Cell Biology Commons^™

Regulation Of Endoplasmic Reticulum Stress Sensitivity By Torc1 Signalling In Yeast, Khadija Ahmed, Patrick Lajoie

Western Research Forum

Incorrect folding of secretory proteins in the endoplasmic reticulum (ER) results in an aberrant accumulation of misfolded proteins (ER stress) and activates a coping mechanism known as the unfolded protein response (UPR). While the mechanisms of UPR activation have been well established, how it integrates with other stress responses remains unclear.

Given that TORC1 is an important regulator of cell growth during protein misfolding stress, we sought to investigate how TORC1 signalling acts in parallel with the UPR to regulate ER stress sensitivity. Our studies employ the budding yeast, Saccharomyces cerevisiae, a biochemically traceable model organism that allows for …

Uncovering The Role Of Ovol1 In Placental Stem Cell Differentiation Using Saccharomyces Cerevisiae, Maram Albakri, Patrick Lajoie, Stephen Renaud, Gargi Jaju, Hazel Dhaliwal

Western Research Forum

OVOL1 is a conserved transcription factor involved in regulating cytrophoblast differentiation in the placenta. Our objective for this study is to use Saccharomyces cerevisiae to uncover the role of OVOL1 in placental stem cell differentiation and proliferation. Previous research suggests that OVOL1 regulates cytotrophoblast progenitor state by regulating genome acetylation. Therefore, our study aims to determine how OVOL1 effect yeast growth and the yeast acetylome, and to use the yeast model to determine downstream targets of OVOL1. In order to understand the role of OVOL1, we will develop a yeast model and employ growth assays to assess growth defects and …

Knocking Out A Negative Regulator Of Hedgehog Signaling Blocks Differentiation Of Cells Into Neurons, Danielle Margaret Spice, Gregory M. Kelly Ph.D.

Western Research Forum

Hedgehog (Hh) signaling, one of many different protein signaling pathways found in mammals, is vital in many stage of neural development. A major negative regulator of Hh signaling is a protein known as Suppressor of Fused (SUFU), which acts to sequester the full length Gli transcription factors, proteins that can turn genes on and off, in the cytoplasm or facilitates its conversion to a repressive form. The P19 embryonal carcinoma cell line is a model of hind-brain neuronal differentiation and the involvement of Hh signaling, in particular the role of SUFU in this process has yet to be explored. We …

The Yeast Protein Mam33 Functions In The Assembly Of The Mitochondrial Ribosome, Gabrielle A Hillman, Michael F Henry

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Mitochondrial ribosomes are functionally specialized for the synthesis of several essential inner membrane proteins of the respiratory chain. Although remarkable progress has been made toward understanding the structure of mitoribosomes, the pathways and factors that facilitate their biogenesis remain largely unknown. The long unstructured domains of unassembled ribosomal proteins are highly prone to misfolding and often require dedicated chaperones to prevent aggregation. To date, chaperones that ensure safe delivery to the assembling ribosome have not been identified in the mitochondrion. In this study, a respiratory synthetic lethality screen revealed a role for an evolutionarily conserved mitochondrial matrix protein called Mam33 …

Functional Characterization Of The Ovarian Tumor Domain Deubiquitinating Enzyme 6b, Jasmin M. D'Andrea

USF Tampa Graduate Theses and Dissertations

The posttranslational modification ubiquitination is major regulatory mechanism used throughout cell signaling pathways such as cell cycle regulation and the DNA damage response. As such, the E3 ligases and their deubiquitinating enzyme counterparts, which conjugate and deconjugate ubiquitin to and from protein substrates respectively, must be tightly regulated to prevent aberrant cellular behaviors that could lead to diseases such as cancer.

