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University of Illinois at Urbana-ChampaignMedical Scholars Program
33rd Annual RetreatAugust 24th, 2013
iHotel, Champaign, IL
2013 Retreat
Contents
Director’s Welcome 2
About the Medical Scholars Program 2
Schedule of Events 3
MSP Entering Class of 2013 4
Acknowledgements 6
Outstanding Advisor Award 7
About the Keynote Speaker 9
Past Keynotes 10
About the Alumni and Guest Speakers 12
Student Speaker Biographies and Abstracts 15
Description of Breakout Sessions 21
Poster Abstracts 22
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2013 Retreat
Director’s Welcome
The Medical Scholars Program accepted its first students in 1978. As we beginour 35th year, we gather to celebrate our past and present accomplishments,our 329 graduates and 126 current students. The Annual Retreat is a greatopportunity to learn of the breadth and quality of research being carried outby your fellow students and a chance to informally discuss your experiencesas an MSP — your graduate education, medical education, and future as aphysician/scientist. We have an exciting lineup of both oral presentations andposters. We are particularly pleased to welcome back alumni Hilary Reno,Niranjan Karnik, and Marty Pomper. We are also pleased to have Dr. MelvinBlanchard join us from Wash U.
I want to thank the members of the MSP Annual Retreat Planning Com-mittee, co-chaired by Dan Harris and Aidas Mattis, as well as SA/MSP staffled by Jenni Crum for all of their hard work. I would also like to thank allthose who contributed financially for this special occasion.
Enjoy yourselves!
— Jim Slauch, PhD, Director of the Medical Scholars Program
About the Medical Scholars Program
The MSP is committed to preparing a diverse cadre of physician-scholars to confront the multi-dimensionalproblems and issues that face medicine. The complex nature of these problems requires people trained ina broad array of graduate disciplines working together in order to develop innovative solutions. The MSPhas over 130 MD/PhD, MD/JD, and MD/MBA students pursuing graduate study in over 30 academic dis-ciplines, including the social sciences, humanities, engineering, physical sciences, as well as the biomedicalsciences. With such diverse student perspectives, the MSP provides a unique and electric environment forbright and creative scholars to pursue their passion for combining cutting edge research with individualizedhigh quality clinical training.
Our Annual Retreat, now in its 33rd year, has not significantly changed since its inception. Originallyheld at the Illini Union, this conference began with the objective of bringing the MSP community ofstudents, staff and faculty together to share ideas and insights, and most of all to have fun. Past retreatorganizers have chosen to honor administrators such as Hal Swartz and Tony Waldrop with “roast” videosor slide shows. While each year’s retreat has its own personality, the guiding purpose of hosting an MSP“community of ideas” has remained a steadfast tradition.
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Schedule of Events
Time Event Location
9:30am Check-In FoyerStudent Organizations on Campus
10:15am Welcome and Opening Remarks Illinois A
10:30am MSP Student Research Talks: Illinois A— Paven K. Aujla, PhD— Erich Lidstone, PhD— Acacia C. Lamb, PhDAlumni Speaker: Niranjan Karnik, MD, PhD
12:00pm Lunch Illinois BCPresentation of Outstanding Advisor Award
1:00pm MSP Student Research Talks: Illinois A— Carolina Soto, PhD— David G. Cervantes, PhD— Stefani M. Martin, PhDAlumni Speaker: Hilary Reno, MD, PhD
2:30pm Alumni Panel Illinois A
3:30pm 15-Minute Break (Coffee Available) Foyer
3:45pm Guest Speaker: Melvin Blanchard, MD Illinois A
4:30pm Breakout Sessions:— Q&A with Dr. Blanchard Illinois A— Gearing Up for the Boards: Insider Adviceon Preparing for the USMLE Step 1
Lincoln Room
— MSP Humanities Discussion Alma Mater Room— Ice Breaker and Mixer Foyer
5:15pm Poster Session and Cocktail Hour Quad Room
6:15pm Dinner Illinois BC
7:00pm Keynote Speaker: Martin Pomper, MD, PhD Illinois BC
8:00pm Closing Remarks Illinois BC
Social Activities
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MSP Entering Class of 2013
Erin Allmann Waqar Arif Mariam Bonyadi Carlos DostalEntomology Molecular Molecular Neuroscience
& Cellular Biology & Cellular Biology
Hanna Erickson Spencer Mamer Andrea Palazzolo Eugene ParkMolecular Bioengineering Chemistry Electrical
& Cellular Biology & Computer Engineering
Richard Sanders Marta ZamroziewiczComparative Neuroscience
& World Literature
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MSP Entering Class of 2013
Name Undergraduate Institution Undergraduate MajorGraduate Program
Erin Allmann University of California Global Studies, Aquatic BiologyEntomology at Santa Barbara
Waqar Arif University of Toledo Biochemistry, PhysicsMolecular& Cellular Biology
(Minors: Biology, Mathematics)
Mariam Bonyadi University of California Microbiology, Immunology,Molecular& Cellular Biology
at Los Angeles Molecular Genetics
Carlos Dostal University of Texas, Austin Aerospace EngineeringNeuroscience
Hanna Erickson University of Minnesota, ChemistryMolecular& Cellular Biology
Twin Cities
Spencer Mamer St. John’s University PhysicsBioengineering (Minors: Chemistry, Classics)
Andrea Palazzolo University of Notre Dame ChemistryChemistry (Minors: Science, Technology)
Eugene Park Duke University Mathematics, PhysicsElectrical & ComputerEngineering
(Minor: Chemistry)
Richard Sanders University of Denver Integrated SciencesComparative & WorldLiterature
(Minor: French)
Marta Zamroziewicz Trinity College NeuroscienceNeuroscience
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Acknowledgements
MSP & Student Affairs Administration
Uretz Oliphant, MD James Slauch, PhD James Hall, Ed.D. Nora Few, PhDInterim Dean, Director, MSP Associate Dean, Executive Assistant Dean,
College of Medicine SA & MSP MSP
Jennifer Crum Julie Wyant Barbara Haegele Tenacia GardnerCoordinator, Office Manager, Office Manager, Office Support Specialist,SA & MSP SA & MSP SA & MSP SA & MSP
Planning Committee
Adrienne Barry, Alexander Cerjanic, David Cervantes, Kerim Kaylan, Daniel Harris (co-chair), JenniferHou, Katherine Magerko, Aidas Mattis (co-chair), Alex Parent, Max Rich, Emily Tilmaand
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Outstanding Advisor Award
The role of an MSP advisor brings with it many unexpected challenges. MSP students must balance theirgraduate and medical pursuits and MSP advisors often put in extra effort to understand and guide theirstudents through this lengthy and often stressful process.
In 2000, through an effort to spotlight the significance and continued high quality of faculty mentoring,the MSP Advisory Committee awarded the first MSPAC Outstanding Advisor Awards. Each year since,MSPAC had called for nomination letters and, at the MSP Annual Retreat, recognized those facultymentors whose contributions to our graduate and medical education have been exemplary.
Recipients’ names are displayed on a plaque in the MSP office so that future students will recognizethe outstanding resource provided to us by our mentors. Copies of the written nomination statements areon file in the MSP office.
MSPAC wishes to thank everyone who participated in this year’s Outstanding Advisor Award search,and encourage all interested MSP students to nominate their advisors in coming years.
