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To compare the expression level of metastasis associated-1 (MTA1) gene in high and low metastatic human osteosarcoma cell lines and examine the relationship of MTA1 expression and the metastasis potentiality of osteosarcoma cells the expression of MTA1 in MG-63 osteosarcoma cell lines with high and low metastasis potential was detected by semiquantitative TR-PCR. Boyden chamber invasion assay was used to evaluate the invasive capacity in vitro in two osteosarcoma cell lines. The low metastasis MG-63 cells were transfected with MTA1 full-length cDNA expression plasmid by lipofectamine and the changes of MTA1 expression and in vitro invasion potential were examined after the transfection. Our results showed that MG63 cell line with high metastasis potential expressed significantly higher MTA1 than that of MG63 cells with low metastasis as reavealed by RT-PCR. The invasion potential of low metastasis MG63 cell line was increased after MTA1 gene transfection. It is concluded that there may be a relationship between MTA1 and invasive potentiality of human osteosarcoma cells, and the mechanism of MTA1 in osteosarcoma metastasis and its possible role in associated gene therapy deserve further study. [ABSTRACT FROM AUTHOR]

By culturing bone marrow mesenchymal stem cells of rabbits with fibrin glue in vitro, the biocompatibility of fibrin glue was investigated to study whether this material can be used as scaffolds in bone tissue engineering. After 2-months old New Zealand rabbits had been anesthetized, about 4–6 ml of bone marrow were aspirated from rabbit femoral trochanter. The monocytes suspension was aspirated after bone marrow was centrifuged with lymphocyte separating medium and cultured primarily. Then the cells were divided into two groups: one was cultured with complete medium and the other with induced medium. The cells of the two groups were collected and inoculated to the culture plate containing fibrin glue. In the control group, cells were inoculated without fibrin glue. The implanted cells and materials were observed at different stages under a phase-contrast microscope and scanning electron microscope. MTT and alkaline phosphatase (ALP) were measured. Bone marrow mesenchymal stem cells grew on the surface of fibrin glue and adhered to it gradually. Cells light absorption value (A value) and the ALP content showed no significant difference. Fibrin glue had no inhibitory effect on cell morphology, growth, proliferation and differentiation. It has good biocompatibility and can be used as scaffold materials for bone marrow mesenchymal stem cells in bone tissue engineering. [ABSTRACT FROM AUTHOR]

Objective: To find out a method of extraction and purification of bone morphogenetic protein (BMP) from osteosarcoma cell conditioned medium, and evaluate the biological activity of BMP. Methods: Conditioned medium of osteosarcoma cell lines (MG-63) was collected, concentrated and dialyzed. The concentrated protein was purified through gel chromatography on Sephcryl-S-100. The purified protein was tested by BMP monoclonal antibody (McAb), its molecular weight (MW) was determined by SDS-PAGE and its biological activity was demonstrated by heterotopic ossification. Results: The purified protein was proved to be BMP by BMP McAb, had a satisfactory heterotopic ossification, and its MW was about 21 kD. Conclusion: BMP existed in the conditioned medium of osteosarcoma cell and had a satisfactory biological activity after purification. Because osteosarcoma cell can be cultured and grew for a long time in vitro, this method will be helpful to a vast extraction of BMP and clinical application. [ABSTRACT FROM AUTHOR]

In this paper, a fiber laser marking machine was used to pretreat an Al plate, and then a Au nanoparticle (Au NP) solution was dripped on the surface of the pre-treated plate to study the effect of the laser pretreatment assisted-nanoparticle-enhanced laser-induced breakdown spectroscopy technique on the emission and stability of the AlO molecular bands (B2P+ - X2P, Dn = 0) in the Al plasma. The results showed that laser pretreatment significantly improved the emission and stability of the AlO molecular bands. Therefore, this paper demonstrates the potential of laser pretreatment in improving analytical sensitivity in LIBS. [ABSTRACT FROM AUTHOR]

We present a scheme to prepare a single rotational state with high probability from an arbitrary superposition state. The NO molecule is used as a computational example. By using a series of linearly and circularly polarized laser pulses and adjusting their parameters, a ground rotational state with probability of 99.982% can be obtained. Starting from the ground rotational state prepared, we can prepare any desired single rotational state with high probability and some rotational superposition states. On this basis, the molecular orientation with initial thermal distribution can be considerably enhanced and well controlled. [ABSTRACT FROM AUTHOR]

Precartilaginous stem cells(PCSC) are adult stem cells which control limb growth of animal and can differentiate directionally. In previous study, we found PCSC begin differentiating at the 5th passage, sufficient uniphenotype PCSC can not be harvested by primary cell culture. Therefore, we focused in this study to understand whether simian virus 40 large T antigen gene (SV40Tag) can induce rat PCSC to immortalize. Immunomagnetic separation was used to isolate PCSC labeled with fibroblast growth factor receptor-3(FGFR-3). Plasmid pCMVSV40T/PUR containing SV40Tag was transfected into PCSC by liposome transfection method. One anti-puromycin cell clone was obtained, which was confirmed as FGFR-3 positive, and expanded to immortalized cell strain. Results from RT-PCR and Southern blot demonstrated that mRNA and protein of SV40Tag was highly expressed after stable transfection. The cells transfected with SV40Tag were expanded to immortalized cell strain which could maintain its characteristics for 30 passages, named immortalized precartilaginous stem cells(IPCSC). IPCSC were short fusiform or triangular cells with two or three short axons. The high proliferation capability of IPCSC was confirmed by FGFR-3, Collagen II, PCNA staining and MTT assay. Therefore, we conclude that rat precartilaginous stem cells were purifued and immortalized precartilaginous stem cell strain was established. It will provides a stable cell resource for basic research and cell transplantation therapies. [ABSTRACT FROM AUTHOR]

