emergence of numerous cage materials with various cage-Es. We aim to offer a much convenient method to instantly predicting the biomechanical effects of any targeted cage-E on transforaminal lumbar interbody fusion (TLIF) by using a parametric finite element (FE) analysis to determining the regression relationship between cage-E and biomechanical properties of TLIF.

MATERIALS AND METHODS

A L4/5 FE TLIF construct was modeled. Cage-E was linearly increased from 0.1 GPa (cancellous bone) to 110 GPa (titanium alloy). The function equations for assessing the influence of cage-E on the biomechanical indexes of TLIF were established using a logarithmic regression analysis.

EXPERIMENTAL RESULTS

As cage-E increased from 0.1 GPa to 110 GPa, all the biomechanical indexes initially increased or decayed rapidly, and then slowed over time. Logarithmic regression models and functional equations were successfully established between cage-E and these indexes (P<0.0001). Their determination coefficients ranged from 0.72 to 0.99. The range of motions decreased from 0.37-1.10° to 0.20-1.07°. The mean stresses of the central and peripheral grafts reduced from 0.10-0.41 and 0.25-0.42 MPa to 0.03-0.04 and 0.19-0.27 MPa, respectively. In addition, the maximum stresses of the screw-bone interface and posterior instrumentation reduced from 11.76-25.04 and 8.91-84.68 MPa to 9.71-18.92 and 6.99-70.59 MPa, respectively. Finally, the maximum stresses of the cage and endplate increased from 0.28-1.35 MPa and 3.90-8.63 MPa to 14.86-36.16 MPa and 11.01-36.55 MPa, respectively.

CONCLUSIONS

The decrease of cage-E reduces the risks of cage subsidence, cage breakage, and pseudarthrosis, while increasing the risk of instrumentation failure. The logarithmic regression models optimally demonstrate the relationship between cage-E and biomechanical properties of TLIF. The functional equations based on these models can be adopted to predict the biomechanical effects of any targeted cage-Es on TLIF, which effectively simplifies the procedures for the biomechanical assessments of cage materials.

Macrophages facilitate peripheral nerve regeneration by organizing regeneration tracks through Plexin-B2

In this study, Li et al. investigated the mechanisms underlying the regeneration of peripheral nerves, which is guided by regeneration tracks formed through an interplay of many cell types. They demonstrate that macrophages are mobilized ahead of Schwann cells in the nerve bridge after transection injury to participate in building regeneration tracks. This requires the function of guidance receptor Plexin-B2, which is robustly up-regulated in infiltrating macrophages in injured nerve.

The regeneration of peripheral nerves is guided by regeneration tracks formed through an interplay of many cell types, but the underlying signaling pathways remain unclear. Here, we demonstrate that macrophages are mobilized ahead of Schwann cells in the nerve bridge after transection injury to participate in building regeneration tracks. This requires the function of guidance receptor Plexin-B2, which is robustly up-regulated in infiltrating macrophages in injured nerves. Conditional deletion of Plexin-B2 in myeloid lineage resulted in not only macrophage misalignment but also matrix disarray and Schwann cell disorganization, leading to misguided axons and delayed functional recovery. Plexin-B2 is not required for macrophage recruitment or activation but enables macrophages to steer clear of colliding axons, in particular the growth cones at the tip of regenerating axons, leading to parallel alignment postcollision. Together, our studies unveil a novel reparative function of macrophages and the importance of Plexin-B2-mediated collision-dependent contact avoidance between macrophages and regenerating axons in forming regeneration tracks during peripheral nerve regeneration.

Traditional Chinese medicine together with high-dose vitamin C improves the therapeutic effect of western medicine against COVID-19

OBJECTIVES

Traditional Chinese medicine has been reported to be effective in the treatment of epidemic diseases. Here, we aimed to investigate the effects of combined therapy of Chinese and western medicine on coronavirus disease 2019 (COVID-19).

METHODS

A total of 60 patients diagnosed with COVID-19 were enrolled. Both the ordinary and severely affected patients were randomly divided into Groups A-C each with 10 cases each. The patients in Group A-C received Western medicine, Western medicine + traditional Chinese medicine, and Western medicine + traditional Chinese medicine + high dose of vitamin C, respectively. The time of disease recovery, symptoms disappearance, chest CT improvement, and tongue amelioration was recorded. Leukocyte, neutrophil and lymphocyte were monitored, as well as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), procalitonin (PCT), inflammatory factors, partial pressure of oxygen and carbon dioxide (PaCO₂) and oxygenation index (PaO₂). Urinary tract stones, liver function, and other side-effects such as gastrointestinal dysfunction were also investigated.

