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Bone marrow mesenchymal stem cells (BMSCs) are capable of multidirectional differentiation, and engrafted BMSCs can be used to replace damaged chondrocytes for treatment of intervertebral disc disease. However, chondroblast differentiation of implanted BMSCs is inhibited by the anoxic environment of the articular cavity. Here, we found that leptin enhanced the transformation of BMSCs into chondrocytes under hypoxic conditions. BMSCs isolated from mice were cultured in medium supplemented with leptin under hypoxia. The expression of MFN1/2 and OPA1 were increased only in BMSCs cultured in an anoxic environment. In addition, in hypoxic environments, cell energy metabolism relies on glycolysis regulated by leptin rather than by mitochondrial oxidation. The expression of the de-SUMOylation protease SENP1 was elevated, leading to Sirt3-mediated activation of PGC-1α; these processes were regulated by CREB phosphorylation, and promoted mitochondrial fusion and cell differentiation. The chondrogenic activity of BMSCs isolated from Sirt3-knockout mice was lower than that of BMSCs isolated from wild-type mice. Implantation of Sirt3-knockout murine-derived BMSCs did not significantly improve the articular cartilage layer of the disc. In conclusion, the hypoxic microenvironment promoted BMSC differentiation into chondrocytes, whereas osteoblast differentiation was inhibited. SENP1 activated Sirt3 through the deSUMOylation of mitochondria and eliminated the antagonistic effect of Sirt3 acetylation on phosphorylation. When phosphorylation activity of CREB was increased, phosphorylated CREB is then transferred to the nucleus, affecting PGC-1α. This promotes mitochondrial fusion and differentiation of BMSCs. Leptin not only maintains chondrogenic differentiation homeostasis of BMSCs, but also provides energy for differentiation of BMSCs under hypoxic conditions through glycolysis.

Background Rigid bracing is a universal effective treatment for scoliosis. However, body movement restriction and discomfort usually are its shortcomings. The purpose of this case series study was to investigate the feasibility of novel anisotropic textile braces with an artificial hinge adopting the direct three-point pressure system for the initial spinal correction and its biomechanics. Methods Five scoliotic female patients who were on average 12.2 years old with a BMI of 18.7, Risser grade of 1.6 and Cobb’s angle of 22.3˚ were recruited. The outcome measures are spinal correction, contour asymmetry, and interface pressure distribution of the brace. The correlation between the rate of in-brace correction and variables such as the Cobb’s angle, posterior trunk asymmetry index and interface pressure were studied. Results The initial in-brace rate of spinal correction ranged between 9.7% and 87%. The rate of correction based on posterior trunk asymmetry index ranged between 14.1% and 43.2%. The interface pressure from the brace ranged from 4.1 kPa to 25.6 kPa, which is comparable to that exerted by rigid braces. Based on the data in this study, no correlation was found between the in-brace rate of correction and the Cobb’s angle and the pressure exerted by the pads. Conclusions The main finding is that the anisotropic textile brace offers good initial in-brace correction through the application of the three-point pressure system with textile materials. Nevertheless, further follow-up work is recommended to investigate its long-term efficacy. Trial registration: This study was registered at ClinicalTrials.gov (NCT02271256 – Registration date 22nd October 2014).

Background.One previous work confirmed that laminar slope angle was associated with the ossification of thoracic ligamentum flavum. Several studies have investigated the relevance of disc degeneration grade, thickness of ligamentum flavum, along with cross section area of multifidus and its fatty infiltration. However, there has been no research between the angle and them. This retrospectivestudyof clinical materials from 122 patients was designed to investigate the influence of laminar slope angle on degeneration of lumbar when eliminating the interference of age.Methods.122 individuals were retrospected randomly on the basis of age difference from 687inpatients scheduled to undergo a lumbar operation between January and December 2017.We registered their age and sex, evaluated and measuredL4-L5 disc degeneration grade,correspondingcross section area of multifidus, muscle-fat index,thickness of ligamentum flavum and laminar slope angle from preoperative magnetic resonance imagingand three-dimensional computer tomography. Independent-sample T tests were used to assess the association between age and measurement indices. The Pearson correlation coefficient, and partial correlation excluding age, was also performed to analyze thecorrelation between clinical parameters.Results.Our results showed that age was positively connected withthe laminar slope angle(L4:r=0.298, p=＜0.01; L5:r=0.303, p=＜0.01). Excluding the interference of age, revealed a credibly negative relationship between the angle of L4 and the thickness of the ligamentum flavum(Left: r=-0.303, p=＜0.01;Right:r=-0.340, p=＜0.01). However, there was no correlationwithother parameters(disc: r=-0.141, p＞0.05; left multifidus: r=0.248, p＞0.05; right multifidus: r=0.225, p＞0.05; left muscle-fat index: r=0.033, p＞0.05; right muscle-fat index: r=0.016, p＞0.05).Conclusion.Excluding the interference of age, Inclination of small laminar slope angle leads to hypertrophy of lumbar ligamentum flavum.LEVEL OF EVIDENCE:Level 4.

