Leptin attenuates the osteogenic induction potential of BMP9 by increasing β-catenin malonylation modification via Sirt5 down-regulation

BMP9 has demonstrated significant osteogenic potential. In this study, we investigated the effect of Leptin on BMP9-induced osteogenic differentiation. Firstly, we found Leptin was decreased during BMP9-induced osteogenic differentiation and serum Leptin concentrations were increased in the ovariectomized (OVX) rats. Both in vitro and in vivo, exogenous expression of Leptin inhibited the process of osteogenic differentiation, whereas silencing Leptin enhanced. Exogenous Leptin could increase the malonylation of β-catenin. However, BMP9 could increase the level of Sirt5 and subsequently decrease the malonylation of β-catenin; the BMP9-induced osteogenic differentiation was inhibited by silencing Sirt5. These data suggested that Leptin can inhibit the BMP9-induced osteogenic differentiation, which may be mediated through reducing the activity of Wnt/β-catenin signalling via down-regulating Sirt5 to increase the malonylation level of β-catenin partly.

Unilateral Biplanar Screw-Rod Fixation Technique for the Treatment of Odontoid Fractures in Patients with Atlantoaxial Bone or Vascular Abnormalities

OBJETIVE

This study aims to introduce the unilateral biplanar screw-rod fixation (UBSF) technique (a hybrid fixation technique: 2 sets of atlantoaxial screws were placed on the same side), which serves as a salvage method for traditional posterior atlantoaxial fixation. To summarize the indications of this technique and to assess its safety, feasibility, and clinical effectiveness in the treatment of odontoid fractures.

METHODS

Patients with odontoid fractures were enrolled according to special criteria. Surgical duration and intraoperative blood loss were documented. Patients were followed up for a minimum of 12 months. X-ray and computerized tomography scans were conducted and reviewed at 1 day, and patients were asked to return for computerized tomography reviews at 3, 6, 9, and 12 months after surgery until fracture union. Recorded and compared the Neck Visual Analog Scale and Neck Disability Index presurgery and at 1 week and 12 months postsurgery.

RESULTS

Between January 2016 and December 2022, our study enrolled 7 patients who were diagnosed with odontoid fractures accompanied by atlantoaxial bone or vascular abnormalities. All 7 patients underwent successful UBSF surgery, and no neurovascular injuries were recorded during surgery. Fracture union was observed in all patients, and the Neck Visual Analog Scale and Neck Disability Index scores improved significantly at 1 week and 12 months postoperative (P < 0.01).

CONCLUSIONS

The UBSF technique has been demonstrated to be safe, feasible, and effective in treating odontoid fractures. In cases where the atlantoaxial bone or vascular structure exhibits abnormalities, it can function as a supplementary or alternative approach to the conventional posterior C1-2 fixation.

Epidemiological updates of post-traumatic related limb osteomyelitis in china: a 10 years multicentre cohort study

BACKGROUND

Post-traumatic related limb osteomyelitis (PTRLO) is a complex bone infection. Currently, there are no available microbial data on a national scale that can guide appropriate antibiotic selection, and explore the dynamic changes in dominant pathogens over time. This study aimed to conduct a comprehensive epidemiological analysis of PTRLO in China.

METHODS

The study was approved by the Institutional Research Board (IRB), and 3526 PTRLO patients were identified from 212 394 traumatic limb fracture patients at 21 hospitals between 1 January 2008 and 31 December 2017. A retrospective analysis was conducted to investigate the epidemiology of PTRLO, including changes in infection rate (IR), pathogens, infection risk factors and antibiotic resistance and sensitivity.

RESULTS

The IR of PTRLO increased gradually from 0.93 to 2.16% (Z=14.392, P <0.001). Monomicrobial infection (82.6%) was significantly higher than polymicrobial infection (17.4%) ( P <0.001). The IR of Gram-positive (GP) and Gram-negative (GN) pathogens showed a significant increase from the lowest 0.41% to the highest 1.15% (GP) or 1.62% (GN), respectively. However, the longitudinal trend of GP vs. GN's composition did not show any significance (Z=±1.1918, P >0.05). The most prevalent GP strains were Methicillin-sensitive Staphylococcus aureus (MSSA) (17.03%), Methicillin-resistant Staphylococcus aureus (MRSA) (10.46%), E. faecalis (5.19%) and S. epidermidis (4.87%). In contrast, the dominant strains GN strains were Pseudomonas Aeruginosa (10.92%), E. cloacae (10.34%), E. coli (9.47%), Acinetobacter Baumannii (7.92%) and Klebsiella Pneumoniae (3.33%). In general, the high-risk factors for polymicrobial infection include opened-fracture (odds ratio, 2.223), hypoproteinemia (odds ratio, 2.328), and multiple fractures (odds ratio, 1.465). It is important to note that the antibiotics resistance and sensitivity analysis of the pathogens may be influenced by complications or comorbidities.

CONCLUSIONS

This study provides the latest data of PTRLO in China and offers trustworthy guidelines for clinical practice. (China Clinical Trials.gov number, ChiCTR1800017597).

The anatomic study and surgical technique for canal decompression with "pedicle-plasty" strategy in lumbar burst fractures with pedicle rupture

In the treatment of lumbar burst fractures with nerve injury, fusion is often required to rebuild spinal stability, but it can lead to the loss of motor units and increase the occurrence of adjacent segment diseases. Thus, a novel approach of lumbar canal decompression with "pedicle-plasty" strategy (DDP) was needed in clincal treatment. Firstly, image measurement analysis, the images of 60 patients with lumbar spine CT examinations were selected to measure osteotomy angle (OA), distance from the intersection of osteotomy plane and skin to the posterior midline (DM),transverse length of the osteotomy plane (TLOP), and sagittal diameter of the outer edge of superior articular process (SD). Secondary, cadaver study, distance between the intermuscular space and midline (DMSM), anterior and posterior diameters of the decompression (APDD), and lateral traction distance of the lumbosacral plexus (TDLP) were measured on 10 cadaveric specimens. Finally, procedure of DDP was demonstrated on cadaver specimens. OA ranged from 27.68°+4.59° to 38.34°+5.97°, DM ranged from 43.44+6.29 to 68.33+12.06 mm, TLOP ranged from 16.84+2.19 to 19.64+2.36 mm, and SD ranged from 22.49+1.74 to 25.53+2.21 mm. DMSM ranged from 45.53+5.73 to 65.46+6.43 mm. APDD were between 10.51+3.59 and 12.12+4.54 mm, and TDLP were between 3.28+0.81 and 6.27+0.62 mm.DDP was successfully performed on cadaveric specimens. DDP, as a novel approach of decompression of burst fractures with pedicle rupture, can fully relieve the occupation and at the same time preserve the spinal motor unit because of no resection of intervertebral discs and no destruction of facet joints,and has certain developmental significance.

Heavy metal ions exchange driven protein phosphorylation cascade functions in genomic instability in spermatocytes and male infertility

DNA double-strand breaks (DSBs) are functionally linked to genomic instability in spermatocytes and to male infertility. The heavy metal cadmium (Cd) is known to induce DNA damage in spermatocytes by unknown mechanisms. Here, we showed that Cd ions impaired the canonical non-homologous end-joining (NHEJ) repair pathway, but not the homologous recombination (HR) repair pathway, through stimulation of Ser2056 and Thr2609 phosphorylation of DNA-PKcs at DSB sites. Hyper-phosphorylation of DNA-PKcs led to its premature dissociation from DNA ends and the Ku complex, preventing recruitment of processing enzymes and further ligation of DNA ends. Specifically, this cascade was initiated by the loss of PP5 phosphatase activity, which results from the dissociation of PP5 from its activating ions (Mn), that is antagonized by Cd ions through a competitive mechanism. In accordance, in a mouse model Cd-induced genomic instability and consequential male reproductive dysfunction were effectively reversed by a high dosage of Mn ions. Together, our findings corroborate a protein phosphorylation-mediated genomic instability pathway in spermatocytes that is triggered by exchange of heavy metal ions.

A phase III randomized, double-blind, placebo-controlled trial of the denosumab biosimilar QL1206 in postmenopausal Chinese women with osteoporosis and high fracture risk

The current study evaluated the efficacy and safety of a denosumab biosimilar, QL1206 (60 mg), compared to placebo in postmenopausal Chinese women with osteoporosis and high fracture risk. At 31 study centers in China, a total of 455 postmenopausal women with osteoporosis and high fracture risk were randomly assigned to receive QL1206 (60 mg subcutaneously every 6 months) or placebo. From baseline to the 12-month follow-up, the participants who received QL1206 showed significantly increased bone mineral density (BMD) values (mean difference and 95% CI) in the lumbar spine: 4.780% (3.880%, 5.681%), total hip :3.930% (3.136%, 4.725%), femoral neck 2.733% (1.877%, 3.589%) and trochanter: 4.058% (2.791%, 5.325%) compared with the participants who received the placebo. In addition, QL1206 injection significantly decreased the serum levels of C-terminal crosslinked telopeptides of type 1 collagen (CTX): -77.352% (-87.080%, -66.844%), and N-terminal procollagen of type l collagen (P1NP): -50.867% (-57.184%, -45.217%) compared with the placebo over the period from baseline to 12 months. No new or unexpected adverse events were observed. We concluded that compared with placebo, QL1206 effectively increased the BMD of the lumbar spine, total hip, femoral neck and trochanter in postmenopausal Chinese women with osteoporosis and rapidly decreased bone turnover markers. This study demonstrated that QL1206 has beneficial effects on postmenopausal Chinese women with osteoporosis and high fracture risk.