RESULTS

Traditional Chinese medicine enhanced the effect of Western medicine, including the reduction of CRP, ESR, PCT, and inflammatory factors, and the increase of leukocyte, neutrophil, and lymphocyte counts, and the improvement of respiratory rate, PaO₂, PaCO₂, and oxygenation index. Traditional Chinese medicine combined with high-dose Vitamin C therapy more effectively shortened the time of disease recovery, symptom disappearance, chest CT improvement, and tongue amelioration.

CONCLUSIONS

a combined therapy of Western medicine, traditional Chinese medicine, and high dose of Vitamin C results in a most effective outcome in the treatment of COVID-19.

[Clinicopathological characteristics of SMARCB1(INI1)-deficient sinonasal carcinoma]

Objective: To investigate the clinicopathological characteristics, diagnosis, differential diagnosis and prognostic factors of SMARCB1 (INI1)-deficient sinonasal carcinoma (SDSC). Methods: Sixteen cases of SDSC diagnosed in the Department of Pathology, Beijing Tongren Hospital from January 2016 to September 2020 were enrolled. Ninety-nine cases of small round cell malignant tumors of the head and neck were selected as the control, including poorly-differentiated squamous cell carcinoma (n=10), poorly-differentiated adenocarcinoma (n=5), undifferentiated carcinoma (SNUC, n=4), NUT carcinoma (n=5), neuroendocrine carcinoma (n=10), and other non-epithelial tumors [olfactory neuroblastoma (n=10), rhabdomyosarcoma (n=10), NK/T-cell lymphoma (n=10), malignant melanoma (n=10), Ewing's sarcoma/primitive neuroectodermal tumor (EWS/PNET, n=5)] and non-keratinizing undifferentiated nasopharyngeal carcinoma (n=20). The clinical and pathologic characteristics of SDSC, and immunohistochemical (IHC) expression of broad-spectrum CKpan, CK7, CK8/18, CK5/6, p63, p40, p16, INI1, NUT and neuroendocrine markers (Syn, CgA, CD56) were evaluated. In situ hybridization (ISH) was used to detect EBER and fluorescence in situ hybridization (FISH) to detect INI1 gene deletion. Results: The 16 cases of SDSC accounted for 1.3% (16/1 218) of all malignant sinonasal tumors in the author's unit during this time period, and 2.4% (16/657) of all malignant epithelial tumors. Microscopically, there was no clear squamous and adenomatous differentiation, but "rhabdoid-like" cells, are often seen. All SDSC cases were positive for CKpan and CK8/18, negative for INI1; Epstein-Barr virus was not detected by ISH; and INI1 gene deletion was observed in all 11 SDSC patients with FISH. Twelve cases were followed up for 3-47 months. One died of tumor-related diseases half a year after diagnosis, and the remaining patients were alive with tumor, the longest survival time was 47 months. Conclusion: SDSC should be differentiated from a variety of poorly-differentiated tumors in the sinonasal area. Histologically, SDSC has no clear differentiation, but the tumor cells are characteristically basal-like or rhabdoid-like, with non-specific vacuoles, translucent or vacuolar nuclei, prominent nucleoli and necrotic foci. They are negative for INI1 IHC staining, and FISH demonstrates INI1 gene deletion. The clinical prognosis is still unclear, further studies on its biologic behavior and treatment methods are warranted.

