FoxO3 Regulates Mouse Bone Mesenchymal Stem Cell Fate and Bone-Fat Balance During Skeletal Aging.

Age-related osteoporosis is characterized by an imbalance between osteogenic and adipogenic differentiation in bone mesenchymal stem cells (BMSCs). Forkhead box O 3 (FoxO3) transcription factor is involved in lifespan and cell differentiation. In this study, we explore whether FoxO3 regulates age-related bone loss and marrow fat accumulation. The expression levels of FoxO3 in BMSCs during aging were detected in vivo and in vitro. To explore the role of FoxO3 in osteogenic and adipogenic differentiation, primary BMSCs were isolated from young and aged mice. FoxO3 expression was modulated by adenoviral vector transfection. The role of FoxO3 in bone-fat balance was evaluated by alizarin red S staining, oil red O staining, quantitative reverse transcription-polymerase chain reaction, Western blot, and histological analysis. Age-related bone loss and fat deposit are associated with downregulation of FoxO3. Overexpression of FoxO3 alleviated age-related bone loss and marrow fat accumulation in aged mice. Mechanistically, FoxO3 reduced adipogenesis and enhanced osteogenesis of BMSCs via downregulation of PPAR-γ and Notch signaling, respectively. In conclusion, FoxO3 is an essential factor controlling the fate of BMSCs and is a potential target for the prevention of age-related osteoporosis.

A Bionic Thermosensitive Sustainable Delivery System for Reversing the Progression of Osteoarthritis by Remodeling the Joint Homeostasis.

Although the pathogenesis of osteoarthritis (OA) is unclear, inflammatory cytokines are related to its occurrence. However, few studies focused on the therapeutic strategies of regulating joint homeostasis by simultaneously remodeling the anti-inflammatory and immunomodulatory microenvironments. Fibroblast growth factor 18 (FGF18) is the only disease-modifying OA drug (DMOAD) with a potent ability and high efficiency in maintaining the phenotype of chondrocytes within cell culture models. However, its potential role in the immune microenvironment remains unknown. Besides, information on an optimal carrier, whose interface and chondral-biomimetic microenvironment mimic the native articular tissue, is still lacking, which substantially limits the clinical efficacy of FGF18. Herein, to simulate the cartilage matrix, chondroitin sulfate (ChS)-based nanoparticles (NPs) are integrated into poly(D, L-lactide)-poly(ethylene glycol)-poly(D, L-lactide) (PLEL) hydrogels to develop a bionic thermosensitive sustainable delivery system. Electrostatically self-assembled ChS and ε-poly-l-lysine (EPL) NPs are prepared for the bioencapsulation of FGF18. This bionic delivery system suppressed the inflammatory response in interleukin-1ß (IL-1ß)-mediated chondrocytes, promoted macrophage M2 polarization, and inhibited M1 polarization, thereby ameliorating cartilage degeneration and synovitis in OA. Thus, the ChS-based hydrogel system offers a potential strategy to regulate the chondrocyte-macrophage crosstalk, thus re-establishing the anti-inflammatory and immunomodulatory microenvironment for OA therapy.

Stabilization of hypoxia-inducible factor-1α alleviates osteoarthritis via interacting with Per2 and resetting the circadian clock.

OBJECTIVE: The study aimed to establish whether HIF1α entrains the core clock in chondrocytes and how the HIF1α affects the circadian rhythm. METHODS: We subjected primary chondrocytes to chronic circadian desynchrony (CCD) and subsequently treated with oxygen rhythm and dimethyloxalylglycine (DMOG). Circadian oscillations were analyzed with a real-time monitoring system of Per2 promoter activity and qPCR. Chondrocytes were assayed core clock genes expression patterns and extracellular matrix metabolism. HIF1α siRNA was used to knock down HIF1α. ChIP-qPCR and dual-luciferase reporter assay were used to validate that Per2 was the target gene of HIF1α. The surgical model of osteoarthritis was induced by destabilization of the medial meniscus (DMM). The chronic jet lag model was established light/dark cycle advance shift. Joint degeneration was measured using histological staining, immunological assays, and micro-CT scanning. RESULTS: We report that different patterns of clock genes expression between healthy and osteoarthritic cartilage tissues and oxygen rhythms and DMOG reset the molecular clockwork which was dampened after CCD culture in a HIF1α-dependent manner. HIF1α increased the amplitude of oscillation by directly binding to the HRE-like and E-box-like elements located on the Per2 promoter. The rhythmic circadian clock significantly enhanced extracellular matrix production. Our study also demonstrates that DMOG ameliorated the increased OA severity caused by jet lag in the DMM model. CONCLUSIONS: This study shows that circadian clock resetting caused by DMOG is at least partially mediated by the HIF1α through interaction with the Per2 promoter and proposes DMOG as supportive therapy for OA.

