bluuebunny/crossref_metadata_2025_split huggingface dataset:
2037-P: Islet ß-Cell Dedifferentiation Is Involved in Progression of Type 2 Diabetes
Authors: AMO-SHIINOKI KIKUKO , TANABE KATSUYA , BOUCHI RYOTARO , NISHIMURA WATARU , OGAWA YOSHIHIRO , TANIZAWA YUKIO 
Published: June 2020

T2D is associated with deficits of β-cell function and number. But it remains unclear how these processes interact during disease progression. It has been described that islet cell plasticity, i.e., β-cell dedifferentiation and conversion into other islet cells, is implicated to β-cell failure in murine diabetes of insulin resistance. We aimed to examine it in human T2D and to elucidate its involvement in disease progression.
Methods: We evaluated pancreata obtained during pancreatectomy from Japanese subjects who had been over-weighed during adulthood and had no diabetic family history and analyzed patient’s clinical information. The diabetics in the early- and the advanced-stage that were defined by combining clinical information on disease duration, microvascular complications and insulin replacement were evaluated. The islet area was determined by measuring ChgA- positive area. We detected islet major 4 hormones-negative/ChgA-positive cells as dedifferentiated cells.
Results: There was a diversity in relative β-, α- and islet area to pancreatic area in the T2D subjects, suggesting metabolic heterogeneity associated with various capabilities of islet compensation in response to insulin resistance. We found that a decreased relative β-cell number and an increased relative α-cell number to entire ChgA-positive cell number in individual T2D islets. But there was no further increase in α-cells along disease progression despite progressive β-cell loss, and only little INS/GCG double positive cells. Instead, a strikingly elevated number of the dedifferentiated cells in T2D islets compared to control subjects and its significant increase with disease progression was observed. Importantly, there was a significant inverse correlation between increasing dedifferentiated cells and declining C-peptide index among the groups. These finding indicates that islet cells exert plasticity during diabetes progression and that β-cell dedifferentiation is a pathologic process leading β-cell failure.

Disclosure
K. Amo-Shiinoki: None. K. Tanabe: None. R. Bouchi: None. W. Nishimura: None. Y. Ogawa: Research Support; Self; Mitsubishi Tanabe Pharma Corporation. Speaker’s Bureau; Self; Daiichi Sankyo, Mitsubishi Tanabe Pharma Corporation. Y. Tanizawa: None.

Funding
Japan Society for the Promotion of Science (20390093, 25461357, 16K09752, 15K21198); Banyu International Life Science Foundation; Novo Nordisk; Japan Association for Diabetes Education and Care; Merck Sharp & Dohme Corp; Public Interest Incorporated Foundation
2039-P: Plasmin-Mediated Cleavage of Human Islet Amyloid Polypeptide (hIAPP) Protects ß-Cells from Amyloid-Induced Toxicity
Authors: ESSER NATHALIE , HOGAN MEGHAN F. , TEMPLIN ANDREW T. , CASTILLO JOSEPH J. , RALEIGH DANIEL , EDGAR JOHN S. , ZRAIKA SAKENEH , HULL REBECCA L. , KAHN STEVEN E. 
Published: June 2020

