bluuebunny/crossref_metadata_2025 huggingface dataset:
Lower Ectopic Fat Accumulation in Obese Women May Help Explain Sex Differences in the Magnitude of Insulin Resistance
Authors: GILLEN JENNA B. , RYAN BENJAMIN J. , GIOSCIA-RYAN RACHEL A. , LUDZKI ALISON , CHENEVERT THOMAS L. , HOROWITZ JEFFREY F.
Published: June 2018

Accumulating evidence suggests obese women maintain higher insulin sensitivity than obese men, but factors underlying this sex difference in insulin resistance remain unclear. We recently developed a semi-automated method for quantifying visceral and hepatic fat using advanced chemical shift-encoded magnetic resonance imaging (MRI). Using this method, we explored whether sex differences in ectopic fat accumulation may contribute to differences in insulin resistance. Twenty-one obese women (32 ± 6 year, 34.5 ± 3.1 kg/m2, 43.1 ± 5.5 kg fat mass (FM)) and a well-matched cohort of fifteen obese men (29 ± 6 year, 34.5 ± 3.3 kg/m2, 42.0 ± 7.8 kg FM) underwent an MRI scan during which 5mm axial slices were acquired from the abdominal region. Using 3D Slicer software, visceral fat area was quantified on three axial slices from the L2-L3 vertebrae region and averaged. Hepatic fat was quantified as the average percentage fat from three axial slices of the liver. On a separate day, subjects underwent a hyperinsulinemic-euglycemic clamp to quantify insulin sensitivity. Compared with men, women had lower hepatic (4.2 ± 5.5 vs. 13.1 ± 9.7%, p<0.001) and visceral (114 ± 49 vs. 201 ± 87 cm2, p<0.001) fat, which corresponded with higher insulin sensitivity (Glucose infusion rate during clamp [GIR]: 514 ± 330 vs. 263 ± 134 umol/kgFFM/SSI/min, p<0.05). To further examine the relationship between ectopic lipid accumulation and insulin resistance, we stratified subjects into tertiles by hepatic fat content (n=12 per group). Interestingly, nearly all subjects in the lowest tertile for hepatic fat (1.1 ± 0.6%) were women, and when compared to the highest hepatic fat tertile (17.7 ± 8.2%), they also had lower visceral fat (101 ± 61 vs. 214 ± 83 cm2, p<0.001) and importantly, were also more insulin sensitive (GIR: 626 ± 350 vs. 279 ± 238 umol/kgFFM/SSI/min, p<0.05). Our findings suggest lower ectopic fat deposition may help explain the lower degree of insulin resistance in obese women compared with men.

Disclosure

J.B. Gillen: None. B.J. Ryan: None. R.A. Gioscia-Ryan: None. A. Ludzki: None. T.L. Chenevert: None. J.F. Horowitz: None.
Endobarrier® Gastrointestinal Liner in Obese Subjects with Type 2 Diabetes—Short- and Midterm Effects on Glucose Metabolism
Authors: TRIPOLT NORBERT J. , ABERER FELIX , URL JASMIN , PFERSCHY PETER N. , HÖGENAUER CHRISTOPH , SCHREIBER FLORIAN , EHERER ANDREAS , SVEHLIKOVA EVA , SOURIJ CAREN , OBERMAYER ANNA M. , STADLBAUER VANESSA , SOURIJ HARALD
Published: June 2018

Background: A 60cm endoscopically implantable, duodeno-jejunal bypass liner (Endobarrier®) has been introduced as a therapeutic option for obese subjects with type 2 diabetes (T2DM). The aim of the study was to explore short and mid-term metabolic effects in the clamp setting.

Materials and Methods: This open, single-center trial investigated 10 obese, T2DM subjects with suboptimal glycemic control (HbA1c >48mmol/mol). Prior to the implantation of the gastrointestinal liner (baseline), 4 weeks and 9 months (explantation) after, all subjects underwent Dual-energy X-ray absorptiometry (DXA) measurement, assessment of beta cell function and insulin sensitivity by a Botnia clamp procedure and a mixed-meal tolerance test.

Results: We investigated 10 patients with a mean age of 48±9 years and mean diabetes duration of 7±6 years. Detailed results and changes over the time are given in Table. No device has been removed prematurely.

Conclusion: Treating obese T2DM subjects by an endoluminally implanted Endobarrier® leads to moderate weight reduction with large inter-individual variation. Significant improvements in insulin sensitivity occurred already 4 weeks after the Endobarrier® implantation, which were maintained until the explantation of the device, accompanied by reductions in blood pressure.Baseline (mean±SD)4 Weeks (mean±SD)9 Monhts (mean±SD)p-value (Group comparison baseline vs. 4 weeks)p-value (Group comparison baseline vs. 9 months)Body weight (kg)121.2 ± 18.5116.3 ± 18.2115.7± 22.5<0.0010.016Fat-Mass (kg)58.1 ± 12.055.0 ± 12.553.3 ± 16.10.0010.014HbA1c (mmol/mol)61 ± 1056 ± 955 ± 120.0160.139Blood pressure systolic (mmHg)143 ± 16129 ± 24125 ± 210.0590.007Blood pressure diastolic (mmHg)94 ± 1085 ± 1579 ± 160.1070.021Glucose infusion rate (mg/kg/min)0.50 ± 1.020.86 ± 0.990.81 ± 1.28<0.0010.034C-peptide AUC (ng/mL/min)8.10 ± 3.017.27 ± 3.765.81 ± 2.090.4400.046

Disclosure

N.J. Tripolt: None. F. Aberer: None. J. Url: None. P.N. Pferschy: None. C. Högenauer: None. F. Schreiber: None. A. Eherer: None. E. Svehlikova: None. C. Sourij: None. A.M. Obermayer: None. V. Stadlbauer: None. H. Sourij: Speaker's Bureau; Self; Boehringer Ingelheim GmbH, Novo Nordisk A/S, Amgen Inc., Sanofi, MSD K.K.. Research Support; Self; AstraZeneca, Boehringer Ingelheim GmbH, MSD K.K., GI Dynamics Inc..
Genetic Risk for Type 1 Diabetes Profoundly Influences the Core Gut Microbiome in Children
Authors: RUSSELL JORDAN , ROESCH LUIZ , ATKINSON MARK A. , SCHATZ DESMOND , TRIPLETT ERIC W. , LUDVIGSSON JOHNNY
Published: June 2018

