[HDL inhibit cytokine production in a mouse model of urate crystal-induced inflammation].
OBJECTIVE
To evaluate whether high density lipoproteins (HDL) affect monosodium urate (MSU) crystal-induced inflammation in the murine air pouch model.


METHODS
MSU crystals were prepared by Denko's method and sterilized by heating at 180°C for 2 h before each experiment. Human HDL were isolated from peripheral blood of healthy volunteers. MSU crystals (2 mg in 1 ml of PBS) were injected into subcutaneous air pouches in mice in the presence or absence of HDL (0.1 mg). Negative control pouches received 1 ml of PBS. To recover pouch fluid, the pouches were washed with 2 ml of PBS after the animals were sacrificed. The leukocyte count in the lavage fluids was obtained using a hemocytometer and differential leukocyte count was determined by May-Grunwald-Giemsa staining. IL-6, KC, CCL2 and TNF-α levels were measured in exudates by ELISA.


RESULTS
MSU crystals increased the number of leukocytes and the neutrophil migration, as well as the concentrations of IL-6, KC and CCL2 in pouch fluids, while the TNF-α levels were not detectable. The treatment with HDL led to a reduction in all inflammatory parameters: the leukocyte count decreased by 73%; the neutrophil density decreased by 35%; the IL-6, KC and CCL2 concentration decreased by 4-, 6- and 5-fold respectively.


CONCLUSIONS
This study shows that HDL may limit the inflammatory process by inhibiting leukocyte recruitment and cytokine release. HDL are likely to represent a mechanism of control of crystal-induced inflammation.
Cattedra e U.O.C. di Reumatologia, Università di Padova, Padova, Italia. anna.scanu@unipd.it
A
A
Scanu
F
F
Oliviero
R
R
Luisetto
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P
Sfriso
J M
JM
Dayer
D
D
Burger
L
L
Punzi
D000818:Animals; D016207:Cytokines / Q000037:antagonists & inhibitors* / Q000096:biosynthesis*; D004195:Disease Models, Animal; D007249:Inflammation / Q000276:immunology*; D008075:Lipoproteins, HDL / Q000494:pharmacology*; D008297:Male; D051379:Mice; D014527:Uric Acid / Q000008:administration & dosage
D016207:Cytokines; D008075:Lipoproteins, HDL; D014527:Uric Acid