Overexpression of EGFL7 promotes angiogenesis and nerve regeneration in peripheral nerve injury.

Peripheral nerve injury (PNI) often leads to significant functional impairment. Here, we investigated the impact of epidermal growth factor-like domain-containing protein 7 (EGFL7) on angiogenesis and nerve regeneration following PNI. Using a sciatic nerve injury model, we assessed nerve function using the sciatic nerve function index. We analyzed the expression levels of EGFL7, forkhead box proteins A1 (FOXA1), nerve growth factor (NGF), brain-derived neurotrophic factors (BDNF), Neurofilament 200 (NF200), myelin protein zero (P0), cell adhesion molecule 1 (CD31), vascular endothelial growth factor (VEGF), and NOTCH-related proteins in tissues and cells. Cell proliferation, migration, and angiogenesis were evaluated through cell counting kit assays, 5-ethynyl-2'deoxyuridine staining, and Transwell assays. We investigated the binding of FOXA1 to the EGFL7 promoter using dual-luciferase assays and chromatin immunoprecipitation. We observed decreased EGFL7 expression and increased FOXA1 expression in PNI, and EGFL7 overexpression alleviated gastrocnemius muscle atrophy, increased muscle weight, and improved motor function. Additionally, EGFL7 overexpression enhanced Schwann cell and endothelial cell proliferation and migration, promoted tube formation, and upregulated NGF, BDNF, NF200, P0, CD31, and VEGF expression. FOXA1 was found to bind to the EGFL7 promoter region, inhibiting EGFL7 expression and activating the NOTCH signaling pathway. Notably, FOXA1 overexpression counteracted the effects of EGFL7 on Schwann cells and endothelial cells. In conclusion, EGFL7 holds promise as a therapeutic molecule for treating sciatic nerve injury.

Tetramethylpyrazine promotes angiogenesis and nerve regeneration and nerve defect repair in rats with spinal cord injury.

Objective: This study evaluated the regulatory effect of Tetramethylpyrazine (TMP) on the spinal cord injury (SCI) rat model and clarified the neuroprotective mechanism of TMP on SCI. Methods: An SCI rat model was generated and treated with TMP injections for two weeks. miR-497-5p and EGFL7 expression changes were evaluated, motor function recovery after SCI was assessed by BBB score test and footprint analysis, lesions of rat spinal cord were assessed by HE staining and TUNEL staining; angiogenesis was assessed by immunoblotting for CD31; inflammatory factor levels were detected by ELISA. EGFL7 was verified as a target of miR-497-5p by bioinformatics website analysis and luciferase reporter gene assay. H2O2-injured neurons were cultured in vitro to explore the effect of TMP. Results: After SCI, miR-497-5p was upregulated while EGFL7 was downregulated in rats. TMP inhibited apoptosis and promoted angiogenesis, nerve regeneration, and repair of nerve defects by reducing miR-497-5p and increasing EGFL7 expression. miR-497-5p targeted EGFL7. In addition, TMP hindered neuronal inflammation and apoptosis induced by H2O2in vitro. Conclusion: TMP promotes angiogenesis by downregulating miR-497-5p to target EGFL7, and promotes nerve regeneration and repair of nerve defects in rats with SCI.

Correction: MMP-3 gene polymorphisms are associated with increased risk of osteoarthritis in Chinese men.

[This corrects the article DOI: 10.18632/oncotarget.18493.].

MMP-3 gene polymorphisms are associated with increased risk of osteoarthritis in Chinese men.

