The role of ApoE in fatty acid transport from neurons to astrocytes under ischemia/hypoxia conditions

BACKGROUND

The aim of this study was to investigate whether ischemia/hypoxia conditions induce fatty acid transport from neurons to astrocytes and whether this mechanism is affected by ApoE isoforms.

METHODS AND RESULTS

A neonatal rat model of hypoxic-ischemic brain damage was established. Excessive accumulation of lipid droplets and upregulation of ApoE expression occurred in the hippocampus and cerebral cortex after hypoxia-ischemia, which implied the occurrence of abnormal fatty acid metabolism. Lipid peroxidation was induced in an oxygen-glucose deprivation and reperfusion (OGDR) model of ApoE-/- primary neurons. The number of BODIPY 558/568 C12-positive particles (fatty acid markers) transferred from neurons to astrocytes was significantly increased with the addition of human recombinant ApoE compared with that in the OGDR group, which significantly increased the efficiency of fatty acid transport from neurons to astrocytes and neuronal viability. However, ApoE4 was found to be associated with lower efficiency in fatty acid transport and less protective effects in OGDR-induced neuronal cell death than both ApoE2 and ApoE3. COG133, an ApoE-mimetic peptide, partially compensated for the adverse effects of ApoE4. FABP5 and SOD1 gene and protein expression levels were upregulated in astrocytes treated with BODIPY 558/568 C12 particles.

CONCLUSIONS

In conclusion, ApoE plays an important role in mediating the transport of fatty acids from neurons to astrocytes under ischemia/hypoxia conditions, and this transport mechanism is ApoE isoform dependent. ApoE4 has a low transfer efficiency and may be a potential target for the clinical treatment of neonatal hypoxic-ischemic encephalopathy.

m6A-modified miR-143-3p inhibits epithelial mesenchymal transition in bronchial epithelial cells and extracellular matrix production in lung fibroblasts by targeting Smad3

BACKGROUND

Airway epithelial cells epithelial mesenchymal transition (EMT) and lung fibroblasts extracellular matrix (ECM) production are the key steps in airway remodeling. Our previous study demonstrated that miR-143-3p has the ability to impede airway smooth muscle cell proliferation and ECM deposition. However, the function of miR-143-3p in airway epithelial cells and lung fibroblasts remains unclear.

METHODS

Cell viability was determined using MTT method, while cell migration was evaluated through scratch assay. EMT and ECM proteins were detected by western blot, RT-qPCR, and ELISA. To determine the level of miR-143-3p m6A methylation, we employed the meRIP-qPCR assay. Additionally, the binding of miR-143-3p with Smad3 were projected by bioinformatics and validated by dual luciferase reporter assays.

RESULTS

It was discovered that the expression of miR-143-3p were lower in both asthma patients and TGF-β1-treated human bronchial epithelial 16HBE cells and human lung fibroblast HPF cells. Upregulation of miR-143-3p restrained 16HBE cell migration, and decreased EMT mesenchymal markers and increased epithelial markers. And upregulation of miR-143-3p impaired cell viability and ECM protein production in HPF cells. Mechanistically, interfering with METTL3 resulted in decreased m6A modification of miR-143-3p and led to lower levels of miR-143-3p. Moreover, miR-143-3p were verified to directly target and downregulate Smad3. Upregulation of Smad3 attenuated the effects of miR-143-3p on cell EMT and ECM production.

CONCLUSION

MiR-143-3p inhibits airway epithelial cell EMT as well as lung fibroblast ECM production by downregulating Smad3. Therefore, miR-143-3p may be a promising target to reduce airway remodeling in asthma.

Alterations in mitochondrial protein glycosylation in myocardial ischaemia reperfusion injury

The alterations in mitochondrial protein glycosylation in myocardial ischaemia reperfusion (I/R) injury are still unclear. Therefore, based on a lectin microarray and liquid chromatograph-mass spectrometer/mass spectrometer (LC‒MS/MS) technology combined with a bioinformatics analysis, we studied the changes in mitochondrial protein glycosylation during I/R injury. This study revealed significant differences in mitochondrial glycoprotein during I/R injury. Compared with the sham operation group, the model group, which underwent ischaemia for 30 min, showed a high expression of glycan structures recognized by lectins, such as WFA, PTL-I, LTL, GSL-I, SBA and SNA, and a low expression of glycan structures recognized by ConA, VVA and RCA120. The model group, which underwent ischaemia for 45 min, showed a high expression of glycan structures recognized by LTL and SNA and a low expression of glycan structures recognized by ECA. Further analysis showed that the Siaα2-6Gal/N-acetylgalactosamine (GalNAc) structures recognized by SNA were significantly increased. In total, 91 differential proteins were identified by LC‒MS/MS, and 8 hub genes were screened by Gene Ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment and protein interaction analyses. Compared with the Gene Expression Omnibus (GEO) database genes, two differential genes, Pros1 and Vtn, were obtained. Pros1 is a key regulator of the inflammatory response and vascular injury response. The Vtn gene variant is associated with the risk of myocardial infarction. This study is expected to provide a new method for the treatment of I/R injury and could provide new ideas for the postoperative prognosis of patients.

Modified interfacet technique using shaped autologous occipital bone mass for basilar invagination

PURPOSE

In economically undeveloped areas, surgery for basilar invagination (BI) is still a serious economic burden for people. This study introduces a modified interfacet technique for the treatment of BI using shaped autologous occipital bone mass to reduce BI and to save economical expenditure.

METHODS

The data of 6 patients with BI who underwent modified interfacet technique using shaped autologous occipital bone mass in our hospital from April 2020 to February 2021 were retrospectively analyzed. During the operation, osteotomy at the external occipital protuberance was performed using ultrasonic osteotome, followed by interfacet release and implantation of shaped autologous occipital bone mass to complete vertical reduction. The atlantodental interval (ADI), Chamberlain's line violation (CLV), clivo-axial angle (CXA) and cervico-medullary angle (CMA) were compared before and after surgery. Additionally, we observed implant stability during the follow-up period to assess the long-term success of the modified interfacet technique.

RESULTS

The surgical procedure was successful in all six patients, with no reported incidents of vascular injury, spinal cord injury, or dural tear. Following the operation, improvements were observed in the ADI, CLV, CXA, and CMA. Throughout the follow-up period, the implants remained stable, demonstrating no complications such as bone resorption of the autologous occipital bone mass, implant fracture, or displacement.

