bluuebunny/crossref_metadata_2025_split huggingface dataset:
2164-P: Paired Box 6 Modulates Pancreatic Beta-Cell Insulin Secretion through Regulation of Munc18-1/2 Expression: Involvement of CREB Signaling
Authors: SO WING YAN , HAN WEIPING 
Published: June 2019

The Paired box 6 (PAX6) transcription factor is crucial for normal pancreatic islet development and function. Heterozygous mutations of PAX6 are associated with impaired insulin secretion and early-onset diabetes mellitus in human. Previous studies demonstrated that PAX6 plays critical roles in insulin biosynthesis, glucose-sensing and glucose-induced ATP synthesis (the proximal signaling of insulin secretion). Yet the molecular mechanism of PAX6 in controlling beta-cell insulin secretion, especially the involvement of distal signaling, remains ambiguous. This study investigated the regulatory role of PAX6 in exocytotic proteins, the core components of distal signaling of insulin secretion, by using human pancreatic beta-cell line EndoC-bH1. The correlation between PAX6 and type 2 diabetes mellitus (T2DM)-associated beta-cell dysfunction was also assessed. Loss-of-function and gain-of-function studies showed that PAX6 positively regulated the expression of exocytotic proteins Munc18-1 and Munc18-2 in beta-cells by modulating the activity of cAMP response element-binding protein (CREB). The PAX6/CREB/Munc18-1/2 axis in turn controlled glucose-stimulated insulin secretion. On the other hand, EndoC-bH1 cells under diabetic condition displayed diminished PAX6 expression, blunted CREB phosphorylation and Munc18-1/2 down-regulation which were rescued by PAX6 overexpression. We conclude that PAX6 regulates distal signaling of insulin secretion through CREB/Munc18-1/2 axis; while maintenance of normal PAX6 expression or activity in human beta-cells may serve as a promising strategy in preserving beta-cell function and delaying the onset of T2DM.

Disclosure
W. So: None. W. Han: None.

Funding
National Medical Research Council of Australia
2166-P: Sel1L-Hrd1 ERAD Is a Key Regulator of Beta-Cell Function and Identity
Authors: SHRESTHA NEHA , LI XIN , JI YEWEI , REINERT RACHEL B. , ARVAN PETER , QI LING 
Published: June 2019

βcell survival and dedifferentiation are two hotly-debated mechanisms underlying βcell loss in type 2 diabetes; however, the underlying molecular mechanism remains largely unclear. Here we compare two principal protein quality control mechanisms, ER-associated protein degradation (ERAD) and autophagy and find that ERAD plays an important role in βcell dedifferentiation. Mice with βcell-specific Sel1L-Hrd1 deletion exhibit early-onset hyperglycemia and glucose intolerance as early as ~5 weeks of age. Surprisingly, in contrast to other tissue specific models of Sel1L-Hrd1 ERAD deficiency in which prohormones accumulate within the ER, Sel1L-Hrd1 ERAD deficiency impairs βcell function by attenuating insulin expression without an overt defect in proinsulin maturation and also triggers marked βcell dedifferentiation. There is, however, no overt activation of unfolded protein response (UPR) or proinsulin aggregation. In striking contrast to ERAD deficiency, loss of macroautophagy, a major mechanism for bulk protein degradation and organelle turnover, in βcells causes massive cell loss and hyperglycemia, but not βcell dedifferentiation. Thus, our data reveal a novel role of Sel1L-Hrd1 ERAD in the maintenance of βcell identify and demonstrate that impairment of ERAD contributes to the progression of type 2 diabetes in a manner distinct from that of autophagy.

Disclosure
N. Shrestha: None. X. Li: None. Y. Ji: None. R.B. Reinert: None. P. Arvan: None. L. Qi: None.

