bluuebunny/crossref_metadata_2025_split huggingface dataset:
1705-P: Adipocyte Specific Ablation of P2Y14R Improves Glucose Metabolism in Mice with Diet-Induced Obesity
Authors: JAIN SHANU , JACOBSON KENNETH A. 
Published: June 2020

Adipose tissue is one of the major tissues in body regulating glucose and energy homeostasis. White adipose tissue (iWAT) serves as primary site of energy storage while brown (BAT) and beige AT play a major role in energy expenditure. AT also exerts endocrine effects by secreting various adipokines/batokines regulating whole body glucose metabolism. Diverse G protein-coupled receptors (GPCRs) are expressed in adipocytes and thus have emerged as potential targets for novel antidiabetic drugs. P2Y purinergic receptors are a class of GPCRs activated by nucleotides and nucleotide sugars. The purinergic P2Y14 receptor (P2Y14R) is natively activated by UDP-glucose. P2Y14R is expressed in white as well as brown adipocytes, and receptor mRNA levels was increased in iWAT due to high fat feeding. The potential role of P2Y14R in AT with respect to maintaining whole body glucose homeostasis remains unexplored. To this end, we generated a knockout mouse model lacking P2Y14R selectively in adipocytes (Ad-P2Y14-KO) using Cre/loxP technology. Interestingly, Ad-P2Y14-KO consuming a high fat diet gained less weight than the control mice. Body composition revealed that the decrease in body weight gain in Ad-P2Y14-KO was due to a decrease in fat mass. Decreased body weight resulted in improved glucose tolerance and insulin sensitivity in Ad-P2Y14-KO. Moreover, fasting blood glucose and fed plasma insulin levels were decreased in Ad-P2Y14-KO. Circulating levels of adipokines such as leptin were decreased in knockout mice, indicating increased sensitivity to leptin in Ad-P2Y14-KO. Interestingly, a lack of P2Y14R signaling increased lipolysis in adipocytes, as plasma free fatty acids levels was elevated in Ad-P2Y14-KO in the fasting state. Liver weight was decreased in Ad-P2Y14-KO indicating a lack of ectopic deposition of fat due to enhanced lipolysis. Mechanistic studies are underway to link the observed phenotype with P2Y14R signaling in adipocytes.

Disclosure
S. Jain: None. K.A. Jacobson: None.
1707-P: Differential Effect of Prolonged Glucagon Infusion on Plasma Lipidome in Humans
Authors: CHEN XI , HAN XIANLIN , TREJO JONATHAN , CASE EMINA , DEFRONZO RALPH A. , TRIPATHY DEVJIT 
Published: June 2020

Hyperglucagonemia plays an important role in pathogenesis of T2DM. The effect of glucagon on the plasma lipidome has not been studied in humans. We examined the effect of prolonged glucagon infusion on plasma lipid metabolites in healthy subjects. 8 NGT subjects (5M/3F, age=35±5, BMI=24±1, A1c=5.3±0.3%) received 12-hour (6PM to 6AM) glucagon infusion (6ng/kg/min). On a different day the subjects returned for a repeat study with infusion (6PM to 6AM) of normal saline. Top-ranking plasma lipidomes were measured by shotgun lipidomics including Phosphatidylethanolamine (PE), Lysophosphatidylethanolamine (LPE), Phosphatidylcholine (PC), Lysophosphatidylcholine (LPC), Ceramide (CER), Sphingomyelin (SM), Acylcarnitine (AC), Phosphatidylglycerol (PG), Phosphatidylinositol (PI), Phosphatidylserine (PS), Triacylglycerol (TAG), Fatty Acyl Chains in TAG (FA). Plasma glucagon increased from 57±3 to 219±21 pg/ml. Plasma insulin increased significantly following glucagon compared to saline (20±7 vs. 8±3 mU/L, p&lt;0.05) and remained elevated. Plasma LPE, PC, LPC, CER, SM, FFA, AC increased, plasma PE, PS declined, and PG, PI, FA did not change following 12-hour glucagon infusion. The greatest increase occurred with Lysophosphatidylcholine (LPC, 18:2) which rose ∼2.5 fold (126±11 vs. 51±7 nmol/ml, p&lt;0.005) following glucagon infusion. LPCs and LPEs are generated after activation of phospholipase A2, along with the release of fatty acids, and have been reported to induce inflammation and the effector of fatty acid induced insulin resistance. On the other hand, reduced PE is observed in animal models of obesity, supporting its role as a substrate of phospholipase A2 activation. Increased ceramide levels also have been shown to incite inflammation.
In conclusion, prolonged glucagon infusion modulates novel lipid metabolites involved in inflammation and represents a fundamental mechanism by which glucagon activates inflammation pathways, contributing to insulin resistance.

