scholarly journals Differential activation of p44mapk (ERK1) by α-thrombin and thrombin-receptor peptide agonist

1993 ◽  
Vol 289 (1) ◽  
pp. 209-214 ◽  
Author(s):  
V Vouret-Craviari ◽  
E Van Obberghen-Schilling ◽  
J C Scimeca ◽  
E Van Obberghen ◽  
J Pouysségur
Keyword(s):  
Cell Cycle ◽  
Growth Factor ◽  
Late Phase ◽  
Lung Fibroblasts ◽  
Dependent Manner ◽  
Thrombin Cleavage ◽  
Ccl39 Cells ◽  
Peptide Agonist ◽  
G Protein Coupled ◽  
Dose Dependent

alpha-Thrombin (thrombin), a potent mitogen for CCL39 hamster lung fibroblasts, stimulates phosphoinositide-specific phospholipase C (PI-PLC) and inhibits adenylate cyclase via cleavage of a specific G-protein-coupled receptor (TH-R), recently cloned from human and hamster cells. This action can be entirely mimicked by the synthetic peptide SFFLRNP, referred to here as TMP (thrombin-mimicking peptide). TMP corresponds to the first seven amino acids of the new N-terminus generated by thrombin cleavage of the hamster TH-R. Although thrombin and TMP apparently generate identical early transmembrane signals, only thrombin is mitogenic on its own. TMP needs to be associated with fibroblast growth factor (FGF), a tyrosine kinase-activating growth factor, to induce cell-cycle re-entry. Here, we have examined the early and late phase of p44 MAP kinase (p44mapk) activation in G0-arrested CCL39 cells after stimulation by thrombin, TMP, FGF or TMP+FGF. We found that: (i) both thrombin and TMP rapidly activate p44mapk in a dose-dependent manner with maximum activation at around 5 min, (ii) after the initial burst of activation, a second and long-lasting wave of activation is observed in response to thrombin (10-100 nM) but not to TMP (up to 300 microM), (iii) FGF alone (25 ng/ml), like thrombin, rapidly and persistently activates p44mapk (20-fold at 5 min and about 3-fold after 2 h), (iv) TMP added together with FGF strongly potentiates the second and sustained phase of p44mapk activation. From these results we propose that: (1) thrombin-induced mitogenesis is mediated only in part by the TH-R recently cloned and (2) activation of p44mapk, in particular the long-lasting phase that correlates with DNA synthesis, is an obligatory event for cell-cycle re-entry.

Modulation of Pacemaker Activity by Salmon Gonadotropin-Releasing Hormone (sGnRH) in Terminal Nerve (TN)-GnRH Neurons

2000 ◽  
Vol 83 (5) ◽  
pp. 3196-3200 ◽  
Author(s):  
Hideki Abe ◽  
Yoshitaka Oka
Keyword(s):  
Late Phase ◽  
Gonadotropin Releasing Hormone ◽  
Pacemaker Activity ◽  
Dependent Manner ◽  
Releasing Hormone ◽  
Terminal Nerve ◽  
Bath Application ◽  
Gnrh Neurons ◽  
G Protein Coupled ◽  
Dose Dependent

The terminal nerve (TN)-gonadotropin-releasing hormone (GnRH) neurons project widely in the brain instead of the pituitary and show endogenous pacemaker activity that is dependent on the physiological conditions of the animal. We suggest that the TN-GnRH system may act as a putative neuromodulator that is involved in the regulation of many long-lasting changes in the animal's behavior. In the present study, we find that the pacemaker activity of TN-GnRH neurons is modulated by salmon GnRH (sGnRH), which is the same molecular species of GnRH peptide produced by TN-GnRH neurons themselves. Bath application of sGnRH (2–200 nM) transiently decreased (early phase) and then subsequently increased (late phase) the frequency of pacemaker activity of TN-GnRH neurons in a dose-dependent manner. These biphasic changes of pacemaker activities were suppressed by intracellular application of guanosin 5′-0-(2-thiodi-phosphate) (GDP-β-S). The results suggest that G-protein coupled receptors are present on the cell surface and play a triggering role in modulating the frequency of pacemaker activities in TN-GnRH neurons. Because the TN-GnRH neurons make tight cell clusters with no intervening glial cells, it may be further suggested that GnRH released from GnRH neurons regulates the activities of their own (autocrine) and/or neighboring GnRH neurons (paracrine).

