A coral-on-a-chip microfluidic platform enabling live-imaging microscopy of reef-building corals

Abstract Coral reefs, and the unique ecosystems they support, are facing severe threats by human activities and climate change. Our understanding of these threats is hampered by the lack of robust approaches for studying the micro-scale interactions between corals and their environment. Here we present an experimental platform, coral-on-a-chip, combining micropropagation and microfluidics to allow direct microscopic study of live coral polyps. The small and transparent coral micropropagates are ideally suited for live-imaging microscopy, while the microfluidic platform facilitates long-term visualization under controlled environmental conditions. We demonstrate the usefulness of this approach by imaging coral micropropagates at previously unattainable spatio-temporal resolutions, providing new insights into several micro-scale processes including coral calcification, coral–pathogen interaction and the loss of algal symbionts (coral bleaching). Coral-on-a-chip thus provides a powerful method for studying coral physiology in vivo at the micro-scale, opening new vistas in coral biology.

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In vivo live imaging of postnatal neural stem cells

Development ◽

10.1242/dev.199778 ◽

2021 ◽

Vol 148 (18) ◽

Author(s):

Alina Marymonchyk ◽

Sarah Malvaut ◽

Armen Saghatelyan

Keyword(s):

Stem Cells ◽

Neural Stem Cells ◽

In Vivo Imaging ◽

Live Imaging ◽

Future Directions ◽

Environmental Signals ◽

New Information ◽

Imaging Results

ABSTRACT Neural stem cells (NSCs) are maintained in specific regions of the postnatal brain and contribute to its structural and functional plasticity. However, the long-term renewal potential of NSCs and their mode of division remain elusive. The use of advanced in vivo live imaging approaches may expand our knowledge of NSC physiology and provide new information for cell replacement therapies. In this Review, we discuss the in vivo imaging methods used to study NSC dynamics and recent live-imaging results with respect to specific intracellular pathways that allow NSCs to integrate and decode different micro-environmental signals. Lastly, we discuss future directions that may provide answers to unresolved questions regarding NSC physiology.

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Spatio-temporal heterogeneity and cell-specificity of long-term potentiation-induced mRNA expression in the dentate gyrus in vivo

Neuroscience ◽

10.1016/s0306-4522(01)00491-2 ◽

2002 ◽

Vol 110 (2) ◽

pp. 227-236 ◽

Cited By ~ 4

Author(s):

H Salin ◽

Y Maurin ◽

S Davis ◽

S Laroche ◽

J Mallet ◽

...

Keyword(s):

Dentate Gyrus ◽

Mrna Expression ◽

Long Term Potentiation ◽

Temporal Heterogeneity ◽

Cell Specificity ◽

Term Potentiation ◽

Spatio Temporal

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Spatio-temporal in vivo recording of dCREB2 dynamics in Drosophila long-term memory processing

Neurobiology of Learning and Memory ◽

10.1016/j.nlm.2014.11.010 ◽

2015 ◽

Vol 118 ◽

pp. 80-88 ◽

Cited By ~ 8

Author(s):

Jiabin Zhang ◽

Anne K. Tanenhaus ◽

John C. Davis ◽

Bret M. Hanlon ◽

Jerry C.P. Yin

Keyword(s):

Long Term Memory ◽

Term Memory ◽

Memory Processing ◽

Spatio Temporal

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Antimetastatic dsRNA mimics identified by live imaging of pathogenic neolymphangiogenesis

10.1101/2019.12.26.887943 ◽

2019 ◽

Cited By ~ 1

Author(s):

David Olmeda ◽

Daniela Cerezo-Wallis ◽

Tonantzin G. Calvo ◽

Direna Alonso ◽

Estela Cañón ◽

...

Keyword(s):

Tumor Progression ◽

Live Imaging ◽

Whole Body ◽

Whole Body Imaging ◽

Type I ◽

Double Stranded Rna ◽

Metastatic Relapse ◽

Lymphatic Vasculature ◽

Spatio Temporal

ABSTRACTThe crosstalk between cancer cells and the lymphatic vasculature has long been proposed to define competency for metastasis. Nevertheless, the discovery of selective blockers of lymphovascular niches has been compromised by the paucity of experimental systems for whole-body analyses of tumor progression. Here we present immunocompetent and immunodeficient mouse models for live imaging of melanoma-induced neolymphangiogenesis (driven by Vegfr3) as a cost-effective platform for drug screening in vivo. Spatio-temporal analyses in autochthonous melanomas and patient-derived xenografts identified double stranded RNA mimics (dsRNA nanoplexes) as potent repressors of lymphangiogenesis and metastasis. Mechanistically, dsRNA nanoplexes were found to suppress lymphangiogenic drivers in both tumor cells and their associated lymphatic vasculature (via MIDKINE and Vegfr3, respectively). This dual inhibitory action, driven by type I interferon, was not shared by FDA-approved antimelanoma treatments or by lymphangiogenic blockers in clinical testing. These results underscore the power of Vegfr3-lymphoreporters for pharmacological testing in otherwise aggressive cancers.RELEVANCEAlthough tumor-induced lymphangiogenesis has long been associated with metastasis, selective targeting of this process has been compromised by the paucity of experimental platforms for whole-body imaging of tumor progression and drug response. Here we present animal models engineered for spatio-temporal analyses of neolymphangiogenesis in clinically relevant autochthonous melanomas and patient-derived xenografts, and identify a unique action of double stranded-RNA nanoplexes as potent repressors of lymphatic dissemination and metastatic relapse.

