Transcription Factor NFAT5 Promotes Migration and Invasion of Rheumatoid Synoviocytes via Coagulation Factor III and CCL2

Abstract

Fibroblast-like synoviocytes (FLSs) play a key role in the progression of rheumatoid arthritis (RA) as a primary component of invasive hypertrophied pannus. FLSs of RA patients (RA-FLSs) exhibit cancer-like features, including promigratory and proinvasive activities that largely contribute to joint cartilage and bone destruction. In this study, we hypothesized that the NF of activated T cell 5 (NFAT5), a transcription factor involving tumor invasiveness, would control the migration and invasion of RA-FLSs. Analyses of transcriptomes demonstrated the significant involvement of NFAT5 in locomotion of RA-FLSs and that tissue factor (TF; also known as coagulation factor III) and CCL2 were the major downstream target genes of NFAT5 involving FLS migration and invasion. In cultured RA-FLSs, IL-1β and TGF-β increased TF and CCL2 expression by upregulating NFAT5 expression via p38 MAPK. Functional assays demonstrated that NFAT5- or TF-deficient RA-FLSs displayed decreased lamellipodia formation, cell migration, and invasion under IL-1β- or TGF-β-stimulated conditions. Conversely, factor VIIa, a specific activator of TF, increased migration of RA-FLSs, which was blocked by NFAT5 knockdown. Recombinant CCL2 partially restored the decrease in migration and invasion of NFAT5-deficient RA-FLSs stimulated with IL-1β. NFAT5-knockout mouse FLSs also showed decreased expressions of TF and CCL2 and reduced cell migration. Moreover, KRN2, a specific inhibitor of NFAT5, suppressed migration of FLSs stimulated with TGF-β. Conclusively, to our knowledge, this is the first study to provide evidence of a functional link between osmoprotective NFAT5 and TF in the migration and invasion of RA-FLSs and supports a role for NFAT5 blockade in the treatment of RA.

Role of NFAT5 in the Immune System and Pathogenesis of Autoimmune Diseases

“…In contrast, NFAT5-deficient macrophages exhibit reduced pro-inflammatory function, resulting in enhanced tumor growth in Lewis lung carcinoma and ID8 ovarian carcinoma models (43). Intriguingly, NFAT5-deficient macrophages show the reduced infiltration of effector CD8 + T cells into the tumor site (43), which is accordant with our findings of NFAT5 regulation of FLS migration (35). Together, in a sharp contrast to the tumorigenic role of NFAT5 in the cancer cells, NFAT5 in immune cells seems to escalate antitumor immunity by polarizing pro-inflammatory macrophages as well as promoting accumulation of CD8 + T cells adjacent to tumor masses.…”

“…Masuda et al first identified that NFAT5 mRNA is expressed in the RA synovia, particularly at sites of bone destruction (49). Along with this, our group has shown that NFAT5 is highly expressed in the RA-FLSs and that its expression in RA-FLSs is upregulated by the stimulation of pro-inflammatory cytokines such as IL-1β, TNF-α, and TGF-β (33, 35). Through the global gene expression profiling of RA-FLSs, we also found that NFAT5 is a major transcription factor for regulating the migration and invasion, an aggressive phenotype of RA-FLSs, which are mediated by the upregulation of CCL2- and tissue factor expressions as its downstream target genes (35).…”

“…The protein provides apoptotic resistance to RA macrophages by inducing CCL2 secretion (Figure 2) (33). Like that in macrophages, inflammatory stimuli-induced NFAT5 activation promotes the expression of tissue factor and CCL2 in the FLSs of RA patients (RA-FLSs), causing the hypermotility and invasiveness that are pathological features of RA (35). Next, during vascular injury, platelets, and other cells of the vasculature secrete platelet-derived growth factor-BB (PDGF-BB), which drives the proliferation and migration of vascular smooth muscle cells (SMCs) (36).…”

“…These cells can activate each other, constructing a very complex inter- and intracellular network of pro-inflammatory cytokines and chemokines including IL-1β, TNF-α, IL-6, and CCL2 (47). Chronic exposure to these pro-inflammatory cytokines, growth factors, and hypoxia may lead to abnormal proliferation of synovial fibroblasts, a pathologic hallmark of RA, and confer on these cells apoptotic resistance (35).…”

Enhanced Wound Healing- and Inflammasome-Associated Gene Expression in TNFAIP3-Interacting Protein 1- (TNIP1-) Deficient HaCaT Keratinocytes Parallels Reduced Reepithelialization

“…Additionally, PLAUR, the receptor for PLAU, increased~3.3-fold. F3, coagulation factor III (alias tissue factor), increased~2.5fold; it participates in signal transduction outside of blood coagulation such as inflammation and cell migration [47]. Not all ECM-remodeling enzymes on the array were universally increased in response to poly (I:C) challenge of TNIP1deficient HaCaT keratinocytes.…”