Cell Biology Commons^™

Bioethics In The Work Of Ernest Everett Just: + Missing - Some 400 Pages, Theodore Walker

Perkins Faculty Research and Special Events

Biology + ethics = bioethics. Here we see that Howard University biologist Ernest Everett Just (born 1883, died 1941) connected biology to ethics.

According to Just, various forms of specific biology (including especially cell biology) plus “general biology” are necessary for explaining adequately the origin of ethical behaviors. Social ethical behaviors, especially mutual aid and cooperative interactions with others and the environment, are essential to evolutionary advances among living creatures, ranging from humans to cells. Accordingly, theory of ethics (moral theory) should have roots in biology.

Also, Just wrote an unpublished book-length manuscript—“some 400 typed pages” (Just 1940)—on seeking the …

Evolutionary Adaptations Of Biofilms Infecting Cystic Fibrosis Lungs Promote Mechanical Toughness By Adjusting Polysaccharide Production, Kristin Kovach, Megan Davis-Fields, Yasuhiko Irie, Kanishk Jain, Shashvat Doorwar, Katherine Vuong, Numa Dhamani, Kishore Mohanty, Ahmed Touhami, Vernita D. Gordon

Biology Faculty Publications

Biofilms are communities of microbes embedded in a matrix of extracellular polymeric substances, largely polysaccharides. Multiple types of extracellular polymeric substances can be produced by a single bacterial strain. The distinct polymer components of biofilms are known to provide chemical protection, but little is known about how distinct extracellular polysaccharides may also protect biofilms against mechanical stresses such as shear or phagocytic engulfment. Decades-long infections of Pseudomonas. aeruginosa biofilms in the lungs of cystic fibrosis patients are natural models for studies of biofilm fitness under pressure from antibiotics and the immune system. In cystic fibrosis infections, production of the extracellular …

Phlpp Regulates Hexokinase 2-Dependent Glucose Metabolism In Colon Cancer Cells, Xiaopeng Xiong, Yang-An Wen, Mihail I. Mitov, Mary C. Oaks, Shigeki Miyamoto, Tianyan Gao

Markey Cancer Center Faculty Publications

Increased glucose metabolism is considered as one of the most important metabolic alterations adapted by cancer cells in order to generate energy as well as high levels of glycolytic intermediates to support rapid proliferation. PH domain leucine-rich repeat protein phosphatase (PHLPP) belongs to a novel family of Ser/Thr protein phosphatases that function as tumor suppressors in various types of human cancer. Here we determined the role of PHLPP in regulating glucose metabolism in colon cancer cells. Knockdown of PHLPP increased the rate of glucose consumption and lactate production, whereas overexpression of PHLPP had the opposite effect. Bioenergetic analysis using Seahorse …

Crispr-Cas9 Mediated Nox4 Knockout Inhibits Cell Proliferation And Invasion In Hela Cells, Naser Jafari, Hyunju Kim, Rackhyun Park, Liqing Li, Minsu Jang, Andrew J. Morris, Junsoo Park, Cai Huang

Markey Cancer Center Faculty Publications

Increased expression of NOX4 protein is associated with cancer progression and metastasis but the role of NOX4 in cell proliferation and invasion is not fully understood. We generated NOX4 knockout HeLa cell lines using the CRISPR-Cas9 gene editing system to explore the cellular functions of NOX4. After transfection of CRISPR-Cas9 construct, we performed T7 endonuclease 1 assays and DNA sequencing to generate and identify insertion and deletion of the NOX4 locus. We confirmed the knockout of NOX4 by Western blotting. NOX4 knockout cell lines showed reduced cell proliferation with an increase of sub-G1 cell population and the decrease of S/G2/M …

Effects Of Pentachlorophenol And Dichlorodiphenyltrichloroethane On Secretion Of Interferon Gamma (Ifnγ) And Tumor Necrosis Factor Alpha (Tnfα) From Human Immune Cells, Reda Massawe, Leon Drabo, Margaret Whalen

