bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cdk2-Dependent Activation of ß-Cell Metabolism Is Eclipsed by Its Inhibitory Effect on Plasma Membrane Excitability and Insulin Secretion
Authors: SDAO SOPHIA , POUDEL CHETAN , MORTENSEN KARA M. , MERRINS MATTHEW J. 
Published: June 2018

The loss of insulin secretion is a hallmark of diabetes, and it is becoming clear that cell cycle regulators control insulin secretion as well as proliferation. It was recently reported that embryonic deletion of cyclin-dependent kinase 2 (Cdk2) in β-cells (Pdx1-Cre:Cdk2-/-) results in impaired glucose tolerance due to defective insulin secretion (Kim et al., J Biol Chem, 2017), revealing a developmental or perinatal requirement of Cdk2. Here, we show that tamoxifen-inducible deletion of Cdk2 in adult β-cells (MIP-CreER:Cdk2-/-) enhances insulin secretion. Despite these differences, both models of Cdk2 depletion exhibited a strong increase in the glucose dependence of β-cell calcium oscillations. This effect is likely due to the loss of ATP-sensitive K+ (KATP) channels, since kir6.2 transcript was reduced in Cdk2-null β-cells, and pharmacological inhibition of Cdk2 correspondingly reduced KATP channel conductance. These results reveal that Cdk2 inhibits insulin secretion by limiting plasma membrane excitability via KATP. In adult β-cells lacking Cdk2, we also observed a 45% reduction in depolarization-induced exocytosis, indicating that Cdk2 is required for the metabolic amplification of insulin secretion. Within the intermediary metabolic pathways, Cdk2-null β-cells exhibited reductions in glucose-dependent lactate accumulation, mitochondrial membrane potential, and mitochondrial NADH utilization. Together, these studies reveal that Cdk2 transcriptionally limits β-cell membrane excitability and the insulin secretory response, and is required to maintain proper metabolic function.

Disclosure
S. Sdao: None. C. Poudel: None. K.M. Mortensen: None. M.J. Merrins: None.
FSTL3 Inhibition Restores Glucose Responsive Insulin Secretion in Nonfunctional Human Islets
Authors: SCHNEYER ALAN , BROWN MELISSA 
Published: June 2018

Type 2 diabetes results from inadequate insulin production to control blood glucose. To address this need for replacing lost insulin-producing beta cells, most therapeutic development strategies are focused on enhancing functional beta cell number. Fairbanks Pharmaceuticals is pursuing therapies that enhance beta cell function and regeneration and is based on prior research in which inactivation of follistatin-like-3 (FSTL3) resulted in enlarged islets, increased beta cell number, and enhanced insulin secretion. At least some of these new beta cells arose from alpha to beta cell transdifferentiation in FSTL3 knockout mice. Fairbanks has produced a monoclonal antibody (FP-101) that can completely block FSTL3 from binding activin A and B, GDF11, and myostatin that could also disrupt pre-formed and otherwise irreversible complexes. FP-101 was also able to restore glucose-responsive insulin secretion in otherwise non-functional islets taken from HFD-fed mice. To determine if FSTL3 neutralization could be effective in humans, human islets from normal donors were first exposed to elevated glucose (25 nM) for 48-72 hours, a commonly utilized model for glucotoxicity. As expected, this caused loss of glucose response to subsequent GSIS. However, when treated for 24 hours with FP-101, GSIS was restored, indicating that neutralization of FSTL3 might be an effective strategy for restoring function to human non-functional islets. This observation agrees with previous research in which activin treatment directly restored GSIS in human islets from diabetic donors. Taken together with the potential for induction of alpha to beta cell transdifferentiation, these results suggest that neutralization of FSTL3 may have a dual benefit with acute restoration of GSIS in non-functional islets and chronic treatment leading to restoration of beta cell number through enhancement of alpha to beta cell transdifferentiation. In vivo studies will be initiated shortly.

