bluuebunny/crossref_metadata_2025 huggingface dataset:
1166-P: Immunoproteasome Function in the Liver: A Proteomics Analysis
Authors: EDMUND AARON , YUN CHANGHO , KIM DO-HYUNG
Published: June 2021

The liver is a key metabolic organ with functions in glucose and lipid metabolism, and whose dysfunction and inflammation are intimately linked to many metabolic disorders such as type 2 diabetes, nonalcoholic fatty liver disease, and hepatocellular carcinoma. The immunoproteasome is an inducible type of proteasome that plays crucial roles in homeostasis, immunity, and inflammation. The immunoproteasome incorporates three catalytic β subunits; LMP2, MECL1, and LMP7 which replace the proteasome subunits β1, β2, and β5, respectively, in the presence of inflammatory cytokines. We previously showed that mTORC1 promotes immunoproteasome formation, indicating that nutritional status regulates immunoproteasome abundance. Despite its strong relevance to disease, the functions of the immunoproteasome remain poorly understood. In this study we sought to illuminate the functions of the immunoproteasome in hepatocyte metabolism through multiplexed proteomics using LMP2-/- primary mouse hepatocytes. Through Reactome Pathway and GO Biological Process analysis, we found that LMP2 depletion in primary hepatocytes reduces the abundance of proteins involved in glucose metabolism and detoxification of reactive oxygen species while increasing abundance of proteins involved in mitochondrial biogenesis, TCA cycle and electron transport chain, mitochondrial and peroxisomal fatty acid oxidation, and the unfolded protein response. Under interferon γ (IFNγ)-stimulated conditions, proteins in keratinization and apoptosis were reduced suggesting reduced inflammation in LMP2-/- hepatocytes, and proteins in fatty acid and amino acid metabolism are increased. Combined, these results suggest that the immunoproteasome might play important roles in hepatic metabolism.

Disclosure

A. Edmund: None. C. Yun: None. D. Kim: None.

Funding

American Diabetes Association (1-19-IBS-071 to D-H.K.); National Institutes of Health (5T32DK007203-40)
1175-P: Inhibition of FBXO48 Improves Metabolic Changes Associated with NAFLD by Inhibiting Proteasomal Degradation of Phosphorylated AMPKa
Authors: MURALI ANJANA , EDMUNDS LIA R. , XIE BINGXIAN , CHEN BILL , LIU YUAN , JURCZAK MICHAEL J.
Published: June 2021

Hypothesis: Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease in developed countries yet there are no FDA-approved therapies for the disease. AMPK is a cellular energy sensor that coordinates metabolic pathways to balance energy demand with production. Growing evidence suggests loss of AMPK activity contributes to NAFLD. We recently identified an orphan F-box protein, FBXO48, which mediates the ubiquitination and proteasomal degradation of phosphorylated AMPKα (pAMPK). We hypothesized that increasing pAMPK levels via inhibition of FBXO48 would improve glucose homeostasis and slow NAFLD progression.

Methods: Twelve-week old male wildtype (WT) mice were fed low-fat diet (LFD) or “fast food” diet (FFD) for 24 weeks and then given vehicle (VEH) or a small molecule FBXO48 inhibitor (SMI; 5 mg/kg/d) for 8 weeks. We measured changes in body weight/composition, performed glucose tolerance tests (GTT), and collected plasma and liver for analysis.

Results: SMI had no significant effect on body weight or composition, although body weight and fat mass were 2.4 and 2.1 g less in SMI FFD compared with VEH FFD mice, suggesting a modest effect on weight loss. SMI significantly improved glucose homeostasis in FFD mice and restored plasma glucose levels during GTT to those observed in LFD mice. SMI had no effect on liver triglyceride levels in LFD mice and produced a 15% non-significant reduction in FFD mice. Gene expression of inflammation markers Cd68 and Ccl2 were significantly reduced in SMI FFD compared with VEH FFD mice, as were markers of fibrosis Col1a1 and Col3a1.

Conclusions: Our data suggest that increasing pAMPK levels through inhibition of FBXO48 may be a viable treatment option for improving glucose homeostasis and reducing inflammation/fibrosis associated with NAFLD.

Disclosure

A. Murali: None. L. R. Edmunds: None. B. Xie: None. B. Chen: Board Member; Self; Generian, Employee; Self; Generian. Y. Liu: Employee; Self; Generian. M. J. Jurczak: None.

Funding

National Institute of Diabetes and Digestive and Kidney Diseases (DK007052R01, DK119627)
12-LB: Reduced Disease-Associated Microglial Phenotype Is Associated with Diabetes-Associated Alzheimer’s Disease
Authors: PENG XUEMIN
Published: June 2021

Introduction: Type 2 diabetes mellitus (T2DM) has a significantly increased risk of developing Alzheimer’s disease (AD). Amyloid-β (Aβ) as one of the main pathological features in AD increases in the brain of T2DM. A recent study identified a protective novel subset of microglial­ in AD—disease-associated microglia (DAM), the activation of which depends on TREM2(a myeloid cell membrane receptor) to phagocytose Aβ plaques. However, as to how T2DM increases Aβ deposition and the relationship between T2DM with DAM remain elusive.

Objective: This study aims to explore the relationship between progression of T2DM with DAM and Aβ.

Methods: In vivo experiment, the deposition of Aβ, inflammation as well as the phenotype of DAM were evaluated by RT-PCR and immunofluorescence in the cortex and hippocampus of 10-,15-,20-week old db/db mice and the age-matched WT control. Additionally, the effects of high insulin-induced insulin resistance (100nM) on the DAM signature markers and the production of inflammatory cytokines in BV-2 microglial cells were investigated in vitro.

Results: We found the soluble and insoluble Aβ40, Aβ42, Aβ plaques as well as inflammation in the cortex and hippocampus increased in the progression of T2DM. Correspondingly, the DAM phenotype was reduced in the cortex and hippocampus at relatively early stage of T2DM (10 weeks and 15 weeks), while it increased reactively at the late stage (20 weeks). Likewise, high insulin-stimulated BV-2 microglial cells showed reduced Trem2 level and DAM signature markers and increase inflammation as well as Erk1/2 level. However, after the treatment of Erk1/2 inhibitor, the BV-2 cells under high insulin showed restored Trem2 level and DAM phenotype.

