bluuebunny/crossref_metadata_2025 huggingface dataset:
1632-P: Increasing Incidence of Type 1 Diabetes in Children in Poland
Authors: NIECHCIAL ELZBIETA , MICHALAK MICHAL , FICHNA PIOTR
Published: June 2020

Objective: The purpose of this study was to describe the incidence of T1D in children in Wielkopolska province (Poland) from 2006 to 2018 and compare these data with previous data recorded between 1998-2003.

Research Design: Diabetes cases were obtained through a retrospective population-based registry. Hospital inpatient records were reviewed and met the following criteria: newly diagnosed T1D age 0-14 years, residing in Wielkopolska province at the time of diagnosis, and diagnosed from 1 January 2006 to 31 December 2018. The secondary source of validation were Diabetes Outpatient Clinics located in different parts of Wielkopolska province. Incidence rates were compared with 1998-2003 cohorts.

Results: A total of 1484 case subjects were identified during the study period, and the registry was determined to be 95% complete. In study period, a significant upward trend in the incidence of T1D was observed from 9.2/100,000/year in 2006 to 30.8/100,000/year in 2018. The peak incidence of 35.2/100,000/year was recorded in 2008. The mean age-specific incidence was greatest in children aged 5-9 years 22.6/100,000/year, while lowest in those aged 0-4 years 13.7/100,000/year. In youth aged 10-14 years, the predominance in males was documented (p=0.0007). Children aged 0-4 were characterized by different seasonal pattern at diabetes onset (mostly diagnosed in spring/summer months) than individuals over age of 10 years who were diagnosed mostly during the winter and autumn months. In a 20-year period, the incidence of T1D increased 3.5-fold from 8.4/100,000/year in 1998 to 30.8/100,000/year in 2018.

Conclusions: The incidence of T1D in Wielkopolska province is increasing. The etiology of the marked increase in incidence in the polish population is unknown, however, such rapid increase in a very short period rather is associated with environmental factors than changing in genetic background. Seasonality of the disease is not a regular occurrence, which suggests increasing role of non-seasonal factors in the growing incidence.

Disclosure

E. Niechcial: None. M. Michalak: None. P. Fichna: None.
164-OR: Role of Small Extracellular Vesicles for the Metabolic Response to Exercising in Insulin Resistant Humans
Authors: MASTROTOTARO LUCIA , APOSTOLOPOULOU MARIA , HARTWIG SONJA , PESTA DOMINIK , STRASSBURGER KLAUS , DEFILIPPO ELISABETTA , KARUSHEVA YANISLAVA , GANCHEVA SOFIYA , MARKGRAF DANIEL F. , LEHR STEFAN , MUSSIG KARSTEN , AL-HASANI HADI , SZENDROEDI JULIA , RODEN MICHAEL
Published: June 2020

Small extracellular vesicles (SEV) are secreted into circulation after acute exercise suggesting a new mode of tissue crosstalk. High intensity interval training (HIIT) leads to improved insulin sensitivity and oxidative capacity in patients with type 2 diabetes. As the impact of HIIT on SEV release is unknown, this study examined its effects on number and proteome of SEV in insulin sensitive (IS) and insulin resistant (IR) humans to identify biomarkers for the early prediction of individual responses of insulin sensitivity to exercising.

