FAK Activation Promotes SMC Dedifferentiation via Increased DNA Methylation in Contractile Genes

Abstract

Rationale: Vascular smooth muscle cells (SMCs) exhibit remarkable plasticity and can undergo dedifferentiation upon pathological stimuli associated with disease and interventions. Objective: Although epigenetic changes are critical in SMC phenotype switching, a fundamental regulator that governs the epigenetic machineries regulating the fate of SMC phenotype has not been elucidated. Methods and Results: Using SMCs, mouse models, and human atherosclerosis specimens, we found that FAK (focal adhesion kinase) activation elicits SMC dedifferentiation by stabilizing DNMT3A (DNA methyltransferase 3A). FAK in SMCs is activated in the cytoplasm upon serum stimulation in vitro or vessel injury and active FAK prevents DNMT3A from nuclear FAK-mediated degradation. However, pharmacological or genetic FAK catalytic inhibition forced FAK nuclear localization, which reduced DNMT3A protein via enhanced ubiquitination and proteasomal degradation. Reduced DNMT3A protein led to DNA hypomethylation in contractile gene promoters, which increased SMC contractile protein expression. RNA-sequencing identified SMC contractile genes as a foremost upregulated group by FAK inhibition from injured femoral artery samples compared with vehicle group. DNMT3A knockdown in injured arteries reduced DNA methylation and enhanced contractile gene expression supports the notion that nuclear FAK-mediated DNMT3A degradation via E3 ligase TRAF6 (TNF [tumor necrosis factor] receptor-associated factor 6) drives differentiation of SMCs. Furthermore, we observed that SMCs of human atherosclerotic lesions exhibited decreased nuclear FAK, which was associated with increased DNMT3A levels and decreased contractile gene expression. Conclusions: This study reveals that nuclear FAK induced by FAK catalytic inhibition specifically suppresses DNMT3A expression in injured vessels resulting in maintaining SMC differentiation by promoting the contractile gene expression. Thus, FAK inhibitors may provide a new treatment option to block SMC phenotypic switching during vascular remodeling and atherosclerosis.

Vascular smooth muscle cells in intimal hyperplasia, an update

“…Furthermore, Jeong et al discovered that FAK, which is induced upon vascular injury, elicits VSMC dedifferentiation by stabilizing DNMT3A. They further show that FAK inhibition leads to DNMT3A degradation and DNA hypomethylation of contractile gene promoters, which increased VSMC contractile protein expression ( Jeong et al, 2021 ).…”

N6‐methyladenosine modification of CENPF mRNA facilitates gastric cancer metastasis via regulating FAK nuclear export

“…IF assays further confirmed that CENPF deficiency significantly restricted FAK in the nucleus (Figure 7H). Based on the report that PND-1186 is an inhibitor of FAK and that it can restrict FAK in the nucleus and inhibit its activity [32], we verified that PND-1186 could repress the activation of FAK and block FAK in the nucleus in GC cells (Supplementary Figure S4A-B). Finally, the effect of CENPF overexpression on the MAPK signaling pathway could be restored by PND-1186 in HGC27 and AGS cells (Figure 7I).…”

“…Abbreviations: IP, immunoprecipitation; MS, mass spectrometry; IF, immunofluorescence; CENPF, centromere protein F; FAK, focal adhesion kinase; DMSO, dimethyl sulfoxide; H3, histone 3; Erk1/2, extracellular signal-regulated kinase 1/2; Elk1, ETS-like gene 1; SD, standard deviation. its activity [32], a molecular mechanism by which CENPF activates the MAPK signaling pathway by promoting FAK entry into the cytoplasm was elucidated. This is the first report on the regulatory relationship between CENPF and FAK.…”

Integrins and Epithelial-Mesenchymal Cooperation in the Tumor Microenvironment of Muscle-Invasive Lethal Cancers

“…Reduced DNMT3A protein leads to DNA hypomethylation in contractile gene promoters, which increased SMC contractile protein expression. DNMT3A degradation via E3 ligase TRAF6 drives differentiation of SMCs ( Jeong et al, 2021 ). A unifying epigenetic mechanism also has been proposed that confers reversible SMC differentiation governed by the DNA-modifying enzyme ten-eleven translocation-2 (TET2).…”