Rationale, design and baseline characteristics of the effect of canagliflozin in patients with type 2 diabetes and microalbuminuria in the Japanese population: The CANPIONE study.

AIM: To evaluate the effect of canagliflozin, a sodium-glucose co-transporter-2 (SGLT2) inhibitor, on albuminuria and the decline of estimated glomerular filtration rate (eGFR) in participants with type 2 diabetes and microalbuminuria. METHODS: The CANPIONE study is a multicentre, randomized, parallel-group and open-labelled study consisting of a unique 24-week preintervention period, during which the rate of eGFR decline before intervention is estimated, followed by a 52-week intervention and a 4-week washout period. Participants with a geometric mean urinary albumin-to-creatinine ratio (UACR) of 50 and higher and less than 300 mg/g in two consecutive first-morning voids at two different time points, and an eGFR of 45 ml/min/1.73m2 or higher, are randomly assigned to receive canagliflozin 100 mg daily or to continue guideline-recommended treatment, except for SGLT2 inhibitors. The first primary outcome is the change in UACR, and the second primary outcome is the change in eGFR slope. RESULTS: A total of 258 participants were screened and 98 were randomized at 21 sites in Japan from August 2018 to May 2021. The mean baseline age was 61.4 years and 25.8% were female. The mean HbA1c was 7.9%, mean eGFR was 74.1 ml/min/1.73m2 and median UACR was 104.2 mg/g. CONCLUSIONS: The CANPIONE study will determine whether the SGLT2 inhibitor canagliflozin can reduce albuminuria and slow eGFR decline in participants with type 2 diabetes and microalbuminuria.

Visceral adipose tissue-derived serine proteinase inhibitor inhibits apoptosis of endothelial cells as a ligand for the cell-surface GRP78/voltage-dependent anion channel complex.

RATIONALE: Visceral adipose tissue-derived serine proteinase inhibitor (vaspin) is an adipokine identified from visceral adipose tissues of genetically obese rats. OBJECTIVE: The role of vaspin in the diabetic vascular complications remains elusive, and we investigated the effects of vaspin on the vascular function under the diabetic milieu. METHODS AND RESULTS: Adenovirus carrying the full length of the vaspin gene (Vaspin-Ad) ameliorated intimal proliferation of balloon-injured carotid arteries in diabetic Wistar rats. The expression of Ccl2, Pdgfb, and Pdgfrb genes was significantly reduced by the treatment of Vaspin-Ad. In cuff-injured femoral arteries, the intimal proliferation was ameliorated in vaspin transgenic (Vaspin Tg) mice. The application of recombinant vaspin and Vaspin-Ad promoted the proliferation and inhibited the apoptosis of human aortic endothelial cells. Adenovirus expressing vaspin with calmodulin and streptavidin-binding peptides was applied to human aortic endothelial cells, subjected to tandem tag purification and liquid chromatography-tandem mass spectrometry, and we identified GRP78 (78-kDa glucose-regulated protein) as an interacting molecule. The complex formation of vaspin, GRP78, and voltage-dependent anion channel on the plasma membrane was confirmed by the immunoprecipitation studies using aortas of Vaspin Tg mice. The binding assay using (125)I-vaspin in human aortic endothelial cells revealed high-affinity binding (dissociation constant = 0.565×10(-9) m) by the treatment of 5 µM thapsigargin, which recruited GRP78 from the endoplasmic reticulum to plasma membrane by inducing endoplasmic reticulum stress. In human aortic endothelial cells, vaspin induced phosphorylation of Akt and inhibited the kringle 5-induced Ca(2+) influx and subsequent apoptosis. CONCLUSIONS: Vaspin is a novel ligand for the cell-surface GRP78/voltage-dependent anion channel complex in endothelial cells and promotes proliferation, inhibits apoptosis, and protects vascular injuries in diabetes mellitus.

Prednisolone markedly reduced serum IgG4 levels along with the improvement of pituitary mass and anterior pituitary function in a patient with IgG4-related infundibulo-hypophysitis.