The SIRT1 activator SRT2104 promotes BMP9-induced osteogenic and angiogenic differentiation in mesenchymal stem cells

Bone defects resulting from trauma, bone tumors, infections and skeletal abnormalities are a common osteoporotic condition with respect to clinical treatment. Of the known bone morphogenetic proteins (BMPs), BMP9 has the strongest osteogenic differentiation potential, which could be beneficial in the construction of tissue-engineered bone. Silent mating type information regulator 2 homolog-1 (SIRT1) is a highly conserved nicotinamide adenine dinucleotide-dependent deacetylase that deacetylates and modulates histone or non-histone substrates. However, the role of SIRT1 in BMP9-induced osteogenic differentiation of stem cells has not been studied. Furthermore, it is unclear whether SIRT1 interacts with the BMP/Smad and BMP/MAPK pathways in stem cells. We found that SIRT1 expression decreased gradually in a time-dependent manner during BMP9-induced osteogenic differentiation of MSCs. Interactions between SIRT1 and Smad7 promoted degradation of Smad7 and increased Smad1/5/8 phosphorylation. SRT2104, an activator of SIRT, enhanced the expression of osteogenic- and angiogenic-related proteins in BMP9-induced MSCs. In addition, we found that activation of the BMP/MAPK pathway led to osteogenic and angiogenic differentiation of MSCs. Our study demonstrated that SIRT1 expression decreased during BMP9-induced differentiation. The SIRT1 activator SRT2104 promoted BMP9-induced osteogenic and angiogenic differentiation of MSCs through the BMP/Smad and BMP/MAPK signaling pathways.

Intra-articular Injection of Kartogenin-Enhanced Bone Marrow-Derived Mesenchymal Stem Cells in the Treatment of Knee Osteoarthritis in a Rat Model

BACKGROUND

In this study, we investigated the in vitro and in vivo chondrogenic capacity of kartogenin (KGN)-enhanced bone marrow-derived mesenchymal stem cells (BMSCs) for cartilage regeneration.

PURPOSE

To determine (1) whether functionalized nanographene oxide (NGO) can effectively deliver KGN into BMSCs and (2) whether KGN would enhance BMSCs during chondrogenesis in vitro and in vivo in an animal model.

STUDY DESIGN

Controlled laboratory study.

METHODS

Functionalized NGO with line chain amine-terminated polyethylene glycol (PEG) and branched polyethylenimine (BPEI) were used to synthesize biocompatible NGO-PEG-BPEI (PPG) and for loading hydrophobic KGN molecules noncovalently via π-π stacking and hydrophobic interactions (PPG-KGN). Then, PPG-KGN was used for the intracellular delivery of hydrophobic KGN by simple mixing and co-incubation with BMSCs to acquire KGN-enhanced BMSCs. The chondrogenic efficacy of KGN-enhanced BMSCs was evaluated in vitro. In vivo, osteoarthritis (OA) was induced by anterior cruciate ligament transection in rats. A total of 5 groups were established: normal (OA treated with nothing), phosphate-buffered saline (PBS; intra-articular injection of PBS), PPG-KGN (intra-articular injection of PPG-KGN), BMSCs (intra-articular injection of BMSCs), and BMSCs + PPG-KGN (intra-articular injection of PPG-KGN-preconditioned BMSCs). At 6 and 9 weeks after the surgical induction of OA, the rats received intra-articular injections of PPG-KGN, BMSCs, or KGN-enhanced BMSCs. At 14 weeks after the surgical induction of OA, radiographic and behavioral evaluations as well as histological analysis of the knee joints were performed.

RESULTS

The in vitro study showed that PPG could be rapidly uptaken in the first 4 hours after incubation, reaching saturation at 12 hours and accumulating in the lysosome and cytoplasm of BMSCs. Thus, PPG-KGN could enhance the efficiency of the intracellular delivery of KGN, which showed a remarkably high chondrogenic differentiation capacity of BMSCs. When applied to an OA model of cartilage injuries in rats, PPG-KGN-preconditioned BMSCs contributed to protection from joint space narrowing, pathological mineralization, OA development, and OA-induced pain, as well as improved tissue regeneration, as evidenced by radiographic, weightbearing, and histological findings.

CONCLUSION

Our results demonstrate that KGN-enhanced BMSCs showed markedly improved capacities for chondrogenesis and articular cartilage repair. We believe that this work demonstrates that a multifunctional nanoparticle-based drug delivery system could be beneficial for stem cell therapy. Our results present an opportunity to reverse the symptoms and pathophysiology of OA.

CLINICAL RELEVANCE

The intracellular delivery of KGN to produce BMSCs with enhanced chondrogenic potential may offer a new approach for the treatment of OA.

The role of Serpina3n in the reversal effect of ATRA on dexamethasone-inhibited osteogenic differentiation in mesenchymal stem cells

Background

Glucocorticoid-induced osteoporosis (GIOP) is the most common secondary osteoporosis. Patients with GIOP are susceptible to fractures and the subsequent delayed bone union or nonunion. Thus, effective drugs and targets need to be explored. In this regard, the present study aims to reveal the possible mechanism of the anti-GIOP effect of all-trans retinoic acid (ATRA).

Methods

Bone morphogenetic protein 9 (BMP9)-transfected mesenchymal stem cells (MSCs) were used as an in vitro osteogenic model to deduce the relationship between ATRA and dexamethasone (DEX). The osteogenic markers runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), and osteopontin were detected using real-time quantitative polymerase chain reaction, Western blot, and immunofluorescent staining assay. ALP activities and matrix mineralization were evaluated using ALP staining and Alizarin Red S staining assay, respectively. The novel genes associated with ATRA and DEX were detected using RNA sequencing (RNA-seq). The binding of the protein–DNA complex was validated using chromatin immunoprecipitation (ChIP) assay. Rat GIOP models were constructed using intraperitoneal injection of dexamethasone at a dose of 1 mg/kg, while ATRA intragastric administration was applied to prevent and treat GIOP. These effects were evaluated based on the serum detection of the osteogenic markers osteocalcin and tartrate-resistant acid phosphatase 5b, histological staining, and micro-computed tomography analysis.

Results

ATRA enhanced BMP9-induced ALP, RUNX2 expressions, ALP activities, and matrix mineralization in mouse embryonic fibroblasts as well as C3H10T1/2 and C2C12 cells, while a high concentration of DEX attenuated these markers. When DEX was combined with ATRA, the latter reversed DEX-inhibited ALP activities and osteogenic markers. In vivo analysis showed that ATRA reversed DEX-inhibited bone volume, bone trabecular number, and thickness. During the reversal process of ATRA, the expression of retinoic acid receptor beta (RARβ) was elevated. RARβ inhibitor Le135 partly blocked the reversal effect of ATRA. Meanwhile, RNA-seq demonstrated that serine protease inhibitor, clade A, member 3N (Serpina3n) was remarkably upregulated by DEX but downregulated when combined with ATRA. Overexpression of Serpina3n attenuated ATRA-promoted osteogenic differentiation, whereas knockdown of Serpina3n blocked DEX-inhibited osteogenic differentiation. Furthermore, ChIP assay revealed that RARβ can regulate the expression of Serpina3n.

Conclusion

ATRA can reverse DEX-inhibited osteogenic differentiation both in vitro and in vivo, which may be closely related to the downregulation of DEX-promoted Serpina3n. Hence, ATRA may be viewed as a novel therapeutic agent, and Serpina3n may act as a new target for GIOP.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02347-0.

Long non-coding RNA (LncRNA) HOTAIR regulates BMP9-induced osteogenic differentiation by targeting the proliferation of mesenchymal stem cells (MSCs)

Long non-coding RNAs are important regulators of biological processes, but their roles in the osteogenic differentiation of mesenchymal stem cells (MSCs) remain unclear. Here we investigated the role of murine HOX transcript antisense RNA (mHotair) in BMP9-induced osteogenic differentiation of MSCs using immortalized mouse adipose-derived cells (iMADs). Touchdown quantitative polymerase chain reaction analysis found increased mHotair expression in bones in comparison with most other tissues. Moreover, the level of mHotair in femurs peaked at the age of week-4, a period of fast skeleton development. BMP9 could induce earlier peak expression of mHotair during in vitro iMAD osteogenesis. Silencing mHotair diminished BMP9-induced ALP activity, matrix mineralization, and expression of osteogenic, chondrogenic and adipogenic markers. Cell implantation experiments further confirmed that knockdown of mHotair attenuated BMP9-induced ectopic bone formation and mineralization of iMADs, leading to more undifferentiated cells. Crystal violet staining and cell cycle analysis revealed that silencing of mHotair promoted the proliferation of iMAD cells regardless of BMP9 induction. Moreover, ectopic bone masses developed from mHotair-knockdown iMAD cells exhibited higher expression of PCNA than the control group. Taken together, our results demonstrated that murine mHotair is an important regulator of BMP9-induced MSC osteogenesis by targeting cell cycle and proliferation.

