transforming-growth-factor-beta and Coronary-Restenosis

Despite novel surgical therapies for the treatment of atherosclerosis, restenosis continues to be a significant impediment to the long-term success of vascular interventions. Transforming growth factor-beta (TGF-β), a family of cytokines found to be up-regulated at sites of arterial injury, has long been implicated in restenosis; a role that has largely been attributed to TGF-β-mediated vascular fibrosis. However, emerging data indicate that the role of TGF-β in intimal thickening and arterial remodeling, the critical components of restenosis, is complex and multidirectional. Recent advancements have clarified the basic signaling pathway of TGF-β, making evident the need to redefine the precise role of this family of cytokines and its primary signaling pathway, Smad, in restenosis. Unraveling TGF-β signaling in intimal thickening and arterial remodeling will pave the way for a clearer understanding of restenosis and the development of innovative pharmacological therapies.

Topics: Animals; Coronary Restenosis; Disease Models, Animal; Humans; Mice; Mice, Knockout; Signal Transduction; Smad Proteins; Transforming Growth Factor beta; Tunica Intima

Current theories suggest that atherosclerotic and restenotic lesions result from imbalances between systems that are proinflammatory/fibroproliferative versus the endogenous inhibitory systems that normally limit inflammation and vascular wound repair. Abnormalities in one of the major regulatory pathways, the transforming growth factor-beta (TGF-beta) system, has been characterized in both animal models and in human lesions and lesion-derived cells. TGF-beta signaling is capable of regulating many of the key aspects of atherosclerosis and restenosis: inflammation, chemotaxis, fibrosis, proliferation, and apoptosis. There are significant decreases in TGF-beta activity in patients with atherosclerosis, and equally important changes in the way cells respond to TGF-beta during atherogenesis. Evidence from multiple sources indicates that experimental modulation of TGF-beta activity, or TGF-beta responses, changes the course of atherosclerosis and intimal hyperplasia. Cells derived from human lesions produce adequate TGF-beta levels, but are resistant to the antiproliferative and apoptotic effects of TGF-beta. An evolving theory describes TGF-beta as a major orchestrator of the vascular repair process, with observable defects in its production, activation, and cellular responses during the atherosclerotic and restenotic processes.

Topics: Animals; Atherosclerosis; Coronary Restenosis; Disease Models, Animal; Humans; Signal Transduction; Transforming Growth Factor beta

Transforming growth factor-beta (TGF-beta) is the general name for a family of cytokines which have widespread effects on many aspects of growth and development. The TGF-beta isoforms are produced by most cell types and exert a wide range of effects in a context-dependent autocrine, paracrine or endocrine fashion via interactions with distinct receptors on the cell surface. TGF-beta is involved in the wound healing process and, thus plays a significant role in the formation of a restenotic lesion after percutaneous transluminal coronary angioplasty (PTCA) or stenting. Perhaps because of its wide-ranging effects, TGF-beta is usually released from cells in a latent form, and its activation and signaling are complex. Manipulation of the TGF-beta1, TGF-beta2, and TGF-beta3 isoforms by inhibiting their expression, activation, or signaling reduces scarring and fibrosis in animal models. However, to date, few have reached clinical trial. This review summarizes current knowledge on the activation and signaling of TGF-beta, and focuses on the anti-TGF-beta strategies which may lead to clinical applications in the prevention of restenosis following PTCA or stenting.

Topics: Angioplasty, Balloon, Coronary; Animals; Antibodies; Constriction, Pathologic; Coronary Restenosis; Decorin; Drug Delivery Systems; Extracellular Matrix Proteins; In Vitro Techniques; Mannosephosphates; Oligonucleotides, Antisense; Peptide Fragments; Protein Isoforms; Protein Precursors; Proteoglycans; Signal Transduction; Stents; Thrombospondin 1; Transforming Growth Factor beta; Transforming Growth Factor beta1; Wound Healing

