Paul S. H. Lee

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The bile salt export pump (BSEP) is an efflux transporter, driving the elimination of endobiotic and xenobiotic substrates from hepatocytes into the bile. More specifically, it is responsible for the elimination of monovalent, conjugated bile salts, with little or no assistance from other apical transporters. Disruption of BSEP activity through genetic(More)
Current GPCR cell-based assays often rely on the measurement of a loaded fluorescent dye, fluorescently tagged targets, or the expression of a reporter. These manipulations may alter the cellular physiology of the target GPCR, and the measurements may be subject to off-target interference of compounds. Label-free optical biosensor-based technologies that(More)
The Epic cell assay technology (Corning Inc., Corning, NY) uses a resonant waveguide grating optical biosensor to measure cellular response to ligands manifested through dynamic mass redistribution (DMR) of cellular contents. The DMR measurement is a noninvasive, label-free assay that can be used to assess the pharmacological properties of compounds. In(More)
The G protein-coupled receptor (GPCR) G2A (for G2 accumulation) was identified as a stress-inducible antiproliferative cell cycle regulator. Targeted G2A gene deletion in mice resulted in systemic lupus erythematosus-like and atherosclerotic lesion phenotypes. These findings suggested that G2A may be a therapeutic target for cancers and autoimmune and(More)
GPCRs had significant representation in the drug discovery portfolios of most major commercial drug discovery organizations for many years. This is due in part to the diverse biological roles mediated by GPCRs as a class, as well as the empirical discovery that they have proven relatively tractable to the development of small molecule therapeutics.(More)
High-throughput screening (HTS) has become an essential part of the drug discovery process. Due to the rising requirements for both data quality and quantity, along with increased screening cost and the demand to shorten the time for lead identification, increasing throughput and cost-effectiveness has become a necessity in the hit identification process.(More)
The use of plasma membrane vesicles that overexpress the bile salt export pump (BSEP) or multidrug resistance-associated protein 2, 3, or 4 (MRP2-4) with an in vitro vacuum filtration system offers a rapid and reliable means for screening drug candidates for their effects on transporter function in hepatocytes and thus their potential for causing(More)
Intracellular calcium response and resulting calcium signaling to an agonist-GPCR interaction are important for the measurement of compound activity in the GPCR drug development. The increase in cytosol calcium concentration can be measured by the fluorescent calcium indicator dye such as Fluo-4 in a quick assay (in 3-5 minutes) using the fluorescence(More)
The measurement of ligand receptor binding parameters for G-protein-coupled receptors is indispensable in the drug discovery process. Traditional ligand receptor binding assays require scale-up of cells and membrane preparations, which is an expensive and time-consuming process. In this report, the authors describe the development of a homogeneous live-cell(More)