Life Sciences Commons^™

Mitochondrial Roles In Developmentally Programmed Heart Disease, Eli John Louwagie

Dissertations and Theses

Offspring of diabetic and obese mothers (ODOM) have greater risks of heart disease at birth and later in life. However, prevention is hindered because underlying mechanisms are poorly understood. Mounting studies in the Developmental Origins of Health and Disease field suggest that mitochondria play key roles in developmentally programmed heart disease similar to the roles they play in cardiomyopathy in adults with diabetes and obesity. However, whether mitochondria are responsible for the short[1]and long-term cardiac disease seen in ODOM remains unknown. Here, we sought to delineate the roles of mitochondria in the hearts of ODOM, determine whether mitochondria are playing …

Maternal Angiotensinogen Genotype And Fetal Sex Impact Uteroplacental Function And The Developmental Origins Of Stress-Induced Hypertension, Jessica Faith Hebert

Dissertations and Theses

Fetal growth restriction (FGR) is a common and potentially life-threatening complication that affects 5-10% of human pregnancies. Maternal genetic predisposition and fetal male sex are known risk factors, but the underlying mechanisms are unknown. To study a known maternal genetic risk factor and the impact of fetal sex, we employed a published transgenic (TG) mouse model, which was designed to mimic a common human angiotensinogen (AGT) promoter variant associated with a 20% increase in circulating AGT levels. We hypothesized that TG dams would deliver growth restricted pups and that the underlying mechanism would be related to differences in maternal uterine …

Wnt Secretion Proteins Modulate Rankl-Induced Expression Of Aire In Thymic Epithelial Cells, Daniel Pollack

Dissertations and Theses

Thymic epithelial cells (TEC) are essential for a proper adaptive immune response by regulating thymocyte development and establishing central tolerance. In the thymus, TECs differentially express Wnt proteins, which activate canonical and non-canonical Wnt signaling pathways. Wnt signaling is thought to regulate cell survival, proliferation, and development although the direct molecular mechanisms in TECs have yet to be elucidated. The inducible inhibition of canonical Wnt signaling with Dkk1 leads to a rapid loss of TEC progenitors as well as a decline in mature Aire-expressing mTECs. Therefore, we explore the role of Wnt ligands potentially responsible for stimulating and/or regulating Wnt …

Bone Marrow Derived Progenitor Cells And Their Contributions To The Thymic Stroma, Mohammed Hoque

Dissertations and Theses

The thymus serves as the primary lymphoid organ responsible for the development and selection of a self-tolerant T cell repertoire. In paradox to its critical functions for the adaptive immune response, the thymus undergoes a profound age associated decline beginning in early adult life resulting in significant decline in T-cell function.Thymic epithelial cells (TECs) are the most critical component of the thymic microenvironment and undergo rapid turn-over, so understanding the cellular mechanisms responsible for the maintenance of TEC number and organization will be critical in counteracting age associated involution, particularly in cancer patients, due to enhanced degeneration in response to …

Insulin-Like Growth Factor Pathway Described In Austrofundulus Limnaeus Diapause And Escape Embryos, Steven Cody Woll

Dissertations and Theses

Development in the annual killifish Austrofundulus limnaeus can follow two distinct developmental trajectories. Typical development includes the entrance of embryos into a state of metabolic and developmental arrest termed diapause. Alternately, embryos can escape diapause and develop directly without pause. These two trajectories are characterized by differences in the rate and timing of developmental, morphological, and physiological traits. Insulin and Insulin-like growth factor (IGF) signaling (IIS) is known to regulate entrance into diapause in a variety of invertebrates. In this thesis I explore the possible role of IGFs in the regulation of development and diapause in embryos of A. limnaeus …

Exploring Tissue Engineering: Vitamin D3 Influences On The Proliferation And Differentiation Of An Engineered Osteoblast Precursor Cell Line During Early Bone Tissue Development, Shelley S. Mason

