Life Sciences Commons^™

The Roles Of Fabp3 In Endothelial Dysfunction And The Transcriptomic Insights Into Cardiovascular Disease, Chi Hien Nguyen

Electronic Thesis and Dissertation Repository

Heart-type fatty acid binding protein (FABP3) is an effective biomarker for cardiac injuries. However, it has also been tested as a biomarker in patients with peripheral artery diseases; these conditions are complications of atherosclerosis, which is driven by endothelial dysfunction. As FABP3 release is not exclusive to the heart but appears to characterize cardiovascular events, whether FABP3 influences endothelial function is not known. Additionally, the transcriptomic profiles of endothelial cells during cardiovascular stresses remain under-investigated. This thesis investigates the multifaceted role of FABP3 and the transcriptomic alterations in endothelial cells under different cardiovascular stressors, offering novel insights into endothelial dysfunction …

Identification And Characterization Of Isoflavone Reductase Family Members In Soybean, Negin Azizkhani

Electronic Thesis and Dissertation Repository

Soybean’s yield is threatened by Phytophthora sojae, a pathogen responsible for stem and root rot disease. Glyceollins, unique antimicrobial agents specific to soybeans in partially preventing P. sojae infection, are derived from the isoflavonoid branch of the general phenylpropanoid pathway. One pivotal enzyme exclusively involved in glyceollin synthesis in soybean is the isoflavone reductase (GmIFR), which catalyzes the 2'-hydroxydaidzein conversion to 2'-hydroxy-2,3-dihydrodaidzein as a precursor for glyceollin biosynthesis. To comprehensively identify all members of the GmIFR gene family within the soybean genome, keyword and blast protein searches were conducted, identifying 98 putative GmIFRs. Among these candidates, …

Sufu In Shh Signalling Mediated Myogenesis, Suleyman Abdullah

Electronic Thesis and Dissertation Repository

Myogenesis is defined as the formation of skeletal muscle tissue during embryonic development and involves a multitude of cellular signalling pathways. Among these include the Sonic hedgehog (Shh) signalling pathway which must be deactivated for differentiation into muscle cells to occur. However, less is known regarding the pathways operation during cell differentiation and whether Suppressor of Fused (SUFU), the protein inhibitor of Shh signalling, plays a role. To address this, mouse C2C12 myoblast cells were utilized as a model and differentiated into muscle cells to identify the presence of SUFU during this time. Experiments in qRT-PCR show a decrease in …

Selective Activation Of Thrombin Activatable Fibrinolysis Inhibitor (Tafi) Attenuates Metastatic And Angiogenic Capabilities Of Melanoma And Lung Carcinoma In Vitro, Jacklyn Krizsan

Electronic Thesis and Dissertation Repository

Metastasis and angiogenesis are hallmarks of aggressive cancers, both depending on degradation of extracellular matrix by proteases such as plasmin. Plasmin activation is inhibited by thrombin-activatable fibrinolysis inhibitor (TAFI)-mediated cleavage of terminal lysine residues on plasminogen receptors. Activation of TAFI is most effectively done in complex with thrombomodulin (TM). TM is known to have anti-cancer properties, but it is not known if this is due to TAFI activation or an alternative substrate protein C (PC). We hypothesize that specific promotion of TAFI activation with TM treatment will attenuate metastatic and angiogenic capabilities of tumour cells.

