Abstract 1454: Differentiated Cardiomyocytes Divide in Response to Neuregulin1 by Disassembling The Contractile Apparatus

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Bernhard Kuhn ◽  
Kevin Bersell ◽  
Salvatore Mancarella ◽  
Shima Arab
Keyword(s):  
Cell Cycle ◽  
Rhode Island ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Prenatal Development ◽  
Live Cell ◽  
Tyrosine Kinase Receptor ◽  
Cell Cycle Reentry

Introduction: Cardiomyocytes carry the pump function of the heart. What molecular and cellular mechanisms control proliferation of cardiomyocytes is an unresolved question with high impact on regenerative medicine. Hypothesis: The growth factor neuregulin1 (NRG1) and its tyrosine kinase receptor ErbB4 control cardiomyocyte proliferation during prenatal development. NRG1 and ErbB4 are expressed in the adult heart. We hypothesized that activating NRG1 signaling stimulates cell cycle reentry and division of a subpopulation of differentiated cardiomyocytes. Methods: We determined cardiomyocyte cell cycle reentry and division in vitro using immunofluorescence microscopy and live cell imaging as read-out assays. We tested the in vivo proliferative effect of controlling NRG1 signaling at the level of its receptor using inducible cardiomyocyte-specific ErbB4 knockout mice and ErbB4 transgenic mice. Results: NRG1 induced cell cycle reentry of large, striated, and rod-shaped cardiomyocytes that express cardiac contractile proteins, consistent with a differentiated phenotype. Live cell imaging demonstrated in real time that NRG1 induces differentiated cardiomyocytes to undergo karyokinesis (nuclear division) and cytokinesis (cytoplasmic division), followed by separation into two differentiated daughter cardiomyocytes. During cell division, cardiomyocytes disassembled their contractile fibrils in the regions of the mitotic spindle and the cleavage furrow. NRG1 induced karyokinesis in 33% of mononucleated and in 1% of binucleated cardiomyocytes. Mononucleated cardiomyocytes completed cytokinesis, while binucleated cardiomyocytes did not. In vivo, postnatal genetic inactivation of the NRG1 receptor ErbB4 reduced cycling of differentiated mononucleated cardiomyocytes (Ctr. 5% vs. ko 0%, P < 0.01). In contrast, transgenic expression of ErbB4 increased cycling of differentiated mononucleated cardiomyocytes (Ctr. 7.2% vs. tg 22.6%, P < 0.05). Conclusions: ErbB4 is required and NRG1 and ErbB4 are sufficient to induce proliferation of a subpopulation of differentiated cardiomyocytes. NRG1 and the pathway that it regulates may provide new therapeutic targets to enhance mammalian cardiac regeneration. This research has received full or partial funding support from the American Heart Association, AHA Founders Affiliate (Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island, Vermont).

A new visible-light-excitable ICT-CHEF-mediated fluorescence ‘turn-on’ probe for the selective detection of Cd2+ in a mixed aqueous system with live-cell imaging

2015 ◽  
Vol 44 (12) ◽  
pp. 5763-5770 ◽  
Author(s):  
Shyamaprosad Goswami ◽  
Krishnendu Aich ◽  
Sangita Das ◽  
Chitrangada Das Mukhopadhyay ◽  
Deblina Sarkar ◽  
...  
Keyword(s):  
Visible Light ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Aqueous System ◽  
Live Cell ◽  
Selective Detection ◽  
Turn On ◽  
Fluorescence Turn On

A new quinoline based sensor was developed and applied for the selective detection of Cd2+ both in vitro and in vivo.

scholarly journals Long-term fate of etoposide-induced micronuclei and micronucleated cells in Hela-H2B-GFP cells

2020 ◽  
Vol 94 (10) ◽  
pp. 3553-3561
Author(s):  
Hauke Reimann ◽  
Helga Stopper ◽  
Henning Hintzsche
Keyword(s):  
Cell Cycle ◽  
Cell Death ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Live Cell ◽  
Cellular Structures ◽  
Death Rates ◽  
Daughter Cells

Abstract Micronuclei are small nuclear cellular structures containing whole chromosomes or chromosomal fragments. While there is a lot of information available about the origin and formation of micronuclei, less is known about the fate of micronuclei and micronucleated cells. Possible fates include extrusion, degradation, reincorporation and persistence. Live cell imaging was performed to quantitatively analyse the fates of micronuclei and micronucleated cells occurring in vitro. Imaging was conducted for up to 96 h in HeLa-H2B-GFP cells treated with 0.5, 1 and 2 µg/ml etoposide. While a minority of micronuclei was reincorporated into the main nucleus during mitosis, the majority of micronuclei persisted without any alterations. Degradation and extrusion were observed rarely or never. The presence of micronuclei affected the proliferation of the daughter cells and also had an influence on cell death rates. Mitotic errors were found to be clearly increased in micronucleus-containing cells. The results show that micronuclei and micronucleated cells can, although delayed in cell cycle, sustain for multiple divisions.

