Cell and Developmental Biology Commons^™

The Rpm-1/Phr Signaling Hub Modulates Tau-Induced Neurodegeneration Through Regulation Of Microtubule Stability And Mapk Pathways In C. Elegans, Xinxing Ding

Theses and Dissertations

Neurodegenerative diseases, including Alzheimer's disease and frontotemporal dementia, are characterized by the accumulation of pathological tau proteins and progressive neuronal loss. Although research regarding tau-mediated toxicity is extensive, the specific pathology that determine whether neurons maintain homeostasis or succumb to collapse under tau-induced stress remain incompletely elucidated. A central, yet still insufficiently understood, feature of these diseases is the disruption of the microtubule (MT) cytoskeleton . The PHR protein family is evolutionarily highly conserved; within this family, RPM-1 in C. elegans functions as an intracellular signaling hub that regulates axon development, synapse formation, axon termination, and various microtubule-associated processes. This …

Genetic Screen For Regulators Of Pol4, A Dna Repair Polymerase In Saccharomyces Cerevisiae, Pasang Dolma Sherpa

Theses and Dissertations

In Saccharomyces cerevisiae, DNA polymerase 4 (POL4) is the beta repair polymerase, the product of the POL4 gene, and is involved in base excision repair (BER) and microhomology-mediated end joining (MMEJ). Despite its involvement in these repair pathways and its conservation across eukaryotes, deletion of POL4 shows no detectable phenotype under standard laboratory conditions. I hypothesized that unknown genes act as backup systems, providing redundant activities that allow pol4Δ cells to survive. To test this, a genetic screen for mutants showing synthetic lethality with pol4Δ was implemented. I constructed a strain lacking the POL4 gene and carrying …

3d Bioprinting On Electrospun Nanofibrous Scaffolds To Fabricate Myocardial Patches, Muthu Parkkavi S

Theses and Dissertations

Tissue-engineered three-dimensional (3D) myocardial patches offer superior and innovative treatment strategy for myocardial infarction (MI). Among the various scaffold fabrication techniques, electrospinning and 3D bioprinting have received great attention due to their ability to recreate native cardiac tissue mimetic characteristics. Despite several advantages, electrospun nanofibers have limitations in cell delivery due to random cell seeding, while bioprinting faces challenges in creating hydrogel constructs with ideal mechanical properties capable of supporting cardiac contraction/relaxation cycle. Hence in this work, hybrid myocardial patches were developed by converging electrospinning and bioprinting techniques.

Electrospinning of PLCL:PEOz (B73, 7:3 blend of poly-L-lactide-co-ε-caprolactone (PLCL) and polyethyl oxazoline …

Unpaired Virtual Histological Staining Of Tissue From Autofluorescence Using Regularized Cycle-Consistent Adversarial Networks, Zhesi Wen

Theses and Dissertations

We present a regularized CycleGAN with a Dense Residual U-Net to virtually stain autofluorescence images of tissue into H&E-like images. Our method outperforms standard architectures, reduces artifacts, and achieves superior FID scores, enabling efficient, label-free, and accurate digital pathology for unpaired datasets using multi-channel fluorescence inputs.

Developing A Small Molecule To Inhibit Hsf1 Expression In Cancer And Evaluating Natural Genetic Variation In Small Molecule Toxicity., Michaela Kendal Foley

Theses and Dissertations

Each year cancer affects nearly 20 million people worldwide and genetic differences across populations can impact cancer onset and progression. Specifically, tumors with high levels of HSF1, the master regulator of the cytoprotective heat shock response (HSR), are correlated with poor patient outcomes in multiple cancers such as prostate, breast, and melanoma. Subsequently, the development of pharmacological inhibitors of HSF1 represents a promising strategy for anticancer therapeutics. Using a luciferase-based transcriptional reporter, two small molecule libraries were screened for inhibitors of HSF1 expression in human embryonic kidney cells, yielding ten compounds that decrease HSF1 expression. To identify if cancer lines …

The Role Of Non-Coding Rnas As An Innovative Therapeutic Tool For Hepatocellular Carcinoma, Nabila Mohamed Hosni El Kramani

Theses and Dissertations

Hepatocellular carcinoma (HCC) is the second lethal cancer worldwide, with over 60 million new patients added annually. Hepatitis B infection and toxins, e.g., aflatoxin, contribute to the incidence of HCC. Egypt and China show the highest prevalence of viral hepatitis and HCC in the world.

