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E. Danielle Dean, Ph.D.
Principal Investigator

Assistant Professor of Medicine, Division of Diabetes, Endocrinology and Metabolism
Assistant Professor of Molecular Physiology and Biophysics

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. 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. She started her independent laboratory at Vanderbilt in 2019. 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.



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Jade E. Stanley, B.S.

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. Currently, Jade is 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.


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 searching for new pharmacological strategies to ultimately promote the reprogramming of endogenous human pancreatic islet alpha cells to secrete insulin.

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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. 


Madushika Wilmarenthe, 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.

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Alex Dixon

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. He aspires to one day become a MD/PhD, specializing in cardiology and cardiac drug research.


Ankitha Dyapa

Undergraduate Student (Vanderbilt)


Ankitha is from Brentwood, TN and is a sophomore at Vanderbilt University majoring in Psychology and minoring in South Asian Languages and Culture. In her free time, Ankitha is a dancer and is involved in two dance teams on campus. She plans to attend medical school and specialize in either psychiatry, pediatrics, or radiology. Her interest in diabetes research is rooted by her family members who suffer from the disease. Her work in the Dean Lab focuses on how dietary protein affects exocrine and endocrine mass.

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Angelina Ehara

Undergraduate Student (Vanderbilt)


Angelina is currently attending Vanderbilt University as a Neuroscience and Medicine, Health, and Society major on a pre-med track. She is an aspiring neurosurgeon and interested in a career as a physician scientist in clinical neuroscience. Her primary research interests are 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 recently accepted into the VUSRP program at Vanderbilt.


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.


Sarah Qaddo

Undergraduate Student (Vanderbilt)


Sarah grew up in Knoxville, TN and is now a sophomore at Vanderbilt University majoring in Neuroscience and Medicine, Health, and Society with a minor in Spanish. 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 focuses on glutamine transport and metabolism in alpha cells using stable isotope tracing.

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Tyler Rodgers

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.


Soham Saraf

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 recently awarded a 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. After completing his bachelors, Soham hopes to enroll in medical school and pursue an MD/PhD, specializing in either endocrinology or infectious diseases.

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Nitin Shankar

Undergraduate Student (Vanderbilt)


Nitin grew up in Columbus, Ohio and is currently a sophomore at Vanderbilt University interested in majoring in Medicine, Heath & Society and Economics. While in high school, Nitin co-founded a research project with a researcher at Ohio State University related to epidemiology to understand the genetic link between lactose intolerance and colorectal cancer. In the Dean Lab, he is currently helping 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.

Former Lab Members


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. 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. Currently, Walt is a rising 3rd year medical student at University of Tennessee.


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 as a gap year student. Matthew's work in the lab 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. Currently, Matthew is a rising 2nd year medical student at Vanderbilt University.

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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.


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. She is currently a OMS-II medical student at an osteopathic medical school, University of Pikeville Kentucky College of Osteopathic Medicine. Now, Mounika is spending the summer 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 rising 2nd year medical students.

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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 plans to go to graduate school to research interventions to regenerate beta-cell mass in a diabetic person’s pancreas, as well as target insulin signaling in the brain, which would aid in treatments for neurodegenerative diseases.

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Varsha Chigurupati

Summer Undergraduate Student (Nova SEU)


Varsha grew up in Franklin, TN where she attended Fred J. Page High School. She is now attending Nova Southeastern University in Fort Lauderdale, FL to pursue a career in medicine. She aspires to become a pediatric surgeon one day. Her interests in diabetes research are rooted by her family members because many are suffering with diabetes. Her targeted work in the lab includes understanding glutamine transport and metabolism in pancreatic islet alpha cells and its role in amino acid induced alpha cell proliferation.

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Joshua Debo, B.S.


Summer Medical Student (The Ohio State University)

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Omar Amir, B.S.

Summer Medical Student (UT El Paso)



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