Construction of a new cervical anatomically adaptive titanium mesh cage based on measurements of cervical geometry: A morphological and cadaveric study

Mismatch between the titanium mesh cage and cervical geometries is an important factor that induces subsidence in anterior cervical corpectomy and fusion (ACCF). The aim of the present study was to construct a new quadrate anatomically adaptive titanium mesh cage (AA-TMC) that matches well with the cervical geometries and segmental alignment in one- and two-level ACCF. Computed tomography (CT) scans of 54 individuals were used to measure the cervical endplate geometries. X-rays of 74 young individuals were used to measure the intervertebral body angle (IBA) and intervertebral body height (IBH) of the surgical segments. The AA-TMC was designed based on these measured parameters. A total of 18 cervical cadaveric specimens underwent successive one- and two-level ACCF using the AA-TMC. Postoperatively, the specimens underwent CT scanning to assess the degree of matching of the TMC-endplate interface (TEI), IBA and IBH. A TEI interval <0.5 mm was considered well matching. In the sagittal plane, 93.8% of the inferior endplates were arched, whereas 94.8% of the superior endplates were flat. In the coronal plane, 82.9% of the inferior endplates and 93.8% of the superior endplates were flat. A total of 91.7 and 94.4% of the TEIs were well matched in one- and two-level ACCF, respectively. The postoperative IBA and IBH values were consistent with the values of young individuals. The AA-TMC achieved good matching with cervical geometries and segmental alignment in one- and two-level ACCF, and is proposed for use in ACCF to increase the contact at the TEI and achieve sufficient lordosis restoration.

β-Sitosterol-loaded solid lipid nanoparticles ameliorate complete Freund's adjuvant-induced arthritis in rats: involvement of NF-кB and HO-1/Nrf-2 pathway

Rheumatoid arthritis (RA), autoimmune disease that is categorized via chronic inflammation manifestation, obesity, cardiovascular risk and even enhanced the mortality and affect the 0.3 and 1% of population worldwide. The current experimental study was scrutinize the anti-arthritic effect of β-sitosterol loaded solid lipid nanoparticles (SLN) against complete Fruend adjuvant (CFA)-induced arthritis via dual pathway. Double emulsion solvent displacement method was used for the preparation of β-sitosterol solid lipid nanoparticles (SLN). CFA was used to induce arthritis and rats were divided into different groups for 28 days. Biochemical, anti-inflammatory, pro-inflammatory cytokines and inflammatory mediator were estimated, respectively. Receptor activator of nuclear factor kappa-B ligand (RANKL), signal transducer and activator of transcription-3 (STAT3) nuclear factor erythroid 2–related factor 2 (Nrf₂), Heme Oxygenase-1(HO-1) and Nuclear factor-κB (NF-κB) expression were estimated. β-sitosterol-SLN significantly (p < .001) reduced the paw edema, arthritic index and increased the body weight. β-sitosterol-SLN increased the redox status of synovium {reduce the malonaldehyde (MDA) and increase superoxide dismutase (SOD), glutathione (GSH) and catalase (CAT)} level and reduced the cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-2, interleukin-6, interleukin-16, interleukin-17 and increased level of interleukin-10, Transforming growth factor beta (TGF-β). β-sitosterol-SLN significantly (p < .001) reduced the level of cyclooxygenase-2 (COX-2), prostaglandin E₂ (PGE₂), vascular Endothelial Growth Factor (VEGF) and NF-κB. β-sitosterol-SLN significantly increased the expression of HO-1,Nrf₂ and decreased the expression of NF-κB, RANKL, STAT3. In conclusion, β-sitosterol SLN showed the antiarthritic effect via suppression of NF-kB and activation of HO-1/Nrf-2 pathway.

Accuracy of cervical pedicle screw placement with four different designs of rapid prototyping navigation templates: a human cadaveric study

PURPOSE

Due to the high perforation rate of cervical pedicle screw placement, we have designed four different types of rapid prototyping navigation templates to enhance the accuracy of cervical pedicle screw placement.

METHODS

Fifteen human cadaveric cervical spines from C2 to C7 were randomly divided into five groups, with three specimens in each group. The diameter of pedicle screw used in this study was 3.5 mm. Groups 1-4 were assisted by the two-level template, one-level bilateral template, one-level unilateral template and one-level point-contact template, respectively. Group 5 was without any navigation template. After the surgery, the accuracy of screw placement in the five groups was evaluated using postoperative computed tomographic scans to observe whether the screw breached the pedicle cortex.

RESULTS

A total of 180 pedicle screws were inserted without any accidents. The accuracy rate was 75%, 100%, 100%, 91.7%, and 63.9%, respectively, from Groups 1 to 5. All the template groups were significantly higher than Group 5, though the two-level navigation template group was significantly lower than the other three template groups. The operation time was 4.72 ± 0.28, 4.81 ± 0.29, 5.03 ± 0.35, 8.42 ± 0.36, and 10.05 ± 0.52 min, respectively, from Groups 1 to 5. The no template and point-contact procedures were significantly more time-consuming than the template procedures.

