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Vasohibin-1 (VASH1) is a unique endogenous inhibitor of angiogenesis that is induced in endothelial cells by pro-angiogenic factors. We previously reported renoprotective effect of adenoviral delivery of VASH1 in diabetic nephropathy model, and herein investigated the potential protective role of endogenous VASH1 by using VASH1-deficient mice. Streptozotocin-induced type 1 diabetic VASH1 heterozygous knockout mice (VASH1+/−) or wild-type diabetic mice were sacrificed 16 weeks after inducing diabetes. In the diabetic VASH1+/− mice, albuminuria were significantly exacerbated compared with the diabetic wild-type littermates, in association with the dysregulated distribution of glomerular slit diaphragm related proteins, nephrin and ZO-1, glomerular basement membrane thickning and reduction of slit diaphragm density. Glomerular monocyte/macrophage infiltration and glomerular nuclear translocation of phosphorylated NF-κB p65 were significantly exacerbated in the diabetic VASH1+/− mice compared with the diabetic wild-type littermates, accompanied by the augmentation of VEGF-A, M1 macrophage-derived MCP-1 and phosphorylation of IκBα, and the decrease of angiopoietin-1/2 ratio and M2 macrophage-derived Arginase-1. The glomerular CD31+ endothelial area was also increased in the diabetic VASH1+/− mice compared with the diabetic-wild type littermates. Furthermore, the renal and glomerular hypertrophy, glomerular accumulation of mesangial matrix and type IV collagen and activation of renal TGF-β1/Smad3 signaling, a key mediator of renal fibrosis, were exacerbated in the diabetic VASH1+/− mice compared with the diabetic wild-type littermates. In conditionally immortalized mouse podocytes cultured under high glucose condition, transfection of VASH1 small interfering RNA (siRNA) resulted in the reduction of nephrin, angiopoietin-1 and ZO-1, and the augmentation of VEGF-A compared with control siRNA. These results suggest that endogenous VASH1 may regulate the development of diabetic renal alterations, partly via direct effects on podocytes, and thus, a strategy to recover VASH1 might potentially lead to the development of a novel therapeutic approach for diabetic nephropathy. [ABSTRACT FROM AUTHOR]

Background: Galectin-9 (Gal-9) induces apoptosis in activated T helper 1 (TH1) cells as a ligand for T cell immunoglobulin mucin-3 (Tim-3). Gal-9 also inhibits the G1 phase cell cycle arrest and hypertrophy in db/db mice, the hallmark of early diabetic nephropathy, by reversing the high glucose-induced up-regulation of cyclin dependent kinase inhibitors such as p27Kip1 and p21Cip1. Methods: We investigated the serum levels of Gal-9 in the patients with type 2 diabetes and various stages of chronic kidney disease (CKD) (n=182). Results: Serum Gal-9 levels in the patients with type 2 diabetes were 131.9 ± 105.4 pg/ml and Log10Gal-9 levels significantly and positively correlated with age (r=0.227, p=0.002), creatinine (r=0.175, p=0.018), urea nitrogen (r=0.162, p=0.028) and osmotic pressure (r=0.187, p=0.014) and negatively correlated with estimated glomerular filtration rate (eGFR) (r=-0.188, p=0.011). Log10Gal-9 levels increased along with the progression of GFR categories of G1 to G4, and they were statistically significant by Jonckheere-Terpstra test (p=0.012). Log10Gal-9 levels remained similar levels in albuminuria stages of A1 to A3. Conclusion: The elevation of serum Gal-9 in the patients with type 2 diabetes is closely linked to GFR and they may be related to the alteration of the immune response and inflammation of the patients with type 2 diabetes and CKD. [ABSTRACT FROM AUTHOR]

