Life Sciences Commons^™

Partitioning The Fitness Components Of Rna Populations Evolving In Vitro, Carolina Diaz Arenas, Niles Lehman

Chemistry Faculty Publications and Presentations

All individuals in an evolving population compete for resources, and their performance is measured by a fitness metric. The performance of the individuals is relative to their abilities and to the biotic surroundings – the conditions under which they are competing – and involves many components. Molecules evolving in a test tube can also face complex environments and dynamics, and their fitnessmeasurements should reflect the complexity of various contributing factors as well. Here, the fitnesses of a set of ligase ribozymes evolved by the continuous in vitroevolution system were measured. During these evolution cycles there are three different catalytic …

Secretion Of Interferon Gamma From Human Immune Cells Is Altered By Exposure To Tributyltin And Dibutyltin, Shanieek Lawrence, Jacqueline Reid, Margaret Whalen

Chemistry Faculty Research

Tributyltin (TBT) and dibutyltin (DBT) are widespread environmental contaminants found in food, beverages, and human blood samples. Both of these butyltins (BTs) interfere with the ability of human natural killer (NK) cells to lyse target cells and alter secretion of the pro-inflammatory cytokine tumor necrosis factor alpha (TNFα) from human immune cells in vitro. The capacity of BTs to interfere with secretion of other pro-inflammatory cytokines has not been examined. Interferon gamma (IFNγ) is a modulator of adaptive and innate immune responses, playing an important role in overall immune competence. This study shows that both TBT and DBT alter secretion …

Stellaris Fish Workshop Gadph And Dapi Z-Series, George Mcnamara

George McNamara

Stellaris FISH workshop GADPH and DAPI Z-series at MD Anderson Cancer Center, Houston, TX.

The zip file contains raw and GPU deconvolved image data from a workshop Biosearch Technologies conducted for MDACC researchers in December 2013. Image data was acquired on a Leica DMI6000 microscope with Lumencor SOLA light engine, DAPI and Cy5 filter cubes, Hamamatsu ORCA FLASH4.0 sCMOS camera (500 ms exposure time per plane for Quasar 670).

Pixel size 100 nm XY.

Z-step size 200 nm.

32 planes (power of 2 is optimal for GPU deconvolution). With 500 ms exposure time, the Quasar 670 GADPH FISH probes images …

Transformation Of Stimulus Correlations By The Retina, Kristina D. Simmons, Jason Prentice, Gašper Tkačik, Jan Homann, Heather K. Yee, Stephanie E. Palmer, Philip C. Nelson, Vijay Balasubramanian

Publications and Research

Redundancies and correlations in the responses of sensory neurons may seem to waste neural resources, but they can also carry cues about structured stimuli and may help the brain to correct for response errors. To investigate the effect of stimulus structure on redundancy in retina, we measured simultaneous responses from populations of retinal ganglion cells presented with natural and artificial stimuli that varied greatly in correlation structure; these stimuli and recordings are publicly available online. Responding to spatio-temporally structured stimuli such as natural movies, pairs of ganglion cells were modestly more correlated than in response to white noise checkerboards, but …

Developmental And Molecular Functions Of Plakophilin-3, William A. Munoz

Dissertations & Theses (Open Access)

Plakophilin-3, the less studied member of the plakophilin-catenin subfamily, and the larger catenin family, binds directly to desmosomal cadherin cytoplasmic domains and enhances desmosome formation and stability. In mammals, plakophilin-3 is expressed at the highest levels in desmosome-enriched tissues such as epithelia, with the knock-out in mice producing corresponding reductions in ectodermal integrity. In tissue, cellular and intracellular contexts where plakophilin-3 is not at the desmosomal plaque, little is known about its functions in the cytoplasm or nucleus, where it also localizes.