Long non-coding RNAs (lncRNAs) are non-protein-coding transcripts larger than 200 nucleotides. These transcripts work at the transcriptional, post-transcriptional, and epigenetic levels to regulate gene expression by interacting with various biomolecules, such as RNA, DNA, and proteins. They serve essential functions in chromatin remodeling and cell survival, differentiation, and proliferation. The role and biological interactions of …

Expression And Function Of Floral Symmetry Genes In The Regulation Of Flower Shape In Fedia Graciliflora, Theresa A. Mustacchio

Theses and Dissertations

Shifts between radial symmetry (actinomorphy) and bilateral symmetry (zygomorphy) in flowers have occurred multiple times independently within angiosperms (flowering plants). Evidence across angiosperms indicate the transcription factors RADIALIS (RAD), DIVARICATA (DIV), and CYCLOIDEA (CYC) play a major role in regulating floral symmetry and morphology. The CYC-like genes have been shown to shift their expression dorsally independently in nearly all shifts to bilaterally symmetrical flowers examined. Three core eudicot clades of CYC-like genes have been identified: CYC1, CYC2 and CYC3, with only CYC2 genes being shown to have a role in floral symmetry. We use the non-model plant, Fedia graciliflora (Caprifoliaceae) …

Mctr3 Mitigates Cigarette Smoke-Induced Pulmonary Inflammation And Damage, Yu Par Aung Myo

Theses and Dissertations

Smoking is deleterious to our lungs and can precipitate in a multitude of diseases, including chronic obstructive pulmonary disease (COPD). COPD is primarily caused by smoking cigarettes and is a major public health issue. Current therapies only treat symptoms without halting or reversing disease progression, thus highlighting a large unmet need to develop new therapies. We address this gap by investigating maresin conjugate in tissue regeneration 3 (MCTR3) which is a newly discovered specialized pro-resoling mediator (SPM) that has the novel property of promoting tissue repair and regeneration in addition to being anti-inflammatory and pro-resolving. For the first time, we …

Functional Analysis Of Ligand Binding Domain 2 Of Outer Surface Protein C Of Borreliella Burgdorferi, Gavin Z. Chambers

Theses and Dissertations

Lyme disease, caused by the spirochete Borreliella burgdorferi, is the most common vector-borne infection in North America. A critical determinant of early mammalian infection is outer surface protein C (OspC), a highly variable lipoprotein that is indispensable for spirochete survival but whose precise function remains unresolved. OspC has been proposed to mediate diverse roles, including complement evasion, adhesion, tissue dissemination, and antiphagocytic activity, supporting the view that it is a multifunctional virulence factor. Structural studies have identified two putative ligand-binding domains (LBD1 and LBD2), with LBD2 forming a solvent-exposed crown at the membrane-distal end of the OspC dimer.

To …

Exploring The Role Of Transcription Factor Nrf1 In Autophagy And Inhibiting The Nrf1 Bounce-Back Response, Madison A. Ward

Theses and Dissertations

Cells exposed to proteotoxic stress invoke adaptive responses aimed at restoring proteostasis. Our previous studies have established a firm role for the transcription factor Nuclear factor-erythroid derived-2-related factor-1 (Nrf1) in responding to proteotoxic stress elicited by inhibition of cellular proteasome. Following proteasome inhibition, Nrf1 mediates the synthesis of new proteasomes, thus enabling cells to mitigate proteotoxic stress. Here, we report that under similar circumstances, multiple components of the autophagy-lysosomal pathway (ALP) were transcriptionally upregulated in an Nrf1-dependent fashion, thus providing the cells with an additional route to cope with proteasome insufficiency. In response to proteasome inhibitors, Nrf1-deficient cells exhibited profound …

