Isoliensinine suppresses bone loss by targeted inhibition of RANKL-RANK binding.

BACKGROUND: Osteoporosis, a systemic metabolic bone disease, is often caused by the disruption of dynamic equilibrium between osteoclasts and osteoblasts. Overactive bone resorption, in which osteoclasts play a major role, is one of the most common and major causes of osteoporosis. Less costly and more effective drug treatments for this disease are needed. Based on the combination of molecular docking techniques and in vitro cell assays, this study aimed to explore the mechanism by which Isoliensinine (ILS) protects the bone loss by inhibiting osteoclast differentiation. METHODS: A virtual docking model based on molecular docking technology was used to investigate the interactions between ILS and the Receptor Activator of Nuclear Kappa-B (RANK)/Receptor Activator of Nuclear Kappa-B Ligand (RANKL).In this study, we determined the effective dose of action of ILS to inhibit osteoclast differentiation in vitro and, using bone resorption experiments, RT-CPR and Western Blot investigated the effects of ILS on bone resorption function and normal expression of osteoclast-associated genes and proteins, and validated potential mechanistic pathways. In vivo experiments revealed that ILS could inhibit bone loss through Micro-CT results. Finally, the molecular interaction between ILS and RANK/RANKL was investigated using biomolecular interaction experiments to verify the correctness and accuracy of the computational results. RESULTS: ILS binds to RANK and RANKL proteins, respectively, through virtual molecular docking. The Surface Plasmon Resonance (SPR) experiment results revealed that phosphorylated JNK, ERK, P38, and P65 expression was significantly downregulated when ILS were targeted to inhibit RANKL/RANK binding. At the same time, the expression of IKB-a was significantly increased under the stimulation of ILS, which rescued the degradation of IKB-a. ILS can significantly inhibit the levels of Reactive Oxygen Species (ROS) and Ca2 + concentration in vitro. Finally, the results of Micro-CT showed that ILS can significantly inhibit bone loss in vivo, indicating that ILS has a potential role in the treatment of osteoporosis. CONCLUSION: ILS inhibits osteoclast differentiation and bone loss by preventing the normal binding of RANKL/RANK, affecting downstream signaling pathways, including MAPK.NF-KB, ROS, Ca2+, genes, and proteins.

Mesenchymal Stem Cells-Derived Exosomes: A Possible Therapeutic Strategy for Osteoporosis.

Osteoporosis is a common age-related disorder characterized by low bone mass and deterioration in bone microarchitecture, leading to increased skeletal fragility and fracture risk. The pathophysiology of osteoporosis is multifactorial. It is related to the imbalance between osteoblasts and osteoclasts; reduced bone mass and increased adipogenesis in the bone marrow. Moreover, angiogenesis, inflammatory process and miRNAs have shown effects in the formation of osteoporosis. In the recent years, mesenchymal stem cells (MSCs) have been regarded as an excellent choice for cell-based tissue engineering therapy of osteoporosis. Growing evidence showed that paracrine effect has been considered as the predominant mechanism for the role of MSCs in tissue repair. Recently, many studies have proposed that MSCs-derived exosomes are effective for a variety of diseases like cancer, cardiovascular diseases, etc. However, whether the MSCs-derived exosomes could serve as a novel therapeutic tool for osteoporosis has not clearly described. In this review, we summarize the MSCs-derived exosomes and the relationship with osteogenesis, osteoclast differentiation, angiogenesis, immune processes and miRNAs. Finally, we suggest that MSCs-derived exosomes might be a promising therapeutic method for osteoporosis in the future.

Hidden Blood Loss in Posterior Lumbar Fusion Surgery: An Analysis of Risk Factors.

STUDY DESIGN: Descriptive study. OBJECTIVES: This study aimed to evaluate the hidden blood loss (HBL) of patients who underwent lumbar fusion surgery for degenerative spine and to analyze its risk factors. SUMMARY OF BACKGROUND DATA: When planning transfusion strategies, blood loss calculation is important. However, in clinical practice, spine surgeons usually ignore the possibility that a large amount of HBL may occur after lumbar fusion surgery. MATERIALS AND METHODS: We studied the patients who underwent posterior lumbar fusion (PLF) surgery for degenerative spine from 2014 to 2015 in one institution. The patient's demographics, comorbid conditions, coagulation panel value, surgical time, number of levels fused, American Society of Anesthesiologists (ASA) classification, cell saver, preoperative hematocrit level, preoperative hemoglobin level, and postoperative complications were collected retrospectively. Pearson correlation analyses were used to find an association between patient characteristics and HBL. Multivariate linear analysis was used to determine independent risk factors of HBL. RESULTS: We reviewed 169 consecutive patients who underwent PLF surgery for degenerative spine in one institution. The mean amount of HBL was 588 mL, which was 39% of the total blood loss. On the basis of the model of multiple linear regression analysis, the multilevel fusion (P=0.001), surgical time (P=0.034), and fibrinogen level (P=0.027) were independent risk factors that contributed to HBL, but age of 60 years or above (P=0.110), postoperative complications (P=0.278), and cell saver were not (P=0.739). CONCLUSIONS: We conclude that a large amount of HBL may occur in patients who underwent PLF surgery for degenerative spine. In addition, significant hidden loss may have a correlation with postoperative mortality. Multilevel fused, surgical time, and fibrinogen level should be paid close attention when considering strategies of fluid infusion and blood transfusion.