CONCLUSION

The utilization of shaped autologous occipital bone mass in atlantoaxial interfacet bone grafting has demonstrated effectiveness and feasibility. This technique offers simplicity, ease of preparation, and cost-effectiveness, making it a viable option for treating BI.

Interfacet Distraction for Type B-Basilar Invagination Assisted by a Novel Sliding-Traction Head Holder: 2-Dimensional Operative Video

Type B basilar invagination (BI) refers to odontoid process prolapse into skull base without dislocation, which is often associated with Chiari malformation and syringomyelia.¹ Its pathogenesis and treatment are in controversy. Posterior fossa decompression has been introduced to treat the associated Chiari malformation; however, it may not be effective for symptoms with severe ventral nerve compression.² C1-2 in situ fixation has been reported to treat minor instability in type B BI,³ yet the assessment of minor instability has not been widely accepted. We believe that the pathogenesis is chronic ventral compression of the brainstem. Transoral odontoidectomy is a classic surgical procedure to treat the pathogenesis, but it is associated with high risks of infection, velopharyngeal incompetence, and airway obstruction and often requires posterior surgery for fusion.⁴ Thus we use an interfacet distraction technique to move the odontoid process down and relieve ventral brainstem compression.⁵ Therefore interfacet structural support is necessary to maintain the distance of the interfacet. The reason for fixation is that interfacet distraction disrupts atlantoaxial stability. We designed a novel sliding-traction head holder, which can quantitatively tract and stabilize the head without support for the head or face, avoiding the risk of eyeball compression. It adapts to a variety of surgical methods and allows intraoperative changes in the patient's position. Assisted by the device, a satisfied interfacet distraction and a correction of BI were obtained. Video 1 describes how the interfacet distraction technique assisted by a sliding-traction head holder was performed in an illustrative case. The patient consented to the procedure.

Basilar invagination without atlantoaxial dislocation: treatment by correction of clivus canal angle with interfacet distraction and fixation

BACKGROUND

This study reports on the surgical technique used and clinical outcomes obtained during the treatment of basilar invagination (BI) without atlantoaxial dislocation (AAD) through the correction of the clivus canal angle (CCA) using interfacet distraction and fixation.

METHODS

Nineteen cases with BI without AAD treated by the correction of the clivus canal angle were retrospectively analyzed. Pre- and postoperative computed tomography scans and three-dimensional reconstruction views were obtained to measure the size of the CCA, pB-C2 distance, and degree of BI. Chiari malformation and syringomyelia were evaluated by magnetic resonance imaging (MRI). The clinical outcomes for all patients were measured using the Japanese Orthopedic Association (JOA) scale. The CCA was corrected by using interfacet distraction and fixation techniques. The Wilcoxon test was used to compare pre- and postoperative measurements.

RESULTS

All the patients were followed up for 24.95 ± 5.22 months (range 12-36 months); no patient suffered intraoperative nerve or vascular injury. Clinical symptoms improved in 17 patients (89.5%). The mean JOA score increased from 12.32 ± 1.89 to 14.37 ± 1.30 (Z = -3.655, P < 0.001). The mean CCA improved from 129.34 ± 8.52° preoperatively to 139.75 ± 8.86° postoperatively (Z = -3.824, P < 0.001). The mean pB-C2 decreased from 7.47 ± 2.21 to 5.68 ± 3.13 (Z = -3.060, P = 0.002). Syringomyelia was significantly reduced in 10 out of 13 patients by the first follow-up year. All patients achieved bony fusion.

CONCLUSION

Posterior interfacet distraction and fixation to correct the CCA is a feasible and effective method for treating BI without AAD.

Application of C2 subfacetal screws for the management of atlantoaxial dislocation in patients with Klippel-Feil syndrome characterized by a narrow C2 pedicle and high-riding vertebral artery

Objective

This study aims to investigate the clinical application and feasibility of C2 subfacetal screws in patients with Klippel-Feil syndrome (KFS), narrow C2 pedicles, and high-riding vertebral arteries (HRVAs).

Methods

The clinical data of seven patients with KFS, atlantoaxial dislocation, narrow C2 pedicles, and HRVAs treated with C2 subfacetal screws were analyzed in this retrospective study. The internal height, isthmus height, and pedicle width of C2 vertebra were measured using preoperative computed tomography (CT). Subfacetal screws were inserted for 7 patients (12 sides). The position and length of the screws were observed using postoperative CT. Intraoperative dura mater and vertebral artery (VA) injuries were recorded. Bone fusion was observed using follow-up CT.

Results

The internal height was 10.5 ± 3.2 mm, the isthmus height was 3.7 ± 1.8 mm, the pedicle width was 3.0 ± 1.4 mm, and the screw length was 19.7 ± 1.5 mm. All patients had HRVAs and narrow pedicles. No injury to the dura mater and vertebral artery (VA) occurred in this group of patients. Bone fusion was achieved in all patients during follow-up.

Conclusions

In patients with KFS, HRVA, and a narrow C2 pedicle, there is sufficient space below the C2 articular surface for screw insertion. When the pedicle is narrow and the C2 pedicle screw is not suitable for placement due to possible injury to the VA, subfacetal screws are a feasible alternative.

Basilar invagination: a tilt of the foramen magnum

OBJECTIVES

Congenital basilar invagination (BI) is a craniocervical deformity marked by odontoid prolapse into the skull base. The foramen magnum angle (FMA), which is formed by Chamberlain's line and McRae's line has not been fully studied. The study aimed to investigate the FMA and its relationship with other craniocervical parameters.

METHODS

Participants were divided into controls, type A BI and type B BI. Parameters included Chamberlain line violation (CLV), atlantodental interval, clivus height, clivus anteroposterior dimension, FMA, basal angle, clivo-axial angle, head and neck flexion angle, Boogard's angle, and subaxial cervical spine lordosis angle. Comparision of these parameters among the three groups and correlation analysis between FMA and other parameters was performed. The significance level was set at P<0.05.

