Cell Biology Commons^™

Plastics And Their Interactions With Bacterial Biofilms Of Synechococcus Sp. Pcc 7002 And Escherichia Coli Nissle 1917, Jackson Zmich

Open Access Master's Theses

Plastic waste is a leading global pollutant with increasing concerns, as recent studies have shown that these wastes are not only concentrated on a macro scale but on a micro and nano scale. These micro- and nano- sized plastic particles, denoted as MPs and NPs, have been measured in marine and freshwater sources, air, food products, and within biosolids expelled from organisms, including humans. Due to their small size, MNPs are entering organisms through inhalation, ingestion, or dermal absorption. [1] Humans are ingesting MNPs daily, with median rates of approximately 200 ng/capita/day for children and 600 ng/capita/day for adults. [2] …

Dusp8 Gene Expression Is Increased Upon The Stimulation Of Hek293 Cells, Oanh Vo, Lukas Macha

Student Summer Scholars Manuscripts

Dual specificity phosphatase 8 (DUSP8) is one of the phosphatases that oppose the activity of mitogen-activated protein kinases. Previous mouse studies have demonstrated the functional role of DUSP8 in regulating cardiomyocyte growth. However, it is still unclear how the activity of DUSP8 is regulated, and little is known about the regulation of DUSP8 at the gene level. The goal of this study is to determine whether the DUSP8 gene is immediately transcribed upon MAPK activation in the cells. Here, we found that the expression of the DUSP8 gene was significantly increased after stimulation of cells for 30, 60, 90, and …

Biomechanics Of The Atherosclerotic Lipidome: (Un)Expected Statin Interactions And Membrane Remodelling, Ethan M. Fong

Pomona Senior Theses

Statins interact with lipid membranes in ways that shape their pharmacokinetics, off-target effects, and pleiotropic actions, yet these interactions' mechanical and biophysical consequences remain poorly understood. This thesis employs a combination of surface plasmon resonance (SPR), quartz crystal microbalance with dissipation monitoring (QCM-D), and rheological modelling to characterize how representative statins intercalate within biomimetic supported lipid bilayers (SLBs) of healthy and diseased composition. SPR reveals that lipophilic statins exhibit higher apparent affinities and slower dissociation kinetics, especially in cholesterol- and anionic lipid-rich membranes. QCM-D analyses demonstrate that statins alter membrane mass, dissipation, and interfacial stiffness in a statin- and membrane-dependent …

Temporal Dynamics Of Programmed Genome Rearrangement In Sea Lamprey Embryogenesis: A Deep Learning & Lightsheet Imaging Approach To Studying Early Developmental Transitions, Kasturi Rajandran

Theses and Dissertations--Biology

Programmed genome rearrangement (PGR) in the sea lamprey (Petromyzon marinus) leads to the elimination of ~0.5Gb (20%) of the germline genome during early embryogenesis, yet its timing relative to the maternal-to-zygotic transition (MZT) remains unclear. In this study, we imaged embryos cleared at 3-hour intervals (up to 72 hours post fertilization (hpf)) using high-resolution lightsheet fluorescence microscopy and a custom deep-learning image-analysis pipeline (~80% accuracy) to quantify nuclei and micronuclei counts. Micronuclei, which are the hallmarks of PGR first appear between 24 to 27hpf (vs ~36hpf previously reported) indicating PGR starts earlier than previously reported in the sea …

The Role Of Metabolic Gate Keepers In Cell Fate Decision Making, Brian Kelly

Theses and Dissertations--Biology

Maintaining cellular energy balance and redox stability is crucial to cell survival, with glutamine metabolism playing a central role. While extensively studied in cancer, where it supports biosynthesis and reduces oxidative stress to promote tumor growth, its function in non-cancerous contexts like tissue development and muscle regeneration remains less understood. A key aspect of stem cell biology is quiescence, a metabolically dormant state that preserves the stem cell pool, yet the mechanisms regulating this state are not fully clear. Here, we identify glutamine metabolism as a critical factor governing myoblast proliferation and quiescence through a metabolic program distinct from that …

