Hmga1-overexpressing lentivirus protects against osteoporosis by activating the Wnt/ß-catenin pathway in the osteogenic differentiation of BMSCs.

Postmenopausal osteoporosis is associated with bone formation inhibition mediated by the impaired osteogenic differentiation potential of bone marrow mesenchymal stem cells (BMSCs). However, identifying and confirming the essential genes in the osteogenic differentiation of BMSCs and osteoporosis remain challenging. The study aimed at revealing the key gene that regulated osteogenic differentiation of BMSCs and led to osteoporosis, thus exploring its therapeutic effect in osteoporosis. In the present study, six essential genes related to the osteogenic differentiation of BMSCs and osteoporosis were identified, namely, fibrillin 2 (Fbn2), leucine-rich repeat-containing 17 (Lrrc17), heat shock protein b7 (Hspb7), high mobility group AT-hook 1 (Hmga1), nexilin F-actin-binding protein (Nexn), and endothelial cell-specific molecule 1 (Esm1). Furthermore, the in vivo and in vitro experiments showed that Hmga1 expression was increased during the osteogenic differentiation of rat BMSCs, while Hmga1 expression was decreased in the bone tissue of ovariectomized (OVX) rats. Moreover, the expression of osteogenic differentiation-related genes, the activity of alkaline phosphatase (ALP), and the number of mineralized nodules were increased after Hmga1 overexpression, which was partially reversed by a Wnt signaling inhibitor (DKK1). In addition, after injecting Hmga1-overexpressing lentivirus into the bone marrow cavity of OVX rats, the bone loss, and osteogenic differentiation inhibition of BMSCs in OVX rats were partially reversed, while osteoclast differentiation promotion of BMSCs in OVX rats was unaffected. Taken together, the present study confirms that Hmga1 prevents OVX-induced bone loss by the Wnt signaling pathway and reveals that Hmga1 is a potential gene therapeutic target for postmenopausal osteoporosis.

Anticancer activity of Fisetin against the human osteosarcoma cell lines involves G2/M cell cycle arrest, mitochondrial apoptosis and inhibition of cell migration and invasion.

Retraction of: 'Anticancer activity of Fisetin against the human osteosarcoma cell lines involves G2/M cell cycle arrest, mitochondrial apoptosis and inhibition of cell migration and invasion', by Chunyang Xing, Yuzhu Zhang, Rong Su, Ronghuan Wu JBUON 2019;25(2):1022-1027; PMID:32521901. Following the publication of the above article, readers drew to our attention that part of the data was unreliable. The authors were requested to provide the raw data to prove the originality, but were unable to do so. After an investigation, the Editors of JBUON decided to retract this article. We thank the readers for bringing this matter to our attention. We apologize for any inconvenience it may cause.

Large fuzzy biodegradable polyester microspheres with dopamine deposition enhance cell adhesion and bone regeneration in vivo.

The biodegradable polymer microparticles with different surface morphology and chemical compositions may influence significantly the behaviors of cells, and thereby further the performance of tissue regeneration in vivo. In this study, multi-stage hierarchical textures of poly(D,L-lactic-co-glycolide) (PLGA)/PLGA-b-PEG (poly(ethylene glycol)) microspheres with a diameter as large as 50-100 µm are fabricated based on interfacial instability of an emulsion. The obtained fuzzy structures on the microspheres are sensitive to annealing, which are changed gradually to a smooth one after treatment at 37 °C for 6 d or 80 °C for 1 h. The surface microstructures that are chemically dominated by PEG can be stabilized against annealing by dopamine deposition. By the combination use of annealing and dopamine deposition, a series of microspheres with robust surface topologies are facilely prepared. The fuzzy microstructures and dopamine deposition show a synergetic role to enhance cell-material interaction, leading to a larger number of adherent bone marrow-derived mesenchymal stem cells (BMSCs), A549 and MC 3T3 cells. The fuzzy microspheres with dopamine deposition can significantly promote bone regeneration 12 w post surgery in vivo, as revealed by micro-CT, histological, western blotting and RT-PCR analyses.

