bluuebunny/crossref_metadata_2025 huggingface dataset:
CRISPR Mediated Deletion of a Proxy 19.2kb Distal to the T2D GWAS-Implicated SLC30A8 R325W Variant Impacts RAD21 and UTP23 Gene Expression in HepG2 Cells
Authors: HODGE KENYAITA M. , LU SUMEI , LEONARD MICHELLE , PIPPIN JAMES A. , CHESI ALESSANDRA , WELLS ANDREW D. , JOHNSON MATTHEW , GRANT STRUAN F.
Published: June 2018

Genome wide association studies (GWAS) have revealed multiple loci for type 2 diabetes (T2D). However, given that GWAS generally only reports genomic signals associated with a given trait, there is need for follow-up characterization. Despite key reports of missense variants within SLC30A8 conferring protection of T2D risk, there is still need to better understand the relationship between the GWAS signal and mechanism at this locus. The application of ’Assay for Transposase Accessible Chromatin combined with sequencing’ (ATAC-seq) to Endo-BH1, SGBS and HepG2 cell lines, representing models for pancreatic beta-cells, adipose and liver respectively, allowed us to filter for putatively informative proxy SNPs (r2>0.8) coinciding with open chromatin at this locus. Following sequencing on the Illumina Hi-Seq platform, the sentinel SNP itself coincided with open chromatin, namely rs13266634 (a missense R325W variant), in both Endo-BH1 and SGBS; however, in HepG2 this region was closed while proxy rs9650069 was open, situated 3’ to SLC30A8 and 19.2kb from rs13266634. We elected to generate CRISPR/Cas9 mediated deletions immediately around rs9650069 in a mixed cell setting. Following confirmation of deletion by sequencing, we assessed changes in expression for all genes in the corresponding topological associating domain (TAD), namely SLC30A8, AARD, EIF3H, RAD21, TRPS1 and UTP23. Two genes revealed a significant change in expression when normalized to beta-actin, namely RAD21 and UTP23, yielding 5.58 fold and 4.57 fold decreases, respectively. Given that according to GTEx the expression of SLC30A8 is largely contained to the pancreas, this gene was not expressed in this cell setting and thus the impact of this deletion on this gene could not be assessed. This effort implicates an enhancer element for these genes in a liver cell model as being a part of the machinery genetically controlling this locus.

Disclosure

K.M. Hodge: None. S. Lu: None. M. Leonard: None. J.A. Pippin: None. A. Chesi: None. A.D. Wells: None. M. Johnson: None. S.F. Grant: None.
Heme Deficiency Causes Impaired Glycogen Synthesis in Skeletal Muscle Leading to Insulin Resistance
Authors: NAKAJIMA OSAMU , SAITOH SHINICHI , KIMURA TOMOHIRO , OSAKI TSUKASA , VINCENT KELLY P. , TAKAHASHI KIWAMU , TANAKA TOHRU , NAKAJIMA MOTOWO
Published: June 2018

In vertebrates, the initial step in heme biosynthesis is the production of 5-aminolevulinic acid (ALA) by ALA synthase (ALAS). The ALAS1 gene encodes a ubiquitously expressed isozyme. Mice heterozygous null for ALAS1 (A1+/-s) experience mitochondrial dysfunction in skeletal muscle, impaired glucose tolerance (IGT) and insulin resistance (IR) past 20-weeks of age (aged A1+/-s) 1). IGT/IR in aged A1+/-s was remedied by oral administration of ALA for 1-week1). By contrast, mitochondrial dysfunction required 6-weeks of ALA administration before improvements could be observed, indicating the phenotype of IGT/ IR is not due to mitochondrial dysfunction1). We found no remarkable change in expressions and phosphorylation of proteins related to insulin signalling such as Akt and GSK3β in skeletal muscle of aged A1+/-s1). Rather, abnormal ultrastructure of glycogen granules and increased glycogen contents were observed in skeletal muscle of aged A1+/-s unlike of less than 15-weeks-old A1+/-s, and those abnormalities of glycogen were reversed after ALA-treatment for 1-week as well as IGT/IR. The quantification of glycogen contents showed that insulin-induced glycogen synthesis was impaired in skeletal muscle of aged A1+/-s, and the reduced de novo glycogen synthesis was recovered in ALA-administrated aged A1+/-s. Glycogen synthase (GS) activities were constitutively activated even at the low concentration of glucose 6-phosphate (G6P) and not augmented at the high concentration of G6P in extracts from skeletal muscle of aged A1+/-s, suggesting that GS fails to respond to allosteric activation by G6P. While, GS activities were normally regulated in those of ALA-administered aged A1+/-s. Taken together, our data suggest that impaired de novo glycogen synthesis in skeletal muscle is relevant to IGT/IR in aged A1+/-s due to constitutively activated GS without allosteric activation by G6P. Ref. 1) Saitoh et al. PLOS ONE in press.

Disclosure

O. Nakajima: None. S. Saitoh: Research Support; Spouse/Partner; Japan Society for the Promotion of Science, SBI Pharmaceuticals Co.,Ltd.. T. Kimura: None. T. Osaki: None. K.P. Vincent: Research Support; Self; Kora Healthcare. K. Takahashi: None. T. Tanaka: None. M. Nakajima: None.
SNP x SNP Interactions Elucidate TCF7L2’s Physiology Conveying Incretin Action
Authors: JAGHUTRIZ BENJAMIN , HENI MARTIN , LUTZ STEFAN Z. , STAIGER HARALD , PETER ANDREAS , HAERING HANS-ULRICH , FRITSCHE ANDREAS , WAGNER ROBERT
Published: June 2018

Introduction: Genetic polymorphisms in TCF7L2 are the strongest common risk variants for type 2 diabetes. We and others had showed that genetic variation in TCF7L2 affects incretin-stimulated insulin secretion. A recent genome-wide association study discovered variants associated with incretin levels. We hypothesized that these SNPs interact with the well-known TCF7L2 variant rs7903146 on insulin secretion due to their incretin altering effect.

Methods: Insulin secretion was measured with OGTT-based indices that were calculated from insulin, C-peptide and glucose levels in the cross-sectional TUEF-cohort (n=2929). We also measured insulin secretion in a modified hyperglycemic clamp at 10 mmol/l, using additional GLP-1 infusion at the end of the clamp (n=76). Besides rs7903146 in TCF7L2, we genotyped rs17681684 in GLP2R, rs1800437 in GIPR, rs17683011 in SLC5A1, as well as 3 additional variants associated with GIP levels.

