Inhibition of monocyte adhesion on brain-derived endothelial cells by NF-kappaB decoy/polyethylenimine complexes.
BACKGROUND
The nuclear factor (NF)-kappaB plays a key role in inflammatory reactions of the endothelium by controlling the expression of surface-adhesion molecules and other inflammatory mediators, which facilitate the attachment of monocytes and lymphocytes to the endothelial surface. We investigated the inhibition of monocyte adhesion by NF-kappaB transcription factor decoys complexed with polyethylenimines (PEIs) of different molecular weights and structures (800, 25, and 2.7 kDa PEI).


METHODS
Formation, size and stability of the PEI/decoy complexes were investigated by polyacrylamide gel electrophoresis and photon correlation spectroscopy. The efficiency of the complexes was studied in a cell adhesion assay using the murine brain-derived endothelial cell line bEnd5, activated with lipopolysaccharide as inflammatory model. U-937 monocytes were fluorescently labeled with BCECF-AM to permit quantitative measurement of adhesion. Expression of endothelial cell adhesion molecules was determined at the mRNA level by RT-PCR and at the protein level by ELISA.


RESULTS
Depending on the N/P ratio, decoys formed complexes of <200 nm in size with all PEIs, which were stable against degradation by nucleases and dissociation by albumin. Treatment of bEnd5 and U-937 cells with NF-kappaB decoys complexed with 25 and 2.7 kDa PEI reduced the number of adherent U-937 cells and decreased the levels of ICAM-1 and VCAM-1 mRNA and protein. The effects were specific, time-dependent and increased with higher N/P ratios of complexes and lower cytotoxicity of polymers. In contrast, the efficiency of the 800 kDa PEI was much lower compared to the other polymers.


CONCLUSIONS
Complexes of NF-kappaB decoy and PEIs effectively inhibited the adherence of monocytes on endothelial cells, which could be a promising strategy for the treatment of inflammatory diseases.
Fischer
Dagmar
D
Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, 1300 Coulter Dr., Amarillo, TX 79106, USA. fischerd@staff.uni-marburg.de
Bhattacharya
Raktima
R
Osburg
Berit
B
Bickel
Ulrich
U
D000818:Animals; D001921:Brain / Q000166:cytology*; D002448:Cell Adhesion / Q000187:drug effects; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism; D002470:Cell Survival; D002478:Cells, Cultured; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics; D042783:Endothelial Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D051379:Mice; D009000:Monocytes / Q000166:cytology* / Q000187:drug effects* / Q000378:metabolism; D009838:Oligodeoxyribonucleotides / Q000737:chemistry / Q000494:pharmacology*; D011094:Polyethyleneimine / Q000737:chemistry / Q000494:pharmacology*; D020298:U937 Cells
D015815:Cell Adhesion Molecules; C468119:NF-kappaB decoy; D009838:Oligodeoxyribonucleotides; D011094:Polyethyleneimine