Down-regulation of aquaporin3 expression by lipopolysaccharide via p38/c-Jun N-terminal kinase signalling pathway in HT-29 human colon epithelial cells.
OBJECTIVE
To investigate the influence of lipopolysaccharide (LPS) through the p38/c-Jun N-terminal kinase (JNK) signalling pathway on aquaporin 3 (AQP3) expression in HT-29 human colon epithelial cells.


METHODS
HT-29 cells were treated with LPS, and then the membrane localisation of AQP3 was examined by immunofluorescence staining. The mRNA and protein expression of AQP3 with LPS exposure was measured by real-time reverse transcription-PCR and Western blot, respectively. Activation of p38 and JNK was evaluated by detection of phosphorylation of p38 and JNK using Western blot assay. AQP3 protein expression was determined by Western blot in cells after treatment with SB203580, a selective p38 MAPK inhibitor, or SP600125, a selective JNK inhibitor.


RESULTS
In HT-29 cells, the transcription and protein expression of AQP3 were decreased by LPS in a dose- and time-dependent manner, the expression of AQP3 was significantly decreased with the increased concentration of LPS, and at a dose of 100 μg/mL LPS, AQP3 mRNA and protein levels were decreased by a maximum (P < 0.05) of 1.51-fold and 1.49-fold, respectively. When cells were treated with 100 μg/mL LPS for 0, 3, 6, 12, and 24 h, the AQP3 mRNA level was significantly decreased at an early time point of 3 h, and reached about 10% of the control level at 24 h post-treatment (P < 0.05). Down-regulation of AQP3 expression was significantly inhibited by the p38 inhibitor (SB203580) and JNK inhibitor (SP600125).


CONCLUSIONS
p38 and JNK may be promising targets for the preservation of AQP3 expression and may be beneficial to the clinical management of diarrhoea.
Feng-Xia Li, Li-Zhen Huang, Chuan Dong, Hong-Juan Wu, Shao-Min Shuang, School of Chemistry and Chemical Engineering, Research Center of Environmental Science and Engineering, Shanxi University, Taiyuan 030006, Shanxi Province, China.
Feng-Xia
FX
Li
Feng-Xia Li, Li-Zhen Huang, Chuan Dong, Hong-Juan Wu, Shao-Min Shuang, School of Chemistry and Chemical Engineering, Research Center of Environmental Science and Engineering, Shanxi University, Taiyuan 030006, Shanxi Province, China.
Li-Zhen
LZ
Huang
Feng-Xia Li, Li-Zhen Huang, Chuan Dong, Hong-Juan Wu, Shao-Min Shuang, School of Chemistry and Chemical Engineering, Research Center of Environmental Science and Engineering, Shanxi University, Taiyuan 030006, Shanxi Province, China.
Chuan
C
Dong
Feng-Xia Li, Li-Zhen Huang, Chuan Dong, Hong-Juan Wu, Shao-Min Shuang, School of Chemistry and Chemical Engineering, Research Center of Environmental Science and Engineering, Shanxi University, Taiyuan 030006, Shanxi Province, China.
Jun-Ping
JP
Wang
Feng-Xia Li, Li-Zhen Huang, Chuan Dong, Hong-Juan Wu, Shao-Min Shuang, School of Chemistry and Chemical Engineering, Research Center of Environmental Science and Engineering, Shanxi University, Taiyuan 030006, Shanxi Province, China.
Hong-Juan
HJ
Wu
Feng-Xia Li, Li-Zhen Huang, Chuan Dong, Hong-Juan Wu, Shao-Min Shuang, School of Chemistry and Chemical Engineering, Research Center of Environmental Science and Engineering, Shanxi University, Taiyuan 030006, Shanxi Province, China.
Shao-Min
SM
Shuang
D000930:Antidiarrheals / Q000494:pharmacology; D051400:Aquaporin 3 / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D003106:Colon / Q000187:drug effects* / Q000201:enzymology; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D004789:Enzyme Activation; D004847:Epithelial Cells / Q000187:drug effects* / Q000201:enzymology; D019073:HT29 Cells; D006801:Humans; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000201:enzymology; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*
C496027:AQP3 protein, human; D000930:Antidiarrheals; D008070:Lipopolysaccharides; D047428:Protein Kinase Inhibitors; D012333:RNA, Messenger; D051400:Aquaporin 3; D048031:JNK Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases
Aquaporin3; Colon; HT-29 cells; Lipopolysaccharide; MAPK signalling pathway