Disclosure
X. Chen: None. X. Han: None. J. Trejo: None. E. Case: None. R.A. DeFronzo: None. D. Tripathy: None.

Funding
Foundation for Advancement of Veteran’s Health and Research
1721-P: In Vivo Effect of Perturbations in Hepatic Insulin Signaling on the Synthesis and Export of De Novo Synthesized Fatty Acids and Triglycerides
Authors: KUCEJOVA BLANKA , DEJA STANISLAW , DUARTE JOAO , FU XIAORONG , BURGESS SHAWN C. 
Published: June 2020

Hepatic lipid synthesis and Vldl production plays a major role in whole body lipid homeostasis. Insulin imposed regulation of liver metabolism is in large part executed on a transcriptional level. Several published studies focused on the effect of hepatic insulin resistance and the role of mTORC1 in liver lipid metabolism, sometimes with conflicting results. Here we used mouse genetic models with short-term liver specific removal of the insulin receptor (complete signaling pathway inactivation), Tsc1 (mTORC1 activation), Raptor (mTORC1 inactivation), Pten (simultaneous mTORC1 and Akt activation), and Raptor Pten (simultaneous mTORC1 inactivation and Akt activation) to precisely dissect the role of insulin signaling in the regulation of lipid metabolism. In vivo 2H2O administration, 1H and 2H NMR analyses revealed hepatic de novo fatty acid (FA) and triglyceride (TG) synthesis, export, as well as FA profiles both in liver and plasma. By direct examination of in vivo hepatic de novo lipogenesis (DNL), the direction and magnitude of changes observed in lipogenic gene expression did not correlate well with differences observed in DNL flux. For example, PtenLKO mice had a 3-fold increase in DNL flux with little effect on lipogenic gene expression. Our results suggest that in some contexts other factors, possibly including metabolite availability, TCA cycle metabolism, redox state or energy charge impose stronger control over DNL than regulation of gene expression. We also show that triglyceride synthesis and incorporation of de novo synthesized FA into triglycerides is regulated by mTORC1. While mTORC1 positively regulates export of newly synthesized TG it has a negative effect on export of de novo produced FA.

Disclosure
B. Kucejova: None. S. Deja: None. J. Duarte: None. X. Fu: None. S.C. Burgess: None.

Funding
National Institutes of Health (R01DK078184)
1724-P: MicroRNA Regulation of Endothelial Cell Secretion of Placental Growth Factor and Adipose Browning
Authors: PÉREZ-CREMADES DANIEL , BECKER-GREENE DAKOTA R. , LI HAO , WU WINONA , AYDOGAN CEREN O. , OZDEMIR DENIZHAN , FEINBERG MARK W. , ICLI BASAK 
Published: June 2020