RESULTS

A total of 111 controls, 111 type A BI patients, and 62 type B BI patients were enrolled. The FMAs in the control, type A BI, and type B BI groups were 6.21 (3.67,8.71), 22.16±6.61, and 22.39 (17.27, 31.08) °, respectively. Correlation analysis revealed correlations between the FMA and other variables. In the two BI subgroups, FMA was significantly correlated with CLV, clivus height, clivus anteroposterior dimension, basal angle, clivo-axial angle, and Boogard's angle.

CONCLUSION

The FMA in patients with BI was approximately 22° and approximately 6° in controls, indicating that the FM in BI had a greater tilt. As a pathological condition, FMA can reflect the degree of BI. Clivus hypogenesis is a reason for excessive tilt of the FM.

Biomechanical evaluation of subaxial lateral mass prothesis: a finite element analysis study

Pathologies of the lateral masses could lead to bone destruction of the cervical spine. Their treatment includes lesion resection and fixation. However, the resulting bone defect of a lateral mass is often neglected, resulting in difficulty in bone fusion. Therefore, we designed a subaxial lateral mass prosthesis to achieve lateral mass joint fusion. This study aims to evaluate the role of a new subaxial lateral mass prosthesis using finite element analysis. Five finite element models (intact, lateral mass resection, screw-rod fixation, prosthesis implantation, and prosthesis fusion groups) were compared in terms of the range of motion (ROM), prosthesis von Mises stress, and screw-rod von Mises stress during flexion, extension, lateral bending, and rotation. The ROM of the model increased significantly after lateral mass resection, and was significantly reduced after fixation with screws and rods. Screw-rod fixation combined with prosthesis implantation further reduced the ROM. After bone fusion in the prosthesis, the ROM can also be reduced slightly. The von Mises stress of the bilateral screws and rods significantly decreased after prosthesis implantation. The von Mises stress of the prosthesis further decreased during the right bending after bone fusion was achieved. Subaxial lateral mass prosthesis can help restore the stability of the cervical spine after lateral mass resection and can reduce the stress on the bilateral screws and rods. Reconstruction of a lateral mass is more consistent with the mechanical transmission of the three-column spine and contributes to interfacet fusion of the lateral mass joint.

Atlantoaxial Dislocation with Bony Fusion of C1/2 Facet Joints Treated with Posterior Joint Release, Distraction and Reduction

Introduction

Technical Note

Conclusions

Reconstruction of the cervical lateral mass using 3D-printed prostheses

Objective

This study aimed to investigate the outcome of using 3-dimensional (3D)-printed prostheses to reconstruct a cervical lateral mass to maintain cervical stability.

Methods

We retrospectively analyzed data of 7 patients who underwent cervical lateral mass reconstruction using a 3D-printed prosthesis, comprising axial and subaxial lateral mass reconstruction in 2 and 5 patients, respectively. Bilateral mass was reconstructed in 1 patient and unilateral mass in the remaining 6 patients.

Results

Using a 3D-printed lateral mass prosthesis, internal fixation was stable for all 7 patients postoperatively. No implant-related complications such as prosthesis loosening, displacement, and compression were observed at the last follow-up.

Conclusion

Reconstruction of the lateral mass structure is beneficial in restoring load transfer in the cervical spine under physiological conditions. A 3D-printed prosthesis can be considered a good option for reconstruction of the lateral mass as fusion was achieved, with no subsequent complications observed.

A 540° posterior-anterior-posterior approach for 360° fused rigid severe cervical kyphosis: patient series

BACKGROUND

Treatment of severe rigid 360° fused cervical kyphosis (CK) is challenging and often requires a combined approach for ankylosis release, establishment of sagittal balance, and fixation with fusion.

OBSERVATIONS

Four patients with iatrogenic 360° fused severe rigid CK (Cobb angle ≥40°) were enrolled for this retrospective analysis. All patients in the case series were female, with an average age of 27 years. All patients previously underwent posterior laminectomy/laminoplasty and cervical tumor resection when they were children (13–17 years). They underwent correction surgery with a 540° posterior-anterior-posterior approach. Preoperative and final follow-up radiography and computed tomography (CT) were used to evaluate kyphosis correction, internal fixation implants, and bone fusion. The preoperative and final follow-up average C2–7 Cobb angles were −32.4° ± 12.0° and 5.3° ± 7.1°, respectively. Preoperative and final follow-up CK angles averaged −47.2° ± 7.4° and −0.9° ± 16.1°, respectively. The mean correction angle was 46.3° ± 9.6°. At final follow-up, CT showed stable fixation and solid bone fusion.

LESSONS

The rare iatrogenic severe kyphosis with 360° ankylosis requires a combined approach. The 540° posterior-anterior-posterior approach can completely release the bony fusion, and the CK can be corrected using an anterior plate. This technique can achieve good results and is an effective strategy.

Subaxial lateral mass prosthesis for posterior reconstruction of cervical spine

PURPOSE

To obtain the relevant morphometry of the lateral mass of the subaxial cervical spine (C3-C7) and to design a series of lateral mass prostheses for the posterior reconstruction of the stability of cervical spine.

METHODS

The computed tomography (CT) scans of healthy volunteers were obtained. RadiAnt DICOM Viewer software (Version 2020.1, Medixant, Poland) was used to measure the parameters of lateral mass, such as height, anteroposterior dimension (APD), mediolateral dimension (MLD) and facet joint angle. According to the parameters, a series of cervical lateral mass prostheses were designed. Cadaver experiment was conducted to demonstrate its feasibility.

RESULTS

23 volunteers with an average age of 30.1 ± 7.1 years were enrolled in this study. The height of lateral mass is 14.1 mm averagely. Facet joint angle, APD and MLD of lateral mass averaged 40.1 degrees, 11.2 mm and 12.18 mm, respectively. With these key data, a lateral mass prosthesis consists of a bone grafting column and a posterior fixation plate was designed. The column has a 4.0 mm radius, 41 degrees surface angle and adjustable height of 13, 15, or 17 mm. In the cadaver experiment, the grafting column could function as a supporting structure between adjacent facets, and it would not violate exiting nerve root (NR) or vertebral artery (VA).

CONCLUSION

This study provided detailed morphology of the lateral mass of subaxial cervical spine. A series of subaxial cervical lateral mass prostheses were designed awaiting further clinical application.