All of the gut microbiome associations with type 1 diabetes autoimmunity to date have been discovered in cohorts where all subjects are at high genetic risk for the disease. The design of such cohorts precludes an assessment of the influence HLA high risk alleles on gut microbiome composition. This question is addressed here by using stool samples from the general population All Babies in Southeast Sweden (ABIS) cohort where most children are at no genetic risk for type 1 diabetes. A proportion of ABIS children do possess high risk alleles including DR3/DQ2, DR4/DQ8, and DRB1. DNA from stool samples, collected at one year of age from 441 ABIS children (169 at high genetic risk), stored at -80°C, was extracted and 16S rRNA amplified, sequenced, and analyzed. The core microbiome for each category was computed by including only those reads from taxa found in at least 70% of all subjects within that group. The core microbiomes of the two groups were readily separated by PCoA (Fig. 1) and were significantly different (p=0.001). Each core microbiome comprised about 65% of the reads collected. Bifidobacterium was significantly higher in the no-risk group while Veillonella was higher in the risk group. Thus, HLA risk alleles appear to influence the core gut microbiome and posit a novel mechanism whereby the microbiome may influence the pathogenesis of type 1 diabetes.

Disclosure

J. Russell: None. L. Roesch: None. M.A. Atkinson: Other Relationship; Self; Patent Issued. D. Schatz: None. E.W. Triplett: None. J. Ludvigsson: None.
The Visceral Adiposity Index Predicts Cardiovascular Events Both in Cardiovascular Disease Patients With and in Those Without Diabetes
Authors: SAELY CHRISTOPH H. , VONBANK ALEXANDER , HEINZLE CHRISTINE , ZANOLIN DANIELA , LARCHER BARBARA , MADER ARTHUR , LEIHERER ANDREAS , MUENDLEIN AXEL , DREXEL HEINZ
Published: June 2018

The visceral adiposity index (VAI) is a validated tool for the evaluation of visceral adiposity, using waist circumference, serum triglycerides, age and gender to diagnose this metabolic abnormality. It has recently been associated with cardiovascular risk in primary care patients. No data are available on the association of the VAI with mortality in patients with cardiovascular disease (CVD).

We therefore prospectively recorded the incidence of cardiovascular events over a mean follow-up period of 7.9± 3.1 years in a large cohort of 1858 consecutive patients with established cardiovascular disease (1599 patients with angiographically proven coronary artery disease and 259 patients with sonographically proven peripheral artery disease). The VAI was calculated according to the Amato formula; type 2 diabetes (T2DM) was defined according to the ADA definition.

At baseline, the VAI was significantly higher in CVD patients with T2DM than in those who did not have diabetes (347±331 vs. 228±200; p<0.001). Prospectively, 585 vascular events occurred; the event rate was significantly higher in patients with T2DM than in those who did not have diabetes (46.8% vs. 31.3%; p<0.001). After multivariate adjustment, the VAI significantly predicted cardiovascular events in CVD patients with T2DM (standardized adjusted hazard ratio (HR) 1.24 [1.09-1.42]; p=0.007) as well as in

those who did not have T2DM (HR 1.18 [1.06-1.31]; p=0.014).

We conclude that the VAI predicts cardiovascular events both in CVD patients with and in those without diabetes.

Disclosure

C.H. Saely: None. A. Vonbank: None. C. Heinzle: None. D. Zanolin: None. B. Larcher: None. A. Mader: None. A. Leiherer: None. A. Muendlein: None. H. Drexel: None.
Effect of Restricted Caloric Intake and Bariatric Surgery on PCSK9 Concentrations in Plasma
Authors: GHANIM HUSAM , ABUAYSHEH SANAA , MONTE SCOTT , DANDONA PARESH
Published: June 2018

PCSK9 is a major modulator of LDLc through internalization and endosomal degradation of LDL receptor. It has been shown that PCSK9 plasma levels predict CVD risk. Bariatric surgery is known to reduce both LDLc and CVD. However, its exact effect on circulating PCSK9 levels has not been fully investigated. We have now investigated the effect of strict caloric restriction and Roux-en-Y bariatric surgery (RYGB) in 15 morbidly obese patients on plasma PCSK-9 levels. Subjects were instructed to follow a regimen of 4 liquid shakes (up to 16g carbohydrate, 0g fat, and 33g of protein, total daily intake was 550-785 calories) during the 2-weeks strict caloric restriction period prior to surgery and the usual dietary regime after surgery. Blood samples were obtained at 2 weeks before, at the time of surgery and 6 months after RYGB. There was a significant weight loss of 7.8±2.4 Kg during the 2 weeks prior to surgery and of additional 26.6±5.3 Kg 6 months after surgery. At completion of strict caloric restriction, subjects had a significant reductions in glucose, insulin and HOMA-IR (7.1±1.1 to 4.5± 1.0) which continued following surgery (HOMA-IR (4.5±1.0 to 2.1± 0.3). LDL(c) fell significantly by 11±7% (from 120±6 to 109±7mg/dl) following the strict caloric restriction and by 15±8% (from 109±7 to 95±6mg/dl) following surgery. There was a reduction of 38±11% (from 227±25 to 139±15 ng/ml) in plasma PCSK9 concentration in the 2 weeks of caloric restriction. Thereafter, PCSK9 levels increased to 166±22ng/ml over the next 6 months. Our data show that there is an impressive and concurrent fall in PCSK9, LDL(c) concentrations and insulin resistance following strict caloric restriction. The marked weight loss over 6 months has only a marginal effect on PCSK9 concentrations while metabolic improvements persisted. This reduction in PCSK9 may contribute to the known benefit in cardiovascular outcomes following bariatric surgery.

