cyclin-d1 and Cardiovascular-Diseases

Resveratrol (trans-3,4',5-trihydroxystibene) is a phytopolyphenol isolated from the seeds and skins of grapes. Recent studies indicate that resveratrol can block the process of multistep carcinogenesis, namely, tumor initiation, promotion and progression. Resveratrol can also reduce the risk of cardiovascular disease in man. The molecular mechanisms of resveratrol in chemoprevention of cancer and cardiovascular disease are interesting and under intensive investigation. Resveratrol was found to strongly inhibit nitric oxide (NO) generation in activated macrophages, as measured by the amount of nitrite released into the culture medium, and resveratrol strongly reduced the amount of cytosolic inducible nitric oxide synthase (iNOS) protein. The activation of nuclear factor kappa B (NF kappa B) induced by lipopolysaccharide (LPS) was inhibited by resveratrol. The phosphorylation and degradation of nuclear factor inhibitor kappa B alpha (I kappa B alpha) were inhibited by resveratrol simultaneously. Reactive oxygen species (ROS) are regarded as having carcinogenic potential and have been associated with tumor promotion. Resveratrol may act as a reactive oxygen species scavenger to suppress tumor development. In addition, resveratrol may block multistep carcinogenesis through mitotic signal transduction blockade. Reactive oxygen species are pivotal factors in the genesis of heart disease. Meanwhile, efficient endogenous antioxidants, including superoxide dismutase (SOD), glutathione peroxidase (GSHPx), and catalase, are present in tissues. A fine balance between reactive oxygen species and endogenous antioxidants is believed to exist. Any disturbance of this balance in favor of reactive oxygen species causes an increase in oxidative stress and initiates subcellular changes, leading to cardiomyopathy and heart failure. The experimental results indicate that exogenous antioxidant resveratrol is of value in chemopreventing the development of heart disease. It is urgent that more efforts be made to investigate newer therapies employing antioxidants for the chemoprevention of cardiovascular disease and cancer.

Topics: Anticarcinogenic Agents; Carcinogens; Cardiovascular Diseases; Cell Cycle; Cyclin D1; Enzyme Inhibitors; Gene Expression Regulation; Growth Substances; Humans; Lipid Peroxidation; Neoplasms; NF-kappa B; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Oxidative Stress; Phosphorylation; Protein Processing, Post-Translational; Reactive Oxygen Species; Receptor Protein-Tyrosine Kinases; Resveratrol; Risk Factors; Rosales; Signal Transduction; Stilbenes; Transcription, Genetic; Wine

An increasing number of studies have focus upon β-adrenergic receptor blockers and their anti-tumor effects. However, the use of Carvedilol (CVD), the third generation β-AR blocker, has not been explored for use against T-ALL. In this study, the level of β-ARs was explored in pediatric T-ALL patients. Moreover, the antitumor effects of CVD against T-ALL were assessed in vitro and in vivo, and the underlying mechanisms were investigated. The viability of T-ALL cells following CVD treatment was detected using a CCK-8 assay, and the apoptotic and cell cycle effects were measured using flow cytometry. The protein levels of β-ARs, cAMP, Epac, JAK2, STAT3, p-STAT3, PI3K, p-PI3K, AKT, p-AKT, mTOR, cyclin D1, PCNA, and cleaved caspase-3 were assessed by Western blotting. In vivo experiments were used to investigate the effect of CVD on T-ALL growth in mice. The results indicated that β-ARs were highly expressed in the newly diagnosed T-ALL cells when compared to those in the control group (P < 0.05). In vitro, CVD significantly inhibited T-ALL cell viability, promoted apoptosis and blocked the G0/G1 phase of cell cycle. After CVD treatment, the protein levels of β-ARs, cAMP, Epac, PI3K, p-PI3K, AKT, p-AKT, mTOR, JAK2, STAT3, p-STAT3, cyclin D1 and PCNA were significantly downregulated (P < 0.05); whereas cleaved caspase-3 was significantly upregulated (P < 0.05). In vivo, the volume and weight of the xenograft tumors were significantly decreased in the CVD group (P < 0.05). CVD promoted xenograft tumor apoptosis and reduced the proportion of CEM-C1 cells in murine peripheral blood and bone marrow (P < 0.05). Our results demonstrate that β-ARs are expressed in T-ALL. CVD has a strong antitumor effect against T-ALL and inhibits β-AR associated signaling pathways. Therefore, CVD may provide a potential therapy for T-ALL.

