Cell and Developmental Biology Commons^™

Y-Like Retinal Ganglion Cells Innervate The Dorsal Raphe Nucleus In The Mongolian Gerbil (Meriones Unguiculatus), Liju Luan, Chaoran Ren, Benson Wui-Man Lau, Jian Yang, Gary E. Pickard, Kwok-Fai So, Mingliang Pu

School of Veterinary and Biomedical Sciences: Faculty Publications

Background: The dorsal raphe nucleus (DRN) of the mesencephalon is a complex multi-functional and multi-transmitter nucleus involved in a wide range of behavioral and physiological processes. The DRN receives a direct input from the retina. However little is known regarding the type of retinal ganglion cell (RGC) that innervates the DRN. We examined morphological characteristics and physiological properties of these DRN projecting ganglion cells.

Methodology/Principal Findings: The Mongolian gerbils are highly visual rodents with a diurnal/crepuscular activity rhythm. It has been widely used as experimental animals of various studies including seasonal affective disorders and depression. Young adult gerbils were used …

Challenges And Opportunities For Toxicology In Mexico, Rodrigo Franco, Balam Muñoz

School of Veterinary and Biomedical Sciences: Faculty Publications

We have developed this Special Issue titled “Challenges and Opportunities for Toxicology in Mexico” with the aim to highlight not only the challenges toxicology research faces in Mexico, but also the efforts and drive towards cutting edge research to address them. Altogether, this special issue should be a valuable source of information for all readers with an interest in toxicology and human health.

Mexico is an important economy worldwide and is a major exporter of several supplies and commodities. Because of this, its industry is a source of occupational exposure to several chemical derivatives (Nieusma 2011). The situation of occupational …

An Upper Limit For Macromolecular Crowding Effects, Andrew C. Miklos, Congang Li, Courtney D. Sorell, L. Andrew Lyon, Gary J. Pielak

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Background: Solutions containing high macromolecule concentrations are predicted to affect a number of protein properties compared to those properties in dilute solution. In cells, these macromolecular crowders have a large range of sizes and can occupy 30% or more of the available volume. We chose to study the stability and ps-ns internal dynamics of a globular protein whose radius is similar to 2 nm when crowded by a synthetic microgel composed of poly(N-isopropylacrylamide-co-acrylic acid) with particle radii of similar to 300 nm.

Results: Our studies revealed no change in protein rotational or ps-ns backbone dynamics and only mild …

Quantifying Agonist Activity At G Protein-Coupled Receptors, Frederick J. Ehlert, Hinako Suga, Michael T. Griffin

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

When an agonist activates a population of G protein-coupled receptors (GPCRs), it elicits a signaling pathway that culminates in the response of the cell or tissue. This process can be analyzed at the level of a single receptor, a population of receptors, or a downstream response. Here we describe how to analyze the downstream response to obtain an estimate of the agonist affinity constant for the active state of single receptors.

Receptors behave as quantal switches that alternate between active and inactive states (Figure 1). The active state interacts with specific G proteins or other signaling partners. In the absence …

Cooperative And Antagonistic Roles For Heterochromatin Proteins In Transcriptional Regulation Of The Drosophila Sex Determination Masterswitch Gene, Hui Li

University of Kentucky Doctoral Dissertations

HOAP was originally identified as a component of an ORC-containing multi-protein complex of Heterochromatin Protein 1 (HP1) from early Drosophila embryos. HOAP immunostaining showed prominent association of it with telomeres, and mutants for HOAP (cav¹) showed it functions along with HP1 in forming a telomere capping complex that prevents telomeric fusions.

Weaker HOAP immunostaining is also observed in regions of pericentric heterochromatin and euchromatin. To examine the role of HOAP at these non-telomeric sites, we applied Affymetric Drosophila Genome Arrays to undertake a microarray expression profiling study of genes that are mis-expressed in cav¹ mutant larvae. The …

Escherichia Coli Fpg Glycosylase Is Nonrendundant And Required For The Rapid Global Repair Of Oxidized Purine And Pyrimidine Damage In Vivo, Brandy J. Schalow, Charmain T. Courcelle, Justin Courcelle

