Glucocorticoid-loaded pH/ROS Dual-Responsive Nanoparticles Alleviate Joint Destruction by Downregulating the NF-κB Signaling Pathway

Rheumatoid arthritis (RA) is an autoimmune disease causing severe symptoms that are difficult to treat. Nano-drug delivery system is recognized as a promising strategy for management of RA. However, how to thoroughly release payloads from nanoformulations and synergistic therapy of RA needs to be further investigated. To address this issue, a pH and reactive oxygen species (ROS) dual-responsive, methylprednisolone (MPS)-loaded and arginine-glycine-aspartic acid (RGD)-modified nanoparticles (NPs) were fabricated using phytochemical and ROS-responsive moiety co-modified α-cyclodextrin (α-CD) as a carrier. In vitro and in vivo experiments verified that the pH/ROS dual-responsive nanomedicine could be efficiently internalized by activated macrophages and synovial cells, and the released MPS could promote transformation of M1-type macrophages into M2 phenotype, thereby down-regulating pro-inflammatory cytokines. In vivo experiments demonstrated that the pH/ROS dual-responsive nanomedicine was remarkably accumulated in the inflamed joints of mice with collagen-induced arthritis (CIA). The accumulated nanomedicine could obviously relieve joint swelling and cartilage destruction without obvious adverse effects. Importantly, the expression of interleukin-6 and tumor necrosis factor-α in the joints of CIA mice were significantly inhibited by the pH/ROS dual-responsive nanomedicine in comparison with free drug and non-targeted counterparts. In addition, the expression of the NF-κB signaling pathway molecules P65 was also significantly decreased by nanomedicine-treatment. Our results reveal that MPS-loaded pH/ROS dual-responsive NPs can effectively alleviate joint destruction via down-regulation of the NF-κB signaling pathway. STATEMENT OF SIGNIFICANCE: Nanomedicine is recognized as an attractive method for the targeting treatment of rheumatoid arthritis (RA). To thorough release of payloads from nanoformulations and synergistic therapy of RA, herein, a phytochemical and ROS-responsive moiety co-modified α-cyclodextrin was used as a pH/ROS dual-responsive carrier to encapsulate methylprednisolone to manage RA. The fabricated nanomedicine can effectively release its payloads under pH and/or ROS microenvironment, and the released drugs dramatically promote transformation of M1-type macrophages into M2 phenotype to reduce the release of pro-inflammatory cytokines. The prepared nanomedicine also obviously decreased the NF-κB signaling pathway molecule P65 expression in the joints, thereby down-regulating pro-inflammatory cytokines expression to alleviate joint swelling and cartilage destruction. We provided a candidate for the targeting treatment of RA.

Embryonal rhabdomyosarcoma of oropharynx in a 65-year-old male with indolent clinical presentation and unusual morphology

Introduction/Objective

Embryonal rhabdomyosarcoma (ERMS) is a malignant primitive mesenchymal tumor which commonly affects children and adolescence. Although head and neck area is a common location for ERMS, oropharynx is rarely involved. ERMS in adults often present with stage IV disease and show a relatively poor prognosis. Loss of heterozygosity in 11p15.5 is one of the common genetic findings in sporadic ERMS.

Methods/Case Report

A 65-year-old male with no significant medical history, presented with pharyngodynia and was found to have a polypoid mass originating from the pharyngeal surface of the soft palate and extends into the vallecula. He reported having this mass for a decade and having intermittent episodes of similar oropharyngeal symptoms which were usually resolved with antibiotics.

Results (if a Case Study enter NA)

Excisional biopsy shows a 2.4 cm polypoid mass with atypical cellular proliferation in submucosa. Tumor cells demonstrate ovoid to round nuclei and eosinophilic cytoplasm. No mitotic figure was found and Ki67 proliferation index was extremely low (<1%). Immunostains showed that the tumor cells are positive for Desmin and MyoD1. Scattered cells are positive for Myogenin. Due to the unusual clinical presentation and low proliferation activity, late onset of fetal rhabdomyoma was also considered in the differential diagnosis. The specimen was sent for chromosomal microarray which showed chromosomal gains and losses including loss of heterozygosity in chromosome 11. This finding together with cytologic atypia are mostly compatible with the diagnosis of ERMS. Post-biopsy MRI and PET-CT did not reveal any residual disease or distant metastasis. Patient has been followed up for 6 months after biopsy with no sign of recurrence.

Conclusion

Our case indicates that ERMS in adult can present with an indolent clinical process and low proliferating activity. Diagnosis can be challenging in this scenario. Chromosomal microarray is a useful tool to help confirm the diagnosis.

Mass-forming chronic invasive fungal sinusitis; an uncommon mimicker of head & neck malignancy

Introduction/Objective

Invasive fungal sinusitis is a progressive infection affecting the nasal cavity and associated sinus spaces. Acute forms affect immunocompromised patients with debilitating systemic diseases while chronic forms usually occur in immunocompetent individuals.

Methods/Case Report

A 26-year-old immunocompetent male with daily Marijuana smoking consulted for acute swelling of the right eye with dull pain, photophobia, loss of vision and pressure of 4 day duration. He reported nasal congestion for approximately one year and over the previous 2 months developed exophthalmos. Imaging demonstrated a 4.9 x 4.3 x 4.1 cm invasive soft tissue mass in the right lamina papyracea with involvement of the paranasal sinus, right orbit, and intracranial space. The mass was presumed to represent a high-grade malignancy.

Biopsy was performed and demonstrated granulomatous invasive fungal sinusitis. The patient underwent right orbitotomy and right extranasal ethmoidectomy. He was begun on empiric amphotericin B. After culture and sequencing identification of Curvularia species, voriconazole was added. Follow up imaging studies after two month of treatment still demonstrated residual mass forming lesion with 10-20% decrease in size. The patient has regained his vision after 4 month of treatment and he is expected to complete a six months course. If the mass forming lesion persists, a second round of surgical debridement will be performed.

Results (if a Case Study enter NA)

N/A

Conclusion

Curvularia is a dematiaceous fungus most commonly associated with allergic sinusitis, but can rarely become invasive in immunocompetent individuals. Histopathologically large fungal elements are easily recognizable but specific identification requires culture or ribosomal DNA sequencing by PCR. Mass-forming chronic fungal sinusitis overlaps clinically and radiologically with head and neck malignancies. Our report brings attention to this uncommon clinical variant of invasive fungal sinusitis that affects immunocompetent individuals.

Amyloid deposition in oral cavity and larynx, a single institute experience

Introduction/Objective

Amyloidosis is characterized by extracellular accumulation of insoluble amyloid fibril. Amyloid deposition in the head and neck area is rare.

Methods/Case Report

In this study, we reviewed 34 specimens from 26 patients including: 18 specimens from the larynx and/or pharynx (13 patients) and 16 specimens from the oral cavity (13 patients). The clinical presentation, related laboratory results, and pathologic finding were reviewed.

Results (if a Case Study enter NA)

Within the 18 laryngeal specimens were: 10 glottic, 4 supraglottic, 3 nasopharyngeal or pharyngeal wall, and 1 subglottic. Of the 16 cases from oral cavity there were 9 lingual, 3 labial, 2 palatine, 1 tonsillar, and 1 alveolar ridge. Ten out of 13 patients with laryngeal amyloid deposition had protein electrophoresis performed and only 3 of the patients had monoclonal light chain detected. Among these three patients, one had multiple myeloma, one had lymphoplasmacytic lymphoma and one had the diagnosis of plasma cell dyscrasia. Interestingly, in the patients with oral cavity amyloidosis, 10 out of 11 patients tested had abnormal findings. Six of the patients had monoclonal light chain, two demonstrated monoclonal peak of IgG kappa, one with IgG lambda and one with IgA lambda. Among these 10 patients, 6 of them had biopsy-proved or history of multiple myeloma, one patient had marginal zone lymphoma, two patients had systematic amyloidosis. Only one patient did not have any malignancy or systematic involvement identified.

