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Objective To explore the effects of oscillating blood glucose on apoptosis in renal tubular epithelial cells of diabetic rats and the role of oxidative stress.Methods Renal tubular epithelial cells (HK-2) were cultured in vitro with stable high glucose or oscillating high glucose,and MTF assay was applied to the neasurement of cell proliferation.Streptozotocin induced diabetic model was established with SD rats and the oscillating high blood glucose animal model was induced by intraperitoneal injection of insulin and glucose at different time points every.day.12 weeks later 24 h urine protein (24hUP),blood urea nitrogen (BUN),serum creatinine (Scr),superoxide dismutase (SOD), and malondialdehyde (MDA)were determined. Apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL),and immunohisto-chemistry was used to detect apoptosis associated gene Bax,Bcl-2,and NOX-4 expression in kidney.Changes in ultrastructure were observed.Results Oscillating high glucose may inhibit renal cells proliferation obviously when comparing with stable high glucose.In the rats with oscillating blood glucose rather than those with stable high blood glucose,there was a significant increase of BUN,Scr,24hUP,and MDA and a decrease of SOD[ (21.50 ± 1.72 vs 12.50 ± 1.85 )mmol/L,(97.51 ± 7.84 vs 82.12 ± 11.48 ) μmol/L,( 1.57 ± 0.09 vs 1.04 ± 0.12 ) mg/24 h,( 23.50 ± 1.87 vs 14.82 ± 2.96) nmol/ml,( 17.22 ± 1.12 vs 21.11 ± 1.80) U/ml,all P＜0.05 ] ; cell apoptosis was intensified with the up-regulation of Bax and NOX-4 protein expression and down-regulation of Bcl-2 in glomerular endothelial cells; and more severe pathological damages were observed.ConclusionComparing with stable high blood glucose,oscillating high blood glucose induces more apoptosis and less proliferation of renal tubular epithelial cells and the mechanism may be related to the increased oxidative stress.
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Objective To investigate the mechanism underlying the WNK4 kinasemediated inhibitory effect on BK channel. Methods Cos-7 cells were cotransfected with BK in combination with either CD4 (control group) or wild type WNK4 (WNK4-WT).Immunostaining and confocal microscopy,chemiluminescence,Western blotting analysis were then employed to determine the BK localization in cells,BK surface expression and total protein level,respectively.To further investigate whether the reduction of BK protein expression is due to an increase in degradation through a lysosomal pathway,BK protein level was determined after treated with bafilomycin A1(Baf A1),a proton pump inhibitor affecting lysosomal degradation. Results Immunostaining and confocal microscopic study showed that BK was localized both in plasma membrane and cytosol in the control group.After cells transfected with WNK4-WT,BK expression was markedly reduced.Chemiluminescent assay found that BK surface expression level was 299.9±18.6 in the control group,whereas it was significantly reduced (148.4±13.7,P＜0.01) in the WNK4-WT group.Western blotting analysis showed that total BK protein level was markedly reduced in the presence of WNK4-WT compared to the control group.WNK4-WT was shown to significantly reduce the BK total protein level (42.3％±15.2％) compared to the control group (100％) (P＜0.01).When the cells was treated with Bafilomycin A1 (Baf A1,0.5 μmol/L),WNK4-mediated reduction in BK protein was reversed (82.2％±12.1％,P＜0.05). Conclusions WNK4 inhibits total and surface protein expression of BK in Cos-7 cells whick is likely due to an increase in BK degradation through a lysosomal pathway.
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Objective To investigate the effect of syndecan-4 on the proliferation and extracellular matrix (ECM) secretion of human mesangial cells(HMC) stimulated by basic fibroblast growth factor (bFGF) and to evaluate the role of syndecan-4-PKCα pathway. Methods The expression of syndecan-4 in HMC was observed by immunofluorescence. After the down-regulation of syndecan-4 in HMC by RNA interference, the cell proliferation was detected by MTT. The secretion of fibronectin (FIN), type IV collagen, type Ⅰ collagen was assessed by ELISA. The copy number of syndecan-4 and PKCα was measured by fluorescent quantitation PCR at different time points. Results Syndecan-4 was expressed in HMC. bFGF could promote the cell proliferation and ECM secretion together with the PKCα copy number per million house-keeping genes of HMC, which could be reversed by the syndecan-4 siRNA transfection (MtT: 48-60 h, P<0.01; FiN: 24 h, P<0.01, 48-96 h, P<0.05; type Ⅳ collagen: 72-96 h, P<0.05; PKCa: 0 h, P<0.05, 12-48 h, P< 0.01). Conclusion Syndecan-4 may regulate the proliferation and ECM secretion of HMC stimulated by bFGF through syndecan-4-PKCα pathway.
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Objective To investigate the features of brainstem auditoryresponses (BAR) in patients with attention deficit and hyperactive disorder (ADHD), mental retardation and conduct disorder. Methods BAR in children with ADHD ( n =37), mental retardation (MR, n =24) and conduct disorder (CD, n =22), and in normal children ( n =30) were measured by use of Nicolet Spirit electrophysiological instrument delivering stimulation of Clicks. Results The absolute latencies (AL) of wave Ⅲ、Ⅴ recorded from Fz region (WⅢ、Ⅴ/Fz) and wave Ⅲ from Pz region (WⅢ/Pz) as well as the absolute amplitudes (AA) of WⅢ/Fz and WⅤ/Pz were significantly different ( P
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Objective To investigate the clinical application of various parameters of visual evoked potential (VEP) and auditory evoked potential (AEP) in patients with attention deficit and hyperactive disorder (ADHD), mental retardation (MR) and conduct disorder (CD). Methods Thirty-seven ADHD patients, 24 MR patients, 22 CD patients and 36 normal subjects were included in this study. The VEP and AEP were recorded from every subject and analyzed. Results A significant difference was found among 4 subject groups, with both latencies (Oz/N_1, P_2) and amplitudes of VEP (Cz/P_2, P_3 and Oz/P_3 ) (P