Nutrition Commons^™

Gαi/O-Coupled Htr2c In The Paraventricular Nucleus Of The Hypothalamus Antagonizes The Anorectic Effect Of Serotonin Agents, Eun-Seon Yoo, Li Li, Lin Jia, Caleb C Lord, Charlotte E Lee, Shari G Birnbaum, Claudia R Vianna, Eric D Berglund, Kathryn A Cunningham, Yong Xu, Jong-Woo Sohn, Chen Liu

Children’s Nutrition Research Center Staff Publications

The anorexigenic effect of serotonergic compounds has largely been attributed to activation of serotonin 2C receptors (Htr2cs). Using mouse genetic models in which Htr2c can be selectively deleted or restored (in Htr2c-null mice), we investigate the role of Htr2c in forebrain Sim1 neurons. Unexpectedly, we find that Htr2c acts in these neurons to promote food intake and counteract the anorectic effect of serotonergic appetite suppressants. Furthermore, Htr2c marks a subset of Sim1 neurons in the paraventricular nucleus of the hypothalamus (PVH). Chemogenetic activation of these neurons in adult mice suppresses hunger, whereas their silencing promotes feeding. In …

Free-Floating Immunostaining Of Mouse Brains, Longlong Tu, Nan Zhang, Kristine M Conde, Jonathan C Bean, Chunmei Wang, Yong Xu

Children’s Nutrition Research Center Staff Publications

Immunohistochemical staining of mouse brains is a routine technique commonly used in neuroscience to investigate central mechanisms underlying the regulation of energy metabolism and other neurobiological processes. However, the quality, reliability, and reproducibility of brain histology results may vary among laboratories. For each staining experiment, it is necessary to optimize the key procedures based on differences in species, tissues, targeted proteins, and the working conditions of the reagents. This paper demonstrates a reliable workflow in detail, including intra-aortic perfusion, brain sectioning, free-floating immunostaining, tissue mounting, and imaging, which can be followed easily by researchers in this field.

Also discussed are …

The Concurrence Of Dna Methylation And Demethylation Is Associated With Transcription Regulation, Jiejun Shi, Jianfeng Xu, Yiling Elaine Chen, Jason Sheng Li, Ya Cui, Lanlan Shen, Jingyi Jessica Li, Wei Li

Children’s Nutrition Research Center Staff Publications

The mammalian DNA methylome is formed by two antagonizing processes, methylation by DNA methyltransferases (DNMT) and demethylation by ten-eleven translocation (TET) dioxygenases. Although the dynamics of either methylation or demethylation have been intensively studied in the past decade, the direct effects of their interaction on gene expression remain elusive. Here, we quantify the concurrence of DNA methylation and demethylation by the percentage of unmethylated CpGs within a partially methylated read from bisulfite sequencing. After verifying 'methylation concurrence' by its strong association with the co-localization of DNMT and TET enzymes, we observe that methylation concurrence is strongly correlated with gene expression. …

Barbadin Potentiates Long-Term Effects Of Lorcaserin On Pomc Neurons And Weight Loss, Yang He, Hailan Liu, Na Yin, Yongjie Yang, Chunmei Wang, Meng Yu, Hesong Liu, Chen Liang, Julia Wang, Longlong Tu, Nan Zhang, Lina Wang, Yanlin He, Makoto Fukuda, Qi Wu, Zheng Sun, Qingchun Tong, Yong Xu

Children’s Nutrition Research Center Staff Publications

Obesity is a serious global health problem because of its increasing prevalence and comorbidities, but its treatments are limited. The serotonin 2C receptor (5-HT_2CR), a G-protein-coupled receptor, activates proopiomelanocortin (POMC) neurons in the arcuate nucleus of hypothalamus (ARH) to reduce appetite and weight gain. However, several 5-HT analogs targeting this receptor, e.g., lorcaserin (Lor), suffer from diminished efficacy to reduce weight after prolonged administration. Here, we show that barbadin (Bar), a novel β-arrestin/β2-adaptin inhibitor, can prevent 5-HT_2CR internalization in cells and potentiate long-term effects of Lor to reduce appetite and body weight in male mice. Mechanistically, …

Restoration Of The Molecular Clock Is Tumor Suppressive In Neuroblastoma, Myrthala Moreno-Smith, Giorgio Milazzo, Ling Tao, Baharan Fekry, Bokai Zhu, Mahmoud A Mohammad, Simone Di Giacomo, Roshan Borkar, Karthik Reddy Kami Reddy, Mario Capasso, Sanjeev A Vasudevan, Pavel Sumazin, John Hicks, Nagireddy Putluri, Giovanni Perini, Kristin Eckel-Mahan, Thomas P Burris, Eveline Barbieri