CONCLUSION

This study demonstrated that four different design types of navigation templates achieved a higher accuracy in assisting cervical pedicle screw placement than no template insertion. However, the two-level template's accuracy was the lowest compared to the other three templates. Meanwhile, these templates avoided fluoroscopy during the surgery and decreased the operation time. It is always very challenging to translate cadaveric studies to clinical practice. Hence, the one-level bilateral, unilateral, and point-contact navigation templates designed by us need to be meticulously tested to verify their accuracy and safety.

[Ruptured chordae tendineae of tricuspid valve in neonate with intractable persistent pulmonary hypertension: a case report and literature review]

Objective: To analyze the clinical characteristics and treatment of tricuspid valve prolapse caused by chordal rupture complicated with persistent pulmonary hypertension in neonates. Methods: The clinical data of a male neonate with tricuspid valve prolapse complicated with persistent pulmonary hypertension admitted to the Neonatal Intensive Care Unit of Children's Hospital of Hebei Province in November 2018 was analyzed retrospectively. Related literature up to September 2020 was searched with the strategy of "(neonate OR newborn) AND (tricuspid valve prolapse) AND (rupture OR necrosis) AND (papillary muscle OR chordae tendineae) AND (pulmonary hypertension)" in Wanfang, CNKI and PubMed database in Chinese and English. The characteristics of the disease were summarized. Results: A male full-term neonate was admitted due to presenting severe cyanosis for 9 hours. He was born by caesarean section and presented severe cyanosis and dyspnea at 10 min of ages, unresponsive to the positive airway pressure resuscitation. After 9 hours of mechanical ventilation, there was no improvement. Thus he was transferred to Children's Hospital of Hebei Province. On admission, the initial blood gas analysis showed an arterial partial pressure of oxygen of 22.5 mmHg (1 mmHg=0.133 kPa). The echocardiography revealed prolapsed anterior leaflet of tricuspid valve, severe tricuspid regurgitation (TR) and pulmonary artery hypertension, and right to left shunt via a patent foramen ovale. The arterial duct was closed. The chest X-ray was normal. The boy was treated with nitric oxide, milrinone, and continued mechanical ventilation initially. Addition of prostacyclin analog (treprostinil) on day 3 led to significant improvement of pulmonary blood flow, oxygenation, and stabilization, so that the extracorporeal membrane oxygenation therapy was avoided. At 11 months after birth, the boy underwent cardiac surgery. At surgery, the rupture of chordal tendineae in anterior leaflet of tricuspid valve was found. Tricuspid annuloplasty, valvuloplasty and repair of patent foramen ovale were successfully performed. The follow-up echocardiogram at postoperative 3 months showed only mild tricuspid insufficiency. The boy was well at last follow-up at 22 months of age with normal cognitive skill development. According to literature, 20 cases of papillary muscle or chordae tendineae rupture in neonates had been reported in 12 English papers. Among the total 21 neonates, there were 12 male infants and only one premature infant with gestational age of 33 weeks. They presented with profound cyanosis soon after birth. All of them received endotracheal intubation and mechanical ventilation. Other treatments included inhalation of nitric oxide, intravenous milrinone, vasoactive drugs, diuretics and prostacyclin, etc. Extracorporeal membrane oxygenation (ECMO) was used in 6 infants as a bridge to surgical treatment. Two cases reported earlier death of cardiopulmonary failure without operation and the rest 19 survived after surgery. The followed surgery or autopsy revealed that all of them had tricuspid valve prolapse, rupture of papillary muscle or chordae tendineae. Conclusions: The severe TR resulting from rupture of papillary muscle or chordate tendineae in neonates is rare and could cause severe hypoxemia. Early recognition, adequate cardiopulmonary support to stabilize the hemodynamic status and timely surgery can significantly reduce the mortality.

