scholarly journals Nuclear localization of platelet-activating factor receptor controls retinal neovascularization

2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Vikrant K Bhosle ◽  
José Carlos Rivera ◽  
Tianwei (Ellen) Zhou ◽  
Samy Omri ◽  
Melanie Sanchez ◽  
...  
Keyword(s):  
Nuclear Localization ◽  
Cellular Localization ◽  
Nuclear Translocation ◽  
Ex Vivo ◽  
Platelet Activating Factor ◽  
Plasma Membrane Permeability ◽  
Independent Manner ◽  
Endothelial Growth Factor

Abstract Platelet-activating factor (PAF) is a pleiotropic phospholipid with proinflammatory, procoagulant and angiogenic actions on the vasculature. We and others have reported the presence of PAF receptor (Ptafr) at intracellular sites such as the nucleus. However, mechanisms of localization and physiologic functions of intracellular Ptafr remain poorly understood. We hereby identify the importance of C-terminal motif of the receptor and uncover novel roles of Rab11a GTPase and importin-5 in nuclear translocation of Ptafr in primary human retinal microvascular endothelial cells. Nuclear localization of Ptafr is independent of exogenous PAF stimulation as well as intracellular PAF biosynthesis. Moreover, nuclear Ptafr is responsible for the upregulation of unique set of growth factors, including vascular endothelial growth factor, in vitro and ex vivo. We further corroborate the intracrine PAF signaling, resulting in angiogenesis in vivo, using Ptafr antagonists with distinct plasma membrane permeability. Collectively, our findings show that nuclear Ptafr translocates in an agonist-independent manner, and distinctive functions of Ptafr based on its cellular localization point to another dimension needed for pharmacologic selectivity of drugs.

scholarly journals Identification of a novel actin-dependent signal transducing module allows for the targeted degradation of GLI1

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Philipp Schneider ◽  
Juan Miguel Bayo-Fina ◽  
Rajeev Singh ◽  
Pavan Kumar Dhanyamraju ◽  
Philipp Holz ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Down Syndrome ◽  
Nuclear Localization ◽  
Transcription Factor Activity ◽  
Factor Activity ◽  
Independent Manner ◽  
Small Molecule Antagonist ◽  
Dependent Signal

Abstract The Down syndrome-associated DYRK1A kinase has been reported as a stimulator of the developmentally important Hedgehog (Hh) pathway, but cells from Down syndrome patients paradoxically display reduced Hh signalling activity. Here we find that DYRK1A stimulates GLI transcription factor activity through phosphorylation of general nuclear localization clusters. In contrast, in vivo and in vitro experiments reveal that DYRK1A kinase can also function as an inhibitor of endogenous Hh signalling by negatively regulating ABLIM proteins, the actin cytoskeleton and the transcriptional co-activator MKL1 (MAL). As a final effector of the DYRK1A-ABLIM-actin-MKL1 sequence, we identify the MKL1 interactor Jumonji domain demethylase 1A (JMJD1A) as a novel Hh pathway component stabilizing the GLI1 protein in a demethylase-independent manner. Furthermore, a Jumonji-specific small-molecule antagonist represents a novel and powerful inhibitor of Hh signal transduction by inducing GLI1 protein degradation in vitro and in vivo.

scholarly journals Sodium Stibogluconate (Pentostam) Potentiates Oxidant Production in Murine Visceral Leishmaniasis and in Human Blood

2000 ◽  
Vol 44 (9) ◽  
pp. 2406-2410 ◽  
Author(s):  
Samira Rais ◽  
Axel Perianin ◽  
Monique Lenoir ◽  
Abderrahim Sadak ◽  
Daniele Rivollet ◽  
...  
Keyword(s):  
Human Blood ◽  
Ex Vivo ◽  
Platelet Activating Factor ◽  
Sodium Stibogluconate ◽  
Potentiation Effect ◽  
Normal Human ◽  
Ros Formation ◽  
Oxidant Production

