bluuebunny/crossref_metadata_2025 huggingface dataset:
1637-P: TLC-6740, a Liver-Targeted Mitochondrial Protonophore, Increases Energy Expenditure and Lipid Utilization in Obese Mice
Authors: SRODA NATALIE , VIJAYAKUMAR ARCHANA , MURAKAMI EISUKE , WENG STEVE , SHULMAN GERALD I. , MYERS ROBERT P. , SUBRAMANIAN MANI
Published: June 2024

Background: TLC-6740, a liver-targeted mitochondrial protonophore, causes dose-dependent weight loss and metabolic benefit in diet-induced obese mice. Here, we evaluated mechanisms of TLC-6740-induced weight loss.

Methods: Male C57 BL/6 mice housed at thermoneutrality (28°C) were fed a high-fat diet for >25 wk and dosed with vehicle (Veh) or TLC-6740 (60mg/kg) PO BID for 8 days. Energy expenditure (EE) was measured by indirect calorimetry (Days -1, 1, 6-7) and energy balance was calculated by subtracting EE from energy intake (EI).

Results: On Day 1, TLC-6740 increased EE in the dark phase by 18% compared to pre-treatment and by 24% vs Veh (Fig A). EI decreased 26% with TLC-6740 and increased 43% with Veh. Consequently, TLC-6740 induced negative energy balance (Day -1 vs 1: +1.9 vs -1.9 kcal/d) whereas a positive balance was observed with Veh (-0.06 vs +3.4 kcal/d) (Fig B). Respiratory exchange ratio (RER) decreased with TLC-6740, but not Veh, indicating a shift towards increased whole-body lipid utilization (Fig C). Increased EE with TLC-6740 (16% vs Veh) persisted over 6-7 days of dosing leading to 5% weight loss at Day 7.

Conclusions: The protonophore TLC-6740 increases EE, inducing negative energy balance and weight loss. These data support evaluation of TLC-6740 for obesity and highlights the complementarity of this mechanism to agents that reduce oral intake (e.g., incretins).

Disclosure

N. Sroda: Employee; OrsoBio, Inc. A. Vijayakumar: Employee; OrsoBio, Inc. E. Murakami: Employee; OrsoBio, Inc. S. Weng: Employee; OrsoBio, Inc. G.I. Shulman: None. R.P. Myers: Employee; OrsoBio, Inc. M. Subramanian: Board Member; OrsoBio, Inc.
165-OR: Lipid Signaling in Macrophages Contributes to Inflammatory Transcriptome in Immune Cells
Authors: ALMUTAIRI ABDULAZIZ , WELNER ROBERT S. , WHITE TAYLEUR , TUSING YING , RAMANADHAM SASANKA
Published: June 2024

Macrophages and T-cells play critical roles in β-cell death leading to T1D. We find that reduction of Ca2+-independent phospholipase A2β in macrophages alone reduces T1D. To explore the potential mechanism, we examined changes in immune-responsive genes by single-cell RNAseq analysis using a false discovery rate (FDR)<1e10-8. In the BMDM from NOD.cM ΦiPLA2 β-/-, relative to NOD, we find that genes (Slc25a5, Ephx1, Zcchc14) related to inflammation, immune cell infiltration, T-cell activation, antigen presentation, MΦ proliferation, and mitochondrial metabolism were down-regulated, and those that promote M2M Φ polarization (Ccl6) and MΦ-phagocytosis (Tbc1d10c), and reduce MΦ infiltration (Creb313), CD8 T-cell activation (Ccl4), and mitochondrial production of anti-inflammatory itaconate (Acod1) were up-regulated. Intriguingly, nearly 30 DEGs were noted in islet CD4 and CD8 T-cells from NOD.cM ΦiPLA2 β-/-, relative to NOD. In the CD4 cells, genes (Tnfrs23, Jak2, H2-Aa) related to inflammation, activation of T-cells, and antigen presentation were downregulated, whereas genes related to Treg generation (Gpr83) and negative regulation of Th-cell activation (Cd160) were upregulated. In the CD8 cells, genes associated with enhancing inflammation (Epas1, Gata3), CD8 T-cell activation (Nkg7, Ctla2b), CD4 T-cell activation (Gldc), and (4) negative modulation of Treg cell generation (Ctla2a) were down-regulated, while genes (Gbp2b, Gpr83) associated with Tregs were upregulated. Importantly, the top 7 of 16 shared T-cell pathways were related to inflammation. Similar transcriptome profiles were also evident in NOD.cM ΦiPLA2 β-/- islet B and NK cells, relative to NOD. These findings reveal that lipid signaling from macrophages affects the transcriptome in macrophages, triggering islet immune cell transcriptome favoring an inflammatory phenotype. They further suggest that targeting iPLA2β-derived lipid signaling in macrophages is a means to reduce T1D incidence.

Disclosure

A. Almutairi: None. R.S. Welner: None. T. White: None. Y. Tusing: None. S. Ramanadham: None.

Funding

NIH/NIAID 1R21AI169214-01JDRF 2-SRA-2022-1210-S-BJDRF 1-INO-2023-1344-A-NNIH/NIAID 1 R21 AI 146743UAB Department of CDIBUAB Comprehensive Diabetes Center
1661-P: Petrelintide (ZP8396) Selectively Reduces Intake of High-Fat Diet in DIO Rats
Authors: VESTERGAARD BILL , BAADER-PAGLER TAMARA , GRIFFIN JON
Published: June 2024

The obesity pandemic is a major health crisis and there is a need for effective pharmacotherapies. Overconsumption of highly palatable food is associated with obesity. Petrelintide, a novel once-weekly amylin analog currently in phase 1 clinical testing, induces meaningful reductions in body weight in lean and overweight subjects. Here we investigate the effect of petrelintide on food preference in DIO (diet-induced obese) rats to determine whether petrelintide holds the potential to address overconsumption of highly palatable food in humans.DIO rats were given ad libitum access to chow diet and high fat diet during a 30-day treatment period. Animals were treated with either vehicle (every second day), liraglutide (5 nmol/kg twice daily) or petrelintide (2 nmol/kg every second day or 10 nmol/kg every fourth day). Body weight, chow intake and high fat diet intake were measured daily.