Results: Four of the 6 incretin-associated SNPs exhibited at least nominally significant SNP x SNP interactions with rs7903146 in TCF7L2 on insulin secretion measured by the corrected insulin response (CIR). In the hyperglycemic clamp study, rs7903146 in TCF7L2 interacted with rs1800437 (GIPR) on both AUC insulin and C-peptide, and rs17681684 (GLP2R) on AUC C-peptide during the GLP-1 stimulation phase (p<0.05).

Conclusion: These findings corroborate the role of the TCF7L2 variant in mediating incretin action to increase diabetes risk. They highlight the importance of SNP x SNP interactions in the assessment of the genetic architecture of type 2 diabetes.

Disclosure

B. Jaghutriz: None. M. Heni: Research Support; Self; Boehringer Ingelheim GmbH. Speaker's Bureau; Self; Boehringer Ingelheim GmbH, Merck Sharp & Dohme Corp., Novo Nordisk Inc.. S.Z. Lutz: None. H. Staiger: None. A. Peter: None. H. Haering: None. A. Fritsche: Advisory Panel; Self; Sanofi-Aventis Deutschland GmbH, Novo Nordisk A/S, Eli Lilly and Company, Boehringer Ingelheim GmbH. R. Wagner: None.
Effects of Aerobic and Resistance Training on Circulating Micro-RNA Expression Profile in Subjects with Type 2 Diabetes
Authors: OLIOSO DEBORA , DAURIZ MARCO , BACCHI ELISABETTA , NEGRI CARLO , BONORA ENZO , MOGHETTI PAOLO
Published: June 2018

Structured exercise programs are of great benefit in order to obtain a proper glycemic control in subjects with type diabetes (T2D). However, whether the metabolic effects of aerobic (AER) and resistance (RES) exercise exert specific changes in the expression profile of circulating miRNAs (c-miRNAs) is still largely unknown. We studied 24 individuals with T2D from the RAED2 Trial (NCT01182948), randomly assigned to AER or RES training protocols (NAER=12; NRES=12). Firstly, the baseline and post-training levels of 179 c-miRNAs were measured by RT-PCR in 6 individuals (NAER=3; NRES=3). Nineteen c-miRNAs exhibited at least 20% fold-change variation from baseline and were thereafter measured in the whole group. Compared to baseline, the expression levels of miR-423-3p, miR-451a and miR-766-3p resulted significantly upregulated after exercise, irrespective of exercise type (type I error rate threshold: 0.0026; 0.05/19 miRNAs). Bioinformatic analysis by miRSystem and Diana Tools revealed that these c-miRNAs targeted genes involved in pathways relevant to fatty acids biosynthesis and metabolic regulation, including LKB1, PI3K, mTOR and IRS signaling pathways. Interestingly, miR-451a and miR-423-3p changes were positively correlated with fat loss after training (rho=0.45 and 0.43, respectively; p<0.05). Both miRNAs, alone or in combination, resulted as independent predictors of fat loss, when entered in generalized linear models including exercise type as covariate. However, only miR-451a eventually survived as predictor of fat loss after further correction for age, sex, BMI and hemoglobin A1c.

In conclusion, physical exercise in individuals with T2D is associated with specific changes of c-miRNAs profile, predominantly clustered along pathways with regulatory significance for fatty acid metabolism. Further investigations are warranted to confirm our findings and to unravel their mechanistic significance.

Disclosure

D. Olioso: None. M. Dauriz: None. E. Bacchi: None. C. Negri: None. E. Bonora: None. P. Moghetti: None.
A Comparison of the Impact of the 2017 ACC/AHA Hypertension Guidelines on Primary Care Populations With and Without Diabetes
Authors: SPERL-HILLEN JOANN M. , ANDERSON JEFFREY P. , DESAI JAY R. , MARGOLIS KAREN L. , CRAIN A. LAUREN , O'CONNOR PATRICK J.
Published: June 2018

Background: Our objective was to assess the impact on primary care of the 2017 ACC/AHA lowering of the threshold for diagnosing HTN to a BP ≥ 130/80 mm Hg, and pharmacologic treatment intensification recommendations for patients with high CV risk and/or DM who have BP levels 130-139/80-89 mm Hg.

Discussion: 62% of patients with DM and 57% without DM had a BP ≥ 130/80 mm Hg, and over half of these will require reclassification of HTN due to BP 130-139/80-89 mm Hg.Of patients with Stage 1 HTN, 76.8% of patients with DM and 39.4% without DM are already treated (but above goal). 25% of all DM patients (7755/30,608) and 13% of all non-DM patients (22963/176,555) are currently treated with Stage 1 HTN and will require an increase in BP medication to achieve BP < 130/80 mm Hg.7.7% of all DM patients (2344/30,608) and 2.3% of all non- DM patients with CV risk ≥ 10% (3960/176,555) are currently untreated with Stage 1 HTN and medication initiation will be recommended. If pharmacologic treatment initiation recommendations were limited to those with CV risk ≥ 10% for DM patients, BP medication initiation recommendations would decrease from 7.7% to 2.9% (896/30,608) of the DM population.

Conclusion: The 2017 ACC/AHA guideline will result in a significantly increased need for primary care to address BP medication intensification, with a much greater proportional impact on those with DM compared to those without.

Disclosure

J.M. Sperl-Hillen: None. J.P. Anderson: None. J.R. Desai: None. K.L. Margolis: None. A. Crain: None. P.J. O'Connor: None.
No Evidence of a Causal Association between Diabetes-Related Phenotypes and Atrial Fibrillation
Authors: HARATI HADI , ZANETTI DANIELA , INGELSSON ERIK , KNOWLES JOSH
Published: June 2018

Background: Several epidemiological studies have shown an association between increased fasting and 2-hour plasma glucose (FPG and 2hPG), hemoglobin A1C (A1C), and fasting insulin (FI) and risk of atrial fibrillation (AF). We aimed to assess whether this relation is causal using genetic data from large populations of individuals of European descent.

