title: Role of SIRT1 in heat stress- and lipopolysaccharide-induced immune and defense gene expression in human dental pulp cells.
abstract: BACKGROUND
  Although bacterial infection and heat stress are common causes of injury in human dental pulp cells (HDPCs), little is known about the potential defense mechanisms mediating their effects. This study examined the role of SIRT1 in mediating heat stress and lipopolysaccharide (LPS)-induced immune and defense gene expression in HDPCs.
  
  
  METHODS
  HDPCs were exposed to heat stress (42°C) for 30 minutes after stimulation with LPS (1 μg/mL) for 48 hours. The expression of defense genes was evaluated by reverse-transcriptase polymerase chain reaction, Western blotting, and enzyme-linked immunosorbent assay.
  
  
  RESULTS
  LPS and heat stress synergistically increased the expression of SIRT1 and immune and defense genes such as interleukin (IL)-8, hemeoxygenase-1 (HO-1), and human β-defensin 2 (hBD-2). Resveratrol enhanced LPS- and heat stress-induced expression of HO-1 and hBD-2 but reduced IL-8 messenger RNA levels. The stimulation of HO-1 and hBD-2 messenger RNA expression by LPS and heat stress was inhibited by sirtinol; SIRT1 small interfering RNA; and inhibitors of p38, ERK, JNK, and nuclear factor κB.
  
  
  CONCLUSIONS
  These results show for the first time that SIRT1 mediates the induction of immune and defense gene expression in HDPCs by LPS and heat stress. SIRT1 may play a pivotal role in host immune defense system in HDPCS.
authors: Department of Maxillofacial Tissue Regeneration, School of Dentistry and Institute of Oral Biology, Kyung Hee University, Seoul, Korea.
authors: Sang-Im
authors: SI
authors: Lee
authors: Kyung-San
authors: KS
authors: Min
authors: Won-Jung
authors: WJ
authors: Bae
authors: Young-Man
authors: YM
authors: Lee
authors: So-Youn
authors: SY
authors: Lee
authors: Eui-Suk
authors: ES
authors: Lee
authors: Eun-Cheol
authors: EC
authors: Kim
mesh_terms: D002460:Cell Line; D003782:Dental Pulp / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D018869:Heat-Shock Response / Q000502:physiology*; D051547:Heme Oxygenase-1 / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis / Q000235:genetics; D008070:Lipopolysaccharides / Q000276:immunology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism; D016966:Porphyromonas gingivalis / Q000737:chemistry; D034622:RNA Interference; D017382:Reactive Oxygen Species / Q000032:analysis; D015398:Signal Transduction; D056564:Sirtuin 1 / Q000502:physiology*; D014162:Transfection; D015854:Up-Regulation; D023083:beta-Defensins / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D016209:Interleukin-8; D008070:Lipopolysaccharides; D016328:NF-kappa B; D017382:Reactive Oxygen Species; D023083:beta-Defensins; D051547:Heme Oxygenase-1; D020928:Mitogen-Activated Protein Kinases; C447939:SIRT1 protein, human; D056564:Sirtuin 1