Islet amyloid deposition and reduced ß-cell mass are pathologic hallmarks of type 2 diabetes. Amyloid deposits contain the 37 amino acid hIAPP, aggregation of which is toxic to ß cells. The 20-29 amino acid region of the peptide is known to confer its amyloidogenic potential. We previously reported that plasmin, a fibrinolytic protease, cleaves hIAPP thereby inhibiting fibril formation. We now sought to determine whether hIAPP fragments arising from plasmin-mediated cleavage retain the potential to aggregate and induce cytotoxicity. The ß-cell line INS-1 was treated for 24 h with full-length hIAPP (20 µM) alone or in the presence of plasmin (0.4 µM); plasmin alone or buffer were used as controls. Exposure to hIAPP alone decreased cell viability (53±1.4% of buffer, p&lt;0.05, n=5). Addition of plasmin to hIAPP restored cell viability (90±4.3% of buffer, p=0.3 vs. buffer and p&lt;0.05 vs. hIAPP alone, n=5), while treatment with plasmin alone had no effect (102±2.9% of buffer, p=0.7, n=5). LC/MS analysis of hIAPP cleavage products showed that plasmin induced a rapid decrease in the abundance of full-length hIAPP and appearance of the hIAPP 1-11 and 12-37 fragments. Since the hIAPP 12-37 contains the amyloidogenic region, we compared the amyloidogenic and cytotoxic properties of this fragment to full-length hIAPP. In a thioflavin T assay, hIAPP 12-37 was less amyloidogenic than full-length hIAPP. As expected, treatment of INS-1 cells for 24 h with full-length hIAPP (0-60 µM) reduced cell viability in a dose-dependent manner (67±1.3%, 30±0.4% and 16±0.7% of buffer, at 20, 40 and 60 µM respectively; p&lt;0.05 vs. buffer for all, n=2), while hIAPP 12-37 was not toxic at any dose tested (90±3.2%, 90±3.3% and 108±3.5% of buffer, at 20, 40 and 60 µM respectively; n=2).
In summary, plasmin protects ß cells from hIAPP-induced toxicity by cleaving hIAPP between amino acids 11 and 12. Thus, increasing islet plasmin activity might be a strategy to limit ß-cell loss in type 2 diabetes.

Disclosure
N. Esser: None. M.F. Hogan: None. A.T. Templin: None. J.J. Castillo: None. D. Raleigh: None. J.S. Edgar: None. S. Zraika: Research Support; Self; Novartis Pharmaceuticals Corporation. R.L. Hull: None. S.E. Kahn: Advisory Panel; Self; Boehringer Ingelheim International GmbH, Eli Lilly and Company, Intarcia Therapeutics, Janssen Scientific Affairs, LLC., Merck & Co., Inc., Novo Nordisk A/S, Pfizer Inc.

Funding
U.S. Department of Veterans Affairs (I01BX001060)
2048-P: DNA Methylation Changes Reveal Distal Regulatory Regions in Islets of Intrauterine Growth Restricted Rats
Authors: LIEN YU-CHIN , LU XUEQING M. , SIMMONS REBECCA A. 
Published: June 2020

Intrauterine growth retardation (IUGR) is associated with development of type 2 diabetes in adulthood. Using a rat model of IUGR induced by bilateral uterine artery ligation, we performed RNA-Seq and HELP-TagSeq, a restriction enzyme-based genome-wide approach, to assess the association of DNA methylation changes in islets at 2 weeks of age, prior to the onset of diabetes. We identified over 2,000 transcripts differentially expressed in IUGR (q&lt;0.05 vs. control) and 512 differentially methylated regions (DMRs-&gt;3 contiguous CpGs within 500 bp) mapped to 481 genes (q &lt;0.05). 23 and 489 loci showed significantly increased and decreased DNA methylation in IUGR islets, respectively (q &lt;0.05). Integrating methylome and transcriptome datasets showed alterations in multiple genes and canonical pathways that are critical for normal islet function. DMRs were enriched with transcription factor binding motifs, such as Elk1, Etv1, Foxa1, Foxa2, Pax7, Stat3, Hnf1, and AR. These transcription factors were also identified as top upstream regulators by Ingenuity Pathway Analysis of islet transcriptomes. To determine if identified DMRs represented regulatory regions for non-proximal genes, we performed in silico analysis of 3D chromosomal interactions between conserved DMRs and interacting regions of the genome using published human pancreas and islet Hi-C datasets. Hi-C analysis identified interactions between 14 highly conserved DMRs and 35 genes (key islet genes) with expression changes (q &lt; 0.05). Changes in gene expression for many of these persisted until adulthood. In adulthood, there were far more HiC interaction genes associated with altered expression and most of these were key islet genes. Our findings have identified novel DMRs with potential distal regulatory functions, and suggest alterations of DNA methylation in key transcription factor binding motifs and genes in early life that may contribute to gene dysregulation and an abnormal islet phenotype in IUGR rats.

Disclosure
Y. Lien: None. X.M. Lu: None. R.A. Simmons: None.