To date, there is no periadventitial drug delivery method available in the clinic to prevent restenotic failure of open vascular reconstructions. Resveratrol is a promising anti-restenotic natural drug but subject to low bioavailability when systemically administered. In order to reconcile these two prominent issues, we tested effects of periadventitial delivery of resveratrol on all three major pro-restenotic pathologies including intimal hyperplasia (IH), endothelium impairment, and vessel shrinkage. In a rat carotid injury model, periadventitial delivery of resveratrol either via Pluronic gel (2-week), or polymer sheath (3-month), effectively reduced IH without causing endothelium impairment and vessel shrinkage. In an in vitro model, primary smooth muscle cells (SMCs) were stimulated with elevated transforming growth factor (TGFβ) and its signaling protein Smad3, known contributors to IH. TGFβ/Smad3 up-regulated Kruppel-like factor (KLF5) protein, and SMC de-differentiation which was reversed by KLF5 siRNA. Furthermore, TGFβ/Smad3-stimulated KLF5 production and SMC de-differentiation were blocked by resveratrol via its inhibition of the Akt-mTOR pathway. Concordantly, resveratrol attenuated Akt phosphorylation in injured arteries. Taken together, periadventitial delivery of resveratrol produces durable inhibition of all three pro-restenotic pathologies - a rare feat among existing anti-restenotic methods. Our study suggests a potential anti-restenotic modality of resveratrol application suitable for open surgery.

Topics: Animals; Antioxidants; Cell Differentiation; Cell Proliferation; Cells, Cultured; Coronary Restenosis; Gene Expression Regulation; Male; Muscle, Smooth, Vascular; Phosphorylation; Rats; Rats, Sprague-Dawley; Resveratrol; Signal Transduction; Smad3 Protein; Stilbenes; Transforming Growth Factor beta

Neointima forming after stent implantation consists of vascular smooth muscle cells (VSMCs) in 90%. Growth factors TGF-β1, PDGFB, EGF, bFGF and VEGF-A play an important role in VSMC proliferation and migration to the tunica intima after arterial wall injury. The aim of this paper was an analysis of functional polymorphisms in genes encoding TGF-β1, PDGFB, EGF, bFGF and VEGF-A in relation to in-stent restenosis (ISR).. 265 patients with a stable coronary artery disease (SCAD) hospitalized in our center in the years 2007-2011 were included in the study. All patients underwent stent implantation at admission to the hospital and had another coronary angiography performed due to recurrence of the ailments or a positive result of the test assessing the coronary flow reserve. Angiographically significant ISR was defined as stenosis >50% in the stented coronary artery segment. The patients were divided into two groups-with angiographically significant ISR (n = 53) and without significant ISR (n = 212). Additionally, the assessment of late lumen loss (LLL) in vessel was performed. EGF rs4444903 polymorphism was genotyped using the PCR-RFLP method whilst rs1800470 (TGFB1), rs2285094 (PDGFB) rs308395 (bFGF) and rs699947 (VEGF-A) were determined using the TaqMan method.. Angiographically significant ISR was significantly less frequently observed in the group of patients with the A/A genotype of rs1800470 polymorphism (TGFB1) versus patients with A/G and G/G genotypes. In the multivariable analysis, LLL was significantly lower in patients with the A/A genotype of rs1800470 (TGFB1) versus those with the A/G and G/G genotypes and higher in patients with the A/A genotype of the VEGF-A polymorphism versus the A/C and C/C genotypes. The C/C genotype of rs2285094 (PDGFB) was associated with greater LLL compared to C/T heterozygotes and T/T homozygotes.. The polymorphisms rs1800470, rs2285094 and rs6999447 of the TGFB1, PDGFB and VEGF-A genes, respectively, are associated with LLL in patients with SCAD treated by PCI with a metal stent implantation.

