Association of modic changes and postoperative surgical site infection after posterior lumbar spinal fusion.

PURPOSE: Postoperative surgical site infection is one of the most serious complications following spine surgery. Previous studies have reported Modic changes (MC) represent a subclinical infection. This study aims to investigate the relation between Modic changes and surgical site infection after posterior lumbar fusion surgery. METHODS: We retrospectively reviewed the records of 424 patients who received posterior lumbar fusion. Preoperative clinical and radiological parameters were recorded. Primary outcome was the rate of postoperative surgical site infection. Covariates included age, body mass index (BMI), sex, hypertension, diabetes mellitus, chronic heart failure, Pfirrmann classification, fused levels, and operation duration. The presence of Modic changes was used as an exposition variable, and adjusted for other risk factors in multivariate analyses. RESULTS: Of the 424 patients, 30 (7%) developed an acute surgical site infection. Infection had no relation to age, sex, BMI, and comorbidities. There were 212 (50%) patients with MC, and 23 (10.8%) had a surgical site infection, compared to 212 (50%) patients without MC in which there were 7 (3.3%) surgical site infections. MC was associated with surgical site infection in univariate analysis (odds ratio [OR] = 3.56, 95% confidence interval [CI]: 1.49-8.50, p = 0.004) and multivariate logistic regression analysis (OR = 3.05, 95% CI: 1.26-7.37, p = 0.013). There was statistically significant between specific type (p = 0.035) and grade of MCs (p = 0.0187) and SSI. CONCLUSIONS: MCs may be a potential risk factor for SSI following posterior lumbar spinal intervertebral fusion. Type I and grade C MCs showed a higher infection rate compared with other MC types and grades.

Acetylshikonin promoting PI3K/Akt pathway and inhibiting SOX4 expression to delay intervertebral disc degeneration and low back pain.

This study investigated the molecular mechanism by which acetylshikonin inhibits SOX4 expression via the PI3K/Akt pathway to delay intervertebral disc degeneration (IVDD) and low back pain (LBP). Bulk RNA-seq, RT-qPCR, Western blot analysis, immunohistochemical staining, small interfering RNA (siSOX4), lentivirus (lentiv-SOX4hi ), and imaging techniques were used to assess SOX4 expression and validate its upstream regulatory pathway. Acetylshikonin and siSOX4 were injected into the IVD to measure IVDD. SOX4 expression significantly increased in degenerated IVD tissues. TNF-α increased SOX4 expression and apoptosis-related proteins in nucleus pulposus cells (NPCs). siSOX4 reduced TNF-α-induced NPCs apoptosis, while Lentiv-SOX4hi increased it. The PI3K/Akt pathway was significantly correlated with SOX4, and acetylshikonin upregulated PI3K/Akt pathway while inhibiting SOX4 expression. In the anterior puncture IVDD mouse model, SOX4 expression was upregulated, and acetylshikonin and siSOX4 delayed IVDD-induced LBP. Acetylshikonin delays IVDD-induced LBP by inhibiting SOX4 expression through the PI3K/Akt pathway. These findings offer potential therapeutic targets for future treatments.

Experimental and Simulation Study of the Fracture Instability Behavior in Polypropylene Fiber-Reinforced Concrete.

This study investigated the fracture characteristics of plain concrete and polypropylene fiber-reinforced concrete (PFRC) using pre-notched three-point bending beam tests with the digital speckle correlation method (DSCM). Then, the fracture instability behavior of the two types of beams was simulated in finite elements based on the plastic damage model and the cohesion model, for which the applicability was assessed. Furthermore, the stability of the Big Gang Mountain Dam made from plain concrete or PFRC subjected to the earth-quake loading was simulated with the plastic damage model. The results show that the limiting length of the non-local deformation zone can be used as an indicator of instability damage in a concrete structure. The simulation results of the plastic damage model agreed well with the local deformation in the pre-notched three-point bending beam test obtained from the DSCM. The plastic damage model was found to be capable of describing the residual strength phenomenon, which the cohesive model was not capable of. The damage evolution regions of the PFRC dam are strictly constrained in some regions without the occurrence of the local deformation band across the dam, and PFRC can dramatically reduce the failure risk under earthquake loading. The numerical solution proves that PFRC is an advisable material for avoiding failure in concrete dams.

Clinical atlas of rectal cancer highlights the barriers and insufficient interventions underlying the unfavorable outcomes in older patients.

