Endocrinology Commons^™

Molecular Mechanisms Of Exercise-Stimulated Resolution Of Inflammation And Its Dietary Dependence., Ernesto H. Pena Calderin

Electronic Theses and Dissertations

Diet-induced obesity and adipose tissue (AT) inflammation that ensues sets the stage for systemic metabolic inflammation, disrupted insulin signaling, and eventual type 2 diabetes (T2D) development. At the center of this pathology lies a disruption in endogenous inflammation resolution pathways characterized by an imbalance in lipid mediator production (greater abundance of pro-inflammatory to pro-resolving lipids). Additionally, obese states are characterized by adrenergic deficiency, especially in response to physical activity. Inflammatory processes have been experimentally mitigated by either the pharmacological inhibition of pro-inflammatory signals (i.e., Leukotriene B₄ (LTB₄) and its receptor BLT1, which establishes a potent chemotactic stimulus …

Air-Jet Bioprinting Of Stem Cell-Encapsulated Alginate Micro-Droplets For Organoid Biomanufacturing, Mirabella B. Stump

Electronic Theses and Dissertations

Biomanufactured 3D-organoids show promise for modeling and treating various conditions, particularly insulin-dependent diabetes mellitus (type-1 diabetes). Pancreatic islet organoids serve as sustainable sources of insulin-producing β-cells, potentially restoring insulin regulation in patients and providing a long-term solution for diabetes. Hydrogel droplet printing is an emerging technique in regenerative medicine due to its advantageous tunability and biocompatibility; however, challenges of consistency, quality control, and scalability persist. To address these issues, we developed a novel air-jetting based droplet bioprinting system for the generation of monodispersed alginate micro-droplets. The objective of this project was to incorporate human induced pluripotent stem cells (hiPSCs) into …

Importance Of The Microhabitat And Microclimate Conditions In The Northern Gray-Cheeked Salamander (Plethodon Montanus) Across An Elevation Gradient, Trevor Chapman

Electronic Theses and Dissertations

The southern Appalachian Mountains have among the highest salamander diversity in the world, largely due to local speciation in the family Plethodontidae. Plethodontid salamanders (i.e., lungless salamanders) are particularly sensitive to habitat climate conditions due to their reliance on cutaneous respiration, and their immediate environmental conditions (microhabitat) likely influence their dispersion and activity more than the large-scale atmospheric conditions. The Northern Gray-cheeked salamander (Plethodon montanus) is restricted to high elevations in the Appalachian Mountains. Our goal was to investigate the relationship between P. montanus and its microhabitat by examining behavioral preference for climatic conditions, characterizing the microclimate with …

Investigating Host Defenses Of North American Salamanders Against The Recently Emerged Chytrid Pathogen, Batrachochytrium Salamandrivorans, Kenzie Pereira

Electronic Theses and Dissertations

A recently emerged chytrid fungal pathogen, Batrachochytrium salamandrivorans (Bsal) threatens salamander biodiversity. Bsal susceptibility varies between and within salamander species, but little is known about the mechanisms underlying these differences. Susceptibility is likely influenced by numerous interacting factors, but my dissertation studied the role of host immune responses.

My first aim investigated between species differences by studying the bioactive properties of salamander skin peptides against Bsal and the related pathogen, B. dendrobatidis (Bd). Skin peptides were collected from five salamander species, used for in vitro assays, and analyzed by RP-HPLC. While skin peptides from one …

Characterization Of The Whale Shark (Rhincodon Typus) Melanocortin-2 Receptor, Brianne Hoglin

Electronic Theses and Dissertations

Among bony vertebrates, the melanocortin-2 receptor ortholog is unique among the family of five melanocortin receptors on the basis that it is dependent on its accessory protein, MRAP1, for trafficking and activation, and is selective for activation by ACTH alone. Previous studies on the MC2R orthologs of select cartilaginous fish, the elephant shark (Callorhinchus milii) and the red stingray (Dasyatis akajei), revealed divergent traits in a less obligatory relationship on MRAP1 and its ability to be activated by ACTH or the MSH-sized peptides. However, observed traits were not consistent between these two cartilaginous fish species, posing …

The Effect Of Ethanol On Skeletal Muscle Endocrine Function And The Novel Myokines Myonectin And Irisin, Kendra Hagood

Electronic Theses and Dissertations

Excessive alcohol consumption is a leading cause of death and disability globally and can lead to diseases such as alcoholic skeletal myopathy. Skeletal muscle is the largest organ in the human body and functions to regulate whole-body energy homeostasis. Additionally, skeletal muscle can function as an endocrine organ via secretion of myokines. Two myokines, myonectin and irisin, present a wide range of effects upon metabolism, inflammation, and tissue survival- signaling. We hypothesized that chronic alcohol consumption will result in reduced circulating myonectin and irisin levels. Mice were fed an ethanol-containing or control diet for 10 days or 6 weeks. Tissues …