Topics: Aged; Coronary Artery Disease; Coronary Restenosis; Epidermal Growth Factor; Female; Fibroblast Growth Factor 2; Genetic Predisposition to Disease; Humans; Male; Middle Aged; Polymorphism, Single Nucleotide; Proto-Oncogene Proteins c-sis; Stents; Transforming Growth Factor beta; Vascular Endothelial Growth Factor A

The peroxisome proliferator-activated receptor delta (PPARδ) has been implicated in the modulation of vascular homeostasis. However, its roles in the apoptotic cell death of vascular smooth muscle cells (VSMCs) are poorly understood. Here, we demonstrate that PPARδ modulates oxidized low-density lipoprotein (oxLDL)-induced apoptosis of VSMCs through the transforming growth factor-β (TGF-β) and focal adhesion kinase (FAK) signaling pathways. Activation of PPARδ by GW501516, which is a specific ligand, significantly inhibited oxLDL-induced cell death and generation of reactive oxygen species in VSMCs. These inhibitory effects were significantly reversed in the presence of small interfering (si)RNA against PPARδ, or by blockade of the TGF-β or FAK signaling pathways. Furthermore, PPARδ-mediated recovery of FAK phosphorylation suppressed by oxLDL was reversed by SB431542, a specific ALK5 receptor inhibitor, indicating that a TGF-β/FAK signaling axis is involved in the action of PPARδ. Among the protein kinases activated by oxLDL, p38 mitogen-activated protein kinase was suppressed by ligand-activated PPARδ. In addition, oxLDL-induced expression and translocation of pro-apoptotic or anti-apoptotic factors were markedly affected in the presence of GW501516. Those effects were reversed by PPARδ siRNA, or inhibitors of TGF-β or FAK, which also suggests that PPARδ exerts its anti-apoptotic effect via a TGF-β/FAK signaling axis. Taken together, these findings indicate that PPARδ plays an important role in the pathophysiology of disease associated with apoptosis of VSMC, such as atherosclerosis and restanosis.

Topics: Animals; Apoptosis; Atherosclerosis; Cells, Cultured; Coronary Restenosis; Focal Adhesion Protein-Tyrosine Kinases; Lipoproteins, LDL; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; PPAR delta; Rats; RNA, Small Interfering; Signal Transduction; Thiazoles; Transforming Growth Factor beta

Despite advances in stent design, in-stent restenosis (ISR) remains a significant clinical problem. All implant metals exhibit corrosion, which results in release of metal ions. Stainless steel (SS), a metal alloy widely used in stents, releases ions to the vessel wall and induces reactive oxygen species, inflammation and fibroproliferative responses. The molecular mechanisms are unknown. TGF-beta is known to be involved in the fibroproliferative responses of vascular smooth muscle cells (VSMCs) in restenosis, and TGF-beta antagonists attenuate ISR. We hypothesized that SS ions induce the latent TGF-beta activator, thrombospondin-1 (TSP1), through altered oxidative signaling to stimulate increased TGF-beta activation and VSMC phenotype change.. VSMCs were treated with SS metal ion cocktails, and morphology, TSP1, extracellular matrix production, desmin and TGF-beta activity were assessed by immunoblotting.. SS ions stimulate the synthetic phenotype, increased TGF-beta activity, TSP1, increased extracellular matrix and downregulation of desmin in VSMCs. Furthermore, SS ions increase hydrogen peroxide and decrease cGMP-dependent protein kinase (PKG) signaling, a known repressor of TSP1 transcription. Catalase blocks SS ion attenuation of PKG signaling and increased TSP1 expression.. These data suggest that ions from stent alloy corrosion contribute to ISR through stimulation of TSP1-dependent TGF-beta activation.

Topics: Angioplasty, Balloon, Coronary; Animals; Aorta; Catalase; Cell Shape; Cells, Cultured; Coronary Restenosis; Coronary Vessels; Cyclic GMP-Dependent Protein Kinases; Desmin; Extracellular Matrix; Female; Humans; Hydrogen Peroxide; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; Oxidative Stress; Phenotype; Prosthesis Design; Rats; Rats, Sprague-Dawley; Signal Transduction; Stainless Steel; Stents; Thrombospondin 1; Transforming Growth Factor beta

