bluuebunny/crossref_metadata_2025 huggingface dataset:
167-OR: Significant Differences in DKA Outcomes across Hospitals Despite Same Guidelines Highlights the Need for Better Implementation Strategies—Results from DEKODE Initiative
Authors: KEMPEGOWDA PUNITH , RENGARAJAN LAKSHMI , NARENDRAN PARTH , TEAM DEKODE
Published: June 2023

Aim: To measure differences in DKA care and outcomes between hospitals having same guidelines.

Method: The data was gathered as part of the DEKODE (Digital Evaluation of Ketosis and Other Diabetes-related Emergencies) initiative from October 2021 to September 2022 in six hospitals (anonymised as A to F) in the UK which has guidelines based on Joint British Diabetes Societies-Inpatient (JBDS-IP) recommendations. We collected data on adherence to Fixed Rate Intravenous Insulin Infusion (FRIII), fluids administration, glucose monitoring, and ketones monitoring. Pseudonymised data on dates and times of admission, discharge, DKA diagnosis and resolution was collected. Independent-Samples Kruskal-Wallis test was performed to assess differences in various parameters of DKA care and outcomes.

Results: A total of 442 DKA episodes were analysed. There were differences between hospitals in fluids administration (median: A-92.1%, B-101.3%, C-89.7%, D-76.0%, E-98.3%, F-115.5%; p<0.001), glucose monitoring (median: A-103.1%, B-86.1%, C-88.9%, D-106.4%, E-99.2%, F-95.7%; p<0.001), and ketone monitoring (median: A-71.5%, B-85.1%, C-70.0%, D-59.3%, E-65.0%, F-85.7%; p<0.001). There was no significant difference in FRIII (median: A- 99.5%, B- 100.0%, C- 100.0%, D- 100.0%, E- 93.9%, F- 99.8%; p=0.064). We found inter-hospital differences in DKA duration (median in hours; A-13.3, B-13.4, C-18.5, D-15.1, E-17.1, F-16.3; p=0.002), and length of stay (median in days; A-2.1, B-2.5, C-3.5, D-3.6, E-2.5, F-3.0; p<0.001).

Conclusion: Despite similar guidelines, significant variations in DKA outcomes exist between hospitals. Variations in various components of DKA highlight there may be differences in guidelines implementation. A centralised data collection system can identify and share best practices between centres, which may help minimise inter-hospital variations and facilitate uniform patient care.

Disclosure

P.Kempegowda: None. L.Rengarajan: None. P.Narendran: Advisory Panel; Omnipod, Speaker's Bureau; Abbott Diabetes, Lilly Diabetes. Dekode team: n/a.
1674-P: Increased Glucose Uptake in Brown Fat Promotes Energy Expenditure
Authors: REZAYAT FARID , RESNICK JULIE A. , FARAH ISABELLA M. , SKOROBOGATKO YULIYA , SALTIEL ALAN
Published: June 2023

Brown and beige fat dissipate energy as heat in response to β3-adrenergic receptor (β3AR) stimulation. Strategies to facilitate this response may be employed to promote weight loss and improve health in patients with metabolic disease. Previously, we discovered that GTPase RalA and its GAP complex RalGAP regulate exocytosis of glucose transporter GLUT4. We demonstrated in vivo, that adipose-tissue specific knockout of RalGAP subunit RalGAPB activates RalA and increases glucose uptake 7 times in brown fat (BAT), leading to improved glucose handling on high fat diet (HFD). Here we seek to test the effect of increased glucose uptake in BAT on energy expenditure (EE), using mice with BAT-specific knockout of RalGAPB (the KO mice).

After 8 weeks on 45% HFD, the KO mice and control littermates (Ctr) were injected with β3AR agonist CL-316,243 (CL) or PBS for 8 days. Mice assigned to CL were placed in metabolic cages. Respiratory quotient was increased in the KO mice, indicating increased glucose oxidation (likely by BAT, due to increased glucose uptake). EE at room temperature was elevated in the KO mice. This was compensated by increased food uptake, explaining similar body weights between the KO and Ctr mice. CL injections, as expected, induced spikes in EE. Acute response to CL (arbitrarily defined as EE during 2 hours after CL injection) was consistent between daily CL injections in Ctr mice, and was increased twice in the KO mice compared to Ctr. In Ctr mice, 1st CL injection increased average day and night EE; this response gradually declined with consecutive CL injections. In the KO mice, 1st CL injection elicited similar to Ctr mice increase in average day and night EE; and the response to consecutive CL injections was preserved. As anticipated, CL reduced adiposity in Ctr mice, which was further augmented in the KO mice, consistent with finding on EE. We will further test the role of increased glucose uptake by BAT in EE of the KO mice, and will determine the mechanism of sustained CL responsiveness in the KO mice.

Disclosure

F.Rezayat: None. J.A.Resnick: None. I.M.Farah: None. Y.Skorobogatko: None. A.Saltiel: Board Member; Elgia Therapeutics.

Funding

National Institutes of Health (P30DK063491)
1680-P: Methyl Dihydrojasmonate (MDJ) Induces Hallmarks of Polycystic Ovary Syndrome (PCOS) and Related Mechanisms in Female Mice
Authors: CAI MEILI , DILIMULATI DILIQINGNA , ZHANG YUQIN , SHAO XIAOWEN , QU SHEN , ZHANG MANNA
Published: June 2023