Of the five families of deubiquitinating enzymes, the Ovarian Tumor Domain (OTU) family is fairly unique and under-studied; many of its family members hold a linkage specificity to certain ubiquitin chains and a number of them have been implicated …

Divergent Transcriptional Regulation Of Suppressors Of Cytokine Signaling Genes In Adipocytes, Paula Mota De Sa

LSU Doctoral Dissertations

The Janus Kinase - Signal Transducer and Activator of Transcription (JAK-STAT) signaling pathway transduces several signals crucial for development and homeostasis. Suppressors of cytokine signaling (SOCS) proteins control JAK-STAT signaling via a negative feedback loop. The transcription factor STAT5 is known to play a significant role in fat cell development and function, and several studies suggest that acetylation may affect STAT5 transcriptional activity. To test this hypothesis, we treated 3T3-L1 adipocytes with growth hormone (GH) to activate STAT5 in the presence or absence of histone deacetylase (HDAC) inhibitors. STAT5 acetylation levels were low in adipocytes and mostly unchanged by the …

Phospho Tensin Homolog In Human And Lipid Peroxides In Peripheral Blood Mononuclear Cells Following Exposure To Flavonoids, William Y. Boadi, Elbert L. Myles, Alekzander S. Garcia

Biology Faculty Research

Objectives: Studies have shown that human and peripheral blood mononuclear cells (PBMCs) are mostly used for research purposes to study several biochemical endpoints. The effects of the flavonoids, genistein, kaempferol, and quercetin on phospho tensin homolog (PTEN) levels in cancer cells (i.e., breast [BT549], lung [A549]), human embryonic kidney cells (HEK293), and the levels of lipid peroxides (LP) in PBMCs were respectively investigated.

Materials and methods: Cancer, kidney, and PBMCs from several donors were each exposed to each of the flavonoids at concentrations of 0, 5, 10, 15, 20, and 25 µM. Our hypotheses were that exposure of cancer and …

Characterization Of The Autophagic-Iron Axis In The Pathophysiology Of Endometriosis And Epithelial Ovarian Cancers, Stephanie Rockfield

USF Tampa Graduate Theses and Dissertations

For women in the United States, ovarian cancer (OVCA) represents the deadliest gynecological cancer with over 14,000 deaths predicted to occur in 2019 [13]. Although innovative treatment strategies have improved the 5-year outcome for these patients, the overall survival has not changed in over 40 years [14]. This is largely due to the challenges in detecting this heterogenous disease at an early stage, as there are multiple potential precursors that may give rise to different histological subtypes [14]. This dissertation is thus focused on investigating pro-survival pathways involved in the pathogenesis of endometriosis (a proposed precursor) and epithelial ovarian cancers. …

Insulin Signal Transduction Mediates Ethanol-Induced Feeding Dysfunction In A Fly Model Of Fetal Alcohol Spectrum Disorder, Manae Matsubara

McNair Research Journal SJSU

Fetal alcohol spectrum disorder (FASD) is the leading cause of congenital intellectual disabilities in the Western World, with a worldwide prevalence of 2-11% of all births. FASD is preventable but recent epidemiological studies suggest that public awareness campaigns have reached the limits of their effectiveness. Therefore, research is shifting from prevention to treatment and mitigation of symptoms. No biological treatments for FASD exist, due in part to the fact the cellular mechanisms of alcohol toxicity are not well-understood. Developmental alcohol exposure (DAE) causes a variety of deleterious effects in both vertebrates and invertebrates, including increased mortality, slow growth, learning and …

The Effect Of Intracellular Zinc Levels In Escherichia Coli On Metallo-Β-Lactamase Activity, Jill Thompson

Graduate School of Biomedical Sciences Theses and Dissertations

Antibiotic resistance is a consequence of evolution via natural selection and poses a serious threat to the world's population. Escherichia coli, and other bacterial species, have acquired genes encoding Metallo-β-Lactamases (MBLs). MBLs are zinc-dependent enzymes that degrade most β-lactam antibiotics, and have emerged as important antibacterial resistance determinants in multidrug resistant pathogens. There are several different families of MBLs, and the major clinically relevant ones are Verona Integrated-encoded Metallo-β-Lactamases (VIMs), Imipenemases (IMPs), and New Delhi Metallo-β-Lactamases (NDMs). These enzymes confer high level resistance to penicillins, cephalosporins, and carbapenems, and are not inhibited by FDA-approved β-lactamase inhibitors. Variants of NDM have …

