bluuebunny/crossref_metadata_2025 huggingface dataset:
197-OR: IL-6 Protects Pancreatic ß Cells from Oxidative Stress via NRF2 Mitochondrial Translocation and Mitophagy
Authors: MARASCO MICHELLE , CONTEH ABASS M. , MURALIDHARAN CHARANYA , PFEIFER ELIZABETH , LINNEMANN AMELIA K.
Published: June 2019

Glucose-stimulated insulin secretion by pancreatic β-cells results in a high level of metabolic activity and ROS production. Excess ROS can cause cellular damage leading to apoptosis. We recently reported that the cytokine interleukin 6 (IL-6) stimulates autophagy and protects β-cells from ROS-induced damage and apoptosis via the autophagic degradation of an antioxidant response repressor, KEAP1. This results in increased protein levels of the master antioxidant factor, NRF2. IL-6 also stimulates early markers of mitophagy in a NRF2-dependent manner. Interestingly, these effects are associated with noncanonical translocation of NRF2 to the mitochondria. Here, we set out to validate these findings and determine how NRF2 mitochondrial translocation is regulated. Using fluorescence imaging of mt-keima, we demonstrate that IL-6 stimulates mitophagy. This occurs without effects on mitochondrial function as measured by the Seahorse MitoStress Test. We also find that IL-6 rapidly stimulates NRF2 mitochondrial translocation, an effect that does not occur in response to treatment with hydrogen peroxide or a chemical inhibitor of KEAP1. These data indicate that liberating NRF2 from KEAP1 alone does not lead to NRF2 mitochondrial translocation, suggesting that IL-6 regulates NRF2 localization by additional mechanisms. NRF2 has extensive post-translational modifications, some of which are associated with nuclear localization. Therefore, we hypothesized that IL-6 induces specific NRF2 post-translational modifications that promote mitochondrial translocation. Indeed, we found that IL-6 stimulates serine phosphorylation on NRF2. Based on our findings described here, we propose that selective modification of NRF2 regulates its distinct subcellular localization and that selective translocation determines the mechanism of NRF2-mediated antioxidant response that functions to reduce ROS and restore cellular homeostasis in pancreatic β-cells.

Disclosure

M. Marasco: Employee; Spouse/Partner; Eli Lilly and Company. A.M. Conteh: None. C. Muralidharan: None. E. Pfeifer: None. A.K. Linnemann: None.

Funding

National Institutes of Health (K01DK102492), (R03DK115990 to A.K.L.)
1974-P: Identification of a Dual-Action Small Molecule with Potent Antidiabetic Activity
Authors: WANG YAO , LUO JING , ALKHALIDY HANA A. , XU BIN , LIU DONGMIN
Published: June 2019

Type 2 diabetes (T2D) is a result of insulin resistance and pancreatic β-cell dysfunction. Therefore, identifying agents that simultaneously reverse these two defects could be a novel strategy leading to more effective prevention and treatment of T2D. Recently, we generated a small molecule elenolic acid moiety (EA). Here, we report that oral administration of EA normalized glycemia, glucose tolerance, insulin sensitivity, and hepatic glucose production in high-fat diet (HFD)-induced obese mice. These metabolic and antihyperglycemic effects of EA treatment were associated with increased circulating GLP-1 and peptide YY concentrations, but reduced blood insulin, leptin, and lipid levels. In addition, EA slowed gastric emptying and reduced food intake, body weight, and fat mass in HFD-fed obese mice. In vitro, EA directly induces glucagon-like peptide-1 (GLP-1) release from intestinal L-cells via a Gαq/phospholipase C-mediated mechanism. It also suppresses glucose production from HepG2 cells and stimulates glucose uptake in primary human skeletal muscle cells. These data suggest that EA may be a novel agent for developing drug to treat T2D.

Disclosure

Y. Wang: None. J. Luo: None. H.A. Alkhalidy: None. B. Xu: None. D. Liu: None.

Funding

National Institutes of Health (1R01AT007077, 1R01AT007566)
1976-P: Physiological Effects of GIP(1-30)NH2 in Healthy Subjects
Authors: KROGH LIVA S.L. , GASBJERG LÆRKE S. , STENSEN SIGNE , SKOV-JEPPESEN KIRSA , ROSENKILDE METTE MARIE , HARTMANN BOLETTE , VILSBØLL TINA , HOLST JENS J. , KNOP FILIP K.
Published: June 2019

The gut-derived incretin hormone glucose-dependent insulinotropic polypeptide (GIP) circulates in at least two active forms: GIP(1-42), which besides its insulinotropic effect during hyperglycemia stimulates glucagon secretion at low plasma glucose (PG) levels and decreases bone resorption, and GIP(1-30)NH2. In vitro and rodent studies has shown similar physiological effects of GIP(1-30)NH2 and GIP(1-42), but effects in humans remain unexplored. Here, we infused GIP(1-42) and GIP(1-30)NH2 in humans to establish the physiological effects of GIP(1-30)NH2.

On three separate days, 10 healthy men (mean age 23 (range 20-28) years, BMI 22.4 (20.0-25.2) kg/m2) received intravenous infusions of GIP(1-42), GIP(1-30)NH2 and saline, respectively. Both peptides were infused at 4 pmol/kg/min during 200 minutes. After 20 minutes of infusion, PG was clamped at the fasting PG level (FPG) for 60 minutes, followed by 60 minutes at FPG × 1.5, and lastly 60 minutes at FPG × 2.

There were no differences in PG levels between the three interventions, but significantly more glucose was needed for the clamp with GIP(1-42) compared to saline (P = 0.022). Plasma levels of GIP(1-30)NH2 reached a mean (± SD) of 31.4 ± 29.9 pmol/l and GIP(1-42) of 97.8 ± 27.9 pmol/l. Despite this difference, both infusions resulted in robust and glucose-dependent insulin responses (as assessed by serum C-peptide) with no differences between the two peptide infusions (P = 0.187), and at FPG level only GIP(1-30)NH2 resulted in higher glucagon levels than saline (P = 0.0302). At 180 minutes, the bone resorption marker carboxy-terminal collagen I crosslinks (CTX) was suppressed to 61 ± 13% of baseline values during saline, 42 ± 16% during GIP(1-30)NH2, and 29 ± 6% during GIP(1-42) (P < 0.001).

