POU Class 2 Homeobox Associating Factor 1, as a Hub Candidate Gene in OP, Relieves Osteoblast Apoptosis.

Increasing evidence suggests that osteoblast apoptosis contributes to the pathogenesis of postmenopausal osteoporosis (PMOP). This study aimed to identify a hub gene associated with osteoporosis (OP) progression and its functions. We utilized the GSE68303 expression dataset from GEO database and conducted weighted gene co-expression network analysis (WGCNA) to investigate changes in co-expressed genes between sham and ovariectomy (OVX) groups. Differentially expressed genes (DEGs) were identified using the "limma" R package on GSE68303 dataset. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed using the DAVID database. A protein-protein interaction (PPI) network was constructed using the STRING database, which was visualized by Cytoscape software. The top ten hub genes were screened using the Cytohubba plugin, among which POU class 2 homeobox associating factor 1 (POU2AF1), an OP-related hub gene, showed a significant increase in OVX-induced mouse model based on immunohistochemical staining. Inhibition of POU2AF1 suppressed cell viability, induced cell cycle arrest at the G1 phase, and promoted osteoblast apoptosis as demonstrated by CCK-8 assay, flow cytometry analysis, and TUNEL assay. Moreover, overexpression of POU2AF1 decreased cleaved caspase-3/-8/-9 expression while increasing cyclinD1 and Ki67 expression in MC3T3-E1 and hFOB1.19 cells. Therefore, POU2AF1 may serve as a potential diagnostic biomarker for slowing down the progression of OP.

Extracellular vesicles from bone marrow mesenchymal stem cells alleviate osteoporosis in mice through USP7-mediated YAP1 protein stability and the Wnt/ß-catenin pathway.

Mesenchymal stem cells (MSCs) and their derived extracellular vesicles (EVs) have emerged as promising tools for promoting bone regeneration. This study investigates the functions of EVs derived from bone marrow-derived MSCs (BMSCs) in osteoporosis (OP) and the molecular mechanism. EVs were isolated from primary BMSCs in mice. A mouse model with OP was induced by ovariectomy. Treatment with EVs restored bone mass and strength, attenuated trabecular bone loss and cartilage damage, and increased osteogenesis while suppressing osteoclastogenesis in ovariectomized mice. In vitro, the EVs treatment improved the osteogenic differentiation of MC-3T3 while inhibiting osteoclastic differentiation of RAW264.7 cells. Microarray analysis revealed a significant upregulation of ubiquitin specific peptidase 7 (USP7) expression in mouse bone tissues following EV treatment. USP7 was found to interact with Yes1 associated transcriptional regulator (YAP1) and stabilize YAP1 protein through deubiquitination modification. YAP1-related genes were enriched in the Wnt/ß-catenin signaling, and overexpression of YAP1 promoted the nuclear translocation of ß-catenin. Functional experiments underscored the critical role of maintaining USP7, YAP1, and ß-catenin levels in the pro-osteogenic and anti-osteoclastogenic properties of the BMSC-EVs. In conclusion, this study demonstrates that USP7, delivered by BMSC-derived EVs, stabilizes YAP1 protein, thereby ameliorating bone formation in OP through the Wnt/ß-catenin activation.

Transforaminal Endoscopic Discectomy for Thoracolumbar Disc Herniation: A Retrospective Study and Technical Note.

BACKGROUND: Thoracolumbar disc herniation (TLDH) is a rare disorder with unique characteristics that can result in undesirable surgical outcomes after traditional discectomy. In view of the widespread use of transforaminal endoscopic discectomy for lower lumbar disc herniation, we investigated treatment of TLDH by this procedure. The purpose of this study was to evaluate the clinical efficacy of transforaminal endoscopic discectomy for treating TLDH and share our technical experience. METHODS: We retrospectively evaluated the clinical data of 19 patients who had undergone transforaminal endoscopic discectomy for TLDH in our institution between April 2018 and July 2021. Operation time, follow-up time, blood loss, postoperative hospital stay, visual analog scale scores for low-back and leg pain, and Japanese Orthopedic Association (JOA) scores were evaluated. RESULTS: The differences between preoperative and postoperative JOA and visual analog scale scores were significant (P < 0.05). According to the JOA scores, 14 of the 19 patients had excellent improvement, 3 had good improvement, and 2 had fair improvement; thus, the rate of satisfactory improvement was 89.5%. CONCLUSIONS: Operation time, blood loss, postoperative hospital stay, and surgical outcomes were favorable. Transforaminal endoscopic discectomy is an ideal surgical procedure for treating TLDH.

