title: [The effect of rat dental papilla cells on macrophage secretion of cytokines though paracrine mechanism].
abstract: OBJECTIVE
  To investigate the immunomodulatory effects of rat dental papilla cells (RDPCs) on lipopolysaccharide(LPS)-induced macrophages.
  
  
  METHODS
  Dental papilla tissues from SD rats were isolated and cultured. Cells were passaged and purified using different digesting method. After osteogenic differentiation of rat dental papilla cells, mineralized nodules were assessed by Alizarin red S staining. Oil red-O staining was used to observe the lipid after adipogenic differentiation of rat dental papilla cells. The effect of rat dental papilla cells conditioned medium (RDPC-CM) on macrophages proliferation was assessed using a cell counting kit-8 (CCK-8). LPS-stimulated macrophages were treated with RDPC-CM and the level of IL-1β, TNF-α, IL-6 and nitric oxide (NO) in the supernatants were evaluated by enzyme-linked immunosorbent assay (ELISA) and Greiss reagent. The results were analyzed by using SPSS 13.0 software package.
  
  
  RESULTS
  RDPCs were found around dental papilla piece after 24h of cultures, the cells could be purified using different digesting methods. Aliarin red staining and Oil red-O staining certified the presence of mineralized nodules and lipid in rat dental papilla cells, respectively. CCK-8 assay results showed that the proliferation of macrophages was not affected by RDPC-CM. ELISA and Griess reagent assay revealed a significantly decreased level of TNF-α in the supernatants of LPS-stimulated macrophages upon RDPC-CM treatment compared with the control, but not the levels of IL-6, IL-1β and NO.
  
  
  CONCLUSIONS
  RDPC-CM inhibited the expression of TNF-α in LPS-treated macrophages, indicating that rat dental papilla cells may play a role in immunomodulatory effects.
authors.affiliation: Department of Endodontics and Conservative Dentistry, Guanghua School and Hospital of Stomatology and Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University. Guangzhou 510021, Guangdong Province, China. E-mail:107035768@qq.com.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Hong
authors.initials: H
authors.lastname: Hong
authors.forename: Yan Qing
authors.initials: YQ
authors.lastname: Zhang
authors.forename: Xi
authors.initials: X
authors.lastname: Wei
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D016207:Cytokines; D003771:Dental Papilla; D004797:Enzyme-Linked Immunosorbent Assay; D053583:Interleukin-1beta; D015850:Interleukin-6; D008070:Lipopolysaccharides; D008264:Macrophages; D009569:Nitric Oxide; D010012:Osteogenesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D014409:Tumor Necrosis Factor-alpha
chemical_list: D016207:Cytokines; D053583:Interleukin-1beta; D015850:Interleukin-6; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide