Transcriptomic analysis of forelimb joint synovial tissues in collagen-induced arthritis mice treated with F20

Collagen-induced arthritis (CIA) was established in DBA/1 male mice using bovine type II collagen emulsified in Freund’s adjuvant. Arthritis severity was scored by an arthritis index, and CIA-positive animals were randomized to a CIA group or a CIA+F20 group (10 mg/kg,p.o. once daily for 21 days); age-matched non-immunized mice served as healthy controls. At endpoint, both forelimbs were collected by cutting at the elbow level to retain the forearm, wrist, and paw. Skin and excess muscle were removed while preserving joint capsules, synovium, and periarticular tissues for RNA-seq. Total RNA was extracted, mRNA libraries were prepared and sequenced (paired-end) on an MGI platform. Clean reads were obtained with fastp, aligned to Mus_musculus.GRCm39.109 (Ensembl) using HISAT2, and quantified with featureCounts.