The OPG/RANKL/RANK system modulates calcification of common carotid artery in simulated microgravity rats by regulating NF-κB pathway.

Functional and structural adaptation of common carotid artery could be one of the important causes of postflight orthostatic intolerance after microgravity exposure, the mechanisms of which remain unclear. Recent evidence indicates that long-term spaceflight increases carotid artery stiffness, which might present a high risk to astronaut health and postflight working ability. Studies have suggested that vascular calcification is a common pathological change in cardiovascular diseases that is mainly manifested as an increase in vascular stiffness. Therefore, this study investigated whether simulated microgravity induces calcification of common carotid artery and to elucidate the underlying mechanisms. Four-week-old hindlimb-unweighted (HU) rats were used to simulate the deconditioning effects of microgravity on cardiovascular system. We found that simulated microgravity induced vascular smooth muscle cell (VSMC) osteogenic differentiation and medial calcification, increased receptor activator of nuclear factor κB (NF-κB) ligand (RANKL) and RANK expression, and enhanced NF-κB activation in rat common carotid artery. In vitro activation of the RANK pathway with exogenous RANKL, a RANK ligand, increased RANK and osteoprotegerin (OPG) expression in HU rats. Moreover, the expression of osteogenic markers and activation of NF-κB in HU rats were further enhanced by exogenous RANKL but suppressed by the RANK inhibitor osteoprotegerin fusion protein (OPG-Fc). These results indicated that the OPG/RANKL/RANK system modulates VSMC osteogenic differentiation and medial calcification of common carotid artery in simulated microgravity rats by regulating the NF-kB pathway.

Dual pitch titanium-coated pedicle screws improve initial and early fixation in a polyetheretherketone rod semi-rigid fixation system in sheep.

BACKGROUND: Reports on the efficacy of modifications to the thread design of pedicle screws are scarce. The aim of the study was to investigate initial and early fixation of pedicle screws with a plasma-sprayed titanium coating and dual pitch in the pedicle region (dual pitch titanium-coated pedicle screw [DPTCPS]) in a polyetheretherketone (PEEK) rod semi-rigid fixation system. METHODS: Fifty-four sheep spine specimens and 64 sheep were used to investigate initial ("0-week" controls) and early (post-operative 6 months) fixation, respectively. Sheep were divided into dual pitch pedicle screw (DPPS), standard pitch pedicle screw (SPPS), DPTCPS, and standard pitch titanium-coated pedicle screw (SPTCPS) groups. Specimens/sheep were instrumented with four screws and two rods. Biomechanical evaluations were performed, and histology at the implant-bone interface was investigated. RESULTS: At 0-week, mean axial pull-out strength was significantly higher for the DPTCPS and SPTCPS than the SPPS (557.0 ±â€Š25.2 vs. 459.1 ±â€Š19.1 N, t = 3.61, P < 0.05; 622.6 ±â€Š25.2 vs. 459.1 ±â€Š19.1 N, t = 3.43, P < 0.05). On toggle-testing, the DPTCPS was significantly more resistant than the SPPS and SPTCPS (343.4 ±â€Š16.5 vs. 237.5 ±â€Š12.9 N, t = 3.52, P < 0.05; 343.4 ±â€Š16.5 vs. 289.9 ±â€Š12.8 N, t = 3.12, P < 0.05; 124.7 ±â€Š13.5 vs. 41.9 ±â€Š4.3 cycles, t = 2.18, P < 0.05; 124.7 ±â€Š13.5 vs.79.5 ±â€Š11.8 cycles, t = 2.76, P < 0.05). On cyclic loading, maximum displacement was significantly lower for the DPTCPS than the SPPS and SPTCPS (1.8 ±â€Š0.13 vs. 3.76 ±â€Š0.19 mm, t = 2.29, P < 0.05; 1.8 ±â€Š0.13 vs. 2.46 ±â€Š10.20 mm, t = 2.69, P < 0.05). At post-operative 6 months, mean axial pull-out strength was significantly higher for the DPTCPS and SPTCPS than the SPPS (908.4 ±â€Š33.6 vs. 646.5 ±â€Š59.4 N, t = 3.34, P < 0.05; 925.9 ±â€Š53.9 vs. 646.5 ±â€Š59.4 N, t = 3.37, P < 0.05). On toggle-testing, the DPTCPS was significantly more resistant than the SPPS and SPTCPS (496.9 ±â€Š17.9 vs. 370.3 ±â€Š16.4 N, t = 2.86, P < 0.05; 496.9 ±â€Š17.9 vs. 414.1 ±â€Š12.8 N, t = 2.74, P < 0.05; 249.1 ±â€Š11.0 vs.149.9 ±â€Š11.1 cycles, t = 2.54, P < 0.05; 249.1 ±â€Š11.0 vs.199.8 ±â€Š7.2 cycles, t = 2.61, P < 0.05). On cyclic loading, maximum displacement was significantly lower for the DPTCPS than the SPPS and SPTCPS (0.96 ±â€Š0.11 vs. 2.39 ±â€Š0.14 mm, t = 2.57, P < 0.05; 0.96 ±â€Š0.11 vs. 1.82 ±â€Š0.12 mm, t = 2.73, P < 0.05). Resistance to toggle testing (370.3 ±â€Š16.4 vs. 414.1 ±â€Š12.8 N, t = 3.29, P < 0.05; 149.9 ±â€Š11.1 vs.199.8 ±â€Š7.2 cycles, t = 2.97, P < 0.05) was significantly lower and maximum displacement in cyclic loading (2.39 ±â€Š0.14 vs.1.82 ±â€Š0.12 mm; t = 3.06, P < 0.05) was significantly higher for the SPTCPS than the DPTCPS. Bone-to-implant contact was significantly increased for the DPTCPS compared to the SPPS (58.3% ±â€Š7.0% vs. 36.5% ±â€Š4.4%, t = 2.74, P < 0.05); there was no inflammatory reaction or degradation of coated particles. CONCLUSION: DPTCPSs might have stronger initial and early fixation in a PEEK rod semi-rigid fixation system.