Conclusion: T2DM brain has decreased DAM phenotype at a relatively early stage, which may explain the increased Aβ deposition. This may involve Erk1/2 -Trem2 signaling pathway, which could be a potential candidate especially at early stages for preventing T2DM-induced AD.

Disclosure

X. Peng: None.

Funding

National Natural Science Foundation of China (81974114)
120-OR: Dapagliflozin Increases Adiponectin and Its Receptors, and Reduces Inflammation and Ceramide Synthesis Enzymes in the Obese Prediabetic Dog
Authors: KABIR MORVARID , BERGMAN RICHARD N. , GOPAUL V. SASHI , YANG HSIUCHIUNG , KOLKA CATHRYN M.
Published: June 2021

Sodium glucose cotransporter-2 (SGLT2) inhibitors promote urinary glucose excretion, consequently reducing blood glucose. Previously we showed that 6 weeks of Dapagliflozin (Dapa) treatment improved insulin sensitivity and prevented weight gain. In addition, Dapa promoted adipose tissue (AT) beiging, lipolysis and decreased adipocyte size primarily in the visceral (VIS) depot in a canine model of mild type 2 diabetes. Little is known about the effects of Dapa on AT inflammation and ceramide synthesis in both the subcutaneous (SC) and VIS fat depots. Twelve dogs were fed a high fat diet for 6 weeks, then received a single low dose of streptozotocin (18.5mg/kg) to induce mild type 2 diabetes. Animals were then exposed to Dapa (n=6, 1.25mg/kg) or placebo (n=6) once per day for 6 weeks, while remaining on the high fat diet. At the end of the treatment, fasting plasma parameters were measured, and SC and VIS fat biopsies were obtained for molecular studies. Dapa increased adiponectin, adiponectin receptors 1 and 2 gene expression by 90%, 74% and 69% (<0.001) in VIS depot respectively. Adiponectin gene expression was upregulated by 85% in the SC (P<0.05). Inflammation markers such as TNFα and IL-6 are downregulated by 74% (P<0.05) and 86% (P<0.001) in the VIS depot respectively. In addition, genes involved in ceramide synthesis, toll like receptor 4 (TLR4) and serine palmitoyl-CoA transferase (SPTLC2) decreased by 77% and 73 % respectively (P<0.05) in the VIS depot.

In conclusion, Dapa promoted adiponectin and its receptors, decreased inflammation and enzymes involved in ceramide synthesis mainly in the VIS depot. These changes were independent of fasting glucose and insulin. Thus, for the first time we are beginning to identify mechanisms by which Dapa enhances AT function in regulating energy homeostasis and improving AT inflammation in mild type 2 diabetes canine model.

Disclosure

M. Kabir: None. R. N. Bergman: None. V. Gopaul: None. H. Yang: Employee; Self; AstraZeneca. C. M. Kolka: Research Support; Self; AstraZeneca.

Funding

National Institutes of Health
1207-P: Tracing Telomerase Reverse Transcriptase (Tert) Expression to a Dormant Preadipogenic Origin
Authors: LYNES MATTHEW , CARLONE DIANA L. , TOWNSEND KRISTY L. , BREAULT DAVID , TSENG YU-HUA
Published: June 2021

Adipocytes are the major cell type in adipose tissue responsible for maintaining whole body energy homeostasis, and they are continuously replaced via expansion and differentiation of undifferentiated preadipocyte cells that reside within the local niche. In these preadipocytes, the maintenance of telomere length by mouse telomerase reverse transcriptase (mTert) is critical to their function, and premature telomere shortening is associated with metabolic syndrome and insulin resistance, however the specific cell type that expresses mTert in the preadipocyte niche is unknown. In this study, we took a lineage tracing approach to follow the developmental contribution of cells that express the putative stem cell marker mTert to several tissues, including cells residing in adipose tissue stromal vasculature. Using bioluminescent imaging, we were able to localize cells belonging to the mTert lineage in 3 dimensions in live animals. By tracing the fate of cells that express mTert for up to 2 years across the life of individual animals, we identify all tissues that arise from these putative stem cells. Subcutaneous white adipose tissue, which is prone to hyperplasia, showed contribution from the mTert lineage that was increased by high fat diet feeding. Cells that express mTert isolated from adipose tissue expressed preadipocyte markers and they made up less than 2% of the total progenitor pool. The mTert-positive cells possessed the capacity to self-renewal and differentiate into adipocytes, however they required cell-cell contact with mTert-negative cells to proliferate. These data identify a new population of preadipocytes that may contribute to the depot-specific response to HFD. Since individual adipose depots have profoundly different endocrine and metabolic roles, the identification of progenitor cells with depot specific differentiation capacity may provide clues to the mechanisms that govern in whole body physiology.

Disclosure

M. Lynes: None. D. L. Carlone: None. K. L. Townsend: Other Relationship; Self; Neuright, Inc. D. Breault: None. Y. Tseng: Consultant; Self; Cellarity.

Funding

National Institutes of Health (T32DK007260, F32DK102320)
121-OR: Activation of FoxO1 Induces Akt Phosphorylation and Mimics the Metabolic Functions of Insulin without Proliferative Effects on 3T3-L1 Adipocytes
Authors: OHNO TOMOHIRO , ONO HIRAKU , TAKEDA KENJI , YOKOTE KOUTARO
Published: June 2021

Objective: Insulin promotes glucose uptake, lipogenesis, cell proliferation and cell growth mainly via Akt phosphorylation. FoxO1 is a substrate of Akt, which is inactivated when phosphorylated by Akt. Via this mechanism, FoxO1 antagonizes insulin. On the other hand, constitutive activation of FoxO1 reportedly enhances Akt phosphorylation. Thus, FoxO1 activation, via Akt phosphorylation, may mimic the functions of insulin.

Methods: We overexpressed constitutively-active FoxO1 (CA-FoxO1) and FoxO1Δ256, a dominant-negative mutant, in 3T3-L1 adipocytes by adenoviruses and investigated the effects of these proteins on insulin’s functions.