In 2011 a 76 year-old man with a medical history of diabetes, hypertension and autoimmune pancreatitis was admitted to our hospital because of anorexia, general malaise and repeated hypoglycemia. When he was 72 years old, he suffered from pancreatitis, and pancreas head tumor was operated. IgG4-related pancreatitis was diagnosed histopathologically. On admission anterior pituitary function test revealed impaired response of ACTH and cortisol to CRH, and no response of GH, TSH and gonadotropin to GHRH, TRH and LHRH, respectively. Baseline PRL level was elevated. Serum IgG and IgG4 levels were markedly elevated. Pituitary MRI showed significant enlargement of pituitary gland and stalk. Chest CT suggested IgG4-related lung disease. IgG4-related infundibulo-hypophysitis was diagnosed based on the above mentioned past history and results of present examinations. Twenty mg of hydrocortisone, followed by 20 mg of prednisolone (PSL) and 25 µg of levothyroxine markedly reduced serum IgG4 levels and ameliorated the symptom, the size of pituitary and stalk, and anterior pituitary function (TSH, GH and gonadotropin), although diabetes insipidus became apparent due to glucocorticoid administration. This is a typical case of IgG4-related hypophysitis in which PSL causes marked improvement of pituitary mass and pituitary function along with the reduction of serum IgG4 levels.

Plasma angiotensin-converting enzyme 2 (ACE2) is a marker for renal outcome of diabetic kidney disease (DKD) (U-CARE study 3).

INTRODUCTION: ACE cleaves angiotensin I (Ang I) to angiotensin II (Ang II) inducing vasoconstriction via Ang II type 1 (AT1) receptor, while ACE2 cleaves Ang II to Ang (1-7) causing vasodilatation by acting on the Mas receptor. In diabetic kidney disease (DKD), it is still unclear whether plasma or urine ACE2 levels predict renal outcomes or not. RESEARCH DESIGN AND METHODS: Among 777 participants with diabetes enrolled in the Urinary biomarker for Continuous And Rapid progression of diabetic nEphropathy study, the 296 patients followed up for 9 years were investigated. Plasma and urinary ACE2 levels were measured by the ELISA. The primary end point was a composite of a decrease of estimated glomerular filtration rate (eGFR) by at least 30% from baseline or initiation of hemodialysis or peritoneal dialysis. The secondary end points were a 30% increase or a 30% decrease in albumin-to-creatinine ratio from baseline to 1 year. RESULTS: The cumulative incidence of the renal composite outcome was significantly higher in group 1 with lowest tertile of plasma ACE2 (p=0.040). Group 2 with middle and highest tertile was associated with better renal outcomes in the crude Cox regression model adjusted by age and sex (HR 0.56, 95% CI 0.31 to 0.99, p=0.047). Plasma ACE2 levels demonstrated a significant association with 30% decrease in ACR (OR 1.46, 95% CI 1.044 to 2.035, p=0.027) after adjusting for age, sex, systolic blood pressure, hemoglobin A1c, and eGFR. CONCLUSIONS: Higher baseline plasma ACE2 levels in DKD were protective for development and progression of albuminuria and associated with fewer renal end points, suggesting plasma ACE2 may be used as a prognosis marker of DKD. TRIAL REGISTRATION NUMBER: UMIN000011525.

RXR antagonism induces G0 /G1 cell cycle arrest and ameliorates obesity by up-regulating the p53-p21(Cip1) pathway in adipocytes.

The peroxisome proliferator activated receptor-γ (PPARγ) agonist, pioglitazone (PIO), exerts anti-diabetic properties associated with increased fat mass, whereas the retinoid X receptor (RXR) antagonist HX531 demonstrates anti-obesity and anti-diabetic effects with reduced body weight and fat pad mass. The cell cycle abnormality in adipocytes has not been well-investigated in obesity or during treatment with modulators of nuclear receptors. We therefore investigated cell size and cell cycle distributions of adipocytes in vivo and examined the expression of cell cycle regulators in cultured human visceral preadipocytes. The cell size distribution and cell cycle analyses of in vivo adipocytes derived from OLETF rats demonstrated that HX531 brought about G0/G1 cell cycle arrest associated with the inhibition of cellular hypertrophy, which resulted in the reduction of fat pad mass. In contrast, PIO promoted proliferation activities associated with the increase in M + late M:G0 + G1 ratio and the appearance of both small and hypertrophied adipocytes. In cultured human visceral preadipocytes HX531 up-regulated cell cycle regulators, p53, p21(Cip1), cyclin D1, Fbxw7 and Skp2, which are known contributors towards G0 /G1 cell cycle arrest. The knockdown of p53 with a shRNA lentivirus reversed the HX531-induced up-regulation of p21(Cip1), which is one of the major p53-effector molecules. We conclude that HX531 exerts anti-obesity and anti-diabetes properties by up-regulating the p53-p21(Cip1) pathway, resulting in G0/G1 cell cycle arrest and the inhibition of cellular hypertrophy of adipocytes.

