scholarly journals The Milk Thistle (Silybum marianum) Compound Silibinin Inhibits Cardiomyogenesis of Embryonic Stem Cells by Interfering with Angiotensin II Signaling

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Enas Hussein Ali ◽  
Fatemeh Sharifpanah ◽  
Amer Taha ◽  
Suk Ying Tsang ◽  
Maria Wartenberg ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Es Cells ◽  
Embryonic Stem ◽  
Embryoid Bodies ◽  
Mitogen Activated Protein Kinase ◽  
Milk Thistle ◽  
Ang Ii ◽  
Silybum Marianum ◽  
Angiotensin Ii Signaling ◽  
Mitogen Activated Protein

The milk thistle (Silybum marianum (L.) Gaertn.) compound silibinin may be an inhibitor of the angiotensin II type 1 (AT1) receptor which is expressed in differentiating embryonic stem (ES) cells and is involved in the regulation of cardiomyogenesis. In the present study, it was demonstrated that silibinin treatment decreased the number of spontaneously contracting cardiac foci and cardiac cell areas differentiated from ES cells as well as contraction frequency and frequency of calcium (Ca2+) spiking. In contrast, angiotensin II (Ang II) treatment stimulated cardiomyogenesis as well as contraction and Ca2+ spiking frequency, which were abolished in the presence of silibinin. Intracellular Ca2+ transients elicited by Ang II in rat smooth muscle cells were not impaired upon silibinin treatment, excluding the possibility that the compound acted on the AT1 receptor. Ang II treatment activated extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun NH2-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK) pathways in embryoid bodies which were abolished upon silibinin pretreatment. In summary, our data suggest that silibinin inhibits cardiomyogenesis of ES cells by interfering with Ang II signaling downstream of the AT1 receptor.

Angiotensin II regulates phosphorylation of translation elongation factor-2 in cardiac myocytes

2001 ◽  
Vol 281 (1) ◽  
pp. H161-H167 ◽  
Author(s):  
Allen D. Everett ◽  
Tamara D. Stoops ◽  
Angus C. Nairn ◽  
David Brautigan
Keyword(s):  
Protein Synthesis ◽  
Angiotensin Ii ◽  
Cardiac Myocytes ◽  
Elongation Factor ◽  
Protein Translation ◽  
Mitogen Activated Protein Kinase ◽  
Ang Ii ◽  
Elongation Factor 2 ◽  
Mitogen Activated Protein ◽  
20 Nm

Increased protein synthesis is the cardinal feature of cardiac hypertrophy. We have studied angiotensin II (ANG II)-dependent regulation of eukaryotic elongation factor-2 (eEF-2), an essential component of protein translation required for polypeptide elongation, in rat neonatal cardiac myocytes. eEF2 is fully active in its dephosphorylated state and is inhibited following phosphorylation by eEF2 kinase. ANG II treatment (10−10–10−7 M) for 30 min produced an AT1 receptor-specific and concentration- and time-dependent reduction in the phosphorylation of eEF-2. Protein phosphatase 2A (PP2A) inhibitors okadaic acid and fostriecin, but not the PP2B inhibitor FK506, attenuated ANG II-dependent dephosphorylation of eEF-2. ANG II activated mitogen-activated protein kinase, (MAPK) within 10 min of treatment, and blockade of MAPK activation with PD-98059 (1–20 nM) inhibited eEF-2 dephosphorylation. The effect of ANG II on eEF-2 dephosphorylation was also blocked by LY-29004 (1–20 nM), suggesting a role for phosphoinositide 3-kinase, but the mammalian target rapamycin inhibitor rapamycin (10–100 nM) had no effect. Together these results suggest that the ANG II-dependent increase in protein synthesis includes activation of eEF-2 via dephosphorylation by PP2A by a process that involves both PI3K and MAPK.

scholarly journals Angiotensin II Activates Mitogen-Activated Protein Kinase Via Protein Kinase C and Ras/Raf-1 Kinase in Bovine Adrenal Glomerulosa Cells

