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Junctophilin-2 Protects Cardiomyocytes Against Palmitate-Induced Injury, Xiaoyun Ji

Electronic Thesis and Dissertation Repository

Cardiac lipotoxicity may induce cardiomyocyte apoptosis, eventually leading to myocardial dysfunction and heart failure. This study investigated whether and how junctophilin-2 (JPH2) plays a role in palmitate-induced apoptosis in cardiomyocytes. Here, we found palmitate incubation reduced JPH2 protein levels, increased cytosolic Ca²⁺ and induced apoptosis in cardiomyocytes. JPH2 over-expression prevented the increased cytosolic Ca²⁺ and apoptosis in palmitate-stimulated cardiomyocytes. JPH2 over-expression also attenuated palmitate-induced CCAAT-enhancer-binding protein homologous protein (CHOP) expression and CHOP deletion alleviated palmitate-induced apoptosis. Furthermore, blocking Ca²⁺ release from ryanodine receptor-2 (RyR2) prevented palmitate-stimulated CHOP induction and apoptosis. Additionally, JPH2 silencing elevated cytosolic Ca^{2+ …}

The Difference In A1c Of Children And Adolescents With Type 1 Diabetes Mellitus Using Carbohydrate Counting Compared To Those Using A Structured Meal Plan, Alia El Kubbe

Electronic Thesis and Dissertation Repository

Carbohydrate counting (CHO) is a nutrition education tool used by patients with type 1 diabetes mellitus (T1DM). The primary objective was to assess glycated hemoglobin (A1C) in participants with T1DM using CHO counting vs. those using a structured meal plan (SMP). The secondary objectives were to determine if BMI-for-age, parental income, parental involvement, and mothers’ educational level were associated with their children’s glycemic control. A cross sectional study was conducted, where participants aged 4-18 years, or their parents completed a survey. Total sample size was 88 participants (77 in the CHO counting group and 11 in the SMP group). There …

Utilizing Fiv (Feline Immunodeficiency Virus) To Develop A Novel Animal Model To Study Hiv (Human Immunodeficiency Virus), Ankita Suryakant Kambli

Electronic Thesis and Dissertation Repository

This project sought to perform the in vitro work needed to accomplish the long-term vision of harnessing the similarities between HIV (Human Immunodeficiency Virus) and FIV (Feline Immunodeficiency Virus) to develop an animal model whereby cats can be used to study HIV pathogenesis and therapeutics. We transfected CRFK (Crandell Rees Feline Kidney) fibroblasts with plasmids that could express human or feline CD4, CCR5, or both, and determined receptor surface expression through flow cytometry. We discovered that HIV envelope expressed on 293T can fuse with huCD4/huCCR5 on CRFK. These cat cell lines were also capable of supporting HIV infection. Additionally, we …

Discovery Of Novel Mechanisms Regulating Cancer Extravasation In The Chorioallantoic Membrane Model, Yohan Kim

Electronic Thesis and Dissertation Repository

Cancer metastasis is a multistep process that begins with the invasion of tumour cells into the stroma and migration towards the blood vessels. Tumour cells that have entered the bloodstream must then survive and leave by a process known as extravasation. Finally, extravasated cells proliferate and establish the secondary site in the metastatic cascade. Although extravasation encompasses key events during cancer cell invasion to aid in the development of effective treatments, an in vivo model that rapidly, reproducibly and economically recapitulates cancer cell extravasation is needed. Therefore, the objectives of my research were to 1) establish and validate an in …

Effect Of N-Acetyl-L-Cysteine Prevention Or Intervention On Diet Induced Beta Cell Compensation And Dysfunction, Madison Wallace

Electronic Thesis and Dissertation Repository

Type 2 diabetes mellitus (T2DM) progression increases oxidative stress which contributes to beta cell compensation and eventual dysfunction. To investigate the role of antioxidant N-acetyl-L-cysteine (NAC) on beta cell function and pancreatic stellate cell activation (aSMA⁺) during early and late stages of compensation, NAC was used for preventative (p) and intervention (i) treatments in C57BL/6N mice fed a 60% kcal high-fat diet (HFD) for 8 or 22 weeks. Significantly improved glucose tolerance was observed at 22 weeks following pNAC treatment in HFD mice. Although 22-week HFD mice displayed hyperinsulinemia, beta cell hypertrophy, decreased beta cell PDX-1 nuclear localization, …