Although emerging data from preclinical and clinical studies suggests a reduction of in-stent restenosis with peroxisome proliferator-activated receptor (PPAR)-gamma agonists, the reduction of neointimal growth via anti-inflammatory mechanisms has not been explored.. Hypercholesterolemic New Zealand White rabbits (n=45) received bilateral balloon-expandable stents implanted into atherosclerotic iliac arteries. Animals were randomized to oral pioglitazone 3 (low dose) or 10 mg/kg per day (high dose) started on the day of stent implantation; control rabbits received placebo. Tissue harvest was performed 28 days after stenting, and stented segments underwent histology, morphometry, immunostaining for macrophages, and scanning electron microscopy. In selected animals, stented arterial segments were placed in organoid culture for 48 hours, and the conditioned media was assayed for 23 different cytokines. There was a 21% reduction in neointimal area for high-dose pioglitazone treated versus placebo rabbits (P<0.005), which was associated with a significant reduction of neointimal macrophages. Analysis of conditioned media revealed an 82% and 74% reduction in the release of monocyte chemoattractant protein-1 (MCP-1) (P<0.007) and transforming growth factor (TGF)-beta1 (P<0.01), respectively, in stented segments from animals treated with 10 mg/kg per day pioglitazone versus placebo.. Oral pioglitazone suppresses in-stent neointimal growth by limiting local inflammatory pathways and may be useful as an adjunctive therapy in patients undergoing percutaneous interventions.

Topics: Administration, Oral; Animals; Atherosclerosis; Cell Proliferation; Cells, Cultured; Chemokine CCL2; Coronary Restenosis; Dose-Response Relationship, Drug; Gene Expression Regulation; Hypoglycemic Agents; Macrophages; Mice; Organ Culture Techniques; Pioglitazone; Rabbits; Random Allocation; Stents; Thiazolidinediones; Transforming Growth Factor beta; Tunica Intima

Enhanced extracellular matrix accumulation rather than cell proliferation contributes to later stages of in-stent restenosis. Aldosterone itself has been shown to increase cardiovascular fibrosis, therefore, we studied the suppressive effects of eplerenone, a new aldosterone receptor antagonist, on neointimal hyperplasia after coronary stent implantation in swine.. Palmatz-Shatz stents were implanted in the left anterior descending artery of 36 pigs. One hundred milligrams of Eplerenone was orally administered from 1 week before, to 4 weeks after stent implantation in Group E (n=18), and vehicle was given to Group C (n=18). Pigs were sacrificed 1 or 4 weeks after stent implantation. The number of infiltrating macrophages was calculated at 1 week. Morphometrical analysis was performed to measure the area of each layer, and %area of fibrosis and mRNA for collagen I, III and TGF-beta was analyzed by RT-PCR at 4 weeks.. The number of infiltrating macrophages was less in Group E than in Group C (p<0.01). The overall size of coronary arteries at 4 weeks was similar in both groups. However, the luminal area was larger in Group E than in Group C (p<0.05), and the intimal area was smaller in Group E than in Group C (p<0.05). The %area of fibrosis was significantly less in Group E than in Group C at 4 weeks (p<0.01). In Group E, the expression of mRNA for collagen I, III and TGF-beta was significantly reduced.. Orally administered eplerenone attenuated collagen accumulation within the neointima, thereby inhibiting neointimal hyperplasia after stent implantation.

Topics: Actins; Administration, Oral; Animals; Blood Vessel Prosthesis Implantation; Collagen Type I; Collagen Type III; Coronary Restenosis; Coronary Vessels; Disease Models, Animal; Eplerenone; Fibrosis; Hyperplasia; Immunohistochemistry; Macrophages; Male; Mineralocorticoid Receptor Antagonists; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Spironolactone; Stents; Swine; Time Factors; Transforming Growth Factor beta; Tunica Intima

