Objective By exploring the effects of recombinant human bone morphogenetic protein (rhBMP)2 and rhBMP13 on chondrocytes proteoglycan production and phenotype expression to establish the theoritical mechanisms for the treatment of disc degeneration with chondrocytes transplantation plus BMPs.Methods The dose-dependent effects of rhBMP2 and rhBMP13 on PG protein synthesis and gene expression were detected under different concentrations (0,25,125,and 625 ng/ml).The sulfated-glycosaminoglycan (s-GAG) in the culture media and the pericellular matrix was measured with a 1,9-dimethyl-methylene blue (DMMB) colorimetric assay.Reverse transcriptase polymerase chain reaction (RT-PCR) was performed respectively to quantify the relative abundance of aggrecan Mrna.Cell proliferation was examined by Hoechst Dye assay.Results All rhBMP2 and rhBMP13 in different concentrations could significantly increase s-GAG synthesis and gene expression in chondrocytes (P＜0.05).And at the same concentration.rhBMP2 was more potent than rhBMP13 on s-GAG synthesis.Hoechst Dye assay showed neither rhBMP2 nor rhBMP13 had significant effect on cell proliferation.Conclusion rhBMP2 and rhBMP13 are able to upregulate s-GAG synthesis,in addition,rhBMP2 is more potent than rhBMP13 on aggrecan gene expression regulation,but rhBMP2 and rhBMP13 do not have significant effect on chondrocyte proliferation.

BACKGROUND:Polyester fabric as a common clinical consumable item is characterized by simple drawing, low cost, and high toughness and ductility, and can serve as a good repair material. OBJECTIVE:To investigate the clinical efficacy of polyester fabrics used for huge chest wal repair. METHODS: Totaly 46 patients with chest wal tumors, aged 39-73 years, including 29 males and 17 females. These patients were randomly and equaly divided into observation group and control group. After the removal of chest wal tumors, patients in the observation group underwent polyester fabric repair of huge chest wal defects, and those in the control group were treated with autologous pedicle flap for repair of huge chest wal defects. The clinical efficacy and patient satisfaction were recorded in the two groups. RESULTS AND CONCLUSION: After treatment, al the patients could feel up to their daily work, and there were no death and serious complications. Only two cases developed postoperative local effusion, and then recovered after wound drainage. Thoracic appearance was good in al patients, and the patients did not feel discomfort at the reconstruction site during breathing and movement. At the end of 6-24 months of folow-up, X-ray review showed good reconstruction of the thorax, and there were no loose transplants, foreign body rejection, chest wal deformity, recurrence and serious complications. Clinical efficacy and patient satisfaction were better in theobservation group than the control group (P < 0.05). These results show that polyester fabrics for the repair of huge chest wal defects are effectively, safe and reliable.

Objective To develop retrovirus-mediated transfer of the fusion gene encoding EGFP-BMP2 in mesenchymal stem cells. Methods Mesenchymal stem cells from New Zealand white rabbits were transduced with retroviral pLEGFP-BMP2 vector by the optimized retroviral transduction protocol. Fluorescent microscopy's examination was to evaluate the results of the transduction, flow cytometer's analysis was to evaluate the transduction efficiency and the Fluorescence-activated cell sorting method was to sort the transduced cells. Bioactivity test from C2C12K4 cells was to show the expression and bio-activity of the fusion gene. Results Fluorescent microscopy showed the success of the transduction. By flow cytometer's analysis, the mean efficiency of the transduction with EGFP was (42.8±6.1)% SD. Transduced cells were sorted efficiently by the fluorescence-activated cell sorting method and after sorting, almost of those showed the expression of BMP2. Fluorescently and strongly bioactivity test for C2C12K4 cells demonstrated that fluorescent materials were located the surface of cells and the activity of luciferase increased compared with the control. Analysis of long-term expression showed there was no difference between 2 week-time point and 3 month-time point of culture post-sorting. Conclusion Mesenchymal stem cells can be transduced efficiently by retrovirus-mediated transfer of the fusion gene encoding EGFP-BMP2, the highly pure transduced cells are obtained by the fluorescence-activated cell sorting technique, the expressed chimeric protein embraced the double bioactivity of EGFP and BMP2, and moreover, the expression had not attenuated over time.

