scholarly journals CLARITY and Light-Sheet microscopy sample preparation in application to human cerebral organoids

2022 ◽  
Vol 25 (8) ◽  
pp. 889-895
Author(s):  
T. A. Shnaider ◽  
I. E. Pristyazhnyuk

Cerebral organoids are three-dimensional cell-culture systems that represent a unique experimental model reconstructing early events of human neurogenesis in vitro in health and various pathologies. The most commonly used approach to studying the morphological parameters of organoids is immunohistochemical analysis; therefore, the three-dimensional cytoarchitecture of organoids, such as neural networks or asymmetric internal organization, is difficult to reconstruct using routine approaches. Immunohistochemical analysis of biological objects is a universal method in biological research. One of the key stages of this method is the production of cryo- or paraffin serial sections of samples, which is a very laborious and time-consuming process. In addition, slices represent only a tiny part of the object under study; three-dimensional reconstruction from the obtained serial images is an extremely complex process and often requires expensive special programs for image processing. Unfortunately, staining and microscopic examination of samples are difficult due to their low permeability and a high level of autofluorescence. Tissue cleaning technologies combined with Light-Sheet microscopy allows these challenges to be overcome. CLARITY is one of the tissue preparation techniques that makes it possible to obtain opaque biological objects transparent while maintaining the integrity of their internal structures. This method is based on a special sample preparation, during which lipids are removed from cells and replaced with hydrogel compounds such as acrylamide, while proteins and nucleic acids remain intact. CLARITY provides researchers with a unique opportunity to study three-dimensional biological structures while preserving their internal organization, including whole animals or embryos, individual organs and artificially grown organoids, in particular cerebral organoids. This protocol summarizes an optimization of CLARITY conditions for human brain organoids and the preparation of Light-Sheet microscopy samples.

Author(s):  
Yuta Otsuka ◽  
Hirokazu Tsukaya

AbstractOrganisms have a variety of three-dimensional (3D) structures that change over time. These changes include twisting, which is 3D deformation that cannot happen in two dimensions. Twisting is linked to important adaptive functions of organs, such as adjusting the orientation of leaves and flowers in plants to align with environmental stimuli (e.g. light, gravity). Despite its importance, the underlying mechanism for twisting remains to be determined, partly because there is no rigorous method for quantifying the twisting of plant organs. Conventional studies have relied on approximate measurements of the twisting angle in 2D, with arbitrary choices of observation angle. Here, we present the first rigorous quantification of the 3D twisting angles of Arabidopsis petioles based on light sheet microscopy. Mathematical separation of bending and twisting with strict definition of petiole cross-sections were implemented; differences in the spatial distribution of bending and twisting were detected via the quantification of angles along the petiole. Based on the measured values, we discuss that minute degrees of differential growth can result in pronounced twisting in petioles.


2017 ◽  
Vol 153 (4) ◽  
pp. 898-900 ◽  
Author(s):  
Sebastian Zundler ◽  
Anika Klingberg ◽  
Daniela Schillinger ◽  
Sarah Fischer ◽  
Clemens Neufert ◽  
...  

PLoS ONE ◽  
2014 ◽  
Vol 9 (6) ◽  
pp. e96551 ◽  
Author(s):  
Kavya Mohan ◽  
Subhajit B. Purnapatra ◽  
Partha Pratim Mondal

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Lillian K Fritz-Laylin ◽  
Megan Riel-Mehan ◽  
Bi-Chang Chen ◽  
Samuel J Lord ◽  
Thomas D Goddard ◽  
...  

Leukocytes and other amoeboid cells change shape as they move, forming highly dynamic, actin-filled pseudopods. Although we understand much about the architecture and dynamics of thin lamellipodia made by slow-moving cells on flat surfaces, conventional light microscopy lacks the spatial and temporal resolution required to track complex pseudopods of cells moving in three dimensions. We therefore employed lattice light sheet microscopy to perform three-dimensional, time-lapse imaging of neutrophil-like HL-60 cells crawling through collagen matrices. To analyze three-dimensional pseudopods we: (i) developed fluorescent probe combinations that distinguish cortical actin from dynamic, pseudopod-forming actin networks, and (ii) adapted molecular visualization tools from structural biology to render and analyze complex cell surfaces. Surprisingly, three-dimensional pseudopods turn out to be composed of thin (<0.75 µm), flat sheets that sometimes interleave to form rosettes. Their laminar nature is not templated by an external surface, but likely reflects a linear arrangement of regulatory molecules. Although we find that Arp2/3-dependent pseudopods are dispensable for three-dimensional locomotion, their elimination dramatically decreases the frequency of cell turning, and pseudopod dynamics increase when cells change direction, highlighting the important role pseudopods play in pathfinding.


Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1255
Author(s):  
Norio Yamashita ◽  
Masahiko Morita ◽  
Hideo Yokota ◽  
Yuko Mimori-Kiyosue

From cells to organisms, every living system is three-dimensional (3D), but the performance of fluorescence microscopy has been largely limited when attempting to obtain an overview of systems’ dynamic processes in three dimensions. Recently, advanced light-sheet illumination technologies, allowing drastic improvement in spatial discrimination, volumetric imaging times, and phototoxicity/photobleaching, have been making live imaging to collect precise and reliable 3D information increasingly feasible. In particular, lattice light-sheet microscopy (LLSM), using an ultrathin light-sheet, enables whole-cell 3D live imaging of cellular processes, including mitosis, at unprecedented spatiotemporal resolution for extended periods of time. This technology produces immense and complex data, including a significant amount of information, raising new challenges for big image data analysis and new possibilities for data utilization. Once the data are digitally archived in a computer, the data can be reused for various purposes by anyone at any time. Such an information science approach has the potential to revolutionize the use of bioimage data, and provides an alternative method for cell biology research in a data-driven manner. In this article, we introduce examples of analyzing digital mitotic spindles and discuss future perspectives in cell biology.


2020 ◽  
Author(s):  
Niall Hanrahan ◽  
Simon I. R. Lane ◽  
Peter Johnson ◽  
Konstantinos Bourdakos ◽  
Christopher Brereton ◽  
...  

AbstractLight sheet microscopy (LSM) has emerged as one of most profound three dimensional (3D) imaging tools in the life sciences over the last decade. However, LSM is currently performed with fluorescence detection on one- or multi-photon excitation. Label-free LSM imaging approaches have been rather limited. Second Harmonic Generation (SHG) imaging is a label-free technique that has enabled detailed investigation of collagenous structures, including its distribution and remodelling in cancers and respiratory tissue, and how these link to disease. SHG is generally regarded as having only forward- and back-scattering components, apparently precluding the orthogonal detection geometry used in Light Sheet Microscopy. In this work we demonstrate SHG imaging on a light sheet microscope (SHG-LSM) using a rotated Airy beam configuration that demonstrates a powerful new approach to direct, without any further processing or deconvolution, 3D imaging of harmonophores such as collagen in biological samples. We provide unambiguous identification of SHG signals on the LSM through its wavelength and polarisation sensitivity. In a multimodal LSM setup we demonstrate that SHG and two-photon signals can be acquired on multiple types of different biological samples. We further show that SHG-LSM is sensitive to changes in collagen synthesis within lung fibroblast 3D cell cultures. This work expands on the existing optical methods available for use with light sheet microscopy, adding a further label-free imaging technique which can be combined with other detection modalities to realise a powerful multi-modal microscope for 3D bioimaging.


2021 ◽  
Author(s):  
Harold F. Gómez ◽  
Mathilde S. Dumont ◽  
Leonie Hodel ◽  
Roman Vetter ◽  
Dagmar Iber

ABSTRACTDuring morphogenesis, epithelial sheets remodel into complex geometries. How cells dynamically organize their contact with neighbouring cells in these tightly packed tissues is poorly understood. We have used light-sheet microscopy of growing mouse embryonic lung explants, three-dimensional cell segmentation, and physical theory to unravel the principles behind 3D cell organization in growing pseudostratified epithelia. We find that cells have highly irregular 3D shapes and exhibit numerous neighbour intercalations along the apical-basal axis as well as over time. Despite the fluidic nature, the cell packing configurations follow fundamental relationships previously described for apical epithelial layers, i.e., Euler’s formula, Lewis’ law, and Aboav-Weaire’s law, at all times and across the entire tissue thickness. This arrangement minimizes the lateral cell-cell surface energy for a given cross-sectional area variability, generated primarily by the distribution and movement of nuclei. We conclude that the complex 3D cell organization in growing epithelia emerges from simple physical principles.


Sign in / Sign up

Export Citation Format

Share Document