Medical Specialties Commons^™

Cardiac G-Protein-Coupled Receptor Kinase 2 Ablation Induces A Novel Ca2+ Handling Phenotype Resistant To Adverse Alterations And Remodeling After Myocardial Infarction., Philip W Raake, Xiaoying Zhang, Leif E Vinge, Henriette Brinks, Erhe Gao, Naser Jaleel, Yingxin Li, Mingxin Tang, Patrick Most, Gerald W Dorn, Steven R Houser, Hugo A Katus, Xiongwen Chen, Walter J Koch

Center for Translational Medicine Faculty Papers

BACKGROUND: G-protein-coupled receptor kinase 2 (GRK2) is a primary regulator of β-adrenergic signaling in the heart. G-protein-coupled receptor kinase 2 ablation impedes heart failure development, but elucidation of the cellular mechanisms has not been achieved, and such elucidation is the aim of this study.

METHODS AND RESULTS: Myocyte contractility, Ca(2+) handling and excitation-contraction coupling were studied in isolated cardiomyocytes from wild-type and GRK2 knockout (GRK2KO) mice without (sham) or with myocardial infarction (MI). In cardiac myocytes isolated from unstressed wild-type and GRK2KO hearts, myocyte contractions and Ca(2+) transients were similar, but GRK2KO myocytes had lower sarcoplasmic reticulum (SR) Ca(2+) content …

Il-1ri (Interleukin-1 Receptor Type I) Signalling Is Essential For Host Defence And Hemichannel Activity During Acute Central Nervous System Bacterial Infection., Juan Xiong, Maria Burkovetskaya, Nikolay Karpuk, Tammy Kielian

Journal Articles: Pathology and Microbiology

Staphylococcus aureus is a common aetiological agent of bacterial brain abscesses. We have previously established that a considerable IL-1 (interleukin-1) response is elicited immediately following S. aureus infection, where the cytokine can exert pleiotropic effects on glial activation and blood-brain barrier permeability. To assess the combined actions of IL-1α and IL-1β during CNS (central nervous system) infection, host defence responses were evaluated in IL-1RI (IL-1 receptor type I) KO (knockout) animals. IL-1RI KO mice were exquisitely sensitive to intracerebral S. aureus infection, as demonstrated by enhanced mortality rates and bacterial burdens within the first 24 h following pathogen exposure compared …

Dyschronic, A Drosophila Homolog Of A Deaf-Blindness Gene, Regulates Circadian Output And Slowpoke Channels., James E C Jepson, Mohammad Shahidullah, Angelique Lamaze, Drew Peterson, Huihui Pan, Kyunghee Koh

Farber Institute for Neuroscience Faculty Papers

Many aspects of behavior and physiology are under circadian control. In Drosophila, the molecular clock that regulates rhythmic patterns of behavior has been extensively characterized. In contrast, genetic loci involved in linking the clock to alterations in motor activity have remained elusive. In a forward-genetic screen, we uncovered a new component of the circadian output pathway, which we have termed dyschronic (dysc). dysc mutants exhibit arrhythmic locomotor behavior, yet their eclosion rhythms are normal and clock protein cycling remains intact. Intriguingly, dysc is the closest Drosophila homolog of whirlin, a gene linked to type II Usher syndrome, the leading cause …

Essential Role Of Caveolin-3 In Adiponectin Signalsome Formation And Adiponectin Cardioprotection., Yajing Wang, Xiaoliang Wang, Jean-François Jasmin, Wayne Bond Lau, Rong Li, Yuexin Yuan, Wei Yi, Kurt Chuprun, Michael P. Lisanti, Walter J Koch, Erhe Gao, Xin-Liang Ma

Department of Emergency Medicine Faculty Papers

OBJECTIVE: Adiponectin (APN) system malfunction is causatively related to increased cardiovascular morbidity/mortality in diabetic patients. The aim of the current study was to investigate molecular mechanisms responsible for APN transmembrane signaling and cardioprotection.

