bluuebunny/crossref_metadata_2025_split huggingface dataset:
338-LB: ACh Esterase Is a Novel Regulator of Insulin Secretion in Human Islets
Authors: TAMAYO ALEJANDRO M. , CAICEDO ALEJANDRO 
Published: June 2019

The neurotransmitter acetylcholine (ACh) plays a major role in regulating insulin secretion. While in several species parasympathetic innervation provides cholinergic input to beta cells, it is the glucagon secreting alpha cell the major source of ACh in human islets. It is still unclear, however, what is the contribution of cholinergic signaling to beta cell function in humans. Here we analyzed how ACh impacts human beta cell function and insulin secretion, using a combination of in vitro and in vivo approaches. To determine the effect of endogenous ACh in insulin secretion, we manipulated ACh esterase activity using different inhibitors such as pyridostigmine and galantamine. Inhibition of ACh esterase led to a significant increase in insulin secretion in isolated human islets in perifusion experiments. To assess the effect of endogenous ACh on human beta cell function in vivo, we transplanted human islets into the anterior chamber of immunocompromised Nude mice. ACh esterase activity was inhibited by local administration of the ACh esterase inhibitor pyridostigmine as eye drops. To control that the inhibitor was entering the anterior chamber of the eye and reaching the islets, we measured the effect it had on pupil size. 30 microM pyridostigmine induced approximately a 20-30% reduction in pupil size. Importantly, mice treated with 30 microM pyridostigmine showed decreased glucose excursion curves and slightly increased insulin levels 15 min after glucose injection. These results indicate that endogenously released ACh from human alpha cells increases insulin secretion from beta cells in vitro and in vivo. ACh esterase is potential novel target for the treatment of diabetes in humans.

Disclosure
A.M. Tamayo: None. A. Caicedo: None.

Funding
American Diabetes Association (1-17-ICTS-052 to A.C.)
339-LB: Modulation of Insulin and Glucagon Secretion by Optogenetic Control of Delta-Cell Electrical Activity in Pancreatic Islets
Authors: DOU HAIQIANG , MIRANDA CAROLINE A. , ZHANG QUAN , RORSMAN PATRIK , TOLö JOHAN 
Published: June 2019

Somatostatin secreted from pancreatic delta-cells is a strong paracrine inhibitor of both insulin and glucagon secretion in islets. However, little is known about the regulatory mechanisms of delta cells. This is mainly due to the scarcity of these cells (∼5-10% of islet cell population) and difficulties in maintaining their morphology and function after cell dispersion. Here, we developed an optogenetic approach, through tissue-specific expression of light-sensitive channels in delta cells, to investigate the paracrine modulation of alpha/beta cells by delta cells within intact islets. We generated a mouse model using Cre-loxp recombination to enable the specific expression of a light-sensitive cation channel Channelrhodopsin-2 (ChR2) in the pancreatic delta cells (SST-ChR2 mouse). In the presence of 1 mM glucose (when ?-cells are not electrically active), light activation of ChR2 (with 470 nm LED light) rapidly depolarised delta- cells (from -66±4 mV to -19±2 mV, n=4). Similar depolarising effect was observed in delta-cells exposed to 10 mM glucose (from -59±5 mV to -19±4 mV, n=4). Delta-cells activation with light transiently repolarised alpha cells by 5 mV (n=2) at 1 mM glucose and beta cells by 4 mV (n=3) at 10 mM glucose, which correlated with a mild decrease in intracellular Ca2+ concentration. Optoactivation of delta-cells inhibited glucagon secretion in islets exposed to 1 mM glucose by 48%. Whilst not affecting that at 20 mM glucose. Interestingly, despite the effects on beta-cell membrane potential, light exposure to SST-ChR2 islets did not affect insulin secretion stimulated by 20 mM glucose, possibly suggesting that insulin secretion is already maximally inhibited by glucose-induced somatostatin secretion. We propose that the SST-ChR2 mouse model represents a powerful tool for studying spatial and temporal paracrine crosstalk between different islet cells and the role of somatostatin in islet hormone secretion.

