Digital Commons Network^™

Phenotypes Associated With Knockouts Of Eight Dense Granule Gene Loci (Gra2-9) In Virulent Toxoplasma Gondii, Leah M. Rommereim, Valeria Bellini, Barbara A. Fox, Graciane Pètre, Camille Rak, Bastien Touquet, Delphine Aldebert, Jean-François Dubremetz, Marie-France Cesbron-Delauw, Corinne Mercier, David J. Bzik

Dartmouth Scholarship

Toxoplasma gondii actively invades host cells and establishes a parasitophorous vacuole (PV) that accumulates many proteins secreted by the dense granules (GRA proteins). To date, at least 23 GRA proteins have been reported, though the function(s) of most of these proteins still remains unknown. We targeted gene knockouts at ten GRA gene loci (GRA1-10) to investigate the cellular roles and essentiality of these classical GRA proteins during acute infection in the virulent type I RH strain. While eight of these genes (GRA2-9) were successfully knocked out, targeted knockouts at the GRA1 and GRA10 loci were not …

Secretion Of Rhoptry And Dense Granule Effector Proteins By Nonreplicating Toxoplasma Gondii Uracil Auxotrophs Controls The Development Of Antitumor Immunity, Barbara A. Fox, Kiah L. Sanders, Leah M. Rommereim, Rebekah B. Guevara, David J. Bzik

Dartmouth Scholarship

Nonreplicating type I uracil auxotrophic mutants of Toxoplasma gondii possess a potent ability to activate therapeutic immunity to established solid tumors by reversing immune suppression in the tumor microenvironment. Here we engineered targeted deletions of parasite secreted effector proteins using a genetically tractable Δku80 vaccine strain to show that the secretion of specific rhoptry (ROP) and dense granule (GRA) proteins by uracil auxotrophic mutants of T. gondii in conjunction with host cell invasion activates antitumor immunity through host responses involving CD8α⁺ dendritic cells, the IL-12/interferon-gamma (IFN-γ) T_H1 axis, as well as CD4⁺ and CD8 …

Repeated Closed Head Injury In Mice Results In Sustained Motor And Memory Deficits And Chronic Cellular Changes, Amanda Nicholle Bolton Hall, Binoy Joseph, Jennifer M. Brelsfoard, Kathryn E. Saatman

Spinal Cord and Brain Injury Research Center Faculty Publications

Millions of mild traumatic brain injuries (TBIs) occur every year in the United States, with many people subject to multiple head injuries that can lead to chronic behavioral dysfunction. We previously reported that mild TBI induced using closed head injuries (CHI) repeated at 24h intervals produced more acute neuron death and glial reactivity than a single CHI, and increasing the length of time between injuries to 48h reduced the cumulative acute effects of repeated CHI. To determine whether repeated CHI is associated with behavioral dysfunction or persistent cellular damage, mice receiving either five CHI at 24h intervals, five CHI at …

Red-Shifted Aequorin Variants Incorporating Non-Canonical Amino Acids: Applications In In Vivo Imaging, Kristen M. Grinstead, Laura Rowe, Mark Ensor, Smita Joel, Pirouz Daftarian, Emre Dikici, Jean-Marc Zingg, Sylvia Daunert

Pharmaceutical Sciences Faculty Publications

The increased importance of in vivo diagnostics has posed new demands for imaging technologies. In that regard, there is a need for imaging molecules capable of expanding the applications of current state-of-the-art imaging in vivo diagnostics. To that end, there is a desire for new reporter molecules capable of providing strong signals, are non-toxic, and can be tailored to diagnose or monitor the progression of a number of diseases. Aequorin is a non-toxic photoprotein that can be used as a sensitive marker for bioluminescence in vivo imaging. The sensitivity of aequorin is due to the fact that bioluminescence is a …

Structure And Functions Of Angiotensinogen, Hong Lu, Lisa A. Cassis, Craig W. Vander Kooi, Alan Daugherty