High expression of TRIM29 (ATDC) contributes to poor prognosis and tumor metastasis by inducing epithelial­mesenchymal transition in osteosarcoma.

The association of TRIM29 overexpression with cancer progression and poor clinical prognosis has been reported in the context of several types of cancers. In the present study, we investigated the prognostic relevance of TRIM29 and its involvement in the progression of human osteosarcoma. To the best of our knowledge, this is the first study to demonstrate a major role of TRIM29 in osteosarcoma. Our results showed that the expression of TRIM29 in osteosarcoma tissues was much higher than that in normal bone tissues. Furthermore, TRIM29 expression was significantly correlated with tumor size, recurrence, metastasis and overall survival time. High expression of TRIM29 and presence of metastasis were independent predictors of poor prognosis in these patients. Both protein and mRNA expression of TRIM29 in osteosarcoma cell lines were significantly higher than those in osteoblast cell line, hFOB1.19. Moreover, the results indicated that TRIM29 promoted migration and invasive growth of osteosarcoma cells by inducing epithelial-mesenchymal transition. Therefore, ectopic expression of TRIM29 potentially contributes to metastasis and poor prognosis in patients with osteosarcoma. In summary, TRIM29 is a potential prognostic biomarker and a therapeutic target for patients with osteosarcoma.

SUVmax of 18F-FDG PET/CT correlates to expression of major chemotherapy-related tumor markers and serum tumor markers in gastric adenocarcinoma patients.

The expression of P53 was previously found by us significantly correlated with maximal standardized uptake value (SUVmax) in non-small cell lung cancer (NSCLC) patients. Hence, the aim of this study was to clarify the relationship between SUVmax and the status of the chemotherapy-related tumor marker expression or serum tumor markers in gastric adenocarcinoma patients. Sixty-four gastric adenocarcinoma patients who underwent 18F-FDG PET/CT prior to treatment were enrolled in this study. Immunohistochemistry was performed to detect changes of Her-2, P53 and Survivin in lesions, and electrochemiluminescence (ECL) method was used to quantify expression of serum CA72-4, CA19-9 and CEA of these patients. Then, the relationships between these parameters above were assessed by Spearman correlation analysis. Also, receiver-operating characteristic (ROC) curve was performed to determine the best cut-off value of SUVmax for suggesting chemotherapy resistant tumor markers. Besides, we identified a linear correlation to estimate the equations between SUVmax and the serum tumor markers. Our results showed that higher SUVmax was detected in patients with positive expression of Her-2 and P53, compared with negative groups. The Spearman correlation analysis showed that SUVmax was associated with Her-2 or P53 with the moderate relevant Pearson correlation coefficient. ROC curve analysis showed that the sensitivity and specificity of SUVmax for suggesting Her-2 or P53-positive, when the cut-off value of SUVmax was set at 3.25 or 5.45, respectively. Moreover, the relationship between SUVmax and serum tumor markers were analyzed by linear correlation analysis, and serum CA72-4 and CA19-9 could be used as independent parameters to establish an equation for SUVmax by the linear regression models. These results suggested that SUVmax of 18F-FDG PET/CT could be used to predict and evaluate Her-2 or P53 related chemotherapy resistance of gastric adenocarcinoma patients. However, before PET/CT scanning, serum tumor markers could be used to calculate the SUVmax approximately.

