Jed N Lampe, Ph.D.
Research Associate Professor
Ph.D., University of Washington, 2007
The Lampe laboratory utilizes bioanalytical, biophysical, and computational tools and techniques to understand structure-function relationships in proteins involved in neonatal and infant drug metabolism and transport. Ultimately, our goal is to use the knowledge obtained to improve the safety and efficacy of new and current drugs prescribed to neonates and infants. Currently, there are two major research initiatives in my lab:
1. Understanding the role of cytochrome P450 CYP3A7 in drug metabolism and toxicity in the infant The liver metabolizes the vast majority of the drugs that enter our bodies, however there are significant developmental differences between infant and adult livers. Our goal is to determine the specific differences in drug metabolism between the infant and adult liver and the possible implications for drug toxicity in developing infants. Cytochrome P450 CYP3A7 is the most abundant drug detoxifying enzyme expressed in infants from before birth until 12 months of age, yet little is known of its role in metabolizing many common drugs that are given to newborns. The HIV reverse transcriptase inhibitor Nevirapine, a CYP3A7 substrate, is quickly becoming the standard of care for newborns of HIV infected mothers, yet the safety profile of this drug has not been examined in neonates. The adult liver is thought to produce a reactive quinone methide metabolite from Nevirapine that can lead to liver injury. Work in our laboratory has demonstrated that CYP3A7 can indeed metabolize Nevirapine and produce the toxic reactive quinone methide metabolite. Additionally, we have demonstrated that CYP3A7 is not subject to time-dependent inactivation kinetics with Nevirapine, indicating that neonates prescribed with this drug may be at increased risk for both drug-drug interactions and hepatic idiosyncratic toxicity, as seen in the adult population. The results of this work will give care providers critically needed information when prescribing lifesaving drugs to treat HIV infection and AIDS in the pediatric population.
2. Determining the mechanism of substrate binding and translocation in organic cationic drug transporters expressed in the infant The human organic cation transporter 1 (OCT1), an important polyspecific transporter of the SLC22 class, is involved in the uptake and transport of a wide variety of cationic drugs and endogenous compounds. It is one of the most abundant drug transporters expressed in the infant liver, but significant amounts are also found in the heart, brain, and placenta. Recent work has demonstrated that polymorphisms in this transporter can greatly diminish the efficacy of certain drugs, including the antidiabetic agent metformin and the antineoplastic agent imatinib. Despite its important role in drug disposition and efficacy, little is known regarding the molecular details of ligand binding and transport in OCT1. Therefore, our goal is to understand the structural and functional characteristics of OCT1, including the basis for substrate and inhibitor selectivity, in hopes of using this knowledge to improve opportunities for cationic drug discovery and design. Although OCT1 is known to transport a variety of drugs, its endogenous substrate selectivity has not been clearly defined. Recently, we have established that several cationic neurotransmitters, including serotonin, are transported by OCT1 into the liver for further metabolism and degradation. Our lab has additionally demonstrated that OCT1 drug substrates can compete with serotonin for uptake into the liver, suggesting a risk of adverse drug-endogenous metabolite interactions that could lead to toxicity in some cases. Ultimately, this knowledge will lead to the development of safer and more effective medicines with less risk for drug-drug interactions.
Selected Publications (of 22):
Bishop, S.C., Keightley, A.J., Anbanandam, A., Lampe, J.N. (2018). Synthesis of a clickable lanthanide chelator for high throughput screening of protein-protein interaction inhibitors. Manuscript in Preparation to be submitted to: J. Med. Chem. Lett.
Boxberger, K.H., Hagenbuch, B., Lampe, J.N. (2018). Ligand-dependent modulation of OCT1 transport by cationic substrates and the negatively charged anion, BSP. Biochem. Pharm. In press.
Kandel, S.E., Han, L.W., Mao, Q., Lampe, J.N. (2017). Digging deeper into CYP3A testosterone metabolism: kinetic, regio- and stereoselectivity differences between CYP3A4/5 and CYP3A7. Drug Metab. Dispo. 45: 1266-1275, PMID: 28986474.
Lampe, JN. (2017). Emerging biophysical techniques to monitor protein-protein interaction in drug metabolizing enzymes. Front. Pharmacol. 8: 521-534, PMID: 28848438.
Beggs, K.M., McGreal, S.R., McCarthy, A., Gunewardena, S., Lampe, J.N., Lau, C., Apte, U. (2016). The role of hepatocyte nuclear factor 4-alpha in perfluorooctanoic acid- and perfluorooctanesulfonic acid-induced hepatocellular dysfunction. Toxicol. Appl. Pharmacol. 304: 18-29, PMID: 27153767.
Basudhar, D., Madrona, Y., Kandel, S., Lampe, J.N., Nishida, C.R., Ortiz de Montellano, P.R. (2015). Analysis of cytochrome P450 CYP119 ligand-dependent conformational dynamics by two-dimensional NMR and X-ray crystallography. J. Biol. Chem. 290:10000-17.
Kandel, S.K., Lampe, J.N. (2014). The role of Protein-Protein Interactions in Cytochrome P450 Mediated Drug Metabolism and Toxicity. Chem. Res. Tox. 27:1474-86.
Kandel, S.K., Wienkers, L.C., Lampe, J.N. (2014). Cytochrome P450 Enzyme Metabolites in Lead Discovery and Development. Annu. Rep. Med. Chem. 49, 347-357.
Boxberger, K.H., Hagenbuch, B., Lampe, J.N. (2014). Common drugs inhibit human organic cation transporter 1 (OCT1)-mediated neurotransmitter uptake. Drug. Metab. Dispos. 42, 990-995.
Varfaj, F., Lampe, J.N., Ortiz de Montellano, P.R. (2012). Role of Cysteine Residues in Heme Binding to Human Heme Oxygenase-2 Elucidated by 2D NMR Spectroscopy. J. Biol. Chem. 287, 35181-35191.
Williams, C.D., Koerner, M.R., Lampe, J.N., Farhood, A., Jaeschke, H. (2011). Mouse strain-dependent caspase activation during acetaminophen hepatotoxicity does not result in apoptosis or modulation of inflammation. Toxicol. Appl. Pharmacol. 257, 449-58.
Brandman, R., Lampe, J.N., Brandman, Y., Ortiz de Montellano, P.R. (2011). Active-site residues move independently from the rest of the protein in a 200ns molecular dynamics simulation of cytochrome P450 CYP119. Arch. Biochem. Biophys. 506, 9594-9603.
Lampe, J.N., Brandman, R., Sivaramakrishnan, S., and Ortiz de Montellano, P. R. (2010). Two-dimensional NMR and all-atom molecular dynamics of cytochrome P450 CYP119 reveal hidden conformational substates. J. Biol. Chem. 285, 9594-9603.
Lampe, J.N., Floor, S. N., Gross, J. D., Nishida, C. R., Jiang, Y., Trnka, M. J., and Ortiz de Montellano, P. R. (2008). Ligand-induced conformational heterogeneity of cytochrome P450 CYP119 identified by 2D NMR spectroscopy with the unnatural amino acid 13C-p -methoxyphenylalanine. J. Am. Chem. Soc., 130, 16168-16169.
Nath, A., Fernandez, C., Lampe, J.N., and Atkins, W. M. (2008). Spectral resolution of a second binding site for Nile Red on cytochrome P4503A4. Arch. Biochem. Biophys. 474, 198-204.
Lampe, J.N., Fernandez, C., Nath, A., and Atkins, W.M. (2007). Nile Red is a fluorescent allosteric substrate of cytochrome P450 3A4. Biochemistry 47, 509-516.