A Multi-Element Identification System Based on Deep Learning for the Visual Field of Percutaneous Endoscopic Spine Surgery.

Background: Lumbar disc herniation is a common degenerative lumbar disease with an increasing incidence. Percutaneous endoscopic lumbar discectomy can treat lumbar disc herniation safely and effectively with a minimally invasive procedure. However, the learning curve of this technology is steep, which means that initial learners are often not sufficiently proficient in endoscopic operations, which can easily lead to iatrogenic damage. At present, the application of computer deep learning technology to clinical diagnosis, treatment, and surgical navigation has achieved satisfactory results. Purpose: The objective of our team is to develop a multi-element identification system for the visual field of endoscopic spine surgery using deep learning algorithms and to evaluate the feasibility of this system. Method: We established an image database by collecting surgical videos of 48 patients diagnosed with lumbar disc herniation, which was labeled by two spinal surgeons. We selected 6000 images of the visual field of percutaneous endoscopic spine surgery (including various tissue structures and surgical instruments), divided into the training data, validation data, and test data according to 2:1:2. We developed convolutional neural network models based on instance segmentation-Solov2, CondInst, Mask R-CNN and Yolact, and set the four network model backbone as ResNet101 and ResNet50 respectively. Mean average precision (mAP) and frames per second (FPS) were used to measure the performance of each model for classification, localization and recognition in real time, and AP (average) is used to evaluate how easily an element is detected by neural networks based on computer deep learning. Result: Comprehensively comparing mAP and FSP of each model for bounding box test and segmentation task for the test set of images, we found that Solov2 (ResNet101) (mAP = 73.5%, FPS = 28.9), Mask R-CNN (ResNet101) (mAP = 72.8%, FPS = 28.5) models are the most stable, with higher precision and faster image processing speed. Combining the average precision of the elements in the bounding box test and segmentation tasks in each network, the AP(average) was highest for tool 3 (bbox-0.85, segm-0.89) and lowest for tool 5 (bbox-0.63, segm-0.72) in the instrumentation, whereas in the anatomical tissue elements, the fibrosus annulus (bbox-0.68, segm-0.69) and ligamentum flavum (bbox-0.65, segm-0.62) had higher AP(average),while extra-dural fat (bbox-0.42, segm-0.44) was lowest. Conclusion: Our team has developed a multi-element identification system for the visual field of percutaneous endoscopic spine surgery adapted to the interlaminar and foraminal approaches, which can identify and track anatomical tissue (nerve, ligamentum flavum, nucleus pulposus, etc.) and surgical instruments (endoscopic forceps, an high-speed diamond burr, etc.), which can be used in the future as a virtual educational tool or applied to the intraoperative real-time assistance system for spinal endoscopic operation.

Postoperative MRI Findings Following PELD and Their Correlations with Clinical Prognosis are Investigated by Injecting Contrast into Annulus Fibrosus Intraoperatively.

Objective: To validate whether a residual mass demonstrated on early postoperative MR after percutaneous endoscopic lumbar discectomy (PELD) is indeed an intraoperatively retained annulus fibrosus, and explore the correlation between imaging changes in the residual mass and clinical prognosis of patients. Methods: A prospective study of 118 patients were included. During surgery, a contrast medium, Gadopentetate Dimeglumine, was injected around the ruptured annulus fibrosus. The intensity of the T2 signal, the size of the remaining mass (SR), and the cross-sectional area of the spinal canal (SCSA), VAS, and ODI were assessed at preoperative, 1-h (7-day), 6-month, and 12-month postoperative intervals. Based on VAS at 7 days post-surgery, patients were classified into either a non-remission group (Group A, VAS > 3) or a remission group (Group B, VAS ≤ 3). Results: Six patients who developed recurrent LDH were excluded. A residual mass was detected on MRI 1 h after surgery in 94.6% (106/112). During one year of follow-up, 90.1% (101/112) of the patients displayed fibrous annulus remodeling, although 68.7% (77/112) still exhibited herniation. Significant differences were found in the ODI between Groups A and B one week after surgery (p < 0.001). However, no significant differences were observed in T2 signal intensity, SR, and SCSA at 1-h, 6-month and 12-month post-surgery (p > 0.05) between the two groups. In a multiple linear regression analysis, early postoperative ODI changes were associated with T2 signal (B = -10.22, sig < 0.05), long-term changes were associated with alterations in SR (B = 5.63, sig < 0.05) and SCSA (B = -0.13, sig < 0.05). Conclusion: The residual mass observed in early postoperative MR images after PELD was the retained annulus fibrosus intraoperatively. Short-term changes in clinical symptoms after PELD were linked to T2 signal intensity, while long-term changes were associated with changes in SR and SCSA.

