Therapeutic effect of transplantation of human bone marrow­derived mesenchymal stem cells on neuron regeneration in a rat model of middle cerebral artery occlusion.

Human bone marrow­derived mesenchymal stromal cells (hBMSCs) have been revealed to be beneficial for the regeneration of tissues and cells in several diseases. The present study aimed to elucidate the mechanisms underlying the effect of hBMSC transplantation on neuron regeneration in a rat model of middle cerebral artery occlusion (MCAO). The hBMSCs were isolated, cultured and identified. A rat model of MCAO was induced via the modified Longa method. Neurological severity scores (NSS) were adopted for the evaluation of neuronal function in the model rats after cell transplantation. Next, the expression levels of nestin, ß­III­tubulin (ß­III­Tub), glial fibrillary acidic protein (GFAP), HNA and neuronal nuclear antigen (NeuN) were examined, as well as the positive expression rates of human neutrophil alloantigen (HNA), nestin, NeuN, ß­III­Tub and GFAP. The NSS, as well as the mRNA and protein expression of nestin, decreased at the 1st, 2nd, 4 and 8th weeks, while the mRNA and protein expression of NeuN, ß­III­Tub and GFAP increased with time. In addition, after treatment, the MCAO rats showed decreased NSS and mRNA and protein expression of nestin, but elevated mRNA and protein expression of NeuN, ß­III­Tub and GFAP at the 2nd, 4 and 8th weeks, and decreased positive expression of HNA and nestin with enhanced expression of NeuN, ß­III­Tub and GFAP. Therefore, the present findings demonstrated that hBMSC transplantation triggered the formation of nerve cells and enhanced neuronal function in a rat model of MCAO.

The effects of chitosan oligosaccharides on OPG and RANKL expression in a rat osteoarthritis model.

PURPOSE:: To investigate the effect of chitosan oligosaccharides (COS) against osteoarthritis (OA) and preliminarily discuss the osteoprotegerin (OPG), receptor activator of NF-κB ligand (RANKL) and RANK expression in a rat OA model. METHODS:: Thirty-six 6-week-old Male SD rats were randomly divided into three groups: sham-operated group(CON), OA-induction group(OA), COS intervention group(n=12/group). At 4 weeks after the operation, COS (50 ul) intervention weekily for consecutive 5 weeks. The OA and CON groups received an injection of 50 ul physiological saline. At death, 11 weeks following surgery, cartilage was harvested and total RNA and protein were extracted. Both the morphological changes of the cartilage were observed and harvested the total RNA and protein. Meanwhile, the expression of OPG, RANKL and RANK in cartilage were determined. RESULTS:: The expression of OPG and RANKL were both enhanced in the cartilage of the OA model. Compared with the OA group, COS treatment improved the cartilage damage (both extent and grade). Furthermore, the COS group showed highly OPG and lower RANKL. Simultaneously, COS treatment upregulated the ratio of OPG/RANKL and downregulated the RANKL/RANK. CONCLUSION:: Chitosan oligosaccharides may be used as a unique biological agent to prevent and treat osteoarthritis, and this effect is associated with modulation of the expression of osteoprotegerin and receptor activator of NF-κB ligand.

The effects of chitosan oligosaccharides on OPG and RANKL expression in a rat osteoarthritis model

Abstract Purpose: To investigate the effect of chitosan oligosaccharides (COS) against osteoarthritis (OA) and preliminarily discuss the osteoprotegerin (OPG), receptor activator of NF-κB ligand (RANKL) and RANK expression in a rat OA model. Methods: Thirty-six 6-week-old Male SD rats were randomly divided into three groups: sham-operated group(CON), OA-induction group(OA), COS intervention group(n=12/group). At 4 weeks after the operation, COS (50 ul) intervention weekily for consecutive 5 weeks. The OA and CON groups received an injection of 50 ul physiological saline. At death, 11 weeks following surgery, cartilage was harvested and total RNA and protein were extracted. Both the morphological changes of the cartilage were observed and harvested the total RNA and protein. Meanwhile, the expression of OPG, RANKL and RANK in cartilage were determined. Results: The expression of OPG and RANKL were both enhanced in the cartilage of the OA model. Compared with the OA group, COS treatment improved the cartilage damage (both extent and grade). Furthermore, the COS group showed highly OPG and lower RANKL. Simultaneously, COS treatment upregulated the ratio of OPG/RANKL and downregulated the RANKL/RANK. Conclusion: Chitosan oligosaccharides may be used as a unique biological agent to prevent and treat osteoarthritis, and this effect is associated with modulation of the expression of osteoprotegerin and receptor activator of NF-κB ligand.