In Search Of Psychiatric Kinds: Natural Kinds And Natural Classification In Psychiatry, Nicholas Slothouber

Electronic Thesis and Dissertation Repository

In recent years both philosophers and scientists have asked whether or not our current kinds of mental disorder—e.g., schizophrenia, depression, bipolar disorder—are natural kinds; and, moreover, whether or not the search for natural kinds of mental disorder is a realistic desideratum for psychiatry. In this dissertation I clarify the sense in which a kind can be said to be “natural” or “real” and argue that, despite a few notable exceptions, kinds of mental disorder cannot be considered natural kinds. Furthermore, I contend that psychopathological phenomena do not cluster together into kinds in the way that paradigmatic natural kinds (e.g., chemical …

Virally Packaged Rna In Virus-Like Particle Vaccines Enhances Antigenicity And Augments Latency Reversal Of Hiv-1, Chanuka Wijewardhana

Electronic Thesis and Dissertation Repository

Introduction:

Since Human Immunodeficiency Virus (HIV)-1 was determined to be the etiological agent behind acquired immunodeficiency syndrome (AIDS) in 1983, numerous attempts at a cure have been made; however, none have been effective. One of the primary roadblocks in achieving a cure is a transcriptionally-silent latent reservoir of memory CD4+ T cells harboring HIV provirus. Combined antiretroviral therapy (cART) inhibits actively replicating virus by interfering with various stages of the replication cycle. Therefore, non-replicative viruses–like the proviruses found in latently infected cells–are hidden from the actions of continued antiretroviral therapy. As a result, cART discontinuation or treatment holidays can result …

Determining The Relative Transmission Fitness Of Hiv-1 Subtypes A, B, C, And D, Spencer Yeung

Electronic Thesis and Dissertation Repository

There is in vivo evidence that suggests the genetic diversity of HIV-1 subtypes influence heterosexual transmission efficiency. To recapitulate sexual transmission in vitro, blocks of genital tissue were exposed to mixtures of genetically different subtype viruses. Migrating immune cells were collected and co-cultured with a CD4+ T-cell line permissive to HIV infection (PM1) to measure dendritic cell virus transfer; HIV-exposed tissues were cultured separately. Next generation sequencing (NGS) of HIV-1 DNA was used to quantify relative infection rates of the various challenge viruses, and to assess fitness differences in infection of the tissue vs. migratory/T cell co-cultures. Our results …

Designing An Optimal Hiv-1 Env Immunogen For The Vesicular Stomatitis Virus Vaccine Platform And Elucidating The Role Of Hiv-1 Nef In Env Trafficking, Jason Knapp

Electronic Thesis and Dissertation Repository

Current vesicular stomatitis virus (VSV)-based HIV vaccines require an optimal HIV envelope immunogen to improve protection in vivo. Furthermore, the involvement of viral proteins, such as HIV Nef, in the trafficking of HIV Env to sites of viral assembly remains poorly understood and may provide additional insights for the design of a VSV-based HIV vaccine. We constructed new codon-optimized chimeric Env immunogens containing the signal sequence of honeybee melittin and the transmembrane and cytoplasmic tail domains of SIV, Zaire Ebola, or VSV glycoproteins. We showed that all chimeric Env immunogens had enhanced expression levels within producer cells. Utilizing bimolecular …

Investigation Of Visual Perceptions In Parkinson's Disease And The Development Of Disease Monitoring Software, Matthew Bernardinis