Location Distribution of Fistulas and Surgical Strategies for Spinal Extradural Meningeal Cysts: A Retrospective Analysis of 30 Cases at a Single Center

Objective

This study aimed to illustrate the features of fistula location distribution, surgical strategies, and outcomes in spinal epidural meningeal cysts (SEMCs).

Methods

The authors searched and reviewed the medical records for cases of SEMCs. Imaging features, operative reports, and media were reviewed to accurately describe the surgical techniques employed. We recorded the level and laterality of the fistula according to the operative report and the media. Consistency analysis was performed on the dominant laterality of the cyst on preoperative axial magnetic resonance imaging and laterality of the fistula in the operative media or report. When cyst and fistula lateralities were the same, they were considered consistent. Finally, the Japanese Orthopedic Association (JOA) score was used to obtain patient-reported results at each follow-up.

Results

Thirty patients with SEMCs were identified. Fistula repair was performed in all patients. Two patients experienced cyst recurrence after surgery and were repaired during the second surgery. Based on imaging findings, SEMCs mostly occurred in the thoracolumbar junction. Most of the fistulas (87.88%) were at the T12 or L1 levels. In patients with multiple adjacent SEMCs, the fistula may be at one end of the cyst rather than in the middle level of the cyst. A fistula laterality of 72.72% was consistent with cyst laterality. The JOA improvement rate was 61.84%±26.63%.

Conclusion

Most fistulas were always located at the T12–L1 level as well as the middle level of the cyst, which is always consistent with cyst laterality. In patients with multiple adjacent SEMCs, the fistula may be at one end of the cyst. Cleft closure is key to healing SEMCs.

A Safe and Effective Posterior Intra-Articular Distraction Technique to Treat Congenital Atlantoaxial Dislocation Associated With Basilar Invagination: Case Series and Technical Nuances

BACKGROUND

The management of atlantoaxial dislocation (AAD) associated with basilar invagination (BI) is challenging, and traditional posterior-only approaches lack the ability to release the anterior soft tissue resulting in unsatisfactory reduction. Furthermore, vertebral artery anomalies and deformed anatomy increase surgical risks.

OBJECTIVE

To introduce a safe and efficient technique to reduce congenital AAD and BI through a single-stage posterior-only approach.

METHODS

A total of 65 patients with AAD and concomitant BI who had congenital osseous abnormalities were retrospectively analyzed. All patients had anterior soft tissue released through a posterior-only approach, followed by intra-facet cages implantation, cantilever correction, and instrumentation. Clinical results were measured using the Japanese Orthopedic Association (JOA) scale, and radiographic measurements included the atlanto-dental interval, the distance of odontoid tip above Chamberlain's line, clivus-canal angle (CCA), and syrinx length. Paired t-tests were used to compare preoperative and postoperative measurements.

RESULTS

The mean JOA score increased from 10.98 to 14.40 at 1-yr follow-up. Complete reduction of AAD and BI was achieved in 48 patients (73.8%). The mean CCA improved from 115° preoperatively to 129° postoperatively. Reduction of syrinx size was observed in 14 patients at 1 wk and in 35 patients 1 yr after surgery. All patients achieved bony fusion.

CONCLUSION

Posterior intra-articular distraction followed by cage implantation and cantilever correction can achieve complete reduction in most cases of congenitally anomalous AAD associated with BI.

Resistance of osteosarcoma cells to the proapoptotic effects of carfilzomib involves activation of mitogen activated protein kinase pathways

NEW FINDINGS

What is the central question of this study? Carfilzomib, a second-generation proteasome inhibitor approved for the treatment of multiple myeloma, shows efficacy against osteosarcoma. However, drug resistance remains a major challenge. What is the role of carfilzomib-induced changes in mitogen-activated protein kinase (MAPK) pathways in the sensitivity of osteosarcoma cells to the proapoptotic effects of the drug? What is the main finding and its importance? The dose-dependent antiapoptotic effects in osteosarcoma are associated with activation of MAPK signalling. Combinational targeting of MAPK signalling pathways can synergistically enhance carfilzomib-induced cell apoptosis, suggesting that MAPK inhibitors in combination with proteasome inhibitors can serve as a novel therapeutic tool for osteosarcoma.

ABSTRACT

Osteosarcoma is the most common primary bone malignancy. Despite efforts to improve outcomes, the overall survival rates for osteosarcoma have remained unchanged over the past three decades. In this study, we assessed the proapoptotic effects of the second-generation proteasome inhibitor carfilzomib on osteosarcoma and investigated the potential mechanisms underlying the synergistic proapoptotic action when combined with mitogen-activated protein kinase (MAPK) inhibitors. We found that carfilzomib alone significantly inhibited cell proliferation and induced apoptosis in a dose-dependent manner, characterized by the induction of cleaved caspase 3 and poly (ADP-ribose) polymerase. More importantly, focusing on the changes of antiapoptotic B-cell lymphoma 2 (Bcl-2) family members and signalling pathways, we found a striking induction of myeloid cell leukaemia 1 (Mcl-1) and the activation of MAPK pathways. Furthermore, we observed that combinational targeting of the MAPK pathways using the specific inhibitors U0126, SP600125 or SB203580 synergistically enhanced carfilzomib-induced cell apoptosis. Notably, we found that the combinational inhibition of extracellular signal-regulated kinase or c-Jun N-terminal kinase MAPK pathways significantly decreased the expression of the three antiapoptotic Bcl-2 family proteins, and in particular this reversed induction of Mcl-1 by carfilzomib. Collectively, our findings show that activation of the MAPK pathways contributes to the mechanisms of drug resistance to carfilzomib. In addition, the synergistic proapoptotic action of MAPK and proteasome inhibitors in osteosarcoma cells suggests that combinational therapy with both drug types may serve as a novel strategy for the clinical management of osteosarcoma.

ER stress arm XBP1s plays a pivotal role in proteasome inhibition-induced bone formation

BACKGROUND

Bone destruction is a hallmark of multiple myeloma (MM). It has been reported that proteasome inhibitors (PIs) can reduce bone resorption and increase bone formation in MM patients, but the underlying mechanisms remain unclear.