Pyogenic spondylitis caused by Escherichia coli: A case report and literature review.

BACKGROUND: Pyogenic spondylitis is often manifested as atypical low back pain and fever, which makes it easy to be confused with other diseases. Here we report a case of pyogenic spondylitis and describe the diagnosis and treatment based on the related literature. CASE SUMMARY: The reported case suffered from pyogenic spondylitis caused by Escherichia coli and complicated with bacteremia and psoas abscess. Acute pyelonephritis was initially diagnosed due to atypical symptoms. Symptoms were improved from antibiotic treatment while developing progressive lower limb dysfunction. One month post the admission, the patient underwent anterior lumbar debridement + autogenous iliac bone graft fusion + posterior percutaneous screw-rod internal fixation, and received 6 wk of antibiotic treatment after the operation. Reexamination 4 mo post the operation showed that the patient had no evident pain in the waist, and walked well with no evident dysfunction of lower limbs. CONCLUSION: Here we describe the application value of several imaging examinations, such as X-ray, computed tomography and magnetic resonance imaging, and certain tests like erythrocyte sedimentation rate and C-reactive protein in the clinical treatment of pyogenic spondylitis. This disease requires early diagnosis and treatment. Sensitive antibiotics should be used in early stages and surgical intervention should be taken if necessary, which may help for a speedy recovery and prevent the occurrence of severe complications.

Comparison of minimally invasive transforaminal lumbar interbody fusion and endoscopic lumbar interbody fusion for lumbar degenerative diseases: a retrospective observational study.

BACKGROUND: Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and endoscopic lumbar interbody fusion (Endo-LIF) are both minimally invasive interbody fusion procedures for lumbar degenerative diseases. In this study, we attempted to compare the clinical efficacy and postoperative outcomes of MIS-TLIF and Endo-LIF for lumbar degenerative diseases. METHODS: The study cohort comprised 99 patients with lumbar degenerative diseases treated by MIS-TLIF or Endo-LIF from January 2019 to July 2021. The clinical outcomes (visual analogue scale (VAS), Oswestry disability index (ODI), and MacNab criteria) preoperatively, 1 month postoperatively, 3 months postoperatively, and 1 year postoperatively were compared between the two groups. RESULTS: There were no significant differences between the two groups in sex, age, disease duration, affected spine segment, and complications (P > 0.05). The operation time was significantly longer in the Endo-LIF group than the MIS-TLIF group (155.25 ± 12.57 vs. 123.14 ± 14.50 min; P < 0.05). However, the Endo-LIF group had a significantly smaller blood loss volume (61.79 ± 10.09 vs. 259.97 ± 14.63 ml) and shorter hospital stay (5.46 ± 1.11 vs. 7.06 ± 1.42 days) than the MIS-TLIF group. In both groups, the ODI and VAS scores for lower back pain and leg pain were significantly lower at each postoperative timepoint than preoperatively (P < 0.05). Although there were no significant differences between the two groups in the ODI and VAS scores for lower back pain and leg pain (P > 0.05), the VAS for lower back pain was lower in the Endo-LIF group than the MIS-TLIF group at each postoperative timepoint. The MacNab criteria showed that the improvement rate was 92.2% in the MIS-TLIF group and 91.7% in the Endo-LIF group, with no significant difference between the two groups (P > 0.05). CONCLUSIONS: There were no significant differences in short-term surgical outcomes between the MIS-TLIF and Endo-LIF groups. Compared with the MIS-TLIF group, the Endo-LIF group incurred less damage to surrounding tissues, experienced less intraoperative blood loss, and had less lower back pain, which is more conducive to recovery.

METTL14 upregulates TCF1 through m6A mRNA methylation to stimulate osteogenic activity in osteoporosis.

