title: Expression of nucleotide-binding oligomerization domain 2 in normal human dental pulp cells and dental pulp tissues.
abstract: BACKGROUND
  The nucleotide-binding oligomerization domain (NOD) proteins belong to a distinct family of proteins that are implicated in the intracellular recognition of bacterial components. NOD2 appears to be a sensor of bacterial peptidoglycans because it recognizes a minimal motif present in all peptidoglycans. The interaction of NOD2 with downstream signaling molecules ultimately results in the activation of NF-kappaB and production of inflammatory mediators in innate immunity. As such, NOD2 may play an important role in the detection of bacterial pathogens and the initiation of inflammation within the dental pulp. This study was designed to evaluate the expression of NOD2 in normal human dental pulp cells (HDPCs) and human pulp tissues.
  
  
  METHODS
  Human pulp tissue samples were collected from freshly extracted human wisdom teeth, and HDPCs were prepared from the explants of normal human dental pulp tissues. Nested reverse-transcription polymerase chain reaction (Nested RT-PCR) and Western blotting were performed to detect the expression of NOD2 messenger RNA and protein, respectively. Immunohistochemical staining was used to determine the distribution of NOD2 in the pulp tissues.
  
  
  RESULTS
  The NOD2 messenger RNA and protein were present in normal human dental pulp tissues, with most NOD2 protein expression being localized to odontoblasts and some pulp vascular endothelial cells. In contrast, HDPCs only showed a low level of NOD2 protein expression.
  
  
  CONCLUSIONS
  Our results suggest that NOD2 protein expressed in HDPCs and pulp tissues may play an important role in dental immune defense.
authors.affiliation: Department of Operative and Endodontics, Sun Yat-sen College of Medical Sciences, Sun Yat-sen University, Guangzhou, China. linzhm@mail.sysu.edu.cn
authors.forename: Zheng-Mei
authors.initials: ZM
authors.lastname: Lin
authors.forename: Zhi
authors.initials: Z
authors.lastname: Song
authors.forename: Wei
authors.initials: W
authors.lastname: Qin
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.forename: Wen-Jie
authors.initials: WJ
authors.lastname: Li
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Zhu
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
mesh_terms: D000119:Acetylmuramyl-Alanyl-Isoglutamine / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D015153:Blotting, Western; D002478:Cells, Cultured; D002648:Child; D003782:Dental Pulp / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000378:metabolism; D005260:Female; D006801:Humans; D007113:Immunity, Innate / Q000502:physiology; D007150:Immunohistochemistry; D008297:Male; D053473:Nod2 Signaling Adaptor Protein / Q000032:analysis / Q000096:biosynthesis* / Q000276:immunology*; D009804:Odontoblasts / Q000276:immunology / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D055815:Young Adult
chemical_list: C429018:NOD2 protein, human; D053473:Nod2 Signaling Adaptor Protein; D012333:RNA, Messenger; D000119:Acetylmuramyl-Alanyl-Isoglutamine