Melanoma and lung carcinoma cells …

Elucidating The Biomechanics Of Mertk-Mediated Efferocytosis, Brandon Hayato Dickson

Electronic Thesis and Dissertation Repository

Macrophages are key mediators of efferocytosis – the phagocytic engulfment and removal of apoptotic cells. During engulfment, the coordinated activity of efferocytic receptors induces the remodeling of the actin cytoskeleton, which facilitates the envelopment of the cell by the plasma membrane. Mer receptor tyrosine kinase (MERTK) is a crucial efferocytic receptor, but its role during actin remodeling is not well understood. Previously, our lab showed that MERTK is an activator of β₂ integrins – which are comprised of receptors known to induce the actin polymerization that is required for engulfment. We hypothesized that MERTK is an indirect stimulator of …

Recovery From Social Isolation In Drosophila: The Role Of Dopamine And The Autism-Related Gene Nlg3., Ryley T. Yost

Electronic Thesis and Dissertation Repository

Within a group, individuals establish their preferred distance from each other, or social space, a form of social behaviour. The resulting distance depends on the exchange of social cues from others that needs to be perceived and integrated within the organism’s neural circuitry. In humans, social spacing can be impaired in neuropsychiatric disorders such as autism and schizophrenia. When organisms are subject to social isolation, profound changes in social behaviour are observed in a variety of species from insects to mammals, including social space. However, the genetic and molecular mechanisms modulating a behavioural response to isolation and possible recovery remain …

Effects Of High Glucose On Autophagy And Apoptosis In Preimplantation Mouse Embryo Culture, Virginia Wolfe

Electronic Thesis and Dissertation Repository

Maternal diabetes increases congenital malformations due to teratogenic effects of glucose on the developing embryo. High glucose culture alters preimplantation embryo development and is associated with increased oxidative stress. Apoptosis and autophagy are programmed cell death and survival mechanisms induced by oxidative stress, but their role in preimplantation diabetic embryopathy is poorly elucidated. It was hypothesized that high glucose culture would alter autophagic and apoptotic responses, and that they are dependent on the timing of high glucose culture initiation. Embryos were cultured with 0.2 mM (control) or 25 mM (high glucose) of D-glucose starting from the early (36 hpi) or …

Chromatin Regulation By Rb-Interacting Proteins In Cellular Immune Functions, Seung June Kim

Electronic Thesis and Dissertation Repository

The retinoblastoma protein (RB) is historically known for its function in cell cycle control. However, mice carrying targeted Rb1 mutations have revealed that RB serves various non-cell cycle control roles. Notably, RB acts as a scaffold that recruits chromatin regulatory proteins, condensin II and enhancer of zeste homolog 2 (EZH2). These complexes protect the genome integrity through maintaining proper chromosome condensation, long range contacts, and transcriptionally repressive histone modification. This thesis explores the mechanistic links that regulate such RB-condensin II complex or that are leveraged upon pharmacological inhibition of the RB-EZH2 complex. First, I identified potential phosphorylation sites in the …

Regulation Of Hedgehog And Wnt Signaling In Neural Differentiation Of P19 Embryonal Carcinoma Cells, Danielle Margaret Spice

Electronic Thesis and Dissertation Repository

The Hedgehog (Hh) and Wnt protein signaling pathways are essential in the differentiation of neurons and astrocytes. As there are many known and new players involved in regulating these pathways, the role of the regulators Suppressor of Fused (SUFU) and Never in Mitosis Kinase 2 (Nek2) have either not been previously reported or have not been thoroughly explored. To address this shortfall CRISPR gene editing was used to target SUFU and Nek2 in the mouse P19 embryonal carcinoma cell model of neural differentiation. Hh and Wnt signaling were explored in normal P19 neural differentiation, which occurs in the presence of …

Tracing The Fate Of Cytokeratin 19+ Cells During Beta Cell Regeneration Stimulated By Multipotent Stromal Cell-Secreted Effectors, Nazihah Rasiwala

Electronic Thesis and Dissertation Repository

Human bone marrow-derived multipotent stromal cells expanded under Wnt pathway stimulation secrete beta cell-regenerative factors collected as conditioned media (Wnt+ CdM). We used the cytokeratin 19 (CK19)-CreERT Rosa26-mTomato lineage tracing mouse to observe CK19+ cell conversion to insulin+ beta cells following intra-pancreatic injection of Wnt+ CdM. Tamoxifen treatment in mice induced labelling of CK19+ ductal and acinar cells with tdTomato and streptozotocin (50 mg/kg/day x 5 days) induced hyperglycemia. Injection of Wnt+ CdM preserved beta cell mass, reduced non-fasted blood glucose levels, and improved glucose tolerance over a 28-day period compared to controls. Insulin+/tdTomato+ cells in mice given Wnt+ CdM …