Funding
National Institutes of Health (DK114054)
2053-P: Integrated Blood Flow between Endocrine and Exocrine Pancreas Is Conserved among Multiple Species
Authors: BUTTERFIELD JOHN K. , HARA MANAMI 
Published: June 2020

Pancreatic islets compose the endocrine pancreas and are considered distinct from the exocrine pancreas in terms of both function and regulation of blood flow. Indeed, enzymatically isolated islets directly respond to glucose and other secretagogues in vitro. The islet has been regarded as an enclosed micro-organ, in which blood flows uni-directionally from an afferent arteriole to an efferent venule. This blood circulation pattern has been termed as “the insulo-acinar portal system.” Historically, the endocrine and exocrine pancreas have been studied separately by different fields of investigators. Using intravital analysis of pancreas blood flow in mice, we have recently reported that islet capillaries are continuously integrated with those in the exocrine pancreas, which makes the islet circulation open, not self-contained. Furthermore, by tracking fluorescently-labeled red blood cells revealed bi-directional blood flow between the endocrine and exocrine pancreas. In the present study, in order to verify whether this integrated vascular network is conserved among different species, we carried out three-dimensional morphological analysis of pancreatic capillary networks using thick pancreatic tissue slices (600-800 µm) in ferrets, rabbits, pigs, dogs and monkeys, besides mice and humans. We have confirmed that the integrated blood flow between endocrine and exocrine pancreas is conserved among multiple species that we studied. Here we propose that the open circulation model physically links both endocrine and exocrine parts of the pancreas as a single organ through the integrated vascular network. This new paradigm may provide revived or contrasting insights into the findings of past studies, as well as a novel approach for prospective research projects.

Disclosure
J.K. Butterfield: None. M. Hara: None.

Funding
National Institutes of Health (DK117192, DK020595)
2055-P: S100A8 Suppresses ß-Cell Proliferation in Diet-Induced Obese Mice
Authors: MIYASHITA DAISUKE , SHIRAKAWA JUN , TOGASHI YU , OKUYAMA TOMOKO , KYOHARA MAYU , TERAUCHI YASUO 
Published: June 2020

S100 calcium-binding protein A8 (S100A8), a member of damage-associated molecular pattern molecules (DAMPs), reportedly contribute to the islet inflammation by mediating interaction between β-cells and macrophages (J Biol Chem., 2018). However, the role of S100A8 in the regulation of β-cell function and mass remain unclear. To clarify the role of S100A8 in β-cell functionality, we generated β-cell-specific S100A8 knockout mice (KO) by crossing S100A8-floxed mice (control) and Ins1-cre mice. In the presence of high glucose (200 mg/dL) and palmitic acid, the expression of S100A8 in KO islets significantly reduced (0.025-fold, p&lt;0.05) compared to control islets. Islets and peritoneal macrophage (Mφ) were isolated from control and KO, and cultured under the conditions of glucose concentration, presence or absence of palmitic acid, single culture or co-culture. When control Mφ co-cultured with KO islets in the presence of high glucose and palmitic acid, the expression of TNFα, IL-6, or CCL2 in Mφ was significantly reduced (0.17-fold, p&lt;0.05; 0.69-fold, p&lt;0.05; 0.22-fold, p&lt;0.05) compared to that when co-cultured with control islets. KO fed normal chow showed comparable body weight, insulin sensitivity, and glucose tolerance with control. In contrast, high-fat diet-fed KO demonstrated improved glucose tolerance, increased β-cell mass (2.65-fold, p&lt;0.05), and enhanced β-cell proliferation (1.91-fold, p&lt;0.05) compared to control. Thus, β-cell-derived S100A8 mediates the islet inflammation induced by glucolipotoxicity through the interaction with infiltrated Mφ. Furthermore, S100A8 seemed to negatively regulate β cell proliferation in diet-induced obese mice, and could be a novel therapeutic target to reverse β-cell loss in subjects with diabetes.

