bluuebunny/crossref_metadata_2025 huggingface dataset:
1642-P: Deferoxamine Prevented Dexamethasone-Induced Muscle Atrophy through Inhibition of KLF15 and FOXO3a
Authors: KIM YUJIN , LEE NAMI , CHOI SUJI , KIM YOUNGHA , SON YOUNGHO , CHOI SUNGE , KANG YUP Y. , YOUNG JEON JA , JIN HAN SEUNG , JIN KIM HAE , JUNG KIM DAE , HO KIM TAE , AN SOYEON , LEE KWANWOO
Published: June 2023

Aim/hypothesis: Muscle atrophy is caused by various factors such as aging, a lack of exercise, and diseases. During these events, the balance between protein synthesis and degradation is disrupted and finally muscle mass is decreased. This has been reported to occur via the ubiquitin-proteasome dependent pathway, autophagy, or apoptosis. In this study, we investigated the main mechanisms of dexamethasone-induced muscle atrophy and preventing mechanisms of deferoxamine on DEX-induced muscle atrophy.

Method: To measure the effects of DFO on muscle atrophy, C2C12 myotubes were treated with dexamethasone, with or without DFO, then myotubes atrophy was measured by phalloidin staining, RT-PCR, and western blotting.

Results: In differentiated C2C12 myotubes, DEX induced muscle atrophy in a time- and dose-dependent manner. DEX induced expressions of muscle-specific ligases, including muscle ring finger 1 and muscle atrophy F box, and activated the ubiquitin-proteasome system leading to muscle atrophy, not autophagy or apoptosis. Interestingly, DFO administration alleviated DEX-induced myotubes atrophy. DFO inhibited DEX-activated expressions of KLF15, not REDD or FOXO3a. DFO dramatically diminished FOXO3a translocation from cytosol to nucleus through the activation of AKT. Finally, expressions of muscle-specific ligases, such as MURF1 and Atrogin-1, were reduced by treatment of DFO, and ubiquitinated myoprotein was also reduced. In addition, mice treated with DEX for 12 days had a significant decrease in grip strength and TA muscle mass. However, treatment with DFO prevented DEX-induced reduction of muscle fiber size, loss of TA muscle, and grip strength.

Conclusion: DEX activated muscle specific E3 ligase and induced-muscle atrophy through ubiquitin-proteasome system. DFO ameliorates muscle atrophy by inhibition of E3 ligase expression via KLF15 and FOXO3a in DEX-treated C2C12 myotubes and C57BL6J mice.

Disclosure

Y.Kim: None. H.Kim: None. D.Kim: None. T.Kim: None. S.An: None. K.Lee: None. N.Lee: None. S.Choi: None. Y.Kim: None. Y.Son: None. S.Choi: None. Y.Y.Kang: None. J.Jeon: None. S.Han: None.
1643-P: Unique Signature of Circular RNA in Skeletal Muscle of Different Insulin Sensitivity
Authors: YEPMO MÉLISSA , MEUGNIER EMMANUELLE , PINGET MICHEL , BOUZAKRI KARIM
Published: June 2023

Diabetes pathologies are complex, affecting numerous organs such as liver, pancreas, and skeletal muscle. Circular RNAs (circRNA) are a class of non-coding RNAs that are characterized by a covalently closed loop structure. Functionally, they can act on cell physiology by sponging microRNAs and thus regulating gene and protein expression. The emerging function of these circRNA is not fully understood, but initial studies have recently shown that circRNA are involved in insulin secretion regulation. Therefore, deregulation of this class of RNAs may lead to metabolic disorders in pancreatic β-cells and thus be involved in the pathogenesis of type 1 (T1DM) and type 2 diabetes (T2DM). Our research is focused on the unique signature by circular RNA and the impact on skeletal muscle metabolism. We demonstrated that human skeletal muscle cells in culture maintain their gene expression phenotype. A different gene signature of the cells according to their different muscular fiber type sources (oxidative versus glycolytic versus mixt) was confirmed. Moreover, an independent microRNA composition has also been highlighted. As CircRNA can regulate microRNAs and then gene expression and proteins, we wondered whether these observed signatures could be explained by circRNA. We therefore focused on key circRNAs involved in myogenesis (such as circZNF609, circHIPK3) and we were able to see that there is a difference in expression of circRNA according to the muscle type. Moreover, we analyzed correlations between circRNA levels and insulin sensitivity (measured by PKB phosphorylation). Finally, we are currently completing our analysis with in-depth sequencing techniques to identify all expressed circRNA in muscle fiber types to potentially identify new targets in insulin metabolic pathways.

Disclosure

M.Yepmo: None. E.Meugnier: None. M.Pinget: Consultant; Novo Nordisk, Stock/Shareholder; ILONOV. K.Bouzakri: Consultant; Adocia, Stock/Shareholder; ILONOV.
1647-P: Novel Functions of CXCL12 as a Brown Adipocyte–Derived Secreted Factor
Authors: AGUEDA OYARZABAL MARINA , PLUCINSKA KAJA , SOPHIE ISIDOR MARIE , INGERSLEV LARS R. , PETERSEN PATRICIA , DMYTRIYEVA OKSANA , HENNINGSEN JO , BROWN ERIN , RUPAR KAJA , TOZZI MARCO , SCHWARTZ THUE W. , SCHÉELE CAMILLA C. , EMANUELLI BRICE
Published: June 2023

The capacity of brown adipose tissue (BAT) to regulate metabolism through cold-induced thermogenesis and secretion of molecules appeals as a potential therapeutic against metabolic disease. BAT secreted factors have gained interest as they may coordinate the adaptive response to cold and tissue remodeling. Yet, BAT secretory functions need deeper investigation before identifying druggable candidates. Thus, our group aimed to study secreted factors from active brown adipocytes that may sway adipocyte function and/or may orchestrate inter-cellular communications. For this, mRNA levels in mature adipocytes of brown, beige and white adipose depots from mice exposed to 21 days of cold were evaluated using RNA sequencing, and bioinformatic analysis was used to filter for potentially secreted factors. Cxcl12 was found to be the most cold-induced chemokine specifically in BAT. mRNA expression analysis of Cxcl12 by qPCR and fluorescence in-situ hybridization revealed its enrichment in brown adipocytes upon cold. Cold also increased CXCL12 levels in BAT media but not plasma, indicating a potential local action. Cxcl12 knockdown in active brown adipocytes impaired thermogenesis, estimated by Ucp1 gene expression, norepinephrine-induced lipolysis and mitochondrial respiration, despite intact β-adrenergic signaling, as estimated by immunoblotting of phosphorylated proteins. Together, these data suggest that Cxcl12 regulates adipocyte function independently from the β-adrenergic pathway. Additionally, CXCL12 exerted inter-cellular crosstalks by promoting macrophage chemotaxis and neurite outgrowth in vitro.

