Hirudin (HV) is known as the most potent and specific inhibitor of thrombin. Although hirudin has many advantages , it has the bleeding side effect and this is the great shortage of hiudin for clinical application. In order to alleviate bleeding side effect of hirudin, fusion protein, named as FHV (fusion hirudin linked with FXa recognition peptide) was designed. The fusion protein gene ( fhv) was cloned into plasmid pPIC9K. FHV engineered Pichia pastoris containing high copies was chosen for fermentation and purification at 30 L fermentor scale, finally, FHV with purity of above 97% was obtained. To investigate the function of FHV in vivo, mouse tail thrombosis model was used. In the mice thrombus tail model induced by carrageenan, FHV decreased the length of tail thrombus significantly, similar to that of HV control, and had no obvious effects on the TT, PT and APTT. In conclusion, FHV is constructed and expressed in yeast. FHV fusion proteins is obtained by fermentation and purification. FHV has antithrombotic effects not influencing IT, PT and APTT after administration immediately in animal models. Therefore, FHV is a promising anticoagulant and antithrombotic drug.

The recombinant fusion protein staphylokinase-hirudin(rSFH) was purified from the high density-fermented engineered E.coli by means of ion-exchange chromatography (IEC) and gel filtration (GF). The purity of rSFH reached to more than 98% determined by RP-HPLC and SDS-PAGE, and the yield was up to 0.7g per liter of fermentation broth. The analysis of homologous dimmer of rSFH appeared during the purification and calculation of the surface hydrophobic area had been carried out by means of hydrophobic chromatography and MALD-TOF. The influence of sodium chloride and temperature on the behavior of rSFH reversible dimerization was analyzed by high performance sized- exclusive chromatography(HPSEC). It is concluded that the hydrophobic interaction played an important role in the reversible dimerization of rSFH.

Autophagy is a conservative self-degradation system in eukaryotic cells, which involves in multiple physiologic and pathologic processes. Autophagosome is a typical characteristics of autophagic process, and its formation and degradation are the key points to control autophagy. Due to its dual characteristics to promote survival and death, to some extent, autophagy determines cell fate for survival or die. Autophagy plays important roles in cancer development, metastasis and drug-resistance. Thus targeting autophagy may provide novel strategies for treating cancer and overcoming drug resistance. With the advances of study on autophagy regulation in leukemia cells, the novel therapeutic targets and strategies to cure leukemia will be developed. This review focuses autophagy characteristics and regulation, autophagy and tumor, autophagy and leukemias as well as autophagy regulation in leukemia cells.
Autophagy ; Humans ; Leukemia ; metabolism ; Signal Transduction

AIMTo construct a plasmid carrying hepatocyte growth factor gene and investigate its effects in vitro.

METHODSA complementary DNA (cDNA) clone for human HGF was isolated from human placental cDNA, then subcloned into pUDK vector, which was constructed by ourselves, to form the pUDKH plasmid. The transfection efficiency and the expression level of HGF and VEGF were evaluated by transfecting pUDK or pUDKH into primary rat skeletal muscle cells. The biological effects of HGF-expressing product at different doses on endothelial cells were investigated in vitro, and assessed by MTT.

RESULTSThe primary rat skeletal muscle cells could be transfected efficiently with pUDKH (0.057%), and secreted HGF(16 -18 ng/4 x 10(5) cells) and VEGF proteins. The expressing product could significantly stimulate proliferation of human umbilical vein endothelial cells, in a dose-dependent manner (P < 0.05).

CONCLUSIONpUDKH has the potential application in vivo to treat ischemic diseases.

Animals ; Cells, Cultured ; DNA, Complementary ; genetics ; Genetic Vectors ; Hepatocyte Growth Factor ; genetics ; metabolism ; Humans ; Plasmids ; Rats ; Rats, Wistar ; Transfection

AIMTo establish the methods for determining the activity of sphingosine kinase(SPK) and the content of sphingosine 1-phosphate (S1P) in biological samples.

METHODSThe ECV304 cells were transfected with pcDNA3 vector encoding Flag-labeled SPK gene. The expression of SPK was measured by Western blot assay and the activity of SPK was determined by enzymatic reaction, isotope incorporation and thin-layer chromatography methods. The S1P in biological samples was extracted, digested by alkaline phosphatase and then catalyzed by SPK. The S1P contents were determined according to the amounts of products.