scholarly journals Synthesis, cytotoxicity, apoptosis and cell cycle arrest of a ruthenium multi-substituted Keggin-type polyoxotungstate

2021 ◽  
Author(s):  
Shifang Jia ◽  
Yanzhen Wen ◽  
Xiuli Hao ◽  
Yan Zhang
Keyword(s):  
Cell Cycle ◽  
Cell Death ◽  
Cell Cycle Arrest ◽  
Lung Fibroblasts ◽  
Dependent Manner ◽  
Cytotoxic Potential ◽  
Cycle Arrest ◽  
Elemental Analyses ◽  
Keggin Anions ◽  
Dose Dependent

Abstract The ruthenium multi-substituted polyoxotungstate with chemical formulae of K7[SiW9O37Ru4(H2O)3Cl3]·15H2O (S1) was synthesized by a conventional aqueous solution containing the trilacunary Keggin-anions β-Na9HSiW9O34·12H2O(S2) and RuCl3·nH2O(S3). Compound S1 was characterized by elemental analyses, EDS, TG analyses, IR, UV/Vis and XPS. The cytotoxic potential of compound S1 was tested on C33A, DLD-1, HepG-2 cancer cells and human normal embryonic lung fibroblasts cell MRC-5. The viability of the treated cells was evaluated by MTT assay. The mode of cell death was assessed by morphological study of DNA damage and apoptosis assays. Compound S1 induced cell death in a dose-dependent manner, and the mode of cell death was essentially apoptosis though necrosis was also noticed. Cell cycle analysis by flow cytometry indicated that compound S1 caused cell cycle arrest and accumulated cells in S phase.

Synthesis and Biological Evaluation of Novel Heterocyclic Imines Linked Coumarin- Thiazole Hybrids as Anticancer Agents

2019 ◽  
Vol 19 (4) ◽  
pp. 557-566 ◽  
Author(s):  
Nerella S. Goud ◽  
Mahammad S. Ghouse ◽  
Jatoth Vishnu ◽  
Jakkula Pranay ◽  
Ravi Alvala ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Membrane Potential ◽  
Fluorescence Spectroscopy ◽  
Mitochondrial Membrane Potential ◽  
Mitochondrial Membrane ◽  
Annexin V ◽  
Biological Evaluation ◽  
Dependent Manner ◽  
Dapi Staining ◽  
Dose Dependent

Background: Human Galectin-1, a protein of lectin family showing affinity towards β-galactosides has emerged as a critical regulator of tumor progression and metastasis, by modulating diverse biological events including homotypic cell aggregation, migration, apoptosis, angiogenesis and immune escape. Therefore, galectin-1 inhibitors might represent novel therapeutic agents for cancer. Methods: A new series of heterocyclic imines linked coumarin-thiazole hybrids (6a-6r) was synthesized and evaluated for its cytotoxic potential against a panel of six human cancer cell lines namely, lung (A549), prostate (DU-145), breast (MCF-7 & MDA-MB-231), colon (HCT-15 & HT-29) using MTT assay. Characteristic apoptotic assays like DAPI staining, cell cycle, annexin V and Mitochondrial membrane potential studies were performed for the most active compound. Furthermore, Gal-1 inhibition was confirmed by ELISA and fluorescence spectroscopy. Results: Among all, compound 6g 3-(2-(2-(pyridin-2-ylmethylene) hydrazineyl) thiazol-4-yl)-2H-chromen-2- one exhibited promising growth inhibition against HCT-15 colorectal cancer cells with an IC50 value of 1.28 ± 0.14 µM. The characteristic apoptotic morphological features like chromatin condensation, membrane blebbing and apoptotic body formation were clearly observed with compound 6g on HCT-15 cells using DAPI staining studies. Further, annexin V-FITC/PI assay confirmed effective early apoptosis induction by treatment with compound 6g. Loss of mitochondrial membrane potential and enhanced ROS generation were confirmed with JC-1 and DCFDA staining method, respectively by treatment with compound 6g, suggesting a possible mechanism for inducing apoptosis. Moreover, flow cytometric analysis revealed that compound 6g blocked G0/G1 phase of the cell cycle in a dose-dependent manner. Compound 6g effectively reduced the levels of Gal-1 protein in a dose-dependent manner. The binding constant (Ka) of 6g with Gal-1 was calculated from the intercept value which was observed as 1.9 x 107 M-1 by Fluorescence spectroscopy. Molecular docking studies showed strong interactions of compound 6g with Gal-1 protein. Conclusion: Our studies demonstrate the anticancer potential and Gal-1 inhibition of heterocyclic imines linked coumarin-thiazole hybrids.

scholarly journals The Olive Leaves Extract Has Anti-Tumor Effects against Neuroblastoma through Inhibition of Cell Proliferation and Induction of Apoptosis

Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2178
Author(s):  
Fabio Morandi ◽  
Veronica Bensa ◽  
Enzo Calarco ◽  
Fabio Pastorino ◽  
Patrizia Perri ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Viability ◽  
Cell Cycle Progression ◽  
Treatment Strategies ◽  
Annexin V ◽  
Dependent Manner ◽  
Induction Of Apoptosis ◽  
Dose Dependent

Neuroblastoma (NB) is the most common extra-cranial solid tumor of pediatric age. The prognosis for high-risk NB patients remains poor, and new treatment strategies are desirable. The olive leaf extract (OLE) is constituted by phenolic compounds, whose health beneficial effects were reported. Here, the anti-tumor effects of OLE were investigated in vitro on a panel of NB cell lines in terms of (i) reduction of cell viability; (ii) inhibition of cell proliferation through cell cycle arrest; (iii) induction of apoptosis; and (iv) inhibition of cell migration. Furthermore, cytotoxicity experiments, by combining OLE with the chemotherapeutic topotecan, were also performed. OLE reduced the cell viability of NB cells in a time- and dose-dependent manner in 2D and 3D models. NB cells exposed to OLE underwent inhibition of cell proliferation, which was characterized by an arrest of the cell cycle progression in G0/G1 phase and by the accumulation of cells in the sub-G0 phase, which is peculiar of apoptotic death. This was confirmed by a dose-dependent increase of Annexin V+ cells (peculiar of apoptosis) and upregulation of caspases 3 and 7 protein levels. Moreover, OLE inhibited the migration of NB cells. Finally, the anti-tumor efficacy of the chemotherapeutic topotecan, in terms of cell viability reduction, was greatly enhanced by its combination with OLE. In conclusion, OLE has anti-tumor activity against NB by inhibiting cell proliferation and migration and by inducing apoptosis.

Safflower injection inhibits pulmonary arterial remodeling in a monocrotaline-induced pulmonary arterial hypertension rat model

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Aifeng Chen ◽  
Shibiao Ding ◽  
Liangliang Kong ◽  
Jianpu Xu ◽  
Fei He ◽  
...  
Keyword(s):  
Growth Factor ◽  
Pulmonary Arterial Hypertension ◽  
Pulmonary Artery ◽  
Arterial Hypertension ◽  
Cardiac Muscle ◽  
Rat Model ◽  
Dependent Manner ◽  
Arterial Remodeling ◽  
Pulmonary Arterial ◽  
Dose Dependent

AbstractPulmonary arterial hypertension (PAH) is a group of diseases with an increase of pulmonary artery pressure (PAP) and pulmonary vascular resistance. Here, the effects of safflower injection, a preparation of Chinese herbs, was investigated in a monocrotaline (MCT)-induced PAH rat model. PAP, carotid artery pressure (CAP), and the right ventricular hypertrophy index (RVHI) increased in the PAH group, while safflower injection was able to inhibit this increase to similar levels as observed in the normal group. The arteriole wall of the lungs and cardiac muscle were thickened and edema was observed in the PAH group, while these pathologies were improved in the herb-treated group in a dose-dependent manner. MCT treatment induced proliferation of pulmonary artery smooth muscle cells (PASMCs), which was inhibited by safflower injection in a dose-dependent manner. Our experimental results demonstrated that safflower injection can regulate pulmonary arterial remodeling through affecting the expression of connective tissue growth factor, transforming growth factor-β, integrin, collagen or fibronectin, which subsequently affected the thicknesses of the arteriole walls of the lungs and cardiac muscle, and thereby benefits the control of PAH. This means safflower injection improved the abnormalities in PAP, CAP and RVHI, and pulmonary arterial remodeling through regulation of remodeling factors.

scholarly journals Growth-factor-dependent phosphorylation of Bim in mitosis

2005 ◽  
Vol 388 (1) ◽  
pp. 185-194 ◽  
Author(s):  
Mário GRÃOS ◽  
Alexandra D. ALMEIDA ◽  
Sukalyan CHATTERJEE
Keyword(s):  
Cell Cycle ◽  
Cell Death ◽  
Growth Factor ◽  
Cell Fate ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Post Translational Modification ◽  
Proliferating Cells ◽  
Growth Factor Signalling ◽  
Induced Apoptosis

