bluuebunny/crossref_metadata_2025 huggingface dataset:
1634-P: Gotta LADA? Identifying Differences in Adults with Latent Autoimmune Diabetes and Type 2 Diabetes to Improve Screening and Diagnosis
Authors: LEE MICHELLE N.
Published: June 2020

Introduction: Latent autoimmune diabetes in Adults (LADA) represents up to 14% of adult diabetes. Compared to type 2 diabetes mellitus (T2DM) patients, LADA is believed to be diagnosed more acutely in younger patients with a lower body mass index (BMI), worse hemoglobin A1Cs (HbA1C), and lower triglycerides (TG). This study was done to examine for actual clinical differences between LADA and T2DM.

Methods: A retrospective case-control study was performed on adults with LADA and randomly matched with T2DM adults. Patients were matched based on gender and age (within 5 years) at time of diagnosis at an allocation ratio of 1:3 using the Military Health System Diabetes CarePoint Registry. Retrospective data were pulled at time of diagnosis to included ethnicity, BMI, HbA1C, lipids, TSH, the presence of symptoms, and medical histories. Univariate analyses were done for each variable followed by a multivariate analysis to determine the best overall model and control for confounding.

Results: In univariate analysis, BMI (P < 0.001), TG (P = 0.003), and HDL (P = 0.009) were significant predictors of LADA compared to T2DM at time of diagnosis. None of the acute symptoms, autoimmune disorders, or other medical history was found to be statistically significant. In the multivariate model, Caucasians were more likely to be LADA (OR = 14.1; 95% CI, 1.34 to 146.2, P = 0.027). Low BMI and low TG levels were found to interact inversely (P = 0.049) with the odds of being a LADA. However, low BMI effect was only significant with TG levels under 350 mg/dl, and low TG effect was only significant in those with BMI <28. The final model correctly classified 86% and 94.4% of the case-controls and controls.

Conclusion: Statistically significant differences were found between BMI, TG and HDL levels at time of diagnosis between LADA and T2DM adults, similar to those previously reported. Strongest differences were noted between BMI and TG levels, which may assist in diagnosis of LADA patients.

Disclosure

M.N. Lee: None.
1640-P: Common and Ethnic-Specific Molecular Networks and Drivers of Insulin Resistance in African and European Ancestry Individuals
Authors: XU PENG , WANG MINGHUI , SHARMA NEERAJ K. , COMEAU MARY , CIVELEK METE , LANGEFELD CARL D. , ZHANG BIN , DAS SWAPAN K.
Published: June 2020

Our understanding of how genetic variants influence molecular regulatory networks in glucose responsive tissues, and in turn affect cellular processes related to insulin resistance (IR) in different ethnic groups, remains incomplete. We employ a network modelling approach to integrate measures of insulin sensitivity, transcriptomic data in the adipose and muscle tissues, and genetic data from African Americans (AAs) in the AAGMEx cohort (N=256). Data from European ancestry (EA) individuals from AREA (N=99) and METSIM (N=770) cohorts are used as contrast. Multiscale Embedded GEne coexpression Network Analysis (MEGENA) in AAs identifies 167 and 63 transcript subnetworks (modules) enriched for Matsuda index and SI-correlated genes in adipose and muscle, respectively. Among these IR-associated modules, 11 in adipose and 6 in muscle, are enriched for the cis-eSNP genes. Bayesian probabilistic causal networks (BN) are constructed and subsequently used to identify key network drivers. Integration of MEGENA and BN in AAs identifies 99 and 39 key regulators for IR-associated adipose and muscle modules, respectively. Among the IR-associated modules in AAs, 23 in adipose and 5 in muscle are strongly preserved in the respective networks in the EA cohorts. Top 3 IR-associated preserved adipose modules are enriched for immune system, mitochondria and hormonal response and these modules are potentially regulated by KYNU, LDHD and ENO1, respectively. We identify 50 and 24 IR-associated but AA-specific modules (not preserved in EAs) in adipose and muscle, respectively. Conversely, we find 28 IR-associated but EA-specific modules in adipose. Ethnic group specific and shared modules reveal novel molecular mechanisms for IR. Enrichment of cis-eSNP genes in the network neighborhoods of key drivers suggest that regulatory SNPs may configure the networks by modulating transcript expression in adipose and muscle tissues, and are likely causal determinants for IR.

Disclosure

P. Xu: None. M. Wang: None. N.K. Sharma: None. M. Comeau: None. M. Civelek: None. C.D. Langefeld: None. B. Zhang: None. S.K. Das: None.

Funding

National Institutes of Health (R01DK118243, R01DK090111)
1645-P: Polygenic Risk Score for Prediction of Complications in Men and Women with Type 2 Diabetes
Authors: TREMBLAY JOHANNE , ATTAOUA REDHA , HALOUI MOUNSIF , TAHIR RAMZAN , LONG CAROLE , HIZEL CANDAN , CHALMERS JOHN , HARRAP STEPHEN , WOODWARD MARK , HAMET PAVEL
Published: June 2020

Introduction: We assessed the performance of our newly developed polygenic risk score (PRS) to predict microvascular and macrovascular complications of type 2 diabetes (T2D) in men and women. The PRS is composed of 600 common genomic variants associated to diabetes, cardiovascular and renal diseases and their key risk factors selected from summary statistics of meta-analyses of published genome-wide association studies performed in over 1.2 million of individuals. The performance of the polygenic model was assessed by c-statistics in 4098 genotyped participants of European descent of the ADVANCE trial (46.4% women) followed during a period of five years.

Methods: The logistic regression model that included the PRS adjusted for the principal component (PC1) of genetically determined ancestry, age at diagnosis and T2D duration, and treatment assignment, did not include any clinical or outcome data.

Results: The discrimination between cases (having a specific complication) from controls (free of this complication) at entry in ADVANCE had AUCs for microvascular complications of 0.63 (0.60-0.65) in men and 0.66 (0.63-0.69) in women, sex differences p = 0.07. AUCs for macrovascular complications were 0.56 (0.54-0.58) in men and 0.57 (0.54-0.61) in women; p = 0.41. The AUCs for prediction of incident cases, defined as having an outcome during the ADVANCE trial (free of outcome at baseline) compared to controls that did not have a specific outcome at any time during the study, were for microvascular events 0.66 (0.63-0.70) in men and 0.71 (0.66-0.77) in women; p = 0.15. AUCs for macrovascular events were 0.65 (0.62-0.68) and 0.72 (0.68-0.76) respectively, p = 0.01. AUC for prediction of cardiovascular death occurring during the trial was 0.71 (0.67-0.75) in men and 0.77 (0.72-0.82) in women; p = 0.04.