Dissertations and Theses

Most of the load-bearing demand placed on the human body is transduced by skeletal tissue, and the capacity of the skeleton to articulate in various opposing directions is essential for body movement and locomotion. Consequently, cartilage and bone defects due to trauma, disease, and developmental abnormalities result in disabling pain and immobility for millions of people worldwide. A novel way of promoting cartilage and bone regeneration is through the incorporation of either primary cells or multipotent progenitor cells in a three-dimensional (3D) biomaterial scaffold, and/or the addition of exogenous growth and differentiation factors. The first part of this study reports …

The Effects Of Hypoxia And Temperature On Developing Embryos Of The Annual Killifish Austrofundulus Limnaeus, Skye N. Anderson

Dissertations and Theses

Little is known about the physiology or biochemistry of hypoxia (reduced levels of oxygen) tolerance during development in vertebrate embryos. In most species, relatively brief bouts of severe hypoxia are lethal or teratogenic. An exception to such hypoxia intolerance is the annual killifish Austrofundulus limnaeus, in which populations persist in hypoxic environments. This species inhabits seasonal ponds in Venezuela, surviving through the dry season in the form of diapausing embryos. Embedded in the pond sediment, embryos of A. limnaeus are routinely exposed to hypoxia and anoxia (lack of oxygen) as part of their normal development. Here, we exposed embryos to …

Metabolic Support Of Anaerobiosis In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Andrew Mccracken

Dissertations and Theses

Embryos of the annual killifish Austrofundulus limnaeus display a remarkable tolerance to anoxia during development, most notably during embryonic diapause. Little is known about the metabolic or enzymatic changes that accompany this state of anoxia tolerance. This study examined the metabolic changes associated with exposure to anoxia by measuring the activity of the enzyme phosphoenolpyruvate carboxykinase (PEPCK), and by profiling the concentration of 31 metabolites ranging from amino acids to citric cycle intermediates at 4 different developmental stages, diapause 2 (DII), 4 days post diapause (dpd), 12 and 22 dpd. Embryos of A. limnaeus showed stage specific changes in concentrations …

Origin Of Human Trisomy 21 Mosaicism, Diane Dusenbery Waggoner

Dissertations and Theses

Down Syndrome is a human condition caused by an extra copy of a #21 chromosome. At least one to two percent of free (not translocated) trisomy 21 cases are mosaics, i.e., they have two or more distinct cell lines. Usually, one cell line is 47 ,XX or XY ,+21 while the other cell line is normal 46,XX or 46,XY.

The purpose of the study was to establish the etiologies of the separate cell lines by determining whether the zygote was trisomic or normal. Meiotic non-disjunction in the formation of a gamete could lead to a trisomic zygote; loss of a …

Factors Affecting Thyrotropin Secretion In Superfused Rat Anterior Pituitary Cells, Frederick Scott Bartlow

Dissertations and Theses

The use of static in vitro pituitary cultures has been indispensible for examining the regulation of anterior pituitary hormone secretion. While the static cultures have shown the effects of various chemical stimulators of hormone secretion, the dynamics of such secretion has not been assessed before in vitro. The in vitro superfusion method, which partially stimulates in vivo physiologic conditions, allows for the observation of the dynamics of pituitary hormone secretion.

The Ductuli Efferentes In Macaca Mulatta: Electron Microscopic Evaluation Of Changes After Vasectomy, Loyal Douglas Marsh

Dissertations and Theses

After vasectomy, the passage of sperm antigen through the epithelium of the efferent duct in the rhesus macaque probably results in immune complex deposition. Immune complexes can be visualized in the thickened basement by fluorescence microscopy. Subsequent electron microscopic evaluation, with the appearance of electron-dense deposits in the basement membrane of the efferent ducts, substantiates these findings.

Storage And Use Of Glycogen By Juvenile Carcinonemertes Errans, D. Mitchell Wolgamott

Dissertations and Theses

Juvenile C. errans do not feed on particulate matter and yet they can survive, apparently unchanged, for several months before maturing into the adult stage which feeds on the eggs of Cancer magister. The significance of glycogen as an energy source for maintenance of the juvenile form was investigated.