Cell Biology Commons^™

A Review Of Rheb Activation Of Mtorc1 And The Great Mystery Of One Missing Gef, Jack Gregory

Senior Honors Theses

The mTORC1 pathway is involved in the regulation of cell growth and translation. The pathway has a complex web of activators and inhibitors to activate mTORC1. mTORC1 is regulated via a small GTPase called Rheb, which interacts directly with mTORC1. This GTPase and its GTPase activating protein (GAP), TSC1/2, have been widely studied to understand how the variety of regulators of mTORC1 interact with these proteins. Despite this, the guanine nucleotide exchange factor (GEF) of Rheb has yet to be identified. This review broadly analyzes Rheb and mTORC1, their structures, regulations, and interactions, and explores the mystery of the missing …

Atlas-Based Analysis Of The Neural Projections From The Lateral Hypothalamic Area To The Lower Brainstem In The Adult Male Rat, Jessica Valeria Salcido Padilla

Open Access Theses & Dissertations

Within the last decade, the number of diseases associated with dysregulation of the neural circuits responsible for energy balance, glucosensing, and feeding control has increased. One brain region containing these circuits is the lateral hypothalamic area (LHA), which plays an important role in the sleep/wake cycle, energy balance, and motivated behavior. Although the LHA has been termed a â??feeding centerâ??, other regions within the hindbrain are known for the regulation of similar functions including energy balance, glucosensing, and feeding control. While many studies have explored and reported projections from the LHA to the hindbrain, few have further investigated the interconnections …

Cellular Mechanisms Of Embryonic Eye Regrowth In Xenopus Laevis, Randolph L. Grell

UNLV Theses, Dissertations, Professional Papers, and Capstones

The African Clawed Frog, Xenopus laevis, has been an indispensable model organism for over 100 years in the study of embryogenesis and development. In recent years, this vertebrate model has emerged as a robust tool for deciphering the cellular and molecular mechanisms underlying various modes of tissue, limb, and organ regeneration. In the context of eye repair, Xenopus offers a unique model, where the adult frog eye has limited regenerative capacity compared to its pre-metamorphic embryonic and tadpole forms, which exhibit a robust capacity for regrowth. Understanding the intricate molecular mechanisms that underlie this developmental shift in regrowth ability …

Syntaxin-3 Mediates Baseline And Stimulated Mucin Secretion, Brianne Wharton

Dissertations and Theses (Open Access)

There are two rates at which airway epithelial cells secrete mucin. The low baseline rate accounts for ciliary clearance, and the high stimulated rate obstructs airways in protection from helminths or in obstructive pulmonary diseases. The exocytosis of mucins occurs via the four-helix SNARE complex. The SNARE proteins contributing helices are the vesicle-SNARE VAMP, and the target-SNAREs SNAP and Syntaxin. Coiling of the complex fuses the granule and plasma membranes to release mucins into the extracellular space. The VAMP and SNAP isoforms mediating baseline and stimulated secretion are known, but the Syntaxin (Stx) isoform remains unknown.

Three candidate exocytic Stx, …

Mesenchymal Stromal Cell Response To Degenerated Intervertebral Disc-Like Ph, Kyle Cannon

All Dissertations

Intervertebral disc degeneration (IVDD) has become increasingly prevalent and is a common contributing factor to low back pain. There are currently no clinical treatment options for IVDD that alleviate the symptoms of IVDD while simultaneously promoting repair of IVD tissue. One treatment option being explored is intradiscal administration of mesenchymal stromal cells (MSCs). However, the microenvironment of the degenerating IVD places significant stress on both native IVD cells and implanted cells. There are several questions that need to be addressed which may help further inform the development of efficacious intradiscal MSC therapies for IVDD. These questions include: 1) Do MSCs …

Exploring Novel Nutrient Acquisition Mechanisms For Maintaining Energy Metabolism In Toxoplasma Gondii, Melanie Key