Funding
National Institutes of Health
2176-P: miRNA-374 Improves Glucotoxicity-Induced Beta-Cell Dysfunction and Glucose Metabolism Dysfunction through the Regulation of PGC-1 Alpha
Authors: KIM JIWON , YOU YOUNG HYE , LEE EUN YOUNG , YOON KUN-HO 
Published: June 2019

Glucotoxicity plays a major role in the progressive deterioration of β-cell function and development of type 2 diabetes mellitus. MicroRNAs (miRNAs) represent small noncoding RNAs that play a role in many diseases, including diabetes. This study was to search the common gene mechanism between liver and pancreas in diabetic condition such as glucotoxicity and to search the miRNAs related to glucotoxicity-induced β-cell dysfunction and glucose metabolism dysfunction in liver. To study the role of miRNAs in glucotoxicity-induced β-cell dysfunction and glucose metabolism dysfunction, we analyzed the miRNA expression patterns of primary rat islets and hepatocytes for three days after exposure to glucotoxicity and confirmed up-regulated and down-regulated miRNAs. Overexpression of miR-374 suppressed PGC-1α expression in glucotoxicity. miR-374 was found to target the 3'-untranslated region (3'UTR) of PGC-1α through miR-374 binding sites and to downregulated PGC-1α protein abundance at the post-transcriptional level by luciferase activity assay combined with mutational analysis. Here we demonstrate that miR-374 mediated suppression of PGC-1α gene expression is an important initiation step of glucotoxicity induced β-cell dysfunction and glucose metabolism dysfunction in liver and appropriate new target for early treatment.

Disclosure
J. Kim: None. Y. You: None. E. Lee: None. K. Yoon: Advisory Panel; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Merck Sharp & Dohme Corp., Novo Nordisk Inc. Speaker's Bureau; Self; Takeda Pharmaceutical Company Limited.
2177-P: Role of De Novo Sphingolipid Metabolites in Oleate-Induced Pancreatic ß-Cell Proliferation in Rats
Authors: CASTELL ANNE-LAURE , VIVOLI ALEXIS , MOULLÉ VALENTINE S. , GHISLAIN JULIEN , POITOUT VINCENT 
Published: June 2019

Fatty acids (FA) are major regulators of pancreatic β-cell function. In a rat model of nutrient excess we previously showed that FA potentiate glucose-induced β-cell proliferation. Sphingolipids, derived from the intracellular metabolism of FA, act as cellular mediators in the regulation of pancreatic β-cell function. However, the contribution of sphingolipid species to FA-induced β-cell proliferation is unknown.
Objective: To determine the role of de novo sphingolipid synthesis in FA-induced β-cell proliferation.
Methods: Isolated rat islets were exposed to oleate or palmitate (0.5 mM) in the presence of 16.7 mM glucose for 48h. Sphingosine kinase (SphK) 1 and 2 expression was measured by real-time PCR. Serine palmitoyl transferase (SPT), SphK, and the S1P3 receptor were inhibited with Myriocin, SKI II and TY52156, respectively. β-cell proliferation was assessed in cryosections by immunohistochemical detection of insulin and the proliferation marker Ki67 or by flow cytometry by labeling for C-peptide and EdU incorporation. Wistar rats were infused for 72 hours with glucose and a lipid emulsion (CLI) to induce β-cell proliferation.
Results: The monounsaturated FA oleate, but not the saturated FA palmitate, increased β-cell proliferation. Blocking de novo sphingolipid synthesis by SPT inhibition decreased oleate-induced β-cell proliferation as did inhibition of SphK and S1P3 receptor activation. Sphk1/2 mRNA levels in islets were not significantly changed following nutrient infusion in rats or FA exposure ex vivo.
Conclusion: β-cell proliferation in response to oleate requires de novo sphingolipid synthesis and S1P3 signaling. Analyses are underway to assess the contribution of SphK products sphingosine-1-phosphate and dihydrosphinganine-1-phosphate in S1P3-mediated β-cell proliferation.

Disclosure
A. Castell: None. A. Vivoli: None. V.S. Moullé: None. J. Ghislain: None. V. Poitout: None.