More than half of polycystic ovary syndrome (PCOS) are overweight or obese. Environmental endocrine-disrupting chemicals (EDCs) are one of the important pathogenic factors in PCOS women. Methyl dihydrojasmonate (MDJ) is a food flavor additive, which can enter the body through several paths. However, the impact of MDJ on obese PCOS patients is still unknown. Hence, the study aims to determine whether MDJ may induce hallmarks of PCOS as new EDCs. The blood samples (33 obese PCOS patients and 30 controls) were collected for metabonomic sequencing. Sequencing results that serum MDJ level was significantly increased in obese PCOS patients, and was closely associated with the clinical phenotype of PCOS. C57BL/6J female mice fed high-fat diets were randomly divided into four groups. The PCOS model was established by subcutaneous injection of dehydroepiandrosterone for 21 days. Different concentrations of MDJ group were gavage of MDJ (60, and 120 mg/kg/d), and the control group was gavage of corn oil, once daily from pregnancy to offspring 16 weeks old. After 16 weeks, different concentrations of MDJ treatment resulted in an irregular estrus cycle and disturbed ovarian development in female mice. Serum TT and insulin resistance levels were increased in the MDJ group. At the cellular level, different concentrations of MDJ (50, and 100 μg/L) intervention mouse-primary-granulosa-cells (mpGCs) and measured supernatant TT levels after 48h. In the mouse ovarian tissue and mpGCs, we found that the expression of key genes for steroid synthesis (Star, Cyp17a1, Hsd3b1, Lhcgr) was increased significantly, while the expression of Cyp19a1 decreased after different concentrations of MDJ treatments. In preliminary experiments, we found that long-term exposure to MDJ during pregnancy and growth can induce PCOS phenotype in C57BL/6J female mice. Ongoing studies will determine how MDJ induces the hallmarks of PCOS and related mechanisms, which may help reveal the pathogenesis of PCOS.

Disclosure

M.Cai: None. D.Dilimulati: None. Y.Zhang: None. X.Shao: None. S.Qu: None. M.Zhang: None.

Funding

National Key R&D Program of China (2018YFC1314100); National Natural Science Foundation of China (81601269)
1683-P: High-Fat Diet Downregulates CREG1 in the Liver via DNA Methylation
Authors: QI YANMEI , LIU JIE , CHAO JOSHUA C. , RAHIMI SAUM A. , LEE LEONARD Y. , LI SHAOHUA
Published: June 2023

CREG1 is an endosomal-lysosomal protein which is highly expressed in the liver. Hepatocyte-specific deletion of Creg1 in mice causes insulin resistance and elevated glycemia. To test if CREG1 is nutritionally regulated, we fed mice for 10 weeks with a high-fat diet (HFD) which progressively downregulated CREG1 in the liver at both protein and mRNA levels. The CREG1 expression was restored after switch back to a standard chow diet for two weeks. The diet-induced CREG1 changes negatively correlated with blood glucose levels. Sequence analysis revealed enrichment of CpG islands in exon 1 of both human and mouse CREG1 genes. To test if methylation of these CpG islands contributes to HFD-induced CREG1 reduction, we fed mice with a HFD for 10 weeks and treated them with the DNA methyltransferase inhibitor 5-aza-deoxycytidine, which reversed HFD-induced CREG1 downregulation in the liver. At the cellular level, overload of cultured human hepatocytes with fatty acids reduced CREG1 expression, and this was reversed by inhibiting DNA methylation. Furthermore, removal of all CpG islands in the first exon with sense mutations abolished lipid overload-induced CREG1 downregulation. These results suggest that HFD downregulates CREG1 via DNA methylation of the CpG islands in the first exon. It would be interesting to test if CREG1 reduction mediates HFD-induced insulin resistance.

Disclosure

Y.Qi: None. J.Liu: None. J.C.Chao: None. S.A.Rahimi: None. L.Y.Lee: Speaker's Bureau; Abbott. S.Li: None.

Funding

Rutgers Biomedical and Health Sciences
1686-P: ER Stress Aggravates Diaphragmatic Weakness through Activating PERK/JNK Signaling in Obesity Hypoventilation Syndrome
Authors: XIANG XIAOXIN , ZHU YANHUA , PAN XUYA , XIN WEI , TANG WEIJIAN , HE XUEMIN , SHI GUOJUN , CHEN YANMING
Published: June 2023

Obesity hypoventilation syndrome (OHS) is associated with reduced quality of life and increased risk of death. Diaphragmatic dysfunction has been implicated in the pathogenesis of OHS. We found that significant diaphragmatic weakness and lipid accumulation in people with obesity as well as mouse models of obesity, which was associated with activated endoplasmic reticulum (ER) stress indicated by increased PERK signaling and activation of JNK pathway. In cultured myotubes, inhibition of PERK and JNK signaling abrogated the lipids deposition and ameliorated insulin resistance, and inhibition of JNK signaling reversed the impaired elasticity of myotubes induced by lipotoxicity. Collectively, our data suggest that activation of PERK/JNK signaling is an important pathophysiological factor contributing to diaphragmatic contractile dysfunction in OHS.

Disclosure

X.Xiang: None. Y.Zhu: None. X.Pan: None. W.Xin: None. W.Tang: None. X.He: None. G.Shi: None. Y.Chen: None.

Funding

National Key R&D Program of China (2017YFA0105803); National Natural Science Foundation of China (82270886, 82070811); 5010 Clinical Research Projects of Sun Yat-sen University (2015015); Science and Technology Plan Project of Guangzhou City (202007040003, 202201020497); Key Area R&D Program of Guangdong Province (2019B020227003); Science and Technology Research Development Program of Guangzhou City (202007040003, 202201020497)
1692-P: Designing and Testing a Novel Weight Navigation Program to Improve Obesity Treatment in Primary Care Settings
Authors: GRIAUZDE DINA H. , TURNER CASSIE D. , HENDERSON JAMES , OTHMAN AMAL , OSHMAN LAUREN , GABISON JONATHAN , WALFORD ERIC , ARIZACA-DILEO PATRICIA K. , BECKIUS DEENA I. , KRAFTSON ANDREW T.
Published: June 2023

Background: We developed and tested a novel Weight Navigation Program (WNP). The WNP aims to (1) integrate American Board of Obesity Medicine Diplomates into primary care teams, (2) deliver preference-sensitive weight management treatment, and (3) optimize patients’ achievement of ≥5% weight loss through remote weight monitoring with proactive outreach to support patients with <5% weight loss.

Methods: This is a quality improvement program conducted at an academic primary care site from October 2020 to September 2021. WNP inclusion criteria are BMI ≥30 and ≥1 weight-related condition. Primary outcomes were measures of feasibility, including rates of referral to and engagement in the WNP. Secondary outcomes were mean weight loss and percentage of patients achieving ≥5% weight loss. We compared rates of referral to weight management treatment programs (i.e., nutrition counseling, meal replacement (MR), bariatric surgery) and prescribing of weight management medications (WMMs) among WNP-eligible patients at the pilot site and at a nearby clinic (control). Rates are also reported for patients with a completed WNP visit.