Midazolam and ropivacaine act synergistically to inhibit bone cancer pain with different mechanisms in rats.

Analgesic strategy of a single drug analgesia in bone cancer pain (BCP) has shifted to combined analgesia with different drugs which have different mechanism. After tumor cell inculation, the activation of signal transducer and activator of transcription (STAT3) and extracellular signal-regulated kinase (ERK) signaling pathway are involved in the development and maintenance of BCP, whereas a decrease in the expression of spinal STAT3 and ERK through using their specific blocker, lead to attenuation of BCP. Hence, in this study, we clarified that intrathecal (i.t.) injection of midazolam (MZL) and ropivacaine (Ropi) induces synergistic analgesia on BCP and is accompanied with different mechanisms of these analgesic effect. Hargreaves heat test was used to detect the analgesic effect of single dose of i.t. MZL, Ropi and their combination on the BCP rats. At consecutive daily administration experiment, thermal hyperalgesia was recorded, and immunohistochemical staining was used to detect the expression of c-Fos, spinal glial fibrillary acidic protein (GFAP) and ionized calcium binding adapter molecule-1 (IBA-1). Then, western blot analysis was used to examine spinal TSPO, GFAP, IBA-1, pERK/ERK and pSTAT3/STAT3 levels on day 14 after tumor cell inoculation. i.t. MZL or Ropi showed a short-term analgesia dose-dependently, and MZL displayed better effect on inhibition of pSTAT3 expression than pERK, but Ropi was just the reverse, then consecutive daily administrations of their combination acted synergistically to attenuate thermal hyperalgesia with downregulated spinal 'neuron-astrocytic activation' in the BCP rats. i.t. co-delivery of MZL and Ropi shows synergistic analgesia on the BCP with the inhibition of spinal 'neuron-astrocytic activation'. Spinal different signaling pathway inhibition for MZL and Ropi may be involved in this process.

The analgesic effect of rolipram is associated with the inhibition of the activation of the spinal astrocytic JNK/CCL2 pathway in bone cancer pain.

Bone cancer pain (BCP) is one of the most difficult and intractable tasks for pain management, which is associated with spinal 'neuron-astrocytic' activation. The activation of the c-Jun N-terminal kinase (JNK)/chemokine (C-C motif) ligand (CCL2) signaling pathway has been reported to be critical for neuropathic pain. Rolipram (ROL), a selective phosphodiesterase 4 inhibitor, possesses potent anti-inflammatory and anti-nociceptive activities. The present study aimed to investigate whether the intrathecal administration of ROL has an analgesic effect on BCP in rats, and to assess whether the inhibition of spinal JNK/CCL2 pathway and astrocytic activation are involved in the analgesic effects of ROL. The analgesic effects of ROL were evaluated using the Von Frey and Hargreaves tests. Immunofluorescence staining was used to determine the number of c-Fos immunoreactive neurons, and the expression of spinal astrocytes and microglial activation on day 14 after tumor cell inoculation. Enzyme­linked immunosorbent assay (ELISA) was used to detect the expression of pro-inflammatory cytokines [interleukin (IL)-1ß, IL-6 and tumor necrosis factor (TNF)-α] and chemokines (CCL2), and western blot analysis was then used to examine the spinal phosphodiesterase 4 (PDE4), ionized calcium binding adapter molecule-1 (IBA-1) and JNK levels on day 14 after tumor cell inoculation. The results revealed that ROL exerted a short-term analgesic effect in a dose-dependent manner, and consecutive daily injections of ROL exerted continuous analgesic effects. In addition, spinal 'neuron­astrocytic' activation was suppressed and was associated with the downregulation of spinal IL-1ß, IL-6 and TNF-α expression, and the inhibition of PDE4B and JNK levels in the spine was also observed. In addition, the level of CCL2 was decreased in the rats with BCP. The JNK inhibitor, SP600125, decreased CCL2 expression and attenuated pain behavior. Following co-treatment with ROL and SP600125, no significant increases in thermal hyperalgesia and CCL2 expression were observed compared with the ROL group. Thus, our findings suggest that the analgesic effects of ROL in BCP are mainly mediated through the inhibition of 'neuron­astrocytic' activation, which occurs via the suppression of spinal JNK/CCL2 signaling.

