title: PPARγ affects nitric oxide in human umbilical vein endothelial cells exposed to Porphyromonas gingivalis.
abstract: OBJECTIVE
  Porphyromonas gingivalis induces nitric oxide (NO) synthesis in human umbilical vein endothelial cells (HUVECs). Peroxisome proliferator-activated receptor (PPARγ) has an anti-inflammation function, and its involvement in this NO induction process requires elucidation. Here, we focused on PPARγ expression in HUVECs exposed to P. gingivalis, and investigated its effects on NO synthesis.
  
  
  METHODS
  HUVECs were time-dependently stimulated by P. gingivalis W83 for 0-24h. PPARγ expression was assessed at the mRNA and protein levels, and PPARγ activation was measured using dual-luciferase reporter assays. NO synthesis and NO synthase (NOS) expression in response to P. gingivalis were examined in HUVECs pretreated with representative PPARγ agonist (15-deoxy-Δ12,14-prostaglandin J2 10μM) or antagonist (GW9662 10μM). In addition, NO synthesis and NOS expression in the P. gingivalis infected and control groups were detected.
  
  
  RESULTS
  The PPARγ mRNA level in HUVECs increased after exposure to P. gingivalis for 1h and its protein level increased at 2h. Luciferase-induced PPARγ increased in P. gingivalis-exposed HUVECs. NO synthesis in the infected group at 4h, and in the PPARγ-activated group at 8h, was higher than that in controls. Inducible NOS increased in the infected and PPARγ-activated groups at 4 and 8h. The total endothelial NOS (eNOS) and phospho-eNOS levels were lower in the infected group than controls, but did not change in the PPARγ-activated group.
  
  
  CONCLUSIONS
  Activated PPARγ induces NO generation through the NOS pathway in HUVECs exposed to P. gingivalis.
authors.affiliation: The Second Dental Center, Peking University School and Hospital of Stomatology, Anli Garden B5, Anli Road 66, Chaoyang District, 100101 Beijing, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Li
authors.affiliation: Department of Ultrasound, the 302 Hospital of Chinese PLA, 100 Xisihuanzhonglu, 100039 Beijing, China. Electronic address: zdk002@163.com.
authors.forename: Dakun
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Department of Periodontology, Peking University School and Hospital of Stomatology, 22 Zhongguancun South street, 100081 Beijing, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Wan
authors.affiliation: Department of Periodontology, Peking University School and Hospital of Stomatology, 22 Zhongguancun South street, 100081 Beijing, China.
authors.forename: Jianru
authors.initials: J
authors.lastname: Liu
mesh_terms: D015153:Blotting, Western; D061307:Human Umbilical Vein Endothelial Cells / Q000378:metabolism* / Q000382:microbiology*; D006801:Humans; D009569:Nitric Oxide / Q000096:biosynthesis* / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000096:biosynthesis / Q000378:metabolism; D047495:PPAR gamma / Q000819:agonists / Q000235:genetics / Q000378:metabolism*; D016966:Porphyromonas gingivalis / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D047495:PPAR gamma; D012333:RNA, Messenger; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase
keywords: Endothelial cells; Nitric oxide; Peroxisome proliferator-activated receptor; Porphyromonas gingivalis