This study is designed to obtain recombinant human acetylcholinesterase (rhAChE) and apply it in screening acetylcholinesterase inhibitors. The rhAChE was overexpressed in HEK293 cells transfected by plasmid of pCMV-AChE with the cationic liposome and rhAChE was found to be secreted into cell culture medium. AChE activity was assayed according to modified Ellman method to obtain kinetic parameters. IC so50 values for donepezil compounds of rhAChE were calculated to determine their activities of inhibition. The results showed that Km value was 151.9 micromol.L-1 donepezil inhibited rhAChE in a mixed competitive-noncompetitive way (Ki= 16.03 nmol.L-1, Ki = 18.36 nmol.L-1) and that most new compounds tested exhibited high activities of inhibition on rhAChE. The study suggests that rhAChE is available to be applied in screening AChE inhibitors in vitro.
Acetylcholinesterase ; genetics ; metabolism ; Cholinesterase Inhibitors ; analysis ; pharmacology ; HEK293 Cells ; Humans ; Indans ; analysis ; pharmacology ; Inhibitory Concentration 50 ; Kinetics ; Piperidines ; analysis ; pharmacology ; Plasmids ; Recombinant Proteins ; genetics ; metabolism ; Transfection

Objective To observe the effects of 75 gram glucose oral tolerance test (75 g OGTT) and standard mixed meal test (SMMT) on insulin secretion function of the islets of Langerhans and plasma free fatty acid (FFA) in patients with type 2 diabetes mellitus.Methods Seventy-six patients with type 2 diabetes without using insulin and with no obvious complications were recruited for 75 g OGTT following overnight fasting on the first day and SMMT (bread 50 g,egg 50 g and milk 250 ml) on the 7th day.Blood specimens were collected from each patients before the tests and 30 min,60 min,120 min and 180 min after glucose or meal load to measure their levels of plasma glucose,serum insulin,C peptide,FFA and lipids (total cholesterol,triglyceride,high-density and low-density lipoprotein cholesterol).Results No difference in fasting plasma glucose,serum insulin,C peptide,FFA and lipids between 75 g OGTT and SMMT was found.Postprandial plasma glucose 30 min,60 min,120 min and 180 min after 75 g OGTT was significantly higher than that after SMMT,with (15.3?3.5) vs (9.9?3.4) mmol/L,(18.2?4.8) vs (12.8?4.0) mmol/L,(16.3?5.8) vs (12.2?4.9) mmol/L and (10.6?5.4) vs (9.5?4.5) mmol/L (F=28.1,P

OBJECTIVETo explore the effects of hippophae juice on free radical metabolism of rat skeletal muscle and partial biomarkers in blood.

METHODSRandomly dividing the 30 SD rats into 3 groups (n = 10): sedentary group, training group and hippophae training group. Measuring related indices of skeletal muscle and blood in rat after 6 week training and hippophae juice supplement.

RESULTSCompared with training group, hippophae training group showed obviously longer exhaustive time, significantly increased antioxidant enzyme in skeletal muscle, remarkably decreased malonaldehyde (MDA) content in skeletal muscle, obviously increased testosterone (T) and hemoglobin (Hb) content in blood, significantly decreased creatine kinase (CK).

CONCLUSIONHippophae juice can impove the antioxidant ability of rat skeletal muscle, the level of T and Hb in blood, delay fatigue, therefore effectively enhance the aerobic stamina of rat.

Animals ; Creatine Kinase ; blood ; Free Radicals ; metabolism ; Hemoglobins ; metabolism ; Hippophae ; Male ; Muscle, Skeletal ; metabolism ; Rats ; Rats, Sprague-Dawley ; Testosterone ; blood

BACKGROUNDThe B7/CD28 pathway provides critical costimulatory signals for complete T cell activation, and members of this pathway have served as useful targets for immunotherapeutic strategies. In this study, we investigated the RNA interference (RNAi) effect induced by small interfering RNA (siRNA) targeting CD28 mRNA on human lymphocytes and its specificity.

METHODSAccording to CD28 gene sequence, we designed and synthysized three different siRNAs (siRNA-1, siRNA-2, siRNA-3) containing 21 bases using Silencertrade mark siRNA construction kit. These siRNAs were transfected into freshly isolated human lymphocytes with Lipofectamine 2000 reagent. At 24-hour, 48-hour and 72-hour post transfection, these cells were collected and analyzed. The changes of surface expression of CD28 gene were detected by flow cytometry, and the changes of CD28 mRNA levels were determined by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). The cell viability of transfected lymphocytes was determined by methyl thiazolyl tetrazolium (MTT) assay and trypan blue dye exclusion assay.