Disclosure

H. Ghanim: None. S. Abuaysheh: None. S. Monte: Stock/Shareholder; Self; Mobile Pharmacy Solutions (Community Pharmacy). Employee; Self; Synergy Bariatrics, a Department of ECMC. P. Dandona: Advisory Panel; Self; AstraZeneca. Consultant; Self; AstraZeneca. Research Support; Self; AstraZeneca.
The Positive Effect of the Combination of GLP-1 Analogues and SGLT2 Inhibitors on Obese Patients with Noninsulin-Treated DM2
Authors: MATSOUKIS IOANNIS L. , GANOTOPOULOU ASIMINA , TRIANTAFILLOPOULOU CHRYSOULA , KANELLOPOULOU KONSTANTINA , ATHANASOPOULOU THEODORA , SIANNI ALEXANDRA
Published: June 2018

Introduction: GLP-1 analogues and SGLT2 inhibitors have complementary mechanisms of action. The aim of the study is to evaluate the results and tolerance of the combination of these medicines.

Purpose: To investigate the effect of the combination of GLP-1 analogues and SGLT2 inhibitors on obese patients with non-insulin-treated DM2.

Method: The study included 150 patients, out of which 110 (73.3%) were women with a mean age of 58 ± 5 years and 40 (26.6%) were men with a mean age of 62 ± 6 years, The mean BMI was 36± 4 and all patients received oral medication for the treatment of DM2 (metformin ± DPP-4 ± sulfonylureas ± glitazone). The study duration was one year and HbA1c, fasting glucose, body weight, and body mass index (BMI) were measured at 3, 6, 9 and 12 months. All patients changed their medication to metformin + GLP-1 + SGLT2.

Results: A decrease in HbA1c levels were observed at 3 months (mean HbA1c 10 ± 1.8), at 6 months (mean HbA1c 9 ± 1.3), at 9 months (mean HbA1c 8.7 ± 1) and at 12 months (mean HbA1c 7 ± 0.8) (p = 0.030). Fasting glucose also showed a gradual reduction in the follow-up tests, namely 185 ± 29mg / dl, 168 ± 22mg / dl, 156 ± 20mg / dl and 145 ± 18mg / dl at 3, 6, 9 and 12 months respectively (p = 0.0045). Same results were also observed when body weight was measured at 3,6,9 and 12 months (125 ± 18 kg, 1± 14 kg, 100 ± 8 kg and 98 ± 8 kg respectively) (p = 0,042). Changes in BMI were also occured with a mean BMI of 42 ± 7.2 at 3 months, 40 ± 6.8 at 6 months, 38 ± 6.4 at 9 months and 35 ± 5 at 12 months of follow-up period (p = 0.043).

Conclusion: The combination of metformin + GLP-1 + SGLT2 has many benefits in the metabolic profile of obese patients with DM2 and could be considered as a choice treatment.

Disclosure

I.L. Matsoukis: None. A. Ganotopoulou: None. C. Triantafillopoulou: None. K. Kanellopoulou: None. T. Athanasopoulou: None. A. Sianni: None.
Injury Factors Alter miRNAs Profiles of Exosomes Derived from Islets and Circulation
Authors: FU QI , JIANG HEMIN , YANG TAO
Published: June 2018

Islets damage is a major abnormality underling diabetes, thus timely monitoring islets destruction is critically needed. Recent studies discovered the biological functions of exosomes and suggested the value of exosomes in disease diagnosis and prognosis. This study aimed to investigate the impact of injury factors on the miRNA profiles of islet exosomes and determine whether circulating exosomal miRNAs would be suitable as biomarkers of islets cell damage. Islets were isolated from ICR mice and induced injury in vitro by mixed cytokines (TNFα, IL-1β and IFNγ) and streptozotocin (STZ) and exosomes were derived from the cultural supernatant. Using miRNA microarray analysis, we found 22 and 11 differentially expressed miRNAs in islet exosomes of STZ and cytokines treatment, respectively. 6 differentially expressed exosaml miRNAs were found both in STZ and cytokines treated group, and miR-375-3p and miR-129-5p were validated by quantitative RT-PCR. Serum exosomes were isolated from ICR mice of islets damage in vivo induced by STZ injection and subjects with various glucose metabolism states and diabetic duration. Quantitative RT-PCR demonstrated exosomal miR-375-3p dramatically increased in serum of STZ treated mouse prior to the turbulence of blood glucose and serum insulin. In human serum exosomes, miR-375-3p was elevated in newly new-onset diabetes patients. Overall, our results suggest that injury factors cytokines and STZ affected the miRNA profiles of exosomes derived from islets and exosomal miR-375-3p showed promising potential as a biomarker of islets damage. Further studies were necessary to purify islet-specific exosomes from circulation for improving the accuracy.

Disclosure

Q. Fu: None. H. Jiang: None. T. Yang: None.
Tissue Plasminogen Activator (tPA) Expression Is Increased by Islet Amyloid Formation In Vitro
Authors: ESSER NATHALIE , HOGAN MEGHAN F. , TEMPLIN ANDREW T. , ZIEMANN MARK , EL-OSTA ASSAM , ZRAIKA SAKENEH , HULL REBECCA L. , KAHN STEVEN E.
Published: June 2018

Islet amyloid deposition is a pathologic hallmark of type 2 diabetes (T2D) resulting in β-cell loss. tPA, an activator of fibrinolysis, attenuates brain amyloid deposition associated with Alzheimer’s disease. Based on RNAseq analysis to identify genes upregulated by islet amyloid, we found tPA to be specifically increased in islets with amyloid deposition (FDR=6.23 E-40). We therefore determined whether tPA expression is explicitly regulated by islet amyloid formation and thus could impact islet pathology in T2D. Using a transgenic mouse expressing human islet amyloid polypeptide (hIAPP) in β cells, a model of islet amyloid formation, and mice expressing non-amyloidogenic mouse IAPP (mIAPP) as control, we measured tPA mRNA expression in islets during amyloid formation. Isolated islets were cultured for up to 7 days in 11.1 or 16.7 mM glucose, the latter to induce amyloid deposition in hIAPP islets. Under amyloidogenic conditions, tPA gene expression increased 2-fold after 2 days of culture and was further elevated at 7 days in hIAPP compared to mIAPP islets (7.6±1.4 vs. 1.2±0.1, n=4, p<0.001). This increase at 7 days was not observed in hIAPP islets cultured under non-amyloidogenic conditions (1.1±0.5 vs. 7.6±1.4 in 11.1 vs. 16.7 mM glucose, respectively, n=4, p<0.001). When cultured in 16.7 mM glucose with an amyloid inhibitor (200 μM Congo Red [CR]), tPA gene expression was abrogated in hIAPP transgenic islets (1.5±0.14 vs. 9.5±0.33 with or without CR, respectively, n=4, p<0.001), implying tPA gene expression is regulated downstream of amyloid formation. Immunoblot confirmed the presence of tPA protein in islets but not in a β-cell line, and islet immunohistochemistry showed it did not co-localize with insulin, suggesting it is likely that tPA is not produced in β cells.