Caspases Protect Against Hyperglycemia Induced Necroptosis-Like Cell Death In Brain Endothelial Cells, Aleena S. Mathew

Theses and Dissertations

Acute diabetes characterized by high spikes in blood glucose levels in association with severe hyperglycemia can lead to an increased risk of ischemic stroke in the brain. To better understand high blood glucose levels, hyperglycemia, in the brain we explored its effects on endothelial cells. Endothelial cells line the inner walls of blood vessels and are directly impacted in hyperglycemia. Brain endothelial cells are a major component of the blood brain barrier (BBB) which tightly regulates the brain’s microenvironment. The type of cell death such as apoptosis, caspase dependent, or necroptosis, caspase independent, can exacerbate diabetes associated complications. There is …

Unleashing Serine Palmitoyltransferase In Test Tubes And Mice, Matthew W. Peart

Theses and Dissertations

Canonically known both for structural contributions to lipid bilayers and roles in cell signaling, the sphingolipids comprise a dynamic, multifaceted class of molecules which are studied to understand homeostatic cell biology as well as pathophysiology. Sphingolipids contribute to tissue-specific structures such as myelin, a multilayer membrane that allows for rapid conduction of action potentials along neuronal axons. All sphingolipids are downstream products of the rate-limiting and initiating enzyme in the de novo sphingolipid synthesis pathway, Serine palmitoyltransferase (SPT). Demonstrative of its status as the enzyme that catalyzes a crucial step in a biochemical pathway, SPT activity is strictly regulated. This …

Targeting The Achilles’ Heel Of Lung Cancer Induced By Oncogenic P53, Brandon G. Velasco

Theses and Dissertations

Mutations of the tumor suppressor gene, TP53, are the most prevalent oncogenic mutations in lung cancer, occurring in up to 70% of human non-small cell lung cancer (NSCLC). The majority of mutations in p53 are missense mutations that cause not only a loss of tumor suppressor function, but also gain of oncogenic functions, like tumorigenicity, immune suppression, and chemoresistance. Previous studies have shown that the depletion of gain-of-function (GOF) p53 or disruption of its ability to transactivate the expression of genes related to oncogenesis eliminates its tumorigenic properties indicating a dependency of human lung cancer cells expressing GOF p53 …

Ecological And Pathological Applications Of The Heat Shock Response, Taylor Rae Stanley

Theses and Dissertations

The heat shock response (HSR) is a cytoprotective stress response pathway that regulates cellular proteostasis. The HSR is an evolutionarily conserved pathway that is essential for normal cellular functioning. Here, we explore the broad ecological and pathological impacts of the HSR. In an ecological context, we perform gene level analysis of the transcriptomes of two closely related sunfish. We found that the more invasive bluegill sunfish has gene expansions in two HSR gene families, the HSP70 family and the HSP90 family compared to the redear sunfish. These gene expansions were also observed in several other teleost fish species and were …

Investigation Of Reproductive Inhibition During Chronic Heat Stress In C. Elegans, Macy Makenna Nielander

Theses and Dissertations

Nearly all organisms experience heterogeneity in environmental conditions that can negatively impact fitness. A common adaptive strategy to reduce the impact of this stress is called facultative diapause, where development and reproduction are temporarily arrested to promote survival. Facultative diapause is characterized by three major criteria, the arrest must be (i) induced by an unfavorable environmental condition, (ii) reversible, and (iii) driven by genetically regulated mechanisms. The aim of this thesis was to determine whether chronic heat-induced inhibition of egg laying in Caenorhabditis elegans represents a novel form of facultative diapause. It was found that the inhibition of egg-laying is …

Corneal Epithelial Tissue Engineering Approaches To Treat Limbal Stem Cell Deficiency, Sasirekha K