Biology Faculty Publications and Presentations

Endonuclease (Endo) III and formamidopyrimidine-N-glycosylase (Fpg) are two of the predominant DNA glycosylases in Escherichia coli that remove oxidative base damage. In cell extracts and purified form, Endo III is generally more active toward oxidized pyrimidines, while Fpg is more active towards oxidized purines. However, the substrate specificities of these enzymes partially overlap in vitro. Less is known about the relative contribution of these enzymes in restoring the genomic template following oxidative damage. In this study, we examined how efficiently Endo III and Fpg repair their oxidative substrates in vivo following treatment with hydrogen peroxide. We found …

Biphasic Targeting And Cleavage Furrow Ingression Directed By The Tail Of A Myosin Ii, X. Fang, J. Y. Luo, R. Nishihama, C. Wloka, C. Dravis, M. Travaglia, M. Iwase, Elizabeth Ann Vallen, E. Bi

Biology Faculty Works

Cytokinesis in animal and fungal cells utilizes a contractile actomyosin ring (AMR). However, how myosin II is targeted to the division site and promotes AMR assembly, and how the AMR coordinates with membrane trafficking during cytokinesis, remains poorly understood. Here we show that Myo1 is a two-headed myosin II in Saccharomyces cerevisiae, and that Myo1 localizes to the division site via two distinct targeting signals in its tail that act sequentially during the cell cycle. Before cytokinesis, Myo1 localization depends on the septin-binding protein Bni5. During cytokinesis, Myo1 localization depends on the IQGAP Iqg1. We also show that the Myo1 …

Mosaic Analysis With Double Markers (Madm) As A Method To Map Cell Fates In Adult Mouse Taste Buds., Preston D. Moore

Electronic Theses and Dissertations

Taste buds are chemosensory endorgans embedded in the oral epithelium composed of cells that undergo continuous replacement. Mature taste cells live on average 10-14 days and are replaced by new cells when they die. However, the mechanism by which taste cells are produced and integrated into the taste bud as mature taste cells remains unknown. Previous studies approached this issue from either cell cycle gene expression properties or lineage tracing of precursor cells. In our study, we apply a new fate mapping technique that combines these two ideas. This technique, Mosaic Analysis with Double Markers, allows for simultaneous gene knockout …

The Roles Of Elevated Bcl-2 In Ovarian Cancer, Nicole Shree Anderson

USF Tampa Graduate Theses and Dissertations

Ovarian cancer (OC) is the second most common gynecologic cancer; however it is responsible for the most gynecologic cancer-related deaths. Apoptosis evasion is an important mechanism in OC tumorigenesis, and the prototypic anti-apoptotic protein, B-cell lymphoma 2 (Bcl-2), is often overexpressed in OC tumors. Gaining a better understanding of the mechanism(s) behind Bcl-2 overexpression and potential extra-anti-apoptotic functions of Bcl-2 could elucidate the importance of elevated Bcl-2 in OC. In the current study, I show through immunohistochemical analysis of normal, benign, and OC tissue sections, that both epithelial and stromal Bcl-2 expression decreases with OC progression. However, the number of …

Development Of A Genetic Modification System In Clostridium Scatologenes Atcc 25775 For Generation Of Mutants, Prasanna Tamarapu Parthasarathy

Masters Theses & Specialist Projects

3-Methyl indole (3-MI) is a malodorant in food and animal waste and Clostridium scatologenes ATCC 25775 is the model organism for the study of 3-MI production. 3-MI is an anaerobic degradation product of L-tryptophan and can cause pulmonary disorders and death in cattle and goats. To elucidate the 3-MI biosynthesis pathway and the underlying genes, it is necessary to develop a system to allow genetic modification in Clostridium scatologenes ATCC 25775. Bacteriophages and transposons are useful tools to achieve this goal. Isolation of Clostridium scatologenes ATCC 25775 bacteriophage was attempted by prophage induction and enrichments using environmental sources. To induce …

Analyzing The Role Of Αvβ8 Integrin In Glioma-Induced Angiogenesis, Jeremy H. Tchaicha

Dissertations and Theses (Open Access)

