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.

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.

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.

Percutaneous Endoscopic Transforaminal Lumbar Interbody Fusion: Technique Note and Comparison of Early Outcomes with Minimally Invasive Transforaminal Lumbar Interbody Fusion for Lumbar Spondylolisthesis.

PURPOSE: To compare the preliminary postoperative outcomes of percutaneous endoscopic transforaminal lumbar interbody fusion (Endo-TLIF) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in the treatment of lumbar spondylolisthesis. METHODS: Sixty-two patients with single-segment lumbar spondylolisthesis received Endo-TLIF and MIS-TLIF were enrolled in present study. Perioperative parameters, including operation time, estimated blood loss (EBL), interoperative fluoroscopy time, ambulation time and operative complications were recorded, respectively. The results of clinical metrics such as the Visual Analog Scale (VAS) for back and leg pain, the Oswestry Disability Index (ODI) and the Japanese Orthopaedic Association (JOA) score were obtained, respectively. Postoperative fusion rates were assessed by clinical fusion and CT at 12-month after surgery. RESULTS: No significant differences were found in the demographic data between the two groups. Compared with MIS-TLIF group, Endo-TLIF group had similar operative time, less intraoperative blood loss and shorter ambulation time but longer duration of X-ray radiation. The postoperative VAS scores of back pain, ODI and JOA score were significantly improved comparing with the preoperative scores in two groups, but the Endo-TLIF group showed more significant improvement in the early follow-up (P < 0.05, respectively). There were no significant differences in terms of the interbody fusion rate between the two groups. Meanwhile, no serious postoperative complications were observed in the study. CONCLUSION: Compared with MIS-TLIF, Endo-TLIF technique showed relatively faster recovery and better outcomes in terms of early curative effect, especially in 6 months after operation. However, intraoperative repeated fluoroscopy could result in highly cumulative radiation and longer operation time.

Predictive Risk Factors of Poor Preliminary Postoperative Outcome for Thoracic Ossification of the Ligamentum Flavum.

OBJECTIVE: The aim of the present study was to ascertain the independent risk factors of poor preliminary outcome and to reveal the value of these factors in predicting the postoperative prognosis. METHODS: A total of 165 patients diagnosed with thoracic myelopathy because of thoracic ossification of the ligamentum flavum (TOLF) were enrolled in this retrospective study. All of them underwent posterior decompressive laminectomy surgery in our hospital from May 2016 to June 2019. The postoperative improvement of symptoms was evaluated using the modified Japanese Orthopaedic Association (mJOA) scoring system. Clinical data, such as age, sex, body mass index (BMI), duration of symptoms, history of hypertension and diabetes, tobacco use, history of drinking, symptoms of incontinence, number of compressed segments, and preoperative mJOA score, were respectively recorded. Radiologic features data included sagittal maximum spinal cord compression (MSCC), axial spinal canal occupation ratio (SCOR), grades and extension of increased signal on sagittal T2-weighted images (ISST2I), types of increased signal on axial T2-weighted images (ISAT2I), and the classification of ossification on axial CT scan and sagittal MRI. The t-test, the χ2 -test, Fisher's exact test, binary logistic regression analyses, receiver operating characteristic (ROC) curves, and subgroup analyses were used to evaluate the effects of individual risk predictors on surgical outcomes. RESULTS: A total of 76 men and 89 women were enrolled in this study. The mean age of all patients was 58.53 years. After comparison between two groups, we found some risk factors that may be associated with postoperative outcomes, such as age, preoperative mJOA score, BMI, history of hypertension, MSCC, SCOR, grade and extension of ISST2I, type of ISAT2I, axial type of ossification, and sagittal type of ossification (P < 0.05, respectively). Binary logistic regression analysis revealed that older age (odds ratio [OR] = 1.062, 95% confidence interval [CI] = 1.006-1.121, P = 0.030), number of compressed segments (OR = 1.916, 95% CI = 1.250-2.937, P = 0.003), bilateral and bridged types of ossification (OR = 4 314, 95% CI = 1.454-8.657, P = 0.019; OR = 6.630, 95% CI = 2.580-17.530, P = 0.004), and grade 1 and 2 ISST2I (OR = 8.986, 95% CI =3.056-20.294, P < 0.001; OR = 7.552, 95% CI = 3.529-16.004, P < 0.001) were independent risk factors for a poor preliminary postoperative outcome. ROC curve analysis showed that the grade of ISST2I had an excellent discriminative power (area under the curve [AUC] = 0.817). In addition, risk factors have different values for predicting the clinical outcome in each subgroup. CONCLUSION: Age, duration of symptoms, number of compressed segments, SCOR, grade, and extension of ISST2I and classification of ossification were associated with the preliminary prognosis, and the intramedullary increased signal on sagittal T2-weighted MRI was highly predictive of poor postoperative outcome.

Percutaneous Full Endoscopic Management of Lumbar Posterior Edge Separation in Adolescents.

PURPOSE: Lumbar posterior edge separation is a common disorder with lumbar disc herniation (LDH) in adolescents. Over the years, there has been a lack of an acknowledged assessment and plan. The purpose of this study was to elucidate the feasibility of all sufferers who have received percutaneous full endoscopic treatment for lumbar posterior edge separation in adolescents. METHODS: Case series of sufferers with lumbar posterior edge separation who underwent surgery in the Affiliated Hospital Qingdao University between February 2017 and December 2018 were reviewed, including 15 males and 9 females. Preoperative and postoperative visual analogue scale (VAS) scores and the Korean Version of the Oswestry disability index (K-ODI) scores were used to evaluate the clinical outcomes. RESULTS: All sufferers were followed up for 6 to 12 months, with an average time of 10.7 months. The postoperative VAS scores of low back pain and leg pain and ODIs were significantly different from the preoperative scores (p < 0.05). According to the modified Mac Nab criteria, the results were excellent in 17 cases and good in 7 cases. CONCLUSIONS: Percutaneous full endoscopic treatment can effectively achieve neurological functional recovery in sufferers with favorable efficacy and safety.

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.