Medicine and Health Sciences Commons^™

Modulating The Mtor Pathway Using Inducible Retrogradely Transported Aavs As A Novel Approach To Improve Motor Recovery In Spinal Cord Injury, Christopher Bosse-Joseph

Theses and Dissertations--Medical Sciences

Spinal cord injury poses multiple regeneration barriers, including neuronal-intrinsic and extrinsic factors. Overcoming these barriers has stood as a longstanding challenge in neuroscience. A well-studied mechanism to promote spinal cord regeneration and locomotor recovery is activating the PI3K/mTOR pathway by knocking out phosphatase and tensin homolog protein (PTEN). PTEN knockout (PTEN-KO) studies have traditionally used adeno-associated virus (AAV) viral vectors to improve functional recovery. The use of traditional AAV serotypes to induce PTEN-KO has shown promise to improve functional recovery in rodent models; however, these approaches show significant limitations for translational utility. Firstly, the use of traditional AAV serotypes to …

Examining A Blood Biomarker Approach To Blood-Brain Barrier Disruption, Samantha Ford

Theses and Dissertations--Medical Sciences

Blood-brain barrier disruption has been identified to associate with the pathogenesis several neurological diseases such as dementia [1, 2], multiple sclerosis[3, 4], acute or chronic cerebral ischemia[5], brain trauma[5], meningitis[5], encephalitis[5], stroke[6], and seizures[7]. Being able to effectively identify blood-brain barrier disruption is limited in methodology. The current standard is using a cerebrospinal fluid (CSF) albumin to serum albumin index, which requires the use of a lumbar puncture. A novel method of identifying blood-brain barrier disruption utilizing blood biomarkers is proposed in this study. Participants in this study had previously collected blood and CSF samples, which were analyzed to compare …

Classification And Effect Of Correctors On Sitosterolemia-Associated Mutants In Abcg8, Brittney Poole

Theses and Dissertations--Medical Sciences

Objective: To classify mutants of ABCG8 identified in subjects with clinically confirmed Sitosterolemia, a rare form of Familial Hypercholesterolemia distinguished by the accumulation of phytosterols in plasma and tissues and determine the effects of correctors and/or regulators of proteostasis on maturation of the ABCG5/ABCG8 sterol transporter.

Methods: Disease-causing missense mutants within the cytosolic domain of ABCG8 were generated through site-directed mutagenesis. Normal and mutant proteins were expressed in human hepatocytes. Cellular proteins were prepared, and maturation was assessed by SDS-PAGE and immunoblotting. Formation of the higher molecular weight, mature form of glycoproteins was used as a bioassay for trafficking the …

Establishment And Verification Of A Sars Cov2 Antibody Detection Assay Comparing Venous And Mitra Samples, Stephen C. Mayer

Theses and Dissertations--Medical Sciences

During the COVID-19 pandemic in 2020, the need for highly-specific, wide-spread, and rapid serological testing surged. In this study, we showed very strong positive correlation between venous blood collection and Mitra home sampling kits for the detection of anti- spike IgGs using an in-house ELISA protocol (based on a protocol from Mt. Sinai). This study demonstrates the utility of using at-home, patient-centric testing to enhance the sero-surveillance methods currently in place for viral tracking and monitoring.

Investigating The Effects Of In-Vivo Therapeutics Hypoxia Treatment Paradigms In Neurite Outgrowth Patterns, Jae Hyun Yoo

Theses and Dissertations--Medical Sciences

Spinal cord injury, specifically in the cervical C3-C4 region of the cervical spine, contributes to impaired breathing and a diminished quality of life. Therefore it is important to find effective and safe therapeutics to restore breathing function. Indeed, there are a myriad of research being performed in addition to valuable collaboration amongst different institutions. As such, inspired by a previous experiment, we decided to test our hypothesis that an enriching environment consisting of different hypoxic environments - sustained and intermittent hypoxia alongside normoxia - would result in neurite outgrowth. Moreover, we hypothesized that sustained hypoxia would result in the greatest …

Mammalian Target Of Rapamycin Cell Signaling Pathway In Phosphatase And Tensin Homolog Induced Kinase 1 Knockout Rat Model Of Familial Parkinson's Disease, Martha Helena Mortell