Here we present CXCL12 as a novel brown adipocyte, cold-induced secreted factor involved in adipocyte function and inter-cellular crosstalk within BAT. Further characterization of the role of CXCL12 and other secreted factors in BAT will provide valuable knowledge on the adaptive mechanisms of BAT to cold and may open new avenues to leverage BAT functions for the treatment of metabolic disease.

Disclosure

M.Agueda oyarzabal: None. M.Tozzi: None. T.W.Schwartz: None. C.C.Schéele: Research Support; Novo Nordisk A/S. B.Emanuelli: None. K.Plucinska: None. M.Isidor: None. L.R.Ingerslev: None. P.Petersen: None. O.Dmytriyeva: None. J.Henningsen: None. E.Brown: None. K.Rupar: None.

Funding

Novo Nordisk Foundation (18CC0034900, 19SA0035436); Copenhagen Bioscience PhD Program
1648-P: Triagonism Targeting GCGR/GLP-1/GIP-1 Receptors Improves Insulin Sensitivity in Obese Mice
Authors: KIM TEAYOUN , NASON SHELLY , ANTIPENKO JESSICA , HABEGGER KIRK M.
Published: June 2023

Glucagon is best known as the primary counter-regulatory hormone against insulin action. Glucagon secretion is likewise elevated in Diabetes and thus it is often implicated as a diabetogenic hormone. However, emerging data from our group and others have uncovered that Glucagon receptor (GCGR) agonism improves insulin sensitivity in both lean and obese mice. Mechanistically, this improvement is associated with enhanced AKT phosphorylation and mTOR signaling in the liver. Novel, single-molecule, triagonists targeting GCG/GLP-1/GIP receptors (GGG) have recently been described to exert stronger anti-obesity effects than dual or single agonism in obese mice. Thus, we evaluated the effect of these agonists on insulin sensitivity using hyperinsulinemic euglycemic clamp. Diet-induced obese (DIO) mice were randomly assigned to 4d treatment (10 nmole/kg subcutaneous injection) of vehicle, GGG, GCGR agonism (IUB288), GLP-1R agonism (Semaglutide), or a long-acting GIP-1R agonist (GIP-FA 085). On the fourth day, mice were fasted for 5 hours, continuously infused with 1.2mU/kg/min insulin, and blood glucose levels clamped around 80-100 mg/dL. Under these conditions Semaglutide and GGG treatments stimulated the greatest glucose infusion rate (p<0.0001) and significantly improved insulin-mediated suppression of Endo Ra (p<0.01). Smaller, but significant, enhancement was also observed in the IUB288-treated mice. Moreover, [14C]-2GDp uptake into brown adipose tissue was improved in GGG, Semaglutide, and IUB288 treated mice compared to Vehicle treated mice. Importantly, these improvements in insulin sensitivity and glucose dynamics were body-weight independent. Therefore, GCGR and GLP-1R signaling combine in GGG triagonism to improve insulin sensitivity mainly via suppression of hepatic glucose production.

Disclosure

T.Kim: None. S.Nason: None. J.Antipenko: None. K.M.Habegger: Consultant; Glyscend Inc., Research Support; Eli Lilly and Company, Novo Nordisk, Glyscend Inc., Stock/Shareholder; Glyscend Inc.

Funding

Eli Lilly and Company
165-LB: Circulating Metabolomic Biomarkers of Glycemic Control in Youth with Type 2 Diabetes (T2D)
Authors: CHEN ZSU-ZSU , LU CHANG , SHI XU , ZHENG SHUNING , WOLFS DANIELLE , BJORNSTAD PETTER , GERSZTEN ROBERT E. , ISGANAITIS ELVIRA M.
Published: June 2023

There are few biomarkers of glycemic response among youth with T2D, despite increasing disease prevalence and suboptimal response to approved therapies. We hypothesized that plasma metabolites may predict glycemic outcomes in youth-onset T2D. We measured 480 metabolites in fasting plasma samples in the Treatment options for T2D in Adolescents and Youth (TODAY) study (n=391), in which youth with T2D aged 10-17 years were randomized to metformin alone, metformin + rosiglitazone, or metformin + intensive lifestyle intervention. Metabolite associations with loss of glycemic control (defined as HbA1c ≥8% for 6 months or need for insulin therapy) were modeled using Cox proportional hazards regression adjusted for baseline age, sex, race/ethnicity, BMI, treatment group, and fasting glucose. Loss of glycemic control was observed in 150 of 391 youth (mean 2.6 years). Baseline levels of 11 metabolites were associated with loss of glycemic control (FDR<0.05, Fig. 1A). Treatment group modified the association of hexose and xanthurenic acid levels with glycemic control. For both compounds, youth with higher baseline levels had a lower risk of treatment failure when randomized to metformin therapy alone (Fig. 1B). Thus, metabolomics provides insight into circulating analytes associated with loss of glycemic control, and may highlight different effects of specific treatments in youth with T2D.

Disclosure

Z. Chen: None. C. Lu: None. X. Shi: None. S. Zheng: None. D. Wolfs: None. P. Bjornstad: Advisory Panel; AstraZeneca, Novo Nordisk, Lilly, Horizon Therapeutics plc, Boehringer Ingelheim (Canada) Ltd., LG Chem, Consultant; Bayer Inc., Bristol-Myers Squibb Company. R. E. Gerszten: None. E. M. Isganaitis: None.

