E. Danielle Dean, Ph.D.
Principal Investigator
Associate Professor of Internal Medicine, Division of Endocrinology, Diabetes, and Metabolism
danielle.dean@osumc.edu
Dr. Dean's interests are how nutritional status and environmental-gene interactions contribute to aging and diseases like diabetes. She received her B.S. and M.S. from the University of Tennessee in Biochemistry, Cellular and Molecular Biology in the lab of Dr. Ranjan Ganguly. She then received her Ph.D. from Emory University in Molecular and Systems Pharmacology where she was a toxicology scholar in the lab of Dr. Gary W. Miller. Dr. Dean joined the laboratory of Dr. Al Powers for her postdoctoral fellowship at Vanderbilt University Medical Center. After launching her independent laboratory at Vanderbilt, she is now Associate Professor of Internal Medicine at the Ohio State University.
While much effort has been focused on understanding beta cell biology because of insulin's well-known role in diabetes, very little is known about signals regulating other islet cells. Alpha cells secrete glucagon in response to hypoglycemia, but persons with diabetes have hyperglucagonemia contributing to hyperglycemia. In an effort to understand the molecular mechanisms that determine alpha cell mass in the pancreatic islet, she identified a liver-alpha cell axis, a crosstalk between liver glucagon signaling and alpha cells sensing of amino acids. Much of the lab's focus is to understand how a liver-alpha cell axis regulates islet cell growth and how this axis might contribute to liver and alpha cell dysfunction in obesity and diabetes.
Anna Schornack, B.S.
Molecular Physiology and Biophysics Graduate Student
Anna received her B.S. in Electrical and Electronics Engineering from North Dakota State University and enrolled in the Interdisciplinary Graduate Program at Vanderbilt University in 2023. Anna has a longstanding passion for beta cell regeneration work sparked by her postbaccalaureate research in Dr. Quinn Peterson's lab at Mayo Clinic where she used differentiation programs to generate human stem cell derived alpha-like and beta-like cells. In the Dean lab, she is examining how alpha cells use glutamine as a fuel differently than other islet cells. Anna was awarded a F31 fellowship award from NIDDK in June 2026.
Katelyn Sellick, M.S.
Research Associate III
Katelyn received her B.S. and M.S. in Microbiology from East Tennessee State University in 2019. Currently, Katelyn's work in the lab is focused on the role of glutamine transport in islet cell proliferation and hormone secretion with a focus on the transporter SLC38A5. She is also interested in the role of dysregulated glucagon signaling in the pathology of obese liver and diabetes.
Juliet Anawalt, B.A.
Graduate student
Juliet received her B.A. in Biology and French and Francophone Studies from the University of San Diego. From sophomore to senior year, Juliet conducted organic chemistry research in the Schellinger lab, where she synthesized polymers capable of mimicking the antimicrobial activity of naturally occurring antimicrobial peptides. During this time, she also played for their Division I Women’s Soccer team. Currently, Juliet is pursuing her Master’s in Biomedical Sciences at Vanderbilt. She joined Dr. Dean’s lab to explore the role of dietary protein in regulating metabolic dysfunction in mice. Upon graduating, Juliet aspires to earn her M.D. in orthopedics, endocrinology, or cardiology.
Former Lab Members
Jade E. Stanley-Jefferson, Ph.D.
Molecular Physiology and Biophysics Graduate Student
Jade received her B.S. in Chemistry from Tuskegee University and enrolled in the Quantitative and Chemical Biology Graduate Program at Vanderbilt University in 2019. Jade is the recipient of a NIDDK F31 for her work in the lab. Jade's research focused on the role of arginine transport and sensing in islet cell proliferation and hormone secretion especially to understand the underlying mechanisms of why loss of the arginine transporter SLC7A2 results in complete loss of glucagon secretion. Jade defended in June 2025 and will be a tenure-track Assistant Professor In Biological and Environmental Sciences at Samford University in Birmingham, AL starting August 2025.