Disclosure
A. Schneyer: Stock/Shareholder; Self; Fairbanks Pharmaceuticals, Inc.. Stock/Shareholder; Spouse/Partner; Fairbanks Pharmaceuticals, Inc.. Employee; Self; Fairbanks Pharmaceuticals, Inc.. M. Brown: None.
Substance Use in Adults with Type 1 Diabetes in the T1D Exchange
Authors: PETRY NANCY , FOSTER NICOLE C. , CENGIZ EDA , TAMBORLANE WILLIAM V. , WAGNER JULIE , POLSKY SARIT 
Published: June 2018

Substance use can have adverse effects on many health conditions, yet little is known about the prevalence of use in individuals with type 1 diabetes (T1D). We evaluated the frequency of use and problem use of psychoactive substances in adults with T1D. Standardized instruments for assessing tobacco, alcohol, and psychoactive substance use were emailed to 4311 adult participants at 69 T1D Exchange Clinic Registry centers. A total of 936 respondents (61% female, 90% non-hispanic white, age 38±16 years) completed the survey. In the sample, tobacco use was reported by 166 (18%) participants in the past year and 51 (5%) daily (Figure 1). Past year alcohol use was reported by 742 (79%) participants, past month use by 592 (63%) and daily or near daily use by 87 (9%). Use of any other psychoactive substance in the past year was reported by 228 respondents (24%), with marijuana being the most commonly used substance (Figure 2). Past year problem use of these substances was noted in 31 (3%) respondents. Adults with T1D in the U.S. use substances at rates that meet or exceed that of the general population; problematic use occurs at rates similar to the general population. These data delineate the need to inquire about regular, intermittent and problematic use of nicotine, alcohol, and other substances in individuals with T1D. A better understanding of the impact of moderate and occasional use of substances on T1D management and clinical outcomes is also needed.

Disclosure
N. Petry: None. N.C. Foster: None. E. Cengiz: Advisory Panel; Self; Novo Nordisk Inc.. Speaker's Bureau; Self; Novo Nordisk Inc.. Advisory Panel; Self; MannKind Corporation, ADOCIA, Arecor. W.V. Tamborlane: Consultant; Self; AstraZeneca, Boehringer Ingelheim GmbH, Eli Lilly and Company, Medtronic MiniMed, Inc., Novo Nordisk Inc., Sanofi, Takeda Pharmaceuticals U.S.A., Inc.. J. Wagner: None. S. Polsky: Research Support; Self; Dexcom, Inc.. Other Relationship; Self; T1D Exchange. Research Support; Self; National Institute of Diabetes and Digestive and Kidney Diseases.
Glucagon Expression Is Regulated by Exendin-4 via CaMKK/AMPK/FoxO1 Pathway in Alpha TC1.6 Cells
Authors: LYU JINGYA , IMACHI HITOMI , FUKUNAGA KENSAKU , SATO SEISUKE , DONG TAO , IBATA TOMOHIRO , KOBAYASHI TOSHIHIRO , MURAO KOJI 
Published: June 2018

Exendin-4, as an analogue of glucagon-like peptide-1, is currently used for the treatment of type 2 diabetes by enhancement of glucose-induced insulin secretion. Preliminary studies showed that secretion of glucagon is inhibited by exendin-4 in vivo and in vitro. However, the detailed mechanism in exendin-4 regulated glucagon expression is not clear.In this study, we firstly proved that exendin-4 decreased the mRNA and protein expression of glucagon in a dose-dependent manner. Following, the promoter activity of glucagon was significantly decreased by exendin-4 and inhibition of Ca2+/calmodulin-dependent protein kinase kinase (CaMKK) signaling pathway by its specific inhibitor, STO-609 rescued this effect. Since glucagon secretion is regulated by AMP-activiated protein kinase (AMPK) and AMPK is able to be activated by CaMKK, we checked the role of AMPK in this process and found exendin-4 activated AMPK at Thr172 site. Additionally, inhibition of AMPK activity by its specific inhibitor or overexpression of domain-negative AMPK canceled the effect of exendin-4 on glucagon promoter activity. As activation of AMPK enhances FoxO transcriptional activity, to further study the transcription of glucagon, we used ChIP assay to demonstrate that transcription factor FoxO1 could bind to glucagon promoter region and exendin-4 decreased glucagon expression via down-regulation of FoxO1. Mutation of FoxO1-binding site in glucagon promoter or silence of FoxO1 canceled the effect of exendin-4 on glucagon expression.
In summary, our results proved that exendin-4 decreases the expression and transcription of glucagon via CaMKK/AMPK/FoxO1 pathway in pancreatic alpha cells, contributing to new knowledge about the regulation of glucagon gene by exendin-4.

