Objective To develop an interleukin-4(IL-4) antagonist named M5-IgG1Fc protein constructed by genetic engineering of antibody Fc fragment-cytokine mutein fusion protein which has a long half-life time in plasma.M5-IgG1 Fc protein binds to IL-4 receptor but cannot activate downstream signalling pathway , which provides a basis for drug develop-ment for allergic diseases .Methods The synthesized interleukin-4 mutant gene ( named M5 ) was cloned into the expres-sion vector pBV220 and transformed into E.coli DH5α.Chimeric gene M5-IgG1Fc obtained by overlap extension (SOE) method was transformed into glycoengineered Pichia pastoris GJK01 through expression vector pPICZαA .Then M5-IgGFc fusion protein was obtained by protein purification after being induced by methanol in 72 hours.The anti-IL-4 biologicial ac-tivity assay of M5 and M5-IgG1 Fc was performed with CTLL-2/IL-4R cells and detected with MTT colormetry .Finally,the half-life time of M5 and M5-IgG1 Fc protein in mice was compared by detecting the remaining amount in plasma with ELISA kit.Results The M5 protein expressed in E.coli and M5-IgG1 Fc fusion protein expressed in P.pastoris GJK01 both had IL-4 antagonistic bioactivity .The EC50 of both, which inhibited 5.6 ×10 -2 nmol/ml of IL-4, were 0.31 ±0.05 and 0.77 ± 0.03 nmol/ml,respectively.The maximum of M5 in plasma at 0.5 h was 5.8 ×10 -2 nmol/ml but the remaining amount was 2.8%of the maximum at 2 h.M5 protein could not be detected after administration at 8 h because of the detection line . The maximum of M5-IgG1 Fc fusion protein was 4.7 ×10 -2 nmol/ml,while fusion protein M5-IgG1 Fc decreased to 4.3%of its maximum at 120 h and could not be detected at 168 h.Conclusion M5 protein has IL-4 antagonistic bioactivity .M5-IgG1 Fc fusion protein expressed in glycoengineered P.pastoris GJK01 has IL-4 antagonistic bioactivity and long retention time in mice,which can be potentially used for treatment of allergic diseases .

BACKGROUND:Porous poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/calcium metaphosphate composite membranes prepared previously is too thick and uneven in holes.
OBJECTIVE:To prepare the thin even porous poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/calcium metaphosphate composite membrane, and to evaluate the cytocompatibility and differentiation capacity.
METHODS:Porous and nonporous, thin and even poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/calcium metaphosphate composite membranes were prepared by phase separation method. Its thickness and weight loss rate were determined. Human bone marrow mesenchymal stem cel s were cocultured with porous and nonporous poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/calcium metaphosphate composite membranes for 7 days. Ultrastructure of composite membranes was observed under the scanning electron microscopy. Surface markers of the bone marrow mesenchymal stem cel s on the composite membranes were analyzed using flow cytometry.
RESULTS AND CONCLUSION:The thickness of the porous and nonporous composite membranes was (0.041 ± 0.005) mm and (0.058±0.004) mm. Weight loss rates of porous and nonporous composite membranes were respectively 19.93%and 7.64%at 24 hours. Calcium metaphosphate particles were evenly distributed in porous and nonporous composite membrane. Cel s spread entirely, showing spindle shape. Calcium metaphosphate particles were evenly distributed in porous composite membrane. Pore in porous composite membranes was also uniformly distributed, and pore size was about 2-8μm. Cel s spread entirely, showing polygonal shape with multiple tentacles. The tentacles of some cel s entered into the scaffold. CD105, CD90, CD44, CD29 and CD73 expression was detected in porous and nonporous composite membranes. There was no significant difference in cel-positive rate. Poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/calcium metaphosphate composite membranes prepared in this study has good biocompatibility and could not promote cel differentiation.