Treatment with liraglutide and petrelintide resulted in significant lower relative body weight compared to vehicle (3.3 % ± 0.7 vehicle, -0.1 % ± 1.1 liraglutide, -4.1 % ±0.6 petrelintide 2 nmol/kg, -7.8 % ± 0.7 petrelintide 10 nmol/kg; relative to initial body weights ± SEM). Treatment with petrelintide resulted in significant reduction of total cumulative intake of high fat diet compared to vehicle, in contrast to liraglutide (834 g ± 31.1 vehicle, 796 g ± 25.6 liraglutide, 646 g ± 22.3 petrelintide 2 nmol/kg, 576 g ± 17.4 petrelintide 10 nmol/kg; g ± SEM). No change in total cumulative intake of chow was observed in any groups compared to vehicle.

In conclusion, petrelintide reduces food intake and body weight in DIO rats primarily by lowering intake of high fat diet. Based on these findings petrelintide might hold the potential to address overconsumption of highly palatable food in humans. Petrelintide is currently being explored in a multiple ascending dose (MAD) study to assess the potential for the management of obesity.

Disclosure

B. Vestergaard: Employee; Zealand Pharma A/S, Novo Nordisk A/S. T. Baader-Pagler: Employee; Boehringer-Ingelheim. J. Griffin: Employee; Zealand Pharma A/S.
1667-P: Mesenteric Visceral Lipectomy (MVL) Improves Glucose Tolerance in Patients with Type 2 Diabetes (T2D)
Authors: BASKOY GOZDE , PETERSON RICHARD M. , KEMPENICH JASON W. , TRIPLITT CURTIS L. , CLARKE GEOFFREY D. , CERSOSIMO EUGENIO , ANDREW MARK S. , MEROVCI AURORA , LAVRYNENKO OLGA , HANSIS-DIARTE ANDREA A. , SOLIS-HERRERA CAROLINA , CHAVEZ ALBERTO , SALEHI MARZIEH , DEFRONZO RALPH A.
Published: June 2024

Aim: To evaluate the safety and metabolic effects of mesenteric visceral lipectomy in individuals with T2D.

Methods & Study Design: Eight T2D subjects (age = 52±4 y; BMI = 34.1±1.0; stable diabetes meds/weight for 3 months) underwent pre-MVL assessment including OGTT, CGM, euglycemic insulin clamp with 3H-glucose, and MRI imaging. Repeat measurements were made at 6- and 12-months post-surgery. Exclusion criteria included prior insulin/TZD use. Insulin secretion [IS], Disposition Index [DI] and Matsuda index [MI] of insulin sensitivity were calculated with standard formulae.

Results: At month 6, HbA1c decreased from 9.0% to 8.1% (p=0.08) and persisted at 8.4% at month 12 (p=0.19). CGM time-in-range increased significantly at 6 and 12 months (25% to 76%) (p<0.05). Suppression of hepatic glucose production increased at months 6 and 12 (p<0.05). Body weight and % body fat decreased slightly at month 12 (p<0.05). Insulin secretion and disposition index during OGTT increased more than 2-fold at month 6 and persisted at month 12.

Disclosure

G. Baskoy: None. R.M. Peterson: Consultant; Teleflex/Standard Bariatrics. J.W. Kempenich: Consultant; Intuitive Surgical. C.L. Triplitt: Speaker's Bureau; Novo Nordisk. Consultant; Eli Lilly and Company. Other Relationship; American Diabetes Association. G.D. Clarke: None. E. Cersosimo: None. M.S. Andrew: Employee; Medality Medical, Inc. A. Merovci: None. O. Lavrynenko: None. A.A. Hansis-Diarte: None. C. Solis-Herrera: Advisory Panel; Novo Nordisk, Bayer Inc. A. Chavez: None. M. Salehi: None. R.A. DeFronzo: Advisory Panel; AstraZeneca, Novo Nordisk, Boehringer-Ingelheim, Intarcia Therapeutics, Inc., Aardvark, Renalytix, Corcept Therapeutics, Alnylam Pharmaceuticals, Inc. Research Support; Boehringer-Ingelheim, AstraZeneca, 89bio, Inc., Amgen Inc., Medality, Corcept Therapeutics. Speaker's Bureau; AstraZeneca, Corcept Therapeutics, Renalytix.

Funding

Medality
1687-P: Similarities and Differences between Metabolically Unhealthy Lean and Metabolically Unhealthy Obese Individuals
Authors: ANAND SEERAT , PASUPNETI TEJASVI , PAK YOUNGJU , GARG RAJESH K.
Published: June 2024

Metabolic abnormalities are present in 15-25% adults with BMI <25 kg/m2. Studies have shown an increased amount of visceral fat in metabolically unhealthy lean (MUL) individuals as compared to metabolically healthy lean (MHL) individuals. The same is true for metabolically unhealthy obese (MUO) as compared to metabolically healthy obese (MHO) individuals. However, the lean and obese groups have not been compared for other similarities or differences. We used NHANES data for years 2011 - 2018 and downloaded variables related to demographics, laboratory, and dual energy x-ray absorptiometry. Being metabolically unhealthy was defined as the presence of ≥2 components of the metabolic syndrome other than obesity. After excluding those <18 years, the study sample included 6,834 subjects with BMI <25 kg/m2 and 8,564 with BMI ≥30 kg/m2. The comparisons between MUL Vs MHL and MUO Vs MHO are shown in the table. We found that MUL individuals had increased total percent fat mass and increased android percent fat as compared to MHL individuals. However, MUO individuals had similar total and android fat but lower gynoid fat as compared to MHO individuals. Thus, while MUL and MUO subjects both had increased android to gynoid ratio, there were differences in fat distribution. This suggests that the underlying mechanisms in MUL individuals may be different from the MUO individuals and need further investigation.

Disclosure

S. Anand: None. T. Pasupneti: None. Y. Pak: None. R.K. Garg: None.
1688-P: Type 2 Diabetes Remission after Metabolic and Bariatric Surgery—A Systematic Review and Meta-analysis Comparing Less Obese and Severely Obese Individuals
Authors: HYUN BAE JAE , HOON KIM NAM
Published: June 2024

Introduction & Objective: Metabolic and bariatric surgery (MBS) effectively induces diabetes remission in severely obese individuals. However, its impact on those with less severe obesity remains uncertain. We investigated type 2 diabetes remission after MBS based on preoperative body mass index (BMI).

