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1.
BMJ Open Diabetes Res Care ; 12(3)2024 May 30.
Article in English | MEDLINE | ID: mdl-38816205

ABSTRACT

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.


Subject(s)
Angiotensin-Converting Enzyme 2 , Biomarkers , Diabetic Nephropathies , Glomerular Filtration Rate , Peptidyl-Dipeptidase A , Humans , Male , Female , Diabetic Nephropathies/blood , Diabetic Nephropathies/etiology , Diabetic Nephropathies/diagnosis , Angiotensin-Converting Enzyme 2/blood , Biomarkers/blood , Middle Aged , Peptidyl-Dipeptidase A/blood , Aged , Prognosis , Disease Progression , Follow-Up Studies
2.
Proc Natl Acad Sci U S A ; 119(32): e2203121119, 2022 08 09.
Article in English | MEDLINE | ID: mdl-35914124

ABSTRACT

Animals maintain the ability to survive and reproduce by acclimating to environmental temperatures. We showed here that Caenorhabditis elegans exhibited temperature acclimation plasticity, which was regulated by a head-tail-head neural circuitry coupled with gut fat storage. After experiencing cold, C. elegans individuals memorized the experience and were prepared against subsequent cold stimuli. The cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) regulated temperature acclimation in the ASJ thermosensory neurons and RMG head interneurons, where it modulated ASJ thermosensitivity in response to past cultivation temperature. The PVQ tail interneurons mediated the communication between ASJ and RMG via glutamatergic signaling. Temperature acclimation occurred via gut fat storage regulation by the triglyceride lipase ATGL-1, which was activated by a neuropeptide, FLP-7, downstream of CREB. Thus, a head-tail-head neural circuit coordinated with gut fat influenced experience-dependent temperature acclimation.


Subject(s)
Acclimatization , Adipose Tissue , Caenorhabditis elegans , Cold Temperature , Digestive System , Head , Neural Pathways , Tail , Acclimatization/physiology , Adipose Tissue/metabolism , Animals , Caenorhabditis elegans/anatomy & histology , Caenorhabditis elegans/physiology , Caenorhabditis elegans Proteins/metabolism , Cyclic AMP Response Element-Binding Protein/metabolism , Digestive System/metabolism , Glutamic Acid/metabolism , Head/innervation , Interneurons/metabolism , Lipase/metabolism , Neuropeptides/metabolism , Tail/innervation , Thermosensing
3.
Biosensors (Basel) ; 12(2)2022 Feb 09.
Article in English | MEDLINE | ID: mdl-35200364

ABSTRACT

Extracellular vesicles (EVs) have gained considerable attention as vital circulating biomarkers since their structure and composition resemble the originating cells. The investigation of EVs' biochemical and biophysical properties is of great importance to map them to their parental cells and to better understand their functionalities. In this study, a novel frequency-dependent impedance measurement system has been developed to characterize EVs based on their unique dielectric properties. The system is composed of an insulator-based dielectrophoretic (iDEP) device to entrap and immobilize a cluster of vesicles followed by utilizing electrical impedance spectroscopy (EIS) to measure their impedance at a wide frequency spectrum, aiming to analyze both their membrane and cytosolic charge-dependent contents. The EIS was initially utilized to detect nano-size vesicles with different biochemical compositions, including liposomes synthesized with different lipid compositions, as well as EVs and lipoproteins with similar biophysical properties but dissimilar biochemical properties. Moreover, EVs derived from the same parental cells but treated with different culture conditions were characterized to investigate the correlation of impedance changes with biochemical properties and functionality in terms of pro-inflammatory responses. The system also showed the ability to discriminate between EVs derived from different cellular origins as well as among size-sorted EVs harbored from the same cellular origin. This proof-of-concept approach is the first step towards utilizing EIS as a label-free, non-invasive, and rapid sensor for detection and characterization of pathogenic EVs and other nanovesicles in the future.


