Cell Biology Commons^™

Characterizing Ferroptosis Pathways In In Vitro Motor Neuron Models, Alejandra Martinez

Theses and Dissertations

Ferroptosis is a non-apoptotic regulated form of cell death driven by the toxic accumulation of lipid peroxides and the presence of iron. The mechanism by which ferroptosis operates requires further investigation; here I will discuss the findings regarding the role of ferroptosis in different cellular models as well as the genes that may be involved with either promoting or hindering the ferroptotic pathway. NSC-34 is a hybrid cell line of neuroblastoma and primary spinal cord cells that can be differentiated into a motor neuron-like state allowing the characterization of ferroptosis in two distinct cellular conditions. Additionally, iNIL cells are a …

Expansion Microscopy To Visualize Cell-Cycle Events In The Abbreviated Cell Cycle In Caenorhabditis Elegans (Roundworm) Germline Stem Cells, Taylor Campbell

Master's Theses and Doctoral Dissertations

The abbreviated cell cycle is a poorly understood form of the cell cycle essential for genome stability in stem cells. To visualize cell-cycle events in the abbreviated cell cycle, we optimized a protocol for expansion microscopy in stem cells of the reproductive system of the model organism C. elegans. Optimizations included development of new mounting techniques and modifications to DNA staining methods. These optimizations produced brighter samples that were easier to find and focus on at the microscope. These optimizations, combined with future labeling of DNA replication, will expand our understanding of how cells with an abbreviated cell cycle maintain …

Fxs-Causing Point Mutations In Fmrp Disrupt Neuronal Granule Formation And Function, Emily L. Starke

Electronic Theses and Dissertations

Fragile X Syndrome (FXS) is a neurodevelopmental disorder caused by the disruption of Fragile X Mental Retardation Protein (FMRP) function in neurons, affecting nearly 1 in 7,500 individuals. Although FXS typically occurs from a complete loss of FMRP expression due to a CGG trinucleotide expansion within the 5’UTR of the FMR1 gene, single nucleotide polymorphisms (SNPs) within the KH domains of FMRP have been shown to severely disrupt FMRP function. FMRP is an RNA-binding translation repressor that interacts with ~4% of the neuronal transcriptome. Many target mRNAs encode for proteins important for regulating synaptic processes and modulate synaptic plasticity. It …

Intestinal Endothelial Cells Promote Hiv-1 Infection In Resting Cd4+ T-Cells Without Causing T-Cell Activation, Jessica Eddy, Rachel Chee, Esther Park, Anding Shen

Summer Research

It is generally understood that HIV-1 does not effectively infect resting CD4+ T cells, and latent infection in those cells may arise when activated infected CD4+ T Cells return to a resting state. However, we found that stimulation by intestinal endothelial cells (IEC) can render resting CD4+ T cells permissible for direct HIV infection. Upon infection, these stimulated T cells remain largely phenotypically inactivated. This study was centered around HIV-1 infection in the context of intestinal tissues, as HIV has extensive gut pathology. Endothelial cells are abundant in mucosal tissues and would have direct, constant interactions with CD4+ T Cells …

Association Between Plasma Genistein And Health-Related Quality Of Life In Breast Cancer Survivors, Tran Pham

Honors Undergraduate Theses

According to the American Cancer Society, breast cancer is the most commonly diagnosed cancer and is the second leading cause of cancer death in American women. Breast cancer screenings and improvement in treatments have resulted in the rising number of survivors in the recent decade. This urged the need for post-diagnosis lifestyle changes to improve breast cancer patients' quality of life. Many studies found soy food, the primary dietary source of phytoestrogens, has a protective effect against breast cancer recurrence and mortality. Dietary phytoestrogens can be classified into two groups: isoflavones and lignans. Daidzein and genistein were identified as the …

Tracking The Subcellular Localization Of Surface Proteins In Staphylococcus Aureus By Immunofluorescence Microscopy, Salvatore J. Scaffidi, Mac A. Shebes, Wenqi Yu

Molecular Biosciences Faculty Publications

Surface proteins of Staphylococcus aureus and other Gram-positive bacteria play essential roles in bacterial colonization and host-microbe interactions. Surface protein precursors containing a YSIRK/GXXS signal peptide are translocated across the septal membrane at mid-cell, anchored to the cell wall peptidoglycan at the cross-wall compartment, and presented on the new hemispheres of the daughter cells following cell division. After several generations of cell division, these surface proteins will eventually cover the entire cell surface. To understand how these proteins travel from the bacterial cytoplasm to the cell surface, we describe a series of immunofluorescence microscopy protocols designed to detect the stepwise …

Dcaf14 Promotes Stalled Fork Stability To Maintain Genome Integrity, Arik Townsend, Gabriella Lora, Justin Engel, Neysha Tirado-Class, Huzefa Dungrawala

Molecular Biosciences Faculty Publications

No abstract provided.