2013 Outstanding Advisor Award Recipients
Justin Rhodes, PhDPsychology
I had experience with many different types of advisors— throughout my undergraduate years, for my Mas-ter’s, and then as a research tech — and I can hon-estly say Justin Rhodes surpasses them all in termsof his supportiveness and enthusiasm. Justin has thebest qualities a mentor can have — he is easy to ap-proach, honest, continually motivating you to be ex-cited about your research, and teaching you how toask the important follow-up questions.– Martina Mustroph
Sua Myong, PhDBioengineering
She’s taught me to think like a scientist — to thinkcritically, to be updated with the literature, to trou-bleshoot experiments, and to constantly ask the WHYquestion AND to be an engineer — how to apply ba-sic science to solve problems. [. . . ] Without Sua’sdirection in science and life, I would not be where Iam today. I thank her from the bottom of my heartand am forever grateful. I could not have asked fora better advisor.– Helen Hwang
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Previous MSPAC Outstanding Advisor Award Winners
Year Awardee(s) College(s), Department(s), or Division(s)
2012 Stephanie Ceman, PhD Cell & Developmental BiologyClaudio Grosman, PhD Molecular & Integrative Physiology
2011 Philip M. Best, PhD Molecular & Integrative Physiology, Neuroscience,Biophysics, Bioengineering
2010 Brian T. Cunningham, PhD Electrical & Computer Engineering, Bioengineering
2009 Mark S. Micale, PhD HistoryLeslie J. Reagan, PhD History
2008 Richard Tapping, PhD Microbiology
2007 Edward J. Roy, PhD Molecular & Integrative Physiology, Pathology, Neuroscience
2006 Reginald Alston, PhD Community Health
2005 Richard Gumport, PhD BiochemistryEnrico Gratton, PhD Physics
2004 Harris Lewin, PhD Animal SciencesRuth Watkins, PhD Speech & Hearing Sciences
2003 Roberto DoCampo, PhD Veterinary PathobiologyBruce Wheeler, PhD Electrical & Computer Engineering
2002 Martha Gilette, PhD Cell & Structural BiologyJanet Reis, PhD Community Health
2001 Janice Bahr, PhD Molecular and Integrative PhysiologyJohn Katzenellenbogen, PhD ChemistryBruno Nettl, PhD School of Music, Division of MusicologyRobert Rich, PhD College of Law
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About the Keynote Speaker
Martin G. Pomper, MD, PhD
Dr. Pomper was born in Chicago, Illinois, and attended college at the University of Illinois at Urbana-Champaign, majoring in biochemistry and chemistry. Also at Illinois, in the context of the Medical ScholarsProgram, he earned MD and PhD degrees, the latter in organic chemistry. All of his postgraduate medicaltraining was undertaken at the Johns Hopkins Medical School, which included an internship in medicine(Osler Service), residencies in radiology and nuclear medicine, and a neuroradiology fellowship. He iscurrently professor in the Neuroradiology Division of the Department of Radiology at Johns Hopkins. Hisresearch interests involve molecular imaging, particularly of central nervous system processes and cancer.
Forays into Molecular Imaging
Although most clinical diagnostic imaging studies employ anatomic techniques such as computed tomogra-phy (CT) and magnetic resonance (MR) imaging, much of radiology research currently focuses on adaptingthese conventional methods to physiologic imaging as well as on introducing new techniques and agents forstudying processes at the cellular and molecular levels in vivo, i.e., molecular imaging. Molecular imagingpromises to provide new methods for the early detection of disease and support for personalized therapy.Although molecular imaging has been practiced for over 30 years in the context of nuclear medicine, otherimaging modalities have also recently been applied to the noninvasive assessment of physiology and molec-ular events. Nevertheless, there has been sufficient experience with specifically targeted contrast agentsand high-resolution techniques for MR imaging and other modalities that we must begin moving these newtechnologies from the laboratory to the clinic. This brief overview will outline molecular imaging from thedevelopment of targeted agents to clinical translation, with a focus on translational (small animal) andearly clinical imaging. We will discuss the ability for molecular imaging to assess gene expression, and thevarious uses to which that can be put, and provide examples of how existing or readily accessible moleculartracers and techniques can provide insight into rather complex biological phenomena in vivo. A variety oftargets and disease processes will be discussed.
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Past Keynotes
(∗ denotes alumnus)
2012 Charles C. Hardin, MD, PhD∗ Instructor in Medicine, Harvard Medical School; Staff Physi-cian, Division of Pulmonary and Critical Medicine, Mas-sachusetts General Hospital
2011 Michael Milhan, MD, PhD∗ Associate Director, Phyllis Green and Randolph Cowen Insti-tute for Pediatric Neuroscience, New York University ChildStudy Center; Assistant Professor of Child and AdolescentPsychiatry, New York University
2010 Annette K. Schlueter, MD, PhD∗ Associate Professor, Department of Pathology, University ofIowa; Laboratory Medical Director, DeGowin Blood Center;NMDP Apheresis Center Medical Director, University of IowaHealth Care
2009 Keith Cengel, MD, PhD∗ Assistant Professor of Radiation Oncology, Perelman Schoolof Medicine, University of Pennsylvania; Director, Photo-dynamic Therapy Program, Associate Director, Center forAcute Radiation Research
2007 John Chen, MD, PhD∗ Attending Radiologist in the Division of Neuroradiology, De-partment of Radiology, Massachusetts General Hospital
2006 Jaime Feldman, MD, PhD∗ Assitant Professor, Department of Family Medicine andCommunity Health, University of Minnesota
2005 Nora Zorich, MD, PhD∗ Vice President, Global Drug Development and Commercial-ization, Procter and Gamble Pharamceuticals
2004 Michael K. O’Banion, MD, PhD∗ Associate Professor, Neurobiology and Anatomy and Neurol-ogy, University of Rochester Medical Center; Director, Uni-versity of Rochester MSTP
2003 Martin G. Pomper, MD, PhD∗ Associate Professor, Department of Radiology, Johns Hop-kins University; Director, Small Animal Imaging ResourceProgram, Deputy Director, In Vivo Cellular and MolecularImaging Center
2000 James Wilson, MD, PhD Director, Institute for Human Gene Therapy; Professor andChair, Department of Molecular and Cellular Engineering,University of Pennsylvania
1999 Eric Wong, MD, PhD Associate Professor, Departments of Radiology and Psychia-try, University of California at San Diego
1998 Rolf H. Gunther, MD, PhD Vice President, Clinical Research and Development, Centeon
1997 David Trawick, MD, PhD∗ Assistant Professor, Pulmonary and Critical Care Medicine,School of Medicine and Dentistry, University of Rochester
1996 F. Andrew Gaffney, MD Associate Director, Center for Space Physiology andMedicine, Chief of Clinical Cardiology and Professor ofMedicine, Vanderbilt University
1995 Joseph M. Davie, MD, PhD Vice President, Department of Research, Biogen, Inc.; Ad-junct Professor of Microbiology and Immunology, Wash-ington University and Northwestern University School ofMedicine
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1994 Michael K. O’Banion, MD, PhD∗ Associate Professor, Neurobiology and Anatomy and Neurol-ogy, University of Rochester Medical Center; Director, Uni-versity of Rochester MSTP
1993 Thomas Huddle, MD, PhD∗ Assistant Professor of General and Preventive Medicine, Uni-versity of Alabama School of Medicine
1992 Cutberto Garza, MD, PhD Director, Division of Nutritional Sciences, Cornell University
1991 Steven Wartman, MD, PhD Director, Division of Internal Medicine; Professor of Medicineand Community Health, Brown University
1990 Samuel Thier, PhD President, Institute of Medicine, National Academy of Sci-ences
1989 DeWitt Baldwin, MD Director, Division of Medical Education Research and Infor-mation, American Medical Association
1988 Donald Bord, MD Senior Scientist, Brookhaven National Laboratory
1987 Samuel Shem, MD, PhD Psychiatrist ; Instructor, Harvard Medical School; Novelist ;Playright
1986 Timothy Baker, MD, MPH Professor of Health Services Administration, InternationalHealth, and Environmental Health Sciences, Johns HopkinsUniversity School of Public Health; Visiting Professor ofHealth Planning and Management, University of IndonesiaSchool of Public Health
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About the Alumni and Guest Speakers
Niranjan Karnik, MD, PhD
Niranjan Karnik is Associate Professor of Psychiatry, and by courtesy, Nursing at Rush University MedicalCenter. He is board certified in Psychiatry and Child & Adolescent Psychiatry. He completed his under-graduate degree with a major in Anthropology at the University of Pennsylvania. He is a graduate of theMedical Scholars Program at the University of Illinois at Urbana-Champaign where he received his MD andPhD in Sociology with a concentration in Culture, Science & Information. He completed his Psychiatryresidency at Stanford University Hospital, and his clinical fellowship in Child & Adolescent Psychiatry atLucile Salter Packard Children’s Hospital/Stanford University. He also completed a fellowship in ClinicalMedical Ethics from the MacLean Center at the University of Chicago. Prior to moving to Rush University,he served on the faculties at the University of California, San Francisco and the University of Chicago.
