Table 3

Effect of synovial microparticles on the release of inflammatory mediators by fibroblast-like synoviocytes from arthritic patients (n = 11)

Mediator

Control

P*

MP-free synovial fluid

MP (1×)

Nx/Nt

P

MP (3×)

Nx/Nt

P


Unstimulated

IL-1β


MCP-1 (pg/ml)

456

4,754

0.001

469

488

6/11

0.010

900

4/6

0.156

(355–1,292)

(2,492–6,081)

(293–1,241)

(338–1,481)

higher

(346–2,326)

higher

sICAM-1 (ng/ml)

0.09

0.40

0.007

1.04

2.00

8/11

0.010

6.07

6/6

0.031

(0–0.3)

(0–0.76)

(0.34–1.84)

(0.35–4.07)

higher

(0.91–11.75)

higher

IL-8 (pg/ml)

0

8,642

0.001

26

301

5/11

0.008

790

6/6

0.031

(0–564)

(2,954–18,330)

(0–528)

(0–707)

higher

(0–2,100)

higher

IL-6 (pg/ml)

74

4949

0.001

110

136

7/11

0.042

436

6/6

0.031

(24–1,710)

(1,870–22,797)

(30–1,176)

(34–1,937)

higher

(44–3,766)

higher

VEGF (pg/ml)

48

79

0.014

34

74

10/11

0.001

111

6/6

0.078

(11–102)

(7–141)

(1–97)

(28–138)

higher

(27–161)

higher

GM-CSF (pg/ml)

32

53

0.004

31

22

10/11

0.002

18

6/6

0.016

(28–40)

(40–72)

(26–70)

(14–43)

lower

(14–25)

lower

RANTES (pg/ml)

0

138

0.001

0

0.2

4/11

0.031

4.2

5/6

0.062

(0–74)

(46–277)

(0–58)

(0–86)

higher

(0–32)

higher


Results are medians, with ranges in parentheses. Concentrations of mediators were determined in the culture supernatant of the fibroblast-like synoviocytes (FLS) by ELISA as described in the Materials and methods section. FLS were incubated for 24 hours with 1 ml of culture medium containing 1% FCS (negative control), 975 μl of culture medium supplemented with either (1) 25 μl of interleukin (IL)-1β (final concentration 125 pg/ml; positive control), (2) 25 μl (onefold (1×) or threefold (3×) concentrated) microparticles (MP), or (3) MP-free synovial fluid. P*, positive versus negative control; P, MP (1×) versus MP-free synovial fluid; P, MP (3×) versus MP (1×). Nx/Nt, number of individual culture supernatants that contained elevated or decreased concentrations of mediators after incubation for 24 hours with isolated MP compared with MP-free synovial fluid, divided by the number of patients studied. GM-CSF, granulocyte/macrophage colony-stimulating factor; sICAM-1, soluble intracellular adhesion molecule-1; MCP-1, monocyte chemoattractant protein-1; VEGF, vascular endothelial growth factor.

Berckmans et al. Arthritis Research & Therapy 2005 7:R536-R544   doi:10.1186/ar1706

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