Rhamm As A Biomarker And Therapeutic Target In Triple-Negative Breast Cancer, Britney Messam

Electronic Thesis and Dissertation Repository

Triple-negative breast cancer (TNBC) is a heterogeneous group of tumours characterized by early metastases and poor prognosis. Discovering novel biomarkers and therapeutic targets is necessary to improve TNBC patient outcomes as resistance to chemotherapy, the main therapeutic approach for TNBC, is common. In my study, RHAMM promoted proliferation of TNBC MDA-MB-231 tumour cells. RHAMM expression increased sensitivity to doxorubicin (p=0.0002) and strongly increased sensitivity to the FDA-approved MEK1/2 inhibitor trametinib (p≤0.0001). Doxorubicin and trametinib selectively killed RHAMM^+/+ MDA-MB-231 tumour cells grown as co-cultures with RHAMM^-/- MDA-MB-231 tumour cells. RHAMM-loss or trametinib decreased phosphorylated ERK1/2 protein levels and …

Extrinsic And Intrinsic Factors Influencing Homeostasis And Repair In Oral Tissues, Georgia Nikoloudaki

Electronic Thesis and Dissertation Repository

The oral tissues, including gingiva and buccal mucosa, heal rapidly with minimal scar formation. Although in the oral cavity, the palatal mucosa is associated with excessive scarring in response to injury. In this thesis, first, I investigated the complex relationship between cells and their microenvironment using wound healing models in which extracellular matrix composition and mechanical stiffness affect cellular responses during acute wound repair. I also determined how intrinsic differences of cells recruited during healing contribute to wound resolution.

In Chapter 2, I first investigated cell-extrinsic factors, specifically the influence of the pro-fibrotic matricellular protein periostin on palatal healing. Using …

The Role Of Reactive Oxygen Species In The Accumulation Of Driver Mutations In B Cell Acute Lymphoblastic Leukemia, Mia P. Sams

Electronic Thesis and Dissertation Repository

B cell acute lymphoblastic leukemia (B-ALL) is the most prevalent type of cancer in young children and is associated with recurrent mutations and high levels of reactive oxygen species (ROS). The antioxidant N-acetylcysteine was tested for its ability to prolong lifespan of a mouse model of B-ALL and reduce frequency of mutations. Mice treated with 1g/L of N-acetylcysteine in drinking water were found to have delayed onset of B-ALL at 11 weeks of age and changes in gene expression relating to B cell development, calcium-apoptosis signaling, and pathways in cancer, although no differences in lifespan were observed. Tumours from treated …

Characterization Of Galectin-16 Expression And Function In Placental Cells, Jennifer Kaminker

Electronic Thesis and Dissertation Repository

The processes of cellular differentiation and apoptosis are critical for placental development. The galectin-16 gene (LGALS16) is associated with these processes in the placenta, but the mechanism by which it acts is poorly characterized. My bioinformatics analysis revealed that LGALS16 expression was limited to specific tissues including the placenta and identified multiple regulatory molecules (transcription factors and miRNAs), which could potentially control relevant transcriptional and post-transcriptional mechanisms. Considering the predominant expression of LGALS16 in placenta, I examined the expression, regulation, and function of LGALS16 in BeWo and JEG-3 cell lines representing in vitro models of trophoblast differentiation. In …

The Effect Of Maternal Immune Activation On Placental And Fetal Development In Rats, Kelly J. Baines