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About the Alumni and Guest Speakers
Hilary Reno, MD, PhD
I completed my PhD in entomology in 2000 and my MD in 2002 in the Medical Scholars Program. AtWashington University in Saint Louis/Barnes Jewish hospital, I finished my residency in Internal Medicinein 2005 and my fellowship in Infectious Disease in 2009 after a Chief Residency year during which I was aneditor for the 32nd edition of the Washington Manual of Medical Therapeutics. Currently, I work part-timeas an Instructor in Medicine at Wash U. in both Infectious Disease and Hospitalist Medicine. My interestsare in Sexually Transmitted Diseases, and I am the medical director of the Saint Louis County STD clinic.My clinical research interests involve expanded STD testing in at risk populations, and I just returnedfrom presenting at the STI and AIDS World Congress. As a clinician educator, I help provide STD, HIV,and public health clinical experiences for interns, residents, and fellows, and I developed and direct nightreport.
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About the Alumni and Guest Speakers
Melvin Blanchard, MD
Dr. Melvin Blanchard is chief of the Division of Medical Education, director of the Internal MedicineResidency and associate professor of medicine at Washington University School of Medicine in St. Louis. Hecompleted medical school at the University of Tennessee and residency at Washington University/Barnes-Jewish Hospital, where he served at the Veterans Affairs Medical Center as chief resident during his PGY-3year. After graduation, he joined the faculty at Washington University assigned at the St. Louis VA, wherehe rose to the level of associate chief of medicine. He remained at the VA until becoming director of theInternal Medicine Residency in 2006. Dr. Blanchard has a true passion for teaching. He has facilitatedcareer development of seven cohorts of residents whose interest vary from primary care, research, globalhealth, quality improvement, entrepreneurship, medial education, or a combination of these. He has thricereceived the Distinguished Teaching Service award, awarded by medical students, and has been nominatedfor the Humanism in Medicine award. Dr. Blanchard is also on the council of the Association of ProgramDirectors in Medicine (APDIM), the international organization of accredited internal medicine residencyprograms.
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Student Speaker Biographies and Abstracts
Paven Aujla, PhD
I recently obtained my PhD in Neuroscience from the University of Illinois at Urbana-Champaign in Urbana,Illinois in June 2013. My long-term research interests involve the pathways responsible for proper braindevelopment and investigating translational models of developmental disease to identify therapeutic targets.My doctoral training has allowed me to expand my understanding of the genetic pathways necessary forneuroendocrine development in particular. In my free time I enjoy food, traveling and hiking.
Notch/Rbpjκ signaling regulates progenitor maintenanceand differentiation of hypothalamic arcuate neurons
The hypothalamic arcuate nucleus (Arc), containing proopoiomelanocortin (POMC), neuropeptide Y(NPY) and growth hormone releasing hormone (GHRH) neurons, regulates feeding, energy balance andbody size. Dysregulation of this homeostatic mediator underlies diseases ranging from growth failure toobesity. Despite considerable investigation regarding function of Arc neurons, mechanisms governing theirdevelopment remain unclear. Notch signaling factors such as Hes1 and Mash1 are present in hypothalamicprogenitors that give rise to Arc neurons. However, how Notch signaling controls these progenitor popu-lations is unknown. To elucidate the role of Notch signaling in Arc development, we analyzed conditionalloss of function mice lacking a necessary Notch co-factor, Rbpjκ, in Nkx2.1-cre expressing cells (RbpjκcKO), as well as mice with expression of the constitutively active Notch1 intracellular domain (NICD)in Nkx2.1-cre expressing cells (NICD Tg). We found that loss of Rbpjκ results in absence of Hes1 butnot Hes5 within the primordial Arc at e13.5. Additionally, Mash1 expression is increased, coincident withincreased proliferation and accumulation of Arc neurons at e13.5. At e18.5, Rbpjκ cKO mice have fewprogenitors and show increased numbers of differentiated Pomc, NPY and Ghrh neurons. In contrast,NICD Tg mice have increased hypothalamic progenitors, show absence of differentiated Arc neurons andaberrant glial differentiation at e18.5. Subsequently, both Rbpjκ cKO and NICD Tg mice have changesin growth and body size during postnatal development. Taken together, our results demonstrate thatNotch/Rbpjκ signaling regulates the generation and differentiation of Arc neurons, which contribute tohomeostatic regulation of body size.
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Student Speaker Biographies and Abstracts
Erich Lidstone, PhD
Erich Lidstone has spent the last 5 years working with Prof. Brian Cunningham and the Nano SensorsGroup at UIUC, having recently defended his PhD in Bioengineering. His research is dedicated to theapplication of photonic crystal (PC) biosensors toward high-resolution label-free imaging of cell attachment,growth, and differentiation. Recently developed by Cunningham et al., PC biosensors are uniquely suited toprovide continuous information about cellular activity in the absence of potentially cytotoxic fluorophoresand colorimetric labels. As a member of the Medical Scholars Program, Erich plans to graduate in May2015 and to pursue a research career in diagnostic medicine. While not engaged by extracellular matricesand photonic crystals, Erich enjoys cycling, kayaking, and a variety of mountain sports he picked up whilegrowing up in New Hampshire.
Studying cell attachment with photonic crystal enhanced microscopy
Molecular and cellular mechanics play an integral role in many biologically and clinically interesting pro-cesses, but methods to assess the strength and health of cell attachment remain limited in both scale andthroughput. To address the need for a robust method to assess the density and strength of cell attachment,we have developed Photonic Crystal Enhanced Microscopy (PCEM) — a wide-field, label-free technique de-signed to image cell adhesion. Briefly, PCEM allows direct detection of localized changes as cell attachmentproteins are deposited on photonic crystal (PC) biosensors. We use PCEM to characterize the processesof cell growth, movement, and differentiation as they relate to cell adhesion on a range of substrates, andin context with several cell models. Systems studied include primary cardiomyocytes, mesenchymal stemcells, and hepatic and pancreatic carcinoma cell lines. PCEM provides cell attachment information thatis not available via traditional light microscopy, and as a label-free technique, it can be used to study celland molecular mechanics over prolonged periods in the absence of perturbing or cytotoxic labels, stains,or fluorophores.
