u-0126 and Hyperplasia

Early neointimal hyperplasia of vein graft may be ameliorated via enhancing intravenous surface shear stress. Cellular processes including proliferation, apoptosis and migration of endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) may play very important roles in the process of neointimal hyperplasia of vein graft; and mitogen-activated protein kinase (MAPK) pathways including extracellular signal-regulated kinase (ERK1/2) and p38 pathways play vital roles in regulating a large variety of cellular processes. This study evaluated the impacts of shear stress and MAPK pathways on cellular processes of ECs in a co-culture system with VSMCs, and aimed to test the hypothesis that high shear stress suppresses proliferation and migration but promotes apoptosis of ECs co-cultured with VSMCs via down-regulating MAPK pathway.. Primary ECs and VSMCs derived from porcine great saphenous vein were collected, respectively. 4-7 generation of cells were used as work cells. ECs and VSMCs were co-cultured and synchronized under high and low shear stress using Parallel-Plate Flow Chamber system. And then, ECs co-cultured with VSMCs were incubated with U0126 (ERK1/2 inhibitor) or PD98059 (p38 inhibitor) under different shear stress. Proliferation, apoptosis and migration of ECs in a co-culture system with VSMCs were detected by 4,5-dimethyl-2-thiazolyl (MTT) assay and bromodeoxyuridine (BrdU) assay, fluorescent-activated cell sorting (FACS) technique, and Transwell assay separately. Each test repeated 3 times. Additionally, protein expressions of ERK1/2 and p38 MAPK were detected by using Western blot, respectively.. Under higher level of shear stress condition, proliferation and migration of ECs co-cultured with VSMCs were suppressed, while cell apoptosis was promoted. And blocking ERK1/2 pathway by U0126 or blocking p38 pathway by PD98059, proliferation and migration of ECs co-cultured with VSMCs were further suppressed, while cell apoptosis was further promoted. Additionally, protein expressions of phosphorylation of ERK1/2 and p38MAPK were decreased under higher level of shear stress condition, and were further reduced by blocking ERK1/2 or p38 pathway under shear stress condition.. High shear stress may suppress proliferation and apoptosis of ECs in a co-culture system with VSMCs but promote cell migration via down-regulating ERK1/2 and p38 MAPK pathways.

Topics: Animals; Apoptosis; Butadienes; Cell Movement; Cell Proliferation; Cells, Cultured; Coculture Techniques; Down-Regulation; Endothelial Cells; Hyperplasia; MAP Kinase Signaling System; Models, Animal; Muscle, Smooth, Vascular; Nitriles; Saphenous Vein; Shear Strength; Swine; Transplants

Runx3 is essential for normal vertebrate lung development and Runx3 knockout (KO) mice die within 24 h after birth because of various organ defects including defects in alveolar expansion. For proper early lung development, vasculogenesis and angiogenesis are necessary in humans. Previous studies have reported that various signaling molecules, such as CD31, VEGF and vWF, are closely related to lung vasculogenesis and angiogenesis. To confirm the relationship between Runx3-related lung defects and vasculogenesis, the localization of various blood vessel markers is examined in WT and Runx3 KO mouse lungs at PN1. Our results indicate that CD31, VEGF and vWF were dramatically up-regulated by a loss of Runx3 during lung development. Moreover, U0126, a MEK inhibitor, rescued the lung phenotype and vascularization by regulation of ERK signaling. Therefore, it was concluded that lung vasculogenesis and angiogenesis were induced in the Runx3 KO mouse, which shows lung defects, by increased CD31, VEGF and vWF.

Topics: Animals; Butadienes; Core Binding Factor Alpha 3 Subunit; Enzyme Inhibitors; Extracellular Signal-Regulated MAP Kinases; Hyperplasia; Lung; Mice; Mice, Inbred C57BL; Mice, Knockout; Mitogen-Activated Protein Kinase Kinases; Neovascularization, Physiologic; Nitriles; Platelet Endothelial Cell Adhesion Molecule-1; Vascular Endothelial Growth Factor A; von Willebrand Factor