Objective To investigate the etiologic roles of apoptosis-associated genes,environmental factors and their interactions in lumbar disc herniation (LDH).Methods A case-control trial was conducted.We recruited 128 outpatients with LDH as case group and 132 normal people matched by age and gender as control group.Peripheral venous blood samples were collected and DNA was extracted from leukocytes.By using a modified Brucker Autoflex MALDI-TOF mass spectrometer,we analyzed 3 genes with 9 polymorphic sites,namely,Fas-1377G/A rs2234767,Fas-670G/A rs1800682,Fas rs2147420,Fas rs2296603,Fas rs7901 656,Fas rs1 57101 9,FasL-844C/T rs7631 10,CASP-9-1263A > G rs4645978,and CASP-9-712C > T rs4645981.The correlations between polymorphism of Fas,FasL and CASP-9 genes and the risk of LDH were evaluated by non-conditional Logistic regression model.Multiple Logistic regression model was performed to assess the interaction between apoptosis-associated genes and environment factors,such as lumbar vertebral loads,bed type,spare-time exercises and spare-time activities. Results There were preferable balances in case and control groups in age and gender without significant differences.However,the two groups differed significantly (P <0.05)in lumbar vertebral loads,body mass index, bed type, spare-time exercises and spare-time activities. Correlation analysis showed remarkable correlations between LDH and the polymorphisms of FasL-844C/T (rs7631 10)and CASP-9-1263A>G (rs4645978),and FasL-844C/T TT and CASP-9-1263A>G GG genotypes might be the high risk genotypes of LDH.The gene-environment interaction analysis revealed that super-multiplicative and sub-multiplicative interactions respectively between FasL-844TT genotype and lumbar vertebral loads (3-4 level),and between CASP-9-rs4645978 GG and lumbar vertebral loads (3-4 level).Conclusion FasL,CASP-9 genes and lumbar vertebral loads and their interactions play important roles in the pathogenesis of LDH.It suggests that the risk of LDH may be codetermined by environmental factors and inherited susceptibility genes,and that the mechanisms of interactions vary in different genotypes and the same or different environmental factors.

In this review we summarize the progress made towards understanding the role of protein-protein interactions in the function of various bioluminescence systems of marine organisms, including bacteria, jellyfish and soft corals, with particular focus on methodology used to detect and characterize these interactions. In some bioluminescence systems, protein-protein interactions involve an "accessory protein" whereby a stored substrate is efficiently delivered to the bioluminescent enzyme luciferase. Other types of complexation mediate energy transfer to an "antenna protein" altering the color and quantum yield of a bioluminescence reaction. Spatial structures of the complexes reveal an important role of electrostatic forces in governing the corresponding weak interactions and define the nature of the interaction surfaces. The most reliable structural model is available for the protein-protein complex of the Ca(2+)-regulated photoprotein clytin and green-fluorescent protein (GFP) from the jellyfish Clytia gregaria, solved by means of Xray crystallography, NMR mapping and molecular docking. This provides an example of the potential strategies in studying the transient complexes involved in bioluminescence. It is emphasized that structural studies such as these can provide valuable insight into the detailed mechanism of bioluminescence.
Animals ; Anthozoa ; physiology ; Aquatic Organisms ; physiology ; Bacteria ; metabolism ; Binding Sites ; Calcium ; metabolism ; Crystallography, X-Ray ; Fluorescence Resonance Energy Transfer ; Green Fluorescent Proteins ; metabolism ; Hydrozoa ; physiology ; Imidazoles ; metabolism ; Luciferases ; metabolism ; Luminescent Measurements ; instrumentation ; methods ; Luminescent Proteins ; metabolism ; Models, Molecular ; Protein Binding ; Pteridines ; metabolism ; Pyrazines ; metabolism ; Scyphozoa ; physiology ; Spectrometry, Fluorescence

