Cell and Developmental Biology Commons^™

Quantification Of Nuclear Dynamics During Epithelial Remodeling, Noah De Leeuw

Electronic Theses and Dissertations

The morphogenesis of developing tissues is contingent on an extensive array of rearrangements in cellular shape, position and identity at large and small scales. One commonly used process to reshape tissues is the cell intercalation-driven elongation of a tissue in a common axis, in which rows of epithelial cells undergo oriented intercalation in a directional fashion. In most models of intercalation, cells are treated as homogeneous objects directed in their shape changes by cortical forces localized along cell-cell interfaces or tricellular junctions. However, less attention has been paid to how inhomogeneities in mechanical resistance of their own internal structures affects …

Dna Damage Response Activates The Electron Transport Chain And Oxidative Metabolism By Two Parallel Mechanisms, Shreya Nagar

Theses and Dissertations

The DNA damage response (DDR) is an evolutionarily conserved process essential for cell survival. Major part of DDR is coordinated by DNA damage checkpoint (DDC). In addition to DDC, eukaryotic cells also have DNA replication checkpoint (DRC) that is distinct from the DDC and specifically signals slowly progressing or arrested replication forks. DDR involves stalling or arrest of the cell cycle, initiation of DNA repair, and altered regulation of transcription, translation, and the ubiquitin-proteasome system. DDR also triggers transcription shut-off of histone genes. One of the key outcomes of DDC/DRC activation is the increased synthesis of the deoxyribonucleoside triphosphates (dNTPs), …

Molecular Regulation Of The Salicylic Acid Hormone Pathway In Plants Under Changing Environmental Conditions, Christina A. M. Rossi, Eric J. R. Marchetta, Jong Hum Kim, Christian Castroverde

Biology Faculty Publications

Salicylic acid (SA) is a central plant hormone mediating immunity, growth, and development. Recently, studies have highlighted the sensitivity of the SA pathway to changing climatic factors and the plant microbiome. Here we summarize organizing principles and themes in the regulation of SA biosynthesis, signaling, and metabolism by changing abiotic/biotic environments, focusing on molecular nodes governing SA pathway vulnerability or resilience. We especially highlight advances in the thermosensitive mechanisms underpinning SA-mediated immunity, including differential regulation of key transcription factors (e.g., CAMTAs, CBP60g, SARD1, bHLH059), selective protein–protein interactions of the SA receptor NPR1, and dynamic phase separation of the recently identified …

Developing Red Fluorescent Zn2+ Sensors And Characterizing Zn2+ Homeostasis In Mucolipidosis Type Iv Disease, Anna M. Dischler

Electronic Theses and Dissertations

Zinc (Zn²⁺) is a divalent, redox-inert metal that plays a vital role in many cellular processes either by acting as a catalytic cofactor or a labile signaling molecule in the cytoplasm. Cytosolic Zn²⁺ levels are tightly regulated to stay within a narrow window of concentrations, but fluctuations in Zn²⁺ signals have been detected in a variety of cells. We developed a genetically encoded, single red fluorescent protein (RFP) based Zn²⁺ sensor, RZnP1, that can be used alongside green-wavelength sensors for the simultaneous detection of different signaling molecules within the same cells or among different subcellular …

Identifying The Role Of Phospholipase D1 And Phosphatidic Acid In Exocytosis, Broderick L. Bills

Electronic Theses and Dissertations

Exocytosis is an essential process for intercellular communication in eukaryotic cells. This process involves significant changes in membrane curvature, and lipids and curvature-sensing proteins can assist these processes. One protein in particular, phospholipase D1 (PLD1), and its product, the lipid phosphatidic acid (PA), are involved in multiple exocytic processes. However, PLD1 and PA’s role in this process has remained unclear. In this work, PLD1 and the production of PA were visualized during exocytosis, and PA localization to regions of membrane curvature was established. Together, these results support the hypothesis that PLD1 production of PA stabilizes negative curvature during membrane fusion. …

The Role Of Schwann Cells In Nerve Injury: Forskolin-Mediated Camp Activation Upregulates Tnfα Expression Despite Nf-Κb Downregulation In Lps-Treated Schwann Cells, Caitlyn E. Henry, Angela L. Asirvatham Ph.D.