Rational design of nonstoichiometric bioceramic scaffolds via digital light processing: tuning chemical composition and pore geometry evaluation.

Bioactive ceramics are promising candidates as 3D porous substrates for bone repair in bone regenerative medicine. However, they are often inefficient in clinical applications due to mismatching mechanical properties and compromised biological performances. Herein, the additional Sr dopant is hypothesized to readily adjust the mechanical and biodegradable properties of the dilute Mg-doped wollastonite bioceramic scaffolds with different pore geometries (cylindrical-, cubic-, gyroid-) by ceramic stereolithography. The results indicate that the compressive strength of Mg/Sr co-doped bioceramic scaffolds could be tuned simultaneously by the Sr dopant and pore geometry. The cylindrical-pore scaffolds exhibit strength decay with increasing Sr content, whereas the gyroid-pore scaffolds show increasing strength and Young's modulus as the Sr concentration is increased from 0 to 5%. The ion release could also be adjusted by pore geometry in Tris buffer, and the high Sr content may trigger a faster scaffold bio-dissolution. These results demonstrate that the mechanical strengths of the bioceramic scaffolds can be controlled from the point at which their porous structures are designed. Moreover, scaffold bio-dissolution can be tuned by pore geometry and doping foreign ions. It is reasonable to consider the nonstoichiometric bioceramic scaffolds are promising for bone regeneration, especially when dealing with pathological bone defects.

Bone tissue regeneration: The role of finely tuned pore architecture of bioactive scaffolds before clinical translation.

Spatial dimension of pores and interconnection in macroporous scaffolds is of particular importance in facilitating endogenous cell migration and bone tissue ingrowth. However, it is still a challenge to widely tune structure parameters of scaffolds by conventional methods because of inevitable pore geometrical deformation and poor pore interconnectivity. Here, the long-term in vivo biological performances of nonstoichiometric bioceramic scaffolds with different pore dimensions were assessed in critical-size femoral bone defect model. The 6% Mg-substituted wollastonite (CSi-Mg6) powders were prepared via wet-chemical precipitation and the scaffolds elaborately printed by ceramic stereolithography, displaying designed constant pore strut and tailorable pore height (200, 320, 450, 600 µm), were investigated thoroughly in the bone regeneration process. Together with detailed structural stability and mechanical properties were collaboratively outlined. Both µCT and histological analyses indicated that bone tissue ingrowth was retarded in 200 µm scaffolds in the whole stage (2-16 weeks) but the 320 µm scaffolds showed appreciable bone tissue in the center of porous constructs at 6-10 weeks and matured bone tissue were uniformly invaded in the whole pore networks at 16 weeks. Interestingly, the neo-tissue ingrowth was facilitated in the 450 µm and 600 µm scaffolds after 2 weeks and higher extent of bone regeneration and remodeling at the later stage. These new findings provide critical information on how engineered porous architecture impact bone regeneration in vivo. Simultaneously, this study shows important implications for optimizing the porous scaffolds design by advanced additive manufacture technique to match the clinical translation with high performance.

Anticancer activity of Fisetin against the human osteosarcoma cell lines involves G2/M cell cycle arrest, mitochondrial apoptosis and inhibition of cell migration and invasion.