CCL12 induces trabecular bone loss by stimulating RANKL production in BMSCs during acute lung injury.

In the last three years, the capacity of health care systems and the public health policies of governments worldwide were challenged by the spread of SARS-CoV-2. Mortality due to SARS-CoV-2 mainly resulted from the development of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). Moreover, millions of people who survived ALI/ARDS in SARS-CoV-2 infection suffer from multiple lung inflammation-induced complications that lead to disability and even death. The lung-bone axis refers to the relationship between lung inflammatory diseases (COPD, asthma, and cystic fibrosis) and bone diseases, including osteopenia/osteoporosis. Compared to chronic lung diseases, the influence of ALI on the skeleton has not been investigated until now. Therefore, we investigated the effect of ALI on bone phenotypes in mice to elucidate the underlying mechanisms. In vivo bone resorption enhancement and trabecular bone loss were observed in LPS-induced ALI mice. Moreover, chemokine (C-C motif) ligand 12 (CCL12) accumulated in the serum and bone marrow. In vivo global ablation of CCL12 or conditional ablation of CCR2 in bone marrow stromal cells (BMSCs) inhibited bone resorption and abrogated trabecular bone loss in ALI mice. Furthermore, we provided evidence that CCL12 promoted bone resorption by stimulating RANKL production in BMSCs, and the CCR2/Jak2/STAT4 axis played an essential role in this process. Our study provides information regarding the pathogenesis of ALI and lays the groundwork for future research to identify new targets to treat lung inflammation-induced bone loss.

Radiographic patterns and characteristics of sagittal profiles in normal spinopelvic curvatures: An explicit depiction of the distribution of lumbar vertebral bodies and discs.

The current study aimed to investigate the sagittal morphology of the spinopelvic complex and the components of the lumbar spine in the normal population. In total, 132 adult volunteers were retrospectively evaluated and divided into four groups according to the Roussouly classification. Statistical analysis of radiological parameters, including lumbar lordosis (LL), thoracic kyphosis (TK), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), PI-LL, LL-TK, lumbar vertebral lordosis from L1 to L5 (L1L-L5L), the intervertebral angle from L1-L2 to L5-S1 (IVA1-2-IVA5-1), segmental lordosis from L1 to L5 (S1L-S5L), the proportion of L1-L5 (L1%-L5%), the proportion of the intervertebral angle from L1-L2 to L5-S1 (IVA1-2%-IVA5-1%), and proportion of segmental lordosis from L1 to L5 (S1L%-S5L%), was performed. Based on the classification, type II (n = 46) was the most common, followed by type I (n = 39), type III (n = 36), and type IV (n = 11). The quantitative values of the sagittal parameters of the four groups were obtained. Results showed a significant difference in terms of LL, PI, SS, and LL-TK. Further, L1%, L2%, L3%, IVA1-2%, IVA2-3%, S1L%, S2L%, and S3L% had an increasing trend. PI was positively correlated with LL, S1L, S2L, S3L, S4L, S1L%, and S2L%, but not with S5L%. In conclusion, pelvic parameters had a significant effect on lumbar curvature and lordosis distribution. Further, the abovementioned results were beneficial for individual surgical decision-making regarding targeted intervertebral angle, screw-insertion dimension, and rod contouring.