Topics: Animals; Apoptosis; Cardiovascular Diseases; Carvedilol; Caspase 3; Cell Line, Tumor; Cell Proliferation; Cyclin D1; Guanine Nucleotide Exchange Factors; Humans; Mice; Phosphatidylinositol 3-Kinases; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma; Proliferating Cell Nuclear Antigen; Proto-Oncogene Proteins c-akt; Signal Transduction; TOR Serine-Threonine Kinases

Adult hearts respond to increased workload such as prolonged stress or injury, by undergoing hypertrophic growth. During this process, the early adaptive responses are important for maintaining cardiac output whereas at later stages, pathological responses such as cardiomyocyte apoptosis and fibrosis cause adverse remodelling, that can progress to heart failure. Yet the factors that control transition from adaptive responses to pathological remodelling in the heart are not well understood. Here we describe the POU4F2/Brn-3b transcription factor (TF) as a novel regulator of adaptive hypertrophic responses in adult hearts since Brn-3b mRNA and protein are increased in angiotensin-II (AngII) treated mouse hearts with concomitant hypertrophic changes [increased heart weight:body weight (HW:BW) ratio]. These effects occur specifically in cardiomyocytes because Brn-3b expression is increased in AngII-treated primary cultures of neonatal rat ventricular myocytes (NRVM) or foetal heart-derived H9c2 cells, which undergo characteristic sarcomeric re-organisation seen in hypertrophic myocytes and express hypertrophic markers, ANP/βMHC. The Brn-3b promoter is activated by known hypertrophic signalling pathways e.g. p42/p44 mitogen-activated protein kinase (MAPK/ERK1/2) or calcineurin (via NFAT). Brn-3b target genes, e.g. cyclin D1, GLUT4 and Bax, are increased at different stages following AngII treatment, supporting distinct roles in cardiac responses to stress. Furthermore, hearts from male Brn-3b KO mutant mice display contractile dysfunction at baseline but also attenuated hypertrophic responses to AngII treatment. Hearts from AngII-treated male Brn-3b KO mice develop further contractile dysfunction linked to extensive fibrosis/remodelling. Moreover, known Brn-3b target genes, e.g. GLUT4, are reduced in AngII-treated Brn-3b KO hearts, suggesting that Brn-3b and its target genes are important in driving adaptive hypertrophic responses in stressed heart.

Topics: Angiotensin II; Animals; Animals, Newborn; Apoptosis; bcl-2-Associated X Protein; Calcineurin; Cardiovascular Diseases; Cyclin D1; Gene Expression Regulation; Glucose Transporter Type 4; Humans; Hypertrophy; Mice; Mice, Knockout; Myocardium; Myocytes, Cardiac; Primary Cell Culture; Rats; RNA, Small Interfering; Transcription Factor Brn-3B