Methods: Two-sample Mendelian randomization (MR) was used to obtain estimates of influence of the risk factors (FPG, 2hPG, A1C and FI) on risk of the outcome (AF). Instrumental variables (IVs) were constructed using the previously reported single nucleotide polymorphisms (SNPs) associated with each risk factor at p-value<e-8 from the Meta-Analyses of Glucose and Insulin-related traits Consortium (MAGIC) with up to 133,000 nondiabetic participants. Selected SNPs were checked for pleiotropy using the UK Biobank dataset and those associated with the confounders at p-value<e-8 were excluded. AF consortium (AFGen) summary statistics with 22,346 AF cases and 132,086 controls was used for the outcome data analysis.

Results: Two-step MR with inverse variance weighted methods did not show any causal association between diabetes related phneotypes and AF [FPG (30 SNPs, p=0.7), 2hPG (7 SNPs, p=0.3), A1C (11 SNPs, p=0.3), or FI (13 SNPs, p=0.9)]. None of the IVs showed horizontal pleiotropy indicating that the used genetic variants affected the outcome only via their effect on the diabetes related phenotypes (p-values of 0.56, 0.09, 0.099, and 0.31 respectively for FPG, 2hPG, A1C, and FI). Calculated power based on the original set of SNPs in the MAGIC and estimated odds ratio of 1.2 were 99, 94, 99, and 84% respectively for FBG, 2hPG, A1C, and FI.

Conclusion: This MR analysis does not support a causal role between genetically programmed diabetes related traits (FPG, 2hPG, A1C, or FI) and AF. These data suggest that drug treatment to reduce dysglycemia in nondiabetics may not be an effective strategy for AF prevention.

Disclosure

H. Harati: None. D. Zanetti: None. E. Ingelsson: None. J. Knowles: None.
A Pilot Study of Preproinsulin Peptides Reactivity in Chinese Type 1 Diabetic Patients
Authors: XIAN YINGXIN , XU HAIXIA , LV JING , GAO YIFANG , REN WENQIAN , HUANG QIANWEN , JIANG ZIYU , YAN JINHUA , YAO BIN , WENG JIANPING
Published: June 2018

Type 1 diabetes (T1D) is an autoimmune disease in which auto-reactive T cells infiltrate the pancreatic islets and destroy insulin-producing β cells. Preproinsulin (PPI) is considered as an important autoantigen for developing T1D in Caucasian population, particularly in those bearing T1D associated susceptible alleles DRB1*04:01, DQA1*03:01 and DQB1*03:02. However, whether PPI could trigger similar responses in Chinese T1D patients remains elusive. Peripheral blood mononuclear cells from 19 newly diagnosed T1D (Mean Age =16.7yr) and 32 long term T1D patients (Mean Age =21.3yr) of Chinese Han nationality were isolated and stimulated by a pool of 13 different PPI peptides, which were synthesized according to epitope mapping of the full length PPI. PPI reactive T cells were measured by IFN-γELISPOT assay. Briefly, the mean values in wells with peptides were compared with those in background wells to derive a stimulation index (SI). A specific IFN-γresponse is defined as SI≥3. All patients showed a significant IFN-γresponse to OKT 3 stimulation, and 96% of patients showed positive responses to Pentaxim vaccine. However, we did not detect specific IFN-γresponse to PPI peptides with a range of concentrations (i.e., 1ug/ml to 100ug/ml). To confirm our results, 2 peptides (C19-A3, B9-23) with dominant epitopes known to be presented by DR4 and DQ8 were also tested. In agreement with the PPI peptide pool study, these 2 peptides did not induce specific IFN-γproducing T cells activity. This includes six patients with DQA1*03:01 and DQB1*03:02 alleles. This is the first report describing IFN-γresponse of T cells to overlapping human PPI peptides in Chinese T1D patient. It is worth knowing that, unlike the Caucasian T1D population, around 30% of Chinese T1D population uniquely consist the DRB1*09:01 allele (20% in our study population). Thus, the lack of specific response in our patient cohort suggests that PPI might not be the principal disease causing antigen in Chinese T1D due to the population heterogeneity.

Disclosure

Y. Xian: None. H. Xu: None. J. Lv: None. Y. Gao: None. W. Ren: None. Q. Huang: None. Z. Jiang: None. J. Yan: None. B. Yao: None. J. Weng: None.
Mucosal Gamma/Delta T Cells Increased by i.n. Administration of Gliadin to Four-Week-Old NOD Mice Prevent Diabetes in the NOD-SCID Model of Adoptive Cotransfer of Diabetes
Authors: FUNDA DAVID , GOLIAS JAROSLAV , HAUPT-JORGENSEN MARTIN , BUSCHARD KARSTEN
Published: June 2018

Beta-cell autoantigens, e.g., insulin, proinsulin, or GAD65, have been investigated both in animal models and human trials for induction of beta-cell specific tolerance to prevent the development of type 1 diabetes (T1D). On the other hand, environmental factors that significantly contribute to the recent outbreak of T1D were less studied, probably due to their complexity. The dietary wheat protein fraction has been associated with high penetrance of the disease, whereas gluten-free diets prevented T1D in animal models. We have previously reported that i.n. administration of gliadin prevented diabetes in NOD mice. Herewith we investigated mucosal gamma/delta T cells that were induced by i.n. administration of gliadin for their regulatory capacity to prevent diabetes in the NOD-SCID model of diabetes co-transfer. I.n. administration of gliadin to 4-week-old NOD mice increased proportion of gamma/delta T cells in pancreatic and mesenteric lymph nodes. Adoptive co-transfer of 2x106 gamma/delta T cells with 1x107 diabetogenic splenocytes led to statistically significant (p<0.01) diabetes prevention. The gamma/delta T cells were characterized for their memory-naïve and mucosal homing properties, or NK-like features by assessing expression of CD8alpha, CD45RB, CD62L, CCR7, CD103 and NKG2D by flowcytometry.

In conclusion, similar to i.n. administration of insulin, i.n. vaccination with gliadin, an environmental antigen with possible ethiological influence in T1D, led to increased proportion of mucosal gamma/delta T cells. These gamma/delta T cells possess regulatory capacity to prevent diabetes transfer in the NOD-SCID model and may represent a novel and safer strategy for prevention or an early intervention in T1D.