CCL3 in the bone marrow microenvironment causes bone loss and bone marrow adiposity in aged mice.

The central physiological role of the bone marrow renders bone marrow stromal cells (BMSCs) particularly sensitive to aging. With bone aging, BMSCs acquire a differentiation potential bias in favor of adipogenesis over osteogenesis, and the underlying molecular mechanisms remain unclear. Herein, we investigated the factors underlying age-related changes in the bone marrow and their roles in BMSCs' differentiation. Antibody array revealed that CC chemokine ligand 3 (CCL3) accumulation occurred in the serum of naturally aged mice along with bone aging phenotypes, including bone loss, bone marrow adiposity, and imbalanced BMSC differentiation. In vivo Ccl3 deletion could rescue these phenotypes in aged mice. CCL3 improved the adipogenic differentiation potential of BMSCs, with a positive feedback loop between CCL3 and C/EBPα. CCL3 activated C/EBPα expression via STAT3, while C/EBPα activated CCL3 expression through direct promoter binding, facilitated by DNA hypomethylation. Moreover, CCL3 inhibited BMSCs' osteogenic differentiation potential by blocking ß-catenin activity mediated by ERK-activated Dickkopf-related protein 1 upregulation. Blocking CCL3 in vivo via neutralizing antibodies ameliorated trabecular bone loss and bone marrow adiposity in aged mice. This study provides insights regarding age-related bone loss and bone marrow adiposity pathogenesis and lays a foundation for the identification of new targets for senile osteoporosis treatment.

Percutaneous endoscopic lumbar discectomy via the medial foraminal and interlaminar approaches: A comparative study with 2-year follow-up.

Objective: The purpose of this study was to analyze the clinical effect of percutaneous endoscopic medial foraminal discectomy (PEMFD) in the treatment of lumbar disc herniation (LDH). Methods: We retrospectively examined and compared clinical data from 39 single-level LDH patients who underwent PEID and 47 who underwent PEMFD. All the patients were diagnosed with single-level LDH and were treated in Xuzhou Central Hospital for single-segmental lumbar disc herniation between June 2017 and December 2019. Collect and count surgical-related indicators, intraoperative bleeding volume and 24-hour postoperative drainage volume, lower extremity numbness Visual Analogue Scale (VAS), the pain VAS and lumbar Oswestry Disability Index (ODI) scores. Results: Intraoperative bleeding volume and 24-hour postoperative drainage volume were significantly lower in the PEMFD group (p < 0.05). Operation time and length of hospital stay did not significantly differ between the groups. Transient spinal cord injury and surgical site infection did not occur. Recurrence occurred in two patients in each group. Repeat surgery in these patients demonstrated remarkable epidural scarring in the PEID group patients; no scarring was evident in the PEMFD group patients. The numbness VAS score 72 h after surgery and the pain VAS and ODI scores 1 month after surgery significantly differed between groups; however, pain VAS and ODI scores 6, 12, and 24 months after surgery did not. At last follow-up, the modified MacNab criteria outcome did not significantly differ between the groups. Conclusion: PEMFD and PEID have similar short- and medium-term outcomes. However, PEMFD has several advantages: simplicity, lower bleeding volume, and preservation of the LF.

A retrospective study of the mid-term efficacy of full-endoscopic annulus fibrosus suture following lumbar discectomy.