Background: Aging confers an increased risk of developing cancer, and the global burden of cancer is cumulating as human longevity increases. Providing adequate care for old patients with rectal cancer is challenging and complex. Method: A total of 428 and 44,788 patients diagnosed with non-metastatic rectal cancer from a referral tertiary care center (SYSU cohort) and the Surveillance Epidemiology and End Results database (SEER cohort) were included. Patients were categorized into old (over 65 years) and young (aged 50-65 years) groups. An age-specific clinical atlas of rectal cancer was generated, including the demographic and clinicopathological features, molecular profiles, treatment strategies, and clinical outcomes. Results: Old and young patients were similar in clinicopathological risk factors and molecular features, including TNM stage, tumor location, tumor differentiation, tumor morphology, lymphovascular invasion, and perineural invasion. However, old patients had significantly worse nutritional status and more comorbidities than young patients. In addition, old age was independently associated with less systemic cancer treatment (adjusted odds ratio 0.294 [95% CI 0.184-0.463, P < 0.001]). We found that old patients had significantly worse overall survival (OS) outcomes in both SYSU (P < 0.001) and SEER (P < 0.001) cohorts. Moreover, the death and recurrence risk of old patients in the subgroup not receiving chemo/radiotherapy (P < 0.001 for OS, and P = 0.046 for time to recurrence [TTR]) reverted into no significant risk in the subgroup receiving chemo/radiotherapy. Conclusions: Although old patients had similar tumor features to young patients, they had unfavorable survival outcomes associated with insufficient cancer care from old age. Specific trials with comprehensive geriatric assessment for old patients are needed to identify the optimal treatment regimens and improve unmet cancer care. Study registration: The study was registered on the research registry with the identifier of researchregistry 7635.

Versatile FeMoOv nanozyme bipolar electrode electrochemiluminescence biosensing and imaging platform for detection of H2O2 and PSA.

In this work, a unique FeMoOv nanozyme-bipolar electrode (NM-BPE) electrochemiluminescence (ECL) biosensing and imaging platform was proposed for the first time to realize sensitive detection of target hydrogen peroxide (H2O2) and prostate specific antigen (PSA). Considering the advantage that the cathode and anode poles of the bipolar electrode (BPE) can be modified respectively, this work was carried out using anode equipped with ECL reagent bipyridine ruthenium (Ru(bpy)32+), and cathode equipped with the Fe-doped molybdenum oxide/Au nanoparticles (FeMoOv/AuNPs) with excellent peroxidase (POD) and catalase (CAT)-like activity. Because FeMoOv/AuNPs show efficient enzyme catalysis effect and can greatly promote the decomposition of H2O2, thus the electron transfer rate in the NM-BPE system would be much accelerated to enhance the ECL signal of Ru(bpy)32+. Based on this principle, this work not only realized sensitive detection of H2O2, but also ingeniously designed an sandwich immunosensor using FeMoOv/AuNPs as recognition probe to mediate the ECL response on the anode, achieving highly sensitive detection of PSA. Furthermore, a unique mobile phone ECL imaging system was developed for assay of PSA at different concentrations, which opened a new portable imaging sensing device for bioassays. This work was the first time to combine nanozymes with bipolar electrodes for ECL analysis and imaging, which not only broadened the applications of nanozymes, but also pioneered the new joint ECL research technique of bipolar electrode and ECL imaging in bioassays, showing great application prospect for multiple detection of proteins, nucleic acids and cancer cells.

Association between immediate postoperative hypoalbuminemia and surgical site infection after posterior lumbar fusion surgery.

PURPOSE: In this study, we intended to investigate the association between immediate postoperative hypoalbuminemia and surgical site infection (SSI), and determine a threshold value for postoperative hypoalbuminemia that can assist in risk stratification in patients after posterior lumbar fusion surgery. METHODS: From January 2017 to December 2021, 466 consecutive patients who underwent posterior lumbar fusion surgery were selected to analyze the relationship between immediate postoperative hypoalbuminemia and SSI. Multivariate logistic regression analysis was performed to identify the independent risk factors of SSI and postoperative hypoalbuminemia. Receiver Operating Characteristic (ROC) analysis was used to determine the optimal value for postoperative hypoalbuminemia, and subsequent grouping was based on the identified threshold. RESULTS: Of the total 466 patients, 25 patients (5.4%) developed SSI after surgery, and lower postoperative albumin (OR: 0.716, 95% CI: 0.611-0.840, p < 0.001) was independently associated with SSI. ROC analysis showed that the cutoff value of postoperative hypoalbuminemia was 32 g/L with a sensitivity of 0.760, specificity of 0.844, and a Youden index of 0.604. Postoperative SSI was more common in patients with postoperative hypoalbuminemia than in those without (21.6% vs. 1.6%, p < 0.001). Age, gender and operative duration were found to be independent predictors of postoperative hypoalbuminemia. CONCLUSIONS: This study showed that immediate postoperative hypoalbuminemia was an independent risk factor for the development of SSI in patients who underwent posterior lumbar fusion. Even in patients with a normal preoperative serum albumin level, there was an increased risk of SSI when the postoperative albumin within 24 h was < 32 g/L.