Methods: We searched MEDLINE, Embase, and the Cochrane Library databases up to May 2021, focusing on diabetes remission concerning BMI without restricting to intervention-comparison studies. We included clinical trials, cohort studies, and consecutive case series involving ≥50 individuals with type 2 diabetes who underwent MBS and reported diabetes remission. Studies were categorized by preoperative BMI (<35 kg/m2 or ≥35 kg/m2). The primary outcome was diabetes remission (HbA1c <6.5% without antidiabetic medication) at different post-surgery intervals, with analysis of HbA1c and BMI changes. We used meta-regression for between-group comparisons and assessed potential bias.

Results: Eighty-one studies were included (23 with BMI <35 kg/m2, 58 with BMI ≥35 kg/m2). At 12 months, diabetes remission rates were 0.59 (95% CI 0.49 to 0.70) for BMI <35 kg/m2, and 0.61 (0.55 to 0.67) for BMI ≥35 kg/m2. No significant between-group differences were observed at 12 months (adjusted weighted mean difference [WMD] −0.01, 95% CI −0.14 to 0.12), 24 months (adjusted WMD −0.04, 95% CI −0.29 to 0.21), 36 months (adjusted WMD 0.00, 95% CI −0.22 to 0.23), and ≥60 months (adjusted WMD −0.02, 95% CI −0.25 to 0.22). Achieved HbA1c levels were comparable, but BMI remained higher in those with BMI ≥35 kg/m2.

Conclusions: Our study demonstrates that diabetes remission after MBS is similar between individuals with BMI <35 kg/m2 and BMI ≥35 kg/m2 over the long-term follow-up.

Disclosure

J. Bae: None. N. Kim: None.
1706-P: Software-Aided Self Selection of Weight Loss Diet Plan for Facilitating Diabetes Management in Primary Care
Authors: WHIGHAM LEAH , DHURANDHAR NIKHIL
Published: June 2024

Introduction and Objectives: The addition of a new anti-diabetes drugs have further strengthened pharmacological management of diabetes. However, attention to diet continues to be a cornerstone of diabetes management, particularly because of the preponderance of obesity in individuals with diabetes. Our objective was to address the gap experienced by many diabetes care providers in providing effective dietary guidance.

Methods: We developed Small Changes, a software program that facilitates patient-selected meal planning. Bilingual videos instruct patients on selection of meal options that align with their usual eating habits and dietary preferences, including options for from-scratch recipe, convenience foods, and restaurant options. The algorithm provides a structured meal plan that includes instructions and recipes based on patient selections and tailored to the patient’s calorie needs for weight loss (~ 500 Calorie deficit from daily energy requirements based on Mifflin St. Jeor equation). Macronutrients are distributed throughout the day to optimize fat loss and reduce hunger (~20% Cal as protein, <30% as fat), while providing patients with moderate flexibility in choices to enhance compliance.

Results: Mixed methods pilot testing in multiple settings indicates high patient and provider satisfaction and average weight loss that is clinically significant (>5%). Providers indicated program addressed a need for dietary guidance that was not time consuming and did not require clinic personnel to have extensive nutrition knowledge. Patients expressed appreciation for variety and flexibility of the program.

Conclusion: Software-based tools that support nutrition guidance for weight loss offer a scalable approach to meet an important need in diabetes management.

Disclosure

L. Whigham: None. N. Dhurandhar: Advisory Panel; Medifast, Inc. Research Support; Insparin Inc, Borealis Foods, National Cattleman's Beef Association, Novo Nordisk.
1707-P: Real-World 12-Month Weight Loss Outcomes of Tirzepatide—The Mayo Clinic Experience
Authors: FANSA SIMA , TAMA ELIF , SAFWAN NANCY , GHUSN WISSAM , ANAZCO DIEGO , ACOSTA ANDRES , HURTADO MARIA D.
Published: June 2024

Introduction: Tirzepatide, a dual GIP/GLP-1 receptor agonist, has been recently approved for the treatment of overweight and obesity given its proven effectiveness and safety in phase 3 clinical trials. In this study, we aim to evaluate weight loss outcomes associated with tirzepatide in the real-world setting.

Methods: This is a retrospective cohort study of adults taking tirzepatide for the treatment of overweight or obesity. Endpoints: total body weight loss percentage (TBWL%) at 3, 6, and 12 months; TBWL% difference by type 2 diabetes (T2D) status; proportion of patients achieving ≥5%, ≥10%, ≥15% and ≥20% of TBWL% at 12 months; and side effects. We used paired t-test to assess TBWL% compared to baseline and non-paired t-test to compare TBWL% by T2D status. Results are presented as mean ± standard deviation.

Results: We included 200 patients: 78% female, 91% White, age 50±12 y, BMI 39±8 kg/m2, 36.5% with T2D. Most patients were on 15 mg (26.5%) or 7.5 mg (20.0%) of tirzepatide weekly. TBWL% at 3, 6, and 12 months were -9±5% (n= 138, p<0.001), -12±6% (n= 113, p<0.001), and -17±9% (n= 97, p<0.001), respectively. Compared to patients without T2D, those with T2D lost less weight at 12 months: -14±9% vs. -19±9%, p=0.01. The percentages of patients losing ≥5%, ≥10%, ≥15% and ≥20% of TBWL% at 12 months were 90%, 73%, 57%, and 40%. Only 11% and 6% of patients received nutritional and behavioral support, respectively. Side effects were reported by 29% of patients. The most frequent was nausea (18%). Seven patients (4%) discontinued tirzepatide due to side effects.

Conclusion: In the real-world setting, tirzepatide led to substantial weight loss at 12 months in patients with and without T2D, comparable to what has been reported in pivotal trials. Future real-world studies with a larger number of participants are needed to better assess the long-term efficacy, safety, and tolerability of tirzepatide in this setting.