Niclosamide: drug repurposing for human chondrosarcoma treatment via the caspase-dependent mitochondrial apoptotic pathway

Poor sensitivity to chemotherapy drugs and high recurrence rates are the bottlenecks to successful chondrosarcoma treatment. Notably, niclosamide has been identified as a potential anti-cancer agent. To investigate the effects and mechanisms of niclosamide in the context of human chondrosarcoma treatment, SW1353 and CAL78 human chondrosarcoma cells were treated with various concentrations of niclosamide. The CKK-8 assay was performed to quantify cell viability. Cell proliferation was determined with crystal violet staining and colony forming assays. TUNEL and annexin V-FITC flow cytometry assays were performed to detect cell apoptosis. Wound healing and Transwell assays were conducted to evaluate migratory and invasive cell behaviors. The effect of niclosamide on the mitochondria was evaluated with the JC-1 and Seahorse Cell Mito Stress Assays. The expression of caspase-3, cleaved caspase-3, caspase-9, cleaved caspase-9, and β-tubulin levels were investigated by western blotting. Collectively, the data demonstrated that niclosamide inhibited cell growth and proliferation, attenuated migratory and invasive cell behaviors, and promoted apoptosis. Niclosamide is as a potent chondrosarcoma tumor inhibitor that activates the caspase-dependent mitochondrial apoptotic pathway and could be a novel therapeutic approach to treat chondrosarcoma.

Can the Novel LumboIliac Triangle Technique Based on Biplane Oblique Fluoroscopy Facilitate Transforaminal Percutaneous Endoscopic Lumbar Discectomy for Patients with L5-S1 Disc Herniation Combined with High Iliac Crest? Case-Control Study of 100 Patients

BACKGROUND

Percutaneous endoscopic lumbar discectomy (PELD) via the transforaminal approach is difficult at L5-S1 in patients presenting with high iliac crests (HIC). The conventional wisdom is that measurement using lumbar radiography, computed tomography (CT), or magnetic resonance imaging (MRI) is necessary.

OBJECTIVES

The objective of this study was to introduce a lumbo-iliac triangular (LI-Tri) technique based on biplane oblique fluoroscopy and verify whether it facilitated transforaminal PELD for patients with L5-S1 lumbar disc herniation (LDH) combined with HIC.

STUDY DESIGN

A retrospective analysis.

SETTING

All data were from Honghui Hospital in Xi'an.

METHODS

One hundred patients with L5-S1 LDH combined with HIC were treated with PELD. The LI-Tri technique was used in the first 50 patients (applied group). The other 50 patients were classified as the nonapplied group, in which the conventional technique was performed. Clinical outcome evaluation included Oswestry Disability Index (ODI) and Visual Analog Scale (VAS) scores. The intervals of follow-up were scheduled at 1 day and 1, 3, 6, 12, and 24 months postoperatively.

RESULTS

No significant difference was observed with respect to demographic information (P < .05, respectively). There were 8 patients in the nonapplied group with difficult punctures. Together with the remaining 50 patients, the puncture was successful with the LI-Tri technique. The mean operative duration was shorter in the applied group (55 vs 70 min, P < .01). Compared to the preoperative data, only the back pain VAS and ODI in the nonapplied group were nonsignificantly lower at one day postoperatively (P > .05, respectively). With the exception of the back pain VAS and ODI at one day postoperatively, no significant differences were observed in the 3 parameters at other time points postoperatively between 2 groups (P > .05, respectively).

LIMITATIONS

The study is limited by its retrospective, nonrandomized controlled design.

CONCLUSIONS

For patients with L5-S1 LDH combined with HIC treated by transforaminal PELD, the LI-Tri technique is simple and effective in preoperative evaluations, locating the skin entry point and guiding the puncture trajectory. Compared to the conventional technique, it shows advantages in terms of reducing intraoperative surgical duration and promoting fast postoperative recovery.

KEY WORDS

Endoscopic discectomy, iliac crest, L5-S1 disc, PELD, percutaneous, transforaminal.

The combinations of multiple factors to improve the diagnostic sensitivity and specificity after artificial joint infection

Objective

To discuss the sensitivity and specificity of the combinations of multiple factors that work on bone infection after artificial joint, and provide evidence-based medical basis for the early diagnosis of infection after artificial joint.

Methods

A retrospective review was conducted on 35 patients diagnosed with periprosthetic joint infections (PJI) or aseptic loosening (AL) who both received revision operation from January 2011 to January 2015. Analyzing and comparing their epidemiology indexes and expounded a series of auxiliary examinations corresponding positive diagnosis ratio.

Results

Thirty-five patients were divided into two groups. One is called group PJI which includes 16 patients, and the other is called group AL which contains 19 patients. There was no statistical difference between in age (p = 0.536), gender ratio (p = 0.094), and the time of catching infection or getting loose (p = 0.055). Swelling was statistical significant (p = 0.0435 < 0.05). AUC of CRP = 0.947, ESR = 0.893, IL-6 = 0.893, PCT = 0.781, WBC = 0.839, and PMN = 0.755, respectively, CRP has a high diagnostic value to PJI, ESR, IL-6, PCT, WBC, and PMN% possess a moderate diagnostic value. There were 3 cases of PJI whose pathological paraffin section showed infectious inflammatory cells (100%). three PJI patients and one AL patient whose 99mTc-MDP examination presented 100% infection or looseness rate.

Conclusion

CRP has a high diagnostic value to PJI. Histopathology HE staining, Gram staining, and 99mTc-MDP provide a highly accurate diagnosis for PJI. Therefore, the results suggest combining the unique clinical symptoms of PJI patients with relevant laboratory indexes, histopathologic characteristics, and imageological examinations that can improve diagnostic sensitivity and specificity of PJI in its early stage.

Endoscopically-Assisted Percutaneous Unilateral Atlantoaxial Screw-Rod Nonfusion Fixation Treatment for Type II Odontoid Fractures in Geriatric Patients: Case Series and Technical Note

Background: Considerable controversy exists regarding the optimal treatment for type II odontoid fractures in geriatric patients. Surgical intervention can help patients return to their prior level of function as rapidly as possible while avoiding the morbidity and mortality associated with prolonged and bedbound hospitalization. However, the optimal treatment is still a difficult choice for patients with increased risk from anesthesia. Objectives: The objective of our study was to describe an innovative method of endoscopically-assisted percutaneous unilateral C1 lateral mass screw and C2 pedicle screwrod nonfusion fixation for type II odontoid fractures in geriatric patients. Study Design: A case series design and technical notes. Setting: This study took place at Second Affiliated Hospital of Chongqing Medical University. Methods: Seven geriatric patients (> 65 years) with type II odontoid fractures and an American Society of Anesthesiologists (ASA) score of 2 or higher received endoscopicallyassisted percutaneous unilateral atlantoaxial screw-rod nonfusion fixation. After surgery, all patients were required to wear a rigid collar full-time for 12 weeks. Intraoperative data, the bone union time, American Spinal Injury Association (ASIA) scale scores, Neck Disability Index (NDI) scores, and postoperative complications were collected for assessment. Results The surgical goal was successfully achieved in all patients, 3 of whom had high ASA scores (≥3) and underwent surgery under local anesthesia. The operative time ranged from 112 to 169 minutes (mean, 131.1 minutes). No neurovascular complications were observed intraoperatively or postoperatively. All patients rapidly returned to their prior level of function and were followed up for 12 to 24 months (average: 16.9 months). Bone union was achieved in all patients. Limitations: This study is limited by being a retrospective study. Conclusions: Endoscopically-assisted percutaneous unilateral atlantoaxial screw-rod nonfusion fixation is a feasible technique for type II odontoid fractures in geriatric patients. This method offers a compromise between non-operative and operative treatment and allows geriatric patients to rapidly return to their prior level of function. Key words: Endoscopically-assisted surgery; geriatric patient; percutaneous atlantoaxial fixation; type II odontoid fracture; unilateral nonfusion fixation

Endoscopically-Assisted Percutaneous Unilateral Atlantoaxial Screw-Rod Nonfusion Fixation Treatment for Type II Odontoid Fractures in Geriatric Patients: Case Series and Technical Note

BACKGROUND

Considerable controversy exists regarding the optimal treatment for type II odontoid fractures in geriatric patients. Surgical intervention can help patients return to their prior level of function as rapidly as possible while avoiding the morbidity and mortality associated with prolonged and bedbound hospitalization. However, the optimal treatment is still a difficult choice for patients with increased risk from anesthesia.

OBJECTIVES

The objective of our study was to describe an innovative method of endoscopically-assisted percutaneous unilateral C1 lateral mass screw and C2 pedicle screw-rod nonfusion fixation for type II odontoid fractures in geriatric patients.

STUDY DESIGN

A case series design and technical notes.

SETTING

This study took place at Second Affiliated Hospital of Chongqing Medical University.

