OBJECTIVES: To investigate the inhibitory effect of Danshen Injection on endothelial-mesenchymal transition (EndMT) induced by peritoneal dialysis fluid in HMrSV5 cells and the role of the TGF‑β/Smad signaling pathway in mediating this effect. METHODS: HMrSV5 cells cultured in 40% peritoneal dialysis solution for 72 h to induce EndMT were treated with 0.05%, 0.1% and 0.5% Danshen Injection. CCK-8 assay was used to assess the changes in viability of the treated cells, and the levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β), and vascular endothelial growth factor (VEGF) in the cell supernatant were detected using ELISA; Western blotting was performed to detect the protein expressions of E-cadherin, α-smooth muscle actin (α-SMA), p-Smad 2/3, and Smad 7 in the cells. RESULTS: Culture in 40% peritoneal dialysis fluid for 72 induced significant EndMT in HMrSV5 cells, which exhibited obviously lowered cell viability. Danshen Injection within the concentration range of 0.025%-1.5% did not significantly affect the viability of the cells. Exposure of HMrSV5 cells to peritoneal dialysis fluid for 72 h significantly increased the production of IL-6, TNF‑α, TGF‑β and VEGF, upregulated the protein expressions of α‑SMA and p-Smad 2/3, and lowered the expressions of E-cadherin and Smad7 proteins. Treatment of the exposed cells with Danshen injection significantly increased cell viability and cellular expressions of E-cadherin and Smad 7 proteins and reduced the production of IL-6, TNF-α, TGF-β and VEGF and the protein expressions of α‑SMA and p-Smad 2/3. CONCLUSIONS Danshen Injection can suppress peritoneal dialysis fluid-induced EndMT in HMrSV5 cells possibly by regulating the TGF-β/Smad signaling pathway.
Signal Transduction/drug effects* ; Drugs, Chinese Herbal/pharmacology* ; Transforming Growth Factor beta/metabolism* ; Humans ; Peritoneal Dialysis/adverse effects* ; Salvia miltiorrhiza ; Epithelial-Mesenchymal Transition/drug effects* ; Smad Proteins/metabolism* ; Vascular Endothelial Growth Factor A/metabolism* ; Cell Line ; Tumor Necrosis Factor-alpha/metabolism* ; Interleukin-6/metabolism* ; Cadherins/metabolism* ; Actins/metabolism* ; Dialysis Solutions ; Endothelial-Mesenchymal Transition

To investigate the role of glucose transporter 1 (GLUT1) and sodium-glucose cotransporter 1 (SGLT1) in high glucose dialysate-induced peritoneal fibrosis.Thirty six male SD rats were randomly divided into 6 groups (6 in each):normal control group, sham operation group, peritoneal dialysis group (PD group), PD+phloretin group (PD+T group), PD+phlorizin group (PD+Z group), PD+phloretin+phlorizin group (PD+T+Z group). Rat model of uraemia was established using 5/6 nephrotomy, and 2.5% dextrose peritoneal dialysis solution was used in peritoneal dialysis. Peritoneal equilibration test was performed 24 h after dialysis to evaluate transport function of peritoneum in rats; HE staining was used to observe the morphology of peritoneal tissue; and immunohistochemistry was used to detect the expression of GLUT1, SGLT1, TGF-β1 and connective tissue growth factor (CTGF) in peritoneum. Human peritoneal microvascular endothelial cells (HPECs) were divided into 5 groups:normal control group, peritoneal dialysis group (PD group), PD+phloretin group (PD+T group), PD+phlorezin group (PD+Z group), and PD+phloretin+phlorezin group (PD+T+Z group). Real time PCR and Western blotting were used to detect mRNA and protein expressions of GLUT1, SGLT1, TGF-β1, CTGF in peritoneal membrane and HPECs., compared with sham operation group, rats in PD group had thickened peritoneum, higher ultrafiltration volume, and the mRNA and protein expressions of GLUT1, SGLT1, CTGF, TGF-β1 were significantly increased (all<0.05); compared with PD group, thickened peritoneum was attenuated, and the mRNA and protein expressions of GLUT1, SGLT1, CTGF, TGF-β1 were significantly decreased in PD+T, PD+Z and PD+T+Z groups (all<0.05). Pearson's correlation analysis showed that the expressions of GLUT1, SGLT1 in peritoneum were positively correlated with the expressions of TGF-β1 and CTGF (all<0.05)., the mRNA and protein expressions of GLUT1, SGLT1, TGF-β1, CTGF were significantly increased in HPECs of peritoneal dialysis group (all<0.05), and those in PD+T, PD+Z, and PD+T+Z groups were decreased (all<0.05). Pearson's correlation analysis showed that the expressions of GLUT1, SGLT1 in HPECs were positively correlated with the expressions of TGF-β1 and CTGF (all<0.05).High glucose peritoneal dialysis fluid may promote peritoneal fibrosis by upregulating the expressions of GLUT1 and SGLT1.
Animals ; Cells, Cultured ; Connective Tissue Growth Factor ; analysis ; drug effects ; Dialysis Solutions ; adverse effects ; chemistry ; pharmacology ; Gene Expression Regulation ; drug effects ; Glucose ; adverse effects ; pharmacology ; Glucose Transporter Type 1 ; analysis ; drug effects ; physiology ; Hemodiafiltration ; adverse effects ; methods ; Humans ; Male ; Peritoneal Dialysis ; adverse effects ; methods ; Peritoneal Fibrosis ; chemically induced ; genetics ; physiopathology ; Peritoneum ; chemistry ; drug effects ; pathology ; Phloretin ; Phlorhizin ; RNA, Messenger ; Rats ; Rats, Sprague-Dawley ; Sodium-Glucose Transporter 1 ; analysis ; drug effects ; physiology ; Transforming Growth Factor beta1 ; analysis ; drug effects ; Uremia ; chemically induced