All Dissertations

Toxoplasma gondii is an infectious intracellular parasite that establishes infection within various mammalian hosts, including humans. Toxoplasma infects approximately one-third of the global population, making it an impactful pathogen of study. T. gondii is the causative agent of toxoplasmosis, an opportunistic infection that causes severe illness or fatality in immunocompromised individuals or pregnant women. The parasite possesses a very effective invasion strategy, allowing it to cross different tissue types to disseminate infection across the placental and blood-brain barrier. Although there are a few treatments for acute toxoplasmosis, these drugs can produce adverse side effects. These options are not effective against …

Differential Expression Of Microrna Mir-145 And Mir-155 Downstream Targets In Oral Cancers Exhibiting Limited Chemotherapy Resistance, Conner Belnap

UNLV Theses, Dissertations, Professional Papers, and Capstones

Background: New evidence has suggested that non-coding microRNAs play a significant role in mediating and modulating chemotherapy resistance, particularly among oral cancers. One recent study found that the expression of miR-145 and lack of miR-155 expression strongly correlated with a limited chemotherapy resistance to Cisplatin, 5-Fluorouracil and Paclitaxel , although the mechanism(s) responsible for these observations remain unidentified.

Methods: Using commercially available cell lines of oral squamous cell carcinoma (OSCC), RNA was isolated using phenol:chloroform extraction. The isolated RNA was converted into cDNA by reverse transcription and subsequently screened for the presence or absence of downstream targets of miR-145 and …

Regulation Of Embryonic Eye Regrowth In Xenopus Laevis, Dylan Guerin

UNLV Theses, Dissertations, Professional Papers, and Capstones

Regrowth of lost organs and tissues is an amazing ability that some animals possess. For regrowth to be considered full, the organism must regrow the organ or tissue to a state that is structurally and functionally similar to that which was lost. The ability of an organism to regrow lost or damaged tissue varies among animals, both in the mechanisms utilized to achieve regrowth, and in what body parts can be regrown. Potentially even closely related species can vary wildly in regenerative ability. Therefore, regenerative research can look to other tissues and organisms for direction in elucidating the mechanisms through …

The Expression Of Recombinant Cas9 Proteins In E. Coli Bl21(De3) Strains, Morgan Reese

Graduate Theses and Dissertations

Abstract Extensively used for genome editing, CRISPR-Cas9 is a relatively new tool that has made a major impact in the genomic engineering landscape. Due to this, the production of CRISPR proteins that are not commercially available can limit research applications. Here, we present methods for optimizing laboratory scale production of CRISPR proteins including Cas9. The method uses IPTG to induce gene expression of the specified Cas9 and nickel column purification to isolate proteins. CRISPR proteins are validated for purity by SDS-PAGE gel, western blot, and for activity by in vitro digestion. We thoroughly validate and compare the effectiveness of BL21(DE3) …

Qualitative Assessment Of Human Embryonic- And Induced Pluripotent Stem Cell Derived Neural Stem Cells Under Cgmp Methods, Michelle Hernandez

Electronic Theses, Projects, and Dissertations

Neural stem cell therapies represent a promising tool for the development of regenerative medicine and are being tested in clinical trials for several neurological disorders. However, the clinical applicability of stem cell therapies is dependent on the implementation of current good manufacturing practices (cGMPs) to ensure the quality, safety, and consistency that stem cell products need to meet FDA regulatory requirements. As such, there is a need for a shift to xeno-free methodologies so experimental conditions are cGMP compliant. The purpose of this study is to test a GMP compatible production method to generate multipotent neural stem cells (NSCs) from …

Simvastatin Induces Autophaghy-Mediated Cell Death In Metastatic Breast Cancer Cells, Jessica Allagoa

Theses (2016-Present)

Breast cancer remains one of the leading causes of cancer deaths among women. Due to the limited effectiveness of current anticancer drugs, ongoing research has extended towards alternative drug categories for potential treatments. Recent findings indicate that statins possess the ability to suppress tumors across various cell types. Traditionally, statins are known as a class of cholesterol-lowering agents and function by inhibiting 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, a key enzyme in the mevalonate pathway. However, statins can also suppress cell proliferation and ultimately lead to cell death, which includes Type I apoptosis-induced cell death or Type II autophagy-induced cell death. Autophagy is …

