Medicine and Health Sciences Commons^™

Free Fatty Acid Treatment Alters Autophagy During Mouse Preimplantation Embryo Development, Zuleika C. L. Leung

Electronic Thesis and Dissertation Repository

Obesity-induced hyperlipidemia is one of the main factors for female infertility. Hyperlipidemia, specifically with high levels of palmitic acid (PA) and oleic acid (OA), interferes with preimplantation development. Autophagy is essential in early embryo development but, it is unknown whether hyperlipidemia affects autophagic mechanisms in preimplantation embryos. It was hypothesized that PA will alter autophagy in preimplantation mouse embryos and that the subsequent effects will be reversed by OA. PA impaired blastocyst development by arresting embryos at the 8-cell stage. PA also elevated early embryo autophagy by increasing autophagosome formation, decreasing maturation, and disrupting degradation. Co-treatment with OA showed developmental …

Exploring Β-Cell Function And Heterogeneity In Obese Sm/J Mice, Mario Alejandro Miranda

Arts & Sciences Electronic Theses and Dissertations

Pancreatic β-cells perform glucose-stimulated insulin secretion, a process required to maintain systemic glucose homeostasis. Obesity promotes glycemic and inflammatory stress, causing β-cell death and dysfunction, resulting in diabetes. Efforts to improve β-cell function in obesity have been hampered by observations that β-cells are highly heterogeneous, varying in morphology, function, and gene expression. There is great need to understand the breadth of β-cell heterogeneity in health and obesity to improve diabetic therapies.High fat-fed SM/J mice spontaneously transition from hyperglycemic-obese to normoglycemic-obese with age, providing a unique opportunity to study β-cell adaptation. Here, we show that as they resolve hyperglycemia, obese SM/J …

Human Regulatory T Cells Control Inflammation From Effector T Cells In Prediabetes, Rui Liu

Theses and Dissertations--Pharmacy

Type 2 diabetes (T2D) is a chronic low-grade inflammatory disease. A T cell cytokine profile (Th17) from PBMCs can distinguish obese T2D from obese non-diabetes subjects. Individual T cell subsets interact with each other and the diverse subsets jointly determine overall inflammation. Cellular metabolism drives cytokine production of CD4⁺ T cells, and therefore contributes to inflammation in T2D. However, specific changes in metabolism and function of CD4⁺ T cells during the progression from lean healthy to obese and diabetic stages in people have not been clarified.

We hypothesize that human regulatory T cells (Treg) impact metabolism of effector …

Cold-Induced Metabolic Changes In Lean, Nag-1 Transgenic Mice, Rachel J. Davey

All Master's Theses

Obesity is a multifaceted metabolic disorder with severe worldwide public health consequences. While obesity can often be treated using diet and exercise, there are complex genetic interactions driving obesity that don’t always respond to such changes. One important research focus for addressing genetic factors is activating brown adipose tissue which increases thermogenesis, the process of burning stored fats to generate heat. Cold exposure is a known way to activate brown adipose tissue through b3-adrenergic signaling. This signaling pathway causes an upregulation of thermogenesis in brown adipocytes and beige adipocytes, which is white adipose tissue that “browns” and becomes metabolically active. …

Adipose-Derived Autotaxin Regulates Inflammation And Steatosis Associated With Diet-Induced Obesity, J. Anthony Brandon, Maria Kraemer, Julia Vandra, Suchismita Halder, Margo F. Ubele, Andrew J. Morris, Susan S. Smyth

Gill Heart & Vascular Institute Faculty Publications

Autotaxin (ATX) is a secreted enzyme that generates the bioactive lipid lysophosphatidic acid (LPA). We generated mice with global inducible post-natal inactivation or adipose-specific loss of the Enpp2 gene encoding ATX. The animals are phenotypically unremarkable and exhibit differences in adipocyte size and adipose tissue expression of inflammatory genes after high fat feeding without gross differences in fat distribution or body mass. Surprisingly, both models of Enpp2- deficiency exhibited marked protection from high fat diet-induced hepatic steatosis. This phenotype was not associated with differences in dietary fat absorption but may be accounted for by differences in hepatic expression of …

Visceral Adipose Tissue Modulates Radiosensitivity In Oesophageal Adenocarcinoma, Ann Marie Mongan, Niamh Lynam-Lennon, Suzanne Doyle, Rory Casey, Eibhlin Carr, Aoife Cannon, Melissa J Conroy, Graham P Pidgeon, Lorraine Brennan, Joanne Lysaght, John V. Reynolds, Jacintha O’Sullivan

Articles

Oesophageal adenocarcinoma (OAC) is an exemplar model of obesity-associated cancer. Response to neoadjuvant chemoradiotherapy (NA CRT) is a clinical challenge. We examined if visceral adipose tissue and obesity status alter radiosensitivity in OAC. The radioresistant (OE33R) and radioresponsive (OE33P) OAC isogenic model was cultured with adipose tissue conditioned media from three patient cohorts: non-cancer patients, surgery only OAC patients and NA CRT OAC patients. Cell survival was characterised by clonogenic assay, metabolomic profiling by nuclear magnetic resonance spectroscopy and adipokine receptor gene expression by qPCR. A retrospective in vivo study compared tumour response to NA CRT in normal weight (n=53) …

