Cell Biology Commons^™

Abl1/2 And Ddr1 Cooperate To Stabilize Braf/Craf To Drive Erk1/2 Reactivation And Promote Mek Inhibitor Resistance In Nras-Mutant Melanomas, Anastasia Lyon

Theses and Dissertations--Pharmacology and Nutritional Sciences

This study addresses the escalating incidence of NRAS-mutant melanomas, a type of skin cancer lacking FDA-approved targeted therapies. Despite ongoing research targeting the RAF/MEK/ERK pathway, existing drugs fail to enhance progression-free survival due to acquired resistance. This project identifies a novel role for ABL1/2 and DDR1 kinases in driving drug resistance and proliferation of NRAS-mutant melanoma cells. ABL1/2 and DDR1 cooperate to promote RAF homodimerization and protein stability in order to reactivate MEK/ERK signaling to drive MEK1/2 inhibitor (MEKi) resistance and promote survival of resistant cells. By targeting ABL1/2 and DDR1 with nilotinib, a FDA-approved anti-leukemic inhibitor, we …

Role Of Autophagy-Related Genes In Lipid Transport For Efficient Replication Of Tombusviruses, Yuanrong Kang

Theses and Dissertations--Plant Pathology

Tombusviruses are positive-strand RNA viruses, which utilize numerous co-opted host factors and massive de-novo synthesized membrane resources to modify host membranes and form large viral replication organelles (VROs). Among plenty of host cellular processes, autophagy emerges as a potential membrane resource for VROs formation due to its ability to de-novo generate the double membrane structures, known as autophagosomes. Besides, as an important host defense pathway, autophagy is also a target for tombusviruses to prevent its antiviral activities. In this study, I identify the role of key autophagy related genes, Atg11, Atg8, and Atg2, which are involved in autophagosome formation, and …

Synthesis Of Long Oligodeoxynucleotides, Yipeng Yin

Dissertations, Master's Theses and Master's Reports

Synthetic long oligodeoxynucleotides (ODNs) have found wide applications in diverse fields such as chemical biology, synthetic biology, and genes and genomes synthesis. Those applications leading to a significant demand for their production. However, traditional methods for purifying synthetic ODNs present notable drawbacks, particularly their inability to purify long ODNs, rendering long ODN synthesis challenging. To address these issues, chemical synthesis techniques for long ODNs coupled with non-chromatographic purification methods have been developed. This technology makes the purification of long synthetic ODNs feasible and offers a viable pathway for producing genes and genomes with extensive repeats or stable secondary structures, which …

Cyp6g2 Is The Major P450 Epoxidase Responsible For Juvenile Hormone Biosynthesis In Drosophila Melanogaster, Qiangqiang Jia, Liu Yang, Jiamin Wen, Suning Liu, Di Wen, Wei Luo, Weihua Wang, Subba R. Palli, Li Sheng

Entomology Faculty Publications

Background Juvenile hormones (JH) play crucial role in regulating development and reproduction in insects. The most common form of JH is JH III, derived from MF through epoxidation by CYP15 enzymes. However, in the higher dipterans, such as the fruitfly, Drosophila melanogaster, a bis-epoxide form of JHB3, accounted most of the JH detected. Moreover, these higher dipterans have lost the CYP15 gene from their genomes. As a result, the identity of the P450 epoxidase in the JH biosynthesis pathway in higher dipterans remains unknown.

Results In this study, we show that Cyp6g2 serves as the major JH epoxidase responsible for …

The Mechanoreceptor Piezo Is Required For Spermatogenesis In Bombyx Mori, Zhongjie Zhang, Xiaojing Liu, Bo Hu, Kai Chen, Ye Yu, Chenxin Sun, Dalin Zhu, Hua Bai, Subba Reddy Palli, Anjiang Tan

Entomology Faculty Publications

Background The animal sperm shows high diversity in morphology, components, and motility. In the lepidopteran model insect, the silkworm Bombyx mori, two types of sperm, including nucleate fertile eupyrene sperm and anucleate unfertile apyrene sperm, are generated. Apyrene sperm assists fertilization by facilitating the migration of eupyrene spermatozoa from the bursa copulatrix to the spermatheca. During spermatogenesis, eupyrene sperm bundles extrude the cytoplasm by peristaltic squeezing, while the nuclei of the apyrene sperm bundles are discarded with the same process, forming matured sperm.

