Life Sciences Commons^™

Morphological And Genetic Changes Induced By Excess Zn In Roots Of Medicago Truncatula A17 And A Zn Accumulating Mutant, Ricky W. Lewis, Guiliang Tang, David H. Mcnear

Plant and Soil Sciences Faculty Publications

BACKGROUND: Nutrient fluxes associated with legume-rhizobia symbioses are poorly understood and little is known regarding the influence of abiotic stresses on development and maintenance of N-fixing nodules and root system architecture (RSA). We examined effects of Zn on nodule development and structure, root architecture, and expression of nodulation-related miRNAs in Medicago truncatula and the mutant, raz (requires additional Zn).

FINDINGS: Excess Zn increased root and shoot associated Zn in both genotypes, however, raz plants had lower root associated Zn than WT plants. Roots of raz plants exposed to excess Zn had less volume, surface area, and total length compared to …

Microrna Signature In Alcoholic Liver Disease, Shashi Bala, Gyongyi Szabo

Gyongyi Szabo

Alcoholic liver disease (ALD) is a major global health problem. Chronic alcohol use results in inflammation and fatty liver, and in some cases, it leads to fibrosis and cirrhosis or hepatocellular carcinoma. Increased proinflammatory cytokines, particularly TNF alpha, play a central role in the pathogenesis of ALD. TNF alpha is tightly regulated at transcriptional and posttranscriptional levels. Recently, microRNAs (miRNAs) have been shown to modulate gene functions. The role of miRNAs in ALD is getting attention, and recent studies suggest that alcohol modulates miRNAs. Recently, we showed that alcohol induces miR-155 expression both in vitro (RAW 264.7 macrophage) and in …

Advanced Molecular Biologic Techniques In Toxicologic Disease, Jeanine Ward, Gyongyi Szabo, David Mcmanus, Edward Boyer

Gyongyi Szabo

The advancement of molecular biologic techniques and their capabilities to answer questions pertaining to mechanisms of pathophysiologic events have greatly expanded over the past few years. In particular, these opportunities have provided researchers and clinicians alike the framework from with which to answer clinical questions not amenable for elucidation using previous, more antiquated methods. Utilizing extremely small molecules, namely microRNA, DNA, protein, and nanoparticles, we discuss the background and utility of these approaches to the progressive, practicing physician. Finally, we consider the application of these tools employed as future bedside point of care tests, aiding in the ultimate goal of …

Plasma Microrna Profiles Distinguish Lethal Injury In Acetaminophen Toxicity: A Research Study, Jeanine Ward, Shashi Bala, Jan Petrasek, Gyongyi Szabo

Gyongyi Szabo

AIM: To investigate plasma microRNA (miRNA) profiles indicative of hepatotoxicity in the setting of lethal acetaminophen (APAP) toxicity in mice. METHODS: Using plasma from APAP poisoned mice, either lethally (500 mg/kg) or sublethally (150 mg/kg) dosed, we screened commercially available murine microRNA libraries (SABiosciences, Qiagen Sciences, MD) to evaluate for unique miRNA profiles between these two dosing parameters. RESULTS: We distinguished numerous, unique plasma miRNAs both up- and downregulated in lethally compared to sublethally dosed mice. Of note, many of the greatest up- and downregulated miRNAs, namely 574-5 p, 466 g, 466 f-3p, 375, 29 c, and 148 a, have …

Circulating Micrornas In Exosomes Indicate Hepatocyte Injury And Inflammation In Alcoholic, Drug-Induced, And Inflammatory Liver Diseases, Shashi Bala, Jan Petrasek, Shiv Mundkur, Donna Catalano, Ivan Levin, Jeanine Ward, Hawau Alao, Karen Kodys, Gyongyi Szabo

Gyongyi Szabo

MicroRNAs are fine tuners of diverse biological responses and are expressed in various cell types of the liver. Here we hypothesized that circulating microRNAs (miRNAs) may serve as biomarkers of liver damage and inflammation. We studied miRNA-122, which is abundant in hepatocytes, and miR-155, -146a, and -125b, which regulate inflammation in immune cells in mouse models of alcoholic liver disease (ALD), drug (acetaminophen, APAP)-induced liver injury (DILI), and Toll-like receptor (TLR) 9+4 ligand-induced inflammatory cell-mediated liver damage. We found that serum/plasma miR-122 correlated with alanine aminotransferase (ALT) increases in the liver damage caused by alcohol, APAP, and TLR9 (CpG)+4 (LPS) …