Lung cancer is the leading cause of cancer-related mortality worldwide. Early detection or prevention strategies are urgently needed to increase survival. Hyperplasia is the first morphologic change that occurs in the bronchial epithelium during lung cancer development, followed by squamous metaplasia, dysplasia, carcinoma in situ, and invasive tumor. This study was designed to determine the molecular mechanisms that control bronchial epithelium hyperplasia. Using primary normal human tracheobronchial epithelial (NHTBE) cells cultured by using the 3-dimensional (3D) organotypic method, we found that the epidermal growth factor receptor (EGFR) ligands, EGF, TGF-α, and amphiregulin induced hyperplasia, as determined by cell proliferation and multilayered epithelium formation. We also found that EGF induced increased cyclin D1 expression, which plays a critical role in bronchial hyperplasia; this overexpression was mediated by activating the mitogen-activated protein kinase pathway but not the phosphoinositide 3-kinase/Akt signaling pathway. Erlotinib, an EGFR tyrosine kinase inhibitor, and U0126, a MAP/ERK kinase (MEK) inhibitor, completely inhibited EGF-induced hyperplasia. Furthermore, a promoter analysis revealed that the activator protein-1 transcription factor regulates EGF-induced cyclin D1 overexpression. Activator protein-1 depletion by using siRNA targeting its c-Jun component completely abrogated EGF-induced cyclin D1 expression. In conclusion, we showed that bronchial hyperplasia can be modeled in vitro by using primary NHTBE cells maintained in a 3D organotypic culture. EGFR and MEK inhibitors completely blocked EGF-induced bronchial hyperplasia, suggesting that they have a chemopreventive role.

Topics: Bronchi; Butadienes; Cell Line, Tumor; Cyclin D1; Enzyme Inhibitors; ErbB Receptors; Erlotinib Hydrochloride; Humans; Hyperplasia; Luciferases; Lung Neoplasms; MAP Kinase Kinase Kinases; Models, Biological; Nitriles; Organ Culture Techniques; Quinazolines; RNA, Small Interfering

Tumor cells that are grown in three-dimensional (3D) cell culture exhibit relative resistance to cytotoxic drugs compared with their response in conventional two-dimensional (2D) culture. We studied the effects of targeted agents and doxorubicin on 2D and 3D cultures of human breast cell lines that represent the progression from normal epithelia (modeled by MCF10A cells) through hyperplastic variants to a dysplastic/carcinoma phenotype (MCF10.DCIS cells), variants transformed by expression of activated Ras, and also a basal-subtype breast carcinoma cell line (MDA-MB-231). The results showed the expected relative resistance to the cytotoxic agent doxorubicin in 3D cultures, with greater resistance in normal and hyperplastic cells than in carcinoma models. However, the response to the targeted inhibitors was more complex. Inhibition of mitogen-activated protein kinase kinase (MEK) by either 1,4-diamino-2,3-dicyano-1,4-bis(methylthio)butadiene (U0126) or 2-(2-chloro-4-iodo-phenylamino)-N-cyclopropylmethoxy-3,4-difluoro-benzamide (CI-1040, PD184352) produced a similar inhibition of the growth of all the MCF10 cell lines in 2D. In 3D culture, the normal and hyperplastic models exhibited some resistance, whereas the carcinoma models became far more sensitive to MEK inhibition. Increased sensitivity to MEK inhibition was also seen in MDA-MB-231 cells grown in 3D compared with 2D. In contrast, inhibition of phosphatidylinositol 3'-kinase activity by wortmannin had no significant effect on the growth of any of the cells in either 2D or 3D. Our conclusion is that 3D culture models may not only model the relative resistance of tumor cells to cytotoxic therapy but also that the 3D approach may better identify the driving oncogenic pathways and critical targeted inhibitors that may be effective treatment approaches.

Topics: Androstadienes; Antineoplastic Agents; Benzamides; Breast Neoplasms; Butadienes; Cell Culture Techniques; Cell Line; Cell Line, Transformed; Cell Line, Tumor; Cell Proliferation; Doxorubicin; Drug Resistance, Neoplasm; Female; Genes, ras; Humans; Hyperplasia; Mammary Glands, Human; Mitogen-Activated Protein Kinase Kinases; Nitriles; Phosphoinositide-3 Kinase Inhibitors; Wortmannin

Vein graft arterialization results in activation of the mitogen-activated protein kinases (MAPKs) extracellular signal-regulated kinases-1 and -2 (ERK1/2), which have been implicated in cell proliferation, migration, and apoptosis. The goal of our study was to characterize the effect of MAPK inhibition on intimal hyperplasia (IH) in arterialized vein grafts in hypercholesterolemic rabbits.. Reversed bilateral jugular vein to common carotid artery interposition grafts were constructed in 16 New Zealand White rabbits. The veins were incubated for 30 min prior to grafting with either the synthetic ERK1/2 activation inhibitor UO126 or the control vehicle. Vein graft and control jugular vein were harvested 3 h, 1 d, and 28 d after arterialization for histological and biochemical analyses.. Treatment with UO126 was associated with 31% reduction in mean intimal area (1.68 +/- 0.78 mm(2)versus 2.44 +/- 1.65 mm(2); mean +/- SD; P = 0.036) relative to controls. The intima-to-media ratio of UO126-treated vein grafts decreased by 29% (0.53 +/- 0.04 versus 0.74 +/- 0.06; mean +/- SD; P < 0.01) compared to controls, vehicle-treated vein grafts. There was also significant increase in apoptosis in UO126-treated vein graft medial cell layer at 1 d.. Topical administration of UO126 before vein grafting significantly decreases IH in arterialized vein grafts in hypercholesterolemic rabbits. These results may have significant implications for the development of strategies aimed at blocking or reducing IH in bypass grafts. Therefore, further evaluation of this simple strategy to improve vein graft patency following coronary artery or peripheral vascular bypass surgery is warranted.

