The Role Of The Pituitary-Adrenal Axis In G-Csf Therapy After Neonatal Hypoxia-Ischemia, Mélissa Stéphanie Charles

Loma Linda University Electronic Theses, Dissertations & Projects

Several reports indicate that the activity of the hypothalamic-pituitary-adrenal axis (HPA) as measured by the increased level of adrenocorticotropic hormone (ACTH), and corticosterone is increased after a brain insult. These hormones are the effectors secreted respectively by the pituitary and adrenal glands. It has been shown that the down-regulation of corticosterone levels can improve detrimental outcomes associated with ischemic brain injuries. Neonatal hypoxia-ischemia (HI) is a devastating perinatal event with a grim prognosis and limited therapeutic strategies. In recent studies, granulocyte-colony stimulating factor (G-CSF) has shown promise in neonatal HI investigations by improving neuromotor function and reducing apoptosis in the …

Examination Of The Chromatin Structure Of Xlr3b Using The Chromosome Conformation Capture Assay, Sarah Elise Conderino

Honors Scholar Theses

Imprinted genes contain epigenetic modifications that influence expression patterns based on parent-of-origin. Recent studies have shown that imprinted genes contribute to numerous human diseases and disorders. Xlr3b, an imprinted gene on the X chromosome, has been implicated in social and behavioral deficits characteristic of disorders such as Turner syndrome and autism. The imprinting mechanism of this gene is still unknown, and this study analyzed the native chromatin structure of Xlr3b through the chromosome conformation capture assay to determine if there are any long-range interactions that regulate the expression of this gene. Brain tissue from a mouse model of Turner …

Mutation And Complementation Of A Cellulose Synthase (Cesa) Gene, Ahmed Y. El-Araby

Senior Honors Projects

Cellulose is a carbohydrate polymer that is composed of repeating glucose subunits. Being the most abundant organic compound in the biosphere and comprising a large percentage of all plant biomass, cellulose is extremely plentiful and has a significant role in nature. Cellulose is present in plant cell walls, in commercial products such as those made from wood or cotton, and is of interest to the biofuel industry as a potential alternative fuel source. Although indigestible by humans, cellulose is nutritionally valuable, serving as a dietary fiber. Because of its ubiquity and importance in many areas, studying cellulose will prove to …

Fluorescence-Based Reporter For Gauging Cyclic Di-Gmp Levels In Pseudomonas Aeruginosa, Morten T. Rybtke, Bradley R. Borlee, Keiji Murakami, Yasuhiko Irie, Morten Hentzer, Thomas E. Nielsen, Michael Givskov, Matthew R. Parsek, Tim Tolker-Nielsen

Biology Faculty Publications

The increased tolerance toward the host immune system and antibiotics displayed by biofilm-forming Pseudomonas aeruginosa and other bacteria in chronic infections such as cystic fibrosis bronchopneumonia is of major concern. Targeting of biofilm formation is believed to be a key aspect in the development of novel antipathogenic drugs that can augment the effect of classic antibiotics by decreasing antimicrobial tolerance. The second messenger cyclic di-GMP is a positive regulator of biofilm formation, and cyclic di-GMP signaling is now regarded as a potential target for the development of antipathogenic compounds. Here we describe the development of fluorescent monitors that can gauge …

Widespread Diversity In African Toads (Anura: Amietophrynus), Nancy P. Conkey ^, Eli Greenbaum *

COURI Symposium Abstracts, Spring 2012

No abstract provided.

Neurodegeneration - A Means To An End, Amit Singh

Biology Faculty Publications

Cell death, a global phenomenon found throughout the animal kingdom, is a mechanism to maintain tissue homeostasis and for adaptation to changes in the environment [1,2]. Millions of cells die in our body daily- they succumb to stress and commit suicide by a mechanism referred to as cell death or apoptosis [2-4]. Under normal conditions cells are continuously replaced by new cells from the stemor progenitor- cells. For example, an optimum balance in shedding of dead cells from the skin and their replenishment by new ones maintain our health and hygiene. In this context, apoptosis is a mechanism to eliminate …

Pseudoscorpion Mitochondria Show Rearranged Genes And Genome-Wide Reductions Of Rna Gene Sizes And Inferred Structures, Yet Typical Nucleotide Composition Bias, Sergey Ovchinnikov, Susan E. Masta

Biology Faculty Publications and Presentations

Pseudoscorpions are chelicerates and have historically been viewed as being most closely related to solifuges, harvestmen, and scorpions. No mitochondrial genomes of pseudoscorpions have been published, but the mitochondrial genomes of some lineages of Chelicerata possess unusual features, including short rRNA genes and tRNA genes that lack sequence to encode arms of the canonical cloverleaf-shaped tRNA. Additionally, some chelicerates possess an atypical guanine-thymine nucleotide bias on the major coding strand of their mitochondrial genomes.