Student Research Poster Presentations 2023

Although Schwann cells are known to play a role in axonal regeneration following nerve injury and inflammation, the exact mechanism is unknown. This study explores two potential mechanisms: the NF-κB and cAMP pathways. The NF-κB pathway produces cytokines, such as TNFα, to regulate inflammation, whereas the cAMP pathway is anti-inflammatory and regulates Schwann cell proliferation via AKAP95 and cyclin D3. Although it is well-known that NF-κB and cAMP are involved in inflammation, not much is known regarding the effects of forskolin-mediated cAMP activation on LPS-mediated NF-κB activation in Schwann cells. In this study, RT4-D6P2T immortalized rat Schwann cells were treated …

Molecular And Systemic Epigenetic Inheritance: Integrating Development, Genetics, And Evolution, Robert Lickliter, David S. Moore

Pitzer Faculty Publications and Research

Currently, a central problem for theoretical biology is the integration of development with genetics and evolutionary theory. Through the late 20^th century, biologists held that animals resemble their ancestors strictly because of the transgenerational transmission of DNA. This view effectively wrote development out of evolutionary biology. However, many molecular and developmental biologists now understand that phenotypes—anatomical, physiological, and behavioral traits—are not determined by genes (i.e., DNA segments) alone; instead, they emerge epigenetically from developmental processes involving co-acting genetic factors, environmental factors, molecular epigenetic factors, and other non-genetic factors within organisms’ bodies. This insight forces a rethinking of biological inheritance. …

Analysis Of A Cathepsin Protease In Normal Development And Tumor Metastasis In Drosophila Melanogaster, Lindsey Fannin

Mahurin Honors College Capstone Experience/Thesis Projects

Cysteine cathepsins are an important class of fifteen proteases with involvement in normal development and tumor progression. To better understand their contribution to these processes, the cathepsin L protease in Drosophila melanogaster was studied. In part one of this project, the role of this cathepsin in the normal development of Drosophila wings was analyzed. The GAL4/UAS-system and RNAi were used to downregulate this cathepsin in various regions of the wing and progeny were inspected for phenotypic irregularities. An abnormal phenotype of curved wings was found and hypothesized to be a result of apoptosis. Further experimentation will be required to prove …

Investigating The Effects Of Paraquat On Kidney Disease Biomarkers In Hek293 Cells, Zounaira Shahzad

Honors Undergraduate Theses

Farmworkers in Apopka, FL, have been subjected to overhead pesticide exposure since the 1940s. Pesticides including Paraquat (PQ), Metribuzin and Aldicarb were sprayed onto the field while farmworkers worked. In "Fed Up: The High Cost of Cheap Food," farmworkers recalled the physical toll these conditions took on their bodies, blaming pesticides for their diseases, such as chronic kidney disease (CKD). While established that pesticides, specifically PQ, may be involved in some forms of Parkinson's disease, no explicit connection has been identified for SLE, CKD, and other diseases experienced by farm workers. This study evaluated whether pesticides could contribute to kidney …

Gestational Vulnerability To Ozone Air Pollution - A Placental Story, Vishnupriya Alavala, Sarah Brent, Russell Hunter, Matthew J. Campen, Andrew Ottens

UROP Posters

About 99% of the global population resides in areas with air pollution surpassing World Health Organization standards. Air pollution is associated with adverse neonatal health outcomes such as low fetal birth weight and an increased risk for maternal pre-eclampsia. A particularly reactive air pollutant is ozone, which forms reactive oxygen species that induce cellular damage. Research exists on the dispersion of reactive oxygen species through the bloodstream leading to fetal vulnerability during pregnancy, specifically via the placenta. Yet, placental and fetal development is a temporal process with varied susceptibility to negative gestational outcomes.