OBJECTIVE: To investigate the mechanism of mitochondrial oxidative injury induced by high glucose peritoneal dialysis solution (PDS) and the protective effect of peroxisome proliferator activated receptor gamma coactivator 1-alpha (PGC-1α) in the mitochondria of human peritoneal mesothelial cells (HPMC) in the high glucose ambience. METHODS: HPMC was cultured in a PDS containing 1.5%, 2.5% and 4.25% glucose for 24 hours. Western blot analysis was used to detect PGC-1α expression. MitoSOX? Red staining, respiratory chain complexes and antioxidant enzyme activities were determined. RESULTS: The activities of respiratory chain complex III and antioxidant enzymes decreased significantly in a concentration- and time-dependent manner, along with the increased production of mitochondrial reactive oxygen species (ROS) and cellular apoptosis. In addition, protein expression of PGC-1α was also decreased in the high glucose PDS ambience. CONCLUSION High glucose PDS might inhibit PGC-1α expression, resulting in the inhibition of mitochondrial function and increase of mitochondrial ROS and cellular apoptosis.
Apoptosis ; Dialysis Solutions ; adverse effects ; Epithelial Cells ; pathology ; Glucose ; adverse effects ; Humans ; Mitochondria ; metabolism ; pathology ; Oxidative Stress ; Peritoneal Dialysis ; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha ; Reactive Oxygen Species ; Transcription Factors ; metabolism

OBJECTIVE: To investigate the expression of galectin-1 with the stimulation of peritoneal dialysis solution (PDS) and its role in the epithelial-to-mesenchymal transition (EMT) in human peritoneal mesothelial cells (HPMCs). METHODS: HPMCs were stimulated with PDS containing different concentrations of high glucose (1.5%, 2.5%, and 4.25%). After 24 h, mRNA and protein expressions of galectin-1,vimentin, and zo-1 were analyzed with real-time PCR and Western blot, respectively. Liposome transfected siRNA technique was used to knock down the expression of galectin-1 and the effect of galectin-1 siRNA on the EMT of HPMCs was also observed under 4.25% PDS condition. RESULTS: mRNA expression of galectin-1 in HPMCs increased in PDS groups, especially in group with 4.25% PDS (P<0.05). Protein expression of galectin-1 in HPMCs significantly increased in PDS groups with a dose dependent manner (P<0.05).Expression of vimentin in HPMCs significantly increased in PDS groups, especially in groups of 2.5% PDS and 4.25% PDS (P<0.05), but zo-1 expression markedly decreased (P<0.05). The expression of galectin-1 correlated positively with vimentin (P<0.05) but negatively with zo-1 (P<0.05). Expression of vimentin in groups of 4.25% PDS was markedly inhibited (P<0.05) by galectin-1 siRNA, whereas zo-1 expression was significantly increased (P<0.05). CONCLUSION Galectin-1 can mediate high glucose PDS-induced EMT in HPMCs and may be a new target for the prevention and treatment of peritoneal fibrosis.
Cells, Cultured ; Dialysis Solutions ; pharmacology ; Epithelial Cells ; cytology ; Epithelial-Mesenchymal Transition ; drug effects ; Galectin 1 ; genetics ; metabolism ; Glucose ; pharmacology ; Humans ; Peritoneal Dialysis ; adverse effects ; Peritoneal Fibrosis ; etiology ; Peritoneum ; cytology ; RNA, Messenger ; genetics ; metabolism