Electronic Thesis and Dissertation Repository

Non-motor Parkinson’s Disease (PD) symptoms are substantial factors of PD arising throughout disease stages, yet their diagnosis and monitoring remain a challenge. Sensory abnormalities in PD occur across sensory systems and disease stages, contributing to disease-related impairments. However, the extent of symptoms is unknown, with inadequate monitoring and treatment options furthering disease management difficulties. The current work studies movement-independent visual perceptions of time, displacement and velocity in PD patients across disease stages using levodopa, deep brain stimulation (DBS), or no PD therapy. Perceptual tasks were conducted using a computer-generated graphical device designed with a focus on simplicity and flexibility. Perception …

The Role Of Kidney Injury Molecule-1 In The Metastasis Of Renal Cell Carcinoma, Jasper Lee

Electronic Thesis and Dissertation Repository

Over 30% of patients with renal cell carcinoma (RCC) present with metastases, with median survival of 2 years. Kidney injury molecule 1 (KIM-1) is a cell-surface glycoprotein expressed by >90% of RCC tumours. Preliminary data mined from The Cancer Genome Atlas RNA-sequencing database indicates that KIM-1 overexpression predicts overall survival in patients. Here we sought to determine if tumour KIM-1 plays a role in RCC cell extravasation and metastasis to the lungs. In vitro invasion and in vivo metastasis assays were performed to investigate the metastatic potential of KIM-1-expressing cells, and RNA-seq was conducted to identify differentially expressed genes between …

Assessing The Structure-Function Relationships Of The Apolipoprotein(A) Kringle Iv Sub-Type 10 Domain, Matthew J. Borrelli

Electronic Thesis and Dissertation Repository

Elevated plasma lipoprotein(a) (Lp(a)) is the most prevalent heritable risk factor in the development of cardiovascular disease. The apolipoprotein(a) (apo(a)) component of Lp(a) is strongly implicated in the pathogenicity of Lp(a). It is hypothesized that the inflammatory potential of Lp(a)/apo(a) is mediated by the lysine binding ability of the apo(a) kringle IV10 (KIV10) domain, along with its covalently bound oxidized phospholipid (oxPL). Using targeted mutagenesis, two novel null alleles for the LPA gene that generate non-secretable apo(a) species have been identified, resulting from amino acid substitutions in the KIV10 domain. A potential mechanism by which KIV10 oxPL modification is enriched …

Differentiating The Substantia Nigra And Ventral Tegmental Area In Early-Stage Parkinson's Disease Using Iron Imaging, Erind Alushaj

Electronic Thesis and Dissertation Repository

Excessive midbrain iron accumulation in Parkinson’s Disease (PD) contributes to degeneration of the substantia nigra pars compacta (SNc) and ventral tegmental area (VTA). Despite this understanding, there are no validated PD biomarkers. Magnetic resonance imaging (MRI) can localize and quantify brain iron for diagnosis of PD. Seventeen early-stage PD patients and twenty-one controls were scanned at 3T and 7T MRI. Using quantitative susceptibility mapping (QSM) and R2* relaxometry, we analyzed the average iron content in the SNc, substantia nigra pars reticulata (SNr), and VTA. QSM detected significantly higher SNc iron content in PD patients compared to controls at both …

Neurodevelopmental Outcomes Of Infantile Hydrocephalus: An Fmri Case Study, Ikhlas Ahmed Hashi

Electronic Thesis and Dissertation Repository

Ventricle dilatation caused by infantile hydrocephalus may result in extensive damage of the posterior cortex (parietal and occipital lobes). We hypothesize that pathological changes in the development of the posterior cortex can be linked to non-verbal learning disabilities in children with previous infantile hydrocephalus. This case study will investigate the neurodevelopmental outcomes of 3 treated hydrocephalus patients, when compared to a group of healthy control children (n = 12). Within the hydrocephalus group, patients displayed differences in non-verbal test performance as well as parietal brain activation during an fMRI number comparison task. We associated these differences with clinical variables such …

Pregestational Diabetes Induced Congenital Heart Defects And Coronary Artery Malformations; Mechanisms And Preventative Therapies, Anish Engineer