We sequenced the mitochondrial genomes of two divergent taxa from the chelicerate order Pseudoscorpiones. We find that these genomes possess unusually short tRNA genes that do …

Pten Regulation Of Local And Long-Range Connections In Mouse Auditory Cortex, Qiaojie Xiong, Hysell V. Oviedo, Lloyd C. Trotman, Anthony M. Zador

Publications and Research

Autism spectrum disorders (ASDs) are highly heritable developmental disorders caused by a heterogeneous collection of genetic lesions. Here we use a mouse model to study the effect on cortical connectivity of disrupting the ASD candidate gene PTEN (phosphatase and tensin homolog deleted on chromosome 10). Through Cre-mediated recombination, we conditionally knocked out PTEN expression in a subset of auditory cortical neurons. Analysis of long-range connectivity using channelrhodopsin-2 revealed that the strength of synaptic inputs from both the contralateral auditory cortex and from the thalamus onto PTEN-cko neurons was enhanced compared with nearby neurons with normal PTEN expression. Laser-scanning photostimulation showed …

Desert Hedgehog Is A Mammal-Specific Gene Expressed During Testicular And Ovarian Development In A Marsupial, William A. O'Hara

Master's Theses

Desert hedgehog (DHH) belongs to the hedgehog gene family that act as secreted intercellular signal transducers. DHH is an essential morphogen for normal testicular development and function in both mice and humans but is not present in the avian lineage. Like other hedgehog proteins, DHH signals through the patched (PTCH) receptors 1 and 2. Here we examine the expression and protein distribution of DHH, PTCH1 and PTCH2 in the developing testes of a marsupial mammal (the tammar wallaby) to determine whether DHH signalling is a conserved factor in gonadal development in all therian mammals.

Tumor Suppression By Cell Competition Through Regulation Of The Hippo Pathway, Chiao-Lin Chen, Molly C. Schroeder, Madhuri Kango-Singh, Chunyao Tao, Georg Halder

Biology Faculty Publications

Homeostatic mechanisms can eliminate abnormal cells to prevent diseases such as cancer. However, the underlying mechanisms of this surveillance are poorly understood. Here we investigated how clones of cells mutant for the neoplastic tumor suppressor gene scribble (scrib) are eliminated from Drosophila imaginal discs. When all cells in imaginal discs are mutant for scrib, they hyperactivate the Hippo pathway effector Yorkie (Yki), which drives growth of the discs into large neoplastic masses. Strikingly, when discs also contain normal cells, the scrib− cells do not overproliferate and eventually undergo apoptosis through JNK-dependent mechanisms. However, induction of apoptosis does …

Contribution Of The Infection-Associated Complement Regulator-Acquiring Surface Protein 4 (Erpc) To Complement Resistance Of Borrelia Burgdorferi, Claudia Hammerschmidt, Teresia Hallström, Christine Skerka, Reinhard Wallich, Brian Stevenson, Peter F Zipfel, Peter Kraiczy

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Borrelia burgdorferi evades complement-mediated killing by interacting with complement regulators through distinct complement regulator-acquiring surface proteins (CRASPs). Here, we extend our analyses to the contribution of CRASP-4 in mediating complement resistance of B. burgdorferi and its interaction with human complement regulators. CRASP-4 (also known as ErpC) was immobilized onto magnetic beads and used to capture proteins from human serum. Following Western blotting, factor H (CFH), CFH-related protein 1 (CFHR1), CFHR2, and CFHR5 were identified as ligands of CRASP-4. To analyze the impact of native CRASP-4 on mediating survival of serum-sensitive cells in human serum, a B. garinii strain was generated …

Development And Validation Of A Novel Reporter Assay For Human Papillomavirus Type 16 Late Gene Expression, Beatrice Orru, Ciaran Cunniffe, Fergus Ryan, Stefan Schwartz

Articles

To facilitate the investigations of HPV-16 late gene expression HPV-16 reporter plasmids were generated using previously described sub-genomic HPV-16 plasmids, named pBEL and pBELM, that, similar to the full viral genome, produce primarily HPV-16 early mRNAs and very little, if any, late mRNAs in cervical cancer cells. The HPV-16 late L1 gene was replaced by the chloramphenicol acetyltransferase (CAT) reporter gene, or green fluorescent protein (GFP), preceded by the poliovirus internal ribosome entry site (IRES). Results show that the reporter genes mimic the expression of L1 from these plasmids. For example, overexpression of adenovirus E4orf4 protein (E4orf4), polypyrimidine tract binding …