Funding
National Institutes of Health; Canadian Institutes of Health Research
218-LB: Hypoglycemia Burden in T2D Patients: Rationale, Methodology, and Comparative Results of a Multisetting Nationwide Study Series
Authors: ALÃO SÍLVIA , CONCEICAO SANTOS LELITA , ARAUJO FRANCISCO , DORES JORGE M. , PELICANO-ROMANO JOÃO , CONCEICAO JOAO M. , MJ PAULA 
Published: June 2019

Introduction: Hypoglycemia places a significant burden, accounting for adverse clinical and financial outcomes.
Objective: Integrated approach to determine burden of hypoglycemia in T2D patients in Portugal, accessed in an Outpatient Setting (pharmacies), Emergency Rooms (ERs) and Hospital Wards, contributing for a full country perspective of complementary settings.
Methods: A series of 3 HypoglycemIa in POrtugal Studies (HIPOS) were developed: HIPOS-PHARMA, HIPOS-ER and HIPOS-WARD. They were observational, cross-sectional, multicentric studies designed to evaluate adult T2D patients treated with AHA attending pharmacies and reporting hypoglycemic events (PHARMA), admitted in ERs or hospitalized (WARD) for hypoglycemia. These studies were implemented over a period of non-consecutive 35 months (Jan13-Aug18) and with a national coverage.
Results: Mild to moderate hypoglycemia in the 3 months prior recruitment were reported by 17.8% of the 1890 individuals enrolled by 233 pharmacies during HIPOS-PHARMA and were more likely in patients taking insulin and/or secretagogues. Only 46% of patients reported the episode to a HCP. Severe hypoglycemia accounted for 0.074% (n=238) of the 425,706 ER admissions in the 7 HIPOS-ER hospitals and occurred mainly on insulin- (55.0%) and secretagogue-based therapy (31.5%). When these patients needed hospitalization (44%), the mean total cost per hypoglycemic event was € 3,163 (€ 230 - € 26,818). As for HIPOS-WARD, 152 individuals were enrolled in 18 centers, 40.4% had previous hypoglycemia (last 12 months), and were also on insulin (42.1%) or secretagogues (34.9%).
Conclusion: This study series allowed for the first time a nationwide multi-setting perspective of hypoglycemia in T2D patients, signaling that this event still represents a relevant burden in Portugal, despite significant improvements in hypoglycemia prevention strategies and the growing number AHA with low hypoglycemia risk.

Disclosure
S. Alão: Employee; Self; Merck Sharp & Dohme Corp. L.C. Santos: Speaker’s Bureau; Self; Merck Sharp & Dohme Corp. F. Araujo: None. J.M. Dores: Advisory Panel; Self; Merck Sharp & Dohme Corp. J. Pelicano-Romano: Employee; Self; Merck & Co., Inc. J.M. Conceicao: Employee; Self; Merck Sharp & Dohme Corp. Stock/Shareholder; Self; Merck Sharp & Dohme Corp. P. Mj: Employee; Self; Merck Sharp & Dohme Corp.
2189-P: Human IAPP Destabilizes IRF1 Protein to Reduce PD-L1 Expression in INS1 Cells
Authors: MORITA SHUHEI , ISHIBASHI TATSUYA , ARIYASU HIROYUKI , IWAKURA HIROSHI , NISHI MASAHIRO , FURUTA HIROTO , AKAMIZU TAKASHI 
Published: June 2019

Background: Programmed death-ligand 1 (PD-L1) plays a critical role to protect β-cells against immune attack. Interferon regulatory factor 1 (IRF1) is a key transcriptional factor to regulate PD-L1 expression, which is induced by various cytokines through JAK/STAT pathway. Human islet amyloid polypeptide (hIAPP) activates resident macrophages to accelerate proinflammatory phenotype of islets. However, it is still unknown if hIAPP regulates the local inflammatory response in β-cells under immune attack. hIAPP knock-in mice induce diabetic phenotype only following high-fat feeding. In addition, most type 2 diabetic patients who have S20G-IAPP mutation show severe diabetic phenotype; however, other people who have it show only modest or no impairment of glucose tolerance. These evidences suggest that cytotoxic effect of hIAPP is not strong enough by itself, but may require another factor, like local immune dysregulation, to induce diabetic phenotype. These backgrounds encouraged us to investigate if and how hIAPP regulates IRF1/PD-L1 pathway in β-cells.
Methods: We evaluated the effect of hIAPP on IRF1/PD-L1 pathway by using recombinant rat(r) and human IAPP in INS1 cells. Doxycycline-inducible rIAPP- and hIAPP-overexpressing INS1 cells were used to confirm the results. Interferon (INF)-γ was used to activate JAK/STAT pathway.
Results: Recombinant hIAPP rather than rIAPP reduced endogenous and INF-γ-induced PD-L1 expression. Similarly, hIAPP-overexpression reduced PD-L1 expression. Recombinant both rat and human IAPP showed limited effect on phosphorylation of STAT1 and STAT3 induced by INF-γ. Protein levels of IRF1 induced by INF-γ were reduced by recombinant hIAPP; however, its mRNA levels were not reduced. Cycloheximide chase study revealed the destabilization of IRF1 protein under hIAPP treatment.
Conclusion: Our results suggest that hIAPP could destabilize IRF1 protein to reduce PD-L1 expression in INS1 cells.

