Construction of a circular RNA-based competing endogenous RNA network to screen biomarkers related to intervertebral disc degeneration.

BACKGROUND: Intervertebral disc degeneration (IDD) is a leading cause of disability with limited treatment strategies. A better understanding of the mechanism of IDD might enable less invasive and more targeted treatments. This study aimed to identify the circular RNA (circRNA)-microRNA (miRNA)-messenger RNA (mRNA) competing endogenous RNA (ceRNA) regulatory mechanisms in IDD. METHODS : The GSE67567 microarray dataset was downloaded from the Gene Expression Omnibus database. After data preprocessing, differentially expressed circRNAs, miRNAs and mRNAs between IDD and controls were identified. A ceRNA network was constructed on the basis of the interaction between circRNAs and miRNAs, and miRNAs and mRNAs. Pathway enrichment analysis was performed on the mRNAs in the ceRNA network. Then, with 'intervertebral disc degeneration' as keywords, IDD-related Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were searched for in the Comparative Toxicogenomics Database. RESULTS: A total of 105 differentially expressed circRNAs, 84 miRNAs and 967 mRNAs were identified. After analysis, 86 circRNA-miRNA, and 126 miRNA-mRNA regulatory relationship pairs were obtained to construct a ceRNA network. The mRNAs were enriched in six KEGG signalling pathways, and four were associated with IDD: the hsa04350: TGF-beta signalling pathway, hsa04068: FoxO signalling pathway, hsa05142: Chagas disease (American trypanosomiasis) and hsa04380: Osteoclast differentiation. An IDD-related ceRNA network was constructed involving four circRNAs, three miRNAs and 11 mRNAs. Auxiliary validation showed that the expression levels of miR-185-5p, miR-486-5p, ACVR1B, FOXO1, SMAD2 and TGFB1 were consistent in different databases. CONCLUSIONS: Our study identified some circRNA-miRNA-mRNA interaction axes potentially associated with the progression of IDD, viz.: circRNA_100086-miR-509-3p-MAPK1, circRNA_000200-miR-185-5p-TGFB1, circRNA_104308-miR-185-5p-TGFB1, circRNA_400090-miR-486-5p-FOXO1 and circRNA_400090-miR-486-5p-SMAD2.

Precision Measurements and Parametric Models of Vertebral Endplates.

Detailed and comprehensive geometric data of vertebrae endplates is important and necessary to improve the fidelity of finite element models of the spine, design and ameliorate spinal implants, and understand degenerative changes and biomechanics. In this protocol, a high-speed and highly accurate scanner is employed to convert morphology data of endplate surfaces into a digital point cloud. In the software system, the point cloud is further processed and reconstructed into three dimensions. Then, a measurement protocol is performed, involving a 3D coordinate system defined to make each point a 3D coordinate, three sagittal and three frontal surface curves that are symmetrically fitted on the endplate surface, and 11 equidistant points that are selected in each curve. Measurement and spatial analyses are finally performed to obtain geometric data of the endplates. Parametric equations representing the morphology of curves and surfaces are fitted based on the characteristic points. The suggested protocol, which is modular, provides an accurate and reproducible method to obtain geometric data of vertebral endplates and may assist in more sophisticated morphological studies in the future. It will also contribute to designing personalized spinal implants, planning surgical acts, making clinical diagnoses, and developing accurate finite element models.

Manual preoperative tracheal retraction exercise decreases the occurrence of postoperative oropharyngeal dysphagia after anterior cervical discectomy and fusion.

OBJECTIVE: Preoperative tracheal retraction exercise (TRE) to minimize the occurrence of postoperative oropharyngeal dysphagia after anterior cervical spine surgery. METHODS: A total of 220 patients admitted for elective anterior cervical spine surgery from January 2013 to December 2014 were retrospectively reviewed. The patients were allocated into two groups: TRE group and control group (without TRE). Modified dysphagia scoring system (MDSS) was used for evaluating the presence and severity of dysphagia symptoms at 1 week and 1, 3, and 6 months after surgery. Demographics such as age, gender, smoking, type of procedure, number of levels operated, duration of surgery, intraoperative blood loss, and instrumentation were analyzed. The clinical outcomes in both groups were compared with Neck Disability Index (NDI), Visual Analogue Scale (VAS) for arm and neck pain, and Odom's criteria for global outcome. RESULTS: In the first week postoperatively, 86 patients (39.1%) developed dysphagia, which decreased to 72 (32.7%), 5 (2.3%), and 4 (1.8%) after 1, 3, and 6 months, respectively. The patients who received the TRE prior to surgery had significantly better MDSS scores ( p = 0.032 for second-level, 0.022 for third-level, and 0.009 for fourth-level fusions) than control group patients who did not receive TRE at the first week of surgery. At the 1-month follow-up, the followed-up patients for second- to fourth-level fusions in the TRE group had improved MDSS scores than those in the control group ( p = 0.041 for second-level, 0.025 for third-level, and 0.0011 for fourth-level fusions). MDSS scores showed no significant difference between both the groups at 1 and 3 months postoperatively for single level anterior cervical fusion. NDI and VAS scores didn't yield any significant difference. Global outcome by Odom's criteria was 88.6%. CONCLUSION: Preoperative TRE can significantly reduce the occurrence of postoperative dysphagia after ACDF surgery. During follow-up, the incidence of postoperative dysphagia was significantly lower and had resolved at 3 months in all patients.