Endocrine System Diseases Commons^™

The Effect Of A Low-Glycemic Index Diet On Polycystic Ovary Syndrome Symptoms Among University-Aged Women, Angelika A. Gonzalez, Annalise M. Sankar, Noelle D. Nguyen

Department of Nutrition Student Projects

Polycystic Ovary Syndrome is an endocrine disorder among women of reproductive age and is associated with insulin resistance, menstrual irregularities, hyperandrogenism, and metabolic dysfunction. Dietary modifications targeting glycemic response have emerged as a nonpharmacologic approach for PCOS management. However, long-term randomized controlled trials targeting young adult populations remain limited.

The purpose of this study is to evaluate long-term effects of adherence to a low-glycemic index diet on the frequency and severity of PCOS symptoms among female college students ages 18-22. This 12-month randomized controlled trial will recruit participants meeting the Rotterdam criteria from university health clinics. Participants will be randomly …

Rab5c Increases Endothelial Release Of Vwf By Regulating Vesicle Trafficking, Paula Reventun, Pablo Toledano-Sanz, Maria Delgado-Marin, Maria Viskadourou, D Brian Foster, Paul S De Vries, Maria Sabater-Lleal, Nunzio Alcharani, Claudia Gonzalez-Cucharero, William O Osburn, Alanna C Morrison, Alisa S Wolberg, Nicholas L Smith, Marios Arvanitis, Charles J Lowenstein

Faculty, Staff and Student Publications

Background: Abnormal levels of VWF (von Willebrand Factor) are a risk factor for venous thromboembolism (VTE) and bleeding. Genome-wide association studies for VWF have identified novel candidate genes that may regulate VWF levels in humans, including RAB5C (RAS-associated protein RAB5C). We hypothesized that RAB5C regulates VWF release from endothelial cells.

Methods: We studied the effect of RAB5C on vesicle trafficking in human endothelial cells. We performed CRISPR (clustered regularly interspaced short palindromic repeats) interference targeting 2 genetic variants linked to altered VWF levels and evaluated RAB5C expression by reverse transcription-quantitative polymerase chain reaction. We silenced RAB5C or overexpressed RAB5C wild-type, …

Dna Methylation Markers Of Insulin Resistance Surrogate Measures In The Atherosclerosis Risk In Communities (Aric) Study, Jeewoen Shin, Jan Bressler, Megan L Grove, Michael Brown, Elizabeth Selvin, James S Pankow, Myriam Fornage, Alanna C Morrison, Chloé Sarnowski

Faculty, Staff and Student Publications

Insulin resistance (IR) is a risk factor for cardiovascular diseases and type 2 diabetes. Associations between DNA methylation (DNAm) and IR have been less studied in African ancestry (AA) populations than those of European ancestry (EA). We aimed to identify associations between whole blood DNAm and IR in up to 1,811 AA and 964 EA participants from the Atherosclerosis Risk in Communities (ARIC) study. We quantified IR using three surrogate measures: the homeostasis model assessment of insulin resistance (HOMA-IR), the triglyceride-glucose index (TyG), and the triglyceride glucose-body mass index (TyG-BMI). We used ancestry-stratified linear regression models to conduct epigenome-wide association …

The Microrna Mir-30a Blocks Adipose Tissue Fibrosis Accumulation In Obesity, Pradip K Saha, Robert Sharp, Aaron R Cox, Rabie Habib, Michael J Bolt, Jessica B Felix, Claudia E Ramirez Bustamante, Xin Li, Sung Yun Jung, Kang Ho Kim, Kai Sun, Huaizhu Wu, Samuel Klein, Sean M Hartig

Faculty, Staff and Student Publications

White adipose tissue (WAT) fibrosis occurring in obesity contributes to the inflammatory and metabolic comorbidities of insulin resistance and type 2 diabetes, yet the mechanisms involved remain poorly understood. Here, we report a role for the broadly conserved miRNA miR-30a as a regulator of WAT fibrosis and systemic glucose metabolism. Mice modified to express miR-30a at elevated levels in adipose tissues maintain insulin sensitivity coupled with reduced fatty liver disease when fed a high-fat diet. These effects were attributable to cell-autonomous functions of miR-30a that potently increase expression of adipocyte-specific genes. Proteomic screening revealed miR-30a limits profibrotic programs in subcutaneous …