In summary, we identified the fibrinolytic activator tPA to be upregulated with amyloid formation in islets. Thus, modulating tPA expression could reduce the deleterious impact of islet amyloid on β-cell mass in T2D.

Disclosure

N. Esser: None. M.F. Hogan: None. A.T. Templin: None. M. Ziemann: None. A. El-Osta: None. S. Zraika: None. R.L. Hull: Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Eli Lilly and Company. S.E. Kahn: Advisory Panel; Self; Boehringer Ingelheim GmbH, Elcelyx Therapeutics, Inc., Eli Lilly and Company, Intarcia Therapeutics, Inc., Janssen Research & Development, Merck & Co., Inc., Novo Nordisk A/S.
The Effect of nAChR Signaling on Terminal-Unfolded Protein Response under Endoplasmic Reticulum Stress in INS1 Cells
Authors: ISHIBASHI TATSUYA , MORITA SHUHEI , DOI ASAKO , IWAKURA HIROSHI , ARIYASU HIROYUKI , NISHI MASAHIRO , FURUTA HIROTO , AKAMIZU TAKASHI
Published: June 2018

Background: Pancreatic β-cells are specialized for the production of insulin and susceptible to endoplasmic reticulum (ER) stress. Irremediable ER stress is coupled with terminal-unfolded protein response (T-UPR) through activating IRE1α, which leads to β-cell dysfunction and apoptosis. Previous reports show the effects of nAChR signaling against ER stress-induced neurotoxicity. However, it is still unknown if and how nAChR signaling affects T-UPR in β-cells. The aim of the study is to determine if and how nAChR signaling reduces T-UPR by regulating IRE1α activity in β-cells.

Methods: We investigate the role of nAChR signaling on T-UPR signaling under ER stress or specific IRE1αactivation using rat insulinoma cell line, INS-1 cells. Cells were treated with Nicotine; an agonist of nAChR, α-Bungarotoxin(α-BTX); an antagonist of nAChR α7 subunit, and Tunicamycin(Tm) and Thapsigargin(Tg); ER stress inducers. Expression levels of spliced XBP1 and TXNIP/Insulin1 (Proinsulin), as T-UPR markers, were analyzed by real time PCR and/or Western blotting.

Results: We first confirmed the expression levels of nAChR α7 subunits in INS1 cells. ER stress inducers (Tm or Tg) increased XBP1 splicing, and Nicotine (>10 μM) reduced it. Nicotine reversed ER stress-induced increase of TXNIP and decrease of Insulin1 (proinsulin) expression in both mRNA and protein levels. Further, Nicotine reversed increase of TXNIP and decrease of Insulin1 mRNA expression levels induced by IRE1α overexpression in Dox-inducible wild type IRE1α-overexpressing INS1 cells. Those effects of Nicotine were canceled by α-BTX.

Conclusion: Our results suggest that nAChR signaling could prevent T-UPR induced by ER stress in INS1 cells.

Disclosure

T. Ishibashi: None. S. Morita: None. A. Doi: None. H. Iwakura: None. H. Ariyasu: None. M. Nishi: None. H. Furuta: None. T. Akamizu: None.
Functional Characterization of Wolfram Syndrome 1 Protein in ß-Cell Function and Viability
Authors: ABREU DAMIEN , LAVAGNINO ZENO , BROWN CRIS M. , PISTON DAVID W. , URANO FUMIHIKO
Published: June 2018

Endoplasmic reticulum (ER) homeostasis is crucial for proper β-cell function as evidenced by rare monogenic diabetic disorders, such as Wolfram syndrome, arising from genetic defects in key ER molecules. Wolfram syndrome stems from mutation of the ER transmembrane protein, Wolfram Syndrome 1 (WFS1), resulting in a recessive, progressive neurodegenerative disorder that first manifests as juvenile-onset diabetes mellitus (DM). While many WFS1 variants are associated with DM, the role of WFS1 in β-cell viability and function remains unclear. Our central hypothesis is that WFS1 regulates β-cell viability through downregulation of ER stress-responsive pro-apoptotic factors and β-cell function through modulation of key ER Ca2+ transporters. To test this hypothesis, we generated inducible β-cell models of WFS1 knockdown and overexpression using rat insulinoma cell lines to monitor β-cell function and β-cell death. We employed chemical and physiologic stimuli to model ER stress and monitored its downstream effects by real-time PCR, immunoblot and intracellular calcium mobilization. Our data indicate that β-cells depleted of WFS1 exhibit impaired insulin secretion and reduced insulin content. Additionally, knockdown of WFS1 is associated with decreased ER Ca2+, increased cytosolic Ca2+ and increased β-cell death. Conversely, increasing WFS1 expression in vitro increases insulin production and confers protection against ER stress-mediated β-cell death. Our data suggest that WFS1 may preserve β-cell viability by reducing the expression of pro-apoptotic factors CHOP and TRIB3. Future studies seek to clarify the mechanisms by which WFS1 protects β-cells against metabolic stressors and promotes insulin production. These studies will expand our understanding of the broader mechanisms by which ER dysfunction triggers β-cell pathology in more common forms of diabetes, and provide potential novel targets for intervention that center on preserving ER homeostasis.