Foxo1 Inhibitor, As1842856, Induces Cell Cycle Arrest And Reverses Anticancer Drug-Induced Cytotoxicity In Osteosarcoma Cells, Antanay Hall

Theses (2016-Present)

Forkhead box class O (FOXO)-1 transcription factor controls cell proliferation, apoptosis, oxidative stress, and other cellular activities; FOXO1 has also been implicated in cell cycle regulation. This research project aims to determine the contribution of FOXO1 to cell cycle regulation and response to anticancer drug treatment in osteosarcoma. Osteosarcoma is the most common bone cancer, with most cases occurring in people younger than 30 years old. The study explores the impact of FOXO1 inhibitor AS1842856 on the cytotoxic effects of anticancer drugs in CCHOSD, Hos, and LM7 osteosarcoma (OGS) cell lines. Following chemical inhibition of FOXO1 and anticancer drug treatment, …

Loss Of Tumor Suppressor Tmem127 Drives Ret-Mediated Transformation Through Disrupted Membrane Dynamics, Timothy J Walker, Eduardo Reyes-Alvarez, Brandy D Hyndman, Michael G Sugiyama, Larissa C B Oliveira, Aisha N Rekab, Mathieu J F Crupi, Rebecca Cabral-Dias, Qianjin Guo, Patricia L M Dahia, Douglas S Richardson, Costin N Antonescu, Lois M Mulligan

Faculty, Staff and Student Publications

Internalization from the cell membrane and endosomal trafficking of receptor tyrosine kinases (RTKs) are important regulators of signaling in normal cells that can frequently be disrupted in cancer. The adrenal tumor pheochromocytoma (PCC) can be caused by activating mutations of the rearranged during transfection (RET) receptor tyrosine kinase, or inactivation of TMEM127, a transmembrane tumor suppressor implicated in trafficking of endosomal cargos. However, the role of aberrant receptor trafficking in PCC is not well understood. Here, we show that loss of TMEM127 causes wildtype RET protein accumulation on the cell surface, where increased receptor density facilitates constitutive ligand-independent activity and …

Development Of Vasculature Patterns In A Mouse Model Of Supratentorial Ependymoma, Jackson Ayers

Honors Scholar Theses

Supratentorial Ependymoma (ST-EPN) is a subtype of ependymoma, a primary solid tumor found throughout the nervous system. ST-EPN are most commonly caused by an oncogenic fusion between the zinc finger gene ZFTA and the RELA, and this distinct ependymoma subtype is readily modeled in mice by conditional expression of ZFTA-RELA in radial glial cells. ST-EPN are known to have a distinctive arrangement of tumor cells and vasculature forming pseudo-rosettes in which polarized tumor cells surround blood vessels within the tumors. It is not known how these pseudo-rosettes or the tumor vasculature form and develop in ST-EPN, so in this study …

Ammonium Chemotaxis In Chlamydomonas Reinhardtii, Gabela Nelson

LSU Doctoral Dissertations

Analysis of ammonium chemotaxis in Chlamydomonas reinhardtii is largely hindered, compared to that of phototaxis, despite equal importance on flagellated microalgal physiology. A major contribution of this shortfall is the lack of proper assay method. We developed a simple Petri dish assay method in which light is homogenously exposed while patterns of the cellular migration are tracked with a function of time. Using the method, new findings were revealed. First, this research presented that a strain lacking the eyespot organelle required for light gradient-sensing exhibits similar chemotactic behavior compared to a wild-type strain, suggesting Chlamydomonas sense an ammonium gradient not …

Upregulation Of The Predominant Cystic Fibrosis Causing Mutation Df508-Cftr By Triazole Compounds In Epithelial Cells, Maggie Taylor