Conclusion: Our polygenic model demonstrated an overall better performance in women than in men and a better prediction capacity in individuals free of previous events in both sexes.

Disclosure

J. Tremblay: Research Support; Self; Servier. Stock/Shareholder; Self; OPTITHERA. R. Attaoua: None. M. Haloui: None. R. Tahir: None. C. Long: None. C. Hizel: None. J. Chalmers: None. S. Harrap: None. M. Woodward: Consultant; Self; Amgen, Kyowa Hakko Kirin Co., Ltd. P. Hamet: Research Support; Self; Servier. Stock/Shareholder; Self; OPTITHERA.

Funding

Genome Quebec; Canadian Institutes of Health Research; MEIE; CQDM; Opti Thera; Servier, Canada Research Chair in Predictive Genomics
1649-P: Effect of Fasting Insulin-Derived Gene Variant Clusters on Cardiometabolic Traits
Authors: SEVILLA MAGDALENA , UDLER MIRIAM , KIM HYUNKYUNG , HSU SARAH , MEIGS JAMES B. , MANNING ALISA
Published: June 2020

Background: Fasting insulin concentrations reflect insulin resistance, which increase is associated with subsequent risk of heterogeneous cardiometabolic traits, including coronary artery disease (CAD), blood pressure (BP), estimated glomerular filtration rate (eGFR), BMI and lipid traits (TG, HDL, and LDL). We clustered insulin-associated genetic variants to define heterogeneous insulin resistance domains and tested whether these were associated with different cardiometabolic traits.

Methods: We studied subjects of European Ancestry with genetic and clinical data available (N=18,127) in the Partners Biobank. We applied a soft clustering to 56 genome-wide association study (GWAS) fasting insulin genetic variants and 25 fasting insulin-related traits. We generated weighted genetic risk scores (GRS) for each cluster (alleles were aligned in the direction of increased fasting insulin effect). Then we aimed to identify clinical consequences between the clusters and cardiometabolic outcomes including CAD, SBP, DBP, eGFR, BMI, TG, HDL, and LDL. We tested the hypothesis that different genetic insulin domains will be cross-sectionally associated with some or all of these cardiometabolic traits.

Results: We obtained three novel clusters of genetic variants. Each cluster was represented by a set of traits and a set of loci. The first represented VF and SAT, with loci near DLG2, FAM169B and, RGS12 genes, and its GRS was positive associated with CAD (p=0.004). The second cluster represents insulin sensitivity and lipid traits with loci near IRS1, ARRDC4 and, SNTG1, and its GRS was associated with lower TG (p=0.00001), and higher HDL(p=0.007). The last cluster represents proinsulin with loci near FABP2 and, PCAT5. No associations were found with this cluster.

Conclusion: These results reveal different genetic insulin domains indicating different mechanisms for cardiometabolic traits associated with fasting insulin.

Disclosure

M. Sevilla: None. M. Udler: None. H. Kim: None. S. Hsu: None. J.B. Meigs: Consultant; Self; Quest Diagnostics. A. Manning: None.
165-OR: High- and Moderate-Intensity Exercise Training Increased Skeletal Muscle Acylcarnitine and Phospholipid Abundance in Obese Adults
Authors: SCHLEH MICHAEL W. , RYAN BENJAMIN J. , LUDZKI ALISON , GILLEN JENNA B. , HOROWITZ JEFFREY F.
Published: June 2020

The primary aim of this study was to determine the impact of high-intensity interval training [HIIT] and moderate-intensity continuous training [MICT] on skeletal muscle lipidomic profile in obese adults. 17 obese adults (BMI = 34±3 kg·m-2; age = 31±6 years) completed 12 weeks of either HIIT (10 x 1 min @ 90%HRmax + 1 min recovery between intervals; n=8) or MICT (45 min steady-state exercise at 70% HRmax; n=9). Subjects exercised 4d/week and body weight was strictly maintained to assess the direct effects of exercise, independent of changes in body weight or fat mass. Skeletal muscle samples were collected from the vastus lateralis after an overnight fast both before training and 4 days after the last exercise session (to wash out the acute effects of exercise). Using shotgun lipidomics (LC MS/MS) we detected 734 lipid species from 26 different classes. Neither MICT nor HIIT significantly altered abundance of the primary muscle acylglycerides (tri- and di-acylglyceride) or ceramide abundance. Muscle acylcarnitine abundance increased after both MICT and HIIT (main effect, P = 0.04), specifically polyunsaturated acylcarnitines (P = 0.03). We also found phosphatidylcholine (PC) increased after training in both groups (main effect, P = 0.03), while the increase in phosphatidylethanolamine (PE) was greater after HIIT compared with MICT (P = 0.01). When normalized to cardiolipin (which is found almost exclusively in the inner mitochondrial membrane), the increased abundances of PC and PE were no longer apparent. Therefore, the training-induced increase in these phospholipids may largely reflect increased mitochondrial biosynthesis with training. In contrast, the observed increase in polyunsaturated acylcarnitines may represent an important adaptive response in the coordination of fatty acid metabolism in skeletal muscle after training. Overall, changes in muscle lipid profile were surprisingly similar in HIIT and MICT.

Disclosure

M.W. Schleh: None. B.J. Ryan: None. A. Ludzki: None. J.B. Gillen: None. J.F. Horowitz: None.

