Endocrinology, Diabetes, and Metabolism Commons^™

Deficiency Of Stat1 In Cd11c+ Cells Alters Adipose Tissue Inflammation And Improves Metabolic Dysfunctions In Mice Fed A High-Fat Diet, Antu Antony, Zeqin Lian, Xiaoyuan Dai Perrard, Jerry Perrard, Hua Liu, Aaron R Cox, Pradip Saha, Lothar Hennighausen, Sean M Hartig, Christie M Ballantyne, Huaizhu Wu

Faculty, Staff and Students Publications

CD11c+ macrophages/dendritic cells (MDCs) are increased and display the classically activated M1-like phenotype in obese adipose tissue (AT) and may contribute to AT inflammation and insulin resistance. Stat1 is a key transcription factor for MDC polarization into the M1-like phenotype. Here, we examined the role of Stat1 in obesity-induced AT MDC polarization and inflammation and insulin resistance using mice with specific knockout of Stat1 in MDCs (cKO). Stat1 was upregulated and phosphorylated, indicating activation, early and persistently in AT and AT MDCs of wild-type mice fed a high-fat diet (HFD). Compared with littermate controls, cKO mice fed an HFD (16 …

Parenteral Lipid Emulsions Induce Unique Ileal Fatty Acid And Metabolomic Profiles But Do Not Increase The Risk Of Necrotizing Enterocolitis In Preterm Pigs, William Yakah, Pratibha Singh, Joanne Brown, Barbara Stoll, Doug Burrin, Muralidhar H Premkumar, Hasan H Otu, Xuesong Gu, Simon T Dillon, Towia A Libermann, Steven D Freedman, Camilia R Martin

Children’s Nutrition Research Center Staff Publications

Necrotizing enterocolitis (NEC) is a manifestation of maladaptive intestinal responses in preterm infants centrally medicated by unattenuated inflammation. Early in the postnatal period, preterm infants develop a deficit in arachidonic and docosahexaenoic acid, both potent regulators of inflammation. We hypothesized that the fatty acid composition of parenteral lipid emulsions uniquely induces blood and intestinal fatty acid profiles which, in turn, modifies the risk of NEC development. Forty-two preterm pigs were randomized to receive one of three lipid emulsions containing 100% soybean oil (SO), 15% fish oil (MO15), or 100% fish oil (FO100) with enteral feedings over an 8-day protocol. Blood …

Intestinal Stem Cell-Derived Enteroids From Morbidly Obese Patients Preserve Obesity-Related Phenotypes: Elevated Glucose Absorption And Gluconeogenesis, Nesrin M Hasan, Kelli F Johnson, Jianyi Yin, Nicholas W Baetz, Lea Fayad, Vadim Sherman, Sarah E Blutt, Mary K Estes, Vivek Kumbhari, Nicholas C Zachos, Olga Kovbasnjuk

Faculty, Staff and Students Publications

OBJECTIVE: The mechanisms behind the efficacy of bariatric surgery (BS) for treating obesity and type 2 diabetes, particularly with respect to the influence of the small bowel, remain poorly understood. In vitro and animal models are suboptimal with respect to their ability to replicate the human intestinal epithelium under conditions induced by obesity. Human enteroids have the potential to accelerate the development of less invasive anti-obesity therapeutics if they can recapitulate the pathophysiology of obesity. Our aim was to determine whether adult stem cell-derived enteroids preserve obesity-characteristic patient-specific abnormalities in carbohydrate absorption and metabolism.

METHODS: We established 24 enteroid lines …

Parenteral Fish-Oil Containing Lipid Emulsions Limit Initial Lipopolysaccharide-Induced Host Immune Responses In Preterm Pigs, William Yakah, David Ramiro-Cortijo, Pratibha Singh, Joanne Brown, Barbara Stoll, Madhulika Kulkarni, Berthe C Oosterloo, Doug Burrin, Krishna Rao Maddipati, Raina N Fichorova, Steven D Freedman, Camilia R Martin

