Objective: To study the influence of inserting glycines(Gly) on biological properties of HIV Tat-(Gly)n-thymidine kinase (-TK) fusion proteins. Methods: Different fragments containing 0, 2, 4 or 6 Gly were inserted between the HIV Tat gene and TK using gene splicing by overlap extension (SOEing) PCR, and the products were cloned into PBK vector. The vectors were then transferred into E. coli after sequencing. After IPTG induction, bacilli were collected and destructed by ultrasound; the fusion protein was collected and identified by monoclonal antibody of HIV protein. HepG2 cells were incubated with DMEM supplemented with 1 μg/ml fusion protein containing 0, 2, 4 or 6 Gly for 24 h. HepG2 cells of different groups were detected by immunofluoreseence assay with HIV Tat monoclonal antibody; the apoptosis rate of HepG2 cells was determined by cell flow cytometry after they were incubated with gencilovir (10 μg/ml) for 3 d and the survival rate of cells was recorded by trypan blue in different groups. Results: The recombined genes containing 0, 2, 4 or 6 Gly were successfully constructed, inserted into PBK vectors, and expressed into E. coli. Their proteins were obtained and purified. The level of fluorescence in different groups was similiar, but the cell survival rate and apoptosis rate were different. The highest apoptosis rate was 14.77%, which was found in the group containing 4 Gly, followed by 12.69% in 2 Gly group, 8.31% in HIV Tat-TK group, 4.36% in 6 Gly group, and 1.0% in group containing no Gly. Significant differences were found between each 2 groups (P<0.05). Trypan blue showed similar results in the cell death rate of different groups: the highest cell death rate was 80.2%, which was found in the group containing 4 Gly, followed by 65.4% in 2 Gly group, 58.4% in HIV Tat-TK group, 56.7% in 6 Gly group, and 9.1% in the group containing no Gly. Conclusion: The number of Gly inserted into HIV Tat-TK protein does not alter the transcellular function of upstream Tat protein, but does substantially influence the TK protein-mediated cytoxic effects of gencilovir, and the influence is the smallest when 4 Gly are inserted.

Objective To observe the changes of behavior, intracellular free calcium and the expression of calmodulin dependent protein kinase Ⅱ(CaMKⅡ) in the hippocampal neurons of chronic forced swimming stress rats. Methods Male Wistar rats were randomly divided into control group and chronic forced swimming stress group. The behavior was examined using sucrose preference test, open-filed test and Morris water maze. The intracellular free calcium was examined by fluorescence spectrophotometer. The expression of CaMKⅡ was detected using colloidal gold immunoelectron microscopy technique, Western blotting and RT-PCR. Results The consumption of sucrose and erect quantity of chronic forced swimming stress group were lower than those of control group(P<0.01, P<0.05). The escape latency time in Morries water maze test of chronic forced swimming stress group was higher than that of control group(P<0.01). The intracellular free calcium level and the expression of CaMKⅡ in the hippocampus was higher than that of control group(P<0.01).Conclusion The lasting dysfunction of Ca~(2+)/CaMKⅡ signaling cascades in hippocampus may play important roles in the pathogenesis of chronic forced swimming stress rats.

Background The development of retinopathy of prematurity(ROP) is associated with many regulatory cytokines related to neovascularization;however,the retinal expression and regulated mechanism of stromal cell-derived factor-1 (SDF-1) in mouse model of oxygen-induced retinopathy (OIR) remain uncertain.Objective This study was to investigate the expression of SDF-1 in retina of mouse model of OIR.Methods Forty 7-day-old C57BL/6J mice were divided into OIR group and control group.In OIR group,20 mice were exposed to 75% oxygen for 5 days and then to room air for 5 days.In control group,20 mice were raised in room air.The expression of SDF-1 in retina of mice was studied by immunochemistry and quantified by real time reverse transcriptase polymerase chain reaction (RT-PCR).Results The positive immunohistochemical staining for SDF-1 was found mainly locating at the ganglion cell layer in 12-day-old mice of OIR group;the stronger positive immunohistochemical staining for SDF-1 was noted mainly locating at the ganglion cell layer,vascular endothelial cells of inner retina,neovascular endothelial cells in 17-day-old mice of OIR group;the delicate positive immunohistochemical staining for SDF-1 was both found mainly locating at the inner retina and being around the retinal vascular in 12-day-old mice of control group and 17-day-old mice of control group.The expression of SDF-1 mRNA in 17-day-old mice of OIR group was higher than that of 12-day-old mice of OIR group (t=8.072,P＜0.05)and 17-day-old mice of control group(t=10.026,P＜0.05),respectively.The expression of SDF-1 mRNA in 12-day-old mice of OIR group was lower than that of 12-day-old mice of control group (t=4.336,P＜0.05).Conclusion SDF-1 might improve the onset of retinal neovascularization of OIR.