Results: Of 1,533 eligible patients, 238 (16%) were referred to the WNP and 135 (9%) completed a WNP visit. Mean percent weight change at 12-months for WNP patients was 5% and 39% achieved ≥5% weight loss. WNP-eligible patients at the WNP site (n=1,533) were referred to WMTs and prescribed WMMs at similar rates to WNP-eligible patients at the control site (n=2,913) (nutrition counseling 4.8% v. 6.8%, MR 1.0% v. 0.6%, WMM 2.0% v. 3.2%, bariatric surgery 1.2% vs. 1.8%). Patients with a completed WNP visit (n=135) received WMTs at substantially higher rates than the pilot and control sites (nutrition counseling 26.7%, MR 13.3%, WMM 11.9%, bariatric surgery 16.3%).

Discussion: A WNP is feasible and may support achievement of ≥5% weight loss. Additional work is needed to compare the efficacy of WNP vs usual care for weight loss.

Disclosure

D.H.Griauzde: None. A.T.Kraftson: None. C.D.Turner: None. J.Henderson: None. A.Othman: None. L.Oshman: Stock/Shareholder; Abbott, AbbVie Inc., Merck & Co., Inc., Procter & Gamble, Johnson & Johnson, Eli Lilly and Company. J.Gabison: None. E.Walford: None. P.K.Arizaca-dileo: None. D.I.Beckius: None.

Funding

University of Michigan Elizabeth Weiser Caswell Diabetes Institute; Michigan Center for Diabetes and Translational Research (P30DK092926-09 to D.H.G.); National Institute of Diabetes and Digestive and Kidney Diseases (K23DK123416-01A1 to D.H.G.)
1698-P: The Effect of Ectopic Fat on Brain Structure and Cognitive Function—A Meta-analysis from Observational Studies of 1,003,593 Individuals
Authors: SONG ZHIHUI , LIU JING , ZHANG ZHAO , ZHOU JIANBO
Published: June 2023

Abstract Purpose: To investigate the effects of ectopic fat on brain structure and cognitive function.

Methods: Data extraction and meta-analysis of eligible clinical studies were performed.

Results: The results showed ectopic fat was associated with the decreased total brain volume, posterior cingulate cortex volume, semioval center volume, sensorimotor cortex volume, and the increased lateral ventricle volume. Subcutaneous fat significantly was associated with the reduced risk of cerebral white matter hyperintensities (OR = 0.86, 95% CI: 0.74 to 1.00). Ectopic fat was associated with the decreased cognitive function. Visceral fat was significantly associated with poor cognitive outcomes (OR=1.42, 95% CI: 1.11 to 1.81).

Conclusion: Visceral ectopic fat was associated with the increased risk of brain structural changes and cognitive impairment. A new strategy identifying patients at risk of developing cognitive decline may be implemented timely and personalized treatment.

Fig.1 The relationship between ectopic fat and cognitive scores (WMD)

Disclosure

Z.Song: None. J.Liu: None. Z.Zhang: None. J.Zhou: None.
1709-P: Perceptions of Treatment Outcomes in People with Obesity and T2D—A Qualitative Study
Authors: LING POON JIAT , O'HARA LOUISE , KENDAL HELEN , SULLY KATE , GUY MARGARET , BRADLEY HELENA , TOLLEY CHLOE , MASON BRAD
Published: June 2023

Background: Treatments for obesity and T2D often combine lifestyle changes (diet, physical activity) and medication. Weight reduction is an expected outcome of obesity and some T2D treatments. Individuals’ perspectives on obesity treatments, attitudes towards reduced food intake via appetite changes, and treatment-related gastrointestinal adverse events (GI AEs) are not well characterized. The current study assessed individuals’ perceptions of obesity/T2D treatments that impact appetite, eating behaviors, and weight, and concerns about GI AEs.

Methods: This cross-sectional study involved semi-structured interviews with 45 US adults (obesity, n=15; overweight, n=10; T2D, n=20). Two creative tasks explored participants’ perceptions of obesity/T2D treatment outcomes: 1) participants discussed perspectives on hypothetical obesity/T2D treatments that reduced appetite, hunger, and cravings; 2) participants indicated their choice from two hypothetical obesity/T2D treatments, which varied by degree of GI AEs, appetite changes, and weight reduction. Interviews were audio recorded and transcribed for analysis.

Results: Most participants asked (28/35; 80%) perceived the hypothetical scenarios as a positive outcome of obesity/T2D treatment. Most (30/35; 86%) considered appetite reduction to be an important treatment benefit. Many also perceived fewer cravings (13/29; 45%) and lesser desire to eat (12/29; 41%) to be positive treatment outcomes. Participants associated treatment-related appetite changes with improvements in diet (10/33; 30%), emotional well-being (9/33; 27%), and daily activities (8/33; 24%). In the choice task, participants perceived appetite and weight reduction as positive treatment outcomes, irrespective of degree of GI AEs.

Conclusions: Findings demonstrate that participants value appetite changes and/or weight reduction as treatment priorities, and are willing to accept potential GI AEs for these treatment outcomes.

Disclosure

J.Poon: Employee; Eli Lilly and Company, Stock/Shareholder; Eli Lilly and Company. L.O'hara: Other Relationship; Lilly. H.Kendal: Other Relationship; Eli Lilly and Company. K.Sully: None. M.Guy: Employee; Adelphi Values, Other Relationship; Eli Lilly and Company. H.Bradley: Other Relationship; Eli Lilly and Company. C.Tolley: None. B.Mason: None.
171-LB: The Online Structured DSMES Program Improved Glycemic Control in Young Adults but Not in Children and Adolescence with T1DM
Authors: AN LINGWANG , JI LINONG
Published: June 2023

Background: The COVID-19 pandemic has forced rapid reconsideration of the way in which health care is delivered in patients with T1DM. We explored the effect of an online structured DSMES program on glycemic control and self-management behavior in patients with T1DM.

Methods: The intervention included 2 modules: (1) series of online DSMES sessions based video courses and personalized discussion on diabetes management; (2) continuous interactions and support based Wechat platform through text, audio or video.