Theses and Dissertations

A clear healthy cornea is essential for visual acuity. As a self-renewing and regenerating tissue, the corneal epithelium has a stem cell pool, the limbus that acts as its proliferative reservoir. When limbal epithelial stem cells are destroyed or become dysfunctional, a pathological state known as limbal stem cell deficiency (LSCD) manifests. Damaged corneas have been successfully reconstructed by transplanting the cultured limbal epithelial stem cells. Limbal stem cell transplantation (LSCT) is one of the applicable and most challenging procedures in clinical ophthalmology for the reconstruction of the stratified ocular surface epithelium in patients with LSCD. Given the above challenge, …

Exploring The Role Of Rb1 In Cellular Differentiation Using Patient-Derived Stem Cells, Ambily Vincent

Theses and Dissertations

The Retinoblastoma (RB1) gene, predominantly recognized as a tumour suppressor, plays a crucial role in early growth and development. Mice lacking the retinoblastoma gene do not survive and exhibit defects in the differentiation of various tissues, underscoring its involvement in cellular differentiation. This suggests that the functions of the RB1 gene extend beyond its role as a tumour suppressor, encompassing cell cycle regulation, maintenance of genomic stability, cellular senescence, and cellular differentiation.

While the tumour suppressor function of the RB1 has been extensively studied, its role in cellular differentiation remains incompletely understood. Existing literature, primarily based on animal models, has …

Assessment Of Tripeptides Self-Assembly & Er Stress On Cell Viability And Exosome Secretion In Mda-Mb231, Azmat Parveen

Theses and Dissertations

This study delves into the effects of tripeptides KYpF and WYpK(NBD) on MDA-MB-231 cells, uncovering KYpF's ability to reduce cell proliferation and exosome secretion in peptide treated cells. Conversely, WYpK(NBD) demonstrated significant toxicity at 10 μM. These insights pave the way for optimizing peptide-based cellular treatments for exosome secretion purposes.

Development Of Anti-Fibrotic Agents For Potential Use In Glaucoma Filtration Surgery To Prevent Scar Formation, Nikhala Shree S

Theses and Dissertations

Glaucoma is the second leading cause of blindness with irreversible vision loss. It is marked by the degeneration of retinal ganglion cells, which results in optic nerve head damage. Intraocular pressure (IOP) is a prime risk factor of glaucoma controlled by various treatment regimens i.e., medication, laser, and/ or surgery. It is reported that longterm exposure to anti-glaucoma medications (AGM) may subtle the surgical success rate leading to postoperative fibrosis. Transforming growth factor beta (TGF-β) is a growth factor that plays an important role in the development of glaucoma and promotes fibrosis.

This study is aimed at developing peptides to …

Interleukin 24 Induces Apoptosis Through Glycogen Synthase Kinase-3 Beta Inactivation In Prostate Cancer Cells, Sual J. Lopez, Moira Sauane

Theses and Dissertations

Interleukin 24 (IL-24) is a tumor-suppressing protein currently in clinical trials. IL-24 induces cancer-specific apoptosis by activating endoplasmic reticulum (ER) stress and mitochondria dysfunction. We have previously demonstrated that IL-24 leads to apoptosis in cancer cells by protein kinase A (PKA) activation in human breast cancer cells. To further understand the mechanism by which IL-24 induces apoptosis, I analyzed the role of glycogen synthase kinase-3 (GSK3), a highly conserved and normally active serine/threonine kinase in cancer cells and downstream target of PKA. The work reported here provides direct evidence that GSK3 was inhibited following IL-24 treatment in human prostate cancer …

Cytotoxicity, Antibacterial And Anti-Inflammatory Properties Of A Synthesized Curcumin Analog And One Of Its Novel Derivatives, Marian Amir