Brown adipose tissue (BAT), a highly vascularized, thermogenic tissue, converts chemical energy into heat. The ability of BAT to expand based on the metabolic demand, known as plasticity, plays a critical role in the regulation of whole body energy balance. Endothelial cells (ECs) within the microvasculature of the adipose tissue play an important role in aiding BAT retain plasticity by actively modulating the angiogenic response. However, the mechanism of EC-adipocyte cross-talk during this process is not completely understood. In BAT ECs of obese mice, we have previously identified an anti-angiogenic microRNA, miR-409-3p, using a RNA-seq profiling approach. We now show that miR-409-3p targets MAP4K3 to confer its anti-angiogenic effects in ECs. Overexpression of miR-409-3p markedly decreased MAP4K3 expression in ECs, whereas inhibition of miR-409-3p had the opposite effects. SiRNA knockdown of MAP4K3 expression in ECs phenocopied the effects of miR-409-3p overexpression and significantly decreased cell proliferation and migration. Adipocytes co-cultured with conditioned media from ECs deficient in miR-409-3p showed increased expression of brown fat markers UCP1 and Cidea by RT-qPCR and Western. By multiplex ELISA, we identified a pro-angiogenic growth factor, Placental Growth Factor (PLGF), that is released from ECs in response to miR-409-3p deficiency. PLGF stimulation of 3T3-L1 adipocytes differentiated them into brown adipocytes. Furthermore, siRNA knockdown of MAP4K3 blocked the release of PLGF from ECs. Co-culturing conditioned media from ECs deficient in PLGF expression by siRNA silencing significantly decreased UCP1 expression in 3T3-L1 adipocytes, whereas conditioned media from ECs deficient both in miR-409-3p and PLGF further decreased UCP1 expression showing dependency for miR-409-3p regulated pathways. MiR-409-3p plays a key role in EC-BAT crosstalk by modulating PLGF, an effect that could be exploited for therapeutic intervention in obesity.

Disclosure
D. Pérez-Cremades: None. D.R. Becker-Greene: None. H. Li: None. W. Wu: None. C.O. Aydogan: None. D. Ozdemir: None. M.W. Feinberg: None. B. Icli: None.

Funding
American Diabetes Association (1-16-JDF-046 to B.I.)
173-LB: Two Cases of Autoimmune Type 1 Diabetes Mellitus (DM) with Prolonged Honeymoon Phase Leading to Partial and Complete Remission following Pregnancy
Authors: KRISTAN MEGAN M. , KIM YOON KOOK , THOMAS SNEHA E. , MUNIR KASHIF M. 
Published: June 2020

Background and Purpose: Describe clinical course and outcomes of two cases of autoimmune DM who experienced remission and have remained insulin-free or on significantly reduced doses following pregnancy.
Case Description: Case 1: 41 year old female G1P0 at 27w1d presented with diabetic ketoacidosis and was found to have new onset autoimmune diabetes with positive anti-GAD antibodies. She was treated with insulin therapy through the remainder of her pregnancy, and at post-partum follow-up found to be having hypoglycemic episodes. Insulin therapy was titrated down and eventually stopped. She has remained insulin-free with A1C &lt;6% for two and a half years. Case 2: 28 year old female G2P2002 with history of DM 1 since age 8 at 33w6d presented with preeclampsia requiring early induction. Her hospital course was complicated by severe hypoglycemia. She was discharged on 14% of her pre-pregnancy insulin dose and was still hypoglycemic while on only 3 units of glargine.
Outcome: Two cases of autoimmune DM with prolonged remission following pregnancy requiring little to no insulin therapy.
Discussion: During pregnancy, multiple biological adaptations lead to increased insulin resistance and clearance, and following deliver many of these alterations revert and allow return to pre-pregnancy insulin dosing. These two cases demonstrate prolonged honeymoon phase. In addition to the cases, a literature review of the physiology of honeymoon phase including development of immunologic tolerance and possible mechanisms of resolution of autoimmune DM including suppression of autoimmunity and development of endogenous insulin production is included.

Disclosure
M.M. Kristan: None. Y. Kim: None. S.E. Thomas: None. K.M. Munir: None.
1730-P: Thromboxane Signaling and Obesity-Related Insulin Resistance
Authors: ALVAREZ DIEGO ALCARAZ , VISWANATHAN SARASWATHI , THANGAVELU THIYAGARAJAN , KUMAR NARENDRA , KELLEY KATELYN , DESOUZA CYRUS 
Published: June 2020