PURPOSE: Osteosarcoma is rare but fatal type of human malignancy. The high metastasis rate, late diagnosis, emergence of drug resistance against drugs such as doxorubicin, and the lack of therapeutic targets obstructs the treatment of osteosarcoma. The present investigation explores the anticancer properties of Fisetin against human osteosarcoma cells. METHODS: The cell viability was determined by WST-1 assay. DAPI and Annexin V/propidium iodide (PI) assays were used for detection of apoptosis. Flow cytometry was used for the determination of osteosarcoma MG-63 cell distribution. Wound healing and transwell assays were used for cell migration and invasion. Western blotting was used for protein expression analysis. RESULTS: The results showed that Fisetin inhibits the growth of the MG-63 cells in a dose-dependent manner. Fisetin showed an IC50 of 18 µM against the MG-63 cells. The growth inhibitory effects of Fisetin were mainly due to induction of apoptosis which was accompanied by enhancement of the capsase-3 and Bax and depletion of Bcl-2 expression. Fisetin treatment increased reactive oxygen species (ROS) from 100 in untreated to 220% at 36 µM and decreased mitochondrial membrane potential (MMP) levels from 100 in untreated to 21% at 36 µM. Fisetin also induced G2/M cell cycle arrest of the MG-63 cells and suppressed the expression of cyclin-B1. The wound healing and the transwell assay showed that Fisetin suppressed the migration and invasion of the MG-63 cells. CONCLUSION: Taken together, Fisetin may find use as lead molecule in the osteosarcoma therapeutic development programmes.

Seasonal variation and correlation analysis of vitamin D and parathyroid hormone in Hangzhou, Southeast China.

This study aimed to describe the 25-hydroxyvitamin D (25(OH)D) and parathyroid hormone (PTH) status of Southeast Chinese individuals influenced by season. The secondary aim was to determine the cutoff for sufficient 25(OH)D in a four-season region. From January 2011 to June 2014, a total of 17 646 individuals were evaluated in our study. The serum levels of PTH were detected simultaneously in 5579 cases. A total of 25(OH)D and intact PTH were measured by the electrochemiluminescent immunoassay. The distribution of the concentration, prevalence and seasonal variability of 25(OH)D and PTH were studied. The mean 25(OH)D concentration in our study was 43.00(30.40) nmol/L. The prevalence of insufficiency (25(OH)D < 50 nmol/L) was 62.87% and that of deficiency (<30 nmol/L) was 28.54%. Mean serum 25(OH)D levels revealed a limited sinusoidal profile throughout the year and were significantly higher in Autumn. On the other hand, PTH levels showed an opposite response to seasonal effects relative to 25(OH)D. Age, BMI and daylight were not significantly correlated with 25(OH)D and serum PTH reached a plateau at higher values of serum 25(OH)D of 42.86 nmol/L. This study demonstrated that Vitamin D insufficiency is highly prevalent in Southeast China. The concentration of 25(OH)D in the male group was generally higher than that in the female group. Seasonal variation was an important aspect of 25(OH)D and PTH concentration. This study revealed that the optimal serum threshold of 25(OH)D for bone health should be between 40 and 50 nmol/L for Southeast Chinese individuals.

Effect of Foreign Ion Substitution and Micropore Tuning in Robocasting Single-Phase Bioceramic Scaffolds on the Physicochemical Property and Vascularization.

The inorganic powder slurry extrusion printing technique known as robocasting is an interesting method to fabricate complex porous architectures whereby feedstocks containing organic binders and powders are printed and the resulting scaffolds are subjected to sintering. A major limiting factor of this technique is the simultaneous tailoring of vascularization efficacy and osteogenic activity, usually done by adding the secondary phase in the organic slurry before the writing step. Mechanical mixing of biphasic powders is required to avoid compromising the biological performance and physical defects caused by significantly different physicochemical properties. This study addresses this issue by developing a selective ion doping and microstructure tuning for the production of bioceramic scaffolds with a binozzle robocasting process. Different metal ions (Sr2+, Mg2+) were doped into wollastonite (CaSiO3; CSi) powders considering the mechanical stability and bioactive enhancement of the bioceramic scaffolds. Subsequently, the Mg-doped CSi slurries were used as shell-nozzle feedstocks added with 5, 10, and 15 µm diameter polystyrene microbeads that allowed shell-layer micropore production in pore struts during sintering. Finally, the most promising pore-strut microstructures and mechanical evolution of scaffolds were evaluated, and especially the enhanced fibrovascularization potential was confirmed in dorsal muscle embedding model in rabbits. This study may open an avenue to designing multiproperty-tuned macro- and microporous bioceramics for bone regenerative medicine, especially in challenging bone defect conditions.