Results: CA-FoxO1 enhanced Akt phosphorylation, glucose uptake (275%, P<0.01), GLUT4 translocation and lipogenesis (176%, P<0.05) in the non-insulin stimulated state, while DNA synthesis was decreased (44%, P<0.01) in the insulin-stimulated state. Surprisingly, FoxO1Δ256 also enhanced Akt phosphorylation, glucose uptake (154%, P<0.05) and lipogenesis (268%, P<0.01) in the basal state. In contrast to CA-FoxO1, FoxO1Δ256 increased DNA synthesis (196%, P<0.01). FoxO1Δ256 did not exert a dominant negative action even on gene expressions related to adipocyte differentiation, de novo lipogenesis and cell cycle regulation. Akt phosphorylation was more strongly induced by CA-FoxO1 than by 3 nM insulin, while PI 3-kinase activation by FoxO1 was weaker than that induced by 3 nM insulin, indicating the mechanism of Akt phosphorylation by FoxO1 to mainly be downstream from PI 3-kinase. Expressions of IR-β, p110α, Rictor and TRB3 were not significantly affected.

Conclusion: Activation of FoxO1 selectively mimics the metabolic functions of insulin, without its proliferative effects. Contrary to previously reported results, FoxO1Δ256 does not always exert a dominant negative action.

Disclosure

T. Ohno: None. H. Ono: None. K. Takeda: None. K. Yokote: None.
122-OR: Insulin and C-Peptide in Human Choroid Plexus of Type 1 Diabetes Mellitus
Authors: LIU QING-RONG , ZHU MIN , MAZUCANTI CAIO , MARENCO STEFANO , EGAN JOSEPHINE M.
Published: June 2021

The choroid plexus (CP) produces cerebrospinal fluid (CSF) and forms a blood-CSF barrier. We already reported that mouse CP epithelial (CPE) cells synthesize and secrete insulin in response to serotonin but not glucose. We now report that insulin expression is present in human postmortem CP samples of humans - nondiabetic, T2DM, and T1DM - by RT-qPCR, in situ hybridization and LC-MS/MS based Selected Reaction Monitoring assay. Human CPE contains all the INS splicing machinery and the major INS splicing variants that are present in islets. Known β-cell specific transcription factors are also expressed in CPE, except for PDX1 and PAX4, which are absent. The SRM assay detected INS A-chain, B-chain, and C-peptide at similar levels in nondiabetic, T2DM, and T1DM islets and CP postmortem samples. Islet amyloid polypeptide (IAPP) expression was not detected in CPE in contrast to human islets where INS and IAPP mRNA, as expected, colocalize in β-cells. Furthermore, INS colocalizes with transthyretin (TTR) mRNA in CPE cells but in islets, TTR is expressed in α-cells and not β-cells. We found less or no expression of T1DM autoantigens in CPE compared to β-cells, with the exception of ICA1 (islet cell autoantigen1), which has similar expression in both tissues.

In conclusion, human CPE expresses and synthesizes insulin, it is protected from autoimmune destruction and from IAPP amyloidogenic fibril formation.

Disclosure

Q. Liu: None. M. Zhu: None. C. Mazucanti: None. S. Marenco: None. J. M. Egan: None.

Funding

National Institute on Aging
1220-P: Treatment with Testosterone Undecanoate Injections (TU) Results in Sustained Weight Loss in Men with Hypogonadism and Type 2 Diabetes: Update of Real-World Data from a Urological Practice
Authors: HAIDER AHMAD , HAIDER KARIM S. , SAAD FARID
Published: June 2021

Background: The prevalence of hypogonadism is particularly high in men with obesity and T2DM.

Methods: Of 361 men with hypogonadism and T2DM, 293 (81.2%) were obese, 61 (16.9%) overweight and 7 (1.9%) had normal weight. 183 received TU 1000 mg/12 weeks (T-group) following an initial 6-week interval, 178 opted against treatment (CTRL). Changes over time between groups were compared and adjusted for age, weight, waist circumference, fasting glucose, blood pressure, lipids and quality of life to account for baseline differences between groups.

Results: Mean baseline age: 61.8±5.3 years, mean (median) follow-up: 8.7±3.1 (10) years. T-group: weight decreased by 22.5±0.5 kg (unadjusted numbers in brackets) (from 114.1±14.0 to 89.5±7.9) at 12 years. CTRL: weight increased by 8.5±0.5 (from 102.8±14.0 to 103.9±10.1) (p<0.0001 for both). T-group: waist circumference decreased by 13.6±0.4 cm (from 117.1±14.4 to 98.9±4.9). CTRL: WC increased by 8.5±0.4 cm (from 116.9±14.0 to 118.2±8.5) (p<0.0001 for both). T-group: BMI decreased by 7.4±0.2 kg/m² (from 36.5±4.5 to 28.9±2.6). CTRL: BMI increased by 2.8±0.2 kg/m² (from 33.4±5.3 to 33.2±3.6) (p<0.0001 for both). There was a weight loss of 19.7±0.4% in the T-group and weight gain of 9.1±0.4% in CTRL (p<0.0001 for both). Waist:height ratio decreased by 0.08±0.00 (from 0.66±0.08 to 0.56±0.03) in the T-group and increased by 0.05±0.00 (from 0.66±0.08 to 0.67±0.05) in CTRL (p<0.0001 for both). Visceral adiposity index (VAI) decreased by 3.1±0.2 (from 5.8±3.1 to 1.9±0.5) in the T-group and increased by 3.7±0.2 (from 5.1±2.5 to 8.1±3.7) in CTRL (p<0.0001 for both). Since injections were administered in the office and documented, there was a 100% adherence to testosterone therapy.

Conclusions: Treatment with testosterone undecanoate injections results in profound weight loss that is maintained long-term with continued testosterone therapy.

Disclosure

A. Haider: Other Relationship; Self; Bayer AG. K. S. Haider: Other Relationship; Self; Bayer AG. F. Saad: Consultant; Self; Bayer AG, Stock/Shareholder; Self; AbbVie Inc., Bayer AG, Novo Nordisk.