Children’s Nutrition Research Center Staff Publications

Multicomponent lipid emulsions are available for critical care of preterm infants. We sought to determine the impact of different lipid emulsions on early priming of the host and its response to an acute stimulus. Pigs delivered 7d preterm (n = 59) were randomized to receive different lipid emulsions for 11 days: 100% soybean oil (SO), mixed oil emulsion (SO, medium chain olive oil and fish oil) including 15% fish oil (MO15), or 100% fish oil (FO100). On day 11, pigs received an 8-h continuous intravenous infusion of either lipopolysaccharide (LPS—lyophilized Escherichia coli) or saline. Plasma was collected for …

Agrp Neurons Trigger Long-Term Potentiation And Facilitate Food Seeking, Chunmei Wang, Wenjun Zhou, Yang He, Tiffany Yang, Pingwen Xu, Yongjie Yang, Xing Cai, Julia Wang, Hesong Liu, Meng Yu, Chen Liang, Tingting Yang, Hailan Liu, Makoto Fukuda, Qingchun Tong, Qi Wu, Zheng Sun, Yanlin He, Yong Xu

Children’s Nutrition Research Center Staff Publications

Sufficient feeding is essential for animals' survival, which requires a cognitive capability to facilitate food seeking, but the neurobiological processes regulating food seeking are not fully understood. Here we show that stimulation of agouti-related peptide-expressing (AgRP) neurons triggers a long-term depression (LTD) of spontaneous excitatory post-synaptic current (sEPSC) in adjacent pro-opiomelanocortin (POMC) neurons and in most of their distant synaptic targets, including neurons in the paraventricular nucleus of the thalamus (PVT). The AgRP-induced sEPCS LTD can be enhanced by fasting but blunted by satiety signals, e.g. leptin and insulin. Mice subjected to food-seeking tasks develop similar neural plasticity in AgRP-innervated …

Crucial Role Of Mammalian Glutaredoxin 3 In Cardiac Energy Metabolism In Diet-Induced Obese Mice Revealed By Transcriptome Analysis, Ninghui Cheng, Qianxing Mo, Jimmonique Donelson, Lingfei Wang, Ghislain Breton, George G Rodney, Jin Wang, Kendal D Hirschi, Xander H T Wehrens, Paul A Nakata

Children’s Nutrition Research Center Staff Publications

Obesity is often associated with metabolic dysregulation and oxidative stress with the latter serving as a possible unifying link between obesity and cardiovascular complications. Glutaredoxins (Grxs) comprise one of the major antioxidant systems in the heart. Although Grx3 has been shown to act as an endogenous negative regulator of cardiac hypertrophy and heart failure, its metabolic impact on cardiac function in diet-induced obese (DIO) mice remains largely unknown. In the present study, analysis of Grx3 expression indicated that Grx3 protein levels, but not mRNA levels, were significantly increased in the hearts of DIO mice. Cardiac-specific Grx3 deletion (Grx3 CKO) mice …

Tph2 In The Dorsal Raphe Nuclei Regulates Energy Balance In A Sex-Dependent Manner, Hailan Liu, Chunmei Wang, Meng Yu, Yongjie Yang, Yang He, Hesong Liu, Chen Liang, Longlong Tu, Nan Zhang, Lina Wang, Julia Wang, Feng Liu, Fang Hu, Yong Xu

Children’s Nutrition Research Center Staff Publications

AbstractCentral 5-hydroxytryptamine (5-HT), which is primarily synthesized by tryptophan hydroxylase 2 (TPH2) in the dorsal Raphe nuclei (DRN), plays a pivotal role in the regulation of food intake and body weight. However, the physiological functions of TPH2 on energy balance have not been consistently demonstrated. Here we systematically investigated the effects of TPH2 on energy homeostasis in adult male and female mice. We found that the DRN harbors a similar amount of TPH2+ cells in control male and female mice. Adult-onset TPH2 deletion in the DRN promotes hyperphagia and body weight gain only in male mice, but not in female …

The Bile Acid Induced Hepatokine Orosomucoid Suppresses Adipocyte Differentiation, Sung Ho Lee, Jong Min Choi, Sung Yun Jung, Aaron R Cox, Sean M Hartig, David D Moore, Kang Ho Kim