Results In this study, we describe that a mechanoreceptor BmPiezo, the sole Piezo ortholog in B. mori, …

Prenatal Androgen Exposure Reduces Ovarian Function, Marlee Weets

All Master's Theses

Polycystic ovary syndrome (PCOS) is the most common reproductive and endocrine disorder, being the leading cause of infertility for females of reproductive age. The etiology of PCOS is not fully known, although it is hypothesized that there is a genetic, epigenetic, and environmental component to the disease. One of the environmental influences that can cause an abnormal reproductive phenotype similar to PCOS is prenatal exposure to excess androgens (male sex hormones). Previous studies have shown that prenatal exposure to androgens in mice can cause a PCOS-like ovarian phenotype similar to people with PCOS. To examine how prenatal androgen exposure causes …

Sialylation As A Mechanism For Preferential Ligand Binding In Cfs1r, Eric J. Beaulaurier

EWU Masters Thesis Collection

Macrophages are immune cells that help provide the first line of defense against a wide range of internal and external insults and create the bridge between innate and adaptive immune responses. When macrophage homeostasis is disrupted, disease states occur. Associated disease states include rheumatoid arthritis, Alzheimer’s disease, and multiple sclerosis. The survival and proliferation of macrophages is largely controlled by signaling through colony stimulating factor 1 receptor (CSF1R). Notably, this receptor can be activated by two non-homologous ligands, colony stimulating factor 1 (CSF1) and interleukin- 34 (IL-34). These two ligands are differentially required for macrophage homeostasis across body systems and …

Examining The Effects Of Artemisia Annua On Neuro2a Cells, Wesley Lim

Honors Undergraduate Theses

Artemisia annua L. is a well-known medicinal herb used in Traditional Chinese Medicine for many centuries and contains artemisinin, which exhibits antimalarial properties [1] and is a potential treatment for SARS-CoV-2 [2]. However, the neurological effect of A. annua and its compounds are poorly understood. We hypothesize that A. annua extracts and artemisinin will provide protection against oxidative stress in mouse neuronal Neuro2A cells. Superoxide dismutase 1 (SOD1) is an anti-oxidant enzyme that protects against oxidative damage [3]. Growth Arrest and DNA Damage-inducible 45 alpha (Gadd45a) is involved in DNA repair and is a common biomarker for DNA damage[4]. SOD1 …

Identification Of Cellulose Synthase Structural Features Involved In Cellulose Synthesis Complex Formation, Jamie Lamkin

Open Access Dissertations

Cellulose is a microfibrillar polysaccharide component of plant cell walls and consists of bundles of β-1,4-linked glucan chains. In addition to being important for plant cell walls, cellulose is also used by humans for a variety of purposes such as biofuels and building materials. Cellulose is produced by the integral plasma membrane enzyme Cellulose Synthase (CESA) and multiple CESA proteins can combine to form a six-lobed rosette structure called a Cellulose Synthesis Complex (CSC). In seed plants CSCs appear to be hetero-oligomeric, comprising three different CESA isoforms. However some non-seed plants, such as the bryophyte Physcomitrium patens, can form …

The Carboxy Terminus Causes Interfacial Assembly Of Oleate Hydratase On A Membrane Bilayer, Christopher D. Radka, Christy R. Grace, Hale S. Hasdemir, Yupeng Li, Carlos C. Rodriguez, Patrick Rodrigues, Michael L. Oldham, M. Zuhaib Qayyum, Aaron Pitre, William J. Maccain, Ravi C. Kalathur, Emad Tajkhorshid, Charles O. Rock

Markey Cancer Center Faculty Publications

The soluble flavoprotein oleate hydratase (OhyA) hydrates the 9-cis double bond of unsaturated fatty acids. OhyA sub- strates are embedded in membrane bilayers; OhyA must remove the fatty acid from the bilayer and enclose it in the active site. Here, we show that the positively charged helix- turn-helix motif in the carboxy terminus (CTD) is responsible for interacting with the negatively charged phosphatidylgly- cerol (PG) bilayer. Super-resolution microscopy of Staphylo- coccus aureus cells expressing green fluorescent protein fused to OhyA or the CTD sequence shows subcellular localization along the cellular boundary, indicating OhyA is membrane- associated and the CTD sequence …