My work employed embryos of the amphibian, Xenopus laevis, to examine plakophilin-3’s developmental roles. I first evaluated …

Development Of Novel Subunit Vaccine Against H5n1 Influenza, Lu Zhang

Graduate Theses and Dissertations

Influenza is a common infectious disease resulting from a frequently mutated RNA virus. Vaccination is currently the most effective method to prevent people from seasonal or pandemic influenza. The production of traditional egg-based influenza vaccine is time-consuming and provides limited effect against new strains. Therefore, it is necessary to develop a rapid method to produce influenza vaccines. We proposed a novel influenza vaccine based on the E.coli expression system. Hemagglutinin (HA) is the major target surface protein of influenza virus for vaccine development. In this study, we sub-cloned the HAs encoding gene into an E. coli expression vector; the signal …

Protective Effects Of Sphingomyelin Against Uv Photodamage In Human Keratinocytes, Kathleen De Guzman

Master's Theses

Ultraviolet (UV) radiation has been demonstrated in numerous studies to be a major risk factor for non-melanoma skin cancer development. Despite the emergence of current UV-preventative strategies, such as sunscreens and skin-protective clothing, the incidence of non-melanoma skin cancer has continued to rise. This has encouraged investigations on alternative methods for UV prevention. In particular, bovine milk sphingomyelin has been studied for its potential in protecting human skin against UV photodamage. While the previous studies have suggested that sphingomyelin exhibits UV-protective properties in a human skin equivalent model, the exact mechanisms behind sphingomyelin’s photoprotective effects are yet unknown.

This thesis …

New Insights Into The Roles Of Human Dna Damage Checkpoint Protein Atr In The Regulation Of Nucleotide Excision Repair And Dna Damage-Induced Cell Death, Zhengke Li

Electronic Theses and Dissertations

Integrity of the human genome is frequently threatened by endogenous and exogenous DNA damaging reagents that may lead to genome instability and cancer. Cells have evolved multiple mechanisms to repair DNA damage or to eliminate the damaged cells beyond repair and to prevent diverse diseases. Among these are ataxia telangiectasia and Rad3-related (ATR)-mediated DNA damage checkpoint and nucleotide excision repair (NER) that are the major pathways by which cells handle ultraviolet C (UV-C)- or other exogenous genotoxin-induced bulky DNA damage. However, it is unclear how these 2 pathways may be coordinated. In this study we show that ATR physically interacts …

The Development Of An In Vivo Microdialysis Collection Method Of Cytokines From Brain Tissue, Anthony W. Herbaugh

Graduate Theses and Dissertations

In this thesis, different methods to improve the microdialysis collection procedure for cytokines from brain tissue are presented. The first method was based on stopped flow and results indicating that no significant difference in relative recovery between stopped flow and continuous flow are shown. The second method is an antibody bead-based enhancement method. With the antibody bead-based method, a 3.5 fold increase in the collected concentrations of Chemokine (C-C motif) Ligand 2 (CCL2) were observed. However, there was no significant increase in the in vivo collection efficiency of Interleukin-6 (IL-6) using the antibody enhancement. Finally the development of an in-house …

Stellaris Fishing 20131125mon Part 2 Of 2, George Mcnamara

George McNamara

Stellaris FISH dataset using three FISH probe sets.

Slides courtesy of Biosearch Technologies,

https://www.biosearchtech.com/store/product.aspx?catid=224,318,324

see http://stellarisfish.smugmug.com/ for online gallery by Biosearch.

This experiment was to evaluate the crosstalk between the Biosearch fluorophores:

Quasar 570

CAL Fluor Red 610 (CFR 610)

Quasar 670

DAPI (DNA counterstain)

Autofluorescence (green, but sometimes showing up in other channels).

and our lab's Leica DMI6000 fluorescence microscope with Leica filter sets:

DAPI

GFP (L5)

Cy3 (N3)

Texas Red (TxRed2)

Cy5 (Y5)

I also acquired green channel and red channel with exciter filters in our ASI excitation wheel:

GFP + 492 exciter

Texas Red (TxRed2) + 572 …

Transforming Growth Factor-Beta Receptor Signalling Is Modulated By Integrin-Linked Kinase, Stellar H. Boo

