In order to construct the expression recombinant of human receptor associated protein (RAP), optimize its expression condition and obtain the recombinant protein after expression with high efficiency, two prokaryotic expression vectors—pT7-PL and pET-28a(+) were used to construct the expression recombinant containing RAP cDNA, and the expression efficiency of two kinds of expression E. coli of BL21 strains was compared. The effect of different induction conditions on the expression of recombinant RAP was observed. After recombinant protein was purified with Ni+-nitrilotriacetic acid (Ni+-NTA) affinity chromatogram, its binding ability with microphage was observed. The results showed that two recombinant plasmids both obtained high expression of RAP. The expression levels of RAP in plasmid pT7-PL-RAP in BL21 (DE3, plysS) strain were significantly higher than in BL21 (DE3) strain. The expression of pT7-PL-RAP in the presence of chloramphenicol was higher than in the absence of chloramphenicol, and most of the inducible expressed RAP was soluble. The RAP which was purified by Ni+-NTA resin could strongly bind with the RAW264.7 cells rich in low density lipoprotein receptor (LDLR) family receptors. It was concluded that the expression condition of recombinant RAP was optimized and functional RAP was obtained, which offered a good foundation for the further production of RAP as research tool.
To explore the anti-tumor effect of immunotherapy with recombinant protein vaccine based on FGFR-1 of chicken (cFR-1) in a mouse Meth A fibrosarcoma model, tumor volume and survival rate of the mice were observed at a 3-day interval. Microvessel density (MVD) was detected by immunohistochemistry. Auto-antibodies against self-FGFR-1 were detected by Western blotting and ELISA, respectively. The anti-FGFR-1 antibody-producing B cells (APBCs) were detected by enzyme-linked immunospot (ELISPOT) assay. Eighteen days after inoculation of tumor cells, the tumor volume was significantly smaller in cFR-1-immunized group than in mouse FGFR-1 (mFR-1) immunized group and normal saline (NS) control group (P<0.05), and the survival time was significantly longer in cFR-1-immunized group than in the control groups (P<0.01). MVD was significantly lower in cFR-1-immunized group than in mFR-1-immunized group and NS group (16.8±5.6 vs 64.6±1.8 and 59.6±8.7, P<0.01). Antibodies against self-FGFR-1 were found in mFR-1-immunized group, the major antibody subclasses were IgG1 and IgG2b. Compared with the two control groups, the numbers of APBCs in cFR-1-immunized group were significantly increased (P<0.01) These results demonstrated that the cFR-1-related anti-angiogenesis protein vaccine could induce the production of auto-antibodies against self-FGFR-1, which futher inhibit angiogenesis and growth of solid tumor.
This study examined effect of a new intervertebral cervical disc prosthesis in relieving the neurological symptoms and signs, improving the patients’ ability to perform daily activities, reducing pain, and maintaining the stability and segmental motion. From December 2003 to October 2004, 12 patients, who had received 14 replacements of cervical artificial discs, were followed-up for 2 to 8 months (with a mean of 5.2 months). Of them 5 had cervical spondylotic myelopathy and 7 had cervical disc herniation. The patients included 7 males and 5 females, with their age ranging from 35 to 62 y and a mean of 50.3 y. Single-level replacements were performed in 10 cases and 2 cases received two-level replacement. Operation time of the single-level surgery averaged 130±50 min and the time of two-level surgery was 165±53 min on average (from skin incision to skin suturing). Neurological or vascular complications during or after surgery was not observed. Japanese Orthopedic Association scores (JOA scores) increased from 8.6 to 15.8 on average. There was no prothesis subsidence or excursion. Replaced segments were stable and the range of motion was partially restored, being 4.68° (3.6°–6.1°) in flexion and extension position and 3.51° (2.5°–4.6°), 3.42° (2.6°–4.3°) in left and right bending position. No obvious loss of physiological curvature was noted. CT or MRI follow-up showed that excursion was less than 1.5 mm) in 2 of 14 levels and between 1.5 mm and 3 mm) in 1 of 14 levels. No ossification in the replaced levels was observed. It is concluded that satisfactory short-term results were achieved in the 12 cases of artificial disc replacements. Different from anterior cervical discectomy and fusion, the replacement could achieve quick functional recovery and did not lead to the movement limitation of cervical vertebrae. At least a 5-years follow-up was needed to assess the long-term effect of the prosthesis on its neighboring segments.
