The impact of apparent temperature on the emergency visits for traumatic fractures in Hangzhou, China.

BACKGROUND: Traumatic fractures occur frequently worldwide. However, research remains limited on the association between short-term exposure to temperature and traumatic fractures. This study aims to explore the impact of apparent temperature (AT) on emergency visits (EVs) due to traumatic fractures. METHODS: Based on EVs data for traumatic fractures and the contemporary meteorological data, a generalized Poisson regression model along with a distributed lag nonlinear model (DLNM) were undertaken to determine the impact of AT on traumatic fracture EVs. Subgroup analysis by gender and age and sensitivity analysis were also performed. RESULTS: A total of 25,094 EVs for traumatic fractures were included in the study. We observed a wide "J"-shaped relationship between AT and risk of traumatic fractures, with AT above 9.5 °C positively associated with EVs due to traumatic fractures. The heat effects became significant at cumulative lag 0-11 days, and the relative risk (RR) for moderate heat (95th percentile, 35.7 °C) and extreme heat (99.5th percentile, 38.8 °C) effect was 1.311 (95% CI: 1.132-1.518) and 1.418 (95% CI: 1.191-1.688) at cumulative lag 0-14 days, respectively. The cold effects were consistently non-significant on single or cumulative lag days across 0-14 days. The heat effects were higher among male and those aged 18-65 years old. The sensitivity analysis results remained robust. CONCLUSION: Higher AT is associated with cumulative and delayed higher traumatic fracture EVs. The male and those aged 18-65 years are more susceptible to higher AT.

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.

Distal forearm squeeze test for the diagnosis of digital flexor tendon injuries.

BACKGROUND: The forearm/wrist squeeze/compression test has been used to examine digital flexor tendon injuries with varied names. Furthermore, the test has not been minutely described and its mechanism remains unclear. We renamed the test the "distal forearm squeeze test". The purpose of this study was to elaborate on the test and elucidate the mechanism. METHODS: Two patients with digital flexor tendons ruptured in zone 3 and zone 1 respectively and 50 outpatients with intact digital tendons underwent the test. Then the test was performed on 3 chickens under 4 conditions. First, when the digital flexor and extensor tendons were all intact. Second, after the flexor tendons of the third toe were transected. Third, after the flexor tendons of all toes of the foot were transected. Finally, after the flexor and extensor tendons of all toes of the foot were transected. RESULTS: In the patient with digital flexor tendons ruptured in zone 3, the test showed that the injured digit was flexed slightly while the uninjured digits were flexed obviously. In the patient with digital flexor tendon ruptured in zone 1, after separate stabilization of the proximal interphalangeal (PIP) joints of the injured and uninjured fingers in extension, the test showed that the distal interphalangeal joint of the patient's injured finger had no response, while those of the uninjured fingers were flexed. All 50 subjects showed clenched or half-clenched hands in response to the test. The test showed that all toes were flexed when the digital tendons of the chicken were intact. All toes were flexed except the third toe after the flexor tendons of the third toe were transected. All toes were extended after all the digital flexor tendons were transected. All toes had no response after all the digital flexor and extensor tendons were transected. CONCLUSIONS: The distal forearm squeeze test is valuable in examining digital flexor tendon injuries. If only the flexor digitorum profundus tendon is examined, the PIP joint of the finger should be stabilized in extension during the test.

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.

Targeting macrophagic PIM-1 alleviates osteoarthritis by inhibiting NLRP3 inflammasome activation via suppressing mitochondrial ROS/Cl- efflux signaling pathway.