The Characterization Of The Function(S) Of Crag In Basement Membrane Polarity, Hemin Pankajkumar Shah

Graduate Research Theses & Dissertations

The abundant epithelial cells play various roles in the development and maintenance of an organism, and their apical-basolateral polarity is a unique characteristic that is imperative to their function and integrity. This polarity is maintained via various environmental cues and tightly regulated intracellular trafficking, where the presence of the basement membrane (BM) provides a basal cue. The BM is a specialized extracellular matrix (ECM) secreted by the epithelial cells, which accumulates on the basal side and serves as their mechanical anchorage. Although the BM is of paramount importance in the apical-basolateral polarity and the loss of BM’s integrity is a …

Stobe Photography Mapping Of Cell Membrane Potential With Nanosecond Resolution, Allen S. Kiester, Bennett L. Ibey, Zachary N. Coker, Andrei G. Pakhomov, Joel N. Bixler

Bioelectrics Publications

The ability to directly observe membrane potential charging dynamics across a full microscopic field of view is vital for understanding interactions between a biological system and a given electrical stimulus. Accurate empirical knowledge of cell membrane electrodynamics will enable validation of fundamental hypotheses posited by the single shell model, which includes the degree of voltage change across a membrane and cellular sensitivity to external electric field non-uniformity and directionality. To this end, we have developed a high-speed strobe microscopy system with a time resolution of ~ 6 ns that allows us to acquire time-sequential data for temporally repeatable events (non-injurious …

Impact Of Targeting Glycosylated Ceramides On Tumorigenic Properties, And Characterization Of Sphingolipids In Head And Neck Tumors, Katherine E. Hylton

Theses and Dissertations

Sphingolipids play a crucial role in signaling, membrane structure, and migration, making them important molecules in cancer development, metastasis, and drug resistance. While some sphingolipids have been associated with pro-apoptotic or pro-survival behaviors, the role of many sphingolipids in cancer remains poorly defined. Chapter 1 of this study investigated the impact of three enzymes that compose most of the ceramide to Lc3 ceramide pathway – UGCG, GBA, and B3GNT5 – and how their alteration impacts chemoresistance and basal membrane invasion in vitro. It was found that the CΒE-induced inhibition of GBA, which converts glucosylceramide to ceramide, has no effects on …

Mimicking The Effect Of Prolactin On Stat3/Stat5 Activity In Breast Cancer, Jennifer N. Barbuto, Sarah R. Walker

Honors Theses and Capstones

Signal transducers and activators of transcription (STAT) 3 and 5 are commonly constitutively activated in breast cancer. STAT5 can outcompete STAT3 and reduce cell proliferation and metastasis. STAT5 activation is stimulated by prolactin, a natural hormone that can be harmful at high levels. The aim of this study is to identify some possible previously developed drugs that mimic the effect of prolactin and STAT5 without the added risk in MDA-MB231 breast cancer cells. Using the CLUE database query app and STAT5 up- and downregulation signatures, three drugs (X, K, and M) were chosen based on their similarity in signatures to …

Exploring The Connection Between The Spontaneous Regression Seen In Neuroblastomas, Hypertumors, And Reactive Oxygen Species, Shahad Musa, Manitha Mulpuru

AUCTUS: The Journal of Undergraduate Research and Creative Scholarship

Peto’s Paradox is defined as the lack of correlation between larger animals and cancer risk. Under the assumption that all cells have equal risk of becoming cancerous, larger animals should have greater rates of cancer. However, the inverse is true. Determining the cause of this variation may allow a supplemental approach to cancer treatment. A combination of two reasons may account for this correlation including hypertumors and metabolism. Hypertumors, or cheater cells, are hypothesized to suppress cancer growth through spontaneous autophagic degradation and overexpression of the RAS g-protein. Both of these characteristics are exhibited in Neuroblastomas. An anticancer drug used …

Study Of Primary Cilium Structure And Intraflagellar Transport, Shufeng Sun

Legacy Theses & Dissertations (2009 - 2024)