Osteoarthritis (OA) is the most common late-onset degenerative joint disease., It is characterized by progressive degradation of articular cartilage. We investigated the association between OA occurrence and single nucleotide polymorphisms (SNPs) in the matrix metalloproteinase-3 (MMP-3) gene involved in the breakdown of extra-cellular matrix proteins. The study included 100 male OA patients and 197 healthy men from the north area of China. Eight MMP-3 SNPs were genotyped. Odds ratios (ORs) with 95% confidence intervals (95%CIs) and multivariate logistic regression analysis were used to assess the association. Multivariate logistic regression analysis was used to identify SNPs that correlated with OA susceptibility. We found that rs639752 (dominant, OR = 2.03, 95% CI: 1.03-4.01, P = 0.038; over-dominant, OR = 2.00, 95% CI: 1.03-3.88, P = 0.037); rs520540 (dominant, OR = 2.03, 95% CI: 1.03-4.01, P = 0.038; over-dominant, OR = 2.00, 95% CI: 1.03-3.88, P = 0.037); rs602128 (dominant, OR = 2.03, 95% CI: 1.03-4.01, P = 0.038; over-dominant, OR = 2.01, 95% CI: 1.03-3.89, P = 0.037); and rs679620 (dominant, OR = 2.03, 95% CI: 1.03-4.01, P = 0.038; over-dominant, OR = 2.04, 95% CI: 1.05-3.96, P = 0.033) were associated with the increased risk of OA. Our results suggest that these SNPs may contribute to OA development, and could serve as molecular markers of OA susceptibility.

TIMP-2 SNPs rs7342880 and rs4789936 are linked to risk of knee osteoarthritis in the Chinese Han Population.

This study aimed to investigate whether functional polymorphisms in the tissue inhibitors of metalloproteinase-2 (TIMP-2) gene are associated with susceptibility to knee osteoarthritis (OA) in the Chinese Han population. Six TIMP-2 single nucleotide polymorphisms (SNPs) were assayed using MassARRAY in 300 patients clinically and radiographically diagnosed with knee OA and in 428 controls. Allelic and genotypic frequencies were compared between groups. Logistic regression adjusting for age and gender was used to estimate risk associations between specific genotypes and knee OA by computing odds ratios (ORs) and 95% confidence intervals (95% CIs). We found that allele "A" in rs7342880 was significantly associated with increased risk of knee OA (OR = 1.44, 95%CI = 1.09-1.91, p = 0.035). In addition, in the over-dominant model, rs4789936 correlated with reduced risk of knee OA, adjusting for age and gender (OR = 0.69, 95%CI = 0.49-0.98, p = 0.036). Finally, rs7342880 correlated with increased risk of knee OA in females. This study provides evidence that TIMP-2 is a knee OA susceptibility gene in the Chinese population and a potential diagnostic and preventive marker for the disease.

Association between GDF5 +104T/C polymorphism and knee osteoarthritis in Caucasian and Asian populations: a meta-analysis based on case-control studies.

BACKGROUND: Osteoarthritis (OA) is a degenerative joint disease with a complex genetic background. Variants in growth differentiation factor 5 (GDF5) have been reported to be associated with rheumatoid arthritis (RA) in several ethnic populations. The present study aimed to assess the association between the GDF5 +104T/C polymorphism and the susceptibility of the knee to OA through a meta-analysis of available case-control studies. METHODS: The PubMed and Science Direct citation databases were used to search electronic literature in order to identify studies published between January 2007 and July 2016 that evaluated the association between the GDF5 +104T/C polymorphism and the susceptibility of the knee to OA. Different genetic models were used to assess the pooled and stratified data. RESULTS: A positive association was found in all pooled studies (OR = 0.808, 95 % CI = 0.754-0.866, p < 0.001). Regarding genotypes, significant associations were found using a dominant model (OR = 0.777, 95 % CI = 0.708-0.852, p < 0.001), a recessive model (OR = 0.723, 95%CI = 0.623-0.839, p < 0.001), and an additive model (CC vs TT OR = 0.648, 95 % CI = 0.552-0.760, p < 0.001; CC vs CT OR = 0.801, 95 % CI = 0.685-0.936, p = 0.005). Meta-analysis data were stratified by ethnicity, and the GDF5 C allele was found to be positively associated with OA of the knee in both Caucasians and Asians, as were the GDF5 TC and CC genotypes. In addition, using an additive model, the CC genotype was found to be significantly associated with OA of the knee in both Caucasians and Asians when comparing CC vs TT genotypes, but not in Caucasians when comparing TT vs CT genotypes. CONCLUSIONS: Meta-analysis results indicated that the GDF5 +104T/C polymorphism is a protective factor for OA among Caucasian and Asian populations.