BACKGROUND: Osteoarthritis (OA), in which macrophage-driven synovitis is considered closely related to cartilage destruction and could occur at any stage, is an inflammatory arthritis. However, there are no effective targets to cure the progression of OA. The NOD-, LRR-,and pyrin domain-containing protein 3 (NLRP3) inflammasome in synovial macrophages participates in the pathological inflammatory process and treatment strategies targeting it are considered to be an effective approach for OA. PIM-1 kinase, as a downstream effector of many cytokine signaling pathways, plays a pro-inflammatory role in inflammatory disease. METHODS: In this study, we evaluated the expression of the PIM-1 and the infiltration of synovial macrophages in the human OA synovium. The effects and mechanism of PIM-1 were investigated in mice and human macrophages stimulated by lipopolysaccharide (LPS) and different agonists such as nigericin, ATP, Monosodium urate (MSU), and Aluminum salt (Alum). The protective effects on chondrocytes were assessed by a modified co-culture system induced by macrophage condition medium (CM). The therapeutic effect in vivo was confirmed by the medial meniscus (DMM)-induced OA in mice. RESULTS: The expression of PIM-1 was increased in the human OA synovium which was accompanied by the infiltration of synovial macrophages. In vitro experiments, suppression of PIM-1 by SMI-4a, a specific inhibitor, rapidly inhibited the NLRP3 inflammasome activation in mice and human macrophages and gasdermin-D (GSDME)-mediated pyroptosis. Furthermore, PIM-1 inhibition specifically blocked the apoptosis-associated speck-like protein containing a CARD (ASC) oligomerization in the assembly stage. Mechanistically, PIM-1 inhibition alleviated the mitochondrial reactive oxygen species (ROS)/chloride intracellular channel proteins (CLICs)-dependent Cl- efflux signaling pathway, which eventually resulted in the blockade of the ASC oligomerization and NLRP3 inflammasome activation. Furthermore, PIM-1 suppression showed chondroprotective effects in the modified co-culture system. Finally, SMI-4a significantly suppressed the expression of PIM-1 in the synovium and reduced the synovitis scores and the Osteoarthritis Research Society International (OARSI) score in the DMM-induced OA model. CONCLUSIONS: Therefore, PIM-1 represented a new class of promising targets as a treatment of OA to target these mechanisms in macrophages and widened the road to therapeutic strategies for OA.

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.

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.

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.

Inhibition of NLRP3 inflammasome attenuates spinal cord injury-induced lung injury in mice.

Spinal cord injury (SCI) is one kind of severe traumatic injury, resulting in systemic inflammatory response syndrome and secondary lung injury, which is an important pathological basis of respiratory complications. The nucleotide-binding domain-like receptor protein 3 (NLRP3) inflammasome is an important cytosolic protein complex in many inflammatory diseases. Hence, it is inescapable to explore the effect of inhibition of NLRP3 inflammasome by inhibitors in a mouse SCI model, which was conducted by using the method of 30-G closing force aneurysm clipping at T6-T7 spinal segment for 1 min, followed by assessment of edema, histology, alveolar type II cell apoptosis, mitochondrial dysfunction, and neutrophil infiltration. In brief, our results showed that, NLRP3 inflammasome inhibitor BAY 11-7082 or A438079 inhibited activation of NLRP3 inflammasome, alleviated mitochondrial dysfunction, the number of macrophage and neutrophil, thereby attenuating alveolar type II cell apoptosis, lung edema, and histological injury. Taken together, our data reveal that NLRP3 inflammasome inhibitor BAY 11-7082 or A438079 attenuates the inflammatory response, reverses mitochondrial dysfunction, and subsequently alleviates secondary lung injury following SCI.

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.

Interleukin-34 Synovial Fluid Was Associated with Knee Osteoarthritis Severity: A Cross-Sectional Study in Knee Osteoarthritis Patients in Different Radiographic Stages.

BACKGROUND: Inflammation might play a crucial role in the pathogenesis of osteoarthritis (OA). Interleukin-34 (IL-34) is a well-known proinflammatory cytokine. OBJECTIVE: The objective of this study was to detect IL-34 levels in serum and synovial fluid (SF) of patients with OA and to investigate their correlation with radiographic and symptomatic severity. METHODS: One hundred and eighty-two OA patients and 69 controls were recruited. IL-34 levels were measured by enzyme-linked immunosorbent assay (ELISA). Radiographic and symptomatic severity of OA was reflected by Kellgren-Lawrence (KL) grades and Western Ontario McMaster University Osteoarthritis Index (WOMAC) scores, respectively. RESULTS: SF IL-34 levels were independently associated with the KL grade (B = 0.273, 95% CI: 0.150-0.395; P < 0.001). SF IL-34 levels were significantly correlated with WOMAC scores (r = 0.265, 95% CI: 0.123-0.399; P < 0.001). The correlation between SF IL-34 levels and WOMAC scores was still significant after adjusting for confounding factors (B = 0.020, 95% CI: 0.001-0.038; P = 0.035) in OA patients. CONCLUSIONS: We found that IL-34 levels in SF were significantly associated with the radiographic and symptomatic severity of knee OA.