Alteration of N6-methyladenosine (m6A) is closely linked to spanning biological processes including osteoporosis (OP) development. This research focuses on the function of methyltransferase like 14 (METTL14) in bone turnover and its interaction with T cell factor 1 (TCF1). A mouse model of OP was established by ovariectomy (OVX). The bone mass parameters were evaluated by micro-CT analysis. Mouse MC3T3-E1 cells and mouse bone marrow macrophages (BMMs) were induced for osteogenic or osteoclastic differentiation, respectively, for in vitro experiments. The osteogenesis or osteoclasis activity was analyzed by measuring the biomarkers such as OPG, ALP, NFATC1, CTSK, RANKL, and TRAP. RT-qPCR and IHC assays identified reduced METTL14 expression in bone tissues of osteoporotic patients and ovariectomized mice. Artificial METTL14 overexpression increased bone mass of mice and promoted osteogenesis whereas suppressed osteoclasis both in vivo and in vitro. METTL14 promoted TCF1 expression through m6A mRNA methylation, and TCF1 increased the osteogenic activity by elevating the protein level of RUNX2, a key molecule linked to bone formation. In rescue experiments, TCF1 restored the RUNX2 level and osteogenic activity of cells suppressed by METTL14 silencing. In summary, this research demonstrates that METTL14 plays a protective role against OP by promoting the TCF1/RUNX2 axis.

Protective effects of Tripterygium glycoside on IL-1ß-induced inflammation and apoptosis of rat chondrocytes via microRNA-216a-5p/TLR4/NF-κB axis.

BACKGROUND: This study is designed to fill the research gap concerning the efficacy of Tripterygium glycoside (TG) on Interleukin-1ß (IL-1ß)-induced inflammation and injury in chondrocytes. METHODS: Chondrocytes were isolated from Sprague-Dawley rats. After the treatment with IL-1ß and TG and transfection, the viability and apoptosis of chondrocytes were determined via Cell Counting Kit-8 (CCK-8) assay and flow cytometry. The levels of inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-8 were determined by enzyme-linked immunosorbent assay (ELISA). Relative expression levels of potential microRNAs (miRNAs, miRs) that may target toll-like receptor 4 (TLR4), as well as apoptosis- and TLR4/nuclear factor-κB (TLR4/NF-κB) pathway-associated factors were quantified using quantitative real-time (qRT) PCR and western blot. The targeting relationship between miR-216a-5p and TLR4 was predicted by TargetScan and further confirmed by dual-luciferase reporter assay. RESULTS: The viability was reduced yet the apoptosis and inflammation were promoted in IL-1ß-treated chondrocytes, where upregulation of Bax, Cleaved caspase 3, TLR4, Myeloid differentiation factor 88 (MyD88), phosphorylation of P65 and IκBα yet downregulation of Bcl-2 and IκBα were evidenced. Strikingly, the above changes were reversed by TG. TG also offset the effects of IL-1ß on repressing the expression of miR-216a-5p, the miRNA targeting TLR4. Additionally, TLR4 overexpression neutralized the impacts of TG upon viability, apoptosis, and TLR4 expression in IL-1ß-treated chondrocytes, while all these effects induced by TLR4 overexpression could be restored by miR-216a-5p. CONCLUSIONS: TG protects chondrocytes against IL-1ß-induced inflammation and apoptosis via miR-216a-5p/TLR4/NF-κB axis.

Morphometric Analysis of the Ureter with Respect to Lateral Lumbar Interbody Fusion Using Contrast-Enhanced Computed Tomography.

OBJECTIVE: To analyze the anatomical location of the ureter in relation to lateral lumbar interbody fusion and evaluate the potential risk of ureteral injury. METHODS: One hundred eight patients who performed contrast-enhanced computed tomographic scans were enrolled in this study. The location of the ureter from L2-L3 to L4-L5 was evaluated. The distances between the ureter and psoas muscle, intervertebral disc, and retroperitoneal vessels were also recorded bilaterally. RESULTS: Over 30% of the ureters were close to the working corridor of extreme lumbar interbody fusion at L2-L3. Most of the ureters were close to working corridor of oblique lumbar interbody fusion, especially at L4-L5. The distance from the ureter to the great vessels on the left side was significantly narrowing from L2-L3 to L4-L5 (28.8±9.5 mm, 22.0±8.0 mm, 15.5±8.4 mm), and it was significantly larger than that on the right side (12.3±6.1 mm, 7.4±5.7 mm, 5.4±4.4 mm). CONCLUSION: Our findings indicate that the location of the ureter varies widely among individuals. To avoid unexpected damage to the ureter, it is imperative to directly visualize it and verify the ureter is not in the surgical pathway during lateral lumbar interbody fusion.

Clinical Effect of Catgut Embedding plus Warm Needle Moxibustion on Improving Inflammation and Quality of Life of Knee Osteoarthritis Patients.