Bone marrow mesenchymal stem cells-derived exosomes reduce apoptosis and inflammatory response during spinal cord injury by inhibiting the TLR4/MyD88/NF-κB signaling pathway

Spinal cord injury (SCI) is one of the most common destructive injuries, which may lead to permanent neurological dysfunction. Currently, transplantation of bone marrow mesenchymal stem cells (BMSCs) in experimental models of SCI shows promise as effective therapies. BMSCs secrete various factors that can regulate the microenvironment, which is called paracrine effect. Among these paracrine substances, exosomes are considered to be the most valuable therapeutic factors. Our study found that BMSCs-derived exosomes therapy attenuated cell apoptosis and inflammation response in the injured spinal cord tissues. In in vitro studies, BMSCs-derived exosomes significantly inhibited lipopolysaccharide (LPS)-induced PC12 cell apoptosis, reduced the secretion of pro-inflammatory factors including tumor necrosis factor (TNF)-α and IL (interleukin)-1β and promoted the secretion of anti-inflammatory factors including IL-10 and IL-4. Moreover, we found that LPS-induced protein expression of toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and nuclear transcription factor-κB (NF-κB) was significantly downregulated after treatment with BMSCs-derived exosomes. In in vivo studies, we found that hindlimb motor function was significantly improved in SCI rats with systemic administration of BMSCs-derived exosomes. We also observed that the expression of pro-apoptotic proteins and pro-inflammatory factors was significantly decreased, while the expression of anti-apoptotic proteins and anti-inflammatory factors were upregulated in SCI rats after exosome treatment. In conclusion, BMSCs-derived exosomes can inhibit apoptosis and inflammation response induced by injury and promote motor function recovery by inhibiting the TLR4/MyD88/NF-κB signaling pathway, which suggests that BMSCs-derived exosomes are expected to become a new therapeutic strategy for SCI.

Application of ultrasound during electrode implantation for sacral neuromodulation in patients with neurogenic bladder secondary to spinal cord disease: a retrospective study

PURPOSE

To compare the use of intraoperative ultrasound with X-ray fluoroscopy during sacral neuromodulation lead electrode placement in patients with neurogenic bladder secondary to spinal cord disease.

METHODS

We reviewed the medical records of 52 patients who underwent sacral neuromodulation (SNM) lead electrode implantation under fluoroscopy or ultrasound guidance from July 2016 to July 2019. The operating time, number of electrode contacts with stimulus responses, minimum voltage that causes a stimulus response, and rate of standard lead electrode placement were used to assess the differences between the two methods. All patients were evaluated by recording bladder diaries, postvoid residual volumes before and during the testing period. Permanent SNM implantation is acceptable if symptoms improve by at least 50%.

RESULTS

The operating time decreased from 87.1 ± 25.19 min in the X-ray group to 68.2 ± 25.20 min (p < 0.05) in the ultrasound group. The number of electrode contacts with stimulus responses, rate of standard lead electrode placement, and implantable pulse generator (IPG) placement rate were not significantly different between the two groups (p > 0.05). There was no radiation exposure during the operation in the ultrasound group. No incisional infections, hematomas, or other critical complications were reported in either groups.

CONCLUSION

Ultrasound can be applied to safely place lead electrode for sacral neuromodulation and leads to no radiation exposure to the patient, surgeon, and operating room staff and a shortened operating time while maintaining the same efficacy as X-ray.

Myelin Debris Stimulates NG2/CSPG4 Expression in Bone Marrow-Derived Macrophages in the Injured Spinal Cord

Although the increased expression of members of the chondroitin sulfate proteoglycan family, such as neuron-glial antigen 2 (NG2), have been well documented after an injury to the spinal cord, a complete picture as to the cellular origins and function of this NG2 expression has yet to be made. Using a spinal cord injury (SCI) mouse model, we describe that some infiltrated bone marrow-derived macrophages (BMDMΦ) are early contributors to NG2/CSPG4 expression and secretion after SCI. We demonstrate for the first time that a lesion-related form of cellular debris generated from damaged myelin sheaths can increase NG2/CSPG4 expression in BMDMΦ, which then exhibit enhanced proliferation and decreased phagocytic capacity. These results suggest that BMDMΦ may play a much more nuanced role in secondary spinal cord injury than previously thought, including acting as early contributors to the NG2 component of the glial scar.