The serum vaspin levels are reduced in Japanese chronic hemodialysis patients.

BACKGROUND: Visceral adipose tissue-derived serine proteinase inhibitor (vaspin) is an adipokine identified in genetically obese rats that correlates with insulin resistance and obesity in humans. Recently, we found that 7% of the Japanese population with the minor allele sequence (A) of rs77060950 exhibit higher levels of serum vaspin. We therefore evaluated the serum vaspin levels in Japanese chronic hemodialysis patients. METHODS: Healthy Japanese control volunteers (control; n = 95, 49.9 ± 6.91 years) and Japanese patients undergoing hemodialysis therapy (HD; n = 138, 51.4 ± 10.5 years) were enrolled in this study, and serum samples were subjected to the human vaspin RIA system. RESULTS: The measurement of the serum vaspin levels demonstrated that a fraction of control subjects (n = 5) and HD patients (n = 11) exhibited much higher levels (> 10 ng/ml; Vaspin High group), while the rest of the population exhibited lower levels (< 3 ng/ml; Vaspin Low group). By comparing the patients in the Vaspin Low group, the serum vaspin levels were found to be significantly higher in the control subjects (0.87 ± 0.24 ng/ml) than in the HD patients (0.32 ± 0.15 ng/ml) (p < 0.0001). In the stepwise regression analyses, the serum creatinine and triglyceride levels were found to be independently and significantly associated with the vaspin concentrations in all subjects. CONCLUSIONS: The creatinine levels are negatively correlated with the serum vaspin levels and were significantly reduced in the Japanese HD patients in the Vaspin Low group.

Case of subcutaneous insulin resistance syndrome treated with ultra-rapid insulin lispro.

Subcutaneous insulin resistance syndrome is a rare condition that causes difficulty in glycemic control due to severe resistance to subcutaneous insulin injections. We herein present a case of a 40-year-old woman with type 2 diabetes mellitus who had been diagnosed with subcutaneous insulin resistance syndrome since the age of 29 years, and had been persistently treated with continuous subcutaneous insulin infusion using a mixture of insulin lispro and heparin. The patient was switched from insulin lispro plus heparin to ultra-rapid insulin lispro; given that it contains treprostinil and citrate, it is expected to have similar effects as heparin, and shows similar glucose-lowering effects and insulin absorption. Our results suggest that treatment with ultra-rapid insulin lispro is effective for subcutaneous insulin resistance syndrome.

Euglycemic diabetic ketoacidosis in a patient with type 2 diabetes mellitus 3 days after initiating sodium-glucose cotransporter 2 inhibitor while on an extremely low carbohydrate diet: A case report.

This paper presents a case with type 2 diabetes mellitus on a very-low-carbohydrate diet who developed euglycemic diabetic ketoacidosis (EDKA) 3 days after starting sodium-glucose cotransporter 2 inhibitors (SGLT2i). When initiating SGLT2i, healthcare providers should confirm the implementation of a low-carbohydrate diet and provide intensive guidance to prevent EDKA.

Novel Urinary Glycan Biomarkers Predict Cardiovascular Events in Patients With Type 2 Diabetes: A Multicenter Prospective Study With 5-Year Follow Up (U-CARE Study 2).