Disclosure

D. Abreu: None. Z. Lavagnino: None. C.M. Brown: None. D.W. Piston: None. F. Urano: Research Support; Self; Eli Lilly and Company. Stock/Shareholder; Self; CytRx.
Discovery and Fine-Mapping of Type 2 Diabetes Susceptibility Loci in Diverse Populations Using More than a Million Individuals
Authors: MAHAJAN ANUBHA , KITAJIMA HIDETOSHI , SIM XUELING , NG MAGGIE , ZHANG WEIHUA , BELOW JENNIFER E. , PAYNE ANTHONY J. , GAULTON KYLE , MORRIS ANDREW
Published: June 2018

To discover type 2 diabetes (T2D) loci and enhance fine-mapping resolution, we conducted the largest meta-analysis of genome-wide association studies of the disease to date by aggregating 171,262 cases and 1,075,072 controls from diverse populations (45% non-European ancestry). We identified 250 loci at genome-wide significance (p<5x10-8); 59 mapped outside regions previously implicated in T2D. Across these loci, conditional analyses revealed a total of 475 distinct signals of association (locus-wide significance, p<10-5). We observed strong evidence of heterogeneity in allelic effects on T2D (pHET<1.4x10-4, Bonferroni correction) correlated with ancestry at 17% of signals, including LEP (rs35589574, pHET=4.8x10-25, East Asian specific) and multiple associations at/near KCNQ1 and TCF7L2 (representing ethnic-specific/-differentiated effects). T2D-associated variants showed significant enrichment (odds-ratio range 1.90-6.63; p<0.05) in coding exons, pancreatic islet enhancers and promoters, adipose enhancers, and binding sites for transcription factors, including NKX2.2 and FOXA2. Increased sample size, population diversity, and annotation-informed fine-mapping substantially improved localisation of potential causal variants compared with previous efforts, and highlighted 76 signals with a single variant accounting for >80% of the posterior probability of association (PPA); of these 35 signals had PPA of >99%. Clustering of signal-specific annotation enrichment highlighted distinct clades of T2D associations driven by different underlying molecular processes. These analyses represent the most comprehensive view of the genetic contribution to T2D to date and, through integration with expression quantitative trait loci in disease-relevant tissues, point to previously unreported effector genes (such as SKOR1, CLUAP1, and PEPD) and mediating molecular mechanisms at several loci.

Disclosure

H. Kitajima: None. X. Sim: None. M. Ng: None. W. Zhang: None. J.E. Below: None. A.J. Payne: None. K. Gaulton: None. A. Morris: None.
Mig6 Is Required for Pancreas Development in Zebrafish
Authors: EL KIMBERLEY , FUEGER PATRICK T. , ANDERSON RYAN M.
Published: June 2018

Strategies to promote β cell neogenesis could be used to restore functional β cell mass in both type 1 and type 2 diabetes. Here we examine the role of mitogen-inducible gene 6 (mig6, a.k.a. erffi1) in the regulation of functional β cell mass. mig6 is evolutionarily conserved and encodes a protein that inhibits the epidermal growth factor receptor (EGFR) in a classic feedback mechanism, suggesting a potential role in cellular growth and development. Based on functional studies in mouse and human, we hypothesized that mig6 is required in pancreatic ducts for pancreatogenesis and β cell function. We used morpholino knockdown in zebrafish to define the role of mig6 in both exocrine pancreas and islet development. We established that mig6 knockdown (mig6MO) embryos have a disrupted pancreas morphogenesis, particularly, a truncated exocrine pancreas and fewer intra-pancreatic duct cells. Additionally, mig6MO-injected animals had fewer β cells than controls. Together, our data lead us to hypothesize that mig6 may facilitate the expansion of the pancreas progenitor pool by blocking EGFR activation. We further investigated the role of mig6 in islet regeneration. Neogenic β cells may arise from two sources in the developing zebrafish, which can be distinguished by the retention of a fluorescent mark made at the one-cell stage. β cells derived via transdifferentiation from other postmitotic endocrine cells remain labeled whereas those derived from duct-associated progenitors lose their label via proliferation. We found that although the number of regenerated β cells was reduced overall in mig6MO-injected embryos, most new β cells were not labeled, suggesting that a significant progenitor pool remains in the knockdown embryos. Together, our data demonstrate that mig6 is essential for pancreas development and that it might be exploited as a switch between progenitor differentiation and endocrine transdifferentiation to increase β cell mass in diabetic patients.

Disclosure

K. El: None. P.T. Fueger: None. R.M. Anderson: None.
Functional Maturation of Pancreatic ß Cells during Development
Authors: STANESCU DIANA E. , LI CHANGHONG , YANG JUXIANG , YAU DAPHNE , STANLEY CHARLES A.
Published: June 2018

Insulin is crucial for intrauterine growth of the fetus and insulin secretion must be maintained irrespective of maternal plasma glucose variations. This is achieved through a maturational islet adaptation which persists during the first postnatal days and can lead to prolonged neonatal hypoglycemia. We aimed to investigate the characteristics of insulin release in the fetal and perinatal period. We performed perifusions of human fetal islet samples at 18-20 weeks gestation and of rat islets between embryonic day (e)22 and postnatal day (P)14. Human fetal islets at 18-20 weeks gestation released insulin in response to lower glucose concentrations (1-2 mM), compared to adult islets (3-5 mM). Similarly, rat islets at e22-P1 also had a lower glucose threshold for insulin release (3mM), compared to P14 islets (5 mM). BCH, a leucine analog that activates glutamate dehydrogenase, also stimulated insulin release at a lower concentration in e22-P1 rat islets (1mM), compared to P14 islets (3mM). This suggests that the mechanism of the islet adaptation in intrauterine life lies distal to glycolysis and fuel oxidation, potentially in differences in membrane depolarization or repolarization. In addition, human fetal islets released insulin in response to lactate, while late embryonic rat islets did not, suggesting insulin release in response to other nutrient stimuli may also be part of this maturational islet adaptation. Ongoing experiments are further exploring substrate-induced insulin release in immature islets, in parallel with the characterization of β cell transcriptomic maturation at the single cell level in both human and rat. Understanding the functional maturation of β cells during the fetal and neonatal period, coupled with the insight into the molecular mechanisms responsible for this maturation, can lead of the development of molecular markers of a dysregulated β cell function that is may persist beyond early neonatal period.