Hypoxia promotes AMP-activated protein kinase (AMPK) and induces apoptosis in mouse osteoblasts.

The hypoxic environment around the fracture site develops post the blood flow disruption and leads to osteoblast cell death and further impairs fracture healing. Hypoxia usually leads to the mitochondrial dysfunction and then results in apoptotic cell death. AMPK is ubiquitously expressed and functions as an intracellular fuel sensor by maintaining energy balance, as is potentially activated by hypoxia, ischemia, and ROS, however, the regulatory role of AMPK in hypoxia-induced apoptosis in osteoblasts and in the fracture healing has not been identified. In present study, we firstly determined the apoptosis induction by hypoxia in mouse osteoblastic MC3T3-E1 cells via examining the apoptotic cells and the activation of apoptosis-related molecules, then investigated the activation of AMPK signaling by hypoxia via analyzing the phosphorylation of AMPKα and ACC1, finally we explored the association of the AMPK activation with the hypoxia-induced apoptosis using loss-of-function strategy. Results demonstrated that hypoxia induced apoptosis in MC3T3-E1 cells and activated the AMPK signaling. And the knockdown of AMPK via chemical treatment or RNA interfering significantly decreased the hypoxia-induced apoptosis in MC3T3-E1 cells. Taken together, present study unveiled the regulatory role of AMPK signaling in the hypoxia-induced osteoblast apoptosis.

Improved Achilles tendon healing by early mechanical loading in a rabbit model.

OBJECTIVE: To investigate the structure and the attachment strength of a healing tendon-bone interface and the role of mechanical loading in tendon healing. METHODS: Sixty rabbits underwent unilateral detachment and repair of the Achilles tendon. Thirty animals were immobilized (Group A), and the others wereallowed loadingimmediately postoperatively (Group B). Animals were sacrificed at 4 weeks and evaluated for histological and biomechanical testing. Statistical analysis was performed with an independent t test with significance set at P = 0.05. RESULTS: The ultimate stress was greater in group B (4.598 ± 1.321 N/mm(2)) compared with the control group (3.388 ± 0.994 N/mm(2)) (P < 0.05). Similarly, a more organized tendon-to-bone interface with a larger area of chondrocytes was found in group B (P < 0.05). CONCLUSION: Mechanical loading improves the structure and the attachment strength of the healing tendon-to-bone interface.

Clinical outcome of endoprosthetic replacement for failed treatment of intertrochanteric fractures: A retrospective case series.

OBJECTIVE: The treatment methods for the failed internal fixation in elderly patients suffering from several osteoporostic fractures are still inconclusive. We aimed to evaluate the clinical effects of endoprosthetic replacement for failure treatment of intertrochanteric fracture. METHODOLOGY: A total of 13 patients with failed internal fixation for intertrochanteric fracture were collected between January 2002 and October 2009. All of them were treated with endoprosthetic replacement and followed up till October 2010. Four of them received total hip replacement and the remained nine received artificial bipolar femoral head replacement. Clinical and functional outcomes of patients were assessed. RESULTS: Of 13 patients, nine were females and four were males with the mean age of 76.5 years (SD, 11.7, range, 58-92 years) at the time of fracture. The average time of operation and follow-up was 124 minutes (89-187minutes) and 31 months (14-68 months), respectively. The average blood loss during the operation was 631 ml (450-1560 ml). All patients showed good pain relief and functional improvement. Final post-operative Harris and WOMAC scores were significantly improved from pre-operative levels (P<0.05). Only five patients showed operative complications. CONCLUSIONS: Our finding indicated that endoprosthetic replacement is an effective salvage procedure for failed internal fixation of intertrochanteric fracture in elderly patients with effective pain relief and functional improvement as well as few serious complications.