Disclosure

D. Funda: None. J. Golias: None. M. Haupt-Jorgensen: None. K. Buschard: None.
Are Liver Cystic Lesions after Islet Transplantation Caused by Streptozotocine?
Authors: KOSINOVÁ LUCIE , PATIKOVA ALZBETA , STICOVA EVA , VOJTÍŠKOVÁ ALŽBěTA , BARTONOVA LENKA , CAHOVA MONIKA , KRIZ JAN
Published: June 2018

Introduction: Pancreatic islets (PI) transplanted (Tx) into the portal vein cause a permanent exposure of surrounding liver tissue to insulin in high concentration. There were published several papers pronouncing the hypothesis of a direct triggering effect of Tx PI on a development of focal morphological changes in liver tissue (tumors, cysts). At the same time, streptozotocine (STZ) was supposed to play a minor but not negligible role in this phenomenon.

Methods: Syngeneic pancreatic islets were transplanted into the healthy or diabetic (50mg/kg STZ) Brown Norway rats. Group A (n=5)-healthy, Tx of 450 PI into the portal vein; Group B (n=17)-STZ diabetes, Tx of 450 PI into the portal vein; Group C (n=8)-STZ diabetes, Tx of 100 PI under the left kidney capsule; Group D (n=7)-STZ diabetes, human insulin pellet s.c. (changed each 6th week); All recipients were monitored for 10 months including MRI of liver. At the end of study each liver was examined by histology. The ultrastructure of liver was examined by electron microscopy (TEM) 3 hours after injection of STZ.

Results: Tx of PI in suboptimal number normalized fasting blood glucose levels but did not normalize glucose assimilation during IVGTT in all diabetic animals. While liver of Group A recipients remained intact, in animals of Groups B and C multiple voluminous cystic complexes with cholangiocyte cubic epithelium lining were detected after 10 months irrespective of Tx site. In animals of Group D, blood glucose levels were nearly normalized six months after STZ injection and there was no need to replace pellets later on. There were simple, individual cystic lesions within liver in this group after 10 months. There were not any typical lesions in TEM examined samples.

Conclusions: The injection of STZ and subsequent Tx of PI can cause cholagiogenic cystic lesions development in rats. The therapy by human insulin did not stimulate the development of cystic lesions by the equal efficiency. STZ itself cannot cause the cystic transformation of BN rat liver.

Disclosure

L. Kosinová: None. A. Patikova: None. E. Sticova: None. A. Vojtíšková: None. L. Bartonova: None. M. Cahova: None. J. Kriz: None.
Gender and Age Variations in Obesity in the Jackson Heart Study
Authors: CORREA ADOLFO , GAO YAN , BROWN LAVONNE D. , BELL RONNY A. , BERTONI ALAIN
Published: June 2018

In 2013-2014 in the U.S., the prevalence of obesity (body mass index (BMI)≥30 kg/m2) among African Americans was 38.2% in men and 57.2% in women, decreasing after age 60 in men but not in women. We used data from the Jackson Heart Study (JHS) to examine gender- and age-variations in prevalence of obesity as defined by BMI, waist circumference (WC), and waist-to-height ratio (WHtR). Based on data from JHS Visit 3 (2009-2013), we conducted a cross-sectional analysis of prevalence of obesity defined by BMI (≥30), WC (>88 cm among women and >102 cm among men), and WHtR (>0.5) by age and gender. We used logistic regression to evaluate associations of obesity defined by BMI (ref: BMI<25), WC (ref: ≤88 cm for women and ≤102 cm for men) and WHtR (ref: ≤ 0.5) with gender and age, adjusted for physical activity. JHS Visit 3 participants (n=3680) were 64% female and had a mean age of 62.2 years. Prevalence of obesity defined by BMI for age groups 20-49, 50-59, and ≥60 years was 67%, 67%, and 59%, respectively (p=0.005) among women; and 58%, 48%, and 40% respectively (p<0.001) among men. For the same age groups, the prevalence of obesity defined by WC was 82%, 83%, and 83%, respectively (p=0.732) for women, and 48%, 51% and 47%, respectively (p=0.540) for men; and by WHtR was 91%, 94%, and 94%, respectively (p=0.127) for women, and 87%, 87%, and 89%, respectively (p<0.001) for men. Age- and physical activity-adjusted odds ratio (aORs) for obesity among women compared to men were 2.2 (95% CI: 1.8-2.7) when based on BMI, 5.2 (95% CI: 4.5-6.1) when based on WC, and 2.0 (95% CI: 1.5-2.5) when based on WHtR. For women, physical activity-aOR for obesity per 1-year increment in age was 0.96 (95% CI: 0.95-0.97) when based on BMI but did not differ from the null when based on WC or WHtR. For men, similar physical activity-aORs for obesity per 1-year increment were observed. For both women and men, prevalence of obesity defined by BMI decreased with age but not when defined by WC or WHtR. Age-related decreases in obesity defined by BMI may not reflect decreases in obesity defined by WHtR.

Disclosure

A. Correa: None. Y. Gao: None. L.D. Brown: None. R.A. Bell: None. A. Bertoni: Other Relationship; Self; Merck & Co., Inc..
Constitutively Active Grp1 Promotes Basal Glucose Transport into White Adipose and Enhances Insulin Sensitivity in High-Fat Fed Mice
Authors: COPPS KYLE D. , LI JIAN
Published: June 2018

Insulin-stimulated phosphorylation of Grp1 (general receptor for phosphoinositides; a.k.a Cyth3, cytohesin3) in cultured adipocytes is known to promote recycling of insulin-regulated glucose transporter (Glut4)-containing vesicles from the endosome to plasma membrane, and to enhance glucose uptake thereafter. We found that Cre-dependent expression of a constitutively active form of Grp1 (caGrp1) specifically increased basal glucose uptake into WAT of young chow-fed mice, without altering Akt phosphorylation or insulin-stimulated uptake. Although early growth and glucose homeostasis in chow-fed caGrp1 mice were normal, caGrp1 mice fed a high fat diet (HFD) became markedly less adipose, and showed improved glucose tolerance and insulin sensitivity vs. Cre-negative controls. Fasting insulinemia in HFD-fed caGrp1 mice was lower, whereas circulating adiponectin was higher, and FGF-21 and leptin were unchanged. Hepatic lipid disposition in HFD-fed caGrp1 mice was comparable to that in controls, though circulating and liver free fatty acids were slightly lower. However, epigonadal WAT from caGrp1 mice showed markedly reduced staining for inflammatory marker CD68, and adipocyte size was also significantly greater. Collectively, these features distinguish caGrp1 mice from those with adipose-specific over-expression of Glut4 described by others, but remain compatible with an adipose-specific basis of improved systemic insulin sensitivity. Given recently improved understanding of the structural/functional changes induced in Grp1 via Akt phosphorylation, drug-based activation of Grp1 in WAT might prove an attractive route by which to favorably alter systemic insulin sensitivity and glycemia.