Funding

Bayer AG
1232-P: A Total Weight Loss of 25% Shows Better Predictivity in Evaluating the Efficiency of Bariatric Surgery
Authors: TU YINFANG , PAN YUNHUI , HAN JUNFENG , PAN JIEMIN , BAO YUQIAN , YU HAOYONG
Published: June 2021

Objectives: The need for a unified definition of weight loss (WL) after bariatric surgery has recently been highlighted. We aimed to evaluate the reliability of two clinically common WL indications including percentage of total WL (%TWL) and percentage of excess WL (%EWL) through comparing their performances in predicting metabolic syndrome (MetS) remission 1 year after bariatric surgery.

Methods: A total of 430 individuals with obesity who underwent bariatric surgery were enrolled. Participants were evaluated for changes in anthropometric parameters, metabolic indexes, MetS components and medications before and 1 year after surgery. MetS was defined using the criteria of the National Cholesterol Education Program Adult Treatment Panel III criteria for Asian-Americans.

Results: The prevalence of MetS is 92.3% (397) at baseline. One year after bariatric surgery, 337 individuals (84.9%) were in MetS remission. The multivariate adjusted odds ratios (ORs) were 1.16 (95% confidence interval [CI] 1.10-1.22) for each 1% increase in %TWL for MetS remission and 1.18 (95% CI 1.11-1.25) for each 5% increase in %EWL. This association with MetS remission remained statistically significant for %TWL after additional adjustment for %EWL (P for trend 0.029), and disappeared for %EWL. Receiver operating curve (ROC) analyses showed that the %TWL was more predictive than the %EWL (AUC%TWL vs. AUC %EWL, 0.749 vs. 0.700, p=0.023). The Youden index indicated that the optimal %TWL cut-off point to identify MetS remission was 25%.

Conclusions: We recommend that good responders to bariatric surgery should be defined as those exhibiting % TWL ≥25%. Clinical Trial Registration: Evaluation of the effectiveness and safety of metabolic surgery for obesity: a clinical cohort study; Chinese Clinical Trial Registration:ChiCTR1900028513.

Disclosure

Y. Tu: None. Y. Pan: None. J. Han: None. J. Pan: None. Y. Bao: None. H. Yu: None.

Funding

National Key Research and Development Project of China (2016YFA0502003); National Natural Science Foundation of China (81670791); Municipal Natural Science Foundation of Shanghai (17ZR1421200); Shanghai Key Clinical Center for Metabolic Disease (2017ZZ01013)
1233-P: Relationship between Taste Recognition Thresholds and Obesity in Type 2 Diabetes
Authors: SAKAI CHIEKO
Published: June 2021

Objective: An increased taste threshold can often lead to lifestyle diseases such as obesity. However, little knowledge is available on whether the coexistence of obesity and diabetes affects taste recognition. Therefore, this study investigated the relationship between degrees of obesity and taste recognition thresholds for the 5 basic tastes (sweet, salty, sour, bitter, and umami) in patients with type 2 diabetes.

Methods: The study was performed in 30 outpatients (22 men and 8 women) with type 2 diabetes who were not receiving pharmacotherapy (age: 59.1 ± 13.0 years, BMI: 25.2 ± 3.8 kg/m2, HbA1c: 7.0 ± 1.2%, fasting plasma glucose: 137 ± 40 mg/dl). Taste recognition thresholds for the 5 basic tastes were evaluated with the filter paper disk method. The Mann-Whitney U test and Spearman’s test were used for analysis.

Results: Taste thresholds measured by perception levels in patients with type 2 diabetes were as follows: sweetness, 3.5 ± 1.5; saltiness, 2.6 ± 0.9; sourness, 3.2 ± 1.3; bitterness, 2.7 ± 1.3; and umami, 4.8 ± 1.3. The recognition thresholds for sweetness and sourness were significantly higher than in healthy people. (sweetness, 0.001; sourness, 0.007; both P < .05). The correlation coefficients between BMI and the 5 taste thresholds were not significant (sweetness, -0.075; saltiness, 0.060; sourness, -0.074; bitterness, -0.025; and umami, 0.211).

Conclusion: Although patients with type 2 diabetes who are not receiving pharmacotherapy have higher taste thresholds for sweetness and sourness than healthy people, these differences were not associated with the degree of obesity.

Disclosure

C. Sakai: None.
124-OR: Repetitive Ca2+ Waves Emanate from a Stable Leader Cell in Mouse Islets
Authors: CHABOSSEAU PAULINE L. , MARTINEZ-SANCHEZ AIDA , LECLERC ISABELLE , SALEM VICTORIA , RUTTER GUY A.
Published: June 2021

Pancreatic beta cells form a highly connected network within the islet, with transcriptomic and functional heterogeneity existing between individual cells. A sub-population of leader cells has been proposed to act as functional hubs, controlling islet responses to glucose and other secretagogues. Using high speed confocal Ca2+ imaging, we aimed here to examine (a) the role of these cells in wave propagation and (b) their stability over time.

Methods: Islets were isolated from C57BL6 male mice expressing the recombinant Ca2+ probe GCaMP6f selectively in the beta cell (Ins1Cre:GCaMP6f/f). Islets were then infected with an adenovirus expressing photo-activatable- (PA) mCherry. Ca2+ imaging was performed across a single islet plane in modified KREBS-Ringer medium at 11mM glucose using a Zeiss LSM 810 laser-scanning microscope and data acquisition at 5 Hz. Cells were photopainted by excitation of PA-mCherry at 405nm.

Results: Leader cells were identified as those exhibiting the first detectable increase in Ca2+ signal during subsequent Ca2+ waves. The great majority of islets (85%, n=26, three independent experiments) displayed repetitive Ca2+ waves (1.10±0.26 min-1), and 82.9±5.0% of waves propagated directly from an identifiable leader cell. There was an average of 2.5±0.4 leader cells per islet with 62.9±0.70% of waves emanating from a “principal” leader cell. Ca2+ imaging experiments performed 16 h after the original session revealed that 37±0.08% (n=4) of waves emanated from the same, now photopainted, leader cell.

Conclusions: These data suggest that (a) a complex, non-binary, heterogeneity exists between leader and follower beta cells, (b) leader behaviour is an intrinsic phenotype of a sub-population of cells with a half-life in this role of ∼12 h.

