Association between MIR31HG polymorphisms and the risk of Lumbar disc herniation in Chinese Han population.

Lumbar disc herniation (LDH) is a common spinal disease that endangers human health. Genetic factors play a vital role in the progression of LDH. This study aimed to explore the relationship of the MIR31HG polymorphism with LDH risk in the Chinese population. Seven candidate SNPs on MIR31HG in 504 patients with LDH and 503 healthy people were genotyped by Agena MassARRAY platform. Logistic regression was used to calculate the relationship between MIR31HG polymorphism and LDH risk under different genetic models. Multi-factor dimensionality reduction (MDR) analysis was performed to evaluate the SNP-SNP interaction. We found that rs10965059 was significantly associated with a decreased risk of LDH under the dominant (OR = 0.46, 95% CI: 0.34-0.62, P < 0.001), log-additive (OR = 0.59, 95%CI: 0.45-0.76, P < 0.001), and codominant (OR = 0.40, 95%CI: 0.29-0.55, P < 0.001) models in the overall analysis. In the subgroup analyses of age, male, and complications, we found that rs10965059 was associated with a reduced risk of LDH. However, there was no significant correlation between MiR-31HG polymorphisms and risk of LDH in females. In addition, the three SNPs (rs72703442-rs2025327-rs55683539) was mapped to a 26kb LD block with D' >0.96, suggesting a significant linkage disequilibrium presence among each pair SNPs. MDR analysis showed that the best single-locus and multi-locus models for the prediction of LDH risk were rs10965059 and seven-locus models, respectively, and both of them increased LDH risk. Our results shown that in the Chinese Han population, the MIR31HG polymorphism rs10965059 was involved in a risk to symptomatic LDH, which provides a scientific basis for early screening, prevention, diagnosis and treatment of local LDH high-risk populations.

Long non-coding RNA LINC00525 interacts with miR-31-5p and miR-125a-5p to act as an oncogenic molecule in spinal chordoma.

LINC00525 is a new-researched long non-coding RNA (lncRNA) in a few cancers. This study aims at researching the function of LINC00525 in spinal chordoma and the underlying mechanism of action. LINC00525, microRNA-31-5p (miR-31-5p) and microRNA-125a-5p (miR-125a-5p) detection was performed by quantitative real-time polymerase chain reaction (qRT-PCR). We found the high expression of LINC00525 but the low levels of miR-31-5p and miR-125a-5p in spinal chordoma tissues. After LINC00525 was downregulated in spinal chordoma cells, there were inhibitory effects on cell proliferation, migration, invasion and EMT but a promoting effect on cell apoptosis. MiR-31-5p and miR-125a-5p were the downstream targets of LINC00525. The function of LINC00525 knockdown in spinal chordoma cells were achieved by upregulating miR-31-5p and miR-125a-5p. Tumorigenesis of spinal chordoma in vivo was also inhibited by knockdown of LINC00525 via the promotion of miR-31-5p and miR-125a-5p. All these results suggested that LINC00525 targeted miR-31-5p and miR-125a-5p to promote the tumorigenesis and progression of spinal chordoma. LINC00525 can be a novel molecular target in spinal chordoma.

Oral treatment with glycyrrhizin inhibits NLRP3 inflammasome activation and promotes microglial M2 polarization after traumatic spinal cord injury.

The inflammatory response induced by traumatic spinal cord injury (SCI) involves the activation of NLRP3 inflammasomes, which are closely related to the activation of microglia. Microglial polarization between M1/M2 phenotypes is a pivotal regulatory factor in neuroinflammatory responses to traumatic SCI-induced secondary injuries, and altering this polarization could be beneficial. Glycyrrhizin is a neuroprotective agent with a potent anti-inflammatory property in different neurological disorders and could potentially be useful in SCI. In this study, we investigated the potency of oral treatment with glycyrrhizin to reduce inflammation and improve functional recovery after traumatic SCI by inhibiting NLRP3 inflammasome activation and promoting microglial M2 polarization. After inducing traumatic SCI by dropping a 10 g impactor on the T9 and T10 spinal segments of male Sprague-Dawley rats, the animals were given glycyrrhizin orally immediately after injury and every 12 h for the next 3 d. Behavioral scores improved in glycyrrhizin-treated animals compared to the SCI group. The functional improvement in glycyrrhizin-treated rats paralleled the decreased expression of NLRP3 inflammasome components, such as ASC, NLRP3, and cleaved caspase-1, as well as IL-1ß and IL-18. At the histopathological level, oral treatment with glycyrrhizin diminished the SCI-enhanced production of Iba-1+CD86+ cells (M1 microglia) but improved the release of Iba-1+CD206+ cells (M2 microglia). Likewise, oral therapy with glycyrrhizin significantly enriched the protein expression levels of M2 microglia-related markers (CD206 and Arg-1) but reduced those of M1 microglia-related markers (CD86 and iNOS) in the injured spinal cord. These findings support and extend the knowledge on post-traumatic SCI glycyrrhizin-mediated neuroprotection. Glycyrrhizin's regulation of NLRP3 inflammasome activation and microglial polarization might be a new approach to understanding the anti-inflammatory potency of glycyrrhizin.