Metallothionein (MT) is an intracellular metal-binding, cysteine-rich protein, and is a potent antioxidant that protects cells and tissues from oxidative stress. Although the major isoforms MT-1 and -2 (MT-1/-2) are highly inducible in many tissues, the distribution and role of MT-1/-2 in diabetic nephropathy are poorly understood. In this study, diabetes was induced in adult male rats by streptozotocin, and renal tissues were stained with antibodies for MT-1/-2. MT-1/-2 expression was also evaluated in mProx24 cells, a mouse renal proximal tubular epithelial cell line, stimulated with high glucose medium and pretreated with the antioxidant vitamin E. MT-1/-2 expression was gradually and dramatically increased, mainly in the proximal tubular epithelial cells and to a lesser extent in the podocytes in diabetic rats, but was hardly observed in control rats. MT-1/-2 expression was also increased by high glucose stimulation in mProx24 cells. Because the induction of MT was suppressed by pretreatment with vitamin E, the expression of MT-1/-2 is induced, at least in part, by high glucose-induced oxidative stress. These observations suggest that MT-1/-2 is induced in renal proximal tubular epithelial cells as an antioxidant to protect the kidney from oxidative stress, and may offer a novel therapeutic target against diabetic nephropathy. [ABSTRACT FROM AUTHOR]

Background. Application of icodextrin-based peritoneal dialysis fluid (PDF) provides a potential benefit in patients with diabetes and end-stage renal failure treated with continuous ambulatory peritoneal dialysis (CAPD) because of better ultrafiltration capacity and avoidance of direct glucose exposure. We examined the effect of glucose and icodextrin-based PDF on histological alterations of peritoneal membranes. [ABSTRACT FROM PUBLISHER]

The continuous increase in the number of people requiring dialysis is a major clinical and socioeconomical issue in Japan and other countries. This study was designed to encourage chronic kidney disease (CKD) patients to consult a physician, enhance cooperation between nephrologists and general practices, and prevent the progression of kidney disease. Subjects comprise CKD patients aged between 40 and 74 years consulting a general physician, and patients in CKD stage 3 with proteinuria and diabetes or hypertension. This trial is a stratified open cluster-randomized study with two intervention groups: group A (weak intervention) and group B (strong intervention). We have recruited 49 local medical associations (clusters) in 15 different prefectures, which were classified into four regions (strata) based on the level of increase rate of dialysis patients. The patients in group A clusters were instructed initially to undergo treatment in accordance with the current CKD treatment guide, whereas patients in group B clusters were not only instructed in the same fashion but also received support from an information technology (IT)-based system designed to help achieve the goals of CKD treatment, consultation support centers, and consultations by dietitians visiting the local general practice offices. We assessed the rates of continued consultation, collaboration between general practitioners and nephrologists, and progression of CKD (as expressed by CKD stage). Through this study, filling the evidence-practice gap by facilitating effective communication and supporting general physicians and nephrologists, we will establish a CKD care system and decrease the number of advanced-stage CKD patients. [ABSTRACT FROM AUTHOR]

OBJECTIVE -- Interleukin (IL)-18 is a proinflammatory cytokine secreted from mononuclear cells. Serum concentration of IL-18 is a strong predictor of death in patients with cardiovascular diseases. Recent studies have shown that microinflammation is involved in the pathogenesis of diabetic nephropathy as well as of cardiovascular diseases. This study aimed to test the hypothesis that the serum level of IL-18 is a common predictor of nephropathy and atherosclerosis in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS -- Eighty-two Japanese patients with type 2 diabetes and 55 age- and sex-matched healthy control subjects were enrolled. Patients with renal dysfunction (creatinine clearance < 1 ml/s) were excluded. We assessed clinical parameters and measured serum and urinary IL-18 levels, serum IL-6 levels, carotid intima-media thickness (IMT), and brachial-ankle pulse wave velocity (baPWV) in all patients. Further, we evaluated changes of urinary albumin excretion rate (AER) after 6 months in 76 diabetic patients. RESULTS -- Serum and urinary IL-18 levels were significantly elevated in patients with type 2 diabetes as compared with control subjects (serum IL-18 179 ± 62 vs. 121 ± 55 pg/ml, P < 0.001; urinary IL-18 97 ± 159 vs. 47 ± 54 pg/ml, P = 0.035). Univariate linear regression analysis showed significant positive correlations between serum IL-18 and AER (r [correlation coefficient] = 0.525, P < 0.001), HbA[sub 1c] (r = 0.242, P = 0.029), high-sensitivity C-reactive protein (hs-CRP) (r = 0.240, P = 0.031), and urinary β-2 microglobulin (r = 0.235, P = 0.036). Serum IL-18 levels also correlated positively with carotid IMT (r = 0.225, P = 0.042) and baPWV (r = 0.232, P = 0.040). We also found a significant correlation between urinary IL-18 and AER (r = 0.309, P = 0.005). Multivariate linear regression analysis showed that AER (standard correlation coefficients [BI = 0.405, P < 0.001) and hs-CRP (B = 0.207, P = 0.033) were independently associated with serum IL-18 levels. AER was also independently associated with urinary IL-18 levels (B = 0.295, P = 0.005). Moreover, serum and urinary IL-18 levels correlated positively with AER after 6 months (r = 0.489, P < 0.001 and r = 0.320, P = 0.005) and changes in AER during the follow-up period (r = 0.268, P = 0.018 and r = 0.234, P = 0.042). CONCLUSIONS -- Serum levels of IL-18 might be a predictor of progression of diabetic nephropathy as well as cardiovascular diseases. [ABSTRACT FROM AUTHOR]

