The Medical I.B.I.S., Issue 2, 2014

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Spring 2014 | The Medical I.B.I.S.

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From our Dean

From our Editors

CAMPUS

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am proud to present the second issue of The Medical I.B.I.S., the Miller School of Medicine’s student-produced research publication, which showcases the innovative research conducted by our extraordinary students.

Research is the lifeblood of academic medicine. Discoveries in our laboratories advance prevention, diagnosis, treatments and cures for the diseases and conditions that afflict humankind. They also advance what is taught in our classrooms, because medical students – just like practicing physicians – must have access to the latest knowledge. Under the guidance and mentoring of our faculty, our students take their first important steps in the career to which they have been called.

The breakthrough research presented in this issue is truly impressive. It spans a wide range of interests, including stem cell treatments, spinal cord injuries, retinal diseases, genetic markers, and much more. Our students are just entering the field of medicine, yet they are already making significant contributions to medical knowledge. We know there will be more great work to come.

Pascal J. Goldschmidt, M.D. Senior Vice President for Medical Affairs and Dean University of Miami Miller School of Medicine CEO, University of Miami Health System 2

The Medical I.B.I.S. | Spring 2014

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e are proud to present the second issue of The Medical I.B.I.S., a publication authored, produced, reviewed, and edited entirely by medical students. This magazine is dedicated towards promoting the scientific achievements of University of Miami Miller School of Medicine medical students, featuring research projects in both basic medical science and clinical studies.

These students at the Miller School have taken an active role in innovative research and will certainly shape the future of medicine as they embark on their professions as physicians.

Selected through an internal peer review process, these research projects are just seventeen of the many admirable accomplishments that our students have achieved both on our Miller campus and at other institutions across the country. We know that these students’ commitments to research can lead to novel medical advancements and we encourage them to continue pushing the boundaries of medical knowledge

Angela Chang Editor-In-Chief

sg.mededu.miami.edu/medicalibis

sg.mededu.miami.edu/medicalibis

Richa Taneja Managing Editor

Melissa Stone Senior Editor

Spring 2014 | The Medical I.B.I.S.

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CAMPUS

university of miami’s medical student research publication

Editor-In-Chief Angela Chang Managing Editor Richa Taneja

MICHAEL KRITZER 6 Anchored p90 Ribosomal S6 Kinase 3 is Required for Cardiac Myocyte Hypertrophy

Senior Editor Melissa Stone Selection Committee Chair Matthew Phillips

The Medical I.B.I.S. Staff 2014.

KAITLIN YOUNG 8 Characterization of Fragile X Syndrome Caused

by FMR1 Deletions

Section Editors Laura Huang Devon Cohen Amir Tarsha Caroline Chen Kevin Moore Writers Laura Bloom Le Zhong Jeffrey Smith Houda Boucekkine Sapir Karli Gabriel Nemzow-Weingrod Andrew Richardson Selection Committee Matthew Field Michael Durante Jeanna Harvey

DARRYL CANNADY II 10 Surrogate Fitness Measures Association with Functional Independence in Spinal Cord Injuries Selection Committee

Section Editors

INNA GRANOVSKY 12 STD Clinic Patients’ Awareness of Non-AIDS Complications

Publishing Editor Nahim Dewan Production Editor James Greenwood Photographers Nikesh Doshi Jonathan Parker Cover Wei Yang

KATYAYINI ARIBINDI 13 Cholesterol and Glycosphingolipids Profiles of Human Trabecular Meshwork and Aqueous Humor

Writers

Interm Faculty Advisor Alex J. Mechaber, M.D.

JARED GANS 14 Plasmacytoid Dendritic Cells Induce Regulatory T-cells that can Prolong Cardiac Allograft Survival

Advisory Board Pascal Goldschmidt, M.D. Alex J. Mechaber, M.D. The Medical I.B.I.S. is published by the University of Miami Miller School of Medicine Student Government. We reserve the right to edit any submissions, solicited or unsolicted, for publication.

This magazine is the work of University of Miami medical students, and the University of Miami is not responsible for its contents. Perspectives expressed by authors do not necessarily reflect the opinions of the University of Miami. We retain the right to reprint contributions, both text and graphics, in future issues as well as a non-exlcusive right to reproduce these in electronic form. The Medical I.B.I.S. welcomes comments and feedback. Please send questions and comments to medical.ibis@gmail.com.

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The Medical I.B.I.S. | Spring 2014

JOSHUA PARKER 11 Evidence of Acceleration Aging in Individuals with Spinal Cord Injury

LUCAS CAVALLIN The Quest to Cure Kaposi Sarcoma

Photographers Jonathan Parker (left) and Nikesh Doehi (right) Not pictured: Michael Durante, James Greenwood, Sapir Karli, Melissa Stone, and Amir Tarsha. sg.mededu.miami.edu/medicalibis

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MICHAEL SCHOOR 19 Bioluminescence Energy Capture by Quantum Dot ARASH SAYARI 20 Photograph-Based Goniometry: A Comparison of Techniques SPENCER SUMMERS 22 Neuropathic Pain-Induced Depression and TNF LINSEY LINDLEY 24 LBH Role in Normal and Neoplastic Mammary Stem Cell Control ZACHARY GERSEY 25 Curcumin Treatment Promotes Glioblastoma Stem Cell Death JAMIE DIAMOND 26 Insurance Implications for Choice of Stent Type AUDREY COX 28 Stem Cell Particles Promote Development of New Blood Vessels in the Healing of Chronic Wounds SHARON WOLFSON 30 Effect of Colon Transection on Spontaneous HighAmplitude Propagating Contractions

NIKESH SHAH 18 Effect of AMPK Activator in the Treatment of Retinal Tumors sg.mededu.miami.edu/medicalibis

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CAMPUS p90 Ribosomal S6 Anchored Kinase 3 is Required for Cardiac Myocyte Hypertrophy

BY MELISSA STONE

measurement of myocyte growth while the ANF levels were a physiologic correlate. Michael used this framework to test a number of different conditions in order to identify the key RSK3 domains involved in the signal transduction of through mAKAP. When they over-expressed the RSK-binding domain of mAKAP, it competed with the interaction between RSK3 and mAKAP, successfully inhibiting myocyte hypertrophy in vitro.

The next step for Michael was to determine relevance in vivo.

Using knock-out mice, he employed three methods to induce hypertrophy and elucidate the roles of RSK3 and mAKAP in cardiac hypertrophy: trans-aortic constriction, chronic isoproterenol infusion, and swimming. Trans-aortic constriction is a surgical procedure that models aortic stenosis and chronic pressure overload. Chronic isoproterenol infusion models the high catecholamine state of heart failure by increasing cardiac output. Lastly, having the mice swim served to physiologically stress the heart. Once the mouse becomes stressed, the mouse’s organs were measured and the heart tissue was stained to assess growth and microscopic measurements of myocyte size.. Messenger RNA levels and protein levels and modification were also analyzed. Michael’s results confirm that both RSK3 and mAKAP are required for cardiac myocyte hypertrophy.

“Under standing how cel l biology changes from Michael working at his lab bench.

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hen Michael Kritzer, Ph.D. was a secondyear medical student at the Miller School of Medicine searching for the perfect laboratory to complete his graduate thesis for the M.D./Ph.D. program, he sought a basic science project with translational implications. Michael Kapiloff, M.D., Ph.D., Director of the Cardiac Signaling Transduction and Cellular Biology Laboratory and Professor of Cardiology at the Interdisciplinary Stem Cell Institute (ISCI), had a project for Michael that exemplified bench to bedside: identifying signal transduction pathways involved in cardiac myocyte hypertrophy – a major risk factor for heart failure.

Desiring to apply a strong foundation in basic science towards the development of a therapeutic agent, Michael used in vitro and in vivo models to identify cardiac hypertrophic signaling.

Signal transduction pathways are a complicated meshwork of proteins that bind and modify each other to activate or inhibit their downstream signaling. Dr. Kapiloff ’s lab specializes in understanding how the scaffold protein mAKAP (muscle 6

The Medical I.B.I.S. | Spring 2014

A-Kinase Anchoring Protein) facilitates pro-hypertrophic signaling. The RSK family of proteins is involved in cellular growth and Dr. Kapiloff had previously published that “RSK” was associated with mAKAP. To determine the RSK isoform involved in mAKAP-based myocyte growth, Michael performed recombinant expression of different binding proteins with various mutations. Michael sought to determine which protein binding domains were essential for this signaling node. He discovered that the binding of RSK3 to mAKAP was an essential step in myocyte hypertrophic signaling.

For his in vitro work, Michael partnered with Research Assistant Professor Jinliang Li, Ph.D., who cultured neonatal rat cardiac myocytes and exposed them to various agents that stimulate growth. This was done in the presence of small interfering RNA – small molecules specifically designed to silence certain RNA molecules – as well as various chemical inhibitors to identify proteins involved in cell growth. They mainly employed two different assays: cell surface area and atrial natriuretic factor (ANF) measurements. Cell surface area provided a clear physical sg.mededu.miami.edu/medicalibis

phys i o l og y to pathophysiology is the key to reversing those changes.”

