bluuebunny/crossref_metadata_2025 huggingface dataset:
205-LB: HGFAC Is a ChREBP-Regulated Hepatokine That Enhances Glucose and Lipid Homeostasis
Authors: SARGSYAN ASHOT , DORIDOT LUDIVINE , HANNOU SARAH A. , TONG WENXIN , SRINIVASAN HARINI , IVISON RACHAEL , MONN RUBY , KOU HENRY H. , HALDEMAN JONATHAN , ASTAPOVA INNA , TSAI LINUS T. , HERMAN MARK A.
Published: June 2021

Carbohydrate Responsive Element-Binding Protein (ChREBP) is a carbohydrate sensing transcription factor that regulates metabolic gene programs. Genetic variants in the ChREBP locus associate with diverse metabolic traits in humans, including circulating triglycerides (TG). The transcriptional targets that mediate its pleiotropic physiological effects are poorly understood. To identify novel ChREBP-regulated hepatokines that contribute to its effects on metabolism, we integrated ChIP-seq for ChREBP in mouse liver with human GWAS data for TGs and identified Hepatocyte Growth Factor Activator (HGFAC) as a promising candidate. HGFAC is a circulating zymogen that activates Hepatocyte Growth Factor (HGF), a multifunction cytokine involved in cellular growth, motility, and morphogenesis. High fructose feeding increased circulating HGFAC by 1.8-fold (p<0.001) and this was abrogated in liver specific ChREBP KO mice. Similar increases were seen in mice fed high sucrose/high fat diet and in obese Zucker rats (2.6-fold, p<0.001). In humans, expression of hepatic ChREBP transcriptional targets associated with HGFAC expression (Pearson r= 0.66, p <0.0001), and its expression was elevated in patients with obesity and T2D (2.7-fold, p<0.001). Putative loss of function variants in HGFAC associated with hypertriglyceridemia in humans, and deletion of HGFAC in mice increased circulating TGs (1.4-fold, p<0.005), and caused glycerol and glucose intolerance despite a 40% reduction in hepatic TG content (p<0.001). RNA-seq indicated that HGFAC regulates hepatic metabolism through modulation of hepatic PPARG expression. Reciprocal effects on PPARG expression and metabolic phenotypes were observed following adenovirus HGFAC overexpression in mice. Moreover, HGF induces PPARG express 1.3-fold in HepG2 cells (p<0.0001). In conclusion, ChREBP responds to carbohydrate overnutrition and regulates systemic glucose and lipid metabolism via an HGFAC-HGF-PPARG signaling axis.

Disclosure

A. Sargsyan: None. I. Astapova: None. L. T. Tsai: None. M. A. Herman: Research Support; Self; Eli Lilly and Company. L. Doridot: Employee; Spouse/Partner; Eli Lilly and Company. S. A. Hannou: None. W. Tong: None. H. Srinivasan: None. R. Ivison: None. R. Monn: None. H. H. Kou: None. J. Haldeman: None.

Funding

American Diabetes Association (1-19-PDF-088 to A.S.)
207-LB: Simultaneous 2H/13C Assessment of Liver and Kidney Metabolic Fluxes Reveals Reciprocal Upregulation of Renal Gluconeogenesis in Hepatic PEPCK-C Knockout Mice
Authors: RAHIM MOHSIN , HASENOUR CLINTON M. , BEDNARSKI TOMASZ , HUGHEY CURTIS C. , WASSERMAN DAVID , YOUNG JAMEY
Published: June 2021

The liver is the major source of glucose production during fasting under normal physiological conditions. However, the kidney may also contribute to maintaining glucose homeostasis in certain circumstances. To test the ability of the kidney to compensate for impaired hepatic glucose production in vivo, we developed a novel stable isotope approach to simultaneously quantify hepatic and renal gluconeogenic and oxidative metabolic fluxes. Hepatic gluconeogenesis from phosphoenolpyruvate was disrupted via liver-specific knockout of cytosolic PEPCK (KO). Experiments were performed in fasted (~18hr) KO and wild-type (WT) littermate mice (n≥4, per group) fitted with jugular vein and carotid artery catheters. A multi-compartment metabolic model was used to assess fluxes using the isotopic enrichment of plasma and tissue metabolites from mice infused with 2H/13C isotopes. Hepatic gluconeogenesis and glucose production were reduced in KO mice, yet whole-body glucose production and arterial glucose were unaffected. Glucose homeostasis was maintained by a compensatory rise in renal glucose production and gluconeogenesis of 17 and 30-fold, respectively. This was consistent with a ~2-fold rise in PEPCK-C and mitochondrial PEPCK protein expression in the kidneys. Renal oxidative metabolic fluxes of KO mice increased to sustain the energetic and metabolic demands of elevated gluconeogenesis. These results show the reciprocity of the liver and kidney in maintaining glucose homeostasis by regulating gluconeogenic flux through PEPCK-C. This reciprocity creates a layer of redundancy that protects glucose homeostasis in the event that hepatic glucose production is impaired. Combining stable isotopes with mathematical modeling provides a versatile platform to assess multi-tissue metabolism in various genetic, (patho)physiological, and pharmacological settings.

Disclosure

M. Rahim: None. C. M. Hasenour: Employee; Self; Eli Lilly and Company. T. Bednarski: None. C. C. Hughey: None. D. Wasserman: None. J. Young: Consultant; Self; Pfizer Inc., Stock/Shareholder; Self; Metalytics.

