bluuebunny/crossref_metadata_2025_split huggingface dataset:
1569-P: Lysophosphatidic Acid Mediates Inflammation in Liver and White Adipose Tissue in a Rat Model of 1-acyl-sn-glycerol-3-phosphate Acyltransferase 2 Deficiency
Authors: SAKUMA IKKI , GASPAR RAFAEL C. , LUUKKONEN PANU , KAHN MARIO , MURRAY SUE , SAMUEL VARMAN , PETERSEN KITT , SHULMAN GERALD I. 
Published: June 2023

AGPAT2 (1-acyl-sn-glycerol-3-phosphate acyltransferase 2) converts lysophosphatidic acid (LPA) into phosphatidic acid (PA) and mutations of the AGPAT2 gene are responsible for the most common form of congenital generalized lipodystrophy (CGL) which leads to diabetes and steatohepatitis. The underlying mechanism by which AGPAT2 deficiency leads to these abnormalities has not been elucidated. We explored this question using an antisense oligonucleotide (ASO) to knock down expression of AGPAT2 in liver and white adipose tissue (WAT) of adult male SD rats. AGPAT2 ASO treatment induced lipodystrophic features in which adipose and hepatic inflammation were associated with increased LPA content in WAT (Control ASO=0.4 ± 0.1 nmol/g tissue; AGPAT2 ASO=0.8 ± 0.4, P&lt;0.05) and liver (Control ASO=2.7 ± 0.4 nmol/g tissue; AGPAT2 ASO=4.2 ± 0.9, P&lt;0.01) whereas PA content was unchanged. We hypothesized that increased LPA content may lead to inflammation in these tissues. We tested if either a controlled-release mitochondrial protonophore (CRMP) or an ASO against glycerol-3-phosphate acyltransferase, mitochondrial (GPAM) would reduce LPA content and inflammation in these tissues in AGPAT2 ASO treated rats. CRMP treatment (20 mg/[kg-day]) primarily prevented LPA accumulation in WAT (Control ASO=0.4 ± 0.1 nmol/g tissue; AGPAT2 ASO=0.9 ± 0.1; AGPAT2 ASO+CRMP=0.6 ± 0.1) (AGPAT2 ASO vs AGPAT2+CRMP P&lt;0.05) and prevented WAT inflammation. In contrast GPAM ASO treatment primarily prevented hepatic LPA accumulation (Control ASO=3.6 ± 0.4 nmol/g tissue; AGPAT2 ASO=4.8 ± 0.2; AGPAT2+GPAM ASO=2.7 ± 0.4) (AGPAT2 ASO vs AGPAT2+GPAM ASO P&lt;0.01) and prevented hepatic inflammation.
Conclusion: These results demonstrate a key role of LPA acid in mediating inflammation in liver and WAT in AGPAT2 deficient animals and identify novel therapeutic targets to treat CGL in patients with AGPAT2 deficiency.

Disclosure
I.Sakuma: None. R.C.Gaspar: None. P.Luukkonen: None. M.Kahn: None. S.Murray: Employee; Ionis Pharmaceuticals. V.Samuel: None. K.Petersen: Advisory Panel; Novo Nordisk, Research Support; Merck Sharp & Dohme Corp., Gilead Sciences, Inc. G.I.Shulman: Consultant; Novo Nordisk, DiCerna Pharmaceuticals, Inc., Bayer Consumer Care AG, Kriya Therapeutics, Arrowhead Pharmaceuticals, Inc., ESPERION Therapeutics, Inc., Other Relationship; AstraZeneca, Merck & Co., Inc., Janssen Research & Development, LLC, iMetabolic Biopharma Corporation, Maze Therapeutics, 89bio, Inc., Equator Therapeutics, Inc., Generian Pharmaceuticals, Fortress Biotech, Inc., OrsoBio, Aro Biotherapeutics Company, Stock/Shareholder; Levels Health, Inc.
1570-P: Myeloid-Specific Inactivation of Basp1 Protects Mice from Diet-Induced NASH through Attenuating NLRP3 Inflammasome Activation
Authors: MENG ZIYI , ZHOU LINKANG , HONG SUNGKI , LIU TONGYU , QIU XIAOXUE , CHEN ZHIMIN , LI SIMING , INOKI KEN , LIN JIANDIE 
Published: June 2023