Disclosure
J. Lyu: None. H. Imachi: None. K. Fukunaga: None. S. Sato: None. T. Dong: None. T. Ibata: None. T. Kobayashi: None. K. Murao: Research Support; Self; Novartis Pharma K.K..
Profound Hypoglycemia and Corresponding Insulin Levels with Massive Glargine Overdose
Authors: SAEED ZEB I. , ZIA ZAHRA , MARIASH CARY N. 
Published: June 2018

Introduction: Despite widespread use of insulin in diabetes, reports of intentional overdose are rare. Insulin kinetics are different in acute poisoning from that in therapeutic doses in part due to delayed absorption from the injection site and reduced clearance. We present a case of insulin glargine overdose where the peak serum insulin levels were observed more than 24 hours after presentation with persistent hypoglycemia for over 100 hours from initial presentation.
Case: An unidentified middle-aged female was found comatose in an abandoned house by emergency medical services. She was hemodynamically stable except hypothermic at 34°C. Initial point of care glucose was undetectable and 25mg/dL after 1mg IM glucagon administration. She was given 75ml of Dextrose 50% intravenously and intubated in the field for airway protection. Serum glucose on hospital arrival was &lt;20mg/dL, necessitating the initiation of dextrose 5%, then 10% and eventually continuous infusion of dextrose 40% (D40) via central venous catheter for persistent hypoglycemia. Evaluation revealed serum insulin level of 362 mCU/mL (4-30) with C-peptide 0.3ng/ml (1.4-4.4) when serum glucose was 51, suspicious for exogenous insulin use. Renal and liver function tests were normal, AM cortisol was appropriate and oral hypoglycemic agent panel was negative. Peak total serum insulin levels were 1395mCU/ml with free insulin levels 1022mCU/ml 36 hours after initial presentation. With exaggerated insulin levels, testing for insulin antibodies was done which was negative. D40 drip was weaned off slowly over the next few days and discontinued at 102 hours after arrival. Patient was extubated soon afterwards and admitted to intentional overdosing with over 5000units (5-6 vials) of Lantus. She was admitted to a psychiatry facility for management of depression and suicidality.
Conclusion: Profound and persistent hypoglycemia can be observed for days due to altered pharmacokinetics after massive doses of long-acting insulins.

Disclosure
Z.I. Saeed: None. Z. Zia: None. C.N. Mariash: None.
A Coronary Artery Calcium Score (CACS) Higher than 100 Agatston Units Is Associated with a Profile of Very High Cardiovascular Risk in the Diabetic Population
Authors: VALENSI PAUL , BANU ISABELA , FYSEKIDIS MARINOS , COSSON EMMANUEL 
Published: June 2018