Theses and Dissertations

This research aims to describe the synthesis, characterization, and the biological response via investigating the cytotoxic activity, hypoxic microenvironment response, antibacterial, and anti-inflammatory properties of the novel curcumin analog H-4073 and its succinate derivative (H-4073 SuD) in the context of hepatocellular carcinoma (HCC). The study also aimed to compare the effects of H-4073 and H-4073 SuD to assess their relative efficacy and potential as therapeutic agents. First, the cytotoxic effects of H-4073 and H-4073 SuD were evaluated on HEPG2 cell lines under normal conditions. Results revealed that H-4073 exhibited a significantly better cytotoxic effect than H-4073 SuD in normoxia. However, …

Using Rapid Protein Degradation To Determine The Effect Of Runx1 Loss-Of- Function On Dna Damage Accumulation And Repair., Jackriel Pina Morales

Theses and Dissertations

Germline mutations in RUNX1 are associated with familial platelet disorder with a predisposition to myeloid malignancy (RUNX1-FPDMM), in which patients present with low platelet counts,excessive bleeding and bruising, and an increased risk of Acute Myeloid Leukemia (AML)/Myelodysplastic Syndrome (MDS) development throughout their lifetime. To understand how these loss-of-function mutations in RUNX1 drive predispose to malignancy, it is important to develop a detailed understanding of the molecular basis of RUNX1 function. While RUNX1 is a transcription factor, preliminary data from our group and work from others suggests that RUNX1 also interacts with proteins that are critical for DNA damage …

Investigating The Antibacterial And Immunomodulatory Effects Of Resolvin D2 On Monocytes And Macrophages, Cristina Maria Padovani

Theses and Dissertations

In the late phase of sepsis, immunosuppression occurs, where the host is unable to clear the pre-existing infection and is susceptible to secondary infections. It is believed that the ideal treatments for sepsis should attenuate immunosuppression so that the host can get back to homeostasis. Specialized Pro-resolving Mediators (SPMs) are endogenously- produced fatty acids that resolve infectious inflammation without being immunosuppressive. We hypothesize that an SPM – Resolvin D2 (RvD2) – can augment exhausted macrophage function during the immunosuppressive phase of sepsis. We developed a two-hit model to establish macrophage exhaustion in vitro, and found that RvD2 increased NF-κB activity, …

Hormetic Modulation Of On Mtor Mitochondria Cross Talk For Mitigation Of Cellular Aging, Mahalakshmi R

Theses and Dissertations

Cellular aging is a gradual process involving structural and functional deterioration of cells. Mitochondria, the biological clock in cells, are known to play a crucial role in the progression of cell aging. According to the mitochondrial free radical theory of aging, oxidative phosphorylation in the mitochondria produces free radicals, such as, reactive oxygen species (ROS), which lead to oxidative stress in cells. This, in turn, results in mitochondrial dysregulation, and eventually causes degeneration of cellular components, thereby propagating cell aging. However, it is to be underscored that aging, at its core, is a multifaceted phenomenon that involves a number of …

Sphingosine Kinase 2 Depletion Dysregulates Hepatic Redox Metabolism And Enhances Inflammation In Early Metabolic Dysfunction-Associated Steatohepatitis (Mash), Kaitlyn Georgene Jackson

Theses and Dissertations

Metabolic dysfunction-associated steatotic liver disease (MASLD) currently affects one in three people worldwide; its prevalence is growing alongside other cardiometabolic disorders. Aberrations to redox and sphingolipid metabolism contribute to MASLD pathologic progression. Sphingosine-1-phosphate (S1P) is an active lipid, meaning that S1P participates in biochemical processes within the cell. S1P is generated by two distinct isoenzymes, sphingosine kinase (SphK)1 and SphK2. The localization of the SphK enzyme dictates S1P function. While cytosolic SphK1-generated S1P is well-characterized, nuclear and mitochondrial SphK2-generated S1P is less known. Moreover, SphK2 depletion effects on cellular redox processes and inflammation are not well-defined.