Results: A total of 36 subjects were enrolled into the final analysis, of them, 26 (72.2%) were young adults above 18 years and 10 (27.8%) were children and adolescence below 18. There were significant changes in HbA1c, TIR and hypoglycemic event in young adults; however, no significant difference were found in children and adolescence. There were significant behavior change measured using self-management scale of T1DM for Chinese adults (SMOD-CA) in participants aged ≥18, mainly in the domains of daily performance, coping with disease-related problems and goals of disease management; however, no significant behavior change were found in adolescence with T1DM (DBRS). (Table 1)

Conclusions: The online structured DSMES program improved glycemic control, self-management behavior and reduced hypoglycemic event in young adults but not in children and adolescence with T1DM.

Disclosure

L. An: None. L. Ji: Other Relationship; Eli Lilly and Company, Novo Nordisk, Merck & Co., Inc., Bayer Inc., Sanofi-Aventis U. S., Roche Pharmaceuticals, MSD Life Science Foundation, AstraZeneca, Boehringer Ingelheim Inc., Abbott, Metronics.
172-OR: Normative CGM Glucose Levels throughout Gestation in Patients with Uncomplicated Pregnancies
Authors: CARLSON ANDERS L. , BECK ROY , LI ZOEY , NORTON ELIZABETH , BERGENSTAL RICHARD M. , JOHNSON MARY L. , DUNNIGAN SEAN , BANFIELD MATTHEW , KRUMWIEDE KATIE J. , SIBAYAN JUDY , CALHOUN PETER , DURNWALD CELESTE
Published: June 2023

Glycemic patterns throughout pregnancy are not well described, particularly early pregnancy. CGM used throughout the gestational period in uncomplicated pregnancies may help describe glycemic patterns in more detail. Blinded CGM data were collected throughout pregnancy from 760 pregnant patients ≥18 years old, with HbA1c <6.5%, no known diabetes, and gestational age <17 weeks. CGM data from uncomplicated pregnancies (pregnancy without gestational diabetes, large for gestational age birth, or hypertensive disorder of pregnancy) established the normative data set. Uncomplicated pregnancies (n=427, mean±SD age 32±4 years, 73% White non-Hispanic, mean HbA1c 5.1±0.3%) showed mean glucose during the entire gestational period was 99±7 mg/dL. Trimester specific mean glucose was: 103±7, 98±7 and 98±8 mg/dL for 1st, 2nd, 3rd trimesters. Figure 1 shows mean glucose by hour/trimester. Median (quartiles) percent time in range (TIR) 63-120 mg/dL was 86% (82-89%) for gestational period, and 84% (79-89%), 87% (82-90%), and 85% (80-90%) for 1st, 2nd, 3rd trimesters. Figure 2 shows TIR 63-120 mg/dL by 4-week periods. In uncomplicated pregnancies, mean glucose and TIR 63-120 mg/dL remained consistent throughout the gestational period. These normative CGM data will help set pregnancy-specific glycemic targets and will be important to compare to those 333 women in this study with complicated pregnancies.

Disclosure

A.L.Carlson: Advisory Panel; MannKind Corporation, Novo Nordisk, Research Support; Abbott Diabetes, Dexcom, Inc., Eli Lilly and Company, Medtronic, Novo Nordisk, Insulet Corporation, UnitedHealth Group, Sanofi. J.Sibayan: None. P.Calhoun: None. C.Durnwald: None. R.Beck: Consultant; Eli Lilly and Company, Novo Nordisk, Diasome, Insulet Corporation, Research Support; Tandem Diabetes Care, Inc., Beta Bionics, Inc., Dexcom, Inc., Bigfoot Biomedical, Inc., Medtronic, Ascensia Diabetes Care, Roche Diabetes Care, Eli Lilly and Company, Novo Nordisk. Z.Li: None. E.Norton: None. R.M.Bergenstal: Advisory Panel; Abbott Diabetes, Eli Lilly and Company, Medtronic, Novo Nordisk, Roche Diabetes Care, Zealand Pharma A/S, Consultant; Ascensia Diabetes Care, Bigfoot Biomedical, Inc., CeQur SA, Dexcom, Inc., Hygieia, Onduo LLC, Sanofi, Vertex Pharmaceuticals Incorporated, Research Support; Abbott Diabetes, Dexcom, Inc., Eli Lilly and Company, Insulet Corporation, Medtronic, Novo Nordisk, Sanofi, UnitedHealth Group. M.L.Johnson: Research Support; Abbott, Lilly, Insulet Corporation, NIH - National Institutes of Health, Patient-Centered Outcomes Research Institute, Novo Nordisk, Tandem Diabetes Care, Inc., Medtronic, Hemsley Charitable Trust, Jaeb Center for Health Research. S.Dunnigan: None. M.Banfield: None. K.J.Krumwiede: None.

Funding

The Leona M. and Harry B. Helmsley Charitable Trust; United Health Group
1734-P: Polyhormonal Cells of the Pancreatic Islets in Congenital Hyperinsulinism
Authors: KRIVOVA YULIYA , PROSHCHINA ALEXANDRA E. , GUBAEVA DILIARA , MELIKYAN MARIA , OTLYGA DMITRY
Published: June 2023

One of the possible causes of insulin deficiency in diabetes is dedifferentiation of β-cells into immature phenotypes with decreased insulin content or into the polyhormonal cells containing both insulin and glucagon. Polyhormonal cells have been detected in the pancreas in diabetic animal models as well as in humans with type 2 diabetes and longstanding type 1 diabetes, suggesting this phenomenon is a consequence of hyperglycemia. However, there is no information about the presence of polyhormonal cells in opposite metabolic conditions such as hypoglycemia in infants with congenital hyperinsulinism (CHI). We examined pancreatic biopsies from 6 infants with diffuse CHI and 5 infants with focal CHI using double immunofluorescence with antibodies to insulin and glucagon. In focal CHI, we found a significant proportion of α-cells containing glucagon and insulin within the focal lesion and in the rest of the tissue. Similarly, in diffuse CHI, we found the majority of α-cells contained glucagon and insulin in all pancreatic islets. The proportion of insulin and glucagon varied in the polyhormonal cells - from cells with equal expression of these hormones to cells with the prevalence of insulin or glucagon. In one diffuse case and in two focal lesions, we observed polyhormonal cells with significantly decreased glucagon expression and normal insulin expression. Outside the latter focal lesions, cells had normal level of glucagon expression. Our results indicate that polyhormonal cells are not exclusive for diabetes and hyperglycemia. We found polyhormonal cells in the pancreas of infants with CHI under hypoglycemic conditions. We suggest that this indicates high degree of the plasticity of the pancreatic cells. The role of plasticity in infants with CHI is yet to be established.

