Inhibition of RhoA/MRTF-A signaling alleviates nucleus pulposus fibrosis induced by mechanical stress overload.

PURPOSE/AIM: : Intervertebral disc degeneration (IDD) is the leading cause of lower back pain, and clinically useful drugs for IDD are unavailable. Mechanical stress overload-induced fibrosis plays a critical role in IDD. RhoA/MRTF-A signaling is known to regulate tissue fibrosis; however, the effect of RhoA/MRTF-A on the development of IDD is unclear. MATERIALS AND METHODS: : The expression of aggrecan, collagen I, collagen II, MMP-12, CTGF, and MRTF-A in nucleus pulposus (NP) samples from IDD patients and controls was detected by immunohistochemical staining. Primary nucleus pulposus cells (NPCs) were isolated and cultured to establish an overload strain model treated with or without CCG-1423. The protein levels of RhoA, ROCK2, MRTF-A, CTGF, and MMP-12 as well as fibrosis-associated proteins were detected by western blotting and immunofluorescence. RESULTS: : Collagen I, MMP-12, and CTGF were significantly upregulated, and aggrecan and collagen II were significantly downregulated in the IDD samples. The cellular localization of MRTF-A was associated with intervertebral disc (IVD) degeneration. Overloaded strain enhanced the nuclear translocation of MRTF-A and changed the NPC morphology from spindle-shaped to long strips. Additional experiments showed that RhoA, ROCK2, MRTF-A, SRF, MMP-12, and CTGF were upregulated; however, aggrecan and collagen II were downregulated in NPCs under overload strain. CCG-1423, a RhoA/MRTF-A pathway inhibitor, reversed strain-induced fibrosis. CONCLUSION: : Mechanical stress activates RhoA/MRTF-A signaling to promote extracellular matrix (ECM) degeneration in the NP, which is associated with the development of IDD. Our findings suggest that the RhoA/MRTF-A inhibitor CCG-1423 can alleviate NPC degeneration caused by overload stress and has potential as a therapeutic agent for IDD.

Relationship between hinge fracture and postoperative axial symptoms after cervical laminoplasty.

OBJECTIVE: To identify the clinical characteristics of fractured hinges after open-door cervical laminoplasty for cervical canal stenosis and explore the relationship between hinge fractures and axial symptoms. METHODS: This was a retrospective study of patients with cervical myelopathy who underwent open-door laminoplasty between November 2014 and November 2016 at the Affiliated Hospital of Qingdao University. Cervical CT scans were performed after surgery and the Takeuchi criteria were applied to evaluate the postoperative axial symptoms. RESULTS: Of 223 opened laminae in 67 patients, 67 laminae (30.0%) in 30 patients (44.8%) showed fracture. The frequency of hinge fractures was higher at C6 (53.7%). Forty-nine fractured laminae (73.13%) were non-displaced and 18 were displaced. At 3 months, 33 fractured laminae (49.3%) showed bony union on CT, and union rates were 86.6% and 91.0% at 6 and 12 months, respectively, indicating that the union rate was lower for displaced fractures than for non-displaced fractures. Among the 67 patients, 14 had axial symptoms: three of 37 (8.1%) patients without hinge fractures and 11 of 30 (36.7%) patients with hinge fractures. One year later, the hinge fractures were healed in 24/30 patients. Among the six unhealed patients, five still suffered from axial symptoms. The frequency of axial symptoms was higher in the patients with three or more hinge fractures (66.7%) than in the patients with only one (16.7%) or two (46.7%) hinge fractures. CONCLUSIONS: Patients with hinge fractures may have an increased risk for axial symptoms after open-door cervical laminoplasty. The frequency of axial symptoms decreases with fracture healing.

A Bionic Thermosensitive Sustainable Delivery System for Reversing the Progression of Osteoarthritis by Remodeling the Joint Homeostasis.

