ABSTRACT
Objective To identify the susceptibile genes in a rat model for rheumatoid arthritis (RA),to determine whether sex affects disease onset and to define the mechanisms that impacts congenic genes on arthritis. Methods Arthritis-susceptible DA rats were compared with sex/age-matched congenic rats in which alleles were substituted with alleles from arthritis resistant PVG rats. Incomplete Freund's adjuvant (IFA) was injected from the base of the tail. Arthritis was visually scored, the messenger RNA (mRNA) levels of congenic genes and cytokine were determined by reverse transcription-polymerase chain reaction. The differences between two groups were analyzed using Mann-Whitney U test. Results In oil-induced arthritis (OIA), male congenic R16 rats deviated profoundly from DA rats by decreased arthritis severity (5.9±3.8 vs 9.3±2.3, P＜0.05 ), and markedly reduced lymph node mRNA levels for calsyntenin-3 (Clstn3) gene (0.7±0.4 vs 2.2±1.6, P＜0.01 ) and interleukin (IL)-17 (1.4±2.2 vs 2.7±2.9, P＜0.05) and IL-1β (1.5±2.1 vs 2.3±2.5,P＜0.05) levels. Conclusion Rat Clstn3 gene regulates the production of pro-inflammatory cytokines of OIA in male rats. The effect of arthritis-susceptible gene Clstn3 is gender-specific.