Contrast-Enhanced Ultrasound-Magnetic Resonance Imaging Radiomics Based Model for Predicting the Biochemical Recurrence of Prostate Cancer: A Feasibility Study.

Objective: This study was aimed at developing a model for predicting postoperative biochemical recurrence of prostate cancer (PCa) using clinical data-CEUS-MRI radiomics and at verifying its clinical effectiveness. Methods: The clinical imaging data of 159 patients pathologically confirmed with PCa and who underwent radical prostatectomy in Xiangyang No. 1 People's Hospital and Jiangsu Hospital of Chinese Medicine from March 2016 to December 2020 were retrospectively analyzed. According to the 2-5-year follow-up results, the patients were divided into the biochemical recurrence (BCR) group (n = 59) and the control group (n = 100). The training set and test set were established in the proportion of 7/3; 4 prediction models were established based on the clinical imaging data. In training set, the area under the curve (AUC) and decision curve analysis (DCA) by R was conducted to compare the efficiency of 4 prediction models, and then, external validation was performed using the test set. Finally, a nomogram tool for predicting BCR was developed. Results: Univariate regression analysis confirmed that the SmallAreaHighGrayLevelEmphasis, RunVariance, Contrast, tumor diameter, clinical T stage, lymph node metastasis, distant metastasis, Gleason score, preoperative PSA, treatment method, CEUS-peak intensity (PI), time to peak (TTP), arrival time (AT), and elastography grade were the influencing factors for predicting BCR. In the training set, the AUC of combinatorial model demonstrated the highest efficiency in predicting BCR [AUC: 0.914 (OR 0.0305, 95% CI: 0.854-0.974)] vs. the general clinical data model, the CEUS model, and the MRI radiomics model. The DCA confirmed the largest net benefits of the combinatorial model. The test set validation gave consistent results. The nomogram tool has been well applied clinically. Conclusion: The previous clinical and imaging data alone did not perform well for predicting BCR. Our combinatorial model firstly using clinical data-CEUS-MRI radiomics provided an opportunity for clinical screening of BCR and help improve its prognosis.

Integrated Bioinformatics Analysis and Verification of Gene Targets for Myocardial Ischemia-Reperfusion Injury.

Background: Myocardial ischemia-reperfusion injury (MIRI) has become a thorny and unsolved clinical problem. The pathological mechanisms of MIRI are intricate and unclear, so it is of great significance to explore potential hub genes and search for some natural products that exhibit potential therapeutic efficacy on MIRI via targeting the hub genes. Methods: First, the differential expression genes (DEGs) from GSE58486, GSE108940, and GSE115568 were screened and integrated via a robust rank aggregation algorithm. Then, the hub genes were identified and verified by the functional experiment of the MIRI mice. Finally, natural products with protective effects against MIRI were retrieved, and molecular docking simulations between hub genes and natural products were performed. Results: 230 integrated DEGs and 9 hub genes were identified. After verification, Emr1, Tyrobp, Itgb2, Fcgr2b, Cybb, and Fcer1g might be the most significant genes during MIRI. A total of 75 natural products were discovered. Most of them (especially araloside C, glycyrrhizic acid, ophiopogonin D, polyphyllin I, and punicalagin) showed good ability to bind the hub genes. Conclusions: Emr1, Tyrobp, Itgb2, Fcgr2b, Cybb, and Fcer1g might be critical in the pathological process of MIRI, and the natural products (araloside C, glycyrrhizic acid, ophiopogonin D, polyphyllin I, and punicalagin) targeting these hub genes exhibited potential therapeutic efficacy on MIRI. Our findings provided new insights to explore the mechanism and treatments for MIRI and revealed new therapeutic targets for natural products with protective properties against MIRI.

Grem1 accelerates nucleus pulposus cell apoptosis and intervertebral disc degeneration by inhibiting TGF-ß-mediated Smad2/3 phosphorylation.

