Cell and Developmental Biology Commons^™

Conservation Of Freshwater Live-Bearing Fishes: Development Of Germplasm Repositories For Goodeids, Yue Liu

LSU Doctoral Dissertations

Fishes of the family Goodeidae are considered to be among the most imperiled taxa in the world. The goal of this project was to provide a foundation for development of sperm repositories for goodeids and to use them as a model to assist conservation programs for imperiled freshwater live-bearing fishes. Development of such repositories is challenging because of unusual reproductive characteristics of live-bearing fishes, such as sperm bundles, internal fertilization, and the bearing of live young. Standardized methods were established to evaluate quality-related attributes of sperm bundles. The different features between activation of free and bundled sperm were investigated and …

Loss Of Marv1 Promotes Chop Signaling In Mouse Liver, Shad Anthony Mitchell

Graduate School of Biomedical Sciences Theses and Dissertations

Metabolic syndrome (MetS) is a term used to define a set of metabolic diseases: obesity, type 2 diabetes (T2D), hyperlipidemia, hypertension, nonalcoholic fatty liver disease (NAFLD), and nonalcoholic hepatosteatosis (NASH). Those with MetS have a higher incidence of cardiovascular disease and stroke. Current drug treatments for MetS treat the individual pathologies associated with the diseases, rather than directly targeting MetS as a whole. We hypothesize that the inhibition of a ubiquitous lipid transporter known as ARV1 can improve pathologies associated with MetS. To test this hypothesis, we utilized liver tissue from mARV1 knockout mice fed a high-fat diet and examined …

Anemarrhena Asphodeloides Bunge And Its Constituent Timosaponin‐Aiii Induce Cell Cycle Arrest And Apoptosis In Pancreatic Cancer Cells, Catherine B. Marelia, Arielle Sharp, Tiffany A. Shemwell, Y. C. Zhang, Brant R. Burkhardt

Molecular Biosciences Faculty Publications

Pancreatic cancer is one of the most recalcitrant and lethal of all cancers. We examined the effects of Anemarrhena asphodeloides (AA) and timosaponin‐AIII (TAIII), a steroidal saponin present in AA, on pancreatic cancer cell proliferation and aimed to elucidate their potential apoptotic mechanisms of action. Viability assays and cell cycle analysis revealed that both AA and TAIII significantly inhibited pancreatic cancer cell proliferation and cell cycle progression compared to treatment with gemcitabine, the standard chemotherapeutic agent for advanced pancreatic cancer. We identified a dose‐dependent increase in caspase‐dependent apoptosis and activation of pro‐apoptotic PI3K/Akt pathway proteins, with a subsequent downregulation of …

Capn5 Expression In The Healthy And Regenerating Zebrafish Retina, Cagney E. Coomer, Ann C. Morris

Biology Faculty Publications

PURPOSE. Autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV) is a devastating inherited autoimmune disease of the eye that displays features commonly seen in other eye diseases, such as retinitis pigmentosa and diabetic retinopathy. ADNIV is caused by a gain-of-function mutation in Calpain-5 (CAPN5), a calcium-dependent cysteine protease. Very little is known about the normal function of CAPN5 in the adult retina, and there are conflicting results regarding its role during mammalian embryonic development. The zebrafish (Danio rerio) is an excellent animal model for studying vertebrate development and tissue regeneration, and represents a novel model to explore the …

Epigenetic Alterations Mediate Ipsc Normalization Of Dna-Repair Expression And Tnr Stability In Huntington's Disease, Peter A. Mollica, Martina Zamponi, John Reid, Deepak Sharma, Alyson E. White, Roy C. Ogle, Robert D. Bruno, Patrick C. Sachs

School of Medical Diagnostics & Translational Sciences Publications

Huntington's disease (HD) is a rare autosomal dominant neurodegenerative disorder caused by a cytosine-adenine-guanine (CAG) trinucleotide repeat (TNR) expansion within the HTT gene. The mechanisms underlying HD-associated cellular dysfunction in pluripotency and neurodevelopment are poorly understood. We had previously identified downregulation of selected DNA repair genes in HD fibroblasts relative to wild-type fibroblasts, as a result of promoter hypermethylation. Here, we tested the hypothesis that hypomethylation during cellular reprogramming to the induced pluripotent stem cell (iPSC) state leads to upregulation of DNA repair genes and stabilization of TNRs in HD cells. We sought to determine how the HD TNR region …

