scholarly journals Flavin Oxidase-Induced ROS Generation Modulates PKC Biphasic Effect of Resveratrol on Endothelial Cell Survival

Biomolecules ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 209 ◽  
Author(s):  
Anna Maria Posadino ◽  
Roberta Giordo ◽  
Annalisa Cossu ◽  
Gheyath K. Nasrallah ◽  
Abdullah Shaito ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Death ◽  
Dna Synthesis ◽  
Cell Survival ◽  
Cellular Response ◽  
Cell Cycle Progression ◽  
Natural Antioxidants ◽  
Cycle Progression ◽  
Protein Levels ◽  
The Impact

Background: Dietary intake of natural antioxidants is thought to impart protection against oxidative-associated cardiovascular diseases. Despite many in vivo studies and clinical trials, this issue has not been conclusively resolved. Resveratrol (RES) is one of the most extensively studied dietary polyphenolic antioxidants. Paradoxically, we have previously demonstrated that high RES concentrations exert a pro-oxidant effect eventually elevating ROS levels leading to cell death. Here, we further elucidate the molecular determinants underpinning RES-induced oxidative cell death. Methods: Using human umbilical vein endothelial cells (HUVECs), the effect of increasing concentrations of RES on DNA synthesis and apoptosis was studied. In addition, mRNA and protein levels of cell survival or apoptosis genes, as well as protein kinase C (PKC) activity were determined. Results: While high concentrations of RES reduce PKC activity, inhibit DNA synthesis and induce apoptosis, low RES concentrations elicit an opposite effect. This biphasic concentration-dependent effect (BCDE) of RES on PKC activity is mirrored at the molecular level. Indeed, high RES concentrations upregulate the proapoptotic Bax, while downregulating the antiapoptotic Bcl-2, at both mRNA and protein levels. Similarly, high RES concentrations downregulate the cell cycle progression genes, c-myc, ornithine decarboxylase (ODC) and cyclin D1 protein levels, while low RES concentrations display an increasing trend. The BCDE of RES on PKC activity is abrogated by the ROS scavenger Tempol, indicating that this enzyme acts downstream of the RES-elicited ROS signaling. The RES-induced BCDE on HUVEC cell cycle machinery was also blunted by the flavin inhibitor diphenyleneiodonium (DPI), implicating flavin oxidase-generated ROS as the mechanistic link in the cellular response to different RES concentrations. Finally, PKC inhibition abrogates the BCDE elicited by RES on both cell cycle progression and pro-apoptotic gene expression in HUVECs, mechanistically implicating PKC in the cellular response to different RES concentrations. Conclusions: Our results provide new molecular insight into the impact of RES on endothelial function/dysfunction, further confirming that obtaining an optimal benefit of RES is concentration-dependent. Importantly, the BCDE of RES could explain why other studies failed to establish the cardio-protective effects mediated by natural antioxidants, thus providing a guide for future investigation looking at cardio-protection by natural antioxidants.

scholarly journals Distinct Signaling Pathways Mediate Stimulation of Cell Cycle Progression and Prevention of Apoptotic Cell Death by Estrogen in Rat Pituitary Tumor PR1 Cells

2003 ◽  
Vol 14 (12) ◽  
pp. 5051-5059 ◽  
Author(s):  
Simona Caporali ◽  
Manami Imai ◽  
Lucia Altucci ◽  
Massimo Cancemi ◽  
Silvana Caristi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Death ◽  
Dna Synthesis ◽  
Cell Survival ◽  
Pituitary Tumor ◽  
Cell Cycle Progression ◽  
Cycle Progression ◽  
Rat Pituitary ◽  
Stimulation Of

