OBJECTIVETo study the purification, refolding and bioactivity of streptavidin-tagged human tumor necrosis factor-alpha (SA-TNF-alpha) bi-functional fusion protein.

METHODSSA-TNF-alpha fusion protein was expressed in BL21(DE3) host bacteria, purified using Ni-NTA affinity chromatography and refolded by dilution and dialysis followed by identification using Western blotting. The effect of SA-TNF-alpha fusion protein against L929 cells was evaluated by MTT assay. Flow cytometry was used to analyze the surface modification of biotinylated MB49 tumor cells by SA-TNF-alpha fusion protein.

RESULTSRecombinant SA- TNF-alpha fusion protein was expressed in BL21(DE3) at about 30% of total bacterial protein, with a purity of about 95% after purification. The SA-TNF-alpha fusion protein existed as dimmers, tetramers and higher order structures after refolding. The fusion protein exhibited a bi-functionality by inhibiting L929 cells and SA-mediated high-affinity binding to biotinylated cell surfaces, with an anchor modification rate of above 90%.

CONCLUSIONThe dimmers, tetramers and higher order structures of the obtained SA-TNF-alpha fusion protein all exhibit a bi-functionality, and may serve as a potential candidate therapeutic agent for tumors.

Chromatography, Affinity ; methods ; Escherichia coli ; genetics ; metabolism ; Humans ; Nickel ; Protein Folding ; Recombinant Fusion Proteins ; biosynthesis ; chemistry ; genetics ; isolation & purification ; Streptavidin ; biosynthesis ; genetics ; Tumor Necrosis Factor-alpha ; biosynthesis ; genetics

This paper is aimed to present a research on fusion protein of human tumor necrosis factor-alpha (hTNF-alpha), matrix metalloproteinase 1 (MMP1), and foldon sequence using the methord of gene engineering. We transformed the recombinant plasmid, which contains the DNA sequences of hTNF-alpha, MMP1, and foldon sequence, into Rosetta2, and successfully induced the fusion protein to express under given conditions by isopropyl beta-D-1-Thiogalactopyranoside (IPTG). Then we purified the expression product through a glutathione S-transferase (GST) resin and collected the interested protein. This research may lay the groundwork for scientific research and clinical application.
Base Sequence ; Escherichia coli ; genetics ; metabolism ; Humans ; Matrix Metalloproteinase 1 ; biosynthesis ; genetics ; Molecular Sequence Data ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Tumor Necrosis Factor-alpha ; biosynthesis ; genetics

In order to investigate the effects of LPS on the TACE gene transcription and expression and its regulating effect on the TM-TNF secretion, in vitro studies were carried out on HL-60 cells stimulated by LPS. TACE, TNF-alpha mRNA levels were detected by Dot-Elisa and the distribution of membrane molecules determined by flow cytometry assay and indirect immunofluorescence. The results showed that: (1) TACE was detected in or on HL-60 cells and it is predominantly localized on cell surface and to a perinuclear compartment. (2) LPS induced a time dependent increasement of TNF-alpha mRNA and enhanced TNF conversion with decreasing distribution of TNF in cell surface and increasing secretion of TNF protein. Such conversion could be inhibited by TACE ODN. (3) LPS also induced time-dependently increased expression of TACE gene and activation of its function. On the other hand, TACE protein in cell lysate and on cell surface was decreased. It was suggested that TACE molecular structure might change following its mediating membrane-anchored molecular secretion.
ADAM Proteins ; ADAM17 Protein ; Gene Expression ; HL-60 Cells ; Humans ; Lipopolysaccharides ; pharmacology ; Metalloendopeptidases ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Transcription, Genetic ; Tumor Necrosis Factor-alpha ; biosynthesis ; genetics

Animals ; Interleukin-1 ; biosynthesis ; genetics ; Liver ; blood supply ; Lung ; metabolism ; Male ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Rats, Wistar ; Reperfusion Injury ; metabolism ; Tumor Necrosis Factor-alpha ; biosynthesis ; genetics

OBJECTIVETo study the effects of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] on the expression of osteoprotegerin (OPG) and receptor activator of NF-kappaB ligand (RANKL) mRNA in mouse osteoblasts.