Elevated Free Cholesterol Levels Due To Impaired Reverse Cholesterol Transport Are A Risk Factor For Polymicrobial Sepsis In Mice, Qian Wang, Ling Guo, Dan Hao, Misa Ito, Chieko Mineo, Philip W. Shaul, Xiang-An Li

Markey Cancer Center Faculty Publications

Dysregulated lipid metabolism is commonly observed in septic patients, but how it contributes to sepsis remains largely unknown. Reverse cholesterol transport (RCT) is crucial for regulating cholesterol metabolism in circulation. During RCT, high-density lipoprotein collects cholesterol from peripheral tissues and transports it to the liver’s scavenger receptor BI (SR- BI), where SR-BI mediates the uptake of cholesteryl esters (CEs) from high-density lipoprotein for excretion via bile. In this study, we utilized AlbCreSR-BIfl/fl mice, a model with impaired RCT, to investigate the impact of RCT on sepsis. We found that AlbCreSR-BIfl/fl mice were significantly more susceptible to cecal ligation and puncture …

Nudcl2 Is Required For Cytokinesis By Stabilizing Rcc2 With Hsp90 At The Midbody, Xiaoyang Xu, Yuliang Huang, Feng Yang, Xiaoxia Sun, Rijin Lin, Jiaxing Feng, Mingyang Yang, Jiaqi Shao, Xiaoqi Liu, Tianhua Zhou, Shanshan Xie, Yuehong Yang

Markey Cancer Center Faculty Publications

Cytokinesis is required for faithful division of cytoplasmic components and duplicated nuclei into two daughter cells. Midbody, a protein-dense organelle that forms at the intercellular bridge, is indispensable for success- ful cytokinesis. However, the regulatory mechanism of cytokinesis at the midbody still remains elusive. Here, we unveil a critical role for NudC-like protein 2 (NudCL2), a co-chaperone of heat shock protein 90 (Hsp90), in cytokinesis regulation by stabilizing regulator of chromosome condensation 2 (RCC2) at the midbody in mam- malian cells. NudCL2 localizes at the midbody, and its downregulation results in cytokinesis failure, multinu- cleation, and midbody disorganization. Using iTRAQ-based …

Pai-1 As A Critical Factor In The Resolution Of Sepsis And Acute Kidney Injury In Old Age, Maria E. C. Bruno, Sujata Mukherjee, Jamie L. Sturgill, Virgilius Cornea, Peng Yeh, Gregory S. Hawk, Hiroshi Saito, Marlene E. Starr

Markey Cancer Center Faculty Publications

Elevated plasma levels of plasminogen activator inhibitor type 1 (PAI-1) are documented in patients with sepsis and levels positively correlate with disease severity and mortality. Our prior work demonstrated that PAI-1 in plasma is positively associated with acute kidney injury (AKI) in septic patients and mice. The objective of this study was to determine if PAI-1 is causally related to AKI and worse sepsis outcomes using a clinically-relevant and age-appropriate murine model of sepsis. Sepsis was induced by cecal slurry (CS)-injection to wild-type (WT, C57BL/6) and PAI-1 knockout (KO) mice at young (5–9 months) and old (18–22 months) age. Survival …

Structure, Dynamics, And Redox Reactivity Of An All-Purpose Flavodoxin, Sharique Khan, Ahmadullah Ansari, Monica Brachi, Debarati Das, Wassim El Housseini, Shelley Minteer, Anne-Francis Miller

Markey Cancer Center Faculty Publications

The flavodoxin of Rhodopseudomonas palustris CGA009 (Rp9Fld) supplies highly reducing equivalents to crucial en- zymes such as hydrogenase, especially when the organism is iron-restricted. By acquiring those electrons from photodriven electron flow via the bifurcating electron transfer flavoprotein, Rp9Fld provides solar power to vital metabolic processes. To understand Rp9Fld’s ability to work with diverse partners, we solved its crystal structure. We observed the canonical fla- vodoxin (Fld) fold and features common to other long-chain Flds but not all the surface loops thought to recognize part- ner proteins. Moreover, some of the loops display alternative structures and dynamics. To advance studies …

