Induction of inducible nitric oxide synthase and apoptosis by LPS and TNF-alpha in nasal microvascular endothelial cells.
CONCLUSIONS
This study demonstrates that the co-administration of lipopolysaccharide (LPS) and tumor necrosis factor-alpha (TNF-alpha) (LPS/TNF-alpha) can induce the expression of inducible nitric oxide synthase (iNOS), which results in the generation of apoptosis in cultured human nasal microvascular endothelial cells (HNMECs). Since LPS and TNF-alpha have been suggested to play an important role in the pathophysiology of nasal disease, we conclude that microvascular leakage may therefore contribute to the inflammatory process in nasal disease, such as allergic rhinitis and asthma.


METHODS
The HNMECs were obtained from the inferior turbinate and subsequently cultured. The expression of iNOS induced by both the LPS and TNF-alpha was investigated by fluorescent immunohistochemistry, using confocal laser microscopy. The DNA-binding dye, Hoechist 33342, was also used to analyze the apoptosis in the HNMECs.


RESULTS
The fluorescent immunohistochemistory study demonstrated that LPS and TNF-alpha induced the expression of iNOS in HNMECs. LPS/TNF-alpha remarkably augmented the expression of iNOS in HNMECs in comparison to stimulation by either LPS or TNF-alpha alone. LPS/TNF-alpha also induced apoptosis in HNMECs. 1400W, a highly selective inhibitor of iNOS, inhibited both the expression of iNOS and the apoptosis induced by LPS/TNF-alpha.
Arai
Shoji
S
Department of Otolaryngology, Kansai Medical University, Moriguchi, Osaka, Japan.
Harada
Narinobu
N
Kubo
Nobuo
N
Shen
Jing
J
Nakamura
Akihiko
A
Ikeda
Hiroki
H
Tsuji
Hiroyuki
H
Yamashita
Toshio
T
D017209:Apoptosis / Q000187:drug effects*; D002199:Capillary Permeability / Q000187:drug effects; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000187:drug effects*; D004790:Enzyme Induction / Q000187:drug effects; D004926:Escherichia coli; D006801:Humans; D066298:In Vitro Techniques; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008833:Microcirculation / Q000187:drug effects; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D009297:Nasal Mucosa / Q000098:blood supply*; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism*; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D008070:Lipopolysaccharides; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D014409:Tumor Necrosis Factor-alpha; D052247:Nitric Oxide Synthase Type II