Nonalcoholic steatohepatitis (NASH) is characterized by persistent liver injury, inflammation, and fibrosis. Myeloid cells, including macrophages and dendritic cells, play an integral role in host defense, tissue homeostasis, and disease progression. Despite this, how myeloid cells contribute to NASH pathogenesis remains obscure. We previously identified NASH-associated macrophages (NAMs) as a unique population of monocyte-derived macrophages in NASH liver. We observed that hepatic NAMs exhibited abundant expression of Brain acid-soluble protein 1 (Basp1), which was markedly induced in the liver upon diet-induced NASH in mice. We generated myeloid-specific Basp1 knockout (Mye-Basp1 KO) mice to determine its role in NASH pathogenesis. Compared to control, Mye-Basp1 KO mice displayed significantly improved liver injury and fibrosis following NASH diet feeding, as shown by lower plasma ALT/AST levels and reduced Sirius Red staining on liver sections, respectively. Hepatocytes from Mye-Basp1 KO mice contained smaller lipid droplets without altering the total liver triglyceride content. Mechanistically, bone marrow-derived macrophages (BMDMs) lacking Basp1 exhibited diminished response to pro-inflammatory stimuli. Importantly, Basp1-deficient BMDMs displayed impaired activation of the NLRP3 inflammasome and secretion of interleukin-1 beta. Together, we propose that Basp1 is a novel regulator of inflammatory signaling in myeloid cells that plays a critical role in NASH pathogenesis.

Disclosure
Z.Meng: None. L.Zhou: None. S.Hong: None. T.Liu: None. X.Qiu: None. Z.Chen: None. S.Li: None. K.Inoki: None. J.Lin: None.

Funding
National Institute of Diabetes and Digestive and Kidney Diseases (DK102456)
1572-P: USP30 Regulates Hepatic Mitophagy and Mitochondrial Function
Authors: FAGUNLOYE OLAYEMI G. , BELLO FIONA , VANDEVENDER AMBER , SIPULA IAN J. , JURCZAK MICHAEL J. 
Published: June 2023

Mitochondria regulate several cellular and metabolic processes, necessitating cells to employ highly evolved quality control mechanisms to remove damaged mitochondria through a selective form of autophagy called mitophagy. Mitophagy is a mitochondrial quality control pathway, mediated in part by the ubiquitination of outer mitochondrial membrane (OMM) proteins. USP30 is an OMM deubiquitinase that regulates mitophagy by degrading OMM ubiquitin, thus inhibiting mitophagy. Hepatic mitophagy is reduced in obese fatty liver and is associated with mitochondrial dysfunction. Whether USP30 regulates mitophagy in hepatocytes in vivo and affects mitochondrial function is currently unknown. Therefore, we utilized the Cre-lox system to modulate USP30 expression in vivo to determine the effects on hepatic mitochondrial and metabolic function. Tail-vain injection of AAV8-TBG-Cre into USP30fl/fl and wild-type C57BL6 male mice was used to generate liver-specific USP30 knockout (LKO) and control mice (WT). Mice were fed regular chow and sacrificed at 16 weeks of age, 6 weeks after AAV dosing. Mitochondrial respiratory capacity was assessed using purified liver mitochondria and lipid metabolism was assessed biochemically in mice liver and plasma. USP30 liver-specific deletion in mice resulted in an impaired mitochondrial respiratory capacity as evidenced by increased mitochondrial leak respiration and reduced ADP-stimulated respiration in LKO mice compared to WT, such that the respiratory control ratio was significantly reduced in LKO mice. There were no differences in liver triglyceride levels, nor plasma triglycerides or fatty acids, while plasma cholesterol levels were 25% reduced in LKO mice (p=0.051). These data demonstrate that USP30 is an important regulator of mitochondrial respiratory capacity in hepatocytes in vivo, and that USP30 may normally inhibit excessive non-selective mitophagy in otherwise healthy mice.

Disclosure
O.G.Fagunloye: None. F.Bello: None. A.Vandevender: None. I.J.Sipula: None. M.J.Jurczak: None.