ABSTRACT Sodium stibogluconate (Sbb), a leishmanicidal drug, was studied for its in vivo effect on the formation of reactive oxygen species (ROS), assessed by chemiluminescence (CL) in the whole blood of mice infected with Leishmania infantum. Stimulation of ROS formation induced ex vivo by zymosan particles or the protein kinase C activator phorbol myristate acetate (PMA) was reduced by approximately 25% (P < 0.05) after infection of mice. Treatment of infected mice with Sbb (50 to 400 mg/kg of body weight) enhanced the blood CL induced by zymosan and PMA (47 to 96%, P < 0.01). The drug potentiation effect also occurred in uninfected mice. In vitro treatment of normal human blood with Sbb (1, 10, or 100 μg/ml) for 1 h primed the CL response to PMA (29 to 54%). The priming effect of Sbb was also observed on the production of superoxide by isolated polymorphonuclear leukocytes stimulated either by PMA and zymosan or by the chemoattractants N-formyl-Met-Leu-Phe and platelet-activating factor. These data provide the first evidence of priming of the phagocyte respiratory burst by Sbb. This novel property of Sbb may contribute to the drug's leishmanicidal effect.

scholarly journals Biological significance of monoallelic and biallelic BIRC3 loss in del(11q) chronic lymphocytic leukemia progression

2021 ◽  
Vol 11 (7) ◽  
Author(s):  
Miguel Quijada-Álamo ◽  
María Hernández-Sánchez ◽  
Ana-Eugenia Rodríguez-Vicente ◽  
Claudia Pérez-Carretero ◽  
Alberto Rodríguez-Sánchez ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Nuclear Translocation ◽  
Ex Vivo ◽  
Biological Significance ◽  
Xenograft Model ◽  
Underlying Disease ◽  
Lymphocytic Leukemia ◽  
Enhanced Sensitivity

AbstractBIRC3 is monoallelically deleted in up to 80% of chronic lymphocytic leukemia (CLL) cases harboring del(11q). In addition, truncating mutations in the remaining allele of this gene can lead to BIRC3 biallelic inactivation, which has been shown to be a marker for reduced survival in CLL. Nevertheless, the biological mechanisms by which these lesions could contribute to del(11q) CLL pathogenesis and progression are partially unexplored. We implemented the CRISPR/Cas9-editing system to generate isogenic CLL cell lines harboring del(11q) and/or BIRC3 mutations, modeling monoallelic and biallelic BIRC3 loss. Our results reveal that monoallelic BIRC3 deletion in del(11q) cells promotes non-canonical NF-κB signaling activation via RelB-p52 nuclear translocation, being these effects allelic dose-dependent and therefore further enhanced in del(11q) cells with biallelic BIRC3 loss. Moreover, we demonstrate ex vivo in primary cells that del(11q) cases including BIRC3 within their deleted region show evidence of non-canonical NF-κB activation which correlates with high BCL2 levels and enhanced sensitivity to venetoclax. Furthermore, our results show that BIRC3 mutations in del(11q) cells promote clonal advantage in vitro and accelerate leukemic progression in an in vivo xenograft model. Altogether, this work highlights the biological bases underlying disease progression of del(11q) CLL patients harboring BIRC3 deletion and mutation.

scholarly journals DKK3 (Dikkopf-3) Transdifferentiates Fibroblasts Into Functional Endothelial Cells—Brief Report

2019 ◽  
Vol 39 (4) ◽  
pp. 765-773 ◽  
Author(s):  
Ting Chen ◽  
Eirini Karamariti ◽  
Xuechong Hong ◽  
Jiacheng Deng ◽  
Yutao Wu ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Ex Vivo ◽  
Human Fibroblasts ◽  
Defined Media ◽  
Mesenchymal To Epithelial Transition ◽  
Potential Strategy ◽  
Underlying Mechanisms ◽  
Endothelial Growth Factor