Madushika Wimalarathne, Ph.D.
Postdoctoral Fellow
Madushika received her B.S. from the University of Peradeniya, Sri Lanka. She received her Ph.D. in biotechnology science and engineering from the University of Alabama in Huntsville. She worked on nonalcoholic steatohepatitis development in insulin-resistant LEW.1WR1 rats in the Rutledge lab.
Dr. Madushika joined Dr. Dean's laboratory for her postdoctoral fellowship at Vanderbilt University Medical Center. Her interests include the alpha cell enriched-tetraspanin domain protein TM4SF4. She believes TM4SF4 plays a crucial role in arginine sensing in alpha cells. She is characterizing the function of TM4SF4, defining its binding partners, and using knockout mouse models to elucidate the role of TM4SF4 in alpha cell proliferation and glucagon secretion.
Angelina Ehara, B.A.
Undergraduate Student (Vanderbilt)
Angelina graduated from Vanderbilt University with a BA in Neuroscience and Medicine, Health, and Society major on a pre-med track in May 2026. She is an aspiring neurosurgeon and interested in a career as a physician scientist in clinical neuroscience. While in the Dean Lab, her primary research interests were dementia, aging, and metabolism. Angelina's long-term goal involves identifying alternative pathological pathways for Alzheimer's Disease as a metabolic disorder closely associated with type 2 diabetes, and her current project focuses on understanding the effects of hyperaminoacidemia on the aging brain. Angelina was a VUSRP program fellow at Vanderbilt.
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Fedora Ogodo
Undergraduate Student (Vanderbilt)
Fedora is originally from Nigeria but now resides in Lancaster, MA. She is a senior at Vanderbilt University, majoring in Biochemistry with a minor in Data Science, and was recently accepted into the V-SMART program to support her research in the Dean lab during Summer 2025.
Fedora’s work in the Dean lab is focused on the role of the glutamine transporter SLC38A5 in pancreatic islet alpha cell proliferation. Her primary research interests are in cardiometabolism, diabetes, and nutrition. After completing her bachelor’s, Fedora hopes to enroll in medical school to pursue a career in Pediatrics. Currently, she is working on her senior thesis in the Drigo lab at Vanderbilt.
Sarah Qaddo, B.A.
Undergraduate Student (Vanderbilt)
Sarah grew up in Knoxville, TN and graduated from the Dean Lab at Vanderbilt University majoring in Neuroscience and Medicine, Health, and Society with a minor in Spanish in May 2026. Sarah is interested in a career as a physician scientist. Her interests in diabetes research are rooted by her family members and those around her affected by the disease. As a Pre-Med student, Sarah understands the importance of research in medicine and hopes to contribute to the field through her work in the Dean lab where she focused on glutamine and glutathione transport and metabolism in alpha cells. Sarah wrote an honors thesis for her work in the lab.
Tyler Rodgers, B.A.
Undergraduate Student (Vanderbilt)
Tyler is from Sewanee, TN and graduated from St. Andrew’s - Sewanee School. While in high school, Tyler joined the Tennessee National Guard and trained as a combat medic at Fort Sam Houston in San Antonio. in addition to his service, he is currently a rising Sophomore at Vanderbilt University majoring in Biochemistry/Pre-Med. In the future, Tyler plans to attend medical school and pursue a career in surgery as a physician scientist or as a flight surgeon in the United States Armed Forces. While working in Dean Lab, Tyler studies how alpha to beta cell transdifferentiation in pancreatic islets is enhanced by glucagon receptor antagonism, work aimed at regenerating functional beta cell mass for individuals with type 1 diabetes especially by targeting glutamine metabolism. Tyler received research funding support from the VUSRP program at Vanderbilt. Tyler wrote and defended his Honors thesis in April 2026 with Highest Honors.
Soham Saraf, B.A.