Disclosure
D. Miyashita: None. J. Shirakawa: None. Y. Togashi: None. T. Okuyama: None. M. Kyohara: None. Y. Terauchi: Advisory Panel; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Daiichi Sankyo, Eli Lilly Japan K.K., Novo Nordisk A/S, Sanofi. Consultant; Self; Astellas Pharma Inc. Research Support; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Daiichi Sankyo, Eli Lilly Japan K.K., Merck Sharp & Dohme Corp., Novartis Pharmaceuticals Corporation, Novo Nordisk A/S, Ono Pharmaceutical Co., Ltd., Sumitomo Dainippon Pharma Co., Ltd., Takeda Pharmaceutical Company Limited. Speaker’s Bureau; Self; Astellas Pharma Inc., AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Daiichi Sankyo, Eli Lilly Japan K.K., Kowa Company, Ltd., Medscape, Medtronic, Merck Sharp & Dohme Corp., Mitsubishi Tanabe Pharma Corporation, Novartis Pharmaceuticals Corporation, Novo Nordisk A/S, Ono Pharmaceutical Co., Ltd., Sanofi, Sanwa Kagaku Kenkyusho, Sumitomo Dainippon Pharma Co., Ltd., Taisho Pharmaceutical Co., Ltd., Takeda Pharmaceutical Company Limited, Terumo Medical Corporation.
2059-P: Gene Repression during Maturation of Pancreatic ß-Cells Mirrors Those Upregulated in Islets of Diabetic db/db Mice
Authors: NISHIMURA WATARU , TUMURKHUU MUNKHTUYA , NODA YASUKO , YASUDA KAZUKI 
Published: June 2020

Pancreatic β-cells are specialized to properly regulate glucose metabolism. Loss of individual transcription factors that are critical for endocrine differentiation embryonically causes a deep loss of cell identity and upregulation of genes normally repressed in mature β-cells. We hypothesized that the factors important for maintenance of mature β-cell homeostasis are those that are lost in the identity loss or dedifferentiation. To identify genes critical for acquisition and loss of β-cell identity, we examined islets and β-cells by comprehensive gene expression analyses. Islets isolated from 8 wk (mature) and 4 wk (immature) old C57BL/6J mice were analyzed by microarray, and FACS-sorted mature β-cells (Mafa+7AAD-) and other islet cells including Mafa negative β-cells (Mafa-7AAD-) purified from Mafa reporter mice by RNAseq. We found that the maturation process involved genome-wide downregulated gene expression. Mature islets and Mafa+ β-cells had suppression of many genes including “β-cell disallowed genes” such as Igfbp4 and Nfib, but little to noupregulation of genes critical for β-cell function such as Ins1, Slc2a2, Ucn3 and Sytl4 from 4 wk to 8 wk. In contrast, most of the suppressed genes were significantly upregulated (by RNAseq) in islets from 21 wk old diabetic BKS-db/db mice compared with BKS-db/+ (misty). Comprehensive methylation screening (MeDIP-seq) of DNA from islets of 4 and 8 wk old C57BL/6J mice specifically identified highly methylated regulatory regions in some “repressed” genes in 8 wk old islets.
In conclusion, the gain of identity during maturation phase of β-cells mirrors that of the dedifferentiation during diabetes.

Disclosure
W. Nishimura: None. M. Tumurkhuu: None. Y. Noda: None. K. Yasuda: None.

Funding
Japan Society for the Promotion of Science (JP16H01647, JP26461351, JP17K09843); International University of Health and Welfare; Japan Diabetes Foundation; Novartis Pharmaceuticals
206-LB: Survival after Islet Transplantation in Subjects with Type 1 Diabetes: 20-Year Follow-Up
Authors: RICORDI CAMILLO , LEMOS JOANA , BAIDAL DAVID , ALVAREZ ANA M. , ALEJANDRO RODOLFO 
Published: June 2020