Michael plans to pursue a career in academic medicine, aspiring to run a lab for basic science research while also seeing patients and performing translational clinical research. In particular, he believes, “My future career in academic medicine will be largely formed on an important concept I learned during my Ph.D.: collaboration.”

Michael was eating lunch one day in the Stem Cell Institute’s lounge, casually discussing his research with Jonathan Hertz, a Ph.D. student analyzing the retina and glaucoma in the lab of Jeffrey Goldberg, M.D., Ph.D., associate professor of ophthalmology. Michael had a revelation: what if they applied his sg.mededu.miami.edu/medicalibis

Michael Kritzer, Ph.D. Degree Program: M.D./Ph.D. Expected Graduation: 2015 Mentor: Michael Kapiloff, M.D., Ph.D. Honors: Presented at the American Heart Association 2011 Scientific Sessions; Published in Circulation Research (PMID 22997248), Journal of Molecular and Cellular Cardiology (PMID 21600214), American Journal of Physiology: Heart and Circulatory Physiology (PMID: 23913705); Funded by American Heart Association Pre-Doctoral Fellowship; Awarded Best Oral Presentation at the M.D./ Ph.D. Annual Research Symposium 2013 Activities: Ethics & Humanities Pathway, M.D./Ph.D. Scientific and Professional Developmental Committee, ESRF Judging Committee, Music Ensembles for the Enrichment of Medicine Future Goals: Academic medicine research to the work being done in the Goldberg lab? In the heart, cell growth is harmful but in the eye, cellular growth of retinal ganglion cell axons could save someone’s vision. Michael and Jonathan approached their mentors and after promising preliminary results from experiments over the next several days, the two labs jointly applied and later received a R01 NIH grant.

Michael credits his revelation to ISCI Director Joshua Hare, M.D., who designed the layout of the building to foster such dynamic collaboration.

Michael’s work culminated with his Ph.D. thesis and part of this project was published in Circulation Research in 2013.

Michael received an American Heart Association (AHA) predoctoral fellowship as funding for his work and presented the preliminary data at the AHA 2011 Scientific Session. He was also awarded Best Oral Presentation at the 2013 M.D./Ph.D. Annual Research Symposium and his mentor, Dr. Kapiloff, received the University of Miami Micah Batchelor Award based on the research involved in this project. The Kapiloff lab also filed a patent for the use of the RSK-binding domain as a pharmaceutical intervention for the inhibition of hypertrophy and prevention of heart failure.

Though Michael has moved on to his clinical years as a part of the M.D. program, he continues to collaborate with members of his lab, who are furthering his research to see if his in vitro results that utilized the over-expression of RSK-binding domain can be replicated in vivo to inhibit mouse cardiac hypertrophy. Michael believes that his research has the potential to greatly influence the management of hypertrophy – either in hypertrophic cardiomyopathy, a leading cause of sudden death in young athletes, or in heart failure, a leading cause of death in the adult population. Future implications of Michael’s research could save countless lives.

Spring 2014 | The Medical I.B.I.S.

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CAMPUS Characterization of Fragile X Syndrome Caused by FMR1 Deletions

BY HOUDA BOUCEKKINE

My heart was with the patients and I knew I wanted to do research directly with them.” “

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ragile X is the most commonly inherited form of intellectual disability in males as well as the most common single gene mutation known to cause autism. The specific gene responsible is the FMR1 gene, which is typically silenced by the expansion of CGG trinucleotide repeats seen in Fragile X. This causes a deficiency in the Fragile X Mental Retardation Protein (FMRP), leading to the physical, intellectual, and behavioral manifestations of this disease. However, there have been cases of patients with the typical Fragile X phenotype who lack the CGG expansion; these individuals were found to have microdeletions of the culprit gene, resulting in the same lack of FMRP seen with the CGG expansion. In her case study, Kaitlin Young describes three such cases.

The case study consisted of a collaboration involving three patients treated at specialty Fragile X clinics. Physicians at these centers, including Kaitlin’s mentor, Deborah Barbouth, M.D., have been collecting information regarding these three children.

Initially, they all presented with the Fragile X phenotype, but tested negative when the diagnostic tools for Fragile X—southern blot and PCR amplification—were administered. Once a chromosomal microarray was performed, the microdeletions were detected as the underlying cause.

Under the direction of Dr. Barbouth and genetic counselor Abigail Rupchock Deppen, M.S., C.G.C., Kaitlin organized the data for these patients and helped write the case study, in which she characterized the patients’ symptoms, developmental delays through childhood, and physical features. Kaitlin described all of the testing that the children went through, placing emphasis on the detection of chromosomal deletions via microarray.

Kaitlin explains that these cases illustrate the importance of incorporating chromosomal microarray into genetic testing, particularly for situations in which the etiology is not detected by other tools. These cases provide further support for the use of the microarray becoming the gold standard to determine genetic abnormalities underlying intellectual disability, autism, and other disorders without an apparent cause. Kaitlin further notes that early diagnosis of Fragile X is critical in order to provide adequate interventions and medical treatment.

Kaitlin began working on this project in June 2013, during the start of her third year at Miller, and presented her work at ESRF this past February. Her involvement with basic science research in the field of autism began before attending medical 8

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school. Once she was accepted to the Genetics Pathway of Emphasis during her first year, she contacted Dr. Barbouth and became involved in a clinical drug trial for Fragile X patients at The South Florida Fragile X Clinic. Through this experience, Kaitlin met many Fragile X families and awareness groups around South Florida, and she has continued her involvement with the clinic, including frequent shadowing.

Kaitlin presented the South Florida Fragile X Clinic poster at the International Fragile X Conference in Miami last summer and has participated in other volunteer activities involving Fragile X and autism. Through her endeavors, she has seen the abilities of dedicated individuals to come together to raise awareness and support for a common cause—something that she finds genuinely heart-warming.

As for future plans, one of Kaitlin’s main goals is to stay involved with the Fragile X Clinic and work closely with the “sweet and amazing” children, as she describes them. Kaitlin and her mentors are also in the process of looking for more patients with Fragile X in other clinics across the country to expand the case study. She plans to spread awareness about genetic testing once she becomes a physician, in the hopes that more patients will benefit. In terms of her career, she is currently considering pediatric neurology, but she plans to incorporate genetics into her practice regardless of her specialty. As for now, she enjoys working closely with kids at the clinic whenever her busy school life permits.

Kaitlin Young Degree Program: M.D. Expected Graduation: 2015 Mentor: Abigail Deppen, M.S., C.G.C.; Deborah Barbouth, M.D. Honors: Poster at the International Fragile X Conference 2012; Poster presentation at ESRF 2014 Activites: Genetics Pathway of Emphasis, South Florida Fragile X Clinic Volunteer, DOCS Project Manager, Caring Hearts, Pediatric Interest Group, Genetics Student Interest Group, Academic Societies Trainer Future Goals: Pediatrics, neurology, or genetics Spring 2014 | The Medical I.B.I.S.

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CAMPUS Surrogate Fitness Measures Association with Functional Independence in Spinal Cord Injuries

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Darryl Cannady II Degree Program: M.D. Expected Graduation: 2016 Mentor: Jochen Kressler, Ph.D. Honors: Presented at ESRF 2014, American College of Sports Medicine Conference 2014 Activities: President of Student National Medical Association, DOCS Future Goals: Orthopedics or sports medicine The Medical I.B.I.S. | Spring 2014

BY LE ZHONG

BY ANDREW RICHARDSON

ith an undergraduate degree in exercise physiology and his eye on a residency in orthopedic surgery, Darryl Cannady II hoped to focus his research on patients with spinal cord injuries (SCIs). Darryl found what he was looking for in the lab of Mark Nash, Ph.D., part of the Miler School’s Miami Project to Cure Paralysis.

Under the mentorship of Jochen Kressler’s, Ph.D., he began working on surrogate fitness measures of aerobic capacity and anaerobic power.

Aerobic capacity and anaerobic power are two key measures of fitness, which are typically assessed via peak oxygen consumption (VO2peak) and the Wingate protocol, respectively. In patients suffering from chronic SCIs, research has demonstrated that fitness is related to increased functional independence.

Functional independence can be thought of as a person’s ability to perform activities of daily living (ADLs). What most consider mundane ADLs, like showering, going to the bathroom, or moving from room to room, are often enormous challenges for someone suffering from a SCI. Looking to find a less expensive alternative to the VO2peak and Wingate exams, Mark’s laboratory initiated a project to create their own measures to predict functional independence.

They developed the 6-minute (6mPT) and 30-second (30sPT) push tests to assess aerobic capacity and anaerobic power, respectively. The design of these tests is intentionally simplistic.

To run them, you need a 15 meter hallway, 2 cones and a stop-

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Evidence of Accelerated Aging in Individuals with Spinal Cord Injury

Darryl with his lab group at the Lois Pope Life Center. watch. In these tests, the wheelchair-bound patient is asked to push her/himself as far as possible in either 6 minutes or 30 seconds. The total distance traveled by the patient determines their surrogate fitness scores.