Intervertebral disc degeneration (IVDD) is a main cause of low back pain, and inflammatory factors play key roles in its pathogenesis. Gremlin-1 (Grem1) was reported to induce an inflammatory response in other fields. This study aimed to investigate the mechanisms of Grem1 in the degenerative process of intervertebral discs. Dysregulated genes were determined by analyzing microarray profiles. The expression of Grem1 in 17 human disc samples (male:female = 9:8) and rat models (n = 5 each group) was measured by western blotting (WB), real-time quantitative PCR (RT-qPCR), and immunohistochemistry (IHC). The regulatory effects of Grem1 on apoptosis were examined using siRNAs, flow cytometry, immunofluorescence (IF), and WB. The therapeutic effect was evaluated by locally injecting specific Grem1 siRNA into IVDD rats. The expression of Grem1 was significantly increased in human degenerative intervertebral discs; furthermore, the expression of Grem1 positively correlated with the level of intervertebral disc degeneration. Grem1 was significantly overexpressed in tumor necrosis factor (TNF)-α-induced degenerative NP cells. Apoptosis in degenerative NP cells transfected with siRNA targeting Grem1 was significantly lower than that in the control group. Specific Grem1 siRNA markedly repressed the development of IVDD in surgery-induced IVDD rats. These results indicated that the expression of Grem1 was positively correlated with the severity of intervertebral disc degeneration, and Grem1 siRNA could inhibit Grem1-induced apoptosis and extracellular matrix alterations by mediating the TGF-ß/Smad signaling pathway. This study may provide a therapeutic strategy for alleviating inflammation-induced apoptosis associated with intervertebral disc degeneration.

Tenascin-C-mediated suppression of extracellular matrix adhesion force promotes entheseal new bone formation through activation of Hippo signalling in ankylosing spondylitis.

OBJECTIVES: The aim of this study was to identify the role of tenascin-C (TNC) in entheseal new bone formation and to explore the underlying molecular mechanism. METHODS: Ligament tissue samples were obtained from patients with ankylosing spondylitis (AS) during surgery. Collagen antibody-induced arthritis and DBA/1 models were established to observe entheseal new bone formation. TNC expression was determined by immunohistochemistry staining. Systemic inhibition or genetic ablation of TNC was performed in animal models. Mechanical properties of extracellular matrix (ECM) were measured by atomic force microscopy. Downstream pathway of TNC was analysed by RNA sequencing and confirmed with pharmacological modulation both in vitro and in vivo. Cellular source of TNC was analysed by single-cell RNA sequencing (scRNA-seq) and confirmed by immunofluorescence staining. RESULTS: TNC was aberrantly upregulated in ligament and entheseal tissues from patients with AS and animal models. TNC inhibition significantly suppressed entheseal new bone formation. Functional assays revealed that TNC promoted new bone formation by enhancing chondrogenic differentiation during endochondral ossification. Mechanistically, TNC suppressed the adhesion force of ECM, resulting in the activation of downstream Hippo/yes-associated protein signalling, which in turn increased the expression of chondrogenic genes. scRNA-seq and immunofluorescence staining further revealed that TNC was majorly secreted by fibroblast-specific protein-1 (FSP1)+fibroblasts in the entheseal inflammatory microenvironment. CONCLUSION: Inflammation-induced aberrant expression of TNC by FSP1+fibroblasts promotes entheseal new bone formation by suppressing ECM adhesion forces and activating Hippo signalling.

Perioperative Complications in 255 Patients Who Underwent Lateral Anterior Lumbar Interbody Fusion (LaLIF) Surgery.

PURPOSE: To investigate the perioperative complications of lateral anterior lumbar interbody fusion (LaLIF) surgery. METHODS: The participants were patients who underwent LaLIF surgery for degenerative lumbar diseases between April 2016 and November 2020. The collected data were classified into intraoperative and early-stage postoperative (1 month) complications. Intraoperative complications were subcategorized into nerve root injury, sympathetic chain injury, segmental artery injury, iliolumbar vein injury, peritoneum laceration, temporary psoas injury, endplate damage, and vertebral body fractures. Postoperative complications were subcategorized into surgical site infection, cage migration, cage subsidence and psoas major hematoma. RESULTS: In the 255 included patients, 39 complications (15.3%) were reported. One patient (0.4%) had residual neurological symptoms (numbness) at the last follow-up after conservative management. The most common complications were temporary psoas injury (3.9%), followed by sympathetic chain injury (2.7%) and endplate damage (2.0%). The most frequent postoperative complication was cage migration (1.6%), followed by cage subsidence (1.2%), and surgical site infection (0.8%). CONCLUSION: The complication rates for LaLIF are generally low and comparable to those for conventional OLIF and XLIF that have been reported in other studies. Almost all complications were transient after LaLIF. Severe complications can be avoided by using sufficient muscle relaxant, instruments with the required characteristics and vertical trajectories in multiple steps.