Hypoxia-induced apoptosis is blocked by adrenomedullin via upregulation of Bcl-2 in human osteosarcoma cells.

Adrenomedullin (ADM), a multifunctional regulatory peptide, is potentially induced by hypoxia in physiological and pathological tissues, including many types of malignant tumors. Recent research has demonstrated that ADM expression is highly associated with the prognosis and disease severity of human osteosarcoma. However, the effect of ADM on the apoptosis of osteosarcoma cells and its possible mechanism remain to be elucidated. In the present study, we observed that mRNA and protein levels of ADM were increased in human osteosarcoma SOSP-F5M2 cells under a hypoxic microenvironment induced by cobalt chloride (CoCl2) in a time-dependent manner. Treatment with ADM significantly blunted hypoxic-induced apoptosis, evaluated by Hoechst 33342 staining and Annexin V-FITC/PI labeling. The expression of B-cell lymphoma-2 (Bcl-2) was increased by administration of ADM; meanwhile, this effect was reversed by exogenously adding U0126, a selective inhibitor of MEK or ADM22-52 (ADM-specific receptor antagonist). These results demonstrated that ADM acted as a survival factor to inhibit hypoxic-induced apoptosis via interacting with its receptors CRLR-RAMP (2,3) in osteosarcoma cells. The anti-apoptotic function of ADM was found to be mediated by upregulation of the expression of Bcl-2 partially through activation of the MEK/ERK1/2 signaling pathway. Therefore, targeting of the ADM/ADM acceptors/ERK1/2/Bcl-2 pathway may provide a potential strategy through which to induce the apoptosis of osteosarcoma cells.

Mechanisms of tumor resistance to small-molecule vascular disrupting agents: treatment and rationale of combination therapy.

Small-molecule vascular disrupting agents (VDAs) target the established tumor blood vessels, resulting in rapidly and selectively widespread ischemia and necrosis of central tumor; meanwhile, blood flow in normal tissues is relatively unaffected. Although VDAs therapy is considered an important option for treatment, its use is still limited. The tumor cells at the periphery are less sensitive to vascular shutdown than those at the center, and subsequently avoid a nutrient-deprived environment. This phenomenon is referred to as tumor resistance to VDAs treatment. The viable periphery rim of tumor cells contributes to tumor regeneration, metastasis, and ongoing progression. However, there is no systematic review of the plausible mechanisms of repopulation of the viable tumor cells following VDAs therapy. The purpose of this review is to provide insights into mechanisms of tumor surviving small-molecule VDAs therapy, and the synergetic treatment to the remaining viable tumor cells at the periphery.

Comparison between anterior and posterior decompression for cervical spondylotic myelopathy: subjective evaluation and cost analysis.

OBJECTIVE: To compare anterior and posterior approaches for treating cervical spondylotic myelopathy (CSM) involving more than two levels, especially in regard to quality of life and cost effectiveness. METHODS: The authors studied 116 CSM patients who underwent decompressive surgery by either an anterior or a posterior approach with instrumentation. In the anterior group, 1-3 levels subtotal vertebrectomy was followed by bone graft and Orion anterior cervical locking plate fixation. In the posterior group, multilevel laminectomy with posterior screw-rod fixation was performed. Follow-up, which included radiographic assessment, clinical examination and documentation of length of any hospitalization and cost and incidence of complications, was performed 1 day before discharge, 6 months after leaving hospital, and at final follow-up. RESULTS: Both groups had improved clinical outcomes. The anterior group showed greater satisfaction but lower visual analog scale scores than the posterior group, whereas SF-36 emotional role and mental health scores were higher in the anterior group. There was no marked difference between the two groups in length of hospitalization and most of the costs of treating CSM, however treatment and examination fees were significantly higher in the posterior group. CONCLUSIONS: Both anterior and posterior decompressions (with instrumentation) are effective procedures for improving the neurological outcomes of patients with CSM. However, although the two approaches have similar health care costs, anterior cervical corpectomy (with instrumentation) seems to be subjectively assessed by patients as better.