scholarly journals Single cell resolution in vivo imaging of DNA damage following PARP inhibition

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Katherine S. Yang ◽  
Rainer H. Kohler ◽  
Matthieu Landon ◽  
Randy Giedt ◽  
Ralph Weissleder
Keyword(s):  
Dna Damage ◽  
Single Cell ◽  
In Vivo Imaging ◽  
Parp Inhibition

From In Vitro to In Vivo: Imaging from the Single Cell to the Whole Organism

2008 ◽  
Vol 44 (1) ◽  
Author(s):  
Jung Julie Kang ◽  
Ildiko Toma ◽  
Arnold Sipos ◽  
Janos Peti‐Peterdi
Keyword(s):  
Single Cell ◽  
In Vivo Imaging

scholarly journals Myelin replacement triggered by single-cell demyelination in mouse cortex

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nicolas Snaidero ◽  
Martina Schifferer ◽  
Aleksandra Mezydlo ◽  
Bernard Zalc ◽  
Martin Kerschensteiner ◽  
...  
Keyword(s):  
Laser Ablation ◽  
Single Cell ◽  
In Vivo Imaging ◽  
Active Participant ◽  
Cell Replacement ◽  
Myelin Sheaths ◽  
Unmyelinated Axons ◽  
Single Axon ◽  
Mouse Cortex

Abstract Myelin, rather than being a static insulator of axons, is emerging as an active participant in circuit plasticity. This requires precise regulation of oligodendrocyte numbers and myelination patterns. Here, by devising a laser ablation approach of single oligodendrocytes, followed by in vivo imaging and correlated ultrastructural reconstructions, we report that in mouse cortex demyelination as subtle as the loss of a single oligodendrocyte can trigger robust cell replacement and remyelination timed by myelin breakdown. This results in reliable reestablishment of the original myelin pattern along continuously myelinated axons, while in parallel, patchy isolated internodes emerge on previously unmyelinated axons. Therefore, in mammalian cortex, internodes along partially myelinated cortical axons are typically not reestablished, suggesting that the cues that guide patchy myelination are not preserved through cycles of de- and remyelination. In contrast, myelin sheaths forming continuous patterns show remarkable homeostatic resilience and remyelinate with single axon precision.

Abstract 4293: In vivo imaging and tracking of a PARP inhibitor at single-cell resolution

2012 ◽  
Author(s):  
Katherine Yang ◽  
Greg Thurber ◽  
Thomas Reiner ◽  
Rainer Kohler ◽  
Ralph Weissleder
Keyword(s):  
Single Cell ◽  
In Vivo Imaging ◽  
Parp Inhibitor

scholarly journals Convergent molecular, cellular, and cortical neuroimaging signatures of major depressive disorder

2020 ◽  
Vol 117 (40) ◽  
pp. 25138-25149
Author(s):  
Kevin M. Anderson ◽  
Meghan A. Collins ◽  
Ru Kong ◽  
Kacey Fang ◽  
Jingwei Li ◽  
...  
Keyword(s):  
Major Depressive Disorder ◽  
Negative Affect ◽  
Depressive Disorder ◽  
Single Cell ◽  
In Vivo Imaging ◽  
Ex Vivo ◽  
Integrated Analysis ◽  
Down Regulation ◽  
Major Depressive

Major depressive disorder emerges from the complex interactions of biological systems that span genes and molecules through cells, networks, and behavior. Establishing how neurobiological processes coalesce to contribute to depression requires a multiscale approach, encompassing measures of brain structure and function as well as genetic and cell-specific transcriptional data. Here, we examine anatomical (cortical thickness) and functional (functional variability, global brain connectivity) correlates of depression and negative affect across three population-imaging datasets: UK Biobank, Brain Genomics Superstruct Project, and Enhancing NeuroImaging through Meta Analysis (ENIGMA; combined n ≥ 23,723). Integrative analyses incorporate measures of cortical gene expression, postmortem patient transcriptional data, depression genome-wide association study (GWAS), and single-cell gene transcription. Neuroimaging correlates of depression and negative affect were consistent across three independent datasets. Linking ex vivo gene down-regulation with in vivo neuroimaging, we find that transcriptional correlates of depression imaging phenotypes track gene down-regulation in postmortem cortical samples of patients with depression. Integrated analysis of single-cell and Allen Human Brain Atlas expression data reveal somatostatin interneurons and astrocytes to be consistent cell associates of depression, through both in vivo imaging and ex vivo cortical gene dysregulation. Providing converging evidence for these observations, GWAS-derived polygenic risk for depression was enriched for genes expressed in interneurons, but not glia. Underscoring the translational potential of multiscale approaches, the transcriptional correlates of depression-linked brain function and structure were enriched for disorder-relevant molecular pathways. These findings bridge levels to connect specific genes, cell classes, and biological pathways to in vivo imaging correlates of depression.