Subject(s)
Dielectric Spectroscopy , Extracellular Vesicles , Electric Impedance
4.
J Clin Lipidol ; 16(2): 237-245, 2022.
Article in English | MEDLINE | ID: mdl-35101360

ABSTRACT

BACKGROUND: Glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1 (GPIHBP1) plays a crucial role in lipolytic processing. Previous studies have shown that GPIHBP1 mutations cause severe hypertriglyceridemia and that serum GPIHBP1 levels are marginally higher in patients with coronary heart disease; however, the role of GPIHBP1 in type 2 diabetes mellitus (T2DM) remains unknown. OBJECTIVE: We investigated the association between circulating GPIHBP1 levels and the prevalence of microvascular complications in T2DM. METHODS: A total of 237 subjects with T2DM and 235 non-diabetic control subjects were enrolled in this study. Their serum GPIHBP1 levels were evaluated using ELISA assays. RESULTS: Circulating GPIHBP1 levels were higher in patients with T2DM (952.7 pg/mL [761.3-1234.6], p < 0.0001) than in non-diabetic subjects (700.6 [570.8-829.6]), but did not differ in T2DM patients with or without hypertriglyceridemia. Serum GPIHBP1 levels were significantly higher in patients with T2DM with diabetic retinopathy (DR), diabetic nephropathy (DN), and microvascular complications than in those without these complications. Multivariable logistic regression and receiver operating characteristic (ROC) curve analyses revealed that the presence of microvascular complications, but not macrovascular complications, was independently associated with serum GPIHBP1 levels, which could predict the presence of diabetic microvascular complications. CONCLUSIONS: Elevated GPIHBP1 levels are associated with microvascular complications in T2DM and may help to predict their progression.


Subject(s)
Diabetes Mellitus, Type 2 , Diabetic Nephropathies , Diabetic Retinopathy , Hypertriglyceridemia , Receptors, Lipoprotein , Cross-Sectional Studies , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/epidemiology , Diabetic Nephropathies/complications , Female , Humans , Hypertriglyceridemia/complications , Male , Receptors, Lipoprotein/genetics
5.
Front Cardiovasc Med ; 8: 668059, 2021.
Article in English | MEDLINE | ID: mdl-34109226

ABSTRACT

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).

6.
Endocrinology ; 162(4)2021 04 01.
Article in English | MEDLINE | ID: mdl-33567453

ABSTRACT

Argonaute 2 (Ago2) is the main component of the RNA-induced silencing complex. We recently showed that liver-specific Ago2-deficiency in mice (L-Ago2 knockout [KO] mice) enhances mitochondrial oxidation and alleviates obesity-associated pathophysiology. However, the precise mechanisms behind the role of hepatic Ago2 in regulating the mitochondrial oxidation associated with glucose metabolism are still unclear. Here, we show that hepatic Ago2 regulates the function of peroxisome proliferator-activated receptor α (PPARα) for oxidative metabolism. In both genetically and diet-induced severe obese conditions, L-Ago2 KO mice developed obesity and hepatic steatosis but exhibited improved glucose metabolism accompanied by lowered expression levels of pathologic microRNAs (miRNAs), including miR-802, miR-103/107, and miR-152, and enhanced expression of PPARα and its target genes regulating oxidative metabolism in the liver. We then investigated the role of hepatic Ago2 in the outcomes of vertical sleeve gastrectomy (VSG) in which PPARα plays a crucial role in a drastic transcription reprogram associated with improved glycemia post VSG. Whereas VSG reduced body weight and improved fatty liver in wild-type mice, these effects were not observed in hepatic Ago2-deficient mice. Conversely, glucose metabolism was improved in a hepatic Ago2-dependent manner post VSG. Treating Ago2-deficient primary hepatocytes with WY-14643, a PPARα agonist, showed that Ago2-deficiency enhances sensitivity to WY-14643 and increases expression of PPARα target genes and mitochondrial oxidation. Our findings suggest that hepatic Ago2 function is intrinsically associated with PPARα that links Ago2-mediated RNA silencing with mitochondrial functions for oxidation and obesity-associated pathophysiology.