A Shared Gene Expression Signature In Mouse Models Of Ebv-Associated And Non-Ebv-Associated Burkitt Lymphoma, Kathryn T. Bieging, Kamonwan Fish, Subbarao Bondada, Richard Longnecker

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The link between EBV infection and Burkitt lymphoma (BL) is strong, but the mechanism underlying that link has been elusive. We have developed a mouse model for EBV-associated BL in which LMP2A, an EBV latency protein, and MYC are expressed in B cells. Our model has demonstrated the ability of LMP2A to accelerate tumor onset, increase spleen size, and bypass p53 inactivation. Here we describe the results of total gene expression analysis of tumor and pretumor B cells from our transgenic mouse model. Although we see many phenotypic differences and changes in gene expression in pretumor B cells, the transcriptional …

Characterization Of A Novel Gef Kiaa1362, Emily Roach

Honors Capstones

Capstone submitted as a graduation requirement for the BSU Honors Program.

Protein Trap Lines Of Drosophila To Demonstrate Spatio-Temporal Localization Of Proteins In An Undergraduate Lab, Oorvashi Roy Puli, Amit Singh

Biology Faculty Publications

The objective of this teaching note is to generate a laboratory exercise, which allows students to get a hands-on experience of a cell biology technique. The short duration of the laboratory classes is the biggest challenge with the development of a cell biology lab for an undergraduate curriculum. Therefore, it is necessary to design a laboratory exercise that enables the students to carry out cell biological assays in the desired time. This laboratory exercise focuses on tracking protein expression levels along a spatial (space) and temporal (time) axis in developing Drosophila melanogaster organ primordium. Here we use the protein trap …

Exploring The Effects Of Hypoxia On Sulfate Reducing Anaerobes, Annaliese K. Jones

Senior Honors Projects

Exploring the Effects of Hypoxia on Sulfate Reducing Anaerobes

Annaliese K. Jones

Sponsor: Bethany Jenkins, Cell and Molecular Biology

As a student about to graduate with a degree in Biological Sciences, I find myself faced with the need to find my own independent research interests and scientific voice. As a result of my interests in the fields of both microbiology and ecology, I am drawn to questions surrounding the role and behavior of microorganisms in the environment. With climate change being an issue capturing the attention of a large portion of the scientific community, I have chosen to focus my …

Quantitative Comparison Of Cis-Regulatory Element (Cre) Activities In Transgenic Drosophila Melanogaster, William A. Rogers, Thomas M. Williams

Biology Faculty Publications

Gene expression patterns are specified by cis-regulatory element (CRE) sequences, which are also called enhancers or cis-regulatory modules. A typical CRE possesses an arrangement of binding sites for several transcription factor proteins that confer a regulatory logic specifying when, where, and at what level the regulated gene(s) is expressed. The full set of CREs within an animal genome encodes the organism′s program for development¹, and empirical as well as theoretical studies indicate that mutations in CREs played a prominent role in morphological evolution^2-4. Moreover, human genome wide association studies indicate that genetic variation in CREs …

Identification Of Factors Involved In Dna Methylation Of Cpg-Island-Promoters, Yan Zhang

Dissertations and Theses (Open Access)

Repression of many tumor suppressor genes (TSGs) in cancer is mediated by aberrantly increased DNA methylation levels at promoter CpG islands (CGI). About one-fourth of empirically defined human promoters are surrounded by or contain clustered repetitive elements. It was previously observed that a sharp transition of methylation occurs between highly methylated repetitive elements (SINE or LINE) and unmethylated CGI-promoters (e.g. P16, VHL, CDH and RIL) in normal tissues. The functions that lead to increased CGI methylation in cancer remain poorly understood. We propose that CGI-promoters contain cis-elements for triggering de novo DNA methylation. In the first part of our project, …

Role Of The Gcn5 Histone Acetyltransferase In Spinocerebellar Ataxia Type 7 And In Immature Neurons, Yi Chun Chen

Dissertations and Theses (Open Access)

Spinocerebellar Ataxia type 7 (SCA7) is a neurodegenerative disease caused by expansion of a CAG repeat encoding a polyglutamine tract in ATXN7, a component of the SAGA histone acetyltransferase (HAT) complex. Previous studies provided conflicting evidence regarding the effects of polyQ-ATXN7 on the activity of Gcn5, the HAT catalytic subunit of SAGA. Here I showed that reducing Gcn5 expression accelerates both cerebellar and retinal degeneration in a mouse model of SCA7. Deletion of Gcn5 in Purkinje cells in mice expressing wild type Atxn7, however, causes only mild ataxia and does not lead to the early lethality observed in SCA7 mice. …