Endocrinology ◽  
1998 ◽  
Vol 139 (4) ◽  
pp. 1801-1809 ◽  
Author(s):  
Ying Tian ◽  
Roger D. Smith ◽  
Tamas Balla ◽  
Kevin J. Catt
Keyword(s):  
Protein Kinase C ◽  
Angiotensin Ii ◽  
Protein Kinase ◽  
Time Course ◽  
Mitogen Activated Protein Kinase ◽  
Ang Ii ◽  
Mapk Activation ◽  
Kinase C ◽  
Mitogen Activated Protein ◽  
Glomerulosa Cells

Abstract Angiotensin II (Ang II) stimulates growth and mitogenesis in bovine adrenal glomerulosa cells, but little is known about the signaling pathways that mediate these responses. An analysis of the growth-promoting pathways in cultured bovine adrenal glomerulosa cells revealed that Ang II, acting via the AT1 receptor, caused rapid but transient activation of mitogen-activated protein kinase (MAPK), with an ED50 of 10–50 pm. Although neither Ca2+ influx nor Ca2+ release from intracellular stores was sufficient to activate MAPK, Ca2+ appeared to play a permissive role in this response. A major component of Ang II-induced MAPK activation was insensitive to pertussis toxin (PTX), although a minor PTX-sensitive component could not be excluded. Ang II also induced the rapid activation of ras and raf-1 kinase with time-courses that correlated with that of MAPK. Activation of protein kinase C (PKC) by phorbol 12-myristate 13-acetate was sufficient to activate both MAPK and raf-1 kinase. However, whereas PKC depletion had no effect on Ang II-induced raf-1 kinase activation, it attenuated Ang II-induced MAPK activation. Ang II also stimulated a mobility shift of raf-1, reflecting hyperphosphorylation of the kinase. However, unlike its activation, raf-1 hyperphosphorylation was dependent on PKC and its time-course correlated not with activation, but rather with deactivation of the kinase. Taken together, these findings indicate that Ang II stimulates multiple pathways to MAPK activation via PKC and ras/raf-1 kinase in bovine adrenal glomerulosa cells.

Cell context–specific effects of the BCR-ABL oncogene monitored in hematopoietic progenitors

Blood ◽  
2003 ◽  
Vol 101 (10) ◽  
pp. 4088-4097 ◽  
Author(s):  
Stephane Wong ◽  
Jami McLaughlin ◽  
Donghui Cheng ◽  
Owen N. Witte
Keyword(s):  
Cell Death ◽  
Programmed Cell Death ◽  
Mapk Pathway ◽  
Es Cells ◽  
Embryonic Stem ◽  
Mitogen Activated Protein Kinase ◽  
Hematopoietic Progenitors ◽  
Mitogen Activated Protein ◽  
Context Specific

AbstractAcute BCR-ABL expression during in vitro hematopoietic development of embryonic stem (ES) cells causes expansion of multipotent and myeloid progenitors with a concomitant reduction in differentiation toward erythroblasts. Progenitor cell expansion is due to a rapid, cell autonomous, suppression of programmed cell death with an increase in expression of the antiapoptotic molecule BCL-XL. Other antiapoptotic effectors, including AKT, STAT5, and BCL-2 are not up-regulated by BCR-ABL in this system. In addition, the proapoptotic p38 mitogen–activated protein kinase (MAPK) pathway is suppressed by BCR-ABL expression in ES-derived hematopoietic progenitors. Inhibition of p38 MAPK by the small molecule inhibitor SB203580 expanded ES-derived hematopoietic progenitors by an antiapoptotic mechanism and is sufficient to expand ES-derived hematopoietic progenitors to levels approaching 80% of that seen following BCR-ABL expression. In the cellular context of ES-derived hematopoietic progenitors, BCR-ABL expression expands cells by suppressing programmed cell death with a set of antiapoptotic pathways distinct from those previously reported in continuous cell line studies.

