Inhibition of taurine transport by high concentration of glucose in cultured rat cardiomyocytes.
Cultured rat cardiomyocytes were treated with 10, 20, and 30 mmol/L glucose and 30 mmol/L glucose plus protein kinase C (PKC) inhibitor, Chelerythrine. In the 20 and 30 mmol/L glucose-treated cells, taurine contents reduced by 15% and 27% (P<.05), respectively, taurine transporter (TAUT) mRNA levels reduced by 47% and 64% (P<.05), respectively, and cysteine sulfinate decarboxylase (CSD) mRNA reduced slightly, but not significantly. Time-dependent taurine uptakes reduced in the 10, 20, and 30 mmol/L glucose-treated cells, and time-dependent taurine release reduced in the 30 mmol/L glucose-treated cells. The Vmax of taurine transport decreased by 18%, 30%, and 35% (P<.05) in the 10, 20, and 30 mmol/L glucose-treated cells, respectively, while Km of taurine transport remained unchanged. When PKC inhibitor, Chelerythrine, combined with 30 mmol/L glucose was treated with the cells, the lowered taurine content, taurine uptake, taurine release, and Vmax of taurine transport caused by 30 mmol/L glucose were eliminated. These results demonstrate that high glucose considerably and specifically decreases intracellular taurine content, taurine transport activity, and TAUT mRNA, possibly through PKC-mediated transcriptional and posttranslational pathways.
Shi
Yan Rong
YR
Institute of Cardiovascular Research, the First Hospital, Peking University, Beijing, China.
Gao
Lin
L
Wang
Shu Heng
SH
Bu
Ding Fang
DF
Zhang
Bao Hong
BH
Jiang
Hong Fen
HF
Pang
Yong Zheng
YZ
Tang
Chao Shu
CS
D000470:Alkaloids; D000818:Animals; D053119:Benzophenanthridines; D001692:Biological Transport / Q000187:drug effects; D002262:Carboxy-Lyases / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology*; D007700:Kinetics; D008562:Membrane Glycoproteins / Q000235:genetics; D026901:Membrane Transport Proteins; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism*; D010617:Phenanthridines / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013654:Taurine / Q000378:metabolism*; D000099247:Taurine Transporters
D000470:Alkaloids; D053119:Benzophenanthridines; D002262:Carboxy-Lyases; D002352:Carrier Proteins; D004791:Enzyme Inhibitors; D005947:Glucose; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D010617:Phenanthridines; D011493:Protein Kinase C; D012333:RNA, Messenger; D013654:Taurine; D000099247:Taurine Transporters; C016299:chelerythrine; C019972:sulfoalanine decarboxylase