Funding

National Institutes of Health (R01DK106348, U01CA235508, T32DK101003, U24DK059637)
208-LB: Peripheral CB1 Inverse Agonism Improves Metabolism in DIO Mice Independent of Hepatic FGF21
Authors: LIU JIE
Published: June 2021

Obesity is associated with an overactive endocannabinoid system, and selective blockade of CB1R in peripheral tissues, including the liver, reverses HFD-induced metabolic abnormalities by restoring normal lipid and glucose homeostasis and avoid unwanted adverse neuropsychiatric effects. The CB1R inverse agonist JD5037 has been shown equal effective with its brain-penetrant compound in reducing appetite, body weight, hepatic steatosis, and insulin resistance. Fibroblast growth factor-21 (FGF21) has emerged as a major endocrine regulator derived from the liver that reduces adiposity and hepatic steatosis and improves glucose tolerance and insulin sensitivity, with changes similar to those induced by CB1R blockade. Here we investigated whether FGF21 mediate the metabolic effects of CB1R blockade by JD5037 in DIO mice. In C57BL/6J wild-type mice, HFD caused a robust increase in hepatic Fgf21 mRNA and serum FGF21 levels, which were reversed by chronic peripheral CB1R antagonist JD5037 treatment to levels observed in STD or vehicle-treated hepatocyte-specific CB1R-/- (hCB1-/-) mice, indicating activation of CB1R in the liver is largely involved in HFD-induced “FGF21-resistant” state. In contrast, the expression of the FGF21 receptor Fgfr1 and co-receptor β-klotho (Klb) were dramatically reduced by HFD in both epididymal fat and brain tissue in wild-type mice, and these effects were reversed by JD5037 treatment. To address whether FGF21 mediated the metabolic effects of CB1R blockade, we repeated JD5037 treatment in liver-specific FGF21-/- (hFGF21-/-) mice. Surprisingly, JD5037 treatment was almost equally effective in both HFD-fed wild-type and in hFGF21-/- mice in reducing body weight and hepatic steatosis, attenuating hyperinsulinemia and hyperleptinemia. The current data suggest that peripheral CB1R blockade by inverse agonist in obese mice improves insulin sensitivity and energy expenditure independently of hepatic FGF21.

Disclosure

J. Liu: None.

Funding

National Institutes of Health
209-LB: RNA-Seq Analysis of Liver from Diabetic and NASH Model Mouse Treated with Streptozotocin, High-Fat Diet
Authors: BUI LINH P. , SAKAKIBARA YUKI , TANAKA RYUTO , PIGNEY ELIZABETH H. , HASHIGUCHI TAISHI
Published: June 2021

Introduction: NASH is a chronic liver disease often associated with type 2 diabetes. It sometimes progresses to more serious conditions such as liver fibrosis and hepatocellular carcinoma (HCC). Therapeutic agents for NASH have not yet been developed, and an animal model with high clinical correlation is required. The STAM mouse is a NASH model mouse with a background of type 2 diabetes. This mouse model shows the same pathological progression as human NASH patients, and has been used for the evaluation of many drug candidates, as well as basic research. However the gene profile, including mutations, has not been elucidated in this model. In this study, we analyzed the RNA-seq data of STAM mice at each pathological stage and examined the clinical correlation at the gene level.

Methods: NASH was induced in male mice by a single injection of streptozotocin solution 2 days after birth and feeding with high fat diet after 4 weeks of age. The mice were sacrificed and livers collected from each disease phase. RNA-Seq libraries were prepared by NEB NEXT Directional Ultra RNA Library Prep Kit (Illumina). The libraries were sequenced on Novaseq (Illumina), and the reads were aligned to mouse genome references using HISAT2. RNA-seq data analysis Sequence reads (150-bp paired read) were aligned to the mouse reference genome (GRCm38/mm10) with HISAT2 (version: 2.1.0) with default parameters.

Results: First, the gene expression of the canonical pathway in NASH progression from steatosis to hepatocellular carcinoma was analyzed. Increased expression was observed in CCL2, TLR4, HSP47, αSMA, c-Myc, and cyclin D1. Since it has been reported that genetic traits are involved in the development of NASH-HCC, we next analyzed the genetic mutations in the STAM mice. The number of individuals showing mutations in Mtor, involved in Insulin signaling, increases as the disease progresses, especially in the HCC phase.

Conclusion: These results indicated a clinical correlation of gene profiles in the STAM mouse.

Disclosure

L. P. Bui: Employee; Self; SMC Laboratories Inc. Y. Sakakibara: Employee; Self; SMC. R. Tanaka: Employee; Self; SMC Laboratories Inc. E. H. Pigney: Employee; Self; SMC Laboratories, Inc. T. Hashiguchi: Employee; Self; SMC laboratories, Inc.
213-LB: Mechanisms of Metabolic Cross Talk between Mitochondrial Pyruvate Carrier Inhibition and Branched-Chain Amino Acid Catabolism in Hepatocytes
Authors: FERGUSON DANIEL , YIEW NICOLE K.H. , MCCOMMIS KYLE S. , COLCA JERRY R. , FINCK BRIAN N.
Published: June 2021

The mitochondrial pyruvate carrier (MPC) has emerged as a therapeutic target for treating insulin resistance, type 2 diabetes, and nonalcoholic steatohepatitis (NASH). However, the molecular mechanisms by which MPC inhibition leads to metabolic improvements are incompletely understood. We evaluated whether MPC inhibitors might correct impairments in branched chain amino acid (BCAA) catabolism, which are predictive of developing diabetes and NASH. BCAA concentrations were assessed in plasma collected in EMMINENCE (NCT02784444), a randomized, placebo-controlled trial of the MPC inhibitor MSDC-0602K in people with NASH. MSDC-0602K treatment, which led to marked improvements in insulin sensitivity and diabetes endpoints, decreased plasma concentrations of BCAAs compared to baseline while placebo had no effect. The rate-limiting enzyme in BCAA catabolism is the mitochondrial branched chain ketoacid dehydrogenase (BCKDH). BCKDH activity is suppressed by phosphorylation mediated by a kinase (BDK) and activated by the phosphatase (PPM1K). In Huh7 or HepG2 cells, MPC inhibitors markedly reduced BCKDH phosphorylation, suggesting increased BCKDH activity. Chemical inhibition or siRNA-mediated silencing of BDK had no effect on suppression of BCKDH phosphorylation by MPC inhibitors. In contrast, PPM1K knockdown prevented the effects of MPC inhibition on phospho-BCKDH. Lastly, we quantified BCKDH phosphorylation in liver of wild-type and hepatocyte-specific MPC2 knockout (LS-Mpc2-/-) mice after 20 weeks of high fat diet. LS-Mpc2-/- mice exhibited reduced phosphorylation of BCKDH compared to wild-type mice. Lean LS-Mpc2-/- mice also exhibited reduced plasma BCAA concentrations after an overnight fast. These data demonstrate novel cross talk between mitochondrial pyruvate and BCAA metabolism and suggest that MPC inhibition leads to lower plasma BCAA concentrations and BCKDH phosphorylation via the phosphatase PPM1K.

