Meichu Cheng

HMGB1 Enhances the AGE-Induced Expression of CTGF and TGF-β via RAGE-Dependent Signaling in Renal Tubular Epithelial Cells

Background/Aims: Advanced glycation end products (AGEs) induce epithelial mesenchymal transition (EMT) in renal proximal tubular epithelial cells (PTECs) by promoting the two EMT regulators, transforming growth factor beta (TGF-β) and connective tissue growth factor (CTGF). However, the exact signaling mechanism remains largely unclear. Methods: We investigated the promotion to high mobility group box 1 (HMGB1) in renal tubular epithelial HK-2 cells by AGE-BSA with quantitative PCR and western blot assay, and then determined the regulatory role of HMGB1 in the AGE-BSA-induced CTGF and TGF-β. In addition, the dependence of the receptor of advanced glycation end products (RAGE) was also examined in the CTGF and TGF-β promotion by AGEs and HMGB1 in HK-2 cells using the RNAi method. Results: It was demonstrated that AGEs induced translocation and release of HMGB1 from tubular epithelial HK-2 cells, and the released HMGB1 enhanced the promotion to CTGF and TGF-β by AGEs in HK-2 cells. On the other side, the HMGB1 knockdown by siRNA attenuated the AGE-BSA-induced expression of TGF-β. Moreover, the CTGF and TGF-β promotion in HK-2 cells by AGEs and HMGB1 was RAGE-dependent. Conclusion: Our results indicated that AGEs induced HMGB-1 and promoted the CTGF and TGF-β in renal epithelial HK-2 cells RAGE-dependently. And there was a synergism between AGEs and HMGB1 in the RAGE signaling activation. The in vitro data suggested that the AGE-RAGE and HMGB-1-RAGE signaling might play an important role in the promotion of CTGF and TGF-β in the renal fibrosis process of diabetic nephropathy.

Atherosclerosis is associated with plasminogen activator inhibitor type‐1 in chronic haemodialysis patients

Aim:  The aim of the present report was to investigate the probable association of circulating levels of PAI‐1 and expression of PAI‐1 in internal iliac artery walls with atherosclerotic disease in chronic haemodialysis (HD) patients.

RISK FACTORS FOR MORTALITY IN CHINESE PATIENTS ON CONTINUOUS AMBULATORY PERITONEAL DIALYSIS

♦ Objective: The intent of this study was to evaluate the clinical outcome and risk factors affecting mortality of the continuous ambulatory peritoneal dialysis (CAPD) patients in a single peritoneal dialysis (PD) center over a period of 10 years. ♦ Patients and methods: We retrospectively analyzed patients on PD from June 2001 to June 2011. The clinical and biochemical data were collected from the medical records. Clinical variables included gender, age at the start of PD, smoking status, body mass index (BMI), cause of end-stage renal disease (ESRD), presence of diabetes mellitus and blood pressure. Biochemical variables included hemoglobin, urine volume, residual renal function (RRF), serum albumin, blood urea nitrogen (BUN), creatinine, total cholesterol, triglyceride, comorbidities, and outcomes. Survival curves were made by the Kaplan-Meier method. Univariate and multivariate analyses to identify mortality risk factors were performed using the Cox proportional hazard regression model. ♦ Results: A total of 421 patients were enrolled, 269 of whom were male (63.9%). The mean age at the start of PD was 57.9 ± 14.8 years. Chronic glomerulonephritis was the most common cause of ESRD (39.4%). Estimation of patient survival by Kaplan-Meier was 92.5%, 80.2%, 74.4%, and 55.7% at 1, 3, 5, and 10 years, respectively. Patient survival was associated with age (hazard ratio [HR]: 1.641 [1.027 – 2.622], p = 0.038), cardiovascular disease (HR: 1.731 [1.08 – 2.774], p = 0.023), hypertriglyceridemia (HR: 1.782 [1.11 – 2.858], p = 0.017) in the Cox proportional hazards model analysis. Estimation of technique survival by Kaplan-Meier was 86.7%, 68.8%, 55.7%, and 37.4% at 1, 3, 5, and 10 years, respectively. In the Cox proportional hazards model analysis, age (HR: 1.672 [1.176 – 2.377], p = 0.004) and hypertriglyceridemia (HR: 1.511 [1.050 – 2.174], p = 0.026) predicted technique failure. ♦ Conclusion: The PD patients in our center exhibited comparable or even superior patient survival and technical survival rates, compared with reports from other centers in China and other countries.