Faculty, Staff and Students Publications

Bile acids have recently emerged as key metabolic hormones with beneficial impacts in multiple metabolic diseases. We previously discovered that hepatic bile acid overload distally modulates glucose and fatty acid metabolism in adipose tissues to exert anti-obesity effects. However, the detailed mechanisms that explain the salutary effects of serum bile acid elevation remain unclear. Here, proteomic profiling identified a new hepatokine, Orosomucoid (ORM) that governs liver-adipose tissue crosstalk. Hepatic ORMs were highly induced by both genetic and dietary bile acid overload. To address the direct metabolic effects of ORM, purified ORM proteins were administered during adipogenic differentiation of 3T3-L1 cells …

Stat1 Dissociates Adipose Tissue Inflammation From Insulin Sensitivity In Obesity, Aaron R Cox, Natasha Chernis, David A Bader, Pradip K Saha, Peter M Masschelin, Jessica B Felix, Robert Sharp, Zeqin Lian, Vasanta Putluri, Kimal Rajapakshe, Kang Ho Kim, Dennis T Villareal, Reina Armamento-Villareal, Huaizhu Wu, Cristian Coarfa, Nagireddy Putluri, Sean M Hartig

Faculty, Staff and Students Publications

Obesity fosters low-grade inflammation in white adipose tissue (WAT) that may contribute to the insulin resistance that characterizes type 2 diabetes. However, the causal relationship of these events remains unclear. The established dominance of STAT1 function in the immune response suggests an obligate link between inflammation and the comorbidities of obesity. To this end, we sought to determine how STAT1 activity in white adipocytes affects insulin sensitivity. STAT1 expression in WAT inversely correlated with fasting plasma glucose in both obese mice and humans. Metabolomic and gene expression profiling established STAT1 deletion in adipocytes (STAT1a-KO) enhanced mitochondrial function …

Modeling Age-Dependent Developmental Changes In The Expression Of Genes Involved In Citrulline Synthesis Using Pig Enteroids, Mahmoud A Mohammad, Inka C Didelija, Barbara Stoll, Douglas G Burrin, Juan C Marini

Children’s Nutrition Research Center Staff Publications

metabolism of citrulline and arginine are well characterized. Enteroids, a novel ex-vivo model that recreates the three-dimensional structure of the intestinal crypt-villus unit, have shown to replicate molecular and physiological profiles of the intestinal segment from where they originated ("location memory").

Objective: The present study tested the hypothesis that enteroids recapitulate the developmental changes observed in vivo regarding citrulline production in pigs ("developmental memory").

Methods: Preterm (10- and 5-d preterm) and term pigs at birth, together with 7- and 35-d-old pigs were studied. Gene expression was measured in jejunal samples and in enteroids derived from this segment. Whole body citrulline …

The Central Melanocortin System And Human Obesity, Yongjie Yang, Yong Xu

Children’s Nutrition Research Center Staff Publications

The prevalence of obesity and the associated comorbidities highlight the importance of understanding the regulation of energy homeostasis. The central melanocortin system plays a critical role in controlling body weight balance. Melanocortin neurons sense and integrate the neuronal and hormonal signals, and then send regulatory projections, releasing anorexigenic or orexigenic melanocortin neuropeptides, to downstream neurons to regulate the food intake and energy expenditure. This review summarizes the latest progress in our understanding of the role of the melanocortin pathway in energy homeostasis. We also review the advances in the identification of human genetic variants that cause obesity via mechanisms that …

Mir-30a Targets Gene Networks That Promote Browning Of Human And Mouse Adipocytes, Pradip K Saha, Mark P Hamilton, Kimal Rajapakshe, Vasanta Putluri, Jessica B Felix, Peter Masschelin, Aaron R Cox, Mandeep Bajaj, Nagireddy Putluri, Cristian Coarfa, Sean M Hartig

Faculty, Staff and Students Publications

MicroRNA-30a (miR-30a) impacts adipocyte function, and its expression in white adipose tissue (WAT) correlates with insulin sensitivity in obesity. Bioinformatic analysis demonstrates that miR-30a expression contributes to 2% of all miRNA expression in human tissues. However, molecular mechanisms of miR-30a function in fat cells remain unclear. Here, we expanded our understanding of how miR-30a expression contributes to antidiabetic peroxisome proliferator-activated receptor-γ (PPARγ) agonist activity and metabolic functions in adipocytes. We found that WAT isolated from diabetic patients shows reduced miR-30a levels and diminished expression of the canonical PPARγ target genes ADIPOQ and FABP4 relative to lean counterparts. In human adipocytes, …