METHODSCalvariae derived from CD-1 neonatal mouse (after born 24 h). Bone samples were processed by the collagenase/trypsin digestion method. Mouse osteoblasts were cultured in vitro. After 48 hours of addition of 1,25(OH)2D3 (0, 10(-8), 10(-9), 10(-11) mol/L) to the culture medium of mouse osteoblasts, the content of the OPG protein in culture medium was estimated with enzyme linked immunosorbent assay. Total RNA was prepared from mouse osteoblasts. mRNA expression of OPG and RANKL were detected by reverse transcription-polymerase chain reaction.

RESULTSThe mRNA expression of OPG in osteoblasts added with 1,25(OH)2D3 significantly decreased compared with the controls, which was markedly dose-dependent. OPG protein production in the medium decreased after treatment with 1,25(OH)2D3. In contrast, RANKL mRNA expression levels in osteoblasts significantly increased after 48 h of culture with 1,25(OH)2D3.

CONCLUSION1,25 (OH)2D3 can stimulate RANKL mRNA expression, but decrease OPG mRNA levels in vitro in mouse osteoblasts.

Animals ; Animals, Newborn ; Calcitriol ; pharmacology ; Carrier Proteins ; biosynthesis ; genetics ; Glycoproteins ; biosynthesis ; genetics ; physiology ; Ligands ; Membrane Glycoproteins ; biosynthesis ; genetics ; Mice ; NF-kappa B ; biosynthesis ; genetics ; Osteoclasts ; metabolism ; physiology ; Osteoprotegerin ; RANK Ligand ; RNA, Messenger ; biosynthesis ; genetics ; Receptor Activator of Nuclear Factor-kappa B ; Receptors, Cytoplasmic and Nuclear ; analysis ; biosynthesis ; genetics ; physiology ; Receptors, Tumor Necrosis Factor ; biosynthesis ; genetics ; Tumor Necrosis Factor-alpha ; biosynthesis ; genetics

In order to get soluble TNF receptor (sTNFR) II with good neutralizing activity against TNFalpha, we constructed the fusion gene sTNFRII-gAD, which encoded human sTNFR II and the globular domain of adiponectin (gAD), and then expressed it in mammalian cells and analyzed its anti-TNFalpha activity. First, sTNFRII cDNA was obtained by RT-PCR from the total RNA of human peripheral blood lymphocytes, and fused in frame with gAD gene. Then, the fusion gene sTNFRII-gAD was cloned into the expression vector pAAV2neo to result in the plasmid pAAV2neo-sTNFRII-gAD. By immunofluorescent staining with monoclonal antibody either against TNFRII or against adiponectin, we demonstrated that the pAAV2neo-s7NFRII-gAD-transiently-transfected BHK-21S cells were positive. To obtain G418-resistant BHK-21S/pAAV2neo-sTNFRII-gAD cells, we cultured the transfected BHK-21S cells above in 10% FBS containing DMEM media with 800 microg/mL G418 for 15 days, and changed the serum-containing culture media to a serum-free chemically defined media so as to change the cells culturing style from adhesion to suspension. 24 hours later, we harvested the supernatant of the culture for sTNFRII-gAD fusion protein characterization and anti-TNFalpha activity analysis. With monoclonal antibody either against TNFRII or against adiponectin, the Western blotting analysis showed that the sTNFRII-gAD fusion protein was expressed and existed as monomer, trimer and multimer forms in the supernatant. The bioactivity assay demonstrated that the sTNFRII-gAD fusion protein had the ability to neutralize TNFalpha so as to inhibit the cytotoxicity of TNFalpha on L929 cells. Put together, this study has laid the groundwork for large-scale preparation of sTNFRII-gAD fusion protein.
Adiponectin ; biosynthesis ; genetics ; Animals ; Cells, Cultured ; Cricetinae ; Humans ; Protein Structure, Tertiary ; genetics ; Receptors, Tumor Necrosis Factor, Type II ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; pharmacology ; Solubility ; Tumor Necrosis Factor-alpha ; antagonists & inhibitors