Undergraduate Student (Vanderbilt)
Soham is a sophomore at Vanderbilt University majoring in Medicine, Health, and Society and English with a minor in data science and was awarded a 3-year SyBBURE fellowship to support his research in the Dean Lab. Soham has previously worked in a cell biology and cancer lab at WashU School of Medicine. In the Dean lab, Soham is interested in arginine transport into subcellular compartments and how this might affect glucagon secretion and alpha cell proliferation. He also applies his data science training to tease out pathways affected by amino acid signaling using large RNA-Seq datasets. Currently, Soham is pursuing postbac research prior to enrolling in medical school at WashU School of Medicine. He aspires to be a physcian scientist specializing in either endocrinology, oncology, or infectious diseases.
Nitin Shankar, B.A.
Undergraduate Student (Vanderbilt)
Nitin grew up in Columbus, Ohio and graduated from Vanderbilt University in Medicine, Heath & Society and Economics. While in high school, Nitin co-founded a research project with a researcher at the Ohio State University related to epidemiology to understand the genetic link between lactose intolerance and colorectal cancer. In the Dean Lab, he helped to characterize TM4SF4, a protein highly expressed in pancreatic alpha cells that could act as a possible arginine sensor. He aspires to pursue a career in medicine, specifically hoping to specialize in cardiology. Currently, he is working with Otolaryngology Associates of Tennessee as a medical assistant.
Walter Siv, B.A.
Gap Year and Undergraduate Student
Walter received his B.A. in Neuroscience from Vanderbilt University in 2020 where he was a SyBBURE fellow in the Dean Lab. He continued his research in the lab after graduation as a gap year student. Walt's work in the lab focused on the role of glutamine metabolism in islet cell proliferation and hormone secretion with a focus on the enzyme glutaminase. Immediately after leaving the Dean lab, Walt began medical student at University of Tennessee in Memphis. Currently, Walt is a resident physician in Pediatrics at Emory University.
Matthew Shou, B.A.
Gap Year and Undergraduate Student
Matthew received his B.A. in Molecular Biology from Vanderbilt University in 2021 where he received a Commendation for Research in Biological Sciences from the Department of Biological Sciences for his Honors thesis based on his work in the Dean Lab. Matthew was also a VUSRP fellow. He elected to continue his research in lab as a gap year student. Matthew's work focused on the role of arginine and glutamine metabolism in islet cell proliferation and hormone secretion with a focus on the enzymes arginase and glutaminase. After leaving the Dean lab, Matthew attend medical school at Vanderbilt. Currently, Matthew is a PGY1 in Urology at Vanderbilt.
Taverlyn Shepard, B.S.
VERTICES GAP year student
Taverlyn received her B.S. in Biology from Prairie View A&M University. Taverlyn served as Miss Prairie View A&M University 2022-2023. In 2023, she was an AMGEN Scholar at Yale University investigating the role of macrophage-derived inflammation in aged female mice. Currently, she is a fellow in the Vanderbilt Experimental Research Training Inclusion Community Engagement Skills (VERTICES) Postbaccalaureate Research Education Program. In the Dean Lab, she is investigating how protein in diet influences metabolic dysfunction in mice, especially glucagon secretion and amino acid transporter expression that promotes alpha cell proliferation. Currently, Taverlyn is in graduate school in the Molecular Physiology PhD program at Vanderbilt.
Varsha Chigurupati, B.S.
Summer Undergraduate/Medical Student (Nova/William Carey)
Varsha grew up in Franklin, TN where she attended Fred J. Page High School. She graduated from Nova Southeastern University in Fort Lauderdale, FL in 2024. Currently, she is pursuing a career in osteopathic medicine at William Carey College of Medicine in Hattiesburg, Mississippi as an OMS-II student where she plans to specialize in Emergency Medicine. Her interests in diabetes research are rooted by her family members because many are suffering with diabetes. Her work in the lab included understanding glutamine transport and metabolism in pancreatic islet alpha cells and its role in amino acid induced alpha cell proliferation. She continues to stay involved in research during medical school including spending summers in the Dean lab.
