title: Hyperlipidemia causes changes in inflammatory responses to periodontal pathogen challenge: implications in acute and chronic infections.
abstract: OBJECTIVE
  In this study, the effect of hyperlipidemia on immune responses to periodontal bacterial infections was investigated.
  
  
  METHODS
  Sixty male New Zealand white rabbits were equally assigned to normal diet (ND) and high-fat diet (HFD) for 6 weeks. Every six rabbits with ND or HFD were orally inoculated with live Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis three times a week for 8 weeks. Also every six rabbits with ND or HFD rabbits were injected intravenously with A. actinomycetemcomitans and P. gingivalis LPS. Periodontal disease severity was quantified by macroscopic and radiographical evaluation. Serum cytokines were examined by enzyme-linked immunosorbent assay. In vitro, peripheral mononuclear cells were collected and stimulated with LPS. Quantitative real-time polymerase chain reaction was used to determine the changes in gene expression of macrophages.
  
  
  RESULTS
  In the early stages of infection, HFD rabbits were exposed to oral infection and systemic infection developed a weak inflammatory response to the reduced cytokine expression compared with ND rabbits. However, HFD rabbits exhibited higher inflammatory cytokine expression during long-term infections. Moreover, the pronounced changes in inflammatory cytokine expression elicited a significantly increase in bone loss in HFD rabbits with oral infection. Peripheral macrophages harvested from HFD rabbits and exposed to LPS exhibited reduced levels of pro-inflammatory cytokines compared with those from ND rabbits in vitro.
  
  
  CONCLUSIONS
  These data indicated that hyperlipidemia interfered with immune responses differently. The mechanism is possibly associated with immune paralysis in the acute phase and accumulation of inflammatory mediators in the chronic period.
authors.affiliation: School and Hospital of Stomatology, Fujian Medical University, and Stomatological Key Lab of Fujian College and University, Fuzhou, Fujian 350002, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Chen
authors.affiliation: Department of Stomatology, Fujian Provincial People's Hospital, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350004, China.
authors.forename: Gengbing
authors.initials: G
authors.lastname: Lin
authors.affiliation: School and Hospital of Stomatology, Fujian Medical University, and Stomatological Key Lab of Fujian College and University, Fuzhou, Fujian 350002, China.
authors.forename: Xiaoqing
authors.initials: X
authors.lastname: You
authors.affiliation: School and Hospital of Stomatology, Fujian Medical University, and Stomatological Key Lab of Fujian College and University, Fuzhou, Fujian 350002, China.
authors.forename: Lang
authors.initials: L
authors.lastname: Lei
authors.affiliation: School and Hospital of Stomatology, Fujian Medical University, and Stomatological Key Lab of Fujian College and University, Fuzhou, Fujian 350002, China.
authors.forename: Yanfen
authors.initials: Y
authors.lastname: Li
authors.affiliation: School and Hospital of Stomatology, Fujian Medical University, and Stomatological Key Lab of Fujian College and University, Fuzhou, Fujian 350002, China.
authors.forename: Minkun
authors.initials: M
authors.lastname: Lin
authors.affiliation: School and Hospital of Stomatology, Fujian Medical University, and Stomatological Key Lab of Fujian College and University, Fuzhou, Fujian 350002, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Luo
authors.affiliation: Institute and Hospital of Stomatology, Nanjing University Medical School, Nanjing, Jiangsu 210008, China. Electronic address: fhyan2005@126.com.
authors.forename: Fuhua
authors.initials: F
authors.lastname: Yan
mesh_terms: D016976:Aggregatibacter actinomycetemcomitans / Q000276:immunology; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000276:immunology; D000818:Animals; D002908:Chronic Disease; D016207:Cytokines / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D006949:Hyperlipidemias / Q000276:immunology*; D008264:Macrophages / Q000187:drug effects; D008297:Male; D010510:Periodontal Diseases / Q000276:immunology* / Q000382:microbiology; D016966:Porphyromonas gingivalis / Q000276:immunology; D011817:Rabbits; D011859:Radiography; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D016207:Cytokines
keywords: Aggregatibacter actinomycetemcomitans; Cytokine; Hyperlipidemia; Inflammatory response; Periodontitis; Porphyromonas gingivalis