Silibinin from Silybum marianum Stimulates Embryonic Stem Cell Vascular Differentiation via the STAT3/PI3-K/AKT Axis and Nitric Oxide

Planta Medica ◽  
2018 ◽  
Vol 84 (11) ◽  
pp. 768-778 ◽  
Author(s):  
Enas Ali ◽  
Fatemeh Sharifpanah ◽  
Maria Wartenberg ◽  
Heinrich Sauer
Keyword(s):  
Nitric Oxide ◽  
Stem Cell ◽  
Protein Expression ◽  
Es Cells ◽  
Embryonic Stem ◽  
Embryoid Bodies ◽  
Vascular Endothelial ◽  
Silybum Marianum ◽  
Branching Points ◽  
Vascular Branching

AbstractSilibinin, the bioactive compound of milk thistle (Silybum marianum), exerts tissue protective and regenerative effects that may include stem cell differentiation toward vascular cells. The purpose of the present study was to investigate whether silibinin stimulates blood vessel formation from mouse embryonic stem (ES) cells and to unravel the underlying signaling cascade. Vascular branching points were assessed by confocal laser scanning microscopy and computer-assisted image analysis of CD31-positive cell structures. Protein expression of vascular markers and activation of protein kinases were determined by western blot. Nitric oxide (NO) generation was investigated by use of the fluorescent dye 4-amino-5-methylamino-2′,7′-difluorofluorescein diacetate. Silibinin dose-dependently increased CD31-positive vascular branching points in embryoid bodies cultivated from ES cells. This was paralleled by increase of protein expression levels for the endothelial-specific markers vascular endothelial cadherin (VE-cadherin), vascular endothelial growth factor receptor 2, and hypoxia-inducible factor-1α. Moreover, silibinin increased activation of endothelial nitric oxide synthase (eNOS), which boosted generation of NO in embryoid bodies and enhanced phosphorylation of signal transducer and activator of transcription 3 (STAT3) as well as phosphoinositide 3-kinase (PI3-K) and AKT. Vasculogenesis, VE-cadherin expression, STAT3 and AKT phosphorylation, NO generation, and eNOS phosphorylation were inhibited by the small molecule STAT3 inhibitor Stattic, AKT inhibitor VIII, the PI3-K inhibitor LY294002, or the NOS inhibitor Nω-Nitro-L-arginine methyl ester hydrochloride. In conclusion, our findings indicate that silibinin induces vasculogenesis of ES cells via activation of STAT3, PI3-K, and AKT, which regulate NO generation by eNOS.

scholarly journals NAMPT/SIRT1 Attenuate Ang II-Induced Vascular Remodeling and Vulnerability to Hypertension by Inhibiting the ROS/MAPK Pathway

2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Lei Zhou ◽  
Sheng Zhang ◽  
Enkhbat Bolor-Erdene ◽  
Lingwei Wang ◽  
Ding Tian ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Vascular Remodeling ◽  
Mapk Pathway ◽  
Sirtuin 1 ◽  
Mitogen Activated Protein Kinase ◽  
Ang Ii ◽  
Nicotinamide Phosphoribosyltransferase ◽  
Aortic Endothelial Cells ◽  
Mitogen Activated Protein

Hypertension is characterized by endothelial dysfunction, vascular remodeling, and rearrangement of the extracellular matrix. Besides, the pathogenesis of hypertension is closely related to excess generation of reactive oxygen species (ROS). Nicotinamide phosphoribosyltransferase (NAMPT) is a rate-limiting enzyme in nicotinamide adenine dinucleotide (NAD) biosynthesis that influences the activity of NAD-dependent enzymes, such as sirtuins, which possess NAD-dependent protein deacetylase activity and cleave NAD during the deacetylation cycle. Recently, NAMPT has been shown to play a crucial role in various diseases associated with oxidative stress. However, the function and regulation of NAMPT in hypertension have not been extensively explored. In the present study, we identified NAMPT as a crucial regulator of hypertension, because NAMPT expression was significantly downregulated in both patients with hypertension and experimental animals. NAMPT knockout (NAMPT+/-) mice exhibited a significantly higher blood pressure and ROS levels after stimulation with angiotensin II (Ang II) than wild-type mice, and the administration of recombinant human NAMPT (rhNAMPT) reversed this effect. In vivo, overexpression of NAMPT protected against angiotensin II- (Ang II-) induced hypertension by inhibiting ROS production via sirtuin 1 in mouse aortic endothelial cells (MAECs) and mouse aortic vascular smooth muscle cells (MOVAs). In turn, NAMPT alleviated the ROS-induced mitogen-activated protein kinase (MAPK) pathway. In conclusion, NAMPT might be a novel biomarker and a therapeutic target in hypertension.