METHODS AND RESULTS: Compared with wild-type mice, caveolin-3 knockout (Cav-3KO) mice exhibited modestly increased myocardial ischemia/reperfusion injury (increased infarct size, apoptosis, and poorer cardiac function recovery; P

CONCLUSIONS: Taken together, these results demonstrated for the first time that Cav-3 plays an essential role in APN transmembrane signaling and APN anti-ischemic/cardioprotective actions.

A Role For Caveolin-1 In Desmoglein Binding And Desmosome Dynamics., D Brennan, S Peltonen, A Dowling, W Medhat, K J Green, J K Wahl, F Del Galdo, M G Mahoney

Department of Dermatology and Cutaneous Biology Faculty Papers

Desmoglein-2 (Dsg2) is a desmosomal cadherin that is aberrantly expressed in human skin carcinomas. In addition to its well-known role in mediating intercellular desmosomal adhesion, Dsg2 regulates mitogenic signaling that may promote cancer development and progression. However, the mechanisms by which Dsg2 activates these signaling pathways and the relative contribution of its signaling and adhesion functions in tumor progression are poorly understood. In this study we show that Dsg2 associates with caveolin-1 (Cav-1), the major protein of specialized membrane microdomains called caveolae, which functions in both membrane protein turnover and intracellular signaling. Sequence analysis revealed that Dsg2 contains a putative …

Motor Neuron Apoptosis And Neuromuscular Junction Perturbation Are Prominent Features In A Drosophila Model Of Fus-Mediated Als, Ruohan Xia, Yajuan Liu, Liuqing Yang, Jozsef Gal, Haining Zhu, Jianhang Jia

Markey Cancer Center Faculty Publications

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is progressive neurodegenerative disease characterized by the loss of motor function. Several ALS genes have been identified as their mutations can lead to familial ALS, including the recently reported RNA-binding protein fused in sarcoma (Fus). However, it is not clear how mutations of Fus lead to motor neuron degeneration in ALS. In this study, we present a Drosophila model to examine the toxicity of Fus, its Drosophila orthologue Cabeza (Caz), and the ALS-related Fus mutants.

RESULTS: Our results show that the expression of wild-type Fus/Caz or FusR521G induced progressive toxicity in multiple tissues of the …

Hyperphosphorylation Of The Cardiac Ryanodine Receptor At Serine 2808 Is Not Involved In Cardiac Dysfunction After Myocardial Infarction., Hongyu Zhang, Catherine A Makarewich, Hajime Kubo, Wei Wang, Jason M Duran, Ying Li, Remus M Berretta, Walter J Koch, Xiongwen Chen, Erhe Gao, Héctor H Valdivia, Steven R Houser

Division of Cardiology Faculty Papers

RATIONALE: Abnormal behavior of the cardiac ryanodine receptor (RyR2) has been linked to cardiac arrhythmias and heart failure (HF) after myocardial infarction (MI). It has been proposed that protein kinase A (PKA) hyperphosphorylation of the RyR2 at a single residue, Ser-2808, is a critical mediator of RyR dysfunction, depressed cardiac performance, and HF after MI.

OBJECTIVE: We used a mouse model (RyRS2808A) in which PKA hyperphosphorylation of the RyR2 at Ser-2808 is prevented to determine whether loss of PKA phosphorylation at this site averts post MI cardiac pump dysfunction.

METHODS AND RESULTS: MI was induced in wild-type (WT) and S2808A …

Inhibition Of Fatty Acid Synthase Attenuates Cd44-Associated Signaling And Reduces Metastasis In Colorectal Cancer, Yekaterina Y. Zaytseva, Piotr G. Rychahou, Pat Gulhati, Victoria Allison Elliott, William Conan Mustain, Kathleen O'Connor, Andrew J. Morris, Manjula Sunkara, Heidi L. Weiss, Eun Young Lee, B. Mark Evers

Markey Cancer Center Faculty Publications

Fatty acid synthase (FASN) and ATP-citrate lyase, key enzymes of de novo lipogenesis, are significantly upregulated and activated in many cancers and portend poor prognosis. Even though the role of lipogenesis in providing proliferative and survival advantages to cancer cells has been described, the impact of aberrant activation of lipogenic enzymes on cancer progression remains unknown. In this study, we found that elevated expression of FASN is associated with advanced stages of colorectal cancer (CRC) and liver metastasis, suggesting that it may play a role in progression of CRC to metastatic disease. Targeted inhibition of lipogenic enzymes abolished expression of …

Outer Space And Oocyte Developmental Competence., Andrew J Watson

Obstetrics & Gynaecology Publications

No abstract provided.