Estrogens control cell growth and viability in target cells via an interplay of genomic and extragenomic pathways not yet elucidated. Here, we show evidence that cell proliferation and survival are differentially regulated by estrogen in rat pituitary tumor PR1 cells. Pico- to femtomolar concentrations of 17β-estradiol (E2) are sufficient to foster PR1 cell proliferation, whereas nanomolar concentrations of the same are needed to prevent cell death that occurs at a high rate in these cells in the absence of hormone. Activation of endogenous (PRL) or transfected estrogen-responsive genes occurs at the same, higher concentrations of E2 required to promote cell survival, whereas stimulation of cyclin D3 expression and DNA synthesis occur at lower E2 concentrations. Similarly, the pure antiestrogen ICI 182,780 inhibits estrogen response element-dependent trans-activation and cell death more effectively than cyclin-cdk activity, G1-S transition, or DNA synthesis rate. In antiestrogen-treated and/or estrogen-deprived cells, death is due predominantly to apoptosis. Estrogen-induced cell survival, but not E2-dependent cell cycle progression, can be prevented by an inhibitor of c-Src kinase or by blockade of the mitogen-activated protein kinase kinase/extracellular signal-regulated kinase signaling pathway. These data indicate the coexistence of two distinguishable estrogen signaling pathways in PR1 cells, characterized by different functions and sensitivity to hormones and antihormones.

scholarly journals 8Cl-cAMP modifies the balance between PKAR1 and PKAR2 and modulates the cell cycle, growth and apoptosis in human adrenocortical H295R cells

2010 ◽  
Vol 44 (6) ◽  
pp. 331-347 ◽  
Author(s):  
Zhor Bouizar ◽  
Bruno Ragazzon ◽  
Lucie Viou ◽  
Mariuccia Hortane ◽  
Jerôme Bertherat ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Cell Cycle Progression ◽  
Transforming Growth Factor ◽  
Adrenal Adenoma ◽  
Transforming Growth Factor Β ◽  
Nuclear Antigen ◽  
Adrenocortical Cells ◽  
Protein Levels ◽  
The Impact

Various types of protein kinase A (PKA) alterations have been observed in adrenocortical tumours and Carney complex (CNC). PKA is a heterotetramer of two regulatory and two catalytic subunits. The R1A and R2B proteins are the most abundant regulatory subunits in endocrine tissues. A decrease in R2B protein levels has been observed in adrenal adenoma, whereas tumours from patients with CNC display a decrease in R1A protein levels. Dysregulation of the balance between R1A and R2B may thus be involved in adrenal tumourigenesis. We investigated the impact of the differences in the balance of PKA subunits on cell growth using specific cAMP analogues. We assessed the effects of 8-chloroadenosine-cAMP (8Cl-cAMP), a site-selective activator of PKA R2B, in H295R adrenocortical cells. 8Cl-cAMP stimulated PKA activity, decreased R1A levels and increased R2B levels. It had no cytotoxic effects, initially stimulating DNA synthesis and then inducing apoptosis by disrupting G2/M progression. We observed an initial accumulation of cells in the S phase, translocation of cyclin A to the nucleus, CDK2 activation, sustained DNA synthesis and proliferating cell nuclear antigen accumulation. Cell cycle arrest in the G2 phase was parallel with the accumulation of cyclin B and the inactivation of CDC2 kinase. The 8CPT-cAMP, which activates the R2B subunit, had similar effects. R2B silencing reduced the apoptosis induced by tumour necrosis factor α and transforming growth factor β. Thus, R2B is a key regulator of proliferation/differentiation in H295R cell line along with the complex balance between the PKA subunits. Activation of PKA R2B and dysregulation of the R1A/R2B balance regulate cell cycle progression and apoptosis in adrenocortical cells by modulating cyclin production and cyclin-dependent kinase activities.

Control of p21Cip by BRCA1-associated protein is critical for cardiomyocyte cell cycle progression and survival

2019 ◽  
Vol 116 (3) ◽  
pp. 592-604 ◽  
Author(s):  
Cornelia Volland ◽  
Peter Schott ◽  
Michael Didié ◽  
Jörg Männer ◽  
Bernhard Unsöld ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Cell Cycle Regulation ◽  
Cell Cycle Progression ◽  
Kinase Inhibitor ◽  
Ki 67 ◽  
Cycle Progression ◽  
Developmental Arrest ◽  
Cycle Regulation ◽  
The Impact

