Tobin, Stephanie

Concentration-Dependent Effects of Cadmium on Mouse Angiogenesis In Vitro

Type:
Names:
Creator (cre): Knight, Caitlyn, Thesis advisor (ths): Kapron, Carolyn, Degree committee member (dgc): Tobin, Stephanie, Degree committee member (dgc): Huber, Robert, Degree committee member (dgc): West, Sarah, Degree granting institution (dgg): Trent University
Abstract:

Cadmium is a toxic metal that has detrimental effects on blood vessel development and function. To examine the effect of varying concentrations of cadmium on angiogenesis, two in vitro assays were used. First, developing yolk sac blood vessels were studied in gestation day 8 mouse embryos exposed to medium alone, 1.25, or 1.75 μM cadmium chloride (CdCl2). Embryos exposed to 1.25 μM cadmium experienced a significant increase in the number of vessels formed; however, they were smaller in size. Vessel morphology and signalling pathways were also investigated using the mouse aortic ring assay, with exposures of 0.0, 0.5, 1.0, 5.0, or 10.0 μM CdCl2. Samples exposed to 10 μM experienced a significant increase in vessel length. However, no significant differences in phosphorylated PTEN and AKT were observed. The results of this study suggest that low levels of cadmium may disrupt angiogenesis, particularly the development of the embryonic vasculature in the yolk sac.

Author Keywords: Angiogenesis, Cadmium, Embryonic Development, Teratogenicity, Vascular Development, Vasculogenesis

2024

Functional Role of 97R in Host Cell Modulation during Frog Virus 3 Infection

Type:
Names:
Creator (cre): Bansal, Lakshika, Thesis advisor (ths): Brunetti, Craig R, Degree committee member (dgc): Tobin, Stephanie, Degree committee member (dgc): Yee, Janet, Degree granting institution (dgg): Trent University
Abstract:

Frog virus 3 (FV3) belongs to the genus Ranavirus within the Iridoviridae family.Its 105,903 base genome encodes 98 open reading frames (ORFs), including ORF 97R, a putative apoptosis regulator sharing 31% structural similarity with the anti-apoptotic Bcl- 2 family protein, myeloid cell leukemia 1 (Mcl-1). 97R contains a BH1 domain, implicated in apoptosis regulation, and a predicted C-terminal transmembrane domain, which acts as a membrane-anchoring domain, localizing 97R to the ER membrane. To study its role in host cell modulation, 97R was cloned into a vector and transfected into HeLa cells. Immunofluorescence revealed a time-dependent decrease in Protein Disulfide Isomerase (PDI) in 97R-transfected cells. Immunoprecipitation and western blotting revealed that 97R interacts with Prohibitin 1 (PHB1), a host protein involved in apoptosis regulation. This research provides insight into the novel functional role of 97R in host cells, enhancing our understanding of how FV3 may manipulate its host.

Author Keywords: Bcl-2 protein family, frog virus 3, Iridoviridae, ORF 97R, Protein-protein interactions, Ranavirus

2025

Concentration-Dependent Effects of Cadmium on Mouse Angiogenesis In Vitro

Type:
Names:
Creator (cre): Knight, Caitlyn, Thesis advisor (ths): Kapron, Carolyn, Degree committee member (dgc): Tobin, Stephanie, Degree committee member (dgc): Huber, Robert, Degree committee member (dgc): West, Sarah, Degree granting institution (dgg): Trent University
Abstract:

Cadmium is a toxic metal that has detrimental effects on blood vessel development and function. To examine the effect of varying concentrations of cadmium on angiogenesis, two in vitro assays were used. First, developing yolk sac blood vessels were studied in gestation day 8 mouse embryos exposed to medium alone, 1.25, or 1.75 μM cadmium chloride (CdCl2). Embryos exposed to 1.25 μM cadmium experienced a significant increase in the number of vessels formed; however, they were smaller in size. Vessel morphology and signalling pathways were also investigated using the mouse aortic ring assay, with exposures of 0.0, 0.5, 1.0, 5.0, or 10.0 μM CdCl2. Samples exposed to 10 μM experienced a significant increase in vessel length. However, no significant differences in phosphorylated PTEN and AKT were observed. The results of this study suggest that low levels of cadmium may disrupt angiogenesis, particularly the development of the embryonic vasculature in the yolk sac.

Author Keywords: Angiogenesis, Cadmium, Embryonic Development, Teratogenicity, Vascular Development, Vasculogenesis

2024