Funding

National Institutes of Health (K23DK127073)
1660-P: Lactate Inhibits Lipolysis in Healthy Males—A Randomized Crossover Trial
Authors: PEDERSEN METTE G.B. , RITTIG NIKOLAJ , SØNDERGAARD ESBEN , GORMSEN LARS C. , MØLLER NIELS
Published: June 2023

Background: The intermediary metabolite lactate has signaling capacities through the lactate specific receptor GPR81/HCA1. Ex-vivo, lactate inhibits lipolysis through GPR81, but in-vivo human data are scarce. Lactate-mediated inhibition of lipolysis could improve insulin sensitivity. The aim of the study was to investigate if hyperlactatemia at physiological concentrations inhibits palmitate lipolysis and affects glucose metabolism in healthy males.

Methods: In a randomized cross-over design, eight healthy men were studied after an overnight fast on two occasions 1) during a sodium-lactate infusion (LAC) and 2) during a NaCl infusion (CTL). Both study days comprised a 3-hour basal period followed by a 3-hour hyperinsulinemic euglycemic clamp (HEC) period. Lipolysis rate and endogenous glucose production (EGP) were evaluated using [9,10-3H]-palmitate and [3H]-glucose tracers. Average glucose infusion rate (mg/kg/min) during the last 30 min of the HEC (M-value) was used as a measure of insulin sensitivity. Data are mean±SD

Results: Plasma lactate increased to 2.6 ±0.6 mmol/L during LAC vs. 0.8 ±0.3 mmol/L during CTL (p<0.001). At the end of the basal period, palmitate flux was 30% lower during LAC compared with CTL (84 ±32 μmol/min vs. 120 ±35 μmol/min, p=0.003). At the end of the HEC, palmitate flux was similarly suppressed during both interventions (p=0.7). Plasma FFA were lower during LAC compared with CTL (0.2 ±0.1 mmol/L vs. 0.3 ±0.1 mmol/L, p=0.03) at the end of the basal period and equally suppressed during both interventions at the end of the HEC (p=0.7). EGP was unaffected by LAC compared with CTL at the end of the basal period (p=1.0) and suppressed at the end of the HEC during both interventions (p=1.0). M-value was unaffected by LAC compared with CTL (p=0.8).

Conclusion: Lactate inhibits palmitate lipolysis by 30 %, an effect which per se may improve insulin sensitivity. Hyperlactatemia did not affect EGP or insulin sensitivity, possibly because lactate intrinsically may induce insulin resistance.

Disclosure

M.G.B.Pedersen: None. N.Rittig: Research Support; ARLA. E.Søndergaard: None. L.C.Gormsen: None. N.Møller: Other Relationship; Aarhus University/Ketlace.
1665-P: Whole-Brain Activation Signatures of Weight-Lowering Drugs
Authors: DALBOEGE LOUISE S. , TOZZI MARCO , SALINAS CASPER G. , PORSGAARD TRINE , THORBEK DITTE D. , SKYTTE JACOB L. , ROOSTALU URMAS , HANSEN HENRIK H. , PERENS JOHANNA , HECKSHER-SØRENSEN JACOB
Published: June 2023

Background: The development of effective anti-obesity therapeutics relies heavily on the ability to target CNS signaling mechanisms critically involved in the homeostatic control of body weight. To get insight into neurocircuits recruited by anti-obesity drug treatment, the present study aimed to determine whole-brain activation signatures of six different weight-lowering drug classes with documented efficacy in humans.

Methods: Chow-fed mice received a single dose of lorcaserin (7 mg/kg, i.p.), rimonabant (10 mg/kg, i.p.), bromocriptine (D2 receptor agonist, 10 mg/kg, i.p.), sibutramine (10 mg/kg, p.o.), semaglutide (0.04 mg/kg, s.c.) or setmelanotide (4 mg/kg, s.c.). Brains were sampled two hours post-dosing, immunolabelled using c-Fos expression as a proxy for neuronal stimulation. Cleared whole-brains were imaged using light sheet fluorescence microscopy-deep learning pipeline enabling fully automated 3D mapping and quantitation of brain activation patterns at single-cell resolution.

Results: The whole-brain analysis comprised 308 atlas-defined mouse brain areas. To enable fast and efficient data mining, an open-access web-based 3D imaging data viewer (NeuroPedia.dk) was developed. All weight-lowering drugs demonstrated brain-wide responses with notable similarities in c-Fos expression signatures. Overlapping c-Fos responses were detected in discrete homeostatic and non-homeostatic feeding centres located in the dorsal vagal complex and hypothalamus with concurrent activation of several limbic structures as well as the dopaminergic system.

Conclusion: We pinpoint several overlapping brain activation signatures of various weight-lowering drugs. This shared feature suggests that weight-lowering drugs stimulate distinct homeostatic and non-homeostatic feeding centres. Future centrally acting anti-obesity compounds may be specifically designed to target key components of this neurocircuitry framework to provide more effective and sustained weight loss in obese patients.

Disclosure

L.S.Dalboege: Employee; Gubra aps. J.Hecksher-sørensen: Employee; Gubra ApS. M.Tozzi: None. C.G.Salinas: Employee; Gubra. T.Porsgaard: Employee; Gubra. D.D.Thorbek: Employee; Gubra APS. J.L.Skytte: Employee; Gubra ApS. U.Roostalu: Employee; Gubra. H.H.Hansen: None. J.Perens: Employee; Gubra ApS.
1669-P: The CCL22/CCR4 Axis Promotes Beige Adipocyte Formation by Recruiting Eosinophils
Authors: HU RUOCI , JIANG YUWEI
Published: June 2023

Beige adipocytes hold therapeutic promise for obese and diabetic patients. Thus, there is a clear basic and clinical need to understand the underlying mechanisms for beige adipocyte generation. Beige adipocytes can be generated from tissue-residing beige progenitors (APCs) in response to cold temperatures preferably around lymph nodes (LNs), suggesting that there are unique LN-derived signals controlling beige adipocyte generation. However, the importance of this unique anatomical location remains poorly understood. Here, we show that local LN removal greatly impairs cold-induced beiging, and this impairment can be restored by injecting M2 macrophages or macrophage-derived chemokine C-C motif ligand 22 (CCL22) into iWAT. Mechanistically, cold exposure increases the level of CCL22, which binds to its receptor C-C chemokine motif receptor 4 (CCR4). CCR4 then recruits eosinophils into iWAT and promotes beiging via FAK/p65 signaling. Furthermore, CCL22 levels are inversely correlated with body weight and fat mass, and elevated CCL22 levels prevent diet-induced obesity along with increased energy expenditure in mice and humans. Taken together, our findings reveal that the CCL22-CCR4 axis mediates signals from local LNs to control adipose beiging and energy expenditure, and that this mechanism provides a potential means to mitigate the development of obesity and its complications.