scholarly journals I-κB Kinase-ε Deficiency Attenuates the Development of Angiotensin II-Induced Myocardial Hypertrophy in Mice

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yide Cao ◽  
Liangpeng Li ◽  
Yafeng Liu ◽  
Ganyi Chen ◽  
Zhonghao Tao ◽  
...  
Keyword(s):  
Heart Failure ◽  
Angiotensin Ii ◽  
Myocardial Hypertrophy ◽  
Peptide Hormone ◽  
Mitogen Activated Protein Kinase ◽  
Mouse Heart ◽  
Ang Ii ◽  
Extracellular Signal ◽  
Mitogen Activated Protein

I-κB kinase-ε (IKKε) is a member of the IKK complex and a proinflammatory regulator that is active in many diseases. Angiotensin II (Ang II) is a vasoconstricting peptide hormone, and Ang II-induced myocardial hypertrophy is a common cardiovascular disease that can result in heart failure. In this study, we sought to determine the role of IKKε in the development of Ang II-induced myocardial hypertrophy in mice. Wild-type (WT) and IKKε-knockout (IKKε-KO) mice were generated and infused with saline or Ang II for 8 weeks. We found that WT mouse hearts have increased IKKε expression after 8 weeks of Ang II infusion. Our results further indicated that IKKε-KO mice have attenuated myocardial hypertrophy and alleviated heart failure compared with WT mice. Additionally, Ang II-induced expression of proinflammatory and collagen factors was much lower in the IKKε-KO mice than in the WT mice. Apoptosis and pyroptosis were also ameliorated in IKKε-KO mice. Mechanistically, IKKε bound to extracellular signal-regulated kinase (ERK) and the mitogen-activated protein kinase p38, resulting in MAPK/ERK kinase (MEK) phosphorylation, and IKKε deficiency inhibited the phosphorylation of MEK-ERK1/2 and p38 in mouse heart tissues after 8 weeks of Ang II infusion. The findings of our study reveal that IKKε plays an important role in the development of Ang II-induced myocardial hypertrophy and may represent a potential therapeutic target for the management of myocardial hypertrophy.

Requirement for mitogen-activated protein kinase activation in the response of embryonic stem cell–derived hematopoietic cells to thrombopoietin in vitro

Blood ◽  
2002 ◽  
Vol 99 (4) ◽  
pp. 1174-1182 ◽  
Author(s):  
Marie-Dominique Filippi ◽  
Françoise Porteu ◽  
Françoise Le Pesteur ◽  
Valérie Schiavon ◽  
Gaël A. Millot ◽  
...  
Keyword(s):  
Growth Factors ◽  
Protein Kinase ◽  
Mapk Pathway ◽  
Es Cells ◽  
Embryonic Stem ◽  
Mitogen Activated Protein Kinase ◽  
Mapk Activation ◽  
Terminal Domain ◽  
Mitogen Activated Protein

