Overexpression of LINC00261 inhibits non-small cell lung cancer cells progression by interacting with miR-522-3p and suppressing Wnt signaling.

Long noncoding RNA LINC00261 has been experimentally validated to function as a tumor suppressor in several cancers, but its pathological role and functional mechanism in non-small cell lung cancer (NSCLC) are largely unclear. In this study, LINC00261 was delineated in NSCLC to be significantly downregulated in cancer tissues compared with corresponding adjacent normal tissues. Low expression of LINC00261 predicted worse survival for patients with NSCLC. Overexpression of LINC00261 in NSCLC cell lines inhibited cell proliferation and invasion, meanwhile promoted apoptosis. Subcellular fractionation assay showed that LINC00261 existed mainly in the cytoplasm of NSCLC A549 cells and luciferase assay validated its direct interaction with miR-522-3p. Overexpression of miR-522-3p significantly ameliorated suppressive effects of LINC00261 on proliferation and invasion of NSCLC cells. Besides, miR-522-3p was found to be able to directly combine with the 3'-untranslated region of SFRP2, which was generally regarded as a suppressor of Wnt signaling. Further quantitative reverse transcription polymerase chain reaction and Western blot experiments showed that LINC00261 upregulation potentiated the expression of SFRP2 and inhibited Wnt signaling pathway, which could both be reversely modulated by miR-522-3p. Taken together, our study demonstrated that LINC00261 suppressed NSCLC cells progression via sponging miR-522-3p and inhibiting Wnt signaling. These results supported us to better understand the pathogenic mechanism of NSCLC and revealed a potential molecular target for this fatal disease.

Enhanced osteogenesis of bone marrow stem cells cultured on hydroxyapatite/collagen I scaffold in the presence of low-frequency magnetic field.

As a non-invasive biophysical therapy, electromagnetic fields (EMF) have been widely used to promote the healing of fractures. In the present study, hydroxyapatite/collagen I (HAC) loaded with rabbit bone marrow mesenchymal stem cells (MSCs) were cultured in a dynamic perfusion bioreactor and exposed to EMF of 15 Hz/1mT. Osteogenic differentiation of the seeded cells was analyzed through the evaluation of ALP activity and osteogenesis-related genes expression in vitro. The in vivo osteogenesis efficacy of the cell laden HAC constructs treated with/without EMF was evaluated through a rabbit femur condyle defect model. The results showed that EMF of 15 Hz/1mT could enhance the osteogenic differentiation of the cells seeded on HAC scaffold. Furthermore, the in vivo experiments demonstrated that EMF exposure could promote bone regeneration within the defect and bone integration between the graft and host bone. Taking together, the MSCs seeded HAC scaffold combined with EMF exposure could be a promising approach for bone tissue engineering.

Conjugated linoleic acid prevents age-induced bone loss in mice by regulating both osteoblastogenesis and adipogenesis.

Osteoporosis (OP) can increase the risk of bone fracture and other complications, which is a major clinical problem. Previous researches have revealed that conjugated linoleic acid (CLA) can promote the bone formation. But the mechanisms are not clear. Thus, we tested the hypothesis that CLA acts on bone formation might be via mTOR Complex1 (mTORC 1) pathway by in vitro and vivo assays. We studied the effect of CLA mix on MC3T3-E1 pre-osteoblasts differentiation into osteoblasts, and bone formation under osteoporotic conditions. At the same time, 3T3-L1 pre-adipocyte with the same CLA mix concentration gradient for 8 days with adipogenic differentiation medium. We found that Alkaline phosphatase (ALP), runt-related transcription factor 2 (RUNX2) and osteocalcin (OCN) expressions of pre-osteoblasts were up-regulated. Moreover in presence of CLA, peroxisome proliferators-activated receptor γ(PPARγ) and CCAAT/enhancer-binding protein (C/EBPα) were down-regulated. Osteoporosis mice bone parameters in the distal femoral meraphysis were significantly increased compared with placebo mice. Furthermore, the phosphor-S6 (P-S6) was suppressed and phosphor-AKT (P-AKT) was up-regulated. Consistently, CLA can stimulate differentiation of osteoblasts and inhibited pre-adipocytes differentiated into adipocytes via AKT/mTORC1 signal pathway. Overall CLA thus be a suitable candidate for the treatment of patients with postmenopausal osteoporosis and obesity.

Deformation grating fabrication technique based on the solvent-assisted microcontact molding.

