Establishment and characterization of a rat model of scalp-cranial composite defect for multilayered tissue engineering.

Composite cranial defects have individual functional and aesthetic ramifications, as well as societal burden, while posing significant challenges for reconstructive surgeons. Single-stage composite reconstruction of these deformities entail complex surgeries that bear many short- and long-term risks and complications. Current research on composite scalp-cranial defects is sparse and one-dimensional, often focusing solely on bone or skin. Thus, there is an unmet need for a simple, clinically relevant composite defect model in rodents, where there is a challenge in averting healing of the skin component via secondary intention. By utilizing a customizable (3D-printed) wound obturator, the scalp wound can be rendered non-healing for a long period (more than 6 weeks), with the cranial defect patent. The wound obturator shows minimal biotoxicity and will not cause severe endocranium-granulation adhesion. This composite defect model effectively slowed the scalp healing process and preserved the cranial defect, embodying the characteristics of a "chronic composite defect". In parallel, an autologous reconstruction model was established as the positive control. This positive control exhibited reproducible healing of the skin within 3 weeks with variable degrees of osseointegration, consistent with clinical practice. Both models provide a stable platform for subsequent research not only for composite tissue engineering and scaffold design but also for mechanistic studies of composite tissue healing.

GAPDH suppresses adenovirus-induced oxidative stress and enables a superfast production of recombinant adenovirus.

Recombinant adenovirus (rAdV) is a commonly used vector system for gene transfer. Efficient initial packaging and subsequent production of rAdV remains time-consuming and labor-intensive, possibly attributable to rAdV infection-associated oxidative stress and reactive oxygen species (ROS) production. Here, we show that exogenous GAPDH expression mitigates adenovirus-induced ROS-associated apoptosis in HEK293 cells, and expedites adenovirus production. By stably overexpressing GAPDH in HEK293 (293G) and 293pTP (293GP) cells, respectively, we demonstrated that rAdV-induced ROS production and cell apoptosis were significantly suppressed in 293G and 293GP cells. Transfection of 293G cells with adenoviral plasmid pAd-G2Luc yielded much higher titers of Ad-G2Luc at day 7 than that in HEK293 cells. Similarly, Ad-G2Luc was amplified more efficiently in 293G than in HEK293 cells. We further showed that transfection of 293GP cells with pAd-G2Luc produced much higher titers of Ad-G2Luc at day 5 than that of 293pTP cells. 293GP cells amplified the Ad-G2Luc much more efficiently than 293pTP cells, indicating that exogenous GAPDH can further augment pTP-enhanced adenovirus production. These results demonstrate that exogenous GAPDH can effectively suppress adenovirus-induced ROS and thus accelerate adenovirus production. Therefore, the engineered 293GP cells represent a superfast rAdV production system for adenovirus-based gene transfer and gene therapy.

Treatment of bone-cartilage defects with dual-layer tissue-engineered scaffolds loaded with icariin and quercetin.

Over the past few decades, significant research has been conducted on tissue-engineered constructs for cartilage repair. However, there is a growing interest in addressing subchondral bone repair along with cartilage regeneration. This study focuses on a bilayer tissue engineering scaffold loaded with icariin (ICA) and quercetin (QU) for simultaneous treatment of knee joint cartilage and subchondral bone defects. The cytotoxicity of dual-layer scaffolds loaded with ICA and QU was assessed through live/dead cell staining. Subsequently, these dual-layer scaffolds loaded with ICA and QU were implanted into cartilage and subchondral bone defects in Sprague-Dawley (SD) rats. The repair effects were evaluated through macroscopic observation, computed tomography, and immunohistochemistry. After 12 weeks of implantation of dual-layer scaffolds loaded with ICA and QU into the cartilage and bone defects of SD rats, better repair effects were observed in both cartilage and bone defects compared to the blank control group. We found that the dual-layer tissue-engineered scaffold loaded with ICA and QU had excellent biocompatibility and could effectively repair articular cartilage and subchondral bone injuries, showing promising prospects for clinical applications.