Saha Cardiovascular Research Center Faculty Publications

Angiotensinogen (AGT) is the sole precursor of all angiotensin peptides. Although AGT is generally considered as a passive substrate of the renin–angiotensin system, there is accumulating evidence that the regulation and functions of AGT are intricate. Understanding the diversity of AGT properties has been enhanced by protein structural analysis and animal studies. In addition to whole-body genetic deletion, AGT can be regulated in vivo by cell-specific procedures, adeno-associated viral approaches and antisense oligonucleotides. Indeed, the availability of these multiple manipulations of AGT in vivo has provided new insights into the multifaceted roles of AGT. In this review, the combination of …

Mutation Linked To Autosomal Dominant Nocturnal Frontal Lobe Epilepsy Reduces Low-Sensitivity Α4Β2, And Increases Α5Α4Β2, Nicotinic Receptor Surface Expression, Weston A. Nichols, Brandon J. Henderson, Christopher B. Marotta, Caroline Y. Yu, Chris Richards, Dennis A. Dougherty, Henry A. Lester, Bruce N. Cohen

Chemistry Faculty Publications

A number of mutations in α4β2-containing (α4β2*) nicotinic acetylcholine (ACh) receptors (nAChRs) are linked to autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE), including one in the β2 subunit called β2V287L. Two α4β2* subtypes with different subunit stoichiometries and ACh sensitivities co-exist in the brain, a high-sensitivity subtype with (α4)₂(β2)₃ subunit stoichiometry and a low-sensitivity subtype with (α4)₃(β2)₂ stoichiometry. The α5 nicotinic subunit also co-assembles with α4β2 to form a high-sensitivity α5α4β2 nAChR. Previous studies suggest that the β2V287L mutation suppresses low-sensitivity α4β2* nAChR expression in a knock-in mouse model and also that α5 co-expression …

Staphylococcus Aureus Coordinates Leukocidin Expression And Pathogenesis By Sensing Metabolic Fluxes Via Rpirc, Divya Balasubramanian, Elizabeth A Ohneck, Jessica Chapman, Andy Weiss, Min Kyung Kim, Tamara Reyes-Robles, Judy Zhong, Lindsey N. Shaw, Desmond S. Lun, Beatrix Ueberheide, Bo Shopsin, Victor J Torres

Molecular Biosciences Faculty Publications

Staphylococcus aureus is a formidable human pathogen that uses secreted cytolytic factors to injure immune cells and promote infection of its host. Of these proteins, the bicomponent family of pore-forming leukocidins play critical roles in S. aureus pathogenesis. The regulatory mechanisms governing the expression of these toxins are incompletely defined. In this work, we performed a screen to identify transcriptional regulators involved in leukocidin expression in S. aureus strain USA300. We discovered that a metabolic sensor-regulator, RpiRc, is a potent and selective repressor of two leukocidins, LukED and LukSF-PV. Whole-genome transcriptomics, S. aureus exoprotein proteomics, and metabolomic analyses revealed that …

Thrombospondin 1 Deficiency Ameliorates The Development Of Adriamycin-Induced Proteinuric Kidney Disease, Hasiyeti Maimaitiyiming, Qi Zhou, Shuxia Wang

Pharmacology and Nutritional Sciences Faculty Publications

Accumulating evidence suggests that thrombospondin 1 (TSP1) is an important player in diabetic nephropathy. However, the role of TSP1 in podocyte injury and the development of non-diabetic proteinuric kidney disease is largely unknown. In the current study, by using a well-established podocyte injury model (adriamycin-induced nephropathy mouse model), we examined the contribution of TSP1 to the development of proteinuric kidney disease. We found that TSP1 was up-regulated in the glomeruli, notably in podocytes, in adriamycin injected mice before the onset of proteinuria. ADR treatment also stimulated TSP1 expression in cultured human podocytes in vitro. Moreover, increased TSP1 mediated ADR-induced …

Ubr3, A Novel Modulator Of Hh Signaling Affects The Degradation Of Costal-2 And Kif7 Through Poly-Ubiquitination, Tongchao Li, Junkai Fan, Bernardo Blanco-Sánchez, Nikolaos Giagtzoglou, Guang Lin, Shinya Yamamoto, Manish Jaiswal, Kuchuan Chen, Jie Zhang, Wei Wei, Michael T. Lewis, Andrew K. Groves, Monte Westerfield, Jianhang Jia, Hugo J. Bellen