Comparison of Hidden Blood Loss Between Three Different Surgical Approaches for Treatment of Thoracolumbar Fracture.

Purpose: To examine the hidden blood loss (HBL) in treatment of AO type A1-A3 thoracolumbar fractures with three different approaches and to explore the influential factors of HBL among patients after the surgery of internal fixation for thoracolumbar fractures. Methods: We retrospectively studied 85 patients in treatment of thoracolumbar fractures: 25 patients via percutaneous approach (Group A), 33 patients via paraspinal approach (Group B), and 27 patients via conventional open approach (Group C). The demographic information of the patients was collected. Each patient's preoperative and postoperative hematocrit were recorded and used for calculating the blood loss according to the Gross's formula. The difference of blood loss between the three groups was measured by ANOVA. And influential factors were further analyzed by multivariate linear regression analysis in each group. Results: The average HBL was 240.0 ± 65.1 mL in Group A, 313.7 ± 138.1 mL in Group B, and 382 ± 153.8 mL in Group C. There was statistical difference in the HBL between three groups (P = 0.000). However, multivariate linear regression analysis revealed that HBL of three approaches was not associated with age, gender, body mass index (BMI), percentage of height loss, percentage of height restoration, fracture type, or operation time. Conclusion: There was a substantial HBL in the treatment of thoracolumbar fractures, which was neglected by surgeons. Further investigation is necessary to study the risk factors for surgery on HBL in treatment of thoracolumbar fractures.

The Role of Unilateral Balloon Kyphoplasty for the Treatment of Patients with OVCFS: A Systematic Review and Meta-Analysis.

BACKGROUND: An increasing number of studies have been conducted to apply unilateral balloon kyphoplasty in the treatment of ostroporotic vertebral compression fractures (OVCFs). However, the efficacy and safety of unilateral kyphoplasty and whether a unilateral or a bilateral approach is superior is controversial. OBJECTIVES: The purpose of this study was to evaluate the role of unilateral balloon kyphoplasty and use meta-analysis to compare the efficacy and safety of unilateral and bilateral kyphoplasty in patients with OVCFs. STUDY DESIGN: A systematic literature search was conducted from 1970 to April 2017 using Medline database and the Cochrane Central Register of Controlled Trials. Articles were limited to those published in English. Randomized controlled trials and nonrandomized comparative studies were also included. SETTING: The following search terms were used: "osteoporotic vertebral compression fractures," or "OVCF," and "unilateral kyphoplasty," or "unipedicular approach," or "single balloon kyphoplasty," or "one balloon kyphoplasty." A comprehensive search of reference lists of retrieved articles and previous published reviews was also performed to ensure inclusion of all possible studies. METHODS: All potential articles were independently reviewed by 2 investigators for inclusion into the final analysis. MINORS score was used for nonrandomized studies, and Detsky quality index was applied for prospective randomized controlled trials. Systematic review and meta-analysis was performed for the included studies. RESULTS: After unilateral balloon kyphoplasty the mean postoperative visual analog score (VAS) was from 1.74 to 4.77, mean postoperative kyphotic angle was from 5.9º to 11.22º, and complications involving cement leaks was from 6.8 to 21.9% or adjacent level fractures was from 0 to 5.6%). Unilateral kyphoplasty had significantly lower operative time, and less bone cement volume; however, the postoperative VAS, Oswestry Disability Index (ODI), vertebral height restoration rate, and cement leakage and adjacent vertebral fracture rate, were similar to bilateral kyphoplasty. LIMITATIONS: Only 6 randomized controlled trials and 3 retrospective comparative studies were selected for analysis. Heterogeneity was detected among the studies when we pooled the outcomes. CONCLUSIONS: Based on the available evidence, the clinical and radiological results of unilateral balloon kyphoplasty were as good as those of bilateral balloon kyphoplasty for the treatment of OVCFs. And unilateral kyphoplasty had advantages in terms of operation time, radiation exposure, and cost. KEY WORDS: Unilateral balloon kyphoplasty, bilateral balloon kyphoplasty, osteoporotic vertebral compression fractures, complications of balloon kyphoplasty, meta-analysis.

