Abstract:

[Abstract] Objective To explore the role of Th17- and Treg-derived catecholamines during collagen-induced ar? thritis (CIA) progression. Methods Eighteen male DBA/1 mice were randomly divided into control group, CIA model group Ⅰ (day 35) and CIA model group Ⅱ (day 55). The CIA models were induced by type Ⅱ collagen (CⅡ ) injection from tails. mRNA expression of Th17 specific transcription factor include ROR-γt, cytokines, IL-17 IL-22, Treg specific transcription factor, Foxp3, cytokines, TGF-β and tyrosine hydroxylase (TH) in lymph nodes were examined by real-time PCR. Co-local? ization of ROR-γt or Foxp3, with TH, vesicular monoamine transporter-2 (VMAT-2) or monoamine oxidase (MAO) in lymph nodes were observed by immunofluorescence staining. Results In lymph nodes of mice in CIA Ⅰ group and CIA Ⅱ group, mRNA expression of ROR-γt, IL-17, TH and IL-22 were upregulated, while mRNA expression of Foxp3 and TGF-β ex? pression was downregulated compared to those expression in control group. The upregulated expression of IL-17 was signifi? cantly reduced in CIA Ⅱ group compared with that in CIA Ⅰ group. In the lymph nodes of both intact and CIA mice, co-lo? calization of ROR-γt or Foxp3 with TH, VMAT-2 or MAO was seen in some cells. The numbers of cells that are double-pos? itive of ROR-γt/TH， ROR-γt/VMAT-2 and ROR-γt/MAO IL-17 were increased in CIA groups compared to those in con? trol group. And they are significantly reduced in CIA Ⅱ group compared with those in CIA Ⅰ group. Conclusion The abili? ty to synthesize catecholamines in Th17 cells was increased in lymph node in mice from CIA groups compared to that in con? trol group. The increased catecholamines production from Th17 cells in lymph nodes may be involved in the anti-inflammato? ry progression in CIA.

Key words: arthritis, rheumatoid, catecholamine, T- lymphocytes, regulatory, tyrosine 3- monooxygenase, Th17cells, Catecholamines