Cell Biology Commons^™

Deconstructing Brown Adipocyte Neogenesis In Brown And White Adipose Tissue, Rayanne Burl

Wayne State University Dissertations

Global incidence of Type 2 Diabetes (T2D) has reached epidemic proportions, and increasing evidence indicates that dysfunctional adipose tissue is an important contributor to the pathogenesis of T2D. Expanding brown adipocyte (BA) populations within adipose tissues through adrenergic activation improves energy balance and insulin sensitivity. In order to exploit this remodeling of adipose tissue for therapeutic benefit, we need to understand the mechanisms by which adrenergic signaling expand populations of BAs in vivo. These studies utilized single-cell RNA-sequencing and transgenic mouse models, in combination with single-molecule fluorescence in situ hybridization (smFISH) and immunoistochemical analysis, to study BA neogenesis in vivo. …

Determining The Effects Of Chemical Exposure On Hepatocyte Mitochondrial Networks And Cell Viability, Bethany Eaton

All Master's Theses

Mitochondria are cellular organelles that are becoming more recently studied. One of their main functions is the production of energy through cellular respiration, which is crucial to cell life. However, they are also associated with numerous disease states. It is hypothesized that reactive oxygen species (ROS), largely produced in mitochondria, induce oxidative stress and affect mitochondrial morphology along with cell viability. This study compares chemical exposure of menadione, an ROS producer, and phthalates (plasticizers) on two mouse hepatocyte cell lines to determine the effects they have on mitochondrial morphology and cell viability. Three experiments were performed to analyze the effects …

Understanding The Effects Of Embryonic Hyperglycemia On Retinal Development And Maintenance, Kayla Titialii-Torres

Theses and Dissertations--Biology

Hundreds of millions of people are affected by diabetes worldwide. Whether they are diagnosed with prediabetes or Type I or II diabetes, there are a variety of mechanisms in the pathogenesis of diabetes. Diabetes is a disease which consists of recurring states of hyperglycemia that can be difficult to manage due to either lack of insulin production or improper utilization of insulin. While these mechanisms of action differ, complications induced by diabetes occur in both poorly regulated Type I and II. Common complications of diabetes include nerve damage, kidney damage, and eye damage. Eye damage specifically is called diabetic retinopathy …

The Role Of Protein Tyrosine Phosphatase Receptor Type F In Intestinal Homeostasis And Colorectal Cancer, Ashley T. Skaggs

Theses and Dissertations--Molecular and Cellular Biochemistry

Protein phosphorylation defines one of the most important regulatory mechanisms in cell signaling. PTPRF, protein tyrosine phosphatase receptor type F, belongs to the class I R2A subfamily of protein tyrosine phosphatases (PTP). The overall objective of this dissertation is to investigate the molecular mechanisms by which PTPRF regulates normal and cancer stem cells by controlling Wnt signaling.

Dysregulation of Wnt signaling promotes the initiation and progression of colorectal cancer (CRC). We first determined the functional important of PTPRF in regulating Wnt signaling in CRC. Combining cell culture, 3D tumor organoid and xenograft models, results from our study establish PTPRF as …

A Multidisciplinary Characterization Of The Enzymology And Biology Of Reversible Glucan Phosphorylation In Toxoplasma Gondii , Robert Murphy

Theses and Dissertations--Molecular and Cellular Biochemistry

Toxoplasma gondii is an opportunistic, protozoan parasite of all warm-blooded animals, infecting roughly one-third of humans worldwide. Humans acquire infections by consuming T. gondii tissue cysts in undercooked meat or from oocysts shed in cat feces. Encysted parasites convert into rapidly growing tachyzoites that disseminate throughout the body, defining the acute phase of infection. Under host immune pressure, tachyzoites convert into bradyzoites that populate tissue cysts found in CNS or muscle tissue and persist for the lifetime of the host, defining the chronic phase of infection. Tissue cysts are responsible for transmission via carnivory, but also possess the ability to …

Development Of Novel Pyridazine Derivatives And Drug Delivery Systems Against Dengue, Janae A. Culmer

College of Graduate Studies: Theses & Dissertations

The lack of approved vaccines, medications and treatment regimens has significantly contributed to the rapid spread of mosquito-borne viruses such as Dengue and Zika virus. The complex immunopathology of these viruses presents limitations for the development and implementation of a definitive, safe and effective approach to combat infections.Previous research has demonstrated that vector control strategies such as the elimination of larval habitats, larviciding with insecticides, the use of biological agents and the application of adulticides have been unsuccessful in the reduction of viral transmission leading to the need for the continued development of antivirals. This research proposes an approach for …

Tissue And Sex-Specific Rna Editing During Induced Acute Inflammation, Claire E. Nichols

