Fluorescent cell-based assay system for SGLT1 and GLUT5 transporter screening

Overview

This offering is a fluorescent, cell-based assay system designed to study the activity of two key sugar transporters: Sodium glucose cotransporter protein 1 (SGLT1) and glucose transporter 5 (GLUT5). SGLT1 is responsible for glucose uptake while GLUT5 handles fructose transport, making both important targets for therapeutic intervention in metabolic disease and diabetes research.

The platform addresses a critical need in drug discovery: the ability to rapidly screen natural products, chemical libraries, and bioactive mixtures for compounds that modulate these transporters. Traditional carbohydrate uptake studies rely on radioactive isotopes, which carry significant cost, safety, and regulatory burdens. This assay replaces those methods with fluorescently labelled glucose and fructose derivatives that can be monitored in living cells using standard plate-reader equipment.

Technical specifications

Core technology components:

• Engineered human Caco-2 cell lines overexpressing SGLT1 or GLUT5, paired with matched control cell lines
• Fluorescent glucose derivative (2-NBDF) for measuring SGLT1-mediated uptake
• Fluorescent fructose derivative (6-NBDF) for measuring GLUT5-mediated uptake
• Validated reference inhibitors and activators for each transporter to confirm assay accuracy
• Dose-response protocols producing IC50 values and Z'-factor scores greater than 0.5 for high-quality screening
• Formats optimized for both 96-well and 384-well plate configurations
• Cryopreservation protocols with quality control metrics for stable cell line banking

Key advantages:

• Eliminates radioactive waste and associated licensing requirements
• Compatible with standard fluorescence plate readers already present in most screening laboratories
• Enables simultaneous testing of large compound libraries for activator or inhibitor activity
• Builds on validated expertise in fluorescent transport assay development, including a commercially released MDR1 drug interaction assay

Technology readiness level

The assay is currently in the development and optimization phase. Expression plasmids for SGLT1 and GLUT5 will be synthesized and transfected into Caco-2 human cell lines, with protein expression confirmed by Western blot. Following selection of overexpressing colonies, initial transport assays will be conducted using commercially sourced fluorescent probes and reference compounds. Assay performance will be evaluated using signal-to-background ratios and Z'-factor scoring. Protocols will then be optimized for medium- and high-throughput screening formats, with cryopreservation methods validated for long-term reproducibility. The development approach draws directly on prior successful assay development experience, including a published cholesterol efflux assay and a commercialized MDR1 transport assay, reducing technical risk and accelerating the path to a validated screening tool.