Mechanism of Albuminuria Reduction by Chymase Inhibition in Diabetic Mice.

Chymase has several functions, such as angiotensin II formation, which can promote diabetic kidney disease (DKD). In this study, we evaluated the effect of the chymase inhibitor TY-51469 on DKD in diabetic db/db mice. Diabetic mice were administered TY-51469 (10 mg/kg/day) or placebo for 4 weeks. No significant difference was observed in body weight and fasting blood glucose between TY-51469- and placebo-treated groups. However, a significant reduction in urinary albumin/creatinine ratio was observed in the TY-51469-treated group compared with the placebo-treated group. In the renal extract, chymase activity was significantly higher in placebo-treated mice than in non-diabetic db/m mice, but it was reduced by treatment with TY-51469. Both NADPH oxidase 4 expression and the oxidative stress marker malondialdehyde were significantly augmented in the placebo-treated group, but they were attenuated in the TY-51469-treated group. Significant increases of tumor necrosis factor-α and transforming growth factor-ß mRNA levels in the placebo-treated group were significantly reduced by treatment with TY-51469. Furthermore, the expression of nephrin, which is a podocyte-specific protein, was significantly reduced in the placebo-treated group, but it was restored in the TY-51469-treated group. These findings demonstrated that chymase inhibition reduced albuminuria via attenuation of podocyte injury by oxidative stress.

Possible Roles of Periostin in the Formation of Hemodialysis Vascular Access Stenosis after Polytetrafluoroethylene Graft Implantation in Dogs.

Periostin, a recently found matricellular protein, has been implicated in neointima formation after balloon injury. However, the relationship between periostin and hyperplastic intima formation after PTFE graft implantation is unclear. Under mixed anesthesia, PTFE grafts were implanted between the canine carotid artery and jugular vein, and PTFE graft samples were harvested 1, 2, and 4 months after implantation. Intima formation started on the luminal surface of PTFE grafts at the venous anastomotic region 1 month after implantation. Thereafter, the increase in intimal volume was not only observed in the venous and arterial anastomotic regions, but also in the middle region of the PTFE grafts. In accordance with the increased intimal formation, time-dependent increases in mRNA expressions of periostin and transforming growth factor beta 1 (TGF-ß1), as well as a strong positive correlation between periostin and TGF-ß1, were observed. These findings suggest that periostin may play a very important role in the pathogenesis of hemodialysis vascular access stenosis through the acceleration of intimal formation. Thus, periostin may be a very important therapeutic target for the treatment of vascular access graft dysfunction in hemodialysis patients.

Treatment of secondary hyperparathyroidism in patients on hemodialysis using a novel synthetic peptide calcimimetic, etelcalcetide: a short-term clinical study.

OBJECTIVE: Secondary hyperparathyroidism (SHPT) is a major complication in patients with chronic kidney disease (CKD). SHPT is related to chronic kidney disease-mineral bone disorder, leading to increased morbidity and mortality. Etelcalcetide is intravenously administered at the end of hemodialysis (HD). Etelcalcetide differs from the oral calcimimetic cinacalcet because it reduces gastrointestinal adverse events, thereby improving therapeutic effects. Etelcalcetide has only been approved by the U.S. Food and Drug Administration for several months. Therefore, there have only been a few reports regarding treatment of SHPT using etelcalcetide. This study aimed to evaluate the efficacy of etelcalcetide in patients on HD with SHPT. METHODS: Nine patients on HD (four men and five women, aged 58 ± 10 years) were enrolled in this study. All of the patients received etelcalcetide (5-10 mg, three times a week after HD). The observation period was 4.4 ± 1.0 months. RESULTS: All of the patients showed a significant reduction in serum parathyroid hormone levels during the observation period (-59% ± 20%). No significant adverse effects were observed. CONCLUSIONS: Although this study had an uncontrolled small group and a short observation period, our results suggest that etelcalcetide could be a promising agent for SHPT treatment.

A novel apolipoprotein E mutation, ApoE Osaka (Arg158 Pro), in a dyslipidemic patient with lipoprotein glomerulopathy.

Lipoprotein glomerulopathy (LPG) is a rare disease characterized by the presence of thrombuslike deposition in markedly dilated glomerular capillaries and is often accompanied by an increased serum apolipoprotein E (apoE) level. Several gene mutations of apoE have been reported to be associated with LPG. In the current study, we report an LPG patient with a novel apoE mutation, apoE Osaka. The patient was a 45-year-old man who was hospitalized due to nephrotic syndrome. Light and electron microscopic observations of renal biopsy clearly showed characteristic findings of LPG, including lamellate thrombi in the lumen of dilated glomerular capillaries. His apoE phenotype was apoE3/2 and he had mild dyslipidemia with a mid-band on polyacrylamide gel electrophoresis. It is intriguing that the serum apoE level was within normal limits. We determined the sequence of the apoE gene using direct sequencing of the polymerase chain reaction (PCR) products. ApoE gene analysis showed a nucleotide substitution of G to C at codon 158 of exon 4. This mutation denoted an amino acid substitution of arginine residue for the proline residue at position 158 of apoE. The result of PCR associated with restriction fragment length polymorphism analysis also suggested that this mutation is heterozygous. It is possible that apoE Osaka mutation causes a conformational change of apoE protein and affects the interaction between abnormal apoE-containing lipoproteins and the endothelial cells of glomerular capillaries. The precise mechanism of LPG related with apoE Osaka, however, remains to be elucidated.

Adverse events in therapeutic apheresis: a single center survey of various therapies.

The aim of the study was to review the adverse events associated with various treatment modalities performed in a single apheresis facility. A total of 854 sessions with 10 types of apheresis therapies were performed and 154 (18.0%) adverse events were observed over a four-year period. Of the adverse events, 77 were related to operational problems and another 77 were complications associated with treatment. A transmembranous pressure abnormality constituted more than 80% of the operational problems. Nausea was the most frequent complication, accounting for 19 of the 77 treatment-related events. A total of 26 (16.9%) adverse events occurred in the early stage of the sessions, 40 (26.0%) in the middle stage, and 88 (57.1%) in the late stage. The information in this study can be used to improve the safety and efficacy of apheresis therapy.