Disclosure

P. L. Chabosseau: None. A. Martinez-sanchez: None. I. Leclerc: Consultant; Spouse/Partner; Sun Pharmaceutical Industries Ltd. V. Salem: None. G. A. Rutter: Advisory Panel; Self; Sun Pharmaceutical Industries Ltd.
1240-P: Changes in Protein Expression during Islet Regeneration in a Cystic Fibrosis-Related Diabetes (CFRD) Ferret Model
Authors: ISMAIL HEBA M. , MIRMIRA RAGHAVENDRA G. , EVANS-MOLINA CARMELLA , BONE ROBERT N.
Published: June 2021

Diabetes is a common complication among persons with cystic fibrosis (CF), affecting nearly 20% of adolescents and 50% of all adults with CF. The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) knockout (KO) ferret is a well-characterized animal model of CF that exhibits distinct periods of dysglycemia and pancreatic remodeling that are similar to patterns observed in humans. After the first month of life (normoglycemia/Phase I), hyperglycemia develops during the second month of life (Phase II) with reduced islet mass, followed by a period of near normoglycemia (Phase III) during which the islet mass regenerates, followed by persistent hyperglycemia/CFRD at the 4th month of life (Phase IV). While dynamic changes in islet hormone mRNA levels have been described across these phases, changes in protein expression patterns have not been characterized. To this end, immunofluorescence was performed to characterize islet hormone expression patterns in age-matched CFTR KO and wild type (WT) ferrets, focusing on the regenerative Phase III. The relative intensity of immunofluorescent staining per islet area was calculated. Compared to WT ferrets, the relative staining intensity of insulin and glucagon increased (4.687 vs. 3.228, p<0.05 and 0.827 vs. 0.238, p<0.0001, respectively ), while the intensity of proinsulin decreased (1.061 vs. 1.455, p<0.05) in CF ferret sections. Our findings suggest increased efficiency of proinsulin processing and a potential compensatory upregulation of insulin expression during this phase with the surprising finding of increased glucagon expression. Additional studies are underway to further characterize changes in islet hormone expression across each of the four described phases as well as potential cellular dedifferentiation patterns.

Disclosure

H. M. Ismail: None. R. G. Mirmira: Advisory Panel; Self; Hibercell Inc., Sigilon Therapeutics, Inc., Veralox Therapeutics, Employee; Spouse/Partner; Beta Bionics, Inc. C. Evans-molina: Advisory Panel; Self; Provention Bio, Inc., Consultant; Self; Dompe, Other Relationship; Self; Bristol-Myers Squibb Company, Nimbus Pharmaceuticals, Pfizer Inc. R. N. Bone: None.
1244-P: The Protein Phosphatase PPm1k Regulates Ribosomal Protein S6 Phosphorylation in Beta Cells
Authors: DELEYE YANN , HERRING JACOB , HESS KAVAN H. , LEININGER BRENNAN , MCGARRAH ROBERT W. , TESSEM JEFFERY S. , WHITE PHILLIP J.
Published: June 2021

Phosphorylation of ribosomal protein S6 (RPS6) on ser235/236 and ser240/244 in the pancreatic beta cell increases cell size and insulin content and influences systemic glucose homeostasis. Our phosphoproteomic analysis identified the protein phosphatase, PPm1K, as a novel regulator of RPS6 phosphorylation. We find that beta cells account for most PPm1K expression within pancreatic islets and that exposure of INS1 832/13 beta cells to increasing concentrations of glucose results in suppression of PPm1K mRNA expression. siRNA mediated knockdown of PPm1K in INS1 832/13 cells, to levels achieved by glucose, increased insulin content and secretion in basal and glucose stimulated conditions that was accompanied by robust phosphorylation of RPS6 on ser235/236 and ser240/244. PPm1K knockdown did not increase phosphorylation of p70 S6 Kinase (S6K) or the mammalian target of rapamycin (mTOR) upstream of RPS6 suggesting that PPm1K regulates RPS6 phosphorylation in an mTOR-S6K independent manner. Accordingly, treatment with the mTORC1 inhibitor, Rapamycin, lowered S6K and RPS6 phosphorylation but did not override the effect of PPm1K knockdown to increase RPS6 phosphorylation compared to control siRNA treated cells. Lowering phosphorylation of PPm1K’s classical target, ser293 of the branched-chain keto acid dehydrogenase (BCKDH) with the small molecule, BT2, also did not impact the effect of PPm1K knockdown to increase RPS6 phosphorylation. Thus PPm1K exerts its effects on RPS6 phosphorylation in a BCKDH and mTOR/S6K independent manner. The effects of siRNA-mediated PPm1K knockdown on RPS6 phosphorylation were accompanied by a 1.5 fold increase in protein translation and the induction of an unfolded protein response as determined by an increase in XBP-1 splicing, and BiP expression. Together our data identify a new role for the phosphatase PPm1K as a glucose sensitive modulator of RPS6 phosphorylation and protein translation that impacts beta cell insulin content and secretion.

Disclosure

Y. Deleye: None. J. Herring: None. K. H. Hess: None. B. Leininger: None. R. W. Mcgarrah: None. J. S. Tessem: None. P. J. White: None.

Funding

American Diabetes Association/Pathway to Stop Diabetes (1-16-INI-17 to P.J.W.)
1255-P: The Role of BAI3 Adhesion G-Protein Coupled Receptor in Insulin Secretion and Glucose Tolerance
Authors: ALSHARIF HAIFA , RAHMAN MOSTAFIZUR , PATHAK ASMITA , TROMBLEY JOHN E. , BHATNAGAR SUSHANT
Published: June 2021

