Child ; Humans ; Nephrology ; Pediatrics

Child ; Humans ; Vesico-Ureteral Reflux ; therapy

Objective To determine the effect of Vibrio vulnificus cytolysin (VVC) inducing ap-optosis in human umbilical vein endothelial cell(HUVEC) and its possible mechanism. Methods The en-tire vvhA gene that encoding VVC from V. vulnificus strain GTC333 was amplified by PCR and sequenced af-ter T-A cloning. E. coli BL21DE3pET-42a-vvhA, a prokaryotic expression system of the vvhA gene, was then con-structed. Ni-NTA affinity chromatography was applied to purify the target recombinant protein rVVC, and SDS-PAGE plus Bio-Rad Agarose Image Analyzor were used to measure the output of rVVC and to determine the purity of rVVC extract. The activity of rVVC dissolving rabbit erythrocytes was detected by hemolysis test. DPNH chromotometry and TphBNa chromotometry were performed to examine the contents of LDH and K+ in the supernatants of rVVC-treated HUVEC cultures, respectively. The effect of rVVC inducing apepto-sis of HUVEC was detected by flow cytometry, rVVC was labeled with FITC and the location of FITC-labe-ling rVVC in HUVEC was observed by laser canfocal microscopy. Results The cloned whA gene had 96.09% and 98.26% similarities of nucleotide and amino acid sequences compared to the corresponding se-quences in GenBank. rVVC, with a dosage of 1 μg/ml, could dissolve rabbit erythrocytes (P<0.01). 10 μg/ml rVVC was able to promote the increases of K+ content (P<0.01) but no change of LDH content could be found in the cell supernatants. HUVEC was apoptotic after the cell was treated with 1～100 μg/ml of rVVC for 2 h. In the 5～240 min duration of co-incubation of FITC-labeling rVVC and HUVEC, the rV-VC gradually moved from surface to inner side of the membrane and then entered the cytoplasms. When FITC-labeling rVVC treated HUVEC for 30 min, most of the rVVC was found to be intracellular location. Conclusion rVVC has cytolytic activity. VVC has an ability to enter HUVEC and causes injury of HUVEC via inducing apoptosis, which may be the major pathogenic mechanism of VVC.

Objective To determine the modality of Leptospira interrogans invading human and murine mononuclear-macrophages and diversity of leptospiral phagocytotic vesicle formation. Methods Transmission electron microscopy was applied to observe the invasion of L. interrogans serogroup Icterohaemorrhagiae serovar Lai strain Lai into murine mononuclear-macrophage-like cell line J774A. 1 and PMA-activated human monocyte line THP-1 and the formation of leptospiral phagocytotic vesicles. By using immunofluorescence plus either laser confocal microscopy or fluorescence spectrophotometry, the changes of intracellular leptospiral numbers in J774A. 1 and PMA-activated THP-1 cells before and after block with endocytosis inhibitors monodansylcadaverin (MDC), phenylarsine oxide (PAO) and clathrin antibody were investigated. Results The leptospires in J774A. 1 cells were located in phagocytotic vesicles while the leptospires in THP-1 cells had no package with phagocytotic vesicle membrane. Both MDC and PAO presented the effect inhibiting endocytosis of L. interrogans into J774A. 1 and THP-1 cells in dose-dependent manner. The numbers of leptospires in J774A. 1 and THP-1 cells that pre-blocked with 10 μmol/L or above MDC and 1 μmol/L or above PAO were significantly less than that in the two cells untreated with MDC and PAO (P＜0.05＝. After J774A. 1 and THP-1 cells were blocked with clathrin antibody, the numbers of intracellular leptospires were also remarkbly decreased ( P<0.05 ).Conclusion Leptospira interrogans can invade into both human and murine mononuclear-macrophages through the way of clathrin-dependent endocytosis. There is an opposite diversity of leptospiral phagocytotic vesicle formations in human and murine mononuclear-macrophages, which may result in the difference of pathogenesis in human and mice after infected with L. interrogans.