Disclosure
H. Dou: None. C.A. Miranda: None. Q. Zhang: None. P. Rorsman: None. J. Tolö: None.

Funding
Swedish Research Council
344-LB: A Highly Specific Chemiluminescent Assay That Accurately Measures Human and Rodent Glucagon
Authors: CAILLOUETTE CHRISTIANN , MCDERMOTT BRENDA K. , CACICEDO JOSE M. , BELL BETHANY , WISHERD CHRIS 
Published: June 2019

Glucagon is a hormone generated as a result of post translational modifications during proglucagon processing. The hormone's amino acid sequence is found in several proglucagon peptides, including the hormones glicentin and oxyntomodulin. In addition, glucagon’s sequence is similar to incretin hormones such as glucagon-like peptide-1 (GLP-1). The similar sequence homology between glucagon and these peptide hormones has created challenges in specifically measuring glucagon concentrations. Current commercially available glucagon assays have been proven to cross-react with oxyntomodulin, glicentin, and other proglucagon peptides. In addition, researchers often report higher cross-reactivity values than the manufacturers, which further complicates accurately measuring glucagon levels. To address this need, ALPCO has developed the STELLUX® Chemi Glucagon ELISA for the quantitative determination of glucagon in EDTA plasma and cell culture samples. This assay has an excellent sensitivity and is capable of measuring post-prandial glucagon levels in both rodents and humans. Most importantly, this assay specifically measures glucagon without any cross-reactivity to other proglucagon peptides including glicentin and oxyntomodulin. In the current study, ALPCO’s ELISA was compared to competitor A’s ELISA to further investigate how differences in specificity contribute to final calculated concentrations of the analyte. A panel of 16 samples of human, mouse, and rat EDTA plasma were assayed on both products and an overall R2 of 0.988 and slope of 1.337 was shown. The consistently higher recovery in values using the competitor ELISA may be explained through its known cross-reactivity with oxyntomodulin and/or glicentin. However, the correlation between the two assays would allow for a seamless transition from the competitor ELISA to the ALPCO ELISA within or between projects.

Disclosure
C. Caillouette: Employee; Self; Alpco. B.K. McDermott: None. J.M. Cacicedo: Employee; Self; Alpco. B. Bell: Employee; Self; Alpco. C. Wisherd: Employee; Self; Alpco.
346-OR: Primary Care Implementation Study to Increase Diabetes Prevention Program Referrals
Authors: KECK JAMES W. , ROPER KAREN L. , THOMAS ALISHA , HIERONYMUS LAURA 
Published: June 2019

Background: Intensive lifestyle change programs effectively prevent or delay type 2 diabetes but are underutilized. We evaluated patient and clinician prediabetes attitudes and practices and implemented strategies to increase National Diabetes Prevention Program (DPP) referrals.
Methods: The Tailored Implementation for Chronic Diseases framework guided data collection and the interventional approach of our cluster randomized implementation study across two large primary care clinics. Formative data came from clinician surveys, patient focus groups, and electronic health record (EHR) review. Thematic qualitative and descriptive quantitative analyses identified implementation opportunities. Intervention clusters (family medicine teams) received clinician detailing and EHR-guided prediabetes patient identification. All clusters (family medicine and internal medicine) had access to an electronic DPP referral process. The primary outcome was DPP referral.
Results: Focus group participants (3 groups, 15 participants) had mixed perceptions of prediabetes risk and desired personalized behavior change guidance. Surveyed clinicians (31 respondents of 45 invited) viewed prediabetes care positively, but had low DPP awareness. Baseline pre-implementation EHR data for two years (15,520 adult patients) revealed A1c screening coverage of 75.9% per national guidelines. Documentation of prediabetes occurred in 50.7% (729/1,437) of patients meeting A1c criteria. Interim analysis of DPP referrals 8 months post-intervention found 4.8% (69/1,423) of diagnosed prediabetes patients received DPP referral in intervention clusters versus 0.7% (17/2,357) of diagnosed prediabetes patients in control clusters. Patients with prediabetes in intervention clusters had 3.32 (95% CI: 0.89, 12.35) odds of receiving DPP referral after covariate and clustered data adjustments.
Conclusions: Clinician detailing and EHR patient identification increased DPP referrals.

