[Effectiveness of sagittal top compression reduction technique in treatment of thoracolumbar vertebral fractures].

Objective: To investigate the effectiveness of sagittal top compression reduction technique in the treatment of thoracolumbar vertebral fractures. Methods: A retrospective analysis was conducted on the clinical data of 59 patients with thoracolumbar vertebral fractures who met the selection criteria and were admitted between November 2018 and January 2022. Among them, 34 patients were treated with sagittal top compression reduction technique (top pressure group), and 25 patients were treated with traditional reduction technique (traditional group). There was no significant difference in baseline data between the two groups ( P>0.05), including gender, age, fracture segment, cause of injury, AO classification of thoracolumbar vertebral fractures, thoracolumbar injury classification and severity (TLICS) score, American Spinal Injury Association (ASIA) grading, surgical approach, preoperative vertebral body index, height ratio of the anterior margin of injured vertebra, injured vertebra angle, segmental kyphosis angle, visual analogue scale (VAS) score, and Oswestry disability index (ODI). The operation time, intraoperative blood loss, and incidence of complications between the two groups were recorded and compared. After operation, VAS score and ODI were used to evaluate effectiveness, and X-ray and CT examinations were performed to measure imaging indicators such as vertebral body index, height ratio of the anterior margin of injured vertebra, injured vertebra angle, and segmental kyphosis angle. Results: There was no significant difference in operation time and intraoperative blood loss between the two groups ( P>0.05). No complication such as dural sac, nerve root, or vascular injury was found during operation, and all incisions healed by first intention. Patients in both groups were followed up 6-48 months, with an average of 20.6 months. No loosening, breakage, or failure of internal fixation occurred during follow-up. The imaging indicators, VAS score, and ODI of the two groups significantly improved at 1 week and last follow-up when compared to preoperative ones ( P<0.05). At last follow-up, the VAS score and ODI further significantly improved when compared to 1 week after operation ( P<0.05). At 1 week after operation and last follow-up, the vertebral body index, segmental kyphosis angle, injured vertebra angle, and ODI in the top pressure group were significantly better than those in the traditional group ( P<0.05). There was no significant difference in VAS score and height ratio of the anterior margin of injured vertebra between the two groups at 1 week after operation ( P>0.05), but the two indicators in the top pressure group were significantly better than those in the traditional group at last follow-up ( P<0.05). Conclusion: The treatment of thoracolumbar vertebral fractures with sagittal top compression reduction technique can significantly improve the quality of vertebral reduction, and is superior to traditional reduction techniques in relieving pain and improving spinal function.

Epigenetic modification of miR-217 promotes intervertebral disc degeneration by targeting the FBXO21-ERK signalling pathway.

BACKGROUND: Numerous potential therapeutic alternatives for intervertebral disc degeneration (IDD) have been investigated, the most promising of which are based on biological variables such as microRNAs (miRNAs). Therefore, we verified the hypothesis that miRNAs modulate IDD by affecting the FBXO21-ERK signalling pathway. METHODS: Microarray and quantitative real-time polymerase chain reaction (RT-qPCR) tests were used to examine the expression profiles of miRNAs in nucleus pulposus (NP) cells between patients with IDD and controls. Western blotting and luciferase reporter assays were used to identify the miRNA targets. RESULTS: Microarray and RT-qPCR assays confirmed that the expression level of miR-217 was significantly decreased in degenerative NP cells. CpG islands were predicted in the miR-217 promoter region. The IDD group had considerably higher methylation than the control group. Gain- and loss-of-function experiments revealed that miR-217 mimics inhibited apoptosis and extracellular matrix (ECM) breakdown in NP cells. Bioinformatic analyses and luciferase assays were used to determine the connection between miR-217 and FBXO21. In vitro tests revealed that miR-217 mimics inhibited the expression of FBXO21, pERK, MMP13, and ADAMTS5 proteins, successfully protecting the ECM from degradation. Additionally, in vivo investigation using the IDD mouse model demonstrated that the miR-217 agonist may sufficiently promote NP cell proliferation, decrease apoptosis, promote ECM synthesis, and suppress the expression of matrix-degrading enzymes in NP cells. CONCLUSIONS: Overexpression of miR-217 inhibits IDD via FBXO21/ERK regulation. TRIAL REGISTRATION: This study was performed in strict accordance with the NIH guidelines for the care and use of laboratory animals (NIH Publication No. 85-23 Rev. 1985) and was approved by the human research ethics committee of Wuhan University Renmin Hospital (Approval No. RMHREC-D-2020-391), and written informed consent was obtained from each participant.