RESULTSThree siRNAs (siRNA-1, siRNA-2, siRNA-3) specifically targeting CD28 mRNA were successfully designed and constructed. Flow cytometry analysis showed that a decrease in CD28 expression was detectable at 24-hour post transfection. Different siRNA showed different inhibition effects on CD28 expression. At 48-hour post transfection, the degrees of reduction with siRNA-1, siRNA-2 and siRNA-3 were 22.10% +/- 1.63%, 73.50% +/- 1.02% and 42.90% +/- 0.89% respectively compared with the control (P < 0.001). Neither of the groups transfected only with siRNA or lipo showed marked reduction in CD28 expression (3.15% +/- 0.75% and 4.55% +/- 0.80%) (P > 0.05). Moreover, lymphocytes treated with siRNA-co showed no marked reduction in CD28 expression (5.07% +/- 0.96%) (P > 0.05). The results of semi-quantitative RT-PCR assay indicated CD28 mRNA level was inhibited after transfection of specific siRNAs. At least 4-fold of reduction in siRNA-2 group occurred at 48-hour post transfection compared with the control (P < 0.001). MTT assay and trypan blue dye exclusion assay demonstrated that the viable cell rations of transfected lymphocytes were significantly reduced in siRNA-1, siRNA-2 and siRNA-3 groups at 48-hour post transfection (P < 0.01). The control groups showed no marked reduction in cell viability (P > 0.05).

CONCLUSIONSThree different siRNAs were synthesized and transfected into lymphocytes. They could reduce the expression of CD28 and the CD28 mRNA level. siRNA-2 was the most efficient. The cell viability reduced correspondingly. Therefore, the silencing effect on CD28 mRNA induced by siRNA may contribute to costimulatory blockade. This result show that siRNA may be useful for further study on graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (allo-BMT).

Adolescent ; Adult ; CD28 Antigens ; genetics ; Cell Survival ; Cells, Cultured ; Flow Cytometry ; Gene Silencing ; Humans ; Lymphocytes ; metabolism ; RNA, Small Interfering ; pharmacology ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo construct a recombinant lentiviral vector (pXZ208-BDDhFVIII) mediating B-domain-deleted human coagulation factor VIII (BDDhFVIII) gene and investigate its expression in HLF, Chang-Liver and MSC cells.

METHODSBDDhFVIII gene fragment was separated by endonuclease digestion and was cloned into the multiple cloning sites of pXZ208 to construct a recombinant lentiviral vector pXZ208-BDDhFVIII. Viral particles were prepared by means of three-plasmid cotransfection of 293T package cells by calcium phosphate precipitation. After infection, the coagulant activity of human FVIII in the culture medium of 293T, HLF, Chang-Liver and MSC cells was assayed by one-stage method. The gene transduction efficiency was assayed by flow cytometry (FCM). Furthermore, PCR was performed to test the integration of BDDhFVIII.

RESULTSThe infection rates of HLF, Chang-Liver and MSC were (74.52 +/- 7.57)%, (27.24 +/- 6.53)% and (42.34 +/- 5.84)% respectively. The activities of FVIII in supernatants of HLF, Chang-Liver and MSC were (54.1 +/- 5.6)%, (22.5 +/- 2.9)% and (12.5 +/- 2.7)% respectively. BDDhFVIII gene integration was detected in all the infected cells.

CONCLUSIONThe recombinant lentiviral vector pXZ208-BDDhFVIII was successfully constructed and efficiently integrated into target cells to express human FVIII activity in vitro.

Cell Line ; Factor VIII ; biosynthesis ; genetics ; metabolism ; Gene Expression ; Genetic Vectors ; Humans ; Lentivirus ; genetics ; Plasmids ; Transfection

BACKGROUNDNonmyeloablative allogeneic bone marrow transplantation has been used since the 1990s as a new hematological stem cell transplantation strategy for treating hematological diseases. The purpose of this study was to explore the graft-versus-leukemia (GVL) effects of donor lymphocyte infusions (DLIs) after nonmyeloablative allogeneic bone marrow transplantations, while assessing the declines in treatment-associated morbidity, mortality, and graft-versus-host disease (GVHD).

METHODSA total of 615 (H-2k) mice were injected with L615 tumor cells and received 500 cGy (60Co gamma-ray) irradiation three days later, followed by an allogeneic bone marrow transplantation (allo-BMT). The allo-grafts consisted of 3 x 10(7) bone marrow cells and 1 x 10(7) spleen cells from BALB/C (H-2d) donor mice. Two days after the allo-BMT, the recipient mice were given 200 mg/kg of cyclophosphamide. Subsequently, recipient mice were infused with either donor spleen cells (2 x 10(7)) on day 14 or 21, or donor spleen cells (5 x 10(7)) pretreated with hydrocortisone and cyclosporin A (CsA) in vitro on day 14 post-BMT.