The 2020 Yearbook of Neurorestoratology

COVID-19 has been an emerging and rapidly evolving risk to people of the world in 2020. Facing this dangerous situation, many colleagues in Neurorestoratology did their best to avoid infection if themselves and their patients, and continued their work in the research areas described in the 2020 Yearbook of Neurorestoratology. Neurorestorative achievements and progress during 2020 includes recent findings on the pathogenesis of neurological diseases, neurorestorative mechanisms and clinical therapeutic achievements. Therapeutic progress during this year included advances in cell therapies, neurostimulation/neuromodulation, brain-computer interface (BCI), and pharmaceutical neurorestorative therapies, which improved neurological functions and quality of life for patients. Four clinical guidelines or standards of Neurorestoratology were published in 2020. Milestone examples include: 1) a multicenter randomized, double-blind, placebo-controlled study of olfactory ensheathing cell treatment of chronic stroke showed functional improvements; 2) patients after transhumeral amputation experienced increased sensory acuity and had improved effectiveness in work and other activities of daily life using a prosthesis; 3) a patient with amyotrophic lateral sclerosis used a steady-state visual evoked potential (SSVEP)-based BCI to achieve accurate and speedy computer input; 4) a patient with complete chronic spinal cord injury recovered both motor function and touch sensation with a BCI and restored ability to detect objects by touch and several sensorimotor functions. We hope these achievements motivate and encourage other scientists and physicians to increase neurorestorative research and its therapeutic applications.

Exosomes with high level of miR-181c from bone marrow-derived mesenchymal stem cells inhibit inflammation and apoptosis to alleviate spinal cord injury

Stem cell transplantation is a promising method in the treatment of spinal cord injury (SCI). Researches have shown that stem cell-derived exosomes as well as its contents such as microRNAs contribute to the protective effects of stem cell against SCI. However, the effects of exosomes derived from bone marrow stem cells on SCI and the underlying mechanisms remain unknown. In this study, we collected bone marrow stem cells derived exosomes (BMSCs-exo) to deal with SCI rats and LPS induced microglia to explore the possible mechanisms. We found that BMSCs-exo showed significant effects on decreasing pro-inflammatory cytokines as well as increasing Basso-Beattie-Bresnahan score after acute SCI. MicroRNA-181c levels in tissue were elevated with the use of BMSCs-exo. Then we verified the effect in vitro and found that in LPS induced microglia, the administration of BMSCs-exo could inhibit the expression of pro-inflammatory cytokines, and the phosphorylation of NF-κB signal was also suppressed. During which, the expression of microRNA-181c in microglia was elevated. When LPS induced microglia were treated with BMSCs-exo over-expressing microRNA-181c, the levels of pro-inflammatory cytokines decreased. Then bioinformatics techniques were used to detect the possible target gene of microRNA-181c and then PTEN was found as a candidate. Further experiments showed that the protection effects of BMSCs-exo over-expressing microRNA-181c could be antagonized by the elevation of PTEN expression both in vitro and in vivo. In conclusion, we verified that BMSCs-exo could protect against SCI through its content microRNA-181c which suppressed the inflammation in microglia and spinal cord. It was related to the inhibition of PTEN and the suppression of NF-κB signal, and finally decreasing inflammation and apoptosis in spinal cord and improved SCI.

Biomechanical properties of a novel nonfusion artificial vertebral body for anterior lumbar vertebra resection and internal fixation

The aim of the study was to evaluate the biomechanical properties of a novel nonfused artificial vertebral body in treating lumbar diseases and to compare with those of the fusion artificial vertebral body. An intact finite element model of the L1–L5 lumbar spine was constructed and validated. Then, the finite element models of the fusion group and nonfusion group were constructed by replacing the L3 vertebral body and adjacent intervertebral discs with prostheses. For all finite element models, an axial preload of 500 N and another 10 N m imposed on the superior surface of L1. The range of motion and stress peaks in the adjacent discs, endplates, and facet joints were compared among the three groups. The ranges of motion of the L1–2 and L4–5 discs in flexion, extension, left lateral bending, right lateral bending, left rotation and right rotation were greater in the fusion group than those in the intact group and nonfusion group. The fusion group induced the greatest stress peaks in the adjacent discs and adjacent facet joints compared to the intact group and nonfusion group. The nonfused artificial vertebral body could better retain mobility of the surgical site after implantation (3.6°–8.7°), avoid increased mobility and stress of the adjacent discs and facet joints.