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Student Speaker Biographies and Abstracts
Acacia C. Lamb, PhD
Caci grew up in Huntsville, Alabama, and received her Bachelor of Science in chemistry from Emory& Henry College in Emory, Virginia. She enjoys cooking, watching baseball on her porch, and mountains.
New insights into a complex host-pathogen interaction:Mechanisms of helicobacter pylori activation of NF-κB
Helicobacter pylori infection is the main cause of chronic gastritis,gastric ulcers and gastric cancer. Thegram-negative spirochete, which infects more than half of the world’s population, is recognized by theInternational Agency for Research on Cancer as a group 1 carcinogen.The mechanism by which H. pyloriinduces carcinogenesis is believed to be its ability to cause chronic inflammation, creating an environmentsuitable to tumor initiation and progression. Many different strains of H. pylori exist, but those strainsharboring the cag pathogenicity island (cagPAI) have been found to be more virulent, with more carcinomasassociated with infection by these strains. Significantly, higher levels of H. pylori -initiated chronic gastritisis characterized by the cagPAI-dependent up-regulation of proinflammatory cytokines, which are largelymediated by the transcription factor nuclear factor (NF)-κB. The goal of this work is to better definethe bacterial proteins and the cellular signaling molecules involved in H. pylori -induced NF-κB activation.The H. pylori virulence factor CagA, encoded by the cagPAI, is injected into host cells via a type 4secretion system, where it interacts with a number of different signaling pathways leading to inflammationand cell scattering. While a number of these interactions have been defined, the role of CagA in NF-κBactivation and in immune response remains unclear. In this work, CagA is shown to be crucial in theactivation of NF-κB by H. pylori infection. Once inside the cell, CagA utilizes host proteins to induceNF-κB activity. CagA associates with transforming growth factor β-activated kinase 1 (TAK1), a MAPkinase involved in the NF-κB, AP-1 and JNK signaling pathways, and enhances the polyubiquitinationand activation of the kinase. This lysine 63-linked ubiquitination is mediated by E3 ligase tumor necrosisfactor receptor-associated factor 6 (TRAF6) and E2 Ubc13. These findings show that polyubiquitination ofTAK1 regulates the activation of NF-κB, which in turn is used by H. pylori CagA for the H. pylori -inducedinflammatory response.
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Student Speaker Biographies and Abstracts
Carolina Soto, PhD
Carolina Soto completed her BS at the University of Illinois at Urbana-Champaign (UIUC) with dis-tinction in Molecular & Cellular Biology and Biochemistry. She remained at UIUC and in 2005 she joinedthe MD/PhD Medical Scholars Program. As a graduate student in the Neuroscience Graduate Program,she was selected twice as the ISNI fellow (Illinois Summer Neuroscience Institute) to organize and lead theundergraduate summer institute, as well as serve in the Neuroscience PhD program admissions committee.As an MD/PhD student, she has played a leading role in the MSP retreat and the College of Medicineresearch symposiums. As a teaching assistant, she has earned teaching awards from the Molecular andCellular Biology Department and COM.
Her graduate work under the guidance of Dr. Edward Roy and Dr. David Kranz involves the study ofadoptive T cell immunotherapies for the treatment of melanoma and glioma in murine models. Her currentimmunotherapy research focuses on investigating the antitumor effects of genetically engineered high affinity(nanomolar affinity) T cell receptors against the model tumor antigen SIY/Kb (SIYRYYGL). She has wonvarious awards based on her research at cancer symposiums and UIUC-COM research symposiums.
Adoptive T cell therapy with a TCR engineered for nanomolar affinity shows improved anti-tumor efficacycompared to the micromolar wildtype TCR
Clinical studies with immunotherapies for cancer, including adoptive cell transfers of T cells, have shownpromising results. It is now widely believed that recruitment of CD4(+) helper T cells to the tumor wouldbe favorable, as CD4(+) cells play a pivotal role in cytokine secretion as well as promoting the survival,proliferation, and effector functions of tumor-specific CD8(+) cytotoxic T lymphocytes. Genetically engi-neered high-affinity T-cell receptors (TCRs) can be introduced into CD4(+) helper T cells to redirect themto recognize MHC-class I-restricted antigens, but it is not clear what affinity of the TCR will be optimal inthis approach. Here, we show that CD4(+) T cells expressing a high-affinity TCR (nanomolar Kd value)against a class I tumor antigen mediated more effective tumor treatment than the wild-type affinity TCR(micromolar Kd value). High-affinity TCRs in CD4(+) cells resulted in enhanced survival and long-termpersistence of effector memory T cells in a melanoma tumor model. The results suggest that TCRs withnanomolar affinity could be advantageous for tumor targeting when expressed in CD4(+) T cells.
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Student Speaker Biographies and Abstracts
David G. Cervantes, PhD
Dave Cervantes graduated from the University of Iowa in 2006 and earned his PhD in Molecular andIntegrative Physiology in 2011 under Dr. Kevin Xiang. His research focused on cardiac signaling andits role in the progression of heart disease. In his time at the University of Illinois, Dave has made somefriends, won some awards/grants/recognition, has been fairly active at a program, departmental, university,and community level, and has had a great time. Dave plans to graduate in May and will pursue either ageneral surgery or integrated cardiothoracic residency program with aspirations of becoming a pediatriccardiothoracic surgeon. He hopes to pursue clinical research aimed at congenital heart defects and cardiacdevelopment. In his limited free time, Dave enjoys golf, traveling, scuba diving and pugs.
Still my beating heart: Interactions of mice, men and myocardium
Diabetes mellitus (DM) is a growing epidemic, affecting 8% percent of population in the US. DM is awell-characterized risk factor for myocardial infarction, cardiomyopathy and heart failure. Diabetic Car-diomyopathy (DCM) is characterized by both systolic and diastolic dysfunction, resulting in decreasedcardiac function, even in the absence of coronary artery disease (CAD) and hypertension. Interestingly,DCM is associated with hyperinsulinemia and depressed adrenergic signaling leading to decreased con-tractility despite elevated catecholamine levels. The lack of CAD and hypertension in DCM, even in thepresence of elevated catecholamines, suggests that hyperinsulinemia elicits direct cardiomyocyte insult,possibly by modulating adrenergic function. The consequence of signaling interactions within the heart,however, remains largely unknown. My PhD work focused on examining the role of these signaling inter-actions within the heart. Specifically, I studied the role of IR and AR cross-talk in both cardiac functionas well as pathologic cardiac remodeling. First, I characterized a novel signaling complex, containing themitogen-activated IR and the sympathetic activity-regulated β2 adrenergic receptor (β2AR), which mod-ulates insulin signaling leading to cell proliferation, fibrosis and cardiac remodeling. Secondly, I found thatthis complex blunts intracellular transduction of βAR signaling, thus regulating cardiac contractility withinthe heart. My results not only underscore the critical role of signaling cross-talk and integration betweendivergent receptor-mediated signaling pathways in the heart, but this mechanism of IR and βAR signalingcross-talk offers a molecular basis for the broad interaction between these signaling cascades in the heartand may contribute to the pathophysiology of metabolic and cardiovascular dysfunction in insulin-resistantstates.
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Student Speaker Biographies and Abstracts
Stefani M. Martin, PhD
Stefani grew up in Lawrenceville IL. She is married with three step-children. She graduated with aBachelor’s Degree in Biology from Union University in Tennessee. She was accepted into the MSP programin 2004 and joined Joanna Shisler’s lab. She received her PhD in Microbiology in 2011, and is scheduledto graduate with her MD in 2014.
