Increased prevalence of semaphorin 3C, a repellent of sympathetic nerve fibers, in the synovial tissue of patients with rheumatoid arthritis.

Objective: The presence of selective sympathetic nerve repellents, i.e., semaphorins, may be responsible for the observed reduction of sympathetic innervation in the synovial tissue of patients with rheumatoid arthritis (RA).

Anti-inflammatory cooperativity of corticosteroids and norepinephrine in rheumatoid arthritis synovial tissue in vivo and in vitro.

Corticosteroids (CS) and norepinephrine (NE) support each other's biological effects. Thus, deficiency of cortisol and reduced synovial sympathetic innervation (SSI) may be proinflammatory in rheumatoid arthritis (RA). This study tested the anti-inflammatory cooperativity of CS and NE in human RA synovial tissue.

Norepinephrine from synovial tyrosine hydroxylase positive cells is a strong indicator of synovial inflammation in rheumatoid arthritis.

Objective: Density of sympathetic nerve fibers in synovial tissue was lower in patients with rheumatoid arthritis (RA) compared to those with osteoarthritis (OA). This was accompanied by norepinephrine (NE) release from synovial tyrosine hydroxylase positive cells (TH+ cells). We investigated the role of TH+ cells and NE in synovial inflammation.