Disclosure

D. Ferguson: None. N. K. H. Yiew: None. K. S. Mccommis: None. J. R. Colca: Board Member; Self; Metabolic Solutions Development Company, LLC, Employee; Self; Cirius Therapeutics. B. N. Finck: Advisory Panel; Self; Cirius Therapeutics, Stock/Shareholder; Self; Cirius Therapeutics.

Funding

National Institutes of Health (R01DK104735, T32DK007120)
217-LB: YH34160, a Novel Long-Acting GDF15 Fusion Protein, Elicits Potent and Sustained Body Weight Loss in Obese Animal Models
Authors: LIM SEYOUNG , YANG JIEUN , KIM DO-HOON , JU MI KYEONG , KIM SUKYUNG , PARK YOUNG BONG , SIM BO RA , KIM JUNHWAN , KIM JONG GYUN , OH SE-WOONG
Published: June 2021

Growth differentiation factor 15 (GDF15) is a multifunctional protein associated with energy homeostasis and body weight regulation. GDF15 has emerged as an attractive therapeutic target to treat obesity-related metabolic disorders. GDF15 reduces food intake with unique mode of action via its receptor GDNF family receptor α-like (GFRAL) and the co-receptor RET. YH34160 is an Fc fusion GDF15 variant engineered to have extended half-life and improved binding affinity to GDF15 receptors (GFRAL/RET). YH34160 exhibited superior in vitro efficacy over Fc fusion protein comprising wild-type GDF15 in GFRAL/RET overexpressing cells. Based on rodent and monkey pharmacokinetic (PK) data, YH34160 is expected to have an optimal PK profile for once-weekly dosing in human. In addition, YH34160 exhibited a potent and sustained weight-lowering effect in the obese mice models. After single subcutaneous injection in diet-induced obese (DIO) mice, YH34160-treated groups showed sustained and dose-dependent body weight reduction. Following 8-week repeat dose study in DIO mice, YH34160-treated groups induced more potent and sustained body weight loss compared to the group of long-acting glucagon like peptide-1 receptor agonist (GLP-1RA). Significant body weight reduction and improved lipid profiles by YH34160 was also proved in leptin-deficient (ob/ob) mice compared to GLP-1RA. Furthermore, YH34160 in combination with a GLP-1RA demonstrated a complementary effect on body weight loss compared to that of each single agent treatment. These findings indicate that YH34160 would be a promising therapeutic candidate for the treatment of human obesity.

Disclosure

S. Lim: Employee; Self; Yuhan Corporation. S. Oh: Employee; Self; Yuhan Corporation, Stock/Shareholder; Self; Yuhan Corporation. J. Yang: None. D. Kim: None. M. Ju: None. S. Kim: Employee; Self; Yuhan Corporation. Y. Park: Employee; Self; Yuhan Corporation. B. Sim: Employee; Self; Yuhan Corporation. J. Kim: Employee; Self; Yuhan Corporation. J. Kim: None.
217-OR: Glycemic Outcomes by Ethnicity in Adults with Type 1 Diabetes Using Control-IQ Technology: Early Results from the CLIO Study
Authors: HABIF STEPHANIE , SINGH HARSIMRAN , MUELLER LARS , MANNING MICHELLE L. , WHITE KIRSTIN N. , LEAS SCOTT A. , SPENCER ELIAH S. ARONOFF , DOKKEN BETSY , SPENCER ELIAH ARONOFF
Published: June 2021

Incidence of type 1 diabetes (T1D) is increasing in different ethnic groups. Given the rapid evolution of insulin delivery systems, it is important to evaluate their performance in diverse populations. The Control-IQ Observational (CLIO) Study is an IRB-approved, single-arm, longitudinal study evaluating real-world use of the Control-IQ system in people with T1D (PWT1D) who had been prescribed the Tandem t:slim X2 insulin pump with Control-IQ technology. We evaluated relationships between glycemic metrics, diabetes-specific items, and demographic variables at baseline and 3 months after study start for adult participants who had uploaded at least 21 days (21d) of Control-IQ feature usage data to Tandem’s t:connect® web application and had ≥75% CGM use during this time. Impact of baseline factors on glycemic outcomes were analyzed using generalized linear models. In all, 1094 PWT1D (963 Caucasians, 72 Hispanics, 45 African Americans, 25 Asians) were included in the analysis. African Americans had the highest HbA1c at baseline (8.1%) in contrast to the Caucasian majority (7.3%). Glucose Management Indicator (GMI) at 21d reflected significant glycemic improvement across all ethnic groups with Asians showing the lowest GMI (6.77%) followed by Caucasians (6.98%). At 21d, the sensor time in range (TIR) (median) of African Americans (62.7%, IQR=53.4-74.7) was significantly lower than for Caucasians (75.1%, IQR=70.3-81.0) while controlling for age, gender, reported exercise, annual income, and prior therapy (p=0.004). Baseline HbA1c was the key factor predicting TIR at 21d followed by exercise, annual income, and multiple daily injections (prior therapy). We identified disparities in glycemic outcomes across socioeconomic and demographic groups at baseline that remained after initiating an automated insulin delivery system. Nevertheless Control-IQ technology significantly improved glycemic outcomes for all ethnic groups.