Objective: To clarify influence of catgut embedding plus warm needle moxibustion on improving inflammation and quality of life of knee osteoarthritis patients. Materials and Methods: The data of 120 patients with knee osteoarthritis admitted to our hospital from June 2018 to June 2021 were used for retrospective analysis. Patients were divided into control group and observation group in a random manner, with 60 cases each. The control group was orally administrated with one diclofenac sodium sustained-release tablet (100 mg) once a day, for 8 courses with 7 days for each course. The observation group underwent catgut embedding plus warm needle moxibustion. Results: The Western Ontario and McMaster Universities Arthritis Index and gonitis Lequesne scores in two groups were decreased after treatment and were lower in observation group than control group (P < 0.05). Quality of life scores presented elevation after treatment and were higher in observation group than control group (P < 0.05). Curative efficacy presented no difference between two groups (P > 0.05), while clinical cure rate was higher in observation group than control group (X2 = 8.257, P = 0.006). Conclusion: Warm needle moxibustion plus functional exercise can effectively improve clinical symptoms of knee osteoarthritis patients, and improve their knee joint function and inflammatory response.

In Situ Observation of Thermoelastic Martensitic Transformation of Cu-Al-Mn Cryogenic Shape Memory Alloy with Compressive Stress.

The thermoelastic martensitic transformation and its reverse transformation of the Cu-Al-Mn cryogenic shape memory alloy, both with and without compressive stress, has been dynamically in situ observed. During the process of thermoelastic martensitic transformation, martensite nucleates and gradually grow up as they cool, and shrink to disappearance as they heat. The order of martensite disappearance is just opposite to that of their formation. Observations of the self-accommodation of martensite variants, which were carried out by using a low temperature metallographic in situ observation apparatus, showed that the variants could interact with each other. The results of in situ synchrotron radiation X-ray and metallographic observation also suggested there were some residual austenites, even if the temperature was below Mf, which means the martensitic transformation could not be 100% accomplished. The external compressive stress would promote the preferential formation of martensite with some orientation, and also hinder the formation of martensite with other nonequivalent directions. The possible mechanism of the martensitic reverse transformation is discussed.

Radiosensitizing Effect of Celastrol by Inhibiting G2/M Phase Arrest Induced by the c-myc Gene of Human SW1353 Chondrosarcoma Cells: Network and Experimental Analyses.

OBJECTIVE: Studies have unveiled that the components of Tripterygium wilfordii Hook F (TWHF) such as celastrol could attenuate apoptosis and proliferation of various tumor cells. This study is focused on the radiosensitization effect and apoptotic pathways of celastrol via the inhibition of the c-myc gene and the influence of which combined with radiotherapy on the proliferation, apoptosis, invasion, and metastasis of chondrosarcoma cells. METHODS: A variety of bioinformatic tools were applied to explore the expression level and prognosis of the c-myc gene in different tumor cells and chondrosarcoma cells. We used pharmacology network to analyze the components, pathways, targets, molecular functions of TWHF and explore the relevant effective components over the MYC gene. Clone formation assay, CCK-8 assay, flow cytometry, and transwell migration assay were applied to detect the effects of celastrol on the expression of c-myc gene, cell apoptosis, and cell cycle. Radiation therapy was used to observe the radiosensitization effect of celastrol on chondrosarcoma. RESULTS: This study shows that the c-myc gene is overexpressed in various tumor cells and bone tumor cells to varying degrees. Celastrol can significantly inhibit the expression of the c-myc gene, induce G2/M phase arrest through regulation of G2/M phase-related proteins, and promote SW1353 cell apoptosis through the mitochondrial signaling pathway. In addition, we also found that the use of triptorubin to inhibit c-myc gene expression in combination with radiotherapy can increase the osteosarcoma cells' apoptosis rate through the mitochondrial signaling pathway significantly. CONCLUSIONS: Our study validated the radiosensitization effect of celastrol through knocking down the expression of the c-myc gene to induce G2/M phase arrest and provides a new idea for the treatment of refractory or recurrent chondrosarcoma that is not sensitive to radiotherapy.

Peptide 11R­VIVIT promotes fracture healing in osteoporotic rats.

