Shunan Ye

Decreased in the number and function of circulation endothelial progenitor cells in patients with avascular necrosis of the femoral head

INTRODUCTION Once non-traumatic avascular necrosis of the femoral head (ANFH) happened, vascular impairment and feeble collateral circulation are followed by poor outcomes. Circulating endothelial progenitor cells (EPCs) may substantially contribute to vascular homeostasis such as vascular repair and new blood vessel growth. We investigated whether abnormalities in EPCs levels and functions are present in ANFH patients. METHODS 54 ANFH patients were enrolled, including steroid-induced (n=21), alcohol-induced (n=15) and idiopathic ANFH (n=18), and 30 healthy subjects as control (HC). The numbers of circulation EPCs were determined by fluorescence-activated cell-sorting (FACS) analysis. EPCs cultured from peripheral blood mononuclear cells on fibronectin to induce the expression of receptors for acetylated low-density lipoprotein and ulex-lectin. EPCs colony-forming units (CFUs) were observed from 54 patients and 30 healthy controls. Migratory capacity to chemo-attractants (vascular endothelial growth factor) cellular senescence levels and in vitro angiogenesis ability were assessed in age-matched subjects (n=10 per groups). RESULTS Mean numbers of circulating EPC were 1460+/-265 cells/ml in HC, 545+/-177 in ANFH, (P<0.001). Mean numbers of CFUs were 26.2+/-6.2 in HC, 19.6+/-7.7 in ANFH,(P<0.001). Although there were not significant differences in circulating EPC and CFUs among the steroid-induced, alcohol-induced or idiopathic three groups, all these risk factors contributed to the decreased circulating EPCs numbers and CFUs. In addition, EPCs from ANFH patients showed reduced migratory capacity and increased cellular senescence compared with EPCs from normal subjects, furthermore the ability of angiogenesis in vitro was also impaired. CONCLUSION Circulating endothelial progenitor cells (EPCs) numbers and functions are reduced in ANFH patients, suggesting that risk factors of ANFH may alter EPCs biology in angiogenesis and vascular repair.

MicroRNA-21 controls the development of osteoarthritis by targeting GDF-5 in chondrocytes.

Osteoarthritis is a common cause of functional deterioration in older adults and is an immense burden on the aging population. Altered chondrogenesis is the most important pathophysiological process involved in the development of osteoarthritis. However, the molecular mechanism underlying the regulation of chondrogenesis in patients with osteoarthritis requires further elucidation, particularly with respect to the role of microRNAs. MiR-21 expression in cartilage specimens was examined in 10 patients with knee osteoarthritis and 10 traumatic amputees. The effect of miR-21 on chondrogenesis was also investigated in a chondrocyte cell line. The effect of miR-21 on the expression of growth differentiation factor 5 (GDF-5) was further assessed by luciferase reporter assay and western blot. We found that endogenous miR-21 is upregulated in osteoarthritis patients, and overexpression of miR-21 could attenuate the process of chondrogenesis. Furthermore, we identified GDF-5 as the direct target of miR-21 during the regulation of chondrogenesis. Our data suggest that miR-21 has an important role in the pathogenesis of osteoarthritis and is a potential therapeutic target.

Early and intermediate follow-up results after treatment of degenerative disc disease with the Bryan cervical disc prosthesis: single- and multiple-level.

Study Design. Our clinical study design was prospective, concurrently enrolled and single-center trial of the new functional intervertebral cervical disc prosthesis (Medtronic Sofamor Danek, Memphis, TN) in the treatment of patients with single-level and multiple-level degenerative disc disease of the cervical spine. Objective. The study was designed to investigate the surgical technology skills and clinical effects of Bryan cervical disc prosthesis in Chinese, and to observe the stability and range of movement in the early and immediate postoperative period. Summary of Background Data. Recently, motion preservation has come to the forefront of emerging technologies in spine surgery. This is the important background information of the emergence of cervical arthroplasty as an alternative to arthrodesis that offers the promise of restoring normal spinal movement and reduces a kinematic strain on adjacent segments. Methods. Nineteen patients (23 discs) had spinal arthroplasty with placement of the Bryan cervical artificial disc prosthesis in our hospital. Clinical and radiologic follow-up was performed. The radiographic parameters evaluated included the treated segments and the overall curvature of the cervical spine. Results. All the patients were observed up from 8 months to 42 months (average 24 months). According to Odoms scale, all of 19 patients (23 levels) had excellent to good outcome. The range of movement recovered to the preoperative value during the follow up. The treated segment ultimately showed preservation of movement when compared with preoperative levels. No prosthesis subsidence or excursion was identified. Conclusion. Arthroplasty using the Bryan disc seemed to be safe and provided encouraging clinical and radiologic outcome in our study. Although early and intermediate results are promising, this is also a relatively new approach, long-term follow up studies are required to prove its efficacy and its ability to prevent adjacent segment disease.