Funding
National Institute of Diabetes and Digestive and Kidney Diseases (R01DK114012)
1577-P: Hepatic Steatosis and Glucose Intolerance in Liver-Specific Estrogen Receptor Alpha Knockout Mice
Authors: SUCUPIRA FELIPE , ARAUJO LAYANNE , PAULO CAMPOREZ JOAO 
Published: June 2023

One of the consequences of sedentary lifestyle and consumption of a high-fat diet is Nonalcoholic Fatty Liver Disease (NAFLD), which affects approximately 30% of adults and up to 10% of children in developed countries. Interestingly, metabolic complications, such as insulin resistance and obesity, are less frequent in young women than in men of the same age or in postmenopausal women. In fact, reduced estrogen concentration during menopause is associated with increased visceral fat, metabolic diseases, insulin resistance, and T2DM. However, how estradiol is related to the development and progression of NAFLD remains unknown. Therefore, the general objective of this project was to study (in vivo) the effects of estrogen receptor alpha (ERα) ablation on hepatic energy metabolism. To this end, C57BL6 mice with ERα deletion specifically in the liver were generated using the Cre-Lox system (LERaKO). Sixth-week-old mice (Control and LERaKO mice) were fed a high-fat diet (HFD) with 45% fat. LERaKO mice displayed no difference in final body weight compared with control mice after four weeks of HFD feeding. A glucose tolerance test (GTT) was also performed after four weeks of HFD feeding. LERaKO mice displayed an increase in glucose intolerance by ~21% (P&lt;0.05) compared with control mice, despite showing no difference in insulin secretion over the course of the GTT. Interestingly, we observed an increase in hepatic triglyceride (TAG) content by ~157% (P&lt;0.05) in LERaKO mice compared with control mice and a decrease in plasma triglyceride concentration. We did not observe a significant difference in the expression of pro- and anti-inflammatory genes, but observed a significant increase in the expression of genes related to lipid synthesis and gluconeogenesis (P&lt;0.05). Taken together, these data confirm the hypothesis that ERα plays a pivotal role in hepatic metabolism in mice, as liver-specific ERα ablation leads to glucose intolerance and hepatic steatosis.

Disclosure
F. Sucupira: None. L. Araujo: None. J. Camporez: None.

Funding
FAPESP (2021/02638-9)
1578-P: Hyaluronidase-1 Inhibits Hepatic Gluconeogenesis
Authors: CHEN XI , ZHU YI 
Published: June 2023

Hyaluronidase-1 (Hyal1) is a lysosomal hyaluronidase that intracellularly hydrolyzes hyaluronan (HA). Studies have demonstrated the critical role of Hyal1 in the development of diabetes-induced endothelium dysfunction. However, whether it plays a role in the development of glucose intolerance and obesity remains unclear. We treated Hyal1 whole-body knockout (Hyal1 KO) mice and liver specific overexpression (OE) of Hyal1 mice with a low-fat diet (LFD) or high-fat diet (HFD), Hyal1 KO mice gained similar body weight but developed glucose intolerance compared to littermate wildtype (WT) mice on HFD, the latter is primarily contributed by an increase in gluconeogenesis in the Hyal1 KO liver. In contrast, Hepatic OE of Hyal1 suppressed gluconeogenesis. However, the change in gluconeogenesis is unlikely mediated by digestion of extracellular HA by Hyal1 in the liver as albumin-driven expression of a more potent hyaluronidase Ph20 had no effect on glucose tolerance nor gluconeogenesis from pyruvate. Liver metabolites in the gluconeogenesis pathway were significantly increased by HFD, whereas this was significantly attenuated in hepatic Hyal1-OE mice. Glucose transportersGLUT1 and GLUT2 were not affected by Hyal1 OE. Hyal1 deletion does not affect overall gene expression, as revealed by mRNA-sequencing of liver. However, ATP generation measured by OCR before and after inhibiting ATPase is decreased in hepatocytes OE of Hyal1, which likely contributes to the reduced energy-consuming gluconeogenesis process in Hyal1 overexpressing hepatocytes. In summary, Hyal1 regulates gluconeogenesis independent of changes in extracellular HA content, gene expression, or glucose transporter abundance in hepatocytes. Reduced gluconeogenesis is likely due to the reprogramming of intracellular metabolism and a reduction in ATP production through a remain-to-understand lysosome to mitochondria crosstalk.

Disclosure
X.Chen: None. Y.Zhu: None.