PPAR-γ and Wnt Regulate the Differentiation of MSCs into Adipocytes and Osteoblasts Respectively.

BACKGROUND: Under the transcriptional control of numerous factors and intracellular signals, mesenchymal stem cells (MSCs) can differentiate into various cell types, including adipocytes and osteoblasts. However, the precise cellular signaling factors that determine the cell fate of MSCs in bone marrow remain largely unknown. OBJECTIVE: In this review, we focus on the ties of PPAR-γ and Wnt signaling in MSC differentiation into adipocytes and osteoblasts. RESULTS: Peroxisome proliferator-activated receptor-γ (PPAR-γ) is well established as a prime inducer of adipogenesis, while the Wnt pathway is regarded as the master moderator of osteogenesis. A theoretical inverse relationship exists between adipogenic and osteogenic lineage commitment and differentiation: the differentiation toward an osteoblast phenotype occurs at the expense of an adipocyte phenotype. CONCLUSION: It has been proposed that the balance between osteogenic and adipogeneic MSC differentiation is disrupted in diverse areas of human health. Therefore, understanding the ties between PPAR- γand Wnt signaling in MSC differentiation has significant implications in diverse areas of human health, from obesity to osteoporosis to regenerative medicine.

Cement Leakage in Percutaneous Vertebral Augmentation for Osteoporotic Vertebral Compression Fractures: Analysis of Risk Factors.

STUDY DESIGN: The risk factors for cement leakage were retrospectively reviewed in 192 patients who underwent percutaneous vertebral augmentation (PVA). OBJECTIVE: To discuss the factors related to the cement leakage in PVA procedure for the treatment of osteoporotic vertebral compression fractures. SUMMARY OF BACKGROUND DATA: PVA is widely applied for the treatment of osteoporotic vertebral fractures. Cement leakage is a major complication of this procedure. The risk factors for cement leakage were controversial. MATERIALS AND METHODS: A retrospective review of 192 patients who underwent PVA was conducted. The following data were recorded: age, sex, bone density, number of fractured vertebrae before surgery, number of treated vertebrae, severity of the treated vertebrae, operative approach, volume of injected bone cement, preoperative vertebral compression ratio, preoperative local kyphosis angle, intraosseous clefts, preoperative vertebral cortical bone defect, and ratio and type of cement leakage. To study the correlation between each factor and cement leakage ratio, bivariate regression analysis was employed to perform univariate analysis, whereas multivariate linear regression analysis was employed to perform multivariate analysis. RESULTS: The study included 192 patients (282 treated vertebrae), and cement leakage occurred in 100 vertebrae (35.46%). The vertebrae with preoperative cortical bone defects generally exhibited higher cement leakage ratio, and the leakage is typically type C. Vertebrae with intact cortical bones before the procedure tend to experience type S leakage. Univariate analysis showed that patient age, bone density, number of fractured vertebrae before surgery, and vertebral cortical bone were associated with cement leakage ratio (P<0.05). Multivariate analysis showed that the main factors influencing bone cement leakage are bone density and vertebral cortical bone defect, with standardized partial regression coefficients of -0.085 and 0.144, respectively. CONCLUSION: High bone density and vertebral cortical bone defect are independent risk factors associated with bone cement leakage.

Diagnostic value of enzyme-linked immunospot assay using CFP10/ESAT6 fusion protein as antigen in spinal tuberculosis.

OBJECTIVE: To establish a method of detecting spinal tuberculosis (TB) infection by enzyme-linked immunospot (ELlSPOT) assay and evaluate the value of CFP10/ESAT6 fusion protein for diagnosis of spinal TB. METHODS: Suspected spinal TB patients were prospectively recruited in two hospitals (First Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine; Nanfang Hospital, Southern Medical University) from May 2012 to December 2013. Data on clinical characteristics of the patients and conventional laboratory results were collected. Compare and analyze the positive detection rate in spinal TB diagnosis by different methods including ELISPOT detection and conventional detection methods. RESULTS: 47 patients with spinal TB had available biopsy or surgical specimens for histopathological examination and 41 specimens had pathological features consistent with a diagnosis of TB infection. Among the spinal TB patients and non-TB disease patients,the overall sensitivity, specificity, positive predictive value, and negative predictive value of the ELISPOT assay in spinal TB diagnosis were 82.7%,87.2%,89.6%, and 79.1%,respectively; the 4 indexes of the PPD skin test were 61.5%, 46.2%, 60.4%, and 47.4%, respectively;those of the antibody detection were 55.8%, 61.5%, 65.9%, and 51.1%. The positive rate of ELISPOT was significantly higher than those of PPD skin test and antibody detection test (82.7% vs. 61.5%, Χ² =5.786, P=0.016; 82.7% vs. 55.8%, Χ² =8.847, P=0.003), but not significantly different from the positive rate of pathological examination (82.7% vs. 87.2%, Χ² =0.396, P=0.529). Moderate agreement was found between pathological examination and the ELISPOT assay (87.2%, Κ=0.498, P=0.001). CONCLUSION: With high sensitivity and specificity, the ELISPOT assay using CFP10/ESAT6 fusion protein as antigen is an effective technique for auxiliary diagnosis of spinal TB.