We conclude that, like GIP(1-42), GIP(1-30)NH2 is a potent insulinotropic (at high PG levels), glucagonotropic (at low PG levels) and bone resorption-inhibiting hormone in healthy subjects.

Disclosure

L.S.L. Krogh: None. L.S. Gasbjerg: Stock/Shareholder; Self; Antag Therapeutics. S. Stensen: None. K. Skov-Jeppesen: None. M.M. Rosenkilde: Consultant; Self; Antag Therapeutics. B. Hartmann: None. T. Vilsbøll: None. J.J. Holst: Advisory Panel; Self; Novo Nordisk A/S. F.K. Knop: Advisory Panel; Self; AstraZeneca, MedImmune, Merck Sharp & Dohme Corp., Mundipharma, Novo Nordisk A/S, Sanofi. Consultant; Self; Amgen Inc., Carmot Therapeutics, Novo Nordisk A/S. Research Support; Self; AstraZeneca, Novo Nordisk A/S. Speaker's Bureau; Self; AstraZeneca, MedImmune, Merck Sharp & Dohme Corp., Mundipharma, Norgine, Novo Nordisk A/S.
198-OR: Role for the Cationic Amino Acid Transporter Slc7a2 in Alpha-Cell Proliferation and Islet Hormone Secretion
Authors: SPEARS ERICK , SHOU MATTHEW , SIV WALTER A. , DAI CHUNHUA , CHEN WENBIAO , POWERS ALVIN C. , DEAN DANIELLE
Published: June 2019

Interrupting glucagon receptor signaling results in hyperaminoacidemia, which stimulates alpha cell hyperplasia. Arginine, a potent secretagogue for both insulin and glucagon, is required for hyperaminoacidemia-stimulated alpha cell proliferation. To investigate the role of arginine transport, we compared the expression of amino acid transporters in published datasets of sorted mouse and human islet cells and found that Slc7a2, cationic amino acid transporter, is the most highly expressed amino acid transporter in both mouse and human alpha cells and that its expression is three-fold higher in alpha cells than in beta cells. Following glucose/arginine injection, global Slc7a2 knockout mice (Slc7a2-/-) had 20% higher blood glucose (+/+ vs. -/-: 412±23 vs. 517±25mg/dL, n=11-12, p=0.004), 80% lower serum insulin (3.7±0.6 vs. 0.7±0.4nM, p=0.0008) and 59% lower serum glucagon (64.3±23.1pM vs. 26.3±11.4pM, p=0.009) than Slc7a2+/+ animals. Slc7a2+/- mice had 55% decreased insulin levels (+/+ vs. +/-: 3.7±0.6 vs. 1.7±0.3nM, n=8, p=0.012), but showed no difference in serum glucose or glucagon levels, indicating that Slc7a2 expression may be rate limiting for beta cell, but not alpha cell, function. Isolated islets from Slc7a2-/- mice had normal morphology, but reduced high amino acid-stimulated alpha cell proliferation by 90% and 58% in Slc7a2-/- and Slc7a2+/- islets, respectively (+/+ vs.-/-: 3.7±1.7 vs. 0.4±0.2%, p=0.007, n=4; +/+ vs. +/-: 3.7±1.7 vs. 1.5±0.6%, p=0.038, n=4). Knockdown with Slc7a2 shRNA in the aTC1-6 mouse alpha cell line also decreased proliferation. Taken together, these data indicate a central role for Slc7a2 in amino acid-stimulated alpha cell proliferation and glucagon and insulin secretion.

Disclosure

E. Spears: None. M. Shou: None. W.A. Siv: None. C. Dai: None. W. Chen: None. A.C. Powers: None. D. Dean: None.
1980-P: A Characterization of Postprandial Glucose Metabolism and Incretin Hormone Responses in Patients with Bile Acid Malabsorption
Authors: KÅRHUS MARTIN L. , SONNE DAVID P. , THOMASEN MARTIN L. , HOLST JENS J. , VILSBØLL TINA , BRØNDEN ANDREAS , KNOP FILIP K.
Published: June 2019

Bile acid malabsorption (BAM) is characterized by an excessive spill-over of bile acids to the colon leading to bile acid-induced diarrhea; the condition is usually treated with bile acid sequestrants. Bile acids have been demonstrated to modulate the secretion of the incretin hormone glucagon-like peptide 1 (GLP-1) and the aim of this study was to characterize postprandial glucose metabolism and incretin hormone responses in patients with BAM. Twelve patients with BAM (6 women; mean age 39.1 (SD 13.2); mean BMI 28.4 kg/m2 (SD 1.2); HbA1c 31.4 (SD 3.7)) and 12 healthy gender, age, BMI and HbA1c-matched controls (6 women; mean age 39.3 (SD 15.6); mean BMI 29,1 kg/m2 (SD 1.1); HbA1c 31.0 (SD 2.8)) were subjected to two 4-hour standardized liquid meal tests with double-blinded single-dose administration of the bile acid sequestrant colesevelam (3.75 g) and placebo, respectively, performed on separate days, and in randomized order. Fasting and postprandial plasma GIP and GLP-1 concentrations were comparable among patients with BAM and control subjects and unaffected by colesevelam administration. Peak plasma glucose concentrations were higher in BAM patients vs. control subjects, but area under curve for plasma glucose did not differ between the two groups. Patients with BAM exhibited significantly higher postprandial serum C-peptide concentrations and hyperglucagonemia compared to controls. Single-dose colesevelam had no effect on postprandial glucose or glucagon excursions in any of the groups but decreased the postprandial C-peptide response in BAM patients. Patients with BAM are characterized by elevated serum C-peptide concentrations and hyperglucagonemia whereas postprandial glucose tolerance and GLP-1 and GIP responses are similar to healthy controls.

Disclosure

M.L. Kårhus: None. D.P. Sonne: None. M.L. Thomasen: None. J.J. Holst: Advisory Panel; Self; Novo Nordisk A/S. T. Vilsbøll: None. A. Brønden: Other Relationship; Self; AstraZeneca. F.K. Knop: Advisory Panel; Self; AstraZeneca, MedImmune, Merck Sharp & Dohme Corp., Mundipharma, Novo Nordisk A/S, Sanofi. Consultant; Self; Amgen Inc., Carmot Therapeutics, Novo Nordisk A/S. Research Support; Self; AstraZeneca, Novo Nordisk A/S. Speaker's Bureau; Self; AstraZeneca, MedImmune, Merck Sharp & Dohme Corp., Mundipharma, Norgine, Novo Nordisk A/S.