Cyclin D1 Induces Chromosomal Instability., Mathew C Casimiro, Richard Pestell

Department of Cancer Biology Faculty Papers

We developed mouse model systems to investigate the potential for cyclin D1 to induce CIN in vivo. In a mammary gland specific Tet-inducible model the acute expression profile regulated by cyclin D1 after 7 days was enriched in genes that rank highly with CIN. We also used a mammary gland targeted model (MMTV) to continuously express cyclin D1. The mice started to develop mammary gland tumors at 400 days and the tumor-free incidence was 40% in MMTV-cyclin D1. The gene expression profile of the tumors showed enrichment for the CIN signature. We next compared cyclin D1 expression and the highest …

Small Non-Coding Rnas Govern Mammary Gland Tumorigenesis., Zuoren Yu, Richard Pestell

Department of Cancer Biology Faculty Papers

Small non-coding RNAs include siRNA, miRNA, piRNA and snoRNA. The involvement of miRNAs in the regulation of mammary gland tumorigenesis has been widely studied while the role for other small non-coding RNAs remains unclear. Here we summarize the involvement of miRNA in breast cancer onset and progression through regulating the cell cycle and cellular proliferation. The regulation of breast cancer stem cells and tumor regeneration by miRNA is reviewed. In addition, the emerging evidence demonstrating the involvement of piRNA and snoRNA in breast cancer is briefly described.

Krüppel-Like Factor 4 Regulates Intestinal Epithelial Cell Morphology And Polarity, Tianxin Yu, Xi Chen, Wen Zhang, Juan Li, Ren Xu, Timothy C Wang, Walden Ai, Chunming Liu

Markey Cancer Center Faculty Publications

Krüppel-like factor 4 (KLF4) is a zinc finger transcription factor that plays a vital role in regulating cell lineage differentiation during development and maintaining epithelial homeostasis in the intestine. In normal intestine, KLF4 is predominantly expressed in the differentiated epithelial cells. It has been identified as a tumor suppressor in colorectal cancer. KLF4 knockout mice demonstrated a decrease in number of goblet cells in the colon, and conditional ablation of KLF4 from the intestinal epithelium led to altered epithelial homeostasis. However, the role of KLF4 in differentiated intestinal cells and colon cancer cells, as well as the mechanism by which …

A Placebo-Controlled, Double-Blind, Dose-Escalation Study To Assess The Safety, Tolerability And Pharmacokinetics/Pharmacodynamics Of Single And Multiple Intravenous Infusions Of Azd9773 In Patients With Severe Sepsis And Septic Shock, Peter E. Morris, Brian Zeno, Andrew C. Bernard, Xiangning Huang, Shampa Das, Timi Edeki, Steven G. Simonson, Gordon R. Bernard

Surgery Faculty Publications

INTRODUCTION: Tumor necrosis factor-alpha (TNF-α), an early mediator in the systemic inflammatory response to infection, is a potential therapeutic target in sepsis. The primary objective of this study was to determine the safety and tolerability of AZD9773, an ovine, polyclonal, anti-human TNF-α Fab preparation, in patients with severe sepsis. Secondary outcomes related to pharmacokinetic (PK) and pharmacodynamic (PD) parameters.