BACKGROUND/AIMS: We assessed changes in hemodynamic and arterial stiffness parameters following reductions of dialysate calcium concentrations in patients undergoing hemodialysis. METHODS: In this prospective study, 20 patients on maintenance hemodialysis (10 females, 10 males) with dialysate calcium concentrations of 1.75 mmol/L were enrolled. At the start of the study, the dialysate calcium level was lowered to 1.50 mmol/L. Serial changes in biochemical, hemodynamic, and arterial stiffness parameters, including pulse wave velocity (PWV) and augmentation index (AIx), were assessed every 2 months for 6 months. We also examined changes in the calcification-inhibitory protein, serum fetuin-A. RESULTS: During the 6-month study period, serum total calcium and ionized calcium decreased consistently (9.5 +/- 1.0 to 9.0 +/- 0.7, p = 0.002 vs. 1.3 +/- 0.1 to 1.1 +/- 0.1, p = 0.035). Although no apparent changes in blood pressure were observed, heart-femoral PWW (hf-PWV) and AIx showed significant improvement (p = 0.012, 0.043, respectively). Repeated-measures ANOVA indicated a significant effect of lowering dialysate calcium on hf-PWV (F = 4.58, p = 0.004) and AIx (F = 2.55, p = 0.049). Accompanying the change in serum calcium, serum fetuin-A levels significantly increased (95.8 +/- 45.8 pmol/mL at baseline to 124.9 +/- 82.2 pmol/mL at 6 months, p = 0.043). CONCLUSIONS: Lowering dialysate calcium concentration significantly improved arterial stiffness parameters, which may have been associated with upregulation of serum fetuin-A.
Aged ; Analysis of Variance ; Ankle Brachial Index ; Arteries/*drug effects/physiopathology ; Biological Markers/blood ; Blood Pressure/drug effects ; Calcium/*administration & dosage/adverse effects ; Compliance ; Female ; Hemodialysis Solutions/*administration & dosage/adverse effects/chemistry ; Humans ; Male ; Middle Aged ; Prospective Studies ; Pulsatile Flow/*drug effects ; *Renal Dialysis ; Republic of Korea ; Time Factors ; Treatment Outcome ; alpha-2-HS-Glycoprotein/metabolism

BACKGROUND/AIMS: The aim of this study was to evaluate the peritonitis-causing bacteria detected in peritoneal fluid using a blood culture bottle in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). METHODS: One-hundred and eleven dialysates from 43 patients suspected of peritonitis related to CAPD were retrospectively evaluated between May 2000 and February 2008. In all cases, 5 to 10 mL of dialysate was inoculated into a pair of BacT/Alert blood culture bottles, and 50 mL of centrifuged dialysate was simultaneously inoculated into a solid culture media for conventional culture. The results were compared to those of the conventional culture method. Isolated microorganisms were compared between the two methods. RESULTS: The blood culture method was positive in 78.6% (88 / 112) of dialysate specimens and the conventional culture method in 50% (56 / 112, p < 0.001). CONCLUSIONS: The blood culture method using the BacT/Alert system is useful for culturing dialysates and improves the positive culture rate in patients with suspected peritonitis compared to the conventional culture method.
Culture Media ; Dialysis Solutions ; Gram-Negative Bacterial Infections/*diagnosis/microbiology ; Gram-Positive Bacterial Infections/*diagnosis/microbiology ; Humans ; Kidney Failure, Chronic/*therapy ; Microbiological Techniques/*methods ; Peritoneal Dialysis, Continuous Ambulatory/*adverse effects ; Peritonitis/*diagnosis/microbiology ; Sensitivity and Specificity

OBJECTIVE: To investigate the effect of different concentrations of glucose peritoneal dialysates (PDS) on monolayer transmesothelial electrical resistance (TER) and migration ability of cultured human peritoneal mesothelial cells (HPMCs) to clarify the cause of peritoneal hyperpermeability state and ultrafiltration failure during prolonged peritoneal dialysis. METHODS: HPMCs were cultured in a 1:1 mixture of DMEM and PDS containing 1.5%, 2.5%, and 4.25% glucose. Methyl thiazolyl tetrazolium (MTT) assay and TER were measured to determine the effect of glucose PDS on the proliferation and permeability of human peritoneal mesothelial monolayers, respectively. Wound-healing assay was used to confirm whether glucose could do harm to the migration of cells. RESULTS: Proliferation of HPMCs was significantly suppressed by different glucose concentrations at 24 hours. TER decreased in a time- and concentration-dependent manner after culture with different concentrations of glucose PDS. Cells lost migration in the presence of high glucose after 24 hours, and most cells lost their normal morphology and became detached from plates after 48 hours of wounding. CONCLUSION High glucose in PDS can cause peritoneal damage by suppressing cell proliferation, inducing increase in paracellular permeability of HPMCs and inhibiting cell migration after damage, which may be responsible for peritoneal hyperpermeability and the development of ultrafiltration failure.
Cell Line ; Cell Membrane Permeability ; drug effects ; Cell Movement ; Electric Impedance ; Epithelium ; metabolism ; Glucose ; adverse effects ; metabolism ; Hemodialysis Solutions ; adverse effects ; Humans ; Peritoneal Dialysis ; Peritoneum ; cytology ; drug effects ; metabolism

