Effect and mechanism of human dental pulp stem cells-derived exosomes on lipopolysaccharide induced acute lung injury / 军事医学

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.

Analysis of T lymphocyte absolute number and function in the early phase after haploidentical hematopoietic stem cell transplantation / 中国实验血液学杂志

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.

Advances of research on autophagy regulation in leukemia cells / 中国实验血液学杂志

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.

Producing recombinant adenovirus encoding green fluorescent protein (Ad-GFP) by suspension cultured HEK-293 N3S cells / 生物工程学报

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.

Effect of intracoronary adenovirus vector encoding hepatocyte growth factor gene on hematopoietic stem cells mobilization in patients with extensive coronary heart disease / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the effect of intracoronary adenovirus vector encoding hepatocyte growth factor gene (Ad(5)-HGF) on hematopoietic stem cells mobilization in patients with extensive coronary heart disease.</p><p><b>METHODS</b>Patients with extensive coronary heart disease were treated with intracoronary infusion of adenovirus vector encoding hepatocyte growth factor (Ad(5)-HGF 5 x 10(9) pfu) gene plus stent implantation (n = 9) or equal physiological saline plus stent implantation (n = 9). Angioplasty and stent implantation was performed according to standard clinical practice by the femoral approach and blood samples were drawn from each patient at baseline before PCI, 6 to 24 hours and 6 days post procedure. The number of CD34(+), CD38(+) and CD117(+) cells in peripheral blood was analyzed by flow cytometer.</p><p><b>RESULTS</b>The number of circulating CD34(+) cells in Ad(5)-HGF gene treatment group 6 hours after procedure and the number of circulating CD117(+) cells 6 days post procedure were significantly higher in Ad(5)-HGF gene treatment group than those in the control group (0.104 +/- 0.082 vs. 0.022 +/- 0.012, P = 0.021) and (0.058 +/- 0.058 vs. 0.012 +/- 0.009, P = 0.034), respectively.</p><p><b>CONCLUSION</b>Intracoronary administration of Ad(5)-HGF could mobilize hematopoietic stem cells into peripheral blood and the consequent role of this observation on myocardial regeneration warrants further detailed studies.</p>

Design and Functional Investigation of a Novel Anti-coagulative Fusion Protein by Hirudin With a Recognizing Sequence of FXa / 中国生物工程杂志

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.

Purification of Recombinant Fusion Protein Staphylokinase-Hirudin Expressed by Escherichia coli and Analysis of its Dimer / 中国生物工程杂志

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.

The induction apoptosis of HL-60 cells by low molecular weight compounds of taurine, ornithine and carnosine from new born calf liver / 中国应用生理学杂志

<p><b>AIM</b>Clinical 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.</p><p><b>METHODS</b>Three 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.</p><p><b>RESULTS</b>These 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.</p><p><b>CONCLUSION</b>The taurine, ornithine and carnosine compounds can selectively suppress tumor cells proliferation by regulating the level of cell cycle proteins.</p>

Construction and expression of a fusion protein made of tissue-type plasminogen activator and hirudin in Pichia pastoris / 生物工程学报

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.

Establishment of a method for determining the sphingosine kinase activity and its initial application / 中国应用生理学杂志

<p><b>AIM</b>To establish the methods for determining the activity of sphingosine kinase(SPK) and the content of sphingosine 1-phosphate (S1P) in biological samples.</p><p><b>METHODS</b>The 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.</p><p><b>RESULTS</b>SPK 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.</p><p><b>CONCLUSION</b>Methods for determining the activity of SPK and the content of SPK in biological samples were established.</p>

Influence of hepatocyte growth factor on biological characteristics of bone marrow-derived mesenchymal stem cells / 中国实验血液学杂志

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.

Study on construction of a plasmid vector carrying human hepatocyte growth factor gene and activity of its expression product / 中国应用生理学杂志

<p><b>AIM</b>To construct a plasmid carrying hepatocyte growth factor gene and investigate its effects in vitro.</p><p><b>METHODS</b>A 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.</p><p><b>RESULTS</b>The 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).</p><p><b>CONCLUSION</b>pUDKH has the potential application in vivo to treat ischemic diseases.</p>

New tactics of human red blood cells stored at 4 degrees C-protective effect of antioxidant solution on red blood cells damage / 中国实验血液学杂志

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.

Studies of protective effect of SOD on damage of human RBCs stored at 4 degrees C / 中国应用生理学杂志

<p><b>AIM</b>To investigate the mechanism of protective effect of SOD (superoxide dismutase) on damage of RBCs stored at 4 degrees C, the studies of erythrocyte glucose and energy metabolism were performed.</p><p><b>METHODS</b>whole blood collected from healthy donors and stored at 4 degrees C in ACD, GMA and SOD solutions. Before and post storage, some parameters were assayed. Standard methods were used for the in vitro tests. The 24-hour in vivo recoveries were measured by FTTC (Fluorescein 5-isothiocyanate) from SIGMA Company.</p><p><b>RESULTS</b>All parameters of red blood cell glucolysis rate without oxygen condition, ATP, PK (pyruvic kinase) and 24 h recoveries level were 86.2%, 56.4%, 64.3% and 86.2% of normal respectively stored in SOD solution at 4 degrees C for 75 days, distinctly more than in ACD and GMA groups at 75 days stored. The 24 h recovery at 75d in group SOD was near the recovery at 42d in group GMA.</p><p><b>CONCLUSION</b>Whole blood in SOD solution can be stored satisfactorily for 75 days at 4 degrees C, and furnished theoretical evidence for RBCs survival.</p>