After analyzing the data, Darryl found that the 6mPT and 30sPT scores showed a distinct relationship with the spinal cord independence measure (SCIM). The results suggested that their surrogate measures could provide predictive power for functional independence in patients who depend on wheelchairs as their primary mode of ambulation. Darryl pointed out that the lab might use the 6mPT and 30sPT to observe the efficacy of SCI treatments over time. The hope is that the patient’s surrogate fitness scores will continue to rise and that this trend will correlate with improved SCIM scores.

Darryl believes that his work has provided him with both a deeper understanding for the care of SCI patients, and the gratification that comes along with medical research. “Watching the community support each other is inspiring, they can see the sg.mededu.miami.edu/medicalibis

Joshua with Dr. Rachel Cowan in Lois Pope Life Center.

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s a first year student at the Miller School, Joshua Parker wanted to combine his interest in genetics and his career aspiration in orthopedic spine surgery into a research project. He joined the Dr. Rachel Cowan’s lab at the Miami Project to Cure Paralysis where he began researching the possibility of DNA biomarkers for accelerated aging in individuals with spinal cord injury (SCI).

Current research suggests that individuals with SCI tend to age at a faster rate than the general population. While previous studies have shown correlations such as increased prevalence of chronic diseases, higher mortality rates, and reduced lifespans for individuals with SCI, there is a lack of molecular evidence to corroborate these findings.

Dr. Cowan and her team postulate that mean telomere length sg.mededu.miami.edu/medicalibis

is negatively correlated with SCI. Telomeres are repeated DNA sequences at the ends of chromosomes that cannot be fully copied when a cell replicates its DNA prior to dividing. As a result, telomeres shorten after each round of cell division and eventually prohibit the cell from dividing further, ultimately leading to cell death. Joshua’s project aimed to see if telomere length was shortened in SCI individuals.

Joshua hit the phones in the hopes of enrolling volunteers for the new study. For each participant, a blood sample, cheek swab, and a few lifestyle surveys were taken. DNA was analyzed to determine the telomere for its single copy gene ratio (T/S), a measurement of the telomere length relative to the entire chromosome. So far, the study has collected the T/S ratio for eight SCI individuals and eight normal controls matched for age, gender, race, and smoking status.

The data show that while the average T/S ratio was smaller in SCI individuals than in the controls, the results were statistically insignificant. Joshua cites logistical limitations of the study such as a relatively small sample size and the ability to only look at one biomarker as potential reasons for the statistical insignificance.

Joshua’s research to identify biomarkers for increased aging in SCI individuals will hopefully improve the lives of individuals with SCI through more effective, preventative screening in the future. Joshua’s favorite part of the project has been the “opportunity to work firsthand with paralyzed individuals and seeing how determined they are to live a normal life despite the obstacles.” Joshua believes that his and his lab’s work will someday allow individuals with SCI to achieve the same goals as the rest of the non-disabled population with fewer obstacles than they face in their day-to-day lives now.

Joshua Parker Degree Program: M.D. Expected Graduation: 2016 Mentor: Rachel Cowan, Ph.D. Honors: Presented at ESRF 2014 Activities: Genetics Pathway of Emphasis, Genetics Interest Group, Orthopedics Interest Group, Deans Cup, Flag Football Future Goals: Orthopedic spine surgery Spring 2014 | The Medical I.B.I.S.

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CAMPUSPatients’ Awareness of STD Clinic Non-AIDS Complications

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BY SAPIR KARLI

uman immunodeficiency virus (HIV) infects many types of cells, including the immune system. The natural history of this infection leads to severe immunodeficiency (AIDS) that is almost always fatal. Although current therapies (antiretroviral therapy or ART) have significantly increased the life expectancy of people living with HIV/AIDS, infections with this virus should not be taken lightly. Mortality rates associated with HIV infection and opportunistic infections have decreased, however, the risks of conditions non-traditionally associated with HIV, as well as the costs and long-term effects of ART, remain a concern.

Inna Granovsky decided to take action and spread awareness that HIV/AIDS is still a formidable threat to individuals and society. She took the initiative to plan and conduct research at the Miami-Dade County Health Department Sexually Transmitted Diseases Clinic. Under the mentorship of Dr. Jose G. Castro, M.D., she conducted a research project that aimed to create a better understanding of the magnitude of what it means to acquire an HIV infection as a high-risk individual. She also worked to promote the continuation of these preventative methods by educating members of the community about complications unrelated to AIDS that HIV-infected individuals often face.

The purpose of the study was to obtain pilot data about awareness of non-AIDS complications and self-perceived HIV risk in STD patients in South Florida. Inna performed a crosssectional survey evaluating patients’ knowledge of non-HIV/ AIDS associated conditions such as cognitive implications,

Inna Granovsky Degree Program: M.D. Expected Graduation: 2016 Mentor: Jose G. Castro, M.D. Honors: Infectious Diseases Society of America ERF Medical Scholars Program, ID Week 2013, Approved for publication in the Journal of Therapy and Management in HIV Infection Activities: DOCS, Anatomy Rose Ceremony, SunSmart 5K Run/Walk, Health Law Pathway of Emphasis Future Goals: Undecided 12

The Medical I.B.I.S. | Spring 2014

Cholesterol and Glycosphingolipids Profiles of Human Trabecular Meshwork and Aqueous Humor

BY SAPIR KARLI

Katya working with the mass spectrometer. cardiovascular disease, and premature aging. The questionnaire additionally assessed how important it is for subjects to utilize HIV preventative methods.

It was found that only a third of patients viewed themselves as being at risk of acquiring HIV, even though more than half of the participants had a sexually transmitted disease in the past.

Most patients were under the perception that HIV can be fully treated with ART and were not aware of HIV-associated conditions that current medications cannot easily treat. However, after educating these patients on the prevalence and importance of non-HIV complications, a vast majority demonstrated apprehension regarding HIV acquisition.

The study showed that a brief informational session could increase patient willingness and dedication to using new biomedical strategies to prevent HIV infection. By spreading awareness, the new perception that HIV is a fully treatable disease with few associated risks may be modified. Inna hopes to use the data gathered from this study in a preventative manner to spread awareness regarding existing complications of HIV infection, even with current antiretroviral therapies. By sharing this knowledge with the community, she hopes to shift the focus from relying on life-prolonging therapies towards more preventative care. Inna hopes to combine her research experience and clinical career to become the best doctor and researcher she can be. sg.mededu.miami.edu/medicalibis

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laucoma is the second leading cause of blindness worldwide. The disease refers to a group of ocular pathologies that lead to increased intraocular pressure and associated optic neuropathy secondary to optic nerve damage. Vision loss starts at the periphery and slowly progresses to centrally. Therefore, symptoms occur when the disease is unfortunately already quite advanced. Though understanding the specific pathologic process underlying glaucoma can contribute to the creation of novel treatments, the physiological and mechanical changes that occur have not yet been previously explored. Katyayini Aribindi is hoping to contribute to the field by conducting research at the Bascom Palmer Eye Institute.

Under the mentorship of Dr. Sanjoy Bhattacharya, M.S., M. Tech., Ph.D, she explored the lipid content in glaucomatous and non-glaucomatous eyes as part of an ongoing collaboration between Dr. Bhattacharya and Dr. Richard Lee, M.D., Ph.D. Katyayini’s interest in conducting research in ophthalmology began in high school when she shadowed a glaucoma specialist.

As an undergraduate at UM, her advisor introduced her to Dr. Bhattacharya who provided her with the opportunity to be a part of his research lab. Katyayini views her role in the laboratory not only as an opportunity to aspire to achieve her goals, but sg.mededu.miami.edu/medicalibis

also as a chance to use her capabilities to contribute to medicine.

The purpose of Katyayini’s research project was to determine the differential profiles of cholesterol and glycosphingolipid species, as well as their quantitative differences, between control and glaucomatous aqueous humor (AQH) and the trabecular meshwork (TM) samples derived from human donors. Katyayini quantified cholesterols and glycosphingolipids in the samples using a mass spectrometer and then analyzed their spectra using MZmine 2.9 and in house macros. Her favorite part of conducting this project was using the mass spectrometer, which she views as “a beautiful collaboration between computer science, physics, biology, organic chemistry, and biochemistry.”

Katyayini found that control and primary open angle glaucoma (POAG) samples had a high percentage of cholesterol and glycosphingolipid species in common with both AQH and TM samples. However, there were several species that were specific to either the POAG or to the controls. The results suggest that the progression of glaucoma correlates with an accumulation of a unique cholesterol in AQH – the mechanism of which remains to be further elucidated.

Katyayini hopes that her research will set the stage for future projects to continue characterizing the specific changes that occur in the cholesterol and glycosphingolipid species of glaucoma patients. This will hopefully further aid in the discovery of novel treatment methods.

While she enjoys ophthalmology, Katyayini is keeping an open mind about which specialty she would ultimately like to practice.

