ObjectiveTo investigate the effect and mechanism of prostaglandin E2 (PGE2) in renin regulation at the juxtaglomerular apparatus (JGA). MethodsMacula densa cell line (MMDD1) was cultured on the special filter. In the medium on the apical lateral of the cells, low concentration of sodium chloride, chloride and different doses of angiotensin Ⅱ (Ang Ⅱ) were used to stimulate the PGE2 secretion. The PGE2 concentration was tested by ELISA. In the animal experiment, the response of plasma renin activity (PRA) to acute intraperitoneal administration of captopril (30 mg/kg) was determined, in conscious wild-type (WT) and cyclooxygenase COX-2-/- mice on C57BL/6 genetic backgrounds. PRA was measured in plasma obtained by tail vein puncture. Different concentrations of PGE2 were used to stimulate the renin secretion of primary cultured JGA cells from COX-2-/- mice and wild type mice. In specific Gsα gene delete mice (low renin producing mice), 24 h urine was collected to test the concentration of PGE2. The COX-2 mRNA and protein of the kidney cortex were observed by real-time PCR and immunohistochemicul staining. ResultsLow chloride could stimulate the PGE2 secretion both at the apical and basement of the macula densa cells. In COX-2-/- mice, the base PRA and were obviously lower than wild type mice. Captopril could stimulate the PRA of (COX)-2-/- mice increasing 32.8 times. But Ang Ⅱ had no effect on PGE2 secretion in macula densa cells. In primary cultured JGA cells, the decreasing renin seretion was partly recovered by PGE2 in cells from COX-2-/- mice. In low renin producing mice, the expression of COX-2 mRNA in the kidney cortex increased by (8.07±1.08) times (n=6, P=0.0022). The COX-2 protein of the kidney cortex and the urine PGE2 increased by several times. ConclusionsLow chloride is the primary stimulation messenger of PGE2 secretion in macula densa cells. The PRA in COX-2-/- mice can be stimulated by angiotensin converting enzyme inhibitor, but the Ang Ⅱ has no direct effect on macula densa cells. When renin production is abolished in JGA cells (Gsα delete mice), COX-2 mRNA and protein up-regulation is observed in kidney cortex and macula densa. PGE2 plays an important role in regulation of renin secretion and renin release in JGA by precise feedback mechanism.

ObjectiveTo investigate the role of MG-132, a specific dipeptide proteasome inhibitor, on the proliferation, apoptosis and the related proteins in renal interstitial fibroblasts. MethodsRenal interstitial fibroblasts (NRK-49F) were induced by transforming growth factor β1 (TGF-β1, 5 μg/L) and pro-treated with MG-132 (0～5 μmol/L). The cell proliferation was measured with MTT method. Cell cycle and apoptosis were analyzed by flow cytometry. The apoptosis was also analyzed by Annexin V/PI staining and DNA ladder. Expression of p53, p27, p21, caspase-3, Bcl-2 and Bax protein was examined by Western blot. ResultsTGF-β1 (5 μg/L) could stimulate the proliferation of NRK-49F. MG-132 (0.25～5 μmol/L) could inhibit TGF-β1-induced proliferation in a dose-dependent manner through G1-arrest. TGF-β1 alone could not induce apoptosis (3.880%±0.365% vs 4.723%±1.582%). But pretreatment of MG-132 (0.1～2.5 μmol/L) could significantly induce apoptosis of TGF-β1-stimulated NRK-49F in a dose-dependent manner. Typical DNA ladder was also confirmed in these two groups in the DNA fragments analysis after being incubated with 2.5 μmol/L MG-132 with or without 5 μg/L TGF-β1. Western blot showed that MG-132 could activate the cell-cycle and apoptosis-related proteins such as p53, p21, caspase-3, Bax and inhibit Bcl-2 in a dose-dependent manner, while expression of p27 remained unchanged. ConclusionsProteasome inhibitor MG-132 can inhibit proliferation and induce the cell apoptosis in renal interstitial fibroblasts stimulated by TGF-β1. The mechanism may be associated to the mediation of p53, p21, caspase-3, Bcl-2 and bax pathways. Protoasome inhibitor may be a new strategy to treat renal interstitial fibrosis.