Markey Cancer Center Faculty Publications

Hedgehog (Hh) signaling regulates multiple aspects of metazoan development and tissue homeostasis, and is constitutively active in numerous cancers. We identified Ubr3, an E3 ubiquitin ligase, as a novel, positive regulator of Hh signaling in Drosophila and vertebrates. Hh signaling regulates the Ubr3-mediated poly-ubiquitination and degradation of Cos2, a central component of Hh signaling. In developing Drosophila eye discs, loss of ubr3 leads to a delayed differentiation of photoreceptors and a reduction in Hh signaling. In zebrafish, loss of Ubr3 causes a decrease in Shh signaling in the developing eyes, somites, and sensory neurons. However, not all tissues that require …

Calpain-5 Expression In The Retina Localizes To Photoreceptor Synapses, Kellie A. Schaefer, Marcus A. Toral, Gabriel Velez, Allison J. Cox, Sheila A. Baker, Nicholas C. Borcherding, Diana F. Colgan, Vimala Bondada, Charles B. Mashburn, Chen Guang Yu, James W. Geddes, Stephen H. Tsang, Alexander G. Bassuk, Vinit B. Mahajan

Spinal Cord and Brain Injury Research Center Faculty Publications

Purpose: We characterize calpain-5 (CAPN5) expression in retinal and neuronal subcellular compartments.

Methods: CAPN5 gene variants were classified using the exome variant server, and RNA-sequencing was used to compare expression of CAPN5 mRNA in the mouse and human retina and in retinoblastoma cells. Expression of CAPN5 protein was ascertained in humans and mice in silico, in mouse retina by immunohistochemistry, and in neuronal cancer cell lines and fractionated central nervous system tissue extracts by Western analysis with eight antibodies targeting different CAPN5 regions.

Results: Most CAPN5 genetic variation occurs outside its protease core; and searches …

Phenotypic Characterization Of Adipose-Specific Vdr Knockout Mice, Joseph D'Angelo

Biological Sciences

Breast cancer is a prominent and lethal disease that currently affects close to three million people in the United States. Each year displays close to 250,000 new cases of breast cancer and around 40,000 deaths in the United States alone. A geographic pattern of breast cancer suggests a higher incidence in more temperate regions. Research has suggested that low Vitamin D levels associated with reduced sun exposure might contribute to increased breast cancer incidence. In recent studies, Vitamin D has been shown to slow the proliferation of breast cancer cells, but the mechanisms involved in vivo are poorly defined. It …

The Impact Of Polybrominated Diphenyl Ether (Bde-47) Administration In Mice And Its Implications In Non-Alcoholic Fatty Liver Disease, Kristen Ciampi

Senior Honors Projects

Non-alcoholic fatty liver disease (NAFLD) is a disease characterized by the accumulation of fat in liver cells that is not due to alcohol consumption. Steatosis results when more than 5-10% of the liver’s weight consists of fat. People who are overweight, or who have diabetes or high cholesterol are more likely to develop NAFLD. Over time, NAFLD can advance to cause cirrhosis, and eventually, liver cancer or failure.

Polybrominated diphenyl ethers (PBDEs, BDEs) are brominated flame- retardants, and are found in many plastics and household products such as cars, textiles, televisions, and computers. BDEs are released into the environment and …

Sex Differences In Calbindin-D28k Expressing Cells In The Brains Of Progesterone Receptor Knock Out Mice, Alexandria Sarenski

Anthropology

No abstract provided.

Tmem184b Promotes Axon Degeneration And Neuromuscular Junction Maintenance, Martha R.C. Bhattacharya, Stefanie Geisler, Sara K. Pittman, Ryan A. Doan, Conrad C. Weihl, Jeffrey Milbrandt, Aaron Diantonio

Open Access Publications

UNLABELLED: Complex nervous systems achieve proper connectivity during development and must maintain these connections throughout life. The processes of axon and synaptic maintenance and axon degeneration after injury are jointly controlled by a number of proteins within neurons, including ubiquitin ligases and mitogen activated protein kinases. However, our understanding of these molecular cascades is incomplete. Here we describe the phenotype resulting from mutation of TMEM184b, a protein identified in a screen for axon degeneration mediators. TMEM184b is highly expressed in the mouse nervous system and is found in recycling endosomes in neuronal cell bodies and axons. Disruption of TMEM184b expression …