Zinc Chloride Enhanced Chondrogenesis Is Vegf Dependent, Gilbert M. Sharp Iv

Seton Hall University Dissertations and Theses (ETDs)

Researchers have begun investigating whether insulin mimetics such as ZnCl2 could promote bone healing in both non-diabetic and diabetic fracture healing similarly to insulin. Our research focused on understanding the mechanism by which ZnCl2 affects chondrogenesis, an important component of bone fracture healing. The increases in proteoglycan deposition and cell proliferation seen in our data may be a result of ZnCl2 induction of the IGF-1 pathway. When the VEGF pathway was inhibited in ZnCl2- or insulin-treated cells significant decreases in proteoglycan deposition occurred on day 7 and 14 (P=0.007 for ZnCl2, P=0.028 for insulin) when compared to controls. This data …

Hippo Signaling In Cancer: Lessons From Drosophila Models, Kirti Snigdha, Karishma Sanjay Gangwani, Gauri Vijay Lapalikar, Amit Singh, Madhuri Kango-Singh

Biology Faculty Publications

Hippo pathway was initially identified through genetic screens for genes regulating organ size in fruitflies. Recent studies have highlighted the role of Hippo signaling as a key regulator of homeostasis, and in tumorigenesis. Hippo pathway is comprised of genes that act as tumor suppressor genes like hippo (hpo) and warts (wts), and oncogenes like yorkie (yki). YAP and TAZ are two related mammalian homologs of Drosophila Yki that act as effectors of the Hippo pathway. Hippo signaling deficiency can cause YAP- or TAZ-dependent oncogene addiction for cancer cells. YAP and TAZ are often activated …

Characterization Of Pth Type-2 Receptor ( Pth2rb ) And Its Endogenous Ligand Pth2 In Zebrafish Development, Nicholas Seitz

Theses and Dissertations

Members of the parathyroid hormone family of ligands, PTH (parathyroid hormone), PTH2, and PTHLH (parathyroid hormone-like hormone). These hormones interact with the class B GCPRs parathyroid hormone receptors PTH1R, PTH2R, and PTH3R to regulate a variety of biological processes. In mammals, PTH and PTHLH activate PTH1R and PTH3R to mediate serum calcium homeostasis, chondrogenesis, and bone maintenance. PTH2R activation by PTH2 has been studied primarily in regard to its neuroendocrine roles but is also found in the skin where it contributes to wound healing and keratinocyte differentiation. Still, little is known about the impacts of PTH2R signaling relative to PTH1R …

Microrna Profiling And Engineering Of Cho Cell Lines Stably Expressing Difficult-To-Express Lysosomal Protein, Ifeanyi Amadi

KGI Theses and Dissertations

Difficult-to-express (DTE) recombinant proteins like multi-specific proteins, DTE monoclonal antibodies and lysosomal enzymes, have seen difficulties in manufacturability using Chinese hamster ovary (CHO) cells and other mammalian cells as production platforms. CHO cells are preferably used for protein production because of their innate ability to secrete human-like recombinant proteins with post-translational modification, resistance to viral infection and familiarity with drug regulators. However, despite huge progress made in engineering CHO cells for high volumetric productivity, expression of DTE proteins like recombinant lysosomal sulfatase represent one of the poorly understood proteins. Furthermore, there are growing interest in the use of microRNAs (miRNAs) …

Novel Low Shear 3d Bioreactor For The Scaled Production Of High Purity Human Mesenchymal Stem Cells, Andrew Burns

KGI Theses and Dissertations

Human mesenchymal stem cells are an ideal candidate for stem cell therapies. They have been researched since the 1960’s and can differentiate into many desired functional cell types without undergoing teratogenesis. However, higher yields are needed for a marketable, successful stem cell therapy. To accomplish this, cells will have to be cultured to expand them to therapeutically relevant dosages for multiple patients. Bioreactor production is an ideal method to solve this problem.