Electronic Thesis and Dissertation Repository

Congenital heart defects (CHDs) arise from perturbations in complex molecular and cellular processes underlying normal embryonic heart development. CHDs are the most common congenital malformation, occurring in 1 to 5% of live births, and are the leading cause of pediatric mortality. Adverse genetic and environmental factors can impede normal cardiogenesis and increase the likelihood of CHDs. Pregestational maternal diabetes increases the risk of CHDs in children by more than four-fold. As the prevalence of diabetes rapidly rises among women of childbearing age, there is a need to investigate the mechanisms and potential preventative strategies for these defects. The aim of …

Microvascular Stenosis In Critical Limb Ischemia: Role Of Partial Endothelial To Mesenchymal Transition, Jacqueline M. Chevalier

Electronic Thesis and Dissertation Repository

Critical limb ischemia (CLI) is a widespread and debilitating manifestation of atherosclerosis. Unfortunately, revascularization strategies are often precluded or unsuccessful, resulting in amputation. A major reason for treatment failure is likely co-existing abnormalities in ­­the microvasculature. However, the specific microvascular defects present in end-stage PAD in humans remain unknown.

The purpose of this study was to delineate abnormalities in the microvascular wall in the critically ischemic skeletal muscle of patients with CLI.

To elucidate the microvascular landscape in CLI, we studied human tibialis anterior and gastrocnemius muscles harvested from below-knee amputations of 10 individuals with CLI. Control muscles are from …

Maternal Nicotine Exposure Induces Congenital Heart Defects In The Offspring Of Mice, Elizabeth Greco

Electronic Thesis and Dissertation Repository

Congenital heart defects are the most prevalent birth defect, and maternal cigarette smoking is a known risk factor. Nicotine replacement therapies are recommended to pregnant women who smoke to aid in smoking cessation, as this alternative is thought to be much safer compared to cigarette smoking. However, these products contain nicotine, and the safety of nicotine on the developing heart is not well known. In this thesis, a mouse model was used to test the hypothesis that maternal nicotine exposure (MNE) during pregnancy leads to congenital heart defects and coronary artery defects in the offspring of mice. MNE resulted in …

Improving The Assessment And Understanding Of Neurogenic Orthostatic Hypotension, Jacquie Baker

Electronic Thesis and Dissertation Repository

Neurogenic Orthostatic Hypotension (NOH) is a cardinal feature of autonomic failure. Patients with NOH experience a persistent and consistent drop in blood pressure when standing due to failure of the autonomic nervous system to reflexively increase sympathetic outflow. NOH affects individuals worldwide, presenting as both a primary feature (i.e. Multiple Systems Atrophy, Pure Autonomic Failure) and secondary to several common disorders including diabetes and Parkinson’s Disease. However, there are still several gaps in our overall understanding and assessment of patients with NOH. Therefore, the six studies presented in this thesis aimed to address some of these gaps in our current …

Identifying The Enzyme Involved In Vacuolar Atpase Acetylation During Doxorubicin-Induced Cardiotoxicity, Rebecca Dang, Tianqing Peng

Western Research Forum

Doxorubicin is an established anticancer medication infamous for its bright colouration and extremely toxic side effects. Emerging studies support that the imbalance between acetylation and deacetylation disrupts the autophagic flux leading to doxorubicin-induced cardiotoxicity. Vacuolar ATPases are a family of electrogenic proton pumps present on the lysosomal membrane that create an acidic environment for proteases to degrade proteins. Our preliminary study found that acetylated Vacuolar ATPase subunit V₀ D1 levels increased in doxorubicin-injected mouse hearts. However, it is unknown how acetylation of subunit V₀ D1 is modulated and whether this modification plays a role in doxorubicin-induced cardiotoxicity.

The …

Role Of Gp120 Glycosylation In Sexual Transmission Of Hiv, Yingxue Sun, Adam Meadows, Najwa Zebian, Eric Arts, Carole Creuzenet

Western Research Forum

Background:

In chronic HIV patients, the viral populations are genetically diverse due to mutations introduced by the viral reverse transcriptase during HIV replication. However, more than 80% new infections result from single transmission founder (TF) viruses; therefore, targeting the TFs is key to control AIDS worldwide.