Funding

National Institutes of Health (R01DK077966, P30DK089503, F32DK117522, U24DK097153, UL1TR002240); Canadian Institutes of Health Research (DFS146190)
1651-P: Low Leg Fat and Ethnicity Are Predictors for Genetic Insulin Resistance in a Multiethnic Sample of Early Pubertal Children
Authors: FOWLER LAUREN A. , FERNANDEZ JOSE R. , GOWER BARBARA
Published: June 2020

In the United States, Hispanic- and African-Americans (HA and AA, respectively) have been shown to have a higher prevalence of type 2 diabetes than their European-American (EA) counterparts. A recent genome-wide association study revealed that genetic variants linked to insulin resistance (IR) phenotypes were associated with lower levels of leg fat mass. We investigated whether leg fat deposition and genetic risk for IR differed by ethnicity in a cross-sectional study of 82 AA, 75 HA, and 83 EA children aged 7-12 years. Participants were genotyped with the Metabochip array for 46 single nucleotide polymorphisms (SNPs) associated with IR, and a genetic risk score (GRS) was developed using the weighted sum of the risk alleles. An intravenous glucose tolerance test and minimal modeling were used to derive the insulin sensitivity index (SI), while body composition was measured by DXA. Multiple linear regression was used to compare differences among ethnicity after adjustment for sex, age, Tanner stage, and socioeconomic status. Leg fat models were also adjusted for total body fat and BMI percentile, while SI models were adjusted for adiposity. Mean leg fat deposition relative to total body fat was significantly lower in HA compared to EA and AA (P < 0.001 for both comparisons). Additionally, GRS independently predicted both leg fat (β = -0.34 (0.13), P = 0.012) and SI (β = -1.33 (0.59), P = 0.027) in HA. In contrast, GRS was not an independent predictor of either outcome in AA or EA. These results suggest that HA may have a genetically impaired ability to store lipid in peripheral adipose tissue depots, consequently leading to deposition in ectopic regions and IR. Our findings highlight a potential mechanism contributing to the higher rate of type 2 diabetes observed in Hispanic-American populations.

Disclosure

L.A. Fowler: None. J.R. Fernandez: None. B. Gower: None.

Funding

National Institutes of Health (R01DK067426); National Center for Research Resources (M01RR000032); University of Alabama at Birmingham Nutrition Obesity Research Center (P30DK056336, T32DK062710); University of Alabama at Birmingham Diabetes Research Center (P60DK079626)
1653-P: Association between Genetic Admixture Estimates for Five Ancestral Populations and Diabetes-Related Traits in Pacific Islanders
Authors: HSUEH WEN-CHI , KUMAR PANKAJ , SAFABAKHSH SAIED , JONES LOIS , CURRAN JOANNE , KNOWLER WILLIAM C. , NELSON ROBERT G. , HANSON ROBERT L.
Published: June 2020

Ecological studies have shown different risks for diabetes (DM) among many ethnic groups, but whether they are due to genetic or non-genetic factors is hard to dissect. We conducted a community-based study aimed at identifying risk factors for DM and related traits in Pacific Islanders from Guam and Saipan. We analyzed the genetic structure of our sample and estimated individual-level admixture using genome-wide SNP data (49,300 variants). We found that genetic ancestry largely derived from 5 populations, representing Marianas Islanders (MI) (mean % heritage, or μ=43%), East Asians (EA, μ=22%), Micronesians (MC, μ=19%), Europeans (EU, μ=13%), and Melanesians (ML, μ=3%). We then tested the association of ancestry estimates with DM, fasting glucose and fasting insulin levels in study participants (n=1,853). Covariates included age, sex and end-stage kidney disease. For fasting insulin, only nondiabetic subjects were used in analyses. All 3 traits were associated with genetic ancestry (p<e-4). EA was associated with lowest DM risk and lowest mean levels of glucose and insulin, while DM risk and fasting glucose were highest in MI. DM risk (measured as odds ratio [OR]) for MI vs. EA was 6.9 (95% CI=3.3-14.7). Mean difference (β) in fasting glucose and insulin for MI vs. EA was 0.83 and 0.76 s.d. units, respectively. MI had higher DM risk compared to MC (OR=1.79, p=0.022), but similar risk to EU and ML. MI had higher mean glucose vs. MC (β=0.23 s.d. units, p=0.014). However, MI had comparable insulin levels to EU and MC, but lower than ML (β=-1.37 s.d. units, p=0.0046).

In summary, there were large and statistically significant differences in DM-related traits among Pacific Islanders with different genetic ancestral backgrounds. Although genetic ancestry estimates may still be confounded by shared environmental factors, the present findings suggest that admixture mapping may be a potentially powerful approach for identifying unique DM loci in Pacific Islanders.

Disclosure

W. Hsueh: None. P. Kumar: None. S. Safabakhsh: None. L. Jones: None. J. Curran: None. W.C. Knowler: None. R.G. Nelson: None. R.L. Hanson: None.
1654-P: Deletion of the Mammalian Indy Homolog (Slc13a5) Improves Hepatic Insulin Sensitivity through Vagal Nerve Signaling
Authors: KURZBACH ANICA , SCHELL MAREIKE , WILLMES DIANA M. , EL-AGROUDY NERMEEN , KLEINRIDDERS ANDRE , BIRKENFELD ANDREAS L.
Published: June 2020

Background: INDY (I’m Not Dead Yet) is a plasma membrane citrate transporter and is highly expressed in liver and brain. In mammals, whole body deletion of the coding gene (mIndy, Slc13a5) increased energy expenditure and protected mice from diet-induced obesity and insulin resistance. Generation of neuronal mIndy-KO (NINKO) mice revealed improved insulin sensitivity (IS) in these mice, mediated through better hepatic IS. Gene expression studies in wildtype C57Bl/6 mice revealed high expression of mIndy in the hypothalamus (HTM), which is the main brain area regulating hepatic glucose metabolism. One mechanisms is the regulation through AMPK. Reduced hypothalamic AMPK phosphorylation is known to reduce hepatic glucose output, probably mediated via vagal nerve signaling.

Hypothesis: Hepatic glucose production is regulated via mIndy expression in the HTM.

Methods: Hyperinsulinemic-euglycemic clamp studies were performed to assess IS after hepatic vagotomy of NINKO mice. NestinCre+ controls were sham-denervated. Ex vivo brain slices of C57Bl/6 mice and the neuronal hypothalamic cell line CLU183 were acutely stimulated with 1 mM sodium citrate to investigate the effect of citrate on the brain and neurons.