A deformation grating fabrication technique based on solvent-assisted microcontact molding (SAMIM) is reported in this paper. The fabrication process can be divided into three steps: imprinting a grating on a medium polymer substrate (MPS) by SAMIM, coating a thin metal film on the MPS, and transferring the film to the measured surface. In order to increase the stiffness of the elastic mold without decreasing its conformal contact formation ability, a re-useable, glass-embedded polydimethylsiloxane (PDMS) mold is used. In addition, a characterization method based on the Fourier transform and phase analysis is proposed to check the quality of the fabricated grating. Verified by experiment, the proposed fabrication technique can fabricate a high-frequency large-area grating on different specimens, which can be a qualified deformation sensor for the moiré method.

Error evaluation technique for three-dimensional digital image correlation.

Three-dimensional (3D) digital image correlation (DIC) is one of the most popular techniques used in engineering for strain and deformation measurement. However, the error analysis of 3D DIC, especially which kind of parameters dominates the error of 3D coordinate reconstruction in any kind of configuration, is still under study. In this paper, a technique that can be used for error determination of reconstruction is presented. The influence from the system calibration and image correlation to the error is theoretically analyzed. From numerical experiments of one-dimensional line and two-dimensional plane, the evaluation procedure is validated to be flexible. A typical test with standard objects is also conducted. With this technique, once a 3D DIC system is set up and images of objects with speckles and calibration boards are recorded, the error of the configuration can be immediately evaluated. The standard deviation of every point in the world coordinate can be determined by statistical analysis.

Hydrogel-hydroxyapatite-monomeric collagen type-I scaffold with low-frequency electromagnetic field treatment enhances osteochondral repair in rabbits.

BACKGROUND: Cartilage damage is a common medical issue in clinical practice. Complete cartilage repair remains a significant challenge owing to the inferior quality of regenerative tissue. Safe and non-invasive magnetic therapy combined with tissue engineering to repair cartilage may be a promising breakthrough. METHODS: In this study, a composite scaffold made of Hydroxyapatite-Collagen type-I (HAC) and PLGA-PEG-PLGA thermogel was produced to match the cartilage and subchondral layers in osteochondral defects, respectively. Bone marrow mesenchymal stem cells (BMSC) encapsulated in the thermogel were stimulated by an electromagnetic field (EMF). Effect of EMF on the proliferation and chondrogenic differentiation potential was evaluated in vitro. 4 mm femoral condyle defect was constructed in rabbits. The scaffolds loaded with BMSCs were implanted into the defects with or without EMF treatment. Effects of the combination treatment of the EMF and composite scaffold on rabbit osteochondral defect was detected in vivo. RESULTS: In vitro experiments showed that EMF could promote proliferation and chondrogenic differentiation of BMSCs partly by activating the PI3K/AKT/mTOR and Wnt1/LRP6/ß-catenin signaling pathway. In vivo results further confirmed that the scaffold with EMF enhances the repair of osteochondral defects in rabbits, and, in particular, cartilage repair. CONCLUSION: Hydrogel-Hydroxyapatite-Monomeric Collagen type-I scaffold with low-frequency EMF treatment has the potential to enhance osteochondral repair.

Selonsertib Alleviates the Progression of Rat Osteoarthritis: An in vitro and in vivo Study.

Osteoarthritis (OA) is a prevalent degenerative joint disease. Its development is highly associated with inflammatory response and apoptosis in chondrocytes. Selonsertib (Ser), the inhibitor of Apoptosis Signal-regulated kinase-1 (ASK1), has exhibited multiple therapeutic effects in several diseases. However, the exact role of Ser in OA remains unclear. Herein, we investigated the anti-arthritic effects as well as the potential mechanism of Ser on rat OA. Our results showed that Ser could markedly prevent the IL-1ß-induced inflammatory reaction, cartilage degradation and cell apoptosis in rat chondrocytes. Meanwhile, the ASK1/P38/JNK and NFκB pathways were involved in the protective roles of Ser. Furthermore, intra-articular injection of Ser could significantly alleviate the surgery induced cartilage damage in rat OA model. In conclusion, our work provided insights into the therapeutic potential of Ser in OA, indicating that Ser might serve as a new avenue in OA treatment.

Electromagnetic field treatment increases purinergic receptor P2X7 expression and activates its downstream Akt/GSK3ß/ß-catenin axis in mesenchymal stem cells under osteogenic induction.

