Medicine and Health Sciences Commons^™

Low Dose Nicotine And Antagonism Of Β2 Subunit Containing Nicotinic Acetylcholine Receptors Have Similar Effects On Affective Behavior In Mice, Shawn M. Anderson, Darlene H. Brunzell

Pharmacology and Toxicology Publications

Nicotine leads to both activation and desensitization (inactivation) of nicotinic acetylcholine receptors (nAChRs). This study tested the hypothesis that nicotine and a selective antagonist of β2*nAChRs would have similar effects on affective behavior. Adult C57BL/6J male mice were tested in a conditioned emotional response (CER) assay which evaluates the ability of an aversive stimulus to inhibit goal-directed behavior. Mice lever-pressed for a saccharin reinforcer according to a variable schedule of reinforcement during sessions in which two presentations of a compound light/tone conditioned stimulus (CS) co-terminated with a 0.1 or 0.3 mA, 0.5 s footshock unconditioned stimulus (US). During testing in …

Mice Deficient In Gem Gtpase Show Abnormal Glucose Homeostasis Due To Defects In Beta-Cell Calcium Handling, Jenny E. Gunton, Mary Sisavanh, Rebecca A. Stokes, Jon Satin, Leslie S. Satin, Min Zhang, Sue M. Liu, Weikang Cai, Kim Cheng, Gregory J. Cooney, D. Ross Laybutt, Trina So, Juan-Carlos Molero, Shane T. Grey, Douglas A. Andres, Michael S. Rolph, Charles R. Mackay

Pharmacology and Toxicology Publications

Aims and Hypothesis

Glucose-stimulated insulin secretion from beta-cells is a tightly regulated process that requires calcium flux to trigger exocytosis of insulin-containing vesicles. Regulation of calcium handling in beta-cells remains incompletely understood. Gem, a member of the RGK (Rad/Gem/Kir) family regulates calcium channel handling in other cell types, and Gem over-expression inhibits insulin release in insulin-secreting Min6 cells. The aim of this study was to explore the role of Gem in insulin secretion. We hypothesised that Gem may regulate insulin secretion and thus affect glucose tolerance in vivo.

Methods

Gem-deficient mice were generated and their metabolic phenotype characterised by …

Acid Sphingomyelinase Gene Knockout Ameliorates Hyperhomocysteinemic Glomerular Injury In Mice Lacking Cystathionine-Β-Synthase, Krishna M. Boini, Min Xia, Justine M. Abais, Ming Xu, Cai-Xia Li, Pin-Lan Li

Pharmacology and Toxicology Publications

Acid sphingomyelinase (ASM) has been implicated in the development of hyperhomocysteinemia (hHcys)-induced glomerular oxidative stress and injury. However, it remains unknown whether genetically engineering of ASM gene produces beneficial or detrimental action on hHcys-induced glomerular injury. The present study generated and characterized the mice lacking cystathionine β-synthase (Cbs) and Asm mouse gene by cross breeding Cbs+/− and Asm+/− mice. Given that the homozygotes of Cbs−/−/Asm−/− mice could not survive for 3 weeks. Cbs+/−/Asm+/+, Cbs+/−/Asm+/− and Cbs+/−/Asm−/− as well as their Cbs wild type littermates were used to study the role of Asm−/− under a background of Cbs+/− with hHcys. HPLC …

Discovery Of Prostamide F2Α And Its Role In Inflammatory Pain And Dorsal Horn Nociceptive Neuron Hyperexcitability, Luisa Gatta, Fabiana Piscitelli, Catia Giordano, Serana Boccella, Aron H. Lichtman, Sebatino Maione, Vincenzo Di Marzo

Pharmacology and Toxicology Publications

It was suggested that endocannabinoids are metabolized by cyclooxygenase (COX)-2 in the spinal cord of rats with kaolin/λ-carrageenan-induced knee inflammation, and that this mechanism contributes to the analgesic effects of COX-2 inhibitors in this experimental model. We report the development of a specific method for the identification of endocannabinoid COX-2 metabolites, its application to measure the levels of these compounds in tissues, and the finding of prostamide F2α (PMF2α) in mice with knee inflammation. Whereas the levels of spinal endocannabinoids were not significantly altered by kaolin/λ-carrageenan-induced knee inflammation, those of the COX-2 metabolite of AEA, PMF2α, were strongly elevated. The …

Lipid Environment Modulates The Development Of Acute Tolerance To Ethanol In Caenorhabditis Elegans, Jill C. Bettinger, Kapo Leung, Mia H. Bolling, Andrew D. Goldsmith, Andrew G. Davies

Pharmacology and Toxicology Publications

The development of tolerance to a drug at the level of the neuron reflects a homeostatic mechanism by which neurons respond to perturbations of their function by external stimuli. Acute functional tolerance (AFT) to ethanol is a fast compensatory response that develops within a single drug session and normalizes neuronal function despite the continued presence of the drug. We performed a genetic screen to identify genes required for the development of acute functional tolerance to ethanol in the nematode C. elegans. We identified mutations affecting multiple genes in a genetic pathway known to regulate levels of triacylglycerols (TAGs) via …