Regardless of which field she will enter, she plans on continuing to participate in research in hopes of improving the quality of life of affected people through discoveries in medicinal science.

Katyayini Aribindi

Degree Program: M.D. Expected Graduation: 2017 Mentor: Sanjoy Bhattacharya, M.S., M. Tech., Ph.D Honors: Presented at ARVO 2012 (PMID: 23790057) Activites: Medical Humanities Club Future Goals: Undecided Spring 2014 | The Medical I.B.I.S.

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CAMPUS Dendritic Cells Induce Plasmacytoid Regulatory T-cells that can Prolong Cardiac Allograft Survival

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BY ANDREW RICHARDSON

elected as a prestigious Sarnoff Cardiovascular Research Fellow, Jared Glans, Class of 2015, decided to dedicate a year to research after his third year at the Miller School. Aiming to explore his dual interest in surgery and immunology, Jared sought out a laboratory that would not only allow him to test hypotheses at the bench, but also gain exposure to surgery and translational medicine. After interviewing at several hospitals across the country, the lab of Joren Madsen, M.D., D.Phil., Director of the Massachusetts General Hospital Transplant Center, stood out from the rest. Jared began his one-year fellowship in Boston in July of 2013.

Jared explained that “the biggest problem of current organ transplants in humans is that it is extremely difficult to pre-

vent organ rejection and even when we can prevent it, there is great morbidity and mortality from the immunosuppressive medications.” Successfully inducing tolerance in human transplants is the “holy grail” of transplantation research. Tolerance is defined as the absence of a destructive immune response to a transplanted tissue without ongoing immunosuppression.

Jared’s project focuses on developing a method to achieve just that in heart transplants.

Jared is working to further characterize how certain immune cells, specifically regulatory T cells and plasmacytoid dendritic cells (pDCs), affect immune tolerance and long-term organ acceptance in mice. His co-mentor, Alessandro Alessandrini, Ph.D, along with Dr. Madsen, showed that regulatory T-cells and pDCs play a pivotal role in building tolerance to the transplanted

Jared Gans working at the FACS machine at the Massachusetts General Hospital Transplant Laboratory.

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“Taking a year off from medical school to

devote my time solely to research has greatly expanded

my scientific acumen and will

prove invaluable to my future career.” mouse kidneys. Jared’s project applies that same mechanism to mouse heart transplants. He has hypothesized that pDCs are an important player in the induction of regulatory T-cells. To test this hypothesis, Jared first took pDCs and exposed them to naïve T-cells and various cytokines in culture. The pDCs induced the T-cells to create Foxp3+ (a marker of regulatory T-cells) T-cells.

He then took the Foxp3+ T-cells and tested them for suppressive activity. Using flow cytometry to track proliferation of T effector cells, Jared discovered that his in vitro-induced Foxp3+ T-cells prevented the proliferation of other T-cells. These results confirmed Jared’s original hypothesis and he is currently working on replicating the data in cultured non-human primate cells.

Jared’s in vitro data correlates with his in vivo studies as well.

For this component of his research, Jared took his cultured Foxp3+ T-cells and injected them into mice prior to heterotopic heart transplantation. The results showed a statistically significant prolongation of the allograft heart survival in the experimental mice.

Concurrently, Jared is involved with Dr. Madsen’s non-human primate studies on thoracic organ transplants. Utilizing cotransplantation of a kidney or thymus with bone marrow transplantation, Jared has attempted to induce tolerance to cardiac and lung transplants in Old World cynomolgus monkeys. For the first time, these complex regimens have proven successful in primates. He spends much of his time helping with the care of the monkeys, planning primate studies, and assisting surgical operations. The goal for both primate studies and Jared’s mouse research is to find a clinically translatable model for cardiac allograft acceptance in humans.

Jared has submitted an abstract to the World Transplant Congress and presented at this year’s ESRF. The Sarnoff Research Fellowship, a program in which twelve medical students are selected each year to pursue a project of their choice, funds Jared’s research. The program has been established for over thirty years and is dedicated to life-long mentorship of its members. Jared is the first medical student from the Miller School to sg.mededu.miami.edu/medicalibis

be selected for the fellowship. Dean Pascal Goldschmidt, M.D., Nanette Bishopric, M.D., and Joshua Hare, M.D., are the only other members of the Sarnoff Foundation at the Miller School.

With a plan to pursue a career in academic medicine, Jared believes that his research year will provide him with a strong foundation in basic science and translational research. His nuanced scientific understanding of immunological tolerance is applicable to many fields of medicine, including the one that Jared is most interested in, otolaryngology. He believes that insights into immunological processes are crucial to new discoveries in otolaryngology – including facial transplants, allergic rhinitis, and head/neck cancer.

Long-term immunological tolerance remains an unmet goal of modern medicine, but Jared’s research has elucidated some of the underlying mechanisms that bring the profession one step closer. His project continues to work towards a clinically translatable model for heart transplantation acceptance in humans.

Jared Gans Degree Program: M.D. Expected Graduation: 2015 Mentor: Joren Madsen, M.D., D.Phil.; Alessandro Alessandrini, Ph.D. Honors: Sarnoff Cardiovascular Research Fellow 20132014; Oral presentation at the ESRF 2014; Submitted to World Transplant Congress 2014; Submitted to Harvard Surgery Research Day Symposium 2014 Activites: Alpha Omega Alpha, President of American Medical Student Association, Co-coordinator MD/MPH gross anatomy program, Assistant Logistics Director for DOCS, Secretary CaneShare, Academics Coordinator for Laennec Future Goals: Otolaryngology Spring 2014 | The Medical I.B.I.S.

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CAMPUS The Quest to Cure Kaposi Sarcoma

BY GABE WEINGROD-NEMZOW

“

I truly love translational research and I’m going to do my best to help patients by combining my medical and scientific backgrounds,” says Lucas Cavallin Ph.D, currently in his second year at Miller School. Lucas is researching Kaposi’s Sarcoma (KS), a cancer that is caused by Kaposi Sarcoma Herpes Virus (KSHV, also known as Human Herpes Virus 8). His goal is to understand the altered survival pathways in the KSHV infected cells and exploit this pathway to produce a specific anti-cancer therapy.

KS is a cancer of the cells that line the circulatory system (endothelial cells) and forms blue-purple patches and plaques in the skin, mouth, intestines, and lungs. “KS has the color of a bruise”, says Lucas, “because of the angiogenesis [blood vessel formation] caused by the blood vessel tumor.” KS is particularly prevalent in AIDS patients. Treatment of KS involves the use of drugs that do not specifically target KS, such as anti-retroviral therapy and non-specific and highly toxic cancer drugs.

Lucas found a survival pathway that can be disrupted to kill KS tumor cells in a less toxic manner. “Normally, cancer cells are addicted to a few pathways that promote cell proliferation and survival, so by targeting these pathways we could disrupt the oncogenic process. We wanted to identify a survival pathway for KSHV so we could develop specific therapies which would be less toxic than our current non-specific drugs.”

Lucas and his colleagues in Dr. Enrique Mesri’s lab at the Sylvester Cancer Center and the Miami Center for AIDS Research, along with Pascal J. Goldschmidt M.D., Dean of the Miller School of Medicine, created a mouse model of KS as part of his doctoral thesis at the Microbiology and Immunology Graduate Program of UM before starting medical school. They infected KSHV in endothelial lineage progenitor stem cells,

Lucas Cavallin, Ph.D. Degree Program: M.D. Expected Graduation: 2016 Mentor: Enrique Mesri, Ph.D.; Pascal Goldschmidt, M.D. Honors: Sylvester Cancer Center Research Poster Competition Winner 2013; Florida Medical Association’s Annual Poster Symposium 2013; Alving Award Winner, ESRF 2014 Activities: DOCS Public Relations Manager Future Goals: Academic Medicine

16

The Medical I.B.I.S. | Spring 2014

which were hypothesized to develop into the natural target cells for KSHV in humans. Lucas then injected these cells into adult immunocompromised mice and produced KSHV sarcomas. Using this model, Lucas has now identified a specific oncogenic pathway for KS. Using data from mouse and human KS tissues, Lucas performed microarray analysis to sample thousands of messenger RNAs at once. He found that both human and mouse KS expressed high levels of the tyrosine kinase receptor (RTK) platelet derived growth factor receptor -α (PDGFRα)and the proteins that activate it. Although these cells have two PDGFR subtypes (α and β), Lucas had evidence that only the α subtype was implicated in KS. To determine if this cellular receptor drove the cancer, Lucas performed directed phosphoproteomics, a screening technique that detects activated RTKs. It was found that the only RTK that was significantly over expressed in the mouse model of KS was PDGFRα. To verify the phosphoproteomic study in humans, Lucas used immunohistochemistry, a technique used to label proteins, with histological sections supplied by Dr. Paolo Romanelli, a dermatopathologist at UMMSM and found active PDGFRα.

Lucas hypothesized that this receptor was the driving mutation for KS and that possible anti-cancer treatments could be tailored using this altered survival pathway.