The regulation of survival and cell death is a key determinant of cell fate. Recent evidence shows that survival and death machineries are regulated along the cell cycle. In the present paper, we show that BimEL [a BH3 (Bcl-2 homology 3)-only member of the Bcl-2 family of proteins; Bim is Bcl-2-interacting mediator of cell death; EL is the extra-long form] is phosphorylated in mitosis. This post-translational modification is dependent on MEK (mitogen-activated protein kinase/extracellular-signal-regulated kinase kinase) and growth factor signalling. Interestingly, FGF (fibroblast growth factor) signalling seems to play an essential role in this process, since, in the presence of serum, inhibition of FGF receptors abrogated phosphorylation of Bim in mitosis. Moreover, we have shown bFGF (basic FGF) to be sufficient to induce phosphorylation of Bim in serum-free conditions in any phase of the cell cycle, and also to significantly rescue cells from serum-deprivation-induced apoptosis. Our results show that, in mitosis, Bim is phosphorylated downstream of growth factor signalling in a MEK-dependent manner, with FGF signalling playing an important role. We suggest that phosphorylation of Bim is a decisive step for the survival of proliferating cells.

scholarly journals Regulation of fibroblast procollagen production. Transforming growth factor-β1 induces prostaglandin E2 but not procollagen synthesis via a pertussis toxin-sensitive G-protein

1995 ◽  
Vol 307 (1) ◽  
pp. 63-68 ◽  
Author(s):  
R J McAnulty ◽  
R C Chambers ◽  
G J Laurent
Keyword(s):  
Growth Factor ◽  
Prostaglandin E2 ◽  
G Protein ◽  
Pertussis Toxin ◽  
Transforming Growth Factor ◽  
Pge2 Production ◽  
Lung Fibroblasts ◽  
Extracellular Matrix Protein ◽  
Dependent Manner ◽  
Tgf Beta

Transforming growth factor-beta 1 (TGF beta 1) initiates a series of signalling events resulting in diverse cellular responses including stimulation of extracellular matrix protein production. In this study we have investigated the role of pertussis toxin-sensitive G-proteins in mediating the effects of TGF beta 1 on fibroblast procollagen metabolism. TGF beta 1 stimulated human fetal lung fibroblast procollagen synthesis and production in a dose-dependent manner which was maximal at 0.5 ng/ml. TGF beta 1 also decreased the proportion of newly synthesized procollagen degraded intracellularly. Pertussis toxin, a G-protein inhibitor, further stimulated TGF beta 1-induced procollagen synthesis and production, but alone it had no effect on fibroblast procollagen metabolism. Addition of indomethacin also potentiated the TGF beta 1-induced increase in procollagen synthesis and production. The effects of pertussis toxin and indomethacin were not additive. Pertussis toxin and indomethacin did not affect the proportion of newly synthesized procollagen degraded intracellularly, either alone or in combination, by control cells. The TGF beta 1-induced decrease in intracellular procollagen degradation was maintained but not further affected by pertussis toxin or indomethacin. TGF beta 1 increased prostaglandin E2 (PGE2) compared with PGE2 production by control cells. Addition of pertussis toxin or indomethacin blocked the TGF beta 1-induced increase in PGE2 production. The TGF beta 1-induced increase in PGE2 preceded the increase in procollagen production. These results demonstrate that TGF beta 1-induced procollagen synthesis by lung fibroblasts is modulated by production of PGE2. Pertussis toxin and indomethacin block the production of PGE2 and enhance the effect of TGF beta 1 on procollagen synthesis. From these data we conclude that the effects of TGF beta 1 on PGE2 production but not procollagen synthesis are mediated via a receptor linked to a pertussis toxin-sensitive G-protein.

scholarly journals Baicalein Inhibits the Proliferation of Cervical Cancer Cells Through the GSK3β-Dependent Pathway

2018 ◽  
Vol 26 (4) ◽  
pp. 645-653 ◽  
Author(s):  
Xiaoling Wu ◽  
Zhiqin Yang ◽  
Huimin Dang ◽  
Huixia Peng ◽  
Zhijun Dai
Keyword(s):  
Cell Cycle ◽  
Cervical Cancer ◽  
Cyclin D1 ◽  
Cancer Cells ◽  
Hela Cells ◽  
Glycogen Synthase ◽  
Dependent Manner ◽  
Cervical Cancer Cells ◽  
Dose Dependent ◽  
Dependent Pathway

