| Toll-like receptors and their adaptors are regulated in macrophages after phagocytosis of lipopolysaccharide-coated titanium particles. | |
| | |
MedLine Citation:
|
PMID: 21308757 Owner: NLM Status: Publisher |
Abstract/OtherAbstract:
|
Macrophages phagocytose metallic wear particles and produce mediators, which can induce cellular host response and aseptic implant loosening. Lipopolysaccharide (LPS) on the wear debris can stimulate macrophages via Toll-like receptor 4 (TLR4) and enhance the response. However, the precise functional role and interaction of TLRs and their adaptor molecules is still unclear. Rat bone marrow macrophages were stimulated with titanium particle (Ti) coated by LPS (Ti/LPS+) and LPS-free Ti (Ti/LPS-). mRNA levels of cytokines, TLRs and their adaptor molecules were measured using real time PCR. mRNA levels of TNF-α, IL-1β, and IL-6 increased in Ti/LPS+ than Ti/LPS-. In contrast, mRNA levels of TLR4, TLR5, and TLR9 decreased in Ti/LPS+ compared to Ti/LPS-. mRNA levels of MyD88, IRAK1, IRAK4 decreased gradually, and TRAF6 underwent an initial transient increase, followed by suppression in Ti/LPS+. However, mRNA levels of TLR2 and IRAK2 increased after phagocytosis of Ti/LPS+ than Ti/LPS-. The increased expressions of proinflammatory cytokines found in Ti/LPS+ indicated that their productions cytokines could be enhanced by phagocytosis of LPS-coated particles. Subsequent down-regulation of TLR4, TLR5, TLR9, MyD88, IRAK1, and IRAK4 suggests that self-protective mechanisms to regulate excessive host responses are activated in macrophages. Increase of TLR2 and IRAK2 and a transient increase of TRAF6 in Ti/LPS+ suggest that another possible pathway to modulate TLR-mediated cellular response to prolong inflammatory response in foreign body reaction of aseptic loosening. This down- and/or up-regulation of the potential TLR-mediated responses to LPS-coated particles reflects the proactive behavior of effector cells. © 2011 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res. |
| | |
Authors:
|
Tomoyuki Hirayama; Yasunobu Tamaki; Yuya Takakubo; Kiyoshi Iwazaki; Kan Sasaki; Toshihiko Ogino; Stuart B Goodman; Yrjö T Konttinen; Michiaki Takagi |
Related Documents
:
|
20048047 - Pore formation triggered by legionella spp. is an nlrc4 inflammasome-dependent host cel... 16650977 - Interactions between bacteria and eukaryotes via small molecules. 20370627 - Staphylococcal superantigen super-domains in immune evasion. 9713547 - Multiple host-feeding and biting persistence of aedes aegypti. 19713447 - Bone marrow stromal cells attenuate lung injury in a murine model of neonatal chronic l... 10841077 - Chemokine gene adjuvants can modulate immune responses induced by dna vaccines. |
Publication Detail:
|
Type: JOURNAL ARTICLE Date: 2011-2-9 |
Journal Detail:
|
Title: Journal of orthopaedic research : official publication of the Orthopaedic Research Society Volume: - ISSN: 1554-527X ISO Abbreviation: - Publication Date: 2011 Feb |
Date Detail:
|
Created Date: 2011-2-10 Completed Date: - Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 8404726 Medline TA: J Orthop Res Country: - |
Other Details:
|
Languages: ENG Pagination: - Citation Subset: - |
Copyright Information:
|
Copyright © 2011 Orthopaedic Research Society. |
Affiliation:
|
Department of Orthopaedic Surgery, Yamagata University School of Medicine, 2-2-2 Iida Nishi, Yamagata 990-9585, Japan. t.hirayama@med.id.yamagata-u.ac.jp. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
|
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Does high-flexion total knee arthroplasty promote early loosening of the femoral component?
Next Document: Don't hedge your bets: Hedgehog signaling as a central mediator of endochondral bone development and...