Abstract Aims Identifying the key components in cardiomyocyte cell cycle regulation is of relevance for the understanding of cardiac development and adaptive and maladaptive processes in the adult myocardium. BRCA1-associated protein (BRAP) has been suggested as a cytoplasmic retention factor for several proteins including Cyclin-dependent-kinase inhibitor p21Cip. We observed profound expressional changes of BRAP in early postnatal myocardium and investigated the impact of BRAP on cardiomyocyte cell cycle regulation. Methods and results General knockout of Brap in mice evoked embryonic lethality associated with reduced myocardial wall thickness and lethal cardiac congestion suggesting a prominent role for BRAP in cardiomyocyte proliferation. αMHC-Cre driven cardiomyocyte-specific knockout of Brap also evoked lethal cardiac failure shortly after birth. Likewise, conditional cardiomyocyte-specific Brap deletion using tamoxifen-induced knockout in adult mice resulted in marked ventricular dilatation and heart failure 3 weeks after induction. Several lines of evidence suggest that Brap deletion evoked marked inhibition of DNA synthesis and cell cycle progression. In cardiomyocytes with proliferative capacity, this causes developmental arrest, whereas in adult hearts loss of BRAP-induced apoptosis. This is explained by altered signalling through p21Cip which we identify as the link between BRAP and cell cycle/apoptosis. BRAP deletion enhanced p21Cip expression, while BRAP overexpression in cardiomyocyte-specific transgenic mice impeded p21Cip expression. That was paralleled by enhanced nuclear Ki-67 expression and DNA synthesis. Conclusion By controlling p21Cip activity BRAP expression controls cell cycle activity and prevents developmental arrest in developing cardiomyocytes and apoptosis in adult cardiomyocytes.

A novel CyclinE/CyclinA-CDK Inhibitor targets p27Kip1 degradation, cell cycle progression and cell survival: Implications in cancer therapy

2013 ◽  
Vol 333 (1) ◽  
pp. 103-112 ◽  
Author(s):  
Lu Dai ◽  
Yuqing Liu ◽  
Junyang Liu ◽  
Xiaoming Wen ◽  
ZhengShuang Xu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cancer Therapy ◽  
Cell Survival ◽  
Cell Cycle Progression ◽  
Cdk Inhibitor ◽  
Cycle Progression

Landomycin a inhibits DNA synthesis and cell cycle progression

1999 ◽  
Vol 9 (12) ◽  
pp. 1663-1666 ◽  
Author(s):  
Robert T Crow ◽  
Betty Rosenbaum ◽  
Roger Smith ◽  
Yu Guo ◽  
Kenneth S Ramos ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Cell Cycle Progression ◽  
Cycle Progression ◽  
Landomycin A

scholarly journals The Activity of Differentiation Factors Induces Apoptosis in Polyomavirus Large T-Expressing Myoblasts

1998 ◽  
Vol 9 (6) ◽  
pp. 1449-1463 ◽  
Author(s):  
Gian Maria Fimia ◽  
Vanesa Gottifredi ◽  
Barbara Bellei ◽  
Maria Rosaria Ricciardi ◽  
Agostino Tafuri ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Death ◽  
Growth Factor ◽  
Cell Cycle Progression ◽  
Transforming Growth Factor ◽  
Myogenic Differentiation ◽  
Transforming Growth Factor Β ◽  
Large Tumor ◽  
Cycle Progression

It is commonly accepted that pathways that regulate proliferation/differentiation processes, if altered in their normal interplay, can lead to the induction of programmed cell death. In a previous work we reported that Polyoma virus Large Tumor antigen (PyLT) interferes with in vitro terminal differentiation of skeletal myoblasts by binding and inactivating the retinoblastoma antioncogene product. This inhibition occurs after the activation of some early steps of the myogenic program. In the present work we report that myoblasts expressing wild-type PyLT, when subjected to differentiation stimuli, undergo cell death and that this cell death can be defined as apoptosis. Apoptosis in PyLT-expressing myoblasts starts after growth factors removal, is promoted by cell confluence, and is temporally correlated with the expression of early markers of myogenic differentiation. The block of the initial events of myogenesis by transforming growth factor β or basic fibroblast growth factor prevents PyLT-induced apoptosis, while the acceleration of this process by the overexpression of the muscle-regulatory factor MyoD further increases cell death in this system. MyoD can induce PyLT-expressing myoblasts to accumulate RB, p21, and muscle- specific genes but is unable to induce G00arrest. Several markers of different phases of the cell cycle, such as cyclin A, cdk-2, and cdc-2, fail to be down-regulated, indicating the occurrence of cell cycle progression. It has been frequently suggested that apoptosis can result from an unbalanced cell cycle progression in the presence of a contrasting signal, such as growth factor deprivation. Our data involve differentiation pathways, as a further contrasting signal, in the generation of this conflict during myoblast cell apoptosis.