Although the pathogenesis of osteoarthritis (OA) is unclear, inflammatory cytokines are related to its occurrence. However, few studies focused on the therapeutic strategies of regulating joint homeostasis by simultaneously remodeling the anti-inflammatory and immunomodulatory microenvironments. Fibroblast growth factor 18 (FGF18) is the only disease-modifying OA drug (DMOAD) with a potent ability and high efficiency in maintaining the phenotype of chondrocytes within cell culture models. However, its potential role in the immune microenvironment remains unknown. Besides, information on an optimal carrier, whose interface and chondral-biomimetic microenvironment mimic the native articular tissue, is still lacking, which substantially limits the clinical efficacy of FGF18. Herein, to simulate the cartilage matrix, chondroitin sulfate (ChS)-based nanoparticles (NPs) are integrated into poly(D, L-lactide)-poly(ethylene glycol)-poly(D, L-lactide) (PLEL) hydrogels to develop a bionic thermosensitive sustainable delivery system. Electrostatically self-assembled ChS and ε-poly-l-lysine (EPL) NPs are prepared for the bioencapsulation of FGF18. This bionic delivery system suppressed the inflammatory response in interleukin-1ß (IL-1ß)-mediated chondrocytes, promoted macrophage M2 polarization, and inhibited M1 polarization, thereby ameliorating cartilage degeneration and synovitis in OA. Thus, the ChS-based hydrogel system offers a potential strategy to regulate the chondrocyte-macrophage crosstalk, thus re-establishing the anti-inflammatory and immunomodulatory microenvironment for OA therapy.

Single-Component Dual-Functional Autoboost Strategy by Dual Photodynamic and Cyclooxygenase-2 Inhibition for Lung Cancer and Spinal Metastasis.

Coloading adjuvant drugs or biomacromolecules with photosensitizers into nanoparticles to enhance the efficiency of photodynamic therapy (PDT) is a common strategy. However, it is difficult to load positively charged photosensitizers and negatively charged adjuvants into the same nanomaterial and further regulate drug release simultaneously. Herein, a single-component dual-functional prodrug strategy is reported for tumor treatment specifically activated by tumor microenvironment (TME)-generated HOCl. A representative prodrug (DHU-CBA2) is constructed using indomethacin grafted with methylene blue (MB). DHU-CBA2 exhibited high sensitivity toward HOCl and achieved simultaneous release of dual drugs in vitro and in vivo. DHU-CBA2 shows effective antitumor activity against lung cancer and spinal metastases via PDT and cyclooxygenase-2 (COX-2) inhibition. Mechanistically, PDT induces immunogenic cell death but stimulates the gene encoding COX-2. Downstream prostaglandins E2 and Indoleamine 2,3 dioxygenase 1 (IDO1) mediate immune escape in the TME, which is rescued by the simultaneous release of indomethacin. DHU-CBA2 promotes infiltration and function of CD8+ T cells, thus inducing a robust antitumor immune response. This work provides an autoboost strategy for a single-component dual-functional prodrug activated by TME-specific HOCl, thereby achieving favorable tumor treatment via the synergistic therapy of PDT and a COX-2 inhibitor.

Precontoured Locking Compression Plate with Titanium Alloy Cable System: In Treatment of Neer Type IIb Distal Clavicle Fracture.

OBJECTIVE: To describe a new method which involves anatomical distal clavicle plate fixation and titanium alloy cable system-augmented coracoclavicular ligament reconstruction to manage Neer type IIb distal clavicle fracture. METHODS: Between January 2013 and June 2018, 28 patients with acute Neer type IIb lateral clavicle fracture were treated by a new method - precontoured locking compressive distal clavicular plate fixation of the fracture combined with titanium alloy cable system-augmented reconstruction of the coracoclavicular ligament. There were 11 females and 17 males treated in this way. There were 15 cases of the right side and 13 of the left. The mean age of the patients was 48.5 years (range, 18-78 years). The mean time from injury to surgery was 3.9 days (range, 1-7 days). After completing the preoperative examinations and evaluations, surgeries were performed for all these patients, anatomical distal clavicle plates were used for fractures, and titanium alloy cables were implanted for the augmented reconstruction of coracoclavicular ligaments. Postoperative protocols, including arm sling management and rehabilitative activities, were unified and recommended to all the patients. These patients were followed up for at least 1 year. The mean duration of postoperative follow-up was 23.3 months (range, 12-52 months). At the last follow-up, the coracoclavicular distances were recorded and shoulder functional outcomes were assessed by the Constant scores and the Fudan University Shoulder Scores (FUSSs) questionnaires. RESULTS: Radiographic bony unions were achieved in all patients within 20 weeks. Functional and radiographic outcomes were retrospectively evaluated. The mean coracoclavicular distance was 9.61 ± 0.61 mm on the injured side vs 9.62 ± 0.57 mm on the contralateral uninjured side. The mean Constant score and mean FUSS were 90.1 ± 6.6 (range, 68-98) and 86.1 ± 7.2 (range, 64-95) respectively, which indicating good restoration of function and high level of satisfaction for both the patients and their physical therapists. There were a few major complications, including one delayed healing of the skin, one severe shoulder stiffness, three incidences of moderate shoulder stiffness, and five incidences of symptomatic hardware. There is no deep infections, neurovascular injuried, delayed union or nonunion, peri-implant fracture, loss of reduction, implant malposition or failure, or other severe complications. CONCLUSION: This combined method for the treatment of Neer type IIb distal clavicle fracture could yield high bony union rate, good functional outcome, and low complication rate. Further prospective randomized controlled studies are needed to confirm the benefits of this method of treatment.