Disclosure

R.Hu: None. Y.Jiang: None.

Funding

National Institute of Diabetes and Digestive and Kidney Diseases (K01DK11177, R03DK127149, R01DK132398); Diabetes Research and Training Center (P30DK020595)
1673-P: Metabolic Outcomes and Changes in Innate Immunity Induced by Diesel Exhaust Particles Airway Exposure and High-Fat High-Sucrose Diet
Authors: HASEGAWA YUKA , OKAMURA TAKURO , HAMAGUCHI MASAHIDE , FUKUI MICHIAKI , TAKANO HIROHISA
Published: June 2023

Epidemiological studies have shown that exposure to diesel exhaust particles (DEP) is associated with metabolic diseases. We used mice with glucose intolerance and nonalcoholic fatty liver disease (NAFLD) caused by a high-fat, high-sucrose diet (HFHSD), which mimics a Western diet, to investigate the mechanism of metabolic diseases exacerbation via changes in innate immunity in the lungs by airway exposure to DEP. Six-week-old C57BL6/J male mice were fed HFHSD, and DEP was administered endotracheally once a week for eight weeks. Chronic exposure to DEP in HFHSD-fed mice increased inflammatory cells involved in innate immunity, such as type1 innate lymphoid cells (ILC1s), ILC2s, ILC3s, and M1 macrophages in the lungs and raised local inflammatory cytokine levels. This inflammation spread throughout the body, suggesting the association with the progression of NAFLD via increased inflammatory cells involved in innate immunity, such as ILC1s, ILC3s, M1 macrophages, and natural killer cells in the liver, and inflammatory cytokine levels in the liver which in turn exacerbated glucose intolerance. These findings contribute to a better understanding of the role of innate immunity in air pollution-related systemic diseases, especially metabolic diseases.

Disclosure

Y.Hasegawa: None. T.Okamura: Research Support; Yamada Bee Company, Inc. M.Hamaguchi: Research Support; Yamada Bee Company, Inc.. M.Fukui: None. H.Takano: None.

Funding

Japan Science and Technology Agency (JPMJCR19H3)
1675-P: Reproductive and Intergenerational Impacts of Metformin
Authors: OZTURK BERKCAN , FERRAZ-BANNITZ RAFAEL , EFTHYMIOU VISSARION , POULOS LINDSAY , NAVARRETE VALERIE , PATTI MARY-ELIZABETH
Published: June 2023

Recent data suggest that metformin can influence male reproductive health, directly or indirectly. Lastly, an epidemiologic cohort study demonstrated an association between preconceptional use of metformin in men and genital birthdefects in their offsprings. Given the need to test these associations in the absence of complex genetic and environmental factors in humans, we assessed the impact of metformin on both male reproductive health and health of offspring in C57/BL6J mice. Male mice age 8 weeks were treated with low fat (10% fat) or high fat (60% fat) diet to induce obesity; after two weeks, mice were randomized to continued dietary treatment, with or without metformin 350 mg/kg/day (n=8/group). After 12 weeks of treatment, metabolic status was assessed by glucose and insulin tolerance tests; as expected, metformin improved insulin sensitivity (21% improvement vs. HFD, p=0.008) despite no significant difference in body weight or glucose tolerance. To determine effect of male metformin treatment on reproductive success, HFD and HFD-MET males were bred with 6-8 week old females. Breeding was successful for 87.5% of HFD males, as compared with 37.5% for HFD-MET males (P=0.038). In both groups, insulin resistance (HOMA-IR) was strongly correlated with body weight (HFD: r=0.86, P=0.006; HFD-MET: r=0.92, P=0.001). However insulin resistance was inversely correlated with successful pregnancy rates only in HFD-MET mice (HFD: r=-0.3, P=0.21; HFD-MET: r=-0.68, P=0.04), suggesting that insulin sensitivity is a stronger and more significant determinant of fertility in metformin treated mice. Thus, we hypothesize that metformin may have dual impact on male reproductive health, with both beneficial increases in insulin sensitivity and potential adverse impact to reduce fertility. Additional studies are in progress to determine impact of male metformin treatment on hormonal and germ cell aspects of male reproductive health and offspring developmental phenotypes.

Disclosure

B.Ozturk: None. R.Ferraz-bannitz: None. V.Efthymiou: None. L.Poulos: None. V.Navarrete: None. M.Patti: Consultant; MBX Biosciences, AstraZeneca, Hanmi Pharm. Co., Ltd., Other Relationship; Fractyl Health, Inc.