Disclosure

D.E. Stanescu: Employee; Spouse/Partner; GlaxoSmithKline plc.. C. Li: None. J. Yang: None. D. Yau: None. C.A. Stanley: None.
Effects of a Healthy Postweaning Diet on Endocrine Defects Caused by In Utero High-Fat Diet Exposure in Mouse and Japanese Macaque
Authors: ELSAKR JOSEPH , KIEVIT PAUL , POWERS ALVIN C. , GANNON MAUREEN A. , BOTTINO RITA , TAKAHASHI DIANA L.
Published: June 2018

The Developmental Origins of Health and Disease Hypothesis states that the in utero environment influences postnatal health and plays a role in disease etiology. In humans, exposure to maternal obesity in utero increases diabetes susceptibility in the offspring. In the U.S., it is estimated that about half of pregnancies occur in overweight or obese mothers. Thus, the consequences of maternal obesity will be manifested in future generations. Animal models have demonstrated that exposure to maternal high-fat-diet (HFD) feeding or obesity results in morphological alterations in the pancreatic islets, as well as impaired expression of islet transcription factors in the offspring. However, effects of in utero diet exposure often vary significantly between animal models. In a non-human primate (NHP) model of maternal overnutrition, we have demonstrated that fetuses exposed to HFD have reduced islet hormone transcript levels and increased β:α cell ratio due to decreased α-cell mass. This increase in β:α cell ratio persists post-weaning out to three years only when offspring are maintained on a HFD. However, maternal or post-weaning diet does not affect endocrine cell proliferation or β-cell mass in this model. Preliminary data in a mouse model of maternal overnutrition suggests that mice exposed to HFD are glucose intolerant shortly after weaning onto control diet, but have no differences in β-cell mass. When mice are aged to 12-weeks-old, the difference in glucose tolerance is no longer apparent, and body weight is not different between HFD-exposed and control mice. Data from the NHP model suggests that maternal HFD exposure results in subtle alterations in islet structure that persist only when offspring are maintained on HFD. In the mouse, impairments in glucose tolerance shortly after weaning are resolved when offspring are maintained on a control, lower-fat diet until 12 weeks of age.

Disclosure

J. Elsakr: None. P. Kievit: Research Support; Self; Novo Nordisk A/S, Janssen Research & Development. A.C. Powers: None. M.A. Gannon: None. R. Bottino: None. D.L. Takahashi: None.
Youth with Avoidable DKA—Going from Bad to Worse without NICH
Authors: SACHDEJ RAJKARAN , KOSKELA NATALIE C. , WAGNER DAVID V. , BARRY SAMANTHA A. , JENISCH CELESTE , HARRIS MICHAEL A.
Published: June 2018

Objective: Novel Interventions in Children’s Healthcare (NICH) was developed for youth with T1D who experience avoidable DKAs. Previous findings suggest that NICH participation is associated with fewer PICU visits, hospital admissions, and DKA events, but interpretation is limited due to possibility of regression to the mean. This study examines whether youth experience fewer acute events during the wait period following referral to NICH.

Methods: Retrospective chart reviews were conducted for youth with T1D (n=63) who participated in NICH services. Youth mean age was 14.8 years; 57% were female; and 86% were Caucasian. Mean days prior to referral, on wait list, and during NICH were 365, 129, and 353, respectively. Results were normalized across time points to reflect rate of likely event occurrence during 1 year period.

Results: Youth were significantly more likely to experience a PICU stay (p=.03) while waiting for NICH compared to baseline and were significantly less likely to experience a DKA (p=.02) or PICU stay (p=.01) during NICH involvement compared to the wait period.

Conclusions: Instead of spontaneously improving after baseline (i.e., regression to the mean), youth referred to NICH experience an increase in acute complications while waiting for services, then improvement during NICH involvement. Perhaps referring providers are identifying factors that suggest further deterioration of health without more intensive services.

Disclosure

R. Sachdej: None. N.C. Koskela: None. D.V. Wagner: None. S.A. Barry: None. C. Jenisch: None. M.A. Harris: Consultant; Self; Eli Lilly and Company.
The Increment of Noradrenergic Fibers Correlates with the Density of Dedifferentiated ß Cells in Humans
Authors: CINTI FRANCESCA , SEVERI ILENIA , SULEIMAN MARA , MARSELLI LORELLA , MARCHETTI PIERO , CINTI SAVERIO , ACCILI DOMENICO
Published: June 2018

β cells dedifferentiation has been recently introduced as the main mechanism responsible for the functional “disappearance” of β cells from the islands of diabetic subjects. Starting from results obtained from a mouse model of type 2 (T2) diabetes (in whose a significant increase in density of noradrenergic fibers was detected compared to nondiabetic mice), we asked if the result could be replicated in humans and if it could be related to the process of dedifferentiation. Human pancreas of 8 healthy donors and 9 with T2 diabetes were analyzed by immunohistochemistry (M / F 4/4 vs. 5/4 NS; BMI (kg / m2) 24.8 ± 2.8 vs. 25.6 ± 4.1; NS). The dedifferentiation score was calculated as % of cells synaptophysin positive but negative for the four major pancreatic hormones. Tyrosine hydroxylase (TH) was used as a marker for the evaluation of noradrenergic fiber expression. The islands of diabetic subjects were about 3 times more innervated than controls (0.42 ± 0.51 vs. 1.66 ± 2.2 n.fibersTH +/island; p = 0.02); the increase of these fibers correlated positively with the dedifferentiation score (p <0.001; r = 0.69).

In conclusion, our data show an increase in the number of sympathetic nerve fibers potentially able to transmit inhibitory signals on insulin secretion in the islands of diabetic subjects. The important correlation with the dedifferentiation score suggests a significant role of noradrenergic fibers in the pathogenesis of the dedifferentiation process, introducing new strategies for the preservation of cellular mass/secretion and, therefore, for the prevention and treatment of T2 diabetes.