Nonstoichiometric wollastonite bioceramic scaffolds with core-shell pore struts and adjustable mechanical and biodegradable properties.

Controllable mechanical strength and biodegradation of bioceramic scaffolds is a great challenge to treat the load-bearing bone defects. Herein a new strategy has been developed to fabricate porous bioceramic scaffolds with adjustable component distributions based on varying the core-shell-structured nozzles in three-dimensional (3D) direct ink writing platform. The porous bioceramic scaffolds composed of different nonstoichiometic calcium silicate (nCSi) with 0%, 4% or 10% of magnesium-substituting-calcium ratio (CSi, CSi-Mg4, CSi-Mg10) was fabricated. Beyond the mechanically mixed composite scaffolds, varying the different nCSi slurries through the coaxially aligned bilayer nozzle makes it easy to create core-shell bilayer bioceramic filaments and better control of the different nCSi distribution in pore strut after sintering. It was evident that the magnesium substitution in CSi contributed to the increase of compressive strength for the single-phasic scaffolds from 11.2 MPa (CSi), to 39.4 MPa (CSi-Mg4) and 80 MPa (CSi-Mg10). The nCSi distribution in pore struts in the series of core-shell-strut scaffolds could significantly adjust the strength [e.g. CSi@CSi-Mg10 (58.9 MPa) vs CSi-Mg10@CSi (30.4 MPa)] and biodegradation ratio in Tris buffer for a long time stage (6 weeks). These findings demonstrate that the nCSi components with different distributions in core or shell layer of pore struts lead to tunable strength and biodegradation inside their interconnected macropore architectures of the scaffolds. It is possibly helpful to develop new bioactive scaffolds for time-dependent tailoring mechanical and biological performances to significantly enhance bone regeneration and repair applications, especially in some load-bearing bone defects.

Apoptotic effect of pyrroloquinoline quinone on chondrosarcoma cells through activation of the mitochondrial caspase­dependent and caspase­independent pathways.

Chondrosarcomas are malignant tumors of the bone that exhibit resistance to chemotherapy and radiation. Pyrroloquinoline quinone (PQQ) is a bacterial redox co­factor and antioxidant that has been found to induce apoptosis in various cancer cells. This study investigated the role of PQQ in cell apoptosis of chondrosarcoma cells and the underlying pathways involved. We confirmed that PQQ was cytotoxic to chondrosarcoma SW1353 cells by a cell cytotoxicity assay. Furthermore, flow cytometry showed that the number of apoptotic cells increased in a concentration­dependent and time­dependent manner following PQQ treatment, but this effect was not significant in normal cells. Co­immunoprecipitation assays showed that the binding of Smac to X­linked inhibitor­of­apoptosis protein (XIAP) was significantly increased and the binding of XIAP with caspase­3 was significantly decreased following PQQ treatment. This was accompanied by a decrease in the levels of caspase­1 and procaspase­3, as demonstrated by western blot analysis. Western blotting also showed that the level of cytochrome c in the mitochondria was decreased and its level in the cytoplasm was increased. These findings indicate the role of caspase­dependent apoptotic pathways in the effect of PQQ. Furthermore, the cytoplasmic and nuclear levels of apoptosis­inducing factor (AIF) were increased and its mitochondrial levels were decreased, and similar results were obtained for endonuclease G. Thus, the role of caspase­independent pathways was also demonstrated. Finally, in vivo tumor implantation experiments showed that PQQ was able to inhibit tumor growth in mice with chondrosarcoma. These findings demonstrated that PQQ induced apoptosis in human chondrosarcoma cells by activating mitochondrial caspase­dependent and caspase­independent pathways. Thus, the proteins involved in these pathways may have potential as antitumor treatment targets for chondrosarcoma.