Tgf-Β Neutralization Enhances Angii-Induced Aortic Rupture And Aneurysm In Both Thoracic And Abdominal Regions, Xiaofeng Chen, Debra L. Rateri, Deborah A. Howatt, Anju Balakrishnan, Jessica J. Moorleghen, Lisa A. Cassis, Alan Daugherty

Saha Cardiovascular Research Center Faculty Publications

AngII and TGF-β interact in development of thoracic and abdominal aortic diseases, although there are many facets of this interaction that have not been clearly defined. The aim of the present study was to determine the effects of TGF-β neutralization on AngII induced-aortic pathologies. Male C57BL/6J mice were administered with either a rabbit or mouse TGF-β neutralizing antibody and then infused with AngII. The rabbit TGF-β antibody modestly reduced serum TGF-β concentrations, with no significant enhancements to AngII-induced aneurysm or rupture. Administration of this rabbit TGF-β antibody in mice led to high serum titers against rabbit IgG that may have …

Agonist-Mediated Activation Of Sting Induces Apoptosis In Malignant B Cells, Chih-Hang Anthony Tang, Joseph A. Zundell, Sujeewa Ranatunga, Cindy Lin, Yulia Nefedova, Juan R. Del Valle, Chih-Chi Andrew Hu

Chemistry Faculty Publications

Endoplasmic reticulum (ER) stress responses through the IRE-1/XBP-1 pathway are required for the function of STING (TMEM173), an ER-resident transmembrane protein critical for cytoplasmic DNA sensing, IFN production, and cancer control. Here we show that the IRE-1/XBP-1 pathway functions downstream of STING and that STING agonists selectively trigger mitochondria-mediated apoptosis in normal and malignant B cells. Upon stimulation, STING was degraded less efficiently in B cells, implying that prolonged activation of STING can lead to apoptosis. Transient activation of the IRE-1/XBP-1 pathway partially protected agonist-stimulated malignant B cells from undergoing apoptosis. In Eμ-TCL1 mice with chronic lymphocytic leukemia, injection of …

Evidence That A Lipolytic Enzyme—Hematopoietic-Specific Phospholipase C-Β2—Promotes Mobilization Of Hematopoietic Stem Cells By Decreasing Their Lipid Raft-Mediated Bone Marrow Retention And Increasing The Promobilizing Effects Of Granulocytes, M. Adamiak, A. Poniewierska-Baran, S. Borkowska, G. Schneider, A. Abdelbaset-Ismail, M. Suszynska, Ahmed Abdel-Latif, M. Kucia, J. Ratajczak, M. Z. Ratajczak

Internal Medicine Faculty Publications

Hematopoietic stem/progenitor cells (HSPCs) reside in the bone marrow (BM) microenvironment and are retained there by the interaction of membrane lipid raft-associated receptors, such as the α-chemokine receptor CXCR4 and the α₄β₁-integrin (VLA-4, very late antigen 4 receptor) receptor, with their respective specific ligands, stromal-derived factor 1 and vascular cell adhesion molecule 1, expressed in BM stem cell niches. The integrity of the lipid rafts containing these receptors is maintained by the glycolipid glycosylphosphatidylinositol anchor (GPI-A). It has been reported that a cleavage fragment of the fifth component of the activated complement cascade, C5a, has an …

Impact Of Individual Acute Phase Serum Amyloid A Isoforms On Hdl Metabolism In Mice, Myung-Hee Kim, Maria C. De Beer, Joanne M. Wroblewski, Richard J. Charnigo, Ailing Ji, Nancy R. Webb, Frederick C. De Beer, Deneys R. Van Der Westhuyzen

Internal Medicine Faculty Publications

The acute phase (AP) reactant serum amyloid A (SAA), an HDL apolipoprotein, exhibits pro-inflammatory activities, but its physiological function(s) are poorly understood. Functional differences between SAA1.1 and SAA2.1, the two major SAA isoforms, are unclear. Mice deficient in either isoform were used to investigate plasma isoform effects on HDL structure, composition, and apolipoprotein catabolism. Lack of either isoform did not affect the size of HDL, normally enlarged in the AP, and did not significantly change HDL composition. Plasma clearance rates of HDL apolipoproteins were determined using native HDL particles. The fractional clearance rates (FCRs) of apoA-I, apoA-II, and SAA were …