scholarly journals Single-cell in vivo imaging of adult neural stem cells in the zebrafish telencephalon

2016 ◽  
Vol 11 (8) ◽  
pp. 1360-1370 ◽  
Author(s):  
Joana S Barbosa ◽  
Rossella Di Giaimo ◽  
Magdalena Götz ◽  
Jovica Ninkovic
Keyword(s):  
Stem Cells ◽  
Neural Stem Cells ◽  
Single Cell ◽  
In Vivo Imaging ◽  
Adult Neural Stem Cells

scholarly journals In Vivo Imaging of Drug-Induced Mitochondrial Outer Membrane Permeabilization at Single-Cell Resolution

2012 ◽  
Vol 72 (12) ◽  
pp. 2949-2956 ◽  
Author(s):  
Sarah Earley ◽  
Claudio Vinegoni ◽  
Joshua Dunham ◽  
Rostic Gorbatov ◽  
Paolo Fumene Feruglio ◽  
...  
Keyword(s):  
Single Cell ◽  
Outer Membrane ◽  
In Vivo Imaging ◽  
Membrane Permeabilization ◽  
Mitochondrial Outer Membrane ◽  
Drug Induced ◽  
Mitochondrial Outer Membrane Permeabilization

scholarly journals Targeting an RNaseH2 Defect in Chronic Lymphocytic Leukaemia with PARP Inhibitors

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1835-1835
Author(s):  
Angelo Agathaggelou ◽  
Olga Murina ◽  
Andrew P Jackson ◽  
Paul Moss ◽  
Shankara Paneesha ◽  
...  
Keyword(s):  
Dna Damage ◽  
Enzymatic Activity ◽  
Parp Inhibitors ◽  
Tumour Cells ◽  
Parp Inhibition ◽  
Tumour Suppressor Genes ◽  
Molecular Defects ◽  
Enzymatic Complex ◽  
Enzymatic Defect

Abstract The therapeutic exploitation of molecular defects within the DNA damage response (DDR) in tumour cells has become an important treatment paradigm. 'Synthetic lethality' relies on pharmacological inhibition of pathways upon which DDR-deficient tumour cells have become dependent for their survival. This induces an intolerable level of unrepaired DNA damage in the tumour cells resulting in cell death, whilst sparing DDR-proficient normal cells Deletion of 13q14 is a frequent, early event in the pathogenesis of CLL. Alongside well-described tumour suppressor genes this genomic region also encompasses the DDR gene, RNASEH2B, which encodes a subunit of the heterotrimeric enzymatic complex, RNaseH2. This complex is a principal component of ribonucleotide excision repair (RER), a DDR pathway that removes ribonucleotides incorporated into DNA by error prone DNA repair polymerases. If unremoved, these DNA-incorporated ribonucleotides lead to DNA damage, chromosome instability and mutagenesis (Reijns et al, Cell. 2012;149:1008). We recently reported a synthetically lethal interaction between the functional loss of RNaseH2 enzymatic complex and PARP inhibition (Zimmerman et al, Nature 2018, 559:285). We observed that inactivation of any of the three RNAseH2 subunits (A,B,C) leads to loss of enzymatic activity of this complex and also that primary CLL tumours with 13q14 deletion involving the RNASEH2B locus are sensitive to PARP inhibitors (PARPi) in vitro. In light of these preliminary observations, we addressed the following questions: a) Do monoalleic and biallelic RNASEH2B deletions have equal consequences for RNAseH2 enzymatic activity and sensitivity to PARP inhibition in CLL? d) Can loss of RNAseH2 activity be caused by an alternative mechanism, such as mutations in RNASEH2B? c) Can the PARPi sensitivity of RNaseH2-deficient CLLs be demonstrated in vivo, in patient-derived xenografts? d) Is PARP inhibition an option for RNAseH2 deficient tumours with limited response to other treatments? Analysis of 100 primary CLL tumours through a combination of multiplex ligation-dependent probe amplification (MLPA), CGH microarrays and Sanger sequencing identified 29 tumours with monoallelic and 14 with biallelic RNASEH2B deletions. None of the analysed tumours had mutations in RNASEH2B. Increased levels of genomic ribonucleotides were confirmed in all RNASEH2B deleted tumours by two complementary methods: alkaline gel electrophoresis and DNA nick translation. We found that the RNaseH2 enzymatic defect and sensitivity to PARP inhibition were evident in all RNASEH2B deleted tumours, but were more profound in those harbouring biallelic deletion compared to tumours that have lost only one RNASEH2B allele. Furthermore, sensitivity to PARP inhibitors was dependent on PARP-trapping capacity and therefore cytotoxicity was most prominent in response to PARP-inhibitors with a potent PARP trapping capacity such as talazoparib. In vivo experiments revealed similar trends, with CLL xenografts derived from tumours with biallelic RNASEH2B deletion being differentially sensitive to Talazoparib. Notably, the PARP inhibition sensitivity of RNAseH2-deficient primary CLLs was independent of patients' response to different treatments. In summary, we conclude that the RNASEH2B loss associated with 13q14 deletion represents a frequent cause of RNaseH2 enzymatic defect that renders primary CLL tumours sensitive to PARP-trapping inhibitors. Our findings expand the range of molecular defects in CLL that are amenable to treatment with clinically applicable PARP inhibitors and may have implications for the management of patients with limited response to other treatments. Disclosures No relevant conflicts of interest to declare.