Dynamics And Interactions Of Membrane Proteins, Azamat Galiakhmetov

Dissertations (1934 -)

Membrane proteins are members of the class of proteins that perform their functions while being associated with a lipid bilayer. In the cell, they serve as transporters, receptors, anchors and enzymes. The domain organisation of these proteins suggests importance of lipid membrane and protein-lipid interactions for protein function. The requirement of a membrane mimic and the level of its resemblance to a native one for protein investigation makes the studies of membrane proteins a challenging project. My research work is focusing on the biophysical and biochemical studies of membrane proteins. This dissertation outlines two separate projects, each with their own …

Characterizing The Recognition Motif And Novel Substrates Of Carm1, Sitaram Gayatri

Dissertations and Theses (Open Access)

A limited pool of proteins attains vast functional repertoire due to posttranslational modifications (PTMs). Arginine methylation is a common posttranslational modification, which is catalyzed by a family of nine protein arginine methyltransferases or PRMTs. These enzymes deposit one or two methyl groups to the nitrogen atoms of arginine side-chains. Elucidating the substrate specificity of each PRMT will promote a better understanding of which signaling networks these enzymes contribute to. Although many PRMT substrates have been identified, and their methylation sites mapped, the optimal target motif for each of the nine PRMTs has not been systematically addressed. Here we describe the …

Strategies For The Modulation Of Protease Activated Receptors (Pars), Disha M. Gandhi

Dissertations (1934 -)

Protease-activated receptors (PARs) are class A G protein-coupled receptors (GPCRs) with 4 subtypes (PAR 1 – 4) and with a unique mode of action. PARs are cleaved by extracellular proteases at the N-terminus, creating a new tethered ligand that activates the receptor and transduces biological signals into the cell. PARs have been implicated in various productive and pathological signals, including those related to thrombosis, inflammation, reperfusion injury, and cancer cell metastasis. Despite the fact that PARs are attractive as drug targets, their intramolecular mode of activation makes it challenging to modulate them with drugs in a selective manner, and only …

Exploring The Role Of Rna Polymerase Iii Complex Assembly On Ribosomal Dna Silencing In Saccharomyces Cerevisiae, Kyle Thomas Kern

LSU Doctoral Dissertations

The yeast rDNA region is host to a number of transcriptional regulatory elements, which work in conjunction to generate essential RNA subunits of ribosomes, as well as protecting the region from DNA damage. The role of RNA polymerase III complex binding at the 5S gene on rDNA silencing in the NTS2 region was investigated, both by use of a TY1:MET15 reporter insert and a MET15 gene integration at an endogenous SphI site. It was discovered that Pol III complexes do have an effect on reporter expression in the NTS2 region, though the specific effect was different based on the method …

Design, Synthesis, And Evaluation Of Homochiral Peptides Containing Arginine And Histidine As Molecular Transporters, Naglaa Salem El-Sayed, Taryn Miyake, Amir Nasrolahi Shirazi, Shang Eun Park, Jimmy Clark, Stephani Buchholz, Keykavous Parang, Rakesh Tiwari

Pharmacy Faculty Articles and Research

Linear (HR)n and cyclic [HR]n peptides (n = 4,5) containing alternate arginine and histidine residues were synthesized. The peptides showed 0–15% cytotoxicity at 5–100 μM in human ovarian adenocarcinoma (SK-OV-3) cells while they exhibited 0–12% toxicity in human leukemia cancer cell line (CCRF-CEM). Among all peptides, cyclic [HR]4 peptide was able to improve the delivery of a cell impermeable fluorescence-labeled phosphopeptide by two-fold. Fatty acids of different alkyl chain length were attached at the N-terminal of the linear peptide (HR)4 to improve the molecular transporter property. Addition of fatty acyl chains was expected to help with the permeation of the …

Direct Cell-To-Cell Transmission Of Respiratory Viruses: The Fast Lanes, Nicolás P. Cifuentes-Muñoz, Rebecca Ellis Dutch, Roberto Cattaneo

Molecular and Cellular Biochemistry Faculty Publications

Virus particles protect genomes from hostile environments within and outside the host, eventually delivering these genomes to target tissues to initiate infection. Complex processes requiring significant energy and time are necessary to assemble these virus particles, but only a small portion of released virus will successfully infect new target cells (Fig 1A). While the science of virology has developed based on the isolation and purification of viral particles, it is becoming increasingly clear that direct cell-to-cell transmission of viruses and/or viral components is also highly relevant [1,2].