Eight T2D, 8 glucose tolerant IR and 6 IS humans with similar age and BMI (HbA1c in %: 7.4 ± 0.4, 5.3 ± 0.1, 5.5 ± 0.1; M-value in mg*kg-1*min-1: 1.8 ± 0.4, 4.1 ± 0.4, 7.2 ± 0.5) performed a 12-weeks HIIT cycling protocol for 3 days/week. Before the intervention (baseline) and 72 h after the last exercise bout, whole-body insulin sensitivity was assessed by hyperinsulinemic-euglycemic clamps and serum samples were collected to isolate SEV by size exclusion chromatography. SEV size and number were measured by Nanoparticle Tracking Analysis and proteomic profiling was done by mass spectrometry using data independent acquisition. After 12 weeks of HIIT, T2D and IR improved their insulin sensitivity (M-value: T2D 3.5 ± 0.8, IR 6.2 ± 0.7; p<0.01 vs. baseline) and increased the number of circulating SEV by 52 ± 19% and 58 ± 21% (p<0.05 vs. baseline). Quantitative proteomic analysis of SEV revealed that HIIT regulated 258 proteins (118 in T2D, 125 in IR, 89 in IS) with an enrichment of proteins related to glycolysis in T2D, to antioxidative metabolism in IR and to lipid metabolism in IS.

In conclusion, HIIT increases SEV number, but differently affects SEV mass and proteome in IS and IR humans, suggesting that SEV cargo could contribute to the individual response of insulin sensitivity to HIIT. Detailed characterization of SEV cargo can help to better understand the mechanisms of tissue crosstalk in the adaptation to exercise training and to develop novel exercise mimetics.

Disclosure

L. Mastrototaro: None. M. Apostolopoulou: None. S. Hartwig: None. D. Pesta: None. K. Strassburger: None. E. DeFilippo: None. Y. Karusheva: None. S. Gancheva: None. D.F. Markgraf: None. S. Lehr: None. K. Mussig: None. H. Al-Hasani: Consultant; Self; Bayer AG. J. Szendroedi: None. M. Roden: Advisory Panel; Self; Servier. Board Member; Self; Poxel SA. Consultant; Self; Eli Lilly and Company, Gilead Sciences, Inc., ProSciento, TARGET PharmaSolutions. Research Support; Self; Boehringer Ingelheim International GmbH, Novartis Pharma K.K., Sanofi US. Speaker’s Bureau; Self; Novo Nordisk A/S.
1641-P: Changes in Adipocyte Function in Response to Weight Gain in Young, Lean European and South Asian Men
Authors: GAO XUAN , MCLAREN JAMES , FREEMAN DILYS J. , GILL JASON M.R.
Published: June 2020

South Asians (SA) develop T2DM at younger age and lower BMI than Europeans (EU). We hypothesized that a low ability of pre-adipocytes to differentiate to adipocytes resulting in hypertrophy may explain the high risk of T2DM. Abdominal subcutaneous adipose tissue was obtained at baseline (BL) and after 6.3[SD1.3] % weight gain (WG) from 20 EU and 13 SA. Adipocytes and pre-adipocytes were isolated and adipocyte diameter measured. Gene expression was quantified relative to PPIA by rtPCR after pre-amplification and analysed using a mixed model. Diameter increased after WG in EU (BL 71[8] vs. WG 76[10] µm p=0.007, paired t test) but not in SA (85[12] vs. 86[11] µm p=0.40). SA had more large (L 90-145μm) and very large (VL >145μm) adipocytes than EU at BL (L 37.3 vs. 16.7%, VL 1.92 vs. 0.25 % p<0.001, χ2 test) and after WG (41.1 vs. 23.1 %, 1.85 vs. 0.17 % p<0.001). Proportions of small (S <45µm) and L (S 10.0 vs. 4.7 %, L 16.7 vs. 23.1 % p<0.001) adipocytes were reduced and increased respectively in EU after WG. Smaller changes were seen in SA (S 6.2 vs. 4.1 %; L 37.3 vs. 41.0 % p=0.001). At BL and WG TNF expression was higher in SA (EU 0.04[0.04] vs. SA 0.12[0.15] % expression/PPIA p=0.004) while ADIPOQ (1069[372.1] vs. 874.1[271.8] % p=0.042) and ESR1 (6.7[3.0] vs. 4.2[2.8] % p<0.001) were lower. SREBF1 and LEP expressin were higher in SA and increased after WG, while INSR, SIRT1, CIDEA, GHR and PLIN2 were lower in SA and reduced after WG. An interaction (p=0.06) was found between ethnicity and WG for APOE which decreased after WG to a greater extent in EU (EU 42.2 vs. SA 16.6 % change in expression p<0.001). To conclude, SA store fat in larger adipocytes than EU that are minimally altered by WG. SA adipocytes express higher levels of inflammation and fat storage genes and lower levels of insulin sensitivity and adipogenesis genes which are further increased and decreased respectively by WG. The adverse impact of WG on SA adipocyte may underlie their higher risk of T2DM. Assessment of pre-adipocyte differentiation ability in response to WG is underway.