METHODS: In this double-blind, placebo-controlled, multicenter Phase IIa study, patients were sequentially enrolled into five escalating-dose cohorts (single doses of 50 or 250 units/kg; multiple doses of 250 units/kg loading and 50 units/kg maintenance, 500 units/kg loading and 100 units/kg maintenance, …

Loss Of Αt-Catenin Alters The Hybrid Adhering Junctions In The Heart And Leads To Dilated Cardiomyopathy And Ventricular Arrhythmia Following Acute Ischemia., Jifen Li, Steven Goossens, Jolanda Van Hengel, Erhe Gao, Lan Cheng, Koen Tyberghein, Xiying Shang, Riet De Rycke, Frans Van Roy, Glenn L Radice

Center for Translational Medicine Faculty Papers

It is generally accepted that the intercalated disc (ICD) required for mechano-electrical coupling in the heart consists of three distinct junctional complexes: adherens junctions, desmosomes and gap junctions. However, recent morphological and molecular data indicate a mixing of adherens junctional and desmosomal components, resulting in a 'hybrid adhering junction' or 'area composita'. The α-catenin family member αT-catenin, part of the N-cadherin-catenin adhesion complex in the heart, is the only α-catenin that interacts with the desmosomal protein plakophilin-2 (PKP2). Thus, it has been postulated that αT-catenin might serve as a molecular integrator of the two adhesion complexes in the area composita. …

Lithium Treatment Of Appswdi/Nos2−/− Mice Leads To Reduced Hyperphosphorylated Tau, Increased Amyloid Deposition And Altered Inflammatory Phenotype, Tiffany L. Sudduth, Joan G. Wilson, Angela Everhart, Carol A. Colton, Donna M. Wilcock

Sanders-Brown Center on Aging Faculty Publications

Lithium is an anti-psychotic that has been shown to prevent the hyperphosphorylation of tau protein through the inhibition of glycogen-synthase kinase 3-beta (GSK3β). We recently developed a mouse model that progresses from amyloid pathology to tau pathology and neurodegeneration due to the genetic deletion of NOS2 in an APP transgenic mouse; the APPSwDI/NOS2-/- mouse. Because this mouse develops tau pathology, amyloid pathology and neuronal loss we were interested in the effect anti-tau therapy would have on amyloid pathology, learning and memory. We administered lithium in the diets of APPSwDI/NOS2-/- mice for a period of eight months, followed by water maze …

Decorin-Mediated Inhibition Of Colorectal Cancer Growth And Migration Is Associated With E-Cadherin In Vitro And In Mice., Xiuli Bi, Nicole M Pohl, Zhibin Qian, George R Yang, Yuan Gou, Grace Guzman, Andre Kajdacsy-Balla, Renato V Iozzo, Wancai Yang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Previous studies have shown that decorin expression is significantly reduced in colorectal cancer tissues and cancer cells, and genetic deletion of the decorin gene is sufficient to cause intestinal tumor formation in mice, resulting from a downregulation of p21, p27(kip1) and E-cadherin and an upregulation of β-catenin signaling [Bi,X. et al. (2008) Genetic deficiency of decorin causes intestinal tumor formation through disruption of intestinal cell maturation. Carcinogenesis, 29, 1435-1440]. However, the regulation of E-cadherin by decorin and its implication in cancer formation and metastasis is largely unknown. Using a decorin knockout mouse model (Dcn(-/-) mice) and manipulated expression of decorin …

Direct Evidence For Inhibition Of Mitochondrial Permeability Transition Pore Opening By Sevoflurane Preconditioning In Cardiomyocytes: Comparison With Cyclosporine A., Anna Onishi, Masami Miyamae, Kazuhiro Kaneda, Junichiro Kotani, Vincent M. Figueredo

Division of Cardiology Faculty Papers

To assess whether sevoflurane preconditioning is associated with inhibition of mitochondrial permeability transition pore (MPTP), the effects of sevoflurane were compared with those of cyclosporine A, a known inhibitor of MPTP opening. Isolated perfused guinea pig hearts underwent 30 min global ischemia and 120 min reperfusion (control). Sevoflurane preconditioning was elicited by administration of 2% sevoflurane for 10 min with 10 min washout before ischemia (sevoflurane). A preconditioning-like cardioprotection was also induced by administering cyclosporine A (0.2 μM) for 15 min, starting 5 min before ischemia and for 10 min after the onset of reperfusion (cyclosporine A). Left ventricular developed …

Inflammatory Signaling Compromises Cell Responses To Interferon Alpha., W-C Huangfu, J Qian, C Liu, J Liu, A E Lokshin, D P Baker, H Rui, S Y Fuchs