Disclosure

K.D. Copps: None. J. Li: None.
Regulation of Insulin Sensitivity by Phosphorus
Authors: LIN YI , BERGER LINDSEY , SUN ZHONGJIE
Published: June 2018

Dietary phosphorus excess as a result of the ever growing consumption of highly processed foods has been associated with developments of ageing related diseases such as diabetes and obesity in the general human population. Insulin resistance is the main feature of aged human population especially in patients with type 2 diabetes and some people with obesity. Thus, the study of a low phosphorus diet on glucose homeostasis such as insulin resistance and glucose tolerance is of great interest. Here, we investigated glucose homeostasis in male and female 129Sv mice fed with low phosphorus diet (0.2% of Pi) vs. control diet (0.4% of Pi). Interestingly, the fasting basal glucose level dropped significantly in male mice after being fed with low Pi diet for 4 weeks. In addition, low Pi diet significantly enhanced insulin sensitivity in both male and female mice. Furthermore, low Pi diet lowered serum Pi levels in mice of both genders without interrupting the growing pattern of body weights during the 10-week feeding period. Examination of proteins with Western Blot revealed that low Pi diet significantly enhanced insulin receptor β (IRβ) levels in skeletal muscles. In vitro experiments indicated that low Pi enhanced and high Pi inhibited insulin signals such as tyrosine phosphorylation of IRβ (Tyr1150/1151) and serine phosphorylation of Akt (Ser473) in primary culture of human skeletal muscle cells (HSkMCs). In addition, low Pi increased and high Pi decreased insulin-induced glucose uptake in HSkMCs. Therefore, these data indicate that low Pi diet regulates glucose homeostasis, partly via enhancing insulin sensitivity through upregulating insulin signals and insulin-induced glucose uptake in skeletal muscles.

Disclosure

Y. Lin: None. L. Berger: None. Z. Sun: None.
Actions of Apolipoprotein A-IV on Insulin-Independent Glucose Control and Activation of Akt in Mouse Liver
Authors: HE JING , ZHAO JING , YANG ZIYU , ZHANG JIANBO , WEI SHUGUANG , LI SHENGBIN , LI XIAOMING
Published: June 2018

Insulin resistance is a risk factor for type 2 diabetes, fatty liver and metabolic syndrome. We reported previously that apolipoprotein A-IV (ApoA4) increased insulin secretion, insulin sensitivity and improved glucose uptake in adipocytes by PI3K-Akt pathways. Whether insulin sensitivity is improved by ApoA4 in mouse liver remains unclear. Here we used mice as well as hepatocytes to investigate the action of ApoA4 on glucose control and hepatic Akt activation. Liver tissues were from lean mice 2 h after a single ip injection of recombinant mouse ApoA4 (n = 5 per group) and tissue lysates were separated by Western blotting with anti-pAkt antibody. Primary mouse hepatocytes were cultured for glucose-uptake experiment and pAkt analysis after ApoA4 stimulation. Approach to block insulin secretion transiently in insulin-resistant DIO mice (6wk-HFD) and lean mice by propranolol and epinephrine was used by co-administration with glucose after a single ip injection of ApoA4 prior to being sacrificed for the liver. Treatment of the mice with ApoA4 for 2 h increased Akt phosphorylation from liver in dose-dependent in the basal state. In time and dose-dependent manner, direct action of ApoA4 on Akt activation in primary mouse hepatocytes too indicates this effect was insulin independent. ApoA4 treatment also increased [3H]-2-deoxyglucose uptake by primary mouse hepatocytes. The contributions of ApoA4 on insulin-independent glucose disposal was verified with insulin blocking. ApoA4 to an equal extent of direct insulin-independent and insulin-dependent, enhanced blood glucose clearance in both insulin-resistant DIO mice and lean mice. With the glucose challenge, ApoA4 treatment resulted in an increase in Akt phosphorylation in liver, heart and brown adipose tissue in insulin-dependent in lean mice, but which was in insulin-independent only in liver in DIO mice. Data imply ApoA4 as a novel antidiabetic drug to treatments of diabetic diseases.

Disclosure

J. He: None. J. Zhao: None. Z. Yang: None. J. Zhang: None. S. Wei: None. S. Li: None. X. Li: None.
Pharmacologic Uncoupling of Skeletal Muscle Mitochondria Promotes Glucose Metabolism
Authors: HULL MICHAELA E. , AXELROD CHRISTOPHER L. , FITZGERALD KELLY M. , SACKS JESSICA , KIRWAN JOHN P.
Published: June 2018

Mitochondrial uncoupling was one of the earliest pharmacologic approaches to the treatment of obesity-related diseases. However, low mitochondrial specificity and negative off-target effects limited the viability of such agents. BAM15 is a small molecule recently identified for its potent ability to uncouple mitochondria. Thus, the purpose of this investigation was to explore the physiological effects of BAM15 on skeletal muscle mitochondrial function and glucose metabolism. C2C12 myotubes were incubated with either vehicle or BAM15 at varying concentrations for 16 hours. Cell viability was assessed by detection of dehydrogenase activity. Cytotoxicity was measured by a Caspase 3/7 activity assay. Glucose uptake was measured using [3H]-2-deoxy-D-glucose in the presence and absence of insulin. Oxygen consumption rates were measured using an XF24 extracellular flux analyzer. Cells were harvested for the assessment of plasma membrane GLUT4 and protein signaling via Western blot. Cells treated with BAM15 were viable up to 100 μM, and lacked toxicity up to 50 μM, compared to vehicle. BAM15 significantly increased glucose uptake (P<0.05) at concentrations as low as 6.25 μM. Concentrations of 25 μM and above exhibited a 2-4 fold greater glucose uptake than insulin (P<0.05), which saturated at 50 μM. BAM15 significantly increased basal oxygen consumption (P<0.05), while markedly reducing coupling efficiency (P<0.05). BAM15 upregulated primary energy homeostasis pathways via activation of AKT (t3and s473), AS160 (t642), and AMPK (t172). Additionally, BAM15 increased plasma membrane GLUT4 translocation (P<0.05). BAM15 is a pharmacologically active compound with low toxicity and mitochondrial specificity capable of inducing glucose metabolism in skeletal muscle. These data provide compelling evidence for future investigation of BAM15 as a potential treatment for diabetes and other obesity-related metabolic diseases.