Examination of the role of early viral protein expression in MVA-induced NF-κB activation
NF-κB, a potent pro-inflammatory cellular transcription factor, is an inhibition target for many viruses,including vaccinia virus (VV). However, infection of HEK293T cells with the attenuated Modified VacciniaVirus Ankara (MVA) no longer inhibits NF-κB activation, due to the absence of various immunosuppressivegenes in this strain. By blocking steps of the virus life cycle, we identified that early viral genes must beexpressed to allow for MVA-induced NF-κB activation. We assayed a VV plasmid library and identifiedseveral early viral gene products that activated NF-κB when expressed independent of infection. One ofthe genes capable of activating NF-κB when expressed ectopically was the C11R product (vaccinia growthfactor; VGF). When C11R was siRNA silenced during an infection, MVA-induced NF-κB activation wasreduced. Silencing of C11R also inhibited MVA-triggered ERK1/2 phosphorylation, an upstream eventrequired for NF-κB activation in MVA-infected cells. Infection with MVA∆C11R, a MVA deletion mutantvirus lacking C11R, no longer induced ERK1/2 phosphorylation, and NF-κB activation was moderatelydecreased. This trend held when the viruses infected human keratenocytes, HaCaT, indicating the C11Rprotein product modulates viral-induced NF-κB activation in multiple cell types. Presumably, the C11Rproduct interacts with the epidermal growth factor receptor (EGFR) to activate NF-κB. In support of this,the presence of AG1478, an EGFR inhibitor, resulted in reduced levels of ERK1/2 and NF-κB activationin MVA-infected cells.
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Description of Breakout Sessions
Gearing up for the Boards:Insider Advice on Preparing for the USMLE Step 1
Are you starting M2 this fall? Are you an M1 or pre-M1 that wants to to know how M1 classes can helpyou prepare for Step 1? Mark and Lindsey will discuss how to prepare for the exam, what study helpsare available to aid your preparation, and answer your questions about the USMLE Step 1. This is themost important test we take as medical students. Residency programs use these scores as major criteria insorting and ranking applicants. Come get your questions answered and enjoy interacting with your fellowMSP students.
Q&A with Melvin Blanchard, MD, FACP, Director, Internal Medicine ResidencyProgram, Washington University in St. Louis
As a follow-up to his immediately preceding talk, Dr. Blanchard will take questions from students interestedin internal medicine and its subspecialties. Come get your answers concerning what opportunities areavailable to MD/PhD’s in medicine, and find out what residency programs are looking for in a competitivecandidate. This is a great opportunity to interact directly with a program director from one of the bestresidency programs in the nation.
MSP Humanities Discussion
The Medical Scholars Program at the University of Illinois Urbana-Champaign is one of the eleven MD/PhDprograms in the country to offer fields of study in the Medical Humanities and Social Sciences (MHSS).It also happens to be among the largest of such programs. Students studying or interested in fields suchas sociology, history, anthropology, philosophy, comparative literature, economics, law, communications,business, community health, and human & community development are invited to discuss ideas for eventsand future directions of the MHSS student group. Dr. Karnik, who received his MD/PhD in sociology,will be helping to facilitate this discussion.
Ice Breaker and Mixer
The Ice Breaker breakout session is an opportunity for the first year students to meet the returning MSPstudents in a structured, but fun, way. Take advantage of this opportunity to meet some new people inthe program and to learn more about the people you already know.
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Poster Abstracts
Polyphosphate inhibitors function as novel antithrombotic agents in mouse models ofthrombosis
Richard J. Travers1 and Jim Morrissey11Department of Biochemistry
Inorganic polyphosphate (polyP) is widely present in biology. The discoveries that polyP is secreted from activatedhuman platelets and that it potently modulates coagulation and inflammation have led to a recent burst of interestin this ancient molecule regarding its roles in human pathophysiology. Our lab has found that polyP polymersof the length found in platelets can accelerate the “propagation” phase of clotting, as well as being incorporateddirectly into the formed fibrin clots. We have also identified multiple cationic polymers that can block polyP-mediated enhancement of coagulation in vitro. In order to tests the effectiveness of these compounds in vivo, weused two mouse models of pathological thrombus formation, ferric-chloride induced thrombosis in the carotid artery,and laser-induced thrombosis in mouse cremaster arterioles. PolyP inhibitors were able to significantly increase thetime to occlusive thrombus formation in injured carotid arteries and to decrease the accumulation of fluorescentlylabeled platelets and fibrin in injured cremaster arterioles. Thus, we believe that the polyP inhibitors used in thesestudies can serve as precursors to a novel class of antithrombotic agents that specifically antagonize polyP-mediatedcoagulation. Also, because polyP seems to act as a general accelerant and to be more important for the propagationpathological clot formation, we believe that they will have less serious bleeding side effects compared to conventionalantithrombotic agents, all of which target essential enzymes within the coagulation cascade. This would allow formore aggressive antithrombotic treatment in individuals at risk for myocardial infarction or ischemic stroke becauseof the reduced danger of bleeding, which is currently the most dangerous side effect in the management of thromboticrisk in patients.
Estradiol but not equol enhances place learning in middle-aged female rats:Relationship to site-specific Erk activation
Samantha L. Pisani1, Steven L. Neese1,2, Susan L. Schantz1,2, and Donna L. Korol1,31Neuroscience Program 2Department of Comparative Biosciences
3Department of Biology, Syracuse University, Syracuse, NY
Estradiol improves memory for some hippocampus-sensitive tasks, such as place learning, throughout the lifespan.Classical and membrane-associated estrogen receptors (ERs) localize to the hippocampus, suggesting that genomicand/or membrane-initiated signaling mediate cognitive enhancements. Several studies indirectly link estradiol-induced ERK activation with improvements in hippocampus-sensitive memory by focusing on increases in ERKphosphorylation measured apart from performance. However, systemic treatment with estrogens impacts structuresinvolved in other cognitive strategies, e.g., the striatum, and may shift relative ERK activation according to thecontributions of each neural system during learning. Based on prior results with the isoflavone genistein, we proposethat estrogens modulate patterns of ERK activation where the hippocampus is initially primed with increased pERK,facilitating place learning, followed by attenuation of hippocampal pERK levels as the striatum dominates task per-formance after acquisition. In the current study, middle-aged rats were ovariectomized and treated with estradiol orthe soy isoflavone metabolite equol 48 and 24 h before place task training. The cognitive effects of phytoestrogensare of interest due to their selective ER binding profiles; equol binds ERβ with high selectivity but induces littleclassical transcription activity. Following training, hippocampal and striatal ERK activation were examined throughquantitative Western blotting. Estradiol enhanced place learning while equol had no effect. Preliminary biochemi-cal data demonstrate that estradiol treatment induced lower hippocampal ERK activation relative to the striatum,suggesting a shift to ‘habit’ in rats that acquired the task quickly. These findings point to a cellular mechanism bywhich signaling through different ERs alters cognition according to actions in discrete memory systems.