Disclosure

Y.Krivova: None. A.E.Proshchina: None. D.Gubaeva: None. M.Melikyan: None. D.Otlyga: None.
1737-P: Novel Interaction between Nkx6.1 and Pdx1 Is Needed for Proper Beta-Cell Function
Authors: TESSEM JEFFERY S. , LITTLEFIELD CONNOR C. , HILL JONATHON T.
Published: June 2023

The beta cell transcription factor Nkx6.1 is critical in pancreatic progenitor cells and mature beta cells. The pathways regulated by Nkx6.1 that results in these phenotypes are still being defined. We sought to define the transcriptional factors that interact with Nkx6.1 and may be harnessed to expand functional beta cell mass. INS-1 832/13 beta cells were transduced with AdCMV-Nkx6.1-BioID, AdCMV-GFP-BioID or left untreated. Biotinylated proteins were isolated and the Nkx6.1 interactome was defined using liquid chromatography-tandem mass spectrometry. We defined 176 biotinylated proteins in cells transduced with AdCMV-Nkx6.1-BioID that were not observed with AdCMV-GFP-BioID or naturally biotinylated proteins from untreated lysates. These potential Nkx6.1 interacting proteins are enriched in nucleotide binding, ribosomal proteins, and transcription factors. Among the enriched transcription factors, we validated that Pdx1 is biotinylated in response to transduction with AdCMV-Nkx6.1 using biotin-targeted immunoprecipitation and western blot. To examine if Pdx1 is likely to interact with Nkx6.1 on the genome, we analyzed the frequency of proximal binding sites for Nkx6.1 and Pdx1, and demonstrated that Pdx1 and Nkx6.1 binding sites in close proximity were statistically overrepresented in the genome. Given the role of Pdx1 on functional beta cell mass, we further characterized the interaction of endogenous Nkx6.1 and Pdx1 by co-immunoprecipitation (Co-IP). Our data demonstrates significant Pdx1 binding by Nkx6.1 Co-IP and significant Nkx6.1 binding by Pdx1 Co-IP, as compared to Co-IP with the IgG control. Finally, we demonstrate coregulation of Unc3 expression by Nkx6.1 and Pdx1 and demonstrate that CRISPR mediated deletion of either Nkx6.1 or Pdx1 is sufficient to impair INS-1 832/13 mediated expression of Unc3. These data define potential Nkx6.1 binding partners in INS-1 832/13 cells, as well as novel interaction between Nkx6.1 and Pdx1 in the regulation of Unc3.

Disclosure

J.S.Tessem: None. C.C.Littlefield: None. J.T.Hill: None.
1738-P: Instrument-Free Single-Cell Resolution of Transcriptome in Mouse Pancreatic Islet Cells
Authors: DIMITROVA DILYANA G. , LIBOZ ALEXANDRINE , LIPIN STANISLAV , BEAUPERE CARINE , ROBLOT NATACHA , KOMATSU JUN , GUILLEMAIN GHISLAINE , BLONDEAU BERTRAND
Published: June 2023

Type 1 diabetes is characterized by an almost complete depletion of insulin-producing beta cells. Thus, regeneration of beta cells through beta-cell neogenesis represents a major therapeutic strategy to cure the disease. We previously reported a mouse model of severe insulin resistance that leads to high insulin secretion and massive beta-cell neogenesis. To understand the origins of the newly formed beta cells and the genic programs involved in high insulin secretion, we aimed at defining the pancreatic islet cells transcriptome at high resolution cell by cell. Here, we tested the compatibility of the novel instrument-free 3’ single-cell RNA-sequencing benchtop kit Asteria™, recently released by Scipio bioscience (Paris, France), on pancreatic islet cells isolated from adult mice, which underwent cell dissociation by trypsin treatment. In the Asteria™ procedure, differently from the microfluidic-based single-cell one, coupling of solid polymer-barcoded beads and cells occurs in homogenous phase in a reversible hydrogel named RevGel™. Such conditions are claimed by the vendor to be causing less mechanical stress to cells for an expected more preserved transcriptome. Successive steps were classic molecular biology and bioinformatic analysis using Scipio bioscience’s data analysis cloud-based software Cytonaut™. We profiled the transcriptome of 938 single cells from healthy mice and identified a total of 12 cell subtypes. SingleR annotation based on reference data revealed all the major cell types commonly described in the literature, including a well-represented beta cell population and some rare cell types such as ductal and stellate cells. We demonstrate 3’ single-cell RNA-sequencing using Scipio bioscience’s kit Asteria™ as an effective strategy to dissect the heterogeneity and the complexity of mouse pancreatic islets and identify the gene expression signatures of each cell.

Disclosure

D.G.Dimitrova: None. A.Liboz: None. S.Lipin: None. C.Beaupere: None. N.Roblot: None. J.Komatsu: None. G.Guillemain: None. B.Blondeau: None.
1742-P: Loss of MAFB Compromises a-Cell Identity and Glucagon Secretion in Adult Human Islets
Authors: COATE KATIE C. , TONG XIN , LIU JIN-HUA , JENKINS REGINA , ARAMANDLA RADHIKA , DEY NANDITA , KIM SEUNG , BRISSOVA MARCELA , POWERS ALVIN C. , STEIN ROLAND
Published: June 2023