Results: Acute stimulation of brain slices and CLU183 cells with citrate decreased cellular respiration (-19.7%, p≤0.01), ATP production (-37.7%, p≤0.01) and increased AMPK phosphorylation (+24.7%, p≤0.001). In line with that, AMPK phosphorylation in the HTM of NINKO mice was significantly reduced (-68.1%, p≤0.05). With hepatic branch vagotomy, no differences in hepatic IS could be observed anymore (suppression of basal hepatic glucose output (%); NestinCre+: 100.0±27.2, NINKO: 99.4±8.8).

Conclusion: These data suggest that neuronal mIndy is a critical regulator of glucose homeostasis in mammals, probably regulated via AMPK phosphorylation in the HTM and vagal nerve signaling. Further studies will address the exact mechanisms involved in the effect.

Disclosure

A. Kurzbach: None. M. Schell: None. D.M. Willmes: None. N. El-Agroudy: None. A. Kleinridders: None. A.L. Birkenfeld: None.
1659-P: Nutrients Consumption Dependent Association of the Glucagon-Like Peptide-1 Receptor Gene Polymorphism with Insulin Secretion
Authors: NISHIYA YUKI , DAIMON MAKOTO , MURAKAMI HIROSHI , MURABAYASHI MASAYA , MIZUSHIRI SATORU , FUJITA TOMOYUKI , MATSUHASHI YUKI
Published: June 2020

Objective: Since type 2 diabetes (DM) is a life-style related disease, life-style should be considered, when association between genetic factors and DM are examined. However, most studies did not examine genetic associations with such consideration, as the case of glucagon-like peptide-1 receptor (GLP-1R) gene. We examined the association in consideration with the interaction between the gene polymorphism and various nutrient factors.

Research Design and Methods: Among participants of the population-based Iwaki study of Japanese held in 2014-2017, those with information of the genotype of GLP-1R polymorphism (db SNP ID: rs3765467: A/G)(p.Alg131Gln) as well as nutrients consumed (n=1817) were included. The following individuals were also excluded: 64 on medication for DM, and 52 with FBG levels below 63 mg/dl or over 140 mg/dl (to evaluate HOMA indices precisely). After these exclusions, 1,560 individuals (587 men, 973 women) aged 53.3± 16.1 years were included in the study.

Results: Though not significant, insulin secretion indices assed by homeostasis model assessment (HOMA- ß) in subjects with the GG genotype tended to be lower than in those with the AA+AG genotypes in most groups stratified into tertiles based on their daily nutrients consumptions (high, middle, and low groups). The stratification also showed that the genotype GG was a significant risk for a decreased insulin secretion (HOMA-ß ≤ 30) even after adjustment for multiple factors (age, BMI, drinking alcohol) only in the highest tertiles of energy, protein and carbohydrate consumption in men (odds ratios (95% CI) in high energy, protein and carbohydrate consumption groups: 3.95 (1.03-15.1), 15.83 (1.58-158.9), and 4.23 (1.10-11.2), respectively).

Conclusions: The GLP-1R gene was associated with a decreased insulin secretion dependently of nutrients consumption, which indicates interaction between GLP-1R and nutrient factors on pathophysiology leading to DM.

Disclosure

Y. Nishiya: None. M. Daimon: None. H. Murakami: None. M. Murabayashi: None. S. Mizushiri: None. T. Fujita: None. Y. Matsuhashi: None.
1661-P: NHG-KTPH Monogenic Diabetes Registry: Understanding Monogenic Diabetes in a Multiethnic Asian Population in Singapore
Authors: ANG SU FEN , TAN CLARA SI HUA , KON YIN CHIAN , XIA LIAN , LIM SU CHI
Published: June 2020

Introduction: Monogenic diabetes (also known as maturity-onset diabetes of the young or MODY) is a rare genetic disorder with an undetermined prevalence in Singapore. The NHG-KTPH Monogenic Diabetes Registry was set up in mid-2017 to capture longitudinal data of individuals genetically diagnosed with monogenic diabetes to study their prevalence and disease trajectories.

Methods: Patients with clinical phenotype suggestive of monogenic diabetes i.e., diabetes onset =<45 years old, BMI <32.5 kg/m2 and GAD autoantibody-negative were recruited and subjected to genetic testing comprising of next-generation 16-MODY gene panel sequencing, mt.3242A>G TaqMan genotyping and multiplex ligation-dependent probe amplification (MLPA) for 4 common MODY genes. Genetic variants annotated as likely pathogenic/pathogenic according to ACMG guidelines were validated using Sanger sequencing. Individuals with such variant(s) were included in the Registry. EQ-5D-5L instrument was also administered for quality of life assessment.

Results: Among 171 patients who were subjected to MODY genetic testing, 26 (15%) were found to harbor likely pathogenic/pathogenic variants. 93% of these variants were found in common MODY genes (HNF1A, HNF4A, GCK, HNF1B, MT-TL1) that had important clinical implications. Biomarkers such as C-peptide, hs-CRP and HDL were significantly different in those with likely pathogenic/pathogenic variants than those without.

Discussion: Monogenic diabetes is present in 15% of our study participants with young-onset diabetes, which is greater than the reported 5% in UK. Clinical demographics and biomarkers can be further evaluated to improve the pick-up rate of monogenic diabetes among young-onset diabetes, with specific calibration applied to different subtypes of monogenic diabetes. This will improve cost-effectiveness of genetic testing and facilitate implementation of precision medicine for individuals with monogenic diabetes.