Undergraduate Research Conference

Cystic fibrosis is a common genetic disease that is caused by a mutation in the plasma membrane protein CFTR, which stands for Cystic Fibrosis Transmembrane-conductance Regulator. When this membrane protein is mutated, it impairs its chloride ion channel function, blocking the movement of chloride ions that travel in and out of the cell. Previous studies have demonstrated that the most prevalent CFTR mutation, ∆F508-CFTR, can be partially reversed using small molecules (Heda and Marino, BBRC, 271:659-664, 2000). In this study, I have investigated the effects of several triazole compounds known to bind and transport chloride ions in cultured cells, on …

Hgs-3 The Influence Of A Tandem Cycling Program In The Community On Physical And Functional Health, Therapeutic Bonds, And Quality Of Life For Individuals And Care Partners Coping With Parkinson’S Disease, Leila Djerdjour, Jennifer L. Trilk

SC Upstate Research Symposium

Purpose Statement: Several studies have shown that aerobic exercise can have a positive impact on alleviating symptoms experienced by individuals with Parkinson's disease (PD). Despite this evidence, the potential benefits of exercise for both PD patients and their care partners (PD dyad) remain unexplored. This research project investigates the effectiveness, therapeutic collaborations, and physical outcomes of a virtual reality (VR) tandem cycling program specifically designed for PD dyads.

Methods: Following approval from the Prisma Health Institutional Review Board, individuals with PD were identified and screened by clinical neurologists. The pre-testing measures for PD dyads (N=9) included emotional and cognitive status …

Role Of Centrosomal P4.1 Associated Protein (Cpap) In Tumor Suppression, Heena Dave

MUSC Theses and Dissertations

In eukaryotic cells, centrosomes are membrane-less organelles that function as the primary microtubules organizing center with a crucial role in cell division. For accurate bipolar spindle assembly and genetic transmission between generations, fidelity in centriolar duplication is critical. Disruption in this process can cause genomic instability, which could then lead to conditions like aneuploidy, a common feature of various cancers. Among the numerous proteins associated with mammalian centrioles, the centrosomal P4.1 associated protein (CPAP) stands out for its essential role in regulating centriole duplication. Dysfunctions in CPAP have been linked to abnormalities in centriole length that can contribute to conditions …

Role Of Protein Kinase A And A Kinase Anchoring Proteins In Buffering And Compartmentation Of Camp Signalling In Human Airway Smooth Muscle Cells, Rinzhin T. Sherpa, Karni S. Moshal, Shailesh R. Agarwal, Rennolds S. Ostrom, Robert D. Harvey

Pharmacy Faculty Articles and Research

Background and Purpose

In human airway smooth muscle (hASM) cells, not all receptors stimulating cAMP production elicit the same effects. This can only be explained if cAMP movement throughout the cell is restricted, yet the mechanisms involved are not fully understood. Phosphodiesterases (PDEs) contribute to compartmentation of many cAMP responses, but PDE activity alone is predicted to be insufficient if cAMP is otherwise freely diffusible. We tested the hypothesis that buffering of cAMP by protein kinase A (PKA) associated with A kinase anchoring proteins (AKAPs) slows cAMP diffusion and that this contributes to receptor-mediated, compartmentalized responses.

Experimental Approach

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The Plant Disease Triangle Facing Climate Change: A Molecular Perspective, Charles Roussin-Léveillée, Christina A. M. Rossi, Christian Castroverde, Peter Moffett

Biology Faculty Publications

No abstract provided.

Pulsed Electric Fields Sensitize Methicillin-Resistant Staphylococcus Aureus To Antibacterial Therapies And Stimulate Host Immune Responses, Alexandra E. Chittams-Miles

Biomedical Sciences Theses & Dissertations

This research explores the impact of nanosecond pulsed electric fields (nsPEF) on two fronts: their immune stimulatory effects and their potential as a novel strategy to enhance the sensitivity of Methicillin-resistant Staphylococcus aureus (MRSA) to clinically relevant antibiotics. While pulsed electric fields have been reported to have an immune stimulatory effect, the mechanisms responsible for these effects have yet to be determined.