Rationale: CACS can improve the cardio-vascular risk (CVR) estimate and select the patients eligible for further cardio-vascular investigations. We aimed to examine the relationship between a CACS ≥100 Agatston units (AU) and integrators of CVR in the diabetic population.
Patients and Methods: CACS was measured in type 2 diabetic patients without symptoms, history of coronary disease or ECG ischemic changes presenting ≥2 additional CVR factors. We included 338 patients with very high CVR (age 61±9 years, diabetes duration 15 ± 8 years, insulin treated 47%, hypertension 86%, dyslipidemia 88%, smokers 22%, lower limb artery disease 9.5% and/or carotid atheroma 5.5%, chronic kidney disease 48%). Silent myocardial ischemia (SMI) was assessed using stress myocardial scintigraphy. Artery stiffness indexes (pulse wave velocity (PWV) and augmentation index (AIx@75)) and Buckberg index of myocardial perfusion (SEVR) were measured with applanation tonometry (Sphygmocor®).
Results: Compared with the patients with CACS &lt;100 AU, the 139 patients (41%) with CACS ≥100 were less treated by metformin (73 vs. 88%, p&lt;0.001) or GLP-1-receptor agonists (18 vs. 28%, p&lt;0.05), but more treated by anti-hypertensive drugs, statins (79 vs. 70%, p=0.058) or fibrates (8.5 vs. 3.7%, p=0.072), with lower LDL-cholesterol levels (2.1±0.9 vs. 2.4±0.9 mmol/l, p&lt;0.01). SMI prevalence (21.6 vs. 11.5%, OR 2.1[1.2-3.8], p&lt;0.05), NT-proBNP (201±375 vs. 73±136 mg/L, p&lt;0.01) and PWV (11.0±2.7 vs. 9.4±3.6 m/sec, p&lt;0.01) were higher. However, the rate of elevated PWV (compared to normative data considering age and blood pressure), central pulse pressure and SEVR were very close in the two groups while AIx@75 was lower in the patients with CACS≥100 (22.1±9.3 vs. 26.4±10.0, p&lt;0.01).
Conclusion: The CACS ≥100 is a marker of very high CVR associated with a higher SMI prevalence and NT-proBNP levels. Artery stiffness and SEVR were not altered.

Disclosure
P. Valensi: None. I. Banu: None. M. Fysekidis: None. E. Cosson: Consultant; Self; Lilly France. Board Member; Self; Novartis France. Consultant; Self; Roche Diagnostics France. Board Member; Self; Ascensia Diabetes Care. Consultant; Self; Bezins France. Board Member; Self; MSD France.
Next Generation of Spontaneous Diabetic Model of Fatzo Mice with Intact Leptin Signaling Develop Nephropathy after High-Fat and High-Sucrose Induction
Authors: SUN GAO , ZHANG GUODONG , WANG YIXIN 
Published: June 2018

Introduction: Progressive albuminuria and bi-phasic changes in glomular filtration rate (GFR) are hall marks of functional deterioration of the kidney in diabetic nephropathy. However, not all diabetic rodent models can capture the development of such changes in the kidney. FATZO, a new generation of diabetic mouse model with intact leptin signaling pathway shows all the metabolic dysfunctions that mimic human patients such as obesity, dyslipidemia, diabetes and NASH etc. Here, we sought to further characterize the model for the evaluation of its development in diabetic nephropathy.
Method: Male FATZO mice on 50diet or on western diet with addition of 10% fructose (WD+fru) from age of 11 weeks were subject to monthly urine collection for albumin and creatinine measurement for 28 weeks, after which animals were treated with Lisinopril (15 mg/kg) and pioglitazone (20 mg/kg) daily for 6 weeks (n=8 for each group). Animals were also monitored for GFR using a subcutaneous monitoring device (Medibeacon, US).
Results: Animals on WD+fru were heavier than those on 50diet. Notably, WD+fru markedly elevated urine albumin levels compared to 50diet in FATZO mice which resulted in higher albumin/creatinine ratio and urine albumin excretion rate (UAE) from 2 weeks on diet, while lisinopril treatment for 7 weeks could reduce the levels respectively. In addition, GFR was slightly elevated after 6 weeks of diet induction, which could be normalized by either pioglitazone or lisinopril treatment.
Conclusion: We have created a mouse model with progressive albuminuria and elevated GFR that can be reversed by angiotensin-converting-enzyme (ACE) inhibitor. The model with associated dysmetabolic phenotypes including obesity and dyslipidemia can be used as an ideal tool for studying antidiabetic nephropathy treatment.