Disclosure

S. Fansa: None. E. Tama: None. N. Safwan: None. W. Ghusn: None. D. Anazco: None. A. Acosta: Consultant; Amgen Inc., Regeneron Pharmaceuticals Inc., Nestlé Health Science, Structure Therapeutics, Inc., Boehringer-Ingelheim. Research Support; Vivus. Consultant; Currax. Other Relationship; Gila Therapeutics, Phenomix Sciences. Speaker's Bureau; Eli Lilly and Company. M.D. Hurtado: None.

Funding

National Institutes of Health (K12AR084222)
1713-P: Acute Beta Cell Deletion of Grp78 Causes Diabetes in Adult Male Mice
Authors: BURTON JOSHUA , CASTRO THALIA , HASSAN HIBO A. , DIAZ MOSQUEA HILLARY , ALONSO LAURA C.
Published: June 2024

Introduction: GRP78 is a stress-inducible endoplasmic reticulum (ER) chaperone and a key regulator of the unfolded protein response (UPR). Pancreatic beta cells are particularly susceptible to ER stress in order to adapt to increased insulin demand. It is unknown whether mature beta cells require GRP78 function for basal homeostasis. In this study, we investigated the impact of reducing GRP78 abundance in beta cells of adult mice in unstressed conditions. We hypothesized that loss of GRP78 activity results in decompensation and beta cell failure.

Methods: MIP-CreERT mice were bred to mice harboring loxP sites flanking exons 5-7 of the Grp78 gene. Male and female adults, genotypes Cre+Grp78 +/+ ("+/+"), Cre+Grp78 f/+ (“f/+”), and Cre+Grp78 f/f (“f/f"), were administered five daily doses of tamoxifen by oral gavage. Metabolic parameters were assessed and mice were sacrificed 10 days after the last tamoxifen dose for pancreas histology.

Results: GRP78 protein abundance was reduced in f/f beta cells relative to f/+ and +/+ beta cells by immunofluorescence. Grp78 deletion increased random blood glucose in male and female f/f mice compared to f/+ and +/+ controls. Males were more severely affected than females; f/f males also had elevated fasting glucose, impaired glucose tolerance, and weight loss. Random plasma insulin levels were reduced in some but not all mice. Pancreas weight was unaffected by Grp78 deletion. Beta cell mass was reduced in male f/f mice, islet architecture and cellular composition were distorted, with reduced frequency of beta cells and increased relative frequency of alpha cells. Interestingly, beta cell proliferation and beta cell death death were both significantly increased by Grp78 deletion.

Conclusions: Acute deletion of Grp78 in beta cells rapidly induces beta cell loss and diabetes in adult male mice. Beta cell GRP78 is important for maintaining whole-body glucose homeostasis. Impairment in GRP78 abundance or function in beta cells may contribute to the pathogenesis of diabetes

Disclosure

J. Burton: None. T. Castro: None. H.A. Hassan: None. H. Diaz Mosquea: None. L.C. Alonso: None.

Funding

National Institutes of Health (R01DK113300)
1730-P: In Vitro and In Vivo Effects of Increased IAPP Expression on Human Islet Function
Authors: WRIGHT JORDAN J. , JACKSON PAIGE B. , ARAMANDLA RADHIKA , DAVIS COREY , BRISSOVA MARCELA , POWERS ALVIN C.
Published: June 2024

Introduction & Objective: Islet amyloid composed of islet amyloid polypeptide (IAPP) is often present in the pancreas in type 2 diabetes. Cell culture and transgenic rodent models have been used to study islet amyloid toxicity, but less is known about the effects of endogenously-produced IAPP on human islet function and health.

Methods: To evaluate acute and chronic effects of amyloid formation, we established a pseudoislet platform with adenoviral delivery of constructs expressing human IAPP (huIAPP) or mouse IAPP (moIAPP), which is not amyloidogenic. After 7 days in culture +/- exposure to the fatty acid palmitate, pseudoislets were evaluated for secretory function, islet structure and amyloid formation by ThioS staining. Pseudoislets were also transplanted into the anterior chamber of the eye of immunodeficient mice for assessment of secretory function for up to 3 months.

Results: After 7 days in culture, transduced pseudoislets had 6.3 fold greater cellular IAPP content than untransduced pseudoislets. HuIAPP expression resulted in greater amyloid formation (0.49 ± 0.12 vs 0.17 ± 0.07 % islet area), but no changes in insulin or glucagon secretion or cellular toxicity, compared with moIAPP pseudoislets. High resolution microscopy showed ThioS+ fibrils in the ER of huIAPP-expressing beta cells. No extracellular amyloid was seen. Exposure to 0.5mM palmitate for 3 days further increased amyloid deposition and impaired insulin secretion by huIAPP pseudoislets, but not moIAPP. HuIAPP pseudoislets transplanted into immunodeficient mice had normal insulin secretion after 4 and 8 weeks, but impaired secretion after 12 weeks, compared to moIAPP pseudoislets.

Conclusion: In vitro overexpression of IAPP in human pseudoislets induces intracellular amyloid formation, and in combination with lipotoxic stress, impairs insulin secretion. In vivo, human IAPP overexpression impairs insulin secretion after three months. This model will be valuable to elucidate mechanisms of islet dysfunction in type 2 diabetes.

Disclosure

J.J. Wright: None. P.B. Jackson: None. R. Aramandla: None. C. Davis: None. M. Brissova: None. A.C. Powers: None.

Funding

National Institutes of Health (K08DK133691); Veterans Administration (IK2BX005910)
1736-P: Exploring Intrinsic Features of Human Pancreatic a- and ß-Cell Physiology Using Pseudoislets
Authors: ROZO ANDREA V. , ROMAN JEFFEREY , QIN WEI , LIU CHENGYANG , NAJI ALI , KAESTNER KLAUS H. , HOSHI TOSHINORI , STOFFERS DORIS A. , DOLIBA NICOLAI M.
Published: June 2024

Introduction: Mechanistic studies of pancreatic α- and β-cell physiology are challenging in whole islets due to interactions among different islet cell types. Reaggregation of sorted cell populations into pseudoislets offers the possibility to delineate the role of specific cell types, distinguish intrinsic cellular functions and paracrine interactions, and enhance accessibility for genetic interventions.