Glycine N-Acyltransferase-Like 3 Is Responsible For Long-Chain N-Acylglycine Formation In N18Tg2 Cells, Kristen A Jeffries, Daniel R Dempsey, Emma K Farrell, Ryan L Anderson, Gabrielle J Garbade, Tatyana S Gurina, Imran Gruhonjic, Carly A Gunderson, David J Merkler

Chemistry Faculty Publications

Long-chain fatty acid amides are signaling lipids found in mammals and other organisms; however, details of the metabolic pathways for the N-acylglycines and primary fatty acid amides (PFAMs) have remained elusive. Heavy-labeled precursor and subtraction lipidomic experiments in mouse neuroblastoma N18TG2 cells, a model cell line for the study of fatty acid amide metabolism, establish the biosynthetic pathways for the N-acylglycines and the PFAMs. We provide evidence that the N-acylglycines are formed by a long-chain specific glycine-conjugating enzyme, glycine N-acyltransferase-like 3 (GLYATL3). siRNA knockdown of GLYATL3 in the N18TG2 cells resulted in a decrease in the levels of the N-acylglycines …

Correlation Of Maximal Inspiratory Pressure To Transdiaphragmatic Twitch Pressure In Intensive Care Unit Patients, Gerald S. Supinski, Philip M. Westgate, Leigh Ann Callahan

Internal Medicine Faculty Publications

Background: Respiratory muscle weakness contributes to respiratory failure in ICU patients. Unfortunately, assessment of weakness is difficult since the most objective test, transdiaphragmatic pressure in response to phrenic nerve stimulation (PdiTw), is difficult to perform. While most clinicians utilize maximum inspiratory pressure (Pimax) to assess strength, the relationship of this index to PdiTw has not been evaluated in a large ICU population. The purpose of the present study was to assess both PdiTw and Pimax in ICU patients to determine how these indices correlate with each other, what factors influence these indices, and how well these indices predict outcomes.

Methods: …

Vegfr2 Py949 Signalling Regulates Adherens Junction Integrity And Metastatic Spread, Xiujuan Li, Narendra Padhan, Elisabet O. Sjöström, Francis P. Roche, Chiara Testini, Naoki Honkura, Miguel Sáinz-Jaspeado, Emma Gordon, Katie Bentley, Andrew Philippides, Vladimir Tolmachev, Elisabetta Dejana, Radu V. Stan, Dietmar Vestweber, Kurt Ballmer-Hofer, Christer Betsholtz, Kristian Pietras, Leif Jansson, Lena Claesson-Welsh

Dartmouth Scholarship

The specific role of VEGFA-induced permeability and vascular leakage in physiology and pathology has remained unclear. Here we show that VEGFA-induced vascular leakage depends on signalling initiated via the VEGFR2 phosphosite Y949, regulating dynamic c-Src and VE-cadherin phosphorylation. Abolished Y949 signalling in the mouse mutant Vegfr2^Y949F/Y949F leads to VEGFA-resistant endothelial adherens junctions and a block in molecular extravasation. Vessels in Vegfr2^Y949F/Y949F mice remain sensitive to inflammatory cytokines, and vascular morphology, blood pressure and flow parameters are normal. Tumour-bearing Vegfr2^Y949F/Y949F mice display reduced vascular leakage and oedema, improved response to chemotherapy and, importantly, reduced metastatic spread. The inflammatory …

Arf6 Controls Platelet Spreading And Clot Retraction Via Integrin ΑIibΒ3 Trafficking, Yunjie Huang, Smita Joshi, Binggang Xiang, Yasunori Kanaho, Zhenyu Li, Beth A. Bouchard, Carole L. Moncman, Sidney W. Whiteheart