Aims: Full-endoscopic discectomy is associated with a high risk of disc reherniation due to the poor mechanical strength of the annulus fibrosus after scar healing. It is technically difficult to place a full-endoscopic annulus fibrosus suture. We designed an annulus fibrosus suture device that can be used to suture annulus defects under microendoscopy. The present study investigated the safety and feasibility of this technology. Patients and Methods: We retrospectively analyzed the outcomes of patients who underwent surgical treatment for lumbar disc herniation (LDH) from January 2018 to October 2020. We compared 40 patients with LDH treated with full-endoscopic annulus fibrosus suture following lumbar discectomy (LD + AFS group) with 42 patients treated with lumbar discectomy alone (LD group) regarding demographic data, symptoms, and recurrence and reoperation rates. Lumbar MRI and CT were performed 3 and 12 months. A 10-point visual analog scale (VAS) and the Oswestry Disability Index (ODI) was used to evaluate pain and the lumbar spine function. Results: The cohort comprised 82 patients, including 40 patients in the LD + AFS group and 42 in the LD group. All operations were successfully completed without serious complications. Reherniation occurred in no patients in the LD + AFS group and three patients in the LD group. The VAS scores for lumbar and leg pain and ODI score were significantly improved postoperatively (p < 0.05). Conclusion: Compared with conventional lumbar discectomy, full-endoscopic annulus fibrosus suture following full-endoscopic lumbar discectomy is a safe and effective minimally invasive technique that reduces the LDH recurrence rate.

Diffuse Idiopathic Skeletal Hyperostosis Combined with Thoracic Spinal Stenosis Treated by Endoscopic Surgery: A Case Report.

CASE: A 48-year-old man presented to our facility with debilitating motor and sensory symptoms due to advanced T10-11 thoracic spinal stenosis secondary to diffuse idiopathic skeletal hyperostosis (DISH). The patient's condition was addressed with endoscopic spine surgery through a yet-to-be-reported interlaminar approach, and at the 12-month follow-up, his neurologic function was significantly improved. CONCLUSION: Select patients with symptomatic thoracic spinal stenosis secondary to DISH can be effectively managed with endoscopic spine surgery through an interlaminar approach by clinicians with extensive endoscopic spine experience.

HDAC6 inactivates Runx2 promoter to block osteogenesis of bone marrow stromal cells in age-related bone loss of mice.

BACKGROUND: Senile osteoporosis can cause bone fragility and increased risk for fractures and has been one of the most prevalent and severe diseases affecting the elderly population worldwidely. The underlying mechanisms are currently intensive areas of investigation. In age-related bone loss, decreased bone formation overweighs increased bone resorption. The molecular mechanisms underlying defective bone formation in age-related bone loss are not completely understood. In particular, the specific role of histone acetylation in age-related bone loss has not been examined thoroughly. METHODS: We employed 6- and 18-month-old mice to investigate the mechanisms of defective bone formation in age-related bone loss. Bone marrow stromal cells (BMSCs) were induced to undergo in vitro osteogenic differentiation. Chromatin immunoprecipitation (ChIP) was used to investigate the binding of histone deacetylases (HDACs) on Runx2 promoter in BMSCs. Luciferase reporter and transient transfection assay were employed to study Runx2 gene expression modulation by HDAC and androgen receptor (AR). siRNA and HDAC6 inhibitor, Tubastatin A, were used to inhibit HDAC6 in vitro. And systemic administration of Tubastatin A was used to block HDAC6 in vivo. RESULTS: Age-related trabecular bone loss was observed in 18-month-old mice compared with 6-month-old mice. In vitro osteogenic differentiation potential of BMSCs from 18-month-old mice was weaker than 6-month-old mice, in which there was Runx2 expression inactivation in BMSCs of 18-month-old mice compared with 6-month-old mice, which was attributable to HDAC6-mediated histone hypoacetylation in Runx2 promoter. There was competitive binding of HDAC6 and AR on Runx2 promoter to modulate Runx2 expression in BMSCs. More importantly, through siRNA- or specific inhibitor-mediated HDAC6 inhibition, we could activate Runx2 expression, rescue in vitro osteogenesis potential of BMSCs, and alleviate in vivo age-related bone loss of mice. CONCLUSION: HDAC6 accumulation and histone hypoacetylation on Runx2 promoter contributed to the attenuation of in vitro osteogenic differentiation potential of BMSCs from aged mice. Through HDAC6 inhibition, we could activate Runx2 expression and osteogenic differentiation potential of BMSCs from aged mice and alleviate the age-related bone loss of aged mice. Our study will benefit not only for understanding the age-related bone loss, but also for finding new therapies to treat senile osteoporosis.