METHODS

Seven geriatric patients (> 65 years) with type II odontoid fractures and an American Society of Anesthesiologists (ASA) score of 2 or higher received endoscopically-assisted percutaneous unilateral atlantoaxial screw-rod nonfusion fixation. After surgery, all patients were required to wear a rigid collar full-time for 12 weeks. Intraoperative data, the bone union time, American Spinal Injury Association (ASIA) scale scores, Neck Disability Index (NDI) scores, and postoperative complications were collected for assessment.RESULTS The surgical goal was successfully achieved in all patients, 3 of whom had high ASA scores (>= 3) and underwent surgery under local anesthesia. The operative time ranged from 112 to 169 minutes (mean, 131.1 minutes). No neurovascular complications were observed intraoperatively or postoperatively. All patients rapidly returned to their prior level of function and were followed up for 12 to 24 months (average: 16.9 months). Bone union was achieved in all patients.

LIMITATIONS

This study is limited by being a retrospective study.

CONCLUSIONS

Endoscopically-assisted percutaneous unilateral atlantoaxial screw-rod nonfusion fixation is a feasible technique for type II odontoid fractures in geriatric patients. This method offers a compromise between non-operative and operative treatment and allows geriatric patients to rapidly return to their prior level of function.

KEY WORDS

Endoscopically-assisted surgery; geriatric patient; percutaneous atlantoaxial fixation; type II odontoid fracture; unilateral nonfusion fixation.

Modified K-Hole Percutaneous Endoscopic Surgery for Cervical Foraminal Stenosis: Partial Pediculectomy Approach

Background: Percutaneous endoscopic cervical discectomy has evolved as an efficient, minimally invasive spine surgery for radiculopathy caused by soft and/or osseous foraminal stenosis. Although interlaminar access can be used to resect lateral herniated lesions or osteophytes located in the foramina, with limited operative space, nerve retraction may be unavoidable. This procedure may injure the nerve root and cause postoperative arm pain, numbness, and muscle weakness, especially when the herniation is located in the ventral nerve root or when there is a massive osteophyte in the foramina. However, posterior partial cervical pediculectomy under endoscopy provides a new approach to effectively reduce or even avoid nerve retraction and reduce the potential risk of nerve injury. Objectives: This report presents a partial pediculectomy approach and compares the clinical outcomes of different surgical methods, including posterior percutaneous endoscopic cervical discectomy (P-PECD) and P-PECD combined with partial pediculectomy Study Design: This study used a retrospective comparative study design. Setting: This study took place at the Second Affiliated Hospital of Chongqing Medical University. Methods: From February 2015 to March 2017, 84 patients with single-level and unilateral soft and/or osseous cervical foraminal stenosis were recruited. Patients were treated with P-PECD (40 patients) and P-PECD combined with partial pediculectomy (44 patients). Postoperative clinical outcomes were assessed using the modified MacNab grading criteria and the Visual Analog Scale (VAS) at different times after surgery. The surgery duration, dosage of postoperative analgesic medication, duration of hospital stay, and postoperative complications were recorded. Results: The mean duration of the conventional P-PECD surgery was 74.48 ± 7.08 minutes, which was significantly longer (P = 0.002) than that observed for the P-PECD with partial pediculectomy (66.00 ± 9.62 minutes). The analgesic dosage in the conventional P-PECD group was significantly higher than that in the partial pediculectomy group (9.14 ± 3.07 units vs. 5.71 ± 3.41 units; P = 0.001). The hospital stay in the conventional P-PECD group was significantly longer than that in the partial pediculectomy group (3.86 ± 0.85 days vs. 3.24 ± 0.83 days; P = 0.022). The VAS scores at 1 day, 3 days, and 7 days after surgery in the conventional P-PECD group were significantly higher than those in the partial pediculectomy group (all P < 0.001). The modified MacNab grading criteria showed no significant difference at each follow-up (P = 1). The incidence of complications in the P-PECD with partial pediculectomy group (2/44, 4.55%) was significantly lower than that in the conventional P-PECD group (4/40, 10.0%), including complications of increased pain, increased numbness, and worsening of muscle weakness. Limitations: This study is limited by being a retrospective study, and by having a small sample size and a short follow-up period. Conclusions: As an alternative to the P-PECD surgical technique, P-PECD with partial pediculectomy effectively reduced the postoperative complications and may be preferable when considering the surgery duration, postoperative hospital stay, analgesic dosage, and postoperative VAS score. Key words: Cervical disc herniation, foraminal stenosis, percutaneous endoscopic cervical discectomy, PECD, P-PECD, partial pediculectomy

Modified K-Hole Percutaneous Endoscopic Surgery for Cervical Foraminal Stenosis: Partial Pediculectomy Approach

BACKGROUND

Percutaneous endoscopic cervical discectomy has evolved as an efficient, minimally invasive spine surgery for radiculopathy caused by soft and/or osseous foraminal stenosis. Although interlaminar access can be used to resect lateral herniated lesions or osteophytes located in the foramina, with limited operative space, nerve retraction may be unavoidable. This procedure may injure the nerve root and cause postoperative arm pain, numbness, and muscle weakness, especially when the herniation is located in the ventral nerve root or when there is a massive osteophyte in the foramina. However, posterior partial cervical pediculectomy under endoscopy provides a new approach to effectively reduce or even avoid nerve retraction and reduce the potential risk of nerve injury.

OBJECTIVES

This report presents a partial pediculectomy approach and compares the clinical outcomes of different surgical methods, including posterior percutaneous endoscopic cervical discectomy (P-PECD) and P-PECD combined with partial pediculectomySTUDY DESIGN: This study used a retrospective comparative study design.

SETTING

This study took place at the Second Affiliated Hospital of Chongqing Medical University.

METHODS

From February 2015 to March 2017, 84 patients with single-level and unilateral soft and/or osseous cervical foraminal stenosis were recruited. Patients were treated with P-PECD (40 patients) and P-PECD combined with partial pediculectomy (44 patients). Postoperative clinical outcomes were assessed using the modified MacNab grading criteria and the Visual Analog Scale (VAS) at different times after surgery. The surgery duration, dosage of postoperative analgesic medication, duration of hospital stay, and postoperative complications were recorded.

RESULTS

The mean duration of the conventional P-PECD surgery was 74.48 ± 7.08 minutes, which was significantly longer (P = 0.002) than that observed for the P-PECD with partial pediculectomy (66.00 ± 9.62 minutes). The analgesic dosage in the conventional P-PECD group was significantly higher than that in the partial pediculectomy group (9.14 ± 3.07 units vs. 5.71 ± 3.41 units; P = 0.001). The hospital stay in the conventional P-PECD group was significantly longer than that in the partial pediculectomy group (3.86 ± 0.85 days vs. 3.24 ± 0.83 days; P = 0.022). The VAS scores at 1 day, 3 days, and 7 days after surgery in the conventional P-PECD group were significantly higher than those in the partial pediculectomy group (all P < 0.001). The modified MacNab grading criteria showed no significant difference at each follow-up (P = 1). The incidence of complications in the P-PECD with partial pediculectomy group (2/44, 4.55%) was significantly lower than that in the conventional P-PECD group (4/40, 10.0%), including complications of increased pain, increased numbness, and worsening of muscle weakness.

LIMITATIONS

This study is limited by being a retrospective study, and by having a small sample size and a short follow-up period.

CONCLUSIONS

As an alternative to the P-PECD surgical technique, P-PECD with partial pediculectomy effectively reduced the postoperative complications and may be preferable when considering the surgery duration, postoperative hospital stay, analgesic dosage, and postoperative VAS score.

KEY WORDS

Cervical disc herniation, foraminal stenosis, percutaneous endoscopic cervical discectomy, PECD, P-PECD, partial pediculectomy.

IGF-1 reverses the osteogenic inhibitory effect of dexamethasone on BMP9-induced osteogenic differentiation in mouse embryonic fibroblasts via PI3K/AKT/COX-2 pathway

Glucocorticoid-Induced Osteoporosis (GIOP) is a prevalent clinical complication caused by large dose administration of glucocorticoids, such as Dexamethasone (Dex) and Prednisone. GIOP may lead to fractures and even Osteonecrosis of the Femoral Head (ONFH). It has been reported that glucocorticoids inhibit osteogenesis via the suppression of osteogenic differentiation in Mesenchymal Stem Cells (MSCs), but the precise mechanism underlying this suppression awaits further investigation. Meanwhile, novel and efficacious therapies are recommended to cope with GIOP. In this study, we demonstrated that Dex had the inhibitory effect on Bone Morphogenetic Protein 9 (BMP9)-induced ALP activities and matrix mineralization in Mouse Embryonic Fibroblasts (MEFs). In addition, the study confirmed that Dex decreased the expression of osteogenic markers such as Runx2 and OPN. However, the inhibitory effect of Dex on these osteogenic markers can be reversed when combined with insulin-like growth factor 1 (IGF-1). Regarding the inhibitory mechanism, we found that the level of AKT and p-AKT can be decreased by Dex and that Ly294002, the PI3K inhibitor, can block the reversal effect of IGF-1. Moreover, the knockdown or inhibition of COX-2 produced similar results to those of Ly294002. Our findings indicated that IGF-1 may reverse the osteogenic inhibitory effect of Dex via PI3K/AKT pathway, which may be associated with the up-regulation of COX-2. This study may provide new clinical management strategy for GIOP cases.