Funding

National Institutes of Health (R01DK106193)
1677-P: Identification of a Chromosome 1 Substitution Line B6-Chr1YP1 as a Novel Obesity Model via Phenotyping Screening
Authors: QI HAO , YANG XUSHAN , ZHENG JIE , HOU YUMENG , CHEN ZHONG , LI ZHIYING , JU CUNXIANG , ZHAO JING , GAO XIANG
Published: June 2023

Obesity, a pandemic of modern world, is a chronic disease that seriously affects human health. The causes of obesity are complicated, including environmental factors and genetic factors. Due to the fact that traditional animal models cannot fully mimic obesity in human, new animal models are urgently needed for basic drug research on obesity. Previous studies have demonstrated that the genomic diversity of the wild mice chromosome 1 substitution lines was significantly different from that of laboratory mice, suggesting that it might be accompanied by phenotypic diversity. We firstly screened the obesity-related phenotype of chromosome 1 substitution lines and found that the male chow-diet-fed B6-Chr1YP1 mice showed severe obesity-related phenotypes in body weight, lipid metabolism and liver lesions. Compared with C57BL/6J mice, B6-Chr1YP1 showed much more severe obesity-related phenotypes when fed with high-fat-diet. Furthermore, we evaluated efficacy effects of Tirzepatide and MGL-3196 in B6-Chr1YP1 mice, and obesity-related phenotypes were significantly rescued. Taken together, male B6-Chr1YP1 mice could serve as a novel, polygenic interaction-based obesity and hyperlipidemia model. This study could provide a novel animal model for accurate clinical diagnosis and precise medicine of obesity and hyperlipidemia.

Disclosure

H.Qi: None. X.Yang: None. J.Zheng: None. Y.Hou: None. Z.Chen: None. Z.Li: None. C.Ju: None. J.Zhao: None. X.Gao: None.
1678-P: B6-Alms1-del Mice, a Metabolic Syndrome Animal Model, Shows Semaglutide Benefits on Obesity, Hyperglycemia, and NAFL
Authors: CHEN ZHONG , GAO MAOMAO , ZHAO XINYUE , LI ZHIYING , ZHAO JING , JU CUNXIANG , GAO XIANG
Published: June 2023

Metabolic syndrome is a cluster of conditions that occur together, increasing the risk of heart disease, stroke and type 2 diabetes. These conditions include obesity, hyperglycemia, hypertension, hyperlipidemia. Leptin and leptin receptor mutant mice, ob/ob and db/db, are two classic metabolic syndrome animal model. However, the transient hyperglycemia of ob/ob and severe hyperglycemia induced premature death of db/db limit the application of these two models. To fill the gap, GemPharmatech developed a metabolic disorder model based on the mutation of Alms1 gene in mice (B6-Alms1-del mice). B6-Alms1-del mice gradually developed obesity from 8 weeks old with chow diet, accompanied by hyperglycemia, glucose and insulin intolerance, dyslipidemia and impaired liver function. Moreover, B6-Alms1-del mice developed severe non alcoholic fatty liver spontaneously as early as 21 weeks old and no premature death was observed around 5~8 months of ages. As B6-Alms1-del mice copied major features of metabolic syndrome, we further tested whether B6-Alms1-del mice could response to the positive drug semaglutide, an agonist of GLP-1R. 16 weeks old B6-Alms1-del mice were treated with vehicle and semaglutide for 5 weeks, respectively. Our results indicate that semaglutide lead to benefit on metabolic syndrome, including body weight control, improvement in hyperglycemia, hyperlipidemia, liver injury and hepatic steatosis. In conclusion, we have established a metabolic syndrome animal model that develop clinically relevant metabolic phenotypes and overcome the limitation of ob/ob and db/db. Furthermore, B6-Alms1-del mice responds to the approval anti-obesity drug semaglutide, which provide a useful model to assess the efficacy of novel metabolic syndrome therapies.

Disclosure

Z.Chen: None. M.Gao: None. X.Zhao: None. Z.Li: None. J.Zhao: None. C.Ju: None. X.Gao: None.
1682-P: Identification of Peridroplet Mitochondria in White Adipocyte
Authors: FUWA MASAYUKI , ASANO MOTOCHIKA , MORI ICHIRO , MORITA HIROYUKI , KAJITA KAZUO , ISHIZUKA TATSUO
Published: June 2023

Mitochondria play various roles for biological maintenance in adipocytes. As for lipid metabolism, mitochondria have the opposite function of burning fatty acid by β-oxidation and supplying triglyceride (TAG) to lipid droplet. Recent study revealed that brown adipocytes (BA) contain cytoplasmic mitochondria (CM), which have high β-oxidation ability, and peridroplet mitochondria (PDM), which adhere lipid droplet, have high ability to generate ATP to synthesize and supply TAG to lipid droplet. On the other hand, Mitofusin 2 (Mfn2) and Mitoguardin 2 (MIGA2), and diacylglycerol acyltransferase 2 (DGAT2) are speculated to involved in interaction between mitochondria, endoplasmic reticulum and lipid droplet to promote TAG synthesis and expansion of lipid droplet. However, little is known about such mitochondrial fractions in white adipocytes (WA). In this study, we investigated whether WA isolated from mice adipose tissue may have mitochondria fractions corresponding to CM/PDM in BA. Cytoplasmic mitochondria and peridroplet mitochondria in WA (CMw/PDMw) were separated by centrifugation. Mitochondrial DNA, mitochondrial protein, incorporation of MitoTracker Red, and citrate synthase activity were detected in PDMw, as well as CMw. Electron microscopy showed larger size of mitochondria were observed in PDMw, than in CMw. Immunoblot analysis showed that Perilipin (Plin) 1 and Plin3 were detected in PDMw, but not in CMw. In addition, MIGA2 was detected in both CMw and PDMw, whereas Mfn2 and DGAT2 in PDMw. Immunoprecipitation study revealed that co-precipitation of Plin1/3 and MIGA2/Mfn2/DGAT2 was observed in the PDMw fraction. Our data indicated that mitochondria adhering lipid droplet was detected, which bind to Plin1/3. Moreover, the immunoprecipitation study suggested that mitochondria in the PDMw fraction may support TAG synthesis and expansion of lipid droplet. These results suggested that CMw and PDMw might play different roles in lipid metabolism in WA.