Direct cell-to-cell spread of infections has several advantages. The first is efficiency: genomic …

Novel Role Of Prostate Apoptosis Response-4 Tumor Suppressor In B-Cell Chronic Lymphocytic Leukemia, Mary Kathryn Mckenna, Sunil K. Noothi, Sara S. Alhakeem, Karine Z. Oben, Joseph T. Greene, Rajeswaran Mani, Kathryn L. Perry, James P. Collard, Jacqueline R. Rivas, Gerhard C. Hildebrandt, Roger A. Fleischman, Eric B. Durbin, John C. Byrd, Chi Wang, Natarajan Muthusamy, Vivek M. Rangnekar, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Prostate apoptosis response-4 (Par-4), a proapoptotic tumor suppressor protein, is downregulated in many cancers including renal cell carcinoma, glioblastoma, endometrial, and breast cancer. Par-4 induces apoptosis selectively in various types of cancer cells but not normal cells. We found that chronic lymphocytic leukemia (CLL) cells from human patients and from Eµ-Tcl1 mice constitutively express Par-4 in greater amounts than normal B-1 or B-2 cells. Interestingly, knockdown of Par-4 in human CLL-derived Mec-1 cells results in a robust increase in p21/WAF1 expression and decreased growth due to delayed G1-to-S cell-cycle transition. Lack of Par-4 also increased the expression of p21 and …

Roles Of Plods In Collagen Synthesis And Cancer Progression, Yifei Qi, Ren Xu

Markey Cancer Center Faculty Publications

Collagen is the major component of extracellular matrix. Collagen cross-link and deposition depend on lysyl hydroxylation, which is catalyzed by procollagen-lysine, 2-oxoglutarate 5-dioxygenase (PLOD). Aberrant lysyl hydroxylation and collagen cross-link contributes to the progression of many collagen-related diseases, such as fibrosis and cancer. Three lysyl hydroxylases (LH1, LH2, and LH3) are identified, encoded by PLOD1, PLOD2, and PLOD3 genes. Expression of PLODs is regulated by multiple cytokines, transcription factors and microRNAs. Dysregulation of PLODs promotes cancer progression and metastasis, suggesting that targeting PLODs is potential strategy for cancer treatment. Here, we summarize the recent progress in the investigation of …

Synthesis Of Interleukin 1 Beta And Interleukin 6 In Human Lymphocytes Is Stimulated By Tributyltin, Shyretha Brown, Mariam Boules, Nafisa Hamza, Xiaofei Wang, Margaret Whalen

Chemistry Faculty Research

Tributyltin (TBT) is a widespread environmental contaminant that is present in human blood and other tissues. It has been shown to disrupt the immune function of human natural killer (NK) cells and to alter the secretion of a number of pro-inflammatory cytokines from immune cells. Secretion of both interleukin 1β (IL-1β) and interleukin 6 (IL-6) from human lymphocytes can be increased dependent upon the level of TBT exposure. This study shows that the TBT-induced increases in secretion of both cytokines are due to TBT-induced increases in the synthesis of these proteins and not simply because of the release of pre-existing …

Efficient Intracellular Delivery Of Cell-Impermeable Cargo Molecules By Peptides Containing Tryptophan And Histidine, Amir Nasrolahi Shirazi, Saghar Mozaffari, Rinzhin Tshering Sherpa, Rakesh Tiwari, Keykavous Parang

Pharmacy Faculty Articles and Research

We have previously evaluated and reported numerous classes of linear and cyclic peptides containing hydrophobic and hydrophilic segments for intracellular delivery of multiple molecular cargos. Herein, a combination of histidine and tryptophan amino acids were designed and evaluated for their efficiency in intracellular delivery of cell-impermeable phosphopeptides and the anti-HIV drug, emtricitabine. Two new decapeptides, with linear and cyclic natures, both containing alternate tryptophan and histidine residues, were synthesized using Fmoc/tBu solid-phase chemistry. The peptides were characterized and purified by using matrix-assisted laser desorption/ionization (MALDI) spectroscopy and high-performance liquid chromatography (HPLC), respectively. These peptides did not show significant toxicity up …

Snf1 Cooperates With The Cwi Mapk Pathway To Mediate The Degradation Of Med13 Following Oxidative Stress, Stephen D Willis, David C Stieg, Kai Li Ong, Ravina Shah, Alexandra K. Strich, Julianne H Grose, Katrina F Cooper