Theses and Dissertations--Medical Sciences

More than 10 million people are living with Parkinson’s disease (PD), one million of which are people in the United States. PD is the second most common age-related neurodegenerative disorder, after Alzheimer’s disease, and is characterized by the accumulation of a-synuclein aggregates and the degeneration of dopaminergic neurons. The loss of endogenous dopamine in PD brain accounts for the motor decline presented clinically in PD patients. Etiological factors of PD include oxidative damage and inflammation, although the detailed mechanisms remain unknown. Risk factors for PD include gender, age, environmental factors, and gene mutations.

The current thesis research employed phosphatase and …

Apoe Genotype And Sex Modulate Ketogenic Diet Enhancements To Metabolism And Gut Microbiome In Young Mice, Andrew T. Yackzan

Theses and Dissertations--Medical Sciences

The apolipoprotein ε (APOE) allele in humans has been associated with risk for development of Alzheimer’s disease (AD). There are predominately three variations of the allele – ε2 (E2), ε3 (E3), and ε4 (E4) – with E4 contributing the greatest risk of AD development. Recent research has unveiled evidence of neurometabolic and neurovascular deficits in E4 carriers present decades before the onset of dementia; it is believed these chronic defects play a major role in the development of AD, thus making them a potential target for preventative intervention. The purpose of this study was to examine the effect of a …

Trem2: Gene Expression And Role In Alzheimer’S Disease, Henry Snider

Theses and Dissertations--Medical Sciences

Genetic mutations in the TREM2 gene are highly correlated with risk of Alzheimer’s disease, but alternative splicing patterns of TREM2 transcripts have not been fully described. Characterization of TREM2 alternative splicing will be of significant use to the scientific community as the field of Alzheimer’s disease research progresses. The goal of this study was to fully describe splicing patterns in TREM2, as different splicing isoforms of genes can alter express and/or function of the final protein. Human blood and anterior cingulate cortex brain tissue from 61 individual donors was processed and used for PCR and quantitative PCR as well as …

Acl Injury, A Time Course Study Of Transcriptional Changes, Thomas Carter

Theses and Dissertations--Medical Sciences

ACL tear is a common injury in the United States with a significant cost and time burden during recovery; reconstructive surgery often results in weakened quadricep muscle and higher risk of posttraumatic osteoarthritis. Prior research has highlighted cellular derangements within the quadriceps after ACL injury and reconstruction, but the early molecular effectors of cellular dysfunction remain to be identified. To further understand the molecular effectors of quadriceps dysfunction following ACL injury, this study aims to quantify the timing and magnitude of transcriptional differences between the quadriceps muscle of injured and contralateral non-injured limbs. These data will provide insight into the …

S. Gordonii-Produced Hydrogen Peroxide Modulates Mir-663a And Ccl20 Expression In Oral Epithelial Cells, Marshall Houston Maynard

Theses and Dissertations--Medical Sciences

The mechanisms through which a persistent recognition of commensal bacteria by oral epithelial cells (OECs) mitigates an uncontrolled inflammatory response of the oral mucosa remain unknown. CCL20 secretion by OECs in response to pathogenic bacteria is regulated by S. gordonii (Sg)-induced miR-663a; nevertheless, the mechanisms involved in these Sg-modulated responses remain to be elucidated. Since Sg is a hydrogen peroxide (H₂O₂) producer, and H₂O₂ has been shown to stimulate miRNA expression, we hypothesized that H₂O₂ could be involved in Sg-induced miR663a and CCL20 responses. Expression of miR663a …

The Role Of Vascular Endothelial Growth Factor In Leukemia Trafficking, Shaw Powell

Theses and Dissertations--Medical Sciences

Vascular endothelial growth factor (VEGF) is a signaling protein involved in inducing and regulating endothelial cell proliferation and function (Duffy et al 2000). VEGF is also involved in cancer progression, as it induces vascular permeability and promotes angiogenesis to tumor laden areas, giving cancer cells critical oxygen and nutrients (Hoeppner et al.,2012. Studies indicate VEGF prevents lymphoblast apoptosis, which may contribute to leukemia formation and enable the proliferation of leukemic cells (Duffy et al 2000). Ongoing research seeks to further examine VEGF in leukemia, using a rag2:GFP-Myc expressing transgenic zebrafish as the animal model of T-cell Acute Lymphoblastic Leukemia (T-ALL). …

