bluuebunny/crossref_metadata_2025 huggingface dataset:
200-OR: IER3IP1 Is Critical for Maintaining Glucose Homeostasis through Regulating the Endoplasmic Reticulum Function and Survival of ß-Cells
Authors: YANG JING , ZHEN JINYANG , FENG WENLI , FAN ZHENQIAN , HUANG YUMENG , SHU HUA , LI XIN , QIAO JINGTING , FAN YUXIN , SUN JINHONG , LI NA , LIU TENGLI , WANG SHUSEN , ZHANG XIAONA , ARVAN PETER , LIU MING
Published: May 2022

Recessive mutations in IER3IP1 (Immediate Early Response 3 Interacting Protein 1) cause a triad of microcephaly, epilepsy, and permanent neonatal diabetes syndrome (MEDS) . IER3IP1 encodes an endoplasmic reticulum (ER) membrane protein, which is crucial for brain development, however the role of IER3IP1 in β cell function and glucose homeostasis remains unknown. Herein, we established a new β cell-specific IER3IP1 knockout (IER3IP1-βKO) mouse model and found that IER3IP1 deficiency in β cells causes severe early onset insulin deficient diabetes. Functional studies revealed a markedly dilated ER along with significantly increased proinsulin misfolding and elevated expression of the ER chaperones including PDI, ERO1, BiP, and P58IPK. Transcriptome analysis confirmed by qRT-PCR revealed a markedly decreased expression of genes associated with β cell maturation, cell cycle, and anti-apoptosis, whereas there was a significantly increased expression of anti-proliferation genes. Indeed, multiple independent approaches further demonstrated that IER3IP1-βKO impaired β cell maturation and proliferation, and promoted cell death. These data not only uncover a critical role of IER3IP1 in normal β cell function and survival, but they also provide insight into the mechanism (s) by which loss-of-function mutations of IER3IP1 lead to diabetes.

Disclosure

J.Yang: None. J.Sun: None. N.Li: None. T.Liu: None. S.Wang: None. X.Zhang: None. P.Arvan: n/a. M.Liu: None. J.Zhen: None. W.Feng: None. Z.Fan: None. Y.Huang: None. H.Shu: None. X.Li: None. J.Qiao: None. Y.Fan: None.

Funding

National Natural Science Foundation of China (81830025, 81620108004, 81870533, 81900720, 81800733, 82100865, 82070805, and 81870535)
202-LB: Insulin Regulation of Lipolysis in Adipocytes
Authors: STOECKLI JACQUELINE , ZADOORIAN ARMELLA , YANG GUANG , JAMES DAVID E.
Published: May 2022

Adipocyte lipolysis is tightly regulated to provide fatty acids when needed and this is suppressed postprandially by insulin. This regulation remains incompletely understood. We have identified the abhydrolase ABHD15 as a key player in this process together with the phosphodiesterase PDE3B. In the absence of either ABHD15 or PDE3B, insulin is not able to suppress lipolysis. ABHD15 and PDE3B form a complex and in response to insulin they are both phosphorylated by Akt and bind to the adaptor protein 14-3-3. Insertion of a constitutive 14-3-3 binding site into either ABHD15 or PDE3B results in complete suppression of lipolysis even under pro-lipolytic conditions. Notably, we have discovered that the kinase Akt interacts with ABHD15 and insulin and/or 14-3-3 binding to ABHD15 abolishes the interaction. In summary we propose a model where ABHD15 binds to and suppresses the phosphodiesterase activity of PDE3B in the absence of insulin thereby facilitating unrestrained lipolysis and supply of fatty acids during starvation or crisis. Akt directly interacts with the ABHD15/PDE3B complex leading to phosphorylation and 14-3-3 binding upon insulin stimulation, which activates a pool of PDE3B thus repressing PKA and the lipolytic drive.

Disclosure

J. Stoeckli: Research Support; Pfizer Inc. A. Zadoorian: None. G. Yang: None. D. E. James: Research Support; Eli Lilly and Company, Novo Nordisk, Pfizer Inc.

Funding

Pfizer Inc.
206-LB: Increase of Hexokinase-2 Protein without Increase of Other Glycolytic Enzymes in Myotubes with High Glucose Concentration Supports the Hypothesis of Hexokinase-2-Linked Unscheduled Glycolysis as a Driver of Insulin Resistance
Authors: XUE MINGZHAN , RABBANI NAILA , THORNALLEY PAUL
Published: May 2022

Insulin resistance in skeletal muscle is the major metabolic defect leading to the development of type 2 diabetes. The initiating dysfunction driving development of insulin resistance has not been disclosed. Recently, stabilization of hexokinase-2 (HK2) to proteolysis by increased glucose concentration, increasing flux through early-stage glycolysis without increase in expression and activity of other glycolytic enzymes, was identified as the initiator of metabolic dysfunction in hyperglycemia. This creates a wave of increased glycolytic intermediates activating hexosamine and protein kinase C pathways and increasing formation of methylglyoxal. Increased glucose-6-phosphate displaces HK2 from mitochondria, producing mitochondrial hyperpolarization and dysfunction. This is termed HK2-linked unscheduled glycolysis. Skeletal muscle exposed to increased fasting plasma glucose may stimulate this. To test this, we studied glycolytic enzyme abundance in murine C2C12 myotubes incubated with 5.5 and 25 mM glucose for 5 days, determining HK2 protein changes by Western blotting, normalized to ß-actin. Protein abundances in C2C12 myotube cultures with 5.5, 11.1 and 25.0 mM glucose determined by label-free quantitative mass spectrometry proteomics were mined from published data. In C2C12 myotubes, HK2 protein increased 46 ± 5 % in 25 mM glucose (P<0.001, n = 3; Western blotting) . Proteomics corroborated this with 1.5 and 1.8 fold increase of HK2 in 11.1 and 25.0 mM glucose cultures, compared to 5.5. mM glucose control (P<0.01, n = 3) . Abundances of other glycolytic enzymes, hexokinase-1, glucose-6-phosphate isomerase, phosphofructokinase, aldolase, triosephosphate isomerase and glyceraldehyde-3-phosphate dehydrogenase, were unchanged. This establishes the conditions for HK2-linked glycolytic overload. We conclude that high glucose concentration in C2C12 myotubes in vitro exhibits conditions producing hexokinase-2-linked unscheduled glycolysis