Increased Microrna-155 Expression In The Serum And Peripheral Monocytes In Chronic Hcv Infection, Shashi Bala, Yaphet Tilahun, Odette Taha, Hawau Alao, Karen Kodys, Donna Catalano, Gyongyi Szabo

Gyongyi Szabo

BACKGROUND: Hepatitis C Virus (HCV), a single stranded RNA virus, affects millions of people worldwide and leads to chronic infection characterized by chronic inflammation in the liver and in peripheral immune cells. Chronic liver inflammation leads to progressive liver damage. MicroRNAs (miRNA) regulate inflammation (miR-155, -146a and -125b) as well as hepatocyte function (miR-122). METHODS: Here we hypothesized that microRNAs are dysregulated in chronic HCV infection. We examined miRNAs in the circulation and in peripheral monocytes of patients with chronic HCV infection to evaluate if specific miRNA expression correlated with HCV infection. RESULTS: We found that monocytes from chronic HCV …

Using Next Generation Sequencing (Ngs) To Identify And Predict Micrornas (Mirnas) Potentially Affecting Schizophrenia And Bipolar Disorder, Vernell Williamson

Theses and Dissertations

The last decade has seen considerable research focusing on understanding the factors underlying schizophrenia and bipolar disorder. A major challenge encountered in studying these disorders, however, has been the contribution of genetic, or etiological, heterogeneity to the so-called “missing heritability” [1-6]. Further, recent successes of large-scale genome-wide association studies (GWAS) have nonetheless seen only limited advancements in the delineation of the specific roles of implicated genes in disease pathophysiology. The study of microRNAs (miRNAs), given their ability to alter the transcription of hundreds of targeted genes, has the potential to expand our understanding of how certain genes relate to schizophrenia …

Global Approaches To The Role Of Mirnas In Drug-Induced Changes In Gene Expression, Jodi E. Eipper-Mains, Betty A. Eipper, Richard E. Mains

UCHC Articles - Research

Neurons modulate gene expression with subcellular precision through excitation-coupled local protein synthesis, a process that is regulated in part through the involvement of microRNAs (miRNAs), a class of small non-coding RNAs. The biosynthesis of miRNAs is reviewed, with special emphasis on miRNA families, the subcellular localization of specific miRNAs in neurons, and their potential roles in the response to drugs of abuse. For over a decade, DNA microarrays have dominated genome-wide gene expression studies, revealing widespread effects of drug exposure on neuronal gene expression. We review a number of recent studies that explore the emerging role of miRNAs in the …

The Path To Microrna Therapeutics In Psychiatric And Neurodegenerative Disorders, Anthony W. S. Chan, Jannet Kocerha

Jannet Kocerha

The microRNA (miRNA) class of non-coding RNAs exhibit a diverse range of regulatory roles in neuronal functions that are conserved from lower vertebrates to primates. Disruption of miRNA expression has compellingly been linked to pathogenesis in neuropsychiatric and neurodegenerative disorders, such as schizophrenia, Alzheimer’s disease, and autism. The list of transcript targets governed by a single miRNA provide a molecular paradigm applicable for therapeutic intervention. Indeed, reports have shown that specific manipulation of a miRNA in cell or animal models can significantly alter phenotypes linked with neurological disease. Here, we review how a diverse range of biological systems, including Drosophila, …

The Mir-51 Family Of Micrornas Functions In Diverse Regulatory Pathways In Caenorhbditis Elegans, Allison L. Abbott, John L. Brenner, Benedict J. Kemp

Biological Sciences Faculty Research and Publications

The mir-51 family of microRNAs (miRNAs) in C. elegans are part of the deeply conserved miR-99/100 family. While loss of all six family members (mir-51-56) in C. elegans results in embryonic lethality, loss of individual mir-51 family members results in a suppression of retarded developmental timing defects associated with the loss of alg-1. The mechanism of this suppression of developmental timing defects is unknown. To address this, we characterized the function of the mir-51 family in the developmental timing pathway. We performed genetic analysis and determined that mir-51 family members regulate the developmental timing pathway in the L2 stage …

Genetic Engineering Of Turfgrass For Enhanced Performance Under Environmental Stress, Man Zhou