Electronic Thesis and Dissertation Repository

Development of the placenta and embryo is a highly orchestrated process that is vulnerable to changes in the in utero environment. Maternal immune activation (MIA) during pregnancy is a major risk factor for many obstetric complications and predisposes offspring to growth restriction as well as cognitive and neurobehavioral deficits; however, the mechanisms underlying these risks remain unknown. In this thesis, I aimed to determine the effect of MIA on development of the placenta and fetal brain. By administering the viral mimetic polyinosinic:polycytidylic acid to pregnant rats as a model of MIA, I demonstrated that a maternal antiviral response is associated …

Illuminating Transfer Rna Variants As Genetic Modifiers In Models Of Human Disease, Jeremy T. Lant

Electronic Thesis and Dissertation Repository

Transfer RNAs (tRNAs) physically link the genetic code to an amino acid sequence, by recruiting amino acids to three-nucleotide codons in messenger RNAs. To ensure that the genetic code is translated as intended, tRNAs must be accurately aminoacylated and faithfully recognize codons in the ribosome during protein synthesis. Given the critical function of tRNAs, it has often been assumed that mutations in human tRNA genes would be either lethal to cells or not significantly impair tRNA function. My goal was to rigorously test this assumption in mammalian cell models, prompted by the recent discovery of unprecedented variation in human tRNA …

Connexin 43 Contributes To Phenotypic Variability Of The Mouse Skull, Elizabeth Jewlal

Electronic Thesis and Dissertation Repository

The purpose of this study was to determine whether connexin 43 (Cx43) contributes to craniofacial phenotypic variability. Skull shape and variation were compared within and among two heterozygous mutant mouse models (G60S/+ and I130T/+) that exhibit different levels of Cx43 channel function when compared to their wildtype counterparts (~80% and ~50% reduction in function, respectively). Results indicated mutants have significant differences in skull shape compared to wildtype littermates. Similar patterns of shape difference were found in both mutants. Increased skull shape variation and a disruption in the covariation of skull structures were observed in G60S/+ mutants only. These results show …

Spatiotemporal Characterization Of The Prr12 Paralogues In Zebrafish, Renee Jeannine Resendes

Electronic Thesis and Dissertation Repository

Pathogenic variants in the human PRR12 (Proline Rich 12) gene are associated with PRR12-related Neuroocular Syndrome. However, little is known about the gene/protein function. The zebrafish was utilized to address this, as its attributes place it as a premier model to study genes involved in human development and disease. In situ hybridization and RT-PCR of embryos and larvae, and qRT-PCR of adult tissues revealed the spatial and temporal distributions of the prr12 paralogues: prr12a and prr12b. Both paralogues were detected from the maternal and zygotic transcriptomes in a global and diffuse expression pattern, and there was enrichment …

Understanding The Kinomic Contributions To Tyrosine Kinase Inhibitor Resistance In Triple Negative Breast Cancer, Cory Lefebvre

Electronic Thesis and Dissertation Repository

Resistance to tyrosine kinase inhibitors (TKIs) presents a growing challenge in the development of therapeutic targets for cancers such as triple negative breast cancer (TNBC), where conventional therapies are ineffective at combatting systemic disease. Potential targets in TNBC include the receptor tyrosine kinases EGFR (epidermal growth factor receptor) and c-Met, however, targeted anti-EGFR and anti-c-Met therapies have faced challenges in clinical trials due to acquired resistance. We hypothesize that response versus resistance of triple negative breast cancer to the tyrosine kinase inhibitors erlotinib and cabozantinib is mediated by compensatory changes in the kinome and phosphoproteome. To test this, we (1) …

Metabolic Regulation During Extraembryonic Endoderm Differentiation, Mohamed Gatie

Electronic Thesis and Dissertation Repository

The inner cell mass undergoes orchestrated cellular divisions resulting in the formation of the epiblast (EPI) and primitive endoderm (PrE). Understanding the process of cell fate specification is crucial to appreciate the intricacies of proper embryonic development. While the mouse embryo is an excellent model, limitations do exist with number, technical challenges, and accessibility, therefore, in my thesis I employed two cell-based models to recapitulate the EPI-PrE fate in vitro. Many signaling pathways have been implicated in this lineage decision, metabolism and its downstream products have been recently regarded as a driver of lineage commitment. Using various biochemical, molecular, …