Thrombospondin-1 (TSP-1) and transforming growth factor-beta1 (TGF-beta1) are both implicated in the pathogenesis of in-stent restenosis. This study evaluated the hypothesis that the HMG-CoA reductase inhibitor fluvastatin inhibits TGF-beta1 induced TSP-1 expression via inhibition of p38 mitogen activated protein kinase (MAPK) phosphorylation in human coronary artery smooth muscle cells (HCASMC) and may therefore have anti-restenosis potential. Fluvastatin significantly reduced TSP-1 mRNA and protein expression in HCASMC in a concentration-dependent manner with a significant reduction in expression observed after treatment with 0.25 microM fluvastatin. TGF-beta1 (5 ng/ml) induced phosphorylation of p38 MAPK and induced TSP-1 mRNA and protein expression in HCASMC. Fluvastatin abolished TGF-beta1-induced phosphorylation of p38 MAPK and TGF-beta1-induced TSP-1 expression. Blockade of the p38 MAPK pathway with the upstream inhibitor SB-203580 also abolished TGF-beta1-induced TSP-1 expression. We conclude that fluvastatin decreases expression of TSP-1 and abolishes the ability of TGF-beta1 to induce TSP-1 expression in HCASMC; this may be achieved by preventing signalling through the p38 MAPK pathway. Targeted delivery of fluvastatin may therefore be a useful therapeutic objective for prevention of the intimal hyperplasia associated with in-stent restenosis.

Topics: Adult; Cells, Cultured; Coronary Restenosis; Coronary Vessels; Dose-Response Relationship, Drug; Enzyme Inhibitors; Fatty Acids, Monounsaturated; Fluvastatin; Gene Expression Regulation; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Imidazoles; Indoles; Male; MAP Kinase Signaling System; Muscle, Smooth, Vascular; Myocytes, Smooth Muscle; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Pyridines; RNA, Messenger; Thrombospondin 1; Transforming Growth Factor beta; Transforming Growth Factor beta1

Concentrations of interleukins 6 and 10, tumor necrosis factor alpha, transforming growth factor beta and C-reactive protein were measured in 42 patients before and in remote period after coronary stenting. Patients with angiographically documented in-stent restenosis compared with those without restenosis had higher initial levels of interleukin 6 and more often discontinued therapy with statins.

Topics: Aged; Biomarkers; C-Reactive Protein; Chronic Disease; Coronary Angiography; Coronary Restenosis; Coronary Vessels; Female; Humans; Interleukin-10; Interleukin-6; Male; Middle Aged; Myocardial Ischemia; Stents; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Vasculitis

Diabetes and renal failure have been associated with extremely high restenosis rates following successful angioplasty, resulting in increased morbidity and mortality. Advanced glycosylation end products (AGEs) accumulate in vascular tissues with aging and at an accelerated rate in diabetes and renal failure. AGEs are particularly abundant at sites of atherosclerotic lesions. AGEs interact with specific receptors (RAGE) present on all cells relevant to the restenosis process including inflammatory cells and smooth muscle cells. AGEs-RAGE interaction in vessel wall may lead to inflammation, smooth muscle cell proliferation, and extracellular matrix production, culminating in exaggerated intimal hyperplasia and restenosis. Following arterial injury, the interaction of AGEs with monocytes expressing RAGE can promote migration of inflammatory cells into the lesion and subsequent release of growth factors and cytokines. Binding of AGEs-RAGE on smooth muscle cells increases chemotactic migration and cellular proliferation. AGEs trigger the generation of reactive oxygen species, and upregulate the multifunctional transcription factor NF-kappa B. Finally, AGEs can augment extracellular matrix production by upregulating transforming growth factor-beta. Thus, accumulation of AGEs in vessel wall provides a common mechanism for the high restenosis rates of patients with diabetes and renal failure.