Loss Of Uncoupling Protein 3 Attenuates Western Diet-Induced Obesity, Systemic Inflammation, And Insulin Resistance In Rats, Tyler M Lomax, Sadia Ashraf, Gizem Yilmaz, Romain Harmancey

Faculty, Staff and Student Publications

OBJECTIVE: Uncoupling protein 3 (UCP3) is a mitochondrial carrier related to fatty acid metabolism. Although gene variants of UCP3 are associated with human obesity, their contribution to increased adiposity remains unclear. This study investigated the impact that loss of UCP3 has on diet-induced obesity in rats.

METHODS: Male UCP3 knockout rats (ucp3

RESULTS: Loss of UCP3 decreased fat mass gain, white adipocytes size, and systemic inflammation. The ucp3

CONCLUSIONS: Loss of UCP3 partially protects rats from diet-induced obesity. This phenotype is related to induction of a compensatory antioxidant mechanism and prevention of iBAT whitening.

Mtor-Initiated Metabolic Switch And Degeneration In The Retinal Pigment Epithelium, Young-Mi Go, Jing Zhang, Jolyn Fernandes, Christopher Litwin, Rui Chen, Theodore G Wensel, Dean P Jones, Jiyang Cai, Yan Chen

Faculty, Staff and Students Publications

The retinal pigment epithelium (RPE) is a particularly vulnerable tissue to age-dependent degeneration. Over the life span, the RPE develops an expanded endo-lysosomal compartment to maintain the high efficiency of phagocytosis and degradation of photoreceptor outer segments (POS) necessary for photoreceptor survival. As the assembly and activation of the mechanistic target of rapamycin complex 1 (mTORC1) occur on the lysosome surface, increased lysosome mass with aging leads to higher mTORC1 activity. The functional consequences of hyperactive mTORC1 in the RPE are unclear. In the current study, we used integrated high-resolution metabolomic and genomic approaches to examine mice with RPE-specific deletion …

Paraventricular Hypothalamus Mediates Diurnal Rhythm Of Metabolism, Eun Ran Kim, Yuanzhong Xu, Ryan M Cassidy, Yungang Lu, Yongjie Yang, Jinbin Tian, De-Pei Li, Rachel Van Drunen, Aleix Ribas-Latre, Zhao-Lin Cai, Mingshan Xue, Benjamin R Arenkiel, Kristin Eckel-Mahan, Yong Xu, Qingchun Tong

Children’s Nutrition Research Center Staff Publications

Defective rhythmic metabolism is associated with high-fat high-caloric diet (HFD) feeding, ageing and obesity; however, the neural basis underlying HFD effects on diurnal metabolism remains elusive. Here we show that deletion of BMAL1, a core clock gene, in paraventricular hypothalamic (PVH) neurons reduces diurnal rhythmicity in metabolism, causes obesity and diminishes PVH neuron activation in response to fast-refeeding. Animal models mimicking deficiency in PVH neuron responsiveness, achieved through clamping PVH neuron activity at high or low levels, both show obesity and reduced diurnal rhythmicity in metabolism. Interestingly, the PVH exhibits BMAL1-controlled rhythmic expression of GABA-A receptor γ2 subunit, and dampening …

Disrupted Hypothalamic Crh Neuron Responsiveness Contributes To Diet-Induced Obesity, Canjun Zhu, Yuanzhong Xu, Zhiying Jiang, Jin Bin Tian, Ryan M Cassidy, Zhao-Lin Cai, Gang Shu, Yong Xu, Mingshan Xue, Benjamin R Arenkiel, Qingyan Jiang, Qingchun Tong