Subject(s)
Argonaute Proteins/deficiency , Liver/metabolism , Obesity/metabolism , Obesity/surgery , PPAR alpha/metabolism , Animals , Argonaute Proteins/genetics , Bariatric Surgery , Glucose/metabolism , Glucose Tolerance Test , Glycemic Control , Hepatocytes/metabolism , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Obesity/drug therapy , Obesity/genetics , Oxidative Stress , PPAR alpha/genetics , Pyrimidines/administration & dosage
7.
J Vis Exp ; (140)2018 10 23.
Article in English | MEDLINE | ID: mdl-30417869

ABSTRACT

Hepatocytes are parenchymal cells of the liver and engage multiple metabolic functions, including synthesis and secretion of proteins essential for systemic energy homeostasis. Primary hepatocytes isolated from the murine liver constitute a valuable biological tool to understand the functional properties or alterations occurring in the liver. Herein we describe a method for the isolation and culture of primary mouse hepatocytes by performing a two-step collagenase perfusion technique and discuss their utilization for investigating protein metabolism. The liver of an adult mouse is sequentially perfused with ethylene glycol-bis tetraacetic acid (EGTA) and collagenase, followed by the isolation of hepatocytes with the density gradient buffer. These isolated hepatocytes are viable on culture plates and maintain the majority of endowed characteristics of hepatocytes. These hepatocytes can be used for assessments of protein metabolism including nascent protein synthesis with non-radioactive reagents. We show that the isolated hepatocytes are readily controlled and comprise a higher quality and volume stability of protein synthesis linked to energy metabolism by utilizing the chemo-selective ligation reaction with a Tetramethylrhodamine (TAMRA) protein detection method and western blotting analyses. Therefore, this method is valuable for investigating hepatic nascent protein synthesis linked to energy homeostasis. The following protocol outlines the materials and methods for the isolation of high-quality primary mouse hepatocytes and detection of nascent protein synthesis.


Subject(s)
Alanine/analogs & derivatives , Hepatocytes/metabolism , Proteins/metabolism , Alanine/metabolism , Animals , Cells, Cultured , Hepatocytes/cytology , Mice
8.
Nat Commun ; 9(1): 3658, 2018 09 10.
Article in English | MEDLINE | ID: mdl-30201950

ABSTRACT

RNA silencing inhibits mRNA translation. While mRNA translation accounts for the majority of cellular energy expenditure, it is unclear if RNA silencing regulates energy homeostasis. Here, we report that hepatic Argonaute 2 (Ago2)-mediated RNA silencing regulates both intrinsic energy production and consumption and disturbs energy metabolism in the pathogenesis of obesity. Ago2 regulates expression of specific miRNAs including miR-802, miR-103/107, and miR-148a/152, causing metabolic disruption, while simultaneously suppressing the expression of genes regulating glucose and lipid metabolism, including Hnf1ß, Cav1, and Ampka1. Liver-specific Ago2-deletion enhances mitochondrial oxidation and ATP consumption associated with mRNA translation, which results in AMPK activation, and improves obesity-associated pathophysiology. Notably, hepatic Ago2-deficiency improves glucose metabolism in conditions of insulin receptor antagonist treatment, high-fat diet challenge, and hepatic AMPKα1-deletion. The regulation of energy metabolism by Ago2 provides a novel paradigm in which RNA silencing plays an integral role in determining basal metabolic activity in obesity-associated sequelae.


Subject(s)
AMP-Activated Protein Kinases/metabolism , Argonaute Proteins/metabolism , Obesity/enzymology , RNA Interference , Animals , Diet, High-Fat , Eukaryotic Initiation Factors/metabolism , Gene Deletion , Genotype , Glucose/metabolism , Glucose Tolerance Test , Glycolysis , Humans , Hyperglycemia/metabolism , Liver/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , MicroRNAs/metabolism , Mitochondria/metabolism , Oxygen/metabolism , Pyruvic Acid/metabolism
9.
Diabetes ; 65(5): 1255-67, 2016 05.
Article in English | MEDLINE | ID: mdl-26956488

ABSTRACT

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.