Objective— To determine the role of a cytokine-like protein DKK3 (dikkopf-3) in directly transdifferentiating fibroblasts into endothelial cells (ECs) and the underlying mechanisms. Approach and Results— DKK3 overexpression in human fibroblasts under defined conditions for 4 days led to a notable change in cell morphology and progenitor gene expression. It was revealed that these cells went through mesenchymal-to-epithelial transition and subsequently expressed KDR (kinase insert domain receptor) at high levels. Further culture in EC defined media led to differentiation of these progenitors into functional ECs capable of angiogenesis both in vitro and in vivo, which was regulated by the VEGF (vascular endothelial growth factor)/miR (microRNA)-125a-5p/Stat3 (signal transducer and activator of transcription factor 3) axis. More importantly, fibroblast-derived ECs showed the ability to form a patent endothelium-like monolayer in tissue-engineered vascular grafts ex vivo. Conclusions— These data demonstrate that DKK3 is capable of directly differentiating human fibroblasts to functional ECs under defined media and provides a novel potential strategy for endothelial regeneration.

scholarly journals Spatial and temporal VEGF receptor intracellular trafficking in microvascular and macrovascular endothelial cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Juliete A. F. Silva ◽  
Xiaoping Qi ◽  
Maria B. Grant ◽  
Michael E. Boulton
Keyword(s):  
Endothelial Cells ◽  
Nuclear Translocation ◽  
Vascular Endothelial Cells ◽  
Vegf Receptor ◽  
Vascular Endothelial ◽  
Intracellular Organelles ◽  
Endosomal Pathway ◽  
Endothelial Growth Factor

AbstractThe vascular endothelial growth factor receptors (VEGFRs) can shape the neovascular phenotype of vascular endothelial cells when translocated to the nucleus, however the spatial and temporal changes in the intracellular distribution and translocation of VEGFRs to the nucleus and the organelles involved in this process is unclear. This study reports the effect of exogenous VEGF on translocation of VEGFRs and organelles in micro- and macrovascular endothelial cells. We showed that VEGF is responsible for: a rapid and substantial nuclear translocation of VEGFRs; VEGFR1 and VEGFR2 exhibit distinct spatial, temporal and structural translocation characteristics both in vitro and in vivo and this determines the nuclear VEGFR1:VEGFR2 ratio which differs between microvascular and macrovascular cells; VEGFR2 nuclear translocation is associated with the endosomal pathway transporting the receptor from Golgi in microvascular endothelial cells; and an increase in the volume of intracellular organelles. In conclusion, the nuclear translocation of VEGFRs is both receptor and vessel (macro versus micro) dependent and the endosomal pathway plays a key role in the translocation of VEGFRs to the nucleus and the subsequent export to the lysosomal system. Modulating VEGF-mediated VEGFR1 and VEGFR2 intracellular transmigration pathways may offer an alternative for the development of new anti-angiogenic therapies.

A Novel Approach of Synthesizing and Evaluating the Anticancer Potential of Silver Oxide Nanoparticles in vitro

Chemotherapy ◽  
2017 ◽  
Vol 62 (5) ◽  
pp. 279-289 ◽  
Author(s):  
Kaushik Banerjee ◽  
Satyajit Das ◽  
Pritha Choudhury ◽  
Sarbari Ghosh ◽  
Rathindranath Baral ◽  
...  
Keyword(s):  
Cell Lines ◽  
Cellular Localization ◽  
Silver Oxide ◽  
Nuclear Translocation ◽  
Ex Vivo ◽  
Oxide Nanoparticles ◽  
Malignant Cells ◽  
Limited Information ◽  
Silver Oxide Nanoparticles