OBJECTIVETo compare the expressions of transforming growth factor alpha (TGFalpha), tumor necrosis factor alpha (TNFalpha), and vascular endothelial growth factor (VEGF) between pheochromocytoma (PHEO) tissues and normal adrenal medulla tissues.

METHODSThe mRNA expressions of TGFalpha, TNFalpha, and VEGF detected by RT-PCR, were compared between 22 PHEO tissues and 18 normal adrenal medulla tissues (according with the principle of medical ethnics). Immunohistochemistry staining was performed on 27 PHEO tissues and 14 normal adrenal medulla tissues. The comparisons of the protein expression of TGFalpha, TNFalpha, and VEGF were analyzed in both of PHEO tissues and normal adrenal medulla tissues.

RESULTSCompared with normal adrenal medulla tissues, the expressions of TGFalpha and TNFalpha mRNA and protein were higher in PHEO tissues, and VEGF145 mRNA expression was also higher in PHEO tissues, while there was no significant difference of the mRNA expression of VEGF121 and VEGF165 between these two tissues. Positive staining rates for VEGF of endothelial cells and tumor cells were higher in PHEO tissues than in normal adrenal medulla tissues. Expressions of the TGFalpha, TNFalpha, and VEGF protein were higher in extra-adrenal PHEO than in adrenal PHEO. The TNFalpha immunohistochemistry staining rate was higher in the malignant or multiple PHEO than in the benign or single PHEO.

CONCLUSIONSThe mRNA and protein expressions of TGFalpha, TNFalpha, and VEGF are higher in PHEO tissues than those in normal adrenal medulla tissues. Expressions of these cytokines vary in PHEO with different characteristic.

Adrenal Gland Neoplasms ; metabolism ; Adrenal Medulla ; metabolism ; Humans ; Pheochromocytoma ; metabolism ; RNA, Messenger ; biosynthesis ; genetics ; Transforming Growth Factor alpha ; biosynthesis ; genetics ; Tumor Necrosis Factor-alpha ; biosynthesis ; genetics ; Vascular Endothelial Growth Factors ; biosynthesis ; genetics

OBJECTIVETo investigate the protective effects and mechanism of artesunate (AR) on the activation and injury of human umbilical vein endothelial cells (HUVECs) induced by lipopolysaccharide (LPS).

METHODSAfter HUVECs were cultured and turned to fusion manner, LPS and different concentration of AR (0.04 mg/L, 0.2 mg/L, 1 mg/L, 5 mg/L and 20 mg/L) were added respectively and co-incubated for 24 hrs. The expression of von Willebrand factor (vWF) in the conditioned media was tested by ELISA, the expression of intercellular adhesion molecule (ICAM-1) protein was determined by Western blot method and the expression of tumor necrosis factor alpha (TNFalpha) mRNA was determined by in situ hybridization.

RESULTSAfter being exposed to 1 microg/ml LPS, vWF and ICAM-1 expression were higher than those in the control group. AR could significantly down-regulate the increased expressions concentration-dependently, significant difference showed as the concentration of AR reached 1 mg/L (P < 0.05). In situ hybridization showed that AR in 0.2 mg/L and 1 mg/L could markedly down-regulate the TNFalpha mRNA expression, showing significant difference as compared with that in LPS group (P < 0.05, P < 0.01).

CONCLUSIONAR has protective effect on LPS induced HUVECs activation and injury, which might be related with its inhibition on TNFalpha mRNA expression.