Department of Cancer Biology Faculty Papers

Interferon alpha (IFNα) is widely used for treatment of melanoma and certain other malignancies. This cytokine as well as the related IFNβ exerts potent anti-tumorigenic effects; however, their efficacy in patients is often suboptimal. Here, we report that inflammatory signaling impedes the effects of IFNα/β. Melanoma cells can secrete pro-inflammatory cytokines that inhibit cellular responses to IFNα/β via activating the ligand-independent pathway for the phosphorylation and subsequent ubiquitination and accelerated degradation of the IFNAR1 chain of type I IFN receptor. Catalytic activity of the p38 protein kinase was required for IFNAR1 downregulation and inhibition of IFNα/β signaling induced by proinflammatory …

Myd88-Dependent Signaling Influences Fibrosis And Alternative Macrophage Activation During Staphylococcus Aureus Biofilm Infection., Mark L. Hanke, Amanda Angle, Tammy Kielian

Journal Articles: Pathology and Microbiology

Bacterial biofilms represent a significant therapeutic challenge based on their ability to evade host immune and antibiotic-mediated clearance. Recent studies have implicated IL-1β in biofilm containment, whereas Toll-like receptors (TLRs) had no effect. This is intriguing, since both the IL-1 receptor (IL-1R) and most TLRs impinge on MyD88-dependent signaling pathways, yet the role of this key adaptor in modulating the host response to biofilm growth is unknown. Therefore, we examined the course of S. aureus catheter-associated biofilm infection in MyD88 knockout (KO) mice. MyD88 KO animals displayed significantly increased bacterial burdens on catheters and surrounding tissues during early infection, which …

Gentamicin Rapidly Inhibits Mitochondrial Metabolism In High-Frequency Cochlear Outer Hair Cells, Heather Jensen Smith, Richard Hallworth, Michael G. Nichols

Journal Articles: Eppley Institute

Aminoglycosides (AG), including gentamicin (GM), are the most frequently used antibiotics in the world and are proposed to cause irreversible cochlear damage and hearing loss (HL) in 1/4 of the patients receiving these life-saving drugs. Akin to the results of AG ototoxicity studies, high-frequency, basal turn outer hair cells (OHCs) preferentially succumb to multiple HL pathologies while inner hair cells (IHCs) are much more resilient. To determine if endogenous differences in IHC and OHC mitochondrial metabolism dictate differential sensitivities to AG-induced HL, IHC- and OHC-specific changes in mitochondrial reduced nicotinamide adenine dinucleotide (NADH) fluorescence during acute (1 h) GM treatment …

Neuroangiogenesis: A Vascular Basis For Alzheimer's Disease And Cognitive Decline During Aging, Charles T. Ambrose

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Angiogenesis directs development of the brain's microcirculation during antenatal and postnatal development, but its role later in life is less well recognized. I contend that during senescence a reduced cerebral capillary density accounts in part for the vascular cognitive impairment observed in many older persons and possibly for some forms of Alzheimer's disease. I propose that neuroangiogenesis is essential throughout adult life for maintaining the microcirculation of the cerebral cortex and elsewhere in the brain and that it commonly declines with old age. To support this hypothesis I have examined the neurological literature for relevant studies on cerebral capillary density …

Microbubble Mediated Thrombus Dissolution With Diagnostic Ultrasound For The Treatment Of Chronic Venous Thrombi., Shelby Kutty, Juefei Wu, James M. Hammel, Feng Xie, Shunji Gao, Lucas K. Drvol, John Lof, Stanley J. Radio, Stacey L. Therrien, David A. Danford, Thomas R. Porter

Journal Articles: Pediatrics

BACKGROUND: Central venous catheter (CVC) thrombi result in significant morbidity in children, and currently available treatments are associated with significant risk. We sought to investigate the therapeutic efficacy of microbubble (MB) enhanced sonothrombolysis for aged CVC associated thrombi in vivo.