Disclosure

S. Ang: None. C. Tan: None. Y. Kon: None. L. Xia: None. S. Lim: None.
1666-P: Increased Levels of Autophagy in a Rodent Model of Type 1 Diabetes
Authors: KARACAY CEREN , KOTZBECK PETRA , PRIETL BARBARA , HARER CLEMENS , PIEBER THOMAS
Published: June 2020

Beta-cell apoptosis is a hallmark of type 1 diabetes (T1D) and type 2 diabetes (T2D). In T2D loss of autophagy has been associated to increased apoptosis and diminished beta-cell mass. In autoimmunity, dysfunctional autophagy alters negative selection of T cells in thymus driving autoreactive immune cells into periphery. Autophagy contributes to presentation of antigens in antigen presenting cells shaping the repertoire of peptides presented to T cells. The aim of this project is to investigate the role of autophagy in the etiology of T1D. To investigate the effect of spermidine (SPD, a known inducer of autophagy) in vivo, non-obese diabetic (NOD) mice received spermidine (10 mM; n=30) or pure drinking water (n=28) from the age of 4 weeks until the age of 35 weeks or diabetes onset. Mice were analyzed for diabetes rate, autophagy markers (LC3-II to LC3-I ratio and p62) and immune cell phenotype in spleen and blood. Spermidine led to a higher diabetes rate in SPD group (80 %) compared to control group (60,7 %) with p-value of 0,026 (log-rank test). Autophagy was induced by diabetes (plasma glucose > 200 mg/dL) and by age. Autophagy levels were higher at 21-35 weeks in old diabetic animals compared to nondiabetic animals at 35 weeks and compared to young diabetic animals at 14-20 weeks (p< 0,0001, and p< 0,0001, respectively). Spermidine treatment increased autophagy levels in pancreas, but diabetic mice at 21-35 weeks still had higher autophagy levels compared to nondiabetic animals at week 35. (LC3-II/LC3-I: p < 0,05; p62: p < 0,05). Spermidine elevated the frequency of natural killer cells in spleen (p < 0,01) and blood (p < 0,01), natural killer T cells (p < 0,01), naïve CD4+ T cells (p < 0,01), naïve CD8+ T cells (p < 0,01) and central memory CD4+ T cells (p < 0,01) in blood. Our experiments indicate that autophagy is induced upon T1D and spermidine-induced autophagy might increase diabetes incidence. Immune cell phenotyping revealed that spermidine promotes immune cells potentially provoking inflammation.

Disclosure

C. Karacay: None. P. Kotzbeck: None. B. Prietl: None. C. Harer: None. T. Pieber: Advisory Panel; Self; ADOCIA, Arecor, AstraZeneca, Eli Lilly and Company, Novo Nordisk A/S, Sanofi. Research Support; Self; AstraZeneca, Novo Nordisk A/S. Speaker’s Bureau; Self; Novo Nordisk A/S, Roche Diagnostics K.K.
1668-P: Novel Mechanism of Negative Regulation of FOXP3 Expression in Autoimmune Diabetes
Authors: RAMAKRISHNAN PARAMESWARAN , DE JESUS TRISTAN J. , CENTORE JOSHUA
Published: June 2020

The NF-kappaB protein c-Rel is essential for the expression of forkhead box P3 (FOXP3), the master transcription factor that governs development and function of T regulatory cells. We found that O-GlcNAcylation of c-Rel at serine residue 350 suppresses the expression of FOXP3. Hyperglycemia-induced c-Rel O-GlcNAcylation-dependent suppression of FOXP3 expression was found in vivo in two mouse models of autoimmune diabetes; the streptozotocin (STZ)-induced diabetic mouse model and in the non-obese diabetic (NOD) mouse model. Mechanistically, we show that both hyperglycemia-induced and chemically enhanced cellular O-GlcNAcylation decreases the DNA binding ability of c-Rel at the FOXP3 promoter. Mutation of the O-GlcNAcylation site in c-Rel, (serine 350 to alanine), augments T cell receptor-induced FOXP3 expression and resists the O-GlcNAcylation-dependent repression of FOXP3 expression. This study reveals c-Rel S350 O-GlcNAcylation as a novel molecular mechanism regulating immunosuppressive FOXP3 expression in autoimmune diabetes with potential therapeutic implications.

Disclosure

P. Ramakrishnan: None. T.J. de Jesus: None. J. Centore: None.

Funding

National Institutes of Health (R01AI116730, R21AI144264)
167-LB: The Contribution of a- to ß-Cell Transdifferentiation in Gestational ß-Cell Expansion in Mouse
Authors: SZLAPINSKI SANDRA , BENNETT JAMIE , STRUTT BRENDA , HILL DAVID J.
Published: June 2020

Introduction: Pregnancy is characterized as a state of insulin resistance. To compensate for this, endocrine pancreatic β-cell mass (BCM) expansion occurs and is maximal at gestational day 18 (GD18) in mouse. There is evidence through lineage tracing of α-cells that they can replenish β-cells following β-cell loss/stress by α to β-cell transdifferentiation. In this study we sought to track the fate of α-cells during pregnancy to determine the contribution of α to β-cell transdifferentiation in gestational BCM expansion.

Hypothesis: α to β-cell transdifferentiation will be higher during pregnancy compared to a non-pregnant animal.

Materials and Methods: Glucagon-Cre/Rosa26-eYFP mice were time-mated and a non-pregnant group was age-matched to these animals. Pancreata were removed on GD9, 12, 18, and postpartum day 7 for fluorescence immunohistochemistry. Tissue sections were immunostained for insulin, YFP, glucagon, DAPI and analyzed by manual cell counting. All insulin-expressing cells were counted and separated into either islets (≥6 β-cells) or clusters (1-5 β-cells).

Results: There were more transitional cells (Insulin+YFP+Glucagon+) in clusters during pregnancy compared to a non-pregnant animal (13.31±4.53%vs.9.14±2.01%). Furthermore, there were more differentiated β-cells with an α-cell origin (Insulin+YFP+Glucagon-) during pregnancy compared to a non-pregnant animal (16.73±5.28% vs.5.79±3.27%).

Discussion and Conclusions: The data show more transitional cells during pregnancy, followed by an increase in β-cells differentiating from α-cells. Our previous experiments found that BCM expansion occurs in part due to neogenesis from β-cell progenitors located in clusters. Since there were more transitional cells localized to clusters, it is plausible that α to β cell transdifferentiation is enriched in clusters. This study provides mechanistic insights into the pathology of β-cell deficiency in pathological pregnancies such as gestational diabetes.