Graduate Theses/Dissertations

A-to-I RNA editing is a process where select adenosine (A) nucleotides are deaminated by an editing enzyme, ADAR, to become inosines (I) in RNA transcripts. RNA editing can affect the sequence of the encoded protein and the regulation of the RNA. ADAR1 also plays a role in regulating innate immunity and its expression is upregulated during inflammation. Current data on the effects of increasing ADAR1 on RNA editing is limited, and most studies are completed only in male animals. We are interested in expanding RNA editing data to include female animals. Lipopolysaccharide (LPS) was used to induce acute inflammation and …

Nutrient Scarcity And Cellular Cooperation In A Clonal Hydroid, Weam S. El Rahmany

Graduate Research Theses & Dissertations

Biological complexity forms when lower-level units (e.g., genes, cells, organisms) cooperatively band together. This complexity may be exemplified by multicellularity, the cooperation between the cells of the same species, or symbiosis, cooperation between the cells of different species. This cooperation is under continual threat, as defection, the opposite of cooperation, is favored by default by lower-level units (i.e., cells). Animal cancers may be the most well-known phenomena that exemplify the concept of cellular defection. Cancer cells have been shown to feature morphological and metabolic traits, developed through differential gene expression or mutations, that favor their growth at the cost of …

Xrcc4 And Mre11 Roles And Transcriptional Response To Repair Of Talen-Induced Double-Strand Dna Breaks, Ronald Benjamin, Atoshi Banerjee, Xiaogang Wu, Corey Geurink, Lindsay Buczek, Danielle Eames, Sara G. Trimidal, Janice M. Pluth, Martin R. Schiller

Health Physics and Diagnostic Sciences Faculty Research

Double-strand breaks (DSB) are one of the most lethal forms of DNA damage that, if left unrepaired, can lead to genomic instability, cellular transformation, and cell death. In this work, we examined how repair of transcription activator-like effector nuclease (TALEN)-induced DNA damage was altered when knocking out, or inhibiting a function of, two DNA repair proteins, XRCC4 and MRE11, respectively. We developed a fluorescent reporter assay that uses TALENs to introduce DSB and detected repair by the presence of GFP fluorescence. We observed repair of TALEN-induced breaks in the XRCC4 knockout cells treated with mirin (a pharmacological inhibitor of MRE11 …

An Antimicrobial Polydopamine Surface Coating To Reduce Biofouling On Telemetry Tags Used In Marine Conservation Practices, Ariana Smies

Dissertations, Master's Theses and Master's Reports

Satellite telemetry tags are used to track the migration patterns of large cetaceans. These tags penetrate the dermis and remain embedded in the underlying blubber tissue. As the dermis of cetaceans is host to a diverse microbiome, and it is impossible to clean the skin before implanting the devices, the potential for infection is increased when the tags penetrate through the skin. H₂O₂ is a potential antimicrobial agent that, in addition to showing broad-spectrum efficacy against gram-negative and gram-positive bacteria, can promote wound healing outcomes by promoting proliferative factors and peptides that protect against oxidative stress. However, …

Cell-Engineered Vesicles For Therapeutic Delivery And Immunomodulatory Applications, Khaga Neupane

Theses and Dissertations--Chemistry

Development of a new kind of drug delivery system (DDS) that could efficiently deliver therapeutics to the cell of interest would allow us to accomplish cell-specific drug delivery while eliminating systemic toxicity. Although nanocarriers including endogenously released extracellular vesicles (EEVs), liposomes, and small molecules seem to be promising drug delivery systems, biological challenges persist for their use in clinical applications. Here, we demonstrate nanovesicles engineered by fragmenting cellular membranes can be exploited as versatile DDSs for therapeutics delivery as well as immunomodulatory functions. Cell-engineered vesicles were produced by cavitating cells using nitrogen gas at high pressure followed by serial centrifugation. …

Protein Charge Parameters That Influence Stability And Cellular Internalization Of Polyelectrolyte Complex Micelles, Rachel A. Kapelner, Rachel S. Fisher, Shana Elbaum-Garfinkle, Allie C. Obermeyer

Advanced Science Research Center

Proteins are an important class of biologics, but there are several recurring challenges to address when designing protein-based therapeutics. These challenges include: the propensity of proteins to aggregate during formulation, relatively low loading in traditional hydrophobic delivery vehicles, and inefficient cellular uptake. This last criterion is particularly challenging for anionic proteins as they cannot cross the anionic plasma membrane. Here we investigated the complex coacervation of anionic proteins with a block copolymer of opposite charge to form polyelectrolyte complex (PEC) micelles for use as a protein delivery vehicle. Using genetically modified variants of the model protein green fluorescent protein (GFP), …