Innate/Inflammatory Bioregulation of Surfactant Protein D Alleviates Rat Osteoarthritis by Inhibiting Toll-Like Receptor 4 Signaling.

Osteoarthritis (OA) is a deteriorating disease of cartilage tissues mainly characterized as low-grade inflammation of the joint. Innate immune molecule surfactant protein D (SP-D) is a member of collectin family of collagenous Ca2+-dependent defense lectins and plays a vital role in the inflammatory and innate immune responses. The present study investigated the SP-D-mediated innate/inflammatory bioregulation in OA and explored the underlying molecular mechanism. Transcriptome analysis revealed that SP-D regulated genes were strongly enriched in the inflammatory response, immune response, cellular response to lipopolysaccharide (LPS), PI3K-Akt signaling, Toll-like receptor (TLR) signaling, and extracellular matrix (ECM)-receptor interaction pathways. Knockdown of the SP-D gene by the recombinant adeno-associated virus promoted the macrophage specific markers of CD68, F4/80 and TLR4 in the articular cartilage in vivo. SP-D alleviated the infiltration of synovial macrophages and neutrophils, and inhibited TLR4, TNF-α and the phosphorylation of PI3K, Akt and NF-κB p65 in cartilage. SP-D suppressed cartilage degeneration, inflammatory and immune responses in the rat OA model, whilst TAK-242 strengthened this improvement. In in vitro conditions, SP-D pre-treatment inhibited LPS-induced overproduction of inflammation-correlated cytokines such as IL-1ß and TNF-α, and suppressed the overexpression of TLR4, MD-2 and NLRP3. SP-D prevented the LPS-induced degradation of ECM by down-regulating MMP-13 and up-regulating collagen II. Blocking of TLR4 by TAK-242 further enhanced these manifestations. We also demonstrated that SP-D binds to the TLR4/MD-2 complex to suppress TLR4-mediated PI3K/Akt and NF-κB signaling activation in chondrocytes. Taken together, these findings indicate that SP-D has chondroprotective properties dependent on TLR4-mediated PI3K/Akt and NF-κB signaling and that SP-D has an optimal bioregulatory effect on the inflammatory and innate responses in OA.

Epidemiologic characteristics and double-buffered strategy for patients in orthopedic surgery during the novel coronavirus outbreak: Wuhan's experience.

BACKGROUND: The purpose of this article is to summarize the epidemiologic characteristics and double-buffered strategy for patients in orthopedic surgery during the COVID-19 outbreak in Wuhan, China, based on our own experience in our hospital. METHODS: A retrospective and comparative study was performed to identify all inpatients at our clinic from February 17 to April 20, 2020 (epidemic group), and from February 17 to April 20, 2019 (control group). Epidemiologic characteristics, screening effect, perioperative complications, and nosocomial infection were analyzed. RESULTS: In the epidemic group, 82 patients were identified, a decrease by 76.0% than the 342 patients in the same period in the 2019. Patients in the epidemic group (54.6 ± 20.2 years) were older than those in the control group (49.6 ± 22.5 years). For the epidemic group, the proportion rates of traumatic factures (69.5%) and low-energy injuries (86.0%) were higher than that in the control group, respectively (35.4% and 37.2%). The preoperative waiting time (7.0 ± 2.6 days) in the epidemic group was longer than that in the control group (4.5 ± 2.1 days). The postoperative complication rate (12.2%) in the epidemic group was higher than that in the control group (3.5%). No nosocomial infection of orthopedic staff and patients with COVID-19 was noted in the epidemic group. CONCLUSION: During the COVID-19 outbreak in Wuhan, China, orthopedic inpatients showed unique epidemiological characteristics. The double-buffered strategy could effectively avoid nosocomial infections among medical staff and patients. Doctors should fully evaluate the perioperative risks and complications.

Mash-1 modified neural stem cells transplantation promotes neural stem cells differentiation into neurons to further improve locomotor functional recovery in spinal cord injury rats.