METHODS

Mesenchymal stem cells (MSCs) were treated with various doses of PIs, and the effects of bortezomib or carfilzomib on endoplasmic reticulum (ER) stress signaling pathways were analyzed by western blotting and real-time PCR. Alizarin red S (ARS) and alkaline phosphatase (ALP) staining were used to determine the osteogenic differentiation in vitro. Specific inhibitors targeting different ER stress signaling and a Tet-on inducible overexpressing system were used to validate the roles of key ER stress components in regulating osteogenic differentiation of MSCs. Chromatin immunoprecipitation (ChIP) assay was used to evaluate transcription factor-promoter interaction. MicroCT was applied to measure the microarchitecture of bone in model mice in vivo.

RESULTS

We found that both PERK-ATF4 and IRE1α-XBP1s ER stress branches are activated during PI-induced osteogenic differentiation. Inhibition of ATF4 or XBP1s signaling can significantly impair PI-induced osteogenic differentiation. Furthermore, we demonstrated that XBP1s can transcriptionally upregulate ATF4 expression and overexpressing XBP1s can induce the expression of ATF4 and other osteogenic differentiation-related genes and therefore drive osteoblast differentiation. MicroCT analysis further demonstrated that inhibition of XBP1s can strikingly abolish bortezomib-induced bone formation in mouse.

CONCLUSIONS

These results demonstrated that XBP1s is a master regulator of PI-induced osteoblast differentiation. Activation of IRE1α-XBP1s ER stress signaling can promote osteogenesis, thus providing a novel strategy for the treatment of myeloma bone disease.

Extracorporeal shockwave therapy combined with multiple drilling and intramedullary drug injection for treating early-stage Femur Head Necrosis: Protocol for a randomized controlled trial

BACKGROUND

Early diagnosis and treatment of the osteonecrosis of the femoral head (ONFH), a refractory disease, is imperative to prevent femoral head collapse; however, the existing solutions remain controversial. This study assessed the safety and efficacy of extracorporeal shock wave therapy (ESWT) combined with multiple drilling and intramedullary drug injection, a novel cocktail therapy, as a randomized controlled trial (RCT) model to postulate an alternative therapy for patients with early-stage ONFH.

METHODS

Femoral head necrosis patients aged 20 to 60 years with stage ARCO I-II were recruited. One hundred twenty eligible participants were randomized into four groups in a 1:1:1:1 ratio: extracorporeal shock wave therapy combined with multiple drilling and intramedullary drug injection (group EMI), extracorporeal shock wave therapy (group E), multiple drilling combined with intramedullary drug injection (group MI), and multiple drilling ("positive" control group; group M). The primary outcomes included effective rate, subchondral collapse rate of the femoral head, lesion size, and grade of bone marrow edema. Secondary outcomes included the Harris Hip Score and the visual analog scale. All outcomes were measured at the screening visit (baseline) and at the planned time intervals during treatment and follow-up, and the efficacy was statistically analyzed according to the intention-to-treat sub-populations and per-protocol sub-populations.

OBJECTIVES

To examine the clinical efficacy of ESWT combined with multiple drilling and intramedullary drug injection to provide a safe and more effective method for treating early-stage ONFH.

TRIAL REGISTRATION NUMBER

ChiCTR1900020888; Pre-results.

The biomechanical effects of foraminoplasty of different areas under lumbar percutaneous endoscopy on intervertebral discs: A 3D finite element analysis

BACKGROUND

We set out to evaluate the biomechanical influence of foraminoplasty on intervertebral discs in different areas under lumber percutaneous endoscopy through the use of a three-dimensional finite element.

METHODS

We established a normal 3D finite element mode of L3-5, using simulate lumbar percutaneous endoscopy by carrying out cylindrical excision of a bone whose diameter was 7.5 mm on the L5 superior articular process and the L4 inferior articular process, respectively. We therefore obtained 3 models. The first was the normal lumbar model, the second the L4 inferior articular process shaped model, while the third was the L5 superior articular process shaped model. We compared the biomechanics of discs of L3/4 and L4/5 in states of forward flexion, backward extension, left and right flexion as well as left and right rotation.

RESULTS

When the L4 inferior articular process shaped model was in backward extension, left rotation, and right rotation, the stress of the L4/5 disc was greater than in the normal model, especially in the state of extension. When the L5 superior articular process shaped model was in left and right rotation, the biggest stress of the L4/5 disc increased slightly. However, no matter which way the L5 superior articular process or the L4 inferior articular process of model was shaped, the stress impact of the L3/4 disc was small.

CONCLUSIONS

There is more biomechanical influence on the L4/5 disc when carrying out a foraminoplasty on L4 inferior articular process under a lumber percutaneous endoscopy. In addition, the influence of both types of surgery on the stress of L3/4 disc is small.

Three dimensional finite element analysis used to study the influence of the stress and strain of the operative and adjacent segments through different foraminnoplasty technique in the PELD: Study protocol clinical trial (SPIRIT Compliant)

INTRODUCTION

Percutaneous endoscopic lumbar disectomy (PELD) is one of the most popular minimally invasive techniques of spinal surgery in recent years. At present, there are 2 main surgical approaches in PELD: foraminal approach and interlaminar approach. What's more, foraminoplasty is a necessary step for both approaches. However, there are few biomechanical studies on the formation of different parts of the intervertebral foramen. The aim of this study is to explore the effects of different foraminoplasty methods on the biomechanics of the corresponding and adjacent segments of the lumbar through a 3-dimensional finite element model analysis.

METHODS

We established a normal 3-dimensional finite element mode of L3 to L5, simulated lumbar percutaneous endoscopy by doing cylindrical excision of bone whose diameter was 7.5 mm on the L5 superior articular process and the L4 inferior articular process, respectively, so that we obtained 3 models: the first one was normal lumbar model, the second one was the L4 inferior articular process shaped model, and the third one was the L5 superior articular process shaped model. We compared the biomechanics of the intervertebral disc of L3/4 and L4/5 when they were in the states of forward flexion, backward extension, left and right flexion, and left and right rotation on specific loading condition.

DISCUSSION

If the outcomes indicate the trial is feasible and there is evidence that one of the foraminoplasty technique may make few differences in biomechanics of corresponding lumbar intervertebral disc, we will proceed to a definitive trial to test the best way to foraminplasty, which could make biomechanical influence as little as possible.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR1900026973. Registered on September 27, 2019.