Disclosure

S. Habif: Employee; Self; Tandem Diabetes Care. H. Singh: Employee; Self; Tandem Diabetes Care. L. Mueller: Research Support; Self; Dexcom, Inc., Tandem Diabetes Care. M. L. Manning: Employee; Self; Tandem Diabetes Care. K. N. White: Employee; Self; Tandem Diabetes Care. S. A. Leas: Employee; Self; Tandem Diabetes Care. E. S. Aronoff spencer: None. B. Dokken: Employee; Self; Tandem Diabetes Care, Stock/Shareholder; Self; Tandem Diabetes Care. E. Aronoff spencer: None.
218-LB: Age, Sex, and Fat Mass Affects Erythropoietin Metabolic Response in Mice
Authors: ROGERS HEATHER , NOGUCHI CONSTANCE T.
Published: June 2021

Erythropoietin (EPO) is required for erythrocyte production. However, EPO receptor (EpoR) extends beyond erythroid tissue and ΔEpoR mice with EpoR restricted to hematopoietic tissue show an increase in fat mass. At 3 months of age, ΔEpoR mice show no difference in body weight compared with wild type (WT, C57BL/6) mice. By 6 months of age, male body weights of ΔEpoR mice are greater than WT mice, and at 8+ months body weights of male and female ΔEpoR mice are greater than their WT counterparts. To assess EPO activity on glucose homeostasis and fat mass, mice were fed a high fat diet (HFD, 60% kCal fat) and treated with EPO (3000U/kg 3X per week) or saline for 3 weeks at age 3, 6, and 8+ months. EPO increased hematocrit in all mice. EPO treatment in male WT mice reduces weight and fat mass at 6 and 8+ months of age, when their fat mass is 35% or greater with saline treatment. Female WT mice treated with EPO do not show significantly less weight or fat mass at any age. EPO treatment does not affect weight or fat mass in ΔEpoR mice. With HFD feeding and EPO treatment in 3 month old mice, body weights are not different between WT and ΔEpoR mice although fat mass is significantly higher in ΔEpoR mice. At 6 months, body weight and fat mass in males are greater in ΔEpoR than WT, while ΔEpoR females show no difference in body weight but significantly more fat mass compared with WT females. In the older mice (8+ months old), both sexes of ΔEpoR mice are significantly heavier and fatter than WT mice. EPO treatment improves glucose tolerance in female ΔEpoR mice at 3 and 6 months but not at 8+months, whereas male ΔEpoR mice only showed improvement at 3 months, not at 6 and 8+months. In male and female WT mice, EPO improves glucose metabolism at 3 and 6 months, and to a lesser extent at 8+ months with greater improvement in mice with <35% fat mass. These data show that EPO regulates metabolism in a sex and age dependent manner mediated via EpoR expression in non-hematopoietic tissue and is influenced by level of fat mass.

Disclosure

H. Rogers: None. C. T. Noguchi: None.
22-OR: Exploring the Association between Physical Activity Levels and Sedentary Behaviors with Risk of T2DM from Childhood to Adolescence: A Causal Inference Analysis
Authors: HARNOIS-LEBLANC SOREN , VAN HULST ANDRAEA , BARNETT TRACIE A. , MATHIEU MARIE-EVE , PARADIS GILLES , SYLVESTRE MARIE-PIERRE , HENDERSON MÉLANIE , GROUP QUALITY RESEARCH
Published: June 2021

Background and Objective: Causal inference methods were developed to emulate repeated randomized trials in observational studies, notably by controlling for time-varying confounders. Using these methods, we examined the complex relationship between physical activity, sedentary behaviors and T2DM accounting for interrelations between time-varying lifestyle habits and their reciprocal effects on T2DM across childhood.

Methods: We used longitudinal marginal structural models (with inverse probability of treatment and censoring weighting) on prospective data of Caucasian children with a parental history of obesity (QUALITY Cohort) evaluated at 8-10 years (n=630), 10-12 years (n=564) and 15-17 years (n=377). At each visit, participants underwent an OGTT (1.75g/kg glucose, max 75g). ISI-Matsuda estimated insulin sensitivity. Area under the curve of glucose to insulin estimated 1st (0-30 min) and 2nd phase (0-120 min) insulin secretion. ADA cut points determine IFG, IGT and T2DM. Moderate to vigorous physical activity (MVPA) and sedentary behaviors were assessed with 7-day accelerometry and leisure screen time by questionnaire. Confounders included age, sex, BMI z-score, pubertal stage, diet quality index-international, energy intake, sleep, fitness, parental BMI, and income.

Results: Every additional 10-min of daily MVPA across 8-10 to 15-17 years was associated with a 5.4% (95% CI: -8.8; -2.0) reduction in 2nd-phase insulin secretion at 15-17 years. Every additional 1-h of daily screen time across 8-10 to 15-17 years was associated with an 8.4% (95% CI: -14.1; -2.7) reduction in insulin sensitivity and a 6.4% (95% CI: 0.3; 12.5) and 8.1% (95% CI: 1.5; 14.7) increase in 1st- and 2nd-phase insulin secretion at 15-17 years. No associations were observed with IFG/IGT/T2DM.

Conclusion: Even small increases in MVPA or slight reductions in screen time in childhood/adolescence may play a role in T2DM prevention.

Disclosure

S. Harnois-leblanc: None. A. Van hulst: None. T. A. Barnett: None. M. Mathieu: Research Support; Self; CAPSANA, FitSpirit, Research Support; Spouse/Partner; Caboma, Medicus. G. Paradis: None. M. Sylvestre: None. M. Henderson: None. Quality research group: n/a.

Funding

Canadian Institutes of Health Research (OHF-69442, NMD-94067, MOP-97853, MOP-119512); Heart and Stroke Foundation of Canada (PG-040291); Fonds de Recherche du Québec - Santé
222-OR: High Glucose Level Increases Expression of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Receptors
Authors: NANDULA SESHAGIRI RAO , JANAPALA RAJESH NAIDU , SEN SABYASACHI
Published: June 2021

Introduction: Coronavirus disease 2019 (COVID-19) is a highly contagious disease caused by a novel coronavirus, SARS-CoV-2. The SARS-CoV-2 virus infects the host human cells through its surface receptors human angiotensin-converting enzyme 2 (ACE2) and transmembrane protease, serine 2 (TMPRSS2). This study aims to investigate the effects of high glucose on the expression of ACE2 and TMPRSS2 receptors using macrophage (CD14+ve cells) as a biomarker in vivo and human endothelial cells in vitro.

Methods: Mononuclear cells were isolated by Ficoll density centrifuge method from whole blood. CD14 cells were isolated from MNCs by MACS kit. The migratory capacity of CD14 cells was evaluated using the CytoSelect Migration Assay kit. CFU-Hill colony formation assay was also done on MNCs. In vitro studies using HUVEC were done by culturing the cells in normal glucose (NG, 5.5mmol/L) or high glucose (HG, 20 mmol/L), followed by mRNA assays at day 3 and 7.

