Premium
HIGH GLUCOSE‐INDUCED INHIBITION OF 2‐DEOXYGLUCOSE UPTAKE IS MEDIATED BY cAMP, PROTEIN KINASE C, OXIDATIVE STRESS AND MITOGEN‐ACTIVATED PROTEIN KINASES IN MOUSE EMBRYONIC STEM CELLS
Author(s) -
Han Ho Jae,
Heo Jung Sun,
Lee Yun Jung,
Min Jung Jun,
Park Kwang Sung
Publication year - 2006
Publication title -
clinical and experimental pharmacology and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 103
eISSN - 1440-1681
pISSN - 0305-1870
DOI - 10.1111/j.1440-1681.2006.04348.x
Subject(s) - glucose transporter , protein kinase c , glucose uptake , staurosporine , snf3 , protein kinase a , biology , phospholipase c , bisindolylmaleimide , pertussis toxin , kinase , g protein , medicine , endocrinology , biochemistry , insulin , signal transduction
SUMMARY1 Abnormally high glucose levels may play an important role in early embryo development and function. In the present study, we investigated the effect of high glucose on 2‐deoxyglucose (2‐DG) uptake and its related signalling pathway in mouse embryonic stem (ES) cells. 2 2‐Deoxyglucose uptake was maximally inhibited by 25 mmol/L glucose after 24 h treatment. However, 25 mmol/L mannitol and dextran did not affect 2‐DG uptake. Indeed, 25 mmol/L glucose decreased GLUT‐1 mRNA and protein levels. The glucose (25 mmol/L)‐induced inhibition of 2‐DG uptake was blocked by pertussis toxin (a G i ‐protein inhibitor; 2 ng/mL), SQ 22536 (an adenylate cyclase inhibitor; 10 ‐6 mol/L) and the protein kinase (PK) A inhibitor myristoylated PKI amide‐(14–22) (10 ‐6 mol/L). Indeed, 25 mmol/L glucose increased intracellular cAMP content. 3 Furthermore, 25 mmol/L glucose‐induced inhibition of 2‐DG uptake was prevented by 10 ‐4 mol/L neomycin or 10 ‐6 mol/L U 73122 (phospholipase C (PLC) inhibitors) and staurosporine or bisindolylmaleimide I (protein kinase (PK) C inhibitors). At 25 mmol/L, glucose increased translocation of PKC from the cytoplasmic fraction to the membrane fraction. The 25 mmol/L glucose‐induced inhibition of 2‐DG uptake and GLUT‐1 protein levels was blocked by SQ 22536, bisindolylmaleimide I or combined treatment. In addition, 25 mmol/L glucose increased cellular reactive oxygen species and the glucose‐induced inhibition of 2‐DG uptake were blocked by the anti‐oxidants N ‐acetylcysteine (NAC; 10 ‐5 mol/L) or taurine (2 ¥ 10 ‐3 mol/L). 4 Glucose (25 mmol/L) activated p38 mitogen‐activated protein kinase (MAPK) and p44/42 MAPK. Staurosporine (10 ‐6 mol/L), NAC (10 ‐5 mol/L) and PD 98059 (10 ‐7 mol/L) attenuated the phosphorylation of p44/42 MAPK. Both SB 203580 (a p38 MAPK inhibitor; 10 ‐7 mol/L) and PD 98059 (a p44/42 MAPK inhibitor; 10 ‐7 mol/L) blocked 25 mmol/L glucose‐induced inhibition of 2‐DG uptake. 5 In conclusion, high glucose inhibits 2‐DG uptake through cAMP, PLC/PKC, oxidative stress or MAPK in mouse ES cells.