The Combined Effect Of High-Intensity Interval Training And Time-Restricted Feeding On The Akt-Igf-1-Mtor Signaling Pathway In The Muscle Tissue Of Type 2 Diabetic Rats, Motahareh Mohebinejad, Fatemeh Kazeminasab, Mahtab Ghanbari Rad, Reza Bagheri, Mazdak Razi, Darryn Willoughby, Fred Dutheil

Faculty, Staff and Students Publications

Background/Objectives: High-intensity interval training (HIIT) and time-restricted feeding (TRF) have shown potential in enhancing glucose metabolism, increasing insulin sensitivity, and promoting muscle health. This study investigates the combined effects of HIIT and TRF on the AKT-IGF-1-mTOR signaling pathway in the muscle tissue of type 2 diabetic (T2D) rats.

Methods: 42 male Wistar rats (4-5 weeks of age) were included in the study. The animals were randomly divided into two groups: 1. Standard diet (SD) non-diabetic (n = 7) and 2. High-fat diet (HFD n = 35) for 4 weeks. T2D was induced by intraperitoneal injection (IP) of streptozotocin (STZ) …

The Role Of The Triglyceride-Glucose Index As A Biomarker Of Cardio-Metabolic Syndromes, Verena Gounden, Sridevi Devaraj, Ishwarlal Jialal

Faculty, Staff and Students Publications

BACKGROUND: The Triglyceride-glucose (TyG) index represents a simple, cost-effective, and valid proxy for insulin resistance. This surrogate marker has also been proposed as a predictor of metabolic and cardiovascular disease (CVD). In this descriptive review, we aimed to assess the utility of the TyG index as a predictive biomarker of cardiometabolic diseases.

METHODS: A search was conducted in PubMed, and Web of Science to identify cross-sectional and more importantly prospective studies examining the use of the TyG index as a predictive biomarker. The following terms were utilized in addition to the TyG index: "insulin resistance", "metabolic syndrome", "diabetes"; "cardiovascular diseases". …

Deletion Of Mipep In Adipocytes Protects Against Obesity And Insulin Resistance By Boosting Muscle Metabolism, Alexis Diaz-Vegas, Kristen C Cooke, Harry B Cutler, Belinda Yau, Stewart W C Masson, Dylan Harney, Oliver K Fuller, Meg Potter, Søren Madsen, Niamh R Craw, Yiju Zhang, Cesar L Moreno, Melkam A Kebede, G Gregory Neely, Jacqueline Stöckli, James G Burchfield, David E James

Faculty, Staff and Students Publications

Mitochondria facilitate thousands of biochemical reactions, covering a broad spectrum of anabolic and catabolic processes. Here we demonstrate that the adipocyte mitochondrial proteome is markedly altered across multiple models of insulin resistance and reveal a consistent decrease in the level of the mitochondrial processing peptidase miPEP.

OBJECTIVE: To determine the role of miPEP in insulin resistance.

METHODS: To experimentally test this observation, we generated adipocyte-specific miPEP knockout mice to interrogate its role in the aetiology of insulin resistance.

RESULTS: We observed a strong phenotype characterised by enhanced insulin sensitivity and reduced adiposity, despite normal food intake and physical activity. Strikingly, …

The Impact Of Eggs On Inflammatory And Immune Profiles In Women With Polycystic Ovary Syndrome (Pcos), Clara Martin

Honors Scholar Theses

Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder affecting approximately 5-15% of women of reproductive age. Characterized by symptoms such as hyperandrogenism, ovulatory dysfunction, and insulin resistance, PCOS is also linked with significant health complications including metabolic syndrome, cardiovascular diseases, and type 2 diabetes. Recent studies highlight the critical role of immune dysfunction and chronic inflammation in exacerbating PCOS pathology, suggesting that managing these immune responses could alleviate the broader health impacts of the disorder.