Children’s Nutrition Research Center Staff Publications

MYCN activation is a hallmark of advanced neuroblastoma (NB) and a known master regulator of metabolic reprogramming, favoring NB adaptation to its microenvironment. We found that the expression of the main regulators of the molecular clock loops is profoundly disrupted in MYCN-amplified NB patients, and this disruption independently predicts poor clinical outcome. MYCN induces the expression of clock repressors and downregulates the one of clock activators by directly binding to their promoters. Ultimately, MYCN attenuates the molecular clock by suppressing BMAL1 expression and oscillation, thereby promoting cell survival. Reestablishment of the activity of the clock activator RORα via its genetic …

Deciphering An Agrp-Serotoninergic Neural Circuit In Distinct Control Of Energy Metabolism From Feeding, Yong Han, Guobin Xia, Dollada Srisai, Fantao Meng, Yanlin He, Yali Ran, Yang He, Monica Farias, Giang Hoang, István Tóth, Marcelo O Dietrich, Miao-Hsueh Chen, Yong Xu, Qi Wu

Children’s Nutrition Research Center Staff Publications

Contrasting to the established role of the hypothalamic agouti-related protein (AgRP) neurons in feeding regulation, the neural circuit and signaling mechanisms by which they control energy expenditure remains unclear. Here, we report that energy expenditure is regulated by a subgroup of AgRP neurons that send non-collateral projections to neurons within the dorsal lateral part of dorsal raphe nucleus (dlDRN) expressing the melanocortin 4 receptor (MC4R), which in turn innervate nearby serotonergic (5-HT) neurons. Genetic manipulations reveal a bi-directional control of energy expenditure by this circuit without affecting food intake. Fiber photometry and electrophysiological results indicate that the thermo-sensing MC4RdlDRN neurons …

Gene Expression Analysis Of Environmental Temperature And High-Fat Diet-Induced Changes In Mouse Supraclavicular Brown Adipose Tissue, Yufeng Shi, Honglei Zhai, Sharon John, Yi-Ting Shen, Yali Ran, Giang Hoang, Miao-Hsueh Chen

Children’s Nutrition Research Center Staff Publications

Obesity, a dysregulation of adipose tissue, is a major health risk factor associated with many diseases. Brown adipose tissue (BAT)-mediated thermogenesis can potentially regulate energy expenditure, making it an attractive therapeutic target to combat obesity. Here, we characterize the effects of cold exposure, thermoneutrality, and high-fat diet (HFD) feeding on mouse supraclavicular BAT (scBAT) morphology and BAT-associated gene expression compared to other adipose depots, including the interscapular BAT (iBAT). scBAT was as sensitive to cold induced thermogenesis as iBAT and showed reduced thermogenic effect under thermoneutrality. While both scBAT and iBAT are sensitive to cold, the expression of genes involved …

Defining Vdr Expression In The Brain Using A Novel Vdrcre Mouse, Hailan Liu, Yang He, Jessie Beck, Silvania Da Silva Teixeira, Keisha Harrison, Yong Xu, Stephanie Sisley

Children’s Nutrition Research Center Staff Publications

Vitamin D action has been linked to several diseases regulated by the brain including obesity, diabetes, autism, and Parkinson’s. However, the location of the vitamin D receptor (VDR) in the brain is not clear due to conflicting reports. We found that two antibodies previously published as specific in peripheral tissues are not specific in the brain. We thus created a new knockin mouse with cre recombinase expression under the control of the endogenous VDR promoter (VDRCre). We demonstrated that the cre activity in the VDRCre mouse brain (as reported by a cre-dependent tdTomato expression) is highly overlapping with endogenous VDR …

Cell Lineage Tracing Links Erα Loss In Erbb2-Positive Breast Cancers To The Arising Of A Highly Aggressive Breast Cancer Subtype, Yunfeng Ding, Yonghong Liu, Dong-Kee Lee, Zhangwei Tong, Xiaobin Yu, Yi Li, Yong Xu, Rainer B Lanz, Bert W O'Malley, Jianming Xu

Children’s Nutrition Research Center Staff Publications

HER2-positive (HER2+) breast cancers (BrCs) contain approximately equal numbers of ERα+HER2+ and ERα−HER2+ cases. An enduring obstacle is the unclear cell lineage-related characteristics of these BrCs. Although ERα+HER2+ BrCs could lose ERα to become ERα−HER2+ BrCs, direct evidence is missing. To investigate ERα dependencies and their implications during BrC growth and metastasis, we generated ERαCreRFP-T mice that produce an RFP-marked ERα+ mammary gland epithelial cell (MGEC) lineage. RCAS virus-mediated expression of Erbb2, a rodent Her2 homolog, first produced comparable numbers of ERα+RFP+Erbb2+ and ERα−RFP−Erbb2+ MGECs. Early hyperplasia developed mostly from ERα+RFP+Erbb2+ cells and ERα−RFP−Erbb2+ cells in these lesions were rare. …