Children’s Nutrition Research Center Staff Publications

The current obesity epidemic mainly results from high-fat high-caloric diet (HFD) feeding and may also be contributed by chronic stress; however, the neural basis underlying stress-related diet-induced obesity remains unknown. Corticotropin-releasing hormone (CRH) neurons in the paraventricular hypothalamus (PVH), a known body weight-regulating region, represent one key group of stress-responsive neurons. Here, we found that HFD feeding blunted PVH CRH neuron response to nutritional challenges as well as stress stimuli and dexamethesone, which normally produce rapid activation and inhibition on these neurons, respectively. We generated mouse models with the activity of these neurons clamped at high or low levels, both …

Parenteral Lipids Shape Gut Bile Acid Pools And Microbiota Profiles In The Prevention Of Cholestasis In Preterm Pigs, Lee Call, Tiffany Molina, Barbara Stoll, Greg Guthrie, Shaji Chacko, Jogchum Plat, Jason Robinson, Sen Lin, Caitlin Vonderohe, Mahmoud Mohammad, Dennis Kunichoff, Stephanie Cruz, Patricio Lau, Muralidhar Premkumar, Jon Nielsen, Zhengfeng Fang, Oluyinka Olutoye, Thomas Thymann, Robert Britton, Per Sangild, Douglas Burrin

Children’s Nutrition Research Center Staff Publications

Multi-component lipid emulsions, rather than soy-oil emulsions, prevent cholestasis by an unknown mechanism. Here, we quantified liver function, bile acid pools, and gut microbial and metabolite profiles in premature parenterally fed pigs given a soy-oil lipid emulsion, Intralipid (IL), a multi component lipid emulsion, SMOFlipid (SMOF), a novel emulsion with a modified fatty-acid composition [experimental emulsion (EXP)], or a control enteral diet (ENT) for 22 days. We assayed serum cholestasis markers, measured total bile acid levels in plasma, liver, and gut contents, and analyzed colonic bacterial 16S rRNA gene sequences and metabolomic profiles. Serum cholestasis markers (i.e., bilirubin, bile acids, …

Myeloma Cells Shift Osteoblastogenesis To Adipogenesis By Inhibiting The Ubiquitin Ligase Murf1 In Mesenchymal Stem Cells, Zhiqiang Liu, Huan Liu, Jin He, Pei Lin, Qiang Tong, Jing Yang

Faculty, Staff and Students Publications

The suppression of bone formation is a hallmark of multiple myeloma. Myeloma cells inhibit osteoblastogenesis from mesenchymal stem cells (MSCs), which can also differentiate into adipocytes. We investigated myeloma-MSC interactions and the effects of such interactions on the differentiation of MSCs into adipocytes or osteoblasts using single-cell RNA sequencing, in vitro co-culture, and subcutaneous injection of MSCs and myeloma cells into mice. Our results revealed that the α4 subunit of integrin on myeloma cells stimulated vascular cell adhesion molecule 1 (VCAM1) on MSCs, leading to the activation of protein kinase C β1 (PKCβ1) signaling and repression of the muscle ring-finger …

Estrogen Receptor-Α Expressing Neurons In The Ventrolateral Vmh Regulate Glucose Balance, Yanlin He, Pingwen Xu, Chunmei Wang, Yan Xia, Meng Yu, Yongjie Yang, Kaifan Yu, Xing Cai, Na Qu, Kenji Saito, Julia Wang, Ilirjana Hyseni, Matthew Robertson, Badrajee Piyarathna, Min Gao, Sohaib A Khan, Feng Liu, Rui Chen, Cristian Coarfa, Zhongming Zhao, Qingchun Tong, Zheng Sun, Yong Xu

Children’s Nutrition Research Center Staff Publications

Brain glucose-sensing neurons detect glucose fluctuations and prevent severe hypoglycemia, but mechanisms mediating functions of these glucose-sensing neurons are unclear. Here we report that estrogen receptor-α (ERα)-expressing neurons in the ventrolateral subdivision of the ventromedial hypothalamic nucleus (vlVMH) can sense glucose fluctuations, being glucose-inhibited neurons (GI-ERαvlVMH) or glucose-excited neurons (GE-ERαvlVMH). Hypoglycemia activates GI-ERαvlVMH neurons via the anoctamin 4 channel, and inhibits GE-ERαvlVMH neurons through opening the ATP-sensitive potassium channel. Further, we show that GI-ERαvlVMH neurons preferentially project to the medioposterior arcuate nucleus of the hypothalamus (mpARH) and GE-ERαvlVMH neurons preferentially project to the dorsal Raphe nuclei (DRN). Activation of ERαvlVMH …