Treatment of Single-Level Thoracic Tuberculosis by Percutaneous Endoscopic Débridement and Allograft via the Transforaminal Approach Combined with Percutaneous Pedicle Screw Fixation: A Multicenter Study with a Median Follow-Up of 36 Months

OBJECTIVE

To examine effects of percutaneous endoscopic débridement and allograft via the transforaminal approach combined with percutaneous pedicle screw fixation as treatment for single-level thoracic tuberculosis.

METHODS

This multicenter retrospective analysis included 75 patients with single-level thoracic tuberculosis who underwent percutaneous endoscopic débridement and allograft via the transforaminal approach combined with percutaneous pedicle screw fixation and were followed for >36 months between January 2012 and December 2014.

RESULTS

Follow-up was 36-48 months (average 41.1 ± 2.2 months). Intraoperative blood loss was low (average 30.5 ± 7.9 mL), and bed rest time was short (average 1.5 ± 0.3 days). No recurrence was observed in all 75 patients. Except for 3 patients, almost all patients (96%) achieved grade I or II fusion in interbody bone grafting. Segmental Cobb angle was 13.5° ± 4.1° before surgery, 10.5° ± 3.7° immediately after surgery, and 11.7° ± 3.9° at 36 months of follow-up. All patients achieved complete recovery of neurologic function (American Spinal Injury Association grade E), including 15 patients with spinal cord injury (American Spinal Injury Association grade D) before surgery. The visual analog scale and 36-Item Short-Form Health Survey scores significantly improved at 1, 3, 12, and 36 months of follow-up. No complications related to internal fixation occurred within the follow-up period; complication rate was 9.0%.

CONCLUSIONS

Median follow-up clinical experience with percutaneous endoscopic débridement and allograft via the transforaminal approach combined with percutaneous pedicle screw fixation indicates that the technique is safe, effective, feasible, and minimally invasive.

Usage of Bone Wax to Facilitate Percutaneous Endoscopic Cervical Discectomy Via Anterior Transcorporeal Approach for Cervical Intervertebral Disc Herniation

BACKGROUND

Currently, anterior transdiscal access and posterior interlaminar approach are the main approaches for percutaneous endoscopic cervical discectomy (PECD). To overcome access shortcomings, we previously described a novel anterior endoscopic transcorporeal approach on a migrated cervical disc. We innovatively introduced bone wax into endoscopic surgery to aid hemostasis and facilitate the process of drilling an intracorporeal tunnel.

METHODS

Five patients with cervical intervertebral disc herniation (CIDH) were treated by PECD via the anterior transcorporeal approach. During the operation, we marked the punctured tunnel with bone wax containing indigo carmine as a guide and smeared bone wax on the endoscopic burr to aid hemostasis.

RESULTS

A satisfactory clinical outcome was observed in all 5 patients postoperatively; pain and neurologic condition were dramatically improved. Surgery-related complications, such as esophageal injury, vascular rupture, hematoma, intervertebral disc infection, or postoperative headache, were not encountered. A computed tomography scan was used to observe the process of bone healing. At 3-month postoperative follow-up, the bone defect within the drilling tunnel had partially shrank and was completely healed at 6 months postoperatively.

CONCLUSIONS

The anterior endoscopic transcorporeal approach for PECD is a novel, valuable alternative for the treatment of CIDH. Bone wax could indeed facilitate the operation by guiding the drilling process and instantly controlling the bleeding without obvious interference with bone healing. Long-term follow-up is warranted in further clinical studies.

Percutaneous Endoscopic Retrieval of Intraspinal Cement Leakage: Technical Note

OBJECTIVE

We sought to preliminarily explore the efficacy and safety of percutaneous endoscopic spinal surgery for epidural cement leakage. We report a case series of patients who underwent percutaneous retrieval of leaked epidural cement and achieved spinal decompression under endoscopy.

METHODS

Five patients with neurologic impairment due to epidural cement leakage after percutaneous vertebroplasty were treated with percutaneous endoscopic spinal decompression. Computed tomography reconstruction and 3-dimensional imaging were used to evaluate the extruded material. During follow-up at 3, 6, and 12 months postoperatively, all patients were advised to undergo plain radiograph and computed tomography examinations.

RESULTS

The leaked epidural cement was successfully removed in all patients under percutaneous endoscopy through a unilateral or bilateral approach. At the 12-month follow-up, the visual analog scale score of all patients improved. In addition, the neurologic function of each patient improved to at least 1 grade level, as evaluated using the American Spinal Injury Association. According to the modified MacNab criteria, 2 patients had excellent recovery, whereas the other 3 patients had good recovery.

CONCLUSIONS

We described a novel and minimally invasive procedure to ameliorate intractable epidural cement extrusion. As an alternative to conventional laminectomy, percutaneous endoscopic retrieval achieved the targeted decompression without damaging the posterior lamina. Moreover, the whole operation was performed under regional anesthesia accompanied with dexmedetomidine sedation, allowed real-time neural function evaluation, and had lower risks of anesthesia-related complications, compared with general anesthesia.

Knockdown of Bone Morphogenetic Proteins Type 1a Receptor (BMPR1a) in Breast Cancer Cells Protects Bone from Breast Cancer-Induced Osteolysis by Suppressing RANKL Expression

BACKGROUND/AIMS

Bone morphogenetic proteins (BMPs) and BMP receptors widely participate in osteolytic metastasis of breast cancer, while their role in tumor-stromal interaction is largely unknown. In this study, we investigated whether BMP receptor type 1a (BMPR1a) can alter the interaction between metastatic cancer cells and osteoclast precursors.

METHODS

Adenovirus-mediated RNA interference was used to interrupt target genes of human breast cancer cell lines and nude mice were injected intratibially with the cancer cells. Tumor-bearing mice were examined by bioluminescence imaging and microCT. Sections of metastatic legs were measured by a series of staining methods. Murine bone marrow mononuclear cells or RAW264.7 cells were cultured with conditioned media of breast cancer cells. RT-PCR, Western blotting and ELISA were used to test mRNA and protein expressions of target molecules.

RESULTS

Expression of BMPR1a of MDA-MB-231-luc cells at tumor-bone interface was apparently stronger than that of cancer cells distant from the interface. Mice injected with BMPR1a-knockdown MDA-MB-231-luc cells showed reduced tumor growth and bone destruction compared with control groups. Knockdown (KD) of BMPR1a of MDA-MB-231-luc cells or MCF-7 cells decreased the level of receptor activator for NF-κB ligand (RANKL). Level of RANKL in MDA-MB-231-luc cells or MCF-7 cells was reduced by p38 inhibitor. Compared with control group, knockdown of p38 of breast cancer cells decreased cancer-induced osteoclastogenesis.

CONCLUSION

Knockdown of BMPR1a of breast cancer cells suppresses their production of RANKL via p38 pathway and inhibits cancer-induced osteoclastogenesis, which indicates that BMPR1a might be a possible target in breast cancer-induced osteolytic metastasis.

BMP9/COX-2 axial mediates high phosphate-induced calcification in vascular smooth muscle cells via Wnt/β-catenin pathway

Vascular calcification is a notable risk factor for cardiovascular system. High phosphate can induce calcification in vascular smooth muscle cells (VSMCs), but the detail mechanism underlying this process remains unclear. In the present study, we determined the relationship between high phosphate and bone morphogenetic protein 9 (BMP9) in VSMCs, the effect of BMP9 on calcification in VSMCs and the effect of COX-2 on BMP9 induced calcification in VSMCs, as well as the possible mechanism underlying this biological process. We found that high phosphate obviously up-regulates the expression of BMP9 in VSMCs. Over-expression of BMP9 decreases the level of alpha-smooth muscle cell actin (α-SMA) apparently, but increases the level of Runx-2, Dlx-5, and ALP in VSMCs. Meanwhile, BMP9 increases the level of OPN and OCN, promotes mineralization in VSMCs and induces calcification in thoracic aorta. High phosphate and over-expression of BMP9 increases the level of COX-2. Over-expression of COX-2 enhances the inhibitory effect of BMP9 on α-SAM and increases the level of OPN and OCN induced by BMP9. However, inhibition of COX-2 decreases the BMP9-induced calcification in VSMCs and thoracic aorta. For mechanism, we found that high phosphate or BMP9 increases the level of β-catenin and p-GSK3β in VSMCs, but no substantial effect on GSK3β. However, COX-2 inhibitor decreases the expression of β-catenin induced by BMP9. Our findings indicated that BMP9 is involved in the phosphate-induced calcification in VSMCs and COX-2 partly mediates the BMP9-induced calcification in VSMCs through activating Wnt/β-catenin pathway.

lncRNA H19 mediates BMP9-induced osteogenic differentiation of mesenchymal stem cells (MSCs) through Notch signaling

Mesenchymal stem cells (MSCs) are multipotent progenitor cells that can undergo self-renewal and differentiate into multiple lineages. Osteogenic differentiation from MSCs is a well-orchestrated process and regulated by multiple signaling pathways. We previously demonstrated that BMP9 is one of the most potent osteogenic factors. However, molecular mechanism through which BMP9 governs osteoblastic differentiation remains to be fully understood. Increasing evidence indicates noncoding RNAs (ncRNAs) may play important regulatory roles in many physiological and/or pathologic processes. In this study, we investigate the role of lncRNA H19 in BMP9-regulated osteogenic differentiation of MSCs. We demonstrated that H19 was sharply upregulated at the early stage of BMP9 stimulation of MSCs, followed by a rapid decease and gradual return to basal level. This process was correlated with BMP9-induced expression of osteogenic markers. Interestingly, either constitutive H19 expression or silencing H19 expression in MSCs significantly impaired BMP9-induced osteogenic differentiation in vitro and in vivo, which was effectively rescued by the activation of Notch signaling. Either constitutive H19 expression or silencing H19 expression led to the increased expression of a group of miRNAs that are predicted to target Notch ligands and receptors. Thus, these results indicate that lncRNA H19 functions as an important mediator of BMP9 signaling by modulating Notch signaling-targeting miRNAs. Our findings suggest that the well-coordinated biphasic expression of lncRNA H19 may be essential in BMP9-induced osteogenic differentiation of MSCs, and that dysregulated H19 expression may impair normal osteogenesis, leading to pathogenic processes, such as bone tumor development.