Disclosure
J.W. Keck: None. K.L. Roper: None. A. Thomas: None. L. Hieronymus: None.

Funding
National Center for Research Resources; National Center for Advancing Translational Sciences (UL1TR001998)
35-LB: Response to Anti-VEGF Therapy in a Nonhuman Primate Model of Diabetic Macular Edema
Authors: CHIA SER MIEN , GONG LI , TIU SARAH , CONARELLO STACEY L. , BELLUM SAIRAM , PAN LINGZHEN , LEE CHEN FEI , ALI ASAD ABU BAKAR , HONG LEWIS , ZENG WEN , CHIN CHIH-LIANG , LI NINA X. 
Published: June 2019

Diabetic macular edema (DME) is one manifestation of diabetic retinopathy (DR), where fluids leak from the retinal vessels into the centre of the macula, causing swelling and blurred vision. VEGF inhibitors (e.g., ranibizumab), have demonstrated clinical efficacy in treating DME; however, it is known that ∼50% of patients do not respond to anti-VEGF therapy. Therefore, DME remains an unmet medical need. To discover novel therapies for DME, animal models that recapitulate clinical phenotypes and validated with anti-VEGF drugs will be of importance. Rodent models of DR have been developed using chemical or dietary induction to mimic the pathophysiological features observed in human. However, differences in the structural and biochemical characteristics of the visual system between rodents and humans hamper their clinical translation. Herein, we aimed to determine the effect of intravitreal administration of ranibizumab in aged, spontaneously dysmetabolic non-human primate with increased average retinal thickness (329 ± 6 µm, vs. age-matched controls 299 ± 10 µm). Seven of them showed signs of non-proliferative DR (NPDR) with presence of intra-retinal cysts, exudates or micro-aneurysms. Changes in retinal thickness and vascular leakage were measured by optical coherence tomography and fluorescein angiography, respectively. Plasma and vitreous levels of VEGF were also determined. Longitudinal data measured over 3-mo. period demonstrated modest, statistical insignificant reduction in average retinal thickness, plasma and vitreous VEGF levels. Some NPDR animals did showed potential improvement in vascular leakage. Considering anti-VEGF drugs are mostly effective in severe DR/DME patients, our results might be reconciled with the early stage of disease condition ascribed to these animals. Further investigation is needed to better understand heterogeneity of individual animal’s drug response and the relationship among imaging, plasma, and vitreous readouts in a longitudinal manner.

Disclosure
S. Chia: None. L. Gong: None. S. Tiu: Employee; Self; Merck Sharp & Dohme Corp. S.L. Conarello: None. S. Bellum: None. L. Pan: None. C. Lee: None. A. Abu Bakar Ali: Employee; Self; Merck & Co., Inc. L. Hong: Employee; Spouse/Partner; Illumina, Inc. Employee; Self; Merck Sharp & Dohme Corp. Stock/Shareholder; Spouse/Partner; Illumina, Inc. Stock/Shareholder; Self; Merck Sharp & Dohme Corp. W. Zeng: None. C. Chin: None. N.X. Li: Employee; Self; Merck & Co., Inc.
355-OR: Is Classification of GDM Phenotypes Dependent on Ethnicity?
Authors: GIBBONS KRISTEN S. , MCINTYRE DAVID , MA RONALD C. , TAM WING , MADSEN LENE R. , SACKS DAVID A. , CATALANO PATRICK 
Published: June 2019

