Dr. Kwan Hee Kim
Research & Interests
The primary goal of my research is to understand the molecular and cellular mechanisms controlling embryonic and postnatal testis development and sperm production. A current focus is to determine the role of vitamin A (retinoids) and retinoid receptors in testicular cells in which both vitamin A and retinoid receptors have been shown to be essential for normal function. For example, vitamin A-deficient animals and transgenic mice carrying a mutated retinoid receptor gene are both sterile. Related to this, we are also interested to determine the mechanism by which alcohol and environmental toxins, also referred to as endocrine disruptors, interfere with normal retinoid signaling in the testis, resulting in abnormal testis development and reduced sperm production. To do this work, we use state-of-the art molecular and cellular techniques and in vivo animal model systems such as developing rats, environmental toxin- or alcohol-treated rats, vitamin A-deprived rats, and transgenic receptor knockout mice. Specific projects include: (1) identification of the mechanisms by which retinoid receptors are activated, (2) identification of the proteins directly induced by these receptors which are essential for testis function, and (3) identification of abnormal retinoid signaling mechanisms produced in fetal alcohol syndrome or during exposure to environmental toxins.
Bhattacharya, N., M-N. Vo, J. M. Dufour, J. R. Okita, R.T. Okita and K. H. Kim (2005), Differential effects of phthalates on the testis and liver. Biol. Reprod., 72, 745-754.
Li. H. and K. H. Kim (2004). Retinoic acid inhibits rat XY gonad development by blocking mesonepheric cell migration and decreasing the number of gonocytes. Biol. Reprod., 70, 687-693.
Li, H. and K. H. Kim (2003). Effects of Mono- (2-ethylhexyl) phthalate on fetal and neonatal rat testes in organ cultures. Biol. Reprod.,69,1964-1972.
Li, H. and K. H. Kim (2003). Effects of Ethanol on Embryonic and Neonatal Rat Testes in Organ Cultures. J. Androl., 24, 653-660.
Dufour, J.M., M-N. Vo, N. Bhattacharya, J. Okita, R. Okita and K. H. Kim (2003). Peroxisome proliferators disrupt retinoic acid receptor alpha signaling in the testis. Biol. Repro., 68, 1215-1224.
Braun, K.W., M-N. Vo, and K. H. Kim (2002). Positive Regulation of Retinoic Acid Receptor Alpha by Protein Kinase C and Mitogen Activated Protein Kinase in Sertoli Cells. Biol Reprod 67:29-37.
Braun, K. W., W. Tribley, M.D. Griswold, and K. H. Kim (2000). Follicle-stimulating hormone inhibits all-trans-retinoic acid-induced retinoid acid receptor a nuclear localization and transactivational activation in mouse Sertoli cell lines. J. Biol Chem. 275, 4145-4151.
Cupp, A.S., J. M. Dufour, G. Kim, M. K. Skinner, and K. H. Kim (1999). Action of retinoids on embryonic and early postnatal testis development. Endocrinology 140, 2343-2352.
Dufour, J. M. and K. H. Kim (1999). Cellular localization of six retinoid receptors in rat testis during postnatal development: Identification of potential heterodimeric receptors. Biol. Reprod. 61, 1300-1308.
Akmal, K. M., J. M. Dufour, M. Vo, S. Higginson, and K. H. Kim (1998). Ligand-dependent regulation of retinoic acid receptor a in rat testis: in vivo response to depletion and repletion of vitamin A. Endocrinology, 139, 1239-1248.