Gelatin-Derived Graphene-Silicate Hybrid Materials Are Biocompatible and Synergistically Promote BMP9-Induced Osteogenic Differentiation of Mesenchymal Stem Cells

Graphene-based materials are used in many fields but have found only limited applications in biomedicine, including bone tissue engineering. Here, we demonstrate that novel hybrid materials consisting of gelatin-derived graphene and silicate nanosheets of Laponite (GL) are biocompatible and promote osteogenic differentiation of mesenchymal stem cells (MSCs). Homogeneous cell attachment, long-term proliferation, and osteogenic differentiation of MSCs on a GL-scaffold were confirmed using optical microscopy and scanning electron microscopy. GL-powders made by pulverizing the GL-scaffold were shown to promote bone morphogenetic protein (BMP9)-induced osteogenic differentiation. GL-powders increased the alkaline phosphatase (ALP) activity in immortalized mouse embryonic fibroblasts but decreased the ALP activity in more-differentiated immortalized mouse adipose-derived cells. Note, however, that GL-powders promoted BMP9-induced calcium mineral deposits in both MSC lines, as assessed using qualitative and quantitative alizarin red assays. Furthermore, the expression of chondro-osteogenic regulator markers such as Runx2, Sox9, osteopontin, and osteocalcin was upregulated by the GL-powder, independent of BMP9 stimulation; although the powder synergistically upregulated the BMP9-induced Osterix expression, the adipogenic marker PPARγ was unaffected. Furthermore, in vivo stem cell implantation experiments demonstrated that GL-powder could significantly enhance the BMP9-induced ectopic bone formation from MSCs. Collectively, our results strongly suggest that the GL hybrid materials promote BMP9-induced osteogenic differentiation of MSCs and hold promise for the development of bone tissue engineering platforms.

Bone morphogenetic protein 9 stimulates callus formation in osteoporotic rats during fracture healing

Fracture healing involves the coordinated actions of multiple cytokines. Bone morphogenetic protein 9 (BMP9) is an important factor in bone formation. The present study aimed to investigate the osteogenic potential of bone marrow stem cells (BMSCs) in response to adenoviral (Ad)BMP9, and the early fracture repair properties of AdBMP9 in surgically-created fractures in osteoporotic rats. Alkaline phosphatase (ALP) activity was assayed and matrix mineralization was examined by Alizarin Red S staining. mRNA and protein expression levels of BMP9, runt-related transcription factor 2 (RUNX2) and type 1 collagen (COL-1) were detected in vitro and in vivo. Femoral bone mineral density was assessed for osteoporosis in ovariectomized rats. An open femora fracture was subsequently created, and gelatin sponges containing AdBMP9 were implanted. The femora were harvested for radiographical, micro-computed tomography, biomechanical and histological analysis 4 weeks later. BMP9 successfully increased ALP activity and induced mineralized nodule formation in BMSCs. BMP9 in gelatin sponges demonstrated marked effects on microstructural parameters and the biomechanical strength of bone callus. In addition, it upregulated the expression levels of RUNX2 and COL-1. AdBMP9 in gelatin sponges significantly mediated callus formation, and increased bone mass and strength in osteoporotic rats with femora fractures. The results of the present study suggested that BMP9 enhanced callus formation and maintained early mechanical stability during fracture healing in osteoporotic rats, implicating it as a potential novel therapeutic target for fracture healing.

Percutaneous Endoscopic Lumbar Discectomy for Highly Migrated Lumbar Disc Herniation

Background: Percutaneous endoscopic lumbar discectomy (PELD) has been growing in popularity for the treatment of lumbar disc herniation (LDH) due to its irreplaceable advantages over conventional open surgery. Compared with common lumbar disc herniations, discectomy of highly migrated LDH by PELD is known to be very difficult. Highly migrated lumbar disc herniation has long been a challenge for its specific characteristics. Three approaches for PELD have been applied to access a highly migrated LDH, including an interlaminar approach (IL), transforaminal approach (TF), and contralateral transforaminal approach (CTF). However, none of the existing research has systematically described the selection of the most appropriate procedure from the 3 approaches or the individualization of an operative procedure in different cases. Objectives: The purpose of this study was to present a detailed surgical approach selection and individualization of procedure in the treatment of highly migrated LDH with PELD. We also mean to compare the outcomes of patients with highly migrated LDH treated with PELD by the 3 approaches. Study Design: Single-center retrospective observational study. Setting: An interventional pain management practice, a medical center, major metropolitan city, China. Methods: In our retrospective analysis between March 2011 and March 2013, 73 patients with single level highly migrated LDH received PELD. Clinical outcomes were assessed with the visual analogue scale (VAS) score, the modified MacNab criteria, and the Oswestry disability index (ODI). Relevant data such as operation duration and fluoroscopy frequency of the 3 operative approaches were recorded. Results: The mean operating time of IL was 56 minutes, compared with 64 minutes for TF and 112 minutes for CTF. The mean intraoperative fluoroscopy times were 5.5 for IL, 9.7 for TF, and 14.6 for CTF. In each group, the mean VAS and ODI after surgery and 3 months after surgery improved dramatically compared with preoperative counterparts. However, the difference between postoperative results and the results 3 months after surgery was not significant (P > 0.05). The overall excellent rate was 90.4% according to the modified MacNab criteria; there was no significant statistical difference between the 3 operative routes. Operative complications occurred in 3 patients (2 after IL and one after CTF, 3 of 73, 4.1%). Limitations: This study is limited by its sample size. Conclusion: In our research, PELD with all 3 approaches was similarly effective to highly migrated disc herniation. The CTF approach required the longest operation duration and the most intraoperative times. On the contrary, the least operation time and radiographfrequency was required with the IL approach. In addition, we came to a conclusion of surgery approach selection when it comes to varied HM-LDH. Key words: Highly migrated, lumbar disc herniation, percutaneous endoscopic lumbar discectomy, minimally invasive treatment Pain Physician 2017;

Percutaneous Endoscopic Lumbar Discectomy for Highly Migrated Lumbar Disc Herniation

BACKGROUND

Percutaneous endoscopic lumbar discectomy (PELD) has been growing in popularity for the treatment of lumbar disc herniation (LDH) due to its irreplaceable advantages over conventional open surgery. Compared with common lumbar disc herniations, discectomy of highly migrated LDH by PELD is known to be very difficult. Highly migrated lumbar disc herniation has long been a challenge for its specific characteristics. Three approaches for PELD have been applied to access a highly migrated LDH, including an interlaminar approach (IL), transforaminal approach (TF), and contralateral transforaminal approach (CTF). However, none of the existing research has systematically described the selection of the most appropriate procedure from the 3 approaches or the individualization of an operative procedure in different cases.

OBJECTIVES

The purpose of this study was to present a detailed surgical approach selection and individualization of procedure in the treatment of highly migrated LDH with PELD. We also mean to compare the outcomes of patients with highly migrated LDH treated with PELD by the 3 approaches.

STUDY DESIGN

Single-center retrospective observational study.

SETTING

An interventional pain management practice, a medical center, major metropolitan city, China.

METHODS

In our retrospective analysis between March 2011 and March 2013, 73 patients with single level highly migrated LDH received PELD. Clinical outcomes were assessed with the visual analogue scale (VAS) score, the modified MacNab criteria, and the Oswestry disability index (ODI). Relevant data such as operation duration and fluoroscopy frequency of the 3 operative approaches were recorded.

RESULTS

The mean operating time of IL was 56 minutes, compared with 64 minutes for TF and 112 minutes for CTF. The mean intraoperative fluoroscopy times were 5.5 for IL, 9.7 for TF, and 14.6 for CTF. In each group, the mean VAS and ODI after surgery and 3 months after surgery improved dramatically compared with preoperative counterparts. However, the difference between postoperative results and the results 3 months after surgery was not significant (P > 0.05). The overall excellent rate was 90.4% according to the modified MacNab criteria; there was no significant statistical difference between the 3 operative routes. Operative complications occurred in 3 patients (2 after IL and one after CTF, 3 of 73, 4.1%).

LIMITATIONS

This study is limited by its sample size.