Comparison Of Four Chip-Seq Analytical Algorithms Using Rice Endosperm H3k27 Trimethylation Profiling Data., Brandon M. Malone, Feng Tan, Susan M. Bridges, Zhaohua Peng

BCoE Publications

Chromatin immunoprecipitation coupled with high throughput DNA Sequencing (ChIP-Seq) has emerged as a powerful tool for genome wide profiling of the binding sites of proteins associated with DNA such as histones and transcription factors. However, no peak calling program has gained consensus acceptance by the scientific community as the preferred tool for ChIP-Seq data analysis. Analyzing the large data sets generated by ChIP-Seq studies remains highly challenging for most molecular biology laboratories.Here we profile H3K27me3 enrichment sites in rice young endosperm using the ChIP-Seq approach and analyze the data using four peak calling algorithms (FindPeaks, PeakSeq, USeq, and MACS). Comparison …

Activation Of Jnk Signaling Mediates Amyloid-Ss- Dependent Cell Death, Meghana Tare, Rohan Modi, Jaison Nainaparampil, Oorvashi Roy Puli, Shimpi Bedi, Pedro Fernandez-Funez, Madhuri Kango-Singh, Amit Singh

Biology Faculty Publications

Background: Alzheimer's disease (AD) is an age related progressive neurodegenerative disorder. One of the reasons for Alzheimer's neuropathology is the generation of large aggregates of Aß42 that are toxic in nature and induce oxidative stress, aberrant signaling and many other cellular alterations that trigger neuronal cell death. However, the exact mechanisms leading to cell death are not clearly understood.

Methodology/Principal Findings: We employed a Drosophila eye model of AD to study how Aß42 causes cell death. Misexpression of higher levels of Aß42 in the differentiating photoreceptors of fly retina rapidly induced aberrant cellular phenotypes and cell death. We found that …

Combination Of Virb Binding Site Mutations To Evaluate Collective Impact On Icsp Promoter Activity In Shigella Flexneri, Pashtana Usufuzy, Juan C. Duhart, Maria I. Castellanos, Helen Wing

Undergraduate Research Opportunities Program (UROP)

Shigella flexneri is a gram-negative, invasive bacterial pathogen that afflicts the human colonic epithelium, causing shigellosis, an illness triggering severe dysentery. The World Health Organization cites the disease burden of shigellosis near 90 million episodes and 108,000 deaths per year.

The motility and spread of Shigella is modulated by icsP, a virulence gene. The transcription factor VirB positively regulates many virulence genes encoded by the Shigella virulence plasmid. Two distal binding sites of VirB have been shown to regulate the promoter activity of icsP, despite their location of more than 1 kb upstream of the transcription start site. Five VirB …

Evaluating Species Responses To Climate Change Using Ecological Niche Modeling And Genetic Data, Jeanette Perry

Undergraduate Research Opportunities Program (UROP)

The current and projected future warming trends together with degradation of habitats throughout much of the Great Basin and Columbian Plateau represent real threats to many species occupying these regions. If we can determine the impacts of past climatic changes on the distribution of species, we can obtain a better understanding of the future impacts of projected climatic trends on many species in these regions. My results with the Great Basin Pocket Mouse (Perognathus parvus) may be relevant to conservation ecologists and resource managers attempting to protect several Endangered Species Act candidates, such as the pygmy cottontail (Brachylagus idahoensis). I …

Gata-Family Transcription Factors In Magnaporthe Oryzae, Cristian F. Quispe

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

The filamentous fungus, Magnaporthe oryzae, responsible for blast rice disease, destroys around 10-30% of the rice crop annually. Infection begins when the specialized infection structure, the appressorium, generates enormous internal turgor pressure through the accumulation of glycerol. This turgor acts on a penetration peg emerging at the base of the cell, causing it to breach the leaf surface allowing its infection.

The enzyme trehalose-6- phosphate synthase (Tps1) is a central regulator of the transition from appressorium development to infectious hyphal growth. In the first chapter we show that initiation of rice blast disease requires a regulatory mechanism involving an …

Downregulation Of Pax2 Suppresses Ovarian Cancer Cell Growth, Huijuan Song

Dissertations and Theses (Open Access)