[Diagnosis of adult Philadelphia chromosome-like acute lymphoblastic leukemia by fluorescence in situ hybridization]

目的

建立应用荧光原位杂交技术（FISH）筛查成人Ph样急性淋巴细胞白血病（ALL）的体系。

方法

根据Ph样ALL的遗传学特征，设计了针对ABL1、ABL2、JAK2、EPOR、CRLF2、CSF1R、PDGFRB、P2RY8等基因断裂重排的FISH探针；对BCR-ABL1、ETV6-RUNX1、MLL基因断裂重排和E2A断裂重排均阴性的B-ALL，采用FISH进行Ph样ALL筛查，并结合流式免疫表型、靶向二代测序突变检测和RNA测序进行Ph样ALL诊断分析。

结果

2016年1月至2019年4月，南方医院血液科收治189例成人B-ALL，经FISH和（或）PCR检测，BCR-ABL1、ETV6-RUNX1、MLL断裂重排或E2A断裂重排阳性者共83例；其余106例患者接受Ph样ALL FISH探针筛查，其中，12例（11.3％）检出典型的Ph样ALL特异基因断裂重排，2例检出基因缺失。经RNA测序进一步验证，FISH检测Ph样ALL基因断裂重排结果灵敏度为71.4％，特异度为95.8％。综合免疫表型、靶向二代测序突变检测和RNA测序，共诊断融合基因阳性Ph样ALL 14例（13.2％）。

结论

FISH技术检测Ph样ALL具有较高的特异性，结合免疫表型和测序技术可完善诊断体系。

Common variants in MAEA gene contributed the susceptibility to osteoporosis in Han Chinese postmenopausal women

Background

Osteoporosis (OP) is a complex bone metabolism disorder characterized by the loss of bone minerals and an increased risk of bone fracture. A recent study reported the relationship of the macrophage erythroblast attacher gene (MAEA) with low bone mineral density in postmenopausal Japanese women. Our study aimed to investigate the association of MAEA with postmenopausal osteoporosis (PMOP) in Han Chinese individuals.

Methods

A total of 968 unrelated postmenopausal Chinese women comprising 484 patients with PMOP and 484 controls were recruited. Four tag single nucleotide polymorphisms (SNPs) that covered the gene region of MAEA were chosen for genotyping. Single SNP and haplotypic association analyses were performed, and analysis of variance was conducted to test the correlation between blood MAEA protein level and genotypes of associated SNPs.

Results

SNP rs6815464 was significantly associated with the risk of PMOP. The C allele of rs6815464 was strongly correlated with the decreased risk of PMOP in our study subjects (OR[95% CI]=0.75[0.63-0.89], P=0.0015). Significant differences in MAEA protein blood levels among genotypes of SNP rs6815464 were identified in both the PMOP (F=6.82, P=0.0012) and control groups (F=11.5, P=0.00001). The C allele was positively associated with decreased MAEA protein levels in blood.

Conclusion

This case-control study on Chinese postmenopausal women suggested an association between SNP rs6815464 of MAEA and PMOP. Further analyses showed that genotypes of SNP rs6815464 were also associated with the blood level of MAEA protein.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-020-02140-4.

Ten years of clinical observation of olfactory ensheathing cell transplantation in patients with spinal cord injury

Objective:

To evaluate the long-term curative efficacy and safety of olfactory ensheathing cell (OEC) transplantation by 10 years of follow-up investigation.

Methods:

A follow-up observation was done on 13 patients with allograft olfactory bulb-derived OEC transplantation from September 2005 to September 2007 at the Second Affiliated Hospital of Xi’an Jiaotong University. After cell purification, amplification, and identification, a 2 × 10⁷/mL cell suspension was prepared for transplantation. In the posterior horn of the spinal cord 0.5 cm distal and proximal to the spinal cord injury zone, 4 needle points were selected to avoid the blood vessels. The needle depth was 3 mm, and the injection volume per point was 10 μL. Postoperatively and at 1 week, 4 weeks, 12 weeks, 24 weeks, 1 year, 3 years, 5 years, and 10 years after the surgery, the patient’s American Spinal Injury Association (ASIA) score, adverse reactions, and other minor observations were assessed.