Clinical therapeutic effects of anterior decompression on spinal osteoporotic fracture and inflammatory cytokines.

OBJECTIVE: To evaluate the clinical therapeutic effects of anterior decompression on spinal osteoporotic fracture and inflammatory cytokines. METHODS: A total of 140 patients with spinal osteoporotic fracture were selected and randomly divided into a treatment group and a control group (n=70). The control group was treated by central corpectomy, and the control group was treated by anterior decompression. RESULTS: The rate of excellent and good outcomes in the treatment group was 94.3%, and that of the control group was 78.6%, which differed significantly (P<0.05). Cobb angle and cord occupancy in the spinal canal of both groups significantly decreased (P<0.05), while height ratio of the injured vertebral body significantly increased (P<0.05). Meanwhile, there were statistically significant inter-group differences (P<0.05). During the three-month follow-up period, the treatment group was significantly less prone to complications such as superficial infection, spinal instability and screw breakage compared with the control group (P<0.05). The postoperative serum MMP-3 and IL-6 levels of both groups significantly decreased compared with those before surgeries (P<0.05), with statistically significant inter-group differences (P<0.05). CONCLUSION: Compared with central corpectomy, anterior decompression exerted better effects on spinal osteoporotic fracture by improving the prognosis and stabilizing the spine safely, which may be associated with the effectively reduced serum MMP-3 and IL-6 levels.

PKCa Agonists Enhance the Protective Effect of Hyaluronic Acid on Nitric Oxide-Induced Apoptosis of Articular Chondrocytes in Vitro.

OBJECTIVE(S): Protein kinase C (PKCα) is involved in modulating articular chondrocytes apoptosis induced by nitric oxide (NO). Hyaluronic acid (HA) inhibits nitric oxide-induced apoptosis of articular chondrocytes by protecting PKCα, but the mechanism remains unclear. The present study was performed to investigate the effects and mechanisms of PKCα regulate protective effect of hyaluronic acid. Materials and Methods The ratio of apoptotic cell and cell viability was surveyed by PCNA and MTT assay. The expression of caspase-3 was determined by real-time PCR and western blot. RESULTS: It was showed that HA was able to reduce the nuclei fragment and PCNA expression, and NO-induced articular apoptosis blocked by HA, pretreated chondrocytes with PMA, HA significantly inhibits the activation of caspase-3 induced by NO, but pretrement with CHR, HA significantly incresed the expression of caspase-3. CONCLUSION: The results may be showed that PKCa regulate the expresion of caspase-3, which contribute to the apoptosis of chondrocytes induced by NO. PKC α agonists enhance the protective effect of hyaluronic acid on nitric oxide-induced articular chondrocytes apoptosis.

Hyaluronic acid inhibits nitric oxide-induced apoptosis and dedifferentiation of articular chondrocytes in vitro.

OBJECTIVE: Nitric oxide is an important mediator in Osteoarthritis (OA), and causes apoptosis and dedifferentiation in articular chondrocytes. Protein kinase Calpha is involved in modulating apoptosis and dedifferentiation of articular chondrocytes induced by nitric oxide. Hyaluronic acid is widely used in the treatment of osteoarthritis and exerts significant chondroprotective effects. The exact mechanisms of its chondroprotective action are not yet fully elucidated. The present study was performed to investigate the effects and mechanisms of hyaluronic acid in NO-induced apoptosis and dedifferentiation of chondrocytes. METHODS: The ratio of apoptotic cell and cell viability was surveyed by TUNEL, MTT assay and flow cytometry. The expression of aggrecan, type II collagen, and PKCalpha were determined by real-time PCR and Western blot. The expression changes of caspase-3 and bcl-2 was detected by Western blot. The mitochondrial membrane potential (DeltaPsim) was evaluated by Rhodamine-123 fluorescence. RESULTS: HA reduces the TUNEL positive cell, nuclei fragment and the impairment of DeltaPsim. NO-induced chondrocyte dedifferentiation was blocked by HA, which restores expression of aggrecan and type II collagen of chondrocytes and cell viability. HA can block inhibition of PKC-alpha by NO. CONCLUSION: Our results show that HA blocks NO-induced apoptosis and dedifferentiation of articular chondrocytes by modulation of DeltaPsim and PKCalpha.