Subject(s)
Actin Cytoskeleton/metabolism , Adherens Junctions/metabolism , Adipocytes, White/metabolism , Adiposity , Coxsackie and Adenovirus Receptor-Like Membrane Protein/metabolism , Obesity/prevention & control , Up-Regulation , 3T3-L1 Cells , Actin Cytoskeleton/pathology , Actin Cytoskeleton/ultrastructure , Adherens Junctions/pathology , Adherens Junctions/ultrastructure , Adipocytes, White/cytology , Adipocytes, White/pathology , Adipocytes, White/ultrastructure , Animals , Cell Adhesion , Cell Size , Coxsackie and Adenovirus Receptor-Like Membrane Protein/genetics , Diabetes Mellitus/etiology , Diabetes Mellitus/metabolism , Diabetes Mellitus/pathology , Diabetes Mellitus/prevention & control , Diet, High-Fat/adverse effects , Dietary Sucrose/adverse effects , Female , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Microscopy, Immunoelectron , Obesity/etiology , Obesity/metabolism , Obesity/pathology , Recombinant Fusion Proteins/metabolism
10.
Sci Rep ; 6: 21721, 2016 Feb 17.
Article in English | MEDLINE | ID: mdl-26883167

ABSTRACT

Although obesity is undoubtedly major risk for non-alcoholic steatohepatitis (NASH), the presence of lean NASH patients with normal body mass index has been recognized. Here, we report that the insufficiency of phosphatidylethanolamine N-methyltransferase (PEMT) is a risk for the lean NASH. The Pemt-/- mice fed high fat-high sucrose (HFHS) diet were protected from diet-induced obesity and diabetes, while they demonstrated prominent steatohepatitis and developed multiple liver tumors. Pemt exerted inhibitory effects on p53-driven transcription by forming the complex with clathrin heavy chain and p53, and Pemt-/- mice fed HFHS diet demonstrated prominent apoptosis of hepatocytes. Furthermore, hypermethylation and suppressed mRNA expression of F-box protein 31 and hepatocyte nuclear factor 4α resulted in the prominent activation of cyclin D1. PEMT mRNA expression in liver tissues of NASH patients was significantly lower than those with simple steatosis and we postulated the distinct clinical entity of lean NASH with insufficiency of PEMT activities.


Subject(s)
Hepatocytes/cytology , Non-alcoholic Fatty Liver Disease/pathology , Phosphatidylethanolamine N-Methyltransferase/genetics , Phosphatidylethanolamine N-Methyltransferase/metabolism , Animals , Apoptosis , Cells, Cultured , Clathrin Heavy Chains/metabolism , Diet, High-Fat , Disease Models, Animal , Down-Regulation , Gene Knockdown Techniques , Genetic Predisposition to Disease , Humans , Mice , Non-alcoholic Fatty Liver Disease/enzymology , Non-alcoholic Fatty Liver Disease/genetics , Obesity/prevention & control , Tumor Suppressor Protein p53/metabolism
11.
Sci Rep ; 5: 16920, 2015 Nov 19.
Article in English | MEDLINE | ID: mdl-26581806

ABSTRACT

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.