[Study on bone marrow mesenchymal stem cells derived osteoblasts and endothelial cells compound with chitosan/hydroxyapatite scaffold to construct vascularized tissue engineered bone].

OBJECTIVE: To explore the osteogenesis and angiogenesis effect of bone marrow mesenchymal stem cells (BMSCs) derived osteoblasts and endothelial cells compound with chitosan/hydroxyapatite (CS/HA) scaffold in repairing radial defect in rats. METHODS: The BMSCs were isolated from Sprague Dawley rats and the 3rd generation of BMSCs were induced into osteoblasts and endothelial cells. The endothelial cells, osteoblasts, and mixed osteoblasts and endothelial cells (1:1) were compound with CS/HA scaffold in groups A, B, and C respectively to prepare the cell-scaffold composites. The cell proliferation was detected by MTT. The rat radial segmental defect model was made and the 3 cell-scaffolds were implanted, respectively. At 4, 8, and 12 weeks after transplantation, the graft was harvested to perform HE staining and CD34 immunohistochemistry staining. The mRNA expressions of osteopontin (OPN) and osteoprotegerin (OPG) were detected by RT-PCR. RESULTS: Alkaline phosphatase staining of osteoblasts showed that there were blue grains in cytoplasm at 7 days after osteogenic induction and the nuclei were stained red. CD34 immunocytochemical staining of the endothelial cells showed that there were brown grains in the cytoplasm at 14 days after angiogenesis induction. MTT test showed that the proliferation level of the cells in 3 groups increased with the time. HE staining showed that no obvious osteoid formation, denser microvessel, and more fibrous tissue were seen at 12 weeks in group A; homogeneous osteoid which distributed with cord or island, and many osteoblast-like cells were seen in groups B and C. The microvessel density was significantly higher in groups A and C than group B at 3 time points (P < 0.05), and in group A than in group C at 12 weeks (P < 0.05). The OPN and OPG mRNA expressions of group A were significantly lower than those of groups B and C at 3 time points (P < 0.05). In groups B and C, the OPN mRNA expressions reached peak at 8 and 12 weeks, respectively, and OPG mRNA expressions reached peak at 4 weeks. CONCLUSION: BMSCs derived osteoblasts and endothelial cells (1:1) compound with CS/HA porous scaffold can promote bone formation and vascularization in bone defect and accelerate the healing of bone defect.

Comparison of surgical intervention with functional treatment for acute ruptures of lateral ankle ligmant: a meta-analysis.

OBJECTIVE: To compare the effect of surgical intervention on functional treatment. METHODS: By searching the MEDLINE (1966 to October 2011), EMBASE (1980 to October 2011), the Chinese Biomedical Database Databases (1980 to October 2011), a total of 9 related RCT studies comparing surgical intervention with functional treatment were included in our study. RevMan software was taken to analyze the data. RESULTS: These 9 studies involved a total of 1 268 mostly young adults, including 580 patients with surgical treatment and 688 patients with functional treatment. The results showed the stability of ankle activity in surgical treatment group was better than that in functional treatment group, with the OR and 95% CI of 0.72 (0.52-0.99). No significant difference was found in the recurrence of the surgical and functional group. However, the movement disorder in the surgical treatment suggested increased risk than that in functional group, with the OR and 95% CI of 2.39 (0.98-5.85). Surgical group found more complication than the function group, such as deep vein thrombosis, deep venous thrombosis, tenderness of scar and sensory loss. CONCLUSIONS: In conclusion, our finding showed that surgical treatment could gain better efficacy than functional treatment, but may bring more complication. Therefore, further large sample size RCT is warranted.