Linear and Non-linear Correlations Between Serum Phosphate Level and Bone Mineral Density in Type 2 Diabetes.

Introduction: Serum phosphate plays an important role in bone mineralization and might be a risk factor for many bone diseases. Patients with T2D usually have low serum phosphate level due to diet control, osmotic diuresis, and insulin stimulation. Current studies have discussed the linear association between serum phosphate and bone mineral density (BMD). Objective: We aimed to analyze both the linear and non-linear correlations between serum phosphate and BMD in patients with type 2 diabetes (T2D). Methods: We included 1,469 patients with T2D and obtained their basic information, laboratory measurements, and BMD data. Multivariate adjusted linear regression was used to analyze the linear associations, and we applied a two-piecewise linear regression model using a smoothing function to examine the non-linear association. Results: No linear correlation was found between serum phosphate and BMD in patients with T2D. In women with T2D, we found a non-linear correlation between serum phosphate level and femur neck or total hip BMD. When serum phosphate was <1.3 mmol/L, it was positively associated with femur neck and total hip BMD, whereas when phosphate was >1.3 mmol/L, it was negatively associated with femur neck BMD. Conclusions: In men with T2D, serum phosphate level was not associated with BMD. However, in women with T2D, we found a non-linear correlation between serum phosphate and femur neck or total hip BMD.

Association between serum levels of bone turnover markers and bone mineral density in men and women with type 2 diabetes mellitus.

BACKGROUND: In patients with type 2 diabetes mellitus (T2DM), higher risks of impaired bone metabolism are widely reported. To evaluate bone metabolism, bone mineral density (BMD) and bone turnover levels should be included. In this article, we analyzed the relationship between them in T2DM. METHODS: We conducted a hospital-based cross-sectional study enrolling 1499 patients hospitalized for T2DM between October 2009 and January 2013. Multivariate linear regression models were used to identify the relationship between bone turnover markers (BTMs) and BMD levels. A two-sided P-value < .05 was considered statistically significant. RESULTS: After adjusting for confounding factors, osteocalcin (OC) showed a negative relationship with total lumbar, femur neck, and total hip BMD in men and women. N-terminal propeptides of type I collagen (P1NP) and alkaline phosphatase (ALP) showed a negative association with BMD at three sites in men and total lumbar BMD in women, whereas in the femur neck and total hip in women, the relationship was only found for P1NP with total hip. For ß-C-terminal telopeptides of type I collagen (ß-CTX), a negative relationship was also found in all three sites for BMD in men and total lumbar BMD in women, whereas ß-CTX was not associated in the femoral neck and total hip in women. CONCLUSION: In patients with T2DM, serum levels of OC, P1NP, ß-CTX, and ALP were negatively correlated with BMD levels in men in three sites and with total lumbar BMD in women. The relationship varied in femur neck and total hip BMD in women.

[Corrigendum] Inhibition of MDA-MB-231 breast cancer cell migration and invasion activity by andrographolide via suppression of nuclear factor-κB-dependent matrix metalloproteinase-9 expression.

Subsequent to the publication of the above article, the authors have realized that Fig. 2 in their paper contained an error. The image selected to represent the experiment showing the migration of cells in the presence of andrographolide (30 µM) was chosen incorrectly during the figure compilation process. A corrected version of Fig. 2 is presented here. Note that this change does not affect the results or the conclusions reported in this paper, and all the authors agree to this correction. The authors apologize to the Editor and to the readership of the Journal for any inconvenience caused. [the original article was published in the Molecular Medicine Reports 11: 1139­1145, 2015; DOI: 10.3892/mmr.2014.2872].

Association Between Bone Mineral Density, Bone Turnover Markers, and Serum Cholesterol Levels in Type 2 Diabetes.

