Life Sciences Commons^™

Adjusting For Gene-Specific Covariates To Improve Rna-Seq Analysis, Hyeongseon Jeon, Kyu-Sang Lim, Yet Nguyen, Dan Nettleton

Mathematics & Statistics Faculty Publications

Summary

This paper suggests a novel positive false discovery rate (pFDR) controlling method for testing gene-specific hypotheses using a gene-specific covariate variable, such as gene length. We suppose the null probability depends on the covariate variable. In this context, we propose a rejection rule that accounts for heterogeneity among tests by employing two distinct types of null probabilities. We establish a pFDR estimator for a given rejection rule by following Storey's q-value framework. A condition on a type 1 error posterior probability is provided that equivalently characterizes our rejection rule. We also present a suitable procedure for selecting a tuning …

Rnase Κ Promotes Robust Pirna Production By Generating 2',3'-Cyclic Phosphate-Containing Precursors, Megumi Shigematsu, Takuya Kawamura, Keisuke Morichika, Natsuko Izumi, Takashi Kiuchi, Shozo Honda, Venetia Pliatsika, Ryuma Matsubara, Isidore Rigoutsos, Susumu Katsuma, Yukihide Tomari, Yohei Kirino

Computational Medicine Center Faculty Papers

In animal germlines, PIWI proteins and the associated PIWI-interacting RNAs (piRNAs) protect genome integrity by silencing transposons. Here we report the extensive sequence and quantitative correlations between 2′,3′-cyclic phosphate-containing RNAs (cP-RNAs), identified using cP-RNA-seq, and piRNAs in the Bombyx germ cell line and mouse testes. The cP-RNAs containing 5′-phosphate (P-cP-RNAs) identified by P-cP-RNA-seq harbor highly consistent 5′-end positions as the piRNAs and are loaded onto PIWI protein, suggesting their direct utilization as piRNA precursors. We identified Bombyx RNase Kappa (BmRNase κ) as a mitochondria-associated endoribonuclease which produces cP-RNAs during piRNA biogenesis. BmRNase κ-depletion elevated transposon levels and disrupted a piRNA-mediated …

Structural Biology Of The Enterovirus Replication-Linked 5'-Cloverleaf Rna And Associated Virus Proteins, Steven M. Pascal, Ravindranath Garimella, Meghan S. Warden, Komala Ponniah

Chemistry & Biochemistry Faculty Publications

Although enteroviruses are associated with a wide variety of diseases and conditions, their mode of replication is well conserved. Their genome is carried as a single, positive-sense RNA strand. At the 5′ end of the strand is an approximately 90-nucleotide self-complementary region called the 5′ cloverleaf, or the oriL. This noncoding region serves as a platform upon which host and virus proteins, including the 3B, 3C, and 3D virus proteins, assemble in order to initiate replication of a negative-sense RNA strand. The negative strand in turn serves as a template for synthesis of multiple positive-sense RNA strands. Building on structural …

Genome-Wide Identification Of Short 2',3'-Cyclic Phosphate-Containing Rnas And Their Regulation In Aging., Megumi Shigematsu, Keisuke Morichika, Takuya Kawamura, Shozo Honda, Yohei Kirino

Computational Medicine Center Faculty Papers

RNA molecules generated by ribonuclease cleavage sometimes harbor a 2',3'-cyclic phosphate (cP) at their 3'-ends. Those cP-containing RNAs (cP-RNAs) form a hidden layer of transcriptome because standard RNA-seq cannot capture them as a result of cP's prevention of an adapter ligation reaction. Here we provide genome-wide analyses of short cP-RNA transcriptome across multiple mouse tissues. Using cP-RNA-seq that can exclusively sequence cP-RNAs, we identified numerous novel cP-RNA species which are mainly derived from cytoplasmic tRNAs, mRNAs, and rRNAs. Determination of the processing sites of substrate RNAs for cP-RNA generation revealed highly-specific RNA cleavage events between cytidine and adenosine in cP-RNA …