Double-stranded oligomeric nucleotide encoding PEP-1 peptides was synthesized, prokaryotic expression pET15b-pep-1-p27mt recombinant constructed, E. coli BL21 (DE3)pLysS transformed and induced with IPTG to highly express fusion protein PEP-1-P27mt. Fusion protein with an N-terminal His-tag could be purified by Ni2+-resin affinity chromatography and identified by SDS-PAGE and Western blotting. Cultured EC9706 cells treated with PEP-1-P27mt revealed that PEP-1-P27mt was transduced into cells after 15 min and reached maximal intracellular concentrations in 2 h. PEP-1-P27mt of 1 μmol/L final concentration could most strongly suppress the growth. It was suggested that PEP-1 can carry P27mt across membrane, which provides a new biological protocol for using cyclin dependent kinase inhibitors p27mt in suppressing the growth of tumor cells.
Human interleukin-15 (IL-15) is a proinflammatory cytokine to suppress neutrophil apoptosis, which is a potential therapeutic agent. The modulatory effect of TNFα was investigated in IL-15-induced suppression of human neutrophil apoptosis. TNFα was shown to reverse the ability of IL-15 to delay neutrophil apoptosis within certain time course. Moreover, this reverse effect by TNFα might be associated with a reduction of the expression of the anti-apoptotic Bcl-Xl protein detected by Western blotting. It is concluded that TNFα can be used to modulate IL-15-induced suppression of neutrophil apoptosis within certain time course.
In order to investigate the pathogenesis of Alzheimer disease (AD) and study the enzymatic progress of amyloid precursor protein (APP), the fluorescent eukaryotic expression plasmid of C99 was constructed containing APP717 mutation. The fragment encoding the last 99-aa of APP (which was named C99 containing APP717 mutation), together with the fragment encoding yellow fluorescence protein (which was named YFP) were amplified by PCR. The two fragments (YFP and C99) were inserted into the vector pcDNA3.0. The recombinant plasmid pcDNA3.0-YFP-C99 was accomplished and its authenticity was confirmed by enzyme digestion and sequencing. Then SH-SY5Y cells were transiently transfected with the recombinant plasmid pcDNA3.0-YFP-C99. The expression of the fusion gene was detected by laser confocalmicroscopy. Amyloid-β (Aβ) was detected by both microscopy and immunochemistry. The authenticity of the construct was confirmed by the endonuclease digestion and DNA sequencing. The YFP fluorescence could be seen and proved the expression of fusion gene. Aβ labeled by YFP was detected by confocalmicroscopy and confirmed by immunocytochemistry. It was found that Aβ accumulated and deposited in the intracytoplasm, membrane and outside of the cell. Furthermore, Aβ accumulated mainly within the cell ahead of the deposition in the cell space and the cell shape was rough. It was suggested that Aβ could be generated within the cells. Aβ accumulated in the cell at the early stage before the deposition outside of the cells. Intracellular Aβ accumulation induced the secondary damage to the cells and caused the cell shape rough. Taken together, the recombinant plasmid, pcDNA3.0-YFP-C99 could be a useful tool to further study the cleavage mechanism of APP and to explore the pathogenesis of AD.
Phosphorylation of β-catenin tyrosine residue 654 plays an important role in the epithelial to myofibroblast transition (EMT). Introducing mimic peptide of tyrosine residue 654 domain of β-catenin into cells may influence phosphorylation of β-catenin tyrosine residue 654. To deliver this mimic peptide into renal epithelial cells, we used penetratin as a vector, which is a novel cell permeable peptide, to deliver hydrophilic molecules into cells. A tyrosine 654 residue domain mimic peptide of β-catenin (PM) with fused penetratin was constructed, purified and then detected for the penetration of the mimic peptide into human renal tubular epithelial cells (HK-2). The results showed that purified fusion mimic peptide could efficiently and rapidly translocate into human renal tubular epithelial cells. It is concluded that a cell-permeable peptides mimic of tyrosine residue 654 domain of β-catenin was successfully obtained, which may provide a useful reagent for interfering the human renal tubular epithelial-mesenchymal transition.