Conclusion

In our small cohort, the most common location of amyloid deposition in the larynx is glottis. When it involves the oral cavity, tongue is the most common location. Compared to the larynx, amyloid deposition in the oral cavity tends to be associated with hematopoietic malignancy or systematic involvement, although this finding needs to be confirmed by a larger scale of study.

Cell-free DNA from bile outperformed plasma as a potential alternative to tissue biopsy in biliary tract cancer

BACKGROUND

Biliary tract cancers (BTCs) are rare and highly heterogenous malignant neoplasms. Because obtaining BTC tissues is challenging, the purpose of this study was to explore the potential roles of bile as a liquid biopsy medium in patients with BTC.

PATIENTS AND METHODS

Sixty-nine consecutive patients with suspected BTC were prospectively enrolled in this study. Capture-based targeted sequencing was performed on tumor tissues, whole blood cells, plasma, and bile samples using a large panel consisting of 520 cancer-related genes.

RESULTS

Of the 28 patients enrolled in this cohort, tumor tissues were available in eight patients, and plasma and bile were available in 28 patients. Somatic mutations were detected in 100% (8/8), 71.4% (20/28), and 53.6% (15/28) of samples comprising tumor tissue DNA, bile cell-free DNA (cfDNA), and plasma cfDNA, respectively. Bile cfDNA showed a significantly higher maximum allele frequency than plasma cfDNA (P = 0.0032). There were 56.2% of somatic single-nucleotide variant (SNVs)/insertions and deletions (indels) shared between bile and plasma cfDNA. When considering the genetic profiles of tumor tissues as the gold standard, the by-variant sensitivity and positive predictive value for SNVs/indels in bile cfDNA positive for somatic mutations were both 95.5%. The overall concordance for SNVs/indels in bile was significantly higher than that in plasma (99.1% versus 78.3%, P < 0.0001). Moreover, the sensitivity of CA 19-9 combined with bile cfDNA achieved 96.4% in BTC diagnosis.

CONCLUSION

We demonstrated that bile cfDNA was superior to plasma cfDNA in the detection of tumor-related genomic alterations. Bile cfDNA as a minimally invasive liquid biopsy medium might be a supplemental approach to confirm BTC diagnosis.

[Expression profile of intervertebral disc degeneration-specific genes: a transcriptome sequencing-based analysis]

OBJECTIVE

To identify new therapeutic targets for intervertebral disc degeneration (IDD) by analyzing gene variations in IDD.

OBJECTIVE

We analyzed surgical samples of intervertebral disc from 4 patients with IDD and 3 patients with non-IDD using RNA sequencing (RNA-seq) technology to identify significant differentially expressed genes (DEGs) in IDD. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases were utilized for gene enrichment studies to acquire the key genes and signal pathways during IDD progression. The differential expressions of the identified genes in IDD were validated in clinical samples with qRT-PCR.

OBJECTIVE

The transcriptome profile revealed 512 significant DEGs, which were enriched in terms of keratinization, extracellular matrix (ECM) components, growth factor binding, and inflammatory chemotaxis in GO analysis. The top 10 terms of KEGG enrichment included amoebiasis, viral protein interaction with cytokine and cytokine receptor, ECM-receptor interaction, IL-17 signaling pathway, cytokine-cytokine receptor interaction, TNF signaling pathway, AGE-RAGE signaling pathway in diabetic complications, PI3K-Akt signaling pathway, chemokine signaling pathway and estrogen signaling pathway. Thirteen DEGs selected as the targets for qRT-PCR validation showed significant differential expressions in IDD (P < 0.001), and their expression trends were all consistent with the results of RNA-seq. Among these genes, 10 genes showed significant intergroup fold change (Log2FoldChange>1).

OBJECTIVE

ECM, growth factors, collagen components, inflammatory chemokines and such signal pathways as TNF-α and PI3K-Akt all have important contributions to IDD progression and may thus serve as new therapeutic targets for treatment of IDD.

Comparison of Individual Tissue-Engineered Bones and Allogeneic Bone in Treating Bone Defects: A Long-Term Follow-Up Study

The treatment of bone defects has always been a challenge for orthopedic surgeons. The development of tissue engineering technology provides a novel method for repairing bone defects and has been used in animal experiments and clinical trials. However, there are few clinical studies on comparing the long-term outcomes of tissue-engineered bones (TEBs) and other bone grafts in treating bone defects, and the long-term efficiency of TEBs remains controversial. Therefore, a study designed by us was aimed to compare the long-term efficacy and safety of individual tissue-engineered bones (iTEBs) and allogeneic bone granules (ABGs) in treating bone defects caused by curettage of benign bone tumors and tumor-like lesions. From September 2003 to November 2009, 48 patients who received tumor curettage and bone grafting were analyzed with a mean follow-up of 122 mo (range 60 to 173 mo). Based on implant style, patients were divided into groups of iTEBs (n = 23) and ABGs (n = 25). Postoperatively, the healing time, healing quality, incidence of complications, and functional scores were compared between the two groups. The Musculoskeletal Tumor Society functional evaluation system and Activities of Daily Living Scale scores were significantly improved in both groups with no significant difference. The average healing time of ABGs was longer than that of iTEBs (P < 0.05). At the final follow-up, iTEBs had a better performance in the bone healing quality evaluated by modified Neer classification (P < 0.05). In the group of iTEBs, the complication and reoperation rate was lower than that in the group of ABGs, with no tumorigenesis or immune rejection observed. In summary, for treating bone defects caused by tumor curettage, iTEBs were safe, effective, and tagged with more rapid healing speed, better healing outcome, and lower complication and reoperation rate, in comparison with ABGs.

Tricortical iliac crest allograft with anterolateral single rod screw instrumentation in the treatment of thoracic and lumbar spinal tuberculosis

To assess the effectiveness of tricortical iliac crest allografts with anterolateral instrumentation after single-stage surgery for thoracic and lumbar spinal tuberculosis (TB). Fifty-six patients with thoracic and lumbar spinal TB underwent single-stage anterior radical debridement, interbody fusion with tricortical iliac crest allografts and anterolateral single rod instrumentation. All patients were given 18 months of antituberculosis chemotherapy. The patients were followed up regularly, and their clinical manifestations, roentgenogram results, erythrocyte sedimentation rate (ESR) and liver function test were the results to be concerned. Radiographs were analysed before surgery, immediately after surgery, and at the final follow-up examination. Mean follow-up period was 37.5 months in 52 patients, and 4 patients were lost to follow-up. No patients had superficial wound infections, and all the incisions healed within 2 weeks. No graft fracture, collapse, or sliding was observed. The average bony fusion time was 10.6 months. Bony fusion was observed in all 52 patients within 18 months. The average degrees of kyphotic correction loss for thoracic and lumbar spine were 6.71° and 2.78° respectively. Although it took a long time to achieve solid fusion, tricortical iliac crest allografts were found to be convenient and safe to be used in spinal TB surgery. They may be effective options for interbody fusion, deformity correction and correction maintenance with anterolateral single rod instrumentation.