Disclosure

M. Xue: None. N. Rabbani: None. P. Thornalley: None.

Funding

Qatar Foundation, QB14Qatar University, QUHI-CMED-21_22-1
206-OR: Insulin Gene Mutation in Family with Monogenic Diabetes Leads to Smaller Pancreas
Authors: WRIGHT JORDAN J. , WILLIAMS JONATHAN M. , GREELEY SIRI ATMA W. , POWERS ALVIN C. , VIROSTKO JOHN , MOORE DANIEL J.
Published: May 2022

Individuals with new-onset type 1 diabetes (T1D) and those at risk for T1D have a smaller pancreas. The reason for the reduced pancreas size and acinar cell number in T1D is not known, with possible explanations being a direct effect of insulin deficiency, acinar cell-directed autoimmunity, or cytokine-mediated inflammation. To test the hypothesis that insulin deficiency leads to reduced pancreas size, we measured pancreas volume in a family with monogenic diabetes due to an INS-gene mutation using a standardized MRI protocol developed as part of the Multicenter Assessment of the Pancreas in Type 1 Diabetes program (MAP-T1D, www.map-t1d.com, PMID: 34428220) . Pancreas volume was normalized to body weight to calculate pancreas volume index (PVI) . The family, carrying a heterozygous c.94G>C (p.Gly32Arg) INS mutation, was identified as part of the Monogenic Diabetes Registry at the University of Chicago. All family members with diabetes, including the father, diagnosed at age 22, and three children, diagnosed before 8 months, have clinical insulin deficiency and are treated with insulin. All four family members with diabetes (age 30, 30, 34, and 62 yrs; BMI 23-28; PVI 0.23, 0.42, 0.53, and 0.48 mL/kg) had small PVI compared to those without diabetes (age 32, 38, and 60 yrs; BMI 19-23; PVI 1.07, 1.17, and 0.92, p<0.01) . The pancreas of family members with diabetes was similar to those seen in individuals with new-onset T1D (age 13.4 ± 4.1 years, BMI 20.5 ± 4.1, PVI 0.68 ± 0.22) , and pancreas of family members without diabetes was similar to those of unrelated controls (age 15.9 ± 6.7 years, BMI 21.4 ± 4.4, PVI 0.97 ± 0.22 ml/kg; PMID: 30552135) . Studies in this family indicate that insulin is a determinant of pancreas size either directly as a trophic factor or indirectly through control of other islet-derived growth factors. This relationship suggests that reduced pancreas volume in T1D may be an earlier indicator of local insulin loss rather than a reflection of immune or inflammatory factors.

Disclosure

J.J.Wright: None. J.M.Williams: None. S.W.Greeley: None. A.C.Powers: None. J.Virostko: None. D.J.Moore: None.
21-LB: Transdermal Microneedle Device Delivery of Adipocyte-Specific AAVs to Overexpress Adipose Tissue Neurotrophic Factors in the Treatment of Diabetic Peripheral Neuropathy
Authors: BLASZKIEWICZ MAGDALENA , TOWNSEND KRISTY L.
Published: May 2022

Diabetes is the leading cause of peripheral neuropathy (PN) , which results in loss of nerve supply in tissues like skin, adipose and muscle. While there are currently few treatments for PN, early mitigation in the pre-diabetic state with tissue neurotrophic factors may improve nerve function in metabolically important tissues like adipose. We used an adipocyte-tropic adeno-associated virus (AAV; serotype Rec2) to deliver neurotrophic factors directly to scWAT using a transdermal microneedle device that we developed. This approach avoids potential off-target effects and aberrant axon outgrowth in skin that may increase pain. Using both the BTBRob/ob and C57BL/6J diet-induced neuropathy mouse models, we have demonstrated that AAVRec2-BDNF (brain derived neurotrophic factor, which we have implicated in controlling adipose innervation) delivery to scWAT with our device increased tissue innervation 14 days after treatment, marked by increased protein expression of pan-neuronal marker PGP9.5 and sympathetic nerve marker tyrosine hydroxylase (TH) . Longer periods of dietary obesity (25+ wks vs 16 wks) blunted the ability of AAVRec2-BDNF to increase innervation in scWAT, despite these mice showing an initial decrease in body weight compared to controls. This indicates there may be a critical window for therapy delivery during the progression to diabetic neuropathy during which interventions are more advantageous. Treatment with AAVRec2-NGF (nerve growth factor) also increased scWAT innervation in obese mice at 8 weeks post-treatment, as evidenced by increased protein expression of PGP9.5, TH and markers of axon outgrowth (Gap43, Vasp) . Thermal imaging above inguinal scWAT revealed an increase in temperature only in AAVRec2-NGF treated mice, supporting the idea that NGF-responsive nerves drive tissue browning and/or thermogenesis. Taken together, we have developed a novel treatment approach for delivering adipocyte-tropic AAVs to overexpress neurotrophic factors as a means to mitigate diabetes-associated PN.

Disclosure

M. Blaszkiewicz: None. K. L. Townsend: Other Relationship; Neuright, Inc.
214-OR: Effects of Polyphenols on Cholesterol Efflux and Insulin Secretion in MIN6 Cells
Authors: MATSUKI KOTA , KIMURA YUKI , MATSUMURA KOKI , TANABE JUTARO , MURAKAMI HIROSHI , DAIMON MAKOTO
Published: May 2022

Background: Diabetic dyslipidemia is characterized by elevated levels of triglyceride-rich lipoproteins and reduced levels of HDL-cholesterol (HDL-C) . Low levels of HDL-C are associated with an increased risk of atherosclerotic cardiovascular disease, because HDL protects against atherosclerosis through multiple mechanisms include removal of excess cholesterol from macrophages. HDL can also influence cholesterol homeostasis in pancreatic β-cell. It is noteworthy that absence of ATP-binding cassette transporter A1 (ABCA1) , which is a cellular cholesterol transporter and regulates islet cholesterol efflux, results in islet cholesterol overload and impaired insulin release in mice. We examined the associations of cholesterol efflux and insulin secretion in MIN6 cells with polyphenols that is reported to increase cholesterol efflux.