Background: Although various biomarkers predict cardiovascular event (CVE) in patients with diabetes, the relationship of urinary glycan profile with CVE in patients with diabetes remains unclear. Methods: Among 680 patients with type 2 diabetes, we examined the baseline urinary glycan signals binding to 45 lectins with different specificities. Primary outcome was defined as CVE including cardiovascular disease, stroke, and peripheral arterial disease. Results: During approximately a 5-year follow-up period, 62 patients reached the endpoint. Cox proportional hazards analysis revealed that urinary glycan signals binding to two lectins were significantly associated with the outcome after adjustment for known indicators of CVE and for false discovery rate, as well as increased model fitness. Hazard ratios for these lectins (+1 SD for the glycan index) were UDA (recognizing glycan: mixture of Man5 to Man9): 1.78 (95% CI: 1.24-2.55, P = 0.002) and Calsepa [High-Man (Man2-6)]: 1.56 (1.19-2.04, P = 0.001). Common glycan binding to these lectins was high-mannose type of N-glycans. Moreover, adding glycan index for UDA to a model including known confounders improved the outcome prediction [Difference of Harrel's C-index: 0.028 (95% CI: 0.001-0.055, P = 0.044), net reclassification improvement at 5-year risk increased by 0.368 (0.045-0.692, P = 0.026), and the Akaike information criterion and Bayesian information criterion decreased from 725.7 to 716.5, and 761.8 to 757.2, respectively]. Conclusion: The urinary excretion of high-mannose glycan may be a valuable biomarker for improving prediction of CVE in patients with type 2 diabetes, and provides the rationale to explore the mechanism underlying abnormal N-glycosylation occurring in patients with diabetes at higher risk of CVE. Trial Registration: This study was registered with the University Hospital Medical Information Network on June 26, 2012 (Clinical trial number: UMIN000011525, URL: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000013482).

Thiazolidinediones ameliorate diabetic nephropathy via cell cycle-dependent mechanisms.

Thiazolidinediones are ligands for peroxisome proliferator-activated receptor (PPAR)-gamma, widely used as insulin sensitizer in type 2 diabetic patients and implicated in apoptosis, cell proliferation, and cell cycle regulation. Here, the effect of thiazolidinediones on G1-phase cell cycle arrest, the hallmark in diabetic nephropathy, was investigated. Eight-week-old male Otsuka Long-Evans Tokushima fatty rats were treated with pioglitazone (1 mg x kg body wt(-1) x day(-1)) until 50 weeks of age and compared with insulin treatment. Although similar HbA(1c) levels were observed in both groups, pioglitazone significantly inhibited glomerular hypertrophy and mesangial matrix expansion and reduced urinary albumin excretion compared with the insulin-treated group. In addition, pioglitazone significantly reduced the number of glomerular p27(Kip1)-positive cells. Because prominent expression of PPAR-gamma was observed in podocytes in glomeruli and cultured cells, conditionally immortalized mouse podocyte cells were cultured under 5.5 and 25 mmol/l D-glucose supplemented with pioglitazone. Pioglitazone inhibited cell hypertrophy revealed by [(3)H]thymidine and [(3)H]proline incorporation, and pioglitazone reversed high glucose-induced G1-phase cell cycle arrest, i.e., an increase in G0/G1 phase and decrease in S and G2 phases. Pioglitazone suppressed high glucose-induced phosphorylation of p44/42 mitogen-activated protein kinase and reduced Bcl-2 and p27(Kip1) protein levels. Besides glucose-lowering action, pioglitazone ameliorates diabetic nephropathy via cell cycle-dependent mechanisms.

Urinary PGDS levels are associated with vascular injury in type 2 diabetes patients.

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, beta2-microglobulin (beta2MG), N-acetyl-beta-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 beta2MG, 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.

The Glucose-lowering Efficacy of Sitagliptin in Obese Japanese Patients with Type 2 Diabetes.