BACKGROUND: Imbalance in bone formation and resorption is a crucial component of the pathological process leading to osteoporosis. Electromagnetic fields (EMFs) have been reported to be beneficial to osteogenesis, although the exact mechanism has not been fully clarified. Purinergic receptor P2X7 is expressed in osteoblasts and is reported to participate in the regulation of bone metabolism. OBJECTIVES: To elucidate the link between EMFs and P2X7 expression and investigate its potential as a novel therapeutic target in osteoporosis. METHOD: We investigated the effect of EMFs on P2X7 expression and downstream signaling in human bone marrow mesenchymal stem cells (h-MSCs). We also established an ovariectomized (OVX) osteoporosis rat model to evaluate the therapeutic efficacy of combining EMFs with P2X7 agonists. RESULTS: EMF treatment increased P2X7 expression in h-MSCs under conditions of osteogenic induction but not under regular culture conditions. P2X7 or PI3K/Akt inhibition partially inhibited the pro-osteogenic effect of EMF and lowered the EMF-stimulated activity of the Akt/GSK3ß/ß-catenin axis. No additive effect of this suppression was observed following simultaneous inhibition of P2X7 and PI3K/Akt. EMF treatment in the presence of a P2X7 agonist had a greater effect in increasing osteogenic marker expression than that of EMF treatment alone. In the OVX osteoporosis model, the therapeutic efficacy of combining EMFs with P2X7 agonists was superior to that of EMF treatment alone. CONCLUSIONS: EMF treatment increases P2X7 expression by h-MSCs during osteogenic differentiation, leading to activation of the Akt/GSK3ß/ß-catenin axis, which promotes the osteogenesis. Our findings also indicate that combined EMF and P2X7 agonist treatment may be an effective novel strategy for osteoporosis therapy.

Upregulation of UBAP2L in Bone Marrow Mesenchymal Stem Cells Promotes Functional Recovery in Rats with Spinal Cord Injury.

Post-translational modifications of cellular proteins with ubiquitin or ubiquitin-like proteins regulate many cellular processes, such as cell proliferation, differentiation, apoptosis, signal transduction, intercellular immune recognition, inflammatory response, stress response, and DNA repair. Nice4/UBAP2L is an important member in the family of ubiquitin-like proteins, and its biological function remains unknown. This study aimed to investigate the effect of UBAP2L on spinal cord injury (SCI). At first, rat bone marrow mesenchymal stem cells (BMSCs) were infected with adeno-associated virus to induce over-expression of Nice4. Subsequently, the infected BMSCs were transplanted into rats suffering from semi-sectioned SCI. The results showed that the over-expression of Nice4 significantly promoted the proliferation and differentiation of BMSCs. In addition, the transplantation of infected BMSCs into the injured area of SCI rats improved the function repair of SCI. Importantly, the immunohistochemical and hematoxylin-eosin staining and RT-PCR results showed that the number of neuronal cells, oligodendrocytes, and astrocytes was significantly increased in the injured area, along with significantly upregulated expression of cyclin D1 and p38 mitogen-activated protein kinase (MAPK). Meanwhile, the expression of caspase 3 protein was significantly down-regulated. In conclusion, the over-expression of Nice4 gene can promote the functional recovery in SCI rats by promoting cell proliferation and inhibiting apoptosis. The results of this study indicate an alternative option for the clinical treatment of SCI.

Influence of Temperature on the Mechanical Properties and Reactive Behavior of Al-PTFE under Quasi-Static Compression.

Al-PTFE (aluminum-polytetrafluoroethylene) is a typical kind of Reactive Material (RM), which has a variety of potential applications in weapon systems. In this paper, quasi-static compression experiments were carried out for a pressed and sintered mixture of Al and PTFE powders using a microcomputer-controlled electronic universal testing machine. The results show that both the mechanical property and reactive behavior of Al-PTFE are strongly temperature-dependent. The material undergoes a brittle-ductile transition associated with a temperature-induced crystalline phase transformation of the PTFE matrix. At low temperatures (-18, 0, and 16 °C), samples of Al-PTFE failed with shear crack and no reaction was observed. As the temperature increased (22, 35, and 80 °C), Al-PTFE exhibited a high toughness and violent reaction occurred in all of the tested samples. Scanning electron microscope observations showed different fracture mechanisms of the PTFE matrix and the increase in toughness was due to the formation of PTFE fibrils which could dissipate energy and bridge crack plane during plastic deformation.