Osteoporotic fracture healing is a complex clinical issue. The present study was conducted to investigate the repair properties of 11R­VIVIT on osteoporotic fractures and to examine the potential effects of 11R­VIVIT on osteoporotic bone marrow­derived mesenchymal stem cells (BMSCs), A rat model of osteoporotic femoral fracture was established, and the effects of the daily local injection of 11R­VIVIT or saline on fracture repairing were evaluated by micro­CT scans and H&E staining. Moreover, BMSCs from osteoporotic rats were treated with 11R­VIVIT, and the osteogenic and adipogenic differentiation of BMSCs was evaluated. The results revealed that 11R­VIVIT promoted bone formation and increased fracture healing. In addition, 11R­VIVIT promoted the differentiation of osteoporotic BMSCs into osteoblasts rather than adipocytes. Furthermore, mechanistic analysis revealed that 11R­VIVIT promoted autophagy by blocking the protein kinase B (AKT)/nuclear factor of activated T­cells (NFATc1) signaling pathway. Consistently, the activation and inhibition of autophagy using rapamycin and LY294002 confirmed the regulatory effects of 11R­VIVIT on autophagy. On the whole, the findings of the present study demonstrate that 11R­VIVIT promotes fracture healing in osteoporotic rats and enhances the osteogenic differentiation of osteoporotic BMSCs by dysregulating the AKT/NFATc1 signaling pathway.

Neuropilin and tolloid-like 2 regulates the progression of osteosarcoma.

Neuropilin and tolloid-like 2 (NETO2) is aberrantly expressed in various malignancies. However, its role in osteosarcoma (OS) remains to be elucidated. This study aimed to identify the function of NETO2 in OS cells. The expression of NETO2 in sarcoma tissues was determined using the GEPIA database, and the mRNA and protein expression of NETO2 in OS cells and OS tissue was also assessed. The biological effects of NETO2 on OS cells were determined by overexpressing and downregulating NETO2. Cell proliferation, invasion, migration, colony formation, and epithelial-mesenchymal transition in OS cells were evaluated. Consistent with the GEPIA database, expression of NETO2 was upregulated in human OS samples and cell lines. NETO2 overexpression not only promoted the proliferation, colony formation, invasion, and epithelial-mesenchymal transition of OS cells, but also activated the PI3K/AKT signaling. NETO2 downregulation resulted in opposite effects. Furthermore, after using an AKT inhibitor, the effects of NETO2 on OS cells were attenuated. In conclusion, this study showed that NETO2 functions as an oncogene of osteosarcomas by activating the PI3K/AKT pathway.

Loss of Reduction after Cephalomedullary Nail Fixation of Intertrochanteric Femoral Fracture: A Brief Report.

OBJECTIVE: At present, cephalomedullary nail is the most frequently used implant in the management of intertrochanteric fractures around the world. The implant design and fixation techniques of the cephalomedullary nail have been continuously improved to ensure uncomplicated bone union during the past decade. However, a degree of reduction loss during bone healing is still not rare in clinical work. Many attributed this complication to misoperation during the surgery and hold that a series of techniques and tips could help to avoid the loss of reduction. However, until now there has been no research to explore whether the reduction loss after the operation can be fully prevented in the best cases. The purposes of the study are as follows: (i) to evaluate the efficiency of the current established CMN techniques; (ii) to quantify the loss of reduction under an appropriately implanted CMN to anatomically realigned intertrochanteric fractures; and (iii) to explore the possible underlying causes for the inevitable loss of reduction. METHODS: In the retrospective study, 163 consecutive cases with the intertrochanteric fractures fixed with standard cephalomedullary nail technique were reviewed. The anatomical reduction and optimal positioning of the nail were confirmed by postoperative imaging. The fracture types ranged from 31-A1.1-2.3 according to the OTA/AO fracture classification. One hundred and fifteen cases with stable fracture types (31A1.1-2.1) were allocated to Group A, and 48 cases with unstable 31A2.2-2.3 fracture types were allocated to Group B. The radiological measurements included femoral neck shortening, loss of the neck-shaft angle, cutout, and cut-through of the blade. The outcomes between postoperative and 1 year after the operation were evaluated and compared. RESULTS: The patients consisted of 66 males and 97 females with an average age of 69.4 (range: 46-78, SD: 14.6) years. At the 1-year follow-up, no fixation failure or nonunion was observed in each group. The mean femoral neck shortening and loss of the neck-shaft angle were 4.47 mm (range: 0.43-17.68, SD: 3.71) and 5.4° (range: 0.51-19.10, SD: 3.58) separately. The mean cutout and cut-through were 1.84 mm (range: 0.24-11.30, SD: 2.33) and 1.25 mm (range: 0.51-10.29, SD: 1.74). The average femoral neck shortening and loss of the neck-shaft angle were higher in Group B than Group A. Among the 23 cases with the femoral neck shortening more than 10 mm, 19 cases (16.5%) were from Group A and four cases (8.3%) were from Group B. There were nine (7.8%) cases with the loss of the neck-shaft angle more than 10° in Group A and six (12.5%) cases in Group B. CONCLUSIONS: Current established CMN techniques are efficient in treating intertrochanteric femoral fracture. However, even with currently consensual techniques of cephalomedullary nail, the process of fracture healing still risks the loss of reduction, although the migration of the blade could be minimized. This situation may associate with the intrinsic design of the CMN and further improvement is still needed.