Islet-enriched transcription factors (TFs) are critical regulators of α and β cell development and function. One such TF, MAFB, exhibits a distinct expression pattern between species in that it is restricted to α cells postnatally in rodents, but produced in both developing and adult human α and β cells. While MAFB is essential for insulin production and secretion in human embryonic stem cell models, the impact of MAFB loss in mature α and β cells is unknown. Importantly, both T1D and T2D are associated with dramatic loss of islet MAFB expression. To test the hypothesis that MAFB is a critical regulator in adult human islets, dispersed islet cells were infected with lentiviruses expressing control or MAFB knockdown (MAFBKD) shRNAs, and reaggregated for 6 days to form pseudoislets (PIs; N=6 donors, ages 16-50 years). MAFBKD PIs exhibited a 56.4±4.2% reduction (P<0.001) in MAFB mRNA compared to control. Likewise, glucagon mRNA and hormone content were reduced by 42.5±6.9 and 28.6±7.6% (P<0.05), respectively, whereas insulin expression and content were unchanged. In static hormone secretion experiments, IBMX- and arginine-stimulated glucagon secretion was blunted in MAFBKD PIs (~33% lower than control; P<0.05), an observation that was replicated in α cell-enriched MAFBKD PIs. Insulin secretion, on the other hand, was largely unaffected. Bulk RNA-sequencing analysis of MAFBKD versus control PIs illustrated downregulation of α cell identity genes, upregulation of β, delta, and gamma cell identity genes, and misexpression of PYY, a gut peptide gene. Upregulated genes were also highly enriched in gene sets associated with epithelial mesenchymal transition and transforming growth factor β signaling. Intriguingly, marker genes in both pathways were shown recently to be upregulated in T2D α cells. Our findings suggest that MAFB is a molecular “gatekeeper” of α cell identity through gene activating and repressive functions, with its loss leading to dysregulation of human glucagon secretion.

Disclosure

K.C.Coate: None. R.Stein: None. X.Tong: None. J.Liu: None. R.Jenkins: None. R.Aramandla: None. N.Dey: None. S.Kim: None. M.Brissova: None. A.C.Powers: None.
1748-P: Assessing the Presence of Delta-Cell–Mediated Electrical Coupling in the Islet
Authors: LEVITT CLAIRE H. , BENNINGER RICHARD K.
Published: June 2023

Somatostatin-producing delta cells play an important role in the regulation of paracrine cross talk in the islet through inhibition of insulin and glucagon secretion by beta and alpha cells, respectively. However, recent studies have suggested the presence of electrical coupling via gap junctions between delta and beta cells. Electrical coupling mediated cross-talk would support the correlation between pulsatile insulin and somatostatin release and reveal a structural source of cell-cell communication within the islet. To test whether beta and delta cells are gap junction coupled, we measured the permeability of cell to cell connections and the relative dynamics of Ca2+. Islets of Sst-Cre;Rosa-LSL-tdTomato mice were used which show delta-cell specific labelling. They were then loaded with the cationic dye rhodamine-123 at 5mM glucose to measure performance of fluorescence recovery after photobleaching to assess gap junction coupling of delta cells and non-delta cells. Calcium dynamics were assessed using calcium dye Fluo-4 upon stimulating the islet from low glucose (2mM or 5 mM) to high glucose(11mM). No significant differences between recovery rate were observed when comparing delta cells and beta cells (p>0.05), which indicates some level of gap junction permeability among delta cells exists. The calcium activity of a population of delta cells was similar to those of neighboring beta cells, indicating a functional connection exists between these cell types. Furthermore, first-responder beta cells showed a preferential proximity to delta cells suggesting an impact of delta cells on functional sub-populations of nearby beta-cells. These results suggest a possible feedback system exists in the islet that is governed by electrical coupling of delta cells, which is important for both the function of beta cells and insulin secretion, and may also impact secretion of other islet hormones.

Disclosure

C.H.Levitt: None. R.K.Benninger: None.

Funding

National Institute of Diabetes and Digestive and Kidney Diseases (P30DK116073, R01DK102950, R01DK106412)
1752-P: The Role of Translocon-Associated Protein Subunit γ in Insulin Biosynthesis and Glucose Homeostasis
Authors: XU NING , XU XIAOXI , HU JINGXIN , GUO JIYUN , CUI JINGQIU , LIU MING , FENG WENLI , LI XIN
Published: June 2023

Translocation-associated protein (TRAP) is a four-subunit complex located on the endoplasmic reticulum (ER) membrane, including TRAPα, TRAPβ, TRAPγ, and TRAPδ. TRAPα, TRAPβ and TRAPδ reside on the luminal side of the ER membrane for primary functionality, whereas the extra-membranous portion of TRAPγ is mainly cytosolic. Our recent studies indicate that TRAP complex contributes to the biosynthesis of proinsulin in pancreatic β cell lines and TRAPγ is a rate-limiting element of proinsulin biosynthesis. This might be partially explained by that newly made preproinsulin may first encounter the cytosolic domain of TRAPγ for translocation into the ER. To further understand the role of TRAPγ in β cells and its pathological significance in maintaining glucose homeostasis, we generated a β-cell specific TRAPγ knockout mouse model. We found that TRAPγ deficiency led to a significant reduction of insulin content in islets and a decrease of circulating insulin. TRAPγ βKO mice impaired glucose tolerance with aging, which even further deteriorated with high fat diet. In β cell line, TRAPγ deficiency resulted in less proinsulin synthesis and poor response to high glucose stimulation. Consistently, an acute exposure to high glucose increased expression of TRAPγ and proinsulin protein levels simultaneously in wild-type mouse islets. However, the ability to upregulate proinsulin response to high glucose was markedly compromised in TRAPγ βKO mouse islets. This study uncovers that TRAPγ is critical to insulin synthesis both in vivo and in vitro, which provides insight into the pathogenesis of type 2 Diabetes.

Disclosure

N.Xu: None. X.Xu: None. J.Hu: None. J.Guo: None. J.Cui: None. M.Liu: None. W.Feng: None. X.Li: None.