Disclosure
S. Morita: None. T. Ishibashi: None. H. Ariyasu: None. H. Iwakura: None. M. Nishi: None. H. Furuta: None. T. Akamizu: None.
219-LB: Different Associations between Serum Urate and Diabetic Complications in Middle-Aged and Elderly Patients
Authors: WAN HENG , WANG YUYING , CHEN YI , WANG CHIYU , ZHANG WEN , XIA FANGZHEN , WANG NINGJIAN , LU YINGLI 
Published: June 2019

Aim: The objective of the study was to investigate whether higher serum urate (SUA) level has consistent association with cardiovascular disease (CVD), diabetic kidney disease (DKD) and diabetic retinopathy (DR) in Chinese adults with type 2 diabetes mellitus (T2DM).
Methods: 4,767 diabetic participants were enrolled from seven communities in Huangpu and Pudong District, Shanghai, China in 2018. Participants underwent several checkups, which included the measurement of anthropometric parameters, blood pressure, glucose, lipid profiles, SUA and urine albumin/creatinine ratio (ACR).
Results: Compared with the first SUA group, the third group increased the prevalence of CVD by 27% (OR 1.27; 95% CI 1.04, 1.55) (P for trend &lt;0.05) and increased the prevalence of DKD by 88% (OR 1.88; 95% CI 1.48, 2.40) for KDOQI definition. Compared with first group, OR (95% CI) of DR ranging from non-retinopathy (NDR) to proliferative diabetic retinopathy (PDR) in ordinal logistic regression associated with SUA level was 0.81 (0.59, 1.10) for the third group, (P for trend=0.086) and OR (95% CI) of the number of diabetic complications ranging from 0 to 2 in ordinal logistic regression associated with SUA level was 1.75 (1.44, 2.12) for the third group (P for trend&lt; 0.01). These associations were all full adjusted.
Conclusions: Higher SUA level was associated with increased odds of CVD, DKD and variety of the diabetic complications, not DR, in middle-aged and elderly diabetic Chinese adults, which means lowering SUA level may be critical for prevention and intervention of diabetic complications.

Disclosure
H. Wan: None. Y. Wang: None. Y. Chen: None. C. Wang: None. W. Zhang: None. F. Xia: None. N. Wang: None. Y. Lu: None.
2195-P: Identification of the Regulatory Mechanism of mTORC1 Signaling Activity in Pancreatic Beta Cells in GCN2 Knockout Mice
Authors: KUDO MICHIYO , ASAHARA SHUN-ICHIRO , KANNO AYUMI , KIDO YOSHIAKI 
Published: June 2019