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2013 RetreatIdentifying neuropeptides induced by exposure to a cocaine-associated context and
exercise in male C57BL/6J mice
Martina L. Mustroph1,2,5, Sarah E. Dowd1,4, Elena V. Romanova1,4,Jonathan V. Sweedler1,4,5, Chessa N. Kilby1, Justin S. Rhodes1,3,51Beckman Institute 2College of Medicine 3Department of Psychology
4Department of Chemistry 5Neuroscience Program
It is known that wheel running can facilitate extinction of conditioned place preference (CPP) for cocaine if runningoccurs after conditioning. However, mechanisms underlying CPP extinction from running are unknown. Given thatthe hippocampus and amygdala play an important role in contextual conditioning, it is reasonable to hypothesize thatneuroadaptations from running in these regions underlie the rapid extinction of CPP. We investigated whether accel-erated extinction of cocaine CPP is associated with altered expression of neuropeptides in hippocampus or amygdalaof C57BL/6J mice using Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) in conjunction with Principal Component Analysis (PCA) and Liquid Chromatography-ElectrosprayIonization-Mass Spectrometry (LC-ESI MS). Using a neuropeptidomics approach to identify known and novel neu-ropeptides that interact with running and cocaine reward may facilitate development of effective treatments to helpmaintain abstinence from drug addiction.
TLR10 is a global suppressor of TLR-induced pro-inflammatory gene activation.
Song Jiang1, Xinyan Li1, Richard Tapping11Department of Microbiology
Through direct sensing of bacterial, fungal or viral components Toll-like receptors (TLRs) activate intracellularsignaling events that drive the cellular expression and release of immune mediators. These activation events notonly induce inflammatory processes, but also initiate and orchestrate the longer term protective responses of theadaptive immune system. Despite a decade of research and tens of thousands of publications on TLRs, the biologicfunction of TLR10 has remained unknown. In efforts to uncover a signaling function for TLR10 we generated vectorcontrol and stable TLR10 expressing cells by retroviral transduction of the human myelomonocytic U937 cell line.To determine the effect of TLR10 on TLR mediated activation, we performed a quantitative PCR array experimentwhich surveyed 84 proinflammatory cytokines, chemokines, transcription factors and acute phase proteins in ourU937 cell lines following lipopeptide activation of TLR2. These data showed that the stimulation of RNA messagefor a number of the inflammatory genes, including IFN-beta and IL-6, was significantly reduced in TLR10 expressingcells compared to vector control cells. No effect on cell viability was observed in any of the cell lines either beforeor after stimulation. Surprisingly, TNF-alpha and IL-6 release induced by a variety of TLR agonists, includingthose for TLR2, TLR3 and TLR4, were also greatly suppressed in the TLR10-U937 line but remained robust inthe vector control U937 cells showing that the suppressive effect of TLR10 extends to other members of the TLRfamily. This effect appears specific for TLR signaling pathways as TNF-induced proinflammatory signaling was notaffected in these cells. Additionally, a bioassay using ISRE-L929 reporter cells reveals suppressed secretion of Type IInterferon in TLR10-expressing cells. Transient transfection of HEK cells shows that TLR10 inhibits MyD88-inducedNF-kB activation as well as TRIF-induced activation of an IFN-beta promoter. Lastly, an investigation of canonicalMAPK signaling pathways revealed suppressed agonist-induced phosphorylation of ERK, JNK, and p38. Theseresults suggest that human TLR10 acts to regulate pro-inflammatory signaling and cytokine production and pointto TLR10 as unique among TLRs as a global suppressor of TLR-induced activation.
VE-cadherin mechanotransduction in lung endothelial cells
Adrienne K. Barry1,2, Ning Wang3, and Deborah .E. Leckband2,4,5
1College of Medicine 2Department of Biochemistry 3 Department of Mechanical Science and Engineering 4
Department of Chemical and Biomolecular Engineering 5 Department of Chemistry
Rationale: Dysfunctional regulation of endothelial adherens junctions is the direct underlying cause of vascular leakand pulmonary edema in acute lung injury. Indirect evidence suggests that cytoskeletal rearrangements are linkedto adherens junction remodeling, but there is no clear demonstration that adherens junction proteins play an activerole in the regulation of intracellular or extracellular mechanical tension. Here I investigate mechanotransduction(response to applied force) of VE-cadherin, the main structural protein at adherens junctions, and how this regulatesglobal cell contractility and cytoskeletal remodeling both locally and globally. Methods: Mechanical responses in
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2013 Retreathuman pulmonary artery endothelial cells were studied using magnetic twisting cytometry experiments, in whichshear stress was exerted on specific cell surface receptors by twisting magnetized beads bound to the cell surface.Remodeling of adherens junctions and F-actin in response to mechanical force was visualized by immunofluorescence.Results: Application of mechanical stress to VE-cadherin receptors revealed force-dependent stiffening of VE-cadherin junctions with increasing applied stress. Treatment with cytoskeletal inhibitors significantly diminishedthis response. When a constant magnitude of shear stress was applied continuously over time, VE-cadherin junctionsincreased stiffness, suggesting active junction reinforcement. Confocal microscopy revealed force-actuated changesin both local and global cytoskeletal organization, as well as local rearrangements at both bead-cell and cell-celljunctions. Conclusions: These data provide direct evidence that VE-cadherin complexes are tension sensors, andthat associated mechanotransduction regulates global cell mechanics. This suggests a novel mechanism regulatingendothelial monolayer integrity. Here I present data that show that cadherin-dependent adhesions throughout thecell monolayer form a mechanically coupled network that regulates the endothelial barrier in response to force.
Elucidating an anesthetic-induced gating transition in ligand-gated ion channels
Mark J. Arcario1,2 and Emad Tajkhorshid1,2,3,4
1Center for Biophysics and Computational Biology 2College of Medicine 3Department of Biochemistry 4BeckmanInstitute for Advanced Science and Technology
General anesthetics have, arguably, been one of the most important advances in modern medicine. Yet despite wellover a century of research, the mechanism of general anesthesia is still poorly understood, although the moleculartarget of these drugs has recently been discovered. Recent crystal structures of bacterial homologues with anestheticsbound has made the problem more tractable to molecular dynamics. However, the lack of a widely available andreliable set of parameters for common anesthetics has impeded progress. Utilizing the standard CHARMM scheme,we have parameterized four commonly used modern anesthetics, namely desflurane, isoflurane, sevoflurane, andpropofol. The generated parameters agree well with experimental bulk (density, ∆Hvap) and solvation (∆Gsolv
in water and in oil) properties. In order to better understand how these anesthetics interact with membranes, wecalculated the free energy profile for inserting each anesthetic into a POPC membrane utilizing the umbrella samplingmethod as well as flooding simulations to characterize any perturbations to the membrane itself. All anesthetics showa distinct preference for the headgroup or interfacial region of the membrane, with negligible free energy differencesbetween bulk solution and the membrane core. Using the parameters developed, we also simulated the interactionof desflurane and propofol with GLIC. In both cases, the anesthetic spontaneously releases from its binding site andexits the protein via the membrane in a reproducible manner. Additionally, “flooding” simulations, in which a largenumber of anesthetics are randomly placed in aqueous solution around the protein, reveal a pathway common tobinding and unbinding. Several bulky residues at the membrane interface force the anesthetic to climb a 4 kcal/molenergetic barrier in order to bind and unbind the protein. In both cases, asymmetric anesthetic binding causes asubtle conformational change which induces pore constriction and dehydration, preventing the passage of ions.
