Premium
MyD88 expression in the rat dental follicle: implications for osteoclastogenesis and tooth eruption
Author(s) -
Liu Dawen,
Yao Shaomian,
Wise Gary E.
Publication year - 2010
Publication title -
european journal of oral sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.802
H-Index - 93
eISSN - 1600-0722
pISSN - 0909-8836
DOI - 10.1111/j.1600-0722.2010.00751.x
Subject(s) - rankl , dental follicle , osteoprotegerin , gene knockdown , chemistry , tooth eruption , receptor , medicine , chemokine , small interfering rna , activator (genetics) , endocrinology , microbiology and biotechnology , biology , molar , dentistry , apoptosis , gene , rna , biochemistry , stem cell
Liu D, Yao S, Wise GE. MyD88 expression in the rat dental follicle: implications for osteoclastogenesis and tooth eruption. Eur J Oral Sci 2010; 118: 333–341. © 2010 The Authors. Journal compilation © 2010 Eur J Oral Sci Myeloid differentiation factor 88 (MyD88) is a key adaptor molecule in the interleukin (IL)‐1 and IL‐18 toll‐like receptor signaling pathways. Because MyD88 is present in dental follicle (DF) cells in vitro , the purpose of this study was to determine its chronological expression in vivo , as well as its possible role in osteoclastogenesis and tooth eruption. An oligo DNA microarray was used to determine expression of the Myd88 gene in vivo in the DFs from the first mandibular molars of postnatal rats from days 1 to 11. The results showed that MyD88 was expressed maximally on day 3. Using small interfering RNA (siRNA) to knock down MyD88 expression in the DF cells also reduced the expression of the nuclear factor‐kappa B‐1 ( NFKB1 ) and monocyte chemoattractant protein 1 ( MCP‐1 ) genes. Interleukin‐1α up‐regulated the expression of NFKB1 , MCP‐1 , and receptor activator of nuclear factor kappa B ligand ( RANKL ), but knockdown of MyD88 nullified this IL‐1α effect. Conditioned medium from DF cells with MyD88 knocked down had reduced chemotactic activity for mononuclear cells and reduced osteoclastogenesis, as opposed to controls. In conclusion, the maximal expression of MyD88 in the DF of postnatal day 3 rats may contribute to the major burst of osteoclastogenesis needed for eruption by up‐regulating MCP‐1 and RANKL expression.