Measuring The Effects Of Lobinaline-N-Bioxide (419) On Alcohol Consumption, Nicotine Locomotor Sensitization, And Conditioned Place Preference In Mice And Rats, Cocanut M. Suhail

Theses and Dissertations--Medical Sciences

Objective: Novel drug 419 was examined to see the effect it has in vivo mice and rats on alcohol consumption, nicotine locomotor sensitization, and conditioned place preference (CPP) models regarding behavioral tests on dopamine transporter activity.

Methods: Mice and rats were used to see how they react to the drug 419 and control vehicle, in each of the models. The animals were assessed to pre- and post- drug administration of novel drug 419. We examined each model to see the association between how drug 419 will help with treating drug abuse.

Results: We found that in alcohol consumption model the …

Ethanol Induced Neurotoxicity Through Dysregulation Of Ampk In A Fetal Alcohol Syndrome Model, Jessica Gebhardt

Theses and Dissertations--Medical Sciences

Ethanol consumption during pregnancy is rising in the U.S., including the rate of binge drinking. It is reported around 1 in 27 women engage in binge drinking activities while pregnant. The third trimester is a sensitive period of neuronal growth in which ethanol induced neurotoxicity can cause many harmful effects including Fetal Alcohol Spectrum Disorders. It has been shown that ethanol decreases the activity of AMPK through increasing lipid peroxidation, both of which are correlated to neurotoxicity. AICAR is a synthetic analog of AMP which significantly increases AMPK activity and may have beneficial effects in an organotypic hippocampal model of …

The Stimulation Of Dendritic Cells By Cationic Lipids, John Peyton Bush

Theses and Dissertations--Medical Sciences

The discovery that cationic lipids can independently stimulate the immune system has generated interest in their potential as vaccine adjuvants. Here, we show that the cationic lipid R-DOTAP can independently stimulate type 1 interferon production in dendritic cells in both primary culture and immortalized cell culture. Levels of type 1 interferon production are cell line-dependent and limited in vitro by lipid-induced cell death. We show that cationic lipids can independently activate TLR-7 and TLR-9, suggesting a mechanism for type 1 interferon induction. This TLR-stimulatory activity is not restricted to R-DOTAP and can be extended to other similar cationic lipids in …

Myosin-Xva Is Key Molecule In Establishing The Architecture Of Mechanosensory Stereocilia Bundles Of The Inner Ear Hair Cells, Shadan Hadi

Theses and Dissertations--Medical Sciences

Development of hair cell stereocilia bundles involves three stages: elongation, thickening, and supernumerary stereocilia retraction. Although Myo-XVa is known to be essential for stereocilia elongation, its role in retraction/thickening remains unknown. We quantified stereocilia numbers/diameters in shaker-2 mice (Myo15^sh2) that have deficiencies in “long” and “short” isoforms of myosin-XVa, and in mice lacking only the “long” myosin-XVa isoform (Myo15^ΔN). Our data showed that myosin-XVa is largely not involved in the developmental retraction of supernumerary stereocilia. In normal development, the diameters of the first (tallest)/second row stereocilia within a bundle are equal and grow simultaneously. …

The Effects Of Exercise Preconditioning On Focal Ischemic Stroke, Gillian Grohs

Theses and Dissertations--Medical Sciences

Cleaved fragments of the extracellular matrix protein perlecan have been shown to promote neuroprotection and repair after ischemic stroke. The cysteine proteases cathepsin B and L as well as the metalloprotease bone morphogenic protein 1 (BMP-1) are capable of releasing the biologically active C-terminal laminin-like globular domain (LG3) of perlecan. Exercise, a known method of reducing stroke risk and severity, has been shown to increase the expression of some proteases associated with perlecan processing. Using a transient distal middle cerebral artery occlusion (MCAo) model for focal ischemic stroke we show that while 7 days of running only slightly decreased infarct …