Non-Transcriptional Irf7 Interacts With Nf-Κb To Inhibit Viral Inflammation, Shumin Fan, Sonam Popli, Sukanya Chakravarty, Ritu Chakravarty, Saurabh Chattopadhyay

Markey Cancer Center Faculty Publications

Interferon (IFN) regulatory factors (IRF) are key transcrip- tion factors in cellular antiviral responses. IRF7, a virus- inducible IRF, expressed primarily in myeloid cells, is required for transcriptional induction of interferon α and antiviral genes. IRF7 is activated by virus-induced phosphory- lation in the cytoplasm, leading to its translocation to the nu- cleus for transcriptional activity. Here, we revealed a nontranscriptional activity of IRF7 contributing to its antiviral functions. IRF7 interacted with the pro-inflammatory tran- scription factor NF-κB-p65 and inhibited the induction of in- flammatory target genes. Using knockdown, knockout, and overexpression strategies, we demonstrated that IRF7 inhibited NF-κB–dependent inflammatory …

Foxs1 Is Increased In Liver Fibrosis And Regulates Tgfβ Responsiveness And Proliferation Pathways In Human Hepatic Stellate Cells, Evelyn A. Bates, Zachary A. Kipp, Wang-Hsin Lee, Genesee J. Martinez, Lauren Weaver, Kathryn N. Becker, Sally Pauss, Justin F. Creeden, Garrett B. Anspach, Robert N. Helsley, Mei Xu, Maria E. C. Bruno, Marlene E. Starr, Terry D. Hinds Jr.

Markey Cancer Center Faculty Publications

Liver fibrosis commences with liver injury stimulating transforming growth factor beta (TGFβ) activation of hepatic stellate cells (HSCs), causing scarring and irreversible damage. TGFβ induces expression of the transcription factor Forkhead box S1 (FOXS1) in hepatocytes and may have a role in the pathogenesis of hepatocellular carcinoma (HCC). To date, no studies have determined how it affects HSCs. We analyzed human livers with cirrhosis, HCC, and a murine fibrosis model and found that FOXS1 expression is significantly higher in fibrotic livers but not in HCC. Next, we treated human LX2 HSC cells with TGFβ to activate fibrotic pathways, and FOXS1 …

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 integ- rity of the intestinal epithelium plays a key role in inflammatory diseases and gastro- intestinal infection. Here, we show that the intestinal microRNA (miR)-27a-3p is an important regulator of intestinal epithelial cell proliferation and enterocyte differenti- ation. Repression of endogenous miR-27a-3p leads to increased enterocyte differen- tiation and decreased intestinal epithelial cell proliferation in mouse and human small intestinal organoids. Mechanistically, miR-27a-3p regulates intestinal cell …

Kif3a Tail Domain Phosphorylation Is Not Required For Ciliogenesis In Mouse Embryonic Fibroblasts, Ayoola Fasawe, Jessica M. Adams, Martin Engelke

Faculty Publications – Biological Sciences

Primary cilia are essential signaling organelles that protrude from most cells in the body. Heterodimeric kinesin-2 (KIF3A/KIF3B/KAP3) powers several intracellular transport processes, including intraflagellar transport (IFT), essential for ciliogenesis. A long-standing question is how a motor protein is differentially regulated for specific cargos. Since phosphorylation of the KIF3A tail domain was suggested to regulate the activity of kinesin-2 for ciliogenesis, similarly as for the cytosolic cargo N-Cadherin, we set out to map the phosphosites involved in this regulation. Using well-characterized Kif3a−/−; Kif3b−/− mouse embryonic fibroblasts, we performed ciliogenesis rescue assays with a library of phosphomimetic mutants comprising all …

Investigating Division Quest: A Text-Based Adventure Narrative Game For Overcoming Difficulties Of Mitosis Learning, Amanda G. Conner

College of Graduate Studies: Theses & Dissertations

Mitosis learning is a source of struggle for many introductory biology students. Much of this difficulty stems from an overwhelming amount of terminology and moving pieces as well as the abstract nature of cellular processes. Game-based learning (GBL) has been used in other contexts to reduce cognitive load and provide relatable experiences upon which students can construct their mental models. However, commercial GBL is often expensive and difficult to align with individual instructor teaching preferences and learning objectives. In this study, we use a mixed methods approach to explore the use of a GBL tool made in Twine to overcome …

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 …