Disclosure

M.Fuwa: None. M.Asano: None. I.Mori: None. H.Morita: None. K.Kajita: None. T.Ishizuka: None.
1684-P: Transgene Integration-Induced Genomic Rearrangement in a Noncoding Region of Chromosome 1 Leads to Spontaneous Obesity and Type 2 Diabetes in Mice
Authors: WHITE DONNELL , WU JIAN , KANG SUNGWOOK , LAUTERBOECK LOTHAR , MOBASHERAN PARNIA , PALIARIN FRANCIELY , NGUYEN TINA , ELGAZZAZ MONA , MAIYA RAJANI , ALAHARI SURESH , LAZARTIGUES ERIC D. , YANG QINGLIN
Published: June 2023

Obesity is a critical risk factor for type 2 diabetes (T2D) and has become a global health issue. We found that a mouse line (C57/B6J) of Floxed-stop over expression of IF1 (ATPase Inhibitory Factor 1) (hereon called FEI) develops spontaneous obesity without induction of transgenic expression. Targeted-Locus-Amplification (TLA) analyses revealed a rearrangement in upstream sequences of the transgene integration site, and a duplication downstream in a non-coding region of chromosome 1. Male and female FEI mice show early dyslipidemia before weight gain at two months, reaching 50-60 grams at 6-8 months. Body composition revealed FEI mice have markedly increased fat mass and modestly increased lean mass, consistent with morphometric findings of substantially increased peripheral fat pads. FEI mice were hyperphagic. When subjected to pair-feeding, they reverted to comparable WT body weight levels, then gained weight again when fed ad libidum. Adult FEI mice maintain comparable physical activity levels to their WT counterparts, but indirect metabolic levels among FEI mice declined. These mice exhibited glucose and insulin tolerance at six weeks of age, as well as hyperglycemia, hyper-insulinemia, and hyper-leptinemia. Histology H&E staining revealed markedly enlarged adipocytes with crown-like structures on visceral white adipose tissue sections, and increased fat deposition in liver sections. RNAseq analyses from subcutaneous white adipose tissues of 5-month-old FEI mice demonstrate upregulation of adipogenic and inflammatory genes. Isolated FEI preadipocytes exhibited increased proliferation but impaired lipid deposition. RT-PCR revealed upregulation of inflammatory genes (IFI202b, TNF-α, and IL6). Together, we show FEI mice are a novel obese mouse model. Preclinical studies using this model may help yield insights into novel pathogenic mechanisms and effective treatments for obesity.

Disclosure

D.White: None. S.Alahari: None. E.D.Lazartigues: None. Q.Yang: None. J.Wu: None. S.Kang: None. L.Lauterboeck: None. P.Mobasheran: None. F.Paliarin: None. T.Nguyen: None. M.Elgazzaz: None. R.Maiya: None.

Funding

American Diabetes Association (1-17-IBS-184 to Q.Y.)
1685-P: Comparison of Obesity and Aging Signatures in Murine Adipose Tissue at Single-Cell Resolution
Authors: LEE ERIES , KANG DU-SEOCK , MYOUNG SUH JAE
Published: June 2023

Obesity and aging are major risk factors for various diseases and thus represent heavy socioeconomic burden to global healthcare. The two processes share similar, if not convergent, phenotypes, and increasing evidence suggests that one accelerates the other. Both obesity and aging are associated with insulin resistance, chronic low-grade inflammation and dysfunction of systemic energy homeostasis. However, there are many differences as well and the molecular mechanisms behind such similarities and differences remain unclear. Dysfunction of adipose tissue plays a significant role in both processes. Many studies have characterized adipose tissue of lean and obese mice at single-cell level, but obese and aged adipose tissue have not been directly compared side-by-side. Here, we compare single-cell transcriptomics of visceral (VAT) and subcutaneous (SAT) white adipose tissue in lean, diet-induced obesity, and aged conditions. In obese VAT, the relative frequency of macrophages increased, while that of lymphocytes decreased as expected. However, such myeloid shift was not observed in aged VAT. Metabolically, TREM2+ “lipid-associated macrophages”, which is known to increase in obese VAT, did not increase in aged VAT. Clustering of mesenchymal progenitor cells revealed depot-specific differences in previously reported cell subtypes. More cells were in a further differentiated, committed stage in VAT than in SAT. CD142+ CLEC11A+ “Aregs,” which were previously found to inhibit adipogenesis, increased in aged VAT and obese SAT. Interestingly, the frequency of endothelial cells in obese or aged state drastically decreased in SAT but not in VAT. Our comparative single-cell transcriptome atlas provides a detailed resource to analyze functional genomics behind obesity and aging.

Disclosure

E.Lee: None. D.Kang: None. J.Suh: None.
1688-P: Glucokinase Activator Triggers PERK-UPR Pathway in Diet-Induced Obese Mice via Inducing Hepatic Lipid Accumulation
Authors: CAI NAN , CHEN XUANRONG , LIU JIA , WEN ZHEYAO , WEN SIYING , ZENG WEN , LIN SHUO , CHEN YANMING , SHI GUOJUN , ZENG LONGYI
Published: June 2023

Background: To investigate the effect of glucokinase activation on glucose and lipid metabolism in diet-induced obese mice.

Methods: Mice fed with High-fat-diet (HFD) or control diet for 16 weeks were subjected to glucokinase activator (GKA) or vehicle treatment by gavage for 4 weeks. Glucose tolerance tests were performed to evaluate the glucose-lowering effect of GKA. Hepatic lipid accumulation was assessed by H&E, Oil-red’O staining, and transmission electronic microscopy. The underlying mechanism and subsequent effects of glucokinase activation-induced lipid accumulation was analyzed in liver. Protein levels of related genes were analyzed in mouse livers or AML12 cells.

Results: Glucokinase activation improved glucose tolerance and insulin sensitivity in obese mice. Moreover, increased liver weight and TG Content were found in GKA-treated obese mice. Significant hepatic lipid accumulation was observed by multiple assays. RNA sequencing analysis indicated the increased expression of lipogenesis genes and activated PERK-UPR pathway in the liver. Inhibition of the lipogenesis-related gene Acc reduced the lipid levels caused by GKA treatment and alleviated PERK-UPR pathway in AML12 cell line.

Conclusions: Glucokinase activation improved glucose tolerance while induced hepatic lipid accumulation through increased lipogenesis, which subsequently triggered PERK-UPR signaling pathway.