Yeast Mitochondrial Protein Pet111p Binds Directly To Two Distinct Targets In Cox2 Mrna, Suggesting A Mechanism Of Translational Activation, Julia L Jones, Katharina B Hofmann, Andrew T Cowan, Dmitry Temiakov, Patrick Cramer, Michael Anikin

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

The genes in mitochondrial DNA code for essential subunits of the respiratory chain complexes. In yeast, expression of mitochondrial genes is controlled by a group of gene-specific translational activators encoded in the nucleus. These factors appear to be part of a regulatory system that enables concerted expression of the necessary genes from both nuclear and mitochondrial genomes to produce functional respiratory complexes. Many of the translational activators are believed to act on the 5'-untranslated regions of target mRNAs, but the molecular mechanisms involved in this regulation remain obscure. In this study, we used a combination of in vivo and in …

Conformational Flexibility In The Enterovirus Rna Replication Platform, Meghan S. Warden, Kai Cai, Gabriel Cornilescu, Jordan E. Burke, Komala Ponniah, Samuel E. Butcher, Steven M. Pascal

Chemistry & Biochemistry Faculty Publications

A presumed RNA cloverleaf (5′CL), located at the 5′-most end of the noncoding region of the enterovirus genome, is the primary established site for initiation of genomic replication. Stem–loop B (SLB) and stem–loop D (SLD), the two largest stem–loops within the 5′CL, serve as recognition sites for protein interactions that are essential for replication. Here we present the solution structure of rhinovirus serotype 14 5′CL using a combination of nuclear magnetic resonance spectroscopy and small-angle X-ray scattering. In the absence of magnesium, the structure adopts an open, somewhat extended conformation. In the presence of magnesium, the structure compacts, bringing SLB …

The Combinatorics Of The Foldings Of Rna, Katrina Teunis

Student Summer Scholars Manuscripts

RNA, much like DNA, is made up of four building blocks called nucleotides, Adenine, Guanine, Cytosine, and Uracil. These nucleotides form words that like to fold in on itself and bond together, each type of nucleotide bonding with only one other type of nucleotide. Therefore, order and number of nucleotides present will determine how many times the strand of RNA can fold. Using these guidelines, we considered what happens when we have only one bonding pair. Expanding on what was proven in "k-Foldability of Words” (2017), we were able to expand on the number of ways a word can fold …

The Activity Of The Serotonin Receptor 2c Is Regulated By Alternative Splicing, Stefan Stamm, Samuel B. Gruber, Alexander G. Rabchevsky, Ronald B. Emeson

Molecular and Cellular Biochemistry Faculty Publications

The central nervous system-specific serotonin receptor 2C (5HT2C) controls key physiological functions, such as food intake, anxiety, and motoneuron activity. Its deregulation is involved in depression, suicidal behavior, and spasticity, making it the target for antipsychotic drugs, appetite controlling substances, and possibly anti-spasm agents. Through alternative pre-mRNA splicing and RNA editing, the 5HT2C gene generates at least 33 mRNA isoforms encoding 25 proteins. The 5HT2C is a G-protein coupled receptor that signals through phospholipase C, influencing the expression of immediate/early genes like c-fos. Most 5HT2C isoforms show constitutive activity, i.e., signal without ligand binding. The constitutive activity of 5HT2C is …

In Situ Capture Of Chromatin Interactions By Biotinylated Dcas9., Xin Liu, Yuannyu Zhang, Yong Chen, Mushan Li, Feng Zhou, Kailong Li, Hui Cao, Min Ni, Yuxuan Liu, Zhimin Gu, Kathryn E Dickerson, Shiqi Xie, Gary C Hon, Zhenyu Xuan, Michael Q Zhang, Zhen Shao, Jian Xu

Faculty Scholarship for the College of Science & Mathematics

Cis-regulatory elements (CREs) are commonly recognized by correlative chromatin features, yet the molecular composition of the vast majority of CREs in chromatin remains unknown. Here, we describe a CRISPR affinity purification in situ of regulatory elements (CAPTURE) approach to unbiasedly identify locus-specific chromatin-regulating protein complexes and long-range DNA interactions. Using an in vivo biotinylated nuclease-deficient Cas9 protein and sequence-specific guide RNAs, we show high-resolution and selective isolation of chromatin interactions at a single-copy genomic locus. Purification of human telomeres using CAPTURE identifies known and new telomeric factors. In situ capture of individual constituents of the enhancer cluster controlling human β-globin …