Dietary Fat And Sugar Differentially Affect Β-Adrenergic Stimulation Of Cardiac Erk And Akt Pathways In C57bl/6 Male Mice Subjected To High-Calorie Feeding, Sadia Ashraf, Gizem Yilmaz, Xu Chen, Romain Harmancey

Faculty, Staff and Student Publications

BACKGROUND: High dietary fat and sugar promote cardiac hypertrophy independently from an increase in blood pressure. The respective contribution that each macronutrient exerts on cardiac growth signaling pathways remains unclear.

OBJECTIVE: The goal of this study was to investigate the mechanisms by which high amounts of dietary fat and sugar affect cardiac growth regulatory pathways.

METHODS: Male C57BL/6 mice (9 wk old; n = 20/group) were fed a standard rodent diet (STD; kcal% protein-fat-carbohydrate, 29-17-54), a high-fat diet (HFD; 20-60-20), a high-fat and high-sugar Western diet (WD; 20-45-35), a high-sugar diet with mixed carbohydrates (HCD; 20-10-70), or a high-sucrose diet …

Metabolic-Sensing Of The Skeletal Muscle Clock Coordinates Fuel Oxidation, Hongshan Yin, Weini Li, Somik Chatterjee, Xuekai Xiong, Pradip Saha, Vijay Yechoor, Ke Ma

Faculty, Staff and Students Publications

Circadian clock confers temporal control in metabolism, with its disruption leading to the development of insulin resistance. Metabolic substrate utilization in skeletal muscle is coordinated with diurnal nutrient cycles. However, whether the molecular clock is involved in this coordination is largely unknown. Using a myocyte-selective genetic ablation mouse model of the essential clock activator Bmal1, here we identify muscle-intrinsic clock as a sensor of feeding cues to orchestrate skeletal muscle oxidation required for global nutrient flux. Bmal1 in skeletal muscle responds robustly to feeding in vivo and insulin induces its expression. Muscle Bmal1 deficiency impaired the transcriptional control of glucose …

Neurochemical Characterization Of Brainstem Pro-Opiomelanocortin Cells, Teodora Georgescu, David Lyons, Barbora Doslikova, Ana Paula Garcia, Oliver Marston, Luke K Burke, Raffaella Chianese, Brian Y H Lam, Giles S H Yeo, Justin J Rochford, Alastair S Garfield, Lora K Heisler

Faculty, Staff and Student Publications

Genetic research has revealed pro-opiomelanocortin (POMC) to be a fundamental regulator of energy balance and body weight in mammals. Within the brain, POMC is primarily expressed in the arcuate nucleus of the hypothalamus (ARC), while a smaller population exists in the brainstem nucleus of the solitary tract (POMCNTS). We performed a neurochemical characterization of this understudied population of POMC cells using transgenic mice expressing green fluorescent protein (eGFP) under the control of a POMC promoter/enhancer (PomceGFP). Expression of endogenous Pomc mRNA in the nucleus of the solitary tract (NTS) PomceGFP cells was confirmed using fluorescence-activating cell sorting (FACS) followed by …

Metabolic Dysregulation In The Atp7b-/- Wilson's Disease Mouse Model, Clavia Ruth Wooton-Kee, Matthew Robertson, Ying Zhou, Bingning Dong, Zhen Sun, Kang Ho Kim, Hailan Liu, Yong Xu, Nagireddy Putluri, Pradip Saha, Cristian Coarfa, David D Moore, Alli M Nuotio-Antar

Faculty, Staff and Students Publications

Inactivating mutations in the copper transporter Atp7b result in Wilson’s disease. The Atp7b−/− mouse develops hallmarks of Wilson’s disease. The activity of several nuclear receptors decreased in Atp7b−/− mice, and nuclear receptors are critical for maintaining metabolic homeostasis. Therefore, we anticipated that Atp7b−/− mice would exhibit altered progression of diet-induced obesity, fatty liver, and insulin resistance. Following 10 wk on a chow or Western-type diet (40% kcal fat), parameters of glucose and lipid homeostasis were measured. Hepatic metabolites were measured by liquid chromatography–mass spectrometry and correlated with transcriptomic data. Atp7b−/− mice fed a chow diet presented …