Human mesenchymal stem cells induced by growth differentiation factor 5: an improved self-assembly tissue engineering method for cartilage repair.

Previous studies have shown that novel scaffold-free self-assembled constructs can be an ideal alternative for cartilage tissue engineered based on scaffolds, which has many limitations. However, many questions remain, including the choice of seeding cells and the role of growth differentiation factor 5 (GDF-5) in constructing self-assembled engineered cartilages. Moreover, whether the optimum construct is effective in human chondral defect repair is still unknown. In this study, we generated self-assembled constructs of human mesenchymal stem cells (hMSCs) using four different approaches: direct self-assembly of hMSCs with or without GDF-5, and predifferentiated hMSCs self-assembly with or without GDF-5. Histological, immunohistochemical, and biochemistry analyses indicated that the constructs generated from predifferentiated hMSCs induced by GDF-5 (Group D2) exhibited up-regulated glycosaminoglycan (GAG) and type II collagen expression and contained higher amounts of GAG and total collagen than any other group. After 3-weeks of in vitro culturing of the constructs in a chondral defects explant culture system, the contructs from Group D2 were stably adhered to the surface of the cartilage matrix. Immunohistochemically, the repair tissue was positive for type II collagen, toluidine blue, and safranin O. These data demonstrated that the generation of self-assembled tissue-engineered cartilage from chondrogenically differentiated hMSCs induced by GDF-5 is a promising therapeutic strategy for cartilage repair.

Effect of a porous tantalum rod on early and intermediate stages of necrosis of the femoral head

The aim of this study was to evaluate the effect of a porous tantalum rod implant for the treatment of early femoral head necrosis. From April 2007 to June 2009, a total of 35 femoral head necrosis patients (with 49 hips) were treated with core decompression in combination with the insertion of a porous tantalum rod. The mean age was 38.2 years (22-50 years) and the mean follow-up period was 15.2 months (12-36 months). The surgical time and blood loss were recorded. The Harris hip scores and radiological results were adopted for evaluation. The mean surgical time was 35 min, and the mean blood loss was 50 ml. The mean Harris score improved from 48.3 ± 3.2 preoperative to 83.7 ± 4.1 at the last follow-up (p < 0.05). Eight affected hips exhibited progressive pain including three hips that progressed to femoral collapse, and one revision followed by total hip arthroplasty (THA). For the patient who underwent revision and THA, the articular cartilage surface was seen to be damaged and fragmented. High-density metal particle residuals were observed on radiograph in the bone channel and femoral marrow cavity. We conclude that the selection criteria for porous tantalum implants should be early and intermediate stages of femoral head necrosis. Further study is warranted to reveal whether the metal particles released play a role in the progression of pain and failure.

Comparative intermediate and long-term results of pedicle screw and hook instrumentation in posterior correction and fusion of idiopathic thoracic scoliosis.