Disclosure

M.E. Hull: None. C.L. Axelrod: None. K.M. Fitzgerald: None. J. Sacks: None. J.P. Kirwan: None.
Isoform-Selective Targeting of Facilitative Glucose Transporters with Small Molecule Inhibitors
Authors: HEITMEIER MONIQUE , HRESKO RICHARD C. , SHANMUGAM MALA , HRUZ PAUL W.
Published: June 2018

There are currently 14 known mammalian facilitative glucose transporters (GLUTs) that serve a variety of critical roles in maintaining glucose homeostasis. The ability to potently target glucose transport in an isoform-selective manner is of paramount importance to investigate the normal function of these transporter isoforms and their individual contributions to disease pathogenesis. A number of GLUT isoform-selective small molecule inhibitors have been identified. To investigate the structural basis of GLUT inhibition and facilitate further refinement of the efficacy and selectivity of these antagonists, we performed kinetic analysis of the effects of WBZ-117, C-20, BAY-876 and several HIV protease inhibitors, on 3H-2-deoxyglucose uptake into cell lines selectively over-expressing GLUT1, GLUT4 or a T30I H160N GLUT1 mutant transporter. Several important findings were made: 1) based on Ki(app) measurements, indinavir, lopinavir, WZB-117 and C-20 selectively inhibit GLUT4 13-55 fold vs. GLUT1. Although structurally divergent, the potency of these 4 compounds against GLUT1 can be markedly enhanced to levels approximating those for GLUT4 by substituting just two GLUT1 amino acids located in the glucose permeation pathway to those found in GLUT4 (T30I and H160N); 2) nelfinavir is a weak GLUT4 inhibitor but acts as a GLUT1 activator, increasing transport activity 1.4-fold; 3) saquinavir selectively inhibits GLUT4 and the T30I H160N GLUT1 mutant, and exhibits complex kinetic patterns in the mutant cell line consistent with a two site model for partial inhibition; 4) kinetic analysis revealed that selective GLUT1 inhibitor, BAY-876, is a noncompetitive inhibitor of this transporter. Taken together, these data provide key structural insights into the ability of small molecules to alter GLUT function that will aid in the development of novel isoform-selective drugs for glucose-dependent diseases.

Disclosure

M. Heitmeier: None. R.C. Hresko: None. M. Shanmugam: None. P.W. Hruz: None.
Modeling the Spectrum of Human Insulin Resistance Using Induced Pluripotent Stem Cells
Authors: LEBASTCHI JASMIN , BATISTA THIAGO M. , CARCAMO-ORIVE IVAN , KROOK ANNA , ZIERATH JULEEN R. , KNOWLES JOSH , RONALD KAHN C.
Published: June 2018

Induced pluripotent stem cells (iPSCs) represent a unique model to study the genetic components of insulin resistant states in vitro and can be studied in both the undifferentiated and differentiated state. In prior studies we have shown that iPSCs from patients with insulin receptor mutations exhibit altered insulin signaling with reduced insulin-stimulated phosphorylation of IR, IRS, and AKT in iPS-derived myotubes compared to healthy subjects and have reduced insulin stimulation of proliferation and gene expression. We now use iPSCs to characterize the insulin response of type 2 diabetics (T2D) and nondiabetic individuals before and after differentiation to skeletal muscle. The iPSCs from a subgroup of the nondiabetic individuals were further divided into those in the upper and lower quartiles of insulin resistance as determined using steady-state plasma glucose (SSPG) methodology. We find that iPSCs from insulin sensitive controls, insulin resistant (IR) nondiabetics and from patient with type 2 diabetes exhibited similar levels of pluripotency markers and showed similar changes in markers of muscle differentiation through the satellite cell-like and myoblast/myotube stage. This was true for iPSC derived from blood cells and from muscle biopsies. Insulin-induced activation of early signaling steps including phosphorylation of IR, IRS, AKT, ERK and GSK3 showed dose-responsive phosphorylation in the iPSC, as well as myotube stage with significant 10 nM and 100 nM insulin. Importantly, iPSCs differentiated into satellite-like cells displayed insulin resistance at the level of AKT phosphorylation in both the T2D and IR patients (p=0.0134 and p=0.0352). There was also decreased GSK3 phosphorylation in cells from T2D patients (p=0.0325). Thus, iPSC-derived muscle satellite-like cells from T2D and nondiabetic IR individuals retain defects in AKT and GSK3 phosphorylation indicating a level of a genetic or persistent epigenetic signature of insulin resistance in vitro.

Disclosure

J. Lebastchi: None. T.M. Batista: None. I. Carcamo-Orive: None. A. Krook: None. J.R. Zierath: None. J. Knowles: None. C. Kahn: Advisory Panel; Self; CohBar, ERX Therapeutics, AntriaBio, Inc.. Board Member; Self; Kaleio Biosciences.
DJB Surgery Improved the T2DM Rats Glucose Homeostasis, Elevated the Glucose Utilization, and the GLUT3 Expression in Brain
Authors: PAN RUIYAN , LI NA , ZHAO TINGKUN , WANG HUAIJIE , JIANG BIN , YAN QINGTAO , GAO ZHIQIN , QU MEI-HUA
Published: June 2018

Duodenal-jejunal bypass surgery (DJB) is a experimental surgical procedure to study the mechanism of gastric surgery in T2DM treatment.

Methods: T2DM rats induced by high glucose high fat food and low dose streptozotocin (STZ) injection were randomly divided into 2 groups: T2DM group and DJB surgery group (T2DM-DJB).Wistar rats were used as normal control. The fasting blood glucose and HbA1C were measured. Glucose utilizationin the brain was detected by small animal positron emission tomography (PET) using [18F]-fluorodeoxyglucose ([18F]-FDG).GLUT1, GLUT3 expression in the brain were measured by Q-RT-PCR.

