Warfarin-exposed zebrafish embryos resembles human warfarin embryopathy in a dose and developmental-time dependent manner – From molecular mechanisms to environmental concerns

2019 ◽  
Vol 181 ◽  
pp. 559-571 ◽  
Author(s):  
Luis Granadeiro ◽  
Ron P. Dirks ◽  
Juan B. Ortiz-Delgado ◽  
Paulo J. Gavaia ◽  
Carmen Sarasquete ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Developmental Time ◽  
Time Dependent ◽  
Environmental Concerns ◽  
Zebrafish Embryos ◽  
Dependent Manner ◽  
Warfarin Embryopathy

scholarly journals The multi-site docking protein Grb2-associated binder 1 (Gab1) enhances interleukin-6-induced MAPK-pathway activation in an SHP2-, Grb2-, and time-dependent manner

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Hannes Bongartz ◽  
Karen Gille ◽  
Wiebke Hessenkemper ◽  
Katharina Mandel ◽  
Marc Lewitzky ◽  
...  
Keyword(s):  
Interleukin 6 ◽  
Molecular Mechanisms ◽  
Mapk Pathway ◽  
Sh2 Domain ◽  
Time Dependent ◽  
Signalling Pathways ◽  
Dependent Manner ◽  
Mapk Activation ◽  
Pathway Activation ◽  
Mapk Signalling

Abstract Background Cytokine-dependent activation of signalling pathways is tightly orchestrated. The spatiotemporal activation of signalling pathways dictates the specific physiological responses to cytokines. Dysregulated signalling accounts for neoplastic, developmental, and inflammatory diseases. Grb2-associated binder (Gab) family proteins are multi-site docking proteins, which expand cytokine-induced signal transduction in a spatial- and time-dependent manner by coordinating the recruitment of proteins involved in mitogen activated protein kinase (MAPK)/extracellular-signal regulated kinase (ERK) and phosphatidyl-inositol-3-kinase (PI3K) signalling. Interaction of Gab family proteins with these signalling proteins determines strength, duration and localization of active signalling cascades. However, the underlying molecular mechanisms of signal orchestration by Gab family proteins in IL-6-induced signalling are only scarcely understood. Methods We performed kinetic analyses of interleukin-6 (IL-6)-induced MAPK activation and analysed downstream responses. We compared signalling in wild-type cells, Gab1 knock-out cells, those reconstituted to express Gab1 mutants, and cells expressing gp130 receptors or receptor mutants. Results Interleukin-6-induced MAPK pathway activation can be sub-divided into an early Gab1-independent and a subsequent Gab1-dependent phase. Early Gab1-independent MAPK activation is critical for the subsequent initiation of Gab1-dependent amplification of MAPK pathway activation and requires binding of SH2 domain-containing phosphatase 2 (SHP2) to the interleukin-6 receptor complex. Subsequent and coordinated recruitment of Grb2 and SHP2 to Gab1 is essential for Gab1-dependent amplification of IL-6-induced late MAPK pathway activation and subsequent gene expression. Conclusions Overall, we elaborated the molecular requirements for Gab1-dependent, spatiotemporal orchestration of interleukin-6-dependent MAPK signalling. We discriminated IL-6-induced Gab1-independent, early activation of MAPK signalling and Gab1-dependent, sustained activation of MAPK signalling.

scholarly journals Molecular mechanism and functional implications of thrombin-mediated tyrosine phosphorylation of PKCδ in platelets

Blood ◽  
2005 ◽  
Vol 106 (2) ◽  
pp. 550-557 ◽  
Author(s):  
Swaminathan Murugappan ◽  
Haripriya Shankar ◽  
Surya Bhamidipati ◽  
Robert T. Dorsam ◽  
Jianguo Jin ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Molecular Mechanisms ◽  
Kinase Inhibitors ◽  
Thromboxane A2 ◽  
Human Platelets ◽  
Time Dependent ◽  
Dependent Manner ◽  
Src Tyrosine Kinase ◽  
Functional Implications