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Longitudinal bone growth is governed by a complex network of endocrine signals including leptin. In mouse, leptin deficiency leads to distinct phenotypes in bones of the limb and spine, suggesting the appendicular and axial skeletons are subject to differential regulation by leptin. We established primary cultures for the chondrocytes from tibial and vertebral epiphyseal plates. Cellular proliferation and apoptosis were analyzed for the chondrocytes that had been treated with various concentrations of leptin. Crucial factors for chondrocyte proliferation and differentiation, such as BMP7 and Wnt3, were measured in the cells treated with leptin alone or in combination with pharmacological inhibitors of STAT and ERK signaling pathways. Primary culture of tibial epiphyseal plate chondrocytes has greater proliferating capability compared with that of vertebral epiphyseal plate chondrocytes. Leptin could promote the proliferation of tibial epiphyseal plate chondrocytes, while its effect on vertebral epiphyseal plate chondrocytes was inhibitory. Consistently, apoptosis is inhibited in tibial but promoted in vertebral epiphyseal plate chondrocytes by leptin. Importantly, leptin differentially modulates chondrogenic signaling pathways in tibial and vertebral epiphyseal chondrocytes through STAT and ERK pathways. Leptin differentially regulates chondrogenic proliferation and differentiation in appendicular and axial regions of the skeletons. The signaling pathways in these two regions are also distinct and subject to differential regulation by leptin through the STAT pathway in tibial epiphyseal plate chondrocytes but through the ERK pathway in vertebral epiphyseal plate chondrocytes. Therefore, the regulation of leptin is multi-faceted in the distinct anatomical regions of the skeleton. Knowledge gained from this system will provide insights into the pathophysiological causes for the diseases related to bone development and metabolism.

Autophagy and apoptosis are the two major modes of cell death, and autophagy usually inhibits apoptosis. The current understanding has shown that there is a complex crosstalk between the components of these two pathways. Here, we describe a transcriptional mechanism that links autophagy to apoptosis. We show that the cisplatin-resistant MG63-R12 and U2OS-R5 osteosarcoma sublines, in comparison to their parental MG63 and U2OS cells, respectively, exhibit increased autophagy but decreased apoptosis levels after treatment with cisplatin. We then used a microarray assay to examine the gene expression changes in these two cisplatin-resistant sublines and found that the expression of the transcription factor FOXO3a was dramatically decreased. Pharmacological treatment with either 3-methyladenine to inhibit autophagy or with rapamycin to activate autophagy in these two cisplatin-resistant sublines resulted in the accumulation or degradation of FOXO3a, respectively. Ectopic expression of FOXO3a in MG63-R12 and U2OS-R5 cells significantly enhanced cell sensitivity to cisplatin through a mechanism in which FOXO3a directly binds to the PUMA promoter and activates its expression, as well as its downstream event, the intrinsic apoptosis pathway. Importantly, this overexpression resulted in tumor growth inhibition in vivo. In conclusion, our results provide new insights into the molecular link between autophagy and apoptosis that involves a FOXO3a-mediated transcriptional mechanism. Importantly, our results may facilitate the development of therapeutic strategies for osteosarcoma patients who have become resistant to cisplatin therapy.

