Catecholamine-producing cells in the synovial tissue during arthritis: modulation of sympathetic neurotransmitters as new therapeutic target.

BACKGROUND: The proinflammatory and anti-inflammatory role of the sympathetic nervous system in early and late inflammation is an unresolved paradox. A drastic loss of sympathetic nerve fibres in the synovial tissue of patients with rheumatoid arthritis (RA) has previously been demonstrated. The presence of tyrosine hydroxylase (TH)-positive cells in RA and osteoarthritis (OA) has been determined, but the role of these cells in inflammation is still unclear. OBJECTIVE: To characterise TH-positive cells in inflamed RA and OA synovial tissue and to study their role in inflammation. METHODS: Synovial samples were obtained from 32 patients with OA and 19 patients with RA and from 10 control patients. Synovial tissue samples were used for immunofluorescence staining. Synovial cells were isolated by tissue digestion and immediately used for cell culture. For in vivo experiments, collagen type-II arthritis in DBA/1J mice was induced. RESULTS: TH+ cells were present only in inflamed tissue and not in controls. Catecholamine-storing vesicles and vesicular monoamine transporter 2 (VMAT2) were identified in the synovial tissue. Experimental increase of cytoplasmic catecholamines by VMAT2 blockade strongly reduced tumour necrosis factor (TNF) independently of canonical extracellular \u3b2-adrenergic signalling. In addition, VMAT2 blockade increased cyclic AMP (cAMP) and cAMP responsive element binding protein, responsible for TNF inhibition. In vivo, appearance of VMAT2 positive cells was confirmed. VMAT2 blockade ameliorated inflammation also in vivo. CONCLUSIONS: This study demonstrates that local catecholamine-producing cells start to replace sympathetic nerve fibres around the onset of disease, and modulation of locally produced catecholamines has strong anti-inflammatory effects in vivo and in vitro

Psoriatic arthritis : Clinical improvement and correlation with hormone axes in etanercept-treated patients : Annals of the New York Academy of Sciences

In a chronic inflammatory disease, such as rheumatoid arthritis (RA), the hypothalamic-pituitary-adrenal axis is altered in three ways: (1) the inflammation-related spontaneous and stimulated secretion of cortisol is inadequate; (2) the inflammation-related secretion of adrenocorticotropic hormone (ACTH) is low; and (3) the levels of adrenal androgens decrease. In patients with RA, long-term therapy with anti-TNF therapy sensitizes the pituitary gland and improves adrenal androgen secretion. We have recently found that the mean serum levels of ACTH, cortisol, 17-hydroxyprogesterone (17OHP), and androstenedione (ASD) in 11 prednisolone-na\uefve patients with psoriatic arthritis did not markedly change during 12 weeks of etanercept treatment, nor did the serum cortisolACTH ratio. However, the greater increase in serum cortisol in comparison with serum 17OHP or ASD was related to clinical improvement, which indicates that the improvement was more related to the higher cortisol levels