Disclosure

N.Cai: None. L.Zeng: None. X.Chen: None. J.Liu: None. Z.Wen: None. S.Wen: None. W.Zeng: None. S.Lin: None. Y.Chen: None. G.Shi: None.

Funding

National Natural Science Foundation of China (81770826, 82070811); National Key R&D Program of China (2017YFA0105803); Key Area R&D Program of Guangdong Province (2019B020227003); Sci-Tech Research Development Program of Guangzhou City (202201020497); Natural Science Foundation of Guangdong Province (2018B030311012)
1690-P: Adipose Tissue Dectin-1 Upregulation in Hyperglycemic Obesity Involves TNF-α/NF-kB Mediated Signaling
Authors: AL MADHOUN ASHRAF , HADDAD DANIA , KOCHUMON SHIHAB P. , ALRASHED FATEMA , THOMAS REEBY S. , MIRANDA LAVINA P. , SINDHU SARDAR T.A.K. , AHMAD RASHEED , ALMULLA FAHD
Published: June 2023

Dectin-1 is a pathogen recognition receptor as well as an innate immune response modulator; its function in metabolic disorders is yet unclear. Previously, we identified dectin-1 as a biomarker of metabolic inflammation in obesity. In this study, we sought to identify potential signaling pathways that could modify the expression of the dectin-1 gene and assess the expression of dectin-1 in the adipose tissue (AT) of obese patients based on their diabetic status. The study cohort included 95 obese individuals split into two groups: prediabetics with moderate glycemia (Hb1Ac 6.5%, n = 49) and diabetics with hyperglycemia (Hb1Ac 6.5%, n = 46). Dectin-1 expression was assessed using immunohistochemistry. Gene expression and inflammatory markers were determined via qRT-PCR. We found a significant positive correlation between dectin-1 expression and HbA1C levels in AT isolated from obese individuals with HbA1C levels of 6.5% or higher. Dectin-1 gene expression was significantly correlated with several inflammatory markers; however, glycemic-dependent associations were also observed. Dectin-1 and TNF-α were found to be significantly correlated in AT from individuals with Hb1Ac 6.5%, indicating a possible mechanism of gene regulation between these two factors. As a result, we investigated the observed dectin-1/TNF-α crosstalk using in vitro cell culture and animal studies. Unlike wild-type animals, mice lacking TNF-α exhibited reduced levels of dectin-1 gene and protein expression in their AT, which were restored by injecting exogenous TNF-α. ChIP studies showed that TNF-α induced dectin-1 gene transcription by mediating NF-kB binding to newly identified regulatory elements located in the dectin-1 proximal regulatory region. The interplay between dectin-1 and TNF-α signaling pathways is intriguing and has the potential to be a therapeutic target in obesity and diabetes. Furthermore, dectin-1 could be a potential marker for the onset of hyperglycemia and diabetes.

Disclosure

A.Al madhoun: None. D.Haddad: None. S.P.Kochumon: None. F.Alrashed: None. R.S.Thomas: None. L.P.Miranda: None. S.T.K.Sindhu: None. R.Ahmad: None. F.Almulla: None.
1691-P: Weight Status, Longitudinal Weight Change, and Weight Loss Treatment Utilization among Primary Care Patients with Obesity
Authors: GRIAUZDE DINA H. , RICHARDSON CAROLINE R. , LEE JOYCE M. , HENDERSON JAMES , EHLERS ANNE P.
Published: June 2023

Background: Effective weight management treatments (WMTs) include nutrition counseling, very low-calorie (VLC) meal replacement, anti-obesity medications (AOMs), and bariatric surgery. Little is known about how these WMTs influence weight change among individual primary care patients and populations.

Methods: This was a retrospective cohort study using medical record data from one academic health system. Participants were adults with primary care between October 2015 and March 2020. We used serial cross-sections to examine obesity prevalence and WMT use. We used a multistate model to investigate weight trajectories for patients with obesity and no WMT use prior to baseline. This is a time-to-event model with events representing transitions between 5 successive categories of weight change relative to baseline (i.e., ≥10% weight loss, 5-10% weight loss, baseline weight +/-5%, 5-10% weight gain, or ≥10% weight gain). The primary exposures were WMTs; controls were baseline age, BMI, and prior year primary care. Patients with WMT use were propensity matched 1:1 to controls. The primary outcome was the model-based probability of ≥5% weight loss at 1 year.

Results: Among primary patients, the prevalence of obesity increased from 39.2% in 2017 to 40.7% in 2019 (n=138,632); WMT use increased from 2.8% to 8.9% (difference: 6.1%, 95% CI: 5.8-6.4%). In the multistate model (n=10,296), the one-year probability of ≥5% weight loss among patients without WMT exposure was 15.5% [95% CI: 14.8-16.1%]. In contrast, ≥5% weight loss was more likely for patients with year-long exposures to any WMT (nutrition counseling: 23.4%, 95% CI: 21.5-25.3%; VLC meal replacement: 56.4%, 95% CI: 48.7-62.8%; AOMs: 27.8%, 95% CI: 25.1-30.5%; bariatric surgery: 94.4%, 95% CI: 91.1-96.4%).

Conclusions: Use of all WMTs increased the probability of achieving ≥5% weight loss at the individual-patient level but underutilization limits their ability to reduce weight at the population-level.

Disclosure

D.H.Griauzde: None. C.R.Richardson: Other Relationship; Annals of Family Medicine, JMIR Diabetes, Research Support; Dexcom, Inc., Blue Cross Blue Shield of Michigan, Neilson Foundation. J.M.Lee: Advisory Panel; GoodRx, Consultant; Tandem Diabetes Care, Inc. J.Henderson: None. A.P.Ehlers: None.