Identifying immune-related prognostic biomarkers in osteosarcoma: Development and validation of the tumor immune microenvironment risk model based on analysis of TCGA.

OBJECTIVE: Osteosarcoma is a rare and aggressive malignancy with limited effective therapeutic options. This study aimed to identify immune-related prognostic biomarkers and develop a prognostic model for osteosarcoma. METHODS: We performed integrated analysis of transcriptomic data and immune cell infiltration profiles of 84 osteosarcoma samples from the Cancer Genome Atlas (TCGA) database. Time-dependent receiver operating characteristic (ROC) curve analysis was used to assess the prognostic value of the TIMErisk model. We also performed functional annotation and pathway enrichment analyses to explore the potential mechanisms underlying the TIMErisk model. RESULTS: We identified a seven-gene TIMErisk model (C2, APBB1IP, BST2, TRPV2, CCL5, GBP1, and F13A1) that was independently associated with overall survival of osteosarcoma patients. The TIMErisk model showed significant associations with immune cell infiltration and immunosuppressive gene expression. In addition, the TIMErisk model was associated with drug sensitivity, and we found that several immune checkpoint genes were significantly differentially expressed between high- and low-TIMErisk groups. Functional annotation and pathway enrichment analyses revealed that the TIMErisk model was associated with multiple immune-related pathways, including antigen processing and presentation, cytokine-cytokine receptor interaction, and T cell receptor signaling pathway. CONCLUSION: Our study identified a novel TIME-based prognostic model for osteosarcoma that incorporates immune-related genes and can be used to predict patient prognosis and response to immunotherapy. Our findings highlight the importance of the TIME microenvironment in osteosarcoma progression and suggest that immune-related biomarkers may have clinical significance in the management of osteosarcoma.

[Experimental study on transplantation of microencapsulated transgenic bone marrow mesenchymal stem cells for early steroid-induced osteonecrosis of femoral head in rabbits].

OBJECTIVE: To investigate the effect of microencapsulated transgenic bone marrow mesenchymal stem cells (BMSCs) transplantation on early steroid induced osteonecrosis of femoral head (SONFH) in rabbits. METHODS: Alginate poly- L-lysine-sodium alginate (APA) microencapsulated transgenic BMSCs with high expression of Foxc2 were prepared by high-voltage electrostatic method. Part of the cells were cultured in osteoblasts and observed by alizarin red staining at 2 and 3 weeks. Forty New Zealand white rabbits were used to prepare SONFH models by using hormone and endotoxin. Thirty two rabbits who were successful modeling were screened out by MRI and randomly divided into 4 groups (groups A, B, C and D, n=8); another 6 normal rabbits were taken as normal control (group E). The rabbits in group A did not receive any treatment; and in groups B, C, and D were injected with normal saline, allogeneic BMSCs, and APA microencapsulated transgenic BMSCs respectively after core decompression. At 6 and 12 weeks after operation, specimens of femoral head were taken for HE staining to observe bone ingrowth; the expressions of osteocalcin (OCN), peroxisome proliferative activated receptor γ 2 (PPARγ-2), and vascular endothelial growth factor (VEGF) proteins were observed by immunohistochemistry staining. At 12 weeks after operation, the bone microstructure was observed by transmission electron microscope, and the maximum compressive strength and average elastic modulus of cancellous bone and subchondral bone were measured by biomechanics. RESULTS: After 2 and 3 weeks of induction culture, alizarin red staining showed the formation of calcium nodules, and the number of calcium nodules increased at 3 weeks when compared with 2 weeks. The rabbits in each group survived until the experiment was completed. Compared with groups A, B, and C, the trabeculae of group D were more orderly, the empty bone lacunae were less, there were abundant functional organelles, and obvious osteogenesis was observed, and the necrotic area was completely repaired at 12 weeks. Immunohistochemical staining showed that, at 6 and 12 weeks after operation, the expressions of OCN and VEGF in groups A, B, and C were significantly lower than those in groups D and E, while those in groups B and C were significantly higher than those in group A, and in group E than in group D ( P<0.05). The expression of PPARγ-2 was significantly higher in groups A, B, and C than in groups D and E, and in group A than in groups B and C, and in group D than in group E ( P<0.05). At 12 weeks after operation, biomechanical test showed that the average elastic modulus and maximum compressive strength of cancellous bone and subchondral bone in groups D and E were significantly higher than those in groups A, B, and C ( P<0.05); there was no significant difference between groups A, B, and C and between groups D and E ( P>0.05). CONCLUSION: In vivo transplantation of microencapsulated transgenic BMSCs can repair early SONFH in rabbits.