RESULTSSPK gene transfection could enhance the expression and activity of SPK in cells markedly, and the cellular S1P was also increased obviously. HGF stimulation could increase the activity of SPK and cellular S1P in ECV304 cells.

CONCLUSIONMethods for determining the activity of SPK and the content of SPK in biological samples were established.

Cell Line ; Cytophotometry ; Humans ; Isotope Labeling ; Lysophospholipids ; metabolism ; Phosphotransferases (Alcohol Group Acceptor) ; metabolism ; Sphingosine ; analogs & derivatives ; metabolism

AIMClinical studies stated that low molecular weight compounds (< 1.0 kd) extracted from the new born calf liver could effectively inhibit the proliferation of tumor cells. In this report, we observed inhibition effects and their regulative mechanisms of taurine, ornithine, carnosine on the proliferation of HL-60 cells.

METHODSThree active ingredients, i.e., taurine, ornithine and carnosine were separated by ion-exchange chromatographic column and identified from the low molecular weight filtrate of new born calf liver. MTT assay was used to test the survival rate of HL-60 cells and normal lymphocytes treated by the three ingredients. The various effects of the three compounds on HL-60 cells were respectively evaluated by agarose gel electrophoresis, ESR and immunohistochemical methods.

RESULTSThese compounds effectively inhibited the proliferation of HL-60 cells and induced apoptosis which was determined by apoptotic changes in morphology and nuclear DNA degradation. Whereas no inhibition effects on normal lymphocytes were observed. In addition, the results of ESR showed that the activity of oxygen radical within HL-60 cells treated with there compounds decreased to trace level. Furthermore, in the immunohistochemical experiments, we found that the level of p45/skp2 in HL-60 cells decreased while the level of p27/kip increased.

CONCLUSIONThe taurine, ornithine and carnosine compounds can selectively suppress tumor cells proliferation by regulating the level of cell cycle proteins.

Animals ; Animals, Newborn ; Apoptosis ; drug effects ; Carnosine ; pharmacology ; Cattle ; HL-60 Cells ; Humans ; Liver ; chemistry ; Ornithine ; pharmacology ; Taurine ; pharmacology

To combine the fibrinolytic with anticoagulant activities for therapy of thrombotic deseases, a fusion protein made of tissue-type plasminogen activator (t-PA) and hirudin was constructed and expressed in chia pastoris. To improve thrombolytic properties of t-PA and reduce bleeding side effect of hirudin, FXa-recognition sequence was introduced between t-PA and hirudin molecules.The anticoagulant activity of hirudin can be target-released through cleavage of FXa at thrombus site. t-PA gene and hirudin gene with FXa-recognition sequence at its 5'-terminal were obtained by RT-PCR and PCR respectively. The fusion protein gene was cloned into plasmid pIC9K and electroporated into the genome of Pichia pastoris GS115. The expression of fusion protein was induced by methanol in shaking flask and secreted into the culture medium. Two forms of the fusion protein, single-chain and double-chain linked by a disulfide bond (due to the cleveage of t-PA at Arg275-Ile276), were obtained. The intact fusion protein retained the fibrinolytic activity but lacked any anticoagulant activity. After cleavage by FXa, the fusion protein liberated intact free hirudin to exert its anticoagulant activity. So, the fusion protein is a bifunctional molecule having good prospect to develop into a new targeted therapeutic agent with reduced bleeding side effect for thrombotic diseases.
Animals ; Cloning, Molecular ; Electroporation ; Hirudins ; biosynthesis ; genetics ; Humans ; Pichia ; genetics ; metabolism ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Tissue Plasminogen Activator ; biosynthesis ; genetics