Control of endolysosomal flux by the guanine nucleotide exchange factor Mon1 andthe Tor dependent localization of the lipid modifying enzymes Pah1 and VPS34
Gus Lawrence1,2, Christopher Brown2, Blake Flood2, Rutilio Fratti21College of Medicine 2Department of Biochemistry
Cells have evolved to make molecular decisions based upon the need to maintain cellular and organismal home-ostasis. This drive has shaped the evolution of cellular signaling circuits. The necessity of a cell to maintain itsplasma membrane and avoid the harsh realities of the second law of thermodynamics while exercising judicioususe of its metabolic stores is integrated in the lysosome of eukaryotes. Lysosomes control cell membrane integritythrough membrane fusion, sense and control cellular metabolism via the Tor complex, and regulate autophagy. Inhumans, this mechanism of maintenance of homeostasis has evolved to strongly influence the Wnt, Notch, and Torsignaling systems. The endolysosomal system is used to establish morphogen gradients in the developing embryoand regenerating tissue. Altered endolysosomal flux is implicated in aberrant activation of the immune response inautoimmune diseases such as lupus. Here, I describe the regulation of endolysomal flux by Rab GTPase recruitmentand activation by the Guanine Nucleotide Exchange Factor (GEF) Mon1. These results are examined in relation tohow metabolism affects endolysosomal flux via the Tor dependent localization of the lipid modifying enzymes Pah1and VPS34.
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2013 RetreatPrimary myoblasts demonstrate an improved ability to form myotubes and
neuromuscular junctions
Max Rich1, Min Kyung Lee1, Marni Boppart2, Hyunjoon Kong11Department of Chemical and Biomolecular Engineering
2Department of Kinesiology and Community Health
Understanding the development of neuromuscular junctions will be helpful both towards being able to control biobotsand in beginging to be able to treat spinal cord injury, spinal muscular atrophy, and muscular dystrophy. Wefound that the co-culture of primary murine skeletal muscle cells and a murine motor neuron cells line made itpossible to make neuromuscular junctions that stained positive for acetyl choline receptor, a physiological marker forneuromuscular junction formation.
Regulation of retinoic acid signaling in lens regeneration
Alvin G. Thomas1, Jonathan J. Henry1
Department of Cell and Developmental Biology
The frog Xenopus laevis can regenerate a removed ocular lens de novo from its cornea. The series of molecularevents that underlie this process are still unclear, and their illumination will enrich our understanding of humantissue regeneration and homeostasis. Regeneration of the lens in Xenopus begins when molecular signals from theneural retina contact the cornea epithelium, triggering a new lens to form from the corneal tissue. Retinoic acid (RA)is a morphogenic molecule that is involved heavily in vertebrate body patterning, and in many cases of regeneration.Here we examine what role RA might play in the regeneration of the vertebrate ocular lens. Expression patterns ofthe RA-synthesizing enzyme RALDH, and the RA-metabolizing enzyme CYP26 were observed in various eye tissues.Further, an inhibitor of CYP26 and a CYP26-resistant RA analog were used to determine that CYP26-mediatedattenuation of RA signaling within the cornea may be necessary for lens regeneration to occur.
Porcine reproductive and respiratory syndrome virus (PRRSV) causesneuroinflammation and cognitive impairment in neonatal piglets
Monica R.P. Elmore1, Michael D. Burton1, Matthew S. Conrad1, Jennifer L. Rytych1, Rodney W. Johnson1
1Department of Animal Sciences
Due to similarities in human brain structure and growth, swine are a valuable animal model to investigate theimpact of environmental insults on neurodevelopment. The present study evaluated the impact of PRRSV infectionon central and peripheral indicators of inflammation in neonatal piglets, as well as cognitive performance in ahippocampal dependent spatial T-maze task. At 1-wk of age, piglets were inoculated intranasally with PRRSV (P;n=11) or phosphate-buffered saline (C; n=8). Throughout the study, body weight, rectal temperature, and sicknessbehaviors were collected daily. At 2-wk of age, piglets were trained (acquisition phase: 60-s trials, 10 trials per dayfor 8 days) to locate a chocolate milk reward in a constant place and location using extra-maze visual cues in aclear T-maze. During the reversal phase (60-s trials, 10 trials per day for 3 days), the correct reward location foreach piglet was reversed and the piglets were re-tested to asses learning and working memory. Following behavioraltesting, all piglets were euthanized (approximately 4 weeks of age) for tissue sample collection. Microglial cells wereisolated from the hippocampus and stained with antibodies to confirm cell type (CD11b and CD45) and indicate cellactivation (MHC II), which were measured using flow cytometry. PRRSV infected piglets had a higher average dailytemperature (P: 102.52 ± 0.08oF vs. C: 100.54 ± 0.09oF; P ¡ 0.0001), were less likely to consume their first mealeach day (P < 0.0001), and had lower average daily body weights at the end of the study (P = 0.0022) comparedto control piglets. Maze performance during acquisition was impacted by treatment (P = 0.003), with PRRSVpiglets taking longer to reach performance criterion (80% correct) than controls (day 8 vs. 4, respectively). Thiseffect was primarily due to reduced performance by PRRSV females on days 4 through 8 of acquisition comparedto controls and PRRSV males (all comparisons, P < 0.05). However, there was no effect of treatment or sex onmaze performance during the reversal phase of testing (P = 0.766). Flow cytometry revealed that PRRSV infectedpiglets had significantly higher levels of activated microglia (43.18 ± 5.91%) compared to controls (2.52 ± 6.93%;P = 0.0003). Gene expression data is currently being collected to measure pro-inflammatory cytokine expressionin the periphery and brain. Thus far, these data demonstrate that piglets infected with PRRSV exhibit cognitiveimpairment in a spatial T-maze task and a significant increase in activated microglia cells in the hippocampus. Thisheightened neuroinflammatory response may underlie the cognitive deficits observed following PRRSV infection.
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2013 RetreatDetermining the genetic and molecular basis of plague resistance in Balb/cJ mice
Michael Tencati1,2, Joshua Turner1, Richard Tapping11Department of Microbiology 2College of Medicine
Yersinia pestis is the causative agent of bubonic, septicemic, and pneumonic plague. This pathogen subverts theimmune response of its host by several different mechanisms which include modification of surface LPS, suppressionof phagolysosome acidification and oxidative burst, and the inhibition of phagocytosis and inflammatory signaling.Despite this diversity of virulence mechanisms some hosts resist infection in a heritable manner. A classic F1 crossof offspring from the resistant Balb/cJ strain and the susceptible C57BL/6 strain led to the discovery of a dominantresistance locus in Balb/cJ mice that localized to chromosome 17. Subsequent experiments have narrowed the regionfurther, with resistance appearing to localize to a 7cM region between 47.4-57.4 Mbps of chromosome 17. Congenicstrains which possess this region within a susceptible C57BL/6 background exhibit significantly lower bacterial loadsin the spleen and liver 1-2 days after i.v. infection with Y. pestis compared to littermate C57BL/6 mice. This lowerbacterial load correlates with the ability of these mice to survive when subjected to a lethal dose. Due to this earlydifference in bacterial load, we hypothesized that there may be a difference in the ability of early responder cells tokill Y. pestis in the different mouse strains. The results of in vitro isolated cell experiments indicate that neutrophils,but not macrophages, of Balb/cJ mice can differentially control Y. pestis growth. Mice containing this region arecurrently being bred with C57BL/6 mice in order to generate offspring with novel crossovers within the 7cM regionand further define the required gene(s).