Visfatin promotes intervertebral disc degeneration by inducing IL-6 expression through the ERK/JNK/p38 signalling pathways.

Visfatin reportedly induces the expression of proinflammatory cytokines. Severe grades of intervertebral disc disease (IVDD) exhibit higher expression of visfatin than mild ones. However, the direct relationship between visfatin and IVDD remains to be elucidated. This study aimed to clarify whether stimulation of visfatin in IVDD is mediated by IL-6. To investigate the role of visfatin in IVDD, a rat model of anterior disc puncture was established by injecting visfatin or PBS using a 27-gauge needle. Results revealed an obvious aggravation of the histological morphology of IVDD in the visfatin group. On treating human NP cellswith visfatin, the levels of collagenII and aggrecan decreased and those of matrix metallopeptidase 3 and IL-6 gradually increased. A rapid increase in ERK, JNK, and p38 phosphorylation was also noted after visfatin treatment. Compared to those treated with visfatin alone, NP cells pretreated with ERK1/2, JNK, and p38 inhibitors or siRNA targeting p38, ERK, and JNK exhibited a significant suppression of IL-6. Our data represent the first evidence that visfatin promotes IL-6 expression in NP cells via the JNK/ERK/p38-MAPK signalling pathways. Further, our findings suggest epidural fat and visfatin as potential therapeutic targets for controlling IVDD-associated inflammation.

Comparison study of clinical outcomes and sagittal alignment improvement between anterior and posterior fusion techniques for multilevel cervical spondylotic myelopathy.

PURPOSE: To compare the sagittal alignment of different surgical approaches in patients with multiple levels cervical spondylotic myelopathy and explore the relationship between the cervical sagittal alignment and patient's health relative quality of life. METHOD: A total of 97 multiple levels cervical spondylotic myelopathy patients who underwent surgery from January 2013 to January 2019 were collected in this study. Patients were divided into three groups: anterior cervical discectomy with fusion, anterior cervical corpectomy with fusion and laminectomy with fusion groups. Clinical outcomes and sagittal alignment parameters were compared preoperative and postoperative. RESULTS: There were no significant differences in the average age and sex ratio among the groups. Sagittal parameters correlated to health relative quality of life were C7 slope, occipito-C2 angle, external auditory meatus tilt and cervical sagittal vertical axis. Both anterior cervical discectomy with fusion and anterior cervical corpectomy with fusion groups exhibited better sagittal alignment and clinical outcomes improvement postoperatively. Anterior cervical discectomy with fusion provided better clinical outcomes and the better improvement of cervical lordosis, C7 slope, occipito-C2 angle and cervical sagittal vertical axis compared with patients with Laminectomy with fusion. CONCLUSION: C7 slope, occipito-C2 angle, external auditory meatus tilt and cervical sagittal vertical axis are the most important cervical sagittal parameters correlated to clinical outcomes in patients with multilevels cervical spondylotic myelopathy; anterior cervical discectomy with fusion and anterior cervical corpectomy with fusion provides more efficient to restoration of cervical sagittal alignment.

Lateral-anterior lumbar interbody fusion (LaLIF) for lumbar degenerative disease: Technical notes, surgical system, and mid-term outcomes.