Methods: Murine MIN6 cells were labeled with 3H-cholesterol and incubated with ApoA1 (μg/ml) or HDL (25 μg/ml) for 24 hours. The percentage cholesterol efflux was calculated by dividing the media-derived radioactivity by the sum of the radioactivity in the media and the cells. The effect of polyphenols on the cholesterol efflux was studied, adding that into the medium before the analysis of the cholesterol efflux. Insulin secretion was assessed by ELISA as the concentration of insulin in the culture medium. The mRNA expression of ABCA1 and ABCG1 were determined by real-time Quantitative RT-PCR.

Results: Under the existence of polyphenols (isorhamnetin) , the ApoA1 or HDL-mediated cholesterol efflux had significantly increased by 1.4% or 1.8%, respectively (n=4, p<0.01) . Isorhamnetin had increased insulin secretion by 882 ng/mg protein/h (n=3, p<0.05) and significantly decreased ABCA1 and ABCG1 expressions.

Conclusion: These data suggest that isorhamnetin increases cholesterol efflux and insulin secretion in MIN6 cells. Isorhamnetin could be the interesting candidate to investigate the new treatment for patients with diabetes mellitus.

Disclosure

K.Matsuki: None. Y.Kimura: None. K.Matsumura: None. J.Tanabe: None. H.Murakami: None. M.Daimon: None.

Funding

JSPS KAKENHI Grant Number 20K11549
222-OR: Effectiveness, Safety, and Treatment Adherence of Follow-On Insulin in Diabetes Management
Authors: CHEN XIAOXUE , PHAM TIMOTHY , BARRON JOHN J. , HART RICHARD A. , ABARCA JACOB , DEVRIES ANDREA
Published: May 2022

Background: The high insulin costs have associated with underuse and poor adherence among patients with types 2 diabetes (T2D) . Basaglar was approved by FDA in 2015 as a follow-on insulin to reference insulin Lantus. It presents an opportunity to reduce costs and improve adherence to insulin treatment. The study assessed the change in HbA1c after initiation of follow-on insulin (Basaglar) or reference insulin (Lantus) among patients with T2D. We also compared treatment adherence, safety events, and costs at 1-year after initiation of insulin.

Methods: Using claims data from a large U.S. health plan during 2016-2020, we identified adults with T2D who initiated either Basaglar or Lantus. Generalized linear regression modeling assessed the differences in outcomes between the groups. A 0.4% margin was used to determine non-inferiority for HbA1c .

Results: The study included 1,136 Basaglar users and 6,3Lantus users. The mean age was 54.0 years in Basaglar users and 56.3 years in Lantus users (p<0.001) . Both groups showed more than 1% reduction in HbA1c over 6 months and over 12 months. Reduction in HbA1c with Basalgar was similar (noninferior) to that with Lantus, with an adjusted difference of Basaglar to Lantus of 0.14% (95% CI -0.02 to 0.30, p=0.084) over 6 months and 0.17% (95% CI 0.02 to 0.32, p=0.024) over 12 months. Rates of adverse events were similar for both hypoglycemia and vascular events. The Basaglar group showed higher adherence in terms of proportion of days covered (adjusted difference 0.06, 95% CI 0.to 0.08, p<0.001) . Medical costs were similar, but the cost of Basaglar was lower (adjusted mean cost difference -$462, 95% CI -$556 to -$363, p<0.001) after adjustment.

Conclusions: Basaglar provided similar glycemic control compared to Lantus, had similar safety profile and more favorable adherence in patients with T2D. The findings highlight the potential that biosimilar/follow-on biologics offer in terms of expanding patient access and improving treatment affordability.

Disclosure

X.Chen: None. T.Pham: Employee; Anthem, Inc. J.J.Barron: None. R.A.Hart: None. J.Abarca: None. A.Devries: None.
223-OR: ADA Presidents' Select Abstract: Novel Ligand and Kinase-Independent Signaling by the Insulin Receptor
Authors: NAGAO HIROFUMI , CAI WEIKANG , PAN HUI , BATISTA THIAGO M. , BRANDAO BRUNA , KAHN C. RONALD
Published: May 2022

Insulin acts through the insulin receptor (IR) tyrosine kinase and two major canonical post-receptor signaling pathways (the IRS-1/PI3K/Akt pathway and the Shc/Ras/MAP kinase pathway) to exert its classic metabolic and mitogenic actions. To create a detailed map of how different domains of the receptor might be linked to different insulin actions, we created cells in which endogenous IR and IGF1R had been genetically inactivated, after which the cells were reconstituted with either the wild-type IR, a kinase-dead mutant of IR (K1030R-IR) , a truncated IR lacking just the C-terminus of IR (∆CT-IR) and a truncated IR with the juxtamembrane domain only inside the cell (JMO-IR) . Using these cells and a multi-omics approach, we have uncovered a second novel IR signaling pathway that is dependent on the intracellular domain of IR but is ligand and tyrosinekinase-independent (LYK-I for short) . We find that the LYK-I actions of the IR are mediated by changes in a phosphorylation of a network of proteins involved in cell cycle/mitosis, ATM signaling, extracellular matrix organization, and cellular senescence. These actions result in upregulation of expression of multiple extracellular matrix-related genes and proteins, and down-regulation of immune/interferon-related and cellular senescence related genes and proteins. Functionally, LYK-I signaling results in increased cell proliferation and increased sensitivity to apoptosis. Thus, in addition to classical ligand and tyrosine kinase-dependent signaling, the IR regulates a second, novel ligand and tyrosine kinase-independent (LYK-I) pathway which regulates the cellular machinery involved in cellular senescence, extracellular matrix interaction and apoptotic sensitivity.