Sirt3 Promotes Lipophagy And Chaperon-Mediated Autophagy To Protect Hepatocytes Against Lipotoxicity, Tian Zhang, Jingxin Liu, Shengnan Shen, Qiang Tong, Xiaojun Ma, Ligen Lin

Faculty, Staff and Students Publications

Lipophagy is a lysosomal lipolytic pathway that complements the actions of cytosolic neutral lipases. Chaperon-mediated autophagy (CMA) triggers lipid droplets (LDs) breakdown, to initiate lipolysis via either cytosolic lipases or macroautophagy. SIRT3, a mitochondrial NAD+-dependent deacetylase, regulates the acetylation status and activity of many substrates involving in energy metabolism. However, the role of SIRT3 in regulating lipophagy is controversial. The current study showed that SIRT3 expression was decreased and the macroautophagy flux was blocked in the primary hepatocytes from high-fat diet fed mice and P/O (palmitic acid and oleic acid mixture) treated AML12 mouse hepatocytes, compared with the corresponding controls. …

Steroid Receptor Coactivator-1 Modulates The Function Of Pomc Neurons And Energy Homeostasis, Yongjie Yang, Agatha A Van Der Klaauw, Liangru Zhu, Tessa M Cacciottolo, Yanlin He, Lukas K J Stadler, Chunmei Wang, Pingwen Xu, Kenji Saito, Antentor Hinton, Xiaofeng Yan, Julia M Keogh, Elana Henning, Matthew C Banton, Audrey E Hendricks, Elena G Bochukova, Vanisha Mistry, Katherine L Lawler, Lan Liao, Jianming Xu, Stephen O'Rahilly, Qingchun Tong, Uk10k Consortium, Inês Barroso, Bert W O'Malley, I Sadaf Farooqi, Yong Xu

Children’s Nutrition Research Center Staff Publications

Hypothalamic neurons expressing the anorectic peptide Pro-opiomelanocortin (Pomc) regulate food intake and body weight. Here, we show that Steroid Receptor Coactivator-1 (SRC-1) interacts with a target of leptin receptor activation, phosphorylated STAT3, to potentiate Pomc transcription. Deletion of SRC-1 in Pomc neurons in mice attenuates their depolarization by leptin, decreases Pomc expression and increases food intake leading to high-fat diet-induced obesity. In humans, fifteen rare heterozygous variants in SRC-1 found in severely obese individuals impair leptin-mediated Pomc reporter activity in cells, whilst four variants found in non-obese controls do not. In a knock-in mouse model of a loss of function …

Morphometric Characteristics And Time To Hatch As Efficacious Indicators For Potential Nanotoxicity Assay In Zebrafish, Seyed-Mohammadreza Samaee, Nafiseh Manteghi, Robert A. Yokel, Mohammad Reza Mohajeri-Tehrani

Pharmaceutical Sciences Faculty Publications

Although the effects of nano-sized titania (nTiO₂) on hatching events (change in hatching time and total hatching) in zebrafish have been reported, additional consequences of nTiO₂ exposure (i.e., the effects of nTiO₂-induced changes in hatching events and morphometric parameters on embryo-larvae development and survivability) have not been reported. To address this knowledge gap, embryos 4 h postfertilization were exposed to nTiO₂ (0, 0.01, 10, and 1000 μg/mL) for 220 h. Hatching rate (58, 82, and 106 h postexposure [hpe]), survival rate (8 times from 34 to 202 hpe), and 21 morphometric characteristics (8 times …

The Dual Role Of Group V Secretory Phospholipase A2 In Pancreatic Β-Cells, Preetha Shridas, Victoria P. Noffsinger, Andrea C. Trumbauer, Nancy R. Webb

Saha Cardiovascular Research Center Faculty Publications

Purpose

Group X (GX) and group V (GV) secretory phospholipase A₂ (sPLA₂) potently release arachidonic acid (AA) from the plasma membrane of intact cells. We previously demonstrated that GX sPLA₂ negatively regulates glucose-stimulated insulin secretion (GSIS) by a prostaglandin E2 (PGE2)-dependent mechanism. In this study we investigated whether GV sPLA₂ similarly regulates GSIS.