Development and Validation of Novel Nomograms for Predicting Specific Distant Metastatic Sites and Overall Survival of Patients With Soft Tissue Sarcoma.

PURPOSE: The goal of this study is to construct nomograms to effectively predict the distant metastatic sites and overall survival (OS) of soft tissue sarcoma (STS) patients. METHODS: STS case data between 2010 and 2015 for retrospective study were gathered from public databases. According to the chi-square and multivariate logistic regression analysis determined independent predictive factors of specific metastatic sites, the nomograms based on these factors were consturced. Subsequently, combined metastatic information a nomogram to predict 1-, 2-, and 3-year OS of STS patients was developed. The performance of models was validated by the area under the curve (AUC), calibration plots, and decision curve analyses (DCA). RESULTS: A total of 7001 STS patients were included in this retrospective study, including 4901 cases in the training group and the remaining 2,100 patients in the validation group. Three nomograms were established to predict lung, liver and bone metastasis, and satisfactory results have been obtained by internal and external validation. The AUCs for predicting lung, liver, and bone metastases in the training cohort were 0.796, 0.799, and 0.766, respectively, and in the validation cohort were 0.807, 0.787, and 0.775, respectively, which means that the nomograms have good discrimination. The calibration curves showed that the models have high precision, and the DCA manifested that the nomograms have great clinical application prospects. Through univariate and multivariate COX regression analyses, 8 independent prognosis factors of age, grade, histological type, tumor size, surgery, chemotherapy, radiatiotherapy and lung metastasis were determined. A nomogram was then constructed to predict the 1-, 2-, and 3-years OS, which has a good performance in both internal and external validations. CONCLUSION: The nomograms for predicting specific metastatic sites and OS have good discrimination, accuracy and clinical applicability. The models could accurately predict the metastatic risk and survival information, and help clinical decision-making.

Myocardin­related transcription factor A nuclear translocation contributes to mechanical overload­induced nucleus pulposus fibrosis in rats with intervertebral disc degeneration.

Previous studies have reported that the Ras homolog family member A (RhoA)/myocardin­related transcription factor A (MRTF­A) nuclear translocation axis positively regulates fibrogenesis induced by mechanical forces in various organ systems. The aim of the present study was to determine whether this signaling pathway was involved in the pathogenesis of nucleus pulposus (NP) fibrosis induced by mechanical overload during the progression of intervertebral disc degeneration (IVDD) and to confirm the alleviating effect of an MRTF­A inhibitor in the treatment of IVDD. NP cells (NPCs) were cultured on substrates of different stiffness (2.9 and 41.7 KPa), which mimicked normal and overloaded microenvironments, and were treated with an inhibitor of MRTF­A nuclear import, CCG­1423. In addition, bipedal rats were established by clipping the forelimbs of rats at 1 month and gradually elevating the feeding trough, and in order to establish a long­term overload­induced model of IVDD, and their intervertebral discs were injected with CCG­1423 in situ. Cell viability was determined by Cell Counting Kit­8 assay, and protein expression was determined by western blotting, immunofluorescence and immunohistochemical staining. The results demonstrated that the viability of NPCs was not affected by the application of force or the inhibitor. In NPCs cultured on stiff matrices, MRTF­A was mostly localized in the nucleus, and the expression levels of fibrotic proteins, including type I collagen, connective tissue growth factor and α­smooth muscle cell actin, were upregulated compared with those in NPCs cultured on soft matrices. The levels of these proteins were reduced by CCG­1423 treatment. In rats, 6 months of upright posture activated MRTF­A nuclear­cytoplasmic trafficking and fibrogenesis in the NP and induced IVDD; these effects were alleviated by CCG­1423 treatment. In conclusion, the results of the present study demonstrated that the RhoA/MRTF­A translocation pathway may promote mechanical overload­induced fibrogenic activity in NP tissue and partially elucidated the molecular mechanisms underlying the occurrence of IVDD.