[Experimental study on the inhibition of Formononetin on the differentiation of osteoclasts induced by RANKL].

OBJECTIVE: To establish the in vitro study model of osteoclasts induced by RANKL, to elaborate the effect of formononetin (FO) , an effective component of Caulis Spatholobi, on the differentiation and function of bone marrow mononuclear macrophages (BMMs) into osteoclasts, and to explore the molecular mechanism of its inhibition. METHODS: The BMMs in femur and tibia were isolated from 20 clean C57/BL6 mice of 4 to 6 weeks old, 10 males and 10 females, each weighing (20± 2) g. The BMMs in femur and tibia were cultured and proliferated in vitro with α-MEM medium. BMMs were cultured with MCSF and different concentrations of anthocyanin (5 to 50 µm) respectively for 4 days, and CCK8 of cell proliferation and toxicity was detected. BMMs in good growth condition were added to M-CSF and RANKL to induce osteoclast differentiation in turn. There was no special treatment in the control group. DMSO was added to the control group with DMSO solvent. Each observation group was added with different concentrations of awnasin (1 to 20 µm) . After 6 days of culture, the osteoclasts were counted and statistically analyzed. The expression of NFATc1, c-Fos and ERK, the key transcription factors in osteoclast differentiation, were detected by Western blot, RNA was extracted at 4 days, and the activity of ctsk, trap, MMP9 and Car2 were detected by real time PCR. RESULTS: CCK8 test results showed that awnstein could inhibit the activity of BMMs in a dose-dependent manner, and had no significant toxic effect on the growth of bmms within the safe concentration range of ≤20 µM (P= 0.278>0.05) . The results of trap staining showed that awnstein could inhibit osteoclast production in a dose-dependent manner in the concentration range of (1 to 20 µM) , especially in 10 µM (P=0.000<0.05) . Western blot showed that 10 µ m could significantly inhibit the expression of NFATc1 and c-Fos, but not the expression of ERK. In terms of osteoclast function, the expression of ctsk (P=0.000<0.05) , trap (P=0.000<0.05) , MMP9 (P=0.000<0.05) and Car2 (P=0.000<0.05) related to osteoclast function were detected by real time PCR. CONCLUSION: The effective component of Caulis Spatholobi can inhibit the proliferation and differentiation of primary mononuclear macrophages into osteoclasts, and down regulate the expression of osteoclast bone resorption related proteins and genes, which may be one of the mechanisms of its prevention and treatment of bone destruction and collapse in osteonecrosis of femoral head.

Therapeutic effect of Resveratrol in the treatment of osteoarthritis via the MALAT1/miR-9/NF-κB signaling pathway.