In this study we aimed to determine the functional roles for αvβ8 integrin in astrocytoma-induced angiogenesis. These studies originate from our analyses of αvβ8 integrin in developmental brain angiogenesis. αv and β8 knockout (KO) mice develop brain-specific vascular phenotypes that resemble vascular pathologies observed in the malignant astrocytoma, glioblastoma multiforme (GBM). Indeed, a murine xenograft model of astrocytoma suggested a role for the integrin in glioma-induced angiogenesis. Primary mouse astroglia were cultured from wild type (WT) and β8 KO neonates and were immortalized (HPV:E6/E7) and transformed (HRas:G12V). WT and β8 KO transformed astroglia were intracranially injected into athymic mice. WT …

Dynamic Remodeling Of The Stressed Heart: Role Of Protein Degradation Pathways, Deborah Vela

Dissertations and Theses (Open Access)

The heart is a remarkable organ. In order to maintain its function, it remodels in response to a variety of environmental stresses, including pressure overload, volume overload, mechanical or pharmacological unloading and hormonal or metabolic disturbances. All these responses are linked to the inherent capacity of the heart to rebuild itself. Particularly, cardiac pressure overload activates signaling pathways of both protein synthesis and degradation. While much is known about regulators of protein synthesis, little is known about regulators of protein degradation in hypertrophy. The ubiquitin-proteasome system (UPS) selectively degrades unused and abnormal intracellular proteins. I speculated that the UPS may …

Mcam/Muc18 Regulates Melanoma Progression By Modulating The Expression Of Id-1, Maya Zigler

Dissertations and Theses (Open Access)

The acquisition of the metastatic melanoma phenotype is associated with increased expression of the melanoma cell adhesion molecule MCAM/MUC18 (CD146). However, the mechanism by which MUC18 contributes to melanoma metastasis remains unclear. Herein, we stably silenced MUC18 expression utilizing lentivirus-incorporated small hairpin RNA, in two metastatic melanoma cell lines, A375SM and C8161, and conducted cDNA microarray analysis. We identified and validated that the transcriptional regulator, Inhibitor of DNA Binding-1 (Id-1), previously shown to function as an oncogene in several malignancies, was downregulated by 5.6-fold following MUC18 silencing. Additionally, we found that MUC18 regulated Id-1 expression at the transcriptional level via …

Production, Purification And Crystallization Of Membrane Integrated Multimeric Bax, Adelbert Mark Villoso

UNLV Theses, Dissertations, Professional Papers, and Capstones

Apoptosis, or programmed cell death, is a vital process intimately involved in the embryonic development and homeostatic maintenance of all multicellular organisms. The committing step to apoptosis is regulated by a key protein, Bax, and its ability to integrate and form a pore structure at the outer mitochondrial membrane.

Unfortunately, the molecular details of apoptosis remain largely unclear due to the lack of structural data of integral membrane (IM) Bax. Experimental limitations of membrane protein production have slowed the pursuit of an IM-Bax structure simply because standard protocols for producing recombinant IM-Bax are inefficient in producing adequate quantities of IM-Bax …

Role Of Alpha 7 Nicotinic Acetylcholine Receptor In Calcium Signaling Induced By Prion Protein Interaction With Stress-Inducible Protein 1, Flavio H. Beraldo, Camila P. Arantes, Tiago G. Santos, Nicolle G. T. Queiroz, Kirk Young, Jane R. Rylett, Regina P. Markus, Marco A. M. Prado, Vilma R. Martins

Anatomy and Cell Biology Publications

The prion protein (PrP(C)) is a conserved glycosylphosphatidyl-inositol-anchored cell surface protein expressed by neurons and other cells. Stress-inducible protein 1 (STI1) binds PrP(C) extracellularly, and this activated signaling complex promotes neuronal differentiation and neuroprotection via the extracellular signal-regulated kinase 1 and 2 (ERK1/2) and cAMP-dependent protein kinase 1 (PKA) pathways. However, the mechanism by which the PrPC-STI1 interaction transduces extracellular signals to the intracellular environment is unknown. We found that in hippocampal neurons, STI1-PrP(C) engagement induces an increase in intracellular Ca(2+) levels. This effect was not detected in PrP(C)-null neurons or wild-type neurons treated with an STI1 mutant unable to …

Proteoliposome Proton Flux Assays Establish Net Conductance, Ph-Sensitivity, And Functional Integrity Of A Novel Truncate Of The M2 Ion "Channel" Of Influenza A, Emily Peterson