Chemistry Faculty Research

Pentachlorophenol (PCP) and dichlorodiphenyltrichloroethane (DDT) are pesticides that have been widely used and significantly contaminate the environment. Both are found in human blood and have been shown to alter the lytic and binding function of human natural killer (NK) cells. Interferon gamma (IFNγ) and tumor necrosis factor alpha (TNFα) are pro-inflammatory cytokines, which regulate immune responsiveness to pathogens and tumors. Their levels require very tight control to prevent loss of immune competence or excessive inflammation. Here, we examined the capacity of PCP and DDT to alter the secretion of these critical pro-inflammatory cytokines from increasingly reconstituted (more complex) preparations of …

A Cascade Of Multiple Proteins And Lipids Catalyzes Membrane Fusion, William Wickner, Josep Rizo

Dartmouth Scholarship

Recent studies suggest revisions to the SNARE paradigm of membrane fusion. Membrane tethers and/or SNAREs recruit proteins of the Sec 1/Munc18 family to catalyze SNARE assembly into trans-complexes. SNARE-domain zippering draws the bilayers into immediate apposition and provides a platform to position fusion triggers such as Sec 17/α-SNAP and/or synaptotagmin, which insert their apolar "wedge" domains into the bilayers, initiating the lipid rearrangements of fusion.

Chloroquine-Inducible Par-4 Secretion Is Essential For Tumor Cell Apoptosis And Inhibition Of Metastasis, Ravshan Burikhanov, Nikhil Hebbar, Sunil K. Noothi, Nidhi Shukla, James Sledziona, Nathália Araujo, Meghana Kudrimoti, Qing Jun Wang, David S. Watt, Danny R. Welch, Jodi Maranchie, Akihiro Harada, Vivek M. Rangnekar

Radiation Medicine Faculty Publications

The induction of tumor suppressor proteins capable of cancer cell apoptosis represents an attractive option for the re-purposing of existing drugs. We report that the anti-malarial drug, chloroquine (CQ), is a robust inducer of Par-4 secretion from normal cells in mice and cancer patients in a clinical trial. CQ-inducible Par-4 secretion triggers paracrine apoptosis of cancer cells and also inhibits metastatic tumor growth. CQ induces Par-4 secretion via the classical secretory pathway that requires the activation of p53. Mechanistically, p53 directly induces Rab8b, a GTPase essential for vesicle transport of Par-4 to the plasma membrane prior to secretion. Our findings …

An Amphipathic Trans-Acting Phosphorothioate Rna Element Delivers An Uncharged Phosphorodiamidate Morpholino Sequence In Mdx Mouse Myotube, H. Jain, J. Boehler, D. Verthelyi, Kanneboyina Nagaraju, S. Beaucage

Genomics and Precision Medicine Faculty Publications

An efficient method for the delivery of uncharged polyA-tailed phosphorodiamidate morpholino sequences (PMO) in mammalian cells consists of employing a synthetic 8-mer amphipathic trans-acting poly-2′-O-methyluridylic thiophosphate triester element (2′-OMeUtaPS) as a transfection reagent. Unlike the dTtaPS DNA-based element, this RNA element is potent at delivering polyA-tailed PMO sequences to HeLa pLuc 705 cells or to myotube muscle cells. However, much like dTtaPS, the 2′-OMeUtaPS-mediated internalization of PMO sequences occurs through an energy-dependent mechanism; macropinocytosis appears to be the predominant endocytic pathway used for cellular uptake. The transfected PMO sequences induce alternate splicing of either the pre-mRNA encoding luciferase in HeLa …

Lysosomal Storage Diseases, Carlos Ferreira, William Gahl

Pediatrics Faculty Publications

Lysosomes are cytoplasmic organelles that contain a variety of different hydrolases. A genetic deficiency in the enzymatic activity of one of these hydrolases will lead to the accumulation of the material meant for lysosomal degradation. Examples include glycogen in the case of Pompe disease, glycosaminoglycans in the case of the mucopolysaccharidoses, glycoproteins in the cases of the oligosaccharidoses, and sphingolipids in the cases of Niemann-Pick disease types A and B, Gaucher disease, Tay-Sachs disease, Krabbe disease, and metachromatic leukodystrophy. Sometimes, the lysosomal storage can be caused not by the enzymatic deficiency of one of the hydrolases, but by the deficiency …