Disclosure

F. Cinti: None. I. Severi: None. M. Suleiman: None. L. Marselli: None. P. Marchetti: None. S. Cinti: None. D. Accili: None.
Tobacco Smoking Results in Reduced Pancreatic Islet Mass in Humans
Authors: CHETBOUN MIKAËL , KERR-CONTE JULIE A. , GMYR VALERY , THUILLIER DOROTHÉE , EZZOUAOUI RIMED , HUBERT THOMAS , RAVERDY VIOLETA , BONGIOVANNI ANTONINO , DAOUDI MEHDI , VANTYGHEM MARIE-CHRISTINE , PATTOU FRANCOIS
Published: June 2018

Epidemiological studies identify tobacco as an independent risk factor for T2D, however, the mechanisms involved remains unclear. Clinical studies incriminate an increase of insulin resistance but a direct effect on pancreatic islet mass is suggested by some animal studies. The aim of this study was to document the association between tobacco smoking and pancreatic islet mass in humans.Total islet mass (TIM) was measured in 484 pancreata from organ donors processed with standardized islet isolation technique for clinical islet transplantation. Number and size of islets were assessed following enzymatic digestion. Functional islet mass was estimated in a cohort of 845 obese subjects, by measuring c-peptide to glucose ratio at 30 min (CP/G-30) following an oral glucose load. Pancreatic islet mass proxies were correlated with donor smoking status and tobacco consumption (generalized linear model).TIM was negatively associated with smoking status in organ donors (estimate:-0.131;P=0.017), independently of other known predictors: BMI (-0.019; P=0.001), age (-0.009; P=0.0001). CP/G-30 was also reduced in vivo in subjects with smoking history. TIM (Figure A-B) and CP/G-30 (Figure C-D) were negatively correlated with the level of tobacco consumption.Pancreatic islet mass was reduced in subjects with smoking history, with a dose-response relationship with tobacco consumption. Our results support the direct implication of smoking in T2D.

Disclosure

M. Chetboun: None. J.A. Kerr-Conte: None. V. Gmyr: None. D. Thuillier: None. R. Ezzouaoui: None. T. Hubert: None. V. Raverdy: None. A. Bongiovanni: None. M. Daoudi: None. M. Vantyghem: Board Member; Self; Aegerion Pharmaceuticals. Other Relationship; Self; Elsevier. Research Support; Self; Ipsen Biopharmaceuticals, Inc., Novartis Pharmaceuticals Corporation. F. Pattou: None.
Novel Use of Agent 11C-PHNO for Pet CT Imaging of Pancreatic Beta-Cell Mass
Authors: RANGEL ELIZABETH SANCHEZ , BINI JASON , NABULSI NABEEL B. , HUANG YIYUN , HEROLD KEVAN C. , SHERWIN ROBERT , CARSON RICHARD E. , CLINE GARY
Published: June 2018

There is growing interest in developing a method to measure pancreatic beta-cell mass (BCM) so as to: 1) monitor progression of beta cell changes in type 1 and type 2 diabetes; 2) identify therapies to preserve, restore or regenerate beta cells; and 3) monitor viability of islets after transplantation therapy. Given that beta cells and neurons have functional similarities, we tested the hypothesis that receptors, transporters, or proteins essential for signal detection and propagation, may be common to both cell types. Hence, we assessed if Positron Emission Tomography (PET) imaging ligands originally developed for neuroimaging may provide a means for imaging BCM as well. Previous studies have shown higher uptake of 11C-(+)-4-propyl-9-hydroxynaphthoxazine (PHNO), a dopamine D2/D3 agonist radioligand (D3-preferring), in the pancreatic tissue of healthy controls vs. T1DM in humans. In this study, we sought to determine whether 11C-PHNO, would be useful for measuring BCM. Eleven subjects (6 with T1DM, 4 males and 2 females, age 30.8 ± 11.4 years, BMI 24.4 ± 2.0, and 5 matched healthy controls, 3 males and 2 females, age 32.2 ± 11.4 years, BMI 26.4 ± 2.1) underwent abdominal PET/CT imaging using 11C-PHNO. Regions-of-interest (ROIs) were applied to the pancreas, liver, spleen, and kidney and time-activity curves (TACs) were produced and converted to standard uptake value (SUV) units. The distribution of activity between the head, body, and tail of the pancreas was also assessed. We observed that there was a 41% reduction in 11C-PHNO SUV in T1DM patients as compared to the healthy control group (p = 0.026). Moreover, there was a positive correlation between plasma c-peptide concentrations and 11C-PHNO SUV in the pancreas (r = 0.78), although this relationship did not reach statistical significance (p = 0.1), most likely due to the small sample size. These data suggest that dopamine D3 expression in pancreatic tissue might serve as a useful biomarker for assessing beta cell mass in diabetic humans.

Disclosure

E. Sanchez Rangel: None. J. Bini: None. N.B. Nabulsi: None. Y. Huang: None. K.C. Herold: None. R. Sherwin: Other Relationship; Self; QuintilesIMS, MannKind Corporation. Research Support; Self; Regeneron Pharmaceuticals, Inc.. Other Relationship; Self; ICON plc. R.E. Carson: Research Support; Self; Pfizer Inc., Bristol-Myers Squibb Company, Eli Lilly and Company, UCB, Inc., Siemens. G. Cline: None.
miR-204 Antagomir Enhances GLP-1 Receptor Function and Glucose Control
Authors: JO SEONGHO , CHEN JUNQIN , XU GUANLAN , GRAYSON TRUMAN , THIELEN LANCE , SHALEV ANATH
Published: June 2018

Glucagon-like peptide 1 receptor (GLP-1R) is a G protein-coupled receptor that is highly expressed on pancreatic beta-cells and activated by endogenous incretins or antidiabetic GLP-1R agonist drugs. GLP-1R function is important in maintaining glucose homeostasis and involves stimulation of glucose-induced beta-cell insulin secretion via cAMP generation. While GLP-1R expression has been shown to be downregulated in diabetes, the molecular mechanisms have not been fully elucidated. In this study, we have discovered that miR-204, a highly beta-cell-enriched microRNA that is upregulated in diabetes, directly targets the 3’ UTR of GLP-1R and decreases its expression in INS-1 cells as well as primary mouse and human islets. Moreover, genetic knockout of miR-204 in vivo increased islet GLP-1R expression and enhanced GLP-1R agonist-induced cAMP production and insulin secretion, resulting in improved glucose tolerance as well as protection against diabetes. In addition, miR-204 antagomir administration was able to mimic the effects of genetic miR-204 deletion and resulted again in GLP-1R agonist-induced insulin secretion as well as improved glucose tolerance. Thus, these results indicate for the first time that GLP-1R is under the control of a micro RNA and suggest that antagomir-mediated inhibition of miR-204 represents a potential novel therapeutic approach to promote the actions of GLP-1R agonist drugs in a beta-cell-specific manner and thereby help treat diabetes.