Investigation on the Thermal Behavior, Mechanical Properties and Reaction Characteristics of Al-PTFE Composites Enhanced by Ni Particle.

Al-PTFE (aluminum-polytetrafluoroethene) is regarded as one of the most promising reactive materials (RMs). In this work, Ni (Nickel) was added to Al-PTFE composites for the purpose of improving the energy density and damage effect. To investigate the thermal behavior, mechanical properties and reaction characteristics of the Al-Ni-PTFE composites, an Al-PTFE mixture and an Al-Ni mixture were prepared by ultrasonic mixing. Six types of Al-Ni-PTFE specimens with different component mass ratios were prepared by molding sintering. Simultaneous thermal analysis experiments were carried out to characterize the thermal behavior of the Al-PTFE mixture and the Al-Ni mixture. Quasi-static compression tests were performed to analyze the mechanical properties and reaction characteristics of the Al-Ni-PTFE specimens. The results indicate that the reaction onset temperature of Al-Ni (582.7 °C) was similar to that of Al-PTFE (587.6 °C) and that the reaction heat of Al-Ni (991.9 J/g) was 12.5 times higher than that of Al-PTFE (79.6 J/g). With the increase of Ni content, the material changed from ductile to brittle and the strain hardening modulus and compressive strength rose first and then subsequently decreased, reaching a maximum of 51.35 MPa and 111.41 MPa respectively when the volume fraction of Ni was 10%. An exothermic reaction occurred for the specimens with a Ni volume fraction no more than 10% under quasi-static compression, accompanied by the formation of Ni-Al intermetallic compounds. In the Al-Ni-PTFE system, the reaction between Al and PTFE preceded the reaction between Al and Ni and the feasibility of increasing the energy density and damage effect of the Al-Ni-PTFE reactive material by means of Ni-Al reaction was proved.

The synergistic effect of bone forming peptide-1 and endothelial progenitor cells to promote vascularization of tissue engineered bone.

Large segmental bone defect repair remains a challenge in orthopedic surgeries. The tissue engineered bone graft will be a promising approach if vascularization of the graft is realized. In this study, beta-tricalcium phosphate (ß-TCP) scaffold incorporated with bone forming peptide-1 (BFP-1) was fabricated. Endothelial progenitor cells (EPCs) were introduced as well. We investigated the effect of BFP-1 on the proliferation, differentiation, and angiogenic functions of EPCs. Additionally, segmental femur bone defect was created in rabbits. Prevascularized ß-TCP scaffold was constructed and implanted into the bone defect. The vascularization and bone formation were evaluated after 4 and 12 weeks. The results showed that BFP-1 promoted the angiogenesis of EPCs through activating the activin receptor-like kinase-1/Smad pathway. The prevascularized tissue engineered bone graft enhanced capillary vessel in-growth and new bone formation. Significantly higher values of vascularization and radiographic grading scores were observed in groups involving EPCs and BFP-1, compared to ß-TCP scaffold alone. In conclusion, the synergy between EPCs and BFP-1 improved the vascularization and new bone regeneration, which has great potentials in clinical applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1008-1021, 2018.

The Effect of Crystallinity on Compressive Properties of Al-PTFE.

Al-PTFE (Al-polytetrafluoroethene) is an important kind of Reactive Material (RM), however only limited importance was placed to the effect of crystallinity of PTFE on the mechanical and reactive behavior. This paper investigated the influence of crystallinity on the compression behavior of Al-PTFE at strain rates range from 10-2 to 3 × 10³ s-1. Two kinds of samples were prepared by different sintering procedures to acquire different crystallinity. The samples' crystallinity was characterized by the density method and X-ray diffraction method. The samples were tested using an electro-hydraulic press for quasi-static loading, and split Hopkinson pressure bars (SHPBs) for high strain rates. Low crystalline samples have consistently higher strength and toughness than the high crystalline samples. The phenomenon was explained by an "elastic-plastic network" model combined with the effect of chain entanglement density. A bilinear dependence of true stress on log ε ˙ was observed, and Johnson-Cook models were fitted separately according to the different strain rate sensitivity. Finally, a close connection between fracture and initiation of Al-PTFE was confirmed in quasi-static tests, SHPB tests, and drop weight tests. It was hypothesized that the high temperature at the crack tips of PTFE is an important promoting factor of initiation.