In the early stage of diabetic nephropathy (one of the major microvascular complications of diabetes) glomerular hyperfiltration and hypertrophy are observed. It is clinically important to regulate glomerular hypertrophy for preventing glomerulosclerosis. The number of glomerular endothelial cells is known to be increased in diabetic nephropathy associated with enlarged glomerular tufts, suggesting that the mechanism is similar to that of angiogenesis. Tumstatin peptide is an angiogenesis inhibitor derived from type IV collagen and inhibits in vivo neovascularization induced by vascular endothelial growth factor (VEGF), one of the mediators of glomerular hypertrophy in diabetic nephropathy. Here, we show the effect of tumstatin peptide in inhibiting alterations in early diabetic nephropathy. Glomerular hypertrophy, hyperfiltration, and albuminuria were suppressed by tumstatin peptide (1 mg/kg) in streptozotocin-induced diabetic mice. Glomerular matrix expansion, the increase of total glomerular cell number and glomerular endothelial cells (CD31 positive), and monocyte/macrophage accumulation was inhibited by tumstatin peptide. Increase in renal expression of VEGF, flk-1, and angiopoietin-2, an antagonist of angiopoietin-1, was inhibited by tumstatin treatment in diabetic mice. Alteration of glomerular nephrin expression, a podocyte protein crucial for maintaining glomerular filtration barrier, was recovered by tumstatin in diabetic mice. Taken together, these results demonstrate the potential use of antiangiogenic tumstatin peptide as a novel therapeutic agent in early diabetic nephropathy. [ABSTRACT FROM AUTHOR]

Diabetic nephropathy is a leading cause of end-stage renal failure. Several mechanisms, including activation of protein kinase C, advanced glycation end products, and overexpression of transforming growth factor (TGF)-β, are believed to be involved in the pathogenesis of diabetic nephropathy. However, the significance of inflammatory processes in the pathogenesis of diabetic microvascular complications is poorly understood. Accumulation of macrophages and overexpression of leukocyte adhesion molecules and chemokines are prominent in diabetic human kidney tissues. We previously demonstrated that intercellular adhesion molecule (ICAM)-I mediates macrophage infiltration into the diabetic kidney. In the present study, to investigate the role of ICAM-1 in diabetic nephropathy, we induced diabetes in ICAM-1-deficient (ICAM-1[sup -/-]) mice and ICAM-1[sup +/+] mice with streptozotocin and examined the renal pathology over a period of 6 months. The infiltration of macrophages was markedly suppressed in diabetic ICAM-1[sup -/-] mice compared with that of ICAM-1[sup +/+] mice. Urinary albumin excretion, glomerular hypertrophy, and mesangial matrix expansion were significantly lower in diabetic ICAM-1[sup -/-] mice than in diabetic ICAM1[sup +/+] mice. Moreover, expressions of TGF-β and type IV collagen in glomeruli were also suppressed in diabetic ICAM-1[sup -/-] mice. These results suggest that ICAM-1 is critically involved in the pathogenesis of diabetic nephropathy. [ABSTRACT FROM AUTHOR]