Purpose: The association between bone mineral density (BMD), bone turnover markers, and serum cholesterol in healthy population has already been proved. However, in patients with type 2 diabetes mellitus (T2D), it has not been adequately analyzed. In this study, we investigated the correlation between BMD, bone turnover markers, and serum cholesterol levels in people with T2D. Methods: We enrolled 1,040 men and 735 women with T2D from Zhongshan Hospital between October 2009 and January 2013. Their general condition, history of diseases and medication, serum markers, and BMD data were collected. We used logistic regression analysis to identify the association between serum cholesterol levels and BMD as well as bone turnover markers. Results: In multivariate regression analysis, we observed that in men with T2D, high high-density lipoprotein-cholesterol and total cholesterol levels were significantly associated with low total lumbar, femur neck, and total hip BMD, while low-density lipoprotein-cholesterol level was only inversely associated with total lumbar and femur neck BMD. Total cholesterol and low-density lipoprotein-cholesterol levels were also negatively associated with osteocalcin, procollagen type I N-terminal propeptide, and ß-crosslaps. In women with T2D, high-density lipoprotein-cholesterol level was observed to be negatively correlated with total lumbar, femur neck, and total hip BMD, while total cholesterol and low-density lipoprotein-cholesterol levels were only associated with BMD at the total lumbar. Furthermore, total cholesterol was also negatively associated with osteocalcin, procollagen type I N-terminal propeptide, and ß-crosslaps; high-density lipoprotein-cholesterol was only related to osteocalcin and parathyroid hormone, while low-density lipoprotein-cholesterol was only related to ß-crosslaps in women. Conclusion: Our study suggests a significantly negative correlation between serum cholesterol levels and BMD in both men and women with T2D. The associations between serum cholesterol levels and bone turnover markers were also observed in T2D patients.

MiR-199a-3p inhibits proliferation and induces apoptosis in rheumatoid arthritis fibroblast-like synoviocytes via suppressing retinoblastoma 1.

Background Fibroblast-like synoviocytes (FLSs) that line the intimal synovium play a crucial role in the pathogenesis of rheumatoid arthritis (RA). miR-199a-3p is a highly conserved miRNA that has been shown to regulate a variety of growth behaviors in diverse cell types. However, the role of miR-199a-3p in RA-FLS is still unknown. Methods Here, we presented the first experimental evidence showing that miR-199a-3p was a critical regulator of RA-FLS function. Results miR-199a-3p expression was significantly reduced in RA-FLS compared with normal FLS. Ectopic expression of miR-199a-3p significantly inhibited RA-FLS proliferation and induced apoptosis, which was demonstrated by an increase in caspase-3 activity and Bax/Bcl-2 ratio. Our bioinformatics analysis identified Retinoblastoma 1 (RB1) gene to be a direct target of miR-199a-3p. In RA-FLS, miR-199a-3p directly targetted the 3'-UTR of RB1 mRNA and suppressed endogenous RB1 expression, whereas miR-199a-3p-resistant variant of RB1 was not affected. Silencing RB1 decreased cell proliferation and promoted apoptosis in RA-FLS, an effect comparable with miR-199a-3p overexpression. Enforced expression of RB1 partially restored cell proliferation and attenuated apoptosis in miR-199a-3p-overexpressing RA-FLSs. Conclusion In summary, miR-199a-3p is down-regulated in RA-FLS, and miR-199a-3p inhibits proliferation and induces apoptosis in RA-FLS, partially via targetting RB1. The miR-199a-3p/RB1 pathway may represent a new therapeutic target for RA.

Interleukin-6 from subchondral bone mesenchymal stem cells contributes to the pathological phenotypes of experimental osteoarthritis.