Disclosure

H.Nagao: None. W.Cai: None. H.Pan: n/a. T.M.Batista: None. B.Brandao: n/a. C.Kahn: Advisory Panel; Kaleido, Consultant; Cellarity, Flagship Pioneering, Sana Biotechnology Inc.
227-LB: Elevated Plasma Lactate and the Risk for Metabolic Syndrome—Is Skeletal Muscle a Producer or Consumer?
Authors: BROSKEY NICHOLAS T. , JONES TERRY E. , TANNER CHUCK J. , ZHENG DONGHAI , JEVTOVIC FILIP , KRASSOVSKAIA POLINA , MATARESE LAURA E. , CORTRIGHT RONALD N. , HICKNER ROBERT , DEMARIA ERIC J. , PORIES WALTER J. , HOUMARD JOSEPH A. , DOHM LYNIS
Published: May 2022

Background: The incidence of metabolic diseases is rising and there is a dire need for early detection to implement prevention. Fasting plasma lactate concentrations have been shown to be elevated in individuals with obesity and predictive of type 2 diabetes. An elevated fasting lactate concentration could possibly be the product of a reduction in muscle oxidative capacity and increased muscle lactate output. However, it is unknown how early this is evident, as are the mechanisms involved. Aim: The aim of this study was to determine if fasting lactate concentrations were linked with a reduction in skeletal muscle oxidative capacity in a cohort without metabolic disease.

Methods: Young (age 28 ± 7; N=21) overweight (BMI (27.1 ± 0.4 kg/m2) men (n=12) and women (n=9) were recruited for this study. Blood biomarkers were measured in the fasted state and body composition was determined by DXA. Muscle oxidative capacity was measured in skeletal muscle homogenates (vastus lateralis biopsy) using 14C-labeled labeled palmitate and pyruvate. Muscle lactate output was determined by microdialysis during a hyperinsulinemic euglycemic clamp procedure.

Results: Elevated lactate was associated with elevated visceral adiposity (R2=.40, p=.003) , elevated triglycerides (R2=.56, p=.0001) , as well as elevations in systolic blood pressure (R2=.39, p=.003) . Subjects with higher lactate had lower ratio of fatty acid oxidation to pyruvate oxidation (ratio R2=.49, p=.002) . Muscle lactate uptake in the basal state of the clamp positively associated with plasma lactate (R2=.92, p=<.0001) ; however, in the insulin phase net lactate output was near zero.

Conclusion: Individuals who are overweight but otherwise healthy have elevated plasma lactate that associates with parameters of the metabolic syndrome. Lactate was associated with a shift from lipid to carbohydrate oxidation. Muscle is a consumer of lactate in the fasted state, whereas adipose tissue may be the source of production postprandially.

Disclosure

N. T. Broskey: None. E. J. Demaria: None. W. J. Pories: None. J. A. Houmard: None. L. Dohm: None. T. E. Jones: None. C. J. Tanner: None. D. Zheng: None. F. Jevtovic: None. P. Krassovskaia: None. L. E. Matarese: None. R. N. Cortright: None. R. Hickner: None.

Funding

NIH (R01DK120296)
23-OR: Loss of the Transcription Factor Tcf21 in Adult Podocytes Leads to Susceptibility in Diabetic Kidney Disease
Authors: TERAMOTO NAOYA , MAEZAWA YOSHIRO , MINAMIZUKA TAKUYA , KOSHIZAKA MASAYA , YOKOTE KOUTARO
Published: May 2022

Background: Diabetic kidney disease (DKD) is the most common cause of dialysis induction in the United States. Tcf21 is a basic helix-loop-helix transcription factor that is essential for the development of the lungs, heart, and kidneys. Previously, we reported that Tcf21 regulates podocyte development. However, the precise role of Tcf21 in mature individuals and DKD remains unclear.

Method: We generated mice that lacked Tcf21 only in podocytes after birth (iKO) using a doxycycline induction system. We also constructed a diabetes mouse model using streptozotocin injections. In addition, we used cultured human podocytes to investigate the effects of Tcf21 overexpression and the factors that regulate Tcf21 expression.

Results: When the Tcf21 gene was deleted specifically in podocytes in 3-week-old mice, urinary protein was not observed. In contrast, when diabetes was induced in these mice, massive urinary protein and strong glomerulosclerosis was present in 60% of iKO mice. Ultrastructural analysis revealed glomerular basement membrane thickening and podocyte foot process effacement, suggesting that iKO mice are susceptible to DKD. In addition, RNA-seq analysis of Tcf21-overexpressing podocytes showed accumulation of genes involved in the interferon pathway, extracellular matrix production, senescence, and autophagy in gene ontology analysis. Analysis of individual genes showed upregulation of interferon-related genes such as IFI6 and IFI27, increased expression of PAI-1, which is one of the senescence-associated secreted phenotypes, and decreased expression of HMGA2, whose SNIP is known to correlate with susceptibility to DKD. In addition, Tcf21 expression was suppressed by 58% and 27% after TGF-β and high glucose plus insulin stimulation, respectively.

Conclusion: Our results suggest that Tcf21 protects against DKD in mature individuals. Elucidation of the mechanism by which Tcf21 prevents DKD may lead to the identification of novel therapeutic targets.

Disclosure

N.Teramoto: None. Y.Maezawa: None. T.Minamizuka: None. M.Koshizaka: None. K.Yokote: None.
230-LB: Amino Acid–Induced Glucagon Secretion and Glucagon Enhancement of Amino Acid Catabolism Is Independent of Glucose
Authors: MARUSZCZAK KATHARINA , RASMUSSEN CHRISTINE , CEUTZ FREDERIK R. , ØRGAARD ANNE , CHRISTENSEN EMILIE E. , RICHTER MICHAEL M. , HOLST JENS J. , WINTHER-SOERENSEN MARIE , WEWER ALBRECHTSEN NICOLAI J.
Published: May 2022