Subject(s)
Eye Proteins/metabolism , Membrane Glycoproteins/metabolism , Non-alcoholic Fatty Liver Disease/metabolism , 3T3-L1 Cells , Adipocytes/metabolism , Adipocytes/pathology , Adipose Tissue, White/metabolism , Animals , Biomarkers/metabolism , Calnexin/metabolism , Eye Proteins/blood , Eye Proteins/genetics , Female , Gene Expression Regulation , Hepatic Stellate Cells/metabolism , Liver/metabolism , Liver/pathology , Liver Cirrhosis/complications , Liver Cirrhosis/pathology , Logistic Models , Macrophages/metabolism , Male , Membrane Glycoproteins/blood , Membrane Glycoproteins/genetics , Mice , Mice, Inbred C57BL , Mice, Transgenic , Multivariate Analysis , Obesity/complications , Obesity/pathology , Protein Binding , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats, Inbred OLETF , Risk Factors
12.
Acta Med Okayama ; 69(2): 123-7, 2015.
Article in English | MEDLINE | ID: mdl-25899635

ABSTRACT

An 81-year-old Japanese male with primary Sjögren syndrome (pSS) developed a low-grade fever and productive cough which were refractory to antibiotic therapy. Based on the high level of eosinophils observed in his bronchial alveolar lavage, he was diagnosed with chronic eosinophilic pneumonia (CEP) and successfully treated by oral prednisolone. Interstitial lung diseases associated with pSS (pSS-ILDs) usually present as nonspecific interstitial pneumonia or usual interstitial pneumonia; therefore, the present case is extremely unique in that the patient's condition was complicated with CEP. A diagnosis of advanced gallbladder cancer was made in the patient's clinical course, suggesting the advisability of a whole-body workup in cases of pSS, especially in elderly patients.


Subject(s)
Pulmonary Eosinophilia/diagnosis , Pulmonary Eosinophilia/etiology , Sjogren's Syndrome/complications , Administration, Oral , Adrenal Cortex Hormones/administration & dosage , Adrenal Cortex Hormones/therapeutic use , Aged, 80 and over , Chronic Disease , Humans , Male , Prednisolone/administration & dosage , Prednisolone/therapeutic use , Pulmonary Eosinophilia/drug therapy , Treatment Outcome
13.
Metabolism ; 64(6): 677-88, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25749183

ABSTRACT

OBJECTIVE: In obesity and type 2 diabetes, the impairment of mitochondrial function in white adipose tissue (WAT) is linked to a reduction in whole body insulin sensitivity. Timm44 is upregulated in the kidneys of streptozotocin-induced diabetic mice. In the inner mitochondrial membrane, Timm44 anchors mitochondrial heat-shock protein 70 (mtHsp70) to the translocase of inner mitochondrial membrane 23 (TIM23) complex and facilitates the import of mitochondria-targeted preproteins into the mitochondrial matrix dependent on the inner membrane potential and ATP hydrolysis on ATPase domain of mtHsp70. METHODS: We generated the aP2-promoter driven Timm44 transgenic (Tg) mouse model and investigated whether Timm44 Tg mice fed high-fat/high-sucrose (HFHS) chow are protected from type 2 diabetes and obesity. RESULTS: The body weight of aP2-promoter driven Timm44 Tg mice was lower than that of wild type mice, and insulin sensitivity was greater in Timm44 Tg mice than in wild type mice. Although WAT weight was not altered in Timm44 Tg mice fed HFHS chow, adipocyte size was reduced, and mitochondrial fusion associated with decreased expression of fission genes, such as Dnm1l and Fis1, was observed. In addition, when fed standard (STD) chow, the expressions of the fusion genes Opa1, Mfn1 and Mfn2, and Mfn1 were significantly increased in Timm44 Tg mice compared to wild type mice, and fused mitochondria were also observed in Timm44 Tg mice fed STD chow. CONCLUSIONS: The Timm44 gene may be a new target for the treatment of type 2 diabetes.