Objective Dipeptidyl peptidase-4 (DPP-4) inhibitors are the most frequently prescribed oral hypoglycemic agents in Japan. Although a relationship between the efficacy of DPP-4 inhibitors and the body mass index (BMI) has been reported, this relationship is controversial. We investigated whether the BMI value affects the glucose-lowering efficacy of sitagliptin in obese Japanese patients with type 2 diabetes. Methods One hundred sixty-two outpatients with inadequate glycemic control were divided into four groups based on their baseline BMI values. They were then treated with sitagliptin (a DPP-4 inhibitor) for 3 months and followed-up for 12 months. Results Sitagliptin significantly reduced the hemoglobin A1c level (HbA1c: -0.71±0.55%) after 3 months, and continued to reduce the HbA1c level until 12 months. There was no significant difference in the efficacy of sitagliptin among the four BMI groups. A multiple linear regression analysis indicated that the factors contributing to the change in the HbA1c level were the baseline level of HbA1c and the homeostasis model assessment of ß-cell function (HOMA-ß). In terms of the relationship between the baseline BMI value and the efficacy of sitagliptin treatment, the number of patients who responded to sitagliptin treatment after 3 months was lowest in the group of patients with the highest BMI values. A multiple logistic regression analysis revealed that the baseline HOMA-ß function and HbA1c level and a baseline BMI value of ≥30 kg/m2 significantly contributed to the response to sitagliptin treatment. Conclusion The results indicated that sitagliptin treatment was effective in controlling glucose metabolism disorder in obese Japanese patients with type 2 diabetes. However, the efficacy of sitagliptin treatment might be attenuated in severely obese patients, such as those with a BMI value of ≥30 kg/m2.

Identification of adipocyte adhesion molecule (ACAM), a novel CTX gene family, implicated in adipocyte maturation and development of obesity.

Few cell adhesion molecules have been reported to be expressed in mature adipocytes, and the significance of cell adhesion process in adipocyte biology is also unknown. In the present study, we identified ACAM (adipocyte adhesion molecule), a novel homologue of the CTX (cortical thymocyte marker in Xenopus) gene family. ACAM cDNA was isolated during PCR-based cDNA subtraction, and its mRNA was shown to be up-regulated in WATs (white adipose tissues) of OLETF (Otsuka Long-Evans Tokushima fatty) rats, an animal model for Type II diabetes and obesity. ACAM, 372 amino acids in total, has a signal peptide, V-type (variable) and C2-type (constant) Ig domains, a single transmembrane segment and a cytoplasmic tail. The amino acid sequence in rat is highly homologous to mouse (94%) and human (87%). ACAM mRNA was predominantly expressed in WATs in OLETF rats, and increased with the development of obesity until 30 weeks of age, which is when the peak of body mass is reached. Western blot analysis revealed that ACAM protein, approx. 45 kDa, was associated with plasma membrane fractions of mature adipocytes isolated from mesenteric and subdermal adipose deposits of OLETF rats. Up-regulation of ACAM mRNAs in obesity was also shown in WATs of genetically obese db/db mice, diet-induced obese ICR mice and human obese subjects. In primary cultured mouse and human adipocytes, ACAM mRNA expression was progressively up-regulated during differentiation. Several stably transfected Chinese-hamster ovary K1 cell lines were established, and the quantification of ACAM mRNA and cell aggregation assay revealed that the degree of homophilic aggregation correlated well with ACAM mRNA expression. In summary, ACAM may be the critical adhesion molecule in adipocyte differentiation and development of obesity.

Antiobesity Action of ACAM by Modulating the Dynamics of Cell Adhesion and Actin Polymerization in Adipocytes.

Coxsackie virus and adenovirus receptor-like membrane protein (CLMP) was identified as the tight junction-associated transmembrane protein of epithelial cells with homophilic binding activities. CLMP is also recognized as adipocyte adhesion molecule (ACAM), and it is upregulated in mature adipocytes in rodents and humans with obesity. Here, we present that aP2 promoter-driven ACAM transgenic mice are protected from obesity and diabetes with the prominent reduction of adipose tissue mass and smaller size of adipocytes. ACAM is abundantly expressed on plasma membrane of mature adipocytes and associated with formation of phalloidin-positive polymerized form of cortical actin (F-actin). By electron microscopy, the structure of zonula adherens with an intercellular space of ∼10-20 nm was observed with strict parallelism of the adjoining cell membranes over distances of 1-20 µm, where ACAM and γ-actin are abundantly expressed. The formation of zonula adherens may increase the mechanical strength, inhibit the adipocyte hypertrophy, and improve the insulin sensitivity.