Heli Butala, M.S.
Medical Student (Lake Erie COM)
Heli received her B.A. in Chemistry with a minor in Biology from University of Louisville and M.S. in Medical Science from Lake Erie College of Osteopathic Medicine. Heli joined the summer 2024 in the Dean lab as part of the NIDDK T35 Summer Research Training Program for rising 2nd year medical students which she continued her data analyses remotely from PA for the following year. Heli's research focuses on translating potential treatments for Mahvash disease, a rare congenital pancreatic alpha cell tumor syndrome, using mouse models of the disease. Her research suggests that early intervention with a low protein diet reduces hyperaminoacidemia and alpha cells hyperplasia by reducing the mTOR activation and amino acid transporter expression that promote alpha cell proliferation. She is currently an OMS-IV medical student at Lake Erie College of Osteopathic Medicine.
Austin Reuter, M.S. Pharm.D.
Pharmacy Doctoral Candidate and Research Associate
Austin received his B.S. and M.S. from the University of Wisconsin where he worked in the lab of Dr. Michelle Kimple on prostaglandin regulation of beta cell function. He graduated from Belmont University PharmD program. While in pharmacy school, Austin worked in the lab to understand the role of a novel putative arginine binding protein and arginine transport in alpha cell and the pathology of obese liver and diabetes. He is now a fellow with Rx Partners, LLC.
Cecil Rodgers
Undergraduate Student (Sewanee)
Cecil is from Sewanee, TN and graduated from St. Andrew’s - Sewanee School. He is currently a rising Sophomore at University of the South/ Sewanee majoring in Pre-Med where he plays Wide Receiver for the football team. In the future, Cecil plans to attend medical school. While working in Dean Lab, Cecil studied how interrupting glucagon signaling in the liver affects immune cell infiltration in the biliary tree and pancreas. Cecil has received research funding support from Sewanee.
Mounika Aramandla, M.S.
Summer Medical Student (University of Pikeville Kentucky)
Mounika received her B.S. in Biology with a minor in Spanish from Rhodes College and a M.S. in Biomedical Sciences from Kansas City University. As a high school senior and an undergraduate, Mounika previously worked in Dr. Maureen Gannon’s lab at Vanderbilt focusing on the role of connective tissue growth factor’s role in pancreatic beta cell mass and hyperplasia. She also did molecular immunotherapeutics research while at Rhodes College in Dr. Shana Stoddard’s Lab, focusing on developing novel therapeutic proteins for the autoimmune disorder primary membranous nephropathy and characterizing one of the proteins targeted in this disorder. After her first year of medical school in Summer 2023, Mounika worked in the Dean lab studying the role of an amino acid transporter, SLC38A5, in alpha cells under amino acid stress as part of the NIDDK T35 Summer Research Training Program for medical students. She is currently a OMS-IV medical student at an osteopathic medical school, University of Pikeville Kentucky College of Osteopathic Medicine.
Alexandria Bustabad, B.S.
Summer VSSA Student (USF)
Alex recently graduated from the University of South Florida with a B.S. in Cellular and Molecular Biology and a minor in Public Health. Alex is a post-bac student participating in the Vanderbilt Summer Science Academy. Alex is interested in using a glucagon receptor antagonist to facilitate transdifferentiation of alpha to beta cells in diabetic mice models to see if it is possible to see a augment glucose responsive insulin secretion. Alex is currently a 2nd year graduate student at Wake Forest University.
Selina Park
Summer Medical SRTP Student (Creighton)
Selina received her B.S. in Molecular, Cell and Developmental Biology from the University of California, Los Angeles. She is currently a second-year medical student (MS2) at Creighton University School of Medicine - Phoenix. She joined the Dean Lab in the summer through the NIDDK T35 Medical Summer Research Training Program. Her research focuses on protection from cell death in alpha cells. Long-term, she hopes to apply this experience toward advancing the understanding and treatment of diabetes to improve patient care.