Background: Development of novel strategies to kill cancer by sparing normal cells is of utmost importance. Apart from their known antimicrobial activity, only limited information has been recorded regarding the antitumor potential of biocompatible silver oxide nanoparticles (AgONPs). There is a need to evaluate the anticancer potential of biocompatible AgONPs in vitro. Methods: A new approach of utilizing the leaf extract of Excoecaria agallocha was used to synthesize AgONPs. This was then characterized by ultraviolet-visible spectrophotometry, nanoparticle-tracking analysis, and ζ-potential analysis. Cytotoxicity and apoptotic potential were evaluated with an MTT assay and an annexin V-binding assay against the murine melanoma (B16F10), murine colon cancer (CT26), murine lung adenocarcinoma (3LL), and murine Ehrlich ascites carcinoma (EAC) cell lines. Cellular localization of AgONPs was evaluated on fluorescence microscopy. Results: UV peaks at 270 and 330 nm indicated the formation of nanoparticles (NPs) and the NP-tracking analyzer revealed them to have a size of 228 nm. AgONPs exerted initial cytotoxicity, specifically against all the experimental malignant cells by sparing the normal cell lines. Moreover, AgONPs exert apoptosis equally on all the malignant cells in vitro and ex vivo. This cytotoxicity possibly occurs via the nuclear translocation of AgONPs as analyzed in B16F10 cells. Conclusions: AgONPs utilizing natural sources would be a new medicinal approach against a broad spectrum of malignancy.

scholarly journals Dynamic patterns of YAP1 expression and cellular localization in the developing and injured utricle

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Vikrant Borse ◽  
Matthew Barton ◽  
Harry Arndt ◽  
Tejbeer Kaur ◽  
Mark E. Warchol
Keyword(s):  
Inner Ear ◽  
Cellular Localization ◽  
Nuclear Translocation ◽  
Hippo Pathway ◽  
Hippo Signaling ◽  
Supporting Cells ◽  
The Hippo Pathway

AbstractThe Hippo signaling pathway is a key regulator of tissue development and regeneration. Activation of the Hippo pathway leads to nuclear translocation of the YAP1 transcriptional coactivator, resulting in changes in gene expression and cell cycle entry. Recent studies have demonstrated the nuclear translocation of YAP1 during the development of the sensory organs of the inner ear, but the possible role of YAP1 in sensory regeneration of the inner ear is unclear. The present study characterized the cellular localization of YAP1 in the utricles of mice and chicks, both under normal conditions and after HC injury. During neonatal development, YAP1 expression was observed in the cytoplasm of supporting cells, and was transiently expressed in the cytoplasm of some differentiating hair cells. We also observed temporary nuclear translocation of YAP1 in supporting cells of the mouse utricle after short periods in organotypic culture. However, little or no nuclear translocation of YAP1 was observed in the utricles of neonatal or mature mice after ototoxic injury. In contrast, substantial YAP1 nuclear translocation was observed in the chicken utricle after streptomycin treatment in vitro and in vivo. Together, these data suggest that differences in YAP1 signaling may partially account for the differing regenerative abilities of the avian vs. mammalian inner ear.

The Role of Polyphenols in the Modulation of Plasma Non-Enzymatic Antioxidant Capacity (NEAC)

2012 ◽  
Vol 82 (3) ◽  
pp. 228-232 ◽  
Author(s):  
Mauro Serafini ◽  
Giuseppa Morabito
Keyword(s):  
Antioxidant Capacity ◽  
Dietary Intervention ◽  
Ex Vivo ◽  
The Body ◽  
Dietary Polyphenols ◽  
Enzymatic Antioxidant ◽  
Endogenous Antioxidant

Dietary polyphenols have been shown to scavenge free radicals, modulating cellular redox transcription factors in different in vitro and ex vivo models. Dietary intervention studies have shown that consumption of plant foods modulates plasma Non-Enzymatic Antioxidant Capacity (NEAC), a biomarker of the endogenous antioxidant network, in human subjects. However, the identification of the molecules responsible for this effect are yet to be obtained and evidences of an antioxidant in vivo action of polyphenols are conflicting. There is a clear discrepancy between polyphenols (PP) concentration in body fluids and the extent of increase of plasma NEAC. The low degree of absorption and the extensive metabolism of PP within the body have raised questions about their contribution to the endogenous antioxidant network. This work will discuss the role of polyphenols from galenic preparation, food extracts, and selected dietary sources as modulators of plasma NEAC in humans.

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