Masquelet's induced membrane promotes the osteogenic differentiation of bone marrow mesenchymal stem cells by activating the Smad and MAPK pathways.

The Masquelet's induced membrane (IM) technique is widely used to treat large segmental bone defects due to its physical priority and biological function. However, the underlying molecular mechanism of the IM on bone formation remains unknown. In the present study, rat bone marrow-derived mesenchymal stem cells (BMSCs) were used as an in vitro model and bone morphogenetic protein 2 (BMP-2) was used as a positive control to evaluate the effects of the IM on the osteogenic differentiation of BMSCs. Although the IM group did not exhibit a significant increase in the expression of Runt-related transcription factor 2 (Runx2), Collagen I (Col I), osteocalcin (OCN) and alkaline phosphatase (ALP) relative to the BMP-2 administration, the IM was considerably effective compared with the untreated group. Mechanistically, we found that the IM activated the Smad and mitogen-activated protein kinase (MAPK) pathways, which was further confirmed by application of specific inhibitors of Smad1/5/8 (LDN-193189) and ERK1/2 (U0126). After the combined treatment of the IM and LDN-193189 as well as U0126, the IM-induced increase in Runx2, Col I, and OCN expression was significantly inhibited. These results suggest that IM promotes the osteogenic differentiation of rat BMSCs by activating the Smad1/5/8 and MAPK pathways.

Inhibition of Dll4/Notch1 pathway promotes angiogenesis of Masquelet's induced membrane in rats.

The Masquelet's induced membrane technique for repairing bone defects has been demonstrated to be a promising treatment strategy. Previous studies have shown that the vessel density of induced membrane is decreased in the late stage of membrane formation, which consequently disrupts the bone healing process. However, relatively little is known about certain mechanisms of vessel degeneration in the induced membrane tissue and whether promotion of angiogenesis in induced membranes can improve bone regeneration. Here, we showed that the Delta-like ligand 4/ Notch homolog 1 (Dll4/Notch1) pathway was relatively activated in the late stage of induced membrane, especially at the subcutaneous site. Then, DAPT, a classical γ-secretase inhibitor, was applied to specifically inhibit Notch1 activation, followed by up-regulation of vascular endothelial growth factor receptor 2 (VEGFR2) and CD31 expression. DAPT-modified induced membranes were further confirmed to contribute to bone regeneration after autogenous bone grafting. Finally, in vitro experiments revealed that knocking down Notch1 contributed to the functional improvement of endothelial progenitor cells (EPCs) and that DAPT-treated induced membrane tissue was more favorable for angiogenesis of EPCs compared with the vehicle group. In conclusion, the present findings demonstrate that Dll4/Notch1 signaling is negatively associated with the vessel density of induced membrane. Pharmacological inhibition of Notch1 attenuated the vessel degeneration of induced membrane both in vitro and in vivo, which consequently improved bone formation at the bone defect site and graft resorption at the subcutaneous site.

Asperosaponin VI promotes angiogenesis and accelerates wound healing in rats via up-regulating HIF-1α/VEGF signaling.