Aaniyah Jarrette
Undergraduate AHA SURE Summer Student (Spelman College)
Aaniyah is from Atlanta, GA, and is a senior Biology major at Spelman College. During the academic year, she serves as a Research Initiative for Scientific Enhancement (RISE) Scholar, HCOPPP Scholar, Bonner Scholar, and mentee of the Humphrey Fellows at Emory University. She has conducted research in the SUPERNOVA Lab and Phage Hunters Program at Spelman and previously worked in a neurobiology lab at Northwestern University as an NIH R25 Sleep and Circadian Scholar. In the Dean Lab, Aaniyah received a summer fellowship through the American Heart Association where she studies the influence of dietary protein on the liver-alpha cell axis, one of the Dean Lab's AHA funded projects. Upon graduating from Spelman, Aaniyah aspires to become a clinician-scientist focused on addressing the external determinants of health through biomedical research.
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Nelson Chang, M.S.
Exchange Student (Western University, London, Ontario)
Nelson joined the Dean lab in Spring 2024 to train as part of the NSERC CREATE externship program supported by the Canadian Islet Research Network. Nelson trained at Western University under Dr. Savita Dhanvantari. While at Vanderbilt, Nelson presented his research and won a poster award at the annual Vanderbilt Diabetes Day. Nelson recently defended his thesis and is completing his research studies in Ontario.
Joshua Debo, M.D.
Summer Medical Student (The Ohio State University). Currently, Josh is a PGY3 in Radiology at Rush University Medical Center in Chicago, IL.
Alex Dixon, B.S.
Undergraduate Student (Vanderbilt)
Alex grew up in Chatsworth, Georgia and initially attended Berry College as a Biochemistry student on a pre-med track. While there, he worked in the Johnson lab, where he assisted in computational drug optimization and research for defective Cystic Fibrosis Transmembrane Regulator
(CFTR) proteins. Alex was invited to the special "Sci-Mix" poster session at the ACS convention in San Diego, California to present this project. Alex then transferred to Vanderbilt to start his junior year in Biochemistry and Chemical Biology. In the Dean lab, Alex is focused on understanding how arginine transport influences islet cell proliferation. In his free time, Alex is a freelance musician and involved in Vanderbilt Music Outreach on campus. Alex graduated in May 2024 and is currently a strategy and insights analyst with 81qd, an AI-driven healthcare data analytics company in Atlanta, GA.
Gates Griffin
Undergraduate Student (Vanderbilt)
Gates is from Mount Airy, Maryland. A junior at Vanderbilt University majoring in Biological Sciences, he aspires to attend medical school and ultimately to specialize in orthopedics. During the school year, Gates volunteers as a Guest Ambassador at Vanderbilt University Medical Center. He is a member of his local volunteer fire department and is working toward completion of Emergency Medical Technician training through the Maryland Fire and Rescue Institute. Gates’s area of study is understanding how pancreatic islet alpha cells rewire mitochondrial metabolism to mitigate oxidative stress in response to hyperaminoacidemia. Gates graduated in May 2025 and is spending a gap year position as a research assistant at Harvard University in Ophthalmology.
Selma Alhajjaji
Undergraduate Student (Vanderbilt)
Selma is from Nashville, TN, and is a sophomore majoring in Biomedical Engineering. She was accepted into the V-START program to support her research. Selma is interested in diabetes research due to her experience living with Type One Diabetes and having other affected family members. While working in the Dean Lab, she focused on glutamine metabolism and its role in alpha cell expansion. Her long-term goal is to work in the biomedical engineering industry on projects related to Type One Diabetes.
Omar Amir, B.S.
Summer Medical Student (UT El Paso)
Ankitha Dyapa
Undergraduate Student (Vanderbilt)