Blockade of Nuclear Factor of Activated T Cells Activation Signaling Suppresses Balloon Injury-induced Neointima Formation in a Rat Carotid Artery Model

Abstract

We have previously reported that nuclear factor of activated T cells (NFATs) play an important role in the regulation of vascular smooth muscle cell migration and proliferation by receptor tyrosine kinase and G proteincoupled receptor agonists, platelet-derived growth factor-BB and thrombin, respectively. To understand the role of NFATs in vascular disease, we have now studied the involvement of these transcription factors in neointima formation in a rat carotid artery balloon injury model. The levels of NFATc1 in injured right common carotid arteries were increased at 72 h, 1 week, and 2 weeks after balloon injury compared with its levels in uninjured left common carotid arteries. Intraperitoneal injection of cyclosporine A (CsA), a pharmacological inhibitor of the calcineurin-NFAT activation pathway, suppressed balloon injury-induced neointima formation by 40%. Similarly, adenoviral-mediated expression of GFPVIVIT, a competent peptide inhibitor of the calcineurin-NFAT activation pathway, in injured arteries also reduced neointima formation by about 40%. Furthermore, CsA and GFPVIVIT attenuated balloon injury-induced neointimal smooth muscle cell proliferation as determined by bromodeoxyuridine staining. Platelet-derived growth factor-BB induced the expression of COX-2 in cultured VSMC in a time-and NFAT-dependent manner. COX-2 expression was also increased in the right common carotid artery in a time-dependent manner after balloon injury as compared with its levels in uninjured left common carotid artery and both CsA and GFPVIVIT negated this response. Together these results for the first time demonstrate that NFATs play a critical role in neointima formation via induction of expression of COX-2.

Nuclear Factor of Activated T Cells c1 Mediates p21-activated Kinase 1 Activation in the Modulation of Chemokine-induced Human Aortic Smooth Muscle Cell F-actin Stress Fiber Formation, Migration, and Proliferation and Injury-induced Vascular Wall Remodeling

“…We have reported previously that NFATs mediate injuryinduced vascular wall remodeling (16,19,20). In this study, we show that SM-specific NFATc1 knockdown, although having no effect on Rac1 stimulation, attenuates MCP1-induced cyclin D1 expression, CDK6 and CDK4 activities, and Pak1 activation.…”

The role of nuclear factor of activated T cells in pulmonary arterial hypertension

“…41,42 In VSMCs, the expression of NFATc1 is much higher than that of NFATc3 whereas NFATc2 and NFATc4 are not detectable. 43 Subcellular localization of NFATc1 in SMC (U8A4 cell line) varies under different differentiation state: 1) widely stained in the cytoplasm in dedifferentiated SMC; 2) perinuclear in differentiated SMC; and 3) nuclear in very differentiated cells.…”

Cyclin D1 Is a Bona Fide Target Gene of NFATc1 and Is Sufficient in the Mediation of Injury-induced Vascular Wall Remodeling

“…Adenoviral Vectors-Construction of Ad-GFP and Ad-GFPVIVIT was described previously (19). The human cyclin D1 was amplified by PCR using the following primers 5Ј-TTA ACC GTC GAC ATG GAC TAC AAA GAC CAT GAC-3Ј (forward) and 5Ј-ACA GGG ATG CCA CCC GGG ATC CTC TAG-3Ј (reverse) from the p3XFLAG-cyclin D1 expression vector (26) and subcloned into SalI and BamHI sites of pBlueScript.…”

“…Towards understanding the mechanisms of NFATs in the regulation of VSMC migration, we have shown that these transcriptional factors mediate interleukin-6 expression as one of the effector molecules in receptor tyrosine kinase (RTK) and G protein-coupled receptor (GPCR) agonist-induced VSMC motility (18). In addition, we have reported the involvement of NFATs in injury-induced neointima formation (19). Recently, we have also demonstrated that activation of NFATc1 causes up-regulation of the cell cycle dependent gene, cyclin A2, leading to increased CDK2 activity in VSMCs and the progression of these cells through the cell cycle (20).…”