Electronic Thesis and Dissertation Repository

Transforming growth factor-beta 1 (TGF-β1) modulates regeneration after injury through induction of fibroblast proliferation, migration, and differentiation into myofibroblasts. Induction of myofibroblast differentiation by TGF-β1 requires expression of integrin-linked kinase (ILK). I now show that ILK interacts with TGF-β receptor type II (TβRII) in primary dermal fibroblasts. Further, colocalization of ILK and TβRII can be observed at the cell membrane and in intracellular vesicles. The association of TβRII and ILK does not require TGF-β1 stimulation, kinase activity of TGF-β1 receptor type I or TβRII, and it does not involve interactions between ILK and focal adhesion-associated proteins. When this interaction is …

Aspects Of The Innate Immune System In The Caribbean Octocoral Swiftia Exserta, Lorenzo P. Menzel

FIU Electronic Theses and Dissertations

The immune systems of cnidaria are important to study for two reasons: to gain a better understanding of the evolution of immune responses, and to provide a basis to partially redress the precipitous world-wide die-offs of reef corals, some of which have been attributed to diseases and stress. Many immune responses share ancient evolutionary origins and are common across many taxa.

Using Swiftia exserta, an azooxanthellate ahermatypic local octocoral, as a proxy model organism to study aspects of innate immunity in corals and cnidaria allows us to address both of the reasons listed above while not using endangered species. …

In-Situ Quantification Of The Interfacial Rheological Response Of Bacterial Biofilms To Environmental Stimuli, Patrick Rühs, Lukas Böni, Gerald Fuller, R. Inglis, Peter Fischer

Biology Department Faculty Works

Understanding the numerous factors that can affect biofilm formation and stability remain poorly understood. One of the major limitations is the accurate measurement of biofilm stability and cohesiveness in real-time when exposed to changing environmental conditions. Here we present a novel method to measure biofilm strength: interfacial rheology. By culturing a range of bacterial biofilms on an air-liquid interface we were able to measure their viscoelastic growth profile during and after biofilm formation and subsequently alter growth conditions by adding surfactants or changing the nutrient composition of the growth medium. We found that different bacterial species had unique viscoelastic growth …

Microtubule Severing At Crossover Sites By Katanin Generates Ordered Cortical Microtubule Arrays In Arabidopsis, Quan Zhang, Erica Fishel, Tyler Bertroche, Ram Dixit

Biology Faculty Publications & Presentations

Highlights

• Severing primarily depolymerizes the overlying CMT at crossover sites
• Severing probability increases nonlinearly with crossover time
• Katanin localizes to crossover sites and is required for severing
• Loss of katanin activity prevents the formation of coaligned CMT arrays

Summary
The noncentrosomal cortical microtubules (CMTs) of land plants form highly ordered parallel arrays that mediate cell morphogenesis by orienting cellulose deposition [1, 2 and 3]. Since new CMTs initiate from dispersed cortical sites at random orientations [4], parallel array organization is hypothesized to require selective pruning of CMTs that are not in the dominant orientation. Severing of CMTs at crossover sites …

Leica Microscope Gpu Deconvolution Stellaris Fish Dataset #1, George Mcnamara

George McNamara

McNamara 20131101Fri Leica widefield microscope CUDA Deconvolution Stellaris FISH probe cultured cells dataset #1.zip

A text file in the zip archive has experiment details. I am posting this online so that researchers - whether academic or commercial - can evaluate the acquired data, the Bruce and Butte 2013 Optics Express ( http://www.opticsinfobase.org/oe/fulltext.cfm?uri=oe-21-4-4766 ) deconvolution result (note: I may not have used optimal settings), and to compare these deconvolution results to other methods. If anyone generates alternative spatial deconvolution output, such as from: * SVI Huygens * Media Cy AutoQuant * Agard's ER-Decon (Arigovindan 2013 PNAS) * Vicidomini SGP GPU Deconv …

Novel Neuroprotective Function Of Apical-Basal Polarity Genecrumbs In Amyloid Beta 42 (Aβ42) Mediated Neurodegeneration, Andrew Steffensmeier, Meghana Tare, Oorvashi Roy Puli, Rohan Modi, Jaison Nainaparampil, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