Disclosure

S. Szlapinski: None. J. Bennett: None. B. Strutt: None. D.J. Hill: None.

Funding

Ontario Graduate Scholarship; Lawson Foundation; St. Joseph’s Health Care Foundation
1673-P: Plasmablasts Contribute to the Development of Type 1 Diabetes via Enhancing T-Cell Cytotoxicity
Authors: YAN BI , LING QING , LU JING , ZHU DALONG
Published: June 2020

Disturbance of innate and adaptive immune systems is responsible for β-cell destruction in type 1 diabetes (T1D). Although increasing evidence indicated a crucial role for B cells in disease pathogenesis, exactly how B-cell subsets contribute to T1D remains unclear. This study aimed to evaluate the potential role of B-cell subset in the development of T1D. We enrolled 56 people with T1D, including 8 people receiving mesenchymal stromal cell (MSC) treatment, 22 people with T2D, and 26 healthy controls. ELISPOT assay was used to assess the role of B-cell subset in activation of diabetogenic T cells. NOD mice and adoptive transfer assays were utilized to study the role of B-cell subset in T1D in vivo. Plasmablasts, but not naïve, unswitched or switched memory B cells, were increased in patients with recent-onset T1D, compared with those with long-term T1D, T2D and healthy controls. In patients with recent-onset T1D, plasmablast number negatively correlated with fasting C-peptide and area under the curve of C-peptide. Plasmablasts decreased in line with an improvement of residual β-cell function 3 months after MSC treatment. Compared with other B-cell subsets, plasmablasts expressed a high level of CD86, which negatively correlated with the residual β-cell function while positively correlated with the number of islet autoantibodies. ELISPOT assay further showed that plasmablasts isolated from participants with T1D induced a dramatic increase of interferon-γ secretion in GAD65 stimulated T cells. Compared with euglycemic NOD mice, the number of plasmablasts was increased in the spleen, pancreatic lymph nodes, and islets of diabetic NOD mice. Moreover, adoptive transfer of plasmablasts mixed with T cells from diabetic NOD mice into NOD/SCID mice accelerated the development of T1D. These data firstly demonstrated that plasmablasts play a vital role in immune disturbance, further expanding the knowledge of T1D pathogenesis. Plasmablasts may serve as a novel therapeutic target in T1D.

Disclosure

B. Yan: None. Q. Ling: None. J. Lu: None. D. Zhu: None.
1676-P: Immune Responses to Insulin B:9-23–Related Peptides Were Observed in Fulminant Type 1 Diabetes
Authors: OIKAWA YOICHI , SATOMURA ATSUSHI , HAISA AKIFUMI , SUZUKI SEIYA , SHIMADA AKIRA
Published: June 2020

Most type 1 diabetes (T1D) is considered to be a T helper (Th)-1 type anti-islet autoimmune disease. Recently, we reported that the immune responses to insulin B9-23-related peptides were strengthened in T1D. Meanwhile, fulminant T1D (FT1D), a novel subtype of T1D characterized by extremely rapid onset and complete deficiency of insulin due to destruction of pancreatic β-cells, has been believed to be caused by viral infection as the etiological mechanism; but, whether the etiology associates with anti-islet immune reactions or not remains unknown. This study aims to investigate whether the immune responses to insulin B9-23-related peptides associate with FT1D. Peripheral mononuclear cells (MNCs) were obtained from 72 patients with acute-onset T1D (AT1D; age, 46.2 ± 14.7 y/o; disease duration (DD), 8.8 ± 10.7 years), 15 patients with FT1D (age, 46.1 ± 14.2 y/o; DD, 4.7 ± 8.2 years) and 25 patients with type 2 diabetes (T2D; age, 63.3 ± 13.1 y/o; DD, 17.0 ± 10.2 years). The MNCs were stimulated by insulin B9-23, B10-24, B11-25 and B12-26 for 24 hours. Subsequently, ELISpot assay was performed for investigating a frequency of interferon (IFN)-gamma (g)-producing MNCs. The maximum number of IFN-g spots in the peptides-related data of each subject was used for analysis and expressed by the number of spot-forming cells (SFCs) per 2.5×105 cells. As a result, the spot number was significantly higher in AT1D (2.6 ± 3.0 SFCs) and FT1D (2.5 ± 2.6 SFCs) as compared to T2D groups (1.0 ± 1.1 SFCs) (P <0.05 by t-test), suggesting that Th1-type immune responses to insulin B9-23-related peptides were observed in FT1D, and that the degree of response was comparable in the two groups, suggesting the association between anti-islet autoimmunity and FT1D. This cross-sectional study could not reveal an association between the Th1-type immune responses and disease activity which may be inferred from the residual serum C-peptide levels or disease duration, which warrant further investigation by accumulating more subjects.

Disclosure

Y. Oikawa: None. A. Satomura: None. A. Haisa: None. S. Suzuki: None. A. Shimada: Advisory Panel; Self; Astellas Pharma Inc. Speaker’s Bureau; Self; Eli Lilly Japan K.K., Novo Nordisk Inc., Sanofi-Aventis.
168-OR: The Inverse Association between Cardiorespiratory Fitness and Inflammation Is Modified by Plasma Levels of Omega-3 Polyunsaturated Fatty Acids
Authors: FARLEY GABRIELLE , RIGGS DANIEL W. , BHATNAGAR ARUNI , HELLMANN JASON
Published: June 2020

Moderate intensity exercise has been shown to prevent the development and progression of chronic inflammatory diseases, including type 2 diabetes. Likewise, physical fitness is associated with reduced inflammation, morbidity, and mortality. Nonetheless, factors that contribute to the anti-inflammatory effect of physical fitness remain largely undefined. Using data collected from 437 participants in the 2003-2004 National Health and Nutrition Examination Survey, we assessed how the omega-6/omega-3 fatty acid ratio (ω-6/ω-3) modifies the relationship between cardiorespiratory fitness (VO2max) and inflammation (C-reactive protein; CRP). Participants were 45% female with an average age of 32.9 years and with a BMI of 27.7 kg/m2. In adjusted models for CRP, we observed significant interactions between VO2max and ω-6/ω-3 quartiles. Participants with the highest quartile of ω-6/ω-3 showed a positive association between VO2max and CRP levels. Conversely, the lowest quartiles of ω-6/ω-3 were negatively associated with VO2max and CRP, ranging from -22.4% to -33.7% CRP per 10 ml/kg/min VO2max compared with the highest ω-6/ω-3 quartile (interaction p-value= 0.0149). This negative relationship was strengthened when alternatively modeling the interaction between total ω-3 levels and VO2max (interaction p-value=0.0002), wherein higher ω-3 levels resulted in a stronger negative association between VO2max and CRP. This was predominantly driven by alpha-linoleic acid (ALA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA), but not docosapentaenoic acid (DPAn-3) levels. We also observed negative associations between circulating levels of monocytes and VO2max for participants with lower ω-6/ω-3 or higher ω-3 EPA levels. Collectively, these data suggest that the anti-inflammatory effect of physical fitness is enhanced with higher plasma levels of ω-3 fatty acids.