Modification of PLGA Scaffold by MSC-Derived Extracellular Matrix Combats Macrophage Inflammation to Initiate Bone Regeneration via TGF-β-Induced Protein

The immunologic response toward chronic inflammation or bone regeneration via the accumulation of M1 or M2 macrophages after injury could determine the fate of biomaterial. Human umbilical cord mesenchymal stem cells (hUCMSCs) have a pivotal immunomodulatory property on directing macrophage behaviors. Herein, for the first time, 3D-printed poly(lactide-co-glycolide) (PLGA) scaffolds modified with hUCMSC-derived extracellular matrix (PLGA-ECM) are prepared by a facile tissue engineering technique with physical decellularization and 2.44 ± 0.29 mg cm^-3 proteins immobilized on the PLGA-ECM contain multiple soluble cytokines with a sustainable release profile. The PLGA-ECM not only attenuates the foreign body response, but also improves bone regeneration by increasing the accumulation of M2 macrophages in an improved heterotopic transplantation model of SCID mice. Furthermore, the PLGA-ECM scaffolds with the knockdown of transforming growth factor-β-induced protein (TGFβI/βig-H3) demonstrate that M2 macrophage accumulation improved by the PLGA-ECM could be attributed to increasing the migration of M2 macrophages and the repolarization of M1 macrophages to M2 phenotype, which are mediated by multiple integrin signaling pathways involving in integrin β7, integrin α9, and integrin β1 in a TGFβI-dependent manner. This study presents an effective surface modification strategy of polymeric scaffolds to initiate tissue regeneration and combat inflammatory response by increasing M2 macrophage accumulation.

Transforaminal debridement with a posterior-only approach involving placement of an interbody bone graft combined with diseased vertebral fixation for the treatment of thoracic and lumbar tuberculosis: Minimum 5-year follow-up

The aim of this study was to evaluate the clinical and imaging results of transforaminal debridement with a posterior-only approach involving placement of an interbody bone graft combined with diseased vertebral fixation for the treatment of thoracic and lumbar tuberculosis (TB) with a minimum 5-year follow-up.Sixty-five patients who presented with active thoracic and lumbar TB between October 2006 and August 2013 were retrospectively analyzed: 20 were thoracic TB (group A), 17 were thoracolumbar TB (group B), and 28 were lumbar TB (group C). The patient data, operating time, blood loss, Visual Analog Scale score, Oswestry Disability Index score, correction of kyphosis, recovery of neurological function, and complications were recorded and analyzed.The patients were followed for 68.7 ± 17.8 months. The preoperative average Cobb angles of kyphosis in patients in groups A, B, and C significantly decreased from 28.2 ± 11.9°, 30.5 ± 16.9°, and 10.9 ± 8.8° before surgery to 8.0 ± 5.4°, 5.0 ± 4.1°, and -4.4 ± 1.6° (- indicates lordosis) after surgery, respectively. At the final follow-up time, the Cobb angles were 9.2 ± 6.1°, 6.8 ± 10.0°, and -3.7 ± 2.0°, respectively. The postoperative Cobb angles of kyphosis were significantly improved in all groups (P < .05). The correction loss angles were larger in groups A and B than in group C (P > .05). The operating time, blood loss, and complications were not significantly different between the groups (P > .05). Three (4.6%) patients developed unhealed TB during postoperative anti-TB treatment, and 6 patients (9.2%) with TB relapsed after healing from surgery.The posterior-only approach for the surgical treatment of thoracic and lumbar TB achieved satisfactory outcomes over long-term follow-up. The implantation of pedicle screws in diseased vertebrae reduced the range of fixation, but patients with thoracic and thoracolumbar TB should undergo fixation to at least 1 adjacent normal segment. There were some cases of recurrence after TB healed, and long-term follow-up is therefore necessary.

The clinical use of the enriched bone marrow obtained by selective cell retention technology in treating adolescent idiopathic scoliosis

Purpose

This retrospective study aimed to evaluate the curative effect of allografts in combination with bone marrow enrichment realised by selective cell retention (SCR) technology in treating adolescent idiopathic scoliosis (AIS).

Methods

From July 2014 to September 2016, 18 consecutive patients with AIS were treated by posterior fusion and pedicle screw instrumentation. Bone marrow aspirates were obtained and enriched by SCR technology to fabricate bone grafts in combination with allogeneic bones, which were implanted for spinal fusion. Postoperatively, the patients were observed for a minimum of 18 months, with a mean follow-up period of 48 months. The results were assessed both clinically and radiographically. All adverse events and complications were recorded.

Results

A total of 9 male and 9 female patients were included, with an average age of 15.6 years (range, 12–20). The average preoperative Cobb angle was 56° (range, 47°–85°). The average number of levels fused was 11 (range, 9–13). SCR could be accomplished intraoperatively, only consuming approximately 20 ​min. The enriching multiples of measured cellular elements were approximately 2.3–4.2. At final follow-up, the average Cobb angle correction was 83% (range, 61–96%). There was no obvious loss in correction with an average loss of 1.1° (2%). The visual analogue scale score and the Oswestry Disability Index score at final follow-up were significantly ameliorated than those preoperatively. The Scoliosis Research Society 30 questionnaire revealed remarkable improvement in the domains “pain”, “self-image/appearance”, and “satisfaction with management”. There was neither pseudarthrosis nor severe complication.

Conclusion

The use of SCR technology could be considered as an effective method for promoting spinal fusion in treating AIS. We proposed a safe, simple, and rapid approach to obtain effective bone grafts for spinal fusion.

The translational potential of this article

Enriched bone marrow obtained by selective cell retention technology has the potential to promote spinal fusion for the treatment of adolescent idiopathic scoliosis.

Individual Tissue-Engineered Bone in Repairing Bone Defects: A 10-Year Follow-Up Study

Bone defects caused by various causes remain a major problem in orthopedic clinics. A number of different treatments have been developed and proposed, but until now, none has proven to be completely satisfactory. For 26 patients with bone defects but limited autologous bone source or allogeneic bone graft failure, we used individual tissue-engineered bones (iTEBs) for repairing, which were constructed by autologous bone marrow mesenchymal stem cells and allogenic decalcified bone matrix (DBM) scaffolds. The clinical outcomes, including efficacy and safety, were evaluated by radiological examinations, postoperative function recovery score and laboratory tests. Twenty-six patients, including 18 men and 8 women, were followed up for an average of 10 years to analyze the long-term outcome. The mean healing time for patients with lacunar bone defects was 3.87 ± 2.01 months (range, 2-9 months) and that for structural bone defects was longer than 12 months. The Musculoskeletal Tumor Society functional evaluation system and the Barthel Index scores were significantly improved during the long-term follow-up. The white blood cell, erythrocyte sedimentation rate, C reactive protein, complement, immunoglobulins, and liver and renal functions were not significantly affected by bone grafting. One patient with bone cyst relapsed at 3 years postoperatively and achieved bone healing after re-transplantation. No tumorigenesis, tumor metastasis, or blood transmissible disease was found in the whole process. The results demonstrated that iTEBs were effective and safe for repairing bone defects in the long period, especially for those with lacunar bone defects and limited autograft source. Impact statement Currently, controversies exist about the long-term safety and effectiveness of the clinical application of tissue-engineered bones (TEBs) due to potential tumorigenesis, immune rejection, disease transmission, and others. In this study, we show that individual TEBs constructed by autologous MSCs and allogenic decalcified bone matrix are reliable for repairing bone defects in regard to its long-term safety and effectiveness. Our study provides experience and basis about the clinical application of TEBs in the treatment of bone defects.

A Standardized and Quality-Controllable Protocol of Constructing Individual Tissue-Engineered Grafts Applicable to Treating Large Bone Defects

Patient-specific individual tissue-engineered bones (iTEBs) have been recognized as a promising strategy for treating large bone defects. However, current construction protocols of iTEBs vary between lots and lack standardization and quality control, hampering further research and application. This study was aimed to detail a standardized constructing protocol for iTEBs, which can be used for both clinical and experimental purposes. The procedure was designed and described as follows: scaffold preparation, cell isolation and culture, and fabrication of iTEBs. Manipulation and caution points in each section were detailed. A series of scales on the quality control and safety monitoring was developed. The effectiveness and safety of iTEBs were evaluated. Eventually, the preparing portion, from cell culture to scaffold treatment, usually required 21 days. Generally, the fabrication section took 5 days. The main advantage of this protocol was that each step was standardized and quality controlling and safety monitoring were performed throughout the process to ensure the homogeneity, reliability, and safety. The resulting iTEBs were effective and applicable to both clinical and experimental purposes. Thus, we have established a refined and standardized protocol detailing the construction process of patient-specific iTEBs that comply with strict quality control and safety criteria. This protocol is relatively easy for graduate students or staff working in the field of bone tissue engineering to implement.