CBIO-17. A NOVEL ROLE FOR ATR KINASE DETERMINES GLIOBLASTOMA TUMOUR CELL INVASION

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi30-vi30
Author(s):  
ross carruthers ◽  
Sarah Derby ◽  
Karen Strathdee ◽  
Anthony Chalmers ◽  
Jim Norman ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cell Invasion ◽  
Tumour Cell ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Live Cell ◽  
Tumour Cell Invasion ◽  
Atr Kinase

Abstract BACKGROUND: Widespread contamination of the brain with malignant cells is a predominant feature of glioblastoma (GBM) and fatal brainstem infiltration is frequently observed at autopsy. Whilst radiotherapy improves survival, irradiation increases GBM cell invasion, resulting in sublethal dose to cells migrating outside the irradiated volume. Tumour cell invasion should be a therapeutic priority if survival is to be improved. The responsible molecular mechanisms are key to improving outcomes but remain enigmatic. Ataxia telangiectasia and rad3-related (ATR) is a DNA damage response (DDR) kinase involved in DNA replication stress (RS) response and is an established therapeutic target for GBM. In this study we demonstrate a novel role for ATR kinase in facilitating malignant cell invasion. METHODS AND RESULTS: Invading margins of human GBM samples demonstrated increased pATR expression relative to core. Live cell imaging demonstrated a reduction in cell velocity following ATR inhibition (ATRi; VE822) or ATR siRNA, and a retraction defect was evident in vitro. Extensive cytoplasmic vacuolation occurred following ATRi or siRNA which were single walled structures on electron microscopy which could engulf high molecular weight dextran, suggesting blockade of macropinosome processing. Live cell imaging with GFP-integrin α5 and integrin recycling assays showed integrin sequestration within macropinosomes and reduced integrin internalisation respectively. Interrogation of a published ‘ATR interactome’ revealed ATR targets with functions in endocytic vesicle trafficking. Intravital in vivo imaging of murine xenograft tumours confirmed vacuolation and dextran uptake following ATRi, whilst a further study demonstrated reduced invading tumour cells following ATRi in intracranial xenografts. CONCLUSION: We demonstrate a novel role for ATR in facilitating macropinocytic vesicle trafficking and integrin internalisation. ATRi results in a profound motility defect in vitro and in vivo. ATR inhibitors are entering early phase trials as radiation sensitisers and we propose that therapeutic benefit will extend beyond DNA damage potentiation.

A quinoline-based probe for effective and selective sensing of aspartic acid in aqueous medium: in vitro and in vivo live cell imaging

2019 ◽  
Vol 6 (11) ◽  
pp. 3237-3244 ◽  
Author(s):  
C. Elamathi ◽  
R. J. Butcher ◽  
A. Mohankumar ◽  
P. Sundararaj ◽  
A. Madankumar ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Aspartic Acid ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Live Cell ◽  
C Elegans ◽  
Highly Sensitive ◽  
Mcf 7

A highly sensitive and selective “on–off–on” chemosensor for aspartic acid in aqueous solution was established. In vitro live cell imaging against MCF 7 cells and in vivo imaging using C. elegans were successfully demonstrated.

FRET based ‘red-switch’ for Al3+ over ESIPT based ‘green-switch’ for Zn2+: dual channel detection with live-cell imaging on a dyad platform

RSC Advances ◽  
2014 ◽  
Vol 4 (65) ◽  
pp. 34572-34576 ◽  
Author(s):  
Shyamaprosad Goswami ◽  
Abhishek Manna ◽  
Sima Paul ◽  
Anup Kumar Maity ◽  
Partha Saha ◽  
...  
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Live Cell ◽  
Channel Detection ◽  
Dual Channel

Our designed chemosensor, rhodamine-HBT-dyad (RHD), selectively detects two biologically important ions (Al3+ and Zn2+) at two different wavelengths (red and green, respectively) through FRET and ESIPT in vitro and in vivo.

scholarly journals Live-cell imaging with Aspergillus fumigatus-specific fluorescent siderophore conjugates

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Joachim Pfister ◽  
Alexander Lichius ◽  
Dominik Summer ◽  
Hubertus Haas ◽  
Thines Kanagasundaram ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Fluorescent Dyes ◽  
Iron Acquisition ◽  
Live Cell ◽  
Subcellular Localisation ◽  
Gallium 68