All Dissertations

Turfgrass species are agriculturally and economically important perennial crops that are susceptible to biotic stress (e.g. fungal pathogens) and abiotic stress (e.g. salinity and drought). Every year, environmental stress significantly influences turfgrass quality and production causing economic loss globally. My research explores the feasibility of using two novel transgenes - Penaeidin4-1 (Pen4-1) from the shrimp, Litopenaeus setiferus, and microRNA319a (miR319a) from the rice, Oryza sativa, to genetically engineer turfgrass for enhanced tolerance to environmental stress.
The antimicrobial peptide - Pen4-1 has been reported to possess in vitro antifungal and antibacterial activities against various economically important pathogens. In this study, two …

Genetic Identification Of Development Pathways Regulated By Conserved Micrornas In Caenorhabditis Elegans, John L. Brenner

Dissertations (1934 -)

microRNAs (miRNAs) are approximately 22 nucleotide non-coding RNAs that function to repress genes by binding to complementary sites in target mRNAs and play critical roles in development and disease. It is predicted that more than 60% of human genes are regulated by miRNAs, however, little is known about the individual functions of miRNAs. I used the nematode worm, Caenorhabditis elegans, as a model to identify developmental processes and pathways regulated by conserved miRNAs. Genetic examination of miRNA function is hindered by lack of obvious phenotypes attributed to loss of individual miRNA genes. Phenotypes attributable to loss of individual miRNA genes …

Microrna-Regulated, Systemically Delivered Raav9: A Step Closer To Cns-Restricted Transgene Expression, Jun Xie, Qing Xie, Hongwei Zhang, Stefan L. Ameres, Jui-Hung Hung, Qin Su, Ran He, Xin Mu, Seemin Seher Ahmed, Soyeon Park, Hiroki Kato, Chengjian Li, Christian Mueller, Craig C. Mello, Zhiping Weng, Terence R. Flotte, Phillip D. Zamore, Guangping Gao

Christian Mueller

Recombinant adeno-associated viruses (rAAVs) that can cross the blood-brain-barrier and achieve efficient and stable transvascular gene transfer to the central nervous system (CNS) hold significant promise for treating CNS disorders. However, following intravascular delivery, these vectors also target liver, heart, skeletal muscle, and other tissues, which may cause untoward effects. To circumvent this, we used tissue-specific, endogenous microRNAs (miRNAs) to repress rAAV expression outside the CNS, by engineering perfectly complementary miRNA-binding sites into the rAAV9 genome. This approach allowed simultaneous multi-tissue regulation and CNS-directed stable transgene expression without detectably perturbing the endogenous miRNA pathway. Regulation of rAAV expression by miRNA …

Sustained Mirna-Mediated Knockdown Of Mutant Aat With Simultaneous Augmentation Of Wild-Type Aat Has Minimal Effect On Global Liver Mirna Profiles, Christian Mueller, Qiushi Tang, Alisha Gruntman, Keith S. Blomenkamp, Jeffrey H. Teckman, Lina Song, Phillip D. Zamore, Terence R. Flotte

Christian Mueller

Alpha-1 antitrypsin (AAT) deficiency can exhibit two pathologic states: a lung disease that is primarily due to the loss of AAT's antiprotease function, and a liver disease resulting from a toxic gain-of-function of the PiZ-AAT (Z-AAT) mutant protein. We have developed several recombinant adeno-associated virus (rAAV) vectors that incorporate microRNA (miRNA) sequences targeting the AAT gene while also driving the expression of miRNA-resistant wild-type AAT-PiM (M-AAT) gene, thus achieving concomitant Z-AAT knockdown in the liver and increased expression of M-AAT. Transgenic mice expressing the human PiZ allele treated with dual-function rAAV9 vectors showed that serum PiZ was stably and persistently …

Dimerization And Heme Binding Are Conserved In Amphibian And Starfish Homologues Of The Microrna Processing Protein Dgcr8., Rachel Senturia, Arthur Laganowsky, Ian Barr, Brooke D. Scheidemantle, Feng Guo

Natural Sciences and Mathematics | Faculty Scholarship

Human DiGeorge Critical Region 8 (DGCR8) is an essential microRNA (miRNA) processing factor that is activated via direct interaction with Fe(III) heme. In order for DGCR8 to bind heme, it must dimerize using a dimerization domain embedded within its heme-binding domain (HBD). We previously reported a crystal structure of the dimerization domain from human DGCR8, which demonstrated how dimerization results in the formation of a surface important for association with heme. Here, in an attempt to crystallize the HBD, we search for DGCR8 homologues and show that DGCR8 from Patiria miniata (bat star) also binds heme. The extinction coefficients (ε) …