EPC-derived exosomes promote osteoclastogenesis through LncRNA-MALAT1

Bone repair involves bone resorption through osteoclastogenesis and the stimulation of neovascularization and osteogenesis by endothelial progenitor cells (EPCs). However, the role of EPCs in osteoclastogenesis is unclear. In this study, we assess the effects of EPC-derived exosomes on the migration and osteoclastic differentiation of primary mouse bone marrow-derived macrophages (BMMs) in vitro using immunofluorescence, western blotting, RT-PCR and Transwell assays. We also evaluated the effects of EPC-derived exosomes on the homing and osteoclastic differentiation of transplanted BMMs in a mouse bone fracture model in vivo. We found that EPCs cultured with BMMs secreted exosomes into the medium and, compared with EPCs, exosomes had a higher expression level of LncRNA-MALAT1. We confirmed that LncRNA-MALAT1 directly binds to miR-124 to negatively control miR-124 activity. Moreover, overexpression of miR-124 could reverse the migration and osteoclastic differentiation of BMMs induced by EPC-derived exosomes. A dual-luciferase reporter assay indicated that the integrin ITGB1 is the target of miR-124. Mice treated with EPC-derived exosome-BMM co-transplantations exhibited increased neovascularization at the fracture site and enhanced fracture healing compared with those treated with BMMs alone. Overall, our results suggest that EPC-derived exosomes can promote bone repair by enhancing recruitment and differentiation of osteoclast precursors through LncRNA-MALAT1.

Can a posterior approach effectively heal thoracic and lumbar tuberculosis? Microbiology outcomes of the operative area

Background

There was a controversy about surgery approach of thoracic and lumbar tuberculosis (TB) treatment. The aim of this study was to compare the microbiology outcomes of the drainage liquid and the clinical outcomes of a posterior and anterior approach in the treatment of thoracic and lumbar TB.

Materials and methods

A total of 105 patients were enrolled in this prospective study from February 2011 to September 2015. Patients were divided into two groups: group A (51 patients, posterior approach surgery) and group B (54 patients, anterior approach surgery). Intraoperative TB samples were sent for Mycobacterium tuberculosis culture (MTBC). Drainage fluid was postoperatively collected for polymerase chain reaction (PCR), acid-fast strains (AFS), MTBC, and DNA molecular detection (DNAMD) analyses. Compare the drainage liquid positive rate of the two groups and estimate relationship between the positive results of drainage fluid and the lesion region. In addition, the clinical outcomes including the bony fusion, relapse rate, complications, and neurological status were collected.

Results

There was no significant difference in the positive rate of AFS, PCR, DNAMD, MTBC, or any positive rate (APR) of drainage liquid between the two groups (P > 0.05). In both groups, the MTBC-positive rate of postoperative drainage fluid was significantly lower than that of the intraoperative sample (P < 0.01). There was no significant relationship between APR and the lesion region (P > 0.05). All the patients had at least 2 years of follow-up, with an average of 34.4 ± 15.8 months. There were four patients in group A and two patients in group B who had recurrent spine TB, and the rest of the patients had fusion in the surgical area. There was no significant difference in the incidence of TB recurrence or other complications between the two groups (P > 0.05). All the patients with neurological dysfunction had improved after surgery.

Conclusion

Compared with anterior approach surgery, posterior approach surgery had equal effectiveness of debridement. The two kinds of surgery can effectively clear the lesions surrounding the spine and heal thoracic and lumbar TB.

Multiple parameters for evaluating posterior longitudinal ligaments in thoracolumbar burst fractures

BACKGROUND

The posterior longitudinal ligament plays a key role in spinal stability. The purpose of this study was to determine the injuries of the posterior longitudinal ligament (PLL) in thoracolumbar burst fractures.

PATIENTS AND METHODS

Patients suffering a thoracolumbar burst fracture from January 2011 to December 2015 were divided into an intact group and a disrupted group according to the status of the PLL. Mid-sagittal canal diameter, width and height of bone fragments, inversion angle and horizontal rotation angle of bone fragments and local kyphosis angle were measured. Anterior, middle and posterior vertebrae compression ratio, mid-sagittal diameter compression ratio, ratio of height of bone fragments occupying the posterior wall of the injured vertebral body and ratio of the width of bone fragment occupying the transverse canal diameter were calculated.

RESULTS

A total of 95 patients were included in the study including 52 patients in the intact group and 43 patients in the disrupted group. There were significant differences on anterior and posterior vertebrae compression ratio, mid-sagittal diameter compression ratio, inversion angle and horizontal rotation angle of bone fragment (P  0.05) between the two groups. Injury of the PLL showed a positive correlation with the mid-sagittal diameter compression ratio and inversion angle of bone fragment (P  0.05).

CONCLUSION

The mid-sagittal diameter compression ratio and inversion angle of bone fragment can be used to assess the status of the PLL in thoracolumbar burst fractures. When the mid-sagittal diameter compression ratio was 52% and the inversion angle of the bone fragment was 33° the PLL was likely to be disrupted.

Endothelial Progenitor Cells Enhance the Migration and Osteoclastic Differentiation of Bone Marrow-Derived Macrophages in vitro and in a Mouse Femur Fracture Model through Talin-1

BACKGROUND/AIMS

Bone resorption mediated by osteoclasts plays an important role in bone healing. Endothelial progenitor cells (EPCs) promote bone repair by stimulating neovascularization and osteogenesis. However, the role of EPCs in osteoclast formation and function is not well defined. The aim of this study was to elucidate mechanisms of EPCs in osteoclast formation and function.

METHODS

In this study, we examined the effects of EPCs on the proliferation, migration and osteoclastic differentiation of primary mouse bone marrow-derived macrophages (BMMs) in a co-culture system in vitro. We also evaluated the effects of EPC co-transplantation on the homing and osteoclastic differentiation of transplanted BMMs in a mouse bone fracture model in vivo. The technology of immunofluorescence, immunohistochemical, western blot, Rt-PCR, cell co-culture and Transwell were used in this study.

RESULTS

EPCs secreted TGF-β1 in the EPC-BMM co-culture medium and increased Talin-1 expression in the co-cultured BMMs. Treatment with a TGF-β1 neutralizing antibody or Talin-1 silencing in BMMs completely inhibited BMM osteoclastic differentiation in the co-culture system. These results indicated that the osteoclastogenic effects of EPCs were mediated by TGF-β1-mediated Talin-1 expression in BMMs. In the femur fracture model, BMMs co-transplanted with EPCs exhibited enhanced engraftment into the fracture site and osteoclastic differentiation compared with those transplanted alone. Mice treated with EPC-BMM co-transplantation exhibited increased neovascularization at the fracture site and accelerated fracture healing compared with those treated with BMMs alone.

CONCLUSION

Taken together, the results suggest that EPCs can promote bone repair by enhancing recruitment and differentiation of osteoclast precursors.