Primary cilia are hair-like protrusions that stem from the basal bodies in the cytoplasm and extend into the extracellular space to sense signals. Intraflagellar transport (IFT) functions to transport cargo molecules into and out of the ciliary compartment to assemble, maintain, and disassemble the cilia. Accurate knowledge of the three-dimensional (3D) structure of primary cilia and precise details of the IFT profile is the foundation for understanding the sensory functions of primary cilia. This work covers three aspects of primary cilia. Firstly, we obtained and analyzed the overall 3D architecture of the complete primary cilia axoneme region using serial section …

Clinical Significance, Functional Role And Molecular Mechanism Of 2’-O-Methyltransferase Ftsj3 In Promoting Cancer Progression, Morenci Manning-Powell

Wayne State University Dissertations

2’-O-methylation (2’-O-Me), one of the most common modifications within RNA, has multiple roles in modulating RNA structure, stability, and interactions, as well as gene transcription and translation. We previously performed integrative genomic and transcriptomic analysis of 58 RNA methyltransferases, and identified FTSJ3 (FtsJ RNA 2ʹ-O-methyltransferase 3) as significantly amplified/overexpressed in breast cancer. Knockdown of FTSJ3 inhibits breast cancer cell growth in vitro. However, the clinical significance, functional role, and molecular mechanism of FTSJ3 in human cancer remains to be elucidated. In the present study, we first analyzed the differential mRNA and protein expression of FTSJ3 between tumor and normal tissues …

Human Regulatory T Cells Control Inflammation From Effector T Cells In Prediabetes, Rui Liu

Theses and Dissertations--Pharmacy

Type 2 diabetes (T2D) is a chronic low-grade inflammatory disease. A T cell cytokine profile (Th17) from PBMCs can distinguish obese T2D from obese non-diabetes subjects. Individual T cell subsets interact with each other and the diverse subsets jointly determine overall inflammation. Cellular metabolism drives cytokine production of CD4⁺ T cells, and therefore contributes to inflammation in T2D. However, specific changes in metabolism and function of CD4⁺ T cells during the progression from lean healthy to obese and diabetic stages in people have not been clarified.

We hypothesize that human regulatory T cells (Treg) impact metabolism of effector …

Elucidating The Role Of The Tyrosine Phosphatase, Shp-2, In Regulation Of Pd-L1 Expression In Non-Small Lung Cancer Using Both Biochemical Analyses And Real-World Genomic Information, Keller Toral

Theses and Dissertations--Pharmacy

Immune checkpoint inhibitors (ICIs), especially those that target programmed cell death protein 1 (PD-1) and programmed cell death ligand-1 (PD-L1), have been shown to provide substantial clinical benefit in many patients with non-small cell lung cancer (NSCLC). While these therapeutic agents can be highly effective in the correct context, the biological systems that malignant cells draft from normal activities of the cell are poorly characterized. Tumor cell-specific expression of PD-L1 is likely important for clinical benefit from PD-1 and PD-L1 inhibitors. It is known that PD-L1 is inappropriately expressed in many cancers harboring mutations in the RAS family of genes. …

Cop9 Signalosome Component Csn-5 Promotes Accumulation And Function Of Stem Cell Regulators Fbf-1 And Fbf-2, Emily Osterli

Graduate Student Theses, Dissertations, & Professional Papers

RNA-binding proteins FBF-1 and FBF-2 (FBFs) are required for stem cell maintenance in C. elegans, although the mechanisms by which FBFs protein levels are regulated remain unknown. Using a yeast two-hybrid screen, we identified an interaction between both FBFs and CSN-5, a component of the COP9 (constitutive photomorphogenesis 9) signalosome. This highly conserved COP9 complex can affect protein stability through a range of mechanisms including deneddylation, deubiquitination, and phosphorylation (Wolf et al., 2003). Mapping protein-protein interactions between FBFs and CSN-5 suggested that the MPN (Mpr1/Pad1 N-terminal) metalloprotease domain of CSN-5 interacts with the RNA-binding domain of FBFs at physiologically …

Cold-Induced Metabolic Changes In Lean, Nag-1 Transgenic Mice, Rachel J. Davey

All Master's Theses

Obesity is a multifaceted metabolic disorder with severe worldwide public health consequences. While obesity can often be treated using diet and exercise, there are complex genetic interactions driving obesity that don’t always respond to such changes. One important research focus for addressing genetic factors is activating brown adipose tissue which increases thermogenesis, the process of burning stored fats to generate heat. Cold exposure is a known way to activate brown adipose tissue through b3-adrenergic signaling. This signaling pathway causes an upregulation of thermogenesis in brown adipocytes and beige adipocytes, which is white adipose tissue that “browns” and becomes metabolically active. …

