Neutrophil transepithelial migration: evidence for sequential, contact-dependent signaling events and enhanced paracellular permeability independent of transjunctional migration.
Active migration of polymorphonuclear leukocytes (PMN) through the intestinal crypt epithelium is a hallmark of inflammatory bowel disease and correlates with patient symptoms. Previous in vitro studies have shown that PMN transepithelial migration results in increased epithelial permeability. In this study, we modeled PMN transepithelial migration across T84 monolayers and demonstrated that enhanced paracellular permeability to small solutes occurred in the absence of transepithelial migration but required both PMN contact with the epithelial cell basolateral membrane and a transepithelial chemotactic gradient. Early events that occurred before PMN entering the paracellular space included increased permeability to small solutes (<500 Da), enhanced phosphorylation of regulatory myosin L chain, and other as yet undefined proteins at the level of the tight junction. No redistribution or loss of tight junction proteins was detected in these monolayers. Late events, occurring during actual PMN transepithelial migration, included redistribution of epithelial serine-phosphorylated proteins from the cytoplasm to the nucleus in cells adjacent to migrating PMN. Changes in phosphorylation of multiple proteins were observed in whole cell lysates prepared from PMN-stimulated epithelial cells. We propose that regulation of PMN transepithelial migration is mediated, in part, by sequential signaling events between migrating PMN and the epithelium.
Edens
Heather A
HA
Division of Gastrointestinal Pathology, Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA 30322, USA. hedens@emory.edu
Levi
Boaz P
BP
Jaye
David L
DL
Walsh
Shaun
S
Reaves
Titus A
TA
Turner
Jerrold R
JR
Nusrat
Asma
A
Parkos
Charles A
CA
D000205:Actomyosin / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology; D002450:Cell Communication / Q000502:physiology*; D002460:Cell Line; D002463:Cell Membrane Permeability / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D015194:Diffusion Chambers, Culture; D017097:Electric Impedance; D006801:Humans; D007365:Intercellular Junctions / Q000502:physiology*; D007413:Intestinal Mucosa / Q000166:cytology* / Q000378:metabolism / Q000502:physiology*; D018994:Myosin Light Chains / Q000378:metabolism; D009504:Neutrophils / Q000166:cytology* / Q000502:physiology*; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism; D021381:Protein Transport / Q000502:physiology; D011506:Proteins / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D012995:Solubility
D018994:Myosin Light Chains; D011506:Proteins; D010768:Phosphoserine; D000205:Actomyosin