Nutritional interventions, particularly those targeting immune and inflammatory pathways, have emerged as promising strategies for managing PCOS. Among various dietary components, the intake of …

An Estrogen Receptor Α-Derived Peptide Improves Glucose Homeostasis During Obesity, Wanbao Yang, Wen Jiang, Wang Liao, Hui Yan, Weiqi Ai, Quan Pan, Wesley A Brashear, Yong Xu, Ling He, Shaodong Guo

Faculty, Staff and Students Publications

Estrogen receptor α (ERα) plays a crucial role in regulating glucose and energy homeostasis during type 2 diabetes mellitus (T2DM). However, the underlying mechanisms remain incompletely understood. Here we find a ligand-independent effect of ERα on the regulation of glucose homeostasis. Deficiency of ERα in the liver impairs glucose homeostasis in male, female, and ovariectomized (OVX) female mice. Mechanistic studies reveal that ERα promotes hepatic insulin sensitivity by suppressing ubiquitination-induced IRS1 degradation. The ERα 1-280 domain mediates the ligand-independent effect of ERα on insulin sensitivity. Furthermore, we identify a peptide based on ERα 1-280 domain and find that ERα-derived peptide …

Insulin Resistance And Insulin Handling In Chronic Kidney Disease, Vishnu P Parvathareddy, Jiao Wu, Sandhya S Thomas

Faculty, Staff and Students Publications

Insulin regulates energy metabolism involving multiple organ systems. Insulin resistance (IR) occurs when organs exhibit reduced insulin sensitivity, leading to difficulties in maintaining glucose homeostasis. IR ensures decades prior to development of overt diabetes and can cause silent metabolic derangements. IR is typically seen very early in the course of chronic kidney disease (CKD) and is evident even when the estimated glomerular filtration rate (eGFR) is within the normal range and IR persists at various stages of kidney disease. In this article, we will discuss insulin handling by the kidneys, mechanisms responsible for IR in CKD, measurements and management of …

Sex Hormone-Binding Globulin (Shbg) Mitigates Er Stress And Improves Viability And Insulin Sensitivity In Adipose-Derived Mesenchymal Stem Cells (Asc) Of Equine Metabolic Syndrome (Ems)-Affected Horses, Nabila Bourebaba, Mateusz Sikora, Badr Qasem, Lynda Bourebaba, Krzysztof Marycz

Faculty, Staff and Student Publications

BACKGROUND: Equine metabolic syndrome (EMS), which encompasses insulin resistance, low-grade inflammation and predisposition to laminitis is a critical endocrine disorder among the most prevalent conditions affecting horses from different breeds. According to the most recent research, low human sex hormone-binding globulin (SHBG) serum levels correlate with an increased risk of obesity, insulin resistance and diabetes, and may contribute to overall metabolic dysregulations. This study aimed to test whether exogenous SHBG could protect EMS affected adipose-derived stromal stem cells (EqASC

METHODS: EqASC

RESULTS: Obtained data demonstrated that exogenous SHBG treatment significantly promoted ASCs cells proliferation, cell cycle and survival with reduced …

Long-Term Maternal Metabolic And Cardiovascular Phenotypes After A Pregnancy Complicated By Mild Gestational Diabetes Mellitus Or Obesity, Ashley N Battarbee, Lisa Mele, Mark B Landon, Michael W Varner, Brian M Casey, Uma M Reddy, Ronald J Wapner, Dwight J Rouse, John M Thorp, Edward K Chien, George Saade, Beth A Plunkett, Sean C Blackwell

Faculty, Staff and Student Publications

Objective:

To evaluate the association of mild gestational diabetes (GDM) and obesity with metabolic and cardiovascular markers 5-10 years after pregnancy.

