A Fluorescent Glucose Transport Assay for Screening SGLT2 Inhibitors in Endogenous SGLT2-Expressing HK-2 Cells

The sodium-dependent glucose transporters 2 (SGLT2) plays important role in renal reabsorption of urinal glucose back to plasma for maintaining glucose homeostasis. The approval of SGLT2 inhibitors for treatment of type 2 diabetes highlights the SGLT2 as a feasible and promising drug target in recent years. Current methods for screening SGLT2 inhibitors are complex, expensive and labor intensive. Particularly, these methods cannot directly measure nonradioactive glucose uptake in endogenous SGLT2-expressing kidney cells. In present work, human kidney cells, HK-2, was incubated with a fluorescent D-glucose derivant 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-D-glucose (2-NBDG) and the fluorescent intensity of 2-NBDG was employed to measure the amount of glucose uptake into the cells. By optimizing the passages of HK-2 cells, 2-NBDG concentration and incubation time, and by measuring glucose uptake treated by Dapagliflozin, a clinical drug of SGLT2 inhibitors, we successfully developed a new assay for measuring glucose uptake through SGLT2. The nonradioactive microplate and microscope-based high-throughput screening assay for measuring glucose can be a new method for screening of SGLT2 inhibitors and implied for other cell assays for glucose measurement extensively.