Evaluation Of Smartstax And Smartstax Pro Maize Against Western Corn Rootworm And Northern Corn Rootworm: Efficacy And Resistance Management, Graham P. Head, Matthew W. Carroll, Sean P. Evans, Dwain M. Rule, Alan R. Willse, Thomas L. Clark, Nicholas P. Storer, Ronald D. Flannagan, Luke W. Samuel, Lance Meinke

Department of Entomology: Faculty Publications

Background: Cases of western corn rootworm (WCR) field-evolved resistance to Cry3Bb1 and other corn rootworm (CRW) control traits have been reported. Pyramid products expressing multiple CRW traits can delay resistance compared to single trait products. We used field studies to assess the pyramid CRW corn products, SmartStax (expressing Cry3Bb1 and Cry34Ab1/Cry35Ab1) and SmartStax PRO (expressing Cry3Bb1, Cry34Ab1/Cry35Ab1 and DvSnf7), at locations with high WCR densities and possible Cry3Bb1 resistance, and to assess the reduction in adult emergence attributable to DvSnf7 and other traits. Insect resistance models were used to assess durability of SmartStax and SmartStax PRO to WCR resistance.

Results: …

Gene Expression Profiling In An Alzheimer's Disease Mouse Model, Matthew R. Dalton

Senior Honors Theses

Explaining precisely how Alzheimer’s disease (AD)—the world’s most common form of dementia—materializes in the human brain has proven to be one of the most elusive ends in modern medicine. Progressive memory loss, neurodegeneration, and the presence of abnormal protein aggregates of amyloid-beta (Aβ) and neurofibrillary tangles (NFT) characterize this disease. Genome sequencing provides researchers with the ability to better identify disease-related changes in gene expression, some of which may play a role in the initiation and progression toward the AD-like state. Intimate interactions between tissues have been observed in many diseases, particularly between the brain and blood. This analysis seeks …

Comparing Apples And Oranges?: Next Generation Sequencing And Its Impact On Microbiome Analysis, Adam G. Clooney, Fiona Fouhy, Roy D. Sleator, Aisling O'Driscoll, Stanton Catherine, Paul D. Cotter, Marcus J. Claesson

Department of Biological Sciences Publications

Rapid advancements in sequencing technologies along with falling costs present widespread opportunities for microbiome studies across a vast and diverse array of environments. These impressive technological developments have been accompanied by a considerable growth in the number of methodological variables, including sampling, storage, DNA extraction, primer pairs, sequencing technology, chemistry version, read length, insert size, and analysis pipelines, amongst others. This increase in variability threatens to compromise both the reproducibility and the comparability of studies conducted. Here we perform the first reported study comparing both amplicon and shotgun sequencing for the three leading next-generation sequencing technologies. These were applied to …

Coordination Of Rna Polymerase Ii Pausing And 3' End Processing Factor Recruitment With Alternative Polyadenylation, Becky Fusby, Soojin Kim, Benjamin Erickson, Hyunmin Kim, Martha L. Peterson, David L Bentley

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Most mammalian genes produce transcripts whose 3' ends are processed at multiple alternative positions by cleavage/polyadenylation (CPA). Poly(A) site cleavage frequently occurs cotranscriptionally and is facilitated by CPA factor binding to the RNA polymerase II (Pol II) C-terminal domain (CTD) phosphorylated on Ser2 residues of its heptad repeats (YS₂PTSPS). The function of cotranscriptional events in the selection of alternative poly(A) sites is poorly understood. We investigated Pol II pausing, CTD Ser2 phosphorylation, and processing factor CstF recruitment at wild-type and mutant IgM transgenes that use alternative poly(A) sites to produce mRNAs encoding the secreted and membrane-bound forms of …