Morphine Decreases Enteric Neuron Excitability Via Inhibition Of Sodium Channels, Tricia H. Smith, John R. Grider, William L. Dewey, Hamid I. Akbarali

Pharmacology and Toxicology Publications

Gastrointestinal peristalsis is significantly dependent on the enteric nervous system. Constipation due to reduced peristalsis is a major side-effect of morphine, which limits the chronic usefulness of this excellent pain reliever in man. The ionic basis for the inhibition of enteric neuron excitability by morphine is not well characterized as previous studies have mainly utilized microelectrode recordings from whole mount myenteric plexus preparations in guinea pigs. Here we have developed a Swiss-Webster mouse myenteric neuron culture and examined their electrophysiological properties by patch-clamp techniques and determined the mechanism for morphine-induced decrease in neuronal excitability. Isolated neurons in culture were confirmed …

Otx But Not Mitf Transcription Factors Are Required For Zebrafish Retinal Pigment Epithelium Development, Brandon M. Lane, James A. Lister

Human and Molecular Genetics Publications

Otx and Mitf transcription factors have been implicated in the development of the retinal pigmented epithelium (RPE), but the relationship between these factors and their specific roles in the development of the RPE have not been fully defined. The role of the three Otx transcription factors (Otx1a, Otx1b, and Otx2) and two Mitf transcription factors (Mitfa and Mitfb) in the development of the zebrafish RPE was explored in these experiments. The loss of Otx activity through morpholino knockdown produced variable eye defects, ranging from delayed RPE pigmentation to severe coloboma, depending on the combination of Otx factors that were targeted. …

A First-Generation Multi-Functional Cytokine For Simultaneous Optical Tracking And Tumor Therapy, Shawn Hingtgen, Randa Kasmieh, Elizabeth Elbayly, Irina Nesterenko, Jose-Luiz Figueiredo, Rupesh Dash, Devanand Sarkar, David Hall, Dima Kozakov, Sandor Vajda, Paul B. Fisher, Khalid Shah

Human and Molecular Genetics Publications

Creating new molecules that simultaneously enhance tumor cell killing and permit diagnostic tracking is vital to overcoming the limitations rendering current therapeutic regimens for terminal cancers ineffective. Accordingly, we investigated the efficacy of an innovative new multi-functional targeted anti-cancer molecule, SM7L, using models of the lethal brain tumor Glioblastoma multiforme (GBM). Designed using predictive computer modeling, SM7L incorporates the therapeutic activity of the promising anti-tumor cytokine MDA-7/IL-24, an enhanced secretory domain, and diagnostic domain for non-invasive tracking. In vitro assays revealed the diagnostic domain of SM7L produced robust photon emission, while the therapeutic domain showed marked anti-tumor efficacy and significant …

Genetic Dissection Of Acute Ethanol Responsive Gene Networks In Prefrontal Cortex: Functional And Mechanistic Implications, Aaron R. Wolen, Charles A. Phillips, Michael A. Langston, Alex H. Putman, Paul J. Vorster, Nathan A. Bruce, Timothy P. York, Robert W. Williams, Michael F. Miles

Human and Molecular Genetics Publications

Background

Individual differences in initial sensitivity to ethanol are strongly related to the heritable risk of alcoholism in humans. To elucidate key molecular networks that modulate ethanol sensitivity we performed the first systems genetics analysis of ethanol-responsive gene expression in brain regions of the mesocorticolimbic reward circuit (prefrontal cortex, nucleus accumbens, and ventral midbrain) across a highly diverse family of 27 isogenic mouse strains (BXD panel) before and after treatment with ethanol.

Results

Acute ethanol altered the expression of ~2,750 genes in one or more regions and 400 transcripts were jointly modulated in all three. Ethanol-responsive gene networks were extracted …

A Duplication Cnv That Conveys Traits Reciprocal To Metabolic Syndrome And Protects Against Diet-Induced Obesity In Mice And Men, Melanie Lacaria, Pradip Saha, Lorraine Potocki, Weimin Bi, Jiong Yan, Santhosh Girirajan, Brooke Burns, Sarah H. Elsea, Katherina Walz, Lawrence Chan, James R. Lupski, Wenli Gu

Human and Molecular Genetics Publications

The functional contribution of CNV to human biology and disease pathophysiology has undergone limited exploration. Recent observations in humans indicate a tentative link between CNV and weight regulation. Smith-Magenis syndrome (SMS), manifesting obesity and hypercholesterolemia, results from a deletion CNV at 17p11.2, but is sometimes due to haploinsufficiency of a single gene, RAI1. The reciprocal duplication in 17p11.2 causes Potocki-Lupski syndrome (PTLS). We previously constructed mouse strains with a deletion,Df(11)17, or duplication, Dp(11)17, of the mouse genomic interval syntenic to the SMS/PTLS region. We demonstrate that Dp(11)17 is obesity-opposing; it conveys a highly penetrant, strain-independent phenotype …