No abstract

Elevated serum-soluble urokinase receptor (suPAR) levels have been described in patients with focal segmental glomerulosclerosis (FSGS) in several different cohorts. However, it remains unclear whether this is the case for Japanese patients and whether circulating suPAR can be clinically useful as a diagnostic marker. To determine this, we measured serum suPAR levels in 69 Japanese patients with biopsy-proven glomerular diseases in a cross-sectional manner. The serum suPAR levels showed a significant inverse correlation with renal function by univariate (R(2) of 0.242) and multivariate (β=0.226) analyses. Even after excluding patients with renal dysfunction, no significant difference in the suPAR levels was detected among the groups. Receiver operating characteristic analysis and measures of the diagnostic test performance showed that suPAR was not a useful parameter for differentiating FSGS from the other glomerular diseases (AUC-ROC: 0.621), although a small subgroup analysis showed that patients with FSGS, treated with steroids and/or immunosuppressants, had significantly lower suPAR levels. Patients with ANCA-associated glomerulonephritis had significantly higher levels of suPAR compared with the other disease groups, which may be owing to their lower renal function and systemic inflammation. Thus, suPAR levels are significantly affected by renal function and have little diagnostic value even in patients with normal renal function.

Chronic kidney disease (CKD) is recognized as an irreversible reduction of functional nephrons and leads to an increased risk of various pathological conditions, including cardiovascular disease and neurological disorders, such as coronary artery calcification, hypertension, and stroke. In addition, CKD patients have impaired immunity against bacteria and viruses. Conversely, kidney transplantation (KT) is performed for patients with end-stage renal disease as a renal replacement therapy. Although kidney function is almost normalized by KT, immunosuppressive therapy is essential to maintain kidney allograft function and to prevent rejection. However, these patients are more susceptible to infection due to the immunosuppressive therapy required to maintain kidney allograft function. Thus, both CKD and KT present disadvantages in terms of suppression of immune function. Periodontal disease is defined as a chronic infection and inflammation of oral and periodontal tissues. Periodontal disease is characterized by the destruction of connective tissues of the periodontium and alveolar bone, which may lead to not only local symptoms but also systemic diseases, such as cardiovascular diseases, diabetes, liver disease, chronic obstructive pulmonary disease, and several types of cancer. In addition, the prevalence and severity of periodontal disease are significantly associated with mortality. Many researchers pay special attention to the pathological roles and clinical impact of periodontal disease in patients with CKD or KT. In this review, we provide information regarding important modulators of periodontal disease to better understand the relationship between periodontal disease and CKD and/or KT. Furthermore; we evaluate the impact of periodontal disease on various pathological conditions in patients with CKD and KT. Moreover, pathogens of periodontal disease common to CKD and KT are also discussed. Finally, we examine the importance of periodontal care in these patients. Thus, this review provides a comprehensive overview of the pathological roles and clinical significance of periodontal disease in patients with CKD and KT.

Background/Aim: Unilateral ureteral obstruction (UUO) is a well-established model for tubulointerstitial fibrosis. During the progression of tubulointerstitial fibrosis, upregulation of collagen synthesis and subsequent accumulation of collagen were observed in the tubulointerstitial area. Heat shock protein 47 (HSP47) is a collagen-specific molecular chaperone and plays an essential role in regulating collagen synthesis. We designed small interfering RNA (siRNA) sequences for HSP47 mRNA to examine whether HSP47 is involved in the progression of renal tubulointerstitial fibrosis in a mouse UUO model. Methods: The HSP47 siRNA was injected once via the ureter at the time of UUO preparation. We also applied a new gene delivery system for siRNA using cationized gelatin microspheres. The kidneys were harvested 7 and 14 days after UUO. The HSP47 and type I, III, and IV collagen expression levels were analyzed by immunohistochemistry and Western blotting. Results: Seven days after UUO, the expression levels of HSP47 and type I, III, and IV collagens were markedly upregulated in obstructed kidneys or green fluorescent protein siRNA treated obstructed kidneys. HSP47 siRNA injection significantly reduced the protein expression levels and significantly diminished the accompanying interstitial fibrosis. Moreover, cationized gelatin microspheres as a delivery system enhanced and lengthened the antifibrotic effect of HSP47 siRNA. Conclusions: Our results indicate that HSP47 is a candidate target for the prevention of tubulointerstitial fibrosis and that selective blockade of the HSP47 expression by using siRNA could be a potentially useful therapeutic approach for patients with renal disease.

Objective. Kidney podocytes and their slit diaphragms prevent urinary protein loss. T cells from patients with systemic lupus erythematosus display increased expression of calcium/calmodulin-dependent protein kinase IV (CaMKIV). The present study was undertaken to investigate the role of CaMKIV in podocyte function in lupus nephritis (LN). Methods. We treated kidney podocytes with IgG derived from healthy individuals or patients with LN and then analyzed gene expression using a DNA microarray. The localization of IgG in podocytes was analyzed by immunofluorescence staining, with or without silencing of neonatal Fc receptor (FcRn). In addition, we silenced CAMK4 in podocytes and analyzed the expression of selected genes. We also examined the expression of CD86 in kidney podocytes from MRL/lpr, MRL/lpr.camkiv−/−, and MRL/MPJ mice by in situ hybridization. Results. We found that exposure of podocytes to IgG resulted in entry of IgG into the cytoplasm. IgG entered podocytes via the FcRn because less IgG was found in the cytoplasm of podocytes treated with FcRn small interfering RNA. DNA microarray studies of podocytes exposed to LN-derived IgG revealed up-regulation of genes related to the activation of immune cells or podocyte damage. Interestingly, CD86 expression decreased after silencing CAMK4 in podocytes. Also, in situ hybridization experiments showed that the expression of CD86 was reduced in podocytes from MRL/lpr.camkiv−/− mice. Conclusion. LN-derived IgG enters podocytes and up-regulates CAMK4, which is followed by increased expression of genes known to be linked to podocyte damage and T cell activation. Targeted inhibition of CAMK4 in podocytes may prove to be clinically useful in patients with LN.

