Bacteria and Toll-like receptor and cytokine mRNA expression profiles associated with canine arthritis.

Abstract

The major forms of inflammatory canine arthritis are immune-mediated arthritis (IMA) and septic arthritis (SA), although some cases of cruciate disease (CD) are associated with significant levels of synovitis. In this study, the bacteria associated with canine arthritis were identified and mRNA expression levels of Toll-like receptors (TLRs) and pro-inflammatory cytokines determined. Of the 40 synovial fluid samples analysed, bacteria were isolated from 12 samples by culture (2 CD, 10 SA) and detected in 4 samples (3 CD, 1 SA) using culture-independent methods. Statistically significant increases in TLR2, tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-12 mRNA expression were seen in all disease groups compared to normal controls. All disease groups had decreased mRNA expression of other TLRs compared to normal controls, but this did not reach statistical significance. Synovial fluid cell counts revealed that the highest number and proportion of mononuclear cells and neutrophils were found in the IMA and SA samples, respectively. Age had an effect on the TLR and cytokine mRNA expression profiles: TNF-α (p=0.043) and IL-12 (p=0.025) mRNA expression was increased and TLR4 mRNA expression was reduced (p=0.033) in dogs up to 4 years of age compared to older animals. In the 10 SA samples from which bacteria were isolated, statistically significant increases in TLR2, TLR7, TNF-α and IL-6 mRNA expression were observed. It is concluded that canine arthritis is associated with increased mRNA levels of pro-inflammatory cytokines, which could in some cases be mediated by bacteria through activation of TLR2.

• Authors: Marcello P Riggio, David F Lappin, David Bennett
• Journal: Veterinary immunology and immunopathology (Vet Immunol Immunopathol) Vol. 160 Issue 3-4 Pg. 158-66 (Aug 15 2014) ISSN: 1873-2534 [Electronic] Netherlands
• PMID: 24856731 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 Elsevier B.V. All rights reserved.

Chemical References

• Cytokines
• Inflammation Mediators
• RNA, Messenger
• Toll-Like Receptors

Topics

• Aging (genetics, immunology)
• Animals
• Arthritis (genetics, microbiology, veterinary)
• Arthritis, Infectious (genetics, microbiology, veterinary)
• Bacteria (genetics, isolation & purification)
• Cytokines (genetics)
• Dog Diseases (genetics, immunology, microbiology)
• Dogs
• Genes, Bacterial
• Genes, rRNA
• Inflammation Mediators (metabolism)
• RNA, Messenger (genetics, metabolism)
• Synovial Fluid (immunology, microbiology)
• Synovitis (genetics, microbiology, veterinary)
• Toll-Like Receptors (genetics)
• Transcriptome