Lucas’s next goal was to understand how the virus activates the receptor. KSHV is a complex virus with 90 genes. 14 of these genes were pirated from humans, and all 14 are associated with oncogenesis and angiogenesis. Lucas decided to focus on the viral G-protein coupled receptor (vGPCR) because his lab showed that it is essential in KS oncogenesis and angiogenesis.

He found that vGPCR activates oxidative signaling pathways that lead to the production of the ligands for PDGFRα.

Following this discovery, Lucas attempted to suppress the PDGFRα pathway using two different strategies. The first strategy was to prevent the PDGFRα oncogenesis (which is activated by oxidative pathways) by using N-acetylcysteine (NAC). NAC is a safe anti-oxidant most commonly used in acetaminophen overdoses to detoxify the liver. The other strategy was to suppress all of the PDGFR pathways with a drug called Imatinib, which blocks intracellular signaling through RTKs like PDGFRα, by preventing its activation. It is already used for treating chronic myelogenous leukemia, gastrointestinal stromal tumors, and several other rare tumors. Lucas performed in vitro and in vivo studies of the KS mouse model using both NAC and Imatinib to suppress the PDGFRα signaling, and sg.mededu.miami.edu/medicalibis

Lucas (left) with Sachin Gupta Ph.D., M.B.A. (right), and Santas Rosario checking endothelium-derived KSHV-infected cells under the microscope.

“I’m going to do my best to help patients by com bining my

medical

and

scientific backgrounds.” found that there was a significant reduction in tumor growth with NAC and Imatinib.

The only caveat to the Imatinib experiment is that Imatinib affects all the PDGFR subtypes. To prove that Imatinib inhibited oncogenesis only through the PDGFRα pathway, Lucas performed target validation: he harvested the tumors and performed Western blots to determine the protein levels of sg.mededu.miami.edu/medicalibis

activated PDGFRα. The data showed a reduction in PDGFRα, indicating that the PDGFRα needs to be activated in KS. Lucas was still unsatisfied with just proving the involvement of PDGFRα by using a drug trial. To conclusively verify the driving pathway was PDGFRα, Lucas devised a genetic experiment. Lucas and his associates genetically created KSHVinfected cells that expressed a non-functional PDGFRα, called a dominant negative PDGFR α mutant. This mutation would knock-out only one step in the intracellular signaling cascade, making it a more specific experiment than the Imatinib and NAC testing. Lucas found that the dominant negative PDGFRα mutant failed to produce tumors.

By affecting only one gene in the host, Lucas had nearly completely inhibited oncogenesis, which supports the hypothesis that PDGFRα pathway is oncogenic in KS. Because of his work, mankind now has a specific pharmacologic target in the fight against KS. Lucas hopes to look for more potent small molecule drugs that will be more effective in blocking the PDGFRα pathway and thus help to develop specific and more effective anti-KS drugs.

Spring 2014 | The Medical I.B.I.S.

17

EffectCAMPUS of AMPK Activator in the Treatment of Retinal Tumors

Bioluminescence Energy Capture

by Quantum Dot

BY JEFFREY SMITH

BY LE ZHONG

Nikesh in front of the Bascom Palmer Eye Institute.

R

etinoblastoma is a cancer that develops from the retinal cells at the back of the eye. It forms from the immature retinal cells in the eyes of children as a result of underexpression of the tumor suppressor gene, RB1, and can rapidly lead to blindness if it is not treated. Although retinoblastoma has one of the best cure rates of childhood cancers, there is room for improvement of treatment since the current treatment procedures of chemotherapy and radiation can lead to significant morbidity.

If the tumors become advanced they can be chemoresistant leading to high failure rates in treatment. These tumors often have regions of hypoxia which causes these cells to become dependent upon anaerobic glycolysis for energy production.

Biochemical changes generated in these hypoxic cells could be utilized as a target for therapeutic retinoblastoma treatment.

When Nikesh Shah, a second-year student at the Miller School, started his search for a research project he knew he wanted to work in either an ophthalmologic or oncologic field. Fortunately for him, he found a project under the supervision of Dr. Timothy Murray, M.D., M.B.A., F.A.C.S, formerly Professor of Ophthalmology and Ocular Oncology at UMMSM, at Bascom 18

The Medical I.B.I.S. | Spring 2014

Palmer Eye Institute which combined his interests. Nikesh was further motivated by interacting with children diagnosed with retinoblastoma, knowing that his research could potentially change their treatment and improve their lives.

The focus of his project was centered on a potential therapeutic agent for retinoblastoma, 5-Aminoimidazole-4-carboxamide ribonucleotide (AICAR), which has been used in treatment of other medical issues, primarily cardiac ischemic injury, but never in retinoblastoma. AICAR functions as an analog of AMP that is capable of stimulating AMP Kinase (AMPK), thereby influencing cell proliferation.. They wished to test this in transgenic mouse models of retinoblastoma since these closely resemble human retinoblastoma. He found that it significantly reduced tumor burden in mice and reduced hypoxic regions, which could indicate it for use in conjunction with other treatments that target the rapidly-dividing tumor cells. He was able to present the data from his project at ESRF 2013, where he won the Alving award, and at the Association for Research in Vision and Ophthalmology 2012 meeting.

Thanks to his experiences in this field of research, Nikesh has decided to follow a career with an oncological component.

He is currently working on research in radiation oncology and looks forward to a career that has a mixture of oncology research and a strong clinical component so he can continue to see the patients his research is working to help. He is hopeful that his work will be continued with research into AICAR treatment alongside chemotherapy to test for reduced morbidity. His experiences in this field of research have confirmed to him that he would like to pursue a career with a component of research and has strengthened his desire to go into a field where he can focus on oncology.

Nikesh Shah Degree Program: M.D. Expected Graduation: 2016 Mentor: Timothy Murray, M.D., M.B.A., F.A.C.S. Honors: Presented at ESRF 2013 Activities: DOCS Hialeah Assistant Project Manager, ESRF Judging Chair Future Goals: Oncology

sg.mededu.miami.edu/medicalibis

S

ince middle school, Michael Schoor has been fascinated by methods in biomedical technology applied to helping the environment. As a student at UMMSM, Michael wanted to explore interdisciplinary research combining biomedicine with biochemical methods. Michael joined the Dr. Sapna Deo’s and Dr. Sylvia Daunert’s lab to work on a project aimed to capture energy from bioluminescent proteins using quantum dots (QDs), a crystals made of semiconductor material that displays quantum mechanical properties due to its microscopic size.

Quantum dots are commonly used as a technique to detect specific nucleic acids in cellular imaging, but Michael and his colleagues wanted to apply the principle to create a highly sensitive and specific means to detect DNA and RNA. Michael cultured E. coli bacteria with Renilla luciferase protein expression, and then harvested the protein to use for DNA detection.

Michael was able to show that the protein bioluminescence could cause QDs to emit a new spectrum if a DNA linker found its target sequence. Resonance energy transfer occurred by observing a new peak of visible light emission at 625 nm, a

“This is a very exciting step forward for the rapid and sensitive

detection of cancer

Michael with Dr. Sylvia Daunert, Dr. Sapna Deo and his lab group. to various complementary DNA sequences to see if multiple genes can be identified at once. Michael says that “this is a very exciting step forward for the rapid and sensitive detection of cancer cells, infectious bacteria, and gene expression in various parts of the human body.”

As for the research experience, Michael has enjoyed working with a close-knit group of colleagues in his lab. Michael speaks highly of the mentorship from Dr. Daunert, Dr. Manoj Kumar, Dr. Daohong Zang, David Broyles, and Eric Hunt. Michael is grateful for the opportunity to work with such amazing minds at the intersection of bioengineering and science. Michael would like to pay tribute to Leticia Kovalski, a graduate student in his lab who recently passed away from a car accident.

cells, infectious bacteria, and gene expression in various parts of the human Michael Schoor Degree Program: M.D. body.”

Expected Graduation: 2014 decrease in Rluc light emission at 485 nm. In other words, the changes in light emission from both the QD and the Rluc were used as a means to prove that DNA target sequence could be measured.

In the future, Michael and his colleagues plan to develop and to optimize the system as a rapid detection tool for all types of genetic material. Looking forward, they plan to attach QDs sg.mededu.miami.edu/medicalibis

Mentor: Sapna Deo, Ph.D. Honors: Presented at ESRF 2014 Activities: Jewish Student Medical Association, Student Government, Gross Anatomy TA, Nicaragua Medical Mission, Molecular Medicine Pathway Future Goals: Orthopedic surgery Spring 2014 | The Medical I.B.I.S.

19

CAMPUS

Arash demonstrating a goniometer on a model.

Photograph-Based Goniometry: A Comparison of Techniques

A

BY MELISSA STONE

s a first-year medical student, Arash Sayari spent his winter break shadowing an orthopedic surgeon near his home at UCLA. Arash became fascinated by orthopedics as a specialty and the ability of surgeons to recover a patient’s ability to walk, despite previously limping in pain, within a mere few hours. Desiring greater exposure to the field, he contacted Roy Cardoso, M.D., an orthopedist at University of Miami Hospital, for shadowing opportunities. When Arash went to Dr. Cardoso’s office, he happened to be chatting with a colleague, Robert Gray, M.D. Overhearing Arash and Dr. Cardoso’s conversation about

“My research is one

example of

how we can use new technology to step

forward in making medicine more efficient.”