Funding
U.S. Department of Agriculture-Agricultural Research Service (3092-51000-062)
1579-P: Impact of Adipose Tissue Insulin Sensitivity on Hepatic Insulin Sensitivity Preservation in Longitudinal Observation of Patients with NAFLD
Authors: SHIGIYAMA FUMIKA , HIRUMA SHIGENORI , KUMASHIRO NAOKI 
Published: June 2023

Hepatic insulin resistance associated with NAFLD is a major pathogenesis of type 2 diabetes and its complications. In addition to reducing lipids in the liver, identifying the factors that may preserve hepatic insulin sensitivity (H-IS) is crucial. In this study, we investigated the factors that may preserve H-IS in patients with NAFLD in longitudinal observations. Comprehensively, putative biomarkers in blood and urine, body composition, tissue-specific lipid accumulation and insulin sensitivity by 1H-MRS and hyperinsulinemic euglycemic clamp, respectively, and pathological diagnosis using liver biopsy were assessed in patients with NAFLD (n=62) at baseline. After more than one year of general treatment, consented 36 patients (average age 51.3±11.2, men n=21, diabetes n=23) were subjected to the same assessment as baseline. To investigate the indices associated with H-IS, all indices were compared between upper and lower one third patients of Δ% suppression of endogenous glucose production (EGP) (+11.5±4.0 vs. -10.9±5.1%, respectively). As results, body weight, fasting plasma glucose, HbA1c, muscle and adipose tissue insulin sensitivity, visceral fat, and adiponectin levels were significantly improved in improved H-IS group. Interestingly, Δhepatic lipid content or fibrosis index was not different between the improved and worsened H-IS groups. Furthermore, simple regression analysis with Δ% suppression of EGP and all indices revealed that Δ% suppression of free fatty acid, visceral fat area, and adiponectin levels were significantly associated with Δ% suppression of EGP. Multiple regression analysis with Δ% suppression of EGP and these three indices showed that only Δ% suppression of free fatty acid significantly associated with Δ% suppression of EGP. Taken together, not only lipid volume but also the quality of accumulated lipid is important to preserve hepatic insulin sensitivity in patients with NAFLD.

Disclosure
F.Shigiyama: None. S.Hiruma: None. N.Kumashiro: Research Support; Terumo Corporation, LifeScan Diabetes Institute, Sumitomo Dainippon Pharma Co., Ltd., Speaker's Bureau; Daiichi Sankyo, Novo Nordisk.
158-OR: Ceramides Predict the Development of Type 2 Diabetes
Authors: LEIHERER ANDREAS , MUENDLEIN AXEL , PLATTNER THOMAS , VONBANK ALEXANDER , MADER ARTHUR , SPRENGER LUKAS , MAECHLER MAXIMILIAN , LARCHER BARBARA , FRAUNBERGER PETER , DREXEL HEINZ , SAELY CHRISTOPH H. 
Published: June 2023

Ceramides recently have attracted interest as a marker of cardiovascular event risk. However, only little is known about their role in the development of type 2 diabetes (T2DM). We analyzed the ceramide ratio Cer d18:18/Cer d 18:24:0 (CerRatio) in 894 consecutive Caucasian patients who were referred to angiography for the evaluation of established or suspected stable coronary artery disease (CAD). T2DM was diagnosed according to ADA criteria. The incidence of T2DM was recorded over a follow-up time of up to 16 years (median: 13 [8-14] years). At baseline, the CerRatio was significantly higher in T2DM (n=239) than in nondiabetic patients (4.6e-2 vs. 3.9e-2, p&lt;0.001). During follow-up, diabetes was newly diagnosed in 71 patients, i.e. in 11% of the initially nondiabetic subjects. The CerRatio strongly predicted the incidence of T2DM both univariately (standardized OR 1.47 [1.11-1.96]; p=0.008) and in a multivariately adjusted model (figure) comprising age, sex, BMI, the presence of significant CAD at angiography, and hemoglobin A1c (HbA1c; OR=1.45 [1.07-1.98]; p=0.018). Though the CerRatio was significantly correlated with BMI (r=0.138, p&lt;0.001) and HbA1c (r=0.137, p&lt;0.001), applying a mediation analysis revealed that BMI and HbA1c had only marginal indirect effects (5, 7% and 3.6%, respectively) on the association of the CerRatio with T2DM incidence. We conclude that ceramides strongly and independently predict the development of diabetes.