scholarly journals Correction: Single-cell in vivo imaging of cellular circadian oscillators in zebrafish

PLoS Biology ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. e3001382
Author(s):  
Haifang Wang ◽  
Zeyong Yang ◽  
Xingxing Li ◽  
Dengfeng Huang ◽  
Shuguang Yu ◽  
...  
Keyword(s):  
Single Cell ◽  
In Vivo Imaging ◽  
Circadian Oscillators

scholarly journals In Vivo Mechanisms of Chemotherapy-Induced Acute Follicle Loss in the Human Ovary: An Individual-Oocyte Transcriptomic Analysis from Human Ovarian Xenografts

2020 ◽  
Author(s):  
S. Titus ◽  
K.J. Szymanska ◽  
B. Musul ◽  
V. Turan ◽  
E. Taylan ◽  
...  
Keyword(s):  
Dna Damage ◽  
Single Cell ◽  
Rna Sequencing ◽  
Ovarian Reserve ◽  
Xenograft Model ◽  
Primordial Follicle ◽  
Human Ovary ◽  
Primordial Follicles ◽  
Growth Initiation

AbstractGonadotoxic chemotherapeutics, such as cyclophosphamide, cause early menopause and infertility in women. Earlier histological studies showed ovarian reserve depletion via severe DNA damage and apoptosis, but others suggested activation of PI3K/PTEN/Akt pathway and follicle ‘burn-out’ as a cause. Using a human ovarian xenograft model, we performed single-cell RNA-sequencing on laser-captured individual primordial follicle oocytes 12h after a single cyclophosphamide injection to determine the mechanisms of acute follicle loss after gonadotoxic chemotherapy. RNA-sequencing showed 190 differentially expressed genes between the cyclophosphamide- and vehicle-exposed oocytes. Ingenuity Pathway Analysis predicted a significant decrease in the expression of anti-apoptotic pro-Akt PECAM1 (p=2.13E-09), IKBKE (p=0.0001), and ANGPT1 (p=0.003), and reduced activation of PI3K/PTEN/Akt after cyclophosphamide. The qRT-PCR and immunostaining confirmed that in primordial follicle oocytes, cyclophosphamide did not change the expressions of Akt (p=0.9), rpS6 (p=0.3), Foxo3a (p=0.12) and anti-apoptotic Bcl2 (p=0.17), nor affect their phosphorylation status. There was significantly increased DNA damage by γH2AX (p=0.0002) and apoptosis by active-caspase-3 (p=0.0001) staining in the primordial follicles and no change in the growing follicles 12h after chemotherapy. These data suggest that the mechanism of acute follicle loss by cyclophosphamide is via apoptosis, rather than growth activation of primordial follicle oocytes in the human ovary.One Sentence SummarySingle-cell transcriptomic interrogation of primordial follicles in human ovarian xenografts reveals that chemotherapy causes acute ovarian reserve depletion by inducing a pro-apoptotic state rather than activating pathways that result in follicle growth initiation.

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