Disclosure

X. Gao: None. J. McLaren: None. D.J. Freeman: None. J.M.R. Gill: None.
1644-P: High Throughput Approach Enables Expanded Clustering of Type 2 Diabetes Genetic Loci Informed by Phenotypic Associations
Authors: KIM HYUNKYUNG , VON GROTTHUSS MARCIN , MERCADER JOSEP M. , CHIOU JOSHUA , GAULTON KYLE J. , MANNING ALISA , FLOREZ JOSE C. , UDLER MIRIAM
Published: June 2020

Improved understanding of disease-causing pathways for type 2 diabetes (T2D) may lead to novel therapeutic targets and individualized treatment. Rapid expansion in the number of T2D genetic loci over the past few years can be leveraged to identify pathways via cluster analysis.

We developed an automated pipeline to enable clustering of T2D genetic loci starting with genome-wide association study (GWAS) summary statistics from 6 European T2D studies. The pipeline 1) extracts variants reaching genome-wide significance, 2) replaces multi-allelic, ambiguous (A/T, C/G), or low-trait count SNPs with appropriate proxies, and 3) filters for independent signals using r2=0. Traits in the T2D Knowledge Portal with summary GWAS data in European populations were included if they met a minimum Bonferroni p-value across the selected variants. This pipeline generated a matrix of associations for 259 independent T2D variants and 32 traits to which we applied Bayesian Non-negative Matrix Factorization (bNMF) clustering.

We identified 6 robust clusters of T2D loci, 5 of which overlapped with a previously published analysis of 94 loci. Three clusters indicated variant-trait associations related to insulin deficiency, while the other three clusters displayed insulin resistance-related features including: obesity, lipodystrophy, and liver-lipid metabolism. The new cluster identified in this analysis is related to beta cell function. Increased polygenic scores for clusters were associated with distinct clinical outcomes in GWAS, including coronary artery disease (UK BioBank CARDIoGRAM), ischemic stroke (MEGASTROKE), chronic kidney disease (CKDGen). Clusters also displayed tissue-specific epigenomic enrichment.

Our approach expands upon previous clustering work of T2D loci and allows for efficient updating as additional GWAS results become available. This method can also be readily applied to other diseases beyond T2D to identify key pathways.

Disclosure

H. Kim: None. M. von Grotthuss: None. J.M. Mercader: None. J. Chiou: None. K.J. Gaulton: Consultant; Self; Genentech, Inc. Employee; Spouse/Partner; Vertex Pharmaceuticals. A. Manning: None. J.C. Florez: Advisory Panel; Self; Doris Duke Charitable Foundation. Other Relationship; Self; Novo Nordisk Inc., Park Street School. M. Udler: None.

Funding

National Institutes of Health
165-LB: Increasing Heart-Healthy Behaviors in Youth with Type 1 Diabetes (T1D): A Feasibility Study
Authors: KAUSHAL TARA , CHARMANT CHARNICE O. , VOLKENING LISA K. , LAFFEL LORI M. , KATZ MICHELLE
Published: June 2020

Background: Diabetes increases cardiovascular disease (CVD) risk, yet many youth with T1D are not effectively managed for hypertension (HTN) or hyperlipidemia (HPL). Lifestyle management remains 1st-line pediatric therapy, creating a need for effective clinical interventions. As digital health and financial incentives may help motivate behavior change, we sought to test feasibility of a scalable digital health intervention to motivate heart healthy behaviors in youth with T1D.