Biomechanical analysis and optimization of screw fixation technique for the cortical bone channel of lower thorax: Study protocol clinical trial (SPIRIT Compliant)

It is well known that the main segments of spinal fracture is thoracolumbar (T11-L11). Therefore, in addition to the lumbar, the lower thoracic vertebra (T9-T12) often has the clinical needs of implantation of cortical bone trajectory (CBT) screws. However, the anatomic parameters of the lower thoracic vertebrae are quite different from those of the lumbar vertebrae, which means that if CBT screws are to be implanted in the lower thoracic vertebrae, the selection of the screw entry point, the length, diameter, angle and path of the screws in each segment need to be redefined. Methods In this part, 3-dimensional finite element model was established to analyze the stress and fixation efficiency of CBT screws in thoracic vertebrae after 5000 times of fatigue loading of normal model and osteoporosis model. Discussion If the outcomes indicate the trial is feasible and there is evidence to provide some basic anatomical parameters for CBT screw implantation in the lower thoracic spine, so that the ideal insertion point, length, diameter, and angle of CBT screw in different segments of the lower thoracic spine were determined.Trial Registration Chinese Clinical Trial Registry, ChiCTR1900026915.Registered on September 26, 2019.

[Reduction of the atlantoaxial dislocation associated with basilar invagination through single-stage posterior approach: using Xuanwu occipital-cervical reduction surgical suite]

Objective: To examine the effect of posterior reduction in atlantoaxial dislocation (AAD) associated with basilar invagination(BI) using Xuanwu occipital-cervical fusion system in single stage. Methods: Thirty-seven AAD accompanied with BI cases treated at Department of Neurosurgery, Xuanwu Hospital, Capital Medical Universiy and the Second Hospital of Hebei Medical University were retrospective analyzed. There were 15 males and 22 females with age of (42.3±12.3)years (range: 18-69 yars). All the cases had congenital osseous abnormalities, such as assimilation of atlas and abnormal cervical fusion. Anterior tissue was released through posterior route followed by cage implantation into facet joint and occipital-cervical fixation with cantilever technique. The clinical results were evaluated using Japanese Orthopedic Association scale(JOA) and the main radiological measurements including anterior atlantodental interval (ADI),the distance of odontoid tip above Chamberlain line,clivus-canal angle (CCA) and the length of syrinx were collected.The preoperative and postoperative JOA score and radiological measurements were compared by paired t-test. Results: The mean JOA score of the patients increased from 10.5 to 14.4 at the one-year follow-up(t=14.3,P=0.00).Complete reduction of AAD and BI was achieved in 34 patients.The mean clivus-canal angle improved from 118.0 degrees preoperative to 143.7 degrees postoperative(t=6.2,P=0.00). Shrinkage of the syrinx was observed 1 week after surgery in 24 patients, and 6 months in 31 patients. Twenty-eight patients achieved bone fusion 6 months after surgery. All the patients achieved bone fusion 12 months after surgery. One-side vertebral artery occlusion was diagnosed in 1 case postoperatively for transient dizziness, and relieved in 2 weeks. Two patients developed moderate neck pain after surgery, and relieved in 1 month. No implant failure, spacer subsidence or infection was observed. Conclusions: The treatment of AAD associated with BI using Xuanwu occipital-cervical fusion system from posterior approach in single stage is effective and safe. Cage implantation intraarticularly and fixation with cantilever technique achieve complete reduction in most cases.

In vitro and in vivo evaluation of hypothermia on pharmacokinetics and pharmacodynamics of nimodipine in rabbits

Objective To investigate the effect of hypothermia on the pharmacokinetics and pharmacodynamics of nimodipine in rabbits using in vivo and in vitro methods. Methods Five healthy New Zealand rabbits received a single dose of nimodipine (0.5 mg/kg) intravenously under normothermic and hypothermic conditions. Doppler ultrasound was used to monitor cerebral blood flow, vascular resistance, and heart rate. In vitro evaluations of protein binding, hepatocyte uptake and intrinsic clearance of liver microsomes at different temperatures were also conducted. Results Plasma concentrations of nimodipine were significantly higher in hypothermia than in normothermia. Nimodipine improved cerebral blood flow under both conditions, but had a longer effective duration during the hypothermic period. Low temperature decreased the intrinsic clearance of liver microsomes, with no change in protein binding or hepatocyte uptake of nimodipine. Conclusion Nimodipine is eliminated at a slower rate during hypothermia than during normothermia, mainly due to the decreased activity of cytochrome P450 enzymes. This results in elevated system exposure with little enhancement in pharmacological effect.

Lectin BS-I inhibits cell migration and invasion via AKT/GSK-3β/β-catenin pathway in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is most common malignant cancer worldwide; however, the mortality rate of HCC remains high due to the invasion and metastasis of HCC. Thus, exploring novel treatments to prevent the invasion of HCC is needed for improving clinical outcome of this fatal disease. In this study, we identified lectin from Bandeiraea simplicifolia seeds (BS‐I) binds to metastasis‐associated HCC cell surface glycans by a lectin microarray and inhibits HCC cell migration and invasion through downregulating the matrix metalloproteinase 2 (MMP2), matrix metalloproteinase 9 (MMP9) and urokinase‐type plasminogen activator (uPA) production. These effects of BS‐I were mediated by inhibiting the activation of AKT/GSK‐3β/β‐catenin pathway and depended on specificity of lectin BS‐I binding to GalNAc. GSK3β inhibitors rescued BS‐I‐mediated inhibition of migration and invasion of HCC cell. Further, we identified that lectin BS‐I interacts with sGrp78, affects membrane localization of sGrp78 and attenuates the binding of sGrp78 and p85 to inhibit the activation of AKT/GSK‐3β/β‐catenin pathway. Overexpression of Grp78 or P85 rescues BS‐I‐mediated inhibition of migration and invasion of HCC cell. These findings demonstrated for the first time that BS‐I can act as a novel potential drug to prevent the invasion of HCC.