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.

Mitochondria Targeted Peptide Attenuates Mitochondrial Dysfunction, Controls Inflammation and Protects Against Spinal Cord Injury-Induced Lung Injury.

BACKGROUND/AIMS: Spinal cord injury (SCI) is a common and devastating disease, which results in systemic inflammatory response syndrome and secondary lung injury. Mitochondrial dysfunction and inflammation are closely related to lung injury in diverse disease models. No studies have demonstrated the effects of mitochondrial targeted peptide SS-31 in a mouse model of SCI-induced lung injury. METHODS: Immediately after injury, mice in the treatment groups received a daily, single-dose intraperitoneal injection of SS-31 and for the next 2 days. The sham and SCI groups also received a daily single dose of vehicle (DMSO and 0.9% NaCl, 1: 3). The lung tissue of mice was examined after SCI, and tissue damage, apoptosis, inflammation, and mitochondrial dysfunction were recorded. RESULTS: SS-31 treatment attenuated lung edema and tissue damage. Furthermore, SS-31 treatment reduced apoptosis of alveolar type II cells, the number of total macrophages and M1 macrophages, and neutrophil infiltration. Moreover, SS-31 treatment attenuated reactive oxygen species levels, reversed mitochondrial dysfunction and inhibited NLRP3 inflammasome activation. CONCLUSIONS: Collectively, our results demonstrate that SS-31 attenuates mitochondrial dysfunction, controls inflammatory responses, and alleviates the severity of lung damage in a mouse model of SCI-induced lung injury.

Targeting the NLRP3 inflammasome to attenuate spinal cord injury in mice.

BACKGROUND: Spinal cord injury (SCI) is a devastating disease, which results in tissue loss and neurologic dysfunction. NLRP3 inflammasome plays an important role in the mechanism of diverse diseases. However, no studies have demonstrated the role of NLRP3 inflammasome and the effects of NLRP3 inflammasome inhibitors in a mouse model of SCI. We investigated whether inhibition of NLRP3 inflammasome activation by the pharmacologic inhibitor BAY 11-7082 or A438079 could exert neuroprotective effects in a mouse model of SCI. METHODS: SCI was performed using an aneurysm clip with a closing force of 30 g at the level of the T6-T7 vertebra for 1 min. Motor recovery was evaluated by an open-field test. Neuronal death was assessed by terminal deoxynucleotidyl transferase dUTP nick end labeling and Nissl staining. Mitochondrial dysfunction was determined by quantitative real-time polymerase chain reaction (qPCR), western blot, and detection of mitochondrial membrane potential level. Microglia/macrophage activation and astrocytic response were evaluated by immunofluorescence labeling. RESULTS: Inhibition of NLRP3 inflammasome activation by pharmacologic inhibitor BAY 11-7082 or A438079 reduced neuronal death, attenuated spinal cord anatomic damage, and promoted motor recovery. Furthermore, BAY 11-7082 or A438079 directly attenuated the levels of NLRP3 inflammasome and proinflammatory cytokines. Moreover, BAY 11-7082 or A438079 alleviated microglia/macrophage activation, neutrophils infiltration, and reactive gliosis, as well as mitochondrial dysfunction. CONCLUSIONS: Collectively, our results demonstrate that pharmacologic suppression of NLRP3 inflammasome activation controls neuroinflammation, attenuates mitochondrial dysfunction, alleviates the severity of spinal cord damage, and improves neurological recovery after SCI. These data strongly indicate that the NLRP3 inflammasome is a vital contributor to the secondary damage of SCI in mice.

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.