Abstract Live-cell imaging allows the in vivo analysis of subcellular localisation dynamics of physiological processes with high spatial–temporal resolution. However, only few fluorescent dyes have been custom-designed to facilitate species-specific live-cell imaging approaches in filamentous fungi to date. Therefore, we developed fluorescent dye conjugates based on the sophisticated iron acquisition system of Aspergillus fumigatus by chemical modification of the siderophore triacetylfusarinine C (TAFC). Various fluorophores (FITC, NBD, Ocean Blue, BODIPY 630/650, SiR, TAMRA and Cy5) were conjugated to diacetylfusarinine C (DAFC). Gallium-68 labelling enabled in vitro and in vivo characterisations. LogD, uptake assays and growth assays were performed and complemented by live-cell imaging in different Aspergillus species. Siderophore conjugates were specifically recognised by the TAFC transporter MirB and utilized as an iron source in growth assays. Fluorescence microscopy revealed uptake dynamics and differential subcellular accumulation patterns of all compounds inside fungal hyphae.[Fe]DAFC-NBD and -Ocean Blue accumulated in vacuoles, whereas [Fe]DAFC-BODIPY, -SiR and -Cy5 localised to mitochondria. [Fe]DAFC -FITC showed a uniform cytoplasmic distribution, whereas [Fe]DAFC-TAMRA was not internalised at all. Co-staining experiments with commercially available fluorescent dyes confirmed these findings. Overall, we developed a new class of fluorescent dyes that vary in intracellular fungal targeting , thereby providing novel tools for live-cell imaging applications for Aspergillus fumigatus.

Intact Doxil is taken up intracellularly and released doxorubicin sequesters in the lysosome: Evaluated by in vitro / in vivo live cell imaging

2013 ◽  
Vol 172 (1) ◽  
pp. 330-340 ◽  
Author(s):  
Ann L.B. Seynhaeve ◽  
Bilyana M. Dicheva ◽  
Saske Hoving ◽  
Gerben A. Koning ◽  
Timo L.M. ten Hagen
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Live Cell

scholarly journals Roles for tubulin recruitment and self-organization by TOG domain arrays in Microtubule plus-end tracking and polymerase

2018 ◽  
Author(s):  
Brian Cook ◽  
Fred Chang ◽  
Ignacio Flor-Parra ◽  
Jawdat Al-Bassam
Keyword(s):  
Fission Yeast ◽  
Functional Role ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Live Cell ◽  
Self Organization ◽  
Structural Studies ◽  
Overexpressed Gene

AbstractThe XMAP215/Stu2/Alp14 microtubule polymerases utilize Tumor Overexpressed Gene (TOG) domain arrays to accelerate microtubule plus-end polymerization. Structural studies suggest a microtubule polymerase model in which TOG arrays recruit four αβ-tubulins, forming large square assemblies; an array of TOG1 and TOG2 domains may then unfurl from the square state to polymerize two αβ-tubulins into protofilaments at microtubule ends. Here, we test this model using two biochemically characterized classes of fission yeast Alp14 mutants. Using in vitro reconstitution and in vivo live cell imaging, we show that αβ-tubulins recruited by TOG1 and TOG2 domains serve non-additive roles in microtubule plus-end tracking and polymerase activities. Alp14 mutants with inactivated square assembly interfaces have defects in processive plus-end tracking and poor microtubule polymerase, indicating a functional role for square assemblies in processive tracking. These studies provide functional insights into how TOG1 and TOG2 domain arrays recruit tubulins and promote polymerase at microtubule plus ends.

FRET based selective and ratiometric detection of Al(iii) with live-cell imaging

2017 ◽  
Vol 41 (23) ◽  
pp. 14266-14271 ◽  
Author(s):  
Abhishek Manna ◽  
Dibyendu Sain ◽  
Nikhil Guchhait ◽  
Shyamaprosad Goswami
Keyword(s):  
Live Cell Imaging ◽  
Cell Imaging ◽  
Live Cell ◽  
Dual Mode ◽  
Naked Eye ◽  
Ratiometric Detection ◽  
A Cell

A cell permeable FRET based platform for dual mode ‘naked-eye’in vitroandin vivodetection of Al3+over other common ions (including trivalent ions).

scholarly journals Visualizing the metazoan proliferation-quiescence decision in vivo

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Rebecca C Adikes ◽  
Abraham Q Kohrman ◽  
Michael A Q Martinez ◽  
Nicholas J Palmisano ◽  
Jayson J Smith ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Live Cell Imaging ◽  
Cell Imaging ◽  
Cell Cycle Control ◽  
Cell Lineage ◽  
Live Cell ◽  
C Elegans ◽  
Imaging Tool ◽  
Wide Range

Cell proliferation and quiescence are intimately coordinated during metazoan development. Here, we adapt a cyclin-dependent kinase (CDK) sensor to uncouple these key events of the cell cycle in C. elegans and zebrafish through live-cell imaging. The CDK sensor consists of a fluorescently tagged CDK substrate that steadily translocates from the nucleus to the cytoplasm in response to increasing CDK activity and consequent sensor phosphorylation. We show that the CDK sensor can distinguish cycling cells in G1 from quiescent cells in G0, revealing a possible commitment point and a cryptic stochasticity in an otherwise invariant C. elegans cell lineage. Finally, we derive a predictive model of future proliferation behavior in C. elegans based on a snapshot of CDK activity in newly born cells. Thus, we introduce a live-cell imaging tool to facilitate in vivo studies of cell cycle control in a wide-range of developmental contexts.

Sign in / Sign up

Export Citation Format

Share Document