ObjectiveTo evaluate the nephroprotective effects of transplanting metanephric mesenchymal cells (MMCs) into the renal subcaspsule of rats with acute tubular necrosis (ATN) induced by gentamicin. MethodsMMCs were expanded in culture and immunocytochemistry was used to characterize the cells. After gentamicin-induced ATN, fluorescence-labeled cells were transplanted and traced in kidney tissues by fluorescence microscopy. Serum creatinine (Scr) and N-acetyl-b-D-glucosaminidase (NAG) were tested. Kidney pathology was studied by hematoxylin-eosin staining. Apoptosis was examined by the TUNEL assay. Ki-67 and Bcl-2 expression was examined by immunohistochemistry. ResultsMMCs were expanded in culture and the phenotype of the cells was vimentin-positive and keratin-negative. Compared with other ATN groups, in the MMCs-treated group, Scr and NAG clearly decreased[14d Scr: (101.38±20.46) μmol/L vs (248.78±23.15), (252.98±33.52), (229.08±18.18) μmol/L;NAG: (14.83±7.74) U/L vs (33.33±14.88), (29.62±10.54), (30.22±10.94) U/L, P<0.05, respectively];the histopathoiogic lesion scores were lower (P<0.05);the Ki-67 antibody and apoptosis of renal tubular epithelial cells were improved or reduced respectively;the expression of Bcl-2 protein was up-regulated (P<0.05). ConclusionThe subcapsular transplantation of MMCs can ameliorate renal function and repair kidney injury.

Objective To study the arterial stiffness in non-diabetic pre-dialysis chronic kidney disease (CKD) patients and to explore the associated factors. Methods Automatic pulse wave velocity (PWV) measuring system was used to examine carotid-femoral pulse wave velocity (CFPWV) as the parameters reflecting central elastic large arterial elasticity. Vascular calcification was quantitatively evaluated by plain radiographic film of abdomen, pelvis and hands. Blood pressure, biochemical parameters and intact parathyroid hormone (iPTH) were routinely detected. Stepwise multiple linear regression analysis was used to assess the associated factors of arterial stiffness. Results Ninety-six non-diabetic pre-dialysis CKD patients and 30 healthy people were enrolled in this trial. CFPWV in stage 3, 4 and 5 CKD patients was significantly higher than that in healthy controls [(11.63±2.39) m/s, (11.70±2.80) m/s, (12.88±2.49) m/s vs (9.70±1.66)m/s , all P<0.05]. Stepwise multiple regression analysis demonstrated that age, mean arterial pressure, vascular calcification and iPTH were independent impact factors of CFPWV. Conclusions Arterial stiffness of large artery increases in non-diabetic pre-dialysis CKD patients. Age, mean arterial pressure, vascular calcification and iPTH are independent impact factors of CFPWV.

Objective To investigate the incidence, risk factors and outcome of acute kidney injury (AKI) following cardiac surgeries. Methods Clinical data of 1056 patients undergoing open heart surgery in Renji Hospital from January 2004 to June 2007 were retrospectively analyzed. Univariate and multivariate analyses were used to evaluate possible pre-,intra-, and post-operative parameters associated with AKI according to AKI Network (AKIN). Results Of the 1056 patients, 328 (31.06%) developed AKI. In-hospital mortality was 4.07% in all discharges while 11.59% in AKI patients (P<0.01). Multivariate logistic regression analysis revealed that increased age (OR=1.40), pre-operative hyperurieemia (OR=1.97), pre-operative left ventricular insufficiency (OR=2.53), combined surgery (OR=2.79), prolonged operation time (OR=1.43), post-operative circulation volume insufficiency (OR=11.08) were risk factors of AKI. Conclusions AKI is a common complication and associated with increased mortality following cardiac surgery. Increased age, pre-operative hyperuricemia, pre-operative left ventricular insufficiency, combined surgery, prolonged operation time, post-operative circulation volume insufficiency are useful in stratifying risk factors for the development of AKI.

