Research paper
Effect of Mycoplasma bovis on expression of inflammatory cytokines and matrix metalloproteinases mRNA in bovine synovial cells

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Highlights

Abstract

Mycoplasma bovis causes chronic arthritis in calves. Mycoplasma arthritis shows severe inflammatory reactions in joints that is commonly treated with antibiotics and results in significant economic losses in the calf industry. A previous study showed that inflammatory cytokines and matrix metalloproteinases (MMPs) produced by synovial cells promote progression of the pathophysiology of bacterial arthritis. However, the mechanism underlying the pathogenesis of bovine Mycoplasma arthritis has not been fully clarified. In this study, we examined the immunologic response of bovine synovial tissue to M. bovis. We observed significant increases in expression of interleukin (IL)-1β, IL-6, IL-8, MMP-1, and MMP-3 mRNA in synovial tissue from Mycoplasma arthritis calves compared with tissues from normal calves. Expression of IL-6, IL-8, and MMP-1 mRNA was also induced in cultured synovial cells stimulated with M. bovis, but not expression of IL-1β and MMP-3 mRNA. In contrast, the culture supernatant of peripheral blood mononuclear cells stimulated with M. bovis induced marked increases in the expression of IL-1β, IL-6, IL-8, MMP-1, and MMP-3 mRNA in synovial cells. Our results indicate that inflammatory cytokines and MMPs produced by synovial cells play a key role in the pathogenesis of Mycoplasma arthritis. We suggest that interactions between synovial cells and mononuclear cells in the presence of M. bovis induce expression of these cytokines and MMPs in synovial cells, resulting in severe inflammatory reactions in the joints.

Introduction

Mycoplasmas are bacteria of the class Mollicutes which do not have a cell wall and cause widespread infections in eukaryotes (Razin et al., 1998). Mycoplasma bovis is a significant pathogen of cattle, causing mastitis (Fox, 2012), pneumonia (Maunsell et al., 2011), and arthritis (Gagea et al., 2006). Mycoplasma arthritis (MA) is a group of intractable diseases commonly treated with antibiotics and associated with significant economic losses in the calf industry (Nicholas, 2011). MA shows synovial hyperplasia and osteolysis caused by severe inflammatory reactions in the joints (Gagea et al., 2006; Mahmood et al., 2017). However, the mechanism of the immune response to M. bovis in bovine synovial tissue has not been elucidated.

Synovial cells play an important role in the immune response in joints (Bartok and Firestein, 2010; Haerdi-Landerer et al., 2011). Inflammatory cytokines induce severe inflammatory reactions and contribute to progression of the pathophysiology of bacterial arthritis (Abdelnour et al., 1994; Nair et al., 1996). Matrix metalloproteinases (MMPs) are a major group of enzymes that degrade the extracellular matrix (ECM), including collagen, proteoglycan, and elastin (Visse and Nagase, 2003). MMP activity is regulated by tissue inhibitors of metalloproteinases (TIMPs), which are specific inhibitors that bind MMPs in a 1:1 stoichiometry (Visse and Nagase, 2003).

Synovial cells produce inflammatory cytokines, MMPs, and TIMPs, each of which play key roles in the pathogenesis of human and murine bacterial arthritis (Behera et al., 2005; Kanangat et al., 2006). As indicated above, however, the immune responses in bovine synovial tissue infected with M. bovis have not been fully elucidated. Therefore, in this study, we examined the immunologic characteristics of bovine synovial tissue to M. bovis.

Section snippets

Synovial fluid (SF) and synovial tissue

We obtained 11 clinically healthy (control) calves and 6 calves with chronic spontaneous MA (1 to 4 months of age) from different commercial dairy farms between 2015 and 2017. SF (from 11 control and 6 MA calves) and synovial tissue (from 4 control and 4 MA calves) were isolated from the knee joints of dissected calves. MA calves were diagnosed based on the results of PCR analyses using M. bovis–specific primers, as previously described (Higuchi et al., 2011). Briefly, SF was inoculated into

SF pH, protein concentration, and number of SF cells isolated from control and MA calves

The pH, protein concentration, and number of SF cells are shown in Fig. 1. The pH of SF from MA calves was 7.3 ± 0.1, which was significantly (p < 0.05) lower than that of control calves (7.9 ± 0.1). The concentration of protein in SF was significantly (p < 0.01) higher in MA calves (8.1 ± 0.9 g/dL) than in control calves (1.9 ± 0.1 g/dL). The SF of MA calves contained 2.9 ± 0.8 × 107 cells/mL, which was significantly (p < 0.01) higher than the number of cells in the SF of control calves (4.0 ±

Discussion

Infection with M. bovis causes chronic arthritis in calves that typically responds poorly to treatment with antimicrobial agents, resulting in significant economic losses in the calf industry (Nicholas et al., 2011). Chronic MA exhibits with synovial hyperplasia and osteolysis caused by severe inflammatory reactions in the joints (Gagea et al., 2006; Mahmood et al., 2017). Previous studies showed that inflammatory cytokines and MMPs produced by synovial cells induce the development of bacterial

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

References (41)

  • V. Spalenza et al.

    Identification of internal control genes for quantitative expression analysis by real-time PCR in bovine peripheral lymphocytes

    Vet. J.

    (2011)
  • A. Abdelnour et al.

    Role of T lymphocytes in experimental staphylococcus aureus arthritis

    Scand. J. Immunol.

    (1994)
  • T. Alonzi et al.

    Interleukin 6 is required for the development of collagen-induced arthritis

    J. Exp. Med.

    (1998)
  • M.P. Bambara et al.

    Cell contact between T cells and synovial fibroblasts causes induction of adhesion molecules and cytokines

    J. Leukoc. Biol.

    (1993)
  • B. Bartok et al.

    Fibroblast-like synoviocytes: key effector cells in rheumatoid arthritis

    Immunol. Rev.

    (2010)
  • A.K. Behera et al.

    Induction of host matrix metalloproteinases by Borrelia burgdorferi differs in human and murine Lyme arthritis

    Infect. Immun.

    (2005)
  • A. Blauvelt et al.

    The immunologic role of IL-17 in psoriasis and psoriatic arthritis pathogenesis

    Clin. Rev. Allergy Immunol.

    (2018)
  • T. Bremell et al.

    Histopathological and serological progression of experimental Staphylococcus aureus arthritis

    Infect. Immun.

    (1992)
  • H. Endo et al.

    Elevation of interleukin-8 (IL-8) levels in joint fluids of patients with rheumatoid arthritis and the induction by IL-8 of leukocyte infiltration and synovitis in rabbit joints

    Lymphokine Cytokine Res.

    (1991)
  • D. Francoz et al.

    Synovial fluid changes in induced infectious arthritis in calves

    J. Vet. Intern. Med.

    (2005)
  • Cited by (0)

    1

    Present address: Division of Bacterial and Parasitic Disease, National Institute of Animal Health, National Agriculture and Food Research Organization, Tsukuba, Ibaraki 305-0856, Japan.

    2

    Present address: Cattle Research Center, Ebetsu, Hokkaido 069-0804, Japan.

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