Matrix metalloproteinase-9 (gelatinase B) deficiency leads to increased severity of Staphylococcus aureus-triggered septic arthritis.

• Matrix metalloproteinases constitute a family of structurally related endopeptidases that are crucial for the normal turnover of the extracellular matrix. Elevated levels of MMP-9 have been demonstrated in synovial fluids of rheumatoid arthritis patients, and a correlation with the severity of the disease has been described. The aim of this study was to explore the impact of MMP-9 expression on joint inflammation and destruction in a model of bacterially induced septic arthritis. MMP-9 knock-out mice and C57Bl6 congenic controls were inoculated intravenously or intra-articularly with Staphylococcus aureus. Arthritis was evaluated clinically and by means of histology. Zymographic analyses were performed to study ex vivo induction of MMP-9 following exposure to S. aureus. The MMP-9 knock-out mice displayed a significantly higher frequency and severity, but not destructivity, of arthritis than did the wild-type mice. The knock-out mice also proved to harbour an increased number of bacteria locally in joints and systemically in kidneys, possibly by impaired extravasation and recruitment of leukocytes and a deficient early defence against infection. Our findings indicate that deficiency in MMP-9 increases the degree of joint inflammation due to decreased bacterial clearance.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Immunologi inom det medicinska området (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Immunology in the medical area (hsv//eng)

Nyckelord

Animals

Arthritis

Infectious

enzymology

immunology

microbiology

pathology

Cell Growth Processes

physiology

Disease Models

Animal

Electrophoresis

Polyacrylamide Gel

Female

Histocytochemistry

Interleukin-6

metabolism

Joints

enzymology

immunology

microbiology

pathology

Matrix Metalloproteinase 9

deficiency

immunology

Mice

Mice

Inbred C57BL

Mice

Knockout

Staphylococcal Infections

enzymology

immunology

microbiology

Staphylococcus aureus

immunology

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)