Palmitic acid induces anxiety-like behavior and neurotransmitter alterations
Morgan L. Moon1, Marcus A. Lawson2, Jennifer J. Joesting3,Gabriel S. Chiu1, Stephen J. Gainey3, Gregory G. Freund1,3,4
1Division of Nutritional Sciences 2Department of Neuroscience3Department of Animal Sciences 4Department of Pathology
Short-term high fat diets have been shown to induce cognitive deficits, anxiety-like behaviors and brain region-specific neurotransmitter alterations in mice, independent of overt inflammation. To determine the role of free fattyacid signaling and elucidate the mechanism behind these changes, we utilized a novel method of free fatty acidadministration. Intraperitoneal administration of palmitic acid (C16:0) induces a decrease in locomotor activity(LMA) at 2 h that recovers by 24 h after injection. Upon resolution of LMA, palmitic acid treated animals exhibitanxiety-like behavior, as demonstrated by reductions in both exploration of a novel object and time spent in theopen arm of the elevated zero maze. Examination of neurotransmitter levels in brain regions reveals an change in5-hydroxyindoleacetic acid (5-HIAA) levels in the amygdala, resulting in a shift in the ratio of serotonin to 5-HIAA.Regional enzymatic activity of monoamine oxidase demonstrates no difference in palmitic acid treated animals versuscontrols, suggesting a different mechanism is responsible for the alteration of 5-HIAA levels. These results indicatethat palmitic acid induces anxiety-like behavior that is associated with neurotransmitter alterations in the amygdala.
Physiologically relevant concentrations of 17β estradiol stimulate gene transcriptionand proliferation of breast and ovarian cancer cells
Mathew Cherian1, David Shapiro1
1Department of Biochemistry
We propose an alternate paradigm for ERα action in which only a small fraction of estrogen receptor α (ERα)needs to be ligand bound with 17β-estradiol (E2) to elicit important biological effects. Most studies indicate theKD for binding of E2 to ERα is in the 1 nM range and most researchers use concentrations of E2 in the nanomolarrange. However, clinical data indicates that much lower concentrations of circulating estrogens in the blood ofpostmenopausal women strongly increases their risk of developing breast cancer. To evaluate the effect of these lowconcentrations of E2 on proliferation of breast and ovarian cancer cells, we identified conditions in which proliferationof ERα containing MCF-7 and T47D breast cancer cells and BG-1 ovarian cancer cells is completely dependent uponaddition of E2 to the medium. Under these conditions, very low concentrations of E2, likely to occupy only avery small fraction of the ERα, are sufficient to elicit near-maximal proliferation of the ERα (+) cell lines. Lowconcentrations of E2 also induce proliferation and the formation of 3 dimensional colonies in soft agar assays. The ERantagonists TPSF and ICI 182,780 block induction of cell proliferation by low concentrations of E2; indicating that E2
induction of cell proliferation is through ER. We also observed that these low concentrations of E2 efficiently induce
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2013 Retreattranscription of some known ER target genes, including pS2 and PSR. In contrast, some other E2-ERα regulatedgenes require nanomolar concentrations of E2 for induction. This data demonstrates wide variation in the fractionof ERα that must be liganded in order to regulate expression of different ER regulated genes. These observationsare important in understanding the important effect of E2 concentration on the ERα-regulated transcriptome andunderstanding the effects of endogenous estrogens and xenoestrogens in cancer.
A D-amino acid-containing neuropeptide discovery funnel
Itamar Livnat1, Hua-Chia Tai1, Stanislav Rubakhin2, Jonathan V. Sweedler21Department of Molecular and Integrative Physiology 2Department of Chemistry
It has been established that proteins (and thus, their peptide products) are ribosomally translated using only L-aminoacids, and so it was assumed that D-amino acids did not naturally exist in animal peptides. However, physiologicalD-amino containing-peptides (DAACPs) do exist, first identified in frogs, resulting from a post-translational modifi-cation: peptide isomerization. But because they have no associated mass shift, DAACPs are historically very difficultto identify, causing a gap in mass spectrometry-driven peptide characterization studies. The objective of the proposedwork aims to bridge this gap by developing tools to detect DAACPs by taking advantage of their unique properties,including their resistance to degradation by peptidases. In addition, formation of a DAACP alters the shape of apeptide, which can change its ability to bind to a receptor. This is especially important for neuropeptides, cell-cellsignaling molecules that are bioactive by binding to their cognate receptor. Thus, the tools to identify DAACPs willbe developed using neuropeptides from a simpler model animal, where one DAACP has already been identified. Thissystem of DAACP discovery involves chiral analysis: breaking down an endogenous neuropeptide into its componentamino acids and assaying those amino acids for their chirality using analytical chemistry methods. The long-termobjective of this work is to identify functional DAACPs in the mammalian nervous system. In spite of intensivestudy, more than 100 human G-protein coupled receptors have no known binding partner. DAACPs may explain,in part, the discrepancy between the number of neuropeptides known through genomic and peptidomic studies andthe large number of orphan receptors. Neuropeptides will also be studied for peptide isomerization in the contextof the suprachiasmatic nucleus (SCN), a hypothalamic group of neurons with a known role in circadian rhythms.The SCN is targeted because there are extensive studies on time of day release of neuropeptides, and a number ofpeptidase-resistant peptides have already been identified in the SCN. This work is significant because sleep disordersas having a link to drug abuse, so the implication of an overlooked PTM can result in many missed neuropeptidefunctions in our sleep/wake cycles.
The activational mechanisms underlying the impact of estrogen on the formation andexpression of circadian rhythms in mice
Sara E. Royston1, Athanasios G. Kondilis2, Steven V. Lord2,Norio Yasui3, John A. Katzenellenbogen3, Megan M. Mahoney4
1Neuroscience Program 2Department of Cellular and Molecular Biology3Department of Chemistry 4Department of Comparative Biosciences
Estrogenic signaling shapes and modifies circadian rhythms, the disruption of which have been implicated in psy-chiatric, neurologic, cardiovascular, and metabolic disease, among others. While the impact of estrogen on totalactivity, free running period, photic phase response, activity phase angle, and the ratio of activity in the light vs.the dark (LD ratio) has been documented, the exclusively activational molecular mechanisms underlying these phe-nomena remain poorly characterized. To determine the activational impact of estrogen on daily behavior patternsand differentiate between the roles of ESR1 and ESR2, the primary CNS estrogen receptors, within this context,ovariectomized adult female mice were chronically administered estradiol (E), the ESR1 agonist propylpyrazole triol(PPT), the ESR2 agonist diarylpropionitrile (DPN), or cholesterol (CTL). Animals were singly housed with wheels in12:12 LD or total darkness (DD), and wheel revolutions were recorded in 10 min bins. E administration significantlyincreased average daily activity compared to CTL. This effect was partially mimicked by chronic PPT, but not DPNadministration, suggesting a role for ESR1, but not ESR2 in the regulation of total activity. Further, we found thatE or PPT treatment consolidates activity to the dark phase, reducing the LD ratio compared to CTL. Interestingly,selective ESR2 stimulation increased the LD ratio even beyond that observed in CTL animals. Together, these datasupport dichotomous roles for ESR1 and ESR2 in activity consolidation across 24 hr. PPT, DPN, or E reducedthe phase angle of activity onset, suggesting that ESR1 and/or ESR2 activation is sufficient for advancing the onsetof activity following the transition from L to D. Similarly, the active period (alpha) was longer in animals housed
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2013 Retreatin DD and treated with PPT, DPN, or E than age and litter-matched CTL animals. Conversely, the subjectiveday (tau) was shorter in animals administered PPT or E, but not DPN, suggesting that ESR1 activation alone isresponsible for the known effect of estrogen-dependent shortening of tau. Finally, we assessed behavioral shifts inactivity onset following 1 hr light pulses at various times throughout the subjective day. When pulsed in the earlysubjective night but no other time, activity onset was advanced in animals treated with E, PPT, or DPN comparedto CTL, suggesting that ESR1 or ESR2 activation is sufficient to elicit a phase response. Importantly, we show thatestrogen has strong activational effects on the temporal patterning and expression of circadian behavior, and thatthese effects are due to distinct mechanisms elicited by ESR1 and ESR2 activation.
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