RESULTSThe median survival time of mice that received DLI on day 21 and pretreated DLI on day 14 post-BMT was longer than that of controls and the day 14 DLI group (P < 0.01). No evidence of severe GVHD was observed in the day 21 DLI group nor in the day 14 treated DLI group. Mixed chimerism was confirmed in the day 14 DLI group, the day 14 treated DLI group, and the day 21 DLI group on the thirteenth day post-transplantation; full donor chimerism was observed two weeks after DLI.

CONCLUSIONDonor lymphocyte infusion after nonmyeloablative bone marrow transplantation may reduce transplantation-associated morbidity and mortality while strengthening graft-versus-leukemia effects.

Animals ; Bone Marrow Transplantation ; immunology ; Cyclosporine ; pharmacology ; Female ; Graft vs Host Disease ; etiology ; Graft vs Leukemia Effect ; immunology ; Hydrocortisone ; pharmacology ; Lymphocyte Activation ; Lymphocyte Transfusion ; Male ; Mice ; Mice, Inbred BALB C ; Transplantation Chimera ; Transplantation, Homologous

OBJECTIVETo observe the effect of Wnt3a-transduced mouse bone marrow mesenchymal stem cells (MSC) on the proliferation of T lymphocytes.

METHODSMSC were isolated from C57BL/6 mouse bone marrow and expanded in vitro, then identified by flow cytometry and their differentiation capacity into osteocytes and adipocytes were determined. Recombinant plasmids containing Wnt3a gene, were transfected with lipofectamine into HEK293 cells by the AdEasy system. Viral particles were collected to infect MSC and adenovirus vector expressing GFP (Ad-GFP) was used as control. The expression of GFP in MSC was observed using fluorescence microscopy and the protein levels of Wnt3a and β-catenin were determined by Western blot. Wnt3a-transduced and Ad-GFP transduced MSC were separately cocultured with spleen lymphocytes stimulated by ConA, at the ratio of 1:100, 1:50 or 1:10 respectively. The proliferation rate of T lymphocytes was estimated by Cell Cout Kit-8 (CCK-8) and the level of cytokine by ELISA.

RESULTSFCM analysis showed that the MSC were highly positive for CD90.2, CD44 and negative for CD34, CD45, they could differentiate into osteoblasts and adipocytes after induction; The titer of recombinant adenoviruses was up to 1 × 10(10) pfu/ml. After infected with the adenoviruses, MSC had the strongest GFP expression at 72 h and the efficiency of infection was 50%-60%. The expressions of Wnt3a and β-catenin protein in the Wnt3a-transduced MSC were significantly increased. MSC could suppress the proliferation of T lymphocytes in a dose-dependent manner. When MSC cocultured with spleen lymphocytes at 1:10 ratio, T lymphocyte proliferation rate and the level of IFN-γ were (55.41 ± 1.75)% and (326.70 ± 14.41) pg/ml respectively in Ad-GFP transduced MSC group, while in Wnt3a-transduced MSC group, they were (37.27 ± 2.66)% and (218.80 ± 12.93) pg/ml respectively. There was no effect on the production of IL-2.

CONCLUSIONCompared to Ad-GFP transduced MSC, Wnt3a-transduced MSC exhibit a more potent inhibitory effect on the proliferation of T lymphocytes.

Animals ; Bone Marrow Cells ; cytology ; metabolism ; Cell Differentiation ; Cell Proliferation ; Female ; Lymphocyte Activation ; Mesenchymal Stromal Cells ; cytology ; metabolism ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL ; T-Lymphocytes ; cytology ; Transduction, Genetic ; methods ; Wnt3A Protein ; genetics ; metabolism

This study was aimed to investigate the protective effect of Wit3a gene modification on mouse bone marrow mesenchymal stem cells against the injury induced by Ara-C. The gene-modified MSC steadily expressing Wnt3a were established by adenovirus system. The acute direct damage effects of different concentrations of Ara-C on the unmodified MSC and the gene-modified MSC were assessed by using an in vitro culture system, and the corresponding controls were set. The proliferation and apoptosis of MSC exposed to Ara-C were detected by cell count kit-8 (CCK-8) and flow cytometry. The expression of BCL-2 protein related with cell apoptosis was assayed by Western blot. The results indicated that as compared with unmodified MSC, Ara-C exhibited a less inhibitory effect on the proliferation of gene-modified MSC. There was obvious difference between unmodified MSC and gene-modified MSC (p < 0.05). The proliferation of gene-modified MSC began to recover at 72 hours after removal of Ara-C. However, unmodified MSC showed sustained suppression of proliferation after withdrawal of Ara-C. In apoptosis, the apoptosis rate of gene-modified MSC induced by Ara-C was significantly lower than those of unmodified MSC (p < 0.05). In addition, the expression levels of BCL-2 protein in gene-modified MSC were up-regulated compared with unmodified MSC (p < 0.05). It is concluded that Wnt3a gene modification can significantly mitigate the damage of mouse bone marrow MSC induced by Ara-C.
Animals ; Bone Marrow Cells ; drug effects ; metabolism ; Cytarabine ; adverse effects ; Mesenchymal Stromal Cells ; drug effects ; metabolism ; Mice ; Organisms, Genetically Modified ; Proto-Oncogene Proteins ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; Wnt3A Protein ; genetics