Tetraspanins As Potential Therapeutic Candidates For Targeting Flaviviruses, Waqas Ahmed, Girish Neelakanta, Hameeda Sultana

Biological Sciences Faculty Publications

Tetraspanin family of proteins participates in numerous fundamental signaling pathways involved in viral transmission, virus-specific immunity, and virus-mediated vesicular trafficking. Studies in the identification of novel therapeutic candidates and strategies to target West Nile virus, dengue and Zika viruses are highly warranted due to the failure in development of vaccines. Recent evidences have shown that the widely distributed tetraspanin proteins may provide a platform for the development of novel therapeutic approaches. In this review, we discuss the diversified and important functions of tetraspanins in exosome/extracellular vesicle biology, virus-host interactions, virus-mediated vesicular trafficking, modulation of immune mechanism(s), and their possible role(s) …

Self And Microbiota-Derived Epitopes Induce Cd4⁺ T Cell Anergy And Conversion Into Cd4⁺Foxp3⁺ Regulatory Cells, Michal P. Kuczma, Edyta A. Szurek, Anna Cebula, Vu L. Ngo, Maciej Pietrzak, Piotr Kraj, Timothy L. Denning, Leszek Ignatowicz

Biological Sciences Faculty Publications

The physiological role of T cell anergy induction as a key mechanism supporting self-tolerance remains undefined, and natural antigens that induce anergy are largely unknown. In this report, we used TCR sequencing to show that the recruitment of CD4⁺CD44⁺Foxp3⁻CD73⁺FR4⁺ anergic (Tan) cells expands the CD4⁺Foxp3⁺ (Tregs) repertoire. Next, we report that blockade in peripherally-induced Tregs (pTregs) formation due to mutation in CNS1 region of Foxp3 or chronic exposure to a selecting self-peptide result in an accumulation of Tan cells. Finally, we show that microbial antigens from Akkermansia muciniphila …

Protocadherin-17 Expression And Function In Vertebrate Brain: A Literature Review, Mathea Mcguire

Williams Honors College, Honors Research Projects

For this project, I will be doing a systematic review on protocadherin-17 function in vertebrate brain development and function in the last 10 years. Protocadherins are members of cadherin superfamily. Cadherins are calcium-dependent cell adhesion molecules that are implicated to play crucial roles in the information and maintenance of tissues and organs in vertebrate animals. This review will summarize major findings regarding protocadherin-17 expression and function in major model organisms such as zebrafish and mice, as well as results from human studies. It is hoped that this work will be a valuable source for background knowledge of protocadherin-17 function in …

Leveraging Chemical And Computational Biology To Probe The Cellulose Synthase Complex, B. Kirtley Amos

Theses and Dissertations--Plant and Soil Sciences

Cellular expansion in plants is a complex process driven by the constraint of internal cellular turgor pressure by an expansible cell wall. The main structural element of the cell wall is cellulose. Cellulose is vital to plant fitness and the protein complex that creates it is an excellent target for small molecule inhibition to create herbicides. In the following thesis many small molecules (SMs) from a diverse library were screened in search of new cellulose biosynthesis inhibitors (CBI). Loss of cellular expansion was the primary phenotype used to search for putative CBIs. As such, this was approached in a forward …

Traction Force Is Modulated By The Calpain Small Subunit And Secreted Galectin-3, Imjoo Jang

Wayne State University Dissertations

Cell migration is a fundamental physical process for wound repair, innate immune response, embryonic development, inflammatory responses as well as cancer metastasis. Biochemical and mechanical cues present inside and outside the cell can modulate the mechanical aspects of cell migration. During cell migration, traction forces are generated by the contraction of the actomyosin cytoskeleton and transmitted to the extracellular matrix through integrin-mediated focal adhesions, facilitating the forward movement of the cell. Although regulating traction force is central to achieving successful cell migration, the detailed mechanism of the force production is still largely unclear. The calpain family of proteases has been …

Entry And Replication Of Negative-Strand Rna Viruses, Kerri Boggs

Theses and Dissertations--Molecular and Cellular Biochemistry

Hendra virus (HeV) and human metapneumovirus (HMPV) are negative-sense, singled-stranded RNA viruses. The paramyxovirus HeV is classified as a biosafety level 4 pathogen due to its high fatality rate and the lack of a human vaccine or antiviral treatment. HMPV is a widespread pneumovirus that causes respiratory tract infections which are particularly dangerous for young children, immunocompromised individuals, and the elderly. Like HeV, no vaccines or therapies are available to combat HMPV infections. These viruses fuse their lipid envelopes with a cell to initiate infection. Blocking cell entry is a promising approach for antiviral development, and many vaccines are designed …