Abstract Thrombin has been known to cause tyrosine phosphorylation of protein kinase C δ (PKCδ) in platelets, but the molecular mechanisms and function of this tyrosine phosphorylation is not known. In this study, we investigated the signaling pathways used by protease-activated receptors (PARs) to cause tyrosine phosphorylation of PKCδ and the role of this event in platelet function. PKCδ was tyrosine phosphorylated by either PAR1 or PAR4 in a concentration- and time-dependent manner in human platelets. In particular, the tyrosine 311 residue was phosphorylated downstream of PAR receptors. Also the tyrosine phosphorylation of PKCδ did not occur in Gαq-deficient mouse platelets and was inhibited in the presence of a phospholipase C (PLC) inhibitor U73122 and calcium chelator BAPTA (5,5′-dimethyl-bis(o-aminophenoxy)ethane-N, N, N ′, N ′-tetraacetic acid), suggesting a role for Gαq pathways and calcium in this event. Both PAR1 and PAR4 caused a time-dependent activation of Src (pp60c-src) tyrosine kinase and Src tyrosine kinase inhibitors completely blocked the tyrosine phosphorylation of PKCδ. Inhibition of tyrosine phosphorylation or the kinase activity of PKCδ dramatically blocked PAR-mediated thromboxane A2 generation. We conclude that thrombin causes tyrosine phosphorylation of PKCδ in a calcium- and Src-family kinase–dependent manner in platelets, with functional implications in thromboxane A2 generation.

scholarly journals Live tracking of inter-organ communication by endogenous exosomes in vivo

2018 ◽  
Author(s):  
Frederik J Verweij ◽  
Celine Revenu ◽  
Guillaume Arras ◽  
Florent Dingli ◽  
Damarys Loew ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Extracellular Vesicles ◽  
Molecular Mechanisms ◽  
Scavenger Receptor ◽  
Model Organisms ◽  
Zebrafish Embryos ◽  
List Type ◽  
Dependent Manner ◽  
Fluorescent Reporter

SUMMARYExtracellular vesicles (EVs) are released by most cell types but the definitive demonstration of their functional relevance remains challenging due to the lack of appropriate model organisms. Here we developed anin vivomodel to study EV physiology by expressing CD63-pHluorin in zebrafish embryos. A combination of microscopy techniques and proteomic analysis allowed us to study the biogenesis, composition, transfer, uptake and fate of individual endogenous EVsin vivo. We identified an exosome population released in a syntenin-dependent manner from the Yolk Syncytial Layer into the blood circulation. These exosomes were specifically captured, endocytosed and degraded by patrolling macrophages and endothelial cells in the Caudal Vein Plexus (CVP) in a scavenger receptor and dynamin-dependent manner. Interference with exosome secretion affected CVP growth, supporting their trophic role. Altogether, our work provides a unique model to track in vivo inter-organ communication by endogenous exosomes at individual vesicle level and high spatio-temporal accuracy.Highlights- Single endogenous EVs can be live-visualized in the whole embryo with CD63-pHluorin- In the YSL, syntenin regulates exosome release into the blood for their propagation- YSL exosomes reach the tail to be taken up by macrophages and endothelial cells- Uptake is scavenger receptor and dynamin-dependent and provides trophic supportBlurbWe propose zebrafish embryos expressing a fluorescent reporter for exosomes as a relevant model organism to live-track production, journey and fate of individual extracellular vesicles in vivo. Our model allows investigation of the composition of EVs and the molecular mechanisms controlling their biogenesis and fate and functions in receiving cells.

scholarly journals Cytotoxicity of atropine to human corneal endothelial cells by inducing mitochondrion-dependent apoptosis

2016 ◽  
Vol 241 (13) ◽  
pp. 1457-1465 ◽  
Author(s):  
Qian Wen ◽  
Ting-Jun Fan ◽  
Cheng-Lei Tian
Keyword(s):  
Corneal Endothelium ◽  
Molecular Mechanisms ◽  
Anticholinergic Drug ◽  
Death Receptor ◽  
Time Dependent ◽  
Dependent Manner ◽  
Plasma Membrane Permeability ◽  
Vitro Model