Arash J. Sayari Degree Program: M.D. Expected Graduation: 2015 Mentor: Robert Gray, M.D. Honors: Presented at ESRF 2014 Activities: Director of Courvoisier Academic Society, DOCS, Project Volcano, Co-President Miami Students Without Borders Future Goals: Orthopedic surgery 20

The Medical I.B.I.S. | Spring 2014

sg.mededu.miami.edu/medicalibis

Arash’s interest in orthopedics and past experiences, Dr. Gray offered him a research opportunity on the spot.

Arash became highly engaged in Dr. Gray’s research study from the start. He soon began assessing the different measurement techniques for upper extremity joint movements, specifically flexion and extension of the elbow and wrist, and ulnar and radial deviation of the wrist. Orthopedists routinely measure angles of flexion and extension of joint movements to access the severity of the patient’s impediment and the patient’s subsequent deterioration or improvement. The current gold standard for these measurements is manual goniometry, using a modified protractor to measure the angle. Arash’s study compared manual goniometry, photograph-based goniometry, and visual approximations in measuring joint angles for seventy patients who visited the Orthopedic Hand Surgery Clinic at the Bascom Palmer Eye Institute. Arash performed many of the manual goniometry and photograph-based goniometry measurements while one orthopedic surgeon performed the visual approximations.

In comparing the techniques, Arash found that on average, manual goniometry took eight minutes to perform while visual sg.mededu.miami.edu/medicalibis

approximation and photograph-based goniometry took two and three minutes, respectively. The accuracies of the three techniques were determined to be clinically valid. Additionally, the inter-rater reliability for photograph-based goniometry was assessed and determined to be clinically valid. This was important to assess because many health care providers are often involved with treating an orthopedic injury. Arash believes, “In 2014, inter-rater reliability is more important to assess than ever before. With our changing health care system, orthopedists are more likely to rely on other medical personnel to perform these measurements.” Arash envisions that the future of orthopedics might entail another medical personnel taking joint measurements as part of routine division of labor before the orthopedist even sees the patient. Then, the orthopedist can spend more time examining and talking to the patient rather than recording measurements.

In 2014, we are also more likely to use techniques that easily allow us to record measurements in the electronic medical record (EMR) and work with existing technologies. Smartphones could act as the photograph-based goniometer, and the photographs can be easily stored in the EMR, easily accessed by various orthopedists for continued evaluation and assessment of improvement or deterioration.

Arash is currently a third-year medical student and plans on applying for residency in orthopedics next year. Under the direction of Dr. Gray, Arash is currently in the process of writing the manuscript for the research study and will soon submit it for publication. He is hoping that greater awareness within the orthopedic community for the efficiency, validity, and high interrater reliability for photography-based goniometry will inspire more orthopedists to routinely use this technique to improve efficiency and accuracy in the right clinical setting,. He hopes that in the coming years his study will be further validated by expanding the study population to other institutions with different orthopedists. He would also like to see this analyzed in other joints, as his study was focused on the upper extremities.

Arash is very thankful that Dr. Gray happened to be in Dr. Cardoso’s office on that fateful day and strongly believes that this experience in clinical research will enable him to be a better physician. Arash states, “Research pushes us to learn more, read more, and keep thinking about how we can improve medicine and better help our patients.” Arash’s research certainly is a step towards helping his future patients.

Spring 2014 | The Medical I.B.I.S.

21

CAMPUS Neuropathic Pain-Induced Depression and TNF

BY HOUDA BOUCEKKINE

M

Spencer analyzing a slide at his lab bench.

22

The Medical I.B.I.S. | Spring 2014

ood disorders such as anxiety and depression are common comorbidities of chronic neuropathic pain. However, the mechanism underlying this association has yet to be clarified. Current evidence indicates that levels of proinflammatory cytokines such as TNF are elevated in states of depression, and more specifically, the signaling of the soluble form of TNF (sTNF) through its receptor— TNFR1—can impair myelin production and neurogenesis in the hippocampus—one of the main mood-regulating centers of the brain (Dellarole et al.,2013, data not published yet). With this information in hand, Spencer Summers joined a team at The Miami Project to Cure Paralysis that has been seeking to elucidate the role of TNF and its receptors, the pro-inflammatory TNFR1 and the neuroprotective TNFR2, in neuropathic painassociated depression, which may provide evidence for more targeted treatment options.

Spencer has always had an interest in immunology and neurology, having had performed neuroscience research as an undergraduate at Vanderbilt University. Thus, when the opportunity to join the Immunologic Medicine Pathway of Emphasis presented itself, he searched for a project that would combine both fields.

Under the mentorship of Anna Dellarole Ph.D. and Prof. John Bethea Ph.D., Spencer worked as part of a team, conducting basic science research with TNFR1 knockout mice to determine the immunological mechanism underlying neuropathic pain and associated depression. Pain was induced by constriction of the sciatic nerve and was measured at subsequent weeks via thermal and mechanical sensitivity tests. Depression was assessed by the amount of sugar water that the mice drank, with less suggesting a depressive, or anhedonic, state. The mice were sacrificed at different periods to determine the levels of TNF, TNFR1, and TNFR2 expression as well as the amount of myelination in the hippocampus.

The results showed that the control wild type mice presented with increased signs of pain and depression with elevated levels of hippocampal TNF. Interestingly, they were also found to have less neurogenesis and synaptic proteins within the hippocampus.

Alternatively, the knockout mice lacking expression of TNFR1 did not present with neuropathic pain or depression. Furthermore, they did not exhibit any alterations in the hippocampus.

This difference suggests that TNF/TNFR1 play an important role in the development of depression. As for TNFR2, expressg.mededu.miami.edu/medicalibis

“Performing research at the

Miami Project is inspiring; it’s a daily reminder of how much medicine has yet

to

discover.” sion was reduced in the wild type mice, but remained unchanged in the TNFR1 knockout mice, thereby indicating that TNFR2 may be a factor in preventing neuropathic pain and depression.

This is the first study confirming a role of TNFR1 in the mediation of neuropathic pain-induced depression. Spencer emphasized the promising potential of these results for targeting TNFR1 as a specific method for treating pain and the associated mood disorders. A more specific treatment than those currently available may provide alleviation of pain symptoms, as well as relief of the socially and psychologically crippling effects of depression that over half of those with neuropathic

pain suffer from.

Dr. Bethea’s lab is currently working to identify the cells primarily responsible for secreting TNF in the CNS and to delve deeper into the role of TNFR2 as a neuroprotective factor.

Spencer continues to be involved in these experiments, constantly amazed by how seemingly simple concepts presented in lecture are transformed into intricate realities in the lab. He finds it very rewarding to be part of new discoveries that may have greater implications down the road. As such, Spencer hopes to continue his involvement in research throughout his career, potentially as a physician-scientist.

Spencer Summers Degree Program: M.D. Expected Graduation: 2016 Mentor: John Bethea, Ph.D.; Anna Dellarole, Ph.D. Honors: Poster presentation at the Florida Medical Association Annual Meeting 2013 Activities: Ethics Representative, DOCS South Dade Health Fair Project Manager, Gross Anatomy TA, Dermatology Interest Group, Immunologic Medicine/Infectious Diseases Pathway of Emphasis Future Goals: Neurosurgery, orthopedic surgery, or allergy/immunology

sg.mededu.miami.edu/medicalibis

Spring 2014 | The Medical I.B.I.S.

23

CAMPUS LBH Role in Normal and Neoplastic Mammary Stem Cell Control

Curcumin Treatment Promotes Glioblastoma Stem Cell Death

BY JEFFREY SMITH

BY LAURA BLOOM

U

nlike most of her peers, Linsey Lindley, a firstyear student at the Miller School, was already a doctor upon entering medical school. She successfully defended her thesis and graduated with her Ph.D. from the Department of Biochemistry and Molecular Biology at UMMSM under the supervision of Dr. Karoline Briegel, Ph.D. Linsey’s research focused on the WNT signaling pathway and its role in breast cancer, which she became interested in due to the multi-disciplinary nature of the project. She recalls, “This project was very exciting in that all of these fields of study were melded to form a project that aimed to tease apart the inner workings of a completely novel potential therapeutic target for a particularly lethal type of breast cancer: basal-subtype triple negative breast cancer (TNBC).”