Background and Objective: A single-nucleotide polymorphism (SNP) analysis of Japanese type 2 diabetes (T2DM) patients has revealed a significant correlation between a SNP of GCN2 and T2DM. We have demonstrated that islets isolated from GCN2 knockout (GCN2-/-) mice fed a high-fat diet (HFD) exhibited decreased expression of ATF4, a downstream molecule of GCN2, and pancreatic β-cell failure via hyperactivation of mTORC1 signaling. However, the mechanism of activated mTORC1 signaling has remained unclear. Therefore, our objective is to identify the regulatory mechanism of mTORC1 signaling activity in pancreatic β-cells of GCN2-/- mice fed an HFD.
Methods: We analyzed using islets isolated from GCN2-/- mice and wild type mice fed an HFD, and pancreatic β-cell lines.
Results: In pancreatic islets isolated from GCN2-/- mice fed an HFD, the phosphorylation of TSC2 was enhanced. Therefore, we speculated that there would be a pathway which regulated mTORC1 signaling via TSC2. It has been reported that TSC2 phosphorylation is regulated by its association with 14-3-3. We started to identify the molecule X downstream of GCN2, which involved in the regulation of mTORC1 signaling activity by competitively inhibiting the binding of TSC2 and 14-3-3. We carried out a proteome analysis to explore the molecules whose binding with 14-3-3 varied depending on the presence or the absence of GCN2. As a result, five molecules were listed, and Asparaginase was identified as the candidate of the molecule X. We revealed that Asparaginase was abundantly expressed in pancreatic islets following heart in mice tissues. In glucose loaded MIN6 cells and amino acid deficient MIN6 cells, the expression of Asparaginase was increased. Furthermore, the increased expression of Asparaginase by amino acid deficiency was decreased by ATF4 knocking down.
Conclusion: It was suggested that Asparaginase was involved in the regulation of mTORC1 signaling activity downstream of GCN2-ATF4 pathway.

Disclosure
M. Kudo: None. S. Asahara: Research Support; Spouse/Partner; AstraZeneca. A. Kanno: None. Y. Kido: Research Support; Self; AstraZeneca.
22-LB: Baseline and Short-Term Change in Plasma Uric Acid on Fenofibrate Predict Cardiovascular Risk: A Post Hoc Analysis of FIELD
Authors: YIMING CAO JACOB , WALDMAN BORIS , OCONNELL RACHEL L. , SULLIVAN DAVID , GEBSKI VAL , JANUSZEWSKI ANDRZEJ S. , MARSCHNER IAN , SCOTT RUSSELL , TASKINEN MARJA-RIITTA , SIMES R. JOHN , MCGILL NEIL , JENKINS ALICIA J. , KEECH ANTHONY C. 
Published: June 2019

Background: Fenofibrate increases renal clearance of uric acid (UA). Relationships between baseline and short-term changes in plasma UA with fenofibrate and subsequent cardiovascular risk in patients with type 2 diabetes (T2D) are unknown.
Method: Post hoc analyses of the FIELD trial explored the relationships between CVD events and 1) baseline UA level; and 2) short-term change in UA level over 6-week single-blind active fenofibrate run-in.
Results: The FIELD trial showed 11% fewer cardiovascular events in patients with T2D assigned to fenofibrate compared to placebo over 5 years (HR = 0.89, 95% CI: 0.80-0.99, p = 0.035). Baseline UA (n=9622) ranged between 0.11 to 0.79 mmol/L (mean = 0.33, SD = 0.078). Each 0.1 mmol/L higher baseline UA increased CVD events by 21% (HR = 1.21 95% CI: 1.13-1.29, p &lt; 0.001; Fig. 1A), and remained after adjusting for other classic risk factors (HR = 1.12, 95% CI: 1.04-1.21, p = 0.002). Fall in UA level with fenofibrate run-in also predicted lower CVD risk, adjusted for baseline UA and irrespective of trial treatment allocation (HR = 0.86, 95% CI: 0.76-0.97, p = 0.015; Fig. 1B).
Discussion: Baseline and short-term fenofibrate-induced lowering of UA predict cardiovascular risk in patients with T2D, irrespective of long-term trial treatment allocation. The reduction in total CVD events with fenofibrate was not shown to be mediated through lowering of UA levels.

Disclosure
J.Y. Cao: None. B. Waldman: None. R.L. OConnell: None. D. Sullivan: None. V. Gebski: None. A.S. Januszewski: None. I. Marschner: None. R. Scott: None. M. Taskinen: Advisory Panel; Self; Novo Nordisk A/S. Consultant; Self; Akcea Therapeutics, Chiesi USA, Inc. Research Support; Self; Amgen Inc., Novo Nordisk A/S. Speaker’s Bureau; Self; Amgen Inc. R. Simes: None. N. McGill: None. A.J. Jenkins: Advisory Panel; Self; Abbott, Australian Diabetes Society, Medtronic. Research Support; Self; Abbott, GlySens Incorporated, Medtronic, Mylan. Speaker’s Bureau; Self; Eli Lilly and Company, Novo Nordisk Inc. A.C. Keech: None.
2202-PUB: Time in Hypoglycemia Recorded by Continuous Glucose Monitoring in Subjects with Type 1 Diabetes in a Single Center in Costa Rica
Authors: CALVO JAVIER 
Published: June 2019