A retrospective technical report.To assess the effect of bilateral C1 laminar hooks combined with C2 pedicle screw fixation for the treatment of C1-C2 instability.Various posterior atlantoaxial fixations for C1-C2 instability have been developed. However, due to anatomic anomalies of the vertebral artery, the smallness of the pedicle, trajectories of broken screws, or a lack of surgical experience, a simple atlantoaxial fixation technique with good safety and effectiveness is urgently needed.From January 2007 to September 2012, 18 patients with C1-C2 instability who underwent posterior bilateral C1 laminar hooks combined with C2 pedicle screw fixation were evaluated. Six patients had acute odontoid fractures (Anderson IIc type), 8 patients had odontoid pseudarthrosis, 3 had os odontoideum, and 1 had a traumatic rupture of the transverse ligament. The mean age at the time of surgery was 34.1 years. The clinical and radiographic analyses were performed before and after the operation and at follow-up.The follow-up period was 12-78 months (with an average follow-up period of 25.6 mo). All patients were relieved of pain and their neurological symptoms were substantially improved. The postoperative JOA score improved significantly (t=-7.234, P0.001). No neurological or vascular complications occurred in these cases. The device was placed well and had not loosened or broken and plain radiographs revealed bony fusion in 17 patients. One patient had C1 posterior arch fracture 3 weeks postoperatively and she was followed up for 18 months without revision surgery.When appropriate patients were selected, bilateral C1 laminar hooks combined with C2 pedicle screw fixation can be an alternative method to treat C1-C2 instability effectively with a relatively simple procedure. Preoperative planning and evaluation were crucial for the solid atlantoaxial fusion.

Bone marrow mesenchymal stem cells (BMSCs) are stem cells with multidirectional differentiation potential, which can be used as seed cells to repair and reconstruct many types of tissues and organs following injury or disease. Osteogenic differentiation involves a variety of pathway and factors, including cytokines, growth factors, and hormones. In the present study, we investigated the potential role of Dishevelled in osteogenic differentiation of BMSCs in induction medium containing the methyltransferase inhibitor 5-aza-2’-deoxycytidine. The expression of Dishevelled was analyzed using the reverse transcriptase-polymerase chain reaction (RT-PCR) and a Western blot. The methylation degree of the CpG island in the promoter region of the Dishevelled gene was analyzed, and protein expression levels of Wnt, Glycogen synthase kinase-3 (GSK3), axin, Dishevelled, and β-catenin were increased after the addition of the methyltransferase inhibitor. The expression of Dishevelled increased in accordance with the differentiation of osteoblasts, and the degree of methylation of the promoter affected its expression level. In conclusion, regulating the methylation degree of the Dishevelled gene promoter region appears to influence the expression of Dishevelled and therefore the osteogenic differentiation of BMSCs.

Longitudinal bone growth is governed by a complex network of endocrine signals including leptin. In mouse, leptin deficiency leads to distinct phenotypes in bones of the limb and spine, suggesting the appendicular and axial skeletons are subject to differential regulation by leptin. We established primary cultures for the chondrocytes from tibial and vertebral epiphyseal plates. Cellular proliferation and apoptosis were analyzed for the chondrocytes that had been treated with various concentrations of leptin. Crucial factors for chondrocyte proliferation and differentiation, such as BMP7 and Wnt3, were measured in the cells treated with leptin alone or in combination with pharmacological inhibitors of STAT and ERK signaling pathways. Primary culture of tibial epiphyseal plate chondrocytes has greater proliferating capability compared with that of vertebral epiphyseal plate chondrocytes. Leptin could promote the proliferation of tibial epiphyseal plate chondrocytes, while its effect on vertebral epiphyseal plate chondrocytes was inhibitory. Consistently, apoptosis is inhibited in tibial but promoted in vertebral epiphyseal plate chondrocytes by leptin. Importantly, leptin differentially modulates chondrogenic signaling pathways in tibial and vertebral epiphyseal chondrocytes through STAT and ERK pathways. Leptin differentially regulates chondrogenic proliferation and differentiation in appendicular and axial regions of the skeletons. The signaling pathways in these two regions are also distinct and subject to differential regulation by leptin through the STAT pathway in tibial epiphyseal plate chondrocytes but through the ERK pathway in vertebral epiphyseal plate chondrocytes. Therefore, the regulation of leptin is multi-faceted in the distinct anatomical regions of the skeleton. Knowledge gained from this system will provide insights into the pathophysiological causes for the diseases related to bone development and metabolism.