Breast cancer is the second leading cause of cancer-related deaths in women, with aggressive basal-subtype breast cancers disproportionally contributing to the number of deaths, primarily due to the lack of targeted molecular therapies available. This breast cancer subtype displays hyperactivation of the WNT pathway and is characterized by an undifferentiated tumor phenotype enriched in cancer stem cells. Limb-Bud and Heart (LBH) is a novel transcriptional regulatory protein in the WNT pathway with unknown physiological function, which was originally discovered by Dr. Briegel’s laboratory. Interestingly, LBH is expressed in breast stem cells, which are located in the basal epithelial cell layer of the mammary gland, but is also overexpressed in basal-subtype breast cancers and may represent a molecular target for TNBC treatment. To determine the

Linsey Lindley, Ph.D. Degree Program: M.D. Expected Graduation: 2017 Mentor: Karoline Briegel, Ph.D. Honors: Published in Genesis (PMID 23495064), PLoS ONE (PMID 22844464), Biochemical & Biophysical Research Communications (PMID 23495064), poster or oral presentations at 10 different conferences Activities: DOCS Future Goals: Academic medicine 24

The Medical I.B.I.S. | Spring 2014

Z

achary Gersey came to the Miller School in 2012 knowing he wanted to work on cancer. Having spent two years on kidney and prostate research at the University of Florida, Zach was quick to shadow in the oncology department. With a dual interest in neurosurgery, it wasn’t long before a neuro-oncologist in the wards introduced Zach to Dr. Ricardo Komotar, M.D. and Dr. Regina Graham, Ph.D. Dr. Komotar conducts numerous research projects at the UMBTI – the Brain Tumor Initiative, which he hopes someday will become the Brain Tumor Institute.

This past July, Zach began conducting research with Dr. Komotar and Dr. Graham on Glioblastoma Multiforme (GBM) – the most

mechanistic function of LBH in normal stem cell biology and cancer, Linsey’s laboratory developed a unique LBH knockout mouse model. It was demonstrated that upon inactivation of LBH function, the mice exhibited a delay in pubertal mammary gland development and a skewed distribution of epithelial cell development. This could be traced to a deficiency in the selfrenewal ability and number of mammary stem cells. They also modulated the expression of LBH in human breast cancer cell lines to determine the role of LBH in cancer stem cell development.

The data from these experiments showed that LBH is required for cancer stem cell formation by promoting a basal stem cell state and repressing expression of luminal lineage-specific genes, specifically ER. They also identified a LBH molecular target protein, the key epithelial stem cell transcription factor ΔNp63, which in great part may explain the stem-cell promoting effects of LBH. They concluded that LBH plays an essential role in promoting mammary stem cell function in both normal and cancerous settings. Importantly, their findings suggest inhibition of LBH could be used to re-sensitize tumor cells to known endocrine therapies targeted against ER. Linsey believes future studies will focus on clarifying the nature of interaction between LBH and ΔNp63 and how this represses expression of ER. Linsey enjoyed the challenges that came with studying a novel protein at a very basic level and using these findings to explore the pathological context of breast cancer. She believes this research will help her achieve her future goals, which include working in an academic medicine setting that would allow her to interact directly with patients and continue to pursue research focused on novel molecular treatments. sg.mededu.miami.edu/medicalibis

Zachary pippetting at the tissue culture bench. sg.mededu.miami.edu/medicalibis

Zachary Gersey Degree Program: M.D. Expected Graduation: 2016 Mentor: Regina Graham, Ph.D. Honors: Presented at Miami Winter Symposium: The Molecular Basis of Brain Disorders 2014 Activities: Vice President of Hematology/Oncology Student Interest Group, Academic societies training aid Future Goals: Neurosurgery, oncology common and most lethal form of brain tumor in adults. Current treatment for GBM is a combination of surgical resection of the tumor, radiation, and temozolomide (oral chemotherapy drug). Zach describes this as ‘invasive palliative care,’ because patients are still only expected to survive 12-14 months due to tumor recurrence.

The stem cell theory of cancer proposes that among cancerous cells, a few act as stem cells that produce and sustain the cancer, thereby leading to recurrence despite resection of many of the mature cancer cells. Previous research suggests a connection between GBM and the ‘notch pathway,’ as well as the anti-cancer properties of curcumin (principle ingredient in turmeric), which inspired this research project.

GBM tumor cells were collected from six consenting patients, and then cultured to enrich for tumor stem cells. These cells were then treated with the standard temozolomide as well as curcumin. Incredibly enough, the GBM tumor stem cells began to die, indicating great success.

As often happens in research, this discovery led to more questions.

In fact, only curcumin – not temozolomide – affected the GBM stem cells. Also, curcumin was not influencing the ‘notch pathway’ after all, but rather levels of the protein ‘survivin.’ Survivin inhibits cell death, is overexpressed in many malignancies, and correlates with poor prognosis in GBM. Zach’s data suggests that curcumin induces GBM stem cell death at least in part by down regulation of survivin.

Curcumin may target additional neoplastic pathways and thus has positive therapeutic implications for GBM as well as other cancers.

Zach is excited for the future of this research. He presented this project in January at the Miami 2014 Winter Symposium: The Molecular Basis of Brain Disorders. There is still much work to do, but Zach hopes that this will eventually enter clinical trials. After all, the ultimate goal is to find a cure that can someday help real people.

Spring 2014 | The Medical I.B.I.S.

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CAMPUS Insurance Implications for Choice of Stent Type

H

BY HOUDA BOUCEKKINE

ealth care insurance is a topic that everyone is speaking of nowadays, with all the recent changes that have occurred. A driving subject behind these changes has been the issue of healthcare disparities within our society, in terms of access to and quality of healthcare received. With an interest in this topic, Jamie Diamond came up with a research project with her mentor, Leonardo Tamariz, M.D., which would exemplify the extent to which healthcare disparities and stereotypes are present within the medical setting.

Jamie decided to look into the use of drug-eluting stents (DES) versus bare-metal stents (BMS) to reduce restenosis in

angioplasty or percutaneous coronary intervention patients. It is well established in the literature that DES have clear clinical advantages and are more effective than BMS in decreasing the prevalence of restenosis in cardiac patients. The issue is that DES are a more expensive option. Furthermore, they require more self-care in regards to the patient; with DES, dual antiplatelet therapy (DAPT), such as Plavix and aspirin, must be implemented by the patient for a longer period of time than with BMS. These facts and physician opinion about compliance often drive physicians’ decision to utilize a DES or BMS for a patient.

Jamie decided to delve further into this topic by determining if the insurance (or lack thereof) carried by the patient may have

Jamie analyzing articles for meta-analysis.

played a factor in the physician’s decision to use a DES or BMS. The research involved a meta-analysis of published articles that noted when a patient was given a DES or BMS and what insurance the patient had. In order to do this analysis, Jamie performed a systematic search of Pubmed with keywords such as “insurance”, “stent”, “United States”, and “Percutaneous Coronary Intervention.” The search resulted in 872 publications, and Jamie sifted through all these articles to pick out those in which the research was performed in the United States, and which compared DES vs BMS use among government insurance subtypes Medicare and Medicaid, HMO insurance, and uninsured populations, with commercial insurance as the reference.

She was able to reduce the analysis to 13 publications, on which she used two statistical random-effects models to calculate the relative risk of stent use based on insurance.

The results of the meta-analysis revealed that bare-metal stents were more likely to be utilized in patients with government insurance or no insurance than in patients carrying commercial insurance. Similarly, Medicare and Medicaid patients were also more likely to receive BMS rather than DES when compared to their commercially-insured counterparts. This analysis in itself shows that care differs between patients who have different kinds of insurance; specifically, it leans towards the idea that those with less coverage receive less quality care.

It is thought that all patients who can comply with the DAPT regimen should receive the DES considering the greater effectiveness of these stents, but statistics indicate otherwise. Given the fact that physicians are the ones who decide whether the patient receives a BMS or DES, the results suggest that physicians may be including a person’s coverage or expected DAPT compliance in their decision, versus making a purely medical decision. Jamie mentions hearing a physician admit that choice of stent placement is typically made by the physician based on physical appearance and expected medication compliance rather than shared decision-making with the patient. Of course, this logic and profiling is conjecture, but regardless, the results of the meta-analysis show that those with less coverage are less likely to receive the highest quality care in terms of stents.

“This is a good message

to remind people not

to judge their patients, and that they deserve

high quality care no

matter what type of insurance.”

As Jamie puts it, the main message received from this research project is that people with different types of insurance receive different care. It is another example of health disparities that exist in our society. Jamie hopes that the results of this research make people aware of a form of healthcare disparity that many may not know of, and she hopes it encourages medical personnel to not judge their patients. This vision is in line with her passion for public health and her future goal of being involved with healthcare policy and legislation. As such, this research project allowed her to not only experience a new type of research (i.e. a meta-analysis involving statistical methods), but it also enabled her to delve into the realm of public health, thus experiencing a real-life application of the lectures she receives as part of the MD/MPH program. She envisions a future career that combines her interest in cardiology and her desire to help with the issue of discordant healthcare provision.