Topics: Animals; Apoptosis; Butadienes; Carotid Arteries; Carotid Artery, Common; Cell Division; Enzyme Activation; Enzyme Inhibitors; Hyperplasia; Jugular Veins; Mitogen-Activated Protein Kinases; Nitriles; Rabbits; Tunica Intima

Increase in the expression of leukocyte antigen-related (LAR) protein causes insulin resistance, an important contributor to atherosclerosis. However, the function of LAR in atherosclerosis is not known. To address whether LAR is important in the response of vascular cells to atherogenic stimuli, we investigated cell proliferation, migration, and insulin-like growth factor-1 receptor (IGF-1R) signaling in wild-type and LAR(-/-) mouse vascular smooth muscle cells (VSMC) treated with IGF-1. Absence of LAR significantly enhanced proliferation and migration of VSMC compared with wild-type cells after IGF-1 treatment. U0126 and LY249002, specific inhibitors of MAPK/ERK kinase (MEK) and phosphoinositide 3-kinase, respectively, inhibited IGF-1-induced DNA synthesis and migration in both wild-type and LAR(-/-) VSMC. IGF-1 markedly enhanced IGF-1R phosphorylation in both wild-type and LAR(-/-) VSMC, but the phosphorylation was 90% higher in knock-out cells compared with wild-type cells. Absence of LAR enhanced phosphorylation of insulin receptor substrate-1 and insulin receptor substrate-1-associated phosphoinositide 3-kinase activity in VSMC treated with IGF-1. IGF-1-induced phosphorylation of ERK1/2 also increased significantly in LAR(-/-) VSMC compared with wild-type cells. Furthermore, LAR directly binds to IGF-1R in glutathione S-transferase-LAR pull-down and IGF-1R immunoprecipitation experiments and recombinant LAR dephosphorylates IGF-1R in vitro. Neointima formation in response to arterial injury and IGF-1R phosphorylation in neointima increased significantly in LAR(-/-) mice compared with wild-type mice. A significant decrease in body weight, fasting insulin, and IGF-1 levels were observed in LAR(-/-) mice compared with wild-type mice. Together, these data indicate that LAR regulates IGF-1R signaling in VSMC and dysregulation of this phosphatase may lead to VSMC hyperplasia.

Topics: Animals; Arteries; Atherosclerosis; Butadienes; Cell Movement; Cell Proliferation; Cells, Cultured; Enzyme Inhibitors; Humans; Hyperplasia; Insulin Resistance; Insulin-Like Growth Factor I; Male; MAP Kinase Kinase Kinases; MAP Kinase Signaling System; Mice; Mice, Knockout; Nitriles; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Protein Binding; Protein Processing, Post-Translational; Protein Tyrosine Phosphatase, Non-Receptor Type 1; Protein Tyrosine Phosphatases; Receptor-Like Protein Tyrosine Phosphatases, Class 4; Receptor, IGF Type 1; Receptors, Cell Surface; Tunica Media

Hyperplasia of middle-ear mucosa (MEM) during otitis media (OM) is thought to be partially mediated by the actions of growth factors and their receptors. The intracellular pathway leading from the small G-protein Ras to the extracellular regulated kinases (Erks) often links growth factor stimulation to cellular proliferation. This study assessed whether this pathway is involved in MEM hyperplasia during bacterial OM via the activation of Erk1/Erk2 in MEM of an in vivo rat bacterial OM model. Activation was maximal at 1 and 6 h and at 1 week after introduction of bacteria into the middle ear. Additionally, an in vitro model of rat MEM in bacterial OM was treated with farnesyl transferase inhibitor 277 or the Mek inhibitor U0126. MEM explants treated with either inhibitor demonstrated significant suppression of bacterially induced growth. These data support a role for Ras and Erk signaling in MEM hyperplasia during bacterial OM.

Topics: Animals; Butadienes; Disease Models, Animal; Ear, Middle; Enzyme Inhibitors; Haemophilus Infections; Haemophilus influenzae; Hyperplasia; In Vitro Techniques; Male; Methionine; Mitogen-Activated Protein Kinases; Mucous Membrane; Nitriles; Otitis Media; ras Proteins; Rats; Signal Transduction; Time Factors