Biomedical Research Education & Training
Faculty Member

Keeney, Diane S., Ph.D.
Adjunct Assistant Professor of Medicine

Lab Url: N/A

Phone Number: 615-322-3318

Email Address: diane.keeney@vanderbilt.edu

Keeney, Diane's picture
Academic history
B.S., Pennsylvania State
M.S., Iowa State
Ph.D., Johns Hopkins

Office Address   Mailing Address

F320 Acre Bldg; mail only: 607 Light Hall Vanderbilt University
Nashville, TN 37232-0146

607 Light Hall 37232-0146


Research Keywords
epithelial differentiation, lipid mediators, cytochrome P450 enzymes, signal transduction, metabolism,Biochemistry,Toxicology

Research Specialty
We study roles for cytochrome P450 enzymes in the regulation of epithelial differentiation.

Research Description
Stratified squamous epithelia are self-renewing and directly interface the environment. In mammals, they comprise competent barriers that provide protection against hostile environmental elements; consequently, they are primary sites of disease, including cancer. Proliferating keratinocytes from different stratified squamous epithelia have many similarities, but their terminal differentiation programs are quite distinct. For example, the outer cell layer of the epidermis is anucleated, dry, and relatively impermeable; that in oral epithelium is nucleated, wet, and relatively permeable. Phenotype reversal at these sites would be fatal. We are studying mechanisms that regulate these disparate phenotypes during terminal differentiation and role for cytochrome P450-derived metabolites in these processes.
Skin expresses many cytochromes P450 (CYP genes) having critical roles in endogenous and exogenous substrate metabolism (e.g., therapeutic drugs, xenobiotics, fatty acids, eicosanoids, sterols, steroids, vitamins A & D). We characterized three homologous P450s in rodent skin (CYP2B19, 2B15, 2B12). Mouse CYP2B19 and rat CYP2B12 were found to be arachidonic acid epoxygenases, which generate epoxyeicosatrienoic (EET) acids. These P450 enzymes were detected only in differentiated keratinocytes comprising the outer epithelial cell layers, and this cell-specific transcriptional regulation suggested important roles for these enzymes in the production and/or disposition of molecules affecting keratinocyte differentiation and epidermal functions.
EETs are natural epoxy fatty acids formed in cutaneous tissues and in cultured keratinocytes. In keratinocyte cultures, the CYP2B19 metabolite 14,15-EET activated transglutaminase enzyme activities and promoted cell cornification. In present studies, we aim to understand the mechanisms how P450-derived epoxy fatty acids regulate these cellular processes, which are critical to establishing a competent epidermal barrier. In other ongoing projects, we aim to identify functional homologues in human epidermis responsible for generating epoxy fatty acids and to develop a Cyp2b19 null mouse. These in vitro and in vivo studies will generate new insight into how endogenously formed lipid mediators (EETs) regulate functions of epidermal keratinocytes that are responsible for forming the stratum corneum and the water permeability barrier in mammals.
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Publications
Du, Liping, Hoffman, Susan M G, Keeney, Diane S. Epidermal CYP2 family cytochromes P450. Toxicol Appl Pharmacol, 195(3), 278-87, 2004

Du, L., Hoffman, S.M.G., and Keeney, D.S.. Epidermal CYP2 family cytochromes P450.. Toxicol. Appl. Pharmacol. , in press, 2003

Ladd, Patricia A., Du, Liping, Capdevila, Jorge H., Mernaugh, Raymond, Keeney, Diane S.. Epoxyeicosatrienoic acids activate transglutaminases in situ and induce cornification of epidermal keratinocytes.. J Biol Chem, 2003

Wang, H., Donley, K.M., Keeney, D.S., and Hoffman, S.M.G.. Organizaton and evolution of the CYP2 gene cluster on mouse chromosome 7, and a comparison to the syntenic human cluster.. Environ. Health Perspec. Toxicogenomics , in press, 2003

Hoffman, Susan M G, Keeney, Diane S. Fine-scale mapping of CYP gene clusters: an example from human CYP4 family.. Methods Enzymol, 357, 36-44, 2002