Baicalein, a flavonoid derived from the root of Scutellaria baicalensis, has been reported to possess multiple pharmacological activities, such as anticancer and anti-inflammatory properties. This study investigated the effect of baicalein in cervical cancer cells. Cell growth curve and MTT assay were performed and revealed that baicalein inhibited the proliferation of SiHa and HeLa cells in a dose-dependent manner. We further found that baicalein arrested the cell cycle of SiHa and HeLa cells at the G0/G1 phase by suppressing the expression of cyclin D1 through the downregulation of phosphorylated protein kinase B (p-AKT) and phosphorylated glycogen synthase kinase 3β (p-GSK3β) according to FACS assays and Western blotting. Moreover, when CHIR-99021, a GSK3β inhibitor, was added to baicalein-treated SiHa cells, the expression of cyclin D1 was recovered, and cell proliferation was promoted. In conclusion, these data indicated that baicalein suspended the cell cycle at the G0/G1 phase via the downregulation of cyclin D1 through the AKT‐GSK3β signaling pathway and further inhibited the proliferation of SiHa and HeLa cervical cancer cells.

scholarly journals Epidermal growth factor and Ras regulate gene expression in GH4 pituitary cells by separate, antagonistic signal transduction pathways.

1995 ◽  
Vol 15 (12) ◽  
pp. 6777-6784 ◽  
Author(s):  
C A Pickett ◽  
A Gutierrez-Hartmann
Keyword(s):  
Signal Transduction ◽  
Transcription Factors ◽  
Growth Factor ◽  
Map Kinase ◽  
Dominant Negative ◽  
Neuroendocrine Cells ◽  
Dependent Manner ◽  
Epidermal Growth ◽  
Dose Dependent

We have previously demonstrated that epidermal growth factor (EGF) produces activation of the rat prolactin (rPRL) promoter in GH4 neuroendocrine cells via a Ras-independent mechanism. This Ras independence of the EGF response appears to be cell rather than promoter specific. Oncogenic Ras also produces activation of the rPRL promoter when transfected into GH4 cells and requires the sequential activation of Raf kinase, mitogen-activated protein (MAP) kinase, and c-Ets-1/GHF-1 to mediate this response. In these studies, we have investigated the interaction between EGF and Ras in stimulating rPRL promoter activity and the role of Raf and MAP kinases in mediating the EGF response. We have also examined the role of several transcription factors and used various promoter mutants of the rPRL gene in order to better define the trans- and cis-acting components of the EGF response. EGF treatment of GH4 cells inhibits activation of the rPRL promoter produced by transfection of V12Ras from 24- to 4-fold in an EGF dose-dependent manner. This antagonistic effect of EGF and Ras is mutual in that transfection of V12Ras also blocks EGF-induced activation of the rPRL promoter in a Ras dose-dependent manner, from 5.5- to 1.6-fold. Transfection of a plasmid encoding the dominant-negative Raf C4 blocks Ras-induced activation by 66% but fails to inhibit EGF-mediated activation of the rPRL promoter. Similarly, transfection of a construct encoding an inhibitory form of MAP kinase decreases the Ras response by 50% but does not inhibit the EGF response. Previous studies have demonstrated that c-Ets-1 is necessary and that GHF-1 acts synergistically with c-Ets-1 in the Ras response of the rPRL promoter. In contrast, overexpression of neither c-Ets-1 nor GHF-1 enhanced EGF-mediated activation of the rPRL promoter, and dominant-negative forms of these transcription factors failed to inhibit the EGF response. Using 5' deletion and site-specific mutations, we have mapped the EGF response to two regions on the proximal rPRL promoter. One region maps between -255 and -212, near the Ras response element, and a second maps between -125 and -54. The latter region appears to involve footprint 2, a previously identified repressor site on the rPRL promoter. Neither footprint 1 nor 3, known GHF-1 binding sites, appears to be crucial to RGF-mediated rPRL promoter activation. The results of these studies indicate that in GH4 neuroendocrine cells, rPRL gene regulation by EGF is mediated by a signal transduction pathway that is separate and antagonistic to the Ras pathway. Hence, the functional role of the Ras/Raf/MAP kinase pathway in mediating transcriptional responses to EGF and other receptor tyrosine kinase may differ in highly specialized cell types.

Sign in / Sign up

Export Citation Format

Share Document