Type 1 diabetes (T1D) is associated with premature mortality due to T1D-related acute and chronic complications, including severe hypoglycemic events (SHE), cardiovascular (CVD) and renal disease. Islet transplantation (ITx) has been shown to provide near-normal glycemic control and protection from SHEs in a select group of patients with T1D. We retrospectively evaluated the survival of ITx recipients (n= 49) followed up to 20 years. Subjects were transplanted and followed from 2000-2020 at our institution. Study cohort included 29 females (59.2%). Median age at T1D diagnosis was 13.2 (6.7 - 20.0) years while mean age and median duration of T1D at ITx was 42.8 ± 8.3 years and 29.5 (17.2 - 38.2) years, respectively. Two subjects (4.08%) died during follow-up. Duration of graft function was 4.4 (1.3 - 12.2) years. Cumulative survival post-ITx was 100%, 96% and 85%, at 10, 15 and 20 years follow-up, respectively. Results suggest that despite chronic immunosuppression, near-normal metabolic control achieved following ITx can reduce the increased mortality risk associated with T1D. Possible factors accounting for these results include lower cumulative hyperglycemic exposure and prevention of SHE. Subjects selected for ITx represent a highly vulnerable group at risk of recurrent SHE and death. ITx may prevent mortality by preventing SHE and reducing CVD risk factors in selected patients with T1D.

Disclosure
C. Ricordi: None. J. Lemos: None. D. Baidal: None. A.M. Alvarez: None. R. Alejandro: None.

Funding
Diabetes Research Institute Foundation; State of Florida; JDRF; The Leona M. and Harry B. Helmsley Charitable Trust; University of Miami Clinical and Translational Science Institute
2063-P: Quantitative Analysis of Human and Mouse Islet Tissue Structure
Authors: CREASEY OLIVIA A. , SNEDDON JULIE B. , GARTNER ZEV J. 
Published: June 2020

The pancreatic islet is a complex tissue consisting of multiple endocrine cell types, capillaries, and a peri-islet basement membrane. The 3D organization of cells, blood vessels, and basement membrane (BM), enhances islet function by (1) supporting beta cell electrochemical coupling and synchronization through gap junctions between adjacent cells and (2) providing access to nutrients and signals for beta cell survival and function through contact with capillaries and BM. Though a quantitative understanding of islet structure is lacking, there is strong evidence linking islet structural changes to diabetes progression. Studies of these changes in islet structure will enhance understanding of diabetes-related losses in islet function and lead to the development of new therapeutics for diabetic and prediabetic patients. Here, we have quantified healthy adult islet tissue structure through a single-cell analysis of the cell-cell and cell-BM interactions at individual endocrine cell plasma membranes. We have used this single-cell data to identify endocrine cell subtypes, as defined by cell morphology and structural niche. We have also identified spatially-defined clusters of beta cells through a graph analysis of cell-cell connectivity. We report a baseline quantification of structure for healthy adult human and mouse islets. These data both provide an answer to the ongoing debate regarding the differences in structure between human and mouse islets and set the stage for future quantification of islet structure in diabetes.

Disclosure
O.A. Creasey: None. J.B. Sneddon: Advisory Panel; Self; Encellin. Advisory Panel; Spouse/Partner; Encellin. Z.J. Gartner: None.

Funding
National Science Foundation (1650113, DBI-1548297); National Institutes of Health (P30DK063720); Chan-Zuckerberg Biohub; Bakar Foundation
2064-P: Pharmacological Modulation of Prostaglandin E2 Receptor Activity Enhances ß-Cell Mass and Maintains ß-Cell Identity in a Mouse Model of Type 2 Diabetes
Authors: CHRISTENSEN ASHLEY A. , ANDREI SPENCER R. , DUNN JENNIFER C. , RICCIARDI VALERIE F. , PACE WILLIAM A. , BREYER RICHARD M. , GANNON MAUREEN 
Published: June 2020