Wound therapy remains a clinical challenge due to the complexity of healing pathology and high demand of achieving functional and aesthetically satisfactory scars. Newly formed blood vessels are essential for tissue repair since they can support cells at the wound site with nutrition and oxygen. In this study, we investigated the effects of Asperosaponin VI (ASA VI) isolated from a traditional Chinese medicine, the root of Dipsacus asper Wall, in promoting angiogenesis, as well as its function in wound therapeutics. Treatment of human umbilical vein endothelial cells (HUVECs) with ASA VI (20-80 µg/mL) dose-dependently promoted the proliferation, migration and enhanced their angiogenic ability in vitro, which were associated with the up-regulated HIF-1α/VEGF signaling. Full-thickness cutaneous wound model rats were injected with ASA VI (20 mg·kg-1·d-1, iv) for 21 d. Administration of ASA VI significantly promoted the cutaneous wound healing, and more blood vessels were observed in the regenerated tissue. Due to rapid vascularization, the cellular proliferation status, granulation tissue formation, collagen matrix deposition and remodeling processes were all accelerated, resulting in efficient wound healing. In summary, ASA VI promotes angiogenesis of HUVECs in vitro via up-regulating the HIF-1α/VEGF pathway, and efficiently enhances the vascularization in regenerated tissue and facilitates wound healing in vivo. The results reveal that ASA VI is a potential therapeutic for vessel injury-related wounds.

Efficacy of Using Intermediate Screws in Short-Segment Fixation for Thoracolumbar Fractures: A Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Some studies have reported that the conventional intersegmental pedicle screws (4-screw fixation [4S]) device for thoracolumbar fractures was associated with inadequate reduction of fractured vertebrae, insufficient correction of kyphosis, and implant failure. Recently, a series of biomechanical studies has confirmed that the addition of intermediate fixation screws (6-screw fixation [6S]) could provide stronger fixation and better reduction of fractured vertebrae. Nevertheless, the clinical and radiologic efficacy of the additional intermediate screws remains unclear. METHODS: A meta-analysis of randomized controlled trials was used to compare clinical and radiologic outcomes and complications of posterior pedicle screws combined with intermediate screws fixation versus conventional intersegmental pedicle screw fixation. We comprehensively searched MEDLINE, OVID, and Springer according to a search strategy, selecting articles based on inclusion criteria, and extracted data from these reports. Risk of bias in included studies was assessed. Pooled estimates and corresponding 95% confidence intervals were calculated. RESULTS: Six randomized controlled trials involving 310 patients were evaluated in this meta-analysis. Pooled estimates showed statistically similar baseline characteristics, hospital stays, postoperative visual analog scale scores, and infection rates between the 4S group and the 6S group. The 6S group had significantly less correction loss of segmental angle and of anterior vertebral height compression, and lower implant failure rate. The 6S group also showed a slightly longer operative time and more blood loss than did the 4S group. CONCLUSIONS: Based on our analysis, the combined intermediate screws fixation technique was associated with significantly improved radiologic outcomes but did not seem to compromise other perioperative outcomes.

Lithium chloride contributes to blood-spinal cord barrier integrity and functional recovery from spinal cord injury by stimulating autophagic flux.

Blood-spinal cord barrier (BSCB) disruption following spinal cord injury (SCI) significantly compromises functional neuronal recovery. Autophagy is a potential therapeutic target when seeking to protect the BSCB. We explored the effects of lithium chloride (LiCl) on BSCB permeability and autophagy-induced SCI both in a rat model of SCI and in endothelial cells subjected to oxygen-glucose deprivation. We evaluated BSCB status using the Evans Blue dye extravasation test and measurement of tight junction (TJ) protein levels; we also assessed functional locomotor recovery. We detected autophagy-associated proteins in vivo and in vitro using both Western blotting and immunofluorescence staining. We found that, in a rat model of SCI, LiCl attenuated the elevation in BSCB permeability, improved locomotor recovery, and inhibited the degradation of TJ proteins including occludin and claudin-5. LiCl significantly induced the extent of autophagic flux after SCI by increasing LC3-II and ATG-5 levels, and abolishing p62 accumulation. In addition, a combination of LiCl and the autophagy inhibitor chloroquine not only partially eliminated the BSCB-protective effect of LiCl, but also exacerbated TJ protein degradation both in vivo and in vitro. Together, these findings suggest that LiCl treatment alleviates BSCB disruption and promotes locomotor recovery after SCI, partly by stimulating autophagic flux.