Theses and Dissertations

A novel truncate of Influenza A M2 protein (residues 22-62), incorporated into a uniquely tailored proteoliposome proton uptake assay, demonstrated proton flux more characteristic of an ion transporter than a traditional ion "channel." The liposome paradigm was essential for testing the conductance activity of this M2 truncate at a range of extraphysiological pHs appropriate for channel vs. transport function determination. In addition to transporter-typical proton flux, M2(22-62) showed the key characteristics of functional integrity: selective proton uptake into liposomes and block of uptake by amantadine. Two sets of proteoliposome proton flux assays were carried out, Set 1 at pH values …

Characterization Of The Lkb1-Mo25-Strad Ampkk Complex In Adult Mouse Skeletal Muscle, Cody Don Smith

Theses and Dissertations

In liver tissue, the AMP-activated protein kinase kinase (AMPKK) complex was identified as the association of LKB1, MO25α/β, and STRADα/β proteins; however, this complex has yet to be characterized in skeletal muscle. In this report, we demonstrate the expression of the LKB1-MO25-STRAD AMPKK complex in adult skeletal muscle, confirm the absence of mRNA splice variants, and report the relative mRNA expression levels of these complex-forming proteins. To facilitate this characterization we used control (ctrl) and muscle-specific LKB1 knockout (LKB1-/-) mice. LKB1 detection in untreated ctrl and LKB1-/- muscle lysates revealed two protein bands at approximately 50 and 60 kDa; although, …

Virulence Of An Emerging Respiratory Pathogen, Genus Pandoraea, In Vivo And Its Interactions With Lung Epithelial Cells, Gillian Herbert, Anne Costello, Lydia Fabunmi, Kirsten Schaffer, Kevin Kavanagh, Emma M. Caraher, Máire Callaghan, Siobhan Mcclean

Articles

Pandoraea species have emerged as opportunistic pathogens among cystic fibrosis (CF) and non-CF patients. Pandoraea pulmonicola is the predominant Pandoraea species among Irish CF patients. The objective of this study was to investigate the pathogenicity and potential mechanisms of virulence of Irish P. pulmonicola isolates and strains from other Pandoraea species. Three patients from whom the P. pulmonicola isolates were isolated have since died. The in vivo virulence of these and other Pandoraea strains was examined by determining the ability to kill Galleria mellonella larvae. The P. pulmonicola strains generally were the most virulent of the species tested, with three …

Cyanidin-3-Glucoside Inhibits Ethanol-Induced Invasion Of Breast Cancer Cells Overexpressing Erbb2, Mei Xu, Kimberly A. Bower, Siying Wang, Jacqueline A. Frank, Gang Chen, Min Ding, Shiow Wang, Xianglin Shi, Zunji Ke, Jia Luo

Internal Medicine Faculty Publications

BACKGROUND: Ethanol is a tumor promoter. Both epidemiological and experimental studies suggest that ethanol may enhance the metastasis of breast cancer cells. We have previously demonstrated that ethanol increased the migration/invasion of breast cancer cells expressing high levels of ErbB2. Amplification of ErbB2 is found in 20-30% of breast cancer patients and is associated with poor prognosis. We sought to identify agents that can prevent or ameliorate ethanol-induced invasion of breast cancer cells. Cyanidin-3-glucoside (C3G), an anthocyanin present in many vegetables and fruits, is a potent natural antioxidant. Ethanol exposure causes the accumulation of intracellular reactive oxygen species (ROS). This …

Quantitative Trait Loci Mapping Reveals Candidate Pathways Regulating Cell Cycle Duration In Plasmodium Falciparum, Heather B. Reilly Ayala, Mark A. Wacker, Geoffrey Siwo, Michael T. Ferdig

Faculty Publications - Department of Biological & Molecular Science

Background: Elevated parasite biomass in the human red blood cells can lead to increased malaria morbidity. The genes and mechanisms regulating growth and development of Plasmodium falciparum through its erythrocytic cycle are not well understood. We previously showed that strains HB3 and Dd2 diverge in their proliferation rates, and here use quantitative trait loci mapping in 34 progeny from a cross between these parent clones along with integrative bioinformatics to identify genetic loci and candidate genes that control divergences in cell cycle duration. Results: Genetic mapping of cell cycle duration revealed a four-locus genetic model, including a major genetic effect …