Glycemic variability and frequent hypoglycemic episodes are some of the most difficult issues in the management of type 1 diabetes (T1D). We performed a retrospective analysis that included 27 subjects from 13 to 54 years of age diagnosed with T1D, using a multiple daily insulin injection treatment and under continuous glucose monitoring with a Medtronic iPro2 device for six days. We divided the sample in two groups: A) those with 10% or less of the time in hypoglycemia and B) those with more than 10% of time in hypoglycemia. Their median age was 27.8 years, 48.1% were males, with a median duration of disease of 13 years and a median of A1C of 7.8%. The time in range (blood glucose from 70 to 180 mg/dL) was 44% in both groups. The group of patients with more than 10% of the time in hypoglycemia had a lower A1C (7.5 vs. 7.9%, p=0.034) along with a higher number of hypoglycemic episodes in the night time (0 vs. 3, p&lt;0.001), as well as increased episodes during the entire day (2 vs. 12.0 p&lt;0.001). Patients who spent more time in range also showed lower levels of A1C, although all of them had more than 10% of time in hypoglycemia.
In conclusion, adequate A1C levels do not assure adequate control of disease given the increased time in hypoglycemia observed in this set of patients.
Figure 1. Correlation Between Mean A1c and Time in Range in Patients with T1D A1C, Glycated Hemoglobin; SD, Standard Deviation.

Disclosure
J. Calvo: None.
2207-PUB: Does Hypoglycemia Increase the Risk of Cardiac Arrhythmia?
Authors: MUSSO CARLA , SFORZA NOELIA S. , MOROSAN ALLO YANINA JIMENA , CLEMENTE ROMINA G. , PAVESI ADRIAN , FOLINO CLAUDIA C. 
Published: June 2019

Hypoglycemia may exert proarrhythmogenic effects on the heart and insulin induced hypoglycemia has been considered responsible for nocturnal death in diabetic patients. Even so hypoglycemia associated fatal cardiac arrhythmia is difficult to document.
Objective: examined the effect of hypoglycemia on episodes of arrhythmias and cardiac repolarization disorders in diabetic mellitus (DM) patients.
Design and Methods: prospective study in which we included 30 subjects with DM who underwent of simultaneous ambulatory 24 hours electrocardiographic holter and continuous interstitial glucose monitoring (FREE STYLE system). Inclusion criteria: men and women &gt; or = 50 years old with a type 2 insulin-treated DM and 2 or more major cardiovascular risk factors (hypertension, dyslipidemia, active smoking, overweight or obesity) or subjects older than 18 years old with a history of type 1 DM of more than 10 years who sign an informed consent. Exclusion criteria: pacemakers, treatment with drugs that prolong QT, chronic atrial fibrillation or branch blocks, previous stroke, heart failure stage III-IV, Wolf Parkinson White Syndrome.
Results: A total of 30 patients with DM participated in this study; 14 patients with type 1 DM (46.67%) and 16 patients with type 2 DM (53.33%). Within the group of type 1 DM, 61.54% presented hypoglycemic events vs. 56.25% of the patients in type 2 DM group, (p= 0.774) which correlates with the increased risk of hypoglycemic events in type 1 DM group. A total of 60% of the patients presented hypoglycemic events (n= 18) independently of glucose levels, and 40% of the patients (n=12) did not present it. Most of the hypoglycemic events (72.22% p=0.035) did not correlate with an arrhythmia event or cardiac repolarization disorder.
Conclusions: In our group of patients, high cardiovascular risks and long-term duration of type 1 or type 2 DM were strong enough factors to develop arrhythmia, independently of glucose levels. Maybe it would be necessary to study patients with a 48-hour holter in order to find out this association.

Disclosure
C. Musso: None. N.S. Sforza: None. Y.J. Morosan Allo: None. R.G. Clemente: None. A. Pavesi: None. C.C. Folino: Other Relationship; Self; Boehringer Ingelheim Pharmaceuticals, Inc.