Methods: Building on methods of Walker et al, 2020, we generated >90% enriched human α- and β-cell aggregates and studied hormone secretion by perifusion, mitochondrial function by Seahorse, Ca2+ flux by fluorescence imaging, and electrophysiology by whole-cell patch-clamp. Native islets and pseudoislets of dissociated unsorted islet cells served as controls.

Results: The native islet kinetics of insulin and glucagon responses to glucose were preserved in β- and α-cell aggregates, indicating direct effects of glucose; however, rates of secretion, adjusted for IEQ and cell proportion, were markedly lower compared to native islets and reaggregated controls, suggesting that optimal α- and β-cell function depends on other islet cell types. The primary stimulus of oxygen consumption rate (OCR) and Ca2+ flux in β- and α-cell aggregates was glucose and amino acids, respectively. Baseline OCR (no substrate) was higher in α- than β-cell aggregates. Electrophysiologically, both native islet and α-cell aggregate action potentials (APs) were larger in size and faster in kinetics than β-cell APs; however, high glucose-induced inhibition of α-cell APs and subsequent hyperpolarization observed in native islets and control reaggregates was noticeably impaired in α-cell aggregates, suggesting a role for other cell types in glucose-mediated inhibition of α-cells.

Conclusion: Cardinal features of α- and β-cell physiology are largely preserved in α- and β-cell enriched pseudoislets, establishing its feasibility in the study of intrinsic α- and β-cell physiology.

Disclosure

A.V. Rozo: None. J. Roman: None. W. Qin: None. C. Liu: None. A. Naji: None. K.H. Kaestner: None. T. Hoshi: None. D.A. Stoffers: Other Relationship; Eiger BioPharmaceuticals. N.M. Doliba: None.

Funding

National Institutes of Health (UC4DK 112217, U01DK123594)
1740-P: The Effects of SGLT2 Inhibitor Canagliflozin on Glucagon Secretion in SUR1 Knockout Mice
Authors: ZHANG TINGTING , HAN DONGNA , MENG SHI , LI RUYUE , LI CHANGHONG
Published: June 2024

Studies have showed that some of SGLT2 inhibitors increased the release of glucagon. But the selective SGLT2 inhibitors, such as canagliflozin, don’t directly stimulate glucagon secretion due to its low SGLT1 potency. Congenital hyperinsulinism due to KATP channels loss-of-function mutations have suppressed glucagon secretion. We therefore applied canagliflozin to SUR1 knockout (SUR1-/-) mice to investigate if SGLT2i could affect glucagon secretion when both β- and α-cells are constantly depolarized. Single dose of canagliflozin (30 mg/Kg) were orally administered to wildtype mice (WT) and SUR1-/- mice, then followed by an oral glucose challenge. Glucose, insulin, and glucagon were measured. Glucagon secretion was also studied in isolated islets. Compared to vehicle controls, canagliflozin significantly lowered glucose levels and improved glucose tolerance in WT mice without altering insulin and glucagon secretion. Ratios of insulin and glucagon to glucose were unchanged after 30 min of glucose challenge. In SUR1-/- mice, canagliflozin did not affect glucose and insulin levels, but it significantly increased glucagon secretion. Canagliflozin also enhanced glucose tolerance in SUR1-/- mice with improved insulin/glucose ratio and elevated ratio of glucagon/glucose. In isolated islets, canagliflozin (10 µM) has no effects on amino acid mixture (AAM) stimulated glucagon secretion and glucose mediated suppression of glucagon secretion in WT islets. SUR1-/- islets are sensitive to AAM stimulated insulin secretion, but lack of glucose suppression of glucagon secretion, and canagliflozin does not change such pattern. However, canagliflozin induced a 2-fold increase of basal glucagon secretion in SUR1-/- islets. This study showed that when α-cells were depolarized by KATP channel deletion, canagliflozin stimulated glucagon secretion both in vivo and in isolated islets, suggesting that SGLT2 inhibitors have intrinsic effects on α-cells.

Disclosure

T. Zhang: None. D. Han: Employee; Nanjing Ascendrare Pharmaceutical Technology. S. Meng: Employee; Nanjing Ascendrare Pharmaceutical Technology. R. Li: Employee; Nanjing Ascendrare Pharmaceutical Technology. C. Li: Employee; Hua Medicine (Shanghai) LTD., Nanjing AscendRare Pharmaceutical Technology.

Funding

National Natural Science Foundation of China (82070802)
1758-P: Biased GPBAR Signaling in Regulating Islet Homeostasis and Glucose Metabolism
Authors: SUN JINPENG , YU XIAO , CHENG JIE , SHANG PAN
Published: June 2024

Introduction & Objective: The bile acid membrane receptor GPBAR is an important drug development target for metabolic diseases. Previous studies have demonstrated that some bile acids and their analogues improve glucose metabolism homeostasis by activating GPBAR in vivo.

Results: We found that, in contrast to the endogenous ligand LCA, INT-777 exhibited a Gs-preference while P395 and OA exhibited a β-arrestin-2-bias. In the study, we selected natural product oleanolic acid (OA), bile acid analogue INT-777, endogenous bile acid and small molecule Gpbar agonist P395 to evaluate their effects in islets and found that INT-777 and P395 promoted glucose-stimulated insulin secretion at lower concentrations in pancreatic islets, while natural multiple bile acids as well as OA increased insulin secretion stimulated by high glucose only at high concentrations, as evidenced by Gpbar-/- mice. In an immune factor-induced islet inflammation model, low concentrations of INT-777 and P395 were shown to exert anti-inflammatory effects, while natural bile acids and OA required high concentrations to exhibit similar effects. Moreover, the ligands that displayed an obvious for Gs signaling, INT-777 and LCA could significantly inhibit the endoplasmic reticulum stress induced by thapsigargin, but P395 did not, which were evidenced by pdx1-cre+/-Gsfl/fl mice and Arrb2-/- mice.

Conclusion: These findings collectively indicated that ligands of GPBAR with Gs-biased viability, may could better improve islet homeostasis and provide a rational design of GPBAR-targeting drugs for diabetes or other metabolic diseases.