The Effect Of Alcohol Consumption On Adipokine Secretion, Ashley Degroat

Electronic Theses and Dissertations

Alcoholic Fatty Liver Disease (AFLD) is caused by excessive alcohol consumption and is a leading cause of liver related mortalities, with currently no treatments available. The goal of this project was to establish the effect of alcohol consumption on adipose tissue-derived secreted factors, adiponectin and C1q TNF Related Proteins 1-3 (CTRP1-3). We propose that excessive alcohol consumption will reduce circulating levels of adiponectin and CTRPs 1-3. Mice were fed a Lieber-Decarli control or alcohol diet for 10-days with a gavage (NIAAA model) or 6-weeks with no gavage (chronic model). Serum and adipose tissue were collected and CTRPs 1-3 and adiponectin …

Glutathione S-Transferase P In Glucose Homeostasis In Mice., Shubha Ghosh Dastidar

Electronic Theses and Dissertations

High calorie diets have fostered the current pandemic of obesity and comorbid conditions of non-alcoholic fatty liver disease (NAFLD), systemic insulin resistance (IR) and type 2 diabetes (T2D). Hepatic glutathione S-transferases (GSTs) are dysregulated in obesity, NAFLD and diabetes. The multifunctional GST pi isoform (GSTP) catalyzes acrolein metabolism and inhibits JNK (c-Jun NH₂-terminal kinase). The purpose of this study was to test specifically whether GSTP deficiency disturbs glucose homeostasis in mice. Hepatic GST proteins were downregulated by short-term high fat diet (HFD) in wild type (WT) mice concomitant with glucose intolerance, increased hepatic JNK activation and protein-acrolein …

Using A Mouse Model To Investigate Male Bias In Autism Spectrum Disorder Incidence., Elizabeth Ann Gordon

Electronic Theses and Dissertations

The review (Chapter 1) overviews our current understanding of the sex bias in autism spectrum disorders (ASD), whereby males are 4 times more likely to develop the condition. The longstanding uncertainty surrounding the etiology of autism can be informed by inclusion of both sexes in future research to better understand the mechanism responsible for this sex bias. Both clinical studies and animal models are useful tools to elucidate the underlying cause(s) of sexual dimorphic morphological, physiological, and behavioral differences in the ASD phenotype. Sex differences in social behaviors are common across species, underscoring the importance of assessing baseline sex differences …

The Effects Of Stress Hormones On Preferences For Acoustic Signals In Female Green Treefrogs (Hyla Cinerea) And Barking Treefrogs (Hyla Gratiosa), Anna Gabriell Davis

Electronic Theses and Dissertations

Ecological stressors (i.e., high predator density, low food availability) are often associated with increased variation in mate choice by females. The association between environmental stressors and variation in mate choice suggests that circulating stress hormones (i.e., glucocorticoids) may mediate such effects, but this idea remains largely unexplored. I examined how circulating glucocorticoids affect preferences for male advertisement calls in female green treefrogs, Hyla cinerea, and barking treefrogs, Hyla gratiosa. Specifically, I examined whether administration of corticosterone (CORT) decreases preferences for call rate and/or call duration - two acoustic features that are highly variable and characteristically under directional selection via mate …

The Effects Of Intracerebroventricular Leptin On Milk Availability In Lactating Rats, Brittany Lynita Moore

Electronic Theses and Dissertations

Reports have linked energy balance along with adipocyte derived leptin action to improved fertility. Recent evidence indicates that leptin hormone is present in breast milk and leptin receptors are well expressed in mammary epithelial cells. The hypothesis that insufficiency of leptin restraint in the hypothalamus may underlie infertility in rodents and the failure of lactating breast to express adequate amount of milk was tested. Female Sprague-Dawley rats were injected leptin through intracerebroventricular cannulation (ICVC) of the third ventricle. Female rats were mated with stud males and observed throughout gestation. Compared to the control groups, leptin treatment increased prolactin levels in …

Analyzing The Interaction Between Melanocortin 5 Receptor, Melanocortin Receptor Accessory Protein 1, And Melanocortin 2 Receptor In Rainbow Trout, Domicinda M. Hill

Electronic Theses and Dissertations

Using CHO cells we sought to explore and characterize the functional relationship of rainbow trout MC5 receptor (rtMC5R) with zebrafish MRAP1 (zfMRAP1) and rainbow trout MC2 receptor (rtMC2R), as well as how the effect of such relationships may play a significant role in Hypothalamic-Pituitary-Adrenal/Interrenal axis activation. This research demonstrated that rtMC5R can be successfully expressed and functionally activated in CHO cells and, in a manner similar to mammals, α-MSH is the preferred ligand for rtMC5R. The presence of MRAP1 does not seem to inhibit the expression or function of rtMC5R, rather it appears that it may increase expression and total …