Results: All the COVID patients had high glucose levels (>300 mg/dl). The migratory function of CD14 cells show moderately increased migration compared to similar hematopoietic cells from nondiabetic COVID negative patients. In general, CD14 cells showed low expression of ACE2 and/or TMPRSS2 in all samples. For our in-vitro experiments using cultured HUVEC mRNA expression of ACE2 and/or TMPRSS2 receptors were higher in HG compared to NG at day 7. No expression was observed at day 3 either in NG or HG. An elevated gene expression of inflammatory marker, IL-6 and apoptosis marker, P53 were observed in HG at both days 3 and 7.

Conclusions: A low expression of SARS-CoV-2 receptors were observed on CD14 macrophage cells from patients which may indicate poor recognition of the virus particle by CD14 cells. Higher expression of the SARS-CoV-2 receptors were noted when HUVEC cells were cultured in HG for 7 days.

Conclusion: Longer exposure of human endothelial cells in high glucose condition increase the SARS-CoV-2 receptor expression.

Disclosure

S. Nandula: None. R. Janapala: None. S. Sen: None.

Funding

Clinical and Translational Science Institute at Children’s National
230-LB: Differential Roles of Beta-Cell IP3R and RyR ER Ca2+ Channels in Tunicamycin-Induced Disruption of Beta-Cell Ca2+ Homeostasis
Authors: ZHANG IRINA , PAREKH VISHAL S. , LEON JUAN J. , SATIN LESLIE S.
Published: June 2021

Pancreatic beta cells maintain glucose homeostasis by secreting insulin following a rise in plasma glucose. Insulin secretion is pulsatile, which is brought about because of oscillations in the concentrations of beta-cell cytosolic Ca2+. The endoplasmic reticulum (ER) helps to regulate the cytosolic Ca2+ level, thereby playing a role in Ca2+-induced insulin release. ER stress, triggered by the accumulation of unfolded proteins in the ER, can lead to the ER Ca2+ depletion, which in turn can contribute to beta-cell deterioration and an increased risk of type-2 diabetes. We sought to determine the effects of tunicamycin (TM)-induced ER stress on ER Ca2+ channels, inositol 1,4,5-triphosphate (IP3) receptors (IP3Rs) and ryanodine receptors (RyRs), and subsequent alterations in beta-cell Ca2+ homeostasis that result from these alterations. To determine the roles of these receptors in TM-induced beta-cell dysfunction, we treated mouse pancreatic islets with the RyR1 inhibitor dantrolene (Dan) or the IP3R inhibitor xestospongin C (XeC) along with TM. Beta cells treated with TM exhibited altered cytosolic and mitochondrial Ca2+ when in sub-threshold glucose compared to vehicle controls. As TM treatment also reduced ER Ca2+, this raised the possibility that the mitochondrial and cytosolic Ca2+ oscillations seen in stressed cells resulted from increased ER Ca2+ efflux mediated by RyRs and/or IP3Rs. We found that TM-induced ER Ca2+ depletion, as well as cytosolic and mitochondrial Ca2+ oscillations were inhibited by co-treatment with Dan, whereas the inclusion of XeC had little or no effect. Taken together, these results suggest that RyRs, and more specifically RyR1 plays a critical role in mediating the disturbed cellular Ca2+ homeostasis seen in response to the induction of ER stress.

Disclosure

I. Zhang: None. V. S. Parekh: None. J. J. Leon: None. L. S. Satin: None.

Funding

National Institutes of Health (R01DK46409); University of Michigan; JDRF (2-SRA-2018-539-A-B)
240-OR: Mortality, MACE, and Diabetic Complications in Men with Hypogonadism and Type 2 Diabetes (T2DM) Receiving Long-Term Treatment with Testosterone Undecanoate Injections (TU): An Update of 12-Year Real-World Data
Authors: HAIDER KARIM S. , HAIDER AHMAD , SAAD FARID
Published: June 2021

Background: Men with hypogonadism are at increased risk of MACE and mortality. Studies in men with T2DM show that testosterone therapy (TTh) reduces both MACE and mortality.

Methods: Of 361 men with hypogonadism and T2DM, 183 received testosterone undecanoate injections (TU) 1000 mg/12 weeks (T-group), 178 opted against treatment (CTRL). MACE, mortality, and diabetic complications were recorded and compared between groups.

Results: Mean baseline age in the T-group and CTRL was 60.7±5.5 and 63.0±4.9 years. Mean follow-up in T-group vs. CTRL was 8.2 and 9.2 years. 70 patients (38.3%) in the T-group and 70 (39.3%) in CTRL had a history of cardiovascular disease (myocardial infarction MI, stroke, or coronary artery disease diagnosis) (p=0.8341). Baseline smoking prevalence was 41.0% (75 men) in the T-group and 38.2% (68 men) in CTRL (p=0.5161). The T-group had significantly worse baseline risk factor profile than CTRL: BMI (36.5±4.5 vs. 33.4±5.3 kg/m2), systolic blood pressure (163.0±13.5 vs. 145.6±14.6 mmHg), LDL (4.7±0.9 vs. 4.1±1.4 mmol/L), HbA1c 9.4±1.4 vs. 7.8±0.7% (p<0.0001 for all). Mortality: during the entire observation period, 15 patients (8.2%) died in the T-group vs. 61 (34.3%) in CTRL (p<0.0001). Major adverse cardiovascular events (MACE): in the T-group, there were no cases of MI or stroke. In CTRL, there were 56 cases of MI (31.5%) and 56 cases of stroke (31.5%). 35 patients (19.7%) suffered a MI and a stroke. Diabetic complications: in the T-group vs. CTRL, the incidence of retinopathy was 6 (3.3%) vs. 30 (16.9%) (p<0.0001), nephropathy 1 (0.01%) vs. 5 (2.8%) (p<0.05), polyneuropathy 11 (6.0%) vs. 97 (54.5%) (p<0.0001), diabetic foot syndrome 0 (0%) vs. 10.1% (p<0.0001).

Conclusions: Long-term treatment with TU in men with hypogonadism and T2DM significantly reduces mortality, compared to untreated controls.

Disclosure

K. S. Haider: Other Relationship; Self; Bayer AG. A. Haider: Other Relationship; Self; Bayer AG. F. Saad: Consultant; Self; Bayer AG, Stock/Shareholder; Self; AbbVie Inc., Bayer AG, Novo Nordisk.