OBJECTIVETo observe the inhibitory effect of a eukaryotic expression vector expressing human IFN-gamma (pcDNA3.1- IFN-gamma) on HBV replication in hepG2.2.15 cells.

METHODSThe eukaryotic expression vector expressing human IFN-gamma was constructed using PCR and gene recombination technique. hepG2.2.15 cells were transfected with pcDNA3.1-IFN-gamma and the culture supernatant was collected to determine the expression of IFN-gamma protein by ELISA. The HBV DNA copies and the concentration of HBeAg and HBsAg were measured by fluorescence real-time PCR and ELISA kit, respectively.

RESULTSCompared with that of negative control and blank 2.2.15 cells, the concentration of HBeAg in the supernatant of 2.2.15 cells transfected with pcDNA3.1- IFN-gamma were decreased by 49%, and HBsAg concentration was lowered by 35% and 33%, respectively. A significant decrease of HBV DNA copies was observed in pcDNA3.1- IFN-gamma-transfected cells in comparison with the two control cells. No significant differences were noted in all the results between the two control groups.

CONCLUSIONWe have successfully constructed the eukaryotic expression vector expressing human IFN-gamma, which provides a basis for anti-HBV gene therapy using human IFN-gamma.

Genetic Vectors ; Hep G2 Cells ; Hepatitis B virus ; drug effects ; Humans ; Interferon-gamma ; genetics ; pharmacology ; Transfection ; Virus Replication ; drug effects

Objective To observe the effect of Bupleurum Liver-Coursing Powder on the neuronal apoptosis and autophage in hippocampus of depression model rats, and to explore the mechanism of its anti-depression effect. Methods 60 male SD rats were randomly divided into control group,model group and drug intervention group (n=20).The depression model was produced by giving the rats chronic unpredicted mild stress.The rats in model group and control group received the same volume of normal saline,and the rats in drug intervention group received Bupleurum Liver-Coursing Powder solution on the basis of model.The depressional behavior was examined using sucrose preference test,tail-suspension test and Morris water maze.Flow cytometry was employed for the detection and quantification of the apoptotic cells in the hippcampus. The expressions of LC-3 and Beclin 1 were detected using Western blotting method. Results The pencertages of sucrose preference of the rats in model group and drug intervention group were significantly lower, while the tail-suspension immobility time and the excape latency time were higher than those in control group (P<0.05);the apoptotic rates of cells,the ratios of LC3-Ⅱ/LC3-Ⅰand the expression levels of Beclin-1 were higher than those in control group (P<0.05).Compared with model group,the percentage of sucrose preference of the rats in drug intervention group was increased (P<0.05),the tail-suspension immobility time and the excape latency time were decreased (P<0.05),and the apoptotic rate of cells,the ratio of LC3-Ⅱ/LC3-Ⅰand the expression level were also decreased (P<0.05).Conclusion Bupleurum Liver-Coursing Powder has significant anti-depression effect, which may be related to inhibiting the apoptosis and degrading the autophage of neuros.

Objective To investigate the protective effects of rhein lysinate (RHL)on the blood vessel damage induced by oxidative stress in the mice,and to explore its mechanism.Methods The mouse models of oxidative damage were established by intraperitoneal injection of paraquat.30 C57 mice were randomly divided into control, paraquat model,and RHL prevention groups.The mice in RHL prevention group were given RHL by gavage for one week before performing model.The mice in other two groups were given equal volume of distilled water.For making model,paraquat was intraperitoneally injected in the mice in paraquat model and RHL prevention groups once a week for two weeks.The activities of superoxide dismutase (SOD)and glutathione peroxidase (GSH-Px) and the content of serum malonaldehyde (MDA) of the mice were detected 2 weeks after modeling. The pathological profile of blood vessel was observed by hematoxylin and eosin (HE)staining and the level of reactive oxygen species was observed by DCFH-DA staining.The expressions of genes related to blood vessel damage were detected by Western blotting method.Results Compared with control group,the activities of SOD and GSH-Px were decreased and the content of MDA was increased in paraquat model group (P < 0.05 ). Compared with paraquat model group,the activities of SOD and GSH-Px were increased and the content of MDA was decreased in RHL prevention group (P <0.05).The pathological examination indicated the structure of blood vessel of the mice was damaged and the level of reactive oxygen species of blood vessel was increased (P <0.05)in paraquat model group.The pathological changes were significantly improved and the level of reactive oxygen species of blood vessel of the mice was decreased (P < 0.05 )in RHL prevention group. The Western blotting analysis showed that compared with control group,the expression levels of nitric oxide endothelial synthase (eNOS)and caspase-3 of the mice in paraquat model group were decreased (P < 0.05),however the expression level of cleaved fragment of caspase-3 was increased (P < 0.05).Compared with paraquat model group,the expression levels of eNOS and caspase-3 of the mice in RHL prevention group were increased (P < 0.05 )and the expression level of cleaved fragment of caspase-3 was decreased (P <0.05).Conclusion Paraquat could induce vascular cell damage in vivo through increasing the levels of reactive oxygen species, and RHL could antagonize the effects of paraquat by scavenging reactive oxygen species, and up-regulating the eNOS expression and reducing the expression of the cleaved fragment of caspase-3.