Alzheimer's disease (AD, OMIM: 104300), a progressive neurodegenerative disorder with no cure to date, is caused by the generation of amyloid-beta-42 (Aβ42) aggregates that trigger neuronal cell death by unknown mechanism(s). We have developed a transgenic Drosophilaeye model where misexpression of human Aβ42 results in AD-like neuropathology in the neural retina. We have identified an apical-basal polarity gene crumbs (crb) as a genetic modifier of Aβ42-mediated-neuropathology. Misexpression of Aβ42 caused upregulation of Crb expression, whereas downregulation of Crb either by RNAi or null allele approach rescued the Aβ42-mediated-neurodegeneration. Co-expression of full length Crb with Aβ42 increased severity of Aβ42-mediated-neurodegeneration, …

Identification And Rna Binding Characterization Of Plant Virus Rna Silencing Suppressor Proteins, Jeff Vargason, Carissa J. Burch, Jesse W. Wilson

Faculty Publications - Department of Biological & Molecular Science

Suppression is a common mechanism employed by viruses to evade the antiviral effects of the host’s RNA silencing pathway. The activity of suppression has commonly been localized to gene products in the virus, but the variety of mechanisms used in suppression by these viral proteins spans nearly the complete biochemical pathway of RNA silencing in the host. This review describes the agrofiltration assay and a slightly modified version of the agro-infiltration assay called co-infiltration, which are common methods used to observe RNA silencing and identify viral silencing suppressor proteins in plants, respectively. In addition, this review will provide an overview …

Long-Distance Translocation Of Photosynthates: A Primer [Review Article], Michael Knoblauch, Winfried S. Peters

Winfried S. Peters

Killerflip: A Novel Lytic Peptide Specifically Inducing Cancer Cell Death, B Pennarun, G. Gaidos, O Bucur, A Tinari

Dartmouth Scholarship

One of the objectives in the development of effective cancer therapy is induction of tumor-selective cell death. Toward this end, we have identified a small peptide that, when introduced into cells via a TAT cell-delivery system, shows a remarkably potent cytoxicity in a variety of cancer cell lines and inhibits tumor growth in vivo, whereas sparing normal cells and tissues. This fusion peptide was named killer FLIP as its sequence was derived from the C-terminal domain of c-FLIP, an anti-apoptotic protein. Using structure activity analysis, we determined the minimal bioactive core of killerFLIP, namely killerFLIP-E. Structural analysis of cells using …

Supervillin Binding To Myosin Ii And Synergism With Anillin Are Required For Cytokinesis, Tara C. Smith, Peter C. Fridy, Yinyin Li, Shruti Basil, Sneha Arjun, Ryan M. Friesen, John D. Leszyk, Brian T. Chait, Michael P. Rout, Elizabeth J. Luna

Elizabeth J. Luna

Cytokinesis, the process in which cytoplasm is apportioned between dividing daughter cells, requires coordination of myosin II function, membrane trafficking and central spindle organization. Most known regulators act during late cytokinesis; a few, including the myosin II-binding proteins anillin and supervillin, act earlier. Anillin's role in scaffolding the membrane cortex with the central spindle is well established, but the mechanism of supervillin action is relatively uncharacterized. We show here that two regions within supervillin affect cell division: residues 831-1281, which bind central spindle proteins, and residues 1-170, which bind the myosin II heavy chain (MHC) and the long form of …

Artificial Yeast Polarization Controlled By Chemical Gradient, James K. Nolan, Bernard Tao

The Summer Undergraduate Research Fellowship (SURF) Symposium

Engineering synthetic multicellular systems will lead to new synthetic biology technological platforms, inform developmental biology through recapitulation of natural systems and possibly unveil novel morphologies with practical applications not before reached throughout natural history (Maharbiz, 2012). Creating an exogenous molecular circuit that will polarize unicellular cells into “apical” and “basal” domains relative to a substrate plane would fulfill a missing component towards fully multicellular synthetic cellular communities (Maharbiz, 2012). To this end, a PIP₃ polarization network previously designed by Chau and associates (Chau, Walter, Gerardin, Tang, Lim 2012) was coupled to the specific activation by niacin of a recombinant …

