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Acyl Homoserine Lactones Induce Early Response in the Airway
Author(s) -
Sbarbati Andrea,
Tizzano Marco,
Merigo Flavia,
Benati Donatella,
Nicolato Elena,
Boschi Federico,
Cecchini Maria Paola,
Scambi Ilaria,
Osculati Francesco
Publication year - 2009
Publication title -
the anatomical record: advances in integrative anatomy and evolutionary biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.678
H-Index - 62
eISSN - 1932-8494
pISSN - 1932-8486
DOI - 10.1002/ar.20866
Subject(s) - secretion , quorum sensing , extracellular , in vivo , microbiology and biotechnology , biology , homoserine , innate immune system , respiratory epithelium , epithelium , chemistry , immune system , biochemistry , immunology , gene , virulence , genetics
Acyl homoserine lactones (AHLs) are intercellular signaling molecules used in quorum sensing by Gram‐negative bacteria. We studied the early effects on the rat airway of in vivo intratracheal administration of AHLs (i.e., P. aeruginosa and B. cepacia ) to test the hypothesis that AHLs also act on the airway cells, modifying secretory mechanisms which are important in mucosal defense. One hour after treatment, N ‐butyryl‐homoserine lactone (C4‐HL) had caused dilated extracellular spaces, loss of cilia, reduction of secretory material, and the presence of prenecrotic elements in the epithelium, while N ‐octanoyl‐homoserine lactone (C8‐HL) caused a mild lesion in the epithelium. After treatment with either C4‐ or C8‐HL, reduced immunoreactivity was found using CC10 antibody. At ultrastructural examination, dilatation of the mitochondria was evident in ciliate and secretory cells, while solitary chemosensory cells appeared better preserved, showing aspects of nucleocytoplasmic activation. Using microarray analysis, we found down‐regulation of early gene Fos and Egr1 in all AHL‐treated specimens. In vivo pharmacological magnetic resonance imaging after C4‐ or C8‐HL treatment showed a slight increase in tracheal secretion at a first evaluation 5 min after administration, with no increase in the following minutes. In conclusion, AHLs induce an early mucosal response, and the chondriomas of ciliate and secretory cells are the main cytological target of AHL action. Our results show that AHL action is not limited to activation of conspecific bacteria, but also modifies innate airway defense mechanisms. Anat Rec, 292:439–448, 2009. © 2009 Wiley‐Liss, Inc.