Atropine, a widely used topical anticholinergic drug, might have adverse effects on human corneas in vivo. However, its cytotoxic effect on human corneal endothelium (HCE) and its possible mechanisms are unclear. Here, we investigated the cytotoxicity of atropine and its underlying cellular and molecular mechanisms using an in vitro model of HCE cells and verified the cytotoxicity using cat corneal endothelium (CCE) in vivo. Our results showed that atropine at concentrations above 0.3125 g/L could induce abnormal morphology and viability decline in a dose- and time-dependent manner in vitro. The cytotoxicity of atropine was proven by the induced density decrease and abnormality of morphology and ultrastructure of CCE cells in vivo. Meanwhile, atropine could also induce dose- and time-dependent elevation of plasma membrane permeability, G1 phase arrest, phosphatidylserine externalization, DNA fragmentation, and apoptotic body formation of HCE cells. Moreover, 2.5 g/L atropine could also induce caspase-2/-3/-9 activation, mitochondrial transmembrane potential disruption, downregulation of anti-apoptotic Bcl-2 and Bcl-xL, upregulation of pro-apoptotic Bax and Bad, and upregulation of cytoplasmic cytochrome c and apoptosis-inducing factor. In conclusion, atropine above 1/128 of its clinical therapeutic dosage has a dose- and time-dependent cytotoxicity to HCE cells in vitro which is confirmed by CCE cells in vivo, and its cytotoxicity is achieved by inducing HCE cell apoptosis via a death receptor-mediated mitochondrion-dependent signaling pathway. Our findings provide new insights into the cytotoxicity and apoptosis-inducing effect of atropine which should be used with great caution in eye clinic.

scholarly journals Dilong: Role in Peripheral Nerve Regeneration

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Yung-Ming Chang ◽  
Wei-Yi Chi ◽  
Tung-Yuan Lai ◽  
Yueh-Sheng Chen ◽  
Fuu-Jen Tsai ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Migration ◽  
Nerve Regeneration ◽  
Schwann Cells ◽  
Molecular Mechanisms ◽  
S Phase ◽  
Time Dependent ◽  
Dependent Manner ◽  
Igf I ◽  
Cell Migration And Proliferation

Dilong, also known as earthworm, has been widely used in traditional Chinese medicine (TCM) for thousands of years. Schwann cell migration and proliferation are critical for the regeneration of injured nerves and Schwann cells provide an essentially supportive role for neuron regeneration. However, the molecular mechanisms of migration and proliferation induced by dilongs in Schwann cells remain unclear. Here, we discuss the molecular mechanisms that includes (i) migration signaling, MAPKs (mitogen-activated protein kinases), mediated PAs and MMP2/9 pathway; (ii) survival and proliferative signaling, IGF-I (insulin-like growth factor-I)-mediated PI3K/Akt pathways and (iii) cell cycle regulation. Dilong stimulate RSC96 cell proliferation and migration. It can induce phosphorylation of ERK1/2 and p38, but not JNK, and activate the downstream signaling expression of PAs (plasminogen activators) and MMPs (matrix metalloproteinases) in a time-dependent manner. In addition, Dilong stimulated ERK1/2 and p38 phosphorylation was attenuated by pretreatment with chemical inhibitors (U0126 and SB203580), and small interfering ERK1/2 and p38 RNA, resulting in migration and uPA-related signal pathway inhibition. Dilong also induces the phosphorylation of IGF-I-mediated PI3K/Akt pathway, activates protein expression of PCNA (proliferating cell nuclear antigen) and cell cycle regulatory proteins (cyclin D1, cyclin E and cyclin A) in a time-dependent manner. In addition, it accelerates G1-phase progression with earlier S-phase entry and significant numbers of cells entered the S-phase. The siRNA-mediated knockdown of PI3K that significantly reduces PI3K protein expression levels, resulting in Bcl2survival factor reduction, revealing a marked blockage of G1to S transition in proliferating cells. These results reveal the unknown RSC96 cell migration and proliferation mechanism induced by dilong, which find use as a new medicine for nerve regeneration.

