Erika Danielle Dean, Ph.D.

Assistant Professor
Faculty Appointments
Assistant Professor of Medicine Assistant Professor of Molecular Physiology & Biophysics
Ph.D., Molecular and Systems Pharmacology, Emory University, Atlanta, GeorgiaM.S., Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, TennesseeB.S., Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
Research Description
The Dean lab seeks to understand how nutritional and other environmental factors affect pancreatic islet cell function and proliferation. Islet alpha cells secrete glucagon in response to hypoglycemia leading to increased glucose output by liver, but persons with diabetes often have hyperglucagonemia further contributing to hyperglycemia. Very little is known about signals regulating alpha cells. We have used a mouse model with interrupted glucagon signaling that displays alpha cell hyperplasia and hyperglucagonemia to identify circulating factors that stimulate alpha cell proliferation. We described that these circulating factors are amino acids defining a novel hepatic-pancreatic islet alpha cell axis that is conserved across vertebrate species. The Dean lab is current interested in 1) defining the mechanism of how amino acids are sensed by alpha cells to stimulate proliferation and glucagon secretion and 2) investigating the role of amino acids on alpha cell dysfunction in diabetes.
Research Keywords
diabetes; glucagon; liver; pancreatic islet; alpha cell; amino acid; glutamine; arginine; alanine; transport; metabolism; RNASeq; metabolomics; glutaminase; transporters; hyperaminoacidemia; hyperglucagonemia
Saunders DC, Brissova M, Phillips N, Shrestha S, Walker JT, Aramandla R, Poffenberger G, Flaherty DK, Weller KP, Pelletier J, Cooper T, Goff MT, Virostko J, Shostak A, Dean ED, Greiner DL, Shultz LD, Prasad N, Levy SE, Carnahan RH, Dai C, Sévigny J, Powers AC. Ectonucleoside Triphosphate Diphosphohydrolase-3 Antibody Targets Adult Human Pancreatic ß Cells for In Vitro and In Vivo Analysis. Cell Metab [print-electronic]. 2019 Mar 3/5/2019; 29(3): 745-754.e4. PMID: 30449685, PMCID: PMC6402969, PII: S1550-4131(18)30639-9, DOI: 10.1016/j.cmet.2018.10.007, ISSN: 1932-7420.

Bozadjieva N, Blandino-Rosano M, Chase J, Dai XQ, Cummings K, Gimeno J, Dean E Danielle, Powers AC, Gittes GK, Rüegg MA, Hall MN, MacDonald PE, Bernal-Mizrachi E. Loss of mTORC1 signaling alters pancreatic a cell mass and impairs glucagon secretion. J. Clin. Invest. 2017 Dec 12/1/2017; 127(12): 4379-93. PMID: 29106387, PMCID: PMC5707167, PII: 90004, DOI: 10.1172/JCI90004, ISSN: 1558-8238.

Dean ED, Li M, Prasad N, Wisniewski SN, Von Deylen A, Spaeth J, Maddison L, Botros A, Sedgeman LR, Bozadjieva N, Ilkayeva O, Coldren A, Poffenberger G, Shostak A, Semich MC, Aamodt KI, Phillips N, Yan H, Bernal-Mizrachi E, Corbin JD, Vickers KC, Levy SE, Dai C, Newgard C, Gu W, Stein R, Chen W, Powers AC. Interrupted Glucagon Signaling Reveals Hepatic a Cell Axis and Role for L-Glutamine in a Cell Proliferation. Cell Metab. 2017 Jun 6/6/2017; 25(6): 1362-1373.e5. PMID: 28591638, PMCID: PMC5572896, PII: S1550-4131(17)30300-5, DOI: 10.1016/j.cmet.2017.05.011, ISSN: 1932-7420.

Dean ED, Unger RH, Holland WL. Glucagon antagonism in islet cell proliferation. Proc. Natl. Acad. Sci. U.S.A [print-electronic]. 2017 Mar 3/21/2017; 114(12): 3006-8. PMID: 28283660, PMCID: PMC5373377, PII: 1700468114, DOI: 10.1073/pnas.1700468114, ISSN: 1091-6490.

Li M, Dean ED, Zhao L, Nicholson WE, Powers AC, Chen W. Glucagon receptor inactivation leads to a-cell hyperplasia in zebrafish. J. Endocrinol. 2015 Nov; 227(2): 93-103. PMID: 26446275, PMCID: PMC4598637, PII: 227/2/93, DOI: 10.1530/JOE-15-0284, ISSN: 1479-6805.

Longuet C, Robledo AM, Dean ED, Dai C, Ali S, McGuinness I, de Chavez V, Vuguin PM, Charron MJ, Powers AC, Drucker DJ. Liver-specific disruption of the murine glucagon receptor produces a-cell hyperplasia: evidence for a circulating a-cell growth factor. Diabetes [print-electronic]. 2013 Apr; 62(4): 1196-205. PMID: 23160527, PMCID: PMC3609565, PII: db11-1605, DOI: 10.2337/db11-1605, ISSN: 1939-327X.