METHODS AND RESULTS: A model of chronic indwelling CVC in the low superior vena cava with thrombus in situ was established after feasibility and safety testing in 7 pigs; and subsequently applied for repeated, sonothrombolytic treatments in 9 pigs (total 24 treatments). Baseline intracardiac echocardiography (ICE, 10.5F, Siemens), fluoroscopy and saline flushing confirmed the absence of any pre-existing CVC thrombus. …

Cellular Retrograde Cardiomyoplasty And Relaxin Therapy For Postischemic Myocardial Repair In A Rat Model, Gabriella Di Lascio, Guy Harmelin, Mattia Targetti, Cristina Nanni, Giacomo Bianchi, Tommaso Gasbarri, Sandro Gelsomino, Daniele Bani, Sandra Zecchi Orlandini, Massimo Bonacchi

The Texas Heart Institute Journal

We sought to determine whether skeletal myoblasts, wild-type or engineered to express relaxin, might improve myocardial viability and performance in a rat model of chronic myocardial infarction. Our purpose was to investigate a potential new therapy for heart failure.

From October 2005 through September 2009, we surgically induced acute myocardial infarction in 80 male Wistar rats. Thirty days after surgery, the rats underwent reoperation for the retrograde coronary venous infusion of skeletal myoblasts, relaxin, or both. The animals were randomly assigned to 4 experimental groups: R1 (the control group, which underwent saline-solution infusion), R2 (systemic relaxin therapy), R3 (myoblast infusion), …

Microglial P38Α Mapk Is Critical For Lps-Induced Neuron Degeneration, Through A Mechanism Involving Tnfα, Bin Xing, Adam D. Bachstetter, Linda J. Van Eldik

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: The p38α MAPK isoform is a well-established therapeutic target in peripheral inflammatory diseases, but the importance of this kinase in pathological microglial activation and detrimental inflammation in CNS disorders is less well understood. To test the role of the p38α MAPK isoform in microglia-dependent neuron damage, we used primary microglia from wild-type (WT) or p38α MAPK conditional knockout (KO) mice in co-culture with WT cortical neurons, and measured neuron damage after LPS insult.

RESULTS: We found that neurons in co-culture with p38α-deficient microglia were protected against LPS-induced synaptic loss, neurite degeneration, and neuronal death. The involvement of the proinflammatory …

Wnt Signaling Exerts An Antiproliferative Effect On Adult Cardiac Progenitor Cells Through Igfbp3., Angelos Oikonomopoulos, Konstantina-Ioanna Sereti, Frank Conyers, Michael Bauer, Annette Liao, Jian Guan, Dylan Crapps, Jung-Kyu Han, Hanhua Dong, Ahmad F Bayomy, Gabriel C Fine, Karen Westerman, Travis L Biechele, Randall T Moon, Thomas Force, Ronglih Liao

Center for Translational Medicine Faculty Papers

RATIONALE: Recent work in animal models and humans has demonstrated the presence of organ-specific progenitor cells required for the regenerative capacity of the adult heart. In response to tissue injury, progenitor cells differentiate into specialized cells, while their numbers are maintained through mechanisms of self-renewal. The molecular cues that dictate the self-renewal of adult progenitor cells in the heart, however, remain unclear.

OBJECTIVE: We investigate the role of canonical Wnt signaling on adult cardiac side population (CSP) cells under physiological and disease conditions.

METHODS AND RESULTS: CSP cells isolated from C57BL/6J mice were used to study the effects of canonical …

Functional Genomics Reveals An Essential And Specific Role For Stat1 In Protection Of The Central Nervous System Following Herpes Simplex Virus Corneal Infection, Tracy J. Pasieka, Cristian Cilloniz, Victoria S. Carter, Pamela Rosato, Michael G. Katze, David A. Leib

Dartmouth Scholarship

Innate immune deficiencies result in a spectrum of severe clinical outcomes following infection. In particular, there is a strong association between loss of the signal transducer and activator of transcription (Stat) pathway, breach of the blood-brain barrier (BBB), and virus-induced neuropathology. The gene signatures that characterize resistance, disease, and mortality in the virus-infected nervous system have not been defined. Herpes simplex virus type 1 (HSV-1) is commonly associated with encephalitis in humans, and humans and mice lacking Stat1 display increased susceptibility to HSV central nervous system (CNS) infections. In this study, two HSV-1 strains were used, KOS (wild type [WT]), …

