3-Deoxyglucosone reduces glucagon-like peptide-1 secretion at low glucose levels through down-regulation of SGLT1 expression in STC-1 cells

Abstract

Context

Sodium glucose co-transporter 1 (SGLT1) triggers low glucose-induced glucagon-like peptide-1 (GLP-1) secretion. We reported that a two-week administration of 3-deoxyglucosone (3DG), an independent factor associated with the development of pre-diabetes, reduces basal GLP-1 secretion in rats.

Objective

This study investigated the effects of 3DG on GLP-1 secretion and SGLT1 pathway under low-glucose conditions in STC-1 cells.

Methods

STC-1 cells were incubated with phloridzin or 3DG at 5.6 mM glucose. SGLT1 expression (by western blotting), GLP-1 and cyclic adenosine monophosphate (cAMP) levels (by ELISA), and intracellular Ca²⁺ concentration (by Fluo-3/AM) were measured.

Results

Phloridzin inhibited GLP-1 secretion. SGLT1 protein expression in STC-1 cells cultured in 5.6 mM glucose is higher than that in 25 mM glucose. Exposure to 3DG for 6 h reduced GLP-1 secretion, SGLT1 protein expression, and intracellular concentrations of cAMP and Ca²⁺.

Conclusions

3DG reduces low glucose-induced GLP-1 secretion in part through reduction of SGLT1 expression.

Keywords:

• 3-Deoxyglucosone
• GLP-1 secretion
• sodium glucose co-transporter 1
• STC-1 cells
• low glucose

Disclosure statement

The authors report no conflicts of interest.

Additional information

Funding

This work was supported by grants from the Suzhou Youth Science and Education Project (KJXW2017043), Suzhou Science and Technology Department (SYSD2016134, SYSD2017191), Suzhou TCM Hospital Affiliated to Nanjing University of Chinese Medicine (YQN2016006), and Suzhou Introduction Program for Clinical Medical Expert Team (SZYJTD201718).