BACKGROUND: Spinal cord injury (SCI) leads to severe motor and sensory dysfunctions. Neural stem cells (NSCs) transplantation therapy plays a positive role in functional recovery after SCI, but the effectiveness of this therapy is limited by inadequate differentiation ability of transplanted NSCs. Mammalian achaete-scute homologue-1 (Mash-1) has been reported to improve differentiation of NSCs. Thus, this study modified NSCs with Mash-1 to repair SCI. METHODS: NSCs isolated from rat embryo hippocampus were cultured and identified in vitro and further transfected with the lentiviral vectors (Lv-Mash-1). After establishing a SCI rat model, the rats were transplanted with Mash-1 modified NSCs, the histopathological changes of rat spinal cord were detected by hematoxylin-eosin (HE) staining, and the locomotor activity of rats was evaluated with the Basso, Beattie and Bresnahan (BBB) scale. The NSCs cultured in vitro or extracted from SCI rat spinal cord were identified by immunofluorescence (IF). Mash-1, ß3-Tubulin, and NeuN expressions in those cells were determined by Western blotting and reverse transcription­quantitative polymerase chain reaction (RT­qPCR). RESULTS: NSCs isolated from rat embryo hippocampus were Nestin- and NeuN-positive. NSC transplantation modified by Mash-1 increased BBB score of SCI rats and promoted recovery in lesion site of SCI rats. Mash-1 overexpression also promoted ß3-Tubulin and NeuN expressions in NSCs cultured in vitro or extracted from spinal cord of SCI rats. CONCLUSION: Mash-1 overexpression promoted NSC differentiation into neurons, and further improved locomotor functional recovery of SCI rats.

Exosomes derived from miR-126-3p-overexpressing synovial fibroblasts suppress chondrocyte inflammation and cartilage degradation in a rat model of osteoarthritis.

MicroRNAs (miRNAs) encapsulated within exosomes can serve as essential regulators of intercellular communication and represent promising biomarkers of several aging-associated disorders. However, the relationship between exosomal miRNAs and osteoarthritis (OA)-related chondrocytes and synovial fibroblasts (SFCs) remain to be clarified. Herein, we profiled synovial fluid-derived exosomal miRNAs and explored the effects of exosomal miRNAs derived from SFCs on chondrocyte inflammation, proliferation, and survival, and further assessed their impact on cartilage degeneration in a surgically-induced rat OA model. We identified 19 miRNAs within synovial fluid-derived exosomes that were differentially expressed when comparing OA and control patients. We then employed a microarray-based approach to confirm that exosomal miRNA-126-3p expression was significantly reduced in OA patient-derived synovial fluid exosomes. At a functional level, miRNA-126-3p mimic treatment was sufficient to promote rat chondrocyte migration and proliferation while also suppressing apoptosis and IL-1ß, IL-6, and TNF-α expression. SFC-miRNA-126-3p-Exos were able to suppress apoptotic cell death and associated inflammation in chondrocytes. Our in vivo results revealed that rat SFC-derived exosomal miRNA-126-3p was sufficient to suppress the formation of osteophytes, prevent cartilage degeneration, and exert anti-apoptotic and anti-inflammatory effects on articular cartilage. Overall, our findings indicate that SFC exosome-delivered miRNA-126-3p can constrain chondrocyte inflammation and cartilage degeneration. As such, SFC-miRNA-126-3p-Exos may be of therapeutic value for the treatment of patients suffering from OA.

Chemically modified curcumin (CMC2.24) alleviates osteoarthritis progression by restoring cartilage homeostasis and inhibiting chondrocyte apoptosis via the NF-κB/HIF-2α axis.

The disorders of cartilage homeostasis and chondrocyte apoptosis are major events in the pathogenesis of osteoarthritis (OA). Herein, we aim to assess the chondroprotective effect and underlying mechanisms of a novel chemically modified curcumin, CMC2.24, in modulating extracellular matrix (ECM) homeostasis and inhibiting chondrocyte apoptosis. Rats underwent the anterior cruciate ligament transection, and medial menisci resection was treated by intra-articular injection with CMC2.24. In an in vitro study, rat chondrocytes were pretreated with CMC2.24 before stimulation with sodium nitroprusside (SNP). Results from in vivo studies demonstrated that the intra-articular administration of CMC2.24 ameliorated osteoarthritic cartilage destruction by promoting collagen 2a1 production and inhibited cartilage degradation and apoptosis by suppressing hypoxia-inducible factor-2a (Hif-2α), matrix metalloproteinase-3, runt-related transcription factor 2, cleaved caspase-3, and vascular endothelial growth factor and the phosphorylation of IκBα and NF-κB p65. The in vitro results revealed that CMC2.24 exhibited a strong inhibitory effect on SNP-induced chondrocyte catabolism and apoptosis. The SNP-enhanced expression of Hif-2α, a catabolic and apoptotic factor, decreased in a dose-dependent manner after CMC2.24 treatment. CMC2.24 pretreatment effectively inhibited SNP-induced IκBα and NF-κB p65 phosphorylation in rat chondrocytes, whereas pretreatment with the NF-κB antagonist BMS-345541 significantly enhanced the effects of CMC2.24. Overall, these results demonstrated that CMC2.24 attenuates OA progression by modulating ECM homeostasis and chondrocyte apoptosis by suppressing the NF-κB/Hif-2α axis, thus providing a new perspective for therapeutic strategies in OA. KEY MESSAGES: • Intra-articular injection of CMC2.24 ameliorated osteoarthritic cartilage destruction. • CMC2.24 promoted cell viability and decreased SNP-induced apoptotic gene expression. • SNP-induced activation of Hif-2α is inhibited by CMC2.24. • CMC2.24 inhibits NF-κB/Hif-2α axis activation to modulate ECM homeostasis and inhibit chondrocyte apoptosis.

Berberine-mediated up-regulation of surfactant protein D facilitates cartilage repair by modulating immune responses via the inhibition of TLR4/NF-ĸB signaling.

The innate immune system drives inflammatory joint damage in osteoarthritis (OA) and regulates cartilage repair. Berberine chloride (BBR) is an isoquinoline alkaloid that shows immunomodulatory activity in a variety of cell lines. However, the immunomodulatory mechanisms of BBR in chondrocytes during OA are largely unknown. Herein, we assessed the ability of BBR to mediate chondroprotection through its effects on innate immunity. We found that BBR up-regulated the expression of surfactant protein D (SP-D) in OA cartilage, a key regulator of inflammation and innate immunity both in the airways and extrapulmonary tissues, including joint cartilage. To further explore these findings, we used recombinant adeno-associated virus (rAAV)-mediated knockdown of SP-D. Silencing was assessed in rat model of surgically-induced OA in the presence or absence of BBR treatment, 10 weeks post-surgery. We observed a clear improvement in histological scores of BBR-treated animals compared to those treated with BBR and the rAAV-SP-D vector. In addition, animals co-treated with BBR + recombinant human SP-D (rhSP-D) exhibited significantly lower histological scores than those treated with BBR alone. BBR treatment led to significantly reduced immune cell infiltration mediated through TLR4, F4/80, CD68 and CD34, whilst SP-D silencing reversed this improvement. In contrast, rhSP-D treatment enhanced the protective phenotype. We further explored how BBR influences SP-D and other OA-associated genes in vitro. We observed an up-regulation of SP-D and a marked decline in TRAF6, TLR4, MD-2 and MyD88 expression, as well as NF-κB p65 and IκBα phosphorylation in chondrocytes treated with sodium nitroprusside. siRNAs specific for SP-D were able to partially reverse this phenotype, whilst both rhSP-D and the TLR4 inhibitor TAK-242 enhanced the effects. Together, these results are consistent with a model wherein SP-D has therapeutic potential for OA treatment. Concomitantly, BBR modulates immune responses and decreases cartilage degradation. These findings suggest that BBR achieves this function through releasing SP-D from MD2/SP-D complexes and through the inhibition of TLR4/NF-κB signaling.

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.

Ligustilide attenuates nitric oxide-induced apoptosis in rat chondrocytes and cartilage degradation via inhibiting JNK and p38 MAPK pathways.