Rab23 promotes squamous cell carcinoma cell migration and invasion via integrin β1/Rac1 pathway

Rab23 was a member of Ras-related small GTPase family, which played a key role in the regulation of Shh signaling pathway. However, the function and regulatory mechanism of Rab23 in cutaneous squamous cell carcinoma was unknown. In this study, we found that the expression level of Rab23 was higher in moderately to poorly tumor differentiation tissue and non-exposed positions, and no statistically significant difference showed in Rab23 expression according to trauma/chronic disease, location on lips/ears, tumor size, gender, or age. Interestingly, we found that Rab23 RNAi suppressed cell invasion and Rab23 overexpression promoted cell invasion depended on GTP-bound form of Rab23. Inhibition of Rac1 activity or Rac1 silencing with siRNA fragment attenuated Rab23 promoted cells migration and invasion. Notably, we confirmed that Rab23 was co-localized with integrin β1 in cell membrane of Rab23 WT and Rab23 Q68L stable expression cells and Rab23 efficiently coprecipitated with integrin β1 and Tiam1 in a GTP-dependent manner. Further, integrin β1 siRNA interrupted the coprecipitation between Rab23 and Tiam1 and attenuated Rab23 promoted cells migration and invasion. Taken together, our results indicated that Rab23 promotes squamous cell carcinoma cells migration and invasion by regulating Integrin β1/Tiam1/Rac1 pathway.

MiRNA-145 Regulates the Development of Congenital Heart Disease Through Targeting FXN

Congenital heart disease (CHD) is the leading cause of death in infants in the world. The study of CHDs has come a long way since their classification and description. Although transcriptional programmes that are impaired in individuals with CHDs are being identified, the mechanisms of how these deficiencies translate to a structural defect are unknown. In this study, using high-throughput microarray analysis and molecular network analysis, FXN was identified to be the most differentially expressed key gene in CHD. By TargetScan analysis, we predicted FXN was the target gene of miRNA-145 and miRNA-182. Through real-time PCR analysis of clinical samples and experiments in cell lines, we confirmed that miRNA-145 but not miRNA-182 directly binds to the 3' UTR region of FXN and negatively regulates its expression. We further found that through targeting FXN, miRNA-145 regulates apoptosis and mitochondrial function. In general, our study confirmed the differentially expressed FXN regulates the development of CHD and the differential expression was under the control of miRNA-145. These results might provide new insight into the understanding of the CHD pathogenesis and may facilitate further therapeutic studies.

[Rab23 enhances invasion of Sa3 cutaneous squamous cell carcinoma cells via up-regulating the expression of Rac1]

OBJECTIVE

To investigate the effect of Ras-related protein 23 (Rab23) on the invasion capacity of Sa3 cutaneous squamous cell carcinaoma (cSCC) cells and determine whether Rab23 can enhance the invasion of Sa3 cells through regulation of Ras-related C3 botulinum toxin substrate 1 (Rac1).

METHODS

Sa3 cells stably expressing exogenous Rab23 or Sa3 cells deprived of endogenous Rab23 were generated using lentivirus transfection. Transwell(TM) invasion assay was used to evaluate the invasion capacity in the above-mentioned cells. The effects of Rab23 overexpression or knockdown on Rac1 expression were assessed using Western blotting. In the last experimental setting, the engineered cells were pretreated with Rac1 inhibitor Z62954982 before being subjected to the assessment of invasion capacity by Transwell(TM) assay.

RESULTS

Rab23 overexpression enhanced the invasion ability, whereas ablation of Rab23 attenuated the invasion in Sa3 cells. Rab23 could up-regulate the expression level of Rac1. Finally, using Rac1 inhibitor, we successfully suppressed the invasion capacity of Sa3 cells stably overexpressing Rab23.

CONCLUSION

Rab23 may enhance cSCC cell invasion via up-regulating Rac1 signaling.

Construction of microRNA and transcription factor regulatory network based on gene expression data in cardiomyopathy

Background

Cardiomyopathy is a progressive myocardial disorder. Here, we attempted to reveal the possible mechanism of cardiomyopathy at the transcription level with the roles of microRNAs (miRNAs) and transcription factors (TFs) taken into account.

Method

We firstly identified differentially expressed genes (DEGs) between cardiomyopathy patients and controls with data from the gene expression omnibus (GEO) database. DEGs were associated with the canonical pathways, molecular and cellular functions, physiological system development and function in the Ingenuity Knowledge Base by using the Ingenuity Pathway Analysis (IPA) software. TFs and miRNAs that DEGs significantly enriched were identified and a double-factor regulatory network was constructed.

Results

A total of 1,680 DEGs were identified. The DEGs were enriched for various pathways, with glucocorticoid receptor signaling as the most significant. A double-factor regulatory network was constructed, including seven TFs and two miRNAs. A subnetwork under the regulation of MEF2C and SRF was also constructed to illustrate their regulatory effects on cardiac functions.

Conclusion

Our results may provide new understanding of cardiomyopathy and may facilitate further therapeutic studies.

[Role of Rab23 in invasion and migration of human breast cancer Bcap-37 cells]

OBJECTIVE

To investigate the effects of Rab23 over-expression and Rab23 knock-out on the migration and invasion of breast cancer cell line Bcap-37.

METHODS

Western blotting was employed to detect the expression of Rab23 in breast cell line HBL-100 and cancer cell lines Bcap-37, MDA-MB-231, and MCF-7. Lentiviral vectors with Rab23 genes and with Rab23 RNAi were respectively transfected into breast cancer cell line Bcap-37, and the cells presenting the stable over-expression of Rab23 and the knock-out of Rab23 were respectively selected. Scratch healing assay and Transwell(R); invasion assay were used to examine the alterations of Bcap-37 cell migration and invasion potentials after Rab23 over-expression and Rab23 knock-out.

RESULTS

Western blotting indicated that Rab23 was expressed in all breast cancer cell lines and normal breast cell line. And Rab23 expression level was the highest in Bcap-37 cells, which was statistically different as compared with HBL-100 cells (P<0.01). Compared with the control group, Bcap-37 cell line with Rab23 over-expression had the dramatically enhanced migration and invasion potentials (P<0.01). On the other hand, Bcap-37 cell line with Rab23 knock-out showed the significantly attenuated migration and invasion potentials (P<0.01).

CONCLUSION

Rab23 plays a pivotal role in the migration and invasion of Bcap-37 cells.

Identification of microRNAs present in congenital heart disease associated copy number variants

PURPOSE

Congenital heart disease (CHD) is the most common congenital anomaly in newborns and about 1.35 million infants are born with CHD each year worldwide. Recently a large category of copy number variants (CNVs), were established to be a major contributor of the pathophysiology of CHD. To date most studies focused on the analysis of CNV categories or the protein coding regions without investigation on the impact of non-coding regulatory microRNAs (miRNAs).