Our investigation addresses the rising concern of MRSA derived skin and soft tissue infections (SSTIs). Consistent with other publications, we found that nsPEF alone cause modest inactivation of planktonic MRSA. We then investigated the effects of nsPEF in …

Autophagy And Ime2 Kinase In Regulation Of Meiotic Exit In Saccharomyces Cerevisiae, Somdutta Paul

Dartmouth College Master’s Theses

Meiosis or gametogenesis is a specialized cell division that produces gametes in sexually reproducing organisms. The process of meiosis reduces the genetic content into half that of the progenitor cell. This reduction in the genetic content occurs over a set of two divisions: meiosis I and meiosis II. Because gametes are essential for propagation of life, meiosis operates under tight regulation ensuring the full functionality and viability of the gametes produced. The working principle of the regulatory network that restricts meiosis to only two divisions is not clearly understood. Budding yeast undergoes meiosis in response to starvation. Autophagy being a …

Deciphering The Functional Connections Between The Nuclear Paraspeckle And Rad51 Homologous Recombination Proteins Using A Yeast Protein Interaction System, Eric J. Nutz

Senior Theses

Homologous recombination (HR) is a repair pathway for DNA double-stranded breaks. Mutations in HR genes contribute to genomic instability and increase the prevalence of cancer. Exploiting HR deficiency in tumor cells has led to improved synthetic lethality outcomes. RAD51 paralogue protein complexes are known to be involved with HR. Proteomic analysis of RAD51 paralogues reveals a connection to the nuclear paraspeckle. A paraspeckle is a little-known, specialized organelle found in the interchromatin space of the nucleus in mammalian cells. Its three central protein components include SFPQ, NONO, and PSPC1. RAD51D is an HR protein shown previously to interact with SFPQ …

Formation Of New Cohesive Linkages And Regulation Of Cohesion Rejuvenation During Meiotic Prophase In Drosophila Oocytes, Muhammad Abdul Haseeb

Dartmouth College Ph.D Dissertations

During meiosis, faithful segregation of chromosomes requires maintenance of sister chromatid cohesion from premeiotic S phase until its stepwise dissolution at anaphase I and anaphase II. Research in humans and model organisms indicates that premature loss of meiotic cohesion is a major determinant of age-induced aneuploidy in human oocytes, a phenomenon known as the maternal age effect. Because cohesin turnover after S phase has not been detected in mice oocytes, the prevailing model for mammalian oocytes is that cohesion cannot be replenished after its initial establishment in S phase. However, previous research from the Bickel lab suggested that a cohesion …

In Silico Analysis Of C-Type Lectins As Co-Infection Receptors Of Dengue And Chikungunya Viruses In Aedes Aegypti, Munawir Sazali, R. C. Hidayat Soesilohadi, Nastiti Wijayanti, Tri Wibawa, Arif Nur Muhammad Ansori

Makara Journal of Science

Aedes aegypti is a primer vector of dengue virus (DENV) and chikungunya virus (CHIKV). The susceptibility of mosquitoes to DENV and CHIKV depends on their recognition receptor of pathogens. C-type lectins (CTLs) are an important mediator of virus infection in A. aegypti. This study aims to identify potential receptors and determine the binding affinity between ligand–receptor interaction, CTLs and virus envelopes (DENV-1, 2, 3, and 4 and CHIKV) interaction based on in silico analysis. Sample sequences were obtained from GenBank (NCBI), and 10 CTLs were acquired from VectorBase. Homology modeling based on a minimum standard of 20% was processed …

Honey Targets Ribosome Biogenesis Process In Human Pancreatic Cancer Cells To Inhibit Their Growth And Metastatic Phenotypes, Aun A. Bangash, Muhammad Bangash, Haider Ahsan, Shiza Khan, Mudassier Ahmad, Dae Joon Kim, Sahir Alvi, Bilal Hafeez