Kindlin-1 Is Involved In Spreading, Migration, And Protein Regulation In Epidermal Scc-13 Cells, Naomi Mishan

Electronic Thesis and Dissertation Repository

Kindlin-1 is a scaffold protein linking the cytoskeleton to the extracellular matrix. Loss of function mutations in the FERMT1 gene (encoding Kindlin-1) cause gastrointestinal and skin defects associated with increased susceptibility to aggressive epidermal squamous cell carcinoma (SCC). This study investigated the consequences of targeted FERMT1 inactivation in the SCC-13 cell line of epidermal SCC. My studies demonstrate Kindlin-1 is not essential for SCC-13 proliferation or clonogenic potential in culture. Kindlin-1 was required for cell spreading on collagen I, but not on laminin-332, and its absence enhanced SCC-13 directional migration. Finally, I identified several proteins involved in tumor formation and …

Insights Into O-Glcnac-Mediated Regulation Of Galectin Expression And Secretion In Promyelocytic Hl-60 Cells, Adam J. Mctague

Electronic Thesis and Dissertation Repository

Galectins are a family of -galactoside-binding proteins involved in cell stress responses and differentiation. Galectins are multifunctional proteins widely studied in many cell models including acute myeloid leukemia HL-60 cells where they mediate numerous intra- and extracellular functions in response to many stress-inducing stimuli. O-GlcNAcylation is a dynamic post-translational modification implicated in the regulation of many cellular diseases including cancers. The O-GlcNAc mediated expression and secretion of galectins during neutrophilic differentiation was examined in HL-60 cells. Galectin gene (LGALS), galectin protein expression, and galectin secretion were determined by RT-qPCR, immunoblotting, and ELISA, respectively. Inhibition of O-GlcNAcylation induced markers of differentiation …

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 …

Investigation Of Β5 Integrin Function In Epithelial Ovarian Cancer Cell Adhesion And Metastatic Properties Of Spheroids, Dolly Dhaliwal

Electronic Thesis and Dissertation Repository

Epithelial ovarian cancer (EOC) is the most lethal gynaecological malignancy in the developed world. EOC metastasis is unique since malignant cells detach directly from the primary tumor site into the abdominal fluid and form multicellular aggregates, called spheroids, that possess enhanced survival mechanisms while in suspension. As such, altered cell adhesion properties are paramount to EOC metastasis with cell detachment from the primary tumor, dissemination as spheroids, and reattachment to peritoneal surfaces for secondary tumor formation. These interactions play a crucial role in cell-cell and cell-extracellular matrix interactions, having implications in multiple steps of cancer progression. We previously showed that …

The Regulation Of Pannexin1 And Pannexin2 In The Skin In Health And Disease, Rafael E. Sanchez Pupo

Electronic Thesis and Dissertation Repository

Pannexins (PANX1, 2, 3) are a family of channel-forming glycoproteins that mediate intracellular and paracrine signaling. In contrast to PANX2, PANX1 has been extensively investigated in the skin, modulating cell differentiation, wound healing, and melanoma development. PANX1 and PANX2 can co-exist in the same cell and form mixed channels where their glycosylation seems to regulate their intermixing. N-glycosylation and caspase cleavage have been proposed as modulators of the function of PANX1, but their effects on PANX2 are unknown. We explored the PANX2 expression in mouse skin and showed that a Panx2 splice variant (PANX2-202) is continuously expressed throughout aging skin. …

Maternal Lifelong Western Diet Consumption Impacts Placental And Brain Development In The Term Guinea Pig Fetus, Carlene H. Cihosky