Chronic kidney disease (CKD) is characterized by kidney damage with proteinuria, hematuria, and progressive loss of kidney function. The final stage of CKD is known as end-stage renal disease, which usually indicates that approximately 90% of normal renal function is lost, and necessitates renal replacement therapy for survival. The most widespread renal replacement therapy is dialysis, which includes peritoneal dialysis (PD) and hemodialysis (HD). However, despite the development of novel medical instruments and agents, both dialysis procedures have complications and disadvantages, such as cardiovascular disease due to excessive blood fluid and infections caused by impaired immunity. Periodontal disease is chronic inflammation induced by various pathogens and its frequency and severity in patients undergoing dialysis are higher compared to those in healthy individuals. Therefore, several investigators have paid special attention to the impact of periodontal disease on inflammation-, nutrient-, and bone metabolism-related markers; the immune system; and complications in patients undergoing dialysis. Furthermore, the influence of diabetes on the prevalence and severity of manifestations of periodontal disease, and the properties of saliva in HD patients with periodontitis have been reported. Conversely, there are few reviews discussing periodontal disease in patients with dialysis. In this review, we discuss the available studies and review the pathological roles and clinical significance of periodontal disease in patients receiving PD or HD. In addition, this review underlines the importance of oral health and adequate periodontal treatment to maintain quality of life and prolong survival in these patients.

Long-term peritoneal dialysis (PD) leads to histological changes in the peritoneal membrane.Angiogenesis and inflammation caused by glucose degradation products (GDPs) play crucial roles in peritoneal fibrosis. One such GDP is methylglyoxal (MGO), which enhances the formation of advanced glycation end products (AGEs). AGEs bind to their receptor (RAGE) and activate nuclear factor-B (NF-B), which is a key regulator of angiogenesis and inflammation. Recent studies have indicated that (-)-epigallocatechin gallate (EGCG), a tea polyphenol, inhibits angiogenesis and inflammation. Here, we examined whether EGCG suppresses peritoneal fibrosis in mice.Based on preliminary examination, 2 mL of 40 mM MGO or PD fluid was injected intraperitoneally and EGCG (50 mg/kg) or saline was injected subcutaneously for 3 weeks.In comparison to PD fluid + saline-treated mice, the peritoneal tissues of MGO + salinetreated mice showed marked thickening of the submesothelial compact zone. In the submesothelial compact zone of the MGO + saline-treated mice, CD31-positive vessels and vascular endothelial growth factor-positive cells were significantly increased, as were inflammation, F4/80-positive macrophages, and monocyte chemotactic protein-1. Moreover, 8-hydroxydeoxyguanosine, a marker of reactive oxygen species, and NF-B, determined by 3 Southwestern histochemistry, in the submesothelial compact zone were also increased in MGO + saline-treated mice. These changes were attenuated in MGO + EGCG-treated mice.We demonstrated that EGCG treatment suppresses peritoneal fibrosis via inhibition of NF-B. Furthermore, EGCG inhibits reactive oxygen species production. The results of this study indicate that EGCG is a potentially novel candidate for the treatment of peritoneal fibrosis.

Fabry disease-a genetic disorder characterized by the accumulation of globotriaosylceramide in cell lysosomes resulting from an X-linked deficiency of α-galactosidase A activity-presents with multiorgan manifestations, including progressive renal disease. Recently, its prevalence has been reported to be higher in hemodialysis (HD) patients than in the general population. We, therefore, examined patients on maintenance dialysis living in the Nagasaki Prefecture, Japan, to clarify the prevalence of Fabry disease. We screened 933 patients on maintenance dialysis, who were residents of Nagasaki Prefecture in Japan, for α-galactosidase A activity using a dried blood spot on filter paper. Patients with low α-galactosidase A activity were clinically assessed; subsequently, genetic analysis of the α-Galactosidase A gene (MIM:30064) was performed in these patients. Of the 933 patients, 55 had low α-galactosidase A activity; of these, one male and two females had α-Galactosidase A mutations. The prevalence of Fabry disease was thus 0.32%, which was similar to that reported previously. However, one mutation was newly identified, while the E66Q mutation observed in two patients was as previously identified. These two patients with the E66Q mutation were excluded because of the possibility of polymorphism; the prevalence of Fabry disease in the HD population was finally calculated to be 0.11%. The prevalence of Fabry disease in patients on maintenance dialysis living in Nagasaki Prefecture was 0.32%. Dried blood spot screening was considered as a simple and effective method for screening patients on maintenance dialysis for Fabry disease.