Rowan-Virtua School of Osteopathic Medicine Departmental Research

Eukaryotic cells, when faced with unfavorable environmental conditions, mount either pro-survival or pro-death programs. The conserved cyclin C-Cdk8 kinase plays a key role in this decision. Both are members of the Cdk8 kinase module that, along with Med12 and Med13, associate with the core Mediator complex of RNA polymerase II. In Saccharomyces cerevisiae, oxidative stress triggers Med13 destruction, which releases cyclin C into the cytoplasm to promote mitochondrial fission and programmed cell death. The SCFGrr1 ubiquitin ligase mediates Med13 degradation dependent on the cell wall integrity pathway, MAPK Slt2. Here we show that the AMP kinase Snf1 activates a second …

N-Glycosylation Regulates Pannexin 2 Localization But Is Not Required For Interacting With Pannexin 1., Rafael E Sanchez-Pupo, Danielle Johnston, Silvia Penuela

Anatomy and Cell Biology Publications

Pannexins (Panx1, 2, 3) are channel-forming glycoproteins expressed in mammalian tissues. We previously reported that N-glycosylation acts as a regulator of the localization and intermixing of Panx1 and Panx3, but its effects on Panx2 are currently unknown. Panx1 and Panx2 intermixing can regulate channel properties, and both pannexins have been implicated in neuronal cell death after ischemia. Our objectives were to validate the predicted N-glycosylation site of Panx2 and to study the effects of Panx2 glycosylation on localization and its capacity to interact with Panx1. We used site-directed mutagenesis, enzymatic de-glycosylation, cell-surface biotinylation, co-immunoprecipitation, and confocal microscopy. Our results showed …

Comparative Analysis Of Mutant Huntingtin Binding Partners In Yeast Species., Yanding Zhao, Ashley A Zurawel, Nicole P Jenkins, Martin L Duennwald, Chao Cheng, Arminja N Kettenbach, Surachai Supattapone

Anatomy and Cell Biology Publications

Huntington's disease is caused by the pathological expansion of a polyglutamine (polyQ) stretch in Huntingtin (Htt), but the molecular mechanisms by which polyQ expansion in Htt causes toxicity in selective neuronal populations remain poorly understood. Interestingly, heterologous expression of expanded polyQ Htt is toxic in Saccharomyces cerevisiae cells, but has no effect in Schizosaccharomyces pombe, a related yeast species possessing very few endogenous polyQ or Q/N-rich proteins. Here, we used a comprehensive and unbiased mass spectrometric approach to identify proteins that bind Htt in a length-dependent manner in both species. Analysis of the expanded polyQ-associated proteins reveals marked enrichment of …

Lim Protein Ajuba Associates With The Rpa Complex Through Direct Cell Cycle-Dependent Interaction With The Rpa70 Subunit, Sandy Fowler, Pascal Maguin, Sampada Kalan, Diego Loayza

Publications and Research

DNA damage response pathways are essential for genome stability and cell survival. Specifically, the ATR kinase is activated by DNA replication stress. An early event in this activation is the recruitment and phosphorylation of RPA, a single stranded DNA binding complex composed of three subunits, RPA70, RPA32 and RPA14. We have previously shown that the LIM protein Ajuba associates with RPA, and that depletion of Ajuba leads to potent activation of ATR. In this study, we provide evidence that the Ajuba-RPA interaction occurs through direct protein contact with RPA70, and that their association is cell cycle-regulated and is reduced upon …

Aβ42 Protofibrils Interact With, And Are Trafficked Through, Microglial-Derived Microvesicles, Lisa Gouwens, Mudar Ismail, Victoria Rogers, Nathan Zeller, Evan Garrad, Fatima Amtashar, Nyasha Makoni, David Osborn, Michael Nichols

Chemistry & Biochemistry Faculty Works

Microvesicles (MVs) and exosomes comprise a class of cell-secreted particles termed extracellular vesicles (EVs). These cargo-holding vesicles mediate cell-to-cell communication and have recently been implicated in neurodegenerative diseases such as Alzheimer’s disease (AD). The two types of EVs are distinguished by the mechanism of cell release and their size, with the smaller exosomes and the larger MVs ranging from 30 to 100 nm and 100 nm to 1 μm in diameter, respectively. MV numbers are increased in AD and appear to interact with amyloid-β peptide (Aβ), the primary protein component of the neuritic plaques in the AD brain. Because microglial …