The Anti-Atherogenic Properties of Sesamin are Mediated via Improved Macrophage Cholesterol Efflux Through PPARγ1-LXRα and MAPK Signaling

2014 ◽  
Vol 84 (1-2) ◽  
pp. 79-91 ◽  
Author(s):  
Amin F. Majdalawieh ◽  
Hyo-Sung Ro
Keyword(s):  
Cholesterol Efflux ◽  
Transcriptional Activity ◽  
Molecular Mechanisms ◽  
Foam Cell ◽  
Mapk Signaling ◽  
Luciferase Reporter ◽  
Foam Cell Formation ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Macrophage Cholesterol Efflux

Background: Foam cell formation resulting from disrupted macrophage cholesterol efflux, which is triggered by PPARγ1 and LXRα, is a hallmark of atherosclerosis. Sesamin and sesame oil exert anti-atherogenic effects in vivo. However, the exact molecular mechanisms underlying such effects are not fully understood. Aim: This study examines the potential effects of sesamin (0, 25, 50, 75, 100 μM) on PPARγ1 and LXRα expression and transcriptional activity as well as macrophage cholesterol efflux. Methods: PPARγ1 and LXRα expression and transcriptional activity are assessed by luciferase reporter assays. Macrophage cholesterol efflux is evaluated by ApoAI-specific cholesterol efflux assays. Results: The 50 μM, 75 μM, and 100 μM concentrations of sesamin up-regulated the expression of PPARγ1 (p< 0.001, p < 0.001, p < 0.001, respectively) and LXRα (p = 0.002, p < 0.001, p < 0.001, respectively) in a concentration-dependent manner. Moreover, 75 μM and 100 μM concentrations of sesamin led to 5.2-fold (p < 0.001) and 6.0-fold (p<0.001) increases in PPAR transcriptional activity and 3.9-fold (p< 0.001) and 4.2-fold (p < 0.001) increases in LXR transcriptional activity, respectively, in a concentration- and time-dependent manner via MAPK signaling. Consistently, 50 μM, 75 μM, and 100 μM concentrations of sesamin improved macrophage cholesterol efflux by 2.7-fold (p < 0.001), 4.2-fold (p < 0.001), and 4.2-fold (p < 0.001), respectively, via MAPK signaling. Conclusion: Our findings shed light on the molecular mechanism(s) underlying sesamin’s anti-atherogenic effects, which seem to be due, at least in part, to its ability to up-regulate PPARγ1 and LXRα expression and transcriptional activity, improving macrophage cholesterol efflux. We anticipate that sesamin may be used as a therapeutic agent for treating atherosclerosis.

Neuroblastoma: An Updated Review on Biology and Treatment

2020 ◽  
Vol 20 (13) ◽  
pp. 1014-1022 ◽  
Author(s):  
Suresh Mallepalli ◽  
Manoj Kumar Gupta ◽  
Ramakrishna Vadde
Keyword(s):  
Survival Rate ◽  
High Risk ◽  
Molecular Mechanisms ◽  
Definitive Treatment ◽  
Therapeutic Drug ◽  
Mycn Amplification ◽  
Dependent Manner ◽  
High Risk Patients ◽  
Treatment And Prevention ◽  
Risk Patients

Background: Neuroblastoma (NB) is the second leading extracranial solid tumors of early childhood and clinically characterized by the presence of round, small, monomorphic cells with excess nuclear pigmentation (hyperchromasia).Owing to a lack of definitive treatment against NB and less survival rate in high-risk patients, there is an urgent requirement to understand molecular mechanisms associated with NB in a better way, which in turn can be utilized for developing drugs towards the treatment of NB in human. Objectives: In this review, an approach was adopted to understand major risk factors, pathophysiology, the molecular mechanism associated with NB, and various therapeutic agents that can serve as drugs towards the treatment of NB in humans. Conclusions: Numerous genetic (e.g., MYCN amplification), perinatal, and gestational factors are responsible for developing NB. However, no definite environmental or parental exposures responsible for causing NB have been confirmed to date. Though intensive multimodal treatment approaches, namely, chemotherapy, surgery &radiation, may help in improving the survival rate in children, these approaches have several side effects and do not work efficiently in high-risk patients. However, recent studies suggested that numerous phytochemicals, namely, vincristine, and matrine have a minimal side effect in the human body and may serve as a therapeutic drug during the treatment of NB. Most of these phytochemicals work in a dose-dependent manner and hence must be prescribed very cautiously. The information discussed in the present review will be useful in the drug discovery process as well as treatment and prevention on NB in humans.