Massively prolapsed intervertebral disc herniation with interlaminar endoscopic spine system Delta endoscope: A case series.

BACKGROUND: Surgery is often indicated for patients with massively prolapsed intervertebral disc herniation. The interlaminar endoscopic spine system (iLESSYS) Delta 6-mm working channel endoscope has advantages over other systems. The aim of this study was to explore the benefits and complications of using the iLESSYS Delta for the treatment of massively prolapsed intervertebral disc herniation. AIM: To explore the clinical benefits of treating massively prolapsed lumbar intervertebral disc herniation with the iLESSYS Delta endoscope. METHODS: In this study, the data of 37 patients who underwent surgery with the iLESSYS Delta endoscope at The Affiliated Hospital of Qingdao University were retrospectively analyzed. Intraoperative blood loss, operation time, and complications were collected. The visual analog scale (VAS), oswestry disability index (ODI), and modified MacNab criteria were determined before and at 1 d, 3 mo, and 6 mo after surgery. RESULTS: The mean intraoperative blood loss was 20.4 ± 1.2 mL. The mean operation time was 97.3 ± 12.4 min. The VAS scores for leg and back pain decreased from 68.0 ± 7.3, 34.4 ± 8.5 before operation to 2.5 ± 1.7, 5.5 ± 1.9 at 6 mo after surgery, respectively. The ODI also decreased from 60.2 ± 7.3 to 17.9 ± 3.4 at 6 mo after surgery. The improvement rate of the MacNab score was 86.4%, which was considered excellent. No spinal dural injury, nerve root injury, secondary protrusion of intervertebral disc, or myeloid hypertension was found during follow-up. CONCLUSION: The iLESSYS Delta 6-mm working channel endoscope has several advantages in terms of clinical and functional benefits, complications, and low risk of residual vertebral pulp in treating patients with massively prolapsed intervertebral disc herniation.

Piezo1 activates the NLRP3 inflammasome in nucleus pulposus cell-mediated by Ca2+/NF-κB pathway.

Studying and understanding the mechanism of inflammation in nucleus pulposus is the key to understand and prevent intervertebral disc degeneration. We propose a model of mechanical sensitive ion channel Piezo1 mediated inflammation of nucleus pulposus cells. Piezo1 can up-regulate the level of interleukin-1ß (IL-1ß) in nucleus pulposus cells once it is activated. It is suggested that Piezo1 may mediate inflammation by activating Nod-like receptor protein 3 (NLRP3) inflammasome to accelerate the production and maturation of IL-1ß. The primary objective of this study was to explore whether Piezo1 activates NLRP3 inflammasome in nucleus pulposus cells. Piezo1 sensitization was induced by mechanical stretch following which we analyzed the priming and assembly of NLRP3 inflammasome and also studied if the downstream Ca2+/NF-κB pathway mediated this activation in nucleus pulposus cells. The expression of Piezo1 and NLRP3 inflammasome increased in a time-dependent manner upon mechanical stretch. Piezo1 activation promoted NLRP3 inflammasome assembly, which was demonstrated by the upregulation of caspase-1 activation and IL-1ß production. Transfection of Piezo1-siRNA reversed this process. The inhibition of Ca2+/NF-κB pathway reduced Piezo1-dependent activation of NLRP3 inflammasome. Thus, we propose that activation of NLRP3 inflammasome in nucleus pulposus cells mediated by Piezo1 through the Ca2+/NF-κB pathway is a novel pathogenesis for the progress of intervertebral disc degeneration. As per our knowledge this is the first study which has provided evidence linking Piezo1-mediated inflammation in nucleus pulposus cells with the production of NLRP3 inflammasome.