Amino acids (aa) stimulate the secretion of glucagon (gcg) and gcg receptor signaling controls aa catabolism, constituting the liver-alpha cell axis. Impairment of the liver-alpha cell axis is observed in diabetes, but how glucose (glc) levels affect this axis is unknown. We investigated the role of glc on the liver-alpha cell axis by 1) isolated perfused pancreas, 2) isolated perfused liver, and 3) a randomized in-vivo study in male mice. The isolated perfused pancreas was used to evaluate the direct effect of low (3.5mM) and high (15mM) glc levels, respectively on aa (10mM arginine) -induced gcg secretion. High glc levels significantly lowered basal gcg secretion, but aa-induced gcg responses were comparable to those at low glc levels (p=0.38) . The direct effect of glc on gcg induced ureagenesis was assessed by isolated single pass perfused liver stimulated with 10mM mixture of 18 aa + 10nM gcg for two periods of 15 min with glc infused at either 1 or 18 mmol/L. The order of glc addition was randomized. Aa and gcg significantly increased urea production compared to baseline, and this was independent of low or high glc levels (p=0.95) . Whole-body effects of glc on the liver-alpha cell axis were assessed in-vivo including four groups receiving an intraperitoneal injection of either Glc-Saline (2 g/kg, Glc/S, n=8) , Glc-Aa (2 g/kg, + 14 g/l, respectively Glc/Aa, n=10) , Saline-Aa (S/Aa, n=10) and saline-saline (volume-matched, S/S, n=10) . Blood samples were obtained at 0,2,4,10 and 20 minutes and levels of glc, gcg, insulin (ins) , and aa were measured. Glc levels did not differ significantly between Glc/S and Glc/Aa groups, but ins and gcg were significantly higher in the G/Aa group. The gcg:ins ratio did not differ between groups. Plasma levels of gcg and aa were not significantly different between the G/Aa and S/Aa groups (p=0.28) . These results suggest that aa overrule the inhibitory effect of glc on gcg secretion and the actions of glucagon on aa catabolism may be independent of glc in mice.

Disclosure

K. Maruszczak: None. C. Rasmussen: None. F. R. Ceutz: None. A. Ørgaard: Employee; Novo Nordisk A/S. E. E. Christensen: None. M. M. Richter: None. J. J. Holst: Advisory Panel; Novo Nordisk, Board Member; Antag Therapeutics, Bainan Biotech. M. Winther-soerensen: None. N. J. Wewer albrechtsen: Research Support; Mercodia AB, Novo Nordisk, Regeneron Pharmaceuticals Inc., Speaker's Bureau; Merck & Co., Inc., Mercodia AB.

Funding

NNF Excellence Emerging Investigator Grant ? Endocrinology and Metabolism (Application No. NNF19OC0055001) , EFSD Future Leader Award (NNF21SA0072746) and Independent Research Fund Denmark Sapere Aude Program (1052-00003B) .
235-LB: YH34160, a Novel Long-Acting GDF15 Fusion Protein, Exerts Potent and Sustained Body Weight Loss in Rodent Obesity Models
Authors: LIM SEYOUNG , KIM DO-HOON , YANG JIEUN , KYEONG JU MI , KIM SUKYUNG , RA SIM BO , KIM JUNHWAN , OH SE-WOONG
Published: May 2022

Growth differentiation factor 15 (GDF15) is a multifunctional protein associated with energy homeostasis and body weight regulation. GDF15 has emerged as an attractive therapeutic target to treat obesity-related metabolic disorders. GDF15 reduces food intake with a unique mode of action via its receptor GDNF family receptor α-like (GFRAL) and the co-receptor RET. YH34160 is an engineered GDF15 variant-Fc fusion protein to have extended half-life and potent functional activity by enhancing binding affinity to GDF15 receptors (GFRAL/RET) . Based on rodent and monkey pharmacokinetic (PK) data, YH34160 is expected to have an optimal PK profile for once-weekly dosing in humans. In efficacy studies using obese mouse models, YH34160 demonstrated a potent and sustained weight-lowering effect. After a single subcutaneous injection in diet-induced obese (DIO) mice, YH34160-treated groups showed sustained and dose-dependent body weight (BW) reduction compared to long-acting glucagon like peptide-1 receptor agonist (GLP-1RA) . Following a 6-week multiple-dose study in DIO mice, YH34160-treated groups exhibited a greater and more prolonged BW loss compared to the group of GLP-1RA. Marked BW reduction and improved lipid profile by YH34160 were also proved in leptin-deficient (ob/ob) mice compared to GLP-1RA. In addition, YH34160 caused significantly better anti-obesity effects, and a much more improved metabolic profile than that of albumin-GDF15, and dual GLP-1/Glucagon receptor agonist. Interestingly, YH34160 in combination with GLP-1RA or dual GLP-1/glucose-dependent insulinotropic polypeptide receptor agonist (GIPRA) achieved more potent and greater BW loss compared to each mono-treated group. Overall, these findings indicate that YH34160 would be a promising therapeutic candidate, as well as in combination with GLP-1-based therapeutics, for the treatment of obesity and obesity-related comorbidities.

Disclosure

S. Lim: None. D. Kim: None. J. Yang: None. M. Ju: None. S. Kim: None. B. Sim: None. J. Kim: None. S. Oh: Employee; Yuhan, Stock/Shareholder; Yuhan.
237-OR: Platelet-Derived Protein Responses Differ According to Severity of Hypoglycemia
Authors: MOIN ABU , KAHAL HASSAN , AL-QAISSI AHMED , SATHYAPALAN THOZHUKAT , ATKIN STEPHEN , BUTLER ALEXANDRA E.
Published: May 2022

Introduction: Severe hypoglycemia is associated with an increased risk of cardiovascular (CV) death, and platelet responses to hypoglycemia (hypo) have been described. The impact of a transient severe hypo versus prolonged less severe hypo is unclear.

Methods: 2 hypo studies were compared; firstly, in 18 subjects (type 2 diabetes (T2D) : 8 controls) blood glucose lowered to 3.5mmoL/L (90mg/dL) for 1-hour; secondly, in 46 subjects (23 T2D: 23 controls) blood glucose lowered to <2.2mmoL/L (<40mg/dL) transiently. The platelet-related protein (PRP) responses from baseline to after 1-hour of hypo (study-1) or at severe transient hypo (study-2) were compared, and at 24-hours post-hypo. Slow Off-rate Modified Aptamer (SOMA) -scan plasma protein measurement was used to determine platelet-related protein changes for 13 proteins.

Results: In T2D, from baseline to hypo, differences were seen for 4 PRPs, three showing increased percent change in study-2 (plasminogen activator inhibitor-1 (PAI-1) , platelet glycoprotein VI (PGVI) and Tissue factor) , one showing increased percent change in study-1 (CD40 ligand (CD40LG)) ; at 24-hours in T2D, percent change for CD40LG remained increased, together with von Willebrand factor (vWF) , in study-2. In controls, from baseline to hypo, differences were seen for four PRPs, three showing increased percent change in study-2 (PAI-1, CD40LG and Protein S) , one showing increased percent change in study-1 (vWF) ; at 24-hours in controls, percent change for Protein S remained increased in study-2, whilst percent change for vWF and plasminogen were increased in study-1.