Disclosure

J. Sun: None. X. Yu: None. J. Cheng: None. P. Shang: None.
1763-P: ATF6 Drives Glucose-Dependent Beta-Cell Proliferation by Increasing E2F1 Expression and Activity
Authors: LANDA GALVAN HUGUET V. , CASTRO THALIA , NOEL JAHI J. , AVILA LLAMAS GABRIEL , SHARMA ROHIT B. , ALONSO LAURA C.
Published: June 2024

Introduction and Objective: During elevated insulin demand, beta cells activate the Unfolded Protein Response (UPR); some also undergo proliferation. Activation of the ATF6 arm of the UPR induces beta cell proliferation, but only in high glucose. We aimed to identify the mechanism by which ATF6 increases proliferation, and how beta cells permit ATF6-driven replication in high glucose (HG: 15 mM) but not normal glucose (NG: 7.5 mM).

Methods: To acutely induce ATF6 activation, dispersed mouse and human islet cells were transduced with adenovirus expressing the N terminal domain of ATF6 fused to a destabilized DHFR; stabilizing DHFR with TMP activates ATF6. Beta cell proliferation was quantified by BrdU in insulin+ cells; mRNA or protein levels were estimated by qPCR or Western blot.

Results: ATF6 activation increased Cyclin E1 and Cyclin A2 but reduced Cyclin D2 levels. Surprisingly, ATF6 robustly induced E2F1 mRNA and protein in both NG and HG, even though ATF6 only increased proliferation in HG. E2F1 activity, measured by transcriptional targets Pola1, Mcm5, and Clspn, only increased in HG. pRb, a key inhibitor of E2F1, was phosphorylated (deactivated) only in HG, explaining low E2F1 activity in NG. Overexpressing active CDK4, which phosphorylates pRb, bypassed the requirement for HG and rescued ATF6-driven proliferation in NG in mouse beta cells. In human islet cells, overexpressing CDK6, but not CDK4, synergized with ATF6 activation to robustly increase beta cell proliferation.

Conclusion: Beta cells engage a safety mechanism to avoid inappropriate cell number increase by allowing stress-induced replication only during glucose excess. Here we establish E2F1 as a key ATF6 target driving proliferation and identify CDK4/6-pRb as a glucose sensor that permits ATF6-induced E2F1 to expand beta cell number only when more insulin is needed.

Disclosure

H.V. Landa Galvan: None. T. Castro: None. J.J. Noel: None. G. Avila Llamas: None. R.B. Sharma: None. L.C. Alonso: None.

Funding

National Institute of Diabetes and Digestive and Kidney Diseases (R01DK124906), (R01DK114686), (R01DK113300), and (R01DK135304)
1764-P: Cross Talk between Pancreatic Mesenchymal Stem Cells and Macrophages Facilitates ß-Cell Decompensation in Obesity
Authors: XU WEILONG , JIN LIANG , YU JIANGYI
Published: June 2024

Introduction & Objective: Obesity has long been recognized as a significant risk factor for developing type 2 diabetes mellitus (T2DM), the mechanisms triggering β-cell compensation and subsequent decompensation are still not fully understood. Our research has brought to light that in conditions of decompensation, macrophage presence in pancreatic islets is significantly increased while the population of mesenchymal stem cells (MSCs) concurrently decreases, which may reveal the true cause of dynamic change of pancreatic islets.

Methods: Single-cell sequencing methods can comprehensively characterize the diversity of cell types. In this study, we utilized a murine model of T2DM, established by feeding wild-type C57BL/6J mice with a high-fat diet (HFD), combining single-cell sequencing technology to investigate the effects and molecular mechanisms of cell interaction on β-cell decompensation.

Results: Our results show that pancreatic islet macrophages cause TNF-α dependent inhibition of Wnts release in MSCs, which leads to a decrease in β-cell numbers and insulin secretion. We also demonstrated that the loss of macrophages somewhat alleviates obesity-induced insulin resistance, while the injection of fresh MSCs can completely reverse β-cell decompensation. Meanwhile protective measures against HFD-induced β-cell dysfunction in mice were observed following the selective removal of macrophages and the subsequent introduction of MSCs.

Conclusion: These findings underscore the pivotal role of communication between macrophages and MSCs in modulating β-cell adaptive responses and functional impairment in obesity. Elucidating a precise mechanism for the effect of obesity on interaction between macrophages and MSCs will broaden our understanding of the pathophysiological development of diabetes and facilitate the design of better tools for diabetes prevention and treatment.

Disclosure

W. Xu: None. L. Jin: None. J. Yu: None.

Funding

National Natural Science Foundation of China (82205025,82174293,82104751); Forth Batch of Construction Program for Inheritance Office of Jiangsu Province Famous TCM Experts (No.[2021]7).
1771-P: Comprehensive Characterization of Individual Extracellular Vesicles from Beta-Cell Model Systems
Authors: ABUELREICH SARAH , LIMA CARINNA , ESPARZA DIANA , GHAELI IMA , THURMOND DEBBIE C. , JOVANOVIC-TALISMAN TIJANA
Published: June 2024

In the United States, type II diabetes is prevalent in approximately 34-36 million Americans. To improve patient outcomes, extracellular vesicles (EVs) have emerged as an exciting potential modality. EVs are nano-scale particles released from all types of cells; they contain metabolites, nucleic acids, proteins, and lipids. EVs are an exciting source of biomarkers, a promising avenue for therapeutics, and important in understanding intercellular communication. Due to the heterogeneity of EVs from complex biofluids and the low abundance of EVs from specific organs (e.g., beta cells) it is technically challenging to isolate and characterize EVs from specific cell types. Towards this, we developed a new tool to molecularly characterize individual, low-abundant EVs. We used our Single Extracellular Vesicle Nanoscopy (SEVEN) approach, which combines affinity isolation and super-resolution microscopy, to characterize EVs from beta cell model systems. In particular, we characterized EVs from INS-1 832/13 beta cells, EndoC-beta H1 cells, and nondiabetic cadaveric human islets cultured ex vivo from two donors; EVs from L6.GLUT4myc myotube cells served as controls. The average diameter of beta cell EV ranged from 84 nm (islets) to 95 nm (INS-1 cells), while the average detected number of tetraspanins CD9, CD63, and CD81 ranged from 12 (INS-1 cells) to 17 (islets); as expected, all EVs displayed large heterogeneities in size, content, and circularity. In summary, we molecularly characterized individual EVs from cultured beta cell model systems and deciphered unique multiparametric information about their properties. This work paves the road to understanding the unique properties of EVs from beta cells. Ultimately, we hope to exploit these tools to better understand the role of EVs in normal and diabetogenic conditions.

