Hematoxylin-Eosin (H&E) staining and Histopathological
examination
After decalcification of mice joints in 10% EDTA, together with human
synovial tissues, they were embedded in paraffin, and stained with H&E
staining for light microscopy. Histopathological quantification was made
by investigators in a blinded manner from images of three fields
representing the distal interphalangeal joint, the proximal
interphalangeal joint, and joints in the carpal region and averaged over
all joints in one limb of each animal. Inflammation was scored 0 to 5
according to the following criteria: 0, normal; 1, minimal inflammatory
infiltration; 2, mild infiltration; 3, moderate infiltration with
moderate edema; 4, marked infiltration with marked edema; and 5, severe
infiltration with edema. Hyperplasia was defined as synovial tissue
intimately invading bone and/or cartilage and was scored 0 to 3 as
follows: 0, none; 1, minimal; 2, moderate; 3, severe. Bone degradation
was scored using the following 0 to 3 scale: 0, no bone erosion; 1, mild
surface erosion; 2, moderate surface erosion; and 3, strong surface
erosion. Sections were also stained by Safranin O/ Fast green kit
(Solarbio) for detection of cartilage damage (0: no changes; 1: erosion
in part of the cartilage surface; 2: erosion of the cartilage surface
and cartilage destruction; 3: cartilage erosion and destruction,
combined with cartilage covered by connective tissue; 4: Cartilage and
cartilage covered by connective tissue are corroded and damaged
severely).