Electronic Thesis and Dissertation Repository

Both metabolic and cognitive dysfunction can originate from fetal reprogramming precipitating from adverse conditions experienced in utero. Of note is the western diet (WD), which is associated with maternal energy imbalances that may hinder fetal development through altered placental function. Brain-derived neurotrophic factor (BDNF), a growth factor that supports the placenta and developing brain, is responsive to such energy imbalances. This study sought to investigate the impact of lifelong maternal WD consumption on fetoplacental development, focusing on relations between placental changes, and fetal growth and neurodevelopment in a guinea pig model. Maternal WD consumption resulting in a lean metabolically …

The Effects Of Decellularized Adipose Tissue Constructs On Mesenchymal Stromal/Stem Cell Phenotype And Pro-Angiogenic Secretory Function., Yehia Moharrem

Electronic Thesis and Dissertation Repository

Due to limited treatment options for critical limb ischemia (CLI), cellular-based therapies have been investigated to induce blood vessel regeneration. Bone marrow-mesenchymal stromal/stem cells (BM-MSC) have shown pre-clinical success in animal models of CLI as they possess pro-angiogenic and immunomodulatory functions. However, clinical translation has been hindered by inadequate expansion and delivery strategies. This project aimed to characterize the phenotype and pro-angiogenic secretory function of BM-MSC on decellularized adipose tissue (DAT) bioscaffolds as expansion platforms. Compared to cells grown on tissue-culture plastic, DAT substrates supported BM-MSC growth, regenerative marker expression, and pro-angiogenic secretory function. Conditioned media generated by BM-MSC cultured …

Characterization And Modulatory Influence Of Pyruvate Kinase Muscle Isoforms 1 And 2 Within The Murine Pluripotent Continuum, Joshua G. Dierolf

Electronic Thesis and Dissertation Repository

Mouse embryonic stem cells (mESCs) and mouse epiblast stem cells (mEpiSCs) represent opposite ends of a pluripotency continuum, respectively referred to as naïve and primed pluripotent states. A third, recently discovered intermediate state has been described as the ‘formative state’. Metabolism has been traditionally regarded as a by-product of cell fate; however, recent evidence now supports metabolism as promoting stem cell fate. Pyruvate kinase muscle isoforms 1 and 2 (PKM1 and PKM2) catalyze the final, rate limiting step of glycolysis generating adenosine triphosphate (ATP) and pyruvate; however, the precise role(s) of these isozymes in naïve, formative, and primed pluripotency is …

Characterizing The Effects Of Pyrroloquinoline Quinone (Pqq) Supplementation On Skeletal Muscle Mitochondrial Function And Myogenesis During Oxidative Stress And Iugr., Allyson J. Wood

Electronic Thesis and Dissertation Repository

Intrauterine growth restriction (IUGR) affects 10-15% of births and is associated with placental insufficiency (PI), resulting in fetal oxidative stress (OS). This OS is a factor in the predisposition to postnatal noncommunicable disease (NCD) of which muscle mitochondrial dysfunctional is a key aspect. Pyrroloquinoline quinone (PQQ), an antioxidant-like compound, is capable of OS reduction and promotes mitochondrial function, though limited research has focused on its effects in in utero skeletal muscle. This study sought to investigate the impact of in vitro H₂O₂, a model of OS, and an in vivo model of OS associated IUGR, with …

Nrf2 Regulation By Hsp90, Oxidation, And In Breast Cancer, Vy Ngo

Electronic Thesis and Dissertation Repository

To cope with the dynamic range of stressful stimuli that a cell experiences within its lifetime, a host of adaptive cell survival and cell stress response pathways have evolved. The antioxidant and heat shock responses are two key cell stress response pathways primarily involved in the detoxification and elimination of oxidative stress and the maintenance of protein integrity, respectively. Traditionally, these responses are regarded and studied as two independent pathways. In this exploratory work, we hypothesize that oxidative damage to Nrf2 and Keap1 and their interactions with Hsp90 alter their function within the cellular antioxidant stress response. By establishing and …