A Neural Basis For Brain Leptin Action On Reducing Type 1 Diabetic Hyperglycemia, Shengjie Fan, Yuanzhong Xu, Yungang Lu, Zhiying Jiang, Hongli Li, Jessie C Morrill, Jing Cai, Qi Wu, Yong Xu, Mingshan Xue, Benjamin R Arenkiel, Cheng Huang, Qingchun Tong

Children’s Nutrition Research Center Staff Publications

Central leptin action rescues type 1 diabetic (T1D) hyperglycemia; however, the underlying mechanism and the identity of mediating neurons remain elusive. Here, we show that leptin receptor (LepR)-expressing neurons in arcuate (LepRArc) are selectively activated in T1D. Activation of LepRArc neurons, Arc GABAergic (GABAArc) neurons, or arcuate AgRP neurons, is able to reverse the leptin’s rescuing effect. Conversely, inhibition of GABAArc neurons, but not AgRP neurons, produces leptin-mimicking rescuing effects. Further, AgRP neuron function is not required for T1D hyperglycemia or leptin’s rescuing effects. Finally, T1D LepRArc neurons show defective nutrient sensing and signs of cellular energy deprivation, which are …

Sirt3 Is Required For Liver Regeneration But Not For The Beneficial Effect Of Nicotinamide Riboside, Sarmistha Mukherjee, James Mo, Lauren M Paolella, Caroline E Perry, Jade Toth, Mindy M Hugo, Qingwei Chu, Qiang Tong, Karthikeyani Chellappa, Joseph A Baur

Children’s Nutrition Research Center Staff Publications

Liver regeneration is critical to survival after traumatic injuries, exposure to hepatotoxins, or surgical interventions, yet the underlying signaling and metabolic pathways remain unclear. In this study, we show that hepatocyte-specific loss of the mitochondrial deacetylase SIRT3 drastically impairs regeneration and worsens mitochondrial function after partial hepatectomy. Sirtuins, including SIRT3, require NAD as a cosubstrate. We previously showed that the NAD precursor nicotinamide riboside (NR) promotes liver regeneration, but whether this involves sirtuins has not been tested. Here, we show that despite their NAD dependence and critical roles in regeneration, neither SIRT3 nor its nuclear counterpart SIRT1 is required 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 …

Profound And Redundant Functions Of Arcuate Neurons In Obesity Development, Canjun Zhu, Zhiying Jiang, Yuanzhong Xu, Zhao-Lin Cai, Qingyan Jiang, Yong Xu, Mingshan Xue, Benjamin R Arenkiel, Qi Wu, Gang Shu, Qingchun Tong

Children’s Nutrition Research Center Staff Publications

The current obesity epidemic faces a lack of mechanistic insights. It is known that the acute activity changes of a growing number of brain neurons rapidly alter feeding behaviour; however, how these changes translate to obesity development and the fundamental mechanism underlying brain neurons in controlling body weight remain elusive. Here, we show that chronic activation of hypothalamic arcuate GABAergic (GABA

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 …

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 …

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 …

Effects Of Six Common Dietary Nutrients On Murine Intestinal Organoid Growth, Tenson Cai, Yijun Qi, Albert Jergens, Michael Wannemuehler, Terrence A. Barrett, Qun Wang

Internal Medicine Faculty Publications

The intestinal epithelium of the gastrointestinal (GI) tract constantly renews itself to absorb nutrients and provide protection for the body from the outside world. Since the intestinal epithelium is constantly exposed to various chemicals and dietary components, it is critical to determine which constituents promote or inhibit intestinal epithelium health and growth rate. Intestinal organoids, three-dimensional miniature models of the intestines, represent an ex vivo tool to investigate intestinal physiology and growth patterns. In this study, we measured the growth rates of murine intestinal organoids exposed to various concentrations of different dietary constituents. Results indicate that caffeic acid inhibited organoid …

Influence Of Native And Processed Cereal Grain Fibers On Gut Health, Junyi Yang

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Cereal fibers that can be metabolized by gut microbiota have been shown to promote the growth of beneficial bacteria in the gut. Increased consumption of cereal fibers may improve host / gut microbiota interactions in obesity and other metabolic diseases by normalizing gut dysbiosis. The present dissertation describes four research projects to assess the impact of cereal dietary fibers on gut microbiota and host metabolism. In the first study, we determined the treatment temperatures for production of soluble, non-digestible, feruloylated oligo- and polysaccharides (FOPS) from maize bran and wheat bran, and determined the fermentation properties of partially purified FOPS from …

Effect Of Folate Deficiency On Mtor Signaling Network On The Liver Of Wild Type Mice, Essra Moussawi