Giant Cell Tumor of Tendon Sheath with Tarsal Bones and Intertarsal Joint Invasion: A Case Report.

The giant cell tumor of tendon sheath (GCTTS) is a benign lesion most commonly attached to the tendons and bones of the fingers, hands, and wrists. The involvement of GCTTS to the foot is uncommon. The GCTTS invading tarsal bones and intertarsal joints is not described yet, and the appropriate diagnosis and treatment remain unclear. We report a case of GCTTS with the involvement of tarsal bones and intertarsal joint. Computed tomography scan and magnetic resonance imaging were used to further diagnose and evaluate the quality and range of tumor. The patient was treated with surgical excision of the tumor without application of bone graft. After adequate clearance of the tumor, the patient returned to an asymptomatic walk in 3 months. No malfunction, fracture, or tumor recurrence was found in 2-years follow-up. This report includes clinical, radiologic, histologic diagnostic, and surgical challenges in an unexpected lesion and a review of the literature.

Unilateral percutaneous endoscopic debridement and drainage for lumbar infectious spondylitis.

BACKGROUND: The treatment of lumbar infectious spondylitis is controversial. In this study, we attempted to demonstrate that unilateral percutaneous endoscopic debridement with physiologic saline and negative pressure drainage postoperatively may achieve a satisfactory result in lumbar infectious spondylitis. METHODS: We retrospectively analyzed 17 patients with lumbar infectious spondylitis who underwent percutaneous endoscopic debridement and drainage (PEDD) through a posterolateral transforaminal approach. Each biopsy specimen was submitted without delay after surgery and examined for microorganisms and evaluated histopathologically. Patients were assessed by careful physical examination, MacNab criteria, Oswestry Disability Index (ODI), visual analog scale (VAS), regular serological tests, imaging studies for clinical function, and patient satisfaction. RESULTS: Of the 17 patients, 14 (82.4%) had satisfactory relief of their back pain according to MacNab criteria at 1 week after PEDD. Three patients (17.6%) who had advanced infections with multilevel involvement and paraspinal abscesses underwent anterior debridement and autograft interbody fusion with instrumentation within 2 weeks. However, there were no other severe surgery-related complications. Causative bacteria were identified in most cases, and Staphylococcus aureus was the most prevalent strain. CONCLUSIONS: Unilateral PEDD with physiological saline or empirical antibiotics did not disrupt lumbar stability and avoided the important intraspinal structures such as the dural sac and nerve roots. It not only had a high rate of identification of the causative pathogen, but also provided effective infection control and pain relief. PEDD may be a useful technique for treatment of lumbar infectious spondylodiscitis patients who have no severe deformities and are unable to undergo the conventional anterior surgery due to poor health or advanced age.

Effect of CXCR4 on Apoptosis in Osteosarcoma Cells via the PI3K/Akt/NF-κß Signaling Pathway.