Funding

National Institute of Diabetes and Digestive and Kidney Diseases (K23DK123416)
1695-P: On the Temporal Relationship between Telomere Length and Adiposity Levels
Authors: HSUEH WEN-CHI , LIN JUE , HANSON ROBERT L.
Published: June 2023

Short telomere length (TL) has been found to be associated with obesity related traits. However, most studies were cross-sectional in nature and conducted in adult subjects only. We aimed at examining the temporal relationship between telomere length and adiposity levels, measured by BMI, in both adults and youth. Our samples were selected from a population-based prospective cohort study in Southwest Amerindians who are at high risk for metabolic disorders. We obtained TL measures at 2 time points >10 years apart for 805 individuals who had concomitant BMI measures, and designated these as baseline and follow-up (f/u) exams; 1/3 were male and 1/3 were aged <18 years at baseline The means (range) of TL (measured in SD units), age at baseline, BMI at baseline, and the f/u period were 4.8±1.0 (2.2-8.5) SD units, 24.6±10.3 (5-63) years, 31.7±7.9 (15-63) kg/m2, and 13.6±1.7 years (11-18.4 years), respectively. No significant sex difference was observed, and 48% of subjects had longer TL at f/u. TL at baseline in youth was 14% longer than that of adults on average (p<E-4). There was no association between BMI at baseline and change in TL at f/u (β=-0.0036±0.0048 SD unit/kg*m-2, p=0.45 in the entire sample, similar results observed in adults or youth only), adjusted for effects of age, sex, ancestry, assay batches and the length of f/u. Longer TL at baseline had a modest association with lower change in BMI at f/u in youth (β=-2.89±1.47 kg*m-2/SD unit, p=0.050) but not in adults (β=0.96±0.96, p=0.32). In conclusion, our findings suggest that TL may be a risk factor for obesity, especially in younger people, but not the other way around. A larger study is underway to provide more robust estimates.

Disclosure

W.Hsueh: None. J.Lin: None. R.L.Hanson: None.

Funding

National Institutes of Health
1696-P: Changes in Clinical and Metabolic Parameters Related to NAFLD in Obese Subjects Who Underwent Laparoscopic Sleeve Gastrectomy
Authors: HO LEE DAE , BYUNG PARK IE
Published: June 2023

More research is needed on the effect of laparoscopic sleeve gastrectomy (LSG) on NAFLD and related parameters. A total of 51 morbidly obese subjects with NAFLD who would undergo LSG were included, with liver biopsy performed during LSG in 46 patients. Various clinical parameters and blood biomarkers related to NAFLD were measured before and 6 months after LSG, which included fat content in the liver (LFC) and pancreas (PFC) by MRI-PDFF, liver stiffness measurement by MR elastography (MRE-LSM), and others. After LSG, there was a significant decrease in body weight and LFC: 102.0 ± 15.3 vs. 76.3 ± 14.3 kg and 19.4 ± 9.1% vs. 5.7 ± 2.9%, respectively, p <0.001 each. And, body fat on DXA, PFC, and visceral fat area measured by MRI, and, fasting plasma levels of total GIP and glucagon decreased significantly after bariatric surgery, with no change in total GLP-1 and peptide YY levels. Notably, there was a marked increase in plasma levels of FGF21 (547.1 ± 890.5 pg/ml vs. 1085 pg/ml ± 1883.75, p<0.05) and oxyntomodulin (436.0 ± 351.4 pg/ml vs. 1533.6 ± 624.4 pg/ml, p<0.001). These changes were accompanied by a significant reduction of NASH blood biomarkers such AKR1B10, cytokeratin 18, and complement C3. And, MRE-LSM, a marker of liver fibrosis, decreased significantly after LSG (3.1 ± 0.8 kPa vs. 2.7 ± 0.1 kPa, p <0.01), but enhanced liver fibrosis score did not. Only 15.2% of patients with biopsy-proven NAFLD showed more than 25% decrease in MRE-LSM, and baseline fibrosis degree was only the predictor of this decrease in MRE-LSM after LSG. Our results show that in patients with morbid obesity, marked reduction of body weight and LFC and a significant increase in plasma FGF21 and oxyntomodulin levels were observed 6 months after LSG, with the reduction of several markers of NASH. However, a meaningful MRE-LSM improvement was observed only in a small proportion of patients, which warrants long-term follow-up of patients with NASH/fibrosis who underwent LSG.

Disclosure

D.Lee: None. I.Park: None.

Funding

National Research Foundation of Korea (2021R1A5A2030333, 2019R1I1A2A02062305)
1699-P: Association between Insulin Resistance and Myosteatosis Measured by Abdominal Computed Tomography
Authors: JIN KIM MYUNG , KYUNG CHO YUN , NA JUNG HAN , HEE JUNG CHANG , CHUL WON JONG , PARK JOONG-YEOL , KIM HONG-KYU , JE LEE WOO
Published: June 2023

Background: Ectopic fat deposition in skeletal muscle, termed myosteatosis, is a key factor in developing insulin resistance. We aimed to evaluate the association between insulin resistance and myosteatosis in a large Asian population.

Methods: A total of 18,251 participants who had abdominal computed tomography from 2012 to 2013 were included. The total abdominal muscle area (TAMA) at the L3 vertebral level was segmented into normal-attenuation muscle area (NAMA), low-attenuation muscle area (LAMA), and intramuscular adipose tissue (IMAT). The ratios of NAMA/BMI, LAMA/BMI, and NAMA/TAMA were used as myosteatosis indices.

Results: NAMA/BMI and NAMA/TAMA index showed downward trends with higher HOMA-IR levels, while LAMA/BMI showed upward trends. As HOMA-IR levels increased, the odds ratios (ORs) of the highest quartile of NAMA/BMI and NAMA/TAMA index decreased and that of LAMA/BMI increased. Compared with the lowest HOMA-IR group, the adjusted ORs (95% confidence intervals [CI]) in the highest HOMA-IR group for the lowest NAMA/TAMA quartile were 0.414 (0.364-0.471) in males and 0.464 (0.384-0.562) in females. HOMA-IR showed a negative correlation with NAMA/TAMA index (r = -0.211 for men and r = -0.214 for women, p <0.001 for both).

Conclusion: A higher HOMA-IR level was significantly associated with a high risk of myosteatosis.

Disclosure

M.Kim: None. Y.Cho: None. H.Jung: None. C.Jung: None. J.Won: None. J.Park: None. H.Kim: None. W.Lee: None.