Molecular and Cellular Biochemistry Faculty Publications

Platelet and megakaryocyte endocytosis is important for loading certain granule cargo (ie, fibrinogen [Fg] and vascular endothelial growth factor); however, the mechanisms of platelet endocytosis and its functional acute effects are understudied. Adenosine 5'-diphosphate–ribosylation factor 6 (Arf6) is a small guanosine triphosphate–binding protein that regulates endocytic trafficking, especially of integrins. To study platelet endocytosis, we generated platelet-specific Arf6 knockout (KO) mice. Arf6 KO platelets had less associated Fg suggesting that Arf6 affects α_IIbβ₃-mediated Fg uptake and/or storage. Other cargo was unaffected. To measure Fg uptake, mice were injected with biotinylated- or fluorescein isothiocyanate (FITC)–labeled Fg. Platelets …

Smn Protein Can Be Reliably Measured In Whole Blood With An Electrochemiluminescence (Ecl) Immunoassay: Implications For Clinical Trials, Phillip Zaworski, Katharine M. Von Herrmann, Shannon Taylor, Sara S. Sunshine, Kathleen Mccarthy, Nicole Risher, Tara Newcomb, Marla Weetall, Thomas W. Prior, Kathryn J. Swoboda, Karen S. Chen, Sergey Paushkin

Dartmouth Scholarship

Spinal muscular atrophy (SMA) is caused by defects in the survival motor neuron 1 (SMN1) gene that encodes survival motor neuron (SMN) protein. The majority of therapeutic approaches currently in clinical development for SMA aim to increase SMN protein expression and there is a need for sensitive methods able to quantify increases in SMN protein levels in accessible tissues. We have developed a sensitive electrochemiluminescence (ECL)-based immunoassay for measuring SMN protein in whole blood with a minimum volume requirement of 5μL. The SMN-ECL immunoassay enables accurate measurement of SMN in whole blood and other tissues. Using the assay, …

Myonuclear Transcription Is Responsive To Mechanical Load And Dna Content But Uncoupled From Cell Size During Hypertrophy, Tyler J. Kirby, Rooshil M. Patel, Timothy S. Mcclintock, Esther E. Dupont-Versteegden, Charlotte A. Peterson, John J. Mccarthy

Physiology Faculty Publications

Myofibers increase size and DNA content in response to a hypertrophic stimulus, thus providing a physiological model with which to study how these factors affect global transcription. Using 5-ethynyl uridine (EU) to metabolically label nascent RNA, we measured a sevenfold increase in myofiber transcription during early hypertrophy before a change in cell size and DNA content. The typical increase in myofiber DNA content observed at the later stage of hypertrophy was associated with a significant decrease in the percentage of EU-positive myonuclei; however, when DNA content was held constant by preventing myonuclear accretion via satellite cell depletion, both the number …

Neurogenesis-Mediated Forgetting Minimizes Proactive Interference., Jonathan R Epp, Rudy Silva Mera, Stefan Köhler, Sheena A Josselyn, Paul W Frankland

Brain and Mind Institute Researchers' Publications

Established memories may interfere with the encoding of new memories, particularly when existing and new memories overlap in content. By manipulating levels of hippocampal neurogenesis, here we show that neurogenesis regulates this form of proactive interference. Increasing hippocampal neurogenesis weakens existing memories and, in doing so, facilitates the encoding of new, conflicting (but not non-conflicting) information in mice. Conversely, decreasing neurogenesis stabilizes existing memories, and impedes the encoding of new, conflicting information. These results suggest that reduced proactive interference is an adaptive benefit of neurogenesis-induced forgetting.

Cddo-Me Redirects Activation Of Breast Tumor Associated Macrophages, Michael S. Ball, Emilie P. Shipman, Hyunjung Kim, Karen T. Liby, Patricia A. Pioli

Dartmouth Scholarship

Tumor-associated macrophages can account for up to 50% of the tumor mass in breast cancer patients and high TAM density is associated with poor clinical prognosis. Because TAMs enhance tumor growth, development, and metastatic potential, redirection of TAM activation may have significant therapeutic benefit. Our studies in primary human macrophages and murine breast TAMs suggest that the synthetic oleanane triterpenoid CDDO-methyl ester (CDDO-Me) reprograms the activation profile of TAMs from tumor-promoting to tumor-inhibiting. We show that CDDO-Me treatment inhibits expression of IL-10 and VEGF in stimulated human M2 macrophages and TAMs but increases expression of TNF-α and IL-6. Surface expression …