Disclosure

G. Farley: None. D.W. Riggs: None. A. Bhatnagar: None. J. Hellmann: None.

Funding

National Institutes of Health (GM127495, GM127607)
1680-P: A Novel Immunomodulatory Combination That Decreases Adipose Tissue and Systemic Inflammation and Improves Metabolism in Dio Mice
Authors: SATER ZAHRAA A. , CERO CHERYL , LEA HANNAH J. , ZHU KENNETH Y. , GAVRILOVA OKSANA , CYPESS AARON M.
Published: June 2020

β3-adrenoceptors (B3AR) are major activators of lipolysis and thermogenesis in adipose tissue (AT). Obesity increases oxidative stress and AT inflammation leading to the attenuation of β3AR signaling. Alpha-lipoic acid (ALA) is a potent antioxidant. We hypothesized that the combination of ALA with CL316,243 (CL) -a selective B3AR agonist- restores the immune balance in diet-induced obesity (DIO) leading to increased B3AR function. We separated 40 DIO C57BL/6 male mice into 4 groups (n=10; individually caged) and treated them for five weeks with 1. vehicle control [IP (saline) + PO (drinking water)] 2. CL alone (0.01 mg/kg IP daily) 3. ALA alone (250 mg/kg orally in drinking water) 4. ALA+CL combination. All mice received ad-lib HFD (60% kcal fat). Systemic and epididymal white AT (epi-WAT) inflammation was decreased in ALA+CL compared to other groups, with lower serum IL-6 and IL-17 and lesser crown-like structures (CLS) on IHC for F4/80 and CD11c (M1-MΦ). Both IHC staining and mRNA expression of CD206 (M2-MΦ marker) confirm increased M2 MΦ’s in ALA+CL compared to other groups. Food intake was similar in all groups, yet mice receiving ALA+CL had a better metabolic profile: Lower body weight [+1.7 vs. -2.5g (-7%); p<0.01] and % body fat (+1.0 vs. -2.8g; (-9%), p<0.001) compared to controls preserved lean mass. Moreover, ALA+CL showed improved glucose tolerance compared to controls (intraperitoneal glucose tolerance test; AUC glycemia 31,033 ± 950 vs. 25,919 ± 620 min*ml/dl; p<0.01; AUC insulinemia 441.2 ± 55.7 vs. 279.3 ± 42.2 min*ng/ml; P<0.001). The downstream function of B3AR(lipolysis and thermogenesis) in WAT was improved in the combination group compared to all groups evidenced by markedly higher activated lipases and UCP-1 on Western blots (WB), and ucp-1 expression on mRNA analysis. Our study suggests that ALA, in combination with CL, modulates the immune response to obesity and augment catecholamine effect on lipolysis and thermogenesis in WAT.

Disclosure

Z.A. Sater: None. C. Cero: None. H.J. Lea: None. K.Y. Zhu: None. O. Gavrilova: None. A.M. Cypess: None.
1681-P: Alpha-1 Antitrypsin Suppresses Macrophage Activation Post Islet Transplantation
Authors: GOU WENYU , STRANGE CHARLIE , WANG HONGJUN
Published: June 2020

Macrophage activation contributes to islet graft loss after transplantation by secretion of proinflammatory cytokines. We showed in previous studies that treatment with alpha-1 antitrypsin (AAT) improved human islet survival after transplantation into the livers of streptozotocin-induced diabetic NOD-SCID mice. To further understand the cellular targets of AAT, we isolated macrophages from control or AAT-treated recipients at day 1 post transplantation (PT) and compared their mRNA profile using RNAseq analysis. 344 genes were changed in AAT-treated recipients compared to controls. Clusters of the inflammatory response, chemokine activity and cytokine and cytokine receptor Gene Otology categories and pathways were significantly affected by AAT-treatment. In vitro, AAT suppressed IFN-γ-induced Raw267.4 cell activation via suppression of STAT1 phosphorylation and iNOS production. This was translated in vitro when human islets were co-transplanted with IFN-γ-treated Raw cells, in the presence or absence of AAT, into diabetic NOD-SCID mice in which macrophages were depleted by liposome. At day 21, all macrophage-depleted diabetic recipients receiving islets alone achieved normoglycemia (n=6). In contrast, only 55.6% (n=9, p=0.001) receiving islets and IFN-γ-treated Raw cells achieved normoglycemia, compared to 90% receiving AAT-treated IFN-γ Raw cells (n=10, p=0.003), suggesting AAT improved islet graft survival via suppressing macrophage activation. The effect of AAT was further confirmed in a major mismatch allogeneic islet transplantation model (Balb/c, H-2b to C57BL/6 H-2d mice) in which macrophage activation contributed to primary nonfunction (PNF) of the transplanted islets. In this model, PNF occurred in 16.7% of AAT-treated recipients (n=6) but in 40% of controls (n=5) when 400 islets were transplanted.

In summary, this study further identified that AAT contributed to islet graft survival after transplantation by suppressing macrophage activation.

Disclosure

W. Gou: None. C. Strange: None. H. Wang: None.

Funding

National Institutes of Health (DK105183, DK120394, DK118529)
1685-P: Islet Encapsulation with Tannic Acid Delays Allogeneic Islet Graft Rejection
Authors: BARRA JESSIE , KOZLOVSKAYA VERONIKA , KHARLAMPIEVA EUGENIA , TSE HUBERT M.
Published: June 2020

Type 1 diabetes (T1D) is defined by the destruction of insulin-producing cells. Islet transplantation can restore glucose homeostasis and prevent serious hypoglycemic events; however, long-term graft survival is low. Oxidative stress can mediate islet transplantation rejection and suppressing oxidative stress with nanothin islet encapsulation materials comprised of alternating layers of tannic acid (TA), an immunomodulatory antioxidant, and poly(N-vinylpyrrolidone) (PVPON), a scaffold polymer, may allow for improved graft survival without systemic immunosuppression. We hypothesize that (PVPON/TA)-encapsulation of islets will prolong graft function following allotransplantation into immunocompetent recipients without utilizing systemic immunosuppression. Allogeneic transplantation of encapsulated C57BL/6 islets into diabetic non-obese diabetic (NOD) mice (n=12) significantly delayed graft failure by more than 90 days compared to controls and significantly reduced free radical-adduct formation produced by neutrophils and macrophages at the graft site. Gene expression displayed a 5- and 20-fold increase of anti-inflammatory genes Retnla and Arg1, respectively, and 3-fold reductions in Ccl5, Cxcl10, Prf1, and Grzmb mRNA accumulation in (PVPON/TA) versus control grafts. Flow cytometry analysis of encapsulated grafts contained fewer numbers of infiltrating dendritic cells and CD8 T cells and reduced frequencies of CCL5+, CXCR3+, MHC-II+ macrophages and perforin+ CD8 T cells by 3-fold compared to controls. Encapsulated grafts also reduced the frequencies of TNF+ and MHC-II+ dendritic cells by 2-fold. Additionally, encapsulation increased the frequency of arginase-1+ and CD206+ alternatively-activated macrophages 4-fold, suggesting that (PVPON/TA)-encapsulation may be a promising technique to prolong clinical islet graft function by skewing macrophage phenotypes and suppressing cytotoxic T cell effector responses in the absence of systemic immunosuppression.

Disclosure

J. Barra: None. V. Kozlovskaya: None. E. Kharlampieva: None. H.M. Tse: None.

Funding

National Institute of Diabetes and Digestive and Kidney Diseases (R01DK099550); JDRF (SRA-2016-270-S-B, JDRF 2-SRA-2019-692-S-B); National Science Foundation (NSF-DMR 1608728); National Institute of General Medical Sciences (T32GM008111)
1688-P: Peak Insulin Drip Rate Associated with Decreased Infections Post–Heart Transplant
Authors: UPADRASTA GAUTHAM , KUMAR SMITA J. , WALLIA AMISHA , MOLITCH MARK
Published: June 2020

Hyperglycemia is associated with infection and rejection in post-solid organ transplant (Tx) patients (pts), but little is known about peak insulin requirements and morbidity. We previously reported an unexpected finding in a retrospective cohort study of 207 liver Tx pts that evaluated the relationship to peak IV insulin requirements and subsequent morbidity. Pts were separated into quartiles (Q) by peak insulin drip rate [U/hr]. In that study, pts in Q4 of insulin requirements had significantly reduced infections out to 6 months post-Tx compared to Q1-3.

In the present study, we sought to replicate these findings in 188 heart Tx pts. Peak drip rate Qs are shown in the Figure below. Compared to Q1-3, Q4 pts were similar in age (53 ± 10.7 vs. 50.3 ± 9.4) and BMI (30.4 ± 6.4 vs. 29.2 ± 6.8), but more had DM (42.6% vs. 38.3%, p=0.003). Q4 pts had significantly fewer infections (19.1% vs. 53.9%, p<0.000001) up to 6 mos but similar rejections (4.3% vs. 11.3%, p=0.15). Also, we showed that avg blood glucose levels were not significantly different between Q1-3 and Q4 (p = 1.03).

These data in heart Tx pts confirm our findings in liver Tx pts that pts requiring higher insulin doses for glycemic control have decreased infections out to 6 months post Tx. We hypothesize that pts able to mount a greater counterregulatory hormone response to surgery may be healthier and able to better respond to infection. Alternatively, higher insulin doses could be protective.

Disclosure

G. Upadrasta: None. S.J. Kumar: None. A. Wallia: Research Support; Self; Eli Lilly and Company, Novo Nordisk Inc., UnitedHealth Group. M. Molitch: Advisory Panel; Self; Janssen Pharmaceuticals, Inc., Merck & Co., Inc., Pfizer Inc. Consultant; Self; AstraZeneca. Research Support; Self; Novartis Pharmaceuticals Corporation, Novo Nordisk Inc.
1690-P: In Vitro Differentiation of Pancreas-Derived Mesenchymal Stem Cells into Insulin-Producing Beta Cells
Authors: KALIVARATHAN JAGAN , SARAVANAN PRATHAB BALAJI , LEVY MARLON F. , KANAK MAZHAR A.
Published: June 2020

Differentiation of insulin-producing cells (IPCs) from stem cells has been widely studied as an alternative source for cell transplantation therapy in diabetes. Mesenchymal stem cells (MSCs) are a useful therapeutic option for islet transplants due to their immunomodulatory properties and differentiation potential. In this study, we introduce a method for in vitro differentiation of pancreatic MSCs into IPCs. Research-grade pancreas from cadaveric donors was used to isolate islets, and the COBE remnant after islet purification was used for the generation of pancreatic MSCs. The remnant tissue was cultured in RPMI medium and plastic to isolate tissue-resident MSCs. Surface marker expression analysis and differentiation assays were performed to characteristically confirm that the cells obtained were in fact MSCs. Osteogenic, adipogenic and chondrogenic differentiation of MSCs were induced by StemPro® differentiation kits. The protocol for the differentiation of IPCs from stem cells was adopted from Pagliuca et al. 2014. Similarly, we have treated the pancreatic MSCs with molecules and growth factors at different stages of development to produce IPCs. The insulin secretion from differentiated IPCs also analyzed at all stages. The culture of remnant tissue after islet isolation resulted in plastic-adherent cells of fibroblast-like morphology after 3 passages. Flow cytometry analysis showed homogeneous expression of markers (CD90, CD73, CD29, CD105) and negative expression of CD14, CD34, and CD45 as classically characterized by cultured MSCs. Interestingly, there was a significant increase in insulin levels up to 5 and 100 folds in the media at developmental stages S5 (P= 0.0686) and S6 (P <0.0001) respectively. Our results reveal that MSCs can be directly differentiated into IPCs. Human pancreas-derived MSCs may serve as an alternative source of insulin-producing beta cells that can be transplanted to type 1 diabetes patients.

Disclosure

J. Kalivarathan: None. P. Saravanan: None. M.F. Levy: None. M.A. Kanak: None.