Hoffman, S M, Nelson, D R, Keeney, D S. Organization, structure and evolution of the CYP2 gene cluster on human chromosome 19.. Pharmacogenetics, 11(8), 687-98, 2001

Holla, V R, Adas, F, Imig, J D, Zhao, X, Price, E, Olsen, N, Kovacs, W J, Magnuson, M A, Keeney, D S, Breyer, M D, Falck, J R, Waterman, M R, Capdevila, J H. Alterations in the regulation of androgen-sensitive Cyp 4a monooxygenases cause hypertension.. Proc Natl Acad Sci U S A, 98(9), 5211-6, 2001 PMCID:33189

Schneider, C, Keeney, D S, Boeglin, W E, Brash, A R. Detection and cellular localization of 12R-lipoxygenase in human tonsils.. Arch Biochem Biophys, 386(2), 268-74, 2001

Shappell, S B, Keeney, D S, Zhang, J, Page, R, Olson, S J, Brash, A R. 15-Lipoxygenase-2 expression in benign and neoplastic sebaceous glands and other cutaneous adnexa.. J Invest Dermatol, 117(1), 36-43, 2001

Keeney, D.S . Radiolabeled cRNA and In Situ Hybridization. Systematic Approach (Sundberg, J.P. and Bogess, D., eds.) , 145-167 , 2000

Brash, A R, Jisaka, M, Boeglin, W E, Chang, M S, Keeney, D S, Nanney, L B, Kasper, S, Matusik, R J, Olson, S J, Shappell, S B. Investigation of a second 15S-lipoxygenase in humans and its expression in epithelial tissues.. Adv Exp Med Biol, 469, 83-9, 1999

Keeney, D S, Waterman, M R. Two novel sites of expression of NADPH cytochrome P450 reductase during murine embryogenesis: limb mesenchyme and developing olfactory neuroepithelia.. Dev Dyn, 216(4-5), 511-7, 1999

Keeney, D.S. and Waterman, M.R . Two novel sites of expression of NADPH cytochrome P450 reductase during murine embryogenesis: limb mesenchyme and developing olfactory neuroepithelia. Develop. Dynamics , 216, 511-517, 1999

Keeney, D S. The novel skin-specific cytochrome P450 Cyp2b19 maps to proximal chromosome 7 in the mouse, near a cluster of Cyp2 family genes.. Genomics, 53(3), 417-9, 1998

Keeney, D S, Skinner, C, Travers, J B, Capdevila, J H, Nanney, L B, King, L E, Waterman, M R. Differentiating keratinocytes express a novel cytochrome P450 enzyme, CYP2B19, having arachidonate monooxygenase activity.. J Biol Chem, 273(48), 32071-9, 1998

Keeney, D S, Skinner, C, Wei, S, Friedberg, T, Waterman, M R. A keratinocyte-specific epoxygenase, CYP2B12, metabolizes arachidonic acid with unusual selectivity, producing a single major epoxyeicosatrienoic acid.. J Biol Chem, 273(15), 9279-84, 1998

Keeney, D.S. The novel skin-specific cytochrome P450, Cyp2b19, maps to proximal Chromosome 7 in the mouse, near a cluster of Cyp2 family genes. Genomics, 53, 417-419, 1998

Keeney, D.S., Skinner, C., Travers, J.B., Capdevila, J.H., Nanney, L.B., King Jr., L.E., and Waterman, M.R. Differentiating keratinocytes express a novel cytochrome P450 enzyme, CYP2B19, having arachidonate oxygenase activity. J. Biol. Chem., 273, 32071-32079, 1998

Keeney, D.S., Skinner, C., Wei, S., Friedberg, T., and Waterman, M.R. A keratinocyte-specific epoxygenase, CYP2B12, metabolizes arachidonic acid with unusual selectivity, producing a single major epoxyeicosatrienoic acid. J. Biol. Chem., 273, 9279-9284, 1998

Mason, J I, Keeney, D S, Bird, I M, Rainey, W E, Morohashi, K, Leers-Sucheta, S, Melner, M H. The regulation of 3 beta-hydroxysteroid dehydrogenase expression.. Steroids, 62(1), 164-8, 1997