As a main cause of morbidity in the aged population, osteoarthritis (OA) is characterized by cartilage destruction, synovium inflammation, osteophytes, and subchondral bone sclerosis. To date its etiology remains elusive. Recent data highlight an important role of subchondral bone in the onset and progression of OA. Therefore, elucidating the mechanisms underlying abnormal subchondral bone could be of importance in the treatment of OA. Interleukin-6 is a proinflammatory cytokine involved in many physiological and pathological processes. Although in vitro and in vivo studies have indicated that IL-6 is an important cytokine in the physiopathogenesis of OA, its effects on subchondral bone have not been studied in OA animal models. In this study, we aimed to i) investigate the role of IL-6 in the pathological phenotypes of OA subchondral bone MSCs including increase in cell numbers, mineralization disorder and abnormal type I collagen production; ii) explore whether the systemic blockade of IL-6 signaling could alleviate the pathological phenotypes of experimental OA. We found that IL-6 was over-secreted by OA subchondral bone MSCs compared with normal MSCs and IL-6/STAT3 signaling was over-activated in subchondral bone MSCs, which contributed to the pathological phenotypes of OA subchondral bone MSCs. More importantly, systemic inhibition of IL-6/STAT3 signaling with IL-6 antibody or STAT3 inhibitor AG490 decreased the severity of pathological phenotypes of OA subchondral bone MSCs and cartilage lesions in OA. Our findings provide strong evidence for a pivotal role for IL-6 signaling in OA and open up new therapeutic perspectives.

Electrospun fibrous membranes featuring sustained release of ibuprofen reduce adhesion and improve neurological function following lumbar laminectomy.

Electrospun fibrous membranes provide suitable physical anti-adhesion barriers for reducing tissue anti-adhesion following surgery. However, often during the biodegradation process, these barriers trigger inflammation and cause a foreign body reaction with subsequent decrease in anti-adhesion efficacy. Here, a facile strategy comprising the incorporation of ibuprofen (IBU) into implantable membranes and its sustained release was proposed in order to improve anti-adhesion effects and neurological outcomes, namely to prevent failed back surgery syndrome (FBSS). The combination of free IBU and a newly synthetized polymeric prodrug of IBU, namely poly(hydroxyethyl methacrylate) with ester-linked IBU, was successfully used in order to reduce initial burst drug release and provide sustained drug release from fibrous membranes throughout several weeks. Such release profile was shown useful in preventing both acute and chronic inflammation in rats following laminectomy and membrane implantation. Moreover, histological analysis provided evidence of an excellent anti-adhesion effect, while associated neurological deficits were effectively reduced. Furthermore, the assessment of macrophage density, neovascularization, and related gene expression at the lesion site revealed that a sustained anti-inflammatory effect was achieved with the IBU-loaded proposed fibrous membranes. Results suggested that the COX2 pathway plays an important role in the development epidural fibrosis and arachnoiditis. Overall, this study provided evidence that precisely engineered IBU-loaded electrospun fibrous membranes may be useful in preventing FBSS and able to potentially impact the outcome of patients undergoing spine surgery.

Cartilage oligomeric matrix protein improves in vivo cartilage regeneration and compression modulus by enhancing matrix assembly and synthesis.

Cartilage oligomeric matrix protein (COMP), an abundant cartilage extracellular matrix protein, plays an important role in mesenchymal chondrogenesis. To test our hypothesis that COMP could promote tissue engineering cartilage regeneration as well as improve cartilaginous mechanical properties, COMP gene transfected rabbit bone marrow mesenchymal stem cells (BMSCs) were used for chondrogenic differentiation in vitro and were implanted with biphasic scaffolds into osteochondral defects of New Zealand white rabbit trochlear grooves for cartilage regeneration in vivo. In vitro, over expressed COMP could enhance the chondrogenic differentiation and ECM secretion of BMSCs. After euthanasia at 12 weeks post implantation, macroscopic observation, histological staining, mechanical tests and micro-CT were performed for the assessment of repaired cartilage. Overexpression of COMP leads to more newly formed hyaline cartilage and significantly improved mechanical property. These results demonstrated the significant role of COMP in the cartilage regeneration in vivo and offered inspiring advantage of COMP in the application of tissue engineering.

