scholarly journals FoxO4 Regulates Tumor Necrosis Factor Alpha-Directed Smooth Muscle Cell Migration by Activating Matrix Metalloproteinase 9 Gene Transcription

2007 ◽  
Vol 27 (7) ◽  
pp. 2676-2686 ◽  
Author(s):  
Hao Li ◽  
Jianping Liang ◽  
Diego H. Castrillon ◽  
Ronald A. DePinho ◽  
Eric N. Olson ◽  
...  

ABSTRACT Phenotypic modulation of vascular smooth muscle cells (SMCs) in the blood vessel wall from a differentiated to a proliferative state during vascular injury and inflammation plays an important role in restenosis and atherosclerosis. Matrix metalloproteinase 9 (MMP9) is a member of the MMP family of proteases, which participate in extracellular matrix degradation and turnover. MMP9 is upregulated and required for SMC migration during the development of restenotic and atherosclerotic lesions. In this study, we show that FoxO4 activates transcription of the MMP9 gene in response to tumor necrosis factor alpha (TNF-α) signaling. Inhibition of FoxO4 expression by small interfering RNA or gene knockout reduces the abilities of SMCs to migrate in vitro and inhibit neointimal formation and MMP9 expression in vivo. We further show that both the N-terminal, Sp1-interactive domain and the C-terminal transactivation domain of FoxO4 are required for FoxO4-activated MMP9 transcription. TNF-α signaling upregulates nuclear FoxO4. Our studies place FoxO4 in the center of a transcriptional regulatory network that links gene transcription required for SMC remodeling to upstream cytokine signals and implicate FoxO4 as a potential therapeutic target for combating proliferative arterial diseases.

2013 ◽  
Vol 33 (10) ◽  
pp. 1564-1573 ◽  
Author(s):  
Muhammad S Ali ◽  
Robert M Starke ◽  
Pascal M Jabbour ◽  
Stavropoula I Tjoumakaris ◽  
L Fernando Gonzalez ◽  
...  

Little is known about vascular smooth muscle cell (SMC) phenotypic modulation in the cerebral circulation or pathogenesis of intracranial aneurysms. Tumor necrosis factor-alpha (TNF-α) has been associated with aneurysms, but potential mechanisms are unclear. Cultured rat cerebral SMCs overexpressing myocardin induced expression of key SMC contractile genes (SM-α-actin, SM-22α, smooth muscle myosin heavy chain), while dominant-negative cells suppressed expression. Tumor necrosis factor-alpha treatment inhibited this contractile phenotype and induced pro-inflammatory/matrix-remodeling genes (monocyte chemoattractant protein-1, matrix metalloproteinase-3, matrix metalloproteinase-9, vascular cell adhesion molecule-1, interleukin-1 beta). Tumor necrosis factor-alpha increased expression of KLF4, a known regulator of SMC differentiation. Kruppel-like transcription factor 4 (KLF4) small interfering RNA abrogated TNF-α activation of inflammatory genes and suppression of contractile genes. These mechanisms were confirmed in vivo after exposure of rat carotid arteries to TNF-α and early on in a model of cerebral aneurysm formation. Treatment with the synthesized TNF-α inhibitor 3,6-dithiothalidomide reversed pathologic vessel wall alterations after induced hypertension and hemodynamic stress. Chromatin immunoprecipitation assays in vivo and in vitro demonstrated that TNF-α promotes epigenetic changes through KLF4-dependent alterations in promoter regions of myocardin, SMCs, and inflammatory genes. In conclusion, TNF-α induces phenotypic modulation of cerebral SMCs through myocardin and KLF4-regulated pathways. These results demonstrate a novel role for TNF-α in promoting a pro-inflammatory/matrix-remodeling phenotype, which has important implications for the mechanisms behind intracranial aneurysm formation.