We previously reported that high levels of tissue factor (TF) can induce cellular apoptosis in endothelial cells. In this study, TF-mediated mechanisms of induction of apoptosis were explored. Endothelial cells were transfected to express wild-type TF. Additionally, cells were transfected to express Asp253-substituted, or Ala253-substitued TF to enhance or prevent TF release, respectively. Alternatively, cells were pre-incubated with TF-rich and TF-poor microvesicles. Cell proliferation, apoptosis and the expression of cyclin D1, p53, bax and p21 were measured following activation of cells with PAR2-agonist peptide. Greatest levels of cell proliferation and cyclin D1 expression were observed in cells expressing wild-type or Asp253-substituted TF. In contrast, increased cellular apoptosis was observed in cells expressing Ala253-substituted TF, or cells pre-incubated with TF-rich microvesicles. The level of p53 protein, p53-phosphorylation at ser33, p53 nuclear localisation and transcriptional activity, but not p53 mRNA, were increased in cells expressing wild-type and Ala253-substituted TF, or in cells pre-incubated with TF-rich microvesicles. However, the expression of bax and p21 mRNA, and Bax protein were only increased in cells pre-incubated with TF-rich microvesicle and in cells expressing Ala253-substituted TF. Inhibition of the transcriptional activity of p53 using pifithrin-α suppressed the expression of Bax. Finally, siRNA-mediated suppression of p38α, or inhibition using SB202190 significantly reduced the p53 protein levels, p53 nuclear localisation and transcriptional activity, suppressed Bax expression and prevented cellular apoptosis. In conclusion, accumulation of TF within endothelial cells, or sequestered from the surrounding can induce cellular apoptosis through mechanisms mediated by p38, and involves the stabilisation of p53.

Topics: Amino Acid Substitution; Apoptosis; bcl-2-Associated X Protein; Breast Neoplasms; Cardiovascular Diseases; Cell Line, Tumor; Cell-Derived Microparticles; Cells, Cultured; Coronary Vessels; Cyclin D1; Endothelial Cells; Enzyme Activation; Female; Gene Expression Regulation; Genes, Reporter; Humans; Imidazoles; MAP Kinase Signaling System; Oligopeptides; p38 Mitogen-Activated Protein Kinases; Pyridines; Recombinant Fusion Proteins; RNA Interference; RNA, Messenger; RNA, Small Interfering; Thromboplastin; Transfection; Tumor Suppressor Protein p53

Proliferation of vascular smooth muscle cells (VSMCs) contributes to the development of atherosclerosis. Ezetimibe is a new lipid lowering agent that inhibits cholesterol absorption. In the present study we attempted to investigate whether ezetimibe has any effect on VSMC proliferation and the potential mechanisms involved. Our data showed ezetimibe abrogated the proliferation and migration of primary rat VSMCs induced by Chol:MβCD. Mechanically, we found that ezetimibe was capable of abolishing cyclin D1, CDK2, phospho-Rb (p-Rb), and E2F protein expressions that were upregulated by Chol:MβCD treatment. In addition, Ezetimibe was able to reverse cell cycle progression induced by Chol:MβCD, which was further supported by its down-regulation of cyclin D1 promoter activity in the presence of Chol:MβCD. Furthermore, ezetimibe abrogated the increment of phospho-ERK1/2 (p-ERK1/2) and nuclear accumulation of ERK1/2 in VSMCs induced by Chol:MβCD. Inhibition of the MAPK pathway by using ERK1/2 inhibitor PD98059 attenuated the reduction effect of ezetimibe on the expressions of phosphor-MEK1 (p-MEK1), p-ERK1/2, and cyclin D1. Taken together our data suggest that ezetimibe inhibits Chol:MβCD-induced VSMCs proliferation and leads to cell cycle arrest at the G0/G1 phase by suppressing cyclin D1 expression via the MAPK signaling pathway. These novel findings support the potential pleiotropic effect of ezetimibe in cardiovascular disease.

Topics: Animals; Anticholesteremic Agents; Azetidines; Cardiovascular Diseases; Cell Cycle Checkpoints; Cell Movement; Cell Proliferation; Cells, Cultured; Cyclin D1; Depression, Chemical; Ezetimibe; Male; MAP Kinase Signaling System; Molecular Targeted Therapy; Muscle, Smooth, Vascular; Rats, Sprague-Dawley; Up-Regulation