Pilose antler peptide potentiates osteoblast differentiation and inhibits osteoclastogenesis via manipulating the NF-κB pathway.

Bones are inflexible yet ever-changing metabolic organs, and bone homeostasis is maintained through two delicately regulated processes: bone construction and bone reabsorption. An imbalance in bone metabolism is linked to most orthopedic diseases, including osteoporosis and rheumatoid arthritis. Importantly, tumor necrosis factor-α (TNF-α) blocks osteoblast differentiation and stimulates osteoclast formation, resulting in delayed deposition of new bone and accelerated bone resorption, especially in rheumatoid arthritis patients with inflammatory conditions. Pilose antler peptide (PAP) isolated and purified from deer antlers has been shown to have beneficial effects on chronic inflammation. In the present study, we studied the impact of PAP on osteoblast differentiation and evaluated the regulatory mechanism, with particular emphasis on the effect of PAP on TNF-α-mediated NF-κB signaling. Mouse primary osteoblast cells were activated with bone morphogenetic protein-2 (BMP-2) for osteoblast differentiation. A significant stimulatory effect of PAP in osteoblastogenesis was observed using ALP activity and Alizarin Red S staining assays. Meanwhile, PAP significantly rescued TNF-α-induced impairment of osteoblast formation as well as mineralization. Furthermore, we found a similar trend upon analyzing osteoblast-specific gene expression. PAP significantly rescued TNF-α-mediated decrease in expression of osteoblast-specific genes. A molecular mechanism assay indicated that PAP significantly inhibited TNF-α-mediated stimulation of NF-κB signaling activity, as well as nuclear translocation of its subunit p65. Moreover, over-expression of p65 reversed the stimulatory effects of PAP on osteoblast differentiation. Furthermore, we also identified that PAP dose dependently inhibit osteoclastogenesis, and this effect might be achieved via suppressing NF-κB activity. In summary, this study shows that PAP promotes osteoblast differentiation and blocks TNF-α-mediated suppression of osteoblastogenesis in vitro via the NF-κB/p65 pathway, as well as inhibits osteoclastsogenesis in vitro. Therefore, PAP, a novel drug with both antiresorptive and osteoanabolic activity, shows therapeutic potential as an alternative treatment for osteolytic diseases, including rheumatoid arthritis and osteoporosis.

Transforming growth factor ß and its role in heart disease.

Myocardial infarction (MI) is a major form of heart disease that leads to immediate cardiomyocyte death due to ischemia and eventually fibrosis and scar formation and further dysfunction of myocardium and heart failure. Extracellular matrix (ECM) production and tissue repair is conducted by myofibroblasts, which are formed from the normal quiescent cardiac fibroblasts following transformational changes, through the active participation of transforming growth factor ß (TGFß) and its signaling pathways. TGFß appears to be a 'Master of all trades', with respect to cardiac fibrosis, as it can promote cardiomyocyte apoptosis and cardiac hypertrophy. TGFß signaling involves its binding to TGFß receptor type II (TGFßRII), which recruits TGFß receptor type I (TGFßRI), which are also known as activin receptor-like kinase (ALK) in five different isoforms. In canonical signaling pathways, ALK5 activates Smads 2 and 3, and ALK1 activates Smads 1 and 5. These pairs of Smads form a corresponding complex and then bind to Smad 4, to translocate into the nucleus, where transcriptional reprogramming is carried out to promote myofibroblast formation and ECM production, eventually leading to cardiac fibrosis. TGFß levels are elevated in MI, thereby aggravating the myocardial injury further. Several microRNAs are involved in the regulation of TGFß signaling at different steps, affecting different components. Therapeutic targeting of TGFß signaling at ALK1-5 receptor activity level has met with limited success and extensive research is needed to develop therapies based on the components of TGFß signaling pathway, for instance cardiac dysfunction and heart failure.