Effects of hyaluronan on vascular endothelial growth factor and receptor-2 expression in a rabbit osteoarthritis model.

BACKGROUND: Little is known about the expression of vascular endothelial growth factor (VEGF) and its receptor-2 (VEGFR-2) mRNA in the cartilage of a rabbit osteoarthritis model or the influence of intraarticular injection of hyaluronan (HA) on the expression of VEGF and VEGFR-2 in cartilage during the process of osteoarthritis (OA). The therapeutic mechanism of HA is not completely understood, and we hypothesize that the mechanism is through the effects of VEGF and VEGFR2. In this study, we determined the VEGF and VEGFR-2 mRNA expression in a rabbit OA model and assessed the therapeutic mechanism of HA against OA. METHODS: We carried out this study at the Center Laboratory of Renmin Hospital at Wuhan University and the Key Laboratory of Respiratory Disease of the Ministry of Public Health, Huazhong University of Science and Technology. Between October 2006 and April 2008 a total of 24 mature New Zealand white rabbits were divided into three groups: normal controls, a no-HA group, and an HA group. The no-HA and HA groups underwent unilateral anterior cruciate ligament transection. At 4 weeks after the operation, animals in the HA group received intraarticular injections of 1% sodium hyaluronate (HA) once a week for 5 weeks as per the clinical treatment presently utilized. The no-HA rabbits were not given HA. At death, 11 weeks following surgery, cartilage was harvested and total RNA was extracted. VEGF and VEGFR mRNAs were analyzed using the reverse transcription-polymerase chain reaction (RT-PCR) and real-time PCR for each group. RESULTS: Cartilage damage (both extent and grade) was less severe in the HA group than in the no-HA group. VEGF and VEGFR-2 mRNA expression was enhanced in the cartilage of the OA model. Intraarticular 1% sodium hyaluronate injection inhibited VEGFR-2 expression but had no effect on reducing the VEGF mRNA expression in cartilage. CONCLUSIONS: These results suggested that VEGF and VEGFR-2 may be involved in the progression of OA and in the therapeutic mechanism of HA at least partly through the influence of VEGFR-2 expression during the development of OA.

The protective effect of sodium hyaluronate on the cartilage of rabbit osteoarthritis by inhibiting peroxisome proliferator-activated receptor-gamma messenger RNA expression.

PURPOSE: The purpose of this study was to study the protective effect and influence of sodium hyaluronate (Na-HA) on mRNA expression of peroxisome proliferators-activated receptor gamma (PPAR-gamma) in cartilage of rabbit osteoarthritis (OA) model. MATERIALS AND METHODS: Forty eight white rabbits were randomly divided into A, B, and C groups. Group A was normal control group, B and C groups underwent unilateral anterior cruciate ligament transection (ACLT). The rabbits in group B were injected normal saline after ACLT; and Group C received intra-articular 1% sodium hyaluronate (HA) injection 5 weeks after surgery, 0.3 mL once a week. At 11th week after surgery, all the rabbits were sacrificed. The cartilage changes on the medial femoral condyles were graded separately. Cartilage sections were stained with safranin-O and HE, and messenger RNA (mRNA) expression of PPAR-gamma was detected by using real time polymerase chain reaction (Real Time-PCR). RESULTS: Cartilage degeneration in group B was significantly more severe than in A and C injection group. The grey value of Safranin-O of B group was higher than A and C groups. Expression of PPAR-gamma mRNA in group B was higher than group A and C. CONCLUSION: This study shows that Na-HA has a protective effect on articular cartilage degeneration, and the inhibitory effect on the PPAR-gamma mRNA expression may be one of therapeutic mechanism of Na-HA.

Comparison of therapeutic effect between percutaneous vertebroplasty and kyphoplasty on vertebral compression fracture.