Type 2 diabetes (T2D) is a chronic condition characterized by hyperglycemia and inflammation. This condition arises in response to a failure to increase β-cell mass in the face of insulin resistance. Prostaglandin E2 (PGE2), which signals through four receptors (EP1-4), is a mediator of inflammation that has been shown to be upregulated in diabetes. Previous data from our lab has shown that EP3 receptor blockade promotes β-cell proliferation and survival in isolated mouse and human islets ex vivo. In the current study, six week-old db/db mice were treated with the EP3 antagonist DG-041 (20 mg/kg) daily for two weeks. Pancreata were excised and analyzed using immunohistochemistry. We found that treatment with DG-041 leads to improved β-cell mass (2.8 ± 1.5 mg) compared to mice treated with vehicle alone (1.0 ± 0.7 mg). Additionally, we also observed increased β-cell proliferation in DG-041-treated mice (2.2 ± 0.6% Ki67+/Ins+ β-cells) compared to vehicle-treated mice (1.6 ± 0.3%). Further analysis demonstrated that the β- to α-cell ratio was altered in mice treated with DG-041 (2.13:1) compared to vehicle-treated mice (1.78:1). We also immunolabeled for MafA and Nkx6.1, as loss of these transcription factors has been correlated with β-cell dysfunction and diabetes progression in db/db mice and humans. DG-041-treated mice had a higher percentage of MafA positive β-cells (50.3 ± 3.8%) compared to vehicle-treated mice (40.7 ± 3.8%) while there were similar numbers of Nkx6.1 positive β-cells in DG-041-treated and vehicle-treated groups (81.3 ± 4.7% and 81 ± 5.1%, respectively). The current results provide evidence that EP3 receptor blockade promotes β-cell mass expansion and proliferation while preserving homeostatic endocrine islet composition.

Disclosure
A.A. Christensen: None. S.R. Andrei: None. J.C. Dunn: None. V.F. Ricciardi: None. W.A. Pace: None. R.M. Breyer: None. M. Gannon: None.

Funding
U.S. Department of Veterans Affairs (1I01BX003744-01); National Institute of Diabetes and Digestive and Kidney Diseases (1R01DK120626-01A1)
2070-P: KCNJ11 (Kir6.2) Gain-of-Function Mutation in Zebrafish Leads to Transient Neonatal Diabetes
Authors: IKLE JENNIFER , SINGAREDDY SOMA S. , TRYON ROBERT C. , YORK NATHANIEL , YIN LINLIN , CHEN WENBIAO , NICHOLS COLIN 
Published: June 2020

The majority of neonatal diabetes (NDM), defined by early onset of hyperglycemia due to impaired β-cell function, is caused by gain-of-function (GOF) mutations in the ATP-sensitive potassium (KATP) channel genes (ABCC8 encoding SUR1 and KCNJ11 encoding Kir6.2). These GOF mutations lead to increased KATP channel activity, decreased β-cell excitability, and impaired insulin secretion. A zebrafish model of NDM can provide a high throughput platform for understanding mechanisms of NDM and testing potential therapeutic approaches. To create such a model, we used CRISPR mutagenesis to introduce the most common human Kir6.2 GOF mutation (R201H) into the equivalent zebrafish locus. Patch-clamp analysis demonstrates decreased ATP sensitivity in β-cells isolated from mutant fish (K1/2 for ATP inhibition = 17.21 ±1.66 mM in WT, 40.38 ± 7.6 mM in heterozygous R201H). Increasing [glucose] causes a robust increase of [Ca]i in WT islets expressing a GCaMP6s fluorescent reporter, but there is no glucose-dependent increase in R201H islets. R201H fish have smaller overall body size, indicative of failure to thrive, and β-cell density is reduced ∼50% in R201H compared to WT. Whole body glucose was measured from larval zebrafish using a fluorometric assay. Starting at 4 weeks of age, blood glucose was directly measured by glucometer from the transected cardiac cavity. While R201H animals are markedly hyperglycemic (BG &gt; 250 mg/dl) at 4 weeks, blood sugar normalizes (BG &lt;120 mg/dl) by ∼12 weeks of age.
In conclusion, R201H mutants demonstrate the expected KATP GOF, loss of glucose-dependence of [Ca]i, and marked hyperglycemia early in life, proving a viable model of the molecular and cellular consequences of NDM. Intriguingly, early hyperglycemia is followed by normalization of blood sugar in older fish. This resolution of hyperglycemia is an unexpected finding, and may provide further insight into physiologic differences between transient and permanent NDM.

Disclosure
J. Ikle: None. S.S. Singareddy: None. R.C. Tryon: None. N. York: None. L. Yin: None. W. Chen: None. C. Nichols: None.

Funding
National Institutes of Health (DK109407); Pediatric Endocrine Society; Endocrine Fellows Foundation