Background: Thromboxane A2 (TxA2), a lipid mediator plays a critical role in cardiovascular disease and chronic inflammatory disorders. TxA2 signaling is regulated by TxA2 synthase (Tbxas1), an enzyme that produces TxA2, and TxA2 receptor (Tbxa2r).
Objective: To determine if Tbxa2r gene expression in adipose tissue (AT) is higher in obese insulin resistant (IR) subjects compared to overweight non-IR subjects.
Methods: Insulin resistance was measured via a homeostatic model assessment of insulin resistance (HOMA-IR). Subcutaneous AT biopsies were obtained from overweight (BMI between ≥25 to &lt;30) no IR and obese (BMI ≥30) IR (HOMA-IR&gt;2.5) subjects. Gene expression of Tbxa2r and Tbxas1 were analyzed in tissue samples and compared between groups.
Results: The mRNA levels of Tbxa2r and Tbxas1 were significantly higher in obese IR subjects compared to overweight subjects (P&lt;0.05). A positive correlation was observed between AT expression of Tbxa2r and Tbxas1 (Spearman’s r=0.49, n=35, P&lt;0.01). We noted a weak positive correlation between AT Tbxa2r and HOMA-IR (Spearman’s r=0.31, n=35, P&lt;0.07). A positive correlation was also noted between AT Tbxas1 and HOMA-IR (Spearman’s r=0.42, n=37, P&lt;0.05).
Conclusion: Our data suggest that TxA2 signaling is activated in AT in obesity and is associated with the development of insulin resistance in obesity. Tbxas1 and/or Tbxa2r may be a potential therapeutic target for obesity-linked metabolic diseases.

Disclosure
D. Alcaraz Alvarez: None. S. Viswanathan: None. T. Thangavelu: None. N. Kumar: None. K. Kelley: None. C. Desouza: Consultant; Self; AstraZeneca, Bayer AG, Novo Nordisk A/S.
1736-P: Insulin Resistance and Mitochondrial Dysfunction Mediated by Nat1 Deficiency
Authors: SANGWUNG PANJAMAPORN , FATHZADEH MOHSEN , KNOWLES JOSH 
Published: June 2020

Insulin resistance (IR) is fundamental to the pathophysiology of type 2 diabetes (T2D) and a major risk factor for cardiovascular disease (CVD). Therapeutic options for IR are limited, reinforcing the need to understand IR pathways with an aim to develop IR-specific medications. We previously identified human N-acetyl transferase 2 (NAT2) as a novel insulin sensitivity gene. In vitro and in vivo studies demonstrated an association of mouse Nat1 (ortholog of human NAT2) deficiency with both IR and mitochondrial dysfunction. However, the underlying mechanism of how Nat1 deficiency causes IR and mitochondrial dysfunction is unknown. Using engineered ascorbate peroxidase-proximity labeling in cells followed by mass spectrometry-based proteomic analysis, we are mapping Nat1 endogenous targets and Nat1 interacting proteins. Verification of the interacting proteins and functional validation will be achieved by co-immunoprecipitation, siRNA knockdown, glucose uptake and lipolysis assays, and mitochondrial functional assays in mouse liver cells and adipocytes. We have also created a liver specific Nat1-deficient mouse model and will determine whether this is sufficient to cause whole body changes in insulin sensitivity. Collectively, these studies will shed light on mechanism of how the novel IR gene Nat1 participates in the pathophysiology of IR, which is a necessary step for the development of new treatments for T2D and CVD.

Disclosure
P. Sangwung: None. M. Fathzadeh: None. J. Knowles: None.

Funding
American Diabetes Association (1-19-JDF-108 to J.K.); U.S. Public Health Service; National Institute of Diabetes and Digestive and Kidney Diseases (R01DK107437, R01DK106236, P30DK116074, 1R01DK116750 to J.K.)
1737-P: Defining Distinct Actions of Insulin and IGF1 Receptors and Their Extra and Intracellular Domains at the Level of the Phosphoproteome
Authors: NAGAO HIROFUMI , CAI WEIKANG , BATISTA THIAGO M. , PAN HUI , DREYFUSS JONATHAN , KAHN C. RONALD 
Published: June 2020