Cell cycle progression in mammals is strictly controlled by a number of cyclin-dependent kinases (CDKs) and CDK inhibitors (CKIs), the expression of which is often dysregulated in cancer cells. Our previous work revealed that Cullin 4B (CUL4B), a critical component of the Cullin4B-RING E3 ligase complex (CRL4B), is overexpressed in human osteosarcoma cells through an unknown mechanism. Here, we demonstrated that CUL4B forms an E3 ligase with RBX1 (RING-box 1), DDB1 (DNA damage binding protein 1), and DCAF11 (DDB1 and CUL4 associated factor 11) in human osteosarcoma cells. In vitro and in vivo ubiquitination analyses indicated that CRL4BDCAF11 E3 ligase was able to specifically ubiquitinate a CDK inhibitor—p21Cip1 at K16, K154, K161 and K163 but not at K75 and K141. Knocking down any component of the CRL4BDCAF11 complex, including CUL4B, DDB1 or DCAF11, using short hairpin RNAs (shRNAs) attenuated the ubiquitination level of p21Cip1, inhibited osteosarcoma cell proliferation, led to cell cycle arrest at S phase, and decreased colony formation rate. Taken together, our data suggest that the CRL4BDCAF11 complex represents a unique E3 ligase that promotes the ubiquitination of p21Cip1 and regulates cell cycle progression in human osteosarcoma cells.

Background: Split spinal cord malformation (SSCM) is rare in scoliosis. This study evaluated the safety and effectiveness of one-stage surgical treatment of congenital scoliosis (CS) in patients with SSCM in a single Chinese center. Method: A retrospective study of 5 cases who underwent surgery for CS with SSCM (2 type I and 3 type II) from March 2004 to March 2012. Patients included 4 females and 1 male with a mean age of 13.8 years. All patients underwent one-stage posterior fusion surgery with resection of a bony spur firstly in SSCM type I, but we did nothing to the SSCM in type II. Clinical symptoms and radiological changes were evaluated preoperatively and for at least 2 years postoperatively. Results: Preoperatively, 5 patients had variant neurological and other symptoms. They had a mean preoperative Cobb angle of 63 ± 20° and T5-T12 kyphosis of 30 ± 21°. The mean postoperative Cobb angle was 30.2 ± 19.8° with a correction rate of 57.2 ± 17.0%. At the 3-month follow-up the Cobb angle loss was 3.0 ± 6.8°, and at the 2-year follow-up the Cobb angle loss was 6.5 ± 9.7°. Hyperkyphosis was significantly corrected after surgery but correction loss was indicated at the 2-year follow-up (p < 0.01). There were no neurological deficit complications or deteriorated neurological signs postoperatively or at follow-up. Conclusions: One-stage surgical treatment of CS with SSCM could be safe and effective, but we need further multicenter studies with larger samples. Intraspinal intervention of bone spur was recommended in SSCM type I before deformity correction, while in SSCM type II it was needless.

Study design A multicenter cross-cultural study to re-evaluate the reliability and validity of the simplified Chinese version of Scoliosis Research Society-22 (SRS-22) Patient Questionnaire. Objective To assess the concurrent validity and reliability of this instrument in mainland China. Summary of background data The SRS-22 Questionnaire was developed to assess the health-related quality of life for patients with scoliosis in the United States. More recently, the reliability and validity analyses of traditional and simplified Chinese versions of this questionnaire were performed, respectively. However, with respect to the diversity of population and large proportion of rural patients in China, a multicenter study might be necessary to re-evaluate its adaptation. Methods The original English version of the SRS-22 Questionnaire was translated into simplified Chinese. Considering the different health care systems in mainland China, the question 15 was modified; the respondent might be the parent if the patient was younger than 18 years. This multicenter study was performed by 13 scoliosis surgeons involving seven spine centers. The SRS-22 Questionnaire and a previously validated 36-Item Short-Form Health Survey Questionnaire were given to 391 patients with idiopathic scoliosis or congenital scoliosis without neurologic deficits. Of those, 136 patients were randomly selected for a second identical SRS-22 Questionnaire filled 1 week later and mailed back with a stamped return envelope. Results A total of 333 patients fully completed both SRS-22 and 36-Item Short-Form Health Survey Questionnaires. Good consistency was observed for all the five domains of the SRS-22. Poorer internal consistency was found in questions 15 and 18. If question 15 was excluded, the α coefficient would increase to 0.68. The pain domain of SRS-22 had a high ceiling effect being 67.5%. The test-retest reproducibility was observed "good" in the pain domain and "excellent" for the remaining domains of SRS-22 Questionnaire. Good (10 domains) and moderate (23 domains) correlations were demonstrated while seven domains had poor correlation. Conclusion The simplified Chinese version of the SRS-22 Questionnaire was re-evaluated by a multicenter study to respect the diversity of population and cultural differences in mainland China, which showed good internal consistency and satisfactory test-retest reproducibility. It might be useful for clinical evaluation of Chinese adolescents and young adults with scoliosis treated with bracing or surgery, although it also encountered previously reported difficulties with some of the items related to different cultures and health care systems.