Clinical experience suggests that diverse clinical phenotypes exist within the broader diagnosis of GDM. Recent published analysis from a single center outlined heterogeneity in GDM with respect to insulin secretion and sensitivity, defining four GDM phenotypes: 1) GDMsecr (&lt;25th centile HOMA-β for non-GDM); 2) GDMsens (&lt;25th centile Matsuda Index for non-GDM); 3) GDMmixed (both GDMsecr and GDMsens); 4) no defect (neither GDMsecr and GDMsens). Classification using these phenotypes is associated with adverse outcomes. It is unknown whether adjustment for ethnicity may provide stronger associations with outcome prediction. Using data from 5 centers in the HAPO study, GDM women were classified into one of four phenotypes in two ways: 1) whole sample cut-offs; and 2) ethnic-specific glycemic thresholds. Descriptive characteristics were compared between the five groups (four GDM phenotypes + non-GDM), and multivariable analysis adjusted for BMI, center and key demographic and clinical characteristics. Of the 6128 women, 2442 (40%) were caucasian, 294 (4.8%) black, 1556 (25.4%) Hispanic, 1616 (26.4%) Asian and 220 (3.6%) other ethnicity; ethnicity was closely related to study center. Seventeen percent were classified as GDM (n=1047), with slightly higher GDM frequency for black (20.1%) and Hispanic women (23.3%). There was 83.9% agreement between whole-sample and ethnic-specific classification into GDM phenotypes. There was a significant relationship (p&lt;0.05) between one or more GDM phenotypes and LGA, primary CS, neonatal hyperinsulinemia and/or fetal adiposity. Despite minor changes in the adjusted odds ratios, there were no statistically significant changes in the relationship between GDM phenotype and outcome when comparing whole sample cut-offs and ethnic-specific cut-offs. Where available, ethnic-specific cut-offs should be used to define GDM phenotype to assist in identifying GDM women at higher risk of adverse outcome, however whole-sample cut-offs can be used with confidence in their absence.

Disclosure
K.S. Gibbons: None. D. McIntyre: None. R.C. Ma: Advisory Panel; Self; Boehringer Ingelheim International GmbH. Research Support; Self; AstraZeneca, Bayer AG, Pfizer Inc. Stock/Shareholder; Self; GemVCare. Other Relationship; Self; AstraZeneca. W. Tam: None. L.R. Madsen: None. D.A. Sacks: None. P. Catalano: None.
356-OR: Effects of First Trimester Exercise on Pregnancy Hyperglycemia and GDM
Authors: EHRLICH SAMANTHA F. , NEUGEBAUER ROMAIN , FENG JUANRAN , HEDDERSON MONIQUE M. , FERRARA ASSIAMIRA 
Published: June 2019

Structured, exercise-only interventions reduce the odds of GDM, but motivated trial participants are likely unrepresentative. Studies of free living exercise in population-based cohorts are needed and causal inference methods, which emulate randomized trials under specific a priori assumptions, represent the best alternative for observational data. This study estimates the causal effects of first trimester exercise on the risks of abnormal screening after a 50-OGTT, GDM diagnosed by the Carpenter-Coustan criteria, and abnormal glucose according to the Carpenter-Coustan thresholds for the 100-g OGTT. Data come from PETALS, a prospectively followed pregnancy cohort (n= 2,070, 70% from minority racial-ethnic groups) receiving care at Kaiser Permanente Northern California in 2013-2017. A Pregnancy Physical Activity Questionnaire was completed at 12.8 weeks gestation, on average (SD 2.5). Targeted Maximum Likelihood with data-adaptive estimation (a.k.a., machine learning) of propensity scores and outcome regression with recognized confounders (e.g., prepregnancy BMI, diet, education) was used to obtain causal risk differences for all women having exercised versus not. Exercise was defined as performing any amount of vigorous intensity exercise or meeting the cohort’s 75th percentile for moderate to vigorous intensity exercise (MVPA; ≥ 13.3 MET hours per week). The prevalence of abnormal screening was 23.8% and GDM 6.2%. Any participation in vigorous exercise significantly decreased the risk of GDM by 1.6 fewer cases per 100 women, and abnormal 1-hour and 2-hour OGTT values by 2.7 and 1.8 fewer cases, respectively, per 100 women. Meeting the 75th percentile for MVPA significantly decreased the risks of abnormal screening and abnormal 2-hour OGTT values by 5.2 and 2.5 fewer cases per 100 women, respectively. Findings suggest that, during the first trimester, any amount of vigorous intensity exercise or a high volume of moderate to vigorous intensity exercise reduces hyperglycemia later in pregnancy.