[Clinical application of cyanoacrylates for prevention of cerebrospinal fluid leakage].

OBJECTIVE: To explore the effectiveness of cyanoacrylates (Fuaile) for spinal subdural benign tumorectomy to prevent the cerebrospinal fluid leakage. METHODS: Between January 2009 and March 2013, 35 patients underwent spinal subdural benign tumorectomy. Of 35 patients, Fuaile and gelatin sponge were used after stitch suture for a watertight closure of the dura in 19 cases (trial group), and only gelatin sponge was used after stitch suture in 16 cases (control group). There was no significant difference in gender, age, disease duration, types of tumors, and sites of tumors between 2 groups (P > 0.05). The ratio of watertight closure, incision healing, and relative complications were compared between 2 groups. RESULTS: All patients in 2 groups achieved watertight closure of the dura intraoperatively. There was no significant difference in operation time, intraoperative blood loss, length of dura incision, hospitalization time, total drainage volume, and drainage time between 2 groups (P > 0.05). Primary incision healing was obtained; no delayed healing, infection, or nerve compression occurred in all patients. At last follow-up, the ratios of successful watertight closure of trial and control groups were 89.5% (17/19) and 50.0% (8/16) respectively, showing significant difference (P=0.02). No delayed cerebrospinal fluid leakage or incision infection was found at 1 and 3 months after operation. CONCLUSION: The application of cyanoacrylates for watertight closure of dura in spinal subdural benign tumorectomy is safe and effective.

Design and finite-element evaluation of a versatile assembled lumbar interbody fusion cage.

INTRODUCTION: When an interbody cage is inserted into a human being's lumbar spine, not only the design, but also the material used is considerably crucial, particularly when minimally invasive lumbar fusion (MILIF) approaches are considered. The purpose of this study was to design a multi-function cage (either for MILIF or open lumbar interbody fusion) and also to evaluate the strength of the design based on a finite-element model analysis. METHOD: Three-dimensional finite-element models that were instrumental in the reproduction of post-operative conditions under which different cages, such as assembled lumbar interbody fusion cages (ALIFC) and the separated ones, could be examined and traced after implantation were developed. Simulations were run to realize various loading conditions including axial compression, flexion, extension, lateral bending and rotation under a constant compressive preload. Meanwhile, the evaluation results derived from FEMs data focused on endplate stress distribution, peak stress of von Mises and stress of cage. Stress distributions on the bone surface were evaluated and discussed as well. RESULTS: The consequences of cage insertion, high strains and stresses, were concentrated in the areas where the cage and endplate were in contact with each other. Simultaneously, contact stresses around the implants seemed to be concentrated around the periphery of the device. After implantation of ALIFC, the stiffness of the new cages was similar to that of traditional cages in an assemble condition, according to the biomechanical data dealing with FEM. Once a separated cage was in the place of an assembled cage, the stresses would get symmetrically distributed in the lateral areas of the endplate and decrease significantly at the center where the separated cage was not in contact with the endplate. The stress of the cage was going to be high once being rotating; most significant difference of stresses distribution due to the alternative choice has been found in the state of rotation. On comparison of peak von Mises stresses on the endplates in the new cage, the stresses were symmetrically distributed in the lateral areas of the endplate when a separated cage was used in place of an assembled cage. CONCLUSION: The new cage was more advantages with regard to endplate stress distribution, peak stress of von Mises and stress of cage than the assembled state. ALIFC can provide sufficient primary stability for lumbar intervertebral fusion and the new cage may be regarded as a suitable device for load-bearing implantation.

MicroRNA expression profile of bronchioalveolar stem cells from mouse lung.

Increasing evidence has suggested that bronchioalveolar stem cell (BASC) is the progenitor cells of lung cancer stem cells. However, the mechanisms by which self-renewal of BSACs is controlled and how BASCs turn into cancer stem cells still remains to be unknown. In the present study, we successfully isolated bronchioalveolar stem cells (BASCs) from mouse lung using FACS. These BASCs were characterized by clonal growth, self-renewal and high capacity for differentiation, suggesting that these BASCs are indeed stem cells. We investigated the microRNA (miRNA) expression profile of these BASCs using miRNA array and quantitative RT-PCR. We discovered that BASCs possessed a unique miRNA profile, with altered expression of several microRNAs, such as miR-142-3p, miR-451, miR-106a, miR-142-5p, miR-15b, miR-20a, miR-106b, miR-25, miR-486, in BASCs compared to control cells. Our results suggest that microRNAs might play important roles in maintaining the self-renewal capacity of BASCs, and suggest the intriguing possibility that aberrant expression of microRNAs could involved in turning BASCs into lung cancer stem cells.