Mir-27a-3p Regulates Intestinal Cell Proliferation And Differentiation Through Wnt/Β-Catenin Signalling, Chang Li, Yuning Zhou, Yinping Jiang, Zhijie Yin, Heidi L. Weiss, Qingding Wang, B. Mark Evers

Markey Cancer Center Faculty Publications

Intestinal stem cells differentiate into absorptive enterocytes, characterised by increased brush border enzymes such as intestinal alkaline phosphatase (IAP), making up the majority (95%) of the terminally differentiated cells in the villus. Loss of integrity of the intestinal epithelium plays a key role in inflammatory diseases and gastrointestinal infection. Here, we show that the intestinal microRNA (miR)-27a-3p is an important regulator of intestinal epithelial cell proliferation and enterocyte differentiation. Repression of endogenous miR-27a-3p leads to increased enterocyte differentiation and decreased intestinal epithelial cell proliferation in mouse and human small intestinal organoids. Mechanistically, miR-27a-3p regulates intestinal cell differentiation and proliferation at …

Using Abandoned Model Systems And Historical Literature To Teach Modern Concepts And Techniques In Cell Biology, Leocadia V. Paliulis, Gunar Fabig, Sandra Stein, Silke Tulok, Anja Nobst, Chukwuebuka William Okafornta, Thomas Kurth, Thomas Müller-Reichert

Faculty Journal Articles

The cell biology literature of the 19th and early-to-mid 20th centuries is full of the seminal works that were critical for the development of our current understanding of biology but were done using model systems that are no longer commonly used. We argue that these historical papers are ideal for the development of course-based research experiences, both because the background work is conceptually and technically straightforward, and because the study of the abandoned systems stopped prior to the availability of modern techniques. These abandoned systems offer outstanding opportunities for teaching modern light and electron microscopy techniques, thus providing students with …

Elucidating The Effects Of Environmental And Physiological Conditions On Stem Cell Regulation In Vivo, Nimmy John

Electronic Theses & Dissertations (2024 - present)

The Notch signaling pathway is a highly conserved intercellular signaling pathway that any dysregulation can lead to a variety of human diseases. These diseases are further exacerbated by various environmental, pathological and genetic conditions. Previous studies have shown that these conditions have been known to affect the Notch transcriptional response. However, the molecular mechanisms by which such conditions influence Notch signaling remained largely unknown. Moreover, most Notch studies have relied on in vitro systems and indirect reporters, which can miss the dynamic and contextual nature of Notch signaling. Here, we systematically analyzed the effects of these conditions with single molecule …

Accurate Body Weight Class Prediction From Mirna And Gene Expression In Blood And Saliva Samples, Kimberly Lettner

Master of Science in Forensic Science Directed Research Projects

miRNA interference on protein abundance related to glucose uptake and lipid production has been evaluated in biomedical research and linked to metabolic disorders like severe obesity. The direct regulation of protein abundance caused by miRNAs on a person’s metabolism can lead to an increased weight and overall size. Body size, measured by BMI, provides additional physical descriptions that can be combined with hair color, eye color, age, and skin pigment to aid investigations of unidentified remains or unknown suspects not found in a database. The purpose of this project was to evaluate the miRNA expression of target biomarkers in dried …

Phenotype Specific Nuclear Lamina Remodeling In Hipsc Derived Cardiomyocytes Bearing Tnnt2 Sarcomeric Variants, Isabella Leite Coscarella, Olalekan H. Usman, Lili Wang, Maicon Landim-Vieira, Lillian Wirstiuk, Amber N. Brown, Diego A. R. Zorio, Brian K. Washburn, Cynthia Vied, Bjorn C. Knollmann, Christopher Solís, Vitold E. Galkin, P. Bryant Chase, J. Travis Hinson, Jerome Irianto, Jose Renato Pinto