Results:DJB surgery significantly decreased the fasting blood glucose and Hb1Ac of the T2DM rats. [18F]-FDG uptake (standardized uptake values (SUV)mean)in the brain was elevated siginificantly 4 weeks after DJB (Wistar vs. T2DM vs. T2DM-DJB: SUVmean value 1.30±0.27 vs. 0.59±0.10 vs. 1.55±0.31, P<0.001). Q-RT-PCR showed that GLUT3 expression in the brain significantly increased 4 weeks after DJB while T2DM rats decreased. This study indicates that the improvement of glucose utilization in the brain plays an pivotal role in DJB treatment of T2DM.

Disclosure

R. Pan: None. N. Li: None. T. Zhao: None. H. Wang: None. B. Jiang: None. Q. Yan: None. Z. Gao: None. M. Qu: None.
The Risk of Breast Cancer in Women with Diabetes
Authors: BOTA MARIA , AUTIER PHILIPPE , BOYLE PETER
Published: June 2018

Some observational studies have suggested an increased risk of breast cancer (BC) among diabetic patients. A meta-analysis was performed to assess the risk of BC in diabetic patients compared to nondiabetic patients. Studies were selected if they had a prospective design. Studies that compared BC incidence in women with diabetes to the incidence in the general population were excluded. Summary relative risks (SRR) were computed using a random-effect model. Eighteen studies were included in the meta-analysis, including 28,230,143 person-years of follow-up and 320,111 BC cases. A significantly increased risk of BC among diabetic patients compared to nondiabetic patients was found: SRR=1.13 (95% CI: 1.04, 1.24). There was a large amount of unexplained heterogeneity of results across studies (I²=95%), but no indication of publication bias. The SRR remained similar when the analysis was restricted to post-menopausal women (SRR=1.12 (95% CI: 0.99, 1.26)). Only two studies reported data in pre-menopausal women. In the 9 studies that adjusted for adiposity, both the SRR and the heterogeneity of results across studies substantially decreased (SRR=1.(95% CI: 0.97, 1.14), I²=21%). In contrast, in the 9 studies that did not adjust for adiposity, both the SRR and the heterogeneity increased (SRR=1.19 (95% CI: 1.01, 1.39), I²=98%). Only two studies included 1,723 and 14 BC cases among type 1 diabetic women. The RR for BC were 0.90 (95% CI: 0.85, 0.94) and RR=1.01 (95% CI: 0.60, 1.71), respectively. This analysis provides evidence for a moderately increased risk of BC in diabetic patients. The effect of the adjustment for BMI on the SRR and on the heterogeneity suggests that the increased BC risk appears to be linked to adiposity, and not to being diabetic. New studies should collect data allowing the assessment of Breast Cancer risk according to the duration of diabetes and treatments that favour weight loss.

Disclosure

M. Bota: None. P. Autier: Other Relationship; Self; Sanofi. P. Boyle: Other Relationship; Self; Sanofi.
Short-Term Weight Loss Undermines Brain Regulation of Food Consumption
Authors: LAM WAI , SEO DONGJU , LACADIE CHERYL , SCHMIDT CHRISTIAN P. , ROSENBERG SAMUEL , HOANG HAI , HWANG JANICE , CONSTABLE TODD , SAVOYE MARY , SINHA RAJITA , SHERWIN ROBERT , BELFORT-DEAGUIAR RENATA
Published: June 2018

Post-prandial hyperglycemia has been shown to suppress appetite by modulating brain activity. We have observed that after weight loss, obese (OB) individuals exhibit increased hunger and decreased brain responses in regions associated with appetite control during hyperglycemia. This study aimed to investigate whether short-term weight loss can affect brain regulation of food intake during hyperglycemia in obesity.

14 healthy OB subjects (8F/6M, age 46±8 years, BMI 33.4±3.5 kg/m2) underwent functional MRI (fMRI) during a hyperglycemic clamp (200 mg/dl). Blood-oxygen-level-dependent (BOLD) brain activity was assessed while subjects viewed high calorie food pictures. Hunger was rated before and after the scan. Immediately after the scan, subjects had an ad libitum test meal. The study was repeated after an 8 week reduced calorie diet that caused 2.9±2.8 kg weight loss (p=0.002).

Hunger significantly increased during the fMRI-clamp study after the diet (p=0.036), but not before the diet. Total calorie intake at the test meal nearly doubled after weight loss (978±492 vs. 1895±189 kcal, p<0.001). This was associated with a significant decrease in brain activity in regions modulating feeding behavior after the diet (p<0.001, Figure 1). These data suggest that short-term dieting diminishes glucose-induced neural control of appetite and food consumption, which may have important implications for weight loss maintenance.

Disclosure

W. Lam: None. D. Seo: None. C. Lacadie: None. C.P. Schmidt: None. S. Rosenberg: None. H. Hoang: None. J. Hwang: None. T. Constable: None. M. Savoye: None. R. Sinha: None. R. Sherwin: Other Relationship; Self; QuintilesIMS, MannKind Corporation. Research Support; Self; Regeneron Pharmaceuticals, Inc.. Other Relationship; Self; ICON plc. R. Belfort-DeAguiar: Research Support; Self; GlaxoSmithKline plc..
Amygdala Glucose-Sensing Neurons Regulate Glucose Metabolism
Authors: DEVARAKONDA KAVYA , BAYNE MITCHELL , ALVARSSON ALEXANDRA , STANLEY SARAH
Published: June 2018

Dysfunction of blood glucose produces health problems with profound consequences. In humans, the central nervous system (CNS) plays a vital role in glucose metabolism. The medial and basomedial amygdalar nuclei contain neurons that alter their firing in response to physiological changes in glucose concentrations and express glucokinase (GK), an enzyme thought to act as a glucose sensor in the CNS. However, little is known about the anatomy and function of these neurons. We have found that amygdala neurons express cfos, a marker of neuronal activation, in response to changes in blood glucose. Using a transgenic mouse with Cre recombinase expression in GK neurons and the retrograde tracer pseudorabies virus (PRV), we have also found that GK-expressing neurons in the amygdala are part of a polysynaptic circuit to peripheral endocrine organs. Finally, modulating the activity of amygdala neurons alters both feeding and glucose metabolism. Together, these data support a role for amygdala glucose-sensing neurons in the regulation of glucose metabolism and behaviors that restore circulating glucose levels to normal.