BACKGROUND: Many modified lateral lumbar interbody fusion techniques for lumbar degenerative diseases have been described by different authors. However, relatively high rates of vascular injury, peritoneal laceration, and even ureteral injury have been reported. PURPOSE: The objectives of this study were firstly to present the detailed, standardized technical notes and describe the required standard characteristics of the designed surgical system of LaLIF and secondly to evaluate clinical outcomes and highlight the approach-related complications. METHODS: The mini-open LaLIF is described in a step-wise manner. The outcome measures were operative parameters, self-report measures, radiographic measures, and complications within 1 month of surgery. Operative parameters measured included operative time, intraoperative blood loss, and length of hospital stay. The self-report measures include Visual Analogue Scale (VAS), Oswestry disability index (ODI), and Short Form 36 Health Survey (SF-36) score. The radiographic measures including the intervertebral foraminal height (FH), intervertebral disc height (DH), and intervertebral foraminal area (FA) were assessed with plain radiography. The complication profiles were classified into intraoperative and postoperative (up to 1 month). Intraoperative complications were subcategorized into neurologic, vascular, ureteral, peritoneal, and vertebral injuries. Postoperative complications were subcategorized into infection, cage migration, and subsidence. RESULTS: A total of 126 patients who underwent LaLIF between April 2016 and December 2018 â€‹by a senior author were retrospectively reviewed. There were 54 males and 72 females (range 42-89 â€‹years old, average 65 â€‹± â€‹11 years old). The mean follow-up was 20 â€‹± â€‹11 â€‹months (range 6-38 â€‹months). The LaLIF was conducted at 188 levels in 126 patients, with 1 level in 75 cases, 2 levels in 42, 3 levels in 7, and 4 levels in 2 cases. There were 114 patients who underwent stand-alone LaLIF and 12 patients required secondary posterior fixation. The mean operative time, intraoperative blood loss, and length of hospital stay were recorded. The patient-reported outcome scores (VAS, ODI, and SF-36) and radiographic parameters (FH, DH, and FA) demonstrated a significant improvement after surgery and at the last follow-up. There were 25 (19.8%) complications in the 126 patients. The intraoperative complications accounted for 19 cases (15.1%) and postoperative accounted for 6 cases (4.8%). The most frequent complications were neurological injury (6.3%) and temporary psoas injury (6.3%). CONCLUSIONS: The mini-open LaLIF, as a reproducible novel technique, can be performed safely at L2-L5. It is associated with reliable mid-term clinical outcomes and an acceptable complication profile when compared to traditional LLIF due to the advancements in the modified incision site, direct visualization, and usage of strictly vertical trajectory in multiple steps with the specially designed LaLIF system. TRANSLATIONAL POTENTIAL STATEMENT: To make the lateral lumbar fusion process repeatable and also maintain a shallow learning curve, especially for surgeons in the early stages of learning, by using instruments with the required standard characteristics, the standardized surgical steps, modified incision site, vertical trajectory, and the direct visualization during the entire procedure.

Growth differentiation factor-6 attenuates inflammatory and pain-related factors and degenerated disc-induced pain behaviors in rat model.

Previous studies have indicated that growth differentiation factor 6 (GDF6) is a potential candidate for intervertebral disc (IVD) degeneration (IDD) treatment. Here, we investigated the effect of GDF6 on IDD by examining changes in disc structure and the expression of inflammatory and pain-related factors. A rat posterior disc puncture model of single segments and three consecutive segments was constructed, and GDF6 or phosphate-buffered solution was administered via intradiscal injection 1 or 2 weeks after surgery. Magnetic resonance imaging showed a clear degeneration signal in the punctured disc, which was inhibited by GDF6. Histological staining revealed that GDF6 did not significantly improve the structure of IVDs in rats 8 weeks after puncture surgery, but it had an inhibitory effect on expression of the tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-1ß in the IVD. Furthermore, GDF6 was found to protect the morphology and structure of the IVD 32 weeks after surgery. Mechanical and thermal hyperalgesia tests suggested that GDF6 injection can significantly improve mechanical and thermal-stimulated pain behavior in rats and inhibit the expression of inflammatory factors TNF-α and IL-1ß and the pain factor calcitonin gene-related peptide in the dorsal root ganglion. A rat protein array test indicated that GDF6 could reduce the expression of cytokines IL-6, intercellular cell adhesion molecule-1, matrix metalloproteinase-13, IL-1ß, and TNF-α and increase the expression of tissue inhibitor of metalloproteinases 1, Transforming growth factor-beta 2, IL-10, and resistin in a TNF-α-induced IDD cell model. Thus, our study demonstrates that GDF6 can improve the structure of the IVD, inhibit the expression of inflammatory and pain-related factors, and improve pain behavior in rats. Clinical Significance: To establish further preclinical research and clinical trials, comprehensive data are needed to validate the regenerative properties of GDF6. Ideally, a regenerative agent should also be able to relieve discogenic pain, achieving the best clinical outcomes.

Wnt4 signaling mediates protective effects of melatonin on new bone formation in an inflammatory environment.