Funding

Novo Nordisk Foundation
1984-P: Optic Atrophy 1 Deletion in Brown Adipose Tissue Induces Browning of White Fat by Inducing FGF-21
Authors: ALAMBERT RENATA PEREIRA , TADINADA SATYA MURTHY , ABEL E. DALE
Published: June 2019

Optic Atrophy 1 (OPA1) is a mitochondrial inner membrane protein that regulates inner mitochondrial membrane fusion, cristae structure and respiratory capacity. Mitochondria are critical for the thermogenic activation of brown adipocytes. However, the role of OPA1 and mitochondrial dynamics in brown adipose tissue (BAT) physiology and in systemic metabolism is incompletely understood. We generated mice lacking OPA1 specifically in BAT by crossing mice floxed for the Opa1 genewith mice harboring the Cre recombinase under the control of the Ucp1promoter (OPA1 BAT-KO). Although mitochondrial respiratory capacity was reduced in mitochondria isolated from BAT of OPA1 BAT-KO, mitochondria respirations were elevated in the inguinal fat pad of these mice, which correlated with increased UCP1 protein levels and induction of thermogenic genes, consistent with browning of white adipose tissue (WAT). OPA1 BAT-KO mice also had elevated energy expenditure and reduced WAT mass. We, then, hypothesized that a BAT-derived secreted factor, or batokine, mediated these systemic effects. Upon mRNA expression analysis of a panel of batokines in OPA1-BAT KO mice, we found Fibroblast Growth Factor 21 (FGF-21) to be significantly elevated in BAT. We, therefore, generated OPA1/FGF-21 BAT-DKO mice. DKO mice had normalized WAT mass and lacked the induction of thermogenic genes in WAT.

In conclusion, OPA1 deletion in BAT results in increased FGF-21 expression, which induces browning of WAT to increase energy expenditure and promote leanness.

Disclosure

R. Pereira Alambert: None. S. Tadinada: None. E. Abel: None.

Funding

American Heart Association
1991-P: Mammary Tumors Increase Diet-Induced Obesity and Insulin Resistance in Female MMTV-PyMT Mice
Authors: NOH HYE LIM , KANG HEE JOON , MERCADO-MATOS JOSE , FRIEDLINE RANDALL H. , SUK SUJIN , HU XIAODI , TRAN DUY A. , TAUER LAUREN A. , KO MIN-JI , CHOI JUNGEUN , LUONG THAVANVOTEY , TSUCHIDA YURAN , SHAW LESLIE M. , KIM JASON K.
Published: June 2019

Diabetes and cancer share multiple risk factors including obesity and insulin resistance, but the potential relationship between these two major diseases is unknown. Here we examined the metabolic effects of high-fat diet (HFD) feeding in female MMTV-PyMT mice, a breast cancer model expressing the polyoma middle T antigen driven by the Mouse Mammary Tumor Virus promoter. Female PyMT and wild type (WT) mice were fed a HFD (55% fat by calories) for 4 weeks starting at 4∼5 weeks of age (n=10-12/group). During HFD, PyMT mice became more obese than WT mice with significant increases in both fat and lean mass (Figure 1; *P<0.05). This was largely due to ∼5% and 30% decreases in energy expenditure and physical activity, respectively, in HFD-PyMT mice (Figure 2). Food intake did not differ between groups. Hyperinsulinemic-euglycemic clamps were performed to measure glucose metabolism in awake mice. HFD-PyMT mice showed increased insulin resistance with ∼25% decreases in glucose infusion rate and whole body glucose turnover compared to HFD-WT mice (Figure 3). Increased insulin resistance was due to significantly reduced glucose uptake in white adipose tissue (Figure 4).

In conclusion, these results demonstrate that tumor-bearing female PyMT mice developed increased obesity and insulin resistance after high-fat feeding, and our findings implicate an important relationship between obesity, cancer, and type 2 diabetes.

Disclosure

H. Noh: None. H. Kang: None. J. Mercado-Matos: None. R.H. Friedline: None. S. Suk: None. X. Hu: None. D.A. Tran: None. L.A. Tauer: None. M. Ko: None. J. Choi: None. T. Luong: None. Y. Tsuchida: None. L.M. Shaw: None. J.K. Kim: None.

Funding

National Institutes of Health (5U2C-DK093000)
20-LB: Endothelial Cell Metabolomics Identifies ?-glutamyl Cycle Alterations Associated with the 1q25 T2D-Specific Cardiovascular Locus
Authors: PIPINO CATERINA , SHAH HETAL , PARK KYOUNGMIN , MONTI STEFANO , MENDONCA CHRISTINE , KING GEORGE L. , PANDOLFI ASSUNTA , DORIA ALESSANDRO
Published: June 2019

A variant on chromosome 1q25 (rs10911021) has been previously associated with coronary artery disease (CAD) in individuals with T2D. In human umbilical vein endothelial cells (HUVECs), the 1q25 risk allele (‘C’) was found to be associated with decreased expression of the adjacent gene GLUL encoding the enzyme glutamine synthase converting glutamate to glutamine. To further investigate the mechanisms through which the 1q25 locus modulates CAD risk in T2D, we performed a global metabolomics study (LC-MS, Metabolon) in 62 HUVECs (TT=11, CT=21, CC=30). Among 597 metabolites detected in HUVEC lysates, 23 attained p<0.005 for association with the 1q25 risk allele. Through an unbiased hierarchical cluster analysis, these 23 metabolites could be subdivided into four clusters - two upregulated and two downregulated in carriers of the risk allele. The two upregulated clusters included a group of γ-glutamyl amino acids (γ-glutamylthreonine, γ-glutamylleucine, and γ-glutamylvaline) and a heterogeneous group of metabolites including isoleucylglycine and tyrosylglycine. The two downregulated clusters included a group of polyunsaturated fatty acid (PUFA) derivatives, such as DHA-choline and N-arachidonoyl taurine, and a cluster of several sphingomyelins. Consistent with the higher γ-glutamyl amino acids, the risk allele was associated with increased ophthalmate (p=0.04), a marker of γ-glutamyl cycle malfunction, and decreased S-lactoylglutathione (p=0.016), a possible sign of defective detoxification of the AGE-precursor methylglyoxal.