Aim To explore the anti-apoptotic function of cardiac progenitor cells(CPCs)-derived exosome in vitro.Method CPCs were isolated from mouse heart using Magnetic Cell Sorting(MACS)system.Flow Cy-tometry(FC)determine the purity of stem cell surface antigen-1 positive(Sca-1 +)CPCs.Exosome was puri-fied from conditional medium,and confirmed by West-ern blot using CD63 as a marker,Nanoparticle Traffic-king Analysis(NTA)was used to detect the diameters and concentration of exosome.Then the cells were di-vided into control groups and CPC-exosome pre-protec-tion groups.H2 O2 was added into H9c2 cells to induce oxidative stress.Western blot was adopted to determine the expression of cleaved caspase-3.Results ① Im-munofluorescence showed that CPCs isolated by MACS were positively expressing Sca-1 protein;FC analysis showed that typical purity of Sca-1 +CPCs from the first
preparations was more than 95%.② WB demonstrated that CD63 of exosome isolated from CCMwas positively expressed,and NTA results showed that the diameters of exosome were (82.33 ±3.06)nm(n =3).Micro-scope detected PKH-26 labeled exosome appeared in the cytoplasma of H9c2 cells.③ Western blot showed the CPC-exosome pre-protection groups significantly down-regulated the levels of cleaved caspase-3 com-pared to the control groups(P <0.05).Conclusion CPC can secrete exosome which carries many important cargos,which can effectively gather in H9c2 cells. CPC-exosome can protect H9c2 cells from the oxidative stress induced by H2 O2 .Our results highlight a new perspective strategy for cardiac disease.

[ ABSTRACT] AIM:To investigate the role of encapsulated protein transfected into human bone marrow mesen-chymal stem cells ( hBMSCs) by polyethyleneimine ( PEI) , and to optimize the best mole ratio of PEI-proteins.METH-ODS:6 groups of DNase I-PEI complexes were constructed and the best mole ratio was explored by laser scattering analy-sis.The appearance of complexes was presented under transmission electron microscope.Meanwhile, 4 groups of construc-ted GFP-PEI complexes were utilized to transfect into the hBMSCs, which were isolated and expand in vitro.The fluores-cence intensity of transfected cells was observed under confocal microscope.In addition, the cytotoxicity of the complexes on the cell proliferation was detected by MTT assay.The activity of the intracellular proteins was testified by aβ-galactosi-dase staining experiment.RESULTS:When the mole ratio of PEI and protein was adjusted to 4∶1, the complex transfec-tion efficiency was the best, and β-galactosidase color test turned blue.CONCLUSION:PEI has the character of encap-sulating various proteins to nano-complexes.The proteins transfected into bone marrow mesenchymal stem cells are con-firmed to have functional activity.As a protein carrier, PEI is of high efficiency and low toxicity, thus providing a new way for stem cell reprogramming.

Objective To prepare endo-beta-N-acetylglucosaminidase H (Endo-H) expressed in Pichia pastoris, and apply it to N-glycosylation analysis .Methods One complete gene was synthesized on the basis of the cDNA sequence encoding Streptomyces plicatus reported in GenBank .The gene was cloned into the expression vector pPIC 9.The expression vector pPIC9-Endo-H was transformed into P.pastoris(JC308).The expression products were induced by methanol , puri-fied by two-step chromatography , used to analyze the glycan structures of RNaseB by the DNA sequencer assisted fluoro-phore-assisted carbohydrate electrophoresis (DSA-FACE)methods, and finally compared with peptide-N-asparagine amidase F(PNGase F).Results This enzyme expressed in P.pastoris(JC308) had the ability to hydrolyze natural or denatured high-mannose type of oligosaccharide linked by β-1,4-glycosidic bonds , but not complex-type oligosaccharide .The result of DSA-FACE showed that carbohydrate chains of Man 5 GlcNAc-Man9 GlcNAc could be obtained when RNaseB was hydrolyzed by Endo-H, and that Man5 GlcNAc2-Man9 GlcNAc2 chains became available when RNaseB was hydrolyzed by PNGase F . Conclusion Endo-H expressed in P.pastoris has bioactivity which can be used to analyze N-glycosylation with the method of DSA-FACE.