1,25(OH)2D3 suppresses proinflammatory responses by inhibiting Th1 cell differentiation and cytokine production through the JAK/STAT pathway

1,25(OH)₂D₃ is an immune modulation hormone with beneficial effects on T cell- mediated autoimmune diseases. The purpose of the present study is to investigate the direct effects of vitamin D on Bacillus Calmette Guerin (BCG)-infected CD4+ T cells in both VDR-deficient (VDR-/-) mice and wild type (WT) mice. Specifically, we aimed to investigate the effect of vitamin D on Th1 cells and elucidate the underlying molecular mechanism. Naïve CD4 T cells were purified from VDR-/- mice and WT mice to induce Th1 cells and were activated by BCG. Th1 cell differentiation and cytokine production in vitro were inhibited by 10 nM 1,25(OH)₂D₃. The JAK/STAT pathway was activated by 1,25(OH)₂D₃ addition in both VDR-/- and wild type T cells. In vivo, a vitamin D-deficiency VDR-/- and WT mouse model was established and the mice were vaccinated with BCG. An ELISA assay was performed to measure the levels of VD, IL-2, IFN-γ and TNF-β in the blood, and flow cytometry was used to analyze the proportion of Th1 and Th2 cells in the spleen. 1,25(OH)₂D₃ affected Th cells polarization by inhibiting Th1 and augmenting Th2 cell development in the vitamin D-deficiency mouse model. Moreover, 1,25(OH)₂D₃ inhibited the inflammatory infiltrates and expression of IL-2, IFN-γ and TNF-β in the spleen of vitamin D-deficient mice following vaccination with BCG. These findings suggested that 1,25(OH)₂D₃ suppressed the inflammatory response by inhibiting Th1 cell differentiation and cytokine production by the JAK/STAT pathway.

IL-8 Enhances Therapeutic Effects of BMSCs on Bone Regeneration via CXCR2-Mediated PI3k/Akt Signaling Pathway

BACKGROUND/AIMS

Tissue engineering bone transplantation with bone marrow mesenchymal stem cells (BMSCs) is an effective technology to treat massive bone loss, while molecular regulation of the bone regeneration processes remains poorly understood. Here, we aimed to assess the role of interleukin-8 (IL-8) in the recruitment of host cells by seeded BMSCs and in the bone regeneration.

METHODS

A transwell assay was performed to examine the role of IL-8/CXCR1/CXCR2/PI3k/Akt on the migration potential of hBMSCs. The in vitro chondrogenic differentiation of hBMSCs was assessed by examination of 2 chondrogenic markers, Sox9 and type 2 collagen (COL2). mBMSCs were used in tissue engineered bone (TEB) with/without IL-8 implanted into bone defect area with CXCR2 or Akt inhibitors. Density and Masson staining of the regenerated bone were assessed. The chondrogenesis was assessed by expression levels of associated proteins, Sox9 and COL2, by RT-qPCR and by immunohistochemistry.

RESULTS

IL-8 may trigger in vitro migration of hBMSCs via CXCR2-mediated PI3k/Akt signaling pathway. IL-8 enhances osteogenesis in the TEB-implanted bone defect in mice. IL-8 induces chondrogenic differentiation of hBMSCs via CXCR2-mediated PI3k/Akt signaling pathway in vitro and in vivo.

CONCLUSIONS

IL-8 enhances therapeutic effects of MSCs on bone regeneration via CXCR2-mediated PI3k/Akt signaling pathway.

Estrogen Deficiency-Mediated M2 Macrophage Osteoclastogenesis Contributes to M1/M2 Ratio Alteration in Ovariectomized Osteoporotic Mice

In this study, for the first time we discovered that the M1/M2 macrophage phenotype ratio is increased in bone marrow of ovariectomized (OVX) osteoporotic C57BL/6 mice. Considering estrogen is the main variable, we assumed that estrogen participated in this alteration. To determine whether and how estrogen contributes to the change of the M1/M2 ratio, we first isolated bone marrow macrophages (BMMs) from mice femur and stimulated the cells with lipopolysaccharide (LPS)/interferon γ (IFN-γ) for M1 polarization and interleukin 4 (IL-4)/IL-13 for M2 polarization. M1 and M2 macrophages were then exposed to RANKL stimulation, we found that M2 macrophage but not M1 macrophage differentiated into functional osteoclast leading to increased M1/M2 ratio. Intriguingly, 17β-estradiol (E2) pretreatment prevented osteoclastogenesis from M2 macrophages. By constructing shRNA lentivirus interfering the expression of different estrogen receptors in M2 macrophages, we found that estrogen protects M2 macrophage from receptor activator of nuclear factor κB ligand (RANKL) stimulation selectively through estrogen receptor α (ERα) and the downstream blockage of NF-κB p65 nuclear translocation. Animal studies showed that ERα selective agonist 4,4',4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl) trisphenol (PPT) was able to replicate the therapeutic effects of E2 in treating osteoporotic OVX mice. Together, our findings reveal that estrogen deficiency-mediated M2 macrophage osteoclastogenesis leads to increased M1/M2 ratio in OVX mice. Reducing the M1/M2 ratio is a potential therapeutic target in treating postmenopausal osteoporosis. © 2017 American Society for Bone and Mineral Research.

IGFBP3 deposited in the human umbilical cord mesenchymal stem cell-secreted extracellular matrix promotes bone formation

The extracellular matrix (ECM) contains rich biological cues for cell recruitment, proliferationm, and even differentiation. The osteoinductive potential of scaffolds could be enhanced through human bone marrow mesenchymal stem cell (hBMSC) directly depositing ECM on surface of scaffolds. However, the role and mechanism of human umbilical cord mesenchymal stem cells (hUCMSC)-secreted ECM in bone formation remain unknown. We tested the osteoinductive properties of a hUCMSC-secreted ECM construct (hUCMSC-ECM) in a large femur defect of a severe combined immunodeficiency (SCID) mouse model. The hUCMSC-ECM improved the colonization of endogenous MSCs and bone regeneration, similar to the hUCMSC-seeded scaffold and superior to the scaffold substrate. Besides, the hUCMSC-ECM enhanced the promigratory molecular expressions of the homing cells, including CCR2 and TβRI. Furthermore, the hUCMSC-ECM increased the number of migrated MSCs by nearly 3.3 ± 0.1-fold, relative to the scaffold substrate. As the most abundant cytokine deposited in the hUCMSC-ECM, insulin-like growth factor binding protein 3 (IGFBP3) promoted hBMSC migration in the TβRI/II- and CCR2-dependent mechanisms. The hUCMSC-ECM integrating shRNA-mediated silencing of Igfbp3 that down-regulated IGFBP3 expression by approximately 60%, reduced the number of migrated hBMSCs by 47%. In vivo, the hUCMSC-ECM recruited 10-fold more endogenous MSCs to initiate bone formation compared to the scaffold substrate. The knock-down of Igfbp3 in the hUCMSC-ECM inhibited nearly 60% of MSC homing and bone regeneration capacity. This research demonstrates that IGFBP3 is an important MSC homing molecule and the therapeutic potential of hUCMSC-ECM in bone regeneration is enhanced by improving MSC homing in an IGFBP3-dependent mechanism.

Graphene-Based MicroRNA Transfection Blocks Preosteoclast Fusion to Increase Bone Formation and Vascularization

The objective of this study is to design a graphene-based miRNA transfection drug delivery system for antiresorptive therapy. An efficient nonviral gene delivery system is developed using polyethylenimine (PEI) functionalized graphene oxide (GO) complex loaded with miR-7b overexpression plasmid. GO-PEI complex exhibits excellent transfection efficiency within the acceptable range of cytotoxicity. The overexpression of miR-7b after GO-PEI-miR-7b transfection significantly abrogates osteoclast (OC) fusion and bone resorption activity by hampering the expression of an essential fusogenic molecule dendritic cell-specific transmembrane protein. However, osteoclastogenesis occurs without cell-cell fusion and preosteoclast (POC) is preserved. Through preservation of POC, GO-PEI-miR-7b transfection promotes mesenchymal stem cell osteogenesis and endothelial progenitor cells angiogenesis in the coculture system. Platelet-derived growth factor-BB secreted by POC is increased by GO-PEI-miR-7b both in vitro and in vivo. In treating osteoporotic ovariectomized mice, GO-PEI-miR-7b significantly enhances bone mineral density, bone volume as well as bone vascularization through increasing CD31^hiEmcn^hi cell number. This study provides a cell-cell fusion targeted miRNA transfection drug delivery strategy in treating bone disorders with excessive osteoclastic bone resorption.

