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 8

Peripheral CD14+ cells from RA patients are resistant to apoptotic death.

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Peripheral CD14+ cells from RA patients are resistant to apoptotic death...
(A and B) Comparison of NFAT5 expression levels in CD14+ cells between PBMCs and SFMCs from patients with RA (n = 6) (cells were obtained simultaneously). (C) Correlation of CD14+ cell frequencies between paired SFMCs and PBMCs from patients with RA, as assessed by flow cytometry. (D) Increase in the proportion of CD14+ cells in PBMCs from patients with RA. The percentages of CD14+ cells in PBMCs from RA patients (n = 14) and healthy controls (n = 12) were assessed by flow cytometry. (E) Time kinetics for the frequency of CD14+ cells in PBMCs from RA patients (n = 5) versus normal controls (n = 4). PBMCs were cultured for 96 hours in RPMI 1640 containing 10% FBS. The proportion of CD14+ cells in PBMCs was determined by flow cytometry. (F) Increased viability of peripheral CD14+ cells from patients with RA. CD14+ cells (5 × 105 cells), isolated from PBMCs from RA patients (n = 7) and healthy controls (n = 6), were cultured for 96 hours in RPMI 1640 containing 10% FBS. Cell viability was determined by MTT assay. (G) Time kinetics of apoptosis in CD14+ cells from RA patients (n = 6) versus healthy controls (n = 6). CD14 cells (5 × 105 cells) were cultured for 96 hours in RPMI 1640 containing 10% FBS. Cell apoptosis was determined by flow cytometry for annexin V. (H) Decrease in the proportion of apoptotic CD14+ cells in PBMCs from patients with RA. Mononuclear cells were isolated from the peripheral blood of RA patients (n = 11) and healthy controls (n = 11). The proportion of annexin V+ cells in CD14+ cells was assessed by flow cytometry immediately after isolating the PBMCs. (I) A positive correlation between NFAT5 and CCL2 mRNA levels was found in CD14+ cells from patients with RA. Data in A and D–H represent the mean ± SD. (A and D–H) *P < 0.05, by Mann-Whitney U test. (B, C, and I) Statistical significance was determined by Spearman’s correlation analysis.