Funk, C D, Keeney, D S, Oliw, E H, Boeglin, W E, Brash, A R. Functional expression and cellular localization of a mouse epidermal lipoxygenase.. J Biol Chem, 271(38), 23338-44, 1996

Str??mstedt, M, Keeney, D S, Waterman, M R, Paria, B C, Conley, A J, Dey, S K. Preimplantation mouse blastocysts fail to express CYP genes required for estrogen biosynthesis. Mol Reprod Dev, 43(4), 428-36, 1996

Waterman, M R, Keeney, D S. Signal transduction pathways combining peptide hormones and steroidogenesis.. Vitam Horm, 52, 129-48, 1996

Keeney, D S. Perspectives in steroid hydroxylase gene expression: novel sites of expression during embryonic development. Endocr Res, 21(1-2), 103-7, 1995

Keeney, D S, Ikeda, Y, Waterman, M R, Parker, K L. Cholesterol side-chain cleavage cytochrome P450 gene expression in the primitive gut of the mouse embryo does not require steroidogenic factor 1.. Mol Endocrinol, 9(8), 1091-8, 1995

Keeney, D S, Jenkins, C M, Waterman, M R. Developmentally regulated expression of adrenal 17 alpha-hydroxylase cytochrome P450 in the mouse embryo.. Endocrinology, 136(11), 4872-9, 1995

Jarow, J P, Keeney, D S, Robaire, B, Ewing, L L, Zirkin, B R. In vivo model for chronic direct intratesticular drug administration.. J Androl, 15(5), 456-61, 1994

Keeney, D S, Murry, B A, Bartke, A, Wagner, T E, Mason, J I. Growth hormone transgenes regulate the expression of sex-specific isoforms of 3 beta-hydroxysteroid dehydrogenase/delta 5-->4-isomerase in mouse liver and gonads.. Endocrinology, 133(3), 1131-8, 1993

Keeney, D S, Naville, D, Milewich, L, Bartke, A, Mason, J I. Multiple isoforms of 3 beta-hydroxysteroid dehydrogenase/delta 5-->4-isomerase in mouse tissues: male-specific isoforms are expressed in the gonads and liver.. Endocrinology, 133(1), 39-45, 1993

Keeney, D S, Waterman, M R. Regulation of steroid hydroxylase gene expression: importance to physiology and disease.. Pharmacol Ther, 58(3), 301-17, 1993

Keeney, D S, Mason, J I. Expression of testicular 3 beta-hydroxysteroid dehydrogenase/delta 5----4-isomerase: regulation by luteinizing hormone and forskolin in Leydig cells of adult rats.. Endocrinology, 130(4), 2007-15, 1992

Waterman, M R, Keeney, D S. Genes involved in androgen biosynthesis and the male phenotype.. Horm Res, 38(5-6), 217-21, 1992

Naville, D, Keeney, D S, Jenkin, G, Murry, B A, Head, J R, Mason, J I. Regulation of expression of male-specific rat liver microsomal 3 beta-hydroxysteroid dehydrogenase.. Mol Endocrinol, 5(8), 1090-100, 1991

Keeney, D S, Ewing, L L. Effects of hypophysectomy and alterations in spermatogenic function on Leydig cell volume, number, and proliferation in adult rats.. J Androl, 11(4), 367-78, 1990

Keeney, D S, Sprando, R L, Robaire, B, Zirkin, B R, Ewing, L L. Reversal of long-term LH deprivation on testosterone secretion and Leydig cell volume, number and proliferation in adult rats.. J Endocrinol, 127(1), 47-58, 1990

Mendis-Handagama, S M, Keeney, D S, Hardy, M P, Ewing, L L. Application of the disector method to enumerate cells in the testis.. Ann N Y Acad Sci, 564, 86-98, 1989

Juniewicz, P E, Keeney, D S, Ewing, L L. Effect of adrenocorticotropin and other proopiomelanocortin-derived peptides on testosterone secretion by the in vitro perfused testis.. Endocrinology, 122(3), 891-8, 1988


Postdoctoral Position Available
No

Postdoctoral Position Details
N/A

Updated Date
09/04/2003