Background: Tumor necrosis factor-α (TNF-α) may play an important role in insulin resistance. In this study, we hypothesized that TNF-α produced due to periodontal inflammation synergistically affects insulin resistance as well as TNF-α produced from adipose tissues in insulin-resistant type 2 diabetes patients. Therefore, to understand the effects of antimicrobial periodontal therapy on serum TNF-α concentration and subsequent metabolic control of diabetes, we examined the periodontal and diabetic status on 13 type-2 diabetes patients. Methods: These patients were treated with local minocycline administration in every periodontal pocket around all existing teeth once a week for a month. Before and after treatment, the number of total bacteria in the periodontal pockets and circulating TNF-α concentration were measured and the HbA1c value was assessed. Results: Antimicrobial therapy significantly reduced the number of microorganisms in periodontal pockets (P <0.01). After treatment, the circulating TNF-α level was significantly reduced (P <0.015). The HbA1c value was also reduced significantly (P <0.007). In addition, the 6 patients who were not receiving insulin therapy demonstrated decreased fasting insulin levels (P <0.03), and HOMA-R (P <0.03) indices. The average reduction; in circulating TNF-α concentration and HbA1c value were 0.49 pg/ml and 0.8%, respectively. Conclusion: The results indicate that anti-infectious treatment is effective in improving metabolic control in diabetics, possibly through reduced serum TNF-α and improved insulin resistance. [ABSTRACT FROM AUTHOR]

Background: Type 1 diabetes is caused by a destruction of pancreatic β cells due to autoimmunity. Autoantibody against glutamic acid decarboxylase (GAD) 65 expressed in pancreatic β cells is widely used as a predictive marker for pancreatic destruction. In this study, we hypothesized that if certain cells in periodontal tissues could express GAD, then it may influence GAD antibody titer. Methods: We used: 1) reverse transcription-polymerase chain reaction (PCR) analysis to detect GAD 65 mRNA in various cells; 2) nucleotide sequencing analysis to confirm that amplified PCR product is the gene encoding GAD; and 3) Western blotting to determine the expression of GAD 65 protein in human gingival fibroblasts. Immunohistochemical staining of GAD 65 protein in normal and inflamed gingiva was performed to examine the potential influence of periodontal inflammation on GAD 65 expression. GAD antibody titer in sera of periodontal patients as well as healthy subjects was measured to determine if periodontal patients could develop autoantibody against GAD 65. Results: Cultured human gingival, periodontal, and dermal fibroblasts and mesangial cells expressed GAD mRNA. Nucleotide sequencing analyses confirmed the amplified PCR product as GAD 65. Western immunoblotting analyses and immunohistochemical staining revealed that the GAD 65 protein was expressed in vitro and in vivo. The expression of GAD 65 in inflamed tissue was higher than that in normal tissues. Two of 62 periodontal patients without diabetes showed an increased antibody titer against GAD 65, while none of the systemically healthy subjects showed an increased antibody titer against this antigen. Conclusions: We concluded that periodontal inflammation may result in higher levels of GAD and influence GAD antibody titer, and, hence, affect diabetic diagnosis based upon GAD antibody production. [ABSTRACT FROM AUTHOR]

