LncRNA SNHG5 enhances astrocytes and microglia viability via upregulating KLF4 in spinal cord injury.

This study aims to explore the role and mechanism of lncRNA SNHG5 in spinal cord injury (SCI). The interaction between SNHG5 and Krüppel-like factor 4 (KLF4) was verified by RNA pull-down and RNA immunoprecipitation (RIP) assay. Rat neural function was evaluated by BBB and BMS scores. Results showed that GFAP and Iba-1 (specific proteins for astrocytes and microglia respectively) were upregulated in spinal cord of SCI rats. Simultaneously, spinal cord also expressed substantially higher levels of SNHG5, KLF4 and eNOS (endothelial Nitric Oxide Synthase) than sham group. In traumatically injured astrocytes and microglia, SNHG5 overexpression increased cells viability, which was significantly inhibited by SNHG5 knockdown. KLF4 is a directly target for SNHG5 and is positively regulated by SNHG5. The knockdown of KLF4 effectively decreased astrocytes and microglia viability induced by SHNG5 overexpression and attenuated the pcDNA-SNHG5-mediated repression of the apoptosis. In SCI rats, the injection of Lenti-SNHG5 reduced BBB and BMS scores and also enhanced the protein expression of KLF4, eNOS, GFAP and Iba-1. In summary, our data suggested that SNHG5 promotes SCI via increasing the viability of astrocytes and microglia. The mechanism by which SNHG5 works is its directive interaction to KLF4 and contribution to eNOS upregulation.

An insertion/deletion polymorphism within the 3'­untranslated region of COL1A2 confers susceptibility to osteoporosis.

Polymorphisms located in microRNA (miRNA) binding sites may interfere with the interaction between miRNAs and mRNAs, and thereby alter the expression of genes. The current study aimed to investigate the association between an insertion/deletion (INS/DEL) polymorphism in the 3'­untranslated region (3'­UTR) of COL1A2 and the risk of developing osteoporosis. In the present study, COL1A2 was identified as a target gene of let­7g in osteoblast cells obtained from patients, using a luciferase reporter system. This was further confirmed by the observation that exogenous overexpression of let­7g in the osteoblast cells downregulated the expression of COL1A2 in the cells in the INS/INS group, however not in the DEL/DEL group. In addition, a total of 487 subjects were enrolled in the present study and their bone mineral density (BMD) was measured. The BMD at the four tested sites, the femoral neck, total left hip, L1­L4 and intertrochanteric areas, were significantly reduced in the INS/DEL or DEL/DEL group compared with the INS/INS group. Furthermore, the levels of COL1A2 and let­7g were measured in the primary osteoblasts obtained from 48 patients with osteoporosis. While the let­7g levels were comparable between each genotype group, the expression level of COL1A2 in the DEL/DEL and INS/DEL group was significantly greater compared with the INS/INS group. In conclusion, the present study demonstrated that the INS/DEL polymorphism in the 3'­UTR of COL1A2 is able to interfere with the interaction between miRNA and mRNA. In addition, it is the first study, to the best of our knowledge, to indicate that the minor allele (Del) is associated with a reduced risk of developing osteoporosis.

Whole mitochondrial genome sequence for an osteoarthritis model of spontaneous mice DBA/1 strain.

Animal models play an important role in osteoarthritis studies. Here, the complete mitochondrial genome sequence of the spontaneous mice DBA/1 strain was reported for the first time. The total length of the mitogenome was 16,769 bp. It contained the typical structure, including two ribosomal RNA genes, 13 protein-coding genes, 22 transfer RNA genes, and one non-coding control region (D-loop region). The overall GC content of the mitogenome was estimated to be 39.2%. This mitochondrial genome sequence will provide new genetic resource into osteoarthritis disease.

Carvacrol protects against spinal cord injury in rats via suppressing oxidative stress and the endothelial nitric oxide synthase pathway.

Carvacrol (CAR) is a naturally occurring phenolic monoterpene and has been demonstrated to possess a spectrum of pharmacological actions. The present study was designed to assess the neuroprotection of CAR against spinal cord injury (SCI) in rats and to identify the underlying mechanisms. SCI was induced using the modified weight­drop method in Wistar rats. CAR or saline was administered at doses of 25, 50 and 100 mg/kg for 46 days. Neuronal function following SCI was evaluated using the Basso, Beattie and Bresnahan (BBB) locomotor rating scale. Spinal cord edema was assessed by measuring the water content in spinal cord tissues. The oxidative indicators, including malondialdehyde, catalase, superoxide dismutase glutathione peroxidase and 8­isoprotane as well as endothelial nitric oxide synthase (eNOS) activity and caspase­3 were measured using corresponding commercial kits. The protein expression of eNOS and B cell lymphoma­2 (Bcl­2) as well as Bcl­2­associated X protein (Bax) was analyzed by western blot analysis. The SCI­induced rats demonstrated marked reductions in BBB scores. CAR treatment recovered neurological function with decreasing BBB scores. CAR was found to have inhibitory effects on the water content in the spinal cord, oxidative stress, eNOS, nitric oxide production and apoptosis­associated molecules, including Bax and caspase­3 as well as promoting Bcl-2 expression in SCI-induced rats. These results suggested that CAR protects against SCI via mediating oxidative stress and the eNOS signaling pathway.

Morphology study of thoracic transverse processes and its significance in pedicle-rib unit screw fixation.