Objective To determine the influence of protein fusion on the biological characteris- tics of hymidine kinase(TK)and human immunodeficiency virus(HIV)Tat recombinant protein. Methods By utilizing polymerase chain reaction(PCR)technique,different fragments containing two,four or six glycines(Gly)were inserted between the HIV Tat gene and TK,and cloned into PBK vector.After testified by sequencing,the vectors were transfected into E coli.After induced by iso- propyl thiogalactose(IPTG),bacilli were collected and destructed by ultrasonic,the fusion proteins were determined by monoclonal antibody against HIV protein.HepG2 cells were incubated in DMEM supplement with 10?g/mL HIV-Gly(n)-TK(n=0,2,4,6)fusion protein,TK-HIV Tat and only HIV Tat.HepG2 cells in different groups were detected by immunofluorescence assay 24 hours after transduction with HIV Tat monoclonal antibody.The rate of apoptosis after cells were incubated with gencilovir(10?g/mL)for 3 days was determined by cell flow cytometry,while survival cell ratio was recorded by trypan blue.The data were analyzed by statistics(t-test).Results The Tat-Gly(n)-TK (n= 0,2,4,6)recombinant genes were constructed and inserted into PBK vectors,which were expressed in E coli and then purified.Cells in different groups,which were incubated with Tat-Gly (n)-TK(n=0,2,4,6)fusion proteins,Tat-TK fusion protein,TK-Tat fusion proteins or only Tat proteins respectively,were detected by immunofluorescence assay.The intensities of fluorescence in different groups were almost same,but the ratios of cell survival or apoptosis were different.The highest ratio of cells apoptosis(14.77%)was in the group that cellular culture medium was mixed with Tat-Gly(4)-TK fusion protein,followed by the groups containing 6,2 glycines or no TK gene in genes(4.30%,12.69% and 1.03%,respectively).There were significant differences between each 2 groups among the all groups(t-test,P

BackgroundSeveral cornea collagen crosslinking methods have been used to treat keratoconus.However,the safety of these methods is dissatisfactory.Glyceraldehyde is a very potent and highly reactive crosslinking agent,with little toxicity,but its effect on corneal biomechanical property is poorly clear.ObjectiveThe aim of this study was to evaluate the biomechanical effects of glyceraldehyde collagen crosslinking on rats cornea.Methods Fifteen clean SD rats were randomly divided into 0.005 mol/L glyceraldhyde group,0.050 mol/L glyceraldhyde group and blank control group.Glyceraldhyde drops was topically administered in the right ryes 2 times per day for consecutive 7 days in the 0.005 mol/L and 0.050 mol/L glyceraldhyde groups,and no any eye drops was used in the blank control group.Seven days later,the rats were sacrificed.Transparency of corneal buttons in these different groups was evaluated.The central corneal strips of 2 mm×6 mm with 2 mm scleral tiasue were obtained for the biomeehanical stress-strain measurement,including ultimate stress ( MPa),ultimate strain (％) and 6％ elastic modulus (MPa).Corneal collagen fibril density was assessed by histological examination under a light microscopy.The use of the animals followed the Regulations for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission.ResultsThe words could be clearly displayed transcorneally in all the three groups.When strain was 6％,the stress was (0.463±0.065 ) MPa in 0.005 mol/L glyceraldehyde group,(0.846±0.240) MPa in 0.050 mol/L glyceraldehyde group,both showing a significant increase in comparison with (0.195±0.103 ) MPa of the blank control group (P=0.029,0.000 ).Following the crosslinking treatment,the ultimate stress was significant elevated in 0.050 mol/L glyceraldehydes group compared with the blank control group ( ( 10.759 ± 3.337 ) MPa vs.(5.295± 1.313 ) MPa,P =0.007 ),but no significant change between the 0.005 mol/L glyceraldehydes group and the blank control group ( ( 6.043 ±2.084) M Pa vs.(5.295 ± 1.313 ) MPa,P =0.660 ).Corneal ultimate strain was lower in the 0.005 mol/L glyceraldehyde group and 0.050 mol/L glyceraldehyde group than the blank control group (36.57％ ±3.09％ vs.43.87％ ± 1.89％,P =0.009;28.53％ ±1.89％ vs.43.87％ ± 1.89％,P =0.000).However,significantly increased 6％ elastic modulus were seen in the 0.005 mol/L glyceraldehyde group and 0.050 moL/L glyceraldehyde group compared with the blank control group ( ( 7.718 ± 1.076 ) MPa,( 14.102 ± 4.011 ) MPa vs.( 3.252 ± 1.717 ) M Pa),with statistically significant differences ( P =0.029,0.000).Histological examination showed a increase of collagen fiber density in the 0.050 mol/L glyceraldehyde group.Conclusions Corneal collagen crosslinking induced by glyceraldehyde strengthens biomechanical intensity and increases the density of corneal collagen fiber.But the safety of glyceraldehyde crosslinking for keratoconus needs further study.