In summary, we have identified several metabolic pathways potentially mediating the 1q25 locus effect on CAD risk in T2D. These include impairment of the γ-glutamyl cycle, possibly increasing susceptibility to oxidative stress, and downregulation of PUFA derivatives and sphingomyelins. Further studies of these pathways may lead to the identification of novel therapeutic targets to reduce CAD risk in T2D.

Disclosure

C. Pipino: None. H. Shah: None. K. Park: None. S. Monti: None. C. Mendonca: None. G.L. King: Research Support; Self; Sanofi. A. Pandolfi: None. A. Doria: Research Support; Self; Sanofi-Aventis.

Funding

Sanofi-Aventis
2001-P: Thermoneutrality Dissociates Glucose Tolerance from Insulin Sensitivity in Rats
Authors: KELLER AMY C. , KNAUB LESLIE , HULL SARA E. , SCALZO REBECCA L. , WALKER LORI A. , REUSCH JANE E.B.
Published: June 2019

Thermoneutrality (TN) has been used to induce weight gain in rodent models of obesity. We hypothesized that TN would potentiate high-fat diet (HFD) impairment of vascular reactivity, diminish vascular mitochondrial function, and induce insulin resistance. Male rats aged 5-7 weeks were housed at room temperature (RT=23 C) or TN (29 C) and fed a low-fat diet (LFD) or HFD for 10-16 weeks. Aortic vasomotion and mitochondrial respiration (Oroboros O2k) were measured at the end of the study. Intraperitoneal glucose and insulin tolerance tests (IP-GTT and IP-ITT) were done at baseline and endpoint. Animals housed at TN had impaired vasodilation regardless of diet (effect of temperature, p<0.01). We also observed an elevated constriction response to phenylephrine in TN animals (interaction of temperature x concentration, p=0.023). Animals on HFD housed in both environments had diminished mechanical constriction (effect of diet, p=0.007). Animals housed at TN had elevated rates of both ADP-independent and dependent respiration (effect of temperature, p<0.001 for both). Metabolic profiling revealed that TN lowered glucose tolerance (interaction of temperature x time p<0.001). Fasting glucose was lower at endpoint in TN rats (interaction of time x temperature, p=0.004). Unexpectedly, glucose uptake improved in TN during an IP-ITT but worsened with RT (effect of temperature, p=0.023). IP-ITT insulin clearance in TN animals at endpoint was impaired (interaction of time x diet p=0.002). There was a significant effect of temperature on fat pad weight (p=0.034) with no effect on overall weight. In sum, TN provides a robust tool for inducing vascular dysfunction. A TN climate led to significant alterations in metabolism. Further experiments are underway to clarify potential mechanisms for the unexpected TN-mediated increased insulin sensitivity with concomitant glucose intolerance.

Disclosure

A.C. Keller: None. L. Knaub: None. S.E. Hull: None. R.L. Scalzo: None. L.A. Walker: None. J.E.B. Reusch: Board Member; Self; American Diabetes Association. Other Relationship; Self; Merck & Co., Inc.

Funding

U.S. Department of Veterans Affairs (BX003185-01A2, BX002046, CX001532); National Institutes of Health (5T32HL007171)
2005-P: Transgenic Overexpression of Human Chimeric Intestinal Alkaline Phosphatase (IAP) Improves Plasma Lipid Profile and Attenuates Western Diet (WD)-Induced Atherosclerosis in LDLR-/- Mice
Authors: GHOSH SIDDHARTHA S. , WANG JING , YANNIE PAUL J. , SANDHU YASHNOOR K. , GHOSH SHOBHA
Published: June 2019

IAP represents the first layer of the intestinal barrier and detoxifies bacterial endotoxin LPS in the gut lumen. Reduced levels of IAP are associated with diabetes and heart disease. We developed intestine specific IAP transgenic mice (IAPTg) and demonstrated attenuation of WD-induced intestinal barrier dysfunction and glucose intolerance. In this study, we crossed the IAPTg mice into LDLR-/- background to examine the effects on atherosclerosis. Panel A shows significant reduction in plasma total cholesterol (TC) and triglyceride (TG) in LDLR-/-IAPTg mice. There was a small but statistically non-significant improvement in glucose tolerance (Panel B). Enface analyses (Panel C) showed significant reduction in arch and total aortic lesions (Panel D). Expression of IAP was observed along the entire length of the GI tract including colon (Panel E). Expression of Muc-2, major protein of the mucin or the second layer of the intestinal barrier was enhanced in colon of IAPTg mice. Increased expression of GLP-1 was also noted in the ileum of IAPTg mice. These data suggest that in addition to limiting LPS-mediated intestinal inflammation, IAP also improves intestinal barrier function by increasing Muc-2 expression and IAP-modulated increase in ileal GLP-1 expression may contribute to the improved glucose tolerance.

Disclosure

S.S. Ghosh: None. J. Wang: None. P.J. Yannie: None. Y.K. Sandhu: None. S. Ghosh: None.

Funding

American Diabetes Association (1-16-IBS-105 to S.G.)
2008-P: BioChaperone Glucagon Exenatide (BC Glu Exe), a Stable Combination of Glucagon (Glu) and Exenatide (Exe) Achieved Larger Body Weight (BW) Loss than Exe Alone in DIO Mice
Authors: GAUDIER MARTIN , HAKIM SANA , MÉGRET CLAIRE , BEZAGU MARINE , FRANCOIS-HEUDE MARC , REGAIRAZ ANNE , MEIFFREN GRÉGORY , SOULA RÉMI , SOULA OLIVIER
Published: June 2019

Combination of excessive food intake and lack of physical activity is associated with an increased risk of obesity and associated morbidity. GLP-1 Receptor Agonists (GLP-1 RA) are one of the few treatment options currently available, but with limited weight loss. A combination of Human Glu and GLP-1 RA is expected to provide a superior BW reduction than GLP-1 RA alone. GLP-1 RA acts in the brain to induce satiety while Glu has a lipolytic and thermogenic effect in liver and adipose tissues. BioChaperone (BC) proprietary technology allows the solubilization and stabilization of poorly soluble and/or unstable peptides at neutral pH and thus the combination of Glu and GLP-1 RA. A combination formulation of Glu and Exe (BC Glu Exe) was developed. Such combination is physically and chemically stable for at least 4 weeks at 37°C in cartridges. It was tested in vivo against reference Exe and vehicle in diet induced obese (DIO) male mice. Mice were dosed with a subcutaneous continuous infusion of vehicle, Exe or BC Glu Exe via osmotic minipumps. After 14 days, Exe and BC Glu Exe induced a BW loss of 10% and 25% respectively, compared to the vehicle. The BW loss was significantly more pronounced with BC Glu Exe than with Exe.