To addressing this gap, our laboratory utilized …

Proposing An Rna Interference (Rnai)-Based Treatment For Human Immunodeficiency Virus (Hiv) By Analyzing The Post-Transcriptional Gene Targeting Of Sars-Cov-2, Hepatitis C Virus, And A549 Lung Cancer Cells, Arjun Jagdeesh

UROP Posters

Human Immunodeficiency Virus (HIV) is a retrovirus that infects CD4+ T cell lymphocytes in humans, leading to the development of Acquired Immunodeficiency Syndrome (AIDS) if left untreated. While current treatment methods, including antiretroviral combination treatments, effectively limit HIV replication, HIV can evade these treatments due to its high mutation rate. Long-term antiretroviral treatment can also be toxic to patients, meaning patients would benefit from a new mechanism of HIV treatment. RNA interference (RNAi) is an antiviral pathway found in mammals, plants, and insects that involves a small-interfering RNA that is incorporated into a protein complex called the RNA-induced Silencing Complex …

Ros And Sfk Signaling Is Required For Development Of Hematopoietic Stem Cells In Zebrafish, Bradley Williams, Erich Damm

UROP Posters

ROS and SFK signaling is required for development of hematopoietic stem cells in zebrafish

Bradley Williams and Erich Damm

Background

Hematopoiesis is the process in which the myriad of mature blood cell types, including erythrocytes and leukocytes, develop from hematopoietic stem cells (HSCs) throughout the life of an organism. In vertebrates, HSCs originate from endothelial cells lining the floor of the dorsal aorta. This process is referred to as the endothelial to hematopoietic transition and is likely controlled in part by molecular signals from neighboring cells. Investigation into the molecular signaling mechanisms controlling the development of HSCs is critical to …

Host Cell Responses Modulate Oncolytic Viral Treatment Of Neuroblastoma Cells, Kritika Kedarinath

Electronic Theses and Dissertations, 2020-2023

Neuroblastoma is an aggressive pediatric cancer that is poorly responsive to traditional cancer therapies. Oncolytic viral (OV) vectors such as Zika virus (ZIKV) and Parainfluenza virus type 5 (P/V virus) are promising neuroblastoma therapeutics, but the role of innate immune responses in the effectiveness of OV killing is not well understood. Previous studies showed the neuroblastoma cell line SK-N-AS (expressing low CD24) had low permissivity for ZIKV infection, and this restriction was relieved by ectopic CD24 expression (CD24-high cells). Compared to permissive CD24-high cells, the non-permissive CD24-low cells had elevated basal levels of IRF-1, NF?B and phosphorylated STAT1; these cells …

Conserved Novel Interactions Between Post-Replicative Repair And Mismatch Repair Proteins Have Differential Effects On Dna Repair Pathways, Anna K. Miller

Theses and Dissertations--Toxicology and Cancer Biology

DNA mismatch repair (MMR) is the DNA repair mechanism that repairs base-base mispairs and small insertions and deletions remaining after replication. MMR is also required for apoptosis after certain types of exogenous DNA damage that result in damage-associated mispairs. The basic MMR mechanism is well understood; however, proteins associated with MMR continue to be identified. The roles of these interacting proteins in MMR are largely unknown. We have identified the yeast protein Rad5 as a novel interactor of the critical MMR proteins Msh2 and Mlh1. Rad5 is a DNA helicase and E3 ubiquitin ligase involved in post-replicative repair. However, to …

Elucidating The Functional Importance Of Peroxiredoxin Iv In Prostate Cancer And Its Secretion Mechanism, Na Ding

Theses and Dissertations--Toxicology and Cancer Biology

Prostate cancer is the most common and second leading cause of cancer death in men. Prevailing theories state that inflammation may drive prostate carcinogenesis via oxidative stress and the generation of reactive oxygen species (ROS) that induce somatic mutagenesis. Since high proliferating cells or cancer cells exhibit aberrant metabolism to satisfy the needs of energy for rapid cell proliferation, they also generate high levels of ROS which stimulates the expression of cellular antioxidants to overcome the dysregulation of redox homeostasis through the regulation of redox-sensitive transcription factors. Among different antioxidants, peroxiredoxin (Prx) family proteins are the highly conserved and mostly …

Beyond Mitosis, Plk1-Mediated Phosphorylation Re-Wires Cancer Metabolism And Promotes Cancer Progression, Qiongsi Zhang