Methods: We recruited 44 teens (ages 14-19 years; T1D duration ≥6 months; and either HTN, HPL, overweight/obesity, or A1C ≥8%) into a 3-month pilot RCT. Teens were randomized 1:1 to intervention (INT) or control (C) groups. INT received educational/goal-setting modules and bi-weekly team challenges using a smartphone with participants earning points leading to financial rewards; C group received educational/goal-setting modules after 3 months. Primary outcome was the Adolescent Food Habits Checklist (AHFC), a 23-item questionnaire (higher score = healthier food habits), administered at baseline and after 3 months. Participants completed a satisfaction survey after the RCT.

Results: At entry, the sample was 30% male, 88% non-Hispanic white, aged 17±1.6 (X±SD) yrs with T1D duration 8.7±3.3 yrs; 82% were pump-treated, 63% used CGM, A1C was 9.3±1.6%; BMI %ile was 84±17, BP 106±9/66±6, LDL 99±33 mg/dL. Groups only differed in BMI %ile (INT 90 vs. C 77, p<.03). Both groups increased their AHFC scores over time (INT +3.5, p<.01; C +2.3, p<.03); change in AHFC did not differ between groups (p=.33) when adjusting for baseline score. In INT group, 64% found materials/activities engaging and 79% were glad to participate.

Conclusions: An intervention with educational materials supplemented by a smartphone app using a point-based financial reward structure was feasible and acceptable for teens with T1D at increased CVD risk. Further research is needed to assess durability of the intervention and its impact on CVD risk factors.

Disclosure

T. Kaushal: None. C.O. Charmant: None. L.K. Volkening: None. L.M. Laffel: Advisory Panel; Self; Roche Diabetes Care. Consultant; Self; Boehringer Ingelheim Pharmaceuticals, Inc., ConvaTec Inc., Dexcom, Inc., Insulet Corporation, Insulogic LLC, Janssen Pharmaceuticals, Inc., Lilly Diabetes, Novo Nordisk Inc., Sanofi US. M. Katz: Employee; Self; Eli Lilly and Company. Stock/Shareholder; Self; Eli Lilly and Company.

Funding

National Institutes of Health (5K12DK094721-09, P30DK036836, K23HL125976)
166-LB: Participants with KATP-Related Neonatal Diabetes (KATP-NDM) Experience More Sleep Disruption than Sibling Controls
Authors: TIAN PERSEPHONE , CHOPPARA SAMPATH , HARRIS ANASTASIA , LETOURNEAU-FREIBERG LISA R. , GREELEY SIRI ATMA W.
Published: June 2020

Background: Neonatal diabetes is rare, but most commonly caused by activating heterozygous mutations in either of the KATP channel genes KCNJ11or ABCC8. While a large fraction of those with KATP-NDM exhibit a spectrum of neurodevelopmental difficulties, patients and families also describe difficulties with sleep that has not been well-characterized.

Methods: To assess sleep duration and quality, all participants wore an actigrapher (Actiwatch® 2) for at least 7 full days and completed sleep questionnaires based on age: parents of 0-11 years old participants completed the Children’s Sleep Habits Questionnaire (CSHQ), while participants 12+ years completed the Pittsburgh Sleep Quality Index (PSQI) themselves.

Results: 12 affected individuals and 5 sibling controls completed all components of the study: 0-11 yo: 7 affected, 3 controls; 12+ yo: 5 affected, 2 controls. Affected participants had significantly less total sleep time of 433.4 minutes/night, compared to 506.2 minutes/night in controls (p = 0.003). All affected 0-11 yo individuals exhibited sleep disturbance on CSHQ (qualified as a score greater than 41). In contrast, affected 12+ yo individuals did not report significantly greater global sleep scores on the PSQI compared to controls; however, those with R201H/C mutations reported a sleep disturbance score that trended towards being significantly greater than those with V59M/A mutations (55 vs. 46; p = 0.0525).

