High glucose condition upregulated Txnip expression level in rat mesangial cells through ROS/MEK/MAPK pathway.
Thioredoxin interacting protein (Txnip) is one of the most abundantly up-regulated genes in response to hyperglycemia. The increased renal expression of Txnip was associated with type IV collagen accumulation in streptozotocin-induced diabetic mice. As the mechanism of action of high glucose is unknown, we undertook the investigation of the signaling pathway on the upregulation of Txnip expression induced by high glucose in rat mesangial cells. Rat mesangial cells were exposed to normal (5.5 mM) or high (25 mM) glucose at different time points. Txnip expression was determined using real-time RT-PCR and western-blotting at transcription and translation level, respectively. Intracellular reactive oxygen species (ROS) was detected by FACS Calibur flow cytometer using fluorescent probe (DCFH-DA).The treatment with high glucose resulted in an increase of Txnip mRNA from 4 h to 12 h and Txnip protein from 12 to 24 h in comparison with normal glucose condition. In addition, N-acetyl-cysteine (NAC) was found to decrease Txnip protein expression under high glucose condition. Furthermore, p38MAPK inhibitor SB203580 suppressed Txnip expression at transcription and protein level significantly to high glucose exposure. These results suggest that high glucose exposure improves Txnip mRNA and protein expression level by ROS/MEK/MAPK signaling pathway.
Department of Biochemistry and Molecular Biology, Harbin Medical University, Harbin, 150081, People's Republic of China.
Shaohong
S
Fang
Yuhong
Y
Jin
Haixia
H
Zheng
Junxia
J
Yan
Yunxia
Y
Cui
Huimei
H
Bi
Huijie
H
Jia
Huishu
H
Zhang
Yi
Y
Wang
Liying
L
Na
Xu
X
Gao
Hongbo
H
Zhou
D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D018797:Cell Cycle Proteins; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D005947:Glucose / Q000494:pharmacology*; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D050527:Mesangial Cells / Q000187:drug effects / Q000201:enzymology*; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013997:Time Factors; D015854:Up-Regulation / Q000187:drug effects*; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D047428:Protein Kinase Inhibitors; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; C493796:TXNIP protein, rat; D048049:Extracellular Signal-Regulated MAP Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D020929:Mitogen-Activated Protein Kinase Kinases; D005947:Glucose; D000111:Acetylcysteine