BACKGROUND/AIMS: Osteosarcoma, the most common primary bone malignancy, arises from primitive transformed cells of mesenchymal origin with the worldwide increasing morbidity and mortality. Previous studies found apoptosis of osteosarcoma cells was essential for an effective manner to improve the progress of osteosarcoma, and CXCR4 has been demonstrated to be relevant with various tumor progress and metastasis. METHODS: The proliferation of cells transfected with CXCR4 shRNA and control shRNA were measured by BrdU assay. Apoptosis was detected by flow cytometry. Apoptotic protein expression levels were detected by Western blot. Caspase activity was detected by Colorimetric Assay Kits using microplate reader. Activation of NF-κß signaling after CXCR4 down-regulation in osteosarcoma cells was examined by constructing NF-κß promoter luciferase reporter plasmid. The expression and activation of NF-κß Signaling relevant protein were analyzed to investigate the relationship between Akt and NF-κß signaling after the down-regulation of CXCR4 in osteosarcoma cells. RESULTS: Down-regulation of CXCR4 significantly reduced the cell proliferation, while remarkably increased the cell apoptosis and apoptotic protein expression levels in osteosarcoma cells. Furthermore, down-regulation of CXCR4 induced cell apoptosis was caspase dependent in osteosarcoma cells. This study also showed CXCR4 down-regulation induced apoptosis through inhibiting PI3K/Akt/NF-κß signaling pathway. In addition, endoplasmic reticulum stress (ERS) activation was involved in cell apoptosis induced down-regulation of CXCR4. Knockdown of partial ERS relevant proteins followed down-regulation of CXCR4 significantly inhibited cell apoptosis and the apoptotic protein expression levels. CONCLUSIONS: Taken together, the results demonstrated that down-regulation of CXCR4 could induce apoptosis of human osteosarcoma cells through inhibiting PI3K/Akt/NF-κß signaling pathway, indicating that CXCR4 could be vital for the clinical therapy of osteosarcoma.

Paravertebral injection of botulinum toxin-A reduces lumbar vertebral bone quality.

Aging has been associated with decreases in muscle strength and bone quality. In older patients, paravertebral muscle atrophy tends to coincide with vertebral osteoporosis. The purpose of this study was to investigate the effects of a paravertebral injection of botulinum toxin-A (BTX) on paravertebral muscle atrophy and lumbar vertebral bone quality. Forty 16-week-old female SD rats were randomly divided into four groups: (1) a control group (CNT); (2) a resection of erector spinae muscles group (RESM); (3) a botulinum toxin-A group (BTX), treated with 5U BTX by local injection into the paravertebral muscles bilaterally; and (4) a positive control group (OVX), treated by bilateral ovariectomy. Rats were sacrificed at 12 weeks post-surgery, and the lumbar vertebrae (L3-L6) were collected. Micro-CT scans showed that rats in the three experimental groups-particularly the OVX rats-had fewer trabeculae and trabecular connections than rats in the CNT group. BMD was significantly lower in rats in the OVX, RESM, and BTX groups than in the CNT group (p < 0.01). Vertebral compression testing revealed significantly lower maximum load, energy absorption, maximum stress, and elastic modulus values in the three experimental groups compared with the CNT group (p < 0.01); these parameters were lowest in the OVX group (p < 0.05). Our results demonstrate that local BTX injection causes sufficient muscle atrophy and dysfunction to result in local lumbar vertebral bone loss and quality deterioration in a model of paravertebral muscle atrophy. Clinical Significance: The muscular tissues surrounding the lumbar vertebrae should be preserved during clinical surgery to avoid loss of bone quality and mass in the adjacent bone. Maintaining paravertebral muscle strength is an important consideration for patients with early osteoporosis. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2664-2670, 2018.

Triptolide inhibits the growth of osteosarcoma by regulating microRNA-181a via targeting PTEN gene in vivo and vitro.

We aimed to study the anti-tumor effects of triptolide on osteosarcoma and the related molecular mechanisms. The cell viability, apoptosis portion, tumor size, tumor weight, and invasion of osteosarcoma cells were determined. The relative level of microRNA-181 in osteosarcoma tissues and the adjacent tissues was determined by quantitative real-time reverse transcription polymerase chain reaction. The target gene of microRNA-181a was determined and verified by luciferase report assay. At last, osteosarcoma cells were treated with triptolide and triptolide + microRNA-181a mimics to verify the relationship between triptolide and microRNA-181a. Triptolide inhibited the cell viability, promoted the apoptosis, decreased the tumor size and weight, and reduced the invasion of osteosarcoma cells. The level of microRNA-181a in osteosarcoma cells decreased significantly after treating with triptolide, and the relative level of microRNA-181a in osteosarcoma tissues was markedly higher than that in the adjacent tissues. PTEN was reported and verified the direct target gene of microRNA-181a. The overexpression of microRNA-181a decreased the inhibition of triptolide on osteosarcoma proliferation and promotion on osteosarcoma apoptosis. In conclusion, triptolide inhibited cell growth and invasion of osteosarcoma by regulating microRNA-181a via targeting PTEN gene in vivo and vitro.