Ubiquitin-specific protease 3 attenuates interleukin-1ß-mediated chondrocyte senescence by deacetylating forkhead box O-3 via sirtuin-3.

Osteoarthritis (OA) affects approximately 12% of the aging Western population. The sirtuin/forkhead box O (SIRT/FOXO) signaling pathway plays essential roles in various biological processes. Despite it has been demonstrated that ubiquitin-specific protease 3 (USP3) inhibits chondrocyte apoptosis induced by interleukin (IL)-1ß, the role of USP3/SIRT3/FOXO3 in the senescence of chondrocytes in OA is unclear. This study initially isolated articular chondrocytes and investigated the role of USP3 in IL-1ß-induced senescence of chondrocytes. After USP3 was overexpressed or silenced by lentivirus, expressions of genes and proteins were detected using quantitative polymerase chain reaction and immunoblotting, respectively. Cell cycle analysis was performed using flow cytometry. Reactive oxygen species (ROS) levels and senescence were analyzed. Then, SIRT3 was inhibited or overexpressed to explore the underlying mechanism. We found that overexpression of USP3 hindered IL-1ß-mediated cell cycle arrest, ROS generation, and chondrocyte senescence. The inhibition of SIRT3 blocked the protective effect of USP3 on cell senescence, whereas the overexpression of SIRT3 abolished USP3-silencing-induced cell senescence. Furthermore, SIRT3 attenuated cell senescence, probably by deacetylating FOXO3. USP3 upregulated SIRT3 to deacetylate FOXO3 and attenuated IL-1ß-induced chondrocyte senescence. This study demonstrated that USP3 probably attenuated IL-1ß-mediated chondrocyte senescence by deacetylating FOXO3 via SIRT3.

MicroRNA-221 regulates osteosarcoma cell proliferation, apoptosis, migration, and invasion by targeting CDKN1B/p27.

MicroRNAs (miRNAs, miR) are of critical importance in growth and metastasis of cancer cells; however, the underlying functions of miRNAs in osteosarcoma (OS) remain largely unknown. This study was aimed to elucidate the role of miR-221 in regulating the biological behavior of OS cells. The proliferation ability was examined by cell counting kit-8 (CCK-8) and cell cycle assay. The abilities of cell migration, invasion, and apoptosis were monitored by transwell assay and flow cytometry, respectively. The effect of miR-221 on cyclin-dependent kinase inhibitor 1B (CDKN1B) expression was evaluated by luciferase assays, real-time polymerase chain reaction, and Western blot analysis. We found that miR-221 was elevated in OS cell lines compared with the normal osteoblastic cell line. Transfection of the miR-221 inhibitor into MG63 and U-2OS cell lines obviously suppressed cell proliferation, migration, and invasion, which is accompanied with cell cycle arrest in G0/G1 phase. Furthermore, luciferase reporter assays indicated that CDKN1B is directly targeted by miR-221 in OS cells. Knockdown of CDKN1B inhibited the effects of miR-221 inhibitor, along with decreased Bax and caspase-3 and increased cyclin E, cyclin D1, Bcl-2, Snail, and Twist1 expression. The results suggested that miR-221 might act as a potentially useful target for treatment of OS.

MicroRNA-34a promotes cell cycle arrest and apoptosis and suppresses cell adhesion by targeting DUSP1 in osteosarcoma.

MicroRNAs are often deregulated in most cancer types and have important functions in carcinogenesis and cancer progression. Here, we studied the function of microRNA-34 (miR-34a) in osteosarcoma MG63 and U-2OS cells by expressed with pre-miR-34a, anti-miR-34a and corresponding negative controls, respectively. Cells proliferation, cell cycle and apoptosis was measured by MTT and flow cytometry assay. The effect of miR-34a on DUSP1 expression was evaluated by luciferase assays, real-time PCR and western blot assay. The data showed that miR-34a reduced the proliferation of MG63 cells through prompting cell cycle arrest at G0/G1 phase, cell apoptosis, and suppressed cell adhesion ability. Whereas anti-miR-34a increases U-2OS cell proliferation by preventing cell apoptosis, and promotes cell adhesion. Finally, we identified Dual-specificity phosphatase 1 (DUSP1) as the target gene of miR-34a in osteosarcoma cells and confirmed that DUSP1 enhanced the proliferation through inhibiting cell cycle arrest at G0/G1 phase and apoptosis, and inhibits the decreased cell adhesion induced by miR-34a. However, inhibition of DUSP1 resulted in substantially decreased proliferation and adhesion, and cell cycle arrest in G0/G1 phase and cell apoptosis similar to that observed with miR-34a in U-2OS cells. Our findings find out an important function of miR-34a as a novel tumor-suppressor in osteosarcoma pathogenesis through inhibition of DUSP1.