Coexpression Network Analysis Of Mirna-142 Overexpression In Neuronal Cells, Ishwor Thapa, Howard S. Fox, Dhundy Raj Bastola

Interdisciplinary Informatics Faculty Publications

MicroRNAs are small noncoding RNA molecules, which are differentially expressed in diverse biological processes and are also involved in the regulation of multiple genes. A number of sites in the 3′ untranslated regions (UTRs) of different mRNAs allow complimentary binding for a microRNA, leading to their posttranscriptional regulation. The miRNA-142 is one of the microRNAs overexpressed in neurons that is found to regulate SIRT1 and MAOA genes. Differential analysis of gene expression data, which is focused on identifying up- or downregulated genes, ignores many relationships between genes affected by miRNA-142 overexpression in a cell. Thus, we applied a correlation network …

Analysis Of Differential Mrna And Mirna Expression In An Alzheimer’S Disease Mouse Model, Amanda Hazy, Matthew Dalton

Other Undergraduate Scholarship

Research has shown that changes in gene expression play a critical role in the development of Alzheimer’s Disease (AD). Our project will evaluate genome-wide RNA expression patterns from brain and blood in an AD mouse model. This analysis will provide insight regarding the mechanisms of AD pathology as well as determine a possible diagnostic tool utilizing RNA expression patterns found in the blood as biomarkers for AD.

Integrated Transcriptome Analysis Reveals Mirna-Mrna Crosstalk In Laryngeal Squamous Cell Carcinoma., Yang Zhang, Yong Chen, Jinhai Yu, Guiming Liu, Zhigang Huang

Faculty Scholarship for the College of Science & Mathematics

Next generation sequencing (NGS) has proven to be a powerful tool in delineating myriads of molecular subtypes of cancer, as well as in revealing accumulation of genomic mutations throughout cancer progression. Whole genome microRNA (miRNA) and mRNA expression profiles were obtained from patients with laryngeal squamous cell carcinoma (LSCC) using deep sequencing technology, and were analyzed by utilizing integrative computational approaches. A large number of protein-coding and non-coding genes were detected to be differentially expressed, indicating a functional switch in LSCC cells. A total of 127 mutated genes were detected to be significantly associated with ectoderm and epidermis development. Eleven …

Population And Demographic Structure Of Ixodes Scapularis Say In The Eastern United States., Joyce M. Sakamoto, Jerome Goddard, Jason L. Rasgon

College of Agriculture & Life Sciences Publications and Scholarship

INTRODUCTION: The most significant vector of tick-borne pathogens in the United States is Ixodes scapularis Say (the blacklegged tick). Previous studies have identified significant genetic, behavioral and morphological differences between northern vs. southern populations of this tick. Because tick-borne pathogens are dependent on their vectors for transmission, a baseline understanding of the vector population structure is crucial to determining the risks and epidemiology of pathogen transmission. METHODS: We investigated population genetic variation of I. scapularis populations in the eastern United States using a multilocus approach. We sequenced and analyzed the mitochondrial COI and 16S genes and three nuclear genes (serpin2, …

Genome-Wide Sequencing Of Small Rnas Reveals A Tissue-Specific Loss Of Conserved Microrna Families In Echinococcus Granulosus, Yun Bai, Zhuangzhi Zhang, Lei Jin, Hui Kang, Yongquiang Zhu, Lu Zhang, Xia Li, Fengshou Ma, Li Zhao, Et Al.

PCOM Scholarly Papers

Background: MicroRNAs (miRNAs) are important post-transcriptional regulators which control growth and development in eukaryotes. The cestode Echinococcus granulosus has a complex life-cycle involving different development stages but the mechanisms underpinning this development, including the involvement of miRNAs, remain unknown. Results: Using Illumina next generation sequencing technology, we sequenced at the genome-wide level three small RNA populations from the adult, protoscolex and cyst membrane of E. granulosus. A total of 94 pre-miRNA candidates (coding 91 mature miRNAs and 39 miRNA stars) were in silico predicted. Through comparison of expression profiles, we found 42 mature miRNAs and 23 miRNA stars expressed with …