In conclusion, these results support the testing of BC Glu Exe in clinics as a treatment for obesity.

Disclosure

M. Gaudier: Employee; Self; ADOCIA. Stock/Shareholder; Self; ADOCIA. S. Hakim: Employee; Self; ADOCIA. Stock/Shareholder; Self; ADOCIA. C. Mégret: Employee; Self; ADOCIA. M. Bezagu: None. M. Francois-Heude: Employee; Self; ADOCIA. Stock/Shareholder; Self; ADOCIA. A. Regairaz: Employee; Self; ADOCIA. Stock/Shareholder; Self; ADOCIA. G. Meiffren: Employee; Self; ADOCIA. Stock/Shareholder; Self; ADOCIA. R. Soula: Board Member; Self; Cellnovo. Employee; Self; ADOCIA. O. Soula: Board Member; Self; ADOCIA. Employee; Spouse/Partner; ADOCIA. Employee; Self; ADOCIA. Stock/Shareholder; Spouse/Partner; ADOCIA. Stock/Shareholder; Self; ADOCIA.
2010-P: Increasing POMC Positive Neurons and Ameliorating the Brain Inflammation Played an Important Role in DJB Improving Glucose Homeostasis in Diabetic Rats
Authors: WANG HUAI-JIE , JIANG BIN , LI JIAN , WANG WEI-YU , LI NA , YAN QINGTAO , GAO ZHIQIN , QU MEI-HUA
Published: June 2019

This study was focused on the effect of duodenal-jejunal bypass (DJB) on brain inflammation, activation brain insulin signaling and POMC positive neurons in type 2 diabetic (T2DM) rats. T2DM rats were induced by high-fat diet (HFD) and low dose streptozotocin (STZ) injection. Twelve T2DM rats were randomly divided into 2 groups, DJB group (T2DM-DJB, n=6) and T2DM group (T2DM-Sham, n=6). Six health Wistar rats were used as normal control rats (Wistar-Control, n=6). The results showed DJB group was significantly reduced the HOMA-IR and increased HOMA-ISI of T2DM rats 6 weeks after surgery. The Q-RT-PCR and Western-blot results showed DJB intervene significantly decreased the expression of inflammatory factors IL-6, TNF-α, IL-1β and NF-κB in the brain. Our data also showed that DJB activated the brain insulin by increasing the expression of insulin, IRS1 and IRS2 in the brain of T2DM rats. Immunohistochemical assay showed that DJB increased the number of POMC positive neurons in brain, and increased the expression of BDNF in neurons. Those results indicated that DJB might fulfill the antidiabetic effect by increasing POMC positive neurons and decreasing the brain inflammation in T2DM rats.

Disclosure

H. Wang: None. B. Jiang: None. J. Li: None. W. Wang: None. N. Li: None. Q. Yan: None. Z. Gao: None. M. Qu: None.

Funding

National Natural Science Foundation of China (81871892, 31671208, 81500798, 81471048); Shandong Province Natural Science Foundation (ZR2015HL128); Technology Development Plan of Weifang (2018YX027)
2013-P: Parkin Is Dispensable in Pancreatic Beta Cells and Adipocytes for Metabolic Homeostasis
Authors: PEARSON GEMMA , CORSA CALLIE , SOLEIMANPOUR SCOTT , MACDOUGALD ORMOND A.
Published: June 2019

The E3 ligase parkin is a critical regulator of mitophagy and has been identified as a susceptibility gene for type 2 diabetes (T2D), but its role in metabolically active tissues to modulate the development of T2D is unknown. Pancreatic β-cells and adipocytes both rely heavily on mitochondrial function to regulate optimal glycemic control to prevent T2D, but the role of parkin to modulate β-cell or adipocyte mitochondrial quality control is unclear. Despite the reported importance of parkin to control mitophagy, here we report that parkin surprisingly is dispensable in both β-cells and adipocytes for glucose homeostasis during diet-induced insulin resistance. We observe that insulin secretion, β-cell formation, and islet architecture were preserved in parkin deficient β-cells and islets, suggesting parkin is not necessary for control of β-cell function and islet compensation for diet-induced obesity. While transient parkin deficiency mildly impaired mitochondrial turnover in β-cell lines, parkin deletion in primary β-cells yielded no deficits in mitochondrial clearance. In adipocyte-specific deletion models, lipid uptake and β-oxidation were increased in cultured cells, while adipose tissue morphology, glucose homeostasis, or the beige-to-white adipocyte transition were unaffected in vivo. In key metabolic tissues where mitochondrial dysfunction is implicated in the development of T2D, our studies unexpectedly demonstrate that parkin is not an essential regulator of glucose tolerance, whole-body energy metabolism, or mitochondrial quality control. These findings highlight a novel role for parkin-independent processes to maintain β-cell and adipocyte mitochondrial quality control with diet-induced obesity.

Disclosure

G. Pearson: None. C. Corsa: None. S. Soleimanpour: None. O.A. MacDougald: None.

Funding

American Diabetes Association (1-18-PDF-064 to C.C.); National Institutes of Health; JDRF
2017-P: Gut Microbes after Bariatric Surgery in Humans Improve Glucose Control in Mice without Fat Loss
Authors: ANHÊ FERNANDO FORATO , FOLEY KEVIN P. , BARRA NICOLE G. , DUGGAN BRITTANY M. , CAVALLARI JOSEPH F. , HENRIKSBO BRANDYN D. , CANI PATRICE D. , BIERTHO LAURENT , TCHERNOF ANDRE , MARETTE ANDRE , SCHERTZER JONATHAN D.
Published: June 2019