BACKGROUND: Thoracic transverse process is an important anatomic structure of the spine. Several anatomic studies have investigated the adjacent structures of the thoracic transverse process. But there is still a blank on the morphology of the thoracic transverse processes. The purpose of the cadaveric study is to investigate the morphology of thoracic transverse processes and to provide morphology basis for the pedicle-rib unit (extrapedicular) screw fixation method. METHODS: Forty-five adult dehydrated skeletons (T1-T10) were included in this study. The length, width, thickness, and the tilt angle (upward and backward) of the thoracic transverse process were measured. The data were then analyzed statistically. On the basis of the morphometric study, 5 fresh cadavers were used to place screws from transverse processes to the vertebral body in the thoracic spine, and then observed by the naked eye and on computed tomography scans. RESULTS: The lengths of thoracic transverse processes were between 16.63±1.59 and 18.10±1.95 mm; the longest was at T7, and the shortest was at T10. The widths of thoracic transverse processes were between 11.68±0.80 and 12.87±1.48 mm; the widest was at T3, and the narrowest was at T7. The thicknesses of thoracic transverse processes were between 7.86±1.24 and 10.78±1.35 mm; the thickest was at T1, and the thinnest was at T7. The upward tilt angles of thoracic transverse processes were between 24.9±3.1 and 3.0±1.56 degrees; the maximal upward tilt angle was at T1, and the minimal upward tilt angle was at T7. The upward tilt angles of T1 and T2 were obviously different from the other thoracic transverse processes (P<0.01). The backward tilt angles of thoracic transverse processes gradually increased from 24.5±2.91 degrees at T1 to 64.5±5.12 degrees at T10. The backward tilt angles were significantly different between each other, except between T5 and T6. In the validation study, screws were all placed successfully from transverse processes to the vertebrae of thoracic spine. CONCLUSIONS: The length, width, and thickness of the thoracic transverse processes are suitable for screw placement. And the obvious upward and backward tilt angles provide an excellent screw passage from transverse process to the vertebral body. Screw placement from the transverse processes to the vertebral body is feasible in the thoracic spine. However, there is still some place for improvement of the pedicle-rib unit screw fixation method.

Analysis of gene expression profiles associated with functional recovery after spinal cord injury caused by sema4D knockdown in oligodendrocytes.

We previously showed that sema4D Knockdown in oligodendrocytes promotes functional recovery after spinal cord injury. In this paper, we examined gene expression profiles associated with functional recovery by PCR array. For general observation during first 4 weeks, we found that sema4D knockdown could reduce edema and stimulate SCEP. Further, PCR array analysis indicated sema4D knockdown in OPCs inhibited wound tissue angiogenesis and inflammation genes expression and upregulated axon regeneration genes expression at early phase. Our findings provided the molecular mechanism for its potential application.

[Influence of minor back trauma on surgical outcomes in patients with thoracic ossification of ligamentum flavum].

OBJECTIVE: To retrospectively explore the influences of minor back trauma on surgical outcomes in patients with thoracic ossification of ligamentum flavum (TOLF) and preliminarily detect its possible causes. METHODS: A total of 94 TOLF patients were divided into two groups according to the absence or presence of minor back trauma: MT (minor trauma, n = 16) and NT (no trauma, n = 78). They were compared in terms of gender, age, duration of symptoms, levels of involvement, numbers of involved segments, ratio of intramedullary signal changes (IMSC), pre- & post-operative JOA (Japanese Orthopedic Association) score, recovery rate (RR) at the final follow-up. Multiple regression analysis was employed to elucidate the causes related with the surgical outcomes. The MT group was further divided into two subgroups according to the intervals between trauma and surgery to clarify the influences of surgical timing on the efficacies. RESULTS: The JOA scores were 4.0 ± 1.4 and 8.4 ± 1.7 respectively in MT and NT groups at the final follow-up. The neurological status of patients improved in both groups (MT: P = 0.009, NT: P = 0.000). The patients were younger in MT groups (50 ± 11 years) than those in NT groups (58 ± 8 years) (P = 0.046). The ratio of IMSC was higher in MT groups (75.0%) than that in NT groups (25.6%) (P = 0.000). The pre- & post-operative JOA scores were lower in MT groups than those in NT groups (both P = 0.000). Multiple regression analysis revealed that the postoperative JOA score at the final follow-up was positively related with the preoperative JOA score (r = 0.60, P = 0.000) and negatively with trauma and IMSC (r = -1.82 and r = -1.87, P = 0.000) while the final postoperative RR were negatively related with trauma and IMSC (r = -26.26 and r = -33.70, P = 0.000). The surgical timing after trauma did not influence the efficacies (P = 0.147). CONCLUSION: The TOLF patients with minor back trauma have a worse post-operative recovery. A minor trauma might be a risk factor of adverse surgical outcomes.

Analysis of accuracy of computer-assisted navigation in cervical pedicle screw installation.

OBJECTIVE: To observe the accuracy of computer-assisted navigation (CAN) in cervical pedicle screw installation and to analyze the reasons for screw malposition. METHODS: From October 2004 to December 2009, 144 cervical pedicle screws were installed in 25 patients with cervical spinal diseases using CAN. Screw position and direction were measured on sagittal and transection images from intraoperative navigation and postoperative CTs. RESULTS: Among 144 screws inserted from C3 to C7, two perforated the upper pedicle wall and three deviated from the lateral pedicle wall. The rate of accurate cervical pedicle screw placement with CAN was 96.5% (139/144) in our group. There was no statistical difference in the position and direction of the pedicle screws according to navigation images and CT scans. CONCLUSION: CAN can result in high accuracy of cervical pedicle installation. The excursion phenomenon is responsible for malposition of pedicle screws. Only by understanding the navigational principles of CAN and the characteristics of cervical spinal surgery, together with personal experience, can good use be made of CAN.