PAX2 is one of nine PAX genes regulating tissue development and cellular differentiation in embryos. PAX2 promotes cell proliferation, oncogenic transformation, cell-lineage specification, migration, and survival. Unattenuated PAX2 has been found in several cancer types. We therefore sought to elucidate the role of PAX2 in ovarian carcinomas. We found that PAX2 was expressed in low-grade serous, clear cell, endometrioid and mucinous cell ovarian carcinomas, which are relatively chemoresistant compared to high grade serous ovarian carcinomas. Four ovarian cancer cell lines, RMUGL (mucinous), TOV21G (clear cell), MDAH-2774 (endometrioid) and IGROV1 (endometrioid), which express high-levels of PAX2, were used to study the …

Mechanical Test Methods For Assessing Porcine Carotid And Uterine Artery Burst Pressure Following Ex Vivo Ultrasonic Ligature Seal And Transection, Carissa M. Krane, Margaret Pinnell, Courtney Gardner, Mercedes Thompson, James Coleman, Robert Wilkens

Biology Faculty Publications

A test method was developed to identify those variables important for assessing the performance of ultrasonic surgical devices in ex vivo ligature sealing of porcine carotid and uterine arteries. Ruggedness testing using a small sample size in pilot experiments was conducted using a newly developed test method in an effort to assess the usefulness of this methodology and to identify test variables that might warrant further testing. The development of this test method included the use of a custom-designed prototypic tension device for load-controlled ex vivo vessel stretching during saline perfusion and subsequent seal and transection of porcine arteries with …

Role Of Phosphoinositide 3-Kinase – Akt Signaling Pathway In The Age-Related Cytokine Dysregulation In Splenic Macrophages Stimulated Via Tlr-2 Or Tlr-4 Receptors, Mosoka Papa Fallah, R. Lakshman Chelvarajan, Beth A. Garvy, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Age-associated defects in both B-lymphocytes and macrophages in elderly result in a reduction in the efficacy of vaccines to many Gram positive bacteria like Streptococcus pneumoniae. Splenic macrophages from aged mice have been shown to have a defect in production of pro-inflammatory cytokines (IL-6, IL-12, IL-1β, TNF-α) but exhibit increased production of IL-10 upon TLR4 ligation. Here we showed that aged macrophages demonstrate similar cytokine dysregulation phenotype upon stimulation with TLR2 ligands, or killed S. pneumoniae. We hypothesized that an age-associated increase in activity of phosphatidyl inositol 3-kinase (PI3K)-Akt signaling pathway may be playing a causal role in …

Recombination Phenotypes Of The Nci-60 Collection Of Human Cancer Cells, Dawn M. Stults, Michael W. Killen, Brent J. Shelton, Andrew J. Pierce

Microbiology, Immunology, and Molecular Genetics Faculty Publications

BACKGROUND: The NCI-60 is a collection of tumor cell lines derived from a variety of human adult cancer tissue types and is commonly used for genetic analysis and screening of potential chemotherapeutic agents. We wanted to understand the contributions of specific mechanisms of genomic instability to the etiology of cancers represented by the NCI-60.

RESULTS: We screened the NCI-60 for dysregulated homologous recombination by using the gene cluster instability (GCI) assay we pioneered, and for defects in base excision repair by sensitivity to 5-hydroxymethyl-2'-deoxyuridine (hmdUrd). We identified subsets of the NCI-60 lines that either displayed the characteristic molecular signature of …

The Role Of Historical And Contemporary Processes On Phylogeographic Structure And Genetic Diversity In The Northern Cardinal, Cardinalis Cardinalis, Brian T. Smith, Patricia Escalante, Blanca E. Hernandez-Banos, Adolfo G. Navarro-Siguenza, Sievert Rohwer, John Klicka

Ornithology Program (HRC)

Background

Earth history events such as climate change are believed to have played a major role in shaping patterns of genetic structure and diversity in species. However, there is a lag between the time of historical events and the collection of present-day samples that are used to infer contemporary population structure. During this lag phase contemporary processes such as dispersal or non-random mating can erase or reinforce population differences generated by historical events. In this study we evaluate the role of both historical and contemporary processes on the phylogeography of a widespread North American songbird, the Northern Cardinal, Cardinalis cardinalis …

Design Of A Factorial Experiment With Randomization Restrictions To Assess Medical Device Performance On Vascular Tissue, Wiebke Diestelkamp, Carissa M. Krane, Margaret Pinnell

Biology Faculty Publications

Background: Energy-based surgical scalpels are designed to efficiently transect and seal blood vessels using thermal energy to promote protein denaturation and coagulation. Assessment and design improvement of ultrasonic scalpel performance relies on both in vivo and ex vivo testing. The objective of this work was to design and implement a robust, experimental test matrix with randomization restrictions and predictive statistical power, which allowed for identification of those experimental variables that may affect the quality of the seal obtained ex vivo.

Methods: The design of the experiment included three factors: temperature (two levels); the type of solution used to perfuse the …