Culture Medium, Gas Atmosphere And Mapk Inhibition Affect Regulation Of Rna-Binding Protein Targets During Mouse Preimplantation Development., Michele D Calder, Patricia H Watson, Andrew J Watson

Obstetrics & Gynaecology Publications

During oogenesis, mammalian oocytes accumulate maternal mRNAs that support the embryo until embryonic genome activation. RNA-binding proteins (RBP) may regulate the stability and turnover of maternal and embryonic mRNAs. We hypothesised that varying embryo culture conditions, such as culture medium, oxygen tension and MAPK inhibition, affects regulation of RBPs and their targets during preimplantation development. STAU1, ELAVL1, KHSRP and ZFP36 proteins and mRNAs were detected throughout mouse preimplantation development, whereas Elavl2 mRNA decreased after the two-cell stage. Potential target mRNAs of RBP regulation, Gclc, Slc2a1 and Slc7a1 were detected during mouse preimplantation development. Gclc mRNA was significantly elevated in embryos …

Abca12-Mediated Lipid Transport And Snap29-Dependent Trafficking Of Lamellar Granules Are Crucial For Epidermal Morphogenesis In A Zebrafish Model Of Ichthyosis., Qiaoli Li, Michael Frank, Masashi Akiyama, Shiu-Ying Ho, Hiroshi Shimizu, Christine Thisse, Bernard Thisse, Eli Sprecher, Jouni Uitto

Department of Dermatology and Cutaneous Biology Faculty Papers

Zebrafish (Danio rerio) can serve as a model system to study heritable skin diseases. The skin is rapidly developed during the first 5-6 days of embryonic growth, accompanied by expression of skin-specific genes. Transmission electron microscopy (TEM) of wild-type zebrafish at day 5 reveals a two-cell-layer epidermis separated from the underlying collagenous stroma by a basement membrane with fully developed hemidesmosomes. Scanning electron microscopy (SEM) reveals an ordered surface contour of keratinocytes with discrete microridges. To gain insight into epidermal morphogenesis, we have employed morpholino-mediated knockdown of the abca12 and snap29 genes, which are crucial for secretion of lipids and …

Early Exposure To Paraquat Sensitizes Dopaminergic Neurons To Subsequent Silencing Of Pink1 Gene Expression In Mice., Hongxia Zhou, Cao Huang, Jianbin Tong, Xugang Xia

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Environmental exposure, genetic modification, and aging are considered risky for Parkinson's disease (PD). How these risk factors cooperate to induce progressive neurodegeneration in PD remains largely unknown. Paraquat is an herbicide commonly used for weed and grass control. Exposure to paraquat is associated with the increased incidence of PD. In contrast to familial PD, most sporadic PD cases do not have genetic mutation, but may suffer from partial dysfunction of neuron-protective genes as aging. Using conditional transgenic RNAi, we showed that temporal silencing of PINK1 expression in adult mice increased striatal dopamine, the phenotype that could not be induced by …

Proliferating Cell Nuclear Antigen Is Required For Loading Of The Smcx/Kmd5c Histone Demethylase Onto Chromatin., Zhihui Liang, Marc Diamond, Johanna A Smith, Matthias Schnell, René Daniel

Department of Medicine Faculty Papers

UNLABELLED: ABSTRACT:

BACKGROUND: Histone methylation is regulated by a large number of histone methyltransferases and demethylases. The recently discovered SMCX/KMD5C demethylase has been shown to remove methyl residues from lysine 4 of histone H3 (H3K4), and constitutes an important component of the regulatory element-1-silencing transcription factor (REST) protein complex. However, little is known about the cellular mechanisms that control SMCX activity and intracellular trafficking.

RESULTS: In this study, we found that small interfering RNA-mediated knockdown of proliferating cell nuclear antigen (PCNA) resulted in the reduction of the chromatin-bound SMCX fraction. We identified a PCNA-interaction protein motif (PIP box) in the …