OBJECTIVE: To compare the clinical efficacy of percutaneous vertebroplasty (PVP) with percutaneous kyphoplasty (PKP) in the treatment of vertebral compression fracture (VCF). METHODS: Ninety-eight patients with VCF were treated by PVP (n=42) or PKP (n=56). The anterior midline and posterior heights of vertebrae body, preoperative and postoperative visual analogue scale (VAS), operation time and amount of blood loss were compared between 2 groups. RESULTS: There was statistical difference in vertebral height between two groups (P < 0.01). No significant difference was seen in VAS, operation time and blood loss between two groups (P < 0.05). CONCLUSIONS: PKP and PVP have the similar therapeutic efficacy in treatment of VCF with minimal invasion, less operation time and blood loss. However, PKP is superior in the recovery of vertebral height.

Effect of allograft compound vertebra on vertebral reconstruction in rabbits.

OBJECTIVE: To study the effect of allograft compound vertebra on vertebral reconstruction in rabbits so as to provide biomechanical direction for manufacturing and selecting vertebral reconstruction materials. METHODS: Twenty-five healthy New Zealand white rabbits were divided randomly into three groups: normal group (Group A, n equal to 5),iliac bone graft group (Group B, n equal to 10) and allograft compound vertebra group (Group C, equal to 10). After C4 was resected, iliac bone implantation and allograft bone cage transplantation were fulfilled in Group B and Group C, respectively. Every 5 rabbits from Group B and Group C were selected to test the biomechanical strength and biological activity one and two months postoperatively. RESULTS: No significant statistical difference was found between Group A and Group C one and two months postoperatively (P larger than 0.05). The biomechanical strength of Group B was much weaker than that of Group A and Group C one month postoperatively (P less than 0.05), but at two months postoperatively, no statistical difference was found among the three groups. The biological activity and vertebral moulding ability of Group C were better than those of Group B at one and two months postoperatively. CONCLUSIONS: Compound vertebra, which is made up of allograft cortical bone cage and autogenous cancellous bone, shows instantaneous and permanent biomechanical stability and biological activity, therefore, it is an ideal material for vertebral reconstruction.

Comparison of therapeutic effect between percutaneous kyphoplasty and pedicle screw system on vertebral compression fracture.

OBJECTIVE: To compare the clinical efficacy of percutaneous kyphoplasty (PKP) with pedicle screw system (PS) in the treatment of vertebral compression fracture(VCF). METHODS: Eighty-six patients with VCF were treated either by PKP (Group A, n equal to 30) or PS (Group B, n equal to 56). The anterior, intermediate, and posterior heights of the vertebrae body, visual analogue pain scale (VAS) before and after operation, the duration of operation, and amount of blood loss between two groups were compared. RESULTS: No statistical difference was noted regarding the vertebral height between two groups. Significant difference was seen in VAS, duration of operation and amount of blood loss between the two groups (P less than 0.01). CONCLUSIONS: Percutaneous kyphoplasty has the similar therapeutic efficacy with pedicle screw system in treatment of VCF with a minimal invasion, less operation time and blood loss. For those with posterior wall destruction, PS is deemed favorable.

Biomechanical analysis of fracture fixation with external fixator in vivo.

OBJECTIVE: To investigate the different ways of measuring the main axial strain during treatment with an external fixator and to find the suitable compression loaded by the external fixator at an early stage. METHODS: Eighteen healthy big-ear rabbits were randomly divided into two groups according to different measuring methods: Group A and Group B. In Group A, a strain gauge was affixed to the external tibial cortex with 502 glue, and in Group B, a bone cement-coated strain gauge was installed on the internal tibial cortex. Groups A and B were divided into two subgroups A1, A2 and B1, B2, respectively, according to the pressure of half of and the same as the body weight. A Z-shaped left mid-shaft tibial osteotomy was performed and fixed by an external fixator. RESULTS: The scaler curves of Group A changed dramatically during the early stage. The trendlines of the internal and external cortex went consistently after reaching the stable stage while the latter strain value was higher than the former. The time for Group B reaching the stable stage was short, but its absolute strain value was less than that of Group A. Before they were pressed to the stable stage, the declined speed of Subgroup A1 was more slowly than that of Subgroup A2 while the results of Subgroups B1 and B2 were same. Group A had an ascending trend after it declined while Group B didn't have. After they reached the stable stage, both Subgroups A1 and A2 had a declining trend while Subgroup A2 was more quickly than Subgroup A1, Subgroup B1 was kept at a definite level while Subgroup B2 fluctuated. CONCLUSIONS: The axial strain under external fixator can be measured by bone cement coated-strain gauge in vivo. The data may suggest that half of the body weight load was suitable for external fixator.