H9N2 influenza virus isolated from minks has enhanced virulence in mice

H9N2 is one of the major subtypes of influenza virus circulating in poultry in China, which has a wide host range from bird to mammals. Two H9N2 viruses were isolated from one mink farm in 2014. Phylogenetic analysis showed that internal genes of the H9N2 viruses have close relationship with those of H7N9 viruses. Interestingly, two H9N2 were separated in phylogenetic trees, indicating that they are introduced to this mink farm in two independent events. And further mice studies showed that one H9N2 caused obvious weight loss and 20% mortality in infected mice, while another virus did not cause any clinical sign in mice infected at the same dose. Genetic analysis indicated that the virulent H9N2 contain a natural mutation at 701N in PB2 protein, which was reported to contribute to mammalian adaptation. However, such substitution is absent in the H9N2 avirulent to mice. Circulation of H9N2 in mink may drive the virus to adapt mammals; continual surveillance of influenza virus in mink was warranted.

TGFβ3 recruits endogenous mesenchymal stem cells to initiate bone regeneration

Background

The recruitment of a sufficient number of endogenous mesenchymal stem cells (MSCs) is the first stage of in-situ tissue regeneration. Transforming growth factor beta-3 (TGFβ3) could recruit stem or progenitor cells and endothelial cells to participate in tissue regeneration. However, the mechanism of TGFβ3 recruiting MSCs toward bone regeneration has remained obscure.

Methods

We estimated the promigratory property of TGFβ3 on human bone marrow MSCs (hBMSCs) cocultured with the vascular cells (human umbilical artery smooth muscle cells or human umbilical vein endothelial cells) or not by Transwell assay. After the addition of the inhibitor (SB431542) or Smad3 siRNA, the levels of MCP1 and SDF1 in coculture medium were tested by ELISA kit, and then the migratory signaling pathway of hBMSCs induced by TGFβ3 was investigated by western blot analysis. In vivo, a 2-mm FVB/N mouse femur defect model was used to evaluate chemokine secretion, endogenous cell homing, and bone regeneration induced by scaffolds loading 1 μg TGFβ3 through qPCR, immunofluorescent staining, immunohistochemical analysis, and Micro-CT, compared to the vehicle group.

Results

TGFβ3 (25 ng/ml) directly showed a nearly 40% increase in migrated hBMSCs via the TGFβ signaling pathway, compared to the vehicle treatment. Then, in the coculture system of hBMSCs and vascular cells, TGFβ3 further upregulated nearly 3-fold MCP1 secretion from vascular cells in a Smad3-dependent manner, to indirectly enhance nearly more than 50% of migrated hBMSCs. In vivo, TGFβ3 delivery improved MCP1 expression by nearly 7.9-fold, recruited approximately 2.0-fold CD31⁺ vascular cells and 2.0-fold Sca-1⁺ PDGFR-α⁺ MSCs, and achieved 2.5-fold bone volume fraction (BV/TV) and 2.0-fold bone mineral density, relative to TGFβ3-free delivery.

Conclusions

TGFβ3, as a MSC homing molecule, recruited MSCs to initiate bone formation in the direct-dependent and indirect-dependent mechanisms. This may shed light on the improvement of MSC homing in bone regeneration.

Long noncoding RNA expression profiles in chondrogenic and hypertrophic differentiation of mouse mesenchymal stem cells

Long noncoding RNAs (lncRNAs) are important regulators for a variety of biological processes. Chondrogenic differentiation of mesenchymal stem cells (MSCs) is a crucial stage in chondrogenesis while chondrocyte hypertrophy is related to endochondral ossification and osteoarthritis. However, the effects of lncRNAs on chondrogenic and hypertrophic differentiation of mouse MSCs are unclear. To explore the potential mechanisms of lncRNAs during chondrogenesis and chondrocyte hypertrophy, microarray was performed to investigate the expression profiles of lncRNA and mRNA in MSCs, pre-chondrocytes, and hypertrophic chondrocytes. Then, we validated microarray data by RT-PCR and screened three lncRNAs from upregulating groups during chondrogenesis and chondrocyte hypertrophy respectively. After downregulating any of the above lncRNAs, we found that the expression of chondrogenesis-related genes such as Sox9 and Col2a1 and hypertrophy-related genes including Runx2 and Col10a1 was inhibited, respectively. Furthermore, the target genes of above lncRNAs were predicted by bioinformatics approaches. Gene ontology and Kyoto encyclopedia of genes and genome biological pathway analysis were also made to speculate the functions of above lncRNAs. In conclusion, the study first revealed the expression profile of lncRNAs in chondrogenic and hypertrophic differentiations of mouse MSCs and presented a new prospect for the underlying mechanisms of chondrogenesis and endochondral ossification.

The influence of L4-S1 Dynesys® dynamic stabilization versus fusion on lumbar motion and its relationship with lumbar degeneration: a retrospective study

Background

The aim of this study is to evaluate the efficacy of Dynesys® posterior dynamic stabilization (PDS) in the treatment of L4–S1 degenerative diseases and to assess the influence of postoperative motion on lumbar degeneration.

Methods

Included in this retrospective study were patients with L4–S1 degenerative disease who underwent fusion or PDS from September 2010 to September 2014. Clinical outcomes were assessed by preoperative and postoperative visual analog scale (VAS) and Oswestry Disability Index (ODI). Preoperative and postoperative X-rays assessed range of motion (ROM) of the non-surgical and surgical levels and whole lumbar. MRI assessed degeneration of non-surgical levels.

Results

A total of 56 consecutive patients were divided into two groups: group A, PDS, and group B, fusion. Patient demographics and baseline characteristics were similar in the two groups. In both groups, there was a significant difference between preoperative and postoperative VAS and ODI scores (P < 0.05). However, there was a significant difference in a 6-month follow-up ODI between the two groups (P < 0.05). X-rays showed PDS patients partially maintained surgical level ROM and non-surgical level ROM increased less than in the fusion group. MRI showed adjacent segment degeneration (ASD) in both groups, and patients whose preoperative L3–4 Pfirrmann classification was higher than grade 2 had more ASD than lower than grade 2.

Conclusion

PDS can maintain surgical level ROM and had less influence on whole and non-surgical level ROM. Following PDS, patients recovered faster and had a better lumbar function. It may be a better choice for multi-level lumbar degenerative diseases.

[Clinical analysis of 384 cases of benign paroxysmal positional vertigo]

Objective:To study the disease characteristics in cases with benign paroxysmal positional vertigo(BPPV).Method:The characteristics and clinical features of 384 cases with BPPV were retrospectively analyzed,and all cases were treated with repositioning maneuver.The treatment outcomes were observed and analyzed during the follow-up period. Result:①Of the 384 cases,331(86.20%) cases were PC-BPPV, 47(12.24%) cases were HC-BPPV and 3(0.78%) cases were AC-BPPV, 3(0.78%) cases were combined semicircular canal BPPV. ②All cases underwent repositioning maneuver, PC-BBPV cases first efficiency was 93.66%, long-term (six months) efficiency was 96.68%; HC-BBPV cases first efficiency was 91.49%, long-term (six months) efficiency was 95.74%;AC-BPPV cases first efficiency and long-term efficiency were 66.67%;combined semicircular canal BPPV cases first efficiency and long-term efficiency were 66.67%.③Among 331 cases with PC-BBPV, cases diagnosed duct stones accounted for 96.37%,cases diagnosed crest stones accounted for 3.63%. Among 47 cases with HC-BBPV, cases diagnosed duct stones accounted for 78.72%，cases diagnosed crest stones accounted for 21.28%.④During the follow-up of six months,the recurrence rate was 12.76%(49/384). Conclusion:①In BPPV cases of Guangxi,the ratio of male and female,age of onset and the incidence of BPPV in each semicircular canal are consistent with other literatures.Geographical and ethnic factors do not affect the above results.②Repositioning maneuver is an simple and effective treatment for cases with BPPV.③There is higher recurrence rate in cases with BPPV after repositioning maneuver.