Objective To determine the change of expression level of Leptospira interrogans sph2 gene, and hemolytic and cell apoptosis-inducing activities of sphingomyelinase hemolysin Sph2. Methods Entire sph2 gene fragment was amplified by PCR from genomic DNA of L. Interrogans serovar serogroup Icterohaemorrhagiae serovar Lai strain Lai, and sequenced after T-A cloning. Subsequently, a prokaryotic expression system of sph2 gene was constructed. The expression of target recombinant Sph2( rSph2 ) was examined by SDS-PAGE and the expressed rSph2 was extracted by Ni-NTA affinity chromatogaphy. The hemolytic activity of rSph2 was measured by hemolytic test in sheep blood agar plate and spectrophotometry-based hemoglobin measurement, and the apoptosis-inducing activity of rSph2 to murine mononuclear-macrophagelike cell line(J774A. 1) and hepatic cell line(IAR20) was determined by flow cytometry. A real-time fluorescence quantitative RT-PCR was applied to detect the change of sph2 mRNA levels before and after L. Interrogans strain Lai infecting J774A. 1 and IAR20 cells. Results The cloned sph2 gene had 100% sequence identity to the corresponding gene in GenBank. The constructed prokaryotic expression system was able to efficiently express rSph2. The rSph2 could lyse sheep erythrocytes in concentration-dependent pattern. 10μg/ml rSph2 could induce the apoptosis of J774A. 1 cells and IAR20 cells, and the peak apoptotic rates were 23.96% and 32.92%, respectively. The mRNA level of sph2 gene was significantly elevated within 0.5-2 h of L. Interrogans strain Lai infecting either J774A. 1 or IAR20 cells, and then the mRNA level was quickly descended. Conclusion The sph2 gene of L. Interrogans strain Lai has a transient expression when the microbe contacts host cells. rSph2 possesses activities of sheep erythrocyte lysis and inducing macrophage and hepatocyte apoptosis, indicating Sph2 as an important virulence factor during pathogenic process of Leptospira.

Objective To compare the sensitivity and specificity of Leptospira interrogans using loop-mediated isothermal amplification (LAMP) and real-time PCR technology, then looking for a rapid,sensitive and specific methods for the detection of Leptospira interrogans. MethodsIn accordance with lipL41 gene from Leptospira interrogans, primers for LAMP and real-time PCR were designed and used to detect Leptospira interrogans in cultured 15 reference strains of 15 serogroups in China, then compared the sensitivity and specificity of the two methods in the detection of Leptospira interrogans. ResultsThe LAMP reaction could be completed within 30 min, and whole process of it less than 60 min. The whole real-time PCR reaction could be finished at about 60 min. Both of them had the same detection sensitivity and specificity,the lower detection limits in the reactions was approximately 100 copies and there was no false positive occurred. ConclusionBoth LAMP and real-time PCR were time-saving and had the same sensitivity and specificity. But LAMP reaction could be done under a constant temperature conditions, and need not a special expensive equipment. Therefore, as a sensitive and specific method for quantifying Leptospira interrogans,the LAMP assay was more rapidly and convenient than conventional methods.

Objective To construct the T-cells and B-cells combined epitope peptide gene based on the LipL32,OmpL1 and LipL21 protein from Leptospira interrogans and E.coli expression system,and better understanding of the immunological activity of the recombinant protein. MethodsThe immunodomaint T- and B-cells combined epitopes of LipL32,OmpL1 and LipL21 were identified and used to synthetic a new gene and then construct its prokaryotic expression system.The expression of recombinant protein was determined by SDS-PAGE; MAT was used to determine the titer of the antiserum to L. interrogans standard strains of China ; Western blot and ELISA were used to identify the immunity activity of the recombinant protein.Results The synthetic gene was effectively expressed in E.coli BL21 ( DE3 ) strain and mainly presented in dissoluble protein.Western blot result showed that the expression protein react well with the antibodies from immunized rabbit by Leptospira or recombinant protein.ELISA and MAT results showed that the multiepitope protein could cross-react with different serogroup or serovar of Leptospira.Conclusion In this study,we successfully constructed the recombinant T- and B-cells combine epitope gene of leptospires and expressed it in E.coli.The recombinant protein had a good immune activity,and could cross-reacted with antibodies from different serogroups Leptospira infected patients.