Antioxidants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 620 ◽  
Author(s):  
Cheng-Chung Chou ◽  
Chi-Ping Wang ◽  
Jing-Hsien Chen ◽  
Hui-Hsuan Lin

The proliferation and migration of vascular smooth muscle cells (VSMCs) are major events in the development of atherosclerosis following stimulation with proinflammatory cytokines, especially tumor necrosis factor-alpha (TNF-α). Plant-derived polyphenols have attracted considerable attention in the prevention of atherosclerosis. Hibiscus leaf has been showed to inhibit endothelial cell oxidative injury, low-density lipoprotein oxidation, and foam cell formation. In this study, we examined the anti-atherosclerotic effect of Hibiscus leaf polyphenols (HLPs) against abnormal VSMC migration and proliferation in vitro and in vivo. Firstly, VSMC A7r5 cells pretreated with TNF-α were demonstrated to trigger abnormal proliferation and affect matrix metalloproteinase (MMP) activities. Non-cytotoxic doses of HLPs abolished the TNF-α-induced MMP-9 expression and cell migration via inhibiting the protein kinase PKB (also known as Akt)/activator protein-1 (AP-1) pathway. On the other hand, HLP-mediated cell cycle G0/G1 arrest might be exerted by inducing the expressions of p53 and its downstream factors that, in turn, suppress cyclin E/cdk2 activity, preventing retinoblastoma (Rb) phosphorylation and the subsequent dissociation of Rb/E2F complex. HLPs also attenuated reactive oxygen species (ROS) production against TNF-α stimulation. In vivo, HLPs improved atherosclerotic lesions, and abnormal VSMC migration and proliferation. Our data present the first evidence of HLPs as an inhibitor of VSMC dysfunction, and provide a new mechanism for its anti-atherosclerotic activity.


2007 ◽  
Vol 27 (8) ◽  
pp. 2997-3007 ◽  
Author(s):  
Edwige Tellier ◽  
Anne Nègre-Salvayre ◽  
Beatrice Bocquet ◽  
Shigeyoshi Itohara ◽  
Yusuf A. Hannun ◽  
...  

ABSTRACT Neutral sphingomyelinase (nSMase), the initial enzyme of the sphingolipid signaling pathway, is thought to play a key role in cellular responses to tumor necrosis factor alpha (TNF-α), such as inflammation, proliferation, and apoptosis. The mechanism of TNF-α-induced nSMase activation is only partly understood. Using biochemical, molecular, and pharmacological approaches, we found that nSMase activation triggered by TNF-α is required for TNF-α-induced proliferation and in turn requires a proteolytic cascade involving furin, membrane type 1 matrix metalloproteinase (MT1-MMP), and MMP2, and leading finally to extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation and DNA synthesis, in smooth muscle cells (SMC) and fibroblasts. Pharmacological and molecular inhibitors of MMPs (batimastat), furin (α1-PDX inhibitor-transfected SMC), MT1-MMP (SMC overexpressing a catalytically inactive MT1-MMP), MMP2 (fibroblasts from MMP2−/− mice), and small interfering RNA (siRNA) strategies (siRNAs targeting furin, MT1-MMP, MMP2, and nSMase) resulted in near-complete inhibition of the activation of nSMase, sphingosine kinase-1, and ERK1/2 and of subsequent DNA synthesis. Exogenous MT1-MMP activated nSMase and SMC proliferation in normal but not in MMP2−/− fibroblasts, whereas exogenous MMP2 was active on both normal and MMP2−/− fibroblasts. Altogether these findings highlight a pivotal role for furin, MT1-MMP, and MMP2 in TNF-α-induced sphingolipid signaling, and they identify this system as a possible target to inhibit SMC proliferation in vascular diseases.


2020 ◽  
Author(s):  
Wenna Gao ◽  
Ruilin Zhu ◽  
liu yang

Background: Mounting evidence has suggested tumor necrosis factor-alpha (TNF-α) can promote the development of diabetic retinopathy (DR), and TNF-α gene variants may influence DR risk. However, the results are quite different. Objectives: To comprehensively address this issue, we performed the meta-analysis to evaluate the association of TNF-α-308 G/A and -238 G/A polymorphism with DR. Method: Data were retrieved in a systematic manner and analyzed using STATA Statistical Software. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations. Allelic and genotypic comparisons between cases and controls were evaluated. Results: For the TNF-α-308 G/A polymorphism, overall analysis suggested a marginal association with DR [the OR(95%CI) of (GA versus GG), (GA + AA) versus GG, and (A versus G) are 1.21(1.04, 1.41), 1.20(1.03, 1.39), and 1.14(1.01, 1.30), respectively]. And the subgroup analysis indicated an enhanced association among the European population. For the TNF-α-238 G/A polymorphism, there was mild correlation in the entire group [the OR(95%CI) of (GA versus GG) is 1.55(1.14,2.11) ], which was strengthened among the Asian population. Conclusion: The meta-analysis suggested that -308 A and -238 A allele in TNF-α gene potentially increased DR risk and showed a discrepancy in different ethnicities.