Gp120 is a glycosylated envelope protein required for HIV infection, propagation, and transmission. Glycans on gp120 influence HIV infectivity through their interactions with lectins, the carbohydrate-binding immune proteins in the host mucosa. To transmit sexually, viruses must overcome the lectin traps to access more target T cells.

Hypothesis:

TF viruses are less likely to …

An Application Of The Modifiable Areal Unit Problem: Optimizing Cluster Method Parameters To Produce Predictive Data For Hiv Outbreaks, Connor J. Chato, Art Fy Poon

Western Research Forum

Background

A popular approach to study HIV outbreaks is to cluster cases based on genetic similarity. However, there is no widely-used statistical criterion which optimizes the parameters for sequence-based clustering methods. The relationship between a cluster-defining similarity threshold and it’s associated set of clusters can be analogized to the aggregation level in the Modifiable Areal Unit Problem (MAUP).

Hypothesis

Based on the selection of aggregation level for study partitions in MAUP, we present a statistical framework to optimize the similarity threshold for pairwise distance algorithm TN93 (http://github.com/veg/tn93). We hypothesize that defining this threshold includes case connections such that …

The Wet Bridge Transfer System: An Novel In Vitro Tool For Assessing Exogenous Surfactant As A Pulmonary Drug Delivery Vehicle, Brandon J. Baer

Western Research Forum

Background:

Due to its complex branching structure, direct drug delivery to the remote areas of the lung is a major challenge. Consequently, most therapies, such as those treating pulmonary infection and inflammation, must utilize large systemic dosing, with the potential for adverse side effects. A novel alternative strategy is to use exogenous surfactant, a material capable of distributing throughout the lung, as a pulmonary drug delivery vehicle.

Objective:

Utilize an in vitro transferring system to assess exogenous surfactant (BLES) as a pulmonary delivery vehicle for different therapeutics.

Methods:

An in vitro technique was developed to simultaneously study surfactant delivery and …

Yap-Mediated Mechanotransduction Promotes Fibrotic Activity, Michael Racanelli

Electronic Thesis and Dissertation Repository

Fibrosis, a phenotype associated with mortality for a multitude of diseases, has no disease-modifying treatment. We examine if Verteporfin (VP), an inhibitor of the YAP-TEAD complex, currently in wide clinical use for macular degeneration, can inhibit pro-fibrotic gene expression in human dermal fibroblasts. Also, an in vivo approach was taken using a Pten-deficient mouse of progressive skin fibrosis for examining effects on melanoma metastasis. We found that treatment with VP reduced basal expression of a variety of profibrotic genes and prevented a myofibroblast-like phenotype in response to TGFβ1. Indeed, genome-wide expression analysis suggested that VP inhibited a cluster of …

Apolipoprotein(A) Secretion Is Modulated By Sortilin, Proprotein Convertase Subtilisin/Kexin Type 9, And Microsomal Triglyceride Transfer Protein, Justin Clark

Electronic Thesis and Dissertation Repository

Elevated plasma lipoprotein(a) (Lp(a)) levels are a causal risk factor for cardiovascular disease (CVD), but development of specific Lp(a) lowering therapeutics has been hindered by insufficient understanding of Lp(a) biology. For example, the location of the noncovalent interaction that precedes the extracellular disulfide linkage between apolipoprotein(a) (apo(a)) and apolipoprotein B-100 (apoB-100) in Lp(a) biosynthesis is unclear. In this study we modulated known intracellular regulators of apoB-100 production and then assessed apo(a) secretion from human HepG2 cells expressing 17-kringle (17K) apo(a) isoform variants using pulse-chase analysis. Treating 17K-expressing HepG2 cells withproprotein convertase subtilisin-kexin type 9(PCSK9) significantly increased apo(a) secretion. Treating the …

Effects Of Niacin And Vitamin D On Endothelial Cell Angiogenic Function And Vascular Regeneration During Lipotoxicity, Kia Mae Peters

