[The role of myosin light chain kinase in intestinal epithelial barrier dysfunction due to hypoxia].
OBJECTIVE
To study the role of myosin light chain kinase (MLCK) in intestinal epithelial barrier dysfunction after hypoxia.


METHODS
The Caco-2 monolayers developed with Transwell inserts were exposed to hypoxia for 0 h (NC group), 2, 6, 8, 12 and 24 h (H group), and 6 h hypoxic specimens were treated with 100 mol/L ML-9 (T group). The transepithelial electrical resistance (TER) of monolayers was measured with an ohmmeter. The tight junction protein ZO-1 of monolayers was analyzed by immunofluorescence assay. The protein expressions of phosphorylated myosin light chain (p-MLC) and MLCK were detected by Western blotting.


RESULTS
The TER of monolayers in H group at 6, 8, 12 and 24 h was 422 +/- 17, 427 +/- 27, 403 +/- 40 and 426 +/- 22 ohms respectively, which was significantly lower than that of NC group (451 +/- 27 ohms, P < 0.05). The TER of monolayers in T group was 558 +/- 110 ohms, which was significantly higher than that in H group at each time point ( P < 0.01). The ZO-1 of monolayers in H group at 6 h was irregular in arrangement, with interruptions and rugae, and sawtooth. These abnormalities were ameliorated in T group (regular in arrangement, with little or without ruga and sawtooth). The protein expressions of p-MLC and MLCK in H group at each time point were higher than those in NC group.


CONCLUSIONS
Intestinal epithelial barrier dysfunction after hypoxia can be mediated by MLCK.
Wang
Pei
P
Institute of Burn Research, Southwest Hospital, State Key Laboratory of Trauma, Burns and Combined Injury, the Third Military Medical University, Chongqing 400038, China.
Chen
Chuan-li
CL
Li
Mu
M
Wang
Feng-jun
FJ
D018938:Caco-2 Cells; D004848:Epithelium / Q000378:metabolism / Q000503:physiopathology*; D006801:Humans; D000860:Hypoxia / Q000378:metabolism / Q000503:physiopathology*; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000378:metabolism / Q000503:physiopathology; D007422:Intestines / Q000166:cytology / Q000503:physiopathology*; D018994:Myosin Light Chains / Q000378:metabolism*; D009219:Myosin-Light-Chain Kinase / Q000378:metabolism
D018994:Myosin Light Chains; D009219:Myosin-Light-Chain Kinase