Conclusion: Objective total sleep time was reduced in KATP-NDM, with parents reporting greater sleep difficulties than self-reported measures by older affected individuals. Neurodevelopmental supports in individuals with KATP-NDM should include assessment of sleep, but more study is required to further characterize specific disruptions that may depend on age and/or specific mutations.

Disclosure

P. Tian: None. S. Choppara: None. A. Harris: None. L.R. Letourneau-Freiberg: None. S.W. Greeley: None.

Funding

American Diabetes Association (1-17-JDF-008 to S.A.W.G.); National Institute of Diabetes and Digestive and Kidney Diseases (R01DK104942, P30DK0205950); National Center for Advancing Translational Sciences (UL1TR002389)
1670-P: Enalapril Maleate, Angiotensin-Converting Enzyme Inhibitor, Suppresses the Expression of the MHC Molecules in Mucosal Cells of the Small Intestine Leading to the Delayed Onset of Autoimmune Type 1 Diabetes Mellitus in NOD Mice
Authors: HATTORI MASAKAZU , UEDA AIKO , KATOH RYUICHI , HIRAI MASATAKA , NODA AKIHIRO , MAYANAGI KAZUYA , FURUICHI YOSHITO , HATTORI KIMIE , LUND TORBEN , KOBAYASHI KENJI , NAKAMURA YASUYUKI
Published: June 2020

Angiotensin-converting enzyme (ACE) exists in the kidney, lung and small intestine of the NOD mouse (autoimmune type 1 diabetes animal model). ACE changes Angiotensin I to Angiotensin II. ACE exists in the small intestinal epithelial cells and villi, and digests the protein antigen molecules in the small intestine. ACE plays an important role in the antigen presenting process in the mucosal immune system of the duodenum and jejunum. To examine if ACE has a role in the development of type 1 diabetes of the NOD mouse, ACE Inhibitors, enalapril maleate (EM) or captopril (CA) was dissolved in a drinking water at the concentration of 12.5μg/ml and given daily to 28-day-old NOD mice ad libitum (89 females and 70 males in CA, 72 and 52 in EM, 120 and 87 in water control group, respectively). The animals were screened for the development of diabetes twice a week for 7 months and subjected to the Life Table analysis. The incidence of diabetes in our NOD/Kmc colony is 83% in females and 40% in males at 210 days of age. The EM-treated NOD mice showed a significant delay of the onset of diabetes at 120 days of age in comparison with the controls (25% vs. 45% in females, P=0.002; 0% vs. 8% in males, P=0.037). The CA treatment was ineffective to delay the onset of diabetes. The histological examination of the pancreata showed that the EM-treated females had more islets without lymphocytic infiltration than the water-control females (mean number of undamaged islets±SD: 11.1±8.5 in EM vs. 1.9±2.5 in Control, P=0.009). The undamaged islets weighed 0.772±0.383 in EM and 0.441±0.386 in water-control (mg: mean±SE). The mRNA expression of MHC K and A genes was suppressed in the duodenum and jejunum of the NOD mice by EM- or CA-water for 14 days. Flow cytometric analysis showed suppression of the MHC K and I-A expression in the pancreatic lymphocytes of the EM- and CA-treated mice in comparison with the control mice.