Study Design:

This was a secondary analysis of 5-10 year follow-up study of a mild GDM treatment trial and concurrent observational cohort of participants ineligible for the trial with abnormal 1-hour glucose challenge test only. Participants with 2-hour glucose tolerance test at follow-up were included. The primary exposures were mild GDM and obesity. The outcomes were insulinogenic index (IGI), 1/HOMA-IR, and cardiovascular markers VEGF, VCAM-1, CD40L, GDF-15, and ST-2. Multivariable linear regression estimated the association of GDM and obesity …

Supplementing Glycine And N-Acetylcysteine (Glynac) In Older Adults Improves Glutathione Deficiency, Oxidative Stress, Mitochondrial Dysfunction, Inflammation, Physical Function, And Aging Hallmarks: A Randomized Clinical Trial, Premranjan Kumar, Chun Liu, James Suliburk, Jean W Hsu, Raja Muthupillai, Farook Jahoor, Charles G Minard, George E Taffet, Rajagopal V Sekhar

Faculty, Staff and Students Publications

BACKGROUND: Elevated oxidative stress (OxS), mitochondrial dysfunction, and hallmarks of aging are identified as key contributors to aging, but improving/reversing these defects in older adults (OA) is challenging. In prior studies, we identified that deficiency of the intracellular antioxidant glutathione (GSH) could play a role and reported that supplementing GlyNAC (combination of glycine and N-acetylcysteine [NAC]) in aged mice improved GSH deficiency, OxS, mitochondrial fatty-acid oxidation (MFO), and insulin resistance (IR). To test whether GlyNAC supplementation in OA could improve GSH deficiency, OxS, mitochondrial dysfunction, IR, physical function, and aging hallmarks, we conducted a placebo-controlled randomized clinical trial.

METHODS: Twenty-four …

Supplementing Glycine And N-Acetylcysteine (Glynac) In Older Adults Improves Glutathione Deficiency, Oxidative Stress, Mitochondrial Dysfunction, Inflammation, Physical Function, And Aging Hallmarks: A Randomized Clinical Trial, Premranjan Kumar, Chun Liu, James Suliburk, Jean W Hsu, Raja Muthupillai, Farook Jahoor, Charles G Minard, George E Taffet, Rajagopal V Sekhar

Faculty, Staff and Students Publications

BACKGROUND: Elevated oxidative stress (OxS), mitochondrial dysfunction, and hallmarks of aging are identified as key contributors to aging, but improving/reversing these defects in older adults (OA) is challenging. In prior studies, we identified that deficiency of the intracellular antioxidant glutathione (GSH) could play a role and reported that supplementing GlyNAC (combination of glycine and N-acetylcysteine [NAC]) in aged mice improved GSH deficiency, OxS, mitochondrial fatty-acid oxidation (MFO), and insulin resistance (IR). To test whether GlyNAC supplementation in OA could improve GSH deficiency, OxS, mitochondrial dysfunction, IR, physical function, and aging hallmarks, we conducted a placebo-controlled randomized clinical trial.

METHODS: Twenty-four …

Butyrate-Producing Bacteria And Insulin Homeostasis: The Microbiome And Insulin Longitudinal Evaluation Study (Miles), Jinrui Cui, Gautam Ramesh, Martin Wu, Elizabeth T Jensen, Osa Crago, Alain G Bertoni, Chunxu Gao, Kristi L Hoffman, Patricia A Sheridan, Kari E Wong, Alexis C Wood, Yii-Der I Chen, Jerome I Rotter, Joseph F Petrosino, Stephen S Rich, Mark O Goodarzi

Faculty, Staff and Students Publications

Gut microbiome studies have documented depletion of butyrate-producing taxa in type 2 diabetes. We analyzed associations between butyrate-producing taxa and detailed measures of insulin homeostasis, whose dysfunction underlies diabetes in 224 non-Hispanic Whites and 129 African Americans, all of whom completed an oral glucose tolerance test. Stool microbiome was assessed by whole-metagenome shotgun sequencing with taxonomic profiling. We examined associations among 36 butyrate-producing taxa (n = 7 genera and 29 species) and insulin sensitivity, insulin secretion, disposition index, insulin clearance, and prevalence of dysglycemia (prediabetes plus diabetes, 46% of cohort), adjusting for age, sex, BMI, and race. The genus Coprococcus …

Adiposity, Insulin Resistance, Cardiorespiratory Fitness, And Bone Health In Hispanic Children, Reem S Shawar, Maurice Puyau, Roman Shypailo, Salma Musaad, Nancy F Butte, Fida Bacha

Faculty, Staff and Students Publications

CONTEXT: Childhood obesity disproportionately affects Hispanic youth. The skeletal system appears to be a target organ of the adverse effects of obesity. Yet, the relationship between adiposity and bone health in youth and the modulating factors are not well understood.