ObjectiveTo investigate the prevalence and associated risk factors of chronic kidney disease (CKD) in adult population receiving body check from urban area of Hefei, Anhni. MethodsA total of 33 451 subjects who were older than 20 years and received healthy examination in Health Center of Anhui Provincial Hospital from January 2005 to December 2007 were enrolled in this study. CKD was defined as proteinuria, and/or hematuria, and/or using the simplified MDRD equation. ResultsThe prevalence of proteinuria was 2.74% (95%CI: 2.57%-2.92%), hematuria 7.67% (95% CI:7.39%-7.96%), and reduced eGFR 0.80%(95% CI:0.71%-0.90%). 9.92% (95% CI:9.60%-10.25%) subjects had at least one indicator of kidney damage. Age, female, diabetes mellitus, hypertension, and hyperuricemia were independently associated with CKD. ConclusionsThe prevalence of chronic kidney disease is 9.92% in adult population receiving body check from urban area of Hefei, Anhui. Independent risk factors associated with CKD are age, female, diabetes mellitus, hypertension, and hyperoricemia.

ObjectiveTo evaluate the applicability of modified formulas based on plasma creatinine levels in Chinese patients with chronic kidney disease (CKD). MethodsA total of 327 CKD patients were investigated. Glomerular filtration rate (GFR) was estimated with Chinese equations and Ruijin equation. The accuracy of estimated GFR was compared with 99mTc-DTPA-GFR (sGFR) in CKD patients. ResultsBland-Ahman analysis demonstrated that Ruijin equation was more consistent with sGFR than the other equations. But all the equations were not well consistent with sGFR. Linear regression showed that the slopes of Ruijin equation and MDRD-1 equation were closer to the identical line. 15%, 30% and 50% accuracy of Ruijin equation were higher than the other equations. But 30% accuracy of Ruijin equation was still less than 70%. When the accuracy of estimated GFRs was compared with sGFR in different stages of CKD, GFR estimated by Ruijin equation showed good results. ConclusionsWhen plasma creatinine is checked with enzymatic method, modified GFR estimation equations may show great bias in Chinese CKD patients. More clinical trails should be carried out to evaluate and identify the application of modified GFR estimation equations in Chinese patients with CKD.

ObjectiveTo investigate the effects of losartan on angiotensin (Ang)Ⅱ-induced the generation of oxidative stress and expression of transforming growth factor β1(TGF-β1) in rat proximal tubular epithelial cells and to explore its underlying mechanism. MethodsNRK-52E cells, a rat proximal tubular epithelial cell line, were applied to explore the antioxidationand antifibrosis of losartan. The expression of three subunits of nicotinamide-adenine dinucleotide phosphate (NADPH) oxidase, including p47phox, Nox-4, p22phox, and TGF-β1 were determined by real-time RT-PCR and/or Western blot. The generation of reactive oxygen species (ROS) was measured by DCF fluorescence analysis. Superoxide dismutase (SOD) in the supernatant was measured by colorimetric method. Results10-7 mol/L Ang Ⅱ up-regulated p22prox, p47phox and Nox-4 mRNA and protein expression, and the mRNA increased by 5.57-fold, 5.55-fold and 9.41-fold at 24 h (P<0.01, respectively) and the protein increased by 4.53-fold, 4.17-fold and 6.50-fold at 24 h (P<0.01, respectively) as compared with control. Losartan greatly reduced the mRNA elevation of p22prox, p47phox and Nox-4 by 2.71-fold, 2.18-fold and 5.23-fold (P<0.01, respectively) and reduced the protein elevation by 3.20-fold, 2.30-fold and 4.30-fold (P<0.01, respectively) as compared with control. Losartan also inhibited ROS generation induced by Ang Ⅱ in rat proximal tubular epithelial cells. SOD level in the supernatant was markedly decreased after Ang Ⅱ stimulation, while losartan could increase SOD levels (P<0.01). Furthermore, losartan signficantly inhibited Ang Ⅱ-induced TGF-β1 mRNA up-regulation by 64% (P<0.01). ConclusionsLosartan acts as an anti-oxidative and anti-fibrotic agent via the mechanisms of blocking NADPH oxidase-dependent oxidative stress and inhibiting TGF-β1 expression.