Establishment and Validation of Novel Clinical Prognosis Nomograms for Luminal A Breast Cancer Patients with Bone Metastasis.

PURPOSE: Overall survival (OS) and cancer-specific survival (CSS) of luminal A breast cancer (BC) patients with bone metastasis remain poor and vary dramatically from person to person. Our goal was to build two universally applicable nomograms to accurately predict OS and CSS for luminal A patients with bone metastasis. METHODS: The data were collected from the Surveillance, Epidemiology, and End Results (SEER) database for luminal A BC patients with bone metastasis between 2010 and 2015. Univariate and multivariate Cox regression analyses were to assess and identify independent risk factors of OS and CSS. Integrating all significant predictors, nomograms and risk group stratification model was developed. The performance of the nomogram was validated with concordance index (C-index), calibration plots, and decision curve analyses (DCA) for discriminative ability, calibration, and clinical utility, respectively. RESULTS: 3171 luminal A BC patients with bone metastasis were included. Through univariate and multivariate Cox regression analyses, 12 variables were identified as both independent OS- and CSS-related factors, including age, race, primary site, histology grade, tumor size, surgery, brain metastasis, liver metastasis, lung metastasis, estrogen receptor status, progesterone receptor status, and insurance. Our nomograms for 1-, 3-, and 5-year survival were based on those significant prognostic factors to develop. The C-indexes of OS- and CSS-nomograms in the training cohort were 0.701 and 0.704, respectively. Similar results were obtained in the validation cohort. The calibration curves and DCA presented satisfactory calibration and clinical utility. CONCLUSION: Two nomograms have good discrimination, calibration, and clinical utility, can accurately and effectively predict the prognosis of patients, and may benefit for clinical decision-making. In high-risk patients, more aggressive therapy and closer surveillance should be considered.

12-Month Teriparatide Treatment Reduces New Vertebral Compression Fractures Incidence And Back Pain And Improves Quality Of Life After Percutaneous Kyphoplasty In Osteoporotic Women.

PURPOSE: Define the effectiveness of teriparatide (TPTD) treatment on reducing the incidence of new vertebral compression fractures (NVCFs) and back pain and improving quality of life after percutaneous kyphoplasty (PKP). METHODS: Two years of clinical follow-up data from primary osteoporotic women who had experienced initial osteoporotic vertebral compression fractures (OVCFs) and received PKP plus 12-month TPTD (n=113) or basic treatment (BT) of calcium and vitamin D supplements (n=208) were retrospectively collected. The risk of NVCFs over each 6-month period in the TPTD group was evaluated and compared with the BT group using a logistic regression. Health-related quality of life (HRQoL, EQ-5D questionnaire), back pain [100 mm visual analog scale (VAS)] and bone mineral density (BMD) of the spine were analyzed using linear mixed models for repeated measures (LMMRM). RESULTS: Logistic regression analysis adjusting for baseline characteristics showed that patients in the TPTD group had a lower risk of NVCFs compared with those receiving BT during the final three observation intervals (6-12 months, OR=0.189, 95% CI=0.030-0.681, p=0.046; 12-18 months, OR=0.009, 95% CI=0.0001-0.111, p=0.001; 18-24 months, OR=0.024, 95% CI=0.0009-0.264, p=0.009, respectively). Significant improvements in adjusted EQ-5D and back pain VAS scores were identified in the TPTD group compared with the BT group, and this improvement was sustained for at least 12 months after teriparatide treatment was discontinued (both p<0.001). The BMD of the spine also showed a higher T-value in the TPTD group compared with the BT group (p<0.001). CONCLUSION: In routine clinical practice, for patients with OVCFs who receive the PKP procedure, TPTD treatment may be a preferable subsequent therapy because of its ability to reduce the incidence of NVCFs and sustain a high quality of life and back pain alleviation.