Obesity, Noah Rhodes

Global Issues in Public Health

Obesity is a worldwide issue that can be defined as a non-communicable condition which means that it is non-infectious and non-transmissible and it is defined as having a BMI over 30 even though BMI doesn’t account for the person’s muscle mass which causes some athletes to be considered obese just because they weigh a lot for their height. Diagnosing obesity can be a long process which includes a health history being taken, a general physical exam, calculation of BMI, and measuring waist circumference. Diagnosis of obesity also involves checking for problems such as high blood pressure, variation of cholesterol levels …

Pleiotropy Of Genetic Variants On Obesity And Smoking Phenotypes: Results From The Oncoarray Project Of The International Lung Cancer Consortium, Tao Wang, Jee-Young Moon, Yiqun Wu, Christopher I. Amos, Rayjean J. Hung, Adonina Tardon, Angeline Andrew, Chu Chen, David C. Christiani, Demetrios Albanes, Erik H. F. M. Van Der Heijden, Eric Duell, Gadi Rennert, Gary Goodman, Geoffrey Liu, James D. Mckay, Jian-Min Yuan, John K. Field, Jonas Manjer, Kjell Grankvist, Lambertus A. Kiemeney, Loic Le Marchand, M. Dawn Teare, Matthew B. Schabath, Mattias Johansson, Melinda C. Aldrich, Michael Davies, Mikael Johansson, Ming-Sound Tsao, Neil Caporaso, Susanne Arnold

Internal Medicine Faculty Publications

Obesity and cigarette smoking are correlated through complex relationships. Common genetic causes may contribute to these correlations. In this study, we selected 241 loci potentially associated with body mass index (BMI) based on the Genetic Investigation of ANthropometric Traits (GIANT) consortium data and calculated a BMI genetic risk score (BMI-GRS) for 17,037 individuals of European descent from the Oncoarray Project of the International Lung Cancer Consortium (ILCCO). Smokers had a significantly higher BMI-GRS than never-smokers (p = 0.016 and 0.010 before and after adjustment for BMI, respectively). The BMI-GRS was also positively correlated with pack-years of smoking (p < 0.001) in smokers. Based on causal network inference analyses, seven and five of 241 SNPs were classified to pleiotropic models for BMI/smoking status and BMI/pack-years, respectively. Among them, three and four SNPs associated with smoking status and pack-years (p < 0.05), respectively, were followed up in the ever-smoking data of the Tobacco, Alcohol and Genetics (TAG) consortium. Among these seven candidate SNPs, one SNP (rs11030104, BDNF) …

Panx1 And Panx3 Regulate Adipocyte Development And Fat Accumulation In Vivo, Vanessa R. Lee

Electronic Thesis and Dissertation Repository

The obesity epidemic is a growing concern due to its various comorbidities and associated risk factors. Pannexins 1 and 3 (Panx1 and Panx3), are members of a family of channel-forming glycoproteins that have been reported to be important in paracrine signaling and development. Panx1 and Panx3 are homologous and are regulated in many different cell types, mediating cell proliferation and differentiation. We have shown that Panx1 and Panx3 are expressed in adipocytes and adipose-derived stromal cells (ASCs) throughout the process of differentiation. Mice globally lacking Panx1 (Panx1 KO) have significantly greater total fat mass compared to wildtype (WT) mice under …

Uncovering New Roles For The Aryl Hydrocarbon Receptor (Ahr) In Breast Cancer, Justin Kirk Tomblin

Theses, Dissertations and Capstones

The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that is responsive to many exogenous and endogenous ligands. AHR is of particular interest in cancer, and has been shown to play roles in tumor progression. As such, it has received growing attention as a possible chemotherapeutic target. Obesity increases the risk of breast cancer, complicates treatment of breast cancer, and stimulates the growth of larger, more aggressive mammary tumors. Many breast tumors in obese women are estrogen receptor (ER)-positive and, while targeting hormone receptors like ER is beneficial, many obese women see a recurrence of their cancer after standard …

Genetic Modification Of Human Mesenchymal Stem Cells Helps To Reduce Adiposity And Improve Glucose Tolerance In An Obese Diabetic Mouse Model., Sabyasachi Sen, Cleyton C Domingues, Carol Rouphael, Cyril Chou, Chul Kim, Nagendra Yadava

Medicine Faculty Publications

INTRODUCTION: Human mesenchymal stem cells (MSCs) are multipotent cells that can differentiate into fat, muscle, bone and cartilage cells. Exposure of subcutaneous abdominal adipose tissue derived AD-MSCs to high glucose (HG) leads to superoxide accumulation and up-regulation of inflammatory molecules. Our aim was to inquire how HG exposure affects MSCs differentiation and whether the mechanism is reversible.