Growing evidence shows that the inhibitory effect of inflammatory cytokines on new bone formation by osteogenic precursor cells is a critical cause of net bone-density reduction. Melatonin has been proven to be a potential therapeutic candidate for osteoporosis. However, whether it is capable of antagonizing the suppressing effect of inflammatory cytokines on osteogenic precursor cells is so far elusive. In this study, using the cell culture system of human bone marrow stromal cells and MC3T3-E1 preosteoblasts, we recorded the following vital observations that provided insights of melatonin-induced bone formation: 1) melatonin induced bone formation in both normal and inflammatory conditions; 2) Wnt4 was essential for melatonin-induced bone formation in inflammatory stimulation; 3) melatonin- and Wnt4-induced bone formation occurred via activation of ß-catenin and p38-JNK MAPK pathways by interaction with a distinct frizzled LDL receptor-related protein complex; 4) melatonin suppressed the inhibitory effect of NF-κB on osteogenesis in a Wnt4-dependent manner; and 5) melatonin induced Wnt4 expression through the ERK1/2-Pax2-Egr1 pathway. In summary, we showed a novel mechanism of melatonin-induced bone formation in an inflammatory environment. Melatonin-induced Wnt4 expression is essential for its osteoinductive effect and the inhibitory effect of NF-κB on bone formation. Our novel findings may provide useful information for its potential translational application.-Li, X., Li, Z., Wang, J., Li, Z., Cui, H., Dai, G., Chen, S., Zhang, M., Zheng, Z., Zhan, Z., Liu, H. Wnt4 signaling mediates protective effects of melatonin on new bone formation in an inflammatory environment.

Paraoxonase 1 Was Negatively Associated With Intervertebral Disc Degeneration.

STUDY DESIGN: An in vivo and in vitro study of the correlation between Paraoxonase 1 (PON1) and intervertebral disc degeneration (IVDD). OBJECTIVE: The aim of this study is to clarify the expression and role of PON1 on the process of IVDD. SUMMARY OF BACKGROUND DATA: IVDD is responsible for most of the spinal degenerative diseases. Inflammation and oxidative stress can deteriorate the living environment of nucleus pulposus (NP) cells, leading to IVDD. PON1 is an enzyme reported to have anti-inflammatory and anti-oxidative effects. There is no study about the correlation of PON1 expression with IVDD. METHODS: Immunohistochemical (IHC), hematoxylin and eosin (H&E) staining, and Western blot examined the expression of PON1 in 88 human disc samples (male: female 43: 45) and rat models (n = 5 each group). The level of PON1 is measured in the tumor necrosis factor (TNF)-α and oxidative stress (H2O2)-induced degenerative NP cell models using Western blot and reverse transcription-polymerase chain reaction (RT-qPCR). The TNF-α, interleukin (IL)-1ß, Mito superoxide (SOX), aggrecan, and collagen II are detected in nucleus pulposus (NP) cells transfected with si-RNA of PON1 using Enzyme-Linked Immunosorbent Assay (ELISA), mitoSOX staining Western blot, and RT-qPCR. RESULTS: The expression of PON1 is significantly suppressed in human and rat degenerative intervertebral discs. The level of PON1 is significantly decreased in TNF-α and oxidative stress (H2O2)-induced degenerative NP cell models. ELISA results show that the level of TNF-α and IL-1ß obviously increased; Mito SOX staining indicates that the Mito SOX fluorescence significantly increased, and the expression of aggrecan and collagen reduced in NP cells transfected with si-RNA of PON1. CONCLUSION: Our study indicates that low PON1 expression is predictive of severe IVDD; PON1 plays an important role of keeping the homeostatic balance of intervertebral discs, and therapeutic approach regarding PON1 may be helpful to alleviate IVDD in the future. LEVEL OF EVIDENCE: N/A.

TNF-α enhances apoptosis by promoting chop expression in nucleus pulposus cells: role of the MAPK and NF-κB pathways.

CHOP has been shown to be involved in AF cells apoptosis and disc degeneration in a rat model. The aim of this study was to investigate the regulatory effects of TNF-α on C/EBP homologous protein (CHOP) and the role of CHOP in nucleus pulposus (NP) cell apoptosis. The effects of TNF-α on chop were measured by qPCR, Western blot, and immunofluorescence. TNF receptor involvement was analyzed by small interfering RNA (siRNA), Western blotting, immunofluorescence, and qPCR. The effects of NF-κB and MAPK on TNF-α-mediated chop promoter activity were studied using siRNAs, Western blotting, immunofluorescence, and qPCR. The regulatory effects of TNF-α-induced CHOP on Bcl-2 and Bax were studied using siRNAs, Western blotting, immunofluorescence, and qPCR. Flow cytometric and TUNEL analyses were performed to investigate the effects of chop on NP cell apoptosis. Increased CHOP expression was observed in NP cells after TNF-α treatment. Treatment of cells with TNF receptor, NF-κB, and ERK/JNK-MAPK inhibitors or siRNAs abolished the effects of cytokines on CHOP expression. Pharmacological siRNA knockdown of chop promoted Bax, decreased Bcl-2, and attenuated TNF-α-mediated cell apoptosis. During intervertebral disc degeneration (IVDD), TNF-α binds to TNF receptors and controls the JNK/ERK-MAPK, and NF-κB signaling pathways in NP cells, increasing CHOP expression. This change up-regulates the pro-apoptotic protein Bax and down-regulates the anti-apoptosis protein Bcl-2, inducing cell apoptosis. This study suggests a potential therapeutic target for controlling the inflammatory-induced apoptosis associated with IVDD. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Risk Factors Associated with Pain Severity in Patients with Non-specific Low Back Pain in Southern China.