Beneficial impact of Gpnmb and its significance as a biomarker in nonalcoholic steatohepatitis.

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. Gpnmb is classified as a type 1 membrane protein and its soluble form is secreted by ADAM10-mediated cleavage. Gpnmb mRNA was found in the Kupffer cells and white adipose tissues (WATs) and its upregulation in obesity was recently found. Here, we generated aP2 promoter-driven Gpnmb transgenic (Tg) mice and the overexpression of Gpnmb ameliorated the fat accumulation and fibrosis of the liver in diet-induced obesity model. Soluble form of Gpnmb in sera was elevated in Gpnmb Tg mice and Gpnmb concentrated in hepatic macrophages and stellate cells interacted with calnexin, which resulted in the reduction of oxidative stress. In the patients with non-alcoholic steatohepatitis, serum soluble GPNMB concentrations were higher compared with the patients with simple steatosis. The GPNMB is a promising biomarker and therapeutic target for the development and progression of NAFLD in obesity.

Perturbation of autocrine/paracrine loops of burst-forming units of erythroid-derived cells in rHuEPO-hyporesponsive hemodialysis patients.

BACKGROUND: Quantitative or qualitative abnormalities of erythroid progenitors in patients with chronic renal failure (CRF) could be the major factor for recombinant human erythropoietin (rHuEPO) hyporesponsiveness and severe anemia in hemodialysis (HD) patients receiving rHuEPO therapy. METHODS: Purified 1 x 10(4) circulating CD34+ cells isolated from rHuEPO-hyporesponsive HD patients (EPO-H; n = 10), rHuEPO-responsive non-HD patients with CRF (EPO-R; n = 8), nonanemic HD patients without rHuEPO therapy (EPO-W/O; n = 10), and healthy volunteer controls (CON; n = 10) were subjected to a methylcellulose culture system supplemented with rHuEPO, recombinant human interleukin-3 (IL-3), recombinant human stem cell factor (SCF), and recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) for 14 days. RESULTS: The average number of burst-forming units of erythroids (BFU-Es) was significantly less in the EPO-H group compared with the CON and EPO-W/O groups. Furthermore, colony size also was significantly smaller in the EPO-H group. Total RNAs were extracted from approximately 100 colonies/patient and subjected to complementary DNA expression array studies of 268 growth factors, cytokines, chemokines, and their receptors. A characteristic cluster upregulated in the EPO-R and EPO-W/O groups and downregulated in the EPO-H group was identified that contained various cytokines and growth factors, including IL-6, GM-CSF, vascular endothelial growth factor B, IL-9, IL-3, leukemia inhibitory factor, and interferon alpha-2, and such receptors as thrombopoietin receptor, IL-9 receptor, and colony-stimulating factor 1 receptor. CONCLUSION: These data suggest that the cross-talk network or autocrine/paracrine regulatory loop is critically impaired in BFU-E-derived cells in EPO-H patients, and investigation of these cluster genes would facilitate the development of novel therapeutic strategies for such patients.

Urinary fetuin-A is a novel marker for diabetic nephropathy in type 2 diabetes identified by lectin microarray.

We analyzed the urine samples of patients with type 2 diabetes at various stages of diabetic nephropathy by lectin microarray to identify a biomarker to predict the progression of diabetic nephropathy. Japanese patients with type 2 diabetes at various stages of nephropathy were enrolled and we performed lectin microarray analyses (n = 17) and measured urinary excretion of fetuin-A (n = 85). The increased signals of urine samples were observed in Siaα2-6Gal/GalNAc-binding lectins (SNA, SSA, TJA-I) during the progression of diabetic nephropathy. We next isolated sialylated glycoproteins by using SSA-lectin affinity chromatography and identified fetuin-A by liquid chromatography-tandem mass spectrometer. Urinary excretion of fetuin-A significantly increased during the progression of albuminuria (A1, 0.40 ± 0.43; A2, 0.60 ± 0.53; A3 1.57 ± 1.13 ng/gCr; p = 7.29 × 10(-8)) and of GFR stages (G1, 0.39 ± 0.39; G2, 0.49 ± 0.45; G3, 1.25 ± 1.18; G4, 1.34 ± 0.80 ng/gCr; p = 3.89 × 10(-4)). Multivariate logistic regression analysis was employed to assess fetuin-A as a risk for diabetic nephropathy with microalbuminuria or GFR<60 mL/min. Fetuin-A is demonstrated as a risk factor for both microalbuminuria and reduction of GFR in diabetic nephropathy with the odds ratio of 4.721 (1.881-11.844) and 3.739 (1.785-7.841), respectively. Collectively, the glycan profiling analysis is useful method to identify the urine biomarkers and fetuin-A is a candidate to predict the progression of diabetic nephropathy.