Subject(s)
Carrier Proteins/metabolism , Diabetes Mellitus, Type 2/enzymology , Membrane Proteins/metabolism , Mitochondrial Membranes/enzymology , Mitochondrial Proteins/metabolism , Adenosine Triphosphatases/metabolism , Adenosine Triphosphate/metabolism , Adipocytes , Animals , Carrier Proteins/genetics , Cell Differentiation , Diabetes Mellitus, Experimental/genetics , Diabetes Mellitus, Experimental/prevention & control , Diabetes Mellitus, Type 2/genetics , Fibroblasts/metabolism , HSP70 Heat-Shock Proteins/genetics , HSP70 Heat-Shock Proteins/metabolism , Humans , Insulin Resistance , Membrane Potential, Mitochondrial , Membrane Proteins/genetics , Mice , Mice, Inbred C57BL , Mice, Transgenic , Mitochondrial Membrane Transport Proteins , Mitochondrial Precursor Protein Import Complex Proteins , Mitochondrial Proteins/genetics
14.
Metabolism ; 64(4): 489-97, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25726255

ABSTRACT

PURPOSE: The unique circulating microRNAs (miRNAs) observed in patients with type 2 diabetes (T2D) are candidates as new biomarkers and therapeutic targets. In order to identify circulating miRNAs relevant to the disease process in case of type 2 diabetes, we performed the Illumina sequencing of miRNAs derived from the serum, liver and epididymal white adipose tissue (WAT) of diet-induced obese male C57BL/6J mice. BASIC PROCEDURES: We selected four miRNAs, miR-101, miR-335, miR-375, and miR-802, which are increased in the sera and tissues of obese mice, and measured the serum levels of miRNAs in T2D and subjects with normal glucose tolerance (NGT). MAIN FINDINGS: The serum concentrations of miRNAs, log(10)miR-101, log(10)miR-375, and log(10)miR-802, were significantly increased in the T2D patients compared with NGT subjects (1.41±2.01 v.s. -0.57±1.05 (P=1.36×10(-5)), 0.20±0.58 v.s. 0.038±1.00 (P=3.06×10(-6)), and 2.45±1.27 v.s. 0.97±0.98 (P=0.014), respectively). The log(10)miR-335 values did not demonstrate any significant differences between the T2D and NGT groups (-1.08±1.35 v.s. -0.38±1.21 (P=0.25)). According to the stepwise regression analysis, the HbA1c was an independent predictor of miR-101. Regarding the serum miR-802 levels, eGFR, HbA1c and HDL-C values were identified as significant determinants. PRINCIPAL CONCLUSIONS: The present findings demonstrated that the circulating miR-101, miR-375 and miR-802 levels are significantly increased in T2D patients versus NGT subjects and they may become the new biomarkers for type 2 diabetes.


Subject(s)
Biomarkers/blood , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/diagnosis , MicroRNAs/blood , Adult , Aged , Animals , Blood Glucose/metabolism , Cross-Sectional Studies , Female , Glucose Tolerance Test , Humans , Male , Mice , Mice, Inbred C57BL , Middle Aged
15.
PLoS One ; 9(3): e92647, 2014.
Article in English | MEDLINE | ID: mdl-24667182

ABSTRACT

Phosphatidylethanolamine N-methyltransferase (Pemt) catalyzes the methylation of phosphatidylethanolamine (PE) to phosphatidylcholine (PC) mainly in the liver. Under an obese state, the upregulation of Pemt induces endoplasmic reticulum (ER) stress by increasing the PC/PE ratio in the liver. We targeted the Pemt gene in mice to explore the therapeutic impact of Pemt on the progression of diabetic nephropathy and diabetes, which was induced by the injection of streptozotocin (STZ). Although the blood glucose levels were similar in STZ-induced diabetic Pemt+/+ and Pemt-/-mice, the glomerular hypertrophy and albuminuria in Pemt-/- mice were significantly reduced. Pemt deficiency reduced the intraglomerular F4/80-positive macrophages, hydroethidine fluorescence, tubulointerstitial fibrosis and tubular atrophy. The expression of glucose-regulated protein-78 (GRP78) was enriched in the renal tubular cells in STZ-induced diabetic mice, and this was ameliorated by Pemt deficiency. In mProx24 renal proximal tubular cells, the treatment with ER-stress inducers, tunicamycin and thapsigargin, increased the expression of GRP78, which was reduced by transfection of a shRNA lentivirus for Pemt (shRNA-Pemt). The number of apoptotic cells in the renal tubules was significantly reduced in Pemt-/- diabetic mice, and shRNA-Pemt upregulated the phosphorylation of Akt and decreased the cleavage of caspase 3 and 7 in mProx24 cells. Taken together, these findings indicate that the inhibition of Pemt activity ameliorates the ER stress associated with diabetic nephropathy in a model of type 1 diabetes and corrects the functions of the three major pathways downstream of ER stress, i.e. oxidative stress, inflammation and apoptosis.