Disclosure

S. Abuelreich: None. C. Lima: None. D. Esparza: None. I. Ghaeli: None. D.C. Thurmond: Consultant; Truebindings. T. Jovanovic-Talisman: None.

Funding

Dorrance Family Research FundWanek Family and City of HopeCUBRINIDDK 1T32DK131943
1780-LB: Establishing a Mouse Model Resembling UTI Development in the Context of Type 2 Diabetes
Authors: SANCHEZ-ZAMORA YURIKO I. , LOPEZ-TORRES JEIMY M. , LI ROLLIN , OLIVERIO ALEXANDRIA , COTZOMI-ORTEGA ISRAEL , SANCHEZ-ORELLANA GAMALIEL , DE DIOS RUIZ-ROSADO JUAN
Published: June 2024

Introduction and Objective: Urinary tract infections (UTIs) are more severe in patients with type 2 diabetes mellitus (T2DM) due to various factors such as glycosuria and impaired immune responses. However, the precise mechanisms by which uropathogens exploit these conditions to colonize the urinary tract remain inadequately understood, partly due to the absence of suitable animal models. This study aims to establish a mouse model that mimics UTI development in individuals with diet-induced T2DM (UTI-T2DM model).

Methods: Diet-induced obese (DIO) male mice were fed special diets for 12, 16, and 20 weeks-high-fat diet (HFD, 60% fat) or low-fat diet (LFD, 10% fat). Subsequently, HFD and LFD mice were infected with uropathogenic E. coli (UPEC, 1x108 CFUs) via transurethral inoculation. Diabetes-like criteria were assessed through body weight, glucose levels, insulin levels, and oral glucose tolerance tests (OGTT). Bacterial burden was measured at 24- and 48-hours post-infection in collected bladders, prostates, ureters, and kidneys. The antimicrobial capacity of neutrophils isolated from infected HFD and LFD mice was evaluated. Differences between groups were analyzed using the t-test and Mann-Whitney U test, p-value is ≤0.05.

Results: DIO-HFD mice present higher body weight, hyperglycemia and hyperinsulinemia at 12, 16 and 20 w.s.d. compared to LFD mice. DIO-HFD mice exhibited significantly more bacterial burden in the urinary tract compared to LFD mice at 20 w.s.d. The bactericidal capacity of neutrophils from DIO-HFD mice was significantly impaired compared to their LFD counterparts.

Conclusions: DIO-HFD mice exhibit features resembling human T2DM and are significantly more susceptible to UTIs, making them a valuable model for investigating UTI susceptibility in the setting of diabetes.

Disclosure

Y.I. Sanchez-Zamora: None. J.M. Lopez-Torres: None. R. Li: None. A. Oliverio: None. I. Cotzomi-Ortega: None. G. Sanchez-Orellana: None. J. Ruiz-Rosado: None.

Funding

Research Institute at Nationwide Children's Hospital (AWD0000TBD), K01 NIH (DK128379).
1797-LB: Detection of Potential Therapeutic Target Associated with Coronary Artery Disease in Type 2 Diabetes Patients—System Biology Approach
Authors: MALIK ZUBBAIR , DASHTI MOHAMMED H. , JOHN SUMI E. , NIZAM RASHEEBA , AL-MULLA FAHD , THANGAVEL ALPHONSE T.
Published: June 2024

Introduction & Objective: Type 2 diabetes (T2D) and coronary artery disease (CAD), co-morbidity of which presents mortality risk, are both systemic diseases linked with altered immune response. Treatments for the co-morbid condition of T2D and CAD are not yet developed to a satisfactory level, because of lack in the understanding the linkage between them. We aim to investigate the genes that are co-expressed in T2D and CAD in order to gain a better understanding of the common causal relationship between these diseases, and to identify potential biomarkers and targets for the treatment of T2D and CAD.

Methods: We identified differentially expressed genes (DEGs) that are co-expressed in T2D and CAD genes from CAD and T2DM patients. We performed pathways analysis to predict the commonalities between the signaling pathways and molecular networks attributed to these two diseases.

Results: We identified 451 DEGs in T2D and 644 DEGs in CAD patients compared with healthy controls. Of these DEGs, 32 were shared between the two comparisons. These common DEGs significantly mapped to shared pathways. Such shared pathways can be considered as partly accounting the associations between these two disorders. Of the common DEGs, TLR4, IGF1, UBB, MAPK1, CCND1, MYC, JUN and MMP9 are key genes of the molecular network with acceptable diagnostic power in T2DM and CAD datasets. We further predicted the miRNAs and transcription factors for these key genes.

Conclusion: Our study identified key genes that might play critical roles in both T2D and CAD. These findings may lead new understanding of the associations between CAD and T2D and facilitate novel treatment or prevention strategies. However, further experimental validations and clinical trials need to be pursued to verify our results.

Disclosure

Z. Malik: None. R. Nizam: None. F. Al-Mulla: None. A.T. Thangavel: None.
18-PUB: The Efficacy and Safety of Oral Antidiabetic Drugs Added to Short-Term CSII in Patients with Type 2 Diabetes
Authors: JIANG WEI , CHEN DANRUI , XU WEN , ZENG LONGYI
Published: June 2024

Objective: Short-term continuous subcutaneous insulin infusion (CSII) has been proved to be efficacy in T2D patients. However, limited evidence is available about the effect of oral anti-diabetic drugs (OADs) added to short-term CSII in T2D. This study is aimed to compare the efficacy of OADs added to CSII with CSII alone on glucose control and glycemic variability (GV) in T2D.

Methods: A total of 206 hospitalized T2D patients who received CSII alone (CSII group, n=78) or CSII plus OADs (+OADs group, n=128) were included. The patient’s glycemic control and GV indices were derived from capillary blood glucose (BG) monitoring seven times a day. The insulin doses and time to achieve target BG (FBG<7mmolL and 2h postprandial BG<10mmol/L) were recorded.

