Fig. 1

Leucine-rich alpha 2 glycoprotein (LRG) knockout (KO) mice are protected against collagen-induced arthritis (CIA). Male wild-type (WT) mice and LRG KO mice were subjected to CIA. a The serum levels of LRG in WT mice (n = 6–8) on indicated days after arthritis induction were determined by ELISA. Values are mean ± SD; **p < 0.01, Dunnett’s test. b Representative immunohistochemical analysis of LRG in wrist and ankle joints from non-treated WT mice or mice with CIA on day 35 after arthritis induction. c Representative macroscopic joint symptoms in WT mice or LRG KO mice on day 35 after arthritis induction. d, e The symptoms of arthritis were scored (0–4 per limb) until day 70. The arthritis score (d) and maximum arthritis score (e) are shown for WT mice (n = 12) and LRG KO mice (n = 11). Values are mean ± SD: *p < 0.05, Mann-Whitney U test. f Representative histological appearance of joints from a WT mouse and LRG KO mouse on day 35 after arthritis induction. Joints were stained with hematoxylin and eosin (left and middle panel) or safranin O (right panel)