Subject(s)
Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Type 1/metabolism , Diabetic Nephropathies/metabolism , Endoplasmic Reticulum Stress , Kidney Tubules, Proximal/metabolism , Phosphatidylethanolamine N-Methyltransferase/metabolism , Animals , Apoptosis/genetics , Diabetes Mellitus, Experimental/genetics , Diabetes Mellitus, Experimental/pathology , Diabetes Mellitus, Type 1/genetics , Diabetes Mellitus, Type 1/pathology , Diabetic Nephropathies/genetics , Diabetic Nephropathies/pathology , Endoplasmic Reticulum Chaperone BiP , Gene Expression Regulation/genetics , Heat-Shock Proteins/biosynthesis , Heat-Shock Proteins/genetics , Inflammation/genetics , Inflammation/metabolism , Inflammation/pathology , Kidney Tubules, Proximal/pathology , Mice , Mice, Knockout , Oxidative Stress/genetics , Phosphatidylethanolamine N-Methyltransferase/genetics , Proto-Oncogene Proteins c-akt/genetics , Proto-Oncogene Proteins c-akt/metabolism
16.
Int J Nephrol Renovasc Dis ; 6: 233-40, 2013.
Article in English | MEDLINE | ID: mdl-24174882

ABSTRACT

PURPOSE: Urinary angiotensinogen has been reported as a marker for the activation of intrarenal renin-angiotensin system (RAS) in various kidney diseases. To investigate the importance of urinary angiotensinogen in diabetic nephropathy, we compared the urinary levels of angiotensinogen, albumin, and α1-microglobulin. MATERIALS AND METHODS: Japanese patients with type 2 diabetes at various stages of nephropathy (n=85) were enrolled, and we measured albumin/creatinine ratio (ACR) and urinary excretion of angiotensinogen and α1-microglobulin. We also compared the clinical data of the patients treated with or without angiotensin II receptor blockers or angiotensin-converting enzyme inhibitors (RAS inhibitors [+], n=51; RAS inhibitors [-], n=34). RESULTS: Urinary angiotensinogen levels positively correlated with ACR (r=0.367, P=3.84×10(-4)) and urinary α1-microglobulin (r=0.734, P=1.32 × 10(-15)), while they negatively correlated with estimated glomerular filtration ratio (eGFR) (r=-0.350, P=1.02 × 10(-3)) and high-density lipoprotein cholesterol (r=-0.216, P=0.049). Multiple regression analysis was carried out to predict urinary angiotensinogen levels by employing eGFR, ACR, and urinary α1-microglobulin as independent variables; only urinary α1-microglobulin entered the regression equation at a significant level. Although ACR was higher in the RAS inhibitors (+) group, urinary α1-microglobulin and angiotensinogen did not show significant increase in the RAS inhibitors (+) group. CONCLUSION: Urinary angiotensinogen is well correlated with urinary α1-microglobulin and reflected the tubular injuries which may be associated with the intrarenal RAS activation in patients with type 2 diabetes.

17.
PLoS One ; 8(10): e77118, 2013.
Article in English | MEDLINE | ID: mdl-24143207

ABSTRACT

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.