METHODS: We exposed human adipose tissue derived MSCs to HG (25 mM) and compared it to normal glucose (NG, 5.5 mM) exposed cells at 7, 10 and 14 days. We examined mitochondrial superoxide accumulation (Mitosox-Red), cellular oxygen consumption rate (OCR, Seahorse) and gene …

Brown And Beige Adipocytes: Effects Of Inflammation And Nutritional Intervention, Jiyoung Bae

Doctoral Dissertations

Recent findings of brown adipocytes and brown-like or beige adipocytes, capable of dissipating energy as heat, in adult humans have promised new hope for obesity treatment and prevention. Understanding of the regulation of brown and beige adipocytes will provide novel strategies to reach the goal. Pattern recognition receptors (PRR) are responsible for inflammation in adipose tissue, which leads to adipose dysfunction and obesity associated chronic diseases. It has been shown that PRR activation induces inflammation, leading to insulin resistance in white adipocytes and white adipose tissue (WAT). However, the roles of PRR activation in brown adipocytes and brown adipose tissue …

Mobilization Of Adipose Stromal Cells In Obesity And Cancer By Sparc And Its Proteolytic Isoforms, Chieh Tseng

Dissertations & Theses (Open Access)

Obesity increases cancer risk and progression as shown by epidemiologic studies. However, the underlying pathophysiology remained unclear. Adipose stromal cells (ASC) are adipose tissue-derived mesenchymal progenitors, abundant in white adipose tissue (WAT). In this study, we show that the ASC pool is expanded in obesity and is associated with promoted tumor growth. Next, by using a chimeric GFP-RFP bone marrow transplant model, we observed higher tumor infiltrating cells with ASC phenotype in obese mice compared to lean. Consistently, systemic circulating ASC frequency is six fold higher in tumor-bearing obese mice compared to lean. The tumor infiltrating cells with ASC phenotype …

Characterization Of Ghrelin O-Acyltransferase Active Site, Leslie Patton

Honors Capstone Projects - All

Ghrelin, first discovered in 1999, is a 28-amino acid peptide hormone involved in the regulation of appetite, insulin secretion and sensitivity, and many neurological effects such as learning, memory, and depression.^1-6 Ghrelin has been identified to have a unique posttranslational octanoylation carried out by the enzyme ghrelin O-acyltransferase (GOAT). This distinctive modification is a point of interest in studying GOAT whereby blocking the acylation of the ghrelin could potentially halt the activity of the peptide hormone and provide a means of treating obesity, diabetes, and other diseases affected by ghrelin levels. The duration of my project involved working …

Metformin-Induced Pedf Expression Regulates Cell Proliferation And Lipid Metabolism In Prostate Cancer Cells, Miguel Angel Tolentino

Theses and Dissertations

Prostate cancer (PCa) is one of the most common cancers in American males. A high fat diet and obesity accelerate PCa progression and increase the 1risk of death from disease. Epidemiological studies have indicated that PCa patients with type 2 diabetes have higher mortality rates than PCa patients without diabetes. Type 2 diabetics who are on metformin, a drug to control blood sugar levels, show a delay in PCa progression in comparison with PCa patients with type 2 diabetes who are not on metformin. It has been proposed that metformin inhibits proliferation via activation of AMP-activated protein kinase (AMPK) or …

Acceleration Of The Panin Development In Mice Expressing Oncogenic K-Ras Due To A High Fat Diet, Bincy Philip

Dissertations & Theses (Open Access)

Obesity is postulated to be one of the major risk factors for pancreatic cancer, and recently it was indicated that an elevated body mass index (BMI correlates strongly with a decrease in patient survival. Despite the evident relationship, the molecular mechanisms involved are unclear. Oncogenic mutation of K-Ras is found early and is universal in pancreatic cancer. Extensive evidence indicates oncogenic K-Ras is not entirely active and it requires a triggering event to surpass the activity of Ras beyond the threshold necessary for a Ras-inflammation feed-forward loop. We hypothesize that high fat intake induces a persistent low level inflammatory response …

Diet, Obesity And Reflux In The Etiology Of Adenocarcinomas Of The Esophagus And Gastric Cardia In Humans, Susan Mayne, Stephanie A. Navarro Silvera

Department of Public Health Scholarship and Creative Works

Incidence rates for esophageal adenocarcinoma have increased >350% since the mid-1970s. Rates for gastric cardia adenocarcinoma have also increased, although less steeply. This led to the initiation of large population-based case-control studies, particularly in the United States and Sweden, aimed at identifying risk factors for these cancers. Results have been emerging from these studies, with the consistent finding that obesity and gastroesophageal reflux disease are important risk factors for these cancers. Analyses of dietary factors are also available and indicate that diets high in total fat, saturated fat and cholesterol are associated with an increased risk of these cancers, whereas …