Enforced expression of c-mpl in embryonic stem (ES) cells inactivated for this gene results in protein expression in all the ES cell progeny, producing cells that do not belong to the megakaryocytic lineage and are responsive to PEG-rhuMGDF, a truncated form of human thrombopoietin (TPO) conjugated to polyethylene glycol. These include a primitive cell called BL-CFC, thought to represent the equivalent of the hemangioblast, and all myeloid progenitor cells. In this model, PEG-rhuMGDF was able to potentiate the stimulating effects of other growth factors, including vascular endothelial growth factor, on BL-CFC and a combination of cytokines on the growth of granulocyte macrophage–colony-forming units. The importance of the C-terminal domain of Mpl and of mitogen-activated protein kinase (MAPK) activation in TPO-dependent megakaryocytic differentiation has been well studied in vitro. Here, the role of this domain and the involvement of MAPK in upstream and nonmegakaryocytic cells are examined by using 2 truncated mutants of Mpl (Δ34, deletion of residues 71 to 121 in the C-terminal domain; and Δ3, deletion of residues 71-94) and specific inhibitors of the MAPK pathway. The 2 deleted regions support different functions, mediated by different signals. Residues 71 to 121 were required for PEG-rhuMGDF–dependent growth of BL-CFC, for megakaryocytic and other myeloid progenitors, and for megakaryocyte polyploidization. These responses were mediated by the ERK1–ERK2 MAPK pathway. In contrast, the only function of the sequence comprising residues 71 to 94 was to mediate the synergistic effects of PEG-rhuMGDF with other hematopoietic growth factors. This function is not mediated by MAPK activation.

The ground state of pluripotency

2010 ◽  
Vol 38 (4) ◽  
pp. 1027-1032 ◽  
Author(s):  
Jason Wray ◽  
Tuzer Kalkan ◽  
Austin G. Smith
Keyword(s):  
Ground State ◽  
Cell Biology ◽  
Kinase Inhibitors ◽  
Glycogen Synthase ◽  
Es Cells ◽  
Embryonic Stem ◽  
Mitogen Activated Protein Kinase ◽  
Mammalian Development ◽  
Mitogen Activated Protein ◽  
The Stability

Pluripotency is defined as the capacity of individual cells to initiate all lineages of the mature organism in response to signals from the embryo or cell culture environment. A pluripotent cell has no predetermined programme; it is a blank slate. This is the foundation of mammalian development and of ES (embryonic stem) cell biology. What are the design principles of this naïve cell state? How is pluripotency acquired and maintained? Suppressing activation of ERKs (extracellular-signal-regulated kinases) is critical to establishing and sustaining ES cells. Inhibition of GSK3 (glycogen synthase kinase 3) reinforces this effect. We review the effect of selective kinase inhibitors on pluripotent cells and consider how these effects are mediated. We propose that ES cells represent a ground state, meaning a basal proliferative state that is free of epigenetic restriction and has minimal requirements for extrinsic stimuli. The stability of this state is reflected in the homogeneity of ES cell populations cultured in the presence of small-molecule inhibitors of MEK (mitogen-activated protein kinase/ERK kinase) and GSK3.

scholarly journals Angiotensin II regulation of neuromodulation: downstream signaling mechanism from activation of mitogen-activated protein kinase.

1996 ◽  
Vol 135 (6) ◽  
pp. 1609-1617 ◽  
Author(s):  
D Lu ◽  
H Yang ◽  
M K Raizada
Keyword(s):  
Angiotensin Ii ◽  
Map Kinase ◽  
Signaling Pathway ◽  
Mitogen Activated Protein Kinase ◽  
Receptor Subtype ◽  
Ang Ii ◽  
Signaling Mechanism ◽  
Downstream Signaling ◽  
Neuronal Soma ◽  
Mitogen Activated Protein

Angiotensin II (Ang II) stimulates expression of tyrosine hydroxylase and norepinephrine transporter genes in brain neurons; however, the signal-transduction mechanism is not clearly defined. This study was conducted to determine the involvement of the mitogen-activated protein (MAP) kinase signaling pathway in Ang II stimulation of these genes. MAP kinase was localized in the perinuclear region of the neuronal soma. Ang II caused activation of MAP kinase and its subsequent translocation from the cytoplasmic to nuclear compartment, both effects being mediated by AT1 receptor subtype. Ang II also stimulated SRE- and AP1-binding activities and fos gene expression and its translocation in a MAP kinase-dependent process. These observations are the first demonstration of a downstream signaling pathway involving MAP kinase in Ang II-mediated neuromodulation in noradrenergic neurons.

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