MATERIALS AND METHODS

Here with an array comparative genome hybridisation data set and a gene expression profile data set, we investigated the contribution of miRNAs in CNVs towards the development of CHD.

RESULTS

Approximately 18% of the identified high frequency CNV loci were shown to harbor miRNAs. According the expression profile analysis, 52 target genes of 16 miRNAs showed association with CHD. Targets of hsa-miR-650 was reported to be enriched with genes of cardiac dysfunctions and heart failure categories previously. In the constructed network, all 12 miRNAs directly or indirectly interacts with CHD related genes and hsa-miR-570 showed the highest degree.

CONCLUSIONS

Our study highlights the significance of CNV-microRNAs and their target genes in the pathogenesis of CHD. This knowledge will facilitate the identification of miRNA biomarkers and the development of new therapeutics for CHD.

Shoaling and mate choice of wild-type Tanichthys albonubes in the presence of the red fluorescent transgenic conspecifics

Shoaling and sexual behaviour of wild-type male and female white cloud mountain minnow Tanichthys albonubes were measured in the presence of the red fluorescent transgenic conspecifics under laboratory conditions. Wild-type female test fish showed no significant preference, whereas wild-type male test fish preferred to be near a shoal of red transgenic fish rather than wild-type fish. When placed in a potentially reproductive context, wild-type males had a higher competitive ability over transgenic males; wild-type females spent more time with wild-type males in visually mediated experiments, but wild-type males performed more courtship displays towards transgenic females. These results suggest that the red body colouration does not appear to disturb signal communication between wild-type and transgenic T. albonubes in shoaling behaviour; transgenic males have no mating advantage over wild-type males, but the red body colouration of transgenic females may affect mate choice of wild-type males.

Androgen activates PEG10 to promote carcinogenesis in hepatic cancer cells

The molecular mechanism of striking higher prevalence of hepatocellular carcinoma (HCC) in male subjects has not yet been fully elucidated. Here, we report that androgen receptor (AR) is differentially expressed in different HCC cell lines. AR agonist dihydrotestosterone (DHT) enhances HCC cell growth and apoptotic resistance. Antagonist flutamide (FLU) blocks the effects of DHT on the HCC cell lines. Paternally expressed gene 10 (PEG10) is expressed in HCC cell lines at substantial high level. Using small interfering RNAs against AR and PEG10 in AR- and PEG10-expressing BEL-7404 hepatoma cells and HuH7 hepatoma cells (HuH7) cells, and AR-transfection technique in AR-lacking and PEG10-expressing HepG2 cells, we have confirmed that through upregulation and activation of PEG10, DHT enhances HCC cell growth and apoptotic resistance. We have further demonstrated that DHT upregulates expression of human telomerase reverse transcriptase (hTERT) in HCC cell lines in a PEG10-dependent manner. Moreover, AR directly interacts in vivo with androgen-responsive elements in the regions of promoter and exon 2 of PEG10 gene in HCC cell lines. DHT promotes the hepatoma formation in vivo nude mice through PEG10 activation. AR antagonists (FLU and valproate) inhibit the hepatoma formation. These findings suggest that PEG10 plays an essential role in hepatocarcinogenesis. The PEG10 inhibition can be a novel approach for therapy of HCC.

The extended version of the computer package CST for conversions, standardization and transformations of the spin Hamiltonian and the crystal-field Hamiltonian

The computer package CST (Conversions, Standardization and Transformations) is useful for general manipulations of the zero-field splitting (ZFS) and crystal field (CF) parameters for various systems, especially for transition ions at orthorhombic and lower symmetry sites in crystals. The ZFS parameters are extensively used in the EMR and related spectroscopic and magnetic studies (e.g. magnetic susceptibility, magnetic anisotropy, Mössbauer spectroscopy), whereas the CF parameters in optical absorption spectroscopy, inelastic neutron scattering, and infrared spectroscopy. An extended version of the CST package developed recently is presented in this paper. The standardization, including the standardization errors, for the five possible non-standard ranges of the 'rhombicity' parameter for monoclinic and triclinic symmetry in the local axis system has been worked out. The handling of the border points in the standardization module has been improved. The rotational invariants used before only for the transformations of the CF parameters have been incorporated into the standardization module for the CF and ZFS parameters expressed in any of the major tensor operator notations. The input option in the Euler angles has been added into the transformation module, and the newest physical constants in the unit conversions module have been adopted. Specific applications of the CST package for the CF and ZFS parameters will be presented elsewhere.

[Constructure of a recombinant adenovirus vector with HSV-TK and it's killer effect on tumor cells in vitro]

High-titer replication-defective recombinant adenovirus expressing HSV-TK gene was constructed. Firstly, shuttle plasmid pAdCMVTK containing HSV-TK gene and CMV promoter was constructed and then recombined with right arm of adenovirus DNA. Secondly, the positive plaques containing recombinant adenovirus were identified and selected out by PCR and Southern blotting after infection into human embryo kidney 293 cells. The titer of recombinant adenovirus AdCMVTK was determined by plaque forming assay and it was as high as 10(12) pfu/ml. Tumor cells were infected with AdCMVTK and then treated with GCV. Cytotoxic effects were assayed with MTT method. HeLa, A549 and LoVo cells infected with AdCMVTK (M. O. I. = 100) became sensitive to the prodrug GCV, with IC50 less than 4 mumol/L. Significant bystander effect was observed. Results here show that the AdCMVTK/GCV system might be potential in the gene therapy for cancer.

[Quantitative assessment of allospecific interleukin-2-secreting helper T lymphocyte in cord blood with limiting dilution assay]

OBJECTIVE

In order to investigate whether cord blood transplantation could induce severe graft versus host disease (GVHD) similar to that in bone marrow transplantation.

METHODS

The frequency of allospecific IL-2-secreting helper T lymphocyte (AIHTL) in 17 cord blood and 14 adult peripherial blood samples were detected by limiting dilution assay.

RESULTS

No statistically significant difference between the cord blood and adult peripheral blood AIHTLs was revealed.

CONCLUSION

Alloreactivity of cord blood was the same as that of adult blood. HLA typing and powerful immunosuppressive therapy should be adopted to reduce the incidence of GVHD in cord blood transplantation.