The aim of the current study was to explore the role of Resveratrol (Res) in osteoarthritis (OA) and its underlying mechanism. Reverse transcription-quantitative polymerase chain reaction and western blot analysis were used to determine the relative expression levels of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), microRNA-9 (miR-9), nuclear factor kappa B subunit 1 (NF-κB1), interleukin (IL)-6, matrix metallopeptidase 13 (MMP-13) and caspase-3 in vitro and in the in vivo model of OA, as well as examining the effect of Res on MALAT1, miR-9 and NF-κB1, IL-6, MMP-13 and caspase-3 expression levels. Immunohistochemical analysis was performed to examine NF-κB1 and MMP-13 protein levels in the in vivo model of OA. Dual-luciferase reporter assays were used to confirm the regulatory relationship between miR-9 and MALAT1 and NF-κB1, as well as examining the effect of Res on the transcriptional activation of MALAT1 promoter. Furthermore, the effect of Res on cell proliferation in vitro was examined by MTT assay. The relative mRNA expression levels of MALAT1 and NF-κB1 were significantly increased, while miR-9 expression was significantly decreased in the OA group compared with the sham group. Treatment with Res partially reversed the effects of OA on MALAT1, NF-κB1 and miR-9 expression. Similarly, the relative protein expression levels of NF-κB1, IL-6, MMP-13 and caspase-3 were significantly increased in the OA group compared with the sham group; however, treatment with Res partially reversed the effects of OA on the protein expression levels of NF-κB1, IL-6, MMP-13 and caspase-3. MALAT1 and NF-κB1 were identified as potential target genes of miR-9, and dual-luciferase assays were used to examine the effect of miR-9 on the luciferase activity of 3'UTR MALAT1 and NF-κB1. Treatment with Res suppressed the transcriptional activation of the MALAT1 promoter, thereby inhibiting MALAT1 expression. Additionally, the relative expression level of miR-9 significantly increased following treatment with Res in a dose-dependent manner, while the relative protein expression levels of NF-κB1, IL-6, MMP-13 and caspase-3 significantly decreased following treatment with Res compared with the control. Furthermore, treatment with Res significantly increased the growth rate of chondrocytes in a dose-dependent manner compared with the control. Taken together, these results suggest that direct targeting of the MALAT1/miR-9/NF-κB1/IL-6, MMP-13/caspase-3 axis may be a novel therapeutic strategy for the treatment of OA.

[ROLE OF FORKHEAD/FOX TRANSCRIPTION FACTOR 2 OVER-EXPRESSION IN REGULATING OSTEOGENIC DIFFERENTIATION OF BONE MARROW MESENCHYMAL STEM CELLS BY Wnt SIGNALING PATHWAYS].

OBJECTIVE: To investigate the role of the forkhead/Fox transcription factor 2 (Foxc2) over-expression in regulating osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) by Wnt-ß-catenin signaling pathways in vitro so as to provide the experimental basis for repairing osteonecrosis of the femoral head. METHODS: The recombinant lentivirus carrying green fluorescent protein (group A) or Foxc2 (group B) were used to transfect the fifth generation rabbit BMSCs, and untransfected BMSCs served as a control (group C). The cell viability was measured with water soluble tetrazolium-1 (WST-1) regent at 72 hours after transfection. After 2 weeks of transfection, the expression of ß-catenin in BMSCs was detected by real time fluorescence quantitative PCR, Western blot, and immunofluorescence staining. Meanwhile, the ß-catenin inhibitors XAV-939 (0, 0.1, and 1.0 µmol/L) was added in group B; at 2 weeks after osteogenic and adipogenic induction, the gene and protein expressions of collagen type I (COL I), osteocalcin (OCN), and peroxisome proliferator activated receptor gamma 2 (PPARγ-2) were detected by real time PCR and Western blot. RESULTS: WST-1 results showed that the cell viability of group B (130.85%±0.15%) was significantly higher than that of group A (100.45%±0.35%) (t=7.500, P=0.004) at 72 hours after transfection. At 2 weeks after transfection, the gene and protein expressions of ß-catenin in group B were significantly higher than those in group A (P<0.01). After XAV-939 was added in group B, the mRNA and protein expressions of OCN and COL I gradually decreased; the mRNA and protein expressions of PPARγ-2 significantly increased (P<0.05), showing a dose-dependent manner. CONCLUSIONS: The over-expression of Foxc2 gene in BMSCs may promote osteogenic differentiation by Wnt-ß-catenin signaling pathway.

[Effects of Jisuikang on Nogo-NgR gene expression in spinal cord rats with injury].