Ligustilide (LIG) is the main lipophilic component of the Umbelliferae family of pharmaceutical plants, including Radix angelicae sinensis and Ligusticum chuanxiong. LIG shows various pharmacological properties associated with anti-inflammation and anti-apoptosis in several kinds of cell lines. However, the therapeutic effects of LIG on chondrocyte apoptosis remain unknown. In this study, we investigated whether LIG had an anti-apoptotic activity in sodium nitroprusside (SNP)-stimulated chondrocyte apoptosis and could delay cartilage degeneration in a surgically induced rat OA model, and elucidated the potential mechanisms. In vitro studies revealed that LIG significantly suppressed chondrocyte apoptosis and cytoskeletal remodelling, which maintained the nuclear morphology and increased the mitochondrial membrane potential. In terms of SNP, LIG treatment considerably reduced the expression levels of cleaved caspase-3, Bax and inducible nitric oxide synthase and increased the expression level of Bcl-2 in a dose-dependent manner. The LIG-treated groups presented a significantly suppressed expression of activating transcription factor 2 and phosphorylation of Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK). The inhibitory effect of LIG was enhanced by the p38 MAPK inhibitor SB203580 or the JNK inhibitor SP600125 and offset by the agonist anisomycin. In vivo studies demonstrated that LIG attenuated osteoarthritic cartilage destruction by inhibiting the cartilage chondrocyte apoptosis and suppressing the phosphorylation levels of activating transcription factor 2, JNK and p38 MAPK. This result was confirmed by histological analyses, micro-CT, TUNEL assay and immunohistochemical analyses. Collectively, our studies indicated that LIG protected chondrocytes against SNP-induced apoptosis and delayed articular cartilage degeneration by suppressing JNK and p38 MAPK pathways.

Surfactant protein D attenuates nitric oxide-stimulated apoptosis in rat chondrocyte by suppressing p38 MAPK signaling.

Innate immune molecule surfactant protein D (SP-D), a member of the C-type lectin protein family, plays an indispensable role in host defense and the regulation of inflammation in the lung and other tissues. Osteoarthritis (OA) is a degenerative disease of cartilage, with inflammation that causes pathologic changes and tissue damage. However, it is unknown whether there exist SP-D expression and its potential role in the pathogenesis of OA. In this study, we examined SP-D expression and explored its biological function in a sodium nitroprusside (SNP)-stimulated rat chondrocytes and surgically-induced rat OA model. We found SP-D expression in both human and rat articular chondrocytes, with higher level in normal chondrocytes compared to in OA chondrocytes. Furthermore, In vivo study demonstrated that recombinant human SP-D (rhSP-D) ameliorated cartilage degeneration in surgically-induced rat OA model. In vitro cell culture study showed that rhSP-D markedly inhibited the expression of caspase-3 as an apoptosis biomarker, and decreased phosphorylation of p38 mitogen-activated protein kinase (MAPK), which resulted in maintaining normal nuclear morphology and increasing mitochondrial membrane potential in SNP-stimulated rat chondrocytes. Collectively, these findings indicate that SP-D expresses in articular chondrocytes and suppresses SNP-stimulated chondrocyte apoptosis and ameliorates cartilage degeneration via suppressing p38 MAPK activity.

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.

Sustained release effects of berberine-loaded chitosan microspheres on in vitro chondrocyte culture.

The low bioavailability and short biological half-life of berberine chloride (BBR) negatively affect the protective role of this compound against osteoarthritis (OA). The present study was performed to evaluate the effectiveness of sustained BBR release system. Novel BBR-loaded chitosan microspheres (BBR-loaded CMs) were successfully synthesized using an ionic cross-linking method for sustained release. The basic characteristics of the prepared microspheres were subsequently evaluated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) techniques, encapsulation efficiency (EE), and in vitro release experiments. BBR-loaded CMs displayed spherical forms to encapsulate a considerable quantity of BBR (100.8 ± 2.7 mg/g); these microspheres also exhibited an ideal releasing profile. The FT-IR spectra and XRD results revealed that BBR-loaded CMs were successfully synthesized via electrostatic interaction. In vitro experiments further showed that BBR-loaded CMs significantly inhibited sodium nitroprusside (SNP)-stimulated chondrocyte apoptosis as well as cytoskeletal remodeling, and led to increasing mitochondrial membrane potential and maintaining the nuclear morphology. BBR-loaded CMs exerted markedly higher anti-apoptotic activity in the treatment of OA, and markedly inhibited the protein expression levels of caspase-3, a disintegrin, and metalloproteinase with thrombospondin motifs (ADAMTS)-5 and matrix metalloproteinase (MMP)-13 induced by SNP in rat articular chondrocytes, compared with free BBR at equivalent concentration. Therefore, novel BBR-loaded CMs may offer potential for application in the treatment of OA.

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.