Disclosure
S.F. Ehrlich: None. R. Neugebauer: None. J. Feng: None. M.M. Hedderson: None. A. Ferrara: None.

Funding
National Institute of Diabetes and Digestive and Kidney Diseases (K01DK105106, P30DK092924); National Institute of Environmental Health Sciences (R01ES019196)
361-OR: ER Stress Attenuation Is Involved in PAHSA-Induced Reduction of T1D in Nonobese Diabetic (NOD) Mice
Authors: SYED ISMAIL , DE CELIS MARIA FERNANDEZ RUBIN , MOHAN JAMES F. , MORAES-VIERIA PEDRO M. , VIJAYAKUMAR ARCHANA , NELSON ANDREW T. , SIEGEL DIONICIO , SAGHATELIAN ALAN , MATHIS DIANE , KAHN BARBARA 
Published: June 2019

Palmitic Acid esters of Hydroxy Stearic Acids (PAHSAs) are endogenous lipids with antidiabetic and anti-inflammatory effects. We found that PAHSAs protect against T1D by attenuating autoimmune responses and by direct effects on islets. We aimed to determine the mechanisms by which PAHSAs directly promote β-cell survival. Daily oral gavage of PAHSAs in NOD mice starting at 4 or 13 weeks of age delays T1D onset and reduces T1D incidence from 82-90% of mice with vehicle to 35-40% of mice receiving PAHSAs. PAHSA treatment reduces leukocyte infiltration into islets by 50% and reduces T cell activation. PAHSA-treated mice had greater β-cell area relative to total islet area (vehicle 60±7 vs. PAHSA 77±1). PAHSAs enhance β-cell proliferation in NOD mice 5 fold vs. vehicle. PAHSA-treated NOD mice pancreata have lower ER stress markers, CHOP and XBP-1 (vehicle 68±12 vs. PAHSA 42±3), and higher insulin (vehicle 12±2 vs. PAHSA 17±1) immunostaining intensities per β-cell area. PAHSAs attenuate thapsigargin-induced PARP cleavage by 55% in human islets, and JNK1/2 phosphorylation by 40% in MIN6 cells. Also, PAHSAs attenuate apoptotic and necrotic β-cell death under cytokine stress and increase β-cell viability by 34% and proliferation by 31% (p&lt;0.002). Since GLP-1 receptor (GLP-1R) antagonism causes β-cell death and G-protein coupled receptor GPR40 plays a vital role in β-cell function, we assessed if PAHSA beneficial effects on β-cell survival involve these pathways. In vitro, GLP-1R antagonism lowered PAHSA protective effects on β-cell viability by 53% and proliferation by 44% (p&lt;0.005) under cytokine stress but GPR40 antagonism had no effect.
Conclusion: In addition to attenuating immune responses, PAHSAs delay the onset and reduce T1D incidence in NOD mice through direct effects. PAHSAs directly reduce cytokine-induced β-cell death and increase cell proliferation in autoimmune diabetes through mechanisms involving ER stress reduction. This appears to be mediated in part by GLP-1R and not by GPR40.

Disclosure
I. Syed: None. M. Fernandez Rubin de Celis: None. J.F. Mohan: None. P.M. Moraes-Vieria: None. A. Vijayakumar: None. A.T. Nelson: None. D. Siegel: None. A. Saghatelian: None. D. Mathis: None. B. Kahn: Advisory Panel; Self; Alterna Therapeutics, Inc., American Diabetes Association, Harrington Discovery Institute, Janssen Research & Development. Consultant; Self; Ironwood Pharmaceuticals, Inc. Research Support; Self; National Institute of Diabetes and Digestive and Kidney Diseases.