OBJECTIVE: This work aims to examine the relationship between adiposity, insulin resistance (IR), cardiorespiratory fitness (CRF), and bone mass in Hispanic youth.

METHODS: A total of 951 Hispanic youth (50% male), aged 4 to 19 years, participated in this cross-sectional design study from the Viva La Familia Study at Children's Nutrition Research Center. Bone mineral content (BMC) and density (BMD), …

Calcium/Calmodulin-Dependent Protein Kinase Kinase 2 Regulates Hepatic Fuel Metabolism, Brittany A Stork, Adam Dean, Andrea R Ortiz, Pradip Saha, Nagireddy Putluri, Maricarmen D Planas-Silva, Iqbal Mahmud, Kimal Rajapakshe, Cristian Coarfa, Stefan Knapp, Philip L Lorenzi, Bruce E Kemp, Benjamin E Turk, John W Scott, Anthony R Means, Brian York

Faculty, Staff and Students Publications

OBJECTIVE: The liver is the primary internal metabolic organ that coordinates whole body energy homeostasis in response to feeding and fasting. Genetic ablation or pharmacological inhibition of calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2) has been shown to significantly improve hepatic health and peripheral insulin sensitivity upon overnutrition with high fat diet. However, the precise molecular underpinnings that explain this metabolic protection have remained largely undefined.

METHODS: To characterize the role of CaMKK2 in hepatic metabolism, we developed and challenged liver-specific CaMKK2 knockout (CaMKK2

RESULTS: Consistent with previous findings, we show that hepatic CaMKK2 ablation significantly improves indices of peripheral insulin …

Effect Of A Glp-1 Mimetic On The Insulin Response To Oral Sugar Testing In Horses, Darko Stefanovski, Mary A Robinson, Andrew Van Eps

Faculty, Staff and Student Publications

BACKGROUND: Insulin dysregulation (ID) is the most important risk factor for the development of laminitis in horses and therapies to control it are needed.

HYPOTHESIS/OBJECTIVES: To assess the effects of a single dose of the synthetic GLP-1 analog exenatide on postprandial insulin dynamics. We hypothesized that exenatide would improve insulin sensitivity and lower postprandial blood insulin concentrations.

STUDY DESIGN: Randomized, crossover, experimental study.

ANIMALS: Six horses (3 mares, 3 geldings; 2 with normal insulin regulation [NIR] and 4 with mild ID).

METHODS: Horses completed both study arms: subcutaneous administration of exenatide (or no treatment) 30 min before an oral sugar …

Regulation Of Age-Associated Insulin Resistance By Mt1-Mmp-Mediated Cleavage Of Insulin Receptor, Xuanming Guo, Pallavi Asthana, Susma Gurung, Shuo Zhang, Sheung Kin Ken Wong, Samane Fallah, Chi Fung Willis Chow, Sijia Che, Lixiang Zhai, Zening Wang, Xin Ge, Zhixin Jiang, Jiayan Wu, Yijing Zhang, Xiaoyu Wu, Keyang Xu, Cheng Yuan Lin, Hiu Yee Kwan, Aiping Lyu, Zhongjun Zhou, Zhao-Xiang Bian, Hoi Leong Xavier Wong

Faculty, Staff and Student Publications

Insulin sensitivity progressively declines with age. Currently, the mechanism underlying age-associated insulin resistance remains unknown. Here, we identify membrane-bound matrix metalloproteinase 14 (MT1-MMP/MMP14) as a central regulator of insulin sensitivity during ageing. Ageing promotes MMP14 activation in insulin-sensitive tissues, which cleaves Insulin Receptor to suppress insulin signaling. MT1-MMP inhibition restores Insulin Receptor expression, improving insulin sensitivity in aged mice. The cleavage of Insulin Receptor by MT1-MMP also contributes to obesity-induced insulin resistance and inhibition of MT1-MMP activities normalizes metabolic dysfunctions in diabetic mouse models. Conversely, overexpression of MT1-MMP in the liver reduces the level of Insulin Receptor, impairing hepatic insulin …

Berberine Remodels Adipose Tissue To Attenuate Metabolic Disorders By Activating Sirtuin 3, Dan Li, Chao Yang, Jian-Zhong Zhu, Eduardo Lopez, Tian Zhang, Qiang Tong, Cheng Peng, Li-Gen Lin

Faculty, Staff and Students Publications

Adipose tissue remodelling is considered a critical pathophysiological hallmark of obesity and related metabolic diseases. Berberine (BBR), a natural isoquinoline alkaloid, has potent anti-hyperlipidaemic and anti-hyperglycaemic effects. This study aimed to explore the role of BBR in modulating adipose tissue remodelling and the underlying mechanisms. BBR protected high fat diet (HFD)-fed mice against adiposity, insulin resistance and hyperlipidemia. BBR alleviated adipose tissue inflammation and fibrosis by inhibiting macrophage infiltration, pro-inflammatory macrophage polarization and the abnormal deposition of extracellular matrix, and the effect was mediated by BBR directly binding and activating the deacetylase Sirtuin 3 (SIRT3) and suppressing the activation of …

Isoform-Specific Functions Of Pparγ In Gene Regulation And Metabolism, Wenxiang Hu, Chunjie Jiang, Mindy Kim, Yang Xiao, Hannah J Richter, Dongyin Guan, Kun Zhu, Brianna M Krusen, Arielle N Roberts, Jessica Miller, David J Steger, Mitchell A Lazar

Faculty, Staff and Students Publications

Peroxisome proliferator-activated receptor γ (PPARγ) is a nuclear receptor that is a vital regulator of adipogenesis, insulin sensitivity, and lipid metabolism. Activation of PPARγ by antidiabetic thiazolidinediones (TZD) reverses insulin resistance but also leads to weight gain that limits the use of these drugs. There are two main PPARγ isoforms, but the specific functions of each are not established. Here we generated mouse lines in which endogenous PPARγ1 and PPARγ2 were epitope-tagged to interrogate isoform-specific genomic binding, and mice deficient in either PPARγ1 or PPARγ2 to assess isoform-specific gene regulation. Strikingly, although PPARγ1 and PPARγ2 contain identical DNA binding domains, …

Plasma Diaphanous Related Formin 1 Levels Are Associated With Altered Glucose Metabolism And Insulin Resistance In Patients With Polycystic Ovary Syndrome: A Case Control Study, Xing Li, Mingyu Liao, Jiaqing Shao, Weixin Li, Liu Shi, Dong Wang, Juan Ni, Qiuyue Shen, Fan Yang, Guiliang Peng, Ling Zhou, Yuling Zhang, Zheng Sun, Hongting Zheng, Min Long

Faculty, Staff and Students Publications

BACKGROUND: Diaphanous related formin 1 (DIAPH1) is a novel component of advanced glycation end product (AGE) signal transduction that was recently found to participate in diabetes-related disorders, obesity, and androgen hormones. We investigated whether plasma DIAPH1 levels were a potential prognostic predictor for polycystic ovary syndrome (PCOS).

METHODS: The levels of circulating plasma DIAPH1 and indicators of glucose, insulin, lipid metabolism, liver enzymes, kidney function, sex hormones, and inflammation were measured in 75 patients with PCOS and 77 healthy participants. All of the participants were divided into normal-weight (NW) and overweight/obese (OW) subgroups. Statistical analyses were performed with R studio. …

De Novo Glycine Synthesis Is Reduced In Adults With Morbid Obesity And Increases Following Bariatric Surgery, Hong Chang Tan, Jean W Hsu, E Shyong Tai, Shaji Chacko, Vieon Wu, Chun Fan Lee, Jean-Paul Kovalik, Farook Jahoor

Faculty, Staff and Students Publications

BACKGROUND: Glycine is a dietary non-essential amino acid that is low in obesity and increases following bariatric surgery. However, the exact mechanism responsible remains unclear and it is unknown whether hypoglycinemia is a cause or consequence of insulin resistance.