Insulin secretion from beta-cells of pancreatic islets is essential for regulating whole-blood glucose homeostasis. Impaired insulin secretion is an early event in the development of obesity-linked type 2 diabetes (T2D). However, underlying molecular mechanisms that cause a reduction in insulin secretion are not completely understood. We recently identified that brain angiogenesis inhibitor-3 (BAI3) adhesion G-protein coupled receptor is expressed in beta-cells, and when activated by its native ligand, complement-1q like-3 (C1ql3), blunts insulin secretion in response to cyclic adenosine monophosphate (cAMP) in an autocrine/paracrine manner. The expression of BAI3 is conserved in human islets, yet the role of islet BAI3 in whole-body glucose homeostasis remains uncharacterized. We generated C57BL6/J mice that are homozygous for the loss of the BAI3 gene by using CRISPR technology. Our data show that the BAI3-/- mice have reduced body weight and impaired glucose tolerance compared to the wild-type control (WT) mice. These mice have elevated in vivo insulin secretion after 10 min of glucose challenge and an increased ex vivo islet insulin secretion in response to stimulation by 40 mM KCL and 11 mM glucose with no effect observed at 2.8 mM glucose. Concomitantly, the insulin action is decreased in the BAI3-/- mice. These outcomes show that increased insulin secretion from beta-cells due to the loss of the BAI3 gene contributes to reduced insulin sensitivity and glucose tolerance. The expression of BAI3 is increased by obesity, indicating that the activation of BAI3 signaling may contribute to reduced insulin secretion, causing beta-cell dysfunction in T2D. In sum, we have established an important role of an understudied BAI3 GPCR signaling in inhibiting insulin secretion, potentially identifying an attractive target for novel T2D therapeutics.

Disclosure

H. Alsharif: None. M. Rahman: None. A. Pathak: None. J. E. Trombley: None. S. Bhatnagar: None.

Funding

National Institutes of Health (R01DK120684-01)
1268-PUB: The Relationship of Time-in-Range (TIR) and HbA1c and the Factors That Contribute to a Better TIR
Authors: GONG LI , XU WEN , LIN BEISI , LIU ZHIGU , YANG DAIZHI , WANG CHAOFAN , YAO BIN
Published: June 2021

Background: HbA1c, the current gold standard treatment target for patients with diabetes, cannot reveal the glucose fluctuation. Therefore, new metrics need to be incorporated with HbA1c to better understand the dynamic nature of glucose. As the use of continuous glucose monitoring (CGM) increases, there is a need to better understand key metrics of time in range 70-180 mg/dL (TIR).

Methods: Patients with T2DM underwent a 48-h to 72-h CGM were included and divided into two groups: low TIR group (LTIR, TIR<70%) and high TIR group (HTIR, TIR≥70%). The characteristics between the two groups were compared. The relationship of HbA1c, glucose variability, time above range (TAR), time below range (TBR) and TIR were analyzed. And the contributions of BG and PPG increments to TIR were investigated.

Results: A total of 110 patients were enrolled. The age, BMI, duration of disease, treatment types and the index of glucose variability were not statistically significant (P > 0.05) between the LTIR group (n=11) and the HTIR group (n=99). HbA1c (7.96±1.08% vs. 6.69±1.23%, p =0.002) and TAR (61.59±7.88% vs. 90.59±7.73%, p<0.001) were lower in the HTIR group than that in the LTIR group, but TBR did not differ between groups. We further evaluated the contributions of BG and PPG to TIR, It showed that the relative contributions of BG in the LTIR group and the HTIR group were(47%vs33 %, p = 0.045), while the relative contributions of PPG were (53% vs. 67%, p = 0.045)in the two groups, respectively.

Conclusions: TIR is correlated with HbA1c and TAR, but not TBR, indicating the need to control the hyperglycemia for a better TIR. Furthermore, BG seems to a predominant contributor to a better TIR, and obviously exceed PPG in the T2DM patients with TIR >70%.

Disclosure

L. Gong: None. W. Xu: None. B. Lin: None. Z. Liu: None. D. Yang: None. C. Wang: None. B. Yao: None.

Funding

National Key Research and Development Program of China (2016YFC1304801)
1288-PUB: Acute Inflammatory Response of Breaking Up Prolonged Sitting with Stair Climbing Exercise Snacks
Authors: CABRAL-SANTOS CAROLINA , RAFIEI HOSSEIN , LIRA FABIO S. , LITTLE JONATHAN P.
Published: June 2021

Understand the acute inflammatory disturbances is important for preventing early diabetes and obesity-related complications. This study aimed to determine whether breaking up prolonged sitting into brief several shorter bouts spread throughout the day (“exercise snacks”) associated a short-term dietary intervention (low- or high-carbohydrate) have the potential to alter the acute inflammatory response. Ten male and female healthy weight (Lean) and overweight-obese (OW) participants were randomized to non-training control group with either low-carbohydrate snack (9h sitting; LC) or matched for total energy high-carbohydrate snacks consumption (9h; sitting) and a high-carbohydrate snacks consumption plus stair-climbing intervention (8X15-30seconds; ACTIVE). The same high-glycemic index meals were consumed at 0, 3 and 6h at each condition. Blood samples were collected at baseline, 180, 360 and 540 minutes to assess Interleukin-6 (IL-6), Tumor necrosis factor-α (TNF-α) and Salivary Immunoglobulin A (SIgA) levels. Mixed models for repeated measures were undertaken to examine differences according to condition x time and with Bonferroni post-hoc test. Change in TNF-α levels was not different within or between conditions from both Lean and OW group (p=0.512). For IL-6 there were a main effect of time at 540min [X2(11)=23.15; p=0.01] only in HC condition for OW group. Regarding to SIgA, Lean group showed higher level of SIgA on Active compared to LC and HC condition in all time-points (p=0.001). In addition, adults with OW showed elevated SIgA levels on LC and HC condition (p=0.001) when compared with same condition from Lean group. Our data suggests that breaking up nine hours of prolonged sitting implicated in reduction of acute inflammatory IL-6 plasma levels. In addition, acute manipulation on diet (low- and high-carbohydrate) resulted in alterations in the response of SIgA, increasing its levels in overweight/obese adults.

Disclosure

C. Cabral-santos: None. H. Rafiei: None. F. S. Lira: None. J. P. Little: None.

Funding

Natural Sciences and Engineering Research Council of Canada; Fundação de Amparo a Pesquisa do Estado de São Paulo (2018/17648-7)
155-LB: Counterregulatory Response to Hypoglycemia after Short-Term Use of Low and Very Low Carbohydrate Diets in Children with Type 1 Diabetes (T1D)
Authors: FOX LARRY , PERMUY JOSEPH W. , SANTIAGO DELIAMILLE PEREZ , FOX MARY LOUISE , HOSSAIN MD JOBAYER
Published: June 2021

Background: Low carbohydrate (CHO) diets are used to improve diabetes control, but the safety of these diets has not been studied in children. We assessed counterregulatory response to hypoglycemia after short-term low (LC) or very low (VLC) CHO diets in children with T1D.

