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Earl Harrison
Campbell Hall 341
(614) 292-4485
eharrison@ehe.osu.edu
Dean's Distinguished Professor of Human Nutrition
View Earl Harrison's curriculum vitae.
A.B. Chemistry, Cornell University, 1971
M.N.S. Nutrition, Cornell University, 1973
Ph.D. Nutritional Biochemistry, Columbia University, 1978
USPHS Postdoctoral Fellow, The Rockefeller University, 1979-1981
Vitamin A deficiency is one of the most widespread nutritional deficiencies in the developing world. In these areas, most individuals obtain their essential dietary vitamin A (retinol and its derivatives) as provitamin A carotenoids (eg. beta-carotene).
Our laboratory studies the basic mechanisms involved in the intestinal absorption, transport, and metabolism of dietary vitamin A and carotenoids using cell culture and animal models and investigations in human subjects. We are particularly interested in defining the proteins involved in the uptake and metabolism of dietary carotenoids in the intestine. We have demonstrated the facilitated uptake of carotenoids in CaCo2 cells in culture and identified the transporter proteins involved. We have also cloned and expressed the enzyme that cleaves beta-carotene to vitamin A. Current investigations focus on these and other enzymes and proteins involved in the intestinal metabolism of dietary carotenoids. Other studies focus on the role of carotenoids in vascular cell function with the goal of elucidating the mechanisms by which dietary carotenoids may decrease the risk of atherosclerosis.
Regardless of the form of vitamin A in the diet, after intestinal metabolism, most of the vitamin A enters the body as retinyl esters associated with intestinal lipoproteins called chylomicrons. These chylomicrons and the retinyl esters they contain are rapidly taken up by the liver which has the capacity to store large quantities of vitamin A. We study the enzymes known as retinyl ester hydrolases (REHs) that are important in both the uptake of dietary vitamin A by the liver and in the mobilization of stored vitamin A from the liver. Although a number of liver enzymes can catalyze the hydrolysis of vitamin A esters the molecular identity and physiological role of these enzymes is unclear. Our research attempts to fill these gaps in knowledge by isolating these proteins and studying their structure and function using techniques of biochemistry and molecular biology. Recent work focuses on the identification and characterization of members of the carboxylesterase enzyme family (particularly ES2, ES4 and ES10) as REHs involved in the uptake of chylomicron retinyl esters in liver.
A new area of investigation involves the use of proteomic profiling of plasma, using mass spectrometry and other techniques, to define new biomarkers of vitamin A nutritional status in experimental animal models.
During, A., M.M. Hussain, D.W. Morel, and E.H. Harrison (2002) Carotenoid uptake and secretion by caco-2 cells: beta-carotene isomer selectivity and carotenoid interactions. J. Lipid Res. 43: 1086-1095.
During, A. and E.H. Harrison (2004) Intestinal absorption and metabolism of carotenoids: Insights from cell culture. Arch. Biochem. Biophys. 430: 77-88.
During, A. and E.H. Harrison (2004) An in vitro model to study the intestinal absorption of carotenoids. In: Pigments in Food, More Than Colours (Dufosse, L., editor) Universite de Bretagne Occidentale, Quimper, France. pp. 262-264.
Linke,T., A.C. Ross and E.H. Harrison (2004) SELDI-TOF MS profiling of rat plasma: a novel tool for biomarker discovery in nutrition research. J. Chromatography A 1043: 65-71.
McDevitt, T.M., R. Tchao, E.H. Harrison, and D.W. Morel (2005) Carotenoids normally present in serum inhibit proliferation and induce differentiation of a human monocyte/macrophage cell line (U937). J. Nutr. 135: 160-164.
Linke,T., H. Dawson and E.H. Harrison (2005) Microsomal acid retinyl ester hydrolase: Isolation, characterization, substrate and tissue specificity. J. Biol. Chem. 280: 23287-23294.
Harrison, E.H. (2005) Mechanisms of digestion and absorption of dietary vitamin A. Ann. Rev. Nutr. 25: 87-103.
During, A. and E.H. Harrison (2005) An in vitro model to study the intestinal absorption of carotenoids. Food Research International 38: 1001-1008.
During, A., H. Dawson and E.H. Harrison (2005) Carotenoid transport is decreased and expression of the lipid transporters SR-BI, NPC1L1 and ABCA1 is down-regulated in CACO-2 cells treated with ezetimibe. J. Nutr. 135: 2305-2312.
Linke, T., A.C. Ross and E.H. Harrison (2006) Proteomic analysis of rat plasma by two-dimensional liquid chromatography and MALDI-TOF mass spectrometry. J. Chromatography A 1123: 160-169.
During A. and E.H. Harrison (2006) Digestion and Intestinal Absorption of Dietary Carotenoids and Vitamin A. In: Physiology of the Gastrointestinal Tract, Fourth Edition, edited by Leonard R. Johnson. Academic Press.
Linke, T., S. Doraiswamy and E.H. Harrison (2007) Rat plasma proteomics: Effects of abundant protein depletion on proteomic analysis. J Chromatography B 849: 273-281.
Trasino, S.E., E.H. Harrison and T.Y. Wang (2007) Androgen regulation of aldehyde dehydrogenase 1A3 (ALDH1A3) in the androgen responsive human prostate cancer cell LNCaP. Exp. Biol. Med. 232: 762-771.
Ross, A.C. and E.H. Harrison (2007) Vitamin A: Nutritional Aspects of Retinoids and Carotenoids. In Handbook of Vitamins, Fourth Edition, edited by Robert B. Rucker. Marcel Dekker, New York. Chapter 1; pp 1-39.
During, A. and E.H. Harrison (2007) Mechanisms of provitamin A (carotenoid) and vitamin A (retinol) transport into and out of intestinal Caco-2 cells. J. Lipid Res. 48: 2283-2294.
To view all of Earl Harrison's publications, visit the PubMed website and search for 'harrison eh'.