Apoptosis and extracellular matrix–cell interactions in kidney disease. Extracellular matrix (ECM)–cell interactions have major effects on phenotypic features such as cell growth, differentiation, and gene expression. Apoptosis is an active form of cell death that is crucial for maintaining an appropriate number of cells as well as tissue organization. Recent reports have implied that ECM can influence survival and apoptosis of several cell lineages including glomerular mesangial cells (MC). Numerous glomerular diseases are associated with the expansion of the mesangial ECM, which may eventually produce glomerular scarring. Glomerular cell apoptosis is associated with the deletion of glomerular cells and the accumulation of ECM in the progression of glomerulosclerosis in rat remnant kidney model induced by 5/6 nephrectomy. Our recent study indicated that basement membrane matrix (a model for normal ECM components) prevented cultured MC from undergoing apoptosis after serum deprivation, thus promoting their survival, compared with type I collagen matrix (a model for abnormal ECM components). Inhibition of matrix-derived signals by antisense oligonucleotides against β 1 integrin increased MC apoptosis. Data suggest that the survival and death of MC are regulated by the surrounding ECM through integrin molecules. The mechanism of regulation of MC apoptosis by ECM requires further in vivo study to gain new insight into the treatment of glomerular diseases as well as the pathophysiology of the mesangium. Diabetic nephropathy is characterized by the abnormal ECM accumulation and the phenotypic change of MC. Some speculations on the possible involvement of apoptosis in diabetic nephropathy are also discussed. [ABSTRACT FROM AUTHOR]

The innate immune system includes several classes of pattern recognition receptors (PRRs), including membrane-bound Toll-like receptors (TLRs) and nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs). These receptors detect pathogen-associated molecular patterns (PAMPs) and danger-associated molecular patterns (DAMPs) in the extracellular and intracellular space. Intracellular NLRs constitute inflammasomes, which activate and release caspase-1, IL-1β, and IL-18 thereby initiating an inflammatory response. Systemic and local low-grade inflammation and release of proinflammatory cytokines are implicated in the development and progression of diabetes mellitus and diabetic nephropathy. TLR2, TLR4, and the NLRP3 inflammasome can induce the production of various proinflammatory cytokines and are critically involved in inflammatory responses in pancreatic islets, and in adipose, liver and kidney tissues. This Review describes how innate immune system-driven inflammatory processes can lead to apoptosis, tissue fibrosis, and organ dysfunction resulting in insulin resistance, impaired insulin secretion, and renal failure. We propose that careful targeting of TLR2, TLR4, and NLRP3 signalling pathways could be beneficial for the treatment of diabetes mellitus and diabetic nephropathy. [ABSTRACT FROM AUTHOR]

Abstract: Human acatalasemia may be a risk factor for the development of diabetes mellitus. However, the mechanism by which diabetes is induced is still poorly understood. The impact of catalase deficiency on the onset of diabetes has been studied in homozygous acatalasemic mutant mice or control wild-type mice by intraperitoneal injection of diabetogenic alloxan. The incidence of diabetes was higher in acatalasemic mice treated with a high dose (180 mg/kg body weight) of alloxan. A higher dose of alloxan accelerated severe atrophy of pancreatic islets and induced pancreatic β cell apoptosis in acatalasemic mice in comparison to wild-type mice. Catalase activity remained low in the acatalasemic pancreas without the significant compensatory up-regulation of glutathione peroxidase or superoxide dismutase. Furthermore, daily intraperitoneal injection of angiotensin II type 1 (AT1) receptor antagonist telmisartan (0.1 mg/kg body weight) prevented the development of alloxan-induced hyperglycemia in acatalasemic mice. This study suggests that catalase plays a crucial role in the defense against oxidative-stress-mediated pancreatic β cell death in an alloxan-induced diabetes mouse model. Treatment with telmisartan may prevent the onset of alloxan-induced diabetes even under acatalasemic conditions. [Copyright &y& Elsevier]