Cancer is one of the leading causes of death worldwide and a major global health problem. In recent decades, the rates of both mortality and morbidity of cancer have rapidly increased for a variety of reasons. Despite treatment options, there are serious side effects associated with chemotherapy drugs and multiple forms of drug resistance that significantly reduce their effects. There is an accumulating amount of evidence on the pharmacological activities of baicalein (e.g., anti-inflammatory, antioxidant, antiviral, and antitumor effects). Furthermore, there has been great progress in elucidating the target mechanisms and signaling pathways of baicalein's anti-cancer potential. The anti-tumor functions of baicalein are mainly due to its capacities to inhibit complexes of cyclins to regulate the cell cycle, to scavenge oxidative radicals, to attenuate mitogen activated protein kinase (MAPK), protein kinase B (Akt) or mammalian target of rapamycin (mTOR) activities, to induce apoptosis by activating caspase-9/-3 and to inhibit tumorinvasion and metastasis by reducing the expression of matrix metalloproteinase-2/-9 (MMP-2/-9). In this review, we focused on the relevant biological mechanisms of baicalein involved in inhibiting various cancers, such as bladder cancer, breast cancer, and ovarian cancer. Moreover, we also summarized the specific mechanisms by which baicalein inhibited the growth of various tumors in vivo. Taken together, baicalein may be developed as a potential, novel anticancer drug to treat tumors. [ABSTRACT FROM AUTHOR]

We evaluated the role of the CXCL12/CXCR4 (C-X-C motif chemokine ligand 12/C-X-C chemokine receptor type 4) axis in aggrecanase-mediated cartilage degradation, and explored the underlying mechanism in a post-traumatic osteoarthritis rat model. Expression of CXCL12/CXCR4 and ADAMTS-5 was analyzed in the knees of osteoarthritic and non-arthritic rats using Western blot, ELISA, immunohistochemistry and immunofluorescence. Rodent studies were performed using Sprague-Dawley rats, with animals divided into three groups: Destabilization of the medial meniscus/AMD3100-treated (DMM/AMD3100-treated), DMM/PBS-treated, and sham controls. Rats were sacrificed after eight weeks, and samples were collected for histology and immunohistochemistry analyses. IL-1-pretreated primary chondrocytes were cultured with untreated control, CXCL12a, siNC + CXCL12a, or siRNA CXCR4 + CXCL12a, and analyzed for expression of relevant markers and cellular pathways. Higher levels of CXCL12 were detected in the knee fluid of osteoarthritic subjects, with strong staining for CXCR4 in chondrocytes and CXCL12 in synoviocytes together with enhanced expression of ADAMTS-5. DMM/AMD3100-treated rats showed a significantly reduced immunological response, with minimal evidence of pathology in both histological and immunohistochemical analyses. Treatment with CXCL12a increased the expression of ACAN, RUNX-2, and ADAMTS-4/5 in IL-1-pretreated primary chondrocytes, together with a decrease in the expression of SOX-9. Molecular analyses revealed strong induction of NF-κB activation, along with phosphorylation of MAPKs, and activation of canonical Wnt/β-catenin signaling. In conclusion, inhibition of SDF-1α/CXCR4 signaling axis was able to inhibit aggrecanase expression and lessen cartilage degeneration in post-traumatic osteoarthritis rats. [ABSTRACT FROM AUTHOR]

Previous studies showed that SDF-1 is a catabolic factor that can infiltrate cartilage, decrease proteoglycan content, and increase MMP-13 activity. Inhibiting the SDF-1 /CXCR4 signalling pathway can attenuate the pathogenesis of osteoarthritis (OA). Recent studies have also shown that SDF-1 enhances chondrocyte proliferation and maturation. These results appear to be contradictory. In the current study, we used a destabilisation OA animal model to investigate the effects of SDF-1 /CXCR4 signalling in the tibial subchondral bone and the OA pathological process. Post-traumatic osteoarthritis (PTOA) mice models were prepared by transecting the anterior cruciate ligament (ACLT), or a sham surgery was performed, in a total of 30 mice. Mice were treated with phosphate buffer saline (PBS) or AMD3100 (an inhibitor of CXCR4) and sacrificed at 30 days post ACLT or sham surgery. Tibial subchondral bone status was quantified by micro-computed tomography (μCT). Knee-joint histology was analysed to examine the articular cartilage and joint degeneration. The levels of SDF-1 and collagen type I c-telopeptidefragments (CTX-I) were quantified by ELISA. Bone marrow mononuclear cells (BMMCs) were used to clarify the effects of SDF-1 on osteoclast formation and activity in vivo. μCT analysis revealed significant loss of trabecular bone from tibial subchondral bone post-ACLT, which was effectively prevented by AMD3100. AMD3100 could partially prevent bone loss and articular cartilage degeneration. Serum biomarkers revealed an increase in SDF-1 and bone resorption, which were also reduced by AMD3100. SDF-1 can promote osteoclast formation and the expression oftartrate resistant acid phosphatase (TRAP), cathepsin K (CK), and matrix metalloproteinase (MMP)-9 in osteoclasts by activating the MAPK pathway, including ERK and p38, but not JNK. In conclusion, inhibition of SDF-1 /CXCR4signalling was able to prevent trabecular bone loss and attenuated cartilage degeneration in PTOA mice. [ABSTRACT FROM AUTHOR]