Research Symposium

Background: Pancreatic cancer (PanCa) is the fourth deadliest cancer worldwide and is expected to become the second deadliest cancer by 2030. In the USA, the National Cancer Institute put forth a grim prediction stating that there will be 64,050 new cases in 2023 alone and about 50,000 of these patients will die. Existing therapeutic regimens against PanCa are not that effective and show unacceptable toxicities. Therefore, developing highly effective new agents with less toxicity is urgently required, which could be used as a monotherapy or as an adjuvant to treat PanCa patients. Honey is known for its tremendous health benefits …

Real-Time Camp Dynamics In Live Cells Using The Fluorescent Camp Difference Detector In Situ, Isabella Cattani-Cavalieri, Jordyn Margolis, Camelia Anicolaesei, Francisco J. Nuñez, Rennolds S. Ostrom

Pharmacy Faculty Articles and Research

cAMP Difference Detector In Situ (cADDis) is a novel biosensor that allows for the continuous measurement of cAMP levels in living cells. The biosensor is created from a circularly permuted fluorescent protein linked to the hinge region of Epac2. This creates a single fluorophore biosensor that displays either increased or decreased fluorescence upon binding of cAMP. The biosensor exists in red and green upward versions, as well as green downward versions, and several red and green versions targeted to subcellular locations. To illustrate the effectiveness of the biosensor, the green downward version, which decreases in fluorescence upon cAMP binding, was …

Valproic Acid Alters Larval Behavior And Neuronal Composition Within The Optic Tectum Of Zebrafish, Bailey J. Calder, Jacquelyne C. Howell, Michael J. Zeyer, Annalie Martin, Sierra C. Dixon, Shane M. Lilya, Jason M. Hansen, Arminda Suli

Library/Life Sciences Undergraduate Poster Competition 2024

The mammalian superior colliculus (SC) and its non-mammalian homolog–the optic tectum (OT)–are midbrain structures that integrate multimodal sensory inputs and guide involuntary movements in response to relevant environmental cues. Recent work has drawn strong connections between the functions of the SC/OT and behavioral deficits observed in autism spectrum disorder (ASD), thus implicating this structure as a possible site affected in ASD. Since fetal exposure to valproic acid (VPA) has been associated with increased prevalence of ASD in humans, and ASD-like phenotypes in animal models, we exposed embryonic zebrafish to VPA to investigate the connection between ASD and OT development. In …

Whole Genome Sequencing Of The Whipple Azalea Garden, Afia Asamoah, Elizabeth Toth, Amy Vasudevan, Sarah Justice, Elizabeth D. Hasenmyer

Lux et Fides: A Journal for Undergraduate Christian Scholars

Taylor University houses a large collection of North American azaleas. Deciduous azalea species, like those found on campus, are vastly understudied. This project aims to provide publicly available genomic data which will be used to study the genetic basis behind their physical characteristics and their relatedness to other species.

Mir-200c Reprograms Fibroblasts To Recapitulate The Phenotype Of Cafs In Breast Cancer Progression, Zhao Lin, Megan Roche, Víctor Díaz-Barros, Marina Domingo-Vidal, Diana Menezes, Madalina Tuluc, Guldeep Uppal, Jaime Caro, Joseph Curry, Ubaldo Martinez-Outshoorn

Kimmel Cancer Center Faculty Papers

Mesenchymal-epithelial plasticity driving cancer progression in cancer-associated fibroblasts (CAFs) is undetermined. This work identifies a subgroup of CAFs in human breast cancer exhibiting mesenchymal-to-epithelial transition (MET) or epithelial-like profile with high miR-200c expression. MiR-200c overexpression in fibroblasts is sufficient to drive breast cancer aggressiveness. Oxidative stress in the tumor microenvironment induces miR-200c by DNA demethylation. Proteomics, RNA-seq and functional analyses reveal that miR-200c is a novel positive regulator of NFκB-HIF signaling via COMMD1 downregulation and stimulates pro-tumorigenic inflammation and glycolysis. Reprogramming fibroblasts toward MET via miR-200c reduces stemness and induces a senescent phenotype. This pro-tumorigenic profile in CAFs fosters carcinoma …