Methods: Epinephrine (epi), norepinephrine (NE), glucagon (gluc), and beta-hydroxybutyrate (BOHB) were measured before and immediately after becoming hypoglycemic at baseline and after 3 months on a LC or VLC diet (CHO made up 30-39% or 20-29% of total daily calories, respectively). 13 children were enrolled, mean (±SE) A1c 7.8±0.2%, diabetes duration 6.3±1.0 yrs. Participants were given sufficient insulin to decrease glucose to <60 mg/dL (<3.3 mmol/L). Continuous glucose monitoring (Dexcom® G5 or G6) was used to monitor glucose trends. Hypoglycemia was confirmed using a plasma glucose analyzer.

Results: Mean age (±SE) for LC and VLC, 10.5±1.7 (n=7) and 15.0±0.6 yrs (n=6), respectively. Epi increased in response to hypoglycemia at baseline in both groups (mean±SE increase, pg/mL) (LC 130.9±60.1, p=0.072; VLC 412.6±84.0, p= 0.008). At 3 mos Epi increased in LC (181.6±66.7, p=0.053) but not significantly in VLC (100.2±67.9, p=0.214). The change in Epi in response to hypoglycemia was significantly less at 3 mos vs. baseline in VLC (100.2±67.9 vs. 412.6±84.0, p=0.019) but not in LC (181.6±66.7 vs. 191.4±61.7, p=0.935). Change in NE, gluc and BOHB during hypoglycemia was similar in both groups when comparing 3 months of diet with baseline. There was no effect of diet when comparing baseline and 3-month changes in Epi, NE, gluc and BOHB in response to hypoglycemia.

Conclusion: Short-term use of a diet very low in CHO in children with T1D may adversely affect counterregulatory response to hypoglycemia, whereas LC diet did not affect response. Further studies are needed to confirm these findings and to assess whether these diets affect growth and development in young children.

Disclosure

L. Fox: None. J. W. Permuy: None. D. Perez santiago: None. M. Fox: None. M. Hossain: None.

Funding

Nemours Research Programs; Dexcom, Inc.
168-LB: Latent Autoimmune Diabetes in Youth (15–29 Years Old): The Heavier End of an Autoimmune Disease Spectrum
Authors: CHENG JIN , TANG XIAOHAN , YAN XIANG , LUO SHUOMING , LI XIA , ZHOU ZHIGUANG
Published: June 2021

Context: Latent autoimmune diabetes in youth (LADY) falls in a grey zone of the current diabetes scheme due to the lack of established definition and diagnosis criteria.

Objective: To investigate the prevalence and clinical features of LADY patients between 15-29 years old as a component of an age-related continuous diabetes spectrum.

Methods: This nationwide, multi-center, cross-sectional study included 1803 newly diagnosed diabetic youth of 15-29 years old across China from April 2015 to October 2017. Glutamic acid decarboxylase autoantibody (GADA) was screened in 1508 phenotypic T2DM subjects and those with positive GADA were defined as LADY. Metabolic status, insulin resistance and residual β-cell function of LADY were investigated and compared with other 658 adult-onset latent autoimmune diabetes (LADA) patients enrolled at the same time. The age-related characteristics of the latent autoimmune diabetes spectrum were explored.

Results: LADY accounted for 7.9% (119/1508) of the phenotypic T2DM youth. Compared with GADA-negative T2DM youth, LADY patients had better metabolic control, less insulin resistance, and lower levels of β-cell function, which were closely related to their GADA levels (all P < 0.05). After stratifying LADA patients according to their age of onset, the GADA level decreased across the LADY, ‘Y-LADA’ (young LADA, age of onset <60 years old) and ‘E-LADA’ (elderly LADA, age of onset ≥60 years old) groups, with the prevalence of metabolic syndrome, levels of insulin resistance and residual β-cell function presenting an increasing trend (all P <0.05).

Conclusions: A high prevalence of LADY exist in phenotypic T2DM youth. The latent autoimmune diabetes occurred at different ages formed a continuous clinical spectrum from LADY to LADA, in which the LADY patients carried heavier autoimmune load.

Disclosure

J. Cheng: None. X. Tang: None. X. Yan: None. S. Luo: None. X. Li: None. Z. Zhou: None.

Funding

National Science and Technology Infrastructure Program (2013BAI09B12, 2015BAI12B13); National Key R&D Program of China (2016YFC1305000, 2017YFC1309604)
169-LB: Type 1 Diabetes Mellitus and Stiff-Person Syndrome
Authors: ARAÚJO CÁTIA A. , BAPTISTA CARLA , PAIVA ISABEL , MORGADINHO ANA
Published: June 2021

Introduction: Type 1 diabetes mellitus (T1DM) is often associated with other autoimmune diseases. One of them is Stiff-Person Syndrome (SPS), a rare neurological disorder characterized by muscle spasms and progressive muscle stiffness, which most often affects females. Glutamic acid decarboxylase antibodies (anti-GAD) are associated with the pathogenesis of this disease as well as T1DM. These antibodies cause a deficit in the synthesis of γ-aminobutyric acid (GABA) that is essential both in the function as neurotransmitter and in the secretion of insulin in pancreatic β cells.

Clinical case: We present the case of a 32-year-old female patient diagnosed with T1DM at 18 years old. Currently under intensive functional insulin therapy and flash glucose monitoring (FGM). Since 2019 with subcutaneous insulin infusion system. At the age of 26, the patient reports dystonia in the left lower limb with subsequent involvement of the contralateral lower limb, upper limbs, trunk and face. Collaboration was made with the Neurology department. Among the laboratory findings, of note: positive serum anti-GAD65 (5437 U/mL; <1) and positive cerebrospinal fluid anti-GAD65 (126.23 U /mL; <1). The diagnosis of SPS was made. The patient started human immunoglobulin therapy with progressive clinical improvement. Estimated HbA1c from FGM was 6,8 % at February, 2021.