Dense Core Vesicle Heterogeneity In Anterior Pituitary Cells, Kelly Sinak

Electronic Theses and Dissertations

Peptides, which are packaged in dense core vesicles, are an integral part of the function of the endocrine and neurological systems. The dense core vesicles function as an efficient form of peptide storage prior to regulated exocytosis. Two different dense core specific transmembrane proteins traffic different when comparted to retained prolactin cores, offering evidence of heterogeneity of vesicles within a single cell. By comparing synaptotagmin 1 and 7 distribution in male rat and lactating female lactotrophs, a distinct pattern emerges. Cells that retain prolactin cores after exocytosis correspond with those that contain synaptotagmin 1. This finding is a reversal for …

Commonly Used H1 And H2 Histamine Receptor (Hr) Blockers Decrease Cholangiocarcinoma Xenograft Tumor Growth, Angiogenesis And Emt, Lindsey Kennedy, Laura Hargrove, Jennifer Demieville, Walker Karstens, Steven Smith, Heather Francis

Hepatobiliary Cancers: Pathobiology and Translational Advances

No abstract provided.

Development Of Cellular Assays To Monitor Enzymatic And Biological Activity Of Cd73: A Key Modulator Of Anti-Tumor Immune Response, Alexandra Fanuka

Graduate School of Biomedical Sciences Theses and Dissertations

Ecto-5’-nucleotidase, known as CD73, is an extracellular enzyme that converts adenosine monophosphate (AMP) to adenosine and has recently been identified as a potential drug target for cancer immunotherapy. Its immunosuppressive effects, mediated by the activity of adenosine, are associated with higher rates of tumor invasion and metastasis, as well as poorer prognoses overall in many cancer types. CD73 is often co-expressed with ectonucleoside triphosphate diphosphohydrolase-1 (CD39), which catalyzes the conversion of adenosine triphosphate (ATP) to adenosine diphosphate (ADP), and ADP to AMP on the surface of tumor cells. Dual expression further propagates immunosuppressive effects of adenosine in the tumor microenvironment. …

The Response Of Satellite Glial Cells To P2x7 Receptor Activation, Christina D. Kursewicz

Honors Undergraduate Theses

Satellite glial cells (SGCs) surround the cell bodies of neurons of the peripheral nervous system, including those of the sensory ganglia. Their close apposition to the neuronal soma allows for bi-directional communication between neurons and SGCs, which are thought to regulate neuronal activity. After nerve injury, SGCs in the dorsal root ganglia contribute to neuropathic pain. Although the mechanisms are not fully understood, SGCs show increased coupling via gap junctions, and communicate with the neuron via bi-directional purinergic signaling after nerve injury. The increased coupling between SGCs and neurons may have implications for chronic pain following peripheral nerve injury. In …

Alpha-Synuclein: Insight Into The Hallmark Of Parkinson's Disease As A Target For Quantitative Molecular Diagnostics And Therapeutics, Baggio A. Evangelista

Honors Undergraduate Theses

Parkinson’s disease (PD) is the second-most common neurodegenerative disease after Alzheimer’s disease. With 500,000 individuals currently living with Parkinson’s and nearly 60,000 new cases diagnosed each year, this disease causes significant financial burden on the healthcare system - amassing to annual expenditures totaling 200 billion dollars; predicted to increase through 2050. The disease phenotype is characterized by a combination of a resting tremor, bradykinesia, muscular rigidity, and depression due to dopaminergic neuronal death in the midbrain. The cause of the neurotoxicity has been largely discussed, with strong evidence suggesting that the protein, alpha-Synuclein, is a key factor. Under native conditions, …

A Family Of Genus-Specific Rnas In Tandem With Dna-Binding Proteins Control Expression Of The Bada Major Virulence Factor Gene In Bartonella Henselae, Nhan Tu, Ronan K. Carroll, Andy Weiss, Lindsey N. Shaw, Gael Nicolas, Sarah Thomas, Amorce Lima, Udoka Okaro, Burt Anderson

Molecular Biosciences Faculty Publications

Bartonella henselae is a gram-negative zoonotic bacterium that causes infections in humans including endocarditis and bacillary angiomatosis. B. henselae has been shown to grow as large aggregates and form biofilms in vitro. The aggregative growth and the angiogenic host response requires the trimeric autotransporter adhesin BadA. We examined the transcriptome of the Houston-1 strain of B. henselae using RNA-seq revealing nine novel, highly-expressed intergenic transcripts (Bartonella regulatory transcript, Brt1-9). The Brt family of RNAs is unique to the genus Bartonella and ranges from 194 to 203 nucleotides with high homology and stable predicted secondary structures. Immediately downstream of each …