Disclosure

K. Devarakonda: None. M. Bayne: None. A. Alvarsson: None. S. Stanley: None.
Differential Beta-Cell Response to Intravenous Exenatide (EXEN) and Arginine (ARG) in Prediabetic Subjects with Impaired Fasting Glucose (IFG) and Impaired Glucose Tolerance (IGT)
Authors: TERASAWA TOMOKO , TRIPLITT CURTIS L. , ADAMS JOHN M. , CERSOSIMO EUGENIO , DEFRONZO RALPH A. , CHAVEZ VELAZQUEZ ALBERTO O.
Published: June 2018

Beta cell dysfunction is the main determinant of progression from prediabetes to diabetes. IFG is associated to hepatic insulin resistance, while IGT primarily reflects muscle insulin resistance. The incretin effect is decreased in diabetes, but beta cell response to GLP-1-RA in prediabetic subjects with isolated defects in fasting (i.e., IFG) and postprandial (i.e., IGT) has not been fully characterized. Twenty-five individuals matched for age/BMI: 8 healthy NGT (FPG= 93 mg%±1 2h PG=102±5 mg%, A1c=5.3±0.1%), 11 IFG (FPG=108±2, 2h PG=123±4, A1c=5.7±0.1) and 6 IGT (FPG=95±1 2h PG=162±8, A1c=5.5±0.2) received a two-step hyperglycemic clamp with IV EXENatide and ARGinine infusion. First phase insulin secretion (IS) was calculated as the acute insulin response from 0-15 min; second phase IS and IS after EXEN and EXEN-ARG infusions were calculated as the area under the curve AUC for insulin secretion (IS) during the hyperglycemic clamp (AUC-EXEN and AUC-EXEN/ARG). IS was adjusted for Matsuda index to quantify beta cell function (disposition index). First and second phase insulin secretion in response to EXEN was decreased in both IFG and IGT compared to NGT to a similar extent (p<0.05). IFG individuals exhibited a marked decrease in AUC-EXEN and AUC-EXEN/ARG vs. NGT (52269 vs. 118798, p<0.for EXEN, 15096 vs. 37413 for EXEN-ARG, p<0.01). There was a modest, non-significant decrease in beta cell response in IGT for EXEN and EXEN-ARG vs. NGT (83266 vs. 118798 for EXEN and 22964 vs. 37413 EXEN-ARG, both p=ns).

Conclusion: Individuals with IFG manifest a severe defect in the beta cell response to GLP-1 compared to NGT healthy control subjects. In contrast, the beta cell response to GLP-1 in IGT subject is only minimally impaired. These results suggest that a GLP-1 receptor agonist might be an effective therapy to prevent progression to overt diabetes in subjects with IFG.

Disclosure

T. Terasawa: None. C.L. Triplitt: Speaker0027s Bureau; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Janssen Pharmaceuticals, Inc., Eli Lilly and Company. Consultant; Self; Sanofi, Novo Nordisk Inc.. J.M. Adams: None. E. Cersosimo: Research Support; Self; AstraZeneca, VeroScience, LLC.. Speaker's Bureau; Self; AstraZeneca, Sanofi, Janssen Pharmaceuticals, Inc., Eli Lilly and Company. R.A. DeFronzo: Speaker's Bureau; Self; AstraZeneca, Novo Nordisk Inc.. Advisory Panel; Self; AstraZeneca, Novo Nordisk Inc., Janssen Pharmaceuticals, Inc., Boehringer Ingelheim Pharmaceuticals, Inc., Elcelyx Therapeutics, Inc., Intarcia Therapeutics, Inc.. Research Support; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Janssen Pharmaceuticals, Inc., Takeda Pharmaceuticals U.S.A., Inc.. A.O. Chavez Velazquez: None.
The Role of Incretins and Insulin Clearance in Postprandial Hyperinsulinemia in Black Women—The Federal Women Study
Authors: CHUNG STEPHANIE T. , COURVILLE AMBER B. , ALDANA PAOLA C. , ONUZURUIKE ANTHONY , BERNSTEIN SHANNA , GALVAN-DE LA CRUZ MIRELLA , MABUNDO LILIAN , WALTER MARY , SUMNER ANNE E.
Published: June 2018

Postprandial (PP) hyperinsulinemia may be an important cardiometabolic risk factor. Since black compared to white women have greater hyperinsulinemia after IV glucose testing, they may also be at risk for PP hyperinsulinemia. Therefore, we compared by race and menopausal status, early (0-30min) incremental area under the curve for insulin response (insulin:glucose iAUC30), intact glucagon-like peptide-1 (iGLP-1 iAUC30), glucose-dependent insulinotropic peptide (GIP iAUC30) and insulin clearance (insulin:C-peptide iAUC30) in 1federally employed women without diabetes (48% African American, 14% African immigrant, 38% white; age 44±10y (mean±SD), range 24-62y, BMI 30±5 kg/m2, range 21-45 kg/m2) who underwent a 2 hour mixed meal test (52% carbohydrate, 15% protein, 33% fat). Glucose tolerance status was determined by OGTT. No differences by race in glucose tolerance status, BMI, iGLP-1 iAUC30, or GIP iAUC30 were noted in pre- or postmenopausal women (Table). PP insulin response was higher and insulin clearance was lower in blacks (Table). Overall, PP hyperinsulinemia in pre- and post-menopausal black vs. white women was associated with lower insulin clearance, but not differences in incretin response.Table. Postprandial Glucose, Insulin and Incretin Response by Race and Menopausal Status.Pre-menopausalPostmenopausalBlack (n=49)White (n=29)P- valueBlack (n=18)White (n=12)P-valueBMI (kg/m2)30±432± 60.2029±428±50.24Prediabetes n (%)10 (20)6 (21)0.4213 (72)6 (50)0.50iGLP-1 iAUC30 (pg/mL•min)118±83108±880.3973±5989±770.82GIP iAUC30 (pg/mL•min)2704±15142961±33130.842651±13433661±46890.90Insulin response Log Insulin:Glucose iAUC304.9±6.11.9±1.3<0.013.3±1.71.0±0.4<0.01Insulin clearance Log Insulin:C-peptide iAUC30 0.93±0.031.17±0.05<0.011.13±0.081.26±0.040.28

Disclosure

S.T. Chung: None. A.B. Courville: None. P.C. Aldana: None. A. Onuzuruike: None. S. Bernstein: None. M. Galvan-De La Cruz: None. L. Mabundo: None. M. Walter: None. A.E. Sumner: None.