Study Design Prospective cohort study. Objective To comprehensively compare the intermediate and long-term results of posterior correction and fusion with segmental pedicle screw instrumentation versus those with hook constructs in idiopathic adolescent thoracic scoliosis. Summary of Background Data Posterior correction and fusion represent the current standard surgical treatment in progressive idiopathic thoracic scoliosis. The 3-column fixation of pedicle screws has been shown to be superior to all other posterior spinal fixation devices. Methods A total of 168 patients with idiopathic thoracic scoliosis at a single institution who underwent a posterior spinal fusion with segmental pedicle screw (88) or a combination of hooks and pedicle screws (80) instrumentation. Patients evaluation consisted of clinical and radiographic analysis preoperatively, postoperatively, and at final follow-up. Results All patients were prospectively evaluated with an average follow-up of 5 years (range 5 to 11 y). The average number of segments in the fusion was 9.1 (range 6 to 15) in the hook group and 8.5 in the screw group (range 5 to 12). At the final follow-up, the amount of loss of correction in thoracic curves averaged 8.4 in the hook group and 5.3 in the screw group. The difference between the mean postoperative Cobb angle and the final Cobb angle of the major curves with a preoperative value was statistically significant in the 2 groups (P<0.01). The frontal and sagittal plane correction can be satisfactorily obtained by the screw group versus the pedicle screw group. There were no cases of pseudarthrosis, deep wound infections, or any neurologic complications. Conclusions Satisfactory correction and maintenance of scoliotic curves could be obtained by pedicle screw instrumentation compared with hook constructs. Thoracic and thoracolumbar pedicle screw instrumentation is a safe and reliable method for obtaining rigid segmental spinal fixation over the conventional hook and rod.

Co-culture of mesenchymal stem cells with umbilical vein endothelial cells under hypoxic condition

SummaryBy co-culturing humm mesenchymal stem cells (hMSCs) and human umbilical rein endothelial cells (HUVECs) under hypoxia and creating a microenvironment similar to that of transplanted hMSCs for the treatment of avascular ni ANFH, the effect of hMSCs on survival, apoptosis, migration and angiogenesis of human umbilical vein endothelial cells (HUVECs) under the hypoxic condition were investigated in vitro. hMSCs and HUVECs were cultured and identified in vitro. Three kinds of conditioned media, CdM-CdMNOR, CdM-CdMHYP and HUVEC-CdMHYP were prepared. HUVECs were cultured with these conditioned media under hypoxia. The survival rate, apoptosis rate, migration and angiogenesis of HUVECs were respectively detected by CCK-8, flow cytometry, Transwell and tube formation assay. The content of SDF-1α, VEGF and IL-6 in CdM was determined by ELISA. Our results showed that hMSCs and HUVECs were cultured and identified successfully. Compared with MSC-CdMNOR and HUVEC-CdMHYP groups, the survival rate, migration and angiogenesis of HUVECs in MSC-CdMHYP group were significantly increased while the apoptosis rate was declined (P<0.05). Moreover, the expression of SDF-1α, VEGF and IL-6 in MSC-CdMHYP group was up-regulated. Under hypoxia, the apoptosis of HUVECs was inhibited while survival, migration and angiogenesis were improved by co-culture of hMSCs and HUVECs. The underlying mechanism may be that hMSCs could secrete a number of cytokines and improve niche, which might be helpful in the treatment of femoral head necrosis.By co-culturing humm mesenchymal stem cells (hMSCs) and human umbilical rein endothelial cells (HUVECs) under hypoxia and creating a microenvironment similar to that of transplanted hMSCs for the treatment of avascular ni ANFH, the effect of hMSCs on survival, apoptosis, migration and angiogenesis of human umbilical vein endothelial cells (HUVECs) under the hypoxic condition were investigated in vitro. hMSCs and HUVECs were cultured and identified in vitro. Three kinds of conditioned media, CdM-CdMNOR, CdM-CdMHYP and HUVEC-CdMHYP were prepared. HUVECs were cultured with these conditioned media under hypoxia. The survival rate, apoptosis rate, migration and angiogenesis of HUVECs were respectively detected by CCK-8, flow cytometry, Transwell and tube formation assay. The content of SDF-1α, VEGF and IL-6 in CdM was determined by ELISA. Our results showed that hMSCs and HUVECs were cultured and identified successfully. Compared with MSC-CdMNOR and HUVEC-CdMHYP groups, the survival rate, migration and angiogenesis of HUVECs in MSC-CdMHYP group were significantly increased while the apoptosis rate was declined (P<0.05). Moreover, the expression of SDF-1α, VEGF and IL-6 in MSC-CdMHYP group was up-regulated. Under hypoxia, the apoptosis of HUVECs was inhibited while survival, migration and angiogenesis were improved by co-culture of hMSCs and HUVECs. The underlying mechanism may be that hMSCs could secrete a number of cytokines and improve niche, which might be helpful in the treatment of femoral head necrosis.