Disclosure

M. Hattori: None. A. Ueda: None. R. Katoh: None. M. Hirai: None. A. Noda: None. K. Mayanagi: None. Y. Furuichi: None. K. Hattori: None. T. Lund: None. K. Kobayashi: None. Y. Nakamura: None.
1675-P: Adipocyte Adaptive Immune Cell Function and Exhaustion Contribute to the Drop in Adipose Tissue (AT) Regulatory T-Cells (Tregs) in Human Obesity
Authors: BRADLEY DAVID , BLASZCZAK ALECIA M. , SMITH ALAN , JALILVAND ANAHITA D. , WRIGHT VALERIE P. , WYNE KATHLEEN , NORIA SABRENA , JOSEPH JOSHUA , LIU JOEY Z. , HSUEH WILLA
Published: June 2020

Background: AT Tregs are decreased in obese mice. We have previously shown that preventing this decline improves insulin sensitivity, despite persistent obesity, underscoring a key role for AT Tregs in systemic metabolism. Therefore, we sought to examine AT Treg changes in human subjects and elucidate potential mechanisms responsible for these changes.

Methods: We obtained visceral (VAT) and subcutaneous adipose tissue (SAT) at elective surgery in 54 obese and 18 lean subjects, and SAT via liposuction in 15 lean subjects before and after 2 weeks high fat diet (HFD).

Results: Obese individuals had 67% less Treg abundance in VAT (p<0.001) and 79% in SAT (p<0.001); Tregs as %CD4+ cells correlated with insulin sensitivity and inversely with BMI. Subjects ingesting a HFD experienced a 50% drop in SAT Tregs (p<0.001), which correlated with decreased insulin sensitivity by clamp. To understand this drop, we next performed gene expression analyses on isolated adipocytes, AT T cells, and VAT Tregs. Obese adipocytes had profound increases in major histocompatibility class II (MHCII) genes, but decreases in fatty acid oxidation and mitochondrial genes, suggesting a functional switch from a primary metabolic to an adaptive immune cell. These changes were associated with decreased AT Treg abundance, and increased insulin resistance and BMI. T cells revealed increased Tbet, a proinflammatory CD4+ Th1 cell marker, and decreased FOXP3, a Treg marker, consistent with our demonstration that human adipocytes can present antigen to activate CD4+ Th1 cells. Obese vs. lean VAT Tregs also had a 3-fold (p<0.05) increase in the T cell exhaustion marker, program cell death protein-1 (PD-1), and a 75% (p<0.05) decrease in CD127, which is attenuated in exhausted T cells.

Discussion: Thus, human adipocyte immune cell activity, combined with Treg exhaustion, contributes to the drop in AT Tregs and strongly affects metabolism.

Disclosure

D. Bradley: None. A.M. Blaszczak: None. A. Smith: None. A.D. Jalilvand: None. V.P. Wright: None. K. Wyne: Advisory Panel; Self; Novo Nordisk Inc. Research Support; Self; Sanofi. S. Noria: None. J. Joseph: None. J.Z. Liu: None. W. Hsueh: None.

Funding

American Diabetes Association (1-16-ICTS-049 to W.H.); National Institutes of Health (KL2TR001068, R01HL135622)
1686-P: Brown Adipose Tissue as a Novel Site for Islet Transplantation
Authors: BARRA JESSIE , KEPPLE JESSICA , TSE HUBERT M. , HUNTER CHAD S.
Published: June 2020

Type 1 diabetes (T1D) results in hyperglycemia, increased risk for secondary complications, and life-long dependence on exogenous insulin. Islet transplantation is a promising alternative to insulin therapy for T1D treatment. However, long-term function of islets transplanted into the FDA approved hepatic portal vein remains low, with much of the islet mass being lost early after transplantation due to immune responses and drug toxicity. These challenges have prompted a search for alternative transplantation sites that are readily accessible, immune-privileged, offer graft retrievability, and promote islet survival. A novel site that exhibits these traits is brown adipose tissue (BAT), which is highly vascularized, innervated, and contains immunomodulatory immune cells. BAT functions to maintain thermogenesis and can regulate metabolic homeostasis. We hypothesize that islet engraftment in BAT can restore euglycemia in diabetic mice, promote revascularization, and delay immune rejection. Syngeneic transplantation of 250 NOD.scid islets into the BAT of streptozotocin (STZ)-treated diabetic NOD.scid mice restored euglycemia for over two months, similar to islets transplanted under the pre-clinical kidney capsule transplant site. Islet function was also comparable across transplant groups as measured by a glucose tolerance test. BAT thermogenic function during a cold challenge showed no difference in cold tolerance after transplantation. Histology and mRNA analysis revealed BAT engrafted islets expressed islet hormones, functional islet transcription factors, and CD31+ vascularization at the islet graft site. Overall, our data suggest BAT is a novel and efficacious site for islet transplantation. Future islet transplant studies will determine if the inherent properties of BAT can extend the longevity of transplanted islets by investigating the immunomodulatory capacity of BAT-resident mesenchymal stem cells and immune cells, compared to current transplantation sites.