A nano-scaled and multi-layered recombinant fibronectin/cadherin chimera composite selectively concentrates osteogenesis-related cells and factors to aid bone repair

Easily accessible and effective bone grafts are in urgent need in clinic. The selective cell retention (SCR) strategy, by which osteogenesis-related cells and factors are enriched from bone marrow into bio-scaffolds, holds great promise. However, the retention efficacy is limited by the relatively low densities of osteogenesis-related cells and factors in marrow; in addition, a lack of satisfactory surface modifiers for scaffolds further exacerbates the dilemma. To address this issue, a multi-layered construct consisting of a recombinant fibronectin/cadherin chimera was established via a layer-by-layer self-assembly technique (LBL-rFN/CDH) and used to modify demineralised bone matrix (DBM) scaffolds. The modification was proven stable and effective. By the mechanisms of physical interception and more importantly, chemical recognition (fibronectin/integrins), the LBL-rFN/CDH modification significantly improved the retention efficacy and selectivity for osteogenesis-related cells, e.g., monocytes, mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs), and bioactive factors, e.g., bFGF, BMP-2 and SDF-1α. Moreover, the resulting composite (designated as DBM-LBL-rFN/CDH) not only exhibited a strong MSC-recruiting capacity after SCR, but also provided favourable microenvironments for the proliferation and osteogenic differentiation of MSCs. Eventually, bone repair was evidently improved. Collectively, DBM-LBL-rFN/CDH presented a suitable biomaterial for SCR and a promising solution for tremendous need for bone grafts.

STATEMENT OF SIGNIFICANCE

There is an urgent need for effective bone grafts. With the potential of integrating osteogenicity, osteoinductivity and osteoconductivity, selective cell retention (SCR) technology brings hope for developing ideal grafts. However, it is constrained by low efficacy and selectivity. Thus, we modified demineralized bone matrix with nano-scaled and multi-layered recombinant fibronectin/cadherin chimera (DBM-rFN/CDH-LBL), and evaluate its effects on SCR and bone repair. DBM-rFN/CDH-LBL significantly improved the efficacy and selectivity of SCR via physical interception and chemical recognition. The post-enriched DBM-rFN/CDH-LBL provided favourable microenvironments to facilitate the migration, proliferation and osteogenic differentiation of MSCs, thus accelerating bone repair. Conclusively, DBM-rFN/CDH-LBL presents a novel biomaterial with advantages including high cost-effectiveness, more convenience for storage and transport and can be rapidly constructed intraoperatively.

MiR-125b Regulates the Osteogenic Differentiation of Human Mesenchymal Stem Cells by Targeting BMPR1b

BACKGROUND/AIMS

Osteogenic differentiation of mesenchymal stem cells (MSCs) plays a crucial role in bone regeneration and bone reparation. This complex process is regulated precisely and firmly by specific factors. Recent studies have demonstrated that miR-125b regulates osteogenic differentiation, but little is known about the molecular mechanisms of this regulation. Furthermore, how miR-125b regulates the osteogenic differentiation of MSCs still needs elucidation.

METHODS

In the present study, human bone marrow-derived mesenchymal stem cells (hBMSCs) were isolated and induced to osteoblasts with miR-125b inhibition or overexpression. qRT-PCR and western blot analysis were used to detect the expression of osteogenic marker genes and proteins. Alkaline phosphatase (ALP) and Alizarin Red (ARS) staining were performed to evaluate the osteoblast phenotype. TargetScan, PicTar and miRanda database were used to predict the target gene of miR-125b. Dual luciferase reporter assay and RNA interference were performed to verify the target gene. Micro-CT imaging and histochemical staining were used to investigate the bone defect repair capacity of miR-125b in vivo.

RESULTS

We observed that miR-125b was expressed at a low level during the osteogenic differentiation of hBMSCs. Then, we found that osteogenic marker genes were negatively regulated by miR-125b during the course of osteogenic differentiation, suggesting that miR-125b down regulation plays an important role in the process of osteogenic differentiation. Bioinformatics approaches using miRNA target prediction algorithms indicated that the bone morphogenetic protein type Ib receptor (BMPR1b) is a potential target of miR-125b. The results of the dual luciferase reporter assay indicated that miR-125b binds to the 3'-UTR of the BMPR1b gene. We observed that knockdown of BMPR1b by siRNA inhibited the osteogenic differentiation of hBMSCs. Furthermore, by co-transfecting cells with an miR-125b inhibitor and si-BMPR1b, we found that the osteogenic capacity of the cells transfected with miR-125b inhibitor was blocked upon knockdown of BMPR1b. In vivo, demineralized bone matrix (DBM) was composited with hBMSCs as a scaffold to repair segmental femoral defects. By inhibiting the expression of miR-125b, hBMSCs showed a better capacity to repair bone defects.

CONCLUSIONS

Taken together, our study demonstrated that miR-125b regulated the osteogenic differentiation of hBMSCs by targeting BMPR1b and that inhibiting miR-125b expression could enhance the capacity of bone defect repair in vivo.

Treatment Experiences and Management Outcomes for Skipped Multisegmental Spinal Tuberculosis

China ranks second among the 22 countries with the highest burden of tuberculosis. The goals of this study were to evaluate the clinical outcomes of treatment of skipped multisegmental spinal tuberculosis and to investigate the selection strategy for the optimal procedure based on focal characteristics. From March 1999 to December 2013, 24 patients with skipped multisegmental spinal tuberculosis were enrolled in this study. Ten patients underwent an anterior procedure (anterior group). Four patients underwent a combined anterior and posterior procedure (combined anterior and posterior group). Ten patients underwent a posterior procedure (posterior group). All patients were evaluated according to clinical presentation and radiographic, computed tomography, and magnetic resonance imaging findings. The focal tissues of all patients underwent drug susceptibility testing. The patients underwent clinical and radiologic follow-up an average of 18.6 months post-operatively. The cohort included 13 male and 11 female patients (age range, 15-69 years). The patients showed significant improvement in deformity and neurologic deficits. All patients had graft union 6 to 12 months postoperatively. No patient had surgical complications. Postoperative recurrence occurred in 1 patient in the combined anterior and posterior group. Two patients had strains that were resistant to at least 1 anti-tuberculosis drug. One patient had multidrug-resistant strains. All 24 patients had achieved cure at final follow-up. This study showed that the 3 procedures can safely and effectively achieve nerve decompression, graft fusion, and kyphosis correction. The procedure should be chosen according to the patient's general condition, focal characteristics, and type of complication, and the surgeon's experience.

Retrospective Study of 967 Patients With Spinal Tuberculosis

China is a country with a high tuberculosis (TB) burden. Spinal TB is one reason for the resurgence of TB in China. The objective of this study was to investigate the clinical and epidemiological features of patients with spinal TB in a teaching hospital of Southwest China. The study group comprised 967 patients with spinal TB who were admitted to the authors' institution from 1999 to 2013. Demographic characteristics, prevalence of symptoms and clinical manifestations, prevalence of multidrug resistance and extensive drug resistance of spinal TB, management and outcome, and incidence of complications were recorded and analyzed. The patients included 473 women and 494 men with a mean age of 35.86±15.68 years. The most common presentation of spinal TB was back pain, followed by night sweats and fever. The thoracic spine was the most commonly involved level, followed by the lumbar spine and cervical spine. The incidence of neurological involvement in spinal TB is 33.3%. Noncontiguous spinal TB was seen in 3.41% of cases. The incidence of concomitant pulmonary TB was 14.37%. A total of 740 patients were successfully treated with surgery and anti-TB drugs. No mortality was related to spinal TB. Spinal TB increased every year from 1999 to 2013 in Southwest China. Back pain is the most common clinical symptom, and the thoracic spine is the vertebral body most often involved. The most commonly used first- and second-line anti-TB drugs are isoniazid and levofloxacin, respectively. [Orthopedics.2016; 39(5):e838-e843.].