Funding
National Institutes of Health (R01DK43051, P30DK57521 to B.K.), (R01DK106210 to B.K., A.S.), (K01DK118041 to I.S.); JPB Foundation (to B.K., D.M.); Deutsche Forschungsgemeinschaft (to M.F.R.)
364-OR: Beta-Cell Glucose-Regulated Micropeptide 1 (BGRM1) Controls Cellular Homeostasis in Pancreatic Beta Cells
Authors: LI MARK , SHAO FAN , SWEAT MASON E. , QIAN QINGWEN , GUO YUWEI , STEPHENS SAMUEL B. , IMAI YUMI , YANG LING , CAO HUOJUN 
Published: June 2019

Accumulating evidence demonstrates that certain types of long-noncoding RNAs (lncRNA) encode very short open reading frames, called micropeptides. By regulating larger protein complexes, these micropeptides can regulate fundamental biological processes such as skeletal muscle development and cell migration. However, the ability of micropeptides to maintain cellular and metabolic homeostasis in islets is unknown. Using a bioinformatics approach, we comprehensively analyzed the protein-coding potential of lncRNAs that are expressed in the human pancreas, and identified more than 30 that likely encode micropeptides. We further characterized one conserved IncRNA that encodes a 65-amino-acid micropeptide, which we named beta cell glucose regulated micropeptide 1 (BGRM1). We found that BGRM1 expression was altered in islets from obese or diabetic humans and mice. Overexpression of BGRM1 elevated glucose-stimulated insulin production in INS-1 cells and in islets from humans and mice. BGRM1 promotes endoplasmic reticulum (ER) calcium efflux and enhances cytosolic calcium levels, which suggests it mediates insulin production is in part by modulating intracellular calcium homeostasis. This notion is further supported by our mass spectra analysis that reveals several BGRM1 binding partners involved in ER calcium homeostasis in beta cells. Notably, BGRM1 is localized in the ER and protects beta cells from ER stress. Taken together, our study provides the first evidence that lncRNA encoded micropeptides play a critical role in pancreatic beta cell function. These results provide a foundation on which to perform future comprehensive analyses of micropeptide function and pathophysiological impact on diabetes.

Disclosure
M. Li: None. F. Shao: None. M.E. Sweat: None. Q. Qian: None. Y. Guo: None. S.B. Stephens: None. Y. Imai: None. L. Yang: None. H. Cao: None.
367-P: Severe Hypoglycemia and Risk of Falls in Type 2 Diabetes: The Atherosclerosis Risk in Communities (ARIC) Study
Authors: LEE ALEXANDRA K. , JURASCHEK STEPHEN P. , WINDHAM B. GWEN , LEE CLARE , SHARRETT A. RICHEY , CORESH JOSEF , SELVIN ELIZABETH 
Published: June 2019

Diabetes is common among older adults and is associated with greater risk of falls, which can be fatal in this population. One hypothesized link between diabetes and falls is hypoglycemia. However, this has not been evaluated in an older, type 2 diabetes population. We included 1186 ARIC participants with diabetes at Visit 4 (1996-1998) followed through 2013 for severe hypoglycemia and falls. We identified severe hypoglycemia with ICD-9 codes in claims for hospitalization, emergency department and ambulance use. Falls were based on E-codes in inpatient and outpatient claims; secondary outcomes were hospitalized falls and falls with fracture. We used adjusted Cox regression models to evaluate the association of severe hypoglycemia as a time-varying exposure with risk of subsequent fall. Participants had a mean age of 64, 54% female, 32% black; 14 had hypoglycemia prior to baseline and 135 had a severe hypoglycemic episode during follow-up. The crude incidence rate of falls without severe hypoglycemia was 2.17 per 100 person-years (PY) (95% CI: 1.93-2.44) and 8.81 per 100PY (6.73-11.53) with severe hypoglycemia. After adjustment, hypoglycemia was associated with an over two-fold greater risk of falls (Table). Fall history and risk should be considered when deciding glycemic goals and medication use, as hypoglycemia may increase fall risk.

Disclosure
A.K. Lee: None. S.P. Juraschek: None. B. Windham: None. C. Lee: Consultant; Self; XOMA Corporation. Research Support; Self; Eiger BioPharmaceuticals. A. Sharrett: None. J. Coresh: None. E. Selvin: None.

Funding
National Institutes of Health