OBJECTIVE: To study the effects of Jisuikang (Chinese characters) on Nogo-NgR gene expression, and to explore the protective effects and mechanism of Jisuikang (Chinese characters) on spinal cord injury in rats. METHODS: One hundred eighty female rats were randomly assigned to 6 groups(30 rats per group). Sham group: T10 lamina was resected only and spinal cord was untreated. Model group: spine cord injury (SCI) was created with a modified impinger of Allen's by impacting on the T10 spinal cord. Prednisolone group: Prednisolone (0.06 g/kg) was given by intragastric administration at a time interval of 24 hours after operation. The Jisuikang (Chinese characters) high, moderate and low dose groups: Jisuikang (Chinese characters) was supplied with different dose (50 g/kg, 25 g/kg, 12.5 g/kg) by intragastric administration in rats after operation,for the first time at 30 min after surgery. Animals were killed 3, 7, 14 days after surgery. The expression levels of Nogo-A and NgR were observed by Western Blot and Real-time PCR. RESULTS: The expression of Nogo-A and NgR was at the basic level at all time points in sham group. Compared with model group, the protein expression levels of Nogo-A and NgR in sham, prednisolone, Jisuikang (Chinese characters) moderate dose groups were statistically significant at all time points (P < 0.05). No difference was found in Jisuikang (Chinese characters) high and low dose groups (P > 0.05). Three days after surgery, the mRNA levels of Nogo-A and NgR in treatment group were significantly lower than that in model group (P < 0.01); 7 days after surgery,Nogo-A and NgR mRNA expression were dramatically upregulated and peaked; 14 days after operation, the expression was decreased, but still significantly higher than that in other treatment groups (P < 0.01). Prednisolone and Jisuikang (Chinese characters) moderate dose groups showed the most significant effects among all groups,but there was no statistically significant difference between two groups (P > 0.05). CONCLUSION: The decoction Jisuikang (Chinese characters) can promote the nerve cell regeneration by regulating Nogo-A and NgR gene expression, activating Nogo- NgR signaling pathways after acute spinal cord injury.

[Case-control study on effects of external fixation combined with limited internal fixation for the treatment of Pilon fractures of Rüedi-Allgower type III].

OBJECTIVE: To analyze the effects of three surgical operations in the treatment of Pilon fracture of Rüedi-Allgower type III, and put forward the best therapeutic method. METHODS: The clinical data of 33 patients with Pilon fracture who received surgical operations (plaster immobilization group, 10 cases; distal tibia anatomical plate group, 11 cases; external fixation with limited internal fixation group, 12 cases) from October 2009 to January 2012 were analyzed. There were 5 males and 5 females, ranging in age from 24 to 61 years in the plaster immobilization group. There were 7 males and 4 females, ranging in age from 21 to 64 years in the distal tibia anatomical plate group. There were 7 males and 5 females, ranging in age from 23 to 67 years in the external fixation with limited internal fixation group. The Ankle X-ray of Pilon fracture after operation, ankle score, early and late complications were collected. Bourne system was used to evaluate ankle joint function. RESULTS: After 8 months to 3 years follow-up, it was found that three kinds of treatment had significant differences in the outcomes and complications (P < 0.05): the external fixation with limited internal fixation group got the best results. The number of anatomic reduction cases in the external fixation with limited internal fixation group (7 cases) and the distal tibia anatomical plate group (8 cases) was more than the plaster immobilization group (2 cases). According to the ankle score, 8 patients got an excellent result, 3 good and 1 poor in the limited internal fixation group ,which was better than those of distal tibia anatomical plate group (5 excellent, 4 good and 2 poor) and the plaster immobilization group (3 excellent, 4 good and 3 poor). The number of early and late complications in the external fixation with limited internal fixation group was more than those in the plaster immobilization group and the distal tibia anatomical plate group (P< 0.05). CONCLUSION: Treatment of external fixation with limited internal fixation in the treatment of Pilon fracture of Rüedi-Allgower type III is effective and safe.

Immune response associated with Toll-like receptor 4 signaling pathway leads to steroid-induced femoral head osteonecrosis.