Topics: Angioplasty, Balloon, Coronary; Coronary Disease; Coronary Restenosis; Cytokines; Diabetic Angiopathies; Diabetic Nephropathies; Extracellular Matrix; Glycation End Products, Advanced; Growth Substances; Humans; Hyperplasia; Kidney Failure, Chronic; Models, Biological; Muscle, Smooth, Vascular; NF-kappa B; Receptor for Advanced Glycation End Products; Receptors, Immunologic; Stents; Transforming Growth Factor beta; Tunica Intima; Tunica Media

N(3,4-dimethoxycinnamoyl) anthranilic acid (tranilast) prevents the synchronous upregulation of isoforms and receptors of the transforming growth factor (TGF)-beta system after arterial injury and reduces restenosis after human coronary angioplasty. However, the effects of tranilast and the importance of the TGF-beta system in stent restenosis, in which inward remodeling is unimportant but inflammatory cell stimulation of neointima formation is exaggerated, are uncertain. Boston minipigs, treated with tranilast or vehicle, were subjected to endoluminal stenting, and the expression of TGF-beta1 and TGF-beta3, the expression of their signaling receptors ALK-5 and TbetaR-II, leukocyte numbers around the stent struts, and neointima development were assessed over 28 days. Stenting greatly increased early (5-day) mRNA expression of the 2 TGF-beta isoforms and their receptors. Immunohistochemical localization later showed that their concentrations were greatest in regions adjacent to stent struts, where leukocytes and collagen deposition were prevalent. Tranilast suppressed these elevations in TGF-beta mRNAs and reduced their immunoreactive peptides detectable around stent struts. The accumulation of leukocytes and deposition of collagen in these regions was also greatly inhibited by tranilast. These effects were associated with a 48% reduction in maximal neointimal cross-sectional area and 43% reduction in mean neointimal cross-sectional area at 28 days (P<0.05). We conclude that tranilast suppresses neointima development after stenting, effects that can be at least partly attributed to its ability to attenuate the induction of the TGF-beta system and leukocyte accumulation around stent struts.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Coronary Restenosis; Coronary Vessels; Drug Administration Schedule; Hyperplasia; Inflammation; Leukocytosis; Male; ortho-Aminobenzoates; Stents; Swine; Transforming Growth Factor beta; Tunica Intima; Up-Regulation

Extracellular matrix (ECM) remodeling is central to the development of restenosis after coronary angioplasty (PTCA). As a regulator of ECM deposition by vascular cells, substantial evidence implicates transforming growth factor-beta1 (TGF-beta1) in the pathogenesis of restenosis. We investigated the effects of intracoronary expression of a transgenic antagonist of TGF-beta1 on luminal loss after PTCA.. Porcine coronary arteries were randomized to receive a recombinant adenovirus expressing a secreted form of TGF-beta type II receptor (Ad5-RIIs), an adenovirus expressing beta-galactosidase (Ad5-lacZ), or vehicle only by intramural injection at the site of PTCA. Computerized morphometry 28 days after angioplasty revealed a greater minimum luminal area in Ad5-RIIs-injected arteries (1.71+/-0.12 mm(2)) than in the Ad5-lacZ (1.33+/-0.13 mm(2)) or vehicle-only (1.08+/-0.17 mm(2); P=0.010 by ANOVA) groups. This was accompanied by greater areas within the internal (P=0.013) and external (P=0.031) elastic laminae in Ad5-RIIs-treated vessels. Adventitial collagen content at the site of injury was increased in the Ad5-RIIs group, in contrast to decreases in the Ad5-lacZ and vehicle-only groups (P=0.004).. Adenovirus-mediated antagonism of TGF-beta1 at the site of PTCA reduces luminal loss after PTCA by inhibiting constrictive remodeling. Antagonism of TGF-beta1 stimulates the formation of a dense collagenous adventitia, which prevents constrictive remodeling by acting as an external scaffold. These findings demonstrate the potential of gene therapy-mediated antagonism of TGF-beta1 as prophylactic therapy for restenosis.

Topics: Adenoviridae; Angioplasty, Balloon, Coronary; Animals; beta-Galactosidase; Cells, Cultured; Collagen; Constriction, Pathologic; Coronary Restenosis; Coronary Vessels; Culture Media, Conditioned; Genetic Therapy; Genetic Vectors; Inflammation; Muscle, Smooth, Vascular; Protein Serine-Threonine Kinases; Receptor, Transforming Growth Factor-beta Type II; Receptors, Transforming Growth Factor beta; RNA, Messenger; Swine; Transforming Growth Factor beta; Transforming Growth Factor beta1