This study defines the …

Plk1 Overexpression Drives Tumorigenesis In A Prostate Cancer Mouse Model, Emile Kachouh

Theses and Dissertations

Prostate cancer is the leading cause of cancer-related deaths among men worldwide, and the development of resistance to existing treatments necessitates the exploration of new therapeutic strategies, including combination therapies. This study investigates the role of Polo-like kinase 1 (PLK1), located on chromosome 16p12.2, as an oncogene in prostate cancer. We generated a transgenic mouse model with prostate-specific overexpression of PLK1 to closely mimic human prostate cancer progression. Quantitative PCR (qPCR) analysis was employed to characterize the molecular profile of PLK1, revealing its implication in multiple pathways. To further elucidate the functional consequences of PLK1 overexpression, we confirmed phenotypic progression …

Investigating The Regulation Of Epithelial-Mesenchymal Transition Through Fibronectin-Mediated Tgf-Β1 Mechanotransduction Using In Vitro Models Of Triple-Negative Breast Cancer, Michael M. Sofroniou

Theses and Dissertations

TGF-β1 is a potent regulator of epithelial-mesenchymal transtion (EMT), a cellular
transdifferentation process that promotes cellular motility and matrix remodeling, critical to tumorigenesis and metastasis. TGF-β1-induced EMT promotes the assembly of FN, which synergistically binds latent TGF-β1 to aid in its activation. The purpose of of this work is to further probe the effects of autocrine TGF-β1 signaling during EMT progression by utilizing CRISPR-Cas9 deletion of the TGFB1 gene in in vitro models of triple-negative breast cancer. The studies outlined in this work demonstrate that autocrine TGF-β1 maintains a baseline level of mesenchymal marker expression. It also functions to desensitize …

Role Of Human Intermediate Form Prl Receptor I-Tail In The Pathogenesis Of Breast Cancer, Shanwei Shen

Theses and Dissertations

Breast cancer continues to be the second most common cancer in women in the United States. The neuroendocrine hormone human prolactin (hPRL) plays an important role in normal mammary gland development and growth, stimulating normal breast tissue proliferation and differentiation. Considerable evidence has shown that hPRL is involved in the malignant transformation of human breast tissue. hPRL enhances viability, invasiveness, and proliferation of breast cancer cells in vitro. Evidence from epidemiologic and genetic studies also implicates role of hPRL in the pathogenesis of breast cancer. Its cognate receptor the human prolactin receptor (hPRLr) is required for the action of hPRL. …

Nanoscale Modeling Of Membrane Systems Under Mechanical Deformation In Traumatic Brain Injury Using Molecular Dynamics, Anh Thi Ngoc Vo

Theses and Dissertations

Neuronal membrane disruption and mechanoporation are nanoscale damage mechanisms that critically affect brain cell viability during traumatic brain injury (TBI). These nanoscale cellular impairments are elusive in experiments and necessitate in silico approaches such as molecular dynamics (MD) simulations. Implementing MD, this research aims to investigate the effects of different key factors related to membrane deformation and damage, including force field resolutions, lipid compositions, and loading conditions.

To examine the impact of force field resolution, MD deformation simulations were conducted on 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC) lipid bilayer membranes, using all-atom (AA), united-atom (UA), and coarse-grained Martini (CG-M) force fields. The mechanical responses …

Studies Of Intracellular Trafficking Of Phospholipids Triggered By Osh6, Ilham Hassoon Kadhim

Theses and Dissertations

Yeast vacuoles (mammalian lysosomes) and their closely related organelle late endosomes (LE) play a central role in anti-aging processes since they host the target of rapamycin complex 1 (TORC1). A recent study showed that the vacuolar TORC1 stimulates protein synthesis and cell growth while the late endosomal TORC1 inhibits autophagy, an anti-aging process. This raises a question as to which membrane trafficking pathways toward LE/vacuoles are critical in controlling endosomal TORC1 and anti-aging processes. Members of the family of oxysterol-binding proteins mediate non-vesicular lipid transport between membranes and contribute to longevity in different manners. We previously found that a 2-fold …