title: Porphyromonas gingivalis and its lipopolysaccharide differentially regulate the expression of cathepsin B in endothelial cells.
abstract: Porphyromonas gingivalis infection and cathepsins protease upregulation are independently implicated in atherosclerosis worsening. In this study, we evaluated the effects of P. gingivalis infection and P. gingivalis -purified lipopolysaccharide (Pg-LPS) stimulation on the expression of cathepsin B (CATB) in endothelial cells (ECs). Analysis of the enzymatic activity and expression of CATB were investigated at the messenger RNA, protein and protein-phosphorylation levels. Effects of Toll-like receptors 2 and 4 blocking on CATB activity were also analysed. Our results showed that P. gingivalis and Pg-LPS significantly increased the activity of CATB but with different kinetics. The peak of CATB activity was observed 3 h after P. gingivalis infection but it appeared 48 h after Pg-LPS stimulation. The increase of CATB activity was related to its rapid tyrosine-dephosphorylation during P. gingivalis infection, whereas the levels of CATB messenger RNAs and proteins did not vary after P. gingivalis infection or Pg-LPS stimulation. Inhibition of Toll-like-receptors 2 and 4 differentially decreased P. gingivalis and Pg-LPS CATB activations. These results showed for the first time that P. gingivalis infection rapidly affects ECs and modulates CATB activity, whereas Pg-LPS effects appear to be delayed. This study suggests that direct infection of ECs by P. gingivalis may worsen atherosclerotic plaque formation via activation of the CATB pathway.
authors.affiliation: Department of Periodontology, Dental Faculty, Strasbourg, France. huck.olivier@gmail.com
authors.forename: O
authors.initials: O
authors.lastname: Huck
authors.forename: R
authors.initials: R
authors.lastname: Elkaim
authors.forename: J L
authors.initials: JL
authors.lastname: Davideau
authors.forename: H
authors.initials: H
authors.lastname: Tenenbaum
mesh_terms: D016866:Bacteroidaceae Infections / Q000201:enzymology; D002401:Cathepsin B / Q000187:drug effects*; D018929:Cell Culture Techniques; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology* / Q000382:microbiology; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D015151:Immunoblotting; D008070:Lipopolysaccharides / Q000494:pharmacology*; D010766:Phosphorylation; D016966:Porphyromonas gingivalis / Q000502:physiology*; D011505:Protein-Tyrosine Kinases / Q000187:drug effects; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D051195:Toll-Like Receptor 2 / Q000037:antagonists & inhibitors; D051197:Toll-Like Receptor 4 / Q000037:antagonists & inhibitors; D014471:Umbilical Veins / Q000166:cytology
chemical_list: D008070:Lipopolysaccharides; C495342:TLR2 protein, human; C495345:TLR4 protein, human; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D011505:Protein-Tyrosine Kinases; C533912:CTSB protein, human; D002401:Cathepsin B