TNF-α elicits phenotypic and functional alterations of vascular smooth muscle cells by miR-155-5p–dependent down-regulation of cGMP-dependent kinase 1

Abstract

cGMP-dependent protein kinase 1 (PKG1) plays an important role in nitric oxide (NO)/cGMP-mediated maintenance of vascular smooth muscle cell (VSMC) phenotype and vasorelaxation. Inflammatory cytokines, including tumor necrosis factor-α (TNFα), have long been understood to mediate several inflammatory vascular diseases. However, the underlying mechanism of TNFα-dependent inflammatory vascular disease is unclear. Here, we found that TNFα treatment decreased PKG1 expression in cultured VSMCs, which correlated with NF-κB-dependent biogenesis of miR-155-5p that targeted the 3'-UTR of PKG1 mRNA. TNFα induced VSMC phenotypic switching from a contractile to a synthetic state through the down-regulation of VSMC marker genes, suppression of actin polymerization, alteration of cell morphology, and elevation of cell proliferation and migration. All of these events were blocked by treatment with an inhibitor of miR-155-5p or PKG1, whereas transfection with miR-155-5p mimic or PKG1 siRNA promoted phenotypic modulation, similar to the response to TNFα. In addition, TNFα-induced miR-155-5p inhibited the vasorelaxant response of de-endothelialized mouse aortic vessels to 8-Br-cGMP by suppressing phosphorylation of myosin phosphatase and myosin light chain, both of which are downstream signal modulators of PKG1. Moreover, TNFα-induced VSMC phenotypic alteration and vasodilatory dysfunction were blocked by NF-κB inhibition. These results suggest that TNFα impairs NO/cGMP-mediated maintenance of the VSMC contractile phenotype and vascular relaxation by down-regulating PKG1 through NF-κB-dependent biogenesis of miR-155-5p. Thus, the NF-κB/miR-155-5p/PKG1 axis may be crucial in the pathogenesis of inflammatory vascular diseases, such as atherosclerotic intimal hyperplasia and preeclamptic hypertension.

Circulating miRNAs Associated with Dysregulated Vascular and Trophoblast Function as Target-Based Diagnostic Biomarkers for Preeclampsia

“…Furthermore, the elevated NOx levels in the patients were negatively correlated with eNOS mRNA levels and positively correlated with iNOS mRNA levels ( Figure 2 H,I), suggesting that the increased NO/cGMP levels in the patients might be derived from increased iNOS expression. Since inflammatory cytokines, including TNF-α, stimulate the iNOS/NO/cGMP pathway [ 26 ] and inhibit the eNOS/NO/cGMP pathway [ 15 , 16 , 17 , 18 , 19 ], the relationship between serum levels of TNF-α and eNOS or iNOS expression was assessed. Our results showed that the serum TNF-α levels were significantly increased in PE patients ( Figure 2 J) and positively correlated with the sFlt1/PlGF ratio ( Figure 2 K).…”

“…Our recent studies demonstrated that miRNA (miR)-31-5p and miR-155-5p are detected at high levels in sera from patients with PE. These miRNAs elicit vascular dysfunction associated with hypertension and proteinuria through the impairment of the endothelial nitric oxide synthase/nitric oxide (eNOS/NO) and soluble guanylate cyclase/protein kinase G (sGC/PKG) pathways [ 15 , 16 , 17 , 18 , 19 ]. This suggests that PE-derived miRNAs associated with the impairment of vasorelaxation and vascular remodeling can be used as diagnostic and therapeutic biomarkers of PE.…”

Human Umbilical Cord Mesenchymal Stem Cells Attenuate Abdominal Aortic Aneurysm Progression in Sprague-Dawley Rats: Implication of Vascular Smooth Muscle Cell Phenotypic Modulation

“…TNF-α is primarily produced by monocyte macrophage system in AAA [ 26 , 47 ]. Previous studies have revealed that TNF-α could induce VSMCs from contractile to synthetic phenotype through the downregulation of VSMC-specific contractile genes [ 48 , 49 ]. In this study, we demonstrated that UC-MSCs suppress TNF-α expression during AAA initiation and progression, which implies that UC-MSCs might promote the phenotypic transition of VSMCs through indirect pathways, such as downregulating the expression level of TNF-α.…”

Triiodothyronine Reduces Vascular Dysfunction Associated with Hypertension by Attenuating Protein Kinase G/Vasodilator-Stimulated Phosphoprotein Signaling

“…PKG plays an important role in maintenance of vascular smooth muscle phenotype and vascular relaxation (Choi et al, 2018). Activation of PKG in VSMC can lead to phosphorylation of VASP at serine 239, resulting in vascular relaxation (Holt et al, 2016).…”