Reversible Glucan Phosphorylation In The Red Alga, Cyanidioschyzon Merolae, Corey Owen Brizzee

Theses and Dissertations--Molecular and Cellular Biochemistry

Starch and glycogen are an essential component for the majority of species and have been developed to maintain homeostasis in response to environmental changes. Water-soluble glycogen is an excellent source of quick, short-term energy in response to energy demands. In contrast, plants and algae have developed the macromolecule starch that is elegantly suitable for their dependence on external circumstances. Semi-crystalline starch is water-insoluble and inaccessible to most amylolytic enzymes, thus plants and algae have developed a coordinated system so that these enzymes can gain access to the denser starch energy cache. Starch-like semi-crystalline polysaccharides are also found in red algae, …

The Role Of Autophagy And Senescence In The Responses Of Non-Small Cell Lung Cancer Cells To Chemotherapy And Radiation, Nipa H. Patel

Theses and Dissertations

Cancer-associated deaths account for the second-highest mortality rates in the United States. Primary modalities of treatment often include surgery, radiation, and chemotherapy, and may also incorporate targeted therapy and immunotherapy. However, resistance to these treatments remains high, resulting in disease reoccurrence and poor survival rates. While apoptosis or cell death of tumor cells is the ideal outcome for anti-cancer therapy, this is often not the case, and in fact cancer cells may upregulate several pathways, such as autophagy and senescence, as a means to undergo alternative cell fate and evade apoptotic cell death. An essential tumor suppressor gene, TP53, …

Regulation Of Osseous Healing By Macrophage-Derived Wnt Ligands, Jefferson Overlin Abaricia

Theses and Dissertations

Osseous healing is regulated by various classes of cells and signaling mechanisms. Of these, Wnt signaling has long been known to be critically important in directing the differentiation of mesenchymal stem cells (MSCs) into osteoblasts during bone healing. However, the source of these Wnt ligands is not known. Recently, a body of literature has arisen finding both beneficial and detrimental effects of macrophage-derived Wnt ligands on the regeneration of other tissues (liver, kidney, heart, and intestine), often by regulating inflammatory activation and stem cell behavior. As macrophages have been well-characterized as orchestrators of healing, their use of Wnt signaling to …

Molecular Mechanisms Regulating Optic Fissure Fusion During Zebrafish Eye Development, Megan Weaver

Theses and Dissertations--Biology

Vertebrate retinal development requires timely and precise fusion of the optic fissure. Failure of this event leads to congenital vision impairment in the form of coloboma. Recent studies have suggested hyaloid vasculature to be involved in OF fusion. In order to examine this link, we analyzed optic fissure fusion and hyaloid vasculogenesis in the zebrafish pax2a noi mutant line. We first determined that pax2a^-/- embryos fail to accumulate F-actin in the optic fissure prior to basement membrane (BM) degradation. Furthermore, using 3D and live imaging we observed reduced OF hyaloid vascularization in pax2a^-/- embryos. When examining the connection …

Cellular Bioenergetics Regulates Cell Proliferation During Mammalian Regeneration, Sandeep Saxena

Theses and Dissertations--Biology

Mammalian system consists of stress-sensing molecules that regulates their cellular response against damage, injury and oncogenic stress. During vertebrate regeneration, cells responding to injury re-enter the cell cycle and proliferate to form new tissue. Cell cycle re-entry or arrest is at least partly regulated by cellular senescence which negatively impacts the proliferative pool of cells during regeneration. What remains unclear is whether cells in regenerating systems possess an increased propensity to proliferate and are refractory to signals that induce senescence. My thesis work has focused on how fibroblasts from the ear pinna differentially regulate healing in highly regenerative mammals (e.g., …

Molecular And Genetic Studies On A Sipd/Ipad-Related Virulence Spike Protein From Immune-Suppressive Particles Of A Drosophila Parasitoid, Carlo Miguel A. Sevilla

Dissertations and Theses

Parasitoid wasps are effective biological control agents that have evolved intricate host immune suppression strategies to overcome host immune defenses. The most important anti-parasite defense mechanism is encapsulation, where the host’s blood cells surround the wasp egg. In the Drosophila/Leptopilina host-parasitoid system, extracellular vesicles (EVs) are oviposited along with the wasp egg. The EVs possess spikes and contain hundreds of proteins, some of which enable wasp eggs to escape encapsulation by changing the morphology and function of hemocytes, or killing them. Previous studies have identified an abundant surface/spike protein (SSp40) from Leptopilina heterotoma EVs. While p40, a predicted …