Discussion: The association between T1DM and SPS is frequent. In this case, a patient with a known history of T1DM was presented, but cases of diagnosis of T1DM in patients with SPS have also been described. About 43% of patients have T1DM at the time of diagnosis of SPS. Anti-GAD are involved in the pathophysiology of these two diseases and anti-GAD titers are much higher in cases of association with SPS (about 50 to 100 times). In the treatment of patients with T1DM, physicians should be alert to the onset of other autoimmune diseases and active surveillance is essential for early diagnosis.

Disclosure

C. A. Araújo: None. C. Baptista: None. I. Paiva: None. A. Morgadinho: None.
171-LB: Stress Hyperglycemia Is Associated with Higher Preadmission Glucose and Post-Discharge Diabetes Incidence
Authors: FANG SHUYANG , AIYEDIPE SAMUEL , KHAKHARIA ANJALI , GIRALDI ERICA , EASLEY KIRK A. , PHILLIPS LAWRENCE S. , RHEE MARY K.
Published: June 2021

Stress hyperglycemia is associated with worse outcomes, but its associated risks and contributors are not well known. We evaluated characteristics associated with high inpatient random plasma glucose levels (RPG) in a retrospective cohort of the national VA Health Care System. Patients were age ≥18 yrs, without diagnosed diabetes (DM), hospitalized ≥3 days in 2002-2014 with ≥2 RPGs, and had regular care ≥2 yrs before and ≥3 yrs after hospitalization. In 205,270 pts, mean age was 73.8 yrs and BMI 28.0 kg/m2; 96% were male, 75% white, 16% black. Second highest inpatient RPG levels (iRPG-2max) of <130, 130-139, 140-159, 160-179, 180-199, and ≥200 mg/dl were found in 63%, 10%, 13%, 6%, 3%, and 4% of patients, respectively, without demographic differences between groups. Those with higher iRPG-2max had longer lengths of stay (LOS; median 5 days with <130 mg/dl vs. 10 days with ≥200, p<0.001), and higher rates of acute kidney injury (AKI; 9.3% with <130 vs. 29.3% with ≥200 group; OR 3.8, 95% CI 3.6-4.0) but no differences in rates of infection. Before admission, higher iRPG-2max groups were more likely to have ≥2 outpatient RPGs (oRPG) ≥130 mg/dl (7.2% with <130 mg/dl vs. 15.2% with ≥200, p<0.001). After discharge, higher iRPG-2max groups had more incident DM within 1 and 3 yrs (1.3% and 3.4%, respectively, with <130 vs. 14.9% and 18.4% with ≥200, both p<0.001). In multivariate analysis, higher iRPG-2max was more likely with oRPG ≥130 mg/dl vs. oRPG <110 (adj OR 1.81, 95% CI 1.75-1.87), and with DM in 3 yrs post-discharge vs. no DM (adj OR 2.52, 95% CI 2.49-2.70).

Conclusion: Patients with outpatient random plasma glucose (RPG) ≥130 mg/dl have a higher risk of stress hyperglycemia, which is associated with longer length of stay, more acute kidney injury, and higher incidence of diabetes after discharge. Thus, patients with ≥2 pre-admission RPGs ≥130 should have inpatient RPGs monitored carefully, and those with high inpatient RPGs should be screened for diabetes for up to 3 years after discharge.

Disclosure

S. Fang: None. S. Aiyedipe: None. A. Khakharia: None. E. Giraldi: None. K. A. Easley: None. L. S. Phillips: Other Relationship; Self; Diasyst Inc., Research Support; Self; AbbVie Inc., Eli Lilly and Company, GlaxoSmithKline plc., Janssen Pharmaceuticals, Inc., Kowa Pharmaceuticals America, Inc., Novartis Pharmaceuticals Corporation, Novo Nordisk Pharma Ltd., Pfizer Inc., Sanofi-Aventis. M. K. Rhee: None.
176-LB: The Impact of COVID-19 Infection on Subsequent Glycemic Control
Authors: THURBER EMILIA G. , MCDONNELL MARIE E. , CROMWELL GRACE , JOHNSON MATTHEW , SIMONSON DONALD C. , PALERMO NADINE E.
Published: June 2021

Recent studies suggest COVID-19 infection has a detrimental effect on glycemic control in patients with diabetes in the acute care setting. However, there is limited information about the impact of COVID-19 on glycemic control in the months following infection. In this retrospective observational study, we examined the correlation between COVID-19 infection and glycemic control in adult patients with elevated A1c in a single health system (n=3,295). Patients were selected from a cohort of those age 18 years or older who were tested for COVID-19 between 3/1/2020 and 11/1/2020. COVID positive patients were identified through positive SARS-CoV-2 PCR or a COVID flag in the EMR. COVID negative patients were randomly selected in a 3:1 ratio from all patients who had a negative COVID test in the same week as each positive patient. Patients from this cohort were included if they had a baseline A1c ≥ 5.7% measured in the preceding six months and at least two weeks prior to their COVID positive (n=670) or COVID negative (n=2,625) test date, as well as an endpoint A1c ≥ 5.7% at least three months after this date. The study population was 54% female, 60% White, 20% Hispanic, and 13% Black with a mean BMI 32 ± 7.3 kg/m2, age 64.1 ± 13.6 yrs, and baseline A1c of 7.7± 1.6 %; 81% of patients had a diagnosis of type 2 diabetes. In a linear regression model, COVID-19 infection was significantly associated with increased endpoint A1c (coefficient = 0.14, 95% CI [0.03 - 0.25], p = 0.01). Baseline A1c, male sex, and Hispanic ethnicity were also significantly associated with increased A1c, while age and median income based on zip code were associated with decreased A1c. In conclusion, prior COVID-19 infection appears to be associated with worse glycemic control at least 3 months post-infection compared to patients who did not contract COVID-19. Additional research is needed to determine if this association is present in other patient populations as well as the physiologic and socio-demographic causes for this finding.

Disclosure

E. G. Thurber: None. M. E. Mcdonnell: Stock/Shareholder; Spouse/Partner; Abbott Diabetes. G. Cromwell: None. M. Johnson: None. D. C. Simonson: Stock/Shareholder; Spouse/Partner; Phase V Technologies, Inc. N. E. Palermo: None.