Development Of A Conditional Mesd (Mesoderm Development) Allele For Functional Analysis Of The Low-Density Lipoprotein Receptor-Related Family In Defined Tissues, Andrew V. Taibi, Janet K. Lighthouse, Richard C. Grady, Kenneth R. Shroyer, Bernadette Holdener

Department of Biomedical Engineering Faculty Publications

The Low-density lipoprotein receptor-Related Protein (LRP) family members are essential for diverse processes ranging from the regulation of gastrulation to the modulation of lipid homeostasis. Receptors in this family bind and internalize a diverse array of ligands in the extracellular matrix (ECM). As a consequence, LRPs regulate a wide variety of cellular functions including, but not limited to lipid metabolism, membrane composition, cell motility, and cell signaling. Not surprisingly, mutations in single human LRPs are associated with defects in cholesterol metabolism and development of atherosclerosis, abnormalities in bone density, or aberrant eye vasculature, and may be a contributing factor in …

Measuring And Modeling The Response Characteristics Of The Environmental Phosphate Transducer In Escherichia Coli, Chetan Sood

Open Access Dissertations

The PhoR/PhoB two-component system in Escherichia coli is a biological transducer that senses the limitation of environmental inorganic orthophosphate, the bacteria's preferred source of the essential nutrient phosphate, and transmits that information to the interior of the cell initiating a response that mitigates phosphate starvation. In the first part of this study, we present and apply a fluorescence microscopy technique to measure, in vivo, the dynamic response characteristics of the transducer with single-cell resolution. We report that the transience in the PhoR/PhoB TCS response is consistent with the transducer having a threshold sensitivity to the concentration of environmental phosphate, …

Establishing The Role Of The Pancreatic Transcription Factor Mist1 In Xbp1-Mediated Maintenance Of Pancreatic Acinar Cell Homeostasis, David Alan Hess

Open Access Dissertations

Pancreatic acinar cells (PACs) continuously produce more protein than any other cell type in the human body. As a result, PACs and other specialized secretory cells have a constant demand placed on their protein synthetic and packaging machinery. When demand for secreted products exceeds the capacity of the cell's basal protein production facilities, dangerous accumulations of misfolded proteins can build up, resulting in a condition known as ER stress. To ameliorate this stress, secretory cells activate a coordinated, three-part compensatory network collectively known as the unfolded protein response (UPR) to both expand the capacity of the ER and directly assist …

Fibers In The Extracellular Matrix Enable Long-Range Stress Transmission Between Cells, Xiaoyue Ma, Maureen Schickel, Mark Stevenson, Alisha Sarang-Sieminski, Keith Gooch, Samir Ghadiali, Richard Hart

Alisha L. Sarang-Sieminski

Cells can sense, signal, and organize via mechanical forces. The ability of cells to mechanically sense and respond to the presence of other cells over relatively long distances (e.g., ∼100 μm, or ∼10 cell-diameters) across extracellular matrix (ECM) has been attributed to the strain-hardening behavior of the ECM. In this study, we explore an alternative hypothesis: the fibrous nature of the ECM makes long-range stress transmission possible and provides an important mechanism for long-range cell-cell mechanical signaling. To test this hypothesis, confocal reflectance microscopy was used to develop image-based finite-element models of stress transmission within fibroblast-seeded collagen gels. Models that …

Protein Kinase Ck2 Phosphorylates And Activates P21-Activated Kinase 1, Yong Jae Shin, Yong-Bae Kim, Jeong-Ho Kim