Dihydroartemisinin attenuates lipopolysaccharide-induced osteoclastogenesis and bone loss via the mitochondria-dependent apoptosis pathway

Dihydroartemisinin (DHA) is a widely used antimalarial drug isolated from the plant Artemisia annua. Recent studies suggested that DHA has antitumor effects utilizing its reactive oxygen species (ROS) yielding mechanism. Here, we reported that DHA is inhibitory on lipopolysaccharide (LPS)-induced osteoclast (OC) differentiation, fusion and bone-resorption activity in vitro. Intracellular ROS detection revealed that DHA could remarkably increase ROS accumulation during LPS-induced osteoclastogenesis. Moreover, cell apoptosis was also increased by DHA treatment. We found that DHA-activated caspase-3 increased Bax/Bcl-2 ratio during LPS-induced osteoclastogenesis. Meanwhile, the translocation of apoptotic inducing factor (AIF) and the release of cytochrome c from the mitochondria into the cytosol were observed, indicating that ROS-mediated mitochondrial dysfunction is crucial in DHA-induced apoptosis during LPS-induced osteoclastogenesis. In vivo study showed that DHA treatment decreased OC number, prevents bone loss, rescues bone microarchitecture and restores bone strength in LPS-induced bone-loss mouse model. Together, our findings indicate that DHA is protective against LPS-induced bone loss through apoptosis induction of osteoclasts via ROS accumulation and the mitochondria-dependent apoptosis pathway. Therefore, DHA may be considered as a new therapeutic candidate for treating inflammatory bone loss.

HDAC2 regulates FoxO1 during RANKL-induced osteoclastogenesis

The bone-resorbing osteoclast (OC) is essential for bone homeostasis, yet deregulation of OCs contributes to diseases such as osteoporosis, osteopetrosis, and rheumatoid arthritis. Here we show that histone deacetylase 2 (HDAC2) is a key positive regulator during receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclastogenesis and bone resorption. Bone marrow macrophages (BMMs) showed increased HDAC2 expression during osteoclastogenesis. HDAC2 overexpression enhanced, whereas HDAC2 deletion suppressed osteoclastogenesis and bone resorption using lentivirus infection. Mechanistically, upon RANKL activation, HDAC2 activated Akt; Akt directly phosphorylates and abrogates Forkhead box protein O1 (FoxO1), which is a negative regulator during osteoclastogenesis through reducing reactive oxygen species. HDAC2 deletion in BMMs resulted in decreased Akt activation and increased FoxO1 activity during osteoclastogenesis. In conclusion, HDAC2 activates Akt thus suppresses FoxO1 transcription results in enhanced osteoclastogenesis. Our data imply the potential value of HDAC2 as a new target in regulating osteoclast differentiation and function.

Sustained release of bioactive protein from a lyophilized tissue-engineered construct promotes the osteogenic potential of mesenchymal stem cells

Tissue-engineered constructs (TECs) seeded with mesenchymal stem cells (MSCs) represent a therapy for large bone defects. However, massive cell death in TECs in the early postimplantation period prompted us to investigate the osteoinductive mechanism of TECs. Previous studies demonstrated that stem cell extracts retained equivalent levels of bioactive proteins and exhibited an osteoinductive nature similar to that of intact cells. These data led us to hypothesize that despite the massive cell death in TECs, devitalized MSC-derived proteins remain on the scaffolds and are released to improve cell function. Here, TECs were prepared using demineralized bone matrix seeded with human umbilical cord Wharton's jelly-derived MSCs (hWJMSCs), and the cells seeded in TECs were devitalized by lyophilizing the TECs. Scanning electron microscopy, BCA protein assays, quantitative cytokine array analysis and immunofluorescent staining indicated that approximately 3 mg/cm(3) of total protein and 49 types of cytokines derived from hWJMSCs were preserved in the lyophilized TECs (LTECs). The sustainable release of total protein and cytokines from LTECs lasted for more than 2 weeks. The released protein improved the osteogenic behavior of and gene expression in MSCs. Furthermore, the lyophilized hWJMSC-derived proteins had immunoregulatory properties similar to those of live MSCs in mixed lymphocyte reactions. Collectively, we present a novel perspective on the osteoinductive mechanism of TECs and introduce LTECs as new systems for delivering multiple cytokines to enhance MSC behavior.

Changing expression profiles of lncRNAs, mRNAs, circRNAs and miRNAs during osteoclastogenesis

Bone is a dynamic organ continuously undergoing shaping, repairing and remodeling. The homeostasis of bone is maintained by the balance between osteoblastic bone formation and osteoclastic bone resorption. Osteoclasts (OCs) are specialized multinucleated cells derived from hematopoietic stem cells (HSCs) or monocytes/macrophage progenitor cells. There are different stages during osteoclastogenesis, and one of the most important steps to form functional osteoclasts is realized by cell-cell fusion. In our study, microarray was performed to detect the expression profiles of lncRNA, mRNA, circRNA and miRNA at different stages during osteoclastogenesis of RAW264.7 cells. Often changed RNAs were selected and clustered among the four groups with Venn analysis. The results revealed that expressions of 518 lncRNAs, 207 mRNAs, 24 circRNAs and 37 miRNAs were often altered at each stage during OC differentiation. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) biological pathway analysis were performed to predict the functions of differentially expressed lncRNAs and co-expressed potential targeting genes. Co-expression networks of lncRNA-mRNA and circRNA-miRNA were constructed based on the correlation analysis between the differentially expressed RNAs. The present study provided a systematic perspective on the potential function of non-coding RNAs (ncRNAs) during osteoclastogenesis.

Treatment effect, postoperative complications, and their reasons in juvenile thoracic and lumbar spinal tuberculosis surgery

OBJECTIVE

Fifty-four juvenile cases under 18 years of age with thoracic and lumbar spinal tuberculosis underwent focus debridement, deformity correction, bone graft fusion, and internal fixation. The treatment effects, complications, and reasons were analyzed retrospectively.

MATERIAL AND METHOD

There were 54 juvenile cases under 18 years of age with thoracolumbar spinal tuberculosis. The average age was 9.2 years old, and the sample comprised 38 males and 16 females. The disease types included 28 thoracic cases, 17 thoracolumbar cases, and 9 lumbar cases. Nerve function was evaluated with the Frankel classification. Thirty-six cases were performed with focus debridement and deformity correction and were supported with allograft or autograft in mesh and fixed with pedicle screws from a posterior approach. Eight cases underwent a combined anterior and posterior surgical approach. Nine cases underwent osteotomy and deformity correction, and one case received focus debridement. The treatment effects, complications, and bone fusions were tracked for an average of 52 months.

RESULTS

According to the Frankel classification, paralysis was improved from 3 cases of B, 8 cases of C, 18 cases of D, and 25 cases of E preoperatively. This improvement was found in 3 cases of C, 6 cases of D, and 45 cases of E at a final follow-up postoperatively. No nerve dysfunction was aggravated. VAS was improved from 7.8 ± 1.7 preoperatively to 3.2 ± 2.1 at final follow-up postoperatively. ODI was improved from 77.5 ± 17.3 preoperatively to 28.4 ± 15.9 at final follow-up postoperatively. Kyphosis Cobb angle improved from 62.2° ± 3.7° preoperatively to 37° ± 2.4° at final follow-up postoperatively. Both of these are significant improvements, and all bone grafts were fused. Complications related to the operation occurred in 31.5% (17/54) of cases. Six cases suffered postoperative aggravated kyphosis deformity, eight cases suffered proximal kyphosis deformity, one case suffered pedicle penetration, one case suffered failure of internal devices, and one case suffered recurrence of tuberculosis.

CONCLUSION

As long as the treatment plan is fully prepared, the surgical option can achieve a satisfactory curative effect in treating juvenile spinal tuberculosis despite some complications.