The goal in the treatment of osteonecrosis of the femoral head is to preserve, not replace, the femoral head. Although many methods have been proposed, none has proved completely satisfactory. Cellular mediators as a supplement to bone grafting and decompression is an attractive approach to this problem because it combines the desirable features of other procedures, each of which has shown a certain degree of effectiveness in stimulating bone growth and repair. Basic and clinical researches have shown the efficacy of various cellular mediators (bone morphogenetic proteins, interleukins, angiogenic growth factors, etc.) in healing bone defects. The potential application of these cellular mediators to other musculoskeletal conditions, including osteonecrosis of the femoral head, only recently has been explored. The surgical alternatives may include core decompression, osteotomy, nonvascularized, and vascularized bone grafting, which might be enhanced with the use of cellular mediators. At least three of these factors are potential candidates as therapeutic modalities: cytokines, bone morphogenetic proteins, and angiogenic factors. Therefore, we hypothesized that the combination of operation and multiple cellular mediators is an attractive method to preserve the femoral head for the therapy of osteonecrosis of the femoral head.

A successful osseointegration relies on the interplay of implant surface and surrounding bone marrow cells. This study was undertaken to investigate the impact of age and gender on the bone marrow composition.Bone marrow aspirates were obtained from the discarded metaphysis region of the femoral head in 24 patients with total hip replacement. Flow cytometry was used to measure the expression of Stro-1(+) cells and BMP receptors (BMPRs)-expressing cells. ELISA was used to measure bone marrow aspirate bone morphology protein7 (BMP7) concentration.Our data demonstrates that there are diverse bone marrow profiles (Stro-1(+) cell and BMPRs(+) cells). There are no differences of Stro-1(+) cells, BMPRs(+) cells, and BMP7 concentration between male and female patients. Though there are slight increases in the number of Stro-1(+) cells and BMPRs(+) cells in younger patients (70 years old) than those of old patients (≥ 70 years old), the difference is not statistically significant. However, we found a close association between the Stro-1(+) cells, BMPR1a cells and BMP7 concentration. In addition, a correlation exists between the number of Stro-1(+) cells and BMIs of these patients.Our data suggests that the age and gender of THR patients have little impact on their bone marrow osteogenic potential. The significance of the number of the Stro-1(+) with BMPRs expression on the implant fixation and osseointegration warrants further investigation.

At present, doctors discuss the situation of scoliosis patients mainly through their x-ray photograph. Because of the complexity of human spine structure, it is very difficult for doctors to plansimulate operation or instruct design of scoliosis bracket only through the x-ray photograph of patient. In this paper, the technology of forming an STL file from CT data was introduced. The solid model of a scoliosis patient was reconstructed and transferred to RPM system. A human scoliosis model with all spine anatomical structure was manufactured using laminated object manufacturing (LOM). It has important clinical value for doctors to plansimulate operation, and it is significant for the development of integration of medicine and engineering.

This study was aimed to develop the personalized finite element model (FEM) of spine of a scoliotic adolescent. We derived the data of spine of a scoliotic adolescent using spiral computed tomography. Then by using a series of computer aided design (CAD) software, the patient-specific 3D finite element model of spine of a scoliotic adolescent was developed. Results show the 3-D FEM of spine of AIS adolescent was established according to patient-specific geometric parameters. The model had an appearance similar an reality. We concluded that the way in this study is an exact and effective one to develop the FEM of spine of scoliotic adolescent. It is possible to analyze and research the biomechanical behavior of the scoliotic spine using the personalized FEM.