Uch37 is a de-ubiquitinating enzyme that is activated by Rpn13 and involved in the proteasomal degradation of proteins. The full-length Uch37 was shown to exhibit low iso-peptidase activity and is thought to be auto-inhibited. Structural comparisons revealed that within a homo-dimer of Uch37, each of the catalytic domains was blocking the other's ubiquitin (Ub)-binding site. This blockage likely prevented Ub from entering the active site of Uch37 and might form the basis of auto-inhibition. To understand the mode of auto-inhibition clearly and shed light on the activation mechanism of Uch37 by Rpn13, we investigated the Uch37-Rpn13 complex using a combination of mutagenesis, biochemical, NMR, and small-angle X-ray scattering (SAXS) techniques. Our results also proved that Uch37 oligomerized in solution and had very low activity against the fluorogenic substrate ubiquitin-7-amino-4-methylcoumarin (Ub-AMC) of de-ubiquitinating enzymes. Uch37Δ(Hb,Hc,KEKE), a truncation removal of the C-terminal extension region (residues 256-329) converted oligomeric Uch37 into a monomeric form that exhibited iso-peptidase activity comparable to that of a truncation-containing the Uch37 catalytic domain only. We also demonstrated that Rpn13C (Rpn13 residues 270-407) could disrupt the oligomerization of Uch37 by sequestering Uch37 and forming a Uch37-Rpn13 complex. Uch37 was activated in such a complex, exhibiting 12-fold-higher activity than Uch37 alone. Time-resolved SAXS (TR-SAXS) and FRET experiments supported the proposed mode of auto-inhibition and the activation mechanism of Uch37 by Rpn13. Rpn13 activated Uch37 by forming a 1:1 stoichiometric complex in which the active site of Uch37 was accessible to Ub.
Binding Sites ; Catalytic Domain ; Chromatography, Gel ; Crystallography, X-Ray ; Humans ; Membrane Glycoproteins ; chemistry ; genetics ; metabolism ; Nuclear Magnetic Resonance, Biomolecular ; Protein Binding ; Protein Conformation ; Protein Multimerization ; Scattering, Small Angle ; Ubiquitin Thiolesterase ; chemistry ; genetics ; metabolism ; Ultracentrifugation

【Objective】 To investigate the effects of biomimetic bone trabecular with the same porosity and pore size and regular porous structure on the adhesion, proliferation, and differentiation of osteoblasts, so as to provide theoretical basis for the improvement of osseointegration performance of titanium alloy implants. 【Methods】 The biomimetic bone trabecular and regular porous structures with the same porosity and pore size were generated by computer-aided software, and then processed into disc-shaped Ti6Al4V scaffolds with a diameter of 10 mm and a height of 3 mm by selective laser melting technology. MC3T3-E1 cells, the precursor cells of mouse osteoblasts in the logarithmic growth phase, were seeded on two kinds of scaffolds and divided into biomimetic bone trabecular group and regular porous structure group. After 3 hours of culture, acridine orange staining and phalloidin /DAPI staining were used to evaluate the number of cell adhesion. After 3 days of culture, the scaffolds were examined by scanning electron microscopy to evaluate the adhesion state of cells. After 1, 3, and 5 days of culture, the scaffolds were taken for CCK8 detection to observe the proliferation of cells. After 7 and 14 days of differentiation, alkaline phosphatase (ALP) activity was detected. After 14 days of differentiation, the expressions of osteogenesis-related genes (ALP, OCN, RUNX2) were detected by RT-PCR. After 30 days of differentiation, the scaffolds were stained with alizarin red and 100 g/L cetylpyridinium chloride was used to dissolve mineralized nodules. Calcium salt deposition was qualitatively and quantitatively detected to evaluate cell differentiation. 【Results】 The results of acridine orange and phalloidin /DAPI staining showed that the biomimetic trabecular Ti6Al4V scaffold adhered to more MC3T3-E1 cells than the regular porous structure, and the cytoskeleton of the former scaffold was more densely distributed. The results of scanning electron microscopy showed that the pseudopodia of MC3T3-E1 cells on the biomimetic bone trabecular Ti6Al4V scaffold were longer and the extension state was better than that of the regular porous structure. CCK8 test showed that the proliferation of MC3T3-E1 cells on the biomimetic trabecular bone titanium alloy scaffold was significantly higher than that on the regular porous structure on the 3rd and 5th day, and the difference gradually increased with the increase of time, with statistical significance (P<0.05). The results of cell differentiation test showed that ALP activity on the bionic trabecular scaffold was higher than that on the regular porous structure (P<0.05). The expressions of osteogenic genes (ALP, OCN, RUNX2) in MC3T3-E1 cells on the biomimetic bone trabecular titanium alloy scaffold were significantly higher than those on the regular porous structure (P<0.05). After 30 days of induction, the amount of calcium salt deposited in the bionic trabecular titanium alloy scaffold was significantly larger than that in the regular porous structure (P<0.05). 【Conclusion】 The biomimetic bone trabecular with a porosity of 65% and an equivalent pore size of 600 μm is more conducive to the adhesion, proliferation and differentiation of mouse osteoblast precursor cells MC3T3-E1 on the titanium alloy scaffold than the regular porous structure with the same porosity and pore size. It is theoretically more conducive to improving the osseointegration performance of titanium alloy implants.