CONCLUSION

In our research, PELD with all 3 approaches was similarly effective to highly migrated disc herniation. The CTF approach required the longest operation duration and the most intraoperative times. On the contrary, the least operation time and radiographfrequency was required with the IL approach. In addition, we came to a conclusion of surgery approach selection when it comes to varied HM-LDH. Key words: Highly migrated, lumbar disc herniation, percutaneous endoscopic lumbar discectomy, minimally invasive treatment.

IGF1 potentiates BMP9-induced osteogenic differentiation in mesenchymal stem cells through the enhancement of BMP/Smad signaling

Engineered bone tissue is thought to be the ideal alternative for bone grafts in the treatment of related bone diseases. BMP9 has been demonstrated as one of the most osteogenic factors, and enhancement of BMP9-induced osteogenesis will greatly accelerate the development of bone tissue engineering. Here, we investigated the effect of insulin-like growth factor 1 (IGF1) on BMP9-induced osteogenic differentiation, and unveiled a possible molecular mechanism underling this process. We found that IGF1 and BMP9 are both detectable in mesenchymal stem cells (MSCs). Exogenous expression of IGF1 potentiates BMP9-induced alkaline phosphatase (ALP), matrix mineralization, and ectopic bone formation. Similarly, IGF1 enhances BMP9-induced endochondral ossification. Mechanistically, we found that IGF1 increases BMP9-induced activation of BMP/Smad signaling in MSCs. Our findings demonstrate that IGF1 can enhance BMP9-induced osteogenic differentiation in MSCs, and that this effect may be mediated by the enhancement of the BMP/Smad signaling transduction triggered by BMP9. [BMB Reports 2016; 49(2): 122-127]

Ursolic acid inhibits proliferation and induces apoptosis by inactivating Wnt/β-catenin signaling in human osteosarcoma cells

Although multiple chemotherapeutic agents have been used for osteosarcoma (OS) treatment, their mechanisms need further study. Ursolic acid (UA), a pentacyclic triterpenoid, can reduce cell proliferation and induce apoptosis in various cancer cells, such as OS. However, the exact mechanism underlying this function remains unclear. In this study, we investigated the anti‑proliferative effect of UA in human OS 143B cells and dissected the possible molecular mechanism underlying this effect. We demonstrated that UA can reduce cell proliferation, induce apoptosis and arrest cell cycle in 143B cells, as well as inhibit OS tumor growth in a mouse xenograft model. Using a luciferase reporter assay, we found that the Wnt/β‑catenin signaling is inhibited by UA in 143B cells. Correspondingly, the expression level and nuclear translocation of β‑catenin are both decreased by UA. Exogenous expression of β‑catenin attenuates the anticancer effect of UA in 143B cells, while knockdown of β‑catenin enhances this effect. UA increases the expression level of p53 in a concentration‑dependent manner, and inhibition of p53 reduces the anticancer effect of UA in 143B cells. Moreover, inhibition of p53 partly reverses the UA‑induced downregulation of β‑catenin, as do the targets of Wnt/β‑catenin signaling, such as c‑Myc and cyclin D1. Our findings indicated that UA can inhibit the proliferation of 143B OS cells through inactivation of Wnt/β-catenin signaling, which may be mediated partly by upregulating the expression of p53.

All-trans retinoic acid shifts rosiglitazone-induced adipogenic differentiation to osteogenic differentiation in mouse embryonic fibroblasts

Rosiglitazone (RSG) is a potent drug used in the treatment of insulin resistance; however, it is associated with marked skeletal toxicity. RSG-induced osteoporosis may contribute to the promotion of adipogenic differentiation at the expense of osteogenic differentiation in bone marrow stromal cells. The aim of this study was to investigate whether RSG-induced bone toxicity can be reversed by combined treatment with all-trans retinoic acid (ATRA). We examined different osteogenic markers in mouse embryonic fibroblasts (MEFs) following treatment with RSG, ATRA, or RSG and ATRA in combination. We examined the effects of RSG and/or ATRA on ectopic bone formation, and dissected the possible molecular mechanisms underlying this process. We found that ATRA or RSG both induced alkaline phosphatase (ALP) activity in the MEFs, and that the ATRA-induced ALP activity was enhanced by RSG and vice versa. However, only the combination of RSG and ATRA increased the expression of osteopontin and osteocalcin, promoted matrix mineralization, and induced ectopic ossification in MEFs. Mechanistically, we found that the osteogenic differentiation induced by the combination of RSG and ATRA may be mediated partly by suppressing RSG-induced adipogenic differentiation and activating bone morphogenetic protein (BMP)/Smad signaling. On the whole, our findings demonstrate that RSG in combination with ATRA promotes the commitment of MEFs to the osteoblast lineage. Thus, the combination of these two agents may prove to be a promising and novel therapeutic regimen for insulin resistance without skeletal toxicity. It may also be a better strategy with which to prevent RSG-induced osteoporosis.

Adenovirus-mediated siRNA targeting CXCR2 attenuates titanium particle-induced osteolysis by suppressing osteoclast formation

Background

Wear particle-induced peri-implant loosening is the most common complication affecting long-term outcomes in patients who undergo total joint arthroplasty. Wear particles and by-products from joint replacements may cause chronic local inflammation and foreign body reactions, which can in turn lead to osteolysis. Thus, inhibiting the formation and activity of osteoclasts may improve the functionality and long-term success of total joint arthroplasty. The aim of this study was to interfere with CXC chemokine receptor type 2 (CXCR2) to explore its role in wear particle-induced osteolysis.

Material/Methods

Morphological and biochemical assays were used to assess osteoclastogenesis in vivo and in vitro. CXCR2 was upregulated in osteoclast formation.

Results

Local injection with adenovirus-mediated siRNA targeting CXCR2 inhibited titanium-induced osteolysis in a mouse calvarial model in vivo. Furthermore, siCXCR2 suppressed osteoclast formation both directly by acting on osteoclasts themselves and indirectly by altering RANKL and OPG expression in osteoblasts in vitro.

Conclusions

CXCR2 plays a critical role in particle-induced osteolysis, and siCXCR2 may be a novel treatment for aseptic loosening.

A Novel Organ Culture Model of Mouse Intervertebral Disc Tissues

The intervertebral disc (IVD) is a fibrocartilaginous joint between two vertebral bodies. An IVD unit consists of a gelatinous central nucleus pulposus, encased by the annulus fibrosus, which is sandwiched between cartilaginous endplates (EPs). The IVD homeostasis can be disrupted by injuries, ageing and/or genetic predispositions, leading to degenerative disc disorders and subsequent lower back pain. The complex structure and distinct characteristics of IVDs warrant the establishment of robust in vitro IVD organ culture for studying the etiology and treatment of disc degeneration. Here, we isolate mouse lumbar IVDs and culture the minimal IVD units in submersion or suspension medium supplemented with 2% bovine serum or 10% fetal bovine serum (FBS). We find the minimal IVD units remain healthy for up to 14 days when cultured in submersion culture supplemented with 10% FBS. New bone formation in the EPs of the cultured IVDs can be assessed with calcein labeling. Furthermore, the cultured IVDs can be effectively transduced by recombinant adenovirus, and transgene expression lasts for 2 weeks. Thus, our findings demonstrate that the optimized IVD organ culture system can be used to study IVD biology and screen for biological factors that may prevent, alleviate and/or treat disc degeneration.

Cardiomyocyte-enriched protein CIP protects against pathophysiological stresses and regulates cardiac homeostasis

Cardiomyopathy is a common human disorder that is characterized by contractile dysfunction and cardiac remodeling. Genetic mutations and altered expression of genes encoding many signaling molecules and contractile proteins are associated with cardiomyopathy; however, how cardiomyocytes sense pathophysiological stresses in order to then modulate cardiac remodeling remains poorly understood. Here, we have described a regulator in the heart that harmonizes the progression of cardiac hypertrophy and dilation. We determined that expression of the myocyte-enriched protein cardiac ISL1-interacting protein (CIP, also known as MLIP) is reduced in patients with dilated cardiomyopathy. As CIP is highly conserved between human and mouse, we evaluated the effects of CIP deficiency on cardiac remodeling in mice. Deletion of the CIP-encoding gene accelerated progress from hypertrophy to heart failure in several cardiomyopathy models. Conversely, transgenic and AAV-mediated CIP overexpression prevented pathologic remodeling and preserved cardiac function. CIP deficiency combined with lamin A/C deletion resulted in severe dilated cardiomyopathy and cardiac dysfunction in the absence of stress. Transcriptome analyses of CIP-deficient hearts revealed that the p53- and FOXO1-mediated gene networks related to homeostasis are disturbed upon pressure overload stress. Moreover, FOXO1 overexpression suppressed stress-induced cardiomyocyte hypertrophy in CIP-deficient cardiomyocytes. Our studies identify CIP as a key regulator of cardiomyopathy that has potential as a therapeutic target to attenuate heart failure progression.