Isofraxidin attenuates IL-1ß-induced inflammatory response in human nucleus pulposus cells.

Inflammation has been demonstrated to be the key factor for intervertebral disc degeneration (IVD), which remains a major public health problem. Isofraxidin is a coumarin compound that possesses strong anti-inflammatory activity. However, the role of isofraxidin in IVD remains unclear. The aim of this study was to evaluate the effects of isofraxidin on inflammatory response in human nucleus pulposus cells (NPCs) exposed to interleukin-1ß (IL-1ß). The results proved that isofraxidin attenuated the IL-1ß-induced significant increases in inflammatory mediators and cytokines including nitric oxide (NO), inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), tumor necrosis factor alpha (TNF-α), and IL-6. Besides, isofraxidin also inhibited the induction effect of IL-1ß on matrix metalloproteinases (MMP)-3 and MMP-13. Moreover, the NF-κB activation caused by IL-1ß was significantly inhibited by isofraxidin treatment. These findings suggested that isofraxidin alleviates IL-1ß-induced inflammation in NPCs. Our work provided an idea that isofraxidin might act as a novel preventive role in IVD.

MicroRNA-30c abrogation protects against spinal cord ischemia reperfusion injury through modulating SIRT1.

Spinal cord ischemia/reperfusion (I/R) injury is a severe complication in many surgeries. Although microRNAs (miRNAs) are involved in I/R-caused spinal cord injury (SCI), the mechanism that underlies miR-30c interacted with SCI remains elusive. In this study, I/R surgery or oxygen-glucose deprivation (OGD) were performed to establish SCI model in vivo or in vitro, respectively. Basso, Beattie and Bresnahan (BBB) score, spinal cord infarct, terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) staining, flow cytometry and enzyme linked immunosorbent assays (ELISA) were used to investigate SCI. Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to examine the abundances of miR-30c and sirtuin 1 (SIRT1) either in spinal cord or PC12 cells. Luciferase assay and RNA immunoprecipitation (RIP) were performed to probe the interaction between miR-30c and SIRT1. Western blot and immunofluorescence assays were used to analyze SIRT1 protein expression. Our results showed that I/R increased miR-30c expression and induced SCI, revealed by decreasing BBB score, enhancing apoptosis, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) expression. However, miR-30c knockdown attenuated I/R-induced SCI in vivo. Moreover, depletion of miR-30c protected PC12 cells against OGD-caused apoptosis and inflammatory response. In addition, SIRT1 was limited by miR-30c, silencing of which reversed anti-miR-30c-mediated inhibitory effect on apoptosis and secretion of inflammatory cytokines in PC12 cells after OGD treatment. Collectively, abrogation of miR-30c inhibited spinal cord ischemia reperfusion injury through targeting SIRT1, providing a promising biomarker of prognosis and therapeutic for SCI.

Common variants in the GNL3 contribute to the increasing risk of knee osteoarthritis in Han Chinese population.

Osteoarthritis (OA) is a complex degenerative joint disorder, which is caused by both environmental and genetic factors. Previous studies have indicated that the GNL3 gene is associated with knee osteoarthritis (KOA) susceptibility in Europeans; however, the exact molecular mechanism is still unclear. In the present study, we investigated the potential genetic association of GNL3 with KOA in a two-stage sample of 6,704 individuals from the Han Chinese population. Subjects containing 1,052 KOA patients and 2,117 controls were considered the discovery dataset, while subjects consisting of 1,173 KOA patients and 2,362 controls were utilized as the replication dataset. Single-SNP association, imputation, and haplotypic association analyses were performed. The SNP of rs11177 in GNL3 was identified to be significantly associated with KOA after accounting for age, gender and BMI in both stages. The imputed SNP of rs6617 in SPCS1 was found to be strongly associated with KOA risk, and the significant association signal was confirmed in the replication stage. Moreover, a haplotype-based analysis also indicated a positive genetic effect of GNL3 on KOA susceptibility. In summary, our results proved that GNL3 plays an important role in the etiology of KOA, suggesting that GNL3 is a potential genetic modifier for KOA development.

Therapeutic effect of apocynin through antioxidant activity and suppression of apoptosis and inflammation after spinal cord injury.

