Myosin light chain kinase is involved in lipopolysaccharide-induced disruption of colonic epithelial barrier and bacterial translocation in rats.
Sepsis is associated with bacterial translocation (BT) and changes in colonic paracellular permeability (CPP), but the link between these effects is unknown. The present study aimed to identify whether changes in CPP after lipopolysaccharide (LPS) administration triggers BT, colonic inflammation, visceral pain, and sickness behavior and to evaluate the role of myosin light chain kinase (MLCK) in colonocyte cytoskeleton contraction. Rats received the MLCK inhibitor ML-7 alone or combined with LPS. CPP was measured for 6 hours after administration. Visceral pain, food intake, BT, electron microscopy of tight junctions of colonocytes, cytokine levels, and Western blotting of phosphorylated MLC from colonic mucosa were assessed in a time range of 0 to 3 hours after treatment. Sepsis increased CPP at 0 to 6 hours after LPS and associated with tight junction morphological changes, increased MLC phosphorylation, and mucosal release of proinflammatory cytokines. Massive BT, visceral hyperalgesia, and reduced food intake were also observed. Addition of ML-7 prevented all LPS-induced effects, except for changes in food intake. In conclusion, LPS-mediated effects on CPP include gut inflammation, BT, and visceral hyperalgesia. Inhibition of MLCK-dependent colonocyte cytoskeleton contraction by ML-7 prevents the LPS-induced alterations of CPP and its subsequent effects.
Moriez
Raphaël
R
Institut National de la Recherche Agronomique, Neuro-Gastroenterology and Nutrition Unit, 180 Chemin de Tournefeuille, BP.3, 31931 Toulouse Cedex 9, France.
Salvador-Cartier
Christel
C
Theodorou
Vassilia
V
Fioramonti
Jean
J
Eutamene
Helene
H
Bueno
Lionel
L
D000818:Animals; D001381:Azepines / Q000494:pharmacology; D018988:Bacterial Translocation / Q000187:drug effects*; D015153:Blotting, Western; D002463:Cell Membrane Permeability / Q000187:drug effects; D003106:Colon / Q000166:cytology / Q000187:drug effects* / Q000648:ultrastructure; D003967:Diarrhea / Q000139:chemically induced; D004435:Eating / Q000187:drug effects; D004576:Electromyography; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007249:Inflammation / Q000209:etiology / Q000473:pathology; D007274:Injections, Intraperitoneal; D007371:Interferon-gamma / Q000032:analysis / Q000378:metabolism; D007375:Interleukin-1 / Q000032:analysis / Q000378:metabolism; D015850:Interleukin-6 / Q000032:analysis / Q000378:metabolism; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology / Q000648:ultrastructure; D007700:Kinetics; D008070:Lipopolysaccharides / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000502:physiology; D009219:Myosin-Light-Chain Kinase / Q000378:metabolism*; D009281:Naphthalenes / Q000494:pharmacology; D010147:Pain Measurement; D010766:Phosphorylation; D011506:Proteins / Q000032:analysis / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D019108:Tight Junctions / Q000187:drug effects* / Q000648:ultrastructure; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis / Q000378:metabolism
D001381:Azepines; D004791:Enzyme Inhibitors; D007375:Interleukin-1; D015850:Interleukin-6; D008070:Lipopolysaccharides; D009281:Naphthalenes; D011506:Proteins; D014409:Tumor Necrosis Factor-alpha; C070571:ML 7; D007371:Interferon-gamma; D009219:Myosin-Light-Chain Kinase