title: Porphyromonas gingivalis Lipopolysaccharide Stimulation of Vascular Smooth Muscle Cells Activates Proliferation and Calcification.
abstract: Porphyromonas gingivalis (Pg) is a major etiologic agent of periodontitis, whose virulence has been attributed to different factors, including lipopolysaccharide (LPS). Vascular ectopic calcification as a well-known major risk factor for adverse cardiovascular diseases is a highly prevalent vascular pathophenotype, and vascular smooth muscle cells (VSMCs) play an important role in mediating vascular calcification. It was hypothesized that Pg-LPS may stimulate vascular calcification through a direct effect on VSMC function. To test this hypothesis, the effect of Pg-LPS on VSMC calcification was determined.
  
  
  
  Primary cultures of VSMCs were obtained and identified by immunochemistry in vitro. The proliferation and alkaline phosphatase (ALP) activity of VSMCs were measured using a cell counting kit and an ALP activity test. Mineral deposition was examined using alizarin red staining. Gene (e.g. ALP, core binding factor α1 [Cbfα1], bone sialoprotein [BSP], and osteopontin [OPN]) expression levels altered by Pg-LPS were determined by reverse transcription-polymerase chain reaction array.
  
  
  
  Pg-LPS could increase the proliferation of VSMCs at different times and enhance ALP activity of VSMCs after 1 day. Alizarin red staining and quantification showed that, with Pg-LPS treatment, VSMCs displayed more obvious calcification nodules. When stimulated with Pg-LPS, the expression of specific osteogenic genes (e.g., ALP, Cbfα1, BSP, and OPN) was significantly promoted in the presence or absence of mineralization-inducing medium, whereas the expression of the OPN gene was inhibited in the mineralization induction group at day 7.
  
  
  
  Pg-LPS can stimulate VSMC calcification, which results in vascular calcification, further proving the precise relationship between periodontitis and vascular calcification.
authors.affiliation: Department of Stomatology, Affiliated Hospital of Qingdao University, Qingdao, Shandong, People's Republic of China.|Department of Stomatology, Qingdao Municipal Hospital, Qingdao, Shandong, People's Republic of China.
authors.forename: Guirong
authors.initials: G
authors.lastname: Liu
authors.affiliation: Department of Stomatology, Affiliated Hospital of Qingdao University, Qingdao, Shandong, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Deng
authors.affiliation: Department of Stomatology, Qingdao Municipal Hospital, Qingdao, Shandong, People's Republic of China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Stomatology, Affiliated Hospital of Qingdao University, Qingdao, Shandong, People's Republic of China.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Song
authors.affiliation: Department of Stomatology, Qingdao Municipal Hospital, Qingdao, Shandong, People's Republic of China.
authors.forename: Shulan
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Stomatology, Affiliated Hospital of Qingdao University, Qingdao, Shandong, People's Republic of China.
authors.forename: Xiuxiu
authors.initials: X
authors.lastname: Lou
authors.affiliation: Department of Stomatology, Affiliated Hospital of Qingdao University, Qingdao, Shandong, People's Republic of China.
authors.forename: Pengmei
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Department of Stomatology, Affiliated Hospital of Qingdao University, Qingdao, Shandong, People's Republic of China.
authors.forename: Keqing
authors.initials: K
authors.lastname: Pan
mesh_terms: D002114:Calcinosis; D049109:Cell Proliferation; D002478:Cells, Cultured; D006801:Humans; D009131:Muscle, Smooth, Vascular / Q000382:microbiology*; D032389:Myocytes, Smooth Muscle; D016966:Porphyromonas gingivalis / Q000737:chemistry*
keywords: Cell proliferation; Porphyromonas gingivalis; lipopolysaccharide; periodontal diseases; vascular calcification