Spinal cord injury (SCI) is a devastating condition affecting hundreds of thousands of people worldwide annually. SCI results in activation of the inflammatory response and apoptosis, and generates oxidative stress, which has deleterious effects on the recovery of motor function. Apocynin, an inhibitor of NADPH oxidase, has been demonstrated to improve neuronal functional recovery in rat models of SCI. However, the efficacy of apocynin treatment post-SCI has not been investigated. The aim of this study was to observe the effects of apocynin on the repair of acute spinal cord damage in rats and to examine the potential beneficial effects. A rat model of SCI was established, and apocynin (50 mg/kg) was administered intraperitoneally at 30 min after SCI and then every 12 h for 3 days. In order to examine oxidative tissue injury, the levels of malondialdehyde and glutathione and activities of myeloperoxidase and superoxide dismutase in the spinal cord tissues were measured. Histological evaluations were also conducted. NeuN labeling, TUNEL staining and caspase 3 immunohistochemical staining were performed to analyze neuronal damage and apoptosis around the lesion. Immunohistochemical analysis was also carried out to observe the expression of CD11b and glial fibrillary acidic protein. The expression levels of bax, bcl-2, tumor necrosis-α, interleukin (IL)-1ß and IL-6 in the spinal cord tissue were assayed by western blotting. Finally, locomotor function was evaluated using the inclined plane test and Basso, Beattie and Bresnahan scores. The results showed that treatment with apocynin decreased oxidative damage, alleviated neuronal apoptosis, inhibited the inflammatory response and resulted in the promotion of locomotor function. Therefore, this study confirmed the therapeutic efficacy of apocynin in the repair of SCI, which was probably mediated via the inhibition of apoptosis and the inflammatory response, thus promoting the restoration of nerve function.

Protective effects of necrostatin-1 on glucocorticoid-induced osteoporosis in rats.

The inhibition of bone formation has been suggested to play a central role in the pathogenesis of glucocorticoid-induced osteoporosis (GIOP). Recently, many studies suggested that there may be another mechanism involved in GIOP besides apoptosis. The aim of this study was to investigate the protective effect of Necrostatin-1 on GIOP rats. Forty male Sprague-Dawley rats were randomly divided into four groups (n=10): controls; GIOP rats; GIOP rats pretreated with alendronate; and GIOP rats pretreated with Necrostatin-1. Their bone mineral density (BMD) and body weight were measured at the beginning and at the end of the experiment. TUNEL assay, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to observe the change of cellular morphology induced by Nec-1. The biochemical analysis and histomorphometric analysis were used to evaluate the change of bone formation by Nec-1. RIP-1, RIP-3 and caspase-8 expression were evaluated by immunohistochemistry. We found more TUNEL positive osteocytes and larger lacunae volume in GIOP rats compared with the control group. However, most of the osteocytes displayed a necrotic morphology and mitochondria lesions under TEM. In contrast to alendronate, Necrostatin-1 significantly elevated the level of bone formation markers, while it had no effect on bone resorption markers. Necrostatin-1 also markedly ameliorated trabecular bone. In addition, Necrostatin-1 significantly weaken the immunoreactivity of RIP-1 in GIOP rats while had no effect on RIP-3 and caspase-8. These data suggest, for the first time, that Necrostatin-1 accelerate bone formation of glucocorticoid-induced osteoporosis in rats.

A comparative study on screw loosening in osteoporotic lumbar spine fusion between expandable and conventional pedicle screws.

INTRODUCTION: The aim of this study is to compare the rate of screw loosening and clinical outcomes of expandable pedicle screws (EPS) with those of conventional pedicle screws (CPS) in patients treated for spinal stenosis (SS) combined with osteoporosis. METHODS: One hundred and fifty-seven consecutive patients with SS received either EPS fixation (n = 80) or CPS fixation (n = 77) to obtain lumbosacral stabilization. Patients were observed for a minimum of 24 months. Outcome measures included screw loosening, fusion rate, Japanese Orthopaedic Association (JOA) scores and Oswestry disability index (ODI) scoring system, and complications. RESULTS: In the EPS group, 20 screws became loose (4.1%) in 6 patients (7.5%), and two screws (0.4%) had broken. In the CPS group, 48 screws became loose (12.9%) in 15 patients (19.5%), but no screws were broken. The fusion rate in the EPS group (92.5%) was significantly higher than that of the CPS group (80.5%). The rate of screw loosening in the EPS group (4.1%) was significantly lower than that of the CPS group (12.9%). Six EPS (1.8%) screws were removed. In the EPS group, two screws had broken but without neural complications. Twelve months after surgeries, JOA and ODI scores in the EPS group were significantly improved. There were four cases of dural tears, which healed after corresponding treatment. CONCLUSIONS: EPS can decrease the risk of screw loosening and achieve better fixation strength and clinical results in osteoporotic lumbar spine fusion.