Genomic Characterization Of Patient-Derived Xenograft Models Established From Fine Needle Aspirate Biopsies Of A Primary Pancreatic Ductal Adenocarcinoma And From Patient-Matched Metastatic Sites, Robert J. Allaway, Dawn A. Fischer, Francine B. De Abreu, Timothy B. Gardner, Stuart R. Gordon, Richard J. Barth, Thomas A. Colacchio, Matthew Wood, Balint Z. Kacsoh, Stephanie J. Bouley

Dartmouth Scholarship

N-of-1 trials target actionable mutations, yet such approaches do not test genomically-informed therapies in patient tumor models prior to patient treatment. To address this, we developed patient-derived xenograft (PDX) models from fine needle aspiration (FNA) biopsies (FNA-PDX) obtained from primary pancreatic ductal adenocarcinoma (PDAC) at the time of diagnosis. Here, we characterize PDX models established from one primary and two metastatic sites of one patient. We identified an activating KRAS G12R mutation among other mutations in these models. In explant cells derived from these PDX tumor models with a KRAS G12R mutation, treatment with inhibitors of CDKs (including CDK9) reduced …

Herpes Simplex Virus And Interferon Signaling Induce Novel Autophagic Clusters In Sensory Neurons, Sarah Katzenell, David A. Leib

Dartmouth Scholarship

Herpes simplex virus 1 (HSV-1) establishes lifelong infection in the neurons of trigeminal ganglia (TG), cycling between productive infection and latency. Neuronal antiviral responses are driven by type I interferon (IFN) and are crucial to controlling HSV-1 virulence. Autophagy also plays a role in this neuronal antiviral response, but the mechanism remains obscure. In this study, HSV-1 infection of murine TG neurons triggered unusual clusters of autophagosomes, predominantly in neurons lacking detectable HSV-1 antigen. Treatment of neurons with IFN-β induced a similar response, and cluster formation by infection or IFN treatment was dependent upon an intact IFN-signaling pathway. The autophagic …

Mw151 Inhibited Il-1Β Levels After Traumatic Brain Injury With No Effect On Microglia Physiological Responses, Adam D. Bachstetter, Zhengqiu Zhou, Rachel K. Rowe, Bin Xing, Danielle S. Goulding, Alyssa N. Conley, Pradoldej Sompol, Shelby Meier, Jose F. Abisambra, Jonathan Lifshitz, D. Martin Watterson, Linda J. Van Eldik

Sanders-Brown Center on Aging Faculty Publications

A prevailing neuroinflammation hypothesis is that increased production of proinflammatory cytokines contributes to progressive neuropathology, secondary to the primary damage caused by a traumatic brain injury (TBI). In support of the hypothesis, post-injury interventions that inhibit the proinflammatory cytokine surge can attenuate the progressive pathology. However, other post-injury neuroinflammatory responses are key to endogenous recovery responses. Therefore, it is critical that pharmacological attenuation of detrimental or dysregulated neuroinflammatory processes avoid pan-suppression of inflammation. MW151 is a CNS-penetrant, small molecule experimental therapeutic that restores injury- or disease-induced overproduction of proinflammatory cytokines towards homeostasis without immunosuppression. Post-injury administration of MW151 in a …

Pi(4)P Promotes Phosphorylation And Conformational Change Of Smoothened Through Interaction With Its C-Terminal Tail, Kai Jiang, Yajuan Liu, Junkai Fan, Jie Zhang, Xiang-An Li, B. Mark Evers, Haining Zhu, Jianhang Jia

Markey Cancer Center Faculty Publications

In Hedgehog (Hh) signaling, binding of Hh to the Patched-Interference Hh (Ptc-Ihog) receptor complex relieves Ptc inhibition on Smoothened (Smo). A longstanding question is how Ptc inhibits Smo and how such inhibition is relieved by Hh stimulation. In this study, we found that Hh elevates production of phosphatidylinositol 4-phosphate (PI(4)P). Increased levels of PI(4)P promote, whereas decreased levels of PI(4)P inhibit, Hh signaling activity. We further found that PI(4)P directly binds Smo through an arginine motif, which then triggers Smo phosphorylation and activation. Moreover, we identified the pleckstrin homology (PH) domain of G protein-coupled receptor kinase 2 (Gprk2) as an …