Wogonoside inhibits IL-1ß induced catabolism and hypertrophy in mouse chondrocyte and ameliorates murine osteoarthritis.

The inflammatory environment is correlated with extracellular matrix (ECM) degradation and chondrocyte hypertrophy in the development of osteoarthritis (OA). Previous studies have reported the anti-inflammatory effects of wogonoside in several diseases. In the present study, we investigated the protective effects of wogonoside in relation to the development of OA and delineated the potential mechanism. In vitro, wogonoside decreased the production of pro-inflammatory cytokines like Nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor alpha (TNF-α), and interleukin-6 (IL-6). It also inhibited the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) both at gene and protein levels. Wogonoside also inhibited hypertrophy and the generation of vascular endothelial growth factor (VEGF) in interleukin-1ß (IL-1ß)-induced chondrocytes. Moreover, wogonoside promoted the expression of anabolic factors Sox-9, type two collagen and aggrecan while inhibiting the expression of catabolic factors such as matrix metalloproteinases (MMPs) and thrombospondin motifs 5 (ADAMTS-5) in mouse chondrocytes. Mechanistically, we found that wogonoside inhibited nuclear factor kappa B/ hypoxia-inducible factor two alpha (NF-κB/HIF-2α) activation via the phosphatidylinositol 3 kinase (PI3K) /AKT pathway. The protective effects of wogonoside were also observed in vivo and the pharmacokinetic results of wogonoside indicated that good systemic exposure was achievable after oral administration of wogonoside. In conclusion, our stduy demonstrates that wogonoside attenuates IL-1ß-induced ECM degradation and hypertrophy in mouse chondrocytes via suppressing the activation of NF-κB/HIF-2α by the PI3K/AKT pathway. Moreover, wogonoside ameliorates OA progression in vivo, indicating that wogonoside may serve as a promising therapeutic agent for the treatment of OA.

Piceatannol inhibits the IL-1ß-induced inflammatory response in human osteoarthritic chondrocytes and ameliorates osteoarthritis in mice by activating Nrf2.

Osteoarthritis (OA) is a complex process, to which an inflammatory environment contributes markedly. Piceatannol exerts anti-inflammatory effects on several diseases. In the current study, we explored the protective effects of piceatannol on the progression of OA and investigated its molecular target. In vitro, piceatannol not only attenuated the over-production of inflammatory mediators and cytokines-such as nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor alpha (TNF-α), and interleukin-6 (IL-6)-but also suppressed the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) at both the mRNA and protein levels. Piceatannol also decreased the expression of metalloproteinase 13 (MMP13) and thrombospondin motifs 5 (ADAMTS5), which mediate extracellular matrix degradation. Mechanistically, we found that piceatannol inhibited IL-1ß-induced nuclear factor kappa B (NF-κB) activation by activating the nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/heme oxygenase 1 (HO-1) pathway. Furthermore, piceatannol exerted protective effects in a mouse model of OA. Taken together, these findings indicate that piceatannol may be a potential therapeutic agent for OA.

The Spinal Cord Line Can Predict Postoperative Recovery for Multilevel Cervical Spondylotic Myelopathy.