Disclosure
A. Leiherer: None. A. Muendlein: None. T. Plattner: None. A. Vonbank: None. A. Mader: None. L. Sprenger: None. M. Maechler: None. B. Larcher: None. P. Fraunberger: None. H. Drexel: None. C.H. Saely: None.
1580-P: Role of Hepatic Glycogen on Nocturnal Gluconeogenesis in Type 2 Diabetes
Authors: UNNI UMA , YADAV YOGESH , MUGLER JOHN P. , CARTER RICKEY , BASU ANANDA , BASU RITA 
Published: June 2023

Higher gluconeogenesis (GNG) during the latter part of the night contributes to higher endogenous glucose production (EGP) in type 2 diabetes (T2D). We have shown that glycogen synthesis is reduced in T2D due to a functional defect in the rate-limiting hepatic glucokinase activity. Studies using MRIs have confirmed lower net hepatic glycogen content in T2D than subjects without diabetes (ND) before and after dinner. We hypothesize that increasing post dinner hepatic glycogen content might restore overnight EGP in T2D by reducing GNG. 14 T2D and 15 anthropometrically matched ND were randomly assigned to glycogen loading (GL; 60% carb) vs. non glycogen loading (NGL; 40% carb) meals for 3 days. [6,6-2H2] Glucose was infused to measure EGP. GNG was estimated with deuterium labeled water and glycogen content measured via C13 NMR in fed and fasted state. Results are shown in Figure1. Liver glycogen content was higher with GL vs NGL in both cohorts. EGP was higher (p&lt;0.05) in GL vs NGL throughout night in both cohorts. The percent contribution of GNG and glycogenolysis (GGL) to EGP averaged ~ 50% in ND throughout the night in both GL and NGL. In contrast, the percent contribution of GNG to EGP in T2D with GL was lower vs. NGL overnight (average ~48% vs. 60%) and matched the pattern observed in ND with GL. The results indicate that lower glycogen content in the liver contributes to increased nocturnal rates of GNG in T2D.

Disclosure
U.Unni: None. Y.Yadav: None. J.P.Mugler, iii: None. R.Carter: None. A.Basu: None. R.Basu: Consultant; Sparrow Pharmaceuticals Inc, Research Support; Abbott Diabetes, AstraZeneca.

Funding
National Institute for Health and Care Research (R01DK029953)
1583-P: Dynamic Tracking and Identification of Liver-Specific Secretory Proteins in the Circulation of Live Mice
Authors: KIM KWANG-EUN , MYOUNG SUH JAE 
Published: June 2023

Secretory proteins are an essential component of interorgan communication networks that regulate animal physiology. Current approaches for identifying secretory proteins from specific cell and tissue types are largely limited to in vitro or ex vivo models which often fail to recapitulate in vivo biology. As such, there is mounting interest in developing in vivo analytical tools that can provide accurate information on the origin, identity, and spatiotemporal dynamics of secretory proteins. Here, we describe iSLET (in situ Secretory protein Labeling via ER-anchored TurboID) which selectively labels proteins that transit through the classical secretory pathway via catalytic actions of Sec61b-TurboID, a proximity labeling enzyme anchored in the ER lumen. To validate iSLET in a whole-body system, we express iSLET in the mouse liver and demonstrate efficient labeling of liver secretory proteins which could be tracked and identified within circulating blood plasma. Furthermore, proteomic analysis of the labeled liver secretome enriched from liver iSLET mouse plasma is highly consistent with previous reports of liver secretory protein profiles. Taken together, iSLET is a versatile and powerful tool for studying spatiotemporal dynamics of secretory proteins, a valuable class of biomarkers and therapeutic targets.

Disclosure
K.Kim: None. J.Suh: None.