BACKGROUND: Femoral head osteonecrosis is frequently observed in patients treated with excessive corticosteroids. The objective of the current study was to establish a rat model to investigate the disruption of immune response in steroid-induced femoral head osteonecrosis via Toll-like receptor 4 (TLR4) signaling pathway. METHODS: Male SD rats were divided into the treatment group (group A) and the model group (group B) consisting of 24 rats each, and were injected intramuscularly with 20 mg/kg methylprednisolone (MP) for 8 weeks, once a week. The rats in group A were injected intravenously with 7.5 mg/kg TAK242 before each MP administration. A control group (group N) consisted of 12 rats were received saline injection. All animals were sacrificed 8, 10 and 12 weeks from the first MP injection, respectively. Histopathological analysis was performed and the concentration of tartrate-resistant acid phosphatase (TRAP) in serum was tested. The signaling molecules including TLR4, MyD88, NF-κB p65 and MCP-1 were detected by immunohistochemistry, quantitative real-time PCR and Western blot. RESULTS: Femoral head osteonecrosis was observed in the model rats, and the concentration of TRAP and positive staining of all signaling molecules increased significantly in group B compared with that in group A and group N. Compare with the control group, the mRNA expressions and protein levels of all signaling molecules were enhanced significantly in group B, but no significant in group A. CONCLUSIONS: Corticosteroids can induce femoral head osteonecrosis by disturbing the immune response via TLR4 signaling pathway. These findings suggest that the disruption of immune response play a role in the pathogenesis of osteonecrosis.

Foxc2 over-expression in bone marrow mesenchymal stem cells stimulates osteogenic differentiation and inhibits adipogenic differentiation.

The forkhead box C2 (Foxc2) protein, a member of the forkhead/winged helix transcription factor family, is strongly expressed in developing embryo and is required in various developmental processes. However, the precise function of Foxc2 in osteoblast differentiation remains largely unknown. The present study investigated the role of Foxc2 overexpression on osteogenic and adipogenic differentiations. In our experiment, rabbit bone marrow mesenchymal stem cells (BMSCs) were transduced with lentiviral vectors containing Foxc2 or green fluorescent protein (GFP), and the gene expression and biological activity of Foxc2 were examined in vitro. The results showed that the mRNA and protein expressions of Foxc2 were stable and high in cells transduced with Foxc2 compared with those transduced with GFP. The overexpression of Foxc2 increased the mRNA and protein levels of COLI, OCN, and OPN; enhanced the activity of ALP after osteogenic induction; and decreased the expression of PPARγ-2 and the total droplet number after adipogenic induction. In addition, Foxc2 enhanced the expression of ß-catenin, an important modulator of osteoblastogenesis. XAV939, a small molecule inhibitor of the Wnt-ß-catenin pathway, suppressed Foxc2-mediated regulation of BMSC differentiation. These findings demonstrate that the overexpression of Foxc2 gene in BMSCs may promote osteogenic differentiation and inhibit adipogenic differentiation, and this effect can be mediated via activating the canonical Wnt-ß-catenin signaling pathway.

[Construction of lentiviral vector containing Homo sapiens forkhead box C2 gene and its expression in bone marrow mesenchymal stem cells of rabbits].