Aberrant CpG Islands' Hypermethylation of ABCB1 in Mesenchymal Stem Cells of Patients with Steroid-associated Osteonecrosis

Objective. Patients carrying an ABCB1 polymorphism have a higher risk of developing osteonecrosis of the femoral head (ONFH). We investigated whether aberrant dinucleotide CpG islands’ hypermethylation of ABCB1 gene existed in mesenchymal stem cells (MSC) of patients with ONFH, which results in cell dysfunction. Methods. Bone marrow was collected from the proximal femur of patients with glucocorticoid (GC)-associated ONFH (n = 22) and patients with new femoral neck fractures (n = 25). MSC were isolated by density gradient centrifugation. We investigated cell viability, intracellular reactive oxygen species (ROS) level, mitochondrial membrane potential (MMP), the amount of P-glycoprotein (P-gp) and ABCB1 transcripts, and methylation at CpG islands of ABCB1 promoter from both the femoral neck fractures group and the GC-associated ONFH group treated with or without the DNA methyltransferase inhibitor, 5′-Aza-2-deoxycytidine (5′-Aza-dC). Results. We observed that MSC from GC-associated ONFH groups showed reduced proliferation ability, elevated ROS levels, and depressed MMP when compared with the other 2 groups. Low levels of P-gp and ABCB1 transcript, as well as ABCB1 gene hypermethylation, in patients with GC-associated ONFH were also noted. Treatment with 5′-Aza-dC rapidly restored ABCB1 expression. Analysis of general expression revealed that aberrant CpG islands’ hypermethylation of ABCB1 caused sensitivity to GC and induced changes in the proliferation and oxidative stress of MSC under GC administration. Conclusion. These data suggest that aberrant CpG islands’ hypermethylation of ABCB1 gene may be responsible for individual differences in the development of GC-associated ONFH.

Structural Augmentation with Biomaterial-Loaded Allograft Threaded Cage for the Treatment of Femoral Head Osteonecrosis

Seventy-six patients with femoral head necrosis were allocated to a program of either core decompression (control group) or core decompression and implantation of a biomaterial-loaded allograft threaded cage (treatment group). All patients were followed up prospectively clinically and radiographically. In the control group, no significant improvement in Harris hip score was found, and 13 of the 22 hips had deteriorated to stage III. In the treatment group, the mean Harris hip score was improved from 62.8 to 81.6; the clinical success rate at 36 months postoperatively was 91%. Collapse was seen in 1 hip, and another 3 hips exhibited progressive collapse. The procedure is attractive as a minimally invasive and salvage procedure, which shows encouraging success rates and early clinical results in patients with Steinberg stage I-II osteonecrosis.

Elevated expression of microRNA-30b in osteoarthritis and its role in ERG regulation of chondrocyte.

ERG (ETS-related gene) belongs to the ETS family of transcription factors, and has been recently reported to contribute to homeostatic balance in skeleton cell plasticity. MicroRNA-30 (miR-30) family is also demonstrated to play a role in controlling chondrocyte differentiation. The current study investigated the miR-30b and ERG expression in articular cartilage of osteoarthritis (OA) patients. A total of 20 subjects, with 10 OA patients and 10 healthy participants, were included in this study. Human chondrosarcoma cell line SW1353 was used to explore the relationship of miR-30b and ERG in vitro. In OA patients, a significant increase of miR-30b and a decrease of ERG were observed in articular cartilage compared with Normal ones. MiR-30b mimic down-regulated the ERG mRNA and protein expression levels, while miR-30b inhibitor up-regulated ERG expression. In addition, miR-30b mimic also decreased the mRNA expression of COL2a and aggrecan, while miR-30b inhibitor had the opposite effect. Luciferase reporter assay confirmed that miR-30b targeted ERG. In conclusion, miR-30b was involved in the process of OA, and it probably functioned through its target gene ERG.