Results:

All the patients did not have serious complications. No gliomas or other new organisms formed during the 10-year observation period. Eight of 13 patients had improvement in sensory function, and 5 patients showed improvement in motor function. The ASIA acupuncture, light touch, and exercise scores improved significantly 1 year after the surgery, and this improvement continued until the 10-year follow-up period. Three of 13 patients had improvement in defecation and urination, and 1 patient had improved neuralgia after spinal cord injury.

Conclusion:

OEC transplantation is safe and effective in treating spinal cord injury. The observation period of OEC transplantation is 1 to 3 years.

Clinical guidelines for neurorestorative therapies in spinal cord injury (2021 China version)

Treatment of spinal cord injury (SCI) remains challenging. Considering the rapid developments in neurorestorative therapies for SCI, we have revised and updated the Clinical Therapeutic Guidelines for Neurorestoration in Spinal Cord Injury (2016 Chinese version) of the Chinese Association of Neurorestoratology (Preparatory) and China Committee of International Association of Neurorestoratology. Treatment of SCI is a systematic multimodal process that aims to improve survival and restore neurological function. These guidelines cover real-world comprehensive neurorestorative management of acute, subacute, and chronic SCI and include assessment and diagnosis, pre-hospital first aid, treatment, rehabilitation, and complication management.

Exosomes from microRNA-126 overexpressing mesenchymal stem cells promote angiogenesis by targeting the PIK3R2-mediated PI3K/Akt signalling pathway

microRNA‐126 (miR‐126), an endothelial‐specific miRNA, is associated with vascular homeostasis and angiogenesis. However, the efficiency of miR‐126‐based treatment is partially compromised due to the low efficiency of miRNA delivery in vivo. Lately, exosomes have emerged as a natural tool for therapeutic molecule delivery. Herein, we investigated whether exosomes derived from bone marrow mesenchymal stem cells (BMMSCs) can be utilized to deliver miR‐126 to promote angiogenesis. Exosomes were isolated from BMMSCs overexpressed with miR‐126 (Exo‐miR‐126) by ultracentrifugation. In vitro study, Exo‐miR‐126 treatment promoted the proliferation, migration and angiogenesis of human umbilical vein endothelial cells (HUVECs). Furthermore, the gene/protein expression of angiogenesis‐related vascular endothelial growth factor (VEGF) and angiotensin‐1 (Ang‐1) were up‐regulated after incubation with Exo‐miR‐126. Additionally, the expression level of phosphoinositol‐3 kinase regulatory subunit 2 (PIK3R2) showed an inverse correlation with miR‐126 in HUVECs. Particularly, the Exo‐miR‐126 treatment contributed to enhanced angiogenesis of HUVECs by targeting PIK3R2 to activate the PI3K/Akt signalling pathway. Similarly, Exo‐miR‐126 administration profoundly increased the number of newly formed capillaries in wound sites and accelerated the wound healing in vivo. The results demonstrate that exosomes derived from BMMSCs combined with miR‐126 may be a promising strategy to promote angiogenesis.

Nomograms for predicting overall survival and cancer-specific survival of chondroblastic osteosarcoma patients

BACKGROUND

The establishment of precise and personalized prediction systems for chondroblastic osteosarcoma patients is important for guiding the treatment.

METHODS

The univariate logrank test and multivariate Cox regression analysis were performed to identify independent prognostic factors for overall survival (OS) and cancer-specific survival (CSS). Nomograms were constructed to estimate the OS and CSS based on these factors. Internal and external validation was performed. The predictive power of the nomograms was determined by C-index and calibration plots.

RESULTS

A total of 401 chondroblastic osteosarcoma cases were identified. Univariate and multivariate analysis revealed that age at diagnosis, histological grade, tumor size, Surveillance, Epidemiology, and End Results stage, and surgical resection were independent prognostic factors for OS and CSS. The five factors were incorporated to construct the nomograms for estimating the 3- and 5-year OS and CSS. The C-index values for the internal validation of the OS and CSS nomogram were 0.732 and 0.746, respectively, and for the external validation were 0.780 and 0.808, respectively. The calibration curves revealed that the predicted OS and CSS could well match the actual survival rate.

CONCLUSIONS

The nomograms for predicting 3- and 5-year OS and CSS were constructed and were proved to be accurate and reliable by the internal and external validation.