Development of a novel non-radioactive cell-based method for the screening of SGLT1 and SGLT2 inhibitors using 1-NBDG

Mol Biosyst. 2013 Aug;9(8):2010-20. doi: 10.1039/c3mb70060g. Epub 2013 May 8.

Abstract

Sodium-coupled glucose co-transporters SGLT1 and SGLT2 play important roles in intestinal absorption and renal reabsorption of glucose, respectively. Blocking SGLT2 is a novel mechanism for lowering the blood glucose level by inhibiting renal glucose reabsorption and selective SGLT2 inhibitors are under development for treatment of type 2 diabetes. Furthermore, it has been reported that perturbation of SGLT1 is associated with cardiomyopathy and cancer. Therefore, both SGLT1 and SGLT2 are potential therapeutic targets. Here we report the development of a non-radioactive cell-based method for the screening of SGLT inhibitors using COS-7 cells transiently expressing human SGLT1 (hSGLT1), CHO-K1 cells stably expressing human SGLT2 (hSGLT2), and a novel fluorescent d-glucose analogue 1-NBDG as a substrate. Our data indicate that 1-NBDG can be a good replacement for the currently used isotope-labeled SGLT substrate, (14)C-AMG. The Michaelis constant of 1-NBDG transport (0.55 mM) is similar to that of d-glucose (0.51 mM) and AMG (0.40 mM) transport through hSGLT1. The IC50 values of a SGLT inhibitor phlorizin for hSGLT1 obtained using 1-NBDG and (14)C-AMG were identical (0.11 μM) in our cell-based system. The IC50 values of dapagliflozin, a well-known selective SGLT2 inhibitor, for hSGLT2 and hSGLT1 determined using 1-NBDG were 1.86 nM and 880 nM, respectively, which are comparable to the published results obtained using (14)C-AMG. Compared to (14)C-AMG, the use of 1-NBDG is cost-effective, convenient and potentially more sensitive. Taken together, a non-radioactive system using 1-NBDG has been validated as a rapid and reliable method for the screening of SGLT1 and SGLT2 inhibitors.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 4-Chloro-7-nitrobenzofurazan / analogs & derivatives*
  • 4-Chloro-7-nitrobenzofurazan / chemical synthesis
  • 4-Chloro-7-nitrobenzofurazan / metabolism
  • Animals
  • Biological Transport
  • CHO Cells
  • COS Cells
  • Chlorocebus aethiops
  • Cricetulus
  • Fluorescent Dyes / chemical synthesis*
  • Fluorescent Dyes / metabolism
  • Gene Expression
  • Glucosamine / analogs & derivatives*
  • Glucosamine / chemical synthesis
  • Glucosamine / metabolism
  • Glucose / analogs & derivatives*
  • Glucose / chemical synthesis*
  • Glucose / metabolism
  • Humans
  • Kinetics
  • Molecular Probes / chemical synthesis*
  • Molecular Probes / metabolism
  • Phlorhizin / chemistry
  • Phlorhizin / pharmacology
  • Sodium-Glucose Transporter 1 / antagonists & inhibitors*
  • Sodium-Glucose Transporter 1 / genetics
  • Sodium-Glucose Transporter 1 / metabolism
  • Sodium-Glucose Transporter 2 / genetics
  • Sodium-Glucose Transporter 2 / metabolism
  • Sodium-Glucose Transporter 2 Inhibitors*
  • Spectrometry, Fluorescence

Substances

  • Fluorescent Dyes
  • Molecular Probes
  • SLC5A1 protein, human
  • SLC5A2 protein, human
  • Sodium-Glucose Transporter 1
  • Sodium-Glucose Transporter 2
  • Sodium-Glucose Transporter 2 Inhibitors
  • 6-deoxy-N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)aminoglucose
  • Phlorhizin
  • 4-Chloro-7-nitrobenzofurazan
  • Glucose
  • Glucosamine