Subject(s)
Diabetes Mellitus, Type 2/complications , Diabetic Nephropathies/urine , Microarray Analysis/methods , Plant Lectins/metabolism , alpha-2-HS-Glycoprotein/urine , Alpha-Globulins/metabolism , Alpha-Globulins/urine , Biomarkers/urine , Diabetic Nephropathies/blood , Diabetic Nephropathies/complications , Female , Humans , Male , Middle Aged , N-Acetylneuraminic Acid/metabolism , Risk , alpha-2-HS-Glycoprotein/metabolism
18.
Circ Res ; 112(5): 771-80, 2013 Mar 01.
Article in English | MEDLINE | ID: mdl-23307819

ABSTRACT

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.


Subject(s)
Adipokines/metabolism , Apoptosis/physiology , Endothelium, Vascular/pathology , Heat-Shock Proteins/metabolism , Serpins/metabolism , Voltage-Dependent Anion Channels/metabolism , Adenoviridae/genetics , Adipokines/genetics , Animals , Cell Membrane/metabolism , Cell Proliferation , Cells, Cultured , Diabetes Mellitus, Experimental/chemically induced , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/pathology , Disease Models, Animal , Endoplasmic Reticulum Chaperone BiP , Humans , Ligands , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Rats , Rats, Wistar , Serpins/genetics , Streptozocin/adverse effects
19.
BMC Nephrol ; 14: 23, 2013 Jan 22.
Article in English | MEDLINE | ID: mdl-23339460

ABSTRACT

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 p27(Kip1) and p21(Cip1). 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 Log(10)Gal-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). Log(10)Gal-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). Log(10)Gal-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.


Subject(s)
Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/epidemiology , Galectins/blood , Renal Insufficiency, Chronic/blood , Renal Insufficiency, Chronic/epidemiology , Biomarkers/blood , Comorbidity , Diabetes Mellitus, Type 2/diagnosis , Female , Humans , Incidence , Japan/epidemiology , Male , Middle Aged , Renal Insufficiency, Chronic/diagnosis , Reproducibility of Results , Risk Assessment , Sensitivity and Specificity
20.
Diab Vasc Dis Res ; 10(1): 93-6, 2013 Jan.
Article in English | MEDLINE | ID: mdl-22561230

ABSTRACT

Telmisartan partially activates the peroxisome proliferator-activated receptor γ (PPARγ), which may ameliorate the accumulation of visceral adipose tissues and sensitise insulin action. Nineteen patients with essential hypertension and metabolic syndrome were randomly assigned to receive 40 mg of telmisartan (TELMI group) once daily or 80 mg of valsartan (VAL group) once daily for 24 weeks. The visceral fat area (VFA) measured by computed tomography (CT) was significantly reduced from 150.4±15.5 to 127.7±16.7 cm(2) in the TELMI group (p=0.049). Although VFA was also reduced in the VAL group from 169.8±14.8 to 155.3±14.8 cm(2), the change was not significant (p=0.173). There were no significant changes in body weight, body mass index (BMI), waist circumference, subdermal fat area (SFA), fasting plasma glucose, and homeostasis model assessment of insulin resistance (HOMA-IR) in comparison to the baseline and follow-up data in both groups. In conclusion, telmisartan may have a benefit in the reduction of visceral adipose tissues in comparison to valsartan.


Subject(s)
Angiotensin II Type 1 Receptor Blockers/therapeutic use , Benzimidazoles/therapeutic use , Benzoates/therapeutic use , Hypertension/drug therapy , Intra-Abdominal Fat/drug effects , Metabolic Syndrome/complications , PPAR gamma/agonists , Aged , Blood Glucose/drug effects , Blood Pressure/drug effects , Body Mass Index , Body Weight/drug effects , Female , Humans , Hypertension/complications , Insulin Resistance , Intra-Abdominal Fat/diagnostic imaging , Male , Middle Aged , Subcutaneous Fat/drug effects , Telmisartan , Tetrazoles/therapeutic use , Tomography, X-Ray Computed , Treatment Outcome , Valine/analogs & derivatives , Valine/therapeutic use , Valsartan , Waist Circumference/drug effects
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