ObjectiveTo investigate the effects and molecular mechanism of endoplasmic reticalam stress (ERS) on albumin-induced apoptosis in renal proximal tubular cells (HKCs). MethodsWestern blot was performed to detect the relationship of the expression of glucose-regulated protein 78 (GRF78) and CCAAT/enhancer-binding protein-homologous protein (CHOP) with the action time and concentration of haman serum albumin (HSA). Expression levels of CHPO mRNA and protein in HKCs after CHOP siRNA transfection were examined by real-time fluorescence quantitative PCR and Western blot respectively. Annexin-V-FITC and PI doable staining cytometry was used to detect the apoptosis of HKCs induced by HSA and influenced by CHOP siRNA. Results(1)After HKCs were stimulatde by 0, 5, 10, 20 g/L albumin for 24 hours respectively, the expression of GRP78, CHOP and HKCs apoptosis were increased with the albumin concentration (P<0.01). After HKCs were stimulated by 20 g/L albumin for 0, 6, 12, 24, 36 hours respectively, the expression of GRP78 was up-regulated at 6-hour, while CHOP and HKCs apoptosis were increased at 12-hour, and significant differences were found among groups (P<0.01). (2) CHOP siRNA significantly inhibited albumin-induced HKC CHOP mRNA and protein expression, as well as HKC apoptosis (P<0.01). ConclusionsRenal tubular cells exposed to high protein load result in EBS. ERS may subsequently lead to tubular damage by activation of pro-apoptosis factor CHOP.

ObjectiveTo investigate the clinical application of tacrulimus (TAC, FK506) in children with primary nephrotic syndrome (NS). MethodsSixty-five primary NS children received routine or decreased-dosage glucocorticosteroid according to clinical NS types after hospitalization. At the same time, TAC was given orally with the dosage of 0.1 to 0.15 mg/kg, once every 12 hours, for 6 to 24 months. And the serum concentration of TAC was monitored during the course. ResultsAfter the treatment of TAC for 1 to 2 months, 65 patients were recovered with gradually reduced urinary protein, rapidly increased serum albumin, and improvement of cholesterol and triglycerides. Total remission rate was 83.1% and onset time was 7 to 54 days. Twelve cases experienced recurrence. Increased CD4, as well as 3/3 or 3/1 TAC genotype, indicated higher remission rate. Various pathological types had different remission rates or ratio, which were as follows: minimal change nephropathy (96.4%), mesangial proliferative glomendonephritis (90.0%), membranous nephropathy (2/3), membranous proliferative glomerulonephritis (3/5), focal segmental glomerulosclerosis (4/9). The patients would recover in the course of treatment under the conditions of TAC initial dose as 0.1 to 0.15 mg /kg per 12 hours and controlled serum concentration as 5 to 10 g/L. During the treatment, 12 cases appeared gastrointestinal symptoms, mainly as anorexia, nausea and vomiting, 1 abdominal pain, 2 headache, 1 tremor, 1 paresthesia, 3 insomnia, 4 transient increased Scr, 8 slightly increased NAG, 6 increased C3 and α-2 macroglobulin. The symptoms disappeared within one week or after stopping TAC. ConclusionsTAC is effective in primary NS children, even with abnormal liver function or tuberculosis infection. TAC can also be a substitute to cyclosporine A.