Fig. 4: TXNIP overexpression inhibits metformin-induced upregulation of GLUT1 expression and glucose uptake in intestinal cell lines. | Experimental & Molecular Medicine

Fig. 4: TXNIP overexpression inhibits metformin-induced upregulation of GLUT1 expression and glucose uptake in intestinal cell lines.

From: Novel mechanism whereby metformin improves glucose homeostasis: TXNIP–GLUT1 axis modulation enhances intestinal glucotonic effects

Fig. 4

a The expression of GLUT1 and TXNIP in vehicle- or metformin-treated IEC6 cells expressing EGFP or human TXNIP. b Membrane GLUT1 and TXNIP in vehicle- or metformin-treated EGFP or human TXNIP-overexpressing IEC6 cells. The metformin-induced increase in GLUT1 expression was blunted in TXNIP-overexpressing cells. Expression levels were normalized to ATP1A1. c Representative fluorescence-activated cell sorting (FACS) plots analyzing the effect of TXNIP overexpression on metformin-induced GLUT1 activation, using Alexa 647. The left graphs indicate the geometric mean fluorescence intensity, and the right graphs indicate the percentage of active GLUT1 in FACS plots. d Glucose uptake decreased in metformin-treated TXNIP-overexpressing IEC6 cells compared with metformin-treated EGFP-overexpressing IEC6 cells. Glucose uptake was measured by detecting 2-deoxyglucose-6-phosphate (2DG6P). 2DG6P was normalized with MTS. All data are presented as the mean ± s.e.m. Data in a, c and d were analyzed using two-tailed Student’s t-tests; *P < 0.05, **P < 0.01, ***P < 0.001. NS, nonsignificant.

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