Characteristics And Prediction Of Rna Structure., Hengwu Li, Daming Zhu, Caiming Zhang, Huijian Han, Keith A Crandall

Computational Biology Institute

RNA secondary structures with pseudoknots are often predicted by minimizing free energy, which is NP-hard. Most RNAs fold during transcription from DNA into RNA through a hierarchical pathway wherein secondary structures form prior to tertiary structures. Real RNA secondary structures often have local instead of global optimization because of kinetic reasons. The performance of RNA structure prediction may be improved by considering dynamic and hierarchical folding mechanisms. This study is a novel report on RNA folding that accords with the golden mean characteristic based on the statistical analysis of the real RNA secondary structures of all 480 sequences from RNA …

Antisense Transcription Is Pervasive But Rarely Conserved In Enteric Bacteria, Rahul Raghavan, D. B. Sloan, H. Ochman

Biology Faculty Publications and Presentations

Noncoding RNAs, including antisense RNAs (asRNAs) that originate from the complementary strand of protein-coding genes, are involved in the regulation of gene expression in all domains of life. Recent application of deep-sequencing technologies has revealed that the transcription of asRNAs occurs genome-wide in bacteria. Although the role of the vast majority of asRNAs remains unknown, it is often assumed that their presence implies important regulatory functions, similar to those of other noncoding RNAs. Alternatively, many antisense transcripts may be produced by chance transcription events from promoter-like sequences that result from the degenerate nature of bacterial transcription factor binding sites. To …

Increased Variability Of Microbial Communities In Restored Salt Marshes Nearly 30 Years After Tidal Flow Restoration, Anne E. Bernhard, David Marshall, Lazaros Yiannos

Biology Faculty Publications

We analyzed microbial diversity and community composition from four salt marsh sites that were impounded for 40–50 years and subsequently restored and four unimpounded sites in southeastern Connecticut over one growing season. Community composition and diversity were assessed by terminal restriction fragment length polymorphism (TRFLP) and sequence analysis of 16S ribosomal RNA (rRNA) genes. Our results indicated diverse communities, with sequences representing 14 different bacterial divisions. Proteobacteria, Bacteroidetes, and Planctomycetes dominated clone libraries from both restored and unimpounded sites. Multivariate analysis of the TRFLP data suggest significant site, sample date, and restoration status effects, but the exact causes of these …

Tissue Sampling Methods And Standards For Vertebrate Genomics, Pamela B. Y. Wong, Edward O. Wiley, Warren E. Johnson, Oliver A. Ryder, Stephen J. O'Brien, David Haussler, Klaus-Peter Koepfli, Marlys L. Houck, Polina L. Perelman, Gabriela Mastromonaco, Andrew C. Bentley, Byrappa Venkatesh, Ya-Ping Zhang, Robert W. Murphy, Genome 10k Project Community Of Scientists

Biology Faculty Articles

The recent rise in speed and efficiency of new sequencing technologies have facilitated high-throughput sequencing, assembly and analyses of genomes, advancing ongoing efforts to analyze genetic sequences across major vertebrate groups. Standardized procedures in acquiring high quality DNA and RNA and establishing cell lines from target species will facilitate these initiatives. We provide a legal and methodological guide according to four standards of acquiring and storing tissue for the Genome 10K Project and similar initiatives as follows: four-star (banked tissue/cell cultures, RNA from multiple types of tissue for transcriptomes, and sufficient flash-frozen tissue for 1 mg of DNA, all from …

Help3 Directly Modulates The Expression Of Hsp70 Gene In Hela Cells Via Hat Activity, Fen Li, Jixian Ma, Yu Ma, Yanyan Hu, Shuhuan Tian, Richard E. White, Guichun Han

PCOM Scholarly Papers

Human Elongator complex, which plays a key role in transcript elongation in vitro assay, is incredibly similar in either components or function to its yeast counterpart. However, there are only a few studies focusing on its target gene characterization in vivo. We studied the effect of down-regulation of the human elongation protein 3 (hELP3) on the expression of HSP70 through antisense strategy. Transfecting antisense plasmid p1107 into HeLa cells highly suppressed hELP3 expression, and substantially reduced expression of HSP70 mRNA and protein. Furthermore, chromatin immunoprecipitation assay (ChIP Assay) revealed that hElp3 participates in the transcription elongation of HSPA1A in HeLa …