Funding

Bayer AG
26-OR: Meta-analyses of Genome-Wide Association Studies for Proinsulin Provide Insight into Glycemic Trait Dysregulation
Authors: BROADAWAY K. ALAINE , YIN XIANYONOG , WILLIAMSON ALICE , WILSON EMMA , INVESTIGATORS MAGIC
Published: June 2021

Proinsulin, a prohormone precursor to insulin, is synthesized and processed before secretion from pancreatic islet beta cells. Increased plasma proinsulin levels relative to insulin levels may predict insulin resistance and type 2 diabetes (T2D), and the genes involved in proinsulin processing are incompletely understood. Previous genome-wide association studies (GWAS) have identified 13 loci associated with proinsulin levels. To identify additional loci, we conducted a meta-analysis of GWAS results of fasting proinsulin from 16 European-ancestry studies of 45,826 individuals. Each cohort analysis controlled for age, sex, population structure, fasting insulin, and BMI. We identified 35 independent association signals at 30 loci (1 Mb, p<5E-8), including 22 signals not reported previously for proinsulin, 11 of which also were not reported in four recent large GWAS meta-analyses for T2D or four glycemic traits. We identified 14 additional nominally significant proinsulin signals (P<5E-5) that colocalized with at least one known glycemic trait signal. Using Bayesian colocalization methods and expression quantitative trait locus (eQTL) data from the InsPIRE islet eQTL consortium, we identified at least one gene colocalized with 17 proinsulin signals. One set of new loci may influence proinsulin processing, including signals near PCSK2, DLC1, and a low-frequency, missense variant at ELAPOR1, a transmembrane protein localized in the plasma membrane-late endosome-lysosome compartments. Another subset of new loci may influence proinsulin and insulin secretion, including TLE1, BCL11A, and RNF6. We further find a proinsulin-increasing allele at the SIX3 locus that has previously only been associated with glucose and T2D in East Asians, demonstrating that the glycemic trait associations at SIX3 are not population-specific. Our results provide additional insight into the biology underlying glycemic trait dysregulation and etiology of T2D.

Disclosure

K. Broadaway: None. X. Yin: None. A. Williamson: None. E. Wilson: None. Magic investigators: n/a.
273-OR: Association of an Integrated Component of Maternal Glycemic Regulation in Pregnancy with Epigenome-Wide Cord Blood DNA Methylation
Authors: JUVINAO-QUINTERO DIANA L. , CARDENAS ANDRES , PERRON PATRICE , BOUCHARD LUIGI , LUTZ SHARON , HIVERT MARIE-FRANCE
Published: June 2021

Background: Abnormal maternal glucose regulation in pregnancy has been associated with future cardiometabolic diseases in the offspring. Previous studies suggest that fetal programming is due to modulation of DNA methylation (DNAm), but they have been limited in their maternal glycemic characterization.

Methods: In Gen3G, a prospective prebirth cohort, we investigated associations between an integrated component of maternal glucose regulation in pregnancy and cord blood DNAm levels in an epigenome-wide analysis at 719,558 CpG sites among 430 mother-child pairs. We used a principal component (PC) analysis to create a linear combination of multiple glucose and insulin values measured during a second trimester (24-30 weeks) oral glucose tolerance test (OGTT). We adjusted linear regression models for maternal age, parity, smoking during pregnancy, gestational week at OGTT, child sex, gestational age at delivery, and the estimated proportion of cord blood cells.

Results: The first component (PC1) explained 47% of the total variation in maternal glucose and insulin values from the OGTT and was associated with methylation at cg26974062 (TXNIP) at genome-wide level significance (Bonferroni corrected P<6.95x10-8). Two additional CpG sites were suggestively associated with PC1 (P<1.0x10-6). For these three CpG sites, associations of cord blood DNAm were stronger with PC1 compared to associations with the individual glucose or insulin values.

Conclusions: Among adults, blood DNAm at TXNIP has been previously associated with type 2 diabetes. Our findings suggest that an altered prenatal glucose metabolism may program dysregulation of DNAm at TXNIP across the life-course.

Disclosure

D. L. Juvinao-quintero: None. A. Cardenas: None. P. Perron: None. L. Bouchard: None. S. Lutz: None. M. Hivert: None.

Funding

American Diabetes Association/Pathway to Stop Diabetes (1-15-ACE-26 to M-F.H.)
281-OR: Endothelial Cell Cd36 Regulates Systemic Glucose and Lipid Metabolism
Authors: GOEDEKE LEIGH , SON NI-HUIPING , LAMOIA TRACI E. , NASIRI ALI , KAHN MARIO , ZHANG XIAN-MAN , CLINE GARY , GOLDBERG IRA J. , SHULMAN GERALD I.
Published: June 2021

The transmembrane protein, cluster of differentiation 36 (CD36), facilitates tissue fatty acid uptake and is highly expressed in a variety of different cell types, including endothelial cells (ECs). Loss of EC Cd36 reduces parenchymal long-chain fatty acid uptake and improves whole-body glucose tolerance and insulin sensitivity; however, the mechanisms by which this occurs remain unclear. Here, we report that EC-specific deletion of Cd36 in chow-fed male mice (EC-Cd36-/-) leads to significant reductions in whole-body fat utilization during fasting, subsequently increasing plasma non-esterified fatty acid levels by 30% (P<0.05 vs. Cd36fl/fl). We performed hyperinsulinemic-euglycemic clamp studies, using [13C6]glucose as the infusate, and found that loss of EC Cd36 improved whole-body insulin sensitivity by 15% (P<0.05 vs. Cd36fl/fl) due to a 40-50% increase in insulin-stimulated glucose uptake in heart and brown adipose tissue (both P<0.05 vs. Cd36fl/fl). Consistent with enhanced rates of glucose transport, EC-Cd36-/- mice displayed a significant 20% increase in relative rates of myocardial pyruvate dehydrogenase oxidation to citrate synthase flux (VPDH/VCS) compared to Cd36fl/fl controls; in contrast, mitochondrial VPDH/VCS was unaffected in liver and skeletal muscle. Interestingly, improvements in whole-body insulin sensitivity due to loss of EC Cd36 was also associated with 20% reductions in fasting plasma glucose concentrations and hepatic glucose production (both P<0.05 vs. Cd36fl/fl), which could be attributed to a significant 20% decrease in hepatic acetyl-CoA content.