Funding

National Natural Science Foundation of China (81830025, 82220108014, 82100865, 81800733, 81900720, 82000796, 82070854); National Key R&D Program of China (2019YFA0802502, 2022YFE0131400); Tianjin Key Medical Discipline Construction Project (TJYXZDXK-030A)
1755-P: EndoC-ßH5 Is a Storable and Ready-to-Use Human Pancreatic Beta Cell That Can Model Type 1 and 2 Diabetes
Authors: OLLEIK HAMZA , BLANCHI BRUNO
Published: June 2023

EndoC-βH5 is a newly developed human pancreatic beta cell model and an optimized version among the EndoC-βH (EndoC-βH1/2/3) family. EndoC-βH5 cells are storable and ready-to-use and they robustly and reproducibly secrete insulin in response to glucose and incretins across experiments and laboratories. Specifically, they dose dependently respond to physiological concentrations of glucose. In addition, their response to GLP-1 and GIP receptor agonists is also highly reproducible and dose-dependent. Given the continuously increasing number of diabetes patients worldwide, the need for physiologically relevant human cellular models is greater than ever and EndoC-βH5 cells represent a novel human pancreatic beta cell solution that can help developing human diabetes models and drug screening and validation assays. In this study, we are developing pathological and drug screening models. EndoC-βH5 cells are sensitive to palmitate/high glucose as well as cytokine induced cell loss, recapitulating hallmarks of T2D. In addition, we evaluated impairment of insulin secretion and ER stress in these contexts in order to assess the mechanistic relevance of the models. We then addressed T1D modeling. We generated HLA-A2 expressing EndoC-βH5 cells and evaluated HLA-A2 alloreactive T lymphocyte activation and diabetogenic T lymphocyte induced cytotoxicity. Finally, we determined that EndoC-βH5 cells express functional glucagon (GCG) receptor, which contributes to the modulation of glucose induced insulin secretion, highlighting the potential of EndoC-βH5 as a model to study dual and triple GLP-1/GIP/GCG receptor agonists in a reproducible human cellular model. Overall, EndoC-βH5 cells appear to be a powerful tool to develop Type 1/2 diabetes and drug discovery models.

Disclosure

H.Olleik: None. B.Blanchi: Employee; Human Cell Design.
1757-P: δ-α Cell-to-Cell Interaction Modulates Pancreatic Islet Ca2+ Oscillation Modes
Authors: REN HUIXIA
Published: June 2023

Glucose-stimulated pancreatic islets show α cell mass dependent fast and slow Ca2+ oscillations. It implicates structure-function relationship is a fundamental principle of pancreatic islets. Despite the low percentage within the islet, the δ cells entangle with α cells and occupy the islet periphery, to envelop the β cells in the core. However, the contribution of the extensive δ-α paracrine organization to the origin of the variability in Ca2+ activation, remains unclear. Here we found that somatostatin’s perturbation on Ca2+ oscillation critically depended on α cell mass. Furthermore, pharmacological and opto-geneticalperturbation on δ-α cell interaction cause islets to repeatably show fast and slow Ca2+ oscillations. Our study highlights the importance of δ-α cell interactions as the origin of the variability in oscillation pattern. Studying islets in their intact pancreas morphology in tissue slice revealed that glucose recruited the δ cells to control the α and β cell activity.

Disclosure

H.Ren: None.
1758-P: Intracellular Metabolic Change in Rodent Pancreatic ß-Cells under Diabetic Condition Is Flexible and May Compensate for Glucose Intolerance
Authors: CHIBA KOKI , NOMOTO HIROSHI , IZUMIHARA RIMI , KAMEDA HIRAKU , MIYOSHI HIDEAKI , NAKAMURA AKINOBU , ATSUMI TATSUYA
Published: June 2023

Background: In pancreatic β-cells under diabetic conditions, metabolic stressors cause mitochondrial dysfunction and reduce oxidative phosphorylation, resulting in impaired intracellular metabolism. It has been suggested that aberrant activation of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3) plays a role in this impairment. However, the pathological significance of PFKFB3 activation and its flexibility are not clear.

Methods: Eight-week-old ob/ob mice were fed a standard chow ad lib or the same diet restricted to 2 g/day, or tofogliflozin added chow ad lib for 4 weeks. The body mass and glucose tolerance were compared among the groups. The expression of glycolytic enzymes in the pancreatic islets was evaluated using western blotting, immunohistochemistry and DNA microarray analysis. Next, INS-1 cells were cultured in medium containing a low (5.5 mM; low-G) or a high (22 mM: high-G) glucose concentration, or high-G with PFKFB3 inhibiter (3PO) for 48 hours. The expression of mafa and pdx-1 were evaluated using real time PCR.

Results: Ad lib-fed mice showed hyperglycemia and greater weight gain than food restricted mice and tofogliflozin treated mice. The expression of PFKFB3 and other glycolytic enzymes were higher in ad lib-fed mice, whereas such aberrant expression were suppressed by restricted feeding and tofogliflozin. DNA microarray analysis revealed increased expression of genes related to glycolytic pathway in ad lib-fed mice. However, these changes were corrected in a restricted diet and tofogliflozin groups. In INS-1 cells, high-G caused elevated pfkfb3 and decreased mafa and pdx-1 expression compared with low-G exposure. Inhibition of glycolytic pathway by 3PO in high-G environment did not normalize the defect of mafa and pdx-1.

Conclusion: The intracellular metabolic changes in pancreatic β cells associated with obesity and diabetes are flexible and may compensate for glucose intolerance.

Disclosure

K.Chiba: None. H.Nomoto: Speaker's Bureau; Novo Nordisk, Sumitomo Pharma, Co., Ltd. R.Izumihara: None. H.Kameda: None. H.Miyoshi: Research Support; Abbott, LifeScan Diabetes Institute, Taisho Pharmaceutical Holdings Co., Ltd., Speaker's Bureau; AstraZeneca, Boehringer Ingelheim Japan, Inc., Eli Lilly Japan K.K., Kowa Company, Ltd., MSD Life Science Foundation, Novo Nordisk, Ono Pharmaceutical Co., Ltd., Sanofi K.K., Mitsubishi Tanabe Pharma Corporation. A.Nakamura: Research Support; Abbott Japan Co., Ltd., Boehringer Ingelheim Japan, Inc., Daiichi Sankyo, Taisho Pharmaceutical Holdings Co., Ltd., Teijin Pharma Limited, Kowa Company, Ltd., Mitsubishi Tanabe Pharma Corporation. T.Atsumi: Speaker's Bureau; Eli Lilly Japan K.K., Kowa Company, Ltd.
176-OR: CopenFast Trial—Fetal Growth and Glycemic Control in Pregnant Women with Type 1 or Type 2 Diabetes Using Faster-Acting Insulin Aspart or Insulin Aspart—A Randomized Controlled Trial
Authors: NOERGAARD SIDSE K. , MATHIESEN ELISABETH R. , NØRGAARD KIRSTEN , CLAUSEN TINE D. , SØHOLM JULIE , HOLMAGER PERNILLE , DO NICOLINE C. , DAMM PETER , RINGHOLM LENE
Published: June 2023

Aim: To evaluate the effect of faster-acting insulin aspart (faster aspart) vs. insulin aspart (IAsp) on fetal growth and glycemic control in pregnant women with type 1 or type 2 diabetes.