Objective To obtain a strain of glycoengineering yeast with higher N-glycosylation efficiency by overexpressing N-glycosyltransferase.Methods Through the selecting marker URA3 gene, a new glycoengineering yeast strain named 4-32-STT3D was constructed, which could overexpress the Leishmania major N-glycosyltransferase staurosporine and temperature sensitivity3 D subunit(STT3D) under the control of an inducible alcohol oxidase 1(AOX1) promoter.We analyzed the N-glycosylation status of anti-human epidermal growth factor receptor 2 ( HER2 ) antibody and granulocyte macrophage colony stimulating factor (GM-CSF) expressed in 4-32-STT3D using SDS-PAGE,Western blotting and peptide-N-asparigineamidase F(PNGase F).Finally the effect of STT3D on the growth rate of glycoengineering yeast was detected.Results SDS-PAGE showed that anti-HER2 antibody expressed in 4-32-HL had two components:the first one with a relative molecular mass 55 ×103 was glycosylated,while the second one with 50 ×103 was non-glycosylated,but anti-HER2 antibody expressed in 4-32-HL-STT3D had the component of 55 ×103 only without any non-glycosylated 50 ×103 .The above components became 50 ×103 with the digestion of PNGaseF.All of them proved to be antibodies by Western blotting.As a report protein,GM-CSF expressed in 4-32-GM-CSF had two components: 22 ×103 and 20 ×103, while in 4-32-GM-CSF-STT3D there was only one with 22 ×103 .All these components became 18 ×103 with the digestion of PNGase F.Statistical analysis showed that without induction,STT3D had no effect on the growth rate of glycoengineering yeast, while great effect was observed when STT3D was induced.Conclusion Glycoengineering yeast with the overexpression of N-glycosyltransferase has higher N-glycosylation efficiency.

BACKGROUND:Calcium metaphosphate has excel ent biocompatibility, degradability, and cel affinity. Human bone marrow mesenchymal stem cel s can grow and proliferate in the pores of the porous calcium metaphosphate, but less is known about calcium metaphosphate nanoparticles.
OBJECTIVE:To prepare calcium metaphosphate nanoparticles, and to analyze the effect of calcium metaphosphate nanoparticles at different concentrations on apoptosis of human bone marrow mesenchymal stem cel s by flow cytometry.
METHODS:The calcium metaphosphate nanoparticles were prepared by wet bal mil ing. Scanning electron microscopy and transmission electron microscopy were used to observe the morphology of the calcium metaphosphate nanoparticles, and the crystal structure of nanoparticles was analyzed by X-ray diffraction. Calcium metaphosphate nanoparticles were mixed in the CYAGON Oricel TM basal medium, and the concentrations of calcium metaphosphate nanoparticles in the medium were 10, 1, 0.1 mg/L. Human bone marrow mesenchymal stem cel s were cultured for 7 days in the above-mentioned media, and apoptosis of human bone marrow mesenchymal stem cel s was analyzed by flow cytometry.
RESULTS AND CONCLUSION:Calcium metaphosphate nanoparticles were successful y prepared by wet bal mil ing, irregular in shape, and the mean diameter was 10-30 nm. X-ray diffraction results showed the crystal structure of nonaparticles was mainlyβ-Ca(PO3)2. The cel ratio of G0/G1 phase and G2/M phase in 10 mg/L group was obviously higher than that in 1, 0.1 mg/L groups (P<0.01). The cel apoptosis rates during the early, middle, late stages in 10 mg/L group were obviously higher than those in 1, 0.1 mg/L groups (P<0.01), and the total cel apoptosis was also significantly increased in 10 mg/L group (P<0.01). These findings indicate that human bone marrow mesenchymal stem cel s proliferation can be inhibited by calcium metaphosphate nanoparticles, and apoptosis rate is increased significantly when the concentration of calcium metaphosphate nanoparticles increases from 1 mg/L to 10 mg/L.