Results: These patients were 52.5±13.0 years old, with diabetes duration of 5.8±5.9 years, and HbA1c of 9.45±2.15%. Compared with those in the CSII group, FBG (-1.39±2.40 mmol/L vs. -0.31±2.05 mmol/L), 2hBG after breakfast (-2.68±5.06 mmol/L vs. -1.16±4.26 mmol/L), 2hBG after lunch (-5.09±5.01 mmol/L vs. -2.76±5.08 mmol/L), 2hBG after supper (-3.32±4.69 mmol/L vs. -1.60±4.58 mmol/L), BG before lunch (-3.63±4.93 mmol/L vs. -2.09±3.37 mmol/L), BG before bedtime (-2.65±4.28 mmol/L vs. -1.38±4.11 mmol/L) after therapy in + OADs group decreased more obviously (all p<0.05). Moreover, +OADs group exhibited lower GV indices (SDBG: 1.89±0.55 mmol/L vs. 2.21±0.79 mmol/L; PPGE: 2.41±0.97 mmol/L vs. 2.79±1.09 mmol/L; LAGE: 5.32±1.62 mmol/L vs. 5.96±1.93 mmol/L; MAGE: 4.14±1.70 mmol/L vs. 5.08±2.81 mmol/L; and CV: 0.24±0.08 vs. 0.27±0.09, respectively) compared to CSII group (all p<0.05). Incidence of hypoglycemia was lower in +OADs group (21.1% VS 37.6%, p<0.05). The insulin doses and time to achieve target BG did not differ between the two groups.

Conclusions: OADs added to short-term CSII could further improve glycemic control and GV indices with lower incidence of hypoglycemia in T2D patients compared with CSII alone.

Disclosure

W. Jiang: None. D. Chen: None. W. Xu: None. L. Zeng: None.
1804-LB: Serum Spexin Level Is Negatively Associated with Peripheral Neuropathy and Sensory Pain in Type 2 Diabetes
Authors: LIU RUI
Published: June 2024

Background: Spexin is a novel peptide hormone and has shown anti-nociceptive effects in experimental mice. This study aimed to evaluate the association of serum spexin level with diabetic peripheral neuropathy (DPN) and related pain in a Chinese population.

Methods: We enrolled 167 type 2 diabetes mellitus (T2DM) including 56 patients without DPN (non-DPN), 67 painless DPN, and 44 painful DPN. Serum spexin was measured using ELISA. Logistic regression models were performed to analyze the independent effects of spexin on prevalence of DPN and painful DPN. In streptozotocin-induced diabetic mice, mechanical pain threshold was measured using electronic von Frey anethesiometer. Human peripheral blood mononuclear cells (PBMCs) were isolated and further stimulated with lipopolysaccharide without or with spexin. The gene expression was assayed by qPCR.

Results: Compared with non-DPN, serum spexin level decreased in painless DPN and further decreased in painful DPN. The odds of DPN was associated with low spexin level in T2DM, which was similar by age, sex, BMI, and diabetes duration, but attenuated in smokers. The odds of having pain was associated with decreased spexin level in DPN, which was similar by age, sex, smoking status, and diabetes duration, but attenuated in normal weight. Furthermore, we observed that mechanical pain threshold increased in spexin-treated diabetic mice. We also found that lipopolysaccharide treatment increased the mRNA level of TNF-α, IL-6, and MCP-1 in human PBMCs, while spexin treatment prevented this increase.

Conclusions: These results suggested that spexin might serve as a protective factor for diabetes against neuropathology and pain-related pathogenesis.

Disclosure

R. Liu: None.
1813-LB: Serum 25-hydroxyvitamin D Levels in Relation to the Risk of Diabetic Foot Ulcer in Chinese Patients with Type 2 Diabetes
Authors: ZHANG QI , LIU ZHENYU , GU YAN , ZHANG LEI , DONG YANHU
Published: June 2024

Vitamin D deficiency is not only related to bone-related diseases but also associated with cardiovascular disease, diabetes, cancer and autoimmune diseases. Previous studies show that vitamin D deficiency increases risk of macrovascular diseases and different type of infections in patients with diabetes. Data on the relationship between vitamin D and diabetic foot ulcer (DFU) is limited among Chinese patients with type 2 diabetes. In this retrospective cross-sectional study, we enrolled 5483 patients (2378 men and 3105 women aged 30 to 89 yrs) with type 2 diabetes at Qingdao Endocrine and Diabetes Hospital from Jan 1, 2017 to Oct 31, 2019. Serum 25-hydroxyvitamin D (25(OH)D) level was measured by electrochemiluminescence assay. Vitamin D deficiency was defined as Serum 25(OH)D level < 20 ng/mL according to the Endocrine Society Clinical Practice Guideline 2011. DFU was diagnosed according to guidelines on the diagnosis and treatment of foot infection in persons with diabetes (IWGDF 2019).The prevalence of DFU was 8.1% in this cohort. Patients with DFU had lower serum 25(OH)D concentration (15.33±4.51 ng/mL v.s 18.54±3.82 ng/mL, P<0.05) compared with those without DFU. The prevalence of vitamin D deficiency was higher in patient with DFU than those without the complication (84.5% v.s 70.1%, P<0.05). We did not find gender difference on the prevalence of vitamin D deficiency. In the logistical regression model, vitamin D deficiency was associated with increased risk of DFU, after adjustment of age, gender, duration of diabetes, smoking, body mass index, systolic blood pressure, fasting glucose, HbA1c, fasting C-peptide, and total cholesterol, the corresponding odds ratio (95% CI) was 1.36 (1.01-3.37) (P<0.05). Vitamin D deficiency, a common hypovitaminosis in Chinese patients with type 2 diabetes, is independently associated with increased risk for DFU. Whether vitamin D supplementation improves healing of DFU deserves further study.

Disclosure

Q. Zhang: None. Z. Liu: None. Y. Gu: None. L. Zhang: None. Y. Dong: None.

Funding

IDF Bridges Researchnet Grant (rn13-016)