title: Porphyromonas gingivalis Differentially Modulates Cell Death Profile in Ox-LDL and TNF-α Pre-Treated Endothelial Cells.
abstract: Clinical studies demonstrated a potential link between atherosclerosis and periodontitis. Porphyromonas gingivalis (Pg), one of the main periodontal pathogen, has been associated to atheromatous plaque worsening. However, synergism between infection and other endothelial stressors such as oxidized-LDL or TNF-α especially on endothelial cell (EC) death has not been investigated. This study aims to assess the role of Pg on EC death in an inflammatory context and to determine potential molecular pathways involved.
  
  
  
  Human umbilical vein ECs (HUVECs) were infected with Pg (MOI 100) or stimulated by its lipopolysaccharide (Pg-LPS) (1μg/ml) for 24 to 48 hours. Cell viability was measured with AlamarBlue test, type of cell death induced was assessed using Annexin V/propidium iodide staining. mRNA expression regarding caspase-1, -3, -9, Bcl-2, Bax-1 and Apaf-1 has been evaluated with RT-qPCR. Caspases enzymatic activity and concentration of APAF-1 protein were evaluated to confirm mRNA results.
  
  
  
  Pg infection and Pg-LPS stimulation induced EC death. A cumulative effect has been observed in Ox-LDL pre-treated ECs infected or stimulated. This effect was not observed in TNF-α pre-treated cells. Pg infection promotes EC necrosis, however, in infected Ox-LDL pre-treated ECs, apoptosis was promoted. This effect was not observed in TNF-α pre-treated cells highlighting specificity of molecular pathways activated. Regarding mRNA expression, Pg increased expression of pro-apoptotic genes including caspases-1,-3,-9, Bax-1 and decreased expression of anti-apoptotic Bcl-2. In Ox-LDL pre-treated ECs, Pg increased significantly the expression of Apaf-1. These results were confirmed at the protein level.
  
  
  
  This study contributes to demonstrate that Pg and its Pg-LPS could exacerbate Ox-LDL and TNF-α induced endothelial injury through increase of EC death. Interestingly, molecular pathways are differentially modulated by the infection in function of the pre-stimulation.
authors.affiliation: INSERM 1109 « Osteoarticular & Dental Regenerative Nanomedicine », Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France.
authors.forename: Isaac Maximiliano
authors.initials: IM
authors.lastname: Bugueno
authors.affiliation: INSERM 1109 « Osteoarticular & Dental Regenerative Nanomedicine », Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France.
authors.forename: Yacine
authors.initials: Y
authors.lastname: Khelif
authors.affiliation: INSERM 1109 « Osteoarticular & Dental Regenerative Nanomedicine », Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France.|Université de Strasbourg, Faculté de Chirurgie-dentaire, Department of Periodontology, Strasbourg, France.
authors.forename: Narendra
authors.initials: N
authors.lastname: Seelam
authors.affiliation: INSERM 1109 « Osteoarticular & Dental Regenerative Nanomedicine », Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France.|Université de Strasbourg, Faculté de Chirurgie-dentaire, Department of Periodontology, Strasbourg, France.
authors.forename: David-Nicolas
authors.initials: DN
authors.lastname: Morand
authors.affiliation: INSERM 1109 « Osteoarticular & Dental Regenerative Nanomedicine », Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France.|Université de Strasbourg, Faculté de Chirurgie-dentaire, Department of Periodontology, Strasbourg, France.
authors.forename: Henri
authors.initials: H
authors.lastname: Tenenbaum
authors.affiliation: INSERM 1109 « Osteoarticular & Dental Regenerative Nanomedicine », Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France.|Université de Strasbourg, Faculté de Chirurgie-dentaire, Department of Periodontology, Strasbourg, France.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Davideau
authors.affiliation: INSERM 1109 « Osteoarticular & Dental Regenerative Nanomedicine », Fédération de Médecine Translationnelle de Strasbourg (FMTS), Strasbourg, France.|Université de Strasbourg, Faculté de Chirurgie-dentaire, Department of Periodontology, Strasbourg, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Huck
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D053477:Apoptotic Protease-Activating Factor 1 / Q000378:metabolism; D050197:Atherosclerosis / Q000473:pathology*; D016866:Bacteroidaceae Infections / Q000382:microbiology / Q000473:pathology*; D020170:Caspase 1 / Q000378:metabolism; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D061307:Human Umbilical Vein Endothelial Cells / Q000378:metabolism* / Q000382:microbiology; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology; D008077:Lipoproteins, LDL / Q000494:pharmacology*; D010518:Periodontitis / Q000473:pathology*; D016966:Porphyromonas gingivalis / Q000378:metabolism / Q000472:pathogenicity*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D051028:bcl-2-Associated X Protein / Q000378:metabolism
chemical_list: C506592:APAF1 protein, human; D053477:Apoptotic Protease-Activating Factor 1; C494826:BAX protein, human; D008070:Lipopolysaccharides; D008077:Lipoproteins, LDL; D019253:Proto-Oncogene Proteins c-bcl-2; D014409:Tumor Necrosis Factor-alpha; D051028:bcl-2-Associated X Protein; C099252:oxidized low density lipoprotein; D053148:Caspase 3; D053453:Caspase 9; D020170:Caspase 1