Anomalous Constitutive Src Kinase Activity Promotes B Lymphoma Survival And Growth, Jiyuan Ke, R. Lakshman Chelvarajan, Vishal Sindhava, Darrell A. Robertson, Lazaros Lekakis, C. Darrell Jennings, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Background: Previously we have shown that B cell receptor (BCR) expression and B cell receptor signaling pathways are important for the basal growth of B lymphoma cells. In particular we have shown that the activation of Syk, a non-src family protein tyrosine kinase and the mitogen activated protein kinases (MAPK), ERK and JNK that mediate BCR signals are required for the constitutive growth of B lymphoma cells. Since src family protein tyrosine kinases (SFKs) like Lyn are known to be needed for the phosphorylation of BCR co-receptors, Ig-alpha and Ig-beta, we hypothesized that one or more SFKs will be constitutively …

Apolipoprotein E But Not B Is Required For The Formation Of Infectious Hepatitis C Virus Particles, Jieyun Jiang, Guangxiang Luo

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Our previous studies have found that hepatitis C virus (HCV) particles are enriched in apolipoprotein E (apoE) and that apoE is required for HCV infectivity and production. Studies by others, however, suggested that both microsomal transfer protein (MTP) and apoB are important for HCV production. To define the roles of apoB and apoE in the HCV life cycle, we developed a single-cycle HCV growth assay to determine the correlation of HCV assembly with apoB and apoE expression, as well as the influence of MTP inhibitors on the formation of HCV particles. The small interfering RNA (siRNA)-mediated knockdown of apoE expression …

Comparison Of Dna Pyrosequencing With Alternative Methods For Identification Of Mycobacteria, Loree C. Heller, Michael Jones, Ray H. Widen

Bioelectrics Publications

Identification of mycobacterial clinical isolates by pyrosequencing within the hypervariable A region of the 16S rRNA gene was compared to other identification methods. For >90% of isolates, these identifications correlated to the level of complex or species. For identification of many mycobacteria, pyrosequencing offers an inexpensive alternative to traditional sequencing.

Effect Of Thyroid Hormone Concentration On The Transcriptional Response Underlying Induced Metamorphosis In The Mexican Axolotl (Ambystoma), Robert B. Page, Stephen R. Voss, Amy K. Samuels, Jeramiah J. Smith, Srikrishna Putta, Christopher K. Beachy

Biology Faculty Publications

BACKGROUND: Thyroid hormones (TH) induce gene expression programs that orchestrate amphibian metamorphosis. In contrast to anurans, many salamanders do not undergo metamorphosis in nature. However, they can be induced to undergo metamorphosis via exposure to thyroxine (T4). We induced metamorphosis in juvenile Mexican axolotls (Ambystoma mexicanum) using 5 and 50 nM T4, collected epidermal tissue from the head at four time points (Days 0, 2, 12, 28), and used microarray analysis to quantify mRNA abundances.

RESULTS: Individuals reared in the higher T4 concentration initiated morphological and transcriptional changes earlier and completed metamorphosis by Day 28. In contrast, initiation of metamorphosis …

C-Jun N-Terminal Kinase (Jnk) Is Required For Survival And Proliferation Of B-Lymphoma Cells, Murali Gururajan, Roger Chui, Anbu K. Karuppannan, Jiyuan Ke, C. Darrell Jennings, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Several primary murine and human B lymphomas and cell lines were found to constitutively express high levels of the activated form of c-jun N-terminal kinase (JNK), a member of the mitogen-activated protein (MAP) kinase family. Proliferation of murine B lymphomas CH31, CH12.Lx, BKS-2, and WEHI-231 and the human B lymphomas BJAB, RAMOS, RAJI, OCI-Ly7, and OCI-Ly10 was strongly inhibited by SP600125, an anthrapyrazolone inhibitor of JNK, in a dose-dependent manner. The lymphoma cells underwent apoptosis and arrested at the G2/M phase of cell cycle. Furthermore, JNK-specific small interfering RNA (siRNA) inhibited the growth of both murine and human B lymphomas. …