Serum vaspin concentrations are closely related to insulin resistance, and rs77060950 at SERPINA12 genetically defines distinct group with higher serum levels in Japanese population.

CONTEXT: Vaspin is an adipokine with insulin-sensitizing effects identified from visceral adipose tissues of genetically obese rats. OBJECTIVE: We investigated genetic and nongenetic factors that define serum concentrations of vaspin. DESIGN, SETTING AND PARTICIPANTS: Vaspin levels were measured with RIA in Japanese subjects with normal fasting plasma glucose (NFG; n = 259) and type 2 diabetes patients (T2D; n = 275). Single nucleotide polymorphisms (SNP) at SERPINA12 (vaspin) gene locus were discovered, and five SNP were genotyped in the subjects with varied body mass index (n = 1138). RESULTS: The level of serum vaspin in 93% of the samples was found to vary from 0.2 to nearly 2 ng/ml in NFG subjects (n = 259) and from 0.2 to nearly 3 ng/ml in T2D patients (n = 275) (Vaspin(Low) group), whereas a significant subpopulation (7%) in both groups displayed much higher levels of 10-40 ng/ml (Vaspin(High) group). In the Vaspin(Low) group, serum vaspin levels in T2D were significantly higher than healthy subjects (0.99 ± 0.04 vs. 0.86 ± 0.02 ng/ml; P < 0.01). Both in T2D and genotyped Japanese population, serum vaspin levels closely correlated with homeostasis model of assessment for insulin resistance rather than anthropometric parameters. By genotyping, rs77060950 tightly linked to serum vaspin levels, i.e. CC (0.6 ± 0.4 ng/ml), CA (18.4 ± 9.6 ng/ml), and AA (30.5 ± 5.1 ng/ml) (P < 2 × 10(-16)). Putative GATA-2 and GATA-3 binding consensus site was found at rs77060950. CONCLUSIONS: Serum vaspin levels were related to insulin resistance, and higher levels of serum vaspin in 7% of the Japanese population are closely linked to minor allele sequence (A) of rs77060950.

Vaspin is an adipokine ameliorating ER stress in obesity as a ligand for cell-surface GRP78/MTJ-1 complex.

It is unknown whether adipokines derived from adipose tissues modulate endoplasmic reticulum (ER) stress induced in obesity. Here, we show that visceral adipose tissue-derived serine protease inhibitor (vaspin) binds to cell-surface 78-kDa glucose-regulated protein (GRP78), which is recruited from ER to plasma membrane under ER stress. Vaspin transgenic mice were protected from diet-induced obesity, glucose intolerance, and hepatic steatosis, while vaspin-deficient mice developed glucose intolerance associated with upregulation of ER stress markers. With tandem affinity tag purification using HepG2 cells, we identified GRP78 as an interacting molecule. The complex formation of vaspin, GRP78, and murine tumor cell DnaJ-like protein 1 (MTJ-1) (DnaJ homolog, subfamily C, member 1) on plasma membrane was confirmed by cell-surface labeling with biotin and immunoprecipitation in liver tissues and H-4-II-E-C3 cells. The addition of recombinant human vaspin in the cultured H-4-II-E-C3 cells also increased the phosphorylation of Akt and AMP-activated protein kinase (AMPK) in a dose-dependent manner, and anti-GRP78 antibodies completely abrogated the vaspin-induced upregulation of pAkt and pAMPK. Vaspin is a novel ligand for cell-surface GRP78/MTJ-1 complex, and its subsequent signals exert beneficial effects on ER stress-induced metabolic dysfunctions.