Bariatric surgery (BS) is the most efficacious treatment against severe obesity and T2D. Among bariatric procedures, biliopancreatic diversion with duodenal switch (BPD-DS) can produce superior metabolic benefits compared with other surgical options. The mechanisms by which BPD-DS improve metabolic health are not well-understood, but there is evidence implicating the gut microbiota (GM) as contributor to changes in adiposity and consequently blood glucose control. We aimed to determine how the GM before and after BPD-DS alter host metabolism. Fecal samples from female patients subjected to BPD-DS were collected before (pre-surgery) and 12 months after surgery (post-surgery) and used to colonize female C57BL6NTac mice housed either in germ-free (GF) or SPF conditions. Oral glucose tolerance (OGT) was assessed in mice 3 and 7 weeks post-colonization. Three weeks after fecal microbiota transplantation (FMT), glucose tolerance was similar in GF mice receiving pre- and post-surgery fecal slurries. However, GF mice had lower glucose during OGT test 7 weeks after FMT derived from BPD-DS post-surgery compared to GF mice receiving pre-surgery fecal slurry. No changes in fat mass accretion were seen between pre- and post-surgery mice. SPF mice colonized with the fecal microbiota pre- and post-surgery showed no difference in glucose tolerance after 3 and 7 weeks of FMT. These data suggest that the GM after BPD-DS is an independent and transmissible contributor to improved host glucose control. Furthermore, while our data show that the mouse model (e.g., SPF vs. GF) dictates the glycemic response to FMT, exposure time (e.g., at least 7 weeks) is a key factor in microbe transmissible changes in glycemia.

Disclosure

F. Forato Anhê: None. K.P. Foley: None. N.G. Barra: None. B.M. Duggan: None. J.F. Cavallari: None. B.D. Henriksbo: None. P.D. Cani: Board Member; Self; A-Mansia Biotech. Consultant; Self; Biocodex, Pilèje, Valbiotis. Research Support; Self; Tate & Lyle. Stock/Shareholder; Self; A-Mansia Biotech, Enterosys. L. Biertho: None. A. Tchernof: Research Support; Self; Johnson & Johnson Medical Devices Companies, Medtronic, Pfizer Inc. A. Marette: Advisory Panel; Self; Plexus, Valbiotis. Consultant; Self; Danone Nutricia Research. J.D. Schertzer: None.

Funding

Canadian Institutes of Health Research; Diabetes Canada
2020-P: Comparable Disease Progression in GAN and AMLN Diet-Induced Obese Mouse Models of Biopsy-Confirmed Nonalcoholic Steatohepatitis
Authors: BOLAND BRANDON B. , HANSEN HENRIK H. , BOLAND MICHELLE , ORÓ DENISE , TØLBØL KIRSTINE SLOTH , VEIDAL SANNE , FEIGH MICHAEL , JELSING JACOB , VRANG NIELS , TREVASKIS JAMES
Published: June 2019

Amylin Liver NASH (AMLN) diet-induced obese C57Bl/6J (DIO-NASH) and ob/ob (ob/ob-NASH) mouse models display clinical translatability with respect to metabolic and histopathological changes associated with nonalcoholic steatohepatitis (NASH). A recent FDA ban on trans-fats in foods has necessitated the development of a new NASH diet capable of promoting comparable disease, as AMLN diet contains trans-fat-containing Primex shortening. Here, we assessed the disease phenotype in C57Bl/6J and ob/ob mice fed a high-fat diet with a nutrient composition and caloric content comparable to the AMLN diet. Male ob/ob mice were fed AMLN diet (40% total fat kcal of which 18.5% were trans-fat kcal; 20% fructose; 2% cholesterol) for 16 weeks or a modified AMLN diet with Primex substituted by palm oil, termed Gubra Amylin NASH (GAN) diet, for up to 30 weeks. C57 mice were fed GAN diet for 28 weeks. In ob/ob-NASH mice, GAN diet was more obesogenic and adipogenic than the AMLN diet. GAN, but not AMLN, diet also impaired glucose tolerance in ob/ob-NASH mice versus chow-fed C57Bl/6J mice. Both diets promoted similar levels of steatosis, lobular inflammation and hepatocyte ballooning as well as similar fibrotic liver lesions and collagen-1a1 fractional area. Mild (stage F1) and moderate (stage F2) grade fibrosis was induced in DIO-NASH and ob/ob-NASH mice, respectively, when fed either diet for 16 weeks. When fed GAN diet for ≥24 weeks, a significant proportion of ob/ob-NASH mice developed advanced fibrosis (stage F3). The two diets also promoted overlapping liver transcriptome changes.

In conclusion, AMLN diet modification by substitution of Primex with palm oil results in a preserved NASH phenotype in C57 and ob/ob mice. Accordingly, the GAN diet induced clear metabolic and histopathological hallmarks of biopsy-confirmed NASH in both DIO-NASH and ob/ob-NASH mice, highlighting the suitability of these models for the characterization of novel drug therapies for NASH.

Disclosure

B.B. Boland: Employee; Self; Gubra, MedImmune. H.H. Hansen: None. M. Boland: Employee; Self; Gubra, MedImmune. D. Oró: None. K.S. Tølbøl: None. S. Veidal: None. M. Feigh: None. J. Jelsing: Stock/Shareholder; Self; Gubra. N. Vrang: Board Member; Self; Gubra. Stock/Shareholder; Self; Gubra. J. Trevaskis: Employee; Self; Gilead Sciences, Inc., MedImmune. Stock/Shareholder; Self; AstraZeneca.
2021-P: STAT1 Represses Metabolic Intermediates Necessary to Store Fat
Authors: COX AARON , MASSCHELIN PETER , CHERNIS NATALIE , HARTIG SEAN M.
Published: June 2019

Obesity associates with chronic low-grade inflammation that likely impinges on the metabolic functions of adipocytes and may partially explain the insulin resistance that characterizes type 2 diabetes mellitus (T2DM). We recently demonstrated ectopic expression of the microRNA miR-30a in the subcutaneous fat pad of diabetic mice coupled improved insulin sensitivity and increased energy expenditure with decreased ectopic fat deposition in the liver and reduced WAT inflammation. Further, miR-30a directly inhibited STAT1, a major mediator of inflammatory signals such as interferon gamma (IFNγ). Despite the established dominance of STAT1 in the immune response and the importance of inflammation in the development of T2DM, the role of STAT1 in white adipocytes remains unknown. To this end, we sought to determine how STAT1 activity in white adipocytes affects insulin sensitivity. IFNγ treatment of human adipocytes diminished oxidative phosphorylation capacity, along with expression of mitochondrial proteins. STAT1 deletion in white adipocytes (STAT1 fKO) did not change body weight, but improved whole-body insulin sensitivity of diabetic mice. Transcriptome profiling by RNA-Seq suggested STAT1 fKO adipocytes engage GABPa and NFIA target genes that reflect oxidative phosphorylation specifically in the inguinal white adipose tissue (iWAT). Additional metabolomics profiling indicated the metabolic effects of STAT1 deletion in iWAT are associated with accelerated TCA cycle flux and aspartic acid generation, which provides intermediates to support lipid synthesis and histone modifications. These studies reveal important roles of inflammatory signals to suppress metabolism and epigenetic regulation in adipocytes that may underlie insulin resistance and T2DM.