Department of Biomedical and Translational Sciences Faculty Publications

[Summary] Cardiomyocytes endure physical stress from the myocardium environment while generating their own mechanical strains. The force generated by sarcomeres is transmitted both longitudinally to adjacent sarcomeres and laterally to the cytoskeleton via intermediate filaments. This mechanical stimulus impacts other organelles, including the nucleus, thus playing a vital role in sensing and signaling nuclear adaptations. However, there is limited understanding of how changes in cardiac contractility affect nuclear mechanics. Here, we sought to investigate the effects of hyper- and hypo-contractility in nuclei of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) bearing TNNT2 pathogenic variants associated with hypertrophic (HCM) or dilated …

Leukocyte Infiltration Profiles At The Site Of Intradermal Injection Of Silikon-1000 In Scleroderma-Prone Ucd200/206 And Healthy White Leghorn Chickens, Katee L. Johnson, Jossie M. Santamaria, Chrysta N. Beck, Gisela F. Erf

Discovery, The Student Journal of Dale Bumpers College of Agricultural, Food and Life Sciences

Intradermal injections of silicone-based fillers for the face and body may cause chronic inflammation and fibrotic reactions in some individuals. Chickens from the UCD 200/206 White Leghorn (WL) line spontaneously develop a fibrotic autoimmune disease known as scleroderma/systemic sclerosis (SSc). Using the SSc-prone UCD and healthy WL chickens, a longitudinal study was conducted to examine the cellular inflammatory responses to intradermal (i.d.) injections of sterile SILIKON-1000. Specifically, the pulp (a skin derivative) of growing feathers (GFs) was i.d. injected with sterile SILIKON-1000 or phosphate-buffered saline (PBS) as injection control (8 and 3 birds/line, respectively; 10 µL/GF; 20 GFs/bird). Two GFs …

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 …

Penta Ef-Hand Protein Alg-2 Regulates Copii Activity At Eres In Response To Calcium Signaling, Jacob Ryan Lapka

Graduate Student Theses, Dissertations, & Professional Papers

Intracellular protein trafficking is critical for maintaining cellular homeostasis, relying on highly regulated vesicular transport pathways originating from the endoplasmic reticulum (ER). Central to this process is the COPII coat complex, which governs cargo export at ER exit sites (ERES) by selectively packaging secretory proteins into transport vesicles. Recent studies highlight the regulatory role of calcium (Ca²⁺) signaling at ERES, where the Ca²⁺-binding Penta EF-hand proteins ALG-2 and peflin modulate COPII coat dynamics and cargo sorting in a context-dependent manner. In Chapter 2, we show that knockdown of the Inositol 1,4,5-trisphosphate receptor-3 (IP3R-3) in normal rat …

Investigating The Role And Expression Of Aquaporin 10 Paralogs In Spiny Dogfish (Squalus Acanthias), Esosa Omoregie

College of Graduate Studies: Theses & Dissertations

Aquaporins (AQPs) are integral membrane proteins that facilitate the selective transport of water and small solutes across cell membranes, playing essential roles in maintaining osmotic balance in vertebrates. Among them, aquaglyceroporins such as AQP10 are capable of transporting water, glycerol, and urea, contributing to osmoregulatory and metabolic processes. This study investigated the expression, localization, and potential physiological roles of two AQP10 paralogs, AQP10C1 and AQP10C2, in the spiny dogfish (Squalus acanthias), a marine elasmobranch that maintains osmotic equilibrium through urea retention and ion regulation. Using RT-PCR, quantitative PCR, Western blotting and immunohistochemistry the study identified tissue-specific expression patterns of …

Repositioning Antimalarial Drugs As Anticancer Agents: Focus On Tafenoquine, Chris Barton