The regulation of the DNA damage response at telomeres: focus on kinases

2021 ◽  
Author(s):  
Michela Galli ◽  
Chiara Frigerio ◽  
Maria Pia Longhese ◽  
Michela Clerici
Keyword(s):  
Cell Cycle ◽  
Cellular Response ◽  
Cell Cycle Progression ◽  
Binding Proteins ◽  
Replicative Senescence ◽  
Genome Instability ◽  
Cycle Progression ◽  
Strand Breaks ◽  
Cycle Arrest ◽  
Linear Chromosomes

The natural ends of linear chromosomes resemble those of accidental double-strand breaks (DSBs). DSBs induce a multifaceted cellular response that promotes the repair of lesions and slows down cell cycle progression. This response is not elicited at chromosome ends, which are organized in nucleoprotein structures called telomeres. Besides counteracting DSB response through specialized telomere-binding proteins, telomeres also prevent chromosome shortening. Despite of the different fate of telomeres and DSBs, many proteins involved in the DSB response also localize at telomeres and participate in telomere homeostasis. In particular, the DSB master regulators Tel1/ATM and Mec1/ATR contribute to telomere length maintenance and arrest cell cycle progression when chromosome ends shorten, thus promoting a tumor-suppressive process known as replicative senescence. During senescence, the actions of both these apical kinases and telomere-binding proteins allow checkpoint activation while bulk DNA repair activities at telomeres are still inhibited. Checkpoint-mediated cell cycle arrest also prevents further telomere erosion and deprotection that would favor chromosome rearrangements, which are known to increase cancer-associated genome instability. This review summarizes recent insights into functions and regulation of Tel1/ATM and Mec1/ATR at telomeres both in the presence and in the absence of telomerase, focusing mainly on discoveries in budding yeast.

scholarly journals Cellular Ras and Cyclin D1 Are Required during Different Cell Cycle Periods in Cycling NIH 3T3 Cells

1999 ◽  
Vol 19 (7) ◽  
pp. 4623-4632 ◽  
Author(s):  
Masahiro Hitomi ◽  
Dennis W. Stacey
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Cyclin D1 ◽  
Cell Cycle Progression ◽  
Time Lapse ◽  
S Phase ◽  
3T3 Cells ◽  
Cycle Progression ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

ABSTRACT Novel techniques were used to determine when in the cell cycle of proliferating NIH 3T3 cells cellular Ras and cyclin D1 are required. For comparison, in quiescent cells, all four of the inhibitors of cell cycle progression tested (anti-Ras, anti-cyclin D1, serum removal, and cycloheximide) became ineffective at essentially the same point in G1 phase, approximately 4 h prior to the beginning of DNA synthesis. To extend these studies to cycling cells, a time-lapse approach was used to determine the approximate cell cycle position of individual cells in an asynchronous culture at the time of inhibitor treatment and then to determine the effects of the inhibitor upon recipient cells. With this approach, anti-Ras antibody efficiently inhibited entry into S phase only when introduced into cells prior to the preceding mitosis, several hours before the beginning of S phase. Anti-cyclin D1, on the other hand, was an efficient inhibitor when introduced up until just before the initiation of DNA synthesis. Cycloheximide treatment, like anti-cyclin D1 microinjection, was inhibitory throughout G1 phase (which lasts a total of 4 to 5 h in these cells). Finally, serum removal blocked entry into S phase only during the first hour following mitosis. Kinetic analysis and a novel dual-labeling technique were used to confirm the differences in cell cycle requirements for Ras, cyclin D1, and cycloheximide. These studies demonstrate a fundamental difference in mitogenic signal transduction between quiescent and cycling NIH 3T3 cells and reveal a sequence of signaling events required for cell cycle progression in proliferating NIH 3T3 cells.

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