Disclosure

A. Cox: None. P. Masschelin: None. N. Chernis: None. S.M. Hartig: None.

Funding

American Diabetes Association (1-18-IBS-105 to S.M.H.); National Institutes of Health (R01DK114356); Baylor College of Medicine (P30DK079638)
2031-P: Adipose-Specific Lack of Hexose-6-Phosphate Dehydrogenase Causes Inactivation of Adipose Glucocorticoids and Improves Metabolic Phenotype in Male Mice
Authors: WANG JIAN , WANG XINXIANG , LUTFY KABIRULLAH , FRIEDMAN THEODORE , JIANG MEISHENG , LIU YANJUN
Published: June 2019

Excessive glucocorticoids (GCs) production in adipose tissue promotes the development of visceral obesity and the metabolic syndrome. 11β-Hydroxysteroid dehydrogenase type 1 (11 β-HSD1) is critical for controlling intracellular GC production in adipose tissue, and this process is also regulated by hexose-6-phosphate dehydrogenase (H6PDH) that provides cofactor NADPH for 11β-HSD1 amplifying local GC production. To better understand the integrated molecular and physiological role of adipose H6PDH, we created a tissue specific knockout of H6PDH gene mouse model in adipocytes (H6PDHAcKO mice) and characterized the metabolic related phenotypes. H6PDHAcKO mice had decreased levels of intra-adipose corticosterone with reduction of 11β-HSD1 activity in response to H6PDH deletion in adipose tissue. Moreover, H6PDHAcKO mice also exhibited reduced fasting blood glucose levels and increased glucose tolerance with increased insulin sensitivity. In addition, plasma FFA levels were decreased with a concomitant decrease in the expression of lipase ATGL and HSL in the abdominal adipose tissue. These results indicate that inactivation of H6PDH expression in adipose tissue is sufficient to cause intra-adipose GC inactivation leading to the favorable pattern of metabolic phenotype. These data suggest that H6PDHAcKO mice may provide a good model for study the potential contributions of fat-specific H6PDH inhibition in the metabolic phenotype and other pathological disorders in vivo.

Disclosure

J. Wang: None. X. Wang: None. K. Lutfy: None. T. Friedman: None. M. Jiang: None. Y. Liu: None.

Funding

National Institute of Diabetes and Digestive and Kidney Diseases (SC1DK104821)
2036-P: Gut Microbes Regulate Insulin Clearance in Mice
Authors: FOLEY KEVIN P. , ZLITNI SOUMAYA , DUGGAN BRITTANY M. , HENRIKSBO BRANDYN D. , BARRA NICOLE G. , CAVALLARI JOSEPH F. , ANHÊ FERNANDO FORATO , LAU TREVOR , CHEN YUK KWAN , SCHERTZER JONATHAN D.
Published: June 2019

Obesity and insulin resistance are associated with hyperinsulinemia, which is caused by increased insulin secretion and/or reduced insulin clearance. Impaired insulin clearance may be caused by ectopic lipid deposition in liver and skeletal muscle, the key sites of insulin clearance and degradation. Insulin is the key hormone regulating blood glucose. The composition of the intestinal microbiota can regulate aspects of diet-induced obesity and glucose metabolism. Here we found that the microbiota also regulates insulin clearance during prolonged diet-induced obesity. Male C57Bl/6J mice fed 45% high fat diet (HFD) for a prolonged period had impaired insulin clearance relative to chow fed mice as measured by insulin/C-peptide ratio during an oral glucose tolerance test. High fat fed mice also showed impaired insulin clearance measured after injection of insulin - mice fed chow or 45% HFD had plasma insulin concentration measured at 0, 5, 30, and 60 minutes following injection of human insulin and area under the curve calculated. Treatment of 45% HFD-fed mice with an antibiotic cocktail of Neomycin/Ampicillin for 2 weeks improved insulin clearance after insulin injection. Next, we colonized previously germ-free mice with the microbiota from chow or 45% HFD-fed “donor” mice for 6 weeks. The previously germ-free “recipient” mice colonized with feces-resident microbes from chow or HFD fed donors did not differ in insulin clearance when recipient mice were fed a chow diet. However, when colonized recipient mice were switched from chow to 45% HFD for 2 weeks the recipient mice colonized with microbes from 45% HFD fed donors showed impaired insulin clearance relative to recipient mice colonized with microbes from chow fed donors. Our results demonstrate that diet-induced changes in fecal microbes are an independent factor regulating insulin clearance. Diet-induced changes in the gut microbiota and consequent impaired insulin clearance may participate in hyperinsulinemia leading to exacerbated insulin resistance and obesity.

Disclosure

K.P. Foley: None. S. Zlitni: None. B.M. Duggan: None. B.D. Henriksbo: None. N.G. Barra: None. J.F. Cavallari: None. F. Forato Anhê: None. T. Lau: None. Y. Chen: None. J.D. Schertzer: None.