Trbp regulates heart function through microRNA-mediated Sox6 repression

Cardiomyopathy is associated with altered expression of genes encoding contractile proteins. Here we show that Trbp (Tarbp2), an RNA binding protein, is required for normal heart function. Cardiac-specific inactivation of Trbp (Trbp^cKO) caused progressive cardiomyopathy and lethal heart failure. Trbp loss of function resulted in upregulation of Sox6, repression of genes encoding normal cardiac slow-twitch myofiber proteins, and pathologically increased expression of skeletal fast-twitch myofiber genes. Remarkably, knockdown of Sox6 fully rescued the Trbp mutant phenotype, whereas Sox6 overexpression phenocopied the Trbp^cKO phenotype. Trbp inactivation was mechanistically linked to Sox6 upregulation through altered processing of miR-208a, which is a direct inhibitor of Sox6. Transgenic overexpression of miR-208a sufficiently repressed Sox6, restored the balance of fast- and slow- twitch myofiber gene expression, and rescued cardiac function in Trbp^cKO mice. Together, our studies reveal a novel Trbp-mediated microRNA processing mechanism in regulating a linear genetic cascade essential for normal heart function.

Percutaneous Vertebroplasty Combined with Percutaneous Pediculoplasty for Lytic Vertebral Body and Pedicle Lesions of Metastatic Tumors

Background: Percutaneous pediculoplasty (PP) consists of the injection of Poly(methyl methacrylate) (PMMA) into the fractured pedicle or lytic vertebral pedicle lesions, as a technique derived from vertebroplasty. Objectives: To evaluate the short-term analgesic effect of percutaneous vertebroplasty (PV) and percutaneous pediculoplasty (PP) in patients with lytic vertebral body and pedicle lesions of metastatic tumors. Study Design: Single-center retrospective observational study. Setting: An interventional pain management practice, a medical center, major metropolitan city, China. Methods: Single-center retrospective observational study of all patients managed with PV and PP for painful vertebral body and pedicle metastatic tumors between 2007 and 2013. For each patient, symptom duration and pain intensity were recorded. PP was performed under local analgesia, in the prone position, with C-arm fluoroscopy guidance. The mixture of PMMA and Doxorubicin was delivered into the vertebral body with a non-beveled needle for the initial treatment followed by the mixture delivery into the lytic pedicle during needle withdrawal. Results: Nine patients (5 women, 4 men) were enrolled in the study with a mean age of 65.9 years (range 57 – 75). Technical success was defined as the ability to access the lesion using the approach. A positive clinical response for pain relief was achieved in these patients in whom vertebroplasty and pediculoplasty had been performed. Pain level was not significantly reduced in 3 patients in whom just vertebroplasty has been performed because the medial wall of the pedicle was destroyed by the metastatic lesion. Limitations: This study is limited by its sample size. Conclusions: PV and PP via the transpedicular approach for infiltrated vertebral bodies and infiltrated pedicles of metastatic tumors may be considered a valid therapeutic option. Key words: Percutaneous pediculoplasty, percutaneous vertebroplasty, lytic pedicular lesions, bone cement

Percutaneous vertebroplasty combined with percutaneous pediculoplasty for lytic vertebral body and pedicle lesions of metastatic tumors

BACKGROUND

Percutaneous pediculoplasty (PP) consists of the injection of Poly(methyl methacrylate) (PMMA) into the fractured pedicle or lytic vertebral pedicle lesions, as a technique derived from vertebroplasty.

OBJECTIVES

To evaluate the short-term analgesic effect of percutaneous vertebroplasty (PV) and percutaneous pediculoplasty (PP) in patients with lytic vertebral body and pedicle lesions of metastatic tumors.

STUDY DESIGN

Single-center retrospective observational study.

SETTING

An interventional pain management practice, a medical center, major metropolitan city, China.

METHODS

Single-center retrospective observational study of all patients managed with PV and PP for painful vertebral body and pedicle metastatic tumors between 2007 and 2013. For each patient, symptom duration and pain intensity were recorded. PP was performed under local analgesia, in the prone position, with C-arm fluoroscopy guidance. The mixture of PMMA and Doxorubicin was delivered into the vertebral body with a non-beveled needle for the initial treatment followed by the mixture delivery into the lytic pedicle during needle withdrawal.

RESULTS

Nine patients (5 women, 4 men) were enrolled in the study with a mean age of 65.9 years (range 57 - 75). Technical success was defined as the ability to access the lesion using the approach. A positive clinical response for pain relief was achieved in these patients in whom vertebroplasty and pediculoplasty had been performed. Pain level was not significantly reduced in 3 patients in whom just vertebroplasty has been performed because the medial wall of the pedicle was destroyed by the metastatic lesion.

LIMITATIONS

This study is limited by its sample size.

CONCLUSIONS

PV and PP via the transpedicular approach for infiltrated vertebral bodies and infiltrated pedicles of metastatic tumors may be considered a valid therapeutic option.

Anterior retropharyngeal approach to C1 for percutaneous vertebroplasty under C-arm fluoroscopy

BACKGROUND CONTEXT

Percutaneous vertebroplasty (PVP) has proven to be a valuable palliative treatment option for patients with medically refractory painful osteolytic metastases of the spine. Percutaneous vertebroplasty of the atlas has been reported in only seven articles and has been performed with different techniques and approaches.

PURPOSE

To describe the technique we used to perform PVP of a lytic lesion of the lateral mass of C1 via anterior retropharyngeal approach guided by C-arm fluoroscopy.

STUDY DESIGN

A technical report.

PATIENT SAMPLE

It included a 75-year-old man with known metastatic lung carcinoma and incapacitating right suboccipital and neck pain refractory to conventional medical treatment. Radiologic evaluation showed revealed osteolytic destruction of C1 and C2, mainly invading the right lateral mass of C1 and the vertebral body of C2.

OUTCOME MEASURES

The right suboccipital and neck pain was measured using the visual analog scale (VAS).

METHODS

Under C-arm fluoroscopy, a novel anterior retropharyngeal approach, through the vertebral body of C2 into the metastatic osteolytic vertebral lesion of C1, was performed to achieve the PVP in C1 followed by a PVP in C2.

RESULTS

Immediately after the operation, the patient reported substantial pain relief (from VAS 9/10 preoperatively to 3/10). At 12 hours postoperatively, the range of motion was also improved. There were no surgery-related complications. The immediately postoperative cervical plain film and computed tomography scan showed adequate filling of the osteolytic lesion without the obvious leakage of bone cement. Clinical follow-up at 3 months revealed that this pain condition was improved and maintained (VAS 1/10).

CONCLUSIONS

When the transoral approach is unsuitable or contraindicated, the anterior retropharyngeal approach could be an efficacious alternative in selected patients with C1 metastasis, providing adequate filling of bone cement and significant pain relief. Based on our preliminary exploration, only assisted by C-arm fluoroscopy, this approach is feasible to achieve PVP in C1 under local anesthesia and intravenous analgesia. Nevertheless, when considering the substantial potential risks, this technically challenging procedure should be performed by experienced operators.

Sacroiliac fascial lipocele could be a neglected cause of lumbosacral pain: case study of percutaneous endoscopic treatment

The pathological entities commonly associated with lumbosacral pain are the intervertebral discs, facet joints or surrounding muscle. However, in the absence of diagnostic confirmation of the aforementioned structures, the diagnosis may become confusing and intractable. Sacroiliac fascial lipocele (SFL), namely, pannicular hernia, could be a neglected cause. First reported by Ficarra et al in 1952, it was highlighted by the formation of lipocele in the sacroiliac fascia. Mostly, it could be spontaneously eliminated under conservative therapy. However, for intractable pain, surgical intervention may be the only choice. We will first present a typical case of SFL which was treated by percutaneous endoscopic surgery. Ultimately, a satisfactory outcome was achieved and maintained at 12 months follow-up. It is important to distinguish SFL some cases with lumbosacral back pain. Detailed physical examination, superficial ultrasonography and diagnostic nerve block are extremely valuable for acquiring a precise diagnosis. Overall, when considering the clinical outcome of such cases and the foregoing benefits, percutaneous endoscopic treatment could be an efficacious alternative treatment for SFL-related lumboscral back pain.

Targeting BMP9-promoted human osteosarcoma growth by inactivation of notch signaling

Osteosarcoma (OS) is the most common primary malignancy of bone and is usually associated with poor prognosis due to its high incidence of metastasis and chemoresistance. Molecular pathogenesis of OS is poorly understood. We previously showed that OS cells are refractory to BMP9-induced osteogenesis and respond favorably to proliferation and tumor growth. Here we investigate if Notch signaling mediates the BMP9-promoted cell proliferation and tumor growth of human osteosarcoma (OS). We find that the expression of Notch1, Notch2, Notch3, DLL1, JAG1 and JAG2 is readily detected in most of the tested OS cell lines. BMP9-promoted OS cell proliferation, migration, and cell cycle S/G2 progression are effectively inhibited by a dominant-negative mutant of Notch1 (dnNotch1) or the γ-secretase inhibitor Compound E (ComE). Furthermore, BMP9-promoted tumor growth and osteolytic lesions in vivo are significantly inhibited by dnNotch1. BMP9 up-regulates the expression of Notch1, Notch3, DLL1, and JAG1 in OS cells. Accordingly, BMP9 stimulation induces a nuclear accumulation of NICD, which is blocked by ComE. Our results demonstrate that BMP9-promoted OS proliferation and tumor growth is at least in part mediated by Notch signaling, suggesting that osteogenic BMPs may function as upstream regulators of Notch signaling in OS tumorigenesis. Thus, pharmacologic intervention of Notch signaling may be explored as a new therapeutic strategy for human OS tumors.