Disclosure
G. Sun: None. G. Zhang: None. Y. Wang: None.
Exendin-4 Ameliorates High-Glucose-Induced Fibrosis by Inhibiting the Secretion of miR-192 from Injured Renal Tubular Epithelial Cells
Authors: JIA YIJIE , XUE YAO-MING 
Published: June 2018

Extracellular vesicles (EVs), which contain microRNA (miRNA), constitute a novel means of cell communication that may contribute to the inevitable expansion of renal fibrosis during diabetic kidney disease (DKD). Exendin-4 is effective for treating DKD through its action on GLP-1R. However, the effect of exendin-4 on EVs miRNA expression and renal cell communication during the development of DKD remains unknown. In this study, we found that EVs derived from exendin-4 and high-glucose (Ex-HG)-pretreated HK-2 cells, which was taken up by normal HK-2 cells, resulted in decreased levels of FN and Col-I compared with those treated with HG pretreated HK-2 cells derived EVs. Furthermore, we found this may contribute to a decrease in miR-192 in both HK-2 cells and EVs after exendin-4 treatment in a p53-dependent manner. Besides, we found that the amelioration of renal fibrosis by exendin-4 occurs through a miR-192-GLP-1R pathway, indicating a new pathway by which exendin-4 regulates GLP-1R. The results of this study suggest that exendin-4 can inhibit the transfer of EVs miR-192 from HG-induced renal tubular epithelial cells to normal cells, thus inhibiting GLP-1R down-regulation and protecting renal cells. This study reports a new mechanism by which exendin-4 exerts a protective effect against DKD.

Disclosure
Y. Jia: None. Y. Xue: None.
Inhibition of Myeloperoxidase and MPO Reverses Microvascular Insulin Resistance in High-Fat Diet (HFD)-Fed Rats
Authors: BARRETT EUGENE , AYLOR KEVIN W. , CHAI WEIDONG , GAN LI-MING 
Published: June 2018

Chronic, low-level inflammation underlies much of the vascular and metabolic insulin resistance associated with HFD. Release of MPO by leukocytes may be an early contributor to the inflammatory process and endothelial dysfunction that accompanies HFD feeding. Plasma MPO concentrations are increased in both human obesity and diabetes and HFD-fed rats. However, the impact of MPO on microangiopathy and its relation to insulin resistance is unclear. We tested whether AZD5904 (a potent, irreversible inhibitor of MPO, AstraZeneca) improves endothelial function and vascular insulin responses in insulin resistant, adult male SD rats fed a HFD (60% calories from fat) for 2 weeks. HFD fed rats received vehicle (n=8) or AZD5904 (75 µmol/kg/day, n=10) via an Alzet Mini pump for 2 weeks. A 3rd group of rats (n=8, vehicle alone) were fed a chow diet for 2 weeks. After 2 weeks of HFD or control diet, rats were fasted overnight and received a 2-hour euglycemic insulin clamp (3 mU/kg/minutes). Hindleg muscle microvascular perfusion was assessed using contrast-enhanced ultrasound and insulin-stimulated steady-state whole body glucose disposal was determined. Insulin infusion increased muscle microvascular perfusion by 2-3 fold in chow fed rats (p&lt;0.05). HFD feeding abolished insulin-induced microvascular recruitment in muscle, and decreased insulin-mediated glucose disposal by ∼45% (p&lt;0.01). Simultaneous treatment with AZD5904 fully restored insulin-mediated muscle microvascular perfusion (p&lt;0.05) in HFD rats, but did not improve insulin-stimulated glucose disposal in HFD-fed rats. We conclude that inhibition of MPO with AZD5904specifically reverses muscle microvascular insulin resistance in HFD rats. This implicates MPO as a significant contributor to HFD-induced endothelial inflammation and suggests a role for MPO inhibition to improve microvascular complications in patients with vascular insulin resistance.