Pisosterol Induces G2/M Cell Cycle Arrest and Apoptosis via the ATM/ATR Signaling Pathway in Human Glioma Cells

2020 ◽  
Vol 20 (6) ◽  
pp. 734-750
Author(s):  
Wallax A.S. Ferreira ◽  
Rommel R. Burbano ◽  
Claudia do Ó. Pessoa ◽  
Maria L. Harada ◽  
Bárbara do Nascimento Borges ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Signaling Pathway ◽  
Glioma Cell ◽  
Molecular Mechanisms ◽  
Glioma Cells ◽  
Dependent Manner ◽  
M Cell ◽  
Trypan Blue Exclusion ◽  
Cycle Arrest

Background: Pisosterol, a triterpene derived from Pisolithus tinctorius, exhibits potential antitumor activity in various malignancies. However, the molecular mechanisms that mediate the pisosterol-specific effects on glioma cells remain unknown. Objective: This study aimed to evaluate the antitumoral effects of pisosterol on glioma cell lines. Methods: The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and trypan blue exclusion assays were used to evaluate the effect of pisosterol on cell proliferation and viability in glioma cells. The effect of pisosterol on the distribution of the cells in the cell cycle was performed by flow cytometry. The expression and methylation pattern of the promoter region of MYC, ATM, BCL2, BMI1, CASP3, CDK1, CDKN1A, CDKN2A, CDKN2B, CHEK1, MDM2, p14ARF and TP53 was analyzed by RT-qPCR, western blotting and bisulfite sequencing PCR (BSP-PCR). Results: Here, it has been reported that pisosterol markedly induced G2/M arrest and apoptosis and decreased the cell viability and proliferation potential of glioma cells in a dose-dependent manner by increasing the expression of ATM, CASP3, CDK1, CDKN1A, CDKN2A, CDKN2B, CHEK1, p14ARF and TP53 and decreasing the expression of MYC, BCL2, BMI1 and MDM2. Pisosterol also triggered both caspase-independent and caspase-dependent apoptotic pathways by regulating the expression of Bcl-2 and activating caspase-3 and p53. Conclusions: It has been, for the first time, confirmed that the ATM/ATR signaling pathway is a critical mechanism for G2/M arrest in pisosterol-induced glioma cell cycle arrest and suggests that this compound might be a promising anticancer candidate for further investigation.

The Natural Flavonoid Naringenin Inhibits the Cell Growth of WilmsTumorinChildren by Suppressing TLR4/NF-κB Signaling

2020 ◽  
Vol 20 ◽  
Author(s):  
Hongtao Li ◽  
Peng Chen ◽  
Lei Chen ◽  
Xinning Wang
Keyword(s):  
Cell Growth ◽  
Western Blot ◽  
Wilms Tumor ◽  
Critical Role ◽  
Time Dependent ◽  
Luciferase Assay ◽  
Dependent Manner ◽  
Tlr4 Expression ◽  
Protein Levels

Background: Nuclear factor kappa B (NF-κB) is usually activated in Wilms tumor (WT) cells and plays a critical role in WT development. Objective: The study purpose was to screen a NF-κB inhibitor from natural product library and explore its effects on WT development. Methods: Luciferase assay was employed to assess the effects of natural chemical son NF-κB activity. CCK-8 assay was conducted to assess cell growth in response to naringenin. WT xenograft model was established to analyze the effect of naringenin in vivo. Quantitative real-time PCR and Western blot were performed to examine the mRNA and protein levels of relative genes, respectively. Results: Naringenin displayed significant inhibitory effect on NF-κB activation in SK-NEP-1 cells. In SK-NEP-1 and G-401 cells, naringenin inhibited p65 phosphorylation. Moreover, naringenin suppressed TNF-α-induced p65 phosphorylation in WT cells. Naringenin inhibited TLR4 expression at both mRNA and protein levels in WT cells. CCK-8 staining showed that naringenin inhibited cell growth of the two above WT cells in dose-and time-dependent manner, whereas Toll-like receptor 4 (TLR4) over expression partially reversed the above phenomena. Besides, naringenin suppressed WT tumor growth in dose-and time-dependent manner in vivo. Western blot found that naringenin inhibited TLR4 expression and p65 phosphorylation in WT xenograft tumors. Conclusion: Naringenin inhibits WT development viasuppressing TLR4/NF-κB signaling

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