Electronic Thesis and Dissertation Repository

Observational studies have suggested an association between low levels of niacin and vitamin D and increased cardiovascular disease risk. Both vitamins have been shown to improve endothelial functions and vascular regeneration following vascular injury, however, it appears vitamin D may promote or inhibit neovascularization in a context-dependent manner. We hypothesized that supplementation of vitamin D alone and in combination with niacin, would improve endothelial cell function under lipotoxic conditions and promote revascularization and functional recovery in obese mice with ischemic injury. Matrigel assays, mRNA microarray analyses and growth rate assays were used to investigate angiogenic function of endothelial cells exposed …

Potential Role Of Extracellular Atp Released By Bacteria In Bladder Infection And Contractility, Behnam Abbasian

Electronic Thesis and Dissertation Repository

Urgency urinary incontinence (UUI), the result of conditions such as overactive bladder (OAB), could potentially be influenced by both commensal and urinary tract infection-associated bacteria. The sensing of bladder filling involves interplay between various parts of the nervous system eventually resulting in contraction of the detrusor muscle during micturition. Here we model host responses to various urogenital bacteria, firstly by using urothelial bladder cell lines and then with myofibroblast contraction assays. To measure responses, we examined calcium influx, gene expression and alpha smooth muscle actin deposition assays. We found that organisms such as Escherichia coli IA2 and Gardnerella vaginalis ATCC …

Hiv-1 Group M Subtype Fitness, Disease Progression, And Entry Efficiency, Colin M. Venner

Electronic Thesis and Dissertation Repository

Human immunodeficiency virus type 1 (HIV-1) emerged in the human population shortly after the turn of the 19th century. Distribution of HIV-1 across the globe over the past 30–35 years can be traced to founder events with primordial HIV strains from sub-Saharan Africa. Even considering the burden of HIV in Africa, our knowledge of HIV-1 disease is still largely limited to subtype B HIV-1, a strain responsible for 3 million infections in North America and Europe as compared to the 33 million that are infected with HIV-1 subtypes A, C, D, and circulating and unique recombinant forms.

This dissertation analyzes …

Ultra-High Field Magnetic Resonance Imaging For Stereotactic Neurosurgery, Jonathan Lau

Electronic Thesis and Dissertation Repository

Stereotactic neurosurgery is a subspecialty within neurosurgery concerned with accurate targeting of brain structures. Deep brain stimulation (DBS) is a specific type of stereotaxy in which electrodes are implanted in deep brain structures. It has proven therapeutic efficacy in Parkinson’s disease and Essential Tremor, but with an expanding number of indications under evaluation including Alzheimer’s disease, depression, epilepsy, and obesity, many more Canadians with chronic health conditions may benefit. Accurate surgical targeting is crucial with millimeter deviations resulting in unwanted side effects including muscle contractions, or worse, vessel injury. Lack of adequate visualization of surgical targets with conventional lower field …

Improving Material Mapping In Glenohumeral Finite Element Models: A Multi-Level Evaluation, Nikolas K. Knowles

Electronic Thesis and Dissertation Repository

An improved understanding of glenohumeral bone mechanics can be elucidated using computational models derived from computed tomography data. Although computational tools, such as finite element analysis, provide a powerful quantitative technique to evaluate and answer a variety of biomechanical and clinical questions, glenohumeral finite element models (FEMs) have not kept pace with improvements in modeling techniques or model validation methods seen in other anatomic locations. The present work describes the use of multi-level computational modeling to compare, develop and validate FEMs of the glenohumeral joint.

Common density-modulus relationships within the literature were evaluated using a multi-level comparative testing methodology to …

The Effect Of Sepsis On Cerebral Microvascular Blood Flow, Laura Mawdsley, Mamadou Diop, Chris G. Ellis

Western Research Forum

Background: Sepsis is a dysregulated host response to infection that affects 18 000 000 people worldwide, and over 325 000 000 dollars are spent treating sepsis in Canada every year. One of the symptoms of severe sepsis is an altered mental state, which is accompanied with a measured decrease in oxygen levels in the skeletal muscle microvasculature. It is hypothesized that his altered mental state is due to a lack of oxygenated blood reaching the brain.

Hypothesis: After the onset of sepsis, microvascular cerebral blood flow and oxygen levels in the blood will decrease. Onset of decreased blood flow in …