Towards The Complete Proteinaceous Regulome Of Acinetobacter Baumannii, Leila G. Casella, Andy Weiss, Ernesto Pérez-Rueda, J Antonio Ibarra, Lindsey N. Shaw

Molecular Biosciences Faculty Publications

The emergence of Acinetobacter baumannii strains, with broad multidrug-resistance phenotypes and novel virulence factors unique to hypervirulent strains, presents a major threat to human health worldwide. Although a number of studies have described virulence-affecting entities for this organism, very few have identified regulatory elements controlling their expression. Previously, our group has documented the global identification and curation of regulatory RNAs in A. baumannii. As such, in the present study, we detail an extension of this work, the performance of an extensive bioinformatic analysis to identify regulatory proteins in the recently annotated genome of the highly virulent AB5075 strain. In so …

Genetic Analysis Of Serf Gene Function In Drosophila Melanogaster And Its Contribution To A Fly Model Of Spinal Muscular Atrophy, Swagata Ghosh

Theses and Dissertations--Biology

The Serf gene is evolutionarily highly conserved but its biological function is not known in any organism. In human, SERF1/H4F5 was first identified as a modifier of the disease Spinal Muscular Atrophy (SMA). SMA is caused by mutations in the Survival Motor Neuron 1(SMN1) gene leading to diminished levels of the Smn protein. More than 90% of patients with the most severe form of SMA have deletions that remove SERF1 as well as mutaions within SMN1. Hence, loss of Serf activity is hypothesized to exacerbate SMA disease progression. The primary motivation of this thesis was to test …

Nanosecond Pulsed Electric Field Induced Changes In Cell Surface Charge Density, Diganta Dutta, Xavier-Lewis Palmer, Anthony Asmar, Michael Stacey, Shizhi Qian

Bioelectrics Publications

This study reports that the surface charge density changes in Jurkat cells with the application of single 60 nanosecond pulse electric fields, using atomic force microscopy. Using an atomic force microscope tip and Jurkat cells on silica in a 0.01 M KCl ionic concentration, we were able to measure the interfacial forces, while also predicting surface charge densities of both Jurkat cell and silica surfaces. The most important finding is that the pulsing conditions varyingly reduced the cells' surface charge density. This offers a novel way in which to examine cellular effects of pulsed electric fields that may lead to …

Differential Activity And Content Of High-Affinity Glutamate Transporters, Content Of Their Regulatory Proteins, And Capacity For Glutamine And Glutathione Synthesis In Tissues Of Finished Versus Growing Steers, Jing Huang

Theses and Dissertations--Animal and Food Sciences

Improvement of feeding regimens for production animals has been hindered by a lack of fundamental knowledge about how the capacity to regulate nutrient absorption across cell membranes affects the function of nutrient metabolizing enzymes. The objective is to determine if the activities and protein content of system X^-_AG glutamate transporter, its regulatory protein (GTRAP3-18 and ARL6IP1), glutamine synthetase (GS) and glutathione (GSH) content, changes in liver (Experiment 1), longissimus dorsi (LM) and subcutaneous adipose tissue (SF) (Experiment 2) as beef steers transitioned from predominantly-lean (growing) to -lipid (finished) tissue accretion phases. In liver (Experiment 1), system X^{- …}

The Role Of N-Myc Downstream Regulated Gene 1 In Breast Cancer Lipid Metabolism, Christopher James Sevinsky

Legacy Theses & Dissertations (2009 - 2024)

Altered carbohydrate and lipid metabolism are increasingly well characterized hallmarks of aggressive breast cancers. While aerobic glycolysis, or “the Warburg effect”, is a well-established metabolic adaptation exploited by tumor cells, the understanding of unique aspects of cancer lipid metabolism lags behind. This is especially true regarding the coordination of complex lipid synthesis and trafficking pathways, which remains poorly understood. N-Myc Downstream Regulated Gene1 (NDRG1) is overexpressed in many solid tumors, but its function is unclear. The importance of NDRG1 is best exemplified by the effect of null mutations on human physiology: inactivating mutations give rise to the severe autosomal recessive …