Injection of synthetic mesenchymal stem cell mitigates osteoporosis in rats after ovariectomy.

Osteoporosis is a severe skeletal disorder. Patients have a low bone mineral density and bone structural deterioration. Mounting lines of evidence suggest that inappropriate apoptosis of osteoblasts/osteocytes leads to maladaptive bone remodelling in osteoporosis. It has been suggested that transplantation of stem cells, including mesenchymal stem cells, may alter the trajectory of bone remoulding and mitigate osteoporosis in animal models. However, stem cells needed to be carefully stored and characterized before usage. In addition, there is great batch-to-batch variation in stem cell production. Here, we fabricated therapeutic polymer microparticles from the secretome and membranes of mesenchymal stem cells (MSCs). These synthetic MSCs contain growth factors secreted by MSCs. In addition, these particles display MSC surface molecules. In vitro, co-culture with synthetic MSCs increases the viability of osteoblast cells. In a rat model of ovariectomy-induced osteoporosis, injection of synthetic MSCs mitigated osteoporosis by reducing cell apoptosis and systemic inflammation, but increasing osteoblast numbers. Synthetic MSC offers a promising therapy to manage osteoporosis.

Acamprosate Protects Against Adjuvant-Induced Arthritis in Rats via Blocking the ERK/MAPK and NF-κB Signaling Pathway.

Osteoarthritis is a type of joint disease that results from the breakdown of joint cartilage and underlying bone and is believed to be caused by mechanical stress on the joint and low-grade inflammatory processes. Acamprosate significantly ameliorates the pathological features of experimental autoimmune encephalomyelitis due to its anti-inflammatory effect. The aims of the present study were to investigate the anti-arthritis activities of acamprosate and elucidate the underlying mechanisms. Adjuvant-induced arthritis (AIA) was induced by intradermal injection of complete Freund's adjuvant. Male Wistar rats were randomly divided into five groups: (1) sham control group, (2) AIA group, (3) acamprosate 10 mg/kg (AIA + ACA10), (4) acamprosate 30 mg/kg (AIA + ACA30), and (5) acamprosate 100 mg/kg (AIA + ACA100). Paw swelling and the arthritis index were measured, and the production of IL-1ß, IL-6, and TNF-α was detected by ELISA in serum. The expression of inflammation-related molecules, including c-Raf, ERK1/2, and NF-κB, was determined by Western blotting. We found that acamprosate significantly suppressed paw swelling and the arthritis index in AIA rats. Moreover, acamprosate also significantly suppressed the production of TNF-α, IL-1ß, and IL-6 in serum, which is elevated by AIA induction. Finally, acamprosate inhibited p-c-Raf and p-ERK1/2 and NF-κB activation after AIA treatment. These results indicate that acamprosate has an anti-inflammatory effect on adjuvant-induced arthritic rats via inhibiting the ERK/MAPK and NF-κB signaling pathways, and acamprosate may serve as a promising novel therapeutic agent for osteoarthritis.

Diagnosis and treatment of spinal tuberculosis after liver transplantation.

BACKGROUND: Spinal tuberculosis is a common disease in orthopedic clinical practice; however, it is seldom reported after organ transplantation. The aim of this study was to investigate the diagnosis and treatment of spinal tuberculosis after organ transplantation. METHOD: Two cases were diagnosed as spinal tuberculosis after liver transplantation and were treated with socarboxazide, rifampicin, streptomycin and ethambutol for more than one year. RESULTS: After treatment with anti-tuberculosis drugs for several months, the symptoms of both patients clearly improved. Back pain disappeared, and erythrocyte sedimentation and body temperature returned to normal. CONCLUSIONS: We should highly suspect spinal tuberculosis if notalgia and night sweats are present after organ transplantation. Anti-tuberculosis therapy is an effective treatment for spinal tuberculosis after organ transplantation.