Disclosure

S. Jo: None. J. Chen: None. G. Xu: None. T. Grayson: None. L. Thielen: None. A. Shalev: None.
Replication of Previously Type 2 Diabetes Associated Loci in 35,000 Samples of Korean Population
Authors: KIM YOUNG JIN , HWANG MI YEONG , SHIN DONG MUN
Published: June 2018

In the last decade, genome-wide association studies (GWAS) have revealed about hundreds of loci associated with type 2 diabetes(T2D) and related traits. However, most of loci have been discovered based on Europeans and a few GWAS conducted in populations with East Asian ancestry. To identify genetic variants responsible for complex traits such as T2D, obesity, and blood biochemical traits in Koreans, Korea Biobank Array(KBA) project was initiated in 2014. KBA is designed to contain about 830K tagging and functional variants optimized for Korean genome. In this study, quality controlled genotype data of about 35,000 samples was used. Among them, we conducted genome-wide association scan in 3,022 T2D case subjects and 27,195 control subjects. As a result, we replicated five previously known loci (CDKAL1, SLC30A8, CDKN2A, KCNQ1, and HNF1B) at genome-wide significance (P <= 5x10-8). We further compared genetic effects in Koreans with those of previously reported loci. As of March 2018, there were 373 unique variants of 50 T2D GWAS papers listed in GWAS catalogue. Among 373 variants, 359 variants were available after excluding variants with low imputation quality (<0.3). We compared odds ratios of 359 variants between KBA T2D GWAS and previously reported results. In overall, Pearson correlation coefficient of odds ratios was -0.04. For replicated results (130 variants with P<0.05 in KBA T2D GWAS), however, we observed high correlation (r<0.58). Our study identified five known T2D loci and confirmed consistent genetic effects across populations for 130 previously reported T2D associated variants. Further study is warranted to examine genetic diversity and lack of statistical power due to insufficient sample size in non-replicated loci. These results will be valuable scientific evidence in T2D precision medicine considering genetic effects across populations.

Disclosure

Y. Kim: None. M. Hwang: None. D. Shin: None.
Suicidal Screening in Youth with T1D—Risk or Benefit?
Authors: NAGRA HARPREET , DUKE DANNY C. , JONES MELINDA , KRAUS KIMBERLY , HARRIS MICHAEL A.
Published: June 2018

Objectives: Insulin access with intent to overdose coupled with limited forethought and higher impulsivity during childhood and adolescence, makes identification of suicidal ideation (SI) among youth with type 1 diabetes (T1D) of high importance. Correlations between SI and poor diabetes self-management have been identified, with 13% of adolescents with T1D endorsing SI in the last 12 months. The present study aimed to determine feasibility and effectiveness of screening for SI in youth with T1D.

Methods: Data were obtained during routine behavioral health screening of youth (ages 11-18) with T1D at a regional diabetes center. SI data were derived from question 9 of the Patient Health Questionnaire-9 (PHQ-9), “Thoughts that you would be better off dead or of hurting yourself in some way.”

Results: PHQ-9 was completed by a total of 587 pediatric patients (Males =289; Females =298) with a mean HbA1c of 9.1% (SD= 2.2). Findings suggest a significant relationship between gender and endorsement of SI with more females endorsing SI (n=52) than males (n = 26). SI was significantly and positively associated with HbA1c. Of the 13% of youth who screened positive for SI, 3/4 indicated SI for several days in the last 7 days and received an on-site behavioral health consultation. Approximately, 1/5 indicated SI for more than 1/2 of the days in the last week and received an onsite referral and a telephone follow-up, and 5% indicated SI nearly every day in the last week and received an on-site clinical assessment with one youth requiring emergency services.

Conclusions: SI screening in youth with T1D is necessary to address this concern. Results suggest our protocol was effective in identifying SI, allowed for rapid clinical assessment, and referral for additional care. In addition, SI rates in youth with T1D were consistent with the general population, suggesting that diabetes does not put youth at higher risk for SI, but imposes greater concern for suicide given the immediate availability of insulin.

Disclosure

H. Nagra: None. D.C. Duke: None. M. Jones: None. K. Kraus: None. M.A. Harris: Consultant; Self; Eli Lilly and Company.
Beneficial Effects of Tamoxifen Treatment in Type 1 Diabetes
Authors: ZHENG JUAN , ZAFAR MOHAMMAD ISHRAQ , CHEN LULU , GUO XIN , LI XIAOMING
Published: June 2018

Type 1 diabetes (T1D) results from the destruction of pancreatic β-cell through the β-cell specific autoimmune process. β-cell autoantigens, macrophages, dendritic cells (DC), B lymphocytes, and T lymphocytes have been implicated in the pathogenesis of autoimmune diabetes. Tamoxifen is a selective estrogen receptor modulators (SERM), used in the treatment of breast cancer. Research reports have shown that tamoxifen might decrease the strength of immune responses through modulation of DC differentiation and activation, and it may depress immunity. In NOD/ShiLtJ mice (female), which is a polygenic model for T1D, we found that tamoxifen exerts antidiabetic effects through acting on the immune system, leading to the suppression of insulitis and systemic inflammatory cytokine production in the in-vivo model. Tamoxifen therapy preserved the β-cell mass and prevented the development of T1D. Tamoxifen providing β-cell protection and immunoinhibitory effects offer a novel insight into the possible role of tamoxifen in the regulation of islet cell function and glucose homeostasis. These findings are significant and useful for clinical application.

Disclosure

J. Zheng: None. M. Zafar: None. L. Chen: None. X. Guo: None. X. Li: None.