OBJECTIVE: To construct the lentiviral vector containing Homo sapiens forkhead box C2 (Foxc2) gene and METHODS: Human Foxc2 gene coding to detect its expression in bone marrow mesenchymal stem cells (BMSCs) of rabbits. region fragment was obtained by RT-PCR and then cloned into the plasmid of LV-green fluorescent protein (GFP) to prepare Foxc2 lentiviral plasmid. Foxc2 lentiviral plasmid, pGC-LV, pHelperl.0, and pHelper2.0 were co-transfected into 293T cells to obtain recombinant virus containing Foxc2 gene. The lentiviral titer was detected. BMSCs were isolated from bone marrow of rabbit and infected with Foxc2 recombined lentiviral, then the optimum multiplicity of infection (MOI) was determined by detecting the intensity of fluorescence expression. The expression of Foxc2 in the infected BMSCs was determined at 1, 3, and 7 days after transfection by inverted fluorescence microscope and Western blot. After osteogenic induction, Alizarin red staining was done to observe the formation of mineralized nodule. RESULTS: The Foxc2 recombinant lentiviral vector was constructed and was confirmed by restriction enzyme digestion and sequencing analysis. It could efficiently transfect 293T cells and express in 293T cells. The lentiviral titer was 2 x 10(8) TU/mL. The optimum MOI was 200. The inverted fluorescence microscope observation showed that the Foxc2 gene expressed in 84.5% +/-4.8% of infected BMSCs at 3 days after transfection. The expression of Foxc2 in infected BMSCs was stable and high, and increased gradually within 7 days after transfection by Western blot. At 2 weeks after osteogenic induction, Alizarin red staining showed that there were a large number of red calcified matrix deposition in the cytoplasm. CONCLUSION: Foxc2 recombined lentivirus with high viral titer is successfully constructed and packaged, and the Foxc2 gene can be transfected into BMSCs with stable and high expression of Foxc2 in infected cells, and these cellls may be applied for gene therapy of avascular necrosis of the femoral head.

Foxc2 regulates osteogenesis and angiogenesis of bone marrow mesenchymal stem cells.

BACKGROUND: The Forkhead/Fox transcription factor Foxc2 is a critical regulator of osteogenesis and angiogenesis of cells. Bone marrow mesenchymal stem cells (BMSCs) have the capacity to differentiate into osteoblasts, chondrocytes, adipocytes, myocytes and fibroblasts. The present study investigates the role of Foxc2 overexpression in osteogenesis and angiogenesis of BMSCs in vitro. METHODS: BMSCs were isolated from SD rat femurs and tibias, and characterized by cell surface antigen identification and osteoblasts and adipocytes differentiation. The cells were transfected with lentiviral Foxc2 (Lv-Foxc2) or green fluorescent protein (Lv-GFP). Seventy hours later, Foxc2 expression was observed using real time-PCR and Western blot. The transfected cells were stained with Alizarin red S or alkaline phosphatase (ALP) after osteogenic induction. Meanwhile, the expression levels of osteocalcin (OCN), Runt-related transcription factor 2 (Runx2), vascular endothelial growth factor (VEGF) and platelet-derived growth factor-ß (PDGF-ß) were measured by real time-PCR, Western blot and immunostaining. RESULTS: Results of cell characterization showed that the cells were positive to CD44 (99.56%) and negative to CD34 (0.44%), and could differentiate into osteoblasts and adipocytes. Foxc2 overexpression not only increased the numbers of mineralized nodes and ALP activity, but also enhanced the expressions of Runx2, OCN, VEGF and PDGF-ß in transfected BMSCs after osteogenic induction. The effects of Foxc2 on osteogenesis and angiogenesis were significantly different between Lv-Foxc2 transfected BMSCs and Lv-GFP transfected BMSCs (P<0.05). In addition, the MAPK-specific inhibitors, PD98059 and LY294002, blocked the Foxc2-induced regulation of BMSC differentiation. CONCLUSIONS: Foxc2 gene is successfully transfected into BMSCs with stable and high expression. The overexpression of Foxc2 acts on BMSCs to stimulate osteogenesis and angiogenesis. The effect of Foxc2 on angiogenesis of the cells is mediated via activating PI3K and ERK.

[Analysis of chronergy for treatment of spinal cord injury with the allogeneic bone mesenchymal stem cells (BMscs) transplantation in rats].