Aim To investigate whether human umbili-cal cord mesenchymal stem cells(hUC-MSCs)exposed to inflammatory conditions could release large amounts of exosomes to induce regulatory T cells(Treg).Meth-ods hUC-MSCs were isolated by enzyme digestion method.(In vitro)interferonγ(IFN-γ)was added in-to hUC-MSCs to mimic inflammatory microenviron-ments,then exosomes were extracted from the superna-tant of normal conditional medium or IFN-γpretreated hUC-MSCs.Both sources of exosomes,Nor-hUC-exo and IFN-γ-stimulated hUC-exo, were identified by Nanoparticle Trafficking Analysis (NTA )and Western blot for the exosome-enriched protein CD63 .Next,hu-man peripheral blood mononuclear cells (PBMCs ) stimulated with PHA were respectively co-cultured with hUC-MSCs,IFN-γ-pretreated-hUC-MSCs,hUC-MSCs exosomes or IFN-γ-stimulated-hUC-MSCs exosomes for 5 days to assess the exosomes-T cells communication. The proliferation rate of PBMCs and frequency of CD4 +/CD25 +/Foxp3 + Treg were measured by flow cytometry.Results The isolated cells from human um-bilical cord tissue,which were positive for CD73, CD44,CD29,CD90 and HLA-ABC,but were nega-tive for CD31 and CD34,were mesenchymal stem cells indeed.After IFN-γtreatment,hUC-MSCs secreted nu-merous exosomes(P<0.05 ).Morerover,there was a significantly higher level of CD63 ,but no difference in diameter between Nor-hUC-exo and IFN-γ-stimulated hUC-exo.IFN-γ-stimulated hUC-exo had a superior a-bility compared with Nor-hUC-exo to suppress the pro-liferation of PHA stimulated PBMCs due to their upreg-ulation of the percentage of Treg (1 1.53 ±0.88% vs 6.60 ±0.56%,P <0.01 ).Conclusion hUC-MSCs could promote the expression of Treg to modulate im-munosuppression through exosomes,especially for IFN-γ-licenced exosomes,which might carry much immu-notherapeutic potential.

AIM: To screen and identify the differentially expressed genes in lymphocytes of patients with unstable angina in order to find the molecular mechanism of unstable angina. METHODS: Suppression subtractive hybridizations (SSH) and dot blot hybridizations were performed to screen the relatively differentially expressed genes in lymphocyte RNA between the patients with unstable angina pectoris and stable angina pectoris. The obtained expressed sequence tags (ESTs) were used as probes to perform Reverse Northern blot with forward and reverse suppression products. And the positive ESTs were performed RNA slot hybridization with unstable and stable angina group. The obtained ESTs were sequenced and analyzed using BLAST (nr) at NCBI. RESULTS: Three up-regulated ESTs in the unstable angina group, and one down-regulated EST in the stable angina group were obtained. All of them are sequences of known genes. CONCLUSION: All these ESTs may be associated with the unstablization of plaque of coronary artery in patients with unstable angina.

AIM:Increasing evidence indicates that inflammation contributes to the initiation and perpetuation of atrial fibrillation ( AF) .Al-though tumor necrosis factor ( TNF)-αlevels are increased in patients with AF , the role of TNF-αin the pathogenesis of AF remains unclear.Recent research has revealed that T-type Ca2+currents ( ICa,T ) play an important role in the pathogenesis of AF .METH-ODS:In this study , we used the whole-cell voltage-clamp technique and biochemical assays to explore the role of TNF-αin the regula-tion of ICa,T in atrial myocytes.RESULTS:We found that compared with sinus rhythm (SR) controls, T-type calcium channel (TCC) subunit mRNA levels were decreased , while TNF-αexpression levels were increased , in human atrial tissue from patients with AF .In murine atrial myocyte HL-1 cells, after cultured for 24 h, 12.5, 25 and 50 μg/L TNF-αsignificantly reduced the protein expression levels of the TCC α1G subunit in a concentration-dependent manner .The peak current was reduced by the application of 12.5 or 25μg/L TNF-αin a concentration-dependent manner [from ( -15.08 ±1.11) pA/pF in controls to ( -11.89 ±0.83) pA/pF and (-8.54 ±1.55) pA/pF in 12.5 and 25 μg/L TNF-αgroups, respectively].TNF-αapplication also inhibited voltage-dependent inactivation of ICa,T shifted the inactivation curve to the left .CONCLUSION:These results suggest that TNF-αis involved in the path-ogenesis of AF, probably via decreasing ICa,T function in atrium-derived myocytes through impaired channel function and down -regula-tion of channel protein expression .This pathway thus represents a potential pathogenic mechanism in AF .