Adenovirus vectors are one of the most promising gene transfer systems. They are of great value for gene therapy because these vectors achieve temporal high-level transgene expression and high gene transfer efficiency. To meet increasing needs of adenovirus vectors for gene therapy programs, parallel development of efficient, scalable and reproducible production processes is required. Perfusion cultivation of 293 cells is one of the most commonly used methods to produce adenovirus vectors and it is suitable for industrialized production specially. Experimental studies had been carried out to produce recombinant adenovirus containing the green fluorescent protein gene (Ad-GFP) by perfusion cultivation of HEK-293 N3S cells in a 5L stirring bioreactors. Perfusion rate was 1-2 volume/day. To infect the 293 N3S cells with Ad-GFP at the density of (2-4) x 10(6) cells/ ml. The time of collecting cells was 48 hours post infection. After three rounds of freeze/thaw and centrifugation, the crude viral lysates were stored at--80 degrees C until use. Then to get the Ad-GFP products by 2 x CsCl-gradient purification. The purity of the products was determined by the A260/A280 ratio and a high performance liquid chromatography (HPLC) assay. The infective titer was determined by a TCID50 assay. The culture term was 10-12 days. The infectious titer, the number of virus particle and the ratio of infectious titer to virus particle for the product were 1.0 x 10(11) IU/mL, 1.68 x 10(12) VP/mL and 6.0% IU/VP respectively. The A260/A280 ratio was 1.33, and the purity determined by HPLC was 99.2%. The cell specific productivity was around 1000 IU/cell. By perfusion cultivation of 293 N3S cells in a 5L stirring bioreactors, we established the production process for Ad-GFP, which paves a way to produce other recombinant adenovirus for gene therapy.
Adenoviridae ; genetics ; growth & development ; isolation & purification ; Bioreactors ; microbiology ; Cell Line ; Gene Transfer Techniques ; Genetic Vectors ; Green Fluorescent Proteins ; genetics ; Humans ; Kidney ; cytology ; virology ; Recombinant Proteins ; biosynthesis ; genetics ; Recombination, Genetic ; Virus Cultivation ; instrumentation ; methods

Aliquots of venous blood from healthy donor were collected in plastic blood storage bags with ACD, GMA or antioxidant solution (superoxide dismutase, SOD), respectively, and stored at 4 degrees C. After storage for varying periods, the parameters of the blood were detected in the blood samples. Results showed that the parameters of the blood stored at 4 degrees C for 75 days in SOD group were following: the recovery of RBC-Hb was 87.2%, plasma-Hb (mg/L) was 193.2, P50 (mmHg) was 34.0 (normal value was 33.1); deformability (DImax) was 0.2413 (74.3% of normal value). There was no evident hemolysis, color change, air bubble and clots. It was concluded that human RBC stored at 4 degrees C for 75 days with SOD solution, recovery of levels of RBC-Hb and plasma-Hb were accorded with the requirements of "Basic Demands of Blood Station" in China.
Antioxidants ; pharmacology ; Blood Preservation ; methods ; Cold Temperature ; Erythrocyte Deformability ; drug effects ; Erythrocytes ; drug effects ; metabolism ; Free Radical Scavengers ; pharmacology ; Hemoglobins ; drug effects ; metabolism ; Humans ; Superoxide Dismutase ; pharmacology ; Time Factors

Hepatocyte growth factor (HGF) is one of major growth factors in the bone marrow microenvironments with which the proliferation, differentiation and migration of bone marrow-derived mesenchymal stem cells were closely contacted. However, its roles in the regulation of proliferation, differentiation and migration of bone marrow-derived mesenchymal stem cells remain unclear. This study was aimed to investigate the effect of HGF on biological characteristics of bone marrow-derived mesenchymal stem cells. Expression of c-Met, the receptor for HGF was detected by immunohistochemistry assay, cell proliferation was determined by MTT, activity of ALP was quantitatively assayed, cell migration and anoikis-induced MSC apoptosis were analyzed. The results showed that HGF not influenced the proliferation and osteogenic differentiation of bone marrow-derived mesenchymal stem cells. Treatment of bone marrow-derived mesenchymal stem cells with recombinant human hepatocyte growth factor resulted in inhibition of anoikis-induced apoptosis. HGF significantly stimulated the migration of bone marrow-derived mesenchymal stem cells. Both PI-3 kinase and MAPK kinase were proved to be involved in HGF-induced migration. It is concluded that HGF/c-Met signal regulates the apoptosis and migration of bone marrow-derived mesenchymal stem cells.
Anoikis ; drug effects ; Bone Marrow Cells ; cytology ; drug effects ; metabolism ; Cell Movement ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Hepatocyte Growth Factor ; pharmacology ; Humans ; Immunohistochemistry ; Mesenchymal Stromal Cells ; cytology ; drug effects ; metabolism ; Proto-Oncogene Proteins c-met ; biosynthesis