2016 ◽  
Vol 36 (9) ◽  
pp. 1342-1353 ◽  
Author(s):  
Gil Diamant ◽  
Tal Eisenbaum ◽  
Dena Leshkowitz ◽  
Rivka Dikstein

The proinflammatory cytokine tumor necrosis factor alpha (TNF-α) modulates the expression of many genes, primarily through activation of NF-κB. Here, we examined the global effects of the elongation factor Spt5 on nascent and mature mRNAs of TNF-α-induced cells using chromatin and cytosolic subcellular fractions. We identified several classes of TNF-α-induced genes controlled at the level of transcription, splicing, and chromatin retention. Spt5 was found to facilitate splicing and chromatin release in genes displaying high induction rates. Further analysis revealed striking effects of TNF-α on the splicing of 25% of expressed genes; the vast majority were not transcriptionally induced. Splicing enhancement of noninduced genes by TNF-α was transient and independent of NF-κB. Investigating the underlying basis, we found that Spt5 is required for the splicing facilitation of the noninduced genes. In line with this, Spt5 interacts with Sm core protein splicing factors. Furthermore, following TNF-α treatment, levels of RNA polymerase II (Pol II) but not Spt5 are reduced from the splicing-induced genes, suggesting that these genes become enriched with a Pol II-Spt5 form. Our findings revealed the Pol II-Spt5 complex as a highly competent coordinator of cotranscriptional splicing.


2006 ◽  
Vol 26 (24) ◽  
pp. 9244-9255 ◽  
Author(s):  
Xiaolan Feng ◽  
Shirin Bonni ◽  
Karl Riabowol

ABSTRACT ING proteins affect apoptosis, growth, and DNA repair by transducing stress signals such as DNA damage, binding histones, and subsequently regulating chromatin structure and p53 activity. p53 target genes, including the p21 cyclin-dependent kinase inhibitor and Bax, an inducer of apoptosis, are regulated by ING proteins. To identify additional targets downstream of p33ING1 and p32ING2, cDNA microarrays were performed on phenotypically normal human primary fibroblasts. The 0.36% of genes affected by ING proteins in primary fibroblasts were distinct from targets seen in established cells and included the HSP70 heat shock gene, whose promoter was specifically induced >10-fold. ING1-induced expression of HSP70 shifted cells from survival to a death pathway in response to tumor necrosis factor alpha (TNF-α), and p33ING1b protein showed synergy with TNF-α in inducing apoptosis, which correlated with reduced NF-κB-dependent transcription. These findings are consistent with previous reports that HSP70 promotes TNF-α-mediated apoptosis by binding I-κΒ kinase gamma and impairing NF-κB survival signaling. Induction of HSP70 required the amino terminus of ING1b but not the plant homeodomain region that was recently identified as a histone binding domain. Regulation of HSP70 gene expression by the ING tumor suppressors provides a novel link between the INGs and the stress-regulated NF-κB survival pathway important in hypoxia and angiogenesis.


2001 ◽  
Vol 69 (11) ◽  
pp. 7169-7172 ◽  
Author(s):  
Martin M. Dinges ◽  
Patrick M. Schlievert

ABSTRACT Host susceptibility to lipopolysaccharide (LPS) is correlated with the levels of circulating tumor necrosis factor alpha (TNF-α) that develop in response to circulating LPS. Mice are resistant, relative to rabbits, to the lethal effects of LPS. This study indicates that mice and rabbits are equally sensitive to the lethal effects of circulating TNF-α but that mice are more resistant than rabbits to the induction of circulating TNF-α by LPS.


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