Methods: In a single-center, open-label trial from November 2019 to May 2022 women were stratified by diabetes type and insulin treatment modality (multiple daily injections or insulin pump) and randomized to faster aspart or IAsp from 8 to 13 weeks. Primary outcome was offspring birthweight standard deviation (SD) score. Secondary outcomes included mild hypoglycemia (managed by the woman) in the previous week, HbA1c at inclusion, 21, 33, and 35 weeks, and severe hypoglycemia (requiring third party assistance) reported in a structured interview.

Results: In total, 216 women were included and randomized to faster aspart or IAsp (n=109 vs. n=107). Baseline data were comparable in both groups. Primary outcome data were available in 94% (71% type 1 (of which 19% on insulin pump), 29% type 2 diabetes). Offspring birthweight SD score was median 0.7 (interquartile range -0.3-2.0) vs. 1.1 (0.4-1.9), mean difference -0.2 (95% confidence interval -0.6-0.1), p=0.23 with 41% vs. 46% large for gestational age infants (p=0.39). From randomization to delivery 1 (1%) vs. 7 (7%) women reported severe hypoglycemia (p=0.07) with fewer events reported by women using faster aspart compared to IAsp (1 vs. 10 events, p=0.03). At 33 weeks, women using faster aspart reported fewer mild hypoglycemic events in the previous week compared to IAsp (2.0 (0.8 - 4.0) vs. 3.0 (1.0 - 5.0), p=0.03), while HbA1c was 41 (38-46) vs. 43 (39-46) mmol/mol, p=0.28. Prevalence of preeclampsia was 15% vs. 12% (p=0.51) and preterm delivery <37 weeks 19% vs. 22% (p=0.64). No perinatal deaths were reported.

Conclusion: In pregnant women with type 1 or type 2 diabetes, use of faster aspart resulted in comparable fetal growth and HbA1c with less severe hypoglycemia compared to IAsp.

Disclosure

S.K.Noergaard: Research Support; Novo Nordisk A/S. E.R.Mathiesen: Advisory Panel; Novo Nordisk, Research Support; Novo Nordisk, Speaker's Bureau; Novo Nordisk. K.Nørgaard: Advisory Panel; Medtronic, Novo Nordisk, Research Support; Medtronic, Dexcom, Inc., Novo Nordisk, Zealand Pharma A/S, Speaker's Bureau; Medtronic, Novo Nordisk, Stock/Shareholder; Novo Nordisk. T.D.Clausen: None. J.Søholm: Research Support; Novo Nordisk A/S. P.Holmager: None. N.C.Do: Research Support; Novo Nordisk Foundation. P.Damm: Other Relationship; Novo Nordisk A/S. L.Ringholm: Research Support; Novo Nordisk A/S.

Funding

Novo Nordisk A/S (U1111-1209-6358)
1762-P: Increased Glucose Sensing and Insulin Secretion Induced by Verapamil Is Associated with Enhanced Oxygen Consumption Rate in MIN6 ß-Cells
Authors: AREFANIAN HOSSEIN , BAHMAN FATEMAH , AL MADHOUN ASHRAF , ALZAID FAWAZ , SINDHU SARDAR T. , WILLIAMS MICHAYLA R. , ALRASHED FATEMA , NIZAM RASHEEBA , JACOB SINDHU , JOHN SUMI E. , ALHUSAYAN MOHAMMED , KURIAN SHIBU J. , ABUKHALAF NERMEEN A. , SHENOUDA STEVE , ALSAEED HALEMAH , KOCHUMON SHIHAB P. , ABU-FARHA MOHAMED , ABUBAKER JEHAD , THANGAVEL ALPHONSE T. , AHMAD RASHEED , ALMULLA FAHD
Published: June 2023

It has been shown recently that oral administration of verapamil in persons with type 1 diabetes (T1D) decreased the dependency on exogenous insulin and improved the β cell function. Additionally, it decreased the frequency of hypoglycemic events. This finding encouraged us to test the effect of verapamil on the function of MIN6 mouse β cell-line. Glucose-Stimulated Insulin Secretion (GSIS) assay was performed using static incubation method. MIN6 cells were pre-treated with 50 μM verapamil for 24 hours, then the levels of total insulin content and secreted insulin were measured before and after GSIS assay using highly sensitive mouse insulin ELISA kit. Glucose sensing was estimated by the percentage of secreted insulin over total insulin content for each concentration of glucose. The measured insulin levels were normalized by the level of total protein. Oxygen consumption rate (OCR) was measured using Seahorse system and metabolic stress kit. MIN6 cells were seeded in Agilent Seahorse XF96 cell culture microplate at a cell density of 4×104 cells/well, under normal (5.6 mM) and high (25.2 mM) glucose concentrations for 24 hours, after which, cells were treated with verapamil (50 μM) or left untreated and incubated for 24 hours. Our results show no significant difference between total insulin content of treated vs. untreated cells. GSIS data show that insulin secretion was significantly higher in verapamil-treated cells at 8.4, 11.2, and 16.8 mM, but not at 2.8 and 5.6 mM glucose. The results suggest that β cells were hypersensitized to glucose when treated with verapamil. In metabolic flux analysis for mitochondrial respiration, treatment with verapamil increased basal and maximal respiration. Taken together, our study showed that verapamil increased the level of glucose sensing and oxidative respiration under conditions of high glucose, which may explain its effect on lowering the frequency of hypoglycemic events in clinical studies.

Disclosure

H.Arefanian: None. S.E.John: None. M.Alhusayan: None. S.J.Kurian: None. N.A.Abukhalaf: None. S.Shenouda: None. H.Alsaeed: None. S.P.Kochumon: None. M.Abu-farha: None. J.Abubaker: None. A.T.Thangavel: None. F.Bahman: None. R.Ahmad: None. F.Almulla: None. A.Al madhoun: None. F.Alzaid: None. S.T.Sindhu: None. M.R.Williams: None. F.Alrashed: None. R.Nizam: None. S.Jacob: None.

Funding

Kuwait Foundation for the Advancement of Sciences (RACB-2019-001)