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Long-term single-cell imaging and simulations of microtubules reveal principles behind wall patterning during proto-xylem development

Nature Communications ◽

10.1038/s41467-021-20894-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

René Schneider ◽

Kris van’t Klooster ◽

Kelsey L. Picard ◽

Jasper van der Gucht ◽

Taku Demura ◽

...

Keyword(s):

Cell Walls ◽

Live Cell Imaging ◽

Cell Imaging ◽

Live Cell ◽

Quantitative Microscopy ◽

Microtubule Severing ◽

Single Cell Imaging ◽

Spatio Temporal

AbstractPlants are the tallest organisms on Earth; a feature sustained by solute-transporting xylem vessels in the plant vasculature. The xylem vessels are supported by strong cell walls that are assembled in intricate patterns. Cortical microtubules direct wall deposition and need to rapidly re-organize during xylem cell development. Here, we establish long-term live-cell imaging of single Arabidopsis cells undergoing proto-xylem trans-differentiation, resulting in spiral wall patterns, to understand microtubule re-organization. We find that the re-organization requires local microtubule de-stabilization in band-interspersing gaps. Using microtubule simulations, we recapitulate the process in silico and predict that spatio-temporal control of microtubule nucleation is critical for pattern formation, which we confirm in vivo. By combining simulations and live-cell imaging we further explain how the xylem wall-deficient and microtubule-severing KATANIN contributes to microtubule and wall patterning. Hence, by combining quantitative microscopy and modelling we devise a framework to understand how microtubule re-organization supports wall patterning.

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Retinal Organoids Long-Term Functional Characterization Using Two-Photon Fluorescence Lifetime and Hyperspectral Microscopy

Frontiers in Cellular Neuroscience ◽

10.3389/fncel.2021.796903 ◽

2021 ◽

Vol 15 ◽

Author(s):

Yuntian Xue ◽

Andrew W. Browne ◽

William C. Tang ◽

Jeffrey Delgado ◽

Bryce T. McLelland ◽

...

Keyword(s):

Gene Expression ◽

Stem Cell ◽

Single Cell ◽

Fluorescence Lifetime ◽

Live Imaging ◽

Two Photon ◽

Nadh Ratio ◽

Gene Expression Levels

Pluripotent stem cell-derived organoid technologies have opened avenues to preclinical basic science research, drug discovery, and transplantation therapy in organ systems. Stem cell-derived organoids follow a time course similar to species-specific organ gestation in vivo. However, heterogeneous tissue yields, and subjective tissue selection reduce the repeatability of organoid-based scientific experiments and clinical studies. To improve the quality control of organoids, we introduced a live imaging technique based on two-photon microscopy to non-invasively monitor and characterize retinal organoids’ (RtOgs’) long-term development. Fluorescence lifetime imaging microscopy (FLIM) was used to monitor the metabolic trajectory, and hyperspectral imaging was applied to characterize structural and molecular changes. We further validated the live imaging experimental results with endpoint biological tests, including quantitative polymerase chain reaction (qPCR), single-cell RNA sequencing, and immunohistochemistry. With FLIM results, we analyzed the free/bound nicotinamide adenine dinucleotide (f/b NADH) ratio of the imaged regions and found that there was a metabolic shift from glycolysis to oxidative phosphorylation. This shift occurred between the second and third months of differentiation. The total metabolic activity shifted slightly back toward glycolysis between the third and fourth months and stayed relatively stable between the fourth and sixth months. Consistency in organoid development among cell lines and production lots was examined. Molecular analysis showed that retinal progenitor genes were expressed in all groups between days 51 and 159. Photoreceptor gene expression emerged around the second month of differentiation, which corresponded to the shift in the f/b NADH ratio. RtOgs between 3 and 6 months of differentiation exhibited photoreceptor gene expression levels that were between the native human fetal and adult retina gene expression levels. The occurrence of cone opsin expression (OPN1 SW and OPN1 LW) indicated the maturation of photoreceptors in the fourth month of differentiation, which was consistent with the stabilized level of f/b NADH ratio starting from 4 months. Endpoint single-cell RNA and immunohistology data showed that the cellular compositions and lamination of RtOgs at different developmental stages followed those in vivo.

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