Functional and structural alterations of peritoneum and secretion of fibrotic cytokines in rats caused by high glucose peritoneal dialysis solutions.

Abstract Objective: To determine functional and structural alterations of peritoneum and fibrotic cytokines expression in peritoneal dialysis (PD) rats. Methods: 28 Sprague–Dawley (S-D) rats were randomly divided into four groups and dialyzed with various solutions daily for four weeks: (1) no solution (CON group), (2) 0.9% Saline solution (NS group), (3) 1.5% Dianeal (LG group), (4) 4.25% Dianeal (HG group). Peritoneal equilibration tests, ultrafiltration function and effluent protein quantification were measured. Peritoneum morphology was studied and immunohistochemistry were performed for detection of transforming growth factor β1 (TGF-β1), connective tissue growth factor (CTGF), and fibronectin (FN) proteins. Reverse transcriptional-polymerase chain reaction was used to analyze the expression of TGF-β1, CTGF mRNA. Results: Administration of 4.25% Dianeal caused functional and structural changes of peritoneum, including protein loss through the transport process, decrease of peritoneal solute transport rate and ultrafiltration capacity. The collagen of peritoneum in the HG group was thicker than the other groups. The levels of CTGF, TGF-β1, and FN proteins were significantly the highest in the HG group, followed by the LG group. The liner correlation analysis showed positive correlations between the levels of CTGF, TGF-β1, and FN proteins and the collagen thickness. The expression of TGF-β1 and CTGF mRNA in the HG group were significantly higher than those in the other groups and were indicated positive correlation. Conclusion: Using high glucose peritoneal dialysis solutions in rats may not only lead to processing of peritoneal fibrosis, which is promoted by ectopic expression of TGF-β1, but also increase the expression of CTGF. CTGF is an important fibrotic media of peritoneal fibrosis in PD rats.

Hookworm Infection Caused Acute Intestinal Bleeding Diagnosed by Capsule: A Case Report and Literature Review

Hookworm infections are rare causes of acute gastrointestinal bleeding. We report a middle aged man with primary nephrotic syndrome and pulmonary embolism. During the treatment with steroids and anticoagulants, the patient presented acute massive hemorrhage of the gastrointestinal tract. The results of gastroscopy showed red worms in the duodenum. Colonoscopy and CT angiogram of abdomen were unremarkable. Capsule endoscopy revealed fresh blood and multiple hookworms in the jejunum and ileum. Hookworms caused the acute intestinal bleeding. The patient responded well to albendazole. Hematochezia was markedly ameliorated after eliminating the parasites. Hence, hookworm infection should be considered in the differential diagnosis of a patient with obscure gastrointestinal bleeding. Capsule endoscopy may offer a better means of diagnosis for intestinal hookworm infections.

Greater omentum folding in the open surgical placement of peritoneal dialysis catheters: a randomized controlled study and systemic review

BACKGROUND Mechanical catheter dysfunction caused by omentum entrapment remains a major complication of peritoneal dialysis (PD) therapy. The purpose of this study was to determine the outcomes of omentum folding at the time of primary open catheter insertion. METHODS From March 2008 to December 2012, a total of 67 PD subjects were enrolled in the study and randomly assigned to receive either regular open insertion (ROI group, n = 33) or open insertion with omentum folding (OIOF group, n = 34). The primary outcome was defined as PD catheter tip migration with dysfunction. A systematic review was performed to analyze the outcomes of omentum management in PD catheter implantation, based on published data from 1990 to 2013. RESULTS There was no statistical difference in baseline patient characteristics between the ROI and OIOF groups. Nine (27.3%) patients in the ROI group presented with catheter malposition in the late stage (>60 days) of the study, significantly more than in the OIOF group (two; 5.9%) (P = 0.049). Significant differences in catheter survival rate between the two groups were observed in the late stage (P = 0.030) and over the entire study period (P = 0.028). A higher incidence of irreversible catheter dysfunction was shown in the ROI group (15.2%), whereas none occurred in the OIOF group (P = 0.031). No statistical difference was determined in other catheter-related complications or patient survival rate. There were no statistical differences in peritoneal transport characteristics or dialysis adequacy between the two groups upon evaluation at 3, 6 and 12 months. Systemic review of current publications suggested that PD catheter placement with omentum management could lead to less irreversible catheter dysfunction and improved outcome of catheter survival. CONCLUSIONS Our data suggest that omentum folding at the initial time of open catheter placement can significantly reduce the risk of catheter tip migration with dysfunction and improve the outcome of the PD technique.