Transcription factor NFAT5 promotes macrophage survival in rheumatoid arthritis
Susanna Choi, … , Chul-Soo Cho, Wan-Uk Kim
Susanna Choi, … , Chul-Soo Cho, Wan-Uk Kim
Published February 13, 2017
Citation Information: J Clin Invest. 2017;127(3):954-969. https://doi.org/10.1172/JCI87880.
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Research Article Immunology Inflammation

Transcription factor NFAT5 promotes macrophage survival in rheumatoid arthritis

Abstract

Defective apoptotic death of activated macrophages has been implicated in the pathogenesis of rheumatoid arthritis (RA). However, the molecular signatures defining apoptotic resistance of RA macrophages are not fully understood. Here, global transcriptome profiling of RA macrophages revealed that the osmoprotective transcription factor nuclear factor of activated T cells 5 (NFAT5) critically regulates diverse pathologic processes in synovial macrophages including the cell cycle, apoptosis, and proliferation. Transcriptomic analysis of NFAT5-deficient macrophages revealed the molecular networks defining cell survival and proliferation. Proinflammatory M1-polarizing stimuli and hypoxic conditions were responsible for enhanced NFAT5 expression in RA macrophages. An in vitro functional study demonstrated that NFAT5-deficient macrophages were more susceptible to apoptotic death. Specifically, CCL2 secretion in an NFAT5-dependent fashion bestowed apoptotic resistance to RA macrophages in vitro. Injection of recombinant CCL2 into one of the affected joints of Nfat5+/– mice increased joint destruction and macrophage infiltration, demonstrating the essential role of the NFAT5/CCL2 axis in arthritis progression in vivo. Moreover, after intra-articular injection, NFAT5-deficient macrophages were more susceptible to apoptosis and less efficient at promoting joint destruction than were NFAT5-sufficient macrophages. Thus, NFAT5 regulates macrophage survival by inducing CCL2 secretion. Our results provide evidence that NFAT5 expression in macrophages enhances chronic arthritis by conferring apoptotic resistance to activated macrophages.

Authors

Susanna Choi, Sungyong You, Donghyun Kim, Soo Youn Choi, H. Moo Kwon, Hyun-Sook Kim, Daehee Hwang, Yune-Jung Park, Chul-Soo Cho, Wan-Uk Kim

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Figure 7

NFAT5 promotes the survival of primary mouse macrophages by inducing CCL2 secretion.

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NFAT5 promotes the survival of primary mouse macrophages by inducing CCL...
(A) CCL2 secretion by macrophages from WT Nfat5+/+ and Nfat5+/– mice. Peritoneal macrophages (1 × 105 cells) were isolated 96 hours after i.p. injection of thioglycollate and then stimulated with LPS (100 ng/ml) for 24 hours. CCL2 concentrations in the culture supernatants were measured by ELISA. Data were compiled from 2 experiments (n = 4 mice per group) and are presented as the mean ± SD. *P < 0.05, by Mann-Whitney U test. (B) Increased apoptosis of splenic macrophages in response to anti-CCL2 Ab. Splenic macrophages (2 × 105 cells) from Nfat5+/+ mice were treated with anti-CCL2–neutralizing Ab (5 μg/ml) for 48 hours. The degree of apoptosis was determined by flow cytometry for annexin V. Data represent the mean ± SD of 3 independent experiments (n = 6 per group). *P < 0.05, by Mann-Whitney U test. (C) Reduced proliferation of thioglycollate macrophages in response to anti-CCL2 Ab. Thioglycollate peritoneal macrophages (1 × 105 cells) from Nfat5+/+ mice were stimulated with 10% FBS for 48 hours in the presence or absence of anti-CCL2 Ab (5 μg/ml). Cell viability was assessed by MTT assay. Data represent the mean ± SD of 3 independent experiments (n = 6 per group). *P < 0.05 between groups at each time point, by Mann-Whitney U test. (D) CCL2 restored apoptosis of Nfat5+/– macrophages. Splenic F4/80+ macrophages (2 × 105 cells) from Nfat5+/– mice were treated with recombinant CCL2 (200 ng/ml) for 6 days. Apoptosis was assessed by flow cytometry for annexin V. Data were compiled from 2 experiments (n = 4 mice per group). *P < 0.05, by Mann-Whitney U test.