Abstract: Background: The presence of metabolic syndrome has been shown to be predictors of cardiovascular morbidity and mortality in patients with type 2 diabetes. In a cross-sectional clinical study, we investigated the association of metabolic syndrome with asymptomatic lacunar strokes and cardiovascular disease (CVD) and we compared its significance with urinary protein markers. Methods: We studied Japanese type 2 diabetes patients (n =233, men=124, women=109). The diagnosis of metabolic syndrome was made according to WHO and International Diabetes Federation (IDF) criteria. Cardiovascular events were recorded and asymptomatic lacunar lesions were evaluated with magnetic resonance imaging (MRI). We also measured urinary levels of albumin, type IV collagen, β2-microglobulin (β2MG), N-acetyl-β-d-glucosaminidase (NAG) and lipocalin-type prostaglandin D synthase (PGDS). Results: The prevalence of metabolic syndrome is 31.3% (IDF) and 52% (WHO) in 233 patients and microalbuminuria was present in 62 subjects (26.6%). Metabolic syndrome (WHO) significantly associated with asymptomatic lacunar lesions (p =0.035, OR=2.854, CI 1.075–7.579), while metabolic syndrome (IDF) or urinary markers failed to associate with presence of asymptomatic lacunar lesions. The presence of metabolic syndrome or microalbuminuria did not show significant association with CVD; however, the elevation of β2MG, NAG and PGDS showed significant association with CVD. By a logistic regression analysis using urinary proteins as independent variables, the presence of higher PGDS excretion independently associated with history of CVD (p =0.025, OR=3.847, CI 1.180–12.545). Conclusions: In type 2 diabetes patients, the elevation of urinary PGDS secretion closely associated with cardiovascular events and may be a supplemental or additional marker to the criteria of metabolic syndrome. [Copyright &y& Elsevier]

A 45-year-old woman with 20-year history of diabetes mellitus was admitted to our hospital because of high fever and abdominal pain. Radical hysterectomy and bilateral pelvic lymphadenectomy had been performed 4 months before admission for invasive cervical cancer. On admission, elastic hard tumors were palpable in the lower abdomen. Laboratory examination showed positive C-reactive protein (CRP), anemia and renal dysfunction. Computed tomography (CT) revealed several lymphocysts in the pelvis. She was diagnosed with infection of pelvic lymphocysts. Since her mother also had diabetes associated with deafness, we examined mitochondrial DNA in leukocytes and detected an A to G transition at the nucleotide position of 3243 (A3243G mutation). She was diagnosed as maternally inherited diabetes mellitus and deafness (MIDD). Puncture of the cysts followed by administration of antibiotics resulted in marked improvement of symptoms and laboratory findings. This is a rare case of pelvic lymphocyst infection in a patient with a mitochondrial disorder. Although the exact mechanism of infection is not clear, MIDD may represent an unusual risk factor for infection, and further investigation is necessary to assess the influence of mitochondrial dysfunction on the immune system. Pelvic lymphocyst infection should be considered in the differential diagnosis of abdominal pain and fever in patients with MIDD after abdominal surgery. [Copyright &y& Elsevier]

Stable prostacyclin analogue, beraprost sodium (BPS) has recently been reported to attenuate glomerular hyperfiltration in diabetic rats, however, the mechanism has been still unknown. We previously reported that overexpression of endothelial cell nitric oxide synthase (ecNOS) in afferent arterioles and glomeruli induce inappropriate dilatation of afferent arterioles and glomerular hyperfiltration through overproduction of nitric oxide in early stage of diabetic nephropathy. In this study, we tested the hypothesis that BPS ameliorates glomerular hyperfiltration through modulating ecNOS expression in diabetic nephropathy. Furthermore, we examined the effects of BPS on the expression of intercellular adhesion molecule-1 (ICAM-1) and macrophage infiltration in diabetic glomeruli, because glomerular hyperfiltration induces the expression of ICAM-1 resulting in macrophage infiltration. Male Sprague–Dawley (SD) rats were administered continuously with BPS for 4 weeks after induction of diabetes by streptozotocin. In diabetic rats, the diameters of afferent arterioles, glomerular volume, creatinine clearance and urinary excretion of albumin and NO2/NO3 were increased as compared with non-diabetic control rats. Treatment with BPS improved these changes. The expression of ecNOS was increased in afferent arterioles and glomeruli in diabetic rats and suppressed by BPS. Prostacyclin receptor was expressed along afferent arterioles. Our results suggest that BPS attenuates glomerular hyperfiltration by modulating ecNOS expression in early stage of diabetic nephropathy. Moreover, BPS may inhibit ICAM-1-dependent infiltration of macrophages in diabetic glomeruli. [Copyright &y& Elsevier]