Artemisia ; chemistry ; Artemisinins ; pharmacology ; Cells, Cultured ; Endothelium, Vascular ; drug effects ; metabolism ; pathology ; Humans ; Intercellular Adhesion Molecule-1 ; biosynthesis ; genetics ; Lipopolysaccharides ; RNA, Messenger ; biosynthesis ; genetics ; Sesquiterpenes ; pharmacology ; Tumor Necrosis Factor-alpha ; biosynthesis ; genetics ; Umbilical Veins ; pathology ; von Willebrand Factor ; biosynthesis ; genetics

AIMTo study the effects of TNF receptor blocking peptide on adjuvant arthritis in rats.

METHODSThe model of rat adjuvant arthritis was induced by injection of complete Freund's adjuvant. The TNF receptor blocking peptide was injected locally in the ankle. The ankle swelling, the pathologic changes in the ankle joint and the expression of IL-1 beta mRNA and TNF-alpha mRNA by peritoneal macrophages (RT-PCR) were observed.

RESULTSThe model of rat adjuvant arthritis induced by injection of complete Freund's adjuvant was similar to human rheumatoid arthritis. The treatment with TNF receptor blocking peptide for 10 days resulted in complete inhibition of joint swelling, a decrease in infiltration of inflammatory cell into joint tissue, an obvious alleviation of inflammatory pathological damages and an apparent decline of TNF-alpha mRNA and IL-1 beta mRNA of peritoneal macrophages of rats.

CONCLUSIONThe TNF receptor blocking peptide can protect the joint from inflammatory damage induced by adjuvant arthritis by suppression of TNF-alpha and IL-1 production, thereby alleviating the pathological injury of joint and controlling effectively the clinic course of arthritis.

Animals ; Ankle Joint ; pathology ; Arthritis, Experimental ; immunology ; pathology ; Interleukin-1 ; biosynthesis ; genetics ; Macrophages, Peritoneal ; metabolism ; Male ; Peptides ; pharmacology ; RNA, Messenger ; genetics ; Rats ; Rats, Wistar ; Receptors, Tumor Necrosis Factor ; antagonists & inhibitors ; Tumor Necrosis Factor-alpha ; biosynthesis ; genetics

Metabolic engineering provide powerful tools for the systematic manipulation of cellular metabolic activities. The ptsG gene for glucose-specific transporter Enzyme II CBGlc of the phosphotransferase system was knock-out so as to reduce the accumulation of acetic acid in the high cell-density culture of Escherichia coli on excess glucose. The chloramphenicol-resistant cassette with short shared sequences on both ends generated by PCR was electroporated into Escherichia coli DH5alpha and JM109. Recombination between linear DNA cassettes and Escherichia coli chromosomes took place by Red recombinase functions. Therefore, the ptsG gene was disrupted to construct the mutants called DH5alphaP and JM109P. There was no difference between the mutants and parent strains in LB media.However, in LB media supplemented with glucose, the mutants of Escherichia coli deficient in ptsG showed greater biomass, together with exploiting more glucose. The maximal cell density obtained with DH5alphaP was approximately 3 times more than that of DH5alpha, then the result of JM109P increased fourfold. The products of recombinant protein TNF respectively accounted for 24.3% of total cellular protein in DH5alphaP with A600 8.28 and 20.8% of total cellular protein in JM109P with A600 7.62. The specific volume expression amount of TNF was greater in the ptsG mutant than in its parent strain. These results demonstrate that the ptsG-mutant strains will be available for high cell-density culture.
Culture Media ; Escherichia coli ; genetics ; growth & development ; Fermentation ; Mutation ; Phosphoenolpyruvate Sugar Phosphotransferase System ; genetics ; Polymerase Chain Reaction ; Recombinant Proteins ; biosynthesis ; Tumor Necrosis Factor-alpha ; biosynthesis