Wayne State University Theses

Through various studies of dietary nutrients on the affects of the physiological and molecular pathways are a key study in understanding the interaction between dietary nutrients and the human genome that may severely impact the development of various cancers. A primary approach is observing the dietary nutrients, that we consume and how it plays a role in the cellular pathway of our bodies through experimental methods. Folate deficiency (FD) has shown, through studies, to play a role anti-cancer progression. Our goal was to observe the autophagy related proteins in the mTOR signaling pathway as it was suggested that mTOR may …

High Fat Diet Increased Serum Glutamate Dehydrogenase More Than Chronic Acetaminophen Dosing In Female Mice, Elizabeth Ruth Behmer

All Graduate Theses, Dissertations, and Other Capstone Projects

This laboratory study examined the effects of acetaminophen overdose in normal fed and high-fat fed female mice. Forty female mice were placed on normal and high-fat diets at 4 weeks old. When the mice were significantly different in weight (between 6 and 9 months old), half the mice were dosed with acetaminophen. These mice were daily given an overdose of acetaminophen for 14 days. The dose used was 300 mg/kg mouse (LD50 = 338 mg/kg). The control group was given 10 µl water/g mouse. Levels of serum glutamate dehydrogenase (GDH) were measured to indicate liver damage. GDH is released from …

Tlr4 Signaling Is Involved In Brain Vascular Toxicity Of Pcb153 Bound To Nanoparticles, Bei Zhang, Jeong June Choi, Sung Yong Eum, Sylvia Daunert, Michal Toborek

Graduate Center for Nutritional Sciences Faculty Publications

PCBs bind to environmental particles; however, potential toxicity exhibited by such complexes is not well understood. The aim of the present study is to study the hypothesis that assembling onto nanoparticles can influence the PCB153-induced brain endothelial toxicity via interaction with the toll-like receptor 4 (TLR4). To address this hypothesis, TLR4-deficient and wild type control mice (males, 10 week old) were exposed to PCB153 (5 ng/g body weight) bound to chemically inert silica nanoparticles (PCB153-NPs), PCB153 alone, silica nanoparticles (NPs; diameter, 20 nm), or vehicle. Selected animals were also subjected to 40 min ischemia, followed by a 24 h reperfusion. …

Thrombospondin1 Deficiency Reduces Obesity-Associated Inflammation And Improves Insulin Sensitivity In A Diet-Induced Obese Mouse Model, Yanzhang Li, Xiaopeng Tong, Courtney Rumala, Kate Clemons, Shuxia Wang

Graduate Center for Nutritional Sciences Faculty Publications

BACKGROUND: Obesity is prevalent worldwide and is associated with insulin resistance. Advanced studies suggest that obesity-associated low-grade chronic inflammation contributes to the development of insulin resistance and other metabolic complications. Thrombospondin 1 (TSP1) is a multifunctional extracellular matrix protein that is up-regulated in inflamed adipose tissue. A recent study suggests a positive correlation of TSP1 with obesity, adipose inflammation, and insulin resistance. However, the direct effect of TSP1 on obesity and insulin resistance is not known. Therefore, we investigated the role of TSP1 in mediating obesity-associated inflammation and insulin resistance by using TSP1 knockout mice.

METHODOLOGY/PRINCIPAL FINDINGS: Male TSP1-/- mice …

Srt1720 Improves Survival And Healthspan Of Obese Mice, Robin K. Minor, Joseph A. Baur, Ana P. Gomes, Theresa M. Ward, Anna Csiszar, Evi M. Mercken, Kotb Abdelmohsen, Yu-Kyong Shin, Carles Canto, Morten Scheibye-Knudsen, Melissa Krawczyk, Pablo M. Irusta, Alejandro Martín-Montalvo, Basil P. Hubbard, Yongqing Zhang, Elin Lehrmann, Alexa A. White, Nathan L. Price, William R. Swindell, Kevin J. Pearson, Kevin G. Becker, Vilhelm A. Bohr, Myriam Gorospe, Josephine M. Egan, Mark I. Talan, Johan Auwerx, Christoph H. Westphal, James L. Ellis, Zoltan Ungvari, George P. Vlasuk, Peter J. Elliott, David A. Sinclair, Rafael De Cabo

Graduate Center for Nutritional Sciences Faculty Publications

Sirt1 is an NAD(+)-dependent deacetylase that extends lifespan in lower organisms and improves metabolism and delays the onset of age-related diseases in mammals. Here we show that SRT1720, a synthetic compound that was identified for its ability to activate Sirt1 in vitro, extends both mean and maximum lifespan of adult mice fed a high-fat diet. This lifespan extension is accompanied by health benefits including reduced liver steatosis, increased insulin sensitivity, enhanced locomotor activity and normalization of gene expression profiles and markers of inflammation and apoptosis, all in the absence of any observable toxicity. Using a conditional SIRT1 knockout mouse and …