Insulin and IGF-1 regulate a wide variety of biological processes through insulin and IGF-1 receptors (IR and IGF1R). These receptors are highly homologous and share many overlapping downstream signaling pathways. To determine differences in signaling between IR and IGF1R that could account for their unique physiological actions, we performed global phosphoproteomic analysis of preadipocytes lacking both endogenous receptors then reconstituted with IR, IGF1R, and chimeric IR_IGF1R and IGF1R_IR receptors. Over 26,000 phosphosites were quantified. Hierarchical clustering revealed 3208 significant differentially regulated phosphosites between IR and IGF1R. These included major differences of several large networks following ligand stimulation. Thus, many phosphosites associated with mTOR signaling were preferentially up-regulated by IR, whereas many phosphosites associated with Rho-GTPases and cell cycle were uniquely up-regulated by IGF1R. Interestingly, there were also many differences in the phosphoproteome between IR and IGF1R in the basal state indicating important differences in signaling by the unoccupied IR and IGF1R. These related to membrane trafficking, chromatin remodeling, Rho-GTPase signaling and cell cycle. When these data were compared to the phosphoproteome of cells expressing IR and IGF1R chimeric receptors, i.e., receptors with the extracellular domain (ECD) of IR fused to the intracellular domain (ICD) of IGF1R and vice versa, we found that many of the differences between IR and IGF1R in the ligand-stimulated state depended on differences in the ICD of IR vs. IGF1R, whereas many differences in the basal state depended on the ECD. Thus, despite high homology, IR and IGF1R regulate different networks of proteins in both the basal and stimulated states. Understanding these pathway differences provides the unique opportunity to differentially modulate insulin and IGF-1 signaling at the post-receptor level.

Disclosure
H. Nagao: None. W. Cai: None. T.M. Batista: None. H. Pan: None. J. Dreyfuss: None. C. Kahn: Advisory Panel; Self; ERX Pharmaceuticals, Kaleido Biosciences. Consultant; Self; AntriaBio, Flagship Pioneering, Sana-Cobalt.
174-OR: Budget Impact Analysis (BIA) Comparing Real-Time Continuous Glucose Monitoring (RT-CGM) with Self-Monitoring of Blood Glucose (SMBG) for all U.S. Medicaid Enrollees with Type 1 Diabetes
Authors: MINSHALL MICHAEL E. , ISITT JOHN J. , GRAHAM CLAUDIA , LYNCH PETER M. 
Published: June 2020

A BIA was performed comparing clinical cost offsets for rt-CGM compared with SMBG for U.S. Medicaid enrollees with type 1 diabetes (T1D) over one year. Clinical effects for HbA1c reduction using rt-CGM (-1.0%) and SMBG (-0.4%) were taken from the DIAMOND randomized controlled trial, converted into an economic benefit, and inflated ($U.S. 2019). Reduced hospitalization rates for severe hypoglycemia (SH; -73%) and diabetic ketoacidosis (DKA; -80%) were taken from the RESCUE trial, a Belgian observational cohort study, where SMBG was used in the year prior to countrywide rt-CGM reimbursement and outcomes tracked for one year. Estimated cost savings for HbA1c reduction (low and high), SH and DKA hospitalizations were taken from published literature and inflated ($U.S. 2019). We tested various ranges of pricing for rt-CGM and SMBG. Switching all U.S. Medicaid enrollees with T1D from SMBG to rt-CGM would result in an estimated 51,796 and 21,253 fewer SH and DKA hospitalizations, respectively, per year. Applying the clinical cost offsets against the added cost for rt-CGM over SMBG resulted in cost savings in most scenarios. Our modelling study demonstrates the substantial clinical and economic benefits using rt-CGM over SMBG in all U.S. Medicaid enrollees with T1D.

Disclosure
M.E. Minshall: Consultant; Self; Dexcom, Inc. J.J. Isitt: Employee; Self; Dexcom, Inc. C. Graham: Consultant; Self; Dexcom, Inc., DreaMed Diabetes. P.M. Lynch: Employee; Self; Dexcom, Inc. Stock/Shareholder; Self; Dexcom, Inc.