STUDY DESIGN: A prospective cross-sectional study. PURPOSE: To evaluate the risk factors associated with the severity of pain intensity in patients with non-specific low back pain (NSLBP) in Southern China. OVERVIEW OF LITERATURE: Low back pain (LBP) is the leading cause of activity limitation and work absence throughout the world, so a firm understanding of the risk factor associated with NSLBP can provide early and prompt interventions that are aimed at attaining long-term results. METHODS: Participants were recruited from January 2014 to January 2016 and were surveyed using a self-designed questionnaire. Anonymous assessments included Short Form 36-Item Health Survey (SF-36) and Visual Analogue Scale (VAS). The association between the severity of NSLBP and these potential risk factors were evaluated. RESULTS: A total of 1,046 NSLBP patients were enrolled. The patients with primary school education, high body mass index (BMI), those exposed to sustained durations of driving and sitting, smoking, recurrent LBP had increased VAS and Oswestry Disability Index (ODI) scores with lower SF-36 scores (p <0.01). Workers and drivers compared with waiters and patients who lifted >10 kg objects in a quarter of their work time for >10 years had higher VAS and ODI scores with lower SF-36 scores (p <0.01). Multiple logistic regression showed lower levels of education, LBP for 1-7 days, long-lasting LBP in last year, smoking, long duration driving, and higher BMI were associated with more severe VAS score. CONCLUSIONS: The severity of NSLBP is associated with lower levels of education, poor standards of living, heavy physical labor, long duration driving, and sedentary lifestyle. Patients with recurrent NSLBP have more severe pain. Reducing rates of obesity, the duration of heavy physical work, driving or riding, and attenuating the prevalence of sedentary lifestyles and smoking may reduce the prevalence of NSLBP.

Circular RNA circ-4099 is induced by TNF-α and regulates ECM synthesis by blocking miR-616-5p inhibition of Sox9 in intervertebral disc degeneration.

Circular RNAs (circRNAs) play important roles in the initiation and development of different diseases. Here, we detected their role in intervertebral disc (IVD) degeneration. An Arraystar human circular RNA microarray assay was used to detect circRNAs in normal and degenerated human IVD nucleus pulposus (NP) tissues. The role of circ-4099 in IVDD and its mechanism were evaluated by qRT-PCR and gain-of-function/loss-of-function studies. Interaction networks for competing endogenous RNAs (ceRNAs), miRNAs, and miRNA target gene were detected by bioinformatics analysis, RNA immunoprecipitation and luciferase assay. Expression of seventy-two circRNAs were increased by more than twofold in degenerated NP tissues. qRT-PCR showed that the expression of circ-4099 in NP tissues was consistent with that of the array screening. Over-expression of circ-4099 increased the expression of Collagen II and Aggrecan and decreased the secretion of the pro-inflammatory factors IL-1ß, TNF-α, and PGE2. TNF-α treatment increased circ-4099 expression in NP cells. NF-κB/MAPK inhibitors or shRNAs abolished the inductive effects of TNF-α on circ-4099 expression. We further demonstrated that circ-4099 was able to function as a "sponge" by competitively binding miR-616-5p, which reversed the suppression of Sox9 by miR-616-5p. We used DNA pull-down and spectrometry experiments to show that TNF-α can promote circ-4099 transcription through upregulation of GRP78. We provide the first evidence that shows circRNAs are differentially expressed in degenerated and normal NP tissues. Circ-4099 may play a role in a protective mechanism and be part of a compensatory response that maintains the synthesis and secretion of the extracellular matrix in NP cells and might be a protective factor in IVD degeneration as well as restore NP cell function.