Treatment of femoral neck fracture with percutaneous compression plate: preliminary results in 74 patients.

OBJECTIVE: The purpose of this study was to present the surgical technique and clinical results of percutaneous compression plate (PCCP) for the treatment of femoral neck fractures. METHODS: Between December 2010 and April 2013, 74 consecutive patients with 74 femoral neck fractures were treated by closed reduction and PCCP implants in our university hospital. Their mean age was 51.3 years (range, 15-83 years); 38 (51.4%) were male and 46 (62.2%) of the fractures were on the left. The patients' clinical and radiographic data were analyzed retrospectively. RESULTS: There were 45 undisplaced (60.8%) and 29 displaced fractures (39.2%). Eight patients (10.8%) were lost to follow-up. The mean duration of follow-up was 18.8 months for the remaining 66 patients. At the last follow-up, mean Harris hip score was 92.9 (range, 75-100), and 65 patients (98.5%) had excellent and good outcomes. Sixty-five patients (98.5%) were able to walk independently and one (1.5%) with walking-sticks. The mean time to clinical fracture healing was 3.9 months. There were no cases of nonunion. Two patients (3.0%) had delayed union and two (3.0%) developed avascular necrosis, one of 29 (3.7%) with a displaced fracture and one of 45 (2.6%) with an undisplaced fracture. There were no other complications or prosthetic replacement. CONCLUSIONS: PCCP is a stable internal fixation device that resists axial and rotational stresses. Our PCCP procedure has a low incidence of nonunion and avascular necrosis.

Cannabinoid receptor-2 selective antagonist negatively regulates receptor activator of nuclear factor kappa B ligand mediated osteoclastogenesis.

BACKGROUND: The cannabinoid receptor-2 (CB2) is important for bone remodeling. In this study, we investigated the effects of CB2 selective antagonist (AM630) on receptor activator of nuclear factor kappa B (RANK) ligand (RANKL) induced osteoclast differentiation and the underlying signaling pathway using a monocyte-macrophage cell line-RAW264.7. METHODS: RAW264.7 was cultured with RANKL for 6 days and then treated with AM630 for 24 hours. Mature osteoclasts were measured by tartrate-resistant acid phosphatase (TRAP) staining using a commercial kit. Total ribonucleic acid (RNA) was isolated and real-time reverse transcriptase-polymerase chain reaction (RT-PCR) was done to examine the expression of RANK, cathepsin K (CPK) and nuclear factor kappa B (NF-κB). The extracellular signal-regulated kinase (ERK), phosphorylation of ERK (P-ERK) and NF-κB production were tested by Western blotting. The effect of AM630 on RAW264.7 viability was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay. RESULTS: AM630 did not affect the viability of RAW264.7. However, this CB2 selective antagonist markedly inhibited osteoclast formation and the inhibition rate was dose-dependent. The dose of ≥ 100 nmol/L could reduce TRAP positive cells to the levels that were significantly lower than the control. AM630 suppressed the expression of genes associated with osteoclast differentiation and activation, such as RANK and CPK. An analysis of a signaling pathway showed that AM630 inhibited the RANKL-induced activation of ERK, but not NF-κB. CONCLUSION: AM630 could inhibit the osteoclastogenesis from RAW264.7 induced with RANKL.

ACDF with the PCB cage-plate system versus laminoplasty for multilevel cervical spondylotic myelopathy.

