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

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

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

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

Objective To investigate the protective role and underlying mechanism of human dental pulp stem cells (DPSCs)-derived exosomes against lipopolysaccharide ( LPS) induced acute lung injury ( ALI) in pulmonary alveolar macrophage(PAM) cells of rats.Methods DPSCs were cultured in the complete culture medium , and their supernatants at passage 6 were collected after serum-free medium treatment for 24 hours.Exosomes were extracted and purified with ultracentrifugation .Rat PAM NR8383 was cultured in 12-well plate and treated with LPS of 1μg/ml alone or together with exosomes.The supernatants were then collected at 0, 6, 12 and 24 h respectively after treatment .Inflammatory cytokine levels of tumor necrosis factor-α(TNF-α)and interleukins (IL-1βand IL-6) in the supernatant were measured by ELISA assay and the expression and phosphorylation level of MAPK (p44/42), NF-κB and IκBαin cell lysates were detected with Western-blotting.Results Compared with control group , the content of TNF-α,IL-1βand IL-6 increased significantly in LPS group (P<0.05), which indicated that the inflammatory cell model was induced successfully .The levels of TNF-αand IL-1βwere obviously attenuated after a high doses of exosomes treatment (P<0.05), and the expression of IL-6 was markedly suppressed after low and high doses of exosomes treatment (P<0.05), compared with the group of LPS treatment alone.The phosphorylation of NF-κB, IκBαand p44/42 was significantly inhibited after treatment with the DPSCs-derived exosomes.Conclusion DPSCs-derived exosomes may have a potential protective effect on LPS-induced ALI, and the underlying mechanism is that the activity of MAPK (p44/42) and NF-κB/IκBαpathways are eliminated by DPSCs-derived exosomes.

This study was purposed to investigate the immune reconstitution of T-cells in patients who received haploidentical hematopoietic stem cell transplantation (hiHSCT). The peripheral blood was harvested from 22 patients before transplantation and at month 1, 3, 6 after hiHSCT. The proportions of T lymphocyte subtypes including CD3(+), CD4(+), CD8(+), CD45RO(+), and CD45RA(+)CD62L(+) were analyzed by flow cytometry, followed by the calculation of T cell numbers according to the amounts of peripheral blood leukocytes. Adenosine triphosphate (ATP) value in CD4(+) T cells was measured by ImmuKnow method to evaluate the function of lymphocytes. The results showed that the CD3(+) cell absolute value before transplantation was 833.75 ± 359.84/µl, but those values at month 1, 3, 6 after transplantation were 318.87 ± 266.71/µl, 1006.76 ± 512.32/µl and 1296.38 ± 958.77/µl respectively. The CD4(+) cell absolute value before transplantation was 336.99 ± 211.11/µl, but such values at month 1, 3, 6 after transplantation were 45.89 ± 44.21/µl, 142.97 ± 114.85/µl, and 181.78 ± 120.61/µl respectively. The CD8(+) cell absolute value before transplantation was 430.21 ± 159.48/µl, but those values at month 1, 3, 6 after transplantation were 230.44 ± 195.89/µl, 621.64 ± 318.83/µl, and 823.07 ± 633.55/µl respectively. The CD4(+)CD45RO(+) memory T cell absolute value before transplantation was 227.44 ± 73.34/µl, but such values at month 1, 3, 6 after transplantation were 43.47 ± 43.40/µl, 138.69 ± 110.17/µl, 147.73 ± 82.94/µl respectively. The CD8(+)CD45RO(+) memory T cell absolute value before transplantation was 212.70 ± 98.48/µl, but such values at month 1, 3, 6 after transplantation were 184.76 ± 168.65/µl, 445.90 ± 252.50/µl, 519.80 ± 475.53/µl respectively. CD4(+)CD45RA(+)CD62L(+) naive T cell number before transplantation was 68.94 ± 59.74/µl, but such cell numbers at month 1, 3, 6 after transplantation decreased to 2.44 ± 2.93/µl, 3.14 ± 3.48/µl, 23.22 ± 38.38/µl respectively. The CD8(+)CD45RA(+)CD62L(+) naive T cell absolute value before transplantation was 124.82 ± 60.95/µl, but those values at month 1, 3, 6 decreased to 19.37 ± 17.71/µl, 76.63 ± 50.85/µl, and 114.49 ± 174.29/µl respectively. The ATP value in CD4(+) T cells decreased to 210.19 ± 119.37 ng/ml at month 1 after transplantation and increased to 280.62 ± 110.03 ng/ml at month 3, and 357.28 ± 76.18 ng/ml at month 6 after transplantation. It is concluded that CD8(+) memory T cell reconstruction contributes critically to T cell recovery early after hiHSCT, while the thymic output function remains low. However, T cell function recovers to normal range at month 3 after transplantation.
Adolescent ; Adult ; CD8-Positive T-Lymphocytes ; cytology ; Child ; Child, Preschool ; Female ; Haplotypes ; Hematopoietic Stem Cell Transplantation ; Humans ; Immunophenotyping ; Killer Cells, Natural ; immunology ; Lymphocyte Count ; Male ; T-Lymphocyte Subsets ; immunology ; Young Adult