Cell Line ; Dialysis Solutions ; adverse effects ; Epithelial Cells ; metabolism ; Fibrosis ; Humans ; Peritoneal Dialysis, Continuous Ambulatory ; adverse effects ; Peritoneum ; metabolism ; pathology ; RNA Interference ; RNA, Messenger ; analysis ; RNA, Small Interfering ; pharmacology ; Transforming Growth Factor beta ; antagonists & inhibitors ; genetics ; Transforming Growth Factor beta1

Although activity of iron uptake system (IUS) was thought to play an important role in staphylococcal growth in human peritoneal dialysate (HPD) solution, siderophore production, one of the well-known IUS, was not yet detected directly in HPD solution. Therefore, we tried to detect siderophore production directly in HPD solution by using a newly developed chrome azurol S (CAS) agar diffusion assay and to investigate the effect of IUS activity on bacterial growth in HPD solution. According to the susceptibility test for streptonigrin and the productivity of siderophore in the iron-deficient (ID) medium, Staphylococcus aureus ATCC 6538 strain and Staphylococcus epidermidis clinical isolate had higher IUS activity and grew better than S. aureus ATCC 25923 strain in the ID medium. These bacteria did not grow and produce siderophore in the unused chronic ambulatory peritoneal dialysis solution. However, these bacteria grew and produced siderophore in the HPD solution. Moreover, S. aureus ATCC 25923 strain with lower activity of IUS grew poorly and produced smaller amount of siderophore in HPD compared to S. aureus ATCC 6538 strain and S. epidermidis clinical isolate with higher activity of IUS like in the ID medium. To the best of our knowledge, this is the first report that sidero-phore production is directly detected in the HPD by CAS agar diffusion assay. These results indicated that activity of IUS plays an important role in bacterial growth in the HPD solution and pathogenesis of continuous ambulatory peritoneal dialysis peritonitis.
Biological Assay ; Dialysis Solutions/chemistry* ; Drug Contamination ; Human ; Peritoneal Dialysis, Continuous Ambulatory/adverse effects* ; Siderophores/metabolism* ; Staphylococcus/metabolism*

BACKGROUND: Patients on continuous ambulatory peritoneal dialysis (CAPD) have increased risk of low-turnover bone disease and relative hypoparathyroidism. Recently, it has been believed that magnesium plays an important role in regulating secretion of parathyroid hormone (PTH). The aim of this study was to evaluate the relationship between serum PTH and serum magnesium as a factor increasing the frequency of relative hypoparathyroidism. METHODS: We analyzed the data of 56 patients who had been on CAPD for more than 6 months without any significant problems. No patient had been previously treated with vitamin D or aluminum hydroxide. The patients had used peritoneal dialysate with the magnesium concentration of 0.5 mEq/L. Biochemical parameters, such as BUN, creatinine, alkaline phosphatase bony isoenzyme, total protein, albumin, total calcium, ionized calcium and intact parathyroid hormone level were measured. RESULTS: The mean serum magnesium level was 1.99 +/- 0.36 mEq/L. Among total 56 patients, 15 patients (26.8%) showed hypermagnesemia (serum magnesium > 2.2 mEq/L) and 5 patients (8.9%) showed hypomagnesemia (serum magnesium < 1.6 mEq/L). Among all 56 patients, serum iPTH (intact PTH) level was not correlated with serum magnesium level. However, it was inversely correlated with serum total calcium and ionized calcium levels, respectively (r=-0.365, p=0.006; r=-0.515 p < 0.001). Among 49 patients whose serum iPTH level was less than 300 pg/mL, serum iPTH level was inversely correlated with serum magnesium level (r=-0.295, p=0.039) and inversely correlated with serum total calcium and ionized calcium levels, respectively (r=-0.546, p < 0.001; r=-0.572 p < 0.001). Among 49 patients whose serum iPTH level was less than 300 pg/mL, lower iPTH group (serum iPTH < 120 pg/mL) showed higher serum magnesium level (p=0.037), higher serum total calcium level (p < 0.001) and lower bone isoenzyme of alkaline phosphatase level (p < 0.001) than those of higher iPTH group (120 pg/mL Adult ; Alkaline Phosphatase/blood ; Calcium/blood ; Dialysis Solutions ; Female ; Human ; Kidney Failure, Chronic/complications/therapy ; Magnesium/*blood ; Male ; Middle Age ; Parathyroid Hormones/*blood ; Peritoneal Dialysis, Continuous Ambulatory/*adverse effects/methods ; Phosphates/blood ; Renal Osteodystrophy/etiology