OBJECTIVETo study the relationship between the disturbance of nitric oxide/endothelin-I (NO/ET-1) and the hepatic injury following limb ischemia/reperfusion (I/R) in rats as well as the regulation of NO/ET-1 system by limb ischemia preconditioning (IPC).

METHODSUsing limb ischemia/reperfusion injury model rats, animals were randomly divided into three groups (n = 6): control group, I/R group and IPC group. The contents of alanine aminotransferase (ALT), aspartate aminotransferase (AST) in the plasma as well as nitric oxide (NO), endothelin-1 (ET-1), nitric oxide/endothelin-1 (NO/ET-1) in the plasma and the liver were measured. The levels of total nitric oxide synthase (tNOS), inducible nitric oxide synthase (iNOS), constitutive nitric oxide synthase (cNOS) in the liver were determined. The expression of iNOS and endothelial NOS (eNOS) were detected by the immunohistochemical method. The morphologic changes stained with hematoxylineosin were observed under microscope.

RESULTSIt was found that the levels of NO, ET-1 in the plasma and the liver tissue all increased after reperfusion, while the values of ALT, AST, NO/ET-1 decreased. Liver pathology revealed that after limb I/R there were edema, villous microvascular congestion, infiltration of polymorphonuclear neutrophil (PMN), cell degeneration in part cells of the liver. The hepatic damage was deteriorated. While the expression of iNOS elevated, cNOS (mainly eNOS) reduced and total NOS increased. The protection of the limb IPC attenuated the disturbance of NO/ET-1.

CONCLUSIONThe hepatic injury following limb I/R is related to the disturbance of NO/ ET-1. The protection of the limb IPC might be conducted by its regulation of NO/ET-1 system. The elevation of endothelial NOS and the reduction of non-endothelial NOS generated the NO in this situation.

Animals ; Endothelin-1 ; metabolism ; Extremities ; blood supply ; Ischemic Preconditioning ; Liver ; metabolism ; Male ; Nitric Oxide ; metabolism ; Rats ; Rats, Wistar ; Reperfusion Injury ; prevention & control

AIMTo investigate the changes of large-conductance calcium-activated potassium channels (BKCa, MaxiK) during aging and relations between the changes and blood pressure.

METHODSMale spontaneously hypertensive rats (SHR) aged 9, 15, 21, 27, 33 weeks (the number of each weeks SHR was 4) were selected as hypertension group rats, corresponding gender, weeks and number Wistar-Kyoto rats (WKY) as control group rats. Blood pressure of abdominalis aorta of each weeks SHR and WKY were measured by BL-420F experimental system of biological function. The arteria mesenteric minor (AMM) were isolated in blunt dissection method. The vascular smooth muscle cells (VSMCs) of AMM were isolated with prolease. The potassium current, the current after BKCa were blockaded by Tetraethylammonium (TEA) and the capacitance of membrane (Cm) of VSMCs of AMM were recorded with using whole cell patch clamp, and calculated the BKCa current and the BKCa current density. Probe the correlation of the changes of BKCa current density with MABP during aging.

RESULTSThe potassium current density and BKCa current density of VSMCs of AMM of SHR were decreasing during aging, however, the changes of WKY had no statistically significance (P > 0.05). The BKCa current density was extremely correlative with MABP in SH R (the values of r were -0.7174), in WKY, the BKCa current density was correlative with MAB P r = -0.4832.

CONCLUSIONBKCa current and current density attenuate with aging, the level of blood pressure is response of the attenuated degree. The BKCa current density is extremely correlative with the blood pressure.

Aging ; physiology ; Animals ; Blood Pressure ; physiology ; Cell Membrane ; physiology ; Hypertension ; metabolism ; physiopathology ; Large-Conductance Calcium-Activated Potassium Channel alpha Subunits ; Large-Conductance Calcium-Activated Potassium Channels ; metabolism ; physiology ; Male ; Membrane Potentials ; physiology ; Mesenteric Arteries ; cytology ; Muscle, Smooth, Vascular ; cytology ; metabolism ; physiology ; Patch-Clamp Techniques ; Potassium Channels ; metabolism ; physiology ; Rats ; Rats, Inbred SHR ; Rats, Inbred WKY