Funding
Dexcom, Inc.
1751-P: Induction of Sirt1-AMPK Pathway by GLP-1RA Liraglutide Reduces Hepatic Lipid Accumulation and Insulin Resistance
Authors: HUANG CHIEN-NING , LI HSIN-HUA , PENG CHIUNG-HUEI , KORNELIUS EDY , YANG YI SUN , CHIU LING-YEN , LIN CHIH-LI 
Published: June 2020

Hepatic insulin resistance is associated with metabolic disorders such as type 2 diabetes (T2D), which often develops after the accumulation of lipids in the liver. In particular, elevated plasma levels of free fatty acids (FFA) are the primary sources of hepatic lipid accumulation that contributes to the development of insulin-resistant states. Interestingly, one gut-derived incretin hormone receptor called glucagon-like peptide 1 (GLP-1) receptor, is highly expressed on human hepatocytes. Although GLP-1-based therapies have shown great benefit in the treatment of T2D with improved glycemic control, they also additionally possess extrapancreatic metabolic actions including that in the liver. Studies have demonstrated that GLP-1 receptor agonist (GLP-1 RA) may reverse the progression of nonalcoholic fatty liver disease (NAFLD), a T2D-related disorder characterized by hepatic lipid accumulation. This suggests GLP-1 RA may be effective treatment options for NAFLD and associated hepatic disorders, but the mechanism behind this is still unknown. In the present study, we investigated the function of GLP-1 signaling in protecting human HepG2 hepatocytes from FFA-related damages. By using high-content analysis (HCA) cellomics techniques, we found that treatment with the GLP-1 RA liraglutide has shown a significant lipid droplets-lowering effect in hepatocytes exposure to high levels of FFAs. Liraglutide also decreased free radical generation and subsequently reduced oxidative stress, thus alleviated FFA induced inflammation. Moreover, activation of AMPK by liraglutide increased insulin sensitivity and improved oxidative stress-induced senescence by inducing Sirt1 pathway. Collectively, our results demonstrated that hepatic GLP-1 signaling may play a crucial role in the regulation of lipid deposits and related disorders in liver. This suggests the potential therapeutic usage of GLP-1 RA-based strategies for patients with T2D who also have NAFLD.

Disclosure
C. Huang: None. H. Li: None. C. Peng: None. E. Kornelius: None. Y. Yang: None. L. Chiu: None. C. Lin: None.

Funding
Ministry of Science and Technology of Taiwan (108-2314-B-040-021-MY3)
1765-P: PACAP from the Ventromedial Hypothalamic Nucleus Controls Energy Expenditure
Authors: JOHNSON DAVID Q. , FLAK JONATHAN 
Published: June 2020

Body energy homeostatic mechanisms dynamically balance energy expenditure with energy intake, and the brain plays a critical role in this process. However, the specific circuits responsible for controlling energy expenditure are only superficially understood. Because Ventromedial Hypothalamic (VMN)-specific expression of pituitary adenylate cyclase-activating polypeptide (PACAP) decreases with both under-nutrition and loss of leptin action, we tested the hypothesis that VMN PACAP controls energy expenditure. Since PACAP is expressed in the periphery, we administered a VMN-targeted injection of AAVcre in PACAPflox mice to remove VMN PACAP (PACAPVMNKO), which resulted in a near complete bilateral ablation of PACAP mRNA in the VMN without interfering with PACAP mRNA in nearby sites (e.g., preoptic area (POA) and medial amygdala). In both male and female mice, PACAPVMNKO induced massive obesity and more than a two-fold increase in adipose mass. This induced obesity, similar to other VMN loss of function studies, is due to chronically suppressed energy expenditure because VO2, but not activity, was decreased in these mice. PACAPVMNKO mice were also hyperinsulinemic, hyperglycemic, and exhibited impaired glucose clearance in the hyperinsulinemic/hyperglycemic clamp. However, PACAPVMNKO mice were normoglycemic 4 weeks post-injection (prior to obesity), indicating that glycemic effects were secondary to obesity. Because the VMN does not contain directly pre-autonomic neurons, PACAP must activate a circuit via a downstream site to stimulate energy expenditure. PAC1r cells primarily overlay with VMN projections in the POA and to a lesser extent in the periaqueductal grey and bed nucleus of the stria terminalis. VMN PACAP, as well as associated signaling targets, are critical components to the control of energy balance by activating energy expenditure.

Disclosure
D.Q. Johnson: None. J. Flak: None.

Funding
American Diabetes Association/Pathway to Stop Diabetes (1-17-INI-15 to J.F.); National Institutes of Health (DK020572)