Alternative Splicing Regulates The Innate Immune Response To Viral Infection, Luke A. White

Graduate Student Theses, Dissertations, & Professional Papers

Rift Valley fever virus (RVFV) is a mosquito-borne RNA virus that infects humans and livestock in sub-Saharan Africa and the Arabian peninsula, causing disease ranging from a mild flu-like illness to liver damage, blindness, hemorrhagic fever, death, and, especially in livestock animals, high rates of abortive pregnancies. There is no approved vaccine for RVFV, and as a disease with a high rate of spread that causes severe illness, it is listed as a Category A pathogen by the USA CDC. A better understanding of RVFV’s molecular virology will be instrumental to combating RVFV as climate change causes its mosquito host …

Determining Haplotype Specific X Chromosome Inactivation State And Related Epigenetic Features In Female X-Linked Genes, Ariah Dawn Mackie

Cal Poly Humboldt theses and projects

Females with heterozygous X-linked mutations are prone to pseudo-haploinsufficiency because random X chromosome inactivation (XCI) silences one of their two X chromosomes. A prior study explored the theory that reactivating the silenced healthy allele could be a treatment for pseudo-haploinsufficient females. The next step was to evaluate this approach in a clinically relevant stem cell model of the rare neurological disease CDKL5 Deficiency Disorder (CDD). It was necessary to validate X-inactivation state with respect to CDKL5 allele expression in one of these models. We explored CDKL5 allele expression in two populations of CDD female patient-derived induced pluripotent stem cells (iPSCs) …

Regulation Of Ppp1r15a (Gadd34) And Ppp1r15b (Crep) Mrna Expression And Localization In The Unfolded Protein Response, Krithika Giresh

University of the Pacific Theses and Dissertations

The failure to balance protein synthesis, folding, and degradation in the endoplasmic reticulum (ER) leads to the accumulation of unfolded proteins, leading to ER stress. Cells respond to this stress by activating a response signaling pathway known as the Unfolded Protein Response (UPR). One of the branches of the UPR induces the phosphorylation of eIF2α (Eukaryotic Initiation Factor 2) to attenuate global protein synthesis, allowing for a chance to clear misfolded and unfolded proteins. This phosphorylation of eIF2α is opposed by a phosphatase, containing a catalytic subunit, Protein Phosphatase 1, and a scaffolding protein, either GADD34 or CReP. Inhibition of …

Elucidating The Role Of Kmt2d In Her2+ Breast Cancer, Emily Ma

Dissertations

Breast cancer is the second leading cause of cancer-related deaths among women in the US. Histone modifications are common epigenetic changes that have been implicated in several breast cancers, including HER2+ breast cancers. Current therapies, such as trastuzumab, block the HER2 receptor to reduce tumor growth. Unfortunately, HER2+ breast cancers have found ways to overcome these therapies, leading to tumor resistance, metastases, and poor survival outcomes. A better understanding of the underlying mechanisms contributing to HER2+ breast cancer resistance may lead to the discovery of novel therapeutic strategies to improve patient outcomes.One prognostic marker for poor survival in women with …

Identifying The Human Homologs Of Yeast Rab Proteins Ypt10 & Ypt11 And A Global-Scale Louse Endosymbiont Genome Variation, Nathaniel P. Smith

Theses and Dissertations

Amyotrophic lateral sclerosis (ALS) is a late-onset fatal neurodegenerative disease that causes loss of upper and/or lower motor neurons, and currently has no treatment or cure available. Over 90% of cases occur spontaneously with unknown causes, highlighting the complexity of the disease, and only 10% of cases are linked to heritable genetic mutations. Numerous ALS-linked genes are conserved through evolution, and model organisms may therefore provide opportunities to understand disease pathology at a molecular or cellular level, proving instrumental in identifying therapeutic targets. ALS subtype 8 (ALS8) is caused by an autosomal dominant P56S mutation in the VAPB gene that …

An Investigation Into The Mechanism Of Proteasome Dysfunction In Neurodegenerative Disease And The Biological Impact Of Proteasome Hyperactivation In C. Elegans, Raymond T. Anderson

Graduate Theses, Dissertations, and Problem Reports (ETD)

Aging is an inevitable process that occurs as humans grow older. It is characterized by the chronological accumulation of cellular damage over time leading to functional decline as an organism grows older. Several processes are thought to contribute to the aging phenomenon, but one of the most prolific of these is the disruption of protein homeostasis (proteostasis). The collapse of proteostasis can lead to accelerated aging and the development of age-related diseases including devastating neurodegenerative diseases (NDs) like Alzheimer and Parkinson disease. Virtually all NDs are characterized by the buildup of proteins in and around neurons resulting in neuronal death …