Disclosure

J. Barra: None. J. Kepple: None. H.M. Tse: None. C.S. Hunter: None.

Funding

National Institute of Diabetes and Digestive and Kidney Diseases (R01DK099550); JDRF (SRA-2016-270-S-B, 2-SRA-2019-692-S-B); National Institute of General Medical Sciences (T32GM008111)
1700-P: Exogenous a1-Antitrypsin A Enhances Insulin Sensitivity in Mice Fed a High-Fat Diet by Attenuation of Neutrophil Infiltration in Epididymal Fat
Authors: D’SOUZA RANDALL F. , WOODHEAD JONATHAN S.T. , MASSON STEWART W. , JAMES SAMUEL L. , HEDGES CHRISTOPHER , MERRY TROY L.
Published: June 2020

Neutrophil elastase (NE) is a serine protease expressed by neutrophils which is inhibited endogenously by α1-Antitrypsin A (AAT). Obesity is associated with increased plasma NE:AAT ratios and adipose tissue NE accumulation, which may drive obesity-associated metabolic dysfunction. Exogenous AAT is now an FDA approved treatment for AAT deficiency, therefore we investigated whether AAT treatment may also have potential therapeutic benefits for diet induced metabolic dysfunction. Standard Chow and high-fat diet (HFD) fed male C57Bl6 mice were randomized to receive 3x weekly IP injections of either AAT (2mg) or vehicle (PBS) for 10 weeks. Chow fed mice treated with recombinant AAT showed no differences in plasma NE, body weight or metabolic phenotype compared to vehicle treated control mice. However, during HFD feeding AAT treatment attenuated increases in plasma NE and white adipose tissue (WAT) NE and neutrophil accumulation without affecting circulatory neutrophil levels or body weight. Consistent with NE knockout mice being partially protected from HFD glucose intolerance, treatment of HFD fed mice with AAT enhanced whole body insulin sensitivity which was attributed to higher insulin-dependent p-AktSer473 and reduced inflammation markers in WAT but no other peripheral tissues. Treatment of 3T3L1 adipocytes with recombinant NE impaired insulin-stimulated glucose uptake andp-AktSer473, suggesting that inhibition of NE in WAT is the primary mechanism through which AAT treatment enhances insulin sensitivity. Collectively, our data suggests AAT may play a potential role in mitigating diet-induced neutrophil infiltration in WAT insulin resistance.

Disclosure

R.F. D’Souza: None. J.S.T. Woodhead: None. S.W. Masson: None. S.L. James: None. C. Hedges: None. T.L. Merry: None.

Funding

Health Research Council of New Zealand
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<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<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 <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 <30) no IR and obese (BMI ≥30) IR (HOMA-IR>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<0.05). A positive correlation was observed between AT expression of Tbxa2r and Tbxas1 (Spearman’s r=0.49, n=35, P<0.01). We noted a weak positive correlation between AT Tbxa2r and HOMA-IR (Spearman’s r=0.31, n=35, P<0.07). A positive correlation was also noted between AT Tbxas1 and HOMA-IR (Spearman’s r=0.42, n=37, P<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)