OBJECTIVE: Using multiple isotopically labeled tracers, we aimed to determine the underlying kinetic changes responsible for hypoglycinemia in obesity by: 1) Comparing glycine kinetics between participants with morbid obesity (BMI ≥ 32.5 kg/m

METHODS: [1,2-

RESULTS: Compared to controls, participants with morbid obesity had significantly lower plasma glycine concentrations at 163 (153-171) vs. 201 (172-227) µmol/L and significantly reduced

CONCLUSION: Hypoglycinemia …

A Novel Model Of Gestational Diabetes: Acute High Fat High Sugar Diet Results In Insulin Resistance And Beta Cell Dysfunction During Pregnancy In Mice, Akansha Mishra, Simone Hernandez Ruano, Pradip K Saha, Kathleen A Pennington

Faculty, Staff and Students Publications

Gestational diabetes mellitus (GDM) affects 7–18% of all pregnancies. Despite its high prevalence, there is no widely accepted animal model. To address this, we recently developed a mouse model of GDM. The goal of this work was to further characterize this animal model by assessing insulin resistance and beta cell function. Mice were randomly assigned to either control (CD) or high fat, high sugar (HFHS) diet and mated 1 week later. At day 0 (day of mating) mice were fasted and intraperitoneal insulin tolerance tests (ipITT) were performed. Mice were then euthanized and pancreata were collected for histological analysis. Euglycemic …

Rap1 In The Vmh Regulates Glucose Homeostasis, Kentaro Kaneko, Hsiao-Yun Lin, Yukiko Fu, Pradip K Saha, Ana B De La Puente-Gomez, Yong Xu, Kousaku Ohinata, Peter Chen, Alexei Morozov, Makoto Fukuda

Faculty, Staff and Students Publications

The hypothalamus is a critical regulator of glucose metabolism and is capable of correcting diabetes conditions independently of an effect on energy balance. The small GTPase Rap1 in the forebrain is implicated in high-fat diet-induced (HFD-induced) obesity and glucose imbalance. Here, we report that increasing Rap1 activity selectively in the medial hypothalamus elevated blood glucose without increasing the body weight of HFD-fed mice. In contrast, decreasing hypothalamic Rap1 activity protected mice from diet-induced hyperglycemia but did not prevent weight gain. The remarkable glycemic effect of Rap1 was reproduced when Rap1 was specifically deleted in steroidogenic factor-1-positive (SF-1-positive) neurons in the …

Ube2i Deletion In Adipocytes Causes Lipoatrophy In Mice, Aaron R Cox, Natasha Chernis, Kang Ho Kim, Peter M Masschelin, Pradip K Saha, Shawn M Briley, Robert Sharp, Xin Li, Jessica B Felix, Zheng Sun, David D Moore, Stephanie A Pangas, Sean M Hartig

Faculty, Staff and Students Publications

OBJECTIVE: White adipose tissue (WAT) expansion regulates energy balance and overall metabolic homeostasis. The absence or loss of WAT occurring through lipodystrophy and lipoatrophy contributes to the development of hepatic steatosis and insulin resistance. We previously demonstrated that sole small ubiquitin-like modifier (SUMO) E2-conjugating enzyme Ube2i represses human adipocyte differentiation. The role of Ube2i during WAT development remains unknown.

METHODS: To determine how Ube2i impacts body composition and energy balance, we generated adipocyte-specific Ube2i knockout mice (Ube2i

RESULTS: Surprisingly, Ube2i

CONCLUSIONS: Our results demonstrate that Ube2i expression in mature adipocytes allows WAT expansion during postnatal growth. Deletion of Ube2i in …

Rev-Erb In Gabaergic Neurons Controls Diurnal Hepatic Insulin Sensitivity, Guolian Ding, Xin Li, Xinguo Hou, Wenjun Zhou, Yingyun Gong, Fuqiang Liu, Yanlin He, Jia Song, Jing Wang, Paul Basil, Wenbo Li, Sichong Qian, Pradip Saha, Jinbang Wang, Chen Cui, Tingting Yang, Kexin Zou, Younghun Han, Christopher I Amos, Yong Xu, Li Chen, Zheng Sun