Funding

Canadian Institutes of Health Research
2040-P: Sex-Dependent Effects of MC4R Genotype on HPA Axis Tone
Authors: CHAFFIN AKI T.B. , FANG YANBIN , LARSON KARLTON R. , MUL JORAM , RYAN KAREN K.
Published: June 2019

Neuroendocrine circuits underlying stress integration and systemic fuel homeostasis are substantially intertwined. Accordingly, metabolic diseases such as obesity and diabetes have a high incidence of co-morbidity with stress-associated psychological disorders like anxiety and depression. Importantly, there is a strong female bias in both metabolic and stress-related disorders, making the understanding of sex-specific functions of these pathways critical for treatment. The hypothalamic melanocortin system is a principal regulator of energy balance and also modulates HPA responses to acute stress. Mutations in the melanocortin-4 receptor (MC4R) is the most common monogenic cause of obesity in humans and has been associated with sex-dependent effects, such as more women than men exhibiting ‘emotional’ eating, a behavior that is thought to be stress-induced. Thus, we hypothesized that MC4R deficiency may cause sexually dimorphic metabolic and stress responses. We subjected male and female rats with a MC4R loss-of-function mutation to either chronic variable stress (CVS) or no stress for 31 days. Mid-study, all rats underwent an acute restraint stress challenge. Consistent with previous reports, male and female rats with MC4R deficiency had increased food intake and body weight, which were both decreased by CVS. Contrary to expectation, MC4R genotype did not affect HPA axis or metabolic responses to chronic stress. But importantly, we observed a significant interaction between MC4R genotype and sex in HPA axis tone and acute stress reactivity, such that MC4R deficiency blunted both endpoints in males but exaggerated them in females. Females showed a dramatic 259% and 419% increase in basal corticosterone and HPA reactivity, respectively, compared to males. The heightened stress reactivity of females with MC4R mutations suggests a possible mechanism for the sex-dependent effects associated with this mutation in humans and highlights how stress may differentially regulate metabolism in males and females.

Disclosure

A.T.B. Chaffin: None. Y. Fang: None. K.R. Larson: None. J. Mul: None. K.K. Ryan: None.

Funding

National Institutes of Health (R00HL111319)
2042-P: Genetic Dissection of Leptin Signaling in AgRP Neurons
Authors: XU JIE , CHIEN CHENG-HAO , YI XINCHI , BARTOLOME CHRISTOPHER , KONG DONG
Published: June 2019

Leptin, a hormone produced in white adipose tissue, acts in the brain to maintain body weight and blood glucose stability. Dysregulation of leptin or its receptor (LEPR) results in severe obesity and diabetes. Although intensive studies on leptin have transformed obesity and diabetes research, clinical applications of the molecule are still limited, at least in part owing to the complexity and our incomplete understanding of the underlying neural circuits. In our previous findings, we found that the hypothalamic AgRP(agouti-related peptide) neurons are the primary target for leptin to regulate both energy balance and glucose homeostasis. We show that CRISPR-mediated deletion of leptin receptor in AgRP neurons causes severe obesity and diabetes. We also uncover divergent mechanisms of acute and chronic inhibition of AgRP neurons by leptin (presynaptic potentiation of GABA (γ-aminobutyric acid) neurotransmission and postsynaptic activation of ATP-sensitive potassium channels (Katp), respectively). However, the molecular signaling involved in leptin's regulation on Katp and GABA transmission are not clear. In current study, we employed the CRISPR technology, combined with electrophysiology to further identify that the Phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) pathway plays an important role in mediating leptin's action on GABA transmission. We also tested that leptin can directly activate KATP channel and by using two-photon excitation microscopy, we proved that this activation is modulated by ATP/ADP ratio.

Disclosure

J. Xu: None. C. Chien: None. X. Yi: None. C. Bartolome: None. D. Kong: Board Member; Spouse/Partner; Jersey Biosciences Inc. Board Member; Self; PRECIDIAG INC.

Funding

American Diabetes Association (1-19-PDF-159-R to J.X.)
2058-P: Leptin and Adiponectin Concentrations Independently Predict Future Accumulation of Visceral Adiposity in Nondiabetic Japanese Americans
Authors: SONG SUN OK , KAHN STEVEN E. , LEONETTI DONNA L. , FUJIMOTO WILFRED Y. , BOYKO EDWARD J.
Published: June 2019

Objectives: The adipokines leptin and adiponectin are associated with change in body composition and are highly correlated, raising questions about whether they exert independent effects. We investigated whether these two adipokines are independently associated with regional body fat accumulation in a prospective study of Japanese Americans.

Methods: Nondiabetic participants between the ages of 34 to 74 years were followed for 5 years to assess change in body composition. Leptin and adiponectin concentrations and single slice CT-measurements of intra-abdominal fat (IAF), abdominal (SCF) and thigh (TF) subcutaneous fat cross-sectional areas were evaluated at baseline and 5 year follow-up study visits. Multiple linear regression analysis was used to estimate the association between leptin and adiponectin and future 5-year accumulation of IAF.

Results: 96 men and 95 women without diabetes included in this analysis had the following baseline mean (SD) values: age 45.7 (3.5) years and 46.4 (3.9) years; BMI 25.5 (3.1) kg/m2 and 24.0 (3.9) kg/m2; IAF 78.7 (38.6) cm2 and 62.1 (39.0) cm2; leptin concentration 4.5 (2.3) μg/L and 10.2 (5.2) μg/L; and adiponectin concentration 7.4 (3.2) μg/mL and 10.8 (4.7) μg/mL, respectively. Baseline leptin (β = 1.7722, p=0.014) and adiponectin concentrations (β = -0.4162, p<0.001) were significantly associated with ΔIAF over 5 years in multivariable models adjusting for age, sex, diabetes family history, weight change over 5 years, and baseline measurements of BMI, IAF, abdominal SCF, abdominal circumference, TF, and HOMA-IR.

Conclusions: In nondiabetic Japanese Americans, baseline concentrations of leptin and adiponectin were independent predictors of IAF accumulation at 5 years. Higher levels of leptin and adiponectin were associated with greater and lesser accumulation of IAF, respectively. These relationships were independent of age, sex, insulin sensitivity, and body composition.

Disclosure

S. Song: None. S.E. Kahn: Advisory Panel; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Eli Lilly and Company, Intarcia Therapeutics, Inc., Janssen Pharmaceuticals, Inc., Merck & Co., Inc., Novo Nordisk A/S. Consultant; Self; Neurimmune. Other Relationship; Self; Boehringer Ingelheim Pharmaceuticals, Inc., Merck & Co., Inc., Novo Nordisk A/S. D.L. Leonetti: None. W.Y. Fujimoto: None. E.J. Boyko: None.

Funding

National Institutes of Health DK31170, HL49293); University of Washington (DK017047, DK035816, RR-000037); VA Puget Sound Health Care System (to E.J.B., S.E.K.)