PT - JOURNAL ARTICLE AU - Zsuzsa Jenei-Lanzl AU - Silvia Capellino AU - Frieder Kees AU - Martin Fleck AU - Torsten Lowin AU - Rainer H Straub TI - Anti-inflammatory effects of cell-based therapy with tyrosine hydroxylase-positive catecholaminergic cells in experimental arthritis AID - 10.1136/annrheumdis-2013-203925 DP - 2015 Feb 01 TA - Annals of the Rheumatic Diseases PG - 444--451 VI - 74 IP - 2 4099 - http://ard.bmj.com/content/74/2/444.short 4100 - http://ard.bmj.com/content/74/2/444.full SO - Ann Rheum Dis2015 Feb 01; 74 AB - Objectives Studies in rheumatoid arthritis (RA), osteoarthritis (OA) and mice with arthritis demonstrated tyrosine hydroxylase-positive (TH+) cells in arthritic synovium and parallel loss of sympathetic nerve fibres. The exact function of TH+ cells and mode of TH induction are not known. Methods Synovial cells of RA/OA were isolated and cultured under normoxic/hypoxic conditions with/without stimulating enzyme cofactors of TH and inhibitors of TH. We studied TH expression and release of cytokines/catecholamines. In vivo function was tested by cell therapy with TH+ neuronal precursor cells (TH+ neuronal cells) in DBA/1 mice with collagen type II-induced arthritis (CIA). Results Compared with normoxic conditions, hypoxia increased TH protein expression and catecholamine synthesis and decreased release of tumour necrosis factor (TNF) in OA/RA synovial cells. This inhibitory effect on TNF was reversed by TH inhibition with α-methyl-para-tyrosine (αMPT), which was particularly evident under hypoxic conditions. Incubation with specific TH cofactors (tetrahydrobiopterin and Fe2+) increased hypoxia-induced inhibition of TNF, which was also reversed by αMPT. To address a possible clinical role of TH+ cells, murine TH+ neuronal cells were generated from mesenchymal stem cells. TH+ neuronal cells exhibited a typical catecholaminergic phenotype. Adoptive transfer of TH+ neuronal cells markedly reduced CIA in mice, and 6-hydroxydopamine, which depletes TH+ cells, reversed this effect. Conclusions The anti-inflammatory effect of TH+ neuronal cells on experimental arthritis has been presented for the first time. In RA/OA, TH+ synovial cells have TH-dependent anti-inflammatory capacities, which are augmented under hypoxia. Using generated TH+ neuronal cells might open new avenues for cell-based therapy.