Methods

GSIS and pancreatic islet-size were assessed in wild-type (WT) and GV sPLA₂-knock out (GV KO) mice. GSIS was also assessed ex vivo in isolated islets and in vitro using MIN6 pancreatic beta cell lines with or without GV sPLA …

The Impact Of Sglt2 Inhibitors, Compared With Insulin, On Diabetic Bone Disease In A Mouse Model Of Type 1 Diabetes, Kathryn M. Thrailkill, Jeffry S. Nyman, R. Clay Bunn, Sasidhar Uppuganti, Katherine L. Thompson, Charles K. Lumpkin, Evangelia Kalaitzoglou, John L. Fowlkes

Barnstable Brown Diabetes Center Faculty Publications

Skeletal co-morbidities in type 1 diabetes include an increased risk for fracture and delayed fracture healing, which are intertwined with disease duration and the presence of other diabetic complications. As such, chronic hyperglycemia is undoubtedly a major contributor to these outcomes, despite standard insulin-replacement therapy. Therefore, using the streptozotocin (STZ)-induced model of hypoinsulinemic hyperglycemia in DBA/2J male mice, we compared the effects of two glucose lowering therapies on the fracture resistance of bone and markers of bone turnover. Twelve week-old diabetic (DM) mice were treated for 9 weeks with: 1) oral canagliflozin (CANA, dose range ~10-16 mg/kg/day), an inhibitor of …

Serum Amyloid A Impairs The Antiinflammatory Properties Of Hdl, Chang Yeop Han, Chongren Tang, Myriam E. Guevara, Hao Wei, Tomasz Wietecha, Baohai Shao, Savitha Subramanian, Mohamed Omer, Shari Wang, Kevin D. O'Brien, Santica M. Marcovina, Thomas N. Wight, Tomas Vaisar, Maria C. De Beer, Frederick C. De Beer, William R. Osborne, Keith B. Elkon, Alan Chait

Physiology Faculty Publications

HDL from healthy humans and lean mice inhibits palmitate-induced adipocyte inflammation; however, the effect of the inflammatory state on the functional properties of HDL on adipocytes is unknown. Here, we found that HDL from mice injected with AgNO₃ fails to inhibit palmitate-induced inflammation and reduces cholesterol efflux from 3T3-L1 adipocytes. Moreover, HDL isolated from obese mice with moderate inflammation and humans with systemic lupus erythematosus had similar effects. Since serum amyloid A (SAA) concentrations in HDL increase with inflammation, we investigated whether elevated SAA is a causal factor in HDL dysfunction. HDL from AgNO₃-injected mice lacking Saa1.1 …

Sglt2 Inhibitor Therapy Improves Blood Glucose But Does Not Prevent Diabetic Bone Disease In Diabetic Dba/2j Male Mice, Kathryn M. Thrailkill, R. Clay Bunn, Jeffry S. Nyman, Mallikarjuna R. Rettiganti, Gael E. Cockrell, Elizabeth C. Wahl, Sasidhar Uppuganti, Charles K. Lumpkin, John L. Fowlkes

Barnstable Brown Diabetes Center Faculty Publications

Persons with type 1 and type 2 diabetes have increased fracture risk, attributed to deficits in the microarchitecture and strength of diabetic bone, thought to be mediated, in part, by the consequences of chronic hyperglycemia. Therefore, to examine the effects of a glucose-lowering SGLT2 inhibitor on blood glucose (BG) and bone homeostasis in a model of diabetic bone disease, male DBA/2J mice with or without streptozotocin (STZ)-induced hyperglycemia were fed chow containing the SGLT2 inhibitor, canagliflozin (CANA), or chow without drug, for 10 weeks of therapy. Thereafter, serum bone biomarkers were measured, fracture resistance of cortical bone was assessed by …