Theses and Dissertations--Toxicology and Cancer Biology

Polo-like kinase 1 (PLK1) is a well- characterized regulator of cell division and is known to be highly expressed in certain types of tumors. It has been demonstrated the multifaceted roles of PLK1 in regulation of transcription, translation, epigenetics, DNA damage and cellular metabolism et al. Despite these findings, the precise mechanisms by which PLK1 regulates these processes beyond mitosis remain unclear. PLK1-mediated phosphorylation and misregulation of its substrates has been linked to tumorigenesis, cancer progression, drug resistance and worse prognosis. In this study, we investigated the non-canonical functions of PLK1 in cancer metabolism and drug resistance. We found that …

Dcaf14 Regulates Cdt2 To Promote Set8-Dependent Replication Fork Protection, Neysha Tirado-Class, Caitlin Hathaway, Anthony Nelligan, Huzefa Dungrawala

Molecular Biosciences Faculty Publications

DDB1- and CUL4-associated factors (DCAFs) CDT2 and DCAF14 are substrate receptors for Cullin4–RING E3 ubiquitin ligase (CRL4) complexes. CDT2 is responsible for PCNA-coupled proteolysis of substrates CDT1, p21, and SET8 during S-phase of cell cycle. DCAF14 functions at stalled replication forks to promote genome stability, but the mechanism is unknown. We find that DCAF14 mediates replication fork protection by regulating CRL4CDT2 activity. Absence of DCAF14 causes increased proteasomal degradation of CDT2 substrates. When forks are challenged with replication stress, increased CDT2 function causes stalled fork collapse and impairs fork recovery in DCAF14-deficient conditions. We further show that stalled fork protection …

Otud5 Limits Replication Fork Instability By Organizing Chromatin Remodelers, Angelo De Vivo, Hongseon Song, Yujin Lee, Neysha Tirado-Class, Anthony Sanchez, Sandy D. Westerheide, Huzefa Dungrawala, Younghoon Kee

Molecular Biosciences Faculty Publications

Proper regulation of replication fork progression is important for genomic maintenance. Subverting the transcription-induced conflicts is crucial in preserving the integrity of replication forks. Various chromatin remodelers, such as histone chaperone and histone deacetylases are known to modulate replication stress, but how these factors are organized or collaborate are not well understood. Here we found a new role of the OTUD5 deubiquitinase in limiting replication stress. We found that OTUD5 is recruited to replication forks, and its depletion causes replication fork stress. Through its C-terminal disordered tail, OTUD5 assembles a complex containing FACT, HDAC1 and HDAC2 at replication forks. A …

The Identification Of Two M20b Family Peptidases Required For Full Virulence In Staphylococcus Aureus, Nathanial James Torres, Devon Rizzo, Maria A. Reinberg, Mary-Elizabeth Jobson, Brendan C. Totzke, Jessica K. Jackson, Wenqi Yu, Lindsey Neil Shaw

Molecular Biosciences Faculty Publications

We have previously demonstrated that deletion of an intracellular leucine aminopeptidase results in attenuated virulence of S. aureus. Herein we explore the role of 10 other aminopeptidases in S. aureus pathogenesis. Using a human blood survival assay we identified mutations in two enzymes from the M20B family (PepT1 and PepT2) as having markedly decreased survival compared to the parent. We further reveal that pepT1, pepT2 and pepT1/2 mutant strains are impaired in their ability to resist phagocytosis by, and engender survival within, human macrophages. Using a co-infection model of murine sepsis, we demonstrate impairment of dissemination and survival …

S-Acylation Is A Key Regulator Of Orai1/Stim1-Mediated Store-Operated Calcium Entry In T Cells, Savannah J. West Diaz

Dissertations and Theses (Open Access)

Orai1 and STIM1 proteins are the essential components of the Ca²⁺ release activated Ca²⁺ (CRAC) channel which is required for store-operated Ca²⁺ entry (SOCE) in T cells and subsequent signaling events leading to T cell activation, proliferation, and differentiation. Plasma membrane (PM)-localized Orai1 is the pore-forming subunit of the CRAC channel, and STIM1 is the Ca²⁺ sensor localized to the endoplasmic reticulum (ER) membrane in quiescent T cells. T cell receptor (TCR) stimulation leads to depletion of ER Ca²⁺ stores resulting in Ca²⁺ no longer being bound to STIM1. This activates STIM1 by triggering …