Cerebrovascular Risk Factors, Arteriolar Sclerosis, And Cognitive Decline In The Kentucky Appalachian “Stroke-Belt”, Omar M. Al-Janabi

Theses and Dissertations--Medical Sciences

The relationship between cerebrovascular disease (CVD) risk factors and cognitive impairment or dementia has been widely studied with significant variability in findings between groups. We hypothesized that chronic small vessel injury in the form of arteriolar sclerosis, measured quantitatively using MRI to measure total white matter hyperintensity (WMH) volumes, would identify specific association of CVD risk factors and patterns of cognitive decline, associated with mild cognitive impairment of the cerebrovascular type, that represent the core features of vascular cognitive impairment in our cohort.

A Cross-sectional analysis of clinical and quantitative MRI data on 114 subjects with normal cognitive function (n=52) …

Evaluating The Use Of Second LifeTm For Virtual Team-Based Learning In An Online Undergraduate Anatomy Course, Christena Gazave

Theses and Dissertations--Medical Sciences

Team-based learning (TBL) is one strategy for improving team-work and critical thinking skills. It has proven to be an engaging teaching pedagogy in face-to-face classes, however, to our knowledge, has never been implemented online in a 3-D virtual world. We implemented virtual TBLs in an online undergraduate anatomy course using Second Life^TM, and evaluated whether it engaged students. This study was conducted over 2 semesters with 39 total students. Surveys and content analysis of transcripts were used to evaluate student engagement. Our results indicate virtual TBLs were engaging for most students. The average engagement score was 7.8 out …

Listeria Monocytogenes Can Utilize Both M Cell Transcytosis And Inla-Mediated Uptake To Cross The Epithelial Barrier Of The Intestine During An Oral Infection Model Of Listeriosis, Hilary Denney

Theses and Dissertations--Medical Sciences

The invasive pathways, InlA- and InB-mediated uptake and M cell transcytosis, that Listeria monocytogenes uses to invade the intestine have mainly been studied using infection models that do not truly replicate what occurs during a natural infection. Recently, our lab has developed an oral infection model that is more physiolocally relevant to what occurs during food borne listeriosis. We have sought to evaluate the relative roles of the previously defined invasive pathways, in our oral model of infection. We have done this by utilizing an InlAmCG Lm strain that is able to bind murine E-cadherin, knockout Lm strains, ΔinlA Lm …

Immobilizing Mutation In An Unconventional Myosin15a Affects Not Only The Structure Of Mechanosensory Stereocilia In The Inner Ear Hair Cells But Also Their Ionic Conductances, Diana Syam

Theses and Dissertations--Medical Sciences

In the inner and outer hair cells (OHCs) of the inner ear, an unconventional myosin 15a localizes at the tips of mechanosensory stereocilia and plays an important role in forming and maintaining their normal structure. A missense mutation makes the motor domain of myosin 15a dysfunctional and is responsible for the congenital deafness DFNB3 in humans and deafness and vestibular defects in Shaker-2 (Sh2) mouse model. All hair cells of homozygous Shaker-2 mice (Myo15^sh2/sh2) have abnormally short stereocilia, but, only stereocilia of Myo15^sh2/sh2OHCs start to degenerate after the first few days of postnatal development …

Glutamate Dysregulation And Hippocampal Dysfunction In Epileptogenesis, Seth R. Batten

Theses and Dissertations--Medical Sciences

Epileptogenesis is the complex process of the brain developing epileptic acitivity. Due to the role of glutamate and the hippocampus in synaptic plasticity a dysregulation in glutamate neurotransmission and hippocampal dysfunction are implicated in the process of epileptogenesis. However, the exact causal factors that promote epileptogenesis are unknown.

We study presynaptic proteins that regulate glutamate neurotransmission and their role in epileptogenesis. The presynaptic protein, tomosyn, is believed to be a negative regulator of glutamate neurotransmission; however, no one has studied the effects of this protein on glutamate transmission in vivo. Furthermore, evidence suggests that mice lacking tomosyn have a …