Objective To explore the molecular effect and interaction among nephrin, podocin, CD2AP and ?-actinin-4. Methods Firstly, the recombinant RNA interference (RNAi) plasmid-psiRNA-hH1GFPzeo, specifically targeting to the mRNA of nephrin, podocin, CD2AP or ?-actinin-4, was respectively tansfected into the mouse podocyte clone (MPC5) to each knockdown (KD) the expression of nephrin, podocin, CD2AP or ?-actinin-4. Molecular distributions were revealed by confocal microscopy, and the mRNA and protein expressions were detected with semi-quantitative RT-PCR and Western blotting. Results (1)In podocin KD group (siPod966 and siPod54), the mRNAs of podocin and nephrin were not detected, their protein decreased 92% and 79%, 82% and 67%, respectively. The mRNA and protein level of CD2AP increased 62% and 42%, 71% and 46%, respectively, whereas ?-actinin-4 did not change. In nephrin KD group (siNep492), the mRNA expression and protein level of nephrin were not detected, CD2AP increased 35% and 48%, respectively; and whereas podocin and ?-actinin-4 did not change. In CD2AP KD group (siCda744 and siCda21), the mRNA of expression CD2AP was not detected, and its protein level decreased 92% and 83%, the mRNA and protein of nephrin decreased 60% and 48%, 76% and 72%, respectively; podocin increased 38% and 22%, 56% and 44%, respectively; whereas ?-actinin-4 did not change. In ?-actinin-4 KD group (siAct1790 and siAct319), the mRNAs expression of ?-actinin-4 and nephrin decreased 69% and 58%, 64% and 49%, respectively; their protein level decreased 81% and 55%, 71% and 64%, respectively. However, the mRNAs of podocin and CD2AP increased 50% and 34%, 45% and 28%, respectively; and their protein level increased 64% and 46%, 65% and 42%, respectively. (2) With their expression change, the distributions of nephrin, podocin and CD2AP shifted evidently from the cell membrane surface to the nucleus circumference, whereas ?-actinin-4 showed no change, which was still localized in the cytoplasm and further extended to foot processes. Conclusion (1) Nephrin might more independently play a crucial role in the slit diaphragm complex. (2) Alpha-actinin-4 might interact direcdy or indirectly with nephrin, podocin and CD2AP. (3) The relationship among these podocyte molecules might not be spontaneous, either a single-directional or bi-directional reaction. (4) The normal localization of these podocyte molecules might depend on their normal expression quantity.

Objective To dynamically observe the expression of slit diaphragm complex molecules, including nephrin, podocin, CD2AP, and cytoskeleton protein a-actinin-4, in adriamycin-induced nephrotic (ADN) rats, and to further explore the molecular behavior of podocyte proteins during the occurrence and development of proteinuria and their possible mechanisms. Methods Adriamycin nephropathy was induced by a single tail intravenous injection of adriamycin. Renal tissue samples were collected at day 3, 7, 14, and 28, respectively. The distribution, mRNA expression and protein expression of nephrin, podocin, CD2AP and a-actinin-4 were examined by indirect immunofluorescence, real-time PCR and Western blotting, respectively. Results (1) After the adriamycin injection, a significant increment of the 24-hour urinary protein was observed at day 14 and persisted up to day 28 (P

Objective To explore the molecular mechanisms underlying therapeutic responses of the anti-proteinuria drugs from the view of podocyte molecule. Methods Adriamycin (ADR) nephropathy was induced by a single tail intravenous injection of adriamycin. Lisinopril, prednisone and all-trans retinoic acid (ATRA) were administered once a day to the adriamycin-induced nephrotic rats at the first day after adriamycin injection respectively. Renal tissue samples were collected at day 3, 7, 14, and 28 after adriamycin injection respectively. The distribution, mRNA expression and protein expression of nephrin, podocin, CD2AP and ?-actinin-4 were examined by indirect immunofluorescence, real-time PCR and Western blotting, respectively. The interactions among nephrin and podocin, nephrin and CD2AP, as well as the nephrin phosphorylation were detected by immunoprecipitation, respectively. Results Compared to the control rats, 24 h urinary protein of the ADR rats increased significantly at day 14 (P