Biochemistry and Molecular Medicine Faculty Publications

Activation of the p21-activated kinase 1 (PAK1) is achieved through a conformational change that converts an inactive PAK1 dimer to an active monomer. In this paper, we show that this change is necessary but not sufficient to activate PAK1 and that it is, rather, required for CK2-dependent PAK1S223 phosphorylation that converts a monomeric PAK1 into a catalytically active form. This phosphorylation appears to be essential for autophosphorylation at specific residues and overall activity of PAK1. A phosphomimetic mutation (S223E) bypasses the requirement for GTPases in PAK1 activation, whereas the constitutive activity of the PAK1 mutant (PAK1H83,86L), postulated to mimic GTPase-induced …

Identification Of Proteins Potentially Involved In The Formation Of Lafora Bodies, A Hallmark Of Lafora Disease, Elham Schokraie, Oliver Kötting, Matthew S. Gentry

Molecular and Cellular Biochemistry Presentations

Lafora Disease (LD) is a fatal teenage-onset progressive myoclonus epilepsy. It is characterized by the formation of Lafora bodies (LBs), deposits of abnormally branched, insoluble, hyperphosphorylated glycogen-like polymers that are generally believed to trigger the development of the clinical symptoms of LD. 58% and 35% of the LD cases are caused by mutations in EPM2A (laforin) and EPM2B (malin), respectively. However, little is known about their function in LB formation. Two different mechanisms have been proposed to explain the accumulation of insoluble LBs: first, excessive glycogen phosphorylation and, second, an imbalance between glycogen synthesizing enzymes. The present study aims at …

Effects Of Butyltins On Mitogen-Activated-Protein Kinase Kinase Kinase And Ras Activity In Human Natural Killer Cells, Lindsay J. Celada, Margaret M. Whalen

Chemistry Faculty Research

Butyltins (BTs) contaminate the environment and are found in human blood. BTs, tributyltin (TBT) and dibutyltin (DBT) diminish the cytotoxic function and levels of key proteins of human natural killer (NK) cells. NK cells are an initial immune defense against tumors, virally infected cells and antibody-coated cells and thus critical to human health. The signaling pathways that regulate NK cell functions include mitogen-activated protein kinases (MAPKs). Studies have shown that exposure to BTs leads to activation of specific MAPKs and MAPK kinases (MAP2Ks) in human NK cells. MAP2K kinases (MAP3Ks) are upstream activators of MAP2Ks, which then activate MAPKs. The …

Stomatin-Like Protein 2 Deficiency In T Cells Is Associated With Altered Mitochondrial Respiration And Defective Cd4+ T Cell Responses., Darah A Christie, Panagiotis Mitsopoulos, Julianna Blagih, Stanley D Dunn, Julie St-Pierre, Russell G Jones, Grant M Hatch, Joaquín Madrenas

Stanley D Dunn

Stomatin-like protein 2 (SLP-2) is a mostly mitochondrial protein that regulates mitochondrial biogenesis and function and modulates T cell activation. To determine the mechanism of action of SLP-2, we generated T cell-specific SLP-2-deficient mice. These mice had normal numbers of thymocytes and T cells in the periphery. However, conventional SLP-2-deficient T cells had a posttranscriptional defect in IL-2 production in response to TCR ligation, and this translated into reduced CD4(+) T cell responses. SLP-2 deficiency was associated with impaired cardiolipin compartmentalization in mitochondrial membranes, decreased levels of the NADH dehydrogenase (ubiquinone) iron-sulfur protein 3, NADH dehydrogenase (ubiquinone) 1β subcomplex subunit …

The Role Of Ykl-40 In The Progression Of Glioblastoma, Ralph Anthony Francescone

Open Access Dissertations

Glioblastoma Multiforme (GBM) is the most common brain cancer and one of the most fatal forms of cancer overall. The average survival time is 10-14 months, and less than 10% of patients survive more than 5 years after diagnosis. It is characterized by extreme vasculature, chemo/radioresistance, and invasiveness into the normal brain. The current standard of care, which includes surgical removal of tumor, radiation, and the chemotherapeutic agent temozolomide, initially stunt tumor growth. Nevertheless, the tumor invariably rebounds and the patient succumbs to the disease. Therefore, there is an urgent need to develop new therapies for this devastating disease.

YKL-40 …