Conclusion: Thrombogenic potential was enhanced in T2D versus controls, as evidenced by an increased thrombogenic protein expression profile in both mild and severe hypoglycemia, that showed persistent changes at 24-hours in severe hypo.

Disclosure

A. Moin: None. H. Kahal: None.
238-LB: Erythropoietin Receptor–Mediated Erythropoietin Regulation of Energy Metabolism in Mice
Authors: YIN WEIQIN , ROGERS HEATHER , RAJVANSHI PRAVEEN K. , AN XIULI , GASSMANN MAX , NOGUCHI CONSTANCE T.
Published: May 2022

EPO receptor (EPOR) expression in white adipose tissue (WAT) mediates EPO metabolic activity and mitochondrial biogenesis. Mice that lack EPOR in adipose tissue have increase fat mass accumulation, increased susceptibility to diet induced obesity and decreased WAT mitochondrial activity. Here we assess the potential for EPO to promote a metabolic response in liver, brown adipose tissue and skeletal muscle by assessing the extent of EPOR expression using the EpoR-dtTomato-Cre mouse. We quantified EPOR in liver, brown adipose tissue and soleus muscle compared with EPOR expression in subcutaneous and epididymal WAT and found the highest level in WAT by mRNA, protein and immunohistochemical analyses. Elevated EPO by intraperitoneal injection or by transgene over expression resulted in tissue specific changes in gene expression. In liver, EPO decreased expression of genes involved in gluconeogenesis and triglyceride secretion. In brown adipose tissue, EPO increased expression of thermogenic genes. In subcutaneous WAT, EPO decreased genes involved in lipogenesis. In soleus muscle, EPO decreased expression of lipolytic genes. These findings indicate that increased EPO decreases lipogenesis gene LPI, ACC1, ACC2 and Fas expression in the BAT, skeletal muscle, ScWAT, liver and eWAT and increases lipolysis gene Atgl and Hsl expression in the BAT, ScWAT, skeletal muscle, and Atgl expression in the liver and eWAT. Measurements of energy metabolism did not detect any changes associated with EPO treatment in energy expenditure, respiratory exchange ratio, locomotor activity and total activity. However, as observed in WAT, we also find that EPO promotes mitochondria activity in liver, brown adipose tissue and skeletal muscle indicated by elevated gene expression of CytC, Idh3α, Cpt1, Pgc-1α and Cox7a1. Together, these data support the hypothesis that EPO promotes lipolysis and inhibits fat synthesis to regulate body weight and fat mass. In addition, EPO may regulate glucose metabolism via inhibition of gluconeogenesis.

Disclosure

W. Yin: None. H. Rogers: None. P. K. Rajvanshi: None. X. An: None. M. Gassmann: None.
242-LB: Roux-en-Y Gastric Bypass and Vertical Sleeve Gastrectomy Showed Similar Efficacy in Achieving Cardiometabolic Composite Target in Subject with Type 2 Diabetes Undergoing Bariatric Surgery
Authors: MONTE LAVINIA , TUCCINARDI DARIO , ROSSINI GIOVANNI , WATANABE MIKIKO , POZZILLI PAOLO , NAPOLI NICOLA , MANFRINI SILVIA
Published: May 2022

Introduction: The ADA produced a triple composite outcome that summarizes the therapeutic targets of the three most prevalent complications of obesity: type 2 diabetes (T2D) , hypertension and dyslipidemia (HbA1c <7.0%; LDL cholesterol<100 mg/dL and systolic blood pressure <130 mmHg) . The present study primarily investigates the difference between Vertical Sleeve gastrectomy (VSG) and Roux-en-Y Gastric Bypass (RYGB) in achieving the composite target one year after the surgery. The secondary outcome assessed the success rate in achieving the separate components' target at months 6, 12 and 24 post-surgery.

Methods: This retrospective observational study evaluated 103 patients with obesity and T2D. At each visit, anthropometric measurements were recorded, and the metabolic and lipid profile was evaluated before surgery and subsequently during the follow-up visits at 6, 12 and 24 months post-surgery.

Results: Twelve months after surgery, patients undergoing RYGB did not show a significant difference compared to those undergoing VSG in achieving the composite target (P =.57) . Patients undergoing RYGB showed greater LDL target achievement at 6 months post-surgery than the VSG (P=.005) . Total cholesterol and LDL cholesterol were significantly reduced over time in the RYGB compared to the VSG (P=.023 and P=.010 respectively) .

Conclusion: RYGB and VSG showed similar efficacy in reaching the cardiometabolic ADA composite target in subjects with T2D undergoing bariatric surgery. Patients undergoing RYGB showed a significant reduction over time in LDL and total cholesterol compared to the VSG group. More extended randomized studies are needed to evaluate the effectiveness of the two surgical procedures in the improvement and remission of cardiovascular risk factors associated with obesity.

Disclosure

L. Monte: None. D. Tuccinardi: None. G. Rossini: None. M. Watanabe: Consultant; Novo Nordisk. P. Pozzilli: Advisory Panel; Dompé, Consultant; Abbott, Speaker's Bureau; Dompé, Lilly Diabetes, Medtronic, Sanofi. N. Napoli: Advisory Panel; Novo Nordisk, Consultant; Lilly Diabetes. S. Manfrini: None.
244-LB: GPR75 Ablation Protects against Diet-Induced Obesity, Inflammation, and Insulin Resistance
Authors: HOSSAIN SAKIB , DIRICE ERCUMENT
Published: May 2022