The aim of this thesis is to test and validate a novel bioreactor for the cultivation of human mesenchymal stem cells. In this work, we investigate a novel …

Reversal Of P-Glycoprotein And Breast Cancer Resistance Protein Mediated Multidrug Resistance In Vitro Using In Silico Identified Novel Compounds, Amila Nanayakkara

Biological Sciences Theses and Dissertations

Multidrug resistance (MDR) is a major cause of chemotherapy failure. Overexpression of ATP-binding cassette (ABC) transporters, P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) are two well-studied drug transporters which are associated with MDR. These two transporters also act as a major functional unit of the blood brain barrier to protect the brain from xenobiotics and toxins. Lack of clinically approved P-gp and BCRP inhibitors renders chemotherapy treatments of many MDR cancers ineffective and obstructs drug uptake into the brain.

Using computational methods, we have identified new compounds that inhibit P-gp (Brewer et al., Mol. Pharmacol. 2014). Several of …

Reversal Of P-Glycoprotein And Breast Cancer Resistance Protein Mediated Multidrug Resistance In Vitro Using In Silico Identified Novel Compounds, Amila Nanayakkara

Biological Sciences Theses and Dissertations

Multidrug resistance (MDR) is a major cause of chemotherapy failure. Overexpression of ATP-binding cassette (ABC) transporters, P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) are two well-studied drug transporters which are associated with MDR. These two transporters also act as a major functional unit of the blood brain barrier to protect the brain from xenobiotics and toxins. Lack of clinically approved P-gp and BCRP inhibitors renders chemotherapy treatments of many MDR cancers ineffective and obstructs drug uptake into the brain.

Using computational methods, we have identified new compounds that inhibit P-gp (Brewer et al., Mol. Pharmacol. 2014). Several of …

Towards A Better Understanding Of Temporomandibular Disorder, Jessica R. Cox

Graduate Theses/Dissertations

Results from the OPPERA study provided evidence that risk factors such as neck muscle tension, prolonged jaw opening, and female gender increase the likelihood of developing temporomandibular joint disorders (TMJD), which are prevalent, debilitating orofacial pain conditions. Peripheral and central sensitization, which mediate a lowering of the stimulus required for pain signaling, are implicated in the underlying pathology of chronic TMJD. The goal of my study was to investigate cellular changes in the expression of proteins associated with the development of central sensitization. Female Sprague-Dawley rats were injected with complete Freund’s adjuvant in the upper trapezius muscles to promote trigeminal …

Kinetics Of Hiv-1 Uncoating In C20 Microglial Cells, Melanie Anne Taylor

Graduate Theses/Dissertations

Uncoating is a poorly understood yet required step of HIV-1 replication that is defined as the disassembly of the viral capsid structure. The goal of this project is to characterize uncoating in C20 microglial cells. These cells are a natural target of HIV-1 that are infected to establish latent viral reservoirs and HIV-associated neurological disorders. A stable C20 cell line that expresses TRIM-CypA was established to study the kinetics of uncoating with the CsA washout assay. The expression of TRIM-CypA was confirmed by western blot and the functionality of the protein was confirmed by a viral infectivity assay. Using this …

Further Characterization Of The Skeletal Phenotype In A Hurler Syndrome Mouse Model And The Ethical Treatment Of Children In Medicine, Anna Marie Mcwoods

Graduate Theses/Dissertations

Mucopolysaccharidosis type I (MPS I) is a rare, autosomal recessive disorder caused by the deficiency of the lysosomal enzyme α-L-iduronidase (IDUA). Absence of IDUA results in the accumulation of dermatan and heparin sulfate and ultimately causes multi-system dysfunction. The most severe form of MPS I is Hurlers syndrome, a rapidly progressive disorder that, if left untreated, is fatal. Current treatment options for diagnosed individuals includes hematopoietic stem cell transplantation (HSCT) and enzyme replacement therapy (ERT). These treatments are able to ameliorate the majority of symptoms with the exception of the bone phenotype. This investigation aimed to further characterize the bone …