Prolonged Cyclooxygenase-2 Induction In Neurons And Glia Following Traumatic Brain Injury In The Rat, K I Strauss, M F Barbe, R M Marshall Demarest, R Raghupathi, S Mehta, R K Narayan

Rowan-Virtua School of Osteopathic Medicine Faculty Scholarship

Cyclooxygenase-2 (COX2) is a primary inflammatory mediator that converts arachidonic acid into precursors of vasoactive prostaglandins, producing reactive oxygen species in the process. Under normal conditions COX2 is not detectable, except at low abundance in the brain. This study demonstrates a distinctive pattern of COX2 increases in the brain over time following traumatic brain injury (TBI). Quantitative lysate ribonuclease protection assays indicate acute and sustained increases in COX2 mRNA in two rat models of TBI. In the lateral fluid percussion model, COX2 mRNA is significantly elevated (>twofold, p < 0.05, Dunnett) at 1 day postinjury in the injured cortex and bilaterally in the hippocampus, compared to sham-injured controls. In the lateral cortical impact model (LCI), COX2 mRNA peaks around 6 h postinjury in the ipsilateral cerebral cortex (fivefold induction, p < 0.05, Dunnett) and in the ipsilateral and contralateral hippocampus (two- and six-fold induction, respectively, p < 0.05, Dunnett). Increases are sustained out to 3 days postinjury in the injured cortex in both models. Further analyses use the LCI model to evaluate COX2 induction. Immunoblot analyses confirm increased levels of COX2 protein in the cortex and hippocampus. Profound increases in COX2 protein are observed in the cortex at 1-3 days, that return to sham levels by 7 days postinjury (p < 0.05, Dunnett). The cellular pattern of COX2 induction following TBI has been characterized using immunohistochemistry. COX2-immunoreactivity (-ir) rises acutely (cell numbers and intensity) and remains elevated for several days following TBI. Increases in COX2-ir colocalize with neurons (MAP2-ir) and glia (GFAP-ir). Increases in COX2-ir are observed in cerebral cortex and hippocampus, ipsilateral and contralateral to injury as early as 2 h postinjury. Neurons in the ipsilateral parietal, perirhinal and piriform cortex become intensely COX2-ir from 2 h to at least 3 days postinjury. In agreement with the mRNA and immunoblot results, COX2-ir appears greatest in the contralateral hippocampus. Hippocampal COX2-ir progresses from the pyramidal cell layer of the CA1 and CA2 region at 2 h, to the CA3 pyramidal cells and dentate polymorphic and granule cell layers by 24 h postinjury. These increases are distinct from those observed following inflammatory challenge, and correspond to brain areas previously identified with the neurological and cognitive deficits associated with TBI. While COX2 induction following TBI may result in selective beneficial responses, chronic COX2 production may contribute to free radical mediated cellular damage, vascular dysfunction, and alterations in cellular metabolism. These may cause secondary injuries to the brain that promote neuropathology and worsen behavioral outcome.

Transcriptional Regulation Of The Bmp2 Gene: Retinoic Acid Induction In F9 Embryonal Carcinoma Cells And Saccharomyces Cerevisiae, Loree C. Heller, Yong Li, Kevin L. Abrams, Melissa B. Rogers

Bioelectrics Publications

Bmp2, a highly conserved member of the transforming growth factor-beta gene family, is crucial for normal development. Retinoic acid, combined with cAMP analogs, sharply induces the Bmp2 mRNA during the differentiation of F9 embryonal carcinoma cells into parietal endoderm. Retinoic acid (RA) also induces the Bmp2 gene in chick limb buds. Since normal Bmp2 expression may require an endogenous retinoid signal and aberrant Bmp2 expression may cause some aspects of RA-induced teratogenesis, we studied the mechanism underlying the induction of Bmp2. Measurements of the Bmp2 mRNA half-life and nuclear run-on assays …