Conclusion: Taken together, these results demonstrate a key role for EC Cd36 in regulating parenchymal fuel selection and hepatic glucose production and provide insight into the mechanisms by which EC Cd36 controls systemic glucose and lipid metabolism.

Disclosure

L. Goedeke: None. N. Son: None. T. E. Lamoia: None. A. Nasiri: Employee; Spouse/Partner; Medtronic. M. Kahn: None. X. Zhang: None. G. Cline: None. I. J. Goldberg: Advisory Panel; Self; Akcea Therapeutics, Arrowhead Pharmaceuticals, Inc., Consultant; Self; Esperion. G. I. Shulman: Consultant; Self; 89bio, Inc., BridgeBio, Ionis Pharmaceuticals, Maze Therapeutics, Novo Nordisk, Other Relationship; Self; AstraZeneca, Esperion Therapeutics, Inc, Generian Pharmaceuticals, Inc., Gilead Sciences, Inc., iMetabolic Biopharma Corporation, Janssen Research & Development, LLC, Merck & Co., Inc., The Liver Company.

Funding

National Institutes of Health (HL150234, R01DK113984, R01DK045735)
282-OR: The Effect of Glucagon on Rates of Hepatic Mitochondrial Oxidation and Pyruvate Carboxylase Flux in Man Assessed by Positional Isotopomer NMR Tracer Analysis (PINTA)
Authors: PETERSEN KITT , SHULMAN GERALD I.
Published: June 2021

Dual GLP-1/glucagon agonists are now in clinical trials for the treatment of T2D and NASH. In addition to promoting further reduction in food intake on top of GLP-1, the glucagon component of these dual agonists may also promote increased rates of hepatic mitochondrial fat oxidation. In order to investigate this possibility we assessed the glucagon-specific effects of a dual agonist on rates of hepatic mitochondrial oxidation (VCS) and pyruvate carboxylase flux (VPC) in humans by infusing glucagon to achieve a physiological increase in plasma glucagon concentrations in combination with a novel 13C PINTA method to assess rates of hepatic VCS and VPC in 15 healthy volunteers using a paired study design. Following an overnight fast a 3-h IV infusion of [3-13C]lactate (4.3 μmol/Kg-min) and [1,2,3,4,5,6,6-2H7]glucose (0.22 μmol/Kg-min) was begun and during the last 2 hours glucagon (GLG) was co-infused [6 ng/(Kg-min)] or no GLG (CON). The GLG infusion resulted in a ~2.4 fold increase in plasma GLG conc. (from 75±11 to 183±20 pg/mL; P<0.0001), which was associated with an ~20% increase in both plasma C-peptide (from 1.89±0.17 to 2.30±0.26 ng/mL; P=0.02) and plasma insulin conc. (from 9.9±2.0 to 12.0±2.4 μU/mL; P=0.06). Plasma glucose conc. increased from 4.90±0.16 to 5.64±0.19 mmol/L (P=0.0001) which was associated with a tendency for increased rates of glucose production (CON:1042±123 vs. GLG:1148±122 μmol/min; p=0.086) despite no change in rates of VPC flux (CON: 403±69 vs. GLG: 373±55 μmol/min; p=NS). In contrast, this physiological increase in plasma GLG concentrations caused an 85% increase in rates of hepatic VCS (P<0.05).

Conclusion: Taken together these studies demonstrate that a physiological increase in plasma glucagon promotes increased rates of hepatic mitochondrial oxidation in humans, which may provide additional benefits to the anorexic effects of dual GLP-1/glucagon agonists to reduce hepatic steatosis.

Disclosure

K. Petersen: Advisory Panel; Spouse/Partner; AstraZeneca, iMetabolic Biopharma Corporation, Janssen Research & Development, LLC, Merck & Co., Inc., Consultant; Spouse/Partner; Aegerion Pharmaceuticals Inc., Novo Nordisk, Research Support; Self; Gilead Sciences, Inc., Merck & Co., Inc. G. I. Shulman: Consultant; Self; 89bio, Inc., BridgeBio, Ionis Pharmaceuticals, Maze Therapeutics, Novo Nordisk, Other Relationship; Self; AstraZeneca, Esperion Therapeutics, Inc, Generian Pharmaceuticals, Inc., Gilead Sciences, Inc., iMetabolic Biopharma Corporation, Janssen Research & Development, LLC, Merck & Co., Inc., The Liver Company.

Funding

Merck & Co., Inc. (MISP583402); National Institutes of Health (R01DK113984)
288-OR: Role of Endoplasmic Reticulum (ER) Calcium in ß-Cell Senescence and Type 1 Diabetes Pathophysiology
Authors: WEAVER STACI A. , KONO TATSUYOSHI , SYED FAROOQ , BONE ROBERT N. , EVANS-MOLINA CARMELLA
Published: June 2021

Type 1 diabetes (T1D) results from immune-mediated destruction of pancreatic β cells. Recent data suggest that activation of senescence and acquisition of a senescence-associated secretory phenotype (SASP) by β cells may contribute to T1D pathogenesis; however, the molecular mechanisms responsible for this phenotype are not well understood. Our previous work has linked loss of β cell ER Ca2+ with diabetes pathophysiology and demonstrated accelerated onset of hyperglycemia in non-obese diabetic (NOD) mice with haploinsufficiency of the SERCA2 pump (NOD-S2+/-). Therefore, we hypothesized that loss of ER Ca2+ via reduced SERCA2 activity may drive β cell senescence, SASP, mitochondrial dysfunction and T1D development. To test this hypothesis, SERCA2 KO INS-1 β cells (S2KO) and islets from NOD-S2+/- mice were assessed for senescence associated β-galactosidase staining (SA-β-gal), mRNA expression of senescence markers cdkn1a and cdkn2a, mitochondrial membrane potential and function (TMRM, Seahorse) as well as mitochondrial DNA copy number. S2KO β cells displayed increased SA-β-gal staining as well as increased mitochondrial coupling efficiency and baseline mitochondrial copy number compared to WT β cells, suggesting a senescence phenotype, and altered mitochondrial function. Pancreatic islets isolated from NOD-S2+/- mice show increased mRNA expression of the senescence marker cdkn2a at 12wks compared to age matched control mice (p<0.05), whereas cdkn1a remained unchanged across all timepoints tested. Our results suggest that loss of SERCA2 and reduced ER Ca2+ alters β cell mitochondrial function and is associated with features of senescence. Future studies will test whether SERCA2 activation and/or senolytic/senomorphic drugs are able to prevent or delay diabetes onset in NOD-S2+/- mice. This study has the potential to inform new paradigms of T1D prevention and therapy with the overall goal of improving β cell health during autoimmunity.

