2. Academic Validation
  3. Down-regulation of A3AR signaling by IL-6-induced GRK2 activation contributes to Th17 cell differentiation

Down-regulation of A3AR signaling by IL-6-induced GRK2 activation contributes to Th17 cell differentiation

  • Exp Cell Res. 2021 Feb 15;399(2):112482. doi: 10.1016/j.yexcr.2021.112482.
Shanshan Hu 1,  Paipai Guo 2,  Zhen Wang 2,  Zhengwei Zhou 2,  Rui Wang 2,  Mei Zhang 2,  Juan Tao 2,  Yu Tai 2,  Weijie Zhou 2,  Wei Wei 3,  Qingtong Wang 4
Affiliations

Affiliations

  • 1 Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-inflammatory and Immune Medicine, Ministry of Education, Collaborative Innovation Center of Anti-inflammatory and Immune Medicines, Hefei, Anhui, 230032, China; Anhui No.2 Provincial People's Hospital, Hefei, Anhui, 230041, China.
  • 2 Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-inflammatory and Immune Medicine, Ministry of Education, Collaborative Innovation Center of Anti-inflammatory and Immune Medicines, Hefei, Anhui, 230032, China.
  • 3 Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-inflammatory and Immune Medicine, Ministry of Education, Collaborative Innovation Center of Anti-inflammatory and Immune Medicines, Hefei, Anhui, 230032, China. Electronic address: [email protected].
  • 4 Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-inflammatory and Immune Medicine, Ministry of Education, Collaborative Innovation Center of Anti-inflammatory and Immune Medicines, Hefei, Anhui, 230032, China. Electronic address: [email protected].
PMID: 33434531 DOI: 10.1016/j.yexcr.2021.112482
Abstract

IL-6-triggered Th17 cell expansion is responsible for the pathogenesis of many immune diseases including rheumatoid arthritis (RA). Traditionally, IL-6 induces Th17 cell differentiation through JAK-STAT3 signaling. In the present work, PKA inhibition reduces in vitro induction of Th17 cells, while IL-6 stimulation of T cells facilitates the internalization of A3AR and increased cAMP production in a GRK2 dependent manner. Inhibition of GRK2 by paroxetine (PAR) or genetic depletion of GRK2 restored A3AR distribution and prevented Th17 cell differentiation. Furthermore, in vivo PAR treatment effectively reduced the splenic Th17 cell proportion in a rat model of collagen-induced arthritis (CIA) which was accompanied by a significant improvement in clinical manifestations. These results indicate that IL-6-induced Th17 cell differentiation not only occurs through JAK-STAT3-RORγt but is also mediated through GRK2-A3AR-cAMP-PKA-CREB/ICER-RORγt. This elucidates the significance of GRK2-controlled cAMP signaling in the differentiation of Th17 cells and its potential application in treating Th17-driven immune diseases such as RA.

Keywords

Adenosine A3 receptor; G protein coupled receptor kinase 2; IL-6; Rheumatoid arthritis; T helper type 17.

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