OBJECTIVE: To report a new index, the spinal cord (SC) line, and a new classification to predict postoperative recovery effect in patients with multilevel cervical spondylotic myelopathy (CSM). METHODS: On T2-weighted magnetic resonance imaging (MRI) of the cervical spine, point A is the posteroinferior point of the spinal cord at C2, and point B is the posterosuperior point of the spinal cord at C7. The SC line is defined as a line connecting A and B. The posterior surface of the compressor at the compression level does not exceed the line in SC line type I, touches the line in type II, and exceeds the line in type III. Between January 2010 and January 2015, 121 patients with multilevel CSM who underwent surgery through an anterior approach (anterior cervical corpectomy with fusion or anterior cervical discectomy and fusion) or a posterior approach (laminoplasty or laminectomy) in our hospital were studied retrospectively. The patients were classified into 3 groups according to SC line type (I, II, or III). RESULTS: In the anterior surgical approach group, the Japanese Orthopaedic Association (JOA) recovery rate at the last follow-up was 84.88 ± 3.06% for SC line type I, 78.05 ± 2.89% for type II, and 68.69 ± 3.21% for type III. In the posterior surgical approach group, the JOA recovery rate at last follow-up was 69.35 ± 8.73% for type I, 58.05 ± 5.88% for type II, and 47.98 ± 4.31% for type III. The anterior surgery approach was associated with a higher postoperative recovery rate than the posterior surgery approach in type II and type III groups (type II anterior vs. type II posterior: 78.05 ± 2.89% vs. 58.05 ± 5.88%, P = 0.003; type III anterior vs. type III posterior: 68.69 ± 3.21% vs. 47.98 ± 4.31%, P = 0.001). In contrast, the anterior and posterior surgery were associated with similar postoperative recovery rates in the type I group (84.88 ± 3.06% vs. 69.35 ± 8.73%; P = 0.820). CONCLUSIONS: The SC line and its classifications can predict postoperative recovery in patients with multilevel CSM.

Zero-Profile Spacer Versus Cage-Plate Construct in Anterior Cervical Diskectomy and Fusion for Multilevel Cervical Spondylotic Myelopathy: Systematic Review and Meta-Analysis.

BACKGROUND: Anterior cervical diskectomy and fusion with plate-screw construct has been gradually applied for multilevel cervical spondylotic myelopathy in recent years. However, long cervical plate was associated with complications including breakage or loosening of plate and screws, trachea-esophageal injury, neurovascular injury, and postoperative dysphagia. To reduce these complications, the zero-profile spacer has been introduced. This meta-analysis was performed to compare the clinical and radiologic outcomes of zero-profile spacer versus cage-plate construct for the treatment of multilevel cervical spondylotic myelopathy. METHODS: We systematically searched MEDLINE, Springer, and Web of Science databases for relevant studies that compared the clinical and radiologic outcomes of zero-profile spacer versus cage and plate for multilevel cervical spondylotic myelopathy. Risk of bias in included studies was assessed. Pooled estimates and corresponding 95% confidence intervals were calculated. RESULTS: On the basis of predefined inclusion criteria, 7 studies with a total of 409 patients were included in this analysis. The pooled data revealed that zero-profile spacer was associated with a decreased dysphagia rate at 2, 3, and 6 months postoperatively when compared with the cage-plate group. Both techniques had similar perioperative outcomes, functional outcome, radiologic outcome, and dysphagia rate immediately and at >1-year after operation. CONCLUSIONS: On the basis of available evidence, zero-profile spacer was more effective in reducing postoperative dysphagia rate for multilevel cervical spondylotic myelopathy. Both devices were safe in anterior cervical surgeries, and they had similar efficacy in improving the functional and radiologic outcomes. More randomized controlled trials are needed to compare these 2 devices.

Cervical digit in a child: A case report.

BACKGROUND: A "digit-like" bone is a rare developmental anomaly that is usually seen in the pelvic or thoracic regions. Such an anomaly in the cervical spine is extremely rare and few cases have been reported. We present a patient with an anomalous bone posterior to a cervical vertebra. The patient was admitted to our hospital with a gradually growing hard neck mass and esthetic complaints. Physical examination, radiographs, reconstructed computed tomography, and magnetic resonance imaging revealed a digit-like bone posterior to the cervical spine. The patient was diagnosed with a "cervical digit." Through a posterior midline approach, the anomalous bone was excised because of its gradually increasing size and esthetic complaints. RESULTS: Intraoperatively, the bony mass was found to have a pseudoarticulation with the spinous process of C5 (the fifth cervical vertebra). The specimen consisted of normal bone and cartilage. The child returned to a normal life postoperatively with no symptoms. There was no recurrence at the 2-year follow-up. CONCLUSION: A congenital cervical digit is a rare deformity. A detailed clinical workup and advanced imaging examinations are useful for diagnosing such conditions. Esthetic complaints contribute to surgical indications. This is the first cervical digit managed with surgical excision of the anomalous bone and had a favorable outcome.