STUDY DESIGN: A nonrandomized controlled trial. OBJECTIVE: To compare the clinical outcomes, radiographic changes, and complications of patients with multilevel cervical spondylotic myelopathy who underwent ACDF with the plate cage benezech (PCB) implant system and laminoplasty. SUMMARY OF BACKGROUND DATA: Using anterior or posterior surgery for multilevel cervical spondylotic myelopathy continues to be the subject of considerable debate. Studies on the comparison of the 2 approaches are limited and few studies focus on anterior cervical discectomy and fusion (ACDF) versus laminoplasty. METHODS: We evaluated 52 consecutive patients (25 patients for the ACDF group and 27 patients for the laminoplasty group) at our institution from 2002 to 2007. The clinical and radiographic backgrounds of both the groups were comparable. The mean independent follow-up duration was 25.4 months and 24.5 months, respectively (P>0.05). The clinical outcomes, radiographic changes, and complications were compared between the 2 groups. RESULTS: As compared with the ACDF group, the laminoplasty group required a longer operative time (187.78 min vs. 115.92 min) and caused more operative blood loss (361.11 mL vs. 118.48 mL). Both the groups significantly improved the JOA score (P<0.001), and the recovery rate was similar (59.79% for the ACDF group vs. 59.54% for the laminoplasty group, P>0.05). The cervical ROM significantly decreased after surgery for both the groups (P<0.05), while the laminoplasty group had a lower decrease rate of ROM than the ACDF group (11.39% vs. 29.45%, P<0.05). The complications for the ACDF group were significantly more than the laminoplasty group (P<0.05). CONCLUSIONS: Both ACDF with the PCB system and laminoplasty are effective therapies for multilevel cervical spondylotic myelopathy. As compared with laminoplasty, ACDF with the PCB system requires a shorter operative time and causes less operative blood loss, but has a higher decrease rate of the cervical ROM and more complications.

Kyphoplasty does not maintain all restored height postoperatively: a prospective, comparative study.

From January to December 2008, balloon kyphoplasty was performed on 45 consecutive female patients with primary single-segment vertebral compression fractures as an inpatient procedure. All of the treated vertebral bodies were located within the thora-columbar region (T11-L2). Demographic data such as age, body mass index, fracture age, hospital stay, lumbar spine bone mineral density, and amount of bone cement injected per vertebrae were recorded. Patients were analyzed clinically by ambulatory status and the visual analog scale (VAS) for pain. Lateral radiographs were used to measure changes in anterior vertebral height. Mean anterior vertebral height increased from 58.9%+/-12.50% pre-kyphoplasty to 79.8%+/-7.12% post-kyphoplasty (P<.001).Two groups were defined based on the percentage of height restoration achieved: group A (18 patients) with a height restoration of at least 20%, and group B (27 patients) with a height restoration of 0% to 19.99% post-kyphoplasty. Mean anterior vertebral height restored in groups A and B was 28.2%+/-7.2% and 12.1%+/-6.2%, respectively (P<.05). Four patients in group A and none in group B had height loss at the treated vertebral level (P<.05). Both VAS and ambulatory status were improved after treatment (P<.05) with no significant difference between the 2 groups. Kyphoplasty can restore the collapsed vertebral height, but patients with greater height restoration were more vulnerable to a loss of corrected height.

[Long-term outcomes of the revision open lumbar discectomy by fenestration: a follow-up study of more than 10 years].

OBJECTIVE: To evaluate the long-term clinical results and the factors that influences the outcomes of the revision open lumbar discectomy by fenestration. METHODS: Fifty-one patients, who underwent the second open discectomy by fenestration from January 1 1988 to December 31 1994, were followed for an average of 146.8 months (range, 120 to 203 months). The long-term follow-up results were evaluated by using the MacNab classification and the Japanese Orthopaedic Association (JOA) scoring system through direct examinations and questionnaires. Radiography was also used in patients who agreed to visit the hospital, and findings were compared with those on preoperative radiographs. RESULTS: At the final follow-up, with the MacNab classification an excellent and good outcome was achieved in 70.6% of the cases, 78.4% were satisfied with their results. The failure rate was 15.7% (8 patients). Excluding those 8 failed cases who needed another reoperation, the average improvement calculated by JOA scores was (64.6 +/- 18.2)%. The disc height of the operation site significantly decreased after surgery, nevertheless, this did not affect the long-term clinical outcome. Factors that were associated with a fair and bad outcome included smoking, isolated trauma or injury, fibrosis and the length of the remaining or recurrent primary postoperative symptoms history. Psychosociological signs were probably known as negative predictors of lumbar disc surgery outcome. CONCLUSION: The long-term outcome of the revision open lumbar discectomy by fenestration in this series was favorable. Because the revision operation is typically associated with a higher complexity, selection of suitable surgical candidates and determination of valid indications for operative treatment are very important. JOA scores have proved to be easy to perform for patients and clinicians and standardize subjective data.