Disclosure
E. Barrett: None. K.W. Aylor: None. W. Chai: None. L. Gan: Employee; Self; AstraZeneca.
MicroRNA Drivers of the Effects of High-Fat Diet and Bariatric Surgery on the Intestine
Authors: SETHUPATHY PRAVEEN 
Published: June 2018

High-fat diet (HFD) leads to obesity and insulin resistance, which are key risk factors for type 2 diabetes (T2D). Many studies have investigated the effects of HFD on several metabolic tissues, but the intestine is highly underexplored. The small intestine is the primary site of the positive metabolic effects of the most successful pharmacologic treatments (metformin) and surgical interventions (bariatric surgery) for T2D. The innermost cell layer of the small intestine is the epithelium, which is the most rapidly renewing tissue in the body and is comprised of several cell types that mediate nutrient absorption and energy homeostasis. The high renewal rate for these cells is driven by a small but highly proliferative population of intestinal stem cells (ISCs). In this study, we showed that an obesogenic HFD significantly increases proliferation of ISCs, and alters allocation of ISCs to different lineages in mice. To define the molecular mechanisms that underpin these effects, we performed whole transcriptome analyses (both small RNA-seq to profile microRNAs (miRNAs) and RNA-seq for long, non-coding RNAs and mRNAs) in Lgr5+ ISCs. We demonstrated that HFD shifts the miRNA profile of ISCs toward that of enterocytes, the cells involved in nutrient absorption. Further bioinformatics analysis revealed that this shift is driven primarily by changes in two miRNAs, miR-194 and miR-375. Specifically, HFD suppresses miR-375 by over five-fold (P &lt; 0.05). Notably, follow-up studies showed that vertical sleeve gastrectomy, which reverses the effects of HFD, significantly rescues the levels of miR-375 in Lgr5+ ISCs. We hypothesized that suppression of miR-375 promotes ISC proliferation and allocation to enterocytes. To test this hypothesis, we generated miR-375-/- mice and showed that loss of miR-375 in vivo leads to a marked increase in ISC proliferation and villus height, mimicking the effects of HFD. Currently we are investigating whether miR-375 is essential for the effects of bariatric surgery.

Disclosure
P. Sethupathy: None.
The Relationship between Sodium Intake and Albuminuria in U.S. Adults with Chronic Kidney Disease With and Without Diabetes
Authors: OZIEH MUKOSO N. , GARACCI EMMA , WALKER REBEKAH J. , EGEDE LEONARD E. 
Published: June 2018

Introduction: Low sodium diet has been shown to have blood pressure lowering effects and as such promising effect on slowing CKD progression. The aim of this study is to examine if the relationship between sodium intake and albuminuria differs by diabetes status in patients with CKD.
Methods: We used National Health and Nutrition Examination Survey for adults ≥ age 20 between 2007-2014. Primary outcome variable was Albumin-to-creatinine ratio (ACR). CKD stage was based on estimated glomerular filtration rate and Albumin-to-creatinine ratio. Sodium (Na) intake was calculated as the sum of total dietary and supplement intake. Diabetes and prediabetes were self-reported. Statistical analysis was performed using survey commands to provide nationally representative estimates. A generalized linear regression model was run adjusting for relevant covariates using log transformed ACR, with estimates exponentiated to provide mean ratios (MR).
Results: About 3535 adults, representing 28,787,552 U.S. adults were included in the study. The mean Na intake for the cohort was 3,082mg (median 2,783mg) and 26% of the cohort had sodium intake &lt;2,000mg. In the unadjusted analysis, an increase of 1,000mg Na was significantly associated with higher ACR (MR=1.04, 95% CI 1.00-1.08). In addition, non-Hispanic blacks (NHB) (MR=1.82, 95% CI 1.52-2.19) and Hispanics (MR=2.31, 95% CI 1.96-2.72) had higher ACR compared to non-Hispanic whites (NHW). After adjusting for relevant covariates including CKD stage, participants with diabetes were more likely to have ACR (MR=1.52, 95% CI 1.28-1.80) while the relationship between Na intake and ACR lost significance (p=0.05).
Conclusions: For every 1000mg increase in sodium intake participants were 4% more likely to have albuminuria. NHB were 82% and Hispanics were 131% more likely to have albuminuria compared to NHW. Future prospective studies should focus on examining the relationship between sodium intake and albuminuria among minorities.

Disclosure
M.N. Ozieh: None. E. Garacci: None. R.J. Walker: None. L.E. Egede: Research Support; Self; National Institute of Diabetes and Digestive and Kidney Diseases. Advisory Panel; Self; Novo Nordisk Inc..