Obesity related conditions including atherosclerosis and type 2 diabetes mellitus (T2DM) have a profound effect on cardiovascular health and morbidity. Recent reports by Akbari et. al. indicate that truncated loss of function variants of the orphan G-protein coupled receptor, GPR75, are associated with 5.3 kg lower bodyweight and 54% lower odds of obesity in heterozygous individuals (Science, 2021) . Based on these findings, we hypothesized that whole body deletion of Gpr75 protects against diet-induced obesity (DIO) and the resulting insulin resistance. Wild-type and Gpr75 null mice were subjected to 14 weeks of regular chow or high-fat diet (HFD) feeding. Body weight, intraperitoneal glucose and insulin tolerance tests, and pro-inflammatory cytokine gene expressions were measured initially and at week 14. There were no significant differences in body weight, glucose homeostasis, and tumor necrosis factor alpha (TNF-α) expression between wild-type (WT) and Gpr75 -/- (KO) mice at baseline. However, WT mice obtained a diabetogenic phenotype after HFD-feeding while the KO counterparts were protected as indicated by reduced body weight, (45.32 ± 1.387 grams vs. 28.29 ± 1.47 grams) and increased sensitivity to insulin (blood glucose 30 min after insulin injection as percent change, -28.5 ± 4.41% vs. -50.68 ± 4.15%, p<0.0001) . This correlated with a 1.98-fold decrease in brown adipose tissue (BAT) and 2.31-fold decrease in subcutaneous adipose tissue (SAT) TNF-α mRNA expression in KO compared to WT mice. Furthermore, there was a 3.19-fold reduction in circulating chemokine ligand 5 (CCL5) in KO compared to WT mice. This data may provide a potential novel target for the control of obesity-driven disorders such as inflammation and insulin resistance.

Disclosure

S. Hossain: None. E. Dirice: None.

Funding

NIH123203
244-OR: Moderate Intensity Endurance Exercise Training Improves Late-Phase ß-Cell Function in Humans with Type 2 Diabetes
Authors: ZHANG HUI , MIDDELBEEK ROELAND , SIMPSON LAURA , CARBONE NICHOLAS P. , GOODYEAR LAURIE J.
Published: May 2022

Type 2 diabetes (T2D) is associated with β-cell dysfunction. Although exercise is considered beneficial in T2D, the effects of moderate intensity endurance exercise training on β-cell function in humans with T2D are not known. GWAS uncovered Ras-Responsive Element Binding Protein 1 (RREB1) as a risk factor for T2D and in vitro studies suggest RREB1 impairs β-cell function; no studies have investigated exercise effects on RREB1. Here, we determined the effects of moderate intensity exercise training on β-cell function, RREB1, insulin, glucagon, and amylin in humans with T2D (7F/3M, 49±5y, BMI 30±3kg/m2) . Subjects completed 10-weeks of supervised exercise (Wks 1-3: 20-30min/day; 3X/wk; ∼50% VO2peak and Wks 4-10: 45-60min/day; 4X/wk; ∼70% VO2peak) . Fasting blood samples for OGTT, HbA1c, and hormones were obtained pre- and post-training (48hr) . Serum RREB1 was measured pre- and post-training and also in response to a single bout of maximal exercise. Training decreased HbA1c (7.7% to 7.2%, P=0.01) , pro-insulin (-18%, P=0.03) , pro-insulin/c-peptide ratio (-8%, P=0.03) , and glucose (OGTT: 90min, -18%, P=0.01; 120min, -15%, P<0.001) . Both β-cell function (late-phase disposition index, +38%, P=0.01) and insulin sensitivity (Stumvoll Index, +25%, P=0.01) improved. Body weight and composition, VO2peak, glucagon, amylin, c-peptide, and insulin were unchanged. Baseline RREB1 negatively correlated with the exercise-induced increase in late-phase disposition index (R= -0.71, P=0.03) , consistent with an inhibitory role of RREB1. Training did not alter serum RREB1, but interestingly, acute exercise decreased RREB1 both before (-51%, P<0.01) and after training (-11%, P=0.04) . Thus, RREB1 is an exercise-regulated serum factor whose decrease may function to improve β-cell function with exercise.

In conclusion, moderate intensity exercise training, in the absence of increased VO2peak, improves late phase β-cell function and glucose control in humans with T2D.

Disclosure

H.Zhang: None. R.Middelbeek: Research Support; Novo Nordisk. L.Simpson: None. N.P.Carbone: None. L.J.Goodyear: None.

Funding

National Institutes of Health (K23-DK114550, R01-DK112283, 5P30DK36836, 5P30DK057521-20)
249-LB: PAX4 Loss of Function Alters Human Endocrine Cell Development and Influences Diabetes Risk
Authors: KRENTZ NICOLE , HUI LAU HWEE , ABAITUA FERNANDO , PEREZ-ALCANTARA MARTA , WEI CHAN JUN , AJEIAN JILA N. , CHAMPON BENOITE , SUN HAN , JHA ALOKKUMAR , HOON SHAWN , GARDNER DAPHNE , LING KAO SHIH , SHYONG TAI E. , GLOYN ANNA L. , TEO ADRIAN
Published: May 2022

In an effort to identify disease-causing mechanisms, numerous genome-wide studies across different ancestries have discovered genetic variants influencing type 2 diabetes (T2D) risk. Amongst identified diabetes-associated loci, a PAX4 coding variant (p.Arg192His) is uniquely and reproducibly associated with altered T2D-risk in East Asian populations. PAX4 encodes a transcription factor, and in mice Pax4 is essential for beta cell development. Whether PAX4 plays a similar role in humans and how diabetes associated PAX4 variants impact beta cell development and/or function is unknown. We combined in vivo studies in human variant carriers with disease modelling in human stem cell models to address these questions. Carriers of the PAX4 p.Arg192His allele have reduced islet cell function compared to non-carriers (AIRg: p.Arg192 756.9 vs. p.His192 530.8 p<0.002) . Deletion of PAX4 by CRISPR-Cas9 genome-editing in isogenic human induced pluripotent stem cell (hiPSC) -derived beta-like cells caused de-repression of alpha cell gene expression, suggesting decreased function in carriers of PAX4 variants may be due to altered beta cell development. hiPSCs derived from carriers of either the PAX4 p.Arg192His or a novel p.Tyr186X allele identified in a proband with early onset diabetes, had increased polyhormonal endocrine cell formation and reduced insulin content following in vitro differentiation towards beta-like cells; correction of the diabetes-associated PAX4 alleles reversed these phenotypic changes. Our in vitro and in silico molecular studies of diabetes associated alleles support reduced PAX4 expression and/or function. PAX4 knockdown in the EndoC-βH1 human beta cell model altered hormone gene expression, reduced total insulin content, and impaired insulin secretion.