OBJECTIVE: To observe the change of behavior, pathological change of the spinal cord,and expression of brain-derived neurotrophic factor (BDNF) and brain-derived neurotrophic factor (NGF) on rats with spinal cord injury in order to explore the optimal time of BMSCs transplantation. METHODS: Eighty health SD rats were randomly divided into 8 groups (group A,B,C,D,E,F,G,H), 10 rats in each group. According to the modified Allen method,the rat model of spinal cord injury was built. Group A as non-injured group only exposed the spinal cord but not result in blast injury. BMSCs of vitro culture were respectively infunded the region of spinal cord injury in group C, D, E, F, G, H (as transplantation groups) at the 0 h, 6 h, 24 h,3 d,5 d,7 d after model made. Group B as single model group was infunded the equal cell culture fluid. BBB score was used to evaluate the function of spinal cord at the 1st,2nd and 4th weeks after injury. The morphological changes of the tissue of spinal cord injury were observed by HE stain and the expression of BDNF and NGF were detected by Elisa method at the 4th weeks after BMSCs transplantation. RESULTS: In non-injured group,BBB score was highest than that of other 7 groups at the 1st, 2nd and 4th weeks after injury (P<0.01). There was no significant difference in BBB score between single model group and transplantation groups at the 1st week after BMSCs transplantation (P>0.05). BBB score in transplantation groups were higher than that of single model group at the 2nd and 4th weeks after BMSCs transplantation (P<0.05). At the 2nd week after injury, BBB score from high to low was group F,E,G,D,H,C,but there was no significant difference among the groups (P>0.05). At the 4th week after injury,there was significant differences in BBB score between group F and other transplantation groups (group C,D,E,G,H)(P0.05). The levels of BDNF and NGF in group F was highest at the 4th week after BMSCs transplantation (P<0.05). In non-injured group,HE staining showed the struction of spinal cord was clear and complete,no neutrophil was found. But in other 7 groups,HE staining showed obviously oedema at local tissue,juncture of gray and white matter was undefined,and different gliocyte proliferation and inflammatory cell infiltrate cound be found. CONCLUSION: Allogeneic BMSCs transplantation is effective to stimulate the recovery of spinal cord function in rats with spinal cord injury,and the optimal time of BMSCs transplantation maybe at the 3 d after injury.

The cyclooxygenase-2 inhibitor NS-398 inhibits proliferation and induces apoptosis in human osteosarcoma cells via downregulation of the survivin pathway.

Cyclooxygenase-2 (COX-2) is frequently overexpressed in human malignancies and plays a crucial role in tumorigenesis and cancer progression. The present study aimed to investigate the expression and clinical significance of COX-2 and survivin (SUV) in human osteosarcomas (OS), and explore the effects and molecular mechanisms of a selective COX-2 inhibitor NS-398 and SUV on tumor proliferation and apoptosis. Fifty cases of human OS and osteochondromas (OC) were collected. The expression of COX-2 and SUV was assessed using immunohistochemical assays in biopsy samples. MG-63 human OS cells were treated with different concentrations of NS-398, used to investigate their effects on cell proliferation and apoptosis. The recombinant small hairpin RNA adenovirus vector rAd5-SUV was constructed, and the effects and molecular mechanisms of knockdown of SUV on proliferation and apoptosis were evaluated in MG-63 cells. A subcutaneous xenograft tumor model was established, validating the effects of rAd5-SUV on tumor growth in vivo. Based on the results, the expression of COX-2 and SUV in OS showed a higher strong reactivity rate compared with OC (73.3 vs. 25.0%, P=0.001; 63.3 vs. 30.0%, P=0.02), but it did not correlate with the clinicopathological characteristics of OS. NS-398 inhibited proliferation, induced apoptosis and decreased the mRNA expression of COX-2 and SUV in MG-63 cells. Furthermore, adenovirus-mediated knockdown of SUV inhibited proliferation, induced apoptosis, reduced the expression of proliferating cell nuclear antigen (PCNA), increased the expression of caspase-3 (CAS-3) and slowed the growth of xenograft tumors in MG-63 cells. Taken together, the expression of COX-2 and SUV is closely correlated with human OS, and inhibition of COX-2 or knockdown of SUV suppresses tumor proliferation and induces apoptosis, suggesting that COX-2 may be involved in OS cell proliferation and apoptosis through SUV-mediated regulation of PCNA and CAS-3 expression, and provides a potential therapeutic strategy for the treatment of cancer.