Jamie Diamond Degree Program: M.D./M.P.H. Expected Graduation: 2016 Mentor: Leonardo Tamariz, M.D., M.P.H. Honors: Global Health Scholars Award from the University of Miami Department of Public Health Sciences; Presented at the American College of Cardiology 63rd Annual Scientific Session 2012, 2013, and 2014 Activities: American Medical Student Association “Whats Up Doc” Coordinator, DOCS Liberty City Health Fair Public Relations Coordinator, M.D./M.P.H. Representative of the UMMSM Public Health Student Association Future Goals: Cardiology, public health, healthcare policy 26

The Medical I.B.I.S. | Spring 2014

sg.mededu.miami.edu/medicalibis

sg.mededu.miami.edu/medicalibis

Spring 2014 | The Medical I.B.I.S.

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StemCAMPUS Cell Particles Promote Development of New Blood Vessels in the Healing of Chronic Wounds

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BY LAURA BLOOM

udrey Cox is devoting the year between her third and fourth years of medical school at Miller School to full-time dermatologic research at UMMSM. In July, she started working on an exciting project exploring the relationship between stem cell particles and chronic wound healing.

Audrey completed her undergraduate education at the University of Florida, where she majored in Zoology and minored in Art History. She was involved in esophageal cancer and melanoma research. Audrey has maintained her love for art by painting for the ACC clinics here at Jackson. She is a member of the Ethics & Humanities pathway and was inducted into the Alpha Omega Alpha Honor Medical Society during her junior year.

Audrey is pursuing a residency in Dermatology and intends to continue her involvement in research throughout her professional career. While Audrey’s current research has a dermatologic focus, the problems surrounding chronic wound healing extend throughout the field of medicine – notably in the complications associated with diabetes. Audrey was drawn to this particular research project because of the cutting-edge stem cell component. The project’s principle investigator, Dr. Evangelos Badiavas, has an M.D./Ph.D. in Dermatology, completed his fellowship in dermatolopathology, and has a clinic and research lab at UM. Stem cell therapy was previously thought to enhance wound healing by replacing injured tissue. Yet it turns out that very few

Audrey Cox Degree Program: M.D. Expected Graduation: 2015 Mentor: Evangelos Badiavas, M.D., Ph.D. Honors: Alpha Omega Alpha Honor Medical Society Activities: Ethics & Humanities Pathway, painting for ACC

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our hope that “It is

stem cells are actually found in the site of injury; instead, they induce healing through communication with other cells in the wound bed. One of Audrey’s research partners, Dr. Arsalan Shabbir, an M.D./Ph.D. and first year Dermatology resident, began exploring stem cell particles called ‘exosomes.’ Audrey’s current research continues this exploration. Exosomes are vesicles that contain RNA, DNA, and protein. It is speculated that exosomes carry signals from bone marrow derived mesenchymal stem cells (BM-MSC) that result in wound healing.

To test this hypothesis, BM-MSC exosomes were isolated with a centrifuge, identified by electron microscopy, and labeled with dye. These exosomes were found to be taken up by human umbilical vein endothelial cells (HUVEC), where they significantly increased capillary tube formation, indicating that these particles enhance angiogenesis (formation of new blood vessels

from existing ones).

The major finding of this project is that BM-MSC derived exosomes may act as “communication vehicles” through which BM-MSC induce wound healing. There is an increase in both angiogenesis and migration, which can improve in vitro wound healing. It appears that exosomes are able to induce wound healing without the stem cells being present.

The ideal clinical application of this research would be to grow BM-MSC’s sterilely in a lab and then inject the exosomes into the wound bed. The use of exosomes, rather than whole stem cells, would hopefully avoid immune reactions and infections, be less invasive, easier, and provide better results. Audrey will present on this project at UM in March at ERSF. Audrey hopes to see this become a treatment for patients suffering from chronic wounds.

Audrey at the tissue culture bench.

exosomes will

one day make

stem

cell therapy accessible t o

t h e

general

Future Goals: Dermatology

population.”

The Medical I.B.I.S. | Spring 2014

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Effect CAMPUS of Colon Transection on Spontaneous High-Amplitude Propagating Contractions

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BY GABE WEINGROD-NEMZOW

iddish is the language of choice when constructing insults for your nemesis. Rather than being vulgar, they are elegant and witty phrases meant to invoke utter contempt. Its repertoire of curses includes “may you grow like an onion with your head in the ground” or “may I live long enough to attend your funeral.” But the worst possible curse, the one that should only be said to your worst enemy, is “may you have Hirshsprung’s Disease.”

“Having a family member with Hirschsprung’s inspired me to understand why some may still have problems even after “curative” therapy.”

Hirschsprung’s Disease (HD) is characterized by aganglianosis of the rectum, which in normal terms is an absence of the motor neurons (ganglion cells) controlling the rectum and lower large intestine. This results in severe constipation. If not recognized and treated, the large intestine will pop like a balloon, leading to a severe bacterial infection with a high death rate. Hirschsprung’s is usually diagnosed within the first week of life when a baby is found not to soil its diaper, and is treated by cutting out the diseased intestine. This procedure is called a colonic transection.

Although they are “cured” of Hirschsprung’s with the surgery, many suffer from a minor loss of neurons throughout the rest of their intestines, resulting in chronic constipation. This lasting neuronal dysfunction is a highly researched topic.

Sharon Wolfson, a second year medical student at Miller School, is fighting to cure their constipation. This fight is personal. When she was 15, a close family relative was diagnosed with Hirschsprung’s. She became involved in the treatment, and while searching on the internet to learn more about HD, she found an article by Dr. Paul Hyman, a Professor of Pediatrics 30

The Medical I.B.I.S. | Spring 2014

at LSU and Chief of Pediatric GI and Nutrition at Childrens Hospital of New Orleans. Sharon called him to discuss possible treatments for her relative. Dr. Hyman was impressed with the knowledge of this 15 year old, invited her to conduct research with him the following summer of 2007, and she presented her own research at Digestive Disease Week, which she describes as the “biggest and baddest international Gastro-Intestinal conference in the entire world.”

Sharon took some time off from studying Hirschsprung’s while studing Biomedical Engineering at Boston University, and instead did research in both a respiratory mechanics lab (to cure asthma) and an auditory neurophysiology lab. Her impressive resume and personality landed her a prestigious $4000 grant from the North American Society for Pediatric GI, Hepatology, and Nutrition (NASPGIHN) to do more research with Dr. Hyman during her first medical school summer break in 2013.

Working with an LSU student, Courtney Jacobs, Sharon did a retrospective study on the constipation that 500 children, with an average age of 7.5 years, suffered from. Using a fancy colonoscopy probe that detects the strength of muscle contractions, they measured the number of High Amplitude Progagating contractions, or HAPCs, that four groups of children had in their large intestines both before and after eating a meal. These groups consisted of a set of children with HD, a colostomy control group consisting of children who had a colon resection for any reason except Hirschsprung’s, children with functional constipation (everything works but they are unable to relax

their pelvic muscles out of fear of defecating) and children with chronic abdominal pain.

In normal individuals, there are periodic HAPCs that serve to help propel food through the colon. Eating tends to accentuate this process, as if to make room for the new food. Previous research has found that colonic transection causes an increase in the frequency of HAPCs both before and after eating. In the experiment, children’s HAPCs were measured before and after eating. She found that patients with HD and the colostomy control patients had more HAPCs on average than children with functional constipation or chronic abdominal pain. This would mean that the higher frequencies of HAPCs observed in HD patients were due to the colonic transection and not due to the neuronal dysfunction in HD. Upon further analysis, Sharon and her colleagues also found that the HD patients had a bimodal distribution of HAPCs. This means that there were two subsets of Hirschsprung’s Disease patients, some with high frequencies of HAPCs and some with low frequencies of HAPCs. These two Hirschsprung’s Disease groups averaged out to a similar value to the colostom control patients, which originally led her to believe that this was the effect of the colonic resection. “It was tricky to figure it out that they

were different”, she said. “We just started crunching numbers.”

Interestingly, the Hirschsprung’s Disease patients with frequent HAPCs also reported having fecal incontinece. Those HD children with fewer HAPCs, however, reported constipation. These constipated children seemed just like children with a general functional constipation, simply unable to relax their pelvic floor muscles because of fear of pooping. This indicates there is a subset of Hirschsprung’s Disease patients that have abnormal neuronal control. Ms. Wolfson belives that if these nuerons could be controlled, many children with Hirschsprung’s Disease could have some relief for their symptoms.

Sharon is hopeful that her research will provide relief to HD patients. By defining subgroups of patients, treatments can be devised to limit or control the side-effects. “If we did a different type of surgery”, Sharon wondered, “ would that prevent the incontinence? Could the incontinece be genetically linked?”

Future studies could hopefully bring mankind a step closer to alleviating the symptoms of Hirschsprung’s Disease.` One day soon, “may you have Hirschsprung’s” will be a laughable curse.

Sharon Wolfson Degree Program: M.D. Expected Graduation: 2016 Mentor: Paul Hyman M.D. Honors NASPGHAN Summer Research Fellowship, 2012 Earle and Mildred Bailey Memorial Award Activities: Genetics and Genomics Pathway of Emphasis, DOCS Jack and Jill Health Fair Project Manager Future Goals: Neurosurgery/Gastroenterolgy Sharon in front of the Lois Pope fountain. sg.mededu.miami.edu/medicalibis

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