In conclusion, we have demonstrated the importance of PAX4 for human endocrine cell development and provide a potential mechanism for diabetes-associated alleles through de-repression of alpha cell gene expression.

Disclosure

N. Krentz: None. S. Hoon: None. D. Gardner: None. S. Kao: None. E. Tai: Advisory Panel; Amgen Inc., Merck Sharp & Dohme Corp., Novartis AG, Novo Nordisk, Stock/Shareholder; Abbott, AbbVie Inc. A. L. Gloyn: Other Relationship; Genentech, Inc., Roche Pharmaceuticals. A. Teo: Stock/Shareholder; BetaLife Pte Ltd. H. Lau: None. F. Abaitua: Employee; Vertex Pharmaceuticals Incorporated. M. Perez-alcantara: None. J. Chan: None. J. N. Ajeian: None. B. Champon: None. H. Sun: None. A. Jha: None.

Funding

Wellcome (200837) ; National Institutes of Health (U01-DK105535, U01-DK085545, UM1DK126185, U01DK123743, U24DK098085, P30DK116074) ; Lee Foundation Grant (SHTX/LFG/002/2018) Paris-NUS 2021-06-R/UP-NUS (ANR-18-IDEX-0001)
250-OR: Role of Ezh2 in Hepatic Inflammation and Developmental Programming of Liver Disease
Authors: RUEBEL MEGHAN L. , JAMBAL PUREVSUREN , CHINTAPALLI SREE V. , CHEN JIN-RAN , SHANKAR KARTIK
Published: May 2022

Maternal obesity predisposes offspring to the development of fatty liver and nonalcoholic steatohepatitis. Using a well-established mouse model (C57BL6/J) of maternal high-fat, high sucrose diet (HFD) exposure, we characterized epigenomic alterations in adult offspring liver. ChiP-seq for six histone modifications were performed on offspring livers from dams fed either a AIN93G (CON, 7% fat calories, n=11) or HFD (45% fat calories, n=9) for 12 wk prior to pregnancy and through weaning. Offspring of HFD dams, showed a robust gain in repressive H3K27me3 modification mediated by the histone methyltransferase, Ezh2. Since Ezh2 has been implicated in modulating inflammatory signaling we examined if Ezh2 in macrophages contributes to hepatic inflammation following a high-fat palmitate/cholesterol (FPC) diet. We generated myeloid cell-specific Ezh2-knockouts (Ezh2-CKO) by crossing Ezh2-floxed (Ezh2f/f) mice to LysM-Cre expressing mice. At 5 weeks of age Ezh2-CKO and flox-control litter mates were provided ad libitum CON (n=22) or FPC diet (52% fat calories, n=22) for 14 days. At 7 weeks of age, body and liver weights were collected and liver tissue was flash frozen for RNA-seq analyses. Two-way ANOVA of liver to body weight ratios showed a significant diet effect (p<0.0001) , with increased ratios in the FPC group without effects of genotype. Transcriptomic analyses showed that the effects of FPC diet were diminished in CKO mice relative to flox controls (223 vs.132 DEGs in flox and CKO, respectively) with 2DEGs shared between genotypes. Ingenuity Pathway Analysis revealed signaling pathways and processes related to inflammation, macrophage and leukocyte activation, reactive oxygen species, and PPARα that were increased in the flox with FPC diets compared to CKO animals. Collectively, these findings reveal a role for Ezh2 in developmental programing of liver disease and hepatic inflammation, uncovering a novel epigenetic process influencing hepatic disease risk in offspring.

Disclosure

M.L.Ruebel: None. P.Jambal: None. S.V.Chintapalli: None. J.Chen: None. K.Shankar: None.

Funding

U.S. Department of Agriculture-ARS-CRIS (6251-51000-005-00D) NIH (P30DK048520-27, R01HD102726-01A1) Funds from the Department of Pediatrics, University of ColoradoAnschutz Medical Campus and the Anschutz Health and Wellness Center.
259-LB: Inhibition of the Polyamine-Hypusine Circuit Delimits Islet ß-Cell Stress in the Context of T1D via Suppression of IRE-1a Signaling
Authors: ANDERSON ANDY , KULKARNI ABHISHEK , MIRMIRA RAGHAVENDRA G.
Published: May 2022

Recent data suggest that stress-induced molecular pathways in the β cell may trigger the display of neoantigens that initiate autoimmunity in type 1 diabetes (T1D) . Polyamines (putrescine, spermidine, and spermine) are biogenic amines that participate in stress-induced mRNA translation, in part, through the posttranslational hypusine modification of eIF5A. Rate-limiting enzymes in this circuit include the ODC, which converts Arg to polyamines, and DHPS, which controls eIF5A hypusination. Previously, we showed that inhibition of ODC or DHPS in non-obese diabetic mice using either DFMO or GC7, respectively, resulted in preserved β-cell function, enhanced β-cell mass, and significantly reduced T1D incidence. DFMO treatment subjects with recent-onset T1D was suggestive of reductions in β cell stress. We hypothesized that polyamine depletion with DFMO reduces inflammatory stress in β cells and the consequent accumulation of unhypusinated eIF5A limits stress-related protein production. To test the hypothesis, we treated the human islets with proinflammatory cytokine (PIC) cocktail to mimic T1D in presence or absence of 5 mM DFMO. We observed induction of ER stress as shown by increased expression of unfolded protein response proteins within 24 h of PIC treatment. Treatment with DFMO reduced protein levels of IRE1α and downstream XBP1. Gene expression analysis showed significant downregulation of genes in the IRE1α pathway (CHOP, TNXIP, and XBP1s) . To clarify a mechanism underlying suppression of stress protein production by unhypusinated eIF5A, we treated HEK cells with DFMO or GC7, both of which enhanced the association of unhypusinated eIF5A with GCN2, an eIF2α kinase, suggesting a non-ER stress mediated mechanism of mRNA translational blockade. Collectively, these data suggest that inhibition of the polyamines-hypusine circuit suppresses ER stress via IRE1α signaling and enhances non-ER stress mediated suppression of mRNA translation.

Disclosure

A. Anderson: None. A. Kulkarni: None. R. G. Mirmira: None.