Disclosure

S. A. Weaver: None. T. Kono: None. F. Syed: None. R. N. Bone: None. C. Evans-molina: Advisory Panel; Self; Provention Bio, Inc., Consultant; Self; Dompe, Other Relationship; Self; Bristol-Myers Squibb Company, Nimbus Pharmaceuticals, Pfizer Inc.

Funding

Indiana Clinical and Translational Sciences Institute (UL1TR002529)
30-OR: Identification of LRG1 as an Insulin Sensitizing Adipokine
Authors: CHOI CHAN HEE J. , BARR WILL , KOENEN MASCHA , LIN ZERAN , SZWED SARAH , COHEN PAUL
Published: June 2021

Adipocytes play a central role in obesity, type 2 diabetes, and metabolic disease. White adipocytes store excess energy, and brown adipocytes dissipate chemical energy into heat. In addition to these bioenergetics functions, adipocytes also have important endocrine properties. Bioinformatic analyses suggest that adipocytes may secrete over 1,000 unique polypeptides, the vast majority of which remain uncharacterized. We employed bio-orthogonal non-canonical amino acid tagging (BONCAT) along with mass spectrometry to comprehensively characterize the secreted proteome of murine subcutaneous and visceral white adipocytes and interscapular brown adipocytes. We identified more than 700 unique proteins, with approximately 300 showing fat cell type specific enrichment. We here describe a novel role for leucine-rich alpha-2 glycoprotein 1 (LRG1), a secreted protein expressed across all types of adipose tissues. Plasma LRG1 levels were increased in aged and diet-induced obese (DIO) mice. Longitudinal overexpression of LRG1, using an adeno-associated virus (AAV) with tropism for adipose tissue, led to significantly improved glucose and insulin tolerance in DIO mice, despite equivalent body weights. AAV-mediated overexpression of LRG1 in the db/db model of type 2 diabetes resulted in accelerated weight gain due to increased white fat mass, but improved insulin tolerance and a delayed diabetic phenotype. LRG1 overexpressing mice had markedly reduced macrophage accumulation in white adipose tissues, and LRG1 significantly reduced pro-inflammatory gene expression. Taken together, these data suggest LRG1 acts as an insulin sensitizer by promoting healthier lipid storage with reduced inflammation.

Disclosure

C. J. Choi: None. W. Barr: None. M. Koenen: None. Z. Lin: None. S. Szwed: None. P. Cohen: None.

Funding

American Diabetes Association/Pathway to Stop Diabetes (1-17-ACE-17 to P.C.)
306-OR: Changes in Adipose-Derived Circulating MicroRNA Levels and Improvements in Visceral and Ectopic Fat Depots and Insulin Sensitivity: The CENTRAL Trial
Authors: HEIANZA YORIKO , KROHN KNUT K. , WANG MENGYING , MEIR ANAT YASKOLKA , XUE QIAOCHU , ZIESCHE STEFANIE , CEGLAREK UTA , BLÜHER MATTHIAS , KELLER MARIA , KOVACS PETER , SHAI IRIS , QI LU
Published: June 2021

MicroRNAs (miRNAs) are small non-coding RNAs, and adipose tissue is a major source of circulating miRNAs that may regulate body fat distribution. We investigated whether changes in circulating adipose-derived miRNAs (miR-99a-5p, miR-99b-5p, and miR-100-5p) were related to improvements in visceral and ectopic fat depots in abdominal obese adults who participated in the CENTRAL diet-and-lifestyle intervention trial. We further tested whether changes in these miRNAs were related to improved glucose metabolism and insulin sensitivity after the intervention. Plasma levels of miRNAs were measured both at baseline (n=227) and 18 months (n=157) after the intervention; changes in miRNAs from baseline to 18 months were calculated. Magnetic resonance imaging (MRI) was performed to assess visceral adipose tissue (VAT), intrahepatic fat %, and pancreatic fat %. At baseline, higher levels of miR-99a-5p and miR-100-5p were associated with greater intrahepatic fat (p <0.0001 for both). The study participants showed considerable differences in circulating miRNA changes in response to the diet/physical activity intervention, and greater decreases in miR-99a-5p were associated with greater improvements in VAT (p=0.0027) and intrahepatic fat (p=0.015) at 18 months. Similarly, the reduction of miR-100-5p was related to 18-month improvements in VAT (p=0.0025) and intrahepatic fat (p=0.0023). Further, decreases in miR-99b-5p (p=0.038) and miR-100-5p (p=0.033) levels were associated with improved pancreatic fat at 18 months. Participants with more decreases in miR-99b-5p had reduced pancreatic fat and were also characterized as having lower glucose levels and higher HOMA of β-cell function at the end of the intervention. Our findings underscore the importance of changes in specific adipose-derived circulating miRNAs in improving diabetogenic fat depots and insulin sensitivity during the intervention for abdominal obese patients.

Disclosure

Y. Heianza: None. P. Kovacs: None. I. Shai: None. L. Qi: None. K. K. Krohn: None. M. Wang: None. A. Yaskolka meir: None. Q. Xue: None. S. Ziesche: None. U. Ceglarek: Research Support; Self; Roche Diagnostics Germany. M. Blüher: Consultant; Self; Amgen Inc., AstraZeneca, Bayer AG, Boehringer Ingelheim International GmbH, Lilly Diabetes, Novo Nordisk, Sanofi-Aventis Deutschland GmbH, Speaker’s Bureau; Self; Daiichi Sankyo, Novartis AG. M. Keller: None.

Funding

National Institute of Diabetes and Digestive and Kidney Diseases (DK091718, DK100383, DK115679)