Faculty, Staff and Students Publications

Systemic insulin sensitivity shows diurnal rhythm with a peak at wakening1,2. The molecular mechanism underlying such a temporal pattern is unclear. Here we demonstrate that nuclear receptors Rev-erbα/β in the GABAergic neurons in the suprachiasmatic nucleus (SCNGABA) control the diurnal rhythm of insulin-mediated suppression of hepatic glucose production in mice, without affecting diurnal eating or locomotor behaviors under the regular light-dark cycles. Rev-erb regulates the rhythmic expression of genes involved in neurotransmission in the SCN and modulates the oscillatory firing activity of SCNGABA neurons. Chemogenetic stimulation of SCNGABA neurons at wakening causes glucose intolerance, while restoration …

Loss Of Bone Morphogenetic Protein-Binding Endothelial Regulator Causes Insulin Resistance, Hua Mao, Luge Li, Qiying Fan, Aude Angelini, Pradip K Saha, Huaizhu Wu, Christie M Ballantyne, Sean M Hartig, Liang Xie, Xinchun Pi

Faculty, Staff and Students Publications

Accumulating evidence suggests that chronic inflammation of metabolic tissues plays a causal role in obesity-induced insulin resistance. Yet, how specific endothelial factors impact metabolic tissues remains undefined. Bone morphogenetic protein (BMP)–binding endothelial regulator (BMPER) adapts endothelial cells to inflammatory stress in diverse organ microenvironments. Here, we demonstrate that BMPER is a driver of insulin sensitivity. Both global and endothelial cell-specific inducible knockout of BMPER cause hyperinsulinemia, glucose intolerance and insulin resistance without increasing inflammation in metabolic tissues in mice. BMPER can directly activate insulin signaling, which requires its internalization and interaction with Niemann-Pick C1 (NPC1), an integral membrane protein that …

Association Of Baseline Characteristics With Insulin Sensitivity And Β-Cell Function In The Glycemia Reduction Approaches In Diabetes: A Comparative Effectiveness (Grade) Study Cohort, Neda Rasouli, Naji Younes, Kristina M Utzschneider, Silvio E Inzucchi, Ashok Balasubramanyam, Andrea L Cherrington, Faramarz Ismail-Beigi, Robert M Cohen, Darin E Olson, Ralph A Defronzo, William H Herman, John M Lachin, Steven E Kahn, Grade Research Group

Faculty, Staff and Students Publications

OBJECTIVE: We investigated sex and racial differences in insulin sensitivity, β-cell function, and glycated hemoglobin (HbA

RESEARCH DESIGN AND METHODS: This is a cross-sectional analysis of baseline data from 3,108 GRADE (Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study) participants. All had type 2 diabetes diagnosedβ-cell function were evaluated using the HOMA of insulin sensitivity and estimates from oral glucose tolerance tests, including the Matsuda Index, insulinogenic index, C-peptide index, and oral disposition index (DI).

RESULTS: The cohort was 56.6 ± 10 years of age (mean ± SD), 63.8% male, with BMI 34.2 ± 6.7 kg/m

CONCLUSIONS: In the …

Association Of Baseline Characteristics With Insulin Sensitivity And Β-Cell Function In The Glycemia Reduction Approaches In Diabetes: A Comparative Effectiveness (Grade) Study Cohort, Neda Rasouli, Naji Younes, Kristina M Utzschneider, Silvio E Inzucchi, Ashok Balasubramanyam, Andrea L Cherrington, Faramarz Ismail-Beigi, Robert M Cohen, Darin E Olson, Ralph A Defronzo, William H Herman, John M Lachin, Steven E Kahn

Faculty, Staff and Students Publications

OBJECTIVE: We investigated sex and racial differences in insulin sensitivity, β-cell function, and glycated hemoglobin (HbA

RESEARCH DESIGN AND METHODS: This is a cross-sectional analysis of baseline data from 3,108 GRADE (Glycemia Reduction Approaches in Diabetes: A Comparative Effectiveness Study) participants. All had type 2 diabetes diagnosedβ-cell function were evaluated using the HOMA of insulin sensitivity and estimates from oral glucose tolerance tests, including the Matsuda Index, insulinogenic index, C-peptide index, and oral disposition index (DI).

RESULTS: The cohort was 56.6 ± 10 years of age (mean ± SD), 63.8% male, with BMI 34.2 ± 6.7 kg/m

CONCLUSIONS: In the …