Funded Scholarship

Due to the expensive and lengthy process of drug design and approval, drug repurposing (or repositioning) has become another option for identifying preexisting molecules that may be used for alternative purposes. Recently, some antimalarial compounds have been shown to display efficacy against cancer cell proliferation. In this study, we provide evidence to suggest that multiple preexisting antimalarial drugs can reduce the viability of human cancer cells in culture. Furthermore, we provide the first evidence that one antimalarial, Tafenoquine (LD50 = 9.6 μM in HCT116 cells), is capable of decreasing viability with an efficacy comparable to Etoposide (LD50 = 15.2 μM …

Reversible Degradation Of Peptidoglycan By Lytic Transglycosylases, Aaron Devereaux

Theses and Dissertations (Comprehensive)

Antimicrobial resistance continues to be a burden on the global healthcare system with an estimated cost of billions of dollars and millions of deaths each year. Recently, there has been little to no development on new antibiotics to treat bacterial infection, and any that are developed become resisted to within a few years. Both Gram-positive and Gram-negative bacteria contain a mesh-like layer called peptidoglycan (PG) that surrounds their cells providing strength, cell shape, and protection from their environments. This layer is a polymer of N-acetylmuramic acid (MurNAc) and N-acetylglucosamine (GlcNAc) connected via a b-1,4-glycosidic bond, with each strand being cross-linked …

Inductions Of Long-Term Potentiation With Biomimetic Electromagnetic Fields In Primary Neurons, Cooper E. Kansala

Theses and Dissertations (Comprehensive)

Endogenous brain rhythms guide neural communication and plasticity, raising the question of whether weak, temporally structured electromagnetic fields (EMFs) that mimic these rhythms can modulate neuronal activity in a targeted, biomimetic manner. This thesis investigates whether patterned EMFs designed to reflect the temporal structure of hippocampal long-term potentiation (LTP) are more effective at inducing neural plasticity than conventional sinusoidal fields or no stimulation at all. Cortical neurons cultured from postnatal rats were exposed to patterned EMFs for 30 minutes and assessed across three distinct experimental domains. In Chapter 2, microelectrode array (MEA) recordings revealed that the LTP-patterned field significantly increased …

Unveiling The Cell Composition Of The Olfactory Migratory Mass: Perspectives On Terminal Nerve Formation, Olfactory Development, And Migration Of The Gnrh-1 Neurons, Enrico Amato Jr.

Electronic Theses & Dissertations (2024 - present)

Puberty is a postnatal developmental process required to initiate key sexual maturation events that are necessary for the propagation of species. Signals to initiate these events first begin with the Gonadotropin releasing hormone-1 (GnRH-1) neurons within the hypothalamus. The hormone GnRH-1 released by these neurons is crucial for puberty, fertility and reproductive processes by establishing the hypothalamic-pituitary-gonadal (HPG) axis, regulating release of sex hormones (Progesterone, Estrogen, Testosterone). Conditions related to inability of the GnRH-1 neurons to correctly release GnRH-1 can lead to aberrant or delayed puberty, a condition known as hypogonadotropic hypogonadism (HH). Interestingly, some patients with the hormonal disorder …

Characterization Of The Erv41-Erv46 Complex As A Retrograde Receptor For Misfolded Secretory Proteins, John Andrew Fuesler

Dartmouth College Ph.D Dissertations

The Endoplasmic Reticulum (ER), the site of secretory protein biosynthesis

provides a favorable environment to promote polypeptide folding, protein

oligomerization and export. Although the ER contains many chaperones and other

factors that assist in protein folding, this process is error prone. Eukaryotes have

evolved protein quality control checkpoints to maintain homeostasis in the secretory

pathway, however these processes are imperfect and may result in proteotoxicity

when toxic levels or aggregates of proteins arise. Mutations in proteins involved in

trafficking in the early secretory pathway are closely associated with disease states.

Therefore, it is of great interest to further understand how …