OBJECTIVETo study the effect of delayed sequential bone marrow transplantation on acute graft-versus-host disease (aGVHD) in major H-2 incompatible mouse transplantation.

METHODSC57BL/6 (H-2b) mice were used as donors and BALB/c (H-2d) mice as recipients. BALB/c mice were given 8.0 Gys total body irradiation (TBI) on day 0 and infused with a blend of bone marrow cells and spleen cells in different time. Transplantation was carried out as follows: group I TBI on day 0 and transplantation at 4 h after TBI; groups of II TBI on day 0 and transplantation at 4 h, d1, d2, d3 after TBI; groups III TBI on day 0 and transplantation at day 4 after TBI; groups IV TBI on day 0 and transplantation at day 4 through day 7 after TBI. Recipient's spleen H-2b cells were detected by flow cytometry and the level of serum cytokines (IL-2, IL4, IL-6, IL-10 and IFN-gamma) by ELISA. The survival, aGVHD and hematopoietic recovery were observed.

RESULTSaGVHD occurred in group I and the mice all died within 3 weeks after transplantation. The 60 day survival rates of groups of II and III were 30% and 50% respectively. The degree of aGVHD in group III was modest and the survival rate was higher than that in other groups (P <0.05). The peak time of IL-2, IFN-gamma, IL-4 and IL-10 in groups III and IV were later than that in group I. The levels of IL-4 and IL-10 in groups III and IV were higher than that in group I and for the levels of IL-2 and IFN-gamma were on the contrary (P < 0.05). The level of IL-6 in all groups peaked on day 5 to day 10 after TBI and was higher in group I than in others (P <0.05). In group IV the mean value of donor H-2b cells was (98.1 +/- 1.1)% on day 60 and WBC counts recovered normal on day 20.

CONCLUSIONSDelayed sequential transplantation can reduce the morbidity of aGVHD ,improve the survival rate and not affect the engraftment and reconstitution of hematopoiesis in mouse allo-BMT. The mechanism of aGVHD prevention may be related to the reducing of type 1 cytokines of T lymphocyte and the increasing of type 2 cytokines.

Animals ; Bone Marrow Transplantation ; immunology ; methods ; Disease Models, Animal ; Female ; Graft vs Host Disease ; immunology ; prevention & control ; Interleukin-2 ; blood ; Interleukin-4 ; blood ; Interleukin-6 ; blood ; Male ; Mice ; Mice, Inbred BALB C ; Mice, Inbred C57BL

OBJECTIVETo explore the silencing effect of short hairpin RNA (shRNA) on the CD28 of mice T lymphocytes by CD28-shRNA expressing plasmid evaluate the interfering effects (chronology and stability) mediated by shRNA and select out the most efficient CD28 shRNA sequence.

METHODSThree CD28 specific and one non-specific shRNA expressing plasmids were constructed and then transfected separately into mice spleen T lymphocytes. Non-transfected cells and non-specific shRNA were taken as controls. Inhibitory effect of CD28 shRNA was demonstrated by real-time quantitative PCR and Western blots. The sequence of the highest RNA interference (RNAi) efficacy was screened.

RESULTS(1) CD28 shRNA expressing plasmids were successfully constructed; (2) Three CD28 specific shRNAs effectively inhibited the expression of CD28 at the mRNA and protein levels, and there was a statistically significant difference comparing with the controls (P < 0.01): The copies of CD28 in mice spleen cells at the mRNA levels were persistently decreased by 99.62%, 99.89% and 99.80% respectively after 20 days, and so did at the protein level [(84.90 +/- 0.65)%, (96.49 +/- 0.03)%, (91.76 +/- 0.32)% respectively]. The highest inhibitory rate was in CD28 shRNA-2 group.

CONCLUSIONS(1) Specific shRNA can mediate long-term and stable silencing effects on CD28 gene; (2) shRNAs matching different sites of CD28 gene exert differential inhibitory effects.

Animals ; CD28 Antigens ; genetics ; Cells, Cultured ; Gene Expression Regulation ; Mice ; Mice, Inbred C57BL ; Plasmids ; genetics ; RNA Interference ; T-Lymphocytes ; metabolism ; Transfection