Funding
National Research Foundation of Korea (2018R1A2A3075389, 2016M3A9B6902871, 2017K1A1A2013124, 2021R1A2C2007573, 2020R1C1C1013927); KAIST Key Research Institutes Project; Bio and Medical Technology Development Program (2019M3E5D3073104); Ministry of Science
1588-P: Translatable Modeling of Glucagon Actions in Human iPSC-Derived Hepatocytes Uniquely Predicts Differential Clinical Responses to Glucagon Analog Agonist Molecules
Authors: ROELL WILLIAM , REGMI AJIT , BENSON CHARLES T. , COSKUN TAMER , MOYERS JULIE S. , ALSINA-FERNANDEZ JORGE , THOMAS MELISSA K. 
Published: June 2023

As the development of clinically efficacious glucagon receptor (GCGR) agonists for the treatment of metabolic diseases evolves, the challenge to identify physiologically relevant preclinical models that predict glucagon receptor actions in humans becomes ever more important. While many hepatocyte models are available, most fail to recapitulate fundamental metabolic regulatory responses to key physiologic stimuli including integration of glucagon and insulin actions that govern hepatic carbohydrate or lipid metabolism. We developed and optimized a human induced pluripotent stem cell (iPSC)-derived hepatocyte model to mimic physiologic insulin and glucagon signaling and counter-regulation of metabolic pathways. We leveraged the model to evaluate functional responses of different glucagon receptor agonist molecules to regulate carbohydrate and lipid metabolism. Unlike assays conducted in several other cell line and primary isolated hepatocyte systems, hepatic glucose output assays in the human IPSC hepatocyte model demonstrated substantial potency differences between two novel soluble glucagon analog agonists. These findings predicted differential dose-dependent blood glucose excursions in response to these agonists when administered in a single ascending dose study in healthy human volunteers. Modeling physiologic integration of insulin and glucagon signaling in a clinically translatable human iPSC hepatocyte model can advance understanding of the regulation of nutrient metabolism by glucagon receptor agonists in humans and support the development of novel therapeutic approaches to address metabolic disorders, including type 2 diabetes, obesity, and nonalcoholic fatty liver disease.

Disclosure
W.Roell: Employee; Eli Lilly and Company, Stock/Shareholder; Eli Lilly and Company. A.Regmi: Employee; Eli Lilly and Company. C.T.Benson: Employee; Eli Lilly and Company, Stock/Shareholder; Eli Lilly and Company. T.Coskun: Employee; Eli Lilly and Company, Stock/Shareholder; Eli Lilly and Company. J.S.Moyers: Employee; Eli Lilly and Company, Stock/Shareholder; Eli Lilly and Company. J.Alsina-fernandez: Employee; Eli Lilly and Company. M.K.Thomas: Employee; Eli Lilly and Company, Stock/Shareholder; Eli Lilly and Company.
1589-P: Portal Serotonin Is Critical for Efficient Hepatic Control of Systemic Glycemia
Authors: KIEDROWSKI MATTHEW , EL SANADI CAROLINE , PENN MARC S. , GEHO WALTER 
Published: June 2023

There is growing evidence for a portal factor, released following a meal, that combined with insulin, induces hepatic glycogen synthesis. We have developed an in vitro model that demonstrates that serotonin could be the portal factor. Using rat primary hepatocyte cultures in 6 well plates with 750,000 cells per well and a 4-hour treatment time, we observed that 0.1 mU/ml of human insulin resulted in generation of 8.8 ± 2.3 ng glycogen/ug total protein compared to 6.7 ± 1.0 ng glycogen/ug total protein, with 5 uM 5HT-serotonin. Interestingly, the combination of 0.1 mU insulin/ml and 5 uM 5HT-serotonin resulted in 22.5 ± 3.8 ng glycogen/ug total protein, a 256% increase in glycogen synthesis compared to insulin alone. In the absence of serotonin, it takes approximately 10-fold greater insulin to achieve the same levels of glycogen synthesis as insulin with serotonin. These data combined with the observation that 95% of serotonin is made in the gut, that gastrointestinal serotonin is released upon food ingestion and the growing evidence that obese subjects have decreasing levels of circulating serotonin, suggest that gastrointestinal serotonin could be the portal factor necessary for efficient hepatic control of system glycemia. These data further suggest that insulin insensitivity is due to loss of a critical co-factor binding, and that this co-factor